77 FR 74372 - Revisions to the California State Implementation Plan, South Coast Air Quality Management District

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-14

... of South Coast Air Quality Management District (SCAQMD) Rule 317, ``Clean Air Act Non- Attainment Fee... determined that SCAQMD's alternative fee-equivalent program is not less stringent than the program required by section 185, and, therefore, is approvable as an equivalent alternative program, consistent with...

Control Techniques for Particulate Air Pollutants.

ERIC Educational Resources Information Center

National Air Pollution Control Administration (DHEW), Washington, DC.

Included is a comprehensive review of the approaches commonly recommended for controlling the sources of particulate air pollution. Not all possible combinations of control techniques that might bring about more stringent control of each individual source are reviewed. The many agricultural, commercial, domestic, industrial, and municipal…

Air Quality and Health Benefits of China's Recent Stringent Environmental Policy

NASA Astrophysics Data System (ADS)

Zheng, Y.; Xue, T.; Zhang, Q.; Geng, G.; He, K.

2016-12-01

Aggressive emission control measures were taken by China's central and local governments after the promulgation of the "Air Pollution Prevention and Control Action Plan" in 2013. We evaluated the air quality and health benefits of this ever most stringent air pollution control policy during 2013-2015 by utilizing a two-stage data fusion model and newly-developed cause-specific integrated exposure-response functions (IER) developed for the Global Burden of Disease (GBD). The two-stage data fusion model predicts spatiotemporal continuous PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) concentrations by integrating satellite-derived aerosol optical depth (AOD) measurements, PM2.5 concentrations from measurement and air quality model, and other ancillary information. During the years of analysis, PM2.5 concentration dropped significantly on national average and over heavily polluted regions as identified by Mann-Kendall analysis. The national PM2.5-attributable mortality decreased by 72.8 (95% CI: 59.4, 85.2) thousand (6%) from 1.23 (95% CI: 1.06, 1.39) million in 2013 to 1.15 (95% CI: 0.98, 1.31) million in 2015 due to considerable reduction (i.e. 18%) of population-weighted PM2.5 from 61.4 to 50.5 µg/m3. Meteorological variations between 2013 and 2015 were estimated to raise the PM2.5 levels by 0.24 µg/m3 and national mortality by 2.1 (95% CI: 1.6, 2.6) thousand through sensitivity tests, which implies the dominant role of anthropogenic impacts on PM2.5 abatement and attributable mortality reduction. Our study affirms the effectiveness of China's recent air quality policy, however, due to the possible supralinear shape of C-R functions, health benefits induced by air quality improvement in these years are limited. We therefore appeal for continuous implementation of current policies and further stringent measures from both air quality improvement and public health protection perspectives.

Sustainable materials management using the Leaching Environmental Assessment Framework test methods

EPA Science Inventory

The need for improved leach tests became a priority due to adoption of more stringent air pollution control at U.S. coal-fired power plants resulting in the preferential partitioning of mercury (Hg) and other pollutants to fly ash and other air pollution control residues. Fly ash...

Multi-Model Comparison of Lateral Boundary Contributions to Surface Ozone Over the United States

EPA Science Inventory

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. The third phase of the Air Qua...

Multi-model Comparison of Lateral Boundary Contributions to Ozone Concentrations over the United States

EPA Science Inventory

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. The third phase of the Air Qua...

A STRINGENT COMPARISON OF SAMPLING AND ANALYSIS METHODS FOR VOCS IN AMBIENT AIR

EPA Science Inventory

A carefully designed study was conducted during the summer of 1998 to simultaneously collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. A total of 32 1-h sample sets we...

Multi-model Comparison of Lateral Boundary Contributions to Ozone Concentrations over the United States (CM

EPA Science Inventory

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. The third phase of the Air Qua...

Multi-model Comparison of Lateral Boundary Contributions to Ozone Concentrations over the United States (CMAS Presentation)

EPA Science Inventory

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. The third phase of the Air Qua...

[Index assessment of airborne VOCs pollution in automobile for transporting passengers].

PubMed

Chen, Xiao-Kai; Cheng, He-Ming; Luo, Hui-Long

2013-12-01

Car for transporting passenger is the most common means of transport and in-car airborne volatile organic compounds (VOCs) cause harm to health. In order to analyze the pollution levels of benzene, toluene, ethylbenzene, xylenes, styrene and TVOC, index evaluation method was used according to the domestic and international standards of indoor and in-car air quality (IAQ). For Chinese GB/T 18883-2002 IAQ Standard, GB/T 17729-2009 Hygienic Standard for the Air Quality inside Long Distance Coach, GB/T 27630-2011 Guideline for Air Quality Assessment of Passenger Car, IAQ standard of South Korea, Norway, Japan and Germany, the heaviest pollution of VOCs in passenger car was TVOC, TVOC, benzene, benzene, TVOC, toluene and TVOC, respectively, the average pollution grade of automotive IAQ was median pollution, median pollution, clean, light pollution, median pollution, clean and heavy pollution, respectively. Index evaluation can effectively analyze vehicular interior air quality, and the result has a significant difference with different standards; German standard is the most stringent, while Chinese GB/T 18883-2002 standard is the relatively stringent and GB/T 27630-2011 is the most relaxed.

Air quality improvements and health benefits from China’s clean air action since 2013

NASA Astrophysics Data System (ADS)

Zheng, Yixuan; Xue, Tao; Zhang, Qiang; Geng, Guannan; Tong, Dan; Li, Xin; He, Kebin

2017-11-01

Aggressive emission control measures were taken by the Chinese government after the promulgation of the ‘Air Pollution Prevention and Control Action Plan’ in 2013. Here we evaluated the air quality and health benefits associated with this stringent policy during 2013-2015 by using surface PM2.5 concentrations estimated from a three-stage data fusion model and cause-specific integrated exposure-response functions. The population-weighted annual mean PM2.5 concentrations decreased by 21.5% over China during 2013-2015, reducing from 60.5 in 2013 to 47.5 μg m-3 in 2015. Subsequently, the national PM2.5-attributable mortality decreased from 1.22 million (95% CI: 1.05, 1.37) in 2013 to 1.10 million (95% CI: 0.95, 1.25) in 2015, which is a 9.1% reduction. The limited health benefits compared to air quality improvements are mainly due to the supralinear responses of mortality to PM2.5 over the high concentration end of the concentration-response functions. Our study affirms the effectiveness of China’s recent air quality policy; however, due to the nonlinear responses of mortality to PM2.5 variations, current policies should remain in place and more stringent measures should be implemented to protect public health.

Air Force construction automation/robotics

NASA Technical Reports Server (NTRS)

Nease, AL; Dusseault, Christopher

1994-01-01

The Air Force has several unique requirements that are being met through the development of construction robotic technology. The missions associated with these requirements place construction/repair equipment operators in potentially harmful situations. Additionally, force reductions require that human resources be leveraged to the maximum extent possible and that more stringent construction repair requirements push for increased automation. To solve these problems, the U.S. Air Force is undertaking a research and development effort at Tyndall AFB, FL to develop robotic teleoperation, telerobotics, robotic vehicle communications, automated damage assessment, vehicle navigation, mission/vehicle task control architecture, and associated computing environment. The ultimate goal is the fielding of robotic repair capability operating at the level of supervised autonomy. The authors of this paper will discuss current and planned efforts in construction/repair, explosive ordnance disposal, hazardous waste cleanup, fire fighting, and space construction.

Eco-driving: behavioural pattern change in Polish passenger vehicle drivers

NASA Astrophysics Data System (ADS)

Czechowski, Piotr Oskar; Oniszczuk-Jastrząbek, Aneta; Czuba, Tomasz

2018-01-01

In Poland, as in the rest of Europe, air quality depends primarily on emissions from municipal, domestic and road transport sources. The problems of appropriate air quality are especially important within urban areas due to numerous sources of emissions being concentrated in relatively small spaces in both large cities and small/medium-sized towns. Due to the steadily increasing share of urban population in the overall number of population, the issue of providing clean air will over the years become a more significant problem for human health, and therefore a stronger incentive to intensify research. The key challenge faced by a modern society is, therefore, to limit harmful substance emissions in order to minimise the contribution of transport to pollution and health hazards. Increasingly stringent emission standards are being imposed on car manufacturers; on the other hand, scant regard is paid to the issue of drivers, i.e. how they can help reduce emissions and protect their life and health by applying eco-driving rules.

77 FR 18477 - Energy Conservation Program: Energy Conservation Standards for Battery Chargers and External...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-27

... Interstate Rule (CAIR, 70 FR 25162 (May 12, 2005)), but not the Clean Air Mercury Rule (CAMR, 70 FR 28606 (May 18, 2005)). Subsequent regulations, including the finalized CAIR replacement rule, the Cross-State... Air Interstate Rule (CAIR, which has a similar structure, but with less stringent budgets and less...

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

Code of Federal Regulations, 2013 CFR

2013-07-01

... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

77 FR 38725 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-29

... of aerosol adhesives containing methylene chloride, perchloroethylene, or trichloroethylene. --A..., perchloroethylene, or trichloroethylene. This section is at least as stringent as the OTC model rule, and therefore...

ARI's Views on ANSI S12.60-2002.

ERIC Educational Resources Information Center

Darbeau, Michele

2003-01-01

States the position of the Air-Conditioning and Refrigeration Institute (ARI) toward ANSI Standard 12.60, which addresses classroom acoustics. Explains why it believes the standard creates an overly stringent requirement. (EV)

Abatement of tropospheric ozone: effects of strategies to improve air quality on public health and other sectors.

PubMed

Guest, C S; Morgan, P; Moss, J R; Woodward, A J; McMichael, A J

1996-06-01

The National Health and Medical Research Council's air quality goal for ozone in the troposphere (near the earth's surface) is 0.12 parts per million (ppm), averaged over one hour, similar to the United States standard, but less stringent than the guideline for Europe. We aimed to identify the environmental, economic and social changes that would be associated with changing the goal. Methods included literature review, economic assessments and group interviews. The group to benefit from lower exposures may include outdoor workers, school children and people not in regular day-time work indoors, because ozone is most prevalent during the daylight hours of the warmer months. A lower level could improve the yield of some crops. The causes and effects of tropospheric ozone are not appreciated except among groups with relevant commercial, industrial or scientific experience. However, the consultations identified frustration about the social problems caused by dependence on private motor vehicles. Short-term costs of compliance with a more stringent goal would fall principally on the users of transport. The value of the benefits was enough for many to support making the ozone goal more stringent, but those who required a demonstration of financial benefit (even including savings of health care costs) did not support any change to the goal. Based primarily on averted detriment to health, we recommend the more stringent level of 0.08 ppm (one-hour average) as the goal for the year 2005 in Australia and elsewhere. The addition of a goal with longer averaging time is also proposed.

Avoiding Title V permitting pitfalls

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

Laswell, D.L.

1993-04-01

Title V of the 1990 Clean Air Act Amendments requires states to implement new air operating permit programs. States have a great deal of flexibility in developing their permit programs. Industry should work now to ensure that state programs contain the favorable aspects of the federal regulations and do not contain more stringent requirements that are not required under the Clean Air Act. This article outlines areas of the permit program that have the potential to handicap industry`s ability to expand.

Policy Analysis: Valuation of Ecosystem Services in the Southern Appalachian Mountains.

PubMed

Banzhaf, H Spencer; Burtraw, Dallas; Criscimagna, Susie Chung; Cosby, Bernard J; Evans, David A; Krupnick, Alan J; Siikamäki, Juha V

2016-03-15

This study estimates the economic value of an increase in ecosystem services attributable to the reduced acidification expected from more stringent air pollution policy. By integrating a detailed biogeochemical model that projects future ecological recovery with economic methods that measure preferences for specific ecological improvements, we estimate the economic value of ecological benefits from new air pollution policies in the Southern Appalachian ecosystem. Our results indicate that these policies generate aggregate benefits of about $3.7 billion, or about $16 per year per household in the region. The study provides currently missing information about the ecological benefits from air pollution policies that is needed to evaluate such policies comprehensively. More broadly, the study also illustrates how integrated biogeochemical and economic assessments of multidimensional ecosystems can evaluate the relative benefits of different policy options that vary by scale and across ecosystem attributes.

Innovative ventilation system for animal anatomy laboratory

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

Lacey, D.R.; Smith, D.C.

1997-04-01

A unique ventilation system was designed and built to reduce formaldehyde fumes in the large animal anatomy lab at the Vet Medical Center at Cornell University. The laboratory includes four rooms totaling 5,500 ft{sup 2}. The main room has 2,300 ft{sup 2} and houses the laboratory where up to 60 students dissect as many as 12 horses at a time. Other rooms are a cold storage locker, an animal preparation room and a smaller lab for specialized instruction. The large animal anatomy laboratory has a history of air quality complaints despite a fairly high ventilation rate of over 10 airmore » changes/hour. The horses are embalmed, creating a voluminous source of formaldehyde and phenol vapors. Budget constraints and increasingly stringent exposure limits for formaldehyde presented a great challenge to design a ventilation system that yields acceptable air quality. The design solution included two innovative elements: air-to-air heat recovery, and focused ventilation.« less

The Streptococcus agalactiae Stringent Response Enhances Virulence and Persistence in Human Blood

PubMed Central

Hooven, Thomas A.; Catomeris, Andrew J.; Bonakdar, Maryam; Tallon, Luke J.; Santana-Cruz, Ivette; Ott, Sandra; Daugherty, Sean C.; Tettelin, Hervé

2017-01-01

ABSTRACT Streptococcus agalactiae (group B Streptococcus [GBS]) causes serious infections in neonates. We previously reported a transposon sequencing (Tn-seq) system for performing genomewide assessment of gene fitness in GBS. In order to identify molecular mechanisms required for GBS to transition from a mucosal commensal lifestyle to bloodstream invasion, we performed Tn-seq on GBS strain A909 with human whole blood. Our analysis identified 16 genes conditionally essential for GBS survival in blood, of which 75% were members of the capsular polysaccharide (cps) operon. Among the non-cps genes identified as conditionally essential was relA, which encodes an enzyme whose activity is central to the bacterial stringent response—a conserved adaptation to environmental stress. We used blood coincubation studies of targeted knockout strains to confirm the expected growth defects of GBS deficient in capsule or stringent response activation. Unexpectedly, we found that the relA knockout strains demonstrated decreased expression of β-hemolysin/cytolysin, an important cytotoxin implicated in facilitating GBS invasion. Furthermore, chemical activation of the stringent response with serine hydroxamate increased β-hemolysin/cytolysin expression. To establish a mechanism by which the stringent response leads to increased cytotoxicity, we performed transcriptome sequencing (RNA-seq) on two GBS strains grown under stringent response or control conditions. This revealed a conserved decrease in the expression of genes in the arginine deiminase pathway during stringent response activation. Through coincubation with supplemental arginine and the arginine antagonist canavanine, we show that arginine availability is a determinant of GBS cytotoxicity and that the pathway between stringent response activation and increased virulence is arginine dependent. PMID:29109175

78 FR 29815 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-21

...This action would establish more stringent vehicle emissions standards and reduce the sulfur content of gasoline beginning in 2017, as part of a systems approach to addressing the impacts of motor vehicles and fuels on air quality and public health. The proposed gasoline sulfur standard would make emission control systems more effective for both existing and new vehicles, and would enable more stringent vehicle emissions standards. The proposed vehicle standards would reduce both tailpipe and evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles. This would result in significant reductions in pollutants such as ozone, particulate matter, and air toxics across the country and help state and local agencies in their efforts to attain and maintain health-based National Ambient Air Quality Standards. Motor vehicles are an important source of exposure to air pollution both regionally and near roads. These proposed vehicle standards are intended to harmonize with California's Low Emission Vehicle program, thus creating a federal vehicle emissions program that would allow automakers to sell the same vehicles in all 50 states. The proposed vehicle standards would be implemented over the same timeframe as the greenhouse gas/fuel efficiency standards for light-duty vehicles, as part of a comprehensive approach toward regulating emissions from motor vehicles.

Historic and future trends of vehicle emissions in Beijing, 1998-2020: A policy assessment for the most stringent vehicle emission control program in China

NASA Astrophysics Data System (ADS)

Zhang, Shaojun; Wu, Ye; Wu, Xiaomeng; Li, Mengliang; Ge, Yunshan; Liang, Bin; Xu, Yueyun; Zhou, Yu; Liu, Huan; Fu, Lixin; Hao, Jiming

2014-06-01

As a pioneer in controlling vehicle emissions within China, Beijing released the Clean Air Action Plan 2013-2017 document in August 2013 to improve its urban air quality. It has put forward this plan containing the most stringent emission control policies and strategies to be adopted for on-road vehicles of Beijing. This paper estimates the historic and future trends and uncertainties in vehicle emissions of Beijing from 1998 to 2020 by applying a new emission factor model for the Beijing vehicle fleet (EMBEV). Our updated results show that total emissions of CO, THC, NOx and PM2.5 from the Beijing vehicle fleet are 507 (395-819) kt, 59.1 (41.2-90.5) kt, 74.7 (54.9-103.9) kt and 2.69 (1.91-4.17) kt, respectively, at a 95% confidence level. This represents significant reductions of 58%, 59%, 31% and 62%, respectively, relative to the total vehicle emissions in 1998. The past trends clearly posed a challenge to NOx emission mitigation for the Beijing vehicle fleet, especially in light of those increasing NOx emissions from heavy-duty diesel vehicles (HDDVs) which have partly offset the reduction benefit from light-duty gasoline vehicles (LDGVs). Because of recently announced vehicle emission controls to be adopted in Beijing, including tighter emissions standards, limitations on vehicle growth by more stringent license control, promotion of alternative fuel technologies (e.g., natural gas) and the scrappage of older vehicles, estimated vehicle emissions in Beijing will continue to be mitigated by 74% of CO, 68% of THC, 56% of NOx and 72% of PM2.5 in 2020 compared to 2010 levels. Considering that many of the megacities in China are facing tremendous pressures to mitigate emissions from on-road vehicles, our assessment will provide a timely case study of significance for policy-makers in China.

40 CFR 1054.701 - General provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 1054.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... include engines or equipment certified for California if California has more stringent emission standards for these products or if your products generate or use emission credits under the California program...

40 CFR 1051.701 - General provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 1051.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... for California if it has more stringent emission standards for these vehicles or those vehicles generate or use emission credits under the California program. (5) Any other vehicles, where we indicate...

40 CFR 1054.701 - General provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 1054.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... include engines or equipment certified for California if California has more stringent emission standards for these products or if your products generate or use emission credits under the California program...

40 CFR 1054.701 - General provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 1054.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... include engines or equipment certified for California if California has more stringent emission standards for these products or if your products generate or use emission credits under the California program...

40 CFR 1054.701 - General provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 1054.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... include engines or equipment certified for California if California has more stringent emission standards for these products or if your products generate or use emission credits under the California program...

40 CFR 1051.701 - General provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 1051.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... for California if it has more stringent emission standards for these vehicles or those vehicles generate or use emission credits under the California program. (5) Any other vehicles, where we indicate...

40 CFR 1051.701 - General provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 1051.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... for California if it has more stringent emission standards for these vehicles or those vehicles generate or use emission credits under the California program. (5) Any other vehicles, where we indicate...

40 CFR 1051.701 - General provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 1051.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... for California if it has more stringent emission standards for these vehicles or those vehicles generate or use emission credits under the California program. (5) Any other vehicles, where we indicate...

40 CFR 1054.701 - General provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 1054.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... include engines or equipment certified for California if California has more stringent emission standards for these products or if your products generate or use emission credits under the California program...

40 CFR 1051.701 - General provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 1051.701 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... for California if it has more stringent emission standards for these vehicles or those vehicles generate or use emission credits under the California program. (5) Any other vehicles, where we indicate...

Tracking Continental Scale Background Ozone with CMAQ

EPA Science Inventory

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. Modeling techniques readily av...

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region.

PubMed

Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wu, Xiaomeng; Shu, Jiawei; Hao, Jiming

2017-01-01

The Yangtze River Delta (YRD) region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality. Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants (e.g., CO, HC and PM 2.5 ) in the YRD region. Even in Shanghai, where the emission control implemented are more stringent than in Jiangsu and Zhejiang, we observed little to no reduction in NOx emissions from 2000 to 2010. Emission-reduction targets for HC, NOx and PM 2.5 are determined using a response surface modeling tool for better air quality. We design city-specific emission control strategies for three vehicle-populated cities in the YRD region: Shanghai and Nanjing and Wuxi in Jiangsu. Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards, the limitation of vehicle population and usage, and the scrappage of older vehicles is applied, Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020. Therefore, additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles. Copyright © 2016. Published by Elsevier B.V.

Particulate matter emissions from combustion of wood in district heating applications

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

Ghafghazi, S.; Sowlati, T.; Sokhansanj, Shahabaddine

2011-01-01

The utilization of wood biomass to generate district heat and power in communities that have access to this energy source is increasing. In this paper the effect of wood fuel properties, combustion condition, and flue gas cleaning system on variation in the amount and formation of particles in the flue gas of typical district heating wood boilers are discussed based on the literature survey. Direct measurements of particulate matter (PM) emissions from wood boilers with district heating applications are reviewed and presented. Finally, recommendations are given regarding the selection of wood fuel, combustion system condition, and flue gas cleaning systemmore » in district heating systems in order to meet stringent air quality standards. It is concluded that utilization of high quality wood fuel, such as wood pellets produced from natural, uncontaminated stem wood, would generate the least PM emissions compared to other wood fuel types. Particulate matter emissions from grate burners equipped with electrostatic precipitators when using wood pellets can be well below stringent regulatory emission limit such as particulate emission limit of Metro Vancouver, Canada.« less

Air Force construction automation/robotics

NASA Technical Reports Server (NTRS)

Nease, A. D.; Alexander, E. F.

1993-01-01

The Air Force has several missions which generate unique requirements that are being met through the development of construction robotic technology. One especially important mission will be the conduct of Department of Defense (DOD) space activities. Space operations and other missions place construction/repair equipment operators in dangerous environments and potentially harmful situations. Additionally, force reductions require that human resources be leveraged to the maximum extent possible, and more stringent construction repair requirements push for increased automation. To solve these problems, the U.S. Air Force is undertaking a research and development effort at Tyndall AFB, FL, to develop robotic construction/repair equipment. This development effort involves the following technologies: teleoperation, telerobotics, construction operations (excavation, grading, leveling, tool change), robotic vehicle communications, vehicle navigation, mission/vehicle task control architecture, and associated computing environment. The ultimate goal is the fielding of a robotic repair capability operating at the level of supervised autonomy. This paper will discuss current and planned efforts in space construction/repair, explosive ordnance disposal, hazardous waste cleanup, and fire fighting.

Stringency and relaxation among the halobacteria.

PubMed Central

Cimmino, C; Scoarughi, G L; Donini, P

1993-01-01

Accumulation of stable RNA and production of guanosine polyphosphates (ppGpp and pppGpp) were studied during amino acid starvation in four species of halobacteria. In two of the four species, stable RNA was under stringent control, whereas one of the remaining two species was relaxed and the other gave an intermediate phenotype. The stringent reaction was reversed by anisomycin, an effect analogous to the chloroamphenicol-induced reversal of stringency in the eubacteria. During the stringent response, neither ppGpp nor pppGpp accumulation took place during starvation. In both growing and starved cells a very low basal level of the two polyphosphates appeared to be present. In the stringent species the intracellular concentration of GTP did not diminish but actually increased during the course of the stringent response. These data demonstrate that (i) wild-type halobacteria can have either the stringent or the relaxed phenotype (all wild-type eubacteria tested have been shown to be stringent); (ii) stringency in the halobacteria is dependent on the deaminoacylation of tRNA, as in the eubacteria; and (iii) in the halobacteria, ppGpp is not an effector of stringent control over stable-RNA synthesis. Images PMID:7691798

Environmental Policy--a Priority for Schools in the '90s.

ERIC Educational Resources Information Center

Ehrhardt, Cathryn

1989-01-01

A transformation of public attitudes on the environment has resulted in more stringent standards on almost all school programs for hazardous waste management, air quality, groundwater, and emergency planning and response. A comprehensive environmental risk reduction and management policy should highlight the potential for environmental risks in…

40 CFR 52.1623 - Conditional approval.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Mexico § 52.1623 Conditional approval. (a) General Conformity. (1) A letter, dated April 22, 1998, from the Chief of Air Quality Bureau New Mexico... to withdraw its approval. The FAA had commented that New Mexico was more stringent than EPA, since...

40 CFR 52.1623 - Conditional approval.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Mexico § 52.1623 Conditional approval. (a) General Conformity. (1) A letter, dated April 22, 1998, from the Chief of Air Quality Bureau New Mexico... to withdraw its approval. The FAA had commented that New Mexico was more stringent than EPA, since...

Characterization of cotton gin particulate matter emissions – project plan

USDA-ARS?s Scientific Manuscript database

In 2006, EPA implemented a more stringent standard for particulate matter with an effective diameter less than 2.5 microns (PM2.5). The implementation timeline for this standard will vary by state/district regulatory agency. For example, the San Joaquin Valley Air Pollution Control District, has pro...

Characterization of cotton gin particulate matter emissions - project plan

USDA-ARS?s Scientific Manuscript database

In 2006, EPA implemented a more stringent standard for particulate matter with an effective diameter less than 2.5 microns (PM2.5). The implementation time line for this standard will vary by state/district regulatory agency. For example, the San Joaquin Valley Air Pollution Control District has pro...

41 CFR 302-16.2 - What are miscellaneous expenses?

Code of Federal Regulations, 2012 CFR

2012-07-01

... relocating that are not covered by other relocation benefits detailed in Chapter 302. (b) Expenses allowable... use taxes imposed when bringing vehicles into certain jurisdictions Transportation of pets The only... other house pets, as well as costs due to stringent air carrier rules. Other animals (horses, fish...

41 CFR 302-16.2 - What are miscellaneous expenses?

Code of Federal Regulations, 2014 CFR

2014-07-01

... relocating that are not covered by other relocation benefits detailed in chapter 302. (b) Expenses allowable... use taxes imposed when bringing vehicles into certain jurisdictions Transportation of pets The only... other house pets, as well as costs due to stringent air carrier rules. Other animals (horses, fish...

41 CFR 302-16.2 - What are miscellaneous expenses?

Code of Federal Regulations, 2013 CFR

2013-07-01

... relocating that are not covered by other relocation benefits detailed in Chapter 302. (b) Expenses allowable... use taxes imposed when bringing vehicles into certain jurisdictions Transportation of pets The only... other house pets, as well as costs due to stringent air carrier rules. Other animals (horses, fish...

Best Practices for Gauging Evidence of Causality in Air Pollution Epidemiology.

PubMed

Dominici, Francesca; Zigler, Corwin

2017-12-15

The contentious political climate surrounding air pollution regulations has brought some researchers and policy-makers to argue that evidence of causality is necessary before implementing more stringent regulations. Recently, investigators in an increasing number of air pollution studies have purported to have used "causal analysis," generating the impression that studies not explicitly labeled as such are merely "associational" and therefore less rigorous. Using 3 prominent air pollution studies as examples, we review good practices for how to critically evaluate the extent to which an air pollution study provides evidence of causality. We argue that evidence of causality should be gauged by a critical evaluation of design decisions such as 1) what actions or exposure levels are being compared, 2) whether an adequate comparison group was constructed, and 3) how closely these design decisions approximate an idealized randomized study. We argue that air pollution studies that are more scientifically rigorous in terms of the decisions made to approximate a randomized experiment are more likely to provide evidence of causality and should be prioritized among the body of evidence for regulatory review accordingly. Our considerations, although presented in the context of air pollution epidemiology, can be broadly applied to other fields of epidemiology. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Polybrominated diphenyl ether (PBDE) concentrations and resulting exposure in homes in California: relationships among passive air, surface wipe and dust concentrations, and temporal variability

EPA Science Inventory

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam, electronics, and other home furnishings. A field study was conducted that enrolled 139 households from California, which has had more stringent flame retardant requirements than other countries...

76 FR 28318 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

... hydrocarbons (THC), and particulate matter (PM) from new and existing cement kilns located at major and area... appreciably is the floor for THC, which would become significantly more stringent because the revised data base would reflect cement kilns experiencing less variability in THC emissions.\\10\\ Given the minimal...

40 CFR Appendix A to Part 58 - Quality Assurance Requirements for SLAMS, SPMs and PSD Air Monitoring

Code of Federal Regulations, 2010 CFR

2010-07-01

... quality system in terms of the organizational structure, functional responsibilities of management and... more stringent requirements. Monitoring organizations may, based on their quality objectives, develop... infrequent work with EPA funds may combine the QMP with the QAPP based on negotiations with the funding...

Emission and distribution of fumigants as affected by soil moistures in three different textured soils

USDA-ARS?s Scientific Manuscript database

Stringent environmental regulations are being developed to control the emission of soil fumigants to reduce air pollution. Water application is a low-cost strategy for fumigant emission control and applicable for a wide range of commodity groups, especially those with low profit margins. Although it...

EPA may modify Du Pont waiver for methanol fuel blends

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

Anderson, E.V.

1985-09-02

The Environmental Protection Agency (EPA) granted a Clean Air ACt waiver to DuPont's blendstock of methanol and other cosolvent alcohols for use in unleaded gasoline. The waiver included some stringent fuel volatility requirements to control evaporative emissions that have kept the waiver from becoming the marketing tool for fuel alcohols that everyone expected it to be. EPA seems willing to amend the waiver as long as evaporative emissions controls are kept, but there are some difficult procedural issues to resolve first. To date, only small amounts of alcohol blends have been sold under the DuPont waiver because the blendstock tendsmore » to increase the volatility of gasoline.« less

On-road vehicle emissions and their control in China: A review and outlook.

PubMed

Wu, Ye; Zhang, Shaojun; Hao, Jiming; Liu, Huan; Wu, Xiaomeng; Hu, Jingnan; Walsh, Michael P; Wallington, Timothy J; Zhang, K Max; Stevanovic, Svetlana

2017-01-01

The large (26-fold over the past 25years) increase in the on-road vehicle fleet in China has raised sustainability concerns regarding air pollution prevention, energy conservation, and climate change mitigation. China has established integrated emission control policies and measures since the 1990s, including implementation of emission standards for new vehicles, inspection and maintenance programs for in-use vehicles, improvement in fuel quality, promotion of sustainable transportation and alternative fuel vehicles, and traffic management programs. As a result, emissions of major air pollutants from on-road vehicles in China have peaked and are now declining despite increasing vehicle population. As might be expected, progress in addressing vehicle emissions has not always been smooth and challenges such as the lack of low sulfur fuels, frauds over production conformity and in-use inspection tests, and unreliable retrofit programs have been encountered. Considering the high emission density from vehicles in East China, enhanced vehicle, fuel and transportation strategies will be required to address vehicle emissions in China. We project the total vehicle population in China to reach 400-500 million by 2030. Serious air pollution problems in many cities of China, in particular high ambient PM 2.5 concentration, have led to pressure to accelerate the progress on vehicle emission reduction. A notable example is the draft China 6 emission standard released in May 2016, which contains more stringent emission limits than those in the Euro 6 regulations, and adds a real world emission testing protocol and a 48-h evaporation testing procedure including diurnal and hot soak emissions. A scenario (PC[1]) considered in this study suggests that increasingly stringent standards for vehicle emissions could mitigate total vehicle emissions of HC, CO, NO X and PM 2.5 in 2030 by approximately 39%, 57%, 59% and 79%, respectively, compared with 2013 levels. With additional actions to control the future light-duty passenger vehicle population growth and use, and introduce alternative fuels and new energy vehicles, the China total vehicle emissions of HC, CO, NO X and PM 2.5 in 2030 could be reduced by approximately 57%, 71%, 67% and 84%, respectively, (the PC[2] scenario) relative to 2013. This paper provides detailed policy roadmaps and technical options related to these future emission reductions for governmental stakeholders. Copyright © 2016 Elsevier B.V. All rights reserved.

76 FR 46842 - Notice of Lodging of Consent Decree Under the Clean Air Act

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-03

..., Section 301(a) of the Clean Water Act, 42 U.S.C. 1311(a), and Section 3005(a) of the Resource Conservation..., Michigan. Under the Consent Decree, Dow will implement an Enhanced Leak Detection and Repair (``LDAR'') Program which imposes leak monitoring and repair requirements more stringent than existing LDAR...

77 FR 38501 - Approval and Promulgation of Implementation Plans; State of Georgia; Regional Haze State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-28

... no additional emissions controls for some pollutants but does not specify an appropriately stringent... controls from examination based on economic factors alone. Response 4: The Commenter overstates the scope... beyond the control of the user (see, e.g., 40 CFR 60.7575; Georgia Air Quality Control Rules 391-3-1-.02...

An Estimation of Mobile Emissions Reduction from Using Electronic Toll Collection in the Baltimore Metropolitan Area: A Case Study of the Fort McHenry Tunnel Toll Plaza

DOT National Transportation Integrated Search

2000-03-01

The Baltimore Metropolitan Area is classified as a severe nonattainment area under the Clean Air Act Amendments of 1990. Consequently, it operates on a stringent emissions budget and is mandated to embark on mitigation measures. The area has been agg...

40 CFR 52.970 - Identification of plan.

Code of Federal Regulations, 2012 CFR

2012-07-01

...)(50) Section 1303.A Toxic Substances 10/20/1995 7/05/2011, 76 FR 38977 Section 1305 Control of....999(c)(50) Section 1315 More Stringent Regulations may be Prescribed if Particulates are Toxic Jun... Law 30:2060 N.6 Toxic air pollution emission control program 10/22/92 06/23/94, 59 FR 32359 Ref 52.999...

40 CFR 52.970 - Identification of plan.

Code of Federal Regulations, 2013 CFR

2013-07-01

...)(50) Section 1303.A Toxic Substances 10/20/1995 7/05/2011, 76 FR 38977 Section 1305 Control of....999(c)(50) Section 1315 More Stringent Regulations may be Prescribed if Particulates are Toxic Jun... Law 30:2060 N.6 Toxic air pollution emission control program 10/22/92 06/23/94, 59 FR 32359 Ref 52.999...

After 'dieselgate': Regulations or economic incentives for a successful environmental policy?

NASA Astrophysics Data System (ADS)

Zachariadis, Theodoros

2016-08-01

In September 2015 the U.S. Environmental Protection Agency announced that it started investigations against the automaker Volkswagen for illegally installing software that allowed some diesel-powered vehicle models to pass stringent emission tests for type-approval. Although generally prohibited, modern software makes it feasible for vehicles to detect an emission test and modulate engine operation or emission control accordingly. It has also been well known to experts worldwide - and readers of this Journal - that emission tests for motor vehicles are conducted with outdated test procedures which do not reflect today's actual driving conditions and enable automakers to exploit 'flexibilities' so as to yield artificially low emission results. For example, on-road carbon dioxide (CO2) emissions of cars that entered the European market in 2014 were reportedly 40% higher than their formal test emissions, while this gap was less than 10% in the early 2000s (Tietge et al., 2015). In the case of health-related pollutant nitrogen oxides (NOx), this gap seems to be markedly higher, in particular for diesel-powered cars (Weiss et al., 2012) - whereas this does not seem to be a serious problem for other air pollutants. In internal combustion engines of motor vehicles there is still a trade-off between NOx emissions and fuel efficiency (and hence CO2 emissions): a fast combustion with high temperatures is optimal for maximum fuel efficiency and minimum CO2 emissions, whereas these conditions give rise to higher NOx emissions. Conversely, NOx control techniques such as exhaust gas recirculation reduce combustion temperature and often lead to lower fuel efficiency. In short, it becomes ever more difficult for internal combustion engines to meet the increasingly stringent legislated standards for some air pollutants and carbon dioxide at the same time. This increases the probability of applying legal and illegal defeat strategies.

Evaluating the effectiveness of air quality interventions.

PubMed

van Erp, Annemoon M M; O'Keefe, Robert; Cohen, Aaron J; Warren, Jane

2008-01-01

Evaluating the extent to which air quality regulations improve public health--sometimes referred to as accountability--is part of an emerging effort to assess the effectiveness of environmental regulatory policies. Air quality has improved substantially in the United States and Western Europe in recent decades, with far less visible pollution and decreasing concentrations of several major pollutants. In large part, these gains were achieved through increasingly stringent air quality regulations. The costs associated with compliance and, importantly, the need to ensure that the regulations are achieving the intended public health benefits underscore the importance of accountability research. To date, accountability research has emphasized measuring the effects of actions already taken to improve air quality. Such research may also contribute to estimating the burden of disease that might be avoided in the future if certain actions are taken. The Health Effects Institute (HEI) currently funds eight ongoing studies on accountability, which cover near-term interventions to improve air quality including (1) a ban on the sale of coal, (2) replacing old wood stoves with cleaner ones, (3) decreasing sulfur content in fuel, (4) measures to reduce traffic, and (5) longer term, wide-ranging actions or events (such as complex changes associated with the reunification of Germany). HEI is also funding the development of methods and research to assess regulations that are implemented incrementally over extended periods of time, such as Title IV of the 1990 Clean Air Act Amendments, which reduces sulfur dioxide emissions from power plants in the eastern United States.

The urgency of the development of CO2 capture from ambient air

PubMed Central

Lackner, Klaus S.; Brennan, Sarah; Matter, Jürg M.; Park, A.-H. Alissa; Wright, Allen; van der Zwaan, Bob

2012-01-01

CO2 capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society’s present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology—which by necessity has to operate on a large scale—it may need to be complemented with air capture, removing CO2 directly from the atmosphere. Air capture of CO2 could act as insurance against CO2 leaking from storage and furthermore may provide an option for dealing with emissions from mobile dispersed sources such as automobiles and airplanes. PMID:22843674

75 FR 2796 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-19

... noted that the limit for baked extreme performance coatings in the rule is less stringent than the limit... the VOC limit for baked extreme performance coatings and the exemption for repair and touch-up operations. As to the emission limit for baked extreme performance coatings, the VOC limit in Rule 4603 is...

Characteristics of typical non-road machinery emissions in China by using portable emission measurement system.

PubMed

Fu, Mingliang; Ge, Yunshan; Tan, Jianwei; Zeng, Tao; Liang, Bin

2012-10-15

Non-road machinery, especially construction equipment could be an important pollutant source of the deterioration in air quality in Chinese urban areas due to its large quantity and to the absence of stringent emission requirements. In this study, emission tests were performed on 12 excavators and 8 wheel loaders by using portable emission measurement system (PEMS) to determine their emission characteristics. The typical operating modes were categorized as idling mode, moving mode and working mode. Compared with those during idling and moving modes, the average time-based emission factors during working mode of HC were 2.61 and 1.27 times higher, NO(x) were 3.66 and 1.36 times higher, and PM were 4.05 and 1.95 times higher, respectively. Under all conditions, categories of the measured emissions increased with the rise in engine power. Compared with those of Stage I emission standard equipment, gaseous emissions and PM emitted from Stage II emission standard equipment were lower. The results indicated that, from Stage I to Stage II, the average reductions of HC, NO(x) and PM were 56%, 37% and 29% for the working mode, respectively. Those results also demonstrated the effectiveness of emission control regulation and the improvement of emission control technology. The data and tests show that the longer the accumulated working hours, the higher HC and NO(x) average fuel-based emission factors are. The emissions measured from the construction vehicles employed in this study were higher than the data collected in previous studies, which shows that it is critical for the government to put into effect more stringent emission regulations to further improve the air quality in Chinese urban areas. Copyright © 2012 Elsevier B.V. All rights reserved.

A multi-model assessment of the co-benefits of climate mitigation for global air quality

NASA Astrophysics Data System (ADS)

Rao, Shilpa; Klimont, Zbigniew; Leitao, Joana; Riahi, Keywan; van Dingenen, Rita; Aleluia Reis, Lara; Calvin, Katherine; Dentener, Frank; Drouet, Laurent; Fujimori, Shinichiro; Harmsen, Mathijs; Luderer, Gunnar; Heyes, Chris; Strefler, Jessica; Tavoni, Massimo; van Vuuren, Detlef P.

2016-12-01

We present a model comparison study that combines multiple integrated assessment models with a reduced-form global air quality model to assess the potential co-benefits of global climate mitigation policies in relation to the World Health Organization (WHO) goals on air quality and health. We include in our assessment, a range of alternative assumptions on the implementation of current and planned pollution control policies. The resulting air pollution emission ranges significantly extend those in the Representative Concentration Pathways. Climate mitigation policies complement current efforts on air pollution control through technology and fuel transformations in the energy system. A combination of stringent policies on air pollution control and climate change mitigation results in 40% of the global population exposed to PM levels below the WHO air quality guideline; with the largest improvements estimated for India, China, and Middle East. Our results stress the importance of integrated multisector policy approaches to achieve the Sustainable Development Goals.

Impacts of emission reduction and meteorological conditions on air quality improvement during the 2014 Youth Olympic Games in Nanjing, China

NASA Astrophysics Data System (ADS)

Huang, Qian; Wang, Tijian; Chen, Pulong; Huang, Xiaoxian; Zhu, Jialei; Zhuang, Bingliang

2017-11-01

As the holding city of the 2nd Youth Olympic Games (YOG), Nanjing is highly industrialized and urbanized, and faces several air pollution issues. In order to ensure better air quality during the event, the local government took great efforts to control the emissions from pollutant sources. However, air quality can still be affected by synoptic weather, not only emission. In this paper, the influences of meteorological factors and emission reductions were investigated using observational data and numerical simulations with WRF-CMAQ (Weather Research and Forecasting - Community Multiscale Air Quality). During the month in which the YOG were held (August 2014), the observed hourly mean concentrations of SO2, NO2, PM10, PM2.5, CO and O3 were 11.6 µg m-3, 34.0 µg m-3, 57.8 µg m-3, 39.4 µg m-3, 0.9 mg m-3 and 38.8 µg m-3, respectively, which were below China National Ambient Air Quality Standard (level 2). However, model simulation showed that the weather conditions, such as weaker winds during the YOG, were adverse for better air quality and could increase SO2, NO2, PM10, PM2.5 and CO by 17.5, 16.9, 18.5, 18.8, 7.8 and 0.8 %. Taking account of local emission abatement only, the simulated SO2, NO2, PM10, PM2.5 and CO decreased by 24.6, 12.1, 15.1, 8.1 and 7.2 %. Consequently, stringent emission control measures can reduce the concentrations of air pollutants in the short term, and emission reduction is very important for air quality improvement during the YOG. A good example has been set for air quality protection for important social events.

Phenol wastewater remediation: advanced oxidation processes coupled to a biological treatment.

PubMed

Rubalcaba, A; Suárez-Ojeda, M E; Stüber, F; Fortuny, A; Bengoa, C; Metcalfe, I; Font, J; Carrera, J; Fabregat, A

2007-01-01

Nowadays, there are increasingly stringent regulations requiring more and more treatment of industrial effluents to generate product waters which could be easily reused or disposed of to the environment without any harmful effects. Therefore, different advanced oxidation processes were investigated as suitable precursors for the biological treatment of industrial effluents containing phenol. Wet air oxidation and Fenton process were tested batch wise, while catalytic wet air oxidation and H2O2-promoted catalytic wet air oxidation processes were studied in a trickle bed reactor, the last two using over activated carbon as catalyst. Effluent characterisation was made by means of substrate conversion (using high liquid performance chromatography), chemical oxygen demand and total organic carbon. Biodegradation parameters (i.e. maximum oxygen uptake rate and oxygen consumption) were obtained from respirometric tests using activated sludge from an urban biological wastewater treatment plant (WWTP). The main goal was to find the proper conditions in terms of biodegradability enhancement, so that these phenolic effluents could be successfully treated in an urban biological WWTP. Results show promising research ways for the development of efficient coupled processes for the treatment of wastewater containing toxic or biologically non-degradable compounds.

Mixing enhancement strategies and their mechanisms in supersonic flows: A brief review

NASA Astrophysics Data System (ADS)

Huang, Wei

2018-04-01

Achieving efficient fuel-air mixing is a crucial issue in the design of the scramjet engine due to the compressibility effect on the mixing shear layer growth and the stringent flow residence time limitation induced by the high-speed crossflow, and the potential solution is to enhance mixing between air and fuel by introducing of streamwise vortices in the flow field. In this survey, some mixing enhancement strategies based on the traditional transverse injection technique proposed in recent years, as well as their mixing augmentation mechanisms, were reviewed in detail, namely the pulsed transverse injection scheme, the traditional transverse injection coupled with the vortex generator, and the dual transverse injection system with a front porthole and a rear air porthole arranged in tandem. The streamwise vortices, through the large-scale stirring motion that they introduce, are responsible for the extraction of large amounts of energy from the mean flow that can be converted into turbulence, ultimately leading to increased mixing effectiveness. The streamwise vortices may be obtained by taking advantage of the shear layer between a jet and the cross stream or by employing intrusive physical devices. Finally, a promising mixing enhancement strategy in supersonic flows was proposed, and some remarks were provided.

40 CFR 52.970 - Identification of plan.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Particulate Matter Jun 1988, LR14:348 06/15/89, 54 FR 25451 Ref 52.999(c)(50) Section 1303.A Toxic Substances... Stringent Regulations may be Prescribed if Particulates are Toxic Jun 1988, LR14:348 06/15/89, 54 FR 25451... Law 30:2060 N.6 Toxic air pollution emission control program 10/22/92 06/23/94, 59 FR 32359 Ref 52.999...

Potential contamination of shipboard air samples by diffusive emissions of PCBs and other organic pollutants: implications and solutions.

PubMed

Lohmann, Rainer; Jaward, Foday M; Durham, Louise; Barber, Jonathan L; Ockenden, Wendy; Jones, Kevin C; Bruhn, Regina; Lakaschus, Soenke; Dachs, Jordi; Booij, Kees

2004-07-15

Air samples were taken onboard the RRS Bransfield on an Atlantic cruise from the United Kingdom to Halley, Antarctica, from October to December 1998, with the aim of establishing PCB oceanic background air concentrations and assessing their latitudinal distribution. Great care was taken to minimize pre- and post-collection contamination of the samples, which was validated through stringent QA/QC procedures. However, there is evidence that onboard contamination of the air samples occurred,following insidious, diffusive emissions on the ship. Other data (for PCBs and other persistent organic pollutants (POPs)) and examples of shipboard contamination are presented. The implications of these findings for past and future studies of global POPs distribution are discussed. Recommendations are made to help critically appraise and minimize the problems of insidious/diffusive shipboard contamination.

Measurements of atmospheric ethene by solar absorption FTIR spectrometry

NASA Astrophysics Data System (ADS)

Toon, Geoffrey C.; Blavier, Jean-Francois L.; Sung, Keeyoon

2018-04-01

Atmospheric ethene (C2H4; ethylene) amounts have been retrieved from high-resolution solar absorption spectra measured by the Jet Propulsion Laboratory (JPL) MkIV interferometer. Data recorded from 1985 to 2016 from a dozen ground-based sites have been analyzed, mostly between 30 and 67° N. At clean-air sites such as Alaska, Sweden, New Mexico, or the mountains of California, the ethene columns were always less than 1 × 1015 molec cm-2 and therefore undetectable. In urban sites such as JPL, California, ethene was measurable with column amounts of 20 × 1015 molec cm-2 observed in the 1990s. Despite the increasing population and traffic in southern California, a factor 3 decrease in ethene column density is observed over JPL over the past 25 years, accompanied by a decrease in CO. This is likely due to southern California's increasingly stringent vehicle exhaust regulations and tighter enforcement over this period.

Application of IUS equipment and experience to orbit transfer vehicles of the 90's

NASA Astrophysics Data System (ADS)

Bangsund, E.; Keeney, J.; Cowgill, E.

1985-10-01

This paper relates experiences with the IUS program and the application of that experience to Future Orbit Transfer Vehicles. More specifically it includes the implementation of the U.S. Air Force Space Division high reliability parts standard (SMASO STD 73-2C) and the component/system test standard (MIL-STD-1540A). Test results from the parts and component level testing and the resulting system level test program for fourteen IUS flight vehicles are discussed. The IUS program has had the highest compliance with these standards and thus offers a benchmark of experience for future programs demanding extreme reliability. In summary, application of the stringent parts standard has resulted in fewer failures during testing and the stringent test standard has eliminated design problems in the hardware. Both have been expensive in costs and schedules, and should be applied with flexibility.

Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Frankenberg, Christian; Kulawik, Susan S.; Wofsy, Steven C.; Chevallier, Frédéric; Daube, Bruce; Kort, Eric A.; O'Dell, Christopher; Olsen, Edward T.; Osterman, Gregory

2016-06-01

In recent years, space-borne observations of atmospheric carbon dioxide (CO2) have been increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column-averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network (TCCON). Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) flights from 01/2009 through 09/2011 to validate CO2 measurements from satellites (Greenhouse Gases Observing Satellite - GOSAT, Thermal Emission Sounder - TES, Atmospheric Infrared Sounder - AIRS) and atmospheric inversion models (CarbonTracker CT2013B, Monitoring Atmospheric Composition and Climate (MACC) v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, in particular at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of -0.06 ppm, and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm, and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm, and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20, and 50 atmospheric soundings have been averaged for GOSAT, TES, and AIRS, respectively. Overall, we find that GOSAT soundings over the remote Pacific Ocean mostly meet the stringent accuracy requirements of about 0.5 ppm for space-based CO2 observations.

Advanced Space-Based Detector Research at the Air Force Research Laboratory

DTIC Science & Technology

2009-03-04

purposes. The dark backgrounds place very stringent requirements on the noise characteristics of the sensor system, resulting in FPAs that must be...signal within a single pixel of a detector. 2. Optical signal amplification 2.1. Quantum interference Quantum well infrared photodetectors ( QWIPs ) are...are now extremely attractive for a growing number of sensor applications. Although considerable progress has been made in QWIPs , their relatively low

Advanced Space-Based Detector Research at the Air Force Research Laboratory (PREPRINT)

DTIC Science & Technology

2006-10-01

purposes. The dark backgrounds place very stringent requirements on the noise characteristics of the sensor system, resulting in FPAs that must be cooled...2.1. Quantum interference Quantum well infrared photodetectors ( QWIPs ) are based on intersubband absorption in III–V semiconductor multi-quantum well...Although considerable progress has been made in QWIPs , their relatively low quantum efficiencies constitute their greatest problem for space-based

Estimating the Causal Effect of Low Levels of Fine Particulate Matter on Hospitalization.

PubMed

Makar, Maggie; Antonelli, Joseph; Di, Qian; Cutler, David; Schwartz, Joel; Dominici, Francesca

2017-09-01

In 2012, the EPA enacted more stringent National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5). Few studies have characterized the health effects of air pollution levels lower than the most recent NAAQS for long-term exposure to PM2.5 (now 12 μg/m). We constructed a cohort of 32,119 Medicare beneficiaries residing in 5138 US ZIP codes who were interviewed as part of the Medicare Current Beneficiary Survey (MCBS) between 2002 and 2010 and had 1 year of follow-up. We considered four outcomes: all-cause hospitalizations, hospitalizations for circulatory diseases and respiratory diseases, and death. We found that increasing exposure to PM2.5 from levels lower than 12 μg/m to levels higher than 12 μg/m is associated with increases in all-cause admission rates of 7% (95% CI = 3%, 10%) and in circulatory admission hazard rates of 6% (95% CI = 2%, 9%). When we restricted analysis to enrollees with exposure always lower than 12 μg/m, we found that increasing exposure from levels lower than 8 μg/m to levels higher than 8 μg/m increased all-cause admission hazard rates by 15% (95% CI = 8%, 23%), circulatory by 18% (95% CI = 10%, 27%), and respiratory by 21% (95% CI = 9%, 34%). In a nationally representative sample of Medicare enrollees, changes in exposure to PM2.5, even at levels consistently below standards, are associated with increases in hospital admissions for all causes and cardiovascular and respiratory diseases. The robustness of our results to inclusion of many additional individual level potential confounders adds validity to studies of air pollution that rely entirely on administrative data.

Environment of care: Is it time to reassess microbial contamination of the operating room air as a risk factor for surgical site infection in total joint arthroplasty?

PubMed

Parvizi, Javad; Barnes, Sue; Shohat, Noam; Edmiston, Charles E

2017-11-01

In the modern operating room (OR), traditional surgical mask, frequent air exchanges, and architectural barriers are viewed as effective in reducing airborne microbial populations. Intraoperative sampling of airborne particulates is rarely performed in the OR because of technical difficulties associated with sampling methodologies and a common belief that airborne contamination is infrequently associated with surgical site infections (SSIs). Recent studies suggest that viable airborne particulates are readily disseminated throughout the OR, placing patients at risk for postoperative SSI. In 2017, virtually all surgical disciplines are engaged in the implantation of selective biomedical devices, and these implants have been documented to be at high risk for intraoperative contamination. Approximately 1.2 million arthroplasties are performed annually in the United States, and that number is expected to increase to 3.8 million by the year 2030. The incidence of periprosthetic joint infection is perceived to be low (<2.5%); however, the personal and fiscal morbidity is significant. Although the pharmaceutic and computer industries enforce stringent air quality standards on their manufacturing processes, there is currently no U.S. standard for acceptable air quality within the OR environment. This review documents the contribution of air contamination to the etiology of periprosthetic joint infection, and evidence for selective innovative strategies to reduce the risk of intraoperative microbial aerosols. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

RT-MATRIX: Measuring Total Organic Carbon by Photocatalytic Oxidation of Volatile Organic Compounds

NASA Technical Reports Server (NTRS)

2008-01-01

Volatile organic compounds (VOCs) inevitably accumulate in enclosed habitats such as the International Space Station and the Crew Exploration Vehicle (CEV) as a result of human metabolism, material off-gassing, and leaking equipment. Some VOCs can negatively affect the quality of the crew's life, health, and performance; and consequently, the success of the mission. Air quality must be closely monitored to ensure a safe living and working environment. Currently, there is no reliable air quality monitoring system that meets NASA's stringent requirements for power, mass, volume, or performance. The ultimate objective of the project -- the development of a Real-Time, Miniaturized, Autonomous Total Risk Indicator System (RT.MATRIX).is to provide a portable, dual-function sensing system that simultaneously determines total organic carbon (TOC) and individual contaminants in air streams.

Separator electrode assembly (SEA) with 3-dimensional bioanode and removable air-cathode boosts microbial fuel cell performance

NASA Astrophysics Data System (ADS)

Oliot, M.; Etcheverry, L.; Mosdale, A.; Basseguy, R.; Délia, M.-L.; Bergel, A.

2017-07-01

Separator electrode assemblies (SEAs) were designed by associating a microbial anode with an air-cathode on each side of three different kinds of separator: plastic grid, J-cloth and baking paper. The SEA was designed to allow the air-cathode be removed and replaced without disturbing the bioanode. Power densities up to 6.4 W m-2 were produced by the Grid-SEAs (on average 5.9 ± 0.5 W m-2) while JCloth-SEAs and Paper-SEAs produced 4.8 ± 0.3 and 1.8 ± 0.1 W m-2, respectively. Power densities decreased with time mainly because of fast deterioration of the cathode kinetics. They always increased again when the air-cathodes were replaced by new ones; the Grid-SEAs were thus boosted above 4 W m-2 after 7 weeks of operation. The theoretical analysis of SEA functioning suggested that the high performance of the Grid-SEAs was due to the combination of several virtuous phenomena: the efficient pH balance thanks to free diffusion through the large-mesh grid, the likely mitigation of oxygen crossover thanks to the 3-dimensional structure of the bioanode and the possibility of overcoming cathode fouling by replacing it during MFC operation. Finally, the microbial community of all bioanodes showed stringent selection of Proteiniphilum acetatigenes in proportion with the performance.

Nanoscale Capillary Flows in Alumina: Testing the Limits of Classical Theory.

PubMed

Lei, Wenwen; McKenzie, David R

2016-07-21

Anodic aluminum oxide (AAO) membranes have well-formed cylindrical channels, as small as 10 nm in diameter, in a close packed hexagonal array. The channels in AAO membranes simulate very small leaks that may be present for example in an aluminum oxide device encapsulation. The 10 nm alumina channel is the smallest that has been studied to date for its moisture flow properties and provides a stringent test of classical capillary theory. We measure the rate at which moisture penetrates channels with diameters in the range of 10 to 120 nm with moist air present at 1 atm on one side and dry air at the same total pressure on the other. We extend classical theory for water leak rates at high humidities by allowing for variable meniscus curvature at the entrance and show that the extended theory explains why the flow increases greatly when capillary filling occurs and enables the contact angle to be determined. At low humidities our measurements for air-filled channels agree well with theory for the interdiffusive flow of water vapor in air. The flow rate of water-filled channels is one order of magnitude less than expected from classical capillary filling theory and is coincidentally equal to the helium flow rate, validating the use of helium leak testing for evaluating moisture flows in aluminum oxide leaks.

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

NASA Astrophysics Data System (ADS)

Ball, James M.; Bouwer, Ricardo K. M.; Kooistra, Floris B.; Frost, Jarvist M.; Qi, Yabing; Domingo, Ester Buchaca; Smith, Jeremy; de Leeuw, Dago M.; Hummelen, Jan C.; Nelson, Jenny; Kahn, Antoine; Stingelin, Natalie; Bradley, Donal D. C.; Anthopoulos, Thomas D.

2011-07-01

The family of soluble fullerene derivatives comprises a widely studied group of electron transporting molecules for use in organic electronic and optoelectronic devices. For electronic applications, electron transporting (n-channel) materials are required for implementation into organic complementary logic circuit architectures. To date, few soluble candidate materials have been studied that fulfill the stringent requirements of high carrier mobility and air stability. Here we present a study of three soluble fullerenes with varying electron affinity to assess the impact of electronic structure on device performance and air stability. Through theoretical and experimental analysis of the electronic structure, characterization of thin-film structure, and characterization of transistor device properties we find that the air stability of the present series of fullerenes not only depends on the absolute electron affinity of the semiconductor but also on the disorder within the thin-film.

NOx Emission Reduction by Oscillating combustion

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

Institute of Gas Technology

2004-01-30

High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiencymore » for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the attributes of oscillating combustion and on the results of an earlier project at GTI and Air Liquide, to determine which applications for oscillating combustion would show the greatest probability for technical success and greatest probability for market acceptability. The market study indicated that furnaces in the steel, glass, and metal melting industries would perform well in both categories. These findings guided the selection of burners for laboratory testing and, with the results of the laboratory testing, guided the selection of field test sites.« less

NOx Emission Reduction by Oscillating Combustion

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

John C. Wagner

2004-03-31

High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiencymore » for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the attributes of oscillating combustion and on the results of an earlier project at GTI and Air Liquide, to determine which applications for oscillating combustion would show the greatest probability for technical success and greatest probability for market acceptability. The market study indicated that furnaces in the steel, glass, and metal melting industries would perform well in both categories. These findings guided the selection of burners for laboratory testing and, with the results of the laboratory testing, guided the selection of field test sites.« less

Voluntary Compliance, Pollution Levels, and Infant Mortality in Mexico.

PubMed

Foster, Andrew; Gutierrez, Emilio; Kumar, Naresh

2009-05-01

The increasing body of evidence from high income countries linking pollution to health outcomes (Ken Chay and Michael Greenstone 2003; Janet Currie and Matthew Neidell 2004), has raised concerns about the health impact of adverse air quality in developing countries, where, in general, environmental regulation is less stringent and health monitoring and treatment are less accessible. These concerns have, in turn, encouraged consideration of the effectiveness of alternative mechanisms for improving air quality while limiting the adverse impact on economic growth. However, the analysis of both the effects of pollution on health and the effectiveness of pollution abatement policies faces particular empirical challenges in low- and middle-income contexts, given the scarcity of reliable measures of pollution concentrations. The primary source of good quality data on air quality, ground monitoring, tends to be limited to larger metropolitan areas with monitors placed at sentinel sites that may or may not yield a representative picture of population exposure. This paper calls attention to, and makes use of, newly available procedures for extracting measures of air quality from satellite imagery. In particular, satellite-based measures of aerosol optical depth (AOD) are used to obtain estimates of air quality for the whole Mexican territory at a detailed geographic scale, and these estimates are related to measures of participation in a voluntary certification program at the level of the county. The resulting estimates are then combined with estimates of the relationship between participation in the certification program and infant mortality due to respiratory causes to obtain a rough estimate of the relationship between air quality and infant health in Mexico.

Technology innovations and experience curves for nitrogen oxides control technologies.

PubMed

Yeh, Sonia; Rubin, Edward S; Taylor, Margaret R; Hounshell, David A

2005-12-01

This paper reviews the regulatory history for nitrogen oxides (NOx) pollutant emissions from stationary sources, primarily in coal-fired power plants. Nitrogen dioxide (NO2) is one of the six criteria pollutants regulated by the 1970 Clean Air Act where National Ambient Air Quality Standards were established to protect public health and welfare. We use patent data to show that in the cases of Japan, Germany, and the United States, innovations in NOx control technologies did not occur until stringent government regulations were in place, thus "forcing" innovation. We also demonstrate that reductions in the capital and operation and maintenance (O&M) costs of new generations of high-efficiency NOx control technologies, selective catalytic reduction (SCR), are consistently associated with the increasing adoption of the control technology: the so-called learning-by-doing phenomena. The results show that as cumulative world coal-fired SCR capacity doubles, capital costs decline to approximately 86% and O&M costs to 58% of their original values. The observed changes in SCR technology reflect the impact of technological advance as well as other factors, such as market competition and economies of scale.

Atmosphere Resource Recovery and Environmental Monitoring

NASA Technical Reports Server (NTRS)

Roman, Monsi; Howard, David

2015-01-01

Atmosphere Resource Recovery and Environmental Monitoring (ARREM) is a project focused on evolving existing and maturing emerging 'closed loop' atmosphere revitalization (AR) life support systems that produce clean, breathable air for crewmembers, and developing a suite of low mass, low power environmental monitors to detect and measure air- and waterborne constituents and contaminants. The objective is to improve reliability and efficiency, reduce mass and volume, and increase recovery of oxygen from carbon dioxide created by human metabolism from 43% to greater than 90%. The technology developments under ARREM are vital to extending human space missions from low-Earth orbit like the International Space Station to destinations deeper into space such as Mars where dependency on Earth for resupply of maintenance items and critical life support elements such as water and oxygen is not possible. The primary goal of the ARREM project is to demonstrate that systems meet the more stringent performance parameters for deep space exploration and are compatible with other systems within closed loop life support through a series of integrated tests performed in an environmental test chamber capable of simulating human metabolic activities and measuring systems outputs.

Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

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

Phadke, Amol; Shah, Nihar; Abhyankar, Nikit

Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant,and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. The finding that significant efficiency improvement is cost effective from a consumer perspective is robustmore » over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one-star level) should be evaluated rigorously considering significant benefits to consumers, energy security, and environment« less

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

Maxwell, S.; Berger, D.; Zuluaga, M.

In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent. CARB researchers have found that most new high performance, multifamily housing in the Northeast use one of four strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unitmore » HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. Product performance data are based on laboratory tests, but there is no guarantee that those conditions will exist consistently in the finished building. In this research project, CARB evaluated the four ventilation strategies in the field to validate system performance.« less

Avoiding Clean Air Act Enforcement Actions

DTIC Science & Technology

1994-06-01

process or common-source permits (for instance, all boilers or all sources within a defined area on one per- mit); or separate permits for every source of... boilers ; and explosive produc- tion processes. The limitations on NO. emissions may become more stringent if it is determined that these emissions...ISC = Infornmtbon Systems C~r;, INSCOM w; HSC m HhO Sewims Com- rand; FORSCOM - Forces Command; ARNG a Army Natonal Guwd; AMC = Army Maet Command

Modeling effects of moisture content and advection on odor causing VOCs volatilization from stored swine manure.

PubMed

Liao, C M; Liang, H M

2000-05-01

Two models for evaluating the contents and advection of manure moisture on odor causing volatile organic compounds (VOC-odor) volatilization from stored swine manure were studied for their ability to predict the volatilization rate (indoor air concentration) and cumulative exposure dose: a MJ-I model and a MJ-II model. Both models simulating depletion of source contaminant via volatilization and degradation based on an analytical model adapted from the behavior assessment model of Jury et al. In the MJ-I model, manure moisture movement was negligible, whereas in the MJ-II model, time-dependent indoor air concentrations was a function of constant manure moisture contents and steady-state moisture advection. Predicted indoor air concentrations and inhaled doses for the study VOC-odors of p-cresol, toluene, and p-xylene varied by up to two to three orders of magnitude depending on the manure moisture conditions. The sensitivity analysis of both models suggests that when manure moisture movement exists, simply MJ-I model is inherently not sufficient to represent a more generally volatilization process, which can even become stringent as moisture content increases. The conclusion illustrates how one needs to include a wide variety of manure moisture values in order to fully assess the complex volatilization mechanisms that are present in a real situation.

Emission Projections for Long-Haul Freight Trucks and Rail in the United States through 2050.

PubMed

Liu, Liang; Hwang, Taesung; Lee, Sungwon; Ouyang, Yanfeng; Lee, Bumsoo; Smith, Steven J; Yan, Fang; Daenzer, Kathryn; Bond, Tami C

2015-10-06

This work develops an integrated model approach for estimating emissions from long-haul freight truck and rail transport in the United States between 2010 and 2050. We connect models of macroeconomic activity, freight demand by commodity, transportation networks, and emission technology to represent different pathways of future freight emissions. Emissions of particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and total hydrocarbon (THC) decrease by 60%-70% from 2010 to 2030, as older vehicles built to less-stringent emission standards retire. Climate policy, in the form of carbon tax that increases apparent fuel prices, causes a shift from truck to rail, resulting in a 30% reduction in fuel consumption and a 10%-28% reduction in pollutant emissions by 2050, if rail capacity is sufficient. Eliminating high-emitting conditions in the truck fleet affects air pollutants by 20% to 65%; although these estimates are highly uncertain, they indicate the importance of durability in vehicle engines and emission control systems. Future infrastructure investment will be required both to meet transport demand and to enable actions that reduce emissions of air and climate pollutants. By driving the integrated model framework with two macroeconomic scenarios, we show that the effect of carbon tax on air pollution is robust regardless of growth levels.

The European project CASAM for the protection of commercial airliners in flight

NASA Astrophysics Data System (ADS)

Vergnolle, Jean-François

2007-10-01

As part of mass transportation systems, commercial aircraft are a potential target for terrorists because they represent one of the best achievements of our society. As a result, an attack would have a large psychological impact on people and economic activity. Several European Commission-funded Research and Technology programs, such as SAFEE and PALMA, are dedicated to technologies and systems that will be implemented onboard aircraft in the near future to increase the security of commercial flights. One of these programs, CASAM, is focusing on a potential solution to reduce aircraft vulnerability against Man Portable Air Defense Systems (MANPADS) during takeoff, ascent and landing. A specific onboard jamming system will be developed, meeting stringent yet competitive requirements that deal with high reliability, low cost and minimal installation constraints. The overall objective of the CASAM Project1 is to design and validate a closed-loop, laser-based DIRCM (Directed IR Countermeasure) module for jamming fired missiles. It will comply with commercial air transportation constraints, including the normal air traffic control rules. For example, the following aspects will be considered: - Environmental friendliness for ground objects and inhabitants close to airports, aircraft safety (maintenance, handling and usage) and high efficiency against the recognized threats; - Upgradability for further and future disseminated threats - Adherence to commercial operation budgets and processes

Hospital preparedness in community measles outbreaks—challenges and recommendations for low-resource settings

PubMed Central

Shakoor, Sadia; Mir, Fatima; Zaidi, Anita K. M.; Zafar, Afia

2015-01-01

We have reviewed various strategies involved in containment of measles in healthcare facilities during community outbreaks. The strategies that are more applicable to resource-poor settings, such as natural ventilation, mechanical ventilation with heating and air-conditioning systems allowing unidirectional air-flow, and protection of un-infected patients and healthcare workers (HCWs), have been examined. Ventilation methods need innovative customization for resource-poor settings followed by validation and post-implementation analysis for impact. Mandatory vaccination of all HCWs with two doses of measles-containing vaccine, appropriate post-exposure prophylaxis of immunocompromised inpatients, and stringent admission criteria for measles cases can contribute toward reduction of nosocomial and secondary transmission within facilities. PMID:25882388

Technology Solutions Case Study: Evaluation of Ventilation Strategies in New Construction Multifamily Buildings, New York, New York

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

None

2014-09-01

In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the "normal leakage paths through the building envelope" disappear. Consortium for Advanced Residential Buildings researchers have found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust withmore » ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. This research effort included several weeks of building pressure monitoring to validate system performance of the different strategies for providing make-up air to apartments.« less

Design and Optimisation of Electrostatic Precipitator for Diesel Exhaust

NASA Astrophysics Data System (ADS)

Srinivaas, A.; Sathian, Samanyu; Ramesh, Arjun

2018-02-01

The principle of an industrially used emission reduction technique is employed in automotive diesel exhaust to reduce the diesel particulate emission. As the Emission regulation are becoming more stringent legislations have been formulated, due to the hazardous increase in the air quality index in major cities. Initially electrostatic precipitation principle and working was investigated. The High voltage requirement in an Electrostatic precipitator is obtained by designing an appropriate circuit in MATLAB -SIMULINK. Mechanical structural design of the new model after treatment device for the specific diesel exhaust was done. Fluid flow analysis of the ESP model was carried out using ANSYS CFX for optimized fluid with a reduced back pressure. Design reconsideration was done in accordance with fluid flow analysis. Accordingly, a new design is developed by considering diesel particulate filter and catalytic converter design to ESP model.

Feedback System Theory

DTIC Science & Technology

1978-11-01

R 2. GOVT A $ SION NO. 3 RIEqLPýIVT’S.;TALOG NUMBER r/ 4. TITLE (and wbiFflT, -L M4 1 , FEEDBACK SYSTEM THEORY ~r Inter in- 6. PERFORMING ORG. REPORT...ANNUAL REPORT FEEDBACK SYSTEM THEORY AFOSR GRANT NO. 76-2946B Air Force Office of Scientific Research for year ending October 31, 1978 79 02 08 L|I...re less stringent than in other synthesis techniques which cannot handle significant parameter uncertainty. _I FEEDBACK SYSTEM THEORY 1. Introduction

Healthy Zero Energy Buildings (HZEB) Program - Cross-Sectional Study of Contaminant Levels, Source, Strengths, and Ventilation Rates in Retail Stores

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

Chan, Wanyu R.; Sidheswaran, Meera; Cohn, Sebastian

2014-02-01

This field study measured ventilation rates and indoor air quality parameters in 21 visits to retail stores in California. The data was collected to guide the development of new, science-based commercial building ventilation rate standards that balance the dual objectives of increasing energy efficiency and maintaining acceptable indoor air quality. Data collection occurred between September 2011 and March 2013. Three types of stores participated in this study: grocery stores, furniture/hardware stores, and apparel stores. Ventilation rates and indoor air contaminant concentrations were measured on a weekday, typically between 9 am and 6 pm. Ventilation rates measured using a tracer gasmore » decay method exceeded the minimum requirement of California’s Title 24 Standard in all but one store. Even though there was adequate ventilation according to Title 24, concentrations of formaldehyde, acetaldehyde, and acrolein exceeded the most stringent chronic health guidelines. Other indoor air contaminants measured included carbon dioxide (CO{sub 2}), carbon monoxide (CO), ozone (O{sub 3}), and particulate matter (PM). Concentrations of CO{sub 2} were kept low by adequate ventilation, and were assumed low also because the sampling occurred on a weekday when retail stores were less busy. CO concentrations were also low. The indoor-outdoor ratios of O{sub 3} showed that the first-order loss rate may vary by store trade types and also by ventilation mode (mechanical versus natural). Analysis of fine and ultrafine PM measurements showed that a substantial portion of the particle mass in grocery stores with cooking-related emissions was in particles less than 0.3 μm. Stores without cooking as an indoor source had PM size distributions that were more similar indoors and outdoors. The whole-building emission rates of volatile organic compounds (VOCs) and PM were estimated from the measured ventilation rates and indoor and outdoor contaminant concentrations. Mass balance models were then used to determine the ventilation rates, filtration strategies, or source reductions needed to maintain indoor contaminant concentrations below reference levels. Several scenarios of potential concern were considered: (i) formaldehyde levels in furniture/hardware stores, (ii) contaminants associated with cooking (e.g., PM, acrolein, and acetaldehyde) in grocery stores, and (iii) outdoor contaminants (e.g., PM and O{sub 3}) impacting stores that use natural ventilation. Estimated formaldehyde emission rates suggest that retail stores would need to ventilate at levels far exceeding the current Title 24 requirement to lower indoor concentrations below California’s stringent formaldehyde reference level. Given the high costs of providing ventilation but only modest chronic health benefit is expected, effective source control is an attractive alternative, as demonstrated by some retail stores in this study. Predictions showed that grocery stores need MERV 13 air filters, instead of MERV 8 filters that are more commonly used, to maintain indoor PM at levels that meet the chronic health standards for PM. Exposure to acrolein is a potential health concern in grocery stores, and should be addressed by increasing the use of kitchen range hoods or improving their contaminant removal efficiency. In stores that rely on natural ventilation, indoor PM can be a health concern if the stores are located in areas with high outdoor PM. This concern may be addressed by switching to mechanical ventilation when the outdoor air quality is poor, while continuing natural ventilation when outdoor air quality is good.« less

The burden of ischemic heart disease related to ambient air pollution exposure in a coastal city in South China.

PubMed

Huang, Jing; Li, Guoxing; Qian, Xujun; Xu, Guozhang; Zhao, Yan; Huang, Jian; Liu, Qichen; He, Tianfeng; Guo, Xinbiao

2018-07-01

Air pollution is considered one of the most important risk factors for ischemic heart disease (IHD), which is a major public health concern. The disease burden of IHD has continued to rise in China in the past two decades. However, epidemiological studies examining the associations between air pollution and IHD have been scarce in China, and the only studies were conducted in severe air pollution areas, where air pollution levels seriously exceed the World Health Organization Air Quality Guidelines. Whether the influence of air pollution on IHD in areas with relatively low levels of air pollution differs from the influence of high pollution levels in heavily studied areas was unknown until now. Furthermore, the estimation of the disease burden of IHD related to air pollution has been very limited. We conducted a time-series study to estimate the short-term burden of ambient air pollution on IHD using the indicator of years of life lost (YLL), based on 10 322 IHD deaths from 2011 to 2015 in Ningbo, a coastal city in South China. The mean concentrations of fine particle (PM 2.5 ), sulfur dioxide (SO 2 ) and nitrogen dioxide (NO 2 ) were 49.58 μg/m 3 , 21.34 μg/m 3 and 43.41 μg/m 3 , respectively. A 10 μg/m 3 increase in PM 2.5 , SO 2 and NO 2 was associated with changes in YLL of 0.71 (95%CI: - 0.21,1.64), 3.31 (95%CI: 0.78, 5.84), and 2.27 (95%CI: 0.26, 4.28) years, respectively. Relatively stronger impacts were found for gaseous pollutants than PM 2.5 . A larger increase in YLL was found in the younger population than in the older population for NO 2 exposure. In addition, estimations of the effects of SO 2 and NO 2 on YLL were higher for males than females. SO 2 exposure was positively associated with YLL in widowed group. The findings highlighted the importance of stringent air pollution control, especially for gaseous pollutants. Furthermore, using the indicator of YLL, considering the occurrence of death at different ages, provided more information for resource allocation and protection of vulnerable populations. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of Changing Emissions on Ozone and Particulates in the Northeastern United States

NASA Astrophysics Data System (ADS)

Frost, G. J.; McKeen, S.; Trainer, M.; Ryerson, T.; Holloway, J.; Brock, C.; Middlebrook, A.; Wollny, A.; Matthew, B.; Williams, E.; Lerner, B.; Fortin, T.; Sueper, D.; Parrish, D.; Fehsenfeld, F.; Peckham, S.; Grell, G.; Peltier, R.; Weber, R.; Quinn, P.; Bates, T.

2004-12-01

Emissions of nitrogen oxides (NOx) from electric power generation have decreased in recent years due to changes in burner technology and fuels used. Mobile NOx emissions assessments are less certain, since they must account for increases in vehicle miles traveled, changes in the proportion of diesel and gasoline vehicles, and more stringent controls on engines and fuels. The impact of these complicated emission changes on a particular region's air quality must be diagnosed by a combination of observation and model simulation. The New England Air Quality Study - Intercontinental Transport and Chemical Transformation 2004 (NEAQS-ITCT 2004) program provides an opportunity to test the effects of changes in emissions of NOx and other precursors on air quality in the northeastern United States. An array of ground, marine, and airborne observation platforms deployed during the study offer checks on emission inventories and air quality model simulations, like those of the Weather Research and Forecasting model coupled with online chemistry (WRF-Chem). Retrospective WRF-Chem runs are carried out with two EPA inventories, one compiled for base year 1999 and an update for 2004 incorporating projected and known changes in emissions during the past 5 years. Differences in model predictions of ozone, particulates, and other tracers using the two inventories are investigated. The inventories themselves and the model simulations are compared with the extensive observations available during NEAQS-ITCT 2004. Preliminary insights regarding the sensitivity of the model to NOx emission changes are discussed.

Changes in O3 and NO2 due to emissions from Fracking in the UK.

NASA Astrophysics Data System (ADS)

Archibald, Alexander; Ordonez, Carlos

2016-04-01

Poor air quality is a problem that affects millions of people around the world. Understanding the driving forces behind air pollution is complicated as the precursor gases which combine to produce air pollutants react in a highly non-linear manner and are subject to a range of atmospheric transport mechanisms compounded by the weather. A great deal of money has been spent on mitigating air pollution and so it's important to assess the impacts that new technologies that emit air pollutant precursors may have on local and regional air pollution. One of the most highly discussed new technologies that could impact air quality is the adoption of wide-scale hydraulic fracturing or "fracking" for natural gas. Indeed in regions of the USA where fracking is commonplace large levels of ozone (O3 - a key air pollutant) have been observed and attributed directly to the fracking process. In this study, a numerical modelling framework was used to assess possible impacts of fracking in the UK where at present no large scale fracking facilities are in operation. A number of emissions scenarios were developed for the principle gas phase air pollution precursors: the oxides of nitrogen (NOx) and volatile organic compounds (VOCs). These emissions scenarios were then used in a state-of-the-art numerical air quality model (the UK Met Office operational air quality forecasting model AQUM) to determine potential impacts related to fracking on UK air quality. Comparison of base model results and observations for the year 2013 of NOx, O3 and VOCs from the UK Automatic Urban and Rural Network (AURN) showed that AQUM has good skill at simulating these gas phase air pollutants (O3 r=0.64, NMGE=0.3; NO2 r=0.62, NMGE=0.51). Analysis of the simulations with fracking emissions demonstrate that there are large changes in 1hr max NO2 (11.6±6.6 ppb) with modest increases in monthly mean NO2, throughout the British Isles (150±100 ppt). These results highlight that stringent measures should be applied to prevent deleterious impacts on air quality from emissions related to fracking in the UK.

Impact of CNG implementation on PAHs concentration in the ambient air of Delhi: a comparative assessment of pre- and post-CNG scenario.

PubMed

Khillare, P S; Agarwal, Tripti; Shridhar, Vijay

2008-12-01

The use of alternative fuel is considered to be an effective measure to improve the urban air quality. Concerned over deteriorating air quality in Delhi, the Delhi government initiated different measures including stringent emission norms, improved fuel quality and above all introduction of cleaner fuel-CNG in public transport system. The entire city bus fleet was converted to CNG mode by 2002. The present study reports the comparative assessment of the status of air quality with respect to PM(10) and PAH before and after the introduction of CNG in public transport system in Delhi. The study has been carried out for two different time periods: first in the year 1998 and second in the year 2004. Following the total conversion of public transport system to CNG in 2002, Post-CNG data indicate a sharp reduction of 51-74% in the PM(10) concentration and 58-68% in the TPAH concentration as compared to the Pre-CNG data.

Mexico City, Mexico as seen from STS-62

NASA Image and Video Library

1994-03-05

STS062-84-028 (4-18 March 1994) --- According to NASA scientists this image is the clearest photo of Mexico City taken from United States manned spacecraft. North is to the upper right. Mexico City sits in a basin surrounded by large volcanoes. The restricted atmospheric circulation in the basin, coupled with the inevitable air emissions produced by a city of 20 million people has created a critical air pollution problem for the city. In most photographs of the region, Mexico City is obscured by haze. Scientists feel the clear atmosphere in this photograph may be due, in part, to the stringent air emission restrictions now in place. The clarity of the photograph allows many key cultural features to be identified, including all of the major boulevards, the horse track (western part of the city), the university (south of the city), and the museum areas. Large, man-made ponds east of the city also stand out.

Australians are not equally protected from industrial air pollution

NASA Astrophysics Data System (ADS)

Dobbie, B.; Green, D.

2015-05-01

Australian air pollution standards are set at national and state levels for a number of chemicals harmful to human health. However, these standards do not need to be met when ad hoc pollution licences are issued by state environment agencies. This situation results in a highly unequal distribution of air pollution between towns and cities, and across the country. This paper examines these pollution regulations through two case studies, specifically considering the ability of the regulatory regime to protect human health from lead and sulphur dioxide pollution in the communities located around smelters. It also considers how the proposed National Clean Air Agreement, once enacted, might serve to reduce this pollution equity problem. Through the case studies we show that there are at least three discrete concerns relating to the current licencing system. They are: non-onerous emission thresholds for polluting industry; temporal averaging thresholds masking emission spikes; and ineffective penalties for breaching licence agreements. In conclusion, we propose a set of new, legally-binding national minimum standards for industrial air pollutants must be developed and enforced, which can only be modified by more (not less) stringent state licence arrangements.

An Assessment of Ground Level and Free Tropospheric Ozone Over California and Nevada

NASA Astrophysics Data System (ADS)

Yates, E. L.; Johnson, M. S.; Iraci, L. T.; Ryoo, J.-M.; Pierce, R. B.; Cullis, P. D.; Gore, W.; Ives, M. A.; Johnson, B. J.; Leblanc, T.; Marrero, J. E.; Sterling, C. W.; Tanaka, T.

2017-09-01

Increasing free tropospheric ozone (O3), combined with the high elevation and often deep boundary layers at western U.S. surface stations, poses challenges in attaining the more stringent 70 ppb O3 National Ambient Air Quality Standard. As such, use of observational data to identify sources and mechanisms that contribute to surface O3 is increasingly important. This work analyzes surface and vertical O3 observations over California and Nevada from 1995 to 2015. Over this period, the number of high O3 events (95th percentile) at the U.S. Environmental Protection Agency Clean Air Status and Trends Network (CASTNET) sites has decreased during summer, as a result of decreasing U.S. emissions. In contrast, an increase in springtime 5th percentile O3 indicates a general increase of baseline O3. During 2012 there was a peak in exceedances and in the average spring-summer O3 mixing ratios at CASTNET sites. Goddard Earth Observing System-Chem results show that the surface O3 attributable to transport from the upper troposphere and stratosphere was increased in 2013 compared to 2012, highlighting the importance of measurements aloft. Vertical O3 measurements from aircraft, ozonesondes, and lidar show distinct seasonal trends, with a high percentage of elevated O3 laminae (O3 > 70 ppb, 3-8 km) during spring and summer. Analysis of the timing of high O3 surface events and correlation between surface and vertical O3 data is used to discuss varying sources of western U.S. surface O3.

Western US Tropospheric Ozone: An Assessment of Vertical and Seasonal Variations over California and Nevada

NASA Technical Reports Server (NTRS)

Yates, E.; Iraci, Laura T.; Johnson, Matthew; Ryoo, Ju-Mee; Pierce, Bradley R.; Cullis, Patrick; Gore, Warren J. Y.; Ives, Michael; Johnson, Bryan; LeBlanc, Thierry;

Genotypic variability enhances the reproducibility of an ecological study.

PubMed

Milcu, Alexandru; Puga-Freitas, Ruben; Ellison, Aaron M; Blouin, Manuel; Scheu, Stefan; Freschet, Grégoire T; Rose, Laura; Barot, Sebastien; Cesarz, Simone; Eisenhauer, Nico; Girin, Thomas; Assandri, Davide; Bonkowski, Michael; Buchmann, Nina; Butenschoen, Olaf; Devidal, Sebastien; Gleixner, Gerd; Gessler, Arthur; Gigon, Agnès; Greiner, Anna; Grignani, Carlo; Hansart, Amandine; Kayler, Zachary; Lange, Markus; Lata, Jean-Christophe; Le Galliard, Jean-François; Lukac, Martin; Mannerheim, Neringa; Müller, Marina E H; Pando, Anne; Rotter, Paula; Scherer-Lorenzen, Michael; Seyhun, Rahme; Urban-Mead, Katherine; Weigelt, Alexandra; Zavattaro, Laura; Roy, Jacques

2018-02-01

Many scientific disciplines are currently experiencing a 'reproducibility crisis' because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduce reproducibility by amplifying the impacts of laboratory-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that a deliberate introduction of controlled systematic variability (CSV) in experimental designs may lead to increased reproducibility. To test this hypothesis, we had 14 European laboratories run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures. Each laboratory introduced environmental and genotypic CSV within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV led to 18% lower among-laboratory variability in growth chambers, indicating increased reproducibility, but had no significant effect in glasshouses where reproducibility was generally lower. Environmental CSV had little effect on reproducibility. Although there are multiple causes for the 'reproducibility crisis', deliberately including genetic variability may be a simple solution for increasing the reproducibility of ecological studies performed under stringently controlled environmental conditions.

IRST: a key system in modern warfare

NASA Astrophysics Data System (ADS)

Missirian, Jean-Michel; Ducruet, Laurent

1997-08-01

A naval infra red search and track (IRST) system is a passive surveillance device capable of detecting and tracking air and surface threats in the region where electromagnetic sensors are less efficient, typically within a few degrees around the horizon. The evolution in anti ship sea skimming missiles performances has outlined the benefit that can be gained from infrared systems in ship self-defense. The complementary nature of radar and IRST systems can also be exploited to full advantage in the field of multisensor data fusion. The combined use of radar and infrared secures the detection by redundancy of data; it substantially enhances target tracking, classification and identification and reduces the combat system's reaction time. Designing an IRST implies matching technical choices with operational requirements, and this under increasingly stringent cost constraints. This paper first reminds the benefits that can be obtained with an IRST system in the context of modern naval warfare, then retraces the evolutions from the first generation IRST systems, such as VAMPIR, to the second-generation systems now entering service. A general presentation of the current SAGEM SA IRST family is also made for naval, air and ground-based applications.

Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

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

Shah, Nihar; Abhyankar, Nikit; Park, Won Young

Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. We assess several efficiency levels, two of which are summarized below in the report.more » The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one star level) should be evaluated rigorously considering significant benefits to consumers, energy security and environment.« less

Urban air chemistry and diesel vehicles emissions: Quantifying small and big hydrocarbons by CIMS to improve emission inventories

NASA Astrophysics Data System (ADS)

Jobson, B. T.; Derstroff, B.; Edtbauer, A.; VanderSchelden, G. S.; Williams, J.

2017-10-01

Emissions from vehicles are a major source of volatile organic compounds (VOCs) in urban environments. Photochemical oxidation of VOCs emitted from vehicle exhaust contributes to O3 and PM2.5 formation, harmful pollutants that major urban areas struggle to control. How will a shift to a diesel engine fleet impact urban air chemistry? Diesel vehicles are a growing fraction of the passenger vehicle fleet in Europe as a result of a deliberate policy to reduce energy consumption and CO2 emissions from the transportation sector (Sullivan et al., 2004). In countries such as France the diesel passenger fleet was already ∼50% of the total in 2009, up from 20% in 1995. Dunmore et al. (2015) have recently inferred that in London, HO radical loss rates to organic compounds is dominated by diesel engine emissions. In the US, increasingly more stringent vehicles emission standards and requirement for improved energy efficiency means spark ignition passenger vehicle emissions have declined significantly over the last 20 years, resulting in the urban diesel fleet traffic (freight trucks) having a growing importance as a source of vehicle pollution (McDonald et al., 2013). The recent scandal involving a major car manufacturer rigging emission controls for diesel passenger cars is a reminder that real world emissions of VOCs from diesel engines are not well understood nor thoroughly accounted for in air quality modeling.

Constructing a sustainable power sector in China: current and future emissions of coal-fired power plants from 2010 to 2030

NASA Astrophysics Data System (ADS)

Tong, D.; Zhang, Q.

2017-12-01

As the largest energy infrastructure in China, power sector consumed more coal than any other sector and threatened air quality and greenhouse gas (GHG) abatement target. In this work, we assessed the evolution of coal-fired power plants in China during 2010-2030 and the evolution of associated emissions for the same period by using a unit-based emission projection model which integrated the historical power plants information, turnover of the future power plant fleet, and the evolution of end-of-pipe control technologies. We found that, driven by the stringent environmental legislation, SO2, NOx, and PM2.5 emissions from China's coal-fired power plants decreased by 49%, 45%, and 24% respectively during 2010-2015, comparing to 14% increase of coal consumption and 15% increase in CO2 emissions. We estimated that under current national energy development planning, coal consumption and CO2 emissions from coal-fired power plants will continue to increase until 2030, in which against the China's Intended Nationally Determined Contributions (INDCs) targets. Early retirement of old and low-efficient power plants will cumulatively reduce 2.2 Pg CO2 emissions from the baseline scenario during 2016-2030, but still could not curb CO2 emissions from the peak before 2030. Owing to the implementation of "near zero" emission control policy, we projected that emissions of air pollutants will significantly decrease during the same period under all scenarios, indicating the decoupling trends of air pollutants and CO2 emissions. Although with limited direct emission reduction benefits, increasing operating hours of power plants could avoid 236 GW of new power plants construction, which could indirectly reduce emissions embodied in the construction activity. Our results identified a more sustainable pathway for China's coal-fired power plants, which could reduce air pollutant emissions, improve the energy efficiency, and slow down the construction of new units. However, continuous construction of new coal-fired power plants driven by increased electricity demand would pose a potential threat to climate change mitigation and China's peak carbon pledge, and more aggressive CO2 emission reduction policy should be implemented in the future.

NOx emissions in China: historical trends and future perspectives

NASA Astrophysics Data System (ADS)

Zhao, B.; Wang, S. X.; Liu, H.; Xu, J. Y.; Fu, K.; Klimont, Z.; Hao, J. M.; He, K. B.; Cofala, J.; Amann, M.

2013-10-01

Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995-2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4%, 34.0%, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64% and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector, and more than half is distributed equally between industry and transportation sectors. Selective catalytic reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy-duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020 and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to explore the impact of key factors on future emissions.

On-road emissions of light-duty vehicles in europe.

PubMed

Weiss, Martin; Bonnel, Pierre; Hummel, Rudolf; Provenza, Alessio; Manfredi, Urbano

2011-10-01

For obtaining type approval in the European Union, light-duty vehicles have to comply with emission limits during standardized laboratory emissions testing. Although emission limits have become more stringent in past decades, light-duty vehicles remain an important source of nitrogen oxides and carbon monoxide emissions in Europe. Furthermore, persisting air quality problems in many urban areas suggest that laboratory emissions testing may not accurately capture the on-road emissions of light-duty vehicles. To address this issue, we conduct the first comprehensive on-road emissions test of light-duty vehicles with state-of-the-art Portable Emission Measurement Systems. We find that nitrogen oxides emissions of gasoline vehicles as well as carbon monoxide and total hydrocarbon emissions of both diesel and gasoline vehicles generally remain below the respective emission limits. By contrast, nitrogen oxides emissions of diesel vehicles (0.93 ± 0.39 grams per kilometer [g/km]), including modern Euro 5 diesel vehicles (0.62 ± 0.19 g/km), exceed emission limits by 320 ± 90%. On-road carbon dioxide emissions surpass laboratory emission levels by 21 ± 9%, suggesting that the current laboratory emissions testing fails to accurately capture the on-road emissions of light-duty vehicles. Our findings provide the empirical foundation for the European Commission to establish a complementary emissions test procedure for light-duty vehicles. This procedure could be implemented together with more stringent Euro 6 emission limits in 2014. The envisaged measures should improve urban air quality and provide incentive for innovation in the automotive industry.

Does environmental policy affect scaling laws between population and pollution? Evidence from American metropolitan areas

PubMed Central

2017-01-01

Modern cities are engines of production, innovation, and growth. However, urbanization also increases both local and global pollution from household consumption and firms’ production. Do emissions change proportionately to city size or does pollution tend to outpace or lag urbanization? Do emissions scale differently with population versus economic growth or are emissions, population, and economic growth inextricably linked? How are the scaling relationships between emissions, population, and economic growth affected by environmental regulation? This paper examines the link between urbanization, economic growth and pollution using data from Metropolitan Statistical Areas (MSAs) in the United States between 1999 and 2011. We find that the emissions of local air pollution in these MSAs scale according to a ¾ power law with both population size and gross domestic product (GDP). However, the monetary damages from these local emissions scale linearly with both population and GDP. Counties that have previously been out of attainment with the local air quality standards set by the Clean Air Act show an entirely different relationship: local emissions scale according to the square root of population, while the monetary damages from local air pollution follow a 2/3rds power law with population. Counties out of attainment are subject to more stringent emission controls; we argue based on this that enforcement of the Clean Air Act induces sublinear scaling between emissions, damages, and city size. In contrast, we find that metropolitan GDP scales super-linearly with population in all MSAs regardless of attainment status. Summarizing, our findings suggest that environmental policy limits the adverse effects of urbanization without interfering with the productivity benefits that manifest in cities. PMID:28792949

Does environmental policy affect scaling laws between population and pollution? Evidence from American metropolitan areas.

PubMed

Muller, Nicholas Z; Jha, Akshaya

2017-01-01

Modern cities are engines of production, innovation, and growth. However, urbanization also increases both local and global pollution from household consumption and firms' production. Do emissions change proportionately to city size or does pollution tend to outpace or lag urbanization? Do emissions scale differently with population versus economic growth or are emissions, population, and economic growth inextricably linked? How are the scaling relationships between emissions, population, and economic growth affected by environmental regulation? This paper examines the link between urbanization, economic growth and pollution using data from Metropolitan Statistical Areas (MSAs) in the United States between 1999 and 2011. We find that the emissions of local air pollution in these MSAs scale according to a ¾ power law with both population size and gross domestic product (GDP). However, the monetary damages from these local emissions scale linearly with both population and GDP. Counties that have previously been out of attainment with the local air quality standards set by the Clean Air Act show an entirely different relationship: local emissions scale according to the square root of population, while the monetary damages from local air pollution follow a 2/3rds power law with population. Counties out of attainment are subject to more stringent emission controls; we argue based on this that enforcement of the Clean Air Act induces sublinear scaling between emissions, damages, and city size. In contrast, we find that metropolitan GDP scales super-linearly with population in all MSAs regardless of attainment status. Summarizing, our findings suggest that environmental policy limits the adverse effects of urbanization without interfering with the productivity benefits that manifest in cities.

Whole-Genome Microarray and Gene Deletion Studies Reveal Regulation of the Polyhydroxyalkanoate Production Cycle by the Stringent Response in Ralstonia eutropha H16

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

Brigham, CJ; Speth, DR; Rha, C

Poly(3-hydroxybutyrate) (PHB) production and mobilization in Ralstonia eutropha are well studied, but in only a few instances has PHB production been explored in relation to other cellular processes. We examined the global gene expression of wild-type R. eutropha throughout the PHB cycle: growth on fructose, PHB production using fructose following ammonium depletion, and PHB utilization in the absence of exogenous carbon after ammonium was resupplied. Our results confirm or lend support to previously reported results regarding the expression of PHB-related genes and enzymes. Additionally, genes for many different cellular processes, such as DNA replication, cell division, and translation, are selectivelymore » repressed during PHB production. In contrast, the expression levels of genes under the control of the alternative sigma factor sigma(54) increase sharply during PHB production and are repressed again during PHB utilization. Global gene regulation during PHB production is strongly reminiscent of the gene expression pattern observed during the stringent response in other species. Furthermore, a ppGpp synthase deletion mutant did not show an accumulation of PHB, and the chemical induction of the stringent response with DL-norvaline caused an increased accumulation of PHB in the presence of ammonium. These results indicate that the stringent response is required for PHB accumulation in R. eutropha, helping to elucidate a thus-far-unknown physiological basis for this process.« less

Low Noise Cruise Efficient Short Take-Off and Landing Transport Vehicle Study

NASA Technical Reports Server (NTRS)

Kim, Hyun D.; Berton, Jeffrey J.; Jones, Scott M.

2007-01-01

The saturation of the airspace around current airports combined with increasingly stringent community noise limits represents a serious impediment to growth in world aviation travel. Breakthrough concepts that both increase throughput and reduce noise impacts are required to enable growth in aviation markets. Concepts with a 25 year horizon must facilitate a 4x increase in air travel while simultaneously meeting community noise constraints. Attacking these horizon issues holistically is the concept study of a Cruise Efficient Short Take-Off and Landing (CESTOL) high subsonic transport under the NASA's Revolutionary Systems Concepts for Aeronautics (RSCA) project. The concept is a high-lift capable airframe with a partially embedded distributed propulsion system that takes a synergistic approach in propulsion-airframe-integration (PAI) by fully integrating the airframe and propulsion systems to achieve the benefits of both low-noise short take-off and landing (STOL) operations and efficient high speed cruise. This paper presents a summary of the recent study of a distributed propulsion/airframe configuration that provides low-noise STOL operation to enable 24-hour use of the untapped regional and city center airports to increase the capacity of the overall airspace while still maintaining efficient high subsonic cruise flight capability.

Impact on air quality of measures to reduce CO2 emissions from road traffic in Basel, Rotterdam, Xi'an and Suzhou

NASA Astrophysics Data System (ADS)

Keuken, M. P.; Jonkers, S.; Verhagen, H. L. M.; Perez, L.; Trüeb, S.; Okkerse, W.-J.; Liu, J.; Pan, X. C.; Zheng, L.; Wang, H.; Xu, R.; Sabel, C. E.

2014-12-01

Two traffic scenarios to reduce CO2 emissions from road traffic in two European cities (Basel and Rotterdam) and two Chinese cities (Xi'an and Suzhou) were evaluated in terms of their impact on air quality. The two scenarios, one modelling a reduction of private vehicle kilometres driven by 10% on urban streets and the other modelling the introduction of 50% electric-powered private vehicle kilometres on urban streets, were both compared to a scenario following “business-as-usual”: 2020-BAU. The annual average concentrations of NO2, PM2.5, PM10 and elemental carbon (EC) were modelled separately in busy street canyons, near urban motorways and in the remainder of the urban area. It was concluded that traffic-related CO2 emissions in 2020-BAU could be expected to remain at the levels of 2010 in Basel and Rotterdam, while in Xi'an and Suzhou to increase 30-50% due to growth in the traffic volume. Traffic-related CO2 emissions may be reduced by up to 5% and 25%, respectively using the first and second scenarios. Air pollution in the Chinese cities is a factor 3 to 5 higher than in the European cities in 2010 and 2020-BAU. The impact of both CO2 reduction scenarios on air quality in 2020-BAU is limited. In Europe, due to implementation of stringent emission standards in all sectors, air quality is expected to improve at both the urban background and near busy road traffic. In China, the regional background is expected to improve for EC, stabilize for PM2.5 and PM10, and decrease for NO2. The urban background follows this regional trend, while near busy road traffic, air pollution will remain elevated due to the considerable growth in traffic volume. A major constraint for modelling air quality in China is access to the input data required and lack of measurements at ground level for validation.

Review of high-sensitivity Radon studies

NASA Astrophysics Data System (ADS)

Wojcik, M.; Zuzel, G.; Simgen, H.

2017-10-01

A challenge in many present cutting-edge particle physics experiments is the stringent requirements in terms of radioactive background. In peculiar, the prevention of Radon, a radioactive noble gas, which occurs from ambient air and it is also released by emanation from the omnipresent progenitor Radium. In this paper we review various high-sensitivity Radon detection techniques and approaches, applied in the experiments looking for rare nuclear processes happening at low energies. They allow to identify, quantitatively measure and finally suppress the numerous sources of Radon in the detectors’ components and plants.

Polarization (ellipsometric) measurements of liquid condensate deposition and evaporation rates and dew points in flowing salt/ash-containing combustion gases

NASA Technical Reports Server (NTRS)

Seshadri, K.; Rosner, D. E.

1985-01-01

An application of an optical polarization technique in a combustion environment is demonstrated by following, in real-time, growth rates of boric oxide condensate on heated platinum ribbons exposed to seeded propane-air combustion gases. The results obtained agree with the results of earlier interference measurements and also with theoretical chemical vapor deposition predictions. In comparison with the interference method, the polarization technique places less stringent requirements on surface quality, which may justify the added optical components needed for such measurements.

77 FR 28927 - Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-16

...The U.S. Department of Energy (DOE) is amending its energy conservation standards for small, large, and very large water-cooled and evaporatively-cooled commercial package air conditioners, and variable refrigerant flow (VRF) water-source heat pumps less than 17,000 Btu/h. DOE is adopting new energy conservation standards for computer room air conditioners and VRF water-source heat pumps with a cooling capacity at or greater than 135,000 Btu/h and less than 760,000 Btu/h. Pursuant to the Energy Policy and Conservation Act of 1975 (EPCA), as amended, DOE must assess whether the uniform national standards for these covered equipment need to be updated each time the corresponding industry standard--the American National Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air- Conditioning Engineers (ASHRAE)/Illuminating Engineering Society of North America (IESNA) Standard 90.1 (ASHRAE Standard 90.1)--is amended, which most recently occurred on October 29, 2010. The levels DOE is adopting are the same as the efficiency levels specified in ASHRAE Standard 90.1-2010. DOE has determined that the ASHRAE Standard 90.1- 2010 efficiency levels for the equipment types listed above are more stringent than existing Federal energy conservation standards and will result in economic and energy savings compared existing energy conservation standards. Furthermore, DOE has concluded that clear and convincing evidence does not exist, as would justify more-stringent standard levels than the efficiency levels in ASHRAE Standard 90.1-2010 for any of the equipment classes. DOE is also updating the current Federal test procedures or, for certain equipment, adopting new test procedures to incorporate by reference the most current versions of the relevant industry test procedures specified in ASHRAE Standard 90.1- 2010. Furthermore, DOE is adopting additional test procedure provisions to include with modification certain instructions from Air- Conditioning, Heating, and Refrigeration Institute (AHRI) operations manuals in that organization's test procedures that would clarify the application of the DOE test procedures and harmonize DOE testing with the testing performed by industry.

Contaminant levels, source strengths, and ventilation rates in California retail stores.

PubMed

Chan, W R; Cohn, S; Sidheswaran, M; Sullivan, D P; Fisk, W J

2015-08-01

This field study measured ventilation rates and indoor air quality in 21 visits to retail stores in California. Three types of stores, such as grocery, furniture/hardware stores, and apparel, were sampled. Ventilation rates measured using a tracer gas decay method exceeded the minimum requirement of California's Title 24 Standard in all but one store. Concentrations of volatile organic compounds (VOCs), ozone, and carbon dioxide measured indoors and outdoors were analyzed. Even though there was adequate ventilation according to standard, concentrations of formaldehyde and acetaldehyde exceeded the most stringent chronic health guidelines in many of the sampled stores. The whole-building emission rates of VOCs were estimated from the measured ventilation rates and the concentrations measured indoor and outdoor. Estimated formaldehyde emission rates suggest that retail stores would need to ventilate at levels far exceeding the current Title 24 requirement to lower indoor concentrations below California's stringent formaldehyde reference level. Given the high costs of providing ventilation, effective source control is an attractive alternative. Field measurements suggest that California retail stores were well ventilated relative to the minimum ventilation rate requirement specified in the Building Energy Efficiency Standards Title 24. Concentrations of formaldehyde found in retail stores were low relative to levels found in homes but exceeded the most stringent chronic health guideline. Looking ahead, California is mandating zero energy commercial buildings by 2030. To reduce the energy use from building ventilation while maintaining or even lowering formaldehyde in retail stores, effective formaldehyde source control measures are vitally important. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Investigation of material improvements to mitigate the abrasive wear mechanism of concrete crosstie rail seat deterioration (RSD).

DOT National Transportation Integrated Search

2014-11-01

To meet the increasingly stringent design and performance requirements due to increasing cumulative : gross tonnages from heavy-haul freight operations, along with increased high-speed inter-city passenger : rail development, improvements in concrete...

Modules for estimating solid waste from fossil-fuel technologies

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

Crowther, M.A.; Thode, H.C. Jr.; Morris, S.C.

1980-10-01

Solid waste has become a subject of increasing concern to energy industries for several reasons. Increasingly stringent air and water pollution regulations result in a larger fraction of residuals in the form of solid wastes. Control technologies, particularly flue gas desulfurization, can multiply the amount of waste. With the renewed emphasis on coal utilization and the likelihood of oil shale development, increased amounts of solid waste will be produced. In the past, solid waste residuals used for environmental assessment have tended only to include total quantities generated. To look at environmental impacts, however, data on the composition of the solidmore » wastes are required. Computer modules for calculating the quantities and composition of solid waste from major fossil fuel technologies were therefore developed and are described in this report. Six modules have been produced covering physical coal cleaning, conventional coal combustion with flue gas desulfurization, atmospheric fluidized-bed combustion, coal gasification using the Lurgi process, coal liquefaction using the SRC-II process, and oil shale retorting. Total quantities of each solid waste stream are computed together with the major components and a number of trace elements and radionuclides.« less

Quantifying short-term and long-term health benefits of attaining ambient fine particulate pollution standards in Guangzhou, China

NASA Astrophysics Data System (ADS)

Lin, Hualiang; Liu, Tao; Xiao, Jianpeng; Zeng, Weilin; Li, Xing; Guo, Lingchuan; Xu, Yanjun; Zhang, Yonghui; Vaughn, Michael G.; Nelson, Erik J.; Qian, Zhengmin (Min); Ma, Wenjun

2016-07-01

In 2012, Chinese Environmental Bureau modified its National Ambient Air Quality Standards to include fine particulate matter (PM2.5). Recent air pollution monitoring data shows that numerous locations have exceeded this standard, which may have resulted in avoidable adverse health effects. For example, among the 74 Chinese cities with PM2.5 monitoring data in 2013, only three cities attained the annual air quality standard (35 μg/m3). This study aimed to quantify the potential short- and long-term health benefits from achieving the Chinese ambient air quality standard and WHO's air quality objectives. A generalized additive model was used to estimate the short-term association of mortality with changes in daily PM2.5 concentrations, based on which we estimated the potential premature mortality reduction that would have been achieved during the period of 2012-2015 if the daily air quality standard had been met in Guangzhou, China; we also estimated the avoidable deaths if attaining the annual air quality standard using the relative risk obtained from a previous cohort study. During the study period, there were 160 days exceeding the national daily PM2.5 standard (75 μg/m3) in Guangzhou, and the annual average concentration (47.7 μg/m3) was higher than the air quality standard of 35 μg/m3. Significant associations between PM2.5 and mortality were observed. An increase of 10 μg/m3 in PM2.5 was associated with increases in daily death counts of 0.95% (95% CI: 0.56%, 1.34%) in natural mortality, 1.31% (95% CI: 0.75%, 1.87%) in cardiovascular mortality, and 1.06% (95% CI: 0.19%, 1.94%) in respiratory mortality. The health benefits of attaining the national daily air quality standard of PM2.5 (75 μg/m3) would have prevented 143 [95% confidence interval (CI): 84, 203] fewer natural deaths, including 84 (95% CI: 48, 121) fewer cardiovascular deaths and 27 (95% CI: 5, 49) fewer respiratory deaths. Had the annual PM2.5 levels been reduced to 35 μg/m3, an estimated 3875 (95% CI: 1852, 6074) natural deaths, 2378 (95% CI: 800, 4230) cardiovascular deaths, and 227 (95% CI: -437, 1033) respiratory deaths could have been prevented. Even greater substantial mortality reductions could be achieved if the WHO's air quality objectives were met. Our study suggests that air pollution is significantly associated with mortality in Guangzhou, and more stringent air quality standards would significantly reduce air pollution-related premature mortality.

Non-Intrusive Laser-Induced Imaging for Speciation and Patternation in High Pressure Gas Turbine Combustors

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Zaller, Michelle M.; Hicks, Yolanda R.; Anderson, Robert C.

1999-01-01

The next generation of was turbine combustors for aerospace applications will be required to meet increasingly stringent constraints on fuel efficiency, noise abatement, and emissions. The power plants being designed to meet these constraints will operate at extreme conditions of temperature and pressure, thereby generating unique challenges to the previously employed diagnostic methodologies. Current efforts at NASA Glenn Research Center (GRC) utilize optically accessible, high pressure flametubes and sector combustor rigs to probe, via advanced nonintrusive laser techniques, the complex flowfields encountered in advanced combustor designs. The fuel-air mixing process is of particular concern for lowering NO(x) emissions generated in lean, premixed engine concepts. Using planar laser-induced fluorescence (PLIF) we have obtained real-time, detailed imaging of the fuel spray distribution for a number of fuel injector over a wide range of operational conditions that closely match those expected in the proposed propulsion systems. Using a novel combination of planar imaging, of fuel fluorescence and computational analysis that allows an examination of the flowfield from any perspective, we have produced spatially and temporally resolved fuel-air distribution maps. These maps provide detailed insight into the fuel injection at actual conditions never before possible, thereby greatly enhancing the evaluation of fuel injector performance and combustion phenomena.

Nonintrusive laser-induced imaging for speciation and patternation in high-pressure gas turbine combustors

NASA Astrophysics Data System (ADS)

Locke, Randy J.; Zaller, Michelle M.; Hicks, Yolanda R.; Anderson, Robert C.

1999-10-01

The next generation of ga turbine combustors for aerospace applications will be required to meet increasingly stringent constraints on fuel efficiency, noise abatement, and emissions. The power plants being designed to meet these constraints will operate at extreme conditions of temperature and pressure, thereby generating unique challenges to the previously employed diagnostic methodologies. Current efforts at NASA Glenn Research Center GRC utilize optically accessible, high-pressure flametubes and sector combustor rigs to probe, via advanced nonintrusive laser techniques, the complex flowfields encountered in advanced combustor designs. The fuel-air mixing process is of particular concern for lowering NOx emissions generated in lean, premixed engine concepts. Using planar laser-induced fluorescence we have obtained real- time, detailed imaging of the fuel spray distribution for a number of fuel injectors over a wide range of operational conditions that closely match those expected in the proposed propulsion systems. Using a novel combination of planar imaging of fuel fluorescence and computational analysis that allows an examination of the flowfield from any perspective, we have produced spatially and temporally resolved fuel-air distribution maps. These maps provide detailed insight into the fuel injection process at actual conditions never before possible, thereby greatly enhancing the evaluation of fuel injector performance and combustion phenomena.

Space Shuttle Solid Rocket Booster decelerator subsystem - Air drop test vehicle/B-52 design

NASA Technical Reports Server (NTRS)

Runkle, R. E.; Drobnik, R. F.

1979-01-01

The air drop development test program for the Space Shuttle Solid Rocket Booster Recovery System required the design of a large drop test vehicle that would meet all the stringent requirements placed on it by structural loads, safety considerations, flight recovery system interfaces, and sequence. The drop test vehicle had to have the capability to test the drogue and the three main parachutes both separately and in the total flight deployment sequence and still be low-cost to fit in a low-budget development program. The design to test large ribbon parachutes to loads of 300,000 pounds required the detailed investigation and integration of several parameters such as carrier aircraft mechanical interface, drop test vehicle ground transportability, impact point ground penetration, salvageability, drop test vehicle intelligence, flight design hardware interfaces, and packaging fidelity.

High Spatial Resolution Thermal Infrared Remote Sensing Data for Analysis of the Atlanta, Georgia, Urban Heat Island Effect and Its Impacts on the Environment

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.

2007-01-01

The twenty-first century is the first "urban century" according to the United Nations Development Program. The focus of cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In environmental terms, cities are the original producers of many of the global problems related to waste disposal, air and water pollution, and associated environmental and ecological challenges. Expansion of cities, both in population and areal extent, is a relentless process. In 2000, approximately 3 billion people representing about 40% of the global population, resided in urban areas. Urban population will continue to rise substantially over the next several decades according to UN estimates, and most of this growth will Occur in developing countries. The UN estimates that by 2025, 60% of the world's population will live in urban areas. As a consequence, the number of"megacities" (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand urban areas and what their impacts are on environmental, ecological and hydrologic resources, as well as on the local, regional, and even global climate. One of the more egregious side effects of urbanization is the increase in surface and air temperatures that lead to deterioration in air quality. In the United States, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency in 1997, nearly 300 counties in 34 states will not meet these new air quality standards for ground level ozone. Mitigation of the urban heat island (UHI) effect is actively being evaluated as a possible way to reduce ground ozone levels in cities and assist states in improving air quality. Foremost in the analysis of how the UHI affects air quality and other environmental factors is the use of remote sensing technology and data to characterize urban land covers in sufficient detail to quantifiably measure the impact of increased urban heating on air quality. The urban landscape impacts surface thermal energy exchanges that determine development of the UHI. This paper will illustrate how we are using high spatial remote sensing data collected over the Atlanta, Georgia metropolitan area in conjunction with other geographic information, to perform a detailed urban land cover classification and to determine the contribution of these land covers to the urban heat island effect. Also, the spatial arrangement of the land covers and the impact on urban heating from these selected patterns of development are evaluated. Additionally, this paper will show how these data are being used as inputs to improve air quality modeling for Atlanta, including potential benefits from UHI mitigation.

Air quality and respiratory health in Delhi.

PubMed

Nidhi; Jayaraman, Girija

2007-12-01

Delhi is an instructive location for studying the impact of air pollution since it is a rapidly expanding centre of government, trade commerce and industry. We have made an attempt to (1) determine the association between environmental pollution and respiratory morbidity in Delhi for the period 1998-2004, (2) assess the impact on hospital admission of the implementation of recent governmental regulations and (3) calculate the relative risk of hospitalization due to respiratory ailments caused by air pollutants. Seven hospitals from different parts of Delhi were selected. The pollution profiles of these areas were assessed and subsequently Poisson regression model was performed for the patient population. There was a remarkable decrease in monthly average concentration of sulphur dioxide (from 17.9 to 11.1 microg m(-3)) and increase in monthly average concentration of nitrogen dioxide (from 34.2 to 49.1 microg m(-3)) after the newly introduced regulations. Particulates were observed to have marginal fall in their concentration but still remained above the permissible limits. Gaseous pollutants, in spite of being at a level lower than the permissible level, showed more consistent significant association with respiratory admissions. The relative risks of hospitalization due to respiratory diseases were in the range of 1.07-2.82 in residential cum commercial areas. Comparative study of pre and post new stringent governmental regulation showed significant positive association of NO(2) with respiratory disorders in southern (RR: 1.10; CI: 1.09-1.12) and northern regions (RR: 1.33; CI: 1.27-1.39), both mixed use areas. In spite of the improvement in the air quality, the associated health effects were found to be substantial.

Impact of Middle Eastern dust storms on indoor and outdoor composition of bioaerosol

NASA Astrophysics Data System (ADS)

Goudarzi, Gholamreza; Soleimani, Zahra; Sorooshian, Armin; Marzouni, Mohammad Bagherian; Maleki, Heidar

2016-08-01

The presence of microbes in airborne aerosol particles, especially dust, is a major public health concern in desert regions. This study is the first of its kind to examine the effect of dust storms on indoor and outdoor microbial air quality at a hospital on the western side of Iran (city of Ahvaz), which is notorious for being highly vulnerable to dust emissions. Air samples were collected inside and outside of the hospital environment for six months, with the unique advantage of this study being that the region and duration of measurements allow for a clear comparison between dusty and normal days. On normal days, the average concentrations (outdoor/indoor) of bacteria and fungi were 423/329 cfu m-3 and 596/386 cfu m-3, respectively, which increased to 1257/406 cfu m-3 and 1116/550 cfu m-3 on dust event days. Indoor/Outdoor ratios for bacteria and fungi are lower on dust event days (0.26-0.60) versus normal days (0.44-0.95). Bacillus spp., Micrococcus spp., Streptomyces spp., and Staphylococcus spp. were the dominant bacteria both indoors and outdoors on normal and dust event days. Gram positive bacteria exhibited higher concentrations than Gram negative bacteria in both outdoor and indoor air samples as well as during both normal and dust event days. The data suggest that Gram positive bacteria are more resistant to undesirable outdoor conditions (e.g., high incident solar radiation) as compared to Gram negative ones. These results have implications for other populated arid regions where more stringent control of indoor air quality can greatly benefit public health.

Constraining Microwave Emission from Extensive Air Showers via the MIDAS Experiment

NASA Astrophysics Data System (ADS)

Richardson, Matthew; Privitera, Paolo

2017-01-01

Ultra high energy cosmic rays (UHECRs) are accelerated by the most energetic processes in the universe. Upon entering Earth’s atmosphere they produce particle showers known as extensive air showers (EASs). Observatories like the Pierre Auger Observatory sample the particles and light produced by the EASs through large particle detector arrays or nitrogen fluorescence detectors to ascertain the fundamental properties of UHECRs. The large sample of high quality data provided by the Pierre Auger Observatory can be attributed to the hybrid technique which utilizes the two aforementioned techniques simultaneously; however, the limitation of only being able to observe nitrogen fluorescence from EASs on clear moonless nights yields a limited 10% duty cycle for the hybrid technique. One proposal for providing high quality data at increased statistics is the observation of isotropic microwave emission from EASs, as such emission would be observed with a 100% duty cycle. Measurements of microwave emission from laboratory air plasmas conducted by Gorham et al. (2008) produced promising results indicating that the microwave emission should be observable using inexpensive detectors. The Microwave Detection of Air Showers (MIDAS) experiment was built at the University of Chicago to characterize the isotropic microwave emission from EASs and has collected 359 days of observational data at the location of the Pierre Auger experiment. We have performed a time coincidence analysis between this data and data from Pierre Auger and we report a null result. This result places stringent limits on microwave emission from EASs and demonstrates that the laboratory measurements of Gorham et al. (2008) are not applicable to EASs, thus diminishing the feasibility of using isotropic microwave emission to detect EASs.

Field Testing of Compartmentalization Methods for Multifamily Construction

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

Ueno, K.; Lstiburek, J. W.

2015-03-01

The 2012 International Energy Conservation Code (IECC) has an airtightness requirement of 3 air changes per hour at 50 Pascals test pressure (3 ACH50) for single-family and multifamily construction (in climate zones 3–8). The Leadership in Energy & Environmental Design certification program and ASHRAE Standard 189 have comparable compartmentalization requirements. ASHRAE Standard 62.2 will soon be responsible for all multifamily ventilation requirements (low rise and high rise); it has an exceptionally stringent compartmentalization requirement. These code and program requirements are driving the need for easier and more effective methods of compartmentalization in multifamily buildings.

Are EPA's proposed revisions to the PM standards appropriate?

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

Lucinda Minton Langworthy

2006-06-15

In 1997 then-US Environmental Protection Agency (EPA) Administrator Carol Browner adopted new National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5). Browner recognized that 'there is uncertainty in the characterization of health effects attributable to exposure to ambient PM.' As a result, President Clinton promised to review the scientific basis for those standards prior to their implementation. Recently, before EPA has even promulgated rules concerning implementation of those standards, the agency proposed to revise those standards to make them significantly more stringent. Are the proposed revisions to the standards appropriate? The author argues. 41 refs.

Barbiturates

USGS Publications Warehouse

Thomas, N.J.

1999-01-01

Barbiturate products are commonly used to euthanize domestic animals. The primary active component in euthanasia solutions is sodium pentobarbital, but some products also contain other minor ingredients (Fig. 48.1).Euthanasia solutions are generally injected intravenously in domestic animals; therefore, after death, the solutions will be most concentrated in the blood and the highly vascularized organs, such as the liver or spleen, of the euthanized animal.Euthanized carcasses that are available as carrion pose a hazard to scavenging birds and mammals. Large domestic animal carcasses, such as horses, that are not used for food or rendering but that are sufficiently valuable (monetarily or psychologically) to warrant veterinary services and euthanasia drugs are the most common sources of barbiturate poisoning in scavengers. In one instance in British Columbia, a single cow carcass was responsible for poisoning 29 bald eagles.Circumstances that interfere with burial, such as frozen winter soil or bulky carcasses, result in euthanized carcasses being available for scavenger species. This problem could increase in the future if more stringent air-quality standards restrict carcass incineration.

A transdisciplinary approach to understanding the health effects of wildfire and prescribed fire smoke regimes

NASA Astrophysics Data System (ADS)

Williamson, G. J.; Bowman, D. M. J. S.; Price, O. F.; Henderson, S. B.; Johnston, F. H.

2016-12-01

Prescribed burning is used to reduce the occurrence, extent and severity of uncontrolled fires in many flammable landscapes. However, epidemiologic evidence of the human health impacts of landscape fire smoke emissions is shaping fire management practice through increasingly stringent environmental regulation and public health policy. An unresolved question, critical for sustainable fire management, concerns the comparative human health effects of smoke from wild and prescribed fires. Here we review current knowledge of the health effects of landscape fire emissions and consider the similarities and differences in smoke from wild and prescribed fires with respect to the typical combustion conditions and fuel properties, the quality and magnitude of air pollution emissions, and the potential for dispersion to large populations. We further examine the interactions between these considerations, and how they may shape the longer term smoke regimes to which populations are exposed. We identify numerous knowledge gaps and propose a conceptual framework that describes pathways to better understanding of the health trade-offs of prescribed and wildfire smoke regimes.

Cleaner fuels for ships provide public health benefits with climate tradeoffs.

PubMed

Sofiev, Mikhail; Winebrake, James J; Johansson, Lasse; Carr, Edward W; Prank, Marje; Soares, Joana; Vira, Julius; Kouznetsov, Rostislav; Jalkanen, Jukka-Pekka; Corbett, James J

2018-02-06

We evaluate public health and climate impacts of low-sulphur fuels in global shipping. Using high-resolution emissions inventories, integrated atmospheric models, and health risk functions, we assess ship-related PM 2.5 pollution impacts in 2020 with and without the use of low-sulphur fuels. Cleaner marine fuels will reduce ship-related premature mortality and morbidity by 34 and 54%, respectively, representing a ~ 2.6% global reduction in PM 2.5 cardiovascular and lung cancer deaths and a ~3.6% global reduction in childhood asthma. Despite these reductions, low-sulphur marine fuels will still account for ~250k deaths and ~6.4 M childhood asthma cases annually, and more stringent standards beyond 2020 may provide additional health benefits. Lower sulphur fuels also reduce radiative cooling from ship aerosols by ~80%, equating to a ~3% increase in current estimates of total anthropogenic forcing. Therefore, stronger international shipping policies may need to achieve climate and health targets by jointly reducing greenhouse gases and air pollution.

Taking Action on Air Pollution Control in the Beijing-Tianjin-Hebei (BTH) Region: Progress, Challenges and Opportunities

PubMed Central

Wang, Li; Zhang, Fengying; Pilot, Eva; Yu, Jie; Holdaway, Jennifer; Yang, Linsheng; Li, Yonghua; Wang, Wuyi; Vardoulakis, Sotiris; Krafft, Thomas

2018-01-01

Due to rapid urbanization, industrialization and motorization, a large number of Chinese cities are affected by heavy air pollution. In order to explore progress, remaining challenges, and sustainability of air pollution control in the Beijing-Tianjin-Hebei (BTH) region after 2013, a mixed method analysis was undertaken. The quantitative analysis comprised an overview of air quality management in the BTH region. Semi-structured expert interviews were conducted with 12 stakeholders from various levels of government and research institutions who played substantial roles either in decision-making or in research and advising on air pollution control in the BTH region. The results indicated that with the stringent air pollution control policies, the air quality in BTH meets the targets of the Air Pollution Prevention and Control Action Plan. However, improvements vary across the region and for different pollutants. Although implementation has been decisive and was at least in parts effectively enforced, significant challenges remained with regard to industrial and traffic emission control, and national air quality limits continued to be significantly exceeded and competing development interests remained mainly unsolved. There were also concerns about the sustainability of the current air pollution control measures especially for industries due to the top-down enforcement, and the associated large burden of social cost including unemployment and social inequity resulting industrial restructuring. Better mechanisms for ensuring cross-sectoral coordination and for improved central-local government communication were suggested. Further suggestions were provided to improve the conceptual design and effective implementation of respective air pollution control strategies in BTH. Our study highlights some of the major hurdles that need to be addressed to succeed with a comprehensive air pollution control management for the Chinese mega-urban agglomerations. PMID:29425189

Taking Action on Air Pollution Control in the Beijing-Tianjin-Hebei (BTH) Region: Progress, Challenges and Opportunities.

PubMed

Wang, Li; Zhang, Fengying; Pilot, Eva; Yu, Jie; Nie, Chengjing; Holdaway, Jennifer; Yang, Linsheng; Li, Yonghua; Wang, Wuyi; Vardoulakis, Sotiris; Krafft, Thomas

2018-02-09

Due to rapid urbanization, industrialization and motorization, a large number of Chinese cities are affected by heavy air pollution. In order to explore progress, remaining challenges, and sustainability of air pollution control in the Beijing-Tianjin-Hebei (BTH) region after 2013, a mixed method analysis was undertaken. The quantitative analysis comprised an overview of air quality management in the BTH region. Semi-structured expert interviews were conducted with 12 stakeholders from various levels of government and research institutions who played substantial roles either in decision-making or in research and advising on air pollution control in the BTH region. The results indicated that with the stringent air pollution control policies, the air quality in BTH meets the targets of the Air Pollution Prevention and Control Action Plan. However, improvements vary across the region and for different pollutants. Although implementation has been decisive and was at least in parts effectively enforced, significant challenges remained with regard to industrial and traffic emission control, and national air quality limits continued to be significantly exceeded and competing development interests remained mainly unsolved. There were also concerns about the sustainability of the current air pollution control measures especially for industries due to the top-down enforcement, and the associated large burden of social cost including unemployment and social inequity resulting industrial restructuring. Better mechanisms for ensuring cross-sectoral coordination and for improved central-local government communication were suggested. Further suggestions were provided to improve the conceptual design and effective implementation of respective air pollution control strategies in BTH. Our study highlights some of the major hurdles that need to be addressed to succeed with a comprehensive air pollution control management for the Chinese mega-urban agglomerations.

Is smog innocuous? Air pollution and cardiovascular disease.

PubMed

Mishra, Sundeep

Air pollution is a significant environmental and health hazard. Earlier studies had examined the adverse health effects associated with short- and long-term exposure to particulate matter on respiratory disease. However, later studies demonstrated that was actually cardiovascular disease that accounted for majority of mortality. Furthermore, it was not gaseous pollutants like oxides of nitrate, sulfur, carbon mono-oxide or ozone but the particulate matter or PM, of fine or coarse size (PM 2.5 and PM 10 ) which was linearly associated with mortality; PM 2.5 with long term and PM 10 with short term. Several cardiovascular diseases are associated with pollution; acute myocardial infarction, heart failure, cardiac arrhythmias, atherosclerosis and cardiac arrest. The ideal way to address this problem is by adhering to stringent environmental standards of pollutants but some individual steps like choosing to stay indoors (on high pollution days), reducing outdoor air permeation to inside, purifying indoor air using air filters, and also limiting outdoor physical activity near source of air pollution can help. Nutritional anti-oxidants like statins or Mediterranean diet, and aspirin have not been associated with reduced risk but specific nutritional agents like broccoli, cabbage, cauliflower or brussels sprouts, fish oil supplement may help. Use of face-mask has been controversial but may be useful if particulate matter load is higher. Copyright © 2017. Published by Elsevier B.V.

Environmental Life Cycle Assessment and Cost Analysis of Bath, NY Wastewater Treatment Plant: Potential Upgrade Implications

EPA Science Inventory

Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pot...

SEARCH FOR GAMMA RAYS ABOVE 100 TeV FROM THE CRAB NEBULA WITH THE TIBET AIR SHOWER ARRAY AND THE 100 m{sup 2} MUON DETECTOR

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

Amenomori, M.; Bi, X. J.; Chen, W. Y.

2015-11-10

A 100 m{sup 2} muon detector (MD) was successfully constructed under the existing Tibet air shower (AS) array in the late fall of 2007. The sensitivity of the Tibet AS array to cosmic gamma rays can be improved by selecting muon-poor events with the MD. Our MC simulation of the MD response reasonably agrees with the experimental data in terms of the charge distribution for one-muon events and the background rejection power. Using the data collected by the Tibet AS array and the 100 m{sup 2} MD taken from 2008 March to 2010 February, we search for continuous gamma-ray emissionmore » from the Crab Nebula above ∼100 TeV. No significant excess is found, and the most stringent upper limit is obtained above 140 TeV.« less

76 FR 37407 - Energy Conservation Program: Energy Conservation Standards for Residential Furnaces and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-27

...The Energy Policy and Conservation Act of 1975 (EPCA), as amended, prescribes energy conservation standards for various consumer products and certain commercial and industrial equipment, including residential furnaces and residential central air conditioners and heat pumps. EPCA also requires the U.S. Department of Energy (DOE) to determine whether more-stringent, amended standards for these products would be technologically feasible and economically justified, and would save a significant amount of energy. In this direct final rule, DOE adopts amended energy conservation standards for residential furnaces and for residential central air conditioners and heat pumps. A notice of proposed rulemaking that proposes identical energy efficiency standards is published elsewhere in this issue of the Federal Register. If DOE receives adverse comment and determines that such comment may provide a reasonable basis for withdrawing the direct final rule, this final rule will be withdrawn, and DOE will proceed with the proposed rule.

76 FR 37549 - Energy Conservation Program: Energy Conservation Standards for Residential Furnaces and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-27

...The Energy Policy and Conservation Act of 1975 (EPCA), as amended, prescribes energy conservation standards for various consumer products and certain commercial and industrial equipment, including residential furnaces and residential central air conditioners and heat pumps. EPCA also requires the U.S. Department of Energy (DOE) to determine whether more-stringent, amended standards for these products would be technologically feasible and economically justified, and would save a significant amount of energy. In this notice, DOE proposes energy conservation standards for residential furnaces and for residential central air conditioners and heat pumps identical to those set forth in a direct final rule published elsewhere in today's Federal Register. If DOE receives adverse comment and determines that such comment may provide a reasonable basis for withdrawing the direct final rule, DOE will publish a notice withdrawing the direct final rule and will proceed with this proposed rule.

High Spatial Resolution Thermal Remote Sensing of the Urban Heat Island Effect: Assessment of Risks to Human Health and Development of Mitigation Strategies for Sustainable Cities

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Luvall, Jeffrey C.; Rickman, Douglas L.; Estes, Maurice G., Jr.; Laymon, Charles A.; Crosson, William; Howell, Burgess F.; Gillani, Noor V.; Arnold, James E. (Technical Monitor)

2002-01-01

The growth of cities, both in population and in areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 80% of the world's population will live in cities. One of the more egregious side effects of urbanization is the deterioration in air quality as a result of increased vehicular traffic, industrialization and related activities. In the United States alone, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency (EPA) in 1997, nearly 300 counties in 34 states will not meet the new air quality standards for ground level ozone. The mitigation of one the physical/environmental characteristics of urbanization known as the urban heat island (UHI) effect, is now being looked at more closely as a possible way to bring down ground level ozone levels in cities and assist states in improving air quality. The UHI results from the replacement of "natural" land covers (e.g., trees, grass) with urban land surface types, such as pavement and buildings. Heat stored in these surfaces is released into the air and results in a "dome" of elevated air temperatures that presides over cities. The effect of this dome of elevated air temperatures is known as the UHI, which is most prevalent about 2-3 hours after sunset on days with intense solar radiation and calm winds. Given the local and regional impacts of the UHI, there are significant potential affects on human health, particularly as related to heat stress and ozone on body temperature regulation and on the cardiovascular and respiratory systems. In this study we are using airborne and satellite remote sensing data to analyze how differences in the urban landscape influence or drive the development of the UHI over four U.S. cities. Additionally, we are assessing what the potential impact is on risks to human health, and developing mitigation strategies to make urban areas more environmentally sustainable.

Remote Sensing of the Urban Heat Island Effect: Assessment of Risks to Human Health and Development of Mitigation Strategies for Sustainable Cities

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Luvall, Jeffrey C.; Rickman, Douglas L.; Estes, Maurice G., Jr.; Laymon, Charles A.; Crosson, William; Howell, Burgess F.; Gillani, Noor V.; Arnold, James E. (Technical Monitor)

2001-01-01

The growth of cities, both in population and in areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 80% of the world's population will live in cities. One of the more egregious side effects of urbanization is the deterioration in air quality as a result of increased vehicular traffic, industrialization and related activities. In the United States alone, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency (EPA) in 1997, nearly 300 counties in 34 states will not meet the new air quality standards for ground level ozone. The mitigation of one the physical/environmental characteristics of urbanization known as the urban heat island (UHI) effect, is now being looked at more closely as a possible way to bring down ground level ozone levels in cities and assist states in improving air quality. The UHI results from the replacement of "natural" land covers (e.g., trees, grass) with urban land surface types, such as pavement and buildings. Heat stored in these surfaces is released into the air and results in a "dome" of elevated air temperatures that presides over cities. The effect of this dome of elevated air temperatures is known as the UHI, which is most prevalent about 2-3 hours after sunset on days with intense solar radiation and calm winds. Given the local and regional impacts of the UHI, there are significant potential affects on human health, particularly as related to heat stress and ozone on body temperature regulation and on the cardiovascular and respiratory systems. In this study we are using airborne and satellite remote sensing data to analyze how differences in the urban landscape influence or drive the development of the UHI over four U.S. cities. Additionally, we are assessing what the potential impact is on risks to human health, and developing mitigation strategies to make urban areas more environmentally sustainable.

Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact

NASA Astrophysics Data System (ADS)

Wang, T.; Nie, W.; Gao, J.; Xue, L. K.; Gao, X. M.; Wang, X. F.; Qiu, J.; Poon, C. N.; Meinardi, S.; Blake, D.; Wang, S. L.; Ding, A. J.; Chai, F. H.; Zhang, Q. Z.; Wang, W. X.

2010-08-01

This paper presents the first results of the measurements of trace gases and aerosols at three surface sites in and outside Beijing before and during the 2008 Olympics. The official air pollution index near the Olympic Stadium and the data from our nearby site revealed an obvious association between air quality and meteorology and different responses of secondary and primary pollutants to the control measures. Ambient concentrations of vehicle-related nitrogen oxides (NOx) and volatile organic compounds (VOCs) at an urban site dropped by 25% and 20-45% in the first two weeks after full control was put in place, but the levels of ozone, sulfate and nitrate in PM2.5 increased by 16%, 64%, 37%, respectively, compared to the period prior to the full control; wind data and back trajectories indicated the contribution of regional pollution from the North China Plain. Air quality (for both primary and secondary pollutants) improved significantly during the Games, which were also associated with the changes in weather conditions (prolonged rainfall, decreased temperature, and more frequent air masses from clean regions). A comparison of the ozone data at three sites on eight ozone-pollution days, when the air masses were from the southeast-south-southwest sector, showed that regional pollution sources contributed >34-88% to the peak ozone concentrations at the urban site in Beijing. Regional sources also contributed significantly to the CO concentrations in urban Beijing. Ozone production efficiencies at two sites were low (~3 ppbv/ppbv), indicating that ozone formation was being controlled by VOCs. Compared with data collected in 2005 at a downwind site, the concentrations of ozone, sulfur dioxide (SO2), total sulfur (SO2+PM2.5 sulfate), carbon monoxide (CO), reactive aromatics (toluene and xylenes) sharply decreased (by 8-64%) in 2008, but no significant changes were observed for the concentrations of PM2.5, fine sulfate, total odd reactive nitrogen (NOy), and longer lived alkanes and benzene. We suggest that these results indicate the success of the government's efforts in reducing emissions of SO2, CO, and VOCs in Beijing, but increased regional emissions during 2005-2008. More stringent control of regional emissions will be needed for significant reductions of ozone and fine particulate pollution in Beijing.

Alcohol-fueled vehicles: An alternative fuels vehicle, emissions, and refueling infrastructure technology assessment

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

McCoy, G.A.; Kerstetter, J.; Lyons, J.K.

1993-06-01

Interest in alternative motor vehicle fuels has grown tremendously over the last few years. The 1990 Clean Air Act Amendments, the National Energy Policy Act of 1992 and the California Clean Air Act are primarily responsible for this resurgence and have spurred both the motor fuels and vehicle manufacturing industries into action. For the first time, all three U.S. auto manufacturers are offering alternative fuel vehicles to the motoring public. At the same time, a small but growing alternative fuels refueling infrastructure is beginning to develop across the country. Although the recent growth in alternative motor fuels use is impressive,more » their market niche is still being defined. Environmental regulations, a key driver behind alternative fuel use, is forcing both car makers and the petroleum industry to clean up their products. As a result, alternative fuels no longer have a lock on the clean air market and will have to compete with conventional vehicles in meeting stringent future vehicle emission standards. The development of cleaner burning gasoline powered vehicles has signaled a shift in the marketing of alternative fuels. While they will continue to play a major part in the clean vehicle market, alternative fuels are increasingly recognized as a means to reduce oil imports. This new role is clearly defined in the National Energy Policy Act of 1992. The Act identifies alternative fuels as a key strategy for reducing imports of foreign oil and mandates their use for federal and state fleets, while reserving the right to require private and municipal fleet use as well.« less

Nutrient Removal and Resource Recovery: Effect on Life Cycle Cost and Environmental Impacts of Small Scale Wastewater Treatment

EPA Science Inventory

Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pote...

Climate, Health, Agricultural and Economic Impacts of Tighter Vehicle-Emission Standards

NASA Technical Reports Server (NTRS)

Shindell, Drew; Faluvegi, Greg; Walsh, Michael; Anenberg, Susan C.; VanDingen, Rita; Muller, Nicholas Z.; Austin, Jeff; Koch, Dorothy; Milly, George

2011-01-01

Non-CO2 air pollutants from motor vehicles have traditionally been controlled to protect air quality and health, but also affect climate. We use global composition climate modelling to examine the integrated impacts of adopting stringent European on-road vehicle-emission standards for these pollutants in 2015 in many developing countries. Relative to no extra controls, the tight standards lead to annual benefits in 2030 and beyond of 120,000-280,000 avoided premature air pollution-related deaths, 6.1-19.7 million metric tons of avoided ozone-related yield losses of major food crops, $US0.6-2.4 trillion avoided health damage and $US1.1-4.3 billion avoided agricultural damage, and mitigation of 0.20 (+0.14/-0.17) C of Northern Hemisphere extratropical warming during 2040-2070. Tighter vehicle-emission standards are thus extremely likely to mitigate short-term climate change in most cases, in addition to providing large improvements in human health and food security. These standards will not reduce CO2 emissions, however, which is required to mitigate long-term climate change.

Real-time vehicle emissions monitoring using a compact LiDAR system and conventional instruments: first results of an experimental campaign in a suburban area in southern Italy

NASA Astrophysics Data System (ADS)

Parracino, Stefano; Richetta, Maria; Gelfusa, Michela; Malizia, Andrea; Bellecci, Carlo; De Leo, Leonardo; Perrimezzi, Carlo; Fin, Alessandro; Forin, Marco; Giappicucci, Francesca; Grion, Massimo; Marchese, Giuseppe; Gaudio, Pasquale

2016-10-01

Urban air pollution causes deleterious effects on human health and the environment. To meet stringent standards imposed by the European Commission, advanced measurement methods are required. Remote sensing techniques, such as light detection and ranging (LiDAR), can be a valuable option for evaluating particulate matter (PM), emitted by vehicles in urban traffic, with high sensitivity and in shorter time intervals. Since air quality problems persist not only in large urban areas, a measuring campaign was specifically performed in a suburban area of Crotone, Italy, using both a compact LiDAR system and conventional instruments for real-time vehicle emissions monitoring along a congested road. First results reported in this paper show a strong dependence between variations of LiDAR backscattering signals and traffic-related air pollution levels. Moreover, time-resolved LiDAR data averaged in limited regions, directly above conventional monitoring stations at the border of an intersection, were found to be linearly correlated to the PM concentration levels with a correlation coefficient between 0.75 and 0.84.

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

Greenblatt, Jeffery B.

A California Greenhouse Gas Inventory Spreadsheet (GHGIS) model was developed to explore the impact of combinations of state policies on state greenhouse gas (GHG) and regional criteria pollutant emissions. The model included representations of all GHG- emitting sectors of the California economy (including those outside the energy sector, such as high global warming potential gases, waste treatment, agriculture and forestry) in varying degrees of detail, and was carefully calibrated using available data and projections from multiple state agencies and other sources. Starting from basic drivers such as population, numbers of households, gross state product, numbers of vehicles, etc., the modelmore » calculated energy demands by type (various types of liquid and gaseous hydrocarbon fuels, electricity and hydrogen), and finally calculated emissions of GHGs and three criteria pollutants: reactive organic gases (ROG), nitrogen oxides (NOx), and fine (2.5 ?m) particulate matter (PM2.5). Calculations were generally statewide, but in some sectors, criteria pollutants were also calculated for two regional air basins: the South Coast Air Basin (SCAB) and the San Joaquin Valley (SJV). Three scenarios were developed that attempt to model: (1) all committed policies, (2) additional, uncommitted policy targets and (3) potential technology and market futures. Each scenario received extensive input from state energy planning agencies, in particular the California Air Resources Board. Results indicate that all three scenarios are able to meet the 2020 statewide GHG targets, and by 2030, statewide GHG emissions range from between 208 and 396 MtCO2/yr. However, none of the scenarios are able to meet the 2050 GHG target of 85 MtCO2/yr, with emissions ranging from 188 to 444 MtCO2/yr, so additional policies will need to be developed for California to meet this stringent future target. A full sensitivity study of major scenario assumptions was also performed. In terms of criteria pollutants, targets were less well-defined, but while all three scenarios were able to make significant reductions in ROG, NOx and PM2.5 both statewide and in the two regional air basins, they may nonetheless fall short of what will be required by future federal standards. Specifically, in Scenario 1, regional NOx emissions are approximately three times the estimated targets for both 2023 and 2032, and in Scenarios 2 and 3, NOx emissions are approximately twice the estimated targets. Further work is required in this area, including detailed regional air quality modeling, in order to determine likely pathways for attaining these stringent targets.« less

Projections of Future Summertime Ozone over the U.S.

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

Pfister, G. G.; Walters, Stacy; Lamarque, J. F.

This study uses a regional fully coupled chemistry-transport model to assess changes in surface ozone over the summertime U.S. between present and a 2050 future time period at high spatial resolution (12 km grid spacing) under the SRES A2 climate and RCP8.5 anthropogenic pre-cursor emission scenario. The impact of predicted changes in climate and global background ozone is estimated to increase surface ozone over most of the U.S; the 5th - 95th percentile range for daily 8-hour maximum surface ozone increases from 31-79 ppbV to 30-87 ppbV between the present and future time periods. The analysis of a set ofmore » meteorological drivers suggests that these mostly will add to increasing ozone, but the set of simulations conducted does not allow to separate this effect from that through enhanced global background ozone. Statistically the most robust positive feedbacks are through increased temperature, biogenic emissions and solar radiation. Stringent emission controls can counteract these feedbacks and if considered, we estimate large reductions in surface ozone with the 5th-95th percentile reduced to 27-55 ppbV. A comparison of the high-resolution projections to global model projections shows that even though the global model is biased high in surface ozone compared to the regional model and compared to observations, both the global and the regional model predict similar changes in ozone between the present and future time periods. However, on smaller spatial scales, the regional predictions show more pronounced changes between urban and rural regimes that cannot be resolved at the coarse resolution of global model. In addition, the sign of the changes in overall ozone mixing ratios can be different between the global and the regional predictions in certain regions, such as the Western U.S. This study confirms the key role of emission control strategies in future air quality predictions and demonstrates the need for considering degradation of air quality with future climate change in emission policy making. It also illustrates the need for high resolution modeling when the objective is to address regional and local air quality or establish links to human health and society.« less

Application of Glow Discharge Plasma to Alter Surface Properties of Materials

NASA Technical Reports Server (NTRS)

Trigwell, Steve; Buhler, Charles R.; Calle, Carlos I.

2005-01-01

Some polymer materials that are considered important for spaceport operations are rendered noncompliant when subjected to the Kennedy Space Center (KSC) Standard electrostatic testing. These materials operate in stringent environmental conditions, such as high humidity. Treating materials that fail electrostatic testing and altering their surface properties so that they become compliant would result in considerable cost savings. Significant improvement in electrostatic dissipation of Saf-T-Vu PVC after treatment with air Atmospheric Plasma Glow Discharge (APGD) was observed and the material now passed the KSC electrostatic test. The O:C ratio on the surface, as monitored by X-ray Photoelectron Spectroscopy, increased from 0.165 tO 0.275 indicating enhanced oxidation, and surface contact angle measurements decreased from 107.5 to 72.6 showing increased hydrophilicity that accounted for the increased conductivity. Monitoring of the aging showed that the materials hydrophobic recovery resulted in it failing the electrostatic test 30 hours after treatment. This was probably due to the out-diffusion of the added Zn, Ba, and Cd salt stabilizers detected on the surface and/or diffusion of low molecular weight oligomers. On going work includes improving the long term hydrophilicity by optimizing the APGD process with different gas mixtures. Treatment of other spaceport materials is also presented.

US major crops’ uncertain climate change risks and greenhouse gas mitigation benefits

DOE PAGES

Wing, Ian Sue; Monier, Erwan; Stern, Ari; ...

2015-10-28

In this study, we estimate the costs of climate change to US agriculture, and associated potential benefits of abating greenhouse gas emissions. Five major crops' yield responses to climatic variation are modeled empirically, and the results combined with climate projections for a no-policy, high-warming future, as well as moderate and stringent mitigation scenarios. Unabated warming reduces yields of wheat and soybeans by 2050, and cotton by 2100, but moderate warming increases yields of all crops except wheat. Yield changes are monetized using the results of economic simulations within an integrated climate-economy modeling framework. Uncontrolled warming's economic effects on major cropsmore » are slightly positive—annual benefits <$4 B. These are amplified by emission reductions, but subject to diminishing returns—by 2100 reaching $17 B under moderate mitigation, but only $7 B with stringent mitigation. Costs and benefits are sensitive to irreducible uncertainty about the fertilization effects of elevated atmospheric carbon dioxide, without which unabated warming incurs net costs of up to $18 B, generating benefits to moderate (stringent) mitigation as large as $26 B ($20 B).« less

US major crops’ uncertain climate change risks and greenhouse gas mitigation benefits

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

Wing, Ian Sue; Monier, Erwan; Stern, Ari

In this study, we estimate the costs of climate change to US agriculture, and associated potential benefits of abating greenhouse gas emissions. Five major crops' yield responses to climatic variation are modeled empirically, and the results combined with climate projections for a no-policy, high-warming future, as well as moderate and stringent mitigation scenarios. Unabated warming reduces yields of wheat and soybeans by 2050, and cotton by 2100, but moderate warming increases yields of all crops except wheat. Yield changes are monetized using the results of economic simulations within an integrated climate-economy modeling framework. Uncontrolled warming's economic effects on major cropsmore » are slightly positive—annual benefits <$4 B. These are amplified by emission reductions, but subject to diminishing returns—by 2100 reaching $17 B under moderate mitigation, but only $7 B with stringent mitigation. Costs and benefits are sensitive to irreducible uncertainty about the fertilization effects of elevated atmospheric carbon dioxide, without which unabated warming incurs net costs of up to $18 B, generating benefits to moderate (stringent) mitigation as large as $26 B ($20 B).« less

Waste-to-biomethane Concept Application: A Case Study of Valmiera City in Latvia

NASA Astrophysics Data System (ADS)

Barisa, Aiga; Dzene, Ilze; Rosa, Marika; Dobraja, Kristine

2015-12-01

The current needs of sustainable urban development are rising. As the transport sector expands, emissions continue to rise. Due to their negative impact on human health and the environment, air quality requirements are becoming more and more stringent. At the same time, the amount of waste is increasing. Europe Union policies attempt to relieve the pressure that these two stressors place on urban systems as they themselves expand. Today different solutions are available to decrease greenhouse gas emissions, increase air quality and improve waste management systems. Among them, waste-to-biomethane for use in urban systems deserves more attention. The paper focuses on application of the concept of waste-to-biomethane and the case study of Valmiera is evaluated. The results show that the application of the waste-to-biomethane strategy can contribute to a complete substitution of diesel fuel in urban buses and gives savings of around 1,000 tCO2/year. The price of the biomethane was found to be the most sensitive input factor. It is suggested that it should not exceed 0.40 EUR/Nm3 for a fuel conversion project of a fleet of 10 vehicles. Such a price can be ensured, if dry fermentation technology is chosen for biogas production. However, from the sustainability perspective, wet fermentation is more preferable due to the introduction of a source-separated organic waste management system in the region and higher gas yields. Introduction of this alternative requires additional funds which is a question of policy-level decisions.

A predictive analysis of CO2 emissions, environmental policy stringency, and economic growth in China.

PubMed

Ahmed, Khalid; Ahmed, Sidrah

2018-03-28

This study takes environmental policy stringency and economic activity as the controlling variables and forecasts the CO 2 emissions in China up to 2022. In doing so, an application of corrected grey model with convolution is used over the annual time series data between 1990 and 2012. The simulation results show that (1) between 2012 and 2022, CO 2 emissions in China is expected to increase at an average rate of 17.46% annually, raising the emissions intensity from 7.04 in 2012 to 25.461 metric tons per capita by 2022; (2) stringent environmental policies reduce CO 2 emissions-whereas, GDP tends to increase the emissions intensity in China; (3) stringent environmental policies are found to have a negative impact on GDP in China. Based on the empirical findings, the study also provides some policy suggestions to reduce emissions intensity in China.

Assessing and reducing fine and ultrafine particles inside Los Angeles taxis

NASA Astrophysics Data System (ADS)

Yu, Nu; Shu, Shi; Lin, Yan; Zhu, Yifang

2018-05-01

Taxi drivers and passengers are exposed to high levels of traffic-related air pollutants, but their exposures to fine (PM2.5) and ultrafine particles (UFPs) and related mitigation strategies are rarely explored. In this study, UFP and PM2.5 concentrations were monitored concurrently inside and outside of 22 taxis under different ventilation and mitigation conditions. Under realistic working conditions (no mitigation; NM), the average UFP and PM2.5 levels inside taxis were 1.46 × 104 particles/cm3 and 26 μg/m3, respectively. When the taxi ventilation was set to outside air mode and the windows kept closed, in-cabin UFP and PM2.5 concentrations are significantly associated with on-road concentrations, driving speed, and cabin air filter usage. The average in-cabin to on-roadway (I/O) ratios for UFP and PM2.5 were reduced from 0.60 to 0.75 under NM, to 0.47 and 0.52 under the most stringent mitigation strategy of keeping the windows closed and operating a high efficiency cabin air filter (WC + HECA). Among all tested taxi models, Toyota Prius exhibited the lowest UFP and PM2.5 I/O ratios under WC + HECA. Switching cabin air filters from the originally equipped manufacturer filter (OEM) to a HECA filter reduced the UFP and PM2.5 I/O ratios most effectively in Toyota Prius taxis as well.

Orphan Toxin OrtT (YdcX) of Escherichia coli Reduces Growth during the Stringent Response

DTIC Science & Technology

2015-01-29

antimicrobials trimethoprim and sulfamethoxazole; these antimicrobials induce the stringent response by inhibiting tetrahydrofolate synthesis...in the presence of both antimicrobials trimethoprim and sulfamethoxazole; these antimicrobials induce the stringent response by inhibiting...level [20]. Toxins 2015, 7 301 Despite these difficulties in determining physiological roles, TA systems are clearly phage inhibition systems

Assessment of the Air Quality Improvement Potentials for Seoul Metropolitan Area using GAINS-Korea

NASA Astrophysics Data System (ADS)

Kim, Y.; Woo, J. H.; Ahn, Y. H.; Kim, J.; Bu, C.; Lee, Y.; Choi, K. C.; Amann, M.; Kim, S. K.

2016-12-01

Urban areas are very important places for climate change and air pollution because they have been emitting a significant amount of Green House Gases (GHGs) and air pollutants. Cause they have massive pollutant emissions and high population density with amount of vehicles. Korea's government has set the 2nd phase capital air quality improvement program called Seoul metropolitan area Air Quality Management Plan(SAQMP), targeting the year 2024. The air quality improvement targets are to achieve annual mean PM10 and pm2.5concentration for SMA Area 30 ug/m3 and 20 ug/m3, respectively. To achieve this target, emissions of PM10, PM2.5 are required to be decreased up to 35%, 45%, respectively, from their future baseline level. In this study, we found the emission level of some pollutants for the year 2030 will be decreased compare with the baseline level but the concentration cannot meet their target even with more stringent control measures. The more in-depth analysis of future PM concentration, estimated from Source-Receptor(S-R) relationship, were conducted for more accurate air quality improvement assessment. As the result, we found that secondary and transboundary pollution have been plying significant role in Seoul Metro air quality. Not only direct/in-region measures, therefore, but indirect measures/international cooperation have to be conducted to achieve target air quality. ** This subject is supported by Korea Ministry of Environment as "Climate Change Correspondence Program". This work was supported by a grant from the National Institute of Environment Research (NIER), funded by the Ministry of Environment (MOE) of the Republic of Korea.

Building America Case Study: Evaluation of Ventilation Strategies in New Construction Multifamily Buildings, New York, New York (Fact Sheet)

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

Not Available

2014-09-01

In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the 'fresh' air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the 'normal leakage paths through the building envelope' disappear. CARB researchers have found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air tomore » apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. Product performance data are based on laboratory tests, and the assumption is that products will perform similarly in the field. Proper application involves matching expected performance at expected building pressures, but there is no guarantee that those conditions will exist consistently in the finished building. This research effort, which included several weeks of building pressure monitoring, sought to provide field validation of system performance. The performance of four substantially different strategies for providing make-up air to apartments was evaluated.« less

Evaluation of data thinning strategies for climate applications using the first four years of AIRS hyperspectral data

NASA Astrophysics Data System (ADS)

Aumann, Hartmut H.; Fishbein, Evan; Gohlke, Jan

2007-09-01

The application of infrared hyper-spectral sounder data to climate research requires the global analysis of multi-decadal time series of various atmosphere, surface or cloud related parameters. The data used in this analysis has to meet stringent global and scene independent absolute accuracy and stability requirements, it also has to be spatially and radiometrically unbiased, manageable in size and self-contained. Self-contained means that the data set contains not only a globally unbiased sample of the state of the Earth Climate system as seen in the infrared, it has to contain enough data to contrast clear with average (cloudy) data and to allow an independent assessment of the radiometric and spectral accuracy and stability of the data. We illustrate this with data from the Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounder Interferometer (IASI) data. AIRS and IASI were designed with fairly similar functional requirements. AIRS was launched on the EOS Aqua spacecraft in May 2002 into a 705 km polar sun-synchronous orbit with accurately maintained 1:30 PM ascending node. Essentially un-interrupted data are available since September 2002. Since October 2006 IASI is in a 9:30 AM polar orbit at 815 km altitude on the MetOp2 satellite, with data available since May 2007.

Chronic obstructive pulmonary diseases related to outdoor PM10, O3, SO2, and NO2 in a heavily polluted megacity of Iran.

PubMed

Khaniabadi, Yusef Omidi; Daryanoosh, Mohammad; Sicard, Pierre; Takdastan, Afshin; Hopke, Philip K; Esmaeili, Shirin; De Marco, Alessandra; Rashidi, Rajab

2018-04-18

This study was conducted to quantify, by an approach proposed by the World Health Organization (WHO), the daily hospital admissions for chronic obstructive pulmonary disease (COPD) related to exposure to particulate matter (PM 10 ) and oxidants such as ozone (O 3 ), sulfur dioxide (SO 2 ), and nitrogen dioxide (NO 2 ) in a heavily polluted city in Iran. For the health impact assessment, in terms of COPD, the current published relative risk (RR) and baseline incidence (BI) values, suggested by the WHO, and the 1-h O 3 concentrations and daily PM 10 , NO 2 , and SO 2 concentrations were compiled. The results showed that 5.9, 4.1, 1.2, and 1.9% of the COPD daily hospitalizations in 2011 and 6.6, 1.9, 2.3, and 2.1% in 2012 were attributed to PM 10 , O 3 , SO 2 , and NO 2 concentrations exceeding 10 μg/m 3 , respectively. This study indicates that air quality and the high air pollutant levels have an effect on COPD morbidity. Air pollution is associated with visits to emergency services and hospital admissions. A lower relative risk can be achieved if some stringent control strategies for reducing air pollutants or emission precursors are implemented.

[Mechanical Shimming Method and Implementation for Permanent Magnet of MRI System].

PubMed

Xue, Tingqiang; Chen, Jinjun

2015-03-01

A mechanical shimming method and device for permanent magnet of MRI system has been developed to meet its stringent homogeneity requirement without time-consuming passive shimming on site, installation and adjustment efficiency has been increased.

Dynamic Monitoring of Cleanroom Fallout Using an Air Particle Counter

NASA Technical Reports Server (NTRS)

Perry, Radford

2011-01-01

The particle fallout limitations and periodic allocations for the James Webb Space Telescope are very stringent. Standard prediction methods are complicated by non-linearity and monitoring methods that are insufficiently responsive. A method for dynamically predicting the particle fallout in a cleanroom using air particle counter data was determined by numerical correlation. This method provides a simple linear correlation to both time and air quality, which can be monitored in real time. The summation of effects provides the program better understanding of the cleanliness and assists in the planning of future activities. Definition of fallout rates within a cleanroom during assembly and integration of contamination-sensitive hardware, such as the James Webb Space Telescope, is essential for budgeting purposes. Balancing the activity levels for assembly and test with the particle accumulation rate is paramount. The current approach to predicting particle fallout in a cleanroom assumes a constant air quality based on the rated class of a cleanroom, with adjustments for projected work or exposure times. Actual cleanroom class can also depend on the number of personnel present and the type of activities. A linear correlation of air quality and normalized particle fallout was determined numerically. An air particle counter (standard cleanroom equipment) can be used to monitor the air quality on a real-time basis and determine the "class" of the cleanroom (per FED-STD-209 or ISO-14644). The correlation function provides an area coverage coefficient per class-hour of exposure. The prediction of particle accumulations provides scheduling inputs for activity levels and cleanroom class requirements.

Assessment of long-term and large-scale even-odd license plate controlled plan effects on urban air quality and its implication

NASA Astrophysics Data System (ADS)

Zhao, Suping; Yu, Ye; Qin, Dahe; Yin, Daiying; He, Jianjun

2017-12-01

To solve traffic congestion and to improve urban air quality, long-lasting and large-scale even-odd license plate controlled plan was implemented by local government during 20 November to 26 December 2016 in urban Lanzhou, a semi-arid valley city of northwest China. The traffic control measures provided an invaluable opportunity to evaluate its effects on urban air quality in less developed cities of northwest China. Based on measured simultaneously air pollutants and meteorological parameters, the abatement of traffic-related pollutants induced by the implemented control measures such as CO, PM2.5 and PM10 (the particulate matter with diameter less than 2.5 μm and 10 μm) concentrations were firstly quantified by comparing the air quality data in urban areas with those in rural areas (uncontrolled zones). The concentrations of CO, NO2 from motor vehicles and fine particulate matter (PM2.5) were shown to have significant decreases of 15%-23% during traffic control period from those measured before control period with hourly maximum CO, PM2.5, and NO2/SO2 reduction of 43%, 35% and 141.4%, respectively. The influence of the control measures on AQI (air quality index) and ozone was less as compared to its effect on other air pollutants. Therefore, to alleviate serious winter haze pollution in China and to protect human health, the stringent long-term and large-scale even-odd license plate controlled plan should be implemented aperiodically in urban areas, especially for the periods with poor diffusion conditions.

Multi-aircraft dynamics, navigation and operation

NASA Astrophysics Data System (ADS)

Houck, Sharon Wester

Air traffic control stands on the brink of a revolution. Fifty years from now, we will look back and marvel that we ever flew by radio beacons and radar alone, much as we now marvel that early aviation pioneers flew by chronometer and compass alone. The microprocessor, satellite navigation systems, and air-to-air data links are the technical keys to this revolution. Many airports are near or at capacity now for at least portions of the day, making it clear that major increases in airport capacity will be required in order to support the projected growth in air traffic. This can be accomplished by adding airports, adding runways at existing airports, or increasing the capacity of the existing runways. Technology that allows use of ultra closely spaced (750 ft to 2500 ft) parallel approaches would greatly reduce the environmental impact of airport capacity increases. This research tackles the problem of multi aircraft dynamics, navigation, and operation, specifically in the terminal area, and presents new findings on how ultra closely spaced parallel approaches may be accomplished. The underlying approach considers how multiple aircraft are flown in visual conditions, where spacing criteria is much less stringent, and then uses this data to study the critical parameters for collision avoidance during an ultra closely spaced parallel approach. Also included is experimental and analytical investigations on advanced guidance systems that are critical components of precision approaches. Together, these investigations form a novel approach to the design and analysis of parallel approaches for runways spaced less than 2500 ft apart. This research has concluded that it is technically feasible to reduce the required runway spacing during simultaneous instrument approaches to less than the current minimum of 3400 ft with the use of advanced navigation systems while maintaining the currently accepted levels of safety. On a smooth day with both pilots flying a tunnel-in-the-sky display and being guided by a Category I LAAS, it is technically feasible to reduce the runway spacing to 1100 ft. If a Category I LAAS and an "intelligent auto-pilot" that executes both the approach and emergency escape maneuver are used, the technically achievable required runway spacing is reduced to 750 ft. Both statements presume full aircraft state information, including position, velocity, and attitude, is being reliably passed between aircraft at a rate equal to or greater than one Hz.

Extractive sampling and optical remote sensing of F100 aircraft engine emissions.

PubMed

Cowen, Kenneth; Goodwin, Bradley; Joseph, Darrell; Tefend, Matthew; Satola, Jan; Kagann, Robert; Hashmonay, Ram; Spicer, Chester; Holdren, Michael; Mayfield, Howard

2009-05-01

The Strategic Environmental Research and Development Program (SERDP) has initiated several programs to develop and evaluate techniques to characterize emissions from military aircraft to meet increasingly stringent regulatory requirements. This paper describes the results of a recent field study using extractive and optical remote sensing (ORS) techniques to measure emissions from six F-15 fighter aircraft. Testing was performed between November 14 and 16, 2006 on the trim-pad facility at Tyndall Air Force Base in Panama City, FL. Measurements were made on eight different F100 engines, and the engines were tested on-wing of in-use aircraft. A total of 39 test runs were performed at engine power levels that ranged from idle to military power. The approach adopted for these tests involved extractive sampling with collocated ORS measurements at a distance of approximately 20-25 nozzle diameters downstream of the engine exit plane. The emission indices calculated for carbon dioxide, carbon monoxide, nitric oxide, and several volatile organic compounds showed very good agreement when comparing the extractive and ORS sampling methods.

Transient Thermal Analyses of Passive Systems on SCEPTOR X-57

NASA Technical Reports Server (NTRS)

Chin, Jeffrey C.; Schnulo, Sydney L.; Smith, Andrew D.

2017-01-01

As efficiency, emissions, and noise become increasingly prominent considerations in aircraft design, turning to an electric propulsion system is a desirable solution. Achieving the intended benefits of distributed electric propulsion (DEP) requires thermally demanding high power systems, presenting a different set of challenges compared to traditional aircraft propulsion. The embedded nature of these heat sources often preclude the use of traditional thermal management systems in order to maximize performance, with less opportunity to exhaust waste heat to the surrounding environment. This paper summarizes the thermal analyses of X-57 vehicle subsystems that don't employ externally air-cooled heat sinks. The high-power battery, wires, high-lift motors, and aircraft outer surface are subjected to heat loads with stringent thermal constraints. The temperature of these components are tracked transiently, since they never reach a steady-state equilibrium. Through analysis and testing, this report demonstrates that properly characterizing the material properties is key to accurately modeling peak temperature of these systems, with less concern for spatial thermal gradients. Experimentally validated results show the thermal profile of these systems can be sufficiently estimated using reduced order approximations.

Distributed decision support for the 21st century mission space

NASA Astrophysics Data System (ADS)

McQuay, William K.

2002-07-01

The past decade has produced significant changes in the conduct of military operations: increased humanitarian missions, asymmetric warfare, the reliance on coalitions and allies, stringent rules of engagement, concern about casualties, and the need for sustained air operations. Future mission commanders will need to assimilate a tremendous amount of information, make quick-response decisions, and quantify the effects of those decisions in the face of uncertainty. Integral to this process is creating situational assessment-understanding the mission space, simulation to analyze alternative futures, current capabilities, planning assessments, course-of-action assessments, and a common operational picture-keeping everyone on the same sheet of paper. Decision support tools in a distributed collaborative environment offer the capability of decomposing these complex multitask processes and distributing them over a dynamic set of execution assets. Decision support technologies can semi-automate activities, such as planning an operation, that have a reasonably well-defined process and provide machine-level interfaces to refine the myriad of information that is not currently fused. The marriage of information and simulation technologies provides the mission commander with a collaborative virtual environment for planning and decision support.

Distributed collaborative environments for predictive battlespace awareness

NASA Astrophysics Data System (ADS)

McQuay, William K.

2003-09-01

The past decade has produced significant changes in the conduct of military operations: asymmetric warfare, the reliance on dynamic coalitions, stringent rules of engagement, increased concern about collateral damage, and the need for sustained air operations. Mission commanders need to assimilate a tremendous amount of information, make quick-response decisions, and quantify the effects of those decisions in the face of uncertainty. Situational assessment is crucial in understanding the battlespace. Decision support tools in a distributed collaborative environment offer the capability of decomposing complex multitask processes and distributing them over a dynamic set of execution assets that include modeling, simulations, and analysis tools. Decision support technologies can semi-automate activities, such as analysis and planning, that have a reasonably well-defined process and provide machine-level interfaces to refine the myriad of information that the commander must fused. Collaborative environments provide the framework and integrate models, simulations, and domain specific decision support tools for the sharing and exchanging of data, information, knowledge, and actions. This paper describes ongoing AFRL research efforts in applying distributed collaborative environments to predictive battlespace awareness.

SOx removal by calcined MgAlFe hydrotalcite-like materials: effect of the chemical composition and the cerium incorporation method.

PubMed

Cantú, Manuel; López-Salinas, Esteban; Valente, Jaime S; Montiel, Ramon

2005-12-15

Sulfur oxides are one of the most hazardous atmospheric pollutants since they contribute directly to acid rain formation. Consequently, stringent environmental regulations limit atmospheric SOx emissions, motivating research on efficient ways to reduce them. To supply an alternative to reduce these emissions in fluid catalytic cracking units, this study discloses efficient SOx reducing materials based on calcined MgAlFe hydrotalcite-like compounds (HT's). Thus, HT materials were synthesized by several methods including cerium addition. The adsorption of SO2 was carried out by contacting the calcined solid with a mixture of SO2 (1%) in air at 650 degrees C. It was demonstrated that the isomorphic incorporation of iron increased its reduction capability which was reflected in higher reduction rates and metal sulfate reduction grade at 550 degrees C. Moreover, when cerium was present in the iron-containing materials the saturation rate was improved, because cerium oxide promotes the oxidation of SO2 to SO3. The way cerium is incorporated influences the SO2 adsorption capacity.

Short term association between ambient air pollution and mortality and modification by temperature in five Indian cities

NASA Astrophysics Data System (ADS)

Dholakia, Hem H.; Bhadra, Dhiman; Garg, Amit

2014-12-01

Indian cities are among the most polluted areas globally, yet assessments of short term mortality impacts due to pollution have been limited. Furthermore, studies examining temperature - pollution interactions on mortality are largely absent. Addressing this gap remains important in providing research evidence to better link health outcomes and air quality standards for India. Daily all-cause mortality, temperature, humidity and particulate matter less than 10 microns (PM10) data were collected for five cities - Ahmedabad, Bangalore, Hyderabad, Mumbai and Shimla spanning 2005-2012. Poisson regression models were developed to study short term impacts of PM10 as well as temperature - pollution interactions on daily all-cause mortality. We find that excess risk of mortality associated with a 10 μg/m3 PM10 increase is highest for Shimla (1.36%, 95% CI = -0.38%-3.1%) and the least for Ahmedabad (0.16%, 95% CI = -0.31%-0.62%). The corresponding values for Bangalore, Hyderabad and Mumbai are 0.22% (-0.04%-0.49%), 0.85% (0.06%-1.63%) and 0.2% (0.1%-0.3%) respectively. The relative health benefits of reducing pollution are higher for cleaner cities (Shimla) as opposed to dirtier cities (Mumbai). Overall we find that temperature and pollution interactions do not significantly impact mortality for the cities studied. This is one of the first multi-city studies that assess heterogeneity of air pollution impacts and possible modification due to temperature in Indian cities that are spread across climatic regions and topographies. Our findings highlight the need for pursuing stringent pollution control policies in Indian cities to minimize health impacts.

Development and fabrication of the Virginia skid-resistance measurement vehicle (model 2).

DOT National Transportation Integrated Search

1970-01-01

The inefficiency of the Virginia Highway Research Council, Model 1, skid measurement trailer, and the increasing effort expended by the American Society for Testing and Materials toward the development of more stringent specifications for pavement sk...

Design of Laser Based Monitoring Systems for Compliance Management of Odorous and Hazardous Air Pollutants in Selected Chemical Industrial Estates at Hyderabad, India

NASA Astrophysics Data System (ADS)

Sudhakar, P.; Kalavathi, P.; Ramakrishna Rao, D.; Satyanarayna, M.

2014-12-01

Industrialization can no longer sustain without internalization of the concerns of the receiving environment and land-use. Increased awareness and public pressure, coupled with regulatory instruments and bodies exert constant pressure on industries to control their emissions to a level acceptable to the receiving environment. However, when a group of industries come-up together as an industrial estate, the cumulative impacts of all the industries together often challenges the expected/desired quality of receiving environment, requiring stringent pollution control and monitoring measures. Laser remote sensing techniques provide powerful tools for environmental monitoring. These methods provide range resolved measurements of concentrations of various gaseous pollutants and suspended particulate matter (SPM) not only in the path of the beam but over the entire area. A three dimensional mapping of the pollutants and their dispersal can be estimated using the laser remote sensing methods on a continuous basis. Laser Radar (Lidar) systems are the measurements technology used in the laser remote sensing methods. Differential absorption lidar (DIAL) and Raman Lidar technologies have proved to be very useful for remote sensing of air pollutants. DIAL and Raman lidar systems can be applied for range resolved measurements of molecules like SO2, NO2, O3 Hg, CO, C2H4, H2O, CH4, hydrocarbons etc. in real time on a continuous basis. This paper describes the design details of the DAIL and Raman lidar techniques for measurement of various hazardous air pollutants which are being released into the atmosphere by the chemical industries operating in the Bachupally industrial Estate area at Hyderabad, India. The relative merits of the two techniques have been studied and the minimum concentration of pollutants that can be measured using these systems are presented. A dispersion model of the air pollutants in the selected chemical industrial estates at Hyderabad has been developed.

In-flight Evaluation of Aerodynamic Predictions of an Air-launched Space Booster

NASA Technical Reports Server (NTRS)

Curry, Robert E.; Mendenhall, Michael R.; Moulton, Bryan

1992-01-01

Several analytical aerodynamic design tools that were applied to the Pegasus (registered trademark) air-launched space booster were evaluated using flight measurements. The study was limited to existing codes and was conducted with limited computational resources. The flight instrumentation was constrained to have minimal impact on the primary Pegasus missions. Where appropriate, the flight measurements were compared with computational data. Aerodynamic performance and trim data from the first two flights were correlated with predictions. Local measurements in the wing and wing-body interference region were correlated with analytical data. This complex flow region includes the effect of aerothermal heating magnification caused by the presence of a corner vortex and interaction of the wing leading edge shock and fuselage boundary layer. The operation of the first two missions indicates that the aerodynamic design approach for Pegasus was adequate, and data show that acceptable margins were available. Additionally, the correlations provide insight into the capabilities of these analytical tools for more complex vehicles in which the design margins may be more stringent.

In-flight evaluation of aerodynamic predictions of an air-launched space booster

NASA Technical Reports Server (NTRS)

Curry, Robert E.; Mendenhall, Michael R.; Moulton, Bryan

1993-01-01

Several analytical aerodynamic design tools that were applied to the Pegasus air-launched space booster were evaluated using flight measurements. The study was limited to existing codes and was conducted with limited computational resources. The flight instrumentation was constrained to have minimal impact on the primary Pegasus missions. Where appropriate, the flight measurements were compared with computational data. Aerodynamic performance and trim data from the first two flights were correlated with predictions. Local measurements in the wing and wing-body interference region were correlated with analytical data. This complex flow region includes the effect of aerothermal heating magnification caused by the presence of a corner vortex and interaction of the wing leading edge shock and fuselage boundary layer. The operation of the first two missions indicates that the aerodynamic design approach for Pegasus was adequate, and data show that acceptable margins were available. Additionally, the correlations provide insight into the capabilities of these analytical tools for more complex vehicles in which design margins may be more stringent.

Fault tolerant computer control for a Maglev transportation system

NASA Technical Reports Server (NTRS)

Lala, Jaynarayan H.; Nagle, Gail A.; Anagnostopoulos, George

1994-01-01

Magnetically levitated (Maglev) vehicles operating on dedicated guideways at speeds of 500 km/hr are an emerging transportation alternative to short-haul air and high-speed rail. They have the potential to offer a service significantly more dependable than air and with less operating cost than both air and high-speed rail. Maglev transportation derives these benefits by using magnetic forces to suspend a vehicle 8 to 200 mm above the guideway. Magnetic forces are also used for propulsion and guidance. The combination of high speed, short headways, stringent ride quality requirements, and a distributed offboard propulsion system necessitates high levels of automation for the Maglev control and operation. Very high levels of safety and availability will be required for the Maglev control system. This paper describes the mission scenario, functional requirements, and dependability and performance requirements of the Maglev command, control, and communications system. A distributed hierarchical architecture consisting of vehicle on-board computers, wayside zone computers, a central computer facility, and communication links between these entities was synthesized to meet the functional and dependability requirements on the maglev. Two variations of the basic architecture are described: the Smart Vehicle Architecture (SVA) and the Zone Control Architecture (ZCA). Preliminary dependability modeling results are also presented.

Turbofan Engine Core Compartment Vent Aerodynamic Configuration Development Methodology

NASA Technical Reports Server (NTRS)

Hebert, Leonard J.

2006-01-01

This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment vent for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment vents exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment vents is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in vent exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.

Registering medicines for low-income countries: how suitable are the stringent review procedures of the World Health Organisation, the US Food and Drug Administration and the European Medicines Agency?

PubMed

Doua, Joachim Y; Van Geertruyden, Jean-Pierre

2014-01-01

New medicines are registered after a resource-demanding process. Unfortunately, in low-income countries (LICs), demand outweighs resources. To facilitate registration in LICs, stringent review procedures of the European Medicines Agency (EMA Article-58), Food and Drug Administration (FDA PEPFAR-linked review) and WHO Prequalification programme have been established. Only the PEPFAR-linked review gives approval, while the others make recommendations for approval. This study assessed the performance and discussed the challenges of these three stringent review procedures. Data from WHO, FDA, EMA, Medline and Internet were analysed. Over 60% of medicines reviewed by stringent review procedures are manufactured in India. Until 2012, WHO prequalified 400 medicines (211 vaccines, 130 antiretrovirals, 29 tuberculostatics, 15 antimalarials and 15 others). PEPFAR-linked review approved 156 antiretrovirals, while EMA Article 58 recommended approval of 3 antiretrovirals, 1 vaccine and 1 antimalarial. WHO Prequalification and PEPFAR-linked review are free of charge and as a result have accelerated access to antiretrovirals. They both built capacity in sub-Saharan Africa, although WHO prequalification relies technically on stringent regulatory authorities and financially on donors. Article-58 offers the largest disease coverage and strongest technical capacities, is costly and involves fewer LICs. To meet the high demand for quality medicines in LICs, these stringent review procedures need to enlarge their disease coverage. To improve registration, EMA Article 58 should actively involve LICs. Furthermore, LIC regulatory activities must not be fully resigned to stringent review procedure. © 2013 John Wiley & Sons Ltd.

Trapped strontium ion optical clock

NASA Astrophysics Data System (ADS)

Barwood, G. P.; Gill, P.; Klein, H. A.; Hosaka, K.; Huang, G.; Lea, S. N.; Margolis, H. S.; Szymaniec, K.; Walton, B. R.

2017-11-01

Increasingly stringent demands on atomic timekeeping, driven by applications such as global navigation satellite systems (GNSS), communications, and very-long baseline interferometry (VBLI) radio astronomy, have motivated the development of improved time and frequency standards. There are many scientific applications of such devices in space.

Characterization of Fine Particulate Matter and Associated Health Burden in Nanjing.

PubMed

Nie, Dongyang; Chen, Mindong; Wu, Yun; Ge, Xinlei; Hu, Jianlin; Zhang, Kai; Ge, Pengxiang

2018-03-27

Particulate matter (PM) air pollution has become a serious environmental problem in Nanjing and poses great health risks to local residents. In this study, characteristics of particulate matter with an aerodynamic diameter less than 2.5 μm (PM 2.5 ) over Nanjing were analyzed using hourly and daily averaged PM 2.5 concentrations and meteorological parameters collected from nine national monitoring sites during the period of March 2014 to February 2017. Then, the integrated exposure-response (IER) model was applied to assess premature mortality, years of life lost (YLL) attributable to PM 2.5 , and mortality benefits due to PM 2.5 reductions. The concentrations of PM 2.5 varied among hours, seasons and years, which can be explained by differences in emission sources, secondary formations and meteorological conditions. The decreased ratio of PM 2.5 to CO suggested that secondary contributions decreased while the relative contributions of vehicle exhaust increased from increased CO data. According to the values of attributable fractions (AF), stroke was the major cause of death, followed by ischemic heart disease (IHD), lung cancer (LC) and chronic obstructive pulmonary disease (COPD). The estimated total deaths in Nanjing due to PM 2.5 were 12,055 and 10,771, leading to 98,802 and 87,647 years of life lost in 2014 and 2015, respectively. The elderly and males had higher health risks than youngsters and females. When the PM 2.5 concentrations meet the World Health Organization (WHO) Air Quality Guidelines (AQG) of 10 μg/m³, 84% of the premature deaths would be avoided, indicating that the Nanjing government needs to adopt more stringent measure to reduce PM pollution and enhance the health benefits.

Characterization of Fine Particulate Matter and Associated Health Burden in Nanjing

PubMed Central

Nie, Dongyang; Chen, Mindong; Ge, Xinlei; Zhang, Kai; Ge, Pengxiang

2018-01-01

Particulate matter (PM) air pollution has become a serious environmental problem in Nanjing and poses great health risks to local residents. In this study, characteristics of particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) over Nanjing were analyzed using hourly and daily averaged PM2.5 concentrations and meteorological parameters collected from nine national monitoring sites during the period of March 2014 to February 2017. Then, the integrated exposure-response (IER) model was applied to assess premature mortality, years of life lost (YLL) attributable to PM2.5, and mortality benefits due to PM2.5 reductions. The concentrations of PM2.5 varied among hours, seasons and years, which can be explained by differences in emission sources, secondary formations and meteorological conditions. The decreased ratio of PM2.5 to CO suggested that secondary contributions decreased while the relative contributions of vehicle exhaust increased from increased CO data. According to the values of attributable fractions (AF), stroke was the major cause of death, followed by ischemic heart disease (IHD), lung cancer (LC) and chronic obstructive pulmonary disease (COPD). The estimated total deaths in Nanjing due to PM2.5 were 12,055 and 10,771, leading to 98,802 and 87,647 years of life lost in 2014 and 2015, respectively. The elderly and males had higher health risks than youngsters and females. When the PM2.5 concentrations meet the World Health Organization (WHO) Air Quality Guidelines (AQG) of 10 μg/m3, 84% of the premature deaths would be avoided, indicating that the Nanjing government needs to adopt more stringent measure to reduce PM pollution and enhance the health benefits. PMID:29584626

Realistic Radio Communications in Pilot Simulator Training

NASA Technical Reports Server (NTRS)

Burki-Cohen, Judith; Kendra, Andrew J.; Kanki, Barbara G.; Lee, Alfred T.

2000-01-01

Simulators used for total training and evaluation of airline pilots must satisfy stringent criteria in order to assure their adequacy for training and checking maneuvers. Air traffic control and company radio communications simulation, however, may still be left to role-play by the already taxed instructor/evaluators in spite of their central importance in every aspect of the flight environment. The underlying premise of this research is that providing a realistic radio communications environment would increase safety by enhancing pilot training and evaluation. This report summarizes the first-year efforts of assessing the requirement and feasibility of simulating radio communications automatically. A review of the training and crew resource/task management literature showed both practical and theoretical support for the need for realistic radio communications simulation. A survey of 29 instructor/evaluators from 14 airlines revealed that radio communications are mainly role-played by the instructor/evaluators. This increases instructor/evaluators' own workload while unrealistically lowering pilot communications load compared to actual operations, with a concomitant loss in training/evaluation effectiveness. A technology review searching for an automated means of providing radio communications to and from aircraft with minimal human effort showed that while promising, the technology is still immature. Further research and the need for establishing a proof-of-concept are also discussed.

Treated Wastewater Effluent as a Source of Microbial Pollution of Surface Water Resources

PubMed Central

Naidoo, Shalinee; Olaniran, Ademola O.

2013-01-01

Since 1990, more than 1.8 billion people have gained access to potable water and improved sanitation worldwide. Whilst this represents a vital step towards improving global health and well-being, accelerated population growth coupled with rapid urbanization has further strained existing water supplies. Whilst South Africa aims at spending 0.5% of its GDP on improving sanitation, additional factors such as hydrological variability and growing agricultural needs have further increased dependence on this finite resource. Increasing pressure on existing wastewater treatment plants has led to the discharge of inadequately treated effluent, reinforcing the need to improve and adopt more stringent methods for monitoring discharged effluent and surrounding water sources. This review provides an overview of the relative efficiencies of the different steps involved in wastewater treatment as well as the commonly detected microbial indicators with their associated health implications. In addition, it highlights the need to enforce more stringent measures to ensure compliance of treated effluent quality to the existing guidelines. PMID:24366046

The RpoB H481Y Rifampicin Resistance Mutation and an Active Stringent Response Reduce Virulence and Increase Resistance to Innate Immune Responses in Staphylococcus aureus

PubMed Central

Gao, Wei; Cameron, David R.; Davies, John K.; Kostoulias, Xenia; Stepnell, Justin; Tuck, Kellie L.; Yeaman, Michael R.; Peleg, Anton Y.; Stinear, Timothy P.; Howden, Benjamin P.

2013-01-01

The occurrence of mutations in methicillin-resistant Staphylococcus aureus (MRSA) during persistent infection leads to antimicrobial resistance but may also impact host-pathogen interactions. Here, we investigate the host-pathogen consequences of 2 mutations arising in clinical MRSA during persistent infection: RpoB H481Y, which is linked to rifampicin resistance, and RelA F128Y, which is associated with an active stringent response. Allelic exchange experiments showed that both mutations cause global transcriptional changes, leading to upregulation of capsule production, with attenuated virulence in a murine bacteremia model and reduced susceptibility to both antimicrobial peptides and whole-blood killing. Disruption of capsule biosynthesis reversed these impacts on innate immune function. These data clearly link MRSA persistence and reduced virulence to the same mechanisms that alter antimicrobial susceptibility. Our study highlights the wider consequences of suboptimal antimicrobial use, where drug resistance and immune escape mechanisms coevolve, thus increasing the likelihood of treatment failure. PMID:23255563

High-resolution sampling and analysis of ambient particulate matter in the Pearl River Delta region of southern China: source apportionment and health risk implications

NASA Astrophysics Data System (ADS)

Zhou, Shengzhen; Davy, Perry K.; Huang, Minjuan; Duan, Jingbo; Wang, Xuemei; Fan, Qi; Chang, Ming; Liu, Yiming; Chen, Weihua; Xie, Shanju; Ancelet, Travis; Trompetter, William J.

2018-02-01

Hazardous air pollutants, such as trace elements in particulate matter (PM), are known or highly suspected to cause detrimental effects on human health. To understand the sources and associated risks of PM to human health, hourly time-integrated major trace elements in size-segregated coarse (PM2.5-10) and fine (PM2.5) particulate matter were collected at the industrial city of Foshan in the Pearl River Delta region, China. Receptor modeling of the data set by positive matrix factorization (PMF) was used to identify six sources contributing to PM2.5 and PM10 concentrations at the site. Dominant sources included industrial coal combustion, secondary inorganic aerosol, motor vehicles and construction dust along with two intermittent sources (biomass combustion and marine aerosol). The biomass combustion source was found to be a significant contributor to peak PM2.5 episodes along with motor vehicles and industrial coal combustion. Conditional probability function (CPF) analysis was applied to estimate the source locations using the PMF-resolved source contribution coupled with the surface wind direction data. Health exposure risk of hazardous trace elements (Pb, As, Si, Cr, Mn and Ni) and source-specific values were estimated. The total hazard quotient (HQ) of PM2.5 was 2.09, higher than the acceptable limit (HQ = 1). The total carcinogenic risk (CR) was 3.37 × 10-3 for PM2.5, which was 3 times higher than the least stringent limit (1.0 × 10-4). Among the selected trace elements, As and Pb posed the highest non-carcinogenic and carcinogenic risks to human health, respectively. In addition, our results show that the industrial coal combustion source is the dominant non-carcinogenic and carcinogenic risk contributor, highlighting the need for stringent control of this source. This study provides new insight for policy makers to prioritize sources in air quality management and health risk reduction.

Tourists' attitudes towards ban on smoking in air-conditioned hotel lobbies in Thailand.

PubMed

Viriyachaiyo, V; Lim, A

2009-06-01

Thailand is internationally renowned for its stringent tobacco control measures. In Thailand, a regulation banning smoking in air-conditioned hotel lobbies was issued in late 2006, causing substantial apprehension within the hospitality industry. A survey of tourists' attitudes toward the ban was conducted. A cross-sectional survey of 5550 travellers staying in various hotels in Bangkok, Surat Thani, Phuket, Krabi and Songkhla provinces, October 2005 to December 2006. Travellers aged 15 years or older with a check-in duration of at least one day and willing to complete the questionnaire were requested by hotel staff to fill in the 5-minute questionnaire at check-in or later at their convenience. Secondhand cigarette smoke was recognised as harmful to health by 89.7% of respondents. 47.8% of travellers were aware of the Thai regulation banning smoking in air-conditioned restaurants. 80.9% of the respondents agreed with the ban, particularly female non-smokers. 38.6% of survey respondents indicated that they would be more likely to visit Thailand again because of the regulation, 53.4% that the regulation would not affect their decision and 7.9% that they would be less likely to visit Thailand again. Banning smoking in air-conditioned hotel lobbies in Thailand is widely supported by tourists. Enforcement of the regulation is more likely to attract tourists than dissuade them from holidaying in Thailand.

Tourists’ attitudes towards ban on smoking in air-conditioned hotel lobbies in Thailand

PubMed Central

Viriyachaiyo, V; Lim, A

2009-01-01

Background: Thailand is internationally renowned for its stringent tobacco control measures. In Thailand, a regulation banning smoking in air-conditioned hotel lobbies was issued in late 2006, causing substantial apprehension within the hospitality industry. A survey of tourists’ attitudes toward the ban was conducted. Methods: A cross-sectional survey of 5550 travellers staying in various hotels in Bangkok, Surat Thani, Phuket, Krabi and Songkhla provinces, October 2005 to December 2006. Travellers aged 15 years or older with a check-in duration of at least one day and willing to complete the questionnaire were requested by hotel staff to fill in the 5-minute questionnaire at check-in or later at their convenience. Results: Secondhand cigarette smoke was recognised as harmful to health by 89.7% of respondents. 47.8% of travellers were aware of the Thai regulation banning smoking in air-conditioned restaurants. 80.9% of the respondents agreed with the ban, particularly female non-smokers. 38.6% of survey respondents indicated that they would be more likely to visit Thailand again because of the regulation, 53.4% that the regulation would not affect their decision and 7.9% that they would be less likely to visit Thailand again. Conclusion: Banning smoking in air-conditioned hotel lobbies in Thailand is widely supported by tourists. Enforcement of the regulation is more likely to attract tourists than dissuade them from holidaying in Thailand. PMID:19364754

A rapid response air quality analysis system for use in projects having stringent quality assurance requirements

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

Bowman, A.W.

1990-04-01

This paper describes an approach to solve air quality problems which frequently occur during iterations of the baseline change process. From a schedule standpoint, it is desirable to perform this evaluation in as short a time as possible while budgetary pressures limit the size of the staff available to do the work. Without a method in place to deal with baseline change proposal requests the environment analysts may not be able to produce the analysis results in the time frame expected. Using a concept called the Rapid Response Air Quality Analysis System (RAAS), the problems of timing and cost becomemore » tractable. The system could be adapted to assess other atmospheric pathway impacts, e.g., acoustics or visibility. The air quality analysis system used to perform the EA analysis (EA) for the Salt Repository Project (part of the Civilian Radioactive Waste Management Program), and later to evaluate the consequences of proposed baseline changes, consists of three components: Emission source data files; Emission rates contained in spreadsheets; Impact assessment model codes. The spreadsheets contain user-written codes (macros) that calculate emission rates from (1) emission source data (e.g., numbers and locations of sources, detailed operating schedules, and source specifications including horsepower, load factor, and duty cycle); (2) emission factors such as those published by the U.S. Environmental Protection Agency, and (3) control efficiencies.« less

Piloted simulator study of allowable time delay in pitch flight control system of a transport airplane with negative static stability

NASA Technical Reports Server (NTRS)

Grantham, William D.; Smith, Paul M.; Person, Lee H., Jr.; Meyer, Robert T.; Tingas, Stephen A.

1987-01-01

A piloted simulation study was conducted to determine the permissible time delay in the flight control system of a 10-percent statically unstable transport airplane during cruise flight conditions. The math model used for the simulation was a derivative Lockheed L-1011 wide-body jet transport. Data were collected and analyzed from a total of 137 cruising flights in both calm- and turbulent-air conditions. Results of this piloted simulation study verify previous findings that show present military specifications for allowable control-system time delay may be too stringent when applied to transport-size airplanes. Also, the degree of handling-qualities degradation due to time delay is shown to be strongly dependent on the source of the time delay in an advanced flight control system. Maximum allowable time delay for each source of time delay in the control system, in addition to a less stringent overall maximum level of time delay, should be considered for large aircraft. Preliminary results also suggest that adverse effects of control-system time delay may be at least partially offset by variations in control gearing. It is recommended that the data base include different airplane baselines, control systems, and piloting tasks with many pilots participating, so that a reasonable set of limits for control-system time delay can be established to replace the military specification limits currently being used.

Transplanting Sensitized Kidney Transplant Patients With Equivalent Outcomes Utilizing Stringent HLA Crossmatching.

PubMed

Rohan, Vinayak S; Taber, David J; Moussa, Omar; Pilch, Nicole A; Denmark, Signe; Meadows, Holly B; McGillicuddy, John W; Chavin, Kenneth D; Baliga, Prabhakar K; Bratton, Charles F

2017-02-01

Elevated panel reactive antibody levels have been traditionally associated with increased acute rejection rate and decreased long-term graft survival after kidney transplant. In this study, our objective was to determine patient and allograft outcomes in sensitized kidney transplant recipients with advanced HLA antibody detection and stringent protein sequence epitope analyses. This was a subanalysis of a prospective, risk-stratified randomized controlled trial that compared interleukin 2 receptor antagonist to rabbit antithymocyte globulin induction in 200 kidney transplant recipients, examining outcomes based on panel reactive antibody levels of < 20% (low) versus ≥ 20% (high, sensitized). The study was conducted between February 2009 and July 2011. All patients underwent solid-phase single antigen bead assays to detect HLA antibodies and stringent HLA epitope analyses with protein sequence alignment for virtual crossmatching. Delayed graft function, acute rejection rates, and graft loss were the main outcomes measured. Both the low (134 patients) and high (66 patients) panel reactive antibody level cohorts had equivalent induction and maintenance immunosuppression. Patients in the high-level group were more likely to be female (P < .001), African American (P < .001), and received a kidney from a deceased donor (P = .004). Acute rejection rates were similar between the low (rate of 8%) and high (rate of 9%) panel reactive antibody groups (P = .783). Delayed graft function, borderline rejection, graft loss, and death were not different between groups. Multivariate analyses demonstrated delayed graft function to be the strongest predictor of acute rejection (odds ratio, 5.7; P = .005); panel reactive antibody level, as a continuous variable, had no significant correlation with acute rejection (C statistic, 0.48; P = .771). Appropriate biologic matching with single antigen bead assays and stringent epitope analyses provided excellent outcomes in sensitized patients regardless of the induction therapy choice.

Lubricity of biobased diesel fuels and additives

USDA-ARS?s Scientific Manuscript database

Modern diesel engines rely on the fuel itself to lubricate moving parts in the fuel and engine systems. Prior to the late 1990s, diesel fuel from petroleum provided sufficient lubricity to effectively reduce wear in injectors and fuel pumps. Increasingly stringent limitations on the sulfur content o...

Using Common Planning Time to Foster Professional Learning

ERIC Educational Resources Information Center

Dever, Robin; Lash, Martha J.

2013-01-01

Increased emphasis on meeting state standards, more stringent requirements for designation as highly qualified, and intensified accountability for student performance have foisted new expectations upon teachers and stimulated changes in professional development models in which the greater urgency is clearly to attend to the teacher's role as…

Accuracy of Surgery Clerkship Performance Raters.

ERIC Educational Resources Information Center

Littlefield, John H.; And Others

1991-01-01

Interrater reliability in numerical ratings of clerkship performance (n=1,482 students) in five surgery programs was studied. Raters were classified as accurate or moderately or significantly stringent or lenient. Results indicate that increasing the proportion of accurate raters would substantially improve the precision of class rankings. (MSE)

The impact of multiple show-ups on eyewitness decision-making and innocence risk.

PubMed

Smith, Andrew M; Bertrand, Michelle; Lindsay, R C L; Kalmet, Natalie; Grossman, Deborah; Provenzano, Daniel

2014-09-01

If an eyewitness rejects a show-up, police may respond by finding a new suspect and conducting a second show-up with the same eyewitness. Police may continue finding suspects and conducting show-ups until the eyewitness makes an identification (Study 1). Relatively low criterion-setting eyewitnesses filter themselves out of the multiple show-ups procedure by choosing the first suspect with whom they are presented (Studies 2 and 3). Accordingly, response bias was more stringent on the second show-up when compared with the first, but became no more stringent with additional show-ups. Despite this stringent shift in response bias, innocence risk increased with additional show-ups, as false alarms cumulate (Studies 2 and 3). Although unbiased show-up instructions decreased innocent suspect identifications, the numbers were still discouraging (Study 4). Given the high number of innocent suspects who would be mistakenly identified through the use of multiple show-up procedures, using such identifications as evidence of guilt is questionable. Although evidence of guilt is limited to identifications from a single show-up, practical constraints might sometimes require police to use additional show-ups. Accordingly, we propose a stronger partition between evidentiary and investigative procedures. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Information Control: Preventing a Vietnamese Spring?

DTIC Science & Technology

2013-11-01

challenges with labor market tensions and land management corruption continue to plague the Party and demonstrate their inability to effectively...the 1997 regulation in 2001. The 2001 regulation provided for a “partial liberalisation of the internet market ” while placing a “more stringent...Vietnam increased. This increase resulted in market competition and lower prices for internet service, broadening the availability of the internet to

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

Plural Societies and the Possibility of Shared Citizenship

ERIC Educational Resources Information Center

Merry, Michael S.

2012-01-01

As civilization pushes headlong into the twenty-first century, increasingly stringent demands for citizenship issue forth from governments around the world faced with a formidable assortment of challenges. Faced with these challenges, states are exploring ways to elicit civic attachments from their heterogeneous populations, but doing so is…

Opportunities for improving risk communication during the permitting process for entomophagous biological control agents: A review of current systems

USDA-ARS?s Scientific Manuscript database

Concerns about potentially irreversible non-target impacts from the importation and release of entomophagous biological control agents (BCAs) have resulted in increasingly stringent import requirements by National Plant Protection Organizations. Despite numerous scientific publications on the poten...

Television, Censorship and South Africa.

ERIC Educational Resources Information Center

Giffard, C. Anthony; Cohen, Lisa

Network television news has often been accused of inciting and prolonging incidents of public violence, whether riots or terrorism, and in South Africa this type of thinking has led to increasingly stringent restrictions on both domestic and foreign media covering the violent unrest there. A study determined a chronology of events and analyzed the…

Enantioselective toxicity and bioaccumulation of fipronil in fathead minnows (Pimephales promelas) following water and sediment exposures

EPA Science Inventory

Fipronil is a widely used, broad-spectrum pesticide that is applied as an equal mixture of two enantiomers. As regulations on older pesticides become more stringent, production and application of fipronil is expected to grow, leading to increased inputs into aquatic environments ...

Circuitry Linking the Csr and Stringent Response Global Regulatory Systems

PubMed Central

Edwards, Adrianne N.; Patterson-Fortin, Laura M.; Vakulskas, Christopher A.; Mercante, Jeffrey W.; Potrykus, Katarzyna; Vinella, Daniel; Camacho, Martha I.; Fields, Joshua A.; Thompson, Stuart A.; Georgellis, Dimitris; Cashel, Michael; Babitzke, Paul; Romeo, Tony

2011-01-01

Summary CsrA protein regulates important cellular processes by binding to target mRNAs and altering their translation and/or stability. In Escherichia coli, CsrA binds to sRNAs, CsrB and CsrC, which sequester CsrA and antagonize its activity. Here, mRNAs for relA, spoT and dksA of the stringent response system were found among 721 different transcripts that copurified with CsrA. Many of the transcripts that copurified with CsrA were previously determined to respond to ppGpp and/or DksA. We examined multiple regulatory interactions between the Csr and stringent response systems. Most importantly, DksA and ppGpp robustly activated csrB/C transcription (10-fold), while they modestly activated csrA expression. We propose that CsrA-mediated regulation is relieved during the stringent response. Gel shift assays confirmed high affinity binding of CsrA to relA mRNA leader and weaker interactions with dksA and spoT. Reporter fusions, qRT-PCR, and immunoblotting showed that CsrA repressed relA expression, and (p)ppGpp accumulation during stringent response was enhanced in a csrA mutant. CsrA had modest to negligible effects on dksA and spoT expression. Transcription of dksA was negatively autoregulated via a feedback loop that tended to mask CsrA effects. We propose that the Csr system fine-tunes the stringent response and discuss biological implications of the composite circuitry. PMID:21488981

Stringent DDI-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions.

PubMed

Zhou, Hufeng; Rezaei, Javad; Hugo, Willy; Gao, Shangzhi; Jin, Jingjing; Fan, Mengyuan; Yong, Chern-Han; Wozniak, Michal; Wong, Limsoon

2013-01-01

H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are very important information to illuminate the infection mechanism of M. tuberculosis H37Rv. But current H. sapiens-M. tuberculosis H37Rv PPI data are very scarce. This seriously limits the study of the interaction between this important pathogen and its host H. sapiens. Computational prediction of H. sapiens-M. tuberculosis H37Rv PPIs is an important strategy to fill in the gap. Domain-domain interaction (DDI) based prediction is one of the frequently used computational approaches in predicting both intra-species and inter-species PPIs. However, the performance of DDI-based host-pathogen PPI prediction has been rather limited. We develop a stringent DDI-based prediction approach with emphasis on (i) differences between the specific domain sequences on annotated regions of proteins under the same domain ID and (ii) calculation of the interaction strength of predicted PPIs based on the interacting residues in their interaction interfaces. We compare our stringent DDI-based approach to a conventional DDI-based approach for predicting PPIs based on gold standard intra-species PPIs and coherent informative Gene Ontology terms assessment. The assessment results show that our stringent DDI-based approach achieves much better performance in predicting PPIs than the conventional approach. Using our stringent DDI-based approach, we have predicted a small set of reliable H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. We also analyze the H. sapiens-M. tuberculosis H37Rv PPIs predicted by our stringent DDI-based approach using cellular compartment distribution analysis, functional category enrichment analysis and pathway enrichment analysis. The analyses support the validity of our prediction result. Also, based on an analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent DDI-based approach, we have discovered some important properties of domains involved in host-pathogen PPIs. We find that both host and pathogen proteins involved in host-pathogen PPIs tend to have more domains than proteins involved in intra-species PPIs, and these domains have more interaction partners than domains on proteins involved in intra-species PPI. The stringent DDI-based prediction approach reported in this work provides a stringent strategy for predicting host-pathogen PPIs. It also performs better than a conventional DDI-based approach in predicting PPIs. We have predicted a small set of accurate H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies.

A Powerful New Engine

NASA Technical Reports Server (NTRS)

2001-01-01

Through Small Business Innovation Research (SBIR) funding from NASA's Glenn Research Center, Moller International created a new coating for rotary engines, which significantly improves the fuel consumption of a vehicle while reducing emissions. The new coatings are offered in the new Rotapower(R) engine, which is produced and distributed by Moller subsidiary, Freedom Motors, Inc. The coating allows the Rotapower engine to function smoother than other models, reducing wear and protecting the engine. The Rotapower engine has the ability to operate on a variety of fuels, including gasoline, natural gas, diesel, alcohol, and kerosene. A small and lightweight engine, it is projected to replace many of today's bulkier versions. The 10 horsepower model fits in the palm of one's hand, while the 160 horsepower model fits into a 5-gallon bucket. The clean running Rotapower engine is environmentally appealing, because it eliminates over 98 percent of the total emissions given off by traditional piston engines. Fewer pollutants are spewed into the air, making it especially attractive in areas where air pollution is a major problem. Due to the clean-burning nature of the engine, it meets the stringent standards set by the California Air Resources Board. The engine also has numerous commercial benefits in several types of recreational, industrial, and transportation applications, including personal watercraft, snowmobiles, portable generators. and pumps.

A new unsteady mixing model to predict NO(x) production during rapid mixing in a dual-stage combustor

NASA Technical Reports Server (NTRS)

Menon, Suresh

1992-01-01

An advanced gas turbine engine to power supersonic transport aircraft is currently under study. In addition to high combustion efficiency requirements, environmental concerns have placed stringent restrictions on the pollutant emissions from these engines. A combustor design with the potential for minimizing pollutants such as NO(x) emissions is undergoing experimental evaluation. A major technical issue in the design of this combustor is how to rapidly mix the hot, fuel-rich primary zone product with the secondary diluent air to obtain a fuel-lean mixture for combustion in the second stage. Numerical predictions using steady-state methods cannot account for the unsteady phenomena in the mixing region. Therefore, to evaluate the effect of unsteady mixing and combustion processes, a novel unsteady mixing model is demonstrated here. This model has been used to study multispecies mixing as well as propane-air and hydrogen-air jet nonpremixed flames, and has been used to predict NO(x) production in the mixing region. Comparison with available experimental data show good agreement, thereby providing validation of the mixing model. With this demonstration, this mixing model is ready to be implemented in conjunction with steady-state prediction methods and provide an improved engineering design analysis tool.

Dummy and injury criteria for aircraft crashworthiness.

DOT National Transportation Integrated Search

1996-04-01

Since 1988, newly type-certificated aircraft are required to comply with stringent crashworthiness requirements. Central to these more stringent requirements is a dynamic test that assesses the potential for injury for someone exposed to similar cond...

Emissions Benefits From Renewable Fuels and Other Alternatives for Heavy-Duty Vehicles

NASA Astrophysics Data System (ADS)

Hajbabaei, Maryam

There is a global effort to expand the use of alternative fuels due to their several benefits such as improving air quality with reducing some criteria emissions, reducing dependency on fossil fuels, and reducing greenhouse gases such as carbon dioxide. This dissertation is focused on investigating the impact of two popular alternative fuels, biodiesel and natural gas (NG), on emissions from heavy-duty engines. Biodiesel is one of the most popular renewable fuels with diesel applications. Although biodiesel blends are reported to reduce particulate matter, carbon monoxide, and total hydrocarbon emissions; there is uncertainty on their impact on nitrogen oxides (NOx) emissions. This dissertation evaluated the effect of biodiesel feedstock, biodiesel blend level, engine technology, and driving conditions on NOx emissions. The results showed that NOx emissions increase with 20% and higher biodiesel blends. Also, in this study some strategies were proposed and some fuel formulations were found for mitigating NOx emissions increases with biodiesel. The impact of 5% biodiesel on criteria emissions specifically NOx was also fully studied in this thesis. As a part of the results of this study, 5% animal-based biodiesel was certified for use in California based on California Air Resources Board emissions equivalent procedure. NG is one of the most prominent alternative fuels with larger reserves compared to crude oil. However, the quality of NG depends on both its source and the degree to which it is processed. The current study explored the impact of various NG fuels, ranging from low methane/high energy gases to high methane/low energy gases, on criteria and toxic emissions from NG engines with different combustion and aftertreatment technologies. The results showed stronger fuel effects for the lean-burn technology bus. Finally, this thesis investigated the impact of changing diesel fuel composition on the criteria emissions from a variety of heavy-duty engine technologies. Emissions from an average diesel fuel used throughout the U.S. were compared with a 10% aromatic, ultra-low sulfur diesel fuel used in California with more stringent air quality regulations. The results showed that the emerging aftertreatment technologies eventually eliminate the benefits of the lower aromatic content/higher cetane number diesel fuels.

Design and CFD analysis of intake port and exhaust port for a 4 valve cylinder head engine

NASA Astrophysics Data System (ADS)

Latheesh, V. M.; Parthasarathy, P.; Baskaran, V.; Karthikeyan, S.

2018-02-01

In cylinder air motion in a compression ignition engine effects mixing of air-fuel, quality of combustion and emission produced. The primary objective is to design and analyze intake and the exhaust port for a four valve cylinder head to meet higher emission norms for a given diesel engine with two valves. In this work, an existing cylinder head designed for two valves was redesigned with 4 valves. The modern trend also confirms this approach. This is being followed in the design and development of new generation engines to meet the stringent environment norms, competition in market and demand for more fuel-efficient engines. The swirl ratio and flow coefficient were measured for different valve lifts using STAR CCM+. CFD results were validated with the two-valve cylinder experimental results. After validation, a comparison between two-valve and four-valve cylinder head was done. The conversion of two valve cylinder head to 4 valves may not support modern high swirl generating port layout and requires a trade-off between many design parameters.

Brownfields and health risks--air dispersion modeling and health risk assessment at landfill redevelopment sites.

PubMed

Ofungwu, Joseph; Eget, Steven

2006-07-01

Redevelopment of landfill sites in the New Jersey-New York metropolitan area for recreational (golf courses), commercial, and even residential purposes seems to be gaining acceptance among municipal planners and developers. Landfill gas generation, which includes methane and potentially toxic nonmethane compounds usually continues long after closure of the landfill exercise phase. It is therefore prudent to evaluate potential health risks associated with exposure to gas emissions before redevelopment of the landfill sites as recreational, commercial, and, especially, residential properties. Unacceptably high health risks would call for risk management measures such as limiting the development to commercial/recreational rather than residential uses, stringent gas control mechanisms, interior air filtration, etc. A methodology is presented for applying existing models to estimate residual landfill hazardous compounds emissions and to quantify associated health risks. Besides the toxic gas constituents of landfill emissions, other risk-related issues concerning buried waste, landfill leachate, and explosive gases were qualitatively evaluated. Five contiguously located landfill sites in New Jersey intended for residential and recreational redevelopment were used to exemplify the approach.

Production, distribution, and cost of oxygenated gasoline blends as a CO control strategy

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

Holmes, J.G; Dworsky, B.S.

1988-01-01

During the past two decades, efforts to reduce the contribution of automotive emissions to air pollution have focused principally on the development of more stringent emission standards for new vehicles, and the use of inspection and maintenance (I/M) programs. Despite the achievements in the last few years, motor vehicles have remained a major source of air pollution in urban areas. Further reductions in either the emission standards or in I/M program pass/fail cutpoints are not politically feasible, and alternative methods to achieve emission reductions are being investigated. One potential method is through the use of alternative fuels that can reducemore » tailpipe emissions. For example, the addition of alcohol or ether into gasoline has been shown to lean out the engine and cut carbon monoxide emissions. This paper compares the costs of producing and distribution methanol, ethanol, and MTBE blends as part of a carbon monoxide control strategy. It addresses the costs of production, distribution, infrastructure development, and retailing associated with each fuel blend.« less

Measured and Modeled Hydroxyl (OH) and Hydroperoxyl (HO2) During KORUS-AQ

NASA Astrophysics Data System (ADS)

Brosius, A. L.; Brune, W. H.; Thames, A. B.; Miller, D. O.

2017-12-01

In the troposphere, hydroxyl (OH) reacts with most atmospheric pollutants, initiating their removal from the atmosphere and in some cases creating other atmospheric pollutants, such as ozone and small particles. Hydroperoxyl (HO2) also plays a role in oxidation chemistry by producing tropospheric ozone (O3). Air pollution in Korea is a combination of locally generated pollution, aged pollution from China, and the interaction of local pollution with forest emissions. Thus, OH and HO2 interact with a complex soup of chemical species over Korea, providing a stringent test for the understanding of atmospheric oxidation chemistry. During KORUS-AQ, we measured OH and HO2 using the Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) as part of a large instrument suite installed on the NASA DC-8 aircraft. We use the Master Chemical Mechanism (MCM), constrained by the simultaneous measurement of many of chemical species to calculate OH and HO2. While the measured and modeled OH and HO2 generally agree within combined uncertainties, there are substantial discrepancies. We will discuss possible reasons for the discrepancies and the implications for air quality regulatory policy.

Recent Contributions of Air- and Biomarkers to the Control of Secondhand Smoke (SHS): A Review

PubMed Central

Prignot, Jacques J.

2011-01-01

Since the publication of the US Surgeon General Reports in 1996 and 2006 and the report of the California Environmental Protection Agency in 1999, many reports have appeared on the contribution of air and biomarkers to different facets of the secondhand smoke (SHS) issue, which are the targets of this review. These recent studies have allowed earlier epidemiological surveys to be biologically validated, and their plausibility demonstrated, quantified the levels of exposure to SHS before the bans in various environments, showed the deficiencies of mechanical control methods and of partial bans and the frequently correct implementation of the efficient total bans. More stringent regulation remains necessary in the public domain (workplaces, hospitality venues, transport sector, etc.) in many countries. Personal voluntary protection efforts against SHS are also needed in the private domain (homes, private cars). The effects of SHS on the cardiovascular, respiratory and neuropsychic systems, on pregnancy and fertility, on cancers and on SHS genotoxicity are confirmed through experimental human studies and through the relationship between markers and prevalence of disease or of markers of disease risk. PMID:21556172

Cyber Safety and Security for Reduced Crew Operations (RCO)

NASA Technical Reports Server (NTRS)

Driscoll, Kevin R.; Roy, Aloke; Ponchak, Denise S.; Downey, Alan N.

2017-01-01

NASA and the Aviation Industry is looking into reduced crew operations (RCO) that would cut today's required two-person flight crews down to a single pilot with support from ground-based crews. Shared responsibility across air and ground personnel will require highly reliable and secure data communication and supporting automation, which will be safety-critical for passenger and cargo aircraft. This paper looks at the different types and degrees of authority delegation given from the air to the ground and the ramifications of each, including the safety and security hazards introduced, the mitigation mechanisms for these hazards, and other demands on an RCO system architecture which would be highly invasive into (almost) all safety-critical avionics. The adjacent fields of unmanned aerial systems and autonomous ground vehicles are viewed to find problems that RCO may face and related aviation accident scenarios are described. The paper explores possible data communication architectures to meet stringent performance and information security (INFOSEC) requirements of RCO. Subsequently, potential challenges for RCO data communication authentication, encryption and non-repudiation are identified.

Applications of Probabilistic Combiners on Linear Feedback Shift Register Sequences

DTIC Science & Technology

2016-12-01

on the resulting output strings show a drastic increase in complexity, while simultaneously passing the stringent randomness tests required by the...a three-variable function. Our tests on the resulting output strings show a drastic increase in complex- ity, while simultaneously passing the...10001101 01000010 11101001 Decryption of a message that has been encrypted using bitwise XOR is quite simple. Since each bit is its own additive inverse

Circuitry linking the Csr and stringent response global regulatory systems.

PubMed

Edwards, Adrianne N; Patterson-Fortin, Laura M; Vakulskas, Christopher A; Mercante, Jeffrey W; Potrykus, Katarzyna; Vinella, Daniel; Camacho, Martha I; Fields, Joshua A; Thompson, Stuart A; Georgellis, Dimitris; Cashel, Michael; Babitzke, Paul; Romeo, Tony

2011-06-01

CsrA protein regulates important cellular processes by binding to target mRNAs and altering their translation and/or stability. In Escherichia coli, CsrA binds to sRNAs, CsrB and CsrC, which sequester CsrA and antagonize its activity. Here, mRNAs for relA, spoT and dksA of the stringent response system were found among 721 different transcripts that copurified with CsrA. Many of the transcripts that copurified with CsrA were previously determined to respond to ppGpp and/or DksA. We examined multiple regulatory interactions between the Csr and stringent response systems. Most importantly, DksA and ppGpp robustly activated csrB/C transcription (10-fold), while they modestly activated csrA expression. We propose that CsrA-mediated regulation is relieved during the stringent response. Gel shift assays confirmed high affinity binding of CsrA to relA mRNA leader and weaker interactions with dksA and spoT. Reporter fusions, qRT-PCR and immunoblotting showed that CsrA repressed relA expression, and (p)ppGpp accumulation during stringent response was enhanced in a csrA mutant. CsrA had modest to negligible effects on dksA and spoT expression. Transcription of dksA was negatively autoregulated via a feedback loop that tended to mask CsrA effects. We propose that the Csr system fine-tunes the stringent response and discuss biological implications of the composite circuitry. © Published 2011. This article is a US Government work and is in the public domain in the USA.

Petrol and diesel exhaust particles accelerate the horizontal transfer of plasmid-mediated antimicrobial resistance genes.

PubMed

Zhang, Ye; Gu, April Z; Cen, Tianyu; Li, Xiangyang; Li, Dan; Chen, Jianmin

2018-05-01

Particles exhausted from petrol and diesel consumptions are major components of urban air pollution that can be exposed to human via direct inhalation or other routes due to atmospheric deposition into water and soil. Antimicrobial resistance is one of the most serious threats to modern health care. However, how the petrol and diesel exhaust particles affect the development and spread of antimicrobial resistance genes (ARGs) in various environments remain largely unknown. This study investigated the effects and potential mechanisms of four representative petrol and diesel exhaust particles, namely 97 octane petrol, 93 octane petrol, light diesel oil, and marine heavy diesel oil, on the horizontal transfer of ARGs between two opportunistic Escherichia coli (E. coli) strains, E. coli S17-1 (donor) and E. coli K12 (recipient). The results demonstrated that these four representative types of nano-scale particles induced concentration-dependent increases in conjugative transfer rates compared with the controls. The underlying mechanisms involved in the accelerated transfer of ARGs were also identified, including the generation of intracellular reactive oxygen species (ROS) and the consequent induction of oxidative stress, SOS response, changes in cell morphology, and the altered mRNA expression of membrane protein genes and those involved in the promotion of conjugative transfer. The findings provide new evidences and mechanistic insights into the antimicrobial resistance risks posed by petrol and diesel exhaust particles, and highlight the implications and need for stringent strategies on alternative fuels to mitigate air pollution and health risks. Copyright © 2018 Elsevier Ltd. All rights reserved.

Economic analysis of atmospheric mercury emission control for coal-fired power plants in China.

PubMed

Ancora, Maria Pia; Zhang, Lei; Wang, Shuxiao; Schreifels, Jeremy; Hao, Jiming

2015-07-01

Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF+WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. Copyright © 2015. Published by Elsevier B.V.

An analysis of historical exposures of pressmen to airborne benzene (1938-2006).

PubMed

Novick, Rachel M; Keenan, James J; Gross, Sherilyn A; Paustenbach, Dennis J

2013-07-01

Benzene is an aromatic hydrocarbon that, with sufficient cumulative lifetime doses, can cause acute myelogenous leukemia. Because of its volatility and solvent properties, it was used in the printing industry in inks, ink solvents, and cleaning agents from the 1930s to the 1970s. This analysis represents the first known attempt to gather and synthesize the available data on historical airborne benzene concentrations in printing facilities and exposures to pressmen. The sources of fugitive benzene vapors from printing operations have been identified as evaporation from ink fountains, exposed sections of the printing cylinder, the paper web, the paper post exit, and spilled ink. In addition, specific activities that could lead to benzene exposure, such as filling the fountains, using solvents to clean the press, and using solvents as personal cleaning agents, potentially occurred multiple times per work period. Eighteen studies were identified that reported workplace airborne concentrations in printing facilities between 1938 and 2006. Typical benzene air concentrations, considering both personal and area samples of various durations, were as high as 200 p.p.m. in the 1930s through the 1950s, 3-35 p.p.m. in the 1960s, 1.3-16 p.p.m. in the 1970s, 0.013-1 in the 1980s, and far less than 1 p.p.m. in the 1990s and 2000s. The decrease in benzene air concentrations by the late 1970s was likely to be linked to the decreased benzene content of printing materials, increased engineering controls, and to more stringent occupational exposure limits.

Undertaking Experiments in Social Sciences: Sequential, Multiple Time Series Designs for Consideration

ERIC Educational Resources Information Center

Phan, Huy P.; Ngu, Bing H.

2017-01-01

In social sciences, the use of stringent methodological approaches is gaining increasing emphasis. Researchers have recognized the limitations of cross-sectional, non-manipulative data in the study of causality. True experimental designs, in contrast, are preferred as they represent rigorous standards for achieving causal flows between variables.…

Cybersecurity Education: Bridging the Gap between Hardware and Software Domains

ERIC Educational Resources Information Center

Lukowiak, Marcin; Radziszowski, Stanislaw; Vallino, James; Wood, Christopher

2014-01-01

With the continuous growth of cyberinfrastructure throughout modern society, the need for secure computing and communication is more important than ever before. As a result, there is also an increasing need for entry-level developers who are capable of designing and building practical solutions for systems with stringent security requirements.…

Building a comprehensive mill-level database for the Industrial Sectors Integrated Solutions (ISIS) model of the U.S. pulp and paper sector.

PubMed

Modak, Nabanita; Spence, Kelley; Sood, Saloni; Rosati, Jacky Ann

2015-01-01

Air emissions from the U.S. pulp and paper sector have been federally regulated since 1978; however, regulations are periodically reviewed and revised to improve efficiency and effectiveness of existing emission standards. The Industrial Sectors Integrated Solutions (ISIS) model for the pulp and paper sector is currently under development at the U.S. Environmental Protection Agency (EPA), and can be utilized to facilitate multi-pollutant, sector-based analyses that are performed in conjunction with regulatory development. The model utilizes a multi-sector, multi-product dynamic linear modeling framework that evaluates the economic impact of emission reduction strategies for multiple air pollutants. The ISIS model considers facility-level economic, environmental, and technical parameters, as well as sector-level market data, to estimate the impacts of environmental regulations on the pulp and paper industry. Specifically, the model can be used to estimate U.S. and global market impacts of new or more stringent air regulations, such as impacts on product price, exports and imports, market demands, capital investment, and mill closures. One major challenge to developing a representative model is the need for an extensive amount of data. This article discusses the collection and processing of data for use in the model, as well as the methods used for building the ISIS pulp and paper database that facilitates the required analyses to support the air quality management of the pulp and paper sector.

Environmentally regulated aerospace coatings

NASA Technical Reports Server (NTRS)

Morris, Virginia L.

1995-01-01

Aerospace coatings represent a complex technology which must meet stringent performance requirements in the protection of aerospace vehicles. Topcoats and primers are used, primarily, to protect the structural elements of the air vehicle from exposure to and subsequent degradation by environmental elements. There are also many coatings which perform special functions, i.e., chafing resistance, rain erosion resistance, radiation and electric effects, fuel tank coatings, maskants, wire and fastener coatings. The scheduled promulgation of federal environmental regulations for aerospace manufacture and rework materials and processes will regulate the emissions of photochemically reactive precursors to smog and air toxics. Aerospace organizations will be required to identify, qualify and implement less polluting materials. The elimination of ozone depleting chemicals (ODC's) and implementation of pollution prevention requirements are added constraints which must be addressed concurrently. The broad categories of operations affected are the manufacture, operation, maintenance, and repair of military, commercial, general aviation, and space vehicles. The federal aerospace regulations were developed around the precept that technology had to be available to support the reduction of organic and air toxic emissions, i.e., the regulations cannot be technology forcing. In many cases, the regulations which are currently in effect in the South Coast Air Quality Management District (SCAQMD), located in Southern California, were used as the baseline for the federal regulations. This paper addresses strategies used by Southern California aerospace organizations to cope with these regulatory impacts on aerospace productions programs. All of these regulatory changes are scheduled for implementation in 1993 and 1994, with varying compliance dates established.

Building a Comprehensive Mill-Level Database for the Industrial Sectors Integrated Solutions (ISIS) Model of the U.S. Pulp and Paper Sector

PubMed Central

Modak, Nabanita; Spence, Kelley; Sood, Saloni; Rosati, Jacky Ann

2015-01-01

Air emissions from the U.S. pulp and paper sector have been federally regulated since 1978; however, regulations are periodically reviewed and revised to improve efficiency and effectiveness of existing emission standards. The Industrial Sectors Integrated Solutions (ISIS) model for the pulp and paper sector is currently under development at the U.S. Environmental Protection Agency (EPA), and can be utilized to facilitate multi-pollutant, sector-based analyses that are performed in conjunction with regulatory development. The model utilizes a multi-sector, multi-product dynamic linear modeling framework that evaluates the economic impact of emission reduction strategies for multiple air pollutants. The ISIS model considers facility-level economic, environmental, and technical parameters, as well as sector-level market data, to estimate the impacts of environmental regulations on the pulp and paper industry. Specifically, the model can be used to estimate U.S. and global market impacts of new or more stringent air regulations, such as impacts on product price, exports and imports, market demands, capital investment, and mill closures. One major challenge to developing a representative model is the need for an extensive amount of data. This article discusses the collection and processing of data for use in the model, as well as the methods used for building the ISIS pulp and paper database that facilitates the required analyses to support the air quality management of the pulp and paper sector. PMID:25806516

The RpoB H₄₈₁Y rifampicin resistance mutation and an active stringent response reduce virulence and increase resistance to innate immune responses in Staphylococcus aureus.

PubMed

Gao, Wei; Cameron, David R; Davies, John K; Kostoulias, Xenia; Stepnell, Justin; Tuck, Kellie L; Yeaman, Michael R; Peleg, Anton Y; Stinear, Timothy P; Howden, Benjamin P

2013-03-15

The occurrence of mutations in methicillin-resistant Staphylococcus aureus (MRSA) during persistent infection leads to antimicrobial resistance but may also impact host-pathogen interactions. Here, we investigate the host-pathogen consequences of 2 mutations arising in clinical MRSA during persistent infection: RpoB H₄₈₁Y, which is linked to rifampicin resistance, and RelA F₁₂₈Y, which is associated with an active stringent response. Allelic exchange experiments showed that both mutations cause global transcriptional changes, leading to upregulation of capsule production, with attenuated virulence in a murine bacteremia model and reduced susceptibility to both antimicrobial peptides and whole-blood killing. Disruption of capsule biosynthesis reversed these impacts on innate immune function. These data clearly link MRSA persistence and reduced virulence to the same mechanisms that alter antimicrobial susceptibility. Our study highlights the wider consequences of suboptimal antimicrobial use, where drug resistance and immune escape mechanisms coevolve, thus increasing the likelihood of treatment failure.

Regulated and unregulated emissions from modern 2010 emissions-compliant heavy-duty on-highway diesel engines

PubMed Central

Khalek, Imad A.; Blanks, Matthew G.; Merritt, Patrick M.; Zielinska, Barbara

2015-01-01

The U.S. Environmental Protection Agency (EPA) established strict regulations for highway diesel engine exhaust emissions of particulate matter (PM) and nitrogen oxides (NOx) to aid in meeting the National Ambient Air Quality Standards. The emission standards were phased in with stringent standards for 2007 model year (MY) heavy-duty engines (HDEs), and even more stringent NOX standards for 2010 and later model years. The Health Effects Institute, in cooperation with the Coordinating Research Council, funded by government and the private sector, designed and conducted a research program, the Advanced Collaborative Emission Study (ACES), with multiple objectives, including detailed characterization of the emissions from both 2007- and 2010-compliant engines. The results from emission testing of 2007-compliant engines have already been reported in a previous publication. This paper reports the emissions testing results for three heavy-duty 2010-compliant engines intended for on-highway use. These engines were equipped with an exhaust diesel oxidation catalyst (DOC), high-efficiency catalyzed diesel particle filter (DPF), urea-based selective catalytic reduction catalyst (SCR), and ammonia slip catalyst (AMOX), and were fueled with ultra-low-sulfur diesel fuel (~6.5 ppm sulfur). Average regulated and unregulated emissions of more than 780 chemical species were characterized in engine exhaust under transient engine operation using the Federal Test Procedure cycle and a 16-hr duty cycle representing a wide dynamic range of real-world engine operation. The 2010 engines’ regulated emissions of PM, NOX, nonmethane hydrocarbons, and carbon monoxide were all well below the EPA 2010 emission standards. Moreover, the unregulated emissions of polycyclic aromatic hydrocarbons (PAHs), nitroPAHs, hopanes and steranes, alcohols and organic acids, alkanes, carbonyls, dioxins and furans, inorganic ions, metals and elements, elemental carbon, and particle number were substantially (90 to >99%) lower than pre-2007-technology engine emissions, and also substantially (46 to >99%) lower than the 2007-technology engine emissions characterized in the previous study. Implications: Heavy-duty on-highway diesel engines equipped with DOC/DPF/SCR/AMOX and fueled with ultra-low-sulfur diesel fuel produced lower emissions than the stringent 2010 emission standards established by the U.S. Environmental Protection Agency. They also resulted in significant reductions in a wide range of unregulated toxic emission compounds relative to older technology engines. The increased use of newer technology (2010+) diesel engines in the on-highway sector and the adaptation of such technology by other sectors such as nonroad, displacing older, higher emissions engines, will have a positive impact on ambient levels of PM, NOx, and volatile organic compounds, in addition to many other toxic compounds. PMID:26037832

Occurrence of the regulatory nucleotides ppGpp and pppGpp following induction of the stringent response in staphylococci.

PubMed Central

Cassels, R; Oliva, B; Knowles, D

1995-01-01

The stringent response in Escherichia coli and many other organisms is regulated by the nucleotides ppGpp and pppGpp. We show here for the first time that at least six staphylococcal species also synthesize ppGpp and pppGpp upon induction of the stringent response by mupirocin. Spots corresponding to ppGpp and pppGpp on thin-layer chromatograms suggest that pppGpp is the principal regulatory nucleotide synthesized by staphylococci in response to mupirocin, rather than ppGpp as in E. coli. PMID:7665499

The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus.

PubMed

Hood, Rachel D; Higgins, Sean A; Flamholz, Avi; Nichols, Robert J; Savage, David F

2016-08-16

The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3'-diphosphate 5'-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle.

The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus

PubMed Central

Hood, Rachel D.; Higgins, Sean A.; Flamholz, Avi; Nichols, Robert J.

2016-01-01

The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3′-diphosphate 5′-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle. PMID:27486247

Stringent DDI-based Prediction of H. sapiens-M. tuberculosis H37Rv Protein-Protein Interactions

PubMed Central

2013-01-01

Background H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are very important information to illuminate the infection mechanism of M. tuberculosis H37Rv. But current H. sapiens-M. tuberculosis H37Rv PPI data are very scarce. This seriously limits the study of the interaction between this important pathogen and its host H. sapiens. Computational prediction of H. sapiens-M. tuberculosis H37Rv PPIs is an important strategy to fill in the gap. Domain-domain interaction (DDI) based prediction is one of the frequently used computational approaches in predicting both intra-species and inter-species PPIs. However, the performance of DDI-based host-pathogen PPI prediction has been rather limited. Results We develop a stringent DDI-based prediction approach with emphasis on (i) differences between the specific domain sequences on annotated regions of proteins under the same domain ID and (ii) calculation of the interaction strength of predicted PPIs based on the interacting residues in their interaction interfaces. We compare our stringent DDI-based approach to a conventional DDI-based approach for predicting PPIs based on gold standard intra-species PPIs and coherent informative Gene Ontology terms assessment. The assessment results show that our stringent DDI-based approach achieves much better performance in predicting PPIs than the conventional approach. Using our stringent DDI-based approach, we have predicted a small set of reliable H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. We also analyze the H. sapiens-M. tuberculosis H37Rv PPIs predicted by our stringent DDI-based approach using cellular compartment distribution analysis, functional category enrichment analysis and pathway enrichment analysis. The analyses support the validity of our prediction result. Also, based on an analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent DDI-based approach, we have discovered some important properties of domains involved in host-pathogen PPIs. We find that both host and pathogen proteins involved in host-pathogen PPIs tend to have more domains than proteins involved in intra-species PPIs, and these domains have more interaction partners than domains on proteins involved in intra-species PPI. Conclusions The stringent DDI-based prediction approach reported in this work provides a stringent strategy for predicting host-pathogen PPIs. It also performs better than a conventional DDI-based approach in predicting PPIs. We have predicted a small set of accurate H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. PMID:24564941

Fire safety design of a mobile quarantine facility

NASA Technical Reports Server (NTRS)

Bass, R. S.; Hirasaki, J. K.

1971-01-01

During the design phase of the Mobile Quarantine Facility (MQF), a primary consideration was fire safety. Therefore, appropriate criteria and ground rules were used in the design and construction of the facility. The fire codes and fire-requirement listings that are used by commerical airlines were supplied to the Manned Spacecraft Center (MSC) by the Federal Aviation Agency (FAA). After these codes were reviewed, a basic ground rule was adopted that flame protection for all combustible materials should be at least equivalent to or better than the standards for commercial aircraft. Because the MQF was designed to operate with an interior atmosphere of air rather than with an oxygen-enriched atmosphere such as that of the Apollo spacecraft cabin, the requirements for MQF material were not as stringent as those for the spacecraft.

Role of the Stringent Stress Response in the Antibiotic Resistance Phenotype of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Aedo, Sandra

2016-01-01

Resistance to beta-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA) requires the presence of an acquired genetic determinant, mecA or mecC, which encode penicillin-binding protein PBP2A or PBP2A′, respectively. Although all MRSA strains share a mechanism of resistance, the phenotypic expression of beta-lactam resistance shows considerable strain-to-strain variation. The stringent stress response, a stress response that results from nutrient limitation, was shown to play a key role in determining the resistance level of an MRSA strain. In the present study, we validated the impact of the stringent stress response on transcription and translation of mecA in the MRSA clinical isolate strain N315, which also carries known regulatory genes (mecI/mecR1/mecR2 and blaI/blaR1) for mecA transcription. We showed that the impact of the stringent stress response on the resistance level may be restricted to beta-lactam resistance based on a “foreign” determinant such as mecA, as opposed to resistance based on mutations in the native S. aureus determinant pbpB (encoding PBP2). Our observations demonstrate that high-level resistance mediated by the stringent stress response follows the current model of beta-lactam resistance in which the native PBP2 protein is also essential for expression of the resistance phenotype. We also show that the Staphylococcus sciuri pbpD gene (also called mecAI), the putative evolutionary precursor of mecA, confers oxacillin resistance in an S. aureus strain, generating a heterogeneous phenotype that can be converted to high and homogenous resistance by induction of the stringent stress response in the bacteria. PMID:26833147

Context-Aware Reviewer Assignment for Trust Enhanced Peer Review

PubMed Central

Li, Lei; Wang, Yan; Liu, Guanfeng; Wang, Meng; Wu, Xindong

2015-01-01

Reviewer assignment is critical to peer review systems, such as peer-reviewed research conferences or peer-reviewed funding applications, and its effectiveness is a deep concern of all academics. However, there are some problems in existing peer review systems during reviewer assignment. For example, some of the reviewers are much more stringent than others, leading to an unfair final decision, i.e., some submissions (i.e., papers or applications) with better quality are rejected. In this paper, we propose a context-aware reviewer assignment for trust enhanced peer review. More specifically, in our approach, we first consider the research area specific expertise of reviewers, and the institution relevance and co-authorship between reviewers and authors, so that reviewers with the right expertise are assigned to the corresponding submissions without potential conflict of interest. In addition, we propose a novel cross-assignment paradigm, and reviewers are cross-assigned in order to avoid assigning a group of stringent reviewers or a group of lenient reviewers to the same submission. More importantly, on top of them, we propose an academic CONtext-aware expertise relevanCe oriEnted Reviewer cross-assignmenT approach (CONCERT), which aims to effectively estimate the “true” ratings of submissions based on the ratings from all reviewers, even though no prior knowledge exists about the distribution of stringent reviewers and lenient reviewers. The experiments illustrate that compared with existing approaches, our proposed CONCERT approach can less likely assign more than one stringent reviewers or lenient reviewers to a submission simultaneously and significantly reduce the influence of ratings from stringent reviewers and lenient reviewers, leading to trust enhanced peer review and selection, no matter what kind of distributions of stringent reviewers and lenient reviewers are. PMID:26090849

Cholera Toxin Production during Anaerobic Trimethylamine N-Oxide Respiration Is Mediated by Stringent Response in Vibrio cholerae*

PubMed Central

Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M.; Lee, Kang-Mu; Yoon, Sang Sun

2014-01-01

As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae. PMID:24648517

Air Quality in Mexico City: Policies Implemented for its Improvement

NASA Astrophysics Data System (ADS)

Paramo, V.

2007-12-01

Ozone and suspended particles (PM) are two pollutants in the atmosphere of Mexico City Metropolitan Area (MCMA) that still exceed the recommended Mexican health standards. The other criteria pollutants very seldom exceed their corresponding standards. In 2006, the maximum ozone concentrations were above the health standard (0.11 ppm in 1 hour) during 59 percent of the days for an average of 2.2 hours and 130 points of the Air Quality Index (Índice Metropolitano de la Calidad del Aire - IMECA). In contrast, in 1991, 98 percent of the days exceeded the ozone health standard for an average of 6.6 hours and 200 IMECA points. With regards to PM10, in 2006, 80 percent of the sampled concentrations were below the health standard of 120 µg/m3 in 24 hours. However, the annual health standard of 50 µg/m3 is still exceeded. The air quality management in the MCMA is a difficult task due to several adverse factors. The main one is the large population that increased from nearly 15 million in 1992 to more than 18 million at present. As a result, the urban area grows in the adjoined municipalities of the State of Mexico. The vehicular fleet increases also to almost 4 million and the number of industrial facilities is at present 50,000. Consequently, the fuel consumption is very high. The daily energy consumption is estimated to be 44 million liters of equivalent of gasoline. Despite the fact that the air quality has improved in recent years, the related health standards are still exceeded and therefore it is necessary to continue applying the most cost-effective actions to improve the environment quality. Some actions that have contributed most to the reduction of pollutant emissions are the following: Continuous update of the inspection and maintenance program of the vehicular fleet; substitution of the catalytic converters at the end of their useful life; self-regulation of the diesel fleet; use of alternative fuels; update the No-Driving-Day program; establishment of more stringent emission levels of the gasoline fleet; update the detention of pollutant vehicles program; partial exemption of the inspection and maintenance program for cleaner and or highly efficient vehicles; substitution of 3,000 microbuses, 40,000 taxis and 1,200 buses; commissioning of the first Bus Rapid Transit system; implementation of a program for the emissions reduction for the 300 most polluted industrial facilities; and continuous update of the air quality environmental management programs. To continue improving the air quality in the MCMA, the environmental authorities will continue the implementation of the 2002-2010 Air Quality Improvement Program. In 2007 the Green Program was started, this includes those actions that have proven to be effective reduction of pollutant emissions and incorporates new actions for the reduction of local and global pollutant emissions. The most important of these new actions are: substitution of 9,500 microbuses; renewal of all the taxis fleet; commissioning of 10 Bus Rapid Transit lines; commissioning of Line 12 of the underground system; schedules and routes limitations to the cargo fleet; increase 5 percent the number of non-motorized trips (bicycling and walking); regulation of the private public transport passenger stops; requirement of private schools to provide school transport; regulation of non-occupied taxis in circulation; modifications to the circulation of 350 critical crossing points in the city; adoption of intelligent traffic lights systems; complete substitution of the local government vehicle's fleet; implement the inspection and maintenance of the cargo fleet; introduction of low- sulfur diesel, among other measures.

Benefits of advanced software techniques for mission planning systems

NASA Technical Reports Server (NTRS)

Gasquet, A.; Parrod, Y.; Desaintvincent, A.

1994-01-01

The increasing complexity of modern spacecraft, and the stringent requirement for maximizing their mission return, call for a new generation of Mission Planning Systems (MPS). In this paper, we discuss the requirements for the Space Mission Planning and the benefits which can be expected from Artificial Intelligence techniques through examples of applications developed by Matra Marconi Space.

Diving into Data: Developing the Capacity for Data Literacy in Teacher Education

ERIC Educational Resources Information Center

Dunlap, Karen; Piro, Jody S.

2016-01-01

Educators by definition are now required to utilize a variety of student data to shape the decisions they make and design the lessons they teach. As accountability standards become more stringent and as teachers face increasingly diverse student populations within their classrooms, they often struggle to adequately meet the needs of all learners.…

Benefits of advanced software techniques for mission planning systems

NASA Astrophysics Data System (ADS)

Gasquet, A.; Parrod, Y.; Desaintvincent, A.

1994-10-01

The increasing complexity of modern spacecraft, and the stringent requirement for maximizing their mission return, call for a new generation of Mission Planning Systems (MPS). In this paper, we discuss the requirements for the Space Mission Planning and the benefits which can be expected from Artificial Intelligence techniques through examples of applications developed by Matra Marconi Space.

Design and Evaluation of Energy Efficient Modular Classroom Structures.

ERIC Educational Resources Information Center

Brown, G. Z.; And Others

This paper describes a study that developed innovations that would enable modular builders to improve the energy performance of their classrooms without increasing their first cost. The Modern Building Systems' classroom building conforms to the stringent Oregon and Washington energy codes, and, at $18 per square foot, it is at the low end of the…

Incorporating Knowledge of Legal and Ethical Aspects into Computing Curricula of South African Universities

ERIC Educational Resources Information Center

Wayman, Ian; Kyobe, Michael

2012-01-01

As students in computing disciplines are introduced to modern information technologies, numerous unethical practices also escalate. With the increase in stringent legislations on use of IT, users of technology could easily be held liable for violation of this legislation. There is however lack of understanding of social aspects of computing, and…

U. S. light duty vehicle fleet emissions performance and the emissions impact of technology changes

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

Sabourin, M.; Platte, L

1988-01-01

This paper determines the level of improvement in Federal Test Procedure (FTP) exhaust emissions realized by typical in-use vehicles over the last twenty years as emission standards have become increasingly stringent. Furthermore, this paper explores the likelihood that in-use emission performance improvements will continue now that emission standards have stabilized.

Development of Future Scenario Emission Inventories for East Asia in Support of Multiple Modeling Studies

NASA Astrophysics Data System (ADS)

Kim, Y.; Woo, J. H.; Choi, K. C.; Lee, J. B.; Song, C. K.; Kim, S. K.; Hong, J.; Hong, S. C.; Zhang, Q.; Hong, C.; Tong, D.

2015-12-01

Future emission scenarios based on up-to-date regional socio-economic and control policy information were developed in support of climate-air quality integrated modeling research over East Asia. Two IPCC-participated Integrated Assessment Models(IAMs) were used to developed those scenario pathways. The two emission processing systems, KU-EPS and SMOKE-Asia, were used to convert these future scenario emissions to comprehensive chemical transport model-ready form. The NIER/KU-CREATE (Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment) served as the regional base-year emission inventory. For anthropogenic emissions, it has 54 fuel classes, 201 sub-sectors and 13 pollutants, including CO2, CH4, N2O, SO2, NOx, CO, NMVOC, NH3, OC, BC, PM10, PM2.5, and mercury. Fast energy growth and aggressive penetration of the control measures make emissions projection very active for East Asia. Despite of more stringent air pollution control policies by the governments, however, air quality over the region seems not been improved as much - even worse in many cases. The needs of more scientific understanding of inter-relationship among emissions, transport, chemistry over the region are very high to effectively protect public health and ecosystems against ozone, fine particles, and other toxic pollutants in the air. After developing these long-term future emissions, therefore, we also tried to apply our future scenarios to develop the present emissions inventory for chemical weather forecasting and aircraft field campaign. On site, we will present; 1) the future scenario development framework and process methodologies, 2) initial development results of the future emission pathways, 3) present emission inventories from short-term projection, and 4) air quality modeling performance improvements over the region.

GPS navigation algorithms for Autonomous Airborne Refueling of Unmanned Air Vehicles

NASA Astrophysics Data System (ADS)

Khanafseh, Samer Mahmoud

Unmanned Air Vehicles (UAVs) have recently generated great interest because of their potential to perform hazardous missions without risking loss of life. If autonomous airborne refueling is possible for UAVs, mission range and endurance will be greatly enhanced. However, concerns about UAV-tanker proximity, dynamic mobility and safety demand that the relative navigation system meets stringent requirements on accuracy, integrity, and continuity. In response, this research focuses on developing high-performance GPS-based navigation architectures for Autonomous Airborne Refueling (AAR) of UAVs. The AAR mission is unique because of the potentially severe sky blockage introduced by the tanker. To address this issue, a high-fidelity dynamic sky blockage model was developed and experimentally validated. In addition, robust carrier phase differential GPS navigation algorithms were derived, including a new method for high-integrity reacquisition of carrier cycle ambiguities for recently-blocked satellites. In order to evaluate navigation performance, world-wide global availability and sensitivity covariance analyses were conducted. The new navigation algorithms were shown to be sufficient for turn-free scenarios, but improvement in performance was necessary to meet the difficult requirements for a general refueling mission with banked turns. Therefore, several innovative methods were pursued to enhance navigation performance. First, a new theoretical approach was developed to quantify the position-domain integrity risk in cycle ambiguity resolution problems. A mechanism to implement this method with partially-fixed cycle ambiguity vectors was derived, and it was used to define tight upper bounds on AAR navigation integrity risk. A second method, where a new algorithm for optimal fusion of measurements from multiple antennas was developed, was used to improve satellite coverage in poor visibility environments such as in AAR. Finally, methods for using data-link extracted measurements as an additional inter-vehicle ranging measurement were also introduced. The algorithms and methods developed in this work are generally applicable to realize high-performance GPS-based navigation in partially obstructed environments. Navigation performance for AAR was quantified through covariance analysis, and it was shown that the stringent navigation requirements for this application are achievable. Finally, a real-time implementation of the algorithms was developed and successfully validated in autopiloted flight tests.

Polybrominated diphenyl ether (PBDE) concentrations and resulting exposure in homes in California: relationships among passive air, surface wipe and dust concentrations, and temporal variability

PubMed Central

Bennett, D. H.; Moran, R. E.; Wu, X. (May); Tulve, N. S.; Clifton, M. S.; Colón, M.; Weathers, W.; Sjödin, A.; Jones, R.; Hertz-Picciotto, I.

2016-01-01

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam, electronics, and other home furnishings. A field study was conducted that enrolled 139 households from California, which has had more stringent flame retardant requirements than other countries and areas. The study collected passive air, floor and indoor window surface wipes, and dust samples (investigator collected using an HVS3 and vacuum cleaner) in each home. PentaBDE and BDE209 were detected in the majority of the dust samples and many floor wipe samples, but the detection in air and window wipe samples was relatively low. Concentrations of each PBDE congener in different indoor environmental media were moderately correlated, with correlation coefficients ranging between 0.42 and 0.68. Correlation coefficients with blood levels were up to 0.65 and varied between environmental media and age group. Both investigator-collected dust and floor wipes were correlated with serum levels for a wide range of congeners. These two sample types also had a relatively high fraction of samples with adequate mass for reliable quantification. In 42 homes, PBDE levels measured in the same environmental media in the same home 1 year apart were statistically correlated (correlation coefficients: 0.57–0.90), with the exception of BDE209 which was not well correlated longitudinally. PMID:24832910

Evaluating Environmental Governance along Cross-Border Electricity Supply Chains with Policy-Informed Life Cycle Assessment: The California-Mexico Energy Exchange.

PubMed

Bolorinos, Jose; Ajami, Newsha K; Muñoz Meléndez, Gabriela; Jackson, Robert B

2018-05-01

This paper presents a "policy-informed" life cycle assessment of a cross-border electricity supply chain that links the impact of each unit process to its governing policy framework. An assessment method is developed and applied to the California-Mexico energy exchange as a unique case study. CO 2 -equivalent emissions impacts, water withdrawals, and air quality impacts associated with California's imports of electricity from Mexican combined-cycle facilities fueled by natural gas from the U.S. Southwest are estimated, and U.S. and Mexican state and federal environmental regulations are examined to assess well-to-wire consistency of energy policies. Results indicate most of the water withdrawn per kWh exported to California occurs in Baja California, most of the air quality impacts accrue in the U.S. Southwest, and emissions of CO 2 -equivalents are more evenly divided between the two regions. California energy policy design addresses generation-phase CO 2 emissions, but not upstream CO 2 -eq emissions of methane during the fuel cycle. Water and air quality impacts are not regulated consistently due to varying U.S. state policies and a lack of stringent federal regulation of unconventional gas development. Considering local impacts and the regulatory context where they occur provides essential qualitative information for functional-unit-based measures of life cycle impact and is necessary for a more complete environmental impact assessment.

40 CFR 281.37 - Financial responsibility for UST systems containing petroleum.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Financial responsibility for UST... for No-Less-Stringent § 281.37 Financial responsibility for UST systems containing petroleum. (a) In order to be considered no less stringent than the federal requirements for financial responsibility for...

49 CFR 355.21 - Regulatory review.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) It applies to interstate commerce; (iii) It is more stringent than the FMCSRs in that it is more... law or regulation applies to interstate commerce and is more stringent than the FMCSRs, the State shall determine: (i) The safety benefits associated with such State law or regulation; and (ii) The...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

40 CFR 503.5 - Additional or more stringent requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements. 503.5 Section 503.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.5 Additional or more... the use or disposal of sewage sludge in addition to or more stringent than the requirements in this...

Rise Time Reduction of Thermal Actuators Operated in Air and Water through Optimized Pre-Shaped Open-Loop Driving.

PubMed

Larsen, T; Doll, J C; Loizeau, F; Hosseini, N; Peng, A W; Fantner, G; Ricci, A J; Pruitt, B L

2017-01-01

Electrothermal actuators have many advantages compared to other actuators used in Micro-Electro-Mechanical Systems (MEMS). They are simple to design, easy to fabricate and provide large displacements at low voltages. Low voltages enable less stringent passivation requirements for operation in liquid. Despite these advantages, thermal actuation is typically limited to a few kHz bandwidth when using step inputs due to its intrinsic thermal time constant. However, the use of pre-shaped input signals offers a route for reducing the rise time of these actuators by orders of magnitude. We started with an electrothermally actuated cantilever having an initial 10-90% rise time of 85 μs in air and 234 μs in water for a standard open-loop step input. We experimentally characterized the linearity and frequency response of the cantilever when operated in air and water, allowing us to obtain transfer functions for the two cases. We used these transfer functions, along with functions describing desired reduced rise-time system responses, to numerically simulate the required input signals. Using these pre-shaped input signals, we improved the open-loop 10-90% rise time from 85 μs to 3 μs in air and from 234 μs to 5 μs in water, an improvement by a factor of 28 and 47, respectively. Using this simple control strategy for MEMS electrothermal actuators makes them an attractive alternative to other high speed micromechanical actuators such as piezoelectric stacks or electrostatic comb structures which are more complex to design, fabricate, or operate.

Novel pppGpp binding site at the C-terminal region of the Rel enzyme from Mycobacterium smegmatis.

PubMed

Syal, Kirtimaan; Joshi, Himanshu; Chatterji, Dipankar; Jain, Vikas

2015-10-01

Mycobacterium tuberculosis elicits the stringent response under unfavorable growth conditions, such as those encountered by the pathogen inside the host. The hallmark of this response is production of guanosine tetra- and pentaphosphates, collectively termed (p)ppGpp, which have pleiotropic effects on the bacterial physiology. As the stringent response is connected to survival under stress, it is now being targeted for developing inhibitors against bacterial persistence. The Rel enzyme in mycobacteria has two catalytic domains at its N-terminus that are involved in the synthesis and hydrolysis of (p)ppGpp, respectively. However, the function of the C-terminal region of the protein remained unknown. Here, we have identified a binding site for pppGpp in the C-terminal region of Rel. The binding affinity of pppGpp was quantified by isothermal titration calorimetry. The binding site was determined by crosslinking using the nucleotide analog azido-pppGpp, and examining the crosslink product by mass spectrometry. Additionally, mutations in the Rel protein were created to confirm the site of pppGpp binding by isothermal titration calorimetry. These mutants showed increased pppGpp synthesis and reduced hydrolytic activity. We believe that binding of pppGpp to Rel provides a feedback mechanism that allows the protein to detect and adjust the (p)ppGpp level in the cell. Our work suggests that such sites should also be considered while designing inhibitors to target the stringent response. © 2015 FEBS.

An Active Flow Circulation Controlled Flap Concept for General Aviation Aircraft Applications

NASA Technical Reports Server (NTRS)

Jones, Gregory S.; Viken, Sally A.; Washburn, Anthony E.; Jenkins, Luther N.; Cagle, C. Mark

2002-01-01

A recent focus on revolutionary aerodynamic concepts has highlighted the technology needs of general aviation and personal aircraft. New and stringent restrictions on these types of aircraft have placed high demands on aerodynamic performance, noise, and environmental issues. Improved high lift performance of these aircraft can lead to slower takeoff and landing speeds that can be related to reduced noise and crash survivability issues. Circulation Control technologies have been around for 65 years, yet have been avoided due to trade offs of mass flow, pitching moment, perceived noise etc. The need to improve the circulation control technology for general aviation and personal air-vehicle applications is the focus of this paper. This report will describe the development of a 2-D General Aviation Circulation Control (GACC) wing concept that utilizes a pulsed pneumatic flap.

Multilevel DC Link Inverter for Brushless Permanent Magnet Motors with Very Low Inductance

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

Su, G.J.

2001-10-29

Due to their long effective air gaps, permanent magnet motors tend to have low inductance. The use of ironless stator structure in present high power PM motors (several tens of kWs) reduces the inductance even further (< 100 {micro}H). This low inductance imposes stringent current regulation demands for the inverter to obtain acceptable current ripple. An analysis of the current ripple for these low inductance brushless PM motors shows that a standard inverter with the most commonly used IGBT switching devices cannot meet the current regulation demands and will produce unacceptable current ripples due to the IGBT's limited switching frequency.more » This paper introduces a new multilevel dc link inverter, which can dramatically reduce the current ripple for brushless PM motor drives. The operating principle and design guidelines are included.« less

Safety Precautions and Operating Procedures in an (A)BSL-4 Laboratory: 1. Biosafety Level 4 Suit Laboratory Suite Entry and Exit Procedures.

PubMed

Janosko, Krisztina; Holbrook, Michael R; Adams, Ricky; Barr, Jason; Bollinger, Laura; Newton, Je T'aime; Ntiforo, Corrie; Coe, Linda; Wada, Jiro; Pusl, Daniela; Jahrling, Peter B; Kuhn, Jens H; Lackemeyer, Matthew G

2016-10-03

Biosafety level 4 (BSL-4) suit laboratories are specifically designed to study high-consequence pathogens for which neither infection prophylaxes nor treatment options exist. The hallmarks of these laboratories are: custom-designed airtight doors, dedicated supply and exhaust airflow systems, a negative-pressure environment, and mandatory use of positive-pressure ("space") suits. The risk for laboratory specialists working with highly pathogenic agents is minimized through rigorous training and adherence to stringent safety protocols and standard operating procedures. Researchers perform the majority of their work in BSL-2 laboratories and switch to BSL-4 suit laboratories when work with a high-consequence pathogen is required. Collaborators and scientists considering BSL-4 projects should be aware of the challenges associated with BSL-4 research both in terms of experimental technical limitations in BSL-4 laboratory space and the increased duration of such experiments. Tasks such as entering and exiting the BSL-4 suit laboratories are considerably more complex and time-consuming compared to BSL-2 and BSL-3 laboratories. The focus of this particular article is to address basic biosafety concerns and describe the entrance and exit procedures for the BSL-4 laboratory at the NIH/NIAID Integrated Research Facility at Fort Detrick. Such procedures include checking external systems that support the BSL-4 laboratory, and inspecting and donning positive-pressure suits, entering the laboratory, moving through air pressure-resistant doors, and connecting to air-supply hoses. We will also discuss moving within and exiting the BSL-4 suit laboratories, including using the chemical shower and removing and storing positive-pressure suits.

Sorbent Nanotechnologies for Water Cleaning

NASA Astrophysics Data System (ADS)

Ahmed, Snober

Despite decades of regulatory efforts to mitigate water pollution, many chemicals, particularly heavy metals, still present risks to human health. In addition to direct exposure, certain metals such as mercury threaten public health due to its persistence, bioaccumulation and bioamplification throughout the food chain. A number of U.S. Federal and State regulations have been established to reduce the levels of mercury in water. Activated carbon (AC) has been widely explored for the removal of mercury. However, AC suffers from many limitations inherent to its chemical properties, and it becomes increasingly challenging to meet current and future regulations by simply modifying AC to enhance its performance. Recently, the performance of nanosorbents have been studied in order to removal pollutants. Nanosorbents utilize the ultra-high reactive surface of nanoparticles for rapid, effective and even permanent sequestration of heavy metals from water and air, thus showed promising results as compared to AC. The goal of this thesis research is to develop nanomaterial-based sorbents for the removal of mercury from water. It describes the development of a new solid-support assisted growth of selenium nanoparticles, their use for water remediation, and the development of a new nanoselenium-based sorbent sponge for fast and efficient mercury removal. The nanoselenium sorbent not only shows irreversible interaction with mercury but also exhibits remarkable properties by overcoming the limitations of AC. The nanoselenium sponge was shown to remove mercury to undetectable levels within one minute. This new sponge technology would have an impact on inspiring new stringent regulations and lowering costs to help industries meet regulatory requirements, which will ultimately help improve air and water quality, aquatic life and public health.

Safety Precautions and Operating Procedures in an (A)BSL-4 Laboratory: 1. Biosafety Level 4 Suit Laboratory Suite Entry and Exit Procedures

PubMed Central

Janosko, Krisztina; Holbrook, Michael R.; Adams, Ricky; Barr, Jason; Bollinger, Laura; Newton, Je T'aime; Ntiforo, Corrie; Coe, Linda; Wada, Jiro; Pusl, Daniela; Jahrling, Peter B.; Kuhn, Jens H.; Lackemeyer, Matthew G.

2016-01-01

Biosafety level 4 (BSL-4) suit laboratories are specifically designed to study high-consequence pathogens for which neither infection prophylaxes nor treatment options exist. The hallmarks of these laboratories are: custom-designed airtight doors, dedicated supply and exhaust airflow systems, a negative-pressure environment, and mandatory use of positive-pressure (“space”) suits. The risk for laboratory specialists working with highly pathogenic agents is minimized through rigorous training and adherence to stringent safety protocols and standard operating procedures. Researchers perform the majority of their work in BSL-2 laboratories and switch to BSL-4 suit laboratories when work with a high-consequence pathogen is required. Collaborators and scientists considering BSL-4 projects should be aware of the challenges associated with BSL-4 research both in terms of experimental technical limitations in BSL-4 laboratory space and the increased duration of such experiments. Tasks such as entering and exiting the BSL-4 suit laboratories are considerably more complex and time-consuming compared to BSL-2 and BSL-3 laboratories. The focus of this particular article is to address basic biosafety concerns and describe the entrance and exit procedures for the BSL-4 laboratory at the NIH/NIAID Integrated Research Facility at Fort Detrick. Such procedures include checking external systems that support the BSL-4 laboratory, and inspecting and donning positive-pressure suits, entering the laboratory, moving through air pressure-resistant doors, and connecting to air-supply hoses. We will also discuss moving within and exiting the BSL-4 suit laboratories, including using the chemical shower and removing and storing positive-pressure suits. PMID:27768063

Student Research and Ethics: Contributing to the Debate

ERIC Educational Resources Information Center

Winder, Belinda; Brunsden, Vivienne; Farnsworth, Bill

2007-01-01

In this article, the authors comment on Hugh Foot's article on student research and ethics ["Psychology Teaching Review," 12(1), 82-86 (2006)] The authors agree with Foot that there is no case for accepting less stringent ethical criteria when the researcher is a student. However, they argue that greater attention and more stringent measures…

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... regulations. 730.11 Section 730.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT... Register setting forth the text or a summary of any State law or regulation initially determined by him to... stringent land use and environmental controls and regulations of coal exploration and surface coal mining...

49 CFR 350.333 - What are the guidelines for the compatibility review?

Code of Federal Regulations, 2010 CFR

2010-10-01

... to interstate or intrastate commerce Less stringent or more stringent Action authorized (1) Yes Compatible—Interstate and intrastate commerce enforcement authorized. (2) No Intrastate Refer to § 350.341 (3... authorized if the State can demonstrate the law or regulation has a safety benefit or does not create an...

40 CFR 35.910-7 - Fiscal Year 1977 Supplemental Appropriations Act allotments.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (secondary treatment, more stringent treatment required to meet water quality standards, and interceptor..., and V (secondary treatment, more stringent treatment required to meet water quality standards... Mexico 3,272,000 New York 105,294,000 North Carolina 20,722,000 North Dakota 3,272,000 Ohio 55,522,000...

76 FR 74057 - Clean Water Act Section 303(d): Availability of List Decisions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-30

... for which existing technology-based pollution controls are not stringent enough to attain or maintain... marine criterion for dissolved oxygen was not attained in these segments. EPA is providing the public the... which existing technology-based pollution controls are not stringent enough to attain or maintain State...

Bee guide to complying with the Safe Drinking Water Act. Final report

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

Garland, J.G.; Acker, A.M.

This report provides current information on the Safe Drinking Water Act and recent amendments. The report describes the evolution of the Safe Drinking Water Act and the responsibilities of base personnel involved in compliance with the Act. It also describes the monitoring requirements, analytical requirements, best available technology for controlling contaminants, and public notification requirements for regulated contaminants. The appendixes include proposed contaminants and state water quality agencies. Each Air Force public water distribution system (PWDS) must comply with the SDWA, and the National Primary Drinking Water Regulations (NPDWRs). In the United States and its territories, the provisions of themore » SDWA and the NPDWRs are enforced by the states except in the few instances in which the state has not been delegated primary enforcement responsibility (primacy) by the EPA. States that have primacy may establish drinking water regulations, monitoring schedules, and reporting requirements more stringent than, or in addition to, those in the NPDWRs. Air Force public water systems in these states are required to comply with these additional requirements as well as federal enforcement actions as carried out by the EPA Regional Office.« less

Regulation of early mRNA synthesis after bacteriophage T4 infection of Escherichia coli.

PubMed Central

Linder, C H; Fast, R

1975-01-01

Regulation of T4-specific mRNA synthesis was studied during leucine starvation of a leucine-requiring stringent Escherichia coli B strain. This was done by imposing starvation prior to T4 infection and then letting RNA synthesis proceed for different time periods. Rifampin or streptolydigin was added to stop further RNA synthesis, and protein synthesis was restored by addition of leucine. Samples were withdrawn at different times, and the enzyme-forming capacities found that, during conditions which elicit the stringent response in uninfected bacteria, immediate early mRNA is not stringently regulated. This conclusion contradicts the earlier conclusion of others, obtained by measuring incorporation of radioactive uracil; this is explained by the observation of Edlin and Neuhard (1967), confirmed and extended by us to the T4-infected cell, that the incorporation of uracil into RNA of a stringent strain is virtually blocked by amino acid starvation, whereas that of adenine continues at 30 to 50% of the rate seen in the presence of the required amino acid. PMID:1099229

Characterizing multi-pollutant air pollution in China: Comparison of three air quality indices.

PubMed

Hu, Jianlin; Ying, Qi; Wang, Yungang; Zhang, Hongliang

2015-11-01

Multi-pollutant air pollution (i.e., several pollutants reaching very high concentrations simultaneously) frequently occurs in many regions across China. Air quality index (AQI) is used worldwide to inform the public about levels of air pollution and associated health risks. The current AQI approach used in China is based on the maximum value of individual pollutants, and does not consider the combined health effects of exposure to multiple pollutants. In this study, two novel alternative indices--aggregate air quality index (AAQI) and health-risk based air quality index (HAQI)--were calculated based on data collected in six megacities of China (Beijing, Shanghai, Guangzhou, Shjiazhuang, Xi'an, and Wuhan) during 2013 to 2014. Both AAQI and HAQI take into account the combined health effects of various pollutants, and the HAQI considers the exposure (or concentration)-response relationships of pollutants. AAQI and HAQI were compared to AQI to examine the effectiveness of the current AQI in characterizing multi-pollutant air pollution in China. The AAQI and HAQI values are higher than the AQI on days when two or more pollutants simultaneously exceed the Chinese Ambient Air Quality Standards (CAAQS) 24-hour Grade II standards. The results of the comparison of the classification of risk categories based on the three indices indicate that the current AQI approach underestimates the severity of health risk associated with exposure to multi-pollutant air pollution. For the AQI-based risk category of 'unhealthy', 96% and 80% of the days would be 'very unhealthy' or 'hazardous' if based on AAQI and HAQI, respectively; and for the AQI-based risk category of 'very unhealthy', 67% and 75% of the days would be 'hazardous' if based on AAQI and HAQI, respectively. The results suggest that the general public, especially sensitive population groups such as children and the elderly, should take more stringent actions than those currently suggested based on the AQI approach during high air pollution events. Sensitivity studies were conducted to examine the assumptions used in the AAQI and HAQI approaches. Results show that AAQI is sensitive to the choice of pollutant irrelevant constant. HAQI is sensitive to the choice of both threshold values and pollutants included in total risk calculation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Auralization Architectures for NASA?s Next Generation Aircraft Noise Prediction Program

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Lopes, Leonard V.; Burley, Casey L.; Aumann, Aric R.

2013-01-01

Aircraft community noise is a significant concern due to continued growth in air traffic, increasingly stringent environmental goals, and operational limitations imposed by airport authorities. The assessment of human response to noise from future aircraft can only be afforded through laboratory testing using simulated flyover noise. Recent work by the authors demonstrated the ability to auralize predicted flyover noise for a state-of-the-art reference aircraft and a future hybrid wing body aircraft concept. This auralization used source noise predictions from NASA's Aircraft NOise Prediction Program (ANOPP) as input. The results from this process demonstrated that auralization based upon system noise predictions is consistent with, and complementary to, system noise predictions alone. To further develop and validate the auralization process, improvements to the interfaces between the synthesis capability and the system noise tools are required. This paper describes the key elements required for accurate noise synthesis and introduces auralization architectures for use with the next-generation ANOPP (ANOPP2). The architectures are built around a new auralization library and its associated Application Programming Interface (API) that utilize ANOPP2 APIs to access data required for auralization. The architectures are designed to make the process of auralizing flyover noise a common element of system noise prediction.

Distributed collaborative decision support environments for predictive awareness

NASA Astrophysics Data System (ADS)

McQuay, William K.; Stilman, Boris; Yakhnis, Vlad

2005-05-01

The past decade has produced significant changes in the conduct of military operations: asymmetric warfare, the reliance on dynamic coalitions, stringent rules of engagement, increased concern about collateral damage, and the need for sustained air operations. Mission commanders need to assimilate a tremendous amount of information, rapidly assess the enemy"s course of action (eCOA) or possible actions and promulgate their own course of action (COA) - a need for predictive awareness. Decision support tools in a distributed collaborative environment offer the capability of decomposing complex multitask processes and distributing them over a dynamic set of execution assets that include modeling, simulations, and analysis tools. Revolutionary new approaches to strategy generation and assessment such as Linguistic Geometry (LG) permit the rapid development of COA vs. enemy COA (eCOA). LG tools automatically generate and permit the operators to take advantage of winning strategies and tactics for mission planning and execution in near real-time. LG is predictive and employs deep "look-ahead" from the current state and provides a realistic, reactive model of adversary reasoning and behavior. Collaborative environments provide the framework and integrate models, simulations, and domain specific decision support tools for the sharing and exchanging of data, information, knowledge, and actions. This paper describes ongoing research efforts in applying distributed collaborative environments to decision support for predictive mission awareness.

Understanding Emissions in East Asia - The KORUS 2015 Emissions Inventory

NASA Astrophysics Data System (ADS)

Woo, J. H.; Kim, Y.; Park, R.; Choi, Y.; Simpson, I. J.; Emmons, L. K.; Streets, D. G.

2017-12-01

The air quality over Northeast Asia have been deteriorated for decades due to high population and energy use in the region. Despite of more stringent air pollution control policies by the governments, air quality over the region seems not been improved as much - even worse sometimes. The needs of more scientific understanding of inter-relationship among emissions, transport, chemistry over the region are much higher to effectively protect public health and ecosystems. Two aircraft filed campaigns targeting year 2016, MAPS-Seoul and KORUS-AQ, have been organized to study the air quality of over Korea and East Asia relating to chemical evolution, emission inventories, trans-boundary contribution, and satellite application. We developed a new East-Asia emissions inventory, named KORUS2015, based on NIER/KU-CREATE (Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment), in support of the filed campaigns. For anthropogenic emissions, it has 54 fuel classes, 201 sub-sectors and 13 pollutants, including CO2, SO2, NOx, CO, NMVOC, NH3, PM10, and PM2.5. Since the KORUS2015 emissions framework was developed using the integrated climate and air quality assessment modeling framework (i.e. GAINS) and is fully connected with the comprehensive emission processing/modeling systems (i.e. SMOKE, KU-EPS, and MEGAN), it can be effectively used to support atmospheric field campaigns for science and policy. During the field campaigns, we are providing modeling emissions inventory to participating air quality models, such as CMAQ, WRF-Chem, CAMx, GEOS-Chem, MOZART, for forecasting and post-analysis modes. Based on initial assessment of those results, we are improving our emissions, such as VOC speciation, biogenic VOCs modeling. From the 2nditeration between emissions and modeling/measurement, further analysis results will be presented at the conference. Acknowledgements : This subject is supported by Korea Ministry of Environment as "Climate Change Correspondence Program." This work was supported under the framework of national strategy project on fine particulate matters by Ministry of Science, ICT and Future Planning.

Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (p)ppGpp synthase

PubMed Central

Brockmann-Gretza, Olaf; Kalinowski, Jörn

2006-01-01

Background The stringent response is the initial reaction of microorganisms to nutritional stress. During stringent response the small nucleotides (p)ppGpp act as global regulators and reprogram bacterial transcription. In this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing Corynebacterium glutamicum. Results The transcriptome of a C. glutamicum rel gene deletion mutant, unable to synthesize (p)ppGpp and to induce the stringent response, was compared with that of its rel-proficient parent strain by microarray analysis. A total of 357 genes were found to be transcribed differentially in the rel-deficient mutant strain. In a second experiment, the stringent response was induced by addition of DL-serine hydroxamate (SHX) in early exponential growth phase. The time point of the maximal effect on transcription was determined by real-time RT-PCR using the histidine and serine biosynthetic genes. Transcription of all of these genes reached a maximum at 10 minutes after SHX addition. Microarray experiments were performed comparing the transcriptomes of SHX-induced cultures of the rel-proficient strain and the rel mutant. The differentially expressed genes were grouped into three classes. Class A comprises genes which are differentially regulated only in the presence of an intact rel gene. This class includes the non-essential sigma factor gene sigB which was upregulated and a large number of genes involved in nitrogen metabolism which were downregulated. Class B comprises genes which were differentially regulated in response to SHX in both strains, independent of the rel gene. A large number of genes encoding ribosomal proteins fall into this class, all being downregulated. Class C comprises genes which were differentially regulated in response to SHX only in the rel mutant. This class includes genes encoding putative stress proteins and global transcriptional regulators that might be responsible for the complex transcriptional patterns detected in the rel mutant when compared directly with its rel-proficient parent strain. Conclusion In C. glutamicum the stringent response enfolds a fast answer to an induced amino acid starvation on the transcriptome level. It also showed some significant differences to the transcriptional reactions occuring in Escherichia coli and Bacillus subtilis. Notable are the rel-dependent regulation of the nitrogen metabolism genes and the rel-independent regulation of the genes encoding ribosomal proteins. PMID:16961923

Analysis of multiuser mixed RF/FSO relay networks for performance improvements in Cloud Computing-Based Radio Access Networks (CC-RANs)

NASA Astrophysics Data System (ADS)

Alimi, Isiaka A.; Monteiro, Paulo P.; Teixeira, António L.

2017-11-01

The key paths toward the fifth generation (5G) network requirements are towards centralized processing and small-cell densification systems that are implemented on the cloud computing-based radio access networks (CC-RANs). The increasing recognitions of the CC-RANs can be attributed to their valuable features regarding system performance optimization and cost-effectiveness. Nevertheless, realization of the stringent requirements of the fronthaul that connects the network elements is highly demanding. In this paper, considering the small-cell network architectures, we present multiuser mixed radio-frequency/free-space optical (RF/FSO) relay networks as feasible technologies for the alleviation of the stringent requirements in the CC-RANs. In this study, we use the end-to-end (e2e) outage probability, average symbol error probability (ASEP), and ergodic channel capacity as the performance metrics in our analysis. Simulation results show the suitability of deployment of mixed RF/FSO schemes in the real-life scenarios.

ATP-Induced IL-1β Specific Secretion: True Under Stringent Conditions.

PubMed

Stoffels, Monique; Zaal, Ruben; Kok, Nina; van der Meer, Jos W M; Dinarello, Charles A; Simon, Anna

2015-01-01

Interleukin-1β is a potent proinflammatory cytokine, of which processing and secretion are tightly regulated. After exposure to various stimuli, mononuclear phagocytes synthesize the inactive precursor (pro-IL-1β), which is then cleaved intracellularly by caspase-1 and secreted. A widely used method for in vitro secretion of IL-1β employs LPS-primed human peripheral blood monocytes. Subsequently, adenosine triphosphate (ATP) is added to the cells in order to trigger the P2X7 receptor resulting in processing and secretion of mature IL-1β. However, it is often reported that secretion is due to cytotoxic effects of ATP with P2X7 receptor-activation-related cell death. We have challenged this concept and demonstrate IL-1β specific secretion, since there is no increase in cell death and IL-1α and IL-18 are not released in the same cultures. More importantly we show that these conclusions can only be drawn under stringent experimental conditions.

Constraints and consequences of the emergence of amino acid repeats in eukaryotic proteins.

PubMed

Chavali, Sreenivas; Chavali, Pavithra L; Chalancon, Guilhem; de Groot, Natalia Sanchez; Gemayel, Rita; Latysheva, Natasha S; Ing-Simmons, Elizabeth; Verstrepen, Kevin J; Balaji, Santhanam; Babu, M Madan

2017-09-01

Proteins with amino acid homorepeats have the potential to be detrimental to cells and are often associated with human diseases. Why, then, are homorepeats prevalent in eukaryotic proteomes? In yeast, homorepeats are enriched in proteins that are essential and pleiotropic and that buffer environmental insults. The presence of homorepeats increases the functional versatility of proteins by mediating protein interactions and facilitating spatial organization in a repeat-dependent manner. During evolution, homorepeats are preferentially retained in proteins with stringent proteostasis, which might minimize repeat-associated detrimental effects such as unregulated phase separation and protein aggregation. Their presence facilitates rapid protein divergence through accumulation of amino acid substitutions, which often affect linear motifs and post-translational-modification sites. These substitutions may result in rewiring protein interaction and signaling networks. Thus, homorepeats are distinct modules that are often retained in stringently regulated proteins. Their presence facilitates rapid exploration of the genotype-phenotype landscape of a population, thereby contributing to adaptation and fitness.

A subchronic inhalation toxicity study in rats exposed to silicon carbide whiskers.

PubMed

Lapin, C A; Craig, D K; Valerio, M G; McCandless, J B; Bogoroch, R

1991-01-01

To determine whether inhaled silicon carbide whiskers (SiC) cause lung damage in rats, four groups (50 males/50 females each) of rats were exposed to air only or to one of three concentrations of SiC 6 hr/day, 5 days/week for 13 weeks. Half (25 males/25 females/group) were euthanized at the end of exposure, the remainder 26 weeks later. Mean concentrations were 0, 630, 1746, and 7276 SiC whiskers/ml (0.09, 3.93, 10.7, and 60.5 mg/m3). Although there were no concentration-related changes in body weight, clinical chemistry, or hematological data attributable to SiC, lung weights were increased in the high concentration exposure group at both euthanization times. In all whisker-exposed groups, after 13 weeks of exposure, the incidence of the following lung and lymph node lesions was higher than in controls: inflammatory lesions; bronchiolar, alveolar, and pleural wall thickening; focal pleural fibrosis in lung; and reactive lymphoid hyperplasia in bronchial and mediastinal lymph nodes. After 26 weeks of recovery, lung inflammatory lesions had decreased and fewer rats had enlarged lymph nodes, but the incidence of alveolar wall thickening, focal pleural wall thickening, and adenomatous hyperplasia of lung had increased further. Incidence and severity appeared to be dose-related. Therefore, until longer term studies are undertaken and it is established whether the above observed lesions will progress to more severe pathological entities, it is prudent to adopt stringent handling procedures for silicon carbide whiskers.

Impact of reformulated fuels on motor vehicle emissions

NASA Astrophysics Data System (ADS)

Kirchstetter, Thomas

Motor vehicles continue to be an important source of air pollution. Increased vehicle travel and degradation of emission control systems have offset some of the effects of increasingly stringent emission standards and use of control technologies. A relatively new air pollution control strategy is the reformulation of motor vehicle fuels, both gasoline and diesel, to make them cleaner- burning. Field experiments in a heavily traveled northern California roadway tunnel revealed that use of oxygenated gasoline reduced on-road emissions of carbon monoxide (CO) and volatile organic compounds (VOC) by 23 +/- 6% and 19 +/- 8%, respectively, while oxides of nitrogen (NOx) emissions were not significantly affected. The introduction of reformulated gasoline (RFG) in California led to large changes in gasoline composition including decreases in alkene, aromatic, benzene, and sulfur contents, and an increase in oxygen content. The combined effects of RFG and fleet turnover between summers 1994 and 1997 were decreases in on-road vehicle exhaust emissions of CO, non-methane VOC, and NOx by 31 +/- 5, 43 +/- 8, and 18 +/- 4%, respectively. Although it was difficult to separate the fleet turnover and RFG contributions to these changes, it was clear that the effect of RFG was greater for VOC than for NOx. The RFG effect on exhaust emissions of benzene was a 30-40% reduction. Use of RFG reduced the reactivity of liquid gasoline and gasoline headspace vapors by 23 and 19%, respectively. Increased use of methyl tert-butyl ether in gasoline led to increased concentrations of highly reactive formaldehyde and isobutene in vehicle exhaust. As a result, RFG reduced the reactivity of exhaust emissions by only about 5%. Per unit mass of fuel burned, heavy-duty diesel trucks emit about 25 times more fine particle mass and 15-20 times the number of fine particles compared to light-duty vehicles. Exhaust fine particle emissions from heavy-duty diesels contain more black carbon than particulate matter emissions from light-duty vehicles (52 vs. 32% of PM2.5 mass). Sulfate emission rates measured for heavy-duty diesel trucks fueled with low- sulfur, low-aromatic diesel are significantly lower than emission rates reported before the introduction of cleaner-burning diesel fuel. Statewide fuel consumption and measured emission rates indicate that diesel vehicles in California are responsible for nearly half of NOx emissions and greater than three quarters of exhaust fine particle emissions from on-road motor vehicles.

Downsizing Antenna Technologies for Mobile and Satellite Communications

NASA Technical Reports Server (NTRS)

Huang, J.; Densmore, A.; Tulintseff, A.; Jamnejad, V.

1993-01-01

Due to the increasing and stringent functional requirements (larger capacity, longer distances, etc.) of modern day communication systems, higher antenna gains are generally needed. This higher gain implies larger antenna size and mass which are undesirable to many systems. Consequently, downsizing antenna technology becomes one of the most critical areas for research and development efforts. Techniques to reduce antenna size can be categorized and are briefly discussed.

Lightweight Solar Photovoltaic Blankets

NASA Technical Reports Server (NTRS)

Ceragioli, R.; Himmler, R.; Nath, P.; Vogeli, C.; Guha, S.

1995-01-01

Lightweight, flexible sheets containing arrays of stacked solar photovoltaic cells developed to supply electric power aboard spacecraft. Solar batteries satisfying stringent requirements for operation in outer space also adaptable to terrestrial environment. Attractive for use as long-lived, portable photovoltaic power sources. Cells based on amorphous silicon which offers potential for order-of-magnitude increases in power per unit weight, power per unit volume, and endurance in presence of ionizing radiation.

Low Impact Development for Industrial Areas

DTIC Science & Technology

2015-07-01

Stormwater program managers are faced with increasingly stringent stormwater discharge limits for heavy metals such as copper, zinc , nutrients, total...limits for heavy metals such as copper, zinc , nutrients, total suspended solids (TSS), oil and grease. These limits are required to reduce...U.S. EPA), state agencies, and local agencies set permit limits as part of the total mass daily loading regulatory framework. Copper, zinc , lead

National Strategy for Homeland Security

DTIC Science & Technology

2007-10-01

biometrics, including in passports and visas, has made it increasingly diffi- cult to counterfeit travel docu- ments, and we must encourage those... counterfeiting , altera- tion, and misuse of identifica- tion and travel documents, and to report lost and stolen passports in a timely manner. These efforts...in medicine , agriculture, and industry. We will stringently enforce our export control laws as a means of denying rogue actors – including

Comparison of CpG island methylator phenotype (CIMP) frequency in colon cancer using different probe- and gene-specific scoring alternatives on recommended multi-gene panels.

PubMed

Berg, Marianne; Hagland, Hanne R; Søreide, Kjetil

2014-01-01

In colorectal cancer a distinct subgroup of tumours demonstrate the CpG island methylator phenotype (CIMP). However, a consensus of how to score CIMP is not reached, and variation in definition may influence the reported CIMP prevalence in tumours. Thus, we sought to compare currently suggested definitions and cut-offs for methylation markers and how they influence CIMP classification in colon cancer. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), with subsequent fragment analysis, was used to investigate methylation of tumour samples. In total, 31 CpG sites, located in 8 different genes (RUNX3, MLH1, NEUROG1, CDKN2A, IGF2, CRABP1, SOCS1 and CACNA1G) were investigated in 64 distinct colon cancers and 2 colon cancer cell lines. The Ogino gene panel includes all 8 genes, in addition to the Weisenberger panel of which only 5 of the 8 genes included were investigated. In total, 18 alternative combinations of scoring of CIMP positivity on probe-, gene-, and panel-level were analysed and compared. For 47 samples (71%), the CIMP status was constant and independent of criteria used for scoring; 34 samples were constantly scored as CIMP negative, and 13 (20%) consistently scored as CIMP positive. Only four of 31 probes (13%) investigated showed no difference in the numbers of positive samples using the different cut-offs. Within the panels a trend was observed that increasing the gene-level stringency resulted in a larger difference in CIMP positive samples than increasing the probe-level stringency. A significant difference between positive samples using 'the most stringent' as compared to 'the least stringent' criteria (20% vs 46%, respectively; p<0.005) was demonstrated. A statistical significant variation in the frequency of CIMP depending on the cut-offs and genes included in a panel was found, with twice as many positives samples by least compared to most stringent definition used.

Best performing definition of accelerated knee osteoarthritis: data from the Osteoarthritis Initiative

PubMed Central

Driban, Jeffrey B.; Stout, Alina C.; Lo, Grace H.; Eaton, Charles B.; Price, Lori Lyn; Lu, Bing; Barbe, Mary F.; McAlindon, Timothy E.

2016-01-01

Background: We evaluated agreement among several definitions of accelerated knee osteoarthritis (AKOA) and construct validity by comparing their individual associations with injury, age, obesity, and knee pain. Methods: We selected knees from the Osteoarthritis Initiative that had no radiographic knee osteoarthritis [Kellgren–Lawrence (KL) 0 or 1] at baseline and had high-quality quantitative medial joint space width (JSW) measures on two or more consecutive visits (n = 1655 knees, 1143 participants). Quantitative medial JSW was based on a semi-automated method and was location specific (x = 0.25). We compared six definitions of AKOA: stringent JSW (averaged): average JSW loss greater than 1.05 mm/year over 4 years; stringent JSW (consistent): JSW loss greater than 1.05 mm/year for at least 2 years; lenient JSW (averaged): average JSW loss greater than 0.25 mm/year over 4 years; lenient JSW (consistent): JSW loss greater than 0.25 mm/year for at least 2 years; comprehensive KL based: progression from no radiographic osteoarthritis to advance-stage osteoarthritis (KL 3 or 4; development of definite osteophyte and joint space narrowing) within 4 years; and lenient KL based: an increase of at least two KL grades within 4 years. Results: Over 4 years the incidence rate of AKOA was 0.4%, 0.8%, 15.5%, 22.1%, 12.4%, and 7.2% based on the stringent JSW (averaged and consistent), lenient JSW (averaged and consistent), lenient KL-based definition, and comprehensive KL-based definition. All but one knee that met the stringent JSW definition also met the comprehensive KL-based definition. There was fair substantial agreement between the lenient JSW (averaged), lenient KL-based, and comprehensive KL-based definitions. A comprehensive KL-based definition led to larger effect sizes for injury, age, body mass index, and average pain over 4 years. Conclusions: A comprehensive KL-based definition of AKOA may be ideal because it represents a broader definition of joint deterioration compared with those focused on just joint space or osteophytes alone. PMID:27721902

33 CFR 154.1045 - Response plan development and evaluation criteria for facilities that handle, store, or transport...

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Reclassifications may be to— (i) A more stringent operating environment if the prevailing wave conditions exceed the significant wave height criteria during more than 35 percent of the year; or (ii) A less stringent operating environment if the prevailing wave conditions do not exceed the significant wave height criteria for the less...

Polybrominated diphenyl ether (PBDE) concentrations and resulting exposure in homes in California: relationships among passive air, surface wipe and dust concentrations, and temporal variability.

PubMed

Bennett, D H; Moran, R E; Wu, X May; Tulve, N S; Clifton, M S; Colón, M; Weathers, W; Sjödin, A; Jones, R; Hertz-Picciotto, I

2015-04-01

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam, electronics, and other home furnishings. A field study was conducted that enrolled 139 households from California, which has had more stringent flame retardant requirements than other countries and areas. The study collected passive air, floor and indoor window surface wipes, and dust samples (investigator collected using an HVS3 and vacuum cleaner) in each home. PentaBDE and BDE209 were detected in the majority of the dust samples and many floor wipe samples, but the detection in air and window wipe samples was relatively low. Concentrations of each PBDE congener in different indoor environmental media were moderately correlated, with correlation coefficients ranging between 0.42 and 0.68. Correlation coefficients with blood levels were up to 0.65 and varied between environmental media and age group. Both investigator-collected dust and floor wipes were correlated with serum levels for a wide range of congeners. These two sample types also had a relatively high fraction of samples with adequate mass for reliable quantification. In 42 homes, PBDE levels measured in the same environmental media in the same home 1 year apart were statistically correlated (correlation coefficients: 0.57-0.90), with the exception of BDE209 which was not well correlated longitudinally. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Managing conflicts of interest in clinical care: the "race to the middle" at U.S. medical schools.

PubMed

Chimonas, Susan; Evarts, Susanna D; Littlehale, Sarah K; Rothman, David J

2013-10-01

National recommendations specify how medical schools should manage clinical conflicts of interest (CCOIs), including gifts and payments to physicians from pharmaceutical companies. A 2008 study showed that few schools had policies in keeping with the recommendations. The authors conducted a follow-up study in 2011 to assess possible improvements. To obtain policies in 12 areas of CCOI, the authors searched the Web sites of all 133 medical schools existing in July 2011 and contacted schools that had no online policies. Policies were scored as no policy, permissive, moderate, or stringent, based on published recommendations; each school's scores were averaged to assess overall policy strength. Changes since 2008 were evaluated. The authors also collected information on schools' public/private status, hospital ownership/affiliation, and National Institutes of Health (NIH) funding to determine whether these characteristics were associated with differences in policy strength. Policies were obtained for a representative sample of 127 (95%) medical schools. The frequency of stringent policies increased from 2008 to 2011 in all CCOI areas, and medical schools' overall policy strength more than doubled. However, less than stringent policies remained the norm for all areas except ghostwriting. Greater NIH funding was associated with stronger policies in five areas and with higher overall policy strength. Schools have made great progress toward national standards, yet room for improvement remains: The data reveal not a race to the top but a shift from the bottom to the middle. Follow-up research should explore whether stronger policies emerge in the future.

Trends in Acute Nonvariceal Upper Gastrointestinal Bleeding in Dialysis Patients

PubMed Central

Yang, Ju-Yeh; Lee, Tsung-Chun; Montez-Rath, Maria E.; Paik, Jane; Chertow, Glenn M.; Desai, Manisha

2012-01-01

Impaired kidney function is a risk factor for upper gastrointestinal (GI) bleeding, an event associated with poor outcomes. The burden of upper GI bleeding and its effect on patients with ESRD are not well described. Using data from the US Renal Data System, we quantified the rates of occurrence of and associated 30-day mortality from acute, nonvariceal upper GI bleeding in patients undergoing dialysis; we used medical claims and previously validated algorithms where available. Overall, 948,345 patients contributed 2,296,323 patient-years for study. The occurrence rates for upper GI bleeding were 57 and 328 episodes per 1000 person-years according to stringent and lenient definitions of acute, nonvariceal upper GI bleeding, respectively. Unadjusted occurrence rates remained flat (stringent) or increased (lenient) from 1997 to 2008; after adjustment for sociodemographic characteristics and comorbid conditions, however, we found a significant decline for both definitions (linear approximation, 2.7% and 1.5% per year, respectively; P<0.001). In more recent years, patients had higher hematocrit levels before upper GI bleeding episodes and were more likely to receive blood transfusions during an episode. Overall 30-day mortality was 11.8%, which declined significantly over time (relative declines of 2.3% or 2.8% per year for the stringent and lenient definitions, respectively). In summary, despite declining trends worldwide, crude rates of acute, nonvariceal upper GI bleeding among patients undergoing dialysis have not decreased in the past 10 years. Although 30-day mortality related to upper GI bleeding declined, perhaps reflecting improvements in medical care, the burden on the ESRD population remains substantial. PMID:22266666

Evaluation of mailed pediatric buccal cytobrushes for use in a case-control study of birth defects.

PubMed

Gallagher, Margaret L; Sturchio, Cynthia; Smith, Ashley; Koontz, Deborah; Jenkins, Mary M; Honein, Margaret A; Rasmussen, Sonja A

2011-07-01

Buccal cell collection is a convenient DNA collection method; however, little attention has been given to the quality of DNA obtained from pediatric populations. The purpose of this study was to determine the effect of a modified cytobrush collection method on the yield and quality of infant buccal DNA collected as part of a population-based case-control study of birth defects. METHODS Cytobrushes were collected from infants, mothers, and fathers using a standard collection method in 1997 to 2003 and a modified protocol that allows air-drying of the cytobrushes after collection from 2003 to the present. Yield and quality of DNA from 1057 cytobrushes was assessed by quantitative PCR and short tandem repeat (STR) genotyping, respectively. RESULTS Air-dried cytobrushes from infants had higher median DNA yields (1300 ng) and STR completion rates (99.5%) than standard collection method cytobrushes (60 ng and 59.5%, respectively). A subset of DNA aliquots was genotyped for six single nucleotide polymorphisms (SNPs). Aliquots from both collection methods that passed the quality protocol (DNA concentration >1 ng/μl, and successful amplification of ≥1 STR) had high genotype completion rates (99-100%). The median DNA yield following whole genome amplification was more than twofold higher for air-dried than standard collection specimens (p < 0.001). CONCLUSION Yield and quality of buccal DNA collected from infants are improved by using a method that incorporates air-drying; however, DNA collected by both methods is suitable for genotyping if stringent quality control procedures are instituted. These findings may be helpful for future epidemiologic studies of birth defects and other adverse pediatric outcomes. Copyright © 2011 Wiley-Liss, Inc.

GeoMedStat: an integrated spatial surveillance system to track air pollution and associated healthcare events.

PubMed

Faruque, Fazlay S; Li, Hui; Williams, Worth B; Waller, Lance A; Brackin, Bruce T; Zhang, Lei; Grimes, Kim A; Finley, Richard W

2014-12-01

Air pollutants, such as particulate matter with a diameter ≤2.5 microns (PM2.5) and ozone (O3), are known to exacerbate asthma and other respiratory diseases. An integrated surveillance system that tracks such air pollutants and associated disease incidence can assist in risk assessment, healthcare preparedness and public awareness. However, the implementation of such an integrated environmental health surveillance system is a challenge due to the disparate sources of many types of data and the implementation becomes even more complicated for a spatial and real-time system due to lack of standardised technological components and data incompatibility. In addition, accessing and utilising health data that are considered as Protected Health Information (PHI) require maintaining stringent protocols, which have to be supported by the system. This paper aims to illustrate the development of a spatial surveillance system (GeoMedStat) that is capable of tracking daily environmental pollutants along with both daily and historical patient encounter data. It utilises satellite data and the groundmonitor data from the US National Aeronautics and Space Administration (NASA) and the US Environemental Protection Agenecy (EPA), rspectively as inputs estimating air pollutants and is linked to hospital information systems for accessing chief complaints and disease classification codes. The components, developmental methods, functionality of GeoMedStat and its use as a real-time environmental health surveillance system for asthma and other respiratory syndromes in connection with with PM2.5 and ozone are described. It is expected that the framework presented will serve as an example to others developing real-time spatial surveillance systems for pollutants and hospital visits.

Air quality improvements following implementation of Lisbon's Low Emission Zone

NASA Astrophysics Data System (ADS)

Ferreira, F.; Gomes, P.; Tente, H.; Carvalho, A. C.; Pereira, P.; Monjardino, J.

2015-12-01

Air pollution levels within Lisbon city limits have been exceeding the limit values established in European Union and national legislation since 2001, with the most problematic cases related to the levels of fine particles (PM10) and nitrogen dioxide (NO2), mainly originated by road traffic. With the objective of answering this public health issue, an Air Quality Action Plan was developed in 2006 and the respective Enforcement Plan was published in 2009. From the overall strategy, one of the major measures presented in this strategy was the creation of a Low Emission Zone (LEZ) in Lisbon, which has been operating since July 2011. Implemented at different stages it has progressively expanded its area, including more vehicle types and adopting more stringent requirements in terms of minimum emission standards (currently LEZ phase 2 with EURO 2 in the city center - zone 1 and EURO 1 in the rest of the LEZ area - zone 2). At the same time the road axis comprised of Marquês de Pombal square and Avenida da Liberdade was subjected to profound changes in its traffic circulation model, reducing road traffic volumes. The analysis of the air quality data before and after the LEZ phase 2 has shown positive evolution when comparing the period between 2011 (before measures) and 2013 (after measures). In 2013, there was a reduction in PM10 annual average concentration of 23% and NO2 annual average concentrations of 12%, compared with the year 2011. Although PM10 reductions were more significant inside the LEZ area, the same was not valid for NO2, suggesting that the implementation of these measures was not as effective in reducing NO2 levels as shown by results in other cities like Berlin and London. The results from road traffic characterization indicate a relevant effect on fleet renewal with an overall decrease in the relative weight of pre-EURO 2 vehicles in 2012/2013, compared with data from 2011. An important increase in the share of EURO 4 and EURO 5 vehicles was also observed. Our conclusions show that the level of ambition is relevant for the observed effects. Therefore, stricter restriction standards should be enforced in the future stages of the Lisbon LEZ in conjunction with a higher effort and investment on LEZ enforcement.

ASTP (SA-210) Launch vehicle operational flight trajectory. Part 3: Final documentation

NASA Technical Reports Server (NTRS)

Carter, A. B.; Klug, G. W.; Williams, N. W.

1975-01-01

Trajectory data are presented for a nominal and two launch window trajectory simulations. These trajectories are designed to insert a manned Apollo spacecraft into a 150/167 km. (81/90 n. mi.) earth orbit inclined at 51.78 degrees for rendezvous with a Soyuz spacecraft, which will be orbiting at approximately 225 km. (121.5 n. mi.). The launch window allocation defined for this launch is 500 pounds of S-IVB stage propellant. The launch window opening trajectory simulation depicts the earliest launch time deviation from a planar flight launch which conforms to this constraint. The launch window closing trajectory simulation was developed for the more stringent Air Force Eastern Test Range (AFETR) flight azimuth restriction of 37.4 degrees east-of-north. These trajectories enclose a 12.09 minute launch window, pertinent features of which are provided in a tabulation. Planar flight data are included for mid-window reference.

Aircraft gas turbine low-power emissions reduction technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Gleason, C. C.; Bahr, D. W.

1978-01-01

Advanced aircraft turbine engine combustor technology was used to reduce low-power emissions of carbon monoxide and unburned hydrocarbons to levels significantly lower than those which were achieved with current technology. Three combustor design concepts, which were designated as the hot-wall liner concept, the recuperative-cooled liner concept, and the catalyst converter concept, were evaluated in a series of CF6-50 engine size 40 degree-sector combustor rig tests. Twenty-one configurations were tested at operating conditions spanning the design condition which was an inlet temperature and pressure of 422 K and 304 kPa, a reference velocity of 23 m/s and a fuel-air-ration of 10.5 g/kg. At the design condition typical of aircraft turbine engine ground idle operation, the best configurations of all three concepts met the stringent emission goals which were 10, 1, and 4 g/kg for CO, HC, and Nox, respectively.

KSC-06pd0783

NASA Image and Video Library

2006-04-28

KENNEDY SPACE CENTER, FLA. - Dwayne Light (left), director of Florida Operations, Astrotech, assists Jim Adams, deputy project manager for NASA's Solar Terrestrial Relations Observatory (STEREO), Goddard Space Flight Center, as he cuts the ribbon to officially open the new class 10,000 clean-room enclosure at Astrotech, a payload processing facility near Kennedy Space Center. This clean-room enclosure, within the high bay at Astrotech, meets the additional stringent cleanliness requirements necessary for processing STEREO for launch. The enclosure was designed and constructed by Astrotech to meet the spacecraft requirements provided by STEREO project management at NASA's Goddard Space Flight Center, Greenbelt, Md. STEREO consists of two spacecraft whose mission is the first to take measurements of the sun and solar wind in 3-D. Launch aboard a Boeing Delta II rocket from Launch Complex 17 on Cape Canaveral Air Force Station is scheduled to occur over the summer. Photo credit: NASA/Dimitri Gerondidakis

KSC-06pd0782

NASA Image and Video Library

2006-04-28

KENNEDY SPACE CENTER, FLA. - Jim Adams (right), deputy project manager for NASA's Solar Terrestrial Relations Observatory (STEREO), Goddard Space Flight Center, presents a certificate of appreciation to Dwayne Light, director of Florida Operations, Astrotech, a payload processing facility near Kennedy Space Center. The occasion was the ribbon-cutting for a clean-room enclosure, within the high bay at Astrotech. The enclosure meets the additional stringent cleanliness requirements necessary for processing STEREO for launch. It was designed and constructed by Astrotech to meet the spacecraft requirements provided by STEREO project management at NASA's Goddard Space Flight Center, Greenbelt, Md. STEREO consists of two spacecraft whose mission is the first to take measurements of the sun and solar wind in 3-D. Launch aboard a Boeing Delta II rocket from Launch Complex 17 on Cape Canaveral Air Force Station is scheduled to occur over the summer. Photo credit: NASA/Dimitri Gerondidakis

Application of ozone to eliminate tertiary treatment of wastewater used for industrial cooling

NASA Astrophysics Data System (ADS)

Merrill, D. T.; Parker, D. S.

1982-02-01

The beneficial performance of ozone (biofouling, corrosion, and chemical scaling control), when used as the sole source of cooling water treatment for air conditioning systems, could be obtained at higher cooling water temperatures typical of industrial cooling with secondary municipal effluent (SME) used as the cooling medium was investigated. A pilot cooling system was constructed and a 6 month experimental study initiated to determine process limits, mechanisms of scaling inhibition by ozone, and to evaluate factors influencing technical/economic feasibility. It was found that, while ozone use adequately controlled corrosion and biofouling, chemical scaling could not be prevented at conditions necessary for significant economic justification. Calculations indicate that the makeup waters (SME) used will become saturated with respect to calcium phosphate at less than 2 cycles of concentration, hence, a scaling potential exists at conditions less stringent than those used in the present study.

On the CCN (de)activation nonlinearities

NASA Astrophysics Data System (ADS)

Arabas, Sylwester; Shima, Shin-ichiro

2017-09-01

We take into consideration the evolution of particle size in a monodisperse aerosol population during activation and deactivation of cloud condensation nuclei (CCN). Our analysis reveals that the system undergoes a saddle-node bifurcation and a cusp catastrophe. The control parameters chosen for the analysis are the relative humidity and the particle concentration. An analytical estimate of the activation timescale is derived through estimation of the time spent in the saddle-node bifurcation bottleneck. Numerical integration of the system coupled with a simple air-parcel cloud model portrays two types of activation/deactivation hystereses: one associated with the kinetic limitations on droplet growth when the system is far from equilibrium, and one occurring close to equilibrium and associated with the cusp catastrophe. We discuss the presented analyses in context of the development of particle-based models of aerosol-cloud interactions in which activation and deactivation impose stringent time-resolution constraints on numerical integration.

Sources and Chemical Composition of Atmospheric Fine Particles in Rabigh, Saudi Arabia

NASA Astrophysics Data System (ADS)

Nayebare, S. R.; Aburizaiza, O. S.; Siddique, A.; Hussain, M. M.; Zeb, J.; Khwaja, H. A.

2014-12-01

Air pollution research in Saudi Arabia and the whole of Middle East is at its inception, making air pollution in the region a significant problem. This study presents the first detailed data on fine particulate matter (PM2.5) concentrations of Black Carbon (BC), ions, and trace metals at Rabigh, Saudi Arabia, and assesses their sources. Results showed several characteristic aspects of air pollution at Rabigh. Daily levels of PM2.5 and BC showed significant temporal variability ranging from 12.2 - 75.9 µg/m3 and 0.39 - 1.31 µg/m3, respectively. More than 90% of the time, the daily PM2.5 exceeded the 24 h WHO guideline of 20 µg/m3. Sulfate, NO3-, and NH4+ dominated the identifiable components. Trace metals with significantly higher concentrations included Si, S, Ca, Al, Fe, Na, Cl, Mg, K, and Ti, with average concentrations of 3.1, 2.2, 1.6, 1.2, 1.1, 0.7, 0.7, 0.5, 0.4 and 0.1 µg/m3, respectively. Based on the Air Quality Index (AQI), there were 44% days of moderate air quality, 33% days of unhealthy air quality for sensitive groups, and 23% days of unhealthy air quality throughout the study period. Two categories of aerosol trace metal sources were defined: anthropogenic (S, V, Cr, Ni, Cu, Zn, Br, Cd, Sb, and Pb) and naturally derived elements (Si, Al, and Fe). The extent of anthropogenic contribution was estimated by the degree of enrichment of these elements compared to the crustal composition. Soil resuspension and/or mobilization is an important source of "natural" elements, while "anthropogenic" elements originate primarily from fossil fuel combustion and industries. Ni and V correlated strongly pointing to combustion of heavy fuel oil as the likely source. A positive matrix factorization (PMF) was used to obtain information about possible sources. Our study highlights the need for stringent laws on PM2.5 emission control to protect human health and the environment.

Review of electrotechnologies used in the disinfection of water and wastewater. Final report

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

VandeVenter, L.W.

This report provides an overview of the disinfection practices used in water and wastewater treatment. Chlorine historically has been the disinfectant of choice for both water and wastewater, but with increased research and more stringent regulations, other disinfectants, namely ozone and ultraviolet irradiation, are being considered. The report summarizes the present and future applications of these technologies and defines possible opportunities for Demand- Side Management (DSM).

Review of electrotechnologies used in the disinfection of water and wastewater

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

VandeVenter, L.W.

This report provides an overview of the disinfection practices used in water and wastewater treatment. Chlorine historically has been the disinfectant of choice for both water and wastewater, but with increased research and more stringent regulations, other disinfectants, namely ozone and ultraviolet irradiation, are being considered. The report summarizes the present and future applications of these technologies and defines possible opportunities for Demand- Side Management (DSM).

The large-scale structure of the asteroid belt

NASA Technical Reports Server (NTRS)

Zellner, B.; Thirunagari, A.; Bender, D.

1985-01-01

The distributions of 2888 numbered minor planets over orbital inclination, eccentricity, and semimajor axis are examined, and 19 zones believed to adequately isolate the selection biases in survey programs of the physical properties of minor planets are defined. Six numbered asteroids have exceptional orbits and fall into no zone. Attention is called to rather sharp upper limits, which become increasingly stringent at larger heliocentric distances, on orbital inclinations and eccentricity.

Role of the standard deviation in the estimation of benchmark doses with continuous data.

PubMed

Gaylor, David W; Slikker, William

2004-12-01

For continuous data, risk is defined here as the proportion of animals with values above a large percentile, e.g., the 99th percentile or below the 1st percentile, for the distribution of values among control animals. It is known that reducing the standard deviation of measurements through improved experimental techniques will result in less stringent (higher) doses for the lower confidence limit on the benchmark dose that is estimated to produce a specified risk of animals with abnormal levels for a biological effect. Thus, a somewhat larger (less stringent) lower confidence limit is obtained that may be used as a point of departure for low-dose risk assessment. It is shown in this article that it is important for the benchmark dose to be based primarily on the standard deviation among animals, s(a), apart from the standard deviation of measurement errors, s(m), within animals. If the benchmark dose is incorrectly based on the overall standard deviation among average values for animals, which includes measurement error variation, the benchmark dose will be overestimated and the risk will be underestimated. The bias increases as s(m) increases relative to s(a). The bias is relatively small if s(m) is less than one-third of s(a), a condition achieved in most experimental designs.

Dual Regulation of Bacillus subtilis kinB Gene Encoding a Sporulation Trigger by SinR through Transcription Repression and Positive Stringent Transcription Control.

PubMed

Fujita, Yasutaro; Ogura, Mitsuo; Nii, Satomi; Hirooka, Kazutake

2017-01-01

It is known that transcription of kinB encoding a trigger for Bacillus subtilis sporulation is under repression by SinR, a master repressor of biofilm formation, and under positive stringent transcription control depending on the adenine species at the transcription initiation nucleotide (nt). Deletion and base substitution analyses of the kinB promoter (P kinB ) region using lacZ fusions indicated that either a 5-nt deletion (Δ5, nt -61/-57, +1 is the transcription initiation nt) or the substitution of G at nt -45 with A (G-45A) relieved kinB repression. Thus, we found a pair of SinR-binding consensus sequences (GTTCTYT; Y is T or C) in an inverted orientation (SinR-1) between nt -57/-42, which is most likely a SinR-binding site for kinB repression. This relief from SinR repression likely requires SinI, an antagonist of SinR. Surprisingly, we found that SinR is essential for positive stringent transcription control of P kinB . Electrophoretic mobility shift assay (EMSA) analysis indicated that SinR bound not only to SinR-1 but also to SinR-2 (nt -29/-8) consisting of another pair of SinR consensus sequences in a tandem repeat arrangement; the two sequences partially overlap the '-35' and '-10' regions of P kinB . Introduction of base substitutions (T-27C C-26T) in the upstream consensus sequence of SinR-2 affected positive stringent transcription control of P kinB , suggesting that SinR binding to SinR-2 likely causes this positive control. EMSA also implied that RNA polymerase and SinR are possibly bound together to SinR-2 to form a transcription initiation complex for kinB transcription. Thus, it was suggested in this work that derepression of kinB from SinR repression by SinI induced by Spo0A∼P and occurrence of SinR-dependent positive stringent transcription control of kinB might induce effective sporulation cooperatively, implying an intimate interplay by stringent response, sporulation, and biofilm formation.

High-energy neutrinos from multibody decaying dark matter

NASA Astrophysics Data System (ADS)

Hiroshima, Nagisa; Kitano, Ryuichiro; Kohri, Kazunori; Murase, Kohta

2018-01-01

Since the report of the PeV-TeV neutrinos by the IceCube Collaboration, various particle physics models have been proposed to explain the neutrino spectrum by dark matter particles decaying into neutrinos and other standard model particles. In such scenarios, simultaneous γ -ray emission is commonly expected. Therefore, multimessenger connections are generally important for the indirect searches of dark matters. The recent development of γ -ray astronomy puts stringent constraints on the properties of dark matter, especially by observations with the Fermi γ -ray satellite in the last several years. Motivated by the lack of γ -ray as well as the shape of the neutrino spectrum observed by IceCube, we discuss a scenario in which the DM is a PeV scale particle which couples strongly to other invisible particles and its decay products do not contain a charged particle. As an example to realize such possibilities, we consider a model of fermionic dark matter that decays into a neutrino and many invisible fermions. The dark matter decay is secluded in the sense that the emitted products are mostly neutrinos and dark fermions. One remarkable feature of this model is the resulting broadband neutrino spectra around the energy scale of the dark matter. We apply this model to multi-PeV dark matter, and discuss possible observable consequences in light of the IceCube data. In particular, this model could account for the large flux at medium energies of ˜10 - 100 TeV , possibly as well as the second peak at PeV, without violating the stringent γ -ray constraints from Fermi and air-shower experiments such as CASA-MIA.

On the development of a methodology for extensive in-situ and continuous atmospheric CO2 monitoring

NASA Astrophysics Data System (ADS)

Wang, K.; Chang, S.; Jhang, T.

2010-12-01

Carbon dioxide is recognized as the dominating greenhouse gas contributing to anthropogenic global warming. Stringent controls on carbon dioxide emissions are viewed as necessary steps in controlling atmospheric carbon dioxide concentrations. From the view point of policy making, regulation of carbon dioxide emissions and its monitoring are keys to the success of stringent controls on carbon dioxide emissions. Especially, extensive atmospheric CO2 monitoring is a crucial step to ensure that CO2 emission control strategies are closely followed. In this work we develop a methodology that enables reliable and accurate in-situ and continuous atmospheric CO2 monitoring for policy making. The methodology comprises the use of gas filter correlation (GFC) instrument for in-situ CO2 monitoring, the use of CO2 working standards accompanying the continuous measurements, and the use of NOAA WMO CO2 standard gases for calibrating the working standards. The use of GFC instruments enables 1-second data sampling frequency with the interference of water vapor removed from added dryer. The CO2 measurements are conducted in the following timed and cycled manner: zero CO2 measurement, two standard CO2 gases measurements, and ambient air measurements. The standard CO2 gases are calibrated again NOAA WMO CO2 standards. The methodology is used in indoor CO2 measurements in a commercial office (about 120 people working inside), ambient CO2 measurements, and installed in a fleet of in-service commercial cargo ships for monitoring CO2 over global marine boundary layer. These measurements demonstrate our method is reliable, accurate, and traceable to NOAA WMO CO2 standards. The portability of the instrument and the working standards make the method readily applied for large-scale and extensive CO2 measurements.

Global Rsh-dependent transcription profile of Brucella suis during stringent response unravels adaptation to nutrient starvation and cross-talk with other stress responses

PubMed Central

2013-01-01

Background In the intracellular pathogen Brucella spp., the activation of the stringent response, a global regulatory network providing rapid adaptation to growth-affecting stress conditions such as nutrient deficiency, is essential for replication in the host. A single, bi-functional enzyme Rsh catalyzes synthesis and hydrolysis of the alarmone (p)ppGpp, responsible for differential gene expression under stringent conditions. Results cDNA microarray analysis allowed characterization of the transcriptional profiles of the B. suis 1330 wild-type and Δrsh mutant in a minimal medium, partially mimicking the nutrient-poor intramacrophagic environment. A total of 379 genes (11.6% of the genome) were differentially expressed in a rsh-dependent manner, of which 198 were up-, and 181 were down-regulated. The pleiotropic character of the response was confirmed, as the genes encoded an important number of transcriptional regulators, cell envelope proteins, stress factors, transport systems, and energy metabolism proteins. Virulence genes such as narG and sodC, respectively encoding respiratory nitrate reductase and superoxide dismutase, were under the positive control of (p)ppGpp, as well as expression of the cbb3-type cytochrome c oxidase, essential for chronic murine infection. Methionine was the only amino acid whose biosynthesis was absolutely dependent on stringent response in B. suis. Conclusions The study illustrated the complexity of the processes involved in adaptation to nutrient starvation, and contributed to a better understanding of the correlation between stringent response and Brucella virulence. Most interestingly, it clearly indicated (p)ppGpp-dependent cross-talk between at least three stress responses playing a central role in Brucella adaptation to the host: nutrient, oxidative, and low-oxygen stress. PMID:23834488

Microbiological assessment of indoor air of a teaching hospital in Nigeria.

PubMed

Awosika, S A; Olajubu, F A; Amusa, N A

2012-06-01

To investigate the quality of indoor air of different wards and units of Olabisi Onabanjo University Teaching Hospital, Sagamu, to ascertain their contribution to infection rate in the hospital. The microbial quality of indoor air of nine wards/units of Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria was conducted. Sedimentation technique using open Petri-dishes containing different culture media was employed and samplings were done twice daily, one in the morning shortly after cleaning and before influx of people/patients into the wards/units and the other in the evening when a lot of activities would have taken place in these wards. Isolates were identified according to standard methods. Results showed that there was a statistically significant difference (χ(2) = 6.016 7) in the bacteria population of the different sampling time whereas it was not so for fungi population (χ(2) = 0.285 7). Male medical ward (MMW) and male surgical general (MSG) recorded the highest bacterial and fungal growth while the operating theatre (OT) was almost free of microbial burden. The bacteria isolates were Staphylococcus aureus, Klebsiella sp., Bacillus cereus, Bacillus subtilis, Streptococcus pyogenes and Serratia marscences while the fungi isolates included Aspergillus flavus, Penicillium sp., Fusarium sp., Candida albicans and Alternaria sp. Staphylococcus aureus was the predominantly isolated bacterium while Penicillium sp. was the most isolated fungus. Though most of the microbial isolates were potential and or opportunistic pathogens, there was no correlation between the isolates in this study and the surveillance report of nosocomial infection during the period of study, hence the contribution of the indoor air cannot be established. From the reduction noticed in the morning samples, stringent measures such as proper disinfection and regular cleaning, restriction of patient relatives' movement in and out of the wards/units need to be enforced so as to improve the quality of indoor air of our hospital wards/units.

Bay breeze climatology at two sites along the Chesapeake bay from 1986-2010: Implications for surface ozone.

PubMed

Stauffer, Ryan M; Thompson, Anne M

Hourly surface meteorological measurements were coupled with surface ozone (O 3 ) mixing ratio measurements at Hampton, Virginia and Baltimore, Maryland, two sites along the Chesapeake Bay in the Mid-Atlantic United States, to examine the behavior of surface O 3 during bay breeze events and quantify the impact of the bay breeze on local O 3 pollution. Analyses were performed for the months of May through September for the years 1986 to 2010. The years were split into three groups to account for increasingly stringent environmental regulations that reduced regional emissions of nitrogen oxides (NO x ): 1986-1994, 1995-2002, and 2003-2010. Each day in the 25-year record was marked either as a bay breeze day, a non-bay breeze day, or a rainy/cloudy day based on the meteorological data. Mean eight hour (8-h) averaged surface O 3 values during bay breeze events were 3 to 5 parts per billion by volume (ppbv) higher at Hampton and Baltimore than on non-bay breeze days in all year periods. Anomalies from mean surface O 3 were highest in the afternoon at both sites during bay breeze days in the 2003-2010 study period. In conjunction with an overall lowering of baseline O 3 after the 1995-2002 period, the percentage of total exceedances of the Environmental Protection Agency (EPA) 75 ppbv 8-h O 3 standard that occurred on bay breeze days increased at Hampton for 2003-2010, while remaining steady at Baltimore. These results suggest that bay breeze circulations are becoming more important to causing exceedance events at particular sites in the region, and support the hypothesis of Martins et al. (2012) that highly localized meteorology increasingly drives air quality events at Hampton.

Development of an 8000 bps voice codec for AvSat

NASA Technical Reports Server (NTRS)

Clark, Joseph F.

1988-01-01

Air-mobile speech communication applications share robustness and noise immunity requirements with other mobile applications. The quality requirements are stringent, especially in the cockpit where air safety is involved. Based on these considerations, a decision was made to test an intermediate data rate such as 8.0 and 9.6 kb/s as proven technologies. A number of vocoders and codec technologies were investigated at rates ranging from 2.4 kb/s up to and including 9.6 kb/s. The proven vocoders operating at 2.4 and 4.8 kb/s lacked the noise immunity or the robustness to operate reliably in a cabin noise environment. One very attractive alternative approach was Spectrally Encoded Residual Excited LPC (SE-RELP) which is used in a multi-rate voice processor (MRP) developed at the Naval Research Lab (NRL). The MRP uses SE-RELP at rates of 9.6 and 16 kb/s. The 9.6 kb/s rate can be lowered to 8.0 kb/s without loss of information by modifying the frame. An 8.0 kb/s vocoder was developed using SE-RELP as a demonstrator and testbed. This demonstrator is implemented in real time using two Compaq 2 portable computers, each equipped with an ARIEL DSP016 Data Acquisition Processor.

Is ionizing radiation regulated more stringently than chemical carcinogens

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

Travis, C.C.; Pack, S.R.; Hattemer-Frey, H.A.

1989-04-01

It is widely believed that United States government agencies regulate exposure to ionizing radiation more stringently than exposure to chemical carcinogens. It is difficult to verify this perception, however, because chemical carcinogens and ionizing radiation are regulated using vastly different strategies. Chemical carcinogens are generally regulated individually. Regulators consider the risk of exposure to one chemical rather than the cumulative radiation exposure from all sources. Moreover, standards for chemical carcinogens are generally set in terms of quantities released or resultant environmental concentrations, while standards for ionizing radiation are set in terms of dose to the human body. Since chemicals andmore » ionizing radiation cannot be compared on the basis of equal dose to the exposed individual, standards regulating chemicals and ionizing radiation cannot be compared directly. It is feasible, however, to compare the two sets of standards on the basis of equal risk to the exposed individual, assuming that standards for chemicals and ionizing radiation are equivalent if estimated risk levels are equitable. This paper compares risk levels associated with current standards for ionizing radiation and chemical carcinogens. The authors do not attempt to determine whether either type of risk is regulated too stringently or not stringently enough but endeavor only to ascertain if ionizing radiation is actually regulated more strictly than chemical carcinogens.« less

Orchestration of DNA Damage Checkpoint Dynamics across the Human Cell Cycle.

PubMed

Chao, Hui Xiao; Poovey, Cere E; Privette, Ashley A; Grant, Gavin D; Chao, Hui Yan; Cook, Jeanette G; Purvis, Jeremy E

2017-11-22

Although molecular mechanisms that prompt cell-cycle arrest in response to DNA damage have been elucidated, the systems-level properties of DNA damage checkpoints are not understood. Here, using time-lapse microscopy and simulations that model the cell cycle as a series of Poisson processes, we characterize DNA damage checkpoints in individual, asynchronously proliferating cells. We demonstrate that, within early G1 and G2, checkpoints are stringent: DNA damage triggers an abrupt, all-or-none cell-cycle arrest. The duration of this arrest correlates with the severity of DNA damage. After the cell passes commitment points within G1 and G2, checkpoint stringency is relaxed. By contrast, all of S phase is comparatively insensitive to DNA damage. This checkpoint is graded: instead of halting the cell cycle, increasing DNA damage leads to slower S phase progression. In sum, we show that a cell's response to DNA damage depends on its exact cell-cycle position and that checkpoints are phase-dependent, stringent or relaxed, and graded or all-or-none. Copyright © 2017 Elsevier Inc. All rights reserved.

Reduction in (pro-)inflammatory responses of lung cells exposed in vitro to diesel exhaust treated with a non-catalyzed diesel particle filter

NASA Astrophysics Data System (ADS)

Steiner, Sandro; Czerwinski, Jan; Comte, Pierre; Müller, Loretta L.; Heeb, Norbert V.; Mayer, Andreas; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2013-12-01

Increasingly stringent regulation of particulate matter emissions from diesel vehicles has led to the widespread use of diesel particle filters (DPFs), the effect of which on exhaust toxicity is so far poorly understood. We exposed a cellular model of the human respiratory epithelium at the air-liquid interface to non-catalyzed wall-flow DPF-filtered diesel exhaust and compared the resulting biological responses to the ones observed upon exposure to unfiltered exhaust. Filtered diesel exhaust acted highly oxidative, even though to a lesser extent than unfiltered exhaust (quantification of total reduced glutathione), and both exhaust types triggered comparable responses to oxidative stress (measurement of heme-oxygenase 1 (HMOX1) and superoxide-dismutase (SOD1) gene expression). Further, diesel exhaust filtration significantly reduced pro-inflammatory responses (measurement of tumor necrosis factor (TNF) and interleukin-8 (IL-8) gene expression and quantification of the secretion of their gene products TNF-α and IL-8). Because inflammatory processes are central to the onset of adverse respiratory health effects caused by diesel exhaust inhalation, our results imply that DPFs may make a valuable contribution to the detoxification of diesel vehicle emissions. The induction of significant oxidative stress by filtered diesel exhaust however, also implies that the non-particulate exhaust components also need to be considered for lung cell risk assessment.

Landfill leachate management in Istanbul: applications and alternatives.

PubMed

Calli, Baris; Mertoglu, Bulent; Inanc, Bulent

2005-05-01

Treatment alternatives for Istanbul, Komurcuoda Landfill (KL) leachate that is currently transported to the nearest central wastewater treatment plant were comprehensively investigated with laboratory scale experiments. As flow rate of leachate increases parallel to increment in landfilled solid waste, an individual treatment will be needed to reduce the transportation cost and pollution load on central treatment. However, if the leachate is separately treated and discharged to a brook, in that case more stringent discharge standards will be valid and therefore advanced processes in addition to conventional ones should be included. In laboratory scale experiments, the young landfill leachate having BOD5/COD ratio above 0.6 was successfully treated with efficiencies above 90% in upflow anaerobic reactors if pH is kept below free ammonia inhibition level. Subsequently, nitrification of anaerobically treated leachate was performed with rates of about 8.5 mg NH4+-Ng-1 VSS h-1 and efficiencies above 99% were provided with automated pH regulation by using sodium bicarbonate. Furthermore, denitrification rates as high as 8.1 mg NOx-N g-1VSS h-1 was obtained when carbon source was externally supplied. In addition to nitrification and denitrification, air stripping and struvite precipitation were also applied to remove ammonia in leachate and in average 94% and 98% efficiencies were achieved, respectively. Finally, in average 85% of biologically inert COD was successfully removed by using either ozone or Fenton's oxidation.

Sequential Extractions and Toxicity Potential of Trace Metals Absorbed into Airborne Particles in an Urban Atmosphere of Southwestern Nigeria

PubMed Central

Ediagbonya, Thompson Faraday

2018-01-01

The paper investigates the hypothesis that biotoxicities of trace metals depend not only on the concentration as expressed by the total amount, but also on their geochemical fractions and bioavailability. Airborne particles were collected using SKC Air Check XR 5000 high volume Sampler at a human breathing height of 1.5–2.0 meters, during the dry season months from November 2014 to March 2015 at different locations in Akure (7°10′N and 5°15′E). The geochemical-based sequential extractions were performed on the particles using a series of increasingly stringent solutions selected to extract metals (Cd, Cu, Cr, Ni, Pb, Zn, and Mn) into four operational geochemical phases—exchangeable, reducible, organic, and residual—and then quantified using an Atomic Absorption Spectrophotometer. The results showed metals concentration of order Pb > Cr > Cd > Zn > Ni > Cu > Mn. However, most metals in the samples exist in nonmobile fractions: exchangeable (6.43–16.2%), reducible (32.58–47.39%), organic (4.73–9.88%), and residual (18.28–27.53%). The pollution indices show ingestion as the leading route of metal exposure, with noncarcinogenic (HQ) and cancer risk (HI) for humans in the area being higher than 1.0 × 10−4, indicating a health threat. PMID:29686588

Air-pollution emission control in China: impacts on soil acidification recovery and constraints due to drought.

PubMed

Duan, Lei; Liu, Jing; Xin, Yan; Larssen, Thorjørn

2013-10-01

The Chinese government has established compulsory targets to reduce sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions by 8% and 10%, respectively, during 2010-2015. In this study, the effect of the policy was evaluated by predicting the recovery of acidified forest soil in Chongqing, an area severely impacted by acid rain in southwest China. Since precipitation has decreased significantly in this area in recent years, the impact of drought on soil acidification was also considered. A dynamic acidification model, MAGIC, was used to predict future trends in soil chemistry under different scenarios for deposition reduction as well as drought. We found that the current regulation of SO2 emission abatement did not significantly increase soil water pH values, the Ca2+ to Al3+ molar ratio (Ca/Al), or soil base saturation to the level of 2000 before 2050. NOx emission control would have less of an effect on acidification recovery, while emission reduction of particulate matter could offset the benefits of SO2 reduction by greatly decreasing the deposition of base cations, particularly Ca(2+). Continuous droughts in the future might also delay acidification recovery. Therefore, more stringent SO2 emission control should be implemented to facilitate the recovery of seriously acidified areas in China. © 2013 Elsevier B.V. All rights reserved.

Solar Pumped Lasers and Their Applications

NASA Technical Reports Server (NTRS)

Lee, Ja H.

1991-01-01

Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

Microbial removal of alkanes from dilute gaseous waste streams: kinetics and mass transfer considerations.

PubMed

Barton, J W; Klasson, K T; Koran, L J; Davison, B H

1997-01-01

Treatment of dilute gaseous hydrocarbon waste streams remains a current need for many industries, particularly as increasingly stringent environmental regulations and oversight force emission reduction. Biofiltration systems hold promise for providing low-cost alternatives to more traditional, energy-intensive treatment methods such as incineration and adsorption. Elucidation of engineering principles governing the behavior of such systems, including mass transfer limitations, will broaden their applicability. Our processes exploit a microbial consortium to treat a mixture of 0.5% n-pentane and 0.5% isobutane in air. Since hydrocarbon gases are sparingly soluble in water, good mixing and high surface area between the gas and liquid phases are essential for biodegradation to be effective. One liquid-continuous columnar bioreactor was operated for more than 30 months with continued degradation of n-pentane and isobutane as sole carbon and energy sources. The maximum degradation rate observed in this gas-recycle system was 2 g of volatile organic compounds (VOC)/(m3.h). A trickle-bed bioreactor was operated continuously for over 24 months to provide a higher surface area (using a structured packing) with increased rates. Degradation rates consistently achieved were approximately 50 g of VOC/(m3.h) via single pass in this gas-continuous columnar system. Effective mass transfer coefficients comparable to literature values were also measured for this reactor; these values were substantially higher than those found in the gas-recycle reactor. Control of biomass levels was implemented by limiting the level of available nitrogen in the recirculating aqueous media, enabling long-term stability of reactor performance.

Evolutionary stability concepts in a stochastic environment

NASA Astrophysics Data System (ADS)

Zheng, Xiu-Deng; Li, Cong; Lessard, Sabin; Tao, Yi

2017-09-01

Over the past 30 years, evolutionary game theory and the concept of an evolutionarily stable strategy have been not only extensively developed and successfully applied to explain the evolution of animal behaviors, but also widely used in economics and social sciences. Nonetheless, the stochastic dynamical properties of evolutionary games in randomly fluctuating environments are still unclear. In this study, we investigate conditions for stochastic local stability of fixation states and constant interior equilibria in a two-phenotype model with random payoffs following pairwise interactions. Based on this model, we develop the concepts of stochastic evolutionary stability (SES) and stochastic convergence stability (SCS). We show that the condition for a pure strategy to be SES and SCS is more stringent than in a constant environment, while the condition for a constant mixed strategy to be SES is less stringent than the condition to be SCS, which is less stringent than the condition in a constant environment.

Assessment of vehicle emission programs in China during 1998-2013: Achievement, challenges and implications.

PubMed

Wu, Xiaomeng; Wu, Ye; Zhang, Shaojun; Liu, Huan; Fu, Lixin; Hao, Jiming

2016-07-01

China has been embracing rapid motorization since the 1990s, and vehicles have become one of the major sources of air pollution problems. Since the late 1990s, thanks to the international experience, China has adopted comprehensive control measures to mitigate vehicle emissions. This study employs a local emission model (EMBEV) to assess China's first fifteen-year (1998-2013) efforts in controlling vehicles emissions. Our results show that China's total annual vehicle emissions in 2013 were 4.16 million tons (Mt) of HC, 27.4 Mt of CO, 7.72 Mt of NOX, and 0.37 Mt of PM2.5, respectively. Although vehicle emissions are substantially reduced relative to the without control scenarios, we still observe significantly higher emission density in East China than in developed countries with longer histories of vehicle emission control. This study further informs China's policy-makers of the prominent challenges to control vehicle emissions in the future. First, unlike other major air pollutants, total NOX emissions have rapidly increased due to a surge of diesel trucks and the postponed China IV standard nationwide. Simultaneous implementation of fuel quality improvements and vehicle-engine emission standards will be of great importance to alleviate NOX emissions for diesel fleets. Second, the enforcement of increasingly stringent standards should include strict oversight of type-approval conformity, in-use complacence and durability, which would help reduce gross emitters of PM2.5 that are considerable among in-use diesel fleets at the present. Third, this study reveals higher HC emissions than previous results and indicates evaporative emissions may have been underestimated. Considering that China's overall vehicle ownership is far from saturation, persistent efforts are required through economic tools, traffic management and emissions regulations to lower vehicle-use intensity and limit both exhaust and evaporative emissions. Furthermore, in light of the complex technology for emerging new energy vehicles, their real-world emissions need to be adequately evaluated before massive promotion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Why advanced computing? The key to space-based operations

NASA Astrophysics Data System (ADS)

Phister, Paul W., Jr.; Plonisch, Igor; Mineo, Jack

2000-11-01

The 'what is the requirement?' aspect of advanced computing and how it relates to and supports Air Force space-based operations is a key issue. In support of the Air Force Space Command's five major mission areas (space control, force enhancement, force applications, space support and mission support), two-fifths of the requirements have associated stringent computing/size implications. The Air Force Research Laboratory's 'migration to space' concept will eventually shift Science and Technology (S&T) dollars from predominantly airborne systems to airborne-and-space related S&T areas. One challenging 'space' area is in the development of sophisticated on-board computing processes for the next generation smaller, cheaper satellite systems. These new space systems (called microsats or nanosats) could be as small as a softball, yet perform functions that are currently being done by large, vulnerable ground-based assets. The Joint Battlespace Infosphere (JBI) concept will be used to manage the overall process of space applications coupled with advancements in computing. The JBI can be defined as a globally interoperable information 'space' which aggregates, integrates, fuses, and intelligently disseminates all relevant battlespace knowledge to support effective decision-making at all echelons of a Joint Task Force (JTF). This paper explores a single theme -- on-board processing is the best avenue to take advantage of advancements in high-performance computing, high-density memories, communications, and re-programmable architecture technologies. The goal is to break away from 'no changes after launch' design to a more flexible design environment that can take advantage of changing space requirements and needs while the space vehicle is 'on orbit.'

Stringent homology-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions.

PubMed

Zhou, Hufeng; Gao, Shangzhi; Nguyen, Nam Ninh; Fan, Mengyuan; Jin, Jingjing; Liu, Bing; Zhao, Liang; Xiong, Geng; Tan, Min; Li, Shijun; Wong, Limsoon

2014-04-08

H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are essential for understanding the infection mechanism of the formidable pathogen M. tuberculosis H37Rv. Computational prediction is an important strategy to fill the gap in experimental H. sapiens-M. tuberculosis H37Rv PPI data. Homology-based prediction is frequently used in predicting both intra-species and inter-species PPIs. However, some limitations are not properly resolved in several published works that predict eukaryote-prokaryote inter-species PPIs using intra-species template PPIs. We develop a stringent homology-based prediction approach by taking into account (i) differences between eukaryotic and prokaryotic proteins and (ii) differences between inter-species and intra-species PPI interfaces. We compare our stringent homology-based approach to a conventional homology-based approach for predicting host-pathogen PPIs, based on cellular compartment distribution analysis, disease gene list enrichment analysis, pathway enrichment analysis and functional category enrichment analysis. These analyses support the validity of our prediction result, and clearly show that our approach has better performance in predicting H. sapiens-M. tuberculosis H37Rv PPIs. Using our stringent homology-based approach, we have predicted a set of highly plausible H. sapiens-M. tuberculosis H37Rv PPIs which might be useful for many of related studies. Based on our analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent homology-based approach, we have discovered several interesting properties which are reported here for the first time. We find that both host proteins and pathogen proteins involved in the host-pathogen PPIs tend to be hubs in their own intra-species PPI network. Also, both host and pathogen proteins involved in host-pathogen PPIs tend to have longer primary sequence, tend to have more domains, tend to be more hydrophilic, etc. And the protein domains from both host and pathogen proteins involved in host-pathogen PPIs tend to have lower charge, and tend to be more hydrophilic. Our stringent homology-based prediction approach provides a better strategy in predicting PPIs between eukaryotic hosts and prokaryotic pathogens than a conventional homology-based approach. The properties we have observed from the predicted H. sapiens-M. tuberculosis H37Rv PPI network are useful for understanding inter-species host-pathogen PPI networks and provide novel insights for host-pathogen interaction studies.

Acid rain recovery may help to mitigate the impacts of climate change on thermally sensitive fish in lakes across eastern North America.

PubMed

Warren, Dana R; Kraft, Clifford E; Josephson, Daniel C; Driscoll, Charles T

2017-06-01

From the 1970s to 1990s, more stringent air quality regulations were implemented across North America and Europe to reduce chemical emissions that contribute to acid rain. Surface water pH slowly increased during the following decades, but biological recovery lagged behind chemical recovery. Fortunately, this situation is changing. In the past few years, northeastern US fish populations have begun to recover in lakes that were historically incapable of sustaining wild fish due to acidic conditions. As lake ecosystems across the eastern United States recover from acid deposition, the stress to the most susceptible populations of native coldwater fish appears to be shifting from acidification effects to thermal impacts associated with changing climate. Extreme summer temperature events - which are expected to occur with increasing frequency in the coming century - can stress and ultimately kill native coldwater fish in lakes where thermal stratification is absent or highly limited. Based on data from northeastern North America, we argue that recovery from acid deposition has the potential to improve the resilience of coldwater fish populations in some lakes to impacts of climate change. This will occur as the amount of dissolved organic carbon (DOC) in the water increases with increasing lake pH. Increased DOC will reduce water clarity and lead to shallower and more persistent lake thermoclines that can provide larger areas of coldwater thermal refuge habitat. Recovery from acidification will not eliminate the threat of climate change to coldwater fish, but secondary effects of acid recovery may improve the resistance of coldwater fish populations in lakes to the effects of elevated summer temperatures in historically acidified ecosystems. This analysis highlights the importance of considering the legacy of past ecosystem impacts and how recovery or persistence of those effects may interact with climate change impacts on biota in the coming decades. © 2016 John Wiley & Sons Ltd.

Irradiation of northwest agricultural products

NASA Astrophysics Data System (ADS)

Eakin, D. E.; Tingey, G. I.

1985-02-01

Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect ocntrol procedures are developed and followed. Due to the recognized potential benefits of irradiation, this program was conducted to evaluate the benefits of using irradiation on Northwest agricultural products. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

Stringent and reproducible tetracycline-regulated transgene expression by site-specific insertion at chromosomal loci with pre-characterised induction characteristics

PubMed Central

Brough, Rachel; Papanastasiou, Antigoni M; Porter, Andrew CG

2007-01-01

Background The ability to regulate transgene expression has many applications, mostly concerning the analysis of gene function. Desirable induction characteristics, such as low un-induced expression, high induced expression and limited cellular heterogeneity, can be seriously impaired by chromosomal position effects at the site of transgene integration. Many clones may therefore need to be screened before one with optimal induction characteristics is identified. Furthermore, such screens must be repeated for each new transgene investigated, and comparisons between clones with different transgenes is complicated by their different integration sites. Results To circumvent these problems we have developed a "screen and insert" strategy in which clones carrying a transgene for a fluorescent reporter are first screened for those with optimal induction characteristics. Site-specific recombination (SSR) is then be used repeatedly to insert any new transgene at the reporter transgene locus of such clones so that optimal induction characteristics are conferred upon it. Here we have tested in a human fibrosarcoma cell line (HT1080) two of many possible implementations of this approach. Clones (e.g. Rht14-10) in which a GFP reporter gene is very stringently regulated by the tetracycline (tet) transactivator (tTA) protein were first identified flow-cytometrically. Transgenes encoding luciferase, I-SceI endonuclease or Rad52 were then inserted by SSR at a LoxP site adjacent to the GFP gene resulting stringent tet-regulated transgene expression. In clone Rht14-10, increases in expression from essentially background levels (+tet) to more than 104-fold above background (-tet) were reproducibly detected after Cre-mediated insertion of either the luciferase or the I-SceI transgenes. Conclusion Although previous methods have made use of SSR to integrate transgenes at defined sites, none has effectively combined this with a pre-selection step to identify integration sites that support optimal regulatory characteristics. Rht14-10 and similar HT1080-derived clones can now be used in conjunction with a convenient delivery vector (pIN2-neoMCS), in a simple 3-step protocol leading to stringent and reproducible transgene regulation. This approach will be particularly useful for transgenes whose products are very active at low concentrations and/or for comparisons of multiple related transgenes. PMID:17493262

RelA Mutant Enterococcus faecium with Multiantibiotic Tolerance Arising in an Immunocompromised Host.

PubMed

Honsa, Erin S; Cooper, Vaughn S; Mhaissen, Mohammed N; Frank, Matthew; Shaker, Jessica; Iverson, Amy; Rubnitz, Jeffrey; Hayden, Randall T; Lee, Richard E; Rock, Charles O; Tuomanen, Elaine I; Wolf, Joshua; Rosch, Jason W

2017-01-03

Serious bacterial infections in immunocompromised patients require highly effective antibacterial therapy for cure, and thus, this setting may reveal novel mechanisms by which bacteria circumvent antibiotics in the absence of immune pressure. Here, an infant with leukemia developed vancomycin-resistant Enterococcus faecium (VRE) bacteremia that persisted for 26 days despite appropriate antibiotic therapy. Sequencing of 22 consecutive VRE isolates identified the emergence of a single missense mutation (L152F) in relA, which constitutively activated the stringent response, resulting in elevated baseline levels of the alarmone guanosine tetraphosphate (ppGpp). Although the mutant remained susceptible to both linezolid and daptomycin in clinical MIC testing and during planktonic growth, it demonstrated tolerance to high doses of both antibiotics when growing in a biofilm. This biofilm-specific gain in resistance was reflected in the broad shift in transcript levels caused by the mutation. Only an experimental biofilm-targeting ClpP-activating antibiotic was able to kill the mutant strain in an established biofilm. The relA mutation was associated with a fitness trade-off, forming smaller and less-well-populated biofilms on biological surfaces. We conclude that clinically relevant relA mutations can emerge during prolonged VRE infection, causing baseline activation of the stringent response, subsequent antibiotic tolerance, and delayed eradication in an immunocompromised state. The increasing prevalence of antibiotic-resistant bacterial pathogens is a major challenge currently facing the medical community. Such pathogens are of particular importance in immunocompromised patients as these individuals may favor emergence of novel resistance determinants due to lack of innate immune defenses and intensive antibiotic exposure. During the course of chemotherapy, a patient developed prolonged bacteremia with vancomycin-resistant Enterococcus faecium that failed to clear despite multiple front-line antibiotics. The consecutive bloodstream isolates were sequenced, and a single missense mutation identified in the relA gene, the mediator of the stringent response. Strains harboring the mutation had elevated baseline levels of the alarmone and displayed heightened resistance to the bactericidal activity of multiple antibiotics, particularly in a biofilm. Using a new class of compounds that modulate ClpP activity, the biofilms were successfully eradicated. These data represent the first clinical emergence of mutations in the stringent response in vancomycin-resistant entereococci. Copyright © 2017 Honsa et al.

UV disinfection for reuse applications in North America.

PubMed

Sakamoto, G; Schwartzel, D; Tomowich, D

2001-01-01

In an effort to conserve and protect limited water resources, the States of Florida and California have actively promoted wastewater reclamation and have implemented comprehensive regulations covering a range of reuse applications. Florida has a semi-tropical climate with heavy summer rains that are lost due to run off and evaporation. Much of California is arid and suffers periodic droughts, low annual rainfall and depleted ground water supplies. The high population density combined with heavy irrigation demands has depleted ground water supplies resulting in salt-water intrusion. During the past decade, Florida reuse sites have increased dramatically from 118 to 444 plants representing a total flow capacity of 826 MGD. California presently has over 250 plants producing 1 BGD with a projected increase of 160 sites over the next 20 years. To prevent the transmission of waterborne diseases, disinfection of reclaimed water is controlled by stringent regulations. Many states regulate wastewater treatment processes, nutrient removal, final effluent quality and disinfection criteria based upon the specific reuse application. As a rule, the resulting effluents have low turbidity and suspended solids. For such effluents, UV technology can economically achieve the most stringent disinfection targets that are required by the States of California and Florida for restricted and unrestricted reuse. This paper compares UV disinfection for wastewater reuse sites in California and Florida and discusses the effect of effluent quality on UV disinfection.

Planned Environmental Microbiology Aspects of Future Lunar and Mars Missions

NASA Technical Reports Server (NTRS)

Ott, C. Mark; Castro, Victoria A.; Pierson, Duane L.

2006-01-01

With the establishment of the Constellation Program, NASA has initiated efforts designed similar to the Apollo Program to return to the moon and subsequently travel to Mars. Early lunar sorties will take 4 crewmembers to the moon for 4 to 7 days. Later missions will increase in duration up to 6 months as a lunar habitat is constructed. These missions and vehicle designs are the forerunners of further missions destined for human exploration of Mars. Throughout the planning and design process, lessons learned from the International Space Station (ISS) and past programs will be implemented toward future exploration goals. The standards and requirements for these missions will vary depending on life support systems, mission duration, crew activities, and payloads. From a microbiological perspective, preventative measures will remain the primary techniques to mitigate microbial risk. Thus, most of the effort will focus on stringent preflight monitoring requirements and engineering controls designed into the vehicle, such as HEPA air filters. Due to volume constraints in the CEV, in-flight monitoring will be limited for short-duration missions to the measurement of biocide concentration for water potability. Once long-duration habitation begins on the lunar surface, a more extensive environmental monitoring plan will be initiated. However, limited in-flight volume constraints and the inability to return samples to Earth will increase the need for crew capabilities in determining the nature of contamination problems and method of remediation. In addition, limited shelf life of current monitoring hardware consumables and limited capabilities to dispose of biohazardous trash will drive flight hardware toward non-culture based methodologies, such as hardware that rapidly distinguishes biotic versus abiotic surface contamination. As missions progress to Mars, environmental systems will depend heavily on regeneration of air and water and biological waste remediation and regeneration systems, increasing the need for environmental monitoring. Almost complete crew autonomy will be needed for assessment and remediation of contamination problems. Cabin capacity will be limited; thus, current methods of microbial monitoring will be inadequate. Future methodology must limit consumables, and these consumables must have a shelf life of over three years. In summary, missions to the moon and Mars will require a practical design that prudently uses available resources to mitigate microbial risk to the crew.

Energy Market and Economic Impacts of S. 280, the Climate Stewardship and Innovation Act of 2007

EIA Publications

2007-01-01

This report responds to a request from Senators Joseph Lieberman and John McCain for an estimate of the economic impacts of S.280, the Climate Stewardship and Innovation Act of 2007. S. 280 would establish a series of caps on greenhouse gas emissions starting in 2012 followed by increasingly stringent caps beginning in 2020, 2030 and 2050. The report provides estimates of the effects of S. 280 on energy markets and the economy through 2030.

Anogenital warts contain several distinct species of human papillomavirus.

PubMed Central

Krzyzek, R A; Watts, S L; Anderson, D L; Faras, A J; Pass, F

1980-01-01

Anogenital warts from 26 patients were examined for the presence of human papillomavirus (HPV). Although no whole, intact virus could be identified, varying amounts of nonintegrated HPV DNA were detected in 18 tissue specimens (70%) by employing both an agarose gel-ethidium bromide staining method and the Southern blot hybridization procedure. When hybridization analysis was performed under stringent conditions, six anogenital warts were observed to contain HPV genomic sequences related to either of the cutaneous viruses HPV type 1 (HPV-1) or HPV-2. In 12 tissue samples lacking sequence homology to either HPV-1 or HPV-2 under stringent conditions, HPV-related sequences were detected when the hybridization was performed under less stringent conditions, indicating that an HPV distinct from both HPV-1 and HPV-2 is also associated with these lesions. This anogenital HPV also appeared to be distinct from the other characterized types of HPV. These data indicate that at least three HPVs are associated with anogenital wart disease. Images PMID:6255208

Ten Year Study of the Stringently Defined Otitis Prone Child in Rochester, NY

PubMed Central

Pichichero, Michael E.

2016-01-01

This review summarizes a prospective, longitudinal 10-year study in Rochester NY with virtually every clinically diagnosed acute otitis media (AOM) confirmed by bacterial culture of middle ear fluid. Children experiencing 3 episodes within 6 months or 4 episodes in 12 months were considered stringently-defined otitis prone (sOP). We found stringent diagnosis compared with clinical diagnosis reduced the frequency of children meeting the OP definition from 27% to 6% resulting in 14.8% and 2.4% receiving tympanostomy tubes, respectively. Significantly more often RSV infection led to AOM in sOP than non-otitis prone (NOP) children that correlated with diminished total RSV-specific serum IgG. sOP children produced low levels of antibody to Streptococcus pneumoniae and Haemophilus influenzae candidate vaccine protein antigens and to routine pediatric vaccines. sOP children generated significantly fewer memory B cells, functional and memory T cells to otopathogens following NP colonization and AOM than NOP children and they had defects in antigen presenting cells. PMID:27273691

SeaWiFS technical report series. Volume 11: Analysis of selected orbit propagation models for the SeaWiFS mission

NASA Technical Reports Server (NTRS)

Patt, Frederick S.; Hoisington, Charles M.; Gregg, Watson W.; Coronado, Patrick L.; Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Indest, A. W. (Editor)

1993-01-01

An analysis of orbit propagation models was performed by the Mission Operations element of the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) Project, which has overall responsibility for the instrument scheduling. The orbit propagators selected for this analysis are widely available general perturbations models. The analysis includes both absolute accuracy determination and comparisons of different versions of the models. The results show that all of the models tested meet accuracy requirements for scheduling and data acquisition purposes. For internal Project use the SGP4 propagator, developed by the North American Air Defense (NORAD) Command, has been selected. This model includes atmospheric drag effects and, therefore, provides better accuracy. For High Resolution Picture Transmission (HRPT) ground stations, which have less stringent accuracy requirements, the publicly available Brouwer-Lyddane models are recommended. The SeaWiFS Project will make available portable source code for a version of this model developed by the Data Capture Facility (DCF).

The dynamic characteristics of a turbo-rotor simulator supported on gas-lubricated foil bearings. Part 1: Response to rotating imbalance and unidirectional excitation

NASA Technical Reports Server (NTRS)

Licht, L.

1970-01-01

A sixteen-inch rotor, weighing approximately twenty-one pounds, was supported by air-lubricated foil bearings. In physical size and in mass distribution, the rotor closely matched that of an experimental Brayton cycle turboalternator unit. The rotor was stable in both vertical horizontal attitudes at speeds up to 50,000 rpm. A detailed description of the experimental apparatus and of the foil bearing design are given. The paper contains data on response of the rotor to rotating imbalance, symmetric and asymmetric, and to excitation by means of a vibrator (shake table). It is concluded that the gas-lubricated foil bearing suspension is free from fractional frequency whirl and suffers no loss of load capacity when excited at frequency equal to half the rotational speed. In contrast to rigid gas bearings, the foil bearing imposes no stringent requirements with respect to dimensional tolerances, cleanliness, or limitations of journal motion within the narrow confines of bearing clearance.

Preservation of protein expression systems at elevated temperatures for portable therapeutic production

PubMed Central

Bessling, Seneca; Thielen, Peter; Zhang, Sherry; Wolfe, Joshua

2017-01-01

Many biotechnology capabilities are limited by stringent storage needs of reagents, largely prohibiting use outside of specialized laboratories. Focusing on a large class of protein-based biotechnology applications, we address this issue by developing a method for preserving cell-free protein expression systems for months above room temperature. Our approach realizes unprecedented long-term stability at elevated temperatures by leveraging the sugar alcohol trehalose, a simple, low-cost, open-air drying step, and strategic separation of reaction components during drying. The resulting preservation capacity enables efficient production of a wide range of on-demand proteins under adverse conditions, for instance during emergency outbreaks or in remote locations. To demonstrate application potential, we use cell-free reagents subjected to months of exposure at 37°C and atmospheric conditions to produce sufficient concentrations of a pyocin protein to kill Pseudomonas aeruginosa, a troublesome pathogen for traumatic and burn wound injuries. Our work makes possible new biotechnology applications that demand ruggedness and scalability. PMID:28446704

Control of lipopolysaccharide biosynthesis and release by Escherichia coli and Salmonella typhimurium.

PubMed Central

Ishiguro, E E; Vanderwel, D; Kusser, W

1986-01-01

The influence of the relA gene on lipopolysaccharide (LPS) biosynthesis and release by Escherichia coli and Salmonella typhimurium was investigated. Similar results were obtained with both species. The incorporation of [3H]galactose into LPS by galE mutants was inhibited by at least 50% (as compared with normal growing controls) during amino acid deprivation of relA+ strains. This inhibition could be prevented by the treatment of the amino acid-deprived relA+ bacteria with chloramphenicol, a known antagonist of the stringent control mechanism. Furthermore, LPS biosynthesis was not inhibited during amino acid deprivation of isogenic relA mutant strains. These results indicate that LPS synthesis is regulated by the stringent control mechanism. Normal growing cells of both relA+ and relA strains released LPS into the culture fluid at low rates. Amino acid deprivation stimulated the rate of LPS release by relA mutants but not by relA+ bacteria. Chloramphenicol treatment markedly stimulated the release of cell-bound LPS by amino acid-deprived relA+ cells. Thus, a low rate of LPS release was characteristic of normal growth and could be increased in nongrowing cells by relaxing the control of LPS synthesis. Images PMID:3531174

Control of mercury emissions from stationary coal combustion sources in China: Current status and recommendations.

PubMed

Hu, Yuanan; Cheng, Hefa

2016-11-01

Coal burning in power plants and industrial boilers is the largest combustion source of mercury emissions in China. Together, power plants and industrial boilers emit around 250 tonnes of mercury each year, or around half of atmospheric mercury emissions from anthropogenic sources in the country. Power plants in China are generally equipped with multi-pollutant control technologies, which offer the co-benefit of mercury removal, while mercury-specific control technologies have been installed in some facilities. In contrast, most industrial boilers have only basic or no flue gas cleaning. A combination of measures, including energy conservation, coal switching and blending, reducing the mercury contents of coals through washing, combustion controls, and flue gas cleaning, can be used to reduce mercury emissions from these stationary combustion sources. More stringent emission standards for the major air pollutants from coal-fired power plants and industrial boiler, along with standards for the previously unregulated mercury, were implemented recently, which is expected to bring significant reduction in their mercury emissions through the necessary upgrades of multi-pollutant and mercury-specific control technologies. Meanwhile, strong monitoring capacity and strict enforcement are necessary to ensure that the combustion sources operate in compliance with the new emission standards and achieve significant reduction in the emissions of mercury and other air pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-Model Comparison of Lateral Boundary Contributions to ...

EPA Pesticide Factsheets

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. The third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) provides an opportunity to investigate this issue through the combined efforts of multiple research groups in the US and Europe. The model results cover a range of representations of chemical and physical processes, vertical and horizontal resolutions, and meteorological fields to drive the regional chemical transport models (CTMs), all of which are important components of model uncertainty (Solazzo and Galmarini, 2016). In AQMEII3, all groups were asked to track the contribution of ozone from lateral boundary through the use of chemically inert tracers. Though the inert tracer method tends to overestimate the impact of ozone boundary conditions compared with other methods such as chemically reactive tracers and source apportionment (Baker et al., 2015), the method takes the least effort to implement in different models, and is thus useful in highlighting and understanding the process-level differences amongst the models. In this study, results from four models were included (CMAQ driven by WRF, CAMx driven by WRF, CMAQ driven by CCLM, DEHM driven by WRF). At each site, the distribution of daily maximum 8-hour ozone, and the corre

Blue Skies Bluer?

PubMed

Marshall, Julian D; Apte, Joshua S; Coggins, Jay S; Goodkind, Andrew L

2015-12-15

The largest U.S. environmental health risk is cardiopulmonary mortality from ambient PM2.5. The concentration-response (C-R) for ambient PM2.5 in the U.S. is generally assumed to be linear: from any initial baseline, a given concentration reduction would yield the same improvement in health risk. Recent evidence points to the perplexing possibility that the PM2.5 C-R for cardiopulmonary mortality and some other major endpoints might be supralinear: a given concentration reduction would yield greater improvements in health risk as the initial baseline becomes cleaner. We explore the implications of supralinearity for air policy, emphasizing U.S. If C-R is supralinear, an economically efficient PM2.5 target may be substantially more stringent than under current standards. Also, if a goal of air policy is to achieve the greatest health improvement per unit of PM2.5 reduction, the optimal policy might call for greater emission reductions in already-clean locales-making "blue skies bluer"-which may be at odds with environmental equity goals. Regardless of whether the C-R is linear or supralinear, the health benefits of attaining U.S. PM2.5 levels well below the current standard would be large. For the supralinear C-R considered here, attaining the current U.S. EPA standard, 12 μg m(-3), would avert only ~17% (if C-R is linear: ∼ 25%) of the total annual cardiopulmonary mortality attributable to PM2.5.

CoFlame: A refined and validated numerical algorithm for modeling sooting laminar coflow diffusion flames

NASA Astrophysics Data System (ADS)

Eaves, Nick A.; Zhang, Qingan; Liu, Fengshan; Guo, Hongsheng; Dworkin, Seth B.; Thomson, Murray J.

2016-10-01

Mitigation of soot emissions from combustion devices is a global concern. For example, recent EURO 6 regulations for vehicles have placed stringent limits on soot emissions. In order to allow design engineers to achieve the goal of reduced soot emissions, they must have the tools to so. Due to the complex nature of soot formation, which includes growth and oxidation, detailed numerical models are required to gain fundamental insights into the mechanisms of soot formation. A detailed description of the CoFlame FORTRAN code which models sooting laminar coflow diffusion flames is given. The code solves axial and radial velocity, temperature, species conservation, and soot aggregate and primary particle number density equations. The sectional particle dynamics model includes nucleation, PAH condensation and HACA surface growth, surface oxidation, coagulation, fragmentation, particle diffusion, and thermophoresis. The code utilizes a distributed memory parallelization scheme with strip-domain decomposition. The public release of the CoFlame code, which has been refined in terms of coding structure, to the research community accompanies this paper. CoFlame is validated against experimental data for reattachment length in an axi-symmetric pipe with a sudden expansion, and ethylene-air and methane-air diffusion flames for multiple soot morphological parameters and gas-phase species. Finally, the parallel performance and computational costs of the code is investigated.

Continuous reduction of cyclic adsorbed and desorbed NO(x) in diesel emission using nonthermal plasma.

PubMed

Kuwahara, Takuya; Nakaguchi, Harunobu; Kuroki, Tomoyuki; Okubo, Masaaki

2016-05-05

Considering the recent stringent regulations governing diesel NO(x) emission, an aftertreatment system for the reduction of NO(x) in the exhaust gas has been proposed and studied. The proposed system is a hybrid method combining nonthermal plasma and NOx adsorbent. The system does not require precious metal catalysts or harmful chemicals such as urea and ammonia. In the present system, NO(x) in diesel emission is treated by adsorption and desorption by adsorbent as well as nonthermal plasma reduction. In addition, the remaining NO(x) in the adsorbent is desorbed again in the supplied air by residual heat. The desorbed NO(x) in air recirculates into the intake of the engine, and this process, i.e., exhaust gas components' recirculation (EGCR) achieves NO(x) reduction. Alternate utilization of two adsorption chambers in the system can achieve high-efficiency NO(x) removal continuously. An experiment with a stationary diesel engine for electric power generation demonstrates an energy efficiency of 154 g(NO2)/kWh for NO(x) removal and continuous NO(x) reduction of 70.3%. Considering the regulation against diesel emission in Japan, i.e., the new regulation to be imposed on vehicles of 3.5-7.5 ton since 2016, the present aftertreatment system fulfills the requirement with only 1.0% of engine power. Copyright © 2016. Published by Elsevier B.V.

Cyber Safety and Security for Reduced Crew Operations (RCO)

NASA Technical Reports Server (NTRS)

Driscoll, Kevin

2017-01-01

NASA and the Aviation Industry is looking into reduced crew operations (RCO) that would cut today's required two-person flight crews down to a single pilot with support from ground-based crews. Shared responsibility across air and ground personnel will require highly reliable and secure data communication and supporting automation, which will be safety-critical for passenger and cargo aircraft. This paper looks at the different types and degrees of authority delegation given from the air to the ground and the ramifications of each, including the safety and security hazards introduced, the mitigation mechanisms for these hazards, and other demands on an RCO system architecture which would be highly invasive into (almost) all safety-critical avionics. The adjacent fields of unmanned aerial systems and autonomous ground vehicles are viewed to find problems that RCO may face and related aviation accident scenarios are described. The paper explores possible data communication architectures to meet stringent performance and information security (INFOSEC) requirements of RCO. Subsequently, potential challenges for RCO data communication authentication, encryption and non-repudiation are identified. The approach includes a comprehensive safety-hazard analysis of the RCO system to determine top level INFOSEC requirements for RCO and proposes an option for effective RCO implementation. This paper concludes with questioning the economic viability of RCO in light of the expense of overcoming the operational safety and security hazards it would introduce.

Guanosine 3'-diphosphate 5'-diphosphate is not required for growth rate-dependent control of rRNA synthesis in Escherichia coli.

PubMed Central

Gaal, T; Gourse, R L

1990-01-01

rRNA synthesis in Escherichia coli is subject to at least two regulation systems, growth rate-dependent control and stringent control. The inverse correlation between rRNA synthesis rates and guanosine 3'-diphosphate 5'-diphosphate (ppGpp) levels under various physiological conditions has led to the supposition that ppGpp is the mediator of both control mechanisms by inhibiting transcription from rrn P1 promoters. Recently, relA- spoT- strains have been constructed in which both ppGpp synthesis pathways most likely have been removed (M. Cashel, personal communication). We have confirmed that such strains produce no detectable ppGpp and therefore offer a direct means for testing the involvement of ppGpp in the regulation of rRNA synthesis in vivo. Stringent control was determined by measurement of rRNA synthesis after amino acid starvation, while growth rate control was determined by measurement of rRNA synthesis under different nutritional conditions. As expected, the relA- spoT- strain is relaxed for stringent control. However, growth rate-dependent regulation is unimpaired. These results indicate that growth rate regulation can occur in the absence of ppGpp and imply that ppGpp is not the mediator, or at least is not the sole mediator, of growth rate-dependent control. Therefore, growth rate-dependent control and stringent control may utilize different mechanisms for regulating stable RNA synthesis. PMID:2196571

Stringent homology-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions

PubMed Central

2014-01-01

Background H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are essential for understanding the infection mechanism of the formidable pathogen M. tuberculosis H37Rv. Computational prediction is an important strategy to fill the gap in experimental H. sapiens-M. tuberculosis H37Rv PPI data. Homology-based prediction is frequently used in predicting both intra-species and inter-species PPIs. However, some limitations are not properly resolved in several published works that predict eukaryote-prokaryote inter-species PPIs using intra-species template PPIs. Results We develop a stringent homology-based prediction approach by taking into account (i) differences between eukaryotic and prokaryotic proteins and (ii) differences between inter-species and intra-species PPI interfaces. We compare our stringent homology-based approach to a conventional homology-based approach for predicting host-pathogen PPIs, based on cellular compartment distribution analysis, disease gene list enrichment analysis, pathway enrichment analysis and functional category enrichment analysis. These analyses support the validity of our prediction result, and clearly show that our approach has better performance in predicting H. sapiens-M. tuberculosis H37Rv PPIs. Using our stringent homology-based approach, we have predicted a set of highly plausible H. sapiens-M. tuberculosis H37Rv PPIs which might be useful for many of related studies. Based on our analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent homology-based approach, we have discovered several interesting properties which are reported here for the first time. We find that both host proteins and pathogen proteins involved in the host-pathogen PPIs tend to be hubs in their own intra-species PPI network. Also, both host and pathogen proteins involved in host-pathogen PPIs tend to have longer primary sequence, tend to have more domains, tend to be more hydrophilic, etc. And the protein domains from both host and pathogen proteins involved in host-pathogen PPIs tend to have lower charge, and tend to be more hydrophilic. Conclusions Our stringent homology-based prediction approach provides a better strategy in predicting PPIs between eukaryotic hosts and prokaryotic pathogens than a conventional homology-based approach. The properties we have observed from the predicted H. sapiens-M. tuberculosis H37Rv PPI network are useful for understanding inter-species host-pathogen PPI networks and provide novel insights for host-pathogen interaction studies. Reviewers This article was reviewed by Michael Gromiha, Narayanaswamy Srinivasan and Thomas Dandekar. PMID:24708540

Mask etcher data strategy for 45nm and beyond

NASA Astrophysics Data System (ADS)

Lewington, Richard; Ibrahim, Ibrahim M.; Panayil, Sheeba; Kumar, Ajay; Yamartino, John

2006-05-01

Mask Etching for the 45nm technology node and beyond requires a system-level data and diagnostics strategy. This necessity stems from the need to control the performance of the mask etcher to increasingly stringent and diverse requirements of the mask production environment. Increasing mask costs and the capability to acquire and consolidate a wealth of data within the mask etch platform are primary motivators towards harnessing data mines for feedback into the mask etching optimization. There are offline and real-time possibilities and scenarios. Here, we discuss the data architecture, acquisition, and strategies of the Applied Materials Tetra II TM Mask Etch System.

Impact of a nitrogen emission control area (NECA) for ship traffic on the future air quality in the Baltic Sea region

NASA Astrophysics Data System (ADS)

Karl, Matthias; Geyer, Beate; Bieser, Johannes; Matthias, Volker; Quante, Markus; Jalkanen, Jukka-Pekka; Johansson, Lasse; Fridell, Erik

2017-04-01

Deposition of nitrogen compounds originating from shipping activities contribute to eutrophication of the Baltic Sea and coastal areas in the Baltic Sea region. Emissions of nitrogen oxides (NOx) from shipping on the Baltic Sea are comparable to the combined land-based emissions of NOx from Finland and Sweden and have been relatively stable over the last decade. However, expected future growth of maritime transport will result in higher fuel consumption and, if not compensated by increased transport efficiency or other measures, lead to higher total emissions of NOx from shipping. For the Baltic Sea a nitrogen emission control area (NECA) will become effective in 2021 - permitting only new built ships that are compliant with stringent Tier III emission limits - with the target of reducing NOx-emissions. In order to study the effect of implementing a Baltic Sea NECA-2021 on air quality and nitrogen deposition two future scenarios were designed; one with implementation of a NECA for the Baltic Sea starting in 2021 and another with no NECA implemented. The same increase of ship traffic was assumed for both future scenarios. Since complete fleet renewal with low NOx-emitting engines is not expected until 20-30 years after the NECA entry date, year 2040 was chosen as future scenario year. The Community Multiscale Air Quality (CMAQ) model was used to simulate the current and future air quality situation. The nested simulation runs with CMAQ were performed on a horizontal resolution of 4 km × 4 km for the entire Baltic Sea region. The meteorological year 2012 was chosen for the simulation of the current and future air quality situation since the 2m-temperature and precipitation anomalies of 2012 are closely aligned to the 2004-2014 decadal average over Baltic Proper. High-resolution meteorology obtained from COSMO-CLM was used for the regional simulations. Ship emissions were generated with the Ship Traffic Emission Assessment Model (STEAM) by the Finnish Meteorological Institute (FMI) using the Automatic Identification System (AIS) network data to allocate ship positions. Gridded land-based emissions were taken from the SMOKE-EU model which is based on the official EMEP data. Future land-based emissions were reduced in accordance with current legislation. Model simulations for the current situation show that shipping emissions are the main contributor to ambient NO2 concentrations over the Baltic Sea. Shipping emissions are responsible for 40-70 % of the particulate nitrate concentrations during the summer months. Relative contribution of shipping emissions to monthly total nitrogen deposition, as a sum of oxidized and reduced nitrogen compounds, was highest in summer, with up to 60 % in the northern part of the Baltic Proper, while it was on average 10 % for other parts of the Baltic Sea. With the NECA in the Baltic Sea in effect from 2021, the reduction of reactive nitrogen concentrations and deposition in the Baltic Sea region compared to a scenario without Tier III regulations is significant.

The Yttrium Effect on Nanoscale Structure, Mechanical Properties, and High-Temperature Oxidation Resistance of (Ti0.6Al0.4)1- x Y x N Multilayer Coatings

NASA Astrophysics Data System (ADS)

Wang, Jingxian; Yazdi, Mohammad Arab Pour; Lomello, Fernando; Billard, Alain; Kovács, András; Schuster, Frédéric; Guet, Claude; White, Timothy J.; Wouters, Yves; Pascal, Céline; Sanchette, Frédéric; Dong, ZhiLi

2017-09-01

As machine tool coating specifications become increasingly stringent, the fabrication of protective titanium aluminum nitride (Ti-Al-N) films by physical vapor deposition (PVD) is progressively more demanding. Nanostructural modification through the incorporation of metal dopants can enhance coating mechanical properties. However, dopant selection and their near-atomic-scale role in performance optimization is limited. Here, yttrium was alloyed in multilayered Ti-Al-N films to tune microstructures, microchemistries, and properties, including mechanical characteristics, adhesion, wear resistance, and resilience to oxidation. By regulating processing parameters, the multilayer period (Λ) and Y content could be adjusted, which, in turn, permitted tailoring of grain nucleation and secondary phase formation. With the composition fixed at x = 0.024 in (Ti0.6Al0.4)1- x Y x N and Λ increased from 5.5 to 24 nm, the microstructure transformed from acicular grains with 〈111〉 preferred orientation to equiaxed grains with 〈200〉 texture, while the hardness (40.8 ± 2.8 GPa to 29.7 ± 4.9 GPa) and Young's modulus (490 ± 47 GPa to 424 ± 50 GPa) concomitantly deteriorated. Alternately, when Λ = 5.5 nm and x in (Ti0.6Al0.4)1- x Y x N was raised from 0 to 0.024, the hardness was enhanced (28.7 ± 7.3 GPa to 40.8 ± 2.8 GPa) while adhesion and wear resistance were not compromised. The Ti-Al-N adopted a rock-salt type structure with Y displacing either Ti or Al and stabilizing a secondary wurtzite phase. Moreover, Y effectively retarded coating oxidation at 1073 K (800 °C) in air by inhibiting grain boundary oxygen diffusion.

Robotic Observatory System Design-Specification Considerations for Achieving Long-Term Sustainable Precision Performance

NASA Astrophysics Data System (ADS)

Wray, J. D.

2003-05-01

The robotic observatory telescope must point precisely on the target object, and then track autonomously to a fraction of the FWHM of the system PSF for durations of ten to twenty minutes or more. It must retain this precision while continuing to function at rates approaching thousands of observations per night for all its years of useful life. These stringent requirements raise new challenges unique to robotic telescope systems design. Critical design considerations are driven by the applicability of the above requirements to all systems of the robotic observatory, including telescope and instrument systems, telescope-dome enclosure systems, combined electrical and electronics systems, environmental (e.g. seeing) control systems and integrated computer control software systems. Traditional telescope design considerations include the effects of differential thermal strain, elastic flexure, plastic flexure and slack or backlash with respect to focal stability, optical alignment and angular pointing and tracking precision. Robotic observatory design must holistically encapsulate these traditional considerations within the overall objective of maximized long-term sustainable precision performance. This overall objective is accomplished through combining appropriate mechanical and dynamical system characteristics with a full-time real-time telescope mount model feedback computer control system. Important design considerations include: identifying and reducing quasi-zero-backlash; increasing size to increase precision; directly encoding axis shaft rotation; pointing and tracking operation via real-time feedback between precision mount model and axis mounted encoders; use of monolithic construction whenever appropriate for sustainable mechanical integrity; accelerating dome motion to eliminate repetitive shock; ducting internal telescope air to outside dome; and the principal design criteria: maximizing elastic repeatability while minimizing slack, plastic deformation and hysteresis to facilitate long-term repeatably precise pointing and tracking performance.

Development of operationally stable inverted organic light-emitting diode prepared without using alkali metals (Presentation Recording)

NASA Astrophysics Data System (ADS)

Fukagawa, Hirohiko; Morii, Katsuyuki; Hasegawa, Munehiro; Gouda, Shun; Tsuzuki, Toshimitsu; Shimizu, Takahisa; Yamamoto, Toshihiro

2015-10-01

The OLED is one of the key devices for realizing future flexible displays and lightings. One of the biggest challenges left for the OLED fabricated on a flexible substrate is the improvement of its resistance to oxygen and moisture. A high barrier layer [a water vapor transmission rate (WVTR) of about 10-6 g/m2/day] is proposed to be necessary for the encapsulation of conventional OLEDs. Some flexible high barrier layers have recently been demonstrated; however, such high barrier layers require a complex process, which makes flexible OLEDs expensive. If an OLED is prepared without using air-sensitive materials such as alkali metals, no stringent encapsulation is necessary for such an OLED. In this presentation, we will discuss our continuing efforts to develop an inverted OLED (iOLED) prepared without using alkali metals. iOLEDs with a bottom cathode are considered to be effective for realizing air-stable OLEDs since the electron injection layer (EIL) can be prepared by fabrication processes that might damage the organic layers, resulting in the enhanced range of materials suitable for EILs. We have demonstrated that a highly efficient and relatively air-stable iOLED can be realized by employing poly(ethyleneimine) as an EIL. Dark spot formation was not observed after 250 days in the poly(ethyleneimine)-based iOLED encapsulated by a barrier film with a WVTR of 10-4 g/m2/day. In addition, we have demonstrated the fabrication of a highly operational stable iOLED utilizing a newly developed EIL. The iOLED exhibits an expected half-lifetime of over 10,000 h from an initial luminance of 1,000 cd/m2.

The Challenge of Fulfilling a Perplexing Space Weather User Requirement

NASA Astrophysics Data System (ADS)

Kunches, J. M.; Boteler, D.; Wang, H.

2006-12-01

To fly commercial aircraft over the poles, it is necessary to ensure that air-ground and air-air communications be maintained throughout the flight. Some U. S. carriers have requested a seven hour lead-time for predictions of HF outages, the primary communication means for flying over the pole. This very difficult-to-meet specification results from the necessity to make alternative fueling arrangements, schedule additional flight crews, modify the loading of the aircraft, etc., to minimize the costs due to redirecting aircraft away from the optimal polar route. To satisfy this stringent requirement, better predictions of solar energetic particle (SEPs) events are necessary. Even soft SEPs can cause HF outages lasting for hours. This requirement challenges the international science community to significantly improve current predictive methodologies. Presently, a 1-2 hour lead-time may be the longest that can be obtained with a reasonable false alarm rate. Globally, there are a number of new programs, organized under the auspices of the International Space Environment Service (ISES), to facilitate progress in meeting the airlines' requirement. The Regional Warning Center in Canada is implementing a network of riometers at high latitudes, so to detect ionospheric conditions that result in HF outages. This chain is now being deployed. The Regional Warning Centers in Russia, China, the United States and Japan are working with the Canadians, to acquire and make available, other real-time data relevant to the problem. These data include solar, interplanetary, geomagnetic and ionospheric data. Clearly this challenge spans the realm of space science, from the solar and galactic origins of energetic particles, to the D-Region of Earth's ionosphere. The presentation will lay out a roadmap for an iterative solution to the prediction challenge, and identify some of the key areas to be addressed.

Variation of ambient non-methane hydrocarbons in Beijing city in summer 2008

NASA Astrophysics Data System (ADS)

Wang, B.; Shao, M.; Lu, S. H.; Yuan, B.; Zhao, Y.; Wang, M.; Zhang, S. Q.; Wu, D.

2010-02-01

In conjunction with hosting the 2008 Beijing Olympics, the municipal government implemented a series of stringent air quality control measures. To assess the impacts on variation of ambient non-methane hydrocarbons (NMHCs), the whole air was sampled by canisters at one urban site and two suburban sites in Beijing, and 55 NMHC species were quantified by gas chromatography equipped with a quadrupole mass spectrometer and a flame ionization detector (GC/MSD/FID) as parts of the field Campaign for the Beijing Olympic Games Air Quality program (CareBeijing). According to the control measures, the data were presented according to four periods: 18-30 June, 8-19 July, 15-24 August (during the Olympic Games), and 6-15 September (during the Paralympic Games). Compared with the levels in June, the mixing ratios of NMHCs obtained in the Olympic and Paralympic Games periods were reduced by 35% and 25%, respectively. Source contributions were calculated using a chemical mass balance model (CMB 8.2). After implementing the control measures, emissions from target sources were obviously reduced, and reductions in vehicle exhaust could explain 48-82% of the reductions of ambient NMHCs. Reductions in emissions from gasoline evaporation, paint and solvent use, and the chemical industry contributed 9-40%, 3-24%, and 1-5%, respectively, to reductions of ambient NMHCs. Sources of liquefied petroleum gas (LPG) and biogenic emissions were not controlled, and contributions from these sources from July to September were stable or even higher than in June. Ozone formation potentials (OFPs) were calculated for the measured NMHCs. The total OFPs during the Olympic and Paralympic Games were reduced by 48% and 32%, respectively, compared with values in June. Reductions in the OFPs of alkenes and aromatics explained 77-92% of total OFP reductions. The alkenes and aromatics were mainly from vehicle exhausts, and reductions of vehicle exhaust gases explained 67-87% of reductions in alkenes and 38-80% of reductions in aromatics. These findings demonstrate the effectiveness of the air quality control measures enacted for the 2008 Olympics and indicate that controlling vehicular emissions could be the most important measure to improve air quality in Beijing.

Variation of ambient non-methane hydrocarbons in Beijing city in summer 2008

NASA Astrophysics Data System (ADS)

Wang, B.; Shao, M.; Lu, S. H.; Yuan, B.; Zhao, Y.; Wang, M.; Zhang, S. Q.; Wu, D.

2010-07-01

In conjunction with hosting the 2008 Beijing Olympics, the municipal government implemented a series of stringent air quality control measures. To assess the impacts on variation of ambient non-methane hydrocarbons (NMHCs), the whole air was sampled by canisters at one urban site and two suburban sites in Beijing, and 55 NMHC species were quantified by gas chromatography equipped with a quadrupole mass spectrometer and a flame ionization detector (GC/MSD/FID) as parts of the field Campaign for the Beijing Olympic Games Air Quality program (CareBeijing). According to the control measures, the data were presented according to four periods: 18-30 June, 8-19 July, 15-24 August (during the Olympic Games), and 6-15 September (during the Paralympic Games). Compared with the levels in June, the mixing ratios of NMHCs obtained in the Olympic and Paralympic Games periods were reduced by 35% and 25%, respectively. Source contributions were calculated using a chemical mass balance model (CMB 8.2). After implementing the control measures, emissions from target sources were obviously reduced, and reductions in vehicle exhaust could explain 48-82% of the reductions of ambient NMHCs. Reductions in emissions from gasoline evaporation, paint and solvent use, and the chemical industry contributed 9-40%, 3-24%, and 1-5%, respectively, to reductions of ambient NMHCs. Sources of liquefied petroleum gas (LPG) and biogenic emissions were not controlled, and contributions from these sources from July to September were stable or even higher than in June. Ozone formation potentials (OFPs) were calculated for the measured NMHCs. The total OFPs during the Olympic and Paralympic Games were reduced by 48% and 32%, respectively, compared with values in June. Reductions in the OFPs of alkenes and aromatics explained 77-92% of total OFP reductions. The alkenes and aromatics were mainly from vehicle exhausts, and reductions of vehicle exhaust gases explained 67-87% of reductions in alkenes and 38-80% of reductions in aromatics. These findings demonstrate the effectiveness of the air quality control measures enacted for the 2008 Olympics and indicate that controlling vehicular emissions could be the most important measure to improve air quality in Beijing.

Indoor air quality due to secondhand smoke: Signals from selected hospitality locations in rural and urban areas of Bangalore and Dharwad districts in Karnataka, India.

PubMed

Travers, Mark J; Nayak, Nayanatara S; Annigeri, Vinod B; Billava, N Narayan

2015-01-01

Tobacco smoke has compounds that are known as human carcinogens. With every breath of secondhand smoke we inhale thousands of chemicals. The Government of India in the interest of public health has enacted the Cigarette and Other Tobacco Products Act (COTPA), 2003, which bans smoking in all the public places including hotels and restaurants. The purpose of this study was to observe and record air pollution in smoke free and smoke observed locations and thereby find out whether the owners/managers of hotels, restaurants, and bars comply with rules of COTPA. The objectives of the study were to measure and compare the level of particulate air pollution from secondhand smoke (PM2.5) in smoking and nonsmoking venues. The study was conducted from September 2009 to March 2010 in Karnataka, India following a nonrandom sample of 79 locations, which included restaurants, bars, cafes, hotels, and tea stalls in two districts. The concentration of PM2.5 was measured using a TSI SidePak AM510 Personal Aerosol Monitor. In Karnataka out of the 79 hospitality locations, smoking was observed in 58% places and only 28% had displayed the required "No Smoking" signage. Places where indoor smoking was observed had high levels of air pollution with average 135 PM2.5, which were 3.1 times higher than the average 43 PM2.5 in smoke-free locations and 14 times higher than the World Health Organization (WHO) target air quality guideline for PM2.5. The average PM2.5 levels in different locations ranged from 11 to 417 μg/m(3) and was lower in the case of apparently compliant designated smoking area (DSR). The patrons and the workers in the hospitality sector continue to be exposed to secondhand smoke despite the enactment of COTPA, which bans smoking in public places. This situation demands stringent measures for effective implementation of the Smoke Free Act and negative response to smoking among civil society.

A direct sensitivity approach to predict hourly ozone resulting from compliance with the National Ambient Air Quality Standard.

PubMed

Simon, Heather; Baker, Kirk R; Akhtar, Farhan; Napelenok, Sergey L; Possiel, Norm; Wells, Benjamin; Timin, Brian

2013-03-05

In setting primary ambient air quality standards, the EPA's responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and risks associated with ambient ozone pollution using a statistical approach to adjust recent air quality to simulate just meeting the current standard level, without specifying emission control strategies. One drawback of this purely statistical concentration rollback approach is that it does not take into account spatial and temporal heterogeneity of ozone response to emissions changes. The application of the higher-order decoupled direct method (HDDM) in the community multiscale air quality (CMAQ) model is discussed here to provide an example of a methodology that could incorporate this variability into the risk assessment analyses. Because this approach includes a full representation of the chemical production and physical transport of ozone in the atmosphere, it does not require assumed background concentrations, which have been applied to constrain estimates from past statistical techniques. The CMAQ-HDDM adjustment approach is extended to measured ozone concentrations by determining typical sensitivities at each monitor location and hour of the day based on a linear relationship between first-order sensitivities and hourly ozone values. This approach is demonstrated by modeling ozone responses for monitor locations in Detroit and Charlotte to domain-wide reductions in anthropogenic NOx and VOCs emissions. As seen in previous studies, ozone response calculated using HDDM compared well to brute-force emissions changes up to approximately a 50% reduction in emissions. A new stepwise approach is developed here to apply this method to emissions reductions beyond 50% allowing for the simulation of more stringent reductions in ozone concentrations. Compared to previous rollback methods, this application of modeled sensitivities to ambient ozone concentrations provides a more realistic spatial response of ozone concentrations at monitors inside and outside the urban core and at hours of both high and low ozone concentrations.

Periodontal diseases and risk of oral cancer in Southern India: Results from the HeNCe Life study.

PubMed

Laprise, Claudie; Shahul, Hameed Puthiyannal; Madathil, Sreenath Arekunnath; Thekkepurakkal, Akhil Soman; Castonguay, Geneviève; Varghese, Ipe; Shiraz, Shameena; Allison, Paul; Schlecht, Nicolas F; Rousseau, Marie-Claude; Franco, Eduardo L; Nicolau, Belinda

2016-10-01

Some studies suggest that periodontal diseases increase the risk of oral cancer, but contradictory results also exist. Inadequate control of confounders, including life course exposures, may have influenced prior findings. We estimate the extent to which high levels of periodontal diseases, measured by gingival inflammation and recession, are associated with oral cancer risk using a comprehensive subset of potential confounders and applying a stringent adjustment approach. In a hospital-based case-control study, incident oral cancer cases (N = 350) were recruited from two major referral hospitals in Kerala, South India, from 2008 to 2012. Controls (N = 371), frequency-matched by age and sex, were recruited from clinics at the same hospitals. Structured interviews collected information on several domains of exposure via a detailed life course questionnaire. Periodontal diseases, as measured by gingival inflammation and gingival recession, were evaluated visually by qualified dentists following a detailed protocol. The relationship between periodontal diseases and oral cancer risk was assessed by unconditional logistic regression using a stringent empirical selection of potential confounders corresponding to a 1% change-in-estimates. Generalized gingival recession was significantly associated with oral cancer risk (Odds Ratio = 1.83, 95% Confidence Interval: 1.10-3.04). No significant association was observed between gingival inflammation and oral cancer. Our findings support the hypothesis that high levels of periodontal diseases increase the risk of oral cancer. © 2016 UICC.

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

Storey, John Morse; Lewis Sr, Samuel Arthur; Szybist, James P

Gasoline direct injection (GDI) engines can offer improved fuel economy and higher performance over their port fuel-injected (PFI) counterparts, and are now appearing in increasingly more U.S. and European vehicles. Small displacement, turbocharged GDI engines are replacing large displacement engines, particularly in light-duty trucks and sport utility vehicles, in order for manufacturers to meet more stringent fuel economy standards. GDI engines typically emit the most particulate matter (PM) during periods of rich operation such as start-up and acceleration, and emissions of air toxics are also more likely during this condition. A 2.0 L GDI engine was operated at lambda ofmore » 0.91 at typical loads for acceleration (2600 rpm, 8 bar BMEP) on three different fuels; an 87 anti-knock index (AKI) gasoline (E0), 30% ethanol blended with the 87 AKI fuel (E30), and 48% isobutanol blended with the 87 AKI fuel. E30 was chosen to maximize octane enhancement while minimizing ethanol-blend level and iBu48 was chosen to match the same fuel oxygen level as E30. Particle size and number, organic carbon and elemental carbon (OC/EC), soot HC speciation, and aldehydes and ketones were all analyzed during the experiment. A new method for soot HC speciation is introduced using a direct, thermal desorption/pyrolysis inlet for the gas chromatograph (GC). Results showed high levels of aromatic compounds were present in the PM, including downstream of the catalyst, and the aldehydes were dominated by the alcohol blending.« less

Application rate affects the degradation rate and hence emissions of chloropicrin in soil.

PubMed

Ashworth, Daniel J; Yates, Scott R; Stanghellini, Mike; van Wesenbeeck, Ian J

2018-05-01

Increasingly stringent regulations to control soil-air emissions of soil fumigants has led to much research effort aimed at reducing emission potential. Using laboratory soil columns, we aimed to investigate the relationship between chloropicrin (CP) application rate and its emissions from soil across a wide range of CP applications (equivalent to 56-392kgha -1 ). In contrast to the known behavior of other fumigants, total emission percentages were strongly and positively related to application rate (i.e., initial mass), ranging from 4 to 34% across the application rate range. When combined, data from a previous study and the present study showed good overall comparability in terms of CP application rate vs. emission percentage, yielding a second-order polynomial relationship with an R 2 value of 0.93 (n=12). The study revealed that mass losses of CP were strongly disproportional to application rate, also showing a polynomial relationship. Based on degradation studies, we consider that a shorter half-life (faster degradation) at lower application rates limited the amount of CP available for emission. The non-linear relationship between CP application rate and CP emissions (both as % of that applied and as total mass) suggests that low application rates likely lead to disproportionally low emission losses compared with higher application rates; such a relationship could be taken into account when assessing/mitigating risk, e.g., in the setting of buffer zone distances. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulated and unregulated emissions from modern 2010 emissions-compliant heavy-duty on-highway diesel engines.

PubMed

Khalek, Imad A; Blanks, Matthew G; Merritt, Patrick M; Zielinska, Barbara

2015-08-01

The U.S. Environmental Protection Agency (EPA) established strict regulations for highway diesel engine exhaust emissions of particulate matter (PM) and nitrogen oxides (NOx) to aid in meeting the National Ambient Air Quality Standards. The emission standards were phased in with stringent standards for 2007 model year (MY) heavy-duty engines (HDEs), and even more stringent NOX standards for 2010 and later model years. The Health Effects Institute, in cooperation with the Coordinating Research Council, funded by government and the private sector, designed and conducted a research program, the Advanced Collaborative Emission Study (ACES), with multiple objectives, including detailed characterization of the emissions from both 2007- and 2010-compliant engines. The results from emission testing of 2007-compliant engines have already been reported in a previous publication. This paper reports the emissions testing results for three heavy-duty 2010-compliant engines intended for on-highway use. These engines were equipped with an exhaust diesel oxidation catalyst (DOC), high-efficiency catalyzed diesel particle filter (DPF), urea-based selective catalytic reduction catalyst (SCR), and ammonia slip catalyst (AMOX), and were fueled with ultra-low-sulfur diesel fuel (~6.5 ppm sulfur). Average regulated and unregulated emissions of more than 780 chemical species were characterized in engine exhaust under transient engine operation using the Federal Test Procedure cycle and a 16-hr duty cycle representing a wide dynamic range of real-world engine operation. The 2010 engines' regulated emissions of PM, NOX, nonmethane hydrocarbons, and carbon monoxide were all well below the EPA 2010 emission standards. Moreover, the unregulated emissions of polycyclic aromatic hydrocarbons (PAHs), nitroPAHs, hopanes and steranes, alcohols and organic acids, alkanes, carbonyls, dioxins and furans, inorganic ions, metals and elements, elemental carbon, and particle number were substantially (90 to >99%) lower than pre-2007-technology engine emissions, and also substantially (46 to >99%) lower than the 2007-technology engine emissions characterized in the previous study.

Control of rRNA transcription in Escherichia coli.

PubMed Central

Condon, C; Squires, C; Squires, C L

1995-01-01

The control of rRNA synthesis in response to both extra- and intracellular signals has been a subject of interest to microbial physiologists for nearly four decades, beginning with the observations that Salmonella typhimurium cells grown on rich medium are larger and contain more RNA than those grown on poor medium. This was followed shortly by the discovery of the stringent response in Escherichia coli, which has continued to be the organism of choice for the study of rRNA synthesis. In this review, we summarize four general areas of E. coli rRNA transcription control: stringent control, growth rate regulation, upstream activation, and anti-termination. We also cite similar mechanisms in other bacteria and eukaryotes. The separation of growth rate-dependent control of rRNA synthesis from stringent control continues to be a subject of controversy. One model holds that the nucleotide ppGpp is the key effector for both mechanisms, while another school holds that it is unlikely that ppGpp or any other single effector is solely responsible for growth rate-dependent control. Recent studies on activation of rRNA synthesis by cis-acting upstream sequences has led to the discovery of a new class of promoters that make contact with RNA polymerase at a third position, called the UP element, in addition to the well-known -10 and -35 regions. Lastly, clues as to the role of antitermination in rRNA operons have begun to appear. Transcription complexes modified at the antiterminator site appear to elongate faster and are resistant to the inhibitory effects of ppGpp during the stringent response. PMID:8531889

Augmenting the Genetic Toolbox for Sulfolobus islandicus with a Stringent Positive Selectable Marker for Agmatine Prototrophy

PubMed Central

Cooper, Tara E.; Krause, David J.

2013-01-01

Sulfolobus species have become the model organisms for studying the unique biology of the crenarchaeal division of the archaeal domain. In particular, Sulfolobus islandicus provides a powerful opportunity to explore natural variation via experimental functional genomics. To support these efforts, we further expanded genetic tools for S. islandicus by developing a stringent positive selection for agmatine prototrophs in strains in which the argD gene, encoding arginine decarboxylase, has been deleted. Strains with deletions in argD were shown to be auxotrophic for agmatine even in nutrient-rich medium, but growth could be restored by either supplementation of exogenous agmatine or reintroduction of a functional copy of the argD gene from S. solfataricus P2 into the ΔargD host. Using this stringent selection, a robust targeted gene knockout system was established via an improved next generation of the MID (marker insertion and unmarked target gene deletion) method. Application of this novel system was validated by targeted knockout of the upsEF genes involved in UV-inducible cell aggregation formation. PMID:23835176

Detecting Chemical Weapons: Threats, Requirements, Solutions, and Future Challenges

NASA Astrophysics Data System (ADS)

Boso, Brian

2011-03-01

Although chemicals have been reportedly used as weapons for thousands of years, it was not until 1915 at Ypres, France that an industrial chemical, chlorine, was used in World War I as an offensive weapon in significant quantity, causing mass casualties. From that point until today the development, detection, production and protection from chemical weapons has be an organized endeavor of many of the world's armed forces and in more recent times, non-governmental terrorist organizations. The number of Chemical Warfare Agents (CWAs) has steadily increased as research into more toxic substances continued for most of the 20 th century. Today there are over 70 substances including harassing agents like tear gas, incapacitating agents, and lethal agents like blister, blood, chocking, and nerve agents. The requirements for detecting chemical weapons vary depending on the context in which they are encountered and the concept of operation of the organization deploying the detection equipment. The US DoD, for example, has as a requirement, that US forces be able to continue their mission, even in the event of a chemical attack. This places stringent requirements on detection equipment. It must be lightweight (<2 lbs), detect a large array of chemical warfare agents and toxic industrial chemicals, detect and warn at concentration levels and time duration to prevent acute health effects, meet military ruggedness specifications and work over a wide range of temperature and humidity, and have a very high probability of detection with a similarly low probability of false positives. The current technology of choice to meet these stringent requirements is Ion Mobility Spectrometry. Many technologies are capable of detecting chemicals at the trace levels required and have been extensively developed for this application, including, but not limited to: mass spectroscopy, IR spectroscopy, RAMAN spectroscopy, MEMs micro-cantilever sensors, surface acoustic wave sensors, differential mobility spectrometry, and amplifying fluorescence polymers. In the future the requirements for detection equipment will continue to become even more stringent. The continuing increase in the sheer number of threats that will need to be detected, the development of binary agents requiring that even the precursor chemicals be detected, the development of new types of agents unlike any of the current chemistries, and the expansion of the list of toxic industrial chemical will require new techniques with higher specificity and more sensitivity.

Generation and Evaluation of Prophylactic mRNA Vaccines Against Allergy.

PubMed

Weiss, Richard; Scheiblhofer, Sandra; Thalhamer, Josef

2017-01-01

Due to the worldwide increase in allergies and a limited efficacy of therapeutic interventions, the need for prophylactic vaccination against allergies has been recognized. mRNA and DNA vaccines have demonstrated their high potential for preventing allergic sensitization by inducing an immunological bias that prevents TH2 sensitization. However, only mRNA vaccines fulfill the stringent safety requirements for vaccination of healthy children. In this chapter, we describe the generation of conventional as well as self-replicating mRNA vaccines and methods to test their prophylactic efficacy in animal models.

Environmental management problems in India

NASA Astrophysics Data System (ADS)

Bowonder, B.

1986-09-01

Environmental problems are becoming serious in India because of the interacting effects of increasing population density, industrialization and urbanization, and poor environmental management practices. Unless stringent regulatory measures are taken, environmental systems will be irreversibly degraded. Lack of political commitment, lack of a comprehensive environmental policy, poor environmental awareness, functional fragmentation of the public administration system, poor mass media concern, and prevalence of poverty are some of the major factors responsible for increasing the severity of the problems. Environmental problems in India are highly complex, and management procedures have to be developed to achieve coordination between various functional departments, and for this, political leaders have to be convinced of the need to initiate environmental protection measures.

Hologram interferometry in automotive component vibration testing

NASA Astrophysics Data System (ADS)

Brown, Gordon M.; Forbes, Jamie W.; Marchi, Mitchell M.; Wales, Raymond R.

1993-02-01

An ever increasing variety of automotive component vibration testing is being pursued at Ford Motor Company, U.S.A. The driving force for use of hologram interferometry in these tests is the continuing need to design component structures to meet more stringent functional performance criteria. Parameters such as noise and vibration, sound quality, and reliability must be optimized for the lightest weight component possible. Continually increasing customer expectations and regulatory pressures on fuel economy and safety mandate that vehicles be built from highly optimized components. This paper includes applications of holographic interferometry for powertrain support structure tuning, body panel noise reduction, wiper system noise and vibration path analysis, and other vehicle component studies.

Addressing continuous data measured with different instruments for participants excluded from trial analysis: a guide for systematic reviewers.

PubMed

Ebrahim, Shanil; Johnston, Bradley C; Akl, Elie A; Mustafa, Reem A; Sun, Xin; Walter, Stephen D; Heels-Ansdell, Diane; Alonso-Coello, Pablo; Guyatt, Gordon H

2014-05-01

We previously developed an approach to address the impact of missing participant data in meta-analyses of continuous variables in trials that used the same measurement instrument. We extend this approach to meta-analyses including trials that use different instruments to measure the same construct. We reviewed the available literature, conducted an iterative consultative process, and developed an approach involving a complete-case analysis complemented by sensitivity analyses that apply a series of increasingly stringent assumptions about results in patients with missing continuous outcome data. Our approach involves choosing the reference measurement instrument; converting scores from different instruments to the units of the reference instrument; developing four successively more stringent imputation strategies for addressing missing participant data; calculating a pooled mean difference for the complete-case analysis and imputation strategies; calculating the proportion of patients who experienced an important treatment effect; and judging the impact of the imputation strategies on the confidence in the estimate of effect. We applied our approach to an example systematic review of respiratory rehabilitation for chronic obstructive pulmonary disease. Our extended approach provides quantitative guidance for addressing missing participant data in systematic reviews of trials using different instruments to measure the same construct. Copyright © 2014 Elsevier Inc. All rights reserved.

Antibodies Biotinylated Using a Synthetic Z-domain from Protein A Provide Stringent In Situ Protein Detection

PubMed Central

Konrad, Anna; Ashok, Nikhil; Pontén, Fredrik; Hober, Sophia; Asplund, Anna

2013-01-01

Antibody-based protein profiling on a global scale using immunohistochemistry constitutes an emerging strategy for mapping of the human proteome, which is crucial for an increased understanding of biological processes in the cell. Immunohistochemistry is often performed indirectly using secondary antibodies for detection, with the benefit of signal amplification. Direct immunohistochemistry instead brings the advantage of multiplexing; however, it requires labeling of the primary antibody. Many antibody-labeling kits do not specifically target IgG and may therefore cause labeling of stabilizing proteins present in the antibody solution. A new conjugation method has been developed that utilizes a modified Z-domain of protein A (ZBPA) to specifically target the Fc part of antibodies. The aim of the present study was to compare the ZBPA conjugation method and a commercially available labeling kit, Lightning-Link, for in situ protein detection. Fourteen antibodies were biotinylated with each method and stained using immunohistochemistry. For all antibodies tested, ZBPA biotinylation resulted in distinct immunoreactivity without off-target staining, regardless of the presence of stabilizing proteins in the buffer, whereas the majority of the Lightning-Link biotinylated antibodies displayed a characteristic pattern of nonspecific staining. We conclude that biotinylated ZBPA domain provides a stringent method for antibody biotinylation, advantageous for in situ protein detection in tissues. PMID:23920108

Reducing secondary organic aerosol formation from gasoline vehicle exhaust

PubMed Central

Zhao, Yunliang; Saleh, Rawad; Presto, Albert A.; Gordon, Timothy D.; Drozd, Greg T.; Goldstein, Allen H.; Robinson, Allen L.

2017-01-01

On-road gasoline vehicles are a major source of secondary organic aerosol (SOA) in urban areas. We investigated SOA formation by oxidizing dilute, ambient-level exhaust concentrations from a fleet of on-road gasoline vehicles in a smog chamber. We measured less SOA formation from newer vehicles meeting more stringent emissions standards. This suggests that the natural replacement of older vehicles with newer ones that meet more stringent emissions standards should reduce SOA levels in urban environments. However, SOA production depends on both precursor concentrations (emissions) and atmospheric chemistry (SOA yields). We found a strongly nonlinear relationship between SOA formation and the ratio of nonmethane organic gas to oxides of nitrogen (NOx) (NMOG:NOx), which affects the fate of peroxy radicals. For example, changing the NMOG:NOx from 4 to 10 ppbC/ppbNOx increased the SOA yield from dilute gasoline vehicle exhaust by a factor of 8. We investigated the implications of this relationship for the Los Angeles area. Although organic gas emissions from gasoline vehicles in Los Angeles are expected to fall by almost 80% over the next two decades, we predict no reduction in SOA production from these emissions due to the effects of rising NMOG:NOx on SOA yields. This highlights the importance of integrated emission control policies for NOx and organic gases. PMID:28630318

Evaluation of co-benefits from combined climate change and air pollution reduction strategies

NASA Astrophysics Data System (ADS)

Leitao, Joana; Van Dingenen, Rita; Dentener, Frank; Rao, Shilpa

2014-05-01

The connection of climate change and air pollution is becoming more relevant in the process of policy making and implementation of emission control strategies because of resulting co-benefits and trade-offs. Some sectors, such as fossil fuel combustion, are sources of both pollutants (NOx and PM) as well as greenhouse gas (CO2). Additionally, the use of wood burning as biofuel to reduce climate impact may in fact deteriorate air quality. Furthermore, several air pollutants are important radiative forcers and regulating their emissions impacts on climate. It is evident that both problems need to be undertaken with a common strategy and the existence of cross-policy with co-benefits may encourage their implementation. The LIMITS FP7 project (http://www.feem-project.net/limits/index.html) was designed with the main goal of assessing strategies for reduction of GHG emissions so that the 2°C target can be achieved. The work developed focus on the evaluation of the implementation of strategies analysing several aspects of different scenarios, namely: the feasibility of low carbon scenarios in terms of available technologies and infrastructure, the required financial mechanisms, and also the co-benefits regarding energy security, economic development and air pollution. For the latter, five integrated assessment models (IAMs) provided greenhouse gases and pollutant emission values for several scenarios. These were based on air pollution scenarios defined according to stringency and implementation of future global legislation. They which were also combined with 2 climate policy scenarios (no climate policy and 2.8 W/m2 target). The former are mostly focused on non-climate policies and technical control measures for emissions of air pollutants, such as PM2.5, NOx and SO2, with their emission factors harmonized between the IAMs. With the global air quality source-receptor model TM5-FASST the impact of the resulting emissions was analysed and the co-benefits of combined climate and air pollution strategies assessed. The TM5-FASST tool allows for a fast screening of emission scenario variants and the resulting impacts can be investigated by source country, source sector level or by precursor. Developed at JRC, this model is a linearized version derived from the full chemical transport model TM5-CTM, taking as input pollutants emissions from 56 source regions with global coverage. The resulting pollutant concentrations are determined and their associated effect on human health (from PM2.5 and O3), the yield loss of damaged crops (from O3), and CO2eq of short lived climate forcers are quantified. The analysis of the LIMITS scenarios allows for impact assessment of alternate air pollution control assumptions on pollutant emission trajectories out to 2030 and 2050. The results show that stringent climate policies provide a significant air quality benefit compared to current legislation air quality policy. The identified benefits and trade-offs provide a strong incentive for the implementation of combined national policy focusing both on climate change and air pollution.

The Stringent Response Is Essential for Pseudomonas aeruginosa Virulence in the Rat Lung Agar Bead and Drosophila melanogaster Feeding Models of Infection▿†

PubMed Central

Vogt, Stefanie L.; Green, Christopher; Stevens, Katarzyna M.; Day, Brad; Erickson, David L.; Woods, Donald E.; Storey, Douglas G.

2011-01-01

The stringent response is a regulatory system that allows bacteria to sense and adapt to nutrient-poor environments. The central mediator of the stringent response is the molecule guanosine 3′,5′-bispyrophosphate (ppGpp), which is synthesized by the enzymes RelA and SpoT and which is also degraded by SpoT. Our laboratory previously demonstrated that a relA mutant of Pseudomonas aeruginosa, the principal cause of lung infections in cystic fibrosis patients, was attenuated in virulence in a Drosophila melanogaster feeding model of infection. In this study, we examined the role of spoT in P. aeruginosa virulence. We generated an insertion mutation in spoT within the previously constructed relA mutant, thereby producing a ppGpp-devoid strain. The relA spoT double mutant was unable to establish a chronic infection in D. melanogaster and was also avirulent in the rat lung agar bead model of infection, a model in which the relA mutant is fully virulent. Synthesis of the virulence determinants pyocyanin, elastase, protease, and siderophores was impaired in the relA spoT double mutant. This mutant was also defective in swarming and twitching, but not in swimming motility. The relA spoT mutant and, to a lesser extent, the relA mutant were less able to withstand stresses such as heat shock and oxidative stress than the wild-type strain PAO1, which may partially account for the inability of the relA spoT mutant to successfully colonize the rat lung. Our results indicate that the stringent response, and SpoT in particular, is a crucial regulator of virulence processes in P. aeruginosa. PMID:21788391

Secondary lead production in Malaysia

NASA Astrophysics Data System (ADS)

Phillips, M. J.; Lim, S. S.

The increase in the number of vehicles and, subsequently, the volume of batteries made by manufacturers in Malaysia have seen a dramatic rise in lead demand over the last five years. Without any lead mines, the only source of lead in Malaysia has been from the recycling of lead/acid batteries. Metal Reclamation (Industries) has commenced the design of a new and advanced secondary lead plant at West Port, Malaysia to meet the increasing demand for lead and the increasingly stringent environmental regulations. The plant is designed to produce up to 75 000 t of lead and lead alloys per year. The plant will also produce, as by-products: polypropylene chips, wallboard-grade gypsum, non-leachable slag for use in construction. A discussion of the process and the products from the new secondary smelter is outlined.

Comparison of the U.S. lead recycling industry in 1998 and 2011

USGS Publications Warehouse

Wilburn, David R.

2014-01-01

Since 1998, the structure of the lead recycling industry has changed and trade patterns of the domestic lead recycling industry have shifted. Although the domestic demand for lead has remained relatively constant since 1998, production of lead has increasingly shifted to the domestic secondary lead industry. The last primary lead smelter in the United States closed at the end of 2013, at which time the secondary lead industry became the sole source of domestic lead production. The amount of lead recovered annually from scrap batteries generally increased from about 900,000 metric tons in 1995 to more than 1,100,000 metric tons in 2012. The percentage of total U.S. lead production attributed to battery scrap increased from 65 percent in 1995 to 87 percent in 2012. Since the North American Free Trade Agreement took effect in 1994, trade patterns among the United States, Canada, and Mexico have changed for recycled lead products. In the late 1990s, the principal sources of lead waste and scrap not derived from batteries were Canada, Mexico, and South America; by 2011, the principal sources were Central America and Asia, with decreasing amounts from Canada and South America. Since 1998, the amount of lead derived from imported batteries and scrap from Canada has ranged from 50 to 90 percent, and the amount imported from Mexico has ranged from 3 to 20 percent. Canada received about 50 percent of the lead contained in spent lead-acid batteries and scrap exported from the United States in 1998, and Mexico received about 4 percent. By 2012, however, the amount of lead scrap exported to Canada had decreased to about 10 percent, and the amount of lead-based scrap products, primarily batteries, exported to Mexico from the United States had increased to 47 percent. Vertical integration of the domestic secondary lead industry and higher costs required to implement more stringent ambient air standards in the United States have led some companies to shift lead recycling operations to Mexico. U.S. secondary lead producers are increasingly competing with Canadian and Mexican facilities for market share.

Impact of donor age in liver transplantation from donation after circulatory death donors: A decade of experience at Cleveland Clinic.

PubMed

Firl, Daniel J; Hashimoto, Koji; O'Rourke, Colin; Diago-Uso, Teresa; Fujiki, Masato; Aucejo, Federico N; Quintini, Cristiano; Kelly, Dympna M; Miller, Charles M; Fung, John J; Eghtesad, Bijan

2015-12-01

The use of liver grafts from donation after circulatory death (DCD) donors remains controversial, particularly with donors of advanced age. This retrospective study investigated the impact of donor age in DCD liver transplantation. We examined 92 recipients who received DCD grafts and 92 matched recipients who received donation after brain death (DBD) grafts at Cleveland Clinic from January 2005 to June 2014. DCD grafts met stringent criteria to minimize risk factors in both donors and recipients. The 1-, 3-, and 5-year graft survival in DCD recipients was significantly inferior to that in DBD recipients (82%, 71%, 66% versus 92%, 87%, 85%, respectively; P = 0.03). Six DCD recipients (7%), but no DBD recipients, experienced ischemic-type biliary stricture (P = 0.01). However, the incidence of biliary stricture was not associated with donor age (P = 0.57). Interestingly, recipients receiving DCD grafts from donors who were <45 years of age (n = 55) showed similar graft survival rates compared to those receiving DCD grafts from donors who were ≥45 years of age (n = 37; 80%, 69%, 66% versus 83%, 72%, 66%, respectively; P = 0.67). Cox proportional hazards modeling in all study populations (n = 184) revealed advanced donor age (P = 0.05) and the use of a DCD graft (P = 0.03) as unfavorable factors for graft survival. Logistic regression analysis showed that the risk of DBD graft failure increased with increasing age, but the risk of DCD graft failure did not increase with increasing age (P = 0.13). In conclusion, these data suggest that stringent donor and recipient selection may ameliorate the negative impact of donor age in DCD liver transplantation. DCD grafts should not be discarded because of donor age, per se, and could help expand the donor pool for liver transplantation. © 2015 American Association for the Study of Liver Diseases.

The implementation and development of complex alcohol control policies in indigenous communities in Queensland (Australia).

PubMed

Clough, Alan R; Bird, Katrina

2015-04-01

Very high rates of injury and death during the 1990s were linked with increased alcohol availability and misuse in discrete Indigenous communities in rural and remote Queensland (Australia). To address widespread concerns about a public health crisis, from 2002, the Queensland Government implemented alcohol control strategies known as 'Alcohol Management Plans' (AMPs) in 19 of these communities. Although resources for prevention and treatment were promised, AMPs became increasingly focused on local prohibition, restricted access to alcohol and punitive measures for breaching restrictions. An examination of legislation, regulations, explanatory notes, and published documents indicates this focus evolved across four phases since 2002. The first phase, from 2002 to 2004, saw 'restricted areas' with alcohol 'carriage limits' introduced, restricting the amounts and types of liquor permitted within some communities. The second phase (2002-2007) featured evaluations and reviews by the Queensland Government bringing recommendations for more stringent controls. Additionally, beyond the 'restricted areas', licenced premises situated within the 'catchments' of the targeted communities, mainly located in the nearby regional towns, became subject to 'minimising harm' provisions. These more stringent controls were implemented widely in the third phase (2008-2011) when: the operations of seven community-managed liquor outlets were terminated; the trading arrangements of two others were modified; Police powers to search and seize were increased; and 'attempting' to take liquor into a 'restricted area' also became an offence. Some communities have seen a reduction in alcohol-related harms that have been attributed to these alcohol control strategies. This commentary maps the recent regulatory history of Queensland's alcohol controls targeting discrete Indigenous communities highlighting their increasing focus on punitive measures to reduce access to alcohol. With AMPs in Queensland currently under Government review, and with community resolve for change rising, the limits to Government controls and punitive measures may have been reached. Copyright © 2015 Elsevier B.V. All rights reserved.

The Further Development of Heat-Resistant Materials for Aircraft Engines

NASA Technical Reports Server (NTRS)

Bollenrath, Franz

1946-01-01

The present report deals with the problems involved in the greater utilization and development of aircraft engine materials, and specifically; piston materials, cylinder heads, exhaust valves, and exhaust gas turbine blading. The blades of the exhaust gas turbine are likely to be the highest stressed components of modern power plants from a thermal-mechanical and chemical standpoint, even though the requirements on exhaust valves of engines with gasoline injection are in general no less stringent. For the fire plate in Diesel engines the specifications for mechanical strength and design are not so stringent, and the question of heat resistance, which under these circumstances is easier obtainable, predominates.

76 FR 57515 - Energy Conservation Program: Energy Conservation Standards for Residential Refrigerators...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-15

...The Energy Policy and Conservation Act (EPCA) prescribes energy conservation standards for various consumer products and commercial and industrial equipment, including refrigerators, refrigerator-freezers, and freezers. EPCA also requires the U.S. Department of Energy (DOE) to determine if more stringent, amended standards for these products are technologically feasible and economically justified, and would save a significant amount of energy. In this final rule, DOE is adopting more stringent energy conservation standards for refrigerators, refrigerator-freezers, and freezers. It has determined that the amended energy conservation standards for these products would result in the significant conservation of energy and are technologically feasible and economically justified.

An air-stable Na 3SbS 4 superionic conductor prepared by a rapid and economic synthetic procedure

DOE PAGES

Wang, Hui; Chen, Yan; Hood, Zachary D.; ...

2016-01-01

All-solid-state sodium batteries, using abundant sodium resources and solid electrolyte, hold much promise for safe, low cost, large-scale energy storage. To realize the practical applications of all solid Na-ion batteries at ambient temperature, the solid electrolytes are required to have high ionic conductivity, chemical stability, and ideally, easy preparation. Ceramic electrolytes show higher ionic conductivity than polymers, but they often require extremely stringent synthesis conditions, either high sintering temperature above 1000 C or long-time, low-energy ball milling. Herein, we report a new synthesis route for Na 3SbS 4, a novel Na superionic conductor that needs much lower processing temperature belowmore » 200 C and easy operation. This new solid electrolyte exhibits a remarkable ionic conductivity of 1.05 mS cm -1 at 25 °C and is chemically stable under ambient atmosphere. In conclusion, this synthesis process provides unique insight into the current state-of-the-art solid electrolyte preparation and opens new possibilities for the design of similar materials.« less

Effect of calcium formate as an additive on desulfurization in power plants.

PubMed

Li, Zhenhua; Xie, Chunfang; Lv, Jing; Zhai, Ruiguo

2018-05-01

SO 2 in flue gas needs to be eliminated to alleviate air pollution. As the quality of coal decreases and environmental standard requirements become more stringent, the high-efficiency desulfurization of flue gas faces more and more challenges. As an economical and environmentally friendly solution, the effect of calcium formate as an additive on desulfurization efficiency in the wet flue gas desulfurization (WFGD) process was studied for the first time. Improvement of the desulfurization efficiency was achieved with limited change in pH after calcium formate was added into the reactor, and it was found to work better than other additives tested. The positive effects were further verified in a power plant, which showed that adding calcium formate could promote the dissolution of calcium carbonate, accelerate the growth of gypsum crystals and improve the efficiency of desulfurization. Thus, calcium formate was proved to be an effective additive and can potentially be used to reduce the amount of limestone slurry required, as well as the energy consumption and operating costs in industrial desulfurization. Copyright © 2017. Published by Elsevier B.V.

Search for neutrinos from dark matter self-annihilations in the center of the Milky Way with 3 years of IceCube/DeepCore

NASA Astrophysics Data System (ADS)

Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Al Samarai, I.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Argüelles, C.; Auffenberg, J.; Axani, S.; Bagherpour, H.; Bai, X.; Barron, J. P.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Tjus, J. Becker; Becker, K.-H.; BenZvi, S.; Berley, D.; Bernardini, E.; Besson, D. Z.; Binder, G.; Bindig, D.; Blaufuss, E.; Blot, S.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Bourbeau, J.; Bradascio, F.; Braun, J.; Brayeur, L.; Brenzke, M.; Bretz, H.-P.; Bron, S.; Burgman, A.; Carver, T.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cross, R.; Day, M.; de André, J. P. A. M.; De Clercq, C.; DeLaunay, J. J.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Eller, P.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Franckowiak, A.; Friedman, E.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Glauch, T.; Glüsenkamp, T.; Goldschmidt, A.; Gonzalez, J. G.; Grant, D.; Griffith, Z.; Haack, C.; Hallgren, A.; Halzen, F.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Hokanson-Fasig, B.; Hoshina, K.; Huang, F.; Huber, M.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Kalacynski, P.; Kang, W.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kim, J.; Kim, M.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koschinsky, J. P.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krückl, G.; Kunnen, J.; Kunwar, S.; Kurahashi, N.; Kuwabara, T.; Kyriacou, A.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lauber, F.; Lennarz, D.; Lesiak-Bzdak, M.; Leuermann, M.; Liu, Q. R.; Lu, L.; Lünemann, J.; Luszczak, W.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mancina, S.; Maruyama, R.; Mase, K.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Micallef, J.; Momenté, G.; Montaruli, T.; Moore, R. W.; Moulai, M.; Nahnhauer, R.; Nakarmi, P.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Pollmann, A. Obertacke; Olivas, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Peiffer, P.; Pepper, J. A.; de los Heros, C. Pérez; Pieloth, D.; Pinat, E.; Plum, M.; Price, P. B.; Przybylski, G. T.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relethford, B.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Rysewyk, D.; Sälzer, T.; Sanchez Herrera, S. E.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Sarkar, S.; Satalecka, K.; Schlunder, P.; Schmidt, T.; Schneider, A.; Schoenen, S.; Schöneberg, S.; Schumacher, L.; Seckel, D.; Seunarine, S.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stachurska, J.; Stanev, T.; Stasik, A.; Stettner, J.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taboada, I.; Tatar, J.; Tenholt, F.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Tung, C. F.; Turcati, A.; Turley, C. F.; Ty, B.; Unger, E.; Usner, M.; Vandenbroucke, J.; Driessche, W. Van; Eijndhoven, N. van; Vanheule, S.; Santen, J. van; Vehring, M.; Vogel, E.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandler, F. D.; Wandkowsky, N.; Waza, A.; Weaver, C.; Weiss, M. J.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wickmann, S.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wolf, M.; Wood, J.; Wood, T. R.; Woolsey, E.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Yuan, T.; Zoll, M.

2017-09-01

We present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles < σ _{ {A}}v> . Upper limits are set for dark matter particle candidate masses ranging from 10 GeV up to 1 TeV while considering annihilation through multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100 GeV, with a limit of 1.18\\cdot 10^{-23} { cm}^3 {s}^{-1} for 100 GeV dark matter particles self-annihilating via τ ^+τ ^- to neutrinos (assuming the Navarro-Frenk-White dark matter halo profile).

Confined Space Evaluation Student Manual, #19613

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

Chochoms, Michael

Many workplaces contain spaces that are considered to be “confined” because their configuration hinders the activities of employees who must enter into, work in, and exit from them. In general, the permit-required confined spaces (PRCSs) Occupational Safety and Health Administration (OSHA) standard requires that Los Alamos National Laboratory (LANL) evaluate the workplace to determine if any spaces are PRCSs. The standard specifies strict procedures for the evaluation and atmospheric testing of a space before and during an entry by workers. The OSHA PRCS standard provides for alternative (less stringent than full-permit) entry procedures in cases where the only hazard inmore » a space is atmospheric and the hazard can be controlled by forced air. At LANL, all confined spaces or potential confined spaces on LANL-owned or -operated property must be identified and evaluated by a confined space evaluator accompanied by a knowledgeable person. This course provides the information needed by confined space evaluators to make judgements about whether a space is a confined space, and if so, whether the space will require a permit for entry.« less

Alignment telescope for Antares

NASA Astrophysics Data System (ADS)

Appert, Q. D.; Swann, T. A.; Ward, J. H.; Hardesty, C.; Wright, L.

The Antares Automatic Alignment System employs a specially designed telescope for alignment of its laser beamlines. There are two telescopes in the system, and since each telescope is a primary alignment reference, stringent boresight accuracy and stability over the focus range were required. Optical and mechanical designs, which meet this requirements as well as that of image quality over a wide wavelength band, are described. Special test techniques for initial assembly and alignment of the telescope are also presented. The telescope, which has a 180-mm aperture FK51-KZF2 type glass doublet objective, requires a boresight accuracy of 2.8 (SIGMA)rad at two focal lengths, and object distances between 11 meters and infinity. Travel of a smaller secondary doublet provides focus from 11 m to infinity with approximately 7.8 m effective focal length. By flipping in a third doublet, the effective focal length is reduced to 2.5 m. Telescope alignment was accomplished by using a rotary air bearing to establish an axis in front of the system and placing the focus of a Laser Unequal Path Interferometer (LUPI) at the image plane.

Alignment Telescope For Antares

NASA Astrophysics Data System (ADS)

Appert, Q. D.; Swann, T. A.; Ward, J. H.; Hardesty, C.; Wrignt, L.

1983-11-01

The Antares Automatic Alignment System employs a specially designed telescope for alignment of its laser beamlines. There are two telescopes in the system, and since eacn telescope is a primary alignment reference, stringent boresight accuracy and stability over the focus range were required. Optical and mechanical designs, which meet this requirement as well as that of image quality over a wide wavelength band, are described. Special test techniques for initial assembly and alignment of the telescope are also presented. The telescope, which has a 180-mm aperture FK51-KZF2 type glass doublet objective, requires a boresight accuracy of 2.8 prad at two focal lengths, and object distances between 11 meters and infinity. Travel of a smaller secondary doublet provides focus from 11 m to infinity with approximately 7.8 m effective focal length. By flipping in a third doublet, the effective focal length is reduced to 2.5 m. Telescope alignment was accomplished by using a rotary air bearing to establish an axis in front of the system and placing the focus of a Laser Unequal Path Interferometer (LUPI) at the image plane.

Multipactor suppression by micro-structured gold/silver coatings for space applications

NASA Astrophysics Data System (ADS)

Nistor, Valentin; González, Luis A.; Aguilera, Lydya; Montero, Isabel; Galán, Luis; Wochner, Ulrich; Raboso, David

2014-10-01

The secondary electron emission (SEE) from materials used in high power RF devices in space is the main trigger and sustaining mechanism of the resonant avalanche electron discharge known as the multipactor effect. It limits the attainable power of those devices. During recent decades, some scientific research has been focused on material properties for obtaining anti-multipactor coatings of low secondary emission yield (SEY). The European Space Agency (ESA) is leading a technological research on a new approach based on surface roughness that might perform as a kind of blackbody or Faraday cage effect. A multilayer coating structure was adopted for fulfilling the stringent requirements of the space. The surface of a standard silver plating was modified by a two-step treatment. First, a wet chemically etching process created a roughness of high aspect ratio, in the scale of microns. Secondly, the surface was coated with a protective 2 μm overlayer of gold, using magnetron sputtering. This anti-multipactor coating has been tested on several types of Ku-band WR75 waveguide transformers and band-pass filters, with excellent results. The multipactor effect was suppressed for two waveguides, even when applying the maximum available power levels. As for the other final four, the increase of multipactor power level was in the range of 4-6 dB. These results were obtained after more than one year of air exposure. In spite of the strong roughness, the insertion losses were diminished by 25% with respect to the values attained in the tests of the standard anti-multipactor coating, Alodine.

Determination of volatile organic compound emissions and ozone formation from spraying solvent-based pesticides.

PubMed

Kumar, Anuj; Howard, Cody J; Derrick, Doniche; Malkina, Irina L; Mitloehner, Frank M; Kleeman, Michael J; Alaimo, Christopher P; Flocchini, Robert G; Green, Peter G

2011-01-01

Large-scale agricultural activities have come under scrutiny for possible contributions to the emission of ozone precursors. The San Joaquin Valley (SJV) of California is an area with intense agricultural activity that exceeds the federal ozone standards for more than 30 to 40 d yr(-1) and the more stringent state standards for more than 100 d yr(-1). Pesticides are used widely in both agricultural and residential subregions of the SJV, but the largest use, by weight of "active ingredient," is in agriculture. The objective of the study was to determine the role of pesticide application on airborne volatile organic compounds (VOC) concentrations and ozone formation in the SJV. The ozone formation from the pesticide formulation sprayed on commercial orchards was studied using two transportable smog chambers at four application sites during the summers of 2007 and 2008. In addition to the direct measurements of ozone formation, airborne VOC concentrations were measured before and after pesticide spraying using canister and sorbent tube sampling techniques. Soil VOC concentrations were also measured to understand the distribution of VOCs between different environmental compartments. Numerous VOCs were detected in the air and soil samples throughout the experiment but higher molecular weight aromatic hydrocarbons were the primary compounds observed in elevated concentrations immediately after pesticide spraying. Measurements indicate that the ozone concentration formed by VOC downwind of the orchard may increase up to 15 ppb after pesticide application, with a return back to prespray levels after 1 to 2 d. by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The Bendability of Ultra High strength Steels

NASA Astrophysics Data System (ADS)

Hazra, S. K.; Efthymiadis, P.; Alamoudi, A.; Kumar, R. L. V.; Shollock, B.; Dashwood, R.

2016-08-01

Automotive manufacturers have been reducing the weight of their vehicles to meet increasingly stringent environmental legislation that reflects public demand. A strategy is to use higher strength materials for parts with reduced cross-sections. However, such materials are less formable than traditional grades. The frequent result is increased processing and piece costs. 3D roll forming is a novel and flexible process: it is estimated that a quarter of the structure of a vehicle can be made with a single set of tooling. Unlike stamping, this process requires material with low work hardening rates. In this paper, we present results of ultra high strength steels that have low elongation in a tension but display high formability in bending through the suppression of the necking response.

Reducing injury risk from body checking in boys' youth ice hockey.

PubMed

Brooks, Alison; Loud, Keith J; Brenner, Joel S; Demorest, Rebecca A; Halstead, Mark E; Kelly, Amanda K Weiss; Koutures, Chris G; LaBella, Cynthia R; LaBotz, Michele; Martin, Stephanie S; Moffatt, Kody

2014-06-01

Ice hockey is an increasingly popular sport that allows intentional collision in the form of body checking for males but not for females. There is a two- to threefold increased risk of all injury, severe injury, and concussion related to body checking at all levels of boys' youth ice hockey. The American Academy of Pediatrics reinforces the importance of stringent enforcement of rules to protect player safety as well as educational interventions to decrease unsafe tactics. To promote ice hockey as a lifelong recreational pursuit for boys, the American Academy of Pediatrics recommends the expansion of nonchecking programs and the restriction of body checking to elite levels of boys' youth ice hockey, starting no earlier than 15 years of age.

Current Practices and Trends in Mechanical Failure Prevention. Proceedings of the Meeting of the Mechanical Failures Prevention Group (44th) Held in Virginia Beach, Virginia 3-5 April 1990

DTIC Science & Technology

1990-01-01

become a sort of standard for the presence of microplasticity . What we have to realize is that both cleavage and MVC are larger scaled results of finer...34 Paper presented at Naval Sea Systems Command Magnetic Bearing Forum, Washington, D. C., July 1989. 11. Humphris, R. R., R. D. Kelm, D. W. Lewis and P. E...increasingly stringent. Several studies have pointed to the value of this concept. The revolution at sea SOCS study identified the need for and benefits of

New Concept for FES-Induced Movements

NASA Astrophysics Data System (ADS)

Ahmed, Mohammed; Huq, M. S.; Ibrahim, B. S. K. K.; Ahmed, Aisha; Ahmed, Zainab

2016-11-01

Functional Electrical Stimulation (FES) had become a viable option for movement restoration, therapy and rehabilitation in neurologically impaired subjects. Although the number of such subjects increase globally but only few orthosis devices combine with the technique are available and are costly. A factor resulting to this could be stringent requirement for such devices to have passed clinical acceptance. In that regard a new approach which utilize the patient wheelchair as support and also a novel control system to synchronize the stimulation such that the movement is accomplished safely was proposed. It is expected to improve well-being, social integration, independence, cost, and healthcare delivery.

DNA capture elements for rapid detection and identification of biological agents

NASA Astrophysics Data System (ADS)

Kiel, Johnathan L.; Parker, Jill E.; Holwitt, Eric A.; Vivekananda, Jeeva

2004-08-01

DNA capture elements (DCEs; aptamers) are artificial DNA sequences, from a random pool of sequences, selected for their specific binding to potential biological warfare agents. These sequences were selected by an affinity method using filters to which the target agent was attached and the DNA isolated and amplified by polymerase chain reaction (PCR) in an iterative, increasingly stringent, process. Reporter molecules were attached to the finished sequences. To date, we have made DCEs to Bacillus anthracis spores, Shiga toxin, Venezuelan Equine Encephalitis (VEE) virus, and Francisella tularensis. These DCEs have demonstrated specificity and sensitivity equal to or better than antibody.

Holograms for laser diode: Single mode optical fiber coupling

NASA Technical Reports Server (NTRS)

Fuhr, P. L.

1982-01-01

The low coupling efficiency of semiconductor laser emissions into a single mode optical fibers place a severe restriction on their use. Associated with these conventional optical coupling techniques are stringent alignment sensitivities. Using holographic elements, the coupling efficiency may be increased and the alignment sensitivity greatly reduced. Both conventional and computer methods used in the generation of the holographic couplers are described and diagrammed. The reconstruction geometries used are shown to be somewhat restrictive but substantially less rigid than their conventional optical counterparts. Single and double hologram techniques are examined concerning their respective ease of fabrication and relative merits.

Trends and variability of atmospheric PM2.5 and PM10-2.5 concentration in the Po Valley, Italy

NASA Astrophysics Data System (ADS)

Bigi, Alessandro; Ghermandi, Grazia

2016-12-01

The Po Valley is one of the largest European regions with a remarkably high concentration level of atmospheric pollutants, both for particulate and gaseous compounds. In the last decade stringent regulations on air quality standards and on anthropogenic emissions have been set by the European Commission, including also for PM2.5 and its main components since 2008. These regulations have led to an overall improvement in air quality across Europe, including the Po Valley and specifically PM10, as shown in a previous study by Bigi and Ghermandi (2014). In order to assess the trend and variability in PM2.5 in the Po Valley and its role in the decrease in PM10, we analysed daily gravimetric equivalent concentration of PM2.5 and of PM10-2.5 at 44 and 15 sites respectively across the Po Valley. The duration of the times series investigated in this work ranges from 7 to 10 years. For both PM sizes, the trend in deseasonalized monthly means, annual quantiles and in monthly frequency distribution was estimated: this showed a significant decreasing trend at several sites for both size fractions and mostly occurring in winter. All series were tested for a significant weekly periodicity (a proxy to estimate the impact of primary anthropogenic emissions), yielding positive results for summer PM2.5 and for summer and winter PM10-2.5. Hierarchical cluster analysis showed moderate variability in PM2.5 across the valley, with two to three main clusters, dividing the area in western, eastern and southern/Apennines foothill sectors. The trend in atmospheric concentration was compared with the time series of local emissions, vehicular fleet details and fuel sales, suggesting that the decrease in PM2.5 and in PM10 originates from a drop both in primary and in precursors of secondary inorganic aerosol emissions, largely ascribed to vehicular traffic. Potentially, the increase in biomass burning emissions in winter and the modest decrease in NH3 weaken an otherwise even larger drop in atmospheric concentrations.

SU-C-BRC-04: Efficient Dose Calculation Algorithm for FFF IMRT with a Simplified Bivariate Gaussian Source Model

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

Li, F; Park, J; Barraclough, B

2016-06-15

Purpose: To develop an efficient and accurate independent dose calculation algorithm with a simplified analytical source model for the quality assurance and safe delivery of Flattening Filter Free (FFF)-IMRT on an Elekta Versa HD. Methods: The source model consisted of a point source and a 2D bivariate Gaussian source, respectively modeling the primary photons and the combined effect of head scatter, monitor chamber backscatter and collimator exchange effect. The in-air fluence was firstly calculated by back-projecting the edges of beam defining devices onto the source plane and integrating the visible source distribution. The effect of the rounded MLC leaf end,more » tongue-and-groove and interleaf transmission was taken into account in the back-projection. The in-air fluence was then modified with a fourth degree polynomial modeling the cone-shaped dose distribution of FFF beams. Planar dose distribution was obtained by convolving the in-air fluence with a dose deposition kernel (DDK) consisting of the sum of three 2D Gaussian functions. The parameters of the source model and the DDK were commissioned using measured in-air output factors (Sc) and cross beam profiles, respectively. A novel method was used to eliminate the volume averaging effect of ion chambers in determining the DDK. Planar dose distributions of five head-and-neck FFF-IMRT plans were calculated and compared against measurements performed with a 2D diode array (MapCHECK™) to validate the accuracy of the algorithm. Results: The proposed source model predicted Sc for both 6MV and 10MV with an accuracy better than 0.1%. With a stringent gamma criterion (2%/2mm/local difference), the passing rate of the FFF-IMRT dose calculation was 97.2±2.6%. Conclusion: The removal of the flattening filter represents a simplification of the head structure which allows the use of a simpler source model for very accurate dose calculation. The proposed algorithm offers an effective way to ensure the safe delivery of FFF-IMRT.« less

Impact Assessment of Global Temperature Perturbations on Urban and Regional Ozone Levels in South Texas

NASA Astrophysics Data System (ADS)

Biswas, Jhumoor; John, Kuruvilla; Farooqui, Zuber

The recent Intergovernmental Panel on Climate Change report predicts significant temperature increases over the century which constitutes the pulse of climate variability in a region. A modeling study was performed to identify the potential impact of temperature perturbations on tropospheric ozone concentrations in South Texas. A future case modeling scenario which incorporates appropriate emission reduction strategies without accounting for climatic inconsistencies was used in this study. The photochemical modeling was undertaken for a high ozone episode of 13-20 September 1999, and a future modeling scenario was projected for ozone episode days in 2007 utilizing the meteorological conditions prevalent in the base year. The temperatures were increased uniformly throughout the simulation domain and through the vertical layers by 2°C, 3°C, 4°C, 5°C, and 6°C, respectively in the future year modeling case. These temperature perturbations represented the outcome of extreme climate change within the study region. Significantly large changes in peak ozone concentrations were predicted by the photochemical model. For the 6°C temperature perturbation, the greatest amplification in the maximum 8-h ozone concentrations within urban areas of the modeling domain was approximately 12 ppb. In addition, transboundary flux from major industrialized urban areas played a major role in supplementing the high ozone concentrations during the perturbed temperature scenarios. The Unites States Environmental Protection Agency (USEPA) is currently proposing stricter 8-h ozone standards. The effect of temperature perturbations on ozone exceedances based on current and potential stringent future National Ambient Air Quality Standards (NAAQS) was also studied. Temperatures had an appreciable spatial impact on the 8-h ozone exceedances with a considerable increase in spatial area exceeding the NAAQS for the 8-h ozone levels within the study region for each successive augmentation in temperature. The number of exceedances of the 8-h ozone standard increased significantly with each degree rise of temperature with the problem becoming even more acute in light of stricter future proposed standards of ozone.

Characterizing the Effects of Inorganic Acid and Alkaline Shock on the Staphylococcus aureus Transcriptome and Messenger RNA Turnover

PubMed Central

Anderson, Kelsi L.; Roux, Christelle M.; Olson, Matthew W.; Luong, Thanh T.; Lee, Chia Y.; Olson, Robert; Dunman, Paul M.

2010-01-01

Staphylococcus aureus pathogenesis can be partially attributed to its ability to adapt to otherwise deleterious host-associated stresses. Here, Affymetrix GeneChips® were used to examine the S. aureus responses to inorganic acid and alkaline shock and to assess whether stress dependent changes in mRNA turnover are likely to facilitate the organism’s ability to tolerate pH challenge. Results indicate that S. aureus adapts to pH shock by eliciting responses expected of cells coping with pH alteration, including neutralizing cellular pH, DNA repair, amino acid biosynthesis and virulence factor expression. Further, the S. aureus response to alkaline conditions is strikingly similar to that of stringent response induced cells. Indeed, we show that alkaline shock stimulates accumulation of the stringent response activator (p)ppGpp. Results also revealed that pH shock significantly alters the mRNA properties of the cell. A comparison of the mRNA degradation properties of transcripts whose titers either increased or decreased in response to sudden pH change revealed that alterations in mRNA degradation may, in part, account for the changes in the mRNA levels of factors predicted to mediate pH tolerance. A set of small stable RNA molecules were induced in response to acid or alkaline shock conditions and may mediate adaptation to pH stress. PMID:21039920

Ambient noise levels in industrial audiometric test rooms.

PubMed

Frank, T; Williams, D L

1994-05-01

In 1983 the Occupational Safety and Health Administration (OSHA) specified maximum permissible ambient noise levels (MPANLs) that would allow valid hearing threshold measurements in an audiometric test room. However, ambient noise sound pressure levels (SPLs) in rooms used for industrial hearing tests are unknown. The present study reports octave band (125 to 8000 Hz) ambient noise SPLs measured in 490 single-walled prefabricated audiometric test rooms located in industrial settings that were obtained from eight sources. The ambient noise SPLs were highest in the lower frequencies and decreased as frequency increased. All 490 rooms met the OSHA MPANLs. Fortunately, the ambient noise SPLs were considerably lower than the OSHA MPANLs, since previous research has demonstrated that hearing thresholds cannot be obtained down to 0-dB HL in a test room having ambient noise levels equal to the OSHA MPANLs. In fact, 33%, or 162 of the 490 test rooms, met the more stringent MPANLs recently specified by the American National Standards Institute (ANSI) for industrial hearing testing. Given that the OSHA MPANLs are too high and that the test room ambient noise SPLs were considerably less than the OSHA MPANLs, that authors recommend that the OSHA MPANLs be revised to the more stringent ANSI 1991 MPANLs so that hearing thresholds for baseline and annual audiograms can be measured down to 0-dB HL.

Magnetostrictive valve

NASA Technical Reports Server (NTRS)

Casabianca, C. C.

1978-01-01

Device requires no moving parts and has less stringent tolerances. Device uses magnetostrictive powdered metal and electromagnets, rather than solenoid. Device is more reliable than conventional valves.

Atomization and Dispersion of a Liquid Jet Injected Into a Crossflow of Air

NASA Technical Reports Server (NTRS)

Seay, J. E.; Samuelson, G. S.

1996-01-01

In recent years, environmental regulations have become more stringent, requiring lower emissions of mainly nitrogen oxides (NOx), as well as carbon monoxide (CO) and unburned hydrocarbons (UHC). These regulations have forced the gas turbine industry to examine non-conventional combustion strategies, such as the lean burn approach. The reasoning behind operating under lean conditions is to maintain the temperature of combustion near and below temperatures required for the formation of thermal nitric oxide (NO). To be successful, however, the lean processes require careful preparation of the fuel/air mixture to preclude formation of either locally rich reaction zones, which may give rise to NO formation, or locally lean reaction zones, which may give rise to inefficient fuel processing. As a result fuel preparation is crucial to the development and success of new aeroengine combustor technologies. A key element of the fuel preparation process is the fuel nozzle. As nozzle technologies have developed, airblast atomization has been adopted for both industrial and aircraft gas turbine applications. However, the majority of the work to date has focused on prefilming nozzles, which despite their complexity and high cost have become an industry standard for conventional combustion strategies. It is likely that the new strategies required to meet future emissions goals will utilize novel fuel injector approaches, such as radial injection. This thesis proposes and demonstrates an experiment to examine, on a mechanistic level (i.e., the physics of the action), the processes associated with the atomization, evaporation, and dispersion of a liquid jet introduced, from a radial, plain-jet airblast injector, into a crossflow of air. This understanding requires the knowledge not only of what factors influence atomization, but also the underlying mechanism associated with liquid breakup and dispersion. The experimental data acquired identify conditions and geometries for improved performance of radial airblast injectors.

Serum antibody response to Moraxella catarrhalis proteins in stringently defined otitis prone children.

PubMed

Ren, Dabin; Almudevar, Anthony L; Murphy, Timothy F; Lafontaine, Eric R; Campagnari, Anthony A; Luke-Marshall, Nicole; Pichichero, Michael E

2017-07-26

Moraxella catarrhalis (Mcat) is a frequent pathogen of acute otitis media (AOM) in young children. Here we prospectively assessed naturally-induced serum antibodies to four Mcat vaccine candidate proteins in stringently defined otitis prone (sOP) and non-otitis prone (NOP) children age 6-36months old following nasopharyngeal (NP) colonization, at onset of AOM and convalescence from AOM. Serum IgG and IgM antibody against recombinant Mcat proteins, oligopeptide permease A (OppA), outer membrane protein (OMP) CD, hemagglutinin (Hag), and PilA clade 2 (PilA2), were quantitated by ELISA. During NP colonization by Mcat all four antigens were immunogenic in both sOP and NOP children. However, sOP children had lower antibody responses than NOP children across age 6-36months, similar to our findings for protein vaccine candidates of Streptococcus pneumoniae (Spn) and Nontypeable Haemophilus influenzae (NTHi). sOP children displayed a later and lower peak of antibody rise than NOP children for all four antigens during NP colonization of Mcat. The age-dependent increase of antibody ranked as OppA>Hag5-9>OMP CD>PilA2 in both sOP and NOP children. Lower serum antibody levels to the Mcat antigens were measured in sOP compared to NOP children at the onset of AOM. We did not find a consistent significant increase of antibody at the convalescence phase after an AOM event. sOP children is a highly vulnerable population that mount lower serum antibody responses to Mcat candidate vaccine proteins compared to NOP children during asymptomatic NP carriage and at onset of AOM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fit and healthy Paralympians--medical care guidelines for disabled athletes: a study of the injuries and illnesses incurred by the Polish Paralympic team in Beijing 2008 and London 2012.

PubMed

Gawronski, Wojciech; Sobiecka, Joanna; Malesza, Jacek

2013-09-01

Successful performance in Paralympic Games (PGs) requires continuous monitoring of the athletes' health and optimal medical care. To present the health status and disability category of Polish athletes at the Beijing and London PGs, as well as to compare the injuries and illnesses incurred during both PGs in view of the more stringent healthcare guidelines implemented before London. The preparticipation examination (PPE) involved general medical/orthopaedic examination, ECG, blood and urine tests. The mandatory periodic health evaluation (PHE) introduced before London comprised general medical/orthopaedic/dental examination, anthropometric measurement, ECG, stress test, laryngological and ophthalmological consultations, and blood and urine tests. The incidence rate (IR) for all injuries/illnesses with 95% CI, incidence proportion and exposure data (athlete-days) were calculated. There were 91 Polish Paralympians in Beijing and 100 in London. Medical consultations decreased from 151 to 74 (injuries: 57 vs 24 and illnesses: 94 vs 50). In both PGs, respiratory tract infections (RTIs) were the most frequent: IR increased from 15.2 in Beijing to 18.1 in London/1000 athlete-days (95% CI 9.7 to 20.7 vs 11.5 to 24.7). In both PGs, most injuries/illnesses concerned Paralympians with spinal cord injuries. The PPE before both PGs confirmed the disability type according to the general medical classification and revealed no health-related contraindications. Only 6.6% of athletes before Beijing but 100% before London had undergone the multispecialist PHE. In both PGs, illnesses were more frequent than injuries. RTIs presented a serious problem. Some groups of disabled athletes are at an increased risk of injury/illness. The more stringent medical care guidelines before London may have caused staggeringly better results.

Impact of applying the more stringent validation criteria of the revised European Society of Hypertension International Protocol 2010 on earlier validation studies.

PubMed

Stergiou, George S; Karpettas, Nikos; Atkins, Neil; O'Brien, Eoin

2011-04-01

Since 2002 when the European Society of Hypertension International Protocol (ESH-IP) was published it has become the preferred protocol for validating blood pressure monitors worldwide. In 2010, a revised version of the ESH-IP with more stringent criteria was published. This study assesses the impact of applying the revised ESH-IP criteria. A systematic literature review of ESH-IP studies reported between 2002 and 2010 was conducted. The impact of applying the ESH-IP 2010 criteria retrospectively on the data reported in these studies was investigated. The performance of the oscillometric devices in the last decade was also investigated on the basis of the ESH-IP criteria. Among 119 published studies, 112 with sufficient data were analyzed. According to ESH-IP 2002, the test device failed in 19 studies, whereas by applying the ESH-IP 2010 criteria in 28 additional studies increased the failure rate from 17 to 42%. Of these 28 studies, in 20 (71%) the test device failed at part 1 (accuracy per measurement) and in 22 (79%) at part 2 (accuracy per subject). Most of the failures involved the '5 mmHg or less' criterion. In the last decade there has been a consistent trend toward improved performance of oscillometric devices assessed on the basis of the ESH-IP criteria. This retrospective analysis shows that the stricter revised ESH-IP 2010 criteria will noticeably increase the failure rate of devices being validated. Oscillometric devices are becoming more accurate, and the revised ESH-IP by acknowledging this trend will allow more accurate devices to enter the market.

Thermal separation of soil particles from thermal conductivity measurement under various air pressures.

PubMed

Lu, Sen; Ren, Tusheng; Lu, Yili; Meng, Ping; Zhang, Jinsong

2017-01-05

The thermal conductivity of dry soils is related closely to air pressure and the contact areas between solid particles. In this study, the thermal conductivity of two-phase soil systems was determined under reduced and increased air pressures. The thermal separation of soil particles, i.e., the characteristic dimension of the pore space (d), was then estimated based on the relationship between soil thermal conductivity and air pressure. Results showed that under both reduced and increased air pressures, d estimations were significantly larger than the geometrical mean separation of solid particles (D), which suggested that conductive heat transfer through solid particles dominated heat transfer in dry soils. The increased air pressure approach gave d values lower than that of the reduced air pressure method. With increasing air pressure, more collisions between gas molecules and solid surface occurred in micro-pores and intra-aggregate pores due to the reduction of mean free path of air molecules. Compared to the reduced air pressure approach, the increased air pressure approach expressed more micro-pore structure attributes in heat transfer. We concluded that measuring thermal conductivity under increased air pressure procedures gave better-quality d values, and improved soil micro-pore structure estimation.

Conceptual design studies of the 5 m terahertz antenna for Dome A, Antarctica

NASA Astrophysics Data System (ADS)

Yang, Ji; Zuo, Ying-Xi; Lou, Zheng; Cheng, Jing-Quan; Zhang, Qi-Zhou; Shi, Sheng-Cai; Huang, Jia-Sheng; Yao, Qi-Jun; Wang, Zhong

2013-12-01

As the highest, coldest and driest place in Antarctica, Dome A provides exceptionally good observing conditions for ground-based observations over terahertz wavebands. The 5 m Dome A Terahertz Explorer (DATE5) has been proposed to explore new terahertz windows, primarily over wavelengths between 350 and 200 μm. DATE5 will be an open-air, fully-steerable telescope that can function by unmanned operation with remote control. The telescope will be able to endure the harsh polar environment, including high altitude, very low temperature and very low air pressure. The unique specifications, including high accuracies for surface shape and pointing and fully automatic year-around remote operation, along with a stringent limit on the periods of on-site assembly, testing and maintenance, bring a number of challenges to the design, construction, assembly and operation of this telescope. This paper introduces general concepts related to the design of the DATE5 antenna. Beginning from an overview of the environmental and operational limitations, the design specifications and requirements of the DATE5 antenna are listed. From these, major aspects on the conceptual design studies, including the antenna optics, the backup structure, the panels, the subreflector, the mounting and the antenna base structure, are explained. Some critical issues of performance are justified through analyses that use computational fluid dynamics, thermal analysis and de-icing studies, and the proposed approaches for test operation and on-site assembly. Based on these studies, we conclude that the specifications of the DATE5 antenna can generally be met by using enhanced technological approaches.

Neurology cases evaluated by the U.S. Air Force School of Aerospace Medicine 2000-2012.

PubMed

Hesselbrock, Roger; Heaton, John

2014-05-01

Historically, neurologic conditions are a major cause for removing aviators from flying status. Early neuropsychiatry studies included psychiatric conditions along with neurologic disorders. Previously reported data specifically addressing neurologic conditions in aviators are limited. And there is little current neurology-specific data reported. A retrospective review was done on patients with diagnoses evaluated by Neurology at the U.S. Air Force School of Aerospace Medicine Aeromedical Consultation Service (ACS) between 2000 and 2012 using ACS records and databases to identify cases. Patient demographics, major diagnoses with associated International Classification of Diseases (9th rev.) codes, and aeromedical disposition recommendations were abstracted into a separate database for analysis. In total, 871 cases were identified. Patients were predominantly male (91%) with average age 34 and were predominantly pilots (69%). The top neurology-related diagnoses found in our series were headaches, head injuries, and radiculopathies. Of the cases evaluated, 570 aviators (65%) were recommended by ACS to return to flying status. Waiver authorities accepted 88% of ACS recommendations. Current patterns in neurologic conditions in the selected population of cases evaluated by the ACS were presented. Of the neurologic diagnoses seen, a novel finding was the prominence of head injuries in our series not seen in previous studies. This may be due to more stringent aeromedical standards with advances in medical practice and underscores that this issue is not just about disability but affects aircrew operational readiness. Most cases of neurologic disease evaluated by the ACS were recommended for return to flying status.

Metagenomic Analysis of Respiratory Tract DNA Viral Communities in Cystic Fibrosis and Non-Cystic Fibrosis Individuals

PubMed Central

Haynes, Matthew; Schmieder, Robert; Angly, Florent E.; Silva, Joas; Tammadoni, Sassan; Nosrat, Bahador; Conrad, Douglas; Rohwer, Forest

2009-01-01

The human respiratory tract is constantly exposed to a wide variety of viruses, microbes and inorganic particulates from environmental air, water and food. Physical characteristics of inhaled particles and airway mucosal immunity determine which viruses and microbes will persist in the airways. Here we present the first metagenomic study of DNA viral communities in the airways of diseased and non-diseased individuals. We obtained sequences from sputum DNA viral communities in 5 individuals with cystic fibrosis (CF) and 5 individuals without the disease. Overall, diversity of viruses in the airways was low, with an average richness of 175 distinct viral genotypes. The majority of viral diversity was uncharacterized. CF phage communities were highly similar to each other, whereas Non-CF individuals had more distinct phage communities, which may reflect organisms in inhaled air. CF eukaryotic viral communities were dominated by a few viruses, including human herpesviruses and retroviruses. Functional metagenomics showed that all Non-CF viromes were similar, and that CF viromes were enriched in aromatic amino acid metabolism. The CF metagenomes occupied two different metabolic states, probably reflecting different disease states. There was one outlying CF virome which was characterized by an over-representation of Guanosine-5′-triphosphate,3′-diphosphate pyrophosphatase, an enzyme involved in the bacterial stringent response. Unique environments like the CF airway can drive functional adaptations, leading to shifts in metabolic profiles. These results have important clinical implications for CF, indicating that therapeutic measures may be more effective if used to change the respiratory environment, as opposed to shifting the taxonomic composition of resident microbiota. PMID:19816605

Strength of clean indoor air laws and smoking related outcomes in the USA

PubMed Central

McMullen, K; Brownson, R; Luke, D; Chriqui, J

2005-01-01

Objectives: Environmental tobacco smoke (ETS) is often encountered in the workplace. There have been efforts to apply and enforce state laws limiting workplace smoking. There has been little study of the relative effectiveness of state and/or local laws in affecting both rates of workplace ETS exposure and adult smoking rates. This study investigates these hypotheses, as well as the effect of these laws on youth smoking. Design: This is a secondary data analysis using sources including the Current Population Survey (CPS), Behavioral Risk Factor Surveillance System (BRFSS), Youth Risk Behavior Survey (YRBS), and the National Household Survey of Drug Abuse (NHSDA) between the years of 1996 and 1999. Linear regression models were used to investigate the effect of a state's clean indoor air (CIA) law (using a measure of extensiveness) on the overall amount of people who reported working in a smoke-free environment, youth smoking rates and adult smoking rates. Results: The extensiveness of a state's CIA law was found to be a reliable predictor of the percentage of indoor workers who report a smoke-free work environment and the rates of youth smoking. State CIA laws were not conclusively associated with adult smoking rates. Conclusions: The extensiveness of a state's CIA law is strongly associated with a higher percentage of indoor workers reporting a smoke-free work environment. This study did not reveal a similar association between local laws and smoke-free work environments. Youth smoking rates, shown to be related to state CIA laws, may be further affected with more stringent CIA policy. PMID:15735299

Modeling the effects of changes in New Source Review on national SO{sub 2} and NOx emissions from electricity-generating units

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

David A. Evans; Benjamin F. Hobbs; Craig Oren

2007-03-15

The Clean Air Act establishes New Source Review (NSR) programs that apply to the construction or modification of major stationary emissions sources. In 2002 and 2003, the U.S. Environmental Protection Agency revised its rules to narrow the applicability of NSR to facility renovations. Congress then mandated a National Research Council study of the effects of the rules. An electricity-sector model - the Integrated Planning Model (IPM) - was used to explore the possible effects of the equipment replacement provision (ERP), the principal NSR change that was to affect the power-generation industry. The studies focused in particular on coal-fired electricity generatingmore » units, EGUs, for two reasons. First, coal-fired EGUs are important contributors of these pollutants, accounting for approximately 70 and 20% of nations SO{sub 2} and NOx emissions in 2004, respectively. Second, the shares of total capacity of large coal-fired EGUs that lack flue-gas desulfurization to control SO{sub 2} and selective catalytic reduction to reduce NOx emissions are 62 and 63% respectively. Although the analysis cannot predict effects on local emissions, assuming that the Clean Air Interstate Rule (CAIR) is implemented, we find that stringent enforcement of the previous NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. Our results indicate that tighter emissions caps could achieve further decreases in national emissions more cost-effectively than NSR programs. 15 refs., 3 figs., 1 tab.« less

Increased risk of esophageal eosinophilia and eosinophilic esophagitis in patients with active celiac disease on biopsy

PubMed Central

Jensen, Elizabeth T.; Eluri, Swathi; Lebwohl, Benjamin; Genta, Robert M.; Dellon, Evan S.

2015-01-01

Background and Aims The possible association between eosinophilic esophagitis (EoE) and celiac disease (CD) is controversial as prior results have been contradictory. We aimed to determine the relationship between EoE and CD among patients with concomitant esophageal and duodenal biopsies. Methods We conducted a cross-sectional study in a U.S. national pathology database, using data from January 2009 and June 2012. Our primary case definition was defined by the presence of esophageal eosinophilia with ≥ 15 eosinophils per high-power field. The crude and adjusted (for age and sex) odds of esophageal eosinophilia for patients with active CD were compared to those without CD. Sensitivity analyses were performed using more stringent case definitions and by estimating the associations between CD and reflux esophagitis, and CD and Barrett's esophagus (BE). Results Of 292,621 patients in the source population, 88,517 with both esophageal and duodenal biopsies were studied. 4,101 (4.6%) met criteria for EoE and 1,203 (1.4%) met criteria for CD. Odds of EoE were 26% higher in patients with CD than patients without CD (aOR: 1.26, 95% confidence interval [CI]: 0.98 – 1.60). The magnitude of association varied according to EoE case definition (Table 3), but all definitions showed a weak, positive association between the two conditions. There was no association between CD and reflux esophagitis (aOR 0.95, 95% CI: 0.85 – 1.07) or BE (aOR 0.89, 95% CI: 0.69 – 1.14) and CD. Conclusions There is a weak increase in EoE in patients with CD. This association strengthened with increasingly stringent definitions of EoE, and was not observed for other esophageal conditions. In patients with CD, concomitant EoE should be considered in the correct clinical setting. PMID:25724709

Efficacy and safety of an insulin infusion protocol in a surgical ICU.

PubMed

Taylor, Beth E; Schallom, Marilyn E; Sona, Carrie S; Buchman, Timothy G; Boyle, Walter A; Mazuski, John E; Schuerer, Douglas E; Thomas, James M; Kaiser, Christy; Huey, Way Y; Ward, Myrna R; Zack, Jeanne E; Coopersmith, Craig M

2006-01-01

Hyperglycemia is associated with complications in the surgical intensive care unit. The purpose of this study was to determine the efficacy and safety of nurse-driven insulin infusion protocols in lowering blood glucose (BG) in critical illness. All patients in a 24-bed surgical intensive care unit who required i.v. insulin infusions during 3 noncontiguous 6-month periods from 2002 to 2004 were evaluated. In the preintervention phase, 71 patients received a physician-initiated insulin infusion without a developed protocol. They were compared with 95 patients who received a nurse-driven insulin infusion protocol with a target BG of 120 to 150 mg/dL and to 119 patients who received a more stringent protocol with a target BG of 80 to 110 mg/dL. There was a stepwise decrease in average daily BG levels, from 190 to 163 to 132 mg/dL (p < 0.001). The less stringent protocol decreased the time to achieve a BG level < 150 mg/dL from 14.1 to 7.4 hours compared with physician-driven management (p < 0.05) resulting in similar time on an insulin infusion (53 versus 48 hours). The more intensive protocol brought BG levels < 150 mg/dL in 7.2 hours and < 111 mg/dL in 13.6 hours, but increased the length of time a patient was on an insulin infusion to 77 hours. The incidence of severe hypoglycemia (BG < 40 mg/dL) was statistically similar between the groups, ranging between 1.1% and 3.4%. Implementation of a nurse-driven protocol led to more rapid and more effective BG control in critically ill surgical patients compared with physician management. Tighter BG control can be obtained without a significant increase in hypoglycemia, although this is associated with increased time on an insulin infusion.

Increased Risk of Esophageal Eosinophilia and Eosinophilic Esophagitis in Patients With Active Celiac Disease on Biopsy.

PubMed

Jensen, Elizabeth T; Eluri, Swathi; Lebwohl, Benjamin; Genta, Robert M; Dellon, Evan S

2015-08-01

The possible association between eosinophilic esophagitis (EoE) and celiac disease is controversial because prior results have been contradictory. We aimed to determine the relationship between EoE and celiac disease among patients with concomitant esophageal and duodenal biopsies. We conducted a cross-sectional study in a U.S. national pathology database by using data from January 2009 through June 2012. Our primary case definition was defined by the presence of esophageal eosinophilia with ≥15 eosinophils per high-power field. The crude and adjusted (for age and sex) odds of esophageal eosinophilia for patients with active celiac disease were compared with those without celiac disease. Sensitivity analyses were performed by using more stringent case definitions and by estimating the associations between celiac disease and reflux esophagitis and celiac disease and Barrett's esophagus. Of 292,621 patients in the source population, 88,517 with both esophageal and duodenal biopsies were studied. Four thousand one hundred one (4.6%) met criteria for EoE, and 1203 (1.4%) met criteria for celiac disease. Odds of EoE were 26% higher in patients with celiac disease than in patients without celiac disease (adjusted odds ratio [aOR], 1.26; 95% confidence interval [CI], 0.98-1.60). The magnitude of association varied according to EoE case definition, but all definitions showed a weak positive association between the 2 conditions. There was no association between celiac disease and reflux esophagitis (aOR, 0.95; 95% CI, 0.85-1.07) or Barrett's esophagus (aOR, 0.89; 95% CI, 0.69-1.14) and celiac disease. There is a weak increase in EoE in patients with celiac disease. This association strengthened with increasingly stringent definitions of EoE and was not observed for other esophageal conditions. In patients with celiac disease, concomitant EoE should be considered in the correct clinical setting. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

Evolution of the Lunar Receiving Laboratory to the Astromaterial Sample Curation Facility: Technical Tensions Between Containment and Cleanliness, Between Particulate and Organic Cleanliness

NASA Technical Reports Server (NTRS)

Allton, J. H.; Zeigler, R. A.; Calaway, M. J.

2016-01-01

The Lunar Receiving Laboratory (LRL) was planned and constructed in the 1960s to support the Apollo program in the context of landing on the Moon and safely returning humans. The enduring science return from that effort is a result of careful curation of planetary materials. Technical decisions for the first facility included sample handling environment (vacuum vs inert gas), and instruments for making basic sample assessment, but the most difficult decision, and most visible, was stringent biosafety vs ultra-clean sample handling. Biosafety required handling of samples in negative pressure gloveboxes and rooms for containment and use of sterilizing protocols and animal/plant models for hazard assessment. Ultra-clean sample handling worked best in positive pressure nitrogen environment gloveboxes in positive pressure rooms, using cleanable tools of tightly controlled composition. The requirements for these two objectives were so different, that the solution was to design and build a new facility for specific purpose of preserving the scientific integrity of the samples. The resulting Lunar Curatorial Facility was designed and constructed, from 1972-1979, with advice and oversight by a very active committee comprised of lunar sample scientists. The high precision analyses required for planetary science are enabled by stringent contamination control of trace elements in the materials and protocols of construction (e.g., trace element screening for paint and flooring materials) and the equipment used in sample handling and storage. As other astromaterials, especially small particles and atoms, were added to the collections curated, the technical tension between particulate cleanliness and organic cleanliness was addressed in more detail. Techniques for minimizing particulate contamination in sample handling environments use high efficiency air filtering techniques typically requiring organic sealants which offgas. Protocols for reducing adventitious carbon on sample handling surfaces often generate particles. Further work is needed to achieve both minimal particulate and adventitious carbon contamination. This paper will discuss these facility topics and others in the historical context of nearly 50 years' curation experience for lunar rocks and regolith, meteorites, cosmic dust, comet particles, solar wind atoms, and asteroid particles at Johnson Space Center.

Medication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.

PubMed

Warren, Stuart R; Raisch, Dennis W; Campbell, Heather M; Guarino, Peter D; Kaufman, James S; Petrokaitis, Elizabeth; Goldfarb, David S; Gaziano, J Michael; Jamison, Rex L

2013-01-01

Assessment of adherence to study medications is a common challenge in clinical research. Counting unused study medication is the predominant method by which adherence is assessed in outpatient clinical trials but it has limitations that include questionable validity and burdens on research personnel. To compare capsule counts, patient questionnaire responses, and plasma drug levels as methods of determining adherence in a clinical trial that had 2056 participants and used centralized drug distribution and patient follow-up. Capsule counts from study medication bottles returned by participants and responses to questions regarding adherence during quarterly telephone interviews were averaged and compared. Both measures were compared to plasma drug levels obtained at the 3-month study visit of patients in the treatment group. Counts and questionnaire responses were converted to adherence rates (doses taken divided by days elapsed) and were categorized by stringent (≥85.7%) and liberal (≥71.4%) definitions. We calculated the prevalence-adjusted bias-adjusted kappa to assess agreement between the two measures. Using a pre-paid mailer, participants returned 76.0% of study medication bottles to the central pharmacy. Both capsule counts and questionnaire responses were available for 65.8% of participants and were used to assess adherence. Capsule counts identified more patients who were under-adherent (18.8% by the stringent definition and 7.5% by the liberal definition) than self-reports did (10.4% by the stringent definition and 2.1% by the liberal definition). The prevalence-adjusted bias-adjusted kappa was 0.58 (stringent) and 0.83 (liberal), indicating fair and very good agreement, respectively. Both measures were also in agreement with plasma drug levels determined at the 3-month visit (capsule counts: p = 0.005 for the stringent and p = 0.003 for the liberal definition; questionnaire: p = 0.002 for both adherence definitions). Inconsistent bottle returns and incomplete notations of medication start and stop dates resulted in missing data but exploratory missing data analyses showed no reason to believe that the missing data resulted in systematic bias. Depending upon the definition of adherence, there was fair to very good agreement between questionnaire results and capsule counts among returned study bottles, confirmed by plasma drug levels. We conclude that a self-report of medication adherence is potentially comparable to capsule counts as a method of assessing adherence in a clinical trial, if a relatively low adherence threshold is acceptable, but adherence should be confirmed by other measures if a high adherence threshold is required.

NOx adsorber and method of regenerating same

DOEpatents

Endicott, Dennis L [Peoria, IL; Verkiel, Maarten [Metamora, IL; Driscoll, James J [Dunlap, IL

2007-01-30

New technologies, such as NOx adsorber catalytic converters, are being used to meet increasingly stringent regulations on undesirable emissions, including NOx emissions. NOx adsorbers must be periodically regenerated, which requires an increased fuel consumption. The present disclosure includes a method of regenerating a NOx adsorber within a NOx adsorber catalytic converter. At least one sensor positioned downstream from the NOx adsorber senses, in the downstream exhaust, at least one of NOx, nitrous oxide and ammonia concentrations a plurality of times during a regeneration phase. The sensor is in communication with an electronic control module that includes a regeneration monitoring algorithm operable to end the regeneration phase when a time rate of change of the at least one of NOx, nitrous oxide and ammonia concentrations is after an expected plateau region begins.

Noise pollution is pervasive in U.S. protected areas.

PubMed

Buxton, Rachel T; McKenna, Megan F; Mennitt, Daniel; Fristrup, Kurt; Crooks, Kevin; Angeloni, Lisa; Wittemyer, George

2017-05-05

Anthropogenic noise threatens ecological systems, including the cultural and biodiversity resources in protected areas. Using continental-scale sound models, we found that anthropogenic noise doubled background sound levels in 63% of U.S. protected area units and caused a 10-fold or greater increase in 21%, surpassing levels known to interfere with human visitor experience and disrupt wildlife behavior, fitness, and community composition. Elevated noise was also found in critical habitats of endangered species, with 14% experiencing a 10-fold increase in sound levels. However, protected areas with more stringent regulations had less anthropogenic noise. Our analysis indicates that noise pollution in protected areas is closely linked with transportation, development, and extractive land use, providing insight into where mitigation efforts can be most effective. Copyright © 2017, American Association for the Advancement of Science.

Public Policy and Pharmaceutical Innovation

PubMed Central

Grabowski, Henry G.

1982-01-01

Historically, new drug introductions have played a central role in medical progress and the availability of cost-effective therapies. Nevertheless, public policy toward pharmaceuticals has been characterized in recent times by increasingly stringent regulatory controls, shorter effective patent terms, and increased encouragement of generic product usage. This has had an adverse effect on the incentives and capabilities of firms to undertake new drug research and development activity. The industry has experienced sharply rising research and development costs, declining annual new drug introductions, and fewer independent sources of drug development. This paper considers the effects of government regulatory policies on the pharmaceutical innovation process from several related perspectives. It also examines the merits of current public policy proposals designed to stimulate drug innovation including patent restoration and various regulatory reform measures. PMID:10309721

Recurrent Aspiration in a Patient With Gastric Band Undergoing Electroconvulsive Therapy.

PubMed

Lubit, Elana B; Fetterman, Tammy Cohen; Ying, Patrick

2016-06-01

We report a case of a 33-year-old woman with depression and suicidal ideation, treated successfully with electroconvulsive therapy (ECT) in the past. Since her previous course of ECT, she underwent gastric banding, a bariatric surgical procedure associated with increased risk of gastric regurgitation. Despite increasingly stringent measures to minimize the risk of regurgitation and aspiration during ECT, she had several episodes of regurgitation, the last of which precipitated an acute illness consistent with aspiration pneumonitis. We took additional precautions after each event, until she had no further episodes of regurgitation. We discuss the risk posed by the gastric band, the measures we implemented to minimize that risk, and our recommendations for assessment and management of post-gastric banding patients who present for ECT.

Long term operation of high concentration powdered activated carbon membrane bio-reactor for advanced water treatment.

PubMed

Seo, G T; Moon, C D; Chang, S W; Lee, S H

2004-01-01

A pilot scale experiment was conducted to evaluate the performance of a membrane bioreactor filled with high concentration powdered activated carbon. This hybrid system has great potential to substitute for existing GAC or O3/BAC processes in the drinking water treatment train. The system was installed at a water treatment plant located downstream of the Nakdong river basin, Korea. Effluent of rapid sand filter was used as influent of the system which consists of PAC bio-reactor, submerged MF membrane module and air supply facility. PAC concentration of 20 g/L was maintained at the beginning of the experiment and it was increased to 40 g/L. The PAC has not been changed during the operational periods. The membrane was a hollow fiber type with pore sizes of 0.1 and 0.4 microm. It was apparent that the high PAC concentration could prevent membrane fouling. 40 g/L PAC was more effective to reduce the filtration resistance than 20 g/L. At the flux of 0.36 m/d, TMP was maintained less than 40 kPa for about 3 months by intermittent suction type operation (12 min suction/3 min idling). Adsorption was the dominant role to remove DOC at the initial operational period. However the biological effect was gradually increased after around 3 months operation. Constant DOC removal could be maintained at about 40% without any trouble and then a tremendous reduction of DBPs (HAA5 and THM) higher than 85% was achieved. Full nitrification was observed at the controlled influent ammonia nitrogen concentration of 3 and 7 mg/L. pH was an important parameter to keep stable ammonia oxidation. From almost two years of operation, it is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment under the recent situation of more stringent DBPs regulation in Korea.

U.S. Tuna Fisheries: a trifecta of sustainable practices at odds with climate change mitigation

NASA Astrophysics Data System (ADS)

McKuin, B.; Campbell, J. E.

2016-12-01

Environmental concerns have given rise to eco-label initiatives in the seafood industry and a shift to more sustainable fishing practices in the U.S. Currently, the greenhouse gas emissions of fisheries are being considered in the sustainability criteria of the consumer advocacy group Seafood Watch. We looked at sustainable practices employed by U.S. tuna fisheries and find the term "sustainably sourced" changes when climate forcing is added to the criteria. Specifically, there are three sustainable practices at odds with climate change mitigation: 1) the use of selective fishing gear reduces bycatch but increases fuel use; 2) fishing within exclusive economic zones is more equitable to coastal fishermen, and allows the high seas to serve as an ecological bank, but fishing within these regions means fisheries are subject to more stringent fuel sulfur laws thereby diminishing the cooling effects of sulfate aerosols and increasing climate forcing; and 3) removing sulfur from fuels improves air quality but there are added emissions from the refinery process. We used ship registry data, historical sulfur levels in fuels, gear-specific fishery fuel use data collected from the literature, historical gear-specific tuna landings data, and a range of global warming potentials to estimate the climate forcing of U.S. tuna fisheries over the last fifteen years. We found that for tuna caught within exclusive economic zones, the net fuel-related climate forcing has more than doubled over the last fifteen years. We also normalized the fuel-related climate forcing results to a unit of tuna protein and compared these results to other farmed sources of protein. We found that tuna caught within exclusive economic zones has the highest climate impact of all land-based protein sources considered, with the exception of beef. Our results can inform policy makers and consumer advocacy groups which is an important step in communicating the climate impact of dietary choices to consumers.

Criteria Development for Gas Turbine Premixer Flameholding Tendencies of Natural Gas and High Hydrogen Content Fuels

NASA Astrophysics Data System (ADS)

Sullivan-Lewis, Elliot Gregory

Due to increasingly stringent air quality requirements, stationary power gas turbines have moved to lean-premixed operation, which reduces pollutant emissions but can result in flashback. Flashback can cause serious damage to the premixer hardware. Curtailing flashback can be difficult with hydrocarbon fuels and becomes even more challenging when the fuel contains hydrogen. The two main approaches for coping with flashback are either to design a combustor that is resistant to flashback, or to design a premixer that will not anchor a flame if flashback occurs. Even with a well-designed combustor, flashback can occur under certain circumstances. Thus it is necessary to determine how to avoid flameholding within the premixer passageways of a gas turbine. To this end, an experiment was designed that would determine the flameholding propensities at elevated pressures and temperatures of three different classes of geometric features commonly found in gas turbine premixers, with both natural gas and hydrogen containing fuel. Experiments to find the equivalence ratio at blow off were conducted within an optically accessible test apparatus with four flameholders: 0.25 and 0.50 inch diameter cylinders, a reverse facing step with a height of 0.25 inches, and a symmetric airfoil with a thickness of 0.25 inches and a chord length of one inch. Tests were carried out at temperatures between 300 K and 750 K, at pressures up to 9 atmospheres. Typical bulk velocities were between 40 and 100 m/s. The effect of the airfoil's angle of rotation was also investigated. Blow off for hydrogen reactions was found to occur at much lower adiabatic flame temperatures than natural gas reactions. Additionally it was observed that at high pressures and high turbulence intensities, reactant velocity does not have a noticeable effect on the point of blow off due in large part to corresponding increases in turbulent flame speed. Finally a semi empirical correlation was developed that predicts flame extinction for both natural gas and hydrogen containing reactions.

Hypermutation in derepressed operons of Escherichia coli K12

PubMed Central

Wright, Barbara E.; Longacre, Angelika; Reimers, Jacqueline M.

1999-01-01

This article presents evidence that starvation for leucine in an Escherichia coli auxotroph triggers metabolic activities that specifically target the leu operon for derepression, increased rates of transcription, and mutation. Derepression of the leu operon was a prerequisite for its activation by the signal nucleotide, guanosine tetraphosphate, which accumulates in response to nutritional stress (the stringent response). A quantitative correlation was established between leuB mRNA abundance and leuB− reversion rates. To further demonstrate that derepression increased mutation rates, the chromosomal leu operon was placed under the control of the inducible tac promoter. When the leu operon was induced by isopropyl-d-thiogalactoside, both leuB mRNA abundance and leuB− reversion rates increased. These investigations suggest that guanosine tetraphosphate may contribute as much as attenuation in regulating leu operon expression and that higher rates of mutation are specifically associated with the derepressed leu operon. PMID:10220423

Movement amplitude and tempo change in piano performance

NASA Astrophysics Data System (ADS)

Palmer, Caroline

2004-05-01

Music performance places stringent temporal and cognitive demands on individuals that should yield large speed/accuracy tradeoffs. Skilled piano performance, however, shows consistently high accuracy across a wide variety of rates. Movement amplitude may affect the speed/accuracy tradeoff, so that high accuracy can be obtained even at very fast tempi. The contribution of movement amplitude changes in rate (tempo) is investigated with motion capture. Cameras recorded pianists with passive markers on hands and fingers, who performed on an electronic (MIDI) keyboard. Pianists performed short melodies at faster and faster tempi until they made errors (altering the speed/accuracy function). Variability of finger movements in the three motion planes indicated most change in the plane perpendicular to the keyboard across tempi. Surprisingly, peak amplitudes of motion before striking the keys increased as tempo increased. Increased movement amplitudes at faster rates may reduce or compensate for speed/accuracy tradeoffs. [Work supported by Canada Research Chairs program, HIMH R01 45764.

Photon Doppler Velocimeter to Measure Entrained Additive Manufactured Bulk Metal Powders in Hot Subsonic and Supersonic Oxygen Gas

NASA Technical Reports Server (NTRS)

Tylka, Jonathan

2016-01-01

Parts produced by additive manufacturing, particularly selective laser melting (SLM), have been shown to silt metal particulate even after undergoing stringent precision aerospace cleaning processes (Lowrey 2016). As printed parts are used in oxygen systems with increased pressures, temperatures, and gas velocity, the risk of ignition by particle impact, the most common direct ignition source of metals in oxygen, substantially increases. The White Sands Test Facility (WSTF), in collaboration with Marshall Space Flight Center (MSFC), desires to test the ignitability of SLM metals by particle impact in heated oxygen. The existing test systems rely on gas velocity calculations to infer particle velocity in both subsonic and supersonic particle impact systems. Until now, it was not possible to directly measure particle velocity. To increase the fidelity of planned SLM ignition studies, it is necessary to validate that the Photon Doppler Velocimetry(PDV) test system can accurately measure particle velocity.

Dynamic Resource Allocation for IEEE802.16e

NASA Astrophysics Data System (ADS)

Nascimento, Alberto; Rodriguez, Jonathan

Mobile communications has witnessed an exponential increase in the amount of users, services and applications. New high bandwidth consuming applications are targeted for B3G networks raising more stringent requirements for Dynamic Resource Allocation (DRA) architectures and packet schedulers that must be spectrum efficient and deliver QoS for heterogeneous applications and services. In this paper we propose a new cross layer-based architecture framework embedded in a newly designed DRA architecture for the Mobile WiMAX standard. System level simulation results show that the proposed architecture can be considered a viable candidate solution for supporting mixed services in a cost-effective manner in contrast to existing approaches.

Current Technology for Thermal Protection Systems

NASA Technical Reports Server (NTRS)

Scotti, Stephen J. (Compiler)

1992-01-01

Interest in thermal protection systems for high-speed vehicles is increasing because of the stringent requirements of such new projects as the Space Exploration Initiative, the National Aero-Space Plane, and the High-Speed Civil Transport, as well as the needs for improved capabilities in existing thermal protection systems in the Space Shuttle and in turbojet engines. This selection of 13 papers from NASA and industry summarizes the history and operational experience of thermal protection systems utilized in the national space program to date, and also covers recent development efforts in thermal insulation, refractory materials and coatings, actively cooled structures, and two-phase thermal control systems.

Computer-based cognitive training for ADHD: a review of current evidence.

PubMed

Sonuga-Barke, Edmund; Brandeis, Daniel; Holtmann, Martin; Cortese, Samuele

2014-10-01

There has been an increasing interest in and the use of computer-based cognitive training as a treatment of attention-deficit/hyperactivity disorder (ADHD). The authors' review of current evidence, based partly on a stringent meta-analysis of 6 randomized controlled trials (RCTs) published in 2013, and an overview of 8 recently published RCTs highlights the inconsistency of findings between trials and across blinded and nonblinded ADHD measures within trials. Based on this, they conclude that more evidence from well-blinded studies is required before cognitive training can be supported as a frontline treatment of core ADHD symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

Disease prevalence and the index of detectability: a survey of studies of lung cancer detection by chest radiography

NASA Astrophysics Data System (ADS)

Kundel, Harold L.

2000-04-01

A survey of 12 studies of lung cancer detection with cancer prevalence ranging from 0.9 to 476 cancers per 1000 showed that the unit-slope index of detectability, d', decreased from a high value of 3.9 at low prevalence to 1.4 at high prevalence. A proposed explanation is that the readers are operating on an ROC curve with a slope that is less than unity approximating 0.6. On such a curve, a shift to more stringent criteria that occurs with decreasing prevalence in order to minimize false positives, would result in a increased unity- slope d'.

Robust Fixed-Structure Controller Synthesis

NASA Technical Reports Server (NTRS)

Corrado, Joseph R.; Haddad, Wassim M.; Gupta, Kajal (Technical Monitor)

2000-01-01

The ability to develop an integrated control system design methodology for robust high performance controllers satisfying multiple design criteria and real world hardware constraints constitutes a challenging task. The increasingly stringent performance specifications required for controlling such systems necessitates a trade-off between controller complexity and robustness. The principle challenge of the minimal complexity robust control design is to arrive at a tractable control design formulation in spite of the extreme complexity of such systems. Hence, design of minimal complexitY robust controllers for systems in the face of modeling errors has been a major preoccupation of system and control theorists and practitioners for the past several decades.

Estrogen receptor mRNA in mineralized tissues of rainbow trout: calcium mobilization by estrogen.

PubMed

Armour, K J; Lehane, D B; Pakdel, F; Valotaire, Y; Graham, R; Russell, R G; Henderson, I W

1997-07-07

RT-PCR was undertaken on total RNA extracts from bone and scales of the rainbow trout, Oncorhynchus mykiss. The rainbow trout estrogen receptor (ER)-specific primers used amplified a single product of expected size from each tissue which, using Southern blotting, strongly hybridized with a 32P-labelled rtER probe under stringent conditions. These data provide the first in vivo evidence of ER mRNA in bone and scale tissues of rainbow trout and suggest that the effects of estrogen observed in this study (increased bone mineral and decreased scale mineral contents, respectively) may be mediated directly through ER.

Tackling the x-ray cargo inspection challenge using machine learning

NASA Astrophysics Data System (ADS)

Jaccard, Nicolas; Rogers, Thomas W.; Morton, Edward J.; Griffin, Lewis D.

2016-05-01

The current infrastructure for non-intrusive inspection of cargo containers cannot accommodate exploding com-merce volumes and increasingly stringent regulations. There is a pressing need to develop methods to automate parts of the inspection workflow, enabling expert operators to focus on a manageable number of high-risk images. To tackle this challenge, we developed a modular framework for automated X-ray cargo image inspection. Employing state-of-the-art machine learning approaches, including deep learning, we demonstrate high performance for empty container verification and specific threat detection. This work constitutes a significant step towards the partial automation of X-ray cargo image inspection.

Helicopters on the asymmetric battlefield: challenges for photonics

NASA Astrophysics Data System (ADS)

Heikell, Johnny

2007-10-01

The problem set of battlefield helicopters and related photonics in asymmetric scenarios is addressed with emphasis on survivability and electronic warfare. The problem set is identified starting from an operational perspective, asking how different the asymmetric battlefield is from the traditional Cold War scenario, and by identifying relevant characteristics of battlefield helicopters. Based on this information requirements for photonics are deduced. It is concluded that the shift to asymmetric conflicts brings evolutionary-but not revolutionary-challenges for photonics, mostly so for the laser community. Main causes for the evolutionary drive are shortened engagement ranges, increased threat from ballistic and CBRE weapons, stringent ROEs, and assassination operations.

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.

Combustion and NOx emission characteristics with respect to staged-air damper opening in a 600 MWe down-fired pulverized-coal furnace under deep-air-staging conditions.

PubMed

Kuang, Min; Li, Zhengqi; Wang, Zhihua; Jing, Xinjing; Liu, Chunlong; Zhu, Qunyi; Ling, Zhongqian

2014-01-01

Deep-air-staging combustion conditions, widely used in tangential-fired and wall-arranged furnaces to significantly reduce NOx emissions, are premature up to now in down-fired furnaces that are designed especially for industry firing low-volatile coals such as anthracite and lean coal. To uncover combustion and NOx emission characteristics under deep-air-staging conditions within a newly operated 600 MWe down-fired furnace and simultaneously understand the staged-air effect on the furnace performance, full-load industrial-size measurements taken of gas temperatures and species concentrations in the furnace, CO and NOx emissions in flue gas, and carbon in fly ash were performed at various staged-air damper openings of 10%, 20%, 30%, and 50%. Increasing the staged-air damper opening, gas temperatures along the flame travel (before the flame penetrating the staged-air zone) increased initially but then decreased, while those in the staged-air zone and the upper part of the hopper continuously decreased and increased, respectively. On opening the staged-air damper to further deepen the air-staging conditions, O2 content initially decreased but then increased in both two near-wall regions affected by secondary air and staged air, respectively, whereas CO content in both two regions initially increased but then decreased. In contrast to the conventional understanding about the effects of deep-air-staging conditions, here increasing the staged-air damper opening to deepen the air-staging conditions essentially decreased the exhaust gas temperature and carbon in fly ash and simultaneously increased both NOx emissions and boiler efficiency. In light of apparently low NOx emissions and high carbon in fly ash (i.e., 696-878 mg/m(3) at 6% O2 and 9.81-13.05%, respectively) developing in the down-fired furnace under the present deep-air-staging conditions, further adjustments such as enlarging the staged-air declination angle to prolong pulverized-coal residence times in the furnace should be considered to improve the deep-air-staging combustion configuration.

Remediation of Chlorinated Solvent Plumes Using In-Situ Air Sparging—A 2-D Laboratory Study

PubMed Central

Adams, Jeffrey A.; Reddy, Krishna R.; Tekola, Lue

2011-01-01

In-situ air sparging has evolved as an innovative technique for soil and groundwater remediation impacted with volatile organic compounds (VOCs), including chlorinated solvents. These may exist as non-aqueous phase liquid (NAPL) or dissolved in groundwater. This study assessed: (1) how air injection rate affects the mass removal of dissolved phase contamination, (2) the effect of induced groundwater flow on mass removal and air distribution during air injection, and (3) the effect of initial contaminant concentration on mass removal. Dissolved-phase chlorinated solvents can be effectively removed through the use of air sparging; however, rapid initial rates of contaminant removal are followed by a protracted period of lower removal rates, or a tailing effect. As the air flow rate increases, the rate of contaminant removal also increases, especially during the initial stages of air injection. Increased air injection rates will increase the density of air channel formation, resulting in a larger interfacial mass transfer area through which the dissolved contaminant can partition into the vapor phase. In cases of groundwater flow, increased rates of air injection lessened observed downward contaminant migration effect. The air channel network and increased air saturation reduced relative hydraulic conductivity, resulting in reduced groundwater flow and subsequent downgradient contaminant migration. Finally, when a higher initial TCE concentration was present, a slightly higher mass removal rate was observed due to higher volatilization-induced concentration gradients and subsequent diffusive flux. Once concentrations are reduced, a similar tailing effect occurs. PMID:21776228

Remediation of chlorinated solvent plumes using in-situ air sparging--a 2-D laboratory study.

PubMed

Adams, Jeffrey A; Reddy, Krishna R; Tekola, Lue

2011-06-01

In-situ air sparging has evolved as an innovative technique for soil and groundwater remediation impacted with volatile organic compounds (VOCs), including chlorinated solvents. These may exist as non-aqueous phase liquid (NAPL) or dissolved in groundwater. This study assessed: (1) how air injection rate affects the mass removal of dissolved phase contamination, (2) the effect of induced groundwater flow on mass removal and air distribution during air injection, and (3) the effect of initial contaminant concentration on mass removal. Dissolved-phase chlorinated solvents can be effectively removed through the use of air sparging; however, rapid initial rates of contaminant removal are followed by a protracted period of lower removal rates, or a tailing effect. As the air flow rate increases, the rate of contaminant removal also increases, especially during the initial stages of air injection. Increased air injection rates will increase the density of air channel formation, resulting in a larger interfacial mass transfer area through which the dissolved contaminant can partition into the vapor phase. In cases of groundwater flow, increased rates of air injection lessened observed downward contaminant migration effect. The air channel network and increased air saturation reduced relative hydraulic conductivity, resulting in reduced groundwater flow and subsequent downgradient contaminant migration. Finally, when a higher initial TCE concentration was present, a slightly higher mass removal rate was observed due to higher volatilization-induced concentration gradients and subsequent diffusive flux. Once concentrations are reduced, a similar tailing effect occurs.

Response of Arctic Temperature to Changes in Emissions of Short-Lived Climate Forcers

NASA Astrophysics Data System (ADS)

Sand, M.; Berntsen, T.; von Salzen, K.; Flanner, M.; Langner, J.; Victor, D. G.

2015-12-01

There is growing scientific and political interest in the impacts of climate change and anthropogenic emissions on the Arctic. Over recent decades temperatures in the Arctic have increased twice the global rate, largely due to ice albedo and temperature feedbacks. While deep cuts in global CO2 emissions are required to slow this warming, there is also growing interest in the potential for reducing short lived climate forcers (SLCFs). Politically, action on SLCFs may be particularly promising because the benefits of mitigation appear promptly and there are large co-benefits in terms of improved air quality. This study is the first to systematically quantify the Arctic climate impact of regional SLCF emissions, taking into account BC, sulphur dioxide (SO2), nitrogen oxides (NOx), volatile hydrocarbons (VOC), organic carbon (OC) and tropospheric ozone, their transport processes and transformations in the atmosphere. Using several chemical transport models we perform detailed radiative forcing calculations from emissions of these species. Geographically we separate emissions into seven source regions that correspond with the national groupings of the Arctic Council, the leading body organizing international policy in the region (the United States, Canada, the Nordic countries, the rest of Europe, Russia, East and South Asia, and the rest of the world). We look at six main sectors known to account for [nearly all] of these emissions: households (domestic), energy/industry/waste, transport, agricultural fires, grass/forest fires, and gas flaring. We find that the largest Arctic warming source is from emissions within the Asian nations. However, the Arctic is most sensitive, per unit mass emitted, to SLCFs emissions from a small number of activities within the Arctic nations themselves. A stringent, but technically feasible SLCFs mitigation scenario, phased in from 2015 through 2030, can cut warming by 0.2 K in 2050.

Response of Arctic Temperature to Changes in Emissions of Short-Lived Climate Forcers

NASA Astrophysics Data System (ADS)

Sand, M.; Berntsen, T.; von Salzen, K.; Flanner, M.; Langner, J.; Victor, D. G.

2014-12-01

There is growing scientific and political interest in the impacts of climate change and anthropogenic emissions on the Arctic. Over recent decades temperatures in the Arctic have increased twice the global rate, largely due to ice albedo and temperature feedbacks. While deep cuts in global CO2 emissions are required to slow this warming, there is also growing interest in the potential for reducing short lived climate forcers (SLCFs). Politically, action on SLCFs may be particularly promising because the benefits of mitigation appear promptly and there are large co-benefits in terms of improved air quality. This study is the first to systematically quantify the Arctic climate impact of regional SLCF emissions, taking into account BC, sulphur dioxide (SO2), nitrogen oxides (NOx), volatile hydrocarbons (VOC), organic carbon (OC) and tropospheric ozone, their transport processes and transformations in the atmosphere. Using several chemical transport models we perform detailed radiative forcing calculations from emissions of these species. Geographically we separate emissions into seven source regions that correspond with the national groupings of the Arctic Council, the leading body organizing international policy in the region (the United States, Canada, the Nordic countries, the rest of Europe, Russia, East and South Asia, and the rest of the world). We look at six main sectors known to account for [nearly all] of these emissions: households (domestic), energy/industry/waste, transport, agricultural fires, grass/forest fires, and gas flaring. We find that the largest Arctic warming source is from emissions within the Asian nations. However, the Arctic is most sensitive, per unit mass emitted, to SLCFs emissions from a small number of activities within the Arctic nations themselves. A stringent, but technically feasible SLCFs mitigation scenario, phased in from 2015 through 2030, can cut warming by 0.2 K in 2050.

NASA's Aeroacoustic Tools and Methods for Analysis of Aircraft Noise

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Lopes, Leonard V.; Burley, Casey L.

2015-01-01

Aircraft community noise is a significant concern due to continued growth in air traffic, increasingly stringent environmental goals, and operational limitations imposed by airport authorities. The ability to quantify aircraft noise at the source and ultimately at observers is required to develop low noise aircraft designs and flight procedures. Predicting noise at the source, accounting for scattering and propagation through the atmosphere to the observer, and assessing the perception and impact on a community requires physics-based aeroacoustics tools. Along with the analyses for aero-performance, weights and fuel burn, these tools can provide the acoustic component for aircraft MDAO (Multidisciplinary Design Analysis and Optimization). Over the last decade significant progress has been made in advancing the aeroacoustic tools such that acoustic analyses can now be performed during the design process. One major and enabling advance has been the development of the system noise framework known as Aircraft NOise Prediction Program2 (ANOPP2). ANOPP2 is NASA's aeroacoustic toolset and is designed to facilitate the combination of acoustic approaches of varying fidelity for the analysis of noise from conventional and unconventional aircraft. The toolset includes a framework that integrates noise prediction and propagation methods into a unified system for use within general aircraft analysis software. This includes acoustic analyses, signal processing and interfaces that allow for the assessment of perception of noise on a community. ANOPP2's capability to incorporate medium fidelity shielding predictions and wind tunnel experiments into a design environment is presented. An assessment of noise from a conventional and Hybrid Wing Body (HWB) aircraft using medium fidelity scattering methods combined with noise measurements from a model-scale HWB recently placed in NASA's 14x22 wind tunnel are presented. The results are in the form of community noise metrics and auralizations.

Using radiocarbon to constrain black and organic carbon aerosol sources in Salt Lake City

NASA Astrophysics Data System (ADS)

Mouteva, Gergana O.; Randerson, James T.; Fahrni, Simon M.; Bush, Susan E.; Ehleringer, James R.; Xu, Xiaomei; Santos, Guaciara M.; Kuprov, Roman; Schichtel, Bret A.; Czimczik, Claudia I.

2017-09-01

Black carbon (BC) and organic carbon (OC) aerosols are important components of fine particulate matter (PM2.5) in polluted urban environments. Quantifying the contribution of fossil fuel and biomass combustion to BC and OC concentrations is critical for developing and validating effective air quality control measures and climate change mitigation policy. We used radiocarbon (14C) to measure fossil and contemporary biomass contributions to BC and OC at three locations in Salt Lake City, Utah, USA, during 2012-2014, including during winter inversion events. Aerosol filters were analyzed with the Swiss_4S thermal-optical protocol to isolate BC. We measured fraction modern (fM) of BC and total carbon in PM2.5 with accelerator mass spectrometry and derived the fM of OC using isotope mass balance. Combined with 14C information of end-member composition, our data set of 31 14C aerosol measurements provided a baseline of the fossil and contemporary biomass components of carbonaceous aerosol. We show that fossil fuels were the dominant source of carbonaceous aerosol during winter, contributing 88% (80-98%) of BC and 58% (48-69%) of OC. While the concentration of both BC and OC increased during inversion events, the relative source contributions did not change. The sources of BC also did not vary throughout the year, while OC had a considerably higher contemporary biomass component in summer at 62% (49-76%) and was more variable. Our results suggest that in order to reduce PM2.5 levels in Salt Lake City to meet national standards, a more stringent policy targeting mobile fossil fuel sources may be necessary.

Cosmetic tourism: public opinion and analysis of information and content available on the Internet.

PubMed

Nassab, Reza; Hamnett, Nathan; Nelson, Kate; Kaur, Simranjit; Greensill, Beverley; Dhital, Sanjiv; Juma, Ali

2010-01-01

The medical tourism market is a rapidly growing sector fueled by increasing health care costs, longer domestic waiting times, economic recession, and cheaper air travel. The authors investigate public opinion on undergoing cosmetic surgery abroad and then explore the information patients are likely to encounter on the Internet when searching for such services. A poll of 197 members of the general public was conducted in the United Kingdom. An Internet search including the terms plastic surgery abroad was conducted, and the first 100 relevant sites were reviewed. Of the 197 respondents, 47% had considered having some form of cosmetic surgery. Most (97%) would consider going abroad for their procedure. The Internet was a source of information for 70%. The review of the first 100 sites under "plastic surgery abroad" revealed that most centers were located in Eastern Europe (26%), South America (14%), and the Far East (11%). Exploring the information provided on the Web sites, we found 37% contained no information regarding procedures. Only 10% of sites contained any information about potential complications. Even less frequently mentioned (4%) were details of aftercare or follow-up procedures. The authors found that the overwhelming majority of respondents considering plastic surgery would also consider seeking cosmetic surgical treatment abroad. The Internet sites that appear most prominently in an online search contained a distinct lack of information for potential patients, particularly with regard to complications and aftercare. There is, therefore, a need for improved public awareness and education about the considerations inherent in medical tourism. The introduction of more stringent regulations for international centers providing such services should also be considered to help safeguard patients.

Using avian surveillance in Ecuador to assess the imminence of West Nile virus incursion to Galápagos.

PubMed

Eastwood, Gillian; Goodman, Simon J; Hilgert, Nancy; Cruz, Marilyn; Kramer, Laura D; Cunningham, Andrew A

2014-01-01

Infectious disease emergence represents a global threat to human, agricultural animal and wildlife health. West Nile virus (WNV) first emerged in the Americas in 1999 following its introduction to New York from the Old World. This flavivirus rapidly spread across much of North America, causing human, equine and avian mortalities and population declines of multiple wild bird species. It has now spread to Central and South America, and there is concern that the virus will reach the Galápagos Islands, a UNESCO World Heritage Site famous for its unique biodiversity, with potentially catastrophic results. Here, we use wild bird surveillance to examine the current WNV status in the Galapagos Islands and around the Ecuadorian city of Guayaquil (the main air and sea port serving Galápagos). We conducted serosurveys of wild birds on three Galápagos Islands (Baltra, San Cristobal and Santa Cruz) with direct transport links to the South American continent. In addition, dead birds killed by car collisions on Santa Cruz were tested for WNV infection. On mainland Ecuador, serosurveys of wild birds were conducted at three sites around Guayaquil. No evidence of WNV seropositivity or infection was detected. Although wider testing is recommended on the mainland, the study highlights a limit of WNV spread within South America. Our results indicate the continued absence of WNV on Galápagos and suggest the current likelihood of human-mediated transport of WNV to Galápagos to be low. The risk of emergence will almost certainly increase over time, however, and stringent biosecurity and surveillance measures should be put in place to minimise the risk of the introduction of WNV (and other alien pathogens) to Galápagos.

Pegasus hypersonic flight research

NASA Technical Reports Server (NTRS)

Curry, Robert E.; Meyer, Robert R., Jr.; Budd, Gerald D.

1992-01-01

Hypersonic aeronautics research using the Pegasus air-launched space booster is described. Two areas are discussed in the paper: previously obtained results from Pegasus flights 1 and 2, and plans for future programs. Proposed future research includes boundary-layer transition studies on the airplane-like first stage and also use of the complete Pegasus launch system to boost a research vehicle to hypersonic speeds. Pegasus flight 1 and 2 measurements were used to evaluate the results of several analytical aerodynamic design tools applied during the development of the vehicle as well as to develop hypersonic flight-test techniques. These data indicated that the aerodynamic design approach for Pegasus was adequate and showed that acceptable margins were available. Additionally, the correlations provide insight into the capabilities of these analytical tools for more complex vehicles in which design margins may be more stringent. Near-term plans to conduct hypersonic boundary-layer transition studies are discussed. These plans involve the use of a smooth metallic glove at about the mid-span of the wing. Longer-term opportunities are proposed which identify advantages of the Pegasus launch system to boost large-scale research vehicles to the real-gas hypersonic flight regime.

Compression Ignition Engines – Revolutionary Technology That has Civilized Frontiers all Over the Globe from the Industrial Revolution into the Twenty-First Century

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

Ciatti, Stephen A.

The history, present and future of the compression ignition engine is a fascinating story that spans over 100 years, from the time of Rudolf Diesel to the highly regulated and computerized engines of the 21st Century. The development of these engines provided inexpensive, reliable and high power density machines to allow transportation, construction and farming to be more productive with less human effort than in any previous period of human history. The concept that fuels could be consumed efficiently and effectively with only the ignition of pressurized and heated air was a significant departure from the previous coal-burning architecture ofmore » the 1800s. Today, the compression ignition engine is undergoing yet another revolution. The equipment that provides transport, builds roads and infrastructure, and harvests the food we eat needs to meet more stringent requirements than ever before. How successfully 21st Century engineers are able to make compression ignition engine technology meet these demands will be of major influence in assisting developing nations (with over 50% of the world’s population) achieve the economic and environmental goals they seek.« less

Spectral purity study for IPDA lidar measurement of CO2

NASA Astrophysics Data System (ADS)

Ma, Hui; Liu, Dong; Xie, Chen-Bo; Tan, Min; Deng, Qian; Xu, Ji-Wei; Tian, Xiao-Min; Wang, Zhen-Zhu; Wang, Bang-Xin; Wang, Ying-Jian

2018-02-01

A high sensitivity and global covered observation of carbon dioxide (CO2) is expected by space-borne integrated path differential absorption (IPDA) lidar which has been designed as the next generation measurement. The stringent precision of space-borne CO2 data, for example 1ppm or better, is required to address the largest number of carbon cycle science questions. Spectral purity, which is defined as the ratio of effective absorbed energy to the total energy transmitted, is one of the most important system parameters of IPDA lidar which directly influences the precision of CO2. Due to the column averaged dry air mixing ratio of CO2 is inferred from comparison of the two echo pulse signals, the laser output usually accompanied by an unexpected spectrally broadband background radiation would posing significant systematic error. In this study, the spectral energy density line shape and spectral impurity line shape are modeled as Lorentz line shape for the simulation, and the latter is assumed as an unabsorbed component by CO2. An error equation is deduced according to IPDA detecting theory for calculating the system error caused by spectral impurity. For a spectral purity of 99%, the induced error could reach up to 8.97 ppm.

PM, NOx and butane emissions from on-road vehicle fleets in Hong Kong and their implications on emission control policy

NASA Astrophysics Data System (ADS)

Ning, Zhi; Wubulihairen, Maimaitireyimu; Yang, Fenhuan

2012-12-01

Vehicular emissions are the major sources of air pollution in urban areas. For metropolitan cities with large population working and living in environments with direct traffic impact, emission control is of great significance to protect public health. Implementation of more stringent emission standards, retrofitting fleet with emission control devices and switching to clearer fuel has been commonly practiced in different cities including Hong Kong. The present study employed a new plume chasing method for effective and quick evaluation of on-road fleet emission factors of particulate matter (PM), nitrogen oxides (NOx), and butane from heavy duty diesel trucks, diesel buses and liquefied petroleum gas (LPG) vehicles. The results showed distinct profiles of the emissions from different fleets with excessive butane emissions from LPG fleet and contrasting PM and NOx emissions from diesel trucks and buses fleets. A cross comparison was also made with emission data from other cities and from historic local studies. The implications of the observed difference on the effectiveness of emission control measures and policy are discussed with recommendations of direction for future research and policy making.

Ultra Low Outgassing silicone performance in a simulated space ionizing radiation environment

NASA Astrophysics Data System (ADS)

Velderrain, M.; Malave, V.; Taylor, E. W.

2010-09-01

The improvement of silicone-based materials used in space and aerospace environments has garnered much attention for several decades. Most recently, an Ultra Low Outgassing™ silicone incorporating innovative reinforcing and functional fillers has shown that silicone elastomers with unique and specific properties can be developed to meet applications requiring stringent outgassing requirements. This paper will report on the next crucial step in qualifying these materials for spacecraft applications requiring chemical and physical stability in the presence of ionizing radiation. As a first step in this process, selected materials were irradiated with Co-60 gamma-rays to simulate the total dose received in near- Earth orbits. The paper will present pre-and post-irradiation response data of Ultra Low Outgassing silicone samples exposed under ambient air environment coupled with measurements of collected volatile condensable material (CVCM) and total mass loss (TML) per the standard conditions in ASTM E 595. The data will show an insignificant effect on the CVCMs and TMLs after exposure to various dosages of gamma radiation. This data may favorably impact new applications for these silicone materials for use as an improved sealant for space solar cell systems, space structures, satellite systems and aerospace systems.

Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1978-01-01

A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

Search for neutrinos from dark matter self-annihilations in the center of the Milky Way with 3 years of IceCube/DeepCore: IceCube Collaboration

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

Aartsen, M. G.; Ackermann, M.; Adams, J.

Here, we present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles < σ A v>. We then set the upper limits for dark matter particle candidate masses ranging from 10 GeV up to 1 TeV while considering annihilation throughmore » multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100 GeV, with a limit of 1.18·10 -23cm 3s -1 for 100 GeV dark matter particles self-annihilating via τ + τ - to neutrinos (assuming the Navarro–Frenk–White dark matter halo profile).« less

Search for neutrinos from dark matter self-annihilations in the center of the Milky Way with 3 years of IceCube/DeepCore: IceCube Collaboration

DOE PAGES

Aartsen, M. G.; Ackermann, M.; Adams, J.; ...

2017-09-20

Here, we present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles < σ A v>. We then set the upper limits for dark matter particle candidate masses ranging from 10 GeV up to 1 TeV while considering annihilation throughmore » multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100 GeV, with a limit of 1.18·10 -23cm 3s -1 for 100 GeV dark matter particles self-annihilating via τ + τ - to neutrinos (assuming the Navarro–Frenk–White dark matter halo profile).« less

Performance evaluation of an advanced air-fuel ratio controller on a stationary, rich-burn natural gas engine

NASA Astrophysics Data System (ADS)

Kochuparampil, Roshan Joseph

The advent of an era of abundant natural gas is making it an increasingly economical fuel source against incumbents such as crude oil and coal, in end-use sectors such as power generation, transportation and industrial chemical production, while also offering significant environmental benefits over these incumbents. Equipment manufacturers, in turn, are responding to widespread demand for power plants optimized for operation with natural gas. In several applications such as distributed power generation, gas transmission, and water pumping, stationary, spark-ignited, natural gas fueled internal combustion engines (ICEs) are the power plant of choice (over turbines) owing to their lower equipment and operational costs, higher thermal efficiencies across a wide load range, and the flexibility afforded to end-users when building fine-resolution horsepower topologies: modular size increments ranging from 100 kW -- 2 MW per ICE power plant compared to 2 -- 5 MW per turbine power plant. Under the U.S. Environment Protection Agency's (EPA) New Source Performance Standards (NSPS) and Reciprocating Internal Combustion Engine National Emission Standards for Hazardous Air Pollutants (RICE NESHAP) air quality regulations, these natural gas power plants are required to comply with stringent emission limits, with several states mandating even stricter emissions norms. In the case of rich-burn or stoichiometric natural gas ICEs, very high levels of sustained emissions reduction can be achieved through exhaust after-treatment that utilizes Non Selective Catalyst Reduction (NSCR) systems. The primary operational constraint with these systems is the tight air-fuel ratio (AFR) window of operation that needs to be maintained if the NSCR system is to achieve simultaneous reduction of carbon monoxide (CO), nitrogen oxides (NOx), total hydrocarbons (THC), volatile organic compounds (VOCs), and formaldehyde (CH 2O). Most commercially available AFR controllers utilizing lambda (oxygen) sensor feedback are unable to maintain engine AFR within the required range owing to drift in sensor output over time. In this thesis, the emissions compliance performance of an AFR controller is evaluated over a 6-month period on an engine driving a gas compressor in an active natural gas production field. This AFR controller differentiates itself from other commercially available products by employing a lambda sensor that has been engineered against sensor drift, making it better suited for natural gas engine applications. Also included in this study are the controller's responses to transient loads, diurnal performance, adaptability to seasonal variations in ambient temperature, fuel quality variations (in wellhead gas), engine health considerations for proper AFR control, and controller calibration sensitivity when replacing lambda sensors. During the first three months of operation and subsequent diurnal tests, the controller's performance as a multi-point AFR control system was consistent, demonstrating appropriate AFR adjustments to variation in engine operation, over a wide range of ambient conditions, despite high consumption rate of engine lubrication oil. For the remainder the test, the high levels of lubrication oil consumption, compromised the ability to verify controller performance.

Reliability of unstable periodic orbit based control strategies in biological systems.

PubMed

Mishra, Nagender; Hasse, Maria; Biswal, B; Singh, Harinder P

2015-04-01

Presence of recurrent and statistically significant unstable periodic orbits (UPOs) in time series obtained from biological systems is now routinely used as evidence for low dimensional chaos. Extracting accurate dynamical information from the detected UPO trajectories is vital for successful control strategies that either aim to stabilize the system near the fixed point or steer the system away from the periodic orbits. A hybrid UPO detection method from return maps that combines topological recurrence criterion, matrix fit algorithm, and stringent criterion for fixed point location gives accurate and statistically significant UPOs even in the presence of significant noise. Geometry of the return map, frequency of UPOs visiting the same trajectory, length of the data set, strength of the noise, and degree of nonstationarity affect the efficacy of the proposed method. Results suggest that establishing determinism from unambiguous UPO detection is often possible in short data sets with significant noise, but derived dynamical properties are rarely accurate and adequate for controlling the dynamics around these UPOs. A repeat chaos control experiment on epileptic hippocampal slices through more stringent control strategy and adaptive UPO tracking is reinterpreted in this context through simulation of similar control experiments on an analogous but stochastic computer model of epileptic brain slices. Reproduction of equivalent results suggests that far more stringent criteria are needed for linking apparent success of control in such experiments with possible determinism in the underlying dynamics.

Stringent or nonstringent complete remission and prognosis in acute myeloid leukemia: a Danish population-based study

PubMed Central

Øvlisen, Andreas K.; Oest, Anders; Bendtsen, Mette D.; Bæch, John; Johansen, Preben; Lynggaard, Line S.; Mølle, Ingolf; Mortensen, Thomas B.; Weber, Duruta; Ertner, Gideon; Schöllkopf, Claudia; Thomassen, Jesper Q.; Nielsen, Ove Juul; Østgård, Lene Sofie Granfeldt; Bøgsted, Martin; Dybkær, Karen; Johnsen, Hans E.

2018-01-01

Stringent complete remission (sCR) of acute myeloid leukemia is defined as normal hematopoiesis after therapy. Less sCR, including non-sCR, was introduced as insufficient blood platelet, neutrophil, or erythrocyte recovery. These latter characteristics were defined retrospectively as postremission transfusion dependency and were suggested to be of prognostic value. In the present report, we evaluated the prognostic impact of achieving sCR and non-sCR in the Danish National Acute Leukaemia Registry, including 769 patients registered with classical CR (ie, <5% blasts in the postinduction bone marrow analysis). Individual patients were classified as having sCR (n = 360; 46.8%) or non-sCR (n = 409; 53.2%) based on data from our national laboratory and transfusion databases. Survival analysis revealed that patients achieving sCR had superior overall survival (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.10-1.64) as well as relapse-free survival (HR, 1.25; 95% CI, 1.03-1.51) compared with those with non-sCR after adjusting for covariates. Cox regression analysis regarding the impact of the stringent criteria for blood cell recovery identified these as significant and independent variables. In conclusion, this real-life register study supports the international criteria for response evaluation on prognosis and, most importantly, documents each of the 3 lineage recovery criteria as contributing independently. PMID:29523528

Reliability of unstable periodic orbit based control strategies in biological systems

NASA Astrophysics Data System (ADS)

Mishra, Nagender; Hasse, Maria; Biswal, B.; Singh, Harinder P.

2015-04-01

Presence of recurrent and statistically significant unstable periodic orbits (UPOs) in time series obtained from biological systems is now routinely used as evidence for low dimensional chaos. Extracting accurate dynamical information from the detected UPO trajectories is vital for successful control strategies that either aim to stabilize the system near the fixed point or steer the system away from the periodic orbits. A hybrid UPO detection method from return maps that combines topological recurrence criterion, matrix fit algorithm, and stringent criterion for fixed point location gives accurate and statistically significant UPOs even in the presence of significant noise. Geometry of the return map, frequency of UPOs visiting the same trajectory, length of the data set, strength of the noise, and degree of nonstationarity affect the efficacy of the proposed method. Results suggest that establishing determinism from unambiguous UPO detection is often possible in short data sets with significant noise, but derived dynamical properties are rarely accurate and adequate for controlling the dynamics around these UPOs. A repeat chaos control experiment on epileptic hippocampal slices through more stringent control strategy and adaptive UPO tracking is reinterpreted in this context through simulation of similar control experiments on an analogous but stochastic computer model of epileptic brain slices. Reproduction of equivalent results suggests that far more stringent criteria are needed for linking apparent success of control in such experiments with possible determinism in the underlying dynamics.

An investigation on the effects of air on electron energy in atmospheric pressure helium plasma jets

NASA Astrophysics Data System (ADS)

Liu, Yadi; Tan, Zhenyu; Chen, Xinxian; Li, Xiaotong; Zhang, Huimin; Pan, Jie; Wang, Xiaolong

2018-03-01

In this work, the effects of air on electron energy in the atmospheric pressure helium plasma jet produced by a needle-plane discharge system have been investigated by means of the numerical simulation based on a two-dimensional fluid model, and the air concentration dependences of the reactive species densities have also been calculated. In addition, the synergistic effects of the applied voltage and air concentration on electron energy have been explored. The present work gives the following significant results. For a fixed applied voltage, the averaged electron energy is basically a constant at air concentrations below about 0.5%, but it evidently decreases above the concentration of 0.5%. Furthermore, the averaged densities of four main reactive species O, O(1D), O2(1Δg), and N2(A3Σu+) increase with the increasing air concentration, but the increase becomes slow at air concentrations above 0.5%. The air concentration dependences of the averaged electron energy under different voltage amplitudes are similar, and for a given air concentration, the averaged electron energy increases with the increase in the voltage amplitude. For the four reactive species, the effects of the air concentration on their averaged densities are similar for a given voltage amplitude. In addition, the averaged densities of the four reactive species increase with increasing voltage amplitude for a fixed air concentration. The present work suggests that a combination of high voltage amplitude and the characteristic air concentration, 0.5% in the present discharge system, allows an expected electron energy and also generates abundant reactive species.

EnzDP: improved enzyme annotation for metabolic network reconstruction based on domain composition profiles.

PubMed

Nguyen, Nam-Ninh; Srihari, Sriganesh; Leong, Hon Wai; Chong, Ket-Fah

2015-10-01

Determining the entire complement of enzymes and their enzymatic functions is a fundamental step for reconstructing the metabolic network of cells. High quality enzyme annotation helps in enhancing metabolic networks reconstructed from the genome, especially by reducing gaps and increasing the enzyme coverage. Currently, structure-based and network-based approaches can only cover a limited number of enzyme families, and the accuracy of homology-based approaches can be further improved. Bottom-up homology-based approach improves the coverage by rebuilding Hidden Markov Model (HMM) profiles for all known enzymes. However, its clustering procedure relies firmly on BLAST similarity score, ignoring protein domains/patterns, and is sensitive to changes in cut-off thresholds. Here, we use functional domain architecture to score the association between domain families and enzyme families (Domain-Enzyme Association Scoring, DEAS). The DEAS score is used to calculate the similarity between proteins, which is then used in clustering procedure, instead of using sequence similarity score. We improve the enzyme annotation protocol using a stringent classification procedure, and by choosing optimal threshold settings and checking for active sites. Our analysis shows that our stringent protocol EnzDP can cover up to 90% of enzyme families available in Swiss-Prot. It achieves a high accuracy of 94.5% based on five-fold cross-validation. EnzDP outperforms existing methods across several testing scenarios. Thus, EnzDP serves as a reliable automated tool for enzyme annotation and metabolic network reconstruction. Available at: www.comp.nus.edu.sg/~nguyennn/EnzDP .

Statistical learning of movement.

PubMed

Ongchoco, Joan Danielle Khonghun; Uddenberg, Stefan; Chun, Marvin M

2016-12-01

The environment is dynamic, but objects move in predictable and characteristic ways, whether they are a dancer in motion, or a bee buzzing around in flight. Sequences of movement are comprised of simpler motion trajectory elements chained together. But how do we know where one trajectory element ends and another begins, much like we parse words from continuous streams of speech? As a novel test of statistical learning, we explored the ability to parse continuous movement sequences into simpler element trajectories. Across four experiments, we showed that people can robustly parse such sequences from a continuous stream of trajectories under increasingly stringent tests of segmentation ability and statistical learning. Observers viewed a single dot as it moved along simple sequences of paths, and were later able to discriminate these sequences from novel and partial ones shown at test. Observers demonstrated this ability when there were potentially helpful trajectory-segmentation cues such as a common origin for all movements (Experiment 1); when the dot's motions were entirely continuous and unconstrained (Experiment 2); when sequences were tested against partial sequences as a more stringent test of statistical learning (Experiment 3); and finally, even when the element trajectories were in fact pairs of trajectories, so that abrupt directional changes in the dot's motion could no longer signal inter-trajectory boundaries (Experiment 4). These results suggest that observers can automatically extract regularities in movement - an ability that may underpin our capacity to learn more complex biological motions, as in sport or dance.

Characterizing the effects of inorganic acid and alkaline shock on the Staphylococcus aureus transcriptome and messenger RNA turnover.

PubMed

Anderson, Kelsi L; Roux, Christelle M; Olson, Matthew W; Luong, Thanh T; Lee, Chia Y; Olson, Robert; Dunman, Paul M

2010-12-01

Staphylococcus aureus pathogenesis can be attributed partially to its ability to adapt to otherwise deleterious host-associated stresses. Here, Affymetrix GeneChips® were used to examine the S. aureus responses to inorganic acid and alkaline shock and to assess whether stress-dependent changes in mRNA turnover are likely to facilitate the organism's ability to tolerate a pH challenge. The results indicate that S. aureus adapts to pH shock by eliciting responses expected of cells coping with pH alteration, including neutralizing cellular pH, DNA repair, amino acid biosynthesis, and virulence factor expression. Further, the S. aureus response to alkaline conditions is strikingly similar to that of stringent response-induced cells. Indeed, we show that alkaline shock stimulates the accumulation of the stringent response activator (p)ppGpp. The results also revealed that pH shock significantly alters the mRNA properties of the cell. A comparison of the mRNA degradation properties of transcripts whose titers either increased or decreased in response to a sudden pH change revealed that alterations in mRNA degradation may, in part, account for the changes in the mRNA levels of factors predicted to mediate pH tolerance. A set of small stable RNA molecules were induced in response to acid- or alkaline-shock conditions and may mediate adaptation to pH stress. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Controlled breathing protocols probe human autonomic cardiovascular rhythms

NASA Technical Reports Server (NTRS)

Cooke, W. H.; Cox, J. F.; Diedrich, A. M.; Taylor, J. A.; Beightol, L. A.; Ames, J. E. 4th; Hoag, J. B.; Seidel, H.; Eckberg, D. L.

1998-01-01

The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0.1, and 0.05 Hz for 2 min each); 3) stepwise frequency breathing as above, but with prescribed tidal volumes; 4) random-frequency breathing (approximately 0.5-0.05 Hz) for 6 min; and 5) fixed-frequency breathing (0.25 Hz) for 5 min. During stepwise breathing, R-R interval and arterial pressure spectral power increased as breathing frequency decreased. Control of inspired volume reduced R-R interval spectral power during 0.1 Hz breathing (P < 0.05). Stepwise and random-breathing protocols yielded comparable coherence and transfer functions between respiration and R-R intervals and systolic pressure and R-R intervals. Random- and fixed-frequency breathing reduced end-tidal CO2 modestly (P < 0.05). Our data suggest that stringent tidal volume control attenuates low-frequency R-R interval oscillations and that fixed- and random-rate breathing may decrease CO2 chemoreceptor stimulation. We conclude that autonomic rhythms measured during different breathing protocols have much in common but that a stepwise protocol without stringent control of inspired volume may allow for the most efficient assessment of short-term respiratory-mediated autonomic oscillations.

40 CFR 35.2015 - State priority system and project priority list.

Code of Federal Regulations, 2014 CFR

2014-07-01

... I); (B) Treatment more stringent than secondary (category II); (C) Infiltration/inflow correction... cost-effective alternative; (C) New interceptors and appurtenances; and (D) Infiltration/inflow...

40 CFR 35.2015 - State priority system and project priority list.

Code of Federal Regulations, 2013 CFR

2013-07-01

... I); (B) Treatment more stringent than secondary (category II); (C) Infiltration/inflow correction... cost-effective alternative; (C) New interceptors and appurtenances; and (D) Infiltration/inflow...

40 CFR 35.2015 - State priority system and project priority list.

Code of Federal Regulations, 2011 CFR

2011-07-01

... I); (B) Treatment more stringent than secondary (category II); (C) Infiltration/inflow correction... cost-effective alternative; (C) New interceptors and appurtenances; and (D) Infiltration/inflow...

40 CFR 35.2015 - State priority system and project priority list.

Code of Federal Regulations, 2012 CFR

2012-07-01

... I); (B) Treatment more stringent than secondary (category II); (C) Infiltration/inflow correction... cost-effective alternative; (C) New interceptors and appurtenances; and (D) Infiltration/inflow...

Insomnia and hypnotic medications are associated with suicidal ideation in a community population.

PubMed

Pigeon, Wilfred R; Woosley, Julie A; Lichstein, Kenneth L

2014-01-01

Suicidal ideation (SI), a significant predictor of suicide, is associated with sleep disturbance, which is seldom assessed using stringent diagnostic criteria and validated sleep instruments in community samples. Cross-sectional data, including sleep diaries and validated instruments, from 767 community adults were used to identify variables associated with SI and subsequently entered into a regression model to predict SI. Suicidal ideation was endorsed by 9.3% of the sample. This group differed from non-ideators on several variables, but only insomnia diagnosis, depression severity, and hypnotic medication use predicted SI. Findings confirm an association of insomnia with SI using stringent criteria and controlling for depression. If treating insomnia is a conceivable pathway to reduce SI, the apparent risk posed by hypnotics may limit treatment options.

Exploring Organizational Smoking Policies and Employee Vaping Behavior.

PubMed

Song, Xiaochuan; English, Master Thomas M; Whitman, Marilyn V

2017-04-01

Cigarette consumption has become global threat to both smokers and organizations. However, little is known about organizational smoking and vaping policies, and their influence to employees' smoking and vaping behavior. We collected data from 456 employed smokers, vapers, and/or dual users. Smoking and/or vaping behavior, along with perceived organizational smoking/vaping policies were examined. Vapers reported perceiving more stringent smoking policy, while vapers who reported having workplace vaping policies perceived having generally more stringent vaping policy. Most smokers and vapers are well informed about smoking policy; however, a considerable portion of them do not have a good understanding about organizational vaping policy. Organizations should not consider smoking and vaping to be the same when setting policy. Employers should ensure that organizational vaping policies are present and clear to all employees.

The Influence of Directed Air Flow on Combustion in Spark-Ignition Engine

NASA Technical Reports Server (NTRS)

Rothrock, A M; Spencer, R C

1939-01-01

The air movement within the cylinder of the NACA combustion apparatus was regulated by using shrouded inlet valves and by fairing the inlet passage. Rates of combustion were determined at different inlet-air velocities with the engine speed maintained constant and at different engine speeds with the inlet-air velocity maintained approximately constant. The rate of combustion increased when the engine speed was doubled without changing the inlet-air velocity; the observed increase was about the same as the increase in the rate of combustion obtained by doubling the inlet-air velocity without changing the engine speed. Certain types of directed air movement gave great improvement in the reproducibility of the explosions from cycle to cycle, provided that other variables were controlled. Directing the inlet air past the injection valve during injection increased the rate of burning.

Air gun wounding and current UK laws controlling air weapons.

PubMed

Bruce-Chwatt, Robert Michael

2010-04-01

Air weapons whether rifles or pistols are, potentially, lethal weapons. The UK legislation is complex and yet little known to the public. Hunting with air weapons and the laws controlling those animals that are permitted to be shot with air weapons is even more labyrinthine due to the legal power limitations on the possession of air weapons. Still relatively freely available by mail order or on the Internet, an increasing number of deaths have been reported from the misuse of air weapons or accidental discharges. Ammunition for air weapons has become increasingly sophisticated, effective and therefore increasingly dangerous if misused, though freely available being a mere projectile without a concomitant cartridge containing a propellant and an initiator.

Balancing the competing requirements of air-breathing and display behaviour during male-male interactions in Siamese fighting fish Betta splendens.

PubMed

Alton, Lesley A; Portugal, Steven J; White, Craig R

2013-02-01

Air-breathing fish of the Anabantoidei group meet their metabolic requirements for oxygen through both aerial and aquatic gas exchange. Siamese fighting fish Betta splendens are anabantoids that frequently engage in aggressive male-male interactions which cause significant increases in metabolic rate and oxygen requirements. These interactions involve opercular flaring behaviour that is thought to limit aquatic oxygen uptake, and combines with the increase in metabolic rate to cause an increase in air-breathing behaviour. Air-breathing events interrupt display behaviour and increase risk of predation, raising the question of how Siamese fighting fish manage their oxygen requirements during agonistic encounters. Using open-flow respirometry, we measured rate of oxygen consumption in displaying fish to determine if males increase oxygen uptake per breath to minimise visits to the surface, or increase their reliance on aquatic oxygen uptake. We found that the increased oxygen requirements of Siamese fighting fish during display behaviour were met by increased oxygen uptake from the air with no significant changes in aquatic oxygen uptake. The increased aerial oxygen uptake was achieved almost entirely by an increase in air-breathing frequency. We conclude that limitations imposed by the reduced gill surface area of air-breathing fish restrict the ability of Siamese fighting fish to increase aquatic uptake, and limitations of the air-breathing organ of anabantoids largely restrict their capacity to increase oxygen uptake per breath. The resulting need to increase surfacing frequency during metabolically demanding agonistic encounters has presumably contributed to the evolution of the stereotyped surfacing behaviour seen during male-male interactions, during which one of the fish will lead the other to the surface, and each will take a breath of air. Copyright © 2012. Published by Elsevier Inc.

Automated telescope scheduling

NASA Technical Reports Server (NTRS)

Johnston, Mark D.

1988-01-01

With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

The Naturalistic Flight Deck System: An Integrated System Concept for Improved Single-Pilot Operations

NASA Technical Reports Server (NTRS)

Schutte, Paul C.; Goodrich, Kenneth H.; Cox, David E.; Jackson, Bruce; Palmer, Michael T.; Pope, Alan T.; Schlecht, Robin W.; Tedjojuwono, Ken K.; Trujillo, Anna C.; Williams, Ralph A.;

[Effects of air temperature increase and precipitation change on grain yield and quality of spring wheat in semiarid area of Northwest China].

PubMed

Wang, He-ling; Zhang, Qiang; Wang, Run-yuan; Gan, Yan-tai; Niu, Jun-yi; Zhang, Kai; Zhao, Fu-nian; Zhao, Hong

2015-01-01

In order to predict effects of climate changing on growth, quality and grain yields of spring wheat, a field experiment was conducted to investigate the effects of air temperature increases (0 °C, 1.0 °C, 2.0° C and 3.0°) and precipitation variations (decrease 20%, unchanging and increase 20%) on grain yields, quality, diseases and insect pests of spring wheat at the Dingxi Arid Meteorology and Ecological Environment Experimental Station of the Institute of Arid Meteorology of China Meteorological Administration (35°35' N ,104°37' E). The results showed that effects of precipitation variations on kernel numbers of spring wheat were not significant when temperature increased by less than 2.0° C , but was significant when temperature increased by 3.0° C. Temperature increase enhanced kernel numbers, while temperature decrease reduced kernel numbers. The negative effect of temperature on thousand-kernel mass of spring wheat increased with increasing air temperature. The sterile spikelet of spring wheat response to air temperature was quadratic under all precipitation regimes. Compared with control ( no temperature increase), the decreases of grain yield of spring wheat when air temperature increased by 1.0°C, 2.0°C and 3.0°C under each of the three precipitation conditions (decrease 20%, no changing and increase 20%) were 12.1%, 24.7% and 42.7%, 8.4%, 15.1% and 21.8%, and 9.0%, 15.5% and 22.2%, respectively. The starch content of spring wheat decreased and the protein content increased with increasing air temperature. The number of aphids increased when air temperature increased by 2.0°C , but decreased when air temperature increased by 3.0°CT. The infection rates of rust disease increased with increasing air temperature.

The influence of air-conditioning on street temperatures in the city of Paris

NASA Astrophysics Data System (ADS)

de Munck, C. S.; Pigeon, G.; Masson, V.; Marchadier, C.; Meunier, F.; Tréméac, B.; Merchat, M.

2010-12-01

A consequence of urban heat islands in summer is the increased use of air-conditioning during extreme heat events : the use of air-conditioning systems, while cooling the inside of buildings releases waste heat (as latent and sensible heat) in the lower part of the urban atmosphere, hence potentially increasing air street temperatures where the heat is released. This may lead locally to a further increase in air street temperatures, therefore increasing the air cooling demand, while at the same time lowering the efficiency of air-conditioning units. A coupled model consisting of a meso-scale meteorological model (MESO-NH) and an urban energy balance model (TEB) has been implemented with an air-conditioning module and used in combination to real spatialised datasets to understand and quantify potential increases in temperature due to air-conditioning heat releases for the city of Paris . In a first instance, the current types of air-conditioning systems co-existing in the city were simulated (underground chilled water network, wet cooling towers and individual air-conditioning units) to study the effects of latent and sensible heat releases on street temperatures. In a third instance, 2 scenarios were tested to characterise the impacts of likely future trends in air-conditioning equipment in the city : a first scenario for which current heat releases were converted to sensible heat, and a second based on 2030s projections of air-conditioning equipment at the scale of the city. All the scenarios showed an increase in street temperature which, as expected, was greater at night time than day time. For the first two scenarios, this increase in street temperatures was localised at or near the sources of air-conditioner heat releases, while the 2030s air-conditioning scenario impacted wider zones in the city. The amplitude of the increase in temperature varied from 0,25°C to 1°C for the air-conditioning current state, between 0,25°C and 2°C for the sensible heat release only scenario, and finally from 0,25°C to 2 °C for the 2030s scenario, with impacts of up to 3°C locally. Overall, these results demonstrated to which extend the use air-conditioning could enhance street temperatures in the city of Paris and the importance of a spatialised approach.

The relationship between air layers and evaporative resistance of male Chinese ethnic clothing.

PubMed

Wang, Faming; Peng, Hui; Shi, Wen

2016-09-01

In this study, the air layer distribution and evaporative resistances of 39 sets of male Chinese ethnic clothing were investigated using a sweating thermal manikin and the three-dimensional (3D) body scanning technique. Relationships between the evaporative resistance and air layers (i.e., air gap thickness and air volume) were explored. The results demonstrated that the clothing total evaporative resistance increases with the increasing air gap size/air volume, but the rate of increase gradually decreases as the mean air gap size or the total air volume becomes larger. The clothing total evaporative resistance reaches its maximum when the average air gap size and the total air volume are 41.6 mm and 69.9 dm(3), respectively. Similar general trends were also found between local mean air gap size and clothing local evaporative resistance at different body parts. However, different body parts show varied rates of increase and decrease in the local evaporative resistance. The research findings provide a comprehensive database for predicting overall and local human thermal comfort while wearing male Chinese ethnic clothing. Copyright © 2016 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.

Air pollution is associated with primary health care visits for asthma in Sweden: A case-crossover design with a distributed lag non-linear model.

PubMed

Taj, Tahir; Jakobsson, Kristina; Stroh, Emilie; Oudin, Anna

2016-05-01

Air pollution can increase the symptoms of asthma and has an acute effect on the number of emergency room visits and hospital admissions because of asthma, but little is known about the effect of air pollution on the number of primary health care (PHC) visits for asthma. To investigate the association between air pollution and the number of PHC visits for asthma in Scania, southern Sweden. Data on daily PHC visits for asthma were obtained from a regional healthcare database in Scania, which covers approximately half a million people. Air pollution data from 2005 to 2010 were obtained from six urban background stations. We used a case-crossover study design and a distributed lag non-linear model in the analysis. The air pollution levels were generally within the EU air quality guidelines. The mean number of daily PHC visits for asthma was 34. The number of PHC visits increased by 5% (95% confidence interval (CI): 3.91-6.25%) with every 10µg m(-3) increase in daily mean NO2 lag (0-15), suggesting that daily air pollution levels are associated with PHC visits for asthma. Even though the air quality in Scania between 2005 and 2010 was within EU's guidelines, the number of PHC visits for asthma increased with increasing levels of air pollution. This suggests that as well as increasing hospital and emergency room visits, air pollution increases the burden on PHC due to milder symptoms of asthma. Copyright © 2016 Elsevier Ltd. All rights reserved.

Air flow optimization for energy efficient blower of biosafety cabinet class II A2

NASA Astrophysics Data System (ADS)

Ibrahim, M. D.; Mohtar, M. Z.; Alias, A. A.; Wong, L. K.; Yunos, Y. S.; Rahman, M. R. A.; Zulkharnain, A.; Tan, C. S.; Thayan, R.

2017-04-01

An energy efficient Biosafety Cabinet (BSC) has become a big challenge for manufacturers to develop BSC with the highest level of protection. The objective of research is to increase air flow velocity discharge from centrifugal blower. An aerodynamic duct shape inspired by the shape of Peregrine Falcon’s wing during diving flight is added to the end of the centrifugal blower. Investigation of air movement is determined by computational fluid dynamics (CFD) simulation. The results showed that air velocity can be increased by double compared to typical manufactured BSC and no air recirculation. As conclusion, a novel design of aerodynamic duct shape successfully developed and proved that air velocity can be increase naturally with same impeller speed. It can contribute in increasing energy efficiency of the centrifugal blower. It is vital to BSC manufacturer and can be apply to Heating, Air Ventilation and Air Conditioning (HVAC) industries.

Increase in whole-body peripheral vascular resistance during three hours of air or oxygen prebreathing

NASA Technical Reports Server (NTRS)

Waligora, J. M.; Horrigan, D. J., Jr.; Conkin, J.; Dierlam, J. J.; Stanford, J., Jr.; Riddle, J. R.

1984-01-01

Male and female subjects prebreathed air or 100% oxygen through a mask for 3.0 hours while comfortably reclined. Blood pressures, heart rate, and cardiac output were collected before and after the prebreathe. Peripheral vascular resistance (PVR) was calculated from these parameters and increased by 29% during oxygen prebreathing and 15% during air prebreathing. The oxygen contributed substantially to the increase in PVR. Diastolic blood pressure increased by 18% during the oxygen prebreathe while stystolic blood pressure showed no change under either procedure. The increase in PVR during air prebreathing was attributed to procedural stress common to air and oxygen prebreathing.

Impact of air pollutants from surface transport sources on human health: A modeling and epidemiological approach.

PubMed

Aggarwal, Preeti; Jain, Suresh

2015-10-01

This study adopted an integrated 'source-to-receptor' assessment paradigm in order to determine the effects of emissions from passenger transport on urban air quality and human health in the megacity, Delhi. The emission modeling was carried out for the base year 2007 and three alternate (ALT) policy scenarios along with a business as usual (BAU) scenario for the year 2021. An Activity-Structure-Emission Factor (ASF) framework was adapted for emission modeling, followed by a grid-wise air quality assessment using AERMOD and a health impact assessment using an epidemiological approach. It was observed that a 2021-ALT-III scenario resulted in a maximum concentration reduction of ~24%, ~42% and ~58% for carbon monoxide (CO), nitrogen dioxide (NO2) and particulate matter (PM), respectively, compared to a 2021-BAU scenario. Further, it results in significant reductions in respiratory and cardiovascular mortality, morbidity and Disability Adjusted Life Years (DALY) by 41% and 58% on exposure to PM2.5 and NO2 concentrations when compared to the 2021-BAU scenario, respectively. In other words, a mix of proposed policy interventions namely the full-phased introduction of the Integrated Mass Transit System, fixed bus speed, stringent vehicle emission norms and a hike in parking fees for private vehicles would help in strengthening the capability of passenger transport to cater to a growing transport demand with a minimum health burden in the Delhi region. Further, the study estimated that the transport of goods would be responsible for ~5.5% additional VKT in the 2021-BAU scenario; however, it will contribute ~49% and ~55% additional NO2 and PM2.5 concentrations, respectively, in the Delhi region. Implementation of diesel particulate filters for goods vehicles in the 2021-ALT-IV-O scenario would help in the reduction of ~87% of PM2.5 concentration, compared to the 2021-BAU scenario; translating into a gain of 1267 and 505 DALY per million people from exposure to PM2.5 and NO2 concentrations, respectively. These findings suggest that significant health benefits are possible if goods transport is also included while designing strategies and policies in order to improve the overall urban air quality and minimize health impacts in city areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Health benefits from large-scale ozone reduction in the United States.

PubMed

Berman, Jesse D; Fann, Neal; Hollingsworth, John W; Pinkerton, Kent E; Rom, William N; Szema, Anthony M; Breysse, Patrick N; White, Ronald H; Curriero, Frank C

2012-10-01

Exposure to ozone has been associated with adverse health effects, including premature mortality and cardiopulmonary and respiratory morbidity. In 2008, the U.S. Environmental Protection Agency (EPA) lowered the primary (health-based) National Ambient Air Quality Standard (NAAQS) for ozone to 75 ppb, expressed as the fourth-highest daily maximum 8-hr average over a 24-hr period. Based on recent monitoring data, U.S. ozone levels still exceed this standard in numerous locations, resulting in avoidable adverse health consequences. We sought to quantify the potential human health benefits from achieving the current primary NAAQS standard of 75 ppb and two alternative standard levels, 70 and 60 ppb, which represent the range recommended by the U.S. EPA Clean Air Scientific Advisory Committee (CASAC). We applied health impact assessment methodology to estimate numbers of deaths and other adverse health outcomes that would have been avoided during 2005, 2006, and 2007 if the current (or lower) NAAQS ozone standards had been met. Estimated reductions in ozone concentrations were interpolated according to geographic area and year, and concentration-response functions were obtained or derived from the epidemiological literature. We estimated that annual numbers of avoided ozone-related premature deaths would have ranged from 1,410 to 2,480 at 75 ppb to 2,450 to 4,130 at 70 ppb, and 5,210 to 7,990 at 60 ppb. Acute respiratory symptoms would have been reduced by 3 million cases and school-loss days by 1 million cases annually if the current 75-ppb standard had been attained. Substantially greater health benefits would have resulted if the CASAC-recommended range of standards (70-60 ppb) had been met. Attaining a more stringent primary ozone standard would significantly reduce ozone-related premature mortality and morbidity.

Environmental, health, and safety issues of fuel cells in transportation. Volume 1: Phosphoric acid fuel-cell buses

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

Ring, S

1994-12-01

The U.S. Department of Energy (DOE) chartered the Phosphoric Acid Fuel-Cell (PAFC) Bus Program to demonstrate the feasibility of fuel cells in heavy-duty transportation systems. As part of this program, PAFC- powered buses are being built to meet transit industry design and performance standards. Test-bed bus-1 (TBB-1) was designed in 1993 and integrated in March 1994. TBB-2 and TBB-3 are under construction and should be integrated in early 1995. In 1987 Phase I of the program began with the development and testing of two conceptual system designs- liquid- and air-cooled systems. The liquid-cooled PAFC system was chosen to continue, throughmore » a competitive award, into Phase H, beginning in 1991. Three hybrid buses, which combine fuel-cell and battery technologies, were designed during Phase III. After completing Phase II, DOE plans a comprehensive performance testing program (Phase HI) to verify that the buses meet stringent transit industry requirements. The Phase III study will evaluate the PAFC bus and compare it to a conventional diesel bus. This NREL study assesses the environmental, health, and safety (EH&S) issues that may affect the commercialization of the PAFC bus. Because safety is a critical factor for consumer acceptance of new transportation-based technologies the study focuses on these issues. The study examines health and safety together because they are integrally related. In addition, this report briefly discusses two environmental issues that are of concern to the Environmental Protection Agency (EPA). The first issue involves a surge battery used by the PAFC bus that contains hazardous constituents. The second issue concerns the regulated air emissions produced during operation of the PAFC bus.« less