High efficiency cabin air filter in vehicles reduces drivers' roadway particulate matter exposures and associated lipid peroxidation.

PubMed

Yu, Nu; Shu, Shi; Lin, Yan; She, Jianwen; Ip, Ho Sai Simon; Qiu, Xinghua; Zhu, Yifang

2017-01-01

Commuters who spend long hours on roads are exposed to high levels of traffic related air pollutants (TRAPs). Despite some well-known multiple adverse effects of TRAPs on human health, limited studies have focused on mitigation strategies to reduce these effects. In this study, we measured fine particulate matter (PM2.5) and ultrafine particle (UFP) concentrations inside and outside 17 taxis simultaneously while they were driven on roadways. The drivers' urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and malondialdehyde (MDA) concentrations just before and right after the driving tests were also determined. Data were collected under three driving conditions (i.e. no mitigation (NM), window closed (WC), and window closed plus using high efficiency cabin air filters (WC+HECA)) for each taxi and driver. The results show that, compared to NM, the WC+HECA reduced in-cabin PM2.5 and UFP concentrations, by 37% and 47% respectively (p < 0.05), whereas the reductions on PAH exposures were insignificant. Although nonsignificant, a reduction of 17% was also observed in the drivers' urinary MDA under WC+HECA. The MDA concentrations were found to be significantly associated with the in-cabin PM2.5 and UFP concentrations, suggesting the reduction of the drivers' lipid peroxidation can be at least partially attributed to the PM2.5 and UFP reduction by WC+HECA. Overall, these results suggest HECA filters have potential to reduce particle levels inside taxis and protect drivers' health.

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air.

PubMed

Jung, Heejung S; Grady, Michael L; Victoroff, Tristan; Miller, Arthur L

2017-07-01

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO 2 ) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO 2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm 3 , although CO 2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO 2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm 3 . We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO 2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO 2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO 2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO 2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO 2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO 2 accumulation.

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

PubMed Central

Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

2017-01-01

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50–75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants’ exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation. PMID:28781568

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

NASA Astrophysics Data System (ADS)

Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

2017-07-01

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

Development of a new photocatalytic oxidation air filter for aircraft cabin.

PubMed

Ginestet, A; Pugnet, D; Rowley, J; Bull, K; Yeomans, H

2005-10-01

A new photocatalytic oxidation air filter (PCO unit) has been designed for aircraft cabin applications. The PCO unit is designed as a regenerable VOC removal system in order to improve the quality of the recirculated air entering the aircraft cabin. The PCO was designed to be a modular unit, with four UV lamps sandwiched between two interchangeable titanium dioxide coated panels. Performances of the PCO unit has been measured in a single pass mode test rig in order to show the ability of the unit to decrease the amount of VOCs (toluene, ethanol, and acetone) entering it (VOCs are fed separately), and in a multipass mode test rig in order to measure the ability of the unit to clean the air of an experimental room polluted with the same VOCs (fed separately). Triangular cell panels have been chosen instead of the wire mesh panels because they have higher efficiency. The efficiency of the PCO unit depends on the type of VOCs that challenges it, toluene being the most difficult one to oxidise. The efficiency of the PCO unit decreases when the air flow rate increases. The multipass mode test results show that the VOCs are oxidized but additional testing time would be necessary in order to show if they can be fully oxidized. The intermediate reaction products are mainly acetaldehyde and formaldehyde whose amount depends on the challenge VOC. The intermediate reaction products are also oxidized and additional testing time would be necessary in order to show if they can be fully oxidized. The development of this new photocatalytic air filter is still going on. The VOC/odor removing adsorbers are available for only a small proportion of aircraft currently in service. The photocatalytic oxidation (PCO) technique has appeared to be a promising solution to odors problems met in aircraft. This article reports the test results of a new photocatalytic oxidation air filter (PCO unit) designed for aircraft cabin applications. The overall efficiency of the PCO unit is function of the compound (toluene, ethanol, and acetone) that challenges the unit and toluene appears to be the most difficult compound to oxidize. Test results have shown the influence of the design of the PCO unit, the air flow rate and the type of UV on the efficiency of the PCO unit. The results obtained in this study represent a first attempt on the way to design a filter for VOC removal in cabin aircraft applications. The PCO technique used by the tested prototype unit is able to partially oxidized the challenge VOCs but one has to be aware that some harmful intermediate reaction products (mainly formaldehyde and acetaldehyde) are produced during the oxidation process before being partially oxidized too.

Aircraft cabin ozone measurements on B747-100 and B747-SP aircraft: Correlations with atmospheric ozone and ozone encounter statistics

NASA Technical Reports Server (NTRS)

Perkins, P. J.; Holdeman, J. D.; Gauntner, D. J.

1978-01-01

Simultaneous measurements of atmospheric (outside) ozone concentration and ozone levels in the cabin of the B747-100 and B747-SP airliners were made by NASA to evaluate the aircraft cabin ozone contamination problem. Instrumentation on these aircraft measured ozone from an outside probe and at one point in the cabin. Average ozone in the cabin of the B747-100 was 39 percent of the outside. Ozone in the cabin of the B747-SP measured 82 percent of the outside, before corrective measures. Procedures to reduce the ozone in this aircraft included changes in the cabin air circulation system, use of the high-temperature 15th stage compressor bleed, and charcoal filters in the inlet cabin air ducting, which as separate actions reduced the ozone to 58, 19 and 5 percent, respectively. The potential for the NASA instrumented B747 aircraft to encounter high levels of cabin ozone was derived from atmospheric oxone measurements on these aircraft. Encounter frequencies for two B747-100's were comparable even though the route structures were different. The B747-SP encountered high ozone than did the B747-100's.

STS-40 DTO 647 prototype filter documented under OV-102's middeck subfloor

NASA Technical Reports Server (NTRS)

1991-01-01

STS-40 Detailed Test Objective (DTO) 647, Water Separator Filter Performance Evaluation, prototype filter installed at the inlet of the water separator is documented under middeck subfloor aboard Columbia, Orbiter Vehicle (OV) 102. The proposed filter is being tested for its ability to remove debris from the air/water stream coming from the cabin heat exchanger.

Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.; Frederick, Kenneth R.; Mccormick, Robert M.

2017-01-01

Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed.

Microbiological analysis of debris from Space Transportation System (STS)-55 Spacelab D-2

NASA Technical Reports Server (NTRS)

Huff, T. L.

1994-01-01

Filter debris from the Spacelab module D-2 of STS-55 was analyzed for microbial contamination. Debris from cabin and avionics filters was collected by Kennedy Space Center personnel on May 8, 1993, 2 days postflight. Debris weights were similar to those of previous Spacelab missions. Approximately 5.1E+5 colony forming units per gram of debris were enumerated from the cabin and avionics filter debris, respectively. these numbers were similar in previous missions for which the entire contents were analyzed without sorting of the material. Bacterial diversity was small compared to previous missions, with no gram negative bacteria isolated. Only one bacterial species, Corynebacterium pseudodiphtheriticum, was not isolated previously by the laboratory from Spacelab debris. This organism is a normal inhabitant of the pharynx. A table listing all species of bacteria isolated by the laboratory from previous Spacelab air filters debris collection is provided.

Analyses of integrated aircraft cabin contaminant monitoring network based on Kalman consensus filter.

PubMed

Wang, Rui; Li, Yanxiao; Sun, Hui; Chen, Zengqiang

2017-11-01

The modern civil aircrafts use air ventilation pressurized cabins subject to the limited space. In order to monitor multiple contaminants and overcome the hypersensitivity of the single sensor, the paper constructs an output correction integrated sensor configuration using sensors with different measurement theories after comparing to other two different configurations. This proposed configuration works as a node in the contaminant distributed wireless sensor monitoring network. The corresponding measurement error models of integrated sensors are also proposed by using the Kalman consensus filter to estimate states and conduct data fusion in order to regulate the single sensor measurement results. The paper develops the sufficient proof of the Kalman consensus filter stability when considering the system and the observation noises and compares the mean estimation and the mean consensus errors between Kalman consensus filter and local Kalman filter. The numerical example analyses show the effectiveness of the algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Products of ozone-initiated chemistry in a simulated aircraft environment.

PubMed

Wisthaler, Armin; Tamás, Gyöngyi; Wyon, David P; Strøm-Tejsen, Peter; Space, David; Beauchamp, Jonathan; Hansel, Armin; Märk, Tilmann D; Weschler, Charles J

2005-07-01

We used proton-transfer-reaction mass spectrometry (PTR-MS) to examine the products formed when ozone reacted with the materials in a simulated aircraft cabin, including a loaded high-efficiency particulate air (HEPA) filter in the return air system. Four conditions were examined: cabin (baseline), cabin plus ozone, cabin plus soiled T-shirts (surrogates for human occupants), and cabin plus soiled T-shirts plus ozone. The addition of ozone to the cabin without T-shirts, at concentrations typically encountered during commercial air travel, increased the mixing ratio (v:v concentration) of detected pollutants from 35 ppb to 80 ppb. Most of this increase was due to the production of saturated and unsaturated aldehydes and tentatively identified low-molecular-weight carboxylic acids. The addition of soiled T-shirts, with no ozone present, increased the mixing ratio of pollutants in the cabin air only slightly, whereas the combination of soiled T-shirts and ozone increased the mixing ratio of detected pollutants to 110 ppb, with more than 20 ppb originating from squalene oxidation products (acetone, 4-oxopentanal, and 6-methyl-5-hepten-2-one). For the two conditions with ozone present, the more-abundant oxidation products included acetone/propanal (8-20 ppb), formaldehyde (8-10 ppb), nonanal (approximately 6 ppb), 4-oxopentanal (3-7 ppb), acetic acid (approximately 7 ppb), formic acid (approximately 3 ppb), and 6-methyl-5-hepten-2-one (0.5-2.5 ppb), as well as compounds tentatively identified as acrolein (0.6-1 ppb) and crotonaldehyde (0.6-0.8 ppb). The odor thresholds of certain products were exceeded. With an outdoor air exchange of 3 h(-1) and a recirculation rate of 20 h(-1), the measured ozone surface removal rate constant was 6.3 h(-1) when T-shirts were not present, compared to 11.4 h(-1) when T-shirts were present.

Characterizing ultrafine particles and other air pollutants in and around school buses.

PubMed

Zhu, Yifang; Zhang, Qunfang

2014-03-01

Increasing evidence has demonstrated toxic effects of ultrafine particles (UFP*, diameter < 100 nm). Children are particularly at risk because of their immature respiratory systems and higher breathing rates per body mass. This study aimed to characterize UFP, PM2.5 (particulate matter < or = 2.5 microm in aerodynamic diameter), and other vehicular-emitted pollutants in and around school buses. Four sub-studies were conducted, including: 1. On-road tests to measure in-cabin air pollutant levels while school buses were being driven; 2. Idling tests to determine the contributions of tailpipe emissions from idling school buses to air pollutant levels in and around school buses under different scenarios; 3. Retrofit tests to evaluate the performance of two retrofit systems, a diesel oxidation catalyst (DOC) muffler and a crankcase filtration system (CFS), on reducing tailpipe emissions and in-cabin air pollutant concentrations under idling and driving conditions; and 4. High efficiency particulate air (HEPA) filter air purifier tests to evaluate the effectiveness of in-cabin filtration. In total, 24 school buses were employed to cover a wide range of school buses commonly used in the United States. Real-time air quality measurements included particle number concentration (PNC), fine and UFP size distribution in the size range 7.6-289 nm, PM2.5 mass concentration, black carbon (BC) concentration, and carbon monoxide (CO) and carbon dioxide (CO2) concentrations. For in-cabin measurements, instruments were placed on a platform secured to the rear seats inside the school buses. For all other tests, a second set of instruments was deployed to simultaneously measure the ambient air pollutant levels. For tailpipe emission measurements, the exhaust was diluted and then measured by instruments identical to those used for the in-cabin measurements. The results show that when driving on roads, in-cabin PNC, fine and UFP size distribution, PM2.5, BC, and CO varied by engine age, window position, driving speed, driving route, and operating conditions. Emissions from idling school buses increased the PNC close to the tailpipe by a factor of up to 26.0. Under some circumstances, tailpipe emissions of idling school buses increased the in-cabin PNC by factors ranging from 1.2 to 5.8 in the 10-30 nm particle size range. Retrofit systems significantly reduced the tailpipe emissions of idling school buses. With both DOC and CFS installed, PNC in tailpipe emissions dropped by 20%-94%. No unequivocal decrease was observed for in-cabin air pollutants after retrofitting. The operation of the air conditioning (AC) unit and the pollutant concentrations in the surrounding ambient air played more important roles than retrofit technologies in determining in-cabin air quality. The use of a HEPA air purifier removed up to 50% of in-cabin particles. Because each sub-study tested only a subset of the 24 school buses, the results should be seen as more exploratory than definitive.

Airliner cabin ozone : an updated review.

DOT National Transportation Integrated Search

1989-12-01

The recent literature pertaining to ozone contamination of airliner cabins is reviewed. Measurements in airliner cabins without filters showed that ozone levels were about 50 percent of atmospheric ozone. Filters were about 90 percent effective in de...

Comparison of the constituents of two jet engine lubricating oils and their volatile pyrolytic degradation products.

PubMed

van Netten, C; Leung, V

2000-03-01

Leaking oil seals in jet engines, at locations prior to the compressor stage, can be a cause of smoke in the cabins of BAe-146 aircraft. Compressed combustion air is bled off to pressurize the cabin and to provide a source of fresh air. Bleed air is diverted from a location just prior to the combustion chamber at a temperature around 500 degrees C. To prevent oil breakdown products from entering the cabin air, catalytic converters have been used to clean the air. During an oil seal failure this device becomes overloaded and smoke is observed in the cabin. Some aircraft companies have removed the catalytic converters and claim an improvement in air quality. During an oil seal failure, however, the flight crew is potentially exposed to the thermal breakdown products of the engine oils. Because very little is known regarding the thermal breakdown products of jet engine lubrication oils, two commercially available oils were investigated under laboratory conditions at 525 degrees C to measure the release of CO, CO2,NO2, and HCN as well as volatiles which were analyzed using GC-Mass spectrometry in an attempt to see if the neurotoxic agents tricresyl phosphates (TCPs) and trimethyl propane phosphate (TMPP) would be present or formed. TMPP was not found in these experiments. Some CO2 was generated along with CO which reached levels in excess of 100 ppm. HCN and NO2 were not detected. GC compositions of the two bulk oils and their breakdown products were almost identical. The presence of TCPs was confirmed in the bulk oils and in the volatiles. Localized condensation in the ventilation ducts and filters in the air conditioning packs are likely the reason why the presence of TCPs has not been demonstrated in cabin air. It was recommended that this needed to be verified in aircraft.

The Orbital Workshop Waste Management Compartment

NASA Technical Reports Server (NTRS)

1972-01-01

This image is a wide-angle view of the Orbital Workshop waste management compartment. The waste management facilities presented a unique challenge to spacecraft designers. In addition to collection of liquid and solid human wastes, there was a medical requirement to dry all solid human waste products and to return the residue to Earth for examination. Liquid human waste (urine) was frozen for return to Earth. Total quantities of each astronaut's liquid and solid wastes were precisely measured. Cabin air was drawn into the toilet, shown on the wall at right in this photograph, and over the waste products to generate a flow of the waste in the desired direction. The air was then filtered for odor control and antiseptic purposes prior to being discharged back into the cabin.

Skylab

NASA Image and Video Library

1972-05-01

This image is a wide-angle view of the Orbital Workshop waste management compartment. The waste management facilities presented a unique challenge to spacecraft designers. In addition to collection of liquid and solid human wastes, there was a medical requirement to dry all solid human waste products and to return the residue to Earth for examination. Liquid human waste (urine) was frozen for return to Earth. Total quantities of each astronaut's liquid and solid wastes were precisely measured. Cabin air was drawn into the toilet, shown on the wall at right in this photograph, and over the waste products to generate a flow of the waste in the desired direction. The air was then filtered for odor control and antiseptic purposes prior to being discharged back into the cabin.

Source identification of PM10 pollution in subway passenger cabins using positive matrix factorization

NASA Astrophysics Data System (ADS)

Park, Duckshin; Oh, Miseok; Yoon, Younghun; Park, Eunyoung; Lee, Kiyoung

2012-03-01

Monitoring the air quality in subway passenger cabins is important because of the large number of passengers and potentially high levels of air pollution. This report characterized PM10 levels in subway cabins in Seoul, Korea, and identified PM10 sources using elemental analysis and receptor modeling. PM10 levels in subway cabins were continuously measured using a light scattering monitor during rush and non-rush hours. A total of 41 measurements were taken during rush and non-rush hours, and the measurements were repeated in all four seasons. Filter samples were also collected for elemental composition analysis. Major PM10 sources were identified using positive matrix factorization (PMF). The in-cabin PM10 concentrations were the highest in the winter at 152.8 μg m-3 during rush hours and 90.2 μg m-3 during non-rush hours. While PM10 levels were higher during rush hours than during non-rush hours in three seasons (excluding summer), these levels were not associated with number of passenger. Elemental analysis showed that the PM10 was composed of 52.5% inorganic elements, 10.2% anions, and 37.3% other. Fe was the most abundant element and significantly correlated (p < 0.01) with Mn (r = 0.97), Ti (r = 0.91), Cr (r = 0.88), Ni (r = 0.89), and Cu (r = 0.88). Fe, Mn, Cr, and Cu are indicators of railroad-related PM10 sources. The PM10 sources characterized by PMF were soil and road dust sources (27.2%), railroad-related sources (47.6%), secondary nitrate sources (16.2%), and a chlorine factor mixed with a secondary sulfate source (9.1%). Overall, railroad-related sources contributed the most PM10 to subway cabin air.

Health and perception of cabin air quality among Swedish commercial airline crew.

PubMed

Lindgren, T; Norbäck, D

2005-01-01

Health symptoms and perception of cabin air quality (CAQ) among commercial cabin crew were studied as a function of personal risk factors, occupation, and work on intercontinental flights with exposure to environmental tobacco smoke (ETS). A standardized questionnaire (MM 040 NA) was mailed in February to March 1997 to all Stockholm airline crew on duty in a Scandinavian airline (n=1857), and to office workers from the same airline (n=218). During this time, smoking was allowed only on intercontinental flights. The participation rate was 81% (n=1513) by the airline crew, and 77% (n=168) by the office group. Statistical analysis was performed by multiple logistic regression analysis, controlling for age, gender, atopy, current smoking habits, and occupation. The most common symptoms among airline crew were: fatigue (21%), nasal symptoms (15%), eye irritation (11%), dry or flushed facial skin (12%), and dry/itchy skin on hands (12%). The most common complaint about CAQ was dry air (53%). Airline crew had more nasal, throat, and hand skin symptoms, than office workers did. Airline crew with a history of atopy had more nasal, throat, and dermal face and hand symptoms than other crew members did. Older airline crew members had more complaints of difficulty concentrating, but fewer complaints of dermal symptoms on the face and hands than younger crew members did. Female crew members reported more headaches than male crew members reported. Smoking was not associated with frequency of symptoms. Pilots had fewer complaints of most symptoms than other crew had. Airline crew that had been on an intercontinental flight in the week before the survey had more complaints of fatigue, heavy-headedness, and difficulty concentrating. Complaints of stuffy air and dry air were more common among airline crew than among office workers from the same airline. Female crew had more complaints of stuffy and dry air than male crew had. Older cabin crew had fewer complaints of dry air than younger crew had, and cabin crew with atopy had more complaints of dry air than other crew had. Current smokers had fewer complaints of stuffy air than non-smokers had. Airline crew that had been on a flight on which smoking was allowed in the week before the survey, had more complaints of stuffy air, dry air and passive smoking, than crew that had not been on such a flight in the preceding week had. Complaints on cabin air quality and health symptoms were common among commercial airline crew, and related to age, gender, atopy and type of work onboard. The hygienic measurements showed that the relative air humidity is very low on intercontinental flights, and particle levels are high on flights with passive smoking. This illustrates the need to improve the cabin air quality in commercial airlines. Such improvements could include better control of cabin temperature, air humidification, efficient air filtration with high efficiency particulate air filter (HEPA) filtration on all types of aircraft and sufficient air exchange rate in order to fulfil current ventilation standards.

Method of Separating Oxygen From Spacecraft Cabin Air to Enable Extravehicular Activities

NASA Technical Reports Server (NTRS)

Graf, John C.

2013-01-01

Extravehicular activities (EVAs) require high-pressure, high-purity oxygen. Shuttle EVAs use oxygen that is stored and transported as a cryogenic fluid. EVAs on the International Space Station (ISS) presently use the Shuttle cryo O2, which is transported to the ISS using a transfer hose. The fluid is compressed to elevated pressures and stored as a high-pressure gas. With the retirement of the shuttle, NASA has been searching for ways to deliver oxygen to fill the highpressure oxygen tanks on the ISS. A method was developed using low-pressure oxygen generated onboard the ISS and released into ISS cabin air, filtering the oxygen from ISS cabin air using a pressure swing absorber to generate a low-pressure (high-purity) oxygen stream, compressing the oxygen with a mechanical compressor, and transferring the high-pressure, high-purity oxygen to ISS storage tanks. The pressure swing absorber (PSA) can be either a two-stage device, or a single-stage device, depending on the type of sorbent used. The key is to produce a stream with oxygen purity greater than 99.5 percent. The separator can be a PSA device, or a VPSA device (that uses both vacuum and pressure for the gas separation). The compressor is a multi-stage mechanical compressor. If the gas flow rates are on the order of 5 to 10 lb (.2.3 to 4.6 kg) per day, the compressor can be relatively small [3 16 16 in. (.8 41 41 cm)]. Any spacecraft system, or other remote location that has a supply of lowpressure oxygen, a method of separating oxygen from cabin air, and a method of compressing the enriched oxygen stream, has the possibility of having a regenerable supply of highpressure, high-purity oxygen that is compact, simple, and safe. If cabin air is modified so there is very little argon, the separator can be smaller, simpler, and use less power.

Does the air condition system in busses spread allergic fungi into driver space?

PubMed

Sowiak, Małgorzata; Kozajda, Anna; Jeżak, Karolina; Szadkowska-Stańczyk, Irena

2018-02-01

The aim of this study was to establish whether the air-conditioning system in buses constitutes an additional source of indoor air contamination with fungi, and whether or not the fungi concentration depends on the period from the last disinfection of the system, combined with replacement of the cabin dust particle filter. The air samples to fungi analysis using impact method were taken in 30 buses (20 with an air-conditioning system, ACS; 10 with a ventilation system, VS) in two series: 1 and 22 weeks after cabin filter replacement and disinfection of the air-conditioning system. During one test in each bus were taken two samples: before the air-conditioning or ventilation system switched on and 6 min after operating of these systems. The atmospheric air was the external background (EB). After 1 week of use of the system, the fungi concentrations before starting of the ACS and VS system were 527.8 and 1053.0 cfu/m 3 , respectively, and after 22 weeks the concentrations were 351.9 and 1069.6 cfu/m 3 , respectively. While in the sample after 6 min of ACS and VS system operating, the fungi concentration after 1 week of use was 127.6 and 233.7 cfu/m 3 , respectively, and after 22 weeks it was 113.3 and 324.9 cfu/m 3 , respectively. Results do not provide strong evidence that air-conditioning system is an additional source of indoor air contamination with fungi. A longer operation of the system promoted increase of fungi concentration in air-conditioned buses only.

Advanced Supported Liquid Membranes for Carbon Dioxide Control in Cabin Applications

NASA Technical Reports Server (NTRS)

Wickham, David T.; Gleason, Kevin J.; Engel, Jeffrey R.; Chullen, Cinda

2016-01-01

The development of new, robust, life support systems is critical to NASA's continued progress in space exploration. One vital function is maintaining the carbon dioxide (CO2) concentration in the cabin at levels that do not impair the health or performance of the crew. The CO2 removal assembly (CDRA) is the current CO2 control technology on-board the International Space Station (ISS). Although the CDRA has met the needs of the ISS to date, the repeated cycling of the molecular sieve sorbent causes it to break down into small particles that clog filters or generate dust in the cabin. This reduces reliability and increases maintenance requirements. Another approach that has potential advantages over the current system is a membrane that separates CO2 from air. In this approach, cabin air contacts one side of the membrane while other side of the membrane is maintained at low pressure to create a driving force for CO2 transport across the membrane. In this application, the primary power requirement is for the pump that creates the low pressure and then pumps the CO2 to the oxygen recovery system. For such a membrane to be practical, it must have high CO2 permeation rate and excellent selectivity for CO2 over air. Unfortunately, conventional gas separation membranes do not have adequate CO2 permeability and selectivity to meet the needs of this application. However, the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous material filled with a liquid that selectively reacts with CO2 over air. In a recently completed Phase II SBIR project, Reaction Systems, Inc. fabricated an SLM that is very close to meeting permeability and selectivity objectives for use in the advanced space suit portable life support system. This paper describes work carried out to evaluate its potential for use in spacecraft cabin application.

Advanced Supported Liquid Membranes for Carbon Dioxide Control in Cabin Applications

NASA Technical Reports Server (NTRS)

Wickham, David T.; Gleason, Kevin J.; Engel, Jeffrey R.; Chullen, Cinda

2016-01-01

The development of new, robust, life support systems is critical to NASA's continued progress in space exploration. One vital function is maintaining the carbon dioxide (CO2) concentration in the cabin at levels that do not impair the health or performance of the crew. The carbon dioxide removal assembly (CDRA) is the current CO2 control technology on-board the International Space Station (ISS). Although the CDRA has met the needs of the ISS to date, the repeated cycling of the molecular sieve sorbent causes it to break down into small particles that clog filters or generate dust in the cabin. This reduces reliability and increases maintenance requirements. Another approach that has potential advantages over the current system is a membrane that separates CO2 from air. In this approach, cabin air contacts one side of the membrane while other side of the membrane is maintained at low pressure to create a driving force for CO2 transport across the membrane. In this application, the primary power requirement is for the pump that creates the low pressure and then pumps the CO2 to the oxygen recovery system. For such a membrane to be practical, it must have high CO2 permeation rate and excellent selectivity for CO2 over air. Unfortunately, conventional gas separation membranes do not have adequate CO2 permeability and selectivity to meet the needs of this application. However, the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous material filled with a liquid that selectively reacts with CO2 over air. In a recently completed Phase II SBIR project, Reaction Systems, Inc. fabricated an SLM that is very close to meeting permeability and selectivity objectives for use in the Portable Life Support System (PLSS). This paper describes work carried out to evaluate its potential for use in the cabin.

Evaluation of retrofit crankcase ventilation controls and diesel oxidation catalysts for reducing air pollution in school buses

NASA Astrophysics Data System (ADS)

Trenbath, Kim; Hannigan, Michael P.; Milford, Jana B.

2009-12-01

This study evaluates the effect of retrofit closed crankcase ventilation filters (CCFs) and diesel oxidation catalysts (DOCs) on the in-cabin air quality in transit-style diesel school buses. In-cabin pollution levels were measured on three buses from the Pueblo, CO District 70 fleet. Monitoring was conducted while buses were driven along their regular routes, with each bus tested three times before and three times after installation of control devices. Ultrafine number concentrations in the school bus cabins were 33-41% lower, on average, after the control devices were installed. Mean mass concentrations of particulate matter less than 2.5 μm in diameter (PM2.5) were 56% lower, organic carbon (OC) 41% lower, elemental carbon (EC) 85% lower, and formaldehyde 32% lower after control devices were installed. While carbon monoxide concentrations were low in all tests, mean concentrations were higher after control devices were installed than in pre-retrofit tests. Reductions in number, OC, and formaldehyde concentrations were statistically significant, but reductions in PM2.5 mass were not. Even with control devices installed, during some runs PM2.5 and OC concentrations in the bus cabins were elevated compared to ambient concentrations observed in the area. OC concentrations inside the bus cabins ranged from 22 to 58 μg m -3 before and 13 to 33 μg m -3 after control devices were installed. OC concentrations were correlated with particle-bound organic tracers for lubricating oil emissions (hopanes) and diesel fuel and tailpipe emissions (polycyclic aromatic hydrocarbons (PAH) and aliphatic hydrocarbons). Mean concentrations of hopanes, PAH, and aliphatic hydrocarbons were lower by 37, 50, and 43%, respectively, after the control devices were installed, suggesting that both CCFs and DOCs were effective at reducing in-cabin OC concentrations.

Determination of polybrominated diphenyl ethers (PBDEs) in dust samples collected in air conditioning filters of different usage - method development.

PubMed

Śmiełowska, M; Zabiegała, B

2018-06-19

This study presents the results of studies aimed at the development of an analytical procedure for separation, identification, and determination of PBDEs compounds in dust samples collected from automotive cabin air filters and samples collected from filters installed as part of the air purification system in academic facilities. Ultrasound-assisted dispersive solid phase extraction (UA-dSPE) was found to perform better in terms of extract purification than the conventional SPE technique. GC-EIMS was used for final determination of analytes. The concentrations of PBDEs in car filters ranged from < LOD to 688 ng/g while from < LOD to 247 ng/g in dust from air conditioning filters. BDE-47 and BDE-100 were reported the dominating congeners. The estimated exposure to PBDEs via ingestion of dust from car filters varied from 0.00022 to 0.012 ng/day in toddlers and from 0.000036 to 0.0029 ng/day in adults; dust from air conditioning filters: from 0.017 to 0.25 ng/day in toddlers and from 0.0029 to 0.042 ng/day. In addition, an attempt was made at extracting PBDEs from a dust samples using the matrix solid-phase dispersion (MSPD) technique as a promising alternative to conventional SPE separations. Copyright © 2018 Elsevier B.V. All rights reserved.

Perception of cabin air quality in airline crew related to air humidification, on intercontinental flights.

PubMed

Lindgren, T; Norbäck, D; Wieslander, G

2007-06-01

The influence of air humidification in aircraft, on perception of cabin air quality among airline crew (N = 71) was investigated. In-flight investigations were performed in the forward part and in the aft part on eight intercontinental flights with one Boeing 767 individually, equipped with an evaporation humidifier combined with a dehumidifying unit, to reduce accumulation of condensed water in the wall construction. Four flights had the air humidification active when going out, and turned off on the return flight. The four others had the inverse humidification sequence. The sequences were randomized, and double blind. Air humidification increased relative air humidity (RH) by 10% in forward part, and by 3% in aft part of the cabin and in the cockpit. When the humidification device was active, the cabin air was perceived as being less dry (P = 0.008), and fresher (P = 0.002). The mean concentration of viable bacteria (77-108 cfu/m(3)), viable molds (74-84 cfu/m(3)), and respirable particles (1-8 microg/m3) was low, both during humidified and non-humidified flights. On flights with air humidification, there were less particles in the forward part of the aircraft (P = 0.01). In conclusion, RH can be slightly increased by using ceramic evaporation humidifier, without any measurable increase of microorganisms in cabin air. The cabin air quality was perceived as being better with air humidification. PRACTICAL IMPLICATION: Relative air humidity is low (10-20%) during intercontinental flights, and can be increased by using ceramic evaporation humidifier, without any measurable increase of microorganism in cabin air. Air humidification could increase the sensation of better cabin air quality.

Computational fluid dynamics modeling of transport and deposition of pesticides in an aircraft cabin

PubMed Central

Isukapalli, Sastry S.; Mazumdar, Sagnik; George, Pradeep; Wei, Binnian; Jones, Byron; Weisel, Clifford P.

2015-01-01

Spraying of pesticides in aircraft cabins is required by some countries as part of a disinsection process to kill insects that pose a public health threat. However, public health concerns remain regarding exposures of cabin crew and passengers to pesticides in aircraft cabins. While large scale field measurements of pesticide residues and air concentrations in aircraft cabins scenarios are expensive and time consuming, Computational Fluid Dynamics (CFD) models provide an effective alternative for characterizing concentration distributions and exposures. This study involved CFD modeling of a twin-aisle 11 row cabin mockup with heated manikins, mimicking a part of a fully occupied Boeing 767 cabin. The model was applied to study the flow and deposition of pesticides under representative scenarios with different spraying patterns (sideways and overhead) and cabin air exchange rates (low and high). Corresponding spraying experiments were conducted in the cabin mockup, and pesticide deposition samples were collected at the manikin’s lap and seat top for a limited set of five seats. The CFD model performed well for scenarios corresponding to high air exchange rates, captured the concentration profiles for middle seats under low air exchange rates, and underestimated the concentrations at window seats under low air exchange rates. Additionally, both the CFD and experimental measurements showed no major variation in deposition characteristics between sideways and overhead spraying. The CFD model can estimate concentration fields and deposition profiles at very high resolutions, which can be used for characterizing the overall variability in air concentrations and surface loadings. Additionally, these model results can also provide a realistic range of surface and air concentrations of pesticides in the cabin that can be used to estimate potential exposures of cabin crew and passengers to these pesticides. PMID:25642134

Experimental studies of thermal environment and contaminant transport in a commercial aircraft cabin with gaspers on.

PubMed

Li, B; Duan, R; Li, J; Huang, Y; Yin, H; Lin, C-H; Wei, D; Shen, X; Liu, J; Chen, Q

2016-10-01

Gaspers installed in commercial airliner cabins are used to improve passengers' thermal comfort. To understand the impact of gasper airflow on the air quality in a cabin, this investigation measured the distributions of air velocity, air temperature, and gaseous contaminant concentration in five rows of the economy-class section of an MD-82 commercial aircraft. The gaseous contaminant was simulated using SF6 as a tracer gas with the source located at the mouth of a seated manikin close to the aisle. Two-fifths of the gaspers next to the aisle were turned on in the cabin, and each of them supplied air at a flow rate of 0.66 l/s. The airflow rate in the economy-class cabin was controlled at 10 l/s per passenger. Data obtained in a previous study of the cabin with all gaspers turned off were used for comparison. The results show that the jets from the gaspers had a substantial impact on the air velocity and contaminant transport in the cabin. The air velocity in the cabin was higher, and the air temperature slightly more uniform, when the gaspers were on than when they were off, but turning on the gaspers may not have improved the air quality. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Aircraft cabin air quality: an overview [correction of overvier].

PubMed

Rayman, R B

2001-03-01

In recent years, there have been increasing complaints from cockpit crew, cabin crew, and passengers that the cabin air quality of commercial aircraft is deficient. A myriad of complaints including headache, fatigue, fever, and respiratory difficulties among many others have been registered, particularly by flight attendants on long haul routes. There is also much concern today regarding the transmission of contagious disease inflight, particularly tuberculosis. The unanswered question is whether these complaints are really due to poor cabin air quality or to other factors inherent inflight such as lowered barometric pressure, hypoxia, low humidity, circadian dysynchrony, work/rest cycles, vibration etc. This paper will review some aspects relevant to cabin air quality such as carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), particulates, and microorganisms as well as the cabin ventilation system to discern if there is a possible cause and effect of illness contracted inflight. The paper will conclude with recommendations on how the issue of cabin air quality may be resolved.

Numerical simulation study on air quality in aircraft cabins.

PubMed

Zhao, Yingjie; Dai, Bingrong; Yu, Qi; Si, Haiqing; Yu, Gang

2017-06-01

Air pollution is one of the main factors that affect the air quality in aircraft cabins, and the use of different air supply modes could influence the distribution of air pollutants in cabins. Based on the traditional ceiling air supply mode used on the B737NG, this study investigated another 3 different kinds of air supply modes for comparison: luggage rack air supply mode, joint mode combining ceiling and luggage rack air supply, and joint mode combining ceiling and individual air supply. Under the above 4 air supply modes, the air velocity, temperature and distribution of air pollutants in a cabin full of passengers were studied using computational fluid dynamics (CFD), and carbon dioxide (CO 2 ) and formaldehyde were selected as 2 kinds of representative air pollutants. The simulation results show that the joint mode combining ceiling and individual air supply can create a more uniform distribution of air velocity and temperature, has a better effect on the removal of CO 2 and formaldehyde, and can provide better air quality in cabins than the other 3 modes. Copyright © 2016. Published by Elsevier B.V.

Experimental investigation of thermal comfort and air quality in an automobile cabin during the cooling period

NASA Astrophysics Data System (ADS)

Kilic, M.; Akyol, S. M.

2012-08-01

The air quality and thermal comfort strongly influenced by the heat and mass transfer take place together in an automobile cabin. In this study, it is aimed to investigate and assess the effects of air intake settings (recirculation and fresh air) on the thermal comfort, air quality satisfaction and energy usage during the cooling period of an automobile cabin. For this purpose, measurements (temperature, air velocity, CO2) were performed at various locations inside the cabin. Furthermore, whole body and local responses of the human subjects were noted while skin temperatures were measured. A mathematical model was arranged in order to estimate CO2 concentration and energy usage inside the vehicle cabin and verified with experimental data. It is shown that CO2 level inside of the cabin can be greater than the threshold value recommended for the driving safety if two and more occupants exist in the car. It is also shown that an advanced climate control system may satisfy the requirements for the air quality and thermal comfort as well as to reduce the energy usage for the cooling of a vehicle cabin.

Engine bleed air reduction in DC-10

NASA Technical Reports Server (NTRS)

Newman, W. H.; Viele, M. R.

1980-01-01

An 0.8 percent fuel savings was achieved by a reduction in engine bleed air through the use of cabin air recirculation. The recirculation system was evaluated in revenue service on a DC-10. The cabin remained comfortable with reductions in cabin fresh air (engine bleed air) as much as 50 percent. Flight test verified the predicted fuel saving of 0.8 percent.

One-man electrochemical air revitalization system evaluation

NASA Technical Reports Server (NTRS)

Schbert, F. H.; Marshall, R. D.; Hallick, T. M.; Woods, R. R.

1976-01-01

A program to evaluate the performance of a one man capacity, self contained electrochemical air revitalization system was successfully completed. The technology readiness of this concept was demonstrated by characterizing the performance of this one man system over wide ranges in cabin atmospheric conditions. The electrochemical air revitalization system consists of a water vapor electrolysis module to generate oxygen from water vapor in the cabin air, and an electrochemical depolarized carbon dioxide concentrator module to remove carbon dioxide from the cabin air. A control/monitor instrumentation package that uses the electrochemical depolarized concentrator module power generated to partially offset the water vapor electrolysis module power requirements and various structural fluid routing components are also part of the system. The system was designed to meet the one man metabolic oxygen generation and carbon dioxide removal requirements, thereby controlling cabin partial pressure of oxygen at 22 kN/sq m and cabin pressure of carbon dioxide at 400 N/sq m over a wide range in cabin air relative humidity conditions.

Experimental investigation of personal air supply nozzle use in aircraft cabins.

PubMed

Fang, Zhaosong; Liu, Hong; Li, Baizhan; Baldwin, Andrew; Wang, Jian; Xia, Kechao

2015-03-01

To study air passengers' use of individual air supply nozzles in aircraft cabins, we constructed an experimental chamber which replicated the interior of a modern passenger aircraft. A series of experiments were conducted at different levels of cabin occupancy. Survey data were collected focused on the reasons for opening the nozzle, adjusting the level of air flow, and changing the direction of the air flow. The results showed that human thermal and draft sensations change over time in an aircraft cabin. The thermal sensation response was highest when the volunteers first entered the cabin and decreased over time until it stablized. Fifty-one percent of volunteers opened the nozzle to alleviate a feeling of stuffiness, and more than 50% adjusted the nozzle to improve upper body comfort. Over the period of the experiment the majority of volunteers chose to adjust their the air flow of their personal system. This confirms airline companies' decisions to install the individual aircraft ventilation systems in their aircraft indicates that personal air systems based on nozzle adjustment are essential for cabin comfort. These results will assist in the design of more efficient air distribution systems within passenger aircraft cabins where there is a need to optimize the air flow in order to efficiently improve aircraft passengers' thermal comfort and reduce energy use. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

International Space Station Bacteria Filter Element Service Life Evaluation

NASA Technical Reports Server (NTRS)

Perry, J. L.

2005-01-01

The International Space Station (ISS) uses high-efficiency particulate air filters to remove particulate matter from the cabin atmosphere. Known as bacteria filter elements (BFEs), there are 13 elements deployed on board the ISS's U.S. segment in the flight 4R assembly level. The preflight service life prediction of 1 yr for the BFEs is based upon engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS program resources. Testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are provided.

Method and apparatus for bio-regenerative life support system

NASA Technical Reports Server (NTRS)

Cullingford, Hatice S. (Inventor)

1991-01-01

A life support system is disclosed for human habitation (cabin) which has a bioregenerative capability through the use of a plant habitat (greenhouse) whereby oxygen-rich air from the greenhouse is processed and used in the cabin and carbon dioxide-rich air from the cabin is used in the greenhouse. Moisture from the air of both cabin and greenhouse is processed and reused in both. Wash water from the cabin is processed and reused in the cabin as hygiene water, and urine from the cabin is processed and used in the greenhouse. Spent water from the greenhouse is processed and reused in the greenhouse. Portions of the processing cycles are separated between cabin and greenhouse in order to reduce to a minimum cross contamination of the two habitat systems. Other portions of the processing cycles are common to both cabin and greenhouse. The use of bioregenerative techniques permits a substantial reduction of the total consumables used by the life support system.

International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Drop Testing of Returned Units

NASA Technical Reports Server (NTRS)

Green, Robert D.; Agui, Juan H.; Vijayakumar, R.; Berger, Gordon M.; Perry, Jay L.

2017-01-01

The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

Filter Efficiency and Pressure Testing of Returned ISS Bacterial Filter Elements (BFEs)

NASA Technical Reports Server (NTRS)

Green, Robert D.; Agui, Juan H.; Berger, Gordon M.; Vijayakumar, R.; Perry, Jay L.

2017-01-01

The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

Development of Test Protocols for International Space Station Particulate Filters

NASA Technical Reports Server (NTRS)

Green, Robert D.; Vijayakumar, R.; Agui, Juan H.

2014-01-01

Air quality control on the International Space Station (ISS) is a vital requirement for maintaining a clean environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of gravitational settling. The ISS Environmental Control and Life Support System (ECLSS) uses a filtration system that has been in use for over 14 years and has proven to meet this challenge. The heart of this system is a traditional High- Efficiency Particulate Air (HEPA) filter configured to interface with the rest of the life support elements and provide effective cabin filtration. Over the years, the service life of these filters has been re-evaluated based on limited post-flight tests of returned filters and risk factors. On earth, a well designed and installed HEPA filter will last for several years, e.g. in industrial and research clean room applications. Test methods for evaluating these filters are being developed on the basis of established test protocols used by the industry and the military. This paper will discuss the test methods adopted and test results on prototypes of the ISS filters. The results will assist in establishing whether the service life can be extended for these filters. Results from unused filters that have been in storage will also be presented to ascertain the shelf life and performance deterioration, if any and determine if the shelf life may be extended.

Self-Cleaning Particulate Prefilter Media

NASA Technical Reports Server (NTRS)

Weber, Olivia; Lalwani, San-jiv; Sharma, Anjal

2012-01-01

A long-term space mission requires efficient air revitalization performance to sustain the crew. Prefilter and particulate air filter media are susceptible to rapid fouling that adversely affects their performance and can lead to catastrophic failure of the air revitalization system, which may result in mission failure. For a long-term voyage, it is impractical to carry replacement particulate prefilter and filter modules due to the usual limitations in size, volume, and weight. The only solution to this problem is to reagentlessly regenerate prefilter and filter media in place. A method was developed to modify the particulate prefilter media to allow them to regenerate reagentlessly, and in place, by the application of modest thermocycled transverse or reversed airflows. The innovation may allow NASA to close the breathing air loop more efficiently, thereby sustaining the vision for manned space exploration missions of the future. A novel, self-cleaning coatings technology was developed for air filter media surfaces that allows reagentless in-place regeneration of the surface. The technology grafts thermoresponsive and nonspecific adhesion minimizing polymer nanolayer brush coatings from the prefilter media. These polymer nanolayer brush architectures can be triggered to contract and expand to generate a "pushing-off" force by the simple application of modestly thermocycled (i.e. cycling from ambient cabin temperature to 40 C) air streams. The nonspecific adhesion-minimizing properties of the coatings do not allow the particulate foulants to adhere strongly to the filter media, and thermocycled air streams applied to the media allow easy detachment and in-place regeneration of the media with minimal impact in system downtime or astronaut involvement in overseeing the process.

Performance of school bus retrofit systems: ultrafine particles and other vehicular pollutants.

PubMed

Zhang, Qunfang; Zhu, Yifang

2011-08-01

This study evaluated the performance of retrofit systems for diesel-powered school buses, a diesel oxidation catalyst (DOC) muffler and a spiracle crankcase filtration system (CFS), regarding ultrafine particles (UFPs) and other air pollutants from tailpipe emissions and inside bus cabins. Tailpipe emissions and in-cabin air pollutant levels were measured before and after retrofitting when the buses were idling and during actual pick-up/drop off routes. Retrofit systems significantly reduced tailpipe emissions with a reduction of 20-94% of total particles with both DOC and CFS installed. However, no unequivocal decrease was observed for in-cabin air pollutants after retrofitting. The AC/fan unit and the surrounding air pollutant concentrations played more important roles for determining the in-cabin air quality of school buses than did retrofit technologies. Although current retrofit systems reduce children's exposure while waiting to board at a bus station, retrofitting by itself does not protect children satisfactorily from in-cabin particle exposures. Turning on the bus engine increased in-cabin UFP levels significantly only when the wind blew from the bus' tailpipe toward its hood with its windows open. This indicated that wind direction and window position are significant factors determining how much self-released tailpipe emissions may penetrate into the bus cabin. The use of an air purifier was found to remove in-cabin particles by up to 50% which might be an alternative short-to-medium term strategy to protect children's health.

International Space Station Bacteria Filter Element Post-Flight Testing and Service Life Prediction

NASA Technical Reports Server (NTRS)

Perry, J. L.; von Jouanne, R. G.; Turner, E. H.

2003-01-01

The International Space Station uses high efficiency particulate air (HEPA) filters to remove particulate matter from the cabin atmosphere. Known as Bacteria Filter Elements (BFEs), there are 13 elements deployed on board the ISS's U.S. Segment. The pre-flight service life prediction of 1 year for the BFEs is based upon performance engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS Program resources. Thus testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are discussed. Recommendations for realizing significant savings to the ISS Program are presented.

Containing Hair During Cutting In Zero Gravity

NASA Technical Reports Server (NTRS)

Haines, Richard F.

1992-01-01

Proposed device collects loose hair during barbering and shaving in zero gravity to prevent hair clippings from contaminating cabin of spacecraft. Folds for storage, opens into clear, bubblelike plastic dome surrounding user's head, tray fits around user's throat, and fanlike ring surrounds back of neck. Device fits snugly but comfortably around neck, preventing hair from escaping to outside. Flow of air into hose connected to suction pump removes hair from bubble as cut. Filter at end of hose collects hair.

Cabin Air Quality On Board Mir and the International Space Station: A Comparison

NASA Technical Reports Server (NTRS)

Macatangay, Ariel; Perry, Jay L.

2007-01-01

The maintenance of the cabin atmosphere aboard spacecraft is critical not only to its habitability but also to its function. Ideally, air quality can be maintained by striking a proper balance between the generation and removal of contaminants. Both very dynamic processes, the balance between generation and removal can be difficult to maintain and control because the state of the cabin atmosphere is in constant evolution responding to different perturbations. Typically, maintaining a clean cabin environment on board crewed spacecraft and space habitats is the central function of the environmental control and life support (ECLS) system. While active air quality control equipment is deployed on board every vehicle to remove carbon dioxide, water vapor, and trace chemical components from the cabin atmosphere, perturbations associated with logistics, vehicle construction and maintenance, and ECLS system configuration influence the resulting cabin atmospheric quality. The air-quality data obtained from the International Space Station (ISS) and NASA-Mir programs provides a wealth of information regarding the maintenance of the cabin atmosphere aboard long-lived space habitats. A comparison of the composition of the trace chemical contaminant load is presented. Correlations between ground-based and in-flight operations that influence cabin atmospheric quality are identified and discussed, and observations on cabin atmospheric quality during the NASA-Mir expeditions and the International Space Station are explored.

Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants.

PubMed

Solbu, Kasper; Daae, Hanne Line; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag Gunnar; Lindgren, Torsten; Bakke, Berit; Lundanes, Elsa; Molander, Paal

2011-05-01

Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max

Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

DOEpatents

Farrington, Robert B.; Anderson, Ren

2001-01-01

The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

Source apportionment of airborne particles in commercial aircraft cabin environment: Contributions from outside and inside of cabin

NASA Astrophysics Data System (ADS)

Li, Zheng; Guan, Jun; Yang, Xudong; Lin, Chao-Hsin

2014-06-01

Airborne particles are an important type of air pollutants in aircraft cabin. Finding sources of particles is conducive to taking appropriate measures to remove them. In this study, measurements of concentration and size distribution of particles larger than 0.3 μm (PM>0.3) were made on nine short haul flights from September 2012 to March 2013. Particle counts in supply air and breathing zone air were both obtained. Results indicate that the number concentrations of particles ranged from 3.6 × 102 counts L-1 to 1.2 × 105 counts L-1 in supply air and breathing zone air, and they first decreased and then increased in general during the flight duration. Peaks of particle concentration were found at climbing, descending, and cruising phases in several flights. Percentages of particle concentration in breathing zone contributed by the bleed air (originated from outside) and cabin interior sources were calculated. The bleed air ratios, outside airflow rates and total airflow rates were calculated by using carbon dioxide as a ventilation tracer in five of the nine flights. The calculated results indicate that PM>0.3 in breathing zone mainly came from unfiltered bleed air, especially for particle sizes from 0.3 to 2.0 μm. And for particles larger than 2.0 μm, contributions from the bleed air and cabin interior were both important. The results would be useful for developing better cabin air quality control strategies.

International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Testing of Returned Units

NASA Technical Reports Server (NTRS)

Green, Robert D.; Agui, Juan H.; Vijayakumar, R.

2017-01-01

The air revitalization system aboard the International Space Station (ISS) provides the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation due to the microgravity environment in Low Earth Orbit (LEO). The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Adsorption (HEPA) media filters deployed at multiple locations in each U.S. Segment module; these filters are referred to as Bacterial Filter Elements, or BFEs. These filters see a replacement interval, as part of maintenance, of 2-5 years dependent on location in the ISS. In this work, we present particulate removal efficiency, pressure drop, and leak test results for a sample set of 8 BFEs returned from the ISS after filter replacement. The results can potentially be utilized by the ISS Program to ascertain whether the present replacement interval can be maintained or extended to balance the on-ground filter inventory with extension of the lifetime of ISS beyond 2024. These results can also provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

[Aerotoxic syndrome: fact or fiction?].

PubMed

de Graaf, Leroy J; Hageman, Gerard; Gouders, Bernie C M; Mulder, Michel F A

2014-01-01

Although the air from the turbine engines of commercial jet aircraft is used chiefly for propulsion some is also used to refresh and replenish air in the cabin. As a result of oil-seal leakage, pyrolysed engine oil or lubricating oil can contaminate cabin air via the aircraft's ventilation system, and flight crew and passengers can then inhale the combusted fumes. Exposure to emissions from cabin air, whether polluted or not, is associated with certain health risks. This phenomenon is known as the aerotoxic syndrome or 'cabin contamination'. The symptoms are non-specific, consisting predominantly of fatigue and mild cognitive impairment. Possible adverse health effects are attributed factors including organophosphate tricresyl phosphate, a component of aircraft engine oil that is potently neurotoxic.

In-flight cabin smoke control.

PubMed

Eklund, T I

1996-12-31

Fatal accidents originating from in-flight cabin fires comprise only about 1% of all fatal accidents in the civil jet transport fleet. Nevertheless, the impossibility of escape during flight accentuates the hazards resulting from low visibility and toxic gases. Control of combustion products in an aircraft cabin is affected by several characteristics that make the aircraft cabin environment unique. The aircraft fuselage is pressurized in flight and has an air distribution system which provides ventilation jets from the ceiling level air inlets running along the cabin length. A fixed quantity of ventilation air is metered into the cabin and air discharge is handled primarily by pressure controlling outflow valves in the rear lower part of the fuselage. Earlier airplane flight tests on cabin smoke control used generators producing minimally buoyant smoke products that moved with and served as a telltales for overall cabin ventilation flows. Analytical studies were done with localized smoke production to predict the percent of cabin length that would remain smoke-free during continuous generation. Development of a buoyant smoke generator allowed simulation of a fire plume with controllable simulated temperature and heat release rates. Tests on a Boeing 757, modified to allow smoke venting out through the top of the cabin, showed that the buoyant smoke front moved at 0.46m/s (1.5ft/sec) with and 0.27m/sec (0.9ft/sec) against, the axial ventilation airflow. Flight tests in a modified Boeing 727 showed that a ceiling level counterflow of about 0.55m/sec (1.8ft/sec) was required to arrest the forward movement of buoyant smoke. A design goal of 0.61m/s (2ft/sec) axial cabin flow would require a flow rate of 99m3/min (3500ft3/min) in a furnished Boeing 757. The current maximum fresh air cabin ventilation flow is 78m3/min (2756 ft3/min). Experimental results indicate that buoyancy effects cause smoke movement behaviour that is not predicted by traditional design analyses and flight test methodologies. Augmenting available ventilation for smoke control remains a design and safety challenge.

14 CFR 23.1109 - Turbocharger bleed air system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Turbocharger bleed air system. 23.1109... Induction System § 23.1109 Turbocharger bleed air system. The following applies to turbocharged bleed air systems used for cabin pressurization: (a) The cabin air system may not be subject to hazardous...

14 CFR 23.1109 - Turbocharger bleed air system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Turbocharger bleed air system. 23.1109... Induction System § 23.1109 Turbocharger bleed air system. The following applies to turbocharged bleed air systems used for cabin pressurization: (a) The cabin air system may not be subject to hazardous...

Three-dimensional modeling, estimation, and fault diagnosis of spacecraft air contaminants.

PubMed

Narayan, A P; Ramirez, W F

1998-01-01

A description is given of the design and implementation of a method to track the presence of air contaminants aboard a spacecraft using an accurate physical model and of a procedure that would raise alarms when certain tolerance levels are exceeded. Because our objective is to monitor the contaminants in real time, we make use of a state estimation procedure that filters measurements from a sensor system and arrives at an optimal estimate of the state of the system. The model essentially consists of a convection-diffusion equation in three dimensions, solved implicitly using the principle of operator splitting, and uses a flowfield obtained by the solution of the Navier-Stokes equations for the cabin geometry, assuming steady-state conditions. A novel implicit Kalman filter has been used for fault detection, a procedure that is an efficient way to track the state of the system and that uses the sparse nature of the state transition matrices.

Altitude exposures during commercial flight: a reappraisal.

PubMed

Hampson, Neil B; Kregenow, David A; Mahoney, Anne M; Kirtland, Steven H; Horan, Kathleen L; Holm, James R; Gerbino, Anthony J

2013-01-01

Hypobaric hypoxia during commercial air travel has the potential to cause or worsen hypoxemia in individuals with pre-existing cardiopulmonary compromise. Knowledge of cabin altitude pressures aboard contemporary flights is essential to counseling patients accurately about flying safety. The objective of the study was to measure peak cabin altitudes during U.S. domestic commercial flights on a variety of aircraft. A handheld mountaineering altimeter was carried by the investigators in the plane cabin during commercial air travel and peak cabin altitude measured. The values were then compared between aircraft models, aircraft classes, and distances flown. The average peak cabin altitude on 207 flights aboard 17 different aircraft was 6341 +/- 1813 ft (1933 m +/- 553 m), significantly higher than when measured in a similar fashion in 1988. Peak cabin altitude was significantly higher for flights longer than 750 mi (7085 +/- 801 ft) compared to shorter flights (5160 +/- 2290 ft/1573 +/- 698 m). Cabin altitude increased linearly with flight distance for flights up to 750 mi in length, but was independent of flight distance for flights exceeding 750 mi. Peak cabin altitude was less than 5000 ft (1524 m) in 70% of flights shorter than 500 mi. Peak cabin altitudes greater than 8000 ft (2438 m) were measured on approximately 10% of the total flights. Peak cabin altitude on commercial aircraft flights has risen over time. Cabin altitude is lower with flights of shorter distance. Physicians should take these factors into account when determining an individual's need for supplemental oxygen during commercial air travel.

Reduced bleed air extraction for DC-10 cabin air conditioning

NASA Technical Reports Server (NTRS)

Newman, W. H.; Viele, M. R.; Hrach, F. J.

1980-01-01

It is noted that a significant fuel savings can be achieved by reducing bleed air used for cabin air conditioning. Air in the cabin can be recirculated to maintain comfortable ventilation rates but the quality of the air tends to decrease due to entrainment of smoke and odors. Attention is given to a development system designed and fabricated under the NASA Engine Component Improvement Program to define the recirculation limit for the DC-10. It is shown that with the system, a wide range of bleed air reductions and recirculation rates is possible. A goal of 0.8% fuel savings has been achieved which results from a 50% reduction in bleed extraction from the engine.

Furry pet allergens, fungal DNA and microbial volatile organic compounds (MVOCs) in the commercial aircraft cabin environment.

PubMed

Fu, Xi; Lindgren, Torsten; Guo, Moran; Cai, Gui-Hong; Lundgren, Håkan; Norbäck, Dan

2013-06-01

There has been concern about the cabin environment in commercial aircraft. We measured cat, dog and horse allergens and fungal DNA in cabin dust and microbial volatile organic compounds (MVOCs) in cabin air. Samples were collected from two European airline companies, one with cabins having textile seats (TSC) and the other with cabins having leather seats (LSC), 9 airplanes from each company. Dust was vacuumed from seats and floors in the flight deck and different parts of the cabin. Cat (Fel d1), dog (Can f1) and horse allergens (Equ cx) were analyzed by ELISA. Five sequences of fungal DNA were analyzed by quantitative PCR. MVOCs were sampled on charcoal tubes in 42 TSC flights, and 17 compounds were analyzed by gas chromatography mass spectrometry (GC-MS) with selective ion monitoring (SIM). MVOC levels were compared with levels in homes from Nordic countries. The weight of dust was 1.8 times larger in TSC cabins as compared to LSC cabins (p < 0.001). In cabins with textile seats, the geometric mean (GM) concentrations of Fel d1, Can f1 and Equ cx were 5359 ng g(-1), 6067 ng g(-1), and 13 703 ng g(-1) (GM) respectively. Levels of Fel d1, Can f1 and Equ cx were 50 times, 27 times and 75 times higher respectively, in TSC cabins as compared to LSC cabins (p < 0.001). GM levels of Aspergillus/Penicillium DNA, Aspergillus versicolor DNA, Stachybotrys chartarum DNA and Streptomyces DNA were all higher in TSC as compared to LSC (p < 0.05). The sum of MVOCs in cabin air (excluding butanols) was 3192 ng m(-3) (GM), 3.7 times higher than in homes (p < 0.001) and 2-methyl-1-butanol and 3-methyl-1-butanol concentrations were 15-17 times higher as compared to homes (p < 0.001). Concentrations of isobutanol, 1-butanol, dimethyldisulfide, 2-hexanone, 2-heptanone, 3-octanone, isobutyl acetate and ethyl-2-methylbutyrate were lower in cabin air as compared to homes (p < 0.05). In conclusion, textile seats are much more contaminated by pet allergens and fungal DNA than leather seats. The use of seats with smooth surfaces should be encouraged. The MVOC levels differed between cabin air and homes.

Rationale and Methods for Archival Sampling and Analysis of Atmospheric Trace Chemical Contaminants On Board Mir and Recommendations for the International Space Station

NASA Technical Reports Server (NTRS)

Perry, J. L.; James, J. T.; Cole, H. E.; Limero, T. F.; Beck, S. W.

1997-01-01

Collection and analysis of spacecraft cabin air samples are necessary to assess the cabin air quality with respect to crew health. Both toxicology and engineering disciplines work together to achieve an acceptably clean cabin atmosphere. Toxicology is concerned with limiting the risk to crew health from chemical sources, setting exposure limits, and analyzing air samples to determine how well these limits are met. Engineering provides the means for minimizing the contribution of the various contaminant generating sources by providing active contamination control equipment on board spacecraft and adhering to a rigorous material selection and control program during the design and construction of the spacecraft. A review of the rationale and objectives for sampling spacecraft cabin atmospheres is provided. The presently-available sampling equipment and methods are reviewed along with the analytical chemistry methods employed to determine trace contaminant concentrations. These methods are compared and assessed with respect to actual cabin air quality monitoring needs. Recommendations are presented with respect to the basic sampling program necessary to ensure an acceptably clean spacecraft cabin atmosphere. Also, rationale and recommendations for expanding the scope of the basic monitoring program are discussed.

The Fate of Trace Contaminants in a Crewed Spacecraft Cabin Environment

NASA Technical Reports Server (NTRS)

Perry, Jay L.; Kayatin, Matthew J.

2016-01-01

Trace chemical contaminants produced via equipment offgassing, human metabolic sources, and vehicle operations are removed from the cabin atmosphere by active contamination control equipment and incidental removal by other air quality control equipment. The fate of representative trace contaminants commonly observed in spacecraft cabin atmospheres is explored. Removal mechanisms are described and predictive mass balance techniques are reviewed. Results from the predictive techniques are compared to cabin air quality analysis results. Considerations are discussed for an integrated trace contaminant control architecture suitable for long duration crewed space exploration missions.

Characteristics of cabin air quality in school buses in Central Texas

NASA Astrophysics Data System (ADS)

Rim, Donghyun; Siegel, Jeffrey; Spinhirne, Jarett; Webb, Alba; McDonald-Buller, Elena

This study assessed in-cabin concentrations of diesel-associated air pollutants in six school buses with diesel engines during a typical route in suburban Austin, Texas. Air exchange rates measured by SF 6 decay were 2.60-4.55 h -1. In-cabin concentrations of all pollutants measured exhibited substantial variability across the range of tests even between buses of similar age, mileage, and engine type. In-cabin NO x concentrations ranged from 44.7 to 148 ppb and were 1.3-10 times higher than roadway NO x concentrations. Mean in-cabin PM 2.5 concentrations were 7-20 μg m -3 and were generally lower than roadway levels. In-cabin concentrations exhibited higher variability during cruising mode than frequent stops. Mean in-cabin ultrafine PM number concentrations were 6100-32,000 particles cm -3 and were generally lower than roadway levels. Comparison of median concentrations indicated that in-cabin ultrafine PM number concentrations were higher than or approximately the same as the roadway concentrations, which implied that, by excluding the bias caused by local traffic, ultrafine PM levels were higher in the bus cabin than outside of the bus. Cabin pollutant concentrations on three buses were measured prior to and following the phased installation of a Donaldson Spiracle Crankcase Filtration System and a Diesel Oxidation Catalyst. Following installation of the Spiracle, the Diesel Oxidation Catalyst provided negligible or small additional reductions of in-cabin pollutant levels. In-cabin concentration decreases with the Spiracle alone ranged from 24 to 37% for NO x and 26 to 62% and 6.6 to 43% for PM 2.5 and ultrafine PM, respectively. Comparison of the ranges of PM 2.5 and ultrafine PM variations between repetitive tests suggested that retrofit installation could not always be conclusively linked to the decrease of pollutant levels in the bus cabin.

Aerospace toxicology overview: aerial application and cabin air quality.

PubMed

Chaturvedi, Arvind K

2011-01-01

Aerospace toxicology is a rather recent development and is closely related to aerospace medicine. Aerospace toxicology can be defined as a field of study designed to address the adverse effects of medications, chemicals, and contaminants on humans who fly within or outside the atmosphere in aviation or on space flights. The environment extending above and beyond the surface of the Earth is referred to as aerospace. The term aviation is frequently used interchangeably with aerospace. The focus of the literature review performed to prepare this paper was on aerospace toxicology-related subject matters, aerial application and aircraft cabin air quality. Among the important topics addressed are the following: · Aerial applications of agricultural chemicals, pesticidal toxicity, and exposures to aerially applied mixtures of chemicals and their associated formulating solvents/surfactants The safety of aerially encountered chemicals and the bioanalytical methods used to monitor exposures to some of them · The presence of fumes and smoke, as well as other contaminants that may generally be present in aircraft/space vehicle cabin air · And importantly, the toxic effects of aerially encountered contaminants, with emphasis on the degradation products of oils, fluids, and lubricants used in aircraft, and finally · Analytical methods used for monitoring human exposure to CO and HCN are addressed in the review, as are the signs and symptoms associated with exposures to these combustion gases. Although many agricultural chemical monitoring studies have been published, few have dealt with the occurrence of such chemicals in aircraft cabin air. However, agricultural chemicals do appear in cabin air; indeed, attempts have been made to establish maximum allowable concentrations for several of the more potentially toxic ones that are found in aircraft cabin air. In this article, I emphasize the need for precautionary measures to be taken to minimize exposures to aerially encountered chemicals, or aircraft cabin air contaminants and point out the need for future research to better address toxicological evaluation of aircraft-engine oil additives.

Flying the smoky skies: secondhand smoke exposure of flight attendants.

PubMed

Repace, J

2004-03-01

To assess the contribution of secondhand smoke (SHS) to aircraft cabin air pollution and flight attendants' SHS exposure relative to the general population. Published air quality measurements, modelling studies, and dosimetry studies were reviewed, analysed, and generalised. Flight attendants reported suffering greatly from SHS pollution on aircraft. Both government and airline sponsored studies concluded that SHS created an air pollution problem in aircraft cabins, while tobacco industry sponsored studies yielding similar data concluded that ventilation controlled SHS, and that SHS pollution levels were low. Between the time that non-smoking sections were established on US carriers in 1973, and the two hour US smoking ban in 1988, commercial aircraft ventilation rates had declined three times as fast as smoking prevalence. The aircraft cabin provided the least volume and lowest ventilation rate per smoker of any social venue, including stand up bars and smoking lounges, and afforded an abnormal respiratory environment. Personal monitors showed little difference in SHS exposures between flight attendants assigned to smoking sections and those assigned to non-smoking sections of aircraft cabins. In-flight air quality measurements in approximately 250 aircraft, generalised by models, indicate that when smoking was permitted aloft, 95% of the harmful respirable suspended particle (RSP) air pollution in the smoking sections and 85% of that in the non-smoking sections of aircraft cabins was caused by SHS. Typical levels of SHS-RSP on aircraft violated current (PM(2.5)) federal air quality standards approximately threefold for flight attendants, and exceeded SHS irritation thresholds by 10 to 100 times. From cotinine dosimetry, SHS exposure of typical flight attendants in aircraft cabins is estimated to have been >6-fold that of the average US worker and approximately 14-fold that of the average person. Thus, ventilation systems massively failed to control SHS air pollution in aircraft cabins. These results have implications for studies of the past and future health of flight attendants.

Flying the smoky skies: secondhand smoke exposure of flight attendants

PubMed Central

Repace, J

2004-01-01

Objective: To assess the contribution of secondhand smoke (SHS) to aircraft cabin air pollution and flight attendants' SHS exposure relative to the general population. Methods: Published air quality measurements, modelling studies, and dosimetry studies were reviewed, analysed, and generalised. Results: Flight attendants reported suffering greatly from SHS pollution on aircraft. Both government and airline sponsored studies concluded that SHS created an air pollution problem in aircraft cabins, while tobacco industry sponsored studies yielding similar data concluded that ventilation controlled SHS, and that SHS pollution levels were low. Between the time that non-smoking sections were established on US carriers in 1973, and the two hour US smoking ban in 1988, commercial aircraft ventilation rates had declined three times as fast as smoking prevalence. The aircraft cabin provided the least volume and lowest ventilation rate per smoker of any social venue, including stand up bars and smoking lounges, and afforded an abnormal respiratory environment. Personal monitors showed little difference in SHS exposures between flight attendants assigned to smoking sections and those assigned to non-smoking sections of aircraft cabins. Conclusions: In-flight air quality measurements in ~250 aircraft, generalised by models, indicate that when smoking was permitted aloft, 95% of the harmful respirable suspended particle (RSP) air pollution in the smoking sections and 85% of that in the non-smoking sections of aircraft cabins was caused by SHS. Typical levels of SHS-RSP on aircraft violated current (PM2.5) federal air quality standards ~threefold for flight attendants, and exceeded SHS irritation thresholds by 10 to 100 times. From cotinine dosimetry, SHS exposure of typical flight attendants in aircraft cabins is estimated to have been >6-fold that of the average US worker and ~14-fold that of the average person. Thus, ventilation systems massively failed to control SHS air pollution in aircraft cabins. These results have implications for studies of the past and future health of flight attendants. PMID:14985612

A simplified method for assessing particle deposition rate in aircraft cabins

NASA Astrophysics Data System (ADS)

You, Ruoyu; Zhao, Bin

2013-03-01

Particle deposition in aircraft cabins is important for the exposure of passengers to particulate matter, as well as the airborne infectious diseases. In this study, a simplified method is proposed for initial and quick assessment of particle deposition rate in aircraft cabins. The method included: collecting the inclined angle, area, characteristic length, and freestream air velocity for each surface in a cabin; estimating the friction velocity based on the characteristic length and freestream air velocity; modeling the particle deposition velocity using the empirical equation we developed previously; and then calculating the particle deposition rate. The particle deposition rates for the fully-occupied, half-occupied, 1/4-occupied and empty first-class cabin of the MD-82 commercial airliner were estimated. The results show that the occupancy did not significantly influence the particle deposition rate of the cabin. Furthermore, the simplified human model can be used in the assessment with acceptable accuracy. Finally, the comparison results show that the particle deposition rate of aircraft cabins and indoor environments are quite similar.

Advantages for passengers and cabin crew of operating a gas-phase adsorption air purifier in 11-h simulated flights.

PubMed

Strøm-Tejsen, P; Zukowska, D; Fang, L; Space, D R; Wyon, D P

2008-06-01

Experiments were carried out in a three-row, 21-seat section of a simulated aircraft cabin installed in a climate chamber to evaluate the extent to which passengers' perception of cabin air quality is affected by the operation of a gas-phase adsorption (GPA) purification unit. A total of 68 subjects, divided into four groups of 17 subjects took part in simulated 11-h flights. Each group experienced four conditions in balanced order, defined by two outside air supply rates (2.4 and 3.3 l/s per person), with and without the GPA purification unit installed in the recirculated air system, a total of 2992 subject-hours of exposure. During each flight the subjects completed questionnaires five times to provide subjective assessments of air quality, cabin environment, intensity of symptoms, and thermal comfort. Additionally, the subjects' visual acuity, finger temperature, skin dryness, and nasal peak flow were measured three times during each flight. Analysis of the subjective assessments showed that operating a GPA unit in the recirculated air provided consistent advantages with no apparent disadvantages. Operating a gas-phase adsorption (GPA) air purifier unit in the recirculated air in a simulated airplane cabin provided a clear and consistent advantage for passengers and crew that became increasingly apparent at longer flight times. This finding indicates that the expense of undertaking duly blinded field trials on revenue flights would be justified.

Prediction of car cabin environment by means of 1D and 3D cabin model

NASA Astrophysics Data System (ADS)

Fišer, J.; Pokorný, J.; Jícha, M.

2012-04-01

Thermal comfort and also reduction of energy requirements of air-conditioning system in vehicle cabins are currently very intensively investigated and up-to-date issues. The article deals with two approaches of modelling of car cabin environment; the first model was created in simulation language Modelica (typical 1D approach without cabin geometry) and the second one was created in specialized software Theseus-FE (3D approach with cabin geometry). Performance and capabilities of this tools are demonstrated on the example of the car cabin and the results from simulations are compared with the results from the real car cabin climate chamber measurements.

77 FR 41930 - Bleed Air Cleaning and Monitoring Equipment and Technology

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-17

... for the engine and auxiliary power unit bleed air supplied to the passenger cabin and flight deck of a... INFORMATION CONTACT: For questions concerning this action, contact Jim Knight, Research Planning Division, AVP... of removing oil-based contaminants from the bleed air supplied to the passenger cabin and flight deck...

Reverse Brayton Cycle with Bladeless Turbo Compressor for Automotive Environmental Cooling

NASA Technical Reports Server (NTRS)

Ganapathi, Gani B. (Inventor); Cepeda-Rizo, Juan (Inventor)

2016-01-01

An automotive cabin cooling system uses a bladeless turbocompressor driven by automobile engine exhaust to compress incoming ambient air. The compressed air is directed to an intercooler where it is cooled and then to another bladeless turbine used as an expander where the air cools as it expands and is directed to the cabin interior. Excess energy may be captured by an alternator couple to the expander turbine. The system employs no chemical refrigerant and may be further modified to include another intercooler on the output of the expander turbine to isolate the cooled cabin environment.

Rescue Shuttle Flight Re-Entry: Controlling Astronaut Thermal Exposure

NASA Technical Reports Server (NTRS)

Gillis, David B.; Hamilton, Douglas; Ilcus, Stana; Stepaniak, Phil; Polk, J. D.; Son, Chang; Bue, Grant

2008-01-01

A rescue mission for the STS-125 Hubble Telescope Repair Mission requires reentry from space with 11 crew members aboard, exceeding past cabin thermal load experience and risking crew thermal stress potentially causing cognitive performance and physiological decrements. The space shuttle crew cabin air revitalization system (ARS) was designed to support a nominal crew complement of 4 to 7 crew and 10 persons in emergencies, all in a shirt-sleeve environment. Subsequent to the addition of full pressure suits with individual cooling units, the ARS cannot maintain a stable temperature in the crew cabin during reentry thermal loads. Bulk cabin thermal models, used for rescue mission planning and analysis of crew cabin air, were unable to accurately represent crew workstation values of air flow, carbon dioxide, and heat content for the middeck. Crew temperature models suggested significantly elevated core temperatures. Planning for an STS-400 potential rescue of seven stranded crew utilized computational fluid dynamics (CFD) models to demonstrate inhomogeneous cabin thermal properties and improve analysis compared to bulk models. In the absence of monitoring of crew temperature, heart rate, metabolic rate and incomplete engineering data on the performance of the integrated cooling garment/cooling unit (ICG/CU) at cabin temperatures above 75 degrees F, related systems & models were reevaluated and tests conducted with humans in the loop. Changes to the cabin ventilation, ICU placement, crew reentry suit-donning procedures, Orbiter Program wave-off policy and post-landing power down and crew extraction were adopted. A second CFD and core temperature model incorporated the proposed changes and confirmed satisfactory cabin temperature, improved air distribution, and estimated core temperatures within safe limits. CONCLUSIONS: These changes in equipment, in-flight and post-landing procedures, and policy were implemented for the STS-400 rescue shuttle & will be implemented in any future rescue flights from the International Space Station of stranded shuttle crews.

Simulator with integrated HW and SW for prediction of thermal comfort to provide feedback to the climate control system

NASA Astrophysics Data System (ADS)

Pokorný, Jan; Kopečková, Barbora; Fišer, Jan; JÍcha, Miroslav

2018-06-01

The aim of the paper is to assemble a simulator for evaluation of thermal comfort in car cabins in order to give a feedback to the HVAC (heating, ventilation and air conditioning) system. The HW (hardware) part of simulator is formed by thermal manikin Newton and RH (relative humidity), velocity and temperature probes. The SW (software) part consists of the Thermal Comfort Analyser (using ISO 14505-2) and Virtual Testing Stand of Car Cabin defining the heat loads of car cabin. Simulator can provide recommendation for the climate control how to improve thermal comfort in cabin by distribution and directing of air flow, and also by amount of ventilation power to keep optimal temperature inside a cabin. The methods of evaluation of thermal comfort were verified by tests with 10 test subjects for summer (summer clothing, ambient air temperature 30 °C, HVAC setup: +24 °C auto) and winter conditions (winter clothing, ambient air temperature -5 °C, HVAC setup: +18 °C auto). The tests confirmed the validity of the thermal comfort evaluation using the thermal manikin and ISO 14505-2.

Formaldehyde Concentration Dynamics of the International Space Station Cabin Atmosphere

NASA Technical Reports Server (NTRS)

Perry, J. L.

2005-01-01

Formaldehyde presents a significant challenge to maintaining cabin air quality on board crewed spacecraft. Generation sources include offgassing from a variety of non-metallic materials as well as human metabolism. Because generation sources are pervasive and human health can be affected by continual exposure to low concentrations, toxicology and air quality control engineering experts jointly identified formaldehyde as a key compound to be monitored as part the International Space Station's (ISS) environmental health monitoring and maintenance program. Data acquired from in-flight air quality monitoring methods are the basis for assessing the cabin environment's suitability for long-term habitation and monitoring the performance of passive and active controls that are in place to minimize crew exposure. Formaldehyde concentration trends and dynamics served in the ISS cabin atmosphere are reviewed implications to present and future flight operations discussed.

Occupational exposure of air crews to tricresyl phosphate isomers and organophosphate flame retardants after fume events.

PubMed

Schindler, Birgit Karin; Weiss, Tobias; Schütze, Andre; Koslitz, Stephan; Broding, Horst Christoph; Bünger, Jürgen; Brüning, Thomas

2013-04-01

Aircraft cabin air can possibly be contaminated by tricresyl phosphates (TCP) from jet engine oils during fume events. o-TCP, a known neurotoxin, has been addressed to be an agent that might cause the symptoms reported by cabin crews after fume events. A total of 332 urine samples of pilots and cabin crew members in common passenger airplanes, who reported fume/odour during their last flight, were analysed for three isomers of tricresyl phosphate metabolites as well as dialkyl and diaryl phosphate metabolites of four flame retardants. None of the samples contained o-TCP metabolites above the limit of detection (LOD 0.5 μg/l). Only one sample contained metabolites of m- and p-tricresyl phosphates with levels near the LOD. Median metabolite levels of tributyl phosphate (TBP), tris-(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPP) (DBP 0.28 μg/l; BCEP 0.33 μg/l; DPP 1.1 μg/l) were found to be significantly higher than in unexposed persons from the general population. Median tris-(2-chloropropyl) phosphate (TCPP) metabolite levels were significantly not higher in air crews than in controls. Health complaints reported by air crews can hardly be addressed to o-TCP exposure in cabin air. Elevated metabolite levels for TBP, TCEP and TPP in air crews might occur due to traces of hydraulic fluid in cabin air (TBP, TPP) or due to release of commonly used flame retardants from the highly flame protected environment in the airplane. A slight occupational exposure of air crews to organophosphates was shown.

Airflow Measurement of the Car HVAC Unit Using Hot-wire Anemometry

NASA Astrophysics Data System (ADS)

Fojtlín, Miloš; Planka, Michal; Fišer, Jan; Pokorný, Jan; Jícha, Miroslav

2016-03-01

Thermal environment in a vehicular cabin significantly influence drivers' fatigue and passengers' thermal comfort. This environment is traditionally managed by HVAC cabin system that distributes air and modifies its properties. In order to simulate cabin thermal behaviour, amount of the air led through car vents must be determined. The aim of this study was to develop methodology to measure airflow from the vents, and consequently calculate corresponding air distribution coefficients. Three climatic cases were selected to match European winter, summer, and spring / fall conditions. Experiments were conducted on a test vehicle in a climatic chamber. The car HVAC system was set to automatic control mode, and the measurements were executed after the system stabilisation—each case was independently measured three times. To be able to evaluate precision of the method, the airflow was determined at the system inlet (HVAC suction) and outlet (each vent), and the total airflow values were compared. The airflow was calculated by determining a mean value of the air velocity multiplied by an area of inlet / outlet cross-section. Hot-wire anemometry was involved to measure the air velocity. Regarding the summer case, total airflow entering the cabin was around 57 l s-1 with 60 % of the air entering the cabin through dashboard vents; no air was supplied to the feet compartment. The remaining cases had the same total airflow of around 42 l s-1, and the air distribution was focused mainly on feet and windows. The inlet and outlet airflow values show a good match with a maximum mass differential of 8.3 %.

Dual direction blower system powered by solar energy to reduce car cabin temperature in open parking condition

NASA Astrophysics Data System (ADS)

Hamdan, N. S.; Radzi, M. F. M.; Damanhuri, A. A. M.; Mokhtar, S. N.

2017-10-01

El-nino phenomenon that strikes Malaysia with temperature recorded more than 35°C can lead to extreme temperature rise in car cabin up to 80°C. Various problems will arise due to this extreme rising of temperature such as the occupant are vulnerable to heat stroke, emission of benzene gas that can cause cancer due to reaction of high temperature with interior compartments, and damage of compartments in the car. The current solution available to reduce car cabin temperature including tinted of window and portable heat rejection device that are available in the market. As an alternative to reduce car cabin temperature, this project modifies the car’s air conditioning blower motor into dual direction powered by solar energy and identifies its influence to temperature inside the car, parked under scorching sun. By reducing the car cabin temperature up to 10°C which equal to 14% of reduction in the car cabin temperature, this simple proposed system aims to provide comfort to users due to its capability in improving the quality of air and moisture in the car cabin.

Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters and Packed Beds of Granular Materials

NASA Technical Reports Server (NTRS)

Perry, J. L.; Agui, J. H.; Vijayakimar, R

2016-01-01

Contaminants generated aboard crewed spacecraft by diverse sources consist of both gaseous chemical contaminants and particulate matter. Both HEPA media filters and packed beds of granular material, such as activated carbon, which are both commonly employed for cabin atmosphere purification purposes have efficacy for removing nanoparticulate contaminants from the cabin atmosphere. The phenomena associated with particulate matter removal by HEPA media filters and packed beds of granular material are reviewed relative to their efficacy for removing fine (less than 2.5 micrometers) and ultrafine (less than 0.01 micrometers) sized particulate matter. Considerations are discussed for using these methods in an appropriate configuration to provide the most effective performance for a broad range of particle sizes including nanoparticulates.

Development of an Indexing Media Filtration System for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.

2013-01-01

The effective maintenance of air quality aboard spacecraft cabins will be vital to future human exploration missions. A key component will be the air cleaning filtration system which will need to remove a broad size range of particles derived from multiple biological and material sources. In addition, during surface missions any extraterrestrial planetary dust, including dust generated by near-by ISRU equipment, which is tracked into the habitat will also need to be managed by the filtration system inside the pressurized habitat compartments. An indexing media filter system is being developed to meet the demand for long-duration missions that will result in dramatic increases in filter service life and loading capacity, and will require minimal crew involvement. The filtration system consists of three stages: an inertial impactor stage, an indexing media stage, and a high-efficiency filter stage, packaged in a stacked modular cartridge configuration. Each stage will target a specific range of particle sizes that optimize the filtration and regeneration performance of the system. An 1/8th scale and full-scale prototype of the filter system have been fabricated and have been tested in the laboratory and reduced gravity environments that simulate conditions on spacecrafts, landers and habitats. Results from recent laboratory and reduce-gravity flight tests data will be presented. The features of the new filter system may also benefit other closed systems, such as submarines, and remote location terrestrial installations where servicing and replacement of filter units is not practical.

Ozone contamination in aircraft cabins: Objectives and approach

NASA Technical Reports Server (NTRS)

Perkins, P. J.

1979-01-01

Three panels were developed to solve the problem of ozone contamination in aircraft cabins. The problem is defined from direct in-flight measurements of ozone concentrations inside and outside airliners in their normal operations. Solutions to the cabin ozone problem are discussed under two areas: (1) flight planning to avoid high ozone concentrations, and (2) ozone destruction techniques installed in the cabin air systems.

Ozone Contamination in Aircraft Cabins. Appendix B: Overview papers. Flight 8 planning to avoid high ozone

NASA Technical Reports Server (NTRS)

Belmont, A. D.

1979-01-01

The problem of preventing cabin ozone from exceeding a given standard was investigated. Statistical analysis of vertical distribution of ozone is summarized. The cost, logistics, maintenance, ability to forecast ozone, and avoiding high ozone concentrations are presented. Filtering approaches and the requirements to remove ozone toxicity are discussed.

A Cabin Air Separator for EVA Oxygen

NASA Technical Reports Server (NTRS)

Graf, John C.

2011-01-01

Presently, the Extra-Vehicular Activities (EVAs) conducted from the Quest Joint Airlock on the International Space Station use high pressure, high purity oxygen that is delivered to the Space Station by the Space Shuttle. When the Space Shuttle retires, a new method of delivering high pressure, high purity oxygen to the High Pressure Gas Tanks (HPGTs) is needed. One method is to use a cabin air separator to sweep oxygen from the cabin air, generate a low pressure/high purity oxygen stream, and compress the oxygen with a multistage mechanical compressor. A main advantage to this type of system is that the existing low pressure oxygen supply infrastructure can be used as the source of cabin oxygen. ISS has two water electrolysis systems that deliver low pressure oxygen to the cabin, as well as chlorate candles and compressed gas tanks on cargo vehicles. Each of these systems can feed low pressure oxygen into the cabin, and any low pressure oxygen source can be used as an on-board source of oxygen. Three different oxygen separator systems were evaluated, and a two stage Pressure Swing Adsorption system was selected for reasons of technical maturity. Two different compressor designs were subjected to long term testing, and the compressor with better life performance and more favorable oxygen safety characteristics was selected. These technologies have been used as the basis of a design for a flight system located in Equipment Lock, and taken to Preliminary Design Review level of maturity. This paper describes the Cabin Air Separator for EVA Oxygen (CASEO) concept, describes the separator and compressor technology trades, highlights key technology risks, and describes the flight hardware concept as presented at Preliminary Design Review (PDR)

The Effect of Solar Reflective Cover on Soak Air Temperature and Thermal Comfort of Car Parked under the Sun

NASA Astrophysics Data System (ADS)

Lahimer, A. A.; Alghoul, M. A.; Sopian, K.; Khrit, N. G.

2017-11-01

Parking a vehicle under the sun for a short period of time can rapidly increase the interior air cabin temperature no matter in clear sky days or even in partially cloudy days. These circumstances can be anxieties to car occupants upon entry. The aim of this paper is to evaluate experimentally the effect of solar reflective cover (SRC) on vehicle air temperature and cabin thermal comfort. Experimental measurements of parked cars were conducted in UKM, Bangi city, Malaysia (latitude of 2.9° N and longitude of 101.78° E) under partially cloudy day where average ambient temperature is 33°C. The experimental measurements cover the following cases: case (I): car with/ without SRC (at different measurement time); Case (II): using two identical cars concurrently (SRC versus baseline); Case (III): using two identical cars concurrently (solar reflective film (SRF) versus baseline) and Case (IV): using two identical cars concurrently (SRF versus SRC). Experimental results dedicated to case (I) revealed that the maximum cabin air temperature with SRC (39.6°C) is significantly lower than that of baseline case (57.3°C). This leads to temperature reduction improvement of 31% and the difference between the cabin and the ambient air temperature was minimized by approximately 73%. In addition, the results revealed that the air temperature at breath level of car with SRC dropped to comfort temperature (27°C) after 7 min while baseline car reached comfort temperature after 14 min. Results of the other cases are discussed inside the paper. Overall, it is learned that SRC is found superior as an efficient thermal insulation system limits solar radiation transmission into the cabin through the glass; keeps cabin air temperature close to the ambient temperature; and provide acceptable thermal environment to the occupants as they settle into their parked car.

Quantifying air distribution, ventilation effectiveness and airborne pollutant transport in an aircraft cabin mockup

NASA Astrophysics Data System (ADS)

Wang, Aijun

The health, safety and comfort of passengers during flight inspired this research into cabin air quality, which is closely related to its airflow distribution, ventilation effectiveness and airborne pollutant transport. The experimental facility is a full-scale aircraft cabin mockup. A volumetric particle tracking velocimetry (VPTV) technique was enhanced by incorporating a self-developed streak recognition algorithm. Two stable recirculation regions, the reverse flows above the seats and the main air jets from the air supply inlets formed the complicated airflow patterns inside the cabin mockup. The primary air flow was parallel to the passenger rows. The small velocity component in the direction of the cabin depth caused less net air exchange between the passenger rows than that parallel to the passenger rows. Different total air supply rate changed the developing behaviors of the main air jets, leading to different local air distribution patterns. Two indices, Local mean age of air and ventilation effectiveness factor (VEF), were measured at five levels of air supply rate and two levels of heating load. Local mean age of air decreased linearly with an increase in the air supply rate, while the VEF remained consistent when the air supply rate varied. The thermal buoyancy force from the thermal plume generated the upside plume flow, opposite to the main jet flow above the boundary seats and thus lowered the local net air exchange. The airborne transport dynamics depends on the distance between the source and the receptors, the relative location of pollutant source, and air supply rate. Exposure risk was significantly reduced with increased distance between source and receptors. Another possible way to decrease the exposure risk was to position the release source close to the exhaust outlets. Increasing the air supply rate could be an effective solution under some emergency situations. The large volume of data regarding the three-dimensional air velocities was visualized in the CAVE virtual environment. ShadowLight, a virtual reality application was used to import and navigate the velocity vectors through the virtual airspace. A real world demonstration and an active interaction with the three-dimensional air velocity data have been established.

Microbial assessment of cabin air quality on commercial airliners

NASA Technical Reports Server (NTRS)

La Duc, Myron T.; Stuecker, Tara; Bearman, Gregory; Venkateswaran, Kasthuri

2005-01-01

The microbial burdens of 69 cabin air samples collected from commercial airliners were assessed via conventional culture-dependent, and molecular-based microbial enumeration assays. Cabin air samples from each of four separate flights aboard two different carriers were collected via air-impingement. Microbial enumeration techniques targeting DNA, ATP, and endotoxin were employed to estimate total microbial burden. The total viable microbial population ranged from 0 to 3.6 x10 4 cells per 100 liters of air, as assessed by the ATP-assay. When these same samples were plated on R2A minimal medium, anywhere from 2% to 80% of these viable populations were cultivable. Five of the 29 samples examined exhibited higher cultivable counts than ATP derived viable counts, perhaps a consequence of the dormant nature (and thus lower concentration of intracellular ATP) of cells inhabiting these air cabin samples. Ribosomal RNA gene sequence analysis showed these samples to consist of a moderately diverse group of bacteria, including human pathogens. Enumeration of ribosomal genes via quantitative-PCR indicated that population densities ranged from 5 x 10 1 ' to IO 7 cells per 100 liters of air. Each of the aforementioned strategies for assessing overall microbial burden has its strengths and weaknesses; this publication serves as a testament to the power of their use in concert.

Comparison of nonwoven fiberglass and stainless steel microfiber media in aerosol coalescence filtration

NASA Astrophysics Data System (ADS)

Manzo, Gabriel

Coalescing filters are used to remove small liquid droplets from air streams. They have numerous industrial applications including dehumidification, cabin air filtration, compressed air filtration, metal working, CCV, and agriculture. In compressed air systems, oils used for lubrication of compressor parts can aerosolize into the main air stream causing potential contamination concerns for downstream applications. In many systems, humid air can present problems to sensitive equipment and sensors. As the humid air cools, small water drops condense and can disrupt components that need to be kept dry. Fibrous nonwoven filter media are commonly used to coalesce small drops into larger drops for easier removal. The coalescing performance of a medium is dependent upon several parameters including permeability, porosity, and wettability. In many coalescing filters, glass fibers are used. In this work, the properties of steel fiber media are measured to see how these properties compare to glass fiber media. Steel fiber media has different permeability, porosity and wettability to oil and water than fiber glass media. These differences can impact coalescence performance. The impact of these differences in properties on coalescence filtration performance was evaluated in a coalescence test apparatus. The overall coalescence performance of the steel and glass nonwoven fiber media are compared using a filtration efficiency and filtration index. In many cases, the stainless steel media performed comparably to fiber glass media with efficiencies near 90%. Since stainless steel media had lower pressure drops than fiber glass media, its filtration index values were significantly higher. Broader impact of this work is the use of stainless steel fiber media as an alternative to fiber glass media in applications where aerosol filtration is needed to protect the environment or sensitive equipment and sensors.

Measurement of Vehicle Air Conditioning Pull-Down Period

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, John F.; Huff, Shean P.; Moore, Larry G.

2016-08-01

Air conditioner usage was characterized for high heat-load summer conditions during short driving trips using a 2009 Ford Explorer and a 2009 Toyota Corolla. Vehicles were parked in the sun with windows closed to allow the cabin to become hot. Experiments were conducted by entering the instrumented vehicles in this heated condition and driving on-road with the windows up and the air conditioning set to maximum cooling, maximum fan speed and the air flow setting to recirculate cabin air rather than pull in outside humid air. The main purpose was to determine the length of time the air conditioner systemmore » would remain at or very near maximum cooling power under these severe-duty conditions. Because of the variable and somewhat uncontrolled nature of the experiments, they serve only to show that for short vehicle trips, air conditioning can remain near or at full cooling capacity for 10-minutes or significantly longer and the cabin may be uncomfortably warm during much of this time.« less

On the determination of the thermal comfort conditions of a metropolitan city underground railway.

PubMed

Katavoutas, George; Assimakopoulos, Margarita N; Asimakopoulos, Dimosthenis N

2016-10-01

Although the indoor thermal comfort concept has received increasing research attention, the vast majority of published work has been focused on the building environment, such as offices, residential and non-residential buildings. The present study aims to investigate the thermal comfort conditions in the unique and complex underground railway environment. Field measurements of air temperature, air humidity, air velocity, globe temperature and the number of passengers were conducted in the modern underground railway of Athens, Greece. Environmental monitoring was performed in the interior of two types of trains (air-conditioned and forced air ventilation cabins) and on selected platforms during the summer period. The thermal comfort was estimated using the PMV (predicted mean vote) and the PPD (predicted percentage dissatisfied) scales. The results reveal that the recommended thermal comfort requirements, although at relatively low percentages are met only in air-conditioned cabins. It is found that only 33% of the PPD values in air-conditioned cabins can be classified in the less restrictive comfort class C, as proposed by ISO-7730. The thermal environment is "slightly warm" in air-conditioned cabins and "warm" in forced air ventilation cabins. In addition, differences of the thermal comfort conditions on the platforms are shown to be associated with the depth and the design characteristics of the stations. The average PMV at the station with small depth is 0.9 scale points higher than that of the station with great depth. The number of passengers who are waiting at the platforms during daytime reveals a U-shaped pattern for a deep level station and an inverted course of PMV for a small depth station. Further, preliminary observations are made on the distribution of air velocity on the platforms and on the impact of air velocity on the thermal comfort conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Ozone contamination in aircraft cabins - Results from GASP data and analyses

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Nastrom, G. D.

1981-01-01

The paper reviews results from the NASA Global Atmospheric Sampling Program (GASP) pertaining to the problem of ozone contamination in commercial aircraft cabins. Specifically, analyses of GASP data have (1) confirmed the high ozone levels in aircraft cabins and documented the ratio of ozone inside and outside the cabins of two B747 airliners, including the effects of air conditioning modifications on that ratio; (2) defined ambient ozone climatology at commercial aircraft cruise altitudes, including tabulation of encounter frequency data; and (3) outlined procedures for estimating the frequency of flights encountering high cabin ozone levels using climatological ambient ozone data and verified these procedures against cabin measurements.

Ozone contamination in aircraft cabins: Results from GASP data and analyses

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Nastrom, G. D.

1981-01-01

The global atmospheric sampling program pertaining to the problem of ozone contamination in commercial airplane cabins is described. Specifically, analyses of GASP data have: confirmed the occurrence of high ozone levels in aircraft cabins and documented the ratio of ozone inside and outside the cabins of two B747 airliners, including the effects of air conditioning modifications on that ratio; defined ambient ozone climatology at commercial airplane cruise altitudes, including tabulation of encounter frequency data which were not available before GASP; and outlined procedures for estimating the frequency of flights encountering high cabin ozone levels using climatological ambient ozone data, and verified these procedures against cabin measurements.

Engine Damage to a NASA DC-8-72 Airplane From a High-Altitude Encounter With a Diffuse Volcanic Ash Cloud

NASA Technical Reports Server (NTRS)

Grindle, Thomas J.; Burcham, Frank W., Jr.

2003-01-01

The National Aeronautics and Space Administration (NASA) DC-8 airborne sciences research airplane inadvertently flew through a diffuse volcanic ash cloud of the Mt. Hekla volcano in February 2000 during a flight from Edwards Air Force Base (Edwards, California) to Kiruna, Sweden. Although the ash plume was not visible to the flight crew, sensitive research experiments and instruments detected it. In-flight performance checks and postflight visual inspections revealed no damage to the airplane or engine first-stage fan blades; subsequent detailed examination of the engines revealed clogged turbine cooling air passages. The engines were removed and overhauled. This paper presents volcanic ash plume analysis, trajectory from satellites, analysis of ash particles collected in cabin air heat exchanger filters and removed from the engines, and data from onboard instruments and engine conditions.

Measurement of Fine Particles From Mobile and Stationary Sources, and Reducing the Air Conditioner Power Consumption in Hybrid Electric Vehicles

NASA Astrophysics Data System (ADS)

Brewer, Eli Henry

We study the PM2.5and ultrafine exhaust emissions from a new natural gas-fired turbine power facility to better understand air pollution in California. To characterize the emissions from new natural gas turbines, a series of tests were performed on a GE LMS100 gas turbine. These tests included PM2.5 and wet chemical tests for SO2/SO 3 and NH3, as well as ultrafine (less than 100 nm in diameter) particulate matter measurements. The turbine exhaust had an average particle number concentration that was 2.3x103 times higher than ambient air. The majority of these particles were nanoparticles; at the 100 nm size, stack particle concentrations were about 20 times higher than ambient, and increased to 3.9x104 times higher on average in the 2.5 - 3 nm particle size range. This study also found that ammonia emissions were higher than expected, but in compliance with permit conditions. This was possibly due to an ammonia imbalance entering the catalyst, some flue gas bypassing the catalyst, or not enough catalyst volume. SO3 accounted for an average of 23% of the total sulfur oxides emissions measured. Some of the SO3 is formed in the combustion process, it is likely that the majority formed as the SO2 in the combustion products passed across the oxidizing CO catalyst and SCR catalyst. The 100 MW turbine sampled in this study emitted particle loadings similar to those previously measured from turbines in the SCAQMD area, however, the turbine exhaust contained far more particles than ambient air. The power consumed by an air conditioner accounts for a significant fraction of the total power used by hybrid and electric vehicles especially during summer. This study examined the effect of recirculation of cabin air on power consumption of mobile air conditioners both in-lab and on-road. Real time power consumption and vehicle mileage were recorded by an On Board Diagnostic monitor and carbon balance method. Vehicle mileage improved with increased cabin air recirculation. The recirculation of cabin air also significantly reduced in-cabin particle concentrations. Recirculation of cabin air is an excellent and immediate solution to increase vehicle mileage and improve cabin air quality.

[The effects of work in an air-conditioned cabin and stay in a resting chamber on blood pressure and heart rate of operators employed in deep copper mines].

PubMed

Borodulin-Nadzieja, L; Janocha, A; Pietraszkiewicz, T; Salomon, E; Stańda, M

2001-01-01

This paper is part of a wider comparative study of the heart rate, blood pressure, external and core temperature in operators of self-propelled mining machines with and without air-conditioning cabins. Two groups, each of ten operators, characterised by the similar age and duration of employment, stayed for 20 min a specially prepared resting chamber with much more advantageous microclimatic conditions. The results of our examinations (Holter heart rate and continuous blood pressure recordings, external and core temperature measurements) revealed that during the work (particularly during the increased work-load) all parameters recorded were significantly lower in air-conditioning cabins as compared with the group working without air-condition. In both groups, a complete restitution of the heart rate and blood pressure was observed after a 20-min stay in the resting chamber. During the work, a statistically significant increase in the external temperature was found in both groups of operators, whereas the increase in the core temperature was observed only in operators working without air-condition. After a 20-min stay in the resting chamber, a complete return to the normal temperature was noted only in operators working in air-conditioned cabins.

Cabin air quality: indoor pollutants and climate during intercontinental flights with and without tobacco smoking.

PubMed

Lindgren, T; Norbäck, D

2002-12-01

The aim was to determine cabin air quality and in-flight exposure for cabin attendants of specific pollutants during intercontinental flights. Measurements of air humidity, temperature, carbon dioxide (CO2), respirable particles, ozone (O3), nitrogen dioxide (NO2) and formaldehyde were performed during 26 intercontinental flights with Boeing 767-300 with and without tobacco smoking onboard. The mean temperature in cabin was 22.2 degrees C (range 17.4-26.8 degrees C), and mean relative air humidity was 6% (range 1-27%). The CO2 concentration during cruises was below the recommended limit of 1000 ppm during 96% of measured time. Mean indoor concentration of NO2 and O3, were 14.1 and 19.2 micrograms/m3, with maximum values of 37 and 66 micrograms/m3, respectively. The concentration of formaldehyde was below the detection limit (< 5 micrograms/m3), in most samples (77%), and the maximum value was 15 micrograms/m3. The mean concentration of respirable particles in the rear part of the aircraft (AFT galley area) was much higher (49 micrograms/m3) during smoking as compared with non-smoking conditions (3 micrograms/m3) (P < 0.001), with maximum values of 253 and 7 micrograms/m3. In conclusion, air humidity is very low on intercontinental flights, and the large variation of temperature shows a need for better temperature control. Tobacco smoking onboard leads to a significant pollution of respirable particles, particularly in the rear part of the cabin. The result supports the view that despite the high air exchange rate and efficient air filtration, smoking in commercial aircraft leads to a significant pollution and should be prohibited.

Aircraft skin cooling system for thermal management of onboard high power electronic equipment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashemi, A.; Dyson, E.

1996-12-31

Integration of high-power electronic devices into existing aircraft, while minimizing the impact of additional heat load on the environmental control system of the aircraft, requires innovative approaches. One such approach is to reject heat through the aircraft skin by use of internal skin ducts with enhanced surfaces. This approach requires a system level consideration of the effect of cooling ducts, inlets and outlets on the performance of the electronic equipment and effectiveness of the heat rejection system. This paper describes the development of a system-level model to evaluate the performance of electronic equipment in an aircraft cabin and heat rejectionmore » through the skin. In this model, the outer surface of the fuselage is treated as a heat exchanger. Hot air from an equipment exhaust plenum is drawn into a series of baffled ducts within the fuselage support structure, where the heat is rejected, and then recirculated into the cabin. The cooler air form the cabin is then drawn into the electronic equipment. The aircraft air conditioning unit is also modeled to provide chilled air directly into the cabin. In addition, this paper describes a series of tests which were performed to verify the model assumptions for heat dissipation from and air flow through the equipment. The tests were performed using the actual electronic equipment in a representative cabin configuration. Results indicate very good agreement between the analytical calculations for the design point and model predictions.« less

Development of an Indexing Media Filtration System for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.

2013-01-01

The effective maintenance of air quality aboard spacecraft cabins will be vital to future human exploration missions. A key component will be the air cleaning filtration system which will need to remove a broad size range of particles including skin flakes, hair and clothing fibers, other biological matter, and particulate matter derived from material and equipment wear. In addition, during surface missions any extraterrestrial planetary dust, including dust generated by near-by ISRU equipment, which is tracked into the habitat will also need to be managed by the filtration system inside the pressurized habitat compartments. An indexing media filter system is being developed to meet the demand for long-duration missions that will result in dramatic increases in filter service life and loading capacity, and will require minimal crew involvement. These features may also benefit other closed systems, such as submarines, and remote location terrestrial installations where servicing and replacement of filter units is not practical. The filtration system consists of three stages: an inertial impactor stage, an indexing media stage, and a high-efficiency filter stage, packaged in a stacked modular cartridge configuration. Each stage will target a specific range of particle sizes that optimize the filtration and regeneration performance of the system. An 1/8th scale and full-scale prototype of the filter system have been fabricated and have been tested in the laboratory and reduced gravity environments that simulate conditions on spacecrafts, landers and habitats. Results from recent laboratory and reducegravity flight tests data will be presented.

Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation.

PubMed

Brändström, Helge; Sundelin, Anna; Hoseason, Daniela; Sundström, Nina; Birgander, Richard; Johansson, Göran; Winsö, Ola; Koskinen, Lars-Owe; Haney, Michael

2017-05-12

Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

Cabin safety subject index.

DOT National Transportation Integrated Search

1984-01-01

The most frequently used Federal Aviation Administration published cabin safety information is indexed and cross referenced. This includes Federal Aviation Regulations numbers, Air Carrier Operations Bulletin numbers, Advisory Circular numbers, and O...

Characterization of a Regenerable Impactor Filter for Spacecraft Cabin Applications

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.

2015-01-01

Regenerable filters will play an important role in human exploration beyond low-Earth orbit. Life Support Systems aboard crewed spacecrafts will have to operate reliably and with little maintenance over periods of more than a year, even multiple years. Air filters are a key component of spacecraft life support systems, but they often require frequent routine maintenance. Bacterial filters aboard the International Space Station require almost weekly cleaning of the pre-filter screen to remove large lint debris captured in the microgravity environment. The source of the airborne matter which is collected on the filter screen is typically from clothing fibers, biological matter (hair, skin, nails, etc.) and material wear. Clearly a need for low maintenance filters requiring little to no crew intervention will be vital to the success of the mission. An impactor filter is being developed and tested to address this need. This filter captures large particle matter through inertial separation and impaction methods on collection surfaces, which can be automatically cleaned after they become heavily loaded. The impactor filter can serve as a pre-filter to augment the life of higher efficiency filters that capture fine and ultrafine particles. A prototype of the filter is being tested at the Particulate Filtration Laboratory at NASA Glenn Research Center to determine performance characteristics, including particle cut size and overall efficiency. Model results are presented for the flow characteristics near the orifice plate through which the particle-laden flow is accelerated as well as around the collection bands.

Ozone-initiated chemistry in an occupied simulated aircraft cabin.

PubMed

Weschler, Charles J; Wisthaler, Armin; Cowlin, Shannon; Tamás, Gyöngyi; Strøm-Tejsen, Peter; Hodgson, Alfred T; Destaillats, Hugo; Herrington, Jason; Zhang, Junfeng; Nazaroff, William W

2007-09-01

We have used multiple analytical methods to characterize the gas-phase products formed when ozone was added to cabin air during simulated 4-hour flights that were conducted in a reconstructed section of a B-767 aircraft containing human occupants. Two separate groups of 16 females were each exposed to four conditions: low air exchange (4.4 (h-1)), <2 ppb ozone; low air exchange, 61-64 ppb ozone; high air exchange (8.8 h(-1)), <2 ppb ozone; and high air exchange, 73-77 ppb ozone. The addition of ozone to the cabin air increased the levels of identified byproducts from approximately 70 to 130 ppb at the lower air exchange rate and from approximately 30 to 70 ppb at the higher air exchange rate. Most of the increase was attributable to acetone, nonanal, decanal, 4-oxopentanal (4-OPA), 6-methyl-5-hepten-2-one (6-MHO), formic acid, and acetic acid, with 0.25-0.30 mol of quantified product volatilized per mol of ozone consumed. Several of these compounds reached levels above their reported odor thresholds. Most byproducts were derived from surface reactions with occupants and their clothing, consistent with the inference that occupants were responsible for the removal of >55% of the ozone in the cabin. The observations made in this study have implications for other indoor settings. Whenever human beings and ozone are simultaneously present, one anticipates production of acetone, nonanal, decanal, 6-MHO, geranyl acetone, and 4-OPA.

Freeing Water from Viruses and Bacteria

NASA Technical Reports Server (NTRS)

2004-01-01

Four years ago, Argonide Corporation, a company focused on the research, production, and marketing of specialty nano materials, was seeking to develop applications for its NanoCeram[R] fibers. Only 2 nanometers in diameter, these nano aluminum oxide fibers possessed unusual bio-adhesive properties. When formulated into a filter material, the electropositive fibers attracted and retained electro-negative particles such as bacteria and viruses in water-based solutions. This technology caught the interest of NASA as a possible solution for improved water filtration in space cabins. NASA's Johnson Space Center awarded Sanford, Florida-based Argonide a Phase I Small Business Innovation Research (SBIR) contract to determine the feasibility of using the company's filter for purifying recycled space cabin water. Since viruses and bacteria can be carried aboard space cabins by space crews, the ability to detect and remove these harmful substances is a concern for NASA. The Space Agency also desired an improved filter to polish the effluent from condensed and waste water, producing potable drinking water. During its Phase I partnership with NASA, Argonide developed a laboratory-size filter capable of removing greater than 99.9999 percent of bacteria and viruses from water at flow rates more than 200 times faster than virus-rated membranes that remove particles by sieving. Since the new filter s pore size is rather large compared to other membranes, it is also less susceptible to clogging by small particles. In September 2002, Argonide began a Phase II SBIR project with Johnson to develop a full-size cartridge capable of serving a full space crew. This effort, which is still ongoing, enabled the company to demonstrate that its filter media is an efficient absorbent for DNA and RNA.

Development of Test Protocols for International Space Station Particulate Filters

NASA Technical Reports Server (NTRS)

Vijayakumar, R.; Green, Robert D.; Agui, Juan H.

2015-01-01

Air quality control on the International Space Station (ISS) is a vital requirement for maintaining a clean environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of gravitational settling. The ISS Environmental Control and Life Support System (ECLSS) uses a filtration system that has been in use for over 14 years and has proven to meet this challenge. The heart of this system is a traditional High-Efficiency Particulate Air (HEPA) filter configured to interface with the rest of the life support elements and provide effective cabin filtration. The filter element for this system has a non-standard cross-section with a length-to-width ratio (LW) of 6.6. A filter test setup was designed and built to meet industry testing standards. A CFD analysis was performed to initially determine the optimal duct geometry and flow configuration. Both a screen and flow straighter were added to the test duct design to improve flow uniformity and face velocity profiles were subsequently measured to confirm. Flow quality and aerosol mixing assessments show that the duct flow is satisfactory for the intended leak testing. Preliminary leak testing was performed on two different ISS filters, one with known perforations and one with limited use, and results confirmed that the testing methods and photometer instrument are sensitive enough to detect and locate compromised sections of an ISS BFE.Given the engineering constraints in designing spacecraft life support systems, it is anticipated that non-industry standard filters will be required in future designs. This work is focused on developing test protocols for testing the ISS BFE filters, but the methodology is general enough to be extended to other present and future spacecraft filters. These techniques for characterizing the test duct and perform leak testing can be applied to conducting acceptance testing and inventory testing for future manned exploration programs with air revitalization filtration needs, possibly even for in-situ filter element integrity testing for extensively long-duration missions. We plan to address the unique needs for test protocols for crewed spacecraft particulate filters by preparing the initial version of a standard, to be documented as a NASA Technical Memorandum (TM).

Increasing EDV Range through Intelligent Cabin Air Handling Strategies: Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leighton, Daniel; Rugh, John

Computational fluid dynamics (CFD) simulations of a Ford Focus Electric demonstrated that a split flow heating, ventilating and air conditioning (HVAC) system with rear recirculation ducts can reduce cabin heating loads by up to 57.4% relative to full fresh air usage under some conditions (steady state, four passengers, ambient temperature of -5 deg C). Simulations also showed that implementing a continuous recirculation fraction control system into the original equipment manufacturer (OEM) HVAC system can reduce cabin heating loads by up to 50.0% relative to full fresh air usage under some conditions (steady state, four passengers, ambient temperature of -5 degmore » C). Identified that continuous fractional recirculation control of the OEM system can provide significant energy savings for EVs at minimal additional cost, while a split flow HVAC system with rear recirculation ducts only provides minimal additional improvement at significant additional cost.« less

A critical review of reported air concentrations of organic compounds in aircraft cabins.

PubMed

Nagda, N L; Rector, H E

2003-09-01

This paper presents a review and assessment of aircraft cabin air quality studies with measured levels of volatile and semivolatile organic compounds (VOCs and SVOCs). VOC and SVOC concentrations reported for aircraft cabins are compared with those reported for residential and office buildings and for passenger compartments of other types of transportation. An assessment of measurement technologies and quality assurance procedures is included. The six studies reviewed in the paper range in coverage from two to about 30 flights per study. None of the monitored flights included any unusual or episodic events that could affect cabin air quality. Most studies have used scientifically sound methods for measurements. Study results indicate that under routine aircraft operations, contaminant levels in aircraft cabins are similar to those in residential and office buildings, with two exceptions: (1). levels of ethanol and acetone, indicators of bioeffluents and chemicals from consumer products are higher in aircraft than in home or office environments, and (2). levels of certain chlorinated hydrocarbons and fuel-related contaminants are higher in residential/office buildings than in aircraft. Similarly, ethanol and acetone levels are higher in aircraft than in other transportation modes but the levels of some pollutants, such as m-/p-xylenes, tend to be lower in aircraft.

Octafluoropropane Concentration Dynamics on Board the International Space Station

NASA Technical Reports Server (NTRS)

Perry, J. L.

2003-01-01

Since activating the International Space Station s (IS9 Service Module in November 2000, archival air quality samples have shown highly variable concentrations of octafluoropropane in the cabin. This variability has been directly linked to leakage from air conditioning systems on board the Service Module, Zvezda. While octafluoro- propane is not highly toxic, it presents a significant chal- lenge to the trace contaminant control systems. A discussion of octafluoropropane concentration dynamics is presented and the ability of on board trace contami- nant control systems to effectively remove octafluoropro- pane from the cabin atmosphere is assessed. Consideration is given to operational and logistics issues that may arise from octafluoropropane and other halo- carbon challenges to the contamination control systems as well as the potential for effecting cabin air quality.

Apollo 9 Mission image - Scott in CM cabin

NASA Image and Video Library

1969-03-03

View of Astronaut David R.Scott ,Apollo 9 Command Module pilot, inside the Command Module "Gumdrop" during the Apollo 9 earth-orbital mission. . Film magazine was D,film type was SO-368 Ektachrome with 0.460 - 0.710 micrometers film / filter transmittance response and haze filter,80mm lens.

Cabin Atmosphere Monitoring System (CAMS), pre-prototype model development continuation

NASA Technical Reports Server (NTRS)

Bursack, W. W.; Harris, W. A.

1975-01-01

The development of the Cabin Atmosphere Monitoring System (CAMS) is described. Attention was directed toward improving stability and reliability of the design using flight application guidelines. Considerable effort was devoted to the development of a temperature-stable RF/DC generator used for excitation of the quadrupole mass filter. Minor design changes were made in the preprototype model. Specific gas measurement examples are included along with a discussion of the measurement rationale employed.

Polanyi Evaluation of Adsorptive Capacities of Commercial Activated Carbons

NASA Technical Reports Server (NTRS)

Monje, Oscar; Surma, Jan M.

2017-01-01

Commercial activated carbons from Calgon (207C and OVC) and Cabot Norit (RB2 and GCA 48) were evaluated for use in spacecraft trace contaminant control filters. The Polanyi potential plots of the activated carbons were compared using to those of Barnebey-Cheney Type BD, an untreated activated carbon with similar properties as the acid-treated Barnebey-Sutcliffe Type 3032 utilized in the TCCS. Their adsorptive capacities under dry conditions were measured in a closed loop system and the sorbents were ranked for their ability to remove common VOCs found in spacecraft cabin air. This comparison suggests that these sorbents can be ranked as GCA 48 207C, OVC RB2 for the compounds evaluated.

Effect of cabin ventilation rate on ultrafine particle exposure inside automobiles.

PubMed

Knibbs, Luke D; de Dear, Richard J; Morawska, Lidia

2010-05-01

We alternately measured on-road and in-vehicle ultrafine (<100 nm) particle (UFP) concentration for 5 passenger vehicles that comprised an age range of 18 years. A range of cabin ventilation settings were assessed during 301 trips through a 4 km road tunnel in Sydney, Australia. Outdoor air flow (ventilation) rates under these settings were quantified on open roads using tracer gas techniques. Significant variability in tunnel trip average median in-cabin/on-road (I/O) UFP ratios was observed (0.08 to approximately 1.0). Based on data spanning all test automobiles and ventilation settings, a positive linear relationship was found between outdoor air flow rate and I/O ratio, with the former accounting for a substantial proportion of variation in the latter (R(2) = 0.81). UFP concentrations recorded in-cabin during tunnel travel were significantly higher than those reported by comparable studies performed on open roadways. A simple mathematical model afforded the ability to predict tunnel trip average in-cabin UFP concentrations with good accuracy. Our data indicate that under certain conditions, in-cabin UFP exposures incurred during tunnel travel may contribute significantly to daily exposure. The UFP exposure of automobile occupants appears strongly related to their choice of ventilation setting and vehicle.

Calibration of the heat balance model for prediction of car climate

NASA Astrophysics Data System (ADS)

Pokorný, Jan; Fišer, Jan; Jícha, Miroslav

2012-04-01

In the paper, the authors refer to development a heat balance model to predict car climate and power heat load. Model is developed in Modelica language using Dymola as interpreter. It is a dynamical system, which describes a heat exchange between car cabin and ambient. Inside a car cabin, there is considered heat exchange between air zone, interior and air-conditioning system. It is considered 1D heat transfer with a heat accumulation and a relative movement Sun respect to the car cabin, whilst car is moving. Measurements of the real operating conditions of gave us data for model calibration. The model was calibrated for Škoda Felicia parking-summer scenarios.

International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Operation, Recovery, and Lessons Learned

NASA Technical Reports Server (NTRS)

Balistreri, Steven F.; Steele, John W.; Caron, Mark E.; Laliberte, Yvon J.; Shaw, Laura A.

2013-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX in the ISS segments, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the ISS cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings as well as remediation and recovery of the full heat exchanger will be discussed.

International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Failures and Lessons Learned

NASA Technical Reports Server (NTRS)

Balistreri, Steven F.; Shaw, Laura A.; Laliberte, Yvon

2010-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within in the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings and potential remediation techniques will also be discussed.

Optimization Parameters of Air-conditioning and Heat Insulation Systems of a Pressurized Cabins of Long-distance Airplanes

NASA Astrophysics Data System (ADS)

Gusev, Sergey A.; Nikolaev, Vladimir N.

2018-01-01

The method for determination of an aircraft compartment thermal condition, based on a mathematical model of a compartment thermal condition was developed. Development of solution techniques for solving heat exchange direct and inverse problems and for determining confidence intervals of parametric identification estimations was carried out. The required performance of air-conditioning, ventilation systems and heat insulation depth of crew and passenger cabins were received.

Preprototype independent air revitalization subsystem

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Hallick, T. M.; Woods, R. R.

1982-01-01

The performance and maturity of a preprototype, three-person capacity, automatically controlled and monitored, self-contained independent air revitalization subsystem were evaluated. The subsystem maintains the cabin partial pressure of oxygen at 22 kPa (3.2 psia) and that of carbon dioxide at 400 Pa (3 mm Hg) over a wide range of cabin air relative humidity conditions. Consumption of water vapor by the water vapor electrolysis module also provides partial humidity control of the cabin environment. During operation, the average carbon dioxide removal efficiency at baseline conditions remained constant throughout the test at 84%. The average electrochemical depolarized concentrator cell voltage at the end of the parametric/endurance test was 0.41 V, representing a very slowly decreasing average cell voltage. The average water vapor electrolysis cell voltage increased only at a rate of 20 mu/h from the initial level of 1.67 V to the final level of 1.69 V at conclusion of the testing.

Experimental study on occupant's thermal responses under the non-uniform conditions in vehicle cabin during the heating period

NASA Astrophysics Data System (ADS)

Zhang, Wencan; Chen, Jiqing; Lan, Fengchong

2014-03-01

The existing investigations on thermal comfort mostly focus on the thermal environment conditions, especially of the air-flow field and the temperature distributions in vehicle cabin. Less attention appears to direct to the thermal comfort or thermal sensation of occupants, even to the relationship between thermal conditions and thermal sensation. In this paper, a series of experiments were designed and conducted for understanding the non-uniform conditions and the occupant's thermal responses in vehicle cabin during the heating period. To accurately assess the transient temperature distribution in cabin in common daily condition, the air temperature at a number of positions is measured in a full size vehicle cabin under natural winter environment in South China by using a discrete thermocouples network. The occupant body is divided into nine segments, the skin temperature at each segment and the occupant's local thermal sensation at the head, body, upper limb and lower limb are monitored continuously. The skin temperature is observed by using a discrete thermocouples network, and the local thermal sensation is evaluated by using a seven-point thermal comfort survey questionnaire proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc(ASHRAE) Standard. The relationship between the skin temperature and the thermal sensation is discussed and regressed by statistics method. The results show that the interior air temperature is highly non-uniform over the vehicle cabin. The locations where the occupants sit have a significant effect on the occupant's thermal responses, including the skin temperature and the thermal sensation. The skin temperature and thermal sensation are quite different between body segments due to the effect of non-uniform conditions, clothing resistance, and the human thermal regulating system. A quantitative relationship between the thermal sensation and the skin temperature at each body segment of occupant in real life traffic is presented. The investigation result indicates that the skin temperature is a robust index to evaluate the thermal sensation. Applying the skin temperature to designing and controlling parameters of the heating, ventilation and air conditioning(HVAC) system may benefit the thermal comfort and reducing energy consumption.

Determination of thermal and acoustic comfort inside a vehicle's cabin

NASA Astrophysics Data System (ADS)

Ene, Alexandra; Catalina, Tiberiu; Vartires, Andreea

2018-02-01

Thermal and acoustic comfort, inside a vehicle's cabin, are highly interconnected and can greatly influence the health of the passengers. On one hand, the H.V.A.C. system brings the interior air parameters to a comfortable value while on the other hand, it is the main source of noise. It is an intriguing task to find a balance between the two. In this paper, several types of air diffusers were used in order to optimize the ratio between thermal and acoustic interior comfort. Using complex measurements of noise and thermal comfort parameters we have determined for each type of air diffuser the sound pressure level and its impact on air temperature and air velocity.

Richards performs IFM on Cabin Air Cleaner Assembly

NASA Image and Video Library

2001-04-06

STS102-324-004 (8-21 March 2001) --- Onboard the mid deck of the Earth-orbiting Space Shuttle Discovery, astronauts James D. Wetherbee, STS-102 commander (left) and Paul W. Richards, mission specialist, are photographed performing in-flight maintenance on the cabin fan.

[Investigation of the H₂S contamination in cabin causing fishermen's eye burns].

PubMed

Qian, Ding-Guo; Wang, Jian-Yue; Wang, Yun-Ming; Ma, Yin-Xiang; Huang, Yu-Geng; Zhou, Chang-Bo; Tang, Zhi-Bo

2010-12-01

To investigate the H(2)S pollution in cabins which caused the fishermen's eye burns. Fifty-six fishing boats' H(2)S concentration was surveyed and 56 fishermen's eyes were inspected. The air samples were collected from 21 fishing boats' cabins, where the eye burns took place and the monitoring conditions met the inspection requirement, in order to confirm the concentration of H(2)S when eye burns and the systemic poisoning happened. Thirty fishing boats were divided into two groups: one was using air ventilating and spraying, the other was using naturally ventilation to find out the effective method of dispersing H(2)S. Five fishing boats were surveyed in which the fishermen had slight symptom of bulbar conjunctiva hyperemia and cough to find out the minimum concentration of H(2)S which caused the eye burns and respiratory mucosa. Among 56 fishermen who were surveyed, 46 fishermen's eyes (92 eyes) burnt and they were from 21 vessels, 10 of them (20 eyes) were moderate, 36 of them (72 eyes) were light. The concentration of H(2)S in the 21 fishing boats' cabins which caused eye burns was (99 ± 38) mg/m(3). The first measuring of the concentration of H(2)S in the 30 fishing boats in which fish were not discharged yet was (219 ± 31) mg/m(3). Air ventilating and spraying group's concentration of H(2)S was (213 ± 24) mg/m(3), while that of naturally ventilation group's was (225 ± 36) mg/m(3). Dispersing after 1 hour, the concentration of H(2)S of air ventilating and spraying group was (21 ± 3) mg/m(3), the decreased concentration was (192 ± 21) mg/m(3), fell 90%; the concentration of naturally ventilation group was (184 ± 36) mg/m(3), the decreased concentration was (41 ± 8) mg/m(3), fell 18%. The difference between the two groups' decreased concentration was significant (t = 25.627, P < 0.05). The threshold value of H(2)S concentration that could cause the eye burns was 38 mg/m(3)(exposure time 120 min). In 7 vessels, the concentration of H(2)S in the cabins was (123 ± 9) mg/m(3) where 10 fishermen's moderate eye burns happened. In other 7 vessels, the concentration of H(2)S in the cabins was (54 ± 7) mg/m(3) where 19 fishermen's light eye burns happened. The difference of H(2)S concentration between the two groups was significant (t = 14.236, P < 0.05). High H(2)S concentration and long exposure time in cabin can cause serious eye burns. The bilge air ventilation and inner cabin spraying are the effective method to clear the H(2)S in cabin within short time.

ORION Environmental Control and Life Support Systems Suit Loop and Pressure Control Analysis

NASA Technical Reports Server (NTRS)

Eckhardt, Brad; Conger, Bruce; Stambaugh, Imelda C.

2015-01-01

Under NASA's ORION Multi-Purpose Crew Vehicle (MPCV) Environmental Control and Life Support System (ECLSS) Project at Johnson Space Center's (JSC), the Crew and Thermal Systems Division has developed performance models of the air system using Thermal Desktop/FloCAD. The Thermal Desktop model includes an Air Revitalization System (ARS Loop), a Suit Loop, a Cabin Loop, and Pressure Control System (PCS) for supplying make-up gas (N2 and O2) to the Cabin and Suit Loop. The ARS and PCS are designed to maintain air quality at acceptable O2, CO2 and humidity levels as well as internal pressures in the vehicle Cabin and during suited operations. This effort required development of a suite of Thermal Desktop Orion ECLSS models to address the need for various simulation capabilities regarding ECLSS performance. An initial highly detailed model of the ARS Loop was developed in order to simulate rapid pressure transients (water hammer effects) within the ARS Loop caused by events such as cycling of the Pressurized Swing Adsorption (PSA) Beds and required high temporal resolution (small time steps) in the model during simulation. A second ECLSS model was developed to simulate events which occur over longer periods of time (over 30 minutes) where O2, CO2 and humidity levels, as well as internal pressures needed to be monitored in the cabin and for suited operations. Stand-alone models of the PCS and the Negative Pressure relief Valve (NPRV) were developed to study thermal effects within the PCS during emergency scenarios (Cabin Leak) and cabin pressurization during vehicle re-entry into Earth's atmosphere. Results from the Orion ECLSS models were used during Orion Delta-PDR (July, 2014) to address Key Design Requirements (KDR's) for Suit Loop operations for multiple mission scenarios.

Passenger well-being in airplanes.

PubMed

Hinninghofen, H; Enck, P

2006-10-30

Passenger well-being is influenced by cabin environmental conditions which interact with individual passenger characteristics like age and health conditions. Cabin environment is composed of different aspects, some of which have a direct influence on gastrointestinal functions and may directly generate nausea, such as cabin pressure, oxygen saturation, and motion or vibration. For example, it has been shown that available cabin pressure during normal flight altitude can significantly inhibit gastric emptying and induce dyspepsia-like symptoms when associated with a fibre-rich meal. Other aspects of the cabin environment such as space and variability of seating, air quality, and noise, also have been shown to modulate (reduce or increase) discomfort and nausea during flights. Individual passenger characteristics and health status also have been demonstrated to increase vulnerability to adverse health outcomes and discomfort.

Node 3 CDRA Replacement

NASA Image and Video Library

2015-05-07

ISS043E181459 (05/07/2015) – NASA astronauts Scott Kelly (left) and Terry Virts (right) work on a Carbon Dioxide Removal Assembly (CDRA) inside the station’s Japanese Experiment Module. The CDRA system works to remove carbon dioxide from the cabin air, allowing for an environmentally safe crew cabin.

Field study of air change and flow rate in six automobiles.

PubMed

Knibbs, L D; de Dear, R J; Atkinson, S E

2009-08-01

For many people, a relatively large proportion of daily exposure to a multitude of pollutants may occur inside an automobile. A key determinant of exposure is the amount of outdoor air entering the cabin (i.e. air change or flow rate). We have quantified this parameter in six passenger vehicles ranging in age from 18 years to <1 year, at three vehicle speeds and under four different ventilation settings. Average infiltration into the cabin with all operable air entry pathways closed was between 1 and 33.1 air changes per hour (ACH) at a vehicle speed of 60 km/h, and between 2.6 and 47.3 ACH at 110 km/h, with these results representing the most (2005 Volkswagen Golf) and least air-tight (1989 Mazda 121) vehicles, respectively. Average infiltration into stationary vehicles parked outdoors varied between approximately 0 and 1.4 ACH and was moderately related to wind speed. Measurements were also performed under an air recirculation setting with low fan speed, while airflow rate measurements were conducted under two non-recirculate ventilation settings with low and high fan speeds. The windows were closed in all cases, and over 200 measurements were performed. The results can be applied to estimate pollutant exposure inside vehicles. There is increasing recognition of the often disproportionately large contribution of in-vehicle pollutant exposures to overall measures. This has highlighted the need for accurate and representative quantification of determinant factors to facilitate exposure estimation and mitigation. The ventilation rate in a vehicle cabin is a key parameter affecting the transfer of pollutants from outdoors to the cabin interior, and vice-versa. New data regarding this variable are presented here, and the results indicate substantial variability in outdoor air infiltration into vehicles of differing age. The efficacy of simple measures to reduce outdoor air infiltration into 'leaky' vehicles to increase occupant protection would be a worthwhile avenue of further research.

Airliner cabin ozone: An updated review. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melton, C.E.

1989-12-01

The recent literature pertaining to ozone contamination of airliner cabins is reviewed. Measurements in airliner cabins without filters showed that ozone levels were about 50 percent of atmospheric ozone. Filters were about 90 percent effective in destroying ozone. Ozone (0.12 to 0.14 ppmv) caused mild subjective respiratory irritation in exercising men, but 0.20 to 0.30 ppmv did not have adverse effects on patients with chronic heart or lung disease. Ozone (1.0 to 2.0 ppmv) decreased survival time of influenza-infected rats and mice and suppressed the capacity of lung macrophages to destroy Listeria. Airway responses to ozone are divided into anmore » early parasympathetically mediated bronchoconstrictive phase and a later histamine-mediated congestive phase. Evidence indicates that intracellular free radicals are responsible for ozone damage and that the damage may be spread to other cells by toxic intermediate products: Antioxidants provide some protection to cells in vitro from ozone but dietary intake of antioxidant vitamins by humans has only a weak effect, if any. This review indicates that earlier findings regarding ozone toxicity do not need to be corrected. Compliance with existing FAA ozone standards appears to provide adequate protection to aircrews and passengers.« less

Automation of closed environments in space for human comfort and safety

NASA Technical Reports Server (NTRS)

1991-01-01

The development of Environmental Control and Life Support Systems (ECLSS) for Space Station Freedom, future colonization of the Moon, and Mars missions presents new challenges for present technologies. ECLSS that operate during long-duration missions must be semi-autonomous to allow crew members environmental control without constant supervision. A control system for the ECLSS must address these issues as well as being reliable. The Kansas State University Advanced Design Team is in the process of researching and designing controls for the automation of the ECLSS for Space Station Freedom and beyond. The ECLSS for Freedom is composed of six subsystems. The temperature and humidity control (THC) subsystem maintains the cabin temperature and humidity at a comfortable level. The atmosphere control and supply (ACS) subsystem insures proper cabin pressure and partial pressures of oxygen and nitrogen. To protect the space station from fire damage, the fire detection and suppression (FDS) subsystem provides fire-sensing alarms and extinguishers. The waste management (WM) subsystem compacts solid wastes for return to Earth, and collects urine for water recovery. The atmosphere revitalization (AR) subsystem removes CO2 and other dangerous contaminants from the air. The water recovery and management (WRM) subsystem collects and filters condensate from the cabin to replenish potable water supplies, and processes urine and other waste waters to replenish hygiene water supplies. These subsystems are not fully automated at this time. Furthermore, the control of these subsystems is not presently integrated; they are largely independent of one another. A fully integrated and automated ECLSS would increase astronauts' productivity and contribute to their safety and comfort.

Respiratory infections during air travel.

PubMed

Leder, K; Newman, D

2005-01-01

An increasing number of individuals undertake air travel annually. Issues regarding cabin air quality and the potential risks of transmission of respiratory infections during flight have been investigated and debated previously, but, with the advent of severe acute respiratory syndrome and influenza outbreaks, these issues have recently taken on heightened importance. Anecdotally, many people complain of respiratory symptoms following air travel. However, studies of ventilation systems and patient outcomes indicate the spread of pathogens during flight occurs rarely. In the present review, aspects of the aircraft cabin environment that affect the likelihood of transmission of respiratory pathogens on airplanes are outlined briefly and evidence for the occurrence of outbreaks of respiratory illness among airline passengers are reviewed.

Cabin air temperature of parked vehicles in summer conditions: life-threatening environment for children and pets calculated by a dynamic model

NASA Astrophysics Data System (ADS)

Horak, Johannes; Schmerold, Ivo; Wimmer, Kurt; Schauberger, Günther

2017-10-01

In vehicles that are parked, no ventilation and/or air conditioning takes place. If a vehicle is exposed to direct solar radiation, an immediate temperature rise occurs. The high cabin air temperature can threaten children and animals that are left unattended in vehicles. In the USA, lethal heat strokes cause a mean death rate of 37 children per year. In addition, temperature-sensitive goods (e.g. drugs in ambulances and veterinary vehicles) can be adversely affected by high temperatures. To calculate the rise of the cabin air temperature, a dynamic model was developed that is driven by only three parameters, available at standard meteorological stations: air temperature, global radiation and wind velocity. The transition from the initial temperature to the constant equilibrium temperature depends strongly on the configuration of the vehicle, more specifically on insulation, window area and transmission of the glass, as well as on the meteorological conditions. The comparison of the model with empirical data showed good agreement. The model output can be applied to assess the heat load of children and animals as well as temperature-sensitive goods, which are transported and/or stored in a vehicle.

The management of aircraft passenger survival in fire.

PubMed

Trimble, E J

1996-12-31

The prime factors influencing survivability from 10 major fire-related public transport aircraft accidents were assessed. Regulatory requirements were assessed against derived criteria and alternate concepts evaluated to identify a preferred strategy for enhanced survival; the provision of passenger protective breathing equipment (PPBE) was part of the twin strategy selected. PPBE tests conducted by the UK Air Accidents Investigation Branch using lung simulators and semi-controlled complex challenge combustion atmospheres generated from defined mixtures of cabin interior materials indicated that Hopcalite filters could provide satisfactory protection against carbon monoxide, hydrogen cyanide, hydrogen fluoride, hydrogen chloride, nitrogen oxides, sulphur dioxide, ammonia, acrolein, and other hydrocarbon compounds, for periods up to 30 min. Filtered levels of carbon dioxide (CO2) could be maintained within a 5% limit (inhaled atmosphere + dead space) against such atmospheres containing up to 4% CO2. Concentrations of oxygen downstream from the filters were up to some 1.0% above that present in the challenge atmospheres. Separate lung simulator tests on breathable gas (oxygen) hoods indicated that satisfactory respiratory protection could be provided for periods of up to 31 min. A possible filter modification of the passenger oxygen mask concept is discussed. It is recommended that research should be emphasized on the development of a means (e.g. PPBE) for providing in-flight smoke protection for passengers.

Measurements of ultrafine particles and other vehicular pollutants inside school buses in South Texas

NASA Astrophysics Data System (ADS)

Zhang, Qunfang; Zhu, Yifang

2010-01-01

Increasing evidence has demonstrated toxic effects of vehicular emitted ultrafine particles (UFPs, diameter < 100 nm), with the highest human exposure usually occurring on and near roadways. Children are particularly at risk due to immature respiratory systems and faster breathing rates. In this study, children's exposure to in-cabin air pollutants, especially UFPs, was measured inside four diesel-powered school buses. Two 1990 and two 2006 model year diesel-powered school buses were selected to represent the age extremes of school buses in service. Each bus was driven on two routine bus runs to study school children's exposure under different transportation conditions in South Texas. The number concentration and size distribution of UFPs, total particle number concentration, PM 2.5, PM 10, black carbon (BC), CO, and CO 2 levels were monitored inside the buses. The average total particle number concentrations observed inside the school buses ranged from 7.3 × 10 3 to 3.4 × 10 4 particles cm -3, depending on engine age and window position. When the windows were closed, the in-cabin air pollutants were more likely due to the school buses' self-pollution. The 1990 model year school buses demonstrated much higher air pollutant concentrations than the 2006 model year ones. When the windows were open, the majority of in-cabin air pollutants came from the outside roadway environment with similar pollutant levels observed regardless of engine ages. The highest average UFP concentration was observed at a bus transfer station where approximately 27 idling school buses were queued to load or unload students. Starting-up and idling generated higher air pollutant levels than the driving state. Higher in-cabin air pollutant concentrations were observed when more students were on board.

Speech intelligibility and speech quality of modified loudspeaker announcements examined in a simulated aircraft cabin.

PubMed

Pennig, Sibylle; Quehl, Julia; Wittkowski, Martin

2014-01-01

Acoustic modifications of loudspeaker announcements were investigated in a simulated aircraft cabin to improve passengers' speech intelligibility and quality of communication in this specific setting. Four experiments with 278 participants in total were conducted in an acoustic laboratory using a standardised speech test and subjective rating scales. In experiments 1 and 2 the sound pressure level (SPL) of the announcements was varied (ranging from 70 to 85 dB(A)). Experiments 3 and 4 focused on frequency modification (octave bands) of the announcements. All studies used a background noise with the same SPL (74 dB(A)), but recorded at different seat positions in the aircraft cabin (front, rear). The results quantify speech intelligibility improvements with increasing signal-to-noise ratio and amplification of particular octave bands, especially the 2 kHz and the 4 kHz band. Thus, loudspeaker power in an aircraft cabin can be reduced by using appropriate filter settings in the loudspeaker system.

International Space Station Crew Quarters Ventilation and Acoustic Design Implementation

NASA Technical Reports Server (NTRS)

Broyan, James L., Jr.; Cady, Scott M; Welsh, David A.

2010-01-01

The International Space Station (ISS) United States Operational Segment has four permanent rack sized ISS Crew Quarters (CQs) providing a private crew member space. The CQs use Node 2 cabin air for ventilation/thermal cooling, as opposed to conditioned ducted air-from the ISS Common Cabin Air Assembly (CCAA) or the ISS fluid cooling loop. Consequently, CQ can only increase the air flow rate to reduce the temperature delta between the cabin and the CQ interior. However, increasing airflow causes increased acoustic noise so efficient airflow distribution is an important design parameter. The CQ utilized a two fan push-pull configuration to ensure fresh air at the crew member's head position and reduce acoustic exposure. The CQ ventilation ducts are conduits to the louder Node 2 cabin aisle way which required significant acoustic mitigation controls. The CQ interior needs to be below noise criteria curve 40 (NC-40). The design implementation of the CQ ventilation system and acoustic mitigation are very inter-related and require consideration of crew comfort balanced with use of interior habitable volume, accommodation of fan failures, and possible crew uses that impact ventilation and acoustic performance. Each CQ required 13% of its total volume and approximately 6% of its total mass to reduce acoustic noise. This paper illustrates the types of model analysis, assumptions, vehicle interactions, and trade-offs required for CQ ventilation and acoustics. Additionally, on-orbit ventilation system performance and initial crew feedback is presented. This approach is applicable to any private enclosed space that the crew will occupy.

Experimental investigation of airborne contaminant transport by a human wake moving in a ventilated aircraft cabin

NASA Astrophysics Data System (ADS)

Poussou, Stephane B.

The air ventilation system in jetliners provides a comfortable and healthy environment for passengers. Unfortunately, the increase in global air traffic has amplified the risks presented by infectious aerosols or noxious material released during flight. Inside the cabin, air typically flows continuously from overhead outlets into sidewall exhausts in a circular pattern that minimizes secondary flow between adjacent seat rows. However, disturbances frequently introduced by individuals walking along an aisle may alter air distribution, and contribute to spreading of contaminants. Numerical simulation of these convoluted transient flow phenomena is difficult and complex, and experimental assessment of contaminant distribution in real cabins often impractical. A fundamental experimental study was undertaken to examine the transport phenomena, to validate computations and to improve air monitoring systems. A finite moving body was modeled in a 10:1 scale simplified aircraft cabin equipped with ventilation, at a Reynolds number (based on body diameter) of the order of 10,000. An experimental facility was designed and constructed to permit measurements of the ventilation and wake velocity fields using particle image velocimetry (PIV). Contaminant migration was imaged using the planar laser induced fluorescence (PLIF) technique. The effect of ventilation was estimated by comparison with a companion baseline study. Results indicate that the evolution of a downwash predominant behind finite bodies of small aspect ratio is profoundly perturbed by the ventilation flow. The reorganization of vortical structures in the near-wake leads to a shorter longitudinal recirculation region. Furthermore, mixing in the wake is modified and contaminant is observed to convect to higher vertical locations corresponding to seated passenger breathing level.

Determination of tricresyl phosphate air contamination in aircraft.

PubMed

Denola, G; Hanhela, P J; Mazurek, W

2011-08-01

Monitoring of tricresyl phosphate (TCP) contamination of cockpit air was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit air contamination suspected to originate from the engine bleed air supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. Air samples were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 air samples were analysed, from 46 different aircraft, and 48 samples were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all samples. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be <5 μg m(-3) compared with the 8-h time-weighted average exposure limit of 100 μg m(-3) for tri-o-cresyl phosphate. The highest concentrations were found at high engine power. Although TCP contamination of cabin/cockpit air has been the subject of much concern in aviation, quantitative data are sparse.

Heterogeneity of passenger exposure to air pollutants in public transport microenvironments

NASA Astrophysics Data System (ADS)

Yang, Fenhuan; Kaul, Daya; Wong, Ka Chun; Westerdahl, Dane; Sun, Li; Ho, Kin-fai; Tian, Linwei; Brimblecombe, Peter; Ning, Zhi

2015-05-01

Epidemiologic studies have linked human exposure to pollutants with adverse health effects. Passenger exposure in public transport systems contributes an important fraction of daily burden of air pollutants. While there is extensive literature reporting the concentrations of pollutants in public transport systems in different cities, there are few studies systematically addressing the heterogeneity of passenger exposure in different transit microenvironments, in cabins of different transit vehicles and in areas with different characteristics. The present study investigated PM2.5 (particulate matter with aerodynamic diameters smaller than 2.5 μm), black carbon (BC), ultrafine particles (UFP) and carbon monoxide (CO) pollutant concentrations in various public road transport systems in highly urbanized city of Hong Kong. Using a trolley case housing numerous portable air monitors, we conducted a total of 119 trips during the campaign. Transit microenvironments, classified as 1). busy and secondary roadside bus stops; 2). open and enclosed termini; 3). above- and under-ground Motor Rail Transport (MTR) platforms, were investigated and compared to identify the factors that may affect passenger exposures. The pollutants inside bus and MTR cabins were also investigated together with a comparison of time integrated exposure between the transit modes. Busy roadside and enclosed termini demonstrated the highest average particle concentrations while the lowest was found on the MTR platforms. Traffic-related pollutants BC, UFP and CO showed larger variations than PM2.5 across different microenvironments and areas confirming their heterogeneity in urban environments. In-cabin pollutant concentrations showed distinct patterns with BC and UFP high in diesel bus cabins and CO high in LPG bus cabins, suggesting possible self-pollution issues and/or penetration of on-road pollutants inside cabins during bus transit. The total passenger exposure along selected routes, showed bus trips had the potential for higher integrated passenger exposure compared to MTR trips. The present study may provide useful information to better characterize the distribution of passenger exposure pattern in health assessment studies and the results also highlight the need to formulate exposure reduction based air policies in large cities.

Scripted drives: A robust protocol for generating exposures to traffic-related air pollution

NASA Astrophysics Data System (ADS)

Patton, Allison P.; Laumbach, Robert; Ohman-Strickland, Pamela; Black, Kathy; Alimokhtari, Shahnaz; Lioy, Paul J.; Kipen, Howard M.

2016-10-01

Commuting in automobiles can contribute substantially to total traffic-related air pollution (TRAP) exposure, yet measuring commuting exposures for studies of health outcomes remains challenging. To estimate real-world TRAP exposures, we developed and evaluated the robustness of a scripted drive protocol on the NJ Turnpike and local roads between April 2007 and October 2014. Study participants were driven in a car with closed windows and open vents during morning rush hours on 190 days. Real-time measurements of PM2.5, PNC, CO, and BC, and integrated samples of NO2, were made in the car cabin. Exposure measures included in-vehicle concentrations on the NJ Turnpike and local roads and the differences and ratios of these concentrations. Median in-cabin concentrations were 11 μg/m3 PM2.5, 40 000 particles/cm3, 0.3 ppm CO, 4 μg/m3 BC, and 20.6 ppb NO2. In-cabin concentrations on the NJ Turnpike were higher than in-cabin concentrations on local roads by a factor of 1.4 for PM2.5, 3.5 for PNC, 1.0 for CO, and 4 for BC. Median concentrations of NO2 for full rides were 2.4 times higher than ambient concentrations. Results were generally robust relative to season, traffic congestion, ventilation setting, and study year, except for PNC and PM2.5, which had secular and seasonal trends. Ratios of concentrations were more stable than differences or absolute concentrations. Scripted drives can be used to generate reasonably consistent in-cabin increments of exposure to traffic-related air pollution.

Scripted drives: A robust protocol for generating exposures to traffic-related air pollution

PubMed Central

Patton, Allison P.; Laumbach, Robert; Ohman-Strickland, Pamela; Black, Kathy; Alimokhtari, Shahnaz; Lioy, Paul; Kipen, Howard M.

2016-01-01

Commuting in automobiles can contribute substantially to total traffic-related air pollution (TRAP) exposure, yet measuring commuting exposures for studies of health outcomes remains challenging. To estimate real-world TRAP exposures, we developed and evaluated the robustness of a scripted drive protocol on the NJ Turnpike and local roads between April 2007 and October 2014. Study participants were driven in a car with closed windows and open vents during morning rush hours on 190 days. Real-time measurements of PM2.5, PNC, CO, and BC, and integrated samples of NO2, were made in the car cabin. Exposure measures included in-vehicle concentrations on the NJ Turnpike and local roads and the differences and ratios of these concentrations. Median in-cabin concentrations were 11 μg/m3 PM2.5, 40 000 particles/cm3, 0.3 ppm CO, 4 μg/m3 BC, and 20.6 ppb NO2. In-cabin concentrations on the NJ Turnpike were higher than in-cabin concentrations on local roads by a factor of 1.4 for PM2.5, 3.5 for PNC, 1.0 for CO, and 4 for BC. Median concentrations of NO2 for full rides were 2.4 times higher than ambient concentrations. Results were generally robust relative to season, traffic congestion, ventilation setting, and study year, except for PNC and PM2.5, which had secular and seasonal trends. Ratios of concentrations were more stable than differences or absolute concentrations. Scripted drives can be used for generating reasonably consistent in-cabin increments of exposure to traffic-related air pollution. PMID:27642251

Carbon dioxide and water vapor production at rest and during exercise. A report on data collection for the Crew and Thermal Systems Division

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Siconolfi, Steven F.

1994-01-01

The current environmental control device in the shuttle uses lithium hydroxide (LiOH) filter canisters to remove carbon dioxide (CO2) from the cabin air, requiring several bulky filter canisters that can only be used once and must be changed frequently. To alleviate a stowage problem and decrease launch weight, the Crew and Thermal Systems Division (CTSD) at the NASA Johnson Space Center has been researching a system to be used on future shuttle missions. This system uses two beds of solid amine material to absorb CO2 and water, later desorbing them to space vacuum. In this way the air scrubbing medium is regenerable and reusable. To identify the efficacy of this regenerable CO2 removal system (RCRS), CTSD began investigations in the shuttle mockup. The purpose of this investigation was to support the CTSD program by determining mean levels of carbon dioxide and water vapor production in normal, healthy males and females age-matched with the astronaut corps. Subjects' responses were measured at rest and during exercise at intensity levels equivalent to normal shuttle operation activities. The results were used to assess the adjustments made to RCRS and are reported as a reference for future investigations in shuttle environmental control.

Integrated energy balance analysis for Space Station Freedom

NASA Technical Reports Server (NTRS)

Tandler, John

1991-01-01

An integrated simulation model is described which characterizes the dynamic interaction of the energy transport subsystems of Space Station Freedom for given orbital conditions and for a given set of power and thermal loads. Subsystems included in the model are the Electric Power System (EPS), the Internal Thermal Control System (ITCS), the External Thermal Control System (ETCS), and the cabin Temperature and Humidity Control System (THC) (which includes the avionics air cooling, cabin air cooling, and intermodule ventilation systems). Models of the subsystems were developed in a number of system-specific modeling tools and validated. The subsystem models are then combined into integrated models to address a number of integrated performance issues involving the ability of the integrated energy transport system of Space Station Freedom to provide power, controlled cabin temperature and humidity, and equipment thermal control to support operations.

Exposure to triaryl phosphates: metabolism and biomarkers of exposure.

PubMed

Furlong, Clement E

2011-01-01

The leakage of tricresyl phosphate-containing engine lubricants into aircraft cabin air, either from worn or defective engine seals or under normal operating conditions, is a serious concern for both the health and safety of the cabin occupants, since the oil contains one to five percent tricresyl phosphate (TCP) esters, known neurotoxins. The exposure of pilots is a particular concern since their impairment can affect their safe operation of the aircraft. Mass spectrometric (MS)-based protocols for documenting exposures of individuals are described that entail a rapid purification of the TCP-modified plasma enzyme butyrylcholinesterase (BChE). Following protease digestion of BChE, the modified active site peptide is characterized by MS analysis. Approaches for identifying safer engine oil additives are also described. Some general comments regarding the necessity of improving the quality and safety of the cabin air supply are presented.

Predictive Techniques for Spacecraft Cabin Air Quality Control

NASA Technical Reports Server (NTRS)

Perry, J. L.; Cromes, Scott D. (Technical Monitor)

2001-01-01

As assembly of the International Space Station (ISS) proceeds, predictive techniques are used to determine the best approach for handling a variety of cabin air quality challenges. These techniques use equipment offgassing data collected from each ISS module before flight to characterize the trace chemical contaminant load. Combined with crew metabolic loads, these data serve as input to a predictive model for assessing the capability of the onboard atmosphere revitalization systems to handle the overall trace contaminant load as station assembly progresses. The techniques for predicting in-flight air quality are summarized along with results from early ISS mission analyses. Results from groundbased analyses of in-flight air quality samples are compared to the predictions to demonstrate the technique's relative conservatism.

Finite element modal analysis of a vehicle-borne lidar cabin

NASA Astrophysics Data System (ADS)

Chen, Yafeng; Liu, Qiuwu; Wang, Jie; Hu, Shunxing; Huang, Jian

2018-02-01

Using SolidWorks software, the finite element modal analysis of a vehicle-borne pollution monitoring lidar cabin is carried out. The lidar cabin for the integrated lidar can ensure that the lidar system has good maneuverability and can effectively monitor the emission of air pollution. Since lidar is an integrated system of optics, mechanism, electricity and calculation, the performance of the cabin is directly related to the safety of the equipment and the lidar to work properly. Firstly, the cubic structure is modeled to simulate the cubic structure. Then, the model of the cabin model is analyzed by using the simulation plug-in, and the first 10 modes and natural frequencies are analyzed and recorded. The calculation results show that the cabin is dominated by bending vibration, and the amplitude area is concentrated in the opening of some windows and doors on each board. Therefore, we should increase the number of reinforcement bars or the strength of the skeleton in the vicinity of the door and window. At the same time, to avoid the resonance and ensure the precision of the optical elements and the electrical components and avoid structural damage of the cabin, the incentive frequency should be keep away from the natural frequency of the cabin. The vehicle-borne lidar system has been put into operation, and the analysis results have direct meaning to the transport of the cabin and the normal work.

The Effect of Golden Pothos in Reducing the Level of Volatile Organic Compounds in a Simulated Spacecraft Cabin

NASA Technical Reports Server (NTRS)

Ursprung, Matthew; Amiri, Azita; Kayatin, Matthew; Perry, Jay

2016-01-01

The impact of Golden Pothos on indoor air quality was studied against a simulated spacecraft trace contaminant load model, consistent with the International Space Station (ISS), containing volatile organic compounds (VOCs) and formaldehyde. Previous research provides inconclusive results on the efficacy of plant VOC removal which this projects seeks to rectify through a better experimental design. This work develops a passive system for removing common VOC's from spacecraft and household indoor air and decreasing the necessity for active cabin trace contaminant removal systems.

Effects of commercial air travel on patients with pulmonary hypertension air travel and pulmonary hypertension.

PubMed

Roubinian, Nareg; Elliott, C Gregory; Barnett, Christopher F; Blanc, Paul D; Chen, Joan; De Marco, Teresa; Chen, Hubert

2012-10-01

Limited data are available on the effects of air travel in patients with pulmonary hypertension (PH), despite their risk of physiologic compromise. We sought to quantify the incidence and severity of hypoxemia experienced by people with PH during commercial air travel. We recruited 34 participants for a prospective observational study during which cabin pressure, oxygen saturation (Sp O 2 ), heart rate, and symptoms were documented serially at multiple predefined time points throughout commercial flights. Oxygen desaturation was defined as SpO2, <85%. Median flight duration was 3.6 h (range, 1.0-7.3 h). Mean ± SD cabin pressure at cruising altitude was equivalent to the pressure 1,968 ± 371 m (6,456 ± 1,218 ft) above sea level (ASL)(maximum altitude 5 2,621 m [8,600 ft] ASL). Median change in Sp O 2 from sea level to cruising altitude was 2 4.9% (range, 2.0% to 2 15.8%). Nine subjects (26% [95% CI, 12%-38%]) experienced oxygen desaturation during flight (minimum Sp O 2 5 74%). Thirteen subjects (38%) reported symptoms during flight, of whom five also experienced desaturations. Oxygen desaturation was associated with cabin pressures equivalent to . 1,829 m (6,000 ft) ASL, ambulation, and flight duration(all P values , .05). Hypoxemia is common among people with PH traveling by air, occurring in one in four people studied. Hypoxemia was associated with lower cabin pressures, ambulation during flight, and longer flight duration. Patients with PH who will be traveling on flights of longer duration or who have a history of oxygen use, including nocturnal use only, should be evaluated for supplemental in-flight oxygen.

Airborne exposure patterns from a passenger source in aircraft cabins

PubMed Central

Bennett, James S.; Jones, Byron W.; Hosni, Mohammad H.; Zhang, Yuanhui; Topmiller, Jennifer L.; Dietrich, Watts L.

2015-01-01

Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins. PMID:26526769

In-Cabin Air Quality during Driving and Engine Idling in Air-Conditioned Private Vehicles in Hong Kong.

PubMed

Barnes, Natasha Maria; Ng, Tsz Wai; Ma, Kwok Keung; Lai, Ka Man

2018-03-27

Many people spend lengthy periods each day in enclosed vehicles in Hong Kong. However, comparably limited data is available about in-cabin air quality in air-conditioned private vehicles, and the car usage that may affect the air quality. Fifty-one vehicles were tested for particulate matter (PM 0.3 and PM 2.5 ), total volatile organic compounds (TVOCs), carbon monoxide (CO), carbon dioxide (CO₂), airborne bacteria, and fungi levels during their routine travel journey. Ten of these vehicles were further examined for PM 0.3 , PM 2.5 , TVOCs, CO, and CO₂ during engine idling. In general, during driving PM 2.5 levels in-cabin reduced overtime, but not PM 0.3 . For TVOCs, 24% vehicles exceeded the recommended Indoor Air Quality (IAQ) level in offices and public places set by the Hong Kong Environmental Protection Department. The total volatile organic compounds (TVOC) concentration positively correlated with the age of the vehicle. Carbon monoxide (CO) levels in all of the vehicles were lower than the IAQ recommendation, while 96% vehicles exceeded the recommended CO₂ level of 1000 ppmv; 16% vehicles >5000 ppmv. Microbial counts were relatively low. TVOCs levels at idle engine were higher than that during driving. Although the time we spend in vehicles is short, the potential exposure to high levels of pollutants should not be overlooked.

In-Cabin Air Quality during Driving and Engine Idling in Air-Conditioned Private Vehicles in Hong Kong

PubMed Central

Barnes, Natasha Maria; Ng, Tsz Wai; Ma, Kwok Keung; Lai, Ka Man

2018-01-01

Many people spend lengthy periods each day in enclosed vehicles in Hong Kong. However, comparably limited data is available about in-cabin air quality in air-conditioned private vehicles, and the car usage that may affect the air quality. Fifty-one vehicles were tested for particulate matter (PM0.3 and PM2.5), total volatile organic compounds (TVOCs), carbon monoxide (CO), carbon dioxide (CO2), airborne bacteria, and fungi levels during their routine travel journey. Ten of these vehicles were further examined for PM0.3, PM2.5, TVOCs, CO, and CO2 during engine idling. In general, during driving PM2.5 levels in-cabin reduced overtime, but not PM0.3. For TVOCs, 24% vehicles exceeded the recommended Indoor Air Quality (IAQ) level in offices and public places set by the Hong Kong Environmental Protection Department. The total volatile organic compounds (TVOC) concentration positively correlated with the age of the vehicle. Carbon monoxide (CO) levels in all of the vehicles were lower than the IAQ recommendation, while 96% vehicles exceeded the recommended CO2 level of 1000 ppmv; 16% vehicles >5000 ppmv. Microbial counts were relatively low. TVOCs levels at idle engine were higher than that during driving. Although the time we spend in vehicles is short, the potential exposure to high levels of pollutants should not be overlooked. PMID:29584686

Cabin Air Quality Dynamics On Board the International Space Station

NASA Technical Reports Server (NTRS)

Perry, J. L.; Peterson, B. V.

2003-01-01

Spacecraft cabin air quality is influenced by a variety of factors. Beyond normal equipment offgassing and crew metabolic loads, the vehicle s operational configuration contributes significantly to overall air quality. Leaks from system equipment and payload facilities, operational status of the atmospheric scrubbing systems, and the introduction of new equipment and modules to the vehicle all influence air quality. The dynamics associated with changes in the International Space Station's (ISS) configuration since the launch of the U.S. Segment s laboratory module, Destiny, is summarized. Key classes of trace chemical contaminants that are important to crew health and equipment performance are emphasized. The temporary effects associated with attaching each multi-purpose logistics module (MPLM) to the ISS and influence of in-flight air quality on the post-flight ground processing of the MPLM are explored.

Advancements in water vapor electrolysis technology. [for Space Station ECLSS

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Heppner, Dennis B.; Sudar, Martin

1988-01-01

The paper describes a technology development program whose goal is to develop water vapor electrolysis (WVE) hardware that can be used selectively as localized topping capability in areas of high metabolic activity without oversizing the central air revitalization system on long-duration manned space missions. The WVE will be used primarily to generate O2 for the crew cabin but also to provide partial humidity control by removing water vapor from the cabin atmosphere. The electrochemically based WVE interfaces with cabin air which is controlled in the following ranges: dry bulb temperature of 292 to 300 K; dew point temperature of 278 to 289 K; relative humidity of 25 to 75 percent; and pressure of 101 + or - 1.4 kPa. Design requirements, construction details, and results for both single-cell and multicell module testing are presented, and the preliminary sizing of a multiperson subsystem is discussed.

Exposure to triaryl phosphates: metabolism and biomarkers of exposure

PubMed Central

Furlong, Clement E.

2013-01-01

The leakage of tricresyl phosphate-containing engine lubricants into aircraft cabin air, either from worn or defective engine seals or under normal operating conditions, is a serious concern for both the health and safety of the cabin occupants, since the oil contains one to five percent tricresyl phosphate (TCP) esters, known neurotoxins. The exposure of pilots is a particular concern since their impairment can affect their safe operation of the aircraft. Mass spectrometric (MS)-based protocols for documenting exposures of individuals are described that entail a rapid purification of the TCP-modified plasma enzyme butyrylcholinesterase (BChE). Following protease digestion of BChE, the modified active site peptide is characterized by MS analysis. Approaches for identifying safer engine oil additives are also described. Some general comments regarding the necessity of improving the quality and safety of the cabin air supply are presented. PMID:24285929

Pulmonary function abnormalities in never-smoking flight attendants exposed to secondhand tobacco smoke in the aircraft cabin.

PubMed

Arjomandi, Mehrdad; Haight, Thaddeus; Redberg, Rita; Gold, Warren M

2009-06-01

To determine whether the flight attendants who were exposed to secondhand tobacco smoke in the aircraft cabin have abnormal pulmonary function. We administered questionnaires and performed pulmonary function testing in 61 never-smoking female flight attendants who worked in active air crews before the smoking ban on commercial aircraft (preban). Although the preban flight attendants had normal FVC, FEV1, and FEV1/FVC ratio, they had significantly decreased flow at mid- and low-lung volumes, curvilinear flow-volume curves, and evidence of air trapping. Furthermore, the flight attendants had significantly decreased diffusing capacity (77.5% +/- 11.2% predicted normal) with 51% having a diffusing capacity below their 95% normal prediction limit. This cohort of healthy never-smoking flight attendants who were exposed to secondhand tobacco smoke in the aircraft cabin showed pulmonary function abnormalities suggestive of airway obstruction and impaired diffusion.

Principal Component Analysis for Enhancement of Infrared Spectra Monitoring

NASA Astrophysics Data System (ADS)

Haney, Ricky Lance

The issue of air quality within the aircraft cabin is receiving increasing attention from both pilot and flight attendant unions. This is due to exposure events caused by poor air quality that in some cases may have contained toxic oil components due to bleed air that flows from outside the aircraft and then through the engines into the aircraft cabin. Significant short and long-term medical issues for aircraft crew have been attributed to exposure. The need for air quality monitoring is especially evident in the fact that currently within an aircraft there are no sensors to monitor the air quality and potentially harmful gas levels (detect-to-warn sensors), much less systems to monitor and purify the air (detect-to-treat sensors) within the aircraft cabin. The specific purpose of this research is to utilize a mathematical technique called principal component analysis (PCA) in conjunction with principal component regression (PCR) and proportionality constant calculations (PCC) to simplify complex, multi-component infrared (IR) spectra data sets into a reduced data set used for determination of the concentrations of the individual components. Use of PCA can significantly simplify data analysis as well as improve the ability to determine concentrations of individual target species in gas mixtures where significant band overlap occurs in the IR spectrum region. Application of this analytical numerical technique to IR spectrum analysis is important in improving performance of commercial sensors that airlines and aircraft manufacturers could potentially use in an aircraft cabin environment for multi-gas component monitoring. The approach of this research is two-fold, consisting of a PCA application to compare simulation and experimental results with the corresponding PCR and PCC to determine quantitatively the component concentrations within a mixture. The experimental data sets consist of both two and three component systems that could potentially be present as air contaminants in an aircraft cabin. In addition, experimental data sets are analyzed for a hydrogen peroxide (H2O2) aqueous solution mixture to determine H2O2 concentrations at various levels that could be produced during use of a vapor phase hydrogen peroxide (VPHP) decontamination system. After the PCA application to two and three component systems, the analysis technique is further expanded to include the monitoring of potential bleed air contaminants from engine oil combustion. Simulation data sets created from database spectra were utilized to predict gas components and concentrations in unknown engine oil samples at high temperatures as well as time-evolved gases from the heating of engine oils.

Numerical Study of Ammonia Leak and Dispersion in the International Space Station

NASA Technical Reports Server (NTRS)

Son, Chang H.

2012-01-01

Release of ammonia into the International Space Station (ISS) cabin atmosphere can occur if the water/ammonia barrier breach of the active thermal control system (ATCS) interface heat exchanger (IFHX) happens. After IFHX breach liquid ammonia is introduced into the water-filled internal thermal control system (ITCS) and then to the cabin environment through a ruptured gas trap. Once the liquid water/ammonia mixture exits ITCS, it instantly vaporizes and mixes with the U.S. Laboratory cabin air that results in rapid deterioration of the cabin conditions. The goal of the study is to assess ammonia propagation in the Station after IFHX breach to plan the operation procedure. A Computational Fluid Dynamics (CFD) model for accurate prediction of airflow and ammonia transport within each of the modules in the ISS cabin was developed. CFD data on ammonia content in the cabin aisle way of the ISS and, in particular, in the Russian On- Orbit Segment during the period of 15 minutes after gas trap rupture are presented for four scenarios of rupture response. Localized effects of ammonia dispersion and risk mitigation are discussed.

Selection of air traffic controllers.

DOT National Transportation Integrated Search

1984-06-01

The most frequently used Federal Aviation Administration published cabin safety information is indexed and cross referenced. This includes Federal Aviation Regulations numbers, Air Carrier Operations Bulletin numbers, Advisory Circular numbers, and O...

Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

PubMed

Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

2016-04-15

This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. Copyright © 2015 Elsevier B.V. All rights reserved.

Automation of closed environments in space for human comfort and safety

NASA Technical Reports Server (NTRS)

1990-01-01

The Environmental Control and Life Support System (ECLSS) for the Space Station Freedom and future colonization of the Moon and Mars presents new challenges for present technologies. Current plans call for a crew of 8 to live in a safe, shirt-sleeve environment for 90 days without ground support. Because of these requirements, all life support systems must be self-sufficient and reliable. The ECLSS is composed of six subsystems. The temperature and humidity control (THC) subsystem maintains the cabin temperature and humidity at a comfortable level. The atmosphere control and supply (ACS) subsystem insures proper cabin pressure and partial pressures of oxygen and nitrogen. To protect the space station from fire damage, the fire detection and suppression (FDS) subsystem provides fire sensing alarms and extinguishers. The waste management (WM) subsystem compacts solid wastes for return to Earth, and collects urine for water recovery. Because it is impractical, if not impossible, to supply the station with enough fresh air and water for the duration of the space station's extended mission, these elements are recycled. The atmosphere revitalization (AR) subsystem removes CO2 and other dangerous contaminants from the air. The water recovery and management (WRM) subsystem collects and filters condensate from the cabin to replenish potable water supplies, and processes urine and other waste waters to replenish hygiene water supplies. These subsystems are not fully automated at this time. Furthermore, the control of these subsystems is not presently integrated; they are largely independent of one another. A fully integrated and automated ECLSS would increase astronauts' productivity and contribute to their safety and comfort. The Kansas State University Advanced Design Team is in the process of researching and designing controls for the automation of the ECLSS for Space Station Freedom and beyond. The approach chosen to solve this problem is to divide the design into three phases. The first phase is to research the ECLSS as a whole system and then concentrate efforts on the automation of a single subsystem. The AR subsystem was chosen for our focus. During the second phase, the system control process will then be applied to the AR subsystem.

Aircraft Instrument, Fire Protection, Warning, Communication, Navigation and Cabin Atmosphere Control System (Course Outline), Aviation Mechanics 3 (Air Frame): 9067.04.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

This document presents an outline for a 135-hour course designed to familiarize the student with manipulative skills and theoretical knowledge concerning aircraft instrument systems like major flight and engine instruments; fire protection and fire fighting systems; warning systems and navigation systems; aircraft cabin control systems, such as…

System and method of providing quick thermal comfort with reduced energy by using directed spot conditioning

DOEpatents

Wang, Mingyu; Kadle, Prasad S.; Ghosh, Debashis; Zima, Mark J.; Wolfe, IV, Edward; Craig, Timothy D

2016-10-04

A heating, ventilation, and air conditioning (HVAC) system and a method of controlling a HVAC system that is configured to provide a perceived comfortable ambient environment to an occupant seated in a vehicle cabin. The system includes a nozzle configured to direct an air stream from the HVAC system to the location of a thermally sensitive portion of the body of the occupant. The system also includes a controller configured to determine an air stream temperature and an air stream flow rate necessary to establish the desired heat supply rate for the sensitive portion and provide a comfortable thermal environment by thermally isolating the occupant from the ambient vehicle cabin temperature. The system may include a sensor to determine the location of the sensitive portion. The nozzle may include a thermoelectric device to heat or cool the air stream.

International Space Station (ISS) Gas Logistics Planning in the Post Shuttle Era

NASA Technical Reports Server (NTRS)

Leonard, Daniel J.; Cook, Anthony J.; Lehman, Daniel A.

2011-01-01

Over its life the International Space Station (ISS) has received gas (nitrogen, oxygen, and air) from various sources. Nitrogen and oxygen are used in the cabin to maintain total pressure and oxygen partial pressures within the cabin. Plumbed nitrogen is also required to support on-board experiments and medical equipment. Additionally, plumbed oxygen is required to support medical equipment as well as emergency masks and most importantly EVA support. Gas are supplied to ISS with various methods and vehicles. Vehicles like the Progress and ATV deliver nitrogen (both as a pure gas and as air) and oxygen via direct releases into the cabin. An additional source of nitrogen and oxygen is via tanks on the ISS Airlock. The Airlock nitrogen and oxygen tanks can deliver to various users via pressurized systems that run throughout the ISS except for the Russian segment. Metabolic oxygen is mainly supplied via cabin release from the Elektron and Oxygen Generator Assembly (OGA), which are water electrolyzers. As a backup system, oxygen candles (Solid Fuel Oxygen Generators-SFOGs) supply oxygen to the cabin as well. In the past, a major source of nitrogen and oxygen has come from the Shuttle via both direct delivery to the cabin as well as to recharge the ISS Airlock tanks. To replace the Shuttle capability to recharge the ISS Airlock tanks, a new system was developed called Nitrogen/Oxygen Recharge System (NORS). NIORS consists of high pressure (7000 psi) tanks which recharge the ISS Airlock tanks via a blowdown fill for both nitrogen and oxygen. NORS tanks can be brought up on most logistics vehicles such as the HTV, COTS, and ATV. A proper balance must be maintained to insure sufficient gas resources are available on-orbit so that all users have the required gases via the proper delivery method (cabin and/or plumbed).

Evaluation of Volatile Organic Compounds and Carbonyl Compounds Present in the Cabins of Newly Produced, Medium- and Large-Size Coaches in China

PubMed Central

Lu, Yan-Yang; Lin, Yi; Zhang, Han; Ding, Dongxiao; Sun, Xia; Huang, Qiansheng; Lin, Lifeng; Chen, Ya-Jie; Chi, Yu-Lang; Dong, Sijun

2016-01-01

An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs) and carbonyl compounds (CCs) in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, and isovaleraldehyde were relatively abundant in the cabins. Time was found to affect the emissions of the contaminants in the coaches. Except for benzaldehyde, valeraldehyde and benzene, the highest in-vehicle concentrations of VOCs and CCs were observed on the 15th day after coming off the assembly line, and the concentrations exhibited an approximately inverted U-shaped pattern as a function of time. Interestingly, this study also showed that the interior temperature of the coaches significantly affected the VOCs emissions from the interior materials, whereas the levels of CCs were mainly influenced by the relative humidity within the coaches. In China, guidelines and regulations for the in-vehicle air quality assessment of the coaches have not yet been issued. The results of this study provide further understanding of the in-vehicle air quality of air-conditioned coaches and can be used in the development of both specific and general rules regarding medium- and large-size coaches. PMID:27314375

Cabin Safety Subject Index,

DTIC Science & Technology

1984-01-01

1949 CABIN SAFETY SUBJECT XNDEX(U) FEDERAL AVIATION /~D-AiS 4e9 ADMINISTRATION WASHINGTON DC OFFICE OF RYIRTION MEDICINE D N POLLARD ET AL. JAN 84...City, Oklahoma 73125 13. Type of Report and Period Covered 12. Sponsoring Agency Name and AddressOffice of Aviation Medicine & Office of Flight...Regulations numbers, Air Carrier Operations Bulletin numbers, Advisory Circular numbers, and Office of Aviation Medicine report numbers. U

14 CFR 382.67 - What is the requirement for priority space in the cabin to store passengers' wheelchairs?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false What is the requirement for priority space in the cabin to store passengers' wheelchairs? 382.67 Section 382.67 Aeronautics and Space OFFICE OF... NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Accessibility of Aircraft § 382.67 What is the...

14 CFR 382.67 - What is the requirement for priority space in the cabin to store passengers' wheelchairs?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false What is the requirement for priority space in the cabin to store passengers' wheelchairs? 382.67 Section 382.67 Aeronautics and Space OFFICE OF... NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Accessibility of Aircraft § 382.67 What is the...

14 CFR 382.67 - What is the requirement for priority space in the cabin to store passengers' wheelchairs?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false What is the requirement for priority space in the cabin to store passengers' wheelchairs? 382.67 Section 382.67 Aeronautics and Space OFFICE OF... NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Accessibility of Aircraft § 382.67 What is the...

14 CFR 382.67 - What is the requirement for priority space in the cabin to store passengers' wheelchairs?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false What is the requirement for priority space in the cabin to store passengers' wheelchairs? 382.67 Section 382.67 Aeronautics and Space OFFICE OF... NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Accessibility of Aircraft § 382.67 What is the...

14 CFR 382.67 - What is the requirement for priority space in the cabin to store passengers' wheelchairs?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false What is the requirement for priority space in the cabin to store passengers' wheelchairs? 382.67 Section 382.67 Aeronautics and Space OFFICE OF... NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Accessibility of Aircraft § 382.67 What is the...

Filter Efficiency and Leak Testing of Returned ISS Bacterial Filter Elements After 2.5 Years of Continuous Operation

NASA Technical Reports Server (NTRS)

Green, Robert D.; Agui, Juan H.; Berger, Gordon M.; Vijayakumar, R.; Perry, Jay L.

2016-01-01

The atmosphere revitalization equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provides the vital functions of maintaining a habitable environment for the crew as well as protecting the hardware from fouling by suspended particulate matter. Providing these functions are challenging in pressurized spacecraft cabins because no outside air ventilation is possible and a larger particulate load is imposed on the filtration system due to lack of sedimentation in reduced gravity conditions. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Adsorption (HEPA) filters deployed at multiple locations in each module. These filters are referred to as Bacteria Filter Elements (BFEs). As more experience has been gained with ISS operations, the BFE service life, which was initially one year, has been extended to two to five years, dependent on the location in the U.S. Segment. In previous work we developed a test facility and test protocol for leak testing the ISS BFEs. For this work, we present results of leak testing a sample set of returned BFEs with a service life of 2.5 years, along with particulate removal efficiency and pressure drop measurements. The results can potentially be utilized by the ISS Program to ascertain whether the present replacement interval can be maintained or extended to balance the on-ground filter inventory with extension of the lifetime of ISS to 2024. These results can also provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

A Comprehensive Assessment of Biologicals Contained Within Commercial Airliner Cabin Air

NASA Technical Reports Server (NTRS)

LaDuc, Myron T.; Osman, Shariff; Dekas, Anne; Stuecker, Tara; Newcombe, Dave; Piceno, Yvette; Fuhrman, J.; Andersen, Gary; Venkateswaran, Kasthuri; Bearman, Greg

2006-01-01

Both culture-based and culture-independent, biomarker-targeted microbial enumeration and identification technologies were employed to estimate total microbial and viral burden and diversity within the cabin air of commercial airliners. Samples from each of twenty flights spanning three commercial carriers were collected via air-impingement. When the total viable microbial population was estimated by assaying relative concentrations of the universal energy carrier ATP, values ranged from below detection limits (BDL) to 4.1 x 106 cells/cubic m of air. The total viable microbial population was extremely low in both of Airline A (approximately 10% samples) and C (approximately 18% samples) compared to the samples collected aboard flights on Airline A and B (approximately 70% samples). When samples were collected as a function of time over the course of flights, a gradual accumulation of microbes was observed from the time of passenger boarding through mid-flight, followed by a sharp decline in microbial abundance and viability from the initiation of descent through landing. It is concluded in this study that only 10% of the viable microbes of the cabin air were cultivable and suggested a need to employ state-of-the art molecular assay that measures both cultivable and viable-but-non-cultivable microbes. Among the cultivable bacteria, colonies of Acinetobacter sp. were by far the most profuse in Phase I, and Gram-positive bacteria of the genera Staphylococcus and Bacillus were the most abundant during Phase II. The isolation of the human pathogens Acinetobacter johnsonii, A. calcoaceticus, Janibacter melonis, Microbacterium trichotecenolyticum, Massilia timonae, Staphylococcus saprophyticus, Corynebacterium lipophiloflavum is concerning, as these bacteria can cause meningitis, septicemia, and a handful of sometimes fatal diseases and infections. Molecular microbial community analyses exhibited presence of the alpha-, beta-, gamma-, and delta- proteobacteria, as well as Gram-positive bacteria, Fusobacteria, Cyanobacteria, Deinococci, Bacterioidetes, Spirochetes, and Planctomyces in varying abundance. Neisseria meningitidis rDNA sequences were retrieved in great abundance from Airline A followed by Streptococcus oralis/mitis sequences. Pseudomonas synxantha sequences dominated Airline B clone libraries, followed by those of N. meningitidis and S. oralis/mitis. In Phase II, Airline C, sequences representative of more than 113 species, enveloping 12 classes of bacteria, were retrieved. Proteobacterial sequences were retrieved in greatest frequency (58% of all clone sequences), followed in short order by those stemming from Gram-positives bacteria (31% of all clone sequences). As for overall phylogenetic breadth, Gram-positive and alpha-proteobacteria seem to have a higher affinity for international flights, whereas beta-and gamma-proteobacteria are far more common about domestic cabin air parcels in Airline C samples. Ultimately, the majority of microbial species circulating throughout the cabin airs of commercial airliners are commensal, infrequently pathogenic normal flora of the human nasopharynx and respiratory system. Many of these microbes likely originate from the oral and nasal cavities, and lungs of passengers and flight crew and are disseminated unknowingly via routine conversation, coughing, sneezing, and stochastic passing of fomites. The data documented in this study will be useful to generate a baseline microbial population database and can be utilized to develop biosensor instrumentation for monitoring microbial quality of cabin or urban air.

Dichlorvos vapour disinsection of aircraft

PubMed Central

Jensen, Jens A.; Flury, Vincent P.; Schoof, Herbert F.

1965-01-01

The authors describe the testing of an automatic aircraft disinsection system permanently installed on a commercial DC-6B passenger aircraft. An air-compressor forces ambient cabin air, partially saturated with dichlorvos vapour at a set concentration, through the cabin, cockpit and baggage compartments of the aircraft for 30 minutes. Insecticide concentrations and insect mortality were observed in post-overhaul check flights, and insect mortality and passenger reactions were observed on scheduled flights between Miami, Florida, and Nassau, Bahamas. The results showed satisfactory biological efficiency. The passengers were unaware of the disinsection process and showed no signs of discomfort. ImagesFIG. 1FIG. 2FIG. 3 PMID:14310904

Measurements of major VOCs released into the closed cabin environment of different automobiles under various engine and ventilation scenarios.

PubMed

Kim, Ki-Hyun; Szulejko, Jan E; Jo, Hyo-Jae; Lee, Min-Hee; Kim, Yong-Hyun; Kwon, Eilhann; Ma, Chang-Jin; Kumar, Pawan

2016-08-01

Volatile organic compounds (VOCs) in automobile cabins were measured quantitatively to describe their emission characteristics in relation to various idling scenarios using three used automobiles (compact, intermediate sedan, and large sedan) under three different idling conditions ([1] cold engine off and ventilation off, [2] exterior air ventilation with idling warm engine, and [3] internal air recirculation with idling warm engine). The ambient air outside the vehicle was also analyzed as a reference. A total of 24 VOCs (with six functional groups) were selected as target compounds. Accordingly, the concentration of 24 VOC quantified as key target compounds averaged 4.58 ± 3.62 ppb (range: 0.05 (isobutyl alcohol) ∼ 38.2 ppb (formaldehyde)). Moreover, if their concentrations are compared between different automobile operational modes: the 'idling engine' levels (5.24 ± 4.07) was 1.3-5 times higher than the 'engine off' levels (4.09 ± 3.23) across all 3 automobile classes. In summary, automobile in-cabin VOC emissions are highly contingent on changes in engine and ventilation modes. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Airplane Cabin Microbiome.

PubMed

Weiss, Howard; Hertzberg, Vicki Stover; Dupont, Chris; Espinoza, Josh L; Levy, Shawn; Nelson, Karen; Norris, Sharon

2018-06-06

Serving over three billion passengers annually, air travel serves as a conduit for infectious disease spread, including emerging infections and pandemics. Over two dozen cases of in-flight transmissions have been documented. To understand these risks, a characterization of the airplane cabin microbiome is necessary. Our study team collected 229 environmental samples on ten transcontinental US flights with subsequent 16S rRNA sequencing. We found that bacterial communities were largely derived from human skin and oral commensals, as well as environmental generalist bacteria. We identified clear signatures for air versus touch surface microbiome, but not for individual types of touch surfaces. We also found large flight-to-flight beta diversity variations with no distinguishing signatures of individual flights, rather a high between-flight diversity for all touch surfaces and particularly for air samples. There was no systematic pattern of microbial community change from pre- to post-flight. Our findings are similar to those of other recent studies of the microbiome of built environments. In summary, the airplane cabin microbiome has immense airplane to airplane variability. The vast majority of airplane-associated microbes are human commensals or non-pathogenic, and the results provide a baseline for non-crisis-level airplane microbiome conditions.

Methods for designing treatments to reduce interior noise of predominant sources and paths in a single engine light aircraft

NASA Technical Reports Server (NTRS)

Hayden, Richard E.; Remington, Paul J.; Theobald, Mark A.; Wilby, John F.

1985-01-01

The sources and paths by which noise enters the cabin of a small single engine aircraft were determined through a combination of flight and laboratory tests. The primary sources of noise were found to be airborne noise from the propeller and engine casing, airborne noise from the engine exhaust, structureborne noise from the engine/propeller combination and noise associated with air flow over the fuselage. For the propeller, the primary airborne paths were through the firewall, windshield and roof. For the engine, the most important airborne path was through the firewall. Exhaust noise was found to enter the cabin primarily through the panels in the vicinity of the exhaust outlet although exhaust noise entering the cabin through the firewall is a distinct possibility. A number of noise control techniques were tried, including firewall stiffening to reduce engine and propeller airborne noise, to stage isolators and engine mounting spider stiffening to reduce structure-borne noise, and wheel well covers to reduce air flow noise.

Market Potential Study for Standing Cabin Concept for Domestic Low-Cost Commercial Airlines in Malaysia

NASA Astrophysics Data System (ADS)

Romli, Fairuz I.; Dasuki, Norhafizah; Yazdi Harmin, Mohammad

2016-02-01

An affordable air transportation has become the operational aim of many airlines these days. This is to cater the growing air travel demands from people of different social and economic status. One of the revolutionary proposals to reduce the operational costs, hence the flight ticket price, is by introducing the so-called standing cabin concept. This concept involves transporting passengers during the entire flight in their standing position with a proper support of a vertical seat. As can be expected with many new inventions, despite its clear advantages, the concept has been met with mixed reactions from the public. This study intends to establish whether the standing cabin concept has a market potential to be implemented for domestic flights in Malaysia. The public perception is determined from collected data through a survey done at two major local low-cost airport terminals. It can be concluded from the results that the concept has a good market potential for application on flights with duration of less than two hours.

Environmental control and life support system: Analysis of STS-1

NASA Technical Reports Server (NTRS)

Steines, G.

1980-01-01

The capability of the orbiter environmental control and life support system (ECLSS) to support vehicle cooling requirements in the event of cabin pressure reduction to 9 psia was evaluated, using the Orbiter versions of the shuttle environmental consumbles usage requirement evaluation (SECURE) program, and using heat load input data developed by the spacecraft electrical power simulator (SEPS) program. The SECURE model used in the analysis, the timeline and ECLSS configuration used in formulating the analysis, and the results of the analysis are presented. The conclusion which may be drawn drom these results. is summarized. There are no significant thermal problems with the proposed mission. There are, however, several procedures which could be optimized for better performance: setting the cabin HX air bypass and the interchanger water bypass to the zero flow position is of questionable efficacy; the cabin air pressure monitoring procedure should be re-evaluated; and the degree of equipment power down specified for this analysis and no problems were noted.

Regenerable device for scrubbing breathable air of CO2 and moisture without special heat exchanger equipment

NASA Technical Reports Server (NTRS)

Tepper, E. H. (Inventor)

1977-01-01

The device concerns the circulation of cabin air through canisters which absorb and adsorb carbon dioxide, together with excess moisture, and return the scrubbed air to the cabin for recirculation. A coating on an inert substrate in granular form absorbs and adsorbs the impurities at standard temperatures and pressures, but desorbs such impurities at low pressures (vacuum) and standard temperatures. This fact is exploited by making the device in a stack of cells consisting of layers or cells which are isolated from one another flow-wise and are connected to separate manifolds and valving systems into two separate subsets. A first subset may be connected for the flow breathable air therethrough until the polyethyleneimine of its cells is saturated with CO2 and H2O. During the same period the second subset of cells is manifolded to a vacuum source.

Impact of the electric compressor for automotive air conditioning system on fuel consumption and performance analysis

NASA Astrophysics Data System (ADS)

Zulkifli, A. A.; Dahlan, A. A.; Zulkifli, A. H.; Nasution, H.; Aziz, A. A.; Perang, M. R. M.; Jamil, H. M.; Misseri, M. N.

2015-12-01

Air conditioning system is the biggest auxiliary load in a vehicle where the compressor consumed the largest. Problem with conventional compressor is the cooling capacity cannot be control directly to fulfill the demand of thermal load inside vehicle cabin. This study is conducted experimentally to analyze the difference of fuel usage and air conditioning performance between conventional compressor and electric compressor of the air conditioning system in automobile. The electric compressor is powered by the car battery in non-electric vehicle which the alternator will recharge the battery. The car is setup on a roller dynamometer and the vehicle speed is varied at 0, 30, 60, 90 and 110 km/h at cabin temperature of 25°C and internal heat load of 100 and 400 Watt. The results shows electric compressor has better fuel consumption and coefficient of performance compared to the conventional compressor.

Cabin noise and weight reduction program for the Gulfstream G200

NASA Astrophysics Data System (ADS)

Barton, C. Kearney

2002-11-01

This paper describes the approach and logic involved in a cabin noise and weight reduction program for an existing aircraft that was already in service with a pre-existing insulation package. The aircraft, a Gulfstream G200, was formally an IAI Galaxy, and the program was purchased from IAI in 2001. The approach was to investigate every aspect of the aircraft that could be a factor for cabin noise. This included such items as engine mounting and balancing criteria, the hydraulic system, the pressurization and air-conditioning system, the outflow valve, the interior shell and mounting system, antennae and other hull protuberances, as well as the insulation package. Each of these items was evaluated as potential candidates for noise and weight control modifications. Although the program is still ongoing, the results to date include a 175-lb weight savings and a 5-dB reduction in the cabin average Speech Interference Level (SIL).

14 CFR 252.17 - Enforcement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.17 Enforcement. Air carriers and foreign air carriers shall take such action as is necessary to ensure that smoking by passengers or crew is not permitted in the passenger cabin or lavatories on no-smoking flight segments. Air carriers shall take such action as is...

14 CFR 252.17 - Enforcement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.17 Enforcement. Air carriers and foreign air carriers shall take such action as is necessary to ensure that smoking by passengers or crew is not permitted in the passenger cabin or lavatories on no-smoking flight segments. Air carriers shall take such action as is...

14 CFR 252.17 - Enforcement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.17 Enforcement. Air carriers and foreign air carriers shall take such action as is necessary to ensure that smoking by passengers or crew is not permitted in the passenger cabin or lavatories on no-smoking flight segments. Air carriers shall take such action as is...

14 CFR 252.17 - Enforcement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.17 Enforcement. Air carriers and foreign air carriers shall take such action as is necessary to ensure that smoking by passengers or crew is not permitted in the passenger cabin or lavatories on no-smoking flight segments. Air carriers shall take such action as is...

14 CFR 252.17 - Enforcement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.17 Enforcement. Air carriers and foreign air carriers shall take such action as is necessary to ensure that smoking by passengers or crew is not permitted in the passenger cabin or lavatories on no-smoking flight segments. Air carriers shall take such action as is...

Aviation occupant survival factors: an empirical study of the SQ006 accident.

PubMed

Chang, Yu-Hern; Yang, Hui-Hua

2010-03-01

We present an empirical study of Singapore Airline (SIA) flight SQ006 to illustrate the critical factors that influence airplane occupant survivability. The Fuzzy Delphi Method was used to identify and rank the survival factors that may reduce injury and fatality in potentially survivable accidents. This is the first attempt by a group from both the public and private sectors in Taiwan to focus on cabin-safety issues related to survival factors. We designed a comprehensive survey based on our discussions with aviation safety experts. We next designed an array of important cabin-safety dimensions and then investigated and selected the critical survival factors for each dimension. Our findings reveal important cabin safety and survivability information that should provide a valuable reference for developing and evaluating aviation safety programs. We also believe that the results will be practical for designing cabin-safety education material for air travelers. Finally, the major contribution of this research is that it has identified 47 critical factors that influence accident survivability; therefore, it may encourage improvements that will promote more successful cabin-safety management. Copyright 2009 Elsevier Ltd. All rights reserved.

International Space Station USOS Crew Quarters Ventilation and Acoustic Design Implementation

NASA Technical Reports Server (NTRS)

Broyan, James Lee, Jr.

2009-01-01

The International Space Station (ISS) United States Operational Segment (USOS) has four permanent rack sized ISS Crew Quarters (CQ) providing a private crewmember space. The CQ uses Node 2 cabin air for ventilation/thermal cooling, as opposed to conditioned ducted air from the ISS Temperature Humidity Control System or the ISS fluid cooling loop connections. Consequently, CQ can only increase the air flow rate to reduce the temperature delta between the cabin and the CQ interior. However, increasing airflow causes increased acoustic noise so efficient airflow distribution is an important design parameter. The CQ utilized a two fan push-pull configuration to ensure fresh air at the crewmember s head position and reduce acoustic exposure. The CQ interior needs to be below Noise Curve 40 (NC-40). The CQ ventilation ducts are open to the significantly louder Node 2 cabin aisle way which required significantly acoustic mitigation controls. The design implementation of the CQ ventilation system and acoustic mitigation are very inter-related and require consideration of crew comfort balanced with use of interior habitable volume, accommodation of fan failures, and possible crew uses that impact ventilation and acoustic performance. This paper illustrates the types of model analysis, assumptions, vehicle interactions, and trade-offs required for CQ ventilation and acoustics. Additionally, on-orbit ventilation system performance and initial crew feedback is presented. This approach is applicable to any private enclosed space that the crew will occupy.

Comparison of inflight first aid performed by cabin crew members and medical volunteers.

PubMed

Kim, Jung Ha; Choi-Kwon, Smi; Park, Young Hwan

2017-03-01

Since the number of air travellers, including the elderly and passengers with an underlying disease, is increasing every year, the number of inflight emergency patients is expected to increase as well. We attempted to identify the incidence and types of reported inflight medical incidents and analyse the first aid performed by cabin crew members or medical volunteers in flights by an Asian airline. We also investigated the cases of inflight deaths and aircraft diversions. We reviewed the cabin reports and medical records submitted by cabin crew members and inflight medical volunteers from 2009 to 2013. We found that inflight medical incidents increased annually, with a total of 2818 cases reported. Fifteen cases of inflight deaths and 15 cases of aircraft diversions during this period were also reported. First aid was performed by the cabin crew alone in 52% of the cases and by medical volunteers in 47.8% of the cases. The most commonly reported causes for first aid performed by the cabin crew and medical volunteers were burns and syncope, respectively. : Since burns were one of the common reasons that first aid was provided by the cabin crew, it may be necessary to include first aid treatments for burns in the annual re-qualification training programme. Furthermore, the assessment of unconsciousness and potentially critical respiratory symptoms is very important for cabin crew members because those conditions can lead to inflight deaths and aircraft diversion. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

USAF bioenvironmental noise data handbook. Volume 168: MB-3 tester, pressurized cabin leakage, aircraft

NASA Astrophysics Data System (ADS)

Rau, T. H.

1982-06-01

The MB-3 Tester is an electric motor-driven cabin leakage tester designed to furnish pressurized air to the aircraft at controlled pressures and temperatures during ground pressurization of aircraft cockpits and pressurized compartments. This report provides measured data defining the bioacoustic environments produced by this unit operating at a normal rated/load condition. Near-field data are reported for 37 locations in a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference level, perceived noise level, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors.

Isopropyl Alcohol Volatile Sensor Development for In-Flight Air Quality

DTIC Science & Technology

Breathing air quality within commercial airline cabins has come under increased scrutiny due to the identification of volatile organic compounds from...cleaning solvents for breathing lines and life support gear used in the aerospace community , as a target analyte.

Evaluation of the ride quality of a light twin engine airplane using a ride quality meter

NASA Technical Reports Server (NTRS)

Stewart, Eric C.

1989-01-01

A ride quality meter was used to establish the baseline ride quality of a light twin-engine airplane planned for use as a test bed for an experimental gust alleviation system. The ride quality meter provides estimates of passenger ride discomfort as a function of cabin noise and vibration (acceleration) in five axes (yaw axis omitted). According to the ride quality meter, in smooth air the cabin noise was the dominant source of passenger discomfort, but the total discomfort was approximately the same as that for the smooth-air condition. The researcher's subjective opinion, however, is that the total ride discomfort was much worse in the moderate turbulence than it was in the smooth air. The discrepancy is explained by the lack of measurement of the low-frequency accelerations by the ride quality meter.

The Flying Newsboy: A Small Daily Attempts Air Delivery.

ERIC Educational Resources Information Center

Watts, Elizabeth A.

For 10 months in 1929-30, subscribers to "The McCook (Nebraska) Daily Gazette" (a daily newspaper serving 33 towns in southwestern Nebraska and northwestern Kansas) received their newspapers via air delivery with "The Newsboy," a Curtis Robin cabin monoplane. In an age when over-the-road travel was difficult and air travel was…

INDOOR AIR PURIFICATION VIA LOW-ENERGY, IN-SITU REGENERATED SILICA-TITANIA COMPOSITES - PHASE I

EPA Science Inventory

“Sick building syndrome,” used to describe acute negative health effects linked to time spent in a building, has been related to poor indoor air quality.  Similarly, poor aircraft cabin air quality has been identified as a cause of negative health effects on pilots and fli...

Space station common module thermal management: Design and construction of a test bed

NASA Technical Reports Server (NTRS)

Barile, R. G.

1986-01-01

In this project, a thermal test bed was designed, simulated, and planned for construction. The thermal system features interior and exterior thermal loads and interfacing with the central-radiator thermal bus. Components of the test bed include body mounted radiator loop with interface heat exchangers (600 Btu/hr); an internal loop with cabin air-conditioning and cold plates (3400 Btu/hr); interface heat exchangers to the central bus (13,000 Btu/hr); and provisions for new technology including advanced radiators, thermal storage, and refrigeration. The apparatus will be mounted in a chamber, heated with lamps, and tested in a vacuum chamber with LN2-cooled walls. Simulation of the test bed was accomplished using a DEC PRO 350 computer and the software package TK! olver. Key input variables were absorbed solar radiation and cold plate loads. The results indicate temperatures on the two loops will be nominal when the radiation and cold plate loads are in the range of 25% to 75% of peak loads. If all loads fall to zero, except the cabin air system which was fixed, the radiator fluid will drop below -100 F and may cause excessive pressure drop. If all loads reach 100%, the cabin air temperature could rise to 96 F.

Evaluation of a liquid cooling garment as a component of the Launch and Entry Suit (LES)

NASA Technical Reports Server (NTRS)

Waligora, J.; Charles, J.; Fritsch, I.; Fortney, S.; Siconolfi, S.; Pepper, L.; Bagian, L.; Kumar, V.

1994-01-01

The LES is a partial pressure suit and a component of the shuttle life support system used during launch and reentry. The LES relies on gas ventilation with cabin air to provide cooling. There are conditions during nominal launch and reentry, landing, and post-landing phases when cabin temperature is elevated. Under these conditions, gas cooling may result in some discomfort and some decrement in orthostatic tolerance. There are emergency conditions involving loss of cabin ECS capability that would challenge crew thermal tolerance. The results of a series of tests are presented. These tests were conducted to assess the effectiveness of a liquid-cooled garment in alleviating thermal discomfort, orthostatic intolerance, and thermal intolerance during simulated mission phases.

Effects of Cabin Upsets on Adsorption Columns for Air Revitalization

NASA Technical Reports Server (NTRS)

LeVan, Douglas

1999-01-01

The National Aeronautics and Space Administration (NASA) utilizes adsorption technology as part of contaminant removal systems designed for long term missions. A variety of trace contaminants can be effectively removed from gas streams by adsorption onto activated carbon. An activated carbon adsorption column meets NASA's requirements of a lightweight and efficient means of controlling trace contaminant levels aboard spacecraft and space stations. The activated carbon bed is part of the Trace Contaminant Control System (TCCS) which is utilized to purify the cabin atmosphere. TCCS designs oversize the adsorption columns to account for irregular fluctuations in cabin atmospheric conditions. Variations in the cabin atmosphere include changes in contaminant concentrations, temperature, and relative humidity. Excessively large deviations from typical conditions can result from unusual crew activity, equipment malfunctions, or even fires. The research carried out under this award focussed in detail on the effects of cabin upsets on the performance of activated carbon adsorption columns. Both experiments and modeling were performed with an emphasis on the roll of a change in relative humidity on adsorption of trace contaminants. A flow through fixed-bed apparatus was constructed at the NASA Ames Research Center, and experiments were performed there. Modeling work was performed at the University of Virginia.

Passenger safety, health, and comfort: a review.

PubMed

Rayman, R B

1997-05-01

Since the birth of aviation medicine approximately 80 yrs ago, practitioners and scientists have given their attention primarily to flight deck crew, cabin crew, and ground support personnel. However, in more recent years we have broadened our horizons to include the safety, health, and comfort of passengers flying commercial aircraft. This will be even more compelling as more passengers take to the air in larger aircraft and flying longer hours to more distant destinations. Further, we can expect to see more older passengers because people in many countries are living longer, healthier lives. The author first discusses the stresses imposed by ordinary commercial flight upon travelers such as airport tumult, barometric pressure changes, immobility, jet lag, noise/ vibration, and radiation. Medical considerations are next addressed describing inflight illness and medical care capability aboard U.S. air carriers. Passenger safety, cabin air quality, and the preventive medicine aspects of air travel are next reviewed in the context of passenger safety, health, and comfort. Recommendations are addressed to regulator agencies, airlines aircraft manufacturers, and the aerospace medicine community.

Development of a Next-Generation Membrane-Integrated Adsorption Processor for CO2 Removal and Compression for Closed-Loop Air Revitalization Systems

NASA Technical Reports Server (NTRS)

Mulloth, Lila; LeVan, Douglas

2002-01-01

The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane integrated, adsorption processor for CO2 removal nd compression in closed-loop air revitalization systems. This processor will use many times less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of gas dryer, CO2 separator, and CO2 compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

Indoor to outdoor air quality associations with self-pollution implications inside passenger car cabins

NASA Astrophysics Data System (ADS)

Abi-Esber, L.; El-Fadel, M.

2013-12-01

In this study, in-vehicle and out-vehicle concentrations of fine particulate matter (PM2.5) and carbon monoxide (CO) are measured to assess commuter's exposure in a commercial residential area and on a highway, under three popular ventilation modes namely, one window half opened, air conditioning on fresh air intake, and air conditioning on recirculation and examine its relationship to scarcely studied parameters including self pollution, out-vehicle sample intake location and meteorological gradients. Self pollution is the intrusion of a vehicle's own engine fumes into the passenger's compartment. For this purpose, six car makes with different ages were instrumented to concomitantly monitor in- and out-vehicle PM2.5 and CO concentrations as well as meteorological parameters. Air pollution levels were unexpectedly higher in new cars compared to old cars, with in-cabin air quality most correlated to that of out-vehicle air near the front windshield. Self-pollution was observed at variable rates in three of the six tested cars. Significant correlations were identified between indoor to outdoor pressure difference and PM2.5 and CO In/Out (IO) ratios under air recirculation and window half opened ventilation modes whereas temperature and humidity difference affected CO IO ratios only under the air recirculation ventilation mode.

CCAA cycling

NASA Image and Video Library

2014-06-04

ISS040-E-007122 (4 June 2014) --- NASA astronaut Reid Wiseman, Expedition 40 flight engineer, works with the Common Cabin Air Assembly (CCAA) in the Destiny laboratory of the International Space Station.

CCAA cycling

NASA Image and Video Library

2014-06-04

ISS040-E-007123 (4 June 2014) --- NASA astronaut Reid Wiseman, Expedition 40 flight engineer, works with the Common Cabin Air Assembly (CCAA) in the Destiny laboratory of the International Space Station.

In-flight monitoring of particle deposition in the environmental control systems of commercial airliners in China

NASA Astrophysics Data System (ADS)

Cao, Qing; Xu, Qiuyu; Liu, Wei; Lin, Chao-Hsin; Wei, Daniel; Baughcum, Steven; Norris, Sharon; Chen, Qingyan

2017-04-01

Severe air pollution and low on-time performance of commercial flights in China could increase particle deposition in the environmental control systems (ECSs) of commercial airliners. The particles deposited in the ECSs could negatively affect the performance of the airplanes. In addition, particles that penetrate into the aircraft cabin could adversely impact the health of passengers and crew members. This investigation conducted simultaneous measurements of particle mass concentration and size distribution inside and outside the cabin during 64 commercial flights of Boeing 737 and Airbus 320 aircraft departing from or arriving at Tianjin Airport in China. The results showed that the PM2.5 mass concentration deposition in the ECSs of these airplanes ranged from 50% to 90%, which was much higher than that measured in an airplane with a ground air-conditioning unit. The average deposition rates of particles with diameters of 0.5-1 μm, 1-2 μm, 2-5 μm, 5-10 μm, and >10 μm were 89 ± 8%, 85 ± 13%, 80 ± 13%, 73 ± 15%, and 80 ± 14%, respectively. The in-flight measurement results indicated that the particle concentration in the breathing zone was higher than that in the air-supply zone, which implies a significant contribution by particles in the interior of the cabin. Such particles come from human emissions or particle resuspension from interior surfaces.

The influence of a low air pressure environment on human metabolic rate during short-term (< 2 h) exposures.

PubMed

Cui, W; Wang, H; Wu, T; Ouyang, Q; Hu, S; Zhu, Y

2017-03-01

Passengers in aircraft cabins are exposed to low-pressure environments. One of the missing links in the research on thermal comfort under cabin conditions is the influence of low air pressure on the metabolic rate. In this research, we simulated the cabin pressure regime in a chamber in which the pressure level could be controlled. Three pressure levels (101/85/70 kPa) were tested to investigate how metabolic rate changed at different pressure levels. The results show that as pressure decreased, the respiratory flow rate (RFR) at standard condition (STPD: 0°C, 101 kPa) significantly decreased. Yet the oxygen (O 2 ) consumption and carbon dioxide (CO 2 ) production significantly increased, as reflected in the larger concentration difference between inhaled and exhaled air. A significant increase in the respiratory quotient (RQ) was also observed. For metabolic rate, no significant increase (P > 0.05) was detected when pressure decreased from 101 kPa to 85 kPa; however, the increase associated with a pressure decrease from 85 kPa to 70kPa was significant (P < 0.05). Empirical equations describing the above parameters are provided, which can be helpful for thermal comfort assessment in short-haul flights. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterisation of nanoparticle emissions and exposure at traffic intersections through fast-response mobile and sequential measurements

NASA Astrophysics Data System (ADS)

Goel, Anju; Kumar, Prashant

2015-04-01

Quantification of disproportionate contribution made by signalised traffic intersections (TIs) to overall daily commuting exposure is important but barely known. We carried out mobile measurements in a car for size-resolved particle number concentrations (PNCs) in the 5-560 nm range under five different ventilation settings on a 6 km long busy round route with 10 TIs. These ventilation settings were windows fully open and both outdoor air intake from fan and heating off (Set1), windows closed, fan 25% on and heating 50% on (Set2), windows closed, fan 100% on and heating off (Set3), windows closed, fan off and heating 100% on (Set4), and windows closed, fan and heating off (Set5). Measurements were taken sequentially inside and outside the car cabin at 10 Hz sampling rate using a solenoid switching system in conjunction with a fast response differential mobility spectrometer (DMS50). The objectives were to: (i) identify traffic conditions under which TIs becomes hot-spots of PNCs, (ii) assess the effect of ventilation settings in free-flow and delay conditions (waiting time at a TI when traffic signal is red) on in-cabin PNCs with respect to on-road PNCs at TIs, (iii) deriving the relationship between the PNCs and change in driving speed during delay time at the TIs, and (iv) quantify the contribution of exposure at TIs with respect to overall commuting exposure. Congested TIs were found to become hot-spots when vehicle accelerate from idling conditions. In-cabin peak PNCs followed similar temporal trend as for on-road peak PNCs. Reduction in in-cabin PNC with respect to outside PNC was highest (70%) during free-flow traffic conditions when both fan drawing outdoor air into the cabin and heating was switched off. Such a reduction in in-cabin PNCs at TIs was highest (88%) with respect to outside PNC during delay conditions when fan was drawing outside air at 25% on and heating was 50% on settings. PNCs and change in driving speed showed an exponential-fit relationship during the delay events at TIs. Short-term exposure for ∼2% of total commuting time in car corresponded to ∼25% of total respiratory doses. This study highlights a need for more studies covering diverse traffic and geographical conditions in urban environments so that the disparate contribution of exposure at TIs can be quantified.

Vortex dynamics and scalar transport in the wake of a bluff body driven through a steady recirculating flow

NASA Astrophysics Data System (ADS)

Poussou, Stephane B.; Plesniak, Michael W.

2012-09-01

The air ventilation system in wide-body aircraft cabins provides passengers with a healthy breathing environment. In recent years, the increase in global air traffic has amplified contamination risks by airborne flu-like diseases and terrorist threats involving the onboard release of noxious materials. In particular, passengers moving through a ventilated cabin may transport infectious pathogens in their wake. This paper presents an experimental investigation of the wake produced by a bluff body driven through a steady recirculating flow. Data were obtained in a water facility using particle image velocimetry and planar laser induced fluorescence. Ventilation attenuated the downward convection of counter-rotating vortices produced near the free-end corners of the body and decoupled the downwash mechanism from forward entrainment, creating stagnant contaminant regions.

ISS Ambient Air Quality: Updated Inventory of Known Aerosol Sources

NASA Technical Reports Server (NTRS)

Meyer, Marit

2014-01-01

Spacecraft cabin air quality is of fundamental importance to crew health, with concerns encompassing both gaseous contaminants and particulate matter. Little opportunity exists for direct measurement of aerosol concentrations on the International Space Station (ISS), however, an aerosol source model was developed for the purpose of filtration and ventilation systems design. This model has successfully been applied, however, since the initial effort, an increase in the number of crewmembers from 3 to 6 and new processes on board the ISS necessitate an updated aerosol inventory to accurately reflect the current ambient aerosol conditions. Results from recent analyses of dust samples from ISS, combined with a literature review provide new predicted aerosol emission rates in terms of size-segregated mass and number concentration. Some new aerosol sources have been considered and added to the existing array of materials. The goal of this work is to provide updated filtration model inputs which can verify that the current ISS filtration system is adequate and filter lifetime targets are met. This inventory of aerosol sources is applicable to other spacecraft, and becomes more important as NASA considers future long term exploration missions, which will preclude the opportunity for resupply of filtration products.

Effects of whole-body cryotherapy duration on thermal and cardio-vascular response.

PubMed

Fonda, Borut; De Nardi, Massimo; Sarabon, Nejc

2014-05-01

Whole-body cryotherapy (WBC) is the exposure of minimally dressed participants to very cold air, either in a specially designed chamber (cryo-chamber) or cabin (cryo-cabin), for a short period of time. Practitioners are vague when it comes to recommendations on the duration of a single session. Recommended exposure for cryo-chamber is 150s, but no empirically based recommendations are available for a cryo-cabin. Therefore the aim of this study was to examine thermal and cardio-vascular responses after 90, 120, 150 and 180s of WBC in a cryo-cabin. Our hypothesis was that skin temperature would be significantly lower after longer exposers. Twelve male participants (age 23.9±4.2 years) completed four WBC of different durations (90, 120, 150 and 180s) in a cryo-cabin. Thermal response, heart rate and blood pressure were measured prior, immediately after, 5min after and 30min after the session. Skin temperature differed significantly among different durations, except between 150 and 180s. There was no significant difference in heart rate and blood pressure. Thermal discomfort during a single session displayed a linear increase throughout the whole session. Our results indicate that practitioners and clinicians using cryo-cabin for WBC do not need to perform sessions longer than 150s. We have shown that longer sessions do not substantially affect thermal and cardio-vascular response, but do increase thermal discomfort. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigating ozone-induced decomposition of surface-bound permethrin for conditions in aircraft cabins.

PubMed

Coleman, B K; Wells, J R; Nazaroff, W W

2010-02-01

The reaction of ozone with permethrin can potentially form phosgene. Published evidence on ozone levels and permethrin surface concentrations in aircraft cabins indicated that significant phosgene formation might occur in this setting. A derivatization technique was developed to detect phosgene with a lower limit of detection of 2 ppb. Chamber experiments were conducted with permethrin-coated materials (glass, carpet, seat fabric, and plastic) exposed to ozone under cabin-relevant conditions (150 ppb O(3), 4.5/h air exchange rate, <1% relative humidity, 1700 ng/cm(2) of permethrin). Phosgene was not detected in these experiments. Reaction of ozone with permethrin appears to be hindered by the electron-withdrawing chlorine atoms adjacent to the double bond in permethrin. Experimental results indicate that the upper limit on the reaction probability of ozone with surface-bound permethrin is approximately 10(-7). Extrapolation by means of material-balance modeling indicates that the upper limit on the phosgene level in aircraft cabins resulting from this chemistry is approximately 1 microg/m(3) or approximately 0.3 ppb. It was thus determined that phosgene formation, if it occurs in aircraft cabins, is not likely to exceed relevant, health-based phosgene exposure guidelines. Phosgene formation from ozone-initiated oxidation of permethrin in the aircraft cabin environment, if it occurs, is estimated to generate levels below the California Office of Environmental Health Hazard Assessment acute reference exposure level of 4 microg/m(3) or approximately 1 ppb.

Integrated thermal and energy management of plug-in hybrid electric vehicles

NASA Astrophysics Data System (ADS)

Shams-Zahraei, Mojtaba; Kouzani, Abbas Z.; Kutter, Steffen; Bäker, Bernard

2012-10-01

In plug-in hybrid electric vehicles (PHEVs), the engine temperature declines due to reduced engine load and extended engine off period. It is proven that the engine efficiency and emissions depend on the engine temperature. Also, temperature influences the vehicle air-conditioner and the cabin heater loads. Particularly, while the engine is cold, the power demand of the cabin heater needs to be provided by the batteries instead of the waste heat of engine coolant. The existing energy management strategies (EMS) of PHEVs focus on the improvement of fuel efficiency based on hot engine characteristics neglecting the effect of temperature on the engine performance and the vehicle power demand. This paper presents a new EMS incorporating an engine thermal management method which derives the global optimal battery charge depletion trajectories. A dynamic programming-based algorithm is developed to enforce the charge depletion boundaries, while optimizing a fuel consumption cost function by controlling the engine power. The optimal control problem formulates the cost function based on two state variables: battery charge and engine internal temperature. Simulation results demonstrate that temperature and the cabin heater/air-conditioner power demand can significantly influence the optimal solution for the EMS, and accordingly fuel efficiency and emissions of PHEVs.

Study of noise transmission through double wall aircraft windows

NASA Technical Reports Server (NTRS)

Vaicaitis, R.

1983-01-01

Analytical and experimental procedures were used to predict the noise transmitted through double wall windows into the cabin of a twin-engine G/A aircraft. The analytical model was applied to optimize cabin noise through parametric variation of the structural and acoustic parameters. The parametric study includes mass addition, increase in plexiglass thickness, decrease in window size, increase in window cavity depth, depressurization of the space between the two window plates, replacement of the air cavity with a transparent viscoelastic material, change in stiffness of the plexiglass material, and different absorptive materials for the interior walls of the cabin. It was found that increasing the exterior plexiglass thickness and/or decreasing the total window size could achieve the proper amount of noise reduction for this aircraft. The total added weight to the aircraft is then about 25 lbs.

Hydrophobic, Porous Battery Boxes

NASA Technical Reports Server (NTRS)

Bragg, Bobby J.; Casey, John E., Jr.

1995-01-01

Boxes made of porous, hydrophobic polymers developed to contain aqueous potassium hydroxide electrolyte solutions of zinc/air batteries while allowing air to diffuse in as needed for operation. Used on other types of batteries for in-cabin use in which electrolytes aqueous and from which gases generated during operation must be vented without allowing electrolytes to leak out.

Flying and Your Child's Ears

MedlinePlus

... cry during those last few minutes of the flight, when the air pressure in the cabin increases ... of decaffeinated fluids (water is best) throughout the flight. Drinking a lot is very important, not only ...

International Space Station Common Cabin Air Assembly Water Separator On-Orbit Operation, Failure, and Redesign

NASA Technical Reports Server (NTRS)

Balistreri, Steven F., Jr.; Shaw, Laura A.; Laliberte, Yvon

2010-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The Water Separator (WS) pulls in air and water from the CHX, and centrifugally separates the mixture, sending the water to the condensate bus and the air back into the CHX outlet airstream. Two distinct early failures of the CCAA Water Separator in the Quest Airlock forced operational changes and brought about the re-design of the Water Separator to improve the useful life via modification kits. The on-orbit operational environment of the Airlock presented challenges that were not foreseen with the original design of the Water Separator. Operational changes were instituted to prolong the life of the third installed WS, while waiting for newly designed Water Separators to be delivered on-orbit. The modification kit design involved several different components of the Water Separator, including the innovative use of a fabrication technique to build the impellers used in Water Separators out of titanium instead of aluminum. The technique allowed for the cost effective production of the low quantity build. This paper will describe the failures of the Water Separators in the Quest Airlock, the operational constraints that were implemented to prolong the life of the installed Water Separators throughout the USOS, and the innovative re-design of the CCAA Water Separator.

Effect of simulated commercial flight on oxygenation in patients with interstitial lung disease and chronic obstructive pulmonary disease

PubMed Central

Seccombe, L; Kelly, P; Wong, C; Rogers, P; Lim, S; Peters, M

2004-01-01

Background: Commercial aircraft cabins provide a hostile environment for patients with underlying respiratory disease. Although there are algorithms and guidelines for predicting in-flight hypoxaemia, these relate to chronic obstructive pulmonary disease (COPD) and data for interstitial lung disease (ILD) are lacking. The purpose of this study was to evaluate the effect of simulated cabin altitude on subjects with ILD at rest and during a limited walking task. Methods: Fifteen subjects with ILD and 10 subjects with COPD were recruited. All subjects had resting arterial oxygen pressure (PaO2) of >9.3 kPa. Subjects breathed a hypoxic gas mixture containing 15% oxygen with balance nitrogen for 20 minutes at rest followed by a 50 metre walking task. Pulse oximetry (SpO2) was monitored continuously with testing terminated if levels fell below 80%. Arterial blood gas tensions were taken on room air at rest and after the resting and exercise phases of breathing the gas mixture. Results: In both groups there was a statistically significant decrease in arterial oxygen saturation (SaO2) and PaO2 from room air to 15% oxygen at rest and from 15% oxygen at rest to the completion of the walking task. The ILD group differed significantly from the COPD group in resting 15% oxygen SaO2, PaO2, and room air pH. Means for both groups fell below recommended levels at both resting and when walking on 15% oxygen. Conclusion: Even in the presence of acceptable arterial blood gas tensions at sea level, subjects with both ILD and COPD fall below recommended levels of oxygenation when cabin altitude is simulated. This is exacerbated by minimal exercise. Resting sea level arterial blood gas tensions are similarly poor in both COPD and ILD for predicting the response to simulated cabin altitude. PMID:15516473

Trace Contaminant Testing with the Orion Atmosphere Revitalization Technology

NASA Technical Reports Server (NTRS)

Button, Amy Lin; Sweterlitsch, Jeffrey; Broerman, Craig

2009-01-01

Every spacecraft atmosphere contains trace contaminants resulting from offgassing by cabin materials and human passengers. An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). Part of the risk mitigation effort for this new technology is the study of how atmospheric trace contaminants will affect and be affected by the technology. One particular area of concern is ammonia, which, in addition to the normal spacecraft sources, can also be off-gassed by the amine-based sorbent. In the first half of 2009, tests were performed with typical cabin atmosphere levels of five of the most common trace gases, most of which had not yet been tested with this technology. A subscale sample of the sorbent was exposed to each of the chemicals mixed into a stream of moist, CO2-laden air, and the CO2 adsorption capacity of the sorbent was compared before and after the exposure. After these typical-concentration chemicals were proven to have negligible effect on the subscale sample, tests proceeded on a full-scale test article in a sealed chamber with a suite of eleven contaminants. To isolate the effects of various test rig components, several extended-duration tests were run: without injection or scrubbing, with injection and without scrubbing, with injection and scrubbing by both the test article and dedicated trace contaminant filters, and with injection and scrubbing by only the test article. The high-level results of both the subscale and full-scale tests are examined in this paper.

78 FR 70892 - Airworthiness Directives; ATR-GIE Avions de Transport Régional Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-27

.../water leak, which is an indication that structural components within the window have begun to... detect and correct air/water leakage of the cockpit forward side window, which could lead to rapid cabin... are considered as precursors of this kind of failure. Air or water leakages between the z-bar and the...

77 FR 20572 - Airworthiness Directives; BAE Systems (Operations) Limited Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-05

... at the water trap/air drier unit of the forward discharge valve due to corrosion. This proposed AD... failure of the fuselage skin, leading to a possible sudden loss of cabin pressure. DATES: We must receive... surface anomalies (bulges and/or dents) of the fuselage skin at the water trap/air drier unit of the...

78 FR 67918 - Nondiscrimination on the Basis of Disability in Air Travel; Accessibility of Aircraft and Stowage...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-12

...] RIN 2105-AD87 Nondiscrimination on the Basis of Disability in Air Travel; Accessibility of Aircraft... nondiscriminatory service to passengers with disabilities. A requirement that U.S. carriers provide in-cabin space... Department's intention was that new aircraft would have a designated space (e.g., a closet or similar...

76 FR 32107 - Nondiscrimination on the Basis of Disability in Air Travel; Accessibility of Aircraft and Stowage...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

...] RIN 2105-AD87 Nondiscrimination on the Basis of Disability in Air Travel; Accessibility of Aircraft... Administration or applicable foreign government). When the requirement for in-cabin space for a folding passenger... designated space (e.g., a closet or similar compartment) in which a passenger's wheelchair could be stowed...

Measurements of propeller noise in a light turboprop airplane

NASA Technical Reports Server (NTRS)

Wilby, J. F.; Wilby, E. G.

1987-01-01

In-flight acoustic measurements have been made on the exterior and interior of a twin-engined turboprop airplane under controlled conditions to study data repeatability. It is found that the variability of the harmonic sound pressure levels in the cabin is greater than that for the exterior sound pressure levels, typical values for the standard deviation being +2.0 dB and -4.2 dB for the interior, versus +1.4 dB and -2.3 dB for the exterior. When insertion losses are determined for acoustic treatments in the cabin, the standard deviations of the data are typically + or - 6.5 dB. It is concluded that additional factors, such as accurate and repeatable selection of relative phase between propellers, controlled cabin-air-temperatures, installation of baseline acoustic absorption, and measurement of aircraft attitude, should be considered in order to reduce uncertainty in the measured data.

Vibration Transmission through Bearings with Application to Gearboxes

NASA Technical Reports Server (NTRS)

Fleming, David P.

2007-01-01

Cabin noise has become a major concern to manufacturers and users of helicopters. Gear noise is the largest part of this unwanted sound. The crucial noise path is generally considered to be from the gears through the gear-supporting shafts and bearings into the gearbox case, and from there either through the gearbox mounts or the surrounding air to the helicopter cabin. If the noise, that is, the gear and shaft vibration, can be prevented from traveling through the gearbox bearings, then the noise cannot make its way into the helicopter cabin. Thus the vibration-transmitting properties of bearings are of paramount importance. This paper surveys the literature concerning evaluation of properties for the types of bearings used in helicopter gearboxes. A simple model is proposed to evaluate vibration transmission, using measured or calculated bearing stiffness and damping. Less-commonly used types of gearbox bearings (e.g., fluid film) are evaluated for their potential in reducing vibration transmission.

Drag and Cooling with Various Forms of Cowling for a "Whirlwind" Radial Air-cooled Engine II

NASA Technical Reports Server (NTRS)

Weick, Fred E

1930-01-01

This report gives the results of the second portion of an investigation in the twenty-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics, on the cowling and cooling of a "Whirlwind" J-5 radial air-cooled engine. The first portion pertains to tests with a cabin fuselage. This report covers tests with several forms of cowling, including conventional types, individual fairings behind the cylinders, individual hoods over the over the cylinders, and the new N. A. C. A. complete cowling, all on an open cockpit fuselage. Drag tests were also made with a conventional engine nacelle, and with a nacelle having the new complete cowling. In the second part of the investigation the results found in the first part were substantiated. It was also found that the reduction in drag with the complete cowling over that with conventional cowling is greater with the smaller bodies than with the cabin fuselage; in fact, the gain in the case of the completely cowled nacelle is over twice that with the cabin fuselage. The individual fairings and hoods did not prove effective in reducing the drag. The results of flight tests on AT-5A airplane has been analyzed and found to agree very well with the results of the wind tunnel tests. (author)

Air quality and ocular discomfort aboard commercial aircraft.

PubMed

Backman, H; Haghighat, F

2000-10-01

Aircraft cabin air quality has been a subject of recent public health interest. Aircraft environments are designed according to standards to ensure the comfort and well-being of the occupants. The upper and lower limits of humidity set by ASHRAE standards are based on the maintenance of acceptable thermal conditions established solely on comfort considerations, including thermal sensation, skin wetness, skin dryness, dry eyes and ocular discomfort. The purpose of this study is to investigate the influence of air (carbon dioxide level, relative humidity, and temperature) aboard commercial aircraft on ocular discomfort and dry eye of aircraft personnel and passengers. Measurements of indoor air quality were performed in 15 different aircraft at different times and altitudes. Forty-two measurements of carbon dioxide, temperature, and humidity were performed with portable air samplers every 5 minutes. Passenger loads did not exceed 137 passengers. Thermal comfort rarely met ASHRAE standards. Low humidity levels and high carbon dioxide levels were found on the Airbus 320. The DC-9 had the highest humidity level and the Boeing-767 had the lowest carbon dioxide level. Air quality was poorest on the Airbus 320 aircraft. This poor level of air quality may cause intolerance to contact lenses, dry eyes, and may be a health hazard to both passengers and crew members. Improved ventilation and aircraft cabin micro-environments need to be made for the health and comfort of the occupants.

Spacecraft Cabin Air Quality Control and Its Application to Tight Buildings

NASA Technical Reports Server (NTRS)

Perry, J. L.; Graf, J. C.

1995-01-01

Air quality is an important consideration not only for the external environment, but also for the indoor environment. Most people spend a majority of their lives indoors and the air that they breathe is important to their physical and emotional well being. Since most modern building designs have focused on energy efficiency, less fresh air is brought from the outside. As a result, pollutants from building materials, furniture, cleaning, and cooking have no place to go. To make matters worse, most ventilation systems do not include any means for removing pollutants from the recycled air. Unfortunately, pollution at even a small level can result in eye, throat, and lung irritation in addition to chronic headaches, nausea, and fatigue. A spacecraft cabin, which represents the worst case in tight building design, requires special consideration of air quality since any effects pollutants may have on a crewmember can potentially place a mission or other crewmembers at risk. A detailed approach has been developed by the National Aeronautics and Space Administration (NASA) to minimize cabin atmosphere pollution and provide the crew with an environment which is as free of pollutants as possible. This approach is a combination of passive and active contamination control concepts involving the evaluation and selection of materials to be used onboard the spacecraft, the establishment of air quality standards to ensure crew health, and the use of active control means onboard the spacecraft to further ensure an acceptable atmosphere. This approach has allowed NASA to prevent illness by providing crewmembers with a cabin atmosphere which contains pollutant concentrations up to 100 times lower than those specified for terrestrial indoor environments. Standard building construction, however, does not take into account the potentially harmful effects of materials used in the construction process on the health of future occupants and relies primarily on remedial rather than preventive techniques when addressing contamination. This approach results in a building that theoretically has low operating costs, but may actually have high costs associated with lost work days, increased medical claims, decreased productivity, and problem remediation. A similar approach to NASA's may be adopted by the building construction community which can tap the extensive database of material offgassing properties that has been collected to support the space program. Many materials used by NASA are commercially available and are frequently used in building construction. In addition, computer models which have been developed for assessing various methods of active contamination control can be applied to building ventilation system design and the analysis of their economics. Through using NASA' s experience, the expense associated with the current remedial approach can be avoided.

Hydraulic fluids and jet engine oil: pyrolysis and aircraft air quality.

PubMed

van Netten, C; Leung, V

2001-01-01

Incidents of smoke in aircraft cabins often result from jet engine oil and/or hydraulic fluid that leaks into ventilation air, which can be subjected to temperatures that exceed 500 degrees C. Exposed flight-crew members have reported symptoms, including dizziness, nausea, disorientation, blurred vision, and tingling in the legs and arms. In this study, the authors investigated pyrolysis products of one jet engine oil and two hydraulic fluids at 525 degrees C. Engine oil was an important source of carbon monoxide. Volatile agents and organophosphate constituents were released from all the agents tested; however, the neurotoxin trimethyl propane phosphate was not found. The authors hypothesized that localized condensation of pyrolysis products in ventilation ducts, followed by mobilization when cabin heat demand was high, accounted for mid-flight incidents. The authors recommended that carbon monoxide data be logged continuously to capture levels during future incidents.

In-vehicle carbon dioxide concentration in commuting cars in Bangkok, Thailand.

PubMed

Luangprasert, Maytat; Vasithamrong, Chainarin; Pongratananukul, Suphasit; Chantranuwathana, Sunhapos; Pumrin, Suree; De Silva, I P D

2017-05-01

It is known that in-vehicle carbon dioxide (CO 2 ) concentration tends to increase due to occupant exhalation when the HVAC (heating, ventilation, and air conditioning) air is in recirculation mode. Field experiments were conducted to measure CO 2 concentration during typical commute in Bangkok, Thailand. The measured concentrations agreed with the concentration predicted using first-order mass balance equation, in both recirculating and outside air modes. The long-term transient decay of the concentration when the vehicle was parked and the HVAC system was turned off was also studied. This decay was found to follow Fickian diffusion process. The paper also provides useful operational details of the automotive HVAC system and fresh air ventilation exchange between cabin interior and exterior. Drivers in tropical Asian countries typically use HVAC recirculation mode in their automobiles. This behavior leads to excessive buildup of cabin CO 2 concentration levels. The paper describes the CO 2 buildup in a typical commute in Bangkok, Thailand. Auto manufacturers can potentially take measures to alleviate such high concentration levels. The paper also discusses the diffusion of CO 2 through the vehicle envelope, an area that has never been investigated before.

Pregnancy outcome among offspring of airline pilots and cabin attendants.

PubMed

Irgens, Agot; Irgens, Lorentz M; Reitan, Jon B; Haldorsen, Tor; Tveten, Ulf

2003-04-01

This study assessed the occurrence of perinatal death, low birthweight, preterm birth, and birth defects (total, major, neural tube defects, total cleft, cleft palate, hypospadias, and Down syndrome) in the offspring of airline pilots and cabin attendants. A cohort of offspring of airline pilots and cabin attendants was established and characterized in terms of parental exposure to cosmic radiation the year before birth or ever. Pregnancy outcome was derived from the Medical Birth Register of Norway. The reference group comprised offspring of parents without occupational exposure to cosmic radiation. No deviant risks were observed for the offspring of male pilots, either for the year preceding birth (N=2,111) or ever (N=2,356). Specific birth outcomes were fewer for the pilots than for the referents (N=1,621,186), except for Down syndrome, which was more frequent [odds ratio (OR) 1.41, 95% confidence interval (95% CI) 0.53-3.76]. For exposure the year preceding birth (N=2,512), the risk of low birthweight was lower for the female cabin attendants than for the referents (adjusted OR 0.83, 95% CI 0.69-1.00), while Down syndrome was more frequent (OR 1.44, 95% CI 0.60-3.47). For exposure ever (N=3346), the risk of low birthweight was lower (OR 0.82, 95% CI 0.70-0.96) for the cabin attendants, while hypospadias (OR 1.18, 95% CI 0.61-3.04) and Down syndrome (OR 1.79, 95% CI 0.03-3.45) were more frequent In general, offspring of air pilots and cabin attendants do not seem to be at increased risk of adverse pregnancy outcome.

An active structural acoustic control approach for the reduction of the structure-borne road noise

NASA Astrophysics Data System (ADS)

Douville, Hugo; Berry, Alain; Masson, Patrice

2002-11-01

The reduction of the structure-borne road noise generated inside the cabin of an automobile is investigated using an Active Structural Acoustic Control (ASAC) approach. First, a laboratory test bench consisting of a wheel/suspension/lower suspension A-arm assembly has been developed in order to identify the vibroacoustic transfer paths (up to 250 Hz) for realistic road noise excitation of the wheel. Frequency Response Function (FRF) measurements between the excitation/control actuators and each suspension/chassis linkage are used to characterize the different transfer paths that transmit energy through the chassis of the car. Second, a FE/BE model (Finite/Boundary Elements) was developed to simulate the acoustic field of an automobile cab interior. This model is used to predict the acoustic field inside the cabin as a response to the measured forces applied on the suspension/chassis linkages. Finally, an experimental implementation of ASAC is presented. The control approach relies on the use of inertial actuators to modify the vibration behavior of the suspension and the automotive chassis such that its noise radiation efficiency is decreased. The implemented algorithm consists of a MIMO (Multiple-Input-Multiple-Output) feedforward configuration with a filtered-X LMS algorithm using an advanced reference signal (width FIR filters) using the Simulink/Dspace environment for control prototyping.

Brominated flame retardant exposure of aircraft personnel.

PubMed

Strid, Anna; Smedje, Greta; Athanassiadis, Ioannis; Lindgren, Torsten; Lundgren, Håkan; Jakobsson, Kristina; Bergman, Åke

2014-12-01

The use of brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) in aircraft is the result of high fire safety demands. Personnel working in or with aircraft might therefore be exposed to several BFRs. Previous studies have reported PBDE exposure in flight attendants and in passengers. One other group that may be subjected to significant BFR exposure via inhalation, are the aircraft maintenance workers. Personnel exposure both during flights and maintenance of aircraft, are investigated in the present study. Several BFRs were present in air and dust sampled during both the exposure scenarios; PBDEs, hexabromocyclododecane (HBCDD), decabromodiphenyl ethane (DBDPE) and 1,2-bis (2,4,6-tribromophenoxy) ethane. PBDEs were also analyzed in serum from pilots/cabin crew, maintenance workers and from a control group of individuals without any occupational aircraft exposure. Significantly higher concentrations of PBDEs were found in maintenance workers compared to pilots/cabin crew and control subjects with median total PBDE concentrations of 19, 6.8 and 6.6 pmol g(-1) lipids, respectively. Pilots and cabin crew had similar concentrations of most PBDEs as the control group, except for BDE-153 and BDE-154 which were significantly higher. Results indicate higher concentrations among some of the pilots compared to the cabin crew. It is however, evident that the cabin personnel have lower BFR exposures compared to maintenance workers that are exposed to such a degree that their blood levels are significantly different from the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiological/biological/aerosol removal system

DOEpatents

Haslam, Jeffery J

2015-03-17

An air filter replacement system for existing buildings, vehicles, arenas, and other enclosed airspaces includes a replacement air filter for replacing a standard air filter. The replacement air filter has dimensions and air flow specifications that allow it to replace the standard air filter. The replacement air filter includes a filter material that removes radiological or biological or aerosol particles.

Airborne Pathogens inside Automobiles for Domestic Use: Assessing In-Car Air Decontamination Devices Using Staphylococcus aureus as the Challenge Bacterium.

PubMed

Sattar, Syed A; Zargar, Bahram; Wright, Kathryn E; Rubino, Joseph R; Ijaz, M Khalid

2017-05-15

Family cars represent ∼74% of the yearly global output of motorized vehicles. With a life expectancy of ∼8 decades in many countries, the average person spends >100 min daily inside the confined and often shared space of the car, with exposure to a mix of potentially harmful microbes. Can commercial in-car microbial air decontamination devices mitigate the risk? Three such devices (designated devices 1 to 3) with HEPA filters were tested in the modified passenger cabin (3.25 m 3 ) of a four-door sedan housed within a biosafety level 3 containment facility. Staphylococcus aureus (ATCC 6538) was suspended in a soil load to simulate the presence of body fluids and aerosolized into the car's cabin with a 6-jet Collison nebulizer. A muffin fan (80 mm by 80 mm, with an output of 0.17 m 3 /min) circulated the air inside. Plates (150 mm diameter) of Trypticase soy agar (TSA), placed inside a programmable slit-to-agar sampler, were held at 36 ± 1°C for 18 to 24 h and examined for CFU. The input dose of the test bacterium, its rate of biological decay, and the log 10 reductions by the test devices were analyzed. The arbitrarily set performance criterion was the time in hours a device took for a 3-log 10 reduction in the level of airborne challenge bacterium. On average, the level of S. aureus challenge in the air varied between 4.2 log 10 CFU/m 3 and 5.5 log 10 CFU/m 3 , and its rate of biological decay was -0.0213 ± 0.0021 log 10 CFU/m 3 /min. Devices 1 to 3 took 2.3, 1.5, and 9.7 h, respectively, to meet the performance criterion. While the experimental setup was tested using S. aureus as an archetypical airborne pathogen, it can be readily adapted to test other types of pathogens and technologies. IMPORTANCE This study was designed to test the survival of airborne pathogens in the confined and shared space of a family automobile as well as to assess claims of devices marketed for in-car air decontamination. The basic experimental setup and the test protocols reported are versatile enough for work with all major types of airborne human pathogens and for testing a wide variety of air decontamination technologies. This study could also lay the foundation for a standardized test protocol for use by device makers as well as regulators for the registration of such devices. Copyright © 2017 American Society for Microbiology.

Airborne Pathogens inside Automobiles for Domestic Use: Assessing In-Car Air Decontamination Devices Using Staphylococcus aureus as the Challenge Bacterium

PubMed Central

Zargar, Bahram; Wright, Kathryn E.; Rubino, Joseph R.; Ijaz, M. Khalid

2017-01-01

ABSTRACT Family cars represent ∼74% of the yearly global output of motorized vehicles. With a life expectancy of ∼8 decades in many countries, the average person spends >100 min daily inside the confined and often shared space of the car, with exposure to a mix of potentially harmful microbes. Can commercial in-car microbial air decontamination devices mitigate the risk? Three such devices (designated devices 1 to 3) with HEPA filters were tested in the modified passenger cabin (3.25 m3) of a four-door sedan housed within a biosafety level 3 containment facility. Staphylococcus aureus (ATCC 6538) was suspended in a soil load to simulate the presence of body fluids and aerosolized into the car's cabin with a 6-jet Collison nebulizer. A muffin fan (80 mm by 80 mm, with an output of 0.17 m3/min) circulated the air inside. Plates (150 mm diameter) of Trypticase soy agar (TSA), placed inside a programmable slit-to-agar sampler, were held at 36 ± 1°C for 18 to 24 h and examined for CFU. The input dose of the test bacterium, its rate of biological decay, and the log10 reductions by the test devices were analyzed. The arbitrarily set performance criterion was the time in hours a device took for a 3-log10 reduction in the level of airborne challenge bacterium. On average, the level of S. aureus challenge in the air varied between 4.2 log10 CFU/m3 and 5.5 log10 CFU/m3, and its rate of biological decay was −0.0213 ± 0.0021 log10 CFU/m3/min. Devices 1 to 3 took 2.3, 1.5, and 9.7 h, respectively, to meet the performance criterion. While the experimental setup was tested using S. aureus as an archetypical airborne pathogen, it can be readily adapted to test other types of pathogens and technologies. IMPORTANCE This study was designed to test the survival of airborne pathogens in the confined and shared space of a family automobile as well as to assess claims of devices marketed for in-car air decontamination. The basic experimental setup and the test protocols reported are versatile enough for work with all major types of airborne human pathogens and for testing a wide variety of air decontamination technologies. This study could also lay the foundation for a standardized test protocol for use by device makers as well as regulators for the registration of such devices. PMID:28389537

KSC00padig049

NASA Image and Video Library

2000-10-01

Jan Zysko (left) and Rich Mizell (right) test a Personal Cabin Pressure Altitude Monitor in an altitude chamber at Tyndall Air Force Base in Florida. Zysko invented the pager-sized monitor that alerts wearers of a potentially dangerous or deteriorating cabin pressure altitude condition, which can lead to life-threatening hypoxia. Zysko is chief of the KSC Spaceport Engineering and Technology directorate's data and electronic systems branch. Mizell is a Shuttle processing engineer. The monitor, which has drawn the interest of such organizations as the Federal Aviation Administration for use in commercial airliners and private aircraft, was originally designed to offer Space Shuttle and Space Station crew members added independent notification about any depressurization

KSC-00padig049

NASA Image and Video Library

2000-10-01

Jan Zysko (left) and Rich Mizell (right) test a Personal Cabin Pressure Altitude Monitor in an altitude chamber at Tyndall Air Force Base in Florida. Zysko invented the pager-sized monitor that alerts wearers of a potentially dangerous or deteriorating cabin pressure altitude condition, which can lead to life-threatening hypoxia. Zysko is chief of the KSC Spaceport Engineering and Technology directorate's data and electronic systems branch. Mizell is a Shuttle processing engineer. The monitor, which has drawn the interest of such organizations as the Federal Aviation Administration for use in commercial airliners and private aircraft, was originally designed to offer Space Shuttle and Space Station crew members added independent notification about any depressurization

Trace Contaminant Testing with the Orion Atmosphere Revitalization Technology

NASA Technical Reports Server (NTRS)

Button, Amy B.; Sweterlitsch, Jeffrey J.; Broerman, Craig D.; Campbell, Melissa L.

2010-01-01

Every spacecraft atmosphere contains trace contaminants resulting from offgassing by cabin materials and human passengers. An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). Part of the risk mitigation effort for this new technology is the study of how atmospheric trace contaminants will affect and be affected by the technology. One particular area of concern is ammonia, which, in addition to the normal spacecraft sources, can also be offgassed by the amine-based sorbent. In the spring of 2009, tests were performed at Johnson Space Center (JSC) with typical cabin atmosphere levels of five of the most common trace gases, most of which had not yet been tested with this technology. A subscale sample of the sorbent was exposed to each of the chemicals mixed into a stream of moist, CO2-laden air, and the CO2 adsorption capacity of the sorbent was compared before and after the exposure. After these typical-concentration chemicals were proven to have negligible effect on the subscale sample, tests proceeded on a full-scale test article in a sealed chamber with a suite of eleven contaminants. To isolate the effects of various test rig components, several extended-duration tests were run: without injection or scrubbing, with injection and without scrubbing, with injection of both contaminants and metabolic CO2 and water vapor loads and scrubbing by both the test article and dedicated trace contaminant filters, and with the same injections and scrubbing by only the test article. The high-level results of both the subscale and full-scale tests are examined in this paper.

Space and motion perception and discomfort in air travel.

PubMed

Ramos, Renato T; de Mattos, Danielle A; Rebouças, J Thales S; Ranvaud, Ronald D

2012-12-01

The perception of comfort during air trips is determined by several factors. External factors like cabin design and environmental parameters (temperature, humidity, air pressure, noise, and vibration) interact with individual characteristics (anxiety traits, fear of flying, and personality) from arrival at the airport to landing at the destination. In this study, we investigated the influence of space and motion discomfort (SMD), fear of heights, and anxiety on comfort perception during all phases of air travel. We evaluated 51 frequent air travelers through a modified version of the Flight Anxiety Situations Questionnaire (FAS), in which new items were added and where the subjects were asked to report their level of discomfort or anxiety (not fear) for each phase of air travel (Chronbach's alpha = 0.974). Correlations were investigated among these scales: State-Trait Anxiety Inventory (STAI), Cohen's Acrophobia Questionnaire, and the Situational Characteristics Questionnaire (SitQ, designed to estimate SMD levels). Scores of SitQ correlated with discomfort in situations involving space and movement perception (Pearson's rho = 0.311), while discomfort was associated with cognitive mechanisms related to scores in the anxiety scales (Pearson's rho = 0.375). Anxiety traits were important determinants of comfort perception before and after flight, while the influence of SMD was more significant during the time spent in the aircraft cabin. SMD seems to be an important modulator of comfort perception in air travel. Its influence on physical well being and probably on cognitive performance, with possible effects on flight safety, deserves further investigation.

Trace Contaminant Control During the International Space Station's On-Orbit Assembly and Outfitting

NASA Technical Reports Server (NTRS)

Perry, J. L.

2017-01-01

Achieving acceptable cabin air quality must balance competing elements during spacecraft design, assembly, ground processing, and flight operations. Among the elements that contribute to the trace chemical contaminant load and, therefore, the cabin air quality aboard crewed spacecraft are the vehicle configuration, crew size and activities, mission duration and objectives, materials selection, and vehicle manufacturing and preflight ground processing methods. Trace chemical contaminants produced from pervasive sources such as equipment offgassing, human metabolism, and cleaning fluids during preflight ground processing present challenges to maintaining acceptable cabin air quality. To address these challenges, both passive and active contamination control techniques are used during a spacecraft's design, manufacturing, preflight preparation, and operational phases. Passive contamination control methods seek to minimize the equipment offgassing load by selecting materials, manufacturing processes, preflight preparation processes, and in-flight operations that have low chemical offgassing characteristics. Passive methods can be employed across the spacecraft's entire life cycle from conceptual design through flight operations. However, because the passive contamination control techniques cannot fully eliminate the contaminant load, active contamination control equipment must be deployed aboard the spacecraft to purify and revitalize the cabin atmosphere during in-flight operations. Verifying that the passive contamination control techniques have successfully maintained the total trace contaminant load within the active contamination control equipment's capabilities occurs late in the preflight preparation stages. This verification consists of subjecting the spacecraft to an offgassing test to determine the trace contaminant load. This load is then assessed versus the active contamination control equipment's capabilities via trace contaminant control (TCC) engineering analysis. During the International Space Station's (ISS's) on-orbit assembly and outfitting, a series of engineering analyses were conducted to evaluate how effective the passive TCC methods were relative to providing adequate operational margin for the active TCC equipment's capabilities aboard the ISS. These analyses were based on habitable module and cargo vehicle offgassing test results. The offgassing test for a fully assembled module or cargo vehicle is an important preflight spacecraft evaluation method that has been used successfully during all crewed spacecraft programs to provide insight into how effectively the passive contamination control methods limit the equipment offgassing component of the overall trace contaminant generation load. The progression of TCC assessments beginning in 1998 with the ISS's first habitable element launch and continuing through the final pressurized element's arrival in 2010 are presented. Early cargo vehicle flight assessments between 2008 and 2011 are also presented as well as a discussion on predictive methods for assessing cargo via a purely analytical technique. The technical approach for TCC employed during this 13-year period successfully maintained the cabin atmospheric quality within specified parameters during the technically challenging ISS assembly and outfitting stages. The following narrative provides details on the important role of spacecraft offgassing testing, trace contaminant performance requirements, and flight rules for achieving the ultimate result-a cabin environment that enables people to live and work safely in space.

Impact of scaling and body movement on contaminant transport in airliner cabins

NASA Astrophysics Data System (ADS)

Mazumdar, Sagnik; Poussou, Stephane B.; Lin, Chao-Hsin; Isukapalli, Sastry S.; Plesniak, Michael W.; Chen, Qingyan

2011-10-01

Studies of contaminant transport have been conducted using small-scale models. This investigation used validated Computational Fluid Dynamics (CFD) to examine if a small-scale water model could reveal the same contaminant transport characteristics as a full-scale airliner cabin. But due to similarity problems and the difficulty of scaling the geometry, a perfect scale up from a small water model to an actual air model was found to be impossible. The study also found that the seats and passengers tended to obstruct the lateral transport of the contaminants and confine their spread to the aisle of the cabin. The movement of a crew member or a passenger could carry a contaminant in its wake to as many rows as the crew member or passenger passed. This could be the reason why a SARS infected passenger could infect fellow passengers who were seated seven rows away. To accurately simulate the contaminant transport, the shape of the moving body should be a human-like model.

Characterization of VOC Emission from Materials in Vehicular Environment at Varied Temperatures: Correlation Development and Validation

PubMed Central

Xiong, Jianyin; Yang, Tao; Tan, Jianwei; Li, Lan; Ge, Yunshan

2015-01-01

The steady state VOC concentration in automobile cabin is taken as a good indicator to characterize the material emission behaviors and evaluate the vehicular air quality. Most studies in this field focus on experimental investigation while theoretical analysis is lacking. In this paper we firstly develop a simplified physical model to describe the VOC emission from automobile materials, and then derive a theoretical correlation between the steady state cabin VOC concentration (C a) and temperature (T), which indicates that the logarithm of C a/T 0.75 is in a linear relationship with 1/T. Experiments of chemical emissions in three car cabins at different temperatures (24°C, 29°C, 35°C) were conducted. Eight VOCs specified in the Chinese National Standard GB/T 27630–2011 were taken for analysis. The good agreement between the correlation and experimental results from our tests, as well as the data taken from literature demonstrates the effectiveness of the derived correlation. Further study indicates that the slope and intercept of the correlation follows linear association. With the derived correlation, the steady state cabin VOC concentration different from the test conditions can be conveniently obtained. This study should be helpful for analyzing temperature-dependent emission phenomena in automobiles and predicting associated health risks. PMID:26452146

Changes in ocular and nasal signs and symptoms among air crew in relation to air humidification on intercontinental flights.

PubMed

Norbäck, Dan; Lindgren, Torsten; Wieslander, Gunilla

2006-04-01

This study evaluates the influence of air humidification in aircraft on symptoms, tear-film stability, nasal patency, and peak expiratory flow. Commercial air crew (N=71) were given a medical examination during eight flights from Stockholm to Chicago and eight flights in the opposite direction. Examinations were done onboard one Boeing 767 aircraft equipped with an evaporation humidifier in the forward part of the cabin. The investigators followed the air crew, staying one night in Chicago and returning with the same crew. Four of the flights had the air humidification device active in-flight to Chicago and deactivated when returning to Stockholm. The other four flights had the inverse humidification sequence. The humidification sequence was randomized and double blind. Hygienic measurements were performed. The humidification increased the relative air humidity by 10% in the 1st row in business class, by 3% in the last row (39th row) in tourist class, and by 3% in the cockpit. Air humidification increased tear-film stability and nasal patency and decreased ocular, nasal, and dermal symptoms and headache. The mean concentration of viable bacteria [77-108 colony-forming units (cfu)/m(3)], viable molds (74-84 cfu/m(3)), and particulate matter (1-8 microg/m(3)) was low, both during the humidified and non-humidified flights. Relative air humidity is low (10-12%) during intercontinental flights and can be increased by the use of a ceramic evaporation humidifier, without any measurable increase of microorganisms in cabin air. Air humidification could increase passenger and crew comfort by increasing tear-film stability and nasal patency and reducing various symptoms.

Apparatus for real-time airborne particulate radionuclide collection and analysis

DOEpatents

Smart, John E.; Perkins, Richard W.

2001-01-01

An improved apparatus for collecting and analyzing an airborne particulate radionuclide having a filter mounted in a housing, the housing having an air inlet upstream of the filter and an air outlet downstream of the filter, wherein an air stream flows therethrough. The air inlet receives the air stream, the filter collects the airborne particulate radionuclide and permits a filtered air stream to pass through the air outlet. The improvement which permits real time counting is a gamma detecting germanium diode mounted downstream of the filter in the filtered air stream. The gamma detecting germanium diode is spaced apart from a downstream side of the filter a minimum distance for a substantially maximum counting detection while permitting substantially free air flow through the filter and uniform particulate radionuclide deposition on the filter.

Considerations for Conducting Plant Research in Open Atmosphere Chambers on ISS

NASA Astrophysics Data System (ADS)

Wheeler, Raymond; Hummerick, Mary; Graham, Thomas; Dixit, Anirudha; Massa, Gioia

The access to spaceflight and now the International Space Station has provided plant researchers a laboratory that is in continuous freefall (near weightlessness). As veteran spaceflight investigators know too well, research in space is difficult to conduct and the experiments are often confounded by secondary events. An example of this is the distribution of water and gases in rooting systems in µ-gravity. Since the water does not settle to the ”bottom” of the rooting media in space, there can be poor distribution and movement of water and oxygen, which in turn can stress the plants. This also creates challenges for conducting ground controls where the logical approach is to use the same volume of water as in space. But under 1-g, the water does settle to the bottom of the root zone, which leaves less in the upper profile of the rooting medium. In addition, some chambers such as the Russian Svet (on Mir), Lada (ISS), and NASA’s Veggie chamber were or are open to the cabin air. This simplifies the hardware development and allows the use of cabin air for cooling and supplying CO2 to the plants. Yet it also exposes the plants to the cabin air, which could have very high CO2 levels (e.g., 3000 to 6000 ppm), low humidity, and trace contaminants that might be below the limits for human concerns but could still affect plants. A known effect of these “super-elevated” CO2 levels on many dicot species is increased transpiration due to elevated stomatal conductance, both during the light and the dark cycles. Examples of these secondary effects will be discussed, along with potential approaches for conducting adequate ground controls.

Quasi Real Time Data Analysis for Air Quality Monitoring with an Electronic Nose

NASA Technical Reports Server (NTRS)

Zhou, Hanying; Shevade, Abhijit V.; Pelletier, Christine C.; Homer, Margie L.; Ryan, M. Amy

2006-01-01

Cabin Air Quality Monitoring: A) Functions; 1) Incident monitor for targeted contaminants exceeding targeted concentrations. Identify and quantify. 2) Monitor for presence of compounds associated with fires or overheating electronics. 3) Monitor clean-up process. B) Characteristics; 1) Low mass, low power device. 2) Requires little crew time for maintenance and calibration. 3) Detects, identifies and quantifies selected chemical species at or below 24 hour SMAC.

Carbon Dioxide Concentrations and Temperatures within Tour Buses under Real-Time Traffic Conditions.

PubMed

Chiu, Chun-Fu; Chen, Ming-Hung; Chang, Feng-Hsiang

2015-01-01

This study monitored the carbon dioxide (CO2) concentrations and temperatures of three 43-seat tour buses with high-passenger capacities in a course of a three-day, two-night school excursion. Results showed that both driver zones and passenger zones of the tour buses achieved maximum CO2 concentrations of more than 3000 ppm, and maximum daily average concentrations of 2510.6 and 2646.9 ppm, respectively. The findings confirmed that the CO2 concentrations detected in the tour buses exceeded the indoor air quality standard of Taiwan Environmental Protection Administration (8 hr-CO2: 1000 ppm) and the air quality guideline of Hong Kong Environmental Protection Department (1 hr-CO2: 2500 ppm for Level 1 for buses). Observations also showed that high-capacity tour bus cabins with air conditioning system operating in recirculation mode are severely lacking in air exchange rate, which may negatively impact transportation safety. Moreover, the passenger zones were able to maintain a temperature of between 20 and 25°C during travel, which effectively suppresses the dispersion of volatile organic compounds. Finally, the authors suggest that in the journey, increasing the ventilation frequency of tour bus cabin, which is very beneficial to maintain the travel safety and enhance the quality of travel.

Carbon Dioxide Concentrations and Temperatures within Tour Buses under Real-Time Traffic Conditions

PubMed Central

Chiu, Chun-Fu; Chen, Ming-Hung; Chang, Feng-Hsiang

2015-01-01

This study monitored the carbon dioxide (CO2) concentrations and temperatures of three 43-seat tour buses with high-passenger capacities in a course of a three-day, two-night school excursion. Results showed that both driver zones and passenger zones of the tour buses achieved maximum CO2 concentrations of more than 3000 ppm, and maximum daily average concentrations of 2510.6 and 2646.9 ppm, respectively. The findings confirmed that the CO2 concentrations detected in the tour buses exceeded the indoor air quality standard of Taiwan Environmental Protection Administration (8 hr-CO2: 1000 ppm) and the air quality guideline of Hong Kong Environmental Protection Department (1 hr-CO2: 2500 ppm for Level 1 for buses). Observations also showed that high-capacity tour bus cabins with air conditioning system operating in recirculation mode are severely lacking in air exchange rate, which may negatively impact transportation safety. Moreover, the passenger zones were able to maintain a temperature of between 20 and 25°C during travel, which effectively suppresses the dispersion of volatile organic compounds. Finally, the authors suggest that in the journey, increasing the ventilation frequency of tour bus cabin, which is very beneficial to maintain the travel safety and enhance the quality of travel. PMID:25923722

Atmospheric profiles of Black Carbon at remote locations using light-weight airborne Aethalometers

NASA Astrophysics Data System (ADS)

Hansen, A. D.; Močnik, G.; Drinovec, L.; Lenarcic, M.

2012-12-01

While measurements of atmospheric aerosols are routinely performed at ground-level around the world, there is far less knowledge of their concentrations at altitude: yet this data is a crucial requirement for our understanding of the dispersion of pollutants of anthropogenic origin, with their associated effects on radiative forcing, cloud condensation, and other adverse phenomena. Black Carbon (BC) is a unique tracer for combustion emissions, and can be detected rapidly and with great sensitivity by filter-based optical methods. It has no non-combustion sources and is not transformed by atmospheric processes. Recent technical advances have developed light-weight miniaturized instruments which can be operated on light aircraft or carried aboard commercial passenger flights. From January to April 2012, a single-seat ultra-light aircraft flew around the world on a scientific, photographic and environmental-awareness mission. The flight track crossed all seven continents and all major oceans, with altitudes up to 8.9 km ASL. The aircraft carried a custom-developed high-sensitivity dual-wavelength light-weight Aethalometer, operating at 370 and 880 nm with special provision to compensate for the effects of changing pressure, temperature and humidity. The instrument recorded BC concentrations with high temporal resolution and sensitivity better than 5 ng/m3. We present examples of data from flight tracks over remote oceans, uninhabited land masses, and densely populated areas, analyzing the spectral dependence of absorption to infer the contributions to BC from fossil fuel vs. biomass combustion, and aggregating the data into vertical profiles. The regional and long range transport of BC may be investigated using back-trajectories. We have also operated miniature instruments in the passenger cabins of long-distance commercial aircraft. Since there are no combustion sources within the cabin, any BC in the ventilation air must necessarily have originated from the outside air near the tropopause at the operating altitude of 10 ~ 12 km. We shall compare some of these data with the data from the ultra-light aircraft at remote locations, albeit at lower altitudes. References http://www.cgsplus.si/portals/0/WGF/wglfPage.htm Science, 335 (6074), p. 1286, 16 March 2012

Experimental Investigation of Thermal Performance in a Vehicle Cabin Test Setup With Pcm in the Roof

NASA Astrophysics Data System (ADS)

Purusothaman, M.; kota, Saichand; Cornilius, C. Sam; Siva, R.

2017-05-01

Heat flow from the roof with radiation through glass windows obviously high level that contributes to the total heat gained of a vehicle cabin. The cabin temperature of closed stationary vehicles in direct sunlight can quickly rise to a very level that may damage property and harm children or pets left in the vehicle. The problem that is faced by many car users today is very hot interior after certain minutes or hours of parking in open or un-shaded parking area. The heat accumulated inside the vehicle with undesired temperature rise would cause the parts of the car’s interior to degrade. Even the passengers are affected with the thermal condition inside the vehicle itself. The passenger has to wait for a certain time before getting into the car to cool down the interior condition either by lowering down the window or switching on the air conditioner at high speed that really affect the fuel consumption. A new roofing structure to improve its total thermal resistance is developed. Its uses phase change material properties to trap the heat from solar radiation and then release it back to the outer atmosphere by external convection when the vehicle is in use or during the nocturnal cycle. Phase change material, which has become an attractive means to store. Thermal energy, which has a wide range of applications, has been used. Phase change material has a high heat of fusion which is able to store and release large amount of energy. This PCM has been insulated in the roof of the vehicle to arrest the heat entering into the vehicle cabin. Experimental and numerical analyses have been conducted to compare the thermal performance of the new roofing structure and the normal roofing. By this experiment, the cooling process of the cabin could be much lower. The experimental investigation revealed that, on a hot day, the interior temperature of the vehicles cabin was approximately 22ºCe higher than the ambient temperature. The results show that the new roofing structure could effectively reduce the inlet of heat from the roof into the cabin. As a result, the interior temperature of the cabin could be much lower.

Use Of The Operational Air Quality Monitor (AQM) For In-Flight Water Testing Project

NASA Technical Reports Server (NTRS)

Macatangay, Ariel

2014-01-01

A primary requirement for manned spaceflight is Environmental Health which ensures air and water contaminants, acoustic profiles, microbial flora, and radiation exposures within the cabin are maintained to levels needed for crew health and for vehicle system functionality. The reliance on ground analyses of returned samples is a limitation in the current environmental monitoring strategy that will prevent future Exploration missions beyond low-Earth orbit. This proposal attempts to address this shortcoming by advancing in-flight analyses of water and air. Ground analysis of in-flight, air and water samples typically employ vapor-phase analysis by gas chromatography-mass spectrometry (GC-MS) to identify and quantify organic compounds present in the samples. We envision the use of newly-developed direct ionization approaches as the most viable avenue leading towards an integrated analytical platform for the monitoring of water, air, and, potentially bio-samples in the cabin environment. Development of an in-flight instrument capable of analyzing air and water samples would be the logical next step to meeting the environmental monitoring needs of Exploration missions. Currently, the Air Quality Monitor (AQM) on-board ISS provides this specific information for a number of target compounds in the air. However, there is a significant subset of common target compounds between air and water. Naturally, the following question arises, "Can the AQM be used for both air and water quality monitoring?" Previous directorate-level IR&D funding led to the development of a water sample introduction method for mass spectrometry using electrothermal vaporization (ETV). This project will focus on the integration of the ETV with a ground-based AQM. The capabilities of this integrated platform will be evaluated using a subset of toxicologically important compounds.

Advanced ETC/LSS computerized analytical models, CO2 concentration. Volume 1: Summary document

NASA Technical Reports Server (NTRS)

Taylor, B. N.; Loscutoff, A. V.

1972-01-01

Computer simulations have been prepared for the concepts of C02 concentration which have the potential for maintaining a C02 partial pressure of 3.0 mmHg, or less, in a spacecraft environment. The simulations were performed using the G-189A Generalized Environmental Control computer program. In preparing the simulations, new subroutines to model the principal functional components for each concept were prepared and integrated into the existing program. Sample problems were run to demonstrate the methods of simulation and performance characteristics of the individual concepts. Comparison runs for each concept can be made for parametric values of cabin pressure, crew size, cabin air dry and wet bulb temperatures, and mission duration.

KSC-04pd0545

NASA Image and Video Library

2004-03-17

KENNEDY SPACE CENTER, FLA. - In the middeck of Endeavour, in the Orbiter Processing Facility, Center Director Jim Kennedy (far left) watches as a technician gets ready to lower himself through the LiOH door into the Environmental Control and Life Support System (ECLSS) bay. LiOH refers to lithium hydroxide, canisters of which are stored in the ECLSS bay under the middeck floor. During flight, cabin air from the cabin fan is ducted to two LiOH canisters, where carbon dioxide is removed and activated charcoal removes odors and trace contaminants. Kennedy is taking an opportunity to learn first-hand what workers are doing to enable Return to Flight. Endeavour is in an Orbiter Major Modification period.

Nanoporous Materials in Atmosphere Revitalization. Chapter 1

NASA Technical Reports Server (NTRS)

Hernandez-Maldonado, J.; Ishikawa, Yasuyuki; Luna, Bernadette; Junaedi, Christian; Mulloth, Lila; Perry, Jay L.; Raptis, Raphael G.; Roychoudhury, Subir

2012-01-01

Atmospheric Revitalization (AR) is the term the National Aeronautics and Space Administration (NASA) uses to encompass the engineered systems that maintain a safe, breathable gaseous atmosphere inside a habitable space cabin. An AR subsystem is a key part of the Environmental Control and Life Support (ECLS) system for habitable space cabins. The ultimate goal for AR subsystem designers is to 'close the loop', that is, to capture gaseous human metabolic products, specifically water vapor (H2O) and Carbon dioxide (CO2), for maximal Oxygen (o2) recovery and to make other useful resources from these products. The AR subsystem also removes trace chemical contaminants from the cabin atmosphere to preserve cabin atmospheric quality, provides O2 and may include instrumentation to monitor cabin atmospheric quality. Long duration crewed space exploration missions require advancements in AR process technologies in order to reduce power consumption and mass and to increase reliability compared to those used for shorter duration missions that are typically limited to Low Earth Orbit. For example, current AR subsystems include separate processors and process air flow loops for removing metabolic CO2 and volatile organic tract contaminants (TCs). Physical adsorbents contained in fixed, packed beds are employed in these processors. Still, isolated pockets of high carbon dioxide have been suggested as a trigger for crew headaches and concern persists about future cabin ammonia (NH3) levels as compared with historical flights. Developers are already focused on certain potential advancements. ECLS systems engineers envision improving the AR subsystem by combining the functions of TC control and CO2 removal into a single regenerable process and moving toward structured sorbents - monoliths - instead of granular material. Monoliths present a lower pressure drop and eliminate particle attrition problems that result from bed containment. New materials and configurations offer promise for lowering cabin levels of CO2 and NH3 as well as reducing power requirements and increasing reliability. This chapter summarizes the challenges faced by ECLS system engineers in pursuing these goals, and the promising materials developments that may be part of the technical solution for challenges of crewed space exploration beyond LEO.

14 CFR 25.859 - Combustion heater fire protection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Combustion heater fire protection. 25.859....859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... surrounds the combustion chamber. However, no fire extinguishment is required in cabin ventilating air...

14 CFR 25.859 - Combustion heater fire protection.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Combustion heater fire protection. 25.859....859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... surrounds the combustion chamber. However, no fire extinguishment is required in cabin ventilating air...

14 CFR 25.859 - Combustion heater fire protection.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Combustion heater fire protection. 25.859....859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... surrounds the combustion chamber. However, no fire extinguishment is required in cabin ventilating air...

14 CFR 25.859 - Combustion heater fire protection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heater fire protection. 25.859....859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... surrounds the combustion chamber. However, no fire extinguishment is required in cabin ventilating air...

14 CFR 25.859 - Combustion heater fire protection.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Combustion heater fire protection. 25.859....859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... surrounds the combustion chamber. However, no fire extinguishment is required in cabin ventilating air...

Analysis of the Ability of United States and Russian Trace Contaminant Control Systems to Meet U.S. 180-Day and Russian 360-Day Spacecraft Maximum Allowable Concentrations

NASA Technical Reports Server (NTRS)

Perry, J. L.

2016-01-01

As the Space Station Freedom program transitioned to become the International Space Station (ISS), uncertainty existed concerning the performance capabilities for U.S.- and Russian-provided trace contaminant control (TCC) equipment. In preparation for the first dialogue between NASA and Russian Space Agency personnel in Moscow, Russia, in late April 1994, an engineering analysis was conducted to serve as a basis for discussing TCC equipment engineering assumptions as well as relevant assumptions on equipment offgassing and cabin air quality standards. The analysis presented was conducted as part of the efforts to integrate Russia into the ISS program via the early ISS Multilateral Medical Operations Panel's Air Quality Subgroup deliberations. This analysis, served as a basis for technical deliberations that established a framework for TCC system design and operations among the ISS program's international partners that has been instrumental in successfully managing the ISS common cabin environment.

The occupational health and safety of flight attendants.

PubMed

Griffiths, Robin F; Powell, David M C

2012-05-01

In order to perform safety-critical roles in emergency situations, flight attendants should meet minimum health standards and not be impaired by factors such as fatigue. In addition, the unique occupational and environmental characteristics of flight attendant employment may have consequential occupational health and safety implications, including radiation exposure, cancer, mental ill-health, musculoskeletal injury, reproductive disorders, and symptoms from cabin air contamination. The respective roles of governments and employers in managing these are controversial. A structured literature review was undertaken to identify key themes for promoting a future agenda for flight attendant health and safety. Recommendations include breast cancer health promotion, implementation of Fatigue Risk Management Systems, standardization of data collection on radiation exposure and health outcomes, and more coordinated approaches to occupational health and safety risk management. Research is ongoing into cabin air contamination incidents, cancer, and fatigue as health and safety concerns. Concerns are raised that statutory medical certification for flight attendants will not benefit either flight safety or occupational health.

A case study on identification of airborne organic compounds and time courses of their concentrations in the cabin of a new car for private use.

PubMed

Yoshida, Toshiaki; Matsunaga, Ichiro

2006-01-01

The cabin of an automobile can be considered to be a part of the living environment because many people spend long periods of time during business, shopping, recreation or travel activities. However, little is known about the interior air contamination due to organic compounds diffusing from the interior materials used in the interior of automobiles. In the present study, the compounds in the interior air of a new car were identified, and the time courses of their concentrations were examined for over 3 years after the delivery (July, 1999). A total of 162 organic compounds, involving many aliphatic hydrocarbons and aromatic hydrocarbons, were identified. High concentrations of n-nonane (458 microg/m(3) on the day following delivery), n-decane (1301 microg/m(3)), n-undecane (1616 microg/m(3)), n-dodecane (716 microg/m(3)), n-tridecane (320 microg/m(3)), 1-hexadecene (768 microg/m(3)), ethylbenzene (361 microg/m(3)), xylene (4003 microg/m(3)) and 2,2'-azobis(isobutyronitrile) (429 microg/m(3)) were detected, and the sum of the concentrations determined for all compounds excluding formaldehyde (TVOC) was approximately 14 mg/m(3) on the day after the delivery. The concentrations of most compounds decreased with time, but increased with a rise of the interior temperature. The TVOC concentration in the next summer (July, 2000) was approximately one-tenth of the initial concentration. During the 3-year study period, the TVOC concentrations in summer exceeded the indoor guideline value (300 mug/m(3)) proposed by [Seifert B. Volatile organic compounds. In: Maroni M, Seifert B, Lindvall T, editors. Indoor air quality. A comprehensive reference book. Air quality monographs, vol. 3. Netherlands: Elsevier Science; 1995. p. 819-21]. The interior temperature and days lapsed after delivery were the main factors affecting the interior concentrations of most compounds according to multiple linear regression analysis. The results of this study offer useful fundamental data for investigations on air pollution in automotive cabins due to the organic compounds diffusing from the interior materials.

Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function, and endothelial activation.

PubMed

Toff, William D; Jones, Chris I; Ford, Isobel; Pearse, Robert J; Watson, Henry G; Watt, Stephen J; Ross, John A S; Gradwell, David P; Batchelor, Anthony J; Abrams, Keith R; Meijers, Joost C M; Goodall, Alison H; Greaves, Michael

2006-05-17

The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level. To determine whether hypobaric hypoxia, which may be encountered during air travel, activates hemostasis. A single-blind, crossover study, performed in a hypobaric chamber, to assess the effect of an 8-hour seated exposure to hypobaric hypoxia on hemostasis in 73 healthy volunteers, which was conducted in the United Kingdom from September 2003 to November 2005. Participants were screened for factor V Leiden G1691A and prothrombin G20210A mutation and were excluded if they tested positive. Blood was drawn before and after exposure to assess activation of hemostasis. Individuals were exposed alternately (> or =1 week apart) to hypobaric hypoxia, similar to the conditions of reduced cabin pressure during commercial air travel (equivalent to atmospheric pressure at an altitude of 2438 m), and normobaric normoxia (control condition; equivalent to atmospheric conditions at ground level, circa 70 m above sea level). Comparative changes in markers of coagulation activation, fibrinolysis, platelet activation, and endothelial cell activation. Changes were observed in some hemostatic markers during the normobaric exposure, attributed to prolonged sitting and circadian variation. However, there were no significant differences between the changes in the hypobaric and the normobaric exposures. For example, the median difference in change between the hypobaric and normobaric exposure was 0 ng/mL for thrombin-antithrombin complex (95% CI, -0.30 to 0.30 ng/mL); -0.02 [corrected] nmol/L for prothrombin fragment 1 + 2 (95% CI, -0.03 to 0.01 nmol/L); 1.38 ng/mL for D-dimer (95% CI, -3.63 to 9.72 ng/mL); and -2.00% for endogenous thrombin potential (95% CI, -4.00% to 1.00%). Our findings do not support the hypothesis that hypobaric hypoxia, of the degree that might be encountered during long-haul air travel, is associated with prothrombotic alterations in the hemostatic system in healthy individuals at low risk of venous thromboembolism.

Guide to Air Cleaners in the Home

MedlinePlus

... In-duct Particle Removal Flat or panel air filters Pleated or extended surface filters In-duct Gaseous Pollutant Removal In-duct Pollutant ... can remove particles from the air — mechanical air filters and electronic air cleaners. Mechanical air filters remove ...

Considerations relative to the use of canes by blind travelers in air carrier aircraft cabins.

DOT National Transportation Integrated Search

1980-07-01

Results are presented of specific areas of study; i.e.: : 1.passenger evacuation time lapses with and without the presence of canes; : 2.emergency exiting advantages and disadvantages with and without the presence of canes; : 3.the utility of surroga...

Assessment of Aeromedical Evacuation Transport Patient Outcomes With and Without Cabin Altitude Restriction

DTIC Science & Technology

2017-08-24

reaction to stress (physical restraints) Other • Acute post-hemorrhagic anemia • Post-operative infection • Traumatic shock • Fat embolism ...decompression sickness/air gas embolism , and severe pulmonary disease [9]. The goal of this retrospective matched case-control study was to determine whether...patients who have cardiopulmonary concerns, free air in any closed cavity (e.g., skull, peritoneal cavity, injury, embolism ), or evolved gas (e.g

Measuring self-pollution in school buses using a tracer gas technique

NASA Astrophysics Data System (ADS)

Behrentz, Eduardo; Fitz, Dennis R.; Pankratz, David V.; Sabin, Lisa D.; Colome, Steven D.; Fruin, Scott A.; Winer, Arthur M.

A potentially important, but inadequately studied, source of children's exposure to pollutants during school bus commutes is the introduction of a bus's own exhaust into the passenger compartment. We developed and applied a method to determine the amount of a bus's own exhaust penetrating into the cabin in a study of six in-use school buses over a range of routes, roadway types, fuels, and emission control technologies. A tracer gas, SF 6, was metered into the bus's exhaust system using a mass flow controller whose flow rate was logged by a data acquisition system and processed with the concurrent real-time pollutant measurement data. At the same time, the SF 6 concentration inside the bus was measured using an AeroVironment CTA-1000 continuous analyzer connected to a series of solenoids that switched the sample inlet between the front and rear of the bus cabin. To account for a baseline drift of the CTA-1000, SF 6-free air was also drawn through a line located outside at the front of the bus. Although this third sample line generally provided a reference zero value, it also showed that under certain wind conditions (i.e., wind from the rear) when the bus was stopped and was idling, significant amounts of the bus's own exhaust reached this location at the front of the bus. Self-pollution, the percentage of a bus's own exhaust that can be found inside its cabin, was a function of bus type and age, and a strong function of window position (i.e., open or closed). We estimated up to 0.3% of the air inside the cabin was from the bus's own exhaust in older buses, approximately 10 times the percentage observed for newer buses, and 25% of the black carbon concentration variance was explained by the buses' self-pollution. Analysis of the tracer gas concentrations provided a powerful tool for identifying potentially high-exposure conditions.

Effect of emerging technology on a convertible, business/interceptor, supersonic-cruise jet

NASA Technical Reports Server (NTRS)

Beissner, F. L., Jr.; Lovell, W. A.; Robins, A. W.; Swanson, E. E.

1986-01-01

This study was initiated to assess the feasibility of an eight-passenger, supersonic-cruise long range business jet aircraft that could be converted into a military missile carrying interceptor. The baseline passenger version has a flight crew of two with cabin space for four rows of two passenger seats plus baggage and lavatory room in the aft cabin. The ramp weight is 61,600 pounds with an internal fuel capacity of 30,904 pounds. Utilizing an improved version of a current technology low-bypass ratio turbofan engine, range is 3,622 nautical miles at Mach 2.0 cruise and standard day operating conditions. Balanced field takeoff distance is 6,600 feet and landing distance is 5,170 feet at 44,737 pounds. The passenger section from aft of the flight crew station to the aft pressure bulkhead in the cabin was modified for the interceptor version. Bomb bay type doors were added and volume is sufficient for four advanced air-to-air missiles mounted on a rotary launcher. Missile volume was based on a Phoenix type missile with a weight of 910 pounds per missile for a total payload weight of 3,640 pounds. Structural and equipment weights were adjusted and result in a ramp weight of 63,246 pounds with a fuel load of 30,938 pounds. Based on a typical intercept mission flight profile, the resulting radius is 1,609 nautical miles at a cruise Mach number of 2.0.

Journal of Air Transportation, Volume 9, No. 2. Volume 9, No. 2

NASA Technical Reports Server (NTRS)

Bowen, Brent (Editor); Kabashkin, Igor (Editor); Gudmundsson, Sveinn Vidar (Editor); Scarpellini, Nanette (Editor)

2004-01-01

The following articles from the "Journal of Air Transportation" were processed: Future Requirements and Concepts for Cabins of Blended Wing Body Configurations:A Scenario Approach; Future Scenarios for the European Airline Industry: A Marketing-Based Perspective; An Application of the Methodology for Assessment of the Sustainability of the Air Transport System; Modeling the Effect of Enlarged Seating Room on Passenger Preferences of Domestic Airlines in Taiwan; Developing a Fleet Standardization Index for Airline Pricing; and Future Airport Capacity Utilization in Germany: Peaked Congestion and/or Idle Capacity).

An evaluation of an airline cabin safety education program for elementary school children.

PubMed

Liao, Meng-Yuan

2014-04-01

The knowledge, attitude, and behavior intentions of elementary school students about airline cabin safety before and after they took a specially designed safety education course were examined. A safety education program was designed for school-age children based on the cabin safety briefings airlines given to their passengers, as well as on lessons learned from emergency evacuations. The course is presented in three modes: a lecture, a demonstration, and then a film. A two-step survey was used for this empirical study: an illustrated multiple-choice questionnaire before the program, and, upon completion, the same questionnaire to assess its effectiveness. Before the program, there were significant differences in knowledge and attitude based on school locations and the frequency that students had traveled by air. After the course, students showed significant improvement in safety knowledge, attitude, and their behavior intention toward safety. Demographic factors, such as gender and grade, also affected the effectiveness of safety education. The study also showed that having the instructor directly interact with students by lecturing is far more effective than presenting the information using only video media. A long-term evaluation, the effectiveness of the program, using TV or video accessible on the Internet to deliver a cabin safety program, and a control group to eliminate potential extraneous factors are suggested for future studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Filter replacement lifetime prediction

DOEpatents

Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

2017-10-25

Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

Could some aviation deep vein thrombosis be a form of decompression sickness?

PubMed

Buzzacott, Peter; Mollerlokken, Andreas

2016-10-01

Aviation deep vein thrombosis is a challenge poorly understood in modern aviation. The aim of the present project was to determine if cabin decompression might favor formation of vascular bubbles in commercial air travelers. Thirty commercial flights were taken. Cabin pressure was noted at take-off and at every minute following, until the pressure stabilized. These time-pressure profiles were imported into the statistics program R and analyzed using the package SCUBA. Greatest pressure differentials between tissues and cabin pressures were estimated for 20, 40, 60, 80 and 120 min half-time compartments. Time to decompress ranged from 11 to 47 min. The greatest drop in cabin pressure was from 1022 to 776 mBar, equivalent to a saturated diver ascending from 2.46 msw depth. Mean pressure drop in flights >2 h duration was 193 mBar, while mean pressure drop in flights <2 h was 165 mBar. The greatest drop in pressure over 1 min was 28 mBar. Over 30 commercial flights it was found that the drop in cabin pressure was commensurate with that found to cause bubbles in man. Both the US Navy and the Royal Navy mandate far slower decompression from states of saturation, being 1.7 and 1.9 mBar/min respectively. The median overall rate of decompression found in this study was 8.5 mBar/min, five times the rate prescribed for USN saturation divers. The tissues associated with hypobaric bubble formation are likely slower than those associated with bounce diving, with 60 min a potentially useful index.

Effects of Cabin Upsets on Adsorption Columns for Air Revitalization

NASA Technical Reports Server (NTRS)

LeVan, M. Douglas

1999-01-01

The National Aeronautics and Space Administration (NASA) utilizes adsorption technology as part of contaminant removal systems designed for long term missions. A variety of trace contaminants can be effectively removed from gas streams by adsorption onto activated carbon. An activated carbon adsorption column meets NASA's requirements of a lightweight and efficient means of controlling trace contaminant levels aboard spacecraft and space stations. The activated carbon bed is part of the Trace Contaminant Control System (TCCS) which is utilized to purify the cabin atmosphere. TCCS designs oversize the adsorption columns to account for irregular fluctuations in cabin atmospheric conditions. Variations in the cabin atmosphere include changes in contaminant concentrations, temperature, and relative humidity. Excessively large deviations from typical conditions can result from unusual crew activity, equipment malfunctions, or even fires. The research carried out under this award focussed in detail on the effects of cabin upsets on the performance of activated carbon adsorption columns. Both experiments and modeling were performed with an emphasis on the roll of a change in relative humidity on adsorption of trace contaminants. A flow through fixed-bed apparatus was constructed at the NASA Ames Research Center, and experiments were performed there by W. Scot Appel under the direction of Dr. John E. Finn. Modeling work was performed at the University of Virginia and at Vanderbilt University by W. Scot Appel under the direction of M. Douglas LeVan. All three participants collaborated in all of the various phases of the research. The most comprehensive document describing the research is the Ph.D. dissertation of W. Scot Appel. Results have been published in several papers and presented in talks at technical conferences. All documents have been transmitted to Dr. John E. Finn.

Potential benefits of solar reflective car shells: cooler cabins, fuel savings and emission reductions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levinson, Ronnen; Pan, Heng; Ban-Weiss, George

Abstract: Vehicle thermal loads and air conditioning ancillary loads are strongly influenced by the absorption of solar energy. The adoption of solar reflective coatings for opaque surfaces of the vehicle shell can decrease the ?soak? temperature of the air in the cabin of a vehicle parked in the sun, potentially reducing the vehicle?s ancillary load and improving its fuel economy by permitting the use of a smaller air conditioner. An experimental comparison of otherwise identical black and silver compact sedans indicated that increasing the solar reflectance (?) of the car?s shell by about 0.5 lowered the soak temperature of breath-levelmore » air by about 5?6?C. Thermal analysis predicts that the air conditioning capacity required to cool the cabin air in the silver car to 25?C within 30min is 13percent less than that required in the black car. Assuming that potential reductions in AC capacity and engine ancillary load scale linearly with increase in shell solar reflectance, ADVISOR simulations of the SC03 driving cycle indicate that substituting a typical cool-colored shell (?=0.35) for a black shell (?=0.05) would reduce fuel consumption by 0.12L per 100km (1.1percent), increasing fuel economy by 0.10kmL?1 [0.24mpg] (1.1percent). It would also decrease carbon dioxide (CO2) emissions by 2.7gkm?1 (1.1percent), nitrogen oxide (NOx) emissions by 5.4mgkm?1 (0.44percent), carbon monoxide (CO) emissions by 17mgkm?1 (0.43percent), and hydrocarbon (HC) emissions by 4.1mgkm?1 (0.37percent). Selecting a typical white or silver shell (?=0.60) instead of a black shell would lower fuel consumption by 0.21L per 100km (1.9percent), raising fuel economy by 0.19kmL?1 [0.44mpg] (2.0percent). It would also decrease CO2 emissions by 4.9gkm?1 (1.9percent), NOx emissions by 9.9mgkm?1 (0.80percent), CO emissions by 31mgkm?1 (0.79percent), and HC emissions by 7.4mgkm?1 (0.67percent). Our simulations may underestimate emission reductions because emissions in standardized driving cycles are typically lower than those in real-world driving.« less

Removal of contaminant gases from an electrolytic urine pretreatment process. [in spacecraft life support systems

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Putnam, D. F.

1977-01-01

The effluent gas stream from an electrolytic urine pretreatment process was analyzed by gas chromatography-mass spectroscopy and wet chemical methods to determine its composition. The major constituents were identified as: hydrogen, carbon dioxide, oxygen, nitrogen, water vapor, and chlorine. The trace impurities were chlorinated light hydrocarbons, and a number of other organic impurities in the low ppm range. Several methods of removing all of the undesirable gases to levels acceptable for return to a space cabin atmosphere were investigated experimentally. A subsystem concept comprised of the following sequential unit processes and operations was successfully demonstrated: (1) raw urine scrubbing, (2) silica gel sorption, (3) dilution with cabin air, and (4) catalytic oxidation.

Desiccant humidity control system. [for space shuttle cabins

NASA Technical Reports Server (NTRS)

Lunde, P. J.; Kester, F. L.

1975-01-01

A water vapor and carbon dioxide sorbent material (designated HS-C) was developed for potential application to the space shuttle and tested at full scale. Capacities of two percent for carbon dioxide and four percent for water vapor were achieved using space shuttle cabin adsorption conditions and a space vacuum for desorption. Performance testing shows that water vapor can be controlled by varying the air process flow, while maintaining the ability to remove carbon dioxide. A 2000 hour life test was successfully completed, as were tests for sensitivity to cleaning solvent vapors, vibration resistance, and flammability. A system design for the space shuttle shows a 200 pound weight advantage over competitive systems and an even larger advantage for longer missions.

Monitoring of Air Quality in Passenger Cabins of the Athens Metro

NASA Astrophysics Data System (ADS)

Tsairidi, Evangelia; Assimakopoulos, Vasiliki D.; Assimakopoulos, Margarita-Niki; Barbaresos, Nicolaos; Karagiannis, Athanassios

2013-04-01

The air pollution induced by various transportation means combines the emission of pollutants with the simultaneous presence of people. In this respect, the scientific community has focused its efforts in studying both the air quality within busy streets and inside cars, buses and the underground railway network in order to identify the pollutants' sources and levels as well as the human exposure. The impact of the air pollution on commuters of the underground may be more severe because it is a confined space, extended mostly under heavily trafficked urban streets, relies on mechanical ventilation for air renewal and gathers big numbers of passengers. The purpose of the present work is to monitor the air quality of the city of Athens Metro Network cabins and platforms during the unusually hot summer of 2012. For that cause particulate matter (PM10, PM2.5, PM1), carbon dioxide (CO2), the number of commuters along with temperature (T) and humidity (RH) were recorded inside the Athens Metro Blue Line trains (covering a route from the centre of Athens (Aigaleo) to the Athens International Airport) and on the platforms of a central (Syntagma) and a suburban-traffic (Doukissis Plakentias) station between June and August. The data collection included six different experiments that took place for 2 consecutive working days each, for a time period of 6 weeks from 6:30 am too 7:00 pm in order to account for different outdoor climatic conditions and for morning and evening rush hours respectively. Measurements were taken in the middle car of the moving trains and the platform end of the selected stations. The results show PM concentrations to be higher (approximately 2 to 5 times) inside the cabins and o the platforms of the underground network as compared to the outdoor levels monitored routinely by the Ministry of Environment. Moreover, PM1, PM2.5 and PM10 average concentrations recorded at the Syntagma Station Platform were almost constantly higher reaching 11 μg m-3 47 μg m-3 and 246 μg m-3 respectively on July 11th, as opposed to the ones at Doukissis Plakentias (4 μg m-3, 15 μg m-3and 97 μg m-3 respectively). Interestingly enough, inside the trains PM1, PM2.5 and PM10 average concentrations were significantly lower compared to the Syntagma Station Platform, reaching 8 μg m-3, 27 μg m-3 and 90 μg m-3 . It was also observed that particulate levels were higher over the extent of the central part of the train route. Finally, as expected CO2 levels where found to be higher inside the trains compared to the platforms and in some cases surpassed the 1,000 ppm limit during the hottest days of the experimental campaign. Temperature and humidity remained relatively stable on the platforms whereas measurements inside the cabin fluctuated depending on the trains track locations reaching 34.8° C at the central sector of the route. KEYWORDS: Particulate pollution, Athens underground, indoor air quality, urban pollution, transportation

Disinfecting Filters For Recirculated Air

NASA Technical Reports Server (NTRS)

Pilichi, Carmine A.

1992-01-01

Simple treatment disinfects air filters by killing bacteria, algae, fungi, mycobacteria, viruses, spores, and any other micro-organisms filters might harbor. Concept applied to reusable stainless-steel wire mesh filters and disposable air filters. Treatment used on filters in air-circulation systems in spacecraft, airplanes, other vehicles, and buildings to help prevent spread of colds, sore throats, and more-serious illnesses.

AsMA Medical Guidelines for Air Travel: In-Flight Medical Care.

PubMed

Thibeault, Claude; Evans, Anthony D; Pettyjohn, Frank S; Alves, Paulo M

2015-06-01

Medical Guidelines for Airline Travel provide information that enables healthcare providers to properly advise patients who plan to travel by air. All airlines are required to provide first aid training for cabin crew, and the crew are responsible for managing any in-flight medical events. There are also regulatory requirements for the carriage of first aid and medical kits. AsMA has developed recommendations for first aid kits, emergency medical kits, and universal precaution kits.

Index to FAA Office of Aerospace Medicine Reports

DTIC Science & Technology

2011-01-01

Development and evaluation of a radar air traffic control research task. AD660198 65-32 Gogel WC, Mertens HW: Problems in depth perception: A method of...and the air traffic control specialist: Some conclusions from a decade of research . ADA093266/5 80-15 Boone JO, Van Buskirk L, Steen JA: The Federal... control applicants. ADA328998 97-18 Marcus JH: A flexible cabin simulator. ADA328996 97-19 Broach D: Designing selection tests for the future National

DoD Can Save Millions by Using Energy Efficient Centralized Aircraft Support Systems.

DTIC Science & Technology

1982-05-07

recommends that the Secretary of the Air Force: -- Reevaluate the decision not to install centralized systems at tactical bases. If the systems can be...discontinue using the aircraft’s onboard auxillary power units. These units consume tremendous amounts of jet fuel in providing cabin air-conditioning...requirements. Each command has been asked to analyze its bases to determine if centralized systems should be installed. Although a final decision has not

Pre-flight evaluation of adult patients with cystic fibrosis: a cross-sectional study.

PubMed

Edvardsen, Elisabeth; Akerø, Aina; Skjønsberg, Ole Henning; Skrede, Bjørn

2017-02-06

Air travel may imply a health hazard for patients with cystic fibrosis (CF) due to hypobaric environment in the aircraft cabin. The objective was to identify pre-flight variables, which might predict severe hypoxaemia in adult CF patients during air travel. Thirty adult CF-patients underwent pre-flight evaluation with spirometry, arterial oxygen tension (PaO 2 ), pulse oximetry (SpO 2 ) and cardiopulmonary exercise testing (CPET) at sea level (SL). The results were related to the PaO 2 obtained during a hypoxia-altitude simulation test (HAST) in which a cabin altitude of 2438 m (8000 ft) was simulated by breathing 15.1% oxygen. Four patients fulfilled the criteria for supplemental oxygen during air travel (PaO 2 HAST  < 6.6 kPa). While walking slowly during HAST, another eleven patients dropped below PaO 2 HAST 6.6 kPa. Variables obtained during CPET (PaO 2 CPET , SpO 2 CPET , minute ventilation/carbon dioxide output, maximal oxygen uptake) showed the strongest correlation to PaO 2 HAST . Exercise testing might be of value for predicting in-flight hypoxaemia and thus the need for supplemental oxygen during air travel in CF patients. Trial registration The study is retrospectively listed in the ClinicalTrials.gov Protocol Registration System: NCT01569880 (date; 30/3/2012).

Normobaric hypoxia inhalation test vs. response to airline flight in healthy passengers.

PubMed

Kelly, Paul T; Swanney, Maureen P; Frampton, Chris; Seccombe, Leigh M; Peters, Matthew J; Beckert, Lutz E

2006-11-01

There is little data available to determine the normal response to normobaric hypoxia inhalation testing (NHIT) and air travel. Quantifying a healthy response may assist in the evaluation of passengers considered at risk for air travel. The aims of this study were: (1) to quantify the degree of desaturation in healthy subjects during a NHIT and air travel; and (2) assess the validity of the NHIT when compared with actual in-flight responses. There were 15 healthy adults (age 23-57; 10 women) who volunteered for this study. Preflight tests included lung function, arterial blood gas, pulse oximetry (SpO2), and NHIT (inspired oxygen 15%). SpO2 and cabin pressure were measured continuously on each subject during a commercial air flight (mean cabin altitude 2178 m; range 1719-2426 m). In-flight oxygenation was compared with the preflight NHIT. Lung function testing results were normal. There was significant desaturation (SpO2) during the NHIT (pre: 98 +/- 2%; post: 92 +/- 2%) and at cruising altitude (pre: 97 +/- 1%; cruise: 92 +/- 2%). There was no difference between the final NHIT SpO2 and the mean in-flight SpO2. There was a significant difference between the lowest in-flight SpO2 (88 +/- 2%) vs. the lowest NHIT SpO2, (90 +/- 2%). Oxygen saturation decreases significantly during air travel in normal individuals. In this group of healthy passengers the NHIT approximates some, but not all, aspects of in-flight oxygenation. These results can be used to describe a normal response to the NHIT and air-travel.

Soft-X-Ray-Enhanced Electrostatic Precipitation for Protection against Inhalable Allergens, Ultrafine Particles, and Microbial Infections

PubMed Central

Kettleson, Eric M.; Schriewer, Jill M.; Buller, R. Mark L.

2013-01-01

Protection of the human lung from infectious agents, allergens, and ultrafine particles is difficult with current technologies. High-efficiency particulate air (HEPA) filters remove airborne particles of >0.3 μm with 99.97% efficiency, but they are expensive to maintain. Electrostatic precipitation has been used as an inexpensive approach to remove large particles from airflows, but it has a collection efficiency minimum in the submicrometer size range, allowing for a penetration window for some allergens and ultrafine particles. Incorporating soft X-ray irradiation as an in situ component of the electrostatic precipitation process greatly improves capture efficiency of ultrafine particles. Here we demonstrate the removal and inactivation capabilities of soft-X-ray-enhanced electrostatic precipitation technology targeting infectious agents (Bacillus anthracis, Mycobacterium bovis BCG, and poxviruses), allergens, and ultrafine particles. Incorporation of in situ soft X-ray irradiation at low-intensity corona conditions resulted in (i) 2-fold to 9-fold increase in capture efficiency of 200- to 600-nm particles and (ii) a considerable delay in the mean day of death as well as lower overall mortality rates in ectromelia virus (ECTV) cohorts. At the high-intensity corona conditions, nearly complete protection from viral and bacterial respiratory infection was afforded to the murine models for all biological agents tested. When optimized for combined efficient particle removal with limited ozone production, this technology could be incorporated into stand-alone indoor air cleaners or scaled for installation in aircraft cabin, office, and residential heating, ventilating, and air-conditioning (HVAC) systems. PMID:23263945

Soft-X-ray-enhanced electrostatic precipitation for protection against inhalable allergens, ultrafine particles, and microbial infections.

PubMed

Kettleson, Eric M; Schriewer, Jill M; Buller, R Mark L; Biswas, Pratim

2013-02-01

Protection of the human lung from infectious agents, allergens, and ultrafine particles is difficult with current technologies. High-efficiency particulate air (HEPA) filters remove airborne particles of >0.3 μm with 99.97% efficiency, but they are expensive to maintain. Electrostatic precipitation has been used as an inexpensive approach to remove large particles from airflows, but it has a collection efficiency minimum in the submicrometer size range, allowing for a penetration window for some allergens and ultrafine particles. Incorporating soft X-ray irradiation as an in situ component of the electrostatic precipitation process greatly improves capture efficiency of ultrafine particles. Here we demonstrate the removal and inactivation capabilities of soft-X-ray-enhanced electrostatic precipitation technology targeting infectious agents (Bacillus anthracis, Mycobacterium bovis BCG, and poxviruses), allergens, and ultrafine particles. Incorporation of in situ soft X-ray irradiation at low-intensity corona conditions resulted in (i) 2-fold to 9-fold increase in capture efficiency of 200- to 600-nm particles and (ii) a considerable delay in the mean day of death as well as lower overall mortality rates in ectromelia virus (ECTV) cohorts. At the high-intensity corona conditions, nearly complete protection from viral and bacterial respiratory infection was afforded to the murine models for all biological agents tested. When optimized for combined efficient particle removal with limited ozone production, this technology could be incorporated into stand-alone indoor air cleaners or scaled for installation in aircraft cabin, office, and residential heating, ventilating, and air-conditioning (HVAC) systems.

Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

PubMed

Möritz, M; Peters, H; Nipko, B; Rüden, H

2001-07-01

The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry (< 80% R. H.) and warm (> 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

Regenerable Air Purification System for Gas-Phase Contaminant Control

NASA Technical Reports Server (NTRS)

Constantinescu, Ileana C.; Finn, John E.; LeVan, M. Douglas; Lung, Bernadette (Technical Monitor)

2000-01-01

Tests of a pre-prototype regenerable air purification system (RAPS) that uses water vapor to displace adsorbed contaminants from an adsorbent column have been performed at NASA Ames Research Center. A unit based on this design can be used for removing trace gas-phase contaminants from spacecraft cabin air or from polluted process streams including incinerator exhaust. During the normal operation mode, contaminants are removed from the air on the column. Regeneration of the column is performed on-line. During regeneration, contaminants are displaced and destroyed inside the closed oxidation loop. In this presentation we discuss initial experimental results for the performance of RAPS in the removal and treatment of several important spacecraft contaminant species from air.

Remotely serviced filter and housing

DOEpatents

Ross, M.J.; Zaladonis, L.A.

1987-07-22

A filter system for a hot cell comprises a housing adapted for input of air or other gas to be filtered, flow of the air through a filter element, and exit of filtered air. The housing is tapered at the top to make it easy to insert a filter cartridge holds the filter element while the air or other gas is passed through the filter element. Captive bolts in trunnion nuts are readily operated by electromechanical manipulators operating power wrenches to secure and release the filter cartridge. The filter cartridge is adapted to make it easy to change a filter element by using a master-slave manipulator at a shielded window station. 6 figs.

Remotely serviced filter and housing

DOEpatents

Ross, Maurice J.; Zaladonis, Larry A.

1988-09-27

A filter system for a hot cell comprises a housing adapted for input of air or other gas to be filtered, flow of the air through a filter element, and exit of filtered air. The housing is tapered at the top to make it easy to insert a filter cartridge using an overhead crane. The filter cartridge holds the filter element while the air or other gas is passed through the filter element. Captive bolts in trunnion nuts are readily operated by electromechanical manipulators operating power wrenches to secure and release the filter cartridge. The filter cartridge is adapted to make it easy to change a filter element by using a master-slave manipulator at a shielded window station.

Inhalation toxicology. III., Evaluation of thermal degradation products from aircraft and automobile engine oils, aircraft hydraulic fluid, and mineral oil.

DOT National Transportation Integrated Search

1983-04-01

A malfunctioning seal in the gear-reduction box of a turboprop aircraft engine could allow oil to enter the turbine's compressor section, which is the source of bleed air used to pressurize the cabin. Oil, or its degradation products, could have a de...

14 CFR 382.123 - What are the requirements concerning priority cabin stowage for wheelchairs and other assistive...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false What are the requirements concerning... Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL REGULATIONS NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Stowage of Wheelchairs, Other Mobility Aids, and Other...

14 CFR 382.123 - What are the requirements concerning priority cabin stowage for wheelchairs and other assistive...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false What are the requirements concerning... Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL REGULATIONS NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Stowage of Wheelchairs, Other Mobility Aids, and Other...

14 CFR 382.123 - What are the requirements concerning priority cabin stowage for wheelchairs and other assistive...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false What are the requirements concerning... Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL REGULATIONS NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Stowage of Wheelchairs, Other Mobility Aids, and Other...

14 CFR 382.123 - What are the requirements concerning priority cabin stowage for wheelchairs and other assistive...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false What are the requirements concerning... Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL REGULATIONS NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Stowage of Wheelchairs, Other Mobility Aids, and Other...

14 CFR 382.123 - What are the requirements concerning priority cabin stowage for wheelchairs and other assistive...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false What are the requirements concerning... Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL REGULATIONS NONDISCRIMINATION ON THE BASIS OF DISABILITY IN AIR TRAVEL Stowage of Wheelchairs, Other Mobility Aids, and Other...

Noise levels in a neonatal transport incubator in medically configured aircraft.

PubMed

Sittig, Steven E; Nesbitt, Jeffrey C; Krageschmidt, Dale A; Sobczak, Steven C; Johnson, Robert V

2011-01-01

The purpose of this study was to evaluate exposure of neonates to noise during air medical transport as few commercially available hearing protective devices exist for premature newborns during air medical transport. Sound pressure levels in an infant incubator during actual flight conditions in four common medically configured aircraft were measured. Three noise dosimeters measured time-weighted average noise exposure during flight in each aircraft. One dosimeter was placed in the infant incubator, and the remaining dosimeters recorded noise levels in various parts of the aircraft cabin. The incubator provided a 6-dBA decrease in noise exposure from that in the crew cabin. The average noise level in the incubator in all aircraft was close to 80 dB, much higher than the proposed limits of 45 dB for neonatal intensive care unit noise exposure or 60 dB during transport. Exposure of neonates to elevated noise levels during transport may be harmful, and steps should be taken to protect the hearing of this patient population. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, K.A.; Burchell, T.D.; Judkins, R.R.

1998-10-27

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply air stream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium. 3 figs.

ARRANGEMENT FOR REPLACING FILTERS

DOEpatents

Blomgren, R.A.; Bohlin, N.J.C.

1957-08-27

An improved filtered air exhaust system which may be continually operated during the replacement of the filters without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like filter containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the filters are pushed is normal to the exhaust air duct. A number of unused filters are in line behind the filters in use, and are moved by a hydraulic ram so that a fresh filter is positioned in the air duct. The used filter is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated filter without interruption to the normal flow of exhaust air.

Visualization of the air flow behind the automotive benchmark vent

NASA Astrophysics Data System (ADS)

Pech, Ondrej; Jedelsky, Jan; Caletka, Petr; Jicha, Miroslav

2015-05-01

Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive vents and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark vent. The visualization was made for two different shapes of the inlet channel connected to the benchmark vent. The smoke visualization with the laser knife was used. The influence of the shape of the inlet channel to the airflow direction, its enlargement and position of air flow axis were investigated.

AsMA Medical Guidelines for Air Travel: Fitness to Fly and Medical Clearances.

PubMed

Thibeault, Claude; Evans, Anthony D; Dowdall, Nigel P

2015-07-01

Medical Guidelines for Airline Travel provide information that enables healthcare providers to properly advise patients who plan to travel by air. Not everyone is fit to travel by air and physicians should advise their patients accordingly. They should review the passenger's medical condition, giving special consideration to the dosage and timing of any medications, contagiousness, and the need for special assistance during travel. In general, an individual with an unstable medical condition should not fly; cabin altitude, duration of exposure, and altitude of the destination airport are all considerations when recommending a passenger for flight.

Effectiveness of in-room air filtration and dilution ventilation for tuberculosis infection control.

PubMed

Miller-Leiden, S; Lobascio, C; Nazaroff, W W; Macher, J M

1996-09-01

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.

Effectiveness of In-Room Air Filtration and Dilution Ventilation for Tuberculosis Infection Control.

PubMed

Miller-Leiden, S; Lohascio, C; Nazaroff, W W; Macher, J M

1996-09-01

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.

Phosphorylation and ubiquitination-dependent degradation of CABIN1 releases p53 for transactivation upon genotoxic stress.

PubMed

Choi, Soo-Youn; Jang, Hyonchol; Roe, Jae-Seok; Kim, Seong-Tae; Cho, Eun-Jung; Youn, Hong-Duk

2013-02-01

CABIN1 acts as a negative regulator of p53 by keeping p53 in an inactive state on chromatin. Genotoxic stress causes rapid dissociation of CABIN1 and activation of p53. However, its molecular mechanism is still unknown. Here, we reveal the phosphorylation- and ubiquitination-dependent degradation of CABIN1 upon DNA damage, releasing p53 for transcriptional activation. The DNA-damage-signaling kinases, ATM and CHK2, phosphorylate CABIN1 and increase the degradation of CABIN1 protein. Knockdown or overexpression of these kinases influences the stability of CABIN1 protein showing that their activity is critical for degradation of CABIN1. Additionally, CABIN1 was found to undergo ubiquitin-dependent proteasomal degradation mediated by the CRL4DDB2 ubiquitin ligase complex. Both phosphorylation and ubiquitination of CABIN1 appear to be relevant for controlling the level of CABIN1 protein upon genotoxic stress.

Transparent air filter for high-efficiency PM2.5 capture.

PubMed

Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

2015-02-16

Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m(-3)). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

Transparent air filter for high-efficiency PM2.5 capture

NASA Astrophysics Data System (ADS)

Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

2015-02-01

Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m-3). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

Adsorption and Processes in Spacecraft Environmental Control and Life Support Systems

NASA Technical Reports Server (NTRS)

Dall-Bauman, Liese; Finn, John E.; Kliss, Mark (Technical Monitor)

1997-01-01

The environmental control and life support system on a spacecraft must maintain a safe and comfortable environment in which the crew can live and work. The system's functions include supplying the crew with oxygen and water, as well as removing carbon dioxide, water vapor, and trace contaminants from cabin air. Although open-loop systems have been used in the past, logistics and safety factors of current and future missions in space make near-complete recycling of the cabin's air and water desirable. The recycling process may include separation and reduction of carbon dioxide, removal of trace gas-phase contaminants, recovery and purification of humidity condensate, purification and polishing of wastewater streams, and other processes. Several of these operations can be performed totally or in part by adsorption processes. Adsorption processes are frequently good candidates for separation and purification in space by virtue of such characteristics as gravity independence, high reliability, relatively high energy efficiency, design flexibility, technological maturity, and regenerability. For these reasons, adsorption has historically played a key role in life support on U.S. and Russian piloted spacecraft. This article focuses on three current spacecraft life support applications that often use adsorption technology: carbon dioxide separation from cabin air, gas-phase trace contaminant control, and potable water recovery from waste streams. In each application, adsorption technology has been selected for use on the International Space Station. The requirements, science, and hardware for each application are discussed. Eventually, human space exploration may lead to construction of planetary habitats. These habitats may have additional applications, such as control of greenhouse gas composition and purification of hydroponic solutions, and may have different requirements and resources available to them, such as gases present in the planetary atmosphere. Adsorption separation and purification processes may continue to fulfill environmental control and life support needs well into the future.

Adsorption Processes in Spacecraft Environmental Control and Life Support Systems

NASA Technical Reports Server (NTRS)

Bauman, Liese Dall; Finn, John E.; Kliss, Mark (Technical Monitor)

1998-01-01

The environmental control and life support system on a spacecraft must maintain a safe and comfortable environment in which the crew can live and work. The system's functions include supplying the crew with oxygen and water as well as removing carbon dioxide, water vapor, and trace contaminants from cabin air. Although open-loop systems have been used in the past, logistics and safety factors of current and future missions in space make near-complete recycling of the cabin's air and water imperative. The recycling process may include separation and reduction of carbon dioxide, removal of trace gas-phase contaminants, recovery and purification of humidity condensate, purification and polishing of wastewater streams, and other processes. Several of these operations can be performed totally or in part by adsorption processes. These processes are frequently good candidates to perform separations and purifications in space due to their gravity independence, high reliability, relatively high energy efficiency, design flexibility, technological maturity, and regenerability. For these reasons, adsorption has historically played a key role in life support on U.S. and Russian piloted spacecraft. This article focuses on three current spacecraft life support applications that often use adsorption technology: gas-phase trace contaminant control, carbon dioxide removal from cabin air, and potable water recovery from waste streams. In each application, adsorption technology has been selected for use on the International Space Station. The requirements, science, and hardware for each of these applications are discussed. Eventually, human space exploration may lead to construction of planetary habitats. These habitats may provide additional opportunities for use of adsorption processes, such as control of greenhouse gas composition, and may have different requirements and resources available to them, such as gases present in the planetary atmosphere. Adsorption separation and purification processes can be expected to continue to fulfill environmental control and life support needs on future missions.

Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics

NASA Technical Reports Server (NTRS)

Ahearn, D. G.; Crow, S. A.; Simmons, R. B.; Price, D. L.; Mishra, S. K.; Pierson, D. L.

1997-01-01

Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics.

PubMed

Ahearn, D G; Crow, S A; Simmons, R B; Price, D L; Mishra, S K; Pierson, D L

1997-11-01

Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

USAF bioenvironmental noise data handbook. Volume 166: AF/M32T-1 tester, pressurized cabin leakage, aircraft

NASA Astrophysics Data System (ADS)

Rau, T. H.

1982-07-01

Measured and extrapolated data define the bioacoustic environments produced by a gasoline engine driven cabin leakage tester operating outdoors on a concrete apron at normal rated conditions. Near field data are presented for 37 locations at a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference level, perceived noise level, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors. Far-field data measured at 36 locations are normalized to standard meteorological conditions and extrapolated from 10 - 1600 meters to derive sets of equal-value contours for these same seven acoustic measures as functions of angle and distance from the source.

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners.

PubMed

Batterman, S; Du, L; Mentz, G; Mukherjee, B; Parker, E; Godwin, C; Chin, J-Y; O'Toole, A; Robins, T; Rowe, Z; Lewis, T

2012-06-01

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. Environmental tobacco smoke (ETS) increased particulate matter (PM) levels by about 14 μg/m3 and was often detected using ETS-specific tracers despite restrictions on smoking in the house as reported on questionnaires administered to caregivers. PM concentrations depended on season, filter usage, relative humidity, air exchange ratios, number of children, outdoor PM levels, sweeping/dusting, and presence of a central air conditioner (AC). Free-standing air filters can be an effective intervention that provides substantial reductions in PM concentrations if the filters are used. However, filter use was variable across the study population and declined over the study duration, and thus strategies are needed to encourage and maintain use of filters. The variability in filter use suggests that exposure misclassification is a potential problem in intervention studies using filters. The installation of a room AC in the bedroom, intended to limit air exchange ratios, along with an air filter, did not lower PM levels more than the filter alone. © 2011 John Wiley & Sons A/S.

Filter for on-line air monitor unaffected by radon progeny and method of using same

DOEpatents

Phillips, Terrance D.; Edwards, Howard D.

1999-01-01

An apparatus for testing air having contaminants and radon progeny therein. The apparatus includes a sampling box having an inlet for receiving the air and an outlet for discharging the air. The sampling box includes a filter made of a plate of sintered stainless steel. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough. A method of testing air having contaminants and radon progeny therein. The method includes providing a testing apparatus that has a sampling box with an inlet for receiving the air and an outlet for discharging the air, and has a sintered stainless steel filter disposed within said sampling box; drawing air from a source into the sampling box using a vacuum pump; passing the air through the filter; monitoring the contaminants trapped by the filter; and providing an alarm when a selected level of contaminants is reached. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough.

Analysis of debris from Spacelab Space Life Sciences-1

NASA Astrophysics Data System (ADS)

Caruso, S. V.; Rodgers, E. B.; Huff, T. L.

1992-07-01

Airborne microbiological and particulate contamination generated aboard Spacelab modules is a potential safety hazard. In order to shed light on the characteristics of these contaminants, microbial and chemical/particulate analyses were performed on debris vacuumed from cabin and avionics air filters in the Space Life Sciences-1 (SLS-1) module of the Space Transportation System 40 (STS-40) mission 1 month after landing. The debris was sorted into categories (e.g., metal, nonmetal, hair/fur, synthetic fibers, food particles, insect fragments, etc.). Elemental analysis of particles was done by energy dispersive analysis of x rays (metals) and Fourier transform infrared spectroscopy (nonmetals). Scanning electron micrographs were done of most particles. Microbiological samples were grown on R2A culture medium and identified. Clothing fibers dominated the debris by volume. Other particles, all attributed to the crew, resulted from abrasions and impacts during missions operations (e.g., paint chips, plastic, electronic scraps and clothing fibers). All bacterial species identified are commonly found in the atmosphere or on the human body. Bacillus sp. was the most frequently seen bacterium. One of the bacterial species, Enterobacter agglomerans, could cause illness in crew members with depressed immune systems.

Analysis of debris from Spacelab Space Life Sciences-1

NASA Technical Reports Server (NTRS)

Caruso, S. V.; Rodgers, E. B.; Huff, T. L.

1992-01-01

Airborne microbiological and particulate contamination generated aboard Spacelab modules is a potential safety hazard. In order to shed light on the characteristics of these contaminants, microbial and chemical/particulate analyses were performed on debris vacuumed from cabin and avionics air filters in the Space Life Sciences-1 (SLS-1) module of the Space Transportation System 40 (STS-40) mission 1 month after landing. The debris was sorted into categories (e.g., metal, nonmetal, hair/fur, synthetic fibers, food particles, insect fragments, etc.). Elemental analysis of particles was done by energy dispersive analysis of x rays (metals) and Fourier transform infrared spectroscopy (nonmetals). Scanning electron micrographs were done of most particles. Microbiological samples were grown on R2A culture medium and identified. Clothing fibers dominated the debris by volume. Other particles, all attributed to the crew, resulted from abrasions and impacts during missions operations (e.g., paint chips, plastic, electronic scraps and clothing fibers). All bacterial species identified are commonly found in the atmosphere or on the human body. Bacillus sp. was the most frequently seen bacterium. One of the bacterial species, Enterobacter agglomerans, could cause illness in crew members with depressed immune systems.

Impact of the air filtration on indoor particle concentration by using combination filters in offices building

NASA Astrophysics Data System (ADS)

Kabrein, H.; Hariri, A.; Leman, A. M.; Noraini, N. M. R.; Yusof, M. Z. M.; Afandi, A.

2017-09-01

Heating ventilation and air conditioning system (HVAC) is very important for offices building and human health. The combining filter method was used to reduce the air pollution indoor such as that particulate matter and gases pollution that affected in health and productivity. Using particle filters in industrial HVAC systems (factories and manufacturing process) does not enough to remove all the indoor pollution. The main objective of this study is to investigate the impact of combination filters for particle and gases removal efficiency. The combining method is by using two filters (particulate filter pre-filter and carbon filter) to reduce particle matter and gases respectively. The purpose of this study is to use minimum efficiency reporting value (MERV filter) rating 13 and activated carbon filter (ACF) to remove indoor air pollution and controlling the air change rate to enhance the air quality and energy saving. It was concluded that the combination filter showed good removal efficiency of particle up to 90.76% and 89.25% for PM10 and PM2.5 respectively. The pressure drop across the filters was small compared with the high-efficiency filters. The filtration efficiency of combination filters after three months’ was better than efficiency by the new MERV filter alone.

Managing patients with stable respiratory disease planning air travel: a primary care summary of the British Thoracic Society recommendations.

PubMed

Josephs, Lynn K; Coker, Robina K; Thomas, Mike

2013-06-01

Air travel poses medical challenges to passengers with respiratory disease, principally because of exposure to a hypobaric environment. In 2002 the British Thoracic Society published recommendations for adults and children with respiratory disease planning air travel, with a web update in 2004. New full recommendations and a summary were published in 2011, containing key recommendations for the assessment of high-risk patients and identification of those likely to require in-flight supplemental oxygen. This paper highlights the aspects of particular relevance to primary care practitioners with the following key points: (1) At cabin altitudes of 8000 feet (the usual upper limit of in-flight cabin pressure, equivalent to 0.75 atmospheres) the partial pressure of oxygen falls to the equivalent of breathing 15.1% oxygen at sea level. Arterial oxygen tension falls in all passengers; in patients with respiratory disease, altitude may worsen preexisting hypoxaemia. (2) Altitude exposure also influences the volume of any air in cavities, where pressure x volume remain constant (Boyle's law), so that a pneumothorax or closed lung bulla will expand and may cause respiratory distress. Similarly, barotrauma may affect the middle ear or sinuses if these cavities fail to equilibrate. (3) Patients with respiratory disease require clinical assessment and advice before air travel to: (a) optimise usual care; (b) consider contraindications to travel and possible need for in-flight oxygen; (c) consider the need for secondary care referral for further assessment; (d) discuss the risk of venous thromboembolism; and (e) discuss forward planning for the journey.

78 FR 46315 - Foreign-Trade Zone (FTZ) 247-Erie, Pennsylvania, Notification of Proposed Production Activity, GE...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

...; cover assemblies; strainer assemblies; oil filter assemblies; air filter assemblies; screen assemblies; filter assemblies; breather assemblies; filter box assemblies; sand trap assemblies; valve stems; brake... holders; staples; rivets; brazing alloys; diesel engines; frame assemblies; air inlets; filter box air...

2. WILLIAM ELLIOT CABIN AND OUTBULIDING, CABIN WEST REAR AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. WILLIAM ELLIOT CABIN AND OUTBULIDING, CABIN WEST REAR AND NORTH SIDES, OUTBULIDING WEST FRONT AND NORTH SIDE - Liberty Historic District, William Elliot Cabin, Route 2, Cle Elum, Liberty, Kittitas County, WA

1. WILLIAM ELLIOT CABIN AND OUTBUILDING, CABIN EAST FRONT AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. WILLIAM ELLIOT CABIN AND OUTBUILDING, CABIN EAST FRONT AND SOUTH SIDE, OUTBUILDING EAST REAR AND SOUTH SIDES - Liberty Historic District, William Elliot Cabin, Route 2, Cle Elum, Liberty, Kittitas County, WA

Impact data from a transport aircraft during a controlled impact demonstration

NASA Technical Reports Server (NTRS)

Fasanella, E. L.; Alfaro-Bou, E.; Hayduk, R. J.

1986-01-01

On December 1, 1984, the FAA and NASA conducted a remotely piloted air-to-ground crash test of a Boeing 720 transport aircraft instrumented to measure crash loads of the structure and the anthropomorphic dummy passengers. Over 330 time histories of accelerations and loads collected during the Full-Scale Transport Controlled Impact Demonstration (CID) for the 1-sec period after initial impact are presented. Although a symmetric 1 deg. nose-up attitude with a 17 ft/sec sink rate was planned, the plane was yawed and rolled 13 deg. at initial (left-wing) impact. The first fuselage impact occurred near the nose wheel well with the nose pitched down 2.5 deg. Peak normal (vertical) floor accelerations were highest in the cockpit and forward cabin near the nose wheel well and were approximately 14G. The remaining cabin floor received normal acceleration peaks of 7G or less. The peak longitudinal floor accelerations showed a similar distribution, with the highest (7G) in the cockpit and forward cabin, decreasing to 4G or less toward the rear. Peak transverse floor accelerations ranged from about 5G in the cockpit to 1G in the aft fuselage.

True Measures

ERIC Educational Resources Information Center

Cox, Ron

2010-01-01

Air filters perform an important function in commercial and institutional facilities. Because indoor air typically is two to five times more polluted than outdoor air, air filters are needed to remove respirable particles such as microorganisms, dust and allergens from the breathing air. In fact, air filters provide the primary defense for…

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

CF6 jet engine performance improvement program. Task 1: Feasibility analysis

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1979-01-01

Technical and economic engine improvement concepts selected for subsequent development include: (1) fan improvement; (2) short core exhaust; (3) HP turbine aerodynamic improvement; (4) HP turbine roundness control; (5) HP turbine active clearance control; and (6) cabin air recirculation. The fuel savings for the selected engine modification concepts for the CF6 fleet are estimated.

76 FR 52899 - Airworthiness Directives; The Boeing Company Model 767-200, -300, and -300F Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-24

... the compliance times specified, unless already done. Installation of New Relay and Wiring Bundle (g... certain wiring changes, installing a new relay and necessary wiring in the cabin air conditioning and... for changing the wire bundle route and wiring, installing a new relay and applicable wiring in the...

Catalyst Substrates Remove Contaminants, Produce Fuel

NASA Technical Reports Server (NTRS)

2012-01-01

A spacecraft is the ultimate tight building. We don t want any leaks, and there is very little fresh air coming in, says Jay Perry, an aerospace engineer at Marshall Space Flight Center. As a result, there is a huge potential for a buildup of contaminants from a host of sources. Inside a spacecraft, contaminants can be introduced from the materials that make spacecraft components, electronics boxes, or activities by the crew such as food preparation or cleaning. Humans also generate contaminants by breathing and through the body s natural metabolic processes. As part of the sophisticated Environmental Control and Life Support System on the International Space Station (ISS), a trace contaminant control system removes carbon dioxide and other impurities from the cabin atmosphere. To maintain healthy levels, the system uses adsorbent media to filter chemical contaminant molecules and a high-temperature catalytic oxidizer to change the chemical structure of the contaminants to something more benign, usually carbon dioxide and water. In the 1990s, while researching air quality control technology for extended spaceflight travel, Perry and others at Marshall were looking for a regenerable process for the continuous removal of carbon dioxide and trace chemical contaminants on long-duration manned space flights. At the time, the existing technology used on U.S. spacecraft could only be used once, which meant that a spacecraft had to carry additional spare parts for use in case the first one was depleted, or the spacecraft would have to return to Earth to exchange the components.

Design and Performance of the Sorbent-Based Atmosphere Revitalization System for Orion

NASA Technical Reports Server (NTRS)

Ritter, James A.; Reynolds, Steven P.; Ebner, Armin D.; Knox, James C.; LeVan, M. Douglas

2007-01-01

Validation and simulations of a real-time dynamic cabin model were conducted on the sorbent-based atmosphere revitalization system for Orion. The dynamic cabin model, which updates the concentration of H2O and CO2 every second during the simulation, was able to predict the steady state model values for H2O and CO2 for long periods of steady metabolic production for a 4-person crew. It also showed similar trends for the exercise periods, where there were quick changes in production rates. Once validated, the cabin model was used to determine the effects of feed flow rate, cabin volume and column volume. A higher feed flow rate reduced the cabin concentrations only slightly over the base case, a larger cabin volume was able to reduce the cabin concentrations even further, and the lower column volume led to much higher cabin concentrations. Finally, the cabin model was used to determine the effect of the amount of silica gel in the column. As the amount increased, the cabin concentration of H2O decreased, but the cabin concentration of CO2 increased.

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

UV Disinfection System for Cabin Air

NASA Astrophysics Data System (ADS)

Lim, Soojung

Ultraviolet (UV) radiation is commonly used for disinfection of water. As a result of advancements made in the last 10-15 years, the analysis and design of UV disinfection systems for water is well developed. UV disinfection is also used for disinfection of air; however, despite the fact the UV-air systems have a longer record of application than UV-water systems, the methods used to analyze and design UV-air disinfection systems remain quite empirical. It is well-established that the effectiveness of UV-air systems is strongly affected by the type of microorganisms, the irradiation level/type (lamp power and wavelength), duration of irradiation (exposure time), air movement pattern (mixing degree), and relative humidity. This paper will describe ongoing efforts to evaluate, design and test a UV-air system based on first principles. Specific issues to be addressed in this work will include laboratory measurements of relevant kinetics (i.e., UV dose-response behavior) and numerical simulations designed to represent fluid mechanics and the radiation intensity field. UV dose-response behavior of test microorganism was measured using a laboratory (bench-scale) system. Target microorganisms (e.g., bacterial spores) were first applied to membrane filters at sub-monolayer coverage. The filters were then transferred to an environmental chamber at fixed relative humidity (RH) and allowed to equilibrate with their surroundings. Microorganisms were then subjected to UV exposure under a collimated beam. The experiment was repeated at RH values ranging from 20% to 100%. UV dose-response behavior was observed to vary with RH. For example, at 100% RH, a UV dose of 20 mJ/cm2 accomplished 90% (1 log10 units) of the B. subtilis spore inactivation, whereas 99 % (2 log10 units) inactivation was accomplished at this same UV dose under 20% RH conditions. However, at higher doses, the result was opposite of that in low dose. Reactor behavior is simulated using an integrated application of computational fluid dynamics (CFD) and radiation intensity field models. These simulations followed a Lagrangian approach, wherein the UV radiation intensity field was mapped onto simulated particle trajectories for prediction of the UV dose delivered to each particle. By repeating these calculations for a large number of simulated particle trajectories, an estimate of the UV dose distribution delivered by the reactor can be made. In turn, these dose distribution estimates are integrated with the UV dose-response behavior described above to yield an estimate of microbial inactivation accomplished by the reactor. This modeling approach has the advantage of allowing simulation of many reactor configurations in a relatively short period of time. Moreover, by following this approach of "numerical prototyping," it is possible to "build" and analyze several virtual reactors before the construction of a physical prototype. As such, this procedure allows effective development of efficient reactors.

Protein-Based Nanofabrics for Multifunctional Air Filtering

NASA Astrophysics Data System (ADS)

Souzandeh, Hamid

With the fast development of economics and population, air pollution is getting worse and becomes a great concern worldwide. The release of chemicals, particulates and biological materials into air can lead to various diseases or discomfort to humans and other living organisms, alongside other serious impacts on the environment. Therefore, improving indoor air quality using various air filters is in critical need because people stay inside buildings most time of the day. However, current air filters using traditional polymers can only remove particles from the polluted air and disposing the huge amount of used air filters can cause serious secondary environmental pollution. Therefore, development of multi-functional air filter materials with environmental friendliness is significant. For this purpose, we developed "green" protein-based multifunctional air-filtering materials. The outstanding performance of the green materials in removal of multiple species of pollutants, including particulate matter, toxic chemicals, and biological hazards, simultaneously, will greatly facilitate the development of the next-generation air-filtration systems. First and foremost, we developed high-performance protein-based nanofabric air-filter mats. It was found that the protein-nanofabrics possess high-efficiency multifunctional air-filtering properties for both particles and various species of chemical gases. Then, the high-performance natural protein-based nanofabrics were promoted both mechanically and functionally by a textured cellulose paper towel. It is interestingly discovered that the textured cellulose paper towel not only can act as a flexible mechanical support, but also a type of airflow regulator which can improve the pollutant-nanofilter interactions. Furthermore, the protein-based nanofabrics were crosslinked in order to enhance the environmental-stability of the filters. It was found that the crosslinked protein-nanofabrics can significantly improve the structure stability against different moisture levels and temperatures, while maintain the multifunctional filtration performance. Moreover, it was demonstrated that the crosslinked protein-nanomaterials also possess antibacterial properties against the selected gram-negative and gram-positive bacteria. This provides a cost-effective solution for advanced "green" nanomaterials with excellent performance in both filtration functions and structure stability under varying environment. This work indicates that protein-based air-filters are promising "green" air-filtering materials for next-generation air-filtration systems.

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, Kirk A.; Burchell, Timothy D.; Judkins, Roddie R.

1998-01-01

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply airstream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium.

Achieving 'excellent' indoor air quality in commercial offices equipped with air-handling unit--respirable suspended particulate.

PubMed

Lam, K S; Chan, F S; Fung, W Y; Lui, B S S; Lau, L W L

2006-04-01

A study was carried out to investigate the feasibility of achieving ultra low respirable suspended particulates (RSP) in commercial offices without major modification of existing ventilation systems by enhancing the particulates removal efficiency of existing central ventilation systems. Four types of filters which include pre-filters, cartridge filters, bag filters and high efficiency particulates air (HEPA) filters were tested in a commercial building in Causeway Bay. The results show that an RSP objective of <20 microg/m3 could be met by removing RSP from both the return air and outdoor air supply simultaneously. This level of performance is classed as 'excellent' by the Hong Kong Government, Environmental Protection Department. Filters with efficiency that exceed 80% placed both in the return air and outdoor air were sufficient to meet the objective. It is not necessary to install HEPA filters to achieve the 'excellent' class. The outdoor air filter has great influence on the steady state indoor RSP concentration while the effective cleaning rate is governed by the return air filter. Higher efficiency filters increased the static drop but the volume flow of the air fan was not affected significantly. The additional cost incurred was <5% of the existing operation cost. This paper reports a field study of RSP control for an indoor office environment. The results are directly applicable to building service engineering in the design of ventilation systems using air-handling units. Field observations indicated that indoor RSP in an office environment could be suppressed below 20 microg/m3 within 1 h by the simultaneous filtration of outdoor air and return air. Outdoor air filtration has a great influence on the steady state indoor concentration and return air filtration governs the cleaning rate. It is believed that the results of this study could be extended to the cleaning of other indoor pollutants such as volatile organic compounds.

Aeromedical evacuation of the seriously ill.

PubMed Central

Oxer, H F

1975-01-01

Almost any patient may be carried by air, but air transport introduces some special problems owing to the effects of altitude, noise, turbulence, and the special environment. Because of these factors it is important to know when considering a patient's suitability for air transport the type of aircraft to be used, the flight profile--its duration and expected cabin altitudes--and the facilities available on board. It is essential to carry all equipment (as simple and as portable as possible), drugs, and diets that may be needed, and to be sure that all the skills and nursing help needed to deal with any possible problems are available. PMID:1182455

Spacelab 3 mission

NASA Technical Reports Server (NTRS)

Dalton, Bonnie P.

1990-01-01

Spacelab-3 (SL-3) was the first microgravity mission of extended duration involving crew interaction with animal experiments. This interaction involved sharing the Spacelab environmental system, changing animal food, and changing animal waste trays by the crew. Extensive microbial testing was conducted on the animal specimens and crew and on their ground and flight facilities during all phases of the mission to determine the potential for cross contamination. Macroparticulate sampling was attempted but was unsuccessful due to the unforseen particulate contamination occurring during the flight. Particulate debris of varying size (250 micron to several inches) and composition was recovered post flight from the Spacelab floor, end cones, overhead areas, avionics fan filter, cabin fan filters, tunnel adaptor, and from the crew module. These data are discussed along with solutions, which were implemented, for particulate and microbial containment for future flight facilities.

78 FR 16604 - Airworthiness Directives; Diamond Aircraft Industries GmbH Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

... unsafe condition as the engine air inlet filter is subject to icing. We are issuing this AD to require... warmer air conditions. The subsequent investigation identified that the engine air inlet filter is... with a manually controlled alternate air valve which bypasses the inlet air filter and provides...

Preparation of Fiber Based Binder Materials to Enhance the Gas Adsorption Efficiency of Carbon Air Filter.

PubMed

Lim, Tae Hwan; Choi, Jeong Rak; Lim, Dae Young; Lee, So Hee; Yeo, Sang Young

2015-10-01

Fiber binder adapted carbon air filter is prepared to increase gas adsorption efficiency and environmental stability. The filter prevents harmful gases, as well as particle dusts in the air from entering the body when a human inhales. The basic structure of carbon air filter is composed of spunbond/meltblown/activated carbon/bottom substrate. Activated carbons and meltblown layer are adapted to increase gas adsorption and dust filtration efficiency, respectively. Liquid type adhesive is used in the conventional carbon air filter as a binder material between activated carbons and other layers. However, it is thought that the liquid binder is not an ideal material with respect to its bonding strength and liquid flow behavior that reduce gas adsorption efficiency. To overcome these disadvantages, fiber type binder is introduced in our study. It is confirmed that fiber type binder adapted air filter media show higher strip strength, and their gas adsorption efficiencies are measured over 42% during 60 sec. These values are higher than those of conventional filter. Although the differential pressure of fiber binder adapted air filter is relatively high compared to the conventional one, short fibers have a good potential as a binder materials of activated carbon based air filter.

Influence of a controlled environment simulating an in-flight airplane cabin on dry eye disease.

PubMed

Tesón, Marisa; González-García, María J; López-Miguel, Alberto; Enríquez-de-Salamanca, Amalia; Martín-Montañez, Vicente; Benito, María Jesús; Mateo, María Eugenia; Stern, Michael E; Calonge, Margarita

2013-03-01

To evaluate symptoms, signs, and the levels of 16 tears inflammatory mediators of dry eye (DE) patients exposed to an environment simulating an in-flight air cabin in an environmental chamber. Twenty DE patients were exposed to controlled environment simulating an in-flight airplane cabin (simulated in-flight condition [SIC]) of 23°C, 5% relative humidity, localized air flow, and 750 millibars (mb) of barometric pressure. As controls, 15 DE patients were subjected to a simulated standard condition (SSC) of 23°C, 45% relative humidity, and 930 mb. A DE symptoms questionnaire, diagnostic tests, and determination of 16 tear molecules by multiplex bead array were performed before and 2 hours after exposure. After SIC exposure, DE patients became more symptomatic, suffered a significant (P ≤ 0.05) decrease in tear stability (tear break up time) (from 2.18 ± 0.28 to 1.53 ± 0.20), and tear volume (phenol red thread test), and a significant (P ≤ 0.05) increase in corneal staining, both globally (0.50 ± 0.14 before and 1.25 ± 0.19 after) and in each area (Baylor scale). After SSC, DE patients only showed a mild, but significant (P ≤ 0.05), increase in central and inferior corneal staining. Consistently, tear levels of IL-6 and matrix metalloproteinase (MMP)-9 significantly increased and tear epidermal growth factor (EGF) significantly decreased (P ≤ 0.05) only after SIC. The controlled adverse environment conditions in this environmental chamber can simulate the conditions in which DE patients might be exposed during flight. As this clearly impaired their lacrimal functional unit, it would be advisable that DE patients use therapeutic strategies capable of ameliorating these adverse episodes.

Virtual Design of a Four-Bed Molecular Sieve for Exploration

NASA Technical Reports Server (NTRS)

Giesy, T. J.; Coker, R. F.; O'Connor, B. F.; Knox, J. C.

2017-01-01

Aboard the International Space Station, CO2 is removed from the cabin atmosphere by a four-bed molecular sieve (4BMS) process called the Carbon Dioxide Removal Assembly (CDRA).1 This 4BMS process operates by passing the CO2-laden air through a desiccant bed to remove any humidity and then passing the dried air through a sorbent bed to remove the CO2. While one pair of beds is in use, the other pair is thermally regenerated to allow for continuous CO2 removal.

14 CFR 25.832 - Cabin ozone concentration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Cabin ozone concentration. 25.832 Section... Cabin ozone concentration. (a) The airplane cabin ozone concentration during flight must be shown not to... demonstrate that either— (1) The airplane cannot be operated at an altitude which would result in cabin ozone...

14 CFR 25.832 - Cabin ozone concentration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cabin ozone concentration. 25.832 Section... Cabin ozone concentration. (a) The airplane cabin ozone concentration during flight must be shown not to... demonstrate that either— (1) The airplane cannot be operated at an altitude which would result in cabin ozone...

14 CFR 25.832 - Cabin ozone concentration.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Cabin ozone concentration. 25.832 Section... Cabin ozone concentration. (a) The airplane cabin ozone concentration during flight must be shown not to... demonstrate that either— (1) The airplane cannot be operated at an altitude which would result in cabin ozone...

14 CFR 25.832 - Cabin ozone concentration.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cabin ozone concentration. 25.832 Section... Cabin ozone concentration. (a) The airplane cabin ozone concentration during flight must be shown not to... demonstrate that either— (1) The airplane cannot be operated at an altitude which would result in cabin ozone...

14 CFR 25.832 - Cabin ozone concentration.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Cabin ozone concentration. 25.832 Section... Cabin ozone concentration. (a) The airplane cabin ozone concentration during flight must be shown not to... demonstrate that either— (1) The airplane cannot be operated at an altitude which would result in cabin ozone...

14 CFR 23.841 - Pressurized cabins.

Code of Federal Regulations, 2013 CFR

2013-01-01

... emergency procedure. A 17-second flight crew recognition and reaction time must be applied between cabin... pressurization system must prevent the cabin altitude from exceeding the cabin altitude-time history shown in... exceeds 25,000 feet, the maximum time the cabin altitude may exceed 25,000 feet is 2 minutes; time...

14 CFR 23.841 - Pressurized cabins.

Code of Federal Regulations, 2014 CFR

2014-01-01

... emergency procedure. A 17-second flight crew recognition and reaction time must be applied between cabin... pressurization system must prevent the cabin altitude from exceeding the cabin altitude-time history shown in... exceeds 25,000 feet, the maximum time the cabin altitude may exceed 25,000 feet is 2 minutes; time...

International Space Station Carbon Dioxide Removal Assembly (ISS CDRA) Concepts and Advancements

NASA Technical Reports Server (NTRS)

ElSherif, Dina; Knox, James C.

2005-01-01

An important aspect of air revitalization for life support in spacecraft is the removal of carbon dioxide from cabin air. Several types of carbon dioxide removal systems are in use in spacecraft life support. These systems rely on various removal techniques that employ different architectures and media for scrubbing CO2, such as permeable membranes, liquid amine, adsorbents, and absorbents. Sorbent systems have been used since the first manned missions. The current state of key technology is the existing International Space Station (ISS) Carbon Dioxide Removal Assembly (CDRA), a system that selectively removes carbon dioxide from the cabin atmosphere. The CDRA system was launched aboard UF-2 in February 2001 and resides in the U.S. Destiny Laboratory module. During the past four years, the CDRA system has operated with varying degrees of success. There have been several approaches to troubleshooting the CDRA system aimed at developing work-around solutions that would minimize the impact on astronaut time required to implement interim solutions. The paper discusses some of the short-term fixes applied to promote hardware life and restore functionality, as well as long-term plans and solutions for improving operability and reliability. The CDRA is a critical piece of life support equipment in the air revitalization system of the ISS, and is demonstrated technology that may ultimately prove well-suited for use in lunar or Mars base, and Mars transit life support applications.

Natural Air Purifier

NASA Technical Reports Server (NTRS)

1993-01-01

NASA environmental research has led to a plant-based air filtering system. Dr. B.C. Wolverton, a former NASA engineer who developed a biological filtering system for space life support, served as a consultant to Terra Firma Environmental. The company is marketing the BioFilter, a natural air purifier that combines activated carbon and other filter media with living plants and microorganisms. The filter material traps and holds indoor pollutants; plant roots and microorganisms then convert the pollutants into food for the plant. Most non-flowering house plants will work. After pollutants have been removed, the cleansed air is returned to the room through slits in the planter. Terra Firma is currently developing a filter that will also disinfect the air.

Wildfire Smoke

MedlinePlus

... keep the fresh-air intake closed and the filter clean to prevent outdoor smoke from getting inside. ... inside with the windows closed. Use an air filter . Use a freestanding indoor air filter with particle ...

Efficiency of different air filter types for pig facilities at laboratory scale

PubMed Central

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Truyen, Uwe

2017-01-01

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove aerosol containing equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), bovine enterovirus 1 (BEV), Actinobacillus pleuropneumoniae (APP), and Staphylococcus (S.) aureus from air. Depending on the filter prototype and utilisation, the airflow was set at 1,800 m3/h (combination of upstream prefilter and fiberglass filter) or 80 m3/h (filter mat). The pathogens were aerosolized and their concentration was determined in front of and behind the filter by culture or quantitative real-time RT-PCR. Furthermore, survival of the pathogens over time in the filter material was determined. Bacteria were most efficiently filtered with a reduction rate of up to 99.9% depending on the filter used. An approximately 98% reduction was achieved for the viruses tested. Viability or infectivity of APP or PRRSV in the filter material decreased below the detection limit after 4 h and 24 h, respectively, whereas S. aureus was still culturable after 4 weeks. Our results demonstrate that pathogens can efficiently be reduced by air filtration. Consequently, air filtration combined with other strict biosecurity measures markedly reduces the risk of introducing airborne transmitted pathogens to animal facilities. In addition, air filtration might be useful in reducing bioaerosols within a pig barn, hence improving respiratory health of pigs. PMID:29028843

Efficiency of different air filter types for pig facilities at laboratory scale.

PubMed

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Truyen, Uwe; Speck, Stephanie

2017-01-01

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove aerosol containing equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), bovine enterovirus 1 (BEV), Actinobacillus pleuropneumoniae (APP), and Staphylococcus (S.) aureus from air. Depending on the filter prototype and utilisation, the airflow was set at 1,800 m3/h (combination of upstream prefilter and fiberglass filter) or 80 m3/h (filter mat). The pathogens were aerosolized and their concentration was determined in front of and behind the filter by culture or quantitative real-time RT-PCR. Furthermore, survival of the pathogens over time in the filter material was determined. Bacteria were most efficiently filtered with a reduction rate of up to 99.9% depending on the filter used. An approximately 98% reduction was achieved for the viruses tested. Viability or infectivity of APP or PRRSV in the filter material decreased below the detection limit after 4 h and 24 h, respectively, whereas S. aureus was still culturable after 4 weeks. Our results demonstrate that pathogens can efficiently be reduced by air filtration. Consequently, air filtration combined with other strict biosecurity measures markedly reduces the risk of introducing airborne transmitted pathogens to animal facilities. In addition, air filtration might be useful in reducing bioaerosols within a pig barn, hence improving respiratory health of pigs.

Concentric Split Flow Filter

NASA Technical Reports Server (NTRS)

Stapleton, Thomas J. (Inventor)

2015-01-01

A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

Recirculating electric air filter

DOEpatents

Bergman, Werner

1986-01-01

An electric air filter cartridge has a cylindrical inner high voltage eleode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

Recirculating electric air filter

DOEpatents

Bergman, W.

1985-01-09

An electric air filter cartridge has a cylindrical inner high voltage electrode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

78 FR 46358 - Extension of Agency Information Collection Activity Under OMB Review: Security Programs for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

.... Specifically, TSA requires foreign air carriers to submit the following information: (1) A master crew list of all flight and cabin crew members flying to and from the United States; (2) the flight crew list on a..., 49 CFR part 1546. TSA uses the information collected to determine compliance with 49 CFR part 1546...

The Impact of Emerging Technologies on Future Air Capabilities

DTIC Science & Technology

1999-12-01

ferroelectric FPAs (60). More advanced FPA technologies include quantum well IR photodetectors ( QWIPS ) and strained layer superlattices. Significant...microspacecraft. Expected benefits include enhanced handling qualities, vibration suppression, alleviation of noise and vibration and monitoring of vehicle...of fatigue loads, cabin vibration and both internal and external noise , as well as contributing to enhanced handling. This would result in better

Impact of measurable physical phenomena on contact thermal comfort

NASA Astrophysics Data System (ADS)

Fojtlín, Miloš; Pokorný, Jan; Fišer, Jan; Toma, Róbert; Tuhovčák, Ján

Cabin HVAC (Heating Ventilation and Air-conditioning) systems have become an essential part of personal vehicles as demands for comfortable transport are still rising. In fact, 85 % of the car trips in Europe are shorter than 18 km and last only up to 30 minutes. Under such conditions, the HVAC unit cannot often ensure desired cabin environment and passengers are prone to experience thermal stress. For this reason, additional comfort systems, such as heated or ventilated seats, are available on the market. However, there is no straightforward method to evaluate thermal comfort at the contact surfaces nowadays. The aim of this work is to summarise information about heated and ventilated seats. These technologies use electrical heating and fan driven air to contact area in order to achieve enhanced comfort. It is also expected, that such measures may contribute to lower energy consumption. Yet, in real conditions it is almost impossible to measure the airflow through the ventilated seat directly. Therefore, there is a need for an approach that would correlate measurable physical phenomena with thermal comfort. For this reason, a method that exploits a measurement of temperatures and humidity at the contact area is proposed. Preliminary results that correlate comfort with measurable physical phenomena are demonstrated.

14 CFR 125.113 - Cabin interiors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Cabin interiors. 125.113 Section 125.113....113 Cabin interiors. (a) Upon the first major overhaul of an airplane cabin or refurbishing of the cabin interior, all materials in each compartment used by the crew or passengers that do not meet the...

Allergy-Proof Your House

MedlinePlus

... small-particle or high-efficiency particulate air (HEPA) filter. Shampoo the carpet frequently. Curtains and blinds. Use ... dander they shed. Air filtration. Choose an air filter that has a small-particle or HEPA filter. ...

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners

PubMed Central

Batterman, S.; Du, L.; Mentz, G.; Mukherjee, B.; Parker, E.; Godwin, C.; Chin, J.-Y.; O'Toole, A.; Robins, T.; Rowe, Z.; Lewis, T.

2014-01-01

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84 ± 27%, but dropped to 63 ± 33% in subsequent seasons. In months when households were not visited, use averaged only 34 ± 30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. PMID:22145709

Aeromedical transport: its hidden problems.

PubMed Central

Parsons, C. J.; Bobechko, W. P.

1982-01-01

Air transport can move patients safely and rapidly over long distances. However, changes in altitude can have disastrous effects because diminished ambient air pressure may allow gases in closed spaces and tissues to expand rapidly. Even pressurized commercial aircraft do not maintain sea-level pressure: cabin pressures equal to those at yp to 8000 ft may be experienced, diminishing oxygen tension in proportion. Air transport is absolutely contraindicated for patients with untreated pneumothorax, gas gangrene, or air trapped in the cranium and those who have recently undergone abdominal surgery. Special considerations including a planned low-altitude flight are warrented for patients who are anemic, in respiratory or cardiac distress, or immobilized in casts, or who have been engaged in underwater diving immediately before the flight. Images FIG. 1 PMID:7059899

Improving indoor air quality and thermal comfort in office building by using combination filters

NASA Astrophysics Data System (ADS)

Kabrein, H.; Yusof, M. Z. M.; Hariri, A.; Leman, A. M.; Afandi, A.

2017-09-01

Poor indoor air quality and thermal comfort condition in the workspace affected the occupants’ health and work productivity, especially when adapting the recirculation of air in heating ventilation and air-conditioning (HVAC) system. The recirculation of air was implemented in this study by mixing the circulated returned indoor air with the outdoor fresh air. The aims of this study are to assess the indoor thermal comfort and indoor air quality (IAQ) in the office buildings, equipped with combination filters. The air filtration technique consisting minimum efficiency reporting value (MERV) filter and activated carbon fiber (ACF) filter, located before the fan coil units. The findings of the study show that the technique of mixing recirculation air with the fresh air through the combination filters met the recommended thermal comfort condition in the workspace. Furthermore, the result of the post-occupancy evaluation (POE) and the environmental measurements comply with the ASHRAE 55 standard. In addition, the level of CO2 concentration continued to decrease during the period of the measurement.

Experimental investigation of air pressure affecting filtration performance of fibrous filter sheet.

PubMed

Xu, Bin; Yu, Xiao; Wu, Ya; Lin, Zhongping

2017-03-01

Understanding the effect of air pressure on their filtration performance is important for assessing the effectiveness of fibrous filters under different practical circumstances. The effectiveness of three classes of air filter sheets were investigated in laboratory-based measurements at a wide range of air pressures (60-130 KPa). The filtration efficiency was found most sensitive to the air pressure change at smaller particle sizes. As the air pressure increased from 60 to 130 KPa, significant decrease in filtration efficiency (up to 15%) and increase in pressure drop (up to 90 Pa) were observed. The filtration efficiency of the filter sheet with largest fiber diameter and smallest solid volume fraction was affected most, while the pressure drop of the filter sheet with smallest fiber diameter and largest solid volume fraction was affected most. The effect of air pressure on the filtration efficiency was slightly larger at greater filter face air velocity. However, the effect of air pressure on the pressure drop was negligible. The filtration efficiency and pressure drop were explicitly expressed as functions of the air pressure. Two coefficients were empirically derived and successfully accounted for the effects of air pressure on filtration efficiency and pressure drop.

Fungal colonization of air filters for use in heating, ventilating, and air conditioning (HVAC) systems.

PubMed

Simmons, R B; Crow, S A

1995-01-01

New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55-99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.

Use of Whatman-41 filters in air quality sampling networks (with applications to elemental analysis)

NASA Technical Reports Server (NTRS)

Neustadter, H. E.; Sidik, S. M.; King, R. B.; Fordyce, J. S.; Burr, J. C.

1974-01-01

The operation of a 16-site parallel high volume air sampling network with glass fiber filters on one unit and Whatman-41 filters on the other is reported. The network data and data from several other experiments indicate that (1) Sampler-to-sampler and filter-to-filter variabilities are small; (2) hygroscopic affinity of Whatman-41 filters need not introduce errors; and (3) suspended particulate samples from glass fiber filters averaged slightly, but not statistically significantly, higher than from Whatman-41-filters. The results obtained demonstrate the practicability of Whatman-41 filters for air quality monitoring and elemental analysis.

Assessing Aircraft Supply Air to Recommend Compounds for Timely Warning of Contamination

NASA Astrophysics Data System (ADS)

Fox, Richard B.

Taking aircraft out of service for even one day to correct fume-in-cabin events can cost the industry roughly $630 million per year in lost revenue. The quantitative correlation study investigated quantitative relationships between measured concentrations of contaminants in bleed air and probability of odor detectability. Data were collected from 94 aircraft engine and auxiliary power unit (APU) bleed air tests from an archival data set between 1997 and 2011, and no relationships were found. Pearson correlation was followed by regression analysis for individual contaminants. Significant relationships of concentrations of compounds in bleed air to probability of odor detectability were found (p<0.05), as well as between compound concentration and probability of sensory irritancy detectability. Study results may be useful to establish early warning levels. Predictive trend monitoring, a method to identify potential pending failure modes within a mechanical system, may influence scheduled down-time for maintenance as a planned event, rather than repair after a mechanical failure and thereby reduce operational costs associated with odor-in-cabin events. Twenty compounds (independent variables) were found statistically significant as related to probability of odor detectability (dependent variable 1). Seventeen compounds (independent variables) were found statistically significant as related to probability of sensory irritancy detectability (dependent variable 2). Additional research was recommended to further investigate relationships between concentrations of contaminants and probability of odor detectability or probability of sensory irritancy detectability for all turbine oil brands. Further research on implementation of predictive trend monitoring may be warranted to demonstrate how the monitoring process might be applied to in-flight application.

Air filtration in the free molecular flow regime: a review of high-efficiency particulate air filters based on carbon nanotubes.

PubMed

Li, Peng; Wang, Chunya; Zhang, Yingying; Wei, Fei

2014-11-01

Air filtration in the free molecular flow (FMF) regime is important and challenging because a higher filtration efficiency and lower pressure drop are obtained when the fiber diameter is smaller than the gas mean free path in the FMF regime. In previous studies, FMF conditions have been obtained by increasing the gas mean free path through reducing the pressure and increasing the temperature. In the case of carbon nanotubes (CNTs) with nanoscale diameters, it is possible to filtrate in the FMF regime under normal conditions. This paper reviews recent progress in theoretical and experimental studies of air filtration in the FMF regime. Typical structure models of high-efficiency particulate (HEPA) air filters based on CNTs are introduced. The pressure drop in air filters operated in the FMF regime is less than that predicted by the conventional air filtration theory. The thinnest HEPA filters fabricated from single-walled CNT films have an extremely low pressure drop. CNT air filters with a gradient nanostructure are shown to give a much better filtration performance in dynamic filtration. CNT air filters with a hierarchical structure and an agglomerated CNT fluidized bed air filter are also introduced. Finally, the challenges and opportunities for the application of CNTs in air filtration are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Skin surface hydration decreases rapidly during long distance flights.

PubMed

Guéhenneux, Sabine; Gardinier, Sophie; Morizot, Frederique; Le Fur, Isabelle; Tschachler, Erwin

2012-05-01

Dehydration of the stratum corneum leads to sensations and symptoms of 'dry skin' such as skin tightness and itchiness. As these complaints are frequently experienced by airline travellers, the aim of this study was to investigate the changes in skin surface hydration during long distance flights. The study was performed on four healthy Caucasian, and on four Japanese women aged 29-39 years, travelling on long distance flights. They had stopped using skin care products at least 12 h before, and did not apply them during the flights. The air temperature and relative humidity inside the cabin, as well as skin capacitance of the face and forearm of participants, were registered at several time points before and during the flights. Relative humidity of the aircraft cabin dropped to levels below 10% within 2 h after take-off and stayed at this value throughout the flight. Skin capacitance decreased rapidly on both the face and forearms with most pronounced changes on the cheeks where it decreased by up to 37%. Our results demonstrate that during long distance flights, the aircraft cabin environment leads to a rapid decrease in stratum corneum hydration, an alteration, which probably accounts for the discomfort experienced by long distance aircraft travellers. © 2011 John Wiley & Sons A/S.

Pressure Effects on the Self-Extinguishment Limits of Aerospace Materials

NASA Technical Reports Server (NTRS)

Hirsch, David B.; Williams, James H.; Haas, Jon P.; Beeson, Harold D.; Ruff, Gary A.; Pedley, Michael D.

2009-01-01

The Orion Crew Exploration Vehicle Module (CM) is being designed to operate in an atmosphere of up to 30% oxygen at a pressure of 10.2 psia for lunar missions. Spacecraft materials selection is based on an upward flammability test conducted in a closed chamber under the worst expected conditions of pressure and oxygen concentration. Material flammability depends on both oxygen concentration and pressure but, since oxygen concentration is the primary driver, all materials are certified in the 30% oxygen, 10.2 psia environment. Extensive data exist from the Shuttle Program at this condition which used relatively the same test methodology as currently used in the Constellation Program. When the CM returns to Earth, a snorkel device will be activated after splashdown to provide outside air to the crew; however, for operational reasons, it is desirable to maximize the time the crew is able to breathe cabin air before the snorkel device is activated. To maximize this time, it has been proposed to raise the partial pressure of oxygen in the CM immediately before reentry while maintaining the total cabin pressure at 14.7 psia. In addition, it has been proposed to leak-test the Orion CM with ambient air at a maximum pressure of 17.3 psia. No data exist to assess how high the cabin oxygen concentration can be at 14.7 psia or 17.3 psia. One is to re-test a large number of materials at these pressures at a significant cost. However, since the maximum oxygen concentration (MOC) at which a material will self-extinguish has been determined for a variety of spacecraft materials as a function of pressure, a second alternative is to use existing data to estimate the MOC at 14.7 psia and 17.3 psia. This data will be examined in this paper and an analysis presented to determine the oxygen concentrations at the increased pressures that will result in self-extinguishment of a material. This analysis showed that the oxygen concentration for the Orion CM at 14.7 psia cannot be set higher than 25.6% without potentially invalidating the materials flammability certification in 30% oxygen at 10.2 psia for some materials. Materials certified under these conditions would still be self-extinguishing in ambient air at 17.3 psia. alternative

Directly measured cabin pressure conditions during Boeing 747-400 commercial aircraft flights.

PubMed

Kelly, Paul T; Seccombe, Leigh M; Rogers, Peter G; Peters, Matthew J

2007-07-01

In the low pressure environment of commercial aircraft, hypoxaemia may be common and accentuated in patients with lung or heart disease. Regulations specify a cabin pressure not lower than 750 hPa but it is not known whether this standard is met. This knowledge is important in determining the hazards of commercial flight for patients and the validity of current flight simulation tests. Using a wrist-watch recording altimeter, cabin pressure was recorded at 60 s intervals on 45 flights in Boeing 747-400 aircraft with three airlines. A log was kept of aircraft altitude using the in-flight display. Change in cabin pressure during flight, relationship between aircraft altitude and cabin pressure and proportion of flight time with cabin pressure approaching the minimum specified by regulation were determined. Flight duration averaged 10 h. Average cabin pressure during flight was 846 hPa. There was a linear fall in cabin pressure as the aircraft cruising altitude increased. At 10,300 m (34,000 ft) cabin pressure was 843 hPa and changed 8 hPa for every 300 m (1000 ft) change in aircraft altitude (r(2) = 0.993; P < 0.001). Lowest cabin pressure was 792 hPa at 12 200 m (40,000 ft) but during only 2% of flight time was cabin pressure less than 800 hPa. Cabin pressure is determined only by the engineering of the aircraft and its altitude and in the present study was always higher than required by regulation. Current fitness-to-fly evaluations simulate cabin conditions that passengers will not experience on these aircraft. There may be increased risks to patients should new or older aircraft operate nearer to the present minimum standard.

Cabin fire simulator lavatory tests

NASA Technical Reports Server (NTRS)

Schutter, K. J.; Klinck, D. M.

1980-01-01

All tests were conducted in the Douglas Cabin Fire Simulator under in-flight ventilation conditions. All tests were allowed to continue for a period of one hour. Data obtained during these tests included: heat flux and temperatures of the lavatory; cabin temperature variations; gas analyses for O2, CO2, CO, HF, HC1, and HCN; respiration and electrocardiogram data on instrumented animal subjects (rats) exposed in the cabin; and color motion pictures. All tests resulted in a survivable cabin condition; however, occupants of the cabin would have been subjected to noxious fumes.

NASA Lunar Dust Filtration and Separations Workshop Report

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Stocker, Dennis P.

2009-01-01

NASA Glenn Research Center hosted a 2.5-day workshop, entitled "NASA Lunar Dust Filtration and Separations Workshop" at the Ohio Aerospace Institute in Cleveland, Ohio, on November 18 to 20, 2008. The purpose of the workshop was to address the issues and challenges of particulate matter removal from the cabin atmospheres in the Altair lunar lander, lunar habitats, and in pressurized rovers. The presence of lunar regolith dust inside the pressurized volumes was a theme of particular interest. The workshop provided an opportunity for NASA, industry experts, and academia to identify and discuss the capabilities of current and developing air and gas particulate matter filtration and separations technologies as they may apply to NASA s needs. A goal of the workshop was to provide recommendations for strategic research areas in cabin atmospheric particulate matter removal and disposal technologies that will advance and/or supplement the baseline approach for these future lunar surface exploration missions.

IMAX camera in payload bay

NASA Image and Video Library

1995-12-20

STS074-361-035 (12-20 Nov 1995) --- This medium close-up view centers on the IMAX Cargo Bay Camera (ICBC) and its associated IMAX Camera Container Equipment (ICCE) at its position in the cargo bay of the Earth-orbiting Space Shuttle Atlantis. With its own ?space suit? or protective covering to protect it from the rigors of space, this version of the IMAX was able to record scenes not accessible with the in-cabin cameras. For docking and undocking activities involving Russia?s Mir Space Station and the Space Shuttle Atlantis, the camera joined a variety of in-cabin camera hardware in recording the historical events. IMAX?s secondary objectives were to film Earth views. The IMAX project is a collaboration between NASA, the Smithsonian Institution?s National Air and Space Museum (NASM), IMAX Systems Corporation, and the Lockheed Corporation to document significant space activities and promote NASA?s educational goals using the IMAX film medium.

NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0014

NASA Technical Reports Server (NTRS)

Briehl, D.; Dudzinski, T. J.; Liu, D. C.

1980-01-01

The data currently available from GASP, including flight routes and dates, instrumentation, data processing procedures, and data tape specifications are described. Measurements of atmospheric ozone, cabin ozine, carbon monoxide, water vapor, particles, clouds, condensation nuclei, filter samples and related meteorological and flight information obtained during 562 flights of aircraft N533PA, N4711U, N655PA, and VH-EBE from October 3, 1977 through January 5, 1978 are reported. Data representing tropopause pressures obtained from time and space interpolation of National Meteorological Center archived data for the dates of the flights are included.

Forensic aspects of the aerotoxic syndrome.

PubMed

Abeyratne, Ruwantissa

2002-01-01

Three decades ago, cabin air quality was seemingly not an issue in commercial aviation and the incidence of disease through air borne vectors or toxic fumes was uncommon among passengers and crew. However, it is claimed that modern day jet airliners generally carry the threat of disease through the ventilator systems of these aircraft which are designed for optimum efficiency, leaving them exposed to lapses in the recycling of clean air and blocking fumes from engine exhausts of the jets from entering the inhabited parts of the aircraft. It has been claimed that aerotoxic fumes are most common in the cockpit, and that the technical crew are the most susceptible to the aerotoxic syndrome.

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2013 CFR

2013-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2011 CFR

2011-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2014 CFR

2014-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2012 CFR

2012-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2010 CFR

2010-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

Evaluating fungal populations by genera/species on wide body commercial passenger aircraft and in airport terminals.

PubMed

McKernan, Lauralynn Taylor; Burge, Harriet; Wallingford, Kenneth M; Hein, Misty J; Herrick, Robert

2007-04-01

Given the potential health effects of fungi and the amount of time aircrew and passengers spend inside aircraft, it is important to study fungal populations in the aircraft environment. Research objectives included documenting the genera/species of airborne culturable fungal concentrations and total spore concentrations on a twin-aisle wide body commercial passenger aircraft. Twelve flights between 4.5 and 6.5 h in duration on Boeing 767 (B-767) aircraft were evaluated. Two air cooling packs and 50% recirculation rate (i.e. 50:50 mix of outside air and filtered inside air) were utilized during flight operations. Passenger occupancy rates varied from 67 to 100%. N-6 impactors and total spore traps were used to collect sequential, triplicate air samples in the front and rear of coach class during six sampling intervals throughout each flight: boarding, mid-climb, early cruise, mid-cruise, late cruise and deplaning. Comparison air samples were also collected inside and outside the airport terminals at the origin and destination cities resulting in a total of 522 culturable and 517 total spore samples. A total of 45 surface wipe samples were collected using swabs onboard the aircraft and inside the airport terminals. A variety of taxa were observed in the culturable and total spore samples. A frequency analysis of the fungal data indicated that Cladosporium, Aspergillus and Penicillium were predominant genera in the culturable samples whereas Cladosporium, Basidiospores and Penicillium/Aspergillus were predominant in the total spore samples. Fungal populations observed inside the aircraft were comprised of similar genera, detected significantly less frequently and with lower mean concentrations than those observed in typical office buildings. Although sources internal to the aircraft could not be ruled out, our data demonstrate the importance of passenger activity as the source of the fungi observed on aircraft. Isolated fungal peak events occurred occasionally when concentrations of a particular genus or species rose sharply inside the cabin for a limited period. Overall, our research demonstrates that on the sampled flights the B-767 filtration system operated efficiently to remove fungal spores when two air cooling packs and 50% recirculation rate were utilized during flight operations.

Expedition 28 Crew Members during IFM

NASA Image and Video Library

2011-06-30

ISS028-E-010781 (30 June 2011) --- NASA astronauts Mike Fossum (left) and Ron Garan, both Expedition 28 flight engineers, perform in-flight maintenance in the Harmony node of the International Space Station. The maintenance involved removing and replacing the failed Common Cabin Air Assembly (CCAA) heat exchanger in the P3 Midbay with a new spare Heat Exchanger Orbit Replaceable Unit (HX ORU) and lines.

58. View of Writer's Cabin (or Three Pines Cabin) and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

58. View of Writer's Cabin (or Three Pines Cabin) and path looking from the southeast (similar to HALS no. LA-1-35) - Briarwood: The Caroline Dormon Nature Preserve, 216 Caroline Dormon Road, Saline, Bienville Parish, LA

Evaluation of a commercial air filter for removal of viruses from the air.

PubMed

Roelants, P; Boon, B; Lhoest, W

1968-10-01

The effectiveness of a commercial absolute air filter for removal of viruses from air was tested with an actinophage, under the usual conditions of a laminar airflow clean room. A new method of dry phage dispersion is described. The filter showed an average reduction of 99.996% of airborne actinophage.

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2011 CFR

2011-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2013 CFR

2013-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2012 CFR

2012-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2014 CFR

2014-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

Cancer incidence among male military and civil pilots and flight attendants: an analysis on published data.

PubMed

Buja, Alessandra; Lange, John H; Perissinotto, Egle; Rausa, Giuseppe; Grigoletto, Francesco; Canova, Cristina; Mastrangelo, Giuseppe

2005-11-01

Flight personnel are exposed to cosmic ionizing radiation, chemicals (fuel, jet engine exhausts, cabin air pollutants), electromagnetic fields from cockpit instruments, and disrupted sleep patterns. Only recently has cancer risk among these workers been investigated. With the aim of increasing the precision of risk estimates of cancer incidence, follow-up studies reporting a standardized incidence ratio for cancer among male flight attendants, civil and military pilots were obtained from online databases and analysed. A meta-analysis was performed by applying a random effect model, obtaining a meta-standardized incidence ratio (SIR), and 95% confidence interval (CI). In male cabin attendants, and civil and military pilots, meta-SIRs were 3.42 (CI = 1.94-6.06), 2.18 (1.69-2.80), 1.43 (1.09-1.87) for melanoma; and 7.46 (3.52-15.89), 1.88 (1.23-2.88), 1.80 (1.25-2.58) for other skin cancer, respectively. These tumors share as risk factors, ionizing radiation, recreational sun exposure and socioeconomic status. The meta-SIRs are not adjusted for confounding; the magnitude of risk for melanoma decreased when we corrected for socioeconomic status. In civil pilots, meta-SIR was 1.47 (1.06-2.05) for prostate cancer. Age (civil pilots are older than military pilots and cabin attendants) and disrupted sleep pattern (entailing hyposecretion of melatonin, which has been reported to suppress proliferative effects of androgen on prostate cancer cells) might be involved. In male cabin attendants, meta-SIR was 21.5 (2.25-205.8) for Kaposi's sarcoma and 2.49 (1.03-6.03) for non-Hodgkin's lymphoma. AIDS, which was the most frequent single cause of death in this occupational category, likely explains the excess of the latter two tumors.

Development and testing of a portable wind sensitive directional air sampler

NASA Technical Reports Server (NTRS)

Deyo, J.; Toma, J.; King, R. B.

1975-01-01

A portable wind sensitive directional air sampler was developed as part of an air pollution source identification system. The system is designed to identify sources of air pollution based on the directional collection of field air samples and their analysis for TSP and trace element characteristics. Sources can be identified by analyzing the data on the basis of pattern recognition concepts. The unit, designated Air Scout, receives wind direction signals from an associated wind vane. Air samples are collected on filter slides using a standard high volume air sampler drawing air through a porting arrangement which tracks the wind direction and permits collection of discrete samples. A preset timer controls the length of time each filter is in the sampling position. At the conclusion of the sampling period a new filter is automatically moved into sampling position displacing the previous filter to a storage compartment. Thus the Air Scout may be set up at a field location, loaded with up to 12 filter slides, and left to acquire air samples automatically, according to the wind, at any timer interval desired from 1 to 30 hours.

Integrated Testing of a Carbon Dioxide Removal Assembly and a Temperature-Swing Adsorption Compressor for Closed-Loop Air Revitalization

NASA Technical Reports Server (NTRS)

Knox, J. C.; Mulloth, Lila; Frederick, Kenneth; Affleck, Dave

2003-01-01

Accumulation and subsequent compression of carbon dioxide that is removed from space cabin are two important processes involved in a closed-loop air revitalization scheme of the International Space Station (ISS). The carbon dioxide removal assembly (CDRA) of ISS currently operates in an open loop mode without a compressor. This paper describes the integrated test results of a flight-like CDRA and a temperature-swing adsorption compressor (TSAC) for carbon dioxide removal and compression. The paper provides details of the TSAC operation at various CO2 loadings and corresponding performance of CDRA.

Evaluation of a Commercial Air Filter for Removal of Virus from the Air

PubMed Central

Roelants, P.; Boon, B.; Lhoest, W.

1968-01-01

The effectiveness of a commercial absolute air filter for removal of viruses from air was tested with an actinophage, under the usual conditions of a laminar airflow clean room. A new method of dry phage dispersion is described. The filter showed an average reduction of 99.996% of airborne actinophage. PMID:5684200

A synthesis approach for reproducing the response of aircraft panels to a turbulent boundary layer excitation.

PubMed

Bravo, Teresa; Maury, Cédric

2011-01-01

Random wall-pressure fluctuations due to the turbulent boundary layer (TBL) are a feature of the air flow over an aircraft fuselage under cruise conditions, creating undesirable effects such as cabin noise annoyance. In order to test potential solutions to reduce the TBL-induced noise, a cost-efficient alternative to in-flight or wind-tunnel measurements involves the laboratory simulation of the response of aircraft sidewalls to high-speed subsonic TBL excitation. Previously published work has shown that TBL simulation using a near-field array of loudspeakers is only feasible in the low frequency range due to the rapid decay of the spanwise correlation length with frequency. This paper demonstrates through theoretical criteria how the wavenumber filtering capabilities of the radiating panel reduces the number of sources required, thus dramatically enlarging the frequency range over which the response of the TBL-excited panel is accurately reproduced. Experimental synthesis of the panel response to high-speed TBL excitation is found to be feasible over the hydrodynamic coincidence frequency range using a reduced set of near-field loudspeakers driven by optimal signals. Effective methodologies are proposed for an accurate reproduction of the TBL-induced sound power radiated by the panel into a free-field and when coupled to a cavity.

Hemodialysis dialyzers contribute to contamination of air microemboli that bypass the alarm system in the air trap.

PubMed

Stegmayr, C; Jonsson, P; Forsberg, U; Stegmayr, B

2008-04-01

Previous studies have shown that micrometer-sized air bubbles are introduced into the patient during hemodialysis. The aim of this study was to investigate, in vitro, the influence of dialysis filters on the generation of air bubbles. Three different kind of dialyzers were tested: one high-flux FX80 dry filter (Fresenius Medical Care AG&Co. KGaA, Bad Homburg, Germany), one low-flux F8HPS dry filter (Fresenius Medical Care AG&Co. KGaA, Bad Homburg, Germany) and a wet-stored APS-18u filter (Asahi Kasei Medical, Tokyo, Japan). The F8HPS was tested with pump flow ranging between 100 to 400 ml/min. The three filters were compared using a constant pump flow of 300 ml/min. Measurements were performed using an ultrasound Doppler instrument. In 90% of the series, bubbles were measured after the outlet line of the air trap without triggering an alarm. There were significantly more bubbles downstream than upstream of the filters F8HPS and FX80, while there was a significant reduction using the APS-18u. There was no reduction in the number of bubbles after passage through the air trap versus before the air trap (after the dialyzer). Increased priming volume reduced the extent of bubbles in the system. Data indicate that the air trap does not prevent air microemboli from entering the venous outlet part of the dialysis tubing (entry to the patient). More extended priming of the dialysis circuit may reduce the extent of microemboli that originate from dialysis filters. A wet filter may be favorable instead of dry-steam sterilized filters.

Effects of the window openings on the micro-environmental condition in a school bus

NASA Astrophysics Data System (ADS)

Li, Fei; Lee, Eon S.; Zhou, Bin; Liu, Junjie; Zhu, Yifang

2017-10-01

School bus is an important micro-environment for children's health because the level of in-cabin air pollution can increase due to its own exhaust in addition to on-road traffic emissions. However, it has been challenging to understand the in-cabin air quality that is associated with complex airflow patterns inside and outside a school bus. This study conducted Computational Fluid Dynamics (CFD) modeling analyses to determine the effects of window openings on the self-pollution for a school bus. Infiltration through the window gaps is modeled by applying variable numbers of active computational cells as a function of the effective area ratio of the opening. The experimental data on ventilation rates from the literature was used to validate the model. Ultrafine particles (UFPs) and black carbon (BC) concentrations were monitored in ;real world; field campaigns using school buses. This modeling study examined the airflow pattern inside the school bus under four different types of side-window openings at 20, 40, and 60 mph (i.e., a total of 12 cases). We found that opening the driver's window could allow the infiltration of exhaust through window/door gaps in the back of school bus; whereas, opening windows in the middle of the school bus could mitigate this phenomenon. We also found that an increased driving speed (from 20 mph to 60 mph) could result in a higher ventilation rate (up to 3.4 times) and lower mean age of air (down to 0.29 time) inside the bus.

Sabatier Catalyst Poisoning Investigation

NASA Technical Reports Server (NTRS)

Nallette, Tim; Perry, Jay; Abney, Morgan; Knox, Jim; Goldblatt, Loel

2013-01-01

The Carbon Dioxide Reduction Assembly (CRA) on the International Space Station (ISS) has been operational since 2010. The CRA uses a Sabatier reactor to produce water and methane by reaction of the metabolic CO2 scrubbed from the cabin air and the hydrogen byproduct from the water electrolysis system used for metabolic oxygen generation. Incorporating the CRA into the overall air revitalization system has facilitated life support system loop closure on the ISS reducing resupply logistics and thereby enhancing longer term missions. The CRA utilizes CO2 which has been adsorbed in a 5A molecular sieve within the Carbon Dioxide Removal Assembly, CDRA. There is a potential of compounds with molecular dimensions similar to, or less than CO2 to also be adsorbed. In this fashion trace contaminants may be concentrated within the CDRA and subsequently desorbed with the CO2 to the CRA. Currently, there is no provision to remove contaminants prior to entering the Sabatier catalyst bed. The risk associated with this is potential catalyst degradation due to trace organic contaminants in the CRA carbon dioxide feed acting as catalyst poisons. To better understand this risk, United Technologies Aerospace System (UTAS) has teamed with MSFC to investigate the impact of various trace contaminants on the CRA catalyst performance at relative ISS cabin air concentrations and at about 200/400 times of ISS concentrations, representative of the potential concentrating effect of the CDRA molecular sieve. This paper summarizes our initial assessment results.

Personal continuous air monitor

DOEpatents

Morgan, Ronald G.; Salazar, Samuel A.

2000-01-01

A personal continuous air monitor capable of giving immediate warning of the presence of radioactivity has a filter/detector head to be worn in the breathing zone of a user, containing a filter mounted adjacent to radiation detectors, and a preamplifier. The filter/detector head is connected to a belt pack to be worn at the waist or on the back of a user. The belt pack contains a signal processor, batteries, a multichannel analyzer, a logic circuit, and an alarm. An air pump also is provided in the belt pack for pulling air through the filter/detector head by way of an air tube.

Design Concept for a Minimal Volume Spacecraft Cabin to Serve as a Mars Ascent Vehicle Cabin and Other Alternative Pressurized Vehicle Cabins

NASA Technical Reports Server (NTRS)

Howard, Robert L., Jr.

2016-01-01

The Evolvable Mars Campaign is developing concepts for human missions to the surface of Mars. These missions are round-trip expeditions, thereby requiring crew launch via a Mars Ascent Vehicle (MAV). A study to identify the smallest possible pressurized cabin for this mission has developed a conceptual vehicle referred to as the minimal MAV cabin. The origin of this concept will be discussed as well as its initial concept definition. This will lead to a description of possible configurations to integrate the minimal MAV cabin with ascent vehicle engines and propellant tanks. Limitations of this concept will be discussed, in particular those that argue against the use of the minimal MAV cabin to perform the MAV mission. However, several potential alternative uses for the cabin are identified. Finally, recommended forward work will be discussed, including current work in progress to develop a full scale mockup and conduct usability evaluations.

Receptacle for Optical-Fiber Scraps

NASA Technical Reports Server (NTRS)

Nevin, R.

1986-01-01

Small pieces of glass trapped by moving air. Device traps fibers in section of black air-conditioner filter material. Filter section rests on metal screen above axial fan, which pulls air down through filter. Fan is small, quiet unit of type ordinarily used to cool electronic equipment.

Fibrous Filter to Protect Building Environments from Polluting Agents: A Review

NASA Astrophysics Data System (ADS)

Chavhan, Md. Vaseem; Mukhopadhyay, Arunangshu

2016-04-01

This paper discusses the use of fibrous filter to protect the building environments from air born polluting agents and especially of concern chemical, biological and radiological agents. Air-filtration includes removal of particulate from air and toxic gases from air. In air filtration, particulate which are mostly biological and radioactive types of agents can be removed by using mechanical and electrostatic filters. Some biological agents, which cannot be removed by air filtration alone, special techniques like antimicrobial finish, UV germicides, coated filters etc. are required. Biocide agent can be added into the fibre itself by grafting reaction to impart antimicrobial activity. Chemical agents like toxic gases can be removed by integrating adsorbents and sorbents in filters or by fibre modifications. It is also possible to impart catalytic conversion properties into the fibre to remove volatile gasous. Radioactive agents can be removed by particulate filter if present in the form of aerosol or by gas cleaning by the use of specific fibre impregnate.

14 CFR 121.578 - Cabin ozone concentration.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Cabin ozone concentration. 121.578 Section... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.578 Cabin ozone concentration... successfully demonstrated to the Administrator that the concentration of ozone inside the cabin will not exceed...

14 CFR 121.578 - Cabin ozone concentration.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Cabin ozone concentration. 121.578 Section... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.578 Cabin ozone concentration... successfully demonstrated to the Administrator that the concentration of ozone inside the cabin will not exceed...

14 CFR 121.578 - Cabin ozone concentration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Cabin ozone concentration. 121.578 Section... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.578 Cabin ozone concentration... successfully demonstrated to the Administrator that the concentration of ozone inside the cabin will not exceed...

14 CFR 121.578 - Cabin ozone concentration.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Cabin ozone concentration. 121.578 Section... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.578 Cabin ozone concentration... successfully demonstrated to the Administrator that the concentration of ozone inside the cabin will not exceed...

14 CFR 121.578 - Cabin ozone concentration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Cabin ozone concentration. 121.578 Section... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.578 Cabin ozone concentration... successfully demonstrated to the Administrator that the concentration of ozone inside the cabin will not exceed...

Isokinetic air sampler

DOEpatents

Sehmel, George A.

1979-01-01

An isokinetic air sampler includes a filter, a holder for the filter, an air pump for drawing air through the filter at a fixed, predetermined rate, an inlet assembly for the sampler having an inlet opening therein of a size such that isokinetic air sampling is obtained at a particular wind speed, a closure for the inlet opening and means for simultaneously opening the closure and turning on the air pump when the wind speed is such that isokinetic air sampling is obtained. A system incorporating a plurality of such samplers provided with air pumps set to draw air through the filter at the same fixed, predetermined rate and having different inlet opening sizes for use at different wind speeds is included within the ambit of the present invention as is a method of sampling air to measure airborne concentrations of particulate pollutants as a function of wind speed.

HEPA air filter (image)

MedlinePlus

... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

75 FR 38945 - Airworthiness Directives; The Boeing Company Model 777-200 and -300 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-07

..., 2006. The service bulletin describes procedures for installing new operational software in the cabin... loading the new cabin services system central storage device software and CSCP OPS into the MMC. FAA's... cabin services system central storage device software and cabin system control panel operational...

Impact of dangerous microclimate conditions within an enclosed vehicle on pediatric thermoregulation

NASA Astrophysics Data System (ADS)

Grundstein, Andrew; Duzinski, Sarah; Null, Jan

2017-01-01

Pediatric vehicular hyperthermia (PVH) persists as the leading cause of non-crash, vehicle-related deaths among US children with an average of 37 children dying after being left unattended in motor vehicles each year. Our study aims to demonstrate the microclimate conditions within an enclosed vehicle that lead infants and small children to reach key physiological heat thresholds: uncompensable heating (>37 °C) and heatstroke (>40 °C) under "worst case" conditions. A modified version of the Man-Environment Heat Exchange Model was used to compute the length of time for an infant to reach these thresholds. Several different scenarios were modeled using different initial cabin air temperatures. Assuming full sun exposure and maximum heating rates, an infant may reach uncompensable heating within 5 min and experience hyperthermia anywhere from 15 to 55 min depending on the starting cabin air temperature. The rapid approach of these heat-related thresholds occurs as enclosed vehicles maximize heating and minimize cooling mechanisms, leading to net heating and increase in core body temperatures. Health experts can use this information to support public health messaging on the topic of PVH by explaining why it is important to never leave a child alone in a car and increase the public perception of severity and susceptibility to this ongoing public health issue.

Passive interior noise reduction analysis of King Air 350 turboprop aircraft using boundary element method/finite element method (BEM/FEM)

NASA Astrophysics Data System (ADS)

Dandaroy, Indranil; Vondracek, Joseph; Hund, Ron; Hartley, Dayton

2005-09-01

The objective of this study was to develop a vibro-acoustic computational model of the Raytheon King Air 350 turboprop aircraft with an intent to reduce propfan noise in the cabin. To develop the baseline analysis, an acoustic cavity model of the aircraft interior and a structural dynamics model of the aircraft fuselage were created. The acoustic model was an indirect boundary element method representation using SYSNOISE, while the structural model was a finite-element method normal modes representation in NASTRAN and subsequently imported to SYSNOISE. In the acoustic model, the fan excitation sources were represented employing the Ffowcs Williams-Hawkings equation. The acoustic and the structural models were fully coupled in SYSNOISE and solved to yield the baseline response of acoustic pressure in the aircraft interior and vibration on the aircraft structure due to fan noise. Various vibration absorbers, tuned to fundamental blade passage tone (100 Hz) and its first harmonic (200 Hz), were applied to the structural model to study their effect on cabin noise reduction. Parametric studies were performed to optimize the number and location of these passive devices. Effects of synchrophasing and absorptive noise treatments applied to the aircraft interior were also investigated for noise reduction.

Evaluation of inlet sampling integrity on NSF/NCAR airborne platforms

NASA Astrophysics Data System (ADS)

Campos, T. L.; Stith, J. L.; Stephens, B. B.; Romashkin, P.

2017-12-01

An inlet test project was conducted during IDEAS-IV-GV (2013), to evaluate the sampling integrity of two inlet designs. Use of a single CO2 sensor provided a high precision detector and a large difference in the mean cabin and external concentrations (500-700 ppmv in the cabin). The original HIAPER Modular InLet (HIMIL) is comprised of a tapered flow straightening flow through `cigar' mounted to a strut. The cigar center sampling line sits 12" from the fuselage skin. An o-ring seals the feedthrough plate coupling sampling lines from the strut into the cigar. However, there is no seal to prevent air inside the strut from seeping out around the cigar body. A pressure-equalizing drain hole in the strut access panel; it was positioned at an approximate distance of 4" from the fuselage to ensure that air from any source that drained out of the strut was confined to a low release point. A second aft-facing inlet design was also evaluated. The sampling center line was moved farther from the fuselage at a height of 16". A similar approach was also applied to sampling locations on the C-130 in 2015. The results of these tests and recommendations for best practices will be presented.

Methodology for modeling the microbial contamination of air filters.

PubMed

Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

2014-01-01

In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter.

89. Puckett Cabin. The cabin constructed by John Puckett around ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

89. Puckett Cabin. The cabin constructed by John Puckett around 1865 is a good example of the one-room log cabin once common to the mountains. This was the home of Mrs. Oleana Puckett who died in 1939 at the age of 102. She worked as a midwife in the surrounding area, assisting in the delivery of more than 1,000 children. View looking east. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, John F; Huff, Shean P; West, Brian H

2012-01-01

Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Fourmore » of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.« less

40 CFR 94.211 - Emission-related maintenance instructions for purchasers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... filter change, fuel filter change, air filter change, cooling system maintenance, adjustment of idle... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES... at 1,500-hour intervals thereafter. (i) Exhaust gas recirculation system-related filters and coolers...

COMPUTATIONS ON THE PERFORMANCE OF PARTICLE FILTERS AND ELECTRONIC AIR CLEANERS

EPA Science Inventory

The paper discusses computations on the performance of particle filters and electronic air cleaners (EACs). The collection efficiency of particle filters and ACs is calculable if certain factors can be assumed or calibrated. For fibrous particulate filters, measurement of colle...

Spacecraft Crew Cabin Condensation Control

NASA Technical Reports Server (NTRS)

Carrillo, Laurie Y.; Rickman, Steven L.; Ungar, Eugene K.

2013-01-01

A report discusses a new technique to prevent condensation on the cabin walls of manned spacecraft exposed to the cold environment of space, as such condensation could lead to free water in the cabin. This could facilitate the growth of mold and bacteria, and could lead to oxidation and weakening of the cabin wall. This condensation control technique employs a passive method that uses spacecraft waste heat as the primary wallheating mechanism. A network of heat pipes is bonded to the crew cabin pressure vessel, as well as the pipes to each other, in order to provide for efficient heat transfer to the cabin walls and from one heat pipe to another. When properly sized, the heat-pipe network can maintain the crew cabin walls at a nearly uniform temperature. It can also accept and distribute spacecraft waste heat to maintain the pressure vessel above dew point.

Investigation of acoustic properties of a rigid foam with application to noise reduction in light aircraft

NASA Technical Reports Server (NTRS)

Holmer, C. I.

1972-01-01

A analytic model of sound transmission into an aircraft cabin was developed as well as test procedures which appropriately rank order properties which affect sound transmission. The proposed model agrees well with available data, and reveals that the pertinent properties of an aircraft cabin for sound transmission include: stiffness of cabin walls at low frequencies (as this reflects on impedance of the walls) and cabin wall transmission loss and interior absorption at mid and high frequencies. Below 315 Hz the foam contributes substantially to wall stiffness and sound transmission loss of typical light aircraft cabin construction, and could potentially reduce cabin noise levels by 3-5 db in this frequency range at a cost of about 0:2 lb/sq. ft. of treated cabin area. The foam was found not to have significant sound absorbing properties.

Chemical Protection Testing of Sorbent-Based Air Purification Components (APCs)

DTIC Science & Technology

2016-06-24

APC’s ability to filter air in a chemically contaminated environment. 15. SUBJECT TERMS Air purification component; APC; filtration fabric...FF, filter media, collective protection; individual protection. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18...incoming air. The intent of this process is to produce traceable, quantifiable, and defensible data that can be used to analyze an APC’s ability to filter

Wireless Network Simulation in Aircraft Cabins

NASA Technical Reports Server (NTRS)

Beggs, John H.; Youssef, Mennatoallah; Vahala, Linda

2004-01-01

An electromagnetic propagation prediction tool was used to predict electromagnetic field strength inside airplane cabins. A commercial software package, Wireless Insite, was used to predict power levels inside aircraft cabins and the data was compared with previously collected experimental data. It was concluded that the software could qualitatively predict electromagnetic propagation inside the aircraft cabin environment.

14 CFR 23.841 - Pressurized cabins.

Code of Federal Regulations, 2012 CFR

2012-01-01

... descent is made by an approved emergency procedure. A 17-second flight crew recognition and reaction time... altitude-time history shown in Figure 1 of this section. (ii) Maximum cabin altitude is limited to 30,000 feet. If cabin altitude exceeds 25,000 feet, the maximum time the cabin altitude may exceed 25,000 feet...

The potential for pulmonary heat injury resulting from the activation of a cabin water spray system to fight aircraft cabin fires.

DOT National Transportation Integrated Search

1995-05-01

A cabin water spray system (CWSS) has been suggested as a means of attenuating the severity of smoke and fire commonly associated with aircraft accidents. All aspects of passenger and cabin safety must be considered when evaluating a new safety syste...

Travelers' thrombosis.

PubMed

Johnston, Raymond V; Hudson, Martin F

2014-02-01

The suggestion that venous thromboembolism (VTE) is associated with air travel has for several decades been the subject of both "media hype" and extensive debate in the medical literature. As emotion and anecdote is often a feature in this debate, it is therefore necessary to separate evidence from anecdote. "Travelers' thrombosis" is a more appropriate term because the evidence suggests that any form of travel involving immobility lasting more than 4 h can predispose to thrombosis. There is no unique factor in the air travel cabin environment that has been shown to have any effect on the coagulation cascade. Prevention of thrombosis in any form of travel, including air travel, requires being aware of the issue and making an adequate risk assessment together with appropriate prophylactic measures.

Regenerable Air Purification System for Gas-Phase Contaminant Control

NASA Technical Reports Server (NTRS)

Constantinescu, Ileana C.; Qi, Nan; LeVan, M. Douglas; Finn, Cory K.; Finn, John E.; Luna, Bernadette (Technical Monitor)

2000-01-01

A regenerable air purification system (RAPS) that uses water vapor to displace adsorbed contaminants from an. adsorbent column into a closed oxidation loop is under development through cooperative R&D between Vanderbilt University and NASA Ames Research Center. A unit based on this design can be used for removing trace gas-phase contaminants from spacecraft cabin air or from polluted process streams including incinerator exhaust. Recent work has focused on fabrication and operation of a RAPS breadboard at NASA Ames, and on measurement of adsorption isotherm data for several important organic compounds at Vanderbilt. These activities support the use and validation of RAPS modeling software also under development at Vanderbilt, which will in turn be used to construct a prototype system later in the project.

Preliminary study of TEC application in cooling system

NASA Astrophysics Data System (ADS)

Sulaiman, A. C.; Amin, N. A. M.; Saidon, M. S.; Majid, M. S. A.; Rahman, M. T. A.; Kazim, M. N. F. M.

2017-10-01

Integration of thermoelectric cooling (TEC) within a space cooling system in the lecturer room is studied. The studied area (air conditioned surrounding) is encapsulated with wall, floor, roof, and glass window. TEC module is placed on the glass window. The prototype of the studied compartment is designed using cabin container. The type and number of TEC module are studied and the effects on the cooling performance are analyzed as it is assumed to be tested within an air conditioned lecturer room. The experimental and mathematical modeling of the cooling system developed. It is expected that the mathematical modeling derived from this study will be used to estimate the use of the number of TEC module to be integrated with air conditioner unit where possible.

Problems in creation of modern air inlet filters of power gas turbine plants in Russia and methods of their solving

NASA Astrophysics Data System (ADS)

Mikhaylov, V. E.; Khomenok, L. A.; Sherapov, V. V.

2016-08-01

The main problems in creation and operation of modern air inlet paths of gas turbine plants installed as part of combined-cycle plants in Russia are presented. It is noted that design features of air inlet filters shall be formed at the stage of the technical assignment not only considering the requirements of gas turbine plant manufacturer but also climatic conditions, local atmospheric air dustiness, and a number of other factors. The recommendations on completing of filtration system for air inlet filter of power gas turbine plants depending on the facility location are given, specific defects in design and experience in operation of imported air inlet paths are analyzed, and influence of cycle air preparation quality for gas turbine plant on value of operating expenses and cost of repair works is noted. Air treatment equipment of various manufacturers, influence of aerodynamic characteristics on operation of air inlet filters, features of filtration system operation, anti-icing system, weather canopies, and other elements of air inlet paths are considered. It is shown that nonuniformity of air flow velocity fields in clean air chamber has a negative effect on capacity and aerodynamic resistance of air inlet filter. Besides, the necessity in installation of a sufficient number of differential pressure transmitters allowing controlling state of each treatment stage not being limited to one measurement of total differential pressure in the filtration system is noted in the article. According to the results of the analysis trends and methods for modernization of available equipment for air inlet path, the importance of creation and implementation of new technologies for manufacturing of filtering elements on sites of Russia within the limits of import substitution are given, and measures on reliability improvement and energy efficiency for air inlet filter are considered.

Antimicrobial nanoparticle-coated electrostatic air filter with high filtration efficiency and low pressure drop.

PubMed

Sim, Kyoung Mi; Park, Hyun-Seol; Bae, Gwi-Nam; Jung, Jae Hee

2015-11-15

In this study, we demonstrated an antimicrobial nanoparticle-coated electrostatic (ES) air filter. Antimicrobial natural-product Sophora flavescens nanoparticles were produced using an aerosol process, and were continuously deposited onto the surface of air filter media. For the electrostatic activation of the filter medium, a corona discharge electrification system was used before and after antimicrobial treatment of the filter. In the antimicrobial treatment process, the deposition efficiency of S. flavescens nanoparticles on the ES filter was ~12% higher than that on the pristine (Non-ES) filter. In the evaluation of filtration performance using test particles (a nanosized KCl aerosol and submicron-sized Staphylococcus epidermidis bioaerosol), the ES filter showed better filtration efficiency than the Non-ES filter. However, antimicrobial treatment with S. flavescens nanoparticles affected the filtration efficiency of the filter differently depending on the size of the test particles. While the filtration efficiency of the KCl nanoparticles was reduced on the ES filter after the antimicrobial treatment, the filtration efficiency was improved after the recharging process. In summary, we prepared an antimicrobial ES air filter with >99% antimicrobial activity, ~92.5% filtration efficiency (for a 300-nm KCl aerosol), and a ~0.8 mmAq pressure drop (at 13 cm/s). This study provides valuable information for the development of a hybrid air purification system that can serve various functions and be used in an indoor environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Ozone and Ozone By-Products in the Cabins of Commercial Aircraft

PubMed Central

Weisel, Clifford; Weschler, Charles J.; Mohan, Kris; Vallarino, Jose; Spengler, John D.

2013-01-01

The aircraft cabin represents a unique indoor environment due to its high surface-to-volume ratio, high occupant density and the potential for high ozone concentrations at cruising altitudes. Ozone was continuously measured and air was sampled on sorbent traps, targeting carbonyl compounds, on 52 transcontinental U.S. or international flights between 2008 and 2010. The sampling was predominantly on planes that did not have ozone scrubbers (catalytic converters). Peak ozone levels on aircraft without catalytic convertors exceeded 100 ppb, with some flights having periods of more than an hour when the ozone levels were > 75ppb. Ozone was greatly reduced on relatively new aircraft with catalytic convertors, but ozone levels on two flights whose aircraft had older convertors were similar to those on planes without catalytic convertors. Hexanal, heptanal, octanal, nonanal, decanal and 6-methyl-5-hepten-2-one (6-MHO) were detected in the aircraft cabin at sub- to low ppb levels. Linear regression models that included the log transformed mean ozone concentration, percent occupancy and plane type were statistically significant and explained between 18 and 25% of the variance in the mixing ratio of these carbonyls. Occupancy was also a significant factor for 6-MHO, but not the linear aldehydes, consistent with 6-MHO’s formation from the reaction between ozone and squalene, which is present in human skin oils. PMID:23517299

Control of airborne infectious diseases in ventilated spaces

PubMed Central

Nielsen, Peter V.

2009-01-01

We protect ourselves from airborne cross-infection in the indoor environment by supplying fresh air to a room by natural or mechanical ventilation. The air is distributed in the room according to different principles: mixing ventilation, displacement ventilation, etc. A large amount of air is supplied to the room to ensure a dilution of airborne infection. Analyses of the flow in the room show that there are a number of parameters that play an important role in minimizing airborne cross-infection. The air flow rate to the room must be high, and the air distribution pattern can be designed to have high ventilation effectiveness. Furthermore, personalized ventilation may reduce the risk of cross-infection, and in some cases, it can also reduce the source of infection. Personalized ventilation can especially be used in hospital wards, aircraft cabins and, in general, where people are in fixed positions. PMID:19740921

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2011 CFR

2011-07-01

... change, oil filter change, fuel filter change, air filter change, cooling system maintenance, adjustment... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION...) Exhaust gas recirculation system-related filters and coolers. (ii) Positive crankcase ventilation valve...

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2010 CFR

2010-07-01

... change, oil filter change, fuel filter change, air filter change, cooling system maintenance, adjustment... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION...) Exhaust gas recirculation system-related filters and coolers. (ii) Positive crankcase ventilation valve...

Microbial Anomalies Encountered on the International Space Station

NASA Technical Reports Server (NTRS)

Bruce, Rebekah J.; Wong, Wing; Pierson, Duane; Castro, Victoria

2010-01-01

Microorganisms in our living environments are unavoidable. A community of microbes arrived in space with the delivery of the first element of the International Space Station (ISS), attached to hardware and on the bodies of the humans tasked with the initial assembly missions. The risk that microorganisms could cause adverse effects in the health of both the human occupants of the ISS as well as the physical integrity of the station environment and life support systems has been both a driver and a function of engineering and operational controls. Scientists and engineers at NASA have gone to extensive measures to control microbial growth at levels safe for the crewmembers and the spacecraft environment. Many of these measures were initiated with the design of the spacecraft and its systems. Materials used in the ISS were tested for resistance to fungi, such as mold and a paint with a fungus-killing chemical was also used. Controlling the humidity of the air in the Station is also an effective way of discouraging microbe growth. The breathing air is reconditioned by the Environmental Control Life Support System (ECLSS) prior to distribution, utilizing High Efficiency Particulate Air (HEPA) filtration. Requirements restricting the accumulation of water condensate in the air handlers and habitable volume of the ISS were other safeguards added. Water for drinking and food rehydration is disinfected or filtered. A robust in-flight housekeeping regimen for the ISS significantly reduces inappropriate growth of microorganisms and includes a regular cleaning of accessible surfaces with disinfectant wipes. Most of these requirements were suggested by microbiologists to mitigate and possibly prevent many microbiological risks. In addition to these controls, before flight monitoring and analyses of the cabin air, exposed surfaces, water and food, consumables, and crew members are conducted to mitigate microbial risk to the crew and spacecraft. Many microbial risks are much easier to identify and resolve before launch than during space flight. Although the focus has been on prevention of microbiologically related, not all problems can be anticipated. A number of microbial anomalies have occurred on ISS. This paper will discuss the occurrences, root-cause investigations, and mitigation steps taken to remediate the contamination.

Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Murray E.

Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to massmore » flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is expected to require six months of time, after receipt of funding. Benefits: US DOE facilities that use HEPA filters will benefit from access to the new operational measurement methods. Uncertainty and guesswork will be removed from HEPA filter operations.« less

77 FR 60887 - Airworthiness Directives; Alpha Aviation Concept Limited Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-05

... possible installation of non-conforming air filter elements that are not fitted with metallic mesh and... finding a non conforming air filter fitted to an overseas aircraft during maintenance. Investigation revealed that air filters with P/N 57.34.00.010 supplied by CEAPR between June 2009 and April 2012 may not...

77 FR 44511 - Airworthiness Directives; Alpha Aviation Concept Limited Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... possible installation of non-conforming air filter elements that are not fitted with metallic mesh and... conforming air filter fitted to an overseas aircraft during maintenance. Investigation revealed that air filters with P/N 57.34.00.010 supplied by CEAPR between June 2009 and April 2012 may not have the metallic...

40 CFR 721.10411 - Alkanenitrile, bis(cyanoalkyl)amino (generic) (P-07-537).

Code of Federal Regulations, 2012 CFR

2012-07-01

... with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified powered air-purifying respirator equipped with a loose- fitting hood or helmet and high efficiency particulate air (HEPA) filters... HEPA filters; or NIOSH-certified supplied-air respirator operated in pressure demand or continuous flow...

40 CFR 721.10411 - Alkanenitrile, bis(cyanoalkyl)amino (generic) (P-07-537).

Code of Federal Regulations, 2013 CFR

2013-07-01

... with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified powered air-purifying respirator equipped with a loose- fitting hood or helmet and high efficiency particulate air (HEPA) filters... HEPA filters; or NIOSH-certified supplied-air respirator operated in pressure demand or continuous flow...

40 CFR 721.10411 - Alkanenitrile, bis(cyanoalkyl)amino (generic) (P-07-537).

Code of Federal Regulations, 2014 CFR

2014-07-01

... with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified powered air-purifying respirator equipped with a loose- fitting hood or helmet and high efficiency particulate air (HEPA) filters... HEPA filters; or NIOSH-certified supplied-air respirator operated in pressure demand or continuous flow...

75 FR 28485 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... caution light CABIN DOOR signaling both MED Improper Closure and MED Inflatable Seal Failure into two separate lights: CABIN DOOR and CABIN DOOR SEAL. 2. Converting the separated CABIN DOOR Caution light into a Warning light by changing its color to red. Note: Aircraft Flight Manuals (AFM'S) refer to these...

Protecting log cabins from decay

Treesearch

R. M. Rowell; J. M. Black; L. R. Gjovik; W. C. Feist

1977-01-01

This report answers the questions most often asked of the Forest Service on the protection of log cabins from decay, and on practices for the exterior finishing and maintenance of existing cabins. Causes of stain and decay are discussed, as are some basic techniques for building a cabin that will minimize decay. Selection and handling of logs, their preservative...

Treated cabin acoustic prediction using statistical energy analysis

NASA Technical Reports Server (NTRS)

Yoerkie, Charles A.; Ingraham, Steven T.; Moore, James A.

1987-01-01

The application of statistical energy analysis (SEA) to the modeling and design of helicopter cabin interior noise control treatment is demonstrated. The information presented here is obtained from work sponsored at NASA Langley for the development of analytic modeling techniques and the basic understanding of cabin noise. Utility and executive interior models are developed directly from existing S-76 aircraft designs. The relative importance of panel transmission loss (TL), acoustic leakage, and absorption to the control of cabin noise is shown using the SEA modeling parameters. It is shown that the major cabin noise improvement below 1000 Hz comes from increased panel TL, while above 1000 Hz it comes from reduced acoustic leakage and increased absorption in the cabin and overhead cavities.

Aircraft disinsection: exposure assessment and evaluation of a new pre-embarkation method.

PubMed

Berger-Preiss, Edith; Koch, Wolfgang; Gerling, Susanne; Kock, Heiko; Klasen, Jutta; Hoffmann, Godehard; Appel, Klaus E

2006-01-01

A new "pre-embarkation" method for aircraft disinsection was investigated using two different 2% d-phenothrin containing aerosols. Five experiments in aircrafts of the type Airbus 310 (4x) and Boeing 747-400 (1x) were performed. In the absence of passengers and crew the d-phenothrin aerosol was sprayed under the seat rows and in a second step at the height of approximately 1.60 m by moving from one end of the cabin to the other. Concentration levels of d-phenothrin were determined at different time periods after application of the aerosol spray. In a B 747-400 with the air conditioning system operating the concentrations ranged between 853 and 1753 microg/m3 during and till 5 min after the beginning of spraying at different locations in the cabin. Within 5-20min after the end of the spraying concentrations of 36-205 microg/m3 and 20-40 min thereafter only ca. 1 microg d-phenothrin/m3 were detectable (average values in relation to each period of measurement). On cabin interior surfaces the median values for mainly horizontal areas ranged from 100 to 1160 ng d-phenothrin/cm2. d-Phenothrin concentrations in the air were sufficient to kill flying insects like house flies and mosquitoes within 20 min. Horizontal surfaces were 100% effective against insects up to 24 h after spraying. Doses inhaled by sprayers determined by personal measurements were calculated to be 30-235 microg d-phenothrin per 100 g spray applied (30% in the respirable fraction for Arrow Aircraft Disinsectant; 10% for Aircraft Disinsectant Denka). If passengers will board, e.g., 20 min after the end of the disinsection operation, inhalation exposure is estimated to be practically negligible. Also possible dermal exposure from residues in seats and headrests is very low for passengers during the flight. Therefore any health effects for passengers and crew members are very unlikely.

Concentrations of volatile organic compounds, carbon monoxide, carbon dioxide and particulate matter in buses on highways in Taiwan

NASA Astrophysics Data System (ADS)

Hsu, Der-Jen; Huang, Hsiao-Lin

2009-12-01

Although airborne pollutants in urban buses have been studied in many cities globally, long-distance buses running mainly on highways have not been addressed in this regard. This study investigates the levels of volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO 2) and particulate matter (PM) in the long-distance buses in Taiwan. Analytical results indicate that pollutants levels in long-distance buses are generally lower than those in urban buses. This finding is attributable to the driving speed and patterns of long-distance buses, as well as the meteorological and geographical features of the highway surroundings. The levels of benzene, toluene, ethylbenzene and xylene (BTEX) found in bus cabins exceed the proposed indoor VOC guidelines for aromatic compounds, and are likely attributable to the interior trim in the cabins. The overall average CO level is 2.3 ppm, with higher average level on local streets (2.9 ppm) than on highways (2.2 ppm). The average CO 2 level is 1493 ppm, which is higher than the guideline for non-industrial occupied settings. The average PM level in this study is lower than those in urban buses and IAQ guidelines set by Taiwan EPA. However, the average PM 10 and PM 2.5 is higher than the level set by WHO. Besides the probable causes mentioned above, fewer passenger movements and less particle re-suspension from bus floor might also cause the lower PM levels. Measurements of particle size distribution reveal that more than 75% of particles are in submicron and smaller sizes. These particles may come from the infiltration from the outdoor air. This study concludes that air exchange rates in long-distance buses should be increased in order to reduce CO 2 levels. Future research on long-distance buses should focus on the emission of VOCs from brand new buses, and the sources of submicron particles in bus cabins.

Gross Alpha Beta Radioactivity in Air Filters Measured by Ultra Low Level α/β Counter

NASA Astrophysics Data System (ADS)

Cfarku, Florinda; Bylyku, Elida; Deda, Antoneta; Dhoqina, Polikron; Bakiu, Erjona; Perpunja, Flamur

2010-01-01

Study of radioactivity in air as very important for life is done regularly using different methods in every country. As a result of nuclear reactors, atomic centrals, institutions and laboratories, which use the radioactivity substances in open or closed sources, there are a lot radioactive wastes. Mixing of these wastes after treatment with rivers and lakes waters makes very important control of radioactivity. At the other side nuclear and radiological accidents are another source of the contamination of air and water. Due to their radio toxicity, especially those of Sr90, Pu239, etc. a contamination hazard for human begins exist even at low concentration levels. Measurements of radioactivity in air have been performed in many parts of the world mostly for assessment of the doses and risk resulting from consuming air. In this study we present the results of international comparison organized by IAEA Vienna, Austria for the air filters spiked with unknown Alpha and Beta Activity. For the calibration of system we used the same filters spiked: a) with Pu-239 as alpha source; b) Sr-90 as beta source and also the blank filter. The measurements of air filter samples after calibration of the system are done with Ultra Low Level α/β Counter (MPC 9604) Protean Instrument Corporation. The high sensitivity of the system for the determination of the Gross Alpha and Beta activity makes sure detection of low values activity of air filters. Our laboratory results are: Aα = (0.19±0.01) Bq/filter and Aα (IAEA) = (0.17±0.009) Bq/filter; Aβ = (0.33±0.009) Bq/filter and Aβ (IAEA) = (0.29±0.01) Bq/filter. As it seems our results are in good agreement with reference values given by IAEA (International Atomic Energy Agency).

78 FR 5773 - Notification of Proposed Production Activity, Generac Power Systems, Inc., Subzone 41J...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-28

... assemblies; oil/fuel filters; air/oil separation equipment; air filters/elements; catalytic converters... assemblies; AC line filters; dielectric items of paper/plastic; capacitors; circuit breakers; switching...

Mold Occurring on the Air Cleaner High-Efficiency Particulate Air Filters Used in the Houses of Child Patients with Atopic Dermatitis

PubMed Central

Kim, Seong Hwan; Ahn, Geum Ran; Son, Seung Yeol; Bae, Gwi-Nam

2014-01-01

Fungi are the known sources of irritation associated with atopic diseases (e.g., asthma, allergic rhinoconjunctivitis, and atopic eczema). To quantitatively estimate their presence in the indoor environment of atopic dermatitis-inflicted child patient's houses (ADCPHs), the high-efficiency particulate air (HEPA) filters installed inside the air cleaners of three different ADCPHs were investigated for the presence of mold. The air cleaner HEPA filters obtained from the three different ADCPHs were coded as HEPA-A, -B, and -C, respectively, and tested for the presence of mold. The colony forming units (CFUs) corresponding to the HEPA-A, -B, and -C filters were estimated to be 6.51 × 102 ± 1.50 × 102 CFU/cm2, 8.72 × 102 ± 1.69 × 102 CFU/cm2, and 9.71 × 102 ± 1.35 × 102 CFU/cm2, respectively. Aspergillus, Penicillium, Alternaria, Cladosporium, Trichoderma, and other fungal groups were detected in the 2,494 isolates. The distribution of these fungal groups differed among the three filters. Cladosporium was the major fungal group in filters HEPA-A and -C, whereas Penicillium was the major fungal group in the filter HEPA-B. Nine fungal species, including some of the known allergenic species, were identified in these isolates. Cladosporium cladosporioides was the most common mold among all the three filters. This is the first report on the presence of fungi in the air cleaner HEPA filters from ADCPHs in Korea. PMID:25346608

Radon detection

DOEpatents

MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

1994-01-25

A detector for atmospheric radon using a long range alpha detector as its sensing element is described. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the signal output from the long range alpha detector consists of only the electronic background. With the second electrostatic filter deactivated, air ions and cosmic rays will be detected. The cosmic ray contribution can be minimized by shielding. 3 figures.

Radon detection

DOEpatents

MacArthur, Duncan W.; Allander, Krag S.; Bounds, John A.

1994-01-01

A detector for atmospheric radon using a long range alpha detector as its sensing element. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the signal output from the long range alpha detector consists of only the electronic background. With the second electrostatic filter deactivated, air ions and cosmic rays will be detected. The cosmic ray contribution can be minimized by shielding.

System and Apparatus for Filtering Particles

NASA Technical Reports Server (NTRS)

Agui, Juan H. (Inventor); Vijayakumar, Rajagopal (Inventor)

2015-01-01

A modular pre-filtration apparatus may be beneficial to extend the life of a filter. The apparatus may include an impactor that can collect a first set of particles in the air, and a scroll filter that can collect a second set of particles in the air. A filter may follow the pre-filtration apparatus, thus causing the life of the filter to be increased.

Aircraft Recirculation Filter for Air-Quality and Incident Assessment

PubMed Central

Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.

2015-01-01

The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters. PMID:25641977

Aircraft Recirculation Filter for Air-Quality and Incident Assessment.

PubMed

Eckels, Steven J; Jones, Byron; Mann, Garrett; Mohan, Krishnan R; Weisel, Clifford P

The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters.

Methodology for Modeling the Microbial Contamination of Air Filters

PubMed Central

Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

2014-01-01

In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter. PMID:24523908

Safety Versus Passenger Service: The Flight Attendants’ Dilemma

PubMed Central

Damos, Diane L.; Boyett, Kimberly S.; Gibbs, Patt

2013-01-01

After 9/11, new security duties were instituted at many U.S. air carriers and existing safety and security duties received increased emphasis. Concurrently, in-flight services were changed and in many cases, cabin crews were reduced. This article examines the post-9/11 conflict between passenger service and the timely performance of safety and security duties at 1 major U.S. air carrier. In-flight data were obtained on both international and domestic flights. The data suggest that the prompt performance of the safety and security duties is adversely affected by the number of service duties occurring in the later part of both international and domestic flights. PMID:23667300

USSR Report, Space Biology and Aerospace Medicine, Vol. 18, No. 2, March-April 1984.

DTIC Science & Technology

1984-05-16

changes in composition and quantity of autogenous microflora, micro- flora of cabin air and surfaces did not present an appreciable threat with respect...R., "Biological Chemistry ," Leningrad, 5th ed., 1972. 14. Bol’shakova, T. Z., in "Spravochnik prakticheskogo vracha" [Clinical Physician’s...physical factors. The gas composition was measured qualita- tively and quantitatively. This determination showed a higher content of acetone and

Nutrition and Resistance to Climatic Stress; With Particular Reference to Man

DTIC Science & Technology

1949-11-01

significantly to o~rational efficiency, or may reduce significantly the hazard of explosive decompression resulting from combat, when seconds of...the low 1 partial pressure of oxygen in the inspired air is a type of climatic stress presenting a serious hazard to the preservation of...oxygen is a complete defense against this hazard except in combat or in accident. The breath- ing of pure oxygen in an airplane cabin not so

Simultaneous removal of formaldehyde and benzene in indoor air with a combination of sorption- and decomposition-type air filters.

PubMed

Sekine, Yoshika; Fukuda, Mitsuru; Takao, Yosuke; Ozano, Takahiro; Sakuramoto, Hikaru; Wang, Kuan Wei

2011-12-01

Urgent measures for indoor air pollution caused by volatile organic compounds are required in urban areas of China. Considering indoor air concentration levels and hazardous properties, formaldehyde and benzene should be given priority for pollution control in China. The authors proposed the use of air-cleaning devices, including stand-alone room air cleaners and in-duct devices. This study aimed to find the best combination of sorption and decomposition filters for the simultaneous removal of formaldehyde and benzene, employing four types of air filter units: an activated charcoal filter (ACF), an ACF impregnated with a trapping agent for acidic gases (ACID), a MnO2 filter (MDF) for oxidative decomposition of formaldehyde at room temperature and a photocatalyst filter (PHOTO) coupled with a parallel beam ultraviolet (UV) irradiation device. The performance of the combined systems under air flow rates of 35-165 m3 h(-1) was evaluated in a test chamber (2 m3) with a constant gas generation system. The experimental results and data analysis using a kinetic approach showed the combined system of ACF, PHOTO and MDF significantly reduced both concentrations of formaldehyde and benzene in air without any unpleasant odours caused by the UV-induced photocatalytic reaction. The system was then evaluated in a full-size laboratory (22 m3). This test proved the practical performance of the system even at full scale, and also suggested that the filters should be arranged in the order of PHOTO/ACF/MDF from upstream to downstream. The proposed system has the potential of being used for improving indoor air quality of houses and buildings in China.

Impact of cabin environment on thermal protection system of crew hypersonic vehicle

NASA Astrophysics Data System (ADS)

Zhu, Xiao Wei; Zhao, Jing Quan; Zhu, Lei; Yu, Xi Kui

2016-05-01

Hypersonic crew vehicles need reliable thermal protection systems (TPS) to ensure their safety. Since there exists relative large temperature difference between cabin airflow and TPS structure, the TPS shield that covers the cabin is always subjected to a non-adiabatic inner boundary condition, which may influence the heat transfer characteristic of the TPS. However, previous literatures always neglected the influence of the inner boundary by assuming that it was perfectly adiabatic. The present work focuses on studying the impact of cabin environment on the thermal performance. A modified TPS model is created with a mixed thermal boundary condition to connect the cabin environment with the TPS. This helps make the simulation closer to the real situation. The results stress that cabin environment greatly influences the temperature profile inside the TPS, which should not be neglected in practice. Moreover, the TPS size can be optimized during the design procedure if taking the effect of cabin environment into account.

Test Operations Procedure (TOP) 08-2-197 Chemical Protection Testing of Sorbent-Based Air Purification Components (APCs)

DTIC Science & Technology

2016-06-24

APC’s ability to filter air in a chemically contaminated environment. 15. SUBJECT TERMS Air purification component; APC; filtration fabric...FF, filter media, collective protection; individual protection. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18...incoming air. The intent of this process is to produce traceable, quantifiable, and defensible data that can be used to analyze an APC’s ability to filter

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

Fractional kalman filter to estimate the concentration of air pollution

NASA Astrophysics Data System (ADS)

Vita Oktaviana, Yessy; Apriliani, Erna; Khusnul Arif, Didik

2018-04-01

Air pollution problem gives important effect in quality environment and quality of human’s life. Air pollution can be caused by nature sources or human activities. Pollutant for example Ozone, a harmful gas formed by NOx and volatile organic compounds (VOCs) emitted from various sources. The air pollution problem can be modeled by TAPM-CTM (The Air Pollution Model with Chemical Transport Model). The model shows concentration of pollutant in the air. Therefore, it is important to estimate concentration of air pollutant. Estimation method can be used for forecast pollutant concentration in future and keep stability of air quality. In this research, an algorithm is developed, based on Fractional Kalman Filter to solve the model of air pollution’s problem. The model will be discretized first and then it will be estimated by the method. The result shows that estimation of Fractional Kalman Filter has better accuracy than estimation of Kalman Filter. The accuracy was tested by applying RMSE (Root Mean Square Error).

[The use of individual protective devices for decreasing the microbial contamination of the inhaled air].

PubMed

Sedov, A V; Akin'shin, A V; Tregub, T I

1995-01-01

The work was aimed to justify application of gas masks and respirators with autonomous air source fo lower bacterial contamination of inhaled air. The studies also covered possible catch of bacteria by cotton and filters FPP-15-1.5, those composed of antimicrobial materials, containing furagin or copper ions. As the studies proved, for lower bacterial contaminations of inhaled air one can apply autonomous air source apparatus with filters made of Petrianov tissue, antimicrobial tissue (containing furagin or copper ions), as they reduce fungal content of the air. Such filters are self-disinfecting, but do not influence total contamination of the air.

Future Data Communication Architectures for Safety Critical Aircraft Cabin Systems

NASA Astrophysics Data System (ADS)

Berkhahn, Sven-Olaf

2012-05-01

The cabin of modern aircraft is subject to increasing demands for fast reconfiguration and hence flexibility. These demands require studies for new network architectures and technologies of the electronic cabin systems, which consider also weight and cost reductions as well as safety constraints. Two major approaches are in consideration to reduce the complex and heavy wiring harness: the usage of a so called hybrid data bus technology, which enables the common usage of the same data bus for several electronic cabin systems with different safety and security requirements and the application of wireless data transfer technologies for electronic cabin systems.

Airline chair-rest deconditioning: induction of immobilisation thromboemboli?

PubMed

Greenleaf, John E; Rehrer, Nancy J; Mohler, Stanley R; Quach, David T; Evans, David G

2004-01-01

Air passenger miles will likely double by year 2020. The altered and restrictive environment in an airliner cabin can influence haematological homeostasis in passengers and crew. Flight-related deep venous thromboemboli (DVT) have been associated with at least 577 deaths on 42 of 120 airlines from 1977 to 1984 (25 deaths/million departures), whereas many such cases go unreported. However, there are four major factors that could influence formation of possible flight-induced DVT: sleeping accommodations (via sitting immobilisation); travellers' medical history (via tissue injury); cabin environmental factors (via lower partial pressure of oxygen and lower relative humidity); and the more encompassing chair-rest deconditioning (C-RD) syndrome. There is ample evidence that recent injury and surgery (especially in deconditioned hospitalised patients) facilitate thrombophlebitis and formation of DVT that may be exacerbated by the immobilisation of prolonged air travel. In the healthy flying population, immobilisation factors associated with prolonged (>5 hours) C-RD such as total body dehydration, hypovolaemia and increased blood viscosity, and reduced venous blood flow (pooling) in the legs may facilitate formation of DVT. However, data from at least four case-controlled epidemiological studies did not confirm a direct causative relationship between air travel and DVT, but factors such as a history of vascular thromboemboli, venous insufficiency, chronic heart failure, obesity, immobile standing position, more than three pregnancies, infectious disease, long-distance travel, muscular trauma and violent physical effort were significantly more frequent in DVT patients than in controls. Thus, there is no clear, direct evidence yet that prolonged sitting in airliner seats, or prolonged experimental chair-rest or bed-rest deconditioning treatments cause DVT in healthy people.

Airline chair-rest deconditioning: induction of immobilisation thromboemboli?

NASA Technical Reports Server (NTRS)

Greenleaf, John E.; Rehrer, Nancy J.; Mohler, Stanley R.; Quach, David T.; Evans, David G.

2004-01-01

Air passenger miles will likely double by year 2020. The altered and restrictive environment in an airliner cabin can influence haematological homeostasis in passengers and crew. Flight-related deep venous thromboemboli (DVT) have been associated with at least 577 deaths on 42 of 120 airlines from 1977 to 1984 (25 deaths/million departures), whereas many such cases go unreported. However, there are four major factors that could influence formation of possible flight-induced DVT: sleeping accommodations (via sitting immobilisation); travellers' medical history (via tissue injury); cabin environmental factors (via lower partial pressure of oxygen and lower relative humidity); and the more encompassing chair-rest deconditioning (C-RD) syndrome. There is ample evidence that recent injury and surgery (especially in deconditioned hospitalised patients) facilitate thrombophlebitis and formation of DVT that may be exacerbated by the immobilisation of prolonged air travel.In the healthy flying population, immobilisation factors associated with prolonged (>5 hours) C-RD such as total body dehydration, hypovolaemia and increased blood viscosity, and reduced venous blood flow (pooling) in the legs may facilitate formation of DVT. However, data from at least four case-controlled epidemiological studies did not confirm a direct causative relationship between air travel and DVT, but factors such as a history of vascular thromboemboli, venous insufficiency, chronic heart failure, obesity, immobile standing position, more than three pregnancies, infectious disease, long-distance travel, muscular trauma and violent physical effort were significantly more frequent in DVT patients than in controls. Thus, there is no clear, direct evidence yet that prolonged sitting in airliner seats, or prolonged experimental chair-rest or bed-rest deconditioning treatments cause DVT in healthy people.

Organophosphate flame retardants in the indoor air and dust in cars in Japan.

PubMed

Tokumura, Masahiro; Hatayama, Rurika; Tatsu, Kouichi; Naito, Toshiyuki; Takeda, Tetsuya; Raknuzzaman, Mohammad; -Al-Mamun, Md Habibullah; Masunaga, Shigeki

2017-01-01

The concentrations of organophosphate flame retardants (OPFRs) in the indoor air and dust were measured in 25 unoccupied cars in Japan. In the indoor air of the cars, most OPFRs were neither detected nor found at a concentration lower than the method quantification limit. The highest concentration (1500 ng m -3 ) was obtained for tris(1-chloro-2-propyl) phosphate (TCIPP). By contrast, many OPFRs were detected in the dust samples collected from the interior of the cars. TCIPP and tris(2-ethylhexyl) phosphate (TEHP) were present at the highest concentrations at 390 μg g -1 (in dust from car seats) and 640 μg g -1 (in dust from car floor mats), respectively. The highest median concentrations (35 μg g -1 for car seats, 53 μg g -1 for car floor mats) were obtained for tris(2-butoxyethyl) phosphate (TBOEP). According to the results of our exposure assessment, the typical exposures to OPFRs via inhalation in car cabins ranged from 9.0×10 -4 to 7.8×10 -1 ng kg-bw -1 day -1 . The typical exposures to OPFRs via dust ingestion ranged from 9.2×10 -4 to 8.8×10 -1 ng kg-bw -1 day -1 . We compared these results with the ref-erence doses for OPFRs and found that, based on cur-rent information about the toxicities of OPFRs, exposure to OPFRs in car cabins via inhalation and dust ingestion is unlikely to have adverse human health effects.

Microlith-Based Catalytic Reactor for Air Quality and Trace Contaminant Control Applications

NASA Technical Reports Server (NTRS)

Vilekar, Saurabh; Hawley, Kyle; Junaedi, Christian; Crowder, Bruce; Prada, Julian; Mastanduno, Richard; Perry, Jay L.; Kayatin, Matthew J.

2015-01-01

Traditionally, gaseous compounds such as methane, carbon monoxide, and trace contaminants have posed challenges for maintaining clean air in enclosed spaces such as crewed spacecraft cabins as they are hazardous to humans and are often difficult to remove by conventional adsorption technology. Catalytic oxidizers have provided a reliable and robust means of disposing of even trace levels of these compounds by converting them into carbon dioxide and water. Precision Combustion, Inc. (PCI) and NASA - Marshall (MSFC) have been developing, characterizing, and optimizing high temperature catalytic oxidizers (HTCO) based on PCI's patented Microlith® technology to meet the requirements of future extended human spaceflight explorations. Current efforts have focused on integrating the HTCO unit with a compact, simple recuperative heat exchanger to reduce the overall system size and weight while also reducing its energy requirements. Previous efforts relied on external heat exchangers to recover the waste heat and recycle it to the oxidizer to minimize the system's power requirements; however, these units contribute weight and volume burdens to the overall system. They also result in excess heat loss due to the separation of the HTCO and the heat recuperator, resulting in lower overall efficiency. Improvements in the recuperative efficiency and close coupling of HTCO and heat recuperator lead to reductions in system energy requirements and startup time. Results from testing HTCO units integrated with heat recuperators at a variety of scales for cabin air quality control and heat melt compactor applications are reported and their benefits over previous iterations of the HTCO and heat recuperator assembly are quantified in this paper.

Airborne irritant contact dermatitis due to synthetic fibres from an air-conditioning filter.

PubMed

Patiwael, Jiska A; Wintzen, Marjolein; Rustemeyer, Thomas; Bruynzeel, Derk P

2005-03-01

We describe 8 cases of occupational airborne irritant contact dermatitis in intensive care unit (ICU) employees caused by synthetic (polypropylene and polyethylene) fibres from an air-conditioning filter. Not until a workplace investigation was conducted, was it possible to clarify the unusual sequence of events. High filter pressure in the intensive care air-conditioning system, maintained to establish an outward airflow and prevent microorganisms from entering the ward, probably caused fibres from the filter to become airborne. Upon contact with air-exposed skin, fibres subsequently provoked skin irritation. Test periods in the ICU with varying filter pressures, in an attempt to improve environmental conditions, led to even higher filter pressure levels and more complaints. The sometimes-very-low humidity might have contributed to development of skin irritation. The fact that most patients recovered quickly after treatment with emollients and changing the filters made it most likely that the airborne dermatitis was of an irritant nature.

High Efficiency, Transparent, Reusable, and Active PM2.5 Filters by Hierarchical Ag Nanowire Percolation Network.

PubMed

Jeong, Seongmin; Cho, Hyunmin; Han, Seonggeun; Won, Phillip; Lee, Habeom; Hong, Sukjoon; Yeo, Junyeob; Kwon, Jinhyeong; Ko, Seung Hwan

2017-07-12

Air quality has become a major public health issue in Asia including China, Korea, and India. Particulate matters are the major concern in air quality. We present the first environmental application demonstration of Ag nanowire percolation network for a novel, electrical type transparent, reusable, and active PM2.5 air filter although the Ag nanowire percolation network has been studied as a very promising transparent conductor in optoelectronics. Compared with previous particulate matter air filter study using relatively weaker short-range intermolecular force in polar polymeric nanofiber, Ag nanowire percolation network filters use stronger long-range electrostatic force to capture PM2.5, and they are highly efficient (>99.99%), transparent, working on an active mode, low power consumption, antibacterial, and reusable after simple washing. The proposed new particulate matter filter can be applied for a highly efficient, reusable, active and energy efficient filter for wearable electronics application.

Evaluating the Adsorptive Capabilites of Chemsorb 1000 and Chemsorb 1425

NASA Technical Reports Server (NTRS)

Mejia, Oscar Alberto Monje; Surma, Jan M.; Johnsey, Marissa; Melendez, Orlando

2014-01-01

The removal of trace contaminants from spacecraft cabin air is necessary for crew health and comfort during long duration space exploration missions. The air revitalization technologies used in these future exploration missions will evolve from current ISS ISS State-of-Art (SOA) and is being designed and tested by the Advanced Exploration Systems (AES) Program's Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project. The ARREM project is working to mature optimum atmosphere revitalization and environmental monitoring system architectures to enable exploration beyond Lower Earth Orbit (LEO). The Air Revitalization Lab at KSC is one of six NASA field centers participating in the ARREM that specializes in adsorbent and catalyst characterization with simulated spacecraft gas streams using combinations of pressure, O2 partial pressure, CO2 partial pressure, and humidity that are representative of a range of anticipated cabin atmospheric conditions and loads. On board ISS, the Trace Contaminant Control Subassembly (TCCS) provides active control of trace contaminants from the cabin atmosphere utilizing physical adsorption, thermal catalytic oxidation, and chemical adsorption processes. High molecular weight contaminants and ammonia (NH3) are removed a granular activated carbon treated with approx. 10% by weight phosphoric acid (H3PO4) (B-S Type 3032 4×6 mesh), which is expendable and is periodically refurbished. The Type 3032 granular activated carbon bed is no longer commercially available and therefore it is important to characterize the efficiency and capacity of commercially available NH3 sorbents. This paper describes the characterization of two Molecular Products LTD activated carbons: Chemsorb 1000 and Chemsorb 1425. Untreated activated carbons (e.g. Chemsorb 1000) remove contaminants by physisorption, which concentrates the contaminant within the pores of the carbon while letting air to pass through the sorbent4. Low molecular weight or polar gases (e.g. HCl, SO2, formaldehyde, and NH3) are not removed by physisorption and typically require chemisorption for removal. Treated activated carbons (e.g. Chemsorb 1425) are impregnated with a a chemical agent (e.g. phosphoric acid) that reacts with those gases, converting them to solids or salts within the carbon and removes them from the air stream. This process occurs via neutralization or catalysis reactions and adsorption capacity is exhaustedwhen the available impregnated chemicals are consumed. Moisture affects removal performance since adsorption sites within the pores are filled with water. The performance of impregnated carbons may be enhanced by moisture content because the mechanisms of contaminant removal are chemical reactions that occur in reagents contained within the pores. The adsorptive capacity data (mol/kg) of Chemsorb 1000 and 1425 for gas mixtures (ethanol, acetone, toluene, acetaldehyde, dichloromethane, and xylene) was measured with 40% relative humidity at 23 deg C air temperature. The adsorptive capacity data (mol/kg) of Chemsorb 1425 was measured using NH3 gas streams.

PubMed search filters for the study of putative outdoor air pollution determinants of disease

PubMed Central

Curti, Stefania; Gori, Davide; Di Gregori, Valentina; Farioli, Andrea; Baldasseroni, Alberto; Fantini, Maria Pia; Christiani, David C; Violante, Francesco S; Mattioli, Stefano

2016-01-01

Objectives Several PubMed search filters have been developed in contexts other than environmental. We aimed at identifying efficient PubMed search filters for the study of environmental determinants of diseases related to outdoor air pollution. Methods We compiled a list of Medical Subject Headings (MeSH) and non-MeSH terms seeming pertinent to outdoor air pollutants exposure as determinants of diseases in the general population. We estimated proportions of potentially pertinent articles to formulate two filters (one ‘more specific’, one ‘more sensitive’). Their overall performance was evaluated as compared with our gold standard derived from systematic reviews on diseases potentially related to outdoor air pollution. We tested these filters in the study of three diseases potentially associated with outdoor air pollution and calculated the number of needed to read (NNR) abstracts to identify one potentially pertinent article in the context of these diseases. Last searches were run in January 2016. Results The ‘more specific’ filter was based on the combination of terms that yielded a threshold of potentially pertinent articles ≥40%. The ‘more sensitive’ filter was based on the combination of all search terms under study. When compared with the gold standard, the ‘more specific’ filter reported the highest specificity (67.4%; with a sensitivity of 82.5%), while the ‘more sensitive’ one reported the highest sensitivity (98.5%; with a specificity of 47.9%). The NNR to find one potentially pertinent article was 1.9 for the ‘more specific’ filter and 3.3 for the ‘more sensitive’ one. Conclusions The proposed search filters could help healthcare professionals investigate environmental determinants of medical conditions that could be potentially related to outdoor air pollution. PMID:28003291

Differences in physical workload between military helicopter pilots and cabin crew.

PubMed

Van den Oord, Marieke H A; Sluiter, Judith K; Frings-Dresen, Monique H W

2014-05-01

The 1-year prevalence of regular or continuous neck pain in military helicopter pilots of the Dutch Defense Helicopter Command (DHC) is 20%, and physical work exposures have been suggested as risk factors. Pilots and cabin crew perform different tasks when flying helicopters. The aims of the current study were to compare the exposures to physical work factors between these occupations and to estimate the 1-year prevalence of neck pain in military helicopter cabin crew members. A survey was completed by almost all available helicopter pilots (n = 113) and cabin crew members (n = 61) of the DHC. The outcome measures were self-reported neck pain and exposures to nine physical work factors. Differences in the proportions of helicopter pilots and cabin crew members reporting being often exposed to the particular physical factor were assessed with the χ(2) test. The 1-year prevalence of regular or continuous neck pain among cabin crew was 28%. Significantly more cabin crew members than pilots reported being often exposed to manual material handling, performing dynamic movements with their torsos, working in prolonged bent or twisted postures with their torsos and their necks, working with their arms raised and working in awkward postures. Often exposure to prolonged sitting and dynamic movements with the neck were equally reported by almost all the pilots and cabin crew members. Flight-related neck pain is prevalent in both military helicopter pilots and cabin crew members. The exposures to neck pain-related physical work factors differ between occupations, with the cabin crew members subjected to more factors. These results have implications for preventative strategies for flight-related neck pain.

75 FR 26898 - Determination of Attainment for PM-10; Fort Hall PM-10 Nonattainment Area, Idaho

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-13

... 2009. \\9\\ FRMs are manual samplers that pull air through a filter for 24 hours (midnight to midnight... of the filter and the volume of air drawn through it. In 2008, an additional filter-based PM-10... Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing under the Clean Air Act (CAA) to determine...

40 CFR 721.10575 - 1-Propanone, 1,1'-(oxydi-4,1-phenylene)bis[2-hydroxy-2-methyl-.

Code of Federal Regulations, 2013 CFR

2013-07-01

...), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (C) NIOSH-certified powered air-purifying respirator equipped with a loose-fitting hood or helmet and high efficiency particulate air (HEPA) filters...

40 CFR 721.10575 - 1-Propanone, 1,1'-(oxydi-4,1-phenylene)bis[2-hydroxy-2-methyl-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (C) NIOSH-certified powered air-purifying respirator equipped with a loose-fitting hood or helmet and high efficiency particulate air (HEPA) filters...

122. View in subway showing air filters for unit turbinegenerator ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

122. View in subway showing air filters for unit turbine-generator unit no. 3; looking north. To the left is opening through wall which brings fresh air into the filters; this opening is above the tailrace. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

High Efficiency Particulate Air (HEPA) Filter Generation, Characterization, and Disposal Experiences at the Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coffey, D. E.

2002-02-28

High Efficiency Particulate Air filtration is an essential component of the containment and ventilation systems supporting the research and development activities at the Oak Ridge National Laboratory. High Efficiency Particulate Air filters range in size from 7.6cm (3 inch) by 10.2 cm (4 inch) cylindrical shape filters to filter array assemblies up to 2.1 m (7 feet) high by 1.5 m (5 feet) wide. Spent filters are grouped by contaminates trapped in the filter media and become one of the components in the respective waste stream. Waste minimization and pollution prevention efforts are applied for both radiological and non-radiological applications.more » Radiological applications include laboratory hoods, glove boxes, and hot cells. High Efficiency Particulate Air filters also are generated from intake or pre-filtering applications, decontamination activities, and asbestos abatement applications. The disposal avenues include sanitary/industrial waste, Resource Conservation and Recovery Act and Toxic Substance Control Act, regulated waste, solid low-level waste, contact handled transuranic, and remote handled transuranic waste. This paper discusses characterization and operational experiences associated with the disposal of the spent filters across multiple applications.« less

Infiltration of forest fire and residential wood smoke: an evaluation of air cleaner effectiveness.

PubMed

Barn, Prabjit; Larson, Timothy; Noullett, Melanie; Kennedy, Susan; Copes, Ray; Brauer, Michael

2008-09-01

Communities impacted by fine-particle air pollution (particles with an aerodynamic diameter less than 2.5 microm; PM(2.5)) from forest fires and residential wood burning require effective, evidence-based exposure-reduction strategies. Public health recommendations during smoke episodes typically include advising community members to remain indoors and the use of air cleaners, yet little information is available on the effectiveness of these measures. Our study attempted to address the following objectives: to measure indoor infiltration factor (F(inf)) of PM(2.5) from forest fires/wood smoke, to determine the effectiveness of high-efficiency particulate air (HEPA) filter air cleaners in reducing indoor PM(2.5), and to analyze the home determinants of F(inf) and air cleaner effectiveness (ACE). We collected indoor/outdoor 1-min PM(2.5) averages and 48-h outdoor PM(2.5) filter samples for 21 winter and 17 summer homes impacted by wood burning and forest fire smoke, respectively, during 2004-2005. A portable HEPA filter air cleaner was operated indoors with the filter removed for one of two sampling days. Particle F(inf) and ACE were calculated for each home using a recursive model. We found mean F(inf)+/-SD was 0.27+/-0.18 and 0.61+/-0.27 in winter (n=19) and summer (n=13), respectively, for days when HEPA filters were not used. Lower F(inf)+/-SD values of 0.10+/-0.08 and 0.19+/-0.20 were found on corresponding days when HEPA filters were in place. Mean+/-SD ACE ([F(inf) without filter-F(inf) with filter]/F(inf) without filter) in winter and summer were 55+/-38% and 65+/-35%, respectively. Number of windows and season predicted F(inf) (P<0.001). No significant predictors of ACE were identified. Our findings show that remaining indoors combined with use of air cleaner can effectively reduce PM(2.5) exposure during forest fires and residential wood burning.

Mold occurring on the air cleaner high-efficiency particulate air filters used in the houses of child patients with atopic dermatitis.

PubMed

Kim, Seong Hwan; Ahn, Geum Ran; Son, Seung Yeol; Bae, Gwi-Nam; Yun, Yeo Hong

2014-09-01

Fungi are the known sources of irritation associated with atopic diseases (e.g., asthma, allergic rhinoconjunctivitis, and atopic eczema). To quantitatively estimate their presence in the indoor environment of atopic dermatitis-inflicted child patient's houses (ADCPHs), the high-efficiency particulate air (HEPA) filters installed inside the air cleaners of three different ADCPHs were investigated for the presence of mold. The air cleaner HEPA filters obtained from the three different ADCPHs were coded as HEPA-A, -B, and -C, respectively, and tested for the presence of mold. The colony forming units (CFUs) corresponding to the HEPA-A, -B, and -C filters were estimated to be 6.51 × 10(2) ± 1.50 × 10(2) CFU/cm(2), 8.72 × 10(2) ± 1.69 × 10(2) CFU/cm(2), and 9.71 × 10(2) ± 1.35 × 10(2) CFU/cm(2), respectively. Aspergillus, Penicillium, Alternaria, Cladosporium, Trichoderma, and other fungal groups were detected in the 2,494 isolates. The distribution of these fungal groups differed among the three filters. Cladosporium was the major fungal group in filters HEPA-A and -C, whereas Penicillium was the major fungal group in the filter HEPA-B. Nine fungal species, including some of the known allergenic species, were identified in these isolates. Cladosporium cladosporioides was the most common mold among all the three filters. This is the first report on the presence of fungi in the air cleaner HEPA filters from ADCPHs in Korea.

Quantitative filter forensics for indoor particle sampling.

PubMed

Haaland, D; Siegel, J A

2017-03-01

Filter forensics is a promising indoor air investigation technique involving the analysis of dust which has collected on filters in central forced-air heating, ventilation, and air conditioning (HVAC) or portable systems to determine the presence of indoor particle-bound contaminants. In this study, we summarize past filter forensics research to explore what it reveals about the sampling technique and the indoor environment. There are 60 investigations in the literature that have used this sampling technique for a variety of biotic and abiotic contaminants. Many studies identified differences between contaminant concentrations in different buildings using this technique. Based on this literature review, we identified a lack of quantification as a gap in the past literature. Accordingly, we propose an approach to quantitatively link contaminants extracted from HVAC filter dust to time-averaged integrated air concentrations. This quantitative filter forensics approach has great potential to measure indoor air concentrations of a wide variety of particle-bound contaminants. Future studies directly comparing quantitative filter forensics to alternative sampling techniques are required to fully assess this approach, but analysis of past research suggests the enormous possibility of this approach. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Numerical study of canister filters with alternatives filter cap configurations

NASA Astrophysics Data System (ADS)

Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

2017-09-01

Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

Indoor-outdoor relationships of PM2.5 in four residential dwellings in winter in the Yangtze River Delta, China.

PubMed

Wang, Fang; Meng, Dan; Li, Xiuwei; Tan, Junjie

2016-08-01

Indoor and outdoor air PM2.5 concentrations in four residential dwellings characterized with different building envelope air tightness levels and HVAC-filter configurations in Yangtze River Delta (YRD) were measured during winter periods in 2014-2015. Steady-state models for indoor PM2.5 were developed for each of the tested dwellings, based on mass balance equation. The indoor air PM2.5 concentrations in the four tested apartments were significantly different. The lowest geometric mean values of indoor air PM2.5 concentrations, I/O ratios, and infiltration factor were observed in D3 with high air tightness and without HVAC-filter system (26.0 μg/m(3), 0.197, and 0.167, respectively), while the highest geometric mean values of indoor air PM2.5 concentrations, I/O ratios, and infiltration factor were observed in D1 (64.9 μg/m(3), 0.876, and 0.867, respectively). For apartment D1 with normal air tightness and without any HVAC-filter system, indoor air PM2.5 concentrations were significantly correlated with outdoor PM2.5 concentrations, especially in severe ambient pollution days, when closed windows can only play a very weak role on the decline of indoor PM2.5 concentrations. With the enhancement of building air tightness, the indoor air PM2.5 concentrations can be decreased effectively and don't vary as much in response to fluctuations in ambient concentrations. For buildings with normal air tightness, the use of HVAC-filter combinations will decrease the indoor PM2.5 significantly. However, for buildings with enhanced air tightness, the only use of fresh makeup air supply system with filter may increase the indoor PM2.5 concentrations. The improvement of filter efficiency for both fresh makeup air and indoor recirculated air are very important. However, purifiers for indoor recirculated air were highly recommended for all buildings. Copyright © 2016 Elsevier Ltd. All rights reserved.