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Sample records for measure road profiles

  1. Estimation of road profile variability from measured vehicle responses

    NASA Astrophysics Data System (ADS)

    Fauriat, W.; Mattrand, C.; Gayton, N.; Beakou, A.; Cembrzynski, T.

    2016-05-01

    When assessing the statistical variability of fatigue loads acting throughout the life of a vehicle, the question of the variability of road roughness naturally arises, as both quantities are strongly related. For car manufacturers, gathering information on the environment in which vehicles evolve is a long and costly but necessary process to adapt their products to durability requirements. In the present paper, a data processing algorithm is proposed in order to estimate the road profiles covered by a given vehicle, from the dynamic responses measured on this vehicle. The algorithm based on Kalman filtering theory aims at solving a so-called inverse problem, in a stochastic framework. It is validated using experimental data obtained from simulations and real measurements. The proposed method is subsequently applied to extract valuable statistical information on road roughness from an existing load characterisation campaign carried out by Renault within one of its markets.

  2. Smooth connection method of segment test data in road surface profile measurement

    NASA Astrophysics Data System (ADS)

    Duan, Hu-Ming; Ma, Ying; Shi, Feng; Zhang, Kai-Bin; Xie, Fei

    2012-01-01

    It's reviewed that the measurement system of road surface profile and the calculation method of segment road test data have been introduced. Because of there are sudden vertical steps at the connection points of segment data which will influence the application of road surface data in automotive engineering. So a new smooth connection method of segment test data is proposed which revised the sudden vertical steps connection by the Signal Local Baseline Adjustment (SLBA) method. Besides, there is an actual example which mentioned the detailed process of the smooth connection of segment test data by the SLBA method and the adjusting results at these connection points. The application and calculation results show that the SLBA method is simple and has achieved obvious effect in smooth connection of the segment road test data. The method of SLBA can be widely applied to segment road surface data processing or the long period vibration signal processing.

  3. Smooth connection method of segment test data in road surface profile measurement

    NASA Astrophysics Data System (ADS)

    Duan, Hu-Ming; Ma, Ying; Shi, Feng; Zhang, Kai-Bin; Xie, Fei

    2011-12-01

    It's reviewed that the measurement system of road surface profile and the calculation method of segment road test data have been introduced. Because of there are sudden vertical steps at the connection points of segment data which will influence the application of road surface data in automotive engineering. So a new smooth connection method of segment test data is proposed which revised the sudden vertical steps connection by the Signal Local Baseline Adjustment (SLBA) method. Besides, there is an actual example which mentioned the detailed process of the smooth connection of segment test data by the SLBA method and the adjusting results at these connection points. The application and calculation results show that the SLBA method is simple and has achieved obvious effect in smooth connection of the segment road test data. The method of SLBA can be widely applied to segment road surface data processing or the long period vibration signal processing.

  4. Road analysis: a tool for cost-effective rehabilitation measures for Finnish roads

    NASA Astrophysics Data System (ADS)

    Roimela, Petri; Salmenkaita, Seppo; Maijala, Pekka; Saarenketo, Timo

    2000-04-01

    Public funding for road network maintenance has decreased 30% during the last few years in Finland. Reduced resources, together with the current rehabilitation strategies, will in the long term result in increasing deterioration of the Finnish road network. For this reason road rehabilitation funding should be focused more specifically on those roads and road sections requiring measures and these measures should be optimized to ensure that only the specific problem structure will be repaired. Roadscanners Oy, in cooperation with the Finnish National Road Administration (Finnra), has developed a new and effective Road Analysis technique to survey the condition of roads and road networks. Road Analysis is based on the integrated analysis of the measured data collected from the road under survey. The basic survey methods used in Road Analysis include Ground Penetrating Data (GPR), falling weight deflectometer (FWD), roughness and rutting measurements, pavement distress mapping and GPS-positioning, as well as reference drilling based on preliminary GPR data analysis. The collected road survey data is processed, interpreted, analyzed and classified using Road Doctor software, specifically developed for this purpose. GPR measurements in road analysis are carried out using a 400 MHz ground-coupled antenna and a 1.0 GHz horn antenna. Horn antenna data is used to measure the thickness of the pavement and base course layers, as well as to evaluate their quality based on their dielectric properties. The 400 MHz ground-coupled data is used to estimate the thickness of the pavement structure and embankment. Ground-coupled antenna data is used for subgrade quality estimations and in evaluating the causes of subgrade- related frost defects. GPR data also provides important location information about special structures, such as steel reinforcements, cables and pipelines. Road Analysis includes a classification of the critical elements affecting the lifetime of the road: (1

  5. Vehicular emission factors and chemical profile of Particulate Matter measured in two road tunnels in the Metropolitan Area of Sao Paulo, Brazil

    NASA Astrophysics Data System (ADS)

    Nogueira, T.; Miranda, R. M.; Dominutti, P. A.; Hetem, I. G.; Fornaro, A.; Andrade, M.

    2013-12-01

    The main source of air pollution in the Metropolitan Area of São Paulo (MASP), Brazil, is vehicle exhaust. In this study, trace-element concentrations inside and outside of two traffic tunnels in the MASP are shown. The experiments were conducted in May and July 2011, respectively, in the Jânio Quadros (JQT) and Rodoanel (RAT) road tunnels, both located in MASP. The JQT carries mainly light-duty vehicles (LDV), whereas the RAT carries LDVs and heavy-duty vehicles (HDV). Hourly carbon dioxide, carbon monoxide, nitrogen oxides and sulfur dioxide were measured during the sampling campaign. Particulate matter (PM2.5 and PM2.5-10) samples were collected 6-h (daytime) and 12-h (overnight), employing gravimetric analysis to quantify PM mass concentration; reflectance to quantify black carbon (BC) concentrations and X-ray fluorescence to characterize elemental composition. Mean concentrations for PM2.5 and BC inside the JQT were 41(×11), and 19(×9) μg/m3, respectively. In the RAT mean concentrations were 175(×61), and 140(×78) μg/m3, for PM2.5 and BC, respectively. Emission Factors (EFs) for PM2.5, PM2.5-10, BC and trace metal (Na to Pb) from mobile sources operating under real-world conditions were determined using these traffic tunnels in the MASP as experimental set-up. LDV emission factors were 45 × 18 mg/km, 39 × 17 mg/km, 306 × 121 μg/km, 108 × 46 μg/km, 742 × 453 μg/km, 624 × 261 μg/km, and 33 × 15 μg/km, for PM2.5, BC, Na, P, S, Cu, and Pb, respectively. HDV emission factors were 326 × 119 mg/km, 231 × 98 mg/km, 446 × 218 μg/km, 384 × 143 μg/km, 4618 × 1878 μg/km, 44 × 18 μg/km, and 46 × 20 μg/km, for PM2.5, BC, Na, P, S, Cu, and Pb, respectively. In general, the mean contribution of HDVs to the emissions of fine particles was from 1.4 to 7.3 times higher than that of LDVs. In addition, the data show a significant reduction in the EFs values when compared with data obtained in the last campaign held in the MASP in 2004. The reduction

  6. Profiles in Measurement.

    ERIC Educational Resources Information Center

    Ludlow, Larry H.; Wright, Benjamin Drake; Linacre, John Michael; Webster, Linda; Andrich, David

    1998-01-01

    Four of the articles in this section profile major figures in measurement: (1) Sir Francis Galton (Larry Ludlow); (2) Georg Rasch (Benjamin Wright); (3) Benjamin Wright (John Michael Linacre); and (4) David Andrich (Linda Webster). The fifth article, by David Andrich, presents insights gained into the Rasch model. (SLD)

  7. A statistical model for road surface friction forecasting applying optical road weather measurements

    NASA Astrophysics Data System (ADS)

    Hippi, M.; Juga, I.; Nurmi, P.

    2009-09-01

    Road surface friction is defined as the grip between car tyre and underlying surface. Poor friction often plays a crucial role in wintertime car accidents. Friction can decrease dramatically during snowfall or when wet road surface temperature falls below zero. Even a thin layer of ice or snow can decrease friction substantially increasing the risk of accidents. Many studies have shown that road surface temperature, road conditions and friction can fluctuate dramatically within short distances under specific weather situations. Friction or grip can be improved with road maintenance activities like salting and gritting. Salting will melt the ice or snow layer, whereas gritting will improve the grip. Salting is effective only above -5C temperatures. Light snowfall together with low temperatures can result in very slippery driving conditions. Finnish Road Administration's observing network covers c. 500 road weather stations in Finland. Almost 100 of them are equipped with optical sensors (in winter 2008-2009). The number of optical sensors has increased remarkably during past few years. The optical measuring devices are Vaisala DSC111 sensors which measure the depth of water, snow and ice on the road surface and also produce an estimate of the state of road and prevailing friction. Observation data from road weather stations with optical sensors were collected from winter 2007/08, and a couple of representative (from a weather perspective) stations were selected for detailed statistical analysis. The purpose of the study was to find a statistical relationship between the observed values and, especially, the correlation between friction and other road weather parameters. Consequently, a model based on linear regression was developed. With the model friction being the dependent variable, the independent variables having highest correlations were the composite of ice and snow (water content) on the road, and the road surface temperature. In the case of a wet road

  8. Adaptive super-twisting observer for estimation of random road excitation profile in automotive suspension systems.

    PubMed

    Rath, J J; Veluvolu, K C; Defoort, M

    2014-01-01

    The estimation of road excitation profile is important for evaluation of vehicle stability and vehicle suspension performance for autonomous vehicle control systems. In this work, the nonlinear dynamics of the active automotive system that is excited by the unknown road excitation profile are considered for modeling. To address the issue of estimation of road profile, we develop an adaptive supertwisting observer for state and unknown road profile estimation. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is proven. Simulation results with Ford Fiesta MK2 demonstrate the effectiveness of the proposed observer for state and unknown input estimation for nonlinear active suspension system. PMID:24683321

  9. Adaptive super-twisting observer for estimation of random road excitation profile in automotive suspension systems.

    PubMed

    Rath, J J; Veluvolu, K C; Defoort, M

    2014-01-01

    The estimation of road excitation profile is important for evaluation of vehicle stability and vehicle suspension performance for autonomous vehicle control systems. In this work, the nonlinear dynamics of the active automotive system that is excited by the unknown road excitation profile are considered for modeling. To address the issue of estimation of road profile, we develop an adaptive supertwisting observer for state and unknown road profile estimation. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is proven. Simulation results with Ford Fiesta MK2 demonstrate the effectiveness of the proposed observer for state and unknown input estimation for nonlinear active suspension system.

  10. Adaptive Super-Twisting Observer for Estimation of Random Road Excitation Profile in Automotive Suspension Systems

    PubMed Central

    Rath, J. J.; Veluvolu, K. C.; Defoort, M.

    2014-01-01

    The estimation of road excitation profile is important for evaluation of vehicle stability and vehicle suspension performance for autonomous vehicle control systems. In this work, the nonlinear dynamics of the active automotive system that is excited by the unknown road excitation profile are considered for modeling. To address the issue of estimation of road profile, we develop an adaptive supertwisting observer for state and unknown road profile estimation. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is proven. Simulation results with Ford Fiesta MK2 demonstrate the effectiveness of the proposed observer for state and unknown input estimation for nonlinear active suspension system. PMID:24683321

  11. Effects of road mortality and mitigation measures on amphibian populations.

    PubMed

    Beebee, Trevor J C

    2013-08-01

    Road mortality is a widely recognized but rarely quantified threat to the viability of amphibian populations. The global extent of the problem is substantial and factors affecting the number of animals killed on highways include life-history traits and landscape features. Secondary effects include genetic isolation due to roads acting as barriers to migration. Long-term effects of roads on population dynamics are often severe and mitigation methods include volunteer rescues and under-road tunnels. Despite the development of methods that reduce road kill in specific locations, especially under-road tunnels and culverts, there is scant evidence that such measures will protect populations over the long term. There also seems little likelihood that funding will be forthcoming to ameliorate the problem at the scale necessary to prevent further population declines.

  12. On-road particulate emission measurement

    NASA Astrophysics Data System (ADS)

    Mazzoleni, Claudio

    Particulate matter (PM) suspended in the atmosphere has harmful health effects, contributes to visibility impairment, and affects atmospheric radiative transfer, thereby contributing to global change. Vehicles contribute substantially to the ambient PM concentration in urban areas, yet the fraction of ambient PM originating from vehicle emissions is poorly characterized because suitable measurement methods have not been available. This dissertation describes the development and the use of a new vehicle emission remote sensing system (VERSS) for the on-road measurement of PM emission factors for vehicles. The PM VERSS measures PM by ultraviolet backscattering and transmission. PM backscattering and transmission mass efficiencies have been calculated from Mie theory based on an homogeneous spherical model for gasoline particles and on a two-layers, spherical model for diesel particles. The VERSS was used in a large-scale study in Las Vegas, NV. A commercial gaseous VERSS was used for the measurement of gaseous emission factors (i.e., carbon monoxide, hydrocarbons, and nitrogen oxide). Speed and acceleration were also measured for each vehicle. A video image of each vehicle's rear license plate was acquired and license plate numbers were matched with the Clark County department of motor vehicle database to retrieve vehicle information such as model year, vehicle weight category and engine ignition type. PM VERSS has precisely estimated PM fleet average emission factors and clearly shown the dependence of PM emission factors on vehicle model year. Under mostly hot-stabilized operation, diesel vehicle PM emission factors are about 25 times higher than those of gasoline vehicles. Furthermore, the fleet frequency distributions of PM emission factors are highly skewed, meaning that most of the fleet emission factor is accounted for by a small portion of the fleet. The PM VERSS can measure PM emission factors for these high emitting vehicles on an individual basis. PM

  13. Road dust emissions from paved roads measured using different mobile systems.

    PubMed

    Pirjola, Liisa; Johansson, Christer; Kupiainen, Kaarle; Stojiljkovic, Ana; Karlsson, Hans; Hussein, Tareq

    2010-12-01

    Very few real-world measurements of road dust suspension have been performed to date. This study compares two different techniques (referred to as Sniffer and Emma) to measure road dust emissions. The main differences between the systems are the construction of the inlet, different instruments for recording particulate matter (PM) levels, and different loads on the wheel axes (the weight of Sniffer was much higher than that of Emma). Both systems showed substantial small-scale variations of emission levels along the road, likely depending on-road surface conditions. The variations observed correlated quite well, and the discrepancies are likely a result of variations in dust load on the road surface perpendicular to the driving direction that cause variations in the measurements depending on slightly different paths driven by the two vehicles. Both systems showed a substantial influence on the emission levels depending on the type of tire used. The summer tire showed much lower suspension than the winter tires (one nonstudded and one studded). However, the relative importance of the nonstudded versus studded tire was rather different. For the ratio of studded/nonstudded, Emma shows higher values on all road sections compared with Sniffer. Both techniques showed increased emission levels with increasing vehicle speed. When the speed increased from 50 to 80 km hr(-1), the relative concentrations increased by 30-170% depending on the tire type and dust load. However, for road sections that were very dirty, Sniffer showed a much higher relative increase in the emission level with the nonstudded tire. Sniffer's absolute concentrations were mostly higher than Emma's. Possible reasons for the differences are discussed in the paper. Both systems can be used for studying relative road dust emissions and for designing air quality management strategies. PMID:21243896

  14. Road salt emissions: A comparison of measurements and modelling using the NORTRIP road dust emission model

    NASA Astrophysics Data System (ADS)

    Denby, B. R.; Ketzel, M.; Ellermann, T.; Stojiljkovic, A.; Kupiainen, K.; Niemi, J. V.; Norman, M.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.; Sundvor, I.

    2016-09-01

    De-icing of road surfaces is necessary in many countries during winter to improve vehicle traction. Large amounts of salt, most often sodium chloride, are applied every year. Most of this salt is removed through drainage or traffic spray processes but a certain amount may be suspended, after drying of the road surface, into the air and will contribute to the concentration of particulate matter. Though some measurements of salt concentrations are available near roads, the link between road maintenance salting activities and observed concentrations of salt in ambient air is yet to be quantified. In this study the NORTRIP road dust emission model, which estimates the emissions of both dust and salt from the road surface, is applied at five sites in four Nordic countries for ten separate winter periods where daily mean ambient air measurements of salt concentrations are available. The model is capable of reproducing many of the salt emission episodes, both in time and intensity, but also fails on other occasions. The observed mean concentration of salt in PM10, over all ten datasets, is 4.2 μg/m3 and the modelled mean is 2.8 μg/m3, giving a fractional bias of -0.38. The RMSE of the mean concentrations, over all 10 datasets, is 2.9 μg/m3 with an average R2 of 0.28. The mean concentration of salt is similar to the mean exhaust contribution during the winter periods of 2.6 μg/m3. The contribution of salt to the kerbside winter mean PM10 concentration is estimated to increase by 4.1 ± 3.4 μg/m3 for every kg/m2 of salt applied on the road surface during the winter season. Additional sensitivity studies showed that the accurate logging of salt applications is a prerequisite for predicting salt emissions, as well as good quality data on precipitation. It also highlights the need for more simultaneous measurements of salt loading together with ambient air concentrations to help improve model parameterisations of salt and moisture removal processes.

  15. Closed-loop snowplow applicator control using road condition measurements

    NASA Astrophysics Data System (ADS)

    Erdogan, Gurkan; Alexander, Lee; Rajamani, Rajesh

    2011-04-01

    Closed-loop control of a snowplow applicator, based on direct measurement of the road surface condition, is a valuable technology for the optimisation of winter road maintenance costs and for the protection of the environment from the negative impacts of excessive usage of de-icing chemicals. To this end, a novel friction measurement wheel is designed to provide a continuous measurement of road friction coefficient, which is, in turn, utilised to control the applicator automatically on a snowplow. It is desired that the automated snowplow applicator deploy de-icing materials right from the beginning of any slippery surface detected by the friction wheel, meaning that no portion of the slippery road surface should be left untreated behind, as the snowplow travels over it at a reasonably high speed. This paper describes the developed wheel-based measurement system, the friction estimation algorithm and the expected performance of the closed-loop applicator system. Conventional and zero velocity applicators are introduced and their hardware time delays are measured in addition to the time delay of the friction estimation algorithm. The overall performance of the closed-loop applicator control system is shown to be reliable at typical snowplowing speeds if the zero velocity applicator is used.

  16. Fuel economy measurement road test procedure. SAE standard

    SciTech Connect

    1995-06-01

    This SAE Standard incorporates driving cycles that produce fuel consumption data relating to urban, suburban, and interstate driving patterns and is intended to be used to determine the relative fuel economy among vehicles and driving patterns under warmed-up conditions on test tracks, suitable roads, or chassis dynamometers. The cycle forms the basis of a cold-start test procedure described in SAE J1256. This document provides uniform testing procedures for measuring the fuel economy of light duty vehicles (motor vehicles designed primarily for transportation of persons or property and rated at 4,500 kg (10,000 lb) or less) on suitable roads.

  17. Measuring Electrical Current: The Roads Not Taken

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2011-01-01

    Recently I wrote about the standard Weston meter movement, that is at the heart of all modern analogue current measurements. Now I will discuss other techniques used to measure electric current that, despite being based on valid physical principles, are largely lost in technological history.

  18. Road and track irregularities: measurement, assessment and simulation

    NASA Astrophysics Data System (ADS)

    Haigermoser, Andreas; Luber, Bernd; Rauh, Jochen; Gräfe, Gunnar

    2015-07-01

    Road and track irregularities have an important influence on the dynamic behaviour of vehicles. Knowledge of their characteristics and magnitude is essential for the design of the vehicle but also for comparable homologation and acceptance tests as well as for the planning and management of track maintenance. Irregularities of tracks and roads are regularly measured using various measurement technologies. All have advantages and weaknesses and require several processing steps. Characterisation of irregularities is done in the distance as well as in the wavelength domain. For rail irregularities, various distance domain description methods have been proposed and are in use. Methods have been analysed and compared with regard to their processing steps. Several methods have been analysed using measured irregularity and vehicle response data. Characterisation in the wavelength domain is done in a similar way for track and road irregularities. Here, an important issue is the estimation of the power spectral densities and the approximation by analytical formulas. For rail irregularities, periodic defects also play an important role. The use of irregularities in simulations requires various processing steps if measured irregularities are used, as well as if synthetic data are utilised. This paper gives a quite complete overview of rail irregularities and points out similarities and differences to the road.

  19. Studies of some measures to reduce road dust emissions from paved roads in Scandinavia

    NASA Astrophysics Data System (ADS)

    Norman, Michael; Johansson, Christer

    In this paper we present quantitative assessments of different measures to reduce the PM10 levels along streets in Scandinavian cities based on tests in Stockholm. The effect of the use of studded tyres on concentrations in a street canyon has been quantitatively assessed using monitoring data. A 10% decrease in the fraction of studded tyres was estimated to reduce the weekly average street canyon PM10 levels (due to local road abrasion) by about 10 μg m -3 if only daytime and dry street conditions were considered. These results are obtained by correlating the increase in PM10 levels during autumn with the increased use of studded tyres. Since the share of studded tyres is around 75% in Stockholm during wintertime, the peak springtime PM10 levels that occur during dry road conditions would be substantially lower if the use of studded tyres were regulated. Intense sweeping or washing of the pavements resulted in marginal reductions (<10%) and will have no important influence on the PM10 levels with the methodologies and working machineries tested here. Application of calcium magnesium acetate (CMA, Ice Away, as 25% water solution) on the road surface of a highway during dry conditions resulted in an average reduction of around 35% in the daily PM10 averages. The most efficient way to reduce PM10 levels in the long-term and for a large area is to reduce the use of studded tyres, while application of CMA may be efficient to reduce peak levels, which frequently occur during dry road conditions in spring.

  20. Determination of the Stochastic Kinematic Excitation of the Car by the Real Profile of the Road Surface

    NASA Astrophysics Data System (ADS)

    Gardulski, Janusz; Adamczyk, Jan; Targosz, Jan

    2012-02-01

    In the research of model vehicle suspensions for the sake of the simple mathematical notation, in the equations it is assumed that the kinematic excitation is harmonic. This type of excitation is not present in the real exploitation condition of vehicles. In the effect the simulation testing of the suspension is only the estimate - it is not the equivalent of the real road conditions. The crosswise irregularities of the road surface (the profile) are random. The vehicle moving on such a road is excited with a stochastic excitation. The complete description of such process is very difficult. With its description it is assumed that their character is stationary in wide sense and ergodic. The correctness of such assumptions is confirmed by the research conducted by many research centres. Such an assumption requires tests on long distance which requires long measurement time. It may be assumed that mathematical condition of time approaching the infinity (T → ∞) is met. Most often the stationarity of the vibration signal in wider sense and its ergodicity is assessed with use of static signals by means of mean value and autocorrelation function. Also the square mean, probability density and the power spectral density are calculated. The calculated values are used for description of stochastic excitation that are the effect of the irregularities of road surface.

  1. Family climate for road safety: a new concept and measure.

    PubMed

    Taubman-Ben-Ari, Orit; Katz-Ben-Ami, Liat

    2013-05-01

    This research adapted the workplace concept of safety climate to the domain of safe driving, defining a new construct of "family climate for road safety". Four studies were conducted in Israel with the aim of developing and validating a multidimensional instrument to assess this construct among young drivers. Study 1 (n=632) focused on developing the Family Climate for Road Safety Scale (FCRSS), a self-report scale assessing the family climate by means of seven aspects of the parent-child relationship: Modeling, Feedback, Communication, Monitoring, Noncommitment, Messages, and Limits. Significant differences were found between young men and women on all factors. In addition, significant associations were found between the FCRSS factors on the one hand, and the reported frequency of risky driving and personal commitment to safety on the other. Studies 2-4 confirmed the factorial structure of the FCRSS and the reliability of its factors, adding to its criterion and convergent validity. Study 2 (n=178) yielded significant associations between the scale and young drivers' perception of their parents as involved, encouraging autonomy, and providing warmth; Study 3 (n=117) revealed significant associations between the scale and youngsters' reported proneness to take risks while driving, as well as significant associations between the factors and various dimensions of family functioning; and Study 4 (n=156) found associations between the FCRSS factors and both driving styles (risky, angry, anxious, careful) and family cohesion and adaptability. The discussion deals with the validity and utility of the concept of family climate for road safety and its measurement, addressing the practical implications for road safety.

  2. Family climate for road safety: a new concept and measure.

    PubMed

    Taubman-Ben-Ari, Orit; Katz-Ben-Ami, Liat

    2013-05-01

    This research adapted the workplace concept of safety climate to the domain of safe driving, defining a new construct of "family climate for road safety". Four studies were conducted in Israel with the aim of developing and validating a multidimensional instrument to assess this construct among young drivers. Study 1 (n=632) focused on developing the Family Climate for Road Safety Scale (FCRSS), a self-report scale assessing the family climate by means of seven aspects of the parent-child relationship: Modeling, Feedback, Communication, Monitoring, Noncommitment, Messages, and Limits. Significant differences were found between young men and women on all factors. In addition, significant associations were found between the FCRSS factors on the one hand, and the reported frequency of risky driving and personal commitment to safety on the other. Studies 2-4 confirmed the factorial structure of the FCRSS and the reliability of its factors, adding to its criterion and convergent validity. Study 2 (n=178) yielded significant associations between the scale and young drivers' perception of their parents as involved, encouraging autonomy, and providing warmth; Study 3 (n=117) revealed significant associations between the scale and youngsters' reported proneness to take risks while driving, as well as significant associations between the factors and various dimensions of family functioning; and Study 4 (n=156) found associations between the FCRSS factors and both driving styles (risky, angry, anxious, careful) and family cohesion and adaptability. The discussion deals with the validity and utility of the concept of family climate for road safety and its measurement, addressing the practical implications for road safety. PMID:23500935

  3. Measurement and dimension of road fatality in Brunei.

    PubMed

    Haque, Mohammed Ohidul

    2011-03-01

    In this article, we have investigated the pattern of road fatality in Brunei. It is seen from this analysis that road fatality in Brunei was one of the highest in the world in the early 1990s, but has been significantly reduced over the years, and is now one of the lowest in the world. Preliminary investigation shows that young male drivers are responsible for most road fatalities in Brunei. We have also fitted a linear regression model and found that road fatality is significantly positively related to people aged 18-24 years and new registered vehicles, both of which are expected to grow with the growth of population and economic development. Hence, road fatality in Brunei is also expected to grow unless additional effective road safety countermeasures are introduced and implemented to reduce road toll. Negative coefficient is observed for trend variable, indicating the reduction of road fatality due to the combined effects of improvements of vehicle safety, road design, medical facilities and road safety awareness among road user groups. However, short-term road fatality analysis based on monthly data indicates that the coefficient of the trend variable is positive, implying that in recent months road fatalities are increasing in Brunei, which is supported by media reports. We have compared Brunei's road fatality data with Australia, Singapore and Malaysia and found that Brunei's road fatality rate is lower than Singapore and Malaysia, but higher than Australia. This indicates that there are still opportunities to reduce road fatalities in Brunei if additional effective road safety strategies are implemented like in Australia without interfering in the economic and social development of Brunei.

  4. Statistical classification of road pavements using near field vehicle rolling noise measurements.

    PubMed

    Paulo, Joel Preto; Coelho, J L Bento; Figueiredo, Mário A T

    2010-10-01

    Low noise surfaces have been increasingly considered as a viable and cost-effective alternative to acoustical barriers. However, road planners and administrators frequently lack information on the correlation between the type of road surface and the resulting noise emission profile. To address this problem, a method to identify and classify different types of road pavements was developed, whereby near field road noise is analyzed using statistical learning methods. The vehicle rolling sound signal near the tires and close to the road surface was acquired by two microphones in a special arrangement which implements the Close-Proximity method. A set of features, characterizing the properties of the road pavement, was extracted from the corresponding sound profiles. A feature selection method was used to automatically select those that are most relevant in predicting the type of pavement, while reducing the computational cost. A set of different types of road pavement segments were tested and the performance of the classifier was evaluated. Results of pavement classification performed during a road journey are presented on a map, together with geographical data. This procedure leads to a considerable improvement in the quality of road pavement noise data, thereby increasing the accuracy of road traffic noise prediction models.

  5. On-road particle number measurements using a portable emission measurement system (PEMS)

    NASA Astrophysics Data System (ADS)

    Gallus, Jens; Kirchner, Ulf; Vogt, Rainer; Börensen, Christoph; Benter, Thorsten

    2016-01-01

    In this study the on-road particle number (PN) performance of a Euro-5 direct-injection (DI) gasoline passenger car was investigated. PN emissions were measured using the prototype of a portable emission measurement system (PEMS). PN PEMS correlations with chassis dynamometer tests show a good agreement with a chassis dynamometer set-up down to emissions in the range of 1·1010 #/km. Parallel on-line soot measurements by a photo acoustic soot sensor (PASS) were applied as independent measurement technique and indicate a good on-road performance for the PN-PEMS. PN-to-soot ratios were 1.3·1012 #/mg, which was comparable for both test cell and on-road measurements. During on-road trips different driving styles as well as different road types were investigated. Comparisons to the world harmonized light-duty test cycle (WLTC) 5.3 and to European field operational test (euroFOT) data indicate the PEMS trips to be representative for normal driving. Driving situations in varying traffic seem to be a major contributor to a high test-to-test variability of PN emissions. However, there is a trend to increasing PN emissions with more severe driving styles. A cold start effect is clearly visible for PN, especially at low ambient temperatures down to 8 °C.

  6. Factors affecting non-tailpipe aerosol particle emissions from paved roads: On-road measurements in Stockholm, Sweden

    NASA Astrophysics Data System (ADS)

    Hussein, Tareq; Johansson, Christer; Karlsson, Hans; Hansson, Hans-Christen

    A large fraction of urban PM 10 concentrations is due to non-exhaust traffic emissions. In this paper, a mobile measurement system has been used to quantify the relative importance of road particle emission and suspension of accumulated dust versus direct pavement wear, tire type (studded, friction, and summer), pavement type, and vehicle speed. Measurements were performed during May-September on selected roads with different pavements and traffic conditions in the Stockholm region. The highest particle mass concentrations were always observed behind the studded tire and the lowest were behind the summer tire; studded-to-summer ratios were 4.4-17.3 and studded-to-friction ratios were 2.0-6.4. This indicates that studded tires lead to higher emissions than friction and summer tires regardless to the asphalt type. By comparing with measurements in a road simulator, it could be estimated that the pavement wear due to the friction tires was 0.018-0.068 of the suspension of accumulated road dust. Likewise for studded tires road-wear was estimated to be 1.2-4.8 the suspension of accumulated dust. This indicates that wear due to friction tires is very small compared to the suspension of accumulated dust and that suspension due to studded tires may sometimes be as large as the wear of the road. But this will vary depending on, e.g. the amount of dust accumulated on the roads. An important dependence on vehicle speed was also observed. During May, the particle mass concentrations behind the studded tire at vehicle speed 100 km h -1 were about 10 times higher than that at 20 km h -1. The speed dependence was not so pronounced in September, which could be due to less accumulated dust on the roads. The particle number size distribution of the emissions due to road wear by studded tire was characterized by a clear increase in number concentrations of the coarse fraction of aerosol particles, with a geometric mean diameter between 3 and 5 μm. The size distribution of the

  7. SAGE II aerosol correlative observations - Profile measurements

    NASA Technical Reports Server (NTRS)

    Osborn, M. T.; Rosen, J. M.; Mccormick, M. P.; Wang, Pi-Huan; Livinfston, J. M.

    1989-01-01

    Profiles of the aerosol extinction measurements from the Stratospheric Aerosol and Gas Experiment (SAGE) II are compared with profiles from five correlative experiments between November 1984 and July 1986. The correlative profiles were derived from six-channel dustsonde measurements and two-wavelength lidar backscatter data. The correlation between the dustsonde- and lidar-derived measurements and the SAGE II data is good, validating the SAGE II lower stratospheric aerosol extinction measurements.

  8. On-road traffic emissions of polycyclic aromatic hydrocarbons and their oxy- and nitro- derivative compounds measured in road tunnel environments.

    PubMed

    Keyte, Ian J; Albinet, Alexandre; Harrison, Roy M

    2016-10-01

    Vehicular emissions are a key source of polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs) and their oxygenated (OPAH) and nitrated (NPAH) derivatives, in the urban environment. Road tunnels are a useful environment for the characterisation of on-road vehicular emissions, providing a realistic traffic fleet and a lack of direct sunlight, chemical reactivity and non-traffic sources. In the present investigation the concentrations of selected PAHs, OPAHs and NPAHs have been measured in the Parc des Princes Tunnel in Paris (PdPT, France), and at the Queensway Road Tunnel and an urban background site in Birmingham (QT, U.K). A higher proportion of semi-volatile (3-4 ring) PAH, OPAH and NPAH compounds are associated with the particulate phase compared with samples from the ambient environment. A large (~85%) decline in total PAH concentrations is observed between 1992 and 2012 measurements in QT. This is attributed primarily to the introduction of catalytic converters in the U.K as well as increasingly stringent EU vehicle emissions legislation. In contrast, NPAH concentrations measured in 2012 are similar to those measured in 1996. This observation, in addition to an increased proportion of (Phe+Flt+Pyr) in the observed PAH burden in the tunnel, is attributed to the increased number of diesel passenger vehicles in the U.K during this period. Except for OPAHs, comparable PAH and NPAH concentrations are observed in both investigated tunnels (QT and PdP). Significant differences are shown for specific substances between PAC chemical profiles in relation with the national traffic fleet differences (33% diesel passenger cars in U.K. vs 69% in France and up to 80% taking into account all vehicle categories). The dominating and sole contribution of 1-Nitropyrene observed in the PdPT NPAH profile strengthens the promising use of this compound as a diesel exhaust marker for PM source apportionment studies. PMID:27312273

  9. On-road traffic emissions of polycyclic aromatic hydrocarbons and their oxy- and nitro- derivative compounds measured in road tunnel environments.

    PubMed

    Keyte, Ian J; Albinet, Alexandre; Harrison, Roy M

    2016-10-01

    Vehicular emissions are a key source of polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs) and their oxygenated (OPAH) and nitrated (NPAH) derivatives, in the urban environment. Road tunnels are a useful environment for the characterisation of on-road vehicular emissions, providing a realistic traffic fleet and a lack of direct sunlight, chemical reactivity and non-traffic sources. In the present investigation the concentrations of selected PAHs, OPAHs and NPAHs have been measured in the Parc des Princes Tunnel in Paris (PdPT, France), and at the Queensway Road Tunnel and an urban background site in Birmingham (QT, U.K). A higher proportion of semi-volatile (3-4 ring) PAH, OPAH and NPAH compounds are associated with the particulate phase compared with samples from the ambient environment. A large (~85%) decline in total PAH concentrations is observed between 1992 and 2012 measurements in QT. This is attributed primarily to the introduction of catalytic converters in the U.K as well as increasingly stringent EU vehicle emissions legislation. In contrast, NPAH concentrations measured in 2012 are similar to those measured in 1996. This observation, in addition to an increased proportion of (Phe+Flt+Pyr) in the observed PAH burden in the tunnel, is attributed to the increased number of diesel passenger vehicles in the U.K during this period. Except for OPAHs, comparable PAH and NPAH concentrations are observed in both investigated tunnels (QT and PdP). Significant differences are shown for specific substances between PAC chemical profiles in relation with the national traffic fleet differences (33% diesel passenger cars in U.K. vs 69% in France and up to 80% taking into account all vehicle categories). The dominating and sole contribution of 1-Nitropyrene observed in the PdPT NPAH profile strengthens the promising use of this compound as a diesel exhaust marker for PM source apportionment studies.

  10. Safety effects of low-cost engineering measures. An observational study in a Portuguese multilane road.

    PubMed

    Vieira Gomes, Sandra; Cardoso, João Lourenço

    2012-09-01

    Single carriageway multilane roads are not, in general, a very safe type of road, mainly because of the high number of seriously injured victims in head-on collisions, when compared with dual carriageway multilane roads, with a median barrier. In this paper the results of a study on the effect of the application of several low cost engineering measures, aimed at road infrastructure correction and road safety improvement on a multilane road (EN6), are presented. The study was developed by the National Laboratory of Civil Engineering (LNEC) for the Portuguese Road Administration and involved a comparison of selected aspects of motorized traffic behaviour (traffic volumes and speeds) measured in several sections of EN6, as well as monitoring of road safety developments in the same road. The applied low cost engineering measures allowed a reduction of 10% in the expected annual number of personal injury accidents and a 70% decrease in the expected annual number of head-on collisions; the expected annual frequency of accidents involving killed and seriously injured persons was reduced by 26%.

  11. Trends in ozone profile measurements

    NASA Technical Reports Server (NTRS)

    Johnston, H.; Aikin, A.; Barnes, R.; Chandra, S.; Cunnold, D.; Deluisi, J.; Gille, J. C.; Hudson, R.; Mccormick, M. P.; Mcmaster, L.

    1989-01-01

    From an examination of the agreements and differences between different satellite instruments, it is difficult to believe that existing satellite instruments determine upper stratospheric ozone much better than 4 pct.; by extension, it probably would require at least a 4 pct. change to be reliably detected as a change. The best estimates of the vertical profiles of ozone change in the upper stratosphere between 1979 and 1986 are judged to be those given by the two SAGE satellite instruments. SAGE-2 minus SAGE-1 gives a much lower ozone reduction than that given by the archived Solar Backscatter UV data. The average SAGE profiles of ozone changes between 20 and 50 degs north and between 20 and 50 degs south are given. The SAGE-1 and SAGE-2 comparison gives an ozone reduction of about 4 pct. at 25 km over temperate latitudes. Five ground based Umkehr stations between 36 and 52 degs north, corrected for the effects of volcanic aerosols, report an ozone reduction between 1979 and 1987 at Umkehr layer 8 of 9 + or - 5 pct. The central estimate of upper stratospheric ozone reduction given by SAGE at 40 km is less than the central value estimated by the Umkehr method at layer 8.

  12. Compliant transducer measures artery profile

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Culler, V. H.; Crawford, D. W.; Spears, J. R.

    1981-01-01

    Instrument consisting of compliant fingers with attached semiconductor pickups measures inside contours of narrow vessels. Instrument, originally designed to monitor human arteries, is drawn through vessel to allow finges to follow contours. Lead wires transmit electrical signals to external processing equipment.

  13. On the Road, Measuring the Miles per Applicant

    ERIC Educational Resources Information Center

    Hoover, Eric

    2008-01-01

    Most people in admissions have a road story. There are tales of wrong turns, lost suitcases, and days when they were just well-dressed ghosts, walking in and out of high schools where no students came to see them. These are the trials of admissions representatives who leave their campuses for several weeks each fall. They trek near and far to meet…

  14. On-Road Measurement of Vehichle VOC Emission Measurements During the 2003 Mexico City Metropolitan Area Field Campaign

    NASA Astrophysics Data System (ADS)

    Knighton, W. B.; Rogers, T.; Grimsrud, E.; Herndon, S.; Allwine, E.; Lamb, B.; Velasco, E.; Westberg, H.

    2004-12-01

    In the spring of 2003 (April 1-May 5), a multinational team of experts conducted an intensive, five-week field campaign in the Mexico City Metropolitan Area (MCMA). The overall goal of this effort was to contribute to the understanding of the air quality problem in megacities. As part of the campaign the Aerodyne Mobile Laboratory was equipped with state-of-the-art analytical instruments and deployed for measuring a variety of vehicle emissions in real time including CO2, NO2, NH3, HCHO, VOC's and volatile (at 600 °C) aerosol. The on-road measurement of vehicle VOC emissions were performed using a commercial version of the IONICON PTR-MS modified to operate onboard the mobile lab platform. A summary of the PTR-MS results from these and supporting laboratory experiments will be presented and discussed. In particular, selected chase events will be presented to illustrate the utility of the PTR-MS technique for characterizing vehicle VOC emission profiles in real time. VOC emission profiles for different vehicle engine types which include gasoline, diesel and compressed natural gas will be discussed and compared to the measurements from other high time response instruments deployed on the Aerodyne mobile van.

  15. The PM10 fraction of road dust in the UK and India: Characterization, source profiles and oxidative potential.

    PubMed

    Pant, Pallavi; Baker, Stephen J; Shukla, Anuradha; Maikawa, Caitlin; Godri Pollitt, Krystal J; Harrison, Roy M

    2015-10-15

    Most studies of road dust composition have sampled a very wide range of particle sizes, but from the perspective of respiratory exposure to resuspended dusts, it is the PM10 fraction which is of most importance. The PM10 fraction of road dust samples was collected at two sites in Birmingham, UK (major highway and road tunnel) and one site in New Delhi, India. Dust loadings were found to be much higher for New Delhi compared to Birmingham, while concentrations of several species were much higher in the case of Birmingham. Detailed chemical source profiles were prepared for both cities and previously generated empirical factors for source attribution to brake wear, tyre wear, and crustal dust were successfully applied to the UK sites. However, 100% of the mass for the Indian site could not be accounted for using these factors. This study highlights the need for generation of local empirical estimation factors for non-exhaust vehicle emissions. A limited number of bulk road dust and brake pad samples were also characterized. Oxidative potential (OP) was also determined for a limited number of PM10 and bulk road dust samples, and Cu was found to be a factor significantly associated with OP in PM10 and bulk road dust. PMID:26033216

  16. Large Dynamic Range Beam Profile Measurements

    SciTech Connect

    A. P. Freyberger

    2005-06-01

    Large dynamic range (Peak/Noise >10{sup 5}) beam profile measurements are routinely performed in the Hall-B beamline at Jefferson Lab. These measurements are made with a 1 to 10nA electron beam current with energies between 1 to 6 GeV. The electron beam scatters off of a thin W or Fe wire and the scattered particle/shower is detected via scintillation or Cerenkov light several meters downstream of the wire. This report describes results on increasing the dynamic range by using multiple wires of varying diameters. Profile measurements with this large dynamic range are of use for accelerators with very stored energy (e.g. energy recovering linacs [ERL]) where small beam loss represents a significant amount of beam power. Results on measuring the transverse profile with large dynamic range during the CEBAF energy recovery experiment is also presented.

  17. GPR measurements and estimation for road subgrade damage caused by neighboring train vibration load

    NASA Astrophysics Data System (ADS)

    Zhao, Yonghui; Lu, Gang; Ge, Shuangcheng

    2015-04-01

    Generally, road can be simplified as a three-layer structure, including subgrade, subbase and pavement. Subgrade is the native material underneath a constructed road. It is commonly compacted before the road construction, and sometimes stabilized by the addition of asphalt, lime or other modifiers. As the mainly supporting structure, subgrade damage would lead in pavement settlement, displacement and crack. Assessment and monitoring of the subgrade condition currently involves trial pitting and subgrade sampling. However there is a practical limit on spatial density at which trail pits and cores can be taken. Ground penetrating radar (GPR) has been widely used to characterize highway pavement profiling, concrete structure inspection and railroad track ballast estimation. GPR can improve the economics of road maintenance. Long-term train vibration load might seriously influence the stability of the subgrade of neighboring road. Pavement settlement and obvious cracks have been found at a municipal road cross-under a railway with culvert box method. GPR test was conducted to estimate the subgrade and soil within 2.0 m depth for the further road maintenance. Two survey lines were designed in each lane, and total 12 GPR sections have been implemented. Considering both the penetrating range and the resolution, a antenna with a 500 MHz central frequency was chosen for on-site GPR data collection. For data acquisition, we used the default operating environment and scanning parameters for the RAMAC system: 60kHz transmission rate, 50 ns time window, 1024 samples per scan and 0.1 m step-size. Continuous operation was used; the antenna was placed on the road surface and slowly moved along the road. The strong surrounding disturbance related to railroad and attachments, might decrease the reliability of interpretation results. Some routine process methods (including the background removing, filtering) have been applied to suppress the background noise. Additionally, attribute

  18. Characteristics of volatile organic compounds emission profiles from hot road bitumens.

    PubMed

    Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

    2014-07-01

    A procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography-mass spectrometry (GC-MS). The studies revealed that so-called vacuum residue, which is the main component of the charge, contains variable VOC concentrations, from trace to relatively high ones, depending on the extent of thermal cracking in the boiler of the vacuum distillation column. The VOC content in the oxidation product, so-called oxidized paving bitumen, is similarly varied. There are major differences in VOC emission profiles between vacuum residue and oxidized bitumens undergoing thermal cracking. The VOC content in oxidized bitumens, which did not undergo thermal cracking, increases with the degree of oxidation of bitumens. The studies revealed that the total VOC content increases from about 120 ppm for the raw vacuum residue to about 1900 ppm for so-called bitumen 35/50. The amount of volatile sulfur compounds (VSCs) in the volatile fraction of fumes of oxidized bitumens increases with the degree of oxidation of bitumen and constitutes from 0.34% to 3.66% (w/w). The contribution of volatile nitrogen compounds (VNCs) to total VOC content remains constant for the investigated types of bitumens (from 0.16 to 0.28% (w/w) of total VOCs). The results of these studies can also find use during the selection of appropriate bitumen additives to minimize their malodorousness. The obtained data append the existing knowledge on VOC emission from oxidized bitumens. They should be included in reports on the environmental impact of facilities in which hot bitumen binders are used. PMID:24875867

  19. Advanced interferometric profile measurements through refractive media

    SciTech Connect

    Koev, Stephan T.; Ghodssi, Reza

    2008-09-15

    Optical profilers are valuable tools for the characterization of microelectromechanical systems (MEMSs). They use phase sifting interferometry (PSI) or vertical scanning interferometry to measure the topography of microscale structures with nanometer resolution. However, for many emerging MEMS applications, the sample needs to be imaged while placed in a liquid or in a package with a glass window. The increased refractive index of the transparent medium degrades the interference image contrast and prevents any measurement of the sample. We report on the modification of a Veeco NT1100 optical profiler to enable PSI measurements through refractive media. This approach can be applied to any other optical profiler with PSI capability. The modification consists in replacing the original illumination source with a custom-built narrow linewidth source, which increases the coherence length of the light and the contrast of the interference image. We present measurements taken with the modified configuration on samples covered with 3 mm water or 500 {mu}m glass, and we compare them to measurements of uncovered samples. We show that the measurement precision is only slightly reduced by the water and glass, and that it is still sufficiently high for typical MEMS applications. The described method can be readily used for measuring through other types and thicknesses of refractive materials.

  20. Road surface texture and skid resistance

    NASA Astrophysics Data System (ADS)

    Do, Minh-Tan; Cerezo, Veronique

    2015-12-01

    This paper deals with the relationship between road surface texture and skid resistance. Mechanisms underlying the tire/wet road friction are first described. Definitions of road surface irregularities scales are given. The rest of the paper is then focused on the macrotexture and microtexture scales and their respective roles in what happens at the tire/road interface. Existing methods to measure and characterize the road surface texture are presented. On the one hand, problems encountered when using sensors developed for machined surfaces for the measurement of road surface profiles or cartographies are discussed. On the other hand, potential improvements when applying characterization methods developed for machined surfaces to road surfaces are highlighted. The paper presents finally modeling approaches to calculate friction forces from road surface texture. The generalized form of the models is presented from which terms related respectively to the macrotexture and the microtexture are identified. Approaches used to calculate these terms, integrating eventually other variables, are presented.

  1. On-road remote sensing of liquefied petroleum gas (LPG) vehicle emissions measurement and emission factors estimation

    NASA Astrophysics Data System (ADS)

    Ning, Z.; Chan, T. L.

    In the present study, the real-world on-road liquefied petroleum gas (LPG) vehicle/taxi emissions of carbon monoxide (CO), hydrocarbon (HC) and nitric oxide (NO) were investigated. A regression analysis approach based on the measured LPG vehicle emission data was also used to estimate the on-road LPG vehicle emission factors of CO, HC and NO with respect to the effects of instantaneous vehicle speed and acceleration/deceleration profiles for local urban driving patterns. The results show that the LPG vehicle model years and driving patterns have a strong correlation to their emission factors. A unique correlation of LPG vehicle emission factors (i.e., g km -1 and g l -1) on different model years for urban driving patterns has been established. Finally, a comparison was made between the average LPG, and petrol [Chan, T.L., Ning, Z., Leung, C.W., Cheung, C.S., Hung, W.T., Dong, G., 2004. On-road remote sensing of petrol vehicle emissions measurement and emission factors estimation in Hong Kong. Atmospheric Environment 38, 2055-2066 and 3541] and diesel [Chan, T.L., Ning, Z., 2005. On-road remote sensing of diesel vehicle emissions measurement and emission factors estimation in Hong Kong. Atmospheric Environment 39, 6843-6856] vehicle emission factors. It has shown that the introduction of the replacement of diesel taxis to LPG taxis has alleviated effectively the urban street air pollution. However, it has demonstrated that proper maintenance on the aged LPG taxis should also be taken into consideration.

  2. Runoff and windblown vehicle spray from road surfaces, risks and measures for soil and water.

    PubMed

    Schipper, P N M; Comans, R N J; Dijkstra, J J; Vergouwen, L

    2007-01-01

    Soil and surface water along roads are exposed to pollution from motorways. The main pollutants are polycyclic aromatic hydrocarbons (PAH), mineral oil, heavy metals and salt. These pollutants originate from vehicles (fuel, wires, leakage), wear and degradation of road surfaces and road furniture (i.e. crash barriers) and the application of de-icing salts. Runoff, vehicle spray and dry deposition disperse these contaminants into the soft shoulder (verges) of the roads and surface water to a measurable distance of about 50 up to more then 150 m from the road. Despite many monitoring programs, little is known about the risks of this diffuse pollution for soil and water quality and the geochemical and physical factors which determine these risks. Also little is known about the effects of possible measures. Therefore, extensive research has been carried out at two local motorways. Specific measurements on runoff, vehicle spray and effects of measures have been carried out for one year (13 months). This resulted in several new insights. The pollutants appear to adsorb effectively to natural soils. In vulnerable areas groundwater can be protected by adjusting the policy to removing the contaminated upper topsoil of the verges. Discharges of runoff into local surface water are not recommended.

  3. On-road remote sensing of petrol vehicle emissions measurement and emission factors estimation in Hong Kong

    NASA Astrophysics Data System (ADS)

    Chan, T. L.; Ning, Z.; Leung, C. W.; Cheung, C. S.; Hung, W. T.; Dong, G.

    In the present study, the real world on-road petrol vehicle emissions of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO) were investigated at nine sites in Hong Kong. A regression analysis approach based on the measured petrol vehicle emission data was also used to estimate the on-road petrol vehicle emission factors of CO, HC and NO with respect to the effects of instantaneous vehicle speed and acceleration/deceleration profiles for local urban driving patterns. The results show that the petrol vehicle model years, engine sizes and driving patterns have a strong correlation on their emission factors. A comparison of average petrol vehicle emission factors in different engine sizes and European vehicle emission standards was also presented. The deviation of the average emission factors of aggregate petrol vehicle reflects on the variability of local road condition, vehicle traffic fleet and volume, driving pattern, fuel composition and ambient condition etc. Finally, a unique database of the correlation of petrol vehicle emission factors on different model years and engine sizes for urban driving patterns in Hong Kong was established.

  4. On-road remote sensing of diesel vehicle emissions measurement and emission factors estimation in Hong Kong

    NASA Astrophysics Data System (ADS)

    Chan, T. L.; Ning, Z.

    In the present study, the real world on-road diesel vehicle emissions of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO) were investigated at nine sites in Hong Kong. A regression analysis approach based on the measured vehicle emission data was used to estimate the on-road diesel vehicle emission factors of CO, HC and NO with respect to the effects of instantaneous vehicle speed and acceleration/deceleration profiles for local urban driving patterns. The results show that the diesel vehicle model years, engine sizes, vehicle types and driving patterns have a strong correlation with their emission factors. A comparison was made between the average diesel and petrol vehicle emissions factors in Hong Kong. The deviation of the average emission factors of aggregate diesel vehicles reflects the variability of local road condition, vehicle traffic fleet and volume, driving pattern, fuel composition and ambient condition etc. Finally, a unique database of the correlation of diesel vehicle emission factors (i.e., g km -1 and g l -1) on different model years and vehicle types for urban driving patterns in Hong Kong was established.

  5. LASER PROFILE MEASUREMENTS OF AN H BEAM.

    SciTech Connect

    CONNOLLY,R.; CAMERON,P.; CUPOLO,J.; GRAU,M.; KESSELMAN,M.; LIAW,C.J.; SIKORA,R.

    2001-06-18

    A non-intercepting beam profile monitor for He beams is being developed at Brookhaven National Lab. An H{sup {minus}} ion has a first ionization potential of 0.75eV. Electrons can be removed from an H{sup {minus}} beam by passing light from a near-infrared laser through it. Experiments have been performed on the BNL linac to measure the transverse profile of a 750keV beam by using a Nd:YAG laser to photoneutralize narrow slices of the beam. The laser beam is scanned across the ion beam neutralizing the portion of the beam struck by the laser. The electrons are removed from the ion beam and the beam current notch is measured.

  6. On-road Emissions of Reactive Nitrogen through In-situ, Mobile Measurements

    NASA Astrophysics Data System (ADS)

    Sun, K.; Tao, L.; Pan, D.; Golston, L.; Miller, D. J.; Zondlo, M. A.

    2014-12-01

    Ammonia (NH3) is a key precursor to atmospheric fine particulate matter (PM2.5), with strong implications for regional air quality and global climate change. Existing atmospheric measurements suggest that urban traffic may provide significant amount of NH3. NH3 emissions in urban areas may cause greater impact on air quality and human health, because other aerosol tracers, like NO and NO2, are emitted by similar on-road sources. However, the on-road NH3 emission inventories are subject to significant uncertainties. A mobile platform is developed by mounting multiple portable (total power ~ 100 W, weight ~ 25 kg), high-resolution (10 Hz), open-path sensors on top of a passenger car. On-road NH3 emissions are quantified in the real-world driving conditions by synchronized NH3, CO, and CO2 measurements. The mobile platform has covered over 16,000 km in the US and China since 2013. The total on-road sampling time is over 300 hours. Major US metropolitan areas that have been sampled include LA, SF, Houston, Philadelphia, and Denver. Three Chinese megacities (Beijing, Baoding, and Shijiazhuang) were sampled in both 2013 and 2014. The average emission factors (grams of NH3 emitted per kilogram of fuel) range from 0.3 to 0.5 g/kg. Different methodologies were compared, including on-road emission ratios, tunnel measurements, and city-scale gradient measurements. These methodologies yielded the same emission factor for Houston (0.4±0.05 g/kg) within the sampling uncertainties and showed that multiple approaches are consistent with one another. The observed NH3 emission ratios indicate that National Emisison Inventory (NEI) underestimates on-road NH3 emissions by up to 50% in some major urban areas. On-road NH3 emission factors show higher values in both stop-and-go driving conditions and freeway speeds with a minimum near 70 km/h. This is consistent with another observation that the emission factors in urban traffic are generally larger than suburban traffic. Road gradient

  7. Measuring Algorithm for the Distance to a Preceding Vehicle on Curve Road Using On-Board Monocular Camera

    NASA Astrophysics Data System (ADS)

    Yu, Guizhen; Zhou, Bin; Wang, Yunpeng; Wun, Xinkai; Wang, Pengcheng

    2015-12-01

    Due to more severe challenges of traffic safety problems, the Advanced Driver Assistance Systems (ADAS) has received widespread attention. Measuring the distance to a preceding vehicle is important for ADAS. However, the existing algorithm focuses more on straight road sections than on curve measurements. In this paper, we present a novel measuring algorithm for the distance to a preceding vehicle on a curve road using on-board monocular camera. Firstly, the characteristics of driving on the curve road is analyzed and the recognition of the preceding vehicle road area is proposed. Then, the vehicle detection and distance measuring algorithms are investigated. We have verified these algorithms on real road driving. The experimental results show that this method proposed in the paper can detect the preceding vehicle on curve roads and accurately calculate the longitudinal distance and horizontal distance to the preceding vehicle.

  8. A quantitative approach to measure road network information based on edge diversity

    NASA Astrophysics Data System (ADS)

    Wu, Xun; Zhang, Hong; Lan, Tian; Cao, Weiwei; He, Jing

    2015-12-01

    The measure of map information has been one of the key issues in assessing cartographic quality and map generalization algorithms. It is also important for developing efficient approaches to transfer geospatial information. Road network is the most common linear object in real world. Approximately describe road network information will benefit road map generalization, navigation map production and urban planning. Most of current approaches focused on node diversities and supposed that all the edges are the same, which is inconsistent to real-life condition, and thus show limitations in measuring network information. As real-life traffic flow are directed and of different quantities, the original undirected vector road map was first converted to a directed topographic connectivity map. Then in consideration of preferential attachment in complex network study and rich-club phenomenon in social network, the from and to weights of each edge are assigned. The from weight of a given edge is defined as the connectivity of its end node to the sum of the connectivities of all the neighbors of the from nodes of the edge. After getting the from and to weights of each edge, edge information, node information and the whole network structure information entropies could be obtained based on information theory. The approach has been applied to several 1 square mile road network samples. Results show that information entropies based on edge diversities could successfully describe the structural differences of road networks. This approach is a complementarity to current map information measurements, and can be extended to measure other kinds of geographical objects.

  9. Experimental study designs to improve the evaluation of road mitigation measures for wildlife.

    PubMed

    Rytwinski, Trina; van der Ree, Rodney; Cunnington, Glenn M; Fahrig, Lenore; Findlay, C Scott; Houlahan, Jeff; Jaeger, Jochen A G; Soanes, Kylie; van der Grift, Edgar A

    2015-05-01

    An experimental approach to road mitigation that maximizes inferential power is essential to ensure that mitigation is both ecologically-effective and cost-effective. Here, we set out the need for and standards of using an experimental approach to road mitigation, in order to improve knowledge of the influence of mitigation measures on wildlife populations. We point out two key areas that need to be considered when conducting mitigation experiments. First, researchers need to get involved at the earliest stage of the road or mitigation project to ensure the necessary planning and funds are available for conducting a high quality experiment. Second, experimentation will generate new knowledge about the parameters that influence mitigation effectiveness, which ultimately allows better prediction for future road mitigation projects. We identify seven key questions about mitigation structures (i.e., wildlife crossing structures and fencing) that remain largely or entirely unanswered at the population-level: (1) Does a given crossing structure work? What type and size of crossing structures should we use? (2) How many crossing structures should we build? (3) Is it more effective to install a small number of large-sized crossing structures or a large number of small-sized crossing structures? (4) How much barrier fencing is needed for a given length of road? (5) Do we need funnel fencing to lead animals to crossing structures, and how long does such fencing have to be? (6) How should we manage/manipulate the environment in the area around the crossing structures and fencing? (7) Where should we place crossing structures and barrier fencing? We provide experimental approaches to answering each of them using example Before-After-Control-Impact (BACI) study designs for two stages in the road/mitigation project where researchers may become involved: (1) at the beginning of a road/mitigation project, and (2) after the mitigation has been constructed; highlighting real case

  10. Modelling road dust emission abatement measures using the NORTRIP model: Vehicle speed and studded tyre reduction

    NASA Astrophysics Data System (ADS)

    Norman, M.; Sundvor, I.; Denby, B. R.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.

    2016-06-01

    Road dust emissions in Nordic countries still remain a significant contributor to PM10 concentrations mainly due to the use of studded tyres. A number of measures have been introduced in these countries in order to reduce road dust emissions. These include speed reductions, reductions in studded tyre use, dust binding and road cleaning. Implementation of such measures can be costly and some confidence in the impact of the measures is required to weigh the costs against the benefits. Modelling tools are thus required that can predict the impact of these measures. In this paper the NORTRIP road dust emission model is used to simulate real world abatement measures that have been carried out in Oslo and Stockholm. In Oslo both vehicle speed and studded tyre share reductions occurred over a period from 2004 to 2006 on a major arterial road, RV4. In Stockholm a studded tyre ban on Hornsgatan in 2010 saw a significant reduction in studded tyre share together with a reduction in traffic volume. The model is found to correctly simulate the impact of these measures on the PM10 concentrations when compared to available kerbside measurement data. Importantly meteorology can have a significant impact on the concentrations through both surface and dispersion conditions. The first year after the implementation of the speed reduction on RV4 was much drier than the previous year, resulting in higher mean concentrations than expected. The following year was much wetter with significant rain and snow fall leading to wet or frozen road surfaces for 83% of the four month study period. This significantly reduced the net PM10 concentrations, by 58%, compared to the expected values if meteorological conditions had been similar to the previous years. In the years following the studded tyre ban on Hornsgatan road wear production through studded tyres decreased by 72%, due to a combination of reduced traffic volume and reduced studded tyre share. However, after accounting for exhaust

  11. Awareness and practice of road safety measures among undergraduate medical students in a South Indian state.

    PubMed

    Kulkarni, Vaman; Kanchan, Tanuj; Palanivel, C; Papanna, M K; Kumar, Nithin; Unnikrishnan, B

    2013-05-01

    The UN general assembly has declared 2011-2020 as the "Decade of Action for Road Safety". The declaration holds significance because road traffic accidents (RTAs) have become a major cause of morbidity and mortality, especially among the adults and middle aged individuals who constitute economically most productive age groups of society. The importance of knowledge and practice of road safety measures needs to be emphasized in the prevention of RTAs. The present study is aimed to assess the knowledge and practice of road safety measures among the students of a medical college in coastal, South India. A total of 260 medical students were included in this cross-sectional study. A semi-structured questionnaire was used to collect the relevant information from the participants. The data collected was analyzed using SPSS version 11.5. Out of the 260 participants, 149 (57.3%) were females and 111 (42.7%) were males. The overall awareness on road safety measures was slightly higher among females (20.6%) than males (19.9%). The participants had significantly low awareness with regard to alcohol and driving (4.2%), use of seat belts (20%) and use of mobile phones without hands free device (6.1%). The participants had a better knowledge about traffic signs and more than half of them identified all the signs correctly. With regard to the road safety practices, 25% were involved in drunken driving in the past one year. The practice of using mobile phones with hands free devices while driving was admitted by 20% of them. Nearly two-third participants (68%) admitted to have crossed speed limits on multiple occasions. Observations of the study emphasize on the need to generate awareness among medical students through training and IEC activities to curb the epidemic of RTAs.

  12. HEAVY DUTY DIESEL FINE PARTICULATE MATTER EMISSIONS: DEVELOPMENT AND APPLICATION OF ON-ROAD MEASUREMENT CAPABILITIES

    EPA Science Inventory

    The report discusses EPA's On-Road Diesel Emissions Characterization Facility, which has been collecting real-world gaseous emissions data for the past 6 years. It has recently undergone extensive modifications to enhance its particulate matter (PM) measurement capabilities, with...

  13. Near-road measurements for nitrogen dioxide and its association with traffic exposure zones

    EPA Science Inventory

    Near-road measurements for nitrogen dioxide (NO2) using passive air samplers were collected weekly in traffic exposure zones (TEZs) in the Research Triangle area of North Carolina (USA) during Fall 2014. Land use regression (LUR) analysis and pairwise comparisons of T...

  14. Comparison of modeled traffic exposure zones using on-road air pollution measurements

    EPA Science Inventory

    Modeled traffic data were used to develop traffic exposure zones (TEZs) such as traffic delay, high volume, and transit routes in the Research Triangle area of North Carolina (USA). On-road air pollution measurements of nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxid...

  15. NEAR ROAD NITRIC OXIDE AND HYDROCARBON MEASUREMENTS WITH DUV-DOAS

    EPA Science Inventory

    As part of the overall EPA effort to increase understanding of the distribution of air pollutants in near road environments, optical remote sensing techniques developed for area source measurement are being used to assess mobile source emissions and dispersion from roadway segmen...

  16. BOREAS RSS-17 Dielectric Constant Profile Measurements

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); McDonald, Kyle C.; Zimmerman, Reiner; Way, JoBea

    2000-01-01

    The BOREAS RSS-17 team acquired and analyzed imaging radar data from the ESA's ERS-1 over a complete annual cycle at the BOREAS sites in Canada in 1994 to detect shifts in radar backscatter related to varying environmental conditions. This data set consists of dielectric constant profile measurements from selected trees at various BOREAS flux tower sites. The relative dielectric constant was measured at C-band (frequency = 5 GHz) as a function of depth into the trunk of three trees at each site, Measurements were made during April 1994 with an Applied Microwave Corporation field PDP fitted with a 0.358-cm (0.141-inch) diameter coaxial probe tip. The data are available in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  17. Investigation of the impact of low cost traffic engineering measures on road safety in urban areas.

    PubMed

    Yannis, George; Kondyli, Alexandra; Georgopoulou, Xenia

    2014-01-01

    This paper investigates the impact of low cost traffic engineering measures (LCTEMs) on the improvement of road safety in urban areas. A number of such measures were considered, such as speed humps, woonerfs, raised intersections and other traffic calming measures, which have been implemented on one-way, one-lane roads in the Municipality of Neo Psychiko in the Greater Athens Area. Data were analysed using the before-and-after safety analysis methodology with large control group. The selected control group comprised of two Municipalities in the Athens Greater Area, which present similar road network and land use characteristics with the area considered. The application of the methodology showed that the total number of crashes presented a statistically significant reduction, which can be possibly attributed to the introduction of LCTEMs. This reduction concerns passenger cars and single-vehicle crashes and is possibly due to the behavioural improvement of drivers of 25 years old or more. The results of this research are very useful for the identification of the appropriate low cost traffic engineering countermeasures for road safety problems in urban areas.

  18. Vertical profile measurements of lower troposphere ionisation

    NASA Astrophysics Data System (ADS)

    Harrison, R. G.; Nicoll, K. A.; Aplin, K. L.

    2014-11-01

    Vertical soundings of the atmospheric ion production rate have been obtained from Geiger counters integrated with conventional meteorological radiosondes. In launches made from Reading (UK) during 2013-2014, the Regener-Pfotzer ionisation maximum was at an altitude equivalent to a pressure of (63.1±2.4) hPa, or, expressed in terms of the local air density, (0.101±0.005) kg m-3. The measured ionisation profiles have been evaluated against the Usoskin-Kovaltsov model and, separately, surface neutron monitor data from Oulu. Model ionisation rates agree well with the observed cosmic ray ionisation below 20 km altitude. Above 10 km, the measured ionisation rates also correlate well with simultaneous neutron monitor data, although, consistently with previous work, measured variability at the ionisation maximum is greater than that found by the neutron monitor. However, in the lower atmosphere (below 5 km altitude), agreement between the measurements and simultaneous neutron monitor data is poor. For studies of transient lower atmosphere phenomena associated with cosmic ray ionisation, this indicates the need for in situ ionisation measurements and improved lower atmosphere parameterisations.

  19. Characterizing a porous road pavement using surface impedance measurement: a guided numerical inversion procedure.

    PubMed

    Benoit, Gaëlle; Heinkélé, Christophe; Gourdon, Emmanuel

    2013-12-01

    This paper deals with a numerical procedure to identify the acoustical parameters of road pavement from surface impedance measurements. This procedure comprises three steps. First, a suitable equivalent fluid model for the acoustical properties porous media is chosen, the variation ranges for the model parameters are set, and a sensitivity analysis for this model is performed. Second, this model is used in the parameter inversion process, which is performed with simulated annealing in a selected frequency range. Third, the sensitivity analysis and inversion process are repeated to estimate each parameter in turn. This approach is tested on data obtained for porous bituminous concrete and using the Zwikker and Kosten equivalent fluid model. This work provides a good foundation for the development of non-destructive in situ methods for the acoustical characterization of road pavements.

  20. iPOP goes the world: integrated Personalized Omics Profiling and the road towards improved health care

    PubMed Central

    Li-Pook-Than, Jennifer; Snyder, Michael

    2014-01-01

    The health of an individual depends upon their DNA as well as environmental factors (environome or exposome). It is expected that although the genome is the blueprint of an individual, its analysis with that of the other omes, such as the DNA methylome, the transcriptome, proteome, as well as metabolome will further provide a dynamic assessment of the physiology and health state of an individual. This review will help to categorize the current progress of omics analyses, and how omics integration can be used for medical research. We believe that integrative Personal Omics Profiling (iPOP) is a stepping stone to a new road to personalized health care and may improve 1) Disease risk assessment, 2) Accuracy of diagnosis, 3) Disease monitoring, 4) Targeted treatments and 5) Understanding the biological processes of disease states for their prevention. PMID:23706632

  1. Characterization of non-exhaust coarse and fine particles from on-road driving and laboratory measurements.

    PubMed

    Kwak, Ji-hyun; Kim, Hongsuk; Lee, Janghee; Lee, Seokhwan

    2013-08-01

    We investigated the physical and chemical properties of non-exhaust coarse and fine particles generated by on-road driving and in a laboratory setting using a mobile sampling system. The on-road driving and laboratory measurements performed under constant speed driving revealed that particles produced by tire wear had a size distribution in the range of 2-3 μm, while roadway particles (RWPs) measured behind the front tire during on-road driving largely comprised crustal materials such as road surface wear particles and road dust as well as tire wear particles (TWPs). The mode diameters of particles obtained from on-road driving under cornering conditions were similar to those obtained under constant speed conditions, but with higher concentrations of crustal elements. Under braking conditions, the particulate matter (PM) concentrations of brake wear particles (BWPs) sampled near the brake pad increased significantly and were much higher than the concentration of RWPs during deceleration, indicating that BWPs are one of the main sources of non-exhaust emissions. In addition, BWPs observed from on-road and laboratory measurements had a broader PM size range (1-10 μm) than RWPs. Size-segregated chemical analysis of PM samples indicated that the concentrations of Fe and Ca were highest in the coarse fraction emitted under constant speed and cornering conditions, while Fe, Ba, and Ti were most abundant in the fine fraction emitted during braking events.

  2. Evaluation of a coupled dispersion and aerosol process model against measurements near a major road

    NASA Astrophysics Data System (ADS)

    Pohjola, M. A.; Pirjola, L.; Karppinen, A.; Härkönen, J.; Ketzel, M.; Kukkonen, J.

    2007-02-01

    A field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17-20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm-10 μm (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3-50 nm (mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible at this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic vapour of 1012 molecules cm-3 was shown to be in a disagreement with the measured particle size evolution, while the modelling runs with the

  3. Simultaneous measurements of on-road/in-vehicle nanoparticles and NOx while driving: Actual situations, passenger exposure and secondary formations.

    PubMed

    Yamada, Hiroyuki; Hayashi, Rumiko; Tonokura, Kenichi

    2016-09-01

    Simultaneous measurements of on-road and in-vehicle NO and NO2 levels, particle number concentrations (PNCs), and particles size distributions were performed while driving using a test vehicle equipped with real-time sensors. The results obtained on regional roads showed that heavy-duty vehicles in traffic seem to have a major impact on on-road air quality. Measurements on highways that included a 10km tunnel and a 2km uphill section of road indicated that sub-50nm particles have different features from the other species because of their higher volatility. The other species showed quite high on-road concentrations in the tunnel. In-vehicle conditions were made similar to the on-road ones by setting the air conditioning (AC) mode to the fresh air mode. The in-vehicle NO2 concentration in the tunnel was over 0.50ppmV, which is almost five times higher than the 1-hour ambient air quality standard proposed by the World Health Organization (WHO). In sections other than the tunnel, the in-vehicle NO2 concentration was almost the same as the 1-hour WHO standard. Higher on-road NO2/NOx ratios than those of exhaust gases and different behavior of sub-50nm particles from other species suggested that NO2 and sub-50nm particles were mainly due to secondary products formed by atmospheric reactions. PMID:26806073

  4. Assessment of Continuous Resistivity Profiling for the Characterization of Paved Roads

    NASA Astrophysics Data System (ADS)

    Chouteau, M.; Vallieres, S.; Miralles, M.

    2004-05-01

    We have assessed the continuous resistivity profiling method using towed arrays as a diagnostic NDT method for the evaluation of pavements. Whether the pavement consists of a sequence of asphalt, concrete slab and subgrade layer (rigid pavement) or a layer of asphalt overlying a subgrade and grade base layers (flexible pavement) defects within those different layers can cause pavement deterioration that must be identified. We first examine the response of the method to the various problems using numerical modeling. It is shown that with an optimally designed system the method allows the determination of the thickness and the location of cracks in the asphalt cover. It is also sensitive to the presence of cracks, internal defects and chloride ions (de-icing salt) within the concrete slab below. For reinforced concrete it is possible to estimate the concrete resistivity related directly to its composition (quality) and the thickness of the top coating over the level of rebars. A low resistivity of concrete will usually be diagnostic of advanced stage of rebar corrosion and delamination could occur. However it is shown that the rebars cause current channeling and the depth of investigation is limited then to the depth of the first row of rebars. Finally heterogeneities within the foundation reflecting subsidence, bad drainage, frost-defrost cycles or cavities can be mapped. The optimal design is based on a system with 10 to 20 receiver dipoles and one transmitter dipole (first or last of the array) with a dipole length typically of 10 cm that can be used in equatorial or in-line mode. Static resistivity measurements have been carried out at the laboratory scale over concrete slabs built to verify results obtained from the numerical modeling. Observed data fit very well the modeled data and validate the overall conclusions. Tests have been performed in December 2003 in some selected streets (6 visited, 3 re-visited) of Montreal using a CORIM system (Iris Instruments

  5. On-Road measurement of particulate matter emissions from vehicles: particle concentration, size distribution and morphology

    NASA Astrophysics Data System (ADS)

    Salvadori, N.; China, S.; Cook, J.; Kuhns, H. D.; Moosmuller, H.; Mazzoleni, C.

    2010-12-01

    During summer 2010, we conducted a field experiment in Southern Michigan to measure on-road vehicle emissions. During the campaign, particulate matter (PM) concentrations were monitored with a Light Detection and Ranging (Lidar) and transmissometer system. The Lidar and transmissometer system measures PM mass concentration of vehicle exhaust using backscatter and extinction of an ultraviolet laser beam directed across the road. Collocated with the Lidar system we deployed an extractive system inclusive of a LiCor 840 to monitor CO2 concentrations, a laser aerosol spectrometer to measure particle size distributions for PM with diameter larger than 0.1 µm, and a portable condensation particle counter to estimate the total particle number concentration for particles with diameters between~30nm and 1 µm. In addition, road-side vehicle exhaust particles were collected on nuclepore filters for scanning electron microscopy analysis during selected periods of time. In this study we analyze fuel-based mass and number PM emission factors from passing vehicles. The emission factors are estimated normalizing the PM data by the CO2 concentration. The morphology of the particulates is also investigated with electron microscopy analysis. Type of vehicles and traffic counts were recorded by one of the researchers during the sampling period to evaluate the influence on particle morphology due to traffic volume and fuel type. Image processing and fractal geometry are used to estimate various morphological parameters and fractal dimension. Diurnal variation of particle morphology descriptors and fractal dimension of soot particles are investigated and compared with CO2 emissions, particle size distribution and particle number concentration for selected subsets of the data. Variations of PM emission factors and PM morphology are also investigated for different traffic conditions and days of the week. The analysis of the PM data is of particular importance in monitoring vehicle

  6. A Simple Permittivity Calibration Method for GPR-Based Road Pavement Measurements

    NASA Astrophysics Data System (ADS)

    Eskelinen, Pekka

    2016-09-01

    Cylindrical resonator principle can be used in GPR asphalt quality measurement calibration. This method relies on ordinary drill core samples that are regularly taken from measured road sections, but now only analyzed for dimensions, density and sometimes chemically. If such a drill sample is covered with proper conductive surfaces, a cylindrical cavity resonator is formed. The baseline of the GPR permittivity recordings can so be found by measuring the resonance behaviour of this covered sample, which can later still be used for those traditional analyses. A clear benefit is the resonator's 1-2 GHz frequency range which equals that of common commercial GPR systems. Example results and reference readings from known dielectric material are shown. The obtained uncertainty in this case study is 0.02 units of permittivity, when measuring the same sample repeatedly.

  7. Measuring cylindrically symmetric refractive-index profiles: a method.

    PubMed

    Gregoris, D; Iizuka, K

    1983-02-01

    This paper describes a new nondestructive method to measure cylindrically symmetric refractive-index profiles of transparent cylinders. The technique is based on the measurement of the axial displacement of rays that are refracted within the cylinder. Three different types of index profile were experimentally determined. Profile errors of better than one part in 10(3) were achieved using very modest equipment. The effects of certain experimental parameters on the profile accuracy are noted. The technique may be applied to the characterization of optical fiber preforms and graded-index rod lenses. PMID:18195804

  8. Measuring discharge with ADCPs: Inferences from synthetic velocity profiles

    USGS Publications Warehouse

    Rehmann, C.R.; Mueller, D.S.; Oberg, K.A.

    2009-01-01

    Synthetic velocity profiles are used to determine guidelines for sampling discharge with acoustic Doppler current profilers (ADCPs). The analysis allows the effects of instrument characteristics, sampling parameters, and properties of the flow to be studied systematically. For mid-section measurements, the averaging time required for a single profile measurement always exceeded the 40 s usually recommended for velocity measurements, and it increased with increasing sample interval and increasing time scale of the large eddies. Similarly, simulations of transect measurements show that discharge error decreases as the number of large eddies sampled increases. The simulations allow sampling criteria that account for the physics of the flow to be developed. ?? 2009 ASCE.

  9. Characteristics of On-road Diesel Vehicles: Black Carbon Emissions in Chinese Cities Based on Portable Emissions Measurement.

    PubMed

    Zheng, Xuan; Wu, Ye; Jiang, Jingkun; Zhang, Shaojun; Liu, Huan; Song, Shaojie; Li, Zhenhua; Fan, Xiaoxiao; Fu, Lixin; Hao, Jiming

    2015-11-17

    Black carbon (BC) emissions from heavy-duty diesel vehicles (HDDVs) are rarely continuously measured using portable emission measurement systems (PEMSs). In this study, we utilize a PEMS to obtain real-world BC emission profiles for 25 HDDVs in China. The average fuel-based BC emissions of HDDVs certified according to Euro II, III, IV, and V standards are 2224 ± 251, 612 ± 740, 453 ± 584, and 152 ± 3 mg kg(-1), respectively. Notably, HDDVs adopting mechanical pump engines had significantly higher BC emissions than those equipped with electronic injection engines. Applying the useful features of PEMSs, we can relate instantaneous BC emissions to driving conditions using an operating mode binning methodology, and the average emission rates for Euro II to Euro IV diesel trucks can be constructed. From a macroscopic perspective, we observe that average speed is a significant factor affecting BC emissions and is well correlated with distance-based emissions (R(2) = 0.71). Therefore, the average fuel-based and distance-based BC emissions on congested roads are 40 and 125% higher than those on freeways. These results should be taken into consideration in future emission inventory studies. PMID:26462141

  10. Characteristics of On-road Diesel Vehicles: Black Carbon Emissions in Chinese Cities Based on Portable Emissions Measurement.

    PubMed

    Zheng, Xuan; Wu, Ye; Jiang, Jingkun; Zhang, Shaojun; Liu, Huan; Song, Shaojie; Li, Zhenhua; Fan, Xiaoxiao; Fu, Lixin; Hao, Jiming

    2015-11-17

    Black carbon (BC) emissions from heavy-duty diesel vehicles (HDDVs) are rarely continuously measured using portable emission measurement systems (PEMSs). In this study, we utilize a PEMS to obtain real-world BC emission profiles for 25 HDDVs in China. The average fuel-based BC emissions of HDDVs certified according to Euro II, III, IV, and V standards are 2224 ± 251, 612 ± 740, 453 ± 584, and 152 ± 3 mg kg(-1), respectively. Notably, HDDVs adopting mechanical pump engines had significantly higher BC emissions than those equipped with electronic injection engines. Applying the useful features of PEMSs, we can relate instantaneous BC emissions to driving conditions using an operating mode binning methodology, and the average emission rates for Euro II to Euro IV diesel trucks can be constructed. From a macroscopic perspective, we observe that average speed is a significant factor affecting BC emissions and is well correlated with distance-based emissions (R(2) = 0.71). Therefore, the average fuel-based and distance-based BC emissions on congested roads are 40 and 125% higher than those on freeways. These results should be taken into consideration in future emission inventory studies.

  11. 40 CFR 86.129-94 - Road load power, test weight, inertia weight class determination, and fuel temperature profile.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... liquid fuel temperature (Tliq); and (D) Vapor space pressure (the Administrator may omit measurement of... embedded sensor, a portable temperature probe, or an infrared pyrometer that can provide an accuracy of ±2... for developing corrected liquid fuel and vapor space temperature profiles may be used if...

  12. 40 CFR 86.129-94 - Road load power, test weight, inertia weight class determination, and fuel temperature profile.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... liquid fuel temperature (Tliq); and (D) Vapor space pressure (the Administrator may omit measurement of... embedded sensor, a portable temperature probe, or an infrared pyrometer that can provide an accuracy of ±2... relative profile. Other methodologies for developing corrected liquid fuel and vapor space...

  13. 40 CFR 86.129-94 - Road load power, test weight, inertia weight class determination, and fuel temperature profile.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... liquid fuel temperature (Tliq); and (D) Vapor space pressure (the Administrator may omit measurement of... embedded sensor, a portable temperature probe, or an infrared pyrometer that can provide an accuracy of ±2... for developing corrected liquid fuel and vapor space temperature profiles may be used if...

  14. Carbon Dioxide and Methane Measurement on Urban Roads in Nanjing, China

    NASA Astrophysics Data System (ADS)

    Xu, J.; Hu, N.; Lee, X.

    2015-12-01

    In recent years, cities have become more and more reliant on natural gas as a main source of clean energy to reduce air pollution. One unintended consequence, however, is increase in CH4 emissions which contribute to global warming. In Nanjing, the capital city of Jiangsu Province in the Yangtze River Delta, China, almost all taxis and about 30 percent buses are now powered by natural gas, and an increasing number of trucks are switching to natural gas as energy source. However, CH4 emissions from road vehicles have so far been ignored by the Intergovernmental Panel on Climate Change (IPCC) inventory method. In this study, we determined the CH4:CO2 emissions ratio for taxi and other vehicles, using the atmospheric CH4 and CO2 concentrations measured on three main streets in the city of Nanjing. The CH4:CO2 emissions ratio for all vehicles was 0.0088 mol mol-1 on average, a little higher than the ratio measured at the city scale (0.0079 mol mol-1). But the ratio for taxi was much high, with a mean and a median value of 0.014 and 0.0094 mol mol-1, respectively, and a maximum of 0.070 mol mol-1. This atmospheric estimate of the CH4:CO2 emissions ratio for vehicles is in broad agreement with measurement on board of vehicles observing directly tailpipe emission found in the literature. Omission of on road vehicle emission is likely one reason for the 67.3% underestimation Nanjing's methane emissions using the IPCC method (Shen et al. 2014. Advances in Atmospheric Sciences, 31: 1343-1352).

  15. Wind profiler mixing depth and entrainment measurements with chemical applications

    SciTech Connect

    Angevine, W.M.; Trainer, M.; Parrish, D.D.; Buhr, M.P.; Fehsenfeld, F.C.; Kok, G.L.

    1994-12-31

    Wind profiling radars operating at 915 MHz have been present at a number of regional air quality studies. The profilers can provide a continuous, accurate record of the depth of the convective mixed layer with good time resolution. Profilers also provide information about entrainment at the boundary layer top. Mixing depth data from several days of the Rural Oxidants in the Southern Environment II (ROSE II) study in Alabama in June, 1992 are presented. For several cases, chemical measurements from aircraft and ground-based instruments are shown to correspond to mixing depth and entrainment zone behavior observed by the profiler.

  16. The Retrieval of Ozone Profiles from Limb Scatter Measurements: Theory

    NASA Technical Reports Server (NTRS)

    Flittner, D. E.; Herman, B. M.; Bhartia, P. K.; McPeters, R. D.; Hilsenrath, E.

    1999-01-01

    An algorithm is presented for retrieving vertical profiles of O3 concentration using measurements of UV and visible light scattered from the limb of the atmosphere. The UV measurements provide information about the O3 profile in the upper and middle stratosphere, while only visible wavelengths are capable of probing the lower stratospheric O3 profile. Sensitivity to the underlying scene reflectance is greatly reduced by normalizing measurements at a tangent height high in the atmosphere (approximately 55 km), and relating measurements taken at lower altitudes to this normalization point. To decrease the effect of scattering by thin aerosols/clouds that may be present in the field of view, these normalized measurements are then combined by pairing wavelengths with strong and weak O3 absorption. We conclude that limb scatter can be used to measure O3 between 15 km and 50 km with 2-3 km vertical resolution and better than 10% accuracy.

  17. New radiosonde techniques to measure radiation profiles through the atmosphere

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf; Romanens, Gonzague; Levrat, Gilbert

    2013-04-01

    Solar and thermal radiation fluxes are usually measured at Earth's surface and at the top of the atmosphere. Here we show radiosonde techniques that allow measuring radiation flux profiles and the radiation budget from the Earth's surface to above 30 km in the stratosphere. During two-hour flights solar shortwave and thermal longwave irradiance, downward and upward, is measured with four individual sensors at one-second resolution, along with standard PTU radiosonde profiles. Daytime and nighttime shortwave and longwave radiation measurements, and 24 hours surface measurements, allow determining radiation budget- and total net radiation profiles through the atmosphere. We use a double balloon technique to prevent pendulum motion during the ascent and to keep the sonde as horizontal as possible. New techniques using auto controlled airplanes are now investigated to retrieve the sonde after release at a certain altitude and to land it if possible at the launch station.

  18. Method and apparatus for measuring irradiated fuel profiles

    DOEpatents

    Lee, David M.

    1982-01-01

    A new apparatus is used to substantially instantaneously obtain a profile of an object, for example a spent fuel assembly, which profile (when normalized) has unexpectedly been found to be substantially identical to the normalized profile of the burnup monitor Cs-137 obtained with a germanium detector. That profile can be used without normalization in a new method of identifying and monitoring in order to determine for example whether any of the fuel has been removed. Alternatively, two other new methods involve calibrating that profile so as to obtain a determination of fuel burnup (which is important for complying with safeguards requirements, for utilizing fuel to an optimal extent, and for storing spent fuel in a minimal amount of space). Using either of these two methods of determining burnup, one can reduce the required measurement time significantly (by more than an order of magnitude) over existing methods, yet retain equal or only slightly reduced accuracy.

  19. Automatic measurement of spur gear dimensions using laser light, part 2: measurement of flank profile

    NASA Astrophysics Data System (ADS)

    Younes, M. A.; Khalil, Abdallah M.; Damir, Mohamed

    2005-10-01

    In part I of this study a laser-based system for automatic measurement of spur gears' tooth thickness and pitch was introduced. The developed system provides an inaccuracy value on the order of 5 µm, and the measurement time, for all gear teeth, was just about 1 min. In this part the experimental work is further extended to measure the tooth flank profile of spur gears. Flank profile is one of the most important factors that affect gear performance. In gear meshing, motion is transferred through contact along gear flanks. Deviations in flank profile due to errors in manufacturing or nonuniform wear result in variations in gear movement. Measurement of the flank profile can help in adjusting the gear manufacturing process, control the quality of manufactured gears, and monitor the wear of gears during action. The proposed flank profile measurement system is based on the principle of optical triangulation. The flank profile measurement setup is integrated with that of the tooth thickness and pitch, and hence tooth thickness, pitch, and profile measurements are performed simultaneously, and the measurement time for the three parameters for all gear teeth remains less than 1 min. Software is developed to graph the actual tooth profile and evaluate its deviation from nominal shape. The flank profiles measured using the developed system are in good agreement with those obtained from a well-established measurement method.

  20. On-road and wind-tunnel measurement of motorcycle helmet noise.

    PubMed

    Kennedy, J; Carley, M; Walker, I; Holt, N

    2013-09-01

    The noise source mechanisms involved in motorcycling include various aerodynamic sources and engine noise. The problem of noise source identification requires extensive data acquisition of a type and level that have not previously been applied. Data acquisition on track and on road are problematic due to rider safety constraints and the portability of appropriate instrumentation. One way to address this problem is the use of data from wind tunnel tests. The validity of these measurements for noise source identification must first be demonstrated. In order to achieve this extensive wind tunnel tests have been conducted and compared with the results from on-track measurements. Sound pressure levels as a function of speed were compared between on track and wind tunnel tests and were found to be comparable. Spectral conditioning techniques were applied to separate engine and wind tunnel noise from aerodynamic noise and showed that the aerodynamic components were equivalent in both cases. The spectral conditioning of on-track data showed that the contribution of engine noise to the overall noise is a function of speed and is more significant than had previously been thought. These procedures form a basis for accurate experimental measurements of motorcycle noise. PMID:23967933

  1. Void alignment and density profile applied to measuring cosmological parameters

    NASA Astrophysics Data System (ADS)

    Dai, De-Chang

    2015-12-01

    We study the orientation and density profiles of the cosmological voids with Sloan Digital Sky Survey (SDSS; Ahn et al.) 10 data. Using voids to test Alcock-Paczynski effect has been proposed and tested in both simulations and actual SDSS data. Previous observations imply that there exist an empirical stretching factor which plays an important role in the voids' orientation. Simulations indicate that this empirical stretching factor is caused by the void galaxies' peculiar velocities. Recently Hamaus et al. found that voids' density profiles are universal and their average velocities satisfy linear theory very well. In this paper, we first confirm that the stretching effect exists using independent analysis. We then apply the universal density profile to measure the cosmological parameters. We find that the void density profile can be a tool to measure the cosmological parameters.

  2. Compact Instrument for Measuring Profile of a Light Beam

    NASA Technical Reports Server (NTRS)

    Papanyan, Valeri

    2004-01-01

    The beamviewer is an optical device designed to be attached to a charge-coupled-device (CCD) image detector for measuring the spatial distribution of intensity of a beam of light (the beam profile ) at a designated plane intersecting the beam. The beamviewer-and-CCD combination is particularly well suited for measuring the radiant- power profile (for a steady beam) or the radiant-energy profile (for a pulsed beam) impinging on the input face or emerging from the output face of a bundle of optical fibers. The beamviewer and-CCD combination could also be used as a general laboratory instrument for profiling light beams, including beams emerging through small holes and laser beams in free space.

  3. A new method for comparing and matching snow profiles, application for profiles measured by penetrometers

    NASA Astrophysics Data System (ADS)

    Hagenmuller, Pascal; Pilloix, Thibault

    2016-05-01

    Hardness has long been recognized as a good predictor of snow mechanical properties and therefore as an indicator of snowpack stability at the measured point. Portable digital penetrometers enable the amassing of a large number of snow stratigraphic hardness profiles. Numerous probings can be performed to assess the snowpack spatial variability and to compensate for measurement errors. On a decameter scale, continuous internal layers are typically present in the snowpack. The variability in stratigraphic features observed in the measurement set mainly originates from the measured variations in internal layer thickness due to either a real heterogeneity in the snowpack or to errors in depth measurement. For the purpose of real time analysis of snowpack stability, a great amount of data collected by digital penetrometers must be quickly synthesized into a characterization representative of the test site. This paper presents a method with which to match and combine several hardness profiles by automatically adjusting their layer thicknesses. The objectives are to synthesize the information collected by several profiles into one representative profile of the measurement set, disentangle information about hardness and depth variabilities, and quantitatively compare hardness profiles measured by different penetrometers. The method was tested by using co-located hardness profiles measured with three different penetrometers --- the snow micropenetrometer (SMP), the Avatech SP1 and the ramsonde --- during the winter 2014-2015 at two sites in the French Alps. When applied to the SMP profiles of both sites, the method reveals a low spatial variability of hardness properties, which is usually masked by depth variations. The developed algorithm is further used to evaluate the new portable penetrometer SP1. The hardness measured with this instrument is shown to be in good agreement with the SMP measurements, but errors in the recovered depth are notable, with a standard

  4. Differential absorption lidar measurements of atmospheric temperature and pressure profiles

    NASA Technical Reports Server (NTRS)

    Korb, C. L.

    1981-01-01

    The theory and methodology of using differential absorption lidar techniques for the remote measurement of atmospheric pressure profiles, surface pressure, and temperature profiles from ground, air, and space-based platforms are presented. Pressure measurements are effected by means of high resolution measurement of absorption at the edges of the oxygen A band lines where absorption is pressure dependent due to collisional line broadening. Temperature is assessed using measurements of the absorption at the center of the oxygen A band line originating from a quantum state with high ground state energy. The population of the state is temperature dependent, allowing determination of the temperature through the Boltzmann term. The results of simulations of the techniques using Voigt profile and variational analysis are reported for ground-based, airborne, and Shuttle-based systems. Accuracies in the 0.5-1.0 K and 0.1-0.3% range are projected.

  5. Edge profile measurements using Thomson scattering on the KSTAR tokamak.

    PubMed

    Lee, J H; Oh, S; Lee, W R; Ko, W H; Kim, K P; Lee, K D; Jeon, Y M; Yoon, S W; Cho, K W; Narihara, K; Yamada, I; Yasuhara, R; Hatae, T; Yatsuka, E; Ono, T; Hong, J H

    2014-11-01

    In the KSTAR Tokamak, a "Tangential Thomson Scattering" (TTS) diagnostic system has been designed and installed to measure electron density and temperature profiles. In the edge system, TTS has 12 optical fiber bundles to measure the edge profiles with 10-15 mm spatial resolution. These 12 optical fibers and their spatial resolution are not enough to measure the pedestal width with a high accuracy but allow observations of L-H transition or H-L transitions at the edge. For these measurements, the prototype ITER edge Thomson Nd:YAG laser system manufactured by JAEA in Japan is installed. In this paper, the KSTAR TTS system is briefly described and some TTS edge profiles are presented and compared against the KSTAR Charge Exchange Spectroscopy and other diagnostics. The future upgrade plan of the system is also discussed in this paper.

  6. Exploration of ion temperature profile measurements at JET using the upgraded neutron profile monitora)

    NASA Astrophysics Data System (ADS)

    Marocco, D.; Esposito, B.; Riva, M.; JET-EFDA Contributors

    2012-10-01

    The neutron profile monitor (NPM), routinely used at the Joint European Torus for neutron emissivity profile measurements, consists of two fan-shaped arrays of collimators and each line of sight (LOS) is equipped with a NE213 liquid organic scintillator for simultaneous measurements of the 2.5 MeV and 14 MeV neutrons. A digital system developed in ENEA has replaced the analog acquisition electronics and now enables the NPM to perform spatially resolved neutron spectrometry by providing neutron pulse height spectra (PHS) for each LOS. However, the NPM was not originally designed as a spectrometer and, therefore, lacks several key features, such as detailed measurements of the detector response functions and the presence of detector stability monitors. We present a proof of principle of ion temperature profile measurements derived from the NPM PHS in high plasma current discharges using simulated detector response functions.

  7. Vertical NO2 Profile measurements in Hong Kong using DOAS

    NASA Astrophysics Data System (ADS)

    Wenig, Mark; Bräu, Melanie; Zhu, Ying; Lipkowitsch, Ivo; Röttger, Clemens; Fat Lam, Yun

    2016-04-01

    In this presentation we describe our first measurements of vertical NO2 distributions in a street canyon in Hong Kong using different DOAS techniques. One approach is to use mobile cavity-enhanced DOAS (CE-DOAS) measurements on different floors of a high rise building to assemble a profile. In addition to this we use a ToTaL-DOAS (Topographic Target Light Scattering DOAS) approach to measure vertical and horizontal distributions of NO2 SCDs of the Hong Kong skyline including the building we used for the CE-DOAS measurements. As a third option to generate profile information, we use data from the Hong Kong Environmental Protection department (EPD) measurement stations. Each measurement location is at a different height and we used a concentration map we assembled using mobile CE-DOAS measurements which again had been corrected for diurnal variations using a continuously measuring LP-DOAS for horizontal extrapolation. We compare parameterized profiles from those three different methods and discuss how profile information can be used to make urban air quality monitoring more comparable.

  8. Absolute beam emittance measurements at RHIC using ionization profile monitors

    SciTech Connect

    Minty, M.; Connolly, R; Liu, C.; Summers, T.; Tepikian, S.

    2014-08-15

    In the past, comparisons between emittance measurements obtained using ionization profile monitors, Vernier scans (using as input the measured rates from the zero degree counters, or ZDCs), the polarimeters and the Schottky detectors evidenced significant variations of up to 100%. In this report we present studies of the RHIC ionization profile monitors (IPMs). After identifying and correcting for two systematic instrumental errors in the beam size measurements, we present experimental results showing that the remaining dominant error in beam emittance measurements at RHIC using the IPMs was imprecise knowledge of the local beta functions. After removal of the systematic errors and implementation of measured beta functions, precise emittance measurements result. Also, consistency between the emittances measured by the IPMs and those derived from the ZDCs was demonstrated.

  9. A hub dynamometer for measurement of wheel forces in off-road bicycling.

    PubMed

    De Lorenzo, D S; Hull, M L

    1999-02-01

    A dynamometric hubset that measures the two ground contact force components acting on a bicycle wheel in the plane of the bicycle during off-road riding while either coasting or braking was designed, constructed, and evaluated. To maintain compatibility with standard mountain bike construction, the hubs use commercially available shells with modified, strain gage-equipped axles. The axle strain gages are sensitive to forces acting in the radial and tangential directions, while minimizing sensitivity to transverse forces, steering moments, and variations in the lateral location of the center of pressure. Static calibration and a subsequent accuracy check that computed differences between applied and apparent loads developed during coasting revealed root mean squared errors of 1 percent full-scale or less (full-scale load = 4500 N). The natural frequency of the rear hub with the wheel attached exceeded 350 Hz. These performance capabilities make the dynamometer useful for its intended purpose during coasting. To demonstrate this usefulness, sample ground contact forces are presented for a subject who coasted downhill over rough terrain. The dynamometric hubset can also be used to determine ground contact forces during braking providing that the brake reaction force components are known. However, compliance of the fork can lead to high cross-sensitivity and corresponding large (> 5 percent FS) measurement errors at the front wheel.

  10. Extended time-to-collision measures for road traffic safety assessment.

    PubMed

    Minderhoud, M M; Bovy, P H

    2001-01-01

    This article describes two new safety indicators based on the time-to-collision notion suitable for comparative road traffic safety analyses. Such safety indicators can be applied in the comparison of a do-nothing case with an adapted situation, e.g. the introduction of intelligent driver support systems. In contrast to the classical time-to-collision value, measured at a cross section, the improved safety indicators use vehicle trajectories collected over a specific time horizon for a certain roadway segment to calculate the overall safety indicator value. Vehicle-specific indicator values as well as safety-critical probabilities can easily be determined from the developed safety measures. Application of the derived safety indicators is demonstrated for the assessment of the potential safety impacts of driver support systems from which it appears that some Autonomous Intelligent Cruise Control (AICC) designs are more safety-critical than the reference case without these systems. It is suggested that the indicator threshold value to be applied in the safety assessment has to be adapted when advanced AICC-systems with safe characteristics are introduced. PMID:11189125

  11. Estimations of primary nitrogen dioxide exhaust emissions from chemiluminescence NOx measurements in a UK road tunnel.

    PubMed

    Simmons, W A; Seakins, P W

    2012-11-01

    NO and NO(2) measurements have been made using the chemiluminescence method from 115 weekdays during the period 4th Jan-10th Sep 2010 in a well characterised, unventilated tunnel on the Leeds Inner Ring Road. Measurements are made at two points in the tunnel and the difference in NO and NO(2) was attributed to emissions from vehicles in the tunnel. These data have been used to determine the fraction of NOx (NO+NO(2)) as primary NO(2) (f-NO(2)) from vehicles using the tunnel. The average value of f-NO(2) from 7 am to 7 pm was 0.17 (-0.03)(+0.01) in agreement with estimations from the UK National Atmospheric Emissions Inventory (NAEI). However, during the day there was a reproducible increase in f-NO(2) from approximately 0.10 at 7 am to 0.21 at 7 pm which is not reproduced with the current UK vehicle fleet emissions inventories. The increase in f-NO(2) can be qualitatively linked to a decrease in the fraction of NOx arising from heavy goods vehicles and buses. PMID:23000714

  12. Vehicle-specific emissions modeling based upon on-road measurements.

    PubMed

    Frey, H Christopher; Zhang, Kaishan; Rouphail, Nagui M

    2010-05-01

    Vehicle-specific microscale fuel use and emissions rate models are developed based upon real-world hot-stabilized tailpipe measurements made using a portable emissions measurement system. Consecutive averaging periods of one to three multiples of the response time are used to compare two semiempirical physically based modeling schemes. One scheme is based on internally observable variables (IOVs), such as engine speed and manifold absolute pressure, while the other is based on externally observable variables (EOVs), such as speed, acceleration, and road grade. For NO, HC, and CO emission rates, the average R(2) ranged from 0.41 to 0.66 for the former and from 0.17 to 0.30 for the latter. The EOV models have R(2) for CO(2) of 0.43 to 0.79 versus 0.99 for the IOV models. The models are sensitive to episodic events in driving cycles such as high acceleration. Intervehicle and fleet average modeling approaches are compared; the former account for microscale variations that might be useful for some types of assessments. EOV-based models have practical value for traffic management or simulation applications since IOVs usually are not available or not used for emission estimation.

  13. On-road measurement of vehicle tailpipe emissions using a portable instrument.

    PubMed

    Frey, H Christopher; Unal, Alper; Rouphail, Nagui M; Colyar, James D

    2003-08-01

    A study design procedure was developed and demonstrated for the deployment of portable onboard tailpipe emissions measurement systems for selected highway vehicles fueled by gasoline and E85 (a blend of 85% ethanol and 15% gasoline). Data collection, screening, processing, and analysis protocols were developed to assure data quality and to provide insights regarding quantification of real-world intravehicle variability in hot-stabilized emissions. Onboard systems provide representative real-world emissions measurements; however, onboard field studies are challenged by the observable but uncontrollable nature of traffic flow and ambient conditions. By characterizing intravehicle variability based on repeated data collection runs with the same driver/vehicle/route combinations, this study establishes the ability to develop stable modal emissions rates for idle, acceleration, cruise, and deceleration even in the face of uncontrollable external factors. For example, a consistent finding is that average emissions during acceleration are typically 5 times greater than during idle for hydrocarbons and carbon dioxide and 10 times greater for nitric oxide and carbon monoxide. A statistical method for comparing on-road emissions of different drivers is presented. Onboard data demonstrate the importance of accounting for the episodic nature of real-world emissions to help develop appropriate traffic and air quality management strategies.

  14. Removing Traffic Emissions from CO2 Time Series Measured at a Tall Tower Using on-Road Measurements and WRF-Stilt Transport Modeling

    NASA Astrophysics Data System (ADS)

    Schmidt, A.; Rella, C.; Goeckede, M.; Hanson, C. V.; Yang, Z.; Law, B. E.

    2014-12-01

    In recent years, measurements of atmospheric carbon dioxide with high precision and accuracy have become increasingly important for climate change research, in particular to inform terrestrial biosphere models. Anthropogenic carbon dioxide emissions from fossil fuel burning have long been recognized to contribute a significant portion of the carbon dioxide in the atmosphere. Here, we present an approach to remove the traffic related carbon dioxide emissions from mole fractions measured at a tall tower by using the corresponding carbon monoxide measurements in combination with footprint analyses and transport modeling. This technique improves the suitability of the CO2 data to be used in inverse modeling approaches of atmosphere-biosphere exchange that do not account for non-biotic portions of CO2. In our study region in Oregon, road traffic emissions are the biggest source of anthropogenic carbon dioxide and carbon monoxide. A three-day mobile campaign covering 1700 km of roads in northwestern Oregon was performed during summer of 2012 using a laser-based Cavity Ring Down Spectrometer. The mobile measurements incorporated different roads including main highways, urban streets, and back-roads, largely within the typical footprint of a tall CO2 observation tower in Oregon's Willamette Valley. For the first time, traffic related CO:CO2 emission ratios were measured directly at the sources during an on-road campaign under a variety of different driving conditions. An average emission ratio of 7.43 (±1.80) ppb CO per ppm CO2 was obtained for the study region and applied to separate the traffic related portion of CO2 from the mole fraction time series. The road traffic related portion of the CO2 mole fractions measured at the tower site reached maximum values from 9.8 to 12 ppm, depending on the height above the surface, during summer 2012.

  15. Evaluating the air quality impacts of the 2008 Beijing Olympic Games: On-road emission factors and black carbon profiles

    NASA Astrophysics Data System (ADS)

    Wang, Xing; Westerdahl, Dane; Chen, Lung Chi; Wu, Ye; Hao, Jiming; Pan, Xiaochuan; Guo, Xinbiao; Zhang, K. Max

    The aggressive traffic interventions and emission control measures implemented to improve air quality during the 2008 Beijing Olympic Games created a valuable case study to evaluate the effectiveness of these measures on mitigating air pollution and protecting public health. In this paper, we report the results from our field campaign in summer 2008 on the on-road emission factors of carbon monoxide, black carbon (BC) and ultrafine particles (UFP) as well as the ambient BC concentrations. The fleet average emission factors for light-duty gasoline vehicles (LDGV) showed considerable reduction in the Olympic year (2008) compared to the pre-Olympic year (2007). Our measurement of Black Carbon (BC), a primary pollutant, at different elevations at the ambient site suggests consistent decrease in BC concentrations as the height increased near the ground level, which indicates that the nearby ground level sources, probably dominated by traffic, contributed to a large portion of BC concentrations in the lower atmospheric layer in Beijing during summertime. These observations indicate that people living in near ground levels experience higher exposures than those living in higher floors in Beijing. The BC diurnal patterns on days when traffic control were in place during the Olympic Games were compared to those on non-traffic-control days in both 2007 and in 2008. These patterns strongly suggest that diesel trucks are a major source of summertime BC in Beijing. The median BC concentration on Olympic days was 3.7 μg m -3, which was dramatically lower than the value on non-traffic-control days, indicating the effectiveness of traffic control regulations in BC reduction in Beijing.

  16. Density measurements of road overlays samples with nuclear gauges and a Step Frequency Radar

    NASA Astrophysics Data System (ADS)

    Fauchard, C.; Li, B.; Kadi, M.

    2012-04-01

    density measured by nuclear gauges. Nevertheless, the dimensions of slabs limit the results to a small surface compared to the nuclear results and improvements are needed to adapt the method to cylindrical cores samples. These two drawbacks are not encountered on roads and we currently carry out some experiments for in-place density measurement with the Step Frequency Radar. Fauchard C., Li B., Mazari B., "Estimation of compaction of bituminous mixtures at microwave frequencies", NDTCE'09, Nantes, France, Juillet 2009

  17. Determination of precipitation profiles from airborne passive microwave radiometric measurements

    NASA Technical Reports Server (NTRS)

    Kummerow, Christian; Hakkarinen, Ida M.; Pierce, Harold F.; Weinman, James A.

    1991-01-01

    This study presents the first quantitative retrievals of vertical profiles of precipitation derived from multispectral passive microwave radiometry. Measurements of microwave brightness temperature (Tb) obtained by a NASA high-altitude research aircraft are related to profiles of rainfall rate through a multichannel piecewise-linear statistical regression procedure. Statistics for Tb are obtained from a set of cloud radiative models representing a wide variety of convective, stratiform, and anvil structures. The retrieval scheme itself determines which cloud model best fits the observed meteorological conditions. Retrieved rainfall rate profiles are converted to equivalent radar reflectivity for comparison with observed reflectivities from a ground-based research radar. Results for two case studies, a stratiform rain situation and an intense convective thunderstorm, show that the radiometrically derived profiles capture the major features of the observed vertical structure of hydrometer density.

  18. Profile measurements of thin liquid films using reflectometry

    NASA Astrophysics Data System (ADS)

    Hanchak, M. S.; Vangsness, M. D.; Byrd, L. W.; Ervin, J. S.; Jones, J. G.

    2013-11-01

    Microscope-based reflectometry was used to measure the thickness profile of thin films of n-octane on silicon wafer substrates. Coupled with micro-positioning motorized stages and custom software, two-dimensional profiles of the film thickness from the adsorbed film (˜10 nm) to the intrinsic meniscus (˜1000 nm) were automatically and repeatedly measured. The reflectometer aperture was modified to provide better spatial resolution in areas of high curvature, the transition region, where evaporative flux is at a maximum. This technique will provide data for the validation of both existing and future models of thin film evaporation.

  19. Road grade quantification based on global positioning system data obtained from real-world vehicle fuel use and emissions measurements

    NASA Astrophysics Data System (ADS)

    Yazdani Boroujeni, Behdad; Frey, H. Christopher

    2014-03-01

    Real-world vehicle fuel use and emission rates depend on engine load, which is quantified in terms of Vehicle Specific Power (VSP). VSP depends on vehicle speed, acceleration, and road grade. There is not a standard method for measuring road grade from a moving vehicle. A method for quantifying grade is evaluated based on statistical analysis of multiple runs using low cost consumer grade Global Positioning System (GPS) receivers with in-built Barometric Altimeter (GPS/BA). The average grade precision is ±0.71, ±0.46, and ±0.31 percentage points, for sample sizes of 9, 18, and 36 GPS/BA runs, respectively, among 2213 individual 0.08 km road segments. In addition, 4 sets of repeated measurements were performed on the same routes using a high cost, high accuracy Differential GPS (DGPS). Both sets of GPS-based grade estimates compared well with those derived from LIght Detection And Ranging (LIDAR) data. GPS/BA and DGPS grade estimates were similar, except for high magnitude grades of 8-10 percent for which DGPS estimates are more accurate. DGPS is more sensitive to loss of signal; thus, a hybrid approach for substituting GPS/BA data for missing DGPS data at specific locations along a route is demonstrated. The local and overall effects of road grade on fuel use and emission rates are investigated for an example light duty gasoline vehicle.

  20. Measuring of Traction and Speed Characteristics as Well as of Fuel Economy of a Car in Road Conditions

    NASA Astrophysics Data System (ADS)

    Krivtsov, Sergey N.; Syrbakov, Andrey P.; Korchuganova, Marina A.

    2016-08-01

    This article is devoted to the identification of traction and speed characteristics as well as of fuel economy of motor vehicles in road conditions. Among common variants of measuring of the above stated values, the preference was given to the immediate gaining of factors by means of a computer-aided measuring system. There is a theoretical justification given to the suggested approach as well as methods and results allowing to provide a practically sufficient solution accuracy of the problem.

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

    PubMed

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

    2012-10-15

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

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

    PubMed

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

    2012-10-15

    Non-road machinery, especially construction equipment could be an important pollutant source of the deterioration in air quality in Chinese urban areas due to its large quantity and to the absence of stringent emission requirements. In this study, emission tests were performed on 12 excavators and 8 wheel loaders by using portable emission measurement system (PEMS) to determine their emission characteristics. The typical operating modes were categorized as idling mode, moving mode and working mode. Compared with those during idling and moving modes, the average time-based emission factors during working mode of HC were 2.61 and 1.27 times higher, NO(x) were 3.66 and 1.36 times higher, and PM were 4.05 and 1.95 times higher, respectively. Under all conditions, categories of the measured emissions increased with the rise in engine power. Compared with those of Stage I emission standard equipment, gaseous emissions and PM emitted from Stage II emission standard equipment were lower. The results indicated that, from Stage I to Stage II, the average reductions of HC, NO(x) and PM were 56%, 37% and 29% for the working mode, respectively. Those results also demonstrated the effectiveness of emission control regulation and the improvement of emission control technology. The data and tests show that the longer the accumulated working hours, the higher HC and NO(x) average fuel-based emission factors are. The emissions measured from the construction vehicles employed in this study were higher than the data collected in previous studies, which shows that it is critical for the government to put into effect more stringent emission regulations to further improve the air quality in Chinese urban areas. PMID:22944217

  3. Scintillation fiber array detector for measurement of neutron beam profile

    NASA Astrophysics Data System (ADS)

    Kim, Chong; Hong, Byungsik; Jo, Mihee; Lee, Kyong Sei; Sim, Kwang-Souk

    2009-10-01

    We built and tested a detector to measure the profile of fast-neutron beams delivered by the MC50 cyclotron at the Korea Institute of Radiological and Medical Science (KIRAMS). The core component of the detector is a 2×46 array of scintillation fibers. The light output of the scintillation fibers is transformed into a current signal by a 46-channel silicon photodiode and digitized by a current-mode signal processor. This scanning device was designed to cover a neutron beam area of 30×32 cm2. The detector was tested in a neutron beam delivered by the MC50 cyclotron at KIRAMS. We demonstrate that the detector can successfully measure the neutron beam profile at various beam currents from 10 to 20 μA. The proposed neutron beam profile detector will be useful, for example, in radiotherapy applications with neutron intensities above 107 Hz/cm2.

  4. Modeling dune response using measured and equilibrium bathymetric profiles

    USGS Publications Warehouse

    Fauver, Laura A.; Thompson, David M.; Sallenger, Asbury H.

    2007-01-01

    Coastal engineers typically use numerical models such as SBEACH to predict coastal change due to extreme storms. SBEACH model inputs include pre-storm profiles, wave heights and periods, and water levels. This study focuses on the sensitivity of SBEACH to the details of pre-storm bathymetry. The SBEACH model is tested with two initial conditions for bathymetry, including (1) measured bathymetry from lidar, and (2) calculated equilibrium profiles. Results show that longshore variability in the predicted erosion signal is greater over measured bathymetric profiles, due to longshore variations in initial surf zone bathymetry. Additionally, patterns in predicted erosion can be partially explained by the configuration of the inner surf zone from the shoreline to the trough, with surf zone slope accounting for 67% of the variability in predicted erosion volumes.

  5. Retrieval of ozone profiles from GOMOS limb scattered measurements

    NASA Astrophysics Data System (ADS)

    Tukiainen, S.; Kyrölä, E.; Verronen, P. T.; Fussen, D.; Blanot, L.; Barrot, G.; Hauchecorne, A.; Lloyd, N.

    2011-04-01

    The GOMOS (Global Ozone Monitoring by Occultation of Stars) instrument on board the Envisat satellite measures the vertical composition of the atmosphere using the stellar occultation technique. While the night-time occultations of GOMOS have been proven to be of good quality, the daytime occultations are more challenging due to weaker signal-to-noise ratio. During daytime GOMOS measures limb scattered solar radiation in addition to stellar radiation. In this paper we introduce a retrieval method that determines ozone profiles between 20-60 km from GOMOS limb scattered solar radiances. GOMOS observations contain a considerable amount of stray light at high altitudes. We introduce a method for removing stray light and demonstrate its feasibility by comparing the corrected radiances against those measured by the OSIRIS (Optical Spectrograph & Infra Red Imaging System) instrument. For the retrieval of ozone profiles, a standard onion peeling method is used. The first comparisons with other data sets suggest that the retrieved ozone profiles in 22-50 km are within 10% compared with the GOMOS night-time occultations and within 15% compared with OSIRIS. GOMOS has measured about 350 000 daytime profiles since 2002. The retrieval method presented here makes this large amount of data available for scientific use.

  6. A Comparison of Modeled Pollutant Profiles With MOZAIC Aircraft Measurements

    EPA Science Inventory

    In this study, we use measurements performed under the MOZAIC program to evaluate vertical profiles of meteorological parameters, CO, and ozone that were simulated for the year 2006 with several versions of the WRF/CMAQ modeling system. Model updates, including WRF nudging strate...

  7. Dust dynamics in off-road vehicle trails: Measurements on 16 arid soil types, Nevada, USA.

    PubMed

    Goossens, Dirk; Buck, Brenda

    2009-08-01

    Soil analyses and measurements with the Portable In Situ Wind Erosion Laboratory (PI-SWERL) were conducted on 16 soil types in an area heavily affected by off-road vehicle (ORV) driving. Measurements were performed in ORV trails as well as on undisturbed terrain to investigate how ORV driving affects the vulnerability of a soil to emit PM10 (particles<10microm), during the driving as well as during episodes of wind erosion. Particular attention is paid to how the creation of a new trail affects those properties of the topsoil that determine its capability to emit PM10. Also, recommendations are given for adequate management of ORV-designed areas. The type of surface (sand, silt, gravel, drainage) is a key factor with respect to dust emission in an ORV trail. Trails in sand, defined in this study as the grain size fraction 63-2000microm, show higher deflation thresholds (the critical wind condition at which wind erosion starts) than the surrounding undisturbed soil. Trails in silt (2-63microm) and in drainages, on the other hand, have lower deflation thresholds than undisturbed soil. The increase in PM10 emission resulting from the creation of a new ORV trail is much higher for surfaces with silt than for surfaces with sand. Also, the creation of a new trail in silt decreases the supply limitation in the top layer: the capacity of the reservoir of emission-available PM10 increases. For sand the situation is reversed: the supply limitation increases, and the capacity of the PM10 reservoir decreases. Finally, ORV trails are characterized by a progressive coarsening of the top layer with time, but the speed of coarsening is much lower in trails in silt than in trails in sand or in drainages. The results of this study suggest that, to minimize emissions of PM10, new ORV fields should preferably be designed on sandy terrain rather than in silt areas or in drainages.

  8. Space shuttle solid rocket motor Profile Measuring Device (PMD)

    NASA Technical Reports Server (NTRS)

    Redmon, John

    1988-01-01

    The SRM PMD is an electromechanical tool used for measuring and recording the profile and diameters of the solid rocket motor segments, both Tang and Clevis ends. This system consists of a crossbeam assembly that mounts to the SRM segment using the existing assembly pin holes. The mounting configuration is such that the tool can be used to measure Clevis up/Tang down or Clevis up/Tang down. The testing and calibration of the PMD is described.

  9. Direct measurements of the ionization profile in krypton helicon plasmas

    SciTech Connect

    Magee, R. M.; Galante, M. E.; McCarren, D. W.; Scime, E. E.; Gulbrandsen, N.

    2012-12-15

    Helicons are efficient plasma sources, capable of producing plasma densities of 10{sup 19} m{sup -3} with only 100 s W of input rf power. There are often steep density gradients in both the neutral density and plasma density, resulting in a fully ionized core a few cm wide surrounded by a weakly ionized plasma. The ionization profile is usually not well known because the neutral density is typically inferred from indirect spectroscopic measurements or from edge pressure gauge measurements. We have developed a two photon absorption laser induced fluorescence (TALIF) diagnostic capable of directly measuring the neutral density profile. We use TALIF in conjunction with a Langmuir probe to measure the ionization fraction profile as a function of driving frequency, magnetic field, and input power. It is found that when the frequency of the driving wave is greater than a critical frequency, f{sub c} Almost-Equal-To 3f{sub lh}, where f{sub lh} is the lower hybrid frequency at the antenna, the ionization fraction is small (0.1%) and the plasma density low (10{sup 17} m{sup -3}). As the axial magnetic field is increased, or, equivalently, the driving frequency decreased, a transition is observed. The plasma density increases by a factor of 10 or more, the plasma density profile becomes strongly peaked, the neutral density profile becomes strongly hollow, and the ionization fraction in the core approaches 100%. Neutral depletion in the core can be caused by a number of mechanisms. We find that in these experiments the depletion is due primarily to plasma pressure and neutral pumping.

  10. Near-Road Mulltipollutant Profiles: Association between Volatile Organic Compounds and a Tracer Gas Surrogate Near a Busy Highway

    EPA Science Inventory

    This research characterizes associations between multiple pollutants in the near-road environment attributed to a roadway line source. It also examines the use of a tracer gas as a surrogate of mobile source pollutants. Air samples were collected in summa canisters along a 300 m ...

  11. Wire Scanner Beam Profile Measurements for the LANSCE Facility

    SciTech Connect

    Gilpatrick, John D.; Gruchalla, Michael E.; Martinez, Derwin; Pillai, Chandra; Rodriguez Esparza, Sergio; Sedillo, James Daniel; Smith, Brian G.

    2012-05-15

    The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected transverse-beam distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new WS beam profile measurement is being designed, fabricated, and tested. The goals for these new WS's include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based client software). This WS measurement system will measure Hand H{sup +} LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

  12. Uncertainties in aspheric profile measurements with the geometry measuring machine at NIST.

    SciTech Connect

    Griesmann, U.; Machkour-Deshayes, N.; Soons, J.; Kim, B. C.; Wang, Q.; Stoup, J. R.; Assoufid, L.; Experimental Facilities Division; NIST

    2005-01-01

    The Geometry Measuring Machine (GEMM) of the National Institute of Standards and Technology (NIST) is a profilometer for free-form surfaces. A profile is reconstructed from the local curvature of a test part surface, measured at several locations along a line. For profile measurements of free-form surfaces, methods based on local part curvature sensing have strong appeal. Unlike full-aperture interferometry they do not require customized null optics. The uncertainty of a reconstructed profile is critically dependent upon the uncertainty of the curvature measurement and, to a lesser extent, on curvature sensor positioning accuracy. For an instrument of the GEMM type, we evaluate the measurement uncertainties for a curvature sensor based on a small aperture interferometer and then estimate the uncertainty that can be achieved in the reconstructed profile. In addition, profile measurements of a free-form mirror using GEMM are compared with measurements using a long-trace profiler, a coordinate measuring machine, and subaperture-stitching interferometry.

  13. Development of a new generation of optical slope measuring profiler

    SciTech Connect

    Yashchuk, Valeriy V.; Takacs, Peter Z.; McKinney, Wayne R.; Assoufid, Lahsen

    2010-07-09

    We overview the results of a broad US collaboration, including all DOE synchrotron labs (ALS, APS, BNL, NSLS-II, LLNL, LCLS), major industrial vendors of x-ray optics (InSync, Inc., SSG Precision Optronics-Tinsley, Inc., Optimax Systems, Inc.), and with active participation of HBZ-BESSY-II optics group, on development of a new generation slope measuring profiler -- the optical slope measuring system (OSMS). The desired surface slope measurement accuracy of the instrument is<50 nrad (absolute) that is adequate to the current and foreseeable future needs for metrology of x-ray optics for the next generation of light sources.

  14. Estimation of CO2 baseline level using a statistical approach for near-road vehicle emission measurements

    NASA Astrophysics Data System (ADS)

    Wong, Ka Chun; Ning, Zhi; Chan, Ka Lok

    2016-04-01

    Vehicle emission is widely accepted as one of the major air pollution problems in metropolitan. Many different experimental setups have been designed to measure the direct emission from vehicles in order to study their impact to local air quality. Near-road/roadside in-situ measurement is one of the most common methods for vehicle emission measurement, providing emission data of vehicle under real driving conditions. In addition, the measurement system can be fully automatized and provides a better way to collect vehicular emission data. Previous studies show that 5% of the total vehicles contribute 50% of the total vehicle emission. In this study, we use the roadside measurement data for the fuel-based emission factor calculation in order to identify heavy emitters. The emission factor calculation uses CO2 as an indicator for the fuel consumption rate. However, this measurement technique suffers from high detection limit and large uncertainty of the CO2 measurement. As a result, heavy emitters with low fuel consumption rate cannot be easily detected. A new data analysis algorithm is developed to estimate the CO2 baseline for near-road/roadside vehicle emission measurements. We investigated the error distribution of the CO2 measurement and use a statistical approach to identify the baseline levels. Our study provides an alternative solution for the CO2 concentration baseline calculation.

  15. Analysis of actinic flux profiles measured from an ozonesonde balloon

    NASA Astrophysics Data System (ADS)

    Wang, P.; Allaart, M.; Knap, W. H.; Stammes, P.

    2015-04-01

    A green light sensor has been developed at KNMI to measure actinic flux profiles using an ozonesonde balloon. In total, 63 launches with ascending and descending profiles were performed between 2006 and 2010. The measured uncalibrated actinic flux profiles are analysed using the Doubling-Adding KNMI (DAK) radiative transfer model. Values of the cloud optical thickness (COT) along the flight track were taken from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) Cloud Physical Properties (CPP) product. The impact of clouds on the actinic flux profile is evaluated on the basis of the cloud modification factor (CMF) at the cloud top and cloud base, which is the ratio between the actinic fluxes for cloudy and clear-sky scenes. The impact of clouds on the actinic flux is clearly detected: the largest enhancement occurs at the cloud top due to multiple scattering. The actinic flux decreases almost linearly from cloud top to cloud base. Above the cloud top the actinic flux also increases compared to clear-sky scenes. We find that clouds can increase the actinic flux to 2.3 times the clear-sky value at cloud top and decrease it to about 0.05 at cloud base. The relationship between CMF and COT agrees well with DAK simulations, except for a few outliers. Good agreement is found between the DAK-simulated actinic flux profiles and the observations for single-layer clouds in fully overcast scenes. The instrument is suitable for operational balloon measurements because of its simplicity and low cost. It is worth further developing the instrument and launching it together with atmospheric chemistry composition sensors.

  16. Measurements of Reynolds stress profiles in unstratified tidal flow

    USGS Publications Warehouse

    Stacey, M.T.; Monismith, Stephen G.; Burau, J.R.

    1999-01-01

    In this paper we present a method for measuring profiles of turbulence quantities using a broadband acoustic doppler current profiler (ADCP). The method follows previous work on the continental shelf and extends the analysis to develop estimates of the errors associated with the estimation methods. ADCP data was collected in an unstratified channel and the results of the analysis are compared to theory. This comparison shows that the method provides an estimate of the Reynolds stresses, which is unbiased by Doppler noise, and an estimate of the turbulent kinetic energy (TKE) which is biased by an amount proportional to the Doppler noise. The noise in each of these quantities as well as the bias in the TKE match well with the theoretical values produced by the error analysis. The quantification of profiles of Reynolds stresses simultaneous with the measurement of mean velocity profiles allows for extensive analysis of the turbulence of the flow. In this paper, we examine the relation between the turbulence and the mean flow through the calculation of u*, the friction velocity, and Cd, the coefficient of drag. Finally, we calculate quantities of particular interest in turbulence modeling and analysis, the characteristic lengthscales, including a lengthscale which represents the stream-wise scale of the eddies which dominate the Reynolds stresses. Copyright 1999 by the American Geophysical Union.

  17. Measurement and Modeling of Near Road & Near-Port Air Quality

    EPA Science Inventory

    Air pollution from mobile sources has been identified by numerous organizations as a potential public health concern. Based upon multiple near-road and near-source monitoring studies, both busy roadways and large emission sources at ports can significantly impact local air qualit...

  18. Measuring velocity and temperature profile sectional pipeline behind confuser

    NASA Astrophysics Data System (ADS)

    Siažik, Ján; Malcho, Milan; Lenhard, Richard; Novomestský, Marcel

    2016-06-01

    The article deals with the measuring of temperature and velocity profile in area behind confuser in real made scale model of bypass. For proper operation of the equipment it is necessary to know the actual flow in the pipe. Bypasses have wide application and can be also associated with devices for heat recovery, heat exchangers different designs in which may be used in certain circumstances. In the present case, the heat that would otherwise has not been used is used for heating of insulators, and heating the air in the spray-dryer. The measuring principle was verify how the above-mentioned temperature and velocity profile decomposition above confuser on real made scale model.

  19. Evaluating the role of green infrastructures on near-road pollutant dispersion and removal: Modelling and measurement.

    PubMed

    Morakinyo, Tobi Eniolu; Lam, Yun Fat; Hao, Song

    2016-11-01

    To enhance the quality of human life in a rapidly urbanized world plagued with high transportation, the masterful contribution of improved urban and local air quality cannot be overemphasized. In order to reduce human exposure to near-road air pollution, several approaches including the installation of roadside structural barriers especially in open street areas, such as city entrances are being applied. In the present study, the air quality around real world and idealized green infrastructures was investigated by means of numerical simulation and a short field measurement campaign. Fair agreement was found between ENVI-met modelled and measured particulate matter's concentration data around a realistic vegetation barrier indicating a fair representation of reality in the model. Several numerical experiments were conducted to investigate the influence of barrier type (vegetation/hedge and green wall) and dimensions on near-road air quality. The results show different horizontal/vertical patterns and magnitudes of upwind and downwind relative concentration (with and without a barrier) depending on wind condition, barrier type and dimension. Furthermore, an integrated dispersion-deposition approach was employed to assess the impact on air quality of near-road vegetation barrier. At last, recommendations to city and urban planners on the implementation of roadside structural barriers were made.

  20. Evaluating the role of green infrastructures on near-road pollutant dispersion and removal: Modelling and measurement.

    PubMed

    Morakinyo, Tobi Eniolu; Lam, Yun Fat; Hao, Song

    2016-11-01

    To enhance the quality of human life in a rapidly urbanized world plagued with high transportation, the masterful contribution of improved urban and local air quality cannot be overemphasized. In order to reduce human exposure to near-road air pollution, several approaches including the installation of roadside structural barriers especially in open street areas, such as city entrances are being applied. In the present study, the air quality around real world and idealized green infrastructures was investigated by means of numerical simulation and a short field measurement campaign. Fair agreement was found between ENVI-met modelled and measured particulate matter's concentration data around a realistic vegetation barrier indicating a fair representation of reality in the model. Several numerical experiments were conducted to investigate the influence of barrier type (vegetation/hedge and green wall) and dimensions on near-road air quality. The results show different horizontal/vertical patterns and magnitudes of upwind and downwind relative concentration (with and without a barrier) depending on wind condition, barrier type and dimension. Furthermore, an integrated dispersion-deposition approach was employed to assess the impact on air quality of near-road vegetation barrier. At last, recommendations to city and urban planners on the implementation of roadside structural barriers were made. PMID:27544646

  1. Prediction of flow profiles in arteries from local measurements.

    NASA Technical Reports Server (NTRS)

    Ling, S. C.; Atabek, H. B.

    1971-01-01

    This paper develops an approximate numerical method for calculating flow profiles in arteries. The theory takes into account the nonlinear terms of the Navier-Stokes equations as well as the large deformations of the arterial wall. The method, assuming axially symmetric flow, determines velocity distribution and wall shear at a given location from the locally measured values of the pressure, pressure gradient, and pressure-radius relation. The computed results agree well with the corresponding experimental data.

  2. Neutron emission profiles and energy spectra measurements at JET

    SciTech Connect

    Giacomelli, L.; Conroy, S.; Belli, F.; Riva, M.; Gorini, G.; Horton, L.; Joffrin, E.; Lerche, E.; Murari, A.; Popovichev, S.; Syme, B.; Collaboration: JET EFDA Contributors

    2014-08-21

    The Joint European Toras (JET, Culham, UK) is the largest tokamak in the world. It is devoted to nuclear fusion experiments of magnetic confined Deuterium (D) or Deuterium-Tritium (DT) plasmas. JET has been upgraded over the years and recently it has also become a test facility of the components designed for ITER, the next step fusion machine under construction in Cadarache (France). JET makes use of many different diagnostics to measure the physical quantities of interest in plasma experiments. Concerning D or DT plasmas neutron production, various types of detectors are implemented to provide information upon the neutron total yield, emission profile and energy spectrum. The neutron emission profile emitted from the JET plasma poloidal section is reconstructed using the neutron camera (KN3). In 2010 KN3 was equipped with a new digital data acquisition system capable of high rate neutron measurements (<0.5 MCps). A similar instrument will be implemented on ITER and it is currently in its design phase. Various types of neutron spectrometers with different view lines are also operational on JET. One of them is a new compact spectrometer (KM12) based on organic liquid scintillating material which was installed in 2010 and implements a similar digital data acquisition system as for KN3. This article illustrates the measurement results of KN3 neutron emission profiles and KM 12 neutron energy spectra from the latest JET D experimental campaign C31.

  3. NO2 lidar profile measurements for satellite interpretation and validation

    NASA Astrophysics Data System (ADS)

    Volten, H.; Brinksma, E. J.; Berkhout, A. J. C.; Hains, J.; Bergwerff, J. B.; van der Hoff, G. R.; Apituley, A.; Dirksen, R. J.; Calabretta-Jongen, S.; Swart, D. P. J.

    2009-12-01

    Satellite instruments are efficient detectors of air pollutants such as NO2. However, the interpretation of satellite retrievals is not a trivial matter. We describe a novel instrument, the RIVM NO2 mobile lidar, to measure tropospheric NO2 profiles for the interpretation and validation of satellite data. During the DANDELIONS campaign in 2006 we obtained an extensive collection of lidar NO2 profiles, coinciding with OMI and SCIAMACHY overpasses. On clear days and early mornings a comparison between lidar and in situ measurements showed excellent agreement. At other times the in situ monitors with molybdenum converters suffered from NOy interference. The lidar NO2 profiles indicated a well-mixed boundary layer, with high NO2 concentrations in the boundary layer and concentrations above not differing significantly from zero. The boundary layer concentrations spanned a wide range, which likely depends on the wind directions and on the intensity of local (rush hour) traffic which varies with the day of the week. Large diurnal differences were mainly driven by the height of the boundary layer, although direct photolysis or photochemical processes also contribute. Small-scale temporal and spatial variations in the NO2 concentrations of the order of 20-50% were measured, probably indicative of small-scale eddies. A preliminary comparison between satellite and lidar data shows that the satellite data tend to overestimate the amount of NO2 in the troposphere compared to the lidar data.

  4. Measurements of temperature profiles at the exit of small rockets.

    PubMed

    Griggs, M; Harshbarger, F C

    1966-02-01

    The sodium line reversal technique was used to determine the reversal temperature profile across the exit of small rockets. Measurements were made on one 73-kg thrust rocket, and two 23-kg thrust rockets with different injectors. The large rocket showed little variation of reversal temperature across the plume. However, the 23-kg rockets both showed a large decrease of reversal temperature from the axis to the edge of the plume. In addition, the sodium line reversal technique of temperature measurement was compared with an infrared technique developed in these laboratories.

  5. Greenhouse gases measurements in road tunnel in São Paulo Megacity, Brazil

    NASA Astrophysics Data System (ADS)

    Fornaro, A.; Andrade, M. F.; Ynoue, R. Y.; Galichio, W.; Astolfo, R.; Miranda, R. M.

    2012-04-01

    The Metropolitan Area of São Paulo (MASP) is the richest area in Brazil and is one of the largest megacities in the world, with more than 20 million inhabitants. The fleet, with more than 7 million vehicles, is unique in that most are fueled by ethanol or by a gasoline-ethanol (flex-fuel vehicles) mixture containing 75-78% gasoline (by volume) and 22-25% ethanol (a blend referred to as gasohol). Nowadays, approximately 50% of the fuel burned by the fleet is ethanol. The vehicular emissions are responsible for approximately 98, 97, and 96%, respectively, of all emissions of carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx). In addition, the fleet is the largest source of CO2 emissions in the MASP. The goal is to evaluate of the vehicles emissions of the pollutants and greenhouse gases (CH4 and CO2) in the MASP. The gases carbon dioxide and methane were carried out by Picarro G2301 Analyzer for CO2/CH4/H2O in air. Field measurements were carried out in two road tunnels within the MASP: May 2 to 13, 2011 in the Janio Quadros (JQ) tunnel and from July 04 to 19, 2011 in the Rodoanel (RA) tunnel. The JQ tunnel is located in the southwest portion of São Paulo. It is a two-lane tunnel that is 1900 m in length, and the traffic in both lanes flows in the same directions. The in-tunnel emissions are mainly from gasohol- and ethanol-powered vehicles. The RA tunnel is located in the West portion of the city and different from JQ tunnel. It is 1700m in length and carries gasohol, ethanol and diesel powered vehicles, being that approximately 40% of the heavy-duty (burning diesel) in its four-lane. The results showed that the effects of the number and velocity of the vehicles in the variability of greenhouse gases and pollutants. The carbon dioxide reaching the hourly maximum value of 550 ppm in-inside the JQ tunnel, and 900 ppm in-side the RA tunnel.

  6. Estimating Concentrations of Road-Salt Constituents in Highway-Runoff from Measurements of Specific Conductance

    USGS Publications Warehouse

    Granato, Gregory E.; Smith, Kirk P.

    1999-01-01

    Discrete or composite samples of highway runoff may not adequately represent in-storm water-quality fluctuations because continuous records of water stage, specific conductance, pH, and temperature of the runoff indicate that these properties fluctuate substantially during a storm. Continuous records of water-quality properties can be used to maximize the information obtained about the stormwater runoff system being studied and can provide the context needed to interpret analyses of water samples. Concentrations of the road-salt constituents calcium, sodium, and chloride in highway runoff were estimated from theoretical and empirical relations between specific conductance and the concentrations of these ions. These relations were examined using the analysis of 233 highwayrunoff samples collected from August 1988 through March 1995 at four highway-drainage monitoring stations along State Route 25 in southeastern Massachusetts. Theoretically, the specific conductance of a water sample is the sum of the individual conductances attributed to each ionic species in solution-the product of the concentrations of each ion in milliequivalents per liter (meq/L) multiplied by the equivalent ionic conductance at infinite dilution-thereby establishing the principle of superposition. Superposition provides an estimate of actual specific conductance that is within measurement error throughout the conductance range of many natural waters, with errors of less than ?5 percent below 1,000 microsiemens per centimeter (?S/cm) and ?10 percent between 1,000 and 4,000 ?S/cm if all major ionic constituents are accounted for. A semi-empirical method (adjusted superposition) was used to adjust for concentration effects-superposition-method prediction errors at high and low concentrations-and to relate measured specific conductance to that calculated using superposition. The adjusted superposition method, which was developed to interpret the State Route 25 highway-runoff records, accounts for

  7. Validation of streamflow measurements made with acoustic doppler current profilers

    USGS Publications Warehouse

    Oberg, K.; Mueller, D.S.

    2007-01-01

    The U.S. Geological Survey and other international agencies have collaborated to conduct laboratory and field validations of acoustic Doppler current profiler (ADCP) measurements of streamflow. Laboratory validations made in a large towing basin show that the mean differences between tow cart velocity and ADCP bottom-track and water-track velocities were -0.51 and -1.10%, respectively. Field validations of commercially available ADCPs were conducted by comparing streamflow measurements made with ADCPs to reference streamflow measurements obtained from concurrent mechanical current-meter measurements, stable rating curves, salt-dilution measurements, or acoustic velocity meters. Data from 1,032 transects, comprising 100 discharge measurements, were analyzed from 22 sites in the United States, Canada, Sweden, and The Netherlands. Results of these analyses show that broadband ADCP streamflow measurements are unbiased when compared to the reference discharges regardless of the water mode used for making the measurement. Measurement duration is more important than the number of transects for reducing the uncertainty of the ADCP streamflow measurement. ?? 2007 ASCE.

  8. Water Vapor Profiling From CoSSIR Radiometric Measurements

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Chang, L. A.; Monosmith, B.; Zhang, Z.

    2007-01-01

    Previous millimeter-wave radiometry for water vapor profiling, by either airborne or satellite sensors, has been limited to frequencies less than or equal to 183 GHz. The retrievals are generally limited to an altitude range of 0-10 km. The additional measurements at the frequencies of 380.2 plus or minus 0.8, 380.2 plus or minus 1.8, 380.2 plus or minus 3.3, and 380.2 plus or minus 6.2 GHz provided by the new airborne Compact Scanning Submillimeter-wave Imaging Radiometer (CoSSIR) can extend this profiling capability up to an altitude of about 15 km. Furthermore, the retrievals can be performed over both land and water surfaces in the tropics without much difficulty. These properties are demonstrated by recent CoSSIR measurements on board the NASA WB-57 aircraft during CR-AVE in January 2006. Retrievals of water vapor mixing ratio were performed at eight altitude levels of 1, 3, 5, 7, 9, 11, 13, and 15 km from CoSSIR data sets acquired at observational angles of 0 and 53.4 degrees, and the results were compared with other available measurements from the same aircraft and near-concurrent satellites. A comparison of the variations of mixing ratios retrieved from CoSSIR and those derived from the Meteorological Measurement System (MMS) in the aircraft vicinity, along the path of the transit flight on January 14, 2006, appears to show some connection, although the measurements were referring to different altitudes. A very good agreement was found between the collocated values of total precipitable water derived from the CoSSIR-retrieved water vapor profiles and those estimated from TMI (TRMM Microwave Imager)

  9. Retrieval of ozone profiles from GOMOS limb scattered measurements

    NASA Astrophysics Data System (ADS)

    Tukiainen, S.; Kyrölä, E.; Verronen, P. T.; Fussen, D.; Blanot, L.; Barrot, G.; Hauchecorne, A.; Lloyd, N.

    2010-10-01

    The GOMOS (Global Ozone Monitoring by Occultation of Stars) instrument on board the Envisat satellite measures the vertical composition of the atmosphere using the stellar occultation technique. While the night-time data of GOMOS are proved to be of good quality, the daytime observations are more challenging due to poorer signal-to-noise ratio. In this paper we present an alternative technique, which uses GOMOS limb scattered radiances instead of the stellar signal, to retrieve stratospheric ozone profiles. Like for many other limb-viewing instruments, GOMOS observations contain stray light at high altitudes. We introduce a method for removing the stray light and demonstrate its feasibility by comparing the corrected radiances against those from the OSIRIS (Optical Spectrograph & Infra Red Imaging System) instrument. For the retrieval of ozone profiles, an onion peeling method is used. The first validation results suggest that the retrieval of stratospheric ozone is possible with a typical accuracy better than 10% at 22-50 km. GOMOS has measured about 350 000 daytime profiles since 2002. The new retrieval method presented here makes this large amount of data finally available for scientific use.

  10. Density Profile Measurement in the TS-4 Merging Device

    NASA Astrophysics Data System (ADS)

    Hayashiya, Hitoshi; Ono, Yasushi; Katsurai, Makoto

    1999-11-01

    A CO2 laser interferometer system is being developed to measure density profiles of merging plasmas in new-built plasma merging device, TS-4 (university of Tokyo Spherical torus-4). The TS-4 merging device introduces a flux-core method to produce compact toroid whose major and minor radii are 0.50m, 0.42m, and its electron density will be ranging from 5× 10^19 to 5 × 10^20, respectively. Its main experimental subjects are to investigate (1) merging formation of field-reversed configuration (FRC), (2) ultra-high-beta spherical tokamak (ST) formation by use of FRC, (3) comparative study of ST, spheromak, FRC and reversed-field pinches (RFP) and (4) laboratory experiment of magnetic reconnection. The multi-cannel Michelson interferometer with heterodyne modulator has from 5 to 10 beam paths of 60W CO2 laser (10.6μm) to measure radial profile of electron density on the midplane. The electron density profile of merging toroids especially around the ``X-point'' will be studied in detail and its physical properties will be discussed.

  11. Ultra-narrow linewidth measurement based on Voigt profile fitting.

    PubMed

    Chen, Mo; Meng, Zhou; Wang, Jianfei; Chen, Wei

    2015-03-01

    We study the method of Voigt profile fitting for ultra-narrow linewidth measurement. It filters out the effect of the spectrum broadening due to the 1/f frequency noise and extracts out the Lorentzian lineshape from the measured spectrum. The resolution is thus greatly promoted than the direct measurement from the self-heterodyne technique. We apply this method to an ultra-narrow-linewidth (~40 Hz by heterodyne beat technique) Brillouin/erbium fiber laser. The linewidth estimated from Voigt fitting method is indicated to be more accurate. In contrast, the linewidths estimated direct from the 3-dB and the 20-dB heterodyne-spectrum width are far over the true linewidth of the BEFL. The Voigt fitting method provides an efficient tool for ultra-narrow-linewidth measurement. And compared with heterodyne beat technique, it is applicable for all types of lasers. PMID:25836899

  12. Mobile Laboratory Measurements of On-Road Vehicle Air Toxics Emissions in Mexico City

    NASA Astrophysics Data System (ADS)

    Kolb, C. E.; Herndon, S. C.; Zavala, M.; Knighton, B.; Marr, L. C.; Zahniser, M. S.; Jayne, J. T.; Shorter, J. H.; Onasch, T. B.; Canagaratna, M. R.; Worsnop, D. R.; Molina, L. T.; Molina, M. J.

    2004-12-01

    The direct emission of toxic organic pollutants from mobile sources is an issue of growing concern. The U.S. Environmental Protection Agency (EPA) and the Federal Highway Administration (FHWA) have identified formaldehyde, acetaldehyde, benzene, acrolein, 1.3 butadiene, and diesel particulate matter (PM), including associated organic compounds, as mobile emissions of priority concern. Real-time trace gas and fine PM sensors deployed on the Aerodyne Research Mobile Laboratory have been used to characterize both fleet average and individual vehicle class on-road emissions of formaldehyde, acetaldehyde, benzene, and diesel particulate matter (PM), including associated organic compounds in the Mexico City Metropolitan Area (MCMA). Data for these air toxics emissions will be reviewed and compared to similar data taken in Boston and New York City, where available. The prospects for future on-road real-time monitoring of acroleinand1.3 butadiene will be discussed.

  13. Effects of winter road grooming on bison in YNP

    USGS Publications Warehouse

    Bjornlie, Daniel D; Garrott, R.A.

    2001-01-01

    The effects of winter recreation—specifically snowmobiling—on wildlife in Yellowstone National Park (YNP) have become high-profile management issues. The road grooming needed to support oversnow travel in YNP is also being examined for its effects on bison (Bison bison) ecology. Data were collected from November 1997 through May 1998 and from December 1998 through May 1999 on the effects of road grooming on bison in Madison–Gibbon–Firehole (MGF) area of YNP Peak bison numbers occurred during late March—early April and were strongly correlated with the snow water equivalent measurements in the Hayden Valley area (1997–1998: r* = 0.62, p:0.001: 1998–1999: r2 = 0.64, P-0.001). Data from an infrared trail monitor on the Mary Mountain trail between the Hayden and Firehole valleys suggest that this trail is the sole corridor for major bison distributional shifts between these locations. Of the 28,293 observations of individual bison made during the study, 8% were traveling and 69% were foraging. These percentages were nearly identical during the period of winter road grooming (7% and 68%, respectively). During this period, 77% of bison foraging activity and 12% of bison traveling activity involved displacing snow. Most travel took place off roads (P<0.001), Bison utilized geothermal features, a network of trails they established, and river and stream banks for travel. Bison road use was negatively correlated with road grooming, with peak use in April and lowest use during the road-grooming period. Bison in the MGF area of YNF neither seek out nor avoid groomed roads. The minimal use of roads compared to off-road areas, the short distances traveled on the roads, the decreased use of roads during the over snow vehicle (OSV) season, and the increased costs of negative interactions with OSVs suggest that grooming roads during winter does not have a major influence on bison ecology.

  14. Measurements with UV-DOAS in a street tunnel for validation of emission factors for road vehicles

    NASA Astrophysics Data System (ADS)

    Rodler, Johannes; Sturm, Peter J.; Lechner, Bernhard

    2001-02-01

    12 The emission behavior of road vehicles is usually estimated by application of emission factors and models. The validity of such factors or models in real world situations can be investigated by tunnel measurements, because road tunnels can be considered as big laboratories with well known boundary conditions. Tunnel experiments were carried out in the 10 km long Plabutschtunnel near Graz, Austria for a period of six weeks in November 1998 and another four weeks in May 1999. A UV- DOAS-system was operated in open-path mode located some 4 km inside the tunnel with pathlengths of 220 m to 430 m. To have an idea about the uniformity of the pollutant air mixture within the path, a comparison of NO2 measurements performed with a standard chemiluminescent analyser (point measurement) and the DOAS system (open-path measurement) was done. Therefore a standard air quality monitoring-system (AQM) in a container was installed in a niche inside the tunnel on one end of the DOAS path. The analysis of data showed good agreement of emissions derived from the measurements with the existing PC and HDV emission factors for CO. This was not the case for benzene and NOx emissions obtained from heavy duty vehicles.

  15. Real-world emissions and fuel consumption of diesel buses and trucks in Macao: From on-road measurement to policy implications

    NASA Astrophysics Data System (ADS)

    Wu, Xiaomeng; Zhang, Shaojun; Wu, Ye; Li, Zhenhua; Zhou, Yu; Fu, Lixin; Hao, Jiming

    2015-11-01

    A total of 13 diesel buses and 12 diesel trucks in Macao were tested using portable emission measurement systems (PEMS) including a SEMTECH-DS for gaseous emissions and a SEMTECH-PPMD for PM2.5. The average emission rates of gaseous pollutants and CO2 are developed with the operating mode defined by the instantaneous vehicle specific power (VSP) and vehicle speed. Both distance-based and fuel mass-based emission factors for gaseous pollutants (e.g., CO, THC and NOX) are further estimated under typical driving conditions. The average distance-based NOX emission of heavy-duty buses (HDBs) is higher than 13 g km-1. Considering the unfavorable conditions for selective reductions catalyst (SCR) systems, such as low-speed driving conditions, more effective technology options (e.g., dedicated natural gas buses and electric buses) should be considered by policy makers in Macao. We identified strong effects of the vehicle size, engine displacement and driving conditions on real-world CO2 emission factors and fuel consumption for diesel vehicles. Therefore, detailed profiles regarding vehicle specifications can reduce the uncertainty in their fleet-average on-road fuel consumption. In addition, strong correlations between relative emission factors and driving conditions indicated by the average speed of generated micro-trips are identified based on a micro-trip method. For example, distance-based emission factors of HDBs will increase by 39% for CO, 29% for THC, 43% for NOX and 26% for CO2 when the average speed decreases from 30 km h-1 to 20 km h-1. The mitigation of on-road emissions from diesel buses and trucks by improving traffic conditions through effective traffic and economic management measures is therefore required. This study demonstrates the important role of PEMS in understanding vehicle emissions and mitigation strategies from science to policy perspectives.

  16. Atmospheric Temperature Profile Measurements Using Mobile High Spectral Resolution Lidar

    NASA Astrophysics Data System (ADS)

    Razenkov, Ilya I.; Eloranta, Edwin W.

    2016-06-01

    The High Spectral Resolution Lidar (HSRL) designed at the University of Wisconsin-Madison discriminates between Mie and Rayleigh backscattering [1]. It exploits the Doppler effect caused by thermal motion of molecules, which broadens the spectrum of the transmitted laser light. That allows for absolute calibration of the lidar and measurements of the aerosol volume backscatter coefficient. Two iodine absorption filters with different absorption line widths (a regular iodine vapor filter and Argon buffered iodine filter) allow for atmospheric temperature profile measurements. The sensitivity of the measured signal-to-air temperature ratio is around 0.14%/K. The instrument uses a shared telescope transmitter-receiver design and operates in eyesafe mode (the product of laser average power and telescope aperture equals 0.1 Wm2 at 532 nm).

  17. Development of a new generation of optical slope measuring profiler

    SciTech Connect

    Yashchuk, Valeriy V.; Takacs, Peter Z.; McKinney, Wayne R.; Assoufid, Lahsen; Siewert, Frank; Zeschke, Thomas

    2010-09-16

    A collaboration, including all DOE synchrotron labs, industrial vendors of x-ray optics, and with active participation of the HBZ-BESSY-II optics group has been established to work together on a new slope measuring profiler -- the optical slope measuring system (OSMS). The slope measurement accuracy of the instrument is expected to be<50 nrad for the current and future metrology of x-ray optics for the next generation of light sources. The goals were to solidify a design that meets the needs of mirror specifications and also be affordable; and to create a common specification for fabrication of a multi-functional translation/scanning (MFTS) system for the OSMS. This was accomplished by two collaborative meetings at the ALS (March 26, 2010) and at the APS (May 6, 2010).

  18. Neuropsychological profile in adult schizophrenia measured with the CMINDS.

    PubMed

    van Erp, Theo G M; Preda, Adrian; Turner, Jessica A; Callahan, Shawn; Calhoun, Vince D; Bustillo, Juan R; Lim, Kelvin O; Mueller, Bryon; Brown, Gregory G; Vaidya, Jatin G; McEwen, Sarah; Belger, Aysenil; Voyvodic, James; Mathalon, Daniel H; Nguyen, Dana; Ford, Judith M; Potkin, Steven G

    2015-12-30

    Schizophrenia neurocognitive domain profiles are predominantly based on paper-and-pencil batteries. This study presents the first schizophrenia domain profile based on the Computerized Multiphasic Interactive Neurocognitive System (CMINDS(®)). Neurocognitive domain z-scores were computed from computerized neuropsychological tests, similar to those in the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB), administered to 175 patients with schizophrenia and 169 demographically similar healthy volunteers. The schizophrenia domain profile order by effect size was Speed of Processing (d=-1.14), Attention/Vigilance (d=-1.04), Working Memory (d=-1.03), Verbal Learning (d=-1.02), Visual Learning (d=-0.91), and Reasoning/Problem Solving (d=-0.67). There were no significant group by sex interactions, but overall women, compared to men, showed advantages on Attention/Vigilance, Verbal Learning, and Visual Learning compared to Reasoning/Problem Solving on which men showed an advantage over women. The CMINDS can readily be employed in the assessment of cognitive deficits in neuropsychiatric disorders; particularly in large-scale studies that may benefit most from electronic data capture. PMID:26586142

  19. Estimation of road vehicle exhaust emissions from 1992 to 2010 and comparison with air quality measurements in Genoa, Italy

    NASA Astrophysics Data System (ADS)

    Zamboni, Giorgio; Capobianco, Massimo; Daminelli, Enrico

    An investigation into road transport exhaust emissions in the Genoa urban area was performed by comparing the quantities of carbon monoxide (CO), nitrogen oxides (NO x), nitrogen dioxide (NO 2) and particulate matter (PM) emitted by different vehicle categories with air quality measurements referred to the same pollutants. Exhaust emissions were evaluated by applying the PROGRESS (computer PROGramme for Road vehicle EmiSSions evaluation) code, developed by the Internal Combustion Engines Group of the University of Genoa, to eight different years (from 1992 to 2010), considering spark ignition and Diesel passenger cars and light duty vehicles, heavy duty vehicles and buses, motorcycles and mopeds. Changes in terms of vehicles number, mileage and total emissions are presented together with relative distributions among the various vehicle categories. By comparing 1992 and 2010 data, calculated trends show a 7% increase in the number of vehicles, with total mileage growing at a faster rate (approx. 22%); total emissions decrease considerably, by approximately 50% for NO x and PM, 70% for HC and 80% for CO, due to improvements in engines and fuels forced by the stricter European legislation and the fleet renewal, while primary NO 2 emission will be very close to 1992 level, after a decrease of about 18% in 2000. Air quality was analysed by selecting traffic and background measuring stations from the monitoring network managed by the Environmental Department of the Province of Genoa: average annual concentrations of considered pollutants from 1994 to 2007 were calculated in order to obtain the relative historical trends and compare them with European public health limits and with road vehicle emissions. Though an important reduction in pollutant concentrations has been achieved as a consequence of cleaner vehicles, some difficulties in complying with present and/or future NO 2 and PM 10 limits are also apparent, thus requiring suitable measures to be taken by the local

  20. Measurement of the lunar neutron density profile. [Apollo 17 flight

    NASA Technical Reports Server (NTRS)

    Woolum, D. S.; Burnett, D. S.; Furst, M.; Weiss, J. R.

    1974-01-01

    An in situ measurement of the lunar neutron density from 20 to 400 g/sq cm depth between the lunar surface was made by the Apollo 17 Lunar Neutron Probe Experiment using particle tracks produced by the B10(n, alpha)Li7 reaction. Both the absolute magnitude and depth profile of the neutron density are in good agreement with past theoretical calculations. The effect of cadmium absorption on the neutron density and in the relative Sm149 to Gd157 capture rates obtained experimentally implies that the true lunar Gd157 capture rate is about one half of that calculated theoretically.

  1. Measurement of ion profiles in TFTR neutral beamlines

    SciTech Connect

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O`Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-02-01

    A technique is described whereby the ion dumps inside the TFTR Neutral Beam Test Stand were used to measure thermal profiles of the full-, half-, and third-energy ions. 136 thermocouples were installed on the full-energy ion dump, allowing full beam contours. Additional linear arrays across the widths of the half- and third-energy ion dumps provided a measure of the shape, in the direction parallel to the grid rails, of the half- and third-energy ions, and, hence, of the molecular ions extracted from the source. As a result of these measurements it was found that the magnet was more weakly focusing, by a factor of two, than expected, explaining past overheating of the full-energy ion dump. Hollow profiles on the half- and third-energy ion dumps were observed, suggesting that extraction of D{sub 2}+ and D{sub 3}+ are primarily from the edge of the ion source. If extraction of half-energy ions is from the edge of the accelerator, a divergence parallel to the grid rails of 0.6{degrees}{plus_minus}0.1{degrees} results. It is postulated that a nonuniform gas profile near the accelerator is the cause of the hollow partial-energy ion profiles; the pressure being depressed over the accelerator by particles passing through this highly transparent structure. Primary electrons reaching the accelerator produce nonuniform densities of D{sub 2}+ through the ionization of this across the full-energy dump was examined as a means of reducing the power density. By unbalancing the current in the two coils of the magnet, on a shot by shot basis, by up to 2:1 ratio, it was possible to move the centerline of the full-energy ion beam sideways by {approximately}12.5 cm. The adoption of such a technique, with a ramp of the coil imbalance from 2:1 to 1:2 over a beam pulse, could reduce the power density by a factor of {ge}1.5.

  2. Measurement of ion profiles in TFTR neutral beamlines

    SciTech Connect

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O'Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-02-01

    A technique is described whereby the ion dumps inside the TFTR Neutral Beam Test Stand were used to measure thermal profiles of the full-, half-, and third-energy ions. 136 thermocouples were installed on the full-energy ion dump, allowing full beam contours. Additional linear arrays across the widths of the half- and third-energy ion dumps provided a measure of the shape, in the direction parallel to the grid rails, of the half- and third-energy ions, and, hence, of the molecular ions extracted from the source. As a result of these measurements it was found that the magnet was more weakly focusing, by a factor of two, than expected, explaining past overheating of the full-energy ion dump. Hollow profiles on the half- and third-energy ion dumps were observed, suggesting that extraction of D{sub 2}+ and D{sub 3}+ are primarily from the edge of the ion source. If extraction of half-energy ions is from the edge of the accelerator, a divergence parallel to the grid rails of 0.6{degrees}{plus minus}0.1{degrees} results. It is postulated that a nonuniform gas profile near the accelerator is the cause of the hollow partial-energy ion profiles; the pressure being depressed over the accelerator by particles passing through this highly transparent structure. Primary electrons reaching the accelerator produce nonuniform densities of D{sub 2}+ through the ionization of this across the full-energy dump was examined as a means of reducing the power density. By unbalancing the current in the two coils of the magnet, on a shot by shot basis, by up to 2:1 ratio, it was possible to move the centerline of the full-energy ion beam sideways by {approximately}12.5 cm. The adoption of such a technique, with a ramp of the coil imbalance from 2:1 to 1:2 over a beam pulse, could reduce the power density by a factor of {ge}1.5.

  3. Normalized velocity profiles of field-measured turbidity currents

    USGS Publications Warehouse

    Xu, Jingping

    2010-01-01

    Multiple turbidity currents were recorded in two submarine canyons with maximum speed as high as 280 cm/s. For each individual turbidity current measured at a fixed station, its depth-averaged velocity typically decreased over time while its thickness increased. Some turbidity currents gained in speed as they traveled downcanyon, suggesting a possible self-accelerating process. The measured velocity profiles, first in this high resolution, allowed normalizations with various schemes. Empirical functions, obtained from laboratory experiments whose spatial and time scales are two to three orders of magnitude smaller, were found to represent the field data fairly well. The best similarity collapse of the velocity profiles was achieved when the streamwise velocity and the elevation were normalized respectively by the depth-averaged velocity and the turbidity current thickness. This normalization scheme can be generalized to an empirical function Y = exp(–αXβ) for the jet region above the velocity maximum. Confirming theoretical arguments and laboratory results of other studies, the field turbidity currents are Froude-supercritical.

  4. Measurement of multipath delay profile in land mobile satellite channels

    NASA Technical Reports Server (NTRS)

    Ikegami, Tetsushi; Arakaki, Yoshiya; Wakana, Hiromitsu; Suzuki, Ryutaro

    1993-01-01

    Mobile satellite communication channel has been evaluated mainly with fading statistics of signal. When bandwidth of transmitting signal becomes wider, frequency selectivity of fading becomes a significant factor of the channel. Channel characteristics, not only signal variation but multipath delay spread should be evaluated. A multipath measurement system is proposed and developed for mobile satellite applications. With this system and ETS-V satellite, multipath delay profiles are measured in various environments including Tokyo metropolis and Sapporo city at 1.5 GHz. Results show that the maximum excess delay is within 1 microsec and the maximum delay spread is 0.2 microsecs at elevation angles of 40 to 47 degrees. In wideband signal transmission of about 1 MHz and more, designers should consider the effect of selective fading due to the multipath of land mobile satellite channel.

  5. Acoustical sensory profiles: The bridge between measurements and preference

    NASA Astrophysics Data System (ADS)

    Lyon, Richard H.

    2002-11-01

    Our judgments about all kinds of sounds depend on the sound itself and also on our experience, situational context, and expectation. The response is multimodal in that vibration, colors, temperature, and other environmental factors have an influence on our reactions. In the limited area of product sounds there has been an effort to relate consumer judgments to measurements through the use of descriptive words to create an ''Acoustical Sensory Profile'' or ASP, particularly for products that have sound as a primary feature. Examples include musical instruments, audio products, and concert halls. More recently, other products for which sound is an ancillary feature have been evaluated using ASPs. This presentation discusses this background and projects the use of ASPs, and their relationship to physical measurements and consumer judgments in particular.

  6. Characterization of a traceable profiler instrument for areal roughness measurement

    NASA Astrophysics Data System (ADS)

    Thomsen-Schmidt, P.

    2011-09-01

    A two-dimensional profiler instrument was designed and realized at the PTB (Physikalisch-Technische Bundesanstalt). The main function of the instrument is to provide traceable results in the field of roughness measurement. It is equipped with a linear moving stylus which is guided by precision air bearings. The moving part of the stylus has weight around 1 g and is carried by a magnetic field. The contacting force of the tip onto the surface under test is controlled by a small voice coil actuator in a closed control loop. Vertical movements of the stylus are captured by two different, completely independent measurement systems, covering a range of 100 µm. The first one is an interferometer, which provides a traceable signal, and the second one is an inductive measurement system. The signal from the inductive measurement system is calibrated by the interferometer. The sample under test is carried within the x-y-plane by a linear guided table with low noise air bearings. These air bearings are preloaded by vacuum and a constant gap is achieved by gas pressure controllers. Both axes of the table are driven by linear voice coil actuators and their movement in the plane is measured by linear encoders. The sample carrier is equipped with two axes tilt compensation, by which the sample under test can be levelled automatically using the measurement system of the stylus. Real-time data acquisition, manual handling and automated procedures are managed by a programmable controller and proprietary software written in LabVIEW. After measurement, data from the system can be directly transferred into the smd- or sdf-format. Results of measurements on different samples to characterize the metrological behaviour of the instrument will be reported. To characterize the uncertainty of the instrument, a model is applied, which is in accordance with approved rules for contact stylus instruments.

  7. Concentration measurement in a road tunnel as a method to assess "real-world" vehicles exhaust emissions

    NASA Astrophysics Data System (ADS)

    Zanini, G.; Berico, M.; Monforti, F.; Vitali, L.; Zambonelli, S.; Chiavarini, S.; Georgiadis, T.; Nardino, M.

    An experiment aimed at comparing particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) concentrations produced in a road tunnel by buses is described. The experiment took place in 2001 in Bologna when a couple of buses belonging to the public transport fleet where driven backwards and forwards in a road tunnel closed to all other vehicles. Buses run in the tunnel for 8 h a day for 4 experiment days, each day using a different fuel: biodiesel, diesel-water emulsion, diesel-water emulsion with low sulphur content and commercial diesel. Average daily concentrations of PM of different sizes and of 12 PHAs were measured and comparison between different fuels was attempted in order to assess "real-world" exhaust emissions of different fuels. Due to heterogeneity of experimental conditions in different days and the relatively large measurement uncertainties, the effort was only partially successful, and it was not possible to state any firm conclusion on fuels reliability even if some indications in agreement with literature were found. Nevertheless, the experiment and the data analysis method developed could be of interest as a methodological approach for future experiments aimed at evaluating "real-world" exhaust emissions of single vehicles.

  8. Lidar Aerosol Profiles Measured From Halifax During Summer 2007

    NASA Astrophysics Data System (ADS)

    Crawford, L.; Duck, T. J.; Doyle, J.; Harris, R.; Beauchamp, S.

    2007-12-01

    Measurements of aerosol profiles in the troposphere and lower stratosphere were obtained with a high-power Raman Lidar from Halifax, Nova Scotia (44.63N, 63.58W) on the East Coast of Canada during Summer 2007. Observations throughout the troposphere at high temporal resolution were made possible by using a new dual-receiver setup. The lidar was operated in clear-sky conditions, and several long duration (> 80 hours) data sets were obtained. The measurements reveal the presence of boundary-layer aerosols during episodes of pollution transport from the Eastern US and Canada, and are compared with surface measurements of ozone and other species. Boundary layer development, entrainment and mixing are evident in the data. Structured plumes at higher altitudes are traced back to biomass burning events throughout North America. Aerosols were also observed on two occasions at 15 km in altitude, and are most likely due to pyroconvection. The measurements are being used to help understand transport and mixing processes, and to form a climatology of aerosol export from North America during the summer months.

  9. Tropospheric Wind Profile Measurements with a Direct Detection Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Korb, C. Laurence; Chen, Huailin; Mathur, Savyasachee

    1998-01-01

    Research has established the importance of global tropospheric wind measurements for large scale improvements in numerical weather prediction. In addition, global wind measurements provide data that are fundamental to the understanding and prediction of global climate change. These tasks are closely linked with the goals of the NASA Earth Science Enterprise and Global Climate Change programs. NASA Goddard has been actively involved in the development of direct detection Doppler lidar methods and technologies to meet the wind observing needs of the atmospheric science community. In this paper we describe a recently developed prototype wind lidar system using a direct detection Doppler technique for measuring wind profiles from the surface through the troposphere. This system uses a pulsed ND:YAG laser operating at 1064 nm as the transmitter. The laser pulse is directed to the atmosphere using a 40 cm diameter scan mirror. The portion of the laser energy backscattered from aerosols and molecules is collected by a 40 cm diameter telescope and coupled via fiber optics into the Doppler receiver. Single photon counting APD's are used to detect the atmospheric backscattered signal. The principle element of the receiver is a dual bandpass tunable Fabry Perot etalon which analyzes the Doppler shift of the incoming laser signal using the double edge technique. The double edge technique uses two high resolution optical filters having bandpasses offset relative to one another such that the 'edge' of the first filter's transmission function crosses that of the second at the half power point. The outgoing laser frequency is located approximately at the crossover point. Due to the opposite going slopes of the edges, a Doppler shift in the atmospheric backscattered laser frequency produces a positive change in signal for one filter and a negative change in the second filter. Taking the ratio of the two edge channel signals yields a result which is directly proportional to the

  10. On Machine Capacitance Dimensional and Surface Profile Measurement System

    NASA Technical Reports Server (NTRS)

    Resnick, Ralph

    1993-01-01

    A program was awarded under the Air Force Machine Tool Sensor Improvements Program Research and Development Announcement to develop and demonstrate the use of a Capacitance Sensor System including Capacitive Non-Contact Analog Probe and a Capacitive Array Dimensional Measurement System to check the dimensions of complex shapes and contours on a machine tool or in an automated inspection cell. The manufacturing of complex shapes and contours and the subsequent verification of those manufactured shapes is fundamental and widespread throughout industry. The critical profile of a gear tooth; the overall shape of a graphite EDM electrode; the contour of a turbine blade in a jet engine; and countless other components in varied applications possess complex shapes that require detailed and complex inspection procedures. Current inspection methods for complex shapes and contours are expensive, time-consuming, and labor intensive.

  11. EPA GHG Certification of Medium- and Heavy-Duty Vehicles: Development of Road Grade Profiles Representative of US Controlled Access Highways

    SciTech Connect

    Wood, Eric; Duran, Adam; Burton, Evan; Gonder, Jeffrey; Kelly, Kenneth

    2015-05-12

    This report includes a detailed comparison of the TomTom national road grade database relative to a local road grade dataset generated by Southwest Research Institute and a national elevation dataset publically available from the U.S. Geological Survey. This analysis concluded that the TomTom national road grade database was a suitable source of road grade data for purposes of this study.

  12. Real-world operation conditions and on-road emissions of Beijing diesel buses measured by using portable emission measurement system and electric low-pressure impactor.

    PubMed

    Liu, Zhihua; Ge, Yunshan; Johnson, Kent C; Shah, Asad Naeem; Tan, Jianwei; Wang, Chu; Yu, Linxiao

    2011-03-15

    On-road measurement is an effective method to investigate real-world emissions generated from vehicles and estimate the difference between engine certification cycles and real-world operating conditions. This study presents the results of on-road measurements collected from urban buses which propelled by diesel engine in Beijing city. Two widely used Euro III emission level buses and two Euro IV emission level buses were chosen to perform on-road emission measurements using portable emission measurement system (PEMS) for gaseous pollutant and Electric Low Pressure Impactor (ELPI) for particulate matter (PM) number emissions. The results indicate that considerable discrepancies of engine operating conditions between real-world driving cycles and engine certification cycles have been observed. Under real-world operating conditions, carbon monoxide (CO) and hydrocarbon (HC) emissions can easily meet their respective regulations limits, while brake specification nitrogen oxide (bsNO(x)) emissions present a significant deviation from its corresponding limit. Compared with standard limits, the real-world bsNO(x) emission of the two Euro III emission level buses approximately increased by 60% and 120% respectively, and bsNO(x) of two Euro IV buses nearly twice standard limits because Selective Catalytic Reduction (SCR) system not active under low exhaust temperature. Particle mass were estimated via particle size distribution with the assumption that particle density and diameter is liner. The results demonstrate that nanometer size particulate matter make significant contribution to total particle number but play a minor role to total particle mass. It is suggested that specific certified cycle should be developed to regulate bus engines emissions on the test bench or use PEMS to control the bus emissions under real-world operating conditions.

  13. Temperature Profile Measurements During Heat Treatment of BSCCO 2212 Coils

    SciTech Connect

    Tollestrup, Alvin; /Fermilab

    2011-04-14

    The temperature profile of two different BSCCO 2212 coils has been analyzed. The profiles are obtained from thermocouples imbedded in the windings during the heat treatment that activates the 2212. The melting and freezing of the 2212 is clearly observed. A model that describes the data and can be used to guide the processing of new coils has been developed. We have obtained the thermal history of two BSCCO coils, one from NHMFL (1) that had 10 layers of 1 mm diameter wire with 0.15 mm insulation and a second coil from OST that had 24 layers with similar insulation and conductor size. Both coils had thermocouples imbedded in the windings and excellent recordings of the temperature over the whole reaction cycle were available for analysis. There are several features that we will address in this note. Measurements have shown that the I{sub c} of the conductor is a sensitive function of its thermal history. This brings up the question of the absolute accuracy of the thermometry in the range around 882 C, the MP of 2212. The reference for the treatment profile is really related to this MP and to small deviations around it. Since the heat of fusion of 2212 is rather large, it generates a clear signal during the melting and cooling transition that automatically generates the relative temperature markers. The physics is the same as the way ice in water maintains an isothermal environment until it is all melted. A related question is the thermal response time of the coil package. The temperature cycles that are being used to optimize strand and small coils can have rapid changes easily implemented whereas a large coil may have such a large thermal time constant that the optimum cycle may not be attainable. A simple analytical model that works well for small solenoids has been developed and an ANSYS (5) program that works for larger coils with more complicated geometry has been set up but will not be discussed in this note.

  14. Radiation profiles measured through clouds using a return glider radiosonde

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf; Kivi, Rigel

    2016-04-01

    With new and improved radiation sensors in a small glider aircraft vertical flights through clouds have been conducted. This new Return Glider Radiosonde (RG-R) is lifted up with double balloon technique to keep the radiation instruments as horizontal as possible during ascent. The RG-R is equipped with a routine radiosonde to transmit the data to a ground station and an autopilot to fly the glider radiosonde back to the launch site, where it lands autonomous with a parachute. The RG-R was successfully tested and deployed for tropospheric and stratospheric radiation measurements up to 30 hPa (24 km altitude) at the GRUAN sites Payerne (Switzerland) and Sodankylä (Finland). Radiation profiles and the radiation budget through the atmosphere during different daytimes and under cloud-free and cloudy situations will be shown in relation to temperature and humidity at the surface and in the atmosphere. The RG-R flight characteristics and new measurement possibilities will also be discussed.

  15. Cylindrical surface profile and diameter measuring tool and method

    NASA Technical Reports Server (NTRS)

    Currie, James R. (Inventor); Kissel, Ralph R. (Inventor); Smith, Earnest C. (Inventor); Oliver, Charles E. (Inventor); Redmon, John W., Sr. (Inventor); Wallace, Charles C. (Inventor); Swanson, Charles P. (Inventor)

    1987-01-01

    A tool is shown having a cross beam assembly made of beams joined by a center box structure. The assembly is adapted to be mounted by brackets to the outer end of a cylindrical case. The center box structure has a vertical shaft rotatably mounted therein and extending beneath the assembly. Secured to the vertical shaft is a radius arm which is adapted to rotate with the shaft. On the longer end of the radius arm is a measuring tip which contacts the cylindrical surface to be measured and which provides an electric signal representing the radius of the cylindrical surface from the center of rotation of the radius arm. An electric servomotor rotates the vertical shaft and an electronic resolver provides an electric signal representing the angle of rotation of the shaft. The electric signals are provided to a computer station which has software for its computer to calculate and print out the continuous circumference profile of the cylindrical surface, and give its true diameter and the deviations from the ideal circle.

  16. Cylindrical surface profile and diameter measuring tool and method

    NASA Technical Reports Server (NTRS)

    Currie, James R. (Inventor); Kissel, Ralph R. (Inventor); Oliver, Charles E. (Inventor); Smith, Earnest C. (Inventor); Redmon, John W. (Inventor); Wallace, Charles C. (Inventor); Swanson, Charles P. (Inventor)

    1989-01-01

    A tool is shown having a cross beam assembly (15) made of beams (18, 19, 20, 21) joined by a center box structure (23). The assembly (15) is adapted to be mounted by brackets (16) to the outer end of a cylindrical case (11). The center box structure (23) has a vertical shaft (25) rotatably mounted therein and extending beneath the assembly (15). Secured to the vertical shaft (25) is a radius arm (28) which is adapted to rotate with shaft (25). On the longer end of the radius arm (28) is a measuring tip (30) which contacts the cylindrical surface to be measured and which provides an electric signal representing the radius of the cylindrical surface from the center of rotation of the radius arm (28). An electric servomotor (49) rotates the vertical shaft (25) and an electronic resolver (61) provides an electric signal representing the angle of rotation of the shaft (25). The electric signals are provided to a computer station (73) which has software for its computer to calculate and print out the continuous circumference profile of the cylindrical surface, and give its true diameter and the deviations from the ideal circle.

  17. Velocity Profile Normalization of Field-Measured Turbidity Currents

    NASA Astrophysics Data System (ADS)

    Xu, J.

    2009-05-01

    Multiple occurrences of turbidity currents were observed in moored-ADCP measurements in Monterey (2002/03) and Hueneme (2007/08) submarine canyons, California. These turbidity currents, almost all of which were supercritical (densimetric Froude number greater than unity), lasted for hours and obtained a maximum speed of greater than 200 cm/s. The layer-averaged velocity of the turbidity currents varied from 100+ cm/s at the onset of the turbidity currents to 20+ cm/s toward the end of the events. The thickness of the turbidity currents tended to increase from 10 to 40 m over an event. Empirical functions, obtained from laboratory experiments whose spatial and time scales are two to three orders of magnitude smaller than the field measurements [e.g. Altinakar, Graf, and Hopfinger, 1996, Flow structure in turbidity currents, Journal of Hydraulic Research, 34(5):713-718], were found to represent the field data fairly well. However, the best similarity collapse of the turbidity current velocity profiles was obtained when the streamwise velocity was normalized by the layer-averaged velocity and the elevation was normalized by the turbidity current thickness. This normalization scheme can be generalized to the same empirical function y = exp (-α xm) for the jet region above the velocity maximum.

  18. Road tunnel, roadside, and urban background measurements of aliphatic compounds in size-segregated particulate matter

    NASA Astrophysics Data System (ADS)

    Alves, Célia A.; Oliveira, César; Martins, Natércia; Mirante, Fátima; Caseiro, Alexandre; Pio, Casimiro; Matos, Manuel; Silva, Hugo F.; Oliveira, Cristina; Camões, Filomena

    2016-02-01

    Particulate matter samples were collected in a road tunnel in Lisbon (PM0.5, PM0.5-1, PM1-2.5, and PM2.5-10) and at two urban locations representing roadside and background stations (PM2.5 and PM2.5-10). Samples were analysed for organic and elemental carbon (OC and EC), n-alkanes, n-alkenes, hopanes, some isoprenoid compounds, and steranes. Particulate matter concentrations in the tunnel were 17-31 times higher than at roadside in the vicinity, evidencing an aerosol origin almost exclusively in fresh vehicle emissions. PM0.5 in the tunnel comprised more than 60% and 80% of the total OC and EC mass in PM10, respectively. Concentrations of the different aliphatic groups of compounds in the tunnel were up to 89 times higher than at roadside and 143 times higher than at urban background. Based on the application of hopane-to-OC or hopanes-to-EC ratios obtained in the tunnel, it was found that vehicle emissions are the dominant contributor to carbonaceous particles in the city but do not represent the only source of these triterpenic compounds. Contrary to what has been observed in other studies, the Σhopane-to-EC ratios were higher in summer than in winter, suggesting that other factors (e.g. biomass burning, dust resuspension, and different fuels/engine technologies) prevail in relation to the photochemical decay of triterpenoid hydrocarbons from vehicle exhaust.

  19. Evaluation of the use of bioethanol fuelled buses based on ambient air pollution screening and on-road measurements.

    PubMed

    López-Aparicio, S; Hak, C

    2013-05-01

    Mitigation measures to reduce greenhouse gas emissions may have adverse effects on urban air quality and human exposure to harmful pollutants. The use of bioethanol fuelled vehicles is increasing worldwide and may create new undesired pollution effects. Different measurement campaigns were performed in a pilot study to contribute to the understanding of the consequences associated with the use of bioethanol blended fuel (E95) on a series of pollutants. Ambient screening measurements of NO2, O3, acetic acid, formaldehyde and acetaldehyde were performed at different urban locations, exposed and not exposed to the circulation of bioethanol buses. In addition, volatile organic compounds were measured at the exhaust pipe of a bioethanol fuelled bus, both under idling conditions (carbonyls; DNPH cartridge) and under on-road driving conditions applying online monitoring (PTR-TOF). Higher ambient acetaldehyde values were measured at locations exposed to bioethanol fuelled buses than at locations not exposed, and very high acetaldehyde and acetic acid values were measured from the exhaust pipe during driving conditions (acetaldehyde>150 ppm; acetic acid ≈ 20-30 ppm) and modelled at close distance to the bioethanol bus. Human exposure to high concentration of acetaldehyde is expected, and it may involve a significantly increased chance in developing cancer. The high concentration of acetic acid will involve odour annoyance and significant material degradation or corrosion. PMID:23500397

  20. Simultaneous measurement of internal and external profiles using a ring beam device

    NASA Astrophysics Data System (ADS)

    Wakayama, Toshitaka; Yoshizawa, Toru

    2008-08-01

    A ring beam device consisting of a conical mirror and a LD is available to form a disk-like beam sheet. We have shown measurement result of an inner diameter of pipes and holes and have developed a compact inner profile measuring instrument up to now. The ring beam device and a miniature CCD camera are incorporated in a glass tube. Validity of this instrument was shown by checking the inner profile of the references. In response to this trial, there appeared a strong request that not only an internal but also external inspection should be measured. Surely the pattern projection method conventionally used in 3D profile measurement may be useful for high speed and high precision measurement of various objects, but it is not always appropriate to measure an object with steeply inclined surface profile such as a bevel gear. In this paper, we propose a method for measurement of the external profile in addition to the internal profile. In our arrangement, one pair of concaved conical mirrors is used for the external profile measurement. When combined with our inner profile measurement method, simultaneous measurement of the inner and outer profiles becomes possible. A measurement result on a bevel gear showed availability of our proposal. We are aiming to realize simultaneous measurement of the internal and external profiles.

  1. Haul road dust control

    SciTech Connect

    Reed, W.R.; Organiscak, J.A.

    2007-10-15

    A field study was conducted to measure dust from haul trucks at a limestone quarry and a coal preparation plant waste hauling operation. The study found that primarily wind, distance and road treatment conditions notably affected the dust concentrations at locations next to, 50 ft from, and 100 ft away from the unpaved haulage road. Airborne dust measured along the unpaved haul road showed that high concentrations of fugitive dust can be generated with these concentrations rapidly decreasing to nearly background levels within 100 ft of the road. Instantaneous respirable dust measurements illustrated that the trucks generate a real-time dust cloud that has a peak concentration with a time-related decay rate as the dust moves past the sampling locations. The respirable dust concentrations and peak levels were notably diminished as the dust cloud was transported, diluted, and diffused by the wind over the 100 ft distance from the road. Individual truck concentrations and peak levels measured next to the dry road surface test section were quite variable and dependent on wind conditions, particularly wind direction, with respect to reaching the sampling location. The vast majority of the fugitive airborne dust generated from unpaved and untreated haulage roads was non-respirable. 6 figs.

  2. Delta Ray Road Trip: Measuring δ13C, δ18O and concentration of CO2 across Canada

    NASA Astrophysics Data System (ADS)

    Jost, Hansjurg; Stow, Peter; Mandic, Luka

    2016-04-01

    The Delta Ray Road Trip was conceived to demonstrate that there is now an instrument capable of being taken to the sample collection point and in fact taken to the samples along an 8000 km route across Canada. The concept was to drive a Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer from coast to coast across the 2nd largest country in the world. This route took the Delta Ray from a coastal environment, through forests, arable farm land, urban and industrial centres, across prairies and over mountains. The vehicle was a standard RV with as few modifications as possible. Along the way there were stops at most of the major universities in Canada as well as the AGU-GAC-MAC conference in Montreal, where indoor measurements were performed. Date was uploaded in quasi realtime to a website. We will present data acquired during the trip and discuss the lessons learned.

  3. Line Profile Measurements of the Lunar Exospheric Sodium

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J.; Mierkiewicz, Edwin J.; Line, Michael R.; Roesler, Fred L.; Lupie, Olivia L.

    2012-01-01

    We report ongoing results of a program to measure the lunar sodium exospheric line profile from near the lunar limb out to two lunar radii (approx 3500 km). These observations are conducted from the National Solar Observatory McMath-Pierce telescope using a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,600 (1.7 km/s) to measure line widths and velocity shifts of the Na D2 (5889 950 A) emission line in equatorial and polar regions at different lunar phases. The typical field of view (FOV) is 3 arcmin (approx 360 km) with an occasional smaller 1 arcmin FOV used right at the limb edge. The first data were obtained from full Moon to 3 days following full Moon (waning phase) in March 2009 as part of a demonstration run aimed at establishing techniques for a thorough study of temperatures and velocity variations in the lunar sodium exosphere. These data indicate velocity displacements from different locations off the lunar limb range between 150 and 600 m/s from the lunar rest velocity with a precision of +/- 20 to +/- 50 m/s depending on brightness. The measured Doppler line widths for observations within 10.5 arcmin of the east and south lunar limbs for observations between 5 deg and 40 deg lunar phase imply temperatures ranging decreasing from 3250 +/- 260K to 1175 +/- 150K. Additional data is now being collected on a quarterly basis since March 2011 and preliminary results will be reported.

  4. Measuring Protoplanetary Disk Gas Surface Density Profiles with ALMA

    NASA Astrophysics Data System (ADS)

    Williams, Jonathan P.; McPartland, Conor

    2016-10-01

    The gas and dust are spatially segregated in protoplanetary disks due to the vertical settling and radial drift of large grains. A fuller accounting of the mass content and distribution in disks therefore requires spectral line observations. We extend the modeling approach presented in Williams & Best to show that gas surface density profiles can be measured from high fidelity 13CO integrated intensity images. We demonstrate the methodology by fitting ALMA observations of the HD 163296 disk to determine a gas mass, M gas = 0.048 M ⊙, and accretion disk characteristic size R c = 213 au and gradient γ = 0.39. The same parameters match the C18O 2–1 image and indicate an abundance ratio [12CO]/[C18O] of 700 independent of radius. To test how well this methodology can be applied to future line surveys of smaller, lower mass T Tauri disks, we create a large 13CO 2–1 image library and fit simulated data. For disks with gas masses 3–10 M Jup at 150 pc, ALMA observations with a resolution of 0.″2–0.″3 and integration times of ∼20 minutes allow reliable estimates of R c to within about 10 au and γ to within about 0.2. Economic gas imaging surveys are therefore feasible and offer the opportunity to open up a new dimension for studying disk structure and its evolution toward planet formation.

  5. The Need for Wind Profile Measurements From Space

    NASA Astrophysics Data System (ADS)

    Källén, E.

    2008-12-01

    Measurements of atmospheric winds are inadequate in the present global observing system. Wind profiles have been stated as the most urgently needed observation type for climate studies as well as numerical weather prediction (WMO, 2004). Within the Earth Explorer programme ESA will launch a new satellite mission devoted to wind observations, the Atmospheric Dynamics Mission (ADM/Aeolus). It will provide line- of-sight wind profiles using a Doppler lidar measurement technique. An overview of the mission can be found in Stoffelen et al. (2005). The main purpose of the mission is to measure winds, in particular in tropical regions there is a serious lack of wind information. Tropical atmospheric variability is governed by the winds, with only temperature and pressure information present day weather prediction systems have difficulties in properly representing some aspects of tropical weather. One example of this is given by Kistler et al. (2001) when they compare zonally averaged wind fields from two separate re-analysis systems. It is clear that two separate re-analyses differ markedly in the tropical regions while they are quite similar in mid-latitude and polar regions. This is not due to a deficiency in any of the re-analysis models used, but can be argued to result from a lack of wind information in the tropics. Other important areas where wind observations are needed is the prediction of midlatitude storms and analysis of meridional heat transports. Vertically deep structures with a limited horizontal scale are most sensitive to wind information. The meridional heat transport in midlatitudes can be estimated from re-analysis products, but it has been found that such estimates must be bias corrected as the re-analysis fields have relatively large systematic errors in the zonally averaged meridional wind field (Graversen et al., 2007). Part of this bias can be due to a lack of sufficient wind information to define the ageostrophic, zonally averaged meridional wind

  6. Method and apparatus for measuring irradiated fuel profiles

    DOEpatents

    Lee, D.M.

    1980-03-27

    A new apparatus is used to substantially instantaneously obtain a profile of an object, for example a spent fuel assembly, which profile (when normalized) has unexpectedly been found to be substantially identical to the normalized profile of the burnup monitor Cs-137 obtained with a germanium detector. That profile can be used without normalization in a new method of identifying and monitoring in order to determine for example whether any of the fuel has been removed. Alternatively, two other new methods involve calibrating that profile so as to obtain a determination of fuel burnup (which is important for complying with safeguards requirements, for utilizing fuel to an optimal extent, and for storing spent fuel in a minimal amount of space).

  7. The road towards accurate optical width measurements at the industrial level

    NASA Astrophysics Data System (ADS)

    Bodermann, Bernd; Köning, Rainer; Bergmann, Detlef; Buhr, Egbert; Hässler-Grohne, Wolfgang; Flügge, Jens; Bosse, Harald

    2013-04-01

    Optical vision systems require both unidirectional and bidirectional measurements for the calibrations and the verification of the tool performance to enable accurate measurements traceable to the SI unit Metre. However, for bidirectional measurements up to now the national metrology institutes are unable to provide internationally recognized calibrations of suitable standards. Furthermore often users are not aware of the specific difficulties of these measurements. In this paper the current status and limitations of bidirectional optical measurements at the industrial level are summarised and compared to state-of-the-art optical linewidth measurements performed at PTB on measurement objects of semiconductor industry. It turns out, that for optical widths measurements at an uncertainty level below 1 μm edge localisation schemes are required, which are based on tool and sample dependent threshold values, which usually need to be determined by a rigorous simulation of the microscopic image. Furthermore the calibration samples and structures must have a sufficient quality, e. g. high edge angle and low edge roughness and the structure materials and their material parameters have to be known. The experience obtained within the accreditation process of industrial labs for width calibrations shows that, in order to be able to achieve a desired measurement uncertainties of about 100 nm, the imaging system needs to have a monochromatic Koehler illumination, numerical aperture larger than 0.5, a magnification greater than 50x and the ability to control the deviation of the focus position to better than 100 nm.

  8. Measurement of inner and/or outer profiles of pipes using ring beam devices

    NASA Astrophysics Data System (ADS)

    Wakayama, T.; Yoshizawa, T.

    2009-11-01

    Inner profile measurement is an important matter in such fields as medicine, dentistry and anthropology as well as mechanical engineering and industry. Here we propose a measurement method for inner diameter of pipes and/or holes. The key device in this technique is a ring beam device which consists of a conical mirror and a laser diode. And the fundamental principle is based on optical sectioning without any contact probe. The optically sectioned profile of an inner wall of a pipe-like object is analyzed to give the inner profile in addition to the inner diameter. This optical instrument with a simple and small configuration is now under development for practical uses. In the hitherto-tried experimental works, the availability of this instrument has been highly evaluated and usability for practical applications is expected, especially, for measurement and inspection of mechanical components and elements besides pipes. This ring beam device consisting of a conical mirror and a LD is assembled to form a disklike light beam sheet. We show measurement result of pipes and holes, and, at the same time, report a compact inner profile measuring instrument. Both the ring beam device and a miniaturized CCD camera are fabricated in a glass tube. Availability of this instrument is shown by measuring the inner profiles of various pipes. In response to this trial, there appeared a strong request that not only the internal but external profiles should be measured simultaneously. Therefore we propose an improved method for measuring the external profile in addition to the internal profile. In our arrangement, one pair of concaved conical mirrors is used for the external profile measurement. In combination with the inner profile measurement technique, simultaneous measurement of the inner and outer profiles becomes attainable. A measurement result on a bevel gear shows availability of newly proposed principle. Now we are aiming to realize simultaneous measurement of the internal

  9. On-Road Measurements of NO2 /NOx and NOx / CO Vehicle Emission Ratios in Colorado Summer Traffic

    NASA Astrophysics Data System (ADS)

    Wild, R. J.; Peischl, J.; Ryerson, T. B.; Neuman, J. A.; Dube, W. P.; Brown, S. S.

    2014-12-01

    Emissions of nitrogen oxides (NO and NO2) from vehicles are important precursors to ozone (O3) formation, and thus contribute to environmental and health issues. Both carbon dioxide (CO2) and carbon monoxide (CO) are large emissions from combustion, with the former a marker for total fuel consumption and the latter a commonly used combustion tracer. Thus, measurements of NOx to CO and CO2 emission ratios form an important part of characterizing total vehicle NOx emissions. Vehicle NOx emissions are primarily in the form of NO, although the NO2 content of these emissions may be changing as a result of control technology implementation, particularly for Diesel engines. Characterization of direct NO2 emission factors (i.e., NO2 to NOx ratio) is important because NO2 produces ozone upon its photolysis, while NO emission titrates ozone near sources. NO + O3 → NO2 + O2NO2 + hν (+ O2) → NO + O3Higher NO2 to NO emission ratios will likely result in higher ozone levels per unit NOx emitted. Higher NO2 emission ratios also lead to ozone production in closer proximity to the emission sources. There is a substantial lack of top-down measurements to assess emission inventories. Here we present an analysis of on-road measurements of vehicular emissions. We simultaneously measured NO, NO2 and O3 with a shared inlet at 20 pptv/s precision using a custom-built cavity ring-down measurement system in an instrumented van, together with high time resolution measurements of CO and CO2. Measurements were performed while driving throughout the Colorado Front Range urban area. We present a statistical analysis of vehicle plumes and their corresponding emissions ratios that can be used to constrain the direct emission ratio of NO2 in NOx, and NOx emission factors relative to CO and CO2.

  10. On-road measurement of NH3 and N2O emissions from a Euro V heavy-duty vehicle

    NASA Astrophysics Data System (ADS)

    Suarez-Bertoa, Ricardo; Mendoza-Villafuerte, Pablo; Bonnel, Pierre; Lilova, Velizara; Hill, Leslie; Perujo, Adolfo; Astorga, Covadonga

    2016-08-01

    The use of selective catalytic reduction systems (SCR) to abate NOx vehicular emissions brings new concerns on the emissions of the byproducts NH3 and N2O. Therefore, NH3 and N2O on-road emissions from a Euro V truck equipped with a SCR were measured in real time using a QCL-IR. Results bring to light possibility to perform this kind of real time measurements for other pollutants besides, hydrocarbons, NOx, CO and CO2. The capability to measure NH3 and N2O in a second-by-second basis will allow applying the currently agreed regulatory emissions evaluation for gaseous compounds. Average N2O emission factors calculated applying the current PEMS-based data analysis to all available windows from the tests ranged from 0.063 g/kWh to 0.139 g/kWh. Average NH3 concentrations ranged from 0.9 ppm to 5.7 ppm. Although calculated average N2O and NH3 emissions were within current limits, NOx emissions were substantially higher than Euro V limits under the studied conditions.

  11. Monitoring training status with HR measures: do all roads lead to Rome?

    PubMed

    Buchheit, Martin

    2014-01-01

    Measures of resting, exercise, and recovery heart rate are receiving increasing interest for monitoring fatigue, fitness and endurance performance responses, which has direct implications for adjusting training load (1) daily during specific training blocks and (2) throughout the competitive season. However, these measures are still not widely implemented to monitor athletes' responses to training load, probably because of apparent contradictory findings in the literature. In this review I contend that most of the contradictory findings are related to methodological inconsistencies and/or misinterpretation of the data rather than to limitations of heart rate measures to accurately inform on training status. I also provide evidence that measures derived from 5-min (almost daily) recordings of resting (indices capturing beat-to-beat changes in heart rate, reflecting cardiac parasympathetic activity) and submaximal exercise (30- to 60-s average) heart rate are likely the most useful monitoring tools. For appropriate interpretation at the individual level, changes in a given measure should be interpreted by taking into account the error of measurement and the smallest important change of the measure, as well as the training context (training phase, load, and intensity distribution). The decision to use a given measure should be based upon the level of information that is required by the athlete, the marker's sensitivity to changes in training status and the practical constrains required for the measurements. However, measures of heart rate cannot inform on all aspects of wellness, fatigue, and performance, so their use in combination with daily training logs, psychometric questionnaires and non-invasive, cost-effective performance tests such as a countermovement jump may offer a complete solution to monitor training status in athletes participating in aerobic-oriented sports.

  12. Monitoring training status with HR measures: do all roads lead to Rome?

    PubMed Central

    Buchheit, Martin

    2014-01-01

    Measures of resting, exercise, and recovery heart rate are receiving increasing interest for monitoring fatigue, fitness and endurance performance responses, which has direct implications for adjusting training load (1) daily during specific training blocks and (2) throughout the competitive season. However, these measures are still not widely implemented to monitor athletes' responses to training load, probably because of apparent contradictory findings in the literature. In this review I contend that most of the contradictory findings are related to methodological inconsistencies and/or misinterpretation of the data rather than to limitations of heart rate measures to accurately inform on training status. I also provide evidence that measures derived from 5-min (almost daily) recordings of resting (indices capturing beat-to-beat changes in heart rate, reflecting cardiac parasympathetic activity) and submaximal exercise (30- to 60-s average) heart rate are likely the most useful monitoring tools. For appropriate interpretation at the individual level, changes in a given measure should be interpreted by taking into account the error of measurement and the smallest important change of the measure, as well as the training context (training phase, load, and intensity distribution). The decision to use a given measure should be based upon the level of information that is required by the athlete, the marker's sensitivity to changes in training status and the practical constrains required for the measurements. However, measures of heart rate cannot inform on all aspects of wellness, fatigue, and performance, so their use in combination with daily training logs, psychometric questionnaires and non-invasive, cost-effective performance tests such as a countermovement jump may offer a complete solution to monitor training status in athletes participating in aerobic-oriented sports. PMID:24578692

  13. Black carbon, particle number concentration and nitrogen oxide emission factors of random in-use vehicles measured with the on-road chasing method

    NASA Astrophysics Data System (ADS)

    Ježek, I.; Katrašnik, T.; Westerdahl, D.; Močnik, G.

    2015-06-01

    The chasing method was used in an on-road measurement campaign, and emission factors (EF) of black carbon (BC), particle number (PN) and nitrogen oxides (NOx) were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years, decreased by 60 and 47% from those in use for 5-10 years, respectively, the median NOx and PN EFs, of goods vehicles that were in use for less than five years, decreased from those in use for 5-10 years by 52 and 67%, respectively. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25% of emitting diesel cars contributed 63, 47 and 61% of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements with sophisticated post processing individual vehicles EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and monitor how the numerous emission reduction approaches are reflected in on-road driving conditions.

  14. Applying velocity profiling technology to flow measurement at the Orinda water treatment plant

    SciTech Connect

    Metcalf, M.A.; Kachur, S.; Lackenbauer, S.

    1998-07-01

    A new type of flow measurement technology, velocity profiling, was tested in the South Channel of the Orinda Water Treatment Plant. This new technology allowed installation in the difficult hydraulic conditions of the South Channel, without interrupting plant operation. The advanced technology of velocity profiling enables flow measurements to be obtained in sites normally unusable by more traditional methods of flow rate measurement.

  15. Profile measurement of aspheric surfaces using scanning deflectometry and rotating autocollimator with wide measuring range

    NASA Astrophysics Data System (ADS)

    Ishikawa, Kyohei; Takamura, Tomohiko; Xiao, Muzheng; Takahashi, Satoru; Takamasu, Kiyoshi

    2014-06-01

    High-accuracy aspherical mirrors and lenses with large dimensions are widely used in large telescopes and other industry fields. However, the measurement methods for large aspherical optical surfaces are not well established. Scanning deflectometry is used for measuring optical signals near flat surfaces with uncertainties on subnanometer scales. A critical issue regarding scanning deflectometry is that high-accuracy autocollimators (AC) have narrow angular measuring ranges and are not suitable for measuring surfaces with large slopes and angular changes. The goal of our study is to measure the profile of large aspherical optical surfaces with an accuracy of approximately 10 nm. We have proposed a new method to measure optical surfaces with large aspherical dimensions and large angular changes by using a scanning deflectometry method. A rotating AC was used to increase the allowable measuring range. Error analysis showed that the rotating AC reduces the accuracy of the measurements. In this study, we developed a new AC with complementary metal-oxide semiconductor (CMOS) as a light-receiving element (CMOS-type AC). The CMOS-type AC can measure wider ranges of angular changes, with a maximum range of 21 500 µrad (4500 arcsec) and a stability (standard deviation) of 0.1 µrad (0.02 arcsec). We conducted an experiment to verify the effectivity of the wide measuring range AC by the measurement of a spherical mirror with a curvature radius of 500 mm. Furthermore, we conducted an experiment to measure an aspherical optical surface (an off-axis parabolic mirror) and found an angular change of 0.07 rad (4 arcdegrees). The repeatability (average standard deviation) for ten measurements of the off-axis parabolic mirror was less than 4 nm.

  16. On-Road Measurement of Exhaust Emission Factors for Individual Diesel Trucks

    NASA Astrophysics Data System (ADS)

    Dallmann, T. R.; DeMartini, S.; Harley, R. A.; Kirchstetter, T. W.; Wood, E. C.; Onasch, T. B.; Herndon, S. C.

    2011-12-01

    Diesel trucks are an important source of primary fine particulate matter (PM2.5) that includes black carbon (BC) as a major component. More stringent exhaust emission standards for new engines, effective starting in 2007, considerably reduce allowable emissions and have led to use of after-treatment control devices such as diesel particle filters. The state of California is also implementing programs to accelerate replacement or retrofit of older trucks. In light of these changes, measurements of emissions from in-use heavy-duty diesel trucks are timely and needed to understand the impact of new control technologies on emissions. PM2.5, BC mass, particle light absorption, and particle light extinction emission factors for hundreds of individual diesel trucks were measured in this study. Emissions were measured in July 2010 from trucks driving through the Caldecott tunnel in the San Francisco Bay area. Gas-phase emissions including nitric oxide, nitrogen dioxide, carbon monoxide, and carbon dioxide (CO2) were also measured. Pollutants were measured using air sampling inlets located directly above the vertical exhaust stacks of heavy-duty trucks driving by on the roadway below. All of these measurements were made using fast time response (1 Hz) sensors. Particle optical properties were simultaneously characterized with direct measurements of absorption (babs) and extinction (bext) coefficients. Emission factors for individual trucks were calculated using a carbon balance method in which emissions of PM2.5, BC, babs, and bext in each exhaust plume were normalized to emissions of CO2. Emission factor distributions and fleet-average values are quantified. Absorption and extinction emission factors are used to calculate the aerosol single scattering albedo and BC mass absorption efficiency for individual truck exhaust plumes.

  17. On-road measurement of carbonyls in California light-duty vehicle emissions.

    PubMed

    Kean, A J; Grosjean, E; Grosjean, D; Harley, R A

    2001-11-01

    Emissions of carbonyls by motor vehicles are of concern because these species can be hazardous to human health and highly reactive in the atmosphere. The objective of this research was to measure carbonyl emission factors for California light-duty motor vehicles. Measurements were made at the entrance and exit of a San Francisco Bay area highway tunnel, in the center bore where heavy-duty trucks are not allowed. During summer 1999, approximately 100 carbonyls were identified, including saturated aliphatic aldehydes and ketones, unsaturated aliphatic carbonyls, aliphatic dicarbonyls, and aromatic carbonyls. Concentrations were measured for 32 carbonyls and were combined with NMOC, CO, and CO2 concentrations to calculate by carbon balance emission factors per unit of fuel burned. The measured carbonyl mass emitted from light-duty vehicles was 68 +/- 4 mg L(-1). Formaldehyde accounted for 45% of the measured mass emissions, acetaldehyde 12%, tolualdehydes 10%, benzaldehyde 7.2%, and acetone 5.9%. The ozone forming potential of the carbonyl emissions was dominated by formaldehyde (70%) and acetaldehyde (14%). Between 1994 and 1999, emission factors measured at the same tunnel for formaldehyde, acetaldehyde, and benzaldehyde decreased by 45-70%. Carbonyls constituted 3.9% of total NMOC mass emissions and 5.2% of NMOC reactivity. A comparison of carbonyl emissions with gasoline composition supports previous findings that aromatic aldehyde emissions are related to aromatics in gasoline. Carbonyl concentrations in liquid gasoline were also measured. Acetone and MEK were the most abundant carbonyls in unburned gasoline; eight other carbonyls were detected and quantified.

  18. Characterizing near-road air pollution using local-scale emission and dispersion models and validation against in-situ measurements

    NASA Astrophysics Data System (ADS)

    Wang, An; Fallah-Shorshani, Masoud; Xu, Junshi; Hatzopoulou, Marianne

    2016-10-01

    Near-road concentrations of nitrogen dioxide (NO2), a known marker of traffic-related air pollution, were simulated along a busy urban corridor in Montreal, Quebec using a combination of microscopic traffic simulation, instantaneous emission modeling, and air pollution dispersion. In order to calibrate and validate the model, a data collection campaign was designed. For this purpose, measurements of NO2 were conducted mid-block along four segments of the corridor throughout a four-week campaign conducted between March and April 2015. The four segments were chosen to be consecutive and yet exhibiting variability in road configuration and built environment characteristics. Roadside NO2 measurements were also paired with on-site and fixed-station meteorological data. In addition, traffic volumes, composition, and routing decisions were collected using video-cameras located at upstream and downstream intersections. Dispersion of simulated emissions was conducted for eight time slots and under a range of meteorological conditions using three different models with vastly different dispersion algorithms (OSPM, CALINE 4, and SIRANE). The three models exhibited poor correlation with near-road NO2 concentrations and were better able to simulate average concentrations occurring along the roadways rather than the range of concentrations measured under diverse meteorological and traffic conditions. As hypothesized, the model SIRANE that can handle a street canyon configuration was the most sensitive to the built environment especially to the presence of tall buildings around the road. In contrast, CALINE exhibited the lowest sensitivity to the built environment.

  19. Effectiveness of mitigation measures in reducing future primary particulate matter emissions from on-road vehicle exhaust.

    PubMed

    Yan, Fang; Bond, Tami C; Streets, David G

    2014-12-16

    This work evaluates the effectiveness of on-road primary particulate matter emission reductions that can be achieved by long-term vehicle scrappage and retrofit measures on regional and global levels. Scenario analysis shows that scrappage can provide significant emission reductions as soon as the measures begin, whereas retrofit provides greater emission reductions in later years, when more advanced technologies become available in most regions. Reductions are compared with a baseline that already accounts for implementation of clean vehicle standards. The greatest global emission reductions from a scrappage program occur 5 to 10 years after its introduction and can reach as much as 70%. The greatest reductions with retrofit occur around 2030 and range from 16-31%. Monte Carlo simulations are used to evaluate how uncertainties in the composition of the vehicle fleet affect predicted reductions. Scrappage and retrofit reduce global emissions by 22-60% and 15-31%, respectively, within 95% confidence intervals, under a midrange scenario in the year 2030. The simulations provide guidance about which strategies are most effective for specific regions. Retrofit is preferable for high-income regions. For regions where early emission standards are in place, scrappage is suggested, followed by retrofit after more advanced emission standards are introduced. The early implementation of advanced emission standards is recommended for Western and Eastern Africa.

  20. Effectiveness of Mitigation Measures in Reducing Future Primary Particulate Matter Emissions from On-Road Vehicle Exhaust

    SciTech Connect

    Yan, Fang; Bond, Tami C.; Streets, David G.

    2014-12-16

    This work evaluates the effectiveness of on-road primary particulate matter emission reductions that can be achieved by long-term vehicle scrappage and retrofit measures on regional and global levels. Scenario analysis shows that scrappage can provide significant emission reductions as soon as the measures begin, whereas retrofit provides greater emission reductions in later years, when more advanced technologies become available in most regions. Reductions are compared with a baseline that already accounts for implementation of clean vehicle standards. The greatest global emission reductions from a scrappage program occur 5 to 10 years after its introduction and can reach as much as 70%. The greatest reductions with retrofit occur around 2030 and range from 16-31%. Monte Carlo simulations are used to evaluate how uncertainties in the composition of the vehicle fleet affect predicted reductions. Scrappage and retrofit reduce global emissions by 22-60% and 15-31%, respectively, within 95% confidence intervals, under a midrange scenario in the year 2030. The simulations provide guidance about which strategies are most effective for specific regions. Retrofit is preferable for high-income regions. For regions where early emission standards are in place, scrappage is suggested, followed by retrofit after more advanced emission standards are introduced. The early implementation of advanced emission standards is recommended for Western and Eastern Africa

  1. [Measurement of exhaust gases of cars in the neighbourhood of roads (author's transl)].

    PubMed

    Wanner, H U; Deuber, A; Satish, J; Meier, M; Sommer, H

    1976-07-01

    Air samples were collected in plastic bags simultaneously at various measuring points in the close range of streets. When examining the various bag materials, Teflon bags showed the smallest deviations in direct analyses and in analyses of up to two hours after the drawing of samples. The following methods were used for the analysis of the air samples collected in the bags: coulometry for CO and SO2, chemiluminescence for NO/NO2, chromotropic acid for CH2O and flame ionization for hydrocarbon. The various components were measured close to a highway and near streets in residential and business areas. PMID:63198

  2. Will Euro 6 reduce the NOx emissions of new diesel cars? - Insights from on-road tests with Portable Emissions Measurement Systems (PEMS)

    NASA Astrophysics Data System (ADS)

    Weiss, Martin; Bonnel, Pierre; Kühlwein, Jörg; Provenza, Alessio; Lambrecht, Udo; Alessandrini, Stefano; Carriero, Massimo; Colombo, Rinaldo; Forni, Fausto; Lanappe, Gaston; Le Lijour, Philippe; Manfredi, Urbano; Montigny, Francois; Sculati, Mirco

    2012-12-01

    The nitrogen dioxide (NO2) pollution in urban areas of Europe can be partially attributed to the increasing market penetration of diesel cars that show higher distance-specific nitrogen oxides (NOx) emissions than gasoline cars. The on-road NOx emissions of diesel cars, furthermore, appear to exceed substantially applicable emissions standards. This observation raises concerns that the introduction of more stringent Euro 6 emissions standards in 2014 may not adequately reduce the distance-specific on-road NOx emissions of new diesel cars. We address the existing concerns by analyzing the gaseous emissions of one novel Euro 6 diesel car and six Euro 4-5 diesel cars with Portable Emissions Measurement Systems (PEMS). We find that the average on-road NOx emissions of the Euro 6 car (0.21 ± 0.09 g per kilometer [g km-1]) are considerably lower than those of the Euro 4 cars (0.76 ± 0.12 g km-1) and the Euro 5 cars (0.71 ± 0.30 g km-1). The selective catalytic reduction (SCR) system of the Euro 6 diesel car is suitable to limit NOx emissions during real-world on-road driving. Still, all tested cars, including the Euro 6 diesel car, exceed their NOx emissions standards on the road by 260 ± 130%. This finding suggests that the current type-approval procedure does not adequately capture the on-road NOx emissions of diesel cars. By introducing a complementary emissions test procedure that covers a wide range of normal operating conditions, the European legislative authorities can address this problem and ensure that Euro 6 will indeed deliver an adequate reduction in the NOx emissions of new diesel cars.

  3. [GC x GC measurements of atmospheric aromatic compounds near a busy high-speed road in Beijing].

    PubMed

    Mao, Ting; Xu, Xiao-bin; Wang, Ying

    2009-10-15

    Comprehensive two-dimensional gas chromatography (GC x GC) is a powerful instrumental tool often used to analyze complex mixtures. An optimized GC x GC method had been applied to the quantitative analysis of aromatic compounds in air samples collected near a busy high-speed road in Beijing during the 2007 National Holidays. In the resulting GC x GC chromatograms, aromatic species were resolved from other compound classes and were grouped in a manner that facilitated identification and integration, showing more information of aromatic compounds compared to traditional one-dimensional GC. Totally more than 30 aromatic species were identified and quantified. The average concentrations of monocyclic aromatic compounds ranged from 0.75 x 10(-9) to 24.64 x 10(-9) C, with toluene having the highest concentration, followed by m, p-xylene and ethylbenzene. The average concentrations of the measured polycyclic aromatic compounds ranged from 0.03 x 10(-9) to 2.28 x 10(-9) C, with naphthalene having the highest concentration, followed by 2-methyl-naphthalene and 4-methyl-1, 1'-biphenyl. The four-ring and higher polycyclic aromatic compounds were not detectable in the gaseous samples. The levels of aromatic compounds were significantly influenced by meteorological parameters. Benzene and toluene were poorly correlated with higher aromatic compounds though the latter compounds were highly correlated among each other, suggesting that both were significantly influenced by sources other than vehicle exhaust and gasoline evaporation.

  4. A voice coil motor based measuring force control system for tactile scanning profiler

    NASA Astrophysics Data System (ADS)

    Feng, Shengdong; Liu, Xiaojun; Chen, Liangzhou; Zhou, Liping; Lu, Wenlong

    2015-02-01

    In tactile scanning profiler, the measuring force would change in a wide range when it was used for profile measurement in a large range, which could possibly destroy the measured surface. To solve the problem, measuring force control system for tactile scanning profiler was needed. In the paper, a voice coil motor-based measuring force control system for tactile scanning profiler was designed. In the design, a low stiffness coefficient spring was used to provide contact force, while a voice coil motor (VCM) to balance the spring force so that the contact force could be kept for constant measuring force. A VCM was designed specially, and for active measuring force control, a precision current source circuit under the control of a DSP unit was designed to drive the VCM. The performance of voice coil motor based measuring force control system had been tested, and its good characteristics were verified.

  5. The road to patient experience of care measurement: lessons from the United States

    PubMed Central

    2013-01-01

    Patient-centered care has become an increasing priority in the United States and plays a prominent role in recent healthcare reforms. One way the country has managed to advance patient-centered care is through establishment of a family of national patient experience surveys (the Consumer Assessment of Healthcare Providers and Systems Plans (CAHPS). CAHPS is publicly reported for several types of providers and was recently tied to hospital reimbursement. This is part of a trend over the last two decades that has shifted provider-patient relationships from a traditional paternal approach to customer service and then to clinical partnership. The health care system in Israel, however, is still struggling to overcome barriers to change in this area. While community based biannual patient experience surveys are conducted by the Myers-JDC-Brookdale Institute, there is no comprehensive national approach to measuring the patient experience across a broad range of settings. Only recently did the Israeli Ministry of Health take its first steps to include patient experience as a dimension of health care quality. In its current position, Israel should learn from the U.S. experience with policies promoting patient-centered care, and specifically the impact on clinical services of measuring the patient experience. Looking at what has happened in the United States, we suggest three main lessons. First, there is a need for a set of national patient experience surveys that would be publicly reported and eventually tied to provider reimbursement. Secondly, the national survey tools should be customized to the unique characteristics of Israeli society and draw from recent research on patient-centeredness to include new and important domains such as patient activation and shared decision-making. Finally, newer technological approaches should be explored with the aim of increasing response rates and the timeliness and usefulness of the surveys. PMID:24044672

  6. The road to patient experience of care measurement: lessons from the United States.

    PubMed

    Zimlichman, Eyal; Rozenblum, Ronen; Millenson, Michael L

    2013-01-01

    Patient-centered care has become an increasing priority in the United States and plays a prominent role in recent healthcare reforms. One way the country has managed to advance patient-centered care is through establishment of a family of national patient experience surveys (the Consumer Assessment of Healthcare Providers and Systems Plans (CAHPS). CAHPS is publicly reported for several types of providers and was recently tied to hospital reimbursement. This is part of a trend over the last two decades that has shifted provider-patient relationships from a traditional paternal approach to customer service and then to clinical partnership. The health care system in Israel, however, is still struggling to overcome barriers to change in this area. While community based biannual patient experience surveys are conducted by the Myers-JDC-Brookdale Institute, there is no comprehensive national approach to measuring the patient experience across a broad range of settings. Only recently did the Israeli Ministry of Health take its first steps to include patient experience as a dimension of health care quality.In its current position, Israel should learn from the U.S. experience with policies promoting patient-centered care, and specifically the impact on clinical services of measuring the patient experience. Looking at what has happened in the United States, we suggest three main lessons. First, there is a need for a set of national patient experience surveys that would be publicly reported and eventually tied to provider reimbursement. Secondly, the national survey tools should be customized to the unique characteristics of Israeli society and draw from recent research on patient-centeredness to include new and important domains such as patient activation and shared decision-making. Finally, newer technological approaches should be explored with the aim of increasing response rates and the timeliness and usefulness of the surveys.

  7. The Usability of Different Skid Resistance Characteristics in Road Assessment

    NASA Astrophysics Data System (ADS)

    Kováč, Matúš; Kotek, Peter

    2014-12-01

    The article was created as a reaction on the request of the Slovak Road Administration, whether it would be possible to evaluate level of friction on the road network only by using laser equipped device Profilograph GE, instead of by using longitudinal friction coefficient measuring device Skiddometer BV11, which is slow, much more difficult on operation and it is necessary to fulfil the water tank for measurements. In order to find out the answer, there were evaluated measurements performed on road sections in Slovakia for the past few years. The main goal was to compare results obtained by both devices, and to find a relevant correlation between them. For better understanding of the problematic and for the demonstration of disadvantages of some texture characteristics, there are performed a comparisons of the different parameters evaluated on model surface profiles in the end of this work.

  8. Dilution and aerosol dynamics within a diesel car exhaust plume—CFD simulations of on-road measurement conditions

    NASA Astrophysics Data System (ADS)

    Uhrner, U.; von Löwis, S.; Vehkamäki, H.; Wehner, B.; Bräsel, S.; Hermann, M.; Stratmann, F.; Kulmala, M.; Wiedensohler, A.

    Vehicle particle emissions are studied extensively because of their health effects, contribution to ambient PM levels and possible impact on climate. The aim of this work was to obtain a better understanding of secondary particle formation and growth in a diluting vehicle exhaust plume using 3-d information of simulations together with measurements. Detailed coupled computational fluid dynamics (CFD) and aerosol dynamics simulations have been conducted for H 2SO 4-H 2O and soot particles based on measurements within a vehicle exhaust plume under real conditions on public roads. Turbulent diffusion of soot and nucleation particles is responsible for the measured decrease of number concentrations within the diesel car exhaust plume and decreases coagulation rates. Particle size distribution measurements at 0.45 and 0.9 m distance to the tailpipe indicate a consistent soot mode (particle diameter Dp˜50 nm) at variable operating conditions. Soot mode number concentrations reached up to 10 13 m -3 depending on operating conditions and mixing. For nucleation particles the simulations showed a strong sensitivity to the spatial dilution pattern, related cooling and exhaust H 2SO 4(g). The highest simulated nucleation rates were about 0.05-0.1 m from the axis of the plume. The simulated particle number concentration pattern is in approximate accordance with measured concentrations, along the jet centreline and 0.45 and 0.9 m from the tailpipe. Although the test car was run with ultralow sulphur fuel, high nucleation particle ( Dp⩽15 nm) concentrations (>10 13 m -3) were measured under driving conditions of strong acceleration or the combination of high vehicle speed (>140 km h -1) and high engine rotational speed (>3800 revolutions per minute (rpm)). Strong mixing and cooling caused rapid nucleation immediately behind the tailpipe, so that the highest particle number concentrations were recorded at a distance, x=0.45 m behind the tailpipe. The simulated growth of H 2SO 4

  9. Surface tension profiles in vertical soap films: an intrusive measurement

    NASA Astrophysics Data System (ADS)

    Adami, Nicolas; Dorbolo, Stéphane; Caps, Hervé; Grasp Team

    2012-11-01

    Soap films are known to be the basic constituent of complex fluid objects such as bubbles and foams. In order for their weight to be counterbalanced, those objects need to exhibit vertical surface tension profiles, which can only exist due to the presence of surfactant molecules at their interfaces. We here present a method that aims to probe vertical soap films surface tension profiles by use of elasto-capillary deformations. Both cases of free-draining and entertained soap films are investigated, leading the spatio-temporal behavior of the surface tension. We show that this behavior is highly dependent on the nature of the surfactant used to create soap films, emphasizing the influence of the physico-chemistry on the global behavior of the system. We propose order of magnitude calculations, which are in good agreement with experimental data.

  10. Road Rage

    PubMed Central

    Sansone, Lori A.

    2010-01-01

    Up to one-third of community participants report being perpetrators of road rage, indicating that various forms of road rage are relatively commonplace. However, only two percent or less of incidents culminate in serious damage to persons or vehicles. The most common offenders appear to be young and male. A number of factors may contribute to road rage, including environmental factors (e.g., greater number of miles driven per day, traffic density), nonspecific psychological factors (e.g., displaced aggression, attribution of blame to others), and bona fide Axis I and II disorders. The most common Axis I disorders appear to be related to alcohol and substance misuse, whereas possible Axis II disorders include borderline and antisocial personality disorders. Being aware of these contributory factors to road rage may improve general clinical awareness of the nature and treatment of perpetrators. PMID:20805914

  11. Turbulence in planetary occultations. II - Effects on atmospheric profiles derived from Doppler measurements. III - Effects on atmospheric profiles derived from intensity measurements

    NASA Technical Reports Server (NTRS)

    Haugstad, B. S.

    1978-01-01

    The nature and magnitude of turbulence-induced errors in atmospheric profiles derived from Doppler measurements made during radio occultations are investigated. It is found that turbulence in planetary atmospheres induces both fluctuating and systematic errors in derived profiles, but the errors of both types are very small. Consideration of the occultation of Mariner 10 by Venus and of the Pioneer occultations by Jupiter shows that the rms fractional errors in the atmospheric profiles derived from these observations were less than 0.01 in both temperature and pressure, while the fractional systematic errors were typically of the order of 1 millionth. The extent to which atmospheric profiles derived from radio and optical intensity measurements are affected by turbulence is also examined. The results indicate that turbulence in planetary atmospheres has only a marginal effect on derived profiles in the weak-scattering limit and that the turbulence-induced errors in this case are always much larger than the corresponding errors in profiles derived from radio Doppler measurements.

  12. Evaluation of diesel fleet emissions and control policies from plume chasing measurements of on-road vehicles

    NASA Astrophysics Data System (ADS)

    Lau, Chui Fong; Rakowska, Agata; Townsend, Thomas; Brimblecombe, Peter; Chan, Tat Leung; Yam, Yat Shing; Močnik, Griša; Ning, Zhi

    2015-12-01

    Vehicle emissions are an important source of urban air pollution. Diesel fuelled vehicles, although constituting a relatively small fraction of fleet population in many cities, are significant contributors to the emission inventory due to their often long mileage for goods and public transport. Recent classification of diesel exhaust as carcinogenic by the World Health Organization also raises attention to more stringent control of diesel emissions to protect public health. Although various mandatory and voluntary based emission control measures have been implemented in Hong Kong, there have been few investigations to evaluate if the fleet emission characteristics have met desired emission reduction objectives and if adoption of an Inspection/Maintenance (I/M) programme has been effective in achieving these objectives. The limitations are partially due to the lack of cost-effective approaches for the large scale characterisation of fleet based emissions to assess the effectiveness of control measures and policy. This study has used a plume chasing method to collect a large amount of on-road vehicle emission data of Hong Kong highways and a detailed analysis was carried out to provide a quantitative evaluation of the emission characteristics in terms of the role of high and super-emitters in total emission reduction, impact of after-treatment on the multi-pollutants reduction strategy and the trend of NO2 emissions with newer emission standards. The study revealed that not all the high-emitters are from those vehicles of older Euro emission standards. Meanwhile, there is clear evidence that high-emitters for one pollutant may not be a high-emitter for another pollutant. Multi-pollutant control strategy needs to be considered in the enactment of the emission control policy which requires more comprehensive retrofitting technological solutions and matching I/M programme to ensure the proper maintenance of fleets. The plume chasing approach used in this study also

  13. Small size probe for inner profile measurement of pipes using optical fiber ring beam device

    NASA Astrophysics Data System (ADS)

    Wakayama, Toshitaka; Machi, Kizuku; Yoshizawa, Toru

    2012-11-01

    The requirements of inner profile measurement of pipes and holes become recently larger and larger, and applications of inner profile measurement have rapidly expanded to medical field as well as industrial fields such as mechanical, automobile and heavy industries. We have proposed measurement method by incorporating a ring beam device that produces a disk beam and have developed various probes for different inner profile measurement. To meet request for applying to smaller diameter pipes, we tried to improve the ring beam light source using a conical mirror, optical fiber collimator and a laser diode. At this moment a probe with the size of 5 mm in diameter has been realized.

  14. Deconvolution-based correction of alkali beam emission spectroscopy density profile measurements

    SciTech Connect

    Pusztai, I.; Pokol, G.; Refy, D.; Por, G.; Dunai, D.; Anda, G.; Zoletnik, S.; Schweinzer, J.

    2009-08-15

    A deconvolution-based correction method of the beam emission spectroscopy (BES) density profile measurement is demonstrated by its application to simulated measurements of the COMPASS and TEXTOR tokamaks. If the line of sight is far from tangential to the flux surfaces, and the beam width is comparable to the scale length on which the light profile varies, the observation may cause an undesired smoothing of the light profile, resulting in a non-negligible underestimation of the calculated density profile. This effect can be reduced significantly by the emission reconstruction method, which gives an estimate of the emissivity along the beam axis from the measured light profile, taking the finite beam width and the properties of the measurement into account in terms of the transfer function of the observation. Characteristics and magnitude of the mentioned systematic error and its reduction by the introduced method are studied by means of the comprehensive alkali BES simulation code RENATE.

  15. Evaluation of Acoustic Doppler Current Profiler measurements of river discharge

    USGS Publications Warehouse

    Morlock, S.E.

    1996-01-01

    The standard deviations of the ADCP measurements ranged from approximately 1 to 6 percent and were generally higher than the measurement errors predicted by error-propagation analysis of ADCP instrument performance. These error-prediction methods assume that the largest component of ADCP discharge measurement error is instrument related. The larger standard deviations indicate that substantial portions of measurement error may be attributable to sources unrelated to ADCP electronics or signal processing and are functions of the field environment.

  16. Measuring solar- and greenhouse radiation profiles in the atmosphere using upper-air radiosondes

    NASA Astrophysics Data System (ADS)

    Philipona, R.; Kräuchi, A.

    2012-04-01

    Solar shortwave and thermal longwave irradiance is usually measured at the Earth's surface with ground radiation stations and at the top of the atmosphere with satellites. Here we show for the first time radiative flux profiles and the radiation budget in the atmosphere measured with radiosondes ascending from the Earth's surface to 35 km into the stratosphere. During two-hour flights solar shortwave and thermal longwave irradiance, downward and upward, is measured with four individual sensors at one-second resolution, along with standard PTU radiosonde profiles. Nighttime longwave radiation measurements are contrasted to daytime measurements and 24 hours means of radiation budget- and total net radiation profiles are shown. Of particular interest for greenhouse effect investigations are in situ measured longwave greenhouse radiation profiles and their vertical changes in relation to temperature, clouds, water vapour and other greenhouse gases.

  17. Distributed road assessment system

    DOEpatents

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

    A system that detects damage on or below the surface of a paved structure or pavement is provided. A distributed road assessment system includes road assessment pods and a road assessment server. Each road assessment pod includes a ground-penetrating radar antenna array and a detection system that detects road damage from the return signals as the vehicle on which the pod is mounted travels down a road. Each road assessment pod transmits to the road assessment server occurrence information describing each occurrence of road damage that is newly detected on a current scan of a road. The road assessment server maintains a road damage database of occurrence information describing the previously detected occurrences of road damage. After the road assessment server receives occurrence information for newly detected occurrences of road damage for a portion of a road, the road assessment server determines which newly detected occurrences correspond to which previously detected occurrences of road damage.

  18. Standardization of methods for extracting statistics from surface profile measurements

    NASA Astrophysics Data System (ADS)

    Takacs, Peter Z.

    2014-08-01

    Surface profilers and optical interferometers produce 2D maps of surface and wavefront topography. Traditional standards and methods for characterizing the properties of these surfaces use coordinate space representations of the surface topography. The computing power available today in modest personal computers makes it easy to transform into frequency space and apply well-known signal processing techniques to analyze the data. The Power Spectral Density (PSD) function of the surface height distribution is a powerful tool to assess the quality and characteristics of the surface in question. In order to extract useful information about the spectral distribution of surface roughness or mid-spatial frequency error over a particular spatial frequency band, it is necessary to pre-process the data by first detrending the surface figure terms and then applying a window function before computing the PSD. This process eliminates discontinuities at the borders of the profile that would otherwise produce large amounts of spurious power that would mask the true nature of the surface texture. This procedure is now part of a new draft standard that is being adopted by the US OEOSC for analysis of the statistics of optical surface, OP1.005.1 Illustrations of the usefulness of these procedures will be presented.

  19. a Compact Dial LIDAR for Ground-Based Ozone Atmospheric Profiling Measurements

    NASA Astrophysics Data System (ADS)

    De Young, R.; Carrion, W.; Pliutau, D.; Ganoe, R. E.

    2013-12-01

    ozone profiles from 100 to 200-m above ground. To obtain an ozone atmospheric measurement, the transmitter sends a laser pulse into the atmosphere at alternating on-line and off-line wavelengths (500Hz each line). The 527-nm green laser output is always transmitted giving a return from atmospheric aerosols. Examples of ozone profiles in the Hampton Roads region of Virginia will be presented. The system has been configured to enable mobile operation from a trailer which is environmentally controlled, and is towed with a truck to sites that are equipped with power. The objective is to make the system mobile such that it can be setup at remote sites to support major air quality field campaigns.

  20. Profiles of Material Properties in Induction-Hardened Steel Determined through Inversion of Resonant Acoustic Measurements

    SciTech Connect

    Johnson, W.L.; Kim, S.A.; Norton, S.J.

    2005-04-09

    Electromagnetic-acoustic measurements of resonant frequencies of induction-hardened steel shafts were used in an inverse calculation to determine parameters of the radial variations in the shear constant and density, including the effects of material variations and residual stress. Parameters determined for the profile of the shear constant were consistent with independent measurements on cut specimens and estimates of the acoustoelastic contribution. The profiles determined for material variations were close to those of the measured hardness.

  1. In Situ Aerosol Profile Measurements and Comparisons with SAGE 3 Aerosol Extinction and Surface Area Profiles at 68 deg North

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Under funding from this proposal three in situ profile measurements of stratospheric sulfate aerosol and ozone were completed from balloon-borne platforms. The measured quantities are aerosol size resolved number concentration and ozone. The one derived product is aerosol size distribution, from which aerosol moments, such as surface area, volume, and extinction can be calculated for comparison with SAGE III measurements and SAGE III derived products, such as surface area. The analysis of these profiles and comparison with SAGE III extinction measurements and SAGE III derived surface areas are provided in Yongxiao (2005), which comprised the research thesis component of Mr. Jian Yongxiao's M.S. degree in Atmospheric Science at the University of Wyoming. In addition analysis continues on using principal component analysis (PCA) to derive aerosol surface area from the 9 wavelength extinction measurements available from SAGE III. Ths paper will present PCA components to calculate surface area from SAGE III measurements and compare these derived surface areas with those available directly from in situ size distribution measurements, as well as surface areas which would be derived from PCA and Thomason's algorithm applied to the four wavelength SAGE II extinction measurements.

  2. CO{sub 2}-mitigation measures through reduction of fossil fuel burning in power utilities. Which road to go?

    SciTech Connect

    Kaupp, A.

    1996-12-31

    Five conditions, at minimum, should be examined in the comparative analysis of CO{sub 2}-mitigation options for the power sector. Under the continuing constraint of scarce financial resources for any private or public investment in the power sector, the following combination of requirements characterise a successful CO{sub 2}-mitigation project: (1) Financial attractiveness for private or public investors. (2) Low, or even negative, long range marginal costs per ton of `CO{sub 2} saved`. (3) High impact on CO{sub 2}-mitigation, which indicates a large market potential for the measure. (4) The number of individual investments required to achieve the impact is relatively small. In other words, logistical difficulties in project implementation are minimised. (5) The projects are `socially fair` and have minimal negative impact on any segment of the society. This paper deals with options to reduce carbonaceous fuel burning in the power sector. Part I explains how projects should be selected and classified. Part II describes the technical options. Since reduction of carbonaceous fuel burning may be achieved through Demand Side Management (DSM) and Supply Side Management (SSM) both are treated. Within the context of this paper SSM does not mean to expand power supply as demand grows. It means to economically generate and distribute power as efficiently as possible. In too many instances DSM has degenerated into efficient lighting programs and utility managed incentives and rebate programs. To what extent this is a desirable situation for utilities in Developing Countries that face totally different problems as their counterparts in highly industrialised countries remains to be seen. Which road to go is the topic of this paper.

  3. A lidar system for measuring atmospheric pressure and temperature profiles

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Dombrowski, Mark; Korb, C. Laurence; Milrod, Jeffry; Walden, Harvey

    1987-01-01

    The design and operation of a differential absorption lidar system capable of remotely measuring the vertical structure of tropospheric pressure and temperature are described. The measurements are based on the absorption by atmospheric oxygen of the spectrally narrowband output of two pulsed alexandrite lasers. Detailed laser output spectral characteristics, which are critical to successful lidar measurements, are presented. Spectral linewidths of 0.026 and 0.018 per cm for the lasers were measured with over 99.99 percent of the energy contained in three longitudinal modes.

  4. Profile Measurements of BVOC Emissions from a Norway spruce

    NASA Astrophysics Data System (ADS)

    Wang, M.

    2015-12-01

    Biogenic volatile organic compounds (BVOCs) are known as a source of secondary organic aerosols (SOA) due to their high reactivity with O3 and OH in the atmosphere [1, 2]. Norway spruce is one of the dominant boreal forest species in northern Europe, which has been considered to be high monoterpene (MT) emitters [3, 4]. BVOC emissions and compound composition vary considerably under different temperature and light conditions through growing season [5, 6]. Information of vertical profile emission patterns is indispensible for understanding chemical processes and oxidation sinks within canopy and for modelling evaluation. We characterize the in-canopy BVOC emissions from a 120 years old Norway spruce in Central Sweden (Norunda, 60°05'N, 17°29'E). Air samples were taken during the growing season (June to September 2013 & 2014) from transparent dynamic branch chambers set up in a vertical profile with 4 levels (20 m, 15 m, 11 m and 3 m agl.) on the spruce. Samples were collected every hour from the chamber with Tenax-TA adsorbent tubes and a pocket pump, and analyzed later by gas chromatography and a mass selective detector (GC-MS) to quantify each trapped terpenoid compound. The emission spectrum of Norway spruce at 20 m canopy height was found to be more complex than the emissions spectra at lower canopy levels, and included isoprene, MT and SQT from June to September, while MT was the dominating terpenoid species. The emission spectra of July and August (isoprene, 14 MT and 3 SQT) were much more complex compared to June and September at the 20 m canopy level, and mainly caused by an increase of MT species during peak season. Similarly, isoprene showed a distinctive seasonal pattern, and was detected at all the heights during noon time except the bottom 3 m level during peak summer, but only at the highest layer (20 m) during noon in early or late summer. O3 vertical profile data will be available for further chemical process analysis within canopy. References[1]M

  5. Comparison of raindrop size distributions measured by radar wind profiler and by airplane

    SciTech Connect

    Rogers, R.R.; Ethier, S.A. ); Baumgardner, D. ); Carter, D.A.; Ecklund, W.L. )

    1993-04-01

    Wind profilers are radars that operate in the VHF and UHF bands and are designed for detecting the weak echoes reflected by the optically clear atmosphere. An unexpected application of wind profilers has been the revival of an old method of estimating drop size distributions in rain from the Doppler spectrum of the received signal. Originally attempted with radars operating at microwave frequencies, the method showed early promise but was seriously limited in application because of the crucial sensitivity of the estimated drop sizes to the vertical air velocity, a quantity generally unknown and, at that time, unmeasurable. Profilers have solved this problem through their ability to measure, under appropriate conditions, both air motions and drop motions. This paper compares the drop sizes measured by a UHF profiler at two altitudes in a shower with those measured simultaneously by an instrumented airplane. The agreement is satisfactory, lending support to this new application of wind profilers. 20 refs., 5 figs.

  6. Apparent abundance and vertical profiles of ozone from OMEGA measurements

    NASA Astrophysics Data System (ADS)

    Altieri, F.; Zasova, L.; Grassi, D.; Bellucci, G.; Bibring, J.-P.; Formisano, V.; Ignatiev, N.; Drossart, P.; Encrenaz, T.; Fouchet, T.; OMEGA Team

    In this work we study the vertical and seasonal distribution of O2 by means the 1.27 micron day glow emission in the spectra acquired by OMEGA, the imaging spectrometer on board the ESA mission Mars Express. Limb OMEGA observations have been used to retrieve the vertical distribution of O3 up to 20 km, applying an "onion peeling" procedure. The quenching effect due to the collisions with the CO2 have been taken into account using simultaneously vertical CO2 profiles obtained by the PFS LWC data. OMEGA nadir observations have been used to map the latitude, local time and seasonal distribution of the apparent ozone abundance in the Martian atmosphere and results are discussed. We acknowledge the ESA Headquarters and IFSI-INAF for support to Russian CoIs and the Russian Foundation of Basic Research for grant RFFI 04-02-16856a.

  7. PNNL/Euratom glass fiber-optic, spent-fuel profile measurement system

    SciTech Connect

    Bowyer, S.M.; Smart, J.E.; Hansen, R.R.

    1999-07-01

    Discussions between Euratom and Pacific Northwest National Laboratory (PNNL) revealed a need for a neutron detection system that could measure the neutron profile down the entire length of a CASTOR in one measurement. The CASTORS (dry storage casks for spent fuel and vitrified wastes) are {approximately}6 m high and 2 x 2 m square in cross section. Neutron profiles of the CASTORS are desirable for both content identification and verification. Profile measurements have traditionally been done with {sup 3}He-based detectors {approximately}1 m high that scan the length of a CASTOR as they are lifted by a crane. Geometric reproducibility errors plague this type of measurement; hence, the ability to simultaneously measure the neutron profile over the entire length of the CASTOR became highly desirable. Use of the PNNL-developed neutron-sensitive glass fibers in the construction of a 6-m-high detector was proposed, and design and construction of the detector began.

  8. Temporal variability of the trade wind inversion: Measured with a boundary layer vertical profiler. Master's thesis

    SciTech Connect

    Grindinger, C.M.

    1992-05-01

    This study uses Hawaiian Rainband Project (HaRP) data, from the summer of 1991, to show a boundary layer wind profiler can be used to measure the trade wind inversion. An algorithm has been developed for the profiler that objectively measures the depth of the moist oceanic boundary layer. The Hilo inversion, measured by radiosonde, is highly correlated with the moist oceanic boundary layer measured by the profiler at Paradise Park. The inversion height on windward Hawaii is typically 2253 + or - 514 m. The inversion height varies not only on a daily basis, but on less than an hourly basis. It has a diurnal, as well as a three to four day cycle. There appears to be no consistent relationship between inversion height and precipitation. Currently, this profiler is capable of making high frequency (12 minute) measurements of the inversion base variation, as well as other features.

  9. Tethered acoustic doppler current profiler platforms for measuring streamflow

    USGS Publications Warehouse

    Rehmel, Michael S.; Stewart, James A.; Morlock, Scott E.

    2003-01-01

    A tethered-platform design with a trimaran hull and 900-megahertz radio modems is now commercially available. Continued field use has resulted in U.S. Geological Survey procedures for making tethered-platform discharge measurements, including methods for tethered-boat deployment, moving-bed tests, and measurement of edge distances.

  10. An array for measuring detailed soil temperature profiles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil temperature dynamics can provide insights into soil variables which are much more difficult or impossible to measure. We designed an array to measure temperature at precise depth increments. Data was collected to determine if the construction materials influence surface and near-surface tempera...

  11. Beam profile measurement with flying wires at the Fermilab Recycler Ring

    SciTech Connect

    Carcagno, R.; Pishchalnikov, Yu.; Krider, J.; Hu, M.; Lorman, E.; Marchionni, A.; Pordes, S.; Wilson, P.; Zagel, J.; /Fermilab

    2005-05-01

    Flying wires were installed at the Fermilab Recycler Ring for transverse beam profile measurement for both proton and antiproton beams. The following note describes the system configuration, calibration and resolution of the flying wire system, interactions between the wires and the beam, as well as analysis of the transverse beam profile in the presence of a stochastic cooling system.

  12. Intercomparison of aerosol extinction profiles retrieved from MAX-DOAS measurements

    NASA Astrophysics Data System (ADS)

    Frieß, U.; Klein Baltink, H.; Beirle, S.; Clémer, K.; Hendrick, F.; Henzing, B.; Irie, H.; de Leeuw, G.; Li, A.; Moerman, M. M.; van Roozendael, M.; Shaiganfar, R.; Wagner, T.; Wang, Y.; Xie, P.; Yilmaz, S.; Zieger, P.

    2016-07-01

    A first direct intercomparison of aerosol vertical profiles from Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations, performed during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI) in summer 2009, is presented. Five out of 14 participants of the CINDI campaign reported aerosol extinction profiles and aerosol optical thickness (AOT) as deduced from observations of differential slant column densities of the oxygen collision complex (O4) at different elevation angles. Aerosol extinction vertical profiles and AOT are compared to backscatter profiles from a ceilometer instrument and to sun photometer measurements, respectively. Furthermore, the near-surface aerosol extinction coefficient is compared to in situ measurements of a humidity-controlled nephelometer and dry aerosol absorption measurements. The participants of this intercomparison exercise use different approaches for the retrieval of aerosol information, including the retrieval of the full vertical profile using optimal estimation and a parametrised approach with a prescribed profile shape. Despite these large conceptual differences, and also differences in the wavelength of the observed O4 absorption band, good agreement in terms of the vertical structure of aerosols within the boundary layer is achieved between the aerosol extinction profiles retrieved by the different groups and the backscatter profiles observed by the ceilometer instrument. AOTs from MAX-DOAS and sun photometer show a good correlation (R>0.8), but all participants systematically underestimate the AOT. Substantial differences between the near-surface aerosol extinction from MAX-DOAS and from the humidified nephelometer remain largely unresolved.

  13. MEASURING VERTICAL PROFILES OF HYDRAULIC CONDUCTIVITY WITH IN SITU DIRECT-PUSH METHODS

    EPA Science Inventory

    U.S. EPA (Environmental Protection Agency) staff developed a field procedure to measure hydraulic conductivity using a direct-push system to obtain vertical profiles of hydraulic conductivity. Vertical profiles were obtained using an in situ field device-composed of a
    Geopr...

  14. Black carbon, particle number concentration and nitrogen oxide emission factors of random in-use vehicles measured with the on-road chasing method

    NASA Astrophysics Data System (ADS)

    Ježek, I.; Katrašnik, T.; Westerdahl, D.; Močnik, G.

    2015-10-01

    The chasing method was used in an on-road measurement campaign, and emission factors (EF) of black carbon (BC), particle number (PN) and nitrogen oxides (NOx) were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote-sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years decreased by 60 and 47 % from those in use for 5-10 years, respectively; the median NOx and PN EFs of goods vehicles that were in use for less than 5 years decreased from those in use for 5-10 years by 52 and 67 %, respectively. Surprisingly, we found an increase of BC EFs in the newer goods vehicle fleet compared to the 5-10-year old one. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally, a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25 % of emitting diesel cars contributed 63, 47 and 61 % of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements and sophisticated post processing, individual vehicle EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and

  15. Application of positive matrix factorization to on-road measurements for source apportionment of diesel- and gasoline-powered vehicle emissions in Mexico City

    NASA Astrophysics Data System (ADS)

    Thornhill, D. A.; Williams, A. E.; Onasch, T. B.; Wood, E.; Herndon, S. C.; Kolb, C. E.; Knighton, W. B.; Zavala, M.; Molina, L. T.; Marr, L. C.

    2010-04-01

    The goal of this research is to quantify diesel- and gasoline-powered motor vehicle emissions within the Mexico City Metropolitan Area (MCMA) using on-road measurements captured by a mobile laboratory combined with positive matrix factorization (PMF) receptor modeling. During the MCMA-2006 ground-based component of the MILAGRO field campaign, the Aerodyne Mobile Laboratory (AML) measured many gaseous and particulate pollutants, including carbon dioxide, carbon monoxide (CO), nitrogen oxides (NOx), benzene, toluene, alkylated aromatics, formaldehyde, acetaldehyde, acetone, ammonia, particle number, fine particulate mass (PM2.5), and black carbon (BC). These serve as inputs to the receptor model, which is able to resolve three factors corresponding to gasoline engine exhaust, diesel engine exhaust, and the urban background. Using the source profiles, we calculate fuel-based emission factors for each type of exhaust. The MCMA's gasoline-powered vehicles are considerably dirtier, on average, than those in the US with respect to CO and aldehydes. Its diesel-powered vehicles have similar emission factors of NOx and higher emission factors of aldehydes, particle number, and BC. In the fleet sampled during AML driving, gasoline-powered vehicles are found to be responsible for 97% of total vehicular emissions of CO, 22% of NOx, 95-97% of each aromatic species, 72-85% of each carbonyl species, 74% of ammonia, negligible amounts of particle number, 26% of PM2.5, and 2% of BC; diesel-powered vehicles account for the balance. Because the mobile lab spent 17% of its time waiting at stoplights, the results may overemphasize idling conditions, possibly resulting in an underestimate of NOx and overestimate of CO emissions. On the other hand, estimates of the inventory that do not correctly account for emissions during idling are likely to produce bias in the opposite direction.The resulting fuel-based estimates of emissions are lower than in the official inventory for CO and NOx

  16. Application of positive matrix factorization to on-road measurements for source apportionment of diesel- and gasoline-powered vehicle emissions in Mexico City

    NASA Astrophysics Data System (ADS)

    Thornhill, D. A.; Williams, A. E.; Onasch, T. B.; Wood, E.; Herndon, S. C.; Kolb, C. E.; Knighton, W. B.; Zavala, M.; Molina, L. T.; Marr, L. C.

    2009-12-01

    The goal of this research is to quantify diesel- and gasoline-powered motor vehicle emissions within the Mexico City Metropolitan Area (MCMA) using on-road measurements captured by a mobile laboratory combined with positive matrix factorization (PMF) receptor modeling. During the MCMA-2006 ground-based component of the MILAGRO field campaign, the Aerodyne Mobile Laboratory (AML) measured many gaseous and particulate pollutants, including carbon dioxide, carbon monoxide (CO), nitrogen oxides (NOx), benzene, toluene, alkylated aromatics, formaldehyde, acetaldehyde, acetone, ammonia, particle number, fine particulate mass (PM2.5), and black carbon (BC). These serve as inputs to the receptor model, which is able to resolve three factors corresponding to gasoline engine exhaust, diesel engine exhaust, and the urban background. Using the source profiles, we calculate fuel-based emission factors for each type of exhaust. The MCMA's gasoline-powered vehicles are considerably dirtier, on average, than those in the US with respect to CO and aldehydes. Its diesel-powered vehicles have similar emission factors of NOx and higher emission factors of aldehydes, particle number, and BC. In the fleet sampled during AML driving, gasoline-powered vehicles are responsible for 97% of mobile source emissions of CO, 22% of NOx, 95-97% of aromatics, 72-85% of carbonyls, 74% of ammonia, negligible amounts of particle number, 26% of PM2.5, and 2% of BC; diesel-powered vehicles account for the balance. Because the mobile lab spent 17% of its time waiting at stoplights, the results may overemphasize idling conditions, possibly resulting in an underestimate of NOx and overestimate of CO emissions. On the other hand, estimates of the inventory that do not correctly account for emissions during idling are likely to produce bias in the opposite direction. Nevertheless, the fuel-based inventory suggests that mobile source emissions of CO and NOx are overstated in the official inventory while

  17. Measurement of sound velocity profiles in fluids for process monitoring

    NASA Astrophysics Data System (ADS)

    Wolf, M.; Kühnicke, E.; Lenz, M.; Bock, M.

    2012-12-01

    In ultrasonic measurements, the time of flight to the object interface is often the only information that is analysed. Conventionally it is only possible to determine distances or sound velocities if the other value is known. The current paper deals with a novel method to measure the sound propagation path length and the sound velocity in media with moving scattering particles simultaneously. Since the focal position also depends on sound velocity, it can be used as a second parameter. Via calibration curves it is possible to determine the focal position and sound velocity from the measured time of flight to the focus, which is correlated to the maximum of averaged echo signal amplitude. To move focal position along the acoustic axis, an annular array is used. This allows measuring sound velocity locally resolved without any previous knowledge of the acoustic media and without a reference reflector. In previous publications the functional efficiency of this method was shown for media with constant velocities. In this work the accuracy of these measurements is improved. Furthermore first measurements and simulations are introduced for non-homogeneous media. Therefore an experimental set-up was created to generate a linear temperature gradient, which also causes a gradient of sound velocity.

  18. Interpretation of combined wind profiler and aircraft-measured tropospheric winds and clear air turbulence

    NASA Technical Reports Server (NTRS)

    Thomson, D. W.; Syrett, William J.; Fairall, C. W.

    1991-01-01

    In the first experiment, it was found that wind profilers are far better suited for the detailed examination of jet stream structure than are weather balloons. The combination of good vertical resolution with not previously obtained temporal resolution reveals structural details not seen before. Development of probability-derived shear values appears possible. A good correlation between pilot reports of turbulence and wind shear was found. In the second experiment, hourly measurements of wind speed and direction obtained using two wind profiling Doppler radars during two prolonged jet stream occurrences over western Pennsylvania were analyzed. In particular, the time-variant characteristics of derived shear profiles were examined. Profiler data dropouts were studied in an attempt to determine possible reasons for the apparently reduced performance of profiling radar operating beneath a jet stream. Richardson number and wind shear statistics were examined along with pilot reports of turbulence in the vicinity of the profiler.

  19. Doppler Lidar Measurements of Tropospheric Wind Profiles Using the Aerosol Double Edge Technique

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Mathur, Savyasachee; Korb, C. Laurence; Chen, Huailin

    2000-01-01

    The development of a ground based direct detection Doppler lidar based on the recently described aerosol double edge technique is reported. A pulsed, injection seeded Nd:YAG laser operating at 1064 nm is used to make range resolved measurements of atmospheric winds in the free troposphere. The wind measurements are determined by measuring the Doppler shift of the laser signal backscattered from atmospheric aerosols. The lidar instrument and double edge method are described and initial tropospheric wind profile measurements are presented. Wind profiles are reported for both day and night operation. The measurements extend to altitudes as high as 14 km and are compared to rawinsonde wind profile data from Dulles airport in Virginia. Vertical resolution of the lidar measurements is 330 m and the rms precision of the measurements is a low as 0.6 m/s.

  20. Comparison of Profiling Microwave Radiometer, Aircraft, and Radiosonde Measurements From the Alliance Icing Research Study (AIRS)

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.

    2001-01-01

    Measurements from a profiling microwave radiometer are compared to measurements from a research aircraft and radiosondes. Data compared is temperature, water vapor, and liquid water profiles. Data was gathered at the Alliance Icing Research Study (AIRS) at Mirabel Airport outside Montreal, Canada during December 1999 and January 2000. All radiometer measurements were found to lose accuracy when the radome was wet. When the radome was not wetted, the radiometer was seen to indicate an inverted distribution of liquid water within a cloud. When the radiometer measurements were made at 15 deg. instead of the standard zenith, the measurements were less accurate.

  1. Automated acoustic intensity measurements and the effect of gear tooth profile on noise

    NASA Technical Reports Server (NTRS)

    Atherton, W. J.; Pintz, A.; Lewicki, D. G.

    1987-01-01

    Acoustic intensity measurements were made at NASA Lewis Research Center on a spur gear test apparatus. The measurements were obtained with the Robotic Acoustic Intensity Measurement System developed by Cleveland State University. This system provided dense spatial positioning, and was calibrated against a high quality acoustic intensity system. The measured gear noise compared gearsets having two different tooth profiles. The tests evaluated the sound field of the different gears for two speeds and three loads. The experimental results showed that gear tooth profile had a major effect on measured noise. Load and speed were found to have an effect on noise also.

  2. Development of an inner profile measurement instrument using a ring beam device

    NASA Astrophysics Data System (ADS)

    Yoshizawa, T.; Wakayama, T.

    2010-11-01

    Inner profile measurement is an important matter in such fields as medicine, dentistry and anthropology as well as mechanical engineering and other industrial applications. Here we describe recent development of our measurement principle for inner diameter of pipes and/or holes. The key device in this technique is a ring beam device which consists of a conical mirror and a laser diode. And the fundamental principle is based on optical sectioning without using any contact type stylus. The optically sectioned profile of an inner wall of a pipe-like object is analyzed to give the inner profile in addition to the inner diameter. This optical instrument with a simple and small configuration is now under development for practical uses. In our hitherto trial experimental works, the availability of this instrument has been evaluated in many cases and availability for practical applications is expected, especially, for measurement and inspection of mechanical components and elements besides pipes. This ring beam device consisting of a conical mirror and a LD is assembled to form a disk-like light sheet. We show measurement result of pipes and holes, and, at the same time, report a compact inner profile measuring instrument at this point. Both the ring beam device and a miniaturized CCD camera are fabricated into a glass tube. Availability of this instrument is shown by measuring the inner profiles of various pipes. In response to this trial, there appeared a strong request that not only the internal but external profiles should be measured simultaneously. Therefore we propose potentially possible method for measurement of external profile at the same time with internal profile. If one pair of concave mirrors are used in our arrangement, external profile is captured. In combination with inner profile measurement technique, simultaneous measurement of inner and outer profiles becomes attainable. A measurement result on a bevel gear shows availability of here proposed

  3. Measuring mRNA Translation by Polysome Profiling.

    PubMed

    Kudla, Marek; Karginov, Fedor V

    2016-01-01

    Determination of mRNA translation rates is essential to understanding the regulatory pathways governing eukaryotic gene expression. In this chapter, we present a transcriptome-wide method to assess translation by association of mRNAs with polysomes on sucrose density gradients. After sedimentation, the fractions are spiked with a control RNA mixture and the RNA content is measured by high-throughput sequencing. Normalization to the spike-ins provides a global quantitative view on the translational status of cellular mRNAs, with the ability to measure changes and identify active and silent subpopulations of each.

  4. Continuous Profiles of Cloud Microphysical Properties for the Fixed Atmospheric Radiation Measurement Sites

    SciTech Connect

    Jensen, M; Jensen, K

    2006-06-01

    The Atmospheric Radiation Measurement (ARM) Program defined a specific metric for the third quarter of Fiscal Year 2006 to produce and refine a one-year continuous time series of cloud microphysical properties based on cloud radar measurements for each of the fixed ARM sites. To accomplish this metric, we used a combination of recently developed algorithms that interpret radar reflectivity profiles, lidar backscatter profiles, and microwave brightness temperatures into the context of the underlying cloud microphysical structure.

  5. AZ State Profile. Arizona: Arizona's Instrument to Measure Standards (AIMS)

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper provides information about the Arizona's Instrument to Measure Standards (AIMS). The purpose of the test is to determine prospective high school graduates' mastery of the state curriculum and to meet a state mandate. [For the main report, "State High School Tests: Exit Exams and Other Assessments", see ED514155.

  6. Metastable atom probe for measuring electron beam density profiles

    NASA Technical Reports Server (NTRS)

    Lockhart, J. M.; Zorn, J. C.

    1972-01-01

    Metastable atom probe was developed for measuring current density in electron beam as function of two arbitrary coordinates, with spatial resolution better than 0.5 mm. Probe shows effects of space charge, magnetic fields, and other factors which influence electron current density, but operates with such low beam densities that introduced perturbation is very small.

  7. Design and development of the LEDA slow wire scanner profile measurement

    SciTech Connect

    O`Hara, J.F.; Power, J.F.; Ledford, J.; Gilpatrick, J.D.; Stettler, M.; Sage, J.

    1998-12-31

    The Low Energy Demonstration Accelerator (LEDA) is being developed at Los Alamos National Laboratory as part of the Accelerator Production of Tritium (APT) project. One of the diagnostics being developed to commission LEDSA is a slow wire scanner beam profile measurement. Initial profile measurements will be made at 6.7 MeV beam energy and 100 mA beam current. The wire scanner is an interceptive device that will move two silicon carbide coated graphite mono-filament fibers (wires) through the beam, in order to obtain the profile. Some of the design considerations discussed are: Mechanical design, wire temperature analysis, secondary electron detection, signal processing, and system control.

  8. Celtic Roads

    ERIC Educational Resources Information Center

    Kinney, Jan

    2009-01-01

    Building upon lessons learned is relevant to art and life. As an art teacher dealing with teens, the author tries to give her students an understanding of art as a window to the "big picture" as well as a practical, relevant skill. She developed this lesson plan, "Celtic Roads," with that objective in mind. The success rate is high, the product is…

  9. Estimation of volcanic ash emission profiles using ceilometer measurements and transport models

    NASA Astrophysics Data System (ADS)

    Chan, Ka Lok; Geiß, Alexander; Gasteiger, Josef; Wagner, Frank; Wiegner, Matthias

    2016-04-01

    In recent years, the number of active remote sensing systems grows rapidly, since several national weather services initiated ceilometer networks. These networks are excellent tools to monitor the dispersion of volcanic ash clouds and to validate chemical transport models. Moreover, it is expected that the can be used to refine model calculations to better predict situations that might be dangerous for aviation. As a ceilometer can be considered as a simple single-wavelength backscatter lidar, quantitative aerosol profile information, i.e., the aerosol backscatter coefficient (βp) profile, can be derived provided that the ceilometer is calibrated. Volcanic ash concentration profile can then be estimated by using prior optical properties of volcanic ash. These profiles are then used for the inverse calculation of the emission profile of the volcanic eruption, thus, improving one of the most critical parameters of the numerical simulation. In this study, the Lagrangian particle dispersion model FLEXPART (FLEXible PARTicle dispersion model) is used to simulate the dispersion of volcanic ash. We simulate the distribution of ash for a given time/height grid, in order to compute the sensitivity functions for each measurements. As an example we use ceilometer measurements of the German weather service to reconstruct the temporal and spatial emission profile of Eyjafjallajökull eruption in April 2010. We have also examined the sensitivity of the retrieved emission profiles to different measurement parameters, e.g., geolocation of the measurement sites, total number of measurement sites, temporal and vertical resolution of the measurements, etc. The first results show that ceilometer measurements in principle are feasible for the inversion of volcanic ash emission profiles.

  10. Measuring depth profiles of residual stress with Raman spectroscopy

    SciTech Connect

    Enloe, W.S.; Sparks, R.G.; Paesler, M.A.

    1988-12-01

    Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

  11. Characterizing Decades of Cloud Measurements from Combined ARM Profiling Radar and Lidar Measurements

    NASA Astrophysics Data System (ADS)

    Johnson, K. L.; Jensen, M. P.; Baxter, S.; Toto, T.; Wang, M.; Kollias, P.; Clothiaux, E. E.

    2014-12-01

    The U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program has continuously operated profiling cloud radars and micropulse lidars at five fixed sites, for periods ranging from eight to nineteen years. The sites include the U.S. southern Great Plains, the Alaska North Slope and three Tropical Western Pacific locations. The radar and lidar observations, along with ceilometer and precipitation measurements, have been synthesized using ARM's Active Remote Sensing of Clouds (ARSCL) value-added product, which provides cloud boundaries and best-estimate radar reflectivities, mean Doppler velocities and spectral widths. The product's time resolution ranges from 10 seconds down to 4 seconds, with height resolution of 45 meters or better. Through its use in retrievals of cloud microphysics and dynamics, this high-resolution, long-term data set has the potential to make major contributions toward improved cloud representations in climate models and the understanding of cloud processes. However, it is essential that data set quality and accuracy be assessed and made available to data users in order to maximize utility and reliability. In this study, we apply a variety of approaches to characterize observation quality throughout the ARSCL data record at each site. We describe instrument availability and radar operating status and possible issues. We track radar sensitivity as a function of time through cirrus detection statistics as well as changes in radar signal saturation level over time. We also examine noise and insect clutter reflectivity levels as possible surrogates for radar calibration changes. Through these and other techniques, we assess the most and least reliable time periods for each instrumented site and provide valuable guidance to potential data users, for both case-study research and long-term climatological applications.

  12. Rapid road repair vehicle

    SciTech Connect

    Mara, L.M.

    1999-09-07

    Disclosed are improvements to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  13. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1999-01-01

    Disclosed are improvments to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  14. TH-C-18A-04: Validation of Dosimetric Measurement of CT Radiation Profile Width

    SciTech Connect

    Gauntt, D; Al-Senan, R

    2014-06-15

    Purpose: The ACR now requires that the CT radiation profile width be measured at all clinically used collimations. We developed a method for measuring the profile width using dosimetry alone to allow a faster and simpler measurement of beam widths. Methods: A pencil ionization chamber is used to take two dose-length product measurements in air for a wide collimation. One of these is taken with a 1cm tungsten mask on the pencil chamber. The difference between these measurements is the calibration factor, or the DLP in air per unit length. By dividing the doselength product for any given collimation by this factor, we can rapidly determine the beam profile width.We measured the beam width for all available detector configurations and focal spot sizes on three different CT scanners from two different manufacturers. The measurements were done using film, CR cassette, and the present dosimetric method. Results: The beam widths measured dosimetrically are approximately 2% wider than those measured using film or computed radiography; this difference is believed due to off-focus or scattered radiation. After correcting for this, the dosimetric beam widths match the film and CR widths with an RMS difference of approximately 0.2mm. The measured beam widths are largely insensitive to errors in positioning of the mask, or to tilt errors in the pencil chamber. Conclusion: Using the present method, radiation profile widths can be measured quickly, with an accuracy better than 1mm.

  15. Photogrammetric Techniques for Road Surface Analysis

    NASA Astrophysics Data System (ADS)

    Knyaz, V. A.; Chibunichev, A. G.

    2016-06-01

    The quality and condition of a road surface is of great importance for convenience and safety of driving. So the investigations of the behaviour of road materials in laboratory conditions and monitoring of existing roads are widely fulfilled for controlling a geometric parameters and detecting defects in the road surface. Photogrammetry as accurate non-contact measuring method provides powerful means for solving different tasks in road surface reconstruction and analysis. The range of dimensions concerned in road surface analysis can have great variation from tenths of millimetre to hundreds meters and more. So a set of techniques is needed to meet all requirements of road parameters estimation. Two photogrammetric techniques for road surface analysis are presented: for accurate measuring of road pavement and for road surface reconstruction based on imagery obtained from unmanned aerial vehicle. The first technique uses photogrammetric system based on structured light for fast and accurate surface 3D reconstruction and it allows analysing the characteristics of road texture and monitoring the pavement behaviour. The second technique provides dense 3D model road suitable for road macro parameters estimation.

  16. SU-E-P-24: Simplified EDW Profile Measurements Using Two Commonly Available Detector Arrays

    SciTech Connect

    Reynolds, T; Arentsen, L; Watanabe, Y; Alaei, P

    2015-06-15

    Purpose: Enhanced dynamic wedge (EDW) profiles are needed as part of the commissioning of a treatment planning system. This work compares the acquisition of EDW profiles using a linear diode array (LDA) with two commonly used detector arrays available in the clinics, with the goal of identifying the simplest approach for these measurements. Methods: The measurements of EDW profiles were performed on a Varian TrueBeam linear accelerator for 6, 10, and 18 MV photon beams for all seven wedge angles at four depths. The measurements were done using the LDA 99 in Blue Phantom2 (IBA Dosimetry), and IC Profiler and MapCHECK2 (Sun Nuclear) in solid water phantoms. The water phantom was set up at 100 cm SSD, whereas the two other devices were set up at 75 cm due to the size limitations of the devices. The largest possible field size was used. The average and maximum percentage differences were examined within the central 90% of the field and in the penumbra. Results: Dose profiles measured with IC Profiler were in a good agreement with LDA 99 data. The average percentage difference within the field did not exceed 0.5% for all energies. MapCHECK2 measurements matched well with LDA 99 for 10 and 18 MV (within 0.3%) with discrepancies of up to 1.4% observed for the 6 MV beam. The maximum percentage differences for both devices in the penumbra exhibited larger variations than LDA 99 results due to differences in detector spacing and high dose gradient, as expected. Conclusion: Common linac QA devices such as IC Profiler or MapCHECK2 provide EDW beam profile data of reasonable accuracy as compared to measurements performed using a linear diode array in a water phantom, saving the expense and time involved in acquiring and setting up a LDA.

  17. Optimal sets of measurement data for profile reconstruction in scatterometry

    NASA Astrophysics Data System (ADS)

    Gross, H.; Rathsfeld, A.; Scholze, F.; Bär, M.; Dersch, U.

    2007-06-01

    We discuss numerical algorithms for the determination of periodic surface structures from light diffraction patterns. With decreasing feature sizes of lithography masks, increasing demands on metrology techniques arise. Scatterometry as a non-imaging indirect optical method is applied to simple periodic line structures in order to determine parameters like side-wall angles, heights, top and bottom widths and to evaluate the quality of the manufacturing process. The numerical simulation of diffraction is based on the finite element solution of the Helmholtz equation. The inverse problem seeks to reconstruct the grating geometry from measured diffraction patterns. Restricting the class of gratings and the set of measurements, this inverse problem can be reformulated as a non-linear operator equation in Euclidean spaces. The operator maps the grating parameters to special efficiencies of diffracted plane wave modes. We employ a Gauss-Newton type iterative method to solve this operator equation. The reconstruction properties and the convergence of the algorithm, however, is controlled by the local conditioning of the non-linear mapping. To improve reconstruction and convergence, we determine optimal sets of efficiencies optimizing the condition numbers of the corresponding Jacobians. Numerical examples are presented for "chrome on glass" masks under the wavelength 632.8 nm and for EUV masks.

  18. Study on measurement of refractive index profile of GI-POF by light scattering

    NASA Astrophysics Data System (ADS)

    Huifen, Jiang; Xiang'e, Han

    2009-04-01

    This paper is devoted to the study on measurement of refractive index profile of graded-index polymer optical fiber (GI-POF) by light scattering. Using Generalized Airy theory and Debye series of an inhomogeneous cylinder, the scattering intensity distributions are obtained of Airy structure of rainbows for different refractive index profile. The results show that positions of Airy peaks depend closely on refractive index profile of GI-POF. Since each order of rainbow penetrates it to different depths, such methods could be used to provide information of the refractive index profile of GI-POF. For GI-POF with given diameter, positions of Airy peaks of rainbows are simulated as a function of refractive index profile, which can be used to inverse unknown parameters of refractive index profile. The least square method is used in inversion of refractive index profile with the given refractive index of the cladding. The results obtained agree with theoretical values with high precision. The method has the advantages of non-instructive and on-line measurement, and can be used for the measurement of other inhomogeneous droplets.

  19. A novel non-contact profiler design for measuring synchrotron radiation mirrors

    SciTech Connect

    Lin, Yao; Takacs, P.Z.; Furenlid, K.; DeBiasse, R.A. ); Wang, Run-Wen . Shanghai Inst. of Optics and Fine Mechanics)

    1990-08-01

    A novel optical profiler is described in this paper for measurement of surface profiles of synchrotron radiation (SR) mirrors. The measurement is based on a combination of an optical heterodyne technique and a precise phase measurement procedure without a reference surface. A Zeeman two-frequency He-Ne laser is employed as the light source. The common-path optical system, which uses a birefringent lens as the beam splitter, minimizes the effects of air turbulence, sample vibration and temperature variation. A special autofocus system allows the profiler to measure the roughness and shape of a sample surface. The optical system is mounted on a large linear air-bearing slide, and is capable of scanning over distances covering the spatial period range from several microns to nearly one meter with a high measurement accuracy. 9 refs., 5 figs.

  20. Coarse-fine vertical scanning based optical profiler for structured surface measurement with large step height

    NASA Astrophysics Data System (ADS)

    Zheng, Yi; Liu, Xiaojun; Lei, Zili; Li, Qian; Yang, Xiao; Chen, Liangzhou; Lu, Wenlong

    2015-02-01

    White light interference (WLI) optical profiler had been used widely for structured surface measurement. To achieve high measuring accuracy, piezoelectric ceramic (PZT) was usually used as the vertical scanning unit, which was normally less than 100um and only for small range structured surface measurement. With the development of advanced manufacturing technology, precision structured surfaces with large step height were appearing. To satisfy the measurement requirements of this kind of precision structured surfaces, WLI optical profiler with large range had to be developed. In this paper, an optical profiler was proposed, in which a coarse-fine vertical scanning system was adopted to expand its measurement range to 10mm while its resolution still at nanometer level.

  1. Neutral Probe Beam q-profile measurements in PDX and PBX-M

    SciTech Connect

    Kugel, H.W.; Gammel, G.M.; Kaita, R.; Reusch, M.F.; Roberts, D.W.

    1988-06-01

    Using the Fast Ion Diagnostic Experiment (FIDE) technique, a Neutral Probe Beam (NPB) can be aimed to inject tangentially to a magnetic surface. The resultant ion orbit shifts, due to conservation of canonical toroidal angular momentum, can be measured with a multi-sightline charge-exchange analyzer to yield direct measurements of radial magnetic flux profiles, current density profiles, the radial position of the magnetic axis, flux surface inner and outer edges, q-profiles, and central-q time dependencies. An extensive error analysis was performed on previous PDX q-measurements in circular plasmas and the resulting estimated contributions of various systematic effects are discussed. Preliminary results of fast ion orbit shift measurements at early times in indented PBX-M plasmas are given. Methods for increasing the absolute experimental precision of similar measurements in progress on PBX-M are discussed. 4 refs., 3 figs.

  2. Neutral probe beam q-profile measurements in PDX and PBX-M

    NASA Astrophysics Data System (ADS)

    Kugel, H. W.; Gammel, G. M.; Kaita, R.; Reusch, M. F.; Roberts, D. W.

    1988-08-01

    Using the fast ion diagnostic experiment technique, a neutral probe beam (NPB) can be aimed to inject tangent to a magnetic surface. The resultant ion orbit shifts, due to conservation of canonical toroidal angular momentum, can be measured with a multi-sight-line charge exchange analyzer to yield direct measurements of radial magnetic flux profiles, current-density profiles, the radial position of the magnetic axis, flux surface inner and outer edges, q profiles, and central-q time dependencies. An extensive error analysis was performed on previous PDX q measurements in circular plasmas and the resulting estimated contributions of various systematic effects are discussed. Preliminary results of fast ion orbit shift measurements at early times in indented PBX-M plasmas are given. Methods for increasing the absolute experimental precision of similar measurements in progress on PBX-M are discussed.

  3. Measurement of bow tie profiles in CT scanners using a real-time dosimeter

    SciTech Connect

    Whiting, Bruce R.; Evans, Joshua D.; Williamson, Jeffrey F.; Dohatcu, Andreea C.; Politte, David G.

    2014-10-15

    Purpose: Several areas of computed tomography (CT) research require knowledge about the intensity profile of the x-ray fan beam that is introduced by a bow tie filter. This information is considered proprietary by CT manufacturers, so noninvasive measurement methods are required. One method using real-time dosimeters has been proposed in the literature. A commercially available dosimeter was used to apply that method, and analysis techniques were developed to extract fan beam profiles from measurements. Methods: A real-time ion chamber was placed near the periphery of an empty CT gantry and the dose rate versus time waveform was recorded as the x-ray source rotated about the isocenter. In contrast to previously proposed analysis methods that assumed a pointlike detector, the finite-size ion chamber received varying amounts of coverage by the collimated x-ray beam during rotation, precluding a simple relationship between the source intensity as a function of fan beam angle and measured intensity. A two-parameter model for measurement intensity was developed that included both effective collimation width and source-to-detector distance, which then was iteratively solved to minimize the error between duplicate measurements at corresponding fan beam angles, allowing determination of the fan beam profile from measured dose-rate waveforms. Measurements were performed on five different scanner systems while varying parameters such as collimation, kVp, and bow tie filters. On one system, direct measurements of the bow tie profile were collected for comparison with the real-time dosimeter technique. Results: The data analysis method for a finite-size detector was found to produce a fan beam profile estimate with a relative error between duplicate measurement intensities of <5%. It was robust over a wide range of collimation widths (e.g., 1–40 mm), producing fan beam profiles that agreed with a relative error of 1%–5%. Comparison with a direct measurement technique on

  4. Evaluation and modelling of the size fractionated aerosol particle number concentration measurements nearby a major road in Helsinki - Part I: Modelling results within the LIPIKA project

    NASA Astrophysics Data System (ADS)

    Pohjola, M. A.; Pirjola, L.; Karppinen, A.; Härkönen, J.; Korhonen, H.; Hussein, T.; Ketzel, M.; Kukkonen, J.

    2007-08-01

    A field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17-20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm-10 μm (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3-50 nm (mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. For model comparison purposes, one of the cases was additionally computed using the aerosol process model UHMA, combined with the CAR-FMI model. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible on this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic

  5. CLEAN-ROADS project: air quality considerations after the application of a novel MDSS on winter road maintenance activities

    NASA Astrophysics Data System (ADS)

    Pretto, Ilaria; Malloci, Elisa; Tonidandel, Gabriele; Benedetti, Guido; Di Napoli, Claudia; Piazza, Andrea; Apolloni, Roberto; Cavaliere, Roberto

    2016-04-01

    on sodium chloride, which releases Na+ and Cl-, the estimation of the contribution of road salting to PM10 concentration can be carried out considering only measured concentrations of Na+ and Cl-. However, the presence of these elements might not be due exclusively to salting activities. For this reason data collected during first winter campaign were analysed using the Positive Matrix Factorization (PMF) Model developed by United States Environmental Protection Agency (EPA) to identify the presence of Na+ and Cl- in emission profiles of other PM10 sources (e.g., biomass burning, traffic) [3]. Through this study new guidelines have been defined for the optimization of current road management operations, and their applicability to other area in the Province of Trento has been assessed for future purposes. [1] Pretto I. et al., SIRWEC 2014 conference proceedings, ID:0019 (2014) [2] Ambient Air Quality and Cleaner Air for Europe (CAFE) Directive (2008/50/EC) [3] http://www.epa.gov/air-research/positive-matrix-factorization-model-environmental-data-analyses

  6. Road Surfaces And Earthquake Engineering: A Theoretical And Experimental Study

    SciTech Connect

    Pratico, Filippo Giammaria

    2008-07-08

    As is well known, road surfaces greatly affect vehicle-road interaction. As a consequence, road surfaces have a paramount influence on road safety and pavement management systems. On the other hand, earthquakes produce deformations able to modify road surface structure, properties and performance. In the light of these facts, the main goal of this paper has been confined into the modelling of road surface before, during and after the seismic event. The fundamentals of road surface texture theory have been stated in a general formulation. Models in the field of road profile generation and theoretical properties, before, during and after the earthquake, have been formulated and discussed. Practical applications can be hypothesised in the field of vehicle-road interaction as a result of road surface texture derived from deformations and accelerations caused by seismic or similar events.

  7. Road Surfaces And Earthquake Engineering: A Theoretical And Experimental Study

    NASA Astrophysics Data System (ADS)

    Praticò, Filippo Giammaria

    2008-07-01

    As is well known, road surfaces greatly affect vehicle-road interaction. As a consequence, road surfaces have a paramount influence on road safety and pavement management systems. On the other hand, earthquakes produce deformations able to modify road surface structure, properties and performance. In the light of these facts, the main goal of this paper has been confined into the modelling of road surface before, during and after the seismic event. The fundamentals of road surface texture theory have been stated in a general formulation. Models in the field of road profile generation and theoretical properties, before, during and after the earthquake, have been formulated and discussed. Practical applications can be hypothesised in the field of vehicle—road interaction as a result of road surface texture derived from deformations and accelerations caused by seismic or similar events.

  8. Technical Note: Measurement of bow tie profiles in CT scanners using radiochromic film

    SciTech Connect

    Whiting, Bruce R.; Dohatcu, Andreea C.; Evans, Joshua D.; Williamson, Jeffrey F.; Politte, David G.

    2015-06-15

    Purpose: To provide a noninvasive technique to measure the intensity profile of the fan beam in a computed tomography (CT) scanner that is cost effective and easily implemented without the need to access proprietary scanner information or service modes. Methods: The fabrication of an inexpensive aperture is described, which is used to expose radiochromic film in a rotating CT gantry. A series of exposures is made, each of which is digitized on a personal computer document scanner, and the resulting data set is analyzed to produce a self-consistent calibration of relative radiation exposure. The bow tie profiles were analyzed to determine the precision of the process and were compared to two other measurement techniques, direct measurements from CT gantry detectors and a dynamic dosimeter. Results: The radiochromic film method presented here can measure radiation exposures with a precision of ∼6% root-mean-square relative error. The intensity profiles have a maximum 25% root-mean-square relative error compared with existing techniques. Conclusions: The proposed radiochromic film method for measuring bow tie profiles is an inexpensive (∼$100 USD + film costs), noninvasive method to measure the fan beam intensity profile in CT scanners.

  9. Study of the PM₁₀ concentration variations along two intra-urban roads within a compact city.

    PubMed

    Chau, Chi Kwan; Pun-Cheng, Lillan Shuk Ching; Ng, Wai Yin; Hui, Wai Kwan

    2012-06-01

    Eighty-five measurement campaigns were performed repeatedly to compare the concentration variation profiles along two intra-urban roads-one with open configuration and the other with street canyon effect. Fixed-effects panel data analysis was applied for formulating a model to express the PM(10) concentrations along intra-urban roads in terms of parameters like nearby central monitoring data, traffic counts and meteorological conditions with an objective to analyze the PM(10) concentration variation patterns along the two roads. Our findings reveal that traffic intensity and metrological conditions exert influence on concentration variation for both types of road configurations while wind velocity only affect the pollutants removal effectiveness of open road configuration. Further analysis unveils that the PM(10) concentration distribution profiles within a compact city environment are not always uniform and are dependent on the road configuration. Considerable PM(10) concentration differences were observed along the street canyon, and 70% of their variations are attributed to variations in their road aspect ratios. By contrast, no significant concentration difference is observed at open road configurations.

  10. Relative vegetation profiles in a Neotropical forest: comparison of lidar instrumentation and field-based measurements

    NASA Astrophysics Data System (ADS)

    Sullivan, F. B.; Palace, M. W.; Ducey, M.; Czarnecki, C.; Zanin Shimbo, J.; Mota e Silva, J.

    2012-12-01

    Tropical forests are considered to be some of the most structurally complex forests in the world. Understanding vegetation height structure in these forests can aid in understanding the spatial temporal components of disturbance, from blowdowns to gap dynamics. Vegetation profiles can be used to better estimate carbon storage and flux across the landscape. Using light detection and ranging (lidar) data collected at La Selva, Costa Rica from four instruments (three airborne, one terrestrial) at four times since 2005, and field data collected in January 2012, we generated relative vegetation profiles for twenty plots in La Selva. Relative vegetation profiles were derived from lidar data by accounting for obscured plant material through a log transformation of the cumulative proportion of observations (percent canopy closure). Profiles were derived from field data using two different sets of allometric equations describing crown shape and tree height. We conducted a cluster analysis on similarity matrices developed in R (version 2.14.1) using three different metrics (sum of squares, Kullback-Leibler divergence, Kolmogorov-Smirnov D statistic) and identified general similarity between lidar profiles. Results were consistent across each of the three similarity metrics. Three distinct clusters were found, with profiles from three airborne lidar instruments, two profiles from a terrestrial lidar instrument, and profiles derived from field data forming the clusters. Our results indicate that although estimating lidar relative vegetation profiles from field data was not possible, terrestrial lidar relative vegetation profiles are generally similar to airborne relative vegetation profiles. Given the rapidity and repeatability of terrestrial lidar measurements, these results show promise for terrestrial lidar instruments to collect plot-specific data on forest structure and vertical distribution of plant material. Furthermore, identifying relationships between terrestrial and

  11. View west along Tatnic Road and Hartford Road (Route 6) ...

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

    View west along Tatnic Road and Hartford Road (Route 6) showing West Brooklyn Green, 10 Tatnic Road, and 126 Hartford Road - West Brooklyn Green, Tatnic Road & Hartford Road, Brooklyn, Windham County, CT

  12. Improved measures for the cross-national comparison of age profiles of internal migration.

    PubMed

    Bernard, Aude; Bell, Martin; Charles-Edwards, Elin

    2014-01-01

    We develop and demonstrate the application of a concise set of measures intended to encapsulate key features of the age profile of internal migration and highlight the significant differences that exist between nations in these profiles. Model schedules have been the most common method of comparing internal migration patterns but issues related to the estimation and interpretation of their parameters hinder their use for cross-national comparison. We demonstrate that the interpretation of exponential coefficients as rates of ascent and descent does not best reflect the slopes of migration age profiles, and we propose more consistent measures based on the rate of change in migration intensity. We demonstrate, through correlation and factor analysis, that most of the inter-country variance in migration age profiles is captured by the age at and intensity of peak migration. The application of these two indicators to 25 countries reveals significant differences between regions.

  13. An approach to measuring RBC haemolysis and profiling RBC mechanical fragility.

    PubMed

    Alfano, Kenneth M; Tarasev, Michael; Meines, Steven; Parunak, Gene

    2016-01-01

    Red blood cells (RBC) can be damaged by medical products, from storage or from disease. Haemolysis (cell rupture and haemoglobin release) is often a key indicator, with mechanical fragility (MF) offering the potential to assess sub-haemolytic damage as well. This article reports on a unique approach to measuring haemolysis, without the need for centrifugation or other sample separation. It also reports on employing that in measuring blood fragility (susceptibility to haemolysis) under shear stress, utilising an electromagnet to cause a bead to oscillate within a cartridge that contains the sample. Cycling between stressing and optical measurement of induced haemolysis at progressively increasing durations of stress provides a fragility profile. Sub-system-level testing shows high accuracy for the haemolysis measurements and fair consistency for MF profiling. Improving accuracy and precision of profiling is a current focus and a fully integrated and automated version of this system is under development.

  14. Radiation profiles through the atmosphere measured by an auto controlled glider aircraft

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf

    2014-05-01

    In 2011 radiation measurements through the atmosphere were made with a balloon borne short- and longwave net radiometer. These measurements were very promising and therefore new and improved sensors from Kipp&Zonen were used to equip a glider aircraft together with the standard Swiss radiosonde from Meteolabor AG. The glider serves as returning platform for the expensive and well calibrated radiation sensors. Double balloon technique is used to prevent pendulum motion during the ascent and to keep the radiation instruments as horizontal as possible. The built-in autopilot allows to return the gliderradiosonde to the launch site or to land it on predefined open space, which makes recovery much easier. The new return gliderradiosonde technique as well as new measurement possibilities will be shown. First measurements show radiation profiles through the atmosphere during different cloud conditions. Radiation profiles during different daytimes show the temporal resolution of vertical radiation profiles trough the atmosphere.

  15. Rapid measurement of charged particle beam profiles using a current flux grating

    SciTech Connect

    Paul, Samit; Chowdhury, Abhishek; Bhattacharjee, Sudeep

    2015-02-15

    The principle and physics issues of charged particle beam diagnostics using a current flux grating are presented. Unidirectional array of conducting channels with interstitial insulating layers of spacing d is placed in the beam path to capture flux of charge and electronically reproduce an exact beam current profile with density variation. The role of secondary electrons due to the impinging particle beam (both electron and ion) on the probe is addressed and a correction factor is introduced. A 2-dimensional profile of the electron beam is obtained by rotating the probe about the beam axis. Finally, a comparison of measured beam profile with a Gaussian is presented.

  16. Rapid measurement of charged particle beam profiles using a current flux grating.

    PubMed

    Paul, Samit; Chowdhury, Abhishek; Bhattacharjee, Sudeep

    2015-02-01

    The principle and physics issues of charged particle beam diagnostics using a current flux grating are presented. Unidirectional array of conducting channels with interstitial insulating layers of spacing d is placed in the beam path to capture flux of charge and electronically reproduce an exact beam current profile with density variation. The role of secondary electrons due to the impinging particle beam (both electron and ion) on the probe is addressed and a correction factor is introduced. A 2-dimensional profile of the electron beam is obtained by rotating the probe about the beam axis. Finally, a comparison of measured beam profile with a Gaussian is presented.

  17. A rocket radiobeacon experiment on the electron concentration profile measurements in the bottomside of the ionosphere

    NASA Astrophysics Data System (ADS)

    Sinelnikov, V. M.; Lvova, G. P.; Guliaeva, T. L.; Pakhomov, S. V.; Glotov, A. P.

    The possibility of measuring the electron density profile in the height interval 70-110 km with a two-frequency coherent transmitter set mounted on a 'small' geophysical rocket of type M-100 is investigated. Results are presented of measurements using the phase Doppler method carried out at middle latitudes in May 1979 and February 1980. Good consistency of the profiles measured for the D and E regions of the ionosphere with those of IRI is not always obtained, even when the correct helio and geophysic conditions of the experiments are given for calculations with IRI.

  18. Washboard Road

    NASA Astrophysics Data System (ADS)

    McElwaine, Jim; Dalziel, Stuart; Taberlet, Nicolas; Morris, Stephen

    2006-11-01

    The tendency of unpaved road surfaces to develop lateral ripples (``washboard'' or ``corrugated'' road) is annoyingly familiar to drivers on dry gravel roads. Similar ripples are well known on railroad tracks and many other rolling or sliding, load bearing surfaces. Our approach combined laboratory experiments, soft-particle direct numerical simulations and simple nonlinear dynamics models. The experiment consisted of a rotating table 60 cm in radius with a thick layer of sand forming a roadbed around the circumference. A 6 cm radius hard rubber wheel, with a support stationary in the lab frame, rolled on the sand layer. We varied the speed of the table and the details of the suspension of the wheel. The onset of the ripple pattern exhibits a sharp threshold and was strongly subcritical with a large hysteresis as a function of the speed of the table. The ripple pattern appears as small patches of travelling waves which eventually spread to the entire circumference. The ripples move slowly in the driving direction. Interesting secondary dynamics of the saturated ripples were observed. All of these effects are captured qualitatively by a 2D soft particle simulations. The simulations clearly indicate that neither compaction nor particle size segregation are crucial for the appearance of the ripples, and we present a simple model to describe the wavelength and amplitude of the ripples.

  19. Dysarthria Impact Profile: Development of a Scale to Measure Psychosocial Effects

    ERIC Educational Resources Information Center

    Walshe, Margaret; Peach, Richard K.; Miller, Nick

    2009-01-01

    Background: The psychosocial impact of acquired dysarthria on the speaker is well recognized. To date, speech-and-language therapists have no instrument available to measure this construct. This has implications for outcome measurement and for planning intervention. This paper describes the Dysarthria Impact Profile (DIP), an instrument that has…

  20. Image processing techniques for measuring non-uniform film thickness profiles

    SciTech Connect

    Nitta, S.V.; Liu, An-Hong; Plawsky, J.L.; Wayner, P.C. Jr.

    1996-12-31

    The long term objective of this research program is to determine the fluid flow and drying characteristics of thin liquid/solid films using image processing techniques such as Image Analyzing Interferometry (IAI) and Image Scanning Ellipsometry (ISE). The primary purpose of this paper is to present experimental data on the effectiveness of IAI and ISE to measure nonuniform film thickness profiles. Steady-state, non-isothermal profiles of evaporating films were measured using IAI. Transient thickness profiles of a draining film were measured using ISE. The two techniques are then compared and contrasted. The ISE can be used to measure transient as well as steady-state profiles of films with thickness ranging from 1 nm to > 20 {mu}m, whereas IAI can be used to directly measure Steady-state and transient profiles of only films thicker than about 100 nm. An evaluation of the reflected intensity can be used to extend the use of the IAI below 100 nm.

  1. Measurement of temperature profiles in flames by emission-absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Simmons, F. S.; Arnold, C. B.; Lindquist, G. H.

    1972-01-01

    An investigation was conducted to explore the use of infrared and ultraviolet emission-absorption spectroscopy for determination of temperature profiles in flames. Spectral radiances and absorptances were measured in the 2.7-micron H2O band and the 3064-A OH band in H2/O2 flames for several temperature profiles which were directly measured by a sodium line-reversal technique. The temperature profiles, determined by inversion of the infrared and ultraviolet spectra, showed an average disagreement with line-reversal measurements of 50 K for the infrared and 200 K for the ultraviolet at a temperature of 2600 K. The reasons for these discrepancies are discussed in some detail.

  2. Investigations on the spatial resolution of autocollimator-based slope measuring profilers

    NASA Astrophysics Data System (ADS)

    Siewert, F.; Buchheim, J.; Höft, T.; Zeschke, T.; Schindler, A.; Arnold, T.

    2013-05-01

    During the last decade, autocollimator-based slope measuring profilers like the Nanometer Optical Component Measuring Machine (NOM) at BESSY-II have become standard instrument for the ultra-precise characterization of synchrotron optics with nanometer accuracy. Due to the increasing demand for highest accuracy, which can be provided by these profilers, further investigations are necessary to understand the performance of these instruments. Besides the achievable accuracy, it is of particular interest to characterize the possible spatial resolution of such instrumentation. The performance of the BESSY-NOM was characterized by means of sinusoidal and chirped surface profiles. A dedicated sample was prepared using the Atmospheric Plasma Jet Machining technology at the IOM—Leibniz-Institut für Oberflächenmodifizierung e.V. We report on our tests on the NOM, the interferometer measurements done for comparison as well as the sample preparation.

  3. Fiber Optic Picosecond Laser Pulse Transmission Line for Hydrogen Ion Beam Profile Measurement

    SciTech Connect

    Liu, Yun; Huang, Chunning; Aleksandrov, Alexander V

    2013-01-01

    We present a fiber optic laser pulse transmission line for non-intrusive longitudinal profile measurement of the hydrogen ion (H-) beam at the front-end of the Spallation Neutron Source (SNS) accelerator. The 80.5 MHz, 2.5 ps, multi-killowatt optical pulses are delivered to the accelerator beam line through a large mode area polarization maintaining optical fiber to ensure a high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter and pulse width broadening over a 100-ft fiber line are experimentally investigated. A successful measurement of the H- beam microbunch (~130 ps) profile is obtained. Our experiment is the first demonstration of particle beam profile diagnostics using fiber optic laser pulse transmission line.

  4. Fiber optic picosecond laser pulse transmission line for hydrogen ion beam longitudinal profile measurement.

    PubMed

    Huang, Chunning; Liu, Yun; Aleksandrov, Alexander

    2013-07-01

    We present a fiber optic laser pulse transmission line for nonintrusive longitudinal profile measurement of the hydrogen ion (H(-)) beam at the front-end of the Spallation Neutron Source accelerator. The 80.5 MHz, 2.5 ps, multikilowatt optical pulses are delivered to the accelerator beam line through a large-mode-area polarization-maintaining optical fiber to ensure high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter, and pulse width broadening over a 30 m long fiber line are experimentally investigated. A successful measurement of the H(-) beam microbunch (~130 ps) profile is obtained. The experiment is the first demonstration to our knowledge of particle beam profile diagnostics using a fiber optic laser pulse transmission line.

  5. Monochromatic heterodyne fiber-optic profile sensor for spatially resolved velocity measurements with frequency division multiplexing

    SciTech Connect

    Pfister, Thorsten; Buettner, Lars; Shirai, Katsuaki; Czarske, Juergen

    2005-05-01

    Investigating shear flows is important in technical applications as well as in fundamental research. Velocity measurements with high spatial resolution are necessary. Laser Doppler anemometry allows nonintrusive precise measurements, but the spatial resolution is limited by the size of the measurement volume to {approx}50 {mu}m. A new laser Doppler profile sensor is proposed, enabling determination of the velocity profile inside the measurement volume. Two fringe systems with contrary fringe spacing gradients are generated to determine the position as well as the velocity of passing tracer particles. Physically discriminating between the two measuring channels is done by a frequency-division-multiplexing technique with acousto-optic modulators. A frequency-doubled Nd:YAG laser and a fiber-optic measuring head were employed, resulting in a portable and flexible sensor. In the center of the measurement volume of {approx}1-mm length, a spatial resolution of {approx}5 {mu}m was obtained. Spatially resolved measurements of the Blasius velocity profile are presented. Small velocities as low as 3 cm/s are measured. The sensor is applied in a wind tunnel to determine the wall shear stress of a boundary layer flow. All measurement results show good agreement with the theoretical prediction.

  6. Road user behaviour changes following a self-explaining roads intervention.

    PubMed

    Mackie, Hamish W; Charlton, Samuel G; Baas, Peter H; Villasenor, Pablo C

    2013-01-01

    The self-explaining roads (SER) approach uses road designs that evoke correct expectations and driving behaviours from road users to create a safe and user-friendly road network. Following the implementation of an SER process and retrofitting of local and collector roads in a suburb within Auckland City, lower speeds on local roads and less variation in speed on both local and collector roads were achieved, along with a closer match between actual and perceived safe speeds. Preliminary analyses of crash data shows that the project has resulted in a 30% reduction crash numbers and an 86% reduction in crash costs per annum, since the road changes were completed. In order to further understand the outcomes from this project, a study was carried out to measure the effects of the SER intervention on the activity and behaviour of all road users. Video was collected over nine separate days, at nine different locations, both before and after SER construction. Road user behaviour categories were developed for all potential road users at different location types and then used to code the video data. Following SER construction, on local roads there was a relatively higher proportion of pedestrians, less uniformity in vehicle lane keeping and less indicating by motorists along with less through traffic, reflecting a more informal/low speed local road environment. Pedestrians were less constrained on local roads following SER construction, possibly reflecting a perceptually safer and more user-friendly environment. These behaviours were not generally evident on collector roads, a trend also shown by the previous study of speed changes. Given that one of the objectives of SER is to match road user behaviour with functionally different road categories, the road user behaviour differences demonstrated on different road types within the SER trial area provides further reinforcement of a successful SER trial.

  7. Profile measurement of transparent inclined surface with transmitted differential interference contrast shearing interferometer.

    PubMed

    Yu, Sheng-Kang; Chen, Wei-Lun; Liu, Ting-Kun; Lin, Shih-Chieh

    2012-08-27

    A quantitative phase shifting differential interference contrast (PS-DIC) shearing interferometer is adopted to measure the profile of transparent specimen with inclined surface. The effects of the incline angle on DIC measurement accuracy were studied. The optical model of the test system was constructed and the measurement of surface with various incline angles ranging from 5° to 60° was simulated. The experiments validate the simulation model and show the feasibility of profile reconstruction of inclined structure. It is interested to find that even with an inclined angle of 15°, unwrapping technique is required to make the measurement more accurate. In addition, the measurement can be further improved by taking into account the effects of the change in shear distance on the optical path difference. This study provides useful information that should be considered for complex geometry measurement with quantitative DIC technique.

  8. Development of ultrasonic pulse-train Doppler method for velocity profile and flowrate measurement

    NASA Astrophysics Data System (ADS)

    Wada, Sanehiro; Furuichi, Noriyuki; Shimada, Takashi

    2016-11-01

    We present a novel technique for measuring the velocity profile and flowrate in a pipe. This method, named the ultrasonic pulse-train Doppler method (UPTD), has the advantages of expanding the velocity range and setting the smaller measurement volume with low calculation and instrument costs in comparison with the conventional ultrasonic pulse Doppler method. The conventional method has limited measurement of the velocity range due to the Nyquist sampling theorem. In addition, previous reports indicate that a smaller measurement volume increases the accuracy of the measurement. In consideration of the application of the conventional method to actual flow fields, such as industrial facilities and power plants, the issues of velocity range and measurement volume are important. The UPTD algorithm, which exploits two pulses of ultrasound with a short interval and envelope detection, is proposed. Velocity profiles calculated by this algorithm were examined through simulations and excellent agreement was found in all cases. The influence of the signal-to-noise ratio (SNR) on the algorithm was also estimated. The result indicates that UPTD can measure velocity profiles with high accuracy, even under a small SNR. Experimental measurements were conducted and the results were evaluated at the national standard calibration facility of water flowrate in Japan. Every detected signal forms a set of two pulses and the enveloped line can be observed clearly. The results show that UPTD can measure the velocity profiles over the pipe diameter, even if the velocities exceed the measurable velocity range. The measured flowrates were under 0.6% and the standard deviations for all flowrate conditions were within  ±0.38%, which is the uncertainty of the flowrate measurement estimated in the previous report. In conclusion, UPTD provides superior accuracy and expansion of the velocity range.

  9. Drift reduction in a scanning electrostatic force microscope for surface profile measurement

    NASA Astrophysics Data System (ADS)

    Jia, Zhigang; Ito, So; Goto, Shigeaki; Hosobuchi, Keiichiro; Shimizu, Yuki; Gao, Wei

    2014-09-01

    The influence of drifts on the measurement results of an electrostatic force microscope (EFM) based on a dual-height method for surface profile measurement is analyzed. Two types of drifts and their influence on the EFM measurement are discussed by computer simulation. It is figured out that the mechanical drift has a larger impact compared to the resonance frequency drift for the specific EFM with the conventional round-trip scan mode. It is also verified that the profile reconstruction algorithm of the dual-height method for separating the electric property distribution and the surface profile of the surface has an effect of magnifying the drift error in the result of surface profile measurement, which is a much more significant measurement of uncertainty sources for the developed EFM compared with an ordinary scanning probe microscope (SPM). A new vertical reciprocating scan (VRS) mode is then employed to reduce the influences of the drifts. The feasibility of the VRS mode is demonstrated by computer simulation and measurement experiments with a diffraction grating.

  10. Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe

    SciTech Connect

    Walkden, N. R.; Adamek, J.; Komm, M.; Allan, S.; Elmore, S.; Fishpool, G.; Harrison, J.; Kirk, A.; Dudson, B. D.

    2015-02-15

    The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP potential and the floating potential, the electron temperature can be measured, which is compared with the Thomson scattering (TS) diagnostic. Excellent agreement between the two diagnostics is obtained when secondary electron emission is accounted for in the floating potential. From the BPP profile, an estimate of the radial electric field is extracted which is shown to be of the order ∼1 kV/m and increases with plasma current. Corrections to the BPP measurement, constrained by the TS comparison, introduce uncertainty into the E{sub R} measurements. The uncertainty is most significant in the electric field well inside the separatrix. The electric field is used to estimate toroidal and poloidal rotation velocities from E × B motion. This paper further demonstrates the ability of the ball pen probe to make valuable and important measurements in the boundary plasma of a tokamak.

  11. Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe.

    PubMed

    Walkden, N R; Adamek, J; Allan, S; Dudson, B D; Elmore, S; Fishpool, G; Harrison, J; Kirk, A; Komm, M

    2015-02-01

    The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP potential and the floating potential, the electron temperature can be measured, which is compared with the Thomson scattering (TS) diagnostic. Excellent agreement between the two diagnostics is obtained when secondary electron emission is accounted for in the floating potential. From the BPP profile, an estimate of the radial electric field is extracted which is shown to be of the order ∼1 kV/m and increases with plasma current. Corrections to the BPP measurement, constrained by the TS comparison, introduce uncertainty into the ER measurements. The uncertainty is most significant in the electric field well inside the separatrix. The electric field is used to estimate toroidal and poloidal rotation velocities from E × B motion. This paper further demonstrates the ability of the ball pen probe to make valuable and important measurements in the boundary plasma of a tokamak.

  12. Interfacial water dielectric-permittivity-profile measurements using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Teschke, O.; Ceotto, G.; de Souza, E. F.

    2001-07-01

    The arrangement of water molecules at charged aqueous interfaces is an important question in biology, electrochemistry, and geochemistry. Theoretical studies suggest that the molecules become arranged in several layers adjacent to a solid interface. Using atomic force microscopy we have measured the water dielectric-permittivity profile perpendicular to mica surfaces. The measured variable permittivity profile starting at ɛ~4 at the interface and increasing to ɛ=80 about 10 nm from the surface suggests a reorientation of water molecule dipoles in the presence of the mica interfacial charge.

  13. Interfacial water dielectric-permittivity-profile measurements using atomic force microscopy.

    PubMed

    Teschke, O; Ceotto, G; de Souza, E F

    2001-07-01

    The arrangement of water molecules at charged aqueous interfaces is an important question in biology, electrochemistry, and geochemistry. Theoretical studies suggest that the molecules become arranged in several layers adjacent to a solid interface. Using atomic force microscopy we have measured the water dielectric-permittivity profile perpendicular to mica surfaces. The measured variable permittivity profile starting at epsilon approximately 4 at the interface and increasing to epsilon=80 about 10 nm from the surface suggests a reorientation of water molecule dipoles in the presence of the mica interfacial charge. PMID:11461268

  14. Simultaneous Measurements of Water Vapor Profiles From Airborne MIR and LASE

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Racette, P.; Triesky, M. E.; Browell, E. V.; Ismail, S.; Chang, L. A.

    1997-01-01

    A NASA ER-2 aircraft flight with both Millimeter-wave Imaging radiometer (MIR) and lidar Atmospheric Sensing Experiment (LASE) was made over ocean areas in the eastern United States on September 25, 1995. The water vapor profiles derived from both instruments under both clear and cloudy conditions are compared in this paper. It is shown that good agreement is found between the MIR-derived and the LASE-measured water vapor profiles over the areas of clear-sky condition. In the cloudy areas, the MIR-retrieved values at the altitudes of the cloud layers and below are generally higher than those measured by the LASE.

  15. Ozonesonde profiles from the West Pacific Warm Pool: measurements and validation

    NASA Astrophysics Data System (ADS)

    Newton, R.; Vaughan, G.; Ricketts, H. M. A.; Pan, L. L.; Weinheimer, A. J.; Chemel, C.

    2016-01-01

    We present a series of ozonesonde profiles measured from Manus Island, Papua New Guinea, during February 2014, with new insights on the calibration of ozonesondes for measurements in the tropical troposphere. The experiment formed a part of a wider airborne campaign involving three aircraft based in Guam, to characterise the atmospheric composition above the tropical West Pacific in unprecedented detail. Thirty-nine ozonesondes were launched between 2 and 25 February of which 34 gave good ozone profiles. Particular attention was paid to evaluating the background current of the ozonesondes, as this can amount to half the measured signal in the tropical tropopause layer (TTL). An unexpected contamination event affected the measurements and required a departure from standard operating procedures for the ozonesondes. The most significant departure was not exposing the sondes to ozone during preparation, which meant that the background current remained stable before launch. Comparison with aircraft measurements allows validation of the measured ozone profiles and confirms that for well-characterized sondes (background current ˜ 50 nA) a constant background current could be assumed throughout the profile, equal to the minimum value measured during preparation just before launch. From this set of 34 ozonesondes, the minimum reproducible ozone concentration measured in the TTL was 12-13 ppbv; no examples of ozone concentrations < 5 ppbv, as reported by other recent papers, were measured. The lowest ozone concentrations coincided with outflow from extensive deep convection to the east of Manus, consistent with uplift of ozone-poor air from the boundary layer. However, these minima were lower than the ozone concentration measured through most of the boundary layer, and were matched only by measurements at the surface in Manus.

  16. Optical bi-sensorial measurement system for production control of extruded profiles

    NASA Astrophysics Data System (ADS)

    Weckenmann, A.; Bernstein, J.

    2008-09-01

    Extruded profiles are semi-finished products (made out of steel, brass, aluminum, synthetics...) which are appointed for wide applications in manufacturing of technical products. As yet used optical sensors in process control working to the shading technology detect the object's shadow orthographically to the axis of illumination. As a consequence they record it unattached by the profiles coat in measurement range at any point of the measured profile with high precision. As a matter of fact, concave zones cannot be captured. Alternatively the measurement of concave zones can be arranged by light-section systems. These do not comply with the required accuracy, are comparatively slow and moreover affected by dislocations of the section of the profile. A measurement system including a light-section and a shading system combines the advantages of both optical systems. It is to serve with a reliable conception for the assembly of a bi-sensorial measurement system consisting of both systems as well as suitable methods of analysis for the in-line inspection of concave profiles. As a result it contains conclusions concerning requirements of the light source, the arrangement of this source and the cameras, obtainable precision and sampling rate as well as the essential synchronization of both systems. After designing an appropriate prototype, the selected light-section system and the shading system will be synchronized and aligned. Therefore, the metered geometrical data will be merged for the evaluation of form deviation. So, developed and adapted software supports and contains proposals to the uncertainty after successful tests. The system and a calibration method will be proved in production where robustness will be a most critical despite of heat, dust and vibrations. The target uncertainty of less than 0.1 mm at every section of the profiles coat has to be met.

  17. Prospects for measuring neutron-star masses and radii with X-ray pulse profile modeling

    SciTech Connect

    Psaltis, Dimitrios; Özel, Feryal; Chakrabarty, Deepto E-mail: fozel@email.arizona.edu

    2014-06-01

    Modeling the amplitudes and shapes of the X-ray pulsations observed from hot, rotating neutron stars provides a direct method for measuring neutron-star properties. This technique constitutes an important part of the science case for the forthcoming NICER and proposed LOFT X-ray missions. In this paper, we determine the number of distinct observables that can be derived from pulse profile modeling and show that using only bolometric pulse profiles is insufficient for breaking the degeneracy between inferred neutron-star radius and mass. However, we also show that for moderately spinning (300-800 Hz) neutron stars, analysis of pulse profiles in two different energy bands provides additional constraints that allow a unique determination of the neutron-star properties. Using the fractional amplitudes of the fundamental and the second harmonic of the pulse profile in addition to the amplitude and phase difference of the spectral color oscillations, we quantify the signal-to-noise ratio necessary to achieve a specified measurement precision for neutron star radius. We find that accumulating 10{sup 6} counts in a pulse profile is sufficient to achieve a ≲ 5% uncertainty in the neutron star radius, which is the level of accuracy required to determine the equation of state of neutron-star matter. Finally, we formally derive the background limits that can be tolerated in the measurements of the various pulsation amplitudes as a function of the system parameters.

  18. [Raman Lidar measuring tropospheric temperature profiles with many rotational Raman lines].

    PubMed

    Su, Jia; Zhang, Yin-chao; Hu, Shun-xing; Cao, Kai-fa; Zhao, Pei-tao; Wang, Shao-lin; Xie, Jun

    2008-08-01

    Due to lower tropospheric aerosols, the Rayleigh and vibrational Raman methods can't measure lower tropospheric temperature profiles accurately. By using N2 and O2 molecular pure rotational Raman scattering signals, lower tropospheric temperature profiles can be gained without influence of lower tropospheric aerosols. So we decide to use a pure rotational Raman Lidar to get lower tropospheric temperature profiles. At present, because the most light-splitting systems of pure rotational Raman Lidar measure temperature by gaining a single rotational Raman line, the signal to noise ratio (SNR) of these Lidar systems are very low. So we design a new kind of Lidar light-splitting system which can sum different rotational Raman lines and it can improve SNR And we can find the sensitivity of the temperature of the ratios of multi rotational Raman lines is as same as single rotational Raman line's through theoretical analysis. Moreover, we can obtain the temperature profiles with good SNR fromthis new the system with a normal laser and a small telescope up to several kilometers. At last, with the new light-splitting system, the lower tropospheric temperature profiles are measured from 0.3 km to 5 km altitude. They agree well with radiosonde observations, which demonstrate the results of our rotational Raman lidar are reasonable.

  19. Using CART to segment road images

    NASA Astrophysics Data System (ADS)

    Davies, Bob; Lienhart, Rainer

    2006-01-01

    The 2005 DARPA Grand Challenge is a 132 mile race through the desert with autonomous robotic vehicles. Lasers mounted on the car roof provide a map of the road up to 20 meters ahead of the car but the car needs to see further in order to go fast enough to win the race. Computer vision can extend that map of the road ahead but desert road is notoriously similar to the surrounding desert. The CART algorithm (Classification and Regression Trees) provided a machine learning boost to find road while at the same time measuring when that road could not be distinguished from surrounding desert.

  20. Calibrating system errors of large scale three-dimensional profile measurement instruments by subaperture stitching method.

    PubMed

    Dong, Zhichao; Cheng, Haobo; Feng, Yunpeng; Su, Jingshi; Wu, Hengyu; Tam, Hon-Yuen

    2015-07-01

    This study presents a subaperture stitching method to calibrate system errors of several ∼2  m large scale 3D profile measurement instruments (PMIs). The calibration process was carried out by measuring a Φ460  mm standard flat sample multiple times at different sites of the PMI with a length gauge; then the subaperture data were stitched together using a sequential or simultaneous stitching algorithm that minimizes the inconsistency (i.e., difference) of the discrete data in the overlapped areas. The system error can be used to compensate the measurement results of not only large flats, but also spheres and aspheres. The feasibility of the calibration was validated by measuring a Φ1070  mm aspheric mirror, which can raise the measurement accuracy of PMIs and provide more reliable 3D surface profiles for guiding grinding, lapping, and even initial polishing processes. PMID:26193139

  1. Measurement of the density profile of pure and seeded molecular beams by femtosecond ion imaging

    SciTech Connect

    Meng, Congsen; Janssen, Maurice H. M.

    2015-02-15

    Here, we report on femtosecond ion imaging experiments to measure the density profile of a pulsed supersonic molecular beam. Ion images are measured for both a molecular beam and bulk gas under identical experimental conditions via femtosecond multiphoton ionization of Xe atoms. We report the density profile of the molecular beam, and the measured absolute density is compared with theoretical calculations of the centre line beam density. Subsequently, we discuss reasons accounting for the differences between measurements and calculations and propose that strong skimmer interference is the most probable cause for the differences. Furthermore, we report on experiments measuring the centre line density of seeded supersonic beams. The femtosecond ion images show that seeding the heavy Xe atom at low relative seed fractions (1%-10%) in a light carrier gas like Ne results in strong relative enhancements of up to two orders of magnitude.

  2. Dose rate and beam profile measurement of proton beam using a flat panel detector

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Min

    2015-10-01

    A 20-MeV or 100-MeV proton beam is provided to users for their proton beam irradiation experiments at KOrea Multi-Purpose Accelerator Complex. Radiochromic film (Gafchromic / HDV2) has been used to measure the dose rate and the profile of an incident proton beam during irradiation experiments. However, such measurements using radiochromic film have some inconveniences because an additional scanning process of is required to quantify the film's image. Therefore, we tried to measure the dose rate and beam profile by using a flat panel detector (FPD), which was developed for X-ray radiography as a substitute for radiochromic film because the FPD can measure the beam profile and the dose rate directly through a digitized image with a high spatial resolution. In this work, we investigated the feasibility of using a FPD as a substitute for radiochromic film. The preliminary results for the beam profile and the dose rate measured by using the flat panel detector are reported in the paper.

  3. Measurement of Turbulence with Acoustic Doppler Current Profilers - Sources of Error and Laboratory Results

    USGS Publications Warehouse

    Nystrom, E.A.; Oberg, K.A.; Rehmann, C.R.; ,

    2002-01-01

    Acoustic Doppler current profilers (ADCPs) provide a promising method for measuring surface-water turbulence because they can provide data from a large spatial range in a relatively short time with relative ease. Some potential sources of errors in turbulence measurements made with ADCPs include inaccuracy of Doppler-shift measurements, poor temporal and spatial measurement resolution, and inaccuracy of multi-dimensional velocities resolved from one-dimensional velocities measured at separate locations. Results from laboratory measurements of mean velocity and turbulence statistics made with two pulse-coherent ADCPs in 0.87 meters of water are used to illustrate several of inherent sources of error in ADCP turbulence measurements. Results show that processing algorithms and beam configurations have important effects on turbulence measurements. ADCPs can provide reasonable estimates of many turbulence parameters; however, the accuracy of turbulence measurements made with commercially available ADCPs is often poor in comparison to standard measurement techniques.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  5. Oceanographic lidar profiles compared with estimates from in situ optical measurements.

    PubMed

    Lee, Jennifer H; Churnside, James H; Marchbanks, Richard D; Donaghay, Percy L; Sullivan, James M

    2013-02-01

    Oceanographic lidar profiles measured in an aerial survey were compared with in situ measurements of water optical properties made from a surface vessel. Experimental data were collected over a two-week period in May 2010 in East Sound, Washington. Measured absorption and backscatter coefficients were used with the volume-scattering function in a quasi-single-scattering model to simulate an idealized lidar return, and this was convolved with the measured instrument response to accurately reproduce the measured temporal behavior. Linear depth-dependent depolarization from the water column and localized depolarization from scattering layers are varied to fine tune the simulated lidar return. Sixty in situ measurements of optical properties were correlated with nearly collocated and coincident lidar profiles; our model yielded good matches (±3 dB to a depth of 12 m) between simulated and measured lidar profiles for both uniform and stratified waters. Measured attenuation was slightly higher (5%) than diffuse attenuation for the copolarized channel and slightly lower (8%) for the cross-polarized channel.

  6. Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experiment Spherical Torus

    NASA Astrophysics Data System (ADS)

    Kim, YooSung; Shi, Yue-Jiang; Yang, Jeong-hun; Kim, SeongCheol; Kim, Young-Gi; Dang, Jeong-Jeung; Yang, Seongmoo; Jo, Jungmin; Oh, Soo-Ghee; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-11-01

    Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of Hα and Hβ radiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.

  7. Modeling of measured target pressure profiles in three hypervelocity impact experiments

    SciTech Connect

    Gerassimenko, M

    2000-10-11

    A 24 g aluminum sphere was shot at a sparse array of cylinders with nominal initial projectile velocity of 4 and 5 km/s. Pressure profiles were measured with cased carbon resistor gages at two locations in a projectile impacted water filled cylinder and two of its neighbors on three shots. The pressure maxima were in the 1-13 kbars range. The experiments are modeled with the ALE3D code and several techniques are used to concentrate zoning at places of interest. There is excellent agreement between the measured and calculated pressure profiles for two shots and good agreement for the third. Comparison of the calculated pressure profiles with those from more refined calculations for two shots suggest that we are near convergence with respect to zone size.

  8. Saturation Profiles from Lab-scale Permittivity Measurements and 2-Phase Flow Models.

    NASA Astrophysics Data System (ADS)

    Gorriti, A. G.

    2005-05-01

    Laboratory fluid-flow experiments through soils are important to study the different fluid-flow processes that occur in the subsurface of the Earth. Most of them, measure the flow conditions at the entry and exit points of the sample, while, the saturation profile in the sample, and its change with time, is unknown. Until now, only very expensive and time-consuming techniques, such as CT or MRI scans, could provide information about the flow in the sample. Now, for the first time, we have developed a technique to measure the saturation profile of soil samples that is cheap and easy. With this technique, we obtain the saturation profiles from the inversion of permittivity measurements. The experimental set-up consists of a coaxial transmission line with a large sample holder (3 cm of diameter and 10 cm long) that allows for fluid-flow through the sample. The complex electric permittivity is reconstructed, per frequency, from the electromagnetic reflection and transmission responses of the line. Relative changes in the permittivity in the order of 1% can be detected over a wide frequency band up to 3 GHz, while the lowest usable frequency depends on the permittivity of the material filling the sample holder. The accurate measurements of permittivity performed with the described tool assume that the measured quantity is an effective property. The assumption then is that the sample is homogeneous. Under non-flowing conditions this can be a reasonable assumption, but during a flow experiment it cannot. This is clear from the fact that the reconstruction of the permittivity of these samples is not successful. The model of the sample must be modified to include the resulting heterogeneity. This is done by assuming a multilayered sample, each layer considered to be homogeneous with a constant permittivity and a known frequency dependence. Minimizing a cost function involving the measured reflection and transmission coefficients and the modelled response of the multilayered

  9. Vegetation profiles in tropical forests from multibaseline interferometric synthetic aperture radar, field, and lidar measurements

    NASA Astrophysics Data System (ADS)

    Treuhaft, R. N.; Chapman, B. D.; Dos Santos, J. R.; GonçAlves, F. G.; Dutra, L. V.; GraçA, P. M. L. A.; Drake, J. B.

    2009-12-01

    This paper addresses the estimation of vertical vegetation density profiles from multibaseline interferometric synthetic aperture radar (InSAR) data from the AirSAR aircraft at C band over primary, secondary, and abandoned-pasture stands at La Selva Biological Station, Costa Rica in 2004. Profiles were also estimated from field data taken in 2006 and lidar data taken with the LVIS, 25 m spot instrument in 2005. After motivating the study of tropical forest profiles based on their role in the global carbon cycle, ecosystem state, and biodiversity, this paper describes the InSAR, field, and lidar data acquisitions and analyses. Beyond qualitative agreement between profiles from the 3 measurement techniques, results show that InSAR and lidar profile-averaged mean height have RMS scatters about field-measured means of 3.4 m and 3.2 m, 16% and 15% of the average mean height, respectively. InSAR and lidar standard deviations of the vegetation distribution have RMS scatters about the field standard deviations of 1.9 m and 1.5 m, or 27% and 21%, respectively. Dominant errors in the profile-averaged mean height for each measurement technique were modeled. InSAR inaccuracies, dominated by ambiguities in finding the ground altitude and coherence calibration, together account for about 3 m of InSAR error in the mean height. The dominant, modeled error for the field measurements was the inaccuracy in modeling the trees as uniformly filled volumes of leaf area, inducing field errors in mean height of about 3 m. The dominant, modeled lidar error, also due to finding the ground, was 2 m.

  10. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    SciTech Connect

    Falabella, S.

    1988-05-11

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10/sup 12/cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs.

  11. Comparison of GOME-2/Metop-A ozone profiles with GOMOS, OSIRIS and MLS measurements

    NASA Astrophysics Data System (ADS)

    Määttä, A.; Tuinder, O. N. E.; Tukiainen, S.; Sofieva, V.; Tamminen, J.

    2015-07-01

    This paper presents a comparison of vertical ozone profiles retrieved by the Ozone ProfilE Retrieval Algorithm (OPERA) from the Global Ozone Monitoring Experiment 2 (GOME-2) measurements on board Metop-A with high-vertical-resolution ozone profiles by Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and Infrared Imager System (OSIRIS) and Microwave Limb Sounder (MLS). The comparison, with global coverage, focuses on the stratosphere and the lower mesosphere and covers the period from March 2008 until the end of 2011. The comparison shows an agreement of the GOME-2 ozone profiles with those of GOMOS, OSIRIS and MLS within ±15 % in the altitude range from 15 km up to ~ 35-40 km depending on latitude. The GOME-2 ozone profiles from non-degradation corrected radiances have a tendency to a systematic negative bias with respect to the reference data above ~ 30 km. The GOME-2 bias with respect to the high-vertical resolution instruments depends on season, with the strongest dependence observed at high latitudes.

  12. Sediment profiles of less commonly determined elements measured by Laser Ablation ICP-MS.

    PubMed

    Dolor, Marvourneen K; Helz, George R; McDonough, William F

    2009-01-01

    Anthropogenic influences on trace element profiles in dated sediments from estuaries have been often documented, with the vast majority of studies focusing on a short list of high-abundance trace elements. Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) provides a new approach that minimizes sample preparation and contamination while yielding data on a much larger list of elements simultaneously. We present concentrations and enrichment factor profiles for 22 elements at a locality that is 50 km southeast of Baltimore, the principal industrial city on Chesapeake Bay. Samples representing deposition over almost the entire 20th century were obtained from two archived cores collected 20 years apart. The following elements exhibit profiles consistent with a strong anthropogenic influence, i.e. enrichment after 1920 followed by decline after ca.1980, possibly reflecting increased regulatory efforts: Mn, Co, Cu, Zn, Ag, Cd, In, Sn, Sb, Te, Tl, Pb and Bi. As expected, the redox-sensitive elements: Mo, Re and U have similar profiles to one another. Previously, the potentially hazardous elements, Ag, In, Sb, Te, Tl and Bi, have been measured only rarely in estuarine sediments and never in Chesapeake Bay. Our discovery that their profiles track those of well-known pollutants underscores a need to investigate their sources, transport and biogeochemical behavior. Several rarely determined trace elements, Ga, Ge and Nb, exhibit trendless profiles, as do the major elements, Ti and Fe.

  13. Measure profile surrogates: A method to validate the performance of epileptic seizure prediction algorithms

    NASA Astrophysics Data System (ADS)

    Kreuz, Thomas; Andrzejak, Ralph G.; Mormann, Florian; Kraskov, Alexander; Stögbauer, Harald; Elger, Christian E.; Lehnertz, Klaus; Grassberger, Peter

    2004-06-01

    In a growing number of publications it is claimed that epileptic seizures can be predicted by analyzing the electroencephalogram (EEG) with different characterizing measures. However, many of these studies suffer from a severe lack of statistical validation. Only rarely are results passed to a statistical test and verified against some null hypothesis H0 in order to quantify their significance. In this paper we propose a method to statistically validate the performance of measures used to predict epileptic seizures. From measure profiles rendered by applying a moving-window technique to the electroencephalogram we first generate an ensemble of surrogates by a constrained randomization using simulated annealing. Subsequently the seizure prediction algorithm is applied to the original measure profile and to the surrogates. If detectable changes before seizure onset exist, highest performance values should be obtained for the original measure profiles and the null hypothesis. “The measure is not suited for seizure prediction” can be rejected. We demonstrate our method by applying two measures of synchronization to a quasicontinuous EEG recording and by evaluating their predictive performance using a straightforward seizure prediction statistics. We would like to stress that the proposed method is rather universal and can be applied to many other prediction and detection problems.

  14. Profile measurements and OMI NO2 retrievals: New results from validation campaigns

    NASA Astrophysics Data System (ADS)

    Bucsela, E. J.; Celarier, E. A.; Gleason, J. F.; Cohen, R. C.; Bertram, T. H.; Brinksma, E.; Veefkind, P.; Swart, D.; Berkhout, S.; Martin, R. V.

    2005-12-01

    The retrieval of atmospheric NO2 from Ozone Monitoring Instrument (OMI) measurements requires a variety of a priori information. In particular, accurate knowledge of the vertical distribution of relative NO2 concentrations in the troposphere is needed to compute air mass factors (AMFs) for converting observed slant column densitites to tropospheric vertical column densities. Until recently, few measurements of tropospheric NO2 vertical profiles existed, and the profiles used in the retrieval algorithm were estimated from models. New data are now available from aircraft campaigns, such as the Intercontinental Chemical Transport Experiment (INTEX-A) in 2004 and the Polar AURA Validation Experiment(PAVE) in January-February 2005. Ground-based instruments during the Dutch Aerosol and Nitrogen Dioxide Experiments for Validation of OMI and SCHIAMACHY (DANDELIONS) have provided tropospheric NO2 measurements at Cabauw, The Netherlands, during OMI overpasses in May-June 2005. Together, these new measurements can help validate total NO2 column amounts from OMI and improve the a priori profiles for the OMI NO2 algorithm. We discuss the results from the validation campaigns in light of the most recent OMI data and examine the effects of improved profile information on AMF estimates.

  15. Return glider radiosonde to measure temperature, humidity and radiation profiles through the atmosphere

    NASA Astrophysics Data System (ADS)

    Kraeuchi, Andreas; Philipona, Rolf

    2015-04-01

    Very promising radiation profile measurements through the atmosphere were made in 2011 with a balloon borne short- and longwave net radiometer. New and improved radiation sensors from Kipp&Zonen are now used in a glider aircraft together with a standard Swiss radiosonde from Meteolabor AG. This new return glider radiosonde (RG-R), is lifted up with double balloon technique to prevent pendulum motion and to keep the radiation instruments as horizontal as possible during the ascent measuring phase. The RG-R is equipped with a mechanism that allows to release the radiosonde at a preset altitude, and an autopilot allowing to fly the radiosonde back to the launch site and to land it savely with a parachute at a preset location. The return glider radiosonde technique as well as new measurement possibilities will be shown. First measurements show temperature, humidity and radiation profiles through the atmosphere up to 30 hPa (24 km) during different atmospheric conditions. Radiation profiles during different daytimes show possibilities with respect to temporal resolution of vertical radiation profiles trough the atmosphere.

  16. Plasma Profile Measurements for Laser Fusion Research with the Nike KrF Laser

    NASA Astrophysics Data System (ADS)

    Oh, Jaechul; Weaver, J. L.; Serlin, V.; Obenschain, S. P.

    2015-11-01

    The grid image refractometer of the Nike laser facility (Nike-GIR) has demonstrated the capability of simultaneously measuring electron density (ne) and temperature (Te) profiles of coronal plasma. For laser plasma instability (LPI) research, the first Nike-GIR experiment successfully measured the plasma profiles in density regions up to ne ~ 4 ×1021 cm-3 (22% of the critical density for 248 nm light of Nike) using an ultraviolet probe laser (λp = 263 nm). The probe laser has been recently replaced with a shorter wavelength laser (λp = 213 nm, a 5th harmonic of the Nd:YAG laser) to diagnose a higher density region. The Nike-GIR system is being further extended to measure plasma profiles in the on-going experiment using 135°-separated Nike beam arrays for the cross-beam energy transfer (CBET) studies. We present an overview of the extended Nike-GIR arrangements and a new numerical algorithm to extract self-consistant plasma profiles with the measured quantities. Work supported by DoE/NNSA.

  17. Detonation wave profiles measured in plastic bonded explosives using 1550 nm photon doppler velocimetry (PDV)

    SciTech Connect

    Gustavsen, Richard L; Bartram, Brian D; Sanchez, Nathaniel J

    2009-01-01

    We present detonation wave profiles measured in two TATB based explosives and two HMX based explosives. Profiles were measured at the interface of the explosive and a Lithium-Fluoride (LiF) window using 1550 nm Photon Doppler Velocimetry (PDV). Planar detonations were produced by impacting the explosive with a projectile launched in a gas-gun. The impact state was varied to produce varied distance to detonation, and therefore varied support of the Taylor wave following the Chapman-Jouget (CJ) or sonic state. Profiles from experiments with different support should be the same between the Von-Neumann (VN) spike and CJ state and different thereafter. Comparison of profiles with differing support, therefore, allows us to estimate reaction zone lengths. For the TATB based explosive, a reaction zone length of {approx} 3.9 mm, 500 ns was measured in EDC-35, and a reaction zone length of {approx} 6.3 mm, 800 ns was measured in PBX 9502 pre-cooled to -55 C. The respective VN spike state was 2.25 {+-} 0.05 km/s in EDC-35 and 2.4 {+-} 0.1 km/s in the cooled PBX 9502. We do not believe we have resolved either the VN spike state (> 2.6 km/s) nor the reaction zone length (<< 50 ns) in the HMX based explosives.

  18. Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

    SciTech Connect

    Fischer, W.; Bazilevsky, A.

    2011-08-18

    The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. {bar P}), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g.

    ).

  19. Synergy benefit in temperature, humiditiy and cloud property profiling by integrating ground based and satellite measurements

    NASA Astrophysics Data System (ADS)

    Ebell, K.; Orlandi, E.; Hünerbein, A.; Crewell, S.; Löhnert, U.

    2012-12-01

    Accurate, highly vertically resolved temperature, humidity and cloud property profiles are needed for many applications. They are essential for climate monitoring, a better process understanding and the subsequent improvement of parameterizations in numerical weather prediction and climate models. In order to provide such profiles with a high temporal resolution, multiple wavelength active and passive remote sensing techniques available at ground based observatories, e.g. the Atmospheric Radiation Measruement (ARM) Program and Cloudnet facilities, need to be exploited. In particular, the Integrated Profiling Technique (IPT, Löhnert et al., 2008) has been successfully applied to simultaneously derive profiles of temperature, humidity and liquid water by a Bayesian based retrieval using a combination of ground based microwave radiometer, cloud radar and a priori information. Within the project ICOS (Integrating Cloud Observations from Ground and Space - a Way to Combine Time and Space Information), we develop a flexible IPT, which allows for the combination of a variety of ground based measurements from cloud radar, microwave radiometer (MWR) and IR spectrometer as well as satellite based information from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard of METEOSAT. As ground based observations are mainly sensitive to the lower parts of the troposphere, the satellite measurements provide complementary information and are thus expected to improve the estimates of the thermodynamic and cloud property profiles, i. e. hydrometeor content and effective radius, considerably. In addition to the SEVIRI IR measurements, which are provided with a high repetition time, information from polar orbiting satellites could be included. In paticular, the potential of the Advanced Microwave Sounding Unit-A (AMSU-A) and Microwave Sounding Unit (MHS) in the retrieval is investigated. In order to understand the improvement by integrating the measurements of the above

  20. Harmonized dataset of ozone profiles from satellite limb and occultation measurements

    NASA Astrophysics Data System (ADS)

    Sofieva, V. F.; Rahpoe, N.; Tamminen, J.; Kyrölä, E.; Kalakoski, N.; Weber, M.; Rozanov, A.; von Savigny, C.; Laeng, A.; von Clarmann, T.; Stiller, G.; Lossow, S.; Degenstein, D.; Bourassa, A.; Adams, C.; Roth, C.; Lloyd, N.; Bernath, P.; Hargreaves, R. J.; Urban, J.; Murtagh, D.; Hauchecorne, A.; Dalaudier, F.; van Roozendael, M.; Kalb, N.; Zehner, C.

    2013-12-01

    In this paper, we present a HARMonized dataset of OZone profiles (HARMOZ) based on limb and occultation measurements from Envisat (GOMOS, MIPAS and SCIAMACHY), Odin (OSIRIS, SMR) and SCISAT (ACE-FTS) satellite instruments. These measurements provide high-vertical-resolution ozone profiles covering the altitude range from the upper troposphere up to the mesosphere in years 2001-2012. HARMOZ has been created in the framework of the European Space Agency Climate Change Initiative project. The harmonized dataset consists of original retrieved ozone profiles from each instrument, which are screened for invalid data by the instrument teams. While the original ozone profiles are presented in different units and on different vertical grids, the harmonized dataset is given on a common pressure grid in netCDF (network common data form)-4 format. The pressure grid corresponds to vertical sampling of ~ 1 km below 20 km and 2-3 km above 20 km. The vertical range of the ozone profiles is specific for each instrument, thus all information contained in the original data is preserved. Provided altitude and temperature profiles allow the representation of ozone profiles in number density or mixing ratio on a pressure or altitude vertical grid. Geolocation, uncertainty estimates and vertical resolution are provided for each profile. For each instrument, optional parameters, which are related to the data quality, are also included. For convenience of users, tables of biases between each pair of instruments for each month, as well as bias uncertainties, are provided. These tables characterize the data consistency and can be used in various bias and drift analyses, which are needed, for instance, for combining several datasets to obtain a long-term climate dataset. This user-friendly dataset can be interesting and useful for various analyses and applications, such as data merging, data validation, assimilation and scientific research. The dataset is available at

  1. Improved Ozone Profile Retrievals Using Multispectral Measurements from NASA 'A Train' Satellites

    NASA Astrophysics Data System (ADS)

    Fu, D.; Worden, J.; Livesey, N. J.; Irion, F. W.; Schwartz, M. J.; Bowman, K. W.; Pawson, S.; Wargan, K.

    2013-12-01

    Ozone, a radiatively and chemically important trace gas, plays various roles in different altitude ranges in the atmosphere. In the stratosphere, it absorbs the solar UV radiation from the Sun and protects us from sunburn and skin cancers. In the upper troposphere, ozone acts as greenhouse gas. Ozone in the middle troposphere reacts with many anthropogenic pollutants and cleans up the atmosphere. Near surface ozone is harmful to human health and plant life. Accurate monitoring of ozone vertical distributions is crucial for a better understanding of air quality and climate change. The Ozone Monitoring Instrument (OMI) and the Microwave Limb Sounder (MLS) are both in orbit on the Earth Observing System Aura satellite and are providing ozone concentration profile measurements. MLS observes limb signals from 118 GHz to 2.5 THz, and measures upper tropospheric and stratospheric ozone concentration (among many other species) with a vertical resolution of about 3 km. OMI is a nadir-viewing pushbroom ultraviolet-visible (UV-VIS) imaging spectrograph that measures backscattered radiances covering the 270-500 nm wavelength range. AIRS is a grating spectrometer, on EOS Aqua satellite, that measures the thermal infrared (TIR) radiances emitted by Earth's surface and by gases and particles in the spectral range 650 - 2665 cm-1. We present an approach to combine simultaneously measured UV and TIR radiances together with the retrieved MLS ozone fields, to improve the ozone sounding. This approach has the potential to provide a decadal record of ozone profiles with an improved spatial coverage and vertical resolution from space missions. For evaluating the quality of retrieved profiles, we selected a set of AIRS and OMI measurements, whose ground pixels were collocated with ozonesonde launch sites. The results from combination of these measurements are presented and discussed. The improvements on vertical resolution of tropospheric ozone profiles from the MLS/AIRS/OMI joint

  2. Phase-referenced probe interferometer for biological surface profiling and displacement measurements

    NASA Astrophysics Data System (ADS)

    Fang-Yen, Christopher; Chu, Mark C.; Seung, H. Sebastian; Dasari, Ramachandra R.; Feld, Michael S.

    2007-12-01

    We present a probe-based, phase-referenced low coherence interferometer in which the reference field is provided by a fiber end reflection. A gradient-index microlens focuses light onto a sample and collects reflected light. We use the probe interferometer to measure surface profiles of the compound eye of a housefly (Musca domestica) and measure nanometer-scale vibrations in a test sample.

  3. Does the Effectiveness of Control Measures Depend on the Influenza Pandemic Profile?

    PubMed Central

    Kernéis, Solen; Grais, Rebecca F.; Boëlle, Pierre-Yves; Flahault, Antoine; Vergu, Elisabeta

    2008-01-01

    Background Although strategies to contain influenza pandemics are well studied, the characterization and the implications of different geographical and temporal diffusion patterns of the pandemic have been given less attention. Methodology/Main Findings Using a well-documented metapopulation model incorporating air travel between 52 major world cities, we identified potential influenza pandemic diffusion profiles and examined how the impact of interventions might be affected by this heterogeneity. Clustering methods applied to a set of pandemic simulations, characterized by seven parameters related to the conditions of emergence that were varied following Latin hypercube sampling, were used to identify six pandemic profiles exhibiting different characteristics notably in terms of global burden (from 415 to >160 million of cases) and duration (from 26 to 360 days). A multivariate sensitivity analysis showed that the transmission rate and proportion of susceptibles have a strong impact on the pandemic diffusion. The correlation between interventions and pandemic outcomes were analyzed for two specific profiles: a fast, massive pandemic and a slow building, long-lasting one. In both cases, the date of introduction for five control measures (masks, isolation, prophylactic or therapeutic use of antivirals, vaccination) correlated strongly with pandemic outcomes. Conversely, the coverage and efficacy of these interventions only moderately correlated with pandemic outcomes in the case of a massive pandemic. Pre-pandemic vaccination influenced pandemic outcomes in both profiles, while travel restriction was the only measure without any measurable effect in either. Conclusions Our study highlights: (i) the great heterogeneity in possible profiles of a future influenza pandemic; (ii) the value of being well prepared in every country since a pandemic may have heavy consequences wherever and whenever it starts; (iii) the need to quickly implement control measures and even to

  4. Beam profile measurement and evaluation of far field high energy laser

    NASA Astrophysics Data System (ADS)

    Yang, Pengling; Feng, Guobin; Wang, Zhenbao; Wang, Ping; Wu, Yong; Zhang, Jianmin; Cheng, Shaowu; Feng, Gang; Wang, Fei; Shao, Bibo

    2015-05-01

    The far field beam profile is of significant importance to the analysis of the atmospheric propagation effect and evaluation of the beam control capability, tracking and aiming precision of laser system. In the paper, technology of laser beam measurement such as mid-infrared laser detection at wide temperature range, power density attenuation, photoelectric and calorimetric compound method for laser measurement, synchronous detecting of multi-channel pulsed signal are introduced. A series of instrumented target with detector array are developed for laser beam power density distribution measurement at far field. The power in the bucket, strehl ratio, centroid and jitter of beam can be calculated from the measured results.

  5. Accuracy analysis of the space shuttle solid rocket motor profile measuring device

    NASA Technical Reports Server (NTRS)

    Estler, W. Tyler

    1989-01-01

    The Profile Measuring Device (PMD) was developed at the George C. Marshall Space Flight Center following the loss of the Space Shuttle Challenger. It is a rotating gauge used to measure the absolute diameters of mating features of redesigned Solid Rocket Motor field joints. Diameter tolerance of these features are typically + or - 0.005 inches and it is required that the PMD absolute measurement uncertainty be within this tolerance. In this analysis, the absolute accuracy of these measurements were found to be + or - 0.00375 inches, worst case, with a potential accuracy of + or - 0.0021 inches achievable by improved temperature control.

  6. Electron density profiles obtained from CHAMP GPS radio occultation measurements: Initial results from GFZ

    NASA Astrophysics Data System (ADS)

    Arras, Christina; Schmidt, Torsten; Lee, Woo-Kyoung; Wickert, Jens; Heise, Stefan; Beyerle, Georg; Rothacher, Markus; Jakowski, Norbert

    GPS radio occultation signals received by Low Earth Orbit satellites provide global information about vertical distribution of lower atmospheric parameters (e.g., temperature and water vapour) and electron density in the ionosphere. Since its launch in July 2000 the German geoscience satellite CHAMP has collected about 400,000 occultation measurements. These data form a first and unique long-term dataset of ionospheric profiles, but also of other geophysical variables as temperature, pressure and water vapour in the lower atmosphere. We present initial results of the ionospheric occultation data analyses at GFZ. Vertical electron density profiles from CHAMP are derived using a recently developed software package. To obtain electron densities from calibrated TEC (Total Electron Content) data the so-called onion peeling method is used. The application of this technique allows for the derivation of the electron density profile iteratively starting from the top altitude. The derived profiles are compared with corresponding data processed by UCAR (University Corporation of Atmospheric Research) and DLR Neustrelitz, but also with independent PLP (Planar Langmuir Probe) measurements from CHAMP. These investigations are complemented by case studies comparing the profiles with ground based ionosonde measurements. The high vertical resolution of the derived ionospheric profiles reveals thin vertical ionospheric structures such as sporadic E layers. We investigate the occurrence distribution of these layers in more detail. Sporadic E appears predominantly during summer in the lower ionosphere and has a considerable effect on the propagation of the GPS radio occultation signals. This feature is used to derive information on the altitude and on the intensity of these irregularities.

  7. Understanding Road Usage Patterns in Urban Areas

    PubMed Central

    Wang, Pu; Hunter, Timothy; Bayen, Alexandre M.; Schechtner, Katja; González, Marta C.

    2012-01-01

    In this paper, we combine the most complete record of daily mobility, based on large-scale mobile phone data, with detailed Geographic Information System (GIS) data, uncovering previously hidden patterns in urban road usage. We find that the major usage of each road segment can be traced to its own - surprisingly few - driver sources. Based on this finding we propose a network of road usage by defining a bipartite network framework, demonstrating that in contrast to traditional approaches, which define road importance solely by topological measures, the role of a road segment depends on both: its betweeness and its degree in the road usage network. Moreover, our ability to pinpoint the few driver sources contributing to the major traffic flow allows us to create a strategy that achieves a significant reduction of the travel time across the entire road system, compared to a benchmark approach. PMID:23259045

  8. The Ozone Mapping and Profiler Suite: Extending the BUV Technique to Meet Future Ozone Measurement Requirements

    NASA Astrophysics Data System (ADS)

    Seftor, C. J.; Larsen, J. C.; Remund, Q.; Rodriguez, J. V.; Flynn, L. E.; Hilsenrath, E.

    2003-12-01

    Measurements from the original TOMS and SBUV instruments onboard the Nimbus-7 spacecraft form one of the cornerstones of satellite-based studies of long-term ozone trends. These sensors established the use of the backscattered ultraviolet (BUV) technique, along with calibration techniques based on the measurement of solar flux, to determine and monitor total column and profile ozone amounts on a global, daily basis. They also provided the foundation for the design and development of the Meteor-3, ADEOS, and Earth Probe TOMS sensors and NOAA's successful SBUV/2 series of ozone sensors, whose total column and profile ozone measurements continue through today to extend the set of ozone measurements begun by Nimbus-7. The Ozone Mapping and Profiler Suite (OMPS) is a new generation of hyperspectral BUV sensors that are currently in development for the National Polar-orbiting Operational Environmental Satellite System (NPOESS). These sensors, whose first launch will be onboard the NPOESS Preparatory Project (NPP) satellite in 2006, are designed to continue this long-term data set with better accuracy, precision, and other requirements than any of the total column and profile ozone retrieval systems currently in orbit. In developing the OMPS suite to meet the NPOESS requirements, we systematically analyzed the performance of current BUV systems. We determined that the TOMS sensor and algorithm provided a strong starting point for the development of the OMPS total column ozone retrieval system and we identified areas where design improvements in both would lead to the performance necessary to meet the NPOESS requirements. Since we also determined that an SBUV-type nadir-looking sensor would not meet the NPOESS profile ozone requirements, the OMPS system includes both a nadir profiling sensor to provide measurements that directly link to the SBUV and SBUV/2 heritage dataset and a sensor-algorithm system that uses the limb-scattered BUV/Visible technique pioneered by SOLSE

  9. Concentration profiles from lidar measurements in the presence of multiple scattering: the two-stream approximation

    SciTech Connect

    Ayoubi, I.S.; Nelson, P. )

    1989-10-01

    We consider the problem of obtaining, from monostatic lidar measurements, the concentration profile for a medium of known scattering properties. Invariant imbedding methods are applied to the two-stream approximation to the radiative transfer equation in one dimension, to obtain a nonlinear integrodifferential equation that takes account of multiple scattering events, and whose solution yields the desired profile. A discretization scheme for this equation is presented, along with results from using it to solve two sample problems. The stability of this inversion scheme in the face of noisy signals is also explored.

  10. Continuous Water Vapor Profiles for the Fixed Atmospheric Radiation Measurement Sites

    SciTech Connect

    Jensen, M.; Troyan, D.

    2006-01-09

    The Atmospheric Radiation Measurement (ARM) Program defined a specific metric for the first quarter of Fiscal Year 2006 to complete a continuous time series of the vertical profile of water vapor for selected 30-day periods from each of the fixed ARM sites. In order to accomplish this metric, a new technique devised to incorporate radiosonde data, microwave radiometer data and analysis information from numerical weather forecast models has been developed. The product of this analysis, referred to as the merged sounding value-added product, includes vertical profiles of atmospheric water vapor concentration and several other important thermodynamic state variables at 1-minute time intervals and 266 vertical levels.

  11. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probea)

    NASA Astrophysics Data System (ADS)

    Chen, Y. H.; Yang, X. Y.; Lin, C.; Wang, L.; Xu, M.; Wang, X. G.; Xiao, C. J.

    2014-11-01

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  12. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe.

    PubMed

    Chen, Y H; Yang, X Y; Lin, C; Wang, L; Xu, M; Wang, X G; Xiao, C J

    2014-11-01

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  13. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe

    SciTech Connect

    Chen, Y. H.; Yang, X. Y.; Lin, C. E-mail: cjxiao@pku.edu.cn; Wang, X. G.; Xiao, C. J. E-mail: cjxiao@pku.edu.cn; Wang, L.; Xu, M.

    2014-11-15

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  14. The substance use risk profile scale: a scale measuring traits linked to reinforcement-specific substance use profiles.

    SciTech Connect

    Woicik, P.A.; Stewart, S.H.; Pihl, R.O.; Conrod, P.J.

    2009-12-01

    The Substance Use Risk Profile Scale (SURPS) is based on a model of personality risk for substance abuse in which four personality dimensions (hopelessness, anxiety sensitivity, impulsivity, and sensation seeking) are hypothesized to differentially relate to specific patterns of substance use. The current series of studies is a preliminary exploration of the psychometric properties of the SURPS in two populations (undergraduate and high school students). In study 1, an analysis of the internal structure of two versions of the SURPS shows that the abbreviated version best reflects the 4-factor structure. Concurrent, discriminant, and incremental validity of the SURPS is supported by convergent/divergent relationships between the SURPS subscales and other theoretically relevant personality and drug use criterion measures. In Study 2, the factorial structure of the SURPS is confirmed and evidence is provided for its test-retest reliability and validity with respect to measuring personality vulnerability to reinforcement-specific substance use patterns. In Study 3, the SURPS was administered in a more youthful population to test its sensitivity in identifying younger problematic drinkers. The results from the current series of studies demonstrate support for the reliability and construct validity of the SURPS, and suggest that four personality dimensions may be linked to substance-related behavior through different reinforcement processes. This brief assessment tool may have important implications for clinicians and future research.

  15. Experimental measurements of the detonation wave profile in a TATB based explosive

    NASA Astrophysics Data System (ADS)

    Bouyer, V.; Doucet, M.; Decaris, L.

    We report results of the experimental measurements of the detonation wave profile of the TATB based plastic bonded explosive T2 (97 w. % of TATB) using VISAR and Heterodyne Velocimetry (HV - same as Photon Doppler Velocimetry). The experiment consists in initiating a detonation wave in a 15 mm diameter cylinder of explosive using an explosive wire detonator and an explosive booster. In order to obtain the particle velocity history in the reaction zone, we measure particle velocity at the interaction of the detonation front with an aluminized window or the free surface velocity of a metallic foil. Lithium Fluoride (LIF), PMMA and steel have been tested. Several shots have been performed for different lengths of explosive. We compare the VISAR and HV measurements. With LIF and steel, VISAR and HV diagnostics give very similar profiles. The ZND profile obtained on LIF is resolved with both techniques. With PMMA, HV gives a more accurate profile than VISAR in the reaction zone. There is no evidence of the influence of the explosive cylinder length.

  16. A high-resolution beam profile measuring system for high-current ion implanters

    NASA Astrophysics Data System (ADS)

    Fujishita, N.; Noguchi, K.; Sasaki, S.; Yamamoto, H.

    1991-04-01

    A high-resolution beam profile measuring system (BPM) has been developed to analyze the correlation between charging damage and the ion beam profile for high-current ion implanters. With the increase of the ion beam current, insulators such as thin oxide layers of VLSI devices are subject to charging damage during ion implantation. To obtain accurate information on the local current density of the ion beam, 125 Faraday cups are placed in the BPM. This system has two measuring modes. One is a topographic mode that can detect the ion beam current density of 12500 sampling points in 30 s. A high-resolution contour map of the current density distribution is displayed on a CRT. The other is a real-time mode in which the current density distribution (125 sampling points) of the ion beam can be monitored every half second on the CRT. In this mode, fine adjustment of the ion beam profile is easily possible by visual control. The charging damage of insulating layers in the TEG (test element group) to the beam profile was investigated using this newly developed BPM. It has been proven that the damage probability increases rapidly above some threshold level of the beam current density. It is confirmed that for high-current implantation a uniform current density distribution of the ion beam is very effective to prevent charging damage. It is concluded that this measuring system is valuable not only for quick analysis of damage phenomena, but also for evaluating machine performance.

  17. Method for measuring radial impurity emission profiles using correlations of line integrated signals

    NASA Astrophysics Data System (ADS)

    Kuldkepp, M.; Brunsell, P. R.; Drake, J.; Menmuir, S.; Rachlew, E.

    2006-04-01

    A method of determining radial impurity emission profiles is outlined. The method uses correlations between line integrated signals and is based on the assumption of cylindrically symmetric fluctuations. Measurements at the reversed field pinch EXTRAP T2R show that emission from impurities expected to be close to the edge is clearly different in raw as well as analyzed data to impurities expected to be more central. Best fitting of experimental data to simulated correlation coefficients yields emission profiles that are remarkably close to emission profiles determined using more conventional techniques. The radial extension of the fluctuations is small enough for the method to be used and bandpass filtered signals indicate that fluctuations below 10kHz are cylindrically symmetric. The novel method is not sensitive to vessel window attenuation or wall reflections and can therefore complement the standard methods in the impurity emission reconstruction procedure.

  18. Atmospheric profiles at the southern Pierre Auger Observatory and their relevance to air shower measurement

    SciTech Connect

    Keilhauer, B.; Bluemer, J.; Engel, R.; Gora, D.; Homola, P.; Klages, H.; Pekala, J.; Risse, M.; Unger, M.; Wilczynska, B.; Wilczynski, H.

    2005-07-01

    The dependence of atmospheric conditions on altitude and time have to be known at the site of an air shower experiment for accurate reconstruction of extensive air showers and their simulations. The height-profile of atmospheric depth is of particular interest as it enters directly into the reconstruction of longitudinal shower development and of the primary energy and mass of cosmic rays. For the southern part of the Auger Observatory, the atmosphere has been investigated in a number of campaigns with meteorological radio soundings and with continuous measurements of ground-based weather stations. Focusing on atmospheric depth and temperature profiles, temporal variations are described and monthly profiles are developed. Uncertainties of the monthly atmospheres that are currently applied in the Auger reconstruction are discussed.

  19. Differential absorption lidar technique for measurement of the atmospheric pressure profile

    NASA Technical Reports Server (NTRS)

    Korb, C. L.; Weng, C. Y.

    1983-01-01

    A new two-wavelength lidar technique for remotely measuring the pressure profile using the trough absorption region between two strong lines in the oxygen A band is described. The theory of integrated vertical path, differential ranging, and horizontal-path pressure measurements is given, with methods to desensitize and correct for temperature effects. The properties of absorption troughs are described and shown to reduce errors due to laser frequency jitter by up to two orders of magnitude. A general analysis, including laser bandwidth effects, demonstrates that pressure measurements with an integrated-vertical-path technique are typically fifty times more accurate than with a differential ranging technique. Simulations show 0.1-0.3 percent accuracy for ground and Shuttle-based pressure-profile and surface-pressure experiments.

  20. Optical measurement of static temperature and hydroxyl radical profiles in a hydrogen-fueled supersonic combustor

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1974-01-01

    Profiles of static temperature and hydroxyl radical concentration were measured in a two-dimensional supersonic combustor test section 22.8 cm downstream of hydrogen injection. A high-pressure gas generator supplied vitiated air to the test section at Mach 2.44, atmospheric pressure, and a total temperature of about 2240 K. Room-temperature hydrogen was injected through a 0.40-cm step slot at Mach 1 and matched pressure. The measurements utilized a noninterfering spectral line absorption technique in which narrow ultraviolet emission lines of the hydroxyl electronic transition are absorbed by the broader absorption lines in the combustion gas. Comparison of the measured temperature profiles with theoretical calculations showed good agreement.

  1. Comparison of ozone profiles obtained with NIES DIAL and SAGE II measurements

    NASA Technical Reports Server (NTRS)

    Nakane, Hideaki; Sasano, Yasuhiro; Hayashida-Amano, Sachiko; Sugimoto, Nobuo; Matsui, Ichiro; Minato, Atsushi; Mccormick, M. P.

    1993-01-01

    Ozone profiles obtained with the Differential Absorption Lidar (DIAL) system at the National Institute for Environmental Studies (NIES) (Tsukuba, Japan) were compared with data provided by the satellite sensor SAGE II. The SAGE II data were selected based on criteria of spatial and temporal differences between the DIAL and the SAGE II measurements: five degrees in latitude and 15 degrees in longitude, within a latitudinal band from 31 deg to 41 deg N, and within one, three and five days after or before the DIAL measurements. Results show very good agreement for the individual and the zonal-mean profiles. The average mean difference between the DIAL and the SAGE II measurements over the altitudes 15-50 km was about 10 percent.

  2. Watershed Scale Shear Stress From Tethersonde Wind Profile Measurements Under Near Neutral and Unstable Atmospheric Stability

    NASA Astrophysics Data System (ADS)

    Parlange, M. B.; Katul, G. G.

    1995-04-01

    Mean wind speed profiles were measured in the atmospheric surface layer, using a tethersonde system, above the Ojai Valley Watershed in southern California. The valley is mainly planted with mature avocado and orange trees. The surface shear stress and latent and sensible heat fluxes were measured above the trees which are up to 9 m in height. Near-neutral wind speed profile measurements allowed the determination of the watershed surface roughness (z0 = 1.4 m) and the momentum displacement height (d0 = 7.0 m). The wind speed measurements obtained under unstable atmospheric stability were analyzed using Monin-Obukhov similarity theory. New stability correction functions proposed based on theory and experiments of Kader-Yaglom as well as the now classic Businger-Dyer type functions were tested. The watershed shear stress values calculated using the surface layer wind speed profiles with the new Monin-Obukhov stability functions were found to be improved in comparison with the values obtained with the Businger-Dyer functions under strongly unstable stability conditions. The Monin-Obukhov model with the Businger-Dyer stability correction function underpredicted the momentum flux by 25% under strongly unstable stability conditions, while the new Kader-Yaglom formulation compared well on average (R2 = 0.77) with the surface eddy correlation measurements for all atmospheric stability conditions. The unstable 100-m drag coefficient was found to be u*2/V1002 = 0.0182.

  3. Vertical Profiles of Aerosol Optical Properties Over Central Illinois and Comparison with Surface and Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Sheridan P. J.; Andrews, E.; Ogren, J A.; Tackett, J. L.; Winker, D. M.

    2012-01-01

    Between June 2006 and September 2009, an instrumented light aircraft measured over 400 vertical profiles of aerosol and trace gas properties over eastern and central Illinois. The primary objectives of this program were to (1) measure the in situ aerosol properties and determine their vertical and temporal variability and (2) relate these aircraft measurements to concurrent surface and satellite measurements. Underflights of the CALIPSO satellite show reasonable agreement in a majority of retrieved profiles between aircraft-measured extinction at 532 nm (adjusted to ambient relative humidity) and CALIPSO-retrieved extinction, and suggest that routine aircraft profiling programs can be used to better understand and validate satellite retrieval algorithms. CALIPSO tended to overestimate the aerosol extinction at this location in some boundary layer flight segments when scattered or broken clouds were present, which could be related to problems with CALIPSO cloud screening methods. The in situ aircraft-collected aerosol data suggest extinction thresholds for the likelihood of aerosol layers being detected by the CALIOP lidar. These statistical data offer guidance as to the likelihood of CALIPSO's ability to retrieve aerosol extinction at various locations around the globe.

  4. Prediction of Erosion from Forest Road Networks

    NASA Astrophysics Data System (ADS)

    Black, Thomas; Nelson, Nathan; Cissel, Richard; Luce, Charles

    2013-04-01

    Roads are widely acknowledged as a major source of sediment to headwater streams in forests. While a number of tools have evolved to evaluate individual road segments, many questions exist about the interaction of road networks and stream networks at larger scales. A number of ad-hoc hypotheses have emerged to use GIS layers to roughly estimate road contributions to sediment for watersheds, but validation of such models is difficult without detailed observations of as-built condition and performance of forest road drainage systems. We present analysis of detailed measurements from five watershed scale road inventory projects using the Geomorphic Road Analysis and Inventory Package (GRAIP, http://www.fs.fed.us/GRAIP/). The common outcome of all analyses is that a small fraction of the road network and their associated drainage is responsible for the great majority of fine sediment inputs. Stream crossings not only represented a dominant location of sediment delivery, but nearly a quarter had a high risk of becoming plugged and overtopped or a potential for flow diversion down the road after plugging. In some locations, gully risks showed threshold-like behavior relative to a combination of contributing road segment length and the slope of the discharge hillslope. Using insights gained from the detailed inventories, we developed a method to subsample segments in a road network to infer sediment inputs to the stream network. Validation of the approach shows good agreement with observations, with proportional errors becoming small with increasing watershed size.

  5. Long-Term Correlations and Multifractality of Traffic Flow Measured by GIS for Congested and Free-Flow Roads

    NASA Astrophysics Data System (ADS)

    di, Baofeng; Shi, Kai; Zhang, Kaishan; Svirchev, Laurence; Hu, Xiaoxi

    2016-02-01

    In this paper, a GIS-based method was developed to extract the real-time traffic information (RTTI) from the Google Maps system for city roads. The method can be used to quantify both congested and free-flow traffic conditions. The roadway length was defined as congested length (CL) and free-flow length (FFL). Chengdu, the capital of Sichuan Province in the southwest of China, was chosen as a case study site. The RTTI data were extracted from the Google real-time maps in May 12-17, 2013 and were used to derive the CL and FFL for the study areas. The Multifractal Detrended Fluctuation Analysis (MFDFA) was used to characterize the long-term correlations of CL and FFL time series and their corresponding multifractal properties. Analysis showed that CL and FFL had demonstrated time nonlinearity and long-term correlations and both characteristics differed significantly. A shuffling procedure and a phase randomization procedure were further integrated with multifractal detrending moving average (MFDMA) to identify the major sources of multifractality of these two time series. The results showed that a multifractal process analysis could be used to characterize complex traffic data. Traffic data collected and methods developed in this paper will help better understand the complex traffic systems.

  6. Development of internal magnetic probe for current density profile measurement in Versatile Experiment Spherical Torus

    NASA Astrophysics Data System (ADS)

    Yang, J.; Lee, J. W.; Jung, B. K.; Chung, K. J.; Hwang, Y. S.

    2014-11-01

    An internal magnetic probe using Hall sensors to measure a current density profile directly with perturbation of less than 10% to the plasma current is successfully operated for the first time in Versatile Experiment Spherical Torus (VEST). An appropriate Hall sensor is chosen to produce sufficient signals for VEST magnetic field while maintaining the small size of 10 mm in outer diameter. Temperature around the Hall sensor in a typical VEST plasma is regulated by blown air of 2 bars. First measurement of 60 kA VEST ohmic discharge shows a reasonable agreement with the total plasma current measured by Rogowski coil in VEST.

  7. Development of the methodology of exhaust emissions measurement under RDE (Real Driving Emissions) conditions for non-road mobile machinery (NRMM) vehicles

    NASA Astrophysics Data System (ADS)

    Merkisz, J.; Lijewski, P.; Fuc, P.; Siedlecki, M.; Ziolkowski, A.

    2016-09-01

    The paper analyzes the exhaust emissions from farm vehicles based on research performed under field conditions (RDE) according to the NTE procedure. This analysis has shown that it is hard to meet the NTE requirements under field conditions (engine operation in the NTE zone for at least 30 seconds). Due to a very high variability of the engine conditions, the share of a valid number of NTE windows in the field test is small throughout the entire test. For this reason, a modification of the measurement and exhaust emissions calculation methodology has been proposed for farm vehicles of the NRMM group. A test has been developed composed of the following phases: trip to the operation site (paved roads) and field operations (including u-turns and maneuvering). The range of the operation time share in individual test phases has been determined. A change in the method of calculating the real exhaust emissions has also been implemented in relation to the NTE procedure.

  8. Combining measurements and modelling to quantify the contribution of atmospheric fallout, local industry and road traffic to PAH stocks in contrasting catchments.

    PubMed

    Gateuille, David; Evrard, Olivier; Lefevre, Irène; Moreau-Guigon, Elodie; Alliot, Fabrice; Chevreuil, Marc; Mouchel, Jean-Marie

    2014-06-01

    Various sources supply PAHs that accumulate in soils. The methodology we developed provided an evaluation of the contribution of local sources (road traffic, local industries) versus remote sources (long range atmospheric transport, fallout and gaseous exchanges) to PAH stocks in two contrasting subcatchments (46-614 km²) of the Seine River basin (France). Soil samples (n = 336) were analysed to investigate the spatial pattern of soil contamination across the catchments and an original combination with radionuclide measurements provided new insights into the evolution of the contamination with depth. Relationships between PAH concentrations and the distance to the potential sources were modelled. Despite both subcatchments are mainly rural, roadside areas appeared to concentrate 20% of the contamination inside the catchment while a local industry was found to be responsible for up to 30% of the stocks. Those results have important implications for understanding and controlling PAH contamination in rural areas of early-industrialized regions. PMID:24662001

  9. Analysis of actinic flux profiles measured from an ozone sonde balloon

    NASA Astrophysics Data System (ADS)

    Wang, P.; Allaart, M.; Knap, W. H.; Stammes, P.

    2014-12-01

    A green light sensor has been developed at KNMI to measure actinic flux profiles using an ozone sonde balloon. In total, 63 launches with ascending and descending profiles were performed between 2006 and 2010. The measured uncalibrated actinic flux profiles are analyzed using the Doubling Adding KNMI (DAK) radiative transfer model. Values of the cloud optical thickness (COT) along the flight track were taken from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) Cloud Physical Properties (CPP) product. The impact of clouds on the actinic flux profile is evaluated on the basis of the cloud modification factor (CMF) at the cloud top and cloud base, which is the ratio between the actinic fluxes for cloudy and clear-sky scenes. The impact of clouds on the actinic flux is clearly detected: the largest enhancement occurs at the cloud top due to multiple scattering. The actinic flux decreases almost linearly from cloud top to cloud base. Above the cloud top the actinic flux also increases compared to clear-sky scenes. We find that clouds can increase the actinic flux to 2.3 times of the clear-sky value at cloud top and decrease it to about 0.05 at cloud base. The relationship between CMF and COT agrees well with DAK simulations, except for a few outliers. Good agreement is found between the DAK simulated actinic flux profiles and the observations for single layer clouds in fully overcast scenes. The instrument is suitable for operational balloon measurements because of its simplicity and low cost. It is worth to further develop the instrument and launch it together with atmospheric chemistry composition sensors.

  10. Three-dimensional profile measurement based on light-section method

    NASA Astrophysics Data System (ADS)

    Wang, Shicheng; Zhao, Quanke; Wang, Zeyong; Zhou, Xiaohong

    2010-08-01

    This paper describes a computer vision method for reconstruction of three-dimensional object which is capable of reconstructing the profile of the object real time and achieving high accuracy. The approach makes use of the light-section projecting a line-laser beam on the surface of an object. This work is distinguished by three key contributions. The first is the introduction of the light-section method and laser triangulation method. The space coordinates of points in the bright stripe which are considered as the first bright stripe outlining the measured object can be figured out by way of the laser triangulation method. The second contribution is algorithms of coordinate restoration, involved camera calibration and calibration of the central axis of turntable, which restores the space coordinates of the original points in the original bright stripe from that of being considered as the first bright stripe. The third is the profile reconstruction method for plotting the profile of the measured object using the OpenGL. In this paper, an experiment on a small disposal paper cup has been carried out and the three-dimensional profile of the paper cup has been obtained. The results meet the requirement of high accuracy and simplicity of computation.

  11. Estimation of topside electron density profile using on-orbit measured GPS and electron density data.

    NASA Astrophysics Data System (ADS)

    Lee, J.

    2015-12-01

    The topside ionophere have lacks of information about plasma, but it is important for human beings and scientific applicaiton. We establish an estimation method for electron density profile using Langmuir Probe and GPS data of CHAMP satellite and have comparision the method results with other satellites measurements. In order to develop the model, hydrostatic mapping function, vertical scale height, and vertical TEC(Total Electron Contents) are used for calculations. The electron density and GPS data with hydrostatic mapping function give the vertical TEC and after some algebra using exponential model of density profile give the vertical scale height of ionosphere. The scale height have about 10^2~10^3 km order of magnitude so it can be used exponential model again since the altitude of CHAMP. Therefore, apply the scale height to exponoential model we can get the topside electron density profile. The result of the density profile model can be compared with other satellite data as STSAT-1, ROCSAT, DMSP which is measured the electron density in similar Local Time, Latitude, Longitude but above the CHAMP. This comparison shows the method is accecptable and it can be applied to other reseach for topside ionosphere.

  12. Heavy ion beam probe measurements of radial potential profiles in the modified Penning discharge

    NASA Technical Reports Server (NTRS)

    Kambic, G. X.

    1974-01-01

    A heavy ion beam probe was used to examine the radial potential profile of a plasma in the modified Penning discharge. The plasma has strong (approximately kV) electrostatic potentials near the anode ring which can be a large fraction of the injected ion beam energy. A primary (singly ionized) thallium ion beam is injected through the plasma in the midplane of a double Penning anode ring. After passage through the plasma, primary and secondary (doubly ionized) ions are detected with either a set of flat probes or an electrostatic energy analyzer. A calculation of the primary orbit through the plasma is performed to obtain an approximation to the measured primary beam trajectory. As the real radial potential profile is unknown, an adjustable model is used in the computer program. The adjustable potential profile is varied until the best agreement between measured and calculated trajectories is obtained. Secondary orbits are also predicted using the best fitting adjustable profile. The calculations indicate that secondary beams originating at more than one point in the plasma can be simultaneously observed at the electrostatic analyzer with certain primary beam initial conditions.

  13. Vertical Tracer Concentration Profiles Measured During the Joint Urban 2003 Dispersion Study

    SciTech Connect

    Flaherty, Julia E.; Lamb, Brian K.; Allwine, K Jerry; Allwine, Eugene J.

    2007-12-01

    An atmospheric tracer dispersion study known as Joint Urban 2003 was conducted in Oklahoma City, Oklahoma during the summer of 2003. As part of this field program, vertical concentration profiles were measured at approximately 1 km from downtown tracer gas release locations. These profiles indicated that the urban landscape was very effective in mixing the plume vertically. The height of the plume centerline (as determined by the maximum concentration over the depth of the measurements) for any specific 30 min period varied over the 65 m measurement range. Most of the variations in tracer concentration observed in the profile time series were related to changes in wind direction as opposed to changes in turbulence. As a simple analysis tool for emergency response, maximum normalized concentration curves were developed with 5-minute averaged measurements. These curves give the maximum concentration (normalized by the release rate) that would be observed as a function of downwind distance in an urban area. The 5-min data resulted in greater concentrations than predicted with a simple Gaussian plume model. However, the curve compared well with results from a computational fluid dynamics simulation. This dispersion dataset is a valuable asset not only for refining air quality models, but also for developing new tools for emergency response personnel in the event of a toxic release.

  14. Stratospheric methane profiles from SCIAMACHY solar occultation measurements derived with onion peeling DOAS

    NASA Astrophysics Data System (ADS)

    Noël, S.; Bramstedt, K.; Rozanov, A.; Bovensmann, H.; Burrows, J. P.

    2011-11-01

    Stratospheric methane (CH4) profiles have been derived from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on ENVISAT with an updated version of the Onion Peeling DOAS (ONPD) method. The SCIAMACHY solar occultation measurements cover the latitudinal range between about 50° N and 70° N. Currently, reasonable results are obtained between 20 and 40 km altitude. Comparisons with correlative ACE-FTS measurements show an average agreement within the expected accuracy of the ACE-FTS data of about 10%. To demonstrate the capability of SCIAMACHY solar occultation measurements in the context of greenhouse gas monitoring, time series of stratospheric CH4 profiles covering the period from 2003 to 2010 have been generated. The SCIAMACHY CH4 profile solar occultation temporal series shows a strong seasonal cycle. This is attributed to the variations in both time and space of the retrieved data set. At lower altitudes, the observed temporal variations are explained by variations of the tropopause height. The temporal data set is also impacted by variations of the size and duration of the polar vortex in the northern hemisphere. The data set provides unique information about CH4 changes in the stratosphere at mid to high latitudes.

  15. Stratospheric methane profiles from SCIAMACHY solar occultation measurements derived with onion peeling DOAS

    NASA Astrophysics Data System (ADS)

    Noël, S.; Bramstedt, K.; Rozanov, A.; Bovensmann, H.; Burrows, J. P.

    2011-07-01

    Stratospheric methane (CH4) profiles have been derived from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on ENVISAT with an updated version of the Onion Peeling DOAS (ONPD) method. The SCIAMACHY solar occultation measurements cover the latitudinal range between about 50° N and 70° N. Currently, reasonable results are obtained between 20 and 40 km altitude. Comparisons with correlative ACE-FTS measurements show an average agreement within the expected accuracy of the ACE-FTS data of about 10 %. To demonstrate the capability of SCIAMACHY solar occultation measurements in the context of greenhouse gas monitoring, time series of stratospheric CH4 profiles covering the period from 2003 to 2010 have been generated. The SCIAMACHY CH4 profile solar occultation temporal series shows a strong seasonal cycle. This is attributed to the variations in both time and space of the retrieved data set. At lower altitudes, the observed temporal variations are explained by variations of the tropopause height. The temporal data set is also impacted by variations of the size and duration of the polar vortex in the northern hemisphere. The data set provides unique information about CH4 changes in the stratosphere at mid to high latitudes.

  16. Altitude profile of aerosols on Mars from measurements of its thermal radiation on limb

    NASA Technical Reports Server (NTRS)

    Moroz, V. I.; Titov, D. V.; Gektin, Yu. M.; Naraeva, M. K.; Selivanov, A. S.

    1993-01-01

    Measurements of the thermal (range 7 - 13 micrometers) radiation of Mars with the high space resolution (approximately 2 km) were made by the TERMOSKAN experiment of the Phobos mission. Some of the results were published earlier but only the surface radiation was analyzed in detail. However some part of these measurements was made near the limb of the planet. The atmosphere gives an important input here in the planetary thermal radiation. Beyond the limb the atmosphere is the only source. The task of this work is to estimate some characteristics of the atmosphere using brightness profiles of the thermal radiation near the limb. An appropriate model of the temperature profile T(h) is necessary for such an analysis. A set of T(h) models (nominal, maximal and minimal) was defined using various sources including MARSGRAM, Viking-1 lander data, its theoretical considerations and boundary layer models. On the next step the possible input of the atmospheric gaseous emissions (wing of CO2 15 micrometer band) was estimated. It was found that even for the maximal T(h) this input is no more than a few percents of the measured radiation beyond the limb. Consequently the aerosols are responsible for almost all measured emission. The analysis of the observed profile showed that these aerosols have two components: (1) exponential with the scale height about 10 km and (2) some layered structure (two layers with maxima about 23 and 33 km consisted probably of ice).

  17. Temperature Profile Measurements in a Newly Constructed 30-Stage 5 cm Centrifugal Contactor pilot Plant

    SciTech Connect

    Troy G. Garn; Dave H. Meikrantz; Mitchell R. Greenhalgh; Jack D. Law

    2008-09-01

    An annular centrifugal contactor pilot plant incorporating 30 stages of commercial 5 cm CINC V-02 units has been built and operated at INL during the past year. The pilot plant includes an automated process control and data acquisitioning system. The primary purpose of the pilot plant is to evaluate the performance of a large number of inter-connected centrifugal contactors and obtain temperature profile measurements within a 30-stage cascade. Additional solvent extraction flowsheet testing using stable surrogates is also being considered. Preliminary hydraulic testing was conducted with all 30 contactors interconnected for continuous counter-current flow. Hydraulic performance and system operational tests were conducted successfully but with higher single-stage rotor speeds found necessary to maintain steady interstage flow at flowrates of 1 L/min and higher. Initial temperature profile measurements were also completed in this configuration studying the performance during single aqueous and two-phase counter-current flow at ambient and elevated inlet solution temperatures. Temperature profile testing of two discreet sections of the cascade required additional feed and discharge connections. Lamp oil, a commercially available alkane mixture of C14 to C18 chains, and tap water adjusted to pH 2 were the solution feeds for all the testing described in this report. Numerous temperature profiles were completed using a newly constructed 30-stage centrifugal contactor pilot plant. The automated process control and data acquisition system worked very well throughout testing. Temperature data profiles for an array of total flowrates (FT) and contactor rpm values for both single-phase and two-phase systems have been collected with selected profiles and comparisons reported. Total flowrates (FT) ranged from 0.5-1.4 L/min with rotor speeds from 3500-4000 rpm. Solution inlet temperatures ranging from ambient up to 50° C were tested. Ambient temperature testing shows that a

  18. Airborne Lidar measurements of the atmospheric pressure profile with tunable Alexandrite lasers

    NASA Technical Reports Server (NTRS)

    Korb, C. L.; Schwemmer, G. K.; Dombrowski, M.; Milrod, J.; Walden, H.

    1986-01-01

    The first remote measurements of the atmospheric pressure profile made from an airborne platform are described. The measurements utilize a differential absorption lidar and tunable solid state Alexandrite lasers. The pressure measurement technique uses a high resolution oxygen A band where the absorption is highly pressure sensitive due to collision broadening. Absorption troughs and regions of minimum absorption were used between pairs of stongly absorption lines for these measurements. The trough technique allows the measurement to be greatly desensitized to the effects of laser frequency instabilities. The lidar system was set up to measure pressure with the on-line laser tuned to the absorption trough at 13147.3/cm and with the reference laser tuned to a nonabsorbing frequency near 13170.0/cm. The lidar signal returns were sampled with a 200 range gate (30 vertical resoltion) and averaged over 100 shots.

  19. Airborne and ground based lidar measurements of the atmospheric pressure profile

    NASA Technical Reports Server (NTRS)

    Korb, C. Laurence; Schwemmer, Geary K.; Dombrowski, Mark; Weng, Chi Y.

    1989-01-01

    The first high accuracy remote measurements of the atmospheric pressure profile have been made. The measurements were made with a differential absorption lidar system that utilizes tunable alexandrite lasers. The absorption in the trough between two lines in the oxygen A-band near 760 nm was used for probing the atmosphere. Measurements of the two-dimensional structure of the pressure field were made in the troposphere from an aircraft looking down. Also, measurements of the one-dimensional structure were made from the ground looking up. Typical pressure accuracies for the aircraft measurements were 1.5-2 mbar with a 30-m vertical resolution and a 100-shot average (20 s), which corresponds to a 2-km horizontal resolution. Typical accuracies for the upward viewing ground based measurements were 2.0 mbar for a 30-m resolution and a 100-shot average.

  20. 1985 Voyager 2 Radio Ranging Measurements of Coronal Density: Asymmetry in the Radial Profiles Explained

    NASA Technical Reports Server (NTRS)

    Woo, Richard

    1996-01-01

    An asymmetry in the radial variation of electron density above the cast and west limbs of the Sun was inferred from centimeter wavelength ranging measurements conducted by Voyager 2 during its 1985 solar conjunction. The Voyager 2 ranging measurements, which took place in the heliocentric distance range of 7-40 solar radius, have been compared with the white-light coronagraph measurements of the underlying corona collected by the Mark 3 K-coronameter located at the Mauna Loa Solar Observatory. It is shown that the disparity in radial profiles is not real but is instead caused by longitudinal variations stemming from the probing of significantly different source regions its revealed in the white-light measurements. These results improve our understanding of the probing abilities of ranging measurements and their relationship to white-light measurements. They reinforce the notion that the high-precision and high-sensitivity features of ranging measurements are more fully exploited in the investigation of density variations across the ubiquitous low-contrast raylike structures that permit the corona, rather than in determining radial density profiles.

  1. CT radiation profile width measurement using CR imaging plate raw data.

    PubMed

    Bjarnason, Thorarin Albert; Yang, Chang-Ying Joseph

    2015-01-01

    This technical note demonstrates computed tomography (CT) radiation profile measurement using computed radiography (CR) imaging plate raw data showing it is possible to perform the CT collimation width measurement using a single scan without saturating the imaging plate. Previously described methods require careful adjustments to the CR reader settings in order to avoid signal clipping in the CR processed image. CT radiation profile measurements were taken as part of routine quality control on 14 CT scanners from four vendors. CR cassettes were placed on the CT scanner bed, raised to isocenter, and leveled. Axial scans were taken at all available collimations, advancing the cassette for each scan. The CR plates were processed and raw CR data were analyzed using MATLAB scripts to measure collimation widths. The raw data approach was compared with previously established methodology. The quality control analysis scripts are released as open source using creative commons licensing. A log-linear relationship was found between raw pixel value and air kerma, and raw data collimation width measurements were in agreement with CR-processed, bit-reduced data, using previously described methodology. The raw data approach, with intrinsically wider dynamic range, allows improved measurement flexibility and precision. As a result, we demonstrate a methodology for CT collimation width measurements using a single CT scan and without the need for CR scanning parameter adjustments which is more convenient for routine quality control work. PMID:26699559

  2. Profile analysis of ventricle specimen based on a new phase measuring method

    NASA Astrophysics Data System (ADS)

    Cao, Yiping; Su, Xianyu; Chen, Wenjing; Xiang, Liqun; Zhang, Qichan; Liu, Yuankun

    2009-08-01

    The size and shape of ventricle are very important to analyze and diagnose pathology of human heart. So it is very necessary to measure the profile of ventricle. It is very difficult to measure the ventricle by vivisectional method for its unique function of heart, so the ventricle specimen is adopted to be measured. Three-dimensional (3D) automatic measurement methods are widely used in many fields. In Biology and Medicine society, it can be applicable for surgery, orthopedics, viscera disease analysis and diagnosis etc. Here a new method to measure the 3D surface of ventricle specimen is proposed. Although the traditional 3D measuing method with equal or stated phase-shifting step length possess excellent accuracy, they are much dependent on the consistency of these phase-shifting step lengths. In fact, this condition is very difficult to guarantee. which may lead to the incorrect wrapped phase and incorrect phase unwrapping in some regions, even the reconstructed object may be misshapen or anamorphic. In the proposed method, a novel improved three undecided step lengths phase-shifting algorithm with three unequal phase-shifting steps has been presented detailed and is applied to measure the profile of ventricle sucssesfully. Experiments show that the improved algorithm can not only effectively improve the measuring accuracy, but also branch out its application.

  3. Measurement of the Beam Longitudinal Profile in a Storage Ring by Non-Linear Laser Mixing

    NASA Astrophysics Data System (ADS)

    Beche, J.-F.; Byrd, J.; De Santis, S.; Denes, P.; Placidi, M.; Turner, W.; Zolotorev, M.

    2004-11-01

    We report on the development of a new technique for the measurement of the longitudinal beam profile in storage rings. This technique, which has been successfully demonstrated at the Advanced Light Source, mixes the synchrotron radiation with the light from a mode-locked solid-state laser oscillator in a non-linear crystal. The up-converted radiation is then detected with a photomultiplier and processed to extract, store, and display the required information. The available choices of laser repetition frequency, pulse width, and phase modulation give a wide range of options for matching the bunch configuration of a particular storage ring. Besides the dynamic measurement of the longitudinal profile of each bunch, the instrument can monitor the evolution of the bunch tails, the presence of un trapped particles, and their diffusion into nominally empty RF buckets ("ghost bunches").

  4. PNNL/Euratom glass fiber optic, spent fuel neutron profile measurement system

    SciTech Connect

    SM Bowyer; JE Smart

    2000-03-03

    The glass fiber optic spent fuel neutron profile measurement system is designed to measure the neutron profile of a Castor with high reproducibility and to distinguish spent fuel Castor contents from vitrified waste Castor contents. The basic principle of the detector is that the glass fibers detect thermal neutrons. The glass is loaded with lithium enriched in Li-6, which has a high thermal neutron cross-section. A neutron is captured by the Li-6 and a He-4 and H-3 are created. Because the glass also contains Cerium in a 3{sup +} ionization state, the excitation caused by the movement of the He-4 and H-3 results in the emission of light from the cerium atoms. This light then travels to the ends of the fiber where it is detected by photon sensitive devices (e.g., photo-multiplier tubes).

  5. Measurement of the beam longitudinal profile in a storage ring bynon-linear laser mixing

    SciTech Connect

    Beche, J.-F.; Byrd, J.; De Santis, S.; Denes, P.; Placidi, M.; Turner, W.; Zolotorev, M.

    2004-05-03

    We report on the development of a new technique for the measurement of the longitudinal beam profile in storage rings. This technique, which has been successfully demonstrated at the Advanced Light Source, mixes the synchrotron radiation with the light from a mode-locked solid state laser oscillator in a non-linear crystal. The up-converted radiation is then detected with a photomultiplier and processed to extract, store, and display the required information. The available choices of laser repetition frequency, pulse width, and phase modulation give a wide range of options for matching the bunch configuration of a particular storage ring. Besides the dynamic measurement of the longitudinal profile of each bunch, the instrument can monitor the evolution of the bunch tails, the presence of untrapped particles and their diffusion into nominally empty RF buckets (''ghostbunches'').

  6. Method of measuring a profile of the density of charged particles in a particle beam

    DOEpatents

    Hyman, L.G.; Jankowski, D.J.

    1975-10-01

    A profile of the relative density of charged particles in a beam is obtained by disposing a number of rods parallel to each other in a plane perpendicular to the beam and shadowing the beam. A second number of rods is disposed perpendicular to the first rods in a plane perpendicular to the beam and also shadowing the beam. Irradiation of the rods by the beam of charged particles creates radioactive isotopes in a quantity proportional to the number of charged particles incident upon the rods. Measurement of the radioactivity of each of the rods provides a measure of the quantity of radioactive material generated thereby and, together with the location of the rods, provides information sufficient to identify a profile of the density of charged particles in the beam.

  7. Micro-particle image velocimetry for velocity profile measurements of micro blood flows.

    PubMed

    Pitts, Katie L; Fenech, Marianne

    2013-04-25

    Micro-particle image velocimetry (μPIV) is used to visualize paired images of micro particles seeded in blood flows. The images are cross-correlated to give an accurate velocity profile. A protocol is presented for μPIV measurements of blood flows in microchannels. At the scale of the microcirculation, blood cannot be considered a homogeneous fluid, as it is a suspension of flexible particles suspended in plasma, a Newtonian fluid. Shear rate, maximum velocity, velocity profile shape, and flow rate can be derived from these measurements. Several key parameters such as focal depth, particle concentration, and system compliance, are presented in order to ensure accurate, useful data along with examples and representative results for various hematocrits and flow conditions.

  8. Siderophile Element Profile Measurements in Iron Meteorites Using Laser Ablation ICP-MS

    NASA Technical Reports Server (NTRS)

    Watson, H. C.; Watson, E. B.; McDonough, W. F.

    2005-01-01

    Understanding the behaviour of siderophile elements during cooling of iron meteorites can lead to insight into the general thermal histories of the meteorites as well as their respective parent bodies. Traditionally trace element analyses in meteorites have been done using techniques that only measure the average concentration in each phase. With these methods, all of the spatial information with respect to the distribution of an element within one phase is lost. Measuring concentration profiles of trace elements in meteorites is now possible, with the advent of high-resolution analytical techniques such as laser ablation, inductively coupled plasma mass spectrometry (LA-ICP-MS) with spatial resolution <20 microns. [e.g. 1,2] and secondary ion mass spectrometry [3]. These profiles can give more insight into both the partitioning and diffusive behavior of siderophile elements in metal systems relevant to iron meteorites, as well as parent body cooling rates.

  9. Spectral Fluctuations of Incoherent Radiation And Measurement of Longitudinal Bunch Profile

    SciTech Connect

    Zolotorev, M.S.; Stupakov, G.V.; /SLAC

    2011-09-01

    A method for measurement of ultrashort beam current profile I{sub b}(t) is proposed that is based on detecting fluctuations of the spectral intensity P ({omega}) of single bunch incoherent radiation. We show that the variance of the Fourier transform of the spectrum is proportional to the convolution function of the beam current. After the convolution function is found, using phase retrieval technique one can restore the shape of the pulse in many practical cases.

  10. Construct and Criterion Validities of the Service Need Assessment Profile (SNAP): A Measure of Support for People with Disabilities

    ERIC Educational Resources Information Center

    Guscia, Roma; Harries, Julia; Kirby, Neil; Nettelbeck, Ted; Taplin, John

    2006-01-01

    Background: The "Service Need Assessment Profile" (SNAP) measures individual functional needs in areas of daily living. It produces a support profile, detailing the time allocations for staff support to assist in each area of need. The "Supports Intensity Scale" (SIS) is a support needs assessment scale designed to provide an objective measure of…

  11. Comparison of Air Fluorescence and Ionization Measurements of E.M. Shower Depth Profiles: Test of a UHECR Detector Technique

    SciTech Connect

    Belz, J.; Cao, Z.; Huentemeyer, P.; Jui, C.C.H.; Martens, K.; Matthews, J.; Maestas, M.; Smith, J.; Sokolsky, P.; Springer, R.W.; Thomas, J.; Thomas, S.; Chen, P.; Field, Clive; Hast, C.; Iverson, R.; Ng, J.S.T.; Odian, A.; Reil, K.; Vincke, H.; Walz, D.; /SLAC /Montana U. /Rutgers U., Piscataway /Taiwan, Natl. Taiwan U.

    2005-10-07

    Measurements are reported on the fluorescence of air as a function of depth in electromagnetic showers initiated by bunches of 28.5 GeV electrons. The light yield is compared with the expected and observed depth profiles of ionization in the showers. It validates the use of atmospheric fluorescence profiles in measuring ultra high energy cosmic rays.

  12. 3D micro profile measurement with the method of spatial frequency domain analysis

    NASA Astrophysics Data System (ADS)

    Xu, Yongxiang

    2015-10-01

    3D micro profiles are often needed for measurement in many fields, e.g., binary optics, electronic industry, mechanical manufacturing, aeronautic and space industry, etc. In the case where height difference between two neighboring points of a test profile is equal to or greater than λ / 4, microscopic interferometry based on laser source will no longer be applicable because of the uncertainty in phase unwrapping. As white light possesses the characteristic of interference length approximate to zero, applying it for micro profilometry can avoid the trouble and can yield accurate results. Using self-developed Mirau-type scanning interference microscope, a step-like sample was tested twice, with 128 scanning interferograms recorded for each test. To process each set of the interferograms, the method of spatial frequency domain analysis was adopted. That is, for each point, by use of Furrier transform, white-light interference intensities were decomposed in spatial frequency domain, thus obtaining phase values corresponding to different wavenumbers; by using least square fitting on phases and wave numbers, a group-velocity OPD was gained for the very point; and finally in terms of the relation between relative height and the group-velocity OPD, the profile of the test sample was obtained. Two tests yielded same profile result for the sample, and step heights obtained were 50.88 nm and 50.94 nm, respectively. Meantime, the sample was also measured with a Zygo Newview 7200 topography instrument, with same profile result obtained and step height differing by 0.9 nm. In addition, data processing results indicate that chromatic dispersion equal to and higher than 2nd order is negligible when applying spatial frequency domain analysis method.

  13. Feasibility of lateral dose profile measurements in a small field using TLDs.

    PubMed

    Zhang, Bailin; Zhu, Jinhan; Li, Yinghui; Chen, Shaowen; Chen, Lixin; Liu, Xiaowei

    2015-02-01

    The purpose of this work was to study the feasibility of lateral dose profile measurements in a small field using thermoluminescent dosimeters (TLDs) and to evaluate the impact of the field size on the absorbed dose ratio factor fmd of LiF and Al2O3 TLDs. The Monte Carlo package BEAM/EGSNRC was used to simulate the lateral dose profile in solid water phantoms (RW3 slab phantom) with various field sizes beyond the build-up region for 6 MV x-rays, and a LiF : Mg, Cu, P (GR-200) dosimeter with dimensions of 0.1  ×  0.1  ×  0.1 cm(3) was used to measure the lateral dose profile under the same conditions as the Monte Carlo simulations. To enable comparisons between dosimeters, Gafchromic EBT3 films were used. The results indicate that (1) the measured results are in agreement with the simulated results within the uncertainty of the simulation; (2) the values of fmd for Al2O3 and LiF in a 1  ×  1 cm(2) field are 2.8% and 1.6% less, respectively, than those in a 10  ×  10 cm(2) field; and (3) within the 80% profile region, the dose differences between TLDs and solid water are less than 1%. In the 80-10% profile region, the TLD results are in agreement with the absorbed doses in the solid water within 1 mm. It is generally acceptable to ignore the impact of field size on the absorbed dose ratio factor fmd when the field sizes are larger than 1  ×  1 cm(2) for LiF and 2  ×  2 cm(2) for Al2O3. For 6 MV x-rays, the small GR-200 chip can be used to measure the relative lateral dose profiles of small fields.

  14. Optimal design of reflectometer density profile measurements using a radar systems approach (invited)

    SciTech Connect

    Doyle, E.J.; Kim, K.W.; Peebles, W.A.; Rhodes, T.L.

    1997-01-01

    Reflectometry is an attractive and versatile diagnostic technique that can address a wide range of measurement needs on fusion devices. However, progress in the area of profile measurement has been hampered by the lack of a well-understood basis for the optimum design and implementation of such systems. Such a design basis is provided by the realization that reflectometer systems utilized for density profile measurements are in fact specialized forms of radar systems. In this article five criteria are introduced by which reflectometer systems can be systematically designed for optimal performance: range resolution, spatial sampling, turbulence immunity, bandwidth optimization, and the need for adaptive data processing. Many of these criteria are familiar from radar systems analysis, and are applicable to reflectometry after allowance is made for differences stemming from the nature of the plasma target. These criteria are utilized to critically evaluate current reflectometer density profile techniques and indicate improvements that can impact current and next step devices, such as ITER.{copyright} {ital 1997 American Institute of Physics.}

  15. Dryline on 22 May 2002 During IHOP: Convective Scale Measurements at the Profiling Site

    NASA Technical Reports Server (NTRS)

    Demoz, Belay; Flamant, Cyrille; Miller, David; Evans, Keith; Fabry, Federic; DiGirolamo, Paolo; Whiteman, David; Geerts, Bart; Weckwerth, Tammy; Brown, William

    2004-01-01

    A unique set of measurements of wind, water vapor mixing ratio and boundary layer height variability was observed during the first MOP dryline mission of 22 May 2002. Water vapor mixing ratio from the Scanning Raman Lidar (SRL), high-resolution profiles of aerosol backscatter from the HARLIE and wind profiles from the GLOW are combined with the vertical velocity derived from the NCAR/ISS/MAPR and the high-resolution FMCW radar to reveal the convective variability of the cumulus cloud-topped boundary layer. A combined analysis of the in-situ and remote sensing data from aircraft, radiosonde, lidars, and radars reveals moisture variability within boundary layer updraft and downdraft regions as well as characterizes the boundary layer height variability in the dry and moist sides of the dryline. The profiler site measurements will be tied to aircraft data to reveal the relative intensity and location of these updrafts to the dry line. This study provides unprecedented high temporal and spatial resolution measurements of wind, moisture and backscatter within a dryline and the associated convective boundary layer.

  16. The S-193 radar altimeter experiment. [onboard Skylab for earth surface profile measurement

    NASA Technical Reports Server (NTRS)

    Mcgoogan, J. T.; Miller, L. S.; Brown, G. S.; Hayne, G. S.

    1974-01-01

    The Skylab S-193 altimeter experiment utilizes a 10- and 100-ns pulse length, 13.9-GHz earth-pointed radar system to obtain earth-surface backscatter measurements from the Skylab spacecraft. Objectives of the experiment are to obtain precision measurements of surface profile for uses in geodesy, oceanography, and earth physics, and to measure radar-signal characteristics from an earth-orbit geometry to provide design information for future radar remote-sensors. The technical approach is that of measuring the power impulse response of the scattering surface. The hardware is designed to operate in five modes: waveform or impulse-response measurement and altitude determination; radar cross-section experiment; signal correlation experiment; 10-nsec pulse-compression evaluation; and nadir-seeker experiment.

  17. Radial profile of micro-discharge temperature measured by ultraviolet laser Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Adams, Steven; Caplinger, James

    2012-10-01

    Air micro-discharge temperature profiles have been derived from measurements of elastic Rayleigh scatter of an ultraviolet laser pulse. Rayleigh scatter images have been recorded to measure spatially resolved translational temperatures along the radial dimension of the dc micro-discharge at various currents. The scatter image intensity along the laser beam axis is proportional to the background gas target density and thus, according to the ideal gas law, is inversely proportional to gas translational temperature. By measuring the scatter image with and without a discharge, the temperature was determined in one-dimension along the laser beam passing radially through the discharge. This laser scatter technique was compared to the technique of measuring rotational and vibrational temperatures by passive optical emission spectroscopy (OES) of the N2 second positive system. Results were generally consistent with the common assumption that Tvibrational>>Trotational=Ttranslational. Slight differences between Trotational and Ttranslational measured by laser scatter and OES techniques respectively are discussed.

  18. Radiographic film dosimetry of proton beams for depth-dose constancy check and beam profile measurement.

    PubMed

    Yeo, Inhwan J; Teran, Anthony; Ghebremedhin, Abiel; Johnson, Matt; Patyal, Baldev

    2015-05-08

    Radiographic film dosimetry suffers from its energy dependence in proton dosimetry. This study sought to develop a method of measuring proton beams by the film and to evaluate film response to proton beams for the constancy check of depth dose (DD). It also evaluated the film for profile measurements. To achieve this goal, from DDs measured by film and ion chamber (IC), calibration factors (ratios of dose measured by IC to film responses) as a function of depth in a phantom were obtained. These factors imply variable slopes (with proton energy and depth) of linear characteristic curves that relate film response to dose. We derived a calibration method that enables utilization of the factors for acquisition of dose from film density measured at later dates by adapting to a potentially altered processor condition. To test this model, the characteristic curve was obtained by using EDR2 film and in-phantom film dosimetry in parallel with a 149.65 MeV proton beam, using the method. An additional validation of the model was performed by concurrent film and IC measurement perpendicular to the beam at various depths. Beam profile measurements by the film were also evaluated at the center of beam modulation. In order to interpret and ascertain the film dosimetry, Monte Carlos simulation of the beam was performed, calculating the proton fluence spectrum along depths and off-axis distances. By multiplying respective stopping powers to the spectrum, doses to film and water were calculated. The ratio of film dose to water dose was evaluated. Results are as follows. The characteristic curve proved the assumed linearity. The measured DD approached that of IC, but near the end of the spread-out Bragg peak (SOBP), a spurious peak was observed due to the mismatch of distal edge between the calibration and measurement films. The width of SOBP and the proximal edge were both reproducible within a maximum of 5mm; the distal edge was reproducible within 1 mm. At 5 cm depth, the dose was

  19. Radiographic film dosimetry of proton beams for depth-dose constancy check and beam profile measurement.

    PubMed

    Yeo, Inhwan J; Teran, Anthony; Ghebremedhin, Abiel; Johnson, Matt; Patyal, Baldev

    2015-01-01

    Radiographic film dosimetry suffers from its energy dependence in proton dosimetry. This study sought to develop a method of measuring proton beams by the film and to evaluate film response to proton beams for the constancy check of depth dose (DD). It also evaluated the film for profile measurements. To achieve this goal, from DDs measured by film and ion chamber (IC), calibration factors (ratios of dose measured by IC to film responses) as a function of depth in a phantom were obtained. These factors imply variable slopes (with proton energy and depth) of linear characteristic curves that relate film response to dose. We derived a calibration method that enables utilization of the factors for acquisition of dose from film density measured at later dates by adapting to a potentially altered processor condition. To test this model, the characteristic curve was obtained by using EDR2 film and in-phantom film dosimetry in parallel with a 149.65 MeV proton beam, using the method. An additional validation of the model was performed by concurrent film and IC measurement perpendicular to the beam at various depths. Beam profile measurements by the film were also evaluated at the center of beam modulation. In order to interpret and ascertain the film dosimetry, Monte Carlos simulation of the beam was performed, calculating the proton fluence spectrum along depths and off-axis distances. By multiplying respective stopping powers to the spectrum, doses to film and water were calculated. The ratio of film dose to water dose was evaluated. Results are as follows. The characteristic curve proved the assumed linearity. The measured DD approached that of IC, but near the end of the spread-out Bragg peak (SOBP), a spurious peak was observed due to the mismatch of distal edge between the calibration and measurement films. The width of SOBP and the proximal edge were both reproducible within a maximum of 5mm; the distal edge was reproducible within 1 mm. At 5 cm depth, the dose was

  20. SI2N overview paper: ozone profile measurements: techniques, uncertainties and availability

    NASA Astrophysics Data System (ADS)

    Hassler, B.; Petropavlovskikh, I.; Staehelin, J.; August, T.; Bhartia, P. K.; Clerbaux, C.; Degenstein, D.; De Mazière, M.; Dinelli, B. M.; Dudhia, A.; Dufour, G.; Frith, S. M.; Froidevaux, L.; Godin-Beekmann, S.; Granville, J.; Harris, N. R. P.; Hoppel, K.; Hubert, D.; Kasai, Y.; Kurylo, M. J.; Kyrölä, E.; Lambert, J.-C.; Levelt, P. F.; McElroy, C. T.; McPeters, R. D.; Munro, R.; Nakajima, H.; Parrish, A.; Raspollini, P.; Remsberg, E. E.; Rosenlof, K. H.; Rozanov, A.; Sano, T.; Sasano, Y.; Shiotani, M.; Smit, H. G. J.; Stiller, G.; Tamminen, J.; Tarasick, D. W.; Urban, J.; van der A, R. J.; Veefkind, J. P.; Vigouroux, C.; von Clarmann, T.; von Savigny, C.; Walker, K. A.; Weber, M.; Wild, J.; Zawodny, J.

    2013-11-01

    Peak stratospheric chlorofluorocarbon (CFC) and other ozone depleting substance (ODS) concentrations were reached in the mid to late 1990s. Detection and attribution of the expected recovery of the stratospheric ozone layer in an atmosphere with reduced ODSs as well as efforts to understand the evolution of stratospheric ozone in the presence of increasing greenhouse gases are key current research topics. These require a critical examination of the ozone changes with an accurate knowledge of the spatial (geographical and vertical) and temporal ozone response. For such an examination, it is vital that the quality of the measurements used be as high as possible and measurement uncertainties well quantified. In preparation for the 2014 United Nations Environment Programme (UNEP)/World Meteorological Organization (WMO) Scientific Assessment of Ozone Depletion, the SPARC/IO3C/IGACO-O3/NDACC (SI2N) initiative was designed to study and document changes in the global ozone profile distribution. This requires assessing long-term ozone profile data sets in regards to measurement stability and uncertainty characteristics. The ultimate goal is to establish suitability for estimating long-term ozone trends to contribute to ozone recovery studies. Some of the data sets have been improved as part of this initiative with updated versions now available. This summary presents an overview of stratospheric ozone profile measurement data sets (ground- and satellite-based) available for ozone recovery studies. Here we document measurement techniques, spatial and temporal coverage, vertical resolution, native units and measurement uncertainties. In addition, the latest data versions are briefly described (including data version updates as well as detailing multiple retrievals when available for a given satellite instrument). Archive location information is for each data set is also given.

  1. Stratospheric CH4 and CO2 profiles derived from SCIAMACHY solar occultation measurements

    NASA Astrophysics Data System (ADS)

    Noël, S.; Bramstedt, K.; Hilker, M.; Liebing, P.; Plieninger, J.; Reuter, M.; Rozanov, A.; Bovensmann, H.; Burrows, J. P.

    2015-11-01

    Stratospheric profiles of methane (CH4) and carbon dioxide (CO2) have been derived from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). The retrieval is performed using a method called "Onion Peeling DOAS" (ONPD) which combines an onion peeling approach with a weighting function DOAS (Differential Optical Absorption Spectroscopy) fit. By use of updated pointing information and optimisation of the data selection and of the retrieval approach the altitude range for reasonable CH4 could be extended to about 17 to 45 km. Furthermore, the quality of the derived CO2 has been assessed such that now the first stratospheric profiles of CO2 from SCIAMACHY are available. Comparisons with independent data sets yield an estimated accuracy of the new SCIAMACHY stratospheric profiles of about 5-10 % for CH4 and 2-3 % for CO2. The accuracy of the products is currently mainly restricted by the appearance of unexpected vertical oscillations in the derived profiles which need further investigation. Using the improved ONPD retrieval, CH4 and CO2 stratospheric data sets covering the whole SCIAMACHY time series (August 2002-April 2012) and the latitudinal range between about 50 and 70° N have been derived. Based on these time series, CH4 and CO2 trends have been estimated, which are in reasonable agreement with total column trends for these gases. This shows that the new SCIAMACHY data sets can provide valuable information about the stratosphere.

  2. Water vapour profiles from SCIAMACHY solar occultation measurements derived with an onion peeling approach

    NASA Astrophysics Data System (ADS)

    Noël, S.; Bramstedt, K.; Rozanov, A.; Bovensmann, H.; Burrows, J. P.

    2010-01-01

    A new retrieval method has been developed to derive water vapour number density profiles from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). This method is intentionally kept simple and based on a combination of an onion peeling approach with a modified DOAS (Differential Optical Absorption Spectroscopy) fit in the wavelength region around 940 nm. Reasonable resulting water vapour profiles are currently obtained in the altitude range 15-45 km. Comparisons of the SCIAMACHY profiles with water vapour data provided by the Atmospheric Chemistry Explorer Fourier Transform Spectrometer (ACE-FTS) show an average agreement within about 5% between 20 and 45 km. SCIAMACHY water vapour data tend to be systematically higher than ACE-FTS. These results are in principal confirmed by comparisons with water vapour profiles derived from model data of the European Centre for Medium Range Weather Forecasts (ECMWF), although ECMWF concentrations are systematicly lower than both corresponding SCIAMACHY and ACE-FTS data at all altitudes.

  3. Water vapour profiles from SCIAMACHY solar occultation measurements derived with an onion peeling approach

    NASA Astrophysics Data System (ADS)

    Noël, S.; Bramstedt, K.; Rozanov, A.; Bovensmann, H.; Burrows, J. P.

    2010-04-01

    A new retrieval method has been developed to derive water vapour number density profiles from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). This method is intentionally kept simple and based on a combination of an onion peeling approach with a modified DOAS (Differential Optical Absorption Spectroscopy) fit in the wavelength region around 940 nm. Reasonable resulting water vapour profiles are currently obtained in the altitude range 15-45 km. Comparisons of the SCIAMACHY profiles with water vapour data provided by the Atmospheric Chemistry Explorer Fourier Transform Spectrometer (ACE-FTS) show an average agreement within about 5% between 20 and 45 km. SCIAMACHY water vapour data tend to be systematically higher than ACE-FTS. These results are in principal confirmed by comparisons with water vapour profiles derived from model data of the European Centre for Medium Range Weather Forecasts (ECMWF), although ECMWF concentrations are systematicly lower than both corresponding SCIAMACHY and ACE-FTS data at all altitudes.

  4. Spatially resolved measurements of electron cyclotron resonance ion source beam profile characteristics

    SciTech Connect

    Panitzsch, Lauri; Stalder, Michael; Wimmer-Schweingruber, Robert F.

    2011-03-15

    Simulations predict that the concentric rings and the triangular structures in the profiles of strongly focused ion beams that are found in different experiments should be dominated by ion species with the same or at least similar m/q-ratio. To verify these theoretical predictions we have tuned our ECR ion source to deliver a beam consisting of multiple ion species whose particular m/q-depending focusing ranges from weakly focused to overfocused. We then recorded spatially resolved charge-state distributions of the beam profile at characteristic positions in the plane perpendicular to the beam line. The results validate theoretical predictions and are summarized in this paper. To achieve the required beam profile characteristics we moved the extraction along the beam line to achieve stronger focusing than by only changing the extraction voltage. To fit the regions of interest of the beam profile into the transmission area of the sector magnet, we steered the beam by moving the extraction in the plane perpendicular to the beam axis. The results of both investigations, beam focusing and beam steering by using a 3D-movable extraction, are also reported in this paper. A brief overview of the new beam monitor extensively used during these measurements, the Faraday cup array, is also given.

  5. Road Weather and Connected Vehicles

    NASA Astrophysics Data System (ADS)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  6. Spitzer or neoclassical resistivity: A comparison between measured and model poloidal field profiles on PBX-M

    SciTech Connect

    Kaye, S.M.; Levinton, F.M.; Hatcher, R.; Kaita, R.; Kessel, C.; LeBlanc, B.; McCune, D.C.; Paul, S. )

    1992-03-01

    Direct measurements of the radial profile of the magnetic field line pitch on PBX-M (Phys. Fluids B {bold 2}, 1271 (1990)), coupled with model predictions of these profiles allow a critical comparison with the Spitzer and neoclassical models of plasma parallel resistivity. The measurements of the magnetic field line pitch are made by motional Stark effect polarimetry, while the model profiles are determined by solving the poloidal field diffusion equation in the TRANSP transport code using measured plasma profiles and assuming either Spitzer or neoclassical resistivity. The measured field pitch profiles were available for only seven cases, and the model profiles were distinguishable from each other in only three of those cases due to finite resistive diffusion times. The data in two of these three were best matched by the Spitzer model, especially in the inner-half of the plasma. Portions of the measured pitch profiles for these two cases and the full profiles for other cases, however, departed significantly from both the Spitzer and neoclassical models, indicating a plasma resistivity profile different from either model.

  7. A new device for high precision in situ sediment temperature profile measurements at the seafloor

    NASA Astrophysics Data System (ADS)

    Feseker, T.; Wetzel, G.; Heesemann, B.

    2012-04-01

    In situ sediment temperature profile measurements at the seafloor provide valuable information on fluid seepage, hydrate stability, and ambient temperature of samples. In addition, it can be convenient to approximate other parameters such as concentrations of porewater constituents from temperature or temperature gradient using transfer functions if their distribution is controlled by the same processes and direct quantification involves time-consuming sampling and laboratory analyses. We present a new instrument that can be used to obtain precisely positioned sediment temperature profile measurements from the seafloor during ROV dives. Consisting of a 0.4 m-long sensor rod equipped with eight temperature sensors and a standard data logger, the new T-Stick can be operated by an ROV in a fully autonomous mode. The temperature range of the instrument is -5 °C to 35 °C and it can withstand pressures of up to 600 bar. Compared to previously used instruments, the smaller diameter of the new T-Stick reduces the thermal inertia of the lance and results in shorter equilibration times. Virtual measurements generated by a numerical model showed that the T-Stick provides highly accurate temperature profile measurements with a root mean square error of 0.0027 K for a wide range of thermal sediment properties. Modeled temperature gradients are representative of both normal deep sea settings and cold seep environments with elevated temperature gradients of up to three orders of magnitude above normal background values, which are the primary target areas for T-Stick measurements. Deviations from the true in situ temperature profiles are caused by disturbance of the temperature field by the probe itself and may lead to underestimation of gradients and curvature in the profiles. A first field test of the T-Stick was conducted at the Håkon Mosby mud volcano at 1250 m water depth on the Barents Sea slope, where the new instrument provided useful information about the origin and

  8. Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

    NASA Astrophysics Data System (ADS)

    Ježek, I.; Drinovec, L.; Ferrero, L.; Carriero, M.; Močnik, G.

    2015-01-01

    We have used two methods for measuring emission factors (EFs) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured, and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EFs of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars; hence, we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, and we rather describe the vehicle EF with a characteristic value and a super emission tail.

  9. Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

    NASA Astrophysics Data System (ADS)

    Ježek, I.; Drinovec, L.; Ferrero, L.; Carriero, M.; Močnik, G.

    2014-06-01

    We have used two methods for measuring emission factors (EF) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured; and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EF of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars, hence we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, rather we describe the vehicle EF with a characteristic value and a "super emission" tail.

  10. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    NASA Astrophysics Data System (ADS)

    Achtert, P.; Brooks, I. M.; Brooks, B. J.; Moat, B. I.; Prytherch, J.; Persson, P. O. G.; Tjernström, M.

    2015-09-01

    Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This holds particularly within the planetary boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of winds with a random error below 0.2 m s-1, comparable to the measurement error of standard radiosondes. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  11. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    NASA Astrophysics Data System (ADS)

    Achtert, P.; Brooks, I. M.; Brooks, B. J.; Moat, B. I.; Prytherch, J.; Persson, P. O. G.; Tjernström, M.

    2015-11-01

    Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne Doppler measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic atmospheric boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This held true particularly within the atmospheric boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of vertical winds with a random error below 0.2 m s-1. The comparison of lidar-measured wind and radio soundings gives a mean bias of 0.3 m s-1 (2°) and a mean standard deviation of 1.1 m s-1 (12°) for wind speed (wind direction). The agreement for wind direction degrades with height. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  12. Maximum key-profile correlation (MKC) as a measure of tonal structure in music.

    PubMed

    Takeuchi, A H

    1994-09-01

    Tonal structure is musical organization on the basis of pitch, in which pitches vary in importance and rate of occurrence according to their relationship to a tonal center. Experiment 1 evaluated the maximum key-profile correlation (MKC), a product of Krumhansl and Schmuckler's key-finding algorithm (Krumhansl, 1990), as a measure of tonal structure. The MKC is the maximum correlation coefficient between the pitch class distribution in a musical sample and key profiles, which indicate the stability of pitches with respect to particular tonal centers. The MKC values of melodies correlated strongly with listeners' ratings of tonal structure. To measure the influence of the temporal order of pitches on perceived tonal structure, three measures (fifth span, semitone span, and pitch contour) taken from previous studies of melody perception were also correlated with tonal structure ratings. None of the temporal measures correlated as strongly or as consistently with tonal structure ratings as did the MKC, and nor did combining them with the MKC improve prediction of tonal structure ratings. In Experiment 2, the MKC did not correlate with recognition memory of melodies. However, melodies with very low MKC values were recognized less accurately than melodies with very high MKC values. Although it does not incorporate temporal, rhythmic, or harmonic factors that may influence perceived tonal structure, the MKC can be interpreted as a measure of tonal structure, at least for brief melodies. PMID:7971133

  13. Low altitude wind shear statistics derived from measured and FAA proposed standard wind profiles

    NASA Technical Reports Server (NTRS)

    Dunham, R. E., Jr.; Usry, J. W.

    1984-01-01

    Wind shear statistics were calculated for a simulated data set using wind profiles proposed as a standard and compared to statistics derived from measured wind profile data. Wind shear values were grouped in altitude bands of 100 ft between 100 and 1400 ft, and in wind shear increments of 0.025 kt/ft between + or - 0.600 kt/ft for the simulated data set and between + or - 0.200 kt/ft for the measured set. No values existed outside the + or - 0.200 kt/ft boundaries for the measured data. Frequency distributions, means, and standard deviations were derived for each altitude band for both data sets, and compared. Also, frequency distributions were derived for the total sample for both data sets and compared. Frequency of occurrence of a given wind shear was about the same for both data sets for wind shears, but less than + or 0.10 kt/ft, but the simulated data set had larger values outside these boundaries. Neglecting the vertical wind component did not significantly affect the statistics for these data sets. The frequency of occurrence of wind shears for the flight measured data was essentially the same for each altitude band and the total sample, but the simulated data distributions were different for each altitude band. The larger wind shears for the flight measured data were found to have short durations.

  14. Discharge measurements using a broad-band acoustic Doppler current profiler

    USGS Publications Warehouse

    Simpson, Michael R.

    2002-01-01

    The measurement of unsteady or tidally affected flow has been a problem faced by hydrologists for many years. Dynamic discharge conditions impose an unreasonably short time constraint on conventional current-meter discharge-measurement methods, which typically last a minimum of 1 hour. Tidally affected discharge can change more than 100 percent during a 10-minute period. Over the years, the U.S. Geological Survey (USGS) has developed moving-boat discharge-measurement techniques that are much faster but less accurate than conventional methods. For a bibliography of conventional moving-boat publications, see Simpson and Oltmann (1993, page 17). The advent of the acoustic Doppler current profiler (ADCP) made possible the development of a discharge-measurement system capable of more accurately measuring unsteady or tidally affected flow. In most cases, an ADCP discharge-measurement system is dramatically faster than conventional discharge-measurement systems, and has comparable or better accuracy. In many cases, an ADCP discharge-measurement system is the only choice for use at a particular measurement site. ADCP systems are not yet ?turnkey;? they are still under development, and for proper operation, require a significant amount of operator training. Not only must the operator have a rudimentary knowledge of acoustic physics, but also a working knowledge of ADCP operation, the manufacturer's discharge-measurement software, and boating techniques and safety.

  15. The Effect of Clouds on Water Vapor Profiling from the Millimeter-Wave Radiometric Measurements

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Spinhirne, J. D.; Racette, P.; Chang, L. A.; Hart, W.

    1997-01-01

    Simultaneous measurements with the millimeter-wave imaging radiometer (MIR), cloud lidar system (CLS), and the MODIS airborne simulator (MAS) were made aboard the NASA ER-2 aircraft over the western Pacific Ocean on 17-18 January 1993. These measurements were used to study the effects of clouds on water vapor profile retrievals based on millimeter-wave radiometer measurements. The CLS backscatter measurements (at 0.532 and 1.064 am) provided information on the heights and a detailed structure of cloud layers; the types of clouds could be positively identified. All 12 MAS channels (0.6-13 Am) essentially respond to all types of clouds, while the six MIR channels (89-220 GHz) show little sensitivity to cirrus clouds. The radiances from the 12-/Am and 0.875-gm channels of the MAS and the 89-GHz channel of the MIR were used to gauge the performance of the retrieval of water vapor profiles from the MIR observations under cloudy conditions. It was found that, for cirrus and absorptive (liquid) clouds, better than 80% of the retrieval was convergent when one of the three criteria was satisfied; that is, the radiance at 0.875 Am is less than 100 W/cm.sr, or the brightness at 12 Am is greater than 260 K, or brightness at 89 GHz is less than 270 K (equivalent to cloud liquid water of less than 0.04 g/cm). The range of these radiances for convergent retrieval increases markedly when the condition for convergent retrieval was somewhat relaxed. The algorithm of water vapor profiling from the MIR measurements could not perform adequately over the areas of storm-related clouds that scatter radiation at millimeter wavelengths.

  16. The measure matters: Language dominance profiles across measures in Spanish-English bilingual children.

    PubMed

    Bedore, Lisa M; Peña, Elizabeth D; Summers, Connie L; Boerger, Karin M; Resendiz, Maria D; Greene, Kai; Bohman, Thomas M; Gillam, Ronald B

    2012-07-01

    The purpose of this study was to determine if different language measures resulted in the same classifications of language dominance and proficiency for a group of bilingual pre-kindergarteners and kindergarteners. Data were analyzed for 1029 Spanish-English bilingual pre-kindergarteners who spanned the full range of bilingual language proficiency. Parent questionnaires were used to quantify age of first exposure and current language use. Scores from a short test of semantic and morphosyntactic development in Spanish and English were used to quantify children's performance. Some children who were in the functionally monolingual range based on interview data demonstrated minimal knowledge of their other languages when tested. Current use accounted for more of the variance in language dominance than did age of first exposure. Results indicate that at different levels of language exposure children differed in their performance on semantic and morphosyntax tasks. These patterns suggest that it may be difficult to compare the results of studies that employ different measures of language dominance and proficiency. Current use is likely to be a useful metric of bilingual development that can be used to build a comprehensive picture of child bilingualism.

  17. The Effects of Vibrations Experienced during Road vs. Off-road Cycling.

    PubMed

    Macdermid, P W; Fink, P W; Stannard, S R

    2015-10-01

    The purpose of this investigation was to compare the effects of vibrations experienced during off-road and road cycling. It was hypothesised that additional damping will be expressed through a greater work demand and increased physiological markers when travelling at the same speed over an identical terrain profile. Participants ascended a tar-sealed road climb and a single-track off-road climb at a predetermined speed. Time, speed, power, cadence, heart rate and V̇ O2 were sampled and logged every second while tri-axial accelerometers recorded accelerations (128 Hz) to quantify vibrations experienced. Statistical analysis indicated accelerations to be greater during the off-road condition (p<0.0001) with post-hoc analysis exposing differences (p<0.001) for handlebar, arm, leg and seat post but not the lower back or head. The increased accelerations during off-road riding are associated with the increased vibrations and rolling resistance experienced. This led to increases in the work done (road: 280±69 vs. off-road: 312±74 W, p=0.0003) and, consequentially, a significant increase in the physiological markers V̇ O2 (road: 48.5±7.5 off-road 51.4±7.3 ml·kg(-1)·min(-1), p=0.0033) and heart rate (road: 161±10 off-road 170±10 bpm, p=0.0001) during the off-road condition. Such physiological differences and their causes are important to understand in order to provide suitable training recommendations or technological interventions for improving competitive performance or recreational enjoyment.

  18. Measurement of ion velocity profiles in a magnetic reconnection layer via current sheet jogging

    NASA Astrophysics Data System (ADS)

    Stein, G.; Yoo, J.; Yamada, M.; Ji, H.; Dorfman, S.; Lawrence, E.; Myers, C.; Tharp, T.

    2011-10-01

    In many laboratory plasmas, constructing stationary Langmuir and Mach probe arrays with resolution on the order of electron skin depth is technically difficult, and can introduce significant plasma perturbations. However, complete two- dimensional profiles of plasma density, electron temperature, and ion flow are important for studying the transfer of energy from magnetic fields to particles during magnetic reconnection. Through the use of extra ``Shaping Field'' coils in the Magnetic Reconnection Experiment (MRX) at the Princeton Plasma Physics Laboratory, the inward motion of the current sheet in the reconnection layer can be accelerated, or ``jogged,'' allowing the measurement of different points across the sheet with stationary probes. By acquiring data from Langmuir probes and Mach probes at different locations in the MRX with respect to the current sheet center, profiles of electron density and temperature and a vector plot of two-dimensional ion velocity in the plane of reconnection are created. Results from probe measurements will be presented and compared to profiles generated from computer simulation.

  19. A system for measuring bottom profile, waves and currents in the high-energy nearshore environment

    USGS Publications Warehouse

    Sallenger, A.H.; Howard, P.C.; Fletcher, C. H.; Howd, P.A.

    1983-01-01

    A new data-acquisition system capable of measuring waves, currents and the nearshore profile in breaking waves as high as 5 m has been developed and successfully field-tested. Components of the mechanical system are a sled carrying a vertical mast, a double-drum winch placed landward of the beach, and a line that runs from one drum of the winch around three blocks, which are the corners of a right triangle, to the other drum of the winch. The sled is attached to the shore-normal side of the triangular line arrangement and is pulled offshore by one drum of the winch and onshore by the other. The profile is measured as the sled is towed along the shore-normal transect using an infrared rangefinder mounted landward of the winch and optical prisms mounted on top of the sled's mast. A pressure sensor and two-axis electromagnetic current meter are mounted on the frame of the sled. These data are encoded on the sled and telemetered to a receiving/recording station onshore. Preliminary results suggest that near-bottom offshore-flowing currents during periods of high-energy swell are important in forcing changes to the configuration of the nearshore profile. ?? 1983.

  20. Analysis of Ozone And CO2 Profiles Measured At A Diary Facility

    NASA Astrophysics Data System (ADS)

    Ogunjemiyo, S. O.; Hasson, A. S.; Ashkan, S.; Steele, J.; Shelton, T.

    2015-12-01

    Ozone and carbon dioxide are both greenhouse gasses in the planetary boundary layer. Ozone is a harmful secondary pollutant in the troposphere produced mostly during the day when there is a photochemical reaction in which primary pollutant precursors such as nitrous oxide (NOx) or volatile organic compounds (VOC's) mix with sunlight. As with most pollutants in the lower troposphere, both ozone and carbon dioxide vary in spatial and temporal scale depending on sources of pollution, environmental conditions and the boundary layer dynamics. Among the several factors that influence ozone variation, the seasonal changes in meteorological parameters and availability of ozone precursors are crucial because they control ozone formation and decay. Understanding how the difference in emission sources affect vertical transport of ozone and carbon dioxide is considered crucial to the improvement of their regional inventory sources. The purpose of this study is to characterize vertical transport of ozone and carbon at a diary facility. The study was conducted in the summer of 2011 and 2012 at a commercial dairy facility in Central California and involved profile measurements of ozone and CO2 using electrochemical ozonesondes, meteorological sondes and CO2 probe tethered to a 9 cubic meters helium balloon. On each day of the data collection, multiple balloon launches were made over a period representing different stages of the boundary layer development. The results show ozone and CO2 profiles display different characteristics. Regardless of the time of the day, the CO2 concentration decreases with height with a sharp gradient near the surface that is strengthened by a stable atmospheric condition, a feature suggesting the surface as the source. On the other hand, ozone profiles show greater link to the evolution of the lower boundary layer. Ozone profiles display unique features indicating ozone destruction near the surface. This unusual near the surface, observed even in the

  1. The Valuable Role of Measuring Serum Lipid Profile in Cancer Progression

    PubMed Central

    Ghahremanfard, Farahnaz; Mirmohammadkhani, Majid; Shahnazari, Banafsheh; Gholami, Golnaz; Mehdizadeh, Jamileh

    2015-01-01

    Objective Serum lipid levels are not only associated with etiology, but also with prognosis in cancer. To investigate this issue further, we aimed to evaluate the serum levels of lipids in association with the most important prognostic indicators in cancer patients at the start of chemotherapy. Methods In a retrospective cross-sectional study, using existing medical records obtained from 2009–2014, the data of all incident cancer cases in Iranian patients referred to the Semnan oncology clinic for chemotherapy were analyzed. Data on demographics, cancer type, prognostic indicators (e.g. lymph node involvement, metastasis, and stage of disease), as well as the patient’s lipid profile were collected. We used multiple logistic regression models to show the relationship between prognosis indicators and lipid profile adjusting for age, gender, and type of cancer. Results The data of 205 patients was gathered. We found a significant difference in the lipid profile between different types of cancers (breast, colon, gastric, and ovarian). With the exception of high-density lipoprotein levels in women, which were higher than in men, the means of other lipid profiles were similar between the genders. There was a significant association between higher levels of low-density lipoprotein (LDL >110mg/dL) in the serum and metastasis (adjusted odds ratio=2.4, 95% CI 1.2–3.5). No significant association was reported between lipid profile and lymph nodes involvement and stage of the disease. Conclusion Our study suggested a benefit of measuring serum levels of lipids for predicting cancer progression. Increased LDL levels can be considered a predictive factor for increasing the risk of metastasis. PMID:26421116

  2. Technique for Obtaining Vertical Profiles of Backscattering and Extinction Cross Sections Using Slant Path Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Spinhirne, J. D.; Herman, B. M.

    1973-01-01

    A method is presented for solving for vertical profiles of atmospheric particulate extinction and backscattering cross-sections utilizing monostatic lidar slant path measurements. The method is an extension of work by Fernald. It is shown that the number of assumptions necessary for an iterative solution of extinction and backscattering cross sections can be reduced if lidar slant path measurements are used to solve directly for optical depths. The technique is useful only if sufficiently accurate lidar measurements are available. With highly accurate measurements it is also possible to solve directly for extinction cross sections without an iterative solution of a transcendental equation if the proper reduction scheme is used. The required accuracy is discussed and results showing the effect of errors are presented.

  3. Interferometry based technique for intensity profile measurements of far IR beams.

    PubMed

    Soloviev, Alexander A; Khazanov, Efim A; Kozhevatov, Ilya E; Palashov, Oleg V

    2007-06-20

    We present a novel, to the best of our knowledge, method for measuring the intensity profile of far-IR beams. The method is based on the measurements of nonstationary variation in optical thickness of a fused-silica plate heated by the studied radiation. The optical thickness is observed by means of a reflecting interferometer. Purpose-made experimental setup allows one to measure beams with an aperture of up to 60 mm with a spatial resolution of 1 mm. The accessibility of the utilized technologies and the possibility to easily increase the aperture are the major advantages of this approach. The probable area of application for the method is measurements of beams produced by powerful industrial far-IR lasers. PMID:17538679

  4. Inference of Fast-Ion Density Profile from Tomographic Reconstructions of Fast-Ion Dα Measurements

    NASA Astrophysics Data System (ADS)

    Stagner, L.; Heidbrink, W. W.; Collins, C.; Grierson, B. A.

    2014-10-01

    The fast-ion Dα (FIDA) diagnostic measures light that energetic particles emit in fusion plasmas. The diagnostic is sensitive to different velocity space regions depending on the viewing angle relative to the magnetic field. Consequently, viewing chords that share a radial location give different, yet still valid, results. Velocity space tomography allows for these viewing chords to be combined to infer the complete fast-ion distribution function from the different partial views. If this is done at many radial locations the fast-ion density profile is measured. We demonstrate this method for the case of a classically described, low power, MHD-quiescent plasma from actual FIDA measurements. FIDA measurements were taken at four radial positions, each with four different viewing angles. Simulation results are also shown. Work supported by the US Department of Energy under SC-G903402, DE-FC02-04ER54698 and DE-AC02-09CH11466.

  5. Construct Validity of the Relationship Profile Test: Links with measures of psychopathology and adult attachment

    PubMed Central

    Haggerty, Greg; Bornstein, Robert F.; Khalid, Mohammad; Sharma, Vishal; Riaz, Usman; Blanchard, Mark; Siefert, Caleb J; Sinclair, Samuel J.

    2015-01-01

    This study assessed the construct validity of the Relationship Profile Test (RPT; Bornstein & Languirand, 2003) with a substance abuse sample. One hundred-eight substance abuse patients completed the RPT, Experiences in Close Relationships Scale (ECR-SF; Wei, Russell, Mallinckrodt, & Vogel, 2007), Personality Assessment Inventory (PAI; Morey, 1991), and Symptom Checklist-90-Revised (SCL-90-R: Derogatis 1983). Results suggest that the RPT has good construct validity when compared against theoretically related broadband measures of personality, psychopathology and adult attachment. Overall, health hependency was negatively related to measures of psychopathology and insecure attachment, and overdependence was positively related to measures of psychopathology and attachment anxiety. Many of the predictions regarding RPT detachment and the criterion measures were not supported. Implications of these findings are discussed. PMID:26620463

  6. Simulation and measurement of AES depth profiles; a case study of the C/Ta/C/Si system

    NASA Astrophysics Data System (ADS)

    Zommer, Ludomir; Jablonski, Alexander; Kotis, László; Safran, Gyorgy; Menyhárd, Miklós

    2010-04-01

    A multilayer sample (C (23.3 nm)/Ta (26.5 nm)/C (22.7 nm)/Si substrate) was submitted to AES depth profiling by Ar + ions of energy 1 keV and angles of incidence of 72°, 78°, and 82°. The shapes of the as-measured depth profiles were strongly different emphasizing that the ion-bombardment conditions strongly affects the shapes of measured depth profiles. We simulated the depth profile measured at an angle of incidence of 72° by calculating the backscattering factor, applying attenuation lengths available in the literature, and simulating the ion-bombardment-induced specimen alteration with a TRIDYN simulation and a trial and error method. The good agreement between the calculated and measured depth profiles justified the method applied.

  7. Multispectral Image Road Extraction Based Upon Automated Map Conflation

    NASA Astrophysics Data System (ADS)

    Chen, Bin

    Road network extraction from remotely sensed imagery enables many important and diverse applications such as vehicle tracking, drone navigation, and intelligent transportation studies. There are, however, a number of challenges to road detection from an image. Road pavement material, width, direction, and topology vary across a scene. Complete or partial occlusions caused by nearby buildings, trees, and the shadows cast by them, make maintaining road connectivity difficult. The problems posed by occlusions are exacerbated with the increasing use of oblique imagery from aerial and satellite platforms. Further, common objects such as rooftops and parking lots are made of materials similar or identical to road pavements. This problem of common materials is a classic case of a single land cover material existing for different land use scenarios. This work addresses these problems in road extraction from geo-referenced imagery by leveraging the OpenStreetMap digital road map to guide image-based road extraction. The crowd-sourced cartography has the advantages of worldwide coverage that is constantly updated. The derived road vectors follow only roads and so can serve to guide image-based road extraction with minimal confusion from occlusions and changes in road material. On the other hand, the vector road map has no information on road widths and misalignments between the vector map and the geo-referenced image are small but nonsystematic. Properly correcting misalignment between two geospatial datasets, also known as map conflation, is an essential step. A generic framework requiring minimal human intervention is described for multispectral image road extraction and automatic road map conflation. The approach relies on the road feature generation of a binary mask and a corresponding curvilinear image. A method for generating the binary road mask from the image by applying a spectral measure is presented. The spectral measure, called anisotropy-tunable distance (ATD

  8. Measurements of LHCD current profile and efficiency for simulation validation on Alcator C-Mod

    NASA Astrophysics Data System (ADS)

    Mumgaard, Robert T.

    2014-10-01

    Lower hybrid current drive (LHCD) is an effective tool to significantly modify the magnetic equilibrium by driving off-axis, non-inductive current. On Alcator C-Mod, an upgraded Motional Stark Effect (MSE) diagnostic enables the current profile to be accurately reconstructed during plasmas with strong LHCD and a hard X-ray camera measures the fast electron Bremsstrahlung profile. LHCD is applied for >4 current relaxation times, producing fully-relaxed magnetic equilibria in plasmas with non-inductive current fraction up to unity at currents up to 1.0 MA. C-Mod has developed an extensive database of LHCD performance, spanning a wide range in plasma current, launched n||, LHCD power, Te and plasma density. This dataset provides a unique platform for validation of LHCD current drive simulations with the plasma shape, density, field and LH frequency range envisioned for ITER and future reactors. In these conditions the measured current drive efficiencies are similar to that assumed for ITER with values up to 0.4*1020A/Wm2 despite being in a weak single-pass absorption regime. The driven current is observed to be off-axis, broadening the current profile, raising q0 above 1, suppressing sawteeth, decreasing/reversing the magnetic shear and sometimes destabilizing MHD modes and/or triggering internal transport barriers. Measurements indicate increased efficiency at increased temperature and plasma current but with a complicated dependence on launched n||. The MSE-constrained reconstructions show a loss in current drive efficiency as the plasma density is increased above =1.0×1020 m-3 consistent with previous observations of a precipitous drop in hard x-ray emission. Additionally, the measured driven current profile moves radially outward as the density is increased. Ray tracing simulations using GENRAY-CQL3D qualitatively reproduce these trends showing the rays make many passes through the plasma at high density and predicting a narrower current and HXR profile

  9. Poster — Thur Eve — 02: Measurement of CT radiation profile width using Fuji CR imaging plate raw data

    SciTech Connect

    Bjarnason, T A; Yang, C J

    2014-08-15

    Measuring the CT collimation width and assessing the shape of the overall profile is a relatively straightforward quality control (QC) measure that impacts both image quality and patient dose, and is often required at acceptance and routine testing. Most CT facilities have access to computed radiography (CR) systems, so performing CT collimation profile assessments using CR plates requires no additional equipment. Previous studies have shown how to effectively use CR plates to measure the radiation profile width. However, a major limitation of the previous work is that the full dynamic range of CR detector plates are not used, since the CR processing technology reduces the dynamic range of the DICOM output to 2{sup 10}, requiring the sensitivity and latitude settings of CR reader to be adjusted to prevent clipping of the CT profile data. Such adjustments to CR readers unnecessarily complicate the QC procedure. These clipping artefacts hinder the ability to accurately assess CT collimation width because the full-width at half maximum value of the penumbras are not properly determined if the maximum dose of the profile is not available. Furthermore, any inconsistencies in the radiation profile shape are lost if the profile plateau is clipped off. In this work we developed an opensource Matlab script for straightforward CT profile width measurements using raw CR data that also allows assessment of the profile shape without clipping, and applied this approach during CT QC.

  10. DIAL Measurements of Free-Tropospheric Ozone Profiles in Huntsville, AL

    NASA Technical Reports Server (NTRS)

    Kuang, Shi; Burris, John; Newchurch, Michael J.; Johnson, Steve

    2007-01-01

    A tropospheric ozone Differential Absorption Lidar (DIAL) system, developed jointly by NASA and the University of Alabama at Huntsville (UAH), measures free-tropospheric ozone profiles between 4-10 km. Located at 192 meters altitude in the Regional Atmospheric Profiling Laboratory for Discovery (RAPCD) on the UAH campus in Huntsville, AL, USA, this tropospheric ozone lidar operates under both daytime and nighttime conditions. Frequent coincident ozonesonde flights and theoretical calculations provide evidence to indicate the retrieval accuracy ranges from better than 8% at 4km to 40%-60% at 10 kin with 750-m vertical resolution and 30-minute integration. With anticipated improvements to allow retrievals at both higher and lower altitudes, this ozone lidar, along with co-located aerosol and Doppler Wind Lidars, will provide a unique 18 dataset for investigations of PBL and free-tropospheric chemical and dynamic processes.

  11. The 3-D wake measurements near a hovering rotor for determining profile and induced drag

    NASA Technical Reports Server (NTRS)

    Mcalister, K. W.; Schuler, C. A.; Branum, L.; Wu, J. C.

    1995-01-01

    Primarily an experimental effort, this study focuses on the velocity and vorticity fields in the near wake of a hovering rotor. Drag terminology is reviewed, and the theory for separately determining the profile-and-induced-drag components from wake quantities is introduced. Instantaneous visualizations of the flow field are used to center the laser velocimeter (LV) measurements on the vortex core and to assess the extent of the positional mandering of the trailing vortex. Velocity profiles obtained at different rotor speeds and distances behind the rotor blade clearly indicate the position, size, and rate of movement of the wake sheet and the core of the trailing vortex. The results also show the distribution of vorticity along the wake sheet and within the trailing vortex.

  12. Three-dimensional profile measurement by using an artificial neural network

    NASA Astrophysics Data System (ADS)

    Lu, Naiguang; Deng, Wenyi; Sun, Shaofeng; Yang, Jiping

    1998-08-01

    This paper introduces 3D profiles noncontact measurement method by using a kind of artificial neural network- backpropagation network. It makes a detail discussion on optical system, data acquisition, and how to train the BP network. An object is projected by a laser stripe light, and the lien image of the object is captured by a CCD camera. The input data of BP network is given from a series of image on CCD by certain image processing technology. Once a mapping relationship of coordinates between CCD camera image plane and related position in object's space is set up by sing BP network, the image plane coordinates of any objects are used as the input data of BP network it will immediately obtain the corresponding coordinates in space according to the output. Thus the profile can be easily established by these coordinates. This method reduces the requirement for system accuracy, and no need to test and a light the whole system in advance accurately.

  13. Experimental estimation of the photons visiting probability profiles in time-resolved diffuse reflectance measurement

    NASA Astrophysics Data System (ADS)

    Sawosz, P.; Kacprzak, M.; Weigl, W.; Borowska-Solonynko, A.; Krajewski, P.; Zolek, N.; Ciszek, B.; Maniewski, R.; Liebert, A.

    2012-12-01

    A time-gated intensified CCD camera was applied for time-resolved imaging of light penetrating in an optically turbid medium. Spatial distributions of light penetration probability in the plane perpendicular to the axes of the source and the detector were determined at different source positions. Furthermore, visiting probability profiles of diffuse reflectance measurement were obtained by the convolution of the light penetration distributions recorded at different source positions. Experiments were carried out on homogeneous phantoms, more realistic two-layered tissue phantoms based on the human skull filled with Intralipid-ink solution and on cadavers. It was noted that the photons visiting probability profiles depend strongly on the source-detector separation, the delay between the laser pulse and the photons collection window and the complex tissue composition of the human head.

  14. Dose profile measurements during respiratory-gated lung stereotactic radiotherapy: A phantom study

    NASA Astrophysics Data System (ADS)

    Jong, W. L.; Wong, J. H. D.; Ng, K. H.; Ung, N. M.

    2016-03-01

    During stereotactic body radiotherapy, high radiation dose (∼60 Gy) is delivered to the tumour in small fractionation regime. In this study, the dosimetric characteristics were studied using radiochromic film during respiratory-gated and non-gated lung stereotactic body radiotherapy (SBRT). Specifically, the effect of respiratory cycle and amplitude, as well as gating window on the dosimetry were studied. In this study, the dose profiles along the irradiated area were measured. The dose profiles for respiratory-gated radiation delivery with different respiratory or tumour motion amplitudes, gating windows and respiratory time per cycle were in agreement with static radiation delivery. The respiratory gating system was able to deliver the radiation dose accurately (±1.05 mm) in the longitudinal direction. Although the treatment time for respiratory-gated SBRT was prolonged, this approach can potentially reduce the margin for internal tumour volume without compromising the tumour coverage. In addition, the normal tissue sparing effect can be improved.

  15. Measurement of a zonal wind profile on Titan by Doppler tracking of the Cassini entry probe

    NASA Technical Reports Server (NTRS)

    Atkinson, D. H.; Pollack, J. B.; Seiff, A.

    1990-01-01

    A program, called the Cassini mission, intended to study the Saturn system by utilizing a Saturn orbiter and a probe descending to the surface of Titan, is discussed. Winds are expected to cause perturbations to the probe local horizontal velocity, resulting in an anomalous drift in the probe location and a shift in the frequency of the probe telemetry, due to the Doppler effect. By using an iterative algorithm, in which the time variation of the probe telemetry frequency is monitored throughout the descent, and the probe trajectory is updated to reflect the effect of wind on the probe location, a highly accurate relative wind profile can be recovered. By adding a single wind velocity, measured by independent means, an absolute wind profile can be obtained. However, the accuracy of the zonal winds recovery is limited by errors in trajectory, and frequency.

  16. Generation and Measurement of Relativistic Electron Bunches Characterized by a Linearly Ramped Current Profile

    SciTech Connect

    England, R. J.; Rosenzweig, J. B.; Travish, G.

    2008-05-30

    We report the first successful attempt to generate ultrashort (1-10 ps) relativistic electron bunches characterized by a ramped longitudinal current profile that rises linearly from head to tail and then falls sharply to zero. Bunches with this type of longitudinal shape may be applied to plasma-based accelerator schemes as an optimized drive beam, and to free-electron lasers as a means of reducing asymmetry in microbunching due to slippage. The scheme used to generate the ramped bunches employs an anisochronous dogleg beam line with nonlinear correction elements to compress a beam having an initial positive time-energy chirp. The beam current profile is measured using a deflecting mode cavity, and a pseudoreconstruction of the beam's longitudinal phase space distribution is obtained by using this diagnostic with a residual horizontal dispersion after the dogleg.

  17. An intercomparison of ozone profile measurements from LIMS, SAGE, and SBUV

    NASA Technical Reports Server (NTRS)

    Fleig, A. J.; Bhartia, P. K.; Wong, C. K.; Klenk, K. F.

    1983-01-01

    Ozone profile measurements by the Limb IR Monitor of Stratosphere (LIMS) and the Solar Backscatter UV (SBUV) aboard the Nimbus satellite, and the Stratospheric Aerosol and Gas Experiment (SAGE) aboard the AEM-2 satellite are intercompared in an effort to assess the quality of satellite ozone retrieval techniques. Good correlation between LIMS and SBUV observations is noted in the ozone layer bounded by pressures of 31.2-15.6 mb; absolute differences are generally less than 10 percent, with similar zonal variations. Above 35 km SAGE values are systematically larger than SBUV or LIMS. The differences generally increase with height and are largest in the tropics. Finally, excellent agreement is noted to exist among the three data sets between 10 and 35 km of altitude with respect to the latitude dependence of the ozone profiles.

  18. Time-resolved wave profile measurements in copper to Megabar pressures

    SciTech Connect

    Chhabildas, L C; Asay, J R

    1981-01-01

    Many time-resolved techniques have been developed which have greatly aided in the understanding of dynamic material behavior such as the high pressure-dynamic strength of materials. In the paper, time-resolved measurements of copper (at shock-induced high pressures and temperatures) are used to illustrate the capability of using such techniques to investigate high pressure strength. Continuous shock loading and release wave profiles have been made in copper to 93 GPa using velocity interferometric techniques. Fine structure in the release wave profiles from the shocked state indicates an increase in shear strength of copper to 1.5 GPa at 93 GPa from its ambient value of 0.08 GPa.

  19. Measuring discharge with acoustic Doppler current profilers from a moving boat

    USGS Publications Warehouse

    Mueller, David S.; Wagner, Chad R.; Rehmel, Michael S.; Oberg, Kevin A.; Rainville, Francois

    2013-01-01

    The use of acoustic Doppler current profilers (ADCPs) from a moving boat is now a commonly used method for measuring streamflow. The technology and methods for making ADCP-based discharge measurements are different from the technology and methods used to make traditional discharge measurements with mechanical meters. Although the ADCP is a valuable tool for measuring streamflow, it is only accurate when used with appropriate techniques. This report presents guidance on the use of ADCPs for measuring streamflow; this guidance is based on the experience of U.S. Geological Survey employees and published reports, papers, and memorandums of the U.S. Geological Survey. The guidance is presented in a logical progression, from predeployment planning, to field data collection, and finally to post processing of the collected data. Acoustic Doppler technology and the instruments currently (2013) available also are discussed to highlight the advantages and limitations of the technology. More in-depth, technical explanations of how an ADCP measures streamflow and what to do when measuring in moving-bed conditions are presented in the appendixes. ADCP users need to know the proper procedures for measuring discharge from a moving boat and why those procedures are required, so that when the user encounters unusual field conditions, the procedures can be adapted without sacrificing the accuracy of the streamflow-measurement data.

  20. How well can we Measure the Vertical Profile of Tropospheric Aerosol Extinction?

    NASA Technical Reports Server (NTRS)

    Schmid, Beat; Ferrare, R.; Flynn, C.; Elleman, R.; Covert, D.; Strawa, A.; Welton, E.; Turner, D.; Jonsson, H.; Redemann, J.

    2005-01-01

    The recent Department of Energy Atmospheric Radiation Measurement (ARM) Aerosol Intensive Operations Period (MOP, May 2003) yielded one of the best measurement sets obtained to-date to assess our ability to measure the vertical profile of ambient aerosol extinction sigma(sub ep)(lambda) in the lower troposphere. During one month, a heavily instrumented aircraft with well characterized aerosol sampling ability carrying well proven and new aerosol instrumentation, devoted most of the 60 available flight hours to flying vertical profiles over the heavily instrumented ARM Southern Great Plains (SGP) Climate Research Facility (CRF). This allowed us to compare vertical extinction profiles obtained from 6 different instuments: airborne Sun photometer (AATS-14), airborne nephelometer/absorption photometer, airborne cavity ring-down system, ground-based Raman lidar and 2 ground-based elastic backscatter lidars. We find the in-situ measured sigma(sub ep)(lambda) to be lower than the AATS-14 derived values. Bias differences are 0.002 - 0.004 K/m equivalent to 12-17% in the visible, or 45% in the near-infrared. On the other hand, we find that with respect to AATS-14, the lidar sigma(sub ep)(lambda) are higher. An unnoticed loss of sensitivity of the Raman lidar had occurred leading up to AIOP and we expect better agreement from the recently restored system looking at the collective results from 6 field campaigns conducted since 1996, airborne in situ measurements of sigma(sub ep)(lambda) tend to be biased slightly low (17% at visible wavelengths) when compared to airborne Sun photometer sigma(sub ep)(lambda). On the other hand, sigma(sub ep)(lambda) values derived from lidars tend to have no or positive biases. From the bias differences we conclude that the typical systematic error associated with measuring the tropospheric vertical profile of the ambient aerosol extinction with current state of-the art instrumentation is 15-20% at visible wavelengths and potentially larger in

  1. Measurements of Aerosol Vertical Profiles and Optical Properties during INDOEX 1999 Using Micro-Pulse Lidars

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Voss, Kenneth J.; Quinn, Patricia K.; Flatau, Piotr J.; Markowicz, Krzysztof; Campbell, James R.; Spinhirne, James D.; Gordon, Howard R.; Johnson, James E.; Starr, David OC. (Technical Monitor)

    2001-01-01

    Micro-pulse lidar systems (MPL) were used to measure aerosol properties during the Indian Ocean Experiment (INDOEX) 1999 field phase. Measurements were made from two platforms: the NOAA ship RN Ronald H. Brown, and the Kaashidhoo Climate Observatory (KCO) in the Maldives. Sunphotometers were used to provide aerosol optical depths (AOD) needed to calibrate the MPL. This study focuses on the height distribution and optical properties (at 523 nm) of aerosols observed during the campaign. The height of the highest aerosols (top height) was calculated and found to be below 4 km for most of the cruise. The marine boundary layer (MBL) top was calculated and found to be less than 1 km. MPL results were combined with air mass trajectories, radiosonde profiles of temperature and humidity, and aerosol concentration and optical measurements. Humidity varied from approximately 80% near the surface to 50% near the top height during the entire cruise. The average value and standard deviation of aerosol optical parameters were determined for characteristic air mass regimes. Marine aerosols in the absence of any continental influence were found to have an AOD of 0.05 +/- 0.03, an extinction-to-backscatter ratio (S-ratio) of 33 +/- 6 sr, and peak extinction values around 0.05/km (near the MBL top). The marine results are shown to be in agreement with previously measured and expected values. Polluted marine areas over the Indian Ocean, influenced by continental aerosols, had AOD values in excess of 0.2, S-ratios well above 40 sr, and peak extinction values approximately 0.20/km (near the MBL top). The polluted marine results are shown to be similar to previously published values for continental aerosols. Comparisons between MPL derived extinction near the ship (75 m) and extinction calculated at ship-level using scattering measured by a nephelometer and absorption using a PSAP were conducted. The comparisons indicated that the MPL algorithm (using a constant S-ratio throughout the

  2. Magnetically filtered Faraday probe for measuring the ion current density profile of a Hall thruster

    SciTech Connect

    Rovey, Joshua L.; Walker, Mitchell L.R.; Gallimore, Alec D.; Peterson, Peter Y.

    2006-01-15

    The ability of a magnetically filtered Faraday probe (MFFP) to obtain the ion current density profile of a Hall thruster is investigated. The MFFP is designed to eliminate the collection of low-energy, charge-exchange (CEX) ions by using a variable magnetic field as an ion filter. In this study, a MFFP, Faraday probe with a reduced acceptance angle (BFP), and nude Faraday probe are used to measure the ion current density profile of a 5 kW Hall thruster operating over the range of 300-500 V and 5-10 mg/s. The probes are evaluated on a xenon propellant Hall thruster in the University of Michigan Large Vacuum Test Facility at operating pressures within the range of 4.4x10{sup -4} Pa Xe (3.3x10{sup -6} Torr Xe) to 1.1x10{sup -3} Pa Xe (8.4x10{sup -6} Torr Xe) in order to study the ability of the Faraday probe designs to filter out CEX ions. Detailed examination of the results shows that the nude probe measures a greater ion current density profile than both the MFFP and BFP over the range of angular positions investigated for each operating condition. The differences between the current density profiles obtained by each probe are attributed to the ion filtering systems employed. Analysis of the results shows that the MFFP, operating at a +5 A solenoid current, provides the best agreement with flight-test data and across operating pressures.

  3. SUNYAEV-ZEL'DOVICH CLUSTER PROFILES MEASURED WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

    Plagge, T.; Cho, H.-M.; George, E. M.; Holzapfel, W. L.; Benson, B. A.; Aird, K. A.; Hrubes, J. D.; Ade, P. A. R.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Keisler, R.; De Haan, T.; Dobbs, M. A.; Holder, G. P.; Hall, N. R.; Halverson, N. W.; Joy, M.

    2010-06-20

    We present Sunyaev-Zel'dovich (SZ) measurements of 15 massive X-ray-selected galaxy clusters obtained with the South Pole Telescope (SPT). The SZ cluster signals are measured at 150 GHz, and concurrent 220 GHz data are used to reduce astrophysical contamination. Radial profiles are computed using a technique that takes into account the effects of the beams and filtering. In several clusters, significant SZ decrements are detected out to a substantial fraction of the virial radius. The profiles are fit to the {beta}-model and to a generalized Navarro-Frenk-White (NFW) pressure profile, and are scaled and stacked to probe their average behavior. We find model parameters that are consistent with previous studies: {beta} = 0.86 and r{sub core}/r{sub 500} = 0.20 for the {beta}-model, and ({alpha}{sub n}, {beta}{sub n}, {gamma}{sub n}, c{sub 500}) = (1.0, 5.5, 0.5, 1.0) for the generalized NFW model. Both models fit the SPT data comparably well, and both are consistent with the average SZ profile out to beyond r{sub 500}. The integrated Compton-y parameter Y{sub SZ} is computed for each cluster using both model-dependent and model-independent techniques, and the results are compared to X-ray estimates of cluster parameters. We find that Y{sub SZ} scales with Y{sub X} and gas mass with low scatter. Since these observables have been found to scale with total mass, our results point to a tight mass-observable relation for the SPT cluster survey.

  4. Radiation Budget Profiles measured through the Atmosphere with a Return Glider Radiosonde

    NASA Astrophysics Data System (ADS)

    Philipona, R.; Kraeuchi, A.; Kivi, R.

    2015-12-01

    Very promising radiation budget profile measurements through the atmosphere were made in 2011 with a balloon borne short- and longwave net radiometer. New and improved radiation sensors from Kipp&Zonen are now used in a glider aircraft together with a standard Swiss radiosonde from Meteolabor AG. This new return glider radiosonde (RG-R), is lifted up with double balloon technique to prevent pendulum motion and to keep the radiation instruments as horizontal as possible during the ascent measuring phase. The RG-R is equipped with a release mechanism and an autopilot that flies the glider radiosonde back to the launch site, or to a predefined open space, where it releases a parachute for landing once it is 100 meter above ground. The RG-R was successfully tested and deployed for tropospheric and stratospheric radiation measurements up to 30 hPa (24 km altitude) at the GRUAN sites Payerne (Switzerland) and Sodankylä (Finland). Radiation profiles and the radiation budget through the atmosphere during different daytimes and under cloud-free and cloudy situations will be shown in relation to temperature and humidity at the surface and in the atmosphere. The RG-R flight characteristics and new measurement possibilities will also be discussed.

  5. Comparing shear-wave velocity profiles inverted from multichannel surface wave with borehole measurements

    USGS Publications Warehouse

    Xia, J.; Miller, R.D.; Park, C.B.; Hunter, J.A.; Harris, J.B.; Ivanov, J.

    2002-01-01

    Recent field tests illustrate the accuracy and consistency of calculating near-surface shear (S)-wave velocities using multichannel analysis of surface waves (MASW). S-wave velocity profiles (S-wave velocity vs. depth) derived from MASW compared favorably to direct borehole measurements at sites in Kansas, British Columbia, and Wyoming. Effects of changing the total number of recording channels, sampling interval, source offset, and receiver spacing on the inverted S-wave velocity were studied at a test site in Lawrence, Kansas. On the average, the difference between MASW calculated Vs and borehole measured Vs in eight wells along the Fraser River in Vancouver, Canada was less than 15%. One of the eight wells was a blind test well with the calculated overall difference between MASW and borehole measurements less than 9%. No systematic differences were observed in derived Vs values from any of the eight test sites. Surface wave analysis performed on surface data from Wyoming provided S-wave velocities in near-surface materials. Velocity profiles from MASW were confirmed by measurements based on suspension log analysis. ?? 2002 Elsevier Science Ltd. All rights reserved.

  6. Effectiveness of Three Rehabilitation Treatments for Unpaved Forest Roads

    NASA Astrophysics Data System (ADS)

    Donnellycolt, A. K.; MacDonald, L. H.

    2008-12-01

    Up to $1 million per year is being spent to reduce sediment production and delivery from unpaved roads and protect the remaining Chinook salmon habitat on the Lassen National Forest in northeastern California, but little is known about the effectiveness of these treatments. The goal of this study is to estimate the reduction in road sediment production and road-stream connectivity due to three road rehabilitation treatments: 1) rocking and out-sloping, 2) road closures, and 3) road decommissioning. Sediment production was estimated for 4.6 km of untreated roads and 27 km of treated roads by measuring the volumes of erosion features. Road-stream connectivity was assessed by following the rills and sediment plumes emanating from each road segment. The mean volume of erosion features from the untreated roads was 16 m3 km-1 (s.d. = 15 m3 km-1). The measured mean volume for 26 rocked and out-sloped road sections was 5.9 m3 km- 1 (s.d.= 16 m3 km-1), which was 37% of the mean for the untreated roads. However, just three of the 26 treated sections accounted for 88% of the total volume. The closed roads had a similar mean volume of erosional features as the rocked and out-sloped roads, and three of the 11 sections accounted for 97% of the total volume. The mean erosion volume for the decommissioned roads was an order of magnitude higher at 41 m3 km-1 (s.d.= 92 m3 km-1). Again the distribution was highly skewed with three of the 22 sections accounting for 83% of the total, while 11 sections had no significant erosion features. Road-stream connectivity was less than 10% of the surveyed length for the untreated roads, the rocked and out-sloped roads, and the closed roads. In contrast, 28% of the surveyed length of the decommissioned roads was connected to the stream channel network. The highly skewed distributions of erosion volumes show that most of the road-related sediment is coming from a few 'bad' roads. This indicates that detailed road surveys are needed to identify

  7. Mars dayside temperature from airglow limb profiles : comparison with in situ measurements and models

    NASA Astrophysics Data System (ADS)

    Gérard, Jean-Claude; Bougher, Stephen; Montmessin, Franck; Bertaux, Jean-Loup; Stiepen, A.

    The thermal structure of the Mars upper atmosphere is the result of the thermal balance between heating by EUV solar radiation, infrared heating and cooling, conduction and dynamic influences such as gravity waves, planetary waves, and tides. It has been derived from observations performed from different spacecraft. These include in situ measurements of orbital drag whose strength depends on the local gas density. Atmospheric temperatures were determined from the altitude variation of the density measured in situ by the Viking landers and orbital drag measurements. Another method is based on remote sensing measurements of ultraviolet airglow limb profiles obtained over 40 years ago with spectrometers during the Mariner 6 and 7 flybys and from the Mariner 9 orbiter. Comparisons with model calculations indicate that they both reflect the CO_2 scale height from which atmospheric temperatures have been deduced. Upper atmospheric temperatures varying over the wide range 270-445 K, with a mean value of 325 K were deduced from the topside scale height of the airglow vertical profile. We present an analysis of limb profiles of the CO Cameron (a(3) Pi-X(1) Sigma(+) ) and CO_2(+) doublet (B(2) Sigma_u(+) - X(2) PiΠ_g) airglows observed with the SPICAM instrument on board Mars Express. We show that the temperature in the Mars thermosphere is very variable with a mean value of 270 K, but values ranging between 150 and 400 K have been observed. These values are compared to earlier determinations and model predictions. No clear dependence on solar zenith angle, latitude or season is apparent. Similarly, exospheric variations with F10.7 in the SPICAM airglow dataset are small over the solar minimum to moderate conditions sampled by Mars Express since 2005. We conclude that an unidentified process is the cause of the large observed temperature variability, which dominates the other sources of temperature variations.

  8. Measurements of Turbulence Dissipation Rates in the Planetary Boundary Layer from Wind Profiling Radars

    NASA Astrophysics Data System (ADS)

    McCaffrey, K.; Bianco, L.; Wilczak, J. M.; Johnston, P. E.

    2015-12-01

    When forecasting winds at a wind plant for energy production, the turbulence parameterizations are crucial for understanding wind plant performance. Recent research shows that the turbulence (eddy) dissipation rate in planetary boundary layer (PBL) parameterization schemes introduces significant uncertainty in the Weather Research and Forecasting (WRF) model. Thus, developing the capability to measure dissipation rates in the PBL will allow for identification of weaknesses in, and improvements to the parameterizations. We use data from a 915-MHz wind profiling radar at the Boulder Atmospheric Observatory, collected during the XPIA campaign in spring 2015, to identify the critical parameters for measuring eddy dissipation rates using the spectral width method. Radar set-up parameters (e.g., spectral resolution), post-processing techniques (e.g., filtering for non-atmospheric signals), and spectral averaging, are optimized to capture the most accurate power spectrum for measuring spectral widths for use in the computation of the eddy dissipation rates. These estimates are compared to six heights of turbulence-measuring sonic anemometers from 50 - 300 m on a co-located 300 m tower as verification, showing encouraging results. These methods are then applied to the wind profiling radar data being collected in the Wind Forecasting Improvement Project 2 (WFIP2), a DOE funded campaign that aims to improve the ability to forecast hub-height winds from WRF-based models. This campaign uses of a suite of field observations, including many wind profiling radars, in the Columbia River Gorge, a location with complex terrain where turbulence parameterizations are critical for wind energy prediction.

  9. Linkages between unpaved forest roads and streambed sediment: why context matters in directing road restoration

    USGS Publications Warehouse

    Al-Chokhachy, Robert K.; Black, Tom A.; Thomas, Cameron; Luce, Charlie H.; Rieman, Bruce; Cissel, Richard; Carlson, Anne; Hendrickson, Shane; Archer, Eric K.; Kershner, Jeffrey L.

    2016-01-01

    Unpaved forest roads remain a pervasive disturbance on public lands and mitigating sediment from road networks remains a priority for management agencies. Restoring roaded landscapes is becoming increasingly important for many native coldwater fishes that disproportionately rely on public lands for persistence. However, effectively targeting restoration opportunities requires a comprehensive understanding of the effects of roads across different ecosystems. Here, we combine a review and a field study to evaluate the status of knowledge supporting the conceptual framework linking unpaved forest roads with streambed sediment. Through our review, we specifically focused on those studies linking measures of the density of forest roads or sediment delivery with empirical streambed sediment measures. Our field study provides an example of a targeted effort of linking spatially explicit estimates of sediment production with measures of streambed sediment. Surprisingly, our review uncovered few studies (n = 8) that empirically tested the conceptual framework linking unpaved forest roads and streambed sediment, and the results varied considerably. Field results generally supported the conceptual model that unpaved forest roads can control streambed sediment quality, but demonstrated high-spatial variability in the effects of forest roads on streambed sediment and the need to address hotspots of sediment sources. The importance of context in the effects of forest roads is apparent in both our review and field data, suggesting the need for in situ studies to avoid misdirected restoration actions.

  10. Improvement of GOME-2 Tropospheric Ozone Profile Retrievals from Joint UV/Visible Measurements

    NASA Astrophysics Data System (ADS)

    Liu, X.; Zoogman, P.; Chance, K.; Cai, Z.; Nowlan, C. R.

    2015-12-01

    It has been shown that adding visible measurements in the Chappuis band to UV measurements in the Hartley/Huggins bands can significantly enhance retrieval sensitivity to lower tropospheric ozone from backscattered solar radiances due to deeper photon penetration in the visible to the surface than in the ultraviolet. The first NASA EVI TEMPO (Tropospheric Emissions: Monitoring of Pollution) instrument is being developed to measure backscattered solar radiation in two channels (~290-490 and 540-740 nm) and make atmospheric pollution measurements over North America from the Geostationary orbit. However, this retrieval enhancement has yet to be solidly demonstrated from existing measurements due to the weak ozone absorption in the visible and strong interference from surface reflectance and the requirement of accurate radiometric calibration across different spectral channels. We present GOME-2 retrievals from joint UV/visible measurements using the SAO optimal estimation based ozone profile retrieval algorithm, to directly explore the retrieval improvement in lower tropospheric ozone from additional visible measurements. To reduce the retrieval interference from surface reflectance, we add characterization of surface spectral reflectance in the visible based on ASTER and other surface reflectance spectra and MODIS BRDF climatology into the ozone profile algorithm using two approaches: fitting several EOFs (Empirical Orthogonal Functions) and scaling reflectance spectra. We also perform empirical radiometric calibration of the GOME-2 data based on radiative transfer simulations. We evaluate the retrieval improvement of joint UV/visible retrieval over the UV retrieval. These results clearly show the potential of using the visible to improve lower tropospheric ozone retrieval.

  11. Are emissions of black carbon from gasoline vehicles underestimated? Insights from near and on-road measurements.

    PubMed

    Liggio, John; Gordon, Mark; Smallwood, Gregory; Li, Shao-Meng; Stroud, Craig; Staebler, Ralf; Lu, Gang; Lee, Patrick; Taylor, Brett; Brook, Jeffrey R

    2012-05-01

    Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO(2) measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies. PMID:22309316

  12. Vulnerability Analysis and Evaluation of Urban Road System in Tianjin

    NASA Astrophysics Data System (ADS)

    Liu, Y. Q.; Wu, X.

    In recent years, with the development of economy, the road construction of our country has entered into a period of rapid growth. The road transportation network has been expanding and the risk of disasters is increasing. In this paper we study the vulnerability of urban road system in Tianjin. After analyzed many risk factors of the urban road system security, including road construction, road traffic and the natural environment, we proposed an evaluation index of vulnerability of urban road system and established the corresponding evaluation index system. Based on the results of analysis and comprehensive evaluation, appropriate improvement measures and suggestions which may reduce the vulnerability of the road system and improve the safety and reliability of the road system are proposed.

  13. 2. Big Creek Road, worm fence and road at trailhead. ...

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

    2. Big Creek Road, worm fence and road at trailhead. - Great Smoky Mountains National Park Roads & Bridges, Big Creek Road, Between State Route 284 & Big Creek Campground, Gatlinburg, Sevier County, TN

  14. HOW FAR TO THE NEAREST ROAD?

    EPA Science Inventory

    Ecological impacts from roads may be the rule rather than the exception in most watersheds of the conterminous United States. We measured total area, and forestland area located within nine distances of the nearest road of any type in each of 2,108 watersheds nationwide. Overall,...

  15. Estimates of the potential temperature profile from lidar measurements of boundary layer evolution

    NASA Astrophysics Data System (ADS)

    Holder, H. E.; Eichinger, W. E.

    2006-10-01

    The Soil Moisture-Atmosphere Coupling Experiment (SMACEX) was conducted in the Walnut Creek Watershed near Ames, Iowa, over the period from 15 June to 11 July 2002. A main focus of SMACEX is the investigation of the interactions between the atmospheric boundary layer, surface moisture, and canopy. A vertically staring elastic lidar was used to provide a high time resolution, continuous record of the mixed layer height at the edge between a soybean and a corn field. The height and thickness of the entrainment zone are used to estimate the vertical potential temperature profile in the boundary layer using surface energy measurements in the Batchvarova-Gryning mixed layer model. Calculated values of potential temperature compared well to radiosonde measurements taken simultaneously with the lidar measurements. The root-mean-square difference between the lidar-derived values and the balloon-based values is 1.20°C.

  16. Rocket Measurement of a Daytime Electron Density Profile up to 620 Kilometers

    NASA Technical Reports Server (NTRS)

    Jackson, J. E.; Bauer, S. J.

    1961-01-01

    On April 27, 1961 at 1502 EST a four-stage research rocket was fired from Wallops Island, Virginia, to measure the ionospheric electron density distribution by means of Seddon's CW propagation technique. This experimental technique is based upon the dispersive Doppler effect measured at two harmonically related frequencies, in this case f = 12.267 Mc and 6f = 73.6 Mc. The electron density profile measured above the peak of the F2 region is representative of a diffusive-equilibrium distribution in an isothermal ionosphere having a temperature of 1640 deg +/- 90 deg K. This result, when compared with satellite and other data, indicates that the upper ionosphere is in thermodynamic equilibrium.

  17. Measurement of the stratospheric hydrogen peroxide concentration profile using far infrared thermal emission spectroscopy

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Johnson, D. G.; Traub, W. A.; Jucks, K. W.

    1991-01-01

    The first unequivocal measurement of hydrogen peroxide in the stratosphere have been made, a concentration profile obtained from a balloon platform using Fourier transform thermal emission spectroscopy in the far infrared. Measurements were made using the 112/cm R-Q5 branch of the rotational-torsional spectrum, with some confirmation from the 94/cm R-Q4 branch. The volume mixing ratio of H2O2 is 1.6 x 10 to the -10th at 38.4 km, decreasing to 0.6 x 10 to the -10th at 23.8 km, with uncertainties of about 16 percent. These measurements are compared to a recent stratospheric model calculation.

  18. Validation of Ozone Profiles Retrieved from SAGE III Limb Scatter Measurements

    NASA Technical Reports Server (NTRS)

    Rault, Didier F.; Taha, Ghassan

    2007-01-01

    Ozone profiles retrieved from Stratospheric Aerosol and Gas Experiment (SAGE III) limb scatter measurements are compared with correlative measurements made by occultation instruments (SAGE II, SAGE III and HALOE [Halogen Occultation Experiment]), a limb scatter instrument (Optical Spectrograph and InfraRed Imager System [OSIRIS]) and a series of ozonesondes and lidars, in order to ascertain the accuracy and precision of the SAGE III instrument in limb scatter mode. The measurement relative accuracy is found to be 5-10% from the tropopause to about 45km whereas the relative precision is found to be less than 10% from 20 to 38km. The main source of error is height registration uncertainty, which is found to be Gaussian with a standard deviation of about 350m.

  19. Using CellProfiler for Automatic Identification and Measurement of Biological Objects in Images

    PubMed Central

    Bray, Mark-Anthony; Vokes, Martha S.; Carpenter, Anne E.

    2015-01-01

    Visual analysis is required to perform many biological experiments, from counting colonies to measuring the size or fluorescence intensity of individual cells or organisms. This unit outlines the use of CellProfiler, a free, open-source image analysis tool that extracts quantitative information from biological images. It includes a step-by-step protocol for automated analysis of the number, color, and size of yeast colonies growing on agar plates, but the methods can be adapted to identify and measure many other types of objects in images. The flexibility of the software allows experimenters to create pipelines of adjustable modules to fit different biological experiments and to generate accurate measurements from dozens or even hundreds of thousands of images. PMID:25559103

  20. Use of an Acoustic Doppler Current Profiler (ADCP) to Measure Hypersaline Bidirectional Discharge

    USGS Publications Warehouse

    Johnson, K.K.; Loving, B.L.

    2002-01-01

    The U.S. Geological Survey measures the exchange of flow between the north and south parts of Great Salt Lake, Utah, as part of a monitoring program. Turbidity and bidirectional flow through the breach in the causeway that divides the lake into two parts makes it difficult to measure discharge with conventional streamflow techniques. An acoustic Doppler current profiler (ADCP) can be used to more accurately define the angles of flow and the location of the interface between the layers of flow. Because of the high salinity levels measured in Great Salt Lake (60-280 parts per thousand), special methods had to be developed to adjust ADCP-computed discharges for the increased speed of sound in hypersaline waters and for water entrained at the interface between flow layers.

  1. Raman lidar profiling of atmospheric water vapor: Simultaneous measurements with two collocated systems

    NASA Technical Reports Server (NTRS)

    Goldsmith, J. E. M.; Bisson, Scott E.; Ferrare, Richard A.; Evans, Keith D.; Whiteman, David N.; Melfi, S. H.

    1994-01-01

    Raman lidar is a leading candidate for providing the detailed space- and time-resolved measurements of water vapor needed by a variety of atmospheric studies. Simultaneous measurements of atmospheric water vapor are described using two collocated Raman lidar systems. These lidar systems, developed at the NASA/Goddard Space Flight Center and Sandia National Laboratories, acquired approximately 12 hours of simultaneous water vapor data during three nights in November 1992 while the systems were collocated at the Goddard Space Flight Center. Although these lidar systems differ substantially in their design, measured water vapor profiles agreeed within 0.15 g/kg between altitudes of 1 and 5 km. Comparisons with coincident radiosondes showed all instruments agreed within 0.2 g/kg in this same altitude range. Both lidars also clearly showed the advection of water vapor in the middle troposphere and the pronounced increase in water vapor in the nocturnal boundary layer that occurred during one night.

  2. On-road measurement of gas and particle phase pollutant emission factors for individual heavy-duty diesel trucks.

    PubMed

    Dallmann, Timothy R; DeMartini, Steven J; Kirchstetter, Thomas W; Herndon, Scott C; Onasch, Timothy B; Wood, Ezra C; Harley, Robert A

    2012-08-01

    Pollutant concentrations in the exhaust plumes of individual diesel trucks were measured at high time resolution in a highway tunnel in Oakland, CA, during July 2010. Emission factors for individual trucks were calculated using a carbon balance method, in which pollutants measured in each exhaust plume were normalized to measured concentrations of carbon dioxide. Pollutants considered here include nitric oxide, nitrogen dioxide (NO(2)), carbon monoxide, formaldehyde, ethene, and black carbon (BC), as well as optical properties of emitted particles. Fleet-average emission factors for oxides of nitrogen (NO(x)) and BC respectively decreased 30 ± 6 and 37 ± 10% relative to levels measured at the same location in 2006, whereas a 34 ± 18% increase in the average NO(2) emission factor was observed. Emissions distributions for all species were skewed with a small fraction of trucks contributing disproportionately to total emissions. For example, the dirtiest 10% of trucks emitted half of total NO(2) and BC emissions. Emission rates for NO(2) were found to be anticorrelated with all other species considered here, likely due to the use of catalyzed diesel particle filters to help control exhaust emissions. Absorption and scattering cross-section emission factors were used to calculate the aerosol single scattering albedo (SSA, at 532 nm) for individual truck exhaust plumes, which averaged 0.14 ± 0.03. PMID:22799607

  3. Near-road modeling and measurement of cerium-containing particles generated by nanoparticle diesel fuel additive use

    EPA Science Inventory

    Cerium oxide nanoparticles (nCe) are used as a fuel-borne catalyst in diesel engines to reduce particulate emissions, yet the environmental and human health impacts of the exhaust particles are not well understood. To bridge the gap between emission measurements and ambient impac...

  4. Water Vapour Profiles from SCIAMACHY Solar Occultation Measurements derived with Onion Peeling DOAS

    NASA Astrophysics Data System (ADS)

    Noël, S.; Bramstedt, K.; Rozanov, A.; Bovensmann, H.; Burrows, J. P.

    2009-04-01

    Water vapour is the most important greenhouse gas and plays a key role in atmospheric chemistry and transport. Most of the water vapour is located in the troposphere where it significantly contributes to weather and climate. Because the tropopause acts as a cold trap, the water vapour density in the stratosphere is significantly lower and decreases rapidly with increasing altitude. However, the amount of stratospheric water vapour plays an important role in the generation of Polar Stratospheric Clouds (PSCs), which in turn influence strongly the amount of ozone in polar regions. Trends in stratospheric water vapour are determined by methane oxidation, transport through the tropopause and by the Brewer-Dobson circulation. To seperate the various effects there is a clear need for global long term measurements of lower stratospheric water vapour, which can be provided by satellite measurements. A new retrieval method (called "Onion Peeling DOAS") has been developed to derive water vapour number density profiles from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). This method is intentionally kept simple and based on a combination of an onion peeling approach with a modified DOAS (Differential Optical Absorption Spectroscopy) fit in the wavelength region around 940 nm. The resulting water vapour profiles currently cover the altitude range 15-50 km. Here, first retrieval results and comparisons of the SCIAMACHY profiles with water vapour data provided by the Atmospheric Chemistry Explorer Fourier Transform Spectrometer (ACE-FTS) and model data of the European Centre for Medium Range Weather Forecasts (ECMWF) are shown.

  5. Range dependent sediment sound speed profile measurements using the image source method.

    PubMed

    Pinson, S; Guillon, L; Holland, C W

    2013-07-01

    This paper presents a range dependent sediment sound speed profile measurement obtained using the image source method. This technique is based on the analysis of the seafloor reflected acoustic wave as a collection of image sources which positions are linked with the thick-nesses and the sound speed of the sediment stack. The data used were acquired by the NURC in 2009 during the Clutter09 experiment. The equipment used was an autonomous undersea vehicle towing a 1600-3500 Hz frequency band source and a 32 m horizontal line array of 32 hydrophones at 12 m above the seabed. Under the assumption of locally range independent seabed properties, the moving horizontal array provides successive range independent sediment sound speed profiles along a track to obtain the range and depth dependent structure of the seafloor. Two key steps include recovery of the time-varying unknown array shape from the data and spatial filtering of the successive sound speed profiles. A comparison of the image source method result and seismic data along nearly the same 14 km track indicates that the seabed stratigraphy is correctly mapped by this method. PMID:23862794

  6. Current Profile and Magnetic Structure Measurements through Tangential Soft X-Ray Imaging in Compact Tori

    SciTech Connect

    Fonck, Raymond J.

    2004-07-12

    This report describes the fabrication and tests of a tangentially imaging soft X-ray (SXR) camera diagnostic for fusion energy plasma research. It can be used for the determination of the current distribution in strongly shaped toroidal magnetically confined plasmas, such as those found in spherical tori or advanced tokamaks. It included the development of both an appropriate imaging SXR camera and image analysis techniques necessary to deduce the plasma shape and current distribution. The basic camera concept consists of a tangentially viewing pinhole imaging system with thin-film SXR filters, a scintillator screen to provide SXR to visible conversion, a fast shuttering system, and an sensitive visible camera imaging device. The analysis approach consists of integrating the 2-D SXR image data into a Grad-Shafranov toroidal equilibrium solver code to provide strong constraints on the deduced plasma current and pressure profiles. Acceptable sensitivity in the deduced current profile can be obtained if the relative noise in the measured image can be kept in the range of 1% or less. Tests on the Pegasus Toroidal Experiment indicate very flat safety factor profiles in the plasma interior.

  7. All-Fiber Airborne Coherent Doppler Lidar to Measure Wind Profiles

    NASA Astrophysics Data System (ADS)

    Liu, Jiqiao; Zhu, Xiaopeng; Diao, Weifeng; Zhang, Xin; Liu, Yuan; Bi, Decang; Jiang, Liyuan; Shi, Wei; Zhu, Xiaolei; Chen, Weibiao

    2016-06-01

    An all-fiber airborne pulsed coherent Doppler lidar (CDL) prototype at 1.54μm is developed to measure wind profiles in the lower troposphere layer. The all-fiber single frequency pulsed laser is operated with pulse energy of 300μJ, pulse width of 400ns and pulse repetition rate of 10kHz. To the best of our knowledge, it is the highest pulse energy of all-fiber eye-safe single frequency laser that is used in airborne coherent wind lidar. The telescope optical diameter of monostatic lidar is 100 mm. Velocity-Azimuth-Display (VAD) scanning is implemented with 20 degrees elevation angle in 8 different azimuths. Real-time signal processing board is developed to acquire and process the heterodyne mixing signal with 10000 pulses spectra accumulated every second. Wind profiles are obtained every 20 seconds. Several experiments are implemented to evaluate the performance of the lidar. We have carried out airborne wind lidar experiments successfully, and the wind profiles are compared with aerological theodolite and ground based wind lidar. Wind speed standard error of less than 0.4m/s is shown between airborne wind lidar and balloon aerological theodolite.

  8. Studies of longitudinal profile of electron bunches and impedance measurements at Indus-2 synchrotron radiation source

    NASA Astrophysics Data System (ADS)

    Garg, Akash Deep; Yadav, S.; Kumar, Mukesh; Shrivastava, B. B.; Karnewar, A. K.; Ojha, A.; Puntambekar, T. A.

    2016-04-01

    Indus-2 is a 3rd generation synchrotron radiation source at the Raja Ramanna Centre for Advanced Technology (RRCAT) in India. We study the longitudinal profile of electrons in Indus-2 by using dual sweep synchroscan streak camera at visible diagnostic beamline. In this paper, the longitudinal profiles of electron bunch are analyzed by filling beam current in a single bunch mode. These studies are carried at injection energy (550 MeV) and at ramped beam energy (2.5 GeV). The effects of the wakefield generated interactions between the circulating electrons and the surrounding vacuum chamber are analyzed in terms of measured effects on longitudinal beam distribution. The impedance of the storage ring is obtained by fitting the solutions of Haissinski equation to the measured bunch lengthening with different impedance models. The impedance of storage ring obtained by a series R+L impedance model indicates a resistance (R) of 1350±125 Ω, an inductance (L) of 180±25 nH and broadband impedance of 2.69 Ω. These results are also compared with the values obtained from measured synchronous phase advancing and scaling laws. These studies are very useful in better understanding and control of the electromagnetic interactions.

  9. Flying spot laser triangulation scanner using lateral synchronization for surface profile precision measurement.

    PubMed

    Zhang, Hanlin; Ren, Yongjie; Liu, Changjie; Zhu, Jigui

    2014-07-10

    High-speed surface profile measurement with high precision is crucial for target inspection and quality control. In this study, a laser scanner based on a single point laser triangulation displacement sensor and a high-speed rotating polygon mirror is proposed. The autosynchronized scanning scheme is introduced to alleviate the trade-off between the field of view and the range precision, which is the inherent deficiency of the conventional triangulation. The lateral synchronized flying spot technology has excellent characteristics, such as programmable and larger field of view, high immunity to ambient light or secondary reflections, high optical signal-to-noise ratio, and minimum shadow effect. Owing to automatic point-to-point laser power control, high accuracy and superior data quality are possible when measuring objects featuring varying surface characteristics even in demanding applications. The proposed laser triangulation scanner is validated using a laboratory-built prototype and practical considerations for design and implementation of the system are described, including speckle noise reduction method and real-time signal processing. A method for rapid and accurate calibration of the laser triangulation scanner using lookup tables is also devised, and the system calibration accuracy is generally smaller than ±0.025  mm. Experimental results are presented and show a broad application prospect for fast surface profile precision measurement.

  10. Optimal tuning and calibration of bendable mirrors with slope measuring profilers

    SciTech Connect

    McKinney, Wayne; Kirschman, Jonathan; MacDowell, Alastair; Warwick, Tony; Yashchuk, Valeriy

    2009-06-22

    We describe a technique to optimally tune and calibrate bendable x-ray optics for sub-micron focusing. The focusing is divided between two elliptically cylindrical reflecting elements, a Kirkpatrick-Baez (KB) pair. Each optic is shaped by applying unequal bending couples to each end of a flat mirror. The developed technique allowsoptimal tuning of these systems using surface slope data obtained with a slope measuring instrument, the long trace profiler (LTP). Due to the near linearity of the problem, the minimal set of data necessary for the tuning of each bender, consists of only three slope traces measured before and after a single adjustment of each bending couple. The data are analyzed with software realizing a method of regression analysis with experimentally found characteristic functions of the benders. The resulting approximation to the functional dependence of the desired shape provides nearly final settings. Moreover, the characteristic functions of the benders found in the course of tuning, can be used for retuning to a new desired shape without removal from the beamline and re-measuring. We perform a ray trace, using profiler data for the finally tuned optics, predicting the performance to be expected during use of the optics on the beamline.

  11. Measurement of gas temperature and convection velocity profiles in a dc atmospheric glow discharge

    SciTech Connect

    Stepaniuk, Vadim P.; Ioppolo, Tindaro; Oetuegen, M. Volkan; Sheverev, Valery A.

    2007-12-15

    Gas temperature and convective velocity distributions are presented for an unconfined glow discharge in air at atmospheric pressure, with electric currents ranging between 30 and 92 mA. The vertically oriented discharge was formed between a pin anode (top) and an extended cathode. The temperature and velocity profiles were measured using laser-induced Rayleigh scattering and laser Doppler anemometry techniques, respectively. The temperature field exhibited a conical shape with the radius of hot temperature zone increasing toward the anode. A maximum temperature of 2470 K was observed on the discharge axis with the discharge current of 92 mA. Air velocity measurements around the discharge demonstrated that the shape and magnitude of the temperature field are strongly affected by natural convection. Estimates indicate that convective losses may account for more than 50% of the power input into the positive column of the discharge. The measured temperature fields and convective velocity profiles provide a set of data that is important for the evaluation of dc atmospheric glow discharges in various applications such as sound manipulation and acoustic noise mitigation.

  12. Measurement of the near-wall velocity profile for a nanofluid flow inside a microchannel

    NASA Astrophysics Data System (ADS)

    Kanjirakat, Anoop; Sadr, Reza

    2015-11-01

    Hydrodynamics and anomalous heat transfer enhancements have been reported in the past for colloidal suspensions of nano-sized particles dispersed in a fluid (nanofluids). However, such augmentations may manifest itself by study of fluid flow characteristics near in the wall region. Present experimental study reports near-wall velocity profile for nanofluids (silicon dioxide nanoparticles in water) measured inside a microchannel. An objective-based nano-Particle Image Velocimetry (nPIV) technique is used to measure fluid velocity within three visible depths, O(100nm), from the wall. The near-wall fluid velocity profile is estimated after implementing the required corrections for optical properties and effects caused by hindered Brownian motion, wall-particle interactions, and non-uniform exponential illumination on the measurement technique. The fluid velocities of nanofluids at each of the three visible depths are observed to be higher than that of the base fluid resulting in a higher shear rate in this region. The relative increase in shear rates for nanofluids is believed to be the result of the near-wall shear-induced particle migration along with the Brownian motion of the nanoparticles. This research is funded by NPRP grant # 08-574-2-239 from the Qatar National Research Fund (a member of Qatar Foundation).

  13. Vertical profiles of aerosol volume from high-spectral-resolution infrared transmission measurements. I. Methodology.

    PubMed

    Eldering, A; Irion, F W; Chang, A Y; Gunson, M R; Mills, F P; Steele, H M

    2001-06-20

    The wavelength-dependent aerosol extinction in the 800-1250-cm(-1) region has been derived from ATMOS (atmospheric trace molecule spectroscopy) high-spectral-resolution IR transmission measurements. Using models of aerosol and cloud extinction, we have performed weighted nonlinear least-squares fitting to determine the aerosol-volume columns and vertical profiles of stratospheric sulfate aerosol and cirrus cloud volume. Modeled extinction by use of cold-temperature aerosol optical constants for a 70-80% sulfuric-acid-water solution shows good agreement with the measurements, and the derived aerosol volumes for a 1992 occultation are consistent with data from other experiments after the eruption of Mt. Pinatubo. The retrieved sulfuric acid aerosol-volume profiles are insensitive to the aerosol-size distribution and somewhat sensitive to the set of optical constants used. Data from the nonspherical cirrus extinction model agree well with a 1994 mid-latitude measurement indicating the presence of cirrus clouds at the tropopause.

  14. Surface profile measurement of highly reflective silicon wafer using wavelength tuning interferometer

    NASA Astrophysics Data System (ADS)

    Kim, Yangjin; Sugita, Naohiko; Mitsuishi, Mamoru

    2016-03-01

    In phase-shifting Fizeau interferometers, phase-shift errors and multiple-beam interference are the most common sources of systematic error affecting high-precision phase measurements. Nonsinusoidal waveforms can be minimized by applying synchronous detection with more than four samples. However, when phase-shift calibration is inaccurate, these algorithms cannot eliminate the effects of nonsinusoidal characteristics. Moreover, when measuring the surface profile of highly reflective samples, the calculated phase is critically determined not only by the decrease in the fringe contrast, but also by the coupling error between the harmonics and phase-shift errors. In this study, we calculate phase errors using phase-shifting algorithms that take into account the coupling error. We show that the 4N - 3 algorithm, which consists of a polynomial window function and a discrete Fourier transform term, results in the smallest phase error. As a demonstration, the surface profile of a highly reflective silicon wafer is measured using a wavelength-tuning Fizeau interferometer and the 4N - 3 algorithm.

  15. Highlights from a decade of Ice-Tethered Profiler measurements of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Timmermans, M. L. E.; Toole, J. M.; Krishfield, R. A.; Proshutinsky, A. Y.; Cole, S. T.; Laney, S. R.

    2014-12-01

    Intensive sampling from drifting autonomous Ice-Tethered Profiler (ITP) systems since 2004 has brought new understanding to Arctic Ocean structure and dynamics, ocean heat and mixing processes, circulation and eddies, and seasonal characteristics of under-ice biological activity. This talk will review highlights of ITP studies, and demonstrate the value of the year-round water-column measurements extending from beneath the sea ice to 750 m depth across the major Arctic basins. ITP profiles show the detailed distribution of upper-ocean freshwater and heat content over the past decade, including the changing influence of Pacific and Atlantic-origin layers. ITPs allow for assessment of vertical fluxes of deep-ocean heat in context with the strong upper-ocean density stratification, while in the surface ocean ITPs equipped with velocity sensors provide turbulent ocean-to-ice fluxes. All upper-ocean layers exhibit a rich mesoscale eddy field, and ITP measurements also reveal an active surface-layer submesoscale flow field, with scales of a few kilometers or less. ITPs equipped with bio-optical sensors have returned the first year-round measurements under sea ice of biomass related to phytoplankton and sea-ice algae in the upper-water column, establishing important regional differences in the seasonal cycle and relationships to temperature and salinity variability.

  16. Retrievals of Profiles of Fine And Coarse Aerosols Using Lidar And Radiometric Space Measurements

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Tanre, Didier; Leon, Jean-Francois; Pelon, Jacques; Lau, William K. M. (Technical Monitor)

    2002-01-01

    In couple of years we expect the launch of the CALIPSO lidar spaceborne mission designed to observe aerosols and clouds. CALIPSO will collect profiles of the lidar attenuated backscattering coefficients in two spectral wavelengths (0.53 and 1.06 microns). Observations are provided along the track of the satellite around the globe from pole to pole. The attenuated backscattering coefficients are sensitive to the vertical distribution of aerosol particles, their shape and size. However the information is insufficient to be mapped into unique aerosol physical properties and vertical distribution. Infinite number of physical solutions can reconstruct the same two wavelength backscattered profile measured from space. CALIPSO will fly in formation with the Aqua satellite and the MODIS spectro-radiometer on board. Spectral radiances measured by MODIS in six channels between 0.55 and 2.13 microns simultaneously with the CALIPSO observations can constrain the solutions and resolve this ambiguity, albeit under some assumptions. In this paper we describe the inversion method and apply it to aircraft lidar and MODIS data collected over a dust storm off the coast of West Africa during the SHADE experiment. It is shown that the product of the single scattering albedo, omega, and the phase function, P, for backscattering can be retrieved from the synergism between measurements avoiding a priori hypotheses required for inverting lidar measurements alone. The resultant value of (omega)P(180 deg.) = 0.016/sr are significantly different from what is expected using Mie theory, but are in good agreement with recent results obtained from lidar observations of dust episodes. The inversion is robust in the presence of noise of 10% and 20% in the lidar signal in the 0.53 and 1.06 pm channels respectively. Calibration errors of the lidar of 5 to 10% can cause an error in optical thickness of 20 to 40% respectively in the tested cases. The lidar calibration errors cause degradation in the

  17. Road safety and road traffic accidents in Saudi Arabia

    PubMed Central

    Mansuri, Farah A.; Al-Zalabani, Abdulmohsen H.; Zalat, Marwa M.; Qabshawi, Reem I.

    2015-01-01

    Objectives: To identify the changing trends and crucial preventive approaches to road traffic accidents (RTAs) adopted in the Kingdom of Saudi Arabia (KSA) over the last 2.5 decades, and to analyze aspects previously overlooked. Methods: This systematic review was based on evidence of RTAs in KSA. All articles published during the last 25 years on road traffic accident in KSA were analyzed. This study was carried out from December 2013 to May 2014 in the Department of Family and Community Medicine, Taibah University, Al-Madinah Al-Munawwarah, KSA. Results: Road traffic accidents accounted for 83.4% of all trauma admissions in 1984-1989, and no such overall trend was studied thereafter. The most frequently injured body regions as reported in the latest studies were head and neck, followed by upper and lower extremities, which was found to be opposite to that of the studies reported earlier. Hospital data showed an 8% non-significant increase in road accident mortalities in contrast to police records of a 27% significant reduction during the years 2005-2010. Excessive speeding was the most common cause reported in all recent and past studies. Conclusion: Disparity was common in the type of reporting of RTAs, outcome measures, and possible causes over a period of 2.5 decade. All research exclusively looked into the drivers’ faults. A sentinel surveillance of road crashes should be kept in place in the secondary and tertiary care hospitals for all regions of KSA. PMID:25828277

  18. MEASUREMENT OF THE HALO BIAS FROM STACKED SHEAR PROFILES OF GALAXY CLUSTERS

    SciTech Connect

    Covone, Giovanni; Sereno, Mauro

    2014-04-01

    We present observational evidence of the two-halo term in the stacked shear profile of a sample of ∼1200 optically selected galaxy clusters based on imaging data and the public shear catalog from the CFHTLenS. We find that the halo bias, a measure of the correlated distribution of matter around galaxy clusters, has amplitude and correlation with galaxy cluster mass in very good agreement with the predictions based on the LCDM standard cosmological model. The mass-concentration relation is flat but higher than theoretical predictions. We also confirm the close scaling relation between the optical richness of galaxy clusters and their mass.

  19. Measured depth-dependence of waveguide invariant in shallow water with a summer profile.

    PubMed

    Turgut, Altan; Fialkowski, Laurie T; Schindall, Jeffrey A

    2016-06-01

    Acoustic-intensity striation patterns were measured in the time-frequency domain using an L-shaped array and two simultaneously towed broadband (350-650 Hz) sources at depths above and below the thermocline under summer profile conditions. Distributions of the waveguide invariant parameter β, extracted from the acoustic striation patterns, peak at different values when receivers are above or below the thermocline for a source that is below the thermocline. However, the distributions show similar characteristics when the source is above the thermocline. Experimental results are verified by a numerical analysis of phase slowness, group slowness, and relative amplitudes of acoustic modes.

  20. Measurement of beam profiles by terahertz sensor card with cholesteric liquid crystals.

    PubMed

    Tadokoro, Yuzuru; Nishikawa, Tomohiro; Kang, Boyoung; Takano, Keisuke; Hangyo, Masanori; Nakajima, Makoto

    2015-10-01

    We demonstrate a sensor card with cholesteric liquid crystals (CLCs) for terahertz (THz) waves generated from a nonlinear crystal pumped by a table-top laser. A beam profile of the THz waves is successfully visualized as color change by the sensor card without additional electronic devices, power supplies, and connecting cables. Above the power density of 4.3  mW/cm2, the approximate beam diameter of the THz waves is measured using the hue image that is digitalized from the picture of the sensor card. The sensor card is low in cost, portable, and suitable for various situations such as THz imaging and alignment of THz systems.

  1. Rayleigh beacon for measuring the surface profile of a radio telescope.

    PubMed

    Padin, S

    2014-12-01

    Millimeter-wavelength Rayleigh scattering from water droplets in a cloud is proposed as a means of generating a bright beacon for measuring the surface profile of a radio telescope. A λ=3  mm transmitter, with an output power of a few watts, illuminating a stratiform cloud, can generate a beacon with the same flux as Mars in 10 GHz bandwidth, but the beacon has a narrow line width, so it is extremely bright. The key advantage of the beacon is that it can be used at any time, and positioned anywhere in the sky, as long as there are clouds.

  2. Retrieval of Greenhouse Gas Profiles from SCIMACHY Solar Occultation Measurements with Onion Peeling DOAS

    NASA Astrophysics Data System (ADS)

    Noel, Stefan; Bramstedt, Klaus; Reuter, Max; Rozanov, Alexei; Bovensmann, Heinrich; Burrows, John P.

    2010-12-01

    A new retrieval method (called 'Onion Peeling DOAS') has been developed to derive stratospheric profiles of atmospheric constituents from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). The method has already been successfully applied to water vapour. However, the Onion Peeling DOAS method can also be applied to other atmospheric constituents. Here, we summarise the results for stratospheric water vapour and present first results for other greenhouse gases, namely methane (CH4) and carbon dioxide (CO2).

  3. Measured depth-dependence of waveguide invariant in shallow water with a summer profile.

    PubMed

    Turgut, Altan; Fialkowski, Laurie T; Schindall, Jeffrey A

    2016-06-01

    Acoustic-intensity striation patterns were measured in the time-frequency domain using an L-shaped array and two simultaneously towed broadband (350-650 Hz) sources at depths above and below the thermocline under summer profile conditions. Distributions of the waveguide invariant parameter β, extracted from the acoustic striation patterns, peak at different values when receivers are above or below the thermocline for a source that is below the thermocline. However, the distributions show similar characteristics when the source is above the thermocline. Experimental results are verified by a numerical analysis of phase slowness, group slowness, and relative amplitudes of acoustic modes. PMID:27369170

  4. Rayleigh beacon for measuring the surface profile of a radio telescope.

    PubMed

    Padin, S

    2014-12-01

    Millimeter-wavelength Rayleigh scattering from water droplets in a cloud is proposed as a means of generating a bright beacon for measuring the surface profile of a radio telescope. A λ=3  mm transmitter, with an output power of a few watts, illuminating a stratiform cloud, can generate a beacon with the same flux as Mars in 10 GHz bandwidth, but the beacon has a narrow line width, so it is extremely bright. The key advantage of the beacon is that it can be used at any time, and positioned anywhere in the sky, as long as there are clouds. PMID:25607971

  5. Measuring the profile of the emission zone in polymeric organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Gather, Malte C.; Flämmich, Michael; Danz, Norbert; Michaelis, Dirk; Meerholz, Klaus

    2009-06-01

    The profile of the emission zone (PEZ) in the emissive layer (EML) of polymeric organic light-emitting diodes (OLEDs) is determined by fitting the measured electroluminescence spectrum of the device with a series of simulated spectra that correspond to different emitter locations. The studied OLEDs are based on two different blue-emitting conjugated polymers. In one case, the PEZ is confined to a 10 nm thin sheet at the anode indicating electron dominated current in the EML. In OLEDs based on the other emitter, the PEZ spreads over the entire EML.

  6. Measurement of profile drag on an airplane in flight by the momentum method. Part II

    NASA Technical Reports Server (NTRS)

    Schrenk, Martin

    1930-01-01

    The purpose of this section is to survey the present status of scientific knowledge of the causes which produce drag, in order, if possible, to establish the relation between the individual results and the actual phenomena which demonstrate the fundamental importance of surface conditions. A discussion of the boundary layer is followed by: relations between frictional and form drag, application to profile-drag measurements, and different kinds of roughness. High-pressure wind tunnel tests are discussed along with roughness and maximum lift.

  7. Towards the development of a hybrid-integrated chip interferometer for online surface profile measurements.

    PubMed

    Kumar, P; Martin, H; Jiang, X

    2016-06-01

    Non-destructive testing and online measurement of surface features are pressing demands in manufacturing. Thus optical techniques are gaining importance for characterization of complex engineering surfaces. Harnessing integrated optics for miniaturization of interferometry systems onto a silicon wafer and incorporating a compact optical probe would enable the development of a handheld sensor for embedded metrology applications. In this work, we present the progress in the development of a hybrid photonics based metrology sensor device for online surface profile measurements. The measurement principle along with test and measurement results of individual components has been presented. For non-contact measurement, a spectrally encoded lateral scanning probe based on the laser scanning microscopy has been developed to provide fast measurement with lateral resolution limited to the diffraction limit. The probe demonstrates a lateral resolution of ∼3.6 μm while high axial resolution (sub-nanometre) is inherently achieved by interferometry. Further the performance of the hybrid tuneable laser and the scanning probe was evaluated by measuring a standard step height sample of 100 nm. PMID:27370493

  8. Validation of streamflow measurements made with M9 and RiverRay acoustic Doppler current profilers

    USGS Publications Warehouse

    Boldt, Justin A.; Oberg, Kevin A.

    2015-01-01

    The U.S. Geological Survey (USGS) Office of Surface Water (OSW) previously validated the use of Teledyne RD Instruments (TRDI) Rio Grande (in 2007), StreamPro (in 2006), and Broadband (in 1996) acoustic Doppler current profilers (ADCPs) for streamflow (discharge) measurements made by the USGS. Two new ADCPs, the SonTek M9 and the TRDI RiverRay, were first used in the USGS Water Mission Area programs in 2009. Since 2009, the OSW and USGS Water Science Centers (WSCs) have been conducting field measurements as part of their stream-gaging program using these ADCPs. The purpose of this paper is to document the results of USGS OSW analyses for validation of M9 and RiverRay ADCP streamflow measurements. The OSW required each participating WSC to make comparison measurements over the range of operating conditions in which the instruments were used until sufficient measurements were available. The performance of these ADCPs was evaluated for validation and to identify any present and potential problems. Statistical analyses of streamflow measurements indicate that measurements made with the SonTek M9 ADCP using firmware 2.00–3.00 or the TRDI RiverRay ADCP using firmware 44.12–44.15 are unbiased, and therefore, can continue to be used to make streamflow measurements in the USGS stream-gaging program. However, for the M9 ADCP, there are some important issues to be considered in making future measurements. Possible future work may include additional validation of streamflow measurements made with these instruments from other locations in the United States and measurement validation using updated firmware and software.

  9. Comparison of Temperature Measurements in the Middle Atmosphere by Satellite with Profiles Obtained by Meteorological Rockets

    NASA Technical Reports Server (NTRS)

    Goldberg, Richard A.; Schmidlin, Francis J.; Feofilov, Artem; Bedrick, M.; Rose, R. Lynn

    2012-01-01

    Measurements using the inflatable falling sphere technique have occasionally been used to obtain temperature results from density data and thereby provide comparison with temperature profiles obtained by satellite sounders in the mesosphere and stratosphere. To insure density measurements within narrow time frames and close in space, the inflatable falling sphere is launched within seconds of the nearly overhead satellite pass. Sphere measurements can be used to validate remotely measured temperatures but also have the advantage of measuring small-scale atmospheric features. Even so, with the dearth of remaining falling spheres available (the manufacture of these systems has been discontinued), it may be time to consider whether the remote measurements are mature enough to stand alone. Three field studies are considered, one in 2003 from Northern Sweden, and two in 2010 from the vicinity of Kwajalein Atoll in the South Pacific and from Barking Sands, Hawaii. All three sites are used to compare temperature retrievals between satellite and in situ falling spheres. The major satellite instruments employed are SABER, MLS, and AIRS. The comparisons indicate that remotely measured temperatures mimic the sphere temperature measurements quite well. The data also confirm that satellite retrievals, while not always at the exact location required for detailed studies in space and time, compare sufficiently well to be highly useful. Although the falling sphere will provide a measurement at a specific location and time, satellites only pass a given location daily or less frequently. This report reveals that averaged satellite measurements can provide temperatures and densities comparable to those obtained from the falling sphere, thereby providing a reliable measure of global temperature

  10. Comparison of Temperature Measurements in the Middle Atmosphere by Satellite with Profiles Obtained by Meteorological Rockets

    NASA Astrophysics Data System (ADS)

    Goldberg, R. A.; Schmidlin, F. J.; Feofilov, A. G.; Bedrick, M.; Rose, R. L.

    2012-04-01

    Measurements using the inflatable falling sphere technique have occasionally been used to obtain temperature results from density data and thereby provide comparison with temperature profiles obtained by satellite sounders in the mesosphere and stratosphere. To insure density measurements within narrow time frames and close in space, the inflatable falling sphere is launched within seconds of the nearly overhead satellite pass. Sphere measurements can be used to validate remotely measured temperatures but also have the advantage of measuring small-scale atmospheric features. Even so, with the dearth of remaining falling spheres available (the manufacture of these systems has been discontinued), it may be time to consider whether the remote measurements are mature enough to stand alone. Three field studies are considered, one in 2003 from Northern Sweden, and two in 2010 from the vicinity of Kwajalein Atoll in the South Pacific and from Barking Sands, Hawaii. All three sites are used to compare temperature retrievals between satellite and in situ falling spheres. The major satellite instruments employed are SABER, MLS, and AIRS. The comparisons indicate that remotely measured temperatures mimic the sphere temperature measurements quite well. The data also confirm that satellite retrievals, while not always at the exact location required for detailed studies in space and time, compare sufficiently well to be highly useful. Although the falling sphere will provide a measurement at a specific location and time, satellites only pass a given location daily or less frequently. This report reveals that averaged satellite measurements can provide temperatures and densities comparable to those obtained from the falling sphere, thereby providing a reliable measure of global temperature.

  11. Road Nail: Experimental Solar Powered Intelligent Road Marking System

    NASA Astrophysics Data System (ADS)

    Samardžija, Dragan; Teslić, Nikola; Todorović, Branislav M.; Kovač, Erne; Isailović, Đorđe; Miladinović, Bojan

    2012-03-01

    Driving in low visibility conditions (night time, fog or heavy precipitation) is particularly challenging task with an increased probability of traffic accidents and possible injuries. Road Nail is a solar powered intelligent road marking system of wirelessly networked signaling devices that improve driver safety in low visibility conditions along hazardous roadways. Nails or signaling devices are autonomous nodes with capability to accumulate energy, exchange wireless messages, detect approaching vehicles and emit signalization light. We have built an experimental test-bed that consists of 20 nodes and a cellular gateway. Implementation details of the above system, including extensive measurements and performance evaluations in realistic field deployments are presented. A novel distributed network topology discovery scheme is proposed which integrates both sensor and wireless communication aspects, where nodes act autonomously. Finally, integration of the Road Nail system with the cellular network and the Internet is described.

  12. Stratospheric CH4 and CO2 profiles derived from SCIAMACHY solar occultation measurements

    NASA Astrophysics Data System (ADS)

    Noël, Stefan; Bramstedt, Klaus; Hilker, Michael; Liebing, Patricia; Plieninger, Johannes; Reuter, Max; Rozanov, Alexei; Sioris, Christopher E.; Bovensmann, Heinrich; Burrows, John P.

    2016-04-01

    Stratospheric profiles of methane (CH4) and carbon dioxide (CO2) have been derived from solar occultation measurements of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). The retrieval is performed using a method called onion peeling DOAS (ONPD), which combines an onion peeling approach with a weighting function DOAS (differential optical absorption spectroscopy) fit in the spectral region between 1559 and 1671 nm. By use of updated pointing information and optimisation of the data selection as well as of the retrieval approach, the altitude range for reasonable CH4 could be broadened from 20 to 40 km to about 17 to 45 km. Furthermore, the quality of the derived CO2 has been assessed such that now the first stratospheric profiles (17-45 km) of CO2 from SCIAMACHY are available. Comparisons with independent data sets yield an estimated accuracy of the new SCIAMACHY stratospheric profiles of about 5-10 % for CH4 and 2-3 % for CO2. The accuracy of the products is currently mainly restricted by the appearance of unexpected vertical oscillations in the derived profiles which need further investigation. Using the improved ONPD retrieval, CH4 and CO2 stratospheric data sets covering the whole SCIAMACHY time series (August 2002-April 2012) and the latitudinal range between about 50 and 70° N have been derived. Based on these time series, CH4 and CO2 trends have been estimated. CH4 trends above about 20 km are not significantly different from zero and the trend at 17 km is about 3 ppbv year-1. The derived CO2 trends show a general decrease with altitude with values of about 1.9 ppmv year-1 at 21 km and about 1.3 ppmv year-1 at 39 km. These results are in reasonable agreement with total column trends for these gases. This shows that the new SCIAMACHY data sets can provide valuable information about the stratosphere.

  13. Method for measuring the intensity profile of a CT fan-beam filter

    NASA Astrophysics Data System (ADS)

    Whiting, Bruce R.; Dohatcu, Andreea

    2014-03-01

    Research on CT systems often requires knowledge of intensity as a function of angle in the fan-beam, due to the presence of bowtie filters, for studies such as dose reduction simulation, Monte Carlo dose calculations, or statistical reconstruction algorithms. Since manufacturers consider the x-ray bowtie filter design to be proprietary information, several methods have been proposed to measure the beam intensity profile independently: 1) calculate statistical properties of noise in acquired sinograms (requires access to raw data files, which is also vendor proprietary); 2) measure the waveform of a dosimeter located away from the isocenter (requires dosimeter equipment costing > 10K). We present a novel method that is inexpensive (parts costing 100 from any hardware store, using Gafchromic film at $3 per measurement), requires no proprietary information, and can be performed in a few minutes. A fixture is built from perforated steel tubing, which forms an aperture that selectively samples the intensity at a particular fan-beam angle in a rotating gantry. Two exposures (1× and 2×) are made and self-developing radiochromic film (Gafchromic XR- Ashland Inc.) is then scanned on an inexpensive PC document scanner. An analysis method is described that linearizes the measurements for relative exposure. The resultant profile is corrected for geometric effects (1/LΛ2 fall-off, gantry dwell time) and background exposure, providing a noninvasive estimate of the CT fan-beam intensity present in an operational CT system. This method will allow researchers to conveniently measure parameters required for modeling the effects of bowtie filters in clinical scanners.

  14. Measurements of daytime and upper tropospheric water vapor profiles by Raman lidar

    SciTech Connect

    Bisson, S.E.; Goldsmith, J.E.M.

    1995-03-01

    One of the most important atmospheric constituents needed for climate and meteorological studies is water vapor. Water vapor plays an important role in driving atmospheric circulations through latent heat release and in determining the earth`s radiation budget, both through its radiative effects (water vapor is the major greenhouse gas) and cloud formation. The vertical distribution of water vapor is particularly important because it not only determines convective stability but radiative effects are also strongly altitude dependent. At present, considerable controversy exists over the nature of the vertical redistribution of water vapor in a changing climate, and particularly the distribution of water vapor in the upper troposphere. Understanding upper tropospheric moistening processes such as deep convection are therefore of prime importance in addressing the water vapor feedback question. A powerful, proven technique for the continuous measurement of nighttime water vapor profiles (in clear skies or up to the lowest cloud level) with high spatial and temporal resolution is Raman lidar. As part of the U.S. Department of Energy`s (DOE) Atmospheric Radiation Measurement (ARM) program, a high performance dual field-of-view (fov), narrowband Raman lidar system capable of both daytime and nighttime operation has been developed. In this paper, the Sandia Raman lidar system is discussed along with its application to two problems of current interest: daytime tropospheric water vapor profile measurements and upper tropospheric water vapor. We present recent measurements of upper tropospheric moisture made at the DOE Cloud and Radiation Testbed site (CART) in Oklahoma. Recent daytime measurements are also presented.

  15. A cross-sectional examination of the physical fitness and selected health attributes of recreational all-terrain vehicle riders and off-road motorcyclists.

    PubMed

    Burr, Jamie F; Jamnik, Veronica; Gledhill, Norman

    2010-11-01

    The aims of this study were: (1) to characterize selected fitness and health attributes of two types of habitual recreational off-road vehicle riders - off-road motorcyclists and all-terrain vehicle riders; (2) to explore differences among riders in terms of vehicle type, age, and gender; and (3) to compare the fitness and health of riders to population norms and clinical health standards. Canadian off-road riders (n = 141) of both sexes aged 16 years and over were recruited through local and national off-road riding organizations. Anthropometry, fitness, and health measures of off-road motorcycle and all-terrain vehicle riders were compared with population norms, health standards, and physical activity guidelines. Off-road motorcycle riders had above average aerobic fitness (79th percentile), while all-terrain vehicle riders were lower than average (40th percentile). All riders had a healthy blood lipid profile and a low incidence of the metabolic syndrome (12.9%) compared with members of the general population. Off-road motorcycle riders had healthier body composition and fitness than all-terrain vehicle riders; however, the body composition of off-road motorcycle riders was no healthier than that of the general population and all-terrain vehicle riders were worse than the general population. Off-road motorcycle riders had healthier anthropometry and fitness than all-terrain vehicle riders and thus fewer health risk factors for future disease, demonstrating that the physiological profiles of off-road riders are dependent on vehicle type.

  16. Role of turbulence fluctuations on uncertainties of acoutic Doppler current profiler discharge measurements

    USGS Publications Warehouse

    Tarrab, Leticia; Garcia, Carlos M.; Cantero, Mariano I.; Oberg, Kevin

    2012-01-01

    This work presents a systematic analysis quantifying the role of the presence of turbulence fluctuations on uncertainties (random errors) of acoustic Doppler current profiler (ADCP) discharge measurements from moving platforms. Data sets of three-dimensional flow velocities with high temporal and spatial resolution were generated from direct numerical simulation (DNS) of turbulent open channel flow. Dimensionless functions relating parameters quantifying the uncertainty in discharge measurements due to flow turbulence (relative variance and relative maximum random error) to sampling configuration were developed from the DNS simulations and then validated with field-scale discharge measurements. The validated functions were used to evaluate the role of the presence of flow turbulence fluctuations on uncertainties in ADCP discharge measurements. The results of this work indicate that random errors due to the flow turbulence are significant when: (a) a low number of transects is used for a discharge measurement, and (b) measurements are made in shallow rivers using high boat velocity (short time for the boat to cross a flow turbulence structure).

  17. SUB-M-RAD ANGULAR STABILITY MEASUREMENTS BY USE OF LONG TRACE PROFILER BASED SYSTEMS.

    SciTech Connect

    QIAN,S.

    1999-07-23

    High accuracy angle measurement at the sub-{mu}rad level requires extremely high instrument stability. In order to reach sub-{mu}rad stability (0.1 arc second or less) over long time periods, it is necessary to maintain the test object and almost all of the optical components in the measuring instrument in very steady positions. However, mechanical force relaxation, thermal expansion, and asymmetric structures produce angular and linear displacements in the system resulting in angular measurement error. A Long-Trace-Profiler (LTP)-based stable equipment is used to test precision angular stability with sub-{mu}rad resolution. Long term stability over 15 hours has been measured on different kind of mechanical structures. Temperature monitoring during the tests is extremely important. Some test results showing the effects of thermal variations are presented, which indicate that temperature stability on the order of 0.1 C is absolutely necessary for repeatable sub-{mu}rad measurements. The optical method, using optics with an even number of reflecting surfaces (for example, a right angle prism, pentaprism, or rhomboid prism) to reduce the influence of existing angular displacement, is introduced and the comparison measurement is presented. An optical fiber transfer line is able to reduce the laser angular shift from about 10 {mu}rad to a level of 0.3 {mu}rad rms. Careful system configuration, design and operation are very important for the sub-{mu}rad angle stability.

  18. Form-Profiling of Optics Using the Geometry Measuring Machine and the M-48 CMM at NIST

    PubMed Central

    Machkour-Deshayes, Nadia; Stoup, John; Lu, Z. Q. John; Soons, Johannes; Griesmann, Ulf; Polvani, Robert

    2006-01-01

    We are developing an instrument, the Geometry Measuring Machine (GEMM), to measure the profile errors of aspheric and free form optical surfaces, with measurement uncertainties near 1 nm. Using GEMM, an optical profile is reconstructed from local curvatures of a surface, which are measured at points on the optic’s surface. We will describe a prototype version of GEMM, its repeatability with time, a measurements registry practice, and the calibration practice needed to make nanometer resolution comparisons with other instruments. Over three months, the repeatability of GEMM is 3 nm rms, and is based on the constancy of the measured profile of an elliptical mirror with a radius of curvature of about 83 m. As a demonstration of GEMM’s capabilities for curvature measurement, profiles of that same mirror were measured with GEMM and the NIST Moore M-48 coordinate measuring machine. Although the methods are far different, two reconstructed profiles differ by 22 nm peak-to-valley, or 6 nm rms. This comparability clearly demonstrates that with appropriate calibration, our prototype of the GEMM can measure complex-shaped optics. PMID:27274939

  19. Reflectometry: A Reliable And Sensitive Plasma Diagnostic For Density Profile And Turbulence Measurements On Tore-Supra

    SciTech Connect

    Sabot, R.; Clairet, F.; Giacalone, J. C.; Molina, D.; Sirinelli, A.; Vermare, L.; Heuraux, S.; Leclert, G.

    2006-01-15

    A set of four reflectometers has been installed on Tore-Supra to measure the density profiles and the properties of density fluctuations with good spatial resolution. Fast swept X-mode reflectometers covering the range 50 to 155 GHz provide reliable and accurate measurements of the whole density profile from the edge on the outer side up to the core on the high field side even during large and fast profile evolution. Precise evaluation of the density profile is crucial for particle transport studies. A particular feature, a local peaking, has been observed in the core during ohmic discharge. Density fluctuations are measured with three different techniques. The classical fixed frequency method looks at large scale fluctuations (kr < 3 cm-1) . It measures the radial profile of fluctuations and can detect density perturbation associated to high frequency modes. A new method has been validated to measure the radial profile of small scale density fluctuations from fast FM-CW phase reflected signal. This method could also retrieve the radial wavenumber spectrum. The last method Doppler reflectometry is based on back scattering. It measures the poloidal rotation and fluctuations amplitude at different poloidal wave numbers (3 < k{theta} < 20 cm-1). This collection of diagnostics achieves complementary measurements from the low to the high field side of the discharge and from large to small scale.

  20. On-road emission performance of late-model TWC-cars as measured by remote sensing

    SciTech Connect

    Sjoedin, A. )

    1994-04-01

    During three days in September 1991, the Denver University remote sensor (FEAT) was used to measure the CO and HC emissions from 10,000 gasoline passenger cars on a freeway ramp in Goteborg, Sweden. The data have been used to study the emission performance of late-model three-way catalyst (TWC) cars as a function of age and as compared with earlier model years of non-catalyst cars. Regulations requiring the use of TWCs on all new gasoline passenger cars were adopted in Sweden beginning with model year 1989. Due to sales encouragement, a major fraction of model years 1987 and 1988 are also TWC-cars. The results show that the average volume %CO emissions were approximately 90 percent lower for the model years with exclusively TWC-cars compared to the pre-1987 (non-catalyst) model years. The figure deduced from the remote sensing readings for the corresponding reduction of average volume %HC emissions is uncertain due to liquid water occasionally present in the exhaust of some late-model cars, and interfering with the HC measurements. In the high emission region, no major differences in emission performance were observed between model years with exclusively TWC-cars. 16 refs., 10 figs., 1 tab.

  1. Distribution and sources of air pollutants in the North China Plain based on on-road mobile measurements

    NASA Astrophysics Data System (ADS)

    Zhu, Yi; Zhang, Jiping; Wang, Junxia; Chen, Wenyuan; Han, Yiqun; Ye, Chunxiang; Li, Yingruo; Liu, Jun; Zeng, Limin; Wu, Yusheng; Wang, Xinfeng; Wang, Wenxing; Chen, Jianmin; Zhu, Tong

    2016-10-01

    The North China Plain (NCP) has been experiencing severe air pollution problems with rapid economic growth and urbanisation. Many field and model studies have examined the distribution of air pollutants in the NCP, but convincing results have not been achieved, mainly due to a lack of direct measurements of pollutants over large areas. Here, we employed a mobile laboratory to observe the main air pollutants in a large part of the NCP from 11 June to 15 July 2013. High median concentrations of sulfur dioxide (SO2) (12 ppb), nitrogen oxides (NOx) (NO + NO2; 452 ppb), carbon monoxide (CO) (956 ppb), black carbon (BC; 5.5 µg m-3) and ultrafine particles (28 350 cm-3) were measured. Most of the high values, i.e. 95 percentile concentrations, were distributed near large cities, suggesting the influence of local emissions. In addition, we analysed the regional transport of SO2 and CO, relatively long-lived pollutants, based on our mobile observations together with wind field and satellite data analyses. Our results suggested that, for border areas of the NCP, wind from outside this area would have a diluting effect on pollutants, while south winds would bring in pollutants that have accumulated during transport through other parts of the NCP. For the central NCP, the concentrations of pollutants were likely to remain at high levels, partly due to the influence of regional transport by prevalent south-north winds over the NCP and partly by local emissions.

  2. Prediction of RF-EMF exposure levels in large outdoor areas through car-mounted measurements on the enveloping roads.

    PubMed

    Aerts, Sam; Joseph, Wout; Maslanyj, Myron; Addison, Darren; Mee, Terry; Colussi, Loek; Kamer, Jos; Bolte, John

    2016-09-01

    Knowledge of spatial and temporal trends in the environmental exposure to radiofrequency electromagnetic fields (RF-EMF) is a key prerequisite for RF-EMF risk assessment studies attempting to establish a link between RF-EMF and potential effects on human health as well as on fauna and flora. In this paper, we determined the validity of RF exposure modelling based on inner-area kriging interpolation of measurements on the surrounding streets. The results vary depending on area size and shape and structural factors; a Spearman coefficient of 0.8 and a relative error of less than 3.5dB are achieved on a data set featuring a closed measurement ring around a decently sized area (1km(2), with an average minimum distance of the encircled area to the ring of less than 100m), containing mainly low, detached buildings. In larger areas, additional inner-area sampling is advised, lowering the average minimum distance between sampled and interpolated locations to 100m, to achieve the same level of accuracy. PMID:27364986

  3. Automatic tuning of Bragg condition in a Radio-Acoustic System for PBL temperature profile measurement

    NASA Astrophysics Data System (ADS)

    Bonino, G.; Trivero, P.

    A Radio-Acoustic Sounding System (RASS) with acoustic wavelength λa ~ 1 m was designed and successfully tested. The system proved to be capable of measuring the vertical temperature profile in the Planetary Boundary Layer (PBL) with an accuracy and vertical resolution comparable to that of traditional apparatus (radiothermosondes borne by tethered or disposable balloons, thermosondes borne by aircraft and so on), yet combined with the advantages typical of remote sensing techniques. Up to the summer of 1983 the system needed attendance by an operator who had to identify the acoustic sounding frequency affording the fundamental condition of Bragg resonance between acoustic and radio wavelengths. Features and performance of the new completely automatic RASS arrangement are presented. These include the possibility of obtaining average thermal vertical profiles at preset time intervals. Maximum range of measurements obtained in about 1000 1/2-h averages was: in 90% of cases ⩾ 600m; in 50% of cases ⩾ 1100m. Such results indicate the usefulness of automatic RASS as a tool for meteorological purposes and for the application of air pollution control strategies.

  4. First density profile measurements using frequency modulation of the continuous wave reflectometry on JET.

    PubMed

    Meneses, L; Cupido, L; Sirinelli, A; Manso, M E

    2008-10-01

    We present the main design options and implementation of an X-mode reflectometer developed and successfully installed at JET using an innovative approach. It aims to prove the viability of measuring density profiles with high spatial and temporal resolution using broadband reflectometry operating in long and complex transmission lines. It probes the plasma with magnetic fields between 2.4 and 3.0 T using the V band [approximately (0-1.4)x10(19) m(-3)]. The first experimental results show the high sensitivity of the diagnostic when measuring changes in the plasma density profile occurring ITER relevant regimes, such as ELMy H-modes. The successful demonstration of this concept motivated the upgrade of the JET frequency modulation of the continuous wave (FMCW) reflectometry diagnostic, to probe both the edge and core. This new system is essential to prove the viability of using the FMCW reflectometry technique to probe the plasma in next step devices, such as ITER, since they share the same waveguide complexity. PMID:19068528

  5. Validation of the survey of work styles: a profile measure of the type A behaviour pattern.

    PubMed

    Gray, A; Jackson, D N; Howard, J H

    1989-01-01

    The present study compares the Type A classification accuracy of the Jenkins Activity Survey (JAS), The Framingham Type A Scale, and a new Type A behaviour pattern (TABP) measure. The Survey of Work Styles (SWS), a self-report measure of the TABP, was developed using a construct approach to scale construction. It consists of six content scales. Impatience, Anger, Work Involvement, Time Urgency, Job Dissatisfaction and Competitiveness. In addition to the six content scales, a seventh scale, Scale A, is comprised of items empirically selected to relate to the Rosenman Structured Interview. In the present study the SWS was found to be significantly related to both the JAS, and the Framingham Type A Scale in a sample of 163 business managers. Median reliability of the SWS subscales was 0.82, and for the total scale 0.90. Discriminant function analysis using cross validational jackknifing procedures resulted in a classification accuracy of 83% of the Type A managers in relation to the Structured Interview. Classification using the SWS was found to correlate significantly higher with the Structured Interview than did either classification with the JAS or with the Framingham Type A Scale. Modal profile analysis yielded three independent bipolar typal dimensions, indicating that a single dimension or classification of the TABP represents an oversimplification of a complex behaviour pattern. These results support the reconceptualization of the TABP in terms of distinct facets and profile patterns. PMID:2709081

  6. Measurements of Stratospheric Pinatubo Aerosol Extinction Profiles by a Raman Lidar

    NASA Technical Reports Server (NTRS)

    Abo, Makoto; Nagasawa, Chikao

    1992-01-01

    The Raman lidar has been used for remote measurements of water vapor, ozone and atmospheric temperature in the lower troposphere because the Raman cross section is three orders smaller than the Rayleigh cross section. We estimated the extinction coefficients of the Pinatubo volcanic aerosol in the stratosphere using a Raman lidar. If the precise aerosol extinction coefficients are derived, the backscatter coefficient of a Mie scattering lidar will be more accurately estimated. The Raman lidar has performed to measure density profiles of some species using Raman scattering. Here we used a frequency-doubled Nd:YAG laser for transmitter and received nitrogen vibrational Q-branch Raman scattering signal. Ansmann et al. (1990) derived tropospherical aerosol extinction profiles with a Raman lidar. We think that this method can apply to dense stratospheric aerosols such as Pinatubo volcanic aerosols. As dense aerosols are now accumulated in the stratosphere by Pinatubo volcanic eruption, the error of Ramen lidar signal regarding the fluctuation of air density can be ignored.

  7. Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration

    SciTech Connect

    Rodney Frehlich

    2012-10-30

    New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

  8. Dial Measurements of Free-Tropospheric Ozone Profiles in Huntsville, AL

    NASA Technical Reports Server (NTRS)

    Newchurch, Mike; Kuang, Shi; Burris, John; Johnson, Steve; Long, Stephanie

    2008-01-01

    A tropospheric ozone DIfferential Absorption Lidar (DIAL) system has been developed jointly by NASA and the University of Alabama at Huntsville (UAH). Two separated Nd:YAG pumped dye laser systems produce the laser pulses with wavelengths of 285 and 291 nm at 20 Hz frequency. The receiver is a Newtonian telescope with a 40 cm primary and a two-channel aft optics unit. The detection system currently uses photon counting to facilitate operations at the maximum achievable altitude. This lidar measures free-tropospheric ozone profiles between 4-10 km at Regional Atmospheric Profiling Laboratory for Discovery (RAPCD) in UAH campus (ASL 206 m) under both daytime and nighttime conditions. Frequent coincident ozonesonde flights and theoretical calculations provide evidence to indicate the retrieval accuracy ranges from approx.5% at 4 km to approx.60% at 10 km with 750-m vertical resolution and 30-minute integration. Three Hamamatsu 7400 PMTs and analog detection technique will be added on the current system to extend the measurement to approx.100 m above ground to monitor the PBL and lower tropospheric ozone variations.

  9. Measured and modeled HOCl profiles in the mid-latitude stratosphere : implication for ozone loss

    NASA Technical Reports Server (NTRS)

    Kovalenko, L. J.; Salawitch, R. J.; Blavier, J. -F.; Sen, B.; Toon, G. C.; Jucks, K. W.; Johnson, D. G.; Stachnik, R. A.; Margitan, J. J.

    2004-01-01

    The HOCl catalytic cycle is an efficient ozone loss mechanism in the lower mid-latitude stratosphere. We use a diurnal steady-state photochemical model to calculate profiles of HOCl for conditions encountered by a number of high-altitude balloon flights. To assess how well this model represents ozone loss by the HOCl cycle, we compare our calculations of HOCl and its precursors Cl0 and HO2 with measurements obtained by an FTIR solar absorption spectrometer (MkIV), a far-infrared emission spectrometer (FIRS-2), and a submillimetenvave limb sounder (SLS). We then evaluate these comparisons in light of a number of recent laboratory studies of the main formation mechanism of HOCl, the reaction of Cl0 + HO2. Those studies measured both the reaction rate constant and the quantum yield for a second product pathway, formation of HCl.

  10. Topographic measurements of supersmooth dielectric films made with a mechanical profiler and a scanning force microscope

    NASA Astrophysics Data System (ADS)

    Bennett, Jean M.; Tehrani, Mohammad M.; Jahanmir, Jay; Podlesny, John C.; Balter, Tami L.

    1995-01-01

    The roughnesses of five supersmooth dielectric films of Si3N4, TiO2 , HfO2, Ta2O5 , and Al2O3 prepared by an ion-beam-sputtering technique were measured with a commercial Talystep mechanical profiler and a sensitive Leica WYKO SPM30 scanning force microscope (SFM) to determine how much roughness the films added to the approximately 1-A-rms roughness fused-silica substrates on which they were deposited. In all cases the increase in roughness for the three-quarter-wave optical thickness films was a small fraction of an angstrom. SFM measurements showed that the topography of the Ta2O5 and Al2O3 films was less random than that of the other film materials and the substrates.

  11. Direct measurement of relative permeability in rocks from unsteady-state saturation profiles

    NASA Astrophysics Data System (ADS)

    Kianinejad, Amir; Chen, Xiongyu; DiCarlo, David A.

    2016-08-01

    We develop a method to measure liquid relative permeability in rocks directly from transient in situ saturation profiles during gravity drainage experiments. Previously, similar methods have been used for sandpacks; here, this method is extended to rocks by applying a slight overpressure of gas at the inlet. Relative permeabilities are obtained in a 60 cm long vertical Berea sandstone core during gravity drainage, directly from the measured unsteady-state in situ saturations along the core at different times. It is shown that for obtaining relative permeability using this method, if certain criteria are met, the capillary pressure of the rock can be neglected. However, it is essential to use a correct gas pressure gradient along the core. This involves incorporating the pressure drop at the outlet of the core due to capillary discontinuity effects. The method developed in this work obtains relative permeabilities in unsteady-state fashion over a wide range of saturations quickly and accurately.

  12. Fast Thermal Helium Beam diagnostic for measurements of edge electron profiles and fluctuations

    SciTech Connect

    Agostini, M. Scarin, P.; Cavazzana, R.; Carraro, L.; Grando, L.; Taliercio, C.; Franchin, L.; Tiso, A.

    2015-12-15

    The edge of fusion experiments is a region where strong gradients develop, together with the presence of strong fluctuations due to turbulence. The thermal helium beam diagnostic developed for the RFX-mod experiment allows the measurements with a single diagnostic of both low frequency time evolution of the edge radial profiles of electron density and temperature (tens of hertz), and the high frequency fluctuations (hundreds of kHz). To maximize the collected light, the three HeI lines necessary to be measured for the evaluation of n{sub e} and T{sub e} are separated with a spectrograph, and multianode photomultipliers are used as light detectors. The paper describes the diagnostic setup, with the interface hardware with the machine and the optical layout, and the characterization of its performances.

  13. Fast Thermal Helium Beam diagnostic for measurements of edge electron profiles and fluctuations.

    PubMed

    Agostini, M; Scarin, P; Cavazzana, R; Carraro, L; Grando, L; Taliercio, C; Franchin, L; Tiso, A

    2015-12-01

    The edge of fusion experiments is a region where strong gradients develop, together with the presence of strong fluctuations due to turbulence. The thermal helium beam diagnostic developed for the RFX-mod experiment allows the measurements with a single diagnostic of both low frequency time evolution of the edge radial profiles of electron density and temperature (tens of hertz), and the high frequency fluctuations (hundreds of kHz). To maximize the collected light, the three HeI lines necessary to be measured for the evaluation of n(e) and T(e) are separated with a spectrograph, and multianode photomultipliers are used as light detectors. The paper describes the diagnostic setup, with the interface hardware with the machine and the optical layout, and the characterization of its performances. PMID:26724033

  14. Measurements of Spatial Line Emission Profiles in the Main Scrape-Off Layer of the DIII-D Tokamak

    SciTech Connect

    Groth, M; Ellis, R; Brooks, N; Fenstermacher, M; Lasnier, C; Meyer, W; Moller, J

    2009-06-05

    A video camera system is described that measures the spatial distribution of visible line emission emitted from the main scrape-off layer (SOL) of plasmas in the DIII-D tokamak. A wide-angle lens installed on an equatorial port and an in-vessel mirror which intercepts part of the lens view provide simultaneous tangential views of the SOL on the low-field and high-field sides of the plasma's equatorial plane. Tomographic reconstruction techniques are used to calculate the 2-D poloidal profiles from the raw data, and 1-D poloidal profiles simulating chordal views of other optical diagnostics from the 2-D profiles. The 2-D profiles can be compared with SOL plasma simulations; the 1-D profiles with measurements from spectroscopic diagnostics. Sample results are presented which elucidate carbon transport in plasmas with toroidally uniform injection of methane and argon transport in disruption mitigation experiments with massive gas jet injection.

  15. Field evaluation of shallow-water acoustic doppler current profiler discharge measurements

    USGS Publications Warehouse

    Rehmel, M.S.

    2007-01-01

    In 2004, the U.S. Geological Survey (USGS) Office of Surface Water staff and USGS Water Science employees began testing the StreamPro, an acoustic Doppler current profiler (ADCP) for shallow-water discharge measurements. Teledyne RD Instruments introduced the StreamPro in December of 2003. The StreamPro is designed to make a "moving boat" discharge measurement in streams with depths between 0.15 and 2 m. If the StreamPro works reliably in these conditions, it will allow for use of ADCPs in a greater number of streams than previously possible. Evaluation sites were chosen to test the StreamPro over a range of conditions. Simultaneous discharge measurements with mechanical and other acoustic meters, along with stable rating curves at established USGS streamflow-gaging stations, were used for comparisons. The StreamPro measurements ranged in mean velocity from 0.076 to 1.04 m/s and in discharge from 0.083 m 3/s to 43.4 m 3/s. Tests indicate that discharges measured with the StreamPro compare favorably to the discharges measured with the other meters when the mean channel velocity is greater than 0.25 m/s. When the mean channel velocity is less than 0.25 m/s, the StreamPro discharge measurements for individual transects have greater variability than those StreamPro measurements where the mean channel velocity is greater than 0.25 m/s. Despite this greater variation in individual transects, there is no indication that the StreamPro measured discharges (the mean discharge for all transects) are biased, provided that enough transects are used to determine the mean discharge. ?? 2007 ASCE.

  16. Profile measurement of concave spherical mirror and a flat mirror using a high-speed nanoprofiler

    PubMed Central

    2013-01-01

    Ultraprecise aspheric mirrors that offer nanofocusing and high coherence are indispensable for developing third-generation synchrotron radiation and X-ray free-electron laser sources. In industry, the extreme ultraviolet (wavelength: 13.5 nm) lithography used for high-accuracy aspheric mirrors is a promising technology for fabricating semiconductor devices. In addition, ultraprecise mirrors with a radius of curvature of less than 10 mm are needed in many digital video instruments. We developed a new type of nanoprofiler that traces the normal vector of a mirror's surface. The principle of our measuring method is that the normal vector at each point on the surface is determined by making the incident light beam on the mirror surface and the reflected beam at that point coincide, using two sets of two pairs of goniometers and one linear stage. From the acquired normal vectors and their coordinates, the three-dimensional shape is calculated by a reconstruction algorithm. The characteristics of the measuring method are as follows: the profiler uses the straightness of laser light without using a reference surface. Surfaces of any shape can be measured, and there is no limit on the aperture size. We calibrated this nanoprofiler by considering the system error resulting from the assembly error and encoder scale error, and evaluated the performance at the nanometer scale. We suppressed the effect of random errors by maintaining the temperature in a constant-temperature room within ±0.01°C. We measured a concave spherical mirror with a radius of curvature of 400 mm and a flat mirror and compared the results with those obtained using a Fizeau interferometer. The profiles of the mirrors were consistent within the range of system errors. PMID:23680514

  17. Correlation Between Immersion Profile and Measured Value of Fixed-Point Temperature

    NASA Astrophysics Data System (ADS)

    Shulgat, O. S.; Fuksov, V. M.; Ivanova, A. G.; Gerasimov, S. F.; Pokhodun, A. I.

    2014-04-01

    Assessment of thermal immersion effects in the melting and freezing points defined by the International Temperature Scale of 1990 is one of the vital issues of modern thermometry. In documents of the Consultative Committee for Thermometry, the deviation of the experimental immersion profile from the theoretical value of the hydrostatic effect at a height of about 3 cm to 5 cm from the thermometer well bottom is used for the estimation of the uncertainty due to unwanted thermal effects. This estimation assumes the occurrence of solely the hydrostatic effect all along the height of the well inner wall. Real distortions of the temperature gradient at the bottom and at the top part of the well caused by the change of heat-exchange conditions are not taken into account. To define more precisely the temperature gradient along the height of the well, a miniature PRT with a 30 mm sensitive element and a sheath length and diameter of about 60 mm and 6 mm, respectively, were used. Also, the measurements of fixed-points temperature at noticeably different slopes of immersion profiles due to variations of the thermometer heat exchange and phase transition realization conditions were produced by means of a standard platinum resistance thermometer (SPRT). The measurements were carried out at the tin and zinc freezing points. The immersion curves measured with a miniature thermometer demonstrated an increase of the temperature during its lifting in the first 1 cm to 3 cm above the bottom of the well. The measurement results at the zinc freezing point by means of the SPRT have not confirmed the correlation between the immersion curves, the received value of the Zn freezing temperature, and the estimation of its uncertainty.

  18. A LOFAR census of non-recycled pulsars: average profiles, dispersion measures, flux densities, and spectra

    NASA Astrophysics Data System (ADS)

    Bilous, A. V.; Kondratiev, V. I.; Kramer, M.; Keane, E. F.; Hessels, J. W. T.; Stappers, B. W.; Malofeev, V. M.; Sobey, C.; Breton, R. P.; Cooper, S.; Falcke, H.; Karastergiou, A.; Michilli, D.; Osłowski, S.; Sanidas, S.; ter Veen, S.; van Leeuwen, J.; Verbiest, J. P. W.; Weltevrede, P.; Zarka, P.; Grießmeier, J.-M.; Serylak, M.; Bell, M. E.; Broderick, J. W.; Eislöffel, J.; Markoff, S.; Rowlinson, A.

    2016-06-01

    We present first results from a LOFAR census of non-recycled pulsars. The census includes almost all such pulsars known (194 sources) at declinations Dec > 8° and Galactic latitudes |Gb| > 3°, regardless of their expected flux densities and scattering times. Each pulsar was observed for ≥20 min in the contiguous frequency range of 110-188 MHz. Full-Stokes data were recorded. We present the dispersion measures, flux densities, and calibrated total intensity profiles for the 158 pulsars detected in the sample. The median uncertainty in census dispersion measures (1.5 × 10-3 pc cm-3) is ten times smaller, on average, than in the ATNF pulsar catalogue. We combined census flux densities with those in the literature and fitted the resulting broadband spectra with single or broken power-law functions. For 48 census pulsars such fits are being published for the first time. Typically, thechoice between single and broken power-laws, as well as the location of the spectral break, were highly influenced by the spectral coverage of the available flux density measurements. In particular, the inclusion of measurements below 100 MHz appears essential for investigating the low-frequency turnover in the spectra for most of the census pulsars. For several pulsars, we compared the spectral indices from different works and found the typical spread of values to be within 0.5-1.5, suggesting a prevailing underestimation of spectral index errors in the literature. The census observations yielded some unexpected individual source results, as we describe in the paper. Lastly, we will provide this unique sample of wide-band, low-frequency pulse profiles via the European Pulsar Network Database. Tables B.1-B.4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A134

  19. Nighttime E-region Electron Density Profiles Measured During the EQUIS II Campaign at Kwajalein Atoll

    NASA Astrophysics Data System (ADS)

    Rowland, D. E.; Pfaff, R. F.; Fourre, R.; Kudeki, E.; Steigies, C. T.; Chau, K.; Sarango, M.

    2005-05-01

    The EQUIS II nighttime E-region rocket and radar measurements were made in order to improve our understanding of the electrodynamics associated with density gradients, neutral wind shear, and enhanced electric fields that develop post-sunset in the near-equatorial region. Four rocket experiments were launched on two separate nights in September, 2004 from Kwajalein Atoll (9.4° N, 167.5° E), while simultaneous E-region radar observations were made with the ALTAIR radar. The focus of this presentation are the electron density profiles measured by two instrumented rockets as they passed through the unstable region on the upleg and downleg. Each rocket used two Langmuir probes and an impedance probe of a new design to measure both the absolute electron density and small-scale density fluctuations with spatial scales on the order of one meter. The impedance probe returned measurements from 7 kHz to 4 MHz, using a new design that excited the plasma using a pseudo-white-noise generator, allowing for an altitude resolution of approximately 40 meters. These impedance curves allow determination of the electron density from the identification of the upper hybrid frequency. In addition, evidence is presented that the impedance probe observed the lower-frequency "series" resonance which is dependent on the electron temperature. Data from the Langmuir probes, a beacon experiment, and the impedance probe are compared and the resulting density profiles are examined to estimate their contribution to the observed electric field irregularities via the gradient-drift and other instabilities.

  20. Technical Note: Influence of Compton currents on profile measurements in small-volume ion chambers

    SciTech Connect

    Tanny, Sean; Sperling, Nicholas; Parsai, E. Ishmael; Holmes, Shannon

    2015-10-15

    Purpose: This work is to evaluate the effects of Compton current generation in three small-volume ionization chambers on measured beam characteristics for electron fields. Methods: Beam scans were performed using Exradin A16, A26, and PTW 31014 microchambers. Scans with varying chamber components shielded were performed. Static point measurements, output factors, and cable only irradiations were performed to determine the contribution of Compton currents to various components of the chamber. Monte Carlo simulations were performed to evaluate why one microchamber showed a significant reduction in Compton current generation. Results: Beam profiles demonstrated significant distortion for two of the three chambers when scanned parallel to the chamber axis, produced by electron deposition within the wire. Measurements of ionization produced within the cable identified Compton current generation as the cause of these distortions. The size of the central collecting wire was found to have the greatest influence on the magnitude of Compton current generation. Conclusions: Microchambers can demonstrate significant (>5%) deviations from properties as measured with larger volume chambers (0.125 cm{sup 3} and above). These deviations can be substantially reduced by averaging measurements conducted at opposite polarities.

  1. Retrieving moisture profiles from precipitable water measurements using a variational data assimilation approach

    SciTech Connect

    Guo, Y.R.; Zou, X.; Kuo, Y.H.

    1996-04-01

    Atmospheric moisture distribution is directly related to the formation of clouds and precipitation and affects the atmospheric radiation and climate. Currently, several remote sensing systems can measure precipitable water (PW) with fairly high accuracy. As part of the development of an Integrated Data Assimilation and Sounding System in support of the Atmospheric Radiation Measurement Program, retrieving the 3-D water vapor fields from PW measurements is an important problem. A new four dimensional variational (4DVAR) data assimilation system based on the Penn State/National Center for Atmospheric Research (NCAR) mesoscale model (MM5) has been developed by Zou et al. (1995) with the adjoint technique. In this study, we used this 4DVAR system to retrieve the moisture profiles. Because we do not have a set of real observed PW measurements now, the special soundings collected during the Severe Environmental Storm and Mesoscale Experiment (SESAME) in 1979 were used to simulate a set of PW measurements, which were then assimilated into the 4DVAR system. The accuracy of the derived water vapor fields was assessed by direct comparison with the detailed specific humidity soundings. The impact of PW assimilation on precipitation forecast was examined by conducting a series of model forecast experiments started from the different initial conditions with or without data assimilation.

  2. Errors in acoustic doppler profiler velocity measurements caused by flow disturbance

    USGS Publications Warehouse

    Mueller, D.S.; Abad, J.D.; Garcia, C.M.; Gartner, J.W.; Garcia, M.H.; Oberg, K.A.

    2007-01-01

    Acoustic Doppler current profilers (ADCPs) are commonly used to measure streamflow and water velocities in rivers and streams. This paper presents laboratory, field, and numerical model evidence of errors in ADCP measurements caused by flow disturbance. A state-of-the-art three-dimensional computational fluid dynamic model is validated with and used to complement field and laboratory observations of flow disturbance and its effect on measured velocities. Results show that near the instrument, flow velocities measured by the ADCP are neither the undisturbed stream velocity nor the velocity of the flow field around the ADCP. The velocities measured by the ADCP are biased low due to the downward flow near the upstream face of the ADCP and upward recovering flow in the path of downstream transducer, which violate the flow homogeneity assumption used to transform beam velocities into Cartesian velocity components. The magnitude of the bias is dependent on the deployment configuration, the diameter of the instrument, and the approach velocity, and was observed to range from more than 25% at 5cm from the transducers to less than 1% at about 50cm from the transducers for the scenarios simulated. ?? 2007 ASCE.

  3. Evaluating the road safety effects of a fuel cost increase measure by means of zonal crash prediction modeling.

    PubMed

    Pirdavani, Ali; Brijs, Tom; Bellemans, Tom; Kochan, Bruno; Wets, Geert

    2013-01-01

    Travel demand management (TDM) consists of a variety of policy measures that affect the transportation system's effectiveness by changing travel behavior. The primary objective to implement such TDM strategies is not to improve traffic safety, although their impact on traffic safety should not be neglected. The main purpose of this study is to evaluate the traffic safety impact of conducting a fuel-cost increase scenario (i.e. increasing the fuel price by 20%) in Flanders, Belgium. Since TDM strategies are usually conducted at an aggregate level, crash prediction models (CPMs) should also be developed at a geographically aggregated level. Therefore zonal crash prediction models (ZCPMs) are considered to present the association between observed crashes in each zone and a set of predictor variables. To this end, an activity-based transportation model framework is applied to produce exposure metrics which will be used in prediction models. This allows us to conduct a more detailed and reliable assessment while TDM strategies are inherently modeled in the activity-based models unlike traditional models in which the impact of TDM strategies are assumed. The crash data used in this study consist of fatal and injury crashes observed between 2004 and 2007. The network and socio-demographic variables are also collected from other sources. In this study, different ZCPMs are developed to predict the number of injury crashes (NOCs) (disaggregated by different severity levels and crash types) for both the null and the fuel-cost increase scenario. The results show a considerable traffic safety benefit of conducting the fuel-cost increase scenario apart from its impact on the reduction of the total vehicle kilometers traveled (VKT). A 20% increase in fuel price is predicted to reduce the annual VKT by 5.02 billion (11.57% of the total annual VKT in Flanders), which causes the total NOCs to decline by 2.83%. PMID:23200453

  4. Long-term exposure to fine particulate matter, residential proximity to major roads and measures of brain structure

    PubMed Central

    Wilker, Elissa H.; Preis, Sarah R.; Beiser, Alexa S.; Wolf, Philip A.; Au, Rhoda; Kloog, Itai; Li, Wenyuan; Schwartz, Joel; Koutrakis, Petros; DeCarli, Charles; Seshadri, Sudha; Mittleman, Murray A.

    2015-01-01

    Background and Purpose Long-term exposure to ambient air pollution is associated with cerebrovascular disease and cognitive impairment, but whether it is related to structural changes in the brain is not clear. We examined the associations between residential long-term exposure to ambient air pollution and markers of brain aging using magnetic resonance imaging (MRI). Methods Framingham Offspring Study participants who attended the seventh examination, were at least 60 years old and free of dementia and stroke were included. We evaluated associations between exposures (fine particulate matter (PM2.5) and residential proximity to major roadways) and measures of total cerebral brain volume, hippocampal volume, white matter hyperintensity volume (log-transformed and extensive white matter hyperintensity volume for age) and covert brain infarcts. Models were adjusted for age, clinical covariates, indicators of socioeconomic position, and temporal trends. Results A 2 μg/m3 increase in PM2.5 was associated with -0.32% (95%CI: -0.59, -0.05) smaller total cerebral brain volume and 1.46 (95%CI: 1.10, 1.94) higher odds of covert brain infarcts. Living further away from a major roadway was associated with 0.10 (95%CI: 0.01, 0.19) greater log-transformed white matter hyperintensity volume for an interquartile range difference in distance, but no clear pattern of association was observed for extensive white matter. Conclusions Exposure to elevated levels of PM2.5 was associated with smaller total cerebral brain volume, a marker of age-associated brain atrophy, and with higher odds of covert brain infarcts. These findings suggest that air pollution is associated with insidious effects on structural brain aging even in dementia-and stroke-free persons. PMID:25908455

  5. On-road measurement of regulated pollutants from diesel and CNG buses with urea selective catalytic reduction systems

    NASA Astrophysics Data System (ADS)

    Guo, Jiadong; Ge, Yunshan; Hao, Lijun; Tan, Jianwei; Li, Jiaqiang; Feng, Xiangyu

    2014-12-01

    In this study, emissions from 13 buses operated in Beijing, including two Euro-III diesel buses, four Euro-IV diesel buses, three Euro-V diesel buses and four Euro-V CNG buses, were characterized in real world conditions. All of the buses tested were fitted with selective catalytic reduction (SCR) systems except for the Euro-III diesel buses. A SEMTECH-DS was used for testing the gaseous pollutants, and an electric low pressure impactor (ELPI) was used for measuring of particle numbers and size distributions. A comparison was made based on emission performance of these buses by employing the VSP approach and fuel- based emissions factors. Diesel buses emitted less CO and THC but more NOx and PM pollutants than CNG buses. The NOx reduction efficiencies of the SCR systems for CNG buses were higher because of the high exhaust temperature and high NO2/NOx ratio, whereas the efficiencies for diesel buses were lower. This resulted in extremely low NOx emissions from CNG buses, but the high NO2/NOx ratio needs further study. Failures of urea injection in the SCR systems were detected in this research, which resulted in very high NOx emissions. The CNG buses also emitted smaller numbers of particles and less particle mass with the presence of oxidation catalysts. Diesel buses satisfying the Euro-V standard performed better than Euro-IV and Euro-III diesel buses in terms of emission performance, except for more nuclei mode particles. Most of time, the Euro-IV diesel buses show no advantages in CO and NOx emissions compared with the Euro-III diesel buses.

  6. Evaluating the road safety effects of a fuel cost increase measure by means of zonal crash prediction modeling.

    PubMed

    Pirdavani, Ali; Brijs, Tom; Bellemans, Tom; Kochan, Bruno; Wets, Geert

    2013-01-01

    Travel demand management (TDM) consists of a variety of policy measures that affect the transportation system's effectiveness by changing travel behavior. The primary objective to implement such TDM strategies is not to improve traffic safety, although their impact on traffic safety should not be neglected. The main purpose of this study is to evaluate the traffic safety impact of conducting a fuel-cost increase scenario (i.e. increasing the fuel price by 20%) in Flanders, Belgium. Since TDM strategies are usually conducted at an aggregate level, crash prediction models (CPMs) should also be developed at a geographically aggregated level. Therefore zonal crash prediction models (ZCPMs) are considered to present the association between observed crashes in each zone and a set of predictor variables. To this end, an activity-based transportation model framework is applied to produce exposure metrics which will be used in prediction models. This allows us to conduct a more detailed and reliable assessment while TDM strategies are inherently modeled in the activity-based models unlike traditional models in which the impact of TDM strategies are assumed. The crash data used in this study consist of fatal and injury crashes observed between 2004 and 2007. The network and socio-demographic variables are also collected from other sources. In this study, different ZCPMs are developed to predict the number of injury crashes (NOCs) (disaggregated by different severity levels and crash types) for both the null and the fuel-cost increase scenario. The results show a considerable traffic safety benefit of conducting the fuel-cost increase scenario apart from its impact on the reduction of the total vehicle kilometers traveled (VKT). A 20% increase in fuel price is predicted to reduce the annual VKT by 5.02 billion (11.57% of the total annual VKT in Flanders), which causes the total NOCs to decline by 2.83%.

  7. Modeling road-cycling performance.

    PubMed

    Olds, T S; Norton, K I; Lowe, E L; Olive, S; Reay, F; Ly, S

    1995-04-01

    This paper presents a complete set of equations for a "first principles" mathematical model of road-cycling performance, including corrections for the effect of winds, tire pressure and wheel radius, altitude, relative humidity, rotational kinetic energy, drafting, and changed drag. The relevant physiological, biophysical, and environmental variables were measured in 41 experienced cyclists completing a 26-km road time trial. The correlation between actual and predicted times was 0.89 (P < or = 0.0001), with a mean difference of 0.74 min (1.73% of mean performance time) and a mean absolute difference of 1.65 min (3.87%). Multiple simulations were performed where model inputs were randomly varied using a normal distribution about the measured values with a SD equivalent to the estimated day-to-day variability or technical error of measurement in each of the inputs. This analysis yielded 95% confidence limits for the predicted times. The model suggests that the main physiological factors contributing to road-cycling performance are maximal O2 consumption, fractional utilization of maximal O2 consumption, mechanical efficiency, and projected frontal area. The model is then applied to some practical problems in road cycling: the effect of drafting, the advantage of using smaller front wheels, the effects of added mass, the importance of rotational kinetic energy, the effect of changes in drag due to changes in bicycle configuration, the normalization of performances under different conditions, and the limits of human performance. PMID:7615475

  8. CLASH-X: A comparison of lensing and X-ray techniques for measuring the mass profiles of galaxy clusters

    SciTech Connect

    Donahue, Megan; Voit, G. Mark; Hoffer, Aaron; Baldi, Alessandro; Mahdavi, Andisheh; Umetsu, Keiichi; Czakon, Nicole; Ettori, Stefano; Postman, Marc; Coe, Dan; Bradley, Larry; Bartelmann, Mattias; Benitez, Narciso; Broadhurst, Tom; Ford, Holland; Gastaldello, Fabio; Grillo, Claudio; Infante, Leopoldo; and others

    2014-10-20

    We present profiles of temperature, gas mass, and hydrostatic mass estimated from new and archival X-ray observations of CLASH clusters. We compare measurements derived from XMM and Chandra observations with one another and compare both to gravitational lensing mass profiles derived with CLASH Hubble Space Telescope and Subaru Telescope lensing data. Radial profiles of Chandra and XMM measurements of electron density and enclosed gas mass are nearly identical, indicating that differences in hydrostatic masses inferred from X-ray observations arise from differences in gas-temperature measurements. Encouragingly, gas temperatures measured in clusters by XMM and Chandra are consistent with one another at ∼100-200 kpc radii, but XMM temperatures systematically decline relative to Chandra temperatures at larger radii. The angular dependence of the discrepancy suggests that additional investigation on systematics such as the XMM point-spread function correction, vignetting, and off-axis responses is yet required. We present the CLASH-X mass-profile comparisons in the form of cosmology-independent and redshift-independent circular-velocity profiles. We argue that comparisons of circular-velocity profiles are the most robust way to assess mass bias. Ratios of Chandra hydrostatic equilibrium (HSE) mass profiles to CLASH lensing profiles show no obvious radial dependence in the 0.3-0.8 Mpc range. However, the mean mass biases inferred from the weak-lensing (WL) and SaWLens data are different. As an example, the weighted-mean value at 0.5 Mpc is (b) = 0.12 for the WL comparison and (b) = –0.11 for the SaWLens comparison. The ratios of XMM HSE mass profiles to CLASH lensing profiles show a pronounced radial dependence in the 0.3-1.0 Mpc range, with a weighted mean mass bias value rising to (b) ≳ 0.3 at ∼1 Mpc for the WL comparison and (b) ≈ 0.25 for the SaWLens comparison. The enclosed gas mass profiles from both Chandra and XMM rise to a value ≈1/8 times the total

  9. CLASH-X: A Comparison of Lensing and X-Ray Techniques for Measuring the Mass Profiles of Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Donahue, Megan; Voit, G. Mark; Mahdavi, Andisheh; Umetsu, Keiichi; Ettori, Stefano; Merten, Julian; Postman, Marc; Hoffer, Aaron; Baldi, Alessandro; Coe, Dan; Czakon, Nicole; Bartelmann, Mattias; Benitez, Narciso; Bouwens, Rychard; Bradley, Larry; Broadhurst, Tom; Ford, Holland; Gastaldello, Fabio; Grillo, Claudio; Infante, Leopoldo; Jouvel, Stephanie; Koekemoer, Anton; Kelson, Daniel; Lahav, Ofer; Lemze, Doron; Medezinski, Elinor; Melchior, Peter; Meneghetti, Massimo; Molino, Alberto; Moustakas, John; Moustakas, Leonidas A.; Nonino, Mario; Rosati, Piero; Sayers, Jack; Seitz, Stella; Van der Wel, Arjen; Zheng, Wei; Zitrin, Adi

    2014-10-01

    We present profiles of temperature, gas mass, and hydrostatic mass estimated from new and archival X-ray observations of CLASH clusters. We compare measurements derived from XMM and Chandra observations with one another and compare both to gravitational lensing mass profiles derived with CLASH Hubble Space Telescope and Subaru Telescope lensing data. Radial profiles of Chandra and XMM measurements of electron density and enclosed gas mass are nearly identical, indicating that differences in hydrostatic masses inferred from X-ray observations arise from differences in gas-temperature measurements. Encouragingly, gas temperatures measured in clusters by XMM and Chandra are consistent with one another at ~100-200 kpc radii, but XMM temperatures systematically decline relative to Chandra temperatures at larger radii. The angular dependence of the discrepancy suggests that additional investigation on systematics such as the XMM point-spread function correction, vignetting, and off-axis responses is yet required. We present the CLASH-X mass-profile comparisons in the form of cosmology-independent and redshift-independent circular-velocity profiles. We argue that comparisons of circular-velocity profiles are the most robust way to assess mass bias. Ratios of Chandra hydrostatic equilibrium (HSE) mass profiles to CLASH lensing profiles show no obvious radial dependence in the 0.3-0.8 Mpc range. However, the mean mass biases inferred from the weak-lensing (WL) and SaWLens data are different. As an example, the weighted-mean value at 0.5 Mpc is langbrang = 0.12 for the WL comparison and langbrang = -0.11 for the SaWLens comparison. The ratios of XMM HSE mass profiles to CLASH lensing profiles show a pronounced radial dependence in the 0.3-1.0 Mpc range, with a weighted mean mass bias value rising to langbrang >~ 0.3 at ~1 Mpc for the WL comparison and langbrang ≈ 0.25 for the SaWLens comparison. The enclosed gas mass profiles from both Chandra and XMM rise to a value ≈1

  10. Comparison of Measurements of Profile Stiffness in HSX to Nonlinear Gyrokinetic Calculations

    NASA Astrophysics Data System (ADS)

    Weir, Gavin

    2014-10-01

    Tokamaks and stellarators have observed significant differences in profile stiffness, defined as the ratio of the transient thermal diffusivity obtained from heat pulse propagation to the diffusivity obtained from steady-state power balance. Typically, stellarators have measured stiffness values below 2 and tokamaks have observed stiffness greater than 4. In this paper we present the first results on stiffness measurements in the quasihelically symmetric experiment HSX in which the neoclassical transport is comparable to that in a tokamak and turbulent transport dominates throughout the plasma. Electron Cyclotron Emission (ECE) is used to measure the local electron temperature perturbation from modulating the ECRH system on HSX. Spectral analysis of the ECE data yields a profile of the perturbed amplitude and a resulting transient electron thermal diffusivity that is close to the steady-state diffusivity. This evidence of a lack of stiffness in HSX agrees with the scaling of the steady-state heat flux with temperature gradient. The experimental data is compared to gyrokinetic calculations using the GENE code with two kinetic species. Linear calculations demonstrate that the Trapped Electron Mode (TEM) is the dominant long-wavelength microturbulence instability with growth rates that scale linearly with electron temperature gradient. Nonlinear gyrokinetic flux tube simulations indicate that the TEM contributes significantly to the saturated heat fluxes in HSX, shifting the transport-carrying wavenumbers to larger values than in typical Ion Temperature Gradient (ITG) turbulence. A set of nonlinear simulations are being executed, examining the saturated nonlinear heat flux as a function of the electron temperature gradient, to obtain a stiffness value from the simulations to compare with experimental results. This work is supported by DOE Grant DE-FG02-93ER54222.

  11. Instruments and MethodsIn situ measurements of snow surface roughness using a laser profiler

    NASA Astrophysics Data System (ADS)

    Lacroix, P.; Legrésy, B.; Langley, K.; Hamran, S. E.; Kohler, J.; Roques, S.; Rémy, F.; Dechambre, M.

    The snow surface roughness at centimetre and millimetre scales is an important parameter related to wind transport, snowdrifts, snowfall, snowmelt and snow grain size. Knowledge of the snow surface roughness is also of high interest for analyzing the signal from radar sensors such as SAR, altimeters and scatterometers. Unfortunately, this parameter has seldom been measured over snow surfaces. The techniques used to measure the roughness of other surfaces, such as agricultural or sand soils, are difficult to implement in polar regions because of the harsh climatic conditions. In this paper we develop a device based on a laser profiler coupled with a GPS receiver on board a snowmobile. This instrumentation was tested successfully in midre Lovénbreen, Svalbard, in April 2006. It allowed us to generate profiles of 3 km sections of the snow-covered glacier surface. Because of the motion of the snowmobile, the roughness signal is mixed with the snowmobile signal. We use a distance/frequency analysis (the empirical mode decomposition) to filter the signal. This method allows us to recover the snow surface structures of wavelengths between 4 and 50 cm with amplitudes of >1 mm. Finally, the roughness parameters of snow surfaces are retrieved. The snow surface roughness is found to be dependent on the scales of the observations. The retrieved RMS of the height distribution is found to vary between 0.5 and 9.2 mm, and the correlation length is found to be between 0.6 and 46 cm. This range of measurements is particularly well adapted to the analysis of GHz radar response on snow surfaces.