Science.gov

Sample records for adverse atmospheric conditions

  1. Performance evaluation of laser scanners through the atmosphere with adverse condition

    NASA Astrophysics Data System (ADS)

    Hespel, L.; Riviere, N.; Huet, T.; Tanguy, B.; Ceolato, R.

    2011-11-01

    Using laser imaging systems to represent 3-D scene becomes a referent prospective technology in the areas of guidance and navigation. Measurements with high spatial resolution for significant range can be achieved, even in degraded visibility conditions such as the Brown-White Out, rain, fog, sandstorms... Moreover, this technology is well suited for assisted perception tasks (access to 3D information) and obstacle detection (telemetry of small objects). For airborne applications, it is very complementary to conventional enhanced vision systems such as Forward Looking Infrared (FLIR) and millimeter wave radar to provide images of land in environments with limited visibility. It also offers a 3D mapping of land or a single location in relation to the environment, which means alone or coupled with others, can realign and secure real-time database of information used such in a synthetic vision system (SVS). The objective of the work is to assess the impact of degraded visibility conditions on the laser radiometric propagation of a 3D laser scanner as they directly influence the performance of the ladar system [1].

  2. HEPA Filter Performance under Adverse Conditions

    SciTech Connect

    Parsons, Michael; Hogancamp, Kristina; Alderman, Steven; Waggoner, Charles

    2007-07-01

    This study involved challenging nuclear grade high-efficiency particulate air (HEPA) filters under a variety of conditions that can arise in Department of Energy (DOE) applications such as: low or high RH, controlled and uncontrolled challenge, and filters with physically damaged media or seals (i.e., leaks). Reported findings correlate filter function as measured by traditional differential pressure techniques in comparison with simultaneous instrumental determination of up and down stream PM concentrations. Additionally, emission rates and failure signatures will be discussed for filters that have either failed or exceeded their usable lifetime. Significant findings from this effort include the use of thermocouples up and down stream of the filter housing to detect the presence of moisture. Also demonstrated in the moisture challenge series of tests is the effect of repeated wetting of the filter. This produces a phenomenon referred to as transient failure before the tensile strength of the media weakens to the point of physical failure. An evaluation of the effect of particle size distribution of the challenge aerosol on loading capacity of filters is also included. Results for soot and two size distributions of KCl are reported. Loading capacities for filters ranged from approximately 70 g of soot to nearly 900 g for the larger particle size distribution of KCl. (authors)

  3. Management of Cattle Exposed to Adverse Environmental Conditions.

    PubMed

    Mader, Terry L; Griffin, Dee

    2015-07-01

    During periods of adverse weather, optimum conditions for animal comfort and performance are compromised. Use of alternative supplementation programs need to be considered for livestock challenged by adverse environmental conditions. Use of additional water for consumption and cooling, shade, and/or alternative management strategies need to be considered to help livestock cope with heat stress. For animals reared outside during winter, strategies that increase animal space and environmental buffers need to be used to minimize effects of mud, wet conditions, and windchill. There are ample opportunities for livestock producers to enhance animal welfare and minimize the impact of environmental stress. PMID:26139190

  4. Word Learning under Adverse Listening Conditions: Context-Specific Recognition

    ERIC Educational Resources Information Center

    Creel, Sarah C.; Aslin, Richard N.; Tanenhaus, Michael K.

    2012-01-01

    Previous studies of word learning have presented the items to listeners under ideal conditions. Here we ask how listeners learn new vocabulary items under adverse listening conditions. Would listeners form acoustically-specific representations that incorporated the noise, base their representations on noise-free language knowledge, or both? To…

  5. Quality of whey powders stored under adverse conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whey protein concentrate powder (WPC) is exported by the U.S. and is included in emergency aid foods, but the bags sent overseas are usually stored without refrigeration and under elevated temperature and relative humidity (RH). The shelf life of WPC under adverse conditions must be known to preven...

  6. Uncertainty Comparison of Visual Sensing in Adverse Weather Conditions.

    PubMed

    Lo, Shi-Wei; Wu, Jyh-Horng; Chen, Lun-Chi; Tseng, Chien-Hao; Lin, Fang-Pang; Hsu, Ching-Han

    2016-01-01

    This paper focuses on flood-region detection using monitoring images. However, adverse weather affects the outcome of image segmentation methods. In this paper, we present an experimental comparison of an outdoor visual sensing system using region-growing methods with two different growing rules-namely, GrowCut and RegGro. For each growing rule, several tests on adverse weather and lens-stained scenes were performed, taking into account and analyzing different weather conditions with the outdoor visual sensing system. The influence of several weather conditions was analyzed, highlighting their effect on the outdoor visual sensing system with different growing rules. Furthermore, experimental errors and uncertainties obtained with the growing rules were compared. The segmentation accuracy of flood regions yielded by the GrowCut, RegGro, and hybrid methods was 75%, 85%, and 87.7%, respectively. PMID:27447642

  7. Hierarchically nanotextured surfaces maintaining superhydrophobicity under severely adverse conditions

    NASA Astrophysics Data System (ADS)

    Maitra, Tanmoy; Antonini, Carlo; Auf der Mauer, Matthias; Stamatopoulos, Christos; Tiwari, Manish K.; Poulikakos, Dimos

    2014-07-01

    Superhydrophobic surfaces are highly desirable for a broad range of technologies and products affecting everyday life. Despite significant progress in recent years in understanding the principles of hydrophobicity, mostly inspired by surface designs found in nature, many man-made surfaces employ readily processable materials, ideal to demonstrate principles, but with little chance of survivability outside a very limited range of well-controlled environments. Here we focus on the rational development of robust, hierarchically nanostructured, environmentally friendly, metal-based (aluminum) superhydrophobic surfaces, which maintain their performance under severely adverse conditions. Based on their functionality, we superpose selected hydrophobic layers (i.e. self-assembled monolayers, thin films, or nanofibrous coatings) on hierarchically textured aluminum surfaces, collectively imparting high level robustness of superhydrophobicity under adverse conditions. These surfaces simultaneously exhibit chemical stability, mechanical durability and droplet impalement resistance. They impressively maintained their superhydrophobicity after exposure to severely adverse chemical environments like strong alkaline (pH ~ 9-10), acidic (pH ~ 2-3), and ionic solutions (3.5 weight% of sodium chloride), and could simultaneously resist water droplet impalement up to an impact velocity of 3.2 m s-1 as well as withstand standard mechanical durability tests.Superhydrophobic surfaces are highly desirable for a broad range of technologies and products affecting everyday life. Despite significant progress in recent years in understanding the principles of hydrophobicity, mostly inspired by surface designs found in nature, many man-made surfaces employ readily processable materials, ideal to demonstrate principles, but with little chance of survivability outside a very limited range of well-controlled environments. Here we focus on the rational development of robust, hierarchically

  8. Perceptual Learning of Speech under Optimal and Adverse Conditions

    PubMed Central

    Zhang, Xujin; Samuel, Arthur G.

    2014-01-01

    Humans have a remarkable ability to understand spoken language despite the large amount of variability in speech. Previous research has shown that listeners can use lexical information to guide their interpretation of atypical sounds in speech (Norris, McQueen, & Cutler, 2003). This kind of lexically induced perceptual learning enables people to adjust to the variations in utterances due to talker-specific characteristics, such as individual identity and dialect. The current study investigated perceptual learning in two optimal conditions: conversational speech (Experiment 1) vs. clear speech (Experiment 2), and three adverse conditions: noise (Experiment 3a) vs. two cognitive loads (Experiments 4a & 4b). Perceptual learning occurred in the two optimal conditions and in the two cognitive load conditions, but not in the noise condition. Furthermore, perceptual learning occurred only in the first of two sessions for each participant, and only for atypical /s/ sounds and not for atypical /f/ sounds. This pattern of learning and non-learning reflects a balance between flexibility and stability that the speech system must have to deal with speech variability in the diverse conditions that speech is encountered. PMID:23815478

  9. Algorithms for contours depicting static electric fields during adverse weather conditions

    NASA Technical Reports Server (NTRS)

    Rompala, John T.

    1991-01-01

    A flexible and functional analytical tool is developed for the study of electric fields during adverse weather conditions. This tool is designed for use by members of the Atmospheric Science Group as part of their overall effort to appraise environmental conditions during these situations. It is also used to illustrate approaches open to those interested in the study of the physics of ambient electric field phenomena. Computer resources of KSC are coordinated with original software to produce contour interpretations of electric field data available from a grid of field mills spanning the region. Three model algorithms are presented and examples are given illustrating the system design, flexibility, and utility.

  10. Speech perception with tactile support in adverse listening conditions

    NASA Astrophysics Data System (ADS)

    Drullman, Rob; Bronkhorst, Adelbert W.

    2002-05-01

    Since long, different methods of vibrotactile stimulation have been used as an aid for speech perception by some people with severe hearing impairment. The fact that experiments have shown (limited) benefits proves that tactile information can indeed give some support. In our research program on multimodal interfaces, we wondered if normal hearing listeners could benefit from tactile information when speech was presented in adverse listening conditions. Therefore, we set up a pilot experiment with a male speaker against a background of one, two, four or eight competing male speakers or speech noise. Sound was presented diotically to the subjects and the speech-reception threshold (SRT) for short sentences was measured. The temporal envelope (0-30 Hz) of the speech signal was computed in real time and led to the tactile transducer (MiniVib), which was fixed to the index finger. First results show a significant drop in SRT of about 3 dB when using tactile stimulation in the condition of one competing speaker. In the other conditions no significant effects were found, but there is a trend of a decrease of the SRT when tactile information is given. We will discuss the results of further experiments.

  11. Risk of Adverse Cognitive or Behavioral Conditions and Psychiatric Disorders

    NASA Technical Reports Server (NTRS)

    Slack, Kelley J.; Schneiderman, Jason S.; Leveton, Lauren B.; Whitmire, Alexandra M.; Picano, James J.

    2015-01-01

    The NASA commitment to human space flight includes continuing to fly astronauts on the ISS until it is decommissioned as well as possibly returning astronauts to the moon or having astronauts venture to an asteroid or Mars. As missions leave low Earth orbit and explore deeper space, BHP supports and conducts research to enable a risk posture that considers the risk of adverse cognitive or behavioral conditions and psychiatric disorders “acceptable given mitigations,” for pre-, in, and post-flight.The Human System Risk Board (HSRB) determines the risk of various mission scenarios using a likelihood (per person per year) by consequences matrix examining those risks across two categories—long term health and operational (within mission). Colors from a stoplight signal are used by HSRB and quickly provide a means of assessing overall perceived risk for a particular mission scenario. Risk associated with the current six month missions on the ISS are classified as “accepted with monitoring” while planetary missions, such as a mission to Mars, are recognized to be a “red” risk that requires mitigation to ensure mission success.Currently, the HSRB deems that the risk of adverse cognitive or behavioral conditions and psychiatric outcomes requires mitigation for planetary missions owing to long duration isolation and radiation exposure (see Table 1). While limited research evidence exists from spaceflight, it is well known anecdotally that the shift from the two week shuttle missions to the six month ISS missions renders the psychological stressors of space as more salient over longer duration missions. Shuttle astronauts were expected just to tolerate any stressors that arose during their mission and were successful at doing so (Whitmire et al, 2013). While it is possible to deal with stressors such as social isolation and to live with incompatible crewmembers for two weeks on shuttle, “ignoring it” is much less likely to be a successful coping mechanism

  12. Transport Across Chloroplast Membranes: Optimizing Photosynthesis for Adverse Environmental Conditions.

    PubMed

    Pottosin, Igor; Shabala, Sergey

    2016-03-01

    Chloroplasts are central to solar light harvesting and photosynthesis. Optimal chloroplast functioning is vitally dependent on a very intensive traffic of metabolites and ions between the cytosol and stroma, and should be attuned for adverse environmental conditions. This is achieved by an orchestrated regulation of a variety of transport systems located at chloroplast membranes such as porines, solute channels, ion-specific cation and anion channels, and various primary and secondary active transport systems. In this review we describe the molecular nature and functional properties of the inner and outer envelope and thylakoid membrane channels and transporters. We then discuss how their orchestrated regulation affects thylakoid structure, electron transport and excitation energy transfer, proton-motive force partition, ion homeostasis, stromal pH regulation, and volume regulation. We link the activity of key cation and anion transport systems with stress-specific signaling processes in chloroplasts, and discuss how these signals interact with the signals generated in other organelles to optimize the cell performance, with a special emphasis on Ca(2+) and reactive oxygen species signaling. PMID:26597501

  13. Effect of Atmospheric Conditions on LIBS Spectra

    PubMed Central

    Effenberger, Andrew J.; Scott, Jill R.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air. PMID:22399914

  14. Effect of atmospheric conditions on LIBS spectra.

    PubMed

    Effenberger, Andrew J; Scott, Jill R

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air. PMID:22399914

  15. Effect of Atmospheric Conditions on LIBS Spectra

    SciTech Connect

    Andrew J. Effenberger; Jill R. Scott

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air.

  16. 75 FR 8353 - Waiver of Filing Deadline Due to Adverse Weather Conditions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... COMMISSION Waiver of Filing Deadline Due to Adverse Weather Conditions February 16, 2010. AGENCY: Federal Communications Commission. ACTION: Notice. SUMMARY: Due to adverse weather conditions, the Federal Communications..., February 11, 2010. In recognition of the numerous closings and disruptions caused by the weather in...

  17. Research on long-range laser active imaging system applied in adverse weather conditions

    NASA Astrophysics Data System (ADS)

    Gai, Zhi-gang; Liu, Meng-de; Yang, Li; Kabanov, V. V.; Shi, Lei; Zhao, Jie; Chu, Shi-bo; Yang, Jun-xian; Zhou, Yang

    2013-09-01

    A low-light level night vision device or thermal infrared imager belonging to passive imaging system is generally used in daily target detection and identification. But in adverse weather conditions of dark of night, poor atmospheric transmission characteristics or strong backscattering (fog, dust, rain, snow, etc.), even the most sensitive low-light level night vision could not provide enough image resolution for detecting and identifying targets, and the thermal infrared imager is also limited by low temperature contrast. A long-range laser active imaging system, in combination with high-power semiconductor pulsed lasers with collimation technology, receiving objective lens of large diameter, long focal length and narrow viewing angle, high-gain image intensifier CCD (ICCD) camera and range-gated synchronization control technology, is developed for long distance target detection and high resolution imaging in adverse weather conditions. The system composition and operating principle are introduced. The extremely powerful and efficient illuminators with collimation technology are able to deliver uniform beams, which are essential for illuminating targets at a distance and generating high-quality images. The particular receiving objective lens, ICCD camera and range-gated synchronization control technology could reduce strong backscattering signal and improve imaging signal-to-noise ratio. The laboratory and outfield experiments have been done to validate imaging effect and imaging quality. The results show that the minimum resolution is about 3-5cm, 10cm, and greater than 20 cm for target far from 1100m, 4700m, and 6700m respectively in dark of night. Furthermore, the minimum resolution could reach to 10cm and 20cm for target far from 2500m and 4800m respectively and the image is too blurred to accurately identify the target when observing the target far from 7200m in rainy condition.

  18. 7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Eligible losses, adverse weather, and other loss... for Livestock, Honeybees, and Farm-Raised Fish Program § 760.203 Eligible losses, adverse weather, and... weather or eligible loss condition, as determined by the Deputy Administrator, (including, but not...

  19. 7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 7 2013-01-01 2013-01-01 false Eligible losses, adverse weather, and other loss... for Livestock, Honeybees, and Farm-Raised Fish Program § 760.203 Eligible losses, adverse weather, and... weather or eligible loss condition, as determined by the Deputy Administrator, (including, but not...

  20. 7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Eligible losses, adverse weather, and other loss... for Livestock, Honeybees, and Farm-Raised Fish Program § 760.203 Eligible losses, adverse weather, and... weather or eligible loss condition, as determined by the Deputy Administrator, (including, but not...

  1. 7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Eligible losses, adverse weather, and other loss... for Livestock, Honeybees, and Farm-Raised Fish Program § 760.203 Eligible losses, adverse weather, and... weather or eligible loss condition, as determined by the Deputy Administrator, (including, but not...

  2. Fluorescence parameters of leaves of trees and shrubs during period of adverse weather conditions in Krasnoyarsk

    NASA Astrophysics Data System (ADS)

    Zavorueva, E. N.; Zavoruev, V. V.

    2015-11-01

    The effect of adverse weather conditions (AWC) on the fluorescence parameters of leaves Prinsepia sinensis, Amelanchier florida, Crataegus chlorocarca is obtained. However, significant changes in the fluorescence of the leaves of Acer negundo, Betula pendula under AWC were not observed.

  3. ACCEPT: Introduction of the Adverse Condition and Critical Event Prediction Toolbox

    NASA Technical Reports Server (NTRS)

    Martin, Rodney A.; Santanu, Das; Janakiraman, Vijay Manikandan; Hosein, Stefan

    2015-01-01

    The prediction of anomalies or adverse events is a challenging task, and there are a variety of methods which can be used to address the problem. In this paper, we introduce a generic framework developed in MATLAB (sup registered mark) called ACCEPT (Adverse Condition and Critical Event Prediction Toolbox). ACCEPT is an architectural framework designed to compare and contrast the performance of a variety of machine learning and early warning algorithms, and tests the capability of these algorithms to robustly predict the onset of adverse events in any time-series data generating systems or processes.

  4. Health Monitoring and Management for Manufacturing Workers in Adverse Working Conditions.

    PubMed

    Xu, Xiaoya; Zhong, Miao; Wan, Jiafu; Yi, Minglun; Gao, Tiancheng

    2016-10-01

    In adverse working conditions, environmental parameters such as metallic dust, noise, and environmental temperature, directly affect the health condition of manufacturing workers. It is therefore important to implement health monitoring and management based on important physiological parameters (e.g., heart rate, blood pressure, and body temperature). In recent years, new technologies, such as body area networks, cloud computing, and smart clothing, have allowed the improvement of the quality of services. In this article, we first give five-layer architecture for health monitoring and management of manufacturing workers. Then, we analyze the system implementation process, including environmental data processing, physical condition monitoring and system services and management, and present the corresponding algorithms. Finally, we carry out an evaluation and analysis from the perspective of insurance and compensation for manufacturing workers in adverse working conditions. The proposed scheme will contribute to the improvement of workplace conditions, realize health monitoring and management, and protect the interests of manufacturing workers. PMID:27624491

  5. Comprehension of Familiar and Unfamiliar Native Accents under Adverse Listening Conditions

    ERIC Educational Resources Information Center

    Adank, Patti; Evans, Bronwen G.; Stuart-Smith, Jane; Scott, Sophie K.

    2009-01-01

    This study aimed to determine the relative processing cost associated with comprehension of an unfamiliar native accent under adverse listening conditions. Two sentence verification experiments were conducted in which listeners heard sentences at various signal-to-noise ratios. In Experiment 1, these sentences were spoken in a familiar or an…

  6. Adverse Pregnancy Conditions, Infertility, and Future Cardiovascular Risk: Implications for Mother and Child

    PubMed Central

    Park, Ki; Wei, Janet; Minissian, Margo; Merz, C. Noel Bairey

    2016-01-01

    Adverse pregnancy conditions in women are common and have been associated with adverse cardiovascular and metabolic outcomes such as myocardial infarction and stroke. As risk stratification in women is often suboptimal, recognition of non-traditional risk factors such as hypertensive disorders of pregnancy and premature delivery has become increasingly important. Additionally, such conditions may also increase the risk of cardiovascular disease in the children of afflicted women. In this review, we aim to highlight these conditions, along with infertility, and the association between such conditions and various cardiovascular outcomes and related maternal risk along with potential translation of risk to offspring. We will also discuss proposed mechanisms driving these associations as well as potential opportunities for screening and risk modification. PMID:26037616

  7. Causal Factors and Adverse Conditions of Aviation Accidents and Incidents Related to Integrated Resilient Aircraft Control

    NASA Technical Reports Server (NTRS)

    Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Sandifer, Carl E.; Jones, Sharon Monica

    2010-01-01

    The causal factors of accidents from the National Transportation Safety Board (NTSB) database and incidents from the Federal Aviation Administration (FAA) database associated with loss of control (LOC) were examined for four types of operations (i.e., Federal Aviation Regulation Part 121, Part 135 Scheduled, Part 135 Nonscheduled, and Part 91) for the years 1988 to 2004. In-flight LOC is a serious aviation problem. Well over half of the LOC accidents included at least one fatality (80 percent in Part 121), and roughly half of all aviation fatalities in the studied time period occurred in conjunction with LOC. An adverse events table was updated to provide focus to the technology validation strategy of the Integrated Resilient Aircraft Control (IRAC) Project. The table contains three types of adverse conditions: failure, damage, and upset. Thirteen different adverse condition subtypes were gleaned from the Aviation Safety Reporting System (ASRS), the FAA Accident and Incident database, and the NTSB database. The severity and frequency of the damage conditions, initial test conditions, and milestones references are also provided.

  8. Assessment of the State of the Art of Flight Control Technologies as Applicable to Adverse Conditions

    NASA Technical Reports Server (NTRS)

    Reveley, Mary s.; Briggs, Jeffrey L.; Leone, Karen M.; Kurtoglu, Tolga; Withrow, Colleen A.

    2010-01-01

    Literature from academia, industry, and other Government agencies was surveyed to assess the state of the art in current Integrated Resilient Aircraft Control (IRAC) aircraft technologies. Over 100 papers from 25 conferences from the time period 2004 to 2009 were reviewed. An assessment of the general state of the art in adaptive flight control is summarized first, followed by an assessment of the state of the art as applicable to 13 identified adverse conditions. Specific areas addressed in the general assessment include flight control when compensating for damage or reduced performance, retrofit software upgrades to flight controllers, flight control through engine response, and finally test and validation of new adaptive controllers. The state-of-the-art assessment applicable to the adverse conditions include technologies not specifically related to flight control, but may serve as inputs to a future flight control algorithm. This study illustrates existing gaps and opportunities for additional research by the NASA IRAC Project

  9. Evaluation of adaptive dynamic range optimization in adverse listening conditions for cochlear implants

    PubMed Central

    Ali, Hussnain; Hazrati, Oldooz; Tobey, Emily A.; Hansen, John H. L

    2014-01-01

    The aim of this study is to investigate the effect of Adaptive Dynamic Range Optimization (ADRO) on speech identification for cochlear implant (CI) users in adverse listening conditions. In this study, anechoic quiet, noisy, reverberant, noisy reverberant, and reverberant noisy conditions are evaluated. Two scenarios are considered when modeling the combined effects of reverberation and noise: (a) noise is added to the reverberant speech, and (b) noisy speech is reverberated. CI users were tested in different listening environments using IEEE sentences presented at 65 dB sound pressure level. No significant effect of ADRO processing on speech intelligibility was observed. PMID:25190428

  10. Evaluation of adaptive dynamic range optimization in adverse listening conditions for cochlear implants.

    PubMed

    Ali, Hussnain; Hazrati, Oldooz; Tobey, Emily A; Hansen, John H L

    2014-09-01

    The aim of this study is to investigate the effect of Adaptive Dynamic Range Optimization (ADRO) on speech identification for cochlear implant (CI) users in adverse listening conditions. In this study, anechoic quiet, noisy, reverberant, noisy reverberant, and reverberant noisy conditions are evaluated. Two scenarios are considered when modeling the combined effects of reverberation and noise: (a) noise is added to the reverberant speech, and (b) noisy speech is reverberated. CI users were tested in different listening environments using IEEE sentences presented at 65 dB sound pressure level. No significant effect of ADRO processing on speech intelligibility was observed. PMID:25190428

  11. Some effects of adverse weather conditions on performance of airplane antiskid braking systems

    NASA Technical Reports Server (NTRS)

    Horne, W. B.; Mccarty, J. L.; Tanner, J. A.

    1976-01-01

    The performance of current antiskid braking systems operating under adverse weather conditions was analyzed in an effort to both identify the causes of locked-wheel skids which sometimes occur when the runway is slippery and to find possible solutions to this operational problem. This analysis was made possible by the quantitative test data provided by recently completed landing research programs using fully instrumented flight test airplanes and was further supported by tests performed at the Langley aircraft landing loads and traction facility. The antiskid system logic for brake control and for both touchdown and locked-wheel protection is described and its response behavior in adverse weather is discussed in detail with the aid of available data. The analysis indicates that the operational performance of the antiskid logic circuits is highly dependent upon wheel spin-up acceleration and can be adversely affected by certain pilot braking inputs when accelerations are low. Normal antiskid performance is assured if the tire-to-runway traction is sufficient to provide high wheel spin-up accelerations or if the system is provided a continuous, accurate ground speed reference. The design of antiskid systems is complicated by the necessity for tradeoffs between tire braking and cornering capabilities, both of which are necessary to provide safe operations in the presence of cross winds, particularly under slippery runway conditions.

  12. Risk of Adverse Cognitive or Behavioral Conditions and Psychiatric Disorders: Evidence Report

    NASA Technical Reports Server (NTRS)

    Slack, Kelley J.; Williams, Thomas J.; Schneiderman, Jason S.; Whitmire, Alexandra M.; Picano, James J.; Leveton, Lauren B.; Schmidt, Lacey L.; Shea, Camille

    2016-01-01

    In April 2010, President Obama declared a space pioneering goal for the United States in general and NASA in particular. "Fifty years after the creation of NASA, our goal is no longer just a destination to reach. Our goal is the capacity for people to work and learn and operate and live safely beyond the Earth for extended periods of time, ultimately in ways that are more sustainable and even indefinite." Thus NASA's Strategic Objective 1.1 emerged as "expand human presence into the solar system and to the surface of Mars to advance exploration, science, innovation, benefits to humanity, and international collaboration" (NASA 2015b). Any space flight, be it of long or short duration, occurs in an extreme environment that has unique stressors. Even with excellent selection methods, the potential for behavioral problems among space flight crews remain a threat to mission success. Assessment of factors that are related to behavioral health can help minimize the chances of distress and, thus, reduce the likelihood of adverse cognitive or behavioral conditions and psychiatric disorders arising within a crew. Similarly, countermeasures that focus on prevention and treatment can mitigate the cognitive or behavioral conditions that, should they arise, would impact mission success. Given the general consensus that longer duration, isolation, and confined missions have a greater risk for behavioral health ensuring crew behavioral health over the long term is essential. Risk, which within the context of this report is assessed with respect to behavioral health and performance, is addressed to deter development of cognitive and behavioral degradations or psychiatric conditions in space flight and analog populations, and to monitor, detect, and treat early risk factors, predictors and other contributing factors. Based on space flight and analog evidence, the average incidence rate of an adverse behavioral health event occurring during a space mission is relatively low for the

  13. Adverse psychosocial working conditions and minor psychiatric disorders among bank workers

    PubMed Central

    2010-01-01

    Background In most countries, the financial service sector has undergone great organizational changes in the past decades, with potential negative impact on bank workers' mental health. The aim of this paper is to estimate the prevalence of minor psychiatric disorders (MPD) among Brazilian bank workers and to investigate whether they are associated with an adverse psychosocial working environment. Methods A cross-sectional study of a random sample of 2,500 workers in a Brazilian state bank in 2008. The presence of MPD was determined by the General Health Questionnaire.(GHQ). Psychosocial work conditions were assessed by means of the Effort-Reward Imbalance (ERI) and Job Content Questionnaire (JCQ). The presence and magnitude of the independent associations between MPD and adverse psychosocial working conditions were determined by Prevalence Ratios, obtained by Poisson regression. Results From 2,337 eligible workers, 88% participated. The prevalence of MPD was greater among women (45% vs. 41%; p > 0.05). In the multivariate analysis, the prevalence of MPD was twice as high among bank workers exposed to high psychological demand and low control at work and under high effort and low reward working conditions. The lack of social support at work and the presence of over-commitment were also associated with higher prevalence of MPD. A negative interaction effect was found between over-commitment and effort-reward imbalance. Conclusion The prevalence of MPD is high among bank workers. The results reinforce the association between MPD and adverse psychosocial working conditions, assessed by the JCQ and ERI models. The direction of the interaction observed between over-commitment and ERI was contrary to what was expected. PMID:21062496

  14. Climate Change and Crop Exposure to Adverse Weather: Changes to Frost Risk and Grapevine Flowering Conditions

    PubMed Central

    Mosedale, Jonathan R.; Wilson, Robert J.; Maclean, Ilya M. D.

    2015-01-01

    The cultivation of grapevines in the UK and many other cool climate regions is expected to benefit from the higher growing season temperatures predicted under future climate scenarios. Yet the effects of climate change on the risk of adverse weather conditions or events at key stages of crop development are not always captured by aggregated measures of seasonal or yearly climates, or by downscaling techniques that assume climate variability will remain unchanged under future scenarios. Using fine resolution projections of future climate scenarios for south-west England and grapevine phenology models we explore how risks to cool-climate vineyard harvests vary under future climate conditions. Results indicate that the risk of adverse conditions during flowering declines under all future climate scenarios. In contrast, the risk of late spring frosts increases under many future climate projections due to advancement in the timing of budbreak. Estimates of frost risk, however, were highly sensitive to the choice of phenology model, and future frost exposure declined when budbreak was calculated using models that included a winter chill requirement for dormancy break. The lack of robust phenological models is a major source of uncertainty concerning the impacts of future climate change on the development of cool-climate viticulture in historically marginal climatic regions. PMID:26496127

  15. LEARNING TO BE BAD: ADVERSE SOCIAL CONDITIONS, SOCIAL SCHEMAS, AND CRIME

    PubMed Central

    Simons, Ronald L.; Burt, Callie Harbin

    2011-01-01

    In this paper we develop and test a new approach to explain the link between social factors and individual offending. We argue that seemingly disparate family, peer, and community conditions lead to crime because the lessons communicated by these events are similar and promote social schemas involving a hostile view of people and relationships, a preference for immediate rewards, and a cynical view of conventional norms. Further, we posit that these three schemas are interconnected and combine to form a criminogenic knowledge structure that gives rise to situational interpretations legitimating criminal behavior. Structural equation modeling with a sample of roughly 700 hundred African American teens provided strong support for the model. The findings indicated that persistent exposure to adverse conditions such as community crime, discrimination, harsh parenting, deviant peers and low neighborhood collective efficacy increased commitment to the three social schemas. The three schemas were highly intercorrelated and combined to form a latent construct that strongly predicted increases in crime. Further, in large measure the effect of the various adverse conditions on increases in crime was indirect through their impact on this latent construct. We discuss the extent to which the social schematic model presented in the paper might be used to integrate concepts and findings from several of the major theories of criminal behavior. PMID:21760641

  16. Space shuttle orbit maneuvering engine reusable thrust chamber: Adverse operating conditions test report

    NASA Technical Reports Server (NTRS)

    Tobin, R. D.

    1974-01-01

    Test hardware, facilities, and procedures are described along with results of electrically heated tube and channel tests conducted to determine adverse operating condition limits for convectively cooled chambers typical of Space Shuttle Orbit Manuevering Engine designs. Hot-start tests were conducted with corrosion resistant steel and nickel tubes with both monomethylhydrazine and 50-50 coolants. Helium ingestion, in both bubble and froth form, was studied in tubular test sections. Helium bubble ingestion and burn-out limits in rectangular channels were also investigated.

  17. Speech perception under adverse conditions: insights from behavioral, computational, and neuroscience research

    PubMed Central

    Guediche, Sara; Blumstein, Sheila E.; Fiez, Julie A.; Holt, Lori L.

    2014-01-01

    Adult speech perception reflects the long-term regularities of the native language, but it is also flexible such that it accommodates and adapts to adverse listening conditions and short-term deviations from native-language norms. The purpose of this article is to examine how the broader neuroscience literature can inform and advance research efforts in understanding the neural basis of flexibility and adaptive plasticity in speech perception. Specifically, we highlight the potential role of learning algorithms that rely on prediction error signals and discuss specific neural structures that are likely to contribute to such learning. To this end, we review behavioral studies, computational accounts, and neuroimaging findings related to adaptive plasticity in speech perception. Already, a few studies have alluded to a potential role of these mechanisms in adaptive plasticity in speech perception. Furthermore, we consider research topics in neuroscience that offer insight into how perception can be adaptively tuned to short-term deviations while balancing the need to maintain stability in the perception of learned long-term regularities. Consideration of the application and limitations of these algorithms in characterizing flexible speech perception under adverse conditions promises to inform theoretical models of speech. PMID:24427119

  18. Bill E. Kunkle Interdisciplinary Beef Symposium: Animal welfare concerns for cattle exposed to adverse environmental conditions.

    PubMed

    Mader, T L

    2014-12-01

    Increasing awareness of animal welfare has become a priority in food production systems involving animals. Under normal working environments, production practices are constantly evaluated to maintain optimum levels of animal well-being. However, during periods of adverse weather, optimum conditions for animal comfort, as well as animal performance, are often compromised. In the Midwest and Great Plains states, the heat waves of 1995, 1999, 2006, 2009, 2010, and 2013 were particularly difficult on animals reared in confinement, with documented cattle losses approaching 5,000 head each year. Additionally, during the summer of 2011, nearly 15,000 head of cattle across 5 states were lost as a result of heat stress. During prolonged periods of heat stress, lower conceptions rates are observed in livestock. In addition, animals reared in confinement buildings are often compromised because of limitations in ventilation systems. Under the opposite environmental spectrum, the winters of 1992 to 1993, 1996 to 1997, 1997 to 1998, 2006 to 2007, and 2008 to 2009 caused hardship for livestock producers, particularly for those rearing animals in an outdoor environment. During the winters of 1996 to 1997 and 2008 to 2009 up to 50% of the newborn calves were lost in many areas, with over 75,000 head of cattle lost in the northern plains states. Late fall and early winter snowstorms in 1992, 1997, 2006, and 2013 resulted in the loss of over 25,000 head of cattle each year in the Great Plains region of the United States. Economic losses from reduced performance of cattle experiencing severe environmental stress likely exceed losses associated with livestock death by 5- to 10-fold. Use of alternative supplementation programs may need to be considered for livestock challenged by adverse environmental conditions. Use of additional water for consumption and cooling, shade, and/or alternative management strategies need to be considered to help livestock cope with heat stress. For animals

  19. A Ground-Based Array to Observe Geospace Electrodynamics During Adverse Space Weather Conditions

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.; Eccles, J. V.; Rice, D.

    2004-05-01

    Geomagnetic Storms occur with surprising frequency and create adverse space weather conditions. During these periods, our knowledge and ability to specify or forecast in adequate detail for user needs is negligible. Neither experimental observations nor theoretical developments have made a significant new impact on the problem for over two decades. Although we can now map Total Electron Content (TEC) in the ionosphere over a continent with sufficient resolution to see coherent long-lived structures, these do not provide constraints on the geospace electrodynamics that is at the heart of our lack of understanding. We present arguments for the need of a continental deployment of ground-based sensors to stepwise advance our understanding of the geospace electrodynamics when it is most adverse from a space weather perspective and also most frustrating from an understanding of Magnetosphere-Ionosphere coupling. That a continental-scale deployment is more productive at addressing the problem than a realizable global distribution is shown. Each measurement is discussed from the point-of-view of either providing new knowledge or becoming a key for future real-time specification and forecasting for user applications. An example of a storm database from one mid-latitude station for the 31 March 2002 is used as a conceptual point in a ground-based array. The presentation focuses on scientific questions that have eluded a quantitative solution for over three decades and view a ground-based array as an "IGY" type of catalyst for answering these questions.

  20. Determination and representation of electric charge distributions associated with adverse weather conditions

    NASA Technical Reports Server (NTRS)

    Rompala, John T.

    1992-01-01

    Algorithms are presented for determining the size and location of electric charges which model storm systems and lightning strikes. The analysis utilizes readings from a grid of ground level field mills and geometric constraints on parameters to arrive at a representative set of charges. This set is used to generate three dimensional graphical depictions of the set as well as contour maps of the ground level electrical environment over the grid. The composite, analytic and graphic package is demonstrated and evaluated using controlled input data and archived data from a storm system. The results demonstrate the packages utility as: an operational tool in appraising adverse weather conditions; a research tool in studies of topics such as storm structure, storm dynamics, and lightning; and a tool in designing and evaluating grid systems.

  1. Functions of Nitric Oxide (NO) in Roots during Development and under Adverse Stress Conditions

    PubMed Central

    Corpas, Francisco J.; Barroso, Juan B.

    2015-01-01

    The free radical molecule, nitric oxide (NO), is present in the principal organs of plants, where it plays an important role in a wide range of physiological functions. Root growth and development are highly regulated by both internal and external factors such as nutrient availability, hormones, pattern formation, cell polarity and cell cycle control. The presence of NO in roots has opened up new areas of research on the role of NO, including root architecture, nutrient acquisition, microorganism interactions and the response mechanisms to adverse environmental conditions, among others. Additionally, the exogenous application of NO throughout the roots has the potential to counteract specific damages caused by certain stresses. This review aims to provide an up-to-date perspective on NO functions in the roots of higher plants. PMID:27135326

  2. Chosen risk level during car-following in adverse weather conditions.

    PubMed

    Hjelkrem, Odd André; Ryeng, Eirin Olaussen

    2016-10-01

    This study examines how precipitation, light conditions and surface conditions affect the drivers' risk perception. An indicator CRI (Chosen Risk Index) is defined, which describes the chosen risk level for drivers in a car-following situation. The dataset contains about 70 000 observations of driver behaviour and weather status on a rural road. Based on the theory of risk homeostasis and an assumption that driving behaviour in situations with daylight, dry road and no precipitation reflects drivers' target level of risk, generalised linear models (GLM) were estimated for cars and trucks separately to reveal the effect of adverse weather conditions on risk perception. The analyses show that both car and truck drivers perceive the highest risk when driving on snow covered roads. For car drivers, a snow covered road in combination with moderate rain or light snow are the factors which lowers the CRI the most. For trucks, snow cover and partially covered roads significantly lowers the CRI, while precipitation did not seem to impose any higher risk. Interaction effects were found for car drivers only. PMID:27454867

  3. Effect of exposure to adverse climatic conditions on production in Manchega dairy sheep.

    PubMed

    Ramón, M; Díaz, C; Pérez-Guzman, M D; Carabaño, M J

    2016-07-01

    The present study aimed to examine the effects of exposure to adverse weather conditions on milk production to assess the thermotolerance capability of the Manchega breed, a dairy sheep reared in the Mediterranean area, and the extent of decline in production outside the thermal comfort zone. To achieve this purpose, we merged data from the official milk recording of the breed with weather information and used to describe the cold and heat stress response for production traits. Production data consisted of 1,094,804 test-day records from the first 3 lactations of 177,605 ewes gathered between years 2000 to 2010. For each production trait and climate variable, the thermal load production response was characterized by the estimation of cold and heat stress thresholds that define a thermoneutral zone and the slopes of production decay outside this thermoneutral zone. Overall, we observed a comfort region between 10 and 22°C for daily average temperature, 18 and 30°C for daily maximum temperature, and from 9 to 18 units for a temperature-humidity index (THI) for all traits. Decline in production due to cold stress effects was of a greater magnitude than heat stress effects, especially for milk yield. Production losses ranged between 7 and 16 and from 0.2 to 0.6g/d per °C (or THI unit) for milk and for fat and protein yields, respectively. For heat stress, the observed decline in production was of 1 to 5 and 0.1 to 0.3g/d per °C (or THI unit) above the threshold for milk yield and for fat and protein yields, respectively. Highly productive animals showed a narrower comfort zone and higher slopes of decay. The study of lagged effects of thermal load showed how consequences of cold and heat stress are already visible in the first hours after exposure. Thus, production losses were due mainly to climate conditions on the day of control and the day before, with conditions on the previous days having a smaller effect. Annual economic losses due to thermal (cold and heat

  4. Overcoming adverse weather conditions with a common optical path, multiple sensors, and intelligent image fusion system

    NASA Astrophysics Data System (ADS)

    Ng, Joseph; Piacentino, Michael; Caldwell, Brian

    2008-04-01

    Mission success is highly dependent on the ability to accomplish Surveillance, Situation Awareness, Target Detection and Classification, but is challenging under adverse weather conditions. This paper introduces an engineering prototype to address the image collection challenges using a Common Optical Path, Multiple Sensors and an Intelligent Image Fusion System, and provides illustrations and sample fusion images. Panavision's advanced wide spectrum optical design has permitted a suite of imagers to perform observations through a common optical path with a common field of view, thereby aligning images and facilitating optimized downstream image processing. The adaptable design also supports continuous zoom or Galilean lenses for multiple field of views. The Multiple Sensors include: (1) High-definition imaging sensors that are small, have low power consumption and a wide dynamic range; (2) EMCCD sensors that transition from daylight to starlight, even under poor weather conditions, with sensitivity down to 0.00025 Lux; and (3) SWIR sensors that, with the advancement in InGaAs, are able to generate ultra-high sensitivity images from 1-1.7μm reflective light and can achieve imaging through haze and some types of camouflage. The intelligent fusion of multiple sensors provides high-resolution color information with previously impossible sensitivity and contrast. With the integration of Field-Programmable Gate Arrays (FPGAs) and Application-Specific Integrated Circuits (ASICs), real-time Image Processing and Fusion Algorithms can facilitate mission success in a small, low power package.

  5. Colorimetric analysis of outdoor illumination across varieties of atmospheric conditions.

    PubMed

    Peyvandi, Shahram; Hernández-Andrés, Javier; Olmo, F J; Nieves, Juan Luis; Romero, Javier

    2016-06-01

    Solar illumination at ground level is subject to a good deal of change in spectral and colorimetric properties. With an aim of understanding the influence of atmospheric components and phases of daylight on colorimetric specifications of downward radiation, more than 5,600,000 spectral irradiance functions of daylight, sunlight, and skylight were simulated by the radiative transfer code, SBDART [Bull. Am. Meteorol. Soc.79, 2101 (1998)], under the atmospheric conditions of clear sky without aerosol particles, clear sky with aerosol particles, and overcast sky. The interquartile range of the correlated color temperatures (CCT) for daylight indicated values from 5712 to 7757 K among the three atmospheric conditions. A minimum CCT of ∼3600  K was found for daylight when aerosol particles are present in the atmosphere. Our analysis indicated that hemispheric daylight with CCT less than 3600 K may be observed in rare conditions in which the level of aerosol is high in the atmosphere. In an atmosphere with aerosol particles, we also found that the chromaticity of daylight may shift along the green-purple direction of the Planckian locus, with a magnitude depending on the spectral extinction by aerosol particles and the amount of water vapor in the atmosphere. The data analysis showed that an extremely high value of CCT, in an atmosphere without aerosol particles, for daylight and skylight at low sun, is mainly due to the effect of Chappuis absorption band of ozone at ∼600  nm. In this paper, we compare our data with well-known observations from previous research, including the ones used by the CIE to define natural daylight illuminants. PMID:27409431

  6. A radar sea clutter model for atmospheric ducting conditions

    NASA Astrophysics Data System (ADS)

    Snyder, F. P.

    1984-07-01

    The Integrated Refractive Effects Prediction System (IREPS) should consider sea clutter effects under atmospheric ducting conditions. The IREPS, undergoing research and development at Naval Ocean Systems Center (NOSC), is intended to provide a shipboard environmental data processing and display capability to assess refractive effects of the lower atmosphere for naval EM systems. Although intended to be incorporated eventually as a part of the Tactical Environment Support System (TESS), the IREPS is currently configured as an interim version based on a Hewlett-Packard 9845 desktop calculator. A comprehensive discussion of the IREPS capabilities is presented by Hitney et al. (1981), while a discussion of the IREPS propagation models is presented by Hattan (1982).

  7. ATMOSPHERIC CIRCULATION OF HOT JUPITERS: INSENSITIVITY TO INITIAL CONDITIONS

    SciTech Connect

    Liu Beibei; Showman, Adam P.

    2013-06-10

    The ongoing characterization of hot Jupiters has motivated a variety of circulation models of their atmospheres. Such models must be integrated starting from an assumed initial state, which is typically taken to be a wind-free, rest state. Here, we investigate the sensitivity of hot-Jupiter atmospheric circulation to initial conditions with shallow-water models and full three-dimensional models. Those models are initialized with zonal jets, and we explore a variety of different initial jet profiles. We demonstrate that, in both classes of models, the final, equilibrated state is independent of initial condition-as long as frictional drag near the bottom of the domain and/or interaction with a specified planetary interior are included so that the atmosphere can adjust angular momentum over time relative to the interior. When such mechanisms are included, otherwise identical models initialized with vastly different initial conditions all converge to the same statistical steady state. In some cases, the models exhibit modest time variability; this variability results in random fluctuations about the statistical steady state, but we emphasize that, even in these cases, the statistical steady state itself does not depend on initial conditions. Although the outcome of hot-Jupiter circulation models depend on details of the radiative forcing and frictional drag, aspects of which remain uncertain, we conclude that the specification of initial conditions is not a source of uncertainty, at least over the parameter range explored in most current models.

  8. Pathways from childhood abuse and other adversities to adult health risks: The role of adult socioeconomic conditions.

    PubMed

    Font, Sarah A; Maguire-Jack, Kathryn

    2016-01-01

    Adverse childhood experiences (ACEs), including child abuse, have been linked with poor health outcomes in adulthood. The mechanisms that explain these relations are less understood. This study assesses whether associations of ACEs and health risks are mediated by adult socioeconomic conditions, and whether these pathways are different for maltreatment than for other types of adversities. Using the Behavioral Risk Factor Surveillance System 2012 survey (N=29,229), we employ structural equation modeling to (1) estimate associations of the number and type of ACEs with five health risks-depression, obesity, tobacco use, binge drinking, and self-reported sub-optimal health; and (2) assess whether adult socioeconomic conditions-marriage, divorce and separation, educational attainment, income and insurance status-mediate those associations. Findings suggest both direct and indirect associations between ACEs and health risks. At high numbers of ACEs, 15-20% of the association between number of ACEs and adult health risks was attributable to socioeconomic conditions. Associations of three ACEs (exposure to domestic violence, parental divorce, and residing with a person who was incarcerated) with health risks were nearly entirely explained by socioeconomic conditions in adulthood. However, child physical, emotional, and sexual abuse were significantly associated with several adult health risks, beyond the effects of other adversities, and socioeconomic conditions explained only a small portion of these associations. These findings suggest that the pathways to poor adult health differ by types of ACEs, and that childhood abuse is more likely than other adversities to have a direct impact. PMID:26059537

  9. Atmospheric Dispersion Model Validation in Low Wind Conditions

    SciTech Connect

    Sawyer, Patrick

    2007-11-01

    Atmospheric plume dispersion models are used for a variety of purposes including emergency planning and response to hazardous material releases, determining force protection actions in the event of a Weapons of Mass Destruction (WMD) attack and for locating sources of pollution. This study provides a review of previous studies that examine the accuracy of atmospheric plume dispersion models for chemical releases. It considers the principles used to derive air dispersion plume models and looks at three specific models currently in use: Aerial Location of Hazardous Atmospheres (ALOHA), Emergency Prediction Information Code (EPIcode) and Second Order Closure Integrated Puff (SCIPUFF). Results from this study indicate over-prediction bias by the EPIcode and SCIPUFF models and under-prediction bias by the ALOHA model. The experiment parameters were for near field dispersion (less than 100 meters) in low wind speed conditions (less than 2 meters per second).

  10. Predictability in France : atmospheric forcing or land surface initial conditions?

    NASA Astrophysics Data System (ADS)

    Singla, S.; Martin, E.; Céron, J.-P.; Regimbeau, F.

    2010-09-01

    A first study of a hydrological forecasting suite has already been done at seasonal time scales over France (Céron and al., 2010) in a context of adaptation for water resources management. The results showed the feasibility of hydrological seasonal forecasts by forcing the hydrometeorological model Safran-Isba-Modcou (SIM) with seasonal atmospheric forecasts from the DEMETER project. Scores were better for hydrological variables than for atmospheric variables for four river catchments for the spring season. The purpose of the present study is to quantify the sources of predictability of the hydrometeorological system. Two experiences were conducted in order to address this issue. The first experience consisted in testing the impact of the land surface initial conditions. We used realistic land surface initial state produced by the operational SIM model for the specific year and 9 random years of Safran atmospheric analyses (temperature and precipitation) from 1971 to 2001, in a consistent way with the previous study (Céron et al, 2010). The other atmospheric parameters (wind, specific humidity, long wave and short wave radiation and cloudiness) come from the SAFRAN climatology over the same period. The second experience was designed to evaluate the impact of the atmospheric forcing with 9 random years, chosen for the land surface initial state. The atmospheric forcing (temperature and precipitation) comes from the Safran analysis system for the corresponding year. Some results of this study will be presented on soil wetness index (SWI) forecasts and river flows forecasts for all stations in France. We will compare deterministic and probabilistic scores of the two experiences with those of the hydrological forecasting suite built with the seasonal forecasts from the DEMETER project. Perspectives for the downscaling of seasonal forecasts will be discussed in a last part. Céron J-P, Tanguy G, Franchistéguy L, Martin E, Regimbeau F and Vidal J-P, 2010. Hydrological

  11. Multiphase Chemistry of Pyruvic Acid Under Atmospherically Relevant Conditions

    NASA Astrophysics Data System (ADS)

    Vaida, V.; Monod, A.; Doussin, J. F.; Reed Harris, A. E.; Griffith, E. C.; Kroll, J. A.; Rapf, R.

    2014-12-01

    Chemistry in the natural environment proceeds in multiple phases and is subject to effects from atmospheric constituents and conditions. This presentation will use pyruvic acid as a case study to demonstrate the complexity of atmospheric multiphase chemistry. The photophysics and photochemistry of pyruvic acid proceeds on different potential energy surfaces with different reaction mechanisms, rates, and products in gas versus the aqueous phase. While the gas phase reaction generally decreases the complexity of products, the aqueous chemistry creates higher molecular weight, surface-active compounds. The studies presented involve a combination of laboratory studies that focus on the photochemistry of pyruvic acid in both the gas and aqueous phases. Further, experiments in an environmental simulation chamber (CESAM) that follow the photochemistry chemistry of pyruvic acid under atmospherically relevant conditions will be presented to highlight the effect of pressure, oxygen, relative humidity, and phase on the photochemistry of pyruvic acid. The results provide new input for atmospheric chemistry models that is required to better describe the behavior of α-keto acids in the environment.

  12. Tracking near-surface atmospheric conditions using an infrasound network.

    PubMed

    Marcillo, O; Johnson, J B

    2010-07-01

    Continuous volcanic infrasound signal was recorded on a three-microphone network at Kilauea in July 2008 and inverted for near-surface horizontal winds. Inter-station phase delays, determined by signal cross-correlation, vary by up to 4% and are attributable to variable atmospheric conditions. The results suggest two predominant weather regimes during the study period: (1) 6-9 m/s easterly trade winds and (2) lower-intensity 2-5 m/s mountain breezes from Mauna Loa. The results demonstrate the potential of using infrasound for tracking local averaged meteorological conditions, which has implications for modeling plume dispersal and quantifying gas flux. PMID:20649183

  13. Kinetics of OH + CO reaction under atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Hynes, A. J.; Wine, P. H.; Ravishankara, A. R.

    1986-01-01

    A pulsed laser photolysis-pulsed laser-induced fluorescence technique is used to directly measure the temperature, pressure, and H2O concentration dependence on k1 in air. K1 is found to increase linearly with increasing pressure at pressures of not greater than 1 atm, and the pressure dependence of k1 at 299 K is the same in N2 buffer gas as in O2 buffer gas. The rate constant in the low-pressure limit and the slope of the k1 versus pressure dependence are shown to be the same at 262 K as at 299 K. The present results significantly reduce the current atmospheric model uncertainties in the temperature dependence under atmospheric conditions, in the third body efficiency of O2, and in the effect of water vapor on k1.

  14. Properties of wind turbine wakes under various atmospheric stability conditions

    NASA Astrophysics Data System (ADS)

    Xie, Shengbai; Archer, Cristina

    2015-11-01

    Large-eddy simulations (LES) are performed to study the properties of wind turbine wakes under various atmospheric stability conditions. The Wind Turbine and Turbulence Simulator (WiTTS), a 4th-order finite-difference LES code is used for stable, neutral, and unstable conditions. The Coriolis forcing is also considered. Three cases are studied: isolated turbine, finite-size turbine array, and infinite wind farm. The results show strong correlations with stability. For the stable condition, the power extraction by an isolated turbine is highest, but the wake is also longest, thus the relative performance inside the array is lowest. In contrast, although the single-turbine power extraction is low for the unstable condition, the performance of downstream turbines is improved due to faster wake recovery. The wake shape is distorted by the stability-related wind veering. Therefore, the self-similar Gaussian wake deficit is not accurate. Here, a new wake model is proposed for correction. The infinite wind-farm case shows that the temperature near the ground is warmed by about 1 K for the stable condition, but the influence is almost negligible for the unstable and neutral conditions. For all conditions, the near-ground shear stress is reduced.

  15. Alteration of municipal and industrial slags under atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Rafał Kowalski, Piotr; Michalik, Marek

    2014-05-01

    The Waste Management System in Poland is being consequently built since 1998. After important changes in legislation, local governments have taken over the duty of waste collection. New points of selective collection of wastes have been opened and new sorting and composting plants were built. The last stage of introducing the Waste Management System is construction of waste incineration power plants. From nine installations which were planned, six are now under construction and they will start operating within the next two years. It is assumed that the consumption of raw wastes for these installations will reach 974 thousand tons per year. These investments will result in increased slags and ashes production. Now in Poland several local waste incinerators are operating and predominant amount of produced incineration residues is landfilled. These materials are exposed to atmospheric conditions in time of short term storage (just after incineration) and afterwards for a longer period of time on the landfill site. During the storage of slags low temperature mineral transformations and chemical changes may occur and also some components can be washed out. These materials are stored wet because of the technological processes. The aim of this study is to investigate the influence of storage in atmospheric conditions on slags from incineration of industrial and municipal wastes. The experiment started in January 2013. During this period slag samples from incineration of industrial and municipal wastes were exposed to atmospheric conditions. Samples were collected after 6 and 12 months. Within this time the pH value was measured monthly, and during the experimental period remained constant on the level of 9.5. After 6 months of exposure only slight changes in mineral compositions were observed in slags. The results of XRD analysis of municipal slags showed increase in content of carbonate minerals in comparison to the raw slag samples. In industrial slags, a decrease in

  16. Documentation of Atmospheric Conditions During Observed Rising Aircraft Wakes

    NASA Technical Reports Server (NTRS)

    Zak, J. Allen; Rodgers, William G., Jr.

    1997-01-01

    Flight tests were conducted in the fall of 1995 off the coast of Wallops Island, Virginia in order to determine characteristics of wake vortices at flight altitudes. A NASA Wallops Flight Facility C130 aircraft equipped with smoke generators produced visible wakes at altitudes ranging from 775 to 2225 m in a variety of atmospheric conditions, orientations (head wind, cross wind), and airspeeds. Meteorological and aircraft parameters were collected continuously from a Langley Research Center OV-10A aircraft as it flew alongside and through the wake vortices at varying distances behind the C130. Meteorological data were also obtained from special balloon observations made at Wallops. Differential GPS capabilities were on each aircraft from which accurate altitude profiles were obtained. Vortices were observed to rise at distances beyond a mile behind the C130. The maximum altitude was 150 m above the C130 in a near neutral atmosphere with significant turbulence. This occurred from large vertical oscillations in the wakes. There were several cases when vortices did not descend after a very short initial period and remained near generation altitude in a variety of moderately stable atmospheres and wind shears.

  17. Atmospheric conditions at Cerro Armazones derived from astronomical data

    NASA Astrophysics Data System (ADS)

    Lakićević, Maša; Kimeswenger, Stefan; Noll, Stefan; Kausch, Wolfgang; Unterguggenberger, Stefanie; Kerber, Florian

    2016-04-01

    Aims: We studied the precipitable water vapour (PWV) content near Cerro Armazones and discuss the potential use of our technique of modelling the telluric absorbtion lines for the investigation of other molecular layers. The site is designated for the European Extremely Large Telescope (E-ELT) and the nearby planned site for the Čerenkov Telescope Array (CTA). Methods: Spectroscopic data from the Bochum Echelle Spectroscopic Observer (BESO) instrument were investigated by using a line-by-line radiative transfer model (LBLRTM) for the Earth's atmosphere with the telluric absorption correction tool molecfit. All observations from the archive in the period from December 2008 to the end of 2014 were investigated. The dataset completely covers the El Niño event registered in the period 2009-2010. Models of the 3D Global Data Assimilation System (GDAS) were used for further comparison. Moreover, we present a direct comparison for those days for which data from a similar study with VLT/X-Shooter and microwave radiometer LHATPRO at Cerro Paranal are available. Results: This analysis shows that the site has systematically lower PWV values, even after accounting for the decrease in PWV expected from the higher altitude of the site with respect to Cerro Paranal, using the average atmosphere found with radiosondes. We found that GDAS data are not a suitable basis for predicting local atmospheric conditions - they usually systematically overestimate the PWV values. The large sample furthermore enabled us to characterize the site with respect to symmetry across the sky and variation with the years and within the seasons. This technique of studying the atmospheric conditions is shown to be a promising step into a possible monitoring equipment for the CTA. Based on archival observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile and of the Cerro Armazones Observatory facilities of the Ruhr Universität Bochum.Full Table 1

  18. 30 CFR 285.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 285.816 Section 285.816 Mineral Resources..., pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or...

  19. Inferring atmospheric weather conditions in volcanic environments using infrasound

    NASA Astrophysics Data System (ADS)

    Ortiz, H. D.; Johnson, J. B.; Ruiz, M. C.

    2015-12-01

    We use infrasound produced by Tungurahua Volcano (Ecuador) to infer local time-varying atmospheric conditions, which can be used to improve gas flux measurements and tephra dispersal modeling. Physical properties of the atmosphere, including wind and temperature (which controls adiabatic sound speed), can be quantified by studying the travel times of acoustic waves produced during volcanic activity. The travel times between Tungurahua's vent and five infrasound stations located in a network configuration over an area of 90 km2 were used in this study. We are able to quantify the arrival time differences of acoustic waves for ten unique station pairs and use this information to model the average speed of sound between source and receiver. To identify what parameters best fit the observed arrival times, we perform a grid search for a homogeneous two-dimensional wind velocity as well as for air temperature. Due to travel time dependence on the specific path taken by waves, we account for topography using a 5 meter resolution digital elevation model of Tungurahua. To investigate the time-varying atmospheric structure we use data recorded at Tungurahua volcano, during a strombolian eruptive phase in August 2012, however the methodology can be applied to continuous network infrasound data collected since July 2006 as part of the Japanese-Ecuadorian Cooperation Project: "Enhancement of the Volcano Monitoring Capacity in Ecuador". We propose that the computation of wind velocities will help to improve gas flux measurements that are based on remote sensing techniques like Differential Optical Absorption Spectroscopy (DOAS), resulting in better estimates of sulfur fluxes that can then be related to magma fluxing into the volcanic system. Further, wind field quantification close to the volcano can improve numerical models that are used to forecast tephra deposits, thereby helping to mitigate their effect on inhabitants, infrastructure, livestock, and crops.

  20. Ozonation of isoproturon adsorbed on silica particles under atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Pflieger, Maryline; Grgić, Irena; Kitanovski, Zoran

    2012-12-01

    The results on heterogeneous ozonation of a phenylurea pesticide, isoproturon, under atmospheric conditions are presented for the first time in the present study. The study was carried out using an experimental device previously adopted and validated for the heterogeneous reactivity of organics toward ozone (Pflieger et al., 2011). Isoproturon was adsorbed on silica particles via a liquid-to-solid equilibrium with a load far below a monolayer (0.02% by weight/surface coverage of 0.5%). The rate constants were estimated by measuring the consumption of the organic (dark, T = 26 °C, RH < 1%). The experimental data were fitted by both the modified Langmuir-Hinshelwood and the Eley-Rideal patterns, resulting in atmospheric lifetimes of heterogeneous ozonation of 4 and 6 days, respectively (for 40 ppb of O3). Parameters, such as the number and the quantity of pesticides adsorbed on the solid support, which can significantly influence the heterogeneous kinetics, were investigated as well. The results obtained suggest that the organic compound is adsorbed in multilayer aggregates on the aerosol even though submonolayer coverage is assumed. The presence of a second herbicide, trifluralin, together with isoproturon on the aerosol surface does not affect the kinetics of ozonation, indicating that both compounds are adsorbed on different surface sites of silica particles.

  1. Refraction effects under atmospheric stable conditions in coastal environments

    NASA Astrophysics Data System (ADS)

    Claverie, Jacques; Dion, Denis; Stein, Karin

    2007-10-01

    The performances of Electro-Optical (EO) systems such as visible or infrared cameras, lasers, operating within the Marine Surface Boundary Layer (MSBL), i.e. at heights up to a few tens of meters above the sea surface, are disturbed by various propagation mechanisms: molecular attenuation, aerosol extinction, refraction and turbulence. Refraction is responsible for focusing and defocusing of rays, detection range limitations, mirage formation and angular deviation. These refraction phenomena can be efficiently described using ray-tracing in conjunction with bulk estimations of the refractivity profiles based on the Monin-Obukhov (MO) theory. For stable atmospheric conditions (i.e. air temperature greater than sea temperature), the accuracy of the model predictions has been strongly discussed in the recent years. By using measurements of apparent target elevations recorded during the VAMPIRA trial, this paper aims at clarifying this discussion.

  2. Filter Media Tests Under Simulated Martian Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.

    2016-01-01

    Human exploration of Mars will require the optimal utilization of planetary resources. One of its abundant resources is the Martian atmosphere that can be harvested through filtration and chemical processes that purify and separate it into its gaseous and elemental constituents. Effective filtration needs to be part of the suite of resource utilization technologies. A unique testing platform is being used which provides the relevant operational and instrumental capabilities to test articles under the proper simulated Martian conditions. A series of tests were conducted to assess the performance of filter media. Light sheet imaging of the particle flow provided a means of detecting and quantifying particle concentrations to determine capturing efficiencies. The media's efficiency was also evaluated by gravimetric means through a by-layer filter media configuration. These tests will help to establish techniques and methods for measuring capturing efficiency and arrestance of conventional fibrous filter media. This paper will describe initial test results on different filter media.

  3. Higher order correlation beams in atmosphere under strong turbulence conditions.

    PubMed

    Avetisyan, H; Monken, C H

    2016-02-01

    Higher order correlation beams, that is, two-photon beams obtained from the process of spontaneous parametric down-conversion pumped by Hermite-Gauss or Laguerre-Gauss beams of any order, can be used to encode information in many modes, opening the possibility of quantum communication with large alphabets. In this paper we calculate, analytically, the fourth-order correlation function for the Hermite-Gauss and Laguerre-Gauss coherent and partially coherent correlation beams propagating through a strong turbulent medium. We show that fourth-order correlation functions for correlation beams have, under certain conditions, expressions similar to those of intensities of classical beams and are degraded by turbulence in a similar way as the classical beams. Our results can be useful in establishing limits for the use of two-photon beams in quantum communications with larger alphabets under atmospheric turbulence. PMID:26906808

  4. Correlations between the behavior of recreational horses, the physiological parameters and summer atmospheric conditions.

    PubMed

    Janczarek, Iwona; Wilk, Izabela; Zalewska, Edyta; Bocian, Krzysztof

    2015-07-01

    The aim of this paper was to select atmospheric factors and their values, which may disrupt the correct behavior and physiological condition of recreational horses. The studies were carried out from 1 July until 1 September on 16 Anglo-Arabian geldings. Each day, from 09.00 to 10.00 hours, the horses worked under saddle. The riders and the authors gave a qualitative behavioral assessment for each horse. Mood and willingness to work were evaluated. The quantitative assessment was called 'incorrect behavior of the horse while riding' (IBHR). The percentage time of duration and the number of occurrences of the features while riding were calculated. Heart rate, body temperature and respiratory rate were taken at 08.00 hours (resting measurement) and at 10.05 hours (post-exercise measurement). Air temperature, relative air humidity, wind speed and atmospheric pressure were measured at 08.00 and 10.00 hours. The results showed that adverse changes in the behavior of recreational horses can occur if the horse is ridden when the air temperature is above 26°C and when wind speeds exceed 5.5 m/s. Such conditions may cause a reduction in the mood and willingness to work in horses. Physiological parameters like heart rate and body temperature seem to be more sensitive indicators of the horse body reaction to the weather than behavioral reactions. PMID:25488802

  5. Formation of aerobic granular sludge under adverse conditions: low DO and high ammonia.

    PubMed

    Zhang, Sheng-Hua; Zhang, Xiao-Hu; Lv, Lu; Wang, Qing; Jiang, Qipei

    2013-04-01

    In this study, two adverse environments: low dissolved oxygen (DO) and high ammonia concentration, were employed to investigate the morphology, interspecies quorum sensing, extracellular polymers (EPS) characterization and microbial communities in the formation of aerobic granular sludge. Results showed that low DO could promote filamentous bacterial outgrowth. Under high ammonia concentration aerobic granular sludge (AGS) could still be cultivated, although it was looser and lighter than the control group. During the early stage of the AGS cultivation process, Al-2 activity reached a peak value in all three reactors, and ultrasonic pre-treatment was not beneficial to the release of Al-2. During AGS formation, the production of polysaccharide exhibited increases from 12.2% to 40.3%, 49.6%, and 29.3%. And PS in R2 was the highest as the result of sludge bulking. PS/PN was 1.5 to approximately 8 in the three reactors. Three-dimensional EEM fuorescence spectroscopy variation indicated the change of protein in EPS, and the highest intensity of Peak T1 was obtained. The location shift of Peak T1 was not obvious, and Peaks A, C, and T2 shifted toward longer wavelengths (red shift) of 5 to approximately 60 nm, or shorter wavelengths (blue shift) of 10 to approximately 25 nm on the emission scale and/or excitation scale in all three reactors. This provided spectral information on the chemical structure changes. Bacteria in R3 had the highest species diversity, and all bacteria in beta-Proteobacteria were identified as genus Thauera, which suggested that simultaneous nitrification and denitrification occurred in R3. The filamentous bacteria in seed sludge and R2 were species-richer. There was a low abundance of filamentous bacteria in R1 and R3, which contributed to the granule structure stability. PMID:24620612

  6. Effects of atmospheric conditions on ice nucleation activity of Pseudomonas

    NASA Astrophysics Data System (ADS)

    Attard, E.; Yang, H.; Delort, A.-M.; Amato, P.; Pöschl, U.; Glaux, C.; Koop, T.; Morris, C. E.

    2012-11-01

    Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

  7. Effects of atmospheric conditions on ice nucleation activity of Pseudomonas

    NASA Astrophysics Data System (ADS)

    Attard, E.; Yang, H.; Delort, A.-M.; Amato, P.; Pöschl, U.; Glaux, C.; Koop, T.; Morris, C. E.

    2012-04-01

    Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

  8. Adverse foraging conditions may impact body mass and survival of a high Arctic seabird

    USGS Publications Warehouse

    Harding, A.M.A.; Welcker, J.; Steen, H.; Hamer, K.C.; Kitaysky, A.S.; Fort, J.; Talbot, S.L.; Cornick, L.A.; Karnovsky, N.J.; Gabrielsen, G.W.; Gremillet, D.

    2011-01-01

    Tradeoffs between current reproduction and future survival are widely recognized, but may only occur when food is limited: when foraging conditions are favorable, parents may be able to reproduce without compromising their own survival. We investigated these tradeoffs in the little auk (Alle alle), a small seabird with a single-egg clutch. During 2005-2007, we examined the relationship between body mass and survival of birds breeding under contrasting foraging conditions at two Arctic colonies. We used corticosterone levels of breeding adults as a physiological indicator of the foraging conditions they encountered during each reproductive season. We found that when foraging conditions were relatively poor (as reflected in elevated levels of corticosterone), parents ended the reproductive season with low body mass and suffered increased post-breeding mortality. A positive relationship between body mass and post-breeding survival was found in one study year; light birds incurred higher survival costs than heavy birds. The results of this study suggest that reproducing under poor foraging conditions may affect the post-breeding survival of long-lived little auks. They also have important demographic implications because even a small change in adult survival may have a large effect on populations of long-lived species. ?? 2011 Springer-Verlag.

  9. Compensating image degradation due to atmospheric turbulence in anisoplanatic conditions

    NASA Astrophysics Data System (ADS)

    Huebner, Claudia S.

    2009-05-01

    In imaging applications the prevalent effects of atmospheric turbulence comprise image dancing and image blurring. Suggestions from the field of image processing to compensate for these turbulence effects and restore degraded imagery include Motion-Compensated Averaging (MCA) for image sequences. In isoplanatic conditions, such an averaged image can be considered as a non-distorted image that has been blurred by an unknown Point Spread Function (PSF) of the same size as the pixel motions due to the turbulence and a blind deconvolution algorithm can be employed for the final image restoration. However, when imaging over a long horizontal path close to the ground, conditions are likely to be anisoplanatic and image dancing will effect local image displacements between consecutive frames rather than global shifts only. Therefore, in this paper, a locally operating variant of the MCA-procedure is proposed, utilizing Block Matching (BM) in order to identify and re-arrange uniformly displaced image parts. For the final restoration a multistage blind deconvolution algorithm is used and the corresponding deconvolution results are presented and evaluated.

  10. Contact mechanics of modular metal-on-polyethylene total hip replacement under adverse edge loading conditions.

    PubMed

    Hua, Xijin; Li, Junyan; Wang, Ling; Jin, Zhongmin; Wilcox, Ruth; Fisher, John

    2014-10-17

    Edge loading can negatively impact the biomechanics and long-term performance of hip replacements. Although edge loading has been widely investigated for hard-on-hard articulations, limited work has been conducted for hard-on-soft combinations. The aim of the present study was to investigate edge loading and its effect on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR). A three-dimensional finite element model was developed based on a modular MoP bearing. Different cup inclination angles and head lateral microseparation were modelled and their effect on the contact mechanics of the modular MoP hip replacement were examined. The results showed that lateral microseparation caused loading of the head on the rim of the cup, which produced substantial increases in the maximum von Mises stress in the polyethylene liner and the maximum contact pressure on both the articulating surface and backside surface of the liner. Plastic deformation of the liner was observed under both standard conditions and microseparation conditions, however, the maximum equivalent plastic strain in the liner under microseparation conditions of 2000 µm was predicted to be approximately six times that under standard conditions. The study has indicated that correct positioning the components to avoid edge loading is likely to be important clinically even for hard-on-soft bearings for THR. PMID:25218504

  11. Contact mechanics of modular metal-on-polyethylene total hip replacement under adverse edge loading conditions

    PubMed Central

    Hua, Xijin; Li, Junyan; Wang, Ling; Jin, Zhongmin; Wilcox, Ruth; Fisher, John

    2014-01-01

    Edge loading can negatively impact the biomechanics and long-term performance of hip replacements. Although edge loading has been widely investigated for hard-on-hard articulations, limited work has been conducted for hard-on-soft combinations. The aim of the present study was to investigate edge loading and its effect on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR). A three-dimensional finite element model was developed based on a modular MoP bearing. Different cup inclination angles and head lateral microseparation were modelled and their effect on the contact mechanics of the modular MoP hip replacement were examined. The results showed that lateral microseparation caused loading of the head on the rim of the cup, which produced substantial increases in the maximum von Mises stress in the polyethylene liner and the maximum contact pressure on both the articulating surface and backside surface of the liner. Plastic deformation of the liner was observed under both standard conditions and microseparation conditions, however, the maximum equivalent plastic strain in the liner under microseparation conditions of 2000 µm was predicted to be approximately six times that under standard conditions. The study has indicated that correct positioning the components to avoid edge loading is likely to be important clinically even for hard-on-soft bearings for THR. PMID:25218504

  12. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia.

    PubMed

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m(3)) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m(3). Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration. PMID:22410823

  13. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    NASA Astrophysics Data System (ADS)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  14. 30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 585.816 Section 585.816 Mineral Resources BUREAU... corrective action to BOEM within 30 days of the discovery of the adverse effect. (b) Take remedial action...

  15. 30 CFR 285.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 285.816 Section 285.816 Mineral Resources BUREAU...: (a) Submit a plan of corrective action to MMS within 30 days of the discovery of the adverse...

  16. 30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 585.816 Section 585.816 Mineral Resources BUREAU... corrective action to BOEM within 30 days of the discovery of the adverse effect. (b) Take remedial action...

  17. 30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 585.816 Section 585.816 Mineral Resources BUREAU... corrective action to BOEM within 30 days of the discovery of the adverse effect. (b) Take remedial action...

  18. A study of different indicators of Maillard reaction with whey proteins and different carbohydrates under adverse storage conditions.

    PubMed

    Leiva, Graciela E; Naranjo, Gabriela B; Malec, Laura S

    2017-01-15

    This study examined different indicators of each stage of Maillard reaction under adverse storage conditions in a system with whey proteins and lactose or glucose. The analysis of lysine loss by the o-phthaldialdehyde method can be considered a good indicator of the early stage, showing considerable differences in reactivity when systems with mono and disaccharides were analyzed. Capillary electrophoresis proved to be a sensitive method for evaluating the extent of glycosylation of the native proteins, providing valuable information when the loss of lysine was not significant. The estimation of the Amadori compound from the determination of total 5-hydroxymethyl-2-furfuraldehyde would have correlate well with reactive lysine content if the advanced stages of the reaction had not been reached. For assessing the occurrence of the intermediate and final stages, the measurement of free 5-hydroxymethyl-2-furfuraldehyde and color, proved not to be suitable for storage conditions. PMID:27542493

  19. Emerging role of angiogenin in stress response and cell survival under adverse conditions

    PubMed Central

    Li, Shuping; Hu, Guo-Fu

    2011-01-01

    Angiogenin (ANG), also known as ribonuclease (RNASE) 5, is a member of the vertebrate-specific, secreted RNASE superfamily. ANG was originally identified as a tumor angiogenic factor, but its biological activity has been extended from inducing angiogenesis to stimulating cell proliferation and more recently, to promoting cell survival. Under growth conditions, ANG is translocated to nucleus where it accumulates in nucleolus and stimulates ribosomal RNA (rRNA) transcription, thus facilitating cell growth and proliferation. Under stress conditions, ANG is accumulated in cytoplasmic compartments and modulates the production of tiRNA, a novel class of small RNA that is derived from tRNA and is induced by stress. tiRNA suppress global protein translation by inhibiting both cap-dependent and -independent translation including that mediated by weak IRESes. However, strong IRES-mediated translation, a mechanism often used by genes involved in pro-survival and anti-apoptosis, is not affected. Thus, ANG-mediated tiRNA reprogram protein translation, save anabolic energy, and promote cell survival. This recently uncovered function of ANG presents a novel mechanism of action in regulating cell growth and survival. PMID:22021078

  20. Atmospheric and oceanologic conditions favouring large bioproduction of northern Adriatic

    NASA Astrophysics Data System (ADS)

    Kraus, Romina; Lučić, Davor; Njire, Jakica; Djakovac, Tamara; Precali, Robert; Supić, Nastjenjka

    2016-04-01

    An interdisciplinary study based on long term data collected in the northern Adriatic relieved winter period to be crucial for the total annual zooplankton production in the region. Namely, yearly averages of some investigated zooplankton species in the 2000-2007 interval were highly related to their February and/or March abundances. The large winter zooplankton abundances appeared in winters of the "A type", in which freshened waters from the Po River spread over the region. Also, the production of phytoplankton was in winters of the "A type" higher than in winters of the "B type", in which these waters are restricted to the coastal areas and do not impact the open sea. That was presumably due to increase in nutrients. In fact, the total inorganic nitrogen and ortophosphate concentration in eastern part reached maximal February values in the 1990-2007 interval in winters of the "A type". Spreading of the Po River water across the northern Adriatic and appearance of the two winter types depends on the existing geostrophic circulation patterns and atmospheric and hydrologic conditions in the preceding months, thus enabling forecast. Obtained results are basis for the future theoretical ecological model which can explain long term changes in bioproduction in the region and be used in planning future environment actions aimed to sustained development, especially as winter phytoplankton and zooplankton production seems to reflect on annual catch of small pelagic fish important for Adriatic fishery, anchovy (Engraulis encrasicolus).

  1. The brain dynamics of rapid perceptual adaptation to adverse listening conditions.

    PubMed

    Erb, Julia; Henry, Molly J; Eisner, Frank; Obleser, Jonas

    2013-06-26

    Listeners show a remarkable ability to quickly adjust to degraded speech input. Here, we aimed to identify the neural mechanisms of such short-term perceptual adaptation. In a sparse-sampling, cardiac-gated functional magnetic resonance imaging (fMRI) acquisition, human listeners heard and repeated back 4-band-vocoded sentences (in which the temporal envelope of the acoustic signal is preserved, while spectral information is highly degraded). Clear-speech trials were included as baseline. An additional fMRI experiment on amplitude modulation rate discrimination quantified the convergence of neural mechanisms that subserve coping with challenging listening conditions for speech and non-speech. First, the degraded speech task revealed an "executive" network (comprising the anterior insula and anterior cingulate cortex), parts of which were also activated in the non-speech discrimination task. Second, trial-by-trial fluctuations in successful comprehension of degraded speech drove hemodynamic signal change in classic "language" areas (bilateral temporal cortices). Third, as listeners perceptually adapted to degraded speech, downregulation in a cortico-striato-thalamo-cortical circuit was observable. The present data highlight differential upregulation and downregulation in auditory-language and executive networks, respectively, with important subcortical contributions when successfully adapting to a challenging listening situation. PMID:23804092

  2. Experimental Investigation of Soil and Atmospheric Conditions on the Momentum, Mass, and Thermal Boundary Layers Above the Land Atmosphere Interface

    NASA Astrophysics Data System (ADS)

    Trautz, A.; Smits, K. M.; Illangasekare, T. H.; Schulte, P.

    2014-12-01

    The purpose of this study is to investigate the impacts of soil conditions (i.e. soil type, saturation) and atmospheric forcings (i.e. velocity, temperature, relative humidity) on the momentum, mass, and temperature boundary layers. The atmospheric conditions tested represent those typically found in semi-arid and arid climates and the soil conditions simulate the three stages of evaporation. The data generated will help identify the importance of different soil conditions and atmospheric forcings with respect to land-atmospheric interactions which will have direct implications on future numerical studies investigating the effects of turbulent air flow on evaporation. The experimental datasets generated for this study were performed using a unique climate controlled closed-circuit wind tunnel/porous media facility located at the Center for Experimental Study of Subsurface Environmental Processes (CESEP) at the Colorado School of Mines. The test apparatus consisting of a 7.3 m long porous media tank and wind tunnel, were outfitted with a sensor network to carefully measure wind velocity, air and soil temperature, relative humidity, soil moisture, and soil air pressure. Boundary layer measurements were made between the heights of 2 and 500 mm above the soil tank under constant conditions (i.e. wind velocity, temperature, relative humidity). The soil conditions (e.g. soil type, soil moisture) were varied between datasets to analyze their impact on the boundary layers. Experimental results show that the momentum boundary layer is very sensitive to the applied atmospheric conditions and soil conditions to a much less extent. Increases in velocity above porous media leads to momentum boundary layer thinning and closely reflect classical flat plate theory. The mass and thermal boundary layers are directly dependent on both atmospheric and soil conditions. Air pressure within the soil is independent of atmospheric temperature and relative humidity - wind velocity and soil

  3. Cl atom initiated oxidation of 1-alkenes under atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Walavalkar, M.; Sharma, A.; Alwe, H. D.; Pushpa, K. K.; Dhanya, S.; Naik, P. D.; Bajaj, P. N.

    2013-03-01

    In view of the importance of the oxidation pathways of alkenes in the troposphere, and the significance of Cl atom as an oxidant in marine boundary layer (MBL) and polluted industrial atmosphere, the reactions of four 1-alkenes (C6-C9) with Cl atoms are investigated. The rate coefficients at 298 K are measured to be (4.0 ± 0.5), (4.4 ± 0.7), (5.5 ± 0.9) and (5.9 ± 1.7) × 10-10 cm3 molecule-1 s-1 for 1-hexene, 1-heptene, 1-octene and 1-nonene, respectively. The quoted errors include the experimental 2σ, along with the error in the reference rate coefficients. From the systematic increase in the rate coefficients with the number of carbon atoms, an approximate value for the average rate coefficient for hydrogen abstraction per CH2 group in alkenes is estimated to be (4.9 ± 0.3) × 10-11 cm3 molecule-1 s-1. Based on these rate coefficients, the contribution of Cl atom reactions towards the degradation of these molecules is found to be comparable to that of OH radical reactions, under MBL conditions. The products identified in gas phase indicate that Cl atom addition occurs mainly at the terminal carbon, leading to the formation of 1-chloro-2-ketones and 1-chloro-2-ols. The major gas phase products from the alkenyl radicals (formed by H atom abstraction) are different positional isomers of long chain enols and enones. A preference for dissociation leading to an allyl radical, resulting in aldehydes, lower by three carbon atoms, is indicated. The observed relative yields suggest that in general, the increased contribution of the reactions of Cl atoms towards degradation of 1-alkenes in NOx free air does not result in an increase in the generation of small aldehydes (carbon number < 4), including chloroethanal, as compared to that in the reaction of 1-butene.

  4. Geospatial Strategy for Adverse Impact of Urban Heat Island in upper atmospheres of the earth Mountain Areas using LANDSAT ETM+ Sensors

    NASA Astrophysics Data System (ADS)

    Kumar, Amit; Vandana, Vandana

    2016-07-01

    We are living in the age of the rapidly growing population and changing environmental conditions with advanced technical capacity. This has been resulting in widespread land cover change. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. Urban Heat Islands exist in many large cities especially metropolitan cities and can significantly affect the permafrost layer in mountain areas. The adverse effect of urban heat island has become the subject of numerous studies in recent decades and is reflected in many major mountain cities around the world. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to the development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The Urban Heat Island for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment of the climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The knowledge of surface temperature is important for the study of urban climate and human health. The rapid growth of industries in peri-urban areas results in excessive warming and variations in weather conditions. It leads to soil degradation in frozen areas due to high temperature which leads to melting of snow in mountain areas Remotely sensed data of thermal infrared band in the region of 10.4-12.5 µm of EMR spectrum, available from LANDSAT- ETM+ is proved to be very helpful to identify urban heat islands. Thermal infrared data acquired during the daytime and night time can be used to monitor the heat island associated with urban areas as well as atmospheric pollution. The present paper describes the methodology and resolution dynamic urban heat island

  5. Does toxicity of aromatic pollutants increase under remote atmospheric conditions?

    PubMed Central

    Kroflič, Ana; Grilc, Miha; Grgić, Irena

    2015-01-01

    Aromatic compounds contribute significantly to the budget of atmospheric pollutants and represent considerable hazard to living organisms. However, they are only rarely included into atmospheric models which deviate substantially from field measurements. A powerful experimental-simulation tool for the assessment of the impact of low- and semi-volatile aromatic pollutants on the environment due to their atmospheric aqueous phase aging has been developed and introduced for the first time. The case study herein reveals that remote biotopes might be the most damaged by wet urban guaiacol-containing biomass burning aerosols. It is shown that only after the primary pollutant guaiacol has been consumed, its probably most toxic nitroaromatic product is largely formed. Revising the recent understanding of atmospheric aqueous phase chemistry, which is mostly concerned with the radical nitration mechanisms, the observed phenomenon is mainly attributed to the electrophilic nitrogen-containing reactive species. Here, their intriguing role is closely inspected and discussed from the ecological perspective. PMID:25748923

  6. Does toxicity of aromatic pollutants increase under remote atmospheric conditions?

    NASA Astrophysics Data System (ADS)

    Kroflič, Ana; Grilc, Miha; Grgić, Irena

    2015-03-01

    Aromatic compounds contribute significantly to the budget of atmospheric pollutants and represent considerable hazard to living organisms. However, they are only rarely included into atmospheric models which deviate substantially from field measurements. A powerful experimental-simulation tool for the assessment of the impact of low- and semi-volatile aromatic pollutants on the environment due to their atmospheric aqueous phase aging has been developed and introduced for the first time. The case study herein reveals that remote biotopes might be the most damaged by wet urban guaiacol-containing biomass burning aerosols. It is shown that only after the primary pollutant guaiacol has been consumed, its probably most toxic nitroaromatic product is largely formed. Revising the recent understanding of atmospheric aqueous phase chemistry, which is mostly concerned with the radical nitration mechanisms, the observed phenomenon is mainly attributed to the electrophilic nitrogen-containing reactive species. Here, their intriguing role is closely inspected and discussed from the ecological perspective.

  7. Summer atmospheric conditions over the Japan/East Sea

    NASA Astrophysics Data System (ADS)

    Dorman, C. E.; Beardsley, R. C.; Limeburner, R.; Varlamov, S. M.; Caruso, M.; Dashko, N. A.

    2005-06-01

    Atmospheric conditions over the Japan/East Sea (JES) during the 1999 warm season (May-August) were investigated using research vessel surface and sounding observations in conjunction with coastal station and moored buoy meteorological data. In the broad center of the sea, surface winds were weak and variable with a tendency to be northward in direction. Air temperatures were close to the sea-surface temperature but warmer on average. The lower atmospheric profiles were weakly unstable or stable with shallow inversions. The summer surface heat flux was dominated by radiation components. The large solar short-wave flux caused a large net gain of heat by the sea that was unchecked by the weaker, long-wave flux. Sensible and latent heat fluxes were both small due to modest air-sea temperature differences and weak winds. The surface wind stress was also weak. European Center for Medium-range Weather Forecasting (ECMWF) model surface fields compare favorably with our ship measurements in both summer of 1999 and the winter of 2000. The ECMWF model analysis followed the observed synoptic scale variations well but missed smaller scale variations. The ECMWF air temperature, dew point, pressure, wind speed, and wind direction were correlated with ship values at 0.8 or better. ECMWF forecasts and ship measurements of surface heat fluxes were well related. In the center of the JES, net fluxes in the winter and summer were correlated to 0.7-0.9, with winter the greater. ECMWF short-wave heat flux tended to exceed the ship-based values by 25-55 W/m 2. ECMWF wind stress magnitude was best correlated with winter ship measurements, with correlations that reached 0.76-0.89, while wind stress components were more poorly correlated. In both seasons, ECMWF underestimated the wind stress by 15-25%. Monthly mean climatologies of the JES surface heat flux and wind stress were computed using the 1991-2001 ECMWF surface flux time series. The annual heat flux cycle varies from a maximum

  8. Reported respiratory symptoms and adverse home conditions after 9/11 among residents living near the World Trade Center.

    PubMed

    Lin, Shao; Jones, Rena; Reibman, Joan; Bowers, James; Fitzgerald, Edward F; Hwang, Syni-An

    2007-05-01

    This study investigated whether self-reported damage, dust, and odors in homes near the World Trade Center (WTC) after September 11, 2001, were related to increased rates of respiratory symptoms among residents and if multiple sources of exposure were associated with greater health risk. We mailed questionnaires to homes within 1.5 km of the WTC site (affected area) and in upper Manhattan (control area). Surveys asked about respiratory symptoms, unplanned medical visits, physician diagnoses, medication use, and conditions in the home after 9/11. Adverse home conditions were associated with new-onset (i.e., began after 9/11) and persistent (i.e., remained 1 year after 9/11) upper and lower respiratory symptoms in the affected area (Cumulative Incidence Ratios [CIRs] 1.20-1.71). Residents reporting longer duration of dust/odors or multiple sources of exposure had greater risk for symptoms compared to those reporting shorter duration and fewer sources. These data suggest that WTC-related contamination in the home after 9/11 was associated with new and persistent respiratory symptoms among residents living near the site. While we cannot eliminate potential biases related to self-reported data, we took strategies to minimize their impact, and the observed effects are biologically plausible. PMID:17530533

  9. Thermophysical Properties Measurement of High-Temperature Liquids Under Microgravity Conditions in Controlled Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Watanabe, Masahito; Ozawa, Shumpei; Mizuno, Akotoshi; Hibiya, Taketoshi; Kawauchi, Hiroya; Murai, Kentaro; Takahashi, Suguru

    2012-01-01

    Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the oscillating drop method with an electromagnetic levitation (EML) device. Thus, we are preparing the experiments of thermophysical properties measurements using the Materials-Science Laboratories ElectroMagnetic-Levitator (MSL-EML) facilities in the international Space station (ISS). Recently, it has been identified that dependence of surface tension on oxygen partial pressure (Po2) must be considered for industrial application of surface tension values. Effect of Po2 on surface tension would apparently change viscosity from the damping oscillation model. Therefore, surface tension and viscosity must be measured simultaneously in the same atmospheric conditions. Moreover, effect of the electromagnetic force (EMF) on the surface oscillations must be clarified to obtain the ideal surface oscillation because the EMF works as the external force on the oscillating liquid droplets, so extensive EMF makes apparently the viscosity values large. In our group, using the parabolic flight levitation experimental facilities (PFLEX) the effect of Po2 and external EMF on surface oscillation of levitated liquid droplets was systematically investigated for the precise measurements of surface tension and viscosity of high temperature liquids for future ISS experiments. We performed the observation of surface oscillations of levitated liquid alloys using PFLEX on board flight experiments by Gulfstream II (G-II) airplane operated by DAS. These observations were performed under the controlled Po2 and also under the suitable EMF conditions. In these experiments, we obtained the density, the viscosity and the surface tension values of liquid Cu. From these results, we discuss about as same as reported data, and also obtained the difference of surface oscillations with the change of the EMF conditions.

  10. Soil moisture under contrasted atmospheric conditions in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Azorin-Molina, César; Cerdà, Artemi; Vicente-Serrano, Sergio M.

    2014-05-01

    , Intraannual changes, Atmospheric parameters, Eastern Spain Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE FP7 project 603498 supported this research. References: Azorin-Molina, C., Connell, B.H., Baena-Calatrava, R. 2009. Sea-breeze convergence zones from AVHRR over the Iberian Mediterranean Area and the Isle of Mallorca, Spain. Journal of Applied Meteorology and Climatology 48 (10), 2069-2085. Azorin-Molina, C., Vicente-Serrano, S. M., Cerdà, A. 2013. Soil moisture changes in two experimental sites in Eastern Spain. Irrigation versus rainfed orchards under organic farming. EGU, Geophysical Research Abstracts, EGU2013-13286. Bodí, M.B., Mataix-Solera, J., Doerr, S.H. & Cerdà, A. 2011. The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma, 160, 599-607. 10.1016/j.geoderma.2010.11.009 Cerdà, A. 1995. Soil moisture regime under simulated rainfall in a three years abandoned field in Southeast Spain. Physics and Chemistry of The Earth, 20 (3-4), 271-279. Cerdà, A. 1999. Seasonal and spatial variations in infiltration rates in badland surfaces under Mediterranean climatic conditions. Water Resources Research, 35 (1) 319-328. Cerdà, A. 2002. The effect of season and parent material on water erosion on highly eroded soils in eastern Spain. Journal of Arid Environments, 52, 319-337. García-Fayos, P. García-Ventoso, B. Cerdà, A. 2000. Limitations to Plant establishment on eroded slopes in Southeastern Spain. Journal of Vegetation Science, 11- 77- 86. Ghafoor, A., Murtaza, G., Rehman, M. Z., Saifullah Sabir, M. 2012. Reclamation and salt leaching efficiency for tile drained saline-sodic soil using marginal quality water for irrigating rice and wheat crops. Land Degradation & Development, 23: 1 -9. DOI 10.1002/ldr.1033 Johnston, C. R., Vance, G. F., Ganjegunte, G. K. 2013. Soil properties changes following irrigation with coalbed natural

  11. Soil moisture under contrasted atmospheric conditions in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Azorin-Molina, César; Cerdà, Artemi; Vicente-Serrano, Sergio M.

    2014-05-01

    , Intraannual changes, Atmospheric parameters, Eastern Spain Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE FP7 project 603498 supported this research. References: Azorin-Molina, C., Connell, B.H., Baena-Calatrava, R. 2009. Sea-breeze convergence zones from AVHRR over the Iberian Mediterranean Area and the Isle of Mallorca, Spain. Journal of Applied Meteorology and Climatology 48 (10), 2069-2085. Azorin-Molina, C., Vicente-Serrano, S. M., Cerdà, A. 2013. Soil moisture changes in two experimental sites in Eastern Spain. Irrigation versus rainfed orchards under organic farming. EGU, Geophysical Research Abstracts, EGU2013-13286. Bodí, M.B., Mataix-Solera, J., Doerr, S.H. & Cerdà, A. 2011. The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma, 160, 599-607. 10.1016/j.geoderma.2010.11.009 Cerdà, A. 1995. Soil moisture regime under simulated rainfall in a three years abandoned field in Southeast Spain. Physics and Chemistry of The Earth, 20 (3-4), 271-279. Cerdà, A. 1999. Seasonal and spatial variations in infiltration rates in badland surfaces under Mediterranean climatic conditions. Water Resources Research, 35 (1) 319-328. Cerdà, A. 2002. The effect of season and parent material on water erosion on highly eroded soils in eastern Spain. Journal of Arid Environments, 52, 319-337. García-Fayos, P. García-Ventoso, B. Cerdà, A. 2000. Limitations to Plant establishment on eroded slopes in Southeastern Spain. Journal of Vegetation Science, 11- 77- 86. Ghafoor, A., Murtaza, G., Rehman, M. Z., Saifullah Sabir, M. 2012. Reclamation and salt leaching efficiency for tile drained saline-sodic soil using marginal quality water for irrigating rice and wheat crops. Land Degradation & Development, 23: 1 -9. DOI 10.1002/ldr.1033 Johnston, C. R., Vance, G. F., Ganjegunte, G. K. 2013. Soil properties changes following irrigation with coalbed natural

  12. Atmospheric production of glycolaldehyde under hazy prebiotic conditions.

    PubMed

    Harman, Chester E; Kasting, James F; Wolf, Eric T

    2013-04-01

    The early Earth's atmosphere, with extremely low levels of molecular oxygen and an appreciable abiotic flux of methane, could have been a source of organic compounds necessary for prebiotic chemistry. Here, we investigate the formation of a key RNA precursor, glycolaldehyde (2-hydroxyacetaldehyde, or GA) using a 1-dimensional photochemical model. Maximum atmospheric production of GA occurs when the CH4:CO2 ratio is close to 0.02. The total atmospheric production rate of GA remains small, only 1 × 10(7) mol yr(-1). Somewhat greater amounts of GA production, up to 2 × 10(8) mol yr(-1), could have been provided by the formose reaction or by direct delivery from space. Even with these additional production mechanisms, open ocean GA concentrations would have remained at or below ~1 μM, much smaller than the 1-2 M concentrations required for prebiotic synthesis routes like those proposed by Powner et al. (Nature 459:239-242, 2009). Additional production or concentration mechanisms for GA, or alternative formation mechanisms for RNA, are needed, if this was indeed how life originated on the early Earth. PMID:23695543

  13. Occurring Conditions of Atmospheric Electricity Variation during Seismic Wave Propagation

    NASA Astrophysics Data System (ADS)

    Okubo, Kan; Yamamoto, Keisuke; Takayama, Masakazu; Takeuchi, Nobunao

    We have observed the co-seismic electromagnetic phenomena such as earth potential difference (EPD) variation and atmospheric electricity (AE) variation at three observation sites in Akita Prefecture. In the strong earthquake of December 2nd, 2001, we observed clear signals of the EPD and the AE variation at all three sites. However, the amplitude of both observed signals at three sites are very different though with almost equal quake intensity at each site. The AE signal amplitude is increasing with the EPD signal one at each site. The model how both variation signals appear is proposed to explain the observed data.

  14. Atmospheric conditions, lunar phases, and childbirth: a multivariate analysis.

    PubMed

    Ochiai, Angela Megumi; Gonçalves, Fabio Luiz Teixeira; Ambrizzi, Tercio; Florentino, Lucia Cristina; Wei, Chang Yi; Soares, Alda Valeria Neves; De Araujo, Natalucia Matos; Gualda, Dulce Maria Rosa

    2012-07-01

    Our objective was to assess extrinsic influences upon childbirth. In a cohort of 1,826 days containing 17,417 childbirths among them 13,252 spontaneous labor admissions, we studied the influence of environment upon the high incidence of labor (defined by 75th percentile or higher), analyzed by logistic regression. The predictors of high labor admission included increases in outdoor temperature (odds ratio: 1.742, P = 0.045, 95%CI: 1.011 to 3.001), and decreases in atmospheric pressure (odds ratio: 1.269, P = 0.029, 95%CI: 1.055 to 1.483). In contrast, increases in tidal range were associated with a lower probability of high admission (odds ratio: 0.762, P = 0.030, 95%CI: 0.515 to 0.999). Lunar phase was not a predictor of high labor admission (P = 0.339). Using multivariate analysis, increases in temperature and decreases in atmospheric pressure predicted high labor admission, and increases of tidal range, as a measurement of the lunar gravitational force, predicted a lower probability of high admission. PMID:21744100

  15. Atmospheric conditions, lunar phases, and childbirth: a multivariate analysis

    NASA Astrophysics Data System (ADS)

    Ochiai, Angela Megumi; Gonçalves, Fabio Luiz Teixeira; Ambrizzi, Tercio; Florentino, Lucia Cristina; Wei, Chang Yi; Soares, Alda Valeria Neves; De Araujo, Natalucia Matos; Gualda, Dulce Maria Rosa

    2012-07-01

    Our objective was to assess extrinsic influences upon childbirth. In a cohort of 1,826 days containing 17,417 childbirths among them 13,252 spontaneous labor admissions, we studied the influence of environment upon the high incidence of labor (defined by 75th percentile or higher), analyzed by logistic regression. The predictors of high labor admission included increases in outdoor temperature (odds ratio: 1.742, P = 0.045, 95%CI: 1.011 to 3.001), and decreases in atmospheric pressure (odds ratio: 1.269, P = 0.029, 95%CI: 1.055 to 1.483). In contrast, increases in tidal range were associated with a lower probability of high admission (odds ratio: 0.762, P = 0.030, 95%CI: 0.515 to 0.999). Lunar phase was not a predictor of high labor admission ( P = 0.339). Using multivariate analysis, increases in temperature and decreases in atmospheric pressure predicted high labor admission, and increases of tidal range, as a measurement of the lunar gravitational force, predicted a lower probability of high admission.

  16. Separation and Conditioning of Mars Atmospheric Gases via TSA

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Luna, Bernadette (Technical Monitor)

    2000-01-01

    Space and planetary exploration almost always presents interesting and unusual engineering challenges. Separations engineering for chemical processes that are critical to humans working in space is no exception. The challenges are becoming clearer as we make the transition from concepts and planning to hardware development, and as we understand better the constraints and environments in which the processes must perform. The coming decade will see a robotic Mars exploration program that has recovered from recent setbacks and is building a knowledge and technology base for human exploration. One of the missions will carry a small chemical pilot plant for demonstrating the manufacture of rocket propellants and life support consumables from the low-pressure (0.01 atm) Martian atmosphere. By manufacturing and storing the fuel and consumables needed for human-return missions in situ, launch mass and landed mass are reduced by tons and missions become far less expensive. The front-end to the pilot plant is a solid-state atmosphere acquisition and separation unit based on temperature-swing adsorption (TSA). The unit produces purified and pressurized (to 1.0 atm) carbon dioxide to downstream reactors that will make methane and oxygen. The unit also produces a nitrogen-argon mixture as a valuable by-product for life support, inflatable structures, and propellant pressurization. With nighttime temperatures falling to -100 degrees C, power availability restricted to a few watts, and flawless operation critical to success, the dusty Martian surface is a difficult place to operate a remote plant. This talk will focus on how this TSA separation process is designed and implemented for this application, and how it might be used in the more distant future for human exploration.

  17. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1987-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and Earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorping properties of potential constituents is available. The use of theoretically derived microwave absorption properties for such atmospheric constituents, or laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurement of the microwave properties of atmospheric gases under simulated conditions for the outer planets were conducted. Results of these measurements are discussed.

  18. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1985-01-01

    Radio absorptivity data for the Venus middle atmosphere (1 to 6 atm, temperatures from 500 to 575K) obtained from spacecraft radio occultation experiments (at 3.6 to 13.4 cm wavelengths) and earth-based radio astronomical observations (1 to 3 cm wavelength range) are compared to laboratory observations at the latter wavelength range under simulated Venus conditions to infer abundances of microwave-absorbing atmospheric constituents, i.e. H2SO4 in a CO2 atmosphere.

  19. Laboratory evaluation of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1984-01-01

    The microwave absorbing properties of gaseous sulfuric acid (H2SO4) under Venus atmospheric conditions are investigated. The results are applied to measurements from Mariner 5, Mariner 10, and Pioneer/Venus Radio Occultation experiments, to determine abundancies of gaseous sulfuric acid in the Venus atmosphere. The microwave properties of the vapors accompanying liquid H2SO4 are studied to estimate the vapor pressure in an atmospheric model.

  20. Amplifying Learning through Sites of Pedagogical Practice: A Possible Effect of Working with Disciplinary Technologies in Schools Operating under Adverse Conditions

    ERIC Educational Resources Information Center

    Hayes, Debra

    2005-01-01

    Schools located within communities experiencing high levels of social dislocation, educational disadvantage and student disengagement from learning are working under "adverse conditions". These schools face particular challenges when it comes to stabilising and sustaining wholeschool change aimed at improving students' learning outcomes. In this…

  1. Laser photoacoustic trace detection of C2H4 revealing adverse environmental effects of atmospheric pollution on plant material

    NASA Astrophysics Data System (ADS)

    Harren, Frans J. M.; Petruzzelli, Luciana

    1993-03-01

    The photoacoustic detection method for trace gases in the atmosphere is well developed towards very low limits of detection, in the last years. Due to the combination of a sensitive photoacoustic cell placed intracavity in an infrared CO2 laser we were able to detect C2H4 at ultralow (< 1:1011) concentrations within 10 seconds, C2H4 in a plant hormone which seems to play an important role throughout all the life stages of a plant, including seed germination. In addition, various types of stress have been reported to promote ethylene production from different plant tissues. As part of our ongoing research on the role of ethylene in seed germination, we have compared our laser photoacoustic set-up to a gaschromatograph for measuring C2H4 produced by germinating Pisum sativum L. seeds within the first days of imbibition. C2H4 evolution by intact seeds shows a maximum at about 25 hours of germination. Thereafter, the rate of ethylene measured by gaschromatograph continues to decrease while that measured by the laser-driven photoacoustic system shows further increases. Most of the ethylene produced by seeds is found in isolated embryonic axes. The fumigation with ozone affects the growth of seedlings and their ethylene evolution.

  2. Atmospheric stability assessment for the characterization of offshore wind conditions

    NASA Astrophysics Data System (ADS)

    Sanz Rodrigo, J.; Cantero, E.; García, B.; Borbón, F.; Irigoyen, U.; Lozano, S.; Fernande, P. M.; Chávez, R. A.

    2015-06-01

    Based on the Fino-1 offshore met mast database, different instrument set-ups and methodologies for stability characterization have been tested using non-dimensional numbers like the gradient and bulk Richardson number, and their equivalences with the Obukhov parameter ζ = z/L, which can be measured locally with the use of a sonic anemometer. These equivalences depend to a large extent on the suitability of empirical stability functions obtained in horizontally-homogeneous conditions. The bulk Richardson number method, based on Grachev and Fairall (1997) empirical function, is the least demanding measurement method for stability characterization offering a more practical approach to wind farm designers than using the sonic method. Alternatively, the AMOK method, used by FUGA wake model and also based on the bulk Richardson number, assumes surface-layer theory and avoids using stability functions, which results in a more robust formulation. A 9-class stability classification based on Sorbjan and Grachev (2010) is used to generalize the categorization of wind conditions. Based on flux-profile analysis it was concluded that unfortunately the local ζ is not sufficient to describe the scaling behaviour of the stable boundary layer. Indeed, larger wind shear than predicted by classical onshore stability functions is found, probably as a result of lower boundary layer depths.

  3. Onset of atmospheric ice formation in natural conditions

    NASA Astrophysics Data System (ADS)

    Conen, Franz; Zimmermann, Lukas

    2015-04-01

    Bacteria growing on plants are the particles with the warmest freezing temperature known for natural particles (-2 oC). Their onset of freezing is known to be conditioned by themperature, growth and nutrient status, and probably other factors that can not be assessed in situ, but are also not likely to be conserved when taking airborne bacteria to the laboratory. Whether such bacteria play a role in initiating the ice phase in clouds is therefore best studied directly in a cooling air mass in the natural environment. Investigations directly at cloud tops would be desirable. A more amenable place is the bottom of a valley where a cold air pool forms during clear nights and when radiation fog is likely to form. When shallow, such fog may resemble an inverted cloud with its top on the land surface and warmer air above it. The temperature of bacteria and other particles suspended in air under a clear sky around the onset of fog formation is probably several degrees below that of the surrounding air because of radiative cooling, which will affect the particle's activation as a cloud condensation nucleus and as an ice nucleus. Hence, ice particles probably form earlier than expected at a particular air temperature, grow rapidly and parachute to the surface, where their descent can be recorded by traps charged with supercooled water. We present, and would like to discuss, this kind of observation in principle and show some first results (subject to suitable weather conditions before the presentation).

  4. Pulsed corona discharge at atmospheric and supercritical conditions

    NASA Astrophysics Data System (ADS)

    Lock, Evgeniya Hristova

    potentials, which in turn reduce the required breakdown voltages. This study provides an experimental database for pulsed streamer breakdown in supercritical conditions over a wide range of supercritical conditions.

  5. Genotype and Neuropsychological Response Inhibition as Resilience Promoters for ADHD, ODD, and CD under Conditions of Psychosocial Adversity

    PubMed Central

    Nigg, Joel; Nikolas, Molly; Friderici, Karen; Park, Leeyoung; Zucker, Robert A.

    2008-01-01

    Whereas child personality, IQ, and family factors have been identified as enabling a resilient response to psychosocial adversity, more direct biological resilience factors have been less well delineated. This is particularly so for child ADHD, which has received less attention from a resilience perspective than have associated externalizing disorders. Children from two independent samples were classified as resilient if they avoided developing ADHD, ODD, or CD in the face of family adversity. Two protective factors were examined for their potential relevance to prefrontal brain development: neuropsychological response inhibition, as assessed by the Stop task, and a composite catecholamine genotype risk score. Resilient children were characterized in both samples by more effective response inhibition, although the effect in the second sample was very small. Genotype was measured in Sample 1, and a composite high risk genotype index was developed by summing presence of risk across markers on three genes expressed in prefrontal cortex: dopamine transporter, dopamine D4 receptor, and noradrenergic alpha 2 receptor. Genotype was a reliable resilience indicator against development of ADHD and CD, but not ODD, in the face of psychosocial adversity. Results illustrate potential neurobiological protective factors related to development of prefrontal cortex that may enable children to avoid developing ADHD and CD in the presence of psychosocial adversity. PMID:17705902

  6. Adversity-induced relapse of fear: neural mechanisms and implications for relapse prevention from a study on experimentally induced return-of-fear following fear conditioning and extinction.

    PubMed

    Scharfenort, R; Menz, M; Lonsdorf, T B

    2016-01-01

    The efficacy of current treatments for anxiety disorders is limited by high relapse rates. Relapse of anxiety disorders and addiction can be triggered by exposure to life adversity, but the underlying mechanisms remain unexplored. Seventy-six healthy adults were a priori selected for the presence or absence of adverse experiences during childhood (CA) and recent past (RA; that is, past 12 months). Participants underwent fear conditioning (day 1) and fear extinction and experimental return-of-fear (ROF) induction through reinstatement (a model for adversity-induced relapse; day 2). Ratings, autonomic (skin conductance response) and neuronal activation measures (functional magnetic resonance imaging (fMRI)) were acquired. Individuals exposed to RA showed a generalized (that is, not CS- specific) fear recall and ROF, whereas unexposed individuals showed differential (that is, CS+ specific) fear recall and ROF on an autonomic level despite no group differences during fear acquisition and extinction learning. These group differences in ROF were accompanied by corresponding activation differences in brain areas known to be involved in fear processing and differentiability/generalization of ROF (that is, hippocampus). In addition, dimensional measures of RA, CA and lifetime adversity were negatively correlated with differential skin conductance responses (SCRs) during ROF and hippocampal activation. As discriminating signals of danger and safety, as well as a tendency for overgeneralization, are core features in clinically anxious populations, these deficits may specifically contribute to relapse risk following exposure to adversity, in particular to recent adversity. Hence, our results may provide first and novel insights into the possible mechanisms mediating enhanced relapse risk following exposure to (recent) adversity, which may guide the development of effective pre- and intervention programs. PMID:27434492

  7. Large-eddy simulation of flow over the Great Plains under stable atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Zhou, B.; Chow, F. K.

    2010-12-01

    The Great Plains in the central part of North America hosts enormous wind resources. One of the key meteorological features over the Great Plains is the frequent occurrence of nocturnal low-level jets under stably-stratified conditions. The flow speed up due to the formation of the low-level jets represents great wind power potential. In this study, large-eddy simulations (LES) will be performed over the site where the Cooperative Atmospheric-surface Exchange Study (CASES-99) field experiment took place. Atmospheric boundary layer (ABL) simulations driven by both strongly and weakly forced synoptic flows under stable atmospheric conditions will be investigated. While continuous turbulence is expected under strongly forced conditions, the weakly forced scenario is likely intermittent in nature, with occasional elevated turbulent bursts. The focus of this study includes vertical wind shear profiles, as well as turbulent statistics under stable conditions over the relatively flat, yet complex terrain. We will use an explicit filtering and reconstruction turbulence modeling LES approach. This approach has been proven advantageous in our previous work in terms of turbulence representation and agreement with similarity theory in neutral and stable atmospheric boundary layer flow over flat terrain. The dynamic reconstruction turbulence closure is capable of handling strong atmospheric stability, and predicting intermittent turbulence burst events in previous idealized simulations. This LES study ill provide detailed flow features under stable conditions over the Great Plains that can be valuable to the wind energy industry.

  8. Description of Atmospheric Conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

    SciTech Connect

    Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E.J.; Albuquerque, I.F.M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; /Mexico U., ICN /Santiago de Compostela U.

    2012-01-01

    Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown.

  9. Assessment Regarding Impact of Atmospheric Conditions on Space Shuttle Launch Delays

    NASA Technical Reports Server (NTRS)

    Johnson D. L.; Pearson, S. D.; Vaughan, W. W.; Batts, G. W.

    1998-01-01

    The atmospheric environment definition has played a key role in the development and operation of the NASA Space Shuttle as it has in other NASA Space Vehicle Programs. The objective of any definition of natural environment design requirements for a space vehicle development is to insure that the vehicle will perform safely and in a timely manner relative to the mission(s) for which the vehicle is being developed. The NASA Space Shuttle has enjoyed the longest tenure of any Space Vehicle from an operational standpoint. As such, it has provided a wealth of information on many engineering aspects of a Space Vehicle plus the influence of the atmosphere on operational endeavors. The atmospheric environment associated with the NASA Space Shuttle launches at the NASA Kennedy Space Center in Florida has been reviewed and studied over the entire NASA Space Shuttle flight history. The results of the analysis of atmospheric environment related launch delays relative to other sources of launch delays has been assessed. This paper will provide a summary of those conditions as well as mission analysis examples focused on atmospheric constraints for launch. Atmospheric conditions associated with NASA Space Shuttle launch delays will be presented to provide a reference as to the type conditions experienced which have mainly caused the delays.

  10. Relative Influence of Initial Surface and Atmospheric Conditions on Seasonal Water and Energy Balances

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Marshall, Susan; Roads, John O.; Robertson, Franklin R.; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    We constructed and analyzed wet and dry soil moisture composites for the mid-latitude GCIP region of the central US using long climate model simulations made with the NCAR CCM3 and reanalysis products from NCEP. Using the diagnostic composites as a guide, we have completed a series of predictability experiments in which we imposed soil water initial conditions in CCM3 for the GCIP region for June 1 from anomalously wet and dry years, with atmospheric initial conditions taken from June 1 of a year with 'near-normal' soil water, and initial soil water from the near-normal year and atmospheric initial conditions from the wet and dry years. Preliminary results indicate that the initial state of the atmosphere is more important than the initial state of soil water determining the subsequent late spring and summer evolution of sod water over the GCIP region. Surprisingly, neither the composites or the predictability experiments yielded a strong influence of soil moisture on the atmosphere. To explore this further, we have made runs with extreme dry soil moisture initial anomalies imposed over the GCIP region (the soil close to being completely dry). These runs did yield a very strong effect on the atmosphere that persisted for at least three months. We conclude that the magnitude of the initial soil moisture anomaly is crucial, at least in CCM3, and are currently investigating whether a threshold exists, below which little impact is seen. In a complementary study, we compared the impact of the initial condition of snow cover versus the initial atmospheric state over the western US (corresponding to the westward extension of the GAPP program follow-on to GCIP). In this case, the initial prescription of snow cover is far more important than the initial atmospheric state in determining the subsequent evolution of snow cover. We are currently working to understand the very different soil water and snow cover results.

  11. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1997-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements completed under this grant (NAGW-533), have shown that the opacity from, SO2 under simulated Venus conditions is best described by a different lineshape than was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  12. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1992-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. The goal of this investigation was to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  13. Investigating TIME-GCM Atmospheric Tides for Different Lower Boundary Conditions

    NASA Astrophysics Data System (ADS)

    Haeusler, K.; Hagan, M. E.; Lu, G.; Forbes, J. M.; Zhang, X.; Doornbos, E.

    2013-12-01

    It has been recently established that atmospheric tides generated in the lower atmosphere significantly influence the geospace environment. In order to extend our knowledge of the various coupling mechanisms between the different atmospheric layers, we rely on model simulations. Currently there exist two versions of the Global Scale Wave Model (GSWM), i.e. GSWM02 and GSWM09, which are used as a lower boundary (ca. 30 km) condition for the Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIME-GCM) and account for the upward propagating atmospheric tides that are generated in the troposphere and lower stratosphere. In this paper we explore the various TIME-GCM upper atmospheric tidal responses for different lower boundary conditions and compare the model diagnostics with tidal results from satellite missions such as TIMED, CHAMP, and GOCE. We also quantify the differences between results associated with GSWM02 and GSWM09 forcing and results of TIMEGCM simulations using Modern-Era Retrospective Analysis for Research and Application (MERRA) data as a lower boundary condition.

  14. Modified atmosphere packaging for fresh-cut ‘Kent’ mango under common retail display conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A modified atmosphere package (MAP) was designed to optimize the quality and shelf-life of fresh-cut ‘Kent’ mango during exposure to common retail display conditions. The synergism between the MAP system and an antioxidant treatment (calcium ascorbate and citric acid) was also investigated. Mango sl...

  15. Gas-phase degradation of the herbicide ethalfluralin under atmospheric conditions.

    PubMed

    Muñoz, Amalia; Vera, Teresa; Ródenas, Milagros; Borrás, Esther; Mellouki, Abdelwahid; Treacy, Jack; Sidebottom, Howard

    2014-01-01

    The gas-phase degradation of ethalfluralin, N-ethyl-α,α,α-trifluoro-N-(2-methylallyl)-2,6-dinitro-p-toluidine, a widely used herbicide, was investigated under atmospheric conditions at the large outdoor European simulation chamber (EUPHORE) in Valencia, Spain. The photolysis of ethalfluralin was investigated under solar radiation and the mean photolysis rate coefficient was determined: J(ethalfluralin)=(1.3±0.2)×10(-3) s(-1) (JNO2=8×10(-3) s(-1)). The rate coefficients for the reactions of hydroxyl radicals and ozone with ethalfluralin in the dark were also measured under atmospheric conditions using the relative rate and the absolute rate technique, respectively. The rate coefficients values for the reactions of kOH(ethalfluralin)=(3.5±0.9)×10(-11)cm(3)molecule(-1)s(-1), and kO3(ethalfluralin)=(1.6±0.4)×10(-17) cm(3) molecule(-1) s(-1) were determined at 300±5 K and atmospheric pressure. The results show that removal of ethalfluralin from the atmosphere by reactions with OH radicals (τ ~ 4 h) or ozone (τ ~ 25 h) is slow compared to loss by photolysis. The available kinetic data suggest that the gas-phase tropospheric degradation of ethalfluralin will be controlled mainly by photolysis and provide an estimate for the tropospheric lifetime of approximately 12 min. The atmospheric implications of using ethalfluralin as a herbicide are discussed. PMID:24139158

  16. Operational implications of a cloud model simulation of space shuttle exhaust clouds in different atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Zak, J. A.

    1989-01-01

    A three-dimensional cloud model was used to characterize the dominant influence of the environment on the Space Shuttle exhaust cloud. The model was modified to accept the actual heat and moisture from rocket exhausts and deluge water as initial conditions. An upper-air sounding determined the ambient atmosphere in which the cloud would grow. The model was validated by comparing simulated clouds with observed clouds from four actual Shuttle launches. Results are discussed with operational weather forecasters in mind. The model successfully produced clouds with dimensions, rise, decay, liquid water contents, and vertical motion fields very similar to observed clouds whose dimensions were calculated from 16 mm film frames. Once validated, the model was used in a number of different atmospheric conditions ranging from very unstable to very stable. Wind shear strongly affected the appearance of both the ground cloud and vertical column cloud. The ambient low-level atmospheric moisture governed the amount of cloud water in model clouds. Some dry atmospheres produced little or no cloud water. An empirical forecast technique for Shuttle cloud rise is presented and differences between natural atmospheric convection and exhaust clouds are discussed.

  17. Laboratory Evaluation and Application of Microwave Absorption Properties under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    2002-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based or spacecraft-based radio astronomical (emission) observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or the use of laboratory measurements of such properties taken under environmental conditions that are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements have shown that the centimeter-wavelength opacity from gaseous phosphine (PH3) under simulated conditions for the outer planets far exceeds that predicted from theory over a wide range of temperatures and pressures. This fundamentally changed the resulting interpretation of Voyager radio occultation data at Saturn and Neptune. It also directly impacts planning and scientific goals for study of Saturn's atmosphere with the Cassini Radio Science Experiment and the Rossini RADAR instrument. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both spacecraft entry probe and orbiter (or flyby) radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations

  18. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1992-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements performed by Fahd and Steffes have shown that the opacity from gaseous SO2 under simulated Venus conditions can be well described by the Van Vleck-Weisskopf lineshape at wavelengths shortward of 2 cm, but that the opacity of wavelengths greater than 2 cm is best described by a different lineshape that was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  19. A cloud model simulation of space shuttle exhaust clouds in different atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Chen, C.; Zak, J. A.

    1989-01-01

    A three-dimensional cloud model was used to characterize the dominant influence of the environment on the Space Shuttle exhaust cloud. The model was modified to accept the actual heat and moisture from rocket exhausts and deluge water as initial conditions. An upper-air sounding determined the ambient atmosphere in which the cloud could grow. The model was validated by comparing simulated clouds with observed clouds from four actual Shuttle launches. The model successfully produced clouds with dimensions, rise, decay, liquid water contents and vertical motion fields very similar to observed clouds whose dimensions were calculated from 16 mm film frames. Once validated, the model was used in a number of different atmospheric conditions ranging from very unstable to very stable. In moist, unstable atmospheres simulated clouds rose to about 3.5 km in the first 4 to 8 minutes then decayed. Liquid water contents ranged from 0.3 to 1.0 g kg-1 mixing ratios and vertical motions were from 2 to 10 ms-1. An inversion served both to reduce entrainment (and erosion) at the top and to prevent continued cloud rise. Even in the most unstable atmospheres, the ground cloud did not rise beyond 4 km and in stable atmospheres with strong low level inversions the cloud could be trapped below 500 m. Wind shear strongly affected the appearance of both the ground cloud and vertical column cloud. The ambient low-level atmospheric moisture governed the amount of cloud water in model clouds. Some dry atmospheres produced little or no cloud water. One case of a simulated TITAN rocket explosion is also discussed.

  20. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today. PMID:26573709

  1. Antagonistic Pleiotropy at the Human IL6 Promoter Confers Genetic Resilience to the Pro-Inflammatory Effects of Adverse Social Conditions in Adolescence

    PubMed Central

    Cole, Steven W.; Arevalo, Jesusa M. G.; Manu, Kavya; Telzer, Eva H.; Kiang, Lisa; Bower, Julienne E.; Irwin, Michael R.; Fuligni, Andrew J.

    2013-01-01

    The authors tested the evolutionary genetic hypothesis that the functional form of an asymmetrically risky Gene × Environment interaction will differ as a function of age-related antagonistic pleiotropy (i.e., show opposite effects in young vs. old individuals). Previous studies have identified a polymorphism in the human IL6 promoter (rs1800795; IL6 –174 G/C) that interacts with adverse socioenvironmental conditions to promote chronic inflammation in older adults (elevated C-reactive protein). This study identifies a protective effect of the same polymorphism in 17- to 19-year-old adolescents confronting socioeconomic adversity. Over 60% of the environmental risk contribution to the IL6 × Socioeconomic Status interaction could be accounted for by interpersonal stress and adult role burden. Thus, the IL6 –174G allele does not represent an undifferentiated risk factor but instead sensitizes inflammatory biology to socioenvironmental conditions, conferring either genetic vulnerability or resilience depending on the developmental “somatic environment” that interacts with social conditions to influence gene expression. PMID:21639625

  2. Investigating Atmospheric Effects on Impact Ejecta Morphology: Possible Tool for Determining Past Climate Conditions on Mars?

    NASA Technical Reports Server (NTRS)

    Appleby, John F.; Barnouin-Jha, Oliver S.; Cheng, Andrew F.

    1999-01-01

    The combined use of impact crater morphology and mechanics provides important information on the physical conditions of both planetary atmospheres and planetary and asteroid surfaces present during crater formation, while an understanding of the rate of crater production on the surface of asteroids provides information of their surface and spin rate evolution. The research performed with support from this project improves our understanding of (1) the mechanics of impact cratering in order to gain insights on the evolution of these physical surface conditions on planets with atmospheres and asteroids, and (2) how impact flux across an asteroid surface may vary due to anisotropic distribution of impactors in the solar system. As part of this project, we have undertaken three studies. In the first study, we investigate atmospheric effects on the morphology of ejecta excavated during a cratering event in order to determine the atmospheric and target conditions from observed crater morphologies. In the second study, we use the physical and morphological consequences of oblique impacts on an asteroid to understand how the asteroid Mathilde (recently imaged by the Near Earth Asteroid Rendezvous - NEAR- spacecraft) could have survived the formation of five giant craters. In a third study, we use a Monte Carlo method to calculate the impact flux on an asteroid given a distribution of impactors on elliptical orbits. In the following section, we present the result obtained from all three studies.

  3. Interaction between Late Holocene bottom water conditions in Skagerrak and Kattegat and predominant atmospheric forcing

    NASA Astrophysics Data System (ADS)

    Risebrobakken, B.; Kabel, K.; Jentzen, A.; Moros, M.; Jansen, E.

    2011-12-01

    The brackish and anoxic Baltic Sea is episodically ventilated when major inflow of Atlantic water occurs, Atlantic water that enters the Baltic Sea through Skagerrak and Kattegat. Periods with a stronger flux of Atlantic water increases the bottom water temperatures in Skagerrak, and temperatures and salinities in Kattegat. A tight connection between the major inflow events and the predominant atmospheric forcing over the North Atlantic and Nordic Seas are suggested in literature. How the atmospheric forcing and the inflow events are mechanistically connected is however discussed. To detect how periods of stronger inflow of Atlantic water through Skagerrak and Kattegat are related to the predominant atmospheric forcing at longer time scales, we investigate new high-resolution stable isotope, Mg/Ca and foraminiferal assemblage records documenting bottom water conditions in Skagerrak and Kattegat since approximately 1700 AD. Close to annual resolution through the last 30 years enables validation of our reconstructions towards local instrumental records of bottom water conditions and documented changes in atmospheric forcing. High-resolution stable isotope records covering the last 4000 years supplements the 300-year long records so that changes in climatic conditions in the Skagerrak/Kattegat area at longer time-scales through late Holocene are detected and the dynamical forcing behind these climatic changes investigated.

  4. Launch Condition Deviations of Reusable Launch Vehicle Simulations in Exo-Atmospheric Zoom Climbs

    NASA Technical Reports Server (NTRS)

    Urschel, Peter H.; Cox, Timothy H.

    2003-01-01

    The Defense Advanced Research Projects Agency has proposed a two-stage system to deliver a small payload to orbit. The proposal calls for an airplane to perform an exo-atmospheric zoom climb maneuver, from which a second-stage rocket is launched carrying the payload into orbit. The NASA Dryden Flight Research Center has conducted an in-house generic simulation study to determine how accurately a human-piloted airplane can deliver a second-stage rocket to a desired exo-atmospheric launch condition. A high-performance, fighter-type, fixed-base, real-time, pilot-in-the-loop airplane simulation has been modified to perform exo-atmospheric zoom climb maneuvers. Four research pilots tracked a reference trajectory in the presence of winds, initial offsets, and degraded engine thrust to a second-stage launch condition. These launch conditions have been compared to the reference launch condition to characterize the expected deviation. At each launch condition, a speed change was applied to the second-stage rocket to insert the payload onto a transfer orbit to the desired operational orbit. The most sensitive of the test cases was the degraded thrust case, yielding second-stage launch energies that were too low to achieve the radius of the desired operational orbit. The handling qualities of the airplane, as a first-stage vehicle, have also been investigated.

  5. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1987-01-01

    Laboratory measurements were conducted to evaluate properties of atmospheric gases under simulated conditions for the outer planets. A significant addition to this effort was the capability to make such measurements at millimeter wavelengths. Measurements should soon be completed on the millimeter wave absorption from ammonia under Jovian conditions. Also studied will be the feasibility of measuring the microwave and millimeter wave properties of phosphine (PH3) under simulated Jovian conditions. Further analysis and application of the laboratory results to microwave and millimeter wave absorption data for the outer planet, such as Voyager Radio Occultation experiments, will be pursued.

  6. Ultraviolet light propagation under low visibility atmospheric conditions and its application to aircraft landing aid.

    PubMed

    Lavigne, Claire; Durand, Gérard; Roblin, Antoine

    2006-12-20

    Light scattering in the atmosphere by particles and molecules gives rise to an aureole surrounding the source image that tends to reduce the contrast of the source with respect to the background. However, UV scattering phase functions of the haze droplets present a very important forward peak. The spreading of a detected signal in the UV is not as important as in the case of a clear atmosphere where Rayleigh scattering predominates. This physical property has to be taken into account to evaluate the potential of UV radiation as an aircraft landing aid under low visibility conditions. Different results characterizing UV runway lights, simulations of UV radiation propagation in the atmosphere, and the use of a simple detection algorithm applied to one particular sensor are presented. PMID:17151753

  7. Influences of atmospheric conditions and air mass on the ratio of ultraviolet to total solar radiation

    SciTech Connect

    Riordan, C.J.; Hulstrom, R.L.; Myers, D.R.

    1990-08-01

    The technology to detoxify hazardous wastes using ultraviolet (UV) solar radiation is being investigated by the DOE/SERI Solar Thermal Technology Program. One of the elements of the technology evaluation is the assessment and characterization of UV solar radiation resources available for detoxification processes. This report describes the major atmospheric variables that determine the amount of UV solar radiation at the earth's surface, and how the ratio of UV-to-total solar radiation varies with atmospheric conditions. These ratios are calculated from broadband and spectral solar radiation measurements acquired at SERI, and obtained from the literature on modeled and measured UV solar radiation. The following sections discuss the atmospheric effects on UV solar radiation and provide UV-to-total solar radiation ratios from published studies, as well as measured values from SERI's data. A summary and conclusions are also given.

  8. Characteristics of energetic electron precipitation into the earth's polar atmosphere and geomagnetic conditions

    NASA Astrophysics Data System (ADS)

    Makhmutov, V. S.; Bazilevskaya, G. A.; Krainev, M. B.

    A number of energetic electron precipitation events (EPEs) were observed in the Earth's polar atmosphere (Murmansk region, geographical coordinates 68.57 N, 33.03 E and Mirny, Antarctica, 66.34 S, 92.55 E) during the long-term cosmic ray balloon experiment from 1957 up to now. During geomagnetic storms significant X-ray fluxes caused by precipitating electrons at the top of the atmosphere sometimes penetrated to the atmospheric depth of 60 gcm-2. We show that (1) there is a quasi-11-year cycle in EPE occurrence shifted with respect to solar activity cycle, and (2) the yearly rate of EPE occurrence has an ascending trend during the period 1965-1999. The EPE characteristics evaluated from the balloon experiment are compared with the available data on geomagnetic activity and the possible relations between the features of EPE events and geomagnetic conditions are discussed.

  9. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1998-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties taken under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements completed recently by Kolodner and Steffes (ICARUS 132, pp. 151-169, March 1998, attached as Appendix A) under this grant (NAGS-4190), have shown that the opacity from gaseous H2SO4 under simulated Venus conditions is best described by a different formalism than was previously used. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both spacecraft entry probe and orbiter radio occultation experiments and by radio astronomical observations, and over a range of frequencies which correspond to those used in such experiments, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  10. Comparison of Dynamic Characteristics for an Inflatable Solar Concentrator in Atmospheric and Thermal Vacuum Conditions

    NASA Technical Reports Server (NTRS)

    Slade, Kara N.; Tinker, Michael L.; Lassiter, John O.; Engberg, Robert

    2000-01-01

    Dynamic testing of an inflatable solar concentrator structure in a thermal vacuum chamber as well as in ambient laboratory conditions is described in detail. Unique aspects of modal testing for the extremely lightweight inflatable are identified, including the use of a noncontacting laser vibrometer measurement system. For the thermal vacuum environment, mode shapes and frequency response functions are compared for three different test article inflation pressures at room temperature. Modes that persist through all the inflation pressure regimes are identified, as well as modes that are unique for each pressure. In atmospheric pressure and room temperature conditions, dynamic measurements were obtained for the expected operational inflation pressure of 0.5 psig. Experimental mode shapes and frequency response functions for ambient conditions are described and compared to the 0.5 psig results from the thermal vacuum tests. Only a few mode shapes were identified that occurred in both vacuum and atmospheric environments. This somewhat surprising result is discussed in detail, and attributed at least partly to 1.) large differences in modal damping, and 2.) significant differences in the mass of air contained by the structure, in the two environments. Results of this investigation point out the necessity of testing inflatable space structures in vacuum conditions before they can be launched. Ground testing in atmospheric pressure is not sufficient for predicting on-orbit dynamics of non-rigidized inflatable systems.

  11. Recreation of Marine Atmospheric Corrosion Condition on Weathering Steel in Laboratory

    NASA Astrophysics Data System (ADS)

    Guchhait, S. K.; Dewan, S.; Saha, J. K.; Mitra, P. K.

    2014-04-01

    Salt spray test, autoclave corrosion test, SO2 salt spray test, and Relative humidity test are generally used to assess atmospheric corrosion in laboratories at accelerated rates. However, no test can absolutely simulate the service condition. One can get only approximate corrosion rates using the aforesaid tests which serve as an indicative of corrosion behavior of the material in a service condition. The present work is aimed at creating specific environmental condition in laboratory to get the corrosion test done in short duration to compare with on field exposure test which would otherwise take years to complete. In this work recreation of atmospheric environment of Digha was tried and it was simulated in such a manner that the results of laboratory test could be compared with long time field exposure at Digha. Weathering steel (WS) was taken for experimentations. Potentiostatic electrochemical tests route was adopted to simulate atmospheric condition of Digha. Laboratory test results compared well with 18 month field exposure data in terms of corrosion rate, SEM and Ramon Spectroscopy matching.

  12. Evidence for the role of organics in aerosol particle formation under atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Baltensperger, Urs

    2010-05-01

    New particle formation in the atmosphere is an important parameter in governing the radiative forcing of atmospheric aerosols. However, detailed nucleation mechanisms remain still ambiguous, as laboratory data have so far not been successful in explaining atmospheric nucleation. We investigated the formation of new particles in a smog chamber simulating the photochemical formation of H2SO4 and organic condensable species. Nucleation occurs at H2SO4 concentrations similar to the ones found in the ambient atmosphere during nucleation events. The measured particle formation rates are proportional to the product of the concentrations of H2SO4 and an organic molecule. This suggests that only one H2SO4 molecule and one organic molecule are involved in the rate limiting step of the observed nucleation process. Parameterizing this process in a global aerosol model results in substantially better agreement with ambient observations compared to control runs. Reference: Axel Metzger, Bart Verheggen, Josef Dommen, Jonathan Duplissy, Andre S. H. Prevot, Ernest Weingartner, Ilona Riipinen, Markku Kulmala, Dominick V. Spracklen, Kenneth S. Carslaw, and Urs Baltensperger, Evidence for the role of organics in aerosol particle formation under atmospheric conditions, Proc. Natl. Acad. Sci. USA, 107 (2010), www.pnas.org/cgi/doi/10.1073/pnas.0911330107.

  13. Effects of Clouds on Cross-Atmospheric Radiative Flux Divergence: Case Studies in Different Cloud Conditions

    NASA Astrophysics Data System (ADS)

    Ghate, V. P.; Miller, M. A.

    2013-12-01

    Clouds have a profound effect on the amount of radiation absorbed across the atmospheric column. The amount of absorption mainly depends on the location and type of the clouds, the albedo of the surface and profile of water vapor mixing ratio in the atmospheric column. In this study we have used the data collected during the deployment of Atmospheric Radiation Measurement (ARM)'s first Mobile Facility (AMF#1) at the island of Graciosa in the North Atlantic and at the Niamey, Niger to assess the impact of different cloud types on the cross-atmospheric radiative flux divergence. The cloud structure was retrieved using the data collected by a vertically pointing w-band cloud radar, a micro-pulse lidar, laser ceilometer among other instruments. The profiles of temperature, moisture and winds were measured by balloon borne radiosondes. The radiation at the surface were measured by broadband radiometers, while the radiation at the top of the atmosphere were measured by the Geostationary Earth Radiation Budget (GERB) radiometers onboard the Meteosat Second Generation (MSG) satellite. Simulations of a 1-dimensional radiative transfer model called as Rapid Radiative Transfer Model (RRTM) having representation of cloud and aerosol properties are made to assess the relative impact of different cloud types and water vapor on spectral bands both in the shortwave and longwave radiation spectrum. Results from four case-studies which had cloud free conditions, single layered stratocumulus clouds, broken shallow cumulus clouds and high level cirrus clouds respectively will be presented.

  14. Foliar photochemical processes and carbon metabolism under favourable and adverse winter conditions in a Mediterranean mixed forest, Catalonia (Spain)

    NASA Astrophysics Data System (ADS)

    Sperlich, D.; Chang, C. T.; Peñuelas, J.; Gracia, C.; Sabaté, S.

    2014-06-01

    Evergreen trees in the Mediterranean region must cope with a wide range of environmental stresses from summer drought to winter cold. The mildness of Mediterranean winters can periodically lead to favourable environmental conditions above the threshold for a positive carbon balance, benefitting evergreen woody species more than deciduous ones. The comparatively lower solar energy input in winter decreases the foliar light saturation point. This leads to a higher susceptibility to photoinhibitory stress especially when chilly (< 12 °C) or freezing temperatures (< 0 °C) coincide with clear skies and relatively high solar irradiances. Nonetheless, the advantage of evergreen species that are able to photosynthesize all year round where a significant fraction can be attributed to winter months, compensates for the lower carbon uptake during spring and summer in comparison to deciduous species. We investigated the ecophysiological behaviour of three co-occurring mature evergreen tree species (Quercus ilex L., Pinus halepensis Mill., and Arbutus unedo L.) during a period of mild winter conditions and their responses to a sudden cold period. The state of the photosynthetic machinery in both periods was thus tested by estimating the foliar photosynthetic potential with CO2 response curves in parallel with chlorophyll fluorescence measurements. The studied evergreen tree species benefited strongly from mild winter conditions by exhibiting extraordinarily high photosynthetic potentials similar to those under spring conditions. A sudden period of frost, however, negatively affected the photosynthetic apparatus, leading to significant decreases in key physiological parameters such as the maximum carboxylation velocity (Vc, max), the maximum photosynthetic electron transport rate (Jmax), and the optimal fluorometric quantum yield of photosystem II (Fv/Fm). This change persisted for several weeks after the cold period despite the recovery of the temperature to the conditions

  15. Synoptic conditions related to soil moisture-atmosphere interactions and unorganized convection in Oklahoma

    NASA Astrophysics Data System (ADS)

    Ford, Trent W.; Quiring, Steven M.; Frauenfeld, Oliver W.; Rapp, Anita D.

    2015-11-01

    Atmospheric modification by anomalously dry or wet soils can both enhance and suppress convective activity. However, the local-scale and mesoscale feedback governing soil moisture-precipitation coupling are embedded within the larger synoptic-scale environment. Despite their importance, synoptic-scale atmospheric conditions are rarely considered in studies examining soil moisture-atmosphere interactions. We combine self-organizing maps of 500 hPa geopotential height, spatial synoptic classification, and Hybrid Single-Particle Lagrangian Integrated Trajectory model air mass trajectories to determine if the synoptic-scale environment affects the ability of the land surface to force unorganized convection in Oklahoma. We identify several synoptic patterns that significantly impact the frequency of unorganized convection. Synoptic patterns characterized by midlevel troughs over the Southern Great Plains are less frequently associated with unorganized convective events. These patterns exhibit cool air advection in the midlevel and lower level of the atmosphere and are linked to suppression of convective activity. The synoptic patterns characterized by 500 hPa ridging over the study region are more frequently associated with unorganized convective events. These patterns likely result in increased net radiation, vapor pressure deficit, and more homogenously dry soils. Unorganized convective events that occur during these synoptic conditions initiate preferentially over dry soils. We present evidence that the synoptic-scale environment can influence whether and how the land surface has an impact on convection.

  16. Foliar photochemical processes and carbon metabolism under favourable and adverse winter conditions in a Mediterranean mixed forest, Catalonia (Spain)

    NASA Astrophysics Data System (ADS)

    Sperlich, D.; Chang, C. T.; Peñuelas, J.; Gracia, C.; Sabaté, S.

    2014-10-01

    Evergreen trees in the Mediterranean region must cope with a wide range of environmental stresses from summer drought to winter cold. The mildness of Mediterranean winters can periodically lead to favourable environmental conditions above the threshold for a positive carbon balance, benefitting evergreen woody species more than deciduous ones. The comparatively lower solar energy input in winter decreases the foliar light saturation point. This leads to a higher susceptibility to photoinhibitory stress especially when chilly (< 12 °C) or freezing temperatures (< 0 °C) coincide with clear skies and relatively high solar irradiances. Nonetheless, the advantage of evergreen species that are able to photosynthesize all year round where a significant fraction can be attributed to winter months, compensates for the lower carbon uptake during spring and summer in comparison to deciduous species. We investigated the ecophysiological behaviour of three co-occurring mature evergreen tree species (Quercus ilex L., Pinus halepensis Mill., and Arbutus unedo L.). Therefore, we collected twigs from the field during a period of mild winter conditions and after a sudden cold period. After both periods, the state of the photosynthetic machinery was tested in the laboratory by estimating the foliar photosynthetic potential with CO2 response curves in parallel with chlorophyll fluorescence measurements. The studied evergreen tree species benefited strongly from mild winter conditions by exhibiting extraordinarily high photosynthetic potentials. A sudden period of frost, however, negatively affected the photosynthetic apparatus, leading to significant decreases in key physiological parameters such as the maximum carboxylation velocity (Vc, max), the maximum photosynthetic electron transport rate (Jmax), and the optimal fluorometric quantum yield of photosystem II (Fv/Fm). The responses of Vc, max and Jmax were highly species specific, with Q. ilex exhibiting the highest and P

  17. Modeling the effect of adverse environmental conditions and clothing on temperature rise in a human body exposed to radio frequency electromagnetic fields.

    PubMed

    Moore, Stephen M; McIntosh, Robert L; Iskra, Steve; Wood, Andrew W

    2015-02-01

    This study considers the computationally determined thermal profile of a fully clothed, finely discretized, heterogeneous human body model, subject to the maximum allowable reference level for a 1-GHz radio frequency electromagnetic field for a worker, and also subject to adverse environmental conditions, including high humidity and high ambient temperature. An initial observation is that while electromagnetic fields at the occupational safety limit will contribute an additional thermal load to the tissues, and subsequently, cause an elevated temperature, the magnitude of this effect is far outweighed by that due to the conditions including the ambient temperature, relative humidity, and the type of clothing worn. It is envisaged that the computational modeling approach outlined in this paper will be suitably modified in future studies to evaluate the thermal response of a body at elevated metabolic rates, and for different body shapes and sizes including children and pregnant women. PMID:25314694

  18. Aerosol physical, chemical and optical properties observed in the ambient atmosphere during haze pollution conditions

    NASA Astrophysics Data System (ADS)

    Li, Zhengqiang; Xie, Yisong; Li, Donghui; Li, Kaitao; Zhang, Ying; Li, Li; Lv, Yang; Qie, Lili; Xu, Hua

    Aerosol’s properties in the ambient atmosphere may differ significantly from sampling results due to containing of abundant water content. We performed sun-sky radiometer measurements in Beijing during 2011 and 2012 winter to obtain distribution of spectral and angular sky radiance. The measurements are then used to retrieve aerosol physical, chemical and optical properties, including single scattering albedo, size distribution, complex refractive indices and aerosol component fractions identified as black carbon, brown carbon, mineral dust, ammonium sulfate-like components and water content inside particle matters. We found that during winter haze condition aerosol is dominated by fine particles with center radius of about 0.2 micron. Fine particles contribute about 93% to total aerosol extinction of solar light, and result in serious decrease of atmospheric visibility during haze condition. The percentage of light absorption of haze aerosol can up to about 10% among its total extinction, much higher than that of unpolluted conditions, that causes significant radiative cooling effects suppressing atmospheric convection and dispersion of pollutants. Moreover, the average water content occupies about one third of the ambient aerosol in volume which suggests the important effect of ambient humidity in the formation of haze pollution.

  19. Solar Wind Interaction with the Martian Upper Atmosphere at Early Mars/Extreme Solar Conditions

    NASA Astrophysics Data System (ADS)

    Dong, C.; Bougher, S. W.; Ma, Y.; Toth, G.; Lee, Y.; Nagy, A. F.; Tenishev, V.; Pawlowski, D. J.; Combi, M. R.

    2014-12-01

    The investigation of ion escape fluxes from Mars, resulting from the solar wind interaction with its upper atmosphere/ionosphere, is important due to its potential impact on the long-term evolution of Mars atmosphere (e.g., loss of water) over its history. In the present work, we adopt the 3-D Mars cold neutral atmosphere profiles (0 ~ 300 km) from the newly developed and validated Mars Global Ionosphere Thermosphere Model (M-GITM) and the 3-D hot oxygen profiles (100 km ~ 5 RM) from the exosphere Monte Carlo model Adaptive Mesh Particle Simulator (AMPS). We apply these 3-D model output fields into the 3-D BATS-R-US Mars multi-fluid MHD (MF-MHD) model (100 km ~ 20 RM) that can simulate the interplay between Mars upper atmosphere and solar wind by considering the dynamics of individual ion species. The multi-fluid MHD model solves separate continuity, momentum and energy equations for each ion species (H+, O+, O2+, CO2+). The M-GITM model together with the AMPS exosphere model take into account the effects of solar cycle and seasonal variations on both cold and hot neutral atmospheres. This feature allows us to investigate the corresponding effects on the Mars upper atmosphere ion escape by using a one-way coupling approach, i.e., both the M-GITM and AMPS model output fields are used as the input for the multi-fluid MHD model and the M-GITM is used as input into the AMPS exosphere model. In this study, we present M-GITM, AMPS, and MF-MHD calculations (1-way coupled) for 2.5 GYA conditions and/or extreme solar conditions for present day Mars (high solar wind velocities, high solar wind dynamic pressure, and high solar irradiance conditions, etc.). Present day extreme conditions may result in MF-MHD outputs that are similar to 2.5 GYA cases. The crustal field orientations are also considered in this study. By comparing estimates of past ion escape rates with the current ion loss rates to be returned by the MAVEN spacecraft (2013-2016), we can better constrain the

  20. Circulation within the primary system at TMI-2 with lowered coolant level and at atmospheric conditions

    SciTech Connect

    Baston, V.F.; Hofstetter, K.J.; Malinauskas, A.P.

    1985-06-01

    Experiments were performed with the Three Mile Island reactor coolant system open to the atmosphere and the coolant lowered to a level above the fuel (a condition required for defueling) to ascertain the extent of coolant mixing. A principal concern for coolant decontamination during defueling is the radionuclides released and their distribution within the primary system. Analyses of radionuclide, temperature, and dissolved oxygen data taken during these experiments confirm mixing in the primary system under forced coolant flow conditions with only minimal mixing occurring during static periods.

  1. Precipitation-climate sensitivity to initial conditions in an atmospheric general circulation model

    SciTech Connect

    Covey, C., LLNL

    1997-03-01

    Atmospheric climate, in contrast to weather, is traditionally considered to be determined by boundary conditions such as sea surface temperature (SST). To test this hypothesis, we examined annual mean precipitation from an ensemble of 20 general circulation model (GCM) simulations. Ensemble members were forced with identical 10-year series of SST and sea ice, but they began with slightly differing initial conditions. A surprisingly small proportion of the variance in the output is attributable to the effects of boundary forcing. This result-and similar evidence from smaller ensembles of other GCM simulations-implies that long-term precipitation variations are mostly unpredictable, even if SST forecasts are `perfect.`

  2. IONIZATION IN ATMOSPHERES OF BROWN DWARFS AND EXTRASOLAR PLANETS. III. BREAKDOWN CONDITIONS FOR MINERAL CLOUDS

    SciTech Connect

    Helling, Ch.; Jardine, M.; Stark, C.; Diver, D.

    2013-04-20

    Electric discharges were detected directly in the cloudy atmospheres of Earth, Jupiter, and Saturn, are debatable for Venus, and indirectly inferred for Neptune and Uranus in our solar system. Sprites (and other types of transient luminous events) have been detected only on Earth, and are theoretically predicted for Jupiter, Saturn, and Venus. Cloud formation is a common phenomenon in ultra-cool atmospheres such as in brown dwarf and extrasolar planetary atmospheres. Cloud particles can be expected to carry considerable charges which may trigger discharge events via small-scale processes between individual cloud particles (intra-cloud discharges) or large-scale processes between clouds (inter-cloud discharges). We investigate electrostatic breakdown characteristics, like critical field strengths and critical charge densities per surface, to demonstrate under which conditions mineral clouds undergo electric discharge events which may trigger or be responsible for sporadic X-ray emission. We apply results from our kinetic dust cloud formation model that is part of the DRIFT-PHOENIX model atmosphere simulations. We present a first investigation of the dependence of the breakdown conditions in brown dwarf and giant gas exoplanets on the local gas-phase chemistry, the effective temperature, and primordial gas-phase metallicity. Our results suggest that different intra-cloud discharge processes dominate at different heights inside mineral clouds: local coronal (point discharges) and small-scale sparks at the bottom region of the cloud where the gas density is high, and flow discharges and large-scale sparks near, and maybe above, the cloud top. The comparison of the thermal degree of ionization and the number density of cloud particles allows us to suggest the efficiency with which discharges will occur in planetary atmospheres.

  3. One-against-All Weighted Dynamic Time Warping for Language-Independent and Speaker-Dependent Speech Recognition in Adverse Conditions

    PubMed Central

    Zhang, Xianglilan; Sun, Jiping; Luo, Zhigang

    2014-01-01

    Considering personal privacy and difficulty of obtaining training material for many seldom used English words and (often non-English) names, language-independent (LI) with lightweight speaker-dependent (SD) automatic speech recognition (ASR) is a promising option to solve the problem. The dynamic time warping (DTW) algorithm is the state-of-the-art algorithm for small foot-print SD ASR applications with limited storage space and small vocabulary, such as voice dialing on mobile devices, menu-driven recognition, and voice control on vehicles and robotics. Even though we have successfully developed two fast and accurate DTW variations for clean speech data, speech recognition for adverse conditions is still a big challenge. In order to improve recognition accuracy in noisy environment and bad recording conditions such as too high or low volume, we introduce a novel one-against-all weighted DTW (OAWDTW). This method defines a one-against-all index (OAI) for each time frame of training data and applies the OAIs to the core DTW process. Given two speech signals, OAWDTW tunes their final alignment score by using OAI in the DTW process. Our method achieves better accuracies than DTW and merge-weighted DTW (MWDTW), as 6.97% relative reduction of error rate (RRER) compared with DTW and 15.91% RRER compared with MWDTW are observed in our extensive experiments on one representative SD dataset of four speakers' recordings. To the best of our knowledge, OAWDTW approach is the first weighted DTW specially designed for speech data in adverse conditions. PMID:24520317

  4. One-against-all weighted dynamic time warping for language-independent and speaker-dependent speech recognition in adverse conditions.

    PubMed

    Zhang, Xianglilan; Sun, Jiping; Luo, Zhigang

    2014-01-01

    Considering personal privacy and difficulty of obtaining training material for many seldom used English words and (often non-English) names, language-independent (LI) with lightweight speaker-dependent (SD) automatic speech recognition (ASR) is a promising option to solve the problem. The dynamic time warping (DTW) algorithm is the state-of-the-art algorithm for small foot-print SD ASR applications with limited storage space and small vocabulary, such as voice dialing on mobile devices, menu-driven recognition, and voice control on vehicles and robotics. Even though we have successfully developed two fast and accurate DTW variations for clean speech data, speech recognition for adverse conditions is still a big challenge. In order to improve recognition accuracy in noisy environment and bad recording conditions such as too high or low volume, we introduce a novel one-against-all weighted DTW (OAWDTW). This method defines a one-against-all index (OAI) for each time frame of training data and applies the OAIs to the core DTW process. Given two speech signals, OAWDTW tunes their final alignment score by using OAI in the DTW process. Our method achieves better accuracies than DTW and merge-weighted DTW (MWDTW), as 6.97% relative reduction of error rate (RRER) compared with DTW and 15.91% RRER compared with MWDTW are observed in our extensive experiments on one representative SD dataset of four speakers' recordings. To the best of our knowledge, OAWDTW approach is the first weighted DTW specially designed for speech data in adverse conditions. PMID:24520317

  5. Influence of Surface Seawater and Atmospheric Conditions on the Ccn Activity of Ocean-Derived Aerosol

    NASA Astrophysics Data System (ADS)

    Quinn, P.; Bates, T. S.; Russell, L. M.; Frossard, A. A.; Keene, W. C.; Kieber, D. J.; Hakala, J. P.

    2012-12-01

    Ocean-derived aerosols are produced from direct injection into the atmosphere (primary production) and gas-to-particle conversion in the atmosphere (secondary production). These different production mechanisms result in a broad range of particle sizes that has implications for the impact of ocean-derived aerosol on climate. The chemical composition of ocean-derived aerosols is a result of a complex mixture of inorganic sea salt and organic matter including polysaccharides, proteins, amino acids, microorganisms and their fragments, and secondary oxidation products. Both production mechanisms and biological processes in the surface ocean impact the ability of ocean-derived aerosol to act as cloud condensation nuclei (CCN). In addition, CCN activity can be impacted by atmospheric processing that modifies particle size and composition after the aerosol is emitted from the ocean. To understand relationships between production mechanism, surface ocean biology, and atmospheric processing, measurements were made of surface ocean chlorophyll and dissolved organic matter; nascent sea spray aerosol freshly emitted from the ocean surface; and ambient marine aerosol. These measurements were made along the coast of California and in the North Atlantic between the northeast US and Bermuda. These regions include both eutrophic and oligotraphic waters and, thus, provide for observations over a wide range of ocean conditions.

  6. Increased greenhouse-gas intensity of rice production under future atmospheric conditions

    NASA Astrophysics Data System (ADS)

    van Groenigen, Kees Jan; van Kessel, Chris; Hungate, Bruce A.

    2013-03-01

    Increased atmospheric CO2 and rising temperatures are expected to affect rice yields and greenhouse-gas (GHG) emissions from rice paddies. This is important, because rice cultivation is one of the largest human-induced sources of the potent GHG methane (CH4) and rice is the world's second-most produced staple crop. The need for meeting a growing global food demand argues for assessing GHG emissions from croplands on the basis of yield rather than land area, such that efforts to reduce GHG emissions take into consideration the consequences for food production. However, it is unclear whether or how the GHG intensity (that is, yield-scaled GHG emissions) of cropping systems will be affected by future atmospheric conditions. Here we show, using meta-analysis, that increased atmospheric CO2 (ranging from 550 to 743ppmV) and warming (ranging from +0.8°C to +6°C) both increase the GHG intensity of rice cultivation. Increased atmospheric CO2 increased GHG intensity by 31.4%, because CH4 emissions are stimulated more than rice yields. Warming increased GHG intensity by 11.8% per 1°C, largely owing to a decrease in yield. This analysis suggests that rising CO2 and warming will approximately double the GHG intensity of rice production by the end of the twenty-first century, stressing the need for management practices that optimize rice production while reducing its GHG intensity as the climate continues to change.

  7. Storage of milk powders under adverse conditions. 2. Influence on the content of water-soluble vitamins.

    PubMed

    Ford, J E; Hurrell, R F; Finot, P A

    1983-05-01

    Storage of milk powder under unfavourable conditions accelerates the normally slow deterioration in nutritional quality. The effects of such storage on the water-soluble vitamin composition were examined. (a) Spray-dried whole milk containing 25 g water/kg was stored at 60 degrees and 70 degrees and sampled weekly to 9 weeks. (b) Spray-dried whole milk and skimmed milk were adjusted to contain 40 and 100 g water/kg and stored at 37 degrees in nitrogen and in oxygen. Samples were taken for analysis at intervals during storage. The samples were analysed for eight B-complex vitamins and ascorbic acid, and also for total lysine, 'reactive lysine' and 'lysine as lactulosyl-lysine'. Storage at 60 degrees caused rapid destruction of folic acid (53% loss at 4 weeks) and slower loss of thiamin, vitamin B6 and pantothenic acid (18% at 8 weeks). There was no change in the content of riboflavin, biotin, nicotinic acid and vitamin B12. At 70 degrees the rate of destruction of the four labile vitamins was much increased; 18% or less survived at 4 weeks. At 37 degrees and 40 g water/kg there was little change in total and 'reactive' lysine during storage for 57 d. Lactulosyl-lysine was demonstrably present but at low concentration. There was considerable loss of folate (72%) and ascorbate (91%) during storage for 30 d in O2, but no significant loss in N2. Thiamin fell by approximately 12% in 57 d, equally in O2 and N2. The content of the remaining vitamins was unchanged. At 100 g water/kg there were progressive Maillard changes. During 27 d in N2 the colour changed from cream to pale brown, but in O2 there was no perceptible colour change. Total lysine fell by 20% in 27 d, and 'reactive lysine' by 30%. Folate was stable during 16 d in N2, but largely (94%) destroyed in O2. Ascorbic acid was also destroyed in N2 as in O2. Thiamin fell by 41% in 27 d, equally in O2 and N2. Vitamin B6 was more labile, especially in N2, falling by 71% in 16 d. With skimmed-milk powder containing 100

  8. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    SciTech Connect

    Kobayashi, Y.; Tsunesada, Y.; Tokuno, H.; Kakimoto, F.; Tomida, T.

    2011-09-22

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (X{sub max}) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  9. Simulations of warm tropical conditions with application to middle Pliocene atmospheres

    NASA Astrophysics Data System (ADS)

    Barreiro, M.; Philander, G.; Pacanowski, R.; Fedorov, A.

    2006-03-01

    During the early and mid-Pliocene, the period from 5 to 3 million years ago, approximately, the Earth is believed to have been significantly warmer than it is today, but the reasons for the higher temperatures are unclear. This paper explores the impact of recent findings that suggest that, at that time, cold surface waters were absent from the tropical and subtropical oceanic upwelling zones. El Niño was in effect a perennial rather than intermittent phenomenon, and sea surface temperatures in low latitudes were essentially independent of longitude. When these conditions are specified as the lower boundary condition for an atmospheric GCM, we find that the trade winds along the equator, and hence the Walker Circulation, collapse. The low-level stratus clouds in low latitudes diminish greatly, thus reducing the albedo of the Earth. The atmospheric concentration of water vapor increases, and enhanced latent heat release due to stronger evaporation warms up the tropical atmosphere, particularly between 40°S and 20°N. Moreover, teleconnection patterns from the Pacific induce a warming over North America that is enhanced by surface albedo feedback, a process that may have helped to maintain this region ice-free before 3 Ma. The results presented here indicate that the suggested absence of cold surface waters from the tropical and subtropical oceanic upwelling zones could have contributed significantly to the Pliocene warmth.

  10. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1991-01-01

    Laboratory measurements of microwave and millimeter wave properties of the simulated atmosphere of the outer planets and their satellites has continued. One of the focuses is on the development of a radiative transfer model of the Jovian atmosphere at wavelengths from 1 mm to 10 cm. This modeling effort led to laboratory measurements of the millimeter wave opacity of hydrogen sulfide (H2S) under simulated Jovian conditions. Descriptions of the modeling effort, the Laboratory experiment, and the observations are presented. Correlative studies of measurements with Pioneer-Venus radio occultation measurements with longer wavelength emission measurements have provided new ways for characterizing temporal and spatial variations in the abundance of both gases H2SO4 and SO2, and for modeling their roles in the subcloud atmosphere. Laboratory measurements were conducted on 1.35 cm (and 13 cm) opacity of gaseous SO2 and absorptivity of gaseous SO2 at the 3.2 mm wavelength under simulated Venus conditions. Laboratory measurements were completed on millimeter wave dielectric properties of liquid H2SO4, in order to model the effects of the opacity of the clouds of Venus onto millimeter wave emission spectrum.

  11. Effect of shadowing on survival of bacteria under conditions simulating the Martian atmosphere and UV radiation.

    PubMed

    Osman, Shariff; Peeters, Zan; La Duc, Myron T; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

    2008-02-01

    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-microm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-microm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (approximately 5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

  12. Monitoring and ANN modeling of coal stockpile behavior under different atmospheric conditions

    SciTech Connect

    Ozdeniz, A.H.; Ozbay, Y.; Yilmaz, N.; Sensogut, C.

    2008-07-01

    In this study, an industrial-sized stockpile of 5 m width, 4 m height, and 10 m length was built in a coal stock area to investigate coal stockpile behavior under different atmospheric conditions. The effective parameters on the coal stockpile that were time, weather temperature, atmospheric pressure, air humidity, velocity, and direction of wind values were automatically measured by means of a computer-aided measurement system to obtain Artificial Neural Network (ANN) input data. The coal stockpiles, which should be continuously observed, are capable of spontaneous combustion and then causing serious economical losses due to the mentioned parameters. Afterwards, these measurement values were used for training and testing of the ANN model. Comparison of the experimental and ANN results, accuracy rates of training, and testing were found as 98.6% and 98.7%, respectively. It is shown that possible coal stockpile behavior with this ANN model is powerfully estimated.

  13. Investigation of coal stockpiles of Tuncbilek thermal power plant with respect to time under atmospheric conditions

    SciTech Connect

    Ozdeniz, A.H.

    2009-07-01

    Thermal power plants have delayed the coal that they will use at stockpiles mandatorily. If these coal stockpiles remain at the stockyards over a certain period of time, a spontaneous combustion can be started itself. Coal stocks under combustion threat can cost too much economically to coal companies. Therefore, it is important to take some precautions for saving the stockpiles from the spontaneous combustion. In this research a coal stockpile at Tuncbilek Thermal Power Plant which was formed in 5 m wide, 10 m long, and 3 m height with a weight of 120 tons to observe internal temperature changes with respect to time under normal atmospheric conditions. Later, internal temperature measurements were obtained at 20 points distributed all over two layers in the stockpile. The parameters, such as air temperature, humidity, atmosphere pressure, wind speed and direction, which are effective on the stockpiles, were measured and used to obtain the graphs of stockpiles' internal temperature.

  14. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1986-01-01

    The recognition of the need to make laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressure which correspond to the altitudes probed by radio occultation experiments, and over a range of frequencies which correspond to both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. Construction was completed of the outer planets simulator and measurements were conducted of the microwave absorption and refraction from nitrogen under simulated Titan conditions. The results of these and previous laboratory measurements were applied to a wide range of microwave opacity measurements, in order to derive constituent densities and distributions in planetary atmospheres such as Venus.

  15. Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations.

    PubMed

    Manoli, Gabriele; Domec, Jean-Christophe; Novick, Kimberly; Oishi, Andrew Christopher; Noormets, Asko; Marani, Marco; Katul, Gabriel

    2016-06-01

    Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation of young plantations replacing old forest in the southern United States will alter key aspects of the hydrologic cycle, including convective rainfall, which is the focus of the present work. Ecosystem fluxes of sensible (Hs) and latent heat (LE) and large-scale, slowly evolving free atmospheric temperature and water vapor content are known to be first-order controls on the formation of convective clouds in the atmospheric boundary layer. These controlling processes are here described by a zero-order analytical model aimed at assessing how plantations of different ages may regulate the persistence and transition of the atmospheric system between cloudy and cloudless conditions. Using the analytical model together with field observations, the roles of ecosystem Hs and LE on convective cloud formation are explored relative to the entrainment of heat and moisture from the free atmosphere. Our results demonstrate that cloudy-cloudless regimes at the land surface are regulated by a nonlinear relation between the Bowen ratio Bo=Hs/LE and root-zone soil water content, suggesting that young/mature pines ecosystems have the ability to recirculate available water (through rainfall predisposition mechanisms). Such nonlinearity was not detected in a much older pine stand, suggesting a higher tolerance to drought but a limited control on boundary layer dynamics. These results enable the generation of hypotheses about the impacts on convective cloud formation driven by afforestation/deforestation and groundwater depletion projected to increase following increased human population in the

  16. Radical product yields from the ozonolysis of short chain alkenes under atmospheric boundary layer conditions.

    PubMed

    Alam, Mohammed S; Rickard, Andrew R; Camredon, Marie; Wyche, Kevin P; Carr, Timo; Hornsby, Karen E; Monks, Paul S; Bloss, William J

    2013-11-27

    The gas-phase reaction of ozone with unsaturated volatile organic compounds (VOCs), alkenes, is an important source of the critical atmospheric oxidant OH, especially at night when other photolytic radical initiation routes cannot occur. Alkene ozonolysis is also known to directly form HO2 radicals, which may be readily converted to OH through reaction with NO, but whose formation is poorly understood. We report a study of the radical (OH, HO2, and RO2) production from a series of small alkenes (propene, 1-butene, cis-2-butene, trans-2-butene, 2-methylpropene, 2,3-dimethyl-2-butene (tetramethyl ethene, TME), and isoprene). Experiments were performed in the European Photoreactor (EUPHORE) atmospheric simulation chamber, with OH and HO2 levels directly measured by laser-induced fluorescence (LIF) and HO2 + ΣRO2 levels measured by peroxy-radical chemical amplification (PERCA). OH yields were found to be in good agreement with the majority of previous studies performed under comparable conditions (atmospheric pressure, long time scales) using tracer and scavenger approaches. HO2 yields ranged from 4% (trans-2-butene) to 34% (2-methylpropene), lower than previous experimental determinations. Increasing humidity further reduced the HO2 yields obtained, by typically 50% for an RH increase from 0.5 to 30%, suggesting that HOx production from alkene ozonolysis may be lower than current models suggest under (humid) ambient atmospheric boundary layer conditions. The mechanistic origin of the OH and HO2 production observed is discussed in the context of previous experimental and theoretical studies. PMID:24171583

  17. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1986-01-01

    After long arduous work with the simulator, measurements of the refractivity and absorptivity of nitrogen under conditions similar to those for Titan were completed. The most significant measurements, however, were those of the microwave absorption from gaseous ammonia under simulated conditions for the Jovian atmospheres over wavelengths from 1.3 to 22 cm. The results of these measurements are critical in that they confirm the theoretical calculation of the ammonia opacity using the Ben-Reuven lineshape. The application of both these results, and results obtained previously, to planetary observations at microwave frequencies were especially rewarding. Applications of the results for ammonia to radio astronomical observations of Jupiter in the 1.3 to 20 cm wavelength range and the application of results for gaseous H2SO4 under simulated Venus conditions are discussed.

  18. Impact of the Atmospheric Thickness on the Atmospheric Downwelling Longwave Radiation and Snowmelt under Clear-Sky Conditions in the Arctic and Subarctic.

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Stamnes, K.; Bowling, S. A.

    2001-03-01

    Studies show that the energy available to melt snow at high latitudes is almost exclusively provided by radiation. Solar energy determines the period of possible snowmelt, while downwelling atmospheric longwave radiation modifies the timing and triggers the onset of snowmelt. Atmospheric thickness, defined as the vertical distance between the 500- and 1000-mb pressure surfaces, is directly related to the mean temperature and water vapor path of an atmospheric layer and thus has a direct influence on the downwelling longwave radiation and snowmelt. A comprehensive radiative transfer model was applied to calculate the downwelling longwave radiation to the snow surface over the period of snowmelt from 1980 through 1991 using radiosonde data obtained at Barrow and McGrath, Alaska, under clear-sky conditions. The results indicate that the atmospheric thickness has a positive impact on downwelling longwave radiation, which ranges from about 130 W m2 for an atmospheric thickness of 4850 m to about 280 W m2 for an atmospheric thickness of 5450 m. This study demonstrates that atmospheric water vapor path has a greater impact on atmospheric downwelling longwave radiation to the snow surface than the mean atmospheric temperature. This study also indicates that when the near-surface air temperature is used to infer downwelling longwave radiation, significant errors can occur. Thus, compared with the results obtained from the atmospheric radiative transfer model, the empirical formula due to Parkinson and Washington underestimates the downwelling longwave radiation when the near-surface air temperature is relatively high and overestimates it when the near-surface air temperature is relatively low. Investigations of the relationship between the atmospheric thickness and the snowmelt onset were conducted. Results indicate that for the period from 1980 through 1991, an atmospheric thickness of 5250 m at Barrow and 5200 m at McGrath in Alaska was sufficient to trigger the onset of

  19. Atmospheric response to Ice Age conditions: Climatology near the Earth's surface

    NASA Astrophysics Data System (ADS)

    Lautenschlager, M.; Herterich, K.

    1990-12-01

    We present a 6-year simulation of the ice age atmosphere using the T21 Atmospheric General Circulation Model (AGCM) of the European Centre for Medium-Range Weather Forecasts (ECMWF). The lower boundary conditions (18 kyr B.P.) were taken from CLIMAP Project Members (1981). The analysis is restricted to the surface climatology for two reasons: The surface fields are the test data derived from the geological record on land, and they define the upper boundary conditions for simulating the glacial ocean. Model results are shown for the mean annual surface fields of temperature, wind, and precipitation. In the global average the surface temperature was 4.7°C cooler compared to the present temperature. The wind strength increased in mid-latitudes and decreased in tropical trade wind regions. Precipitation did not change significantly in the global average; however, precipitation decreased over land and increased over the ocean. Most of the difference patterns between the present conditions and the ice age climate were statistically significant. The simulated surface climatology is roughly consistent with the paleogeological evidence and with numerical AGCM simulations of other authors. This suggests that presently available AGCMs, including the ECMWF model (T21), are able to describe climates far away from the present, although internal parameterizations were tuned to present data sets.

  20. Erosion processes in molassic cliffs: the role of the rock surface temperature and atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Carrea, Dario; Abellán, Antonio; Guerin, Antoine; Jaboyedoff, Michel; Voumard, Jérémie

    2014-05-01

    The morphology of the Swiss Plateau is modeled by numerous steep cliffs of Molasse. These cliffs are mainly composed of sub-horizontal alternated layers of sandstone, shale and conglomerates deposed in the Alps foreland basin during the Tertiary period. These Molasse cliffs are affected by erosion processes inducing numerous rockfall events. Thus, it is relevant to understand how different external factors influence Molasse erosion rates. In this study, we focus on analyzing temperature variation during a winter season. As pilot study area we selected a cliff which is formed by a sub-horizontal alternation of outcropping sandstone and shale. The westward facing test site (La Cornalle, Vaud, Switzerland), which is a lateral scarp of a slow moving landslide area, is currently affected by intense erosion. Regarding data acquisition, we monitored both in-situ rock and air temperatures at 15 minutes time-step since October 2013: (1) on the one hand we measured Ground Surface Temperature (GST) at near-surface (0.1 meter depth) using a GST mini-datalogger M-Log5W-Rock model; (2) On the other hand we monitored atmospheric conditions using a weather station (Davis Vantage pro2 plus) collecting numerous parameters (i.e. temperature, irradiation, rain, wind speed, etc.). Furthermore, the area was also seasonally monitored by Ground-Based (GB) LiDAR since 2010 and monthly monitored since September 2013. In order to understand how atmospheric conditions (such as freeze and thaw effect) influence the erosion of the cliff, we modeled the temperature diffusion through the rock mass. To this end, we applied heat diffusion and radiation equation using a 1D temperature profile, obtaining as a result both temperature variations at different depths together with the location of the 0°C isotherm. Our model was calibrated during a given training set using both in-situ rock temperatures and atmospheric conditions. We then carried out a comparison with the rockfall events derived from the

  1. Neutral molecular cluster formation of sulfuric acid-dimethylamine observed in real time under atmospheric conditions.

    PubMed

    Kürten, Andreas; Jokinen, Tuija; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S; Kulmala, Markku; Worsnop, Douglas R; Curtius, Joachim

    2014-10-21

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even though the neutral particles are stable against evaporation from the SA dimer onward, the formation rates of particles at 1.7-nm size, which contain about 10 SA molecules, are up to 4 orders of magnitude smaller compared with those of the dimer due to coagulation and wall loss of particles before they reach 1.7 nm in diameter. This demonstrates that neither the atmospheric particle formation rate nor its dependence on SA can simply be interpreted in terms of cluster evaporation or the molecular composition of a critical nucleus. PMID:25288761

  2. Neutral molecular cluster formation of sulfuric acid–dimethylamine observed in real time under atmospheric conditions

    PubMed Central

    Kürten, Andreas; Jokinen, Tuija; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M.; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P.; Riccobono, Francesco; Rissanen, Matti P.; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H.; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M.; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S.; Kulmala, Markku; Worsnop, Douglas R.; Curtius, Joachim

    2014-01-01

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even though the neutral particles are stable against evaporation from the SA dimer onward, the formation rates of particles at 1.7-nm size, which contain about 10 SA molecules, are up to 4 orders of magnitude smaller compared with those of the dimer due to coagulation and wall loss of particles before they reach 1.7 nm in diameter. This demonstrates that neither the atmospheric particle formation rate nor its dependence on SA can simply be interpreted in terms of cluster evaporation or the molecular composition of a critical nucleus. PMID:25288761

  3. Nucleation of Ammonia Species under the Atmospheric Conditions of Giant Planets

    NASA Astrophysics Data System (ADS)

    Gebauer, S.; Patzer, A. B. C.

    The visual appearance of giant planets is mainly determined by their outer atmospheric cloud layers. Therefore, it is important to know which chemical species might condense and how the condensate, solid or maybe liquid, nucleate in detail to finally form cloudy structures in such planetary atmospheres. In case of Jupiter thermodynamic considerations reveal ammonia ice to be the outermost condensate to form a cloud deck at less than one bar, followed by a second cloud layer between approximately one and two bar, which is proposed to be formed by solid ammonium hydrogensulfide particles (cf. e.g. Ackerman & Marley (2001), Atreya et al. (1999), Burrows & Sharp (1998), Rossow (1978), Sudarsky et al. (2003), Weidenschilling & Lewis (1973)). Based on the so-called scaled nucleation theory (Hale (1986)) a theoretical description for the heterogeneous deposition nucleation of ammonia species has been derived here in analogy to the heterogeneous nucleation concept for water ice in the terrestrial atmosphere by Pruppacher & Klett (1996). This approach is applied to typical Jovian atmospheric conditions and first results are discussed e.g. in comparison to the observed depletion of NH3 molecules in the troposphere of Jupiter. References: Ackerman A.S. & Marley M.S. 2001, ApJ, 556, 872 Atreya S.K., Wong M.H., Owen T.C., Mahaffy P.R., Niemann H.B., de Pater I. , Drossart P. & Encrenaz Th. 1999, P&SS, 47, 1243 Burrows A. & Sharp C.M. 1999, ApJ, 512, 843 Hale B. 1986, Phys. Rev. A, 33,4156 Pruppacher H.R. & Klett J.D., Microphysics of Clouds and Precipitation, Atmos. and Ocean. Scie. Lib., 2nd ed., 1996 Rossow W.B. 1978, Icar. 36, 1 Sudarsky D., Burrows A. & Hubeny I. 2003, ApJ, 588, 1121 Weidenschilling S.J. & Lewis J.S. 1973, Icar. 20, 405

  4. Corrosion of aluminum and copper thin films under simulated atmospheric conditions in laboratory tests

    SciTech Connect

    Li, W.; Raman, A.; Diwan, R.; Bhattacharya, P.K.

    1998-12-31

    Corrosion characteristics of Al and Cu thin films have been studied in cyclic fog tests using tap water fog and fog created with 0.1% NaCl solution in tap water. Likewise, their corrosion features have been analyzed in continuous immersion testing in the laboratory in distilled water, tap water, in 0.1% NaCl and 3.5% NaCl solutions in distilled water. The corrosion potentials and the corrosion currents of these thin films change and reach steady state values after some time. However, steady state is not realized in 3.5% NaCl solutions. The corrosion current density data have been used to calculate lifetime of 1 {mu}m thick thin films of Al and Cu in the various tests, and assuming that the fog test data would hold under normal exposure conditions, life spans for these thin film sensor elements in actual exterior exposure have also been calculated. According to estimates, an Al-TF of about 1 {mu}m would last about 9 months in exterior exposure in chloride containing atmospheres, such as in the coastal regions, but would survive nearly 2 years in normal atmospheres not having acidic or chloride pollutants. On the contrary, 1 {mu}m thick Cu-TF would last only for about 2.5 months in chloride-laden environments, but would last for about 2 years in normal atmospheres. However, Cu-TF would be corroded off faster in slightly alkaline atmospheric condensate under total immersion situation. Lifetime estimates are presented and discussed.

  5. Frigate birds track atmospheric conditions over months-long transoceanic flights.

    PubMed

    Weimerskirch, Henri; Bishop, Charles; Jeanniard-du-Dot, Tiphaine; Prudor, Aurélien; Sachs, Gottfried

    2016-07-01

    Understanding how animals respond to atmospheric conditions across space is critical for understanding the evolution of flight strategies and long-distance migrations. We studied the three-dimensional movements and energetics of great frigate birds (Fregata minor) and showed that they can stay aloft for months during transoceanic flights. To do this, birds track the edge of the doldrums to take advantage of favorable winds and strong convection. Locally, they use a roller-coaster flight, relying on thermals and wind to soar within a 50- to 600-meter altitude band under cumulus clouds and then glide over kilometers at low energy costs. To deal with the local scarcity of clouds and gain longer gliding distances, birds regularly soar inside cumulus clouds to use their strong updraft, and they can reach altitudes of 4000 meters, where freezing conditions occur. PMID:27365448

  6. Influence of Geomagnetic and IMF conditions on High Latitude Upper Atmospheric winds and Temperatures

    NASA Astrophysics Data System (ADS)

    Dhadly, M. S.; Conde, M.; Emmert, J. T.

    2015-12-01

    We analyzed the climatological behavior of upper atmospheric winds (horizontal and vertical) and temperatures above Alaska by combining line-of-sight Doppler shifts of 630 nm optical emissions recorded during the 2011 and 2012 winters using a ground based all-sky wavelength scanning Doppler Fabry-Perot interferometer (SDI) located at Poker Flat (65.12N, 147.47W). The wide field of view covered a large geographic region above Alaska. This field was divided in software into multiple zones (115 used here), allowing independent spectra to be sampled from many directions simultaneously. As a result, it is capable of recording the wind field's spatial variations over a wide geographic region with high spatial resolution, and to resolve these variations over time. Although such climatological studies have been performed previously using satellites, models, and narrow field Fabry-Perot interferometers, there are no published climatological studies of thermospheric winds and temperatures using either SDI data or any other technique with comparable geographic coverage and resolution. Wind summary dial plots were produced to depict the climatology of the horizontal winds and temperatures for different geomagnetic conditions and orientation of interplanetary magnetic field (IMF). Results show that horizontal winds and temperatures had a strong dependence on geospace activity and orientation of IMF. The latitudinal shears in horizontal winds were stronger when geomagnetic conditions were active compared to the latitudinal shears for quiet conditions. Also, shears appeared earlier over Poker Flat when geomagnetic conditions were active. The latitudinal shears showed more dependence on IMF when geomagnetic conditions were active than they did during quieter conditions. F-region temperatures were higher under active geomagnetic conditions than during quiet conditions. They were also observed to be higher in pre-magnetic midnight sector (duskside) than they were post

  7. Evaporation from soils subjected to natural boundary conditions at the land-atmospheric interface

    NASA Astrophysics Data System (ADS)

    Smits, K.; Illngasekare, T.; Ngo, V.; Cihan, A.

    2012-04-01

    Bare soil evaporation is a key process for water exchange between the land and the atmosphere and an important component of the water balance in semiarid and arid regions. However, there is no agreement on the best methodology to determine evaporation under different boundary conditions at the land surface. This becomes critical in developing models that couples land to the atmosphere. Because it is difficult to measure evaporation from soil, with the exception of using lysimeters, numerous formulations have been proposed to establish a relationship between the rate of evaporation and soil moisture and/or soil temperature and thermal properties. Different formulations vary in how they partition available energy. A need exists to systematically compare existing methods to experimental data under highly controlled conditions not achievable in the field. The goal of this work is to perform controlled experiments under transient conditions of soil moisture, temperature and wind at the land/atmospheric interface to test different conceptual and mathematical formulations for the soil surface boundary conditions to develop appropriate numerical models to be used in simulations. In this study, to better understand the coupled water-vapor-heat flow processes in the shallow subsurface near the land surface, we modified a previously developed theory by Smits et al. [2011] that allows non-equilibrium liquid/gas phase change with gas phase vapor diffusion to better account for dry soil conditions. The model did not implement fitting parameters such as a vapor enhancement factor that is commonly introduced into the vapor diffusion coefficient as an arbitrary multiplication factor. In order to experimentally test the numerical formulations/code, we performed a two-dimensional physical model experiment under varying boundary conditions using test sand for which the hydraulic and thermal properties were well characterized. Precision data under well-controlled transient heat and

  8. Modeling Thermospheric Dynamics Under all Solar, Geomagnetic, and Lower Atmosphere Conditions

    NASA Astrophysics Data System (ADS)

    Fuller-Rowell, T. J.; Fedrizzi, M.; Fang, T. W.; Codrescu, M.; Negrea, C.; Lu, X.; Wu, F.

    2014-12-01

    During very active geomagnetic conditions, neutral thermospheric dynamics is dominated by magnetospheric momentum and energy input. Mid and high latitude horizontal winds can exceed many hundreds of meters per second, vertical winds many tens of meters per second, and the impulsive energy input can drive global wave surges of one to two hundred meters per second. The latitudinal change in global temperature and pressure from the energy input drives an altered circulation, neutral composition structure, and the disturbance dynamo, all of which have dramatic impact on the ionosphere. During more typical solar and geomagnetic activity conditions the balance between these solar and magnetospheric drivers, and forcing from the lower atmosphere, is not so clear. A whole spectrum of waves, including migrating and non-migrating tides and gravity waves, propagate from sources in the lower atmosphere, increase in amplitude, and drive winds throughout the thermosphere and at all latitudes. Some of these waves break in the mesosphere and lower thermosphere and mix the constituents. Some penetrate further into the thermosphere driving steep vertical gradients, and as they dissipate by molecular viscosity they deposit momentum. Much of the variability in electrodynamics is driven by the larger-scale tidal spectrum of waves driving neutral winds in the lower thermosphere dynamo region. The shorter period and smaller scale spectrum of gravity waves also drive neutral winds, and their impact is readily apparent in the ionosphere from incoherent scatter and dynasonde observations. The still sparse direct observations of neutral winds means that sometimes it is the impact on the ionosphere that must be used to indicate the presence of neutral atmospheric winds and waves.

  9. Atmospheric propagation of high power laser radiation at different weather conditions

    NASA Astrophysics Data System (ADS)

    Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Handke, Jürgen

    2016-05-01

    Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations between weather condition and laser beam characteristics DLR operates at Lampoldshausen a 130 m long free transmission laser test range. Sensors around this test range continuously monitor turbulence strength, visibility, precipitation, temperature, and wind speed. High power laser radiation is obtained by a TruDisk 6001 disk laser (Trumpf company) yielding a maximum output power of 6 kW at a wavelength of 1030 nm. The laser beam is expanded to 180 mm and focused along the beam path. Power and intensity distribution are measured before and after propagation, providing information about the atmospheric transmission and alterations of diameter and position of the laser beam. Backscattered laser light is acquired by a photo receiver. As a result, measurements performed at different weather conditions show a couple of correlations to the characteristics of the laser beam. The experimental results are compared to a numerical analysis. The calculations are based on the Maxwell wave equation in Fresnel approximation. The turbulence is considered by the introduction of phase screens and the "von Karman" spectrum.

  10. Assessment of a surface-layer parameterization scheme in an atmospheric model for varying meteorological conditions

    NASA Astrophysics Data System (ADS)

    Anurose, T. J.; Bala Subrahamanyam, D.

    2014-06-01

    The performance of a surface-layer parameterization scheme in a high-resolution regional model (HRM) is carried out by comparing the model-simulated sensible heat flux (H) with the concurrent in situ measurements recorded at Thiruvananthapuram (8.5° N, 76.9° E), a coastal station in India. With a view to examining the role of atmospheric stability in conjunction with the roughness lengths in the determination of heat exchange coefficient (CH) and H for varying meteorological conditions, the model simulations are repeated by assigning different values to the ratio of momentum and thermal roughness lengths (i.e. z0m/z0h) in three distinct configurations of the surface-layer scheme designed for the present study. These three configurations resulted in differential behaviour for the varying meteorological conditions, which is attributed to the sensitivity of CH to the bulk Richardson number (RiB) under extremely unstable, near-neutral and stable stratification of the atmosphere.

  11. Pore-Filling Ice Diffusively Derived From Atmospheric Water Vapor Under Mars Conditions

    NASA Astrophysics Data System (ADS)

    Hudson, T. L.; Aharonson, O.; Oslund, K.; Siegler, M.; Schorghofer, N.

    2007-12-01

    Conditions during previous climate epochs on Mars may have allowed subsurface ice to form via diffusion from a moist atmosphere. The deposition and recharge of such reservoirs is driven by subsurface humidity gradients; an atmospheric frostpoint greater than that of the subsurface results in a net influx of vapor which deposits in pore space as ice. Observations of the hydrogen distribution by Mars Odyssey indicate that the ice content of some high-latitude regions (e.g. Olympia Undae) exceeds 70% by volume. Reconciliation of this concentration with typically lower porosities of soils demands a process of ice segregation (lensing) and mechanical expansion, or direct precipitation. We investigate the possibility and consequences of volumetrically significant subsurface ice derived from the Mars atmosphere by vapor diffusion, at present and in the past. Experiments conducted at the Mars Simulation and Ice Laboratory at Caltech demonstrate that diffusion processes produce significant pore-filling ice under controlled lab conditions. Atmospherically derived water vapor is deposited within an initially dry porous medium subject to a strong (~15~K/cm) temperature gradient forcing a humidity gradient. This mimics the humidity gradient caused by time varying temperatures in the shallow subsurface of Mars with a static experimental setup. The vertical profile of water content is determined at the end of the experiment by gravimetric analysis and the thermal conductivity of the ice-bearing sample is calculated. Pore filling fractions up to 100% have been measured. Profiles with a marked transition in ice content at the frostpoint depth are observed corresponding to a subsurface ice table. The data enable calculation of time-varying diffusion coefficients which exhibit a reduction of up to an order of magnitude with respect to ice-free regolith. These are compared to numerical models of vapor diffusion incorporating ice deposition and pore constriction. Formation theories of

  12. Modeling large wind farms in conventionally neutral atmospheric boundary layers under varying initial conditions

    NASA Astrophysics Data System (ADS)

    Allaerts, Dries; Meyers, Johan

    2014-05-01

    Atmospheric boundary layers (ABL) are frequently capped by an inversion layer limiting the entrainment rate and boundary layer growth. Commonly used analytical models state that the entrainment rate is inversely proportional to the inversion strength. The height of the inversion turns out to be a second important parameter. Conventionally neutral atmospheric boundary layers (CNBL) are ABLs with zero surface heat flux developing against a stratified free atmosphere. In this regime the inversion-filling process is merely driven by the downward heat flux at the inversion base. As a result, CNBLs are strongly dependent on the heating history of the boundary layer and strong inversions will fail to erode during the course of the day. In case of large wind farms, the power output of the farm inside a CNBL will depend on the height and strength of the inversion above the boundary layer. On the other hand, increased turbulence levels induced by wind farms may partially undermine the rigid lid effect of the capping inversion, enhance vertical entrainment of air into the farm, and increase boundary layer growth. A suite of large eddy simulations (LES) is performed to investigate the effect of the capping inversion on the conventionally neutral atmospheric boundary layer and on the wind farm performance under varying initial conditions. For these simulations our in-house pseudo-spectral LES code SP-Wind is used. The wind turbines are modelled using a non-rotating actuator disk method. In the absence of wind farms, we find that a decrease in inversion strength corresponds to a decrease in the geostrophic angle and an increase in entrainment rate and geostrophic drag. Placing the initial inversion base at higher altitudes further reduces the effect of the capping inversion on the boundary layer. The inversion can be fully neglected once it is situated above the equilibrium height that a truly neutral boundary layer would attain under the same external conditions such as

  13. Conditionally Averaged Large-Scale Motions in the Neutral Atmospheric Boundary Layer: Insights for Aeolian Processes

    NASA Astrophysics Data System (ADS)

    Jacob, Chinthaka; Anderson, William

    2016-06-01

    Aeolian erosion of flat, arid landscapes is induced (and sustained) by the aerodynamic surface stress imposed by flow in the atmospheric surface layer. Conceptual models typically indicate that sediment mass flux, Q (via saltation or drift), scales with imposed aerodynamic stress raised to some exponent, n, where n > 1 . This scaling demonstrates the importance of turbulent fluctuations in driving aeolian processes. In order to illustrate the importance of surface-stress intermittency in aeolian processes, and to elucidate the role of turbulence, conditional averaging predicated on aerodynamic surface stress has been used within large-eddy simulation of atmospheric boundary-layer flow over an arid, flat landscape. The conditional-sampling thresholds are defined based on probability distribution functions of surface stress. The simulations have been performed for a computational domain with ≈ 25 H streamwise extent, where H is the prescribed depth of the neutrally-stratified boundary layer. Thus, the full hierarchy of spatial scales are captured, from surface-layer turbulence to large- and very-large-scale outer-layer coherent motions. Spectrograms are used to support this argument, and also to illustrate how turbulent energy is distributed across wavelengths with elevation. Conditional averaging provides an ensemble-mean visualization of flow structures responsible for erosion `events'. Results indicate that surface-stress peaks are associated with the passage of inclined, high-momentum regions flanked by adjacent low-momentum regions. Fluid in the interfacial shear layers between these adjacent quasi-uniform momentum regions exhibits high streamwise and vertical vorticity.

  14. Dependence of Positive and Negative Sprite Morphology on Lightning Characteristics and Upper Atmospheric Ambient Conditions

    NASA Astrophysics Data System (ADS)

    Qin, J.; Celestin, S. J.; Pasko, V. P.

    2012-12-01

    Carrot sprites, exhibiting both upward and downward propagating streamers, and columniform sprites, characterized by predominantly vertical downward streamers, represent two distinct morphological classes of lightning driven transient luminous events in the upper atmosphere. In the present work, a two-dimensional cylindrically symmetric plasma fluid model is applied in framework of a two-step technique, in which we couple the large-scale halo dynamics and development of small-scale streamers [Qin et al., GRL, 39, L05810, 2012]. The modeling is used to simulate sprite-halo events over a timescale of 5 ms in order to study the dependence of sprite morphology on lightning characteristics and upper atmospheric ambient conditions. The most significant associative detachment process O-+N2→e+N2O [e.g., Liu, JGR, 117, A03308, 2012] in sprite chemistry has been taken into account. It is found that lightning characteristics, namely the total charge moment change, the impulsiveness of the initial lightning pulse, the continuing current, and the lightning polarity, have a significant impact on sprite morphology. For example, it is found that columniform sprites are produced in sub-breakdown conditions, and that continuing current is of essential importance to the development of the upper diffuse region of carrot sprites. Most interestingly, we suggest that negative sprites should be necessarily carrot sprites produced by large charge moment changes. We also find different charge moment change thresholds for the initiation of positive and negative sprites, which are 320 C km and 500 C km, respectively, under typical nighttime conditions assumed in this study. This difference represents one of the major factors in the polarity asymmetry between +CGs and -CGs in producing sprite streamers. We further demonstrate that lower magnitude of ambient mesospheric conductivity leads to smaller threshold charge moment changes required for the production of carrot sprites.

  15. Optimality and dynamic equilibrium conditions in a simulated hillslope under periodic, arid atmospheric forcing

    NASA Astrophysics Data System (ADS)

    Kollet, S. J.

    2014-12-01

    Theories of optimality and self-organization are appealing when dealing with non-linear systems, because based on first principles of thermodynamic these theories may lead to an intuitive interpretation and prediction of absolute values, directions, and interactions of gradients and fluxes, and universal inference laws for effective conductances. In this context, for example, the maximum entropy production principle received attention, because of its foundation in non-equilibrium thermodynamics, which appears to be useful in e.g., eco-hydrologic and atmospheric applications. A number of studies successfully applied this principle in the optimization of conductances in simplified and well-mixed open systems with external (periodic) forcing. In support-scale simulations of a variably saturated hillslope, the study presented here relaxes major simplifying assumptions by applying a realistic, arid atmospheric time series in spinup simulations to create a dynamic equilibrium utilizing the integrated hydrologic model ParFlow-CLM. The simulated hillslope exhibits time-varying internal circulation patterns due to the periodic atmospheric forcing, topography, and also heterogeneity by utilizing and optimizing all degrees of freedom provided by the soil-water retention relationship and free-moving water table. Because of the extreme non-linearity of variably saturated flow under arid climate conditions, the system is never well mixed and optimality principles relying on time-integrated gradients and fluxes do not appear to be applicable in the currently available theoretical framework. Here, integrated support-scale simulations may be useful in deriving novel theories for the application to real systems in future.

  16. RAMS-forecasts comparison of typical summer atmospheric conditions over the Western Mediterranean coast

    NASA Astrophysics Data System (ADS)

    Gómez, I.; Caselles, V.; Estrela, M. J.; Niclòs, R.

    2014-08-01

    The Regional Atmospheric Modeling System (RAMS) has been used in order to perform a high-resolution numerical simulation of two meteorological events related to the most common atmospheric environments during the summer over the Western Mediterranean coast: mesoscale circulations and western synoptic advections. In this regard, we take advantage of the operational RAMS configuration running within the real-time forecasting system environment already implemented over this Mediterranean area, precisely in the Valencia Region and nearby areas. The attention of this paper is especially focused on identifying the main features of both events and the ability of the model in resolving the associated characteristics as well as in performing a comprehensive evaluation of the model by means of diverse meteorological observations available within the selected periods over the area of study. Additionally, as this paper is centred in RAMS-based forecasts, two simulations are operated applying the most two recent versions of the RAMS model implemented in the above-mentioned system: RAMS 4.4 and RAMS 6.0. Therefore, a comparison among both versions of the model has been performed as well. Finally, it is our intention to contrast the RAMS forecasts for two completely different atmospheric conditions common with the area of study in the summer. A main difference between the simulation of both meteorological situations has been found in the humidity. In this sense, whilst the model underestimates this magnitude considering the mesoscale event, especially at night time, the model reproduces the daily humidity properly under the western synoptic advection.

  17. Oceanographic and atmospheric conditions on the continental shelf north of the Monterey Bay during August 2006

    NASA Astrophysics Data System (ADS)

    Ramp, Steven R.; Lermusiaux, Pierre F. J.; Shulman, Igor; Chao, Yi; Wolf, Rebecca E.; Bahr, Frederick L.

    2011-09-01

    A comprehensive data set from the ocean and atmosphere was obtained just north of the Monterey Bay as part of the Monterey Bay 2006 (MB06) field experiment. The wind stress, heat fluxes, and sea surface temperature were sampled by the Naval Postgraduate School's TWIN OTTER research aircraft. In situ data were collected using ships, moorings, gliders and AUVs. Four data-assimilating numerical models were additionally run, including the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS ®) model for the atmosphere and the Harvard Ocean Prediction System (HOPS), the Regional Ocean Modeling System (ROMS), and the Navy Coastal Ocean Model (NCOM) for the ocean. The scientific focus of the Adaptive Sampling and Prediction Experiment (ASAP) was on the upwelling/relaxation cycle and the resulting three-dimensional coastal circulation near a coastal promontory, in this case Point Año Nuevo, CA. The emphasis of this study is on the circulation over the continental shelf as estimated from the wind forcing, two ADCP moorings, and model outputs. The wind stress during August 2006 consisted of 3-10 day upwelling favorable events separated by brief 1-3 day relaxations. During the first two weeks there was some correlation between local winds and currents and the three models' capability to reproduce the events. During the last two weeks, largely equatorward surface wind stress forced the sea surface and barotropic poleward flow occurred over the shelf, reducing model skill at predicting the circulation. The poleward flow was apparently remotely forced by mesoscale eddies and alongshore pressure gradients, which were not well simulated by the models. The small, high-resolution model domains were highly reliant on correct open boundary conditions to drive these larger-scale poleward flows. Multiply-nested models were no more effective than well-initialized local models in this respect.

  18. Plasmid load adversely affects growth and gluconic acid secretion ability of mineral phosphate-solubilizing rhizospheric bacterium Enterobacter asburiae PSI3 under P limited conditions.

    PubMed

    Sharma, Vikas; Archana, G; Naresh Kumar, G

    2011-01-20

    Effect of the metabolic load caused by the presence of plasmids on mineral phosphate-solubilizing (MPS) Enterobacter asburiae PSI3, was monitored with four plasmid cloning vectors and one native plasmid, varying in size, nature of the replicon, copy number and antibiotic resistance genes. Except for one plasmid, the presence of all other plasmids in E. asburiae PSI3 resulted in the loss of the MPS phenotype as reflected by the failure to bring about a drop in pH and release soluble P when grown in media containing rock phosphate (RP) as the sole P source. When 100 μM soluble P was supplemented along with RP, the adverse effects of plasmids on MPS phenotype and on growth parameters was reduced for some plasmid bearing derivatives, as monitored in terms of specific growth rates, glucose consumed, gluconic acids yields and P released. When 10 mM of soluble P as the only P source, was added to the medium all transformants showed growth and pH drop comparable with native strain. It may be concluded that different plasmids impose, to varying extents, a metabolic load in the phosphate-solubilizing bacterium E. asburiae PSI3 and results in diminishing its growth and P-solubilizing ability in P deficient conditions. PMID:20171856

  19. Associations between childhood adversity, adult stressful life events, and past-year drug use disorders in the National Epidemiological Study of Alcohol and Related Conditions (NESARC)

    PubMed Central

    Myers, Bronwyn; McLaughlin, Katie A.; Wang, Shuai; Blanco, Carlos; Stein, Dan J.

    2014-01-01

    Stress sensitization, whereby CA lowers tolerance to later stressors, has been proposed as a potential mechanism explaining the association between exposure to childhood adversities (CA) and drug use disorders in adulthood. However this mechanism remains untested. This paper begins to address this gap through exploring associations between CA exposure and stressful events in adulthood for predicting drug use disorders. We used data drawn from Wave 2 of the U.S. National Epidemiological Survey of Alcohol and Related Conditions (n=34,653) to explore whether the association between past-year stressful life events and the 12-month prevalence of disordered cannabis, stimulant and opiate use varied by the number of types of CA that an individual was exposed to. Past-year stressful life events were associated with an increased risk of cannabis, stimulant and opiate use disorders among men and women. Exposure to CA was associated with increased risk for disordered cannabis use among men and women and opiate use among men only. Finally, we found significant associations between exposure to CA and past year stressful life events in predicting disordered drug use, but only for women in relation to disordered stimulant and opiate use. Findings are suggestive of possible stress sensitization effects in predicting disordered stimulant and opiate use among women. Implications of these findings for the prevention and treatment of drug use disorders and for future research are discussed. PMID:25134042

  20. On the analytic and numeric optimisation of airplane trajectories under real atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Gonzalo, J.; Domínguez, D.; López, D.

    2014-12-01

    From the beginning of aviation era, economic constraints have forced operators to continuously improve the planning of the flights. The revenue is proportional to the cost per flight and the airspace occupancy. Many methods, the first started in the middle of last century, have explore analytical, numerical and artificial intelligence resources to reach the optimal flight planning. In parallel, advances in meteorology and communications allow an almost real-time knowledge of the atmospheric conditions and a reliable, error-bounded forecast for the near future. Thus, apart from weather risks to be avoided, airplanes can dynamically adapt their trajectories to minimise their costs. International regulators are aware about these capabilities, so it is reasonable to envisage some changes to allow this dynamic planning negotiation to soon become operational. Moreover, current unmanned airplanes, very popular and often small, suffer the impact of winds and other weather conditions in form of dramatic changes in their performance. The present paper reviews analytic and numeric solutions for typical trajectory planning problems. Analytic methods are those trying to solve the problem using the Pontryagin principle, where influence parameters are added to state variables to form a split condition differential equation problem. The system can be solved numerically -indirect optimisation- or using parameterised functions -direct optimisation-. On the other hand, numerical methods are based on Bellman's dynamic programming (or Dijkstra algorithms), where the fact that two optimal trajectories can be concatenated to form a new optimal one if the joint point is demonstrated to belong to the final optimal solution. There is no a-priori conditions for the best method. Traditionally, analytic has been more employed for continuous problems whereas numeric for discrete ones. In the current problem, airplane behaviour is defined by continuous equations, while wind fields are given in a

  1. Acoustic properties and durability of liner materials at non-standard atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Gaeta, R. J., Jr.; Hsu, J. S.

    1994-01-01

    This report documents the results of an experimental study on how acoustic properties of certain absorbing liner materials are affected by nonstandard atmospheric conditions. This study was motivated by the need to assess risks associated with incorporating acoustic testing capability in wind tunnels with semicryogenic high Reynolds number aerodynamic and/or low pressure capabilities. The study consisted of three phases: 1) measurement of acoustic properties of selected liner materials at subatmospheric pressure conditions, 2) periodic cold soak and high pressure exposure of liner materials for 250 cycles, and 3) determination of the effect of periodic cold soak on the acoustic properties of the liner materials at subatmospheric conditions and the effect on mechanical resiliency. The selected liner materials were Pyrell foam, Fiberglass, and Kevlar. A vacuum facility was used to create the subatmospheric environment in which an impedance tube was placed to measure acoustic properties of the test materials. An automated cryogenic cooling system was used to simulate periodic cold soak and high pressure exposure. It was found that lower ambient pressure reduced the absorption effectiveness of the liner materials to varying degrees. Also no significant change in the acoustic properties occurred after the periodic cold soak. Furthermore, mechanical resiliency tests indicated no noticeable change.

  2. Influence of preonset land atmospheric conditions on the Indian summer monsoon rainfall variability

    NASA Astrophysics Data System (ADS)

    Rai, Archana; Saha, Subodh K.; Pokhrel, Samir; Sujith, K.; Halder, Subhadeep

    2015-05-01

    A possible link between preonset land atmospheric conditions and the Indian summer monsoon rainfall (ISMR) is explored. It is shown that, the preonset positive (negative) rainfall anomaly over northwest India, Pakistan, Afghanistan, and Iran is associated with decrease (increase) in ISMR, primarily in the months of June and July, which in turn affects the seasonal mean. ISMR in the months of June and July is also strongly linked with the preonset 2 m air temperature over the same regions. The preonset rainfall/2 m air temperature variability is linked with stationary Rossby wave response, which is clearly evident in the wave activity flux diagnostics. As the predictability of Indian summer monsoon relies mainly on the El Niño-Southern Oscillation (ENSO), the found link may further enhance our ability to predict the monsoon, particularly during a non-ENSO year.

  3. Water ice nucleation characteristics of JSC Mars-1 regolith simulant under simulated Martian atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Phebus, Bruce D.; Johnson, Alexandria V.; Mar, Brendan; Stone, Bradley M.; Colaprete, Anthony; Iraci, Laura T.

    2011-04-01

    Water ice clouds in the Martian atmosphere are governed by parameters such as number density and particle size distribution that in turn affect how they influence the climate. With some of the underlying properties of cloud formation well known only for Earth, extrapolations to Mars are potentially misleading. We report here continued laboratory experiments to identify critical onset conditions for water ice formation under Martian cloud forming temperatures and water partial pressures (155-182 K, 7.6 × 10-5 to 7.7 × 10-3 Pa H2O). By observing the 3 μm infrared band to monitor nucleation and growth, we observe significant temperature dependence in the nucleation of ice on JSC Mars-1 regolith simulant, with critical saturation ratios, Scrit, as high as 3.8 at 155 K. At temperatures below ˜180 K, ice nucleation on JSC Mars-1 requires significant supersaturation, potentially impacting the Martian hydrological cycle.

  4. A numerical study of wind turbine wakes under various atmospheric stability conditions

    NASA Astrophysics Data System (ADS)

    Xie, Shengbai

    The goal of this research is to investigate the properties of wind turbine wakes and their interactions with the atmospheric boundary layer (ABL) via large-eddy simulations (LES) with special emphasis on the effects of atmospheric stability. The ABL is considered stable when the ground surface is cooler than the air, unstable when the opposite happens, and neutral when the temperature effect is negligible. In the literature, neutral conditions have been studied extensively, whereas the effects of stability have not. A new LES code, named Wind Turbine and Turbulence Simulator (WiTTS), was developed based on finite-difference (FD) schemes. First, the code's sensitivity to numerous aspects of the FD LES, such as the subgrid-scale (SGS) model, resolution, numerical treatment of the convective term, and filter types, was analyzed by simulating a neutral ABL. It was found that the Lagrangian-averaged scale-dependent (LASD) SGS model performs better than other scale-invariant Smagorinsky-type models. Second, the WiTTS was used to study the wakes from a miniature wind turbine inside a wind tunnel, following the setup of past experimental and numerical studies. It was found that those wakes are spatially anisotropic, with lateral growth faster than the vertical. Based on this, a new wake model is proposed and the Gaussian-type self-similarity is obtained for this simplified scenario. Third, to study a more realistic ABL, the stability conditions have been considered by the Boussinesq approximation and by varying thermal conditions on the ground surface, together with a constant Coriolis force. The LES results indicate that the properties of utility-scale wind turbine wakes are strongly correlated to the stability conditions. The wake recovery is enhanced by the increased turbulence due to buoyant convection in the unstable ABL, while in the stable ABL the spreading of the wake is significantly larger in the lateral direction than in the vertical direction. The stability

  5. Transport of exhaust products in the near trail of a jet engine under atmospheric conditions

    SciTech Connect

    Karcher, B.

    1994-07-01

    The transport of exhaust effluents and the possibility of water ice contrail formation are investigated under the specific fluid dynamical conditions in the near exhaust trail of a subsonic jet aircraft at cruise altitude. By means of a computational model describing the two-dimensional turbulent mixing of a single jet of hot exhaust gas with the atmosphere, representative results are discussed on the temperature and saturation ratio evolutions of air parcels in the jet flow field as well as on radial distributions of exhaust effluents undergoing chemical reactions behind the nozzle exit with prescribed, typical net reaction rates. The results underline the importance of a simultaneous treatment of spatially resolved jet expansion together with microphysical and chemical processes, because this coupling leads to distinct concentration patterns for various classes of chemical reactants and is essential for the detailed prediction of contrails.

  6. Pathways towards risk: syndemic conditions mediate the effect of adversity on HIV risk behaviors among young men who have sex with men (YMSM).

    PubMed

    Herrick, Amy; Stall, Ron; Egan, James; Schrager, Sheree; Kipke, Michele

    2014-10-01

    Research shows that young men who have sex with men (YMSM) engage in higher rates of health risk behaviors and experience higher rates of negative health outcomes than their peers. The purpose of this study is to determine if the effects of adversity on HIV risk are mediated by syndemics (co-occurring health problems). Participants were 470 ethnically diverse YMSM ages 18 to 24 recruited between 2005 and 2006 and surveyed every 6 months for 24 months. Regression analyses examined the impact of adversity on syndemics (emotional distress, substance use, and problematic alcohol use) and the effects of both adversity and syndemics on HIV risk behaviors over time. Gay-related discrimination and victimization-among other adversity variables-were significantly associated with syndemics and condomless sex (CS). Syndemics mediated the effects of adversity on CS in all models. Adverse events impact HIV risk taking among YMSM through syndemics. These findings suggest that prevention programs aimed at reducing adversity may reduce both the synergistic effect of multiple psychosocial health problems and HIV risk taking. PMID:25146488

  7. Atmospheric conditions associated to an extreme rainfall event on Madeira Island (Portugal)

    NASA Astrophysics Data System (ADS)

    Couto, Flavio; Salgado, Rui; João Costa, Maria

    2013-04-01

    Located in the Noth Atlantic Ocean (32°75'N and 17°00'W), the Madeira Island presents favourable conditions for orographic precipitation development, sometimes responsible for high records and floods, such as on 20 February 2010, when the island was affected by the worst flash floods in its recent history, causing more than 40 deaths and huge economic losses. After this disaster, there is a growing interest in understanding the main mechanisms and atmospheric conditions that are relevant to the establishment of extreme rainfall and consequently flash flood occurrences in the island. This study describes the meteorological aspects associated to a case study of high rainfall amounts in Madeira on 25 January 2011. In this case, flash floods and socio-economic damages were not reported, but precipitation above 300 mm in less than 24 hours were observed in Madeira's highlands. The heavy rainfall episode is studied based on rain gauge and satellite observations, as well as numerical simulation with the Mesoscale Non-Hydrostatic Model (MESO-NH). The MESO-NH simulation initialized and forced by ECMWF analysis have been performed with 3 horizontal domains (9, 3 and 1 km resolution), making use of the grid nesting technique. The evolution of the mean sea level pressure field (MSLP) was analyzed from the outer domain outputs, while the other meteorological variables were further explored using the 1 km resolution results. The simulation showed that the orography is crucial in the formation and intensification of the localized heavy rainfall in the island. A remarkable aspect is the fact that this episode occurred in a low-cape environment. Related to the synoptic environment, this event was characterized by a low pressure system centered to the southeastern of the island, in opposition to the results obtained for other extreme events occurred in the past two years, when the high precipitation amounts were due to the effects of the orography on the passage of cold fronts

  8. Flow Forecasting via Artificial Neural Networks - A Study for Input Variables conditioned on atmospheric circulation

    NASA Astrophysics Data System (ADS)

    Panagoulia, D.; Trichakis, I.; Tsekouras, G. J.

    2012-04-01

    The paper compares the performance of different structures of Artificial Neural Networks (ANNs) for flow forecasting of the next day in the Mesochora catchment in Northwestern Greece with respect to different input variables. The input variables are historical data of previous days, such as: (a) flows, (b) temperatures conditioned on atmospheric circulation, and (c) rainfalls conditioned on atmospheric circulation too. The training algorithm is the stochastic training back-propagation process with decreasing functions of learning rate and momentum term, for which a calibration process is conducted regarding the crucial parameters values, such as the number of neurons, the kind of activation functions, the initial values and time parameters of learning rate and momentum term etc. The performance of each structure has been evaluated by different criterions, such as (i) the root mean square error (RMSE), (ii) the correlation index (R), (iii) the mean absolute percentage error (MAPE), (iv) the mean percentage error (MPE), (v) the mean percentage error (ME), (vi) the percentage volume in errors (VE), (vii) the percentage error in peak (MF), (viii) the normalized mean bias error (NMBE), (ix) the normalized root mean bias error (NRMSE), (x) the Nash-Sutcliffe model efficiency coefficient (E), (xi) the modified Nash-Sutcliffe model efficiency coefficient (E1), (xii) the threshold statistics (TSp%) for a level of absolute relative error of p% (=1%, 2%, 5%, 25%, 50% and 100%). Here, the calibration process has been based on the voting analysis of the (i) to (xi) criterions. The time period of long-term falling flow (1972-77) is divided in two sets: one for ANN training with the 80% of data and the other for ANN parameters' calibration with the 20% data. The test set for the final verification of behaviour of ANN structures encompasses the following long-term time period with falling flow (1987-92). From the aforementioned analysis the nonlinear behaviour between forecasted

  9. Regional frequency analysis conditioned on large-scale atmospheric or oceanic fields

    NASA Astrophysics Data System (ADS)

    Renard, Benjamin; Lall, Upmanu

    2014-12-01

    Many studies report that hydrologic regimes are modulated by large-scale modes of climate variability such as the El Niño Southern Oscillation (ENSO) or the North Atlantic Oscillation (NAO). Climate-informed frequency analysis models have therefore been proposed to condition the distribution of hydrologic variables on climate indices. However, standard climate indices may be poor predictors in some regions. This paper therefore describes a regional frequency analysis framework that conditions the distribution of hydrologic variables directly on atmospheric or oceanic fields, as opposed to predefined climate indices. This framework is based on a two-level probabilistic model describing both climate and hydrologic data. The climate data set (predictor) is typically a time series of atmospheric of oceanic fields defined on a grid over some area, while the hydrologic data set (predictand) is typically a regional data set of station data (e.g., annual average flow at several gauging stations). A Bayesian estimation framework is used, so that a natural quantification of uncertainties affecting hydrologic predictions is available. A case study aimed at predicting the number of autumn flood events in 16 catchments located in Mediterranean France using geopotential heights at 500 hPa over the North-Atlantic region is presented. The temporal variability of hydrologic data is shown to be associated with a particular spatial pattern in the geopotential heights. A cross-validation experiment indicates that the resulting probabilistic climate-informed predictions are skillful: their reliability is acceptable and they are much sharper than predictions based on standard climate indices and baseline predictions that ignore climate information.

  10. Regional frequency analysis conditioned on large-scale atmospheric or oceanic fields

    NASA Astrophysics Data System (ADS)

    Renard, Benjamin; Lall, Upmanu

    2015-04-01

    Many studies report that hydrologic regimes are modulated by large-scale modes of climate variability such as the El Niño Southern Oscillation (ENSO) or the North Atlantic Oscillation (NAO). Climate-informed frequency analysis models have therefore been proposed to condition the distribution of hydrologic variables on climate indices. However, standard climate indices may be poor predictors in some regions. This paper therefore describes a regional frequency analysis framework that conditions the distribution of hydrologic variables directly on atmospheric or oceanic fields, as opposed to predefined climate indices. This framework is based on a 2-level probabilistic model describing both climate and hydrologic data. The climate dataset (predictor) is typically a time series of atmospheric of oceanic fields defined on a grid over some area, while the hydrologic dataset (predictand) is typically a regional dataset of station data (e.g. annual peak flow at several gauging stations). A Bayesian estimation framework is used, so that a natural quantification of uncertainties affecting hydrologic predictions is available. A case study aimed at predicting the number of autumn flood events in 16 catchments located in Mediterranean France using geopotential heights at 500 hPa over the North-Atlantic region is presented. The temporal variability of hydrologic data is shown to be associated with a particular spatial pattern in the geopotential heights. A cross-validation experiment indicates that the resulting probabilistic climate-informed predictions are skillful: their reliability is acceptable and they are much sharper than predictions based on standard climate indices and baseline predictions that ignore climate information.

  11. The Influence of Atmospheric Conditions on the Production of Ozone during VOC Oxidation

    NASA Astrophysics Data System (ADS)

    Coates, J.; Butler, T. M.

    2015-12-01

    Tropospheric ozone is a short-lived climate forcing pollutant that is detrimental to human health and crop growth. Reactions involving volatile organic compounds (VOC) and nitrogen oxides (NOx) in the presence of sunlight produce ozone. Ozone production is a non-linear function of the concentrations of both NOx and VOC, with VOC acting as the "fuel" for ozone production and NOx as the "catalyst". Different VOC, due to their differing structure and carbon content, have different maximum potential to produce ozone. Due to different degrees of reactivity, VOC also differ in the time taken to reach this maximum ozone production potential under ideal conditions. Ozone production is also influenced by meteorological factors such as radiation, temperature, advection and mixing, which may alter the rate of ozone production, and the degree to which VOC are able to reach their maximum ozone production potential. Identifying the chemical and meteorological processes responsible for controlling the degree to which VOC are able to reach their maximum ozone production potential could inform decisions on emission control to efficiently tackle high levels of tropospheric ozone. In this study we use a boxmodel to determine the chemical processes affecting ozone production under different meteorological and chemical conditions. The chemistry scheme used by the boxmodel is "tagged" for each initial VOC enabling attribution of ozone production to its VOC source. We systematically vary a number of meteorological parameters along with the source of NOx within the box model to simulate a range of atmospheric conditions. These simulations are compared with a control simulation done under conditions of maximum ozone formation to determine which parameters affect the rate at which VOC produce ozone and the extent to which they reach their maximum potential to produce ozone. We perform multi-day simulations in order to examine whether these processes can influence ozone production over

  12. Molybdenum isotope fractionation in soils: Influence of redox conditions, organic matter, and atmospheric inputs

    NASA Astrophysics Data System (ADS)

    Siebert, C.; Pett-Ridge, J. C.; Opfergelt, S.; Guicharnaud, R. A.; Halliday, A. N.; Burton, K. W.

    2015-08-01

    Molybdenum isotope fractionation accompanying soil development is studied across three pedogenic gradients encompassing a range of controlling factors. These factors include variable redox conditions, organic matter content, Fe and Mn oxy(hydr)oxide content, mineral composition, degree of weathering, pH, type and amount of atmospheric inputs, age, climate, and underlying rock type. Soil profiles from the island of Maui (Hawaii) along a precipitation gradient ranging from 850 to 5050 mm mean annual precipitation show a decrease in average soil δ98Mo from -0.04 ± 0.11‰ at the driest, most oxic site, which is indistinguishable from the basalt parent material (-0.09 ± 0.08‰), to -0.33 ± 0.10‰ at the wettest, most reducing site. A suite of 6 Icelandic soils display a broad trend with heavier δ98Mo values (up to +1.50 ± 0.09‰) in soil horizons that are more weathered and have higher organic matter content. Selective extractions of Mo from different soil components indicate that the association with organic matter and silicate or Ti-oxide residue dominates retention of Mo in these soils, with adsorption on Fe and Mn oxy(hydr)oxides playing a lesser role. Across all basaltic soils, δ98Mo values are lighter in soils that exhibit the most net Mo loss relative to the parent material, and δ98Mo values are heavier in soils that exhibit net Mo gains. A well-drained regolith profile in the Luquillo Mountains of Puerto Rico developed on quartz diorite shows heavier δ98Mo values than the parent material (up to +0.71 ± 0.10‰ with an integrated profile average of +0.28 ± 0.10‰) in soil and shallower saprolite, despite overall moderate loss of 28% of Mo relative to the bedrock. However, the deeper saprolite is unfractionated from bedrock (-0.01 ± 0.10‰, quartz diorite bedrock) indicating that rock weathering dissolution processes and secondary clay formation do not fractionate Mo isotopes. Our data suggest that the Mo mass balance and isotope composition of

  13. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1988-01-01

    In the first half of this grant year, laboratory measurements were conducted on the millimeter-wave properties of atmospheric gases under simulated conditions for the outer planet. Significant improvements in the current system have made it possible to accurately characterize the opacity from gaseous NH3 at longer millimeter wavelengths (7 to 10 mm) under simulated Jovian conditions. In the second half of the grant year, it is hoped to extend such measurements to even shorter millimeter-wavelengths. Further analysis and application of the laboratory results to microwave and millimeter-wave absorption data for the outer planets, such as results from Voyager Radio Occultation experiments and earth-based radio astronomical observations will be continued. The analysis of available multispectral microwave opacity data from Venus, including data from the most recent radio astronomical ovservations in the 1.3 to 3.6 cm wavelength range and newly obtained Pioneer-Venus Radio Occulatation measurements at 13 cm, using the laboratory measurements as an interpretative tool will be pursued.

  14. Outer scale and Monin-Obukhov flux relationships of atmospheric turbulence under dry convective conditions

    NASA Astrophysics Data System (ADS)

    De Bruin, Henk; Hartogensis, Oscar

    2015-04-01

    In this study we will investigate the assumption that in the atmospheric surface layer the outer scale (L0) is proportional to the height above the surface, under dry convective conditions. For this purpose we analyzed raw sonic anemometers data collected at 3.5 m and at 9 m in a field campaign at the Santa Cruz Flats (32040.3190'N, 111032.641'W, 526 m of elevation) near Eloy, Arizona. For simplicity, we define the L0 as that separation distance at which the spatial correlation coefficient of air temperature at two points in the surface layer is 0.5. Then, according to the 2/3-Kolmogorov scaling law in the inertial sub-range, L0 is determined by the variance and the structure parameter of T . It is found that L0 does not scale with height. Possible reasons for this negative result will be discussed, by considering the methodology to determine structure parameters, Taylor's frozen turbulence hypothesis, effects of intermittency and Monin-Obukhov flux relationships for variance and structure parameter for T . The question is asked whether the concept of surface constant flux layer still holds under strong convective condition.

  15. Modeling the effects of a solid barrier on pollutant dispersion under various atmospheric stability conditions

    NASA Astrophysics Data System (ADS)

    Steffens, Jonathan T.; Heist, David K.; Perry, Steven G.; Zhang, K. Max

    2013-04-01

    There is a growing need for developing mitigation strategies for near-road air pollution. Roadway design is being considered as one of the potential options. Particularly, it has been suggested that sound barriers, erected to reduce noise, may prove effective at decreasing pollutant concentrations. However, there is still a lack of mechanistic understanding of how solid barriers affect pollutant transport, especially under a variety of meteorological conditions. In this study, we utilized the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model to simulate the spatial gradients of SF6 concentrations behind a solid barrier under a variety of atmospheric stability conditions collected during the Near Road Tracer Study (NRTS08). We employed two different CFD models, RANS and LES. A recirculation zone, characterized by strong mixing, forms in the wake of a barrier. It is found that this region is important for accurately predicting pollutant dispersion, but is often insufficiently resolved by the less complex RANS model. The RANS model was found to perform adequately away from the leading edge of the barrier. The LES model, however, performs consistently well at all flow locations. Therefore, the LES model will make a significant improvement compared to the RANS model in regions of strong recirculating flow or edge effects. Our study suggests that advanced simulation tools can potentially provide a variety of numerical experiments that may prove useful for roadway design communities to intelligently design roadways, making effective use of roadside barriers.

  16. Effect of modified atmosphere packaging and storage conditions on quality characteristics of cucumber.

    PubMed

    Manjunatha, M; Anurag, Rahul K

    2014-11-01

    Cucumbers (Cucumis sativus L.) stored in perforated modified atmosphere packaging (MAP) under cold room (4 ± 1 °C and 90 ± 2 % RH) and ambient condition (23-26 °C and 63-66 % RH) were evaluated for firmness, weight loss (WL), colour, chilling injury and sensory characteristics. The firmness of cucumbers was decreased to 0.333 and 0.326 N on 6th and 12th day of storage, respectively from initial value of 0.38 N. After 12 days of storage, the WL was in the range of 1.62-12.89 % whereas the cucumber stored under MAP having 2 perforations at 4 ± 1 °C and 90 ± 2 % RH recorded least WL of 1.62 %. The minimum change in colour (Hunter L, a and b values) was observed in the cucumber samples stored at cold room condition. The increase in 'b' values (yellowness) was more in the sample stored at ambient condition with unsealed sample registered highest 'b' values (35.82). On 12th day of storage, sensory quality evaluation revealed that samples stored under perforated MAP at 4 ± 1 °C and 90 ± 2 % RH were acceptable in condition with sensory score of 7.1 and 7.5. Chilling injury was severe in sample unsealed (4.4 chilling injury score) and slight to moderate chilling injury was observed in 2 and 4 perforated package samples stored under cold room condition. The study revealed that cucumber can be stored under MAP with 2 perforations at 4 ± 1 °C and 90 ± 2 % RH and ambient condition (23-26 °C and 63-66 % RH) for 12 and 6 days, respectively. PMID:26396348

  17. The effect of cultivation practices on soil - atmosphere carbon cycle under arid climate conditions

    NASA Astrophysics Data System (ADS)

    Lifschitz, David; Sternberg, Marcelo; Bonfil, David; Ben-Dor, Eyal; Eshel, Gil

    2010-05-01

    The soil - atmosphere carbon cycle was studied under arid climate conditions, in relation to crop management. Management included different tillage (Conventional vs. No Tillage, CT vs. NT respectively) and fertilization (nitrogen and phosphorus application vs. unfertilized) practices, in a continuous (winter) wheat field, for two growing seasons (2007-08 and 2008-09). The NT practice was characterized by higher CO2 effluxes than the CT during the growing season. In turn, the CT practice had higher pCO2 throughout the soil profile to a depth of 2m. This could be explained partially by a physical crust formation due to raindrop impact, emerging on the bare soil, mostly in the CT practice. The crust serves as a barrier for gas exchange (soil aeration) and in addition, also reduces rainfall infiltration, and all together harms the growing potential (the NT practice yielded higher plant biomass). Fertilization application had no apparent effect on the CO2 effluxes or the pCO2, but had a significant effect on the yield of the plant biomass. The NT practice had also higher amounts of soil organic Carbon, (SOC) mainly in the surface layer, and soil inorganic Carbon (SIC) to a depth of 2m. This is attributed to straw mulch application for the former and better gas and water conductivity (that initiates carbonate dissolution - precipitation cycles) for the latter, which is a much more dominant factor in arid area soils. The stable carbon isotope analysis (δ13C) values for the total Carbon (TC), SOC and SIC results show that the NT practice generates higher amounts of pedogenic carbonates also, and in general is clearly superior over CT in almost every aspect in the soil - atmosphere C cycle.

  18. Future changes in atmospheric condition for the baiu under RCP scenarios

    NASA Astrophysics Data System (ADS)

    Okada, Y.; Takemi, T.; Ishikawa, H.

    2015-12-01

    This study focuses on atmospheric circulation fields during the baiu in Japan with global warming projection experimental data conducted using a 20-km mesh global atmospheric model (MRI-AGCM3.2) under Representative Concentration Pathways (RCP) scenarios. This model also used 4 different sea surface temperature (SST) initial conditions. Support of this dataset is provided by the Meteorological Research Institute (MRI). The baiu front indicated by the north-south gradient of moist static energy moves northward in present-day climate, whereas this northward shift in future climate simulations is very slow during May and June. In future late baiu season, the baiu front stays in the northern part of Japan even in August. As a result, the rich water vapor is transported around western Japan and the daily precipitation amount will increase in August. This northward shift of baiu front is associated with the westward expansion of the enhanced the North Pacific subtropical high (NPSH) into Japan region. However, the convective activity around northwest Pacific Ocean is inactive and is unlikely to occur convective jump (CJ). These models show that the weak trough exists in upper troposphere around Japan. Therefore, the cold advection stays in the northern part of Japan during June. In July, the front due to the strengthening of the NPSH moves northward, and then it stays until August. This feature is often found between the clustered SSTs, Cluster 2 and 3. The mean field of future August also show the inflow of rich water vapor content to Japan islands. In this model, the extreme rainfall suggested tends to almost increase over the Japan islands during future summer. This work was conducted under the Program for Risk Information on Climate Change supported by the Ministry of Education, Culture, Sports, Science, and Technology-Japan (MEXT).

  19. Asian dust particles converted into aqueous droplets under remote marine atmospheric conditions

    PubMed Central

    Tobo, Yutaka; Zhang, Daizhou; Matsuki, Atsushi; Iwasaka, Yasunobu

    2010-01-01

    The chemical history of dust particles in the atmosphere is crucial for assessing their impact on both the Earth’s climate and ecosystem. So far, a number of studies have shown that, in the vicinity of strong anthropogenic emission sources, Ca-rich dust particles can be converted into aqueous droplets mainly by the reaction with gaseous HNO3 to form Ca(NO3)2. Here we show that other similar processes have the potential to be activated under typical remote marine atmospheric conditions. Based on field measurements at several sites in East Asia and thermodynamic predictions, we examined the possibility for the formation of two highly soluble calcium salts, Ca(NO3)2 and CaCl2, which can deliquesce at low relative humidity. According to the results, the conversion of insoluble CaCO3 to Ca(NO3)2 tends to be dominated over urban and industrialized areas of the Asian continent, where the concentrations of HNO3 exceed those of HCl ([HNO3/HCl] >  ∼ 1). In this regime, CaCl2 is hardly detected from dust particles. However, the generation of CaCl2 becomes detectable around the Japan Islands, where the concentrations of HCl are much higher than those of HNO3 ([HNO3/HCl] <  ∼ 0.3). We suggest that elevated concentrations of HCl in the remote marine boundary layer are sufficient to modify Ca-rich particles in dust storms and can play a more important role in forming a deliquescent layer on the particle surfaces as they are transported toward remote ocean regions. PMID:20921372

  20. Atmospheric synoptic conditions of snow precipitation in East Antarctica using ice core and reanalysis data

    NASA Astrophysics Data System (ADS)

    Scarchilli, Claudio; Ciardini, Virginia; Bonazza, Mattia; Frezzotti, Massimo; Stenni, Barbara

    2014-05-01

    In the framework of the International Partnerships in Ice Core Sciences (IPCS) initiatives the GV7 site (70°41' S - 158°51' E) in East Antarctica was chosen as the new drilling site for the Italian contribution to the understanding of the climatic variability in the last 2000 years (IPICS 2k Array). Water stable isotopes and snow accumulation (SMB) values from a shallow firn core, obtained at GV7 during the 2001-2002 International Trans-Antarctic Scientific Expedition (ITASE) traverse, are analyzed and compared with different meteorological model output in order to characterize the atmospheric synoptic conditions driving precipitation events at the site. On annual basis, ECMWF +24h forecasted snowfalls (SF) seem to well reproduce GV7 SMB values trend for the period from 1980 to 2005. Calculated air mass back-trajectories show that Eastern Indian - Western Pacific oceans represent the main moisture path toward the site during autumn - winter season. Analysis of the ECMWF 500 hPa Geopotential height field (GP500) anomalies shows that atmospheric blocking events developing between 130° E and 150° W at high latitudes drive the GV7 SMB by blocking zonal flow and conveying warm and moist deep air masses from ocean into the continental interior. On inter-annual basis, The SF variability over GV7 region follows the temporal oscillation of the third CEOF mode (CEOF3 10% of the total explained variance) of a combined complex empirical orthogonal function (CEOF) performed over GP500 and SF field. The CEOF3 highlights an oscillating feature, with wavenumber 2, in GP500 field over the Western Pacific-Eastern Indian Oceans and propagating westward. The pattern is deeply correlated with the Indian Dipole Oscillation and ENSO and their associated quasi-stationary Rossby waves propagating from the lower toward the higher latitudes.

  1. Investigation of aromatic compound degradation under atmospheric conditions in the outdoor simulation chamber SAPHIR

    NASA Astrophysics Data System (ADS)

    Nehr, Sascha; Bohn, Birger; Rohrer, Franz; Tillmann, Ralf; Wegener, Robert; Dorn, Hans-Peter; Häseler, Rolf; Brauers, Theo; Wahner, Andreas

    2010-05-01

    Ozone is produced in the lower troposphere by the OH-initiated photooxidation of volatile organic compounds in the presence of NOx. Aromatic hydrocarbons from anthropogenic sources are a major contributor to the OH-reactivity and thus to ozone formation in urban areas [1]. Moreover, their degradation leads to formation of secondary organic aerosol. Aromatic compounds are therefore important trace constituents with regard to air quality. We will present the results of photooxidation experiments which were conducted in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich. The experiments were designed to investigate the degradation mechanisms of benzene and p-xylene, which are among the most abundant aromatics in urban air samples. Benzene and p-xylene were selected because they have high structural symmetry which limits the number of potential isomers of secondary products. The experiments were performed under low-NOx-conditions (≤ 2 ppb). SAPHIR was equipped with instruments for the measurement of the parent aromatics and their major oxidation products, OH radicals, important radical precursors (O3, HONO, HCHO), photolysis frequencies and particulate matter. As shown in previous studies, simulation chamber data from the photooxidation of aromatics cannot be explained satisfactorily with current photochemistry mechanisms. For example the MCMv3.1 tends to overestimate the ozone-concentration and to underestimate the OH-concentration [2]. In this study, we will contrast model calculations with experimental results to check if similar discrepancies can be observed in SAPHIR and how they can be resolved. Based on the results of this preparatory study, further simulation chamber experiments with special emphasis on the radical budget are scheduled in 2010. References: [1] J. G. Calvert, R. Atkinson, K.H. Becker, R.M. Kamens, J.H. Seinfeld, T.J. Wallington, G. Yarwood: The mechanisms of atmospheric oxidation of aromatic hydrocarbons, Oxford University

  2. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    SciTech Connect

    Clegg, Sanuel M; Barefield, James E; Humphries, Seth D; Wiens, Roger C; Vaniman, D. T.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Smrekar, S. E.

    2010-12-13

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  3. Maximum Evaporation Rates of Water Droplets Approaching Obstacles in the Atmosphere Under Icing Conditions

    NASA Technical Reports Server (NTRS)

    Lowell, H. H.

    1953-01-01

    When a closed body or a duct envelope moves through the atmosphere, air pressure and temperature rises occur ahead of the body or, under ram conditions, within the duct. If cloud water droplets are encountered, droplet evaporation will result because of the air-temperature rise and the relative velocity between the droplet and stagnating air. It is shown that the solution of the steady-state psychrometric equation provides evaporation rates which are the maximum possible when droplets are entrained in air moving along stagnation lines under such conditions. Calculations are made for a wide variety of water droplet diameters, ambient conditions, and flight Mach numbers. Droplet diameter, body size, and Mach number effects are found to predominate, whereas wide variation in ambient conditions are of relatively small significance in the determination of evaporation rates. The results are essentially exact for the case of movement of droplets having diameters smaller than about 30 microns along relatively long ducts (length at least several feet) or toward large obstacles (wings), since disequilibrium effects are then of little significance. Mass losses in the case of movement within ducts will often be significant fractions (one-fifth to one-half) of original droplet masses, while very small droplets within ducts will often disappear even though the entraining air is not fully stagnated. Wing-approach evaporation losses will usually be of the order of several percent of original droplet masses. Two numerical examples are given of the determination of local evaporation rates and total mass losses in cases involving cloud droplets approaching circular cylinders along stagnation lines. The cylinders chosen were of 3.95-inch (10.0+ cm) diameter and 39.5-inch 100+ cm) diameter. The smaller is representative of icing-rate measurement cylinders, while with the larger will be associated an air-flow field similar to that ahead of an airfoil having a leading-edge radius

  4. Study of the atmospheric conditions affecting infrared astronomical measurements at White Mountain, California

    NASA Technical Reports Server (NTRS)

    Field, G. B.

    1974-01-01

    Measurements are described of atmospheric conditions affecting astronomical observations at White Mountain, California. Measurements were made at more than 1400 times spaced over more than 170 days at the Summit Laboratory and a small number of days at the Barcroft Laboratory. The recorded quantities were ten micron sky noise and precipitable water vapor, plus wet and dry bulb temperatures, wind speed and direction, brightness of the sky near the sun, fisheye lens photographs of the sky, description of cloud cover and other observable parameters, color photographs of air pollution astronomical seeing, and occasional determinations of the visible light brightness of the night sky. Measurements of some of these parameters have been made for over twenty years at the Barcroft and Crooked Creek Laboratories, and statistical analyses were made of them. These results and interpretations are given. The bulk of the collected data are statistically analyzed, and disposition of the detailed data is described. Most of the data are available in machine readable form. A detailed discussion of the techniques proposed for operation at White Mountain is given, showing how to cope with the mountain and climatic problems.

  5. Possibility of ozone depletion monitoring in conditions of opaque atmosphere using D-dosimeter

    NASA Astrophysics Data System (ADS)

    Terenetskaya, Irina P.

    2002-01-01

    Variations of solar ultraviolet (UV) radiation by clouds and aerosols that have a comparable effect on UVB (280-315 nm) caused by variations in stratospheric ozone hinder accurate detecting mid-latitude UVB trends. In this connection it is desirable to use a UVB dosimeter that has at least two independent parameters, namely, a parameter responding to the integral intensity of UVB radiation and an additional one exclusively sensitive to the short wavelength variations in solar UV spectrum related to ozone depletion. The desired spectral selectivity is intrinsic in D-dosimeter that was recently introduced for an in situ monitoring of vitamin D synthetic capacity of solar UVB radiation. D-dosimeter is based on an in vitro model of vitamin D synthesis. The photoreaction rate (decay of provitamin D and formation of previtamin D) depends upon the integral UV intensity whereas maximum achievable concentration of previtamin D is solely dictated by the spectral position of the short-wave edge of solar spectrum. This makes it possible to reveal ozone depletion under conditions of opaque atmosphere when clouds and aerosols attenuate solar UV flux like a gray filter.

  6. Atmospheric turbulence conditions leading to focused and folded sonic boom wave fronts.

    PubMed

    Piacsek, Andrew A

    2002-01-01

    The propagation and subsequent distortion of sonic booms with rippled wave fronts are investigated theoretically using a nonlinear time-domain finite-difference scheme. This work seeks to validate the rippled wave front approach as a method for explaining the significant effects of turbulence on sonic booms [A. S. Pierce and D. J. Maglieri, J. Acoust. Soc. Am. 51, 702-721 (1971)]. A very simple description of turbulence is employed in which velocity perturbations within a shallow layer of the atmosphere form strings of vortices characterized by their size and speed. Passage of a steady-state plane shock front through such a vortex layer produces a periodically rippled wave front which, for the purposes of the present investigation, serves as the initial condition for a finite-difference propagation scheme. Results show that shock strength and ripple curvature determine whether ensuing propagation leads to wave front folding. High resolution images of the computed full wave field provide insights into the spiked and rounded features seen in sonic booms that have propagated through turbulence. PMID:11837957

  7. Understanding strategies for seed dispersal by wind under contrasting atmospheric conditions

    PubMed Central

    Wright, S. Joseph; Trakhtenbrot, Ana; Bohrer, Gil; Detto, Matteo; Katul, Gabriel G.; Horvitz, Nir; Muller-Landau, Helene C.; Jones, Frank A.; Nathan, Ran

    2008-01-01

    Traits associated with seed dispersal vary tremendously among sympatric wind-dispersed plants. We used two contrasting tropical tree species, seed traps, micrometeorology, and a mechanistic model to evaluate how variation in four key traits affects seed dispersal by wind. The conceptual framework of movement ecology, wherein external factors (wind) interact with internal factors (plant traits) that enable movement and determine when and where movement occurs, fully captures the variable inputs and outputs of wind dispersal models and informs their interpretation. We used model calculations to evaluate the spatial pattern of dispersed seeds for the 16 factorial combinations of four traits. The study species differed dramatically in traits related to the timing of seed release, and a strong species by season interaction affected most aspects of the spatial pattern of dispersed seeds. A rich interplay among plant traits and seasonal differences in atmospheric conditions caused this interaction. Several of the same plant traits are crucial for both seed dispersal and other aspects of life history variation. Observed traits that limit dispersal are likely to be constrained by their life history consequences. PMID:19060189

  8. On cosmic rays flux variations in midlatitudes and their relations to geomagnetic and atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Morozova, Anna; Blanco, Juan Jose; Mendes Ribeiro, Paulo Fernando

    The cosmic rays flux is globally modulated by the solar cycle and shows anti-correlation with the sunspot number. Near to the Earth it is modulated by the solar wind and the Earth's magnetic field. The analysis of the secondary cosmic rays produced when they interact in the low stratosphere allows extracting information about solar wind structures surrounding Earth's orbit, the magnetic field of the Earth and the temperature of the stratosphere. Recently, a new cosmic ray detector, the TRAGALDABAS, composed by RPC (Resistive Plate Chamber) planes, has been developed and installed to go deeper into the understanding of the cosmic rays arriving to the Earth surface. An international collaboration has been organized for keeping the detector operative and for analyzing the data. Here we present the analysis of the cosmic rays flux variations measured by two cosmic rays detectors of different types located in Spain (Castilla-La Mancha Neutron Monitor - CaLMa - in Guadalajara and TRAGALDABAS in Santiago de Compostela) and their comparison to changes both in the geomagnetic field components measured by the Coimbra Geomagnetic Observatory (Portugal) and in the atmospheric conditions (tropo- and stratosphere) measured by Spanish and Portuguese meteorological stations. The study is focused on a number of recent cosmic rays events and pays specific attention to the comparison of the CaLMa series and the preliminary TRAGALDABAS data.

  9. Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States.

    PubMed

    Simkin, Samuel M; Allen, Edith B; Bowman, William D; Clark, Christopher M; Belnap, Jayne; Brooks, Matthew L; Cade, Brian S; Collins, Scott L; Geiser, Linda H; Gilliam, Frank S; Jovan, Sarah E; Pardo, Linda H; Schulz, Bethany K; Stevens, Carly J; Suding, Katharine N; Throop, Heather L; Waller, Donald M

    2016-04-12

    Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg N⋅ha(-1)⋅y(-1), we found a unimodal relationship; richness increased at low deposition levels and decreased above 8.7 and 13.4 kg N⋅ha(-1)⋅y(-1) in open and closed-canopy vegetation, respectively. N deposition exceeded critical loads for loss of plant species richness in 24% of 15,136 sites examined nationwide. There were negative relationships between species richness and N deposition in 36% of 44 community gradients. Vulnerability to N deposition was consistently higher in more acidic soils whereas the moderating roles of temperature and precipitation varied across scales. We demonstrate here that negative relationships between N deposition and species richness are common, albeit not universal, and that fine-scale processes can moderate vegetation responses to N deposition. Our results highlight the importance of contingent factors when estimating ecosystem vulnerability to N deposition and suggest that N deposition is affecting species richness in forested and nonforested systems across much of the continental United States. PMID:27035943

  10. Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States

    USGS Publications Warehouse

    Simkin, Samuel M.; Allen, Edith B.; Bowman, William D.; Clark, Christopher M.; Belnap, Jayne; Brooks, Matthew L.; Cade, Brian S.; Collins, Scott L.; Geiser, Linda H.; Gilliam, Frank S.; Jovan, Sarah E.; Pardo, Linda H.; Schulz, Bethany K.; Stevens, Carly J.; Suding, Katharine N.; Throop, Heather L.; Waller, Donald M.

    2016-01-01

    Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg N⋅ha−1⋅y−1, we found a unimodal relationship; richness increased at low deposition levels and decreased above 8.7 and 13.4 kg N⋅ha−1⋅y−1 in open and closed-canopy vegetation, respectively. N deposition exceeded critical loads for loss of plant species richness in 24% of 15,136 sites examined nationwide. There were negative relationships between species richness and N deposition in 36% of 44 community gradients. Vulnerability to N deposition was consistently higher in more acidic soils whereas the moderating roles of temperature and precipitation varied across scales. We demonstrate here that negative relationships between N deposition and species richness are common, albeit not universal, and that fine-scale processes can moderate vegetation responses to N deposition. Our results highlight the importance of contingent factors when estimating ecosystem vulnerability to N deposition and suggest that N deposition is affecting species richness in forested and nonforested systems across much of the continental United States.

  11. Cloud conditions for low atmospheric electricity during disturbed period after the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Yatagai, Akiyo; Yamauchi, Masatoshi; Ishihara, Masahito; Watanabe, Akira; Murata, Ken T.

    2016-04-01

    The vertical (downward) component of the atmospheric electric field, or potential gradient (PG) under cloud generally reflects the electric charge distribution in the cloud. The PG data at Kakioka, 150 km southwest of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) suggested that this relation can be modified when the radioactive dust was floating in the air, and the exact relation between the weather and this modification could lead to new insight in plasma physics in the wet atmosphere. Unfortunately the detailed weather data was not available above Kakioka (only the precipitation data was available). Therefore, estimation of the cloud condition during March 2011 was strongly needed. We have developed various meteorological information links (http://www.chikyu.ac.jp/akiyo/firis/) and original radar and precipitation data will be released from the page. Here we present various radar images that we have prepared for March 2011. We prepared three-dimensional radar reflectivity of the C-band radar of JMA in every 10 minutes over all Kanto Plain centered at Tokyo and Fukushima prefecture centered at Sendai. We have released images of each altitude (1km interval) for 15th - 16thand 21th March (http://sc-web.nict.go.jp/fukushima/). The vertical structure of the rainfall is almost the same at 4km with the surface and sporadic high precipitation is observed at 6 km height for 15-16th. While, generally precipitation pattern that is similar to the surface is observed at 5km height on 21th. On the other hand, an X-band radar centered at Fukushima university is also used to know more localized raindrop patterns at zenith angle of 4 degree. We prepared 10-minutes/120m mesh precipitation patterns for March 15th, 16th, 17th, 18th, 20th, 21th, 22th and 23th. Quantitative estimate is difficult from this X-band radar, but localized structure, especially for the rain-band along Nakadori (middle valley in Fukushima prefecture), that is considered to determine the highly

  12. Undergraduate Research at a Minority University: Studying the Atmospheric Conditions in Urban vs. Rural Areas

    NASA Astrophysics Data System (ADS)

    Morris, P. A.; Green Garcia, A.; Hromis, A.; Vaquiz, E.; Wright, J. M.; Austin, S. A.; Johnson, L. P.; Musselwhite, D.; Walter, D.

    2009-12-01

    A grant from the National Science Foundation (NFS) funded a three year atmospheric science program known as the Minority University Consortium for Earth and Space Science (MUCESS) that supports undergraduate research programs devoted to studying ozone (O3) profiles. MUCESS institutions are represented by the University of Houston-Downtown (UHD), Medgar Evers College of the City University of New York (MEC), and South Carolina State University (SCSU). The primary strength of the program lies in the fact that it provides a venue for students from the participating minority institutions to build bridges of dialogue and strengthen research capabilities. A secondary strength of MUCESS is that the collaborative institutions are widely separated geographically but they have excellent communications and the ability to coordinate launches and support annual workshops. MUCESS supported a series of ozonesonde launches from multiple sites between April and July 2009. Both urban and rural sites were chosen based on their proximity to the three participating minority universities. Balloon and ozone monitoring technology facilitated data acquisition from cost-effective, environmentally friendly, and reproducible experiments. Payloads consisting of an ozonesonde, Vaisala® radiosonde, and GPS receiver provided information on dynamic atmospheric conditions that exist from ground level through altitudes up to one hundred thousand feet. Preparations for the collaborative launch included an initial calibration phase where identical calibration procedures prepared all three payloads. This calibration phase was performed five to seven days in advance of the launch. An additional calibration was performed the day of launch to verify communications between in-flight and ground radio transmitter and receiver, as well as to validate partial pressure and O3 concentration output from the ozonesonde. Each payload was tethered to a 600 gram weather balloon which was then carried up to the

  13. An ENSO prediction approach based on ocean conditions and ocean-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Tseng, Yu-heng; Hu, Zeng-Zhen; Ding, Ruiqiang; Chen, Han-ching

    2016-05-01

    A simple statistical model for the El Niño-Southern Oscillation (ENSO) prediction is derived based on the evolution of the ocean heat condition and the oceanic Kelvin wave propagation associated with westerly wind events (WWEs) and easterly wind surges (EWSs) in the tropical Pacific. The multivariate linear regression model solely relies on the pentad thermocline depth anomaly evolution in 25 days along with the zonal surface wind modulation. It successfully hindcasts all ENSOs except for the 2000/01 La Niña, using the pentad (or monthly) mean tropical atmosphere ocean array data since 1994 with an averaged skill (measured by anomaly correlation) of 0.62 (or 0.67) with a 6-month lead. The exception is mainly due to the long-lasting cold sea surface temperature anomalies in the subtropics resulting from the strong 1998/99 La Niña, even though the tropical warm water volume (WWV) had rebounded and turned phases after 2000. We also note that the hindcast skill is comparable using pentad or monthly mean NCEP global ocean data assimilation system data for the same time period. The hindcast skill of the proposed statistical model is better than that based on the WWV index in terms of the monthly correlation, normalized RMSEs and ENSO occurrences, which suggest that including the evolution of the subsurface ocean temperature anomaly and the WWEs/EWSs in the central tropical Pacific can enhance the ability to predict ENSO. The hindcast skill is also comparable to the predictions using other dynamical and statistical models, indicating that these processes are the keys to ENSO development. The dynamics behind the statistical model are consistent with the physical processes of ENSO development as follows: the tropical WWV resulting from the interannually-varying meridional subtropical cell transport provides a sufficient heat source. When the seasonal phase lock of ocean-atmosphere coupling triggers the positive (negative) zonal wind anomaly in boreal summer and fall, an

  14. Springtime melt onset on arctic sea ice from satellite observations and related atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Bliss, Angela C.

    The timing of snowmelt onset (MO) on Arctic sea ice derived from passive microwave satellite data is examined by determining the melting area (in km 2) on a daily basis for the spring and summer melt season months over the 1979 -- 2012 data record. The date of MO on Arctic sea ice has important implications for the amount of total solar energy absorbed by the ice-ocean system in a given year. Increasingly early mean MO dates have been recorded over the 34-year data record. Statistically significant trends indicate that MO is occurring 6.6 days decade-1 earlier in the year over all Arctic sea ice extent. Larger trends exist in sub-regions of the Arctic Ocean including the Barents, Kara, Laptev, East Siberian, Chukchi, and Beaufort Seas and in the Central Arctic region. The Bering Sea is the only sub-region of the Arctic that has a positive trend in mean MO date indicating that melting is occurring later in the year. Temporal and spatial variability in melting events are examined in the time series of daily MO areas via the identification of several types of melting events. These melting events are characterized based on the magnitude of area melted and duration of the event. Daily maps of MO during melting events are compared with the atmospheric conditions from reanalysis data to investigate the nature of spatial variability in melting area. The occurrence of transient cyclones tends to produce large, contiguous areas of melting on sea ice located in the warm sector of the cyclone. By contrast, high pressure and attendant clear sky conditions tend to produce sporadic, discontinuous areas of melting area. Interannual variability in daily MO area is assessed using an annual accumulation of daily MO area for each melt season. Trends in mean MO dates are evident in the annual accumulations, however, regional variability is high and outlier events can occur. This work illustrates the need for a better understanding of the synoptic weather conditions leading to specific

  15. Numerical simulation of the middle atmosphere chemical composition and temperature under changing solar conditions

    NASA Technical Reports Server (NTRS)

    Zadorozhny, A. M.; Dyominov, I. G.; Tuchkov, G. A.

    1989-01-01

    There are given results of the numerical experiments on modelling the influence of solar activity on chemical composition and temperature of the middle atmosphere. The consideration is made for peculiarities of solar activity impact under different values of antropogenic pollution of the atmosphere with chlorofluorocarbons and other stuff.

  16. Estimating spatial veriability in atmospheric properties over remotely sensed land-surface conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper investigates the spatial relationships between land-surface fluxes and near-surface atmospheric properties (AP), and the potential errors in flux estimation due to homogeneous atmospheric inputs over heterogeneous landscapes. A Large Eddy Simulation (LES) model is coupled to a surface ene...

  17. Autofluorescence of atmospheric bioaerosols - Biological standard particles and the influence of environmental conditions

    NASA Astrophysics Data System (ADS)

    Pöhlker, Christopher; Huffman, J. Alex; Förster, Jan-David; Pöschl, Ulrich

    2013-04-01

    standard bioparticles (pollen, fungal spores, and bacteria) as well as atmospherically relevant chemical substances. We addressed the sensitivity and selectivity of autofluorescence based online techniques. Moreover, we investigated the influence of environmental conditions, such as relative humidity and oxidizing agents in the atmosphere, on the autofluorescence signature of standard bioparticles. Our results will support the molecular understanding and quantitative interpretation of data obtained by real-time FBAP instrumentation [5,6]. [1] Elbert, W., Taylor, P. E., Andreae, M. O., & Pöschl, U. (2007). Atmos. Chem. Phys., 7, 4569-4588. [2] Huffman, J. A., Treutlein, B., & Pöschl, U. (2010). Atmos. Chem. Phys., 10, 3215-3233. [3] Pöschl, U., et al. (2010). Science, 329, 1513-1516. [4] Lakowicz, J., Principles of fluorescence spectroscopy, Plenum publishers, New York, 1999. [5] Pöhlker, C., Huffman, J. A., & Pöschl, U., (2012). Atmos. Meas. Tech., 5, 37-71. [6] Pöhlker, C., Huffman, J. A., Förster J.-D., & Pöschl, U., (2012) in preparation.

  18. Characterization of Multi-Scale Atmospheric Conditions Associated with Extreme Precipitation in the Transverse Ranges of Southern California

    NASA Astrophysics Data System (ADS)

    Oakley, N.; Kaplan, M.; Ralph, F. M.

    2015-12-01

    The east-west oriented Transverse Ranges of Southern California have historically experienced shallow landslides and debris flows that threaten life and property. Steep topography, soil composition, and frequent wildfires make this area susceptible to mass wasting. Extreme rainfall often acts as a trigger for these events. This work characterizes atmospheric conditions at multiple scales during extreme (>99th percentile) 1-day precipitation events in the major sub-ranges of the Transverse Ranges. Totals from these 1-day events generally exceed the established sub-daily intensity-duration thresholds for shallow landslides and debris flows in this region. Daily extreme precipitation values are derived from both gridded and station-based datasets over the period 1958-2014. For each major sub-range, extreme events are clustered by atmospheric feature and direction of moisture transport. A composite analysis of synoptic conditions is produced for each cluster to create a conceptual model of atmospheric conditions favoring extreme precipitation. The vertical structure of the atmosphere during these extreme events is also examined using observed and modeled soundings. Preliminary results show two atmospheric features to be of importance: 1) closed and cutoff low-pressure systems, areas of counter-clockwise circulation that can produce southerly flow orthogonal to the Transverse Range ridge axes; and 2) atmospheric rivers that transport large quantities of water vapor into the region. In some cases, the closed lows and atmospheric rivers work in concert with each other to produce extreme precipitation. Additionally, there is a notable east-west dipole of precipitation totals during some extreme events between the San Gabriel and Santa Ynez Mountains where extreme values are observed in one range and not the other. The cause of this relationship is explored. The results of this work can help forecasters and emergency responders determine the likelihood that an event will

  19. Atmosphere

    NASA Astrophysics Data System (ADS)

    Ghosh, D.; Mitra, S. K.

    2014-05-01

    This paper investigates the high-temperature corrosion behavior of microstructurally different regions of the weldment of 9 Cr-1 Mo steel used in thermal power plant boiler in SO2 + O2 environment. The weldment is produced by tungsten inert gas welding method, and the different regions of the weldment (weld metal, heat-affected zone, and base metal) are exposed in SO2 + O2 (ratio 2:1) environment at 973 K for 120 h. The reaction kinetics and corrosion growth rate of different regions of weldment in isothermal condition are evaluated. The post corroded scales of the different specimens are studied in SEM, EDS, and XRD. The results indicate that the weld metal shows higher corrosion rate followed by HAZ and base metal. The higher rate of corrosion of weldmetal is mainly attributed to the least protective inner scale of Cr2O3 with minimum Cr Content. This is due to the formation of delta ferrite, which leads to the precipitation of the Cr-based secondary phases and depletes the free Cr from the matrix. The thermal cycles during welding at high temperature are favorable for the formation of delta ferrite. On the other hand, in absence of delta ferrite, the base metal and HAZ regions of the weldment show lower corrosion rate than weld metal. The difference in corrosion rate in the three regions of the weldment is supplemented by post-corroded scale characterizations.

  20. Instrument intercomparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Thalman, R.; Baeza-Romero, M. T.; Ball, S. M.; Borrás, E.; Daniels, M. J. S.; Goodall, I. C. A.; Henry, S. B.; Karl, T.; Keutsch, F. N.; Kim, S.; Mak, J.; Monks, P. S.; Muñoz, A.; Orlando, J.; Peppe, S.; Rickard, A. R.; Ródenas, M.; Sánchez, P.; Seco, R.; Su, L.; Tyndall, G.; Vázquez, M.; Vera, T.; Waxman, E.; Volkamer, R.

    2015-04-01

    The α-dicarbonyl compounds glyoxal (CHOCHO) and methyl glyoxal (CH3C(O)CHO) are produced in the atmosphere by the oxidation of hydrocarbons and emitted directly from pyrogenic sources. Measurements of ambient concentrations inform about the rate of hydrocarbon oxidation, oxidative capacity, and secondary organic aerosol (SOA) formation. We present results from a comprehensive instrument comparison effort at two simulation chamber facilities in the US and Europe that included nine instruments, and seven different measurement techniques: broadband cavity enhanced absorption spectroscopy (BBCEAS), cavity-enhanced differential optical absorption spectroscopy (CE-DOAS), white-cell DOAS, Fourier transform infrared spectroscopy (FTIR, two separate instruments), laser-induced phosphorescence (LIP), solid-phase micro extraction (SPME), and proton transfer reaction mass spectrometry (PTR-ToF-MS, two separate instruments; for methyl glyoxal only because no significant response was observed for glyoxal). Experiments at the National Center for Atmospheric Research (NCAR) compare three independent sources of calibration as a function of temperature (293-330 K). Calibrations from absorption cross-section spectra at UV-visible and IR wavelengths are found to agree within 2% for glyoxal, and 4% for methyl glyoxal at all temperatures; further calibrations based on ion-molecule rate constant calculations agreed within 5% for methyl glyoxal at all temperatures. At the European Photoreactor (EUPHORE) all measurements are calibrated from the same UV-visible spectra (either directly or indirectly), thus minimizing potential systematic bias. We find excellent linearity under idealized conditions (pure glyoxal or methyl glyoxal, R2 > 0.96), and in complex gas mixtures characteristic of dry photochemical smog systems (o-xylene/NOx and isoprene/NOx, R2 > 0.95; R2 ∼ 0.65 for offline SPME measurements of methyl glyoxal). The correlations are more variable in humid ambient air mixtures (RH

  1. Remote Raman - Laser Induced Breakdown Spectroscopy (LIBS) Geochemical Investigation under Venus Atmospheric Conditions

    NASA Astrophysics Data System (ADS)

    Clegg, S. M.; Barefield, J. E.; Humphries, S.; Wiens, R. C.; Vaniman, D. T.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Smrekar, S. E.

    2010-12-01

    The extreme Venus surface temperatures (~740 K) and atmospheric pressures (~93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. [1] and Sharma et al. [2] demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic [3] with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachy-andesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  2. Instrument inter-comparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Thalman, R.; Baeza-Romero, M. T.; Ball, S. M.; Borrás, E.; Daniels, M. J. S.; Goodall, I. C. A.; Henry, S. B.; Karl, T.; Keutsch, F. N.; Kim, S.; Mak, J.; Monks, P. S.; Muñoz, A.; Orlando, J.; Peppe, S.; Rickard, A. R.; Ródenas, M.; Sánchez, P.; Seco, R.; Su, L.; Tyndall, G.; Vázquez, M.; Vera, T.; Waxman, E.; Volkamer, R.

    2014-08-01

    The α-dicarbonyl compounds glyoxal (CHOCHO) and methyl glyoxal (CH3C(O)CHO) are produced in the atmosphere by the oxidation of hydrocarbons, and emitted directly from pyrogenic sources. Measurements of ambient concentrations inform about the rate of hydrocarbon oxidation, oxidative capacity, and secondary organic aerosol (SOA) formation. We present results from a comprehensive instrument comparison effort at 2 simulation chamber facilities in the US and Europe that included 9 instruments, and 7 different measurement techniques: Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS), Cavity Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS), White-cell DOAS, Fourier Transform Infra-Red Spectroscopy (FTIR, two separate instruments), Laser Induced Phosphoresence (LIP), Solid Phase Micro Extraction (SPME), and Proton Transfer Reaction Mass Spectrometry (PTR-ToF-MS, two separate instruments; only methyl glyoxal as no significant response was observed for glyoxal). Experiments at the National Center for Atmospheric Research (NCAR) compare 3 independent sources of calibration as a function of temperature (293 K to 330 K). Calibrations from absorption cross-section spectra at UV-visible and IR wavelengths are found to agree within 2% for glyoxal, and 4% for methyl glyoxal at all temperatures; further calibrations based on ion-molecule rate constant calculations agreed within 5% for methyl glyoxal at all temperatures. At the EUropean PHOtoREactor (EUPHORE) all measurements are calibrated from the same UV-visible spectra (either directly or indirectly), thus minimizing potential systematic bias. We find excellent linearity under idealized conditions (pure glyoxal or methyl glyoxal, R2 > 0.96), and in complex gas mixtures characteristic of dry photochemical smog systems (o-xylene/NOx and isoprene/NOx, R2 > 0.95; R2 ~ 0.65 for offline SPME measurements of methyl glyoxal). The correlations are more variable in humid ambient air mixtures (RH > 45%) for methyl

  3. Atmospheric conditions associated with extreme fire activity in the Western Mediterranean region.

    PubMed

    Amraoui, Malik; Pereira, Mário G; DaCamara, Carlos C; Calado, Teresa J

    2015-08-15

    Active fire information provided by TERRA and AQUA instruments on-board sun-synchronous polar MODIS platform is used to describe fire activity in the Western Mediterranean and to identify and characterize the synoptic patterns of several meteorological fields associated with the occurrence of extreme fire activity episodes (EEs). The spatial distribution of the fire pixels during the period of 2003-2012 leads to the identification of two most affected sub-regions, namely the Northern and Western parts of the Iberian Peninsula (NWIP) and Northern Africa (NAFR). The temporal distribution of the fire pixels in these two sub-regions is characterized by: (i) high and non-concurrent inter- and intra-annual variability with maximum values during the summer of 2003 and 2005 in NWIP and 2007 and 2012 in NAFR; and, (ii) high intra-annual variability dominated by a prominent annual cycle with a main peak centred in August in both sub-regions and a less pronounced secondary peak in March only evident in NWIP region. The 34 EEs identified were grouped according to the location, period of occurrence and spatial configuration of the associated synoptic patterns into 3 clusters (NWIP-summer, NWIP-winter and NAFR-summer). Results from the composite analysis reveal similar fire weather conditions (statistically significant positive anomalies of air temperature and negative anomalies of air relative humidity) but associated with different circulation patterns at lower and mid-levels of the atmosphere associated with the occurrence of EEs in each cluster of the Western Mediterranean region. PMID:25889542

  4. Forest biomass estimation with hemispherical photography for multiple forest types and various atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Clark, Joshua Andrew

    The importance of accurately identifying inventories of domestic energy, including forest biomass, has increasingly become a priority of the US government and its citizens as the cost of fossil fuels has risen. It is useful to identify which of these resources can be processed and transported at the lowest cost for both private and public landowners. Accurate spatial inventories of forest biomass can help landowners allocate resources to maximize forest biomass utilization and provide information regarding current forest health (e.g., forest fire potential, insect susceptibility, wildlife habitat range). This research has indicated that hemispherical photography (HP) may be an accurate and low cost sensing technique for forest biomass measurements. In this dissertation: (1) It is shown that HP gap fraction measurements and both above ground biomass and crown biomass have a linear relationship. (2) It is demonstrated that careful manipulation of images improves gap fraction estimates, even under unfavorable atmospheric conditions. (3) It is shown that estimates of Leaf Area Index (LAI), based on transformations of gap fraction measurements, are the best estimator for both above ground forest biomass and crown biomass. (4) It is shown that many factors negatively influence the utility of HP for biomass estimation. (5) It is shown that biomass of forests stands with regular spacing is not modeled well using HP. As researchers continue to explore different methods for forest biomass estimation, HP is likely to remain as a viable technique, especially if LAI can be accurately estimated. However, other methods should be compared with HP, particularly for stands where LAI is poorly estimated by HP.

  5. Optical methods for research of uranium hexafluoride under conditions imitating the atmosphere

    NASA Astrophysics Data System (ADS)

    Gerin, I. I.; Penin, S. T.; Chistyakova, L. K.

    2006-02-01

    Capabilities of optical methods in real-time monitoring of uranium hexafluoride and products of its hydrolysis in the air over the production areas have been studied experimentally in the process of hydrolysis of uranium hexafluoride under controlled conditions imitating the atmosphere. The scattering and absorption coefficients were used to study the process of formation and kinetics of aerosols at interaction of UF 6 with water vapor. It has been shown that time of aerosol formation is mostly determined by time of the hydrolysis, and the lifetime of aerosols is determined by diffusion and convective processes, as well as coagulation. At low concentrations of the parent material the effect of coagulation on the process of aerosol formation is insignificant because of low collision probability of particles. When initial concentration of UF 6 (up to 20 g×m -3) increases hydrolysis occurs faster, and particles are generated during minutes and less. At tenfold excess over the H II0, concentration the intense (active) volume hydrolysis of uranium hexafluoride occurs with formation of aerosols even at the low concentration of UF 6, and this hydrolysis terminates within first 20 min. At lower concentrations of initial substances (~25 μg×m -3), the process of intense hydrolysis proceeds slower and generation of aerosol has no pronounced time interval. It should be emphasized that termination of the intense hydrolysis does not mean complete termination of the reaction that indicate presence of a "penetrative fraction" of UF 6, which continues to react with H II0 and hydrolysis products more than hour. The experiments showed that optical methods allow rather reliable detection of low concentrations of radioactive and toxic admixtures at UF 6 hydrolysis at the level exceeding the MPC, and the equipment based on these methods is capable of providing the reliable monitoring of pre-emergency situations; in addition, this equipment is relatively cheap and convenient in use.

  6. February 2003 marine atmospheric conditions and the bora over the northern Adriatic

    USGS Publications Warehouse

    Dorman, C.E.; Carniel, S.; Cavaleri, L.; Sclavo, M.; Chiggiato, J.; Doyle, J.; Haack, T.; Pullen, J.; Grbec, B.; Vilibic, I.; Janekovic, I.; Lee, C.; Malacic, V.; Orlic, M.; Paschini, E.; Russo, A.; Signell, R.P.

    2007-01-01

    A winter oceanographic field experiment provided an opportunity to examine the atmospheric marine conditions over the northern Adriatic. Mean February winds are from a northeasterly direction over most of the Adriatic and a more northerly direction along the western coast. Wind speeds are fastest in jets over the NE coast during bora events and weakest in the mid-northwestern Adriatic. Diurnal air temperature cycles are smallest on the NE coast and largest in the midwestern Adriatic. The maximum sea-air difference is +10??C on the eastern coast and near zero on the midwestern Adriatic. Boras are northeasterly (from) wind events that sweep off Croatia and Slovenia, bringing slightly colder and drier air over the northern Adriatic. The main bora season is December to March. Winter 2002-2003 was normal for bora events. Synoptic-scale temporal variations are correlated over the northern Adriatic. Fastest Bora winds and highest wind stress over the northern Adriatic is concentrated in four topographically controlled jets. The strongest is the Senj Jet, while the Trieste Jet extends across the entire northern Adriatic. Between each two jets is a weak wind zone. The greatest mean net heat loss is in bora jets in the NE Adriatic, where it was -438 W m-2 and is weakest in the midwestern northern Adriatic, where it was near zero. Wind stress is concentrated over the NE half of Adriatic in four bora jets, while wind stress is weak in the NW Adriatic. There is significant variation in wind stress mean and standard deviation structure over the northern Adriatic with each bora event. Copyright 2006 by the American Geophysical Union.

  7. Variation of atmospheric air pollution under conditions of rapid economic change—Estonia 1994-1999

    NASA Astrophysics Data System (ADS)

    Kimmel, V.; Tammet, H.; Truuts, T.

    Estonia is an example of a country with economy in transition whose atmospheric air pollution has been remarkably influenced by economic changes. During the period of 1994-1999 GDP increased by one-fourth, while agricultural production, electricity and heat production dropped by one-sixths during the studied period. These processes are reflected in the quantity of emissions and structure of air pollution. The study is based on the measurements of concentrations of pollutants at six Estonian Euroairnet monitoring stations—at three sites in the capital city and at three sites in remote areas. The pollutants concerned are the first-priority pollutants in the European Union legislation—nitrogen oxides, SO 2, O 3, particulate matter, and additionally CO. The study reveals that concentrations of gaseous pollutants in Estonia remain within the EU limit values except for ozone in remote areas. The main trend during the studied period was a significant, up to several times, decrease in concentrations of SO 2 and CO while the decrease of nitrogen oxides was less remarkable. The paper propose ratio of NO x/SO 2 as an index describing increasing transport loads and drop in use of sulphur-rich fuels—thus of structure of economy. The annual variation of pollutants is explained by seasonal variations of anthropogenic activity in conditions where local fuels are widely used for heating during winter. Air pollution in Estonian rural stations mostly originated from transboundary fluxes. The 1-3 day delay of the weekly minimum of pollutant concentrations and the wind roses allow to conclude that essential part of pollutants is imported from West Europe.

  8. Global atmospheric sulfur budget under volcanically quiescent conditions: Aerosol-chemistry-climate model predictions and validation

    NASA Astrophysics Data System (ADS)

    Sheng, Jian-Xiong; Weisenstein, Debra K.; Luo, Bei-Ping; Rozanov, Eugene; Stenke, Andrea; Anet, Julien; Bingemer, Heinz; Peter, Thomas

    2015-01-01

    The global atmospheric sulfur budget and its emission dependence have been investigated using the coupled aerosol-chemistry-climate model SOCOL-AER. The aerosol module comprises gaseous and aqueous sulfur chemistry and comprehensive microphysics. The particle distribution is resolved by 40 size bins spanning radii from 0.39 nm to 3.2 μm, including size-dependent particle composition. Aerosol radiative properties required by the climate model are calculated online from the aerosol module. The model successfully reproduces main features of stratospheric aerosols under nonvolcanic conditions, including aerosol extinctions compared to Stratospheric Aerosol and Gas Experiment II (SAGE II) and Halogen Occultation Experiment, and size distributions compared to in situ measurements. The calculated stratospheric aerosol burden is 109 Gg of sulfur, matching the SAGE II-based estimate (112 Gg). In terms of fluxes through the tropopause, the stratospheric aerosol layer is due to about 43% primary tropospheric aerosol, 28% SO2, 23% carbonyl sulfide (OCS), 4% H2S, and 2% dimethyl sulfide (DMS). Turning off emissions of the short-lived species SO2, H2S, and DMS shows that OCS alone still establishes about 56% of the original stratospheric aerosol burden. Further sensitivity simulations reveal that anticipated increases in anthropogenic SO2 emissions in China and India have a larger influence on stratospheric aerosols than the same increase in Western Europe or the U.S., due to deep convection in the western Pacific region. However, even a doubling of Chinese and Indian emissions is predicted to increase the stratospheric background aerosol burden only by 9%. In contrast, small to moderate volcanic eruptions, such as that of Nabro in 2011, may easily double the stratospheric aerosol loading.

  9. Reliability of Undergraduate Student in a Research on the Relations between Behavior and Days of the Week or Atmospheric Conditions.

    ERIC Educational Resources Information Center

    Vachon, Jean

    The influence of atmospheric conditions and the day of the week on school children's behavior was investigated by undergraduates. The college students were told either that their participation in the research was compulsory and would be graded, or that their participation was voluntary and ungraded. Fifty teachers observed their pupils' behavior…

  10. CANOPY CONDUCTANCE OF PINUS TAEDA, LIQUIDAMBAR STYRACIFLUA AND QUERCUS PHELLOS UNDER VARYING ATMOSPHERIC AND SOIL WATER CONDITION

    EPA Science Inventory

    Sap flow, and atmospheric and soil water data were collected in closed-top chambers under conditions of high soil water potential for saplings of Liquidambar styraciflua L., Quercus phellos L., and Pinus taeda L., three co-occurring species in the southeastern USA. Responses of c...

  11. [Concentration distribution of metal elements in atmospheric aerosol under different weather conditions in Qingdao Coastal Region].

    PubMed

    Chen, Xiao-Jing; Qi, Jian-Hua; Liu, Ning; Zhang, Xiang-Yu; Shen, Heng-Qing; Liu, Ming-Xu

    2014-10-01

    To know the influence of different weather conditions on the concentration of metal elements in aerosols in the coastal region, total suspended particles (TSP) samples were collected from April to May 2012, and August 2012 to March 2013 in the Qingdao coastal region, and common trace metals were analyzed by using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The results showed that Al, Ca, Fe, Na, K and Mg were the dominant metal elements in TSP, and the sum of the six elements accounted for 94.2% of the sum of all metals. TSP and metal elements had significant monthly variations, Fe, Al, K, Ca, Mg, Zn, Ba, Mn, Ti, Sr and Li had the highest concentration in November and January, while Be, Sc, Co, Ni and Cr showed the highest value in January. Na had the highest concentration in August, November and February, and the lowest in December. Pb had the highest concentration in January and February, and the lowest in August and December. Enrichment factors indicated that Be, Co, Al, Ca, Fe, K, Mg, Mn, Sr and Ti were mainly affected by natural sources; Li, Cr, Ni, Zn, Ba and Na were affected by natural sources and part of anthropogenic sources; Pb was mainly from anthropogenic sources. Different weather conditions had great impact on TSP and metal elements concentrations, all the measured metals had the highest concentrations in smog except Ti. Compared with the sunny day, the concentration of atmospheric particulate Ti decreased, while the other elements increased by 1 to 4 times in smog. Li, Be, Cr, Ni, Al, Fe, Mg and Mn had little variation in concentration in foggy day, and the concentration of Pb and Na increased considerably. The concentration of Co, Ca and Ti reduced obviously in fog. Except for Cr, Co and Ti, the other elements increased by 1 to 3 times in haze. Most of the elements had the minimal enrichment factors in sunny day, while the other had the maximal enrichment factor in

  12. 'Scarlett Spur Red Delicious' apple volatile production accompanying physiological disorder development during low pO2 controlled atmosphere storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apple (Malus domestica Borkh.) fruit volatile production is regulated by a variety of factors including storage conditions. Although controlled atmosphere (CA) technology extends apple fruit storage life, improper storage conditions can adversely affect volatile production and increase the risk of ...

  13. Atmospheric aerosols in Amazonia and land use change: from natural biogenic to biomass burning conditions.

    PubMed

    Artaxo, Paulo; Rizzo, Luciana V; Brito, Joel F; Barbosa, Henrique M J; Arana, Andrea; Sena, Elisa T; Cirino, Glauber G; Bastos, Wanderlei; Martin, Scot T; Andreae, Meinrat O

    2013-01-01

    fine mode aerosol during the dry season in this region. Aerosol light scattering and absorption coefficients at the TT34 site were low during the wet season, increasing by a factor of 5, approximately, in the dry season due to long range transport of biomass burning aerosols reaching the forest site in the dry season. Aerosol single scattering albedo (SSA) ranged from 0.84 in the wet season up to 0.91 in the dry. At the PVH site, aerosol scattering coefficients were 3-5 times higher in comparison to the TT34 site, an indication of strong regional background pollution, even in the wet season. Aerosol absorption coefficients at PVH were about 1.4 times higher than at the forest site. Ground-based SSA at PVH was around 0.92 year round, showing the dominance of scattering aerosol particles over absorption, even for biomass burning aerosols. Remote sensing observations from six AERONET sites and from MODIS since 1999, provide a regional and temporal overview. Aerosol Optical Depth (AOD) at 550 nm of less than 0.1 is characteristic of natural conditions over Amazonia. At the perturbed PVH site, AOD550 values greater than 4 were frequently observed in the dry season. Combined analysis of MODIS and CERES showed that the mean direct radiative forcing of aerosols at the top of the atmosphere (TOA) during the biomass burning season was -5.6 +/- 1.7 W m(-2), averaged over whole Amazon Basin. For high AOD (larger than 1) the maximum daily direct aerosol radiative forcing at the TOA was as high as -20 W m(-2) locally. This change in the radiation balance caused increases in the diffuse radiation flux, with an increase of Net Ecosystem Exchange (NEE) of 18-29% for high AOD. From this analysis, it is clear that land use change in Amazonia shows alterations of many atmospheric properties, and these changes are affecting the functioning of the Amazonian ecosystem in significant ways. PMID:24601004

  14. EFFECTS OF ELEVATED ATMOSPHERIC CO2 ON WATER CHEMISTRY AND MOSQUITO (DIPTERA: CULICIDAE) GROWTH UNDER COMPETITIVE CONDITIONS IN CONTAINER HABITATS

    PubMed Central

    Alto, Barry W.; Yanoviak, Stephen P.; Lounibos, L. Philip; Drake, Bert G.

    2012-01-01

    We investigated the direct and indirect effects of elevated atmospheric CO2 on freshwater container habitats and their larval mosquito occupants. We predicted that a doubling of atmospheric CO2 would (1) alter the chemical properties of water in this system, (2) slow degradation of leaf litter, and (3) decrease larval growth of Aedes albopictus (Skuse) mosquitoes raised on that litter under competitive conditions. Effects of elevated CO2 on water quality parameters were not detected, but the presence of leaf litter significantly reduced pH and dissolved oxygen relative to water-filled containers without litter. Degradation rates of oak leaf litter from plants grown under elevated CO2 atmospheres did not differ from breakdown rates of litter from ambient CO2 conditions. Litter from plants grown in an elevated CO2 atmospheres did not influence mosquito population growth, but mosquito production decreased significantly with increasing larval density. Differences among mosquito density treatments influenced survivorship most strongly among male Ae. albopictus and time to emergence most strongly among females, suggesting fundamental sex-determined differences in response to competition. Results of this and other studies indicate that direct and indirect effects of doubled atmospheric CO2 are minimal in artificial containers with freshwater. PMID:22661767

  15. A new model for atmospheric radiation under clear sky condition at various altitudes

    NASA Astrophysics Data System (ADS)

    Dai, Qiumin; Fang, Xiande

    2014-09-01

    Atmospheric radiation is one of the major factors that dominate the thermal behaviors of aerostats. A high-performance model is needed to evaluate the atmospheric radiation. Based on the atmospheric radiation database containing 24,862 data points compiled from 7 stations with the elevation from sea level to 2373 m and the reference code MODTRAN, a new atmospheric radiation model is proposed using regression and optimization software. It has excellent prediction accuracy with the coefficient of determination of 0.94, the root mean square error of 15.1 W/m2, and the mean absolute percentage error of 4.13% for the database. Comparison with the well-known existing model shows that the new model has the highest prediction accuracy. The new model predictions agree with the MODTRAN calculations at various altitudes very well, and thus it can be used for estimating the thermal performances of a high altitude aerostat.

  16. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1988-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The key activity for this grant year has continued to be laboratory measurements of the microwave and millimeter-wave properties of the simulated atmospheres of the outer planets and their satellites. A Fabry-Perot spectrometer system capable of operation from 32 to 41 GHz was developed. Initially this spectrometer was used to complete laboratory measurements of the 7.5 to 9.3 mm absorption spectrum of ammonia. Laboratory measurements were begun at wavelengths near 3.2 mm, where a large number of observations of the emission from the outer planets were made. A description of this system is presented.

  17. Height of layer of intense turbulent heat exchange under conditions of stable atmospheric stratification

    NASA Astrophysics Data System (ADS)

    Kamardin, A. P.; Nevzorova, I. V.; Odintsov, S. L.

    2015-11-01

    In the work, we consider estimates of the height of layer of intense turbulent heat exchange in stably stratified atmospheric boundary layer, made with the use of meteorological acoustic radar (sodar). Dependence of this height on temperature gradient is analyzed. Current temperature stratification of the atmosphere in the layer with height up to 1 000 m was determined with the help of MTP-5 meteorological temperature profiler.

  18. Remote Laser Induced Breakdown Spectroscopy (LIBS) Geochemical Investigation under Venus Atmospheric Conditions

    NASA Astrophysics Data System (ADS)

    Clegg, S. M.; Barefield, J. E.; Humphries, S.; Wiens, R. C.; Vaniman, D.; Dyar, M. D.; Tucker, J. M.; Sharma, S. K.; Misra, A. K.

    2009-12-01

    The extreme Venus surface temperature (740 K) and atmospheric pressure (93 atm) creates a challenging environment for future lander missions. Scientific investigations capable of Venus geochemical observations must be completed within several hours of landing before the lander is overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. [1] and Sharma et al. [2] have demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with LIBS and demonstrate the quantitative analysis under Venus surface conditions. The LIBS experiment involves focusing a Nd:YAG laser operating at 1064 nm onto the surface of the sample. The laser ablates material from the surface, generating a plasma containing electronically excited atoms, ions and small molecules. Some of this emission is collected with an 89 mm diameter telescope. The light is directed into a Princeton Instruments f/4 0.25 m dispersive spectrometer and recorded with an ICCD detector. The powdered and pelletized samples are placed in a pressure vessel containing supercritical CO2 at 93 atm and at least 423 K and the vessel is placed at least 1.6 m from the telescope and laser. A range of Venus-analog basaltic rock types [3] was chosen for this study to reproduce compositions identified by Soviet Venera and VEGA landers, including several standards: four basalts (BCR-2, BIR-1, GUWBM, JB-2), granite (GBW 07015), andesite (JA-1), carbonate (SARM-40), and Kauai volcanic (KV04-17, KV04-25). We also added a good Venus analog, TAP 04, which is an alkali-rich rock from an olivine minette in the Ayutla volcanic field (Righter and Rosas-Elguera [4]). Our goal was to study samples with a

  19. Atmospheric Downwelling Longwave Radiation during overcast conditions. Simulations and measurements at Girona, Spain.

    NASA Astrophysics Data System (ADS)

    Viúdez, Toni; Calbó, Josep; Abel González, Josep; Jiménez, M. Antonia

    2010-05-01

    Clouds play an important role in the terrestrial radiative budget and therefore in the climate change, given their ability to absorb solar radiation and also to absorb and emit longwave radiation toward the space and the terrestrial surface. The study of longwave radiation in presence of clouds can help us to understand better the climatic system, and recognize their importance in the current climate change. Agreement between measurements and simulations can help us to understand much better their radiative behavior. In this study we show a comparison between measurements and calculations using the unidimensional radiative transfer model SBDART (Ricchiazzi et al, 1998) under overcast sky conditions. Measurements were taken from the radiometric and meteorological station at the University of Girona, Spain (41.96 N 2.83 E 110 m a.s.l.). Downward Longwave Radiation, DLR, was measured using a pyrgeometer CG1 by Kipp & Zonen. To determine the cloud fraction, and subsequently select overcast cases, we used the algorithm APCADA (Dürr and Philipona, 2004) from one year dataset of measurements of DLR, temperature and relative humidity. DLR has a strong dependence on atmospheric vertical profiles (mainly on temperature and water vapor content). Since there are no soundings available at the same site, we used the vertical profile from a gridded analysis (provided by the European Centre for Medium-Range Weather Forecasts,ECMWF). Cloud base height (CBH) was included into calculations by using the measurements taken by a ceilometer CL31 by Vaisala. This CBH was compared with an estimation based on ECMWF profiles, setting the cloud base where the relative humidity is higher than a threshold of 95% (RH95). The effective radius of cloud droplets and liquid water path was fixed from typical values (Stephens, 1978). Three different modeling cases were analyzed, depending on the use of the CBH from the ceilometer or from applying the RH95 threshold in ECMWF profiles, and also

  20. Experimental and computational investigation of supersonic counterflow jet interaction in atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Ivanchenko, Oleksandr

    The flow field generated by the interaction of a converging-diverging nozzle (exit diameter, D=26 mm M=1.5) flow and a choked flow from a minor jet (exit diameter, d=2.6 mm) in a counterflow configuration was investigated. During the tests both the main C-D nozzle and the minor jet stagnation pressures were varied as well as the region of interaction. Investigations were made in the near field, at most about 2D distance, and in the far field, where the repeated patterns of shock waves were eliminated by turbulence. Both nozzles exhausted to the atmospheric pressure conditions. The flow physics was studied using Schlieren imaging techniques, Pitot-tube, conical Mach number probe, Digital Particle Image Velocimetry (DPIV) and acoustic measurement methods. During the experiments in the far field the jets interaction was observed as the minor jet flow penetrates into the main jet flow. The resulting shock structure caused by the minor jet's presence was dependent on the stagnation pressure ratio between the two jets. The penetration length of the minor jet into the main jet was also dependent on the stagnation pressure ratio. In the far field, increasing the minor jet stagnation pressure moved the bow shock forward, towards the main jet exit. In the near field, the minor jet flow penetrates into the main jet flow, and in some cases modified the flow pattern generated by the main jet, revealing a new effect of jet flow interaction that was previously unknown. A correlation function between the flow modes and the jet stagnation pressure ratios was experimentally determined. Additionally the flow interaction between the main and minor jets was simulated numerically using FLUENT. The optimal mesh geometry was found and the k-epsilon turbulence model was defined as the best fit. The results of the experimental and computational studies were used to describe the shock attenuation effect as self-sustain oscillations in supersonic flow. The effects described here can be used

  1. Viability and DNA damage of halobacteria under physical stress conditions, including a simulated Martian atmosphere.

    NASA Astrophysics Data System (ADS)

    Weidler, G.; Leuko, S.; Radax, C.; Stan-Lotter, H.

    2003-04-01

    Several viable halobacteria were isolated from Alpine rock salt of Permo-Triassic age and described as novel species (1, 2). They have apparently survived in the salt sediments over extremely long periods of time. Halobacteria could therefore be suitable model organisms for exploring the possibility of long-term survival of microorganisms on other planets. In addition, the discovery of extraterrestrial halite makes it plausible to consider a specific search for halophiles, perhaps in the planned sample return missions to Mars. We are developing experimental procedures to test the viability of halobacteria under Martian conditions. Cells of two species of haloarchaea were used: 1. Halobacterium sp. NRC-1, whose whole genome sequence is already known; 2. Halococcus dombrowskii, a novel isolate from Austrian Permo-Triassic rock salt (2). Cells were grown in complex medium, containing up to 4 M NaCl, and were kept at minus 70riptsizeraisebox{1.5ex{o}}C for up to seven days, or freeze-dried in a lyophilizer. In addition, exposure experiments of halobacterial cells in a liquid nitrogen cooled Martian simulation chamber, at the Austrian Academy of Sceinces, were begun, where temperatures from about plus 5 to minus 100riptsizeraisebox{1.5ex{o}}C, pressures of 6-8 mbar, and a carbon dioxide atmosphere (or other gas mixtures) can be produced. Survival of cells was evaluated by determination of colony-forming units, microscopic examination of cellular morphology, and examination of potential strand breaks in DNA using pulsed-field gel electrophoresis (PFGE). Results showed a reduction of viable cells, following deep freezing, or lyophilization, respectively, by a factor of about 10 to 100, depending somewhat on the presence of cations, glycerol and other protective substances. Data will be presented on the DNA from stressed halobacterial cells, following digestion by restriction enzymes and separation by PFGE. 1) Stan-Lotter H, McGenity TJ, Legat A, Denner EBM, Glaser K

  2. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1989-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. Work performed has shown that laboratory measurements of the millimeter-wave opacity of ammonia between 7.5 mm and 9.3 mm and also at the 3.2 mm wavelength require a different lineshape to be used in the theoretical prediction for millimeter-wave ammonia opacity than was previously used. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  3. Instrumentation for surveying the lower part of the atmosphere in extremes conditions

    NASA Astrophysics Data System (ADS)

    Gobinddass, Marie-Line; Molinie, Jack; Richard, Sandrine; Jean-Louis, Sabrina

    To observe atmospheric phenomena such as clouds, precipitation and wind in order to understand how they form and evolve meteorologists use few instruments which allows to measure parameters as temperature, pressure and humidity. In the specific case of Kourou region where the French Space Agency is located the environment and safeguard group works on protecting biodiversity in and around the center. By considering a few scientific challenges in atmospheric science one of the main topics of this work consists on the understanding of the fluctuation of the atmosphere due to natural or industrials perturbations. We have considered a few experiences with many instruments in a large space of more than 1200 km per square. To differentiate and try to quantify industrial cloud from natural cloud or from natural atmosphere, the idea of using a drone has been experimented. The ratio of the cost of such experimentation with the relevance of the results which can be obtained will be discussed here. It is necessary to take into account the turbulence in the atmosphere due to industrial acid cloud or hot cloud. Finally, instead of taking the risk of having airbone measurements with a pilot we have thought of the tetherball due to it lower cost and for security reason. The technical experiment and few type of results will be presented here.

  4. Turbulence in wind turbine wakes under different atmospheric conditions from static and scanning Doppler LiDARs

    NASA Astrophysics Data System (ADS)

    Kumer, Valerie; Reuder, Joachim

    2016-04-01

    Wake characteristics are of great importance for wind park performances and turbine loads. Wind tunnel experiments helped to validate wake model simulations under neutral atmospheric conditions. However, recent studies show strongest wake characteristics and power losses in stable atmospheric conditions. Considering all three occurring atmospheric conditions this study presents a turbulence analysis of wind turbine wake flows measured by static and scanning Doppler LiDARs at the coast of the Netherlands. We use data collected by three Windcubes v1, a scanning Windcube 100S and sonic anemometers during the Wind Turbine Wake Experiment - Wieringermeer (WINTWEX-W). Turbulence parameters such as Turbulence Intensity (TI) and turbulent kinetic energy (TKE) are retrieved from the collected raw data. Results show highest turbulence on the flanks of the wake where strong wind shear dominates. On average the spatial turbulence distribution becomes more homogeneous with conical areas of enhanced TI. Highest turbulence and strongest wind deficits occur during stable weather conditions. Despite the ongoing research on the reliability of turbulence retrievals of Doppler LiDAR data, the results are consistent with sonic anemometer measurements and show promising opportunities for a qualitative study of wake characteristics such as wake strength and wake peak frequencies.

  5. Response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions

    USGS Publications Warehouse

    Rojstaczer, S.; Riley, F.S.

    1990-01-01

    The response to Earth tides is strongly governed by a dimensionless aquifer frequency Q???u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q???u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q???u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q???u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. -from Authors

  6. High Vertically Resolved Atmospheric State Revealed with IASI Single FOV Retrievals under All-weather Conditions

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.; Smith, William L.; Taylor, Jonathan P.; Schluessel, L. Peter; Strow, Larrybee; Mango, Stephen A.

    2008-01-01

    The Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite was launched on October 19, 2006. The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the IASI on the MetOp satellite. IASI possesses an ultra-spectral resolution of 0.25 cm(exp -1) and a spectral coverage from 645 to 2760 cm(exp -1). Ultra-spectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI observations are obtained and presented. These retrievals are further inter-compared with those obtained from airborne FTS system, such as the NPOESS Airborne Sounder Testbed - Interferometer (NAST-I), dedicated dropsondes, radiosondes, and ground based Raman Lidar. The capabilities of satellite ultra-spectral sounder such as the IASI are investigated to benefit future NPOESS operation.

  7. Cleansing of the atmosphere: smoke removal under natural and perturbed conditions

    SciTech Connect

    Hallett, J.

    1987-01-01

    The overall cleansing of the atmosphere can be related to the efficiency of the precipitation system, which is small for individual cumulus clouds (O), intermediate for air mass thunderstorms (20%), and larger for a steady-state system such as a supercell or a depression (70%). Air processed by the storm is cleaned of its aerosol loading, depending on the detail of the microphysical process. It follows that in any disaster scenario whereby large amounts of smoke are emitted into the troposphere - volcanic eruption, comet impact, nuclear exchange fires - the immediate cloud forming and precipitation processes are of major importance in determining the scavenging rate and overall scavenging efficiency. Even in the unpolluted atmosphere, removal by any precipitation process depends critically on the likelihood of the aerosol containing air passing into a suitable precipitation system. In the case of Chernobyl, with iodine-activated soot, its removals is more likely as it passes into an ice-forming precipitation system, to be removed directly by ice nucleation. In the present atmosphere, statistics of parcel trajectory can give a mean removal rate; in the case of the perturbed atmosphere, major uncertainties remain on the nature and scale of the initial circulations.

  8. Approximate analytical solution to diurnal atmospheric boundary-layer growth under well-watered conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The system of governing equations of a simplified slab model of the uniformly-mixed, purely convective, diurnal atmospheric boundary layer (ABL) is shown to allow immediate solutions for the potential temperature and specific humidity as functions of the ABL height and net radiation when expressed i...

  9. The New Pelagic Operational Observatory of the Catalan Sea (OOCS) for the Multisensor Coordinated Measurement of Atmospheric and Oceanographic Conditions

    PubMed Central

    Bahamon, Nixon; Aguzzi, Jacopo; Bernardello, Raffaele; Ahumada-Sempoal, Miguel-Angel; Puigdefabregas, Joan; Cateura, Jordi; Muñoz, Eduardo; Velásquez, Zoila; Cruzado, Antonio

    2011-01-01

    The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39′N, 2°54′E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the

  10. The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the multisensor coordinated measurement of atmospheric and oceanographic conditions.

    PubMed

    Bahamon, Nixon; Aguzzi, Jacopo; Bernardello, Raffaele; Ahumada-Sempoal, Miguel-Angel; Puigdefabregas, Joan; Cateura, Jordi; Muñoz, Eduardo; Velásquez, Zoila; Cruzado, Antonio

    2011-01-01

    The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39'N, 2°54'E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the coordinated

  11. Dependence of positive and negative sprite morphology on lightning characteristics and upper atmospheric ambient conditions

    NASA Astrophysics Data System (ADS)

    Qin, Jianqi; Celestin, Sebastien; Pasko, Victor P.

    2013-05-01

    Carrot sprites, exhibiting both upward and downward propagating streamers, and columniform sprites, characterized by predominantly vertical downward streamers, represent two distinct morphological classes of lightning-driven transient luminous events in the upper atmosphere. It is found that positive cloud-to-ground lightning discharges (+CGs) associated with large charge moment changes (QhQ) tend to produce carrot sprites with the presence of a mesospheric region where the electric field exceeds the value 0.8Ek and persists for >˜2 ms, whereas those associated with small QhQ are only able to produce columniform sprites. Columniform sprites may also appear in the periphery of a sprite halo produced by +CGs associated with large QhQ. For a sufficiently large QhQ, the time dynamics of the QhQ determines the specific shape of the carrot sprites. In the case when the sufficiently large QhQ is produced mainly by an impulsive return stroke, strong electric field is produced at high altitudes and manifests as a bright halo, and the corresponding conductivity enhancement lowers/enhances the probability of streamer initiation inside/below the sprite halo. A more impulsive return stroke leads to a more significant conductivity enhancement (i.e., a brighter halo). This conductivity enhancement also leads to fast decay and termination of the upper diffuse region of carrot sprites because it effectively screens out the electric field at high altitudes. On the contrary, if the sufficiently large QhQ is produced by a weak return stroke (i.e., a dim halo) accompanied by intense continuing current, the lightning-induced electric field at high altitudes persists at a level that is comparable to Ek, and therefore an extensive upper diffuse region can develop. Furthermore, we demonstrate that `negative sprites' (produced

  12. Atmosphere and water loss from early Mars under extreme solar wind and extreme ultraviolet conditions.

    PubMed

    Terada, Naoki; Kulikov, Yuri N; Lammer, Helmut; Lichtenegger, Herbert I M; Tanaka, Takashi; Shinagawa, Hiroyuki; Zhang, Tielong

    2009-01-01

    The upper limits of the ion pickup and cold ion outflow loss rates from the early martian atmosphere shortly after the Sun arrived at the Zero-Age-Main-Sequence (ZAMS) were investigated. We applied a comprehensive 3-D multi-species magnetohydrodynamic (MHD) model to an early martian CO(2)-rich atmosphere, which was assumed to have been exposed to a solar XUV [X-ray and extreme ultraviolet (EUV)] flux that was 100 times higher than today and a solar wind that was about 300 times denser. We also assumed the late onset of a planetary magnetic dynamo, so that Mars had no strong intrinsic magnetic field at that early period. We found that, due to such extreme solar wind-atmosphere interaction, a strong magnetic field of about approximately 4000 nT was induced in the entire dayside ionosphere, which could efficiently protect the upper atmosphere from sputtering loss. A planetary obstacle ( approximately ionopause) was formed at an altitude of about 1000 km above the surface due to the drag force and the mass loading by newly created ions in the highly extended upper atmosphere. We obtained an O(+) loss rate by the ion pickup process, which takes place above the ionopause, of about 1.5 x 10(28) ions/s during the first < or =150 million years, which is about 10(4) times greater than today and corresponds to a water loss equivalent to a global martian ocean with a depth of approximately 8 m. Consequently, even if the magnetic protection due to the expected early martian magnetic dynamo is neglected, ion pickup and sputtering were most likely not the dominant loss processes for the planet's initial atmosphere and water inventory. However, it appears that the cold ion outflow into the martian tail, due to the transfer of momentum from the solar wind to the ionospheric plasma, could have removed a global ocean with a depth of 10-70 m during the first < or =150 million years after the Sun arrived at the ZAMS. PMID:19216683

  13. Visible spectroscopy as a tool for the assessment of storage conditions of fresh pork packaged in modified atmosphere.

    PubMed

    Spanos, Dimitrios; Christensen, Mette; Tørngren, Mari Ann; Baron, Caroline P

    2016-03-01

    The storage conditions of fresh meat are known to impact its colour and microbial shelf life. In the present study, visible spectroscopy was evaluated as a method to assess meat storage conditions and its optimisation. Fresh pork steaks (longissimus thoracis et lumborum and semimembranosus) were placed in modified atmosphere packaging using gas mixtures containing 0, 40, 50, and 80% oxygen, and stored with or without light for up to 9days. Principal component analysis of visible reflectance spectra (400-700nm) showed that the colour of the different meat cuts was affected by presence of oxygen, illumination, and storage time. Differences in the oxygen levels did not contribute to the observed variance. Predictive models based on partial least squares regression-discriminant analysis exhibited high potency in the classification of the storage parameters of meat cuts packaged in modified atmosphere. The study demonstrates the applicability of visible spectroscopy as a tool to assess the storage conditions of meat cuts packaged in modified atmosphere. PMID:26658010

  14. Nonlinear acoustic wave propagation in atmosphere. Absorbing boundary conditions for exterior problems

    NASA Technical Reports Server (NTRS)

    Hariharan, S. I.

    1985-01-01

    Elliptic and hyperbolic problems in unbounded regions are considered. These problems, when one wants to solve them numerically, have the difficulty of prescribing boundary conditions at infinity. Computationally, one needs a finite region in which to solve these problems. The corresponding conditions at infinity imposed on the finite distance boundaries should dictate the boundary conditions at infinity and be accurate with respect to the interior numerical scheme. The treatment of these boundary conditions for wave-like equations is discussed.

  15. Effect of experimental conditions on size control of Au nanoparticles synthesized by atmospheric microplasma electrochemistry.

    PubMed

    Huang, Xunzhi; Li, Yongsheng; Zhong, Xiaoxia

    2014-01-01

    Atmospheric microplasma electrochemistry was utilized to synthesize Au nanoparticles (NPs). The synthesized Au NPs were investigated as a function of reduction current, solution temperature, and stirring (or not) by using ultraviolet-visible (UV-Vis) absorbance and transmission electron microscopy (TEM). It was illustrated that high current promoted the growth of Au NPs with small size, and more Au NPs with large size were synthesized as a rise of temperature. The Au NPs often with small size were synthesized as a result of stirring. The production rate, the electrostatic repulsion, and the residence time of the Au NPs at the interfacial region play an important role in the growth of Au NPs. The results shed light upon the roadmap to control the size and particle size distribution (PSD) of Au NPs synthesized by atmospheric microplasma electrochemistry. PMID:25364315

  16. Observation of antibacterial effects obtained at atmospheric and reduced pressures in afterglow conditions

    NASA Astrophysics Data System (ADS)

    Sarrette, J.-P.; Cousty, S.; Merbahi, N.; Nègre-Salvayre, A.; Clément, F.

    2010-01-01

    Bactericidal activities of three different afterglows operating at reduced and atmospheric pressures and ambient temperature are established and compared through the use of a unique protocol for bacteria (E. coli, CIP 54.8 T) exposition, recovery and numeration. The influence of three important parameters is shown. An original scenario for bacterial inactivation at reduced pressure is proposed, compatible with previously published results and with the observation of conformational changes appearing on the treated bacteria.

  17. Atmospheric turbulence power spectral measurements to long wavelengths for several meteorological conditions

    NASA Technical Reports Server (NTRS)

    Rhyne, R. H.; Murrow, H. N.; Sidwell, K.

    1976-01-01

    Use of power spectral design techniques for supersonic transports requires accurate definition of atmospheric turbulence in the long wavelength region below the knee of the power spectral density function curve. Examples are given of data obtained from a current turbulence flight sampling program. These samples are categorized as (1) convective, (2) wind shear, (3) rotor, and (4) mountain-wave turbulence. Time histories, altitudes, root-mean-square values, statistical degrees of freedom, power spectra, and integral scale values are shown and discussed.

  18. Parameterization and scaling of arctic ice conditions in the context of ice-atmospheric processes

    NASA Technical Reports Server (NTRS)

    Barry, R. G.; Steffen, K.; Heinrichs, J. F.; Key, J. R.; Maslanik, J. A.; Serreze, M. C.; Weaver, R. L.

    1995-01-01

    The goals of this project are to observe how the open water/thin ice fraction in a high-concentration ice pack responds to different short-period atmospheric forcings, and how this response is represented in different scales of observation. The objectives can be summarized as follows: determine the feasibility and accuracy of ice concentration and ice typing by ERS-1 SAR backscatter data, and whether SAR data might be used to calibrate concentration estimates from optical and massive-microwave sensors; investigate methods to integrate SAR data with other satellite data for turbulent heat flux parameterization at the ocean/atmosphere interface; determine how the development and evolution of open water/thin ice areas within the interior ice pack vary under different atmospheric synoptic regimes; compare how open-water/thin ice fractions estimated from large-area divergence measurements differ from fractions determined by summing localized openings in the pack; relate these questions of scale and process to methods of observation, modeling, and averaging over time and space.

  19. Unimolecular HO2 Loss from Peroxy Radicals Formed in Autoxidation Is Unlikely under Atmospheric Conditions.

    PubMed

    Hyttinen, Noora; Knap, Hasse C; Rissanen, Matti P; Jørgensen, Solvejg; Kjaergaard, Henrik G; Kurtén, Theo

    2016-05-26

    A concerted HO2 loss reaction from a peroxy radical (RO2), formed from the addition of O2 to an alkyl radical, has been proposed as a mechanism to form closed-shell products in the atmospheric oxidation of organic molecules. We investigate this reaction computationally with four progressively oxidized radicals. Potential energy surfaces of the O2 addition and HO2 loss reactions were calculated at ROHF-RCCSD(T)-F12a/VDZ-F12//ωB97xD/aug-cc-pVTZ level of theory and the master equation solver for multienergy well reactions (MESMER) was used to calculate Bartis-Widom phenomenological rate coefficients. The rate coefficients were also compared with the unimolecular rate coefficients of the HO2 loss reaction calculated with transition state theory at atmospheric temperature and pressure. On the basis of our calculations, the unimolecular concerted HO2 loss is unlikely to be a major pathway in the formation of highly oxidized closed-shell molecules in the atmosphere. PMID:27163880

  20. Review Article: Atmospheric conditions inducing extreme precipitation over the eastern and western Mediterranean

    NASA Astrophysics Data System (ADS)

    Dayan, U.; Nissen, K.; Ulbrich, U.

    2015-11-01

    This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes that produce heavy rain storms. It distinguishes the western and eastern Mediterranean in order to point out specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger-scale circulations. The synoptic systems (tropical and extratropical) that account for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper synoptic-scale-level troughs, and mesoscale convective systems. Under tropical air-mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

  1. Review Article: Atmospheric conditions inducing extreme precipitation over the Eastern and Western Mediterranean

    NASA Astrophysics Data System (ADS)

    Dayan, U.; Nissen, K. M.; Ulbrich, U.

    2015-06-01

    This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes producing heavy rain storms. It distinguishes the Western and Eastern Mediterranean in order to point at specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger scale circulations. The synoptic systems (tropical and extra-tropical) accounting for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper-level synoptic-scale troughs, and meso-scale convective systems. Under tropical air mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

  2. Large-scale atmospheric conditions associated with heavy rainfall episodes in Southeast Brazil

    NASA Astrophysics Data System (ADS)

    Lima, Kellen Carla; Satyamurty, Prakki; Fernández, Júlio Pablo Reyes

    2010-07-01

    Heavy rainfall events in austral summer are responsible for almost all the natural disasters in Southeast Brazil. They are mostly associated with two types of atmospheric perturbations: Cold Front (53%) and the South Atlantic Convergence Zone (47%). The important question of what synoptic characteristics distinguish a heavy rainfall event (HRE) from a normal rainfall event (NRE) is addressed in this study. Here, the evolutions of such characteristics are identified through the anomalies with respect to climatology of the composite fields of atmospheric variables. The anomalies associated with HRE are significantly more intense than those associated with NRE in all fundamental atmospheric variables such as outgoing long-wave radiation, sea-level pressure, 500-hPa geopotential, lower and upper tropospheric winds. The moisture flux convergence over Southeast Brazil in the HRE composites is 60% larger than in the NRE composites. The energetics calculations for the HRE that occurred in the beginning of February 1988 strongly suggest that the barotropic instability played an important role in the intensification of the perturbation. These results, especially the intensities of the wind, pressure anomalies, and the moisture convergence are useful for the meteorologists of the Southeast Brazil for forecasting heavy precipitation.

  3. Parameterization and scaling of Arctic ice conditions in the context of ice-atmosphere processes

    NASA Technical Reports Server (NTRS)

    Barry, R. G.; Heinrichs, J.; Steffen, K.; Maslanik, J. A.; Key, J.; Serreze, M. C.; Weaver, R. W.

    1994-01-01

    This report summarizes achievements during year three of our project to investigate the use of ERS-1 SAR data to study Arctic ice and ice/atmosphere processes. The project was granted a one year extension, and goals for the final year are outlined. The specific objects of the project are to determine how the development and evolution of open water/thin ice areas within the interior ice pack vary under different atmospheric synoptic regimes; compare how open water/thin ice fractions estimated from large-area divergence measurements differ from fractions determined by summing localized openings in the pack; relate these questions of scale and process to methods of observation, modeling, and averaging over time and space; determine whether SAR data might be used to calibrate ice concentration estimates from medium and low-rate bit sensors (AVHRR and DMSP-OLS) and the special sensor microwave imager (SSM/I); and investigate methods to integrate SAR data for turbulent heat flux parametrization at the atmosphere interface with other satellite data.

  4. (abstract) Line Mixing Behavior of Hydrogen-Broadened Ammonia Under Jovian Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Spilker, Thomas R.

    1994-01-01

    Laboratory spectral data reported last year have been used to investigate the line mixing behavior of hydrogen-broadened ammonia inversion lines. The data show that broadening parameters appearing in the modified Ben-Reuven opacity formalism of Berge and Gulkis (1976) cannot maintain constant values over pressure ranges that include low to moderate pressures and high pressures. Also, they cannot change drastically in value, as in the Spilker (1990) revision of the Berge and Gulkis formalism. It has long been recognized that at low pressures, less than about 1 bar of a Jovian atmospheric mixture, a VVW formalism yields more accurate predictions of ammonia opacity than Ben-Reuven formalisms. At higher pressures the Ben-Reuven formalisms are more accurate. Since the Ben-Reuven lineshape collapses to a VVW lineshape in the low pressure limit, this low pressure inaccuracy of the Ben-Reuven formalisms is surprising. By incorporating various behavior, a new formalism is produced that is more accurate than previous formalisms, particularly in the critical 'transition region' from 0.5 to 2 bars, and that can be used without discontinuity from pressures of zero to hundreds of bars. The new formalism will be useful in such applications as interpretation of radio astronomical and radio occultation data on giant planet atmospheres, and radiative transfer modeling of those atmospheres.

  5. Optimizing Leaf Stomatal Conductance for Maximum Carbon Gain Under Salt Stressed and Elevated Atmospheric CO2 Conditions

    NASA Astrophysics Data System (ADS)

    Volpe, V.; Manzoni, S.; Marani, M.; Katul, G. G.

    2011-12-01

    Understanding how plants adapt to different stresses such as droughts, hypoxic or hyper-saline conditions is necessary to progress on the broader problem of how carbon and water exchange rates between the biosphere and atmosphere react to a changing climate. In this work, the effects of increased salinity on photosynthesis, stomatal and mesophyll conductances under ambient and elevated atmospheric CO2 conditions are explored. A model based on stomatal optimization principles, according to which plants maximize carbon gain at a given water loss at the leaf scale, is generalized to include mesophyll conductance and its dependence on water salinity. The optimization problem is solved for both a non-linear and a linear biochemical demand function and both approaches are consistent with reported gas-exchange measurements in fresh water and in salt stressed conditions. It is shown here that an increase in salt stress causes an increase in the cost of water (and reduced stomatal conductance) for the plant as it does under water stress conditions. However, these reductions in photosynthetic rates observed under increased salt stress conditions cannot be attributed to limitation of CO2 diffusion alone since salt stress did reduce the photosynthetic capacity of plants by 30-40%.

  6. Atmospheric conditions associated with heavy precipitation events in comparison to seasonal means in the western mediterranean region

    NASA Astrophysics Data System (ADS)

    Khodayar, Samiro; Kalthoff, Norbert; Kottmeier, Christoph

    2016-03-01

    The autumn atmospheric conditions associated with Heavy Precipitation Events (HPEs) in the western mediterranean region and differences with respect to the seasonal-mean conditions are investigated. Seasonal high-resolution simulations from the regional climate model COSMO-CLM covering the autumn periods of 2011 and 2012 are used. Atmospheric conditions at five different subdomains surrounding the western Mediterranean are considered, namely France, Italy (North and South), Spain, and North Africa. During HPEs, moisture and instability sources are located generally upstream of the target area over the sea, being transported by fast low-level winds towards the HPE areas. Concentration of high humidity over land and initiation of convection are highly related to the orography in the area. Stronger convective precipitation events occur at mid-level elevations rather than at higher altitudes. The significant increase in atmospheric moisture and instability, identified prior to HPEs, builds up in two different time lengths: atmospheric moisture increase could be traced back to at least 6-24 h before the initiation stage of the event, whereas an increase of Convective Available Potential Energy (CAPE) is detected in the hours prior to the event during the mature stage. The most intense HPEs are in general associated with higher values of integrated water vapour, CAPE, and low-level and mid-tropospheric wind speed. During HPEs in all subdomains, the dominant precipitation peak occurs between 1200 and 1800 UTC suggesting that convective precipitation prevails in most HPEs. The diurnal cycle of integrated water vapour during the mature stage of HPEs shows that the atmosphere remains wetter than average for most of the period and that only a decrease is seen after the afternoon precipitation peak. Negligible CAPE characterizes mean-seasonal conditions while the classical diurnal cycle with the peak in the early afternoon and much higher mean values occur during HPE events

  7. A gene homologous to beta-type carbonic anhydrase is essential for the growth of Corynebacterium glutamicum under atmospheric conditions.

    PubMed

    Mitsuhashi, S; Ohnishi, J; Hayashi, M; Ikeda, M

    2004-02-01

    Carbonic anhydrase catalyzes the interconversion of CO(2) and bicarbonate. We focused on this enzyme in the amino acid-producing organism Corynebacterium glutamicum in order to assess the availability of bicarbonate for carboxylation reactions essential to growth and for those required for L-lysine overproduction. A whole-genome sequence revealed two genes encoding putative beta-type and gamma-type carbonic anhydrases in C. glutamicum. These genes encode polypeptides containing zinc ligands strictly conserved in each type of carbonic anhydrase and were designated bca and gca, respectively. Internal deletion of the chromosomal bca gene resulted in a phenotype showing severely reduced growth under atmospheric conditions (0.04% CO(2)) on both complete and minimal media. The growth defect of the Delta bca strain was restored under elevated CO(2) conditions (5% CO(2)). Introduction of the red alga Porphyridium purpureum carbonic anhydrase gene ( pca) could compensate for the bca deletion, allowing normal growth under an atmospheric level of CO(2). In contrast, the Delta gca strain behaved identically to the wild-type strain with respect to growth, irrespective of the CO(2) conditions. Attempts to increase the dosage of bca, gca, and pca in the defined L-lysine-producing strain C. glutamicum AHD-2 led to no discernable effects on growth and production. Northern blot analysis indicated that the bca transcript in strain AHD-2 and another L-lysine producer, C. glutamicum B-6, was present at a much higher level than in the wild-type strain, particularly during exponential growth phases. These results indicate that: (1) the bca product is essential to achieving normal growth under ordinary atmospheric conditions, and this effect is most likely due to the bca product's ability to maintain favorable intracellular bicarbonate/CO(2) levels, and (2) the expression of bca is induced during exponential growth phases and also in the case of L-lysine overproduction, both of which are

  8. The influence of atmospheric conditions on the leakage current of ceramic insulators on the Colombian Caribbean coast.

    PubMed

    Castillo Sierra, Rafael; Oviedo-Trespalacios, Oscar; Candelo, John E; Soto, Jose D

    2015-02-01

    The contamination of electrical insulators is one of the major contributors to the risk of operation outages in electrical substations, especially in coastal zones with high salinity levels and atmospheric pollution. By using the measurement of leakage-currents, which is one of the main indicators of contamination in insulators, this work seeks to the determine the correlation with climatic variables, such as ambient temperature, relative humidity, solar irradiance, atmospheric pressure and wind speed and direction. The results obtained provide an input to the behaviour of the leakage current under atmospheric conditions that are particular to the Caribbean coast of Colombia. Spearman's rank correlation coefficients and principal component analysis are utilised to determine the significant relationships among the different variables under consideration. The necessary information for the study was obtained via historical databases of both atmospheric variables and the leakage current measured in over a period of 1 year in a 220-kV potential transformer insulator. We identified the influencing factors of temperature, humidity, radiation, wind speed and direction on the magnitude of the leakage current as the most relevant. PMID:25339532

  9. Vaccine Adverse Events

    MedlinePlus

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Vaccines, Blood & Biologics Home Vaccines, Blood & Biologics Safety & Availability ( ... Center for Biologics Evaluation & Research Vaccine Adverse Events Vaccine Adverse Events Share Tweet Linkedin Pin it More ...

  10. A climatological analysis of high-precipitation events in Dronning Maud Land, Antarctica, and associated large-scale atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Welker, Christoph; Martius, Olivia; Froidevaux, Paul; Reijmer, Carleen H.; Fischer, Hubertus

    2015-04-01

    Dronning Maud Land (DML), located in the Atlantic sector of East Antarctica, has become an area of intensive ice core research in recent years. Ice cores are used to study past climatic changes among others. To correctly interpret the ice core information, a profound understanding of the glaciological processes that lead to ice sheet formation as well as of the atmospheric conditions under which snow accumulation occurs is indispensable. Earlier studies showed that in DML especially high-precipitation events complicate the interpretation of ice core data. The atmospheric conditions leading to high precipitation in DML have been widely investigated, however these investigations tended to focus on individual case studies. Our main objective in this study is to analyse the link between high precipitation in DML and the large-scale atmospheric conditions from a climatological perspective. High-precipitation events are analysed at Halvfarryggen ice dome (71.2°S, 6.7°W), a potential ice core drilling site situated in the relatively wet, low-altitude coastal region of DML, and at Kohnen Station (75°S, 0.1°E), a deep ice core drilling site located in DML's dry, high-altitude interior. For our climatological analysis, we primarily make use of atmospheric reanalysis data from the ERA-Interim project for 1979-2009; complemented by precipitation data from the Antarctic Mesoscale Prediction System and snow accumulation measurements from automatic weather stations located near Halvfarryggen and Kohnen Station. To describe the large-scale atmospheric conditions, we focus on vertically integrated water vapour transport (IVT), upper level potential vorticity, surface cyclone frequency, and atmospheric blocking frequency. In line with earlier studies, we find that high-precipitation events in DML are typically associated with amplified upper level waves. This large-scale atmospheric flow pattern is preceded by the downstream development of a Rossby wave train from the eastern

  11. Reverse Engineering Adverse Outcome Pathways

    SciTech Connect

    Perkins, Edward; Chipman, J.K.; Edwards, Stephen; Habib, Tanwir; Falciani, Francesco; Taylor, Ronald C.; Van Aggelen, Graham; Vulpe, Chris; Antczak, Philipp; Loguinov, Alexandre

    2011-01-30

    The toxicological effects of many stressors are mediated through unknown, or poorly characterized, mechanisms of action. We describe the application of reverse engineering complex interaction networks from high dimensional omics data (gene, protein, metabolic, signaling) to characterize adverse outcome pathways (AOPs) for chemicals that disrupt the hypothalamus-pituitary-gonadal endocrine axis in fathead minnows. Gene expression changes in fathead minnow ovaries in response to 7 different chemicals, over different times, doses, and in vivo versus in vitro conditions were captured in a large data set of 868 arrays. We examined potential AOPs of the antiandrogen flutamide using two mutual information theory methods, ARACNE and CLR to infer gene regulatory networks and potential adverse outcome pathways. Representative networks from these studies were used to predict a network path from stressor to adverse outcome as a candidate AOP. The relationship of individual chemicals to an adverse outcome can be determined by following perturbations through the network in response to chemical treatment leading to the nodes associated with the adverse outcome. Identification of candidate pathways allows for formation of testable hypotheses about key biologic processes, biomarkers or alternative endpoints, which could be used to monitor an adverse outcome pathway. Finally, we identify the unique challenges facing the application of this approach in ecotoxicology, and attempt to provide a road map for the utilization of these tools. Key Words: mechanism of action, toxicology, microarray, network inference

  12. Improvement in Simulation of Eurasian Winter Climate Variability with a Realistic Arctic Sea Ice Condition in an Atmospheric GCM

    NASA Technical Reports Server (NTRS)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988-2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to approx. 0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated.

  13. Uniform amorphous lactose microspheres formed in simultaneous convective and dehydration antisolvent precipitation under atmospheric conditions.

    PubMed

    Mansouri, S; Fu, N; Woo, M W; Chen, X D

    2012-10-01

    A simultaneous convection-dehydration and antisolvent precipitation approach has been shown to produce uniform microsized lactose particles from aqueous droplet at atmospheric pressure. Microparticles with high uniformity having diameters of between 1.0 and 2.4 μm have been obtained. The precipitation of the microparticles is driven by a unique self-assembly mechanism that cannot be fully elucidated by supersaturation alone. Further analysis suggests that structural changes in the solvent/antisolvent mixture, due to hydrophobic hydration, could play a role in the precipitation process observed. PMID:22950653

  14. Conditions for observation of the enhanced backscattering phenomenon in a turbulent atmosphere

    NASA Astrophysics Data System (ADS)

    Chrzanowski, Janusz; Kirkiewicz, Jozef; Kravtsov, Yuri A.

    2003-11-01

    Influence of enhanced backscattering effect on laser measurements of dust and aerosols content in a turbulent atmosphere is discussed. It is shown that doubling of the backscattered light intensity, characteristic for enhanced backscattering, leads to overestimating dust content in the air. To avoid undesirable effect of overestimation, it is recommended to displace receiving aperture sidewise relatively to laser source. Other method to eliminate overestimation is to use wider laser beam and extended receiving aperture as compared to coherence radius of the scattered wave field.

  15. Effects of atmospheric conditions on the formation of winter precipitation types

    NASA Astrophysics Data System (ADS)

    Theriault, Julie M.

    Winter storms produce major problems for society and their precipitation is often the key factor responsible. The objective of this thesis is to better understand the formation of this precipitation. A multi-moment bulk microphysics scheme coupled with a cloud model has been developed to address this issue. It predicts the mass mixing ratio and total number concentration for many hydrometeor categories including rain, snow, freezing rain, wet snow, slush and ice pellets. Semi-melted particles have been incorporated into the bulk scheme since they are commonly formed at temperatures near 0°C and they influence the formation of other types of precipitation within the atmosphere and reaching the surface. Considering a vertical profile in the atmosphere, the precipitation type characteristics during the 1998 Ice Storm in the Montreal area have been compared with aircraft measurements. Many of the observed characteristics were reproduced by the model. Also, sensitivity tests on the precipitation types formed during the Ice Storm were performed. The results show that small variations (<0.5°C) in the temperature profiles as well as the precipitation rate can have major impacts on the types of precipitation formed at the surface in such a catastrophic event. Using a two-dimensional cloud model, the effects of the background wind on the precipitation type evolution within the atmosphere and at the surface have likewise been investigated. These results were compared with observations taken during a field project held at the Centre for Atmospheric Research Experiments (CARE) in the Toronto area during the winter 2006-2007. The results reproduced many of the precipitation types observed. The background wind field and snowfield aloft influence the type and the amount of precipitation reaching the surface. Overall, the environmental factors such as the temperature, the degree of saturation and the background wind critically affect the type of winter precipitation formed. This

  16. Migration, neighborhoods, and networks: approaches to understanding how urban environmental conditions affect syndemic adverse health outcomes among gay, bisexual and other men who have sex with men.

    PubMed

    Egan, James E; Frye, Victoria; Kurtz, Steven P; Latkin, Carl; Chen, Minxing; Tobin, Karin; Yang, Cui; Koblin, Beryl A

    2011-04-01

    Adopting socioecological, intersectionality, and lifecourse theoretical frameworks may enhance our understanding of the production of syndemic adverse health outcomes among gay, bisexual and other men who have sex with men (MSM). From this perspective, we present preliminary data from three related studies that suggest ways in which social contexts may influence the health of MSM. The first study, using cross-sectional data, looked at migration of MSM to the gay resort area of South Florida, and found that amount of time lived in the area was associated with risk behaviors and HIV infection. The second study, using qualitative interviews, observed complex interactions between neighborhood-level social environments and individual-level racial and sexual identity among MSM in New York City. The third study, using egocentric network analysis with a sample of African American MSM in Baltimore, found that sexual partners were more likely to be found through face-to-face means than the Internet. They also observed that those who co-resided with a sex partner had larger networks of people to depend on for social and financial support, but had the same size sexual networks as those who did not live with a partner. Overall, these findings suggest the need for further investigation into the role of macro-level social forces on the emotional, behavioral, and physical health of urban MSM. PMID:21369730

  17. Migration, Neighborhoods, and Networks: Approaches to Understanding How Urban Environmental Conditions Affect Syndemic Adverse Health Outcomes Among Gay, Bisexual and Other Men Who Have Sex with Men

    PubMed Central

    Egan, James E.; Kurtz, Steven P.; Latkin, Carl; Chen, Minxing; Tobin, Karin; Yang, Cui; Koblin, Beryl A.

    2011-01-01

    Adopting socioecological, intersectionality, and lifecourse theoretical frameworks may enhance our understanding of the production of syndemic adverse health outcomes among gay, bisexual and other men who have sex with men (MSM). From this perspective, we present preliminary data from three related studies that suggest ways in which social contexts may influence the health of MSM. The first study, using cross-sectional data, looked at migration of MSM to the gay resort area of South Florida, and found that amount of time lived in the area was associated with risk behaviors and HIV infection. The second study, using qualitative interviews, observed complex interactions between neighborhood-level social environments and individual-level racial and sexual identity among MSM in New York City. The third study, using egocentric network analysis with a sample of African American MSM in Baltimore, found that sexual partners were more likely to be found through face-to-face means than the Internet. They also observed that those who co-resided with a sex partner had larger networks of people to depend on for social and financial support, but had the same size sexual networks as those who did not live with a partner. Overall, these findings suggest the need for further investigation into the role of macro-level social forces on the emotional, behavioral, and physical health of urban MSM. PMID:21369730

  18. Effect of Shadowing on Survival of Bacteria under Conditions Simulating the Martian Atmosphere and UV Radiation▿ †

    PubMed Central

    Osman, Shariff; Peeters, Zan; La Duc, Myron T.; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

    2008-01-01

    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-μm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-μm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (∼5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

  19. Atmospheric conditions governing anomalies of the summer and winter cloudiness in Spitsbergen

    NASA Astrophysics Data System (ADS)

    Bednorz, Ewa; Kaczmarek, Dominika; Dudlik, Przemysław

    2016-01-01

    The study is based on data concerning cloudiness for the years 1981-2010 from Svalbard Lufthavn. Atmospheric circulation was characterized using a catalogue of circulation types developed by Niedźwiedź (2013) and average daily values of atmospheric pressure. Intensive cyclogenesis taking place over the north Atlantic expressed by lower-than-normal sea level pressure (SLP), particularly over the Fram Strait and over the east coast of Greenland, enhances the meridional air transport from the southern sector which conveys positive anomalies of cloudiness, namely a very cloudy weather. Negative anomalies of cloudiness over Svalbard Lufthavn occur in the winter when the north Atlantic cyclone path is shifted to the south and goes along the northern Norwegian shore towards the south Barents Sea. In summer, the influence of pressure patterns on cloudiness is weaker than in winter and different circulation patterns induce negative extremes of cloudiness. In the warm season, sunny weather occurs when a distinct anticyclone spreads over the Svalbard Archipelago and to its west, over the Fram Strait and the northern outskirts of the Greenland Sea. Extremely cloudy weather occurs in summer when a weak anticyclone spreads over the Barents Sea, the Novaya Zemlya archipelago and the Kara Sea, while slightly lower-than-normal pressure is observed over Greenland. Such a pressure pattern enhances southerly and south-westerly flow of air masses, bringing humid air. The results obtained in this study demonstrate that cloudiness over Spitsbergen is strongly controlled by the air circulation arising from pressure patterns.

  20. A computational study of particulate emissions from an open pit quarry under neutral atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Silvester, S. A.; Lowndes, I. S.; Hargreaves, D. M.

    2009-12-01

    The extraction of minerals from surface mines and quarries can produce significant fugitive dust emissions as a result of site activities such as blasting, road haulage, loading, crushing and stockpiling. If uncontrolled, these emissions can present serious environmental, health, safety and operational issues impacting both site personnel and the wider community. The dispersion of pollutant emissions within the atmosphere is principally determined by the background wind systems characterized by the atmospheric boundary layer (ABL). This paper presents an overview of the construction and solution of a computational fluid dynamics (CFD) model to replicate the development of the internal ventilation regime within a surface quarry excavation due to the presence of a neutral ABL above this excavation. This model was then used to study the dispersion and deposition of fugitive mineral dust particles generated during rock blasting operations. The paths of the mineral particles were modelled using Lagrangian particle tracking. Particles of four size fractions were released from five blast locations for eight different wind directions. The study concluded that dependent on the location of the bench blast within the quarry and the direction of the wind, a mass fraction of between 0.3 and 0.6 of the emitted mineral particles was retained within the quarry. The retention was largest when the distance from the blast location to the downwind pit boundary was greatest.

  1. Effect of atmospheric conditions on operation of terahertz systems for remote detection of ionizing materials

    SciTech Connect

    Nusinovich, Gregory S.; Kashyn, Dmytro G.; Tatematsu, Yoshinori; Idehara, Toshitaka

    2014-01-15

    This study was motivated by a new concept of remote detection of concealed radioactive materials by using a high power terahertz (THz) wave beam, which can be focused in a small spot where the wave electric field exceeds the breakdown threshold. In the presence of seed electrons in such a volume, this focusing can initiate the avalanche breakdown. Typically, an ambient density of free electrons is assumed to be at the level of one particle per cubic centimeter. So, when a breakdown-prone volume is smaller than 1 cm{sup 3}, there should be significant difference between the breakdown rates in the case of presence of additional sources of ionization versus its absence. Since the flux density of gamma rays emitted by radioactive materials rapidly falls with the distance from the source, while the intensity of THz waves also decreases with the distance due to wave attenuation in the atmosphere, it is important to find an optimal location of the breakdown to be initiated for a given distance between a radioactive material and a THz antenna. This problem is analyzed in a given paper with the account for not only atmospheric attenuation of THz waves but also the air turbulence.

  2. Physical conditions and nature of chemical anomalies in the atmosphere of Sirius A

    NASA Astrophysics Data System (ADS)

    Leushin, V. V.; Topilskaya, G. P.; Musaev, F. A.

    On the basis of the analysis of the observed equivalent line widths of Fe I, Fe II, Ti II in the spectra of alpha CMa and o Peg and calculation of abundances of these elements, oscillator strengths of the lines used are refined. With the improved oscillator strengths the iron and titanium abundances in the atmosphere of Sirius A are obtained with a higher accuracy than previously: lg N(Fe I) = 7.899 +/- 0.011, lg N(Fe II) = 7.908 +/- 0.010, lg N(Ti II) = 5.289 +/- 0.020. The improved accuracy allowed one to conclude that the surface magnetic field is absent in the atmosphere of Sirius A: H_s = 0+/-100 G. The equivalent widths of helium carbon and nitrogen lines of the red region of the spectrum are measured. The calculations of these lines with allowance for their blending with lines of other elements show normal helium abundance. From a comparison of features of alpha CMa and o Peg an assumption is made on possible reasons for the existence of the phenomenon of Am stars.

  3. Impact of uncertainties in atmospheric boundary conditions on ocean model solutions

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Ayan H.; Ponte, Rui M.; Forget, Gael

    2016-04-01

    We quantify differences in ocean model simulations derived solely from atmospheric uncertainties and investigate how they relate to overall model errors as inferred from comparisons with data. For this purpose, we use a global configuration of the MITgcm to simulate 4 ocean solutions for 2000-2009 using 4 reanalysis products (JRA-25, MERRA, CFSR and ERA-Interim) as atmospheric forcing. The simulations are compared against observations and against each other for selected variables (temperature, sea-level, sea-ice, streamfunctions, meridional heat and freshwater transports). Forcing-induced differences are comparable in magnitude to model-observation misfits for most near-surface variables in the tropics and sub-tropics, but typically smaller at higher latitudes and polar regions. Forcing-derived differences are expectedly largest near the surface and mostly limited to the upper 1000 m but can also be seen as deep as 4000 m, especially in regions of deep water formation. Errors are not necessarily local in nature and can be advected to different basins. Results indicate that while forcing adjustments might suffice in optimization procedures of near-surface fields and at low-to-mid latitudes, other control parameters are likely needed elsewhere. Forcing-induced differences can be dominated by large spatial scales and specific time scales (e.g. annual), and thus appropriate error covariances in space and time need to be considered in optimization methodologies.

  4. Missing data imputation of solar radiation data under different atmospheric conditions.

    PubMed

    Turrado, Concepción Crespo; López, María Del Carmen Meizoso; Lasheras, Fernando Sánchez; Gómez, Benigno Antonio Rodríguez; Rollé, José Luis Calvo; Juez, Francisco Javier de Cos

    2014-01-01

    Global solar broadband irradiance on a planar surface is measured at weather stations by pyranometers. In the case of the present research, solar radiation values from nine meteorological stations of the MeteoGalicia real-time observational network, captured and stored every ten minutes, are considered. In this kind of record, the lack of data and/or the presence of wrong values adversely affects any time series study. Consequently, when this occurs, a data imputation process must be performed in order to replace missing data with estimated values. This paper aims to evaluate the multivariate imputation of ten-minute scale data by means of the chained equations method (MICE). This method allows the network itself to impute the missing or wrong data of a solar radiation sensor, by using either all or just a group of the measurements of the remaining sensors. Very good results have been obtained with the MICE method in comparison with other methods employed in this field such as Inverse Distance Weighting (IDW) and Multiple Linear Regression (MLR). The average RMSE value of the predictions for the MICE algorithm was 13.37% while that for the MLR it was 28.19%, and 31.68% for the IDW. PMID:25356644

  5. Missing Data Imputation of Solar Radiation Data under Different Atmospheric Conditions

    PubMed Central

    Turrado, Concepción Crespo; López, María del Carmen Meizoso; Lasheras, Fernando Sánchez; Gómez, Benigno Antonio Rodríguez; Rollé, José Luis Calvo; de Cos Juez, Francisco Javier

    2014-01-01

    Global solar broadband irradiance on a planar surface is measured at weather stations by pyranometers. In the case of the present research, solar radiation values from nine meteorological stations of the MeteoGalicia real-time observational network, captured and stored every ten minutes, are considered. In this kind of record, the lack of data and/or the presence of wrong values adversely affects any time series study. Consequently, when this occurs, a data imputation process must be performed in order to replace missing data with estimated values. This paper aims to evaluate the multivariate imputation of ten-minute scale data by means of the chained equations method (MICE). This method allows the network itself to impute the missing or wrong data of a solar radiation sensor, by using either all or just a group of the measurements of the remaining sensors. Very good results have been obtained with the MICE method in comparison with other methods employed in this field such as Inverse Distance Weighting (IDW) and Multiple Linear Regression (MLR). The average RMSE value of the predictions for the MICE algorithm was 13.37% while that for the MLR it was 28.19%, and 31.68% for the IDW. PMID:25356644

  6. Kinetics of the heterogeneous photo oxidation of the pesticide bupirimate by OH-radicals and ozone under atmospheric conditions.

    PubMed

    Bouya, H; Errami, M; Chakir, A; Roth, E

    2015-09-01

    This article is concerned with the study of the photochemical degradation of bupirimate adsorbed on a quartz surface by atmospheric oxidants, namely ozone and OH radicals. OH oxidation experiments were conducted relative to two reference compounds, terbuthylazine and (4-chlorophenyl)(3,4-dimethoxyphenyl) methanone. Meanwhile, ozone oxidation experiments were performed in the absolute mode and were interpreted by both, the Surface Layer Reaction and the Gas Surface Reaction models of heterogeneous reactions. The obtained results show that the rate constants for the reactions between bupirimate and OH radicals and ozone are (cm(3)molecule(-1)s(-1)): (1.06 ± 0.87) × 10(-12) and (5.4 ± 0.3) × 10(-20), respectively. As a consequence, for the experimental conditions used in this study, the lifetime of bupirimate at quartz like surface/atmosphere interfaces is several months against ozone and a tenth of days against OH-radical. PMID:25966935

  7. Characterization of Summertime Oceanic Boundary Conditions for Coastal and Regional Atmospheric Chemistry Modeling in California

    NASA Astrophysics Data System (ADS)

    Hübler, G.; Parrish, D. D.; Aikin, K. C.; Oltmans, S. J.; Johnson, B. J.; Ives, M.; Thouret, V.; Nédélec, P.; Cammas, J.; Team, A.

    2009-12-01

    Most detailed photochemical modeling must be carried out at regional or air basin scales in order to achieve the spatial resolution and detailed treatment of the chemical mechanisms required for realistic treatment of local air quality. Consequently these models must define upwind boundary conditions at the edge of the model domain. Uncertainty in the appropriate boundary conditions contributes significantly to the overall uncertainty of the photochemical modeling in California. Here we will investigate the available data sets to define to the extent possible the average summertime oceanic boundary conditions, the variability about that average, and the horizontal and vertical variability of the boundary conditions. The data sets considered will include ozone sondes launched from Trinidad Head CA, ozone and carbon monoxide profiles measured by MOZAIC aircraft flights into 4 west coast US cities, and the many chemical species measured on four aircraft flights conducted during the CARB-ARCTAS campaign during summer 2008

  8. Pool boiling of water on nano-structured micro wires at sub-atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Arya, Mahendra; Khandekar, Sameer; Pratap, Dheeraj; Ramakrishna, S. Anantha

    2015-10-01

    Past decades have seen active research in enhancement of boiling heat transfer by surface modifications. Favorable surface modifications are expected to enhance boiling efficiency. Several interrelated mechanisms such as capillarity, surface energy alteration, wettability, cavity geometry, wetting transitions, geometrical features of surface morphology, etc., are responsible for change in the boiling behavior of modified surfaces. Not much work is available on pool boiling at low pressures on microscale/nanoscale geometries; low pressure boiling is attractive in many applications wherein low operating temperatures are desired for a particular working fluid. In this background, an experimental setup was designed and developed to investigate the pool boiling performance of water on (a) plain aluminum micro wire (99.999 % pure) and, (b) nano-porous alumina structured aluminum micro wire, both having diameter of 250 µm, under sub-atmospheric pressure. Nano-structuring on the plain wire surface was achieved via anodization. Two samples, A and B of anodized wires, differing by the degree of anodization were tested. The heater length scale (wire diameter) was much smaller than the capillary length scale. Pool boiling characteristics of water were investigated at three different sub-atmospheric pressures of 73, 123 and 199 mbar (corresponding to T sat = 40, 50 and 60 °C). First, the boiling characteristics of plain wire were measured. It was noticed that at sub-atmospheric pressures, boiling heat transfer performance for plain wire was quite low due to the increased bubble sizes and low nucleation site density. Subsequently, boiling performance of nano-structured wires (both Sample A and Sample B) was compared with plain wire and it was noted that boiling heat transfer for the former was considerably enhanced as compared to the plain wire. This enhancement is attributed to increased nucleation site density, change in wettability and possibly due to enhanced pore scale

  9. Microwave plasma based single step method for free standing graphene synthesis at atmospheric conditions

    SciTech Connect

    Tatarova, E.; Henriques, J.; Dias, A.; Ferreira, C. M.; Luhrs, C. C.; Phillips, J.; Abrashev, M. V.

    2013-09-23

    Microwave atmospheric pressure plasmas driven by surface waves were used to synthesize graphene sheets from vaporized ethanol molecules carried through argon plasma. In the plasma, ethanol decomposes creating carbon atoms that form nanostructures in the outlet plasma stream, where external cooling/heating was applied. It was found that the outlet gas stream temperature plays an important role in the nucleation processes and the structural quality of the produced nanostructures. The synthesis of few layers (from one to five) graphene has been confirmed by high-resolution transmission electron microscopy. Raman spectral studies were conducted to determine the ratio of the 2D to G peaks (>2). Disorder D-peak to G-peak intensity ratio decreases when outlet gas stream temperature decreases.

  10. Synthesis of highly luminescent mercaptosuccinic acid-coated CdSe nanocrystals under atmospheric conditions.

    PubMed

    Dong, Meiting; Xu, Jingyi; Liu, Shuxian; Zhou, Ying; Huang, Chaobiao

    2014-11-01

    Here we report a facile one-pot method for the preparation of high-quality CdSe nanocrystals (NCs) in aqueous solution under an air atmosphere. Compared with the traditional use of NaHSe or H2 Se, the more stable sodium selenite is utilized as the Se source for preparing highly luminescent CdSe nanocrystals. By using mercaptosuccinic acid (MSA) as the capping agent and borate-citrate acid as the buffering solution, CdSe nanocrystals with high quantum yield (up to 70%) have been synthesized conveniently. The influence of different experimental parameters, such as the pH of the precursor solution, the molar ratio of Cd(2+) to Na2 SeO3 and Cd(2+) to MSA on the CdSe nanocrystals, has been systematically investigated. The prepared CdSe NCs were spherical with a size of ~ 5 nm. PMID:24639040

  11. Laboratory exposure systems to simulate atmospheric degradation of building stone under dry and wet deposition conditions

    NASA Astrophysics Data System (ADS)

    Johnson, J. B.; Haneef, S. J.; Hepburn, B. J.; Hutchinson, A. J.; Thompson, G. E.; Wood, G. C.

    The design philosophy, construction and use of two exposure test systems are described, in which the objective is to simulate the degradation of stone samples under, respectively, the 'dry' and 'wet' deposition of atmospheric pollutants. Some element of realistic acceleration is possible in certain experiments. Particular emphasis is placed upon using known presentation rates of the pollutants, both in respect of typical depositions of pollutants and their oxidation products appropriate for an industrial atmosphere. In the dry deposition rig, SO 2, NO 2, NO, HCl and the oxidant O 3 are presented individually or together at realistic deposition rates. In the wet deposition apparatus, SO 2-4, NO -3 and Cl - at a pH of 3.5, simulating 'acid rain' but in a more concentrated form, are deposited. The dry deposition chamber can be operated at constant relative humidity (typically 84%) with pre-dried or precisely wetted stones to simulate episodic rain wetting, or using other methods of wet/dry cycling, which are also a feature of the wet deposition chamber. Heating and cooling of the samples is also possible, as is the use of shaped or coupled stones of different kinds such as are found in a building facade. The results are illustrated in terms of data on the weight change, the anion content of stone and run-off, the pH change of run-off and the total calcium reacted, using Portland stone, as a prelude to later papers in which behaviour of a whole matrix of stone types and environments is presented and discussed. Such an approach permits the eventual production of 'pollutant-material response' relationships and damage functions for comparison with and prediction of external exposure results.

  12. Kinetic study of heterogeneous ozonolysis of alachlor, trifluralin and terbuthylazine adsorbed on silica particles under atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Pflieger, Maryline; Monod, Anne; Wortham, Henri

    To better understand the atmospheric behaviour of pesticides, heterogeneous ozonolysis of three herbicides (alachlor, terbuthylazine and trifluralin) adsorbed on silica particles were performed in a flow reactor. The experimental setup used in this study and previously validated ( Pflieger et al., 2009) has been specially developed to investigate extremely slow reactivity. The pesticides were adsorbed on particles using a gas/solid adsorption equilibrium, in order to simulate atmospheric conditions. After exposure to ozone concentrations ranging from 5 to 41 ppm during 90 min to 6 h, the kinetics were calculated by comparing the initial and the remaining amounts of pesticides adsorbed on silica particles. This work offers the first results of heterogeneous ozonolysis of alachlor and trifluralin adsorbed on mineral particles. Although alachlor and terbuthylazine were expected to react with ozone, no degradation was observed which leads to a lifetime higher than 8 months towards ozonolysis (for 40 ppb of O 3). A significant degradation of trifluralin adsorbed on silica particles by heterogeneous ozonolysis was observed. The experimental data could be fit by both the Langmuir-Rideal and the Langmuir-Hinshelwood models resulting in atmospheric lifetimes (towards heterogeneous ozonolysis) of 40 and 32 days respectively (for 40 ppb of O 3). These results are discussed and compared to other studies.

  13. Influence of ocean surface conditions on atmospheric vertical thermodynamic structure and deep convection

    NASA Technical Reports Server (NTRS)

    Fu, Rong; Del Genio, Anthony D.; Rossow, William B.

    1994-01-01

    The authors analyze the influence of Sea Surface Temperature (SST) and surface wind divergence on atmospheric thermodynamic structure and the resulting effects on the occurrence of deep convection using National Meteorological Center radiosonde data and International Satellite Cloud Climatology Program data for July 1983-July 1985. The onset of deep convection requires not only the existence of positive convective available potential energy (CAPE), but also an unstable planetary boundary layer (PBL). A stable PBL is observed to suppress deep convection even when CAPE is positive. Variations of SST have a major effect on CAPE, but surface wind divergence can also affect deep convection by changing the lapse rate in the lower troposphere and humidity in the PBL. Specifically, when SST is greater than or equal to 28 C, CAPE is always positive, and surface wind divergence does not qualitatively change the buoyancy profile above the PBL. Strong surface wind divergence, however, stabilizes the PBL so as to suppress the initiation of deep convection. In warm SST regions, CAPE is greater than 0 regardless of assumptions about condensate loading, although the pseudoadiabatic limit is more consistent with the observed deep convection than the reversible moist-adiabatic limit under these circumstances. When SST is less than 27 C, CAPE is usually negative and inhibits convection, but strong surface wind convergence can destabilize the inversion layer and moisten the PBL enough to make the atmosphere neutrally stable in the mean. As a result, deep convection is generally enhanced either when SST is greater than or equal to 28 C in the absence of strong surface wind divergence or when strong surface wind convergence occurs even if SST is less than 27 C. The anomalous suppression of deep convection in the warm area of the equatorial west Pacific lying between the intertropical convergence zone (ITCZ) and south Pacific convergence zone (SPCZ) is probably caused by dryness in the

  14. Storage quality of shelled green peas under modified atmosphere packaging at different storage conditions.

    PubMed

    Anurag, Rahul K; Manjunatha, M; Jha, Shyam Narayan; Kumari, Leena

    2016-03-01

    Storage quality of shelled green peas (Pisum sativum var. sativum L) was investigated under modified atmosphere packaging (MAP: perforated and non perforated) compared to unsealed samples, respectively, at T1 (4 ± 1 °C and 94 ± 2 % RH) and T2 (10 ± 1 °C and 90 ± 2 % RH) for each sample and during period of storage (8, 16 and 24 days). Modified atmosphere (MA) was created using low density polyethylene (LDPE) film packages having 107 μm of film thickness and package size of 0.022 m(2). Quality parameters viz., weight loss (WL), total phenolic content (TPC), instrumental colour, ascorbic acid (AA) and sensory characteristics were evaluated during storage period. Weight loss was in the range of 0.18 to 3.54 (zero perforation at T1), 0.21 to 6.48(unsealed samples at T2) and 0.31 to 9.64 % (zero perforation at T1) after 8, 16 and 24 days of storage, respectively. Total phenolic content significantly increased to 102.47-161.54 mg/100 g from an initial value of 91.53 mg/100 g for all the samples and treatments studied. The MAP non perforated sample stored at T2 recorded maximum Hunter 'L' and '-a' colour values than all other samples. A significant decrease in AA content was observed in all the samples with maximum loss (53.77 %) in unsealed sample stored at T2, whereas MAP (3 perforations) sample stored at T1 retained maximum AA (90.50 %). Sensory quality analysis revealed that MAP (3 perforations) sample stored at T1 was in acceptable quality, with good appearance and overall acceptance. The study shows that shelled green peas can be stored in MAP with 3 perforations (0.4 mm dia) in the temperature range of 4 to 10 °C and 90-94 % RH to extend shelf life with marketable quality for 24 days. PMID:27570289

  15. Effect of atmospheric pressure plasma treatment condition on adhesion of ramie fibers to polypropylene for composite

    NASA Astrophysics Data System (ADS)

    Li, Ying; Manolache, Sorin; Qiu, Yiping; Sarmadi, Majid

    2016-02-01

    In order to improve the interfacial adhesion between hydrophilic ramie fibers and hydrophobic polypropylene (PP) matrices, ramie fibers are modified by atmospheric pressure dielectric barrier discharge (DBD) plasma with our continuous ethanol flow technique in helium environment. A central composite design of experiments with different plasma processing parameter combinations (treatment current, treatment time and ethanol flow rate) is applied to find the most influential parameter and to obtain the best modification effect. Field emission scanning electron microscope (SEM) shows the roughened surfaces of ramie fibers from the treated groups due to plasma etching effect. Dynamic contact angle analysis (DCAA) demonstrates that the wettability of the treated fibers drastically decreases. Microbond pullout test shows that the interfacial shear strength (IFSS) between treated ramie fibers and PP matrices increases significantly. Residual gas analysis (RGA) confirms the creation of ethyl groups during plasma treatment. This study shows that our continuous ethanol flow technique is effective in the plasma modification process, during which the ethanol flow rate is the most influential parameter but all parameters have simultaneous influence on plasma modification effect of ramie fibers.

  16. Internet-based monitoring and prediction system of coal stockpile behaviors under atmospheric conditions.

    PubMed

    Yilmaz, Nihat; Ozdeniz, A Hadi

    2010-03-01

    Spontaneous combustion on industrial-scale stockpiles causes environmental problems and economic losses for the companies consuming large amounts of coal. In this study, an effective monitoring and prediction system based on internet was developed and implemented to prevent losses and environmental problems. The system was performed in a coal stockpile with 5 m width, 10 m length, 3 m height, and having 120 t of weight. The inner temperature data of the stockpile was recorded by 17 temperature sensors placed inside the stockpile at certain points. Additionally, the data relating to the air temperature, air humidity, atmospheric pressure, wind velocity, and wind direction that are the parameters affecting the coal stockpile were also recorded. The recorded values were analyzed with artificial neural network and Statistical modeling methods for prediction of spontaneous combustion. Real-time measurement values and model outputs were published with a web page on internet. The internet-based system can also provide real-time monitoring (combustion alarms, system status) and tele-controlling (Parameter adjusting, system control) through internet exclusively with a standard web browser without the need of any additional software. PMID:19238568

  17. Characteristics of Spatiotemporally Homogenized Boundary Layers at Atmospheric Reentry-like Conditions

    NASA Astrophysics Data System (ADS)

    Ulerich, Rhys; Moser, Robert

    2014-11-01

    Turbulent boundary layers approximating those found on the NASA Orion Multi-Purpose Crew Vehicle thermal protection system during atmospheric reentry from the International Space Station have been studied by direct numerical simulation using a ``slow growth'' spatiotemporal homogenization approach recently developed by Topalian et al. The two data sets generated were Mae ~ 0 . 9 and 1 . 15 homogenized boundary layers possessing Reθ ~ 382 and 531, respectively. Edge-to-wall temperature ratios were approximately 4.15 and wall blowing velocities, vw+ =vw /uτ , were roughly 8 ×10-3 . The favorable pressure gradients had Pohlhausen parameters between 25 and 42. Nusselt numbers under 22 were observed. Small or negative displacement effects are evident. Near-wall vorticity fluctuations show qualitatively different profiles than observed by Spalart [J. Fluid Mech. 187 (1988)] or Guarini et al. [J. Fluid Mech. 414 (2000)] suggesting that the simulations have atypical structures perhaps as a consequence of wall blowing or the homogenization. This material is based in part upon work supported by the Department of Energy [National Nuclear Security Administration] under Award Number [DE-FC52-08NA28615].

  18. Arctic lakes are continuous methane sources to the atmosphere under warming conditions

    NASA Astrophysics Data System (ADS)

    Tan, Zeli; Zhuang, Qianlai

    2015-05-01

    Methane is the second most powerful carbon-based greenhouse gas in the atmosphere and its production in the natural environment through methanogenesis is positively correlated with temperature. Recent field studies showed that methane emissions from Arctic thermokarst lakes are significant and could increase by two- to four-fold due to global warming. But the estimates of this source are still poorly constrained. By using a process-based climate-sensitive lake biogeochemical model, we estimated that the total amount of methane emissions from Arctic lakes is 11.86 Tg yr-1, which is in the range of recent estimates of 7.1-17.3 Tg yr-1 and is on the same order of methane emissions from northern high-latitude wetlands. The methane emission rate varies spatially over high latitudes from 110.8 mg CH4 m-2 day-1 in Alaska to 12.7 mg CH4 m-2 day-1 in northern Europe. Under Representative Concentration Pathways (RCP) 2.6 and 8.5 future climate scenarios, methane emissions from Arctic lakes will increase by 10.3 and 16.2 Tg CH4 yr-1, respectively, by the end of the 21st century.

  19. Wear of surface-engineered metal-on-metal bearings for hip prostheses under adverse conditions with the head loading on the rim of the cup.

    PubMed

    Leslie, Ian; Williams, Sophie; Isaac, Graham; Hatto, Peter; Ingham, Eileen; Fisher, John

    2013-04-01

    Clinical studies have found high wear rates, elevated ion levels and high revision rates of large-diameter metal-on-metal surface replacement bearings in some patients, which have been associated with edge loading of the head on the rim of the cup. We have simulated increased wear and ion levels in metal-on-metal bearings in vitro by introducing variations in translational and rotational positioning of the components, which reproduces stripe wear on the femoral head, cup rim wear and clinically relevant large as well as small wear particles. There is interest in technologies such as surface engineering, which might reduce metal wear and the release of wear particles and ions. Reduced wear with surface-engineered surface replacements compared to metal-on-metal controls has been reported under standard walking conditions with correctly aligned and concentric components. In this in vitro study, the wear of chromium nitride surface-engineered metal-on-metal bearings under conditions of microseparation associated with translational and rotational malpositioning of the components was investigated and the results were compared with a previously reported study of metal-on-metal bearings under the same conditions. Simulations were conducted using our unique hip simulation microseparation methodologies, which reproduce accelerated wear in metal-on-metal bearings and have previously been clinically validated with ceramic-on-ceramic bearings. Four of the six surface-engineered bearings had evidence of head contact on the rim of the cup, which produced stripe wear on the femoral head. Four of the six surface-engineered bearings (two without stripe and two with stripe wear) had lower wear than the previously reported high wearing metal-on-metal bearings. At 2 million cycles, two of the surface-engineered bearings had substantially increased wear rates, four times higher than the high wear rates previously reported for metal-on-metal bearings under the same conditions. There was

  20. An atmospheric pressure flow reactor: Gas phase kinetics and mechanism in tropospheric conditions without wall effects

    NASA Technical Reports Server (NTRS)

    Koontz, Steven L.; Davis, Dennis D.; Hansen, Merrill

    1988-01-01

    A new type of gas phase flow reactor, designed to permit the study of gas phase reactions near 1 atm of pressure, is described. A general solution to the flow/diffusion/reaction equations describing reactor performance under pseudo-first-order kinetic conditions is presented along with a discussion of critical reactor parameters and reactor limitations. The results of numerical simulations of the reactions of ozone with monomethylhydrazine and hydrazine are discussed, and performance data from a prototype flow reactor are presented.

  1. ADVERSE CUTANEOUS DRUG REACTION

    PubMed Central

    Nayak, Surajit; Acharjya, Basanti

    2008-01-01

    In everyday clinical practice, almost all physicians come across many instances of suspected adverse cutaneous drug reactions (ACDR) in different forms. Although such cutaneous reactions are common, comprehensive information regarding their incidence, severity and ultimate health effects are often not available as many cases go unreported. It is also a fact that in the present world, almost everyday a new drug enters market; therefore, a chance of a new drug reaction manifesting somewhere in some form in any corner of world is unknown or unreported. Although many a times, presentation is too trivial and benign, the early identification of the condition and identifying the culprit drug and omit it at earliest holds the keystone in management and prevention of a more severe drug rash. Therefore, not only the dermatologists, but all practicing physicians should be familiar with these conditions to diagnose them early and to be prepared to handle them adequately. However, we all know it is most challenging and practically difficult when patient is on multiple medicines because of myriad clinical symptoms, poorly understood multiple mechanisms of drug-host interaction, relative paucity of laboratory testing that is available for any definitive and confirmatory drug-specific testing. Therefore, in practice, the diagnosis of ACDR is purely based on clinical judgment. In this discussion, we will be primarily focusing on pathomechanism and approach to reach a diagnosis, which is the vital pillar to manage any case of ACDR. PMID:19967009

  2. Land surface and atmospheric conditions associated with heat waves over the Chickasaw Nation in the South Central United States

    NASA Astrophysics Data System (ADS)

    Lee, Eungul; Bieda, Rahama; Shanmugasundaram, Jothiganesh; Basara Richter, Heather

    2016-06-01

    Exposure to extreme heat was reconstructed based on regional land-atmosphere processes from 1979 to 2010 in the South Central U.S. The study region surrounds the Chickasaw Nation (CN), a predominantly Native American population with a highly prevalent burden of climate-sensitive chronic diseases. Land surface and atmospheric conditions for summer heat waves were analyzed during spring (March-April-May, MAM) and summer (June-July-August, JJA) based on the Climate and Ocean: Variability, Predictability, and Change maximum temperature definition for heat wave frequency (HWF). The spatial-temporal pattern of HWF was determined using empirical orthogonal function (EOF) analysis and the corresponding principle component time series of the first EOF of HWF. Statistically significant analyses of observed conditions indicated that sensible heat increased and latent heat fluxes decreased with high HWF in the South Central U.S. The largest positive correlations of sensible heat flux to HWF and the largest negative correlations of latent heat flux to HWF were specifically observed over the CN. This is a significantly different energy transfer regime due to less available soil moisture during the antecedent MAM and JJA. The higher sensible heat from dry soil could cause significant warming from the near surface (>2.0°C) to the lower troposphere (>1.5°C), and accumulated boundary layer heat could induce the significant patterns of higher geopotential height and enhance anticyclonic circulations (negative vorticity anomaly) at the midtroposphere. Results suggested a positive land-atmosphere feedback associated with heat waves and called attention to the need for region-specific climate adaptation planning.

  3. On the plasma-based growth of ‘flowing’ graphene sheets at atmospheric pressure conditions

    NASA Astrophysics Data System (ADS)

    Tsyganov, D.; Bundaleska, N.; Tatarova, E.; Dias, A.; Henriques, J.; Rego, A.; Ferraria, A.; Abrashev, M. V.; Dias, F. M.; Luhrs, C. C.; Phillips, J.

    2016-02-01

    A theoretical and experimental study on atmospheric pressure microwave plasma-based assembly of free standing graphene sheets is presented. The synthesis method is based on introducing a carbon-containing precursor (C2H5OH) through a microwave (2.45 GHz) argon plasma environment, where decomposition of ethanol molecules takes place and carbon atoms and molecules are created and then converted into solid carbon nuclei in the ‘colder’ nucleation zones. A theoretical model previously developed has been further updated and refined to map the particle and thermal fluxes in the plasma reactor. Considering the nucleation process as a delicate interplay between thermodynamic and kinetic factors, the model is based on a set of non-linear differential equations describing plasma thermodynamics and chemical kinetics. The model predictions were validated by experimental results. Optical emission spectroscopy was applied to detect the plasma emission related to carbon species from the ‘hot’ plasma zone. Raman spectroscopy, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy (XPS) techniques have been applied to analyze the synthesized nanostructures. The microstructural features of the solid carbon nuclei collected from the colder zones of plasma reactor vary according to their location. A part of the solid carbon was deposited on the discharge tube wall. The solid assembled from the main stream, which was gradually withdrawn from the hot plasma region in the outlet plasma stream directed to a filter, was composed by ‘flowing’ graphene sheets. The influence of additional hydrogen, Ar flow rate and microwave power on the concentration of obtained stable species and carbon-dicarbon was evaluated. The ratio of sp3/sp2 carbons in graphene sheets is presented. A correlation between changes in C2 and C number densities and sp3/sp2 ratio was found.

  4. Modeling the impact of vapor thymol concentration, temperature, and modified atmosphere condition on growth behavior of Salmonella on raw shrimp.

    PubMed

    Zhou, Siyuan; Sheen, Shiowshuh; Pang, Yu-Hsin; Liu, Linshu; Yam, Kit L

    2015-02-01

    Salmonella is a microorganism of concern on a global basis for raw shrimp. This research modeled the impact of vapor thymol concentration (0, 0.8, and 1.6 mg/liter), storage temperature (8, 12, and 16°C), and modified atmosphere condition (0.04 as in the natural atmosphere and 59.5% CO2) against the growth behavior of a Salmonella cocktail (six strains) on raw shrimp. Lag time (hour) and maximum growth rate (log CFU per gram per hour), chosen as two growth indicators, were obtained through DMFit software and then developed into polynomial as well as nonlinear modified secondary models (dimensional and/or dimensionless), consisting of two or even three impact factors in the equations. The models were validated, and results showed that the predictive values from both models demonstrated good matches to the observed experimental values, yet the prediction based on lag time was more accurate than maximum growth rate. The information will provide the food industry with insight into the potential safety risk of Salmonella growth on raw shrimp under stressed conditions. PMID:25710144

  5. Global atmospheric downward longwave radiation over land surface under all-sky conditions from 1973 to 2008

    NASA Astrophysics Data System (ADS)

    Wang, Kaicun; Liang, Shunlin

    2009-10-01

    In this article, we first evaluate two widely accepted methods to estimate global atmospheric downward longwave radiation (Ld) under both clear and cloudy conditions, using meteorological observations from 1996 to 2007 at 36 globally distributed sites, operated by the Surface Radiation Budget Network (SURFRAD), AmeriFlux, and AsiaFlux Projects. The breakdown of locations is North America (20 sites), Asia (12 sites), Australia (2 sites), Africa (1 site), and Europe (1 site). Latitudes for these sites range from 0° at the equator to ±50°; elevation ranges from 98 to 4700 m, and six different land cover types are represented (deserts, semideserts, croplands, grasslands, forests, and wetlands). The evaluation shows that the instantaneous Ld under all-sky conditions is estimated with an average bias of 2 W m-2 (0.6%), an average standard deviation (SD) of 20 W m-2 (6%), and an average correlation coefficient (R) of 0.86. Daily Ld under all-sky conditions is estimated with a SD of 12 W m-2 (3.7%) and an average R of 0.93. These results suggest that these two methods could be applied to most of the Earth's land surfaces. Accordingly, we applied them to globally available meteorological observations to estimate decadal variation in Ld. The decadal variations in global Ld under both clear and cloudy conditions at about 3200 stations from 1973 to 2008 are presented. We found that daily Ld increased at an average rate of 2.2 W m-2 per decade from 1973 to 2008. The rising trend results from increases in air temperature, atmospheric water vapor, and CO2 concentration.

  6. Pre-Emergency-Department Care-Seeking Patterns Are Associated with the Severity of Presenting Condition for Emergency Department Visit and Subsequent Adverse Events: A Timeframe Episode Analysis

    PubMed Central

    Yang, Nan-Ping; Lai, K. Robert; Huang, Hsin-Tsung

    2015-01-01

    Background Many patients treated in Emergency Department (ED) visits can be treated at primary or urgent care sectors, despite the fact that a number of ED visitors seek other forms of care prior to an ED visit. However, little is known regarding how the pre-ED activity episodes affect ED visits. Objectives We investigated whether care-seeking patterns involve the use of health care services of various types prior to ED visits and examined the associations of these patterns with the severity of the presenting condition for the ED visit (EDVS) and subsequent events. Methods This retrospective observational study used administrative data on beneficiaries of the universal health care insurance program in Taiwan. The service type, treatment capacity, and relative diagnosis were used to classify pre-ED visits into 8 care types. Frequent pattern analysis was used to identify sequential care-seeking patterns and to classify 667,183 eligible pre-ED episodes into patterns. Generalized linear models were developed using generalized estimating equations to examine the associations of these patterns with EDVS and subsequent events. Results The results revealed 17 care-seeking patterns. The EDVS and likelihood of subsequent events significantly differed among patterns. The ED severity index of patterns differ from patterns seeking directly ED care (coefficients ranged from -0.05 to 0.13), and the odds-ratios for the likelihood of subsequent ED visits and hospitalization ranged from 1.18 to 1.86 and 1.16 to 2.84, respectively. Conclusions The pre-ED care-seeking patterns differ in severity of presenting condition and subsequent events that may represent different causes of ED visit. Future health policy maker may adopt different intervention strategies for targeted population to reduce unnecessary ED visit effectively. PMID:26030278

  7. A STUDY ON LEGIONELLA PNEUMOPHILA, WATER CHEMISTRY, AND ATMOSPHERIC CONDITIONS IN COOLING TOWERS AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Smith, C.; Brigmon, R.

    2009-10-20

    concentrations when the dew point temperature was high--a summertime occurrence. However, analysis of the three years of Legionella monitoring data of the 14 different SRS Cooling Towers demonstrated that elevated concentrations are observed at all temperatures and seasons. The objective of this study is to evaluate the ecology of L. pneumophila including serogroups and population densities, chemical, and atmospheric data, on cooling towers at SRS to determine whether relationships exist among water chemistry, and atmospheric conditions. The goal is to more fully understand the conditions which inhibit or encourage L. pneumophila growth and supply this data and associated recommendations to SRS Cooling Tower personnel for improved management of operation. Hopefully this information could then be used to help control L. pneumophila growth more effectively in SRS cooling tower water.

  8. Kinetics and Mechanism of the Reaction of Hydoxyl Radicals with Acetonitrile under Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Hynes, A. J.; Wine, P. H.

    1997-01-01

    scheme to extract kinetic information about the adduct reations with O2 and branching ratios for OH regeneration. A plausible mechanism for OH regeneration in (2) involves OH addition to the nitrogen atom followed by O2 addition to the cyano carbon atom, isomeriazation and decomposition to D2CO + DOCN + OH. Our results suggest that the OH + CH3CN reaction occurs via a complex mechanism involving both bimolecular and termolecular pathways, analogous to the mechanisms for the the important atmospheric reactions of OH with CO and HNO3.

  9. A Method for Estimating the Bipolar Charge Distribution Variation on Aerosol Particles with Atmospheric Conditions

    NASA Astrophysics Data System (ADS)

    Leppä, J.; Gopalakrishnan, R.; Flagan, R. C.

    2014-12-01

    Many commonly used instruments that measure the aerosol particle number size distribution, such as Scanning Mobility Particle Sizer, are based on the following principle: The particle sample is brought to a steady-state charge distribution in a bipolar aerosol charger. The particles are then segregated according to their electrical mobilities using differential mobility analyzer, DMA. Finally, the concentration of the particles is measured using a condensation particle counter, CPC. To estimate the particle size distribution, the concentration data are then inverted using an algorithm that takes into account the steady-state charge distribution and the performance characteristics of the DMA and CPC. Considerable effort has gone into the characterization of the instruments used in these measurements. The charge distribution remains the greatest source of uncertainty in the mobility based size distribution measurements. The charge distribution depends, at least, on the properties of the ion and particle (radius, density, relative permittivity and number of charges), concentrations of negative and positive ions, temperature and pressure. With these values given, the collision frequencies of ions and particles can be modeled to determine the charge distribution, but that can be very time consuming. Instead, the charge distribution is usually estimated using a simple parameterization of the results of one such model. The collision process can, however, be described using only two dimensionless parameters, namely the diffusive Knudsen number, KnD, and the ratio of electric potential energy to thermal energy, ΨE. A given pair of KnD and ΨE may describe multiple collision conditions, but it defines a single value of dimensionless flux coefficient, H. This allows us to tabulate the values of KnD, ΨE and H, so that H can be determined by interpolation for conditions corresponding to the measurements. The charge distribution can readily be calculated from the interpolated

  10. Spectroelectrochemistry and modeling of enargite (Cu3AsS4) reactivity under atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Gow, Robert Nicholas Verne

    Raman spectroscopy has been a useful technology for fundamental studies in the mining industry. Surface changes through oxidation and reduction reactions can be monitored in-situ, allowing the changes to be monitored in real time. In conjunction with cyclic voltammetry, to change the conditions at which a mineral surface is subjected to, reaction and reaction conditions can be identified. The results can then be plotted to create a map similar to that of an EH-pH diagram. In this study, the copper arsenic sulfide mineral, enargite (Cu 3AsS4) was subjected to a series of tests. Relatively pure samples were obtained from Butte, MT and Quirivilca, Peru and used to create mineral electrodes. The electrodes were cycled over an EH range of -1000 to +1000 mV (vs SHE) at pH values ranging from 1 to 13. Changes to the surface of the mineral were identified by comparing Raman spectra to a mineral Raman database. Plotted results were then compared against mass-balanced EH-pH diagrams for the Cu-As-S-H2O system, created using the STABCAL thermodynamic calculation program. Ultimately, the EH-pH diagram is modified based on the results, and an updated version was created. The mass-balanced methodology is applied, in conjunction with Gibbs' phase rule, to an aqueous quaternary system. Variations in EH-pH diagrams of the Cu-As-S-H2O system based on slight changes in concentrations of copper, arsenic and sulfur are examined. Finally, a novel nano-graphene material was tested for its ability to adsorb arsenic. Arsenic remediation, downstream of an enargite leach, remains an unsolved issue. The nano-graphene platelets were not able to successfully reduce arsenic levels in solution below the EPA-required limitation of 10 ppb. A thermodynamic evaluation of the adsorption characterized the process as physisorption, and likely unsuitable for long-term arsenic storage. A functionalized version of the nano-graphene may enhance results.

  11. Transcriptomic analysis of fruit stored under cold conditions using controlled atmosphere in Prunus persica cv. "Red Pearl".

    PubMed

    Sanhueza, Dayan; Vizoso, Paula; Balic, Iván; Campos-Vargas, Reinaldo; Meneses, Claudio

    2015-01-01

    Cold storage (CS) can induce a physiological disorder known as chilling injury (CI) in nectarine fruits. The main symptom is mealiness that is perceived as non-juicy fruit by consumers. Postharvest treatments such as controlled atmosphere (CA; a high CO2 concentration and low O2) have been used under cold conditions to avoid this disorder. With the objective of exploring the mechanisms involved in the CA effect on mealiness prevention, we analyzed transcriptomic changes under six conditions of "Red Pearl" nectarines by RNA-Seq. Our analysis included just harvested nectarines, juicy non-stored fruits, fruits affected for CI after CS and fruits stored in a combination of CA plus CS without CI phenotype. Nectarines stored in cold conditions combined with CA treatment resulted in less mealiness; we obtained 21.6% of juice content compared with just CS fruits (7.7%; mealy flesh). RNA-Seq data analyses were carried out to study the gene expression for different conditions assayed. During ripening, we detected that nectarines exposed to CA treatment expressed a similar number of genes compared with fruits that were not exposed to cold conditions. Firm fruits have more differentially expressed genes than soft fruits, which suggest that most important changes occur during CS. On the other hand, gene ontology analysis revealed enrichment mainly in metabolic and cellular processes. Differentially expressed genes analysis showed that low O2 concentrations combined with cold conditions slows the metabolic processes more than just the cold storage, resulting mainly in the suppression of primary metabolism and cold stress response. This is a significant step toward unraveling the molecular mechanism that explains the effectiveness of CA as a tool to prevent CI development on fruits. PMID:26483806

  12. Synoptic-scale atmospheric conditions associated with flash flooding in watersheds of the Catskill Mountains, New York, USA

    NASA Astrophysics Data System (ADS)

    Teale, N. G.; Quiring, S. M.

    2015-12-01

    Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with

  13. Study of the dynamical behavior of the LIBS plasma under conditions of low atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Jijón, D.; Costa Vera, C.

    2011-09-01

    A new arrangement of 3 Langmuir probes to evaluate the electric potential and estimate the electron temperature in the LIBS plasma is introduced in this work. It consists of three nickel meshes (95% of transparency) on a basis for the sample in a vacuum chamber. The sample (a 50 cents coin) was analyzed at 9 different pressures (0.2, 0.4, 0.6, 0.8, 1, 2, 4, 6, 8 Torr). Measurements were made of the voltage signal induced in the electrodes relative to one another and to the sample. Information about the on-time and the duration of the plasma under the decreased pressure conditions can be extracted from these signals, which could in principle, be also correlated with the velocity of expansion of the plasma and the establishment of thermodynamical equilibrium in the system plasma-background gas. Additionally, we photographed the emitted light by LIBS plasma at maximum extension at different pressures by means of two digital cameras at the right angles to one another and to the laser beam. In each case, the expanded plasma contour was mathematically analyzed. In particular, the area of the plasma plume as recorded with the cameras was found to follow a simple relationship with the background pressure in a way not different from an ideal gas.

  14. Observations of the atmospheric boundary layer height under marine upstream flow conditions at a coastal site

    NASA Astrophysics Data System (ADS)

    PeñA, A.; Gryning, S.-E.; Hahmann, A. N.

    2013-02-01

    AbstractWe investigate several lidar-type instruments and methodologies for boundary layer height (BLH) estimation during 2 days at a coastal site for winds that experience marine upstream flow <span class="hlt">conditions</span>. Wavelet and profile fitting procedures on the aerosol backscatter signals from a ceilometer and an aerosol lidar reveal similar BLHs, but their agreement depends on the presence of clouds and the instrument signal, among others. BLHs derived by a threshold on the carrier-to-noise profiles of a wind lidar agree well with those derived by using a threshold on the backscatter profile of the ceilometer and are used as reference for a 10 day BLH intercomparison. Furthermore, the BLHs from the aerosol analysis are comparable to those derived from wind speed and direction profiles from combined mast/wind lidar measurements. The BLH derived from simulations performed with the Weather Research and Forecasting (WRF) model shows similar behavior compared to the lidar observations. The seasonal diurnal variation of the BLH for 2010, derived from the wind lidar and ceilometer thresholds, shows similar BLHs but generally higher values compared to that from WRF. No clear BLH diurnal variation is observed neither from the observations nor from the WRF model outputs, except in summer for the latter. Both observations and WRF model simulations reveal higher BLHs during autumn compared to spring time. These BLHs are used to evaluate the intra-annual variation and show high peaks in September, November, and February.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFM.S51D2709I&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFM.S51D2709I&link_type=ABSTRACT"><span id="translatedtitle">Constraining the Spatial and Temporal Variability of <span class="hlt">Atmospheric</span> <span class="hlt">Conditions</span> to Explore the Infrasound Detection of Volcanic Eruptions in Alaska</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iezzi, A. M.; Schwaiger, H. F.; Fee, D.; Haney, M. M.</p> <p>2015-12-01</p> <p>Alaska's over 50 historically active volcanoes span 2,500 kilometers, and their eruptions pose great threats to the aviation industry. This makes both prompt observations of explosion onsets and changes in intensity a necessity. Due to their expansive range and remoteness, these volcanoes are predominantly monitored by local seismic networks, remote observations including satellite imagery and infrasound sensors. Infrasound is an especially crucial tool in this area because infrasound data collection is not obstructed by frequent cloud cover (as in satellite imagery) and infrasound waves can travel hundreds to thousands of kilometers. However, infrasound station coverage is relatively sparse and strong wind and temperature gradients in the <span class="hlt">atmosphere</span> create multiple waveguides and shadow zones where the propagation of infrasound is enhanced and diminished, respectively. To accurately constrain volcanic source information and the long-range propagation of infrasound waves, a detailed characterization of the spatial and temporal variability of the <span class="hlt">atmosphere</span> is vital. These properties can be constrained using a ground-to-space model similar to that of Drob et al. (2003) based upon varied meteorological observations and applied to infrasound waves to model the propagation of infrasound. Here we present the first results of a re-analysis system constructed by the Alaska Volcano Observatory to accurately characterize and model long-range infrasound propagation from volcanic eruptions. We select a number of case studies to examine infrasound detections (or lack thereof) from recent eruptions of Alaskan volcanoes, including the November 2014 eruption of Pavlof Volcano and July 2015 eruption of Cleveland Volcano. Detailed examination of the acoustic propagation <span class="hlt">conditions</span> will provide additional insight into detection capability and eruption dynamics with future work aiming to implement real-time long-range infrasound propagation modeling.Drob, Douglas P., J. M. Picone</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3921220','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3921220"><span id="translatedtitle"><span class="hlt">Adverse</span> Socioeconomic <span class="hlt">Conditions</span> and Oocyst-Related Factors Are Associated with Congenital Toxoplasmosis in a Population-Based Study in Minas Gerais, Brazil</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Carellos, Ericka Viana Machado; de Andrade, Gláucia Manzan Queiroz; Vasconcelos-Santos, Daniel Vitor; Januário, José Nélio; Romanelli, Roberta Maia Castro; Abreu, Mery Natali Silva; da Silva, Fabiana Maria; Loures, Ivy Rosa Coelho; de Andrade, Juliana Queiroz; Caiaffa, Waleska Teixeira</p> <p>2014-01-01</p> <p>Objective Congenital toxoplasmosis is a public health problem in Brazil. This study aimed to determine risk factors associated with congenital toxoplasmosis in Minas Gerais which is the second largest Brazilian State based on number of inhabitants, and its territorial extension is larger than that of France. Methods: Population-based case-control study to assess the association between congenital toxoplasmosis and maternal exposure to infection risk factors. The study included mothers/children participating in the Minas Gerais Newborn Screening Program. The cases consisted of 175 mothers of infected children, and the controls consisted of 278 mothers of children without suspected infection. The associations were assessed through binomial logistic regression with p≤0.05. Results The variables associated with lower probability of toxoplasmosis were: older mother age (OR = 0.89; CI95% = 0.85–0.93), higher level of education (OR = 0.85; CI95% = 0.78–0.92), access to potable water (OR = 0.21; CI95% = 0.08–0.51), and home with flush toilet (OR = 0.18; CI95% = 0.04–078). The variables associated with higher probability of infection were: cats in the neighborhood (OR = 2.27; CI95% = 1.27–4.06), owning or visiting homes with domestic cats (OR = 1.90; CI95% = 1.09–3.31), handling the soil (OR = 2.29; CI95% = 1.32–3.96), and eating fresh meat not previously frozen (OR = 3.97; CI95% = 2.17–7.25). After stratification according region of residence (rural or urban/peri-urban), home with flush toilet and consumption of treated water were protective against the disease only in the rural stratum. Conclusions In Minas Gerais, congenital toxoplasmosis has been associated with poor socioeconomic <span class="hlt">conditions</span>. Considering maternal exposure to sources of Toxoplasma gondii, the predominating risk factors were those related to the ingestion of oocysts. It is expected that these results will contribute to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26408140','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26408140"><span id="translatedtitle">Behavior of Listeria monocytogenes in Sliced Ready-to-Eat Meat Products Packaged under Vacuum or Modified <span class="hlt">Atmosphere</span> <span class="hlt">Conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Menéndez, Rosa Ana; Rendueles, Eugenia; Sanz, José Javier; Capita, Rosa; García-Fernández, Camino</p> <p>2015-10-01</p> <p>The objective of this research was to determine the behavior of Listeria monocytogenes in three types of sliced ready-to-eat meat products packaged under vacuum or modified <span class="hlt">atmosphere</span> <span class="hlt">conditions</span> and stored at three temperatures. Slices of about 25 g of chorizo (a fermented dry pork sausage), jamón (cured ham), and cecina (a salted, dried beef product) were inoculated with L. monocytogenes NCTC 11994. Slices were packaged in a vacuum or in a modified <span class="hlt">atmosphere</span> (20% CO2, 80% N2). After packaging, samples were stored for 6 months at three temperatures: 3, 11, or 20°C. Microbiological analyses were performed after 0, 1, 7, 15, 30, 45, 90, and 180 days of storage. The type of meat product, the type of packaging, the temperature, and the day of storage all influenced microbial levels (P < 0.001). L. monocytogenes counts decreased throughout the course of storage in samples of chorizo (quick decrease) and jamón (gradual decrease). In cecina samples, counts of L. monocytogenes increased from day 0 to day 1 of storage and then remained constant until day 90 of the study. These results may be of use for enhancing the safety of these ready-to-eat meat product types. Additional evaluation of the behavior of L. monocytogenes in cecina is needed. PMID:26408140</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20752181','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20752181"><span id="translatedtitle">The characterization of coal liquefaction products obtained under an inert <span class="hlt">atmosphere</span> and catalytic <span class="hlt">conditions</span>. Part II: Soluble products</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karaca, H.</p> <p>2006-03-15</p> <p>Beypazari and Tuncbilek lignite were liquefied using two different catalyst methods physically mixing and impregnation. The liquefaction occurred under <span class="hlt">conditions</span> of inert <span class="hlt">atmosphere</span> and various process parameters. Solvent to coal ratio, pressure, catalyst type, catalyst concentration, temperature, and time were examined as process parameters. The most appropriate parameters for the total soluble products obtained by liquefaction of both lignites and for elemental analysis of preasphaltenes were determined as follows: 2/1 solvent to coal ratio; from 1.25 MPa to 2.50 MPa initial nitrogen pressure; Fe{sub 2}O{sub 3} and Mo(CO){sub 6} as catalyst types; 3% as catalyst concentration; 400{sup o}C as reaction temperature; and 60 min as reaction time. In general, fuel quality of both preasphaltene and total soluble products decreased as temperature increased above 400{sup o}C and reaction time exceeded 60 min. The fuel quality of the preasphaltenes and the total soluble products obtained under the catalytic <span class="hlt">conditions</span> and in the state of impregnation of catalyst onto coal is higher than under the noncatalytic <span class="hlt">conditions</span> and in the state of physically mixing of catalyst.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AdAtS..33..599S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AdAtS..33..599S"><span id="translatedtitle">Impact of <span class="hlt">atmospheric</span> and oceanic <span class="hlt">conditions</span> on the frequency and genesis location of tropical cyclones over the western North Pacific in 2004 and 2010</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Pan; Zhu, Jiang; Zhong, Zhong; Qi, Linlin; Wang, Xiaodan</p> <p>2016-05-01</p> <p>This study examines the impact of <span class="hlt">atmospheric</span> and oceanic <span class="hlt">conditions</span> during May-August of 2004 and 2010 on the frequency and genesis location of tropical cyclones over the western North Pacific. Using the WRF model, four numerical experiments were carried out based on different <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> and SST forcing. The numerical experiments indicated that changes in <span class="hlt">atmospheric</span> and oceanic <span class="hlt">conditions</span> greatly affect tropical cyclone activity, and the roles of <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> are slightly greater than oceanic <span class="hlt">conditions</span>. Specifically, the total number of tropical cyclones was found to be mostly affected by <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>, while the distribution of tropical cyclone genesis locations was mainly related to oceanic <span class="hlt">conditions</span>, especially the distribution of SST. In 2010, a warmer SST occurred west of 140°E, with a colder SST east of 140°E. On the one hand, the easterly flow was enhanced through the effect of the increase in the zonal SST gradient. The strengthened easterly flow led to an anomalous boundary layer divergence over the region to the east of 140°E, which suppressed the formation of tropical cyclones over this region. On the other hand, the colder SST over the region to the east of 140°E led to a colder low-level air temperature, which resulted in decreased CAPE and static instability energy. The decrease in thermodynamic energy restricted the generation of tropical cyclones over the same region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApSS..378..540M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApSS..378..540M&link_type=ABSTRACT"><span id="translatedtitle">3-D laser confocal microscopy study of the oxidation of NdFeB magnets in <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meakin, J. P.; Speight, J. D.; Sheridan, R. S.; Bradshaw, A.; Harris, I. R.; Williams, A. J.; Walton, A.</p> <p>2016-08-01</p> <p>Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.- computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd2O3 and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10-13 cm2/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth observations at elevated temperatures in the literature. This indicates that the growth of the room temperature oxidation products are likely defect enhanced processes at the NdFeB triple junctions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H33G1407W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H33G1407W"><span id="translatedtitle">Dissolved Noble Gases in Rainwater, Southern Michigan - Evidence for Lack of Rainwater Equilibration with the <span class="hlt">Atmosphere</span> at Surface <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Warrier, R. B.; Castro, M.; Hall, C. M.</p> <p>2012-12-01</p> <p><span class="hlt">Atmospheric</span> noble gases dissolved in groundwater have been extensively used to reconstruct the past climate. A key assumption of the noble gas thermometer is that rainwater is in equilibrium with ground air when it reaches the water table. However, our recent study conducted in the Galapagos Islands showed that dissolved <span class="hlt">atmospheric</span> noble gas concentrations in high-altitude spring samples display high apparent recharge altitudes, cold apparent temperatures and a unique, previously unknown noble gas pattern. In addition to <span class="hlt">atmospheric</span> He excesses, this pattern displays Ne, Kr, and Xe depletion together with relative Ar enrichment. We hypothesized that this unexpected noble gas pattern resulted from the combined effect of a lack of rainwater equilibration at high altitudes in the <span class="hlt">atmosphere</span> and the impact of fog droplets on noble gas concentrations in groundwater. To understand the origin of this previously unknown noble gas pattern, we analyzed He, Ne, Ar, Kr and Xe dissolved in 12 rainwater samples resulting from the passage of both warm and cold fronts in southern Michigan. Preliminary results show that all samples present <span class="hlt">atmospheric</span> He excesses, ranging between 1% and 29% with respect to air saturated water (ASW) for corresponding measured temperature and altitude values at the time and location of sampling. In addition, these samples can be subdivided into two groups with distinct patterns. The first group displays a pattern remarkably similar to the unique anomalous pattern observed in high-altitude spring samples in the Galapagos Islands with relative Ar enrichment and Ne, Kr, and Xe depletion. The second group displays a mass-dependent pattern with greater depletion of the heavier noble gases Kr and Xe as compared to the lighter noble gases Ne and Ar. The first group of rainwater samples was mostly collected during the passage of warm fronts, which are typically associated with light, steady precipitation and gradual adiabatic uplift of air masses as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3757014','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3757014"><span id="translatedtitle">H. pylori CagL-Y58/E59 Prime Higher Integrin α5β1 in <span class="hlt">Adverse</span> pH <span class="hlt">Condition</span> to Enhance Hypochlorhydria Vicious Cycle for Gastric Carcinogenesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Hsiao-Bai; Chang, Wei-Lun; Sheu, Bor-Shyang</p> <p>2013-01-01</p> <p>Background/Aims H. pylori CagL amino acid polymorphisms such as Y58/E59 can increase integrin α5β1 expression and gastric cancer risk. Hypochlorhydria during chronic H. pylori infection promotes gastric carcinogenesis. The study test whether CagL-Y58/E59 isolates may regulate integrin α5β1 to translocate CagA via the type IV secretory system even under <span class="hlt">adverse</span> pH <span class="hlt">conditions</span>, and whether the integrin α5β1 expression primed by H. pylori is a pH-dependent process involving hypochlorhydria in a vicious cycle to promote gastric carcinogenesis. Methods The expressions of integrin α5 and β1, CagA phosphorylation, IL-8, FAK, EGFR, and AKT activation of AGS cells exposed to CagL-Y58/E59 H. pylori, isogenic mutants, and different H. pylori CagL amino acid replacement mutants under different pH values were determined. Differences in the pepsinogen I/II ratio (indirectly indicating gastric acidity) and gastric integrin α5β1 expression were compared among the 172 H. pylori-infected patients with different cancer risks. Results Even under <span class="hlt">adversely</span> low pH <span class="hlt">condition</span>, H. pylori CagL-Y58/E59 still keep active integrin β1 with stronger binding affinity, CagA translocation, IL-8, FAK, EGFR, and AKT activation than the other mutants (p<0.05). The in vitro assay revealed higher priming of integrin α5β1 by H. pylori under elevated pH as hypochlorhydria (p<0.05). In the H. pylori-infected patients, the gastric integrin α5β1 expressions were higher in those with pepsinogen I/II ratio <6 than in those without (p<0.05). Conclusions H. pylori CagL-Y58/E59 prime higher integrin under <span class="hlt">adverse</span> pH and may involve to enhance hypochlorhydria vicious cycle for gastric carcinogenesis, and thus require an early eradication. PMID:24009701</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012DPS....4441606S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012DPS....4441606S"><span id="translatedtitle">Laboratory Measurments of the 3.7-20 cm Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide under Simulated <span class="hlt">Conditions</span> for the Deep <span class="hlt">Atmosphere</span> of Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steffes, Paul G.; Barisich, C.</p> <p>2012-10-01</p> <p>In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA) and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep <span class="hlt">atmospheric</span> absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide <span class="hlt">atmosphere</span> under <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho et al., JGR 71, 1966), no measurements of the centimeter-wavelength properties of any Venus <span class="hlt">atmospheric</span> constituent have been conducted under <span class="hlt">conditions</span> characteristic of the deep <span class="hlt">atmosphere</span> (pressures from 10-92 Bars and temperatures from 400-700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7-20 cm are now being conducted under simulated <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus, using a new high-pressure system. Initial results from this measurement campaign conducted at 430 K and at pressures up to 92 Bars will be presented. This work is supported by the NASA Planetary <span class="hlt">Atmospheres</span> Program under Grant NNX11AD66G.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3589L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3589L"><span id="translatedtitle"><span class="hlt">Atmospheric</span> Dispersion Modeling of 137Cs generated from Nuclear Spent Fuel under Hypothetic Accidental <span class="hlt">Condition</span> in the BNPP Area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Jongkuk; Lee, Kwan-Hee; Yook, Daesik; Kim, Sung Il; Lee, Byung Soo</p> <p>2016-04-01</p> <p>This study presents the results of <span class="hlt">atmosphere</span> dispersion modeling using CALPUFF code that are based on computational simulation to evaluate the environmental characteristics of the Barakah nuclear power plant (BNPP) in west area of UAE. According to meteorological data analysis (2012~2013), the winds from the north(7.68%) and west(9.05%) including NNW(41.63%), NW(28.55%), and WNW(6.31%) winds accounted for more than 90% of the wind directions. East(0.2%) and south(0.6%) direction wind, including ESE(0.31%), SE(0.38%), and SSE(0.38%) were rarely distributed during the simulation period. Seasonal effects were not showed. However, a discrepancy in the tendency between daytime and night-time was observed. Approximately 87% of the wind speed was distributed below 5.4m/s (17%, 47% and 23% between the speeds of 0.5-1.8m/s 1.8-3.3m/s and 3.3-5.4m/s, respectively) during the annual period. Seasonal wind speed distribution results presented very similar pattern of annual distribution. Wind speed distribution of day and night, on the other hand, had a discrepancy with annual modeling results than seasonal distribution in some sections. The results for high wind speed (more than 10.8m/s) showed that this wind blew from the west. This high wind speed is known locally as the 'Shamal', which occurs rarely, lasting one or two days with the strongest winds experienced in association with gust fronts and thunderstorms. Six variations of cesium-137 (137Cs) dispersion test were simulated under hypothetic severe accidental <span class="hlt">condition</span>. The 137Cs dispersion was strongly influenced by the direction and speed of the main wind. From the test cases, east-south area of the BNPP site was mainly influenced by 137Cs dispersion. A virtual receptor was set and calculated for observation of the 137Cs movement and accumulation. Surface roughness tests were performed for the analysis of topographic <span class="hlt">conditions</span>. According to the surface <span class="hlt">condition</span>, there are various surface roughness length. Four types</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24804022','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24804022"><span id="translatedtitle">Shelf life of air and modified <span class="hlt">atmosphere</span>-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cyprian, Odoli; Lauzon, Hélène L; Jóhannsson, Ragnar; Sveinsdóttir, Kolbrún; Arason, Sigurjón; Martinsdóttir, Emilía</p> <p>2013-03-01</p> <p>Optimal packaging and storage <span class="hlt">conditions</span> for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and -1°C. Sensory analysis of cooked samples revealed a shelf life of 13-15 days for air-packaged fillets during storage at 1°C and 20 days at -1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g(-1). In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (<log 8 CFU g(-1)) after 23 days of storage at both 1°C and -1°C. However, modified <span class="hlt">atmosphere</span> (MA) packaging negatively affected color characteristics of the fillets soon after packaging (day 6). Color is an important indicator of tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at -1°C storage temperature was the optimal <span class="hlt">condition</span> for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study. PMID:24804022</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711752S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711752S"><span id="translatedtitle"><span class="hlt">Atmospheric</span> ice crystals over complex terrain: Pure ice cloud <span class="hlt">conditions</span> observed in CLACE2013 at Jungfraujoch, Switzerland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schlenczek, Oliver; Fugal, Jacob P.; Bower, Keith N.; Crosier, Jonathan; Flynn, Michael J.; Henneberger, Jan; Krieger, Ulrich K.; Lloyd, Gary; Borrmann, Stephan</p> <p>2015-04-01</p> <p>The CLACE2013 field campaign took place in January and February 2013 at the High Alpine Research Station, Jungfraujoch, in Switzerland. During this field campaign some events of <span class="hlt">atmospheric</span> ice crystals in the absence of supercooled water droplets were observed. These included precipitation events from a cloud above and also ice crystals which likely formed in-situ under ice supersaturated <span class="hlt">conditions</span> similar to "diamond-dust" events. From each event, approx. 1 hour of holographic measurements has been analysed (~1800 images with a 36x24x350 mm3 or ~0.3 L sample volume each). Ice crystals are detected and classified according to their shape to distinguish between different particle habit classes (e.g. columns and needles, plates, irregular crystals) and with this method, drifting snow and ice particles formed in-situ can be distinguished to a certain degree. The major axis length of detected ice particles varied between some tens of microns up to a few millimetres. Size distributions will be shown partitioned by crystal habit. Preliminary results show these ice particles appear similar to diamond dust events observed in Antarctica. For clarification of the meteorological <span class="hlt">conditions</span>, we use the meteorological parameters from several instruments measured at the site as well as data from additional cloud hydrometeor probes and a ceilometer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title29-vol7/pdf/CFR-2010-title29-vol7-sec1918-94.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title29-vol7/pdf/CFR-2010-title29-vol7-sec1918-94.pdf"><span id="translatedtitle">29 CFR 1918.94 - Ventilation and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> (See also § 1918.2, definitions of Hazardous cargo...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>..., definitions of Hazardous cargo, materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). 1918.94 Section 1918..., materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). (a) Ventilation with respect to carbon monoxide..., the employer shall ensure that the <span class="hlt">atmosphere</span> is tested as frequently as needed to prevent...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title29-vol7/pdf/CFR-2012-title29-vol7-sec1918-94.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title29-vol7/pdf/CFR-2012-title29-vol7-sec1918-94.pdf"><span id="translatedtitle">29 CFR 1918.94 - Ventilation and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> (See also § 1918.2, definitions of Hazardous cargo...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>..., definitions of Hazardous cargo, materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). 1918.94 Section 1918..., materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). (a) Ventilation with respect to carbon monoxide..., the employer shall ensure that the <span class="hlt">atmosphere</span> is tested as frequently as needed to prevent...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title29-vol7/pdf/CFR-2014-title29-vol7-sec1918-94.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title29-vol7/pdf/CFR-2014-title29-vol7-sec1918-94.pdf"><span id="translatedtitle">29 CFR 1918.94 - Ventilation and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> (See also § 1918.2, definitions of Hazardous cargo...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>..., definitions of Hazardous cargo, materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). 1918.94 Section 1918..., materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). (a) Ventilation with respect to carbon monoxide..., the employer shall ensure that the <span class="hlt">atmosphere</span> is tested as frequently as needed to prevent...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title29-vol7/pdf/CFR-2013-title29-vol7-sec1918-94.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title29-vol7/pdf/CFR-2013-title29-vol7-sec1918-94.pdf"><span id="translatedtitle">29 CFR 1918.94 - Ventilation and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> (See also § 1918.2, definitions of Hazardous cargo...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>..., definitions of Hazardous cargo, materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). 1918.94 Section 1918..., materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). (a) Ventilation with respect to carbon monoxide..., the employer shall ensure that the <span class="hlt">atmosphere</span> is tested as frequently as needed to prevent...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title29-vol7/pdf/CFR-2011-title29-vol7-sec1918-94.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title29-vol7/pdf/CFR-2011-title29-vol7-sec1918-94.pdf"><span id="translatedtitle">29 CFR 1918.94 - Ventilation and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> (See also § 1918.2, definitions of Hazardous cargo...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>..., definitions of Hazardous cargo, materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). 1918.94 Section 1918..., materials, substance or <span class="hlt">atmosphere</span> and Ro-Ro operations). (a) Ventilation with respect to carbon monoxide..., the employer shall ensure that the <span class="hlt">atmosphere</span> is tested as frequently as needed to prevent...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AMTD....812475F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AMTD....812475F"><span id="translatedtitle">Investigation of potential interferences in the detection of <span class="hlt">atmospheric</span> ROx radicals by laser-induced fluorescence under dark <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, H.; Tan, Z.; Hofzumahaus, A.; Broch, S.; Dorn, H.-P.; Holland, F.; Künstler, C.; Gomm, S.; Rohrer, F.; Schrade, S.; Tillmann, R.; Wahner, A.</p> <p>2015-11-01</p> <p>Direct detection of highly reactive, <span class="hlt">atmospheric</span> hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime <span class="hlt">conditions</span>. For laboratory experiments, the inlet of the instrument was overflown by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm-3 OH for a mixing ratio of 5 ppbv acetone. Under most <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>, this interference is negligible. No significant interferences were found for <span class="hlt">atmospheric</span> concentrations of reactants</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AMT.....9.1431F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AMT.....9.1431F&link_type=ABSTRACT"><span id="translatedtitle">Investigation of potential interferences in the detection of <span class="hlt">atmospheric</span> ROx radicals by laser-induced fluorescence under dark <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, Hendrik; Tan, Zhaofeng; Hofzumahaus, Andreas; Broch, Sebastian; Dorn, Hans-Peter; Holland, Frank; Künstler, Christopher; Gomm, Sebastian; Rohrer, Franz; Schrade, Stephanie; Tillmann, Ralf; Wahner, Andreas</p> <p>2016-04-01</p> <p>Direct detection of highly reactive, <span class="hlt">atmospheric</span> hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low-pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime <span class="hlt">conditions</span>. For laboratory experiments, the inlet of the instrument was over flowed by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm-3 OH for a mixing ratio of 5 ppbv acetone. Under most <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>, this interference is negligible. No significant interferences were found for <span class="hlt">atmospheric</span> concentrations of reactants</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1815033H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1815033H"><span id="translatedtitle">Trace gas retrieval for limb DOAS under changing <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>: The X-gas scaling method vs optimal estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hueneke, Tilman; Grossmann, Katja; Knecht, Matthias; Raecke, Rasmus; Stutz, Jochen; Werner, Bodo; Pfeilsticker, Klaus</p> <p>2016-04-01</p> <p>Changing <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> during DOAS measurements from fast moving aircraft platforms pose a challenge for trace gas retrievals. Traditional inversion techniques to retrieve trace gas concentrations from limb scattered UV/vis spectroscopy, like optimal estimation, require a-priori information on Mie extinction (e.g., aerosol concentration and cloud cover) and albedo, which determine the <span class="hlt">atmospheric</span> radiative transfer. In contrast to satellite applications, cloud filters can not be applied because they would strongly reduce the usable amount of expensively gathered measurement data. In contrast to ground-based MAX-DOAS applications, an aerosol retrieval based on O4 is not able to constrain the radiative transfer in air-borne applications due to the rapidly decreasing amount of O4 with altitude. Furthermore, the assumption of a constant cloud cover is not valid for fast moving aircrafts, thus requiring 2D or even 3D treatment of the radiative transfer. Therefore, traditional techniques are not applicable for most of the data gathered by fast moving aircraft platforms. In order to circumvent these limitations, we have been developing the so-called X-gas scaling method. By utilising a proxy gas X (e.g. O3, O4, …), whose concentration is either a priori known or simultaneously in-situ measured as well as remotely measured, an effective absorption length for the target gas is inferred. In this presentation, we discuss the strengths and weaknesses of the novel approach along with some sample cases. A particular strength of the X-gas scaling method is its insensitivity towards the aerosol abundance and cloud cover as well as wavelength dependent effects, whereas its sensitivity towards the profiles of both gases requires a priori information on their shapes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AGUFM.A11G..07D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AGUFM.A11G..07D&link_type=ABSTRACT"><span id="translatedtitle">Response of the Tropical <span class="hlt">Atmospheric</span> Circulation to Glacial Boundary <span class="hlt">Conditions</span> Simulated by an Ensemble of Coupled Climate Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>di Nezio, P. N.; Clement, A. C.; Vecchi, G. A.</p> <p>2009-12-01</p> <p>The response of the tropical <span class="hlt">atmospheric</span> circulation to Last Glacial Maximum (LGM) boundary <span class="hlt">conditions</span> is analyzed using an ensemble of coordinated climate model experiments performed for the Paleoclimate Modelling Intercomparison Project Phase II. The multi-model changes in the surface circulation of the Tropical Pacific are dominated by cross-equatorial winds flowing from the Northern hemisphere (NH) to the Southern hemisphere (SH) along with a strengthening of the easterlies over the equatorial Pacific. The anomalous cross-equatorial winds have been typically associated with an anomalous Hadley cell with the ascending branch in the SH and the descending branch in the NH compensating changes in <span class="hlt">atmospheric</span> heat transport. However, in this ensemble of coupled General Circulation Models (GCMs) the changes in the tropical circulation result from different forcing in each hemisphere. In the NH hemisphere the changes are dominated by the topography of the ice sheets, while in the SH the changes result from cooling due to decreased CO2. The changes in circulation due to the topography of the icesheets are diagnosed using a steady s-coordinate primitive equation model linearized about a zonally symmetric basic state that solves for the eddy component of the circulation. The solutions from this model for each GCM indicate that differences in the simulation of the mean climate result in differences in the response to LGM topography. The multi-model <span class="hlt">atmospheric</span> response in the NH is analogous to the expansion of the Aleutian low during boreal winter in the present climate, when the NH subtropical high is squeezed southeastward by an expanded Aleutian low. In the SH the models simulate an eastward expansion of the South Pacific Convergence Zone and contraction of the eastern Pacific dry zone consistent with reduced subsidence associated with a slowing down of the SH Hadley cell. This eastward shift in the mean climatology results in weakened trade winds. In addition to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23721064','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23721064"><span id="translatedtitle">Photooxidation of ammonia on TiO2 as a source of NO and NO2 under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kebede, Mulu A; Varner, Mychel E; Scharko, Nicole K; Gerber, R Benny; Raff, Jonathan D</p> <p>2013-06-12</p> <p>Ammonia is the most abundant reduced nitrogen species in the <span class="hlt">atmosphere</span> and an important precursor in the industrial-scale production of nitric acid. A coated-wall flow tube coupled to a chemiluminescence NOx analyzer was used to study the kinetics of NH3 uptake and NOx formation from photochemistry initiated on irradiated (λ > 290 nm) TiO2 surfaces under <span class="hlt">atmospherically</span> relevant <span class="hlt">conditions</span>. The speciation of NH3 on TiO2 surfaces in the presence of surface-adsorbed water was determined using diffuse reflection infrared Fourier transform spectroscopy. The uptake kinetics exhibit an inverse dependence on NH3 concentration as expected for reactions proceeding via a Langmuir-Hinshelwood mechanism. The mechanism of NOx formation is shown to be humidity dependent: Water-catalyzed reactions promote NOx formation up to a relative humidity of 50%. Less NOx is formed above 50%, where increasing amounts of adsorbed water may hinder access to reactive sites, promote formation of unreactive NH4(+), and reduce oxidant levels due to higher OH radical recombination rates. A theoretical study of the reaction between the NH2 photoproduct and O2 in the presence of H2O supports the experimental conclusion that NOx formation is catalyzed by water. Calculations at the MP2 and CCSD(T) level on the bare NH2 + O2 reaction and the reaction of NH2 + O2 in small water clusters were carried out. Solvation of NH2OO and NHOOH intermediates likely facilitates isomerization via proton transfer along water wires, such that the steps leading ultimately to NO are exothermic. These results show that photooxidation of low levels of NH3 on TiO2 surfaces represents a source of <span class="hlt">atmospheric</span> NOx, which is a precursor to ozone. The proposed mechanism may be broadly applicable to dissociative chemisorption of NH3 on other metal oxide surfaces encountered in rural and urban environments and employed in pollution control applications (selective catalytic oxidation/reduction) and during some industrial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013DPS....4520203S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013DPS....4520203S"><span id="translatedtitle">Models for the Centimeter-Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide based on Laboratory Measurements Conducted under Simulated <span class="hlt">Conditions</span> for the Deep <span class="hlt">Atmosphere</span> of Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steffes, Paul G.; Shahan, P. M.</p> <p>2013-10-01</p> <p>In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA), and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep <span class="hlt">atmospheric</span> absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide <span class="hlt">atmosphere</span> under <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus is required for proper interpretation. Initial measurements of the centimeter-wavelength (3.7-20 cm) of SO2 and CO2 under simulated <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus, conducted using a new high-pressure system operating at 430 K and at pressures up to 92 Bars, were presented by Steffes and Barisich (DPS-2012, B.A.A.S., v.44, p.241). Over the past year, we have completed this measurement campaign for temperatures up to 550 K, so as to better understand the effects of SO2 and CO2 on the microwave emission from the Venus boundary layer. Results indicate that the model for the centimeter-wavelength opacity from pure CO2 (developed over 40 years ago -- Ho et al., JGR 71, 1966), is valid over the entire centimeter-wavelength range under simulated <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus. Additionally, the laboratory results indicate that the model for the centimeter-wavelength opacity of SO2 in a CO2 <span class="hlt">atmosphere</span> from Suleiman et al. (JGR-Planets, 101, Feb. 1996) can reliably be used under <span class="hlt">conditions</span> of the deep <span class="hlt">atmosphere</span> of Venus with the modifications described in this paper . This work is supported by the NASA Planetary <span class="hlt">Atmospheres</span> Program under Grant NNX11AD66G.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920044628&hterms=solstice&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolstice','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920044628&hterms=solstice&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolstice"><span id="translatedtitle">Simulation of the zonal mean climatology of the middle <span class="hlt">atmosphere</span> with a three-dimensional spectral model for solstice and equinox <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Akmaev, R. A.; Fomichev, V. I.; Gavrilov, N. M.; Shved, G. M.</p> <p>1992-01-01</p> <p>A 3D spectral model was used to simulate the zonal mean state of the middle <span class="hlt">atmosphere</span> for solstice and equinox <span class="hlt">conditions</span>. The model incorporates realistic parameterizations of <span class="hlt">atmospheric</span> infrared cooling and a gravity wave formulation based on a combination of Lindzen's (1981) and Matsuno's (1982) approaches. The temperature distributions for both seasons and the zonal wind distribution for solstice are found to be in satisfactory agreement with the empirical model of Fleming et al. (1988). Net vertical fluxes of horizontal momentum are in good agreement with systematic observations of gravity waves in the middle <span class="hlt">atmosphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4815K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4815K"><span id="translatedtitle"><span class="hlt">Atmospheric</span> <span class="hlt">conditions</span> associated with high and low summertime ozone levels in the boundary layer over some eastern Mediterranean airports</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kalabokas, Pavlos D.; Thouret, Valerie; Cammas, Jean-Pierre; Volz-Thomas, Andreas; Boulanger, Damien; Repapis, Christos C.</p> <p>2013-04-01</p> <p>Thanks to the vertical <span class="hlt">atmospheric</span> measurements of the MOZAIC program, enhanced ozone mixing ratios in the lower troposphere over the Eastern Mediterranean have been found, frequently exceeding the 60 ppb, 8-h EU air quality standard, whereas ozone between 700 hPa and 400 hPa was only slightly (3-5 ppb, 5-10%) higher than over Central Europe. Also, the examination of the highest and lowest ozone levels in the lower troposphere (1.5-5 km) over some airports in the Eastern Mediterranean area showed the lower-tropospheric ozone variability over there is controlled mainly by the synoptic meteorological <span class="hlt">conditions</span>, combined with local topographical and meteorological features. In particular, the highest ozone concentrations in the lower troposphere and subsequently in the boundary layer in the area are associated with large scale subsidence of ozone rich air masses from the upper troposphere under anticyclonic <span class="hlt">conditions</span> while the lowest ozone concentrations are associated with low pressure <span class="hlt">conditions</span> inducing uplifting of boundary layer air, poor in ozone and rich in relative humidity, to the lower troposphere. In order to further evaluate the observed high rural ozone levels during summertime, vertical summer ozone profiles measured by MOZAIC in the period 1994-2008 over the Eastern Mediterranean basin (Cairo, Tel-Aviv, Heraklion, Rhodes, Antalya) are analyzed, focusing in the boundary layer (0-1.5 km). First, vertical profiles collected during extreme days with very high or very low tropospheric ozone mixing ratios are examined. Also, the average profiles of ozone, relative humidity, carbon monoxide, vertical temperature gradient and wind speed corresponding to the 7% highest and the 7% lowest ozone mixing ratios for the height layers of 0-500m, 500-1000m and 1000-1500m for Cairo and Tel-Aviv are examined along with the corresponding composite maps of geopotential heights at 850 hPa and 925 hPa. In addition, analyses of backward trajectories, using the FLEXPART model</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7513L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7513L"><span id="translatedtitle">Rainfall Downscaling <span class="hlt">Conditional</span> on Upper-air <span class="hlt">Atmospheric</span> Predictors: Improved Assessment of Rainfall Statistics in a Changing Climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langousis, Andreas; Mamalakis, Antonis; Deidda, Roberto; Marrocu, Marino</p> <p>2015-04-01</p> <p>To improve the level skill of Global Climate Models (GCMs) and Regional Climate Models (RCMs) in reproducing the statistics of rainfall at a basin level and at hydrologically relevant temporal scales (e.g. daily), two types of statistical approaches have been suggested. One is the statistical correction of climate model rainfall outputs using historical series of precipitation. The other is the use of stochastic models of rainfall to <span class="hlt">conditionally</span> simulate precipitation series, based on large-scale <span class="hlt">atmospheric</span> predictors produced by climate models (e.g. geopotential height, relative vorticity, divergence, mean sea level pressure). The latter approach, usually referred to as statistical rainfall downscaling, aims at reproducing the statistical character of rainfall, while accounting for the effects of large-scale <span class="hlt">atmospheric</span> circulation (and, therefore, climate forcing) on rainfall statistics. While promising, statistical rainfall downscaling has not attracted much attention in recent years, since the suggested approaches involved complex (i.e. subjective or computationally intense) identification procedures of the local weather, in addition to demonstrating limited success in reproducing several statistical features of rainfall, such as seasonal variations, the distributions of dry and wet spell lengths, the distribution of the mean rainfall intensity inside wet periods, and the distribution of rainfall extremes. In an effort to remedy those shortcomings, Langousis and Kaleris (2014) developed a statistical framework for simulation of daily rainfall intensities <span class="hlt">conditional</span> on upper air variables, which accurately reproduces the statistical character of rainfall at multiple time-scales. Here, we study the relative performance of: a) quantile-quantile (Q-Q) correction of climate model rainfall products, and b) the statistical downscaling scheme of Langousis and Kaleris (2014), in reproducing the statistical structure of rainfall, as well as rainfall extremes, at a</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A23A0173W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A23A0173W"><span id="translatedtitle">Optimized circulation and weather type classifications relating large-scale <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> to local PM10 concentrations in Bavaria</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weitnauer, C.; Beck, C.; Jacobeit, J.</p> <p>2013-12-01</p> <p>In the last decades the critical increase of the emission of air pollutants like nitrogen dioxide, sulfur oxides and particulate matter especially in urban areas has become a problem for the environment as well as human health. Several studies confirm a risk of high concentration episodes of particulate matter with an aerodynamic diameter < 10 μm (PM10) for the respiratory tract or cardiovascular diseases. Furthermore it is known that local meteorological and large scale <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> are important influencing factors on local PM10 concentrations. With climate changing rapidly, these connections need to be better understood in order to provide estimates of climate change related consequences for air quality management purposes. For quantifying the link between large-scale <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> and local PM10 concentrations circulation- and weather type classifications are used in a number of studies by using different statistical approaches. Thus far only few systematic attempts have been made to modify consisting or to develop new weather- and circulation type classifications in order to improve their ability to resolve local PM10 concentrations. In this contribution existing weather- and circulation type classifications, performed on daily 2.5 x 2.5 gridded parameters of the NCEP/NCAR reanalysis data set, are optimized with regard to their discriminative power for local PM10 concentrations at 49 Bavarian measurement sites for the period 1980 to 2011. Most of the PM10 stations are situated in urban areas covering urban background, traffic and industry related pollution regimes. The range of regimes is extended by a few rural background stations. To characterize the correspondence between the PM10 measurements of the different stations by spatial patterns, a regionalization by an s-mode principal component analysis is realized on the high-pass filtered data. The optimization of the circulation- and weather types is implemented using two representative</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......186H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......186H"><span id="translatedtitle">The application of tomographic reconstruction techniques to ill-<span class="hlt">conditioned</span> inverse problems in <span class="hlt">atmospheric</span> science and biomedical imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hart, Vern Philip, II</p> <p></p> <p>A methodology is presented for creating tomographic reconstructions from various projection data, and the relevance of the results to applications in <span class="hlt">atmospheric</span> science and biomedical imaging is analyzed. The fundamental differences between transform and iterative methods are described and the properties of the imaging configurations are addressed. The presented results are particularly suited for highly ill-<span class="hlt">conditioned</span> inverse problems in which the imaging data are restricted as a result of poor angular coverage, limited detector arrays, or insufficient access to an imaging region. The class of reconstruction algorithms commonly used in sparse tomography, the algebraic reconstruction techniques, is presented, analyzed, and compared. These algorithms are iterative in nature and their accuracy depends significantly on the initialization of the algorithm, the so-called initial guess. A considerable amount of research was conducted into novel initialization techniques as a means of improving the accuracy. The main body of this paper is comprised of three smaller papers, which describe the application of the presented methods to <span class="hlt">atmospheric</span> and medical imaging modalities. The first paper details the measurement of mesospheric airglow emissions at two camera sites operated by Utah State University. Reconstructions of vertical airglow emission profiles are presented, including three-dimensional models of the layer formed using a novel fanning technique. The second paper describes the application of the method to the imaging of polar mesospheric clouds (PMCs) by NASA's Aeronomy of Ice in the Mesosphere (AIM) satellite. The contrasting elements of straight-line and diffusive tomography are also discussed in the context of ill-<span class="hlt">conditioned</span> imaging problems. A number of developing modalities in medical tomography use near infrared light, which interacts strongly with biological tissue and results in significant optical scattering. In order to perform tomography on the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24188183','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24188183"><span id="translatedtitle">Mineral oxides change the <span class="hlt">atmospheric</span> reactivity of soot: NO2 uptake under dark and UV irradiation <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Romanias, Manolis N; Bedjanian, Yuri; Zaras, Aristotelis M; Andrade-Eiroa, Aurea; Shahla, Roya; Dagaut, Philippe; Philippidis, Aggelos</p> <p>2013-12-01</p> <p>The heterogeneous reactions between trace gases and aerosol surfaces have been widely studied over the past decades, revealing the crucial role of these reactions in <span class="hlt">atmospheric</span> chemistry. However, existing knowledge on the reactivity of mixed aerosols is limited, even though they have been observed in field measurements. In the current study, the heterogeneous interaction of NO2 with solid surfaces of Al2O3 covered with kerosene soot was investigated under dark <span class="hlt">conditions</span> and in the presence of UV light. Experiments were performed at 293 K using a low-pressure flow-tube reactor coupled with a quadrupole mass spectrometer. The steady-state uptake coefficient, γ(ss), and the distribution of the gas-phase products were determined as functions of the Al2O3 mass; soot mass; NO2 concentration, varied in the range of (0.2-10) × 10(12) molecules cm(-3); photon flux; and relative humidity, ranging from 0.0032% to 32%. On Al2O3/soot surfaces, the reaction rate was substantially increased, and the formation of HONO was favored compared with that on individual pure soot and pure Al2O3 surfaces. Uptake of NO2 was enhanced in the presence of H2O under both dark and UV irradiation <span class="hlt">conditions</span>, and the following empirical expressions were obtained: γ(ss,BET,dark) = (7.3 ± 0.9) × 10(-7) + (3.2 ± 0.5) × 10(-8) × RH and γ(ss,BET,UV) = (1.4 ± 0.2) × 10(-6) + (4.0 ± 0.9) × 10(-8) × RH. Specific experiments, with solid sample preheating and doping with polycyclic aromatic hydrocarbons (PAHs), showed that UV-absorbing organic compounds significantly affect the chemical reactivity of the mixed mineral/soot surfaces. A mechanistic scheme is proposed, in which Al2O3 can either collect electrons, initiating a sequence of redox reactions, or prevent the charge-recombination process, extending the lifetime of the excited state and enhancing the reactivity of the organics. Finally, the <span class="hlt">atmospheric</span> implications of the observed results are briefly discussed. PMID:24188183</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1346296','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1346296"><span id="translatedtitle"><span class="hlt">Adverse</span> reactions to sulfites</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, William H.; Purchase, Emerson C.R.</p> <p>1985-01-01</p> <p>Sulfites are widely used as preservatives in the food and pharmaceutical industries. In the United States more than 250 cases of sulfite-related <span class="hlt">adverse</span> reactions, including anaphylactic shock, asthmatic attacks, urticaria and angioedema, nausea, abdominal pain and diarrhea, seizures and death, have been reported, including 6 deaths allegedly associated with restaurant food containing sulfites. In Canada 10 sulfite-related <span class="hlt">adverse</span> reactions have been documented, and 1 death suspected to be sulfite-related has occurred. The exact mechanism of sulfite-induced reactions is unknown. Practising physicians should be aware of the clinical manifestations of sulfite-related <span class="hlt">adverse</span> reactions as well as which foods and pharmaceuticals contain sulfites. Cases should be reported to health officials and proper advice given to the victims to prevent further exposure to sulfites. The food industry, including beer and wine manufacturers, and the pharmaceutical industry should consider using alternative preservatives. In the interim, they should list any sulfites in their products. PMID:4052897</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRD..11719207M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRD..11719207M"><span id="translatedtitle">Modification of the IR sky temperature under different <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> in an arid region in central Saudi Arabia: Experimental and theoretical justification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maghrabi, A. H.</p> <p>2012-10-01</p> <p>Sky temperatures that were estimated from a single-channel IR detector over Riyadh, Saudi Arabia, were analyzed from June 2008 to May 2011. The data were divided into three main categories: clear sky, cloudy sky, and dusty <span class="hlt">conditions</span>. The observation and the research results were as follows. During periods of clear-sky <span class="hlt">conditions</span>, it was found that the sky temperatures depend mainly on the <span class="hlt">atmospheric</span> water content, the screen level temperature, and the suspended aerosol particles in the <span class="hlt">atmosphere</span>. Under cloudy <span class="hlt">conditions</span>, the sky temperature ranges between -37°C and 5°C. The mean sky temperatures in this case are higher than those of the clear-sky <span class="hlt">conditions</span> by approximately 11°C to 18°C. The radiative properties of cloudy skies depend on the cloud characteristics and the intervening <span class="hlt">atmosphere</span> between the ground and the cloud base. The sky temperature during dusty <span class="hlt">conditions</span> ranged between -20°C and 8.5°C. The study showed that dusty <span class="hlt">conditions</span> increase the <span class="hlt">atmospheric</span> temperatures by approximately 17°C to 31°C. The sky temperatures during dusty periods are affected by several factors, such as the air mass properties, which bring the dust, and the dust particle characteristics, such as size, shape, and chemical composition, which are initially determined by the sources from which the dust originated. Theoretical simulations using MODTRAN software were used to investigate the <span class="hlt">atmospheric</span> thermal radiation spectral distributions in the three categories. The results show that the major changes occurred within the <span class="hlt">atmospheric</span> window (8-14μm).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27283707','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27283707"><span id="translatedtitle">Impact of packaging <span class="hlt">atmosphere</span>, storage and processing <span class="hlt">conditions</span> on the generation of phytoprostanes as quality processing compounds in almond kernels.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carrasco-Del Amor, Ana María; Aguayo, Encarna; Collado-González, Jacinta; Guy, Alexandre; Galano, Jean-Marie; Durand, Thierry; Gil-Izquierdo, Ángel</p> <p>2016-11-15</p> <p>The thermal processing of almond kernels implies the use of techniques that produce chemical changes such as oxidation. Phytoprostanes (PhytoPs) are considered biomarkers of the oxidative stress in plants. We studied the PhytoP profile in kernels of almond cultivars under different <span class="hlt">conditions</span>, in relation to packaging, temperature and time of storage and processing. The most abundant PhytoP was the F1t series. The PhytoP levels increased significantly with the time of storage (3 and 6months) and the total PhytoP concentration was higher under air than in a vacuum packaging <span class="hlt">atmosphere</span>. Storage at 24°C raised the concentrations of individual PhytoPs and the total sum of PhytoPs. The frying and roasting processes led to a strong reduction of the original concentration of most PhytoPs and promoted the synthesis of specific PhytoPs that were not detected in raw kernels and thus could be biomarkers of the degree of oxidative degradation of almonds. PMID:27283707</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016WRR....52.2737F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016WRR....52.2737F"><span id="translatedtitle">Mapping land water and energy balance relations through <span class="hlt">conditional</span> sampling of remote sensing estimates of <span class="hlt">atmospheric</span> forcing and surface states</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido</p> <p>2016-04-01</p> <p>In this study, we develop and apply a mapping estimation capability for key unknown parameters that link the surface water and energy balance equations. The method is applied to the Gourma region in West Africa. The accuracy of the estimation method at point scale was previously examined using flux tower data. In this study, the capability is scaled to be applicable with remotely sensed data products and hence allow mapping. Parameters of the system are estimated through a process that links <span class="hlt">atmospheric</span> forcing (precipitation and incident radiation), surface states, and unknown parameters. Based on <span class="hlt">conditional</span> averaging of land surface temperature and moisture states, respectively, a single objective function is posed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to parameters to identify evapotranspiration and drainage models and estimate water and energy balance flux components. The uncertainty of the estimated parameters (and associated statistical confidence limits) is obtained through the inverse of Hessian of the objective function, which is an approximation of the covariance matrix. This calibration-free method is applied to the mesoscale region of Gourma in West Africa using multiplatform remote sensing data. The retrievals are verified against tower-flux field site data and physiographic characteristics of the region. The focus is to find the functional form of the evaporative fraction dependence on soil moisture, a key closure function for surface and subsurface heat and moisture dynamics, using remote sensing data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012sf2a.conf..591M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012sf2a.conf..591M&link_type=ABSTRACT"><span id="translatedtitle">Measurements of fluorescence yield of electrons in air under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>: A key parameter for energy of cosmic rays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monnier Ragaigne, D.; Gorodetzky, P.; Blacksley, C.; Wicek, F.; Monard, H.; Dagoret-Campagne, S.</p> <p>2012-12-01</p> <p>The measurement of the fluorescence yield and its dependence on <span class="hlt">atmospheric</span> properties such as pressure, temperature or pollutants, are essential to obtain a reliable measurement of the primary energy of cosmic rays. A new type of absolute measurement of the nitrogen fluorescence yield in the air will be performed at LAL using 3 items which will yield an unprecedented precision in all <span class="hlt">conditions</span> of pressure, temperature, and pollutants. A 5 MeV electron beam will be provided by the new electron accelerator PHIL at LAL(Laboratoire de l'Accélérateur Linéaire, Univ Paris-Sud, CNRS/IN2P3, Orsay). This source will induce florescence yield inside an integrating sphere. The sphere will be surrounded by a spherical envelope to create a temperature controlled chamber (a Dewar). With this setup it will be possible to vary the temperature from -60 C to +40 C and the pressure from 1 to 0.01 atm. An output device on this sphere will be equipped with a set of optical fibers driving the fluorescence light to a Jobin-Yvon spectrometer equipped with an LN_{2} cooled CCD. The fluorescence spectrum in the 300-430 nm range will be accurately measured in steps of 0.1 nm resolution. A PMT equipped with a BG3 filter (the same as on JEM-EUSO) will be set on the sphere to measure the integrated yield. The expected precision of the yield should be better than 5%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013RScI...84b4702O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RScI...84b4702O"><span id="translatedtitle">Time-lag properties of corona streamer discharges between impulse sphere and dc needle electrodes under <span class="hlt">atmospheric</span> air <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okano, Daisuke</p> <p>2013-02-01</p> <p>In this study of corona streamer discharges from an impulse generator using a dc power supply, the relationship of the discharge time-lag with the dc bias voltage between the sphere-to-needle electrodes under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> is investigated. Devices utilizing corona discharges have been used to purify air or water, destroy bacteria, and to remove undesirable substances, and in order to achieve fast response times and high power efficiencies in such devices, it is important to minimize the time-lag of the corona discharge. Our experimental results show that (a) the discharge path of a negatively biased needle electrode will be straighter than that of a positively biased needle and (b) the discharge threshold voltage in both the positive and the negative needle electrodes is nearly equal to 33 kV. By expressing the discharge voltage as a power function of time-lag, the extent of corona generation can be quantitatively specified using the exponent of this power function. The observed behavior of a corona streamer discharge between the negative spherical and the positive needle electrodes indicates that the largest power exponent is associated with the shortest time-lag, owing to the reduction in the statistical time-lag in the absence of a formative time-lag.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23464233','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23464233"><span id="translatedtitle">Time-lag properties of corona streamer discharges between impulse sphere and dc needle electrodes under <span class="hlt">atmospheric</span> air <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Okano, Daisuke</p> <p>2013-02-01</p> <p>In this study of corona streamer discharges from an impulse generator using a dc power supply, the relationship of the discharge time-lag with the dc bias voltage between the sphere-to-needle electrodes under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> is investigated. Devices utilizing corona discharges have been used to purify air or water, destroy bacteria, and to remove undesirable substances, and in order to achieve fast response times and high power efficiencies in such devices, it is important to minimize the time-lag of the corona discharge. Our experimental results show that (a) the discharge path of a negatively biased needle electrode will be straighter than that of a positively biased needle and (b) the discharge threshold voltage in both the positive and the negative needle electrodes is nearly equal to 33 kV. By expressing the discharge voltage as a power function of time-lag, the extent of corona generation can be quantitatively specified using the exponent of this power function. The observed behavior of a corona streamer discharge between the negative spherical and the positive needle electrodes indicates that the largest power exponent is associated with the shortest time-lag, owing to the reduction in the statistical time-lag in the absence of a formative time-lag. PMID:23464233</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.J4004B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.J4004B"><span id="translatedtitle">A Narrow-Linewidth Atomic Line Filter for Free Space Quantum Key Distribution under Daytime <span class="hlt">Atmospheric</span> <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brown, Justin; Woolf, David; Hensley, Joel</p> <p>2016-05-01</p> <p>Quantum key distribution can provide secure optical data links using the established BB84 protocol, though solar backgrounds severely limit the performance through free space. Several approaches to reduce the solar background include time-gating the photon signal, limiting the field of view through geometrical design of the optical system, and spectral rejection using interference filters. Despite optimization of these parameters, the solar background continues to dominate under daytime <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>. We demonstrate an improved spectral filter by replacing the interference filter (Δν ~ 50 GHz) with an atomic line filter (Δν ~ 1 GHz) based on optical rotation of linearly polarized light through a warm Rb vapor. By controlling the magnetic field and the optical depth of the vapor, a spectrally narrow region can be transmitted between crossed polarizers. We find that the transmission is more complex than a single peak and evaluate peak transmission as well as a ratio of peak transmission to average transmission of the local spectrum. We compare filters containing a natural abundance of Rb with those containing isotopically pure 87 Rb and 85 Rb. A filter providing > 95 % transmission and Δν ~ 1.1 GHz is achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15662721','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15662721"><span id="translatedtitle">Control of blue mold (Penicillium expansum) by fludioxonil in apples (cv Empire) under controlled <span class="hlt">atmosphere</span> and cold storage <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Errampalli, Deena; Northover, John; Skog, Lisa; Brubacher, Nichole R; Collucci, Cheryl A</p> <p>2005-06-01</p> <p>A reduced risk fungicide, fludioxonil, was tested for its efficacy against blue mold caused by thiabendazole-resistant and -sensitive Penicillium expansum (Link) Thom in apples under three storage <span class="hlt">conditions</span>. In a co-treatment, fludioxonil and inoculum were applied together to test the protective activity of the fungicide on wounds that had been aged for 1 or 2 days. The fungicide was also tested for its curative activity in post-inoculation treatment on apples that had been inoculated for 1 or 2 days. Fludioxonil was very effective as co-treatment and as post-inoculation treatment. At a concentration of 300 mg litre(-1), fludioxonil gave complete control of post-harvest blue mold caused by the thiabendazole-resistant and -sensitive P expansum for 105 days in controlled <span class="hlt">atmosphere</span> (CA) storage at 2 (+/-1) degrees C, for 42 days in common cold storage at 4 (+/-1) degrees C and also in a shelf-life study for 6 days at 20 (+/-1) degrees C. Comparison on the effect of fludioxonil in CA storage and common cold storage showed that higher concentrations of fungicide were needed in cold storage than in CA storage. Fludioxonil at a concentration of 450 mg litre(-1), gave 98 and 92% control of blue mold of apples in the simulated shelf-life studies after CA and common cold storages, respectively. Fludioxonil has a potential to be incorporated in the fungicide resistance management strategies for control of blue mold in apples stored for 105 days. PMID:15662721</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22059655','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22059655"><span id="translatedtitle">Quality of fresh retail pork cuts stored in modified <span class="hlt">atmosphere</span> under temperature <span class="hlt">conditions</span> simulating export to distant markets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McMullen, L M; Stiles, M E</p> <p>1994-01-01</p> <p>The effect of storage temperature on microbial and sensory quality of retail cuts of pork was determined on samples stored under temperature regimens designed to simulate <span class="hlt">conditions</span> that could be encountered in accessing distant markets with retail-ready product. Samples were packaged in modified <span class="hlt">atmosphere</span> with 100% CO(2) and <200 ppm O(2) in plastic film with extremely low gas transmission rates. All samples were stored at -1·5°C for three weeks. Reference samples were held at -1·5°C for the duration of the study; experimental samples were transferred to 4°C (-1·5 4° C ) or 7°C (-1· 517° C ) and analyzed for microbial content and sebsory attributes including appearance, confinement and meat odours. Storage life of reference samples at -1·5°C was seven weeks before rejection for loss of acceptable appearance. With transfer of samples to 4 and 7°C after three weeks at -1·5°C, samples remained acceptable for retail sale for two weeks and one week, restpectively. The microbial flora was dominated by lactic acid bacteria under all three storage <span class="hlt">conditions</span>. Appearance of the cuts was the principal criterion limiting storage life. Discoloration of the meat was not a problem in this study, but purge and odour, including sour and sulphur notes, became a problem with time. The study indicated that export of retail-ready pork cuts to distant markets with a three-week time for delivery to market at -1·5°C can be achieved with one to two weeks of marketing time at retail market at 4 to 7°C. PMID:22059655</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3967751','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3967751"><span id="translatedtitle">Shelf life of air and modified <span class="hlt">atmosphere</span>-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cyprian, Odoli; Lauzon, Hélène L; Jóhannsson, Ragnar; Sveinsdóttir, Kolbrún; Arason, Sigurjón; Martinsdóttir, Emilía</p> <p>2013-01-01</p> <p>Optimal packaging and storage <span class="hlt">conditions</span> for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and −1°C. Sensory analysis of cooked samples revealed a shelf life of 13–15 days for air-packaged fillets during storage at 1°C and 20 days at −1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g−1. In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (<log 8 CFU g−1) after 23 days of storage at both 1°C and −1°C. However, modified <span class="hlt">atmosphere</span> (MA) packaging negatively affected color characteristics of the fillets soon after packaging (day 6). Color is an important indicator of tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at −1°C storage temperature was the optimal <span class="hlt">condition</span> for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study. PMID:24804022</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Icar..245..153S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Icar..245..153S"><span id="translatedtitle">Laboratory measurements of the 3.7-20 cm wavelength opacity of sulfur dioxide and carbon dioxide under simulated <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steffes, Paul G.; Shahan, Patrick; Christopher Barisich, G.; Bellotti, Amadeo</p> <p>2015-01-01</p> <p>In the past two decades, multiple observations of Venus have been made at X-Band (3.6 cm) using the Jansky Very Large Array (VLA), and maps have been created of the 3.6 cm emission from Venus (see, e.g., Devaraj, K. [2011]. The Centimeter- and Millimeter-Wavelength Ammonia Absorption Spectra under Jovian <span class="hlt">Conditions</span>. PhD Thesis, Georgia Institute of Technology, Atlanta, GA). Since the emission morphology is related both to surface features and to deep <span class="hlt">atmospheric</span> absorption from CO2 and SO2 (see, e.g., Butler, B.J., Steffes, P.G., Suleiman, S.H., Kolodner, M.A., Jenkins, J.M. [2001]. Icarus 154, 226-238), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide <span class="hlt">atmosphere</span> under <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho, W., Kaufman, I.A., Thaddeus, P. [1966]. J. Geophys. Res. 71, 5091-5108), no measurements of the centimeter-wavelength properties of any Venus <span class="hlt">atmospheric</span> constituent have been conducted under <span class="hlt">conditions</span> characteristic of the deep <span class="hlt">atmosphere</span> (pressures from 10 to 92 bars and temperatures from 400 to 700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7 to 20 cm have been conducted under simulated <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus, using a new high-pressure system. Results from this measurement campaign conducted at temperatures from 430 K to 560 K and at pressures up to 92 bars are presented. Results indicate that the model for the centimeter-wavelength opacity from pure CO2 (Ho, W., Kaufman, I.A., Thaddeus, P. [1966]. J. Geophys. Res. 71, 5091-5108), is valid over the entire centimeter-wavelength range under simulated <span class="hlt">conditions</span> for the deep <span class="hlt">atmosphere</span> of Venus. Additionally, the laboratory results indicate that both of the models for the centimeter-wavelength opacity of SO2 in a CO2 <span class="hlt">atmosphere</span> from Suleiman et al. (Suleiman, S</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.3257K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.3257K"><span id="translatedtitle">Formation of Complex Amino Acid Precursors in Simulated Primitive <span class="hlt">Atmosphere</span> and Their Alteration under Simulated Submarine Hydrothermal <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kobayashi, Kensei; Kurihara, Hironari; Hirako, Tomoaki; Obayashi, Yumiko; Kaneko, Takeo; Takano, Yoshinori; Yoshimura, Yoshitaka</p> <p></p> <p>Since late 1970's a great number of submarine hydrothermal systems (SHSs) has been dis-covered, and they are considered possible sites of chemical evolution and generation of life on the Earth since their discovery in late 1970s. A number of experiments simulating the <span class="hlt">con-ditions</span> of SHSs were conducted, and abiotic production and polymerization of amino acids were reported. Free amino acids were frequently used as starting materials to examine possible organic reactions in the simulation experiments. In our early studies, not free amino acids but complex amino acids precursors with large molecular weights were formed abiotically from simulated primitive Earth <span class="hlt">atmosphere</span> (a mixture of CO, N2 and H2 O) (Takano et al., 2004). Such complex organics (hereafter referred as to CNWs) should have been delivered to SHSs in Primitive Ocean, where they were subjected to further alteration. We examined possible alteration of the complex organics in high-temperature high-pressure environments by the su-percritical water flow reactor (SCWFR) (Islam et al.. 2003) and an autoclave. CNWs were quite hydrophilic compounds whose molecular weights were ca. 3000. After heating 573 K for 2 min in the SCWFR, aggregates of organics were formed, which were separated from aque-ous solution with a Nucleopore filter (pore size: 200 nm). We propose the following scenario of chemical evolution: (1) Complex organics including amino acid precursors were formed in primitive <span class="hlt">atmosphere</span> and/or extraterrestrial environments, (ii) they were delivered to primor-dial SHSs, (iii) hydrothermal alteration occurred in SHSs to give organic aggregates, (iv) quite primitive molecular systems with subtle biological functions were generated in the competition among such aggregates. References: Islam, Md. N., Kaneko, T., and Kobayashi, K (2003). Reactions of Amino Acids with a Newly ConstructedSupercritical Water Flow Reactor Simulating Submarine Hydrothermal Systems. Bull. Chem. Soc. Jpn., 76, 1171. Takano, Y</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.8020A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.8020A"><span id="translatedtitle">Reconstruction of a meteotsunami in Lake Erie on 27 May 2012: Roles of <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> on hydrodynamic response in enclosed basins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, Eric J.; Bechle, Adam J.; Wu, Chin H.; Schwab, David J.; Mann, Greg E.; Lombardy, Kirk A.</p> <p>2015-12-01</p> <p>On 27 May 2012, <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> gave rise to two convective systems that generated a series of waves in the meteotsunami band on Lake Erie. The resulting waves swept three swimmers a 0.5 mi offshore, inundated a marina, and may have led to a capsized boat along the southern shoreline. Analysis of radial velocities from a nearby radar tower in combination with coastal meteorological observation indicates that the convective systems produced a series of outflow bands that were the likely <span class="hlt">atmospheric</span> cause of the meteotsunami. In order to explain the processes that led to meteotsunami generation, we model the hydrodynamic response to three meteorological forcing scenarios: (i) the reconstructed <span class="hlt">atmospheric</span> disturbance from radar analysis, (ii) simulated <span class="hlt">conditions</span> from a high-resolution weather model, and (iii) interpolated meteorological <span class="hlt">conditions</span> from the NOAA Great Lakes Coastal Forecasting System. The results reveal that the convective systems generated a series of waves incident to the southern shore of the lake that reflected toward the northern shoreline and reflected again to the southern shore, resulting in spatial wave focusing and edge wave formation that combined to impact recreational users near Cleveland, OH. This study illustrates the effects of meteotsunami development in an enclosed basin, including wave reflection, focusing, and edge wave formation as well as temporal lags between the causative <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> and arrival of dangerous wave <span class="hlt">conditions</span>. As a result, the ability to detect these extreme storms and predict the hydrodynamic response is crucial to reducing risk and building resilient coastal communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12715578','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12715578"><span id="translatedtitle">Learning from <span class="hlt">adverse</span> incidents involving medical devices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amoore, John; Ingram, Paula</p> <p></p> <p>While an <span class="hlt">adverse</span> event involving a medical device is often ascribed to either user error or device failure, the causes are typically multifactorial. A number of incidents involving medical devices are explored using this approach to investigate the various causes of the incident and the protective barriers that minimised or prevented <span class="hlt">adverse</span> consequences. User factors, including mistakes, omissions and lack of training, conspired with background factors--device controls and device design, storage <span class="hlt">conditions</span>, hidden device damage and physical layout of equipment when in use--to cause the <span class="hlt">adverse</span> events. Protective barriers that prevented or minimised the consequences included staff vigilance, operating procedures and alarms. PMID:12715578</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Hormone&pg=6&id=EJ1000111','ERIC'); return false;" href="http://eric.ed.gov/?q=Hormone&pg=6&id=EJ1000111"><span id="translatedtitle">Scientists Trace <span class="hlt">Adversity</span>'s Toll</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sparks, Sarah D.</p> <p>2012-01-01</p> <p>The stress of a spelling bee or a challenging science project can enhance a student's focus and promote learning. But the stress of a dysfunctional or unstable home life can poison a child's cognitive ability for a lifetime, according to new research. Those studies show that stress forms the link between childhood <span class="hlt">adversity</span> and poor academic…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMGC21A..02T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMGC21A..02T"><span id="translatedtitle">U.S. Jet Contrail Frequency Changes: Influences of Jet Aircraft Flight Activity, <span class="hlt">Atmospheric</span> <span class="hlt">Conditions</span>, and Resultant Policy Implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Travis, D. J.; Carleton, A. M.</p> <p>2005-12-01</p> <p>In regions where jet air traffic is most abundant, condensation trails (contrails) may substantially increase the high cloud coverage, potentially affecting climate. This is particularly so when <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> support prolonged persistence of contrails, which results in their occurrence in clusters, or ``outbreaks'', thus, allowing them to represent a substantial percentage of the overall high cloud amount. In the U.S., jet kilometers flown have increased dramatically during the past three decades leading to speculation that contrail coverage also has increased. However, contrail occurrence depends heavily upon the meteorological <span class="hlt">conditions</span> near aircraft cruising altitudes (i.e., near the tropopause, 10-12 km altitude). Moreover, the tropopause figures prominently in projecting future climate changes. This study reports a contrail mid-season climatology for the coterminous U.S. (2000-02), and compares the frequencies with those previously reported for an earlier (1977-79) period, to determine the contrail frequency increase (CFI). For the 2000-02 period, we also report the seasonal frequency and areal coverage of contrail outbreaks as a means to assess the typical size of contrail susceptible regions on a seasonal and daily basis. Contrail frequency for both periods, and occurrence of outbreaks for 2000-02, is derived from analysis of high-resolution satellite imagery. Data on jet aircraft flight activity (JFA) over the U.S. were obtained to assess their relationship to CFI, as were NCEP-NCAR reanalysis data to determine changes in tropopause-level <span class="hlt">conditions</span>. For 2000-02, contrails comprise distinct high (low) frequencies in the East (West) U.S. Seasonally, there is a contrail association with the latitudinal migration of the jet stream. The inter-monthly variations in contrail frequency are statistically significant but show no association with JFA, indicating a greater role for meteorological <span class="hlt">conditions</span>. Contrail outbreaks occur most frequently during</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890025466&hterms=multichannel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmultichannel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890025466&hterms=multichannel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmultichannel"><span id="translatedtitle">A pilot study to determine relationships between North Pacific precipitation from Nimbus-7 Scanning Multichannel Microwave Radiometer data and associated <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, Mark R.; Roads, John O.</p> <p>1988-01-01</p> <p>Relationships between the large scale field and the location of cyclone tracks are found by deriving monthly precipitation positions in the North Pacific. The precipitation locations are determined from Nimbus-7 SMMR data for the winter seasons 1978-1979 and 1979-1980. These locations are compared to the large scale <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27049197','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27049197"><span id="translatedtitle">Collateral <span class="hlt">Adverse</span> Outcomes After Lumbar Spine Surgery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daniels, Alan H; Gundle, Kenneth; Hart, Robert A</p> <p>2016-01-01</p> <p>Collateral <span class="hlt">adverse</span> outcomes are the expected or unavoidable results of a procedure that is performed in a standard manner and typically experienced by the patient. Collateral <span class="hlt">adverse</span> outcomes do not result from errors, nor are they rare. Collateral <span class="hlt">adverse</span> outcomes occur as the direct result of a surgical procedure and must be accepted as a trade-off to attain the intended benefits of the surgical procedure. As such, collateral <span class="hlt">adverse</span> outcomes do not fit into the traditional definition of a complication or <span class="hlt">adverse</span> event. Examples of collateral <span class="hlt">adverse</span> outcomes after lumbar spine arthrodesis include lumbar stiffness, postoperative psychological stress, postoperative pain, peri-incisional numbness, paraspinal muscle denervation, and adjacent-level degeneration. Ideally, a comparison of interventions for the treatment of a clinical <span class="hlt">condition</span> should include information on both the negative consequences (expected and unexpected) and potential benefits of the treatment options. The objective evaluation and reporting of collateral <span class="hlt">adverse</span> outcomes will provide surgeons with a more complete picture of invasive interventions and, thus, the improved ability to assess alternative treatment options. PMID:27049197</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1083379','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1083379"><span id="translatedtitle">Adding Complex Terrain and Stable <span class="hlt">Atmospheric</span> <span class="hlt">Condition</span> Capability to the Simulator for On/Offshore Wind Farm Applications (SOWFA) (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Churchfield, M. J.</p> <p>2013-06-01</p> <p>This presentation describes changes made to NREL's OpenFOAM-based wind plant aerodynamics solver so that it can compute the stably stratified <span class="hlt">atmospheric</span> boundary layer and flow over terrain. Background about the flow solver, the Simulator for Off/Onshore Wind Farm Applications (SOWFA) is given, followed by details of the stable stratification/complex terrain modifications to SOWFA, along with some preliminary results calculations of a stable <span class="hlt">atmospheric</span> boundary layer and flow over a simple set of hills.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850013927&hterms=thermal+quadrupoles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dthermal%2Bquadrupoles','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850013927&hterms=thermal+quadrupoles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dthermal%2Bquadrupoles"><span id="translatedtitle">A computer controlled mass spectrometer system for investigating the decomposition of non-metallic materials under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, J. M.</p> <p>1985-01-01</p> <p>A PDP 11/23 quadrupole mass spectrometer system was coupled to a nondiscriminating gas inlet system permitting gases at <span class="hlt">atmospheric</span> pressure to be admitted into a high vacuum chamber containing the ion source of the mass spectrometer without separation of the gaseous components. The resolution of related software problems has resulted in a convenient computer-mass spectrometer system capable of generating masses, relative intensities and related data on the gaseous products resulting from the <span class="hlt">atmospheric</span> thermal decomposition of nonmetallic materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860045005&hterms=Vapor+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2528Vapor%2Bpressure%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860045005&hterms=Vapor+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2528Vapor%2Bpressure%2529"><span id="translatedtitle">Laboratory measurements of the microwave opacity and vapor pressure of sulfuric acid vapor under simulated <span class="hlt">conditions</span> for the middle <span class="hlt">atmosphere</span> of Venus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steffes, P. G.</p> <p>1985-01-01</p> <p>Microwave absorption measurements at wavelengths of 13.4 and 3.6 cm were made in gaseous H2SO4 in a CO2 <span class="hlt">atmosphere</span> under simulated <span class="hlt">conditions</span> for the Venus middle <span class="hlt">atmosphere</span>. The results suggest that abundances of gaseous H2SO4 on the order of 15-30 ppm could account for the absorption observed by radio occultation measurements at these wavelengths. They also imply that such abundances would correspond to saturation vapor pressure existing at or above the 46-48-km range, which correlates with the observed cloud base.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160006531','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160006531"><span id="translatedtitle">Measurements of <span class="hlt">Atmospheric</span> CO2 Column in Cloudy Weather <span class="hlt">Conditions</span> using An IM-CW Lidar at 1.57 Micron</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lin, Bing; Obland, Michael; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Campbell, Joel; Dobler, Jeremy; Meadows, Bryon; Fan, Tai-Fang; Kooi, Susan; Ismail, Syed</p> <p>2015-01-01</p> <p>This study evaluates the capability of <span class="hlt">atmospheric</span> CO2 column measurements under cloudy <span class="hlt">conditions</span> using an airborne intensity-modulated continuous-wave integrated-path-differential-absorption lidar operating in the 1.57-m CO2 absorption band. The <span class="hlt">atmospheric</span> CO2 column amounts from the aircraft to the tops of optically thick cumulus clouds and to the surface in the presence of optically thin clouds are retrieved from lidar data obtained during the summer 2011 and spring 2013 flight campaigns, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACPD...1411855M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACPD...1411855M"><span id="translatedtitle"><span class="hlt">Atmospheric</span> winter <span class="hlt">conditions</span> 2007/08 over the Arctic Ocean based on NP-35 data and regional model simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mielke, M.; Zinoviev, N. S.; Dethloff, K.; Rinke, A.; Kustov, V. J.; Makshtas, A. P.; Sokolov, V. T.; Neuber, R.; Maturilli, M.; Klaus, D.; Handorf, D.; Graeser, J.</p> <p>2014-05-01</p> <p><span class="hlt">Atmospheric</span> measurements on the drifting Arctic sea ice station "North Pole-35" crossing the Eastern part of the Arctic Ocean during winter 2007/2008 have been compared with regional <span class="hlt">atmospheric</span> HIRHAM model simulations. The observed near-surface temperature, mean sea level pressure and the vertical temperature, wind and humidity profiles are satisfactorily reproduced by the model. The strongest temperature differences between observations and the simulations occur near the surface due to an overestimated vertical mixing of heat in the stable Arctic boundary layer (ABL). The observations show very strong temperature inversions near the surface, whereas the simulated inversions occur frequently between the surface and 415 m at too high levels. The simulations are not able to reproduce the observed inversion strength. The regional model underestimates the wind speeds and the sharp vertical wind gradients. The strength of internal <span class="hlt">atmospheric</span> dynamics on the temporal development of <span class="hlt">atmospheric</span> surface variables and vertical profiles of temperature, wind and relative humidity has been examined. Although the HIRHAM model systematically overestimates relative humidity and produces too high long-wave downward radiation during winter, two different <span class="hlt">atmospheric</span> circulation states, which are connected to higher or lower pressure systems over the Eastern part of the Arctic Ocean, are simulated in agreement with the NP-35 observations. Sensitivity studies with reduced vertical mixing of heat in the stable ABL have been carried out. A slower increase in the stability functions with decreasing Richardson number under stable stratification has an impact on the horizontal and vertical <span class="hlt">atmospheric</span> structure. Changes in synoptical cyclones on time scales from 1-3 days over the North Atlantic cyclone path are generated, which influences the <span class="hlt">atmospheric</span> baroclinic and planetary waves on time scales up to 20 days over the Arctic Ocean basin. The use of increased vertical stability in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4829637','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4829637"><span id="translatedtitle">Biomolecular characterization, identification, enzyme activities of molds and physiological changes in sweet potatoes (Ipomea batatas) stored under controlled <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Oladoye, C. O.; Connerton, I. F.; Kayode, R. M. O.; Omojasola, P. F.; Kayode, I. B.</p> <p>2016-01-01</p> <p>Microbial attacks during storage are one of the primary causes of product deterioration, and can limit the process of prolonging the shelf-life of harvested food. In this study, sweet potatoes were stored at temperatures of 13, 21, and 29 °C for 4 weeks. Samples were collected during storage and plated on potato dextrose agar, from which axenic mold cultures were obtained and identified using 26S rRNA gene sequences. Physiological changes of potato tubers were assessed with respect to pathogenicity, enzyme activity, and <span class="hlt">atmospheric</span> storage <span class="hlt">conditions</span>. Six fungal species were identified, namely Penicillium chrysogenum (P. rubens), P. brevicompactum, Mucor circinelloides, Cladosporium cladosporiodes, P. expansum, and P. crustosum. The following fungal isolates, namely P. expansum, P. brevicompactum, and Rhizopus oryzae, were recovered from the re-infected samples and selected according to their levels of enzyme activity. This study revealed high levels of activity for cellulase and pectinase, which were most notable during the initial three days of testing, and were followed by a steady decrease (P<0.05). Polygalacturonase activity was prominent with values ranging from 12.64 to 56.79 U/mg (P. expansum) and 18.36 to 79.01 U/mg (P. brevicompactum). Spoilage was obvious in the control group, which had a 100% decay at the end of the experimental period compared with samples treated with iprodione and sodium hypochlorite, in which the decay rates were 5% and 55%, respectively. The data for the iprodione- and sodium hypochlorite-treated samples at the end of the 3-month storage period showed that they were significantly different (P=0.041), with the sodium hypochlorite-treated samples producing twice the rate of infection compared to the iprodione-treated samples. The comparative rate of the progression of decay in the treated samples can be expressed as iprodione<sodium hypochlorite<control. This study demonstrates that sweet potato tissue damage is due to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15826569','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15826569"><span id="translatedtitle">[<span class="hlt">Adverse</span> reaction of pseudoephedrine].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>López Lois, G; Gómez Carrasco, J A; García de Frías, E</p> <p>2005-04-01</p> <p>We present a case of a 7 years old girl who developed an episode of myoclonic movements and tremors after being medicated with a not well quantified amount of a pseudoephedrine/antihistamine combination. We want to highlight the potential toxicity of pseudoephedrine, usually administered as part of cold-syrup preparations which are used for symptomatic treatment of upper respiratory tract cough and congestion associated with the common cold and allergic rhinitis. Although these products are generally considered to be safe either by physicians and parents, we can't underestimate the potential <span class="hlt">adverse</span> events and toxic effects that can occur when administering these medications. PMID:15826569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1100..451C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1100..451C"><span id="translatedtitle">Stochastic Model for Shortwave Radiation Transfer in a Multiple-Layered <span class="hlt">Atmosphere</span>: Surface Global Radiation in Cloudless <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ceballos, Juan Carlos; de Souza, Juarez Dantas; da Silva, Bernardo Barbosa</p> <p>2009-03-01</p> <p>A two-flux method is presented, which describes propagation of solar radiation in the <span class="hlt">atmosphere</span> as a random walk of diffuse photons among several <span class="hlt">atmospheric</span> layers. Results are obtained in terms of absorption probabilities in each layer, at ground and within sky, allowing to easily introduce and to analyze influence of profiles of the main <span class="hlt">atmospheric</span> absorbers (ozone, aerosols and water vapor). Global radiation is obtained by integration of monochromatic irradiances. Application of this model to cloudless situations in the extreme cases of rural environment and high aerosol load by burning biomass shows good results when compared with SBDART code (they have a systematic deviation of +10 Wṡm-2), and both differ from ground measurements of global radiation within 30 to 50 Wṡm-2. This difference could be lowered having a better definition of aerosol load during daytime. It is observed that the stochastic model performance is five times faster than SBDART.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10468381','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10468381"><span id="translatedtitle">Screening for <span class="hlt">adverse</span> events.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karson, A S; Bates, D W</p> <p>1999-02-01</p> <p><span class="hlt">Adverse</span> events (AEs) in medical patients are common, costly, and often preventable. Development of quality improvement programs to decrease the number and impact of AEs demands effective methods for screening for AEs on a routine basis. Here we describe the impact, types, and potential causes of AEs and review various techniques for identifying AEs. We evaluate the use of generic screening criteria in detail and describe a recent study of the sensitivity and specificity of individual generic screening criteria and combinations of these criteria. In general, the most sensitive screens were the least specific and no small sub-set of screens identified a large percentage of <span class="hlt">adverse</span> events. Combinations of screens that were limited to administrative data were the least expensive, but none were particularly sensitive, although in practice they might be effective since routine screening is currently rarely done. As computer systems increase in sophistication sensitivity will improve. We also discuss recent studies that suggest that programs that screen for and identify AEs can be useful in reducing AE rates. While tools for identifying AEs have strengths and weaknesses, they can play an important role in organizations' quality improvement portfolios. PMID:10468381</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27550756','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27550756"><span id="translatedtitle">Terrestrial <span class="hlt">atmospheric</span> responses on Svalbard to the 20 March 2015 Arctic total solar eclipse under extreme <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pasachoff, J M; Peñaloza-Murillo, M A; Carter, A L; Roman, M T</p> <p>2016-09-28</p> <p>This article reports on the near-surface <span class="hlt">atmospheric</span> response at the High Arctic site of Svalbard, latitude 78° N, as a result of abrupt changes in solar insolation during the 20 March 2015 equinox total solar eclipse and notifies the <span class="hlt">atmospheric</span> science community of the availability of a rare dataset. Svalbard was central in the path of totality, and had completely clear skies. Measurements of shaded air temperature and <span class="hlt">atmospheric</span> pressure show only weak, if any, responses to the reduced insolation. A minimum in the air temperature at 1.5 m above the ground occurred starting 2 min following the end of totality, though this drop was only slightly beyond the observed variability for the midday period. Eclipse-produced variations in surface pressure, if present, were less than 0.3 hPa.This article is part of the themed issue '<span class="hlt">Atmospheric</span> effects of solar eclipses stimulated by the 2015 UK eclipse'. PMID:27550756</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=211444','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=211444"><span id="translatedtitle">Effects of Conventional Tillage and No-Tillage on Crop Gas Exchange Under Elevated <span class="hlt">Atmospheric</span> CO2 <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Increasing <span class="hlt">atmospheric</span> CO2 concentration has led to concerns about potential effects on production agriculture. In the fall of 1997, a study was initiated to compare the response of two crop management systems (conventional and conservation) to elevated CO2. The study used a split-plot design replic...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1815634H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1815634H"><span id="translatedtitle">Disentangling the role of <span class="hlt">atmospheric</span> and oceanic <span class="hlt">conditions</span> in the occurrence of major Baltic inflows: The importance of haline stratification in the Belt Sea.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Höflich, Katharina; Lehmann, Andreas; Myrberg, Kai</p> <p>2016-04-01</p> <p>The Baltic Sea is a semi-enclosed body of water connected to the North Sea only via the shallow and narrow Danish Straits. Of special importance to the salinity dynamics of the Baltic Sea are so-called major Baltic inflows (highly saline barotropic inflows), that also comprise the only process by which oxygen is supplied to below halocline water masses. Large barotropic inflows (or large volume changes) of the Baltic Sea can be identified from the sea level at Landsort, where the number of large barotropic inflows is found to exceed the number of major Baltic inflows. The occurrence of major Baltic inflows is typically attributed to a sequence of large-scale easterly and westerly <span class="hlt">atmospheric</span> circulation patterns, that have recently also been linked to the occurrence of large barotropic inflows in general. In this context the widely accepted view that <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> (and hence the evolution of the sea level in the North Sea - Baltic Sea system) are of exclusive importance to the occurrence of major Baltic inflows becomes questionable. In this study we attempt to disentangle the role of oceanic and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> to the occurrence of highly saline barotropic inflows, with special focus on the role of the hydrographic <span class="hlt">conditions</span> in the Belt Sea. For the period 1979 - 2015 and using a realistic three-dimensional numerical ocean model of the Baltic Sea we find that the salinity of the barotropic inflow significantly depends on the availability of saline water masses in the Belt Sea. However, detailed investigation on the time evolution of the single barotropic inflow reveals differences in the rapidness and magnitude of the inflow events. Both are in fact good predictors for the salinity of the inflow, highlighting that within the set of large barotropic inflows also differing <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> must play some role in the formation of the salinity of the inflowing water mass. In order to further specify the importance of the hydrographic <span class="hlt">conditions</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CTGeo...1...13J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CTGeo...1...13J"><span id="translatedtitle"><span class="hlt">Atmospheric</span> Circulation Influence on the Winter Thermal <span class="hlt">Conditions</span> in Poland in 2021-2050 Based on the RACMO2 Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jędruszkiewicz, Joanna; Piotrowski, Piotr</p> <p>2012-01-01</p> <p>Thermal <span class="hlt">conditions</span> are largely determined by <span class="hlt">atmospheric</span> circulation. Therefore, projection of future temperature changes should be considered in relation to changes in circulation patterns. This paper assess to what extent changes in circulation correspond to spatial variability of the winter temperature increase in Poland in 2021-2050 period based on the RACMO2 model. The daily data of the mean temperature and sea level pressure (SLP) from selected regional climate model and observations were used. SLP data were used to determine the advection types and circulation character. Firstly, changes in frequency of circulation types between 2021-2050 and 1971-2000 periods were examined. Then changes in air temperature for specific circulation type in relation to reference period were studied. Finally, the influence of <span class="hlt">atmospheric</span> circulation on spatial temperature variation was discussed. Considerably high increase in cyclonic situation of more than 18%, especially from the west and south-west direction, and decrease in anticyclonic situation mainly from the west and northwest in winter was noticed. Changes in frequency of circulation types result in temperature growth. For some types it is predicted that warming can reach even 3-4°C. The cyclonic (Ec, SEc, Sc) and anticylonic (SEa, Sa, Ea) types are likely to foster the highest warming in the scenario period. Polska charakteryzuje się znacznym zróżnicowaniem przestrzennym w rozkładzie temperatury powietrza w porze zimowej. W sezonie zimowym przeważa południkowy układ izoterm co świadczy o silnym oddziaływaniu z jednej strony ciepłych, wilgotnych mas powietrza napływających znad Atlantyku, a z drugiej chłodniejszych i bardziej suchych znad kontynentu azjatyckiego. Regionalne modele klimatu opracowane dla obszaru Europy wskazują jednoznacznie na wzrost temperatury w okresie zimy na obszarze całego kontynentu, szczególnie a wschodzie i północnym-wschodzie kontynentu, nawet o 3°C. Projekcje te s</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614954R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614954R"><span id="translatedtitle">A Coupled <span class="hlt">Atmosphere</span>-Ocean modelling system to investigate the exceptional Winter 2012 <span class="hlt">conditions</span> in the Northern Adriatic Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ricchi, Antonio; Marcello Miglietta, M.; Benetazzo, Alvise; Warner, John C.; Zambon, Joseph B.; Bonaldo, Davide; Falcieri, Francesco M.; Bergamasco, Andrea; Sclavo, Mauro; Carniel, Sandro</p> <p>2014-05-01</p> <p>During late January and early February 2012, a persistent cyclonic circulation associated with an exceptional cold anomaly dominated the Mediterranean region. Among the resulting effects, the northern Adriatic sea basin (NA) experienced a very large energy losses, mostly related to the intense and cold Bora winds blowing from north-east. Sea water temperature along the Italian coast dropped down to 6 °C, while part of the Venice lagoon got frozen. These series of exceptionally cold air outbreak episodes, as well as their effects on the NA circulation and dense water formation, are investigated by means of the Coupled Ocean-<span class="hlt">Atmosphere</span>-Wave-Sediment Transport (COAWST) Modeling System, where the oceanographic model ROMS, the <span class="hlt">atmospheric</span> model WRF and the wave model SWAN are coupled via MCT. In this specific application to the NA sea configuration, lasting from January 23 to February 23, 2012, particular emphasis was devoted to the analysis of the <span class="hlt">atmosphere</span>-ocean-waves interactions. First, we employ the "stand alone" WRF <span class="hlt">atmospheric</span> model in 4 different modes ("zero mode", i.e. using the skin temperature from the global <span class="hlt">atmospheric</span> model without updating in the Sea Surface Temperature (SST); "static mode", i.e. retaining the January 23 radiometer SST; "dynamic mode", updating every 6 hours the SST as derived from radiometer data at 0.83 deg resolution; "OML mode", as above, but using a simple Ocean Mixed Layer model available within WRF to predict the temperature evolution). Second, the WRF-ROMS one-way forced case is analyzed, where no feedbacks to the <span class="hlt">atmosphere</span> are provided from the ocean model ROMS, but momentum and heat fluxes are determined by WRF model. Then, the WRF-ROMS two-way coupled case is implemented (where the <span class="hlt">atmosphere</span> model exchanges momentum and heat, and the ocean model exchanges SST with the <span class="hlt">Atmospheric</span> model). Finally, the WRF-ROMS-SWAN two-way coupled case for waves-ocean-<span class="hlt">atmosphere</span> is performed, where common variables are exchanged every 1200</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21396158','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21396158"><span id="translatedtitle">SO{sub 2} effects on CO oxidation in a CO{sub 2} <span class="hlt">atmosphere</span>, characteristic of oxy-fuel <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gimenez-Lopez, J.; Martinez, M.; Millera, A.; Bilbao, R.; Alzueta, M.U.</p> <p>2011-01-15</p> <p>SO{sub 2} is an important pollutant formed during many combustion processes which may affect the oxidation of the fuel. The current work focuses on the evaluation of the effect of the presence of SO{sub 2} on CO oxidation in a CO{sub 2} <span class="hlt">atmosphere</span>, found in oxy-fuel combustion, in comparison to a N{sub 2} dilution characteristic of air combustion. A flow reactor experimental and kinetic modeling study of the gas-phase interaction of SO{sub 2} with the radical pool during CO oxidation under CO{sub 2} and N{sub 2} diluted <span class="hlt">conditions</span> has been carried out for different stoichiometries in the 800-1800 K temperature range. The presence of SO{sub 2} is seen to inhibit the oxidation of CO in both <span class="hlt">atmospheres</span> for all the stoichiometries studied, although the inhibition is significantly higher as the stoichiometry becomes more reducing. The inhibiting effect of SO{sub 2} in the CO{sub 2} <span class="hlt">atmosphere</span> is caused by similar radical recombination mechanisms than those occurring with N{sub 2}. Under fuel-rich <span class="hlt">conditions</span>, the inhibition is governed by the SO{sub 2}/HOSO inter-conversion and is less pronounced as the CO{sub 2} concentration increases. However, as the <span class="hlt">conditions</span> are more fuel-lean, the SO{sub 2} inhibiting effect is comparable in both <span class="hlt">atmospheres</span> due to the higher importance of the SO{sub 2} + O recombination. As the SO{sub 2} concentration increases, its interaction with the radical pool is enhanced and the inhibition of CO oxidation is higher. An updated kinetic mechanism is used for calculations and provides a very good description of the experimental results for all the operating <span class="hlt">conditions</span> analyzed. (author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3857126','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3857126"><span id="translatedtitle">ISMP <span class="hlt">Adverse</span> Drug Reactions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>The purpose of this feature is to heighten awareness of specific <span class="hlt">adverse</span> drug reactions (ADRs), discuss methods of prevention, and promote reporting of ADRs to the US Food and Drug Administration’s (FDA’s) MedWatch program (800-FDA-1088). If you have reported an interesting, preventable ADR to MedWatch, please consider sharing the account with our readers. Write to Dr. Mancano at ISMP, 200 Lakeside Drive, Suite 200, Horsham, PA 19044 (phone: 215-707-4936; e-mail: mmancano@temple.edu). Your report will be published anonymously unless otherwise requested. This feature is provided by the Institute for Safe Medication Practices (ISMP) in cooperation with the FDA’s MedWatch program and Temple University School of Pharmacy. ISMP is an FDA MedWatch partner. PMID:24421544</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25458866','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25458866"><span id="translatedtitle">[Cutaneous <span class="hlt">adverse</span> drug reactions].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lebrun-Vignes, B; Valeyrie-Allanore, L</p> <p>2015-04-01</p> <p>Cutaneous <span class="hlt">adverse</span> drug reactions (CADR) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Exanthematous eruptions, urticaria and vasculitis are the most common forms of CADR. Fixed eruption is uncommon in western countries. Serious reactions (fatal outcome, sequelae) represent 2% of CADR: bullous reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), DRESS (drug reaction with eosinophilia and systemic symptoms or drug-induced hypersensitivity syndrome) and acute generalized exanthematous pustulosis (AGEP). These forms must be quickly diagnosed to guide their management. The main risk factors are immunosuppression, autoimmunity and some HLA alleles in bullous reactions and DRESS. Most systemic drugs may induce cutaneous <span class="hlt">adverse</span> reactions, especially antibiotics, anticonvulsivants, antineoplastic drugs, non-steroidal anti-inflammatory drugs, allopurinol and contrast media. Pathogenesis includes immediate or delayed immunologic mechanism, usually not related to dose, and pharmacologic/toxic mechanism, commonly dose-dependent or time-dependent. In case of immunologic mechanism, allergologic exploration is possible to clarify drug causality, with a variable sensitivity according to the drug and to the CADR type. It includes epicutaneous patch testing, prick test and intradermal test. However, no in vivo or in vitro test can confirm the drug causality. To determine the cause of the eruption, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis is required, completed with a literature search. A reporting to pharmacovigilance network is essential in case of a serious CADR whatever the suspected drug and in any case if the involved drug is a newly marketed one or unusually related to cutaneous reactions. PMID:25458866</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6721336','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6721336"><span id="translatedtitle">Paleoclimatic tracers: An investigation using an <span class="hlt">atmospheric</span> general circulation model under ice age <span class="hlt">conditions</span>. 1. Desert dust</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Joussaume, S. )</p> <p>1993-02-20</p> <p>Many studies with <span class="hlt">atmospheric</span> general circulation models (AGCMs) have demonstrated their usefulness in reconstructing past climates. In a new approach, the author has used an AGCM to investigate the link between tracer cycles and climate. He considers in this paper the <span class="hlt">atmospheric</span> cyle of windblown dust material from desertic areas and in part 2 the water isotope cycles. Studies from ice cores have shown a strong increase of the dust deposits during glacial periods, both over East Antarctica and Greenland. He does not know, however, whether this past increase is global or just a local feature, where the dust came from and what are the mechanisms yielding this increase. He tries to answer these questions by using an AGCM including a model for the desert dust cycle to simulate the present-day and Last Glacial Maximum climates for February and August. The model simulates only a weak increase of the global <span class="hlt">atmospheric</span> dust content. Stronger variations are obtained at a regional scale and are in good agreement with observations from deep-sea sediments. However, the model does not reproduce the great increase of the dust concentrations in snow that has been observed in ice cores. Several model deficiencies can induce this model-data discrepancy as, for example, inaccuracies of the circulation patterns or of the dust model. However, most likely, the model fails to simulate the actual sources of dust. 73 refs., 23 figs., 5 tabs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC51J..02G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC51J..02G"><span id="translatedtitle">Effect of thermal stability/complex terrain on wind turbine model(s): a wind tunnel study to address complex <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guala, M.; Hu, S. J.; Chamorro, L. P.</p> <p>2011-12-01</p> <p>Turbulent boundary layer measurements in both wind tunnel and in the near-neutral <span class="hlt">atmospheric</span> surface layer revealed in the last decade the significant contribution of the large scales of motions to both turbulent kinetic energy and Reynolds stresses, for a wide range of Reynolds number. These scales are known to grow throughout the logarithmic layer and to extend several boundary layer heights in the streamwise direction. Potentially, they are a source of strong unsteadiness in the power output of wind turbines and in the aerodynamic loads of wind turbine blades. However, the large scales in realistic <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> deserves further study, with well controlled boundary <span class="hlt">conditions</span>. In the <span class="hlt">atmospheric</span> wind tunnel of the St. Anthony Falls Laboratory, with a 16 m long test section and independently controlled incoming flow and floor temperatures, turbulent boundary layers in a range of stability <span class="hlt">conditions</span>, from the stratified to the convective case, can be reproduced and monitored. Measurements of fluctuating temperature, streamwise and wall normal velocity components are simultaneously obtained by an ad hoc calibrated and customized triple-wire sensor. A wind turbine model with constant loading DC motor, constant tip speed ratio, and a rotor diameter of 0.128m is used to mimic a large full scale turbine in the <span class="hlt">atmospheric</span> boundary layer. Measurements of the fluctuating voltage generated by the DC motor are compared with measurements of the blade's angular velocity by laser scanning, and eventually related to velocity measurements from the triple-wire sensor. This study preliminary explores the effect of weak stability and complex terrain (through a set of spanwise aligned topographic perturbations) on the large scales of the flow and on the fluctuations in the wind turbine(s) power output.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011TCD.....5.1335C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011TCD.....5.1335C"><span id="translatedtitle">Warming of waters in an East Greenland fjord prior to glacier retreat: mechanisms and connection to large-scale <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christoffersen, P.; Mugford, R. I.; Heywood, K. J.; Joughin, I.; Dowdeswell, J. A.; Syvitski, J. P. M.; Luckman, A.; Benham, T. J.</p> <p>2011-05-01</p> <p>Hydrographic data acquired in Kangerlugssuaq Fjord and adjacent seas in 1993 and 2004 are used together with ocean reanalysis to elucidate water mass change and ice-ocean-<span class="hlt">atmosphere</span> interactions in East Greenland. The hydrographic data show substantial warming of fjord waters between 1993 and 2004 and warm subsurface <span class="hlt">conditions</span> coincide with the rapid retreat of Kangerlugssuaq Glacier in 2004-2005. The ocean reanalysis shows that the warm properties of fjord waters in 2004 are related to a major peak in oceanic shoreward heat flux into a cross-shelf trough on the outer continental shelf. The heat flux into this trough varies according to seasonal exchanges with the <span class="hlt">atmosphere</span> as well as from deep seasonal intrusions of subtropical waters. Both mechanisms contribute to high (low) shoreward heat flux when winds from the northeast are weak (strong). The combined effect of surface heating and inflow of subtropical waters is seen in the hydrographic data, which were collected after periods when along-shore coastal winds from the north were strong (1993) and weak (2004). We show that coastal winds vary according to the pressure gradient defined by a semi-permanent <span class="hlt">atmospheric</span> pressure system over Greenland and a persistent <span class="hlt">atmospheric</span> low situated near Iceland. The magnitude of this pressure gradient is controlled by longitudinal variability in the position of the Icelandic Low.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838827','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838827"><span id="translatedtitle">Cumulative early life <span class="hlt">adversity</span> predicts longevity in wild baboons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tung, Jenny; Archie, Elizabeth A.; Altmann, Jeanne; Alberts, Susan C.</p> <p>2016-01-01</p> <p>In humans and other animals, harsh circumstances in early life predict morbidity and mortality in adulthood. Multiple <span class="hlt">adverse</span> <span class="hlt">conditions</span> are thought to be especially toxic, but this hypothesis has rarely been tested in a prospective, longitudinal framework, especially in long-lived mammals. Here we use prospective data on 196 wild female baboons to show that cumulative early <span class="hlt">adversity</span> predicts natural adult lifespan. Females who experience ≥3 sources of early <span class="hlt">adversity</span> die a median of 10 years earlier than females who experience ≤1 <span class="hlt">adverse</span> circumstances (median lifespan is 18.5 years). Females who experience the most <span class="hlt">adversity</span> are also socially isolated in adulthood, suggesting that social processes partially explain the link between early <span class="hlt">adversity</span> and adult survival. Our results provide powerful evidence for the developmental origins of health and disease and indicate that close ties between early <span class="hlt">adversity</span> and survival arise even in the absence of health habit and health care-related explanations. PMID:27091302</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27091302','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27091302"><span id="translatedtitle">Cumulative early life <span class="hlt">adversity</span> predicts longevity in wild baboons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tung, Jenny; Archie, Elizabeth A; Altmann, Jeanne; Alberts, Susan C</p> <p>2016-01-01</p> <p>In humans and other animals, harsh circumstances in early life predict morbidity and mortality in adulthood. Multiple <span class="hlt">adverse</span> <span class="hlt">conditions</span> are thought to be especially toxic, but this hypothesis has rarely been tested in a prospective, longitudinal framework, especially in long-lived mammals. Here we use prospective data on 196 wild female baboons to show that cumulative early <span class="hlt">adversity</span> predicts natural adult lifespan. Females who experience ≥3 sources of early <span class="hlt">adversity</span> die a median of 10 years earlier than females who experience ≤1 <span class="hlt">adverse</span> circumstances (median lifespan is 18.5 years). Females who experience the most <span class="hlt">adversity</span> are also socially isolated in adulthood, suggesting that social processes partially explain the link between early <span class="hlt">adversity</span> and adult survival. Our results provide powerful evidence for the developmental origins of health and disease and indicate that close ties between early <span class="hlt">adversity</span> and survival arise even in the absence of health habit and health care-related explanations. PMID:27091302</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6590P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6590P"><span id="translatedtitle">Temperature dependence of carbon kinetic isotope effect for the oxidation reaction of ethane by OH radicals under <span class="hlt">atmospherically</span> relevant <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Piansawan, Tammarat; Saccon, Marina; Laumer, Werner; Gensch, Iulia; Kiendler-Scharr, Astrid</p> <p>2015-04-01</p> <p>Modeling of the global distribution of <span class="hlt">atmospheric</span> ethane sources and sinks by using the 13C isotopic composition requires accurate knowledge of the carbon kinetic isotope effect (KIE) of its <span class="hlt">atmospheric</span> removal reactions. The quantum mechanical prediction implies the necessity to elucidate the temperature dependence of KIE within <span class="hlt">atmospherically</span> relevant temperature range by experiment. In this study, the KIE and its temperature dependence for ethane oxidation by OH radicals was investigated at ambient pressure in a temperature range of 243 K to 303 K. The chemical reactions were carried out in a 15 L PFE reaction chamber, suspended in a thermally controlled oven. The isotope ratios of the gas phase components during the course of the reactions were measured by Thermal Desorption -- Gas Chromatography -- Isotope Ratio Mass Spectrometry (TD-GC-IRMS). For each temperature, the KIE was derived from the temporal evolution of the concentration and stable carbon isotope ratio (δ13C) of ethane using a method adapted from the relative reaction rate concept. The room temperature KIE of the ethane reaction with OH radicals was found to be 6.85 ± 0.32 ‰. This value is in agreement with the previously reported value of 8.57 ± 1.95 ‰ [Anderson et al. 2004] but has a substantially lower uncertainty. The experimental results will be discussed with the KIE temperature dependence predicted by quantum mechanical calculations. Reference: Rebecca S. Anderson, Lin Huang, Richard Iannone, Alexandra E. Thompson, and Jochen Rudolph (2004), Carbon Kinetic Isotope Effects in the Gas Phase Reactions of Light Alkanes and Ethene with the OH Radical at 296 ± 4 K, J. Phys. Chem. A, 108, 11537--11544</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/6995091','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/6995091"><span id="translatedtitle"><span class="hlt">Adverse</span> antibiotic drug interactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bint, A J; Burtt, I</p> <p>1980-07-01</p> <p>There is enormous potential for drug interactions in patients who, today, often receive many drugs. Antibiotics are prominent amongst the groups of drugs commonly prescribed. Many interactions take place at the absorption stage. Antacids and antidiarrhoeal preparations, in particular, can delay and reduce the absorption of antibiotics such as tetracyclines and clindamycin, by combining with them in the gastrointestinal tract to form chelates or complexes. Other drugs can affect gastric motility, which in turn often controls the rate at which antibiotics are absorbed. Some broad spectrum antibiotics can alter the bacterial flora of the gut which may be related to malabsorption states. The potentiation of toxic side effects of one drug by another is a common type of interaction. Antibiotics which are implicated in this type of interaction are those which themselves possess some toxicity such as aminoglycosides, some cephalosporins, tetracyclines and colistin. Some of the most important <span class="hlt">adverse</span> interactions with antibiotics are those which involve other drugs which have a low toxicity/efficacy ratio. These include anticoagulants such as warfarin, anticonvulsants such as phenytoin and phenobarbitone and oral antidiabetic drugs like tolbutamide. Risk of interaction arises when the metabolism of these drugs is inhibited by liver microsomal enzyme inhibitors such as some sulphonamides and chloramphenicol, or is enhanced by enzyme inducers such as rifampicin. PMID:6995091</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23850228','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23850228"><span id="translatedtitle">Enduring psychobiological effects of childhood <span class="hlt">adversity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ehlert, Ulrike</p> <p>2013-09-01</p> <p>This mini-review refers to recent findings on psychobiological long-term consequences of childhood trauma and <span class="hlt">adverse</span> living <span class="hlt">conditions</span>. The continuum of trauma-provoked aftermath reaches from healthy adaptation with high resilience, to severe maladjustment with co-occurring psychiatric and physical pathologies in children, adolescents and adults. There is increasing evidence of a strong interconnectivity between genetic dispositions, epigenetic processes, stress-related hormonal systems and immune parameters in all forms of (mal)-adjustment to <span class="hlt">adverse</span> living <span class="hlt">conditions</span>. Unfavorable constellations of these dispositions and systems, such as low cortisol levels and elevated markers of inflammation in maltreated children, seem to promote the (co)-occurrence of psychiatric and physical pathologies such as posttraumatic stress disorder, obesity, or diabetes. Although findings from prospective study designs support a deepened understanding of causal relations between <span class="hlt">adverse</span> living <span class="hlt">conditions</span>, including traumatic experiences, during childhood and its psychobiological effects, so far, little is known about the temporal coincidence of stress-sensitive developmental stages during childhood and adolescence and trauma consequences. Taken together, childhood <span class="hlt">adversity</span> is a severe risk factor for the onset of psychobiological (mal)-adjustment, which has to be explained under consideration of diverse physiological systems and developmental stages of childhood and adolescence. PMID:23850228</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRE..120.1298R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRE..120.1298R"><span id="translatedtitle">The Martian <span class="hlt">atmospheric</span> ion escape rate dependence on solar wind and solar EUV <span class="hlt">conditions</span>: 1. Seven years of Mars Express observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramstad, Robin; Barabash, Stas; Futaana, Yoshifumi; Nilsson, Hans; Wang, Xiao-Dong; Holmström, Mats</p> <p>2015-07-01</p> <p>More than 7 years of ion flux measurements in the energy range 10 eV-15 keV have allowed the ASPERA-3/IMA (Analyzer of Space Plasmas and Energetic Ions/Ion Mass Analyzer) instrument on Mars Express to collect a large database of ion measurements in the Mars environment, over a wide range of upstream solar wind (density and velocity) and radiation (solar EUV intensity) <span class="hlt">conditions</span>. We investigate the influence of these parameters on the Martian <span class="hlt">atmospheric</span> ion escape rate by integrating IMA heavy ion flux measurements taken in the Martian tail at similar (binned) solar wind density (nsw), velocity (vsw), and solar EUV intensity (IEUV) <span class="hlt">conditions</span>. For the same solar wind velocity and EUV intensity ranges (vsw and Is constrained), we find a statistically significant decrease of up to a factor of 3 in the <span class="hlt">atmospheric</span> ion escape rate with increased average solar wind density (5.6 × 1024s-1 to 1.9 × 1024s-1 for 0.4 cm-3 and 1.4 cm-3, respectively). For low solar wind density (0.1-0.5 cm-3) and low EUV intensity, the escape rate increases with increasing solar wind velocity from 2.4 × 1024s-1 to 5.6 × 1024s-1. During high solar EUV intensities the escape fluxes are highly variable, leading to large uncertainties in the estimated escape rates; however, a statistically significant increase in the escape rate is found between low/high EUV for similar solar wind <span class="hlt">conditions</span>. Empirical-analytical models for <span class="hlt">atmospheric</span> escape are developed by fitting calculated escape rates to all sufficiently sampled upstream <span class="hlt">conditions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A31F3085T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A31F3085T"><span id="translatedtitle">Ice nucleation by different types of soil dusts under mixed-phase cloud <span class="hlt">conditions</span>: Laboratory studies and <span class="hlt">atmospheric</span> implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tobo, Y.; DeMott, P. J.; Hill, T. C. J.; Prenni, A. J.; Swoboda-Colberg, N. G.; Franc, G. D.; Kreidenweis, S. M.</p> <p>2014-12-01</p> <p>It has been suggested that ice nucleation by desert soil dusts composed largely of minerals plays an important role in forming ice crystals in mixed-phase clouds and subsequent precipitation. More recently, several studies have suggested that soil dusts having higher contents of soil organic matter (SOM) may also contribute significantly to <span class="hlt">atmospheric</span> ice nucleation. In this study, we examine the ice nucleation properties of soil dusts derived from different locations in the world. Our results show that the ice nucleating ability of agricultural soil dusts derived from the largest dust source regions in North America is almost comparable to that of desert soil dusts at temperatures colder than about -15°C. We also confirm that the agricultural soil dusts can serve as effective ice nuclei (IN) at much warmer temperatures. On the other hand, our results indicate that the ice nucleating ability of the agricultural soil dusts is significantly reduced after H2O2 digestion, while the reduction is not significant for the desert soil dusts. In this regard, based on single particle analysis, we demonstrate that such a significant reduction observed in the agricultural soil dusts is mainly attributable to the removal of organic-rich particles (namely, SOM particles), which have much higher ice nucleating ability than mineral particles. Moreover, we discuss the potential contributions of these soil dusts to <span class="hlt">atmospheric</span> IN populations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26259971','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26259971"><span id="translatedtitle">A revised inventory of <span class="hlt">Adverse</span> Childhood Experiences.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Finkelhor, David; Shattuck, Anne; Turner, Heather; Hamby, Sherry</p> <p>2015-10-01</p> <p>This study examines whether the items from the original <span class="hlt">Adverse</span> Childhood Experiences (ACE) scale can be improved in their prediction of health outcomes by adding some additional widely recognized childhood <span class="hlt">adversities</span>. The analyses come from the National Survey of Children's Exposure to Violence 2014, a telephone survey conducted from August 2013 through April 2014 with a nationally representative sample of 1,949 children and adolescents aged 10-17 and their caregivers who were asked about <span class="hlt">adversities</span>, physical health <span class="hlt">conditions</span> and mental health symptoms. The addition of measures of peer victimization, peer isolation/rejection, and community violence exposure added significantly to the prediction of mental health symptoms, and the addition of a measure of low socioeconomic status (SES) added significantly to the prediction of physical health problems. A revised version of the ACES scale is proposed. PMID:26259971</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25078471','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25078471"><span id="translatedtitle">Near-field krypton-85 measurements in stable meteorological <span class="hlt">conditions</span> around the AREVA NC La Hague reprocessing plant: estimation of <span class="hlt">atmospheric</span> transfer coefficients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Connan, O; Solier, L; Hébert, D; Maro, D; Lamotte, M; Voiseux, C; Laguionie, P; Cazimajou, O; Le Cavelier, S; Godinot, C; Morillon, M; Thomas, L; Percot, S</p> <p>2014-11-01</p> <p>The aim of this work was to study the near-field dispersion of (85)Kr around the nuclear fuel reprocessing plant at La Hague (AREVA NC La Hague - France) under stable meteorological <span class="hlt">conditions</span>. Twenty-two (85)Kr night-time experimental campaigns were carried out at distances of up to 4 km from the release source. Although the operational Gaussian models predict for these meteorological <span class="hlt">conditions</span> a distance to plume touchdown of several kilometers, we almost systematically observed a marked ground signal at distances of 0.5-4 km. The calculated <span class="hlt">atmospheric</span> transfer coefficients (ATC) show values (1) higher than those observed under neutral <span class="hlt">conditions</span>, (2) much higher than those proposed by the operational models, and (3) higher than those used in the impact assessments. PMID:25078471</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21376732','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21376732"><span id="translatedtitle">Modelling the prey detection performance of Rhinonicteris aurantia (Chiroptera: Hipposideridae) in different <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> discounts the notional role of relative humidity in adaptive evolution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Armstrong, Kyle N; Kerry, Leonard J</p> <p>2011-06-01</p> <p>We examined a recent notion that differences in echolocation call frequency amongst geographic groups of constant frequency (CF)-emitting bats is the result of a trade-off between maximising prey detection range at lower frequencies and enhancing small-prey resolution at higher frequencies in different <span class="hlt">atmospheric</span> (relative humidity; RH) environments. Isolated populations of the endemic Australian orange leaf-nosed bat Rhinonicteris aurantia were used as an example since geographic isolation in different environments has been a precursor to differences in their characteristic echolocation call frequencies (mean difference c. 6 kHz; means of 114.64 and 120.99 kHz). The influence of both <span class="hlt">atmospheric</span> temperature and RH on maximum prey detection range was explored through mathematical modelling. This revealed that temperature was of similar importance to relative humidity and that under certain circumstances, each could reduce the effect of the other on ultrasound attenuation rates. The newly developed models contain significant conceptual improvements in method compared to other recent approaches, and can be applied to the situation of any other species of bat. For a given set of <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>, the prey detection range of R. aurantia was reduced slightly when call frequency increased by 6 kHz, but an increase in RH, temperature or both reduced detection range significantly. A similar trend was also evident in prey detection volume ratios calculated for the same <span class="hlt">conditions</span>. Spatial volume ratios were applied to assess the impact of changed <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> and prey size on foraging ecology. Reductions in detection range associated with increases in RH and/or temperature also varied in relation to the size (cross sectional area) of insect prey. Modelling demonstrated that small (6 kHz) movements in call frequency could not compensate for the changes in prey detection range and spatial detection volumes that result from significant changes in <span class="hlt">atmospheric</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080016475&hterms=PLAN+COMMUNICATION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPLAN%2BCOMMUNICATION','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080016475&hterms=PLAN+COMMUNICATION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPLAN%2BCOMMUNICATION"><span id="translatedtitle">Mitigating Aviation Communication and Satellite Orbit Operations Surprises from <span class="hlt">Adverse</span> Space Weather</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tobiska, W. Kent</p> <p>2008-01-01</p> <p><span class="hlt">Adverse</span> space weather affects operational activities in aviation and satellite systems. For example, large solar flares create highly variable enhanced neutral <span class="hlt">atmosphere</span> and ionosphere electron density regions. These regions impact aviation communication frequencies as well as precision orbit determination. The natural space environment, with its dynamic space weather variability, is additionally changed by human activity. The increase in orbital debris in low Earth orbit (LEO), combined with lower <span class="hlt">atmosphere</span> CO2 that rises into the lower thermosphere and causes increased cooling that results in increased debris lifetime, adds to the environmental hazards of navigating in near-Earth space. This is at a time when commercial space endeavors are posed to begin more missions to LEO during the rise of the solar activity cycle toward the next maximum (2012). For satellite and aviation operators, <span class="hlt">adverse</span> space weather results in greater expenses for orbit management, more communication outages or aviation and ground-based high frequency radio used, and an inability to effectively plan missions or service customers with space-based communication, imagery, and data transferal during time-critical activities. Examples of some revenue-impacting <span class="hlt">conditions</span> and solutions for mitigating <span class="hlt">adverse</span> space weather are offered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.H21A0699C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.H21A0699C&link_type=ABSTRACT"><span id="translatedtitle">Interaction Between CO2-Rich Sulfate Solutions and Carbonate Reservoir Rocks from <span class="hlt">Atmospheric</span> to Supercritical CO2 <span class="hlt">Conditions</span>: Experiments and Modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cama, J.; Garcia-Rios, M.; Luquot, L.; Soler Matamala, J. M.</p> <p>2014-12-01</p> <p>A test site for CO2 geological storage is situated in Hontomín (Spain) with a reservoir rock that is mainly composed of limestone. During and after CO2 injection, the resulting CO2-rich acid brine gives rise to the dissolution of carbonate minerals (calcite and dolomite) and gypsum (or anhydrite at depth) may precipitate since the reservoir brine contains sulfate. Experiments using columns filled with crushed limestone or dolostone were conducted under different P-pCO2 <span class="hlt">conditions</span> (<span class="hlt">atmospheric</span>: 1-10-3.5 bar; subcritical: 10-10 bar; and supercritical: 150-34 bar), T (25, 40 and 60 ºC) and input solution compositions (gypsum-undersaturated and gypsum-equilibrated solutions). We evaluated the effect of these parameters on the coupled reactions of calcite/dolomite dissolution and gypsum/anhydrite precipitation. The CrunchFlow and PhreeqC (v.3) numerical codes were used to perform reactive transport simulations of the experiments. Under the P-pCO2-T <span class="hlt">conditions</span>, the volume of precipitated gypsum was smaller than the volume of dissolved carbonate minerals, yielding an increase in porosity (Δporosity up to ≈ 4%). A decrease in T favored limestone dissolution regardless of pCO2 owing to increasing undersaturation with decreasing temperature. However, gypsum precipitation was favored at high T and under <span class="hlt">atmospheric</span> pCO2 <span class="hlt">conditions</span> but not at high T and under 10 bar of pCO2 <span class="hlt">conditions</span>. The increase in limestone dissolution with pCO2 was directly attributed to pH, which was more acidic at higher pCO2. Increasing pCO2, carbonate dissolution occurred along the column whereas it was localized in the very inlet under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>. This was due to the buffer capacity of the carbonic acid, which maintains pH at around 5 and keeps the solution undersaturated with respect to calcite and dolomite along the column. 1D reactive transport simulations reproduced the experimental data (carbonate dissolution and gypsum precipitation for different P-pCO2-T <span class="hlt">conditions</span>). Drawing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1127267','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1127267"><span id="translatedtitle">Using Mesoscale Weather Model Output as Boundary <span class="hlt">Conditions</span> for <span class="hlt">Atmospheric</span> Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.</p> <p>2013-10-01</p> <p>Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the <span class="hlt">atmospheric</span> boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the <span class="hlt">atmospheric</span> stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale <span class="hlt">atmospheric</span> large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary <span class="hlt">conditions</span> to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP43A0959B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP43A0959B"><span id="translatedtitle">Aeolian deposition change in the Peruvian central continental shelf during the last millennium and its relationship with <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Briceño, F. J., Sr.; Sifeddine, A.</p> <p>2015-12-01</p> <p>We present a record of laminated sediment cores retrieved in the Pisco region (14 °S) characterized by local aeolian inputs. This record covers the Medieval Climate Anomaly (MCA) to Little Ice Age (LIA) and the Current Warm Period (CWP) at centennial to sub-decadal resolution. The aim of the study is to reconstruct the patterns of aeolian sedimentation as well as the most important processes that control the input of this material to understand how these components reflect <span class="hlt">atmospheric</span> climate variability during the last millennium. Assuming that the mineral fraction of the sediment is composed of several lognormally distributed particle populations, we applied an iterative least-square fitting routine to determine the number and the characteristics of the individual particles populations. This allows inferring the spatial and temporal variation of particles populations and thus transport mechanisms involved. Two components with grain size modes at 54±11 μm and 90±11 μm related with local aeolian erosion over the Pisco region were found. Our results showed active aeolian erosion during the second half of the MCA and rapid decrease from the MCA to the LIA. During the LIA the aeolian deposition exhibited a decreasing activity. During the CWP the aeolian deposition increased progressively. Comparison with others South American records indicates that those changes are linked to change in the meridional position of the Intertropical convergence zone (ITCZ) and South Pacific Subtropical High (SPSH) at the centennial time resolution. Finally the CWP period showed an increase in the aeolian deposition and thus in the wind intensity over the past two centuries. This likely represents the result of the modern position of the ITCZ-SPSH system and the associated intensification of the local and regional winds. Nevertheless, the aeolian deposition and in consequence the wind intensity and variability of the last 100 yr are stronger than during the second sequence of the MCA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=185544&keyword=che&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67277935&CFTOKEN=85356765','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=185544&keyword=che&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67277935&CFTOKEN=85356765"><span id="translatedtitle">SCIENTIFIC UNCERTAINTIES IN <span class="hlt">ATMOSPHERIC</span> MERCURY MODELS III: BOUNDARY AND INITIAL <span class="hlt">CONDITIONS</span>, MODEL GRID RESOLUTION, AND HG(II) REDUCTION MECHANISMS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>In this study we investigate the CMAQ model response in terms of simulated mercury concentration and deposition to boundary/initial <span class="hlt">conditions</span> (BC/IC), model grid resolution (12- versus 36-km), and two alternative Hg(II) reduction mechanisms. The model response to the change of g...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/931353','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/931353"><span id="translatedtitle">Direct and indirect effects of <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> and soil moisture on surface energy partitioning revealed by a prolonged drought at a temperate forest site</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gu, Lianhong; Meyers, T. P.; Pallardy, Stephen G.; Hanson, Paul J; Yang, Bai; Heuer, Mark; Hosman, K. P.; Riggs, Jeffery S; Sluss, Daniel Wayne; Wullschleger, Stan D</p> <p>2006-01-01</p> <p>The purpose of this paper is to examine the mechanism that controls the variation of surface energy partitioning between latent and sensible heat fluxes at a temperate deciduous forest site in central Missouri, USA. Taking advantage of multiple micrometeorological and ecophysiological measurements and a prolonged drought in the middle of the 2005 growing season at this site, we studied how soil moisture, <span class="hlt">atmospheric</span> vapor pressure deficit (VPD), and net radiation affected surface energy partitioning. We stratified these factors to minimize potential confounding effects of correlation among them. We found that all three factors had direct effects on surface energy partitioning, but more important, all three factors also had crucial indirect effects. The direct effect of soil moisture was characterized by a rapid decrease in Bowen ratio with increasing soil moisture when the soil was dry and by insensitivity of Bowen ratio to variations in soil moisture when the soil was wet. However, the rate of decrease in Bowen ratio when the soil was dry and the level of soil moisture above which Bowen ratio became insensitive to changes in soil moisture depended on <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>. The direct effect of increased net radiation was to increase Bowen ratio. The direct effect of VPD was very nonlinear: Increased VPD decreased Bowen ratio at low VPD but increased Bowen ratio at high VPD. The indirect effects were much more complicated. Reduced soil moisture weakened the influence of VPD but enhanced the influence of net adiation on surface energy partitioning. Soil moisture also controlled how net radiation influenced the relationship between surface energy partitioning and VPD and how VPD affected the relationship between surface energy partitioning and net radiation. Furthermore, both increased VPD and increased net radiation enhanced the sensitivity of Bowen ratio to changes in soil moisture and the effect of drought on surface energy partitioning. The direct and indirect</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED034696.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED034696.pdf"><span id="translatedtitle"><span class="hlt">Adverse</span> Reactions to Hallucinogenic Drugs.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Meyer, Roger E. , Ed.</p> <p></p> <p>This reports a conference of psychologists, psychiatrists, geneticists and others concerned with the biological and psychological effects of lysergic acid diethylamide and other hallucinogenic drugs. Clinical data are presented on <span class="hlt">adverse</span> drug reactions. The difficulty of determining the causes of <span class="hlt">adverse</span> reactions is discussed, as are different…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760048326&hterms=ny+state+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dny%2Bstate%2Blaw','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760048326&hterms=ny+state+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dny%2Bstate%2Blaw"><span id="translatedtitle">Laws of effluent dispersion in the steady-state <span class="hlt">atmospheric</span> surface layer in stable and unstable <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lebedeff, S. A.; Hameed, S.</p> <p>1976-01-01</p> <p>The two-dimensional diffusion equation has been solved by an integral method to obtain the distribution of ground-level concentration of an inert effluent emitted from a semi-infinite area source in a steady-state and horizontally homogeneous <span class="hlt">atmospheric</span> surface layer. Mean wind velocity and eddy diffusivity profiles derived from empirically determined flux-profile relations of Businger et al. (1971) for stable and unstable surface layers were used. It is found that concentration as a function of downwind distance can be described by a simple formula over distances of practical interest in surface layer dispersion. Corresponding results for a cross-wind infinite line source are obtained by simple differentiation. The concentration distribution is completely determined by the friction velocity, the Monin-Obukhov length, the roughness length, and the effluent source strength. The generalization of the integral method needed to obtain accurate solutions of the diffusion equation with the given wind velocity and diffusivity profiles is discussed in an appendix.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4052457','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4052457"><span id="translatedtitle">Responses of sap flow, leaf gas exchange and growth of hybrid aspen to elevated <span class="hlt">atmospheric</span> humidity under field <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Niglas, Aigar; Kupper, Priit; Tullus, Arvo; Sellin, Arne</p> <p>2014-01-01</p> <p>An increase in average air temperature and frequency of rain events is predicted for higher latitudes by the end of the 21st century, accompanied by a probable rise in air humidity. We currently lack knowledge on how forest trees acclimate to rising air humidity in temperate climates. We analysed the leaf gas exchange, sap flow and growth characteristics of hybrid aspen (Populus tremula × P. tremuloides) trees growing at ambient and artificially elevated air humidity in an experimental forest plantation situated in the hemiboreal vegetation zone. Humidification manipulation did not affect the photosynthetic capacity of plants, but did affect stomatal responses: trees growing at elevated air humidity had higher stomatal conductance at saturating photosynthetically active radiation (gs sat) and lower intrinsic water-use efficiency (IWUE). Reduced stomatal limitation of photosynthesis in trees grown at elevated air humidity allowed slightly higher net photosynthesis and relative current-year height increments than in trees at ambient air humidity. Tree responses suggest a mitigating effect of higher air humidity on trees under mild water stress. At the same time, trees at higher air humidity demonstrated a reduced sensitivity of IWUE to factors inducing stomatal closure and a steeper decline in canopy conductance in response to water deficit, implying higher dehydration risk. Despite the mitigating impact of increased air humidity under moderate drought, a future rise in <span class="hlt">atmospheric</span> humidity at high latitudes may be disadvantageous for trees during weather extremes and represents a potential threat in hemiboreal forest ecosystems. PMID:24887000</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24887000','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24887000"><span id="translatedtitle">Responses of sap flow, leaf gas exchange and growth of hybrid aspen to elevated <span class="hlt">atmospheric</span> humidity under field <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Niglas, Aigar; Kupper, Priit; Tullus, Arvo; Sellin, Arne</p> <p>2014-01-01</p> <p>An increase in average air temperature and frequency of rain events is predicted for higher latitudes by the end of the 21st century, accompanied by a probable rise in air humidity. We currently lack knowledge on how forest trees acclimate to rising air humidity in temperate climates. We analysed the leaf gas exchange, sap flow and growth characteristics of hybrid aspen (Populus tremula × P. tremuloides) trees growing at ambient and artificially elevated air humidity in an experimental forest plantation situated in the hemiboreal vegetation zone. Humidification manipulation did not affect the photosynthetic capacity of plants, but did affect stomatal responses: trees growing at elevated air humidity had higher stomatal conductance at saturating photosynthetically active radiation (gs sat) and lower intrinsic water-use efficiency (IWUE). Reduced stomatal limitation of photosynthesis in trees grown at elevated air humidity allowed slightly higher net photosynthesis and relative current-year height increments than in trees at ambient air humidity. Tree responses suggest a mitigating effect of higher air humidity on trees under mild water stress. At the same time, trees at higher air humidity demonstrated a reduced sensitivity of IWUE to factors inducing stomatal closure and a steeper decline in canopy conductance in response to water deficit, implying higher dehydration risk. Despite the mitigating impact of increased air humidity under moderate drought, a future rise in <span class="hlt">atmospheric</span> humidity at high latitudes may be disadvantageous for trees during weather extremes and represents a potential threat in hemiboreal forest ecosystems. PMID:24887000</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...573A..72G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...573A..72G"><span id="translatedtitle">Pre-<span class="hlt">conditioned</span> backward Monte Carlo solutions to radiative transport in planetary <span class="hlt">atmospheres</span>. Fundamentals: Sampling of propagation directions in polarising media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>García Muñoz, A.; Mills, F. P.</p> <p>2015-01-01</p> <p>Context. The interpretation of polarised radiation emerging from a planetary <span class="hlt">atmosphere</span> must rely on solutions to the vector radiative transport equation (VRTE). Monte Carlo integration of the VRTE is a valuable approach for its flexible treatment of complex viewing and/or illumination geometries, and it can intuitively incorporate elaborate physics. Aims: We present a novel pre-<span class="hlt">conditioned</span> backward Monte Carlo (PBMC) algorithm for solving the VRTE and apply it to planetary <span class="hlt">atmospheres</span> irradiated from above. As classical BMC methods, our PBMC algorithm builds the solution by simulating the photon trajectories from the detector towards the radiation source, i.e. in the reverse order of the actual photon displacements. Methods: We show that the neglect of polarisation in the sampling of photon propagation directions in classical BMC algorithms leads to unstable and biased solutions for conservative, optically-thick, strongly polarising media such as Rayleigh <span class="hlt">atmospheres</span>. The numerical difficulty is avoided by pre-<span class="hlt">conditioning</span> the scattering matrix with information from the scattering matrices of prior (in the BMC integration order) photon collisions. Pre-<span class="hlt">conditioning</span> introduces a sense of history in the photon polarisation states through the simulated trajectories. Results: The PBMC algorithm is robust, and its accuracy is extensively demonstrated via comparisons with examples drawn from the literature for scattering in diverse media. Since the convergence rate for MC integration is independent of the integral's dimension, the scheme is a valuable option for estimating the disk-integrated signal of stellar radiation reflected from planets. Such a tool is relevant in the prospective investigation of exoplanetary phase curves. We lay out two frameworks for disk integration and, as an application, explore the impact of <span class="hlt">atmospheric</span> stratification on planetary phase curves for large star-planet-observer phase angles. By construction, backward integration provides a better</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006Icar..185..143S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006Icar..185..143S"><span id="translatedtitle">Interactive effects of hypobaria, low temperature, and CO 2 <span class="hlt">atmospheres</span> inhibit the growth of mesophilic Bacillus spp. under simulated martian <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schuerger, Andrew C.; Nicholson, Wayne L.</p> <p>2006-11-01</p> <p>Robotic spacecraft are launched with finite levels of terrestrial microorganisms that are similar to the microbial communities within facilities in which spacecraft are assembled. In particular, spores of mesophilic aerobic Bacillus species are common spacecraft contaminants considered most likely to survive interplanetary transfer to Mars. During the cruise phase to Mars, and then again during surface operations, microbial bioloads are exposed to a diversity of biocidal factors that are likely to render the microbial species either dead or significantly inhibited from active metabolic activity and replication. We report here, for the first time, that interactive effects of low pressure, low temperature, and high CO 2 <span class="hlt">atmospheres</span> approaching <span class="hlt">conditions</span> likely to be encountered on the martian surface strongly inhibit the growth and replication of seven common Bacillus spp. isolated from spacecraft. Tests were conducted within a small glass bell-jar system maintained in a low-temperature microbial incubator. <span class="hlt">Atmospheric</span> pressures were controlled at 1013 (Earth-normal), 100, 50, 35, 25, or 15 mb, and temperatures were maintained at 30, 20, 15, 10, or 5 °C. Experiments were carried out for 48 h or 7 days under either Earth-normal O 2/N 2 or pure CO 2 <span class="hlt">atmospheres</span>. Results indicated that low pressure, low temperature, and high CO 2 <span class="hlt">atmospheres</span>, applied separately or in combination, were capable of inhibiting the growth and replication of B. pumilus SAFR-032, B. pumilus FO-36B, B. subtilis HA-101, B. subtilis 42HS-1, B. megaterium KL-197, B. licheniformis KL-196, and B. nealsonii FO-092 under simulated martian <span class="hlt">conditions</span>. Endospores of all seven Bacillus spp. strains failed to germinate and grow at 25 mb at 30 °C. Although, vegetative cells of these strains exhibited a slightly greater ability to replicate at lower pressures than did endospores, vegetative cells of these species failed to grow at pressures below 25 mb. Interactive effects of these environmental</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820061908&hterms=red+sun&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dred%2Bsun','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820061908&hterms=red+sun&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dred%2Bsun"><span id="translatedtitle">Effect of sun and sensor geometry, canopy structure and density, and <span class="hlt">atmospheric</span> <span class="hlt">condition</span> on the spectral response of vegetation, with particular emphasis on across-track pointing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schnetzler, C. C.</p> <p>1981-01-01</p> <p>A computer modeling and simulation study carried out to assess the effects of various sun and sensor geometries and <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> on the directional reflected radiance of several vegetated targets is described. Spectral responses at two wavelengths, 0.68 micron and 0.80 micron, are simulated at nine sensor zenith angles, five sensor azimuths, and nine solar zenith angles for six vegetation canopies under three atmspheric <span class="hlt">conditions</span>. The six canopies comprise two different geometries of grass canopies at low, medium, and high leaf density. The results suggest that off-nadir viewing effects are more pronounced in the red than in the IR. However, the use of such transformations as the normalized difference index is found to reduce much of the variability seen in the bands. The magnitude of off-nadir viewing effects is found to be a function of canopy geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmRe.154...60C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmRe.154...60C"><span id="translatedtitle"><span class="hlt">Atmospheric</span> <span class="hlt">conditions</span> of thunderstorms in the European part of the Arctic derived from sounding and reanalysis data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czernecki, Bartosz; Taszarek, Mateusz; Kolendowicz, Leszek; Szyga-Pluta, Katarzyna</p> <p>2015-03-01</p> <p>While thunderstorms in equatorial and mid-latitudes are well documented, little is known about their presence in high latitudes. There are barely a few studies on this phenomenon analyzing their occurrence in the European Arctic region. In an attempt to rectify this situation authors aim to explain which <span class="hlt">conditions</span> are conducive to their formation in Bjørnøya, Jan Mayen and Svalbard islands. A total of 41 thunderstorm days derived from SYNOP reports from the period of 1981-2010 were used to define thunderstorm-favorable synoptic <span class="hlt">conditions</span> from NCEP/NCAR reanalyses and sounding data. In order to underline seasonal variation, anomalies were presented in the polar day and polar night timeframes. As it turned out polar night thunderstorms occur most often in situations with southern warm marine air advections intensified by the positive North Atlantic and Arctic Oscillations. Thunderstorms in this season are characterized by steep vertical lapse rates and occur most likely at the cold fronts. Polar day thunderstorms form when warm air masses move from the continental north-eastern Europe to the Arctic, and create unstable <span class="hlt">conditions</span>. In this type, thunderstorms are generated by elevated convection and occur most likely in a cyclone's cool side of warm sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24820661','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24820661"><span id="translatedtitle">Variation of crack intensity factor in three compacted clay liners exposed to annual cycle of <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> with and without geotextile cover.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Safari, E; Jalili Ghazizade, M; Abduli, M A; Gatmiri, B</p> <p>2014-08-01</p> <p>Performance of compacted clay liners commonly used as landfill barrier systems can be subject to decline in terms of hydraulic conductivity if left exposed to <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> for an extended period of time prior to placement of overlaying layers. The resulting desiccation cracking can lead to increased hydraulic conductivity. Desiccation crack intensity was studied for three clayey soils commonly used for construction of landfill barrier system in a relatively large scale test setup exposed to real time <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> over a complete annual cycle. A white separator geotextile cover was presumed to be capable of reducing the intensity of desiccation cracking through absorbing and maintaining higher amounts of moisture and reducing the temperature of the soil surface in comparison to a directly exposed soil surface. Desiccation cracking was monitored using a digital imaging technique for three compacted clay liners in two sets, one open to air and the second covered with the white geotextile. Crack intensity factor approached a relatively stable phase after certain cycles corresponding to <span class="hlt">atmospheric</span> dry wet cycles. The results indicated that the white separator geotextile was capable of reducing the crack intensity factor by 37.4-45.9% throughout the experiment including the cyclic phase of desiccation cracking. During the stable phase, the maximum reduction in crack intensity factor of 90.4% as a result of applying geotextile cover was observed for the soil with the lowest plastic index and clay content and therefore the lowest magnitude of crack intensity factor. The other two soils with similar clay content but different plastic index showed 23.6% and 52.2% reductions in crack intensity factor after cyclic phase when covered with geotextile. PMID:24820661</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998AtmEn..32.1765K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998AtmEn..32.1765K"><span id="translatedtitle">Exchange of <span class="hlt">atmospheric</span> formic and acetic acids with trees and crop plants under controlled chamber and purified air <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kesselmeier, J.; Bode, K.; Gerlach, C.; Jork, E.-M.</p> <p></p> <p>We investigated the exchange of formic and acetic acids between the <span class="hlt">atmosphere</span> and various tree species such as beech ( Fagus sylvatica L.), ash ( Fraxinus excelsior L.), spruce ( Picea abies L.) Karst, holm oak ( Quercus ilex L.), and birch ( Betula pendula L.). and some crop-plant species such as corn ( Zea mays, var. Banjo), pea ( Pisum sativum, var. Solara), barley ( Hordeum vulgare, var. Igri) and oat (Avena sativa, var. Wiesel). All experiments were done with dynamic enclosures flushed with purified oxidant-free air, containing only low or controlled amounts of the two acids. Significant and light-triggered emission of both acids from all tree species was observed. For one tree species (ash) a seasonal large increase in fall due to early leaf decomposition was found. The standard emission factors (30°C and PAR=1000 μmol m 2 s -1) given as (nmol m -2 min -1) for acetic and formic acids, respectively, were 8.1 and 29.7 (ash, autumn), 1.0 and 3.3 (ash, summer), 0.9 and 1.4 (beech), 0.7 and 1.45 (spruce), 1.9 and 2.4 (Holm oak) and 1.7 and 6.7 (birch). Rough estimation of global annual emissions range between 20 and 130 Gmol formic acid and 10 and 33 Gmol acetic acid. These numbers reflect a 15-30% contribution by forest emissions to the continental organic acid budget. As compared to the global total NMHC emissions low molecular weight organic acids are of minor importance. In contrast to the trees, none of the crop-plant species investigated showed an emission, but always a clear deposition of both acids. Both emission from trees as well as uptake by the agricultural plants could be related to transpiration rates and leaf conductances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9103E..0OA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9103E..0OA"><span id="translatedtitle">Features and range of the FSO by use of the OFDM and QAM modulation in different <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andrej, Liner; Perecar, Frantisek; Jaros, Jakub; Papes, Martin; Koudelka, Petr; Latal, Jan; Cubik, Jakub; Vasinek, Vladimir</p> <p>2014-05-01</p> <p>The FSO (Free Space Optics) communication uses the visible or infrared light for transmission. As well as cable optics FSO also uses laser for the data transmission, but the data flow is not transmitted in the fiber but in the air. This technology does not require expensive fiber optic cables and or ensure the licensing zone as it is in the case of radio networks. As well as in the cable transmissions are different modulations used. Nowadays, the most used modulations are QAM and OFDM. OFDM belongs to the border group of modulations with more carrier waves, where the information's are transmitted via subcarrier waves with lower data flow and baud rate. It is mainly used in broadband wire and wireless communications. OFDM provides very high signal resistance against the interference, chromatic dispersion (CD) and polarization mode dispersion (PMD)[l]. Modulation method involves the use of several hundreds to thousands of subcarrier waves. QAM is a composite modulation, which uses for symbol creation the combination of ASK (Amplitude Shift Keying) and PSK (Phase Shift Keying). Each state is represented by a specific value of the amplitude and phase. It's actually multistate modulation, which is able to transmit n bits by m symbols. That means that more bits are transferred at one moment. This paper deals with the modulations used in FSO. Most used modulation in FSO is OOK (On-Off Keying) , but modulations OFDM and QAM are (modulation ) ways of the future. The main task was to determine how much is the reach of modulations changing with the changes of density (visibility) of fog and the set transceiver power. As software environment for simulations has been used OptiSystem program. For the simulation of the <span class="hlt">atmosphere</span> the FSO component has been used. In this component were simulated attenuations, which are responding to varying densities of fog [2]. At different intensities of fog were changing the received power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23210223','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23210223"><span id="translatedtitle">A comparative study on the varying exposure to <span class="hlt">atmospheric</span> fine and coarse particles under urban and rural <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wolf-Benning, Uta; Schultz, Eckart; Dietze, Volker; Kaminski, Uwe; Endlicher, Wilfried</p> <p>2012-11-01</p> <p>This paper is based on the results of three air quality studies conducted in Buenos Aires in Berlin, and in German spas between 2003 and 2007. A high comparability of results was ensured by using the same sampling techniques and analytical methods. Total particle sampling was achieved by active sampling of fine (PM2.5) and passive sampling of coarse particles > or = 2.5 microm and giant particles > or = 10 microm. The highly absorbing, black, predominantly carbonaceous particles (BC) of fine particle samples were determined by measuring the total light attenuation of filter samples and interpreting the extinction value as black carbon. The difference between the gravimetric total mass concentration of the PM2.5 samples and the BC is defined as the transparent, mostly mineral fine fraction. In coarse/giant particle samples the mean gray value was determined by means of automated light microscopy with subsequent single-particle analysis. "Opaque" particles were separated from the "transparent" particle fraction by applying a grey value threshold level. Microscopic measurement of individual particles was employed to establish the size distribution of the coarse and giant fraction. Due to different health effects, the separate detection of these components is suggested. Decline functions of particles are given, possibly providing useful information for a more detailed specification of the local particle distribution, and for a better estimate of the individual exposure. <span class="hlt">Atmospheric</span> dispersal of particles was found effected mainly by source characteristics. An increased, spatially largely constant level of fine transparent particles in Berlin indicates a particle plume originating from photochemical processes. Buenos Aires, in contrast, is characterized by a lower background level of fine transparent particles but is considerably affected by fine black particles from diesel emissions and by a higher resuspension of coarse/giant transparent, mainly soil particles. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22271253','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22271253"><span id="translatedtitle">Analysis and experimental study on formation <span class="hlt">conditions</span> of large-scale barrier-free diffuse <span class="hlt">atmospheric</span> pressure air plasmas in repetitive pulse mode</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Li, Lee Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang</p> <p>2014-01-14</p> <p><span class="hlt">Atmospheric</span> air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse <span class="hlt">atmospheric</span> plasmas in open air should meet the three <span class="hlt">conditions</span>: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation <span class="hlt">conditions</span> of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014JAP...115b3301L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014JAP...115b3301L&link_type=ABSTRACT"><span id="translatedtitle">Analysis and experimental study on formation <span class="hlt">conditions</span> of large-scale barrier-free diffuse <span class="hlt">atmospheric</span> pressure air plasmas in repetitive pulse mode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Lee; Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang</p> <p>2014-01-01</p> <p><span class="hlt">Atmospheric</span> air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse <span class="hlt">atmospheric</span> plasmas in open air should meet the three <span class="hlt">conditions</span>: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation <span class="hlt">conditions</span> of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJWC..8902003F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJWC..8902003F"><span id="translatedtitle"><span class="hlt">Atmospheric</span> monitoring in MAGIC and data corrections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fruck, Christian; Gaug, Markus</p> <p>2015-03-01</p> <p>A method for analyzing returns of a custom-made "micro"-LIDAR system, operated alongside the two MAGIC telescopes is presented. This method allows for calculating the transmission through the <span class="hlt">atmospheric</span> boundary layer as well as thin cloud layers. This is achieved by applying exponential fits to regions of the back-scattering signal that are dominated by Rayleigh scattering. Making this real-time transmission information available for the MAGIC data stream allows to apply <span class="hlt">atmospheric</span> corrections later on in the analysis. Such corrections allow for extending the effective observation time of MAGIC by including data taken under <span class="hlt">adverse</span> <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>. In the future they will help reducing the systematic uncertainties of energy and flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H41J..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H41J..01S"><span id="translatedtitle">An Experimental and Modeling Study of Evaporation from Bare Soils Subjected to Natural Boundary <span class="hlt">Conditions</span> at the Land-<span class="hlt">Atmospheric</span> Interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smits, K. M.; Ngo, V. V.; Cihan, A.; Sakaki, T.; Illangasekare, T. H.; kathleen m smits</p> <p>2011-12-01</p> <p>Bare soil evaporation is a key process for water exchange between the land and the <span class="hlt">atmosphere</span> and an important component of the water balance in semiarid and arid regions. However, there is no agreement on the best methodology to determine evaporation under different boundary <span class="hlt">conditions</span>. Because it is difficult to measure evaporation from soil,with the exception of using lysimeters, numerous formulations have been proposed to establish a relationship between the rate of evaporation and soil moisture and/or soil temperature and thermal properties. Different formulations vary in how they partition available energy and include, among others, a classical bulk aerodynamic formulation which requires knowledge of the relative humidity at the soil surface and a more non-traditional heat balance method which requires knowledge of soil temperature and soil thermal properties. A need exists to systematically compare existing methods to experimental data under highly controlled <span class="hlt">conditions</span> not achievable in the field. The goal of this work is to perform controlled experiments under transient <span class="hlt">conditions</span> of soil moisture, temperature and wind at the land/<span class="hlt">atmospheric</span> interface to test different conceptual and mathematical formulations for evaporation rate estimates and to develop appropriate numerical models to be used in simulations. In this study, to better understand the coupled water-vapor-heat flow processes in the shallow subsurface near the land surface, we modified a previously developed theory that allows non-equilibrium liquid/gas phase change with gas phase vapor diffusion to better account for evaporation under dry soil <span class="hlt">conditions</span>. This theory was used to compare estimates of evaporation based on different formulations of the bulk aerodynamic and heat balance methods. In order to experimentally validate the numerical formulations/code, we performed a series of two-dimensional physical model experiments under varying boundary <span class="hlt">conditions</span> using test sand for which the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011TCD.....5..885D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011TCD.....5..885D"><span id="translatedtitle">A spatial framework for assessing current <span class="hlt">conditions</span> and monitoring future change in the chemistry of the Antarctic <span class="hlt">atmosphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dixon, D. A.; Mayewski, P. A.; Korotkikh, E.; Sneed, S. B.; Handley, M. J.; Introne, D. S.; Scambos, T. A.</p> <p>2011-03-01</p> <p> East and West Antarctica and for a significant fraction of the Cd in East Antarctica. Nonetheless, global volcanic outgassing cannot account for the enriched values of Pb or As. Local volcanic outgassing from Mount Erebus may account for a significant fraction of the As and Cd in West Antarctica and for a significant fraction in East Antarctic glaze/dune areas. However, despite potential contributions from local and global volcanic sources, significant concentrations of Pb, Cd, and As remain across much of Antarctica. Most importantly, this study provides a baseline from which changes in the chemistry of the <span class="hlt">atmosphere</span> over Antarctica can be monitored under expected warming scenarios and continued intensification of industrial activities in the Southern Hemisphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRD..121.1043W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRD..121.1043W"><span id="translatedtitle"><span class="hlt">Atmospheric</span> <span class="hlt">conditions</span> in the central Arctic Ocean through the melt seasons of 2012 and 2013: Impact on surface <span class="hlt">conditions</span> and solar energy deposition into the ice-ocean system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Caixin; Granskog, Mats A.; Hudson, Stephen R.; Gerland, Sebastian; Pavlov, Alexey K.; Perovich, Donald K.; Nicolaus, Marcel</p> <p>2016-02-01</p> <p>Spectral Radiation Buoys and ice mass balance buoys were deployed on first-year ice near the North Pole in April 2012 and 2013, collecting in-band (350-800 nm) solar radiation and ice and snow mass balance data over the complete summer melt seasons. With complementary European ERA-Interim reanalysis, National Centers for Environmental Prediction (NCEP) Climate forecast system version 2 (CFSv2) analysis and satellite passive microwave data, we examine the evolution of <span class="hlt">atmospheric</span> and surface melt <span class="hlt">conditions</span> in the two differing melt seasons. Prevailing <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> contributed to a longer and more continuous melt season in summer 2012 than in 2013, which was corroborated by in situ observations. ERA-Interim reanalysis data showed that longwave radiation likely played a key role in delaying the snowmelt onset in 2013. The earlier melt onset in 2012 reduced the albedo, providing a positive ice-albedo feedback at a time when solar insolation was high. Due to earlier melt onset and later freeze-up in 2012, more solar heat was deposited into the ice-ocean system than in 2013. Summer 2013 was characterized by later melt onset, intermittent freezing events and an earlier fall freeze-up, resulting in considerably fewer effective days of surface melt and a higher average albedo. Calculations for idealized seasonal albedo evolution show that moving the melt onset just 1 week earlier in mid-June increases the total absorbed solar radiation by nearly 14% for the summer season. Therefore, the earlier melt onset may have been one of the most important factors driving the more dramatic melt season in 2012 than 2013, though <span class="hlt">atmospheric</span> circulation patterns, e.g., cyclone in early August 2012, likely contributed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711144B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711144B"><span id="translatedtitle">The impacts of the North American ice-sheet on glaciation <span class="hlt">conditions</span> over northern Europe: an <span class="hlt">atmospheric</span> circulation study with the LMDZ model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beghin, Pauline; Charbit, Sylvie; Kageyama, Masa; Dumas, Christophe</p> <p>2015-04-01</p> <p>During the last glacial period (ca. 21 000 years ago), two continental-scale ice sheets covered Canada and northern Europe. It is now widely acknowledged that these past ice sheets exerted a strong influence on climate by causing changes in <span class="hlt">atmospheric</span> and oceanic circulations. In turn, these changes may have impacted the development of the ice sheets themselves through a combination of different feedback mechanisms. The present study is designed to investigate the potential impact of the North American ice sheet on the surface mass balance (SMB) of the Eurasian ice sheet through simulated changes in the past glacial <span class="hlt">atmospheric</span> circulation. Using the LMDz5 <span class="hlt">atmospheric</span> circulation model, we carried out twelve experiments run under constant Last Glacial Maximum (LGM) <span class="hlt">conditions</span> for insolation, greenhouse gases and ocean. In the all experiments, the Eurasian ice sheet is removed. The twelve experiments differ in the North American ice-sheet topography, ranging from a white and flat (present-day topography) ice sheet to a full-size LGM ice sheet. This experimental design allows to disentangle the albedo and the topographic impacts of the North American ice sheet onto the climate. The results are compared to our baseline experiment where both the North American and the Eurasian ice sheets have been removed. In summer, the sole albedo effect of the American ice sheet modifies the pattern of planetary waves with respect to the no-ice sheet case, causing a cooling of the Eurasian region. By contrast, the <span class="hlt">atmospheric</span> circulation changes induced by the topography of the North American ice sheet imply summer warming in Northwestern Eurasia. In winter, the Scandinavian and the Barents-Kara regions respond differently to the albedo effect: in response to <span class="hlt">atmospheric</span> circulation changes, Scandinavia warms up and precipitation is more abundant whereas Barents-Kara area cools down and gets drier. The height increase of the American ice sheet leads to less precipitation and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26969539','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26969539"><span id="translatedtitle">Kinetic and products study of the gas-phase reaction of Lewisite with ozone under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Haitao; Zhang, Yuanpeng; Guo, Xiaodi; Shao, Yusheng; Gao, Runli; Liang, Dejian; Sun, Hao</p> <p>2016-02-01</p> <p>The rate constant for the gas-phase reaction of O3 and Lewisite was studied in air using the smog chamber technique. The experiments were carried out under pseudo-first-order reaction <span class="hlt">conditions</span> with [O3]≪[Lewisite]. The observed rate constant of O3 with Lewisite was (7.83 ± 0.38) × 10(-19)cm(3)/(molecule·sec) at 298 ± 2K. Lewisite was discussed in terms of reactivity with O3 and its relationship with the ionization potential. Our results show that the rate constant for the gas-phase reaction of O3 with Lewisite is in line with the trend of the rate constants of O3 with haloalkenes. PMID:26969539</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1017331','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1017331"><span id="translatedtitle">Scientific uncertainties in <span class="hlt">atmospheric</span> mercury models III: Boundary and initial <span class="hlt">conditions</span>, model grid resolution, and Hg(II) reduction mechanism</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lin, Che-Jen; Pongprueksa, Pruek; Lindberg, Steven Eric; Jang, Carey; Braverman, Thomas; Bullock, Russell O; Ho, Thomas; Chu, Hsing-Wei</p> <p>2008-03-01</p> <p>In this study, the model response in terms of simulated mercury concentration and deposition to boundary <span class="hlt">condition</span> (BC), initial <span class="hlt">condition</span> (IC), model grid resolution (12 km versus 36 km), and two alternative Hg(II) reduction mechanisms, was investigated. The model response to the change of gaseous elemental mercury (GEM) concentration from 0 to 2 ngm3 in IC/BC is found to be very linear (r240.99) based on the results of sensitivity simulations in July 2001. An increase of 1 ngm3 of GEM in BC resulted in an increase of 0.81 ngm3 in the monthly average of total mercury concentration, and 1270 ngm2 in the monthly total deposition. IC has similar but weaker effects compared to those of BC. An increase of 1 ngm3 of GEM in IC resulted in an increase of 0.14 ngm3 in the monthly average of total mercury concentration, and 250 ngm2 in the monthly total deposition. Varying reactive gaseous mercury (RGM) or particulate mercury (PHg) in BC/IC has much less significant impact. Simulation results at different grid resolutions show good agreement (slope 0.950 1.026, r 0.816 0.973) in mercury concentration, dry deposition, and total deposition. The agreement in wet deposition is somewhat weaker (slope 0.770 0.794, r 0.685 0.892) due to the difference in emission dilution and simulated precipitation that subsequently change reaction rates in the aqueous phase. Replacing the aqueous Hg(II)-HO2 reduction by either RGM reduction by CO (51018cm3 molecule1 s1) or photoreduction of RGM (1105 s1) gives significantly better model agreement with the wet deposition measured by Mercury Deposition Network (MDN). Possible ranges of the reduction rates are estimated based on model sensitivity results. The kinetic estimate requires further verification by laboratory studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/993434','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/993434"><span id="translatedtitle">An Experimental Field Dataset with Buoyant, Neutral, and Dense Gas <span class="hlt">Atmospheric</span> Releases and Model Comparisons in Low-Wind Speed (Diffusion) <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Veronica E. Wannberg, Gustavious Williams, Patrick Sawyer, and Richard Venedam</p> <p>2010-09-01</p> <p>Aunique field dataset from a series of low–wind speed experiments, modeling efforts using three commonly used models to replicate these releases, and statistical analysis of how well these models were able to predict the plume concentrations is presented. The experiment was designed to generate a dataset to describe the behavior of gaseous plumes under low-wind <span class="hlt">conditions</span> and the ability of current, commonly used models to predict these movements. The dataset documents the release and transport of three gases: ammonia (buoyant), ethylene (neutral), and propylene (dense) in low–wind speed (diffusion) <span class="hlt">conditions</span>. Release rates ranged from 1 to 20 kg h21. Ammonia and ethylene had five 5-min releases each to represent puff releases and five 20-min releases each to represent plume releases. Propylene had five 5-min puffs, six 20-min plumes, and a single 30-min plume. Thirty-two separate releases ranging from 6 to 47 min were conducted, of which only 30 releases generated useful data. The data collected included release rates, <span class="hlt">atmospheric</span> concentrations to 100 m from the release point, and local meteorological <span class="hlt">conditions</span>. The diagnostics included nine meteorological stations on 100-m centers and 36 photoionization detectors in a radial pattern. Three current stateof- the-practice models, Aerial locations of Hazardous <span class="hlt">Atmospheres</span> (ALOHA), Emergency Prediction Information code (EPIcode), and Second-Order Closure Integrated Puff (SCIPUFF), were used to try to duplicate the measured field results. Low wind speeds are difficult to model, and all of the models had difficulty replicating the field measurements. However, the work does show that these models, if used correctly, are conservative (overpredict concentrations) and can be used for safety and emergency planning.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25930012','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25930012"><span id="translatedtitle">Polystyrene as a model system to probe the impact of ambient gas chemistry on polymer surface modifications using remote <span class="hlt">atmospheric</span> pressure plasma under well-controlled <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bartis, Elliot A J; Luan, Pingshan; Knoll, Andrew J; Hart, Connor; Seog, Joonil; Oehrlein, Gottlieb S</p> <p>2015-01-01</p> <p>An <span class="hlt">atmospheric</span> pressure plasma jet (APPJ) was used to treat polystyrene (PS) films under remote <span class="hlt">conditions</span> where neither the plume nor visible afterglow interacts with the film surface. Carefully controlled <span class="hlt">conditions</span> were achieved by mounting the APPJ inside a vacuum chamber interfaced to a UHV surface analysis system. PS was chosen as a model system as it contains neither oxygen nor nitrogen, has been extensively studied, and provides insight into how the aromatic structures widespread in biological systems are modified by <span class="hlt">atmospheric</span> plasma. These remote treatments cause negligible etching and surface roughening, which is promising for treatment of sensitive materials. The surface chemistry was measured by X-ray photoelectron spectroscopy to evaluate how ambient chemistry, feed gas chemistry, and plasma-ambient interaction impact the formation of specific moieties. A variety of oxidized carbon species and low concentrations of NOx species were measured after APPJ treatment. In the remote <span class="hlt">conditions</span> used in this work, modifications are not attributed to short-lived species, e.g., O atoms. It was found that O3 does not correlate with modifications, suggesting that other long-lived species such as singlet delta oxygen or NOx are important. Indeed, surface-bound NO3 was observed after treatment, which must originate from gas phase NOx as neither N nor O are found in the pristine film. By varying the ambient and feed gas chemistry to produce O-rich and O-poor <span class="hlt">conditions</span>, a possible correlation between the oxygen and nitrogen composition was established. When oxygen is present in the feed gas or ambient, high levels of oxidation with low concentrations of NO3 on the surface were observed. For O-poor <span class="hlt">conditions</span>, NO and NO2 were measured, suggesting that these species contribute to the oxidation process, but are easily oxidized when oxygen is present. That is, surface oxidation limits and competes with surface nitridation. Overall, surface oxidation takes place easily</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6903539','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6903539"><span id="translatedtitle"><span class="hlt">Adverse</span> possession of subsurface minerals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bowles, P.N.</p> <p>1983-01-01</p> <p>Concepts applicable to <span class="hlt">adverse</span> possession of subsurface minerals are generally the same as those that apply to <span class="hlt">adverse</span> possession of all real estate. However, special requirements must be satisfied in order to perfect title to subsurface minerals by <span class="hlt">adverse</span> possession, particularly when there has been a severance of the true title between surface and subsurface minerals. In those jurisdictions where senior and junior grants came from the state or commonwealth covering the same or some of the same land and in those areas where descriptions of land were vague or not carefully drawn, <span class="hlt">adverse</span> possession serves to solidify land and mineral ownership. There may be some public, social, and economic justification in rewarding, with good title, those who take possession and use real estate for its intended use, including the extraction of subsurface minerals. 96 refernces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.9469S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.9469S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Conditions</span> for the formation and <span class="hlt">atmospheric</span> dispersion of a toxic, heavy gas layer during thermal metamorphism of coal and evaporite deposits by sill intrusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Storey, Michael; Hankin, Robin K. S.</p> <p>2010-05-01</p> <p>There is compelling evidence for massive discharge of volatiles, including toxic species, into the <span class="hlt">atmosphere</span> at the end of the Permian. It has been argued that most of the gases were produced during thermal metamorphism of coal and evaporite deposits in the East Siberia Tunguska basin following sill intrusion (Retallack and Jahren, 2008; Svensen et al., 2009). The release of the volatiles has been proposed as a major cause of environmental and extinction events at the end of the Permian, with venting of carbon gases and halocarbons to the <span class="hlt">atmosphere</span> leading to global warming and <span class="hlt">atmospheric</span> ozone depletion (Svensen et al., 2009) Here we consider the <span class="hlt">conditions</span> required for the formation and dispersion of toxic, heavier than air, gas plumes, made up of a mixture of CO2, CH4, H2S and SO2 and formed during the thermal metamorphism of C- and S- rich sediments. Dispersion models and density considerations within a range of CO2/CH4 ratios and volatile fluxes and temperatures, for gas discharge by both seepage and from vents, allow the possibility that following sill emplacement much of the vast East Siberia Tunguska basin was - at least intermittently - covered by a heavy, toxic gas layer that was unfavorable for life. Dispersion scenarios for a heavy gas layer beyond the Siberian region during end-Permian times will be presented. REFERENCES G. J. Retallack and A. H. Jahren, Methane release from igneous intrusion of coal during Late Permian extinction events, Journal of Geology, volume 116, 1-20, 2008 H. Svensen et al., Siberian gas venting and the end-Permian environmental crisis, Earth and Planetary Science Letters, volume 277, 490-500, 2009</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940038994&hterms=Water+Africa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DWater%2BAfrica','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940038994&hterms=Water+Africa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DWater%2BAfrica"><span id="translatedtitle">Contrasting <span class="hlt">conditions</span> of surface water balance in wet years and dry years as a possible land surface-<span class="hlt">atmosphere</span> feedback mechanism in the West African Sahel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lare, A. R.; Nicholson, S. E.</p> <p>1994-01-01</p> <p>The climate of West Africa, in particular the Sahel, is characterized by multiyear persistence of anomalously wet or dry <span class="hlt">conditions</span>. Its Southern Hemisphere counterpart, the Kalahari, lacks the persistence that is evident in the Sahel even though both regions are subject to similar large-scale forcing. It has been suggested that land surface-<span class="hlt">atmosphere</span> feedback contributes to this persistence and to the severity of drought. In this study, surface energy and water balance are quantified for nine stations along a latitudinal transect that extends from the Sahara to the Guinea coast. In the wetter regions of West Africa, the difference between wet and dry years is primarily reflected in the magnitude of runoff. For the Sahel and drier locations, evapotranspiration and soil moisture are more sensitive to rainfall anomalies. The increase in evapotranspiration, and hence latent heating, over the Sahel in wet years alters the thermal structure and gradients of the overlying <span class="hlt">atmosphere</span> and thus the strength of the African easterly jet (AEJ) at 700 mb. The difference between dry and wet Augusts corresponds to a decrease in magnitude of the AEJ at 15 deg N on the order of 2.6 m/s, which is consistent with previous studies of observed winds. Spatial patterns were also developed for surface water balance parameters for both West Africa and southern Africa. Over southern Africa, the patterns are not as spatially homogeneous as those over West Africa and are lower in magnitude, thus supporting the suggestion that the persistence of rainfall anomalies in the Sahel might be due, at least in part, to land-<span class="hlt">atmosphere</span> feedback, and that the absence of such persistence in the Kalahari is a consequence of less significant changes in surface water and energy balance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1024198','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1024198"><span id="translatedtitle">ASSESSMENT OF 90SR AND 137CS PENETRATION INTO REINFORCED CONCRETE (EXTENT OF 'DEEPENING') UNDER NATURAL <span class="hlt">ATMOSPHERIC</span> <span class="hlt">CONDITIONS</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Farfan, E.; Jannik, T.</p> <p>2011-10-01</p> <p>When assessing the feasibility of remediation following the detonation of a radiological dispersion device or improvised nuclear device in a large city, several issues should be considered including the levels and characteristics of the radioactive contamination, the availability of resources required for decontamination, and the planned future use of the city's structures and buildings. Currently, little is known about radionuclide penetration into construction materials in an urban environment. Knowledge in this area would be useful when considering costs of a thorough decontamination of buildings, artificial structures, and roads in an affected urban environment. Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident in April 1986, may provide some answers. The main objective of this study was to assess the depth of {sup 90}Sr and {sup 137}Cs penetration into reinforced concrete structures in a highly contaminated urban environment under natural weather <span class="hlt">conditions</span>. Thirteen reinforced concrete core samples were obtained from external surfaces of a contaminated building in Pripyat. The concrete cores were drilled to obtain sample layers of 0-5, 5-10, 10-15, 15-20, 20-30, 30-40, and 40-50 mm. Both {sup 90}Sr and {sup 137}Cs were detected in the entire 0-50 mm profile of the reinforced cores sampled. In most of the cores, over 90% of the total {sup 137}Cs inventory and 70% of the total {sup 90}Sr inventory was found in the first 0-5 mm layer of the reinforced concrete. {sup 90}Sr had penetrated markedly deeper into the reinforced concrete structures than {sup 137}Cs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21799347','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21799347"><span id="translatedtitle">Assessment of (90)sr and (137)cs penetration into reinforced concrete (extent of "deepening") under natural <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Farfán, Eduardo B; Gaschak, Sergey P; Maksymenko, Andrey M; Donnelly, Elizabeth H; Bondarkov, Mikhail D; Jannik, G Tim; Marra, James C</p> <p>2011-09-01</p> <p>When assessing the feasibility of remediation following the detonation of a radiological dispersion device or improvised nuclear device in a large city, several issues should be considered, including the levels and characteristics of the radioactive contamination, the availability of resources required for decontamination and the planned future use of the city's structures and buildings. Currently, little is known about radionuclide penetration into construction materials in an urban environment. Knowledge in this area would be useful when considering costs of a thorough decontamination of buildings, artificial structures and roads in an affected urban environment. Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident in April 1986, may provide some answers. The main objective of this study was to assess the depth of (90)Sr and (137)Cs penetration into reinforced concrete structures in a highly contaminated urban environment under natural weather <span class="hlt">conditions</span>. Thirteen reinforced concrete core samples were obtained from external surfaces of a contaminated building in Pripyat. The concrete cores were drilled to obtain sample layers of 0-5, 5-10, 10-15, 15-20, 20-30, 30-40 and 40-50 mm. Both (90)Sr and (137)Cs were detected in the entire 0-50 mm profile of the reinforced cores sampled. In most of the cores, over 90% of the total (137)Cs inventory and 70% of the total (90)Sr inventory was found in the first 0-5 mm layer of the reinforced concrete. Strontium-90 ((90)Sr) had penetrated markedly deeper into the reinforced concrete structures than (137)Cs. PMID:21799347</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014JPS...259..245H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014JPS...259..245H&link_type=ABSTRACT"><span id="translatedtitle">Role of process <span class="hlt">conditions</span> on the microstructure, stoichiometry and functional performance of <span class="hlt">atmospheric</span> plasma sprayed La(Sr)MnO3 coatings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Su Jung; Chen, Yikai; Sampath, Sanjay</p> <p>2014-08-01</p> <p>Strontium doped lanthanum manganite (LSM) perovskite coatings were produced via <span class="hlt">atmospheric</span> plasma spray technique to examine their applicability as electrically conductive coatings to protect chromium-poisoning of cathode side metallic interconnects in solid oxide fuel cells. Various plasma spray process <span class="hlt">conditions</span> were manipulated including plasma power, total gas flow and content of H2 in the plasma gas in order to understand their effects on coating properties as well as efficacy as a protectant against Cr-poisoning. In-flight temperatures and velocities of spray particles were monitored for the various plasma spray <span class="hlt">conditions</span> enabling assessment of thermal and kinetic energies of LSM particles. As anticipated, coating density improves with increasing thermal and/or kinetic energies of the LSM particles. However, the LSM particles also experienced significant phase decomposition at higher thermal exposure and longer residence time <span class="hlt">conditions</span>. Due to preferential loss of oxygen and manganese, La2O3 phase is also formed under certain processing regimes. The resultant mixed-phase coating is ineffective both from electrical transport and as a protective coating for the metallic interconnect. Concomitantly, coatings with limited decomposition show excellent conductivity and protection characteristics demonstrating the need for mechanism driven process optimization for these functional oxide coatings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JASMS..26.1252G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JASMS..26.1252G"><span id="translatedtitle">Regulated In Situ Generation of Molecular Ions or Protonated Molecules under <span class="hlt">Atmospheric</span>-Pressure Helium-Plasma-Ionization Mass Spectrometric <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gangam, Rekha; Pavlov, Julius; Attygalle, Athula B.</p> <p>2015-07-01</p> <p>In an enclosed <span class="hlt">atmospheric</span>-pressure helium-plasma ionization (HePI) source engulfed with dehumidified ambient gases, molecular cations are generated from compounds such as toluene, bromobenzene, and iodobenzene. Evidently, the ionization is effected by a direct Penning mechanism attributable to interactions of the gas-phase analyte with metastable helium atoms. It is widely known that secondary ions generated from ambient gases also play an important role in the overall ionization process. For example, when the ambient gases bear even traces of moisture, the analytes are ionized by proton transfer reactions with gaseous H3O+. In this study, we demonstrate how a controlled variation of experimental <span class="hlt">conditions</span> can manipulate the abundance of molecular ions and protonated molecules in a HePI source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998JCrGr.189..519T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998JCrGr.189..519T&link_type=ABSTRACT"><span id="translatedtitle">Growth <span class="hlt">condition</span> dependence of Mg-doped GaN film grown by horizontal <span class="hlt">atmospheric</span> MOCVD system with three layered laminar flow gas injection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tokunaga, H.; Waki, I.; Yamaguchi, A.; Akutsu, N.; Matsumoto, K.</p> <p>1998-06-01</p> <p>We developed a novel <span class="hlt">atmospheric</span> pressure horizontal MOCVD system (SR2000) for the growth of III-nitride film. This system was designed for high-speed gas flow in order to suppress thermal convection and undesirable reactant gas reaction. We have grown Mg-doped GaN films using SR2000. We studied the bis-cyclopentadienyl magnesium (Cp 2Mg) flow rate dependence and growth temperature ( Tg) dependence of Mg-doped GaN. As a result, we have obtained p-type GaN film with hole carrier density of 8×10 17 cm -3 with a mobility of 7.5 cm 2/(V s) at the growth <span class="hlt">condition</span> with Cp 2Mg flow rate of 0.1 μmol/min at Tg of 1025°C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1178046','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1178046"><span id="translatedtitle">An experimental study on sub-cooled flow boiling CHF of R134a at low pressure <span class="hlt">condition</span> with <span class="hlt">atmospheric</span> pressure (AP) plasma assisted surface modification</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Seung Jun; Zou, Ling; Jones, Barclay G.</p> <p>2015-02-01</p> <p>In this study, sub-cooled flow boiling critical heat flux tests at low pressure were conducted in a rectangular flow channel with one uniformly heated surface, using simulant fluid R-134a as coolant. The experiments were conducted under the following <span class="hlt">conditions</span>: (1) inlet pressure (P) of 400-800 kPa, (2) mass flux (G) of 124-248 kg/m<sup>2</sup>s, (3) inlet sub-cooling enthalpy (ΔH<sub>i</sub>) of 12~ 26 kJ/kg. Parametric trends of macroscopic system parameters (G, P, H<sub>i</sub>) were examined by changing inlet <span class="hlt">conditions</span>. Those trends were found to be generally consistent with previous understandings of CHF behavior at low pressure <span class="hlt">condition</span> (i.e. reduced pressure less than 0.2). A fluid-to-fluid scaling model was utilized to convert the test data obtained with the simulant fluid (R-134a) into the prototypical fluid (water). The comparison between the converted CHF of equivalent water and CHF look-up table with same operation <span class="hlt">conditions</span> were conducted, which showed good agreement. Furthermore, the effect of surface wettability on CHF was also investigated by applying <span class="hlt">atmospheric</span> pressure plasma (AP-Plasma) treatment to modify the surface characteristic. With AP-Plasma treatment, the change of microscopic surface characteristic was measured in terms of static contact angle. The static contact angle was reduced from 80° on original non-treated surface to 15° on treated surface. An enhancement of 18% on CHF values under flow boiling <span class="hlt">conditions</span> were observed on AP-Plasma treated surfaces compared to those on non-treated heating surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26072883','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26072883"><span id="translatedtitle"><span class="hlt">Atmospheric</span> CO(2) column measurements in cloudy <span class="hlt">conditions</span> using intensity-modulated continuous-wave lidar at 1.57 micron.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Bing; Nehrir, Amin R; Harrison, F Wallace; Browell, Edward V; Ismail, Syed; Obland, Michael D; Campbell, Joel; Dobler, Jeremy; Meadows, Byron; Fan, Tai-Fang; Kooi, Susan</p> <p>2015-06-01</p> <p>This study evaluates the capability of <span class="hlt">atmospheric</span> CO<sub>2</sub> column measurements under cloudy <span class="hlt">conditions</span> using an airborne intensity-modulated continuous-wave integrated-path-differential-absorption lidar operating in the 1.57-μm CO<sub>2</sub> absorption band. The <span class="hlt">atmospheric</span> CO<sub>2</sub> column amounts from the aircraft to the tops of optically thick cumulus clouds and to the surface in the presence of optically thin clouds are retrieved from lidar data obtained during the summer 2011 and spring 2013 flight campaigns, respectively. For the case of intervening thin cirrus clouds with an average cloud optical depth of about 0.16 over an arid/semi-arid area, the CO<sub>2</sub> column measurements from 12.2 km altitude were found to be consistent with the cloud free <span class="hlt">conditions</span> with a lower precision due to the additional optical attenuation of the thin clouds. The clear sky precision for this flight campaign case was about 0.72% for a 0.1-s integration, which was close to previously reported flight campaign results. For a vegetated area and lidar path lengths of 8 to 12 km, the precision of the measured differential absorption optical depths to the surface was 1.3 - 2.2% for 0.1-s integration. The precision of the CO<sub>2</sub> column measurements to thick clouds with reflectance about 1/10 of that of the surface was about a factor of 2 to 3 lower than that to the surface owing to weaker lidar returns from clouds and a smaller CO<sub>2</sub> differential absorption optical depth compared to that for the entire column. PMID:26072883</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25732020','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25732020"><span id="translatedtitle"><span class="hlt">Adverse</span> environments and children's creativity development: transforming the notion of "success in <span class="hlt">adversity</span>" in China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Li; Tan, Mei; Liu, Zhengkui</p> <p>2015-01-01</p> <p>China has been undergoing great social change due to its new focus on urbanization and globalization. Such change has had a tremendous <span class="hlt">adverse</span> impact on the living <span class="hlt">conditions</span> of millions of young children, simultaneously generating new interest in children's creativity development. The intersection of these two issues has important implications for China's future as it brings together one of China's core cultural values-"success in <span class="hlt">adversity</span>"-the importance of creativity, and very real social and economic needs. "Success in <span class="hlt">adversity</span>" reflects the strongly held belief that individuals who suffer <span class="hlt">adverse</span> environments can rise to excellence and success through persistence, effort, and creativity. In this article, we briefly explore the historical sources of this belief and how it is closely related to the Chinese conception of creativity. We then present some studies on the creativity of some of China's migrant children. Findings show that while migrant children as a group may not generally exhibit higher creativity than their urban peers as hypothesized, indications of resilience and creative potential suggest that the notion of success in <span class="hlt">adversity</span> may contribute to the positive development of China's migrant children more substantially when it is informed by research and augmented by research-supported policy. PMID:25732020</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26147909','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26147909"><span id="translatedtitle">Biologics in dermatology: <span class="hlt">adverse</span> effects.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sehgal, Virendra N; Pandhi, Deepika; Khurana, Ananta</p> <p>2015-12-01</p> <p>Biologics are a group of drugs that precisely affect certain specific steps in the immune response and are an extremely useful group when used in an appropriate setting. However, their use can often be a double-edged sword. Careful patient selection and thorough knowledge of <span class="hlt">adverse</span> effects is a key to their successful use in various disorders. The initial enthusiasm has gradually given way to a more cautious approach wherein a balance is sought between clinical usefulness and expected side effects. The <span class="hlt">adverse</span> effects of the biologics most commonly used in dermatology have been carefully listed for ready reference. The plausible causes of the <span class="hlt">adverse</span> reactions are succinctly outlined along with their incriminating factor(s). Besides, in brief, the attention has been focused on their management. The content should provide an essential didactic content for educating the practitioner. PMID:26147909</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4905O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4905O"><span id="translatedtitle">Warm water events in the southeast Atlantic and their impact on regional and large-scale <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> in the CMIP5 model output</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ott, Irena; Lutz, Karin; Rathmann, Joachim; Jacobeit, Jucundus</p> <p>2013-04-01</p> <p>Two types of El Niño-like events are described in the South Atlantic: the Atlantic Niño in the equatorial Atlantic and the Benguela Niño off the Namibian and Angolan coast. These warm water events are known to be associated with rainfall anomalies at the West and Southwest African coastal region and harm marine ecosystems and fish populations. The two phenomena are handled separately so far, but the identification of warm water events in our study - via similar variabilities of sea surface temperatures (SST) - based on observed SST data (HadISST1.1) as well as global climate model output from CMIP5, involved the definition of an area mean index that includes both Niño types from the Atlantic region. A multi-model ensemble of the CMIP5 output is used to investigate the impact of Atlantic Niño events on regional <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>. Based on the Atlantic SST index, composite analyses give information about anomalous precipitation, air pressure, humidity, evaporation, horizontal wind and vertical air motion patterns over the African continent and the South Atlantic. The Atlantic variability mode is similar to the Pacific El Niño system, but more irregular and less intense. However, recent studies show that the Atlantic influences the El Niño Southern Oscillation (ENSO) in the Pacific Ocean by the modification of the Walker and Hadley circulations and associated wind stress, thermocline and SST anomalies, further amplified by the Bjerknes positive feedback. As a result, an Atlantic Niño is followed by a La Niña-like phenomenon in the Pacific area with a lag of six months. In our study, the CMIP5 output is considered with respect to its ability of describing the complex connection between the Atlantic and Pacific variability modes. For that purpose, the inter-ocean teleconnection is studied with correlation analyses of the ensemble members of the CMIP5 output by means of the Atlantic index, the Southern Oscillation (SOI) and the Pacific El Niño indices (Ni</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150018555','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150018555"><span id="translatedtitle"><span class="hlt">Atmospheric</span> Photochemistry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Massey, Harrie; Potter, A. E.</p> <p>1961-01-01</p> <p>The upper <span class="hlt">atmosphere</span> offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper <span class="hlt">atmosphere</span> as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure <span class="hlt">conditions</span> in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper <span class="hlt">atmosphere</span>. Some of them are luminescent, causing the <span class="hlt">atmosphere</span> to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary <span class="hlt">atmospheres</span>, and they might be predicted if sufficient chemical information were available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24011493','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24011493"><span id="translatedtitle"><span class="hlt">Adverse</span> childhood experiences and health anxiety in adulthood.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reiser, Sarah J; McMillan, Katherine A; Wright, Kristi D; Asmundson, Gordon J G</p> <p>2014-03-01</p> <p>Childhood experiences are thought to predispose a person to the development of health anxiety later in life. However, there is a lack of research investigating the influence of specific <span class="hlt">adverse</span> experiences (e.g., childhood abuse, household dysfunction) on this <span class="hlt">condition</span>. The current study examined the cumulative influence of multiple types of childhood <span class="hlt">adversities</span> on health anxiety in adulthood. Adults 18-59 years of age (N=264) completed a battery of measures to assess <span class="hlt">adverse</span> childhood experiences, health anxiety, and associated constructs (i.e., negative affect and trait anxiety). Significant associations were observed between <span class="hlt">adverse</span> childhood experiences, health anxiety, and associated constructs. Hierarchical multiple regression analysis indicted that <span class="hlt">adverse</span> childhood experiences were predictive of health anxiety in adulthood; however, the unique contribution of these experience were no longer significant following the inclusion of the other variables of interest. Subsequently, mediation analyses indicated that both negative affect and trait anxiety independently mediated the relationship between <span class="hlt">adverse</span> childhood experiences and health anxiety in adulthood. Increased exposure to <span class="hlt">adverse</span> childhood experiences is associated with higher levels of health anxiety in adulthood; this relationship is mediated through negative affect and trait anxiety. Findings support the long-term negative impact of cumulative <span class="hlt">adverse</span> childhood experiences and emphasize the importance of addressing negative affect and trait anxiety in efforts to prevent and treat health anxiety. PMID:24011493</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26159709','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26159709"><span id="translatedtitle">Kinetics of the unimolecular reaction of CH2OO and the bimolecular reactions with the water monomer, acetaldehyde and acetone under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berndt, Torsten; Kaethner, Ralf; Voigtländer, Jens; Stratmann, Frank; Pfeifle, Mark; Reichle, Patrick; Sipilä, Mikko; Kulmala, Markku; Olzmann, Matthias</p> <p>2015-08-14</p> <p>Stabilized Criegee Intermediates (sCIs) have been identified as oxidants of <span class="hlt">atmospheric</span> trace gases such as SO2, NO2, carboxylic acids or carbonyls. The <span class="hlt">atmospheric</span> sCI concentrations, and accordingly their importance for trace gas oxidation, are controlled by the rate of the most important loss processes, very likely the unimolecular reactions and the reaction with water vapour (monomer and dimer) ubiquitously present at high concentrations in the troposphere. In this study, the rate coefficients of the unimolecular reaction of the simplest sCI, formaldehyde oxide, CH2OO, and its bimolecular reaction with the water monomer have been experimentally determined at T = (297 ± 1) K and at <span class="hlt">atmospheric</span> pressure by using a free-jet flow system. CH2OO was produced by the reaction of ozone with C2H4, and CH2OO concentrations were probed indirectly by detecting H2SO4 after titration with SO2. Time-resolved experiments yield a rate coefficient of the unimolecular reaction of k(uni) = (0.19 ± 0.07) s(-1), a value that is supported by quantum-chemical and statistical rate theory calculations as well as by additional measurements performed under CH2OO steady-state <span class="hlt">conditions</span>. A rate coefficient of k(CH2OO+H2O) = (3.2 ± 1.2) × 10(-16) cm(3) molecule(-1) s(-1) has been determined for sufficiently low H2O concentrations (<10(15) molecule cm(-3)) that allow separation from the CH2OO reaction with the water dimer. In order to evaluate the accuracy of the experimental approach, the rate coefficients of the reactions with acetaldehyde and acetone were reinvestigated. The obtained rate coefficients k(CH2OO+acetald) = (1.7 ± 0.5) × 10(-12) and k(CH2OO+acetone) = (3.4 ± 0.9) × 10(-13) cm(3) molecule(-1) s(-1) are in good agreement with literature data. PMID:26159709</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1055294','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1055294"><span id="translatedtitle">Understanding <span class="hlt">adverse</span> events: human factors.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reason, J</p> <p>1995-01-01</p> <p>(1) Human rather than technical failures now represent the greatest threat to complex and potentially hazardous systems. This includes healthcare systems. (2) Managing the human risks will never be 100% effective. Human fallibility can be moderated, but it cannot be eliminated. (3) Different error types have different underlying mechanisms, occur in different parts of the organisation, and require different methods of risk management. The basic distinctions are between: Slips, lapses, trips, and fumbles (execution failures) and mistakes (planning or problem solving failures). Mistakes are divided into rule based mistakes and knowledge based mistakes. Errors (information-handling problems) and violations (motivational problems) Active versus latent failures. Active failures are committed by those in direct contact with the patient, latent failures arise in organisational and managerial spheres and their <span class="hlt">adverse</span> effects may take a long time to become evident. (4) Safety significant errors occur at all levels of the system, not just at the sharp end. Decisions made in the upper echelons of the organisation create the <span class="hlt">conditions</span> in the workplace that subsequently promote individual errors and violations. Latent failures are present long before an accident and are hence prime candidates for principled risk management. (5) Measures that involve sanctions and exhortations (that is, moralistic measures directed to those at the sharp end) have only very limited effectiveness, especially so in the case of highly trained professionals. (6) Human factors problems are a product of a chain of causes in which the individual psychological factors (that is, momentary inattention, forgetting, etc) are the last and least manageable links. Attentional "capture" (preoccupation or distraction) is a necessary <span class="hlt">condition</span> for the commission of slips and lapses. Yet, its occurrence is almost impossible to predict or control effectively. The same is true of the factors associated with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18378823','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18378823"><span id="translatedtitle"><span class="hlt">Adversity</span> and advancing nursing knowledge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reed, Pamela G</p> <p>2008-04-01</p> <p>This column reports the theme of <span class="hlt">adversity</span> addressed in reference to theoretical and metatheoretical considerations for advancing nursing knowledge. The development and content of three classic nursing theories are presented by Neuman representatives, and by theorists King and Roy. Topics for continued dialogue are identified as derived from the interface between philosophy of science issues and these theories. PMID:18378823</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=childhood+AND+experiences&pg=4&id=EJ698268','ERIC'); return false;" href="http://eric.ed.gov/?q=childhood+AND+experiences&pg=4&id=EJ698268"><span id="translatedtitle"><span class="hlt">Adverse</span> Childhood Experiences and Hallucinations</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Whitfield, C.L.; Dube, S.R.; Felitti, V.J.; Anda, R.F.</p> <p>2005-01-01</p> <p>Objective:: Little information is available about the contribution of multiple <span class="hlt">adverse</span> childhood experiences (ACEs) to the likelihood of reporting hallucinations. We used data from the ACE study to assess this relationship. Methods:: We conducted a survey about childhood abuse and household dysfunction while growing up, with questions about health…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2417514','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2417514"><span id="translatedtitle"><span class="hlt">Adverse</span> ocular reactions to drugs.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Spiteri, M. A.; James, D. G.</p> <p>1983-01-01</p> <p>Drugs acting on various parts of the body may also affect the eye insidiously. Increased awareness of such drug toxicity by the prescribing doctor should encourage him to consider effects on the cornea, lens, retina, optic nerve and elsewhere when checking the patient's progress. The following review concerns <span class="hlt">adverse</span> ocular effects of systemic drug administration. PMID:6356101</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799240','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799240"><span id="translatedtitle">Urbanicity, social <span class="hlt">adversity</span> and psychosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Heinz, Andreas; Deserno, Lorenz; Reininghaus, Ulrich</p> <p>2013-01-01</p> <p>In recent years, there has been increasing interest in research on geographical variation in the incidence of schizophrenia and other psychoses. In this paper, we review the evidence on variation in incidence of schizophrenia and other psychoses in terms of place, as well as the individual- and area-level factors that account for this variation. We further review findings on potential mechanisms that link <span class="hlt">adverse</span> urban environment and psychosis. There is evidence from earlier and more recent studies that urbanicity is associated with an increased incidence of schizophrenia and non-affective psychosis. In addition, considerable variation in incidence across neighbourhoods has been observed for these disorders. Findings suggest it is unlikely that social drift alone can fully account for geographical variation in incidence. Evidence further suggests that the impact of <span class="hlt">adverse</span> social contexts – indexed by area-level exposures such as population density, social fragmentation and deprivation – on risk of psychosis is explained (confounding) or modified (interaction) by environmental exposures at the individual level (i.e., cannabis use, social <span class="hlt">adversity</span>, exclusion and discrimination). On a neurobiological level, several studies suggest a close link between social <span class="hlt">adversity</span>, isolation and stress on the one hand, and monoamine dysfunction on the other, which resembles findings in schizophrenia patients. However, studies directly assessing correlations between urban stress or discrimination and neurobiological alterations in schizophrenia are lacking to date. PMID:24096775</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015GPC...133..309Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015GPC...133..309Z&link_type=ABSTRACT"><span id="translatedtitle">Analysis of dry/wet <span class="hlt">conditions</span> in the Gan River Basin, China, and their association with large-scale <span class="hlt">atmospheric</span> circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yuqing; You, Qinglong; Lin, Houbo; Chen, Changchun</p> <p>2015-10-01</p> <p>Droughts and floods are natural phenomena that occur when water availability is significantly below or above normal levels over a specific period. In recent years, the Gan River Basin has frequently been threatened by droughts and floods, and it is important to evaluate the characteristics of dry/wet <span class="hlt">conditions</span> for better water resource management and disaster mitigation in this region. On the basis of precipitation and temperature data for the period 1964-2013 from 40 meteorological stations across the basin, the variability of dry/wet <span class="hlt">conditions</span> was analyzed using the standardized precipitation evapotranspiration index (SPEI). In addition, the standardized streamflow index (SSI) and large-scale <span class="hlt">atmospheric</span> circulation patterns calculated from NCEP/NCAR reanalysis data were used to further explore and evaluate temporal variations, spatial patterns, and possible mechanism responsible for the formation of dry/wet <span class="hlt">conditions</span> in the basin. The results indicated that robust coefficients between monthly SSI and SPEI exist at multiple timescales. The best correlation coefficients were found at timescales of 2-3 months, which better reflect the intensity and magnitude of seasonal dry/wet <span class="hlt">conditions</span>. Application of a 3-month SPEI for the dry (July-September) and wet (April-June) seasons indicated that severe dry/wet episodes were easy to occur in the northern part of the basin. The difference between composites of anomalous dry/wet seasons shows that both a positive height anomaly at 500 hPa and a very little water vapor flux influence the basin during the dry season of anomalous years, which can lead to the occurrence of drought events in the basin. However, during the wet season of anomalous years, geopotential height anomalies caused by areas of high pressure in the south (South China Sea) and areas of low pressure in the north (Mongolia), are responsible for the transport of copious amounts of water vapor from both the Bay of Bengal and the South China Sea. Under these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.6375K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.6375K&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Atmospheric</span> <span class="hlt">conditions</span> and transport patterns associated with high and low summer ozone levels in the lower troposphere and the boundary layer over the eastern Mediterranean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kalabokas, Pavlos; Cammas, Jean-Pierre; Thouret, Valerie; Volz-Thomas, Andreas; Boulanger, Damien; Repapis, Christos</p> <p>2016-04-01</p> <p> layer, there are extended regions of strong subsidence in the eastern Mediterranean but also in eastern and northern Europe and over these regions the <span class="hlt">atmosphere</span> is dryer than average. The results of this study will be used within the framework of the MACC project. References Kalabokas, P. D., Cammas, J.-P., Thouret, V., Volz-Thomas, A., Boulanger, D. and Repapis C.C. 2013. Examination of the <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> associated with high and low summer ozone levels in the lower troposphere over the eastern Mediterranean. Atmos. Chem. Phys. 13, 10339-10352. DOI: http://dx.doi.org/10.5194/acp-13-10339-2013 Kalabokas P. D., Thouret V., Cammas J.-P., Volz-thomas A., Boulanger D., Repapis C.C., 2015. The geographical distribution of meteorological parameters associated with high and low summer ozone levels in the lower troposphere and the boundary layer over the eastern Mediterranean (Cairo case), Tellus B, 67, 27853, http://dx.doi.org/10.3402/tellusb.v67.27853.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27470485','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27470485"><span id="translatedtitle">Synthesis and application of hexagonal perovskite BaNiO3 with quadrivalent nickel under <span class="hlt">atmospheric</span> and low-temperature <span class="hlt">conditions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Jin Goo; Hwang, Ho Jung; Kwon, Ohchan; Jeon, Ok Sung; Jang, Jeongseok; Shul, Yong-Gun</p> <p>2016-09-14</p> <p>A hexagonal perovskite BaNiO3 with unusually high-valence nickel(iv) was synthesized under <span class="hlt">atmospheric</span> and low-temperature <span class="hlt">conditions</span> by an ethylenediamine-derived wet-chemical route. Secondary phases disappeared with increase in the pH value, and the single-phase BaNiO3 was successfully synthesized at pH 10. The specific surface area was ∼32 m(2) g(-1), which is significantly enhanced compared to the BaNiO3 (0.3 m(2) g(-1)) synthesized by flux-mediated crystal growth. The BaNiO3 was used as an oxygen-evolution reaction (OER) catalyst, and the specific mass activity was ∼5 times higher than that of the BaNiO3 synthesized by flux-mediated crystal growth. As a result, the ethylenediamine-derived sol-gel synthesis could be a simple technique to prepare crystalline compounds such as perovskites and spinels, with unusually high-valence transition metals. PMID:27470485</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3093800','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3093800"><span id="translatedtitle">A review of low-level air pollution and <span class="hlt">adverse</span> effects on human health: implications for epidemiological studies and public policy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Olmo, Neide Regina Simões; do Nascimento Saldiva, Paulo Hilário; Braga, Alfésio Luís Ferreira; Lin, Chin An; de Paula Santos, Ubiratan; Pereira, Luiz Alberto Amador</p> <p>2011-01-01</p> <p>The aim of this study was to review original scientific articles describing the relationship between <span class="hlt">atmospheric</span> pollution and damage to human health. We also aimed to determine which of these studies mentioned public policy issues. Original articles relating to <span class="hlt">atmospheric</span> pollution and human health published between 1995 and 2009 were retrieved from the PubMed database and analyzed. This study included only articles dealing with <span class="hlt">atmospheric</span> pollutants resulting primarily from vehicle emissions. Three researchers were involved in the final selection of the studies, and the chosen articles were approved by at least two of the three researchers. Of the 84 non-Brazilian studies analyzed, 80 showed an association between <span class="hlt">atmospheric</span> pollution and <span class="hlt">adverse</span> effects on human health. Moreover, 66 showed evidence of <span class="hlt">adverse</span> effects on human health, even at levels below the permitted emission standards. Three studies mentioned public policies aimed at changing emission standards. Similarly, the 29 selected Brazilian studies reported <span class="hlt">adverse</span> associations with human health, and 27 showed evidence of <span class="hlt">adverse</span> effects even at levels below the legally permitted emission standards. Of these studies, 16 mentioned public policies aimed at changing emission standards. Based on the Brazilian and non-Brazilian scientific studies that have been conducted, it can be concluded that, even under <span class="hlt">conditions</span> that are compliant with Brazilian air quality standards, the concentration of <span class="hlt">atmospheric</span> pollutants in Brazil can negatively affect human health. However, as little discussion of this topic has been generated, this finding demonstrates the need to incorporate epidemiological evidence into decisions regarding legal regulations and to discuss the public policy implications in epidemiological studies. PMID:21655765</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA10097&hterms=sounds+wave&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsounds%2Bwave','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA10097&hterms=sounds+wave&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsounds%2Bwave"><span id="translatedtitle"><span class="hlt">Atmospheric</span> Waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p><p/> With its Multispectral Visible Imaging Camera (MVIC), half of the Ralph instrument, New Horizons captured several pictures of mesoscale gravity waves in Jupiter's equatorial <span class="hlt">atmosphere</span>. Buoyancy waves of this type are seen frequently on Earth - for example, they can be caused when air flows over a mountain and a regular cloud pattern forms downstream. In Jupiter's case there are no mountains, but if <span class="hlt">conditions</span> in the <span class="hlt">atmosphere</span> are just right, it is possible to form long trains of these small waves. The source of the wave excitation seems to lie deep in Jupiter's <span class="hlt">atmosphere</span>, below the visible cloud layers at depths corresponding to pressures 10 times that at Earth's surface. The New Horizons measurements showed that the waves move about 100 meters per second faster than surrounding clouds; this is about 25% of the speed of sound on Earth and is much greater than current models of these waves predict. Scientists can 'read' the speed and patterns these waves to learn more about activity and stability in the <span class="hlt">atmospheric</span> layers below.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26645393','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26645393"><span id="translatedtitle">Cardiovascular <span class="hlt">adverse</span> effects of phenytoin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guldiken, B; Rémi, J; Noachtar, Soheyl</p> <p>2016-05-01</p> <p>Phenytoin is an established drug in the treatment of acute repetitive seizures and status epilepticus. One of its main advantages over benzodiazepines is the less sedative effect. However, the possibility of cardiovascular <span class="hlt">adverse</span> effects with the intravenous use of phenytoin cause a reluctance to its usage, and this has lead to a search for safer anticonvulsant drugs. In this study, we aimed to review the studies which evaluated the safety of phenytoin with respect to cardiovascular <span class="hlt">adverse</span> effects. The original clinical trials and case reports listed in PUBMED in English language between the years of 1946-2014 were evaluated. As the key words, "phenytoin, diphenylhydantoin, epilepsy, seizure, cardiac toxicity, asystole, arrhythmia, respiratory arrest, hypotension, death" were used. Thirty-two clinical trials and ten case reports were identified. In the case reports, a rapid infusion rate (>50 mg/min) of phenytoin appeared as the major cause of increased mortality. In contrast, no serious cardiovascular <span class="hlt">adverse</span> effects leading to death were met in the clinical trials which applied the recommended infusion rate and dosages. An infusion rate of 50 mg/min was reported to be safe for young patients. For old patients and patients with a cardiovascular co-morbidity, a slower infusion rate was recommended with a careful follow-up of heart rhythm and blood pressure. No cardiovascular <span class="hlt">adverse</span> effect was reported in oral phenytoin overdoses except one case with a very high serum phenytoin level and hypoalbuminemia. Phenytoin is an effective and well tolerated drug in the treatment of epilepsy. Intravenous phenytoin is safe when given at recommended infusion rates and doses. PMID:26645393</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24864567','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24864567"><span id="translatedtitle">[<span class="hlt">Adverse</span> events of psychotropic drugs].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Watanabe, Koichiro; Kikuchi, Toshiaki</p> <p>2014-01-01</p> <p>The authors discuss <span class="hlt">adverse</span> events which are often missed but clinicians should pay attention to in order to preserve patients'quality of life(QOL). Among mood stabilizers, lithium may cause a urinary volume increase, hyperparathyroidism, and serum calcium elevation; sodium valproate possibly increases androgenic hormone levels and the risk of polycystic ovary syndrome (PCOS) as well as hypothyroidism. Moreover, in addition to teratogenesis, it has been reported that fetal exposure to a higher dose of valproate is associated with a lower intelligence quotient and higher incidence of autism spectrum disorders in children. Antidepressants with a higher affinity for serotonin transporters might induce gastrointestinal bleeding, and some antidepressants cause sexual dysfunction more frequently than others. Activation syndrome is still a key side effect which should be noted. Regarding the <span class="hlt">adverse</span> events of antipsychotics, subjective side effects unpleasant to patients such as dysphoria and a lower subjective well-being should not be overlooked. We clinicians have to cope with <span class="hlt">adverse</span> events worsening the QOL of patients with psychiatric disorders and, therefore, we need to adopt appropriate counter-measures. PMID:24864567</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=150365','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=150365"><span id="translatedtitle">Detecting <span class="hlt">Adverse</span> Events Using Information Technology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bates, David W.; Evans, R. Scott; Murff, Harvey; Stetson, Peter D.; Pizziferri, Lisa; Hripcsak, George</p> <p>2003-01-01</p> <p>Context: Although patient safety is a major problem, most health care organizations rely on spontaneous reporting, which detects only a small minority of <span class="hlt">adverse</span> events. As a result, problems with safety have remained hidden. Chart review can detect <span class="hlt">adverse</span> events in research settings, but it is too expensive for routine use. Information technology techniques can detect some <span class="hlt">adverse</span> events in a timely and cost-effective way, in some cases early enough to prevent patient harm. Objective: To review methodologies of detecting <span class="hlt">adverse</span> events using information technology, reports of studies that used these techniques to detect <span class="hlt">adverse</span> events, and study results for specific types of <span class="hlt">adverse</span> events. Design: Structured review. Methodology: English-language studies that reported using information technology to detect <span class="hlt">adverse</span> events were identified using standard techniques. Only studies that contained original data were included. Main Outcome Measures: <span class="hlt">Adverse</span> events, with specific focus on nosocomial infections, <span class="hlt">adverse</span> drug events, and injurious falls. Results: Tools such as event monitoring and natural language processing can inexpensively detect certain types of <span class="hlt">adverse</span> events in clinical databases. These approaches already work well for some types of <span class="hlt">adverse</span> events, including <span class="hlt">adverse</span> drug events and nosocomial infections, and are in routine use in a few hospitals. In addition, it appears likely that these techniques will be adaptable in ways that allow detection of a broad array of <span class="hlt">adverse</span> events, especially as more medical information becomes computerized. Conclusion: Computerized detection of <span class="hlt">adverse</span> events will soon be practical on a widespread basis. PMID:12595401</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......322L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......322L"><span id="translatedtitle">Physiological and spectral characterization of the effects of <span class="hlt">atmospheric</span> carbon dioxide and tropospheric ozone on wheat and soybean cultivars grown under well-watered and restricted moisture <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leblanc, Eric</p> <p></p> <p>Vegetative responses to elevated <span class="hlt">atmospheric</span> carbon dioxide (CO 2) and tropospheric ozone (O3) have been extensively characterized for many agricultural crops. Generally, positive effects of elevated CO 2 concentrations may be partially or completely counteracted by high O3 concentrations. The objectives of these studies were to investigate the single and combined effects of realistic, near-future, levels of above-ambient CO2 (+150 muL L-1) and O3 (+35 +/- 5 nL L-1) on wheat (Triticum aestivum) and soybean (Glycine max) cultivars grown under well-watered (WW) and restricted moisture (RM) <span class="hlt">conditions</span>. Wheat was grown in open-top chambers during the spring of 1995 to 1997, while soybean was grown during summers from 1994 to 1997. In wheat, responses to air quality were generally similar under WW and RM <span class="hlt">conditions</span>. Elevated CO2 enhanced photosynthesis (Pn) even with high O3 concentrations. Stomatal conductances (gs) were reduced by CO2 and O3, and even more when combined at high levels, which led to increases in leaf temperature (Tleaf), no changes in transpiration (E) rates, and increases in water-use efficiency (WUE). Intercellular CO2 concentrations (C i) increased much more from elevated CO2 than from O 3 from pre- to post-flowering. Damage to the photosynthetic apparatus from O3 was undetectable with chlorophyll fluorescence. Variations in chlorophyll a and b were not a sensitive indicator of air quality-induced stress. Leaf area index (LAI) was not significantly affected by the treatments; above ground biomass and yields were significantly reduced by high O3 <span class="hlt">conditions</span>. Seed test weights, milling quality scores, and flour yields were reduced, while flour protein was increased by high O3 concentrations under WW <span class="hlt">conditions</span>. In soybean, CO2 stimulated Pn regardless of the O3 level. Responses in gs, Tleaf, WUE, chlorophyll fluorescence, and chlorophyll contents were similar to those observed in wheat. LAI, biomass, and yields were reduced by high O3 <span class="hlt">conditions</span>. High</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4093120','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4093120"><span id="translatedtitle">Effects of Hydrated Potato Starch on the Quality of Low-fat Ttoekgalbi (Korean Traditional Patty) Packaged in Modified <span class="hlt">Atmosphere</span> <span class="hlt">Conditions</span> during Storage</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Muhlisin, S. M. Kang; Choi, W. H.; Lee, K. T.; Cheong, S. H.; Lee, S. K.</p> <p>2012-01-01</p> <p>This study was carried out to investigate the effects of hydrated potato starch on the quality of low-fat ttoekgalbi (Korean traditional patty) packaged in modified <span class="hlt">atmosphere</span> <span class="hlt">conditions</span> during storage. The ttoekgalbi was prepared from 53.2% lean beef, 13.9% lean pork, 9.3% pork fat, and 23.6% other ingredients. Two low-fat ttoekgalbi treatments were prepared by substituting pork fat with hydrated potato starch; either by 50% fat replacement (50% FR) or 100% fat replacement (100% FR). Both 50% and 100% FR increased the moisture, crude protein, and decreased fat content, cooking loss, and hardness. For MAP studies, 200 g of ttoekgalbi were placed on the tray and filled with gas composed of 70% O2: 30% CO2 (70% O2-MAP) and 30% CO2: 70% N2 (70% N2-MAP), and were stored at 5°C for 12 d. During the storage time, both 50% and 100% FR showed higher protein deterioration, while no differences were found in CIE a*, CIE L*, lipid oxidation, and bacterial counts in comparison to control. The ttoekgalbi with 70% O2-MAP was more red, lighter in color, and showed higher TBARS values compared with 70% N2-MAP. The meat with 70% N2-MAP showed lower aerobic bacterial counts in control than those with 70% O2-MAP. The lower anaerobic bacterial counts were observed only in 50% FR and 100% FR packed with 70% N2-MAP in comparison with 70% O2-MAP. In conclusion, the fat replacement with hydrated potato starch showed no negative effects on the quality of low fat ttoekgalbi during storage and 70% N2-MAP was better than 70% O2-MAP for low-fat ttoekgalbi packaging. PMID:25049619</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27357302','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27357302"><span id="translatedtitle">[<span class="hlt">Adverse</span> ocular effects of vaccinations].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ness, T; Hengel, H</p> <p>2016-07-01</p> <p>Vaccinations are very effective measures for prevention of infections but are also associated with a long list of possible side effects. <span class="hlt">Adverse</span> ocular effects following vaccination have been rarely reported or considered to be related to vaccinations. Conjunctivitis is a frequent sequel of various vaccinations. Oculorespiratory syndrome and serum sickness syndrome are considered to be related to influenza vaccinations. The risk of reactivation or initiation of autoimmune diseases (e. g. uveitis) cannot be excluded but has not yet been proven. Overall the benefit of vaccination outweighs the possible but very low risk of ocular side effects. PMID:27357302</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27514303','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27514303"><span id="translatedtitle"><span class="hlt">Adverse</span> Effects of Electroconvulsive Therapy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andrade, Chittaranjan; Arumugham, Shyam Sundar; Thirthalli, Jagadisha</p> <p>2016-09-01</p> <p>Electroconvulsive therapy (ECT) is an effective treatment commonly used for depression and other major psychiatric disorders. We discuss potential <span class="hlt">adverse</span> effects (AEs) associated with ECT and strategies for their prevention and management. Common acute AEs include headache, nausea, myalgia, and confusion; these are self-limiting and are managed symptomatically. Serious but uncommon AEs include cardiovascular, pulmonary, and cerebrovascular events; these may be minimized with screening for risk factors and by physiologic monitoring. Although most cognitive AEs of ECT are short-lasting, troublesome retrograde amnesia may rarely persist. Modifications of and improvements in treatment techniques minimize cognitive and other AEs. PMID:27514303</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003BoLMe.107..219K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003BoLMe.107..219K"><span id="translatedtitle">Concentrations of 222Rn, Its Short-Lived Daughters And 212Pb And Their Ratios Under Complex <span class="hlt">Atmospheric</span> <span class="hlt">Conditions</span> And Topography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kataoka, Toshio; Yunoki, Eiji; Shimizu, Mitsuo; Mori, Tadashige; Tsukamoto, Osamu; Takahashi, Satoshi; Fudeyasu, Hironori; Ohashi, Yukitaka; Sahashi, Ken; Maitani, Toshihiko; Miyashita, Koh'ichi; Iwata, Toru; Sasaki, Takayuki; Fujikawa, Yoko; Kudo, Akira; Shaw, Roger H.</p> <p></p> <p><span class="hlt">Atmospheric</span> activity concentrations of 212Pb and short-lived 222Rndaughters, together with meteorological elements, have been observed continuously atthree sites at Kamisaibara Village in Japan. In addition, <span class="hlt">atmospheric</span> activity concentrationof 222Rn, equilibrium-equivalent concentration of 222Rn and conditionsof the lower <span class="hlt">atmosphere</span> were observed for three intensive observation periods at Akawase,one of the three sites in Kamisaibara Village. The equilibrium-equivalent concentration of222Rn is almost the same as the <span class="hlt">atmospheric</span> activity concentration of short-lived222Rn daughters.The activity concentrations of 212Pb and the short-lived 222Rn daughtersand their ratio were low in the daytime owing to convective mixing, and high at nightowing to the surface-based inversion during periods of no precipitation. Their variationshave several patterns corresponding to the scale of the drainage wind or weak mixing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25622648','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25622648"><span id="translatedtitle"><span class="hlt">Adverse</span> drug reactions in dermatology.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferner, R E</p> <p>2015-03-01</p> <p><span class="hlt">Adverse</span> drug reactions (ADRs) - that is, unintended and harmful responses to medicines - are important to dermatologists because many present with cutaneous signs and because dermatological treatments can cause serious ADRs. The detection of ADRs to new drugs is often delayed because they have a long latency or are rare or unexpected. This means that ADRs to newer agents emerge only slowly after marketing. ADRs are part of the differential diagnosis of unusual rashes. A good drug history that includes details of drug dose, time-course of the reaction and factors that may make the patient more susceptible, will help. For example, Stevens-Johnson syndrome with abacavir is much commoner in patients with HLA-B*5701, and has a characteristic time course. Newer agents have brought newer reactions; for example, acneiform rashes associated with epidermal growth factor receptor inhibitors such as erlotinib. Older systemic agents used to treat skin disease, including corticosteroids and methotrexate, cause important ADRs. The <span class="hlt">adverse</span> effects of newer biological agents used in dermatology are becoming clearer; for example, hypersensitivity reactions or loss of efficacy from antibody formation and progressive multifocal leucoencephalopathy due to reactivation of latent JC (John Cunningham) virus infections during efalizumab treatment. Unusual or serious harm from medicines, including ADRs, medication errors and overdose, should be reported. The UK Yellow Card scheme is online, and patients can report their own ADRs. PMID:25622648</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21051267','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21051267"><span id="translatedtitle">[Recipients <span class="hlt">adverse</span> reactions: guidance supports].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bazin, A</p> <p>2010-12-01</p> <p>Since 1994, <span class="hlt">adverse</span> effects of transfusion transmitted to the French haemovigilance network are registered on "e-fit", the database of the French agency for the safety of health products (Afssaps). In order to improve their analysis, guidance supports have been made by Afssaps working groups. Each support deals with a blood transfusion side effect and is composed of five parts including pathophysiological mechanisms, diagnostic criteria, management recommendations, etiologic investigations and rules of filing the notification form on e-fit. The major characteristics of sheets published or soon-to-be published are presented: transfusion-related acute lung injury, transfusion-transmitted bacterial infection, non-haemolytic febrile reaction, allergic reaction, transfusion-associated circulatory overload, hypotensive transfusion reaction, alloimmunization, erythrocyte incompatibility reaction and hemosiderosis. These new supports give relevant guidelines allowing a better analysis and evaluation of recipients' <span class="hlt">adverse</span> reactions, particularly their diagnosis, gravity and accountability. They could also initiate studies in European and international haemovigilance and transfusion networks. PMID:21051267</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22578374','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22578374"><span id="translatedtitle"><span class="hlt">Adverse</span> effects of plasma transfusion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pandey, Suchitra; Vyas, Girish N</p> <p>2012-05-01</p> <p>Plasma utilization has increased over the past two decades, and there is a growing concern that many plasma transfusions are inappropriate. Plasma transfusion is not without risk, and certain complications are more likely with plasma than other blood components. Clinical and laboratory investigations of the patients suffering reactions after infusion of fresh-frozen plasma (FFP) define the etiology and pathogenesis of the panoply of <span class="hlt">adverse</span> effects. We review here the pathogenesis, diagnosis, and management of the risks associated with plasma transfusion. Risks commonly associated with FFP include: 1) transfusion-related acute lung injury, 2) transfusion-associated circulatory overload, and 3) allergic and/or anaphylactic reactions. Other less common risks include 1) transmission of infections, 2) febrile nonhemolytic transfusion reactions, 3) red blood cell alloimmunization, and 4) hemolytic transfusion reactions. The effects of pathogen inactivation or reduction methods on these risks are also discussed. Fortunately, a majority of the <span class="hlt">adverse</span> effects are not lethal and are adequately treated in clinical practice. PMID:22578374</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1259798','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1259798"><span id="translatedtitle">Adding Complex Terrain and Stable <span class="hlt">Atmospheric</span> <span class="hlt">Condition</span> Capability to the OpenFOAM-based Flow Solver of the Simulator for On/Offshore Wind Farm Applications (SOWFA): Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Churchfield, M. J.; Sang, L.; Moriarty, P. J.</p> <p>2013-09-01</p> <p>This paper describes changes made to NREL's OpenFOAM-based wind plant aerodynamics solver such that it can compute the stably stratified <span class="hlt">atmospheric</span> boundary layer and flow over terrain. Background about the flow solver, the Simulator for Off/Onshore Wind Farm Applications (SOWFA) is given, followed by details of the stable stratification/complex terrain modifications to SOWFA, along with somepreliminary results calculations of a stable <span class="hlt">atmospheric</span> boundary layer and flow over a simply set of hills.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Wallerstein&pg=3&id=EJ450181','ERIC'); return false;" href="http://eric.ed.gov/?q=Wallerstein&pg=3&id=EJ450181"><span id="translatedtitle">"<span class="hlt">Adversative</span> Conjunction": The Poetics of Linguistic Opposition.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wallerstein, Nicholas</p> <p>1992-01-01</p> <p>The general use of <span class="hlt">adversative</span> conjunction in (primarily) English and U.S. poetry is outlined. The contention is that the <span class="hlt">adversative</span> is not merely a grammatical convenience but sometimes a highly functional tool of rhetorical strategy. (36 references) (LB)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/866746','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/866746"><span id="translatedtitle"><span class="hlt">Atmospheric</span> optical calibration system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hulstrom, Roland L.; Cannon, Theodore W.</p> <p>1988-01-01</p> <p>An <span class="hlt">atmospheric</span> optical calibration system is provided to compare actual <span class="hlt">atmospheric</span> optical <span class="hlt">conditions</span> to standard <span class="hlt">atmospheric</span> optical <span class="hlt">conditions</span> on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual <span class="hlt">conditions</span> vary from standard <span class="hlt">conditions</span>. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard <span class="hlt">atmospheric</span> optical <span class="hlt">condition</span> response on a real-time basis as the device is being tested in actual outdoor <span class="hlt">conditions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7169805','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7169805"><span id="translatedtitle"><span class="hlt">Atmospheric</span> optical calibration system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hulstrom, R.L.; Cannon, T.W.</p> <p>1988-10-25</p> <p>An <span class="hlt">atmospheric</span> optical calibration system is provided to compare actual <span class="hlt">atmospheric</span> optical <span class="hlt">conditions</span> to standard <span class="hlt">atmospheric</span> optical <span class="hlt">conditions</span> on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual <span class="hlt">conditions</span> vary from standard <span class="hlt">conditions</span>. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard <span class="hlt">atmospheric</span> optical <span class="hlt">condition</span> response on a real-time basis as the device is being tested in actual outdoor <span class="hlt">conditions</span>. 7 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25687949','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25687949"><span id="translatedtitle">The reactions of N-methylformamide and N,N-dimethylformamide with OH and their photo-oxidation under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span>: experimental and theoretical studies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bunkan, Arne Joakim C; Hetzler, Jens; Mikoviny, Tomáš; Wisthaler, Armin; Nielsen, Claus J; Olzmann, Matthias</p> <p>2015-03-14</p> <p>The reactions of OH radicals with CH3NHCHO (N-methylformamide, MF) and (CH3)2NCHO (N,N-dimethylformamide, DMF) have been studied by experimental and computational methods. Rate coefficients were determined as a function of temperature (T = 260-295 K) and pressure (P = 30-600 mbar) by the flash photolysis/laser-induced fluorescence technique. OH radicals were produced by laser flash photolysis of 2,4-pentanedione or tert-butyl hydroperoxide under pseudo-first order <span class="hlt">conditions</span> in an excess of the corresponding amide. The rate coefficients obtained show negative temperature dependences that can be parameterized as follows: kOH+MF = (1.3 ± 0.4) × 10(-12) exp(3.7 kJ mol(-1)/(RT)) cm(3) s(-1) and kOH+DMF = (5.5 ± 1.7) × 10(-13) exp(6.6 kJ mol(-1)/(RT)) cm(3) s(-1). The rate coefficient kOH+MF shows very weak positive pressure dependence whereas kOH+DMF was found to be independent of pressure. The Arrhenius equations given, within their uncertainty, are valid for the entire pressure range of our experiments. Furthermore, MF and DMF smog-chamber photo-oxidation experiments were monitored by proton-transfer-reaction time-of-flight mass spectrometry. <span class="hlt">Atmospheric</span> MF photo-oxidation results in 65% CH3NCO (methylisocyanate), 16% (CHO)2NH, and NOx-dependent amounts of CH2[double bond, length as m-dash]NH and CH3NHNO2 as primary products, while DMF photo-oxidation results in around 35% CH3N(CHO)2 as primary product and 65% meta-stable (CH3)2NC(O)OONO2 degrading to NOx-dependent amounts of CH3N[double bond, length as m-dash]CH2 (N-methylmethanimine), (CH3)2NNO (N-nitroso dimethylamine) and (CH3)2NNO2 (N-nitro dimethylamine). The potential for nitramine formation in MF photo-oxidation is comparable to that of methylamine whereas the potential to form nitrosamine and nitramine in DMF photo-oxidation is larger than for dimethylamine. Quantum chemistry supported <span class="hlt">atmospheric</span> degradation mechanisms for MF and DMF are presented. Rate coefficients and initial branching ratios</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6512405','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6512405"><span id="translatedtitle">Jovian <span class="hlt">atmospheres</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allison, M.; Travis, L.D.</p> <p>1986-10-01</p> <p>A conference on the <span class="hlt">atmosphere</span> of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, <span class="hlt">atmospheric</span> structure, global dynamics, synoptic features and processes, <span class="hlt">atmospheric</span> dynamics, and future spaceflight opportunities. A session on the <span class="hlt">atmospheres</span> of Uranus and Neptune was included, and the <span class="hlt">atmosphere</span> of Saturn was discussed in several papers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=technical+AND+collection+AND+data&pg=5&id=EJ1064058','ERIC'); return false;" href="http://eric.ed.gov/?q=technical+AND+collection+AND+data&pg=5&id=EJ1064058"><span id="translatedtitle">Untold Stories of Fieldworkers Working Amid <span class="hlt">Adverse</span> <span class="hlt">Conditions</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Serekoane, Motsaathebe; Sharp, Carla; Skinner, Donald; Marais, Lochner</p> <p>2014-01-01</p> <p>Working in unfamiliar contexts and often alone, fieldworkers may face challenges for which their training and previous experience has not prepared them. While there is literature about the technical, ethical and moral aspects of fieldwork, there is little focusing on fieldworkers' actual experiences. Additionally, there is little constructive…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930047408&hterms=Bruker&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBruker','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930047408&hterms=Bruker&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBruker"><span id="translatedtitle">High-resolution studies of <span class="hlt">atmospheric</span> IR emission spectra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Murcray, F. J.; Murcray, F. H.; Goldman, A.; Blatherwick, R. D.; Murcray, D. G.</p> <p>1991-01-01</p> <p><span class="hlt">Atmospheric</span> emission spectra obtained with two different spectrometer systems are presented. The first system (the BOMEM Michelson interferometer) is designed for emission work. Spectra were obtained under <span class="hlt">adverse</span> <span class="hlt">conditions</span> in the Antarctic, and are still of good absolute accuracy. The second system (a modified Bruker Instruments IFS120 very high spectral resolution interferometer) demonstrates the sensitivity that can be achieved even at higher spectral resolution. This system shows that mid-IR <span class="hlt">atmospheric</span> emission spectra can be obtained with a good SNR in a reasonable length of time at a relatively high resolution. A properly designed high resolution system should achieve high accuracy, sensitivity, and resolution, thereby permitting measurements of many <span class="hlt">atmospheric</span> constituents when solar spectra cannot be obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25122950','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25122950"><span id="translatedtitle">Investigation of time-resolved <span class="hlt">atmospheric</span> <span class="hlt">conditions</span> and indoor/outdoor particulate matter concentrations in homes with gas and biomass cook stoves in Nogales, Sonora, Mexico.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Holmes, Heather A; Pardyjak, Eric R</p> <p>2014-07-01</p> <p>This paper reports findings from a case study designed to investigate indoor and outdoor air quality in homes near the United States-Mexico border During the field study, size-resolved continuous particulate matter (PM) concentrations were measured in six homes, while outdoor PM was simultaneously monitored at the same location in Nogales, Sonora, Mexico, during March 14-30, 2009. The purpose of the experiment was to compare PM in homes using different fuels for cooking, gas versus biomass, and to obtain a spatial distribution of outdoor PM in a region where local sources vary significantly (e.g., highway, border crossing, unpaved roads, industry). Continuous PM data were collected every 6 seconds using a valve switching system to sample indoor and outdoor air at each home location. This paper presents the indoor PM data from each home, including the relationship between indoor and outdoor PM. The meteorological <span class="hlt">conditions</span> associated with elevated ambient PM events in the region are also discussed. Results indicate that indoor air pollution has a strong dependence on cooking fuel, with gas stoves having hourly averaged median PM3 concentrations in the range of 134 to 157 microg m(-3) and biomass stoves 163 to 504 microg m(-1). Outdoor PM also indicates a large spatial heterogeneity due to the presence of microscale sources and meteorological influences (median PM3: 130 to 770 microg m(-3)). The former is evident in the median and range of daytime PM values (median PM3: 250 microg m(-3), maximum: 9411 microg m(-3)), while the meteorological influences appear to be dominant during nighttime periods (median PM3: 251 microg m(-3), maximum: 10,846 microg m(-3)). The <span class="hlt">atmospheric</span> stability is quantified for three nighttime temperature inversion episodes, which were associated with an order of magnitude increase in PM10 at the regulatory monitor in Nogales, AZ (maximum increase: 12 to 474 microg m(-3)). Implications: Regulatory air quality standards are based on outdoor</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACPD...1111281Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACPD...1111281Y"><span id="translatedtitle">The size-dependent charge fraction of sub-3-nm particles as a key diagnostic of competitive nucleation mechanisms under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, F.; Turco, R.</p> <p>2011-04-01</p> <p>A clear physical understanding of <span class="hlt">atmospheric</span> particle nucleation mechanisms is critical in assessing the influences of aerosols on climate and climate variability. Currently, several mechanisms have been proposed and are being employed to interpret field observations of nucleation events. Roughly speaking, the two most likely candidates are neutral cluster nucleation (NCN) and ion-mediated nucleation (IMN). Detailed nucleation event data has been obtained in boreal forests. In one set of analyses of these measurements, NCN was suggested as the dominant formation mode, while in another, it was IMN. Obviously, information on the electrical charge distribution carried by the nucleating clusters themselves is the key to identifying the relative contributions of neutral and ion-mediated processes under various <span class="hlt">conditions</span>. Fortunately, ground-breaking measurements of the charged states or fractions of ambient nanometer-sized particles soon after undergoing nucleation are now available to help resolve the main pathway. In the present study, the size-dependent "apparent" formation rates and fractions of charged and neutral particles are simulated with a detailed kinetic model. We show that the predicted "apparent" formation rates of charged and neutral particles at 2 nm agree well with the corresponding values derived from the boreal forest data, but the "apparent" contribution of ion-based nucleation increases by up to ~ one order of magnitude as the size of particles decreases from 2 nm to ~1.5 nm. It appears that most of the neutral particles detected at sizes around 2 nm are in reality initially formed on ionic cores that are neutralized before the particles grow to this size. Thus, although the apparent rate of formation of neutral 2-nm particles might seem to be dominated by a neutral clustering process, in fact those particles are largely the result of an ion-induced nucleation mechanism. This point is clarified when the formation rates of smaller particles (e</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACP....11.9451Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACP....11.9451Y"><span id="translatedtitle">The size-dependent charge fraction of sub-3-nm particles as a key diagnostic of competitive nucleation mechanisms under <span class="hlt">atmospheric</span> <span class="hlt">conditions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, F.; Turco, R. P.</p> <p>2011-09-01</p> <p>A clear physical understanding of <span class="hlt">atmospheric</span> particle nucleation mechanisms is critical in assessing the influences of aerosols on climate and climate variability. Currently, several mechanisms have been proposed and are being employed to interpret field observations of nucleation events. Roughly speaking, the two most likely candidates are neutral cluster nucleation (NCN) and ion-mediated nucleation (IMN). Detailed nucleation event data has been obtained in boreal forests. In one set of analyses of these measurements, NCN was suggested as the dominant formation mode, while in another, it was IMN. Information on the electrical charge distribution carried by the nucleating clusters is one key for identifying the relative contributions of neutral and ion-mediated processes under various <span class="hlt">conditions</span>. Fortunately, ground-breaking measurements of the charged states or fractions of ambient nanometer-sized particles soon after undergoing nucleation are now available to help resolve the main pathways. In the present study, the size-dependent "apparent" formation rates and fractions of charged and neutral particles in a boreal forest setting are simulated with a detailed kinetic model. We show that the predicted "apparent" formation rates of charged and neutral particles at 2 nm for eight representative case study days agree well with the corresponding values based on observations. In the simulations, the "apparent" contribution of ion-based nucleation increases by up to ~one order of magnitude as the size of "sampled" particles is decreased from 2 nm to ~1.5 nm. These results suggest that most of the neutral particles sampled in the field at sizes around 2 nm are in reality initially formed on ionic cores that are neutralized before the particles grow to this size. Thus, although the apparent rate of formation of neutral 2-nm particles might seem to be dominated by a neutral clustering process, in fact those particles may be largely the result of an ion-induced nucleation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5689785','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5689785"><span id="translatedtitle">Fiber optics in <span class="hlt">adverse</span> environments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lyous, P.B.</p> <p>1982-01-01</p> <p>Radiation effects in optical fibers are considered, taking into account recent progress in the investigation of radiation resistant optical fibers, radiation damage in optical fibers, radiation-induced transient absorption in optical fibers, X-ray-induced transient attenuation at low temperatures in polymer clad silica (PCS) fibers, optical fiber composition and radiation hardness, the response of irradiated optical waveguides at low temperatures, and the effect of ionizing radiation on fiber-optic waveguides. Other topics explored are related to environmental effects on components of fiber optic systems, and radiation detection systems using optical fibers. Fiber optic systems in <span class="hlt">adverse</span> environments are also discussed, giving attention to the survivability of Army fiber optics systems, space application of fiber optics systems, fiber optic wavelength multiplexing for civil aviation applications, a new fiber optic data bus topology, fiber optics for aircraft engine/inlet control, and application of fiber optics in high voltage substations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/3302664','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/3302664"><span id="translatedtitle"><span class="hlt">Adverse</span> reactions to food additives.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Simon, R A</p> <p>1986-01-01</p> <p>There are thousands of agents that are intentionally added to the food that we consume. These include preservatives, stabilizers, conditioners, thickeners, colorings, flavorings, sweeteners, antioxidants, etc. etc. Yet only a surprisingly small number have been associated with hypersensitivity reactions. Amongst all the additives, FD&C dyes have been most frequently associated with <span class="hlt">adverse</span> reactions. Tartrazine is the most notorious of them all; however, critical review of the medical literature and current Scripps Clinic studies would indicate that tartrazine has been confirmed to be at best only occasionally associated with flares of urticaria or asthma. There is no convincing evidence in the literature of reactivity to the other azo or nonazo dyes. This can also be said of BHA/BHT, nitrites/nitrates and sorbates. Parabens have been shown to elicit IgE mediated hypersensitivity reactions when used as pharmaceutical preservatives; however, as with the other additives noted above, ingested parabens have only occasionally been associated with <span class="hlt">adverse</span> reactions. MSG, the cause of the 'Chinese restaurant syndrome' has only been linked to asthma in one report. Sulfiting agents used primarily as food fresheners and to control microbial growth in fermented beverages have been established as the cause of any where from mild to severe and even fatal reactions in at least 5% of the asthmatic population. Other reactions reported to follow sulfite ingestion include anaphylaxis, gastro intestinal complaints and dermatological eruptions. The prevalence of these non asthmatic reactions is unknown. The mechanism of sulfite sensitive asthma is also unknown but most likely involves hyperreactivity to inhale SO2 in the great majority of cases; however, there are reports of IgE mediated reactions and other sulfite sensitive asthmatics have been found with low levels of sulfite oxidase; necessary to oxidize endogenous sulfite to sulfate. PMID:3302664</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1810225G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1810225G&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Adverse</span> weather impacts on arable cropping systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gobin, Anne</p> <p>2016-04-01<