Science.gov

Sample records for impactor measurement aim

  1. The abbreviated impactor measurement (AIM) concept: part II--Influence of evaporation of a volatile component-evaluation with a "droplet-producing" pressurized metered dose inhaler (pMDI)-based formulation containing ethanol as cosolvent.

    PubMed

    Mitchell, J P; Nagel, M W; Avvakoumova, V; MacKay, H; Ali, R

    2009-01-01

    The abbreviated impactor measurement (AIM) concept is a potential solution to the labor-intensive full-resolution cascade impactor (CI) methodology for inhaler aerosol aerodynamic particle size measurement. In this validation study, the effect of increasing the internal dead volume on determined mass fractions relating to aerodynamic particle size was explored with two abbreviated impactors both based on the Andersen nonviable cascade impactor (ACI) operating principle (Copley fast screening Andersen impactor [C-FSA] and Trudell fast screening Andersen impactor [T-FSA]). A pressurized metered dose inhaler-delivered aerosol producing liquid ethanol droplets after propellant evaporation was chosen to characterize these systems. Measures of extrafine, fine, and coarse particle mass fractions from the abbreviated systems were compared with corresponding data obtained by a full-resolution ACI. The use of liquid ethanol-sensitive filter paper provided insight by rendering locations visible where partly evaporated droplets were still present when the "droplet-producing" aerosol was sampled. Extrafine particle fractions based on impactor-sized mass were near equivalent in the range 48.6% to 54%, comparing either abbreviated system with the benchmark ACI-measured data. The fine particle fraction of the impactor-sized mass determined by the T-FSA (94.4 +/- 1.7%) was greater than using the C-FSA (90.5 +/- 1.4%) and almost identical with the ACI-measured value (95.3 +/- 0.4%). The improved agreement between T-FSA and ACI is likely the result of increasing the dead space between the entry to the induction port and the uppermost impaction stage, compared with that for the C-FSA. This dead space is needed to provide comparable conditions for ethanol evaporation in the uppermost parts of these impactors.

  2. The abbreviated impactor measurement (AIM) concept: part 1--Influence of particle bounce and re-entrainment-evaluation with a "dry" pressurized metered dose inhaler (pMDI)-based formulation.

    PubMed

    Mitchell, J P; Nagel, M W; Avvakoumova, V; MacKay, H; Ali, R

    2009-01-01

    The abbreviated impactor measurement concept is a potential improvement to the labor-intensive full-resolution cascade impactor methodology for inhaler aerosol aerodynamic particle size distribution (APSD) measurement by virtue of being simpler and therefore quicker to execute. At the same time, improved measurement precision should be possible by eliminating stages upon which little or no drug mass is collected. Although several designs of abbreviated impactor systems have been developed in recent years, experimental work is lacking to validate the technique with aerosols produced by currently available inhalers. In part 1 of this two-part article that focuses on aerosols produced by pressurized metered dose inhalers (pMDIs), the evaluation of two abbreviated impactor systems (Copley fast screening Andersen impactor and Trudell fast screening Andersen impactor), based on the full-resolution eight-stage Andersen nonviable cascade impactor (ACI) operating principle, is reported with a formulation producing dry particles. The purpose was to investigate the potential for non-ideal collection behavior associated with particle bounce in relation to internal losses to surfaces from which particles containing active pharmaceutical ingredient are not normally recovered. Both abbreviated impactors were found to be substantially equivalent to the full-resolution ACI in terms of extra-fine and fine particle and coarse mass fractions used as metrics to characterize the APSD of these pMDI-produced aerosols when sampled at 28.3 L/min, provided that precautions are taken to coat collection plates to minimize bounce and entrainment.

  3. Relative precision of inhaler aerodynamic particle size distribution (APSD) metrics by full resolution and abbreviated andersen cascade impactors (ACIs): part 2--investigation of bias in extra-fine mass fraction with AIM-HRT impactor.

    PubMed

    Mitchell, Jolyon P; Nagel, Mark W; Doyle, Cathy C; Ali, Rubina S; Avvakoumova, Valentina I; Christopher, J David; Quiroz, Jorge; Strickland, Helen; Tougas, Terrence; Lyapustina, Svetlana

    2010-09-01

    The purpose of this study was to resolve an anomalously high measure of extra-fine particle fraction (EPF) determined by the abbreviated cascade impactor possibly relevant for human respiratory tract (AIM-HRT) in the experiment described in Part 1 of this two-part series, in which the relative precision of abbreviated impactors was evaluated in comparison with a full resolution Andersen eight-stage cascade impactor (ACI). Evidence that the surface coating used to mitigate particle bounce was laterally displaced by the flow emerging from the jets of the lower stage was apparent upon microscopic examination of the associated collection plate of the AIM-HRT impactor whose cut point size defines EPF. A filter soaked in surfactant was floated on top of this collection plate, and further measurements were made using the same pressurized metered-dose inhaler-based formulation and following the same procedure as in Part 1. Measures of EPF, fine particle, and coarse particle fractions were comparable with those obtained with the ACI, indicating that the cause of the bias had been identified and removed. When working with abbreviated impactors, this precaution is advised whenever there is evidence that surface coating displacement has occurred, a task that can be readily accomplished by microscopic inspection of all collection plates after allowing the impactor to sample ambient air for a few minutes.

  4. Aerosol sampling: Comparison of two rotating impactors for field droplet sizing and volumetric measurements

    USDA-ARS?s Scientific Manuscript database

    This paper compares the collection characteristics of a new rotating impactor for ultra fine aerosols (FLB) with the industry standard (Hock). The volume and droplet size distribution collected by the rotating impactors were measured via spectroscopy and microscopy. The rotary impactors were co-lo...

  5. Comparison of the aerodynamic size distribution of chain-like aggregates measured with a cascade impactor and a spiral centrifuge.

    PubMed

    Allen, M D; Briant, J K; Moss, O R

    1979-06-01

    Several authors have suggested that chain-like aggregates fragment in the jets of cascade impactors and that the impactor consequently underestimates the median aerodynamic diameter and overestimates the geometric standard deviation (GSD). The aerodynamic size distribution of (Pu0.14U0.86)02.2 aggregates were measured simultaneously with two Mercer cascade impactors and a LAPS spiral centrifuge to investigate this problem. Although the median aerodynamic diameters were generally in good agreement, the impactor consistently measured higher values for the GSD than did the spiral centrifuge. Based on experiments in which losses in the centrifuge inlet were measured, it was concluded that the centrifuge had measured the aerodynamic size distribution more accurately than the impactor. Interception of chain-like aggregates on the first few impactor stages may have been the primary reason for the disparity between the impactor and centrifuge measurements.

  6. Calibration of the QCM/SAW Cascade Impactor for Measurement of Ozone

    NASA Technical Reports Server (NTRS)

    Williams, Cassandra K.; Peterson, C. B.; Morris, V. R.

    1997-01-01

    The Quartz Crystal Microbalance Surface Acoustic Wave (QCM/SAW) cascade impactor is an instrument designed to collect size-fractionated distributions of aerosols on a series of quartz crystals and employ SAW devices coated with chemical sensors for gas detection. We are calibrating the cascade impactor in our laboratory for future deployment for in-situ experiments to measure ozone. Experiments have been performed to characterize the QCM and SAW mass loading, saturation limits, mass frequency relationships, and sensitivity. The characteristics of mass loading, saturation limits, mass-frequency relationships, sensitivity, and the loss of ozone on different materials have been quantified.

  7. Virtual impactor

    DOEpatents

    Yeh, Hsu-Chi; Chen, Bean T.; Cheng, Yung-Sung; Newton, George J.

    1988-08-30

    A virtual impactor having improved efficiency and low wall losses in which a core of clean air is inserted into the aerosol flow while aerosol flow is maintained adjacent inner wall surfaces of the focusing portion of the impactor. The flow rate of the core and the length of the throat of the impactor's collection probe, as well as the dimensional relationships of other components of the impactor adjacent the separation region of the impactor, are selected to optimize separation efficiency.

  8. Measurements of size-segregated emission particles by a sampling system based on the cascade impactor

    SciTech Connect

    Janja Tursic; Irena Grgic; Axel Berner; Jaroslav Skantar; Igor Cuhalev

    2008-02-01

    A special sampling system for measurements of size-segregated particles directly at the source of emission was designed and constructed. The central part of this system is a low-pressure cascade impactor with 10 collection stages for the size ranges between 15 nm and 16 {mu}m. Its capability and suitability was proven by sampling particles at the stack (100{sup o}C) of a coal-fired power station in Slovenia. These measurements showed very reasonable results in comparison with a commercial cascade impactor for PM10 and PM2.5 and with a plane device for total suspended particulate matter (TSP). The best agreement with the measurements made by a commercial impactor was found for concentrations of TSP above 10 mg m{sup -3}, i.e., the average PM2.5/PM10 ratios obtained by a commercial impactor and by our impactor were 0.78 and 0.80, respectively. Analysis of selected elements in size-segregated emission particles additionally confirmed the suitability of our system. The measurements showed that the mass size distributions were generally bimodal, with the most pronounced mass peak in the 1-2 {mu}m size range. The first results of elemental mass size distributions showed some distinctive differences in comparison to the most common ambient anthropogenic sources (i.e., traffic emissions). For example, trace elements, like Pb, Cd, As, and V, typically related to traffic emissions, are usually more abundant in particles less than 1 {mu}m in size, whereas in our specific case they were found at about 2 {mu}m. Thus, these mass size distributions can be used as a signature of this source. Simultaneous measurements of size-segregated particles at the source and in the surrounding environment can therefore significantly increase the sensitivity of the contribution of a specific source to the actual ambient concentrations. 25 refs., 3 figs., 2 tabs.

  9. Virtual impactor

    DOEpatents

    Yeh, H.C.; Chen, B.T.; Cheng, Y.S.; Newton, G.J.

    1988-08-30

    A virtual impactor is described having improved efficiency and low wall losses in which a core of clean air is inserted into the aerosol flow while aerosol flow is maintained adjacent to the inner wall surfaces of the focusing portion of the impactor. The flow rate of the core and the length of the throat of the impactor's collection probe, as well as the dimensional relationships of other components of the impactor adjacent the separation region of the impactor, are selected to optimize separation efficiency. 4 figs.

  10. EVALUATION OF THE CMAQ - AIM MODEL AGAINST SIZE AND CHEMICALLY-RESOLVED IMPACTOR DATA AT A COASTAL URBAN SITE

    EPA Science Inventory

    CMAQ-UCD (formerly known as CMAQ-AIM), is a fully dynamic, sectional aerosol model which has been coupled to the Community Multiscale Air Quality (CMAQ) host air quality model. Aerosol sulfate, nitrate, ammonium, sodium, and chloride model outputs are compared against MOUDI data...

  11. EVALUATION OF THE CMAQ - AIM MODEL AGAINST SIZE AND CHEMICALLY-RESOLVED IMPACTOR DATA AT A COASTAL URBAN SITE

    EPA Science Inventory

    CMAQ-UCD (formerly known as CMAQ-AIM), is a fully dynamic, sectional aerosol model which has been coupled to the Community Multiscale Air Quality (CMAQ) host air quality model. Aerosol sulfate, nitrate, ammonium, sodium, and chloride model outputs are compared against MOUDI data...

  12. Satellite and correlative measurements of the stratospheric aerosol. III - Comparison of measurements by SAM II, SAGE, dustsondes, filters, impactors and lidar

    NASA Technical Reports Server (NTRS)

    Russell, P. B.; Mccormick, M. P.; Mcmaster, L. R.; Swissler, T. J.; Rosen, J. M.; Hofmann, D. J.

    1984-01-01

    The SAM II and SAGE satellite sensors, dustsondes, impactors, a filter collector and an airborne lidar were used in a large satellite validation experiment on July 16-19, 1979, at Poker Flat, Alaska. Independent measurements of extinction profiles by SAM II and SAGE are noted to agree with each other and with those derived from the other instruments (within combined uncertainties). The wire impactor-derived results, while also consistent with the others, are coarse due to the relatively large uncertainties in impactor-derived mass, extinction, and number of particles/unit volume whose radius is greater than x microns.

  13. Adaptation of a Cascade Impactor to Flight Measurement of Droplet Size in Clouds

    NASA Technical Reports Server (NTRS)

    Levine, Joseph; Kleinknecht, Kenneth S.

    1951-01-01

    A cascade impactor, an instrument for obtaining: the size distribution of droplets borne in a low-velocity air stream, was adapted for flight cloud droplet-size studies. The air containing the droplets was slowed down from flight speed by a diffuser to the inlet-air velocity of the impactor. The droplets that enter the impactor impinge on four slides coated with magnesium oxide. Each slide catches a different size range. The relation between the size of droplet impressions and the droplet size was evaluated so that the droplet-size distributions may be found from these slides. The magnesium oxide coating provides a permanent record. of the droplet impression that is not affected by droplet evaporation after the. droplets have impinged.

  14. Experience of direct impactor measurements of the structure and composition of stratospheric aerosols in polar latitudes

    NASA Astrophysics Data System (ADS)

    Kondratyev, K. Y.; Ivlev, Leo S.; Ivanov, V. A.; Zhukov, V. M.

    1993-11-01

    The data obtained in 1989 during the launchings to the stratosphere of a two-cascade impactor from the test ground in Apatity have been discussed. The aerosol samples have been analyzed using an electronic microscope to have information on the structure and size distribution of aerosol particles. The chemical and elemental analyses have been made using the methods of mass-spectrometry, IR spectroscopy, neutron activation, and x-ray fluorescence.

  15. Effect of sampling volume on dry powder inhaler (DPI)-emitted aerosol aerodynamic particle size distributions (APSDs) measured by the Next-Generation Pharmaceutical Impactor (NGI) and the Andersen eight-stage cascade impactor (ACI).

    PubMed

    Mohammed, Hlack; Roberts, Daryl L; Copley, Mark; Hammond, Mark; Nichols, Steven C; Mitchell, Jolyon P

    2012-09-01

    Current pharmacopeial methods for testing dry powder inhalers (DPIs) require that 4.0 L be drawn through the inhaler to quantify aerodynamic particle size distribution of "inhaled" particles. This volume comfortably exceeds the internal dead volume of the Andersen eight-stage cascade impactor (ACI) and Next Generation pharmaceutical Impactor (NGI) as designated multistage cascade impactors. Two DPIs, the second (DPI-B) having similar resistance than the first (DPI-A) were used to evaluate ACI and NGI performance at 60 L/min following the methodology described in the European and United States Pharmacopeias. At sampling times ≥2 s (equivalent to volumes ≥2.0 L), both impactors provided consistent measures of therapeutically important fine particle mass (FPM) from both DPIs, independent of sample duration. At shorter sample times, FPM decreased substantially with the NGI, indicative of incomplete aerosol bolus transfer through the system whose dead space was 2.025 L. However, the ACI provided consistent measures of both variables across the range of sampled volumes evaluated, even when this volume was less than 50% of its internal dead space of 1.155 L. Such behavior may be indicative of maldistribution of the flow profile from the relatively narrow exit of the induction port to the uppermost stage of the impactor at start-up. An explanation of the ACI anomalous behavior from first principles requires resolution of the rapidly changing unsteady flow and pressure conditions at start up, and is the subject of ongoing research by the European Pharmaceutical Aerosol Group. Meanwhile, these experimental findings are provided to advocate a prudent approach by retaining the current pharmacopeial methodology.

  16. Comparison of light scattering devices and impactors for particulate measurements in indoor, outdoor, and personal environments.

    PubMed

    Liu, L J Sally; Slaughter, James C; Larson, Timothy V

    2002-07-01

    Short-term monitoring of individual particulate matter (PM) exposures on subjects and inside residences in health effect studies have been sparse due to the lack of adequate monitoring devices. The recent development of small and portable light scattering devices, including the Radiance nephelometer (neph) and the personal DataRAM (pDR) has made this monitoring possible. This paper evaluates the performance of both the passive pDR and neph (without any size fractionation inlet) against measurements from both Harvard impactors (HI2.5) and Harvard personal environmental monitors (HPEM2.5) for PM2.5 in indoor, outdoor, and personal settings. These measurements were taken at the residences and on the person of nonsmoking elderly subjects across the metropolitan Seattle area and represent a wide range of light scattering measurements directly related to exposures and health effects. At low PM levels, nephs provided finer resolution and more precise measurements (precision = 3-8% and uncertainty = 2.8 x 10(-7) m(-1) or <1 microg/m3) than the pDRs. The unbiased precision of pDRs above 10 microg/m3 is around 5% (with an unbiased uncertainty of 4.4 microg/m3). The 24-h average responses of the pDR and neph, as compared to 24-h integrated gravimetric measurements, are not affected by indoor sources of PM. When regressed against 24-h gravimetric measurements, nephs showed higher coefficients of determination (R2 = 0.81-0.93) than pDRs (R2 = 0.77-0.84). The default mass calibration on the pDRs generally overestimated indoor HI2.5 measurements by 56%. When carried by subjects, the pDR overestimated the HPEM2.5 measurements by approximately 27%. Collocated real-time indoor nephs and pDRs at diverse residential sites had varied coefficients of determination across homes (R2 = 0.75-0.96), and the difference between pDR and neph responses increased during cooking hours. This difference was larger during baking or frying episodes than during other cooking or cleaning activities

  17. Asteroid Kinetic Impactor Missions

    NASA Astrophysics Data System (ADS)

    Chesley, Steven

    2015-08-01

    Asteroid impact missions can be carried out as a relatively low-cost add-ons to most asteroid rendezvous missions and such impact experiments have tremendous potential, both scientifically and in the arena of planetary defense.The science returns from an impactor demonstration begin with the documentation of the global effects of the impact, such as changes in orbit and rotation state, the creation and dissipation of an ejecta plume and debris disk, and morphological changes across the body due to the transmission of seismic waves, which might induce landslides and toppling of boulders, etc. At a local level, an inspection of the impact crater and ejecta blanket reveals critical material strength information, as well as spectral differences between the surface and subsurface material.From the planetary defense perspective, an impact demonstration will prove humankind’s capacity to alter the orbit of a potentially threatening asteroid. This technological leap comes in two parts. First, terminal guidance systems that can deliver an impactor with small errors relative to the ~100-200 meter size of a likely impactor have yet to be demonstrated in a deep space environment. Second, the response of an asteroid to such an impact is only understood theoretically due to the potentially significant dependence on the momentum carried by escaping ejecta, which would tend to enhance the deflection by tens of percent and perhaps as much as a factor of a few. A lack of validated understanding of momentum enhancement is a significant obstacle in properly sizing a real-world impactor deflection mission.This presentation will describe the drivers for asteroid impact demonstrations and cover the range of such concepts, starting with ESA’s pioneering Don Quijote mission concept and leading to a brief description of concepts under study at the present time, including the OSIRIS-REx/ISIS, BASiX/KIX and AIM/DART (AIDA) concepts.

  18. Measuring Sub-micron Size Fractionated Particulate Matter on Aluminum Impactor Disks

    SciTech Connect

    Buchholz, B A; Zermeno, P; Hwang, H; Young, T M

    2009-07-28

    Sub-micron sized airborne particulate matter is not collected well on regular quartz or glass fiber filter papers. We used a micro-orifice uniform deposit impactor (MOUDI) to size fractionate particulate matter (PM) into six size fractions and deposit it on specially designed high purity thin aluminum disks. The MOUDI separated PM into fractions 56-100 nm, 100-180 nm, 180-320 nm, 320-560 nm, 560-1000 nm, and 1000-1800 nm. Since MOUDI have low flow rates, it takes several days to collect sufficient carbon on 47 mm foil disks. The small carbon mass (20-200 microgram C) and large aluminum substrate ({approx}25 mg Al) presents several challenges to production of graphite targets for accelerator mass spectrometry (AMS) analysis. The Al foil consumes large amounts of oxygen as it is heated and tends to melt into quartz combustion tubes, causing gas leaks. We describe sample processing techniques to reliably produce graphitic targets for {sup 14}C-AMS analysis of PM deposited on Al impact foils.

  19. Measuring Submicron-Sized Fractionated Particulate Matter on Aluminum Impactor Disks

    PubMed Central

    Buchholz, Bruce A.; Zermeño, Paula; Hwang, Hyun-Min; Young, Thomas M.; Guilderson, Thomas P.

    2011-01-01

    Sub-micron sized airborne particulate matter (PM) is not collected well on regular quartz or glass fiber filter papers. We used a micro-orifice uniform deposit impactor (MOUDI) to fractionate PM into six size fractions and deposit it on specially designed high purity thin aluminum disks. The MOUDI separated PM into fractions 56–100 nm, 100–180 nm, 180–320 nm, 320–560 nm, 560–1000 nm, and 1000–1800 nm. Since the MOUDI has a low flow rate (30 L/min), it takes several days to collect sufficient carbon on 47 mm foil disks. The small carbon mass (20–200 microgram C) and large aluminum substrate (~25 mg Al) present several challenges to production of graphite targets for accelerator mass spectrometry (AMS) analysis. The Al foil consumes large amounts of oxygen as it is heated and tends to melt into quartz combustion tubes, causing gas leaks. We describe sample processing techniques to reliably produce graphitic targets for 14C-AMS analysis of PM deposited on Al impact foils. PMID:22228915

  20. Characterization and first results of an ice nucleating particle measurement system based on counterflow virtual impactor technique

    NASA Astrophysics Data System (ADS)

    Schenk, L. P.; Mertes, S.; Kästner, U.; Frank, F.; Nillius, B.; Bundke, U.; Rose, D.; Schmidt, S.; Schneider, J.; Worringen, A.; Kandler, K.; Bukowiecki, N.; Ebert, M.; Curtius, J.; Stratmann, F.

    2014-10-01

    A specific instrument combination was developed to achieve a better microphysical and chemical characterization of atmospheric aerosol particles that have the potential to act as ice nucleating particles (INP). For this purpose a pumped counterflow virtual impactor system called IN-PCVI was set up and characterized to separate ice particles that had been activated on INP in the Fast Ice Nucleus Chamber (FINCH) from interstitial, non-activated particles. This coupled setup consisting of FINCH (ice particle activation and counting), IN-PCVI (INP separation and preparation), and further aerosol instrumentation (INP characterization) had been developed for the application in field experiments. The separated INP were characterized on-line with regard to their total number concentration, number size distribution and chemical composition, especially with the Aircraft-based Laser Ablation Aerosol Mass Spectrometer ALABAMA. Moreover, impactor samples for electron microscopy were taken. Due to the coupling the IN-PCVI had to be operated with different flow settings than known from literature, which required a further characterization of its cut-off-behavior. Taking the changed cut-off-behavior into account, the INP number concentration measured by the IN-PCVI system was in good agreement with the one detected by the FINCH optics for water saturation ratios up to 1.01 (ice saturation ratios between 1.21-1.34 and temperatures between -18 and -26 °C). First field results of INP properties are presented which were gained during the INUIT-JFJ/CLACE 2013 campaign at the high altitude research station Jungfraujoch in the Bernese Alps, Switzerland (3580 m a.s.l.).

  1. A space mission to detect imminent Earth impactors

    NASA Astrophysics Data System (ADS)

    Valsecchi, G. B.; Perozzi, E.; Rossi, A.

    2015-03-01

    One of the goals of NEO surveys is to discover Earth impactors before they hit. How much warning time is desirable depends on the size of the impactors: for the larger ones more time is needed to mount effective mitigation measures. Initially, NEO surveys were aimed at large impactors, that can have significant global effects; however, their typical time scale is orders of magnitude larger than human lifetime. At the other extreme, monthly and annual events, liberating energies of the order of 1 to 10 kilotons, are immaterial as a threat to mankind, not justifying substantial expenditure on them. Intermediate events are of more concern: in the megatons range, timescales are of the order of centuries, and the damage can be substantial. A classical example is the Tunguska event, in which a body with a diameter of about 30 to 50 m liberated about 5 megatons in the atmosphere, devastating 2 000 square kilometers of Siberian forest.

  2. Mission Orbit Design of CubeSat Impactor Measuring Lunar Local Magnetic Field

    NASA Astrophysics Data System (ADS)

    Lee, Jeong-Ah; Park, Sang-Young; Kim, Youngkwang; Bae, Jonghee; Lee, Donghun; Ju, Gwanghyeok

    2017-06-01

    The current study designs the mission orbit of the lunar CubeSat spacecraft to measure the lunar local magnetic anomaly. To perform this mission, the CubeSat will impact the lunar surface over the Reiner Gamma swirl on the Moon. Orbit analyses are conducted comprising ΔV and error propagation analysis for the CubeSat mission orbit. First, three possible orbit scenarios are presented in terms of the CubeSat’s impacting trajectories. For each scenario, it is important to achieve mission objectives with a minimum ΔV since the CubeSat is limited in size and cost. Therefore, the ΔV needed for the CubeSat to maneuver from the initial orbit toward the impacting trajectory is analyzed for each orbit scenario. In addition, error propagation analysis is performed for each scenario to evaluate how initial errors, such as position error, velocity error, and maneuver error, that occur when the CubeSat is separated from the lunar orbiter, eventually affect the final impact position. As a result, the current study adopts a CubeSat release from the circular orbit at 100 km altitude and an impact slope of 15°, among the possible impacting scenarios. For this scenario, the required ΔV is calculated as the result of the ΔV analysis. It can be used to practically make an estimate of this specific mission’s fuel budget. In addition, the current study suggests error constraints for ΔV for the mission.

  3. Aerosol size distributions measured in urban, rural and high-alpine air with an electrical low pressure impactor (ELPI)

    NASA Astrophysics Data System (ADS)

    Held, A.; Zerrath, A.; McKeon, U.; Fehrenbach, T.; Niessner, R.; Plass-Dülmer, C.; Kaminski, U.; Berresheim, H.; Pöschl, U.

    An electrical low pressure impactor (ELPI) was used to study atmospheric aerosol particle number, surface, and mass concentrations and size distributions over a diameter range of 7 nm-10 μm at urban, rural and high-alpine locations along an alpine altitude transect across Southern Germany. The measurements were performed in the city of Munich and at the global atmosphere watch (GAW) stations Hohenpeißenberg and Zugspitze in the years 2001-2004. To minimize particle bounce effects and enable chemical analysis of the collected particles without disturbance by grease on the impaction substrates, the sample flow was conditioned to about 75% relative humidity. The performance of the ELPI instrument was evaluated by comparison with well-established aerosol measurement techniques including condensation particle counters, scanning and differential mobility particle sizers, filter sampling, and gravimetric determination of particulate mass. In general, particle number concentrations, size distributions, and PM2.5 concentrations determined with the ELPI were in good agreement with alternative techniques (rank correlation coefficients ρ = 0.70-0.95). The ELPI filter stage data for the particle diameter range of 7-30 nm, however, appeared to be strongly biased towards high values. Long-term measurements at the rural site (Hohenpeißenberg) revealed distinct seasonal patterns with the highest number concentrations in summer (median daily average: 3100 cm -3) and the highest mass concentrations in spring and fall (median daily average PM2.5 and PM10: 21-25 and 27-35 μg m -3, respectively). In spring and fall we also observed pronounced maxima of particle surface and mass concentration in the coarse mode (peak at ˜3 μm), which are most likely due to primary biological material. Relatively clean air (PM10 < = 5 μg m -3) was generally advected from the Alps (SW), whereas urban air from Munich (NE) clearly contributed to elevated particle mass loadings (PM10 > = 10 μg m -3).

  4. Gas Dynamics, Characterization, and Calibration of Fast Flow Flight Cascade Impactor Quartz Crystal Microbalances (QCM) for Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Grant, J.R.; Thorpe, A. N.; James, C.; Michael, A.; Ware, M.; Senftle, F.; Smith, S.

    1997-01-01

    During recent high altitude flights, we have tested the aerosol section of the fast flow flight cascade impactor quartz crystal microbalance (QCM) on loan to Howard University from NASA. The aerosol mass collected during these flights was disappointingly small. Increasing the flow through the QCM did not correct the problem. It was clear that the instrument was not being operated under proper conditions for aerosol collect ion primarily because the gas dynamics is not well understood. A laboratory study was therefore undertaken using two different fast flow QCM's in an attempt to establish the gas flow characteristics of the aerosol sections and its effect on particle collection, Some tests were made at low temperatures but most of the work reported here was carried out at room temperature. The QCM is a cascade type impactor originally designed by May (1945) and later modified by Anderson (1966) and Mercer et al (1970) for chemical gas analysis. The QCM has been used extensively for collecting and sizing stratospheric aerosol particles. In this paper all flow rates are given or corrected and referred to in terms of air at STP. All of the flow meters were kept at STP. Although there have been several calibration and evaluation studies of moderate flow cascade impactors of less than or equal to 1 L/rein., there is little experimental information on the gas flow characteristics for fast flow rates greater than 1 L/rein.

  5. Evaluating Extinction Values using Wire Impactor Data

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The purpose of the study was to compare the extinctions calculated from data obtained with the Ames Wire Impactor to extinctions measured with the SAGE H satellite system. The comparison was intended to serve as a validation of the extinctions obtained using the wire impactor data. It was felt that if the extinctions obtained by the two diverse methods agreed well, it would be an indication that the number densities measured on the wires were correct.

  6. 121. Man with temperature probe aimed at armature measuring temperature ...

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

    121. Man with temperature probe aimed at armature measuring temperature as armature heats up between the two electrodes. March 27, 1985 - Statue of Liberty, Liberty Island, Manhattan, New York County, NY

  7. Asteroid Impact & Deflection Assessment mission: Kinetic impactor

    NASA Astrophysics Data System (ADS)

    Cheng, A. F.; Michel, P.; Jutzi, M.; Rivkin, A. S.; Stickle, A.; Barnouin, O.; Ernst, C.; Atchison, J.; Pravec, P.; Richardson, D. C.; AIDA team

    2016-02-01

    The Asteroid Impact & Deflection Assessment (AIDA) mission will be the first space experiment to demonstrate asteroid impact hazard mitigation by using a kinetic impactor to deflect an asteroid. AIDA is an international cooperation, consisting of two mission elements: the NASA Double Asteroid Redirection Test (DART) mission and the ESA Asteroid Impact Mission (AIM) rendezvous mission. The primary goals of AIDA are (i) to test our ability to perform a spacecraft impact on a potentially hazardous near-Earth asteroid and (ii) to measure and characterize the deflection caused by the impact. The AIDA target will be the binary near-Earth asteroid (65803) Didymos, with the deflection experiment to occur in late September, 2022. The DART impact on the secondary member of the binary at 7 km/s is expected to alter the binary orbit period by about 4 minutes, assuming a simple transfer of momentum to the target, and this period change will be measured by Earth-based observatories. The AIM spacecraft will characterize the asteroid target and monitor results of the impact in situ at Didymos. The DART mission is a full-scale kinetic impact to deflect a 150 m diameter asteroid, with known impactor conditions and with target physical properties characterized by the AIM mission. Predictions for the momentum transfer efficiency of kinetic impacts are given for several possible target types of different porosities, using Housen and Holsapple (2011) crater scaling model for impact ejecta mass and velocity distributions. Results are compared to numerical simulation results using the Smoothed Particle Hydrodynamics code of Jutzi and Michel (2014) with good agreement. The model also predicts that the ejecta from the DART impact may make Didymos into an active asteroid, forming an ejecta coma that may be observable from Earth-based telescopes. The measurements from AIDA of the momentum transfer from the DART impact, the crater size and morphology, and the evolution of an ejecta coma will

  8. 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. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Evaluating Extinction Values Using Wire Impactor Data

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The purpose of the study was to compare the extinctions calculated from data obtained with the Ames Wire Impactor to extinctions measured with the SAGE 11 satellite system. The comparison was intended to serve as a validation of the extinctions obtained using the wire impactor data. It was felt that if the extinctions obtained by the two diverse methods agreed well, it would be an indication that the number densities measured on the wires were correct. Tables and charts are presented to show the extinction values from the two different methods.

  10. High efficiency virtual impactor

    DOEpatents

    Loo, B.W.

    1980-03-27

    Environmental monitoring of atmospheric air is facilitated by a single stage virtual impactor for separating an inlet flow (Q/sub 0/) having particulate contaminants into a coarse particle flow (Q/sub 1/) and a fine particle flow (Q/sub 2/) to enable collection of such particles on different filters for separate analysis. An inlet particle acceleration nozzle and coarse particle collection probe member having a virtual impaction opening are aligned along a single axis and spaced apart to define a flow separation region at which the fine particle flow (Q/sub 2/) is drawn radially outward into a chamber while the coarse particle flow (Q/sub 1/) enters the virtual impaction opening.

  11. Particle chemistry impactor experiment

    NASA Astrophysics Data System (ADS)

    Pueschel, R. F.; Snetsinger, K. G.; Ferry, G. V.; Goodman, J. K.; Verma, S.

    1990-01-01

    Polar stratospheric cloud (PSC) particles are collected on impactors and studied with regard to physical and chemical properties to help explain the importance of heterogeneous chemical reactions for stratospheric ozone depletion. The nitric, hydrochloric, and sulfuric acid content of stratospheric aerosol particles collected at 18 km altitude was determined. It is suggested that nitric acid is a component of polar stratospheric clouds. This is important for two reasons: (1) it proves that chlorine activation takes place at the surface of PSC particles by converting chemically inert chlorine nitrate to chlorine radicals that can react with ozone; and (2) if the PSC particles are large enough to settle out from the stratosphere, the possibility of nitric acid removal can result in the denitrification of the stratosphere.

  12. Particle chemistry impactor experiment

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Snetsinger, K. G.; Ferry, G. V.; Goodman, J. K.; Verma, S.

    1990-01-01

    Polar stratospheric cloud (PSC) particles are collected on impactors and studied with regard to physical and chemical properties to help explain the importance of heterogeneous chemical reactions for stratospheric ozone depletion. The nitric, hydrochloric, and sulfuric acid content of stratospheric aerosol particles collected at 18 km altitude was determined. It is suggested that nitric acid is a component of polar stratospheric clouds. This is important for two reasons: (1) it proves that chlorine activation takes place at the surface of PSC particles by converting chemically inert chlorine nitrate to chlorine radicals that can react with ozone; and (2) if the PSC particles are large enough to settle out from the stratosphere, the possibility of nitric acid removal can result in the denitrification of the stratosphere.

  13. Sampling stratospheric aerosols with impactors

    NASA Technical Reports Server (NTRS)

    Oberbeck, Verne R.

    1989-01-01

    Derivation of statistically significant size distributions from impactor samples of rarefield stratospheric aerosols imposes difficult sampling constraints on collector design. It is shown that it is necessary to design impactors of different size for each range of aerosol size collected so as to obtain acceptable levels of uncertainty with a reasonable amount of data reduction.

  14. Development of a new real-time method for measuring S(IV) in cloud water using a counter-flow virtual impactor

    NASA Astrophysics Data System (ADS)

    Dixon, Roy W.; Charlson, Robert J.

    1994-07-01

    A new method of analysis for S(IV) is described incorporating a counter-flow virtual impactor for collection and evaporation of cloud droplets with an SO2 analyzer. This technique allows analysis of aqueous S(IV) concentration in real-time and overcomes some sampling or analysis problems of conventional sampling with bulk cloud water collectors and wet chemical analysis methods. The technique is demonstrated by the correlated responses of the S(IV) instrument and instruments measuring physical properties of clouds while passing in and out of clouds. Measured aqueous S(IV) concentrations ranged from the detection limit (0.1nmol per m3 of air) to 1.8nmol m-3 in clouds in Ohio. S(IV) molar concentrations (moles/l of cloud water) were not calculable from these measurements, but can be calculated when a measurement of the liquid water content of the collected cloud water is made simultaneously.

  15. High efficiency virtual impactor

    DOEpatents

    Loo, Billy W.

    1981-01-01

    Environmental monitoring of atmospheric air is facilitated by a single stage virtual impactor (11) for separating an inlet flow (Q.sub.O) having particulate contaminants into a coarse particle flow (Q.sub.1) and a fine particle flow (Q.sub.2) to enable collection of such particles on different filters (19a, 19b) for separate analysis. An inlet particle acceleration nozzle (28) and coarse particle collection probe member (37) having a virtual impaction opening (41) are aligned along a single axis (13) and spaced apart to define a flow separation region (14) at which the fine particle flow (Q.sub.2) is drawn radially outward into a chamber (21) while the coarse particle flow (Q.sub.1) enters the virtual impaction opening (41). Symmetrical outlet means (47) for the chamber (21) provide flow symmetry at the separation region (14) to assure precise separation of particles about a cutpoint size and to minimize losses by wall impaction and gravitational settling. Impulse defocusing means (42) in the probe member (37) provides uniform coarse particle deposition on the filter (19a) to aid analysis. Particle losses of less than 1% for particles in the 0 to 20 micron range may be realized.

  16. Safety assessment characteristics of pedestrian legform impactors in vehicle-front impact tests.

    PubMed

    Matsui, Yasuhiro

    2014-12-01

    This study investigated the characteristics of safety assessment results of front-area vehicle impact tests carried out using the Transport Research Laboratory (TRL) legform impactor and a flexible legform impactor (FLEX legform impactor). Different types of vehicles (sedan, sport utility vehicle, high-roof K-car, and light cargo van) were examined. The impact locations in the study were the center of the bumper and an extremely stiff structure of the bumper (i.e., in front of the side member) of each tested vehicle. The measured injury criteria were normalized by injury assessment reference values of each legform impactor. The test results for center and side-member impacts indicated that there were no significant differences in ligament injury assessments derived from the normalized knee ligament injury measures between the TRL legform impactor and the FLEX legform impactor. Evaluations made using the TRL legform impactor and the FLEX legform impactor are thus similar in the vehicle safety investigation for knee ligament injury. Vehicle-center impact test results revealed that the tibia fracture assessments derived from the normalized tibia fracture measures did not significantly differ between the TRL legform impactor and the FLEX legform impactor. However, for an impact against an extremely stiff structure, there was a difference in the tibia fracture assessment between the FLEX legform impactor and the TRL legform impactor owing to their different sensor types.

  17. The Autism Impact Measure (AIM): Initial Development of a New Tool for Treatment Outcome Measurement

    ERIC Educational Resources Information Center

    Kanne, Stephen M.; Mazurek, Micah O.; Sikora, Darryn; Bellando, Jayne; Branum-Martin, Lee; Handen, Benjamin; Katz, Terry; Freedman, Brian; Powell, Mary Paige; Warren, Zachary

    2014-01-01

    The current study describes the development and psychometric properties of a new measure targeting sensitivity to change of core autism spectrum disorder (ASD) symptoms, the Autism Impact Measure (AIM). The AIM uses a 2-week recall period with items rated on two corresponding 5-point scales (frequency and impact). Psychometric properties were…

  18. A novel graded density impactor

    NASA Astrophysics Data System (ADS)

    Winter, R. E.; Cotton, M.; Harris, E. J.; Chapman, D. J.; Eakins, D.

    2014-05-01

    Ramp loading using graded-density-impactors as flyers in gas-gun-driven plate impact experiments can yield new and useful information about the equation of state and the strength properties of the loaded material. Selective Laser Melting, an additive manufacture technique, was used to manufacture a graded density flyer, termed the "bed of nails" (BON). A 2 mm thick × 100 mm diameter solid disc of stainless steel formed a base for an array of tapered spikes of length 6 mm and spaced 1 mm apart. The two experiments to test the concept were performed at impact velocities of 900 m/s and 1100 m/s using the 100 mm gas gun at the Institute of Shock Physics at Imperial College, London. In each experiment a BON flyer was impacted onto a copper buffer plate which helped to smooth out perturbations in the wave profile. The ramp delivered to the copper buffer was in turn transmitted to three tantalum targets of thicknesses 3, 5 and 7 mm, which were mounted in contact with the back face of the copper. Heterodyne velocimetry was used to measure the velocity-time history, at the back faces of the tantalum discs. The wave profiles display a smooth increase in velocity over a period of ~2.5 us, with no indication of a shock jump. The measured profiles have been analysed to generate a stress strain curve for tantalum. The results have been compared with the predictions of the Sandia National Laboratories hydrocode, CTH.

  19. A novel graded density impactor

    NASA Astrophysics Data System (ADS)

    Winter, Ron; Cotton, Matthew; Harris, Ernest; Eakins, Daniel; Chapman, David

    2013-06-01

    Ramp loading using graded-density-impactors as flyers in plate impact experiments can yield useful information about the dynamic properties of the loaded material. Selective Laser Melting, an additive manufacture technique, was used to fabricate a graded-density flyer, termed the ``bed of nails'' (BON). A 2 mm thick x 100 mm diameter solid disc of stainless steel formed a base for an array of tapered spikes of length 6 mm and spaced 1 mm apart. Two experiments to test the concept were performed at impact velocities of 900 m/s and 1100 m/s using the 100 mm gas gun at The Institute of Shock Physics, Imperial College, London. In each experiment a BON flyer was impacted onto a copper buffer plate which helped to smooth out perturbations in the wave profile. The ramp delivered to the copper buffer was in turn transmitted to three tantalum targets of thicknesses 3, 5 and 7 mm, mounted in contact with the back face of the copper. Heterodyne velocimetry was used to measure the velocity-time history, at the back faces of the tantalum discs. The wave profiles display a smooth increase in free surface velocity over a period of about 2.5 microseconds. The measured profiles have been analysed to generate a stress vs. volume curve for tantalum.

  20. The airborne mass spectrometer AIMS - Part 1: AIMS-H2O for UTLS water vapor measurements

    NASA Astrophysics Data System (ADS)

    Kaufmann, S.; Voigt, C.; Jurkat, T.; Thornberry, T.; Fahey, D. W.; Gao, R.-S.; Schlage, R.; Schäuble, D.; Zöger, M.

    2015-12-01

    In the upper troposphere and lower stratosphere (UTLS), the accurate quantification of low water vapor concentrations has presented a significant measurement challenge. The instrumental uncertainties are passed on to estimates of H2O transport, cloud formation and the H2O role in the UTLS energy budget and resulting effects on surface temperatures. To address the uncertainty in UTLS H2O determination, the airborne mass spectrometer AIMS-H2O, with in-flight calibration, has been developed for fast and accurate airborne water vapor measurements. We present the new setup to measure water vapor by direct ionization of ambient air. Air is sampled via a backward facing inlet that includes a bypass flow to assure short residence times (< 0.2 s) in the inlet line, which allows the instrument to achieve a time resolution of ∼ 4 Hz. From the main inlet flow, a smaller flow is extracted into the novel pressure-controlled gas discharge ion source of the mass spectrometer. The air is directed through the gas discharge region where water molecules react to form hydronium ion clusters, H3O+(H2O)n (n= 0, 1, 2), in a complex reaction scheme similar to the reactions in the D-region of the ionosphere. These ions are counted to quantify the ambient water vapor mixing ratio. The instrument is calibrated during flight using a new calibration source based on the catalytic reaction of H2 and O2 on a Pt surface to generate a calibration standard with well defined and stable H2O mixing ratios. In order to increase data quality over a range of mixing ratios, two data evaluation methods are presented for lower and higher H2O mixing ratios respectively, using either only the H3O+(H2O) ions or the ratio of all water vapor dependent ions to the total ion current. Altogether, a range of water vapor mixing ratios from 1 to 500 ppmv (mole ratio, 10-6 mol mol-1) can be covered with an accuracy between 7 and 15 %. AIMS-H2O was deployed on two DLR research aircraft, the Falcon during CONCERT

  1. The airborne mass spectrometer AIMS - Part 1: AIMS-H2O for UTLS water vapor measurements

    NASA Astrophysics Data System (ADS)

    Kaufmann, Stefan; Voigt, Christiane; Jurkat, Tina; Thornberry, Troy; Fahey, David W.; Gao, Ru-Shan; Schlage, Romy; Schäuble, Dominik; Zöger, Martin

    2016-03-01

    In the upper troposphere and lower stratosphere (UTLS), the accurate quantification of low water vapor concentrations has presented a significant measurement challenge. The instrumental uncertainties are passed on to estimates of H2O transport, cloud formation and the role of H2O in the UTLS energy budget and resulting effects on surface temperatures. To address the uncertainty in UTLS H2O determination, the airborne mass spectrometer AIMS-H2O, with in-flight calibration, has been developed for fast and accurate airborne water vapor measurements. We present a new setup to measure water vapor by direct ionization of ambient air. Air is sampled via a backward facing inlet that includes a bypass flow to assure short residence times (< 0.2 s) in the inlet line, which allows the instrument to achieve a time resolution of ˜ 4 Hz, limited by the sampling frequency of the mass spectrometer. From the main inlet flow, a smaller flow is extracted into the novel pressure-controlled gas discharge ion source of the mass spectrometer. The air is directed through the gas discharge region where ion-molecule reactions lead to the production of hydronium ion clusters, H3O+(H2O)n (n = 0, 1, 2), in a complex reaction scheme similar to the reactions in the D-region of the ionosphere. These ions are counted to quantify the ambient water vapor mixing ratio. The instrument is calibrated during flight using a new calibration source based on the catalytic reaction of H2 and O2 on a Pt surface to generate a calibration standard with well-defined and stable H2O mixing ratios. In order to increase data quality over a range of mixing ratios, two data evaluation methods are presented for lower and higher H2O mixing ratios respectively, using either only the H3O+(H2O) ions or the ratio of all water vapor dependent ions to the total ion current. Altogether, a range of water vapor mixing ratios from 1 to 500 parts per million by volume (ppmv) can be covered with an accuracy between 7 and 15 %. AIMS

  2. Study of Infra Red femtosecond laser induced aerosols using Transmission Electron Microscopy and Low Pressure Impactor: implications for LA-ICP-MS measurements

    NASA Astrophysics Data System (ADS)

    D'Abzac, F.; Seydoux-Guillaume, A.; Poitrasson, F.; Freydier, R.; Datas, L.

    2009-12-01

    Processes linked to the creation of laser induced aerosols are not yet fully understood, especially in the Infra Red femtosecond regime. It is of great interest to understand these mechanisms in order to better constrain chemical fractionation observed on LA-ICP-MS signals. A meticulous study of particles produced by IR-fs laser ablation (λ=800nm, τ=60fs, E=0,1-1mJ/pulse, f=5Hz) has been conducted on a wide variety of samples (phosphate, silicates, oxides, glass and metals), using transmission electron microscopy (Bright field TEM and EDS). Afterwards, observations using TEM coupled with focused ion beam (FIB) preparation have been performed on craters, to study the laser induced redeposition structure and chemistry and bring comparison with related aerosols. Finally, quantitative data have been collected using a low pressure impactor (LPI) device. Observed aerosols always consist in amorphous dark beads (30-150nm diameter) and more or less developed clusters (>100nm) of smaller particles (10-15 nm diameter). Their composition differs from each other and from the initial sample. Counting reveals a decreasing density of particle over 10min of ablation, while size distribution appears Gaussian, monomodal and remains centered on 90-100nm. Craters in monazite (phosphate, Moacir, Itembe, Brazil) show two different domains. Strained areas, induced by very high pressure resulting from matter removal, and, on the top, a thin layer (~250nm in the single shot crater for E=0,1mJ/pulse) probably melted then annealed. Qualitative EDS data from the latter shows the same composition as unshocked sample. Data allows an advanced reconstruction of events driving matter from crater digging through plasma and finally into metastable particles. Numerous theoretical[1] and experimental[2,3] reports, focused on each successive stage, help putting forward the hypothesis of a single complex process of condensation/coalescence. Direct qualitative and quantitative measurements on aerosols

  3. Development of a low-pressure "counterflow exchanging virtual impactor" for aerosol analysis, and, Measurement of ozone mixing ratios and meteorological parameters through the boundary layer at Summit, Greenland

    NASA Astrophysics Data System (ADS)

    Boulter, James Edward

    Trace atmospheric gases may provide significant interferences for in situ chemical analyses of atmospheric particles. Hence, a continuous technique to selectively remove the aerosol fraction from ambient air is desirable. A low-pressure "counterflow exchanging virtual impactor" (LP-CEVI), based upon the principle of inertial particle impaction, was developed to exchange aerosol particles larger than a certain aerodynamic size into a stream of inert gas while excluding atmospheric gases. Impactor particle transmission was characterized by two experimental techniques, one utilizing condensation particle counting of size-selected, nebulized salt particles and the other utilizing filter collection and extraction of monodisperse fluorescent microspheres. The impactor was also characterized for the ability to exclude ambient air, using the detection of nitric oxide by gas-phase chemiluminescence resulting from its reaction with ozone. Within certain pressure and counterflow regimes, the LP-CEVI was found to reproducibly transmit particles greater than approximately 0.2 mum in diameter while excluding more than 99.9% of ambient gas from the particle stream. Potential applications of the impactor to laboratory and field studies are discussed. Chemical processes occurring in firn air, interstitial air within the top several centimeters of snowpack, are important to understanding the composition of the Arctic troposphere. Research was conducted at Summit, Greenland in June 2000 to measure vertical profiles of the ozone mixing ratio and various meteorological parameters through the top of the boundary layer from tethered helium balloon platforms. Ozone mixing ratio profiles were measured using electrochemical ozonesondes in addition to a compact, lightweight, single-beam UV absorbance ozone instrument designed for field use. Profiles of meteorological parameters such as temperature, water vapor pressure, wind speed, and wind direction were measured using radiosondes and

  4. An investigation of the NOCSAE linear impactor test method based on in vivo measures of head impact acceleration in American football.

    PubMed

    Gwin, Joseph T; Chu, Jeffery J; Diamond, Solomon G; Halstead, P David; Crisco, Joseph J; Greenwald, Richard M

    2010-01-01

    The performance characteristics of football helmets are currently evaluated by simulating head impacts in the laboratory using a linear drop test method. To encourage development of helmets designed to protect against concussion, the National Operating Committee for Standards in Athletic Equipment recently proposed a new headgear testing methodology with the goal of more closely simulating in vivo head impacts. This proposed test methodology involves an impactor striking a helmeted headform, which is attached to a nonrigid neck. The purpose of the present study was to compare headform accelerations recorded according to the current (n=30) and proposed (n=54) laboratory test methodologies to head accelerations recorded in the field during play. In-helmet systems of six single-axis accelerometers were worn by the Dartmouth College men's football team during the 2005 and 2006 seasons (n=20,733 impacts; 40 players). The impulse response characteristics of a subset of laboratory test impacts (n=27) were compared with the impulse response characteristics of a matched sample of in vivo head accelerations (n=24). Second- and third-order underdamped, conventional, continuous-time process models were developed for each impact. These models were used to characterize the linear head/headform accelerations for each impact based on frequency domain parameters. Headform linear accelerations generated according to the proposed test method were less similar to in vivo head accelerations than headform accelerations generated by the current linear drop test method. The nonrigid neck currently utilized was not developed to simulate sport-related direct head impacts and appears to be a source of the discrepancy between frequency characteristics of in vivo and laboratory head/headform accelerations. In vivo impacts occurred 37% more frequently on helmet regions, which are tested in the proposed standard than on helmet regions tested currently. This increase was largely due to the

  5. Leftovers from Ancient Lunar Impactors

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.; Taylor, G. J.

    2012-06-01

    The lunar basins mark a time, over three and a half billion years ago, of extreme bombardment in the early Solar System, including in the young Earth-Moon system. What hit the Moon (and by proxy, Earth) at the end of the basin-forming epoch has now been determined directly, for the first time, from the analyses of impactor debris found in samples returned from the Apollo 16 landing site. Katie Joy (Lunar and Planetary Institute, NASA Lunar Science Institute) and colleagues working in Houston and Honolulu identified 30 tiny mineral and rock relics of chondritic impactors during their systematic search of regolith breccias bormed between about 3.8-3.4 billion years ago. The relatively uniform composition of these chondritic meteorite fragments is in contrast to the variety of meteorites in our collections, supporting the idea that the influx of materials bombarding the Moon and Earth 3.4 billion years ago, or more, was different from more recent times.

  6. A modular tool for analyzing cascade impactors data to improve exposure assessment to airborne nanomaterials

    NASA Astrophysics Data System (ADS)

    Bau, Sébastien; Witschger, Olivier

    2013-04-01

    Cascade impactors are widely used to provide particle size distributions for the study of aerosols in workplaces and ambient air. In the frame of exposure assessment to airborne particles, one of their main advantages is the possibility to perform further off-line analysis (e.g. electron microscopy, physical-chemical characterization by XRD, ICP-MS, etc.) on the collected samples according to particle size. However, the large channel width makes the particle size distributions not enough size-resolved. Furthermore, in spite of the sharpness of the collection efficiency curves, the existence of an overlap between stages renders data interpretation difficult. This work aim was to develop a modular program allowing the inversion of data stemming from cascade impactors based on the mass (or any quantity) collected on each impaction stage. Through a precise description of the collection efficiency curves of the different stages, the software provides a continuous curve (from 100 to 1000 points) using the Markowski method, and more particularly the Twomey iterative algorithm, according to several publications about inverse problems in cascade impactors. An additional option consists in determining the experimental error at each point of the inverse curve, performed by realizing several consecutive inversions. The inversion procedure was first tested and optimized for the case of the SIOUTAS personal sampler. Validation of the calculation was performed considering theoretical aerosols. Then, the software was used for two sets of data obtained during field measurement campaigns.

  7. Let's Measure What No One Teaches: PISA, NCLB, and the Shrinking Aims of Education

    ERIC Educational Resources Information Center

    Labaree, David

    2014-01-01

    Background/Context: PISA has come up with an ingenious solution to the problem of how to measure student achievement across national school systems with different curricula. Instead of measuring how well students learn what they are taught in each system, it measures a set of economically useful skills that no one teaches. Purpose: The aim is to…

  8. Let's Measure What No One Teaches: PISA, NCLB, and the Shrinking Aims of Education

    ERIC Educational Resources Information Center

    Labaree, David

    2014-01-01

    Background/Context: PISA has come up with an ingenious solution to the problem of how to measure student achievement across national school systems with different curricula. Instead of measuring how well students learn what they are taught in each system, it measures a set of economically useful skills that no one teaches. Purpose: The aim is to…

  9. The cometary impactor flux at the Earth

    NASA Astrophysics Data System (ADS)

    Weissman, Paul R.

    2007-05-01

    Long- and short-period comets make up a small but important fraction of the potential impactors on the Earth. Because of their higher approach velocities, comets are more energetic impactors than most asteroids. Terrestrial encounters with long-period comets are difficult to predict because these comets enter the planetary region at random times and from all directions. Thus, warning times can be relatively short, only a few months in some cases. Dynamical calculations show that the mean impact probability for Earth-crossing long-period comets is 2.2 x 10-9 per perihelion passage, assuming a uniform perihelion distribution and random inclination distribution for comets interior to 1 AU. The mean impact velocity is 51.8 km s-1, and the most probable impact velocity is 56.4 km s-1. For Jupiter-family comets, whose returns are predictable (once discovered), only 22 Earth-crossers are known (excluding the many fragments of 73P/Schwassmann-Wachmann 3). Of these, 4 are lost, 8 have only been observed on one return, and 1 is no longer Earth-crossing. Their mean impact probability is 7.3 x 10-9 per orbit or 1.3 x 10-9 per year, and their mean encounter velocity with the Earth is 22.9 km s-1, with a most probable encounter velocity of 19.9 km s-1. For Halley-type comets, whose returns are also predictable, another 16 Earth-crossers are known, of which 1 is lost and 6 have not yet made a second observed appearance. Their mean impact probability is 7.0 x 10-9 per orbit but only 0.16 x 10-9 per year because of their longer orbital periods. Their mean encounter velocity is 45.4 km s-1, with a most probable encounter velocity of 52.3 km s-1. Recent efforts at determining the size distribution of Jupiter-family comets has made it possible to estimate the actual impactor flux on the Earth. However, this is not true for Halley-type comets, where only a few nucleus radii have been reliably estimated, or for long-period comets where few if any reliable measurements exist. Additional

  10. Influence of Impactor Mass on the Damage Characteristics and Failure Strength of Laminated Composite Plates

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R.; Kemmerly, Heather L.

    1998-01-01

    The results of an experimental study of the effect of impactor mass on the low-speed impact response of laminated flat composite plates is presented. Dropped weight impact response, damage characteristics, and residual strengths of quasi-isotropic flat plates are presented for a range of energy levels by systematically varying the mass of the impactor. Measured contact forces and damage areas are also presented. The results indicate that the contact force and damage area are nonlinear functions of the impactor mass and vary considerably over the entire range of energy levels considered. The different damage levels induced in a plate specimen when impacted at a given energy level with impactors of different masses significantly influence its compressive residual strength. The results provide clear and consistent trends in contact force, damage area, and compression-after-impact strength when the data are expressed as a function of the impactor momentum.

  11. Two-dimensional virtual impactors. Final report

    SciTech Connect

    Forney, L.J.; Ravenhall, D.G.

    1980-12-01

    Theoretical predictions using both potential flow analyses and solutions to Navier-Stokes equations are made for the operating characteristics of a two-dimensional virtual impactor. Experiments were performed with 2.5 ..mu..m, uranine tagged, di-octylphthalate (DOP) oil droplets for a wide range of prototype geometries to measure the magnitude of internal losses and to fully characterize the instrument response. The influence of geometry including the throat angle (38/sup 0/ less than or equal to ..beta../sub 0/ less than or equal to 58.2/sup 0/) and normalized void width (0.7 less than or equal to h/w less than or equal to 1.5) on the particle cutoff diameter, efficiency curve steepness and properties of the internal particle loss factor are presented for fixed instrument Reynolds numbers Re = 1540 and bleed flow f = 0.1. The theory, supported by trends in the empirical data, predicts that internal particle losses reduce to zero as the normalized void width increases to h/w = 1.4 +- .1 while the data show a minimum at h/w = 1.6 +- .1. Increasing the void width, however, is shown to substantially reduce the steepness of the particle efficiency curves. Visual observations of the onset of fluid separation for two-dimensional jets impinging upon a void were conducted with a scaled-up water model and correlated with theory. It was found that the limiting void width h/sub lim//w marking the onset of fluid instabilities peaked for an intermediate value of the fluid deflecting plate angle ..beta.. approx. = 80/sup 0/ with larger values of h/sub lim//w corresponding to smaller throat angles ..beta../sub 0/. The limiting void width h/sub lim//w also increased with larger bleed flows into the void. These instabilities may make it difficult to correlate experimental virtual impactor data with theory.

  12. Coordinated Ground-Based and AIM Satellite Measurements of Mesospheric and Stratospheric Waves over South America

    NASA Astrophysics Data System (ADS)

    Taylor, M. J.; Zhao, Y.; Pautet, P. D.; Carstens, J. N.; Pugmire, J. R.; Smith, S. M.; Liu, A. Z.; Vargas, F.; Swenson, G. R.; Randall, C. E.; Bailey, S. M.; Russell, J. M., III

    2016-12-01

    To date, the primary research goals of the Aeronomy of Ice in the Mesosphere (AIM) satellite have focussed on investigating the occurrence, properties and dynamics of high-latitude Polar Mesospheric Clouds (PMC). With the evolution of the AIM orbit beta angle the opportunity now exists to make measurements outside the PMC region covering mid-low and equatorial latitudes. As part of the extended AIM mission science program, the AIM platform in conjunction with auxiliary ground-based measurements will be used to better understand upper atmospheric dynamics and vertical coupling due to gravity waves. Over the next 2 years AIM will take advantage of a new imaging capability of the on-board large-field CIPS UV imager to capture new data on the characteristics and spatial extents of stratospheric gravity waves near the 50 km level and their variation with latitude and season. In this study we report on initial coordinated ground-based measurements with the Andes Lidar Observatory (ALO) at Cerro Pachon, Chile ( 30°S) and nearby El Leoncito Observatory, Argentina, high in the Andes Mountains, where regular remote-sensing measurements are made using meteor radar, mesospheric airglow imagers, temperature mappers and an Na wind-temperature lidar (on a campaign basis). First coordinated measurements were made during the winter period in June 2016. AIM daytime overpasses have been analysed to search for and characterize extensive stratospheric wave events, as well as long-lived "Mountain Waves" over South America. Subsequent night-time ground-based measurements have been used to quantify wave characteristics in the mesopause region ( 80-100 km) to investigate vertical coupling. These measurements are continuing and it is planned to extend the new AIM stratospheric gravity wave data set for similar studies from a number of well-instrumented ground sites around the world.

  13. Size segregated ring pattern formation in particle impactors

    NASA Astrophysics Data System (ADS)

    Saylor, J. R.; Fredericks, S. A.

    2016-11-01

    Typical particle impactors consist of a nozzle that directs a particle laden flow onto a plate, and is designed to capture particles greater than a cutoff diameter. Connected in series as a cascade, with each impactor designed to have a progressively smaller cutoff diameter, the particle size distribution can be measured. Typical impactors utilize a nozzle-to-plate distance S that is on the order of one nozzle diameter W, S / W 1 , and give a nominally Gaussian particle deposition pattern on the plate. We explored conditions where S / W < < 1 and observed deposition patterns consisting of very fine rings. Moreover, we found that the ring diameter increased with decreasing particle diameter and the ring thickness increased with particle diameter. These results suggest a potential method for sizing particles by using the mature technology of impactors in a different way. Potential mechanisms for how these ring patterns are formed will be discussed. We note that prior studies have observed conditions where particle deposition patterns exhibited "halos". These halos appear less distinct than the rings we have observed, and it is unclear whether they are related.

  14. Air sampling of mold spores by slit impactors: yield comparison.

    PubMed

    Pityn, Peter J; Anderson, James

    2013-01-01

    The performance of simple slit impactors for air sampling of mold contamination was compared under field conditions. Samples were collected side-by-side, outdoors in quadruplicates with Burkhard (ambient sampler) and Allergenco MK3 spore traps and with two identical Allergenco slit cassettes operated at diverse flow rates of 5 and 15 L/min, respectively. The number and types of mold spores in each sample were quantified by microscopy. Results showed all four single-stage slit impactors produced similar spore yields. Moreover, paired slit cassettes produced similar outcomes despite a three-fold difference in their sampling rate. No measurable difference in the amount or mix of mold spores per m(3)of air was detected. The implications for assessment of human exposures and interpretation of indoor/outdoor fungal burden are discussed. These findings demonstrate that slit cassettes capture most small spores, effectively and without bias, when operated at a range of flow rates including the lower flow rates used for personal sampling. Our findings indicate sampling data for mold spores correlate for different single stage impactor collection methodologies and that data quality is not deteriorated by operating conditions deviating from manufacturers' norms allowing such sampling results to be used for scientific, legal, investigative, or property insurance purposes. The same conclusion may not be applied to other particle sampling instruments and mulit-stage impactors used for ambient particulate sampling, which represent an entirely different scenario. This knowledge may help facilitate comparison between scientific studies where methodological differences exist.

  15. Hypervelocity impact survivability experiments for carbonaceous impactors

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Becker, Luann; Bada, Jeffrey; Macklin, John; Radicatidibrozolo, Filippo; Fleming, R. H.; Erlichman, Jozef

    1993-01-01

    We performed a series of hypervelocity impact experiments using carbon-bearing impactors (diamond, graphite, fullerenes, phthalic acid crystals, and Murchison meteorite) into Al plate at velocities between 4.2 and 6.1 km/s. These tests were made to do the following: (1) determine the survivability of carbon forms and organize molecules in low hypervelocity impact; (2) characterize carbonaceous impactor residues; and (3) determine whether or not fullerenes could form from carbonaceous impactors, under our experimental conditions, or survive as impactors. An analytical protocol of field emission SEM imagery, SEM-EDX, laser Raman spectroscopy, single and 2-stage laser mass spectrometry, and laser induced fluorescence (LIF) found the following: (1) diamonds did not survive impact at 4.8 km/s, but were transformed into various forms of disordered graphite; (2) intact, well-ordered graphite impactors did survive impact at 5.9 km/sec, but were only found in the crater bottom centers; the degree of impact-induced disorder in the graphite increases outward (walls, rims, ejecta); (3) phthalic acid crystals were destroyed on impact (at 4.2 km/s, although a large proportion of phthalic acid molecules did survive impact); (4) fullerenes did not form as products of carbonaceous impactors (5.9 - 6.1 km/s, fullerene impactor molecules mostly survived impact at 5.9 km/s; and (5) two Murchison meteorite samples (launched at 4.8 and 5.9 km/s) show preservation of some higher mass polycyclic aromatic hydrocarbons (PAHs) compared with the non-impacted sample. Each impactor type shows unique impactor residue morphologies produced at a given impact velocity. An expanded methodology is presented to announce relatively new analytical techniques together with innovative modifications to other methods that can be used to characterize small impact residues in LDEF craters, in addition to other acquired extraterrestrial samples.

  16. Recognizing impactor signatures in the planetary record

    NASA Technical Reports Server (NTRS)

    Schultz, Peter H.; Gault, Donald E.

    1992-01-01

    Crater size reflects the target response to the combined effects of impactor size, density, and velocity. Isolating the effects of each variable in the cratering record is generally considered masked, if not lost, during late stages of crater modification (e.g., floor uplift and rim collapse). Important clues, however, come from the distinctive signatures of the impactor created by oblique impacts. In summary, oblique impacts allow for the identification of distinctive signatures of the impactor created during early penetration. Such signatures may further allow first-order testing of scaling relations for late crater excavation from the planetary surface record. Other aspects of this study are discussed.

  17. The Mass of Large Impactors

    NASA Technical Reports Server (NTRS)

    Parisi, M. G.; Brunini, A.

    1996-01-01

    By means of a simplified dynamical model, we have computed the eccentricity change in the orbit of each giant planet, caused by a single, large impact at the end of the accretion process. In order to set an upper bound on this eccentricity change, we have considered the giant planets' present eccentricities as primordial ones. By means of this procedure, we were able to obtain an implicit relation for the impactor masses and maximum velocities. We have estimated by this method the maximum allowed mass to impact Jupiter to be approx. 1.136 x 10(exp -1), being in the case of Neptune approx. 3.99 x 10(exp -2) (expressed in units of each planet final mass). Due to the similar present eccentricities of Saturn, Uranus and Jupiter, the constraint masses and velocities of the bodies to impact them (in units of each planet final mass and velocity respectively) are almost the same for the three planets. These results are in good agreement with those obtained by Lissauer and Safronov. These bounds might be used to derive the mass distribution of planetesimals in the early solar system.

  18. Organizational technologies for transforming care: measures and strategies for pursuit of IOM quality aims.

    PubMed

    Gamm, Larry; Kash, Bita; Bolin, Jane

    2007-01-01

    Progress on the Institute of Medicine's (IOM's) 6 aims to bridge the "quality chasm" requires both measurement and the concerting of multiple organizational technologies. The basic thesis of this article is that rapid progress on the IOM's multiple aims calls for transformative change within and among healthcare organizations. The promise of a number of types of transformative approaches is closely linked to their ability to simultaneously build upon several organizational technologies: clinical, social, information, and administrative technologies. To encourage and advance such efforts, this article identifies illustrative measures of attainment of the IOM's 6 aims or targeted areas for improvement that reflect the contributions of the 4 organizational technologies. It discusses examples of relationships between the IOM aims and the organizational technologies considered. Finally, the article offers illustrations of the interplay of these organizational technologies and IOM aims-across an array of organizational innovations with transformative potential. Included among such innovations are information technology in the form of electronic medical records, computer-based physician order entry, and patient health records; organization-wide patient-centered cultural change such as Studer's Hardwiring Excellence; Six Sigma and Toyota Production Management/LEAN; major clinical technology change, for example, minimally invasive cardiac surgery and broader treatment innovations such as disease management.

  19. Multi-Instrument Measurements of Noctilucent Clouds in Coordination with the AIM Satellite

    NASA Astrophysics Data System (ADS)

    Taylor, M. J.; Burton, D.; Tvedtnes-Barker, J.; Collins, R. L.; Thurairajah, B.; Rusch, D.; Russell, J.; Heinselman, C.; Nicolls, M.; Zalcik, M.

    2007-12-01

    With the recent launch of the NASA Aeronomy of Ice in the Mesosphere (AIM) satellite in April 2007 the opportunity exists to perform novel coordinated satellite and ground-based measurements of noctilucent clouds (NLC), to better quantify their nature, temporal development, latitudinal extent and longitudinal variability. These measurements will also help shed new light on the long-standing question on the differences (if any) between NLC, which are naturally limited in their observation to latitude ranges of typically 50-65°, and Polar Mesospheric Clouds (PMC) as detected at higher latitudes during the summer months from space borne instruments. Here we present new two-station image measurements of NLC from Edmonton, Canada (53° N) recorder during July 2007, providing detailed information on the cloud dynamics near their equatorward edge, for comparison with the UV cloud signatures as determined by the Cloud Imaging and Particle Size (CIPS) instrument on the AIM satellite. These results are then contrasted with high-latitude (65°N) cloud measurements using AIM in coordination with multi-station imager, lidar and radar observations of Polar Mesospheric Summer Echoes (PMSE) using the new PFISR system at Poker Flat, Alaska.

  20. Physicochemical Characterization of Cloud Drop Residual Particles in Eastern Pacific Marine Stratocumulus: Airborne Measurements Downstream of a Newly-Developed Counterflow Virtual Impactor Inlet during the 2011 E-PEACE Campaign

    NASA Astrophysics Data System (ADS)

    Sorooshian, A.; Shingler, T.; Dey, S.; Brechtel, F. J.; Jonsson, H.; Metcalf, A. R.; Craven, J. S.; Coggon, M.; Lin, J. J.; Nenes, A.; Seinfeld, J.

    2011-12-01

    The aerosol nuclei that are the seeds of cloud drops are a critically important component of the atmosphere as they influence radiative transfer, visibility, and cloud microphysics. Aircraft must employ special inlets to exclusively sample cloud drops, which involves rejecting the smaller interstitial aerosol in clouds, and then subsequently drying the drops to leave only the residual particles. A new counterflow virtual impactor inlet (CVI) was recently deployed on the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE). Several state-of-the-art instruments sampling downstream of the CVI characterized the physical and chemical properties of the droplet residual particles including measurements of composition, size distribution, optical properties, and water-uptake properties. This work will summarize CVI measurements from over 25 flights during the E-PEACE campaign off the central coast of California between July and August. The flights specifically targeted aerosol-cloud interactions in a region where stratocumulus clouds are perturbed by emissions from ship traffic. New findings related to the physicochemical properties of drop residual particles will be highlighted in addition to a characterization of CVI performance.

  1. Impactor flux and cratering on the Pluto-Charon system

    NASA Astrophysics Data System (ADS)

    de Elía, G. C.; di Sisto, R. P.; Brunini, A.

    2010-10-01

    Aims: We study the impactor flux and cratering on Pluto and Charon caused by the collisional evolution of Plutinos. Plutinos are trans-Neptunian objects located at ~39.5 AU, in the 3:2 mean motion resonance with Neptune. Methods: We develop a statistical code that includes catastrophic collisions and cratering events, and takes into account the stability and instability zones of the 3:2 mean motion resonance with Neptune. Our numerical algorithm proposes different initial populations that account for the uncertainty in the size distribution of Plutinos at small sizes. Results: Depending on the initial population, our results indicate the following. The number of D > 1 km Plutinos streaking Pluto over 3.5 Gyr is between 1271 and 5552. For Charon, the number of D > 1 km Plutino impactors is between 354 and 1545. The number of D > 1 km craters on Pluto produced by Plutinos in the past 3.5 Gyr is between 43 076 and 113 879. For Charon, the number of D > 1 km craters is between 20 351 and 50 688. On the other hand, the largest Plutino impactor onto Pluto has a diameter of between ~17 and 23 km, which produces a crater with a diameter of ~31-39 km. In the same way, the largest Plutino impactor onto Charon has a diameter of between ~10 and 15 km, which produces a crater with a diameter of ~24-33 km. Finally, we test the dependence of results on the number of Pluto-sized objects in the Plutino population. If two Pluto-sized objects are assumed in the 3:2 Neptune resonance, the total number of Plutino impactors onto both Pluto and Charon with diameters D > 1 km is a factor of ~1.6-1.8 larger than that obtained considering only one Pluto-sized object in this resonant region. Conclusions: Given the structure of the trans-Neptunian region, with its dynamically different populations, it is necessary to study in detail the contribution of all the potential sources of impactors onto the Pluto-Charon system, to determine the main contributor and the whole production of craters

  2. Relative precision of inhaler aerodynamic particle size distribution (APSD) metrics by full resolution and abbreviated andersen cascade impactors (ACIs): part 1.

    PubMed

    Mitchell, Jolyon P; Nagel, Mark W; Doyle, Cathy C; Ali, Rubina S; Avvakoumova, Valentina I; Christopher, J David; Quiroz, Jorge; Strickland, Helen; Tougas, Terrence; Lyapustina, Svetlana

    2010-06-01

    The purpose of this study was to compare relative precision of two different abbreviated impactor measurement (AIM) systems and a traditional multi-stage cascade impactor (CI). The experimental design was chosen to provide separate estimates of variability for each impactor type. Full-resolution CIs are useful for characterizing the aerosol aerodynamic particle size distribution of orally inhaled products during development but are too cumbersome, time-consuming, and resource-intensive for other applications, such as routine quality control (QC). This article presents a proof-of-concept experiment, where two AIM systems configured to provide metrics pertinent to QC (QC-system) and human respiratory tract (HRT-system) were evaluated using a hydrofluoroalkane-albuterol pressurized metered dose inhaler. The Andersen eight-stage CI (ACI) served as the benchmark apparatus. The statistical design allowed estimation of precision with each CI configuration. Apart from one source of systematic error affecting extra-fine particle fraction from the HRT-system, no other bias was detected with either abbreviated system. The observed bias was shown to be caused by particle bounce following the displacement of surfactant by the shear force of the airflow diverging above the collection plate of the second impaction stage. A procedure was subsequently developed that eliminated this source of error, as described in the second article of this series (submitted to AAPS PharmSciTech). Measurements obtained with both abbreviated impactors were very similar in precision to the ACI for all measures of in vitro performance evaluated. Such abbreviated impactors can therefore be substituted for the ACI in certain situations, such as inhaler QC or add-on device testing.

  3. Brookhaven air infiltration measurement system (BNL/AIMS) description and application

    SciTech Connect

    Dietz, R.N.; Goodrich, R.W.; Cote, E.A.; Wieser, R.F.

    1983-08-01

    A unique capability to measure part-per-quadrillion concentrations of a family of perfluorocarbon tracers (PFTs) is presented. Together with our unique PFT source and passive sampler, measurement of average air exchange and infiltration rate can be determined for periods as short as 12 hours. A more expensive programmable sampler can provide information on a frequency of as little as once per minute for each of its 23 sampling tubes. The principal of AIMS is based on the applicable steady-state assumption that the average concentration (e.g., in pL/L) of a tracer vapor in a chamber (i.e., a building or room) is equal to the emission rate of the tracer source (e.g., in pL/min) divided by the air leakage or infiltration rate (e.g., in L/min). Knowing the source rate and measuring the average concentration then provides a means to calculate the air leakage rate. Extending this technique to a multichamber concept, in which a different type of PFT source is deployed in each chamber of a building, allows the calculation of not only the infiltration rates in each chamber but also the air exchange rates between chambers as well. Since both the PFT source and the passive sampler, a miniature Capillary Adsorption Tube Sampler (CATS), are about the size of a cigarette, inexpensive, and reusable, the BNL/AIMS is a very cost-effective means (if not the only means) for determining these air exchange rates.

  4. SPOrt: an experiment aimed at measuring the large scale cosmic microwave background polarization

    NASA Astrophysics Data System (ADS)

    Carretti, Ettore; Cortiglioni, Stefano; Bernardi, Gianni; Cecchini, Stefano; Macculi, Claudio; Sbarra, Carla; Monari, Jader; Orfei, Alessandro; Poloni, Marco; Poppi, Sergio; Boella, Giuliano; Bonometto, Silvio; Gervasi, Massimo; Sironi, Giorgio; Zannoni, Mario; Tucci, Marco; Baralis, Massino; Peverini, Oscar A.; Tascone, Riccardo; Virone, Giuseppe; Fabbri, Roberto; Nicastro, Luciano; Ng, Kin-Wang; Razin, V. A.; Vinyajkin, Evgenij N.; Sazhin, Mikhail V.; Strukov, Igor A.

    2003-02-01

    SPOrt (Sky Polarization Observatory) is a space experiment to be flown on the International Space Station during Early Utilization Phase aimed at measuring the microwave polarized emission with FWHM = 7 deg, in the frequency range 22-90 GHz. The Galactic polarized emission can be observed at the lower frequencies and the polarization of Cosmic Microwave Background (CMB) at 90 GHz, where contaminants are expected to be less important. The extremely low level of the CMB Polarization signal calls for intrinsically stable radiometers. The SPOrt instrument is expressly devoted to CMB polarization measurements and the whole design has been optimized for minimizing instrumental polarization effects. In this contribution we present the receiver architecture based on correlation techniques, the analysis showing its intrinsic stability and the custom hardware development carried out to detect such a low signal.

  5. Characteristics of cascade impactors in size determination of diesel particles

    NASA Astrophysics Data System (ADS)

    Chan, Tai L.; Lawson, Douglas R.

    Cascade impactors of various designs have been used extensively in air sampling and inhalation toxicology to determine the size distribution of airborne aerosols. In this study, the internal losses of diesel exhaust particles in a multijet Mercer impactor, a low pressure Battelle impactor, and an Anderson impactor were determined by scintillation counting of gamma tagged diesel particles. Total interstage losses were 8-33%. However, losses in the three impactors were comparable on stages where most of the mass was found, ranging from 17 to 25%. Apiezon and Vaseline coated impaction surfaces reduced the internal losses of diesel particles and yielded larger mass median aerodynamic diameters compared to the uncoated impactors.

  6. The micro-orifice uniform deposit impactor-droplet freezing technique (MOUDI-DFT) for measuring concentrations of ice nucleating particles as a function of size: improvements and initial validation

    NASA Astrophysics Data System (ADS)

    Mason, R. H.; Chou, C.; McCluskey, C. S.; Levin, E. J. T.; Schiller, C. L.; Hill, T. C. J.; Huffman, J. A.; DeMott, P. J.; Bertram, A. K.

    2015-02-01

    The micro-orifice uniform deposit impactor-droplet freezing technique (MOUDI-DFT) combines particle collection by inertial impaction (via the MOUDI) and a microscope-based immersion freezing apparatus (the DFT) to measure atmospheric concentrations of ice nucleating particles (INPs) as a function of size and temperature. In the first part of this study we improved upon this recently introduced technique. Using optical microscopy, we investigated the non-uniformity of MOUDI aerosol deposits at spatial resolutions of 1, 0.25 mm, and for some stages when necessary 0.10 mm. The results from these measurements show that at a spatial resolution of 1 mm and less, the concentration of particles along the MOUDI aerosol deposit can vary by an order of magnitude or more. Since the total area of a MOUDI aerosol deposit ranges from 425 to 605 mm2 and the area analyzed by the DFT is approximately 1.2 mm2, this non-uniformity needs to be taken into account when using the MOUDI-DFT to determine atmospheric concentrations of INPs. Measurements of the non-uniformity of the MOUDI aerosol deposits were used to select positions on the deposits that had relatively small variations in particle concentration and to build substrate holders for the different MOUDI stages. These substrate holders improve reproducibility by holding the substrate in the same location for each measurement and ensure that DFT analysis is only performed on substrate regions with relatively small variations in particle concentration. In addition, the deposit non-uniformity was used to determine correction factors that take the non-uniformity into account when determining atmospheric concentrations of INPs. In the second part of this study, the MOUDI-DFT utilizing the new substrate holders was compared to the continuous flow diffusion chamber (CFDC) technique of Colorado State University. The intercomparison was done using INP concentrations found by the two instruments during ambient measurements of continental

  7. The micro-orifice uniform deposit impactor-droplet freezing technique (MOUDI-DFT) for measuring concentrations of ice nucleating particles as a function of size: improvements and initial validation

    NASA Astrophysics Data System (ADS)

    Mason, R. H.; Chou, C.; McCluskey, C. S.; Levin, E. J. T.; Schiller, C. L.; Hill, T. C. J.; Huffman, J. A.; DeMott, P. J.; Bertram, A. K.

    2015-06-01

    The micro-orifice uniform deposit impactor-droplet freezing technique (MOUDI-DFT) combines particle collection by inertial impaction (via the MOUDI) and a microscope-based immersion freezing apparatus (the DFT) to measure atmospheric concentrations of ice nucleating particles (INPs) as a function of size and temperature. In the first part of this study we improved upon this recently introduced technique. Using optical microscopy, we investigated the non-uniformity of MOUDI aerosol deposits at spatial resolutions of 1, 0.25 mm, and for some stages when necessary 0.10 mm. The results from these measurements show that at a spatial resolution of 1 mm and less, the concentration of particles along the MOUDI aerosol deposits can vary by an order of magnitude or more. Since the total area of a MOUDI aerosol deposit ranges from 425 to 605 mm2 and the area analyzed by the DFT is approximately 1.2 mm2, this non-uniformity needs to be taken into account when using the MOUDI-DFT to determine atmospheric concentrations of INPs. Measurements of the non-uniformity of the MOUDI aerosol deposits were used to select positions on the deposits that had relatively small variations in particle concentration and to build substrate holders for the different MOUDI stages. These substrate holders improve reproducibility by holding the substrate in the same location for each measurement and ensure that DFT analysis is only performed on substrate regions with relatively small variations in particle concentration. In addition, the deposit non-uniformity was used to determine correction factors that take the non-uniformity into account when determining atmospheric concentrations of INPs. In the second part of this study, the MOUDI-DFT utilizing the new substrate holders was compared to the continuous flow diffusion chamber (CFDC) technique of Colorado State University. The intercomparison was done using INP concentrations found by the two instruments during ambient measurements of continental

  8. Version 1.3 AIM SOFIE measured methane (CH4): Validation and seasonal climatology

    NASA Astrophysics Data System (ADS)

    Rong, P. P.; Russell, J. M.; Marshall, B. T.; Siskind, D. E.; Hervig, M. E.; Gordley, L. L.; Bernath, P. F.; Walker, K. A.

    2016-11-01

    The V1.3 methane (CH4) measured by the Aeronomy of Ice in the Mesosphere (AIM) Solar Occultation for Ice Experiment (SOFIE) instrument is validated in the vertical range of 25-70 km. The random error for SOFIE CH4 is 0.1-1% up to 50 km and degrades to 9% at ˜ 70 km. The systematic error remains at 4% throughout the stratosphere and lower mesosphere. Comparisons with CH4 data taken by the SCISAT Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) and the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) show an agreement within 15% in the altitude range 30-60 km. Below 25 km SOFIE CH4 is systematically higher (≥20%), while above 65 km it is lower by a similar percentage. The sign change from the positive to negative bias occurs between 55 km and 60 km (or 40 km and 45 km) in the Northern (or Southern) Hemisphere. Methane, H2O, and 2CH4 + H2O yearly differences from their values in 2009 are examined using SOFIE and MIPAS CH4 and the Aura Microwave Limb Sounder (MLS) measured H2O. It is concluded that 2CH4 + H2O is conserved with altitude up to an upper limit between 35 km and 50 km depending on the season. In summer this altitude is higher. In the Northern Hemisphere the difference relative to 2009 is the largest in late spring and the established difference prevails throughout summer and fall, suggesting that summer and fall are dynamically quiet. In both hemispheres during winter there are disturbances (with a period of 1 month) that travel downward throughout the stratosphere with a speed similar to the winter descent.

  9. Atmospheric behavior of the Chelyabinsk impactor

    NASA Astrophysics Data System (ADS)

    Borovička, J.; Spurný, P.; Brown, P.; Kalenda, P.; Shrbený, L.

    2014-07-01

    The impact of a 19-m diameter asteroid near Chelyabinsk, Russia on February 15, 2013 has already been studied extensively [e.g., 1--3]. The main sources of information were casually recorded videos, which provided the images of the superbolide as well as acoustic records of the sonic booms. From these data, the bolide trajectory, velocity, deceleration, and lightcurve have been derived after careful calibration and analysis. Such detailed data are not available for any other impactor larger than about 5 meters. The Chelyabinsk event represents therefore a unique opportunity to study the interaction of asteroids in the decameter size range through the terrestrial atmosphere. In comparison with our previous study [1], we used more calibrated videos in this work. We will present the refined trajectory, velocity, and orbit but will mainly concentrate on the atmospheric fragmentation analysis. The extent of the dust trail up to the heights of 70 km demonstrates that significant mass loss occurred from the early parts of the luminous trajectory. Nevertheless, no flare was seen on the early portion of the lightcurve, suggesting that no sudden disruption occurred here and the mass was probably being lost from the asteroid surface. The first break-up occurred at the height of about 47 km. The large scale disruption, documented both by the lightcurve and sonic booms, occurred between the heights of 39--30 km. The fragmentation then ceased temporarily, but a number of surviving meter-sized boulders fragmented extensively again below 26 km. We will present a fragmentation model fitting both the observed lightcurve and deceleration. At lower heights, the deceleration of several individual fragments could be measured. The transverse speed of the major fragment was 400 m/s, much larger than expected, but of the same order of magnitude as observed in other cases including a sample of tiny meteoroids [4]. The unique aspect of Chelyabinsk was the formation of an extended dust trail

  10. National Residential Efficiency Measures Database Aimed at Reducing Risk for Residential Retrofit Industry

    SciTech Connect

    David Roberts

    2012-01-01

    This technical highlight describes NREL research to develop a publicly available database of energy retrofit measures containing performance characteristics and cost estimates for nearly 3,000 measures.

  11. Piloting the AIM Project: Measuring Progress for Program Evaluation and Accountability.

    ERIC Educational Resources Information Center

    Mundie, Karen; Thompson, Debbie; Joyce, Michelle

    The AIM (Assessment, Instruction, Mastery) system is a performance-based assessment that was developed in Oregon. The AIM system was piloted by 83 volunteers and staff from 18 volunteer-based programs to assess the system's usefulness as a means of collecting and aggregating data on student progress in adult literacy and similar programs in…

  12. Evaluation of an integrated adherence program aimed to increase Medicare Part D star rating measures.

    PubMed

    Leslie, R Scott; Tirado, Breanne; Patel, Bimal V; Rein, Philip J

    2014-12-01

    star to 2 stars for HTN), which contributed to increases in the Drug Plan Quality Improvement measure (2 stars to 4 stars) and iCare's overall Part D star rating (3 to 3.5 stars).  Members in this MA-PD plan dual-eligible population benefited from multiple points of contact to achieve increased adherence. Health plans can use network pharmacies, care management staff, and their pharmacy benefits managers to collaborate and implement interventions aimed to improve members' adherence to targeted maintenance medications and overall health plan quality performance and star ratings.

  13. Evaluation of an abbreviated impactor for fine particle fraction (FPF) determination of metered dose inhalers (MDI).

    PubMed

    Guo, Changning; Ngo, Diem; Ahadi, Shafiq; Doub, William H

    2013-09-01

    Abbreviated impactors have been developed recently to allow more rapid evaluation of inhalation products as alternates to the eight-stage Andersen Cascade Impactor (ACI) which has been widely used in the pharmaceutical industry for assessing aerodynamic particle size distribution. In this paper, a two-stage abbreviated impactor, Westech Fine Particle Dose Impactor (WFPD), was used to characterize the aerodynamic particle size of metered dose inhaler (MDI) products, and the results were compared with those obtained using the standard eight-stage ACI. Seven commercial MDI products, with different propellants (chlorofluorocarbon/hydrofluoroalkane) and formulation types (suspension/solution, dry/normal/wet), were tested in this study by both WFPD and ACI. Substantially equivalent measures of fine particle fraction were obtained for most of the tested MDI products, but larger coarse particle fraction and extra-fine particle fraction values were measured from WFPD relative to those measured using the ACI. Use of the WFPD also produced more wall loss than the ACI. Therefore, it is recommended that the system suitability be evaluated on a product-by-product basis to establish substantial equivalency before implementing an abbreviated impactor measurement methodology for routine use in inhaler product characterization.

  14. Measuring Motivation Multidimensionally: Development of the Assessment of Individual Motives-Questionnaire (AIM-Q)

    ERIC Educational Resources Information Center

    Bernard, Larry C.; Mills, Michael; Swenson, Leland; Walsh, R. Patricia

    2008-01-01

    We report the development of the Assessment of Individual Motives-Questionnaire (AIM-Q), a new instrument based on an evolutionary psychology theory of human motivation. It provides multitrait-multimethod (MTMM) assessment of individual differences on 15 motive scales. A total heterogeneous sample of N = 1,251 participated in eight studies that…

  15. Applying Athletic Identify Measurement Scale on Physical Educators: Turkish Version of AIMS

    ERIC Educational Resources Information Center

    Tunçkol, H. Mehmet

    2015-01-01

    In sports research, defining athletic identity of individuals is an important study subject. The subject owes its significance to the fact that an individual's athletic identity affects his other identities throughout his life span. The aim of this study is to test the reliability and validity of the Turkish version of Athletic Identity…

  16. Applying Athletic Identify Measurement Scale on Physical Educators: Turkish Version of AIMS

    ERIC Educational Resources Information Center

    Tunçkol, H. Mehmet

    2015-01-01

    In sports research, defining athletic identity of individuals is an important study subject. The subject owes its significance to the fact that an individual's athletic identity affects his other identities throughout his life span. The aim of this study is to test the reliability and validity of the Turkish version of Athletic Identity…

  17. Pilot Program Aims High: Challenges en Route Help District Find Success in Measuring Impact

    ERIC Educational Resources Information Center

    Celeste, Eric

    2017-01-01

    Denver Public Schools' Professional Learning Center was still relatively new when it decided to tackle a problem of practice that has vexed systems and departments across the country: How to measure the impact of professional learning. To do so, the Professional Learning Center created a new comprehensive measurement approach--one that would…

  18. National Residential Efficiency Measures Database Aimed at Reducing Risk for Residential Retrofit Industry (Fact Sheet)

    SciTech Connect

    Not Available

    2012-01-01

    This technical highlight describes NREL research to develop a publicly available database of energy retrofit measures containing performance characteristics and cost estimates for nearly 3,000 measures. Researchers at the U.S. Department of Energy (DOE) National Renewable Energy Laboratory (NREL) have developed the National Residential Efficiency Measures Database, a public database that characterizes the performance and costs of common residential energy efficiency measures. The data are available for use in software programs that evaluate cost-effective retrofit measures to improve the energy efficiency of residential buildings. The database provides a single, consistent source of current data for DOE and private-sector energy audit and simulation software tools and the retrofit industry. The database will reduce risk for residential retrofit industry stakeholders by providing a central, publicly vetted source of up-to-date information.

  19. Increasing active travel: aims, methods and baseline measures of a quasi-experimental study.

    PubMed

    Chapman, Ralph; Howden-Chapman, Philippa; Keall, Michael; Witten, Karen; Abrahamse, Wokje; Woodward, Alistair; Muggeridge, Dylan; Beetham, Jean; Grams, Mark

    2014-09-08

    Policy advisers are seeking robust evidence on the effectiveness of measures, such as promoting walking and cycling, that potentially offer multiple benefits, including enhanced health through physical activity, alongside reductions in energy use, traffic congestion and carbon emissions. This paper outlines the 'ACTIVE' study, designed to test whether the Model Communities Programme in two New Zealand cities is increasing walking and cycling. The intervention consists of the introduction of cycle and walkway infrastructure, along with measures to encourage active travel. This paper focuses on the rationale for our chosen study design and methods. The study design is multi-level and quasi-experimental, with two intervention and two control cities. Baseline measures were taken in 2011 and follow-up measures in 2012 and 2013. Our face-to-face surveys measured walking and cycling, but also awareness, attitudes and habits. We measured explanatory and confounding factors for mode choice, including socio-demographic and well-being variables. Data collected from the same households on either two or three occasions will be analysed using multi-level models that take account of clustering at the household and individual levels. A cost-benefit analysis will also be undertaken, using our estimates of carbon savings from mode shifts. The matching of the intervention and control cities was quite close in terms of socio-demographic variables, including ethnicity, and baseline levels of walking and cycling. This multidisciplinary study provides a strong design for evaluating an intervention to increase walking and cycling in a developed country with relatively low baseline levels of active travel. Its strengths include the use of data from control cities as well as intervention cities, an extended evaluation period with a reasonable response rate from a random community survey and the availability of instrumental variables for sensitivity analyses.

  20. An optical technique for measuring divergence, beam profile, and aiming direction, of relativistic negative hydrogen ions

    SciTech Connect

    Hershcovitch, A.

    1988-02-01

    A novel, nonobstructive diagnostic technique for high energy H/sup minus/D/sup minus/ ion beams is described. This scheme employs spectroscopic techniques designed to measure beam profile, perpendicular velocity spread (i.e., divergence), and orientation of multiMeV H/sup minus/ beams. The basic principle of this method is to photoneutralize a small portion of the H/sup minus/ beam in a way such that the photodetachment process results in the formation of excited hydrogen atoms in the n = 2 levels. Observation of fluorescence from spontaneous decay of H(sp) andor induced deacy of H(2s) can be readily used to determine beam profile. Doppler broadening measurements can be used to determine velocity spread from which beam emittance is calculated. With off-the-shelf instruments resolutions of 1 mm for beam profile and 2 x 10/sup minus/2) ..pi.. cm-mrad are possible. For photodetachment, the best commercially available laser is found to be ArF eximer laser. The analysis is performed for the 200 MEV BNL Linac. The laser, which has a pulse duration which has a pulse duration which is of 10/sup minus/5) of the linac can produce sufficient signal at a negligible beam loss. In addition, measurements of minute Doppler shifts of this Lyman-Alpha radiation by a spectrograph could in principle resolve beam direction to within 1.57 ..mu..rad. The process under consideration has a resonance known as the shape resonance. As the following literature review indicates, the total cross section is known and there is a reasonable agreement between theory and experiment. There are no experimental measurements of partical cross sections. nevertheless, there are theoretical estimates which agree within 15%. 10 refs., 1 fig.

  1. Application of heated inlet extensions to the TSI 3306/3321 system: comparison with the Andersen cascade impactor and next generation impactor.

    PubMed

    Myrdal, Paul B; Mogalian, Erik; Mitchell, Jolyon; Nagel, Mark; Wright, Charlie; Kiser, Brent; Prell, Mark; Woessner, Mike; Stein, Stephen W

    2006-01-01

    Pharmaceutical aerosol size distribution analysis based on multi-stage inertial impaction is well accepted, though laborious. The TSI 3306 Impactor Inlet/3321 time-of-flight (TOF) Aerodynamic Particle Size Analyzer (APS) has been evaluated for its ease of use and potential for time savings during product development. However, instrument inlet modifications may be necessary for increased correlation with equivalent measurements obtained by inertial impaction following pharmacopeial methods. A heated inlet extension tube was located between the USP/Ph.Eur. throat and the Single-Stage Impactor (SSI) to promote evaporation of residual ethanol from aerosol droplets, generated from two formulations containing ethanol as semi-volatile solubilizer (8 and 20% w/w) for the active pharmaceutical ingredient. As temperature and extension length increased, the SSI-measured fine particle fraction (aerosol < 4.7 microm aerodynamic diameter) also increased, for the aerosols used in this study. These values correlated quite closely with equivalent measures made by multi-stage cascade impactor equipped with the same throat. Particle size distribution profiles measured with the APS for either formulation did not significantly change utilizing the heated extensions, suggesting that ethanol evaporation was largely complete at any condition by the time the aerosol entered the measurement zone of the TOF analyzer. The addition of a heated inlet extension may be useful to facilitate evaporation of residual semi-volatile species, especially when an agreement of APS-derived particle size mass distribution data from the SSI with multi-stage cascade impactors is desired. However, complete evaporation of the semi-volatile species may not be necessary for SSI-generated mass distribution to match conventionally used cascade impactors.

  2. Fusarium oxysporum infection of stasis ulcer: eradication with measures aimed to improve stasis.

    PubMed

    Mansur, A Tülin; Artunkal, Seza; Ener, Beyza

    2011-07-01

    Fusarium species may cause localised skin infections in immunocompetent individuals. At least half of these infections are preceded by skin breakdown. The lesions are characterised by slow progression and good response to therapy. Here we present a 60-year-old non-diabetic man with stasis ulcers showing Fusarium oxysporum growth in culture of both pus swabs and skin biopsy specimens. The patient was confined to wheelchair because of recurrent sacral chordoma of 15 years duration, which was not under treatment for the last 3 years. Leg ulcers were resistant to antifungal therapy, and healed rapidly after improving of stasis with local and systemic measures.

  3. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  4. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  5. Aspects on Feed Related Prophylactic Measures Aiming to Prevent Post Weaning Diarrhoea in Pigs

    PubMed Central

    Melin, L; Wallgren, P

    2002-01-01

    The ability of feed related measures to prevent or reduce post weaning diarrhoea (PWD) was examined in a split litter study including 30 pigs from 6 litters allotted into 5 groups. Four groups were exposed to 3 pathogenic strains of E. coli via the environment at weaning. Three of them were given zinc oxide, lactose+fibres or non-pathogenic strains of E. coli as probiotics. The challenged and the unchallenged control groups were given a standard creep feed. Diarrhoea was observed in all challenged groups but not among uninfected animals, and the incidence of diarrhoea was lower in the group given non-pathogenic E. coli compared to all other challenged groups. The severity of PWD also differed between litters. When corrected for mortality due to PWD, a decreased incidence of diarrhoea was also seen in the groups given zinc oxide or lactose+fibres. The dominating serotype of E. coli within faecal samples varied from day to day, also among diarrhoeic pigs, indicating that diarrhoea was not induced by one single serotype alone. The diversity of the faecal coliform populations decreased in all piglets during the first week post weaning, coinciding with an increased similarity between these populations among pigs in the challenged groups. This indicated an influence of the challenge strains, which ceased during the second week. The group given lactose+fibres was least affected with respect to these parameters. In conclusion feed related measures may alleviate symptoms of PWD. PMID:12831176

  6. Rapid impactor sample return (RISR) mission scenario

    NASA Astrophysics Data System (ADS)

    Walker, James D.; Freitas, Christopher J.; Tapley, Mark B.

    2004-01-01

    Due to the long lead time and great expense of traditional sample return mission plans to Mars or other astronomical bodies, there is a need for a new and innovative way to return materials, potentially at a lower cost. The Rapid Impactor Sample Return (RISR) mission is one such proposal. The general mission scenario involves a single pass of Mars, a Martian moon or an asteroid at high speeds (7 km/s), with the sample return vehicle skimming just 1 or 2 m above a high point (such as a top ridge on Olympus Mons on Mars) and releasing an impactor. The impactor strikes the ground, throwing up debris. The debris with roughly the same forward velocity will be captured by the sample return vehicle and returned to Earth. There is no delay or orbit in the vicinity of Mars or the asteroid: RISR is a one-pass mission. This paper discusses some of the details of the proposal. Calculations are presented that address the question of how much material can be recovered with this technique. There are concerns about the effect of Mars tenuous atmosphere. However, it will be noted that such issues do not occur for RISR style missions to Phobos, Deimos, or asteroids and Near Earth Objects (NEOs). Recent test results in the missile defense community (IFTs 6-8 in 2001, 2002) have scored direct hits at better than 1 m accuracy with closing velocities of 7.6 km/s, giving the belief that accuracy and sensing issues are developed to a point that the RISR mission scenario is feasible.

  7. La masa de los grandes impactores

    NASA Astrophysics Data System (ADS)

    Parisi, M. G.; Brunini, A.

    Los planetas han sido formados fundamentalmente acretando masa a través de colisiones con planetesimales sólidos. La masa más grande de la distribución de planetesimales y las masas máxima y mínima de los impactores, han sido calculadas usando los valores actuales del período y de la inclinación de los planetas (Lissauer & Safronov 1991; Parisi & Brunini 1996). Recientes investigaciones han mostrado, que las órbitas de los planetas gigantes no han sufrido variaciones con el tiempo, siendo su movimiento regular durante su evolución a partir de la finalización de la etapa de acreción (Laskar 1990, 1994). Por lo tanto, la eccentricidad actual de los planetas gigantes se puede utilizar para imponer una cota máxima a las masas y velocidades orbitales de los grandes impactores. Mediante un simple modelo dinámico, y considerando lo arriba mencionado, obtenemos la cota superior para la masa del planetesimal más grande que impactó a cada planeta gigante al final de su etapa de acreción. El resultado más importante de este trabajo es la estimación de la masa máxima permitida para impactar a Júpiter, la cúal es ~ 1.136 × 10 -1, siendo en el caso de Neptuno ~ 3.99 × 10 -2 (expresada en unidades de la masa final de cada planeta). Además, fue posible obtener la velocidad orbital máxima permitida para los impactores como una función de su masa, para cada planeta. Las cotas obtenidas para la masa y velocidad de los impactores de Saturno y Urano (en unidades de la masa y velocidad final de cada planeta respectivamente) son casi las mismas que las obtenidas para Júpiter debido a que estos tres planetas poseen similar eccentricidad actual. Nuestros resultados están en buen acuerdo con los obtenidos por Lissauer & Safronov (1991). Estas cotas podrían ser utilizadas para obtener la distribución de planetesimales en el Sistema Solar primitivo.

  8. Cascade impactor and jet plate for same

    DOEpatents

    Dahlin, Robert S.; Farthing, William E.; Landham Jr., Edward C.

    2004-02-03

    A sampling system and method for sampling particulate matter from a high-temperature, high-pressure gas stream. A cyclone sampler for use at high temperatures and pressures, and having threadless sacrificial connectors is disclosed. Also disclosed is an improved cascade impactor including jet plates with integral spacers, and alignment features provided for aligning the jet plates with their associated collection substrates. An activated bauxite alkali collector is disclosed, and includes an alumina liner. The sampling system can be operated remotely or locally, and can be permanently installed or configured as a portable system.

  9. The Relationship among Measures of Written Expression Using Curriculum-Based Measurement and the Arizona Instrument to Measure Skills (AIMS) at the Middle School Level

    ERIC Educational Resources Information Center

    Lopez, Francesca A.; Thompson, Sandra S.

    2011-01-01

    The authors examined the predictor-criterion relationship between measures of written expression using spring curriculum-based measures (W-CBM) and the spring administration of the state-mandated high-stakes test the Arizona Instrument to Measure Standards (AIMS) in writing. Students (N = 83) in Grades 6, 7, and 8 wrote expressive narratives for 3…

  10. Calibration and evaluation of a real-time cascade impactor

    SciTech Connect

    Fairchild, C.I.; Wheat, L.D.

    1984-04-01

    A 10-stage cascade impactor made by California Measurement Inc., can determine aerodynamic size distributions of dilute aerosols in a few minutes. Collection of impacted particles on greased, vibrating piezoelectric crystals produces changes in vibrational frequency proportional to the collected mass. Based on frequency changes and sampling time, a data reduction module calculates the mass collected on each stage. Calibration of the assembled impactor was performed with monodisperse polystyrene latex (PSL) and Eosin-Y (E-Y) aerosols for the lower stages (4-10), and PSL and pollen particles (ragweed and mulberry) for the upper stages (1-3). The stage experimental effective cutoff aerodynamic diameters (ECAD) were up to 22 percent different from theoretical ECADs with the exception of Stages 1 and 2 which were respectively 30 and 35 percent different from theoretical ECADs. The overall loss of particles > 3- and < 0.3-..mu..m was severe. Also, considerable scatter of particles was observed on the collection crystals of Stages 1 and 2. Although a majority of particles were in the impaction area, a large fraction was scattered over the outer portions of these crystals.

  11. Are changes in weather masking the efficacy of measures aimed at mitigating diffuse pollution?

    NASA Astrophysics Data System (ADS)

    Mellander, Per-Erik; Jordan, Phil; Shore, Mairead; McDonald, Noeleen; Shortle, Ger

    2016-04-01

    Interpretations of the efficacy of mitigation measures for reducing nitrogen (N) and phosphorus (P) losses from agricultural sources to water bodies are challenged by the temporal variability of air temperature and rainfall. Influences are different depending on flow controls, associated time lags and nutrient transformations that may occur along the pathways. In Europe weather patterns and trends are influenced by large-scale weather systems over the North Atlantic. One of the most prominent teleconnection patterns that affect the weather across all seasons is the North Atlantic Oscillation (NAO). In northwestern Europe a positive phase in the NAO index over the winter period is often associated with elevated air temperatures in summer and more frequent large rain events in winter than normal. The objective of this study was to investigate the catchment-scale influences and relationships of naturally altered hydro-meteorological processes on the diffuse N and P losses to waters, in order to distinguish natural climate effects from those caused by adaptive management (increased agricultural intensity, decreased nutrient use etc.). Here we present six years of monthly nitrate-N and total reactive P concentrations in stream water (aggregated from sub-hourly monitoring) in six, ca. 10 km2, Irish agricultural catchments with different hydrological flow controls and land use. The locations of the catchments make them susceptible to sudden and/or seasonal shifts in weather. Changes in long term air temperatures and rainfall were investigated and annual N and P concentrations were compared to the NAO. During the monitored period (2009-2015) there was a steady increase in wintertime NAO index, reaching positive values in recent years, resulting in higher air temperatures and more frequent large rain events in winter. In some settings annual N and/or P concentrations were positively correlated to the three-year moving average NAO index (R2 > 0.90). Catchments with free

  12. Grooved impactor and inertial trap for sampling inhalable particulate matter

    DOEpatents

    Loo, Billy W.

    1984-01-01

    An inertial trap and grooved impactor for providing a sharp cutoff for particles over 15 microns from entering an inhalable particulate sampler. The impactor head has a tapered surface and is provided with V-shaped grooves. The tapered surface functions for reducing particle blow-off or reentrainment while the grooves prevent particle bounce. Water droplets and any resuspended material over the 15 micron size are collected by the inertial trap and deposited in a reservoir associated with the impactor.

  13. The ISIS Mission Concept: An Impactor for Surface and Interior Science

    NASA Technical Reports Server (NTRS)

    Chesley, Steven R.; Elliot, John O.; Abell, Paul A.; Asphaug, Erik; Bhaskaran, Shyam; Lam, Try; Lauretta, Dante S.

    2013-01-01

    The Impactor for Surface and Interior Science (ISIS) mission concept is a kinetic asteroid impactor mission to the target of NASA's OSIRIS-REx (Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer) asteroid sample return mission. The ISIS mission concept calls for the ISIS spacecraft, an independent and autonomous smart impactor, to guide itself to a hyper-velocity impact with 1999 RQ36 while the OSIRIS-REx spacecraft observes the collision. Later the OSIRIS-REx spacecraft descends to reconnoiter the impact site and measure the momentum imparted to the asteroid through the impact before departing on its journey back to Earth. In this paper we discuss the planetary science, human exploration and impact mitigation drivers for mission, and we describe the current mission concept and flight system design.

  14. The ISIS Mission Concept: An Impactor for Surface and Interior Science

    NASA Technical Reports Server (NTRS)

    Chesley, Steven R.; Elliot, John O.; Abell, Paul A.; Asphaug, Erik; Bhaskaran, Shyam; Lam, Try; Lauretta, Dante S.

    2013-01-01

    The Impactor for Surface and Interior Science (ISIS) mission concept is a kinetic asteroid impactor mission to the target of NASA's OSIRIS-REx (Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer) asteroid sample return mission. The ISIS mission concept calls for the ISIS spacecraft, an independent and autonomous smart impactor, to guide itself to a hyper-velocity impact with 1999 RQ36 while the OSIRIS-REx spacecraft observes the collision. Later the OSIRIS-REx spacecraft descends to reconnoiter the impact site and measure the momentum imparted to the asteroid through the impact before departing on its journey back to Earth. In this paper we discuss the planetary science, human exploration and impact mitigation drivers for mission, and we describe the current mission concept and flight system design.

  15. Analytical electron microscopy of LDEF impactor residues

    SciTech Connect

    Bernhard, R.P.; Barrett, R.A.; Zolensky, M.E.

    1995-02-01

    The LDEF contained 57 individual experiment trays or tray portions specifically designed to characterize critical aspects of meteoroid and debris environment in low-Earth orbit (LEO). However, it was realized from the beginning that the most efficient use of the satellite would be to characterize impact features from the entire surface of the LDEF. With this in mind particular interest has focused on common materials facing in all 26 LDEF facing directions; among the most important of these materials has been the tray clamps. Therefore, in an effort to better understand the nature and flux of particulates in LEO, and their effects on spacecraft hardware, the authors are analyzing residues found in impact features on LDEF tray clamp surfaces. This paper summarizes all data from 79 clamps located on Bay A & B of the LDEF. The authors also describe current efforts to characterize impactor residues recovered from the impact craters, and they have found that a low, but significant, fraction of these residues have survived in a largely unmelted state. These residues can be characterized sufficiently to permit resolution of the impactor origin. The authors have concentrated on the residue from chondritic interplanetary dust particles (micrometeoroids), as these represent the harshest test of their analytical capabilities.

  16. Analytical electron microscopy of LDEF impactor residues

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Barrett, Ruth A.; Zolensky, Michael E.

    1995-01-01

    The LDEF contained 57 individual experiment trays or tray portions specifically designed to characterize critical aspects of meteoroid and debris environment in low-Earth orbit (LEO). However, it was realized from the beginning that the most efficient use of the satellite would be to characterize impact features from the entire surface of the LDEF. With this in mind particular interest has focused on common materials facing in all 26 LDEF facing directions; among the most important of these materials has been the tray clamps. Therefore, in an effort to better understand the nature and flux of particulates in LEO, and their effects on spacecraft hardware, we are analyzing residues found in impact features on LDEF tray clamp surfaces. This paper summarizes all data from 79 clamps located on Bay A & B of the LDEF. We also describe current efforts to characterize impactor residues recovered from the impact craters, and we have found that a low, but significant, fraction of these residues have survived in a largely unmelted state. These residues can be characterized sufficiently to permit resolution of the impactor origin. We have concentrated on the residue from chondritic interplanetary dust particles (micrometeoroids), as these represent the harshest test of our analytical capabilities.

  17. Design and pharmaceutical applications of a low-flow-rate single-nozzle impactor.

    PubMed

    Wang, Hui; Bhambri, Pallavi; Ivey, James; Vehring, Reinhard

    2017-09-20

    A new low-flow-rate (0.5L/min) single-nozzle impactor for the concentration of dilute aerosol particles with selected pharmaceutical applications is described in this paper. The impactor can be configured up to 11 stages with a wide range of cutoff diameters from 0.6μm to 21.1μm, enabling convenient sampling of inhalable drug particles from inhalation devices and drug production processes. Its unique single-nozzle design and removable impaction plate allow direct sample transfer for subsequent compositional, morphological, solid-state, and other analysis. Agreement between the measured size distribution of fluticasone propionate particles actuated from commercial pMDI Flixotide(®) 250 Evohaler(®) and reported data in the literature verified that the impactor stages have accurate cutoff diameters as designed. The multi-stage configuration of the impactor allows rapid separation of polydisperse aerosol particles into different size classes for further characterization. Overlapping of the Raman spectra of the double-component powders from the Seretide(®) 250 pMDI collected using two different methods demonstrated the applicability of the impactor for a representative sampling of multi-component aerosol particles for bulk composition analysis. A time-dependent and size-dependent stability study was conducted consuming only a single sample canister with 80mg of amorphous indomethacin particles suspended in HFA-134a. It was found that amorphous indomethacin particles converted to the γ crystalline polymorph upon storage at 45°C and that the crystallization rate is strongly size dependent. With its highly effective aerosol collection capability and accurate cutoff diameters for aerosol classification, the impactor will have various applications in the pharmaceutical industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. OLYMPEX Counterflow Spectrometer and Impactor Field Campaign Report

    SciTech Connect

    Poellot, Michael

    2016-07-01

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Aerial Facility (AAF) Counterflow Spectrometer and Impactor (CSI) probe was flown on the University of North Dakota Cessna Citation research aircraft during the Olympic Mountain Experiment (OLYMPEX). The field campaign took place from November 12 through December 19, 2015, over the Olympic Mountains and coastal waters of Washington State as part of a National Aeronautics and Space Administration (NASA) Global Precipitation Measurement (GPM) validation campaign. The CSI was added to the Citation instrument suite to support the NASA Aerosol-Cloud Ecosystem (ACE) satellite program and flights of the NASA Lockheed Earth Resources (ER-2) aircraft. ACE funded extra ER-2 flights to focus on clouds that are weakly precipitating, which are also of interest to the DOE Atmospheric System Research (ASR) program.

  19. A Study of the Ongoing Alignment of the NWEA RIT Scale with the Arizona Instrument to Measure Standards (AIMS)

    ERIC Educational Resources Information Center

    Cronin, John; Bowe, Branin

    2005-01-01

    Each spring, Arizona students participate in testing as part of the state's assessment program. Elementary and middle school students in grades 3 through 8 take the Arizona Instrument to Measure Standards--Dual Purpose Assessment (AIMS DPA) in reading, writing, and mathematics. These tests serve as an important measure of student achievement for…

  20. Computerized reduction of airborne foil impactor data

    NASA Technical Reports Server (NTRS)

    Peterson, Bret A.; Musil, Dennis J.; Smith, Paul L.

    1991-01-01

    A new technique for reducing data obtained from a foil impactor carried on the T-28 thunderstorm penetration aircraft is described. The technique employs a video-image processing system that was originally developed for satellite imagery and a computer-reduction program that was originally developed for determining cloud-size distributions to count and size particle impressions on the foil. This eliminates the tedious manual processing that has limited the usefulness of such devices, while at the same time improving objectivity. The technique has been applied to foil data acquired in thunderstorms in the southeastern United States during the Cooperative Huntsville Meteorological Experiment, where most of the particles were at least roughly spherical. Its usefulness for storms in which highly irregular or fragile ice particles predominate has yet to be established.

  1. Which Triple Aim related measures are being used to evaluate population management initiatives? An international comparative analysis.

    PubMed

    Hendrikx, Roy J P; Drewes, Hanneke W; Spreeuwenberg, Marieke; Ruwaard, Dirk; Struijs, Jeroen N; Baan, Caroline A

    2016-05-01

    Population management (PM) initiatives are introduced in order to create sustainable health care systems. These initiatives should focus on the continuum of health and well-being of a population by introducing interventions that integrate various services. To be successful they should pursue the Triple Aim, i.e. simultaneously improve population health and quality of care while reducing costs per capita. This study explores how PM initiatives measure the Triple Aim in practice. An exploratory search was combined with expert consultations to identify relevant PM initiatives. These were analyzed based on general characteristics, utilized measures and related selection criteria. In total 865 measures were used by 20 PM initiatives. All quality of care domains were included by at least 11 PM initiatives, while most domains of population health and costs were included by less than 7 PM initiatives. Although their goals showed substantial overlap, the measures applied showed few similarities between PM initiatives and were predominantly selected based on local priority areas and data availability. Most PM initiatives do not measure the full scope of the Triple Aim. Additionally, variety between measures limits comparability between PM initiatives. Consensus on the coverage of Triple Aim domains and a set of standardized measures could further both the inclusion of the various domains as well as the comparability between PM initiatives. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. The Trajectory of the Chelyabinsk Impactor

    NASA Astrophysics Data System (ADS)

    Chodas, Paul; Chesley, Steven R.

    2014-05-01

    On February 15, 2013, a small asteroid called 2012 DA14 was about to make a much anticipated extremely close flyby of the Earth, when an even smaller asteroid stole the show by impacting into the Earth's atmosphere near Chelyabinsk, Russia, releasing half a megaton of energy and creating a shock wave that reportedly injured more than a thousand people. The passage of a 40-meter asteroid within the ring of geosynchrounous satellites is rare, calculated to be a once-in-40-year event, and yet it was upstaged on the same day by an actual Earth impact of a previously unseen 20-meter asteroid, an event expected to occur only about once per century, on average. Infrasound-based estimates of the released energy from this impact lie in the range of from 450 to 700 kilotons, making the Chelyabinsk fireball the largest impact event since the Tunguska explosion over Siberia in 1908. We have analyzed the approach trajectory of the impactor using impact event data provide U.S. Government sensors. We compare our results with other more detailed analyses of the trajectory. All of the analyses indicate that the asteroid approached the Earth from within 20 degrees of the sunline. Clearly, this object could not have been detected on its final approach by any of the asteroid search programs, unlike the even smaller asteroid 2008 TC3, which was discovered as it approached the Earth from near the opposition point. It is also clear that the east-to-west trajectory of the Chelyabinsk impactor was very different from the south-to-north path of 2012 DA14, implying that the two asteroids were unrelated.

  3. The airborne mass spectrometer AIMS - Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

    NASA Astrophysics Data System (ADS)

    Jurkat, Tina; Kaufmann, Stefan; Voigt, Christiane; Schäuble, Dominik; Jeßberger, Philipp; Ziereis, Helmut

    2016-04-01

    Understanding the role of climate-sensitive trace gas variabilities in the upper troposphere and lower stratosphere region (UTLS) and their impact on its radiative budget requires accurate measurements. The composition of the UTLS is governed by transport and chemistry of stratospheric and tropospheric constituents, such as chlorine, nitrogen oxide and sulfur compounds. The Atmospheric chemical Ionization Mass Spectrometer AIMS has been developed to accurately measure a set of these constituents on aircraft by means of chemical ionization. Here we present a setup using SF5- reagent ions for the simultaneous measurement of trace gas concentrations of HCl, HNO3 and SO2 in the pptv to ppmv (10-12 to 10-6 mol mol-1) range with in-flight and online calibration called AIMS-TG (Atmospheric chemical Ionization Mass Spectrometer for measurements of trace gases). Part 1 of this paper (Kaufmann et al., 2016) reports on the UTLS water vapor measurements with the AIMS-H2O configuration. The instrument can be flexibly switched between two configurations depending on the scientific objective of the mission. For AIMS-TG, a custom-made gas discharge ion source has been developed for generation of reagent ions that selectively react with HCl, HNO3, SO2 and HONO. HNO3 and HCl are routinely calibrated in-flight using permeation devices; SO2 is continuously calibrated during flight adding an isotopically labeled 34SO2 standard. In addition, we report on trace gas measurements of HONO, which is sensitive to the reaction with SF5-. The detection limit for the various trace gases is in the low 10 pptv range at a 1 s time resolution with an overall uncertainty of the measurement of the order of 20 %. AIMS has been integrated and successfully operated on the DLR research aircraft Falcon and HALO (High Altitude LOng range research aircraft). As an example, measurements conducted during the TACTS/ESMVal (Transport and Composition of the LMS/UT and Earth System Model Validation) mission with

  4. The airborne mass spectrometer AIMS - Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

    NASA Astrophysics Data System (ADS)

    Jurkat, T.; Kaufmann, S.; Voigt, C.; Schäuble, D.; Jeßberger, P.; Ziereis, H.

    2015-12-01

    Understanding the role of climate-sensitive trace gas variabilities in the upper troposphere and lower stratosphere region (UTLS) and their impact on its radiative budget requires accurate measurements. The composition of the UTLS is governed by transport and chemistry of stratospheric and tropospheric constituents, such as chlorine, nitrogen oxide and sulphur components. The Airborne chemical Ionization Mass Spectrometer AIMS has been developed to accurately measure a set of these constituents on aircraft by means of chemical ionization. Here we present a setup using chemical ionization with SF5- reagent ions for the simultaneous measurement of trace gas concentrations in the pptv to ppmv (10-12 to 10-6 mol mol-1) range of HCl, HNO3 and SO2 with in-flight and online calibration called AIMS-TG. Part 1 of this paper (Kaufmann et al., 2015) reports on the UTLS water vapour measurements with the AIMS-H2O configuration. The instrument can be flexibly switched between two configurations depending on the scientific objective of the mission. For AIMS-TG, a custom-made gas discharge ion source has been developed generating a characteristic ionization scheme. HNO3 and HCl are routinely calibrated in-flight using permeation devices, SO2 is permanently calibrated during flight adding an isotopically labelled 34SO2 standard. In addition, we report on trace gas measurements of HONO which is sensitive to the reaction with SF5-. The detection limit for the various trace gases is in the low ten pptv range at a 1 s time resolution with an overall uncertainty of the measurement in the order of 20 %. AIMS has been integrated and successfully operated on the DLR research aircraft Falcon and HALO. Exemplarily, measurements conducted during the TACTS/ESMVal mission with HALO in 2012 are presented, focusing on a classification of tropospheric and stratospheric influences in the UTLS region. Comparison of AIMS measurements with other measurement techniques allow to draw a comprehensive

  5. Implementing an aim-based outcome measure in a psychoanalytic child psychotherapy service: insights, experiences and evidence.

    PubMed

    Emanuel, Ricky; Catty, Jocelyn; Anscombe, Elizabeth; Cantle, Alison; Muller, Helen

    2014-04-01

    In this paper, we describe the use of an aim-based outcome measure used in routine outcome monitoring of child and adolescent psychotherapy within a child and adolescent mental health service. We aim to explore the clinical feasibility and implications of the routine use of this measure. We argue that use of the measure provides a simple and useful way of clarifying the focus of the clinical work and reflecting its progress, while also having the potential to illuminate the clinical picture by contributing an additional source of clinical information from a collaborative process with the patient, parents or both. We argue that while there are some cases where use of the measure may be impossible, or even perverse, in general it enhances rather than detracts from clinical work.

  6. Development Study of a Two-Stage Continuous Flow Impactor.

    DTIC Science & Technology

    1980-03-01

    AD-AO83 3B7 TRW DEFENSE AND SPACE SYSTEMS GROUP REDONDO BEACH CA F/6 1/2 DEVELOPMENT STUDY OF A TWO-STAGE CONTINUOUS FLOW IMPACTOR.(U) MAR 80 N GAT...80009 r DEVELOPMENT STUDY OF A TWO-STAGE CONTINUOUS FLOW IMPACTOR Final Report , + by Nahum Gat March, 1980 TRW DEFENSE AND SPACE SYSTEMS GROUP...SYSTEMS LABORATORY CONTRACTOR REPORT ARCSL-CR-80009 DEVELOPMENT STUDY OF A TWO-STAGE CONTINUOUS FLOW IMPACTOR Final Report by Nahum Gat March, 1980 TRW

  7. The Asteroid Impact Mission (AIM): Studying the geophysics of small binaries, measuring asteroid deflection and studying impact physics

    NASA Astrophysics Data System (ADS)

    Kueppers, Michael; Michel, Patrick; AIM Team

    2016-10-01

    Binary asteroids and their formation mechanisms are of particular interest for understanding the evolution of the small bodies in the solar system. Also, hazards to Earth from impact of near-Earth asteroids and their mitigation have drawn considerable interest over the last decades.Those subjects are both addressed by ESA's Asteroid Impact mission, which is part of the Asteroid Impact & Deflection Assessment (AIDA) currently under study in collaboration between NASA and ESA. NASA's DART mission will impact a projectile into the minor component of the binary near-Earth asteroid (65803) Didymos in 2022. The basic idea is to demonstrate the effect of the impact on the orbital period of the secondary around the primary. ESA's AIM will monitor the Didymos system for several months around the DART impact time.AIM will be launched in aurumn 2020. It is foreseen to arrive at Didymos in April 2022. The mission takes advantage of a close approach of Didymos to Earth. The next opportunity would arise in 2040 only.AIM will stay near Didymos for approximately 6 months. Most of the time it will be placed on the illuminated side of the system, at distances of approximately 35 km and 10 km. AIM is expected to move away from Didymos for some time around the DART impact.The reference payload for AIM includes two visual imagers, a hyperspectral camera, a lidar, a thermal infrared imager, a monostatic high frequency radar, and a bistatic low frequency radar. In addition, AIM will deploy a small lander on the secondary asteroid, and two cubesats that will be used for additional, more risky investigations close to or on the surface of the asteroid.Major contributions from AIM are expected in the study of the geophysics of small asteroids (including for the first time, radar measurements of an interior structure), the formation of binary asteroids, the momentum enhancement factor from the DART impact (through measuring the mass and the change of orbit of the seondary), and impact physics

  8. Effect of impactor area on collision rate estimates

    SciTech Connect

    Canavan, G.H.

    1996-08-01

    Analytic and numercial estimates provide an assessment of the effect of impactor area on space debris collision rates, which is sufficiently small and insensitive to parameters of inerest that it could be neglected or corrected.

  9. Interaction of the conical impactor with barriers containing an explosive

    NASA Astrophysics Data System (ADS)

    Ishchenko, A. N.; Habibullin, M. V.; Afanas’eva, S. A.; Chupashev, A. V.; Zykova, A. I.

    2017-02-01

    This paper presents the actual problem of the dynamic interaction of a high-speed impactor with a screened explosive. The interaction mathematical model is based within the framework of continuum mechanics considering the mechanism of the shock-wave initiation of detonation in solid explosives. Testing of the method was conducted using experimental data in one dimension. Some problems of interaction of the conical impactor with the explosive protected one-layered and spaced metal barriers are numerically considered.

  10. Modeling the Historical Flux of Planetary Impactors

    NASA Astrophysics Data System (ADS)

    Nesvorný, David; Roig, Fernando; Bottke, William F.

    2017-03-01

    The impact cratering record of the Moon and the terrestrial planets provides important clues about the formation and evolution of the solar system. Especially intriguing is the epoch ≃3.8–3.9 Gyr ago (Ga), known as the Late Heavy Bombardment (LHB), when the youngest lunar basins such as Imbrium and Orientale formed. The LHB was suggested to originate from a slowly declining impactor flux or from a late dynamical instability. Here, we develop a model for the historical flux of large asteroid impacts and discuss how it depends on various parameters, including the time and nature of the planetary migration/instability. We find that the asteroid impact flux dropped by 1–2 orders of magnitude during the first 1 Gyr and remained relatively unchanged over the last 3 Gyr. The early impacts were produced by asteroids whose orbits became excited during the planetary migration/instability, and by those originating from the inner extension of the main belt. The profiles obtained for the early and late versions of the planetary instability initially differ, but end up being similar after ∼3 Ga. Thus, the time of the instability can only be determined by considering the cratering and other constraints during the first ≃1.5 Gyr of the solar system history. Our absolute calibration of the impact flux indicates that asteroids were probably not responsible for the LHB, independently of whether the instability happened early or late, because the calibrated flux is not large enough to explain Imbrium/Orientale and a significant proportion of large lunar craters.

  11. Water vapor measurements in- and outside cirrus with the novel water vapor mass spectrometer AIMS-H2O

    NASA Astrophysics Data System (ADS)

    Kaufmann, Stefan; Schlage, Romy; Voigt, Christiane; Jurkat, Tina; Krämer, Martina; Rolf, Christian; Zöger, Martin; Schäfler, Andreas; Dörnbrack, Andreas

    2015-04-01

    Water vapor plays a crucial role for the earth's climate both directly via its radiative properties and indirectly due to its ability to form clouds. However, accurate measurements of especially low water vapor concentrations prevalent in the upper troposphere and lower stratosphere are difficult and exhibit large discrepancies between different instruments and methods. In order to address this issue and to provide a comprehensive water vapor data set necessary to gather a complete picture of cloud formation processes, four state-of-the-art hygrometers including the novel water vapor mass spectrometer AIMS-H2O were deployed on the DLR research aircraft HALO during the ML-Cirrus campaign in March/April 2014 over Europe. Here, we present first water vapor measurements of AIMS-H2O on HALO. The instrument performance is validated by intercomparison with the fluorescence hygrometer FISH and the laser hygrometer SHARC, both also mounted in the aircraft. This intercomparison shows good agreement between the instruments from low stratospheric mixing ratios up to higher H2O concentrations at upper tropospheric conditions. Gathering data from over 24 flight hours, no significant offsets between the instruments were found (mean of relative deviation

  12. Behavior, preferences, and willingness to pay for measures aimed at preventing pollution by pharmaceuticals and personal care products in China.

    PubMed

    Wang, Xiaowen; Howley, Peter; Boxall, Alistair Ba; Rudd, Murray A

    2016-10-01

    The release of pharmaceuticals and personal care products (PPCPs) into the environment has been held up as a potential threat to ecosystem and human health. Using a custom-designed survey of residents living in Xiamen, China, this paper examines individuals' disposal practices, awareness of the environmental impact of PPCPs, and willingness to pay for measures aimed at reducing the likelihood of PPCPs being released into the environment. The vast majority of respondents report that they dispose of PPCPs through the thrash. The results of a contingent valuation experiment suggest a substantial willingness to pay (WTP) for policy measures aimed at reducing PPCP pollution. Income as well as subjective perceptions relating to overall financial health, expenditure on PPCPs, and overall concern with environmental issues emerged as significant predictors of respondents' WTP. Our results should be of interest to policymakers looking for ways to mitigate the introduction of PPCPs in the environment. Integr Environ Assess Manag 2016;12:793-800. © 2015 SETAC. © 2015 SETAC.

  13. Towards a proportionality assessment of risk reduction measures aimed at restricting the use of persistent and bioaccumulative substances.

    PubMed

    Oosterhuis, Frans; Brouwer, Roy; Janssen, Martien; Verhoeven, Julia; Luttikhuizen, Cees

    2017-05-26

    International chemicals legislation aims at adequately controlling persistent organic pollutants (POPs) and substances of very high concern (SVHCs), such as persistent, bioaccumulative, and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances, with a view to progressively substitute these substances with suitable less-hazardous alternatives. Using cost-effectiveness analysis (CEA) to assess the (dis)proportionality of measures to control such substances (collectively called "PBT" in the present paper) requires benchmarks. The present paper provides building blocks for possible benchmarks by looking at the cost-effectiveness estimates for regulatory measures that have been applied or considered for various PBT substances. These cost-effectiveness estimates vary widely, and the main factors possibly explaining this variation are discussed. The available cost estimates currently do not allow deriving a value for society's willingness to pay to reduce PBT presence, use, and emissions because decisions referring explicitly to these estimates are scarce. Roughly speaking, the available evidence suggests that measures costing less than €1000 per kilogram PBT use or emission reduction will usually not be rejected for reasons of disproportionate costs, whereas for measures with costs above €50 000 per kilogram PBT such a rejection is likely. More research is needed to strengthen the evidence base and further elaborate a systematic approach toward proportionality benchmarking. Integr Environ Assess Manag 2017;00:000-000. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2017 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc.

  14. Constraining the Flux of Impactors Postdating Heavy Bombardment Using U-Pb Ages of Impact Glasses

    NASA Technical Reports Server (NTRS)

    Nemchin, A. A.; Norman, M. L.; Ziegler, R. A.; Grange, M. L.

    2013-01-01

    Spherules of glass varying in size from a few micrometres to a few millimetres are common in the lunar regolith. While some of these glass beads are products of pyroclastic fire fountains others originate as impact melt ejected from the target that breaks into small droplets and solidifies as spherical particles while raining back to the lunar surface. These glasses preserve information about the chemical composition of the target and often contain sufficient amount of radioactive nuclides such as 40K to enable Ar-40-Ar-39 dating of individual beads. Studies measuring the age of glass beads have been used in attempts to establish variations in the flux of impactors hitting the Moon, particularly during the period that postdates the formation of major impact basins [1,2]. These studies proposed a possibility of spike in the impact flux about 800 Ma [2] and over the last 400 Ma [1]. More recently U-Th-Pb isotopic systems have been also utilized to determine the age of impact glasses from the Apollo 17 regolith [3]. Our aim is to extend the application of the U-Pb system in impact glasses to spherules isolated from Apollo 14 soil 14163 in an attempt to further investigate the applicability of this isotopic system to the chronology of impact glass beads and gain additional information on the impact flux in the inner Solar system.

  15. Shock melting of the canyon diablo impactor: constraints from nickel-59 contents and numerical modeling

    PubMed

    Schnabel; Pierazzo; Xue; Herzog; Masarik; Cresswell; di Tada ML; Liu; Fifield

    1999-07-02

    Two main types of material survive from the Canyon Diablo impactor, which produced Meteor Crater in Arizona: iron meteorites, which did not melt during the impact; and spheroids, which did. Ultrasensitive measurements using accelerator mass spectrometry show that the meteorites contain about seven times as much nickel-59 as the spheroids. Lower average nickel-59 contents in the spheroids indicate that they typically came from 0.5 to 1 meter deeper in the impactor than did the meteorites. Numerical modeling for an impact velocity of 20 kilometers per second shows that a shell 1.5 to 2 meters thick, corresponding to 16 percent of the projectile volume, remained solid on the rear surface; that most of the projectile melted; and that little, if any, vaporized.

  16. The effect of the impactor diameter and temperature on low velocity impact behavior of CFRP laminates

    NASA Astrophysics Data System (ADS)

    Evci, C.; Uyandıran, I.

    2017-02-01

    Impact damage is one of the major concerns that should be taken into account with the new aircraft and spacecraft structures which employ ever-growing use of composite materials. Considering the thermal loads encountered at different altitudes, both low and high temperatures can affect the properties and impact behavior of composite materials. This study aims to investigate the effect of temperature and impactor diameter on the impact behavior and damage development in balanced and symmetrical CFRP laminates which were manufactured by employing vacuum bagging process with autoclave cure. Instrumented drop-weight impact testing system is used to perform the low velocity impact tests in a range of temperatures ranged from 60 down to -50 °C. Impact tests for each temperature level were conducted using three different hemispherical impactor diameters varying from 10 to 20 mm. Energy profile method is employed to determine the impact threshold energies for damage evolution. The level of impact damage is determined from the dent depth on the impacted face and delamination damage detected using ultrasonic C-Scan technique. Test results reveal that the threshold of penetration energy, main failure force and delamination area increase with impactor diameter at all temperature levels. No clear influence of temperature on the critical force thresholds could be derived. However, penetration threshold energy decreased as the temperature was lowered. Drop in the penetration threshold was more obvious with quite low temperatures. Delamination damage area increased while the temperature decreased from +60 °C to -50 °C.

  17. Survival of the impactor during hypervelocity collisions - I. An analogue for low porosity targets

    NASA Astrophysics Data System (ADS)

    Avdellidou, C.; Price, M. C.; Delbo, M.; Ioannidis, P.; Cole, M. J.

    2016-03-01

    Recent observations of asteroidal surfaces indicate the presence of materials that do not match the bulk lithology of the body. A possible explanation for the presence of these exogenous materials is that they are products of interasteroid impacts in the Main Belt, and thus interest has increased in understanding the fate of the projectile during hypervelocity impacts. In order to gain insight into the fate of impactor, we have carried out a laboratory programme, covering the velocity range of 0.38-3.50 km s-1, devoted to measuring the survivability, fragmentation and final state of the impactor. Forsterite olivine and synthetic basalt projectiles were fired on to low porosity (<10 per cent) pure water-ice targets using the University of Kent's Light Gas Gun (LGG). We developed a novel method to identify impactor fragments which were found in ejecta and implanted into the target. We applied astronomical photometry techniques, using the SOURCE EXTRACTOR software, to automatically measure the dimensions of thousands of fragments. This procedure enabled us to estimate the implanted mass on the target body, which was found to be a few per cent of the initial mass of the impactor. We calculated an order of magnitude difference in the energy density of catastrophic disruption, Q*, between peridot and basalt projectiles. However, we found very similar behaviour of the size frequency distributions for the hypervelocity shots (>1 km s-1). After each shot, we examined the largest peridot fragments with Raman spectroscopy and no melt or alteration in the final state of the projectile was observed.

  18. Five-day Waves in Polar Stratosphere and Mesosphere Temperature and Mesospheric Ice Water Measured by SOFIE/AIM

    NASA Astrophysics Data System (ADS)

    Yue, J.; Liu, X.

    2015-12-01

    The temperature and column ice water content (IWC) of polar mesospheric clouds (PMCs) have been simultaneously measured by the Solar Occultation for Ice Experiment (SOFIE) onboard NASA's Aeronomy of Ice in the Mesosphere (AIM) satellite since April 2007. The 8-year (2007-2014) data of the temperature and IWC are used to extract the 5-day planetary waves (PWs) with zonal wavenumbers ranging from -1 to -3 (eastward propagating mode, E1-E3), 0 (stationary mode, W0), and 1 to 3 (westward propagating mode, W1-W3) in the polar stratosphere and mesosphere. The 5-day PWs in temperature are stronger in the polar winter stratosphere and mesosphere and exhibit substantial inter-hemispheric asymmetry. The date-height distributions of the 5-day waves coincide with those of the eastward jet in each hemisphere. This indicates that the 5-day PWs might be generated from barotropic/baroclinic instability in the polar stratosphere. The relative strengths of 5-day PWs decrease with increasing wavenumbers. The E1 (W1) 5-day PW is stronger than any other mode in the winter stratosphere and lower mesosphere (summer upper mesosphere). SOFIE temperature and IWC data are derived from simultaneous measurements in the same air column and thus provide a good opportunity to study the phase relationship between the 5-day PWs in temperature and IWC. Our analyses show that the phase shifts of W1 5-day PW in temperature relative to that in IWC have a mean of -2.0 h (0.3 h) with a standard deviation of 3.8 h (4.2 h) in the northern (southern) polar region. This indicates that the formation of the W1 5-day PW in PMCs is controlled mainly by the W1 5-day PW in temperature and influenced by other factors and is consistent with previous studies.

  19. The impactor flux in the Pluto-Charon system

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Stern, S. Alan

    1994-01-01

    Current impact rates of comets on Pluto and Charon are estimated. It is shown that the dominant sources of impactors are comets from the Kuiper belt and the inner Oort cloud, each of whose perihelion distribution extends across Pluto's orbit. In contrast, long-period comets from the outer Oort cloud are a negligible source of impactors. The total predicted number of craters is not sufficient to saturate the surface areas of either Pluto of Charon over the age of the Solar System. However, heavy cratering may have occurred early in the Solar System's history during clearing of planetesimals from the outer planets' zone.

  20. The impactor flux in the Pluto-Charon system

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Stern, S. Alan

    1994-01-01

    Current impact rates of comets on Pluto and Charon are estimated. It is shown that the dominant sources of impactors are comets from the Kuiper belt and the inner Oort cloud, each of whose perihelion distribution extends across Pluto's orbit. In contrast, long-period comets from the outer Oort cloud are a negligible source of impactors. The total predicted number of craters is not sufficient to saturate the surface areas of either Pluto of Charon over the age of the Solar System. However, heavy cratering may have occurred early in the Solar System's history during clearing of planetesimals from the outer planets' zone.

  1. ESA NEOCC effort to eliminate high Palermo Scale virtual impactors

    NASA Astrophysics Data System (ADS)

    Micheli, M.; Koschny, D.; Hainaut, O.; Bernardi, F.

    2014-07-01

    recovery observations of a few very faint high-PS objects, and the follow-up observations of recently discovered objects during the outgoing phase of their apparition, down to magnitude 25 or so. Most of these observations were obtained within an accepted DDT proposal of an ESA/ESO team, which gives us access on short notice to the observational capabilities of the 8.2 meter Very Large Telescope at Cerro Paranal, Chile. The instrument has been used to successfully detect targets fainter than V=25, and provide high-accuracy astrometry which in most cases has been sufficient to remove the impact solutions from the allowed future dynamics of the object. As a main focus of our activities at the ESA NEOCC we are also actively soliciting observations of NEOs by other worldwide observers which are known to have access to the most appropriate facilities for each target (in terms of telescope aperture, camera FoV and/or geographic location). We will also quickly summarize the results of some of these activities. In the second part of this contribution, we will present the result of a focused precovery effort by our team, which led to the identification, measurement and submission of previously unrecognized archival detections of possible impactors, most of which scored particularly high in the PS ranking, but would nevertheless have been unobservable for the imminent future. We will discuss a couple of interesting cases which could be entirely excluded as a risk thanks to the addition of faint detections we located in data from the Canada- France-Hawaii Telescope (CFHT), and an interesting case of a ''chain of precoveries'' where a first short-arc precovery allowed for the identification of additional observations obtained more than a decade earlier, which in turn lead to the elimination of the impact risk from that object. We will also discuss how a real time access to the data of current surveys like Pan-STARRS can allow almost immediate precovery observations of recently

  2. Experimental Characterization of Microfabricated VirtualImpactor Efficiency

    EPA Science Inventory

    The Air-Microfluidics Group is developing a microelectromechanical systems-based direct reading particulate matter (PM) mass sensor. The sensor consists of two main components: a microfabricated virtual impactor (VI) and a PM mass sensor. The VI leverages particle inertia to sepa...

  3. 16 CFR Figure 5 to Subpart A of... - Impactor

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Impactor 5 Figure 5 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR ARCHITECTURAL GLAZING MATERIALS The Standard Pt. 1201, Subpt. A, Fig. 5 Figure 5...

  4. 16 CFR Figure 5 to Subpart A of... - Impactor

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Impactor 5 Figure 5 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR ARCHITECTURAL GLAZING MATERIALS The Standard Pt. 1201, Subpt. A, Fig. 5 Figure 5...

  5. 16 CFR Figure 5 to Subpart A of... - Impactor

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Impactor 5 Figure 5 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR ARCHITECTURAL GLAZING MATERIALS The Standard Pt. 1201, Subpt. A, Fig. 5 Figure 5...

  6. 16 CFR Figure 5 to Subpart A of... - Impactor

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Impactor 5 Figure 5 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR ARCHITECTURAL GLAZING MATERIALS The Standard Pt. 1201, Subpt. A, Fig. 5 Figure 5...

  7. 16 CFR Figure 5 to Subpart A of... - Impactor

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Impactor 5 Figure 5 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR ARCHITECTURAL GLAZING MATERIALS The Standard Pt. 1201, Subpt. A, Fig. 5 Figure 5...

  8. Experimental Characterization of Microfabricated VirtualImpactor Efficiency

    EPA Science Inventory

    The Air-Microfluidics Group is developing a microelectromechanical systems-based direct reading particulate matter (PM) mass sensor. The sensor consists of two main components: a microfabricated virtual impactor (VI) and a PM mass sensor. The VI leverages particle inertia to sepa...

  9. Particle impactor assembly for size selective high volume air sampler

    DOEpatents

    Langer, Gerhard

    1988-08-16

    Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented impactor slots of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind the relatively larger particles according to the human thoracic separation system and passes through two elongate exhaust apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. The elongate exhaust apertures defining the impaction collection surface are spaced apart by a distance greater than the lengths of elongate impactor slots in the inlet element and are oriented to be normal thereto. By appropriate selection of dimensions and the number of impactor slots air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the impactor slots, in order to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks.

  10. Analysis of portable impactor performance for enumeration of viable bioaerosols.

    PubMed

    Yao, Maosheng; Mainelis, Gediminas

    2007-07-01

    Portable impactors are increasingly being used to estimate concentration of bioaerosols in residential and occupational environments; however, little data are available about their performance. This study investigated the overall performances of the SMA MicroPortable, BioCulture, Microflow, Microbiological Air Sampler (MAS-100), Millipore Air Tester, SAS Super 180, and RCS High Flow portable microbial samplers when collecting bacteria and fungi both indoors and outdoors. The performance of these samplers was compared with that of the BioStage impactor. The Button Aerosol Sampler equipped with gelatin filter was also included in the study. Results showed that the sampling environment can have a statistically significant effect on sampler performance, most likely due to the differences in airborne microorganism composition and/or their size distribution. Data analysis using analysis of variance showed that the relative performance of all samplers (except the RCS High Flow and MAS-100) was statistically different (lower) compared with the BioStage. The MAS-100 also had statistically higher performance compared with other portable samplers except the RCS High Flow. The Millipore Air Tester and the SMA had the lowest performances. The relative performance of the impactors was described using a multiple linear regression model (R(2) = 0.83); the effects of the samplers' cutoff sizes and jet-to-plate distances as predictor variables were statistically significant. The data presented in this study will help field professionals in selecting bioaerosol samplers. The developed empirical formula describing the overall performance of bioaerosol impactors can assist in sampler design.

  11. INVERTING CASCADE IMPACTOR DATA FOR SIZE-RESOLVED CHARACTERIZATION OF FINE PARTICULATE SOURCE EMISSIONS

    EPA Science Inventory

    Cascade impactors are particularly useful in determining the mass size distributions of particulate and individual chemical species. The impactor raw data must be inverted to reconstruct a continuous particle size distribution. An inversion method using a lognormal function for p...

  12. INVERTING CASCADE IMPACTOR DATA FOR SIZE-RESOLVED CHARACTERIZATION OF FINE PARTICULATE SOURCE EMISSIONS

    EPA Science Inventory

    Cascade impactors are particularly useful in determining the mass size distributions of particulate and individual chemical species. The impactor raw data must be inverted to reconstruct a continuous particle size distribution. An inversion method using a lognormal function for p...

  13. A small change in the design of a slit bioaerosol impactor significantly improves its collection characteristics.

    PubMed

    Grinshpun, Sergey A; Adhikari, Atin; Cho, Seung-Hyun; Kim, Ki-Youn; Lee, Taekhee; Reponen, Tiina

    2007-08-01

    While several methods are available for bioaerosol monitoring, impaction remains the most common one, particularly for collecting fungal spores. Earlier studies have shown that the collection efficiency of many conventional single-stage bioaerosol impactors falls below 50% for spores with an aerodynamic diameter between 1.7 and 2.5 microm because their cut-off size is 2.5 microm or greater. The cut-off size reduction is primarily done by substantially increasing the sampling flow rate or decreasing the impaction jet size, W, to a fraction of a millimetre, with both measures often impractical to implement. Some success has recently been reported on the utilization of an ultra-low jet-to-plate distance, S (S/W < 0.1), in circular impactors. This paper describes a laboratory evaluation and some field testing of two single-stage, single-nozzle, slit bioaerosol impactors, Allergenco-D and Air-O-Cell, which feature the same jet dimensions and flow rate but have some design configuration differences that were initially thought to be of low significance. The collection efficiency and the spore deposit characteristics were determined in the laboratory using real-time aerosol spectrometry and different microscopic enumeration methods as the test impactors were challenged with the non-biological polydisperse NaCl aerosol and the aerosolized fungal spores of Cladosporium cladosporioides, Aspergillus versicolor, and Penicillium melinii. The tests showed that a relatively small reduction in the jet-to-plate distance of a single-stage, single-nozzle impactor with a tapered inlet nozzle, combined with adding a straight section of sufficient length, can significantly decrease the cut-off size to the level that is sufficient to efficiently collect spores of all fungal species. Furthermore, it appears that the slit jet design may improve the application of partial spore counting methodologies with respect to those applied to circular deposits. Data from a demonstration field study

  14. Piloting the Oregon A.I.M. Project: Measuring Progress for Program Evaluation and Accountability. Final Report, 1997-98.

    ERIC Educational Resources Information Center

    Greater Pittsburgh Literacy Council, PA.

    A pilot project was conducted to implement the Oregon A.I.M. (Assessment, Instruction, Mastery), a tutor program accountability system developed in Oregon, in 15 volunteer-based programs in Pennsylvania and to make recommendations on the usefulness of this system as a means of collecting and aggregating data on student progress for these and…

  15. ASPECT spectral imaging satellite proposal to AIDA/AIM CubeSat payload

    NASA Astrophysics Data System (ADS)

    Kohout, Tomas; Näsilä, Antti; Tikka, Tuomas; Penttilä, Antti; Muinonen, Karri; Kestilä, Antti; Granvik, Mikael; Kallio, Esa

    2016-10-01

    The Asteroid Spectral Imaging Mission (ASPECT) is a part of the Asteroid Impact Mission (AIM) project, and aims to study the composition of the Didymos binary asteroid and the efects of space weathering and shock metamorphism in order to gain understanding of the formation and evolution of the Solar System. The joint ESA/NASA Asteroid Impact Detection Assessment (AIDA) mission to binary asteroid Didymos consists of the Asteroid Impact Mission (AIM) by ESA and the Double Asteroid Redirection Test (DART) by NASA. DART is targeted to impact the Didymos secondary component (Didymoon) while AIM monitors the impact efects. This will demonstrate the use of a kinetic impactor to detect potentially hazardous asteroids. Both spacecraft will be launched in 2020 and will arrive to Didymos in 2022. The AIM mission will also include two or three CubeSats, which will be released in the Didymos system. This arrangement opens up a possibility for secondary scientifc experiments. ASPECT is one of the proposed CubeSat payloads. ASPECT is a 3U CubeSat equipped with a VIS-NIR spectral imager and it will be used to measure the spectral characteristics of the impact site before and after the DART impact, as the impactor should bring fresh material to the surface. This gives a unique opportunity to study space weathering and shock efects on asteroids.

  16. Re-accretion Efficiencies in Small Impactor - Large Target Collisions

    NASA Astrophysics Data System (ADS)

    Jankowski, Tim; Wurm, G.; Jens, T.

    2013-10-01

    During the formation process of planets, small dust particles grow to km-sized planetesimals via collisions. While the collision partners are equally sized in early phases, fragmentation, catastrophic destruction and other recycling processes can lead to collisions between partners with various size ranges. The gas in protoplanetary disks exerts size- and mass-dependent drag forces on the dust particles and bodies present which is why the relative velocities between the small particles and larger bodies increase. A field of investigation are the small-impactor large-target collisions where (partial) erosion can occur and small ejected dust particles can be produced. These ejecta can couple to the gas quite rapidly and can then be recaptured by the target and stick to it in secondary collisions. We use a Monte-Carlo code to calculate re-accretion efficiencies under certain conditions i.e. in free molecular flow regime (stream lines end on target body; impactors are completely coupled to the gas). Using experimental data we developed a model for the amount, masses, directions, and velocities of the ejecta depending on the impactor mass and velocity and the position of impact. The amount of re-accreted ejecta as well as the total re-accreted mass can be determined by using the solution of the equation of motion for particles in gaseous environments. Both - the amount dependent efficiency as well as the mass dependent efficiency - are highly dependent on the seven free parameters (impact velocity, impactor size and density, target size and density, gas pressure and temperature) but generally benefit from high gas velocities and a large size difference between target and impactor. Our final intention is to provide an analytical expression for the re-accretion efficiencies in respect to the free parameters and to use this in different disk models for sweeping the free parameters dependent on the distance to the central star. One major advantage of our code is the

  17. Measurement and Analysis of Olfactory Responses with the Aim of Establishing an Objective Diagnostic Method for Central Olfactory Disorders

    NASA Astrophysics Data System (ADS)

    Uno, Tominori; Wang, Li-Qun; Miwakeichi, Fumikazu; Tonoike, Mitsuo; Kaneda, Teruo

    In order to establish a new diagnostic method for central olfactory disorders and to identify objective indicators, we measured and analyzed brain activities in the parahippocampal gyrus and uncus, region of responsibility for central olfactory disorders. The relationship between olfactory stimulation and brain response at region of responsibility can be examined in terms of fitted responses (FR). FR in these regions may be individual indicators of changes in brain olfactory responses. In the present study, in order to non-invasively and objectively measure olfactory responses, an odor oddball task was conducted on four healthy volunteers using functional magnetic resonance imaging (fMRI) and a odorant stimulator with blast-method. The results showed favorable FR and activation in the parahippocampal gyrus or uncus in all subjects. In some subjects, both the parahippocampal gyrus and uncus were activated. Furthermore, activation was also confirmed in the cingulate gyrus, middle frontal gyrus, precentral gyrus, postcentral gyrus, superior temporal gyrus and insula. The hippocampus and uncus are known to be involved in the olfactory disorders associated with early-stage Alzheimer's disease and other olfactory disorders. In the future, it will be necessary to further develop the present measurement and analysis method to clarify the relationship between central olfactory disorders and brain activities and establish objective indicators that are useful for diagnosis.

  18. Fabrication and application of high impedance graded density impactors in light gas gun experiments

    SciTech Connect

    Yep, Steven J.; Belof, Jonathan L.; Orlikowski, Daniel A.; Nguyen, Jeffrey H.

    2013-10-01

    Recent advances in Graded Density Impactor fabrication technique have increased the maximum achievable pressure in gas gun quasi-isentropic experiments to 5 Mbars. In this report, we outline the latest methodologies and applications of Graded Density Impactors in experiments at extreme conditions. These new Graded Density Impactors are essentially metallic discs made of nearly one hundred layers of precisely mixed Mg, Cu, and W. The density gradients in these impactors are specifically designed to generate the desired thermodynamic path required for each experiment. We carried out a number of experiments at various pressures using these Graded Density Impactors. These experimental results and their simulations will be presented here.

  19. LEO-to-ground polarization measurements aiming for space QKD using Small Optical TrAnsponder (SOTA).

    PubMed

    Carrasco-Casado, Alberto; Kunimori, Hiroo; Takenaka, Hideki; Kubo-Oka, Toshihiro; Akioka, Maki; Fuse, Tetsuharu; Koyama, Yoshisada; Kolev, Dimitar; Munemasa, Yasushi; Toyoshima, Morio

    2016-05-30

    Quantum communication, and more specifically Quantum Key Distribution (QKD), enables the transmission of information in a theoretically secure way, guaranteed by the laws of quantum physics. Although fiber-based QKD has been readily available since several years ago, a global quantum communication network will require the development of space links, which remains to be demonstrated. NICT launched a LEO satellite in 2014 carrying a lasercom terminal (SOTA), designed for in-orbit technological demonstrations. In this paper, we present the results of the campaign to measure the polarization characteristics of the SOTA laser sources after propagating from LEO to ground. The most-widely used property for encoding information in free-space QKD is the polarization, and especially the linear polarization. Therefore, studying its behavior in a realistic link is a fundamental step for proving the feasibility of space quantum communications. The results of the polarization preservation of two highly-polarized lasers are presented here, including the first-time measurement of a linearly-polarized source at λ = 976 nm and a circularly-polarized source at λ = 1549 nm from space using a realistic QKD-like receiver, installed in the Optical Ground Station at the NICT Headquarters, in Tokyo, Japan.

  20. Impactor control of central peak and peak-ring formation

    NASA Astrophysics Data System (ADS)

    Schultz, Peter H.; Gault, D. E.

    1993-03-01

    The relation between the depth and diameter of excavation for impacts typically is assumed to be proportional. Such an assumption is consistent with the constant aspect ratio (diameter:depth) observed for simple craters found in a wide range of planetary settings and crater-scaling laws derived from laboratory experiments. Although complex craters exhibit evidence for floor uplift and rim collapse of a transient profile, they are typically thought to resemble initially smaller, simple craters. At large scales, however, early-time processes consume a greater fraction of crater growth and the assumption of late-time equivalence of energy release as a point source becomes inappropriate. The authors propose instead that crater diameter, depth, and impactor penetration represent separable dependent variables that underscore the fundamental difference between impact and point-source explosion excavation processes. An important consequence of this perspective is that central pits, peaks, and rings may represent contrasting target responses to impactor penetration and could provide an important indicator of impactor dimensions.

  1. Preventive measures aimed at minimizing the risk of African swine fever virus spread in pig farming systems.

    PubMed

    Bellini, Silvia; Rutili, Domenico; Guberti, Vittorio

    2016-11-29

    African swine fever (ASF) is one of the most severe diseases of pigs; it has a drastic impact on the pig industry, causing serious socio-economic consequences to pig farmers and pork producers. In Europe, there are currently two main clusters of infection; one in Sardinia caused by strains of African swine fever virus (ASFV) belonging to genotype I and another in Eastern Europe caused by strains of ASFV belonging to genotype II. The latter is inducing an acute form of ASF and it represents a serious threat to the pig sector. ASF is a disease for which there is no effective vaccine; therefore, prevention has a pivotal role in the control strategy of the disease. This review describes the main preventive measures to adopt to mitigate the risk of ASF spread in pig farming systems.

  2. Prediction of imminent impactors: Announcement policy and need of follow-up observations

    NASA Astrophysics Data System (ADS)

    Bernardi, F.; Milani, A.; Spoto, F.; Tommei, G.

    2014-07-01

    The detection of imminent impactors poses some delicate questions regarding the announcement policy. In fact, having very few observations, the impact probability computation is a difficult task and it strongly depends on: - the intrinsic astrometric errors of the observations; - the assumed population model - the minimum size of impactors We present a new web based automatic tool which computes the risk assesment within few minutes from the posting of new observations of a recently detected object on the MPC-NEOCP list. The aim of this imminent impactors tool is to raise awareness of the professional and amateur astronomical community on the possibility of the existence of an impact, within few days or hours, of objects posted on the NEOCP list of the MPC. Therefore astronomers can be triggered in a short time to follow these kind of objects, in order to improve the knowledge of the impact occurrence and location. It is important to stress that the minimal information from the observations provides a considerable number of spurious cases. This is a main difference with the classical impact monitoring activities of CLOMON2-NEODyS, because the need of a rapid response of the observers requires an automatic procedure while for CLOMON2 an operator decides if the output of the computation is reliable to be posted. In this presentation we will discuss the methods to filter the reliable cases and the announcement policy that we want to implement in the NEODyS system, taking into account the need of a feedback from the community of scientists.

  3. Five-day waves in polar stratosphere and mesosphere temperature and mesospheric ice water measured by SOFIE/AIM

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Yue, Jia; Xu, Jiyao; Yuan, Wei; Russell, James M., III; Hervig, Mark E.

    2015-05-01

    The temperature and column ice water content (IWC) of polar mesospheric clouds (PMCs) have been simultaneously measured by the Solar Occultation for Ice Experiment (SOFIE) on board NASA's Aeronomy of Ice in the Mesosphere satellite since April 2007. The 8 year (2007-2014) data of the temperature and IWC are used to extract the 5 day planetary waves (PWs) with zonal wave numbers ranging from -1 to -3 (eastward propagating mode, E1-E3), 0 (stationary mode, W0), and 1 to 3 (westward propagating mode, W1-W3) in the polar stratosphere and mesosphere. The 5 day PWs in temperature are stronger in the polar winter stratosphere and mesosphere and exhibit substantial interhemispheric asymmetry. The date-height distributions of the 5 day waves coincide with those of the eastward jet in each hemisphere. This indicates that the 5 day PWs might be generated from barotropic/baroclinic instability in the polar stratosphere. The relative strengths of 5 day PWs decrease with increasing wave numbers. The E1 (W1) 5 day PW is stronger than any other mode in the winter stratosphere and lower mesosphere (summer upper mesosphere). SOFIE temperature and IWC data are derived from simultaneous measurements in the same air column and thus provide a good opportunity to study the phase relationship between the 5 day PWs in temperature and IWC. Our analyses show that the phase shifts of W1 5 day PW in temperature relative to that in IWC have a mean of -2.0 h (0.3 h) with a standard deviation of 3.8 h (4.2 h) in the northern (southern) polar region. This indicates that the formation of the W1 5 day PW in PMCs is controlled mainly by the W1 5 day PW in temperature and influenced by other factors and is consistent with previous studies.

  4. AIM Spacecraft Instruments

    NASA Image and Video Library

    AIM will make simultaneous measurements of the main ingredients needed to form these clouds and will unravel the role of natural factors, such as the solar cycle and meteorology, from the possible ...

  5. Impact Crater Size-Frequency Distributions (SFD) on Saturnian Satellites in Comparison with Possible Impactor Populations

    NASA Astrophysics Data System (ADS)

    Schmedemann, Nico; Neukum, Gerhard; Denk, Tilmann; Wagner, Roland; Hartmann, Oliver

    2010-05-01

    One of the major goals of the Cassini imaging experiment (ISS) is the examination of the geologic history of the saturnian satellites [1]. The understanding of the impact crater SFD of the saturnian satellites allows insights of the bombardment history of the early outer solar system. Thus it provides not only information of the geologic development of the target bodies but is also key for the determination of the impactor sources as well. The impact-crater SFD of the mid-sized saturnian satellites has been measured as described by [2]. There are high similarities in the shapes of the asteroid-body SFD around the 3:1 mean motion resonance (MMR) gap with Jupiter and the measured impact crater SFD on the saturnian satellites. This allows for an estimation of the impact-crater scaling. The observationally derived scale factor between the impactor diameter and the respective impact-crater diameter is about three to four in case of Iapetus's larger craters and doesn't change much on other mid-sized saturnian satellites like Rhea or Dione. Hence, by shifting the impact-crater SFD curve of Iapetus to smaller sizes by the amount of the scaling factor of three to four, we get the impactor-body SFD for Iapetus. Thus we can compare the impactor-body SFD of Iapetus with body SFD of possible populations of impacting bodies like Kuiper- Belt objects (KBO), asteroids or the irregular satellites of Saturn. As stated by [3], intensive analyses of the impact crater diameter SFDs of the surfaces of the inner solar system bodies have revealed a characteristic W-shaped curve in the R-plot. The measurements of the crater-diameter SFD on the saturnian satellites Mimas, Tethys, Dione, Rhea, and Iapetus also show high similarities to those W-shaped curves of the inner solar system bodies. The derived body SFD of the asteroid belt (method of abs. magnitude to size conversion by [4]) around the 3:1 MMR with Jupiter gives a very good match to the lunar SFD and thus to the jovian and saturnian

  6. Adherence to Biobehavioral Recommendations in Pediatric Migraine as Measured by Electronic Monitoring: The Adherence in Migraine (AIM) Study

    PubMed Central

    Van Diest, Ashley M. Kroon; Ramsey, Rachelle; Aylward, Brandon; Kroner, John W.; Sullivan, Stephanie M.; Nause, Katie; Allen, Janelle R.; Chamberlin, Leigh A.; Slater, Shalonda; Hommel, Kevin; LeCates, Susan L.; Kabbouche, Marielle A.; O’Brien, Hope L.; Kacperski, Joanne; Hershey, Andrew D.; Powers, Scott W.

    2016-01-01

    Objective The purpose of this investigation was to examine treatment adherence to medication and lifestyle recommendations among pediatric migraine patients using electronic monitoring systems. Background Nonadherence to medical treatment is a significant public health concern, and can result in poorer treatment outcomes, decreased cost-effectiveness of medical care, and increased morbidity. No studies have systematically examined adherence to medication and lifestyle recommendations in adolescents with migraine outside of a clinical trial. Methods Participants included 56 adolescents ages 11 – 17 who were presenting for clinical care. All were diagnosed with migraine with or without aura or chronic migraine and had at least 4 headache days per month. Medication adherence was objectively measured using electronic monitoring systems (Medication Event Monitoring Systems technology) and daily, prospective self-report via personal electronic devices. Adherence to lifestyle recommendations of regular exercise, eating, and fluid intake were also assessed using daily self-report on personal electronic devices. Results Electronic monitoring indicates that adolescents adhere to their medication 75% of the time, which was significantly higher than self-reported rates of medication adherence (64%). Use of electronic monitoring of medication detected rates of adherence that were significantly higher for participants taking once daily medication (85%) versus participants taking twice daily medication (59%). Average reported adherence to lifestyle recommendations of consistent non-caffeinated fluid intake (M = 5 cups per day) was below recommended levels of a minimum of 8 cups per day. Participants on average also reported skipping 1 meal per week despite recommendations of consistently eating three meals per day. Conclusions Results suggest that intervention focused on adherence to preventive treatments (such as medication) and lifestyle recommendations may provide more

  7. Multi-shock assembly for protecting a spacecraft surface from hypervelocity impactors

    NASA Technical Reports Server (NTRS)

    Dvorak, Bruce D. (Inventor)

    2001-01-01

    A hypervelocity impact shield assembly for protecting a spacecraft surface from hypervelocity impactors. The shield assembly includes at least one sacrificial impactor disrupting/shocking layer of hypervelocity impactor disrupting/shocking material. A primary spacing element, including space-rated open cell foam material, is positioned between the at least one sacrificial impactor disrupting/shocking layer and a spacecraft surface. A cover member is arranged and disposed relative to the sacrificial impactor disrupting/shocking layer and the primary spacing element to maintain the integrity of the hypervelocity impact shield assembly. In the event of exposure to a hypervelocity impactor, the sacrificial impactor disrupting/shocking layer is perforated while shocking the impactor breaking it into fragments, and/or melting it, and/or vaporizing it, thus providing a dispersion in the form of an expanding debris cloud/plume which spreads the impact energy of the impactor over a volume formed by the primary spacing element between the sacrificial impactor disrupting/shocking layer and the spacecraft surface. This significantly reduces impact lethality at the spacecraft surface. The space-rated open cell foam material provides an extremely lightweight, low-cost, efficient means of spacing and supporting the at least one sacrificial impactor disrupting/shocking layer before, during, and after launch. In a preferred embodiment, the invention is in the form of a multi-shock assembly including a plurality of sacrificial impactor disrupting/shocking layers. In such instance, the hypervelocity impact shield assembly includes a plurality of secondary spacing elements. Each secondary spacing element is positioned adjacent an associated sacrificial impactor disrupting/shocking layer to form a multi-shock subassembly. Thus, a plurality of multi-shock subassemblies are provided which include alternating layers of sacrificial impactor disrupting/shocking layers and secondary spacing

  8. Post-mitigation impact risk assessment for NASA's DART kinetic impactor mission

    NASA Astrophysics Data System (ADS)

    Eggl, Siegfried; Hestroffer, Daniel; DART, AIM

    2016-10-01

    Field-testing kinetic impactors to deflect potentially hazardous asteroids (PHAs) is essential to better understand the challenges of future asteroid impact threat mitigation. The Asteroid Impact and Deflection Assessment mission (AIDA, Cheng et al. 2016), a collaborative effort between NASA and ESA, offers a timely opportunity to validate kinetic impact deflection strategies. Although the main goal of NASA's kinetic impactor (DART) is to change the circumprimary orbit of (65803) Didymos' moonlet, the imparted momentum will also slightly change the heliocentric orbit of the whole binary asteroid system. Given the high degree of non-linearity of the near-Earth dynamical environment, however, even a small change in initial conditions can affect long term predictions of the encounter distances between Didymos and the Earth. Belonging to the dynamical class of PHAs, (65803) Didymos has several encounters with the Earth over the upcoming decades, some of which are closer than 20 lunar distances. In order to confirm that no planetary safety issues arise as a consequence of DART, we conducted a post-mitigation impact risk assessment (PMIRA, Eggl et al. 2015) for the currently foreseen DART impact trajectories. In this contribution we present the latest PMIRA results and discuss the role of ESA's AIM spacecraft in reducing uncertainties arising in the deflection process.

  9. Fabrication and Characterization of Graded Impedance Gas Gun Impactors from Tape Cast Metal Powders

    SciTech Connect

    Martin, L P; Nguyen, J H

    2005-11-21

    Fabrication of compositionally graded structures for use as light-gas gun impactors has been demonstrated using a tape casting technique. Mixtures of metal powders in the Mg-Cu system were cast into a series of tapes with uniform compositions ranging from 100% Mg to 100% Cu. The individual compositions were fabricated into monolithic pellets for characterization by laminating multiple layers together, thermally removing the organics, and hot-pressing to near-full density. The pellets were characterized by optical and scanning electron microscopy, X-ray diffraction, and measurement of density and sound wave velocity. The density and acoustic impedance were observed to vary monotonically (and nearly linearly) with composition. Graded structures were fabricated by stacking layers of different compositions in a sequence calculated to yield a desired acoustic impedance profile. The measured physical properties of the graded structures compare favorably with those predicted from the monolithic-pellet characteristics. Fabrication of graded impactors by this technique is of significant interest for providing improved control of the pressure profile in gas gun experiments.

  10. Orbital and Physical Characteristics of Meter-sized Earth Impactors

    NASA Astrophysics Data System (ADS)

    Brown, Peter G.; Wiegert, Paul; Clark, David; Tagliaferri, Edward

    2015-11-01

    We have analysed the orbits and ablation characteristics in the atmosphere of more than 60 earth-impacting meteoroids of one meter in diameter or larger. Using heights at peak luminosity as a proxy for strength, we find that there is roughly an order of magnitude spread in the apparent strength of the population of meter-sized impactors at the Earth. The orbits and physical strength of these objects are consistent with the majority being asteroidal bodies originating from the inner main asteroid belt. We find ~10-15% of our objects have a probable cometary (Jupiter-Family comet and/or Halley-type comet) origin based on orbital characteristics alone. Only half this number, however, show evidence for the expected weaker than average structure compared to asteroidal bodies. Almost all impactors show peak brightness between 20-40 km altitude. Several events have exceptionally high (relative to the remainder of the population) heights of peak brightness. These are physically most consistent with high microporosity objects, though all were on asteroidal-type orbits. We also find three events, including the Oct 8, 2009 airburst near Sulawesi, Indonesia, which display comparatively low heights of peak brightness, consistent with strong monolithic stones or iron meteoroids. Based on orbital similarity, we find a probable connection among several NEOs in our population with the Taurid meteoroid complex. No other major meteoroid streams show linkages with the pre-atmospheric orbits of our meter-class impactors. Our events cover almost four orders of magnitude in mass, but no trend in height of peak brightness is evident, suggesting no strong trend in strength with size for small NEOs, a finding consistent with the results of Popova et al (2011).

  11. Trajectory Design for a Single-String Impactor Concept

    NASA Technical Reports Server (NTRS)

    Dono Perez, Andres; Burton, Roland; Stupl, Jan; Mauro, David

    2017-01-01

    This paper introduces a trajectory design for a secondary spacecraft concept to augment science return in interplanetary missions. The concept consist of a single-string probe with a kinetic impactor on board that generates an artificial plume to perform in-situ sampling. The trajectory design was applied to a particular case study that samples ejecta particles from the Jovian moon Europa. Results were validated using statistical analysis. Details regarding the navigation, targeting and disposal challenges related to this concept are presented herein.

  12. Craters on Pluto and Charon: Characteristics and Impactor Population

    NASA Astrophysics Data System (ADS)

    Singer, Kelsi N.; Schenk, Paul M.; Robbins, Stuart J.; Bray, Veronica J.; McKinnon, William B.; Moore, Jeffrey M.; Spencer, John R.; Stern, S. A.; Grundy, W. M.; Howett, Carly J. A.; Dalle Ore, Cristina M.; Beyer, Ross; Parker, Alex H.; Porter, Simon B.; Zangari, Amanda M.; Young, Leslie A.; Olkin, Cathy B.; Ennico, Kimberly

    2015-11-01

    Although both Pluto and Charon have a surprising number of young-looking surfaces, there are still plenty of craters for impact-phenomenon enthusiasts. We will present size, morphology, ejecta, and albedo pattern statistics, in addition to correlations with color/composition where possible. We use images and topography from the Long Range Reconnaissance Imager (LORRI; Cheng et al., 2008, SSR 140, 189-215) and data from the Ralph (Reuter et al., 2008, SSR 140, 129-154) color/composition instruments.Impactor sizes will be estimated from relevant scaling laws for cold water ice (see details in Singer and Stern, 2015, ApJL 808, L50). For Pluto, an image strip at 125 m px-1 includes some cratered terrains, and much of the encounter hemisphere (the anti-Charon hemisphere) will be covered at ~400 m px-1. The ~smallest craters observable at these pixel scales (using a 5 pixel limit) would be ~0.63 km, and ~2 km in diameter, respectively, with impactor diameters estimated at ~50 m, and ~200 m. However, it is likely that degradation processes may obscure small craters, thus this lower observation limit will depend on terrain type. Additionally, lighting and observation geometries vary across the disk, which may make crater detection difficult in some areas. All of the illuminated portions of Pluto (during its 6.4 day rotation period) were imaged at ~20 km px-1 or better during the encounter. The highest resolution images of Pluto (at ~80 m px-1) occur in a narrow strip and are not scheduled for downlink before the DPS.The highest resolution Charon coverage (a strip at ~160 m px-1), a broader swath at 400 m px-1, and the entire encounter hemisphere (the sub-Pluto hemisphere) at ~890 m px-1 may yield craters as small as 0.8, 2, and 4.5 km in diameter, respectively. The inferred impactor sizes for these craters would be ~50 m, 160 m, and 440 m.Although the dataset is limited, we will discuss what constraints can be put on the impactor population. This work was supported by the

  13. The origin of planetary impactors in the inner solar system.

    PubMed

    Strom, Robert G; Malhotra, Renu; Ito, Takashi; Yoshida, Fumi; Kring, David A

    2005-09-16

    Insights into the history of the inner solar system can be derived from the impact cratering record of the Moon, Mars, Venus, and Mercury and from the size distributions of asteroid populations. Old craters from a unique period of heavy bombardment that ended approximately 3.8 billion years ago were made by asteroids that were dynamically ejected from the main asteroid belt, possibly due to the orbital migration of the giant planets. The impactors of the past approximately 3.8 billion years have a size distribution quite different from that of the main belt asteroids but very similar to that of near-Earth asteroids.

  14. Formation of the moon in a giant impact - Composition of the impactor

    NASA Technical Reports Server (NTRS)

    Mcfarlane, E. A.

    1989-01-01

    The compositional plausiblity of an impactor that may have triggered the formation of the moon according to the giant impact hypothesis is examined. The impactor compositions are calculated based on lunar bulk and terrestrial mantle plus crust compositional estimates. The composition of the outer portion of the impactor is determined in increments of 0.1 from alpha = 0 to alpha = 0.9, where alpha is the fraction of the moon derived from the earth. A diffentiated impactor is simulated by systematically adding a 10, 20, 30, and 40 percent by mass Fe core. Calculated bulk impactor compositions are evaluated for their plausibility by comparison with known meteorite types. Fits are best when a core is assumed to exist within the impactor. No more than about 80 percent of the moon's material can be derived from the earth. Best matches with meteorites tend to occur for values of alpha less than 0.5.

  15. Next generation pharmaceutical impactor: a new impactor for pharmaceutical inhaler testing. Part III. extension of archival calibration to 15 L/min.

    PubMed

    Marple, Virgil A; Olson, Bernard A; Santhanakrishnan, Kumaragovindhan; Roberts, Daryl L; Mitchell, Jolyon P; Hudson-Curtis, Buffy L

    2004-01-01

    An extension of the archival calibration of the recently developed 30-100-L/min seven-stage impactor, the Next Generation Pharmaceutical Impactor (NGI), has been undertaken at 15 L/min. The NGI stage cut sizes are 0.98-14.1 microm aerodynamic diameter at this flow rate. This 15-L/min calibration was motivated by the desire to sample the entire aerosol produced by a nebulizer when tested in accordance with a new international standard developed by the Comite Européen de Normalisation (CEN), as well as the need to test various types of inhalers at flow rates lower than 30 L/min for pediatric applications. Measurements were undertaken with monodisperse oleic acid droplets in the range of 0.7-22 microm aerodynamic diameter following a procedure established in the original 30-100-L/min calibration study. The NGI was found to be effective for particle size separation at 15 L/min. Users should decide the most applicable configuration that meets their needs, based on the following recommendations: (1) the pre-separator should not normally be used, as its performance is significantly degraded by the influence of gravity, resulting in interference with stage 1; and (2) a filter should be inserted below the micro-orifice collector (MOC), as the size corresponding to 80% collection efficiency of the MOC becomes excessively large with decreasing flow rate, so that this component becomes ineffective as a means of collecting fine particles that penetrate beyond stage 7.

  16. Nonideal collection characteristics of a cascade impactor with various collection substrates

    SciTech Connect

    Barr, E.B.; Newton, G.J.; Yeh, H.C.

    1982-09-01

    A series of collection substrates was used to evaluate the dependence of collection efficiency on substrate type on one stage of a seven-stage cascade impactor. Data obtained were used to determine which substrates yielded the best collection characteristics for cascade impactors. Stainless steel, silver membrane filters, and cellulose acetate membrane filters as cascade impactor collection substrates showed stage collection characteristics that closely fit theoretical predictions. Fiber-type substrates showed the most deviation from the theoretical efficiency curve.

  17. Quantitative sampling and analysis of trace elements in atmospheric aerosols: impactor characterization and Synchrotron-XRF mass calibration

    NASA Astrophysics Data System (ADS)

    Richard, A.; Bukowiecki, N.; Lienemann, P.; Furger, M.; Fierz, M.; Minguillón, M. C.; Weideli, B.; Figi, R.; Flechsig, U.; Appel, K.; Prévôt, A. S. H.; Baltensperger, U.

    2010-10-01

    Identification of trace elements in ambient air can add substantial information to pollution source apportionment studies, although they do not contribute significantly to emissions in terms of mass. A method for quantitative size and time-resolved trace element evaluation in ambient aerosols with a rotating drum impactor and synchrotron radiation based X-ray fluorescence is presented. The impactor collection efficiency curves and size segregation characteristics were investigated in an experiment with oil and salt particles. Cutoff diameters were determined through the ratio of size distributions measured with two particle sizers. Furthermore, an external calibration technique to empirically link fluorescence intensities to ambient concentrations was developed. Solutions of elemental standards were applied with an ink-jet printer on thin films and area concentrations were subsequently evaluated with external wet chemical methods. These customized and reusable reference standards enable quantification of different data sets analyzed under varying experimental conditions.

  18. Quantitative sampling and analysis of trace elements in ambient air: impactor characterization and Synchrotron-XRF mass calibration

    NASA Astrophysics Data System (ADS)

    Richard, A.; Bukowiecki, N.; Lienemann, P.; Furger, M.; Weideli, B.; Fierz, M.; Minguillón, M. C.; Figi, R.; Flechsig, U.; Appel, K.; Prévôt, A. S. H.; Baltensperger, U.

    2010-06-01

    Identification of trace elements in ambient air can add substantial information to pollution source apportionment studies, although they do not contribute significantly to emissions in terms of mass. A method for quantitative size and time-resolved trace element evaluation in ambient aerosols with a rotating drum impactor and synchrotron radiation based X-ray fluorescence is presented. The impactor collection efficiency curves and size segregation characteristics were investigated in an experiment with oil and salt particles. Cutoff diameters were determined through the ratio of size distributions measured with two particles sizers. Furthermore, an external calibration technique to empirically link fluorescence intensities to ambient concentrations was developed. Solutions of elemental standards were applied with an ink-jet printer on thin films and area concentrations were subsequently evaluated with external wet chemical methods. These customized and reusable reference standards enable quantification of different data sets analyzed under varying experimental conditions.

  19. Conversion Equation between the Drop Height in the New York University Impactor and the Impact Force in the Infinite Horizon Impactor in the Contusion Spinal Cord Injury Model.

    PubMed

    Khuyagbaatar, Batbayar; Kim, Kyungsoo; Kim, Yoon Hyuk

    2015-12-15

    There are several widely used devices for controlled contusion of the spinal cord, including the Ohio State University device, the University of British Columbia multi-mechanisms injury device, the New York University (NYU) impactor, and the Infinite Horizon (IH) impactor. Although various devices and protocols have been used to generate consistent injury severities, further investigation of the relationship between the key parameters of different spinal cord injury (SCI) contusion devices (e.g., drop height in the NYU impactor and impact force in the IH impactor) will improve our understanding of SCI mechanisms. A three-dimensional finite element model of the rat spinal cord from T9 to T10 that included the white and gray matters, dura mater, and cerebrospinal fluid was developed to investigate the von-Mises stress, maximum principal strain, and maximum displacement of the spinal cord for the drop height in the NYU impactor and the impact force in the IH impactor. A quantitative relationship was established as a conversion equation between two key parameters--i.e., the drop height and the impact force--in the NYU and IH impactors from regression equations for peak von-Mises stress, peak maximum principal strain, and maximum displacement in the spinal cord with respect to drop height and impact force with very high coefficients of determination. The consistent correlation was represented as a simple equation (Force = (28.2 ± 3.2) · Height((0.83 ± 0.07))) under the experimental conditions of a 10-g rod in the NYU impactor and an impact velocity of 125 mm/sec in the IH impactor. Thus, the key biomechanical parameter for a contusion device can be converted or translated to that of another device to analyze experimental results from multiple contusion devices.

  20. Closed Loop Terminal Guidance Navigation for a Kinetic Impactor Spacecraft

    NASA Technical Reports Server (NTRS)

    Bhaskaran, Shyam; Kennedy, Brian

    2013-01-01

    A kinetic impactor spacecraft is a viable method to deflect an asteroid which poses a threat to the Earth. The technology to perform such a deflection has been demonstrated by the Deep Impact (DI) mission, which successfully collided with comet Tempel 1 in July 2005 using an onboard autonomous navigation system, called AutoNav, for the terminal phase of the mission. In this paper, we evaluate the ability of AutoNav to impact a wide range of scenarios that an deflection mission could encounter, varying parameters such as the approach velocity, phase angle, size of the asteroid, and the determination of spacecraft attitude. Using realistic Monte Carlo simulations, we tabulated the probability of success of the deflection as a function of these parameters, and the highest sensitivity to be due the spacecraft attitude determination mode. In addition, we also specifically analyzed the impact probability for a proposed mission which would send an impactor to the asteroid 1999RQ36. We conclude with some recommendations for future work.

  1. Closed Loop Terminal Guidance Navigation for a Kinetic Impactor Spacecraft

    NASA Technical Reports Server (NTRS)

    Bhaskaran, Shyam; Kennedy, Brian

    2013-01-01

    A kinetic impactor spacecraft is a viable method to deflect an asteroid which poses a threat to the Earth. The technology to perform such a deflection has been demonstrated by the Deep Impact (DI) mission, which successfully collided with comet Tempel 1 in July 2005 using an onboard autonomous navigation system, called AutoNav, for the terminal phase of the mission. In this paper, we evaluate the ability of AutoNav to impact a wide range of scenarios that an deflection mission could encounter, varying parameters such as the approach velocity, phase angle, size of the asteroid, and the determination of spacecraft attitude. Using realistic Monte Carlo simulations, we tabulated the probability of success of the deflection as a function of these parameters, and the highest sensitivity to be due the spacecraft attitude determination mode. In addition, we also specifically analyzed the impact probability for a proposed mission which would send an impactor to the asteroid 1999RQ36. We conclude with some recommendations for future work.

  2. The cometary and asteroidal impactor flux at the earth

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.

    1988-01-01

    The cratering records on the Earth and the lunar maria provide upper limits on the total impactor flux at the Earth's orbit over the past 600 Myr and the past 3.3 Gyr, respectively. These limits can be compared with estimates of the expected cratering rate from observed comets and asteroids in Earth-crossing orbits, corrected for observational selection effects and incompleteness, and including expected temporal variations in the impactor flux. Both estimates can also be used to calculate the probability of large impacts which may result in biological extinction events on the Earth. The estimated cratering rate on the Earth for craters greater than 10 km-diameter, based on counted craters on dated surfaces is 2.2 + or - 1.1 x 10 to the minus 14th power km(-2) yr(-1) (Shoemaker et al., 1979). Using a revised mass distribution for cometary nuclei based on the results of the spacecraft flybys of Comet Halley in 1986, and other refinements in the estimate of the cometary flux in the terrestrial planets zone, it is now estimated that long-period comets account for 11 percent of the cratering on the Earth (scaled to the estimate above), and short-period comets account for 4 pct (Weissman, 1987). However, the greatest contribution is from large but infrequent, random cometary showers, accounting for 22 pct of the terrestrial cratering.

  3. Characterization of a Regenerable Impactor Filter for Spacecraft Cabin Applications

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.; Vijayakumar, R.

    2015-01-01

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

  4. Good Cascade Impactor Practice (GCIP) and considerations for "in-use" specifications.

    PubMed

    Nichols, S C; Mitchell, J P; Shelton, C M; Roberts, D L

    2013-03-01

    The multi-stage cascade impactor (CI) is widely used to determine aerodynamic particle size distributions (APSDs) of orally inhaled products. Its size-fractionating capability depends primarily on the size of nozzles of each stage. Good Cascade Impactor Practice (GCIP) requires that these critical dimensions are linked to the accuracy of the APSD measurement based on the aerodynamic diameter size scale. Effective diameter (Deff) is the critical dimension describing any nozzle array, as it is directly related to stage cut-point size (d50). d50 can in turn be determined by calibration using particles of known aerodynamic diameter, providing traceability to the international length standard. Movements in Deff within manufacturer tolerances for compendial CIs result in the worst case in shifts in d50 of <±10%. Stage mensuration therefore provides satisfactory control of measurement accuracy. The accurate relationship of Deff to d50 requires the CI system to be leak-free, which can be checked by sealing the apparatus at the entry to the induction port and isolating it from the vacuum source and measuring the rate of pressure rise before each use. Mensuration takes place on an infrequent basis compared with the typical interval between individual APSD determinations. Measurement of stage flow resistance (pressure drop; ΔPstage) could enable the user to know that the CI stages are fit for use before every APSD measurement, by yielding an accurate measure of Deff. However, more data are needed to assess the effects of wear and blockage before this approach can be advocated as part of GCIP.

  5. Inertial deposition of nanoparticle chain aggregates: Theory and comparison with impactor data for ultrafine atmospheric aerosols

    NASA Astrophysics Data System (ADS)

    Barone, Teresa L.; Lall, Anshuman Amit; Zhu, Yifang; Yu, Rong-Chung; Friedlander, Sheldon K.

    2006-10-01

    Nanoparticle chain aggregates (NCAs) are often sized and collected using instruments that rely on inertial transport mechanisms. The instruments size segregate aggregates according to the diameter of a sphere with the same aerodynamic behavior in a mechanical force field. A new method of interpreting the aerodynamic diameter of NCAs is described. The method can be used to calculate aggregate surface area or volume. This is useful since inertial instruments are normally calibrated for spheres, and the calibrations cannot be directly used to calculate aggregate properties. A linear relationship between aggregate aerodynamic diameter and primary particle diameter based on published Monte-Carlo drag calculations is derived. The relationship shows that the aggregate aerodynamic diameter is independent of the number of primary particles that compose an aggregate, hence the aggregate mass. The analysis applies to aggregates with low fractal dimension and uniform primary particle diameter. This is often a reasonable approximation for the morphology of nanoparticles generated in high temperature gases. An analogy is the use of the sphere as an approximation for compact particles. The analysis is applied to the collection of NCAs by a low-pressure impactor. Our results indicate the low-pressure impactor collects aggregates with a known surface area per unit volume on each stage. Combustion processes often produce particles with aggregate structure. For diesel exhaust aggregates, the surface area per unit volume calculated by our method was about twice that of spheres with diameter equal to the aerodynamic diameter. Measurements of aggregates collected near a major freeway and at Los Angeles International Airport (LAX) were made for two aerodynamic cutoff diameter diameters ( d a,50), 50 and 75 nm. (Aerodynamic cutoff diameter refers to the diameter of particles collected with 50% efficiency on a low-pressure impactor stage.) Near-freeway aggregates were probably primarily a

  6. Comparison of the TSI Model 3306 Impactor Inlet with the Andersen Cascade Impactor: solution metered dose inhalers.

    PubMed

    Myrdal, Paul B; Stein, Stephen W; Mogalian, Erik; Hoye, William; Gupta, Abhishek

    2004-09-01

    The product performance of a series of solution Metered Dose Inhalers (MDIs) were evaluated using the TSI Model 3306 Impactor Inlet and the Andersen Cascade Impactor (ACI). The goal of the study was to test whether the fine particle and coarse particle depositions obtained using the Model 3306 were comparable to those results obtained by ACI testing. The analysis using the Model 3306 was performed as supplied by the manufacturer as well as with 20 cm and 40 cm vertical extensions that were inserted between the Model 3306 and the USP Inlet. Nine different solution formulations were evaluated. The drug concentrations ranged from 0.08 to 0.8% w/w and the ethanol cosolvent concentration varied between 5 and 20% w/w. In general, it was found that good correlations between the two instruments were obtained. However, for formulations containing 10-20% w/w ethanol it is shown that an extension fitted to the Model 3306 yielded an improved correlation to those obtained from the ACI.

  7. Precipitation and Hydrology Experiment Counter-Flow Spectrometer and Impactor Field Campaign Report

    SciTech Connect

    Poellot, Michael

    2016-03-01

    The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerial Facility (ARM AAF) counter-flow spectrometer and impactor (CSI) probe was flown on the University of North Dakota Cessna Citation research aircraft during the Integrated Precipitation and Hydrology Experiment (IPHEX). The field campaign took place during May and June of 2014 over North Carolina and its coastal waters as part of a National Aeronautics and Space Administration (NASA) Global Precipitation Measurement validation campaign. The CSI was added to the Citation instrument suite to support the involvement of Jay Mace through the NASA Advanced Composition Explorer (ACE) satellite program and flights of the NASA ER-2 aircraft, which is a civilian version of the Air Force’s U2-S reconnaissance platform. The ACE program funded extra ER-2 flights to focus on clouds that are weakly precipitating, which are also of interest to the Atmospheric System Research program sponsored by DOE.

  8. Europa's small impactor flux and seismic detection predictions

    NASA Astrophysics Data System (ADS)

    Tsuji, Daisuke; Teanby, Nicholas A.

    2016-10-01

    Europa is an attractive target for future lander missions due to its dynamic surface and potentially habitable sub-surface environment. Seismology has the potential to provide powerful new constraints on the internal structure using natural sources such as faults or meteorite impacts. Here we predict how many meteorite impacts are likely to be detected using a single seismic station on Europa to inform future mission planning efforts. To this end, we derive: (1) the current small impactor flux on Europa from Jupiter impact rate observations and models; (2) a crater diameter versus impactor energy scaling relation for icy moons by merging previous experiments and simulations; and (3) scaling relations for seismic signal amplitudes as a function of distance from the impact site for a given crater size, based on analogue explosive data obtained on Earth's ice sheets. Finally, seismic amplitudes are compared to predicted noise levels and seismometer performance to determine detection rates. We predict detection of 0.002-20 small local impacts per year based on P-waves travelling directly through the ice crust. Larger regional and global-scale impact events, detected through mantle-refracted waves, are predicted to be extremely rare (10-8-1 detections per year), so are unlikely to be detected by a short duration mission. Estimated ranges include uncertainties from internal seismic attenuation, impactor flux, and seismic amplitude scaling. Internal attenuation is the most significant unknown and produces extreme uncertainties in the mantle-refracted P-wave amplitudes. Our nominal best-guess attenuation model predicts 0.002-5 local direct P detections and 6 × 10-6-0.2 mantle-refracted detections per year. Given that a plausible Europa landed mission will only last around 30 days, we conclude that impacts should not be relied upon for a seismic exploration of Europa. For future seismic exploration, faulting due to stresses in the rigid outer ice shell is likely to be a

  9. Composition and Origin of Theia - the Moon-Forming Impactor

    NASA Astrophysics Data System (ADS)

    Jacobson, S. A.; Rubie, D. C.; Morbidelli, A.; Young, E. D.

    2016-12-01

    Both the proto-Earth and the Moon-forming impactor, so-called Theia, determine the composition and initial chemistry of the proto-lunar disk. The proto-lunar disk is derived from the mantle of the proto-Earth as well as the core and mantle of Theia. While the exact relative ratios of each component in the proto-lunar disk vary according to different giant impact scenarios, establishing the compositions of each reservoir is a necessary first step. Here we combine dynamical and planetary accretion models to examine the origin, evolution and final composition of Theia in a diverse number of terrestrial planet formation scenarios. In these models, the Theia-like embryo is defined simply as the last giant impactor on the Earth-like planet in each simulation. While many Theia-like embryos are approximately Mars mass and are not the products of giant impacts themselves, some are. Furthermore, while Theia-like embryos accrete planetesimals from a distribution similar to that of the Earth-like planet, their mass is typically dominated by at most a handful of embryos but often just a single embryo. Whether the Theia-like embryo has significant water content is a function of its original accretion/growth location and the timing of its impact onto the Earth-like planet. Across different simulations, later last giant impacts onto the Earth tend to have wetter Theia-like impactors. The original accretion/growth location of the Theia-like embryo strongly determines the FeO content (a stand in for the oxygen fugacity) of its mantle, and thus the partitioning of moderately siderophile elements. If the Theia-like embryo is grown from multiple embryos, then an averaging effect occurs due to the strong radial mixing found in terrestrial planet formation simulations and the Theia-like embryo increasingly resembles the Earth-like planet with respect to mantle composition. The next step will be to understand if the differing FeO contents of the Earth's and the Moon's mantle ( 8% vs. 12

  10. LDEF impact craters formed by carbon-rich impactors

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Dibrozolo, F. Radicati; Fleming, Ronald H.; Harris, David W.; Brownlee, Don E.; Reilly, Terrence W.

    1991-01-01

    Two small craters (number 74, 119 microns, and number 31, 158 microns in diameter) with depth to diameter ratios of about 0.59 and 0.8, respectively, were found in Al from the Long Duration Exposure Facility (LDEF) experiment tray A11EOOF). Both craters have residues concentrated in the crater bottoms, along the walls, and on top of the overturned rims. Low voltage scanning electron electron microscopy, Auger electron spectroscopy, time of flight secondary ion mass spectroscopy and energy dispersive x-ray spectroscopy were used to obtain high resolution imagery and elemental analysis. Analyses indicate that the impactor for both craters was carbon-rich, as the residues contain mostly C. Silicon, S, and F in low concentrations are present on the Al surface away from the craters and may be, in part, contaminants.

  11. Comparing Impactor History to Shallow Subduction in South America

    NASA Astrophysics Data System (ADS)

    Skinner, S. M.; Clayton, R. W.

    2011-12-01

    Flat and shallow subduction are proposed to be both caused by buoyant ocean impactors (plateaus, ridges, etc.) and to be part of orogenic cycles. Neither process can explain all instances of shallow subduction (e.g. central Mexico and Cascadia). In this study we use standard plate tectonic reconstruction methods to investigate the spatial and temporal relationship between the subducting Farallon and Nazca plates beneath South America. We reconstruct conjugate features to bathymetric anomalies believed to have been formed on the spreading ridge and track their location and convergence with the South American margin. These are compared to the history of flat subduction as given by Ramos and Folguera (2009). We have found that in detail the subducting anomalies do not correlate well with zones of shallow subduction in space or time.

  12. Flight Operations for the LCROSS Lunar Impactor Mission

    NASA Technical Reports Server (NTRS)

    Tompkins, Paul D.; Hunt, Rusty; D'Ortenzio, Matt D.; Strong, James; Galal, Ken; Bresina, John L.; Foreman, Darin; Barber, Robert; Shirley, Mark; Munger, James; Drucker, Eric

    2010-01-01

    The LCROSS (Lunar CRater Observation and Sensing Satellite) mission was conceived as a low-cost means of determining the nature of hydrogen concentrated at the polar regions of the moon. Co-manifested for launch with LRO (Lunar Reconnaissance Orbiter), LCROSS guided its spent Centaur upper stage into the Cabeus crater as a kinetic impactor, and observed the impact flash and resulting debris plume for signs of water and other compounds from a Shepherding Spacecraft. Led by NASA Ames Research Center, LCROSS flight operations spanned 112 days, from June 18 through October 9, 2009. This paper summarizes the experiences from the LCROSS flight, highlights the challenges faced during the mission, and examines the reasons for its ultimate success.

  13. Ancient impactor components preserved and reworked in martian regolith breccia Northwest Africa 7034

    NASA Astrophysics Data System (ADS)

    Goderis, Steven; Brandon, Alan D.; Mayer, Bernhard; Humayun, Munir

    2016-10-01

    Northwest Africa (NWA) 7034 and paired stones represent unique samples of martian polymict regolith breccia. Multiple breccia subsamples characterized in this work confirm highly siderophile element (HSE: Re, Os, Ir, Ru, Pt, Pd) contents that are consistently elevated (e.g., Os ∼9.3-18.4 ppb) above indigenous martian igneous rocks (mostly <5 ppb Os), equivalent to ∼3 wt% of admixed CI-type carbonaceous chondritic material, and occur in broadly chondrite-relative proportions. However, a protracted history of impactor component (metal and sulfide) breakdown and redistribution of the associated HSE has masked the original nature of the admixed meteorite signatures. The present-day 187Os/188Os ratios of 0.119-0.136 record a wider variation than observed for all major chondrite types. Combined with the measured 187Re/188Os ratios of 0.154-0.994, the range in Os isotope ratios indicates redistribution of Re and Os from originally chondritic components early in the history of the regolith commencing at ∼4.4 Ga. Superimposed recent Re mobility reflects exposure and weathering at or near the martian and terrestrial surfaces. Elevated Os concentrations (38.0 and 92.6 ppb Os), superchondritic Os/HSE ratios, and 187Os/188Os of 0.1171 and 0.1197 measured for two subsamples of the breccia suggest the redistribution of impactor material at ∼1.5-1.9 Ga, possibly overlapping with a (partial) resetting event at ∼1.4 Ga recorded by U-Pb isotope systematics in the breccia. Martian alteration of the originally chondritic HSE host phases, to form Os-Ir-rich nuggets and Ni-rich pyrite, implies the influence of potentially impact-driven hydrothermal systems. Multiple generations of impactor component admixture, redistribution, and alteration mark the formation and evolution of the martian regolith clasts and matrix of NWA 7034 and paired meteorites, from the pre-Noachian until impact ejection to Earth.

  14. Predictions and Validation of CFX 4.4 Computer Program for the Standard Inertial Impactor

    SciTech Connect

    Hari, Sridhar; Hassan, Y.A.; McFarland, A.R.

    2002-07-01

    The performance of the standard Inertial Impactor was simulated using the CFX 4.4 computer program. Simulations were carried out for three different Reynolds numbers 10, 100 and 3000 and the characteristic Impactor efficiency curve was obtained for each case. Reasonable agreement was obtained between the code predictions and the available data. (authors)

  15. Hypervelocity impact survivability experiments for carbonaceous impactors, part 2

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Paque, Julie M.; Becker, Luann; Vedder, James F.; Erlichman, Jozef

    1995-01-01

    Hypervelocity impact experiments were performed to further test the survivability of carbonaceous impactors and to determine potential products that may have been synthesized during impact. Diamonds were launched by the Ames two-stage light gas gun into Al plate at velocities of 2.75 and 3.1 km sec(exp -1). FESEM imagery confirms that diamond fragments survived in both experiments. Earlier experiments found that diamonds were destroyed on impact above 4.3 km sec(exp -1). Thus, the upper stability limit for diamond on impact into Al, as determined from our experimental conditions, is between 3.1 and 4.3 km sec(exp -1). Particles of the carbonaceous chondrite Nogoya were also launched into Al at a velocity of 6.2 km sec (exp -1). Laser desorption (L (exp 2) MS) analyses of the impactor residues indicate that the lowest and highest mass polycyclic aromatic hydrocarbons (PAH's) were largely destroyed on impact; those of intermediate mass (202-220 amu) remained at the same level or increased in abundance. In addition, alkyl-substituted homologs of the most abundant pre-impacted PAH's were synthesized during impact. These results suggest that an unknown fraction of some organic compounds can survive low to moderate impact velocities and that synthesized products can be expected to form up to velocities of, at least, 6.5 km sec(exp -1). We also present examples of craters formed by a unique microparticle accelerator that could launch micron-sized particles of almost any coherent material at velocities up to approximately 15 km sec(exp -1). Many of the experiments have a direct bearing on the interpretation of LDEF craters.

  16. The current impactor flux on Mars and its seasonal variation

    NASA Astrophysics Data System (ADS)

    JeongAhn, Youngmin; Malhotra, Renu

    2014-11-01

    We calculate the current impactor flux on Mars and its variation over the Martian year, using the available data on the orbital distribution of known Mars-crossing minor planets. To mitigate the problem of observational incompleteness, we adopt the orbital distribution of the nearly complete set of bright (absolute magnitude H<16) Mars-crossers as the intrinsic orbital distribution of the impactor population, and we use this distribution to generate a large number of clones to simulate the impact flux. We use the Öpik-Wetherill formulation for calculating collision probabilities. Our study pays careful attention to the effects of the non-uniform distribution of the perihelion longitudes (owed to planetary secular perturbations) and the non-uniform distribution of impact velocities. We find that these previously neglected non-uniformities have a significant effect on the mean annual impact flux as well as its seasonal variation. The impact flux peaks when Mars is at aphelion. The near-alignment of Mars' eccentricity vector with the mean direction of the eccentricity vector distribution of Mars-crossers causes the mean annual impact flux as well as the amplitude of the seasonal variation to be significantly lower than the estimate based on a uniform random distribution of perihelion longitudes of Mars-crossers. Extrapolation of our results to a de-biased population model of fainter (smaller) Mars-crossers provides theoretical predictions that can be tested with observational data of impacts that is becoming available from spacecraft currently in orbit about Mars.This research was supported by NSF grant #AST-1312498.

  17. Hypervelocity impact survivability experiments for carbonaceous impactors, part 2

    SciTech Connect

    Bunch, T.E.; Paque, J.M.; Becker, L.; Vedder, J.F.; Erlichman, J. ||

    1995-02-01

    Hypervelocity impact experiments were performed to further test the survivability of carbonaceous impactors and to determine potential products that may have been synthesized during impact. Diamonds were launched by the Ames two-stage light gas gun into Al plate at velocities of 2.75 and 3.1 km sec(exp -1). FESEM imagery confirms that diamond fragments survived in both experiments. Earlier experiments found that diamonds were destroyed on impact above 4.3 km sec(exp -1). Thus, the upper stability limit for diamond on impact into Al, as determined from our experimental conditions, is between 3.1 and 4.3 km sec(exp -1). Particles of the carbonaceous chondrite Nogoya were also launched into Al at a velocity of 6.2 km sec (exp -1). Laser desorption (L (exp 2) MS) analyses of the impactor residues indicate that the lowest and highest mass polycyclic aromatic hydrocarbons (PAH`s) were largely destroyed on impact; those of intermediate mass (202-220 amu) remained at the same level or increased in abundance. In addition, alkyl-substituted homologs of the most abundant pre-impacted PAH`s were synthesized during impact. These results suggest that an unknown fraction of some organic compounds can survive low to moderate impact velocities and that synthesized products can be expected to form up to velocities of, at least, 6.5 km sec(exp -1). The authors also present examples of craters formed by a unique microparticle accelerator that could launch micron-sized particles of almost any coherent material at velocities up to approximately 15 km sec(exp -1). Many of the experiments have a direct bearing on the interpretation of LDEF craters.

  18. Craters Clusters on Mars: Atmospheric Dispersion of Small Impactors

    NASA Astrophysics Data System (ADS)

    Melosh, H. J.; McEwen, A. S.

    2007-12-01

    The HiRISE imager aboard the Mars Reconnaissance Orbiter has imaged 18 of the 20 small dark areas that correspond to fresh impact scars on the surface of Mars, reported by Malin et al in 2006 to have appeared after 1999. Operating at a resolution of approximately 30 cm/pixel, HiRISE revealed that the largest of these craters contains eolian ripples and is probably more than just a few years old. The other dark halos often contain clusters of small impact craters with diameters ranging from 1 to 30 m in diameter. About half of these are clusters of 3-10 craters, with one cluster of more than 1,000 craters near 10 m diameter. The dispersion of the clusters is typically less than 100 m, although the largest cluster, whose craters exhibit clear signs of oblique impact, spreads almost 500 m. The size and dispersion of these clusters is consistent with dispersion of incoming meteoroids by atmospheric fragmentation at an altitude of about 20 km. Modeling of the atmospheric fragmentation and impact process shows that the size of the incoming meteoroids is in the range of 0.3 to 1 m (15 m for the largest, older crater), bulk density near 2000 kg/m3 and strength 0.5 to 1 bar, consistent with the properties of terrestrial or Venusian stony impactors. Small crater clusters on Mars are thus consistent with the theory for atmospheric dispersion of impactors observed on Earth and Venus, whose mean dispersions are typically 1 km and 10 km, proportional to the square root of surface atmospheric density.

  19. The FBI Takes Aim at AIM

    ERIC Educational Resources Information Center

    Kanter, Elliot

    1977-01-01

    The events and revelations before and since the arrest of Paul Skyhorse and Richard Mohawk (two American Indian Movement organizers charged with the 1974 murder of a taxi driver at AIM Camp 13) lead to the inevitable conclusion that these men are victims of a frame-up. (Author/JC)

  20. Targeting the (3.8-4.0 Ga) Impactors: Siderophile Element Signatures of Lunar Impact Melts

    NASA Astrophysics Data System (ADS)

    Bennett, V.; Norman, M.; Ryder, G.

    2001-12-01

    Significant gaps remain in our understanding of the early impact history of the Earth and Moon, and their influence on geologic and biologic development. Outstanding controversies include whether or not the Moon, and by inference the early Earth, was hit by an unusually heavy "terminal cataclysm" of collisions during the period 3.8 to 4.0 Ga, and the number of large impact events represented by lunar samples. Coincidentally or not, the large nearside lunar basins are almost identical in age with the oldest terrestrial rocks, and are therefore relevant for consideration of the possible role of impacts in shaping the terrestrial continents and early life environments. To improve our understanding of the impact history of the Moon and to provide new information about the types of planetesimals that were involved in the early impact history of the inner Solar System, we measured the concentrations of highly siderophile elements (HSE: Re, Ir, Pt, Pd, Ru) in a suite of Apollo 17 impact melt breccias using high precision ID-ICPMS methods. These breccias all have poikilitic textures, relatively mafic bulk compositions, and high levels of incompatible trace elements and all likely represent ejecta from the Serenitatis basin. Ar-Ar ages are consistent with the formation of these breccias in a single impact event at 3893 +/- 9 Ma. HSE from 11 representative samples have W-shaped patterns on CI-normalized diagrams, with enrichments in Re, Ru and Pd relative to Ir and Pt, and absolute abundances ranging from \\sim0.5 to 4% of CI reference values. Stronger depletions of Ir and Pt relative to Re, Ru, and Pd are correlated with decreasing HSE concentrations. The samples with the highest HSE concentrations have patterns that are identical to those of EH chondrites, but the patterns become increasingly less diagnostic of meteorite group with decreasing concentrations. The systematic variation of HSE patterns with decreasing concentration suggests that simple chemical fingerprints of

  1. Aerodynamic characteristics of nebulized terbutaline sulphate using the Andersen Cascade Impactor compared to the Next Generation Impactor.

    PubMed

    Abdelrahim, Mohamed E

    2011-04-01

    Characterization of the aerosol emitted from nebulizers is determined using the Next Generation Impactor (NGI). The Andersen Cascade Impactor (ACI) was previously used but the limitation of high flow rate used decreased its uses. We have investigated the use of ACI with different operational conditions compared to the NGI methodology. NGI was operated at a flow rate of 15 L min⁻¹ after cooling at 5°C for 90 min. ACI was operated using flow rates 15 and 28.3 L min⁻¹ at room (ROOM) temperature and after cooling at 5 °C for 60 min (COLD). ACI was also operated using a flow rate 15 L min⁻¹ through the nebulizer T-piece with a flow rate 28.3 L min⁻¹ through ACI (15 Mix) using the mixing valve at ROOM and COLD. Two nebulizer systems, the Sidestream (SIDE) and the Aeroneb Pro (AERO) were used to nebulize terbutaline sulphate respiratory solution. Overall there was a highly significant difference (P < 0.001) between different ACI operating conditions for FPF and MMAD of both nebulizer systems. The ACI at higher flow rate increased the evaporation effect whilst cooling minimized evaporation of both nebulizer systems. Hence cooling and using slow flow rate minimizes evaporation effects with ACI. The ACI 15COLD results were similar to that of NGI. That supports the use of ACI at inhalation flow rate 15 L min⁻¹ without fear of domination of gravity on ACI stages.

  2. Evaluation of the TSI aerosol impactor 3306/3321 system using a redesigned impactor stage with solution and suspension metered-dose inhalers.

    PubMed

    Harris, Julie A; Stein, Stephen W; Myrdal, Paul B

    2006-03-01

    The purpose of this research was to evaluate a redesigned impactor stage for the TSI Model 3306 Impactor Inlet with nozzles adjusted to obtain a target cut-point of 4.7 μm. It has been determined that the previous cut-point used in the Model 3306 was nominally closer to 4.14 μm, thus potentially impacting the characterization of aerosol mass. The reassessment of the Model 3306 was performed on 4 solution and 2 suspension metered-dose inhaler (MDI) formulations. The redesigned impactor stage resulted in a 5% to 6% increase in aerosol mass when compared with the previous impactor stage for the products Ventolin-HFA, Proventil-HFA, and 2 cyclosporin solution formulations with high ethanol concentrations (15% wt/wt). For the formulations with low ethanol concentrations (3% wt/wt), minimal differences were observed between the 2 cut-points. In addition, this study reevaluated the requirement of a vertical inlet extension length when using the TSI 3306/3321 system with the redesigned cut-point. It was shown that the use of a 20-cm extension provides mass and aerosol size distributions that are comparable to the Andersen 8-stage Cascade Impactor, for both solution and suspension MDIs. This work indicates that the TSI 3306/3321 system is suitable for preformulation studies of both suspension and solution MDI systems.

  3. Evaluation of the TSI aerosol impactor 3306/3321 system using a redesigned impactor stage with solution and suspension metered-dose inhalers.

    PubMed

    Harris, Julie A; Stein, Stephen W; Myrdal, Paul B

    2006-03-10

    The purpose of this research was to evaluate a redesigned impactor stage for the TSI Model 3306 Impactor Inlet with nozzles adjusted to obtain a target cut-point of 4.7 microm. It has been determined that the previous cut-point used in the Model 3306 was nominally closer to 4.14 microm, thus potentially impacting the characterization of aerosol mass. The reassessment of the Model 3306 was performed on 4 solution and 2 suspension metered-dose inhaler (MDI) formulations. The redesigned impactor stage resulted in a 5% to 6% increase in aerosol mass when compared with the previous impactor stage for the products Ventolin-HFA, Proventil-HFA, and 2 cyclosporin solution formulations with high ethanol concentrations (15% wt/wt). For the formulations with low ethanol concentrations (3% wt/wt), minimal differences were observed between the 2 cut-points. In addition, this study reevaluated the requirement of a vertical inlet extension length when using the TSI 3306/3321 system with the redesigned cut-point. It was shown that the use of a 20-cm extension provides mass and aerosol size distributions that are comparable to the Andersen 8-stage Cascade Impactor, for both solution and suspension MDIs. This work indicates that the TSI 3306/3321 system is suitable for preformulation studies of both suspension and solution MDI systems.

  4. Improvement of health status evaluated by Arthritis Impact Measurement Scale 2 (AIMS-2) and Short Form-36 (SF-36) in patients with rheumatoid arthritis treated with tocilizumab.

    PubMed

    Fusama, Mie; Nakahara, Hideko; Hamano, Yoshimasa; Nishide, Masayuki; Kawamoto, Keisuke; Hosokawa, Takashi; Nozato, Satoko; Higa, Shinji; Igarashi, Tsuyoshi; Takeuchi, Eiji; Kuroiwa, Takanori; Shimaoka, Yasunori; Yukioka, Masao; Miura, Yasushi; Higashi, Kayoko; Kuritani, Taro; Maeda, Keiji

    2013-03-01

    To evaluate the improvement of health status in patients with rheumatoid arthritis (RA) treated with tocilizumab. Thirty-nine patients were treated with 8 mg/kg tocilizumab every 4 weeks for 24 weeks. Disease activity was assessed by Clinical Disease Activity Index (CDAI) and Simplified Disease Activity Index (SDAI). Improvement of health status was assessed by Arthritis Impact Measurement Scale 2 (AIMS-2) and Short Form-36 (SF-36). Tocilizumab improved CDAI and SDAI significantly at week 4 compared with at baseline. In the components of AIMS-2, "physical score", "symptom" and "affect" improved significantly at week 4 compared with at baseline, while "social interaction" did not improve significantly during 24 weeks of tocilizumab therapy. Similarly in SF-36, "bodily pain", "general health", "vitality" and "mental health" improved significantly at week 4. The most correlative component of AIMS-2 with CDAI was "symptom", while "social interaction" did not correlate with CDAI during tocilizumab treatment. The time-course diversity in improvement of health status should be considered to provide proper healthcare when treated with tocilizumab.

  5. Precision disablement aiming system

    SciTech Connect

    Monda, Mark J.; Hobart, Clinton G.; Gladwell, Thomas Scott

    2016-02-16

    A disrupter to a target may be precisely aimed by positioning a radiation source to direct radiation towards the target, and a detector is positioned to detect radiation that passes through the target. An aiming device is positioned between the radiation source and the target, wherein a mechanical feature of the aiming device is superimposed on the target in a captured radiographic image. The location of the aiming device in the radiographic image is used to aim a disrupter towards the target.

  6. Developing Supersonic Impactor and Aerodynamic Lens for Separation and Handling of Nano-Sized Particles

    SciTech Connect

    Goodarz Ahmadi

    2008-06-30

    A computational model for supersonic flows of compressible gases in an aerodynamic lens with several lenses and in a supersonic/hypersonic impactor was developed. Airflow conditions in the aerodynamic lens were analyzed and contour plots for variation of Mach number, velocity magnitude and pressure field in the lens were evaluated. The nano and micro-particle trajectories in the lens and their focusing and transmission efficiencies were evaluated. The computational model was then applied to design of a aerodynamic lens that could generate focus particle beams while operating under atmospheric conditions. The computational model was also applied to airflow condition in the supersonic/hypersonic impactor. Variations of airflow condition and particle trajectories in the impactor were evaluated. The simulation results could provide understanding of the performance of the supersonic and hypersonic impactors that would be helpful for the design of such systems.

  7. Fabrication of Machined and Shrink Fitted Impactor; Composite Liners for the Los Alamos HEDP Program

    SciTech Connect

    Randolph, B.

    1999-10-19

    Composite liners have been fabricated for the Los Alamos liner driven HEDP experiments using impactors formed by physical vapor deposition (PVD), electroplating, machining and shrink fitting. Chemical vapor deposition (CVD) has been proposed for some ATLAS liner applications. This paper describes the processes used to fabricate machined and shrink fitted impactors which have been used for copper impactors in 1100 aluminum liners and 6061 T-6 aluminum impactors in 1100 aluminum liners. The most successful processes have been largely empirically developed and rely upon a combination of shrink fitted and light press fitting. The processes used to date will be described along with some considerations for future composite liners requirements in the HEDP Program.

  8. Possible Impactor Remnants on Shatter Cone Surfaces from the Steinheim Basin, SW Germany

    NASA Astrophysics Data System (ADS)

    Buchner, E.; Schmieder, M.

    2015-07-01

    Surfaces of Steinheim shatter cones are covered by mineral coatings that consist of Fe, Ni, Co, Cu, Pt, and Au mineral assemblages. A plausible explanation is that they represent impactor matter remobilized in an impact-induced hydrothermal system.

  9. Prediction of imminent impactors: Manifold Of Variations methods

    NASA Astrophysics Data System (ADS)

    Tommei, G.; Milani Comparetti, A.; Spoto, F.; Bernardi, F.

    2014-07-01

    The asteroid impact risk has recently been demonstrated by the Celyabinsk and 2014AA events. In cases, like the two mentioned before, it is important to know, even with very few observations, whether or not there is the possibility of an immediate impact with the Earth. When such small asteroids are discovered, the confidence region resulting from preliminary orbit determination is not elongated in one direction, thus the Line Of Variations (LOV) is not representative of the entire region. If we use for a short arc of observations the attributable elements (A,ρ,dotρ), where A is the attributable, the confidence region is a thin shell surrounding a subset of the Admissible Region (AR). The Manifold Of Variations (MOV) is the set of the points S where the target function has a local minimum with respect to changes of A, for each fixed (ρ, dotρ), with minimum RMS of the residuals below some control Σ. When there is little information beyond A, S is parameterized by (A(ρ,dotρ), ρ,dotρ), defined on a subset B of the (ρ,dotρ) plane: B is an open set, not necessarily connected. Then the surface S can be computed point by point using a cobweb sampling (or a grid); then, each point could be used as Virtual Asteroid (VA) and propagated for some months in the future in order to have the trace of the cobweb (or grid) on the Target Plane (TP) of the immediate impact. In this presentation we are going to - define the MOV tool showing how it is used to predict imminent impactors; - discuss how to assign a Probability Density Function (PDF) to the MOV: this is not a simple problem because we want to take into account the PDF for observations, but also some constraints deriving from population and physical models. Moreover, we will address some examples using data from the NEOCP list of the Minor Planet Center (MPC).

  10. Small carry-on impactor of Hayabusa2 mission

    NASA Astrophysics Data System (ADS)

    Saiki, Takanao; Sawada, Hirotaka; Okamoto, Chisato; Yano, Hajime; Takagi, Yasuhiko; Akahoshi, Yasuhiro; Yoshikawa, Makoto

    2013-03-01

    A Japanese spacecraft, Hayabusa2, the successor of Hayabusa, which came back from the Asteroid Itokawa with sample materials after its 7-year-interplanetary journeys, is a current mission of Japan Aerospace Exploration Agency (JAXA) and scheduled to be launched in 2014. Although its design basically follows Hayabusa, some new components are planned to be equipped in Hayabusa2 mission. A Small Carry-on Impactor (SCI), a small explosive device, is one of the challenges that were not seen with Hayabusa. An important scientific objective of Hayabusa2 is to investigate chemical and physical properties of the internal materials and structures. SCI creates an artificial crater on the surface of the asteroid and the mother spacecraft observes the crater and tries to get sample materials. High kinetic energy is required to creating a meaningful crater. The SCI would become complicated and heavy if the traditional acceleration devices like thrusters and rocket motors are used to hit the asteroid because the acceleration distance is quite large and guidance system is necessary. In order to make the system simpler, a technology of special type of shaped charge is used for the acceleration of the impact head. By using this technology, it becomes possible to accelerate the impact head very quickly and to hit the asteroid without guidance system. However, the impact operation should be complicated because SCI uses powerful explosive and it scatters high speed debris at the detonation. This paper presents the overview of our new small carry-on impact system and the impact operation of Hayabusa2 mission.

  11. Characterisation and airborne deployment of a new counterflow virtual impactor inlet

    NASA Astrophysics Data System (ADS)

    Shingler, T.; Dey, S.; Sorooshian, A.; Brechtel, F. J.; Wang, Z.; Metcalf, A.; Coggon, M.; Mülmenstädt, J.; Russell, L. M.; Jonsson, H. H.; Seinfeld, J. H.

    2012-06-01

    A new counterflow virtual impactor (CVI) inlet is introduced with details of its design, laboratory characterisation tests and deployment on an aircraft during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE). The CVI inlet addresses three key issues in previous designs; in particular, the inlet operates with: (i) negligible organic contamination; (ii) a significant sample flow rate to downstream instruments (∼15 l min-1) that reduces the need for dilution; and (iii) a high level of accessibility to the probe interior for cleaning. Wind tunnel experiments characterised the cut size of sampled droplets and the particle size-dependent transmission efficiency in various parts of the probe. For a range of counter-flow rates and air velocities, the measured cut size was between 8.7-13.1 μm. The mean percentage error between cut size measurements and predictions from aerodynamic drag theory is 1.7%. The CVI was deployed on the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter for thirty flights during E-PEACE to study aerosol-cloud-radiation interactions off the central coast of California in July and August 2011. Results are reported to assess the performance of the inlet including comparisons of particle number concentration downstream of the CVI and cloud drop number concentration measured by two independent aircraft probes. Measurements downstream of the CVI are also examined from one representative case flight coordinated with shipboard-emitted smoke that was intercepted in cloud by the Twin Otter.

  12. Characterization and airborne deployment of a new counterflow virtual impactor inlet

    NASA Astrophysics Data System (ADS)

    Shingler, T.; Dey, S.; Sorooshian, A.; Brechtel, F. J.; Wang, Z.; Metcalf, A.; Coggon, M.; Mülmenstädt, J.; Russell, L. M.; Jonsson, H. H.; Seinfeld, J. H.

    2012-02-01

    A new counterflow virtual impactor (CVI) inlet is introduced with details of its design, laboratory characterization tests, and deployment on an aircraft during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE). The CVI inlet addresses three key issues in previous designs; in particular, the inlet operates with: (i) negligible organic contamination; (ii) a significant sample flow rate to downstream instruments (~15 l min-1) that reduces the need for dilution; and (iii) a high level of accessibility to the probe interior for cleaning. Wind tunnel experiments characterized the cut size of sampled droplets and the particle size-dependent transmission efficiency in various parts of the probe. For a range of counter-flow rates and air velocities, the measured cut size was between 8.7-13.1 μm. The percentage error between cut size measurements and predictions from aerodynamic drag theory are less than 13%. The CVI was deployed on the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter for thirty flights during E-PEACE to study aerosol-cloud-radiation interactions off the central coast of California between July and August 2011. Results are reported to assess the performance of the inlet including comparisons of particle number concentration downstream of the CVI and cloud drop number concentration measured by two independent aircraft probes. Measurements downstream the CVI are also examined from one representative case flight coordinated with shipboard-emitted smoke that was intercepted in cloud by the Twin Otter.

  13. Precision laser aiming system

    DOEpatents

    Ahrens, Brandon R.; Todd, Steven N.

    2009-04-28

    A precision laser aiming system comprises a disrupter tool, a reflector, and a laser fixture. The disrupter tool, the reflector and the laser fixture are configurable for iterative alignment and aiming toward an explosive device threat. The invention enables a disrupter to be quickly and accurately set up, aligned, and aimed in order to render safe or to disrupt a target from a standoff position.

  14. The oxidation state and mass of the Moon-forming impactor

    NASA Astrophysics Data System (ADS)

    Wade, Jon; Wood, Bernard J.

    2016-05-01

    Physical simulations of the origin of the Moon have, until recently, centred on impact, about 100 M.yr after the origin of the solar system, of a Mars-like body (10-20% Earth mass) on a near fully-accreted protoEarth. Although this model provides an explanation of the distribution of mass and moment of inertia of the Earth-Moon system it has recently been found that modification of the initial conditions greatly expands the range of permissible impactor masses. Here we take an alternative approach and consider how the oxidation state and mass of the impactor affect the chemical compositions of the product Earth and Moon. We apply the constraints that silicate Moon is richer in FeO than silicate Earth (9-13% as opposed to 8.05%), that their Hf/W ratios are both ˜25 and that they are virtually identical in isotopes of O, Ti, Si, Ni, Cr and W. We then grow protoEarth using a standard accretionary model which yields the correct mantle abundances of Ni, Co, W, Mo, Nb, V and Cr, and add to this body different masses of impactor. The impactor is assumed to be either highly oxidised (˜18% FeO), highly reduced (˜0.3% FeO) or undifferentiated and chondritic. In order to satisfy the isotopic constraints silicate Moon is assumed to be derived principally from silicate protoEarth. We find that an oxidised or chondritic impactor of ˜ 0.15 ME can satisfy the isotopic constraints (most importantly ɛ182W), FeO contents and Nb/Ta of Earth and Moon, but leads to implausibly low Hf/W of ˜ 12- 16 in silicate Earth and ˜ 4- 6 in silicate Moon. This is because the Moon requires more impactor mantle, with low Hf/W, than Earth to reach its higher FeO content. In contrast, impact of a similar mass (10-20% ME) of highly reduced, Mercury-like impactor on an oxidised protoEarth (˜10.7% FeO in mantle) satisfies the isotopic constraints, FeO contents, Nb/Ta and Hf/W of silicate Earth and Moon given a small amount of post-impact re-equilibration of terrestrial mantle with impactor core

  15. Animation of the AIM Spacecraft

    NASA Image and Video Library

    AIM will make simultaneous measurements of the main ingredients needed to form these clouds and will unravel the role of natural factors, such as the solar cycle and meteorology, from the possible ...

  16. Improved quality control metrics for cascade impaction measurements of orally inhaled drug products (OIPs).

    PubMed

    Tougas, Terrence P; Christopher, David; Mitchell, Jolyon P; Strickland, Helen; Wyka, Bruce; Van Oort, Mike; Lyapustina, Svetlana

    2009-01-01

    This study of aerodynamic mass-weighted particle size distribution (APSD) data from orally inhaled products (OIPs) investigated whether a set of simpler (than currently used) metrics may be adequate to detect changes in APSD for quality control (QC) purposes. A range of OIPs was examined, and correlations between mass median aerodynamic diameter and the ratio of large particle mass (LPM) to small particle mass (SPM) were calculated. For an Andersen cascade impactor, the LPM combines the mass associated with particle sizes from impactor stage 1 to a product-specific boundary size; SPM combines the mass of particles from that boundary through to terminal filter. The LPM-SPM boundary should be chosen during development based on the full-resolution impactor results so as to maximize the sensitivity of the LPM/SPM ratio to meaningful changes in quality. The LPM/SPM ratio along with the impactor-sized mass (ISM) are by themselves sufficient to detect changes in central tendency and area under the APSD curve, which are key in vitro quality attributes for OIPs. Compared to stage groupings, this two-metric approach provides better intrinsic precision, in part due to having adequate mass and consequently better ability to detect changes in APSD and ISM, suggesting that this approach should be a preferred QC tool. Another advantage is the possibility to obtain these metrics from the abbreviated impactor measurements (AIM) rather than from full-resolution multistage impactors. Although the boundary is product specific, the testing could be accomplished with a basic AIM system which can meet the needs of most or all OIPs.

  17. [Aiming for zero blindness].

    PubMed

    Nakazawa, Toru

    2015-03-01

    -independent factors, as well as our investigation of ways to improve the clinical evaluation of the disease. Our research was prompted by the multifactorial nature of glaucoma. There is a high degree of variability in the pattern and speed of the progression of visual field defects in individual patients, presenting a major obstacle for successful clinical trials. To overcome this, we classified the eyes of glaucoma patients into 4 types, corresponding to the 4 patterns of glaucomatous optic nerve head morphology described: by Nicolela et al. and then tested the validity of this method by assessing the uniformity of clinical features in each group. We found that in normal tension glaucoma (NTG) eyes, each disc morphology group had a characteristic location in which the loss of circumpapillary retinal nerve fiber layer thickness (cpRNFLT; measured with optical coherence tomography: OCT) was most likely to occur. Furthermore, the incidence of reductions in visual acuity differed between the groups, as did the speed of visual field loss, the distribution of defective visual field test points, and the location of test points that were most susceptible to progressive damage, measured by Humphrey static perimetry. These results indicate that Nicolela's method of classifying eyes with glaucoma was able to overcome the difficulties caused by the diverse nature of the disease, at least to a certain extent. Building on these findings, we then set out to identify sectors of the visual field that correspond to the distribution of retinal nerve fibers, with the aim of detecting glaucoma progression with improved sensitivity. We first mapped the statistical correlation between visual field test points and cpRNFLT in each temporal clock-hour sector (from 6 to 12 o'clock), using OCT data from NTG patients. The resulting series of maps allowed us to identify areas containing visual field test points that were prone to be affected together as a group. We also used a similar method to identify visual

  18. Thinking Big, Aiming High

    ERIC Educational Resources Information Center

    Berkeley, Viv

    2010-01-01

    What do teachers, providers and policymakers need to do in order to support disabled learners to "think big and aim high"? That was the question put to delegates at NIACE's annual disability conference. Some clear themes emerged, with delegates raising concerns about funding, teacher training, partnership-working and employment for disabled…

  19. AIM High Program Manual.

    ERIC Educational Resources Information Center

    Austin Independent School District, TX.

    The AIM High Program was developed for elementary school children in the Austin (Texas) Independent School District who demonstrate unusually high ability, interest, and motivation in language arts, mathematics, science, and art. Students are identified for the program through standardized test scores, teacher recommendation, student interest,…

  20. Separation and sampling of ice nucleation chamber generated ice particles by means of the counterflow virtual impactor technique for the characterization of ambient ice nuclei.

    NASA Astrophysics Data System (ADS)

    Schenk, Ludwig; Mertes, Stephan; Kästner, Udo; Schmidt, Susan; Schneider, Johannes; Frank, Fabian; Nillius, Björn; Worringen, Annette; Kandler, Konrad; Ebert, Martin; Stratmann, Frank

    2014-05-01

    In 2011, the German research foundation (DFG) research group called Ice Nuclei Research Unit (INUIT (FOR 1525, project STR 453/7-1) was established with the objective to achieve a better understanding concerning heterogeneous ice formation. The presented work is part of INUIT and aims for a better microphysical and chemical characterization of atmospheric aerosol particles that have the potential to act as ice nuclei (IN). For this purpose a counterflow virtual impactor (Kulkarni et al., 2011) system (IN-PCVI) was developed and characterized in order to separate and collect ice particles generated in the Fast Ice Nucleus Chamber (FINCH; Bundke et al., 2008) and to release their IN for further analysis. Here the IN-PCVI was used for the inertial separation of the IN counter produced ice particles from smaller drops and interstitial particles. This is realized by a counterflow that matches the FINCH output flow inside the IN-PCVI. The choice of these flows determines the aerodynamic cut-off diameter. The collected ice particles are transferred into the IN-PCVI sample flow where they are completely evaporated in a particle-free and dry carrier air. In this way, the aerosol particles detected as IN by the IN counter can be extracted and distributed to several particle sensors. This coupled setup FINCH, IN-PCVI and aerosol instrumentation was deployed during the INUIT-JFJ joint measurement field campaign at the research station Jungfraujoch (3580m asl). Downstream of the IN-PCVI, the Aircraft-based Laser Ablation Aerosol Mass Spectrometer (ALABAMA; Brands et al., 2011) was attached for the chemical analysis of the atmospheric IN. Also, number concentration and size distribution of IN were measured online (TROPOS) and IN impactor samples for electron microscopy (TU Darmstadt) were taken. Therefore the IN-PCVI was operated with different flow settings than known from literature (Kulkarni et al., 2011), which required a further characterisation of its cut

  1. Design and calibration of an in-stack, low-pressure impactor. Final report, January 1985-October 1987

    SciTech Connect

    Lundgren, D.A.; Vanderpool, R.W.

    1989-03-01

    The purpose of this project was to design, fabricate, calibrate, and field test a low-pressure impactor for sampling and size-classifying particulate exhaust from jet-engine test cells. This report covers all aspects of the effort through an actual field test on a J79-type engine exhaust. A computer code for user prediction of impactor stage outputs is included as well as design drawings for impactor fabrication.

  2. Design and Use of a Guided Weight Impactor to Impart Barely Visible Impact Damage

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.; Przekop, Adam

    2016-01-01

    Aircraft structure is required to demonstrate satisfaction of the FAR requirements for Category 1, such as barely visible impact damage (BVID). Typical aircraft structure is impacted using a dropped weight impactor, which can impart BVID to the top surface of the structure. A recent test of a multi-bay box (MBB) composite test article, that represents an 80% scale center section of a hybrid wing body aircraft, required impact to be in a direction other than vertical from above, but still in an direction that is normal to the surface. This requirement eliminated the use of the conventional dropped weight impactor. Therefore, a design study was undertaken to determine the most effective way to efficiently and reliably impact the MBB. The chosen design was a guided weight impactor that is gravity driven. This paper describes the design of the guided weight impactor, and presents the results of its use for imparting BVID to the MBB. The guided weight impactor was seen to be a very reliable method to impart BVID, while at the same time having the capability to be highly configurable for use on other aircraft structure that is impacted at a variety of impact energies and from a variety of directions.

  3. Response of laminated composite plates to low-speed impact by different impactors

    NASA Technical Reports Server (NTRS)

    Prasad, Chunchu; Ambur, Damodar R.; Starnes, James H.

    1994-01-01

    An analytic procedure has been developed to determine the transient response of simply supported, retangular laminated composite plates subjected to impact loads from airgun-propelled or drop-weight impactors. A first-order shear deformation theory has been included in the analysis to represent properly any local short-wavelength transient bending response. The impact force has been modeled as a locally distributed load with cosine-cosine distribution. A double Fourier series expansion and the Timoshenko small increment method have been used to determine the contact force, out-of-plane deflections, and in-plane strains and stresses at any plate location due to an impact force at any plate location. The results of experimental and analytical studies are compared for quasi-isotropic laminates. The results indicate the importance of including transverse shear deformation effects in the analysis for predicting the response of laminated plates subjected to both airgun-propelled and dropped-weight impactors. The results also indicate that plate boundary conditions influence the axial strains more significantly than the contact force for a dropped-weight impactor. The results of parametric studies identify a scaling approach based on impactor momentum that may account for the differences in the responses of plates impacted by airgun-propelled or dropped-weight impactors.

  4. Positive-hole correction of multiple-jet impactors for collecting viable microorganisms.

    PubMed

    Macher, J M

    1989-11-01

    Multiple-jet impactors, typically with 200 or 400 holes, are used widely for collecting aerosols of living bacteria and fungi. In this type of impactor, the air jets impinge directly onto nutrient agar in a petri dish which is incubated after sampling until collected cells multiply into colonies. The observed number of colonies can be adjusted for the probability that more than one viable particle was collected through a sampling hole and merged with other microorganisms at an impaction site to produce a single colony. A "positive-hole" correction table has been published for a 400-hole impactor, but none has been produced previously for the 200-hole impactor. The expected number of sampled particles required to fill each of 1 through 200 and 1 through 400 impaction sites and the standard deviations of these values were calculated from probability theory. The results were compared with a Monte Carlo simulation. By using correction tables (which include the standard deviation of an expected value) an investigator can report the most probable viable particle count and a 95% confidence interval (mean +/- 2 standard deviations). The range of collected particles that could have produced an observed number of colonies increases as the number of collected particles increases, and investigators should acknowledge the uncertainty associated with adjusted counts. It is advisable to use an impactor with the greatest practical number of sampling holes because this decreases the likelihood that multiple particles are deposited at the impaction sites.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Application of USP inlet extensions to the TSI impactor system 3306/3320 using HFA 227 based solution metered dose inhalers.

    PubMed

    Mogalian, Erik; Myrdal, Paul Brian

    2005-12-01

    The objective of this study was to further evaluate the need for a vertical inlet extension when testing solution metered dose inhalers using the TSI Model 3306 Impactor Inlet in conjunction with the TSI Model 3320 Aerodynamic Particle Sizer (APS). The configurations tested using the TSI system were compared to baseline measurements that were performed using the Andersen Mark II 8-stage cascade impactor (ACI). Seven pressurized solution metered dose inhalers were tested using varied concentrations of beclomethasone dipropionate (BDP), ethanol, and HFA 227 propellant. The inhalers were tested with the cascade impactor, and with the TSI system. The TSI system had three different configurations as the manufacturer provided (0 cm) or with inlet extensions of 20 and 40 cm. The extensions were located between the USP inlet and the Model 3306 Impactor Inlet. There were no practical differences between each system for the stem, actuator, or USP inlet. The fine particle mass (aerodynamic mass < 4.7 microm) was affected by extension length and correlated well with the ACI when an extension was present. APS particle size measurements were unaffected by the extension lengths and correlated well to particle size determined from the ACI analysis. It has been confirmed that an inlet extension may be necessary for the TSI system in order to give mass results that correlate to the ACI, especially for formulations having significant concentrations of low volatility excipients. Additionally, the results generated from this study were used to evaluate the product performance of HFA 227 based solution formulations that contain varying concentrations of ethanol as a cosolvent.

  6. Science case for the Asteroid Impact Mission (AIM): A component of the Asteroid Impact & Deflection Assessment (AIDA) mission

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; Cheng, A.; Küppers, M.; Pravec, P.; Blum, J.; Delbo, M.; Green, S. F.; Rosenblatt, P.; Tsiganis, K.; Vincent, J. B.; Biele, J.; Ciarletti, V.; Hérique, A.; Ulamec, S.; Carnelli, I.; Galvez, A.; Benner, L.; Naidu, S. P.; Barnouin, O. S.; Richardson, D. C.; Rivkin, A.; Scheirich, P.; Moskovitz, N.; Thirouin, A.; Schwartz, S. R.; Campo Bagatin, A.; Yu, Y.

    2016-06-01

    The Asteroid Impact & Deflection Assessment (AIDA) mission is a joint cooperation between European and US space agencies that consists of two separate and independent spacecraft that will be launched to a binary asteroid system, the near-Earth asteroid Didymos, to test the kinetic impactor technique to deflect an asteroid. The European Asteroid Impact Mission (AIM) is set to rendezvous with the asteroid system to fully characterize the smaller of the two binary components a few months prior to the impact by the US Double Asteroid Redirection Test (DART) spacecraft. AIM is a unique mission as it will be the first time that a spacecraft will investigate the surface, subsurface, and internal properties of a small binary near-Earth asteroid. In addition it will perform various important technology demonstrations that can serve other space missions. The knowledge obtained by this mission will have great implications for our understanding of the history of the Solar System. Having direct information on the surface and internal properties of small asteroids will allow us to understand how the various processes they undergo work and transform these small bodies as well as, for this particular case, how a binary system forms. Making these measurements from up close and comparing them with ground-based data from telescopes will also allow us to calibrate remote observations and improve our data interpretation of other systems. With DART, thanks to the characterization of the target by AIM, the mission will be the first fully documented impact experiment at asteroid scale, which will include the characterization of the target's properties and the outcome of the impact. AIDA will thus offer a great opportunity to test and refine our understanding and models at the actual scale of an asteroid, and to check whether the current extrapolations of material strength from laboratory-scale targets to the scale of AIDA's target are valid. Moreover, it will offer a first check of the

  7. Three-Dimensional Shapes and Impactor Size Estimation of Stardust Impact

    NASA Technical Reports Server (NTRS)

    Iida, Y.; Tsuchiyama, A.; Kadono, T.; Nakamura, T.; Sakamoto, K.; Nakano, T.; Uesugi, K.; Zolensky, M. E.

    2008-01-01

    Impact tracks formed by cometary dust capture in silica aerogel collectors in the Stardust mission [1] have a variety of shapes, showing diversity of the cometary dust [2]. We have investigated 3-D structures and elemental distributions of three impact tracks using synchrotron radiation x-ray analyses (microtomography and XRF) as one of the preliminary examination [3]. In this study, additional five tracks were investigated by the same analytical method. Impactor sizes of the tracks were estimated from the track entrance sizes and Fe abundances. Size parameters, such as length, of the tracks were normalized by the impactor size to compare track shape

  8. AIMS and resist simulation

    NASA Astrophysics Data System (ADS)

    Strößner, Ulrich; Seitz, Holger; Birkner, Robert; Richter, Rigo; Scherübl, Thomas

    2008-10-01

    The AIMTM45-193i is the established tool for mask performance qualification and defect printing analysis in the mask shop under scanner conditions. Vector effects are taken into account by the proprietary Zeiss vector effect emulator. In several studies an excellent correlation to wafer prints has been reported. However, a systematic offset to wafer prints in terms of mask error enhancement factor (MEEF) and exposure latitude has been observed which is attributed to well known resist effects. The AIMSTM measures the aerial image in resist whereas in a real lithography process further image blur of the latent image is caused by photo acid diffusion during wafer processing and resist development. To explain the gap between the AIMTM and wafer prints we have investigated aerial images in combination with an easy to use resist model. It does take resist effects into account with sufficient accuracy to explain printing behavior of photo masks but without the need to calibrate lots of parameters of the actually used resist which usually are not known to a mask shop. The resist effects predominantly reduce the image contrast and thus increase the MEEF and the sensitivity to mask defects. This somewhat counterintuitive behavior is labeled "contrast enhancement by contrast reduction". Additionally application of the resist model improves the agreement of e.g. the exposure latitude or MEEF measured by the AIMSTM compared to wafer prints.

  9. Organizational performance and regulatory compliance as measured by clinical pertinence indicators before and after implementation of Anesthesia Information Management System (AIMS).

    PubMed

    Choi, Clark K; Saberito, Darlene; Tyagaraj, Changa; Tyagaraj, Kalpana

    2014-01-01

    Previous studies have suggested that electronic medical records (EMR) can lead to a greater reduction of medical errors and better adherence to regulatory compliance than paper medical records (PMR). In order to assess the organizational performance and regulatory compliance, we tracked different clinical pertinence indicators (CPI) in our anesthesia information management system (AIMS) for 5 years. These indicators comprised of the protocols from the Surgical Care Improvement Project (SCIP), elements of performance (EP) from The Joint Commission (TJC), and guidelines from the Centers for Medicare and Medicaid Services (CMS). A comprehensive AIMS was initiated and the CPI were collected from October 5, 2009 to December 31, 2010 (EMR period) and from January 1, 2006 to October 4, 2009 (PMR period). Fourteen CPI were found to be common between the EMR and PMR periods. Based on the statistical analysis of the 14 common CPI, there was a significant increase (p < 0.001) in overall compliance after the introduction of EMR compared to the PMR period. The increase in overall compliance was significantly progressive (p = 0.013) from year to year over 2006 and 2010. Of the 14 CPI, Documentation of a) medication doses, and b) monitoring of postoperative physiological status, mental status, and pain scores showed significant improvement (p < 0.001) during the EMR period compared to the PMR period.

  10. Microscopic impactor debris in the soil around Kamil crater (Egypt): Inventory, distribution, total mass, and implications for the impact scenario

    NASA Astrophysics Data System (ADS)

    Folco, Luigi; D'Orazio, Massimo; Fazio, Agnese; Cordier, Carole; Zeoli, Antonio; Ginneken, Matthias; El-Barkooky, Ahmed

    2015-03-01

    We report on the microscopic impactor debris around Kamil crater (45 m in diameter, Egypt) collected during our 2010 geophysical expedition. The hypervelocity impact of Gebel Kamil (Ni-rich ataxite) on a sandstone target produced a downrange ejecta curtain of microscopic impactor debris due SE-SW of the crater (extending ~300,000 m2, up to ~400 m from the crater), in agreement with previous determination of the impactor trajectory. The microscopic impactor debris include vesicular masses, spherules, and coatings of dark impact melt glass which is a mixture of impactor and target materials (Si-, Fe-, and Al-rich glass), plus Fe-Ni oxide spherules and mini shrapnel, documenting that these products can be found in craters as small as few tens of meters in diameter. The estimated mass of the microscopic impactor debris (<290 kg) derived from Ni concentrations in the soil is a small fraction of the total impactor mass (~10 t) in the form of macroscopic shrapnel. That Kamil crater was generated by a relatively small impactor is consistent with literature estimates of its pre-atmospheric mass (>20 t, likely 50-60 t).

  11. DESIGN AND CALIBRATION OF THE EPA PM 2.5 WELL IMPACTOR NINETY-SIX (WINS)

    EPA Science Inventory

    The EPA well-type impactor ninety-six (WINS) was designed and calibrated to serve as a particle size separation device for the EPA reference method sampler for particulate matter under 2.5 um aerodynamic diameter. The WINS was designed to operate downstream of a PM10 inlet at a...

  12. An estimate of spherical impactor energy transfer for mechanical frequency up-conversion energy harvester

    NASA Astrophysics Data System (ADS)

    Corr, L. R.; Ma, D. T.

    2016-08-01

    Vibration energy harvesters, which use the impact mechanical frequency up-conversion technique, utilize an impactor, which gains kinetic energy from low frequency ambient environmental vibrations, to excite high frequency systems that efficiently convert mechanical energy to electrical energy. To take full advantage of the impact mechanical frequency up-conversion technique, it is prudent to understand the energy transfer from the low frequency excitations, to the impactor, and finally to the high frequency systems. In this work, the energy transfer from a spherical impactor to a multi degree of freedom spring / mass system, due to Hertzian impact, is investigated to gain insight on how best to design impact mechanical frequency up-conversion energy harvesters. Through this academic work, it is shown that the properties of the contact (or impact) area, i.e., radius of curvature and material properties, only play a minor role in energy transfer and that the equivalent mass of the target system (i.e., the spring / mass system) dictates the total amount of energy transferred during the impact. The novel approach of utilizing the well-known Hertzian impact methodology to gain an understanding of impact mechanical frequency up-conversion energy harvesters has made it clear that the impactor and the high frequency energy generating systems must be designed together as one system to ensure maximum energy transfer, leading to efficient ambient vibration energy harvesters.

  13. DESIGN AND CALIBRATION OF THE EPA PM 2.5 WELL IMPACTOR NINETY-SIX (WINS)

    EPA Science Inventory

    The EPA well-type impactor ninety-six (WINS) was designed and calibrated to serve as a particle size separation device for the EPA reference method sampler for particulate matter under 2.5 um aerodynamic diameter. The WINS was designed to operate downstream of a PM10 inlet at a...

  14. A versatile sensor performance evaluation platform with an impactor-inspired sample chamber and virtual pin grid array

    NASA Astrophysics Data System (ADS)

    Field, Christopher R.; Tamanaha, Cy R.; Woytowitz, Morgan; Rose-Pehrsson, Susan L.

    2014-06-01

    We present the details necessary for building a scalable, flexible, and universal sensor performance evaluation platform with an impactor-inspired sample chamber and a virtual pin grid array for maintaining electrical connections. The system is designed to accommodate a wide range of sensors varying in physical dimensions, electrical connections, and transduction mechanisms. By integrating a switch matrix system with a commercial chip carrier, we have built a platform for rapidly screening sensors for promise in military, homeland security, and commercial applications without requiring custom circuits or packages for each sensor technology. Intuitive, graphical software is written and provided to control and monitor temperature, flow rate, and electrical connections. The system is capable of operating and interfacing with a variety of vapor delivery systems for chemical vapor detection measurements of emerging sensor technologies.

  15. Enhancing Bioaerosol Sampling by Andersen Impactors Using Mineral-Oil-Spread Agar Plate

    PubMed Central

    Xu, Zhenqiang; Wei, Kai; Wu, Yan; Shen, Fangxia; Chen, Qi; Li, Mingzhen; Yao, Maosheng

    2013-01-01

    As a bioaerosol sampling standard, Andersen type impactor is widely used since its invention in 1950s, including the investigation of the anthrax attacks in the United States in 2001. However, its related problems such as impaction and desiccation stress as well as particle bounce have not been solved. Here, we improved its biological collection efficiencies by plating a mineral oil layer (100 µL) onto the agar plate. An Andersen six-stage sampler and a BioStage impactor were tested with mineral-oil-spread agar plates in collecting indoor and outdoor bacterial and fungal aerosols. The effects of sampling times (5, 10 and 20 min) were also studied using the BioStage impactor when sampling environmental bioaerosols as well as aerosolized Bacillus subtilis (G+) and Escherichia coli (G-). In addition, particle bounce reduction by mineral-oil-plate was also investigated using an optical particle counter (OPC). Experimental results revealed that use of mineral-oil-spread agar plate can substantially enhance culturable bioaerosol recoveries by Andersen type impactors (p-values<0.05). The recovery enhancement was shown to depend on bioaerosol size, type, sampling time and environment. In general, more enhancements (extra 20%) were observed for last stage of the Andersen six-stage samplers compared to the BioStage impactor for 10 min sampling. When sampling aerosolized B. subtilis, E. coli and environmental aerosols, the enhancement was shown to increase with increasing sampling time, ranging from 50% increase at 5 min to ∼100% at 20 min. OPC results indicated that use of mineral oil can effectively reduce the particle bounce with an average of 66% for 10 min sampling. Our work suggests that enhancements for fungal aerosols were primarily attributed to the reduced impaction stress, while for bacterial aerosols reduced impaction, desiccation and particle bounce played major roles. The developed technology can readily enhance the agar-based techniques including those high

  16. Enhancing bioaerosol sampling by Andersen impactors using mineral-oil-spread agar plate.

    PubMed

    Xu, Zhenqiang; Wei, Kai; Wu, Yan; Shen, Fangxia; Chen, Qi; Li, Mingzhen; Yao, Maosheng

    2013-01-01

    As a bioaerosol sampling standard, Andersen type impactor is widely used since its invention in 1950s, including the investigation of the anthrax attacks in the United States in 2001. However, its related problems such as impaction and desiccation stress as well as particle bounce have not been solved. Here, we improved its biological collection efficiencies by plating a mineral oil layer (100 µL) onto the agar plate. An Andersen six-stage sampler and a BioStage impactor were tested with mineral-oil-spread agar plates in collecting indoor and outdoor bacterial and fungal aerosols. The effects of sampling times (5, 10 and 20 min) were also studied using the BioStage impactor when sampling environmental bioaerosols as well as aerosolized Bacillus subtilis (G+) and Escherichia coli (G-). In addition, particle bounce reduction by mineral-oil-plate was also investigated using an optical particle counter (OPC). Experimental results revealed that use of mineral-oil-spread agar plate can substantially enhance culturable bioaerosol recoveries by Andersen type impactors (p-values<0.05). The recovery enhancement was shown to depend on bioaerosol size, type, sampling time and environment. In general, more enhancements (extra 20%) were observed for last stage of the Andersen six-stage samplers compared to the BioStage impactor for 10 min sampling. When sampling aerosolized B. subtilis, E. coli and environmental aerosols, the enhancement was shown to increase with increasing sampling time, ranging from 50% increase at 5 min to ∼100% at 20 min. OPC results indicated that use of mineral oil can effectively reduce the particle bounce with an average of 66% for 10 min sampling. Our work suggests that enhancements for fungal aerosols were primarily attributed to the reduced impaction stress, while for bacterial aerosols reduced impaction, desiccation and particle bounce played major roles. The developed technology can readily enhance the agar-based techniques including those high

  17. Classification of Low Velocity Impactors Using Spiral Sensing of Acousto-Ultrasonic Waves

    NASA Astrophysics Data System (ADS)

    Agbasi, Chijioke Raphael

    The non-linear elastodynamics of a flat plate subjected to low velocity foreign body impacts is studied, resembling the space debris impacts on the space structure. The work is based on a central hypothesis that in addition to identifying the impact locations, the material properties of the foreign objects can also be classified using acousto-ultrasonic signals (AUS). Simultaneous localization of impact point and classification of impact object is quite challenging using existing state-of-the-art structural health monitoring (SHM) approaches. Available techniques seek to report the exact location of impact on the structure, however, the reported information is likely to have errors from nonlinearity and variability in the AUS signals due to materials, geometry, boundary conditions, wave dispersion, environmental conditions, sensor and hardware calibration etc. It is found that the frequency and speed of the guided wave generated in the plate can be quantized based on the impactor's relationship with the plate (i.e. the wave speed and the impactor's mechanical properties are coupled). In this work, in order to characterize the impact location and mechanical properties of imapctors, nonlinear transient phenomenon is empirically studied to decouple the understanding using the dominant frequency band (DFB) and Lag Index (LI) of the acousto-ultrasonic signals. Next the understanding was correlated with the elastic modulus of the impactor to predict transmitted force histories. The proposed method presented in this thesis is especially applicable for SHM where sensors cannot be widely or randomly distributed. Thus a strategic organization and localization of the sensors is achieved by implementing the geometric configuration of Theodorous Spiral Sensor Cluster (TSSC). The performance of TSSC in characterizing the impactor types are compared with other conventional sensor clusters (e.g. square, circular, random etc.) and it is shown that the TSSC is advantageous over

  18. Volumetric Collection Efficiency and Droplet Sizing Accuracy of Rotary Impactors

    USDA-ARS?s Scientific Manuscript database

    Measurements of spray volume and droplet size are critical to evaluating the movement and transport of applied sprays associated with both crop production and protection practices and vector control applications for public health. Any sampling device used for this purpose will have an efficiency of...

  19. Mission Opportunities for the Flight Validation of the Kinetic Impactor Concept for Asteroid Deflection

    NASA Technical Reports Server (NTRS)

    Hernandez, Sonia; Barbee, Brent W.; Bhaskaran, Shyam; Getzandanner, Kenneth

    2013-01-01

    The kinetic impactor technique for deflecting near-Earth objects (NEOs), whereby a spacecraft is directed to collide with a NEO to alter its orbit via momentum transfer, is one of several proposed methods for defendingEarth against hazardous NEOs (asteroids and comets). In this paper we present detailed mission design concepts for a notionally feasible and aff ordable kinetic impactor flight validation mission deployed to a currently known near-Earth asteroid (NEA). Several filter steps are devised that utilize relevant criteria to optimally balance keyparameters, such as approach phase angle, estimated NEA diameter, relative velocity at intercept, and current NEA orbit knowledge, and produce refined lists of the most promising candidate target NEAs.

  20. Contaminant interferences with SIMS analyses of microparticle impactor residues on LDEF surfaces

    NASA Astrophysics Data System (ADS)

    Simon, C. G.; Batchelor, D.; Griffis, D. P.; Hunter, J. L.; Misra, V.; Ricks, D. A.; Wortman, J. J.

    1993-08-01

    Elemental analyses of impactor residues on high purity surfaces exposed to the LEO environment for 5.8 years on LDEF has revealed several probable sources for microparticles at this altitude, including natural micrometeorites and manmade debris ranging from paint pigments to bits of stainless steel. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences included pre-, post- and in-flight deposited particulate surface contaminants, as well as indigenous heterogeneous material contaminants. Non-flight contaminants traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with LDEF location and proximity to active electrical fields. In-flight deposited (low velocity) contaminants included urine droplets and bits of metal film from eroded thermal blankets.

  1. Contaminant Interferences with SIMS Analyses of Microparticle Impactor Residues on LDEF Surfaces

    NASA Technical Reports Server (NTRS)

    Simon, C. G.; Batchelor, D.; Griffis, D. P.; Hunter, J. L.; Misra, V.; Ricks, D. A.; Wortman, J. J.

    1992-01-01

    Elemental analyses of impactor residues on high purity surface exposed to the low earth orbit (LEO) environment for 5.8 years on Long Duration Exposure Facility (LDEF) has revealed several probable sources for microparticles at this altitude, including natural micrometeorites and manmade debris ranging from paint pigments to bits of stainless steel. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences included pre-, post-, and in-flight deposited particulate surface contaminants, as well as indigenous heterogeneous material contaminants. Non-flight contaminants traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF and proximity to active electrical fields. In-flight deposited (low velocity) contaminants included urine droplets and bits of metal film from eroded thermal blankets.

  2. The Small Carry-on Impactor (SCI) and the Hayabusa2 Impact Experiment

    NASA Astrophysics Data System (ADS)

    Saiki, T.; Imamura, H.; Arakawa, M.; Wada, K.; Takagi, Y.; Hayakawa, M.; Shirai, K.; Yano, H.; Okamoto, C.

    2017-07-01

    Hayabusa2 is a sample return mission of JAXA launched on 3 December 2014. Hayabusa2 is the successor of Hayabusa, which returned samples from the asteroid Itokawa to the Earth. Although the design of Hayabusa2 follows that of Hayabusa, the former is equipped with some new components. The small carry-on impactor (SCI) is one of those components. The SCI is a compact kinetic impactor designed to remove the asteroid surface regolith locally and create an artificial crater. One of the most important scientific objectives of Hayabusa2 is to investigate the chemical and physical properties of the internal materials and structures of the target body, asteroid Ryugu. Hayabusa2 will attempt to observe the resultant crater with some scientific instruments and to get samples from around the crater. High kinetic energy is required to create a meaningful crater, however, the impact system design needs to fit within strict constraints. Complicated functions, such as a guidance and control system, are not permitted. A special type of shaped charge is used for the acceleration of the impactor of the SCI in order to make system simpler. Using this explosion technique makes it possible to accelerate the impactor very quickly and to hit the asteroid without a guidance system. However, the impact operation will be complicated because the explosive is very powerful and it scatters high-speed debris at the detonation. This paper describes an overview of the SCI system, the results of the development testing and an outline of the impact experiment of the Hayabusa2 mission.

  3. The Small Carry-on Impactor (SCI) and the Hayabusa2 Impact Experiment

    NASA Astrophysics Data System (ADS)

    Saiki, T.; Imamura, H.; Arakawa, M.; Wada, K.; Takagi, Y.; Hayakawa, M.; Shirai, K.; Yano, H.; Okamoto, C.

    2016-10-01

    Hayabusa2 is a sample return mission of JAXA launched on 3 December 2014. Hayabusa2 is the successor of Hayabusa, which returned samples from the asteroid Itokawa to the Earth. Although the design of Hayabusa2 follows that of Hayabusa, the former is equipped with some new components. The small carry-on impactor (SCI) is one of those components. The SCI is a compact kinetic impactor designed to remove the asteroid surface regolith locally and create an artificial crater. One of the most important scientific objectives of Hayabusa2 is to investigate the chemical and physical properties of the internal materials and structures of the target body, asteroid Ryugu. Hayabusa2 will attempt to observe the resultant crater with some scientific instruments and to get samples from around the crater. High kinetic energy is required to create a meaningful crater, however, the impact system design needs to fit within strict constraints. Complicated functions, such as a guidance and control system, are not permitted. A special type of shaped charge is used for the acceleration of the impactor of the SCI in order to make system simpler. Using this explosion technique makes it possible to accelerate the impactor very quickly and to hit the asteroid without a guidance system. However, the impact operation will be complicated because the explosive is very powerful and it scatters high-speed debris at the detonation. This paper describes an overview of the SCI system, the results of the development testing and an outline of the impact experiment of the Hayabusa2 mission.

  4. Spherule layers, crater scaling laws, and the population of ancient terrestrial impactors

    NASA Astrophysics Data System (ADS)

    Johnson, Brandon C.; Collins, Gareth S.; Minton, David A.; Bowling, Timothy J.; Simonson, Bruce M.; Zuber, Maria T.

    2016-06-01

    Ancient layers of impact spherules provide a record of Earth's early bombardment history. Here, we compare different bombardment histories to the spherule layer record and show that 3.2-3.5 Ga the flux of large impactors (10-100 km in diameter) was likely 20-40 times higher than today. The E-belt model of early Solar System dynamics suggests that an increased impactor flux during the Archean is the result of the destabilization of an inward extension of the main asteroid belt (Bottke et al., 2012). Here, we find that the nominal flux predicted by the E-belt model is 7-19 times too low to explain the spherule layer record. Moreover, rather than making most lunar basins younger than 4.1 Gyr old, the nominal E-belt model, coupled with a corrected crater diameter scaling law, only produces two lunar basins larger than 300 km in diameter. We also show that the spherule layer record when coupled with the lunar cratering record and careful consideration of crater scaling laws can constrain the size distribution of ancient terrestrial impactors. The preferred population is main-belt-like up to ∼50 km in diameter transitioning to a steep distribution going to larger sizes.

  5. Investigating target versus impactor influences on Martian crater morphology at the simple-complex transition

    NASA Astrophysics Data System (ADS)

    Herrick, Robert R.; Hynek, Brian M.

    2017-08-01

    Comparing craters of identical diameter on a planet is an empirical method of studying the effects of different target and impactor properties while holding total impact energy nearly constant. We have analyzed the Martian crater population within a narrow diameter range (7 km < crater diameter < 9 km) at the simple-complex crater transition using three approaches. We looked for correlations of morphology with surface geology using a global crater database and global geologic map. We examined selected regions in detail with high-resolution images to further understand the relationship between crater morphology and bulk target properties. Finally, we examined craters in close proximity to each other in order to hold target properties constant, so that we could isolate impactor effects on crater morphology. We found a strong correlation between target properties and interior crater morphology, and we found little evidence that impactor properties (other than impact angle) affect crater appearance. Central uplift and wall slumping are enhanced for less consolidated targets. Layered targets affected both the excavation and modification stages of complex crater formation; the resulting craters have pseudoterraces, flat floors, and central pits.

  6. Simulation on a novel micron-array inertial impactor for submicron and ultrafine particle separation

    NASA Astrophysics Data System (ADS)

    Liu, Rui-Tao; Tao, Lu-Qi; Yang, Yi; Ren, Tian-Ling

    2016-08-01

    The particulate matter (PM), which was put forward in 1997 by US, had taken more and more attention due to the influence on human health. Although the mass concentration, number concentration and chemical composition of PM were still major research directions, how to collect these PMs more efficiently becomes critical. Inertial impactor is an effective separation device, however, due to different motion states of PM2.5 and PM0.3 in the flow field, the inertial impactor which can separate PM0.3 from other PMs has not been fabricated. In this work, the motion states for both submicron and ultrafine particles were studied by using classical theory of channel aerodynamic, and a novel micron-array inertial impactor was designed and simulated for the first time. Besides, the influence of some characteristic parameters (W, T, S, Dc, etc.) on particle collection efficiency were researched and discussed through simulation results. This novel structure can be easily fabricated by MEMS technology or laser direct writing and also can be widely used in particle separation or flexible sensor fields.

  7. A new cascade impactor for aerosol sampling with subsequent PIXE analysis

    NASA Astrophysics Data System (ADS)

    Maenhaut, W.; Hillamo, R.; Mäkelä, T.; Jaffrezo, J.-L.; Bergin, M. H.; Davidson, C. I.

    1996-04-01

    A small deposit area low pressure impactor (abbreviated to SDI) has been developed and tested. The device has been designed specifically to collect size-fractionated aerosol samples in remote locations for subsequent chemical analysis by PIXE. The SDI is a 12-stage, multinozzle device, but the deposit for each stage remains confined to an area with diameter less than 8 mm. It operates at a flow rate of 11 L/min and accepts the same, 25 mm diameter substrate rings as the PIXE International cascade impactor. The experimental cut-points for stages 12 through 1 are 8.50, 4.08, 2.68, 1.66, 1.06, 0.796, 0.591, 0.343, 0.231, 0.153, 0.086 and 0.045 μm equivalent aerodynamic diameter. The SDI has been tested in (and employed for) size-fractionated aerosol sampling in the Finnish Arctic and at Summit in Greenland. The data show that the SDI gives results very similar to those obtained with the PIXE International impactor, but with detection limits that are much lower. This suggests that the SDI can be used with shorter sampling times or in areas where concentrations are smaller to obtain reliable size distribution data. The results also suggest that data for a greater number of elements can be obtained with the SDI.

  8. Fabrication Process for Machined and Shrink-Fitted Impactor-Type Liners for the LOS Alamos Hedp Program

    NASA Astrophysics Data System (ADS)

    Randolph, B.

    2004-11-01

    Composite liners have been fabricated for the Los Alamos liner-driven High Energy Density Physics (HEDP) experiments using impactors formed by physical vapor deposition, and by machining and shrink fitting. Chemical vapor deposition has been proposed for some ATLAS liner applications. This paper describes the processes used to fabricate machined and shrink-fitted impactors; these processes have been used for copper impactors in 1100 aluminum liners and for 6061 T-6 aluminum impactors in 1100 aluminum liners. The most successful processes have been largely empirically developed and rely upon a combination of shrink-fitting and light press fitting. The processes used to date will be described along with some considerations for future composite liners for the HEDP Program.

  9. Characterization of the Lunar Plume Excavated by the LCROSS Impactor

    NASA Astrophysics Data System (ADS)

    Miller, C.; Chanover, N.; Suggs, R.; McMillan, R. J.; Hamilton, R. T.

    2009-12-01

    The impact of the 2000 kg LCROSS Centaur Earth Departure Upper Stage (EDUS) at the lunar south pole provides a unique opportunity to study plume dynamics following the impact of a body of known mass, composition, impact velocity, and entry angle. In February 2009, Universities Space Research Association (USRA) selected the Apache Point Observatory (APO) in Sunspot, NM as one of four NASA-funded ground-based LCROSS observation sites. The goal of the APO observation team is to image the LCROSS plume to measure the radius and velocity of the expanding plume boundary and determine the mass of the ejecta that is thrown up into sunlight by the EDUS impact. These mass measurements will in turn be used to calculate the expected water vapor optical depth as a function of time for a given estimate of water vapor content in the regolith. They will also allow a calibration of models used to estimate mass ejection by random meteorite impacts on the Moon, which have been observed and monitored by the Meteoroid Environment Office at NASA’s Marshall Space Flight Center. We will observe the impact on 09 October 2009 with three cameras simultaneously covering visible and near infrared wavelengths (from 0.6 to 1.7 microns). At APO, we will use the Astrophysical Research Consortium 3.5-meter telescope coupled with the Agile visible light frame transfer CCD camera, which is capable taking a continuous series of 0.3 second images with zero latency between exposures. Also at APO, we will use New Mexico State University’s 1 meter telescope with a StellaCam visible light video camera, which is capable of exposure times as short as 1/12,000 second sampled at a video rate of 1/30 second. Finally, we will image the plume in near infrared wavelengths (0.9 to 1.7 micron) with the 0.6-meter f/40 telescope at Tortugas Mountain in Las Cruces, NM using a Goodrich Sensors Unlimited InGaAs IR video camera. This camera is a similar design to that of the two near infrared cameras (NIR1 and NIR2) on

  10. Characterization of the dominant impactor signature for Apollo 17 impact melt rocks

    NASA Astrophysics Data System (ADS)

    Sharp, Miriam; Gerasimenko, Iva; Loudin, Lorne C.; Liu, Jingao; James, Odette B.; Puchtel, Igor S.; Walker, Richard J.

    2014-04-01

    Concentrations of the highly siderophile elements (HSE) Re, Os, Ir, Ru, Pt, and Pd and 187Os/188Os isotopic compositions are reported for seven Apollo 17 impact melt rocks. These data are used to examine the dominant chemical signature of the impactor that formed the melts. Six of the samples (72355, 72435, 72535, 76035, 76055, and 76135) have poikilitic textures; one sample (73235) has an aphanitic texture. Data for the samples define linear correlations when Ir is plotted versus other HSE concentrations, with y-intercepts indistinguishable from zero for most HSE in most rocks. Scatter about some of the trends, and occasional trends with positive y-intercepts, indicate either mixing of additional components that are heterogeneously distributed within several rocks, or modest fractionation of some HSE by volatilization, crystal fractionation, or other processes, during formation and evolution of the melt sheet. There is no statistical difference between the aphanitic and poikilitic samples in terms of HSE ratios after visible granulitic clasts were removed from aphanite 73235. Hence, earlier speculations that the two types of impact melt rocks at this site may have been generated by different impactors are not supported by our data. Most Apollo 17 samples examined here and in prior studies are characterized by very similar HSE signatures, consistent with a common impactor. These samples are characterized by elevated Ru/Ir, Pd/Ir, and Re/Os, relative to most chondrites. Collectively, the data indicate that the impactor was characterized by the following HSE ratios (2σ): Re/Ir 0.093 ± 0.020, Os/Ir 1.03 ± 0.28, Ru/Ir 1.87 ± 0.30, Pt/Ir 2.36 ± 0.31, Pd/Ir 1.85 ± 0.41, and present-day 187Os/188Os of 0.1322 ± 0.0013. The results most likely mean that the impactor was a body with a bulk composition that was just outside the range of meteoritic compositions currently sampled on Earth.

  11. Analysis of cascade impactor and EPA method 29 data from the americium/curium pilot melter system

    SciTech Connect

    Zamecnik, J.R.

    1997-11-01

    The offgas system of the Am/Cm pilot melter at TNX was characterized by measuring the particulate evolution using a cascade impactor and EPA Method 29. This sampling work was performed by John Harden of the Clemson Environmental Technologies Laboratory, under SCUREF Task SC0056. Elemental analyses were performed by the SRTC Mobile Laboratory.Operation of the Am/Cm melter with B2000 frit has resulted in deposition of PbO and boron compounds in the offgas system that has contributed to pluggage of the High Efficiency Mist Eliminator (HEME). Sampling of the offgas system was performed to quantify the amount of particulate in the offgas system under several sets of conditions. Particulate concentration and particle size distribution were measured just downstream of the melter pressure control air addition port and at the HEME inlet. At both locations, the particulate was measured with and without steam to the film cooler while the melter was idled at about 1450 degrees Celsius. Additional determinations were made at the melter location during feeding and during idling at 1150 degrees Celsius rather than 1450 degrees Celsius (both with no steam to the film cooler). Deposition of particulates upstream of the melter sample point may have, and most likely did occur in each run, so the particulate concentrations measured do no necessarily reflect the total particulate emission at the melt surface. However, the data may be used in a relative sense to judge the system performance.

  12. Design and testing of a controlled electromagnetic spinal cord impactor for use in large animal models of acute traumatic spinal cord injury.

    PubMed

    Petteys, Rory J; Spitz, Steven M; Syed, Hasan; Rice, R Andrew; Sarabia-Estrada, Rachel; Goodwin, C Rory; Sciubba, Daniel M; Freedman, Brett A

    2017-09-01

    Spinal cord injury (SCI) causes debilitating neurological dysfunction and has been observed in warfighters injured in IED blasts. Clinical benefit of SCI treatment remains elusive and better large animal models are needed to assess treatment options. Here, we describe a controlled electromagnetic spinal cord impactor for use in large animal models of SCI. A custom spinal cord impactor and platform were fabricated for large animals (e.g., pig, sheep, dog, etc.). Impacts were generated by a voice coil actuator; force and displacement were measured with a load cell and potentiometer respectively. Labview (National Instruments, Austin, TX) software was used to control the impact cycle and import force and displacement data. Software finite impulse response (FIR) filtering was employed for all input data. Silicon tubing was used a surrogate for spinal cord in order to test the device; repeated impacts were performed at 15, 25, and 40 Newtons. Repeated impacts demonstrated predictable results at each target force. The average duration of impact was 71.2 ±6.1ms. At a target force of 40N, the output force was 41.5 ±0.7N. With a target of 25N, the output force was 23.5 ±0.6N; a target of 15Newtons revealed an output force of 15.2 ±1.4N. The calculated acceleration range was 12.5-21.2m/s(2). This custom spinal cord impactor reliably delivers precise impacts to the spinal cord and will be utilized in future research to study acute traumatic SCI in a large animal. Published by Elsevier Ltd.

  13. Development of infrared photothermal deflection spectroscopy (mirage effect) for analysis of condensed-phase aerosols collected in a micro-orifice uniform deposit impactor.

    PubMed

    Dada, Oluwatosin O; Bialkowski, Stephen E

    2008-12-01

    The potential of mid-infrared photothermal deflection spectrometry for aerosol analysis is demonstrated. Ammonium nitrate aerosols are deposited on a flat substrate using a micro-orifice uniform deposit impactor (MOUDI). Photothermal spectroscopy with optical beam deflection (mirage effect) is used to detect deposited aerosols. Photothermal deflection from aerosols is measured by using pulsed infrared laser light to heat up aerosols collected on the substrate. The deflection signal is obtained by measuring the position of a spot from a beam of light as it passes near the heated surface. The results indicate non-rotating impaction as the preferred MOUDI impaction method. Energy-dependent photothermal measurement shows a linear relationship between signal and laser intensity, and no loss of signal with time is observed. The detection limit from the signal-mass curve is 7.31 ng. For 30 minutes collection time and 30 L/min flow rate of the impactor, the limit of detection in terms of aerosol mass concentration is 0.65 microg m(-3).

  14. Analysis of ejecta fate from proposed man-made impactors into near-Earth objects --- a NEOShield study

    NASA Astrophysics Data System (ADS)

    Schwartz, S.; Michel, P.; Jutzi, M.

    2014-07-01

    Asteroids measuring 100 meters across tend to impact the Earth once every 5,000 years on average [1]. Smaller bodies enter into the Earth's atmosphere more frequently, but may detonate before reaching the surface. Conversely, impacts from larger bodies are more rare [2], but can come with devastating global consequences to living species. In 2005, a United States Congressional mandate called for NASA to detect, by 2020, 90 percent of near-Earth objects (NEOs) having diameters of 140 meters or greater [3]. One year prior, ESA's Near-Earth Object Mission Advisory Panel (NEOMAP) recommended the study of a kinetic impactor mission as a priority in the framework of NEO risk assessment [4]. A ''Phase-A'' study of such a mission, Don Quixote, took place at ESA until 2007. In accordance with NEOMAP and with the Target NEO Global Community's recommendations in 2011 [5], the NEOShield Project is being funded for 3.5 years by the European Commission in its FP7 program. NEOShield began in 2012 and is primarily, but not exclusively, a European consortium of research institutions and engineering industries that aims to analyze promising mitigation options and provide solutions to the critical scientific and technical obstacles involved in confronting threats posed by the small bodies in the neighborhood of the Earth's orbit [6]. To further explore the NEO threat mitigation via the strategy of kinetic impact, building upon the Don Quixote study, the idea is to target a specific NEO for impact and attempt to quantify the response. How long do ejecta remain aloft and where do they end up? Fragments that are ejected at high speeds escape, but what about material moving at or near the escape speed of the NEO or that suffer energy-dissipating collisions after being ejected? Where would be a ''safe'' location for an observing spacecraft during and subsequent to the impact? Here, we outline the early phases of an ongoing numerical investigation of the fate of the material ejected from a

  15. Ice Nuclei in Mid-Latitude Cirrus: Preliminary Results from a New Counterflow Virtual Impactor (CVI) Aircraft Inlet

    NASA Astrophysics Data System (ADS)

    Froyd, K. D.; Cziczo, D. J.; Murphy, D. M.; Kulkarni, G.; Lawson, P.

    2011-12-01

    Cirrus cloud properties are strongly governed by the mechanism of ice particle formation and by the number and effectiveness of ambient ice nuclei. Airborne measurements of ice nuclei reveal new nucleation mechanisms, provide constraints on microphysical models, and guide laboratory investigations. For over two decades the Counterflow Virtual Impactor (CVI) inlet has remained the prevailing approach for sampling cloud particles to measure ice nuclei from an aircraft platform. However, traditional CVI inlets have fundamental limitations when operating on high speed aircraft, where only a small fraction of ambient cloud particles are typically sampled. A novel 'folded' CVI was constructed and deployed during the NASA MACPEX 2011 campaign. The flow design of this inlet effectively doubles the CVI length and thereby increases the size range of captured cirrus particles. Additional design elements such as an internal vortex flow, a neon carrier gas, and an infrared laser further improve the capture and evaporation of ice crystals. Preliminary results of ice nuclei composition measured by the PALMS single-particle mass spectrometer are presented from the MACPEX campaign. Examples of ice nuclei from mid-latitude cirrus are shown, including mineral dust, organic-rich aerosol with amine and diacid components, and lead-containing aerosol.

  16. Physical and optical properties of the Pinatubo volcanic aerosol: Aircraft observations with impactors and a Sun-tracking photometer

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Russell, P. B.; Allen, D. A.; Ferry, G. V.; Snetsinger, K. G.; Livingston, J. M.; Verma, S.

    1994-01-01

    As determined in situ by impactor samplers flown on an ER-2 at 16.5- to 20.7-km pressure altitude and on a DC-8 at 9.5- to 12.6-km pressure altitudes, the 1991 Pinatubo volcanic eruption increased the particle surface area of stratospheric aerosols up to 50-fold and the particle volume up to 2 orders of magnitude. Particle composition was typical of a sulfuric acid-water mixture at ER-2 altitudes. Ash particles coated with sulfuric acid comprised a significant fraction of aerosol at DC-8 altitudes. Mie-computed light extinction increased up to 20-fold at midvisible and greater than 100-fold at near-IR wavelengths. The optical thickness measured through the aerosol layer by an autotracking Sun photometer aboard a DC-8 aircraft at 10.7- to 11.3-km pressure altitudes shows a spectral shape that is similar to the Mie-calculated spectral extinction at ER-2 altitudes. Surface area distributions calculated by inversion of spectral optical depth measurements show characteristics that are similar to the mean surface area distribution resulting from 35 in situ measurements.

  17. Nature of the impactor at the K/T boundary: clues from Os, W and Cr isotopes.

    NASA Astrophysics Data System (ADS)

    Quitté, G.; Robin, E.; Capmas, F.; Levasseur, S.; Rocchia, R.; Birck, J. L.; Allègre, C. J.

    2003-04-01

    We measured the isotope composition of Os, W and Cr in K/T boundary sediments of three marine sites (Stevns Klint, Caravaca and Bidart) to determine the nature of the bolid that impacted the Earth 65 Myrs ago. We also analysed Ni-rich cosmic spinels, because they are thought to keep the signature of the impactor. The low REE content in spinels precludes indeed the hypothesis of a mixing with more than 10% of terrestrial material. The Os and W enrichment at the K/T boundary could be explained by a scavenging of chalcophile elements at the time of sulfide precipitation. The 187Os/186Os ratio of the K/T sediments is higher than the ratio of any kind of meteorites. On top of a possible mixing with surrounding sediments, we suggest that the boundary contained more Re in the past (lost since that time by alteration and oxidation) and that the Os isotope ratio is in fact disturbed. On each of the three sites, the boundary itself does not present any tungsten isotopic anomaly. The most likely interpretation is that the extraterrestrial material is diluted enough into the sediments so that the isotopic signature has been erased. Spinels show a small deficit of (0.34±0.9) ɛ in 182W. The large error bar precludes any clear conclusion whether or not a meteoritic signature is really present. If the spinels really carry an extraterrestrial signature as expected, their W composition is in favour of an ordinary chondrite. All K/T samples (sediments and spinels) are apparently depleted in 53Cr by about 0.5 ɛ (after renormalization of 54Cr to the terrestrial value) whereas ordinary chondrites display an excess of about 0.5 ɛ. Among meteorites, only carbonaceous chondrites present a negative value for the 53Cr/52Cr ratio relative to the terrestrial value. As more than 90% of the Cr present in spinels is of extraterrestrial origin, the Cr isotopes unambiguously show that the K/T impactor was a carbonaceous chondrite. These isotopic results also confirm the extraterrestrial origin

  18. Physical and Chemical Characterization of Particles in the Upper Troposphere and Lower Stratosphere: Microanalysis of Aerosol Impactor Samples

    NASA Technical Reports Server (NTRS)

    Sheridan, Patrick J.

    1999-01-01

    Herein is reported activities to support the characterization of the aerosol in the upper troposphere (UT) and lower stratosphere (LS) collected during the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) missions in 1994. Through a companion proposal, another group was to measure the size distribution of aerosols in the 0.008 to 2 micrometer diameter range and to collect for us impactor samples of particles larger than about 0.02 gm. In the first year, we conducted laboratory studies related to particulate deposition patterns on our collection substrates, and have performed the analysis of many ASHOE/MAESA aerosol samples from 1994 using analytical electron microscopy (AEM). We have been building an "aerosol climatology" with these data that documents the types and relative abundances of particles observed at different latitudes and altitudes. The second year (and non-funded extension periods) saw continued analyses of impactor aerosol samples, including more ASHOE/MAESA samples, some northern hemisphere samples from the NASA Stratospheric Photochemistry Aerosols and Dynamics Expedition (SPADE) program for comparison, and a few aerosol samples from the NASA Stratospheric TRacers of Atmospheric Transport (STRAT) program. A high-resolution field emission microscope was used for the analysis and re-analysis of a number of samples to determine if this instrument was superior in performance to our conventional electron microscope. In addition, some basic laboratory studies were conducted to determine the minimum detectable and analyzable particle size for different types of aerosols. In all, 61 aerosol samples were analyzed, with a total of over 30,000 individual particle analyses. In all analyzed samples, sulfate particles comprised the major aerosol number fraction. It must be stressed that particles composed of more than one species, for example sulfate and organic carbon, were classified

  19. Diverse impactors in Apollo 15 and 16 impact melt rocks: Evidence from osmium isotopes and highly siderophile elements

    NASA Astrophysics Data System (ADS)

    Liu, Jingao; Sharp, Miriam; Ash, Richard D.; Kring, David A.; Walker, Richard J.

    2015-04-01

    Concentrations of highly siderophile elements (HSE) and 187Os/188Os isotopic compositions for eleven impact related rocks from the Apollo 15 and 16 landing sites are reported and combined with existing geochronological data to investigate the chemical nature and temporal changes in the large impactors implicated in the formation of the lunar basins. Data for the samples all define linear trends on plots of HSE versus Ir concentrations, whose slopes likely reflect the relative HSE compositions of the dominant impactors that formed the rocks. The inferred Imbrium basin impactor that generated Apollo 15 impact melt rocks 15445 and 15455 was characterized by modestly suprachondritic 187Os/188Os, Ru/Ir, Pt/Ir and Pd/Ir ratios. Diverse impactor components are revealed in the Apollo 16 impact melt rocks. The 187Os/188Os and HSE/Ir ratios of the impactor components in melt rocks 60635, 63595 and 68416, with reported ages <3.84 Ga, are within the range of chondritic meteorites, but slightly higher than ratios characterizing previously studied granulitic impactites with reported ages >4.0 Ga. By contrast, the impactor components in melt rocks 60235, 62295 and 67095, with reported ages of ∼3.9 Ga, are characterized by suprachondritic 187Os/188Os and HSE/Ir ratios similar to the Apollo 15 impact melt rocks, and may also sample the Imbrium impactor. Three lithic clasts from regolith breccias 60016 and 65095, also with ∼3.9 Ga ages, contain multiple impactor components, of which the dominant composition is considerably more suprachondritic than those implicated for Imbrium and Serenitatis (Apollo 17) impactors. The dominant composition recorded in these rocks was most likely inherited from a pre-Imbrium impactor. Consideration of composition versus age relations among lunar impact melt rocks reveals no discernable trend. Virtually all lunar impact melt rocks sampled by the Apollo missions, as well as meteorites, are characterized by 187Os/188Os and HSE/Ir ratios that, when

  20. Rebuttal to the comment by Malhotra and Strom on "Constraints on the source of lunar cataclysm impactors"

    NASA Astrophysics Data System (ADS)

    Ćuk, Matija; Gladman, Brett J.; Stewart, Sarah T.

    2011-11-01

    Ćuk et al. (Ćuk, M. Gladman, B.J., Stewart, S.T. [2010]. Icarus 207 590-594) concluded that the the lunar cataclysm (late heavy bombardment) was recorded in lunar Imbrian era craters, and that their size distribution is different from that of main belt asteroids (which may have been the dominant pre-Imbrian impactors). This result would likely preclude the asteroid belt as the direct source of lunar cataclysm impactors. Malhotra and Strom (Malhotra, R., Strom, R.G. [2011]. Icarus) maintain that the lunar impactor population in the Imbrian era was the same as in Nectarian and pre-Nectarian periods, and this population had a size distribution identical to that of main belt asteroids. In support of this claim, they present an Imbrian size distribution made from two data sets published by Wilhelms et al. (Wilhelms, D.E., Oberbeck, V.R., Aggarwal, H.R. [1978]. Proc. Lunar Sci. Conf. 9, 3735-3762). However, these two data sets cannot be simply combined as they represent areas of different ages and therefore crater densities. Malhotra and Strom (Malhotra, R., Strom, R.G. [2011]. Icarus) differ with the main conclusion of Wilhelms et al. (Wilhelms, D.E., Oberbeck, V.R., Aggarwal, H.R. [1978]. Proc. Lunar Sci. Conf. 9, 3735-3762) that the Nectarian and Imbrian crater size distributions were different. We conclude that the available data indicate that the lunar Imbrian-era impactors had a different size distribution from the older ones, with the Imbrian impactor distribution being significantly richer in small impactors than that of older lunar impactors or current main-belt asteroids.

  1. A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors.

    PubMed

    Brown, P G; Assink, J D; Astiz, L; Blaauw, R; Boslough, M B; Borovička, J; Brachet, N; Brown, D; Campbell-Brown, M; Ceranna, L; Cooke, W; de Groot-Hedlin, C; Drob, D P; Edwards, W; Evers, L G; Garces, M; Gill, J; Hedlin, M; Kingery, A; Laske, G; Le Pichon, A; Mialle, P; Moser, D E; Saffer, A; Silber, E; Smets, P; Spalding, R E; Spurný, P; Tagliaferri, E; Uren, D; Weryk, R J; Whitaker, R; Krzeminski, Z

    2013-11-14

    Most large (over a kilometre in diameter) near-Earth asteroids are now known, but recognition that airbursts (or fireballs resulting from nuclear-weapon-sized detonations of meteoroids in the atmosphere) have the potential to do greater damage than previously thought has shifted an increasing portion of the residual impact risk (the risk of impact from an unknown object) to smaller objects. Above the threshold size of impactor at which the atmosphere absorbs sufficient energy to prevent a ground impact, most of the damage is thought to be caused by the airburst shock wave, but owing to lack of observations this is uncertain. Here we report an analysis of the damage from the airburst of an asteroid about 19 metres (17 to 20 metres) in diameter southeast of Chelyabinsk, Russia, on 15 February 2013, estimated to have an energy equivalent of approximately 500 (±100) kilotons of trinitrotoluene (TNT, where 1 kiloton of TNT = 4.185×10(12) joules). We show that a widely referenced technique of estimating airburst damage does not reproduce the observations, and that the mathematical relations based on the effects of nuclear weapons--almost always used with this technique--overestimate blast damage. This suggests that earlier damage estimates near the threshold impactor size are too high. We performed a global survey of airbursts of a kiloton or more (including Chelyabinsk), and find that the number of impactors with diameters of tens of metres may be an order of magnitude higher than estimates based on other techniques. This suggests a non-equilibrium (if the population were in a long-term collisional steady state the size-frequency distribution would either follow a single power law or there must be a size-dependent bias in other surveys) in the near-Earth asteroid population for objects 10 to 50 metres in diameter, and shifts more of the residual impact risk to these sizes.

  2. A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors

    NASA Astrophysics Data System (ADS)

    Brown, P. G.; Assink, J. D.; Astiz, L.; Blaauw, R.; Boslough, M. B.; Borovička, J.; Brachet, N.; Brown, D.; Campbell-Brown, M.; Ceranna, L.; Cooke, W.; de Groot-Hedlin, C.; Drob, D. P.; Edwards, W.; Evers, L. G.; Garces, M.; Gill, J.; Hedlin, M.; Kingery, A.; Laske, G.; Le Pichon, A.; Mialle, P.; Moser, D. E.; Saffer, A.; Silber, E.; Smets, P.; Spalding, R. E.; Spurný, P.; Tagliaferri, E.; Uren, D.; Weryk, R. J.; Whitaker, R.; Krzeminski, Z.

    2013-11-01

    Most large (over a kilometre in diameter) near-Earth asteroids are now known, but recognition that airbursts (or fireballs resulting from nuclear-weapon-sized detonations of meteoroids in the atmosphere) have the potential to do greater damage than previously thought has shifted an increasing portion of the residual impact risk (the risk of impact from an unknown object) to smaller objects. Above the threshold size of impactor at which the atmosphere absorbs sufficient energy to prevent a ground impact, most of the damage is thought to be caused by the airburst shock wave, but owing to lack of observations this is uncertain. Here we report an analysis of the damage from the airburst of an asteroid about 19 metres (17 to 20 metres) in diameter southeast of Chelyabinsk, Russia, on 15 February 2013, estimated to have an energy equivalent of approximately 500 (+/-100) kilotons of trinitrotoluene (TNT, where 1 kiloton of TNT = 4.185×1012 joules). We show that a widely referenced technique of estimating airburst damage does not reproduce the observations, and that the mathematical relations based on the effects of nuclear weapons--almost always used with this technique--overestimate blast damage. This suggests that earlier damage estimates near the threshold impactor size are too high. We performed a global survey of airbursts of a kiloton or more (including Chelyabinsk), and find that the number of impactors with diameters of tens of metres may be an order of magnitude higher than estimates based on other techniques. This suggests a non-equilibrium (if the population were in a long-term collisional steady state the size-frequency distribution would either follow a single power law or there must be a size-dependent bias in other surveys) in the near-Earth asteroid population for objects 10 to 50 metres in diameter, and shifts more of the residual impact risk to these sizes.

  3. A methodology to study impactor particle reentrainment and a proposed stage coating for the NGI.

    PubMed

    Rissler, Jenny; Asking, Lars; Dreyer, Jakob Kisbye

    2009-12-01

    Mass-weighted aerodynamic particle-size distribution (APSD) is a key attribute for pharmaceutical products developed to deliver drugs to or through the lungs. In development and quality control, APSD is primarily determined using multistage cascade impactors. For impactor techniques, particle reentrainment is critical because it may lead to an overestimation of the respirable fraction. To avoid reentrainment, the collection surfaces need to be coated with a suitable material. In this study a method was developed to test flow dependence of particle reentrainment in the Next Generation Pharmaceutical Impactor (NGI) at flow rates ranging from 20 to 80 L/min, and was used to test three coating materials: glycerol coating, aqueous coating with, and without soaked filter paper. Uncoated cups were also tested. In the experimental setup a Vilnius Aerosol Generator generated a flow-independent dry powder aerosol, consisting of micronized insulin. The glycerol coating was not well suited to reduce particle reentrainment at flows >or=40 L/min. The soaked filter paper coating was found to give nearly the same particle size distributions regardless of flow and was therefore judged to be the best of those tested. Using liquid only, without the filter paper, gave the same particle size distributions as soaked filter paper for flows or=60 L/min particle reentrainment increased with flow. However, for most applications liquid coating reduced particle reentrainment to an extent at which further reduction was irrelevant. Particle reentrainment was prevalent for uncoated cups at all flow rates tested. This study shows the advantage of using a stable and flow-independent aerosol generation method to examine particle reentrainment at various flows through the NGI. For insulin dry powder, the use of an aqueous solution as cup coating, preferably with a filter, reduced particle reentrainment to a minimum. The results were confirmed in a study with a DPI.

  4. Surveying the South Pole-Aitken basin magnetic anomaly for remnant impactor metallic iron

    USGS Publications Warehouse

    Cahill, Joshua T.S.; Hagerty, Justin J.; Lawrence, David M.; Klima, Rachel L.; Blewett, David T.

    2014-01-01

    The Moon has areas of magnetized crust ("magnetic anomalies"), the origins of which are poorly constrained. A magnetic anomaly near the northern rim of South Pole-Aitken (SPA) basin was recently postulated to originate from remnant metallic iron emplaced by the SPA basin-forming impactor. Here, we remotely examine the regolith of this SPA magnetic anomaly with a combination of Clementine and Lunar Prospector derived iron maps for any evidence of enhanced metallic iron content. We find that these data sets do not definitively detect the hypothesized remnant metallic iron within the upper tens of centimeters of the lunar regolith.

  5. Quantitative x-ray diffraction phase analysis of coarse airborne particulate collected by cascade impactor sampling

    NASA Astrophysics Data System (ADS)

    Esteve, V.; Rius, J.; Ochando, L. E.; Amigó, J. M.

    Mineralogical composition of Castellon (Spanish Mediterranean coast) atmospheric aerosol was studied by X-ray diffraction by sampling with a cascade impactor without filters. Quantitative phase analysis of natural phases present in the atmospheric coarse aerosol was performed using a modified version of the computer program MENGE, that uses the standardless X-ray method developed by Rius for the quantitative analysis of multiphase mixtures, adapted for PC running. Presence of quartz, calcite and gypsum was identified in the atmospheric aerosol and we have quantified their amounts using the standardless method.

  6. Experimental Evidence of Impact Ignition: 100-Fold Increase of Neutron Yield by Impactor Collision

    NASA Astrophysics Data System (ADS)

    Azechi, H.; Sakaiya, T.; Watari, T.; Karasik, M.; Saito, H.; Ohtani, K.; Takeda, K.; Hosoda, H.; Shiraga, H.; Nakai, M.; Shigemori, K.; Fujioka, S.; Murakami, M.; Nagatomo, H.; Johzaki, T.; Gardner, J.; Colombant, D. G.; Bates, J. W.; Velikovich, A. L.; Aglitskiy, Y.; Weaver, J.; Obenschain, S.; Eliezer, S.; Kodama, R.; Norimatsu, T.; Fujita, H.; Mima, K.; Kan, H.

    2009-06-01

    We performed integrated experiments on impact ignition, in which a portion of a deuterated polystyrene (CD) shell was accelerated to about 600km/s and was collided with precompressed CD fuel. The kinetic energy of the impactor was efficiently converted into thermal energy generating a temperature of about 1.6 keV. We achieved a two-order-of-magnitude increase in the neutron yield by optimizing the timing of the impact collision, demonstrating the high potential of impact ignition for fusion energy production.

  7. Experimental Evidence of Impact Ignition: 100-Fold Increase of Neutron Yield by Impactor Collision

    SciTech Connect

    Azechi, H.; Sakaiya, T.; Watari, T.; Saito, H.; Ohtani, K.; Takeda, K.; Hosoda, H.; Shiraga, H.; Nakai, M.; Shigemori, K.; Fujioka, S.; Murakami, M.; Nagatomo, H.; Johzaki, T.; Norimatsu, T.; Fujita, H.; Mima, K.; Karasik, M.; Gardner, J.; Colombant, D. G.

    2009-06-12

    We performed integrated experiments on impact ignition, in which a portion of a deuterated polystyrene (CD) shell was accelerated to about 600 km/s and was collided with precompressed CD fuel. The kinetic energy of the impactor was efficiently converted into thermal energy generating a temperature of about 1.6 keV. We achieved a two-order-of-magnitude increase in the neutron yield by optimizing the timing of the impact collision, demonstrating the high potential of impact ignition for fusion energy production.

  8. The Late Eocene Impactor Shower Was Likely Produced by the Breakup of a Mars-Crossing Asteroid

    NASA Astrophysics Data System (ADS)

    Bottke, W. F.; Morbidelli, A.; Nesvorny, D.

    2005-08-01

    The largest impacts on Earth since the K/T event both occurred in the Late Eocene: the Popigai crater in Siberia (D = 100 km; 35.7 ± 0.2 Ma) and the Chesapeake Bay crater off the eastern US seaboard (D = 40 km; 35.5± 0.6 Ma). At the same time, an unusually high flux of interplanetary dust particles was recorded by 3He measurements in well-dated marine sediments from the Indian/Atlantic Oceans. Farley et al. (1998) argued a comet shower produced these events. The impact melt at Popagai, however, was produced by an L-chondrite impactor (Tagle and Claeys 2004). Thus, the so-called Late Eocene event was likely produced by an ``asteroid shower". Note that asteroid showers were originally thought to be byproducts of main belt family-forming events, with the ejecta directly injected into nearby resonances (Zappala et al. 1998). A search by our team, however, indicates no known family can produce this event. We postulate here a related but alternative mechanism to produce asteroid showers. Most large terrestrial impactors (D > 5 km) escape the main belt onto Mars-crossing orbits via tiny resonances in the inner main belt. Here they reside until close encounters push them into a powerful resonance (usually the v6 secular resonance) that quickly takes them to an Earth-crossing orbit. At the same time, these objects continue to pass through the main belt, where they are ``sitting ducks" for main belt projectiles. Using collision evolution model results, we find a D > 5 km asteroid in the v6 resonance should disrupt once every 70 My. The fragments, which often have low inclination orbits and thus high collision probabilities with Earth, have an impact probability distribution that is spiky; ˜ 50% of those striking the Earth hit within 2 My. Finally, the dust produced by this event has a high likelihood of hitting Earth, consistent with the observed 3He spike.

  9. Response of laminated composite plates to low-speed impact by airgun-propelled and dropped-weight impactors

    NASA Technical Reports Server (NTRS)

    Prasad, Chunchu B.; Ambur, Damodar R.; Starnes, James H., Jr.

    1993-01-01

    An analytical procedure has been developed to determine the transient response of simply supported, rectangular laminated composite plates subjected to impact loads from airgun-propelled or dropped-weight impactors. A first-order shear-deformation theory has been included in the analysis to represent properly any local short-wavelength transient bending response. The impact force has been modeled as a locally distributed load with a cosine-cosine distribution. A double Fourier series expansion and the Timoshenko small increment method have been used to determine the contact force, out-of-plane deflections, and inplane strains and stresses at any plate location due to an impact force at any plate location. The results of experimental and analytical studies are compared for quasi-isotropic laminates. The results indicate the importance of including transverse shear deformation effects in the analysis for predicting the response of laminated plates subjected to both airgun-propelled and dropped-weight impactors. The results also indicate that plate boundary conditions influence the axial strains more significantly than the contact force for a dropped-weight impactor. The results of parametric studies identify a scaling approach based on impactor momentum that suggests an explanation for the differences in the responses of plates impacted by airgun-propelled or dropped-weight impactors.

  10. Cataclysm No More: New Views on the Timing and Delivery of Lunar Impactors

    NASA Astrophysics Data System (ADS)

    Zellner, Nicolle E. B.

    2017-09-01

    If properly interpreted, the impact record of the Moon, Earth's nearest neighbour, can be used to gain insights into how the Earth has been influenced by impacting events since its formation 4.5 billion years (Ga) ago. However, the nature and timing of the lunar impactors - and indeed the lunar impact record itself - are not well understood. Of particular interest are the ages of lunar impact basins and what they tell us about the proposed "lunar cataclysm" and/or the late heavy bombardment (LHB), and how this impact episode may have affected early life on Earth or other planets. Investigations of the lunar impactor population over time have been undertaken and include analyses of orbital data and images; lunar, terrestrial, and other planetary sample data; and dynamical modelling. Here, the existing information regarding the nature of the lunar impact record is reviewed and new interpretations are presented. Importantly, it is demonstrated that most evidence supports a prolonged lunar (and thus, terrestrial) bombardment from 4.2 to 3.4 Ga and not a cataclysmic spike at 3.9 Ga. Implications for the conditions required for the origin of life are addressed.

  11. Comparison of experimental and numerical studies of the performance characteristics of a pumped counterflow virtual impactor

    SciTech Connect

    Kulkarni, Gourihar R.; Pekour, Mikhail S.; Afchine, Armin; Murphy, Daniel M.; Cziczo, Daniel J.

    2011-01-03

    Experiments and Computational Fluid Dynamic (CFD) simulations were performed to evaluate the performance characteristics of a Pumped Counterflow Virtual Impactor (PCVI). Tests were conducted for various flow configurations for which the diameter at which 50% of the particles were transmitted was determined. Experimentally determined 50% cutpoints varied from 2.2 to 4.8 micrometers and CFD predicted diameters agreed within ± 0.4 microns. Both experimental and CFD results showed similar transmission efficiency (TE) curves. CFD TE was always greater than experimental results, most likely due to impaction losses in fittings not included in the simulations. Ideal transmission, corresponding to 100% TE, was never realized in either case due to impaction losses and small scale flow features such as eddies. Areas where CFD simulations showed such flow recirculation zones were also found to be the locations where particulate residue was deposited during experiments. CFD parametric tests showed that PCVI performance can be affected by the nozzle geometry and misalignment between the nozzle and collector orifice. We conclude that CFD can be used with confidence for counterflow virtual impactor (CVI) design. Modifications to improve the performance characteristics of the PCVI are suggested.

  12. LDEF impact craters formed by carbon-rich impactors: A preliminary report

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Dibrozolo, F. Radicati; Fleming, Ronald H.; Harris, David W.; Brownlee, Don; Reilly, Terrence W.

    1992-01-01

    Two impact craters found in Al from the Long Duration Exposure Facility (LDEF) experiment tray have residues concentrated in the bottoms, along the walls, and on top of overturned rims. Analyses indicate a 'chondritic' compositional signature (Si, S, Ca, Fe, Mg, and Ni) for the bulk residue. In one crater (number 74), round to irregular silicate grains are overlain by carbon. In addition, carbon also partially covers the crater walls, the top of the raised overturned rim, and extends outward from the crater. The second crater (number 31) also contains carbon with similar distribution in and about the crater, although the silicate residue appears to be glassy. Silver, I, K, and F (possibly some of the Ca, S, and Cl) appear to be contaminants as well as analyzed aromatic carbonaceous species associated with the raised rim and the area surrounding the crater. The origin of the impactors is assumed to be extraterrestrial. The existence of impactor residue in two craters implies impact velocities less than or equal to 6 km, based on experimental hypervelocity studies.

  13. Cataclysm No More: New Views on the Timing and Delivery of Lunar Impactors.

    PubMed

    Zellner, Nicolle E B

    2017-05-03

    If properly interpreted, the impact record of the Moon, Earth's nearest neighbour, can be used to gain insights into how the Earth has been influenced by impacting events since its formation ~4.5 billion years (Ga) ago. However, the nature and timing of the lunar impactors - and indeed the lunar impact record itself - are not well understood. Of particular interest are the ages of lunar impact basins and what they tell us about the proposed "lunar cataclysm" and/or the late heavy bombardment (LHB), and how this impact episode may have affected early life on Earth or other planets. Investigations of the lunar impactor population over time have been undertaken and include analyses of orbital data and images; lunar, terrestrial, and other planetary sample data; and dynamical modelling. Here, the existing information regarding the nature of the lunar impact record is reviewed and new interpretations are presented. Importantly, it is demonstrated that most evidence supports a prolonged lunar (and thus, terrestrial) bombardment from ~4.2 to 3.4 Ga and not a cataclysmic spike at ~3.9 Ga. Implications for the conditions required for the origin of life are addressed.

  14. Cataclysm No More: New Views on the Timing and Delivery of Lunar Impactors

    NASA Astrophysics Data System (ADS)

    Zellner, Nicolle E. B.

    2017-05-01

    If properly interpreted, the impact record of the Moon, Earth's nearest neighbour, can be used to gain insights into how the Earth has been influenced by impacting events since its formation 4.5 billion years (Ga) ago. However, the nature and timing of the lunar impactors - and indeed the lunar impact record itself - are not well understood. Of particular interest are the ages of lunar impact basins and what they tell us about the proposed "lunar cataclysm" and/or the late heavy bombardment (LHB), and how this impact episode may have affected early life on Earth or other planets. Investigations of the lunar impactor population over time have been undertaken and include analyses of orbital data and images; lunar, terrestrial, and other planetary sample data; and dynamical modelling. Here, the existing information regarding the nature of the lunar impact record is reviewed and new interpretations are presented. Importantly, it is demonstrated that most evidence supports a prolonged lunar (and thus, terrestrial) bombardment from 4.2 to 3.4 Ga and not a cataclysmic spike at 3.9 Ga. Implications for the conditions required for the origin of life are addressed.

  15. Size-dependent earth impactor warning times and corresponding campaign mission recommendations

    NASA Astrophysics Data System (ADS)

    Borzych, Todd A.

    2012-05-01

    NASA seeks to reliably detect potential Earth Impactors (EI) in time to defend the planet by deflecting them. Congress has given an unfunded mandate to NASA to lead Spaceguard, a coalition of worldwide observatories and scientists who find, track, and determine impact probabilities for potential EIs (Udall, 2007). This effort fits within the first stages of a typical military targeting cycle, which begins by detecting and characterizing targets. In the first half of this analysis, military targeting is applied to the EI challenge through the development of a methodology to characterize early warning times for different size objects. In the second half, recommendations for acting on different warning time scenarios are presented, to include augmentation of observation technology and use of a precursor transponder implantation mission. An interdisciplinary approach is taken to measure the success of the Spaceguard efforts in increasing the warning times for approaches of variously sized bodies. A multi-step method is developed, beginning with determining past and present warning times for asteroids entering the 0.05 AU Astronomical Unit (AU) Minimum Orbit Intersection Distance (MOID) of Earth. Using source data from NASA's NEO Program database of close approaches, JPL's Small Body Database, and the IAU Minor Planet Center, the differences between the dates of first discovery of these Potentially Hazardous Asteroids (PHA) and the dates of 7300 penetrations of the MOID to graph warning times for known PHAs' penetration of the MOID were aggregated. The method also includes the estimate of PHA discovery, rates of objects with high orbital uncertainties, and missed approach rates. A discussion of potential sources for error and directions to take for further development of the model is included. Finally, recommendations for campaigns against EIs are provided, given different warning time and size scenarios. The most significant of the conclusions is that, given current

  16. Dark-ray and dark-floor craters on Ganymede, and the provenance of large impactors in the Jovian system

    NASA Technical Reports Server (NTRS)

    Schenk, Paul M.; Mckinnon, William B.

    1991-01-01

    The dark-floor and dark-ray craters on the icy Jovian satellite, Ganymede, may derive their visual characteristics from impactor contamination. It is presently hypothesized that the rays darken as a result of the near-surface concentration of impactor material; this could occur, first, due to magnetic sputtering while the rays are bright, and subsequently, once a critical albedo is reached, due to thermal sublimation into discrete icy and nonicy patches. Voyager visible spectra of dark rays indicate that most large-ray systems are 'redder' than grooved or cratered terrains, and are among the 'reddest' units on Ganymede. More than half of the recent impactors on Ganymede may have been reddish D-type asteroids or comets, accounting for the albedos and colors of dark terrains on both Ganymede and Callisto.

  17. Dark-ray and dark-floor craters on Ganymede, and the provenance of large impactors in the Jovian system

    NASA Technical Reports Server (NTRS)

    Schenk, Paul M.; Mckinnon, William B.

    1991-01-01

    The dark-floor and dark-ray craters on the icy Jovian satellite, Ganymede, may derive their visual characteristics from impactor contamination. It is presently hypothesized that the rays darken as a result of the near-surface concentration of impactor material; this could occur, first, due to magnetic sputtering while the rays are bright, and subsequently, once a critical albedo is reached, due to thermal sublimation into discrete icy and nonicy patches. Voyager visible spectra of dark rays indicate that most large-ray systems are 'redder' than grooved or cratered terrains, and are among the 'reddest' units on Ganymede. More than half of the recent impactors on Ganymede may have been reddish D-type asteroids or comets, accounting for the albedos and colors of dark terrains on both Ganymede and Callisto.

  18. A comparative analysis of the pedestrian injury risk predicted by mechanical impactors and post mortem human surrogates.

    PubMed

    Kerrigan, Jason R; Crandall, Jeff R; Deng, Bing

    2008-11-01

    The objective of this study is to compare the risk of injury to pedestrians involved in vehicle-pedestrian impacts as predicted by two different types of risk assessment tools: the pedestrian subsystem impactors recommended by the European Enhanced Vehicle-Safety Committee (EEVC) and post-mortem human surrogates (PMHS). Seven replicate full-scale vehicle-pedestrian impact tests were performed with PMHS and a mid-sized sedan travelling at 40 km/h. The PMHS were instrumented with six-degree-of-freedom sensor cubes and sensor data were transformed and translated to predict impact kinematics at the head center of gravity, proximal tibiae, and knee joints. Single EEVC WG 17/EuroNCAP adult headform, upper legform and lower legform impactor tests of the same vehicle were selected for comparison based on the proximity of their impact locations to that of the PMHS. The PMHS experienced higher HIC values (1830/2160) and lower impact velocities (8.5/7.5 m/s) than the impactor (1532 and 11.1 m/s) in impacts at the lower fourth of the windshield. The lower legform impactor (31 degrees) and PMHS (right: 25-40 degrees, and left: 24-39 degrees) predicted similar maximum knee bending angles. Some PMHS tibial accelerations (114-613 g) exceeded the proposed acceptance criteria (150-200 g) in both the absence and presence of distal tibial fracture, with the impactor predicting a similar result (335 g). The upper legform impactor test resulted in bending moments (361 Nm) and forces (6.3 kN) exceeding the acceptance criteria, while PMHS sustained pelvic injuries in 6 out of 7 tests.

  19. Laser safety evaluation and output measurements for the VITAL -2 Variable Intensity Tactical Aiming Light (laser) used with the Proforce M-4 system in force-on-force exercises.

    SciTech Connect

    Augustoni, Arnold L.

    2004-02-01

    A laser safety hazard evaluation and pertinent output measurements were performed (June 2003 through August 2003) on several VITAL-2 Variable Intensity Tactical Aiming Light--infrared laser, associated with the Proforce M-4 system used in force-on-force exercises. The VITAL-2 contains two diode lasers presenting 'Extended Source' viewing out to a range on the order of 1.3 meters before reverting to a 'Small Source' viewing hazard. Laser hazard evaluation was performed in concert with the ANSI Std. Z136.1-2000 for the safe use of lasers and the ANSI Std. Z136.6-2000 for the safe use of lasers outdoors. The results of the laser hazard analysis for the VITAL-2, indicates that this Tactical Aiming IR laser presents a Class 1 laser hazard to personnel in the area of use. Field measurements performed on 71 units confirmed that the radiant outputs were at all times below the Allowable Emission Limit and that the irradiance of the laser spot was at all locations below the Maximum Exposure Limit. This system is eye-safe and it may be used under current SNL policy in force-on-force exercises. The VITAL-2 Variable Intensity Tactical Aiming Light does not present a laser hazard greater than Class 1, to aided viewing with binoculars.

  20. Orbital and physical characteristics of meter-scale impactors from airburst observations

    NASA Astrophysics Data System (ADS)

    Brown, P.; Wiegert, P.; Clark, D.; Tagliaferri, E.

    2016-03-01

    We have analyzed the orbits and ablation characteristics in the atmosphere of 59 Earth-impacting fireballs, produced by meteoroids 1 m in diameter or larger, described here as meter-scale. Using heights at peak luminosity as a proxy for strength, we determine that there is roughly an order of magnitude spread in strengths of the population of meter-scale impactors at the Earth. We use fireballs producing recovered meteorites and well documented fireballs from ground-based camera networks to calibrate our ablation model interpretation of the observed peak height of luminosity as a function of speed. The orbits and physical strength of these objects are consistent with the majority being asteroidal bodies originating from the inner main asteroid belt. This is in contrast to earlier suggestions by Ceplecha (Ceplecha, Z. [1994]. Astron. Astrophys. 286, 967-970) that the majority of meter-tens of meter sized meteoroids are ;… cometary bodies of the weakest known structure;. We find a lower limit of ∼10-15% of our objects have a possible cometary (Jupiter-Family comet and/or Halley-type comet) origin based on orbital characteristics alone. Only half this number, however, also show evidence for weaker than average structure. Two events, Sumava and USG 20131121, have exceptionally high (relative to the remainder of the population) heights of peak brightness. These are physically most consistent with high microporosity objects, though both were on asteroidal-type orbits. We also find three events, including the Oct 8, 2009 airburst near Sulawesi, Indonesia, which display comparatively low heights of peak brightness, consistent with strong monolithic stones or iron meteoroids. Based on orbital similarity, we find a probable connection among several events in our population with the Taurid meteoroid complex; no other major meteoroid streams show probable linkages to the orbits of our meter-scale population. Our impactors cover almost four orders of magnitude in mass, but

  1. The diverse aims of science.

    PubMed

    Potochnik, Angela

    2015-10-01

    There is increasing attention to the centrality of idealization in science. One common view is that models and other idealized representations are important to science, but that they fall short in one or more ways. On this view, there must be an intermediary step between idealized representation and the traditional aims of science, including truth, explanation, and prediction. Here I develop an alternative interpretation of the relationship between idealized representation and the aims of science. I suggest that continuing, widespread idealization calls into question the idea that science aims for truth. If instead science aims to produce understanding, this would enable idealizations to directly contribute to science's epistemic success. I also use the fact of widespread idealization to motivate the idea that science's wide variety aims, epistemic and non-epistemic, are best served by different kinds of scientific products. Finally, I show how these diverse aims—most rather distant from truth—result in the expanded influence of social values on science.

  2. An asteroid breakup 160 Myr ago as the probable source of the K/T impactor.

    PubMed

    Bottke, William F; Vokrouhlický, David; Nesvorný, David

    2007-09-06

    The terrestrial and lunar cratering rate is often assumed to have been nearly constant over the past 3 Gyr. Different lines of evidence, however, suggest that the impact flux from kilometre-sized bodies increased by at least a factor of two over the long-term average during the past approximately 100 Myr. Here we argue that this apparent surge was triggered by the catastrophic disruption of the parent body of the asteroid Baptistina, which we infer was a approximately 170-km-diameter body (carbonaceous-chondrite-like) that broke up 160(-20)+30Myr ago in the inner main asteroid belt. Fragments produced by the collision were slowly delivered by dynamical processes to orbits where they could strike the terrestrial planets. We find that this asteroid shower is the most likely source (>90 per cent probability) of the Chicxulub impactor that produced the Cretaceous/Tertiary (K/T) mass extinction event 65 Myr ago.

  3. Survival of the impactor during hypervelocity collisions - II. An analogue for high-porosity targets

    NASA Astrophysics Data System (ADS)

    Avdellidou, C.; Price, M. C.; Delbo, M.; Cole, M. J.

    2017-01-01

    We investigated how a target's porosity affects the outcome of a collision, with respect to the impactor's fate. Laboratory impact experiments using peridot projectiles were performed at a speed range between 0.3 and 3.0 km s-1, on to high-porosity water-ice (40 per cent) and fine-grained calcium carbonate (70 per cent) targets. We report that the amount of implanted material in the target body increases with increasing target's porosity, while the size frequency distribution of the projectile's ejecta fragments becomes steeper. A supplementary Raman study showed no sign of change of the Raman spectra of the recovered olivine projectile fragments indicate minimal physical change.

  4. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition.

    PubMed

    Shimaoka, T; Kaneko, J H; Arikawa, Y; Isobe, M; Sato, Y; Tsubota, M; Nagai, T; Kojima, S; Abe, Y; Sakata, S; Fujioka, S; Nakai, M; Shiraga, H; Azechi, H; Chayahara, A; Umezawa, H; Shikata, S

    2015-05-01

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10(7) cm/s and 1.0 ± 0.3 × 10(7) cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 10(9) neutrons/shot.

  5. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition

    SciTech Connect

    Shimaoka, T. Kaneko, J. H.; Tsubota, M.; Arikawa, Y.; Nagai, T.; Kojima, S.; Abe, Y.; Sakata, S.; Fujioka, S.; Nakai, M.; Shiraga, H.; Azechi, H.; Isobe, M.; Sato, Y.; Chayahara, A.; Umezawa, H.; Shikata, S.

    2015-05-15

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10{sup 7} cm/s and 1.0 ± 0.3 × 10{sup 7} cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5–1 keV and neutron yield of more than 10{sup 9} neutrons/shot.

  6. Development and Validation of a High-Volume, Low-Cutoff Inertial Impactor.

    PubMed

    Kavouras, I G; Ferguson, S T; Wolfson, J M; Koutrakis, P

    2000-01-01

    A low-cutoff, high-volume conventional impactor has been designed. This sampler uses a slit-shaped acceleration jet and operates at 1100 L/min. The impaction substrate is polyurethane foam (PUF). The impactor collection efficiency was characterized using polydisperse particles, and the 50% size cutoff point was 0.12 ¡m. Losses within the sampler were also characterized and were less than 10%. The use of polyurethane foam (PUF) as a substrate has the following advantages: (I) PUF has a very high particle collection efficiency over a large range of particle sizes, even under conditions of heavy particle loading, as compared to other impaction substrates, such as flat plates and less porous membranes, which typically are subject to significant bounce-off and reentrainment; (2) no oil or grease coating is required, so potential interferences of impurities within such coatings are avoided when chemical, biological, and toxicological tests are performed on the collected particles; (3) PUF itself is chemically inert, minimizing interference with any of these tests; (4) because of the high flow rate of 1100 L/min, a large amount of particles can be collected in a short period of time on a relatively small surface of substrate, facilitating recovery of the collected particles for the different tests; and (5) a large amount of particles can be collected on a relatively small collection surface and easily extracted with small amounts of water or organic solvents. This method will be suitable for the collection of large amounts for toxicological studies and analysis of organic aerosols, which is not possible with other high-volume samplers that utilize large filtration surfaces.

  7. Geochemical arguments for an Earth-like Moon-forming impactor.

    PubMed

    Dauphas, Nicolas; Burkhardt, Christoph; Warren, Paul H; Fang-Zhen, Teng

    2014-09-13

    Geochemical evidence suggests that the material accreted by the Earth did not change in nature during Earth's accretion, presumably because the inner protoplanetary disc had uniform isotopic composition similar to enstatite chondrites, aubrites and ungrouped achondrite NWA 5363/5400. Enstatite meteorites and the Earth were derived from the same nebular reservoir but diverged in their chemical evolutions, so no chondrite sample in meteorite collections is representative of the Earth's building blocks. The similarity in isotopic composition (Δ(17)O, ε(50)Ti and ε(54)Cr) between lunar and terrestrial rocks is explained by the fact that the Moon-forming impactor came from the same region of the disc as other Earth-forming embryos, and therefore was similar in isotopic composition to the Earth. The heavy δ(30)Si values of the silicate Earth and the Moon relative to known chondrites may be due to fractionation in the solar nebula/protoplanetary disc rather than partitioning of silicon in Earth's core. An inversion method is presented to calculate the Hf/W ratios and ε(182)W values of the proto-Earth and impactor mantles for a given Moon-forming impact scenario. The similarity in tungsten isotopic composition between lunar and terrestrial rocks is a coincidence that can be explained in a canonical giant impact scenario if an early formed embryo (two-stage model age of 10-20 Myr) collided with the proto-Earth formed over a more protracted accretion history (two-stage model age of 30-40 Myr). © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  8. Geochemical arguments for an Earth-like Moon-forming impactor

    PubMed Central

    Dauphas, Nicolas; Burkhardt, Christoph; Warren, Paul H.; Fang-Zhen, Teng

    2014-01-01

    Geochemical evidence suggests that the material accreted by the Earth did not change in nature during Earth's accretion, presumably because the inner protoplanetary disc had uniform isotopic composition similar to enstatite chondrites, aubrites and ungrouped achondrite NWA 5363/5400. Enstatite meteorites and the Earth were derived from the same nebular reservoir but diverged in their chemical evolutions, so no chondrite sample in meteorite collections is representative of the Earth's building blocks. The similarity in isotopic composition (Δ17O, ε50Ti and ε54Cr) between lunar and terrestrial rocks is explained by the fact that the Moon-forming impactor came from the same region of the disc as other Earth-forming embryos, and therefore was similar in isotopic composition to the Earth. The heavy δ30Si values of the silicate Earth and the Moon relative to known chondrites may be due to fractionation in the solar nebula/protoplanetary disc rather than partitioning of silicon in Earth's core. An inversion method is presented to calculate the Hf/W ratios and ε182W values of the proto-Earth and impactor mantles for a given Moon-forming impact scenario. The similarity in tungsten isotopic composition between lunar and terrestrial rocks is a coincidence that can be explained in a canonical giant impact scenario if an early formed embryo (two-stage model age of 10–20 Myr) collided with the proto-Earth formed over a more protracted accretion history (two-stage model age of 30–40 Myr). PMID:25114316

  9. AIM: Attracting Women into Sciences.

    ERIC Educational Resources Information Center

    Hartman, Icial S.

    1995-01-01

    Addresses how to attract more college women into the sciences. Attracting Women into Sciences (AIM) is a comprehensive approach that begins with advising, advertising, and ambiguity. The advising process includes dispelling stereotypes and reviewing the options open to a female basic science major. Interaction, involvement and instruction, finding…

  10. Carbonaceous or Ordinary Chondrite as the Impactor at the K/T Boundary? Clues from Os, W and Cr Isotopes

    NASA Astrophysics Data System (ADS)

    Quitté, G.; Robin, E.; Capmas, F.; Levasseur, S.; Rocchia, R.; Birck, J. L.; Allègre, C. J.

    2003-03-01

    Each kind of meteorite is characterized by a typical pattern of isotopic signatures. Therefore we combine Os, W and Cr isotopes data to try and define the nature of the impactor that hit the Earth 65 Myrs ago, at the time of the K/T boundary.

  11. Aims, assessments and workplace needs

    NASA Astrophysics Data System (ADS)

    Black, Paul

    1997-03-01

    This paper attempts to consider the aims that undergraduate physics degree courses actually reflect and serve in the light of the employment patterns of graduates and of the expressed needs of employers. Calling on evidence mainly from the UK, it reviews analyses of what degree examinations actually test, and goes on to quote criticisms of their courses and radical proposals to change them adopted by the senior physics professors in the UK. The discussion is then broadened by discussion of evidence, about the employment of graduates and about the priorities that some industrialists now give in the qualities that they look for when recruiting new graduates. The evidence leads to a view that radical changes are needed, both in courses and examinations, and that there is a need for university departments to work more closely with employers in re-formulating the aims and priorities in their teaching.

  12. Taking aim at infusion confusion.

    PubMed

    Burdeu, Gabrielle; Crawford, Ruth; van de Vreede, Melita; McCann, Joanne

    2006-01-01

    A comprehensive multidisciplinary approach was used to improve drug infusion safety in an acute care hospital in Melbourne, Australia. This project aimed to reduce the potential for drug infusion-related error, improve drug infusion safety for patients, and encourage incident reporting to inform and guide continuous quality improvement projects. The project applied a systems approach to medication safety, using redesign strategies such as continuous quality improvement (plan, do, study, and act) and re-engineering. Key safety design concepts such as standardization, simplification, and forcing functions were also used.

  13. China's educational aim and theory

    NASA Astrophysics Data System (ADS)

    Guang-Wei, Zou

    1985-12-01

    The aim and theory of Chinese socialist education is to provide scientific and technological knowledge so as to develop the productive forces and to meet the demands of the socialist cause. Since education is the main vehicle towards modernizing science and technology, any investment in education is viewed as being productive as it feeds directly into economics. Faced with the demands of industrial and agricultural production, training a technical as well as a labour force becomes crucial. This is made possible by the provision of two labour systems for workers both from rural as well as urban areas and by two kinds of educational systems for both urban and rural students. Chinese educational theory is seen as a fusion of principles from its own educational legacy with those of Marxist-Leninist principles.

  14. Simulation of the dusty plasma environment of 65803 Didymos for the Asteroid Impact Mission (AIM)

    NASA Astrophysics Data System (ADS)

    Cipriani, Fabrice; Rodgers, David; Hilgers, Alain; Hess, Sebastien; Carnelli, Ian

    2016-10-01

    The Asteroid Impact and Deflection Assessment mission (AIDA) is a joint European-US technology demonstrator mission including the DART asteroid impactor (NASA/JHU/APL) and the AIM asteroid rendezvous platform (ESA/DLR/OCA) set to reach Near Earth binary Object 65803 Didymos in October 2022. Besides technology demonstration in the deep space communications domain and the realization of a kinetic impact on the moonlet to study deflection parameters, this asteroid rendezvous mission is an opportunity to carry out in-situ observations of the close environment of a binary system, addressing some fundamental science questions. The MASCOT-2 lander will be released from the AIM platform and operate at the surface of the moonlet of 65803 Didymos, complemented by the ability of the Cubesat Opportunity Payloads (COPINS) to sample the close environment of the binary.In this context, we have developed an model describing the plasma and charged dust components of the near surface environment of the moonlet (170m in diameter), targeted by the MASCOT-2 lander and of the DART impactor. We performed numerical simulations in order to estimate the electrostatic surface potentials at various locations of the surface, resulting from its interaction with the solar wind plasma and solar photons. In addition, we describe charging levels, density profiles, and velocity distribution of regolith grains lifted out from the surface up to about 70m above the surface.

  15. Influence of rheology and giant impactors on the terrestrial core formation

    NASA Astrophysics Data System (ADS)

    Golabek, G. J.; Gerya, T.; Kaus, B. J.; Ziethe, R.; Moll, G.; Tackley, P. J.

    2009-12-01

    Knowledge about the terrestrial core formation mechanism is still very limited. Several core formation modes have been proposed: The fracturing mode suggests that a central unmelted region is displaced by a degree one mode from the center of the accreting body and is fragmented due to the large stresses created by an overlying asymmetric iron layer (Stevenson, 1981). In contrast, core formation via iron diapirs (e.g. Ziethe and Spohn, 2007), which can be formed by giant impacts (e.g. Ricard et al, 2009), has been proposed. We investigate which core formation mode is active under certain conditions. Therefore we perform 2D simulations using the code I2ELVIS applying the newly developed “spherical-Cartesian” methodology (Gerya and Yuen, 2007). It combines finite differences on a fully staggered rectangular Eulerian grid and Lagrangian marker-in-cell technique for solving momentum, continuity and temperature equations as well as the Poisson equation for gravity potential in a self-gravitating planetary body. In the model, the planetary body is surrounded by a low viscosity massless fluid (“sticky air”) to simulate a free surface. We apply a temperature- and stress-dependent viscoplastic rheology inside Mars- to Earth-sized bodies and include heat release due to radioactive decay, shear and adiabatic heating. As initial condition we use stochastically distributed iron diapirs with random sizes in the range of 50 to 100 km radius inside the accreting planet, representing the iron delivered by pre-differentiated impactors. Additionally, we add a giant impactor core into several models. For simplicity, we neglect the heating of the planetary body by the impact itself. We assume the impactor core to be at rest at the beginning of the simulation. A systematic investigation of the influence of silicate rheology, temperature and diapir radii on different-sized protoplanets is being performed. We show that depending on the silicate rheology, which is strongly dependent

  16. The effect of giant impactors on the magnetic field energy of an early Martian dynamo.

    NASA Astrophysics Data System (ADS)

    Drummond, McGregor; Thieulot, Cedric; Monteux, Julien

    2016-04-01

    Through the cratering record embedded on its surface, Mars is one of the key planets required for investigating the formation and impact frequency in the early history of our Solar System. This record also holds clues to the events that may have caused the observed hemispheric dichotomy and cessation of the magnetic field that was present within the first 500 Myr of the planets' formation. We investigate the influence of giant impacts on the early Martian dynamo using the numerical dynamo modelling code PARODY-JA [1]. We hypothesize that the input heat from a giant impact will decrease the total heat flux at the CMB through mantle heating which leads to a decrease in the Rayleigh number of the core. As boundary conditions for the heat flux anomaly size, we use numerical results of a 750 km diameter impactor from the Monteux and Arkani-Hamed, 2014 [2] study which investigated impact heating and core merging of giant impacts in early Mars. We also determine the decrease in Rayleigh number from the change in total heat flux at the CMB using these results, where the decrease after impact is due to shock heating at the CMB. We calculate the time-averaged total magnetic field energy for an initial homogeneous heat flux model using a range of Rayleigh numbers (5 x 103 - 1 x 10^5). The Rayleigh number is then decreased for three new models - homogeneous, north pole impact and equatorial impact - and the time-averaged energy again determined. We find that the energy decreases more in our impact models, compared with the homogeneous, along with a variation in energy between the north pole and equatorial impact models. We conclude that giant impacts in Mars' early history would have decreased the total magnetic energy of the field and the decrease in energy is also dependent on the location of the impact. The magnetic field could have been disrupted beyond recovery from a planetesimal-sized collision; such as the suggested Borealis basin forming impact, or through the

  17. Evidence for a second impactor at the K-Pg Boundary in Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    Santa Catharina, Amanda; Kneller, Benjamin Charles; Charao Marques, Juliana; McArthur, Adam Daniel; Kane, Ian Antony; Silvestre Cevallos Ferriz, Sergio Rafael

    2017-04-01

    reported in the surrounding areas, either in the Peninsular Ranges or the Sonora Desert, and the presence of shocked quartz and tektites in this unit compels us to believe that its origin is related to ejecta material from an impact. The distance of these thick and coarse grained deposits from the Chicxulub Impact site (c.2000 km) suggests that these deposits are not related to the Chicxulub Impactor, and therefore may have been generated by a different impact of a geologically similar age, but more proximal to this area. The occurrence of multiple impactors is not uncommon, and should be considered a possibility for the K-Pg Boundary.

  18. Development of a New Calibration Method for an Ambient Ion Monitor Ion Chromatograph (AIM-IC)

    NASA Astrophysics Data System (ADS)

    Markovic, M.; Vandenboer, T.; Murphy, J. G.

    2009-05-01

    Fine atmospheric aerosols play an important role in the atmosphere as they alter the radiative balance of the Earth through direct and indirect climate effects, reduce visibility, participate in acid rain formation and affect human health. The motivation for chemically and temporally resolved measurements of fine aerosol composition has lead to the development of the Ambient Ion Monitor Ion Chromatograph (AIM-IC) system by Dionex/URG. This instrument is capable of simultaneously monitoring fine aerosols (<2.5μm) and associated precursor gases on a nearly continuous basis with a time resolution of 1 hour. The instrument utilizes a parallel-plate wet denuder with a constantly regenerated surface for collection of gases and a particle condensation chamber for the collection of aerosols. AIM-IC is capable of monitoring HCl(g), HONO(g), HNO3(g), SO2(g), NH3(g), Cl-, NO2-, NO3-, SO42-, NH4+ , and some water soluble organic acids and amines. Standard calibration of the AIM-IC is carried out by injecting a series of mixed standards directly onto the ion chromatographs, bypassing the sampling component of the instrument. This results in calculated detection limits on the order of 10-200 pptv for gases and 10-500 of ng/m3 for individual particle constituents when collecting at 3 L/min for 55 minutes. In this work, we present a new method for the calibration of the AIM-IC for both gas and particle collection that enables us to evaluate the entire system from size-selection to detection. This external calibration method is assessed for the gases HNO3(g), SO2(g), and NH3(g), and for particles containing (NH4)2SO4, NH4NO3, and Na2SO4. Quantitative collection of SO2 is found to require careful optimization of the H2O2 concentration of the denuder liquid, while the replacement of a cyclone with an impactor improves the sampling efficiency of NH3 and HNO3.

  19. Environmental continuous air monitor inlet with combined preseparator and virtual impactor

    DOEpatents

    Rodgers, John C.

    2007-06-19

    An inlet for an environmental air monitor is described wherein a pre-separator interfaces with ambient environment air and removes debris and insects commonly associated with high wind outdoors and a deflector plate in communication with incoming air from the pre-separator stage, that directs the air radially and downward uniformly into a plurality of accelerator jets located in a manifold of a virtual impactor, the manifold being cylindrical and having a top, a base, and a wall, with the plurality of accelerator jets being located in the top of the manifold and receiving the directed air and accelerating directed air, thereby creating jets of air penetrating into the manifold, where a major flow is deflected to the walls of the manifold and extracted through ports in the walls. A plurality of receiver nozzles are located in the base of the manifold coaxial with the accelerator jets, and a plurality of matching flow restrictor elements are located in the plurality of receiver nozzles for balancing and equalizing the total minor flow among all the plurality of receiver nozzles, through which a lower, fractional flow extracts large particle constituents of the air for collection on a sample filter after passing through the plurality of receiver nozzles and the plurality of matching flow restrictor elements.

  20. Use of a New Portable Instrumented Impactor on the NASA Composite Crew Module Damage Tolerance Program

    NASA Technical Reports Server (NTRS)

    Jackson, Wade C.; Polis, Daniel L.

    2014-01-01

    Damage tolerance performance is critical to composite structures because surface impacts at relatively low energies may result in a significant strength loss. For certification, damage tolerance criteria require aerospace vehicles to meet design loads while containing damage at critical locations. Data from standard small coupon testing are difficult to apply to larger more complex structures. Due to the complexity of predicting both the impact damage and the residual properties, damage tolerance is demonstrated primarily by testing. A portable, spring-propelled, impact device was developed which allows the impact damage response to be investigated on large specimens, full-scale components, or entire vehicles. During impact, both the force history and projectile velocity are captured. The device was successfully used to demonstrate the damage tolerance performance of the NASA Composite Crew Module. The impactor was used to impact 18 different design features at impact energies up to 35 J. Detailed examples of these results are presented, showing impact force histories, damage inspection results, and response to loading.

  1. Stop hitting yourself: did most terrestrial impactors originate from the terrestrial planets?

    NASA Astrophysics Data System (ADS)

    Jackson, Alan; Asphaug, Erik; Elkins-Tanton, Linda

    2014-11-01

    Although the asteroid belt is the main source of impactors in the inner solar system today, it contains only 0.0006 Earth mass, or 0.05 Lunar mass. While the asteroid belt would have been more massive when it formed, it is unlikely to have had greater than 0.5 Lunar mass since the formation of Jupiter and the dissipation of the solar nebula. By comparison, giant impacts onto the terrestrial planets typically release debris equal to several per cent of the planets mass. The Moon-forming impact on Earth and the dichotomy forming impact on Mars, to consider but two of these major events, released 1.3 and 0.3 Lunar mass in debris respectively, many times the mass of the present day asteroid belt. This escaping impact debris is less long lived than the main asteroid belt, as it is injected on unstable, planet-crossing orbits, but this same factor also increases the impact probability with the terrestrial planets and asteroids. We show that as a result terrestrial ejecta played a major role in the impact history of the early inner solar system, and we expect the same is also likely to be true in other planetary systems.

  2. Determination of nebulizer droplet size distribution: a method based on impactor refrigeration.

    PubMed

    Berg, Elna; Svensson, Jan Olof; Asking, Lars

    2007-01-01

    Size distributions of droplets generated by nebulizers are difficult to determine because of evaporation after aerosolization. We describe a method whereby a Next Generation Pharmaceutical Impactor (NGI; MSP Corporation, Shoreview, MN) is refrigerated at 5 degrees C before connecting it to the nebulizer in order to ensure an environment inside the NGI at close to 100% relative humidity (RH). This, in turn, reduces droplet evaporation between the nebulizer and impaction. The method development was performed with a Pari LC Plus jet nebulizer operated at 2.0 bar, with the NGI set at a flow rate of 15 L/min and with salbutamol 5.0 mg/mL as the test solution. The droplet size distributions were expressed in terms of mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD). Variation in test conditions showed that the NGI should be cooled for at least 90 min, that nebulization should be started within 5 min after removal from the refrigerator, and that coating of collecting cups to prevent "bouncing" is not necessary. Variation of ambient temperature and humidity had no relevant effect on results. MMAD and GSD results showed that refrigeration of the NGI resulted in droplet size distributions that are likely to reflect those originally delivered at the mouthpiece by the nebulizer. The method was shown to be robust, accurate with recovery of test solutions exceeding 99%, reproducible, and to be suitable for use with a wide range of commercially available nebulizers.

  3. Review of the population of impactors and the impact cratering rate in the inner solar system

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; Morbidelli, Alessandro

    All terrestrial planets, the Moon, and small bodies of the inner solar system are subjected to impacts on their surface. The best witness of these events is the lunar surface, which kept the memory of the impacts that it underwent during the last 3.8 Gyr. In this paper, we review the recent studies at the origin of a reliable model of the impactor population in the inner solar system, namely the near-Earth object (NEO) population. Then we briefly expose the scaling laws used to relate a crater diameter to body size. The model of the NEO population and its impact frequency on terrestrial planets is consistent with the crater distribution on the lunar surface when appropriate scaling laws are used. Concerning the early phases of our solar system's history, a scenario has recently been proposed that explains the origin of the Late Heavy Bombardment (LHB) and some other properties of our solar system. In this scenario, the four giant planets had initially circular orbits, were much closer to each other, and were surrounded by a massive disk of planetesimals. Dynamical interactions with this disk destabilized the planetary system after 500-600 Myr. Consequently, a large portion of the planetesimal disk, as well as 95% of the Main Belt asteroids, were sent into the inner solar system, causing the LHB while the planets reached their current orbits. Our knowledge of solar system evolution has thus improved in the last decade despite our still-poor understanding of the complex cratering process.

  4. Investigation of dry powder inhaler (DPI) resistance and aerosol dispersion timing on emitted aerosol aerodynamic particle sizing by multistage cascade impactor when sampled volume is reduced from compendial value of 4 L.

    PubMed

    Mohammed, Hlack; Arp, Jan; Chambers, Frank; Copley, Mark; Glaab, Volker; Hammond, Mark; Solomon, Derek; Bradford, Kerry; Russell, Theresa; Sizer, Yvonne; Nichols, Steven C; Roberts, Daryl L; Shelton, Christopher; Greguletz, Roland; Mitchell, Jolyon P

    2014-10-01

    Compendial methods determining dry powder inhaler (DPI)-emitted aerosol aerodynamic particle size distribution (APSD) collect a 4-L air sample containing the aerosol bolus, where the flow, which propagates through the cascade impactor (CI) measurement system from the vacuum source, is used to actuate the inhaler. A previous article described outcomes with two CIs (Andersen eight-stage cascade impactor (ACI) and Next-Generation Pharmaceutical Impactor (NGI)) when the air sample volume was ≤4 L with moderate-resistance DPIs. This article extends that work, examining the hypothesis that DPI flow resistance may be a factor in determining outcomes. APSD measurements were made using the same CI systems with inhalers representing low and high flow resistance extremes (Cyclohaler® and HandiHaler® DPIs, respectively). The ratio of sample volume to internal dead space (normalized volume (V*)) was varied from 0.25 to 1.98 (NGI) and from 0.43 to 3.46 (ACI). Inhaler resistance was a contributing factor to the rate of bolus transfer; the higher resistance DPI completing bolus relocation to the NGI pre-separator via the inlet when V* was as small as 0.25, whereas only ca. 50% of the bolus mass was collected at this condition with the Cyclohaler® DPI. Size fractionation of the bolus from either DPI was completed within the ACI at smaller values of V* than within the NGI. Bolus transfer from the Cyclohaler® capsule and from the HandiHaler® to the ACI system were unaffected by the different flow rise time observed in the two different flow controller systems, and the effects the ACI-based on APSD measurements were marginal.

  5. A statistical dynamical study of meteorite impactors: A case study based on parameters derived from the Bosumtwi impact event

    NASA Astrophysics Data System (ADS)

    Galiazzo, M. A.; Bazsó, Á.; Huber, M. S.; Losiak, A.; Dvorak, R.; Koeberl, C.

    2013-11-01

    The study of meteorite craters on Earth provides information about the dynamic evolution of bodies within the Solar System. the Bosumtwi crater is a well studied, 10.5 km in diameter, ca. 1.07 Myr old impact structure located in Ghana. (Koeberl et al., 1997a). The impactor was ˜ 1 km in diameter, an ordinary chondrite and struck the Earth with an angle between 30o and 45o (Artemieva et al., 2004) from the horizontal. We have used a two phase backward integration to constrain the most probable parent region of the impactor. We find that the most likely source region is a high inclination object from the Middle Main Belt.

  6. Aerodynamic sizing of metered dose inhalers: an evaluation of the Andersen and Next Generation pharmaceutical impactors and their USP methods.

    PubMed

    Kamiya, Akihiko; Sakagami, Masahiro; Hindle, Michael; Byron, Peter R

    2004-07-01

    The particle sizing performance of a Next Generation Pharmaceutical Impactor (NGI) was compared to that of an Andersen cascade impactor (ACI). A single lot of Vanceril MDIs containing beclomethasone dipropionate (BDP) was used throughout. MDIs were sampled into NGI and ACI in accordance with USP recommendations, at 30.0 and 28.3 L/min, respectively, following 1, 2, 6, and 30 actuations with or without a silicone cup or stage coating, to determine the apparent particle size distributions (PSD) of BDP. The mass balance and the statistical comparability of drug deposits were assured on a "per actuation basis" across all experiments, demonstrating "good cascade impactor practices." Interstage deposition or "wall losses" in NGI were found to be lower than those in ACI, although their determination was laborious in NGI. The PSD profiles for Vanceril from a single actuation were distinguishable between NGI and ACI, when uncoated collection surfaces were used, most specifically for drug mass <4-microm aerodynamic diameter (p < 0.05). Silicone coating of collection surfaces and an increased number of actuations were shown to result in PSD profile shifts for both NGI and ACI. Such effects were most pronounced for NGI, although coating the collection surfaces and/or increasing the number of actuations improved drug retention significantly on the upper stages of NGI, and thereby, minimized the effects of particle bounce of BDP from Vanceril MDIs. PSD profiles from a single actuation could be determined reliably in either of these impactors, provided that coated collection surfaces were employed; also, cumulative % mass undersize profiles were similar between instruments. However, small differences in PSD profiles still existed to support NGI's design claims for reduced "overlap" in its stage collection efficiency curves. Copyright 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1828-1837, 2004

  7. Black carbon in cloud residual nuclei during PACDEX: Combining the single particle soot photometer and the counterflow virtual impactor

    NASA Astrophysics Data System (ADS)

    Kok, G.; Subramanian, R.; Twohy, C.; Baumgardner, D.

    2007-12-01

    The single particle soot photometer (SP2) measures black carbon (BC) using laser incandescence. In the PACific Dust EXperiment (PACDEX), the SP2 was operated downstream of a counterflow virtual impactor (CVI) during flight portions when the aircraft was passing through a cloud. The CVI collects cloud droplets and ice crystals larger than 5 μm and evaporates the water content, so that residual nuclei are sampled. The CVI also concentrates the incoming air-stream by as much as a factor of 30 or more. The combination of the SP2 with the CVI enables BC measurements below a few ng/m3. Preliminary results indicate that compared to aerosol in the surrounding air mass, black carbon concentrations (per unit volume air) were generally lower in cloud, but a greater fraction of cloud residual particles contain BC. Cloud residual nuclei also seem to contain more BC mass/particle than the ambient aerosol. The May 5 flight made a number of passes through a Pacific frontal system. During one such pass at 8.3 km ASL, BC in residual nuclei sampled through the CVI was on average 0.4 ng/m3 with a mean incandescent particle concentration of 0.1 particles/cm3, compared to over 7 ng/m3 and 2.5 particles/cm3 in ambient aerosol behind the front. For total concentrations over 0.2 particles/cm3 as detected by the SP2, the fraction of cloud nuclei that incandesced or contained BC was often greater than the incandescing fraction of the ambient aerosol at the same altitude, with up to 40% of cloud nuclei incandescing compared to ~10-25% for ambient aerosol. BC mass distributions peaked around 5 fg-BC/particle in ambient air. Inside the front, BC mass distributions in cloud nuclei were broader with peaks between 10-23 fg-BC/particle. Possible explanations for these results are that either BC-containing particles are scavenged by clouds, or these particles are good cloud nuclei, with larger aerosol containing more BC mass/particle preferentially forming cloud droplets and ice crystals.

  8. Preliminary Analysis of Delta-V Requirements for a Lunar CubeSat Impactor with Deployment Altitude Variations

    NASA Astrophysics Data System (ADS)

    Song, Young-Joo; Ho, Jin; Kim, Bang-Yeop

    2015-09-01

    Characteristics of delta-V requirements for deploying an impactor from a mother-ship at different orbital altitudes are analyzed in order to prepare for a future lunar CubeSat impactor mission. A mother-ship is assumed to be orbiting the moon with a circular orbit at a 90 deg inclination and having 50, 100, 150, 200 km altitudes. Critical design parameters that are directly related to the success of the impactor mission are also analyzed including deploy directions, CubeSat flight time, impact velocity, and associated impact angles. Based on derived delta-V requirements, required thruster burn time and fuel mass are analyzed by adapting four different miniaturized commercial onboard thrusters currently developed for CubeSat applications. As a result, CubeSat impact trajectories as well as thruster burn characteristics deployed at different orbital altitudes are found to satisfy the mission objectives. It is concluded that thrust burn time should considered as the more critical design parameter than the required fuel mass when deducing the onboard propulsion system requirements. Results provided through this work will be helpful in further detailed system definition and design activities for future lunar missions with a CubeSat-based payload.

  9. Exploring pulse shaping for Z using graded-density impactors on gas guns (final report for LDRD project 79879).

    SciTech Connect

    Furnish, Michael David; Reinhart, William Dodd; Anderson, William W. (Los Alamos National Laboratory, Los Alamos, NM); Vogler, Tracy John; Hixson, Rob (Los Alamos National Laboratory, Los Alamos, NM); Kipp, Marlin E.

    2005-10-01

    While isentropic compression experiment (ICE) techniques have proved useful in deducing the high-pressure compressibility of a wide range of materials, they have encountered difficulties where large-volume phase transitions exist. The present study sought to apply graded-density impactor methods for producing isentropic loading to planar impact experiments to selected such problems. Cerium was chosen due to its 20% compression between 0.7 and 1.0 GPa. A model was constructed based on limited earlier dynamic data, and applied to the design of a suite of experiments. A capability for handling this material was installed. Two experiments were executed using shock/reload techniques with available samples, loading initially to near the gamma-alpha transition, then reloading. As well, two graded-density impactor experiments were conducted with alumina. A method for interpreting ICE data was developed and validated; this uses a wavelet construction for the ramp wave and includes corrections for the ''diffraction'' of wavelets by releases or reloads reflected from the sample/window interface. Alternate methods for constructing graded-density impactors are discussed.

  10. Features of the destruction of homogeneous and composite barriers during high-speed interactions with rod impactors

    NASA Astrophysics Data System (ADS)

    Zakharov, V. M.; Tabachenko, A. N.; Afanas'eva, S. A.

    2017-07-01

    The destruction of homogeneous and composite barriers with metal-ceramic intermediate layers that interact with WNiFe-90 alloy impactors has been investigated. A comparison of the results for different types of barriers was provided based on the weight equivalence, i.e., the equality of weight per unit barrier area along the thickness. The initial impact velocity was in the range of 0.8-1.1 km/s. The registration of the process from the moment of strike of impactor to the formation of the developed fragmentation flow behind the barrier was carried out by a high-speed video camera. The displacement-time dependences for the characteristic planes of the target configuration, i.e., the rear end of the impactor and the rear surface of the barrier were plotted by processing video film. An analysis of these dependences allowed us to identify the features of barrier destruction. The strong difference in the geometry of the zones of destruction and the dynamics of the process for monolithic and composite barriers has been noted.

  11. Constraints on the pre-impact orbits of Theia, the Borealis impactor and the progenitor of Mercury

    NASA Astrophysics Data System (ADS)

    Jackson, Alan P.; Gabriel, Travis; Asphaug, Erik

    2016-10-01

    Many aspects of the current dynamical and compositional configuration of the inner Solar System, such as Mercury's large core mass fraction, the angular momentum of the Earth-Moon system, and the reorientation of Mars, have been achieved through the effects of giant impacts. It is possible to relate the impact conditions, especially the velocity, to the pre-impact orbits. This in turn provides insight into the source regions for the terrestrial planets for comparison with N-body accretion models. For example, in the case of the canonical model for the formation of the Moon, previous studies have investigated regions in which the Mars-size impactor, Theia, could be quasi-stable for millions of years. We can however obtain constraints on the orbit of an impactor immediately prior to collision simply by knowing the impact velocity. We consider the canonical Moon formation model, as well as the models of Cuk & Stewart (2012), Canup (2012) and Reufer et al. (2012), to derive from each model its constraints on the pre-impact orbit of Theia. We also consider Mars, and provide constraints on the pre-impact orbit of the impactor suggested to have formed the Borealis basin, and Mercury, namely the Benz et al. (2007) scenario for the formation of Mercury. We discuss the implication of these pre-impact orbits for the origin of the bodies and their compositions.

  12. Internal Materials and structural Investigations of C-type Asteroid using carry-on Impactor by Hayabusa-2

    NASA Astrophysics Data System (ADS)

    Okamoto, Chisato; Takagi, Yasuhiko; Yano, Hajime; Saiki, Takanao; Tsuda, Yuichi; Yoshikawa, Makoto

    Recent explorations carried out by spacecraft provided important information regarding the physical properties of asteroids, particularly their bulk density and surface morphology. For example, Hayabusa spacecraft launched in 2003 investigated 25143 Itokawa, an S-type asteroid, after it arrived at 25143 Itokawa in September, 2005. Hayabusa has made a large amount of scientific discoveries and technological achievements during its stay, and left Itokawa in December, 2005 in order to deliver us the surface material. Observations by the Hayabusa spacecraft revealed that 25143 Itokawa has a rubble-pile structure owing to the re-accumulation of disrupted impact fragments. Itokawa has a high porosity (˜40%), probably because of the macro-porosity among the disrupted fragments. Based on such previous observations, it is proposed that the internal structures of asteroids have diversity in bulk densities and porosities. However, we have no direct observational data for the internal structure and materials. It is possible that the surface materials of small bodies seriously damaged by cosmic ray exposure. Thus, we should investigate the chemical and physical properties of the internal material. Also, we need to investigate the internal structure in order to understand the formation history. Now we are planning the study of the next asteroid exploration mission in 2014. From the point of the scientific objective, 1999 JU3, a C-type asteroid, was chosen as the target; C-type asteroids are considered to have more primitive material such as organic matters in comparison to Itokawa, an S-type asteroid. The spacecraft called as Hayabusa-2 basically follows the design of Hayabusa spacecraft. But, we will develop some new equipment to investigate the C-type asteroid, especially a carry-on impactor for the internal materials and structural investigations. The impactor will be shoot on the asteroid at ˜2km/s in order to expose the internal materials via crater formation and induce

  13. Size-separated sampling and analysis of isocyanates in workplace aerosols. Part I. Denuder--cascade impactor sampler.

    PubMed

    Dahlin, Jakob; Spanne, Mårten; Karlsson, Daniel; Dalene, Marianne; Skarping, Gunnar

    2008-07-01

    Isocyanates in the workplace atmosphere are typically present both in gas and particle phase. The health effects of exposure to isocyanates in gas phase and different particle size fractions are likely to be different due to their ability to reach different parts in the respiratory system. To reveal more details regarding the exposure to isocyanate aerosols, a denuder-impactor (DI) sampler for airborne isocyanates was designed. The sampler consists of a channel-plate denuder for collection of gaseous isocyanates, in series with three-cascade impactor stages with cut-off diameters (d(50)) of 2.5, 1.0 and 0.5 mum. An end filter was connected in series after the impactor for collection of particles smaller than 0.5 mum. The denuder, impactor plates and the end filter were impregnated with a mixture of di-n-butylamine (DBA) and acetic acid for derivatization of the isocyanates. During sampling, the reagent on the impactor plates and the end filter is continuously refreshed, due to the DBA release from the impregnated denuder plates. This secures efficient derivatization of all isocyanate particles. The airflow through the sampler was 5 l min(-1). After sampling, the samples containing the different size fractions were analyzed using liquid chromatography-mass spectrometry (LC-MS)/MS. The DBA impregnation was stable in the sampler for at least 1 week. After sampling, the DBA derivatives were stable for at least 3 weeks. Air sampling was performed in a test chamber (300 l). Isocyanate aerosols studied were thermal degradation products of different polyurethane polymers, spraying of isocyanate coating compounds and pure gas-phase isocyanates. Sampling with impinger flasks, containing DBA in toluene, with a glass fiber filter in series was used as a reference method. The DI sampler showed good compliance with the reference method, regarding total air levels. For the different aerosols studied, vast differences were revealed in the distribution of isocyanate in gas and

  14. Aeronomy of Ice in the Mesosphere (AIM)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The overall goal of the Aeronomy of Ice in the Mesosphere (AIM) experiment is to resolve why Polar Mesospheric Clouds form and why they vary. By measuring PMCs and the thermal, chemical and dynamical environment in which they form, we will quanti@ the connection between these clouds and the meteorology of the polar mesosphere. In the end, this will provide the basis for study of long-term variability in the mesospheric climate and its relationship to global change. The results of AIM will be a rigorous validation of predictive models that can reliably use past PMC changes and present trends as indicators of global change. The AIM goal will be achieved by measuring PMC extinction, brightness, spatial distribution, particle size distributions, gravity wave activity, dust influx to the atmosphere and precise, vertical profile measurements of temperature, H20, C&, 0 3 , C02, NO. and aerosols. These data can only be obtained by a complement of instruments on an orbiting spacecraft (S/C).

  15. Chemical Characterisation of Atmospheric Aerosol In An Urban Site (milan, North Italy):two Impactors Comparison

    NASA Astrophysics Data System (ADS)

    Mangoni, M.; Cavicchioli, C.

    During summer 2000 and 2001 two sampling campaigns for tropospheric aerosol have been carried out at the layer of Milan urban area (Northern Italy). The particulate matter has been sampled by two Cascade Impactors (CIs, 5 impaction stages, collection range: 0.5-10 µm), loaded in different ways to verify the equivalence of the two instruments and sampling supports. Evermore during the second campaign the two CI have been compared with a bulk sampler (loaded with Whatmann 41) and an automatic monitoring system (TEOM). The aerosol mass has been evaluated by gravimetry and analysed for principal components ((NH4)2SO4, NH4NO3, Mineral Salts (MS), Organic Mass (OM), Elemental Carbon (EC)). The results of these experiments show that: 1. The two CIs sample the same quantity of particulate matter both on total than on each stage, independently from the atmospheric conditions and the loading modality . The chemical composition's size distribution of the sampled mass is also the same 2. In general the aerosol captured during these campaigns is especially concentrated on third stage corresponding to particles of aerodynamic diameter between 0.43 and 1.22 µm, expcept than an episode of preponderance of finer aerosol observed during the second week of 2000 campaign 3. The principal components of the particulate matter are (NH4)2SO4, NH4NO3 followed by OM and EC. MS are the lowest contributors 4. The aerosol chemical composition is different according to the particles dimensions: (NH4)2SO4, NH4NO3 are prevalent in particles bigger than 0.43 µm, where in the finer ones OM is the principal component and EC shows the maximum percentage. The MS concentration grows with particles dimension. 5. The correlation between NH4 and SO4+NO3 (neq/m3) shows, in the majority of samples, these components form the corresponding salts. In the particles smaller than 0.43 µm Ammonium, Nitrate and Solfate ions are present only as (NH4)2SO4, NH4NO3, while in the bigger particles the Na+ and Ca

  16. Micro-abrasion package capture cell experiment on the trailing edge of LDEF: Impactor chemistry and whipple bumper shield efficiencies

    NASA Technical Reports Server (NTRS)

    Fitzgerald, Howard J.; Yano, Hajime

    1995-01-01

    Four of the eight available double layer microparticle capture cells, flown as the experiment A0023 on the trailing (West) face of LDEF, have been extensively studied. An investigation of the chemistry of impactors has been made using SEM/EDX techniques and the effectiveness of the capture cells as bumper shields has also been examined. Studies of these capture cells gave positive EDX results, with 53 percent of impact sites indicating the presence of some chemical residues, the predominant residue identified as being silicon in varying quantities.

  17. Product lifecycle approach to cascade impaction measurements.

    PubMed

    Tougas, Terrence P; Christopher, Dave; Mitchell, Jolyon; Lyapustina, Svetlana; Van Oort, Michiel; Bauer, Richard; Glaab, Volker

    2011-03-01

    Over the lifecycle of an orally inhaled product (OIP), multi-stage cascade impactor (CI) measurements are used for different purposes and to address different questions. Full-resolution CIs can provide important information during product development and are widely used but are time- and resource-intensive, highly variable, and suboptimal for OIP quality control (QC) testing. By contrast, Efficient Data Analysis (EDA) combined with Abbreviated Impactor Measurement (AIM) systems pertinent either for QC and-possibly-for adult Human Respiratory Tract (pHRT) has been introduced for OIP performance assessment during and post-development. This article summarizes available evidence and discusses a strategy for using either abbreviated or full-resolution CI systems depending on the purpose of the measurement, such that adequate, accurate, and efficient testing of aerodynamic particle size distribution (APSD) of OIPs can be achieved throughout the lifecycle of a product. Under these proposals, a comprehensive testing program should initially be conducted by full-resolution CI in OIP development to ascertain the product's APSD. Subsequently, correlations should be established from the selected AIM CIs to the corresponding full-resolution system, ideally developing specifications common to both techniques. In the commercial phase, it should be possible to release product using AIM/EDA, keeping the full-resolution CI for investigations, change control, and trouble-shooting, thus optimizing resources for APSD characterization throughout the product lifecycle. If an in vitro-in vivo relationship is established and clinically relevant sizes are known, an AIM-pHRT could serve as a quick indicator that clinically relevant fractions have not changed and also, in the management of post-approval changes. © 2011 American Association of Pharmaceutical Scientists

  18. Cascade impactor practice for a high dose dry powder inhaler at 90 L/min: NGI versus modified 6-stage and 8-stage ACI.

    PubMed

    Kamiya, Akihiko; Sakagami, Masahiro; Byron, Peter R

    2009-03-01

    The compendial methods of particle size distribution (PSD) profile determination for dry powder inhalers (DPIs) were compared between the Next Generation Pharmaceutical Impactor (NGI) and the Andersen Cascade Impactor (ACI). Relenza Rotadisk (zanamivir) and Diskhaler was used as a model DPI and sampled into each impactor via its preseparator (PS), at 90 L/min under various protocols. In the NGI, silicone coating was shown to be indispensable to prevent or minimize particle bounce and reentrainment, and to reduce wall losses to the levels acceptable to the compendia (5%). In contrast, the ACI exceeded this 5% limit, regardless of coating, implying different wall loss mechanisms from the NGI. Particle bounce occurred in both impactors, inaccurately undersizing the PSD profiles for Relenza, unless the collection surfaces were coated or an increased number of doses were employed. Hence, the PSD profile for Relenza following single dose collection in the stage-coated NGI was the most accurate. In contrast, the use of the ACI and its PS for Relenza at 90 L/min suffered from several problems, even though the poorly designed PS still resulted in consistent impactor dose and PSD profiles, compared to those obtained from the NGI and its PS.

  19. Application of the modified chi-square ratio statistic in a stepwise procedure for cascade impactor equivalence testing.

    PubMed

    Weber, Benjamin; Lee, Sau L; Delvadia, Renishkumar; Lionberger, Robert; Li, Bing V; Tsong, Yi; Hochhaus, Guenther

    2015-03-01

    Equivalence testing of aerodynamic particle size distribution (APSD) through multi-stage cascade impactors (CIs) is important for establishing bioequivalence of orally inhaled drug products. Recent work demonstrated that the median of the modified chi-square ratio statistic (MmCSRS) is a promising metric for APSD equivalence testing of test (T) and reference (R) products as it can be applied to a reduced number of CI sites that are more relevant for lung deposition. This metric is also less sensitive to the increased variability often observed for low-deposition sites. A method to establish critical values for the MmCSRS is described here. This method considers the variability of the R product by employing a reference variance scaling approach that allows definition of critical values as a function of the observed variability of the R product. A stepwise CI equivalence test is proposed that integrates the MmCSRS as a method for comparing the relative shapes of CI profiles and incorporates statistical tests for assessing equivalence of single actuation content and impactor sized mass. This stepwise CI equivalence test was applied to 55 published CI profile scenarios, which were classified as equivalent or inequivalent by members of the Product Quality Research Institute working group (PQRI WG). The results of the stepwise CI equivalence test using a 25% difference in MmCSRS as an acceptance criterion provided the best matching with those of the PQRI WG as decisions of both methods agreed in 75% of the 55 CI profile scenarios.

  20. A matched pair cluster randomized implementation trail to measure the effectiveness of an intervention package aiming to decrease perinatal mortality and increase institution-based obstetric care among indigenous women in Guatemala: study protocol.

    PubMed

    Kestler, Edgar; Walker, Dilys; Bonvecchio, Anabelle; de Tejada, Sandra Sáenz; Donner, Allan

    2013-03-21

    Maternal and perinatal mortality continue to be a high priority problem on the health agendas of less developed countries. Despite the progress made in the last decade to quantify the magnitude of maternal mortality, few interventions have been implemented with the intent to measure impact directly on maternal or perinatal deaths. The success of interventions implemented in less developed countries to reduce mortality has been questioned, in terms of the tendency to maintain a clinical perspective with a focus on purely medical care separate from community-based approaches that take cultural and social aspects of maternal and perinatal deaths into account. Our innovative approach utilizes both the clinical and community perspectives; moreover, our study will report the weight that each of these components may have had on reducing perinatal mortality and increasing institution-based deliveries. A matched pair cluster-randomized trial will be conducted in clinics in four rural indigenous districts with the highest maternal mortality ratios in Guatemala. The individual clinic will serve as the unit of randomization, with 15 matched pairs of control and intervention clinics composing the final sample. Three interventions will be implemented in indigenous, rural and poor populations: a simulation training program for emergency obstetric and perinatal care, increased participation of the professional midwife in strengthening the link between traditional birth attendants (TBA) and the formal health care system, and a social marketing campaign to promote institution-based deliveries. No external intervention is planned for control clinics, although enhanced monitoring, surveillance and data collection will occur throughout the study in all clinics throughout the four districts. All obstetric events occurring in any of the participating health facilities and districts during the 18 months implementation period will be included in the analysis, controlling for the cluster

  1. A matched pair cluster randomized implementation trail to measure the effectiveness of an intervention package aiming to decrease perinatal mortality and increase institution-based obstetric care among indigenous women in Guatemala: study protocol

    PubMed Central

    2013-01-01

    Background Maternal and perinatal mortality continue to be a high priority problem on the health agendas of less developed countries. Despite the progress made in the last decade to quantify the magnitude of maternal mortality, few interventions have been implemented with the intent to measure impact directly on maternal or perinatal deaths. The success of interventions implemented in less developed countries to reduce mortality has been questioned, in terms of the tendency to maintain a clinical perspective with a focus on purely medical care separate from community-based approaches that take cultural and social aspects of maternal and perinatal deaths into account. Our innovative approach utilizes both the clinical and community perspectives; moreover, our study will report the weight that each of these components may have had on reducing perinatal mortality and increasing institution-based deliveries. Methods/Design A matched pair cluster-randomized trial will be conducted in clinics in four rural indigenous districts with the highest maternal mortality ratios in Guatemala. The individual clinic will serve as the unit of randomization, with 15 matched pairs of control and intervention clinics composing the final sample. Three interventions will be implemented in indigenous, rural and poor populations: a simulation training program for emergency obstetric and perinatal care, increased participation of the professional midwife in strengthening the link between traditional birth attendants (TBA) and the formal health care system, and a social marketing campaign to promote institution-based deliveries. No external intervention is planned for control clinics, although enhanced monitoring, surveillance and data collection will occur throughout the study in all clinics throughout the four districts. All obstetric events occurring in any of the participating health facilities and districts during the 18 months implementation period will be included in the analysis

  2. Light-Absorbing Carbon in Cloud Residual Nuclei During ICE-L: Combining the Single Particle Soot Photometer and the Counterflow Virtual Impactor

    NASA Astrophysics Data System (ADS)

    Subramanian, R.; Kok, G. L.; Baumgardner, D.; Twohy, C.

    2008-12-01

    The single particle soot photometer (SP2) measures strongly-light absorbing (black) carbon (LAC) using laser incandescence. During the Ice in Clouds Experiment (ICE-L) conducted over Colorado and Wyoming in November/December 2007, the SP2 was operated downstream of a counterflow virtual impactor (CVI) onboard the NCAR C-130 aircraft, when the plane passed through a cloud. The CVI collects cloud droplets and ice crystals larger than 8 μm and evaporates the water content, so that residual nuclei are sampled. The CVI also concentrates the incoming air-stream by as much as a factor of 30 or more. The combination enables measurements of LAC much lower than 1 ng/m3. Results indicate that compared to aerosol in the surrounding air mass, LAC concentrations (per unit volume air) were generally lower in cloud. On November 16, two wave clouds were sampled near Riverton and Wheatland, WY at altitudes between 6-8 km above sea level. LAC mass concentrations upwind of the clouds averaged 5.6 and 4 ng/m3, while in- cloud averages were 0.6 and 0.3 ng/m3 respectively. Average number scavenging ratios of LAC- containing particles measured by the SP2 were 17% and 14% for the two mixed liquid/ice cloud events. In- cloud LAC mass normalized to cloud water content (CWC) was 19 ng/g-CWC in the Riverton cloud, and lower over Wheaton. Multiple passes at different altitudes through the cloud nearer Wheaton did not show a dependence of LAC/CWC on altitude. In a wave cloud over the Wind River Range on November 29, ice-only portions showed LAC/CWC about a factor-of-4 lower than smaller mixed-phase regions of the cloud. Data on LAC measurements in upslope conditions will also be presented.

  3. Examining Primary Healthcare Performance through a Triple Aim Lens

    PubMed Central

    Ryan, Bridget L.; Brown, Judith Belle; Glazier, Richard H.; Hutchison, Brian

    2016-01-01

    Purpose: This study sought to apply a Triple Aim framework to the measurement and evaluation of primary healthcare (PHC) team performance. Methods: Triple Aim components were populated with 10 dimensions derived from survey and health administrative data for 17 Family Health Teams (FHTs) in Ontario, Canada. Bivariate analyses and rankings of sites examined the relationships among dimensions and among Triple Aim components. Results: Readily available measures to fully populate the Triple Aim framework were lacking in FHTs. Within sites, there was little consistency in performance across the Triple Aim components (health, patient experience and cost). Conclusions: More and better measures are needed that can be readily used to examine the Triple Aim performance in PHC teams. FHTs, in this study, are partially achieving Triple Aim goals; however, there was a lack of consistency in performance. It is essential to collect appropriate measures and attend to performance across all components of the Triple Aim. PMID:27027790

  4. On correlations in IMRT planning aims.

    PubMed

    Roy, Arkajyoti; Das, Indra J; Nohadani, Omid

    2016-11-01

    The purpose was to study correlations amongst IMRT DVH evaluation points and how their relaxation impacts the overall plan. 100 head-and-neck cancer cases, using the Eclipse treatment planning system with the same protocol, are statistically analyzed for PTV, brainstem, and spinal cord. To measure variations amongst the plans, we use (i) interquartile range (IQR) of volume as a function of dose, (ii) interquartile range of dose as a function of volume, and (iii) dose falloff. To determine correlations for institutional and ICRU goals, conditional probabilities and medians are computed. We observe that most plans exceed the median PTV dose (average D50 = 104% prescribed dose). Furthermore, satisfying D50 reduced the probability of also satisfying D98, constituting a negative correlation of these goals. On the other hand, satisfying D50 increased the probability of satisfying D2, suggesting a positive correlation. A positive correlation is also observed between the PTV V105 and V110. Similarly, a positive correlation between the brainstem V45 and V50 is measured by an increase in the conditional median of V45, when V50 is violated. Despite the imposed institutional and international recommendations, significant variations amongst DVH points can occur. Even though DVH aims are evaluated independently, sizable correlations amongst them are possible, indicating that some goals cannot be satisfied concurrently, calling for unbiased plan criteria. PACS number(s): 87.55.dk, 87.53.Bn, 87.55.Qr, 87.55.de.

  5. On correlations in IMRT planning aims.

    PubMed

    Roy, Arkajyoti; Das, Indra J; Nohadani, Omid

    2016-11-08

    The purpose was to study correlations amongst IMRT DVH evaluation points and how their relaxation impacts the overall plan. 100 head-and-neck cancer cases, using the Eclipse treatment planning system with the same protocol, are statisti-cally analyzed for PTV, brainstem, and spinal cord. To measure variations amongst the plans, we use (i) interquartile range (IQR) of volume as a function of dose, (ii) interquartile range of dose as a function of volume, and (iii) dose falloff. To determine correlations for institutional and ICRU goals, conditional probabilities and medians are computed. We observe that most plans exceed the median PTV dose (average D50 = 104% prescribed dose). Furthermore, satisfying D50 reduced the probability of also satisfying D98, constituting a negative correlation of these goals. On the other hand, satisfying D50 increased the probability of satisfying D2, suggesting a positive correlation. A positive correlation is also observed between the PTV V105 and V110. Similarly, a positive correlation between the brainstem V45 and V50 is measured by an increase in the conditional median of V45, when V50 is violated. Despite the imposed institutional and international recommenda-tions, significant variations amongst DVH points can occur. Even though DVH aims are evaluated independently, sizable correlations amongst them are possible, indicating that some goals cannot be satisfied concurrently, calling for unbiased plan criteria.

  6. ASPECT spectral imaging satellite proposal to AIDA/AIM CubeSat payload

    NASA Astrophysics Data System (ADS)

    Kohout, Tomas; Näsilä, Antti; Tikka, Tuomas; Penttilä, Antti; Muinonen, Karri; Kestilä, Antti; Granvik, Mikael; Kallio, Esa

    2016-04-01

    ASPECT (Asteroid Spectral Imaging Mission) is a part of AIDA/AIM project and aims to study the composition of the Didymos binary asteroid and the effects of space weathering and shock metamorphism in order to gain understanding of the formation and evolution of the Solar System. The joint ESA/NASA AIDA (Asteroid Impact & Deflection Assessment) mission to binary asteroid Didymos consists of AIM (Asteroid Impact Mission, ESA) and DART (Double Asteroid Redirection Test, NASA). DART is targeted to impact Didymos secondary component (Didymoon) and serve as a kinetic impactor to demonstrate deflection of potentially hazardous asteroids. AIM will serve as an observational spacecraft to evaluate the effects of the impact and resulting changes in the Didymos dynamic parameters. The AIM mission will also carry two CubeSat miniaturized satellites, released in Didymoon proximity. This arrangement opens up a possibility for secondary scientific experiments. ASPECT is one of the proposed CubeSat payloads. Whereas Didymos is a space-weathered binary asteroid, the DART impactor is expected to produce a crater and excavate fresh material from the secondary component (Didymoon). Spectral comparison of the mature surface to the freshly exposed material will allow to directly deter-mine space weathering effects. It will be also possible to study spectral shock effects within the impact crater. ASPECT will also demonstrate for the first time the joint spacecraft - CubeSat operations in asteroid proximity and miniature spectral imager operation in deep-space environment. Science objectives: 1. Study of the surface composition of the Didymos system. 2. Photometric observations (and modeling) under varying phase angle and distance. 3. Study of space weathering effects on asteroids (comparison of mature / freshly exposed material). 4. Study of shock effects (spectral properties of crater interior). 5. Observations during the DART impact. Engineering objectives: 1. Demonstration of Cube

  7. Research on Impact Stress and Fatigue Simulation of a New Down-to-the-Hole Impactor Based on ANSYS

    NASA Astrophysics Data System (ADS)

    Wu, Tao; Wang, Wei; Yao, Aiguo; Li, Yongbo; He, Wangyong; Fei, Dongdong

    2016-06-01

    In the present work, a down-to-the-hole electric hammer driven by linear motor is reported for drilling engineering. It differs from the common hydraulic or pneumatic hammers in that it can be applied to some special occasions without circulating medium due to its independence of the drilling fluid. The impact stress caused by the reciprocating motion between stator and rotor and the fatigue damage in key components of linear motor are analyzed by the ANSYS Workbench software and 3D model. Based on simulation results, the hammer's structure is optimized by using special sliding bearing, increasing the wall thickness of key and multilayer buffer gasket. Fatigue life and coefficient issues of the new structure are dramatically improved. However buffer gasket reduces the impactor's energy, different bumper structure effect on life improving and energy loss have also been elaborated.

  8. Micrometeoroid Impacts on the Hubble Sace Telescope Wide Field and Planetary Camera 2: Ion Beam Analysis of Subtle Impactor Traces

    NASA Technical Reports Server (NTRS)

    Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V. V.; Colaux, J. L.; Kearsley, A. T.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; Griffin, T.; Gerlach, L.; Wozniakiewicz, P. J.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2014-01-01

    Recognition of origin for particles responsible for impact damage on spacecraft such as the Hubble Space Telescope (HST) relies upon postflight analysis of returned materials. A unique opportunity arose in 2009 with collection of the Wide Field and Planetary Camera 2 (WFPC2) from HST by shuttle mission STS-125. A preliminary optical survey confirmed that there were hundreds of impact features on the radiator surface. Following extensive discussion between NASA, ESA, NHM and IBC, a collaborative research program was initiated, employing scanning electron microscopy (SEM) and ion beam analysis (IBA) to determine the nature of the impacting grains. Even though some WFPC2 impact features are large, and easily seen without the use of a microscope, impactor remnants may be hard to find.

  9. Particle Size Distributions of Particulate Emissions from the Ferroalloy Industry Evaluated by Electrical Low Pressure Impactor (ELPI)

    PubMed Central

    Kero, Ida; Naess, Mari K.; Tranell, Gabriella

    2015-01-01

    The present article presents a comprehensive evaluation of the potential use of an Electrical Low Pressure Impactor (ELPI) in the ferroalloy industry with respect to indoor air quality and fugitive emission control. The ELPI was used to assess particulate emission properties, particularly of the fine particles (Dp ≤ 1 μm), which in turn may enable more satisfactory risk assessments for the indoor working conditions in the ferroalloy industry. An ELPI has been applied to characterize the fume in two different ferroalloy plants, one producing silicomanganese (SiMn) alloys and one producing ferrosilicon (FeSi) alloys. The impactor classifies the particles according to their aerodynamic diameter and gives real-time particle size distributions (PSD). The PSD based on both number and mass concentrations are shown and compared. Collected particles have also been analyzed by transmission and scanning electron microscopy with energy dispersive spectroscopy. From the ELPI classification, particle size distributions in the range 7 nm – 10 μm have been established for industrial SiMn and FeSi fumes. Due to the extremely low masses of the ultrafine particles, the number and mass concentration PSD are significantly different. The average aerodynamic diameters for the FeSi and the SiMn fume particles were 0.17 and 0.10 μm, respectively. Based on this work, the ELPI is identified as a valuable tool for the evaluation of airborne particulate matter in the indoor air of metallurgical production sites. The method is well suited for real-time assessment of morphology (particle shape), particle size, and particle size distribution of aerosols. PMID:25380385

  10. Particle size distributions of particulate emissions from the ferroalloy industry evaluated by electrical low pressure impactor (ELPI).

    PubMed

    Kero, Ida; Naess, Mari K; Tranell, Gabriella

    2015-01-01

    The present article presents a comprehensive evaluation of the potential use of an Electrical Low Pressure Impactor (ELPI) in the ferroalloy industry with respect to indoor air quality and fugitive emission control. The ELPI was used to assess particulate emission properties, particularly of the fine particles (Dp ≤ 1 μm), which in turn may enable more satisfactory risk assessments for the indoor working conditions in the ferroalloy industry. An ELPI has been applied to characterize the fume in two different ferroalloy plants, one producing silicomanganese (SiMn) alloys and one producing ferrosilicon (FeSi) alloys. The impactor classifies the particles according to their aerodynamic diameter and gives real-time particle size distributions (PSD). The PSD based on both number and mass concentrations are shown and compared. Collected particles have also been analyzed by transmission and scanning electron microscopy with energy dispersive spectroscopy. From the ELPI classification, particle size distributions in the range 7 nm - 10 μm have been established for industrial SiMn and FeSi fumes. Due to the extremely low masses of the ultrafine particles, the number and mass concentration PSD are significantly different. The average aerodynamic diameters for the FeSi and the SiMn fume particles were 0.17 and 0.10 μm, respectively. Based on this work, the ELPI is identified as a valuable tool for the evaluation of airborne particulate matter in the indoor air of metallurgical production sites. The method is well suited for real-time assessment of morphology (particle shape), particle size, and particle size distribution of aerosols.

  11. The comparison of fluid dynamics parameters in an Andersen cascade impactor equipped with and without a preseparator.

    PubMed

    Dechraksa, Janwit; Suwandecha, Tan; Maliwan, Kittinan; Srichana, Teerapol

    2014-06-01

    The fluid dynamic data in Andersen cascade impactor (ACI) are still lacking. Airflows and those affected parameters can be predicted in a preseparator and Andersen cascade impactor (ACI) by computational modeling. This study developed a validated computational fluid dynamic (CFD) model of an ACI and investigated the effects of the preseparator on the CFD parameters. Validation of the computational nozzle velocity for each of the stage 0 to stage 5 of the ACI stages was found to be within a 3.56% error. The flow field indicated that the preseparator accelerated the airflow velocity at the induction tube from 1.13 to 3.71 ± 0.09 m/s and 2.40 to 8.68 ± 0.16 m/s (at 28.3 and 60 L/min of flow rate, respectively). The preseparator produced a nozzle's wall shear stress ranged from 0.08 to 0.34 Pa on a collection plate, while the ex-preseparator spread wall shear from the plate's center was in a range of 0.11 to 0.37 Pa (at 28.3 L/min of flow rate). Moreover, the nozzle velocities increased along the distance from the middle of the collection plate to the periphery. The CFD explained the airflow of the preseparator equipped model by accelerating the airflow along the inlet port to maximize the trapping of desirable particles and the generation of a smooth wall shear stress at the collection plate to reduce the particle re-entrainment. While, the ex-preseparator generated an airflow that resulted in a higher wall shear stress occurring on the lower stages.

  12. Semi-continuous sampling of health relevant atmospheric particle subfractions for chemical speciation using a rotating drum impactor in series with sequential filter sampler.

    PubMed

    Li, Fengxia; Schnelle-Kreis, Jürgen; Karg, Erwin; Cyrys, Josef; Gu, Jianwei; Orasche, Jürgen; Abbaszade, Gülcin; Peters, Annette; Zimmermann, Ralf

    2016-04-01

    To achieve unattended continuous long-term (eg., 1 week) sampling of size-segregated 24-h ambient particulate matter (PM), a sampling strategy of a modified 3-stage rotating drum impactor (RDI) in series with a sequential filter sampler was introduced and verified in a field campaign. Before the field sampling, lab experiment was conducted to test the collection efficiency of the third stage of the RDI using the quartz-fiber filter (QFF) as the substrate. The measured value is 0.36 μm, which is larger than the nominal value 0.1 μm. A fast direct analysis of organic species in all size fractions (<0.36, 0.36-1, 1-2.4, and 2.4-10 μm) of 24-h ambient samples was done using in situ derivatization thermal desorption gas chromatography time-of-flight mass spectrometry (IDTD-GC-TOFMS). A few secondary originated polar markers (dicarboxylic acids, cis-pinonic acid, etc.) were introduced and evaluated using this method for the first time and quantified simultaneously with polycyclic aromatic hydrocarbons (PAH) in the filter samples (<0.36 μm). For the other RDI strip samples (0.36-1, 1-2.4, and 2.4-10 μm), PAH and levoglucosan were quantified. The comparability of two such sampler sets was verified with respect to the PM collection profile of the two RDIs as well as measured concentration of chemical compounds in each sampled size fraction, so that a future epidemiological study on the relationship between the finest PM/its chemical composition and health outcome could be carried out through parallel sampling at two sites. The internal correlations between the size-segregated organic compounds are discussed. Besides, the correlations between the size-segregated organic species and size-segregated particulate number concentration (PNC) as well as meteorological parameter are discussed as well.

  13. COMPARISON OF LIGHT SCATTERING DEVICES AND IMPACTORS FOR PARTICULATE MEASUREMENTS IN INDOOR, OUTDOOR, AND PERSONAL ENVIRONMENTS. (R827355C003)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. Aerosol Mass Closure Based On Particle Size Distribution and Aerosol Size Segregated Chemistry Measurements At Mte Cimone (i) (minatroc Project)

    NASA Astrophysics Data System (ADS)

    Putaud, J. P.; van Dingenen, R.; Raes, F.; Facchini, M. C.; Fuzzi, S.; Matta, E.; Decesari, S.

    The MINATROC project is aimed at quantifying the impact of mineral dust on tro- pospheric photochemical cycles and the specific direct effect of secondary aerosol in the presence of mineral dust. This requires a full knowledge of the aerosol physical and chemical properties. During the first MINATROC field experiment (01/06/00- 04/07/00, Mte Cimone, 4411'N, 1042'E, 2165 a.s.l.), a full physical and chemical characterization was performed. A differential mobility particle sizer (DMPS) and an optical particle counter (OPC) were used to monitor the aerosol size distribution in the particle diameter range 6nm - 10 µm. Size segregated aerosol mass distribu- tion and chemical composition were determined from 12hr-integrated 5-stage Berner impactor samples. Gravimetric measurements in dry conditions (RH<20%), ion chro- matography, and a multi-step flash heating thermal method were used to determine aerosol mass, ionic and carbonaceous contents, respectively. Size-segregated aerosol dust content was estimated based on non sea salt calcium concentrations. Sub-micron aerosol ionic composition was also continuously measured using a sampling artifact free wet aerosol denuder - steam jet aerosol collector (WAD-SJAC) combination. The comparison between ammonium nitrate concentrations calculated from the impactor and WAD-SJAC measurements indicate that no significant loss of semi-volatile partic- ulate matter occurred in the impactor. Uncertainties associated with the various mea- surements were assessed. Aerosol mass concentrations derived from chemical analy- sis, and gravimetric and size distribution measurements generally agreed within ex- perimental uncertainties. This indicates that we were able to accurately describe the aerosol chemical composition. The period during which desert dust was observed will be particularly discussed. Variations in the aerosol chemical composition according to various air mass circulation patterns will also be compared to variations in ozone

  15. Predictive Algorithm For Aiming An Antenna

    NASA Technical Reports Server (NTRS)

    Gawronski, Wodek K.

    1993-01-01

    Method of computing control signals to aim antenna based on predictive control-and-estimation algorithm that takes advantage of control inputs. Conceived for controlling antenna in tracking spacecraft and celestial objects, near-future trajectories of which are known. Also useful in enhancing aiming performances of other antennas and instruments that track objects that move along fairly well known paths.

  16. Take AIM and Keep Your Students Engaged

    ERIC Educational Resources Information Center

    Nash, Catherine

    2014-01-01

    This paper outlines the benefits to distance education teachers of formatting a weekly online newsletter in accordance with motivational learning theory. It reflects on the delivery of weekly AIM newsletters to undergraduate economics students at the Open Polytechnic of New Zealand via Moodle. The acronym, AIM, stands for Academic content,…

  17. Aims in Music Education: A Conceptual Study.

    ERIC Educational Resources Information Center

    Koopman, Constantijn

    1997-01-01

    Explores the concept of aims in music education through investigating the ideas of four philosophers: Wolfgang Brezinka, Richard S. Peters, Bennett Reimer, and David Elliott. Inquires into the empirical and logical aspects of aims and clarifies the relationships between "musical behaviors." Concludes by discussing the relevance of conceptual…

  18. Is "Freedom" an Aim of Education?

    ERIC Educational Resources Information Center

    Abinum, Joseph

    1979-01-01

    The purpose of this paper is to show that "freedom" properly understood cannot be an aim or an ideal of education, and that when educators talk of "freedom" as an aim or ideal of education, they usually have in mind the development of autonomy. (Author)

  19. Aims of education in South Africa

    NASA Astrophysics Data System (ADS)

    Morrow, Walter Eugene

    1990-06-01

    The first part of this paper gives a historical account of the aims of education under Apartheid, and discusses the ideological success of Apartheid education. The second part argues that a significant discussion — that is one which could have some purchase on schooling policy and educational practice — of aims of education in South Africa is not possible at present because the historical preconditions for such a discussion are not satisfied. It is argued that Apartheid has generated a political perspective which is unsympathetic to a discussion of aims of education; that the dominance of a social engineering model of schooling distorts a discussion of aims of education; and that a shared moral discourse, which is a necessary condition for a significant discussion of aims of education, does not yet exist in South Africa.

  20. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In Building 1555 at North Vandenberg Air Force Base, workers lower the AIM spacecraft onto a moveable base. AIM will be moved into an area where a partial deployment of the solar arrays on the spacecraft will take place.The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  1. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In Building 1555 at North Vandenberg Air Force Base, workers get ready to attach the overhead crane to the AIM spacecraft. AIM will be moved into an area where a partial deployment of the solar arrays on the spacecraft will take place. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  2. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    Inside the clean-room "tent" of Building 1555 at North Vandenberg Air Force Base, two of the solar array panels on the AIM spacecraft are deployed for testing. Inside are the instruments that will study polar mesospheric clouds located at the edge of space. The AIM spacecraft will fly three instruments designed to study those clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  3. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In a clean-room environment at North Vandenberg Air Force Base, a technician prepares the lights for illumination testing of the AIM spacecraft at left. The AIM spacecraft will fly three instruments designed to study those clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  4. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    Inside the clean-room "tent" of Building 1555 at North Vandenberg Air Force Base, technicians in bunny suits prepare for the solar array deployment on the AIM spacecraft. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  5. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    Inside the clean-room "tent" of Building 1555 at North Vandenberg Air Force Base, a technician places a star tracker cover on the AIM spacecraft during testing of the solar array panel deployment. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  6. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-17

    In a clean-room environment at North Vandenberg Air Force Base, technicians remove covers from instruments in the AIM spacecraft while solar panels are partially deployed. AIM will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  7. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In a clean-room environment at North Vandenberg Air Force Base, a technician begins the illumination testing of the AIM spacecraft at left. The AIM spacecraft will fly three instruments designed to study those clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  8. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    Inside the clean-room "tent" of Building 1555 at North Vandenberg Air Force Base, technicians place a star tracker cover on the AIM spacecraft during testing of the solar array panel deployment. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  9. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-17

    In a clean-room environment at North Vandenberg Air Force Base, technicians look at an area of the AIM spacecraft. AIM will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  10. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    Inside the clean-room "tent" of Building 1555 at North Vandenberg Air Force Base, a star tracker cover is ready for placement on the AIM spacecraft during testing of the solar array panel deployment. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  11. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In Building 1555 at North Vandenberg Air Force Base, workers prepare the area where a partial deployment of the solar arrays on the AIM spacecraft will take place. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  12. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-17

    In a clean-room environment at North Vandenberg Air Force Base, technicians remove covers from instruments in the AIM spacecraft while solar panels are partially deployed. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  13. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-17

    In a clean-room environment at North Vandenberg Air Force Base, technicians work on the AIM spacecraft. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  14. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In a clean-room environment at North Vandenberg Air Force Base, a technician monitors the AIM spacecraft after illumination testing on the spacecraft's solar array panels. The AIM spacecraft will fly three instruments designed to study those clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  15. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In a clean-room environment at North Vandenberg Air Force Base, lights are reflected on the solar array panels of the AIM spacecraft during illumination testing. The AIM spacecraft will fly three instruments designed to study those clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  16. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In Building 1555 at North Vandenberg Air Force Base, workers roll the AIM spacecraft into the "tent" where a partial deployment of the solar arrays on the spacecraft will take place. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  17. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-17

    In a clean-room environment at North Vandenberg Air Force Base, technicians look at part of the AIM spacecraft. AIM will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  18. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In Building 1555 at North Vandenberg Air Force Base, workers lift the AIM spacecraft from its stand in order to move it into an area where a partial deployment of the solar arrays on the spacecraft will take place. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  19. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-16

    In a clean-room environment containing the AIM spacecraft (background) at North Vandenberg Air Force Base, a technician studies results of illumination testing on the spacecraft's solar array panels. The AIM spacecraft will fly three instruments designed to study those clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  20. Animated View of the AIM Mission

    NASA Image and Video Library

    The Aeronomy of Ice in the Mesosphere (AIM) mission will provide the first detailed exploration of Earth's unique and elusive noctilucent or night shining clouds that are found literally on the "ed...

  1. Laser Transmitter Aims At Laser Beacon

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Lesh, James R.

    1993-01-01

    Transmitter part of developmental optical communication system. Compact, lightweight, partially-self-aiming laser transmitter built to verify some capabilities of developmental free-space optical communication system. Design capable of providing 0.5 Mbps data return over range equal to Moon-Earth distance. Breadboard of transmitting terminal constructed and tested in laboratory. Prototype transmitter includes receiving circuitry that keeps it aimed at beacon, once brought into initial alignment within about 1.7 degrees of line of sight to beacon.

  2. Laser Transmitter Aims At Laser Beacon

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Lesh, James R.

    1993-01-01

    Transmitter part of developmental optical communication system. Compact, lightweight, partially-self-aiming laser transmitter built to verify some capabilities of developmental free-space optical communication system. Design capable of providing 0.5 Mbps data return over range equal to Moon-Earth distance. Breadboard of transmitting terminal constructed and tested in laboratory. Prototype transmitter includes receiving circuitry that keeps it aimed at beacon, once brought into initial alignment within about 1.7 degrees of line of sight to beacon.

  3. Development and characterization of an ice-selecting pumped counterflow virtual impactor (IS-PCVI) to study ice crystal residuals

    NASA Astrophysics Data System (ADS)

    Hiranuma, Naruki; Möhler, Ottmar; Kulkarni, Gourihar; Schnaiter, Martin; Vogt, Steffen; Vochezer, Paul; Järvinen, Emma; Wagner, Robert; Bell, David M.; Wilson, Jacqueline; Zelenyuk, Alla; Cziczo, Daniel J.

    2016-08-01

    Separation of particles that play a role in cloud activation and ice nucleation from interstitial aerosols has become necessary to further understand aerosol-cloud interactions. The pumped counterflow virtual impactor (PCVI), which uses a vacuum pump to accelerate the particles and increase their momentum, provides an accessible option for dynamic and inertial separation of cloud elements. However, the use of a traditional PCVI to extract large cloud hydrometeors is difficult mainly due to its small cut-size diameters (< 5 µm). Here, for the first time we describe a development of an ice-selecting PCVI (IS-PCVI) to separate ice in controlled mixed-phase cloud system based on the particle inertia with the cut-off diameter ≥ 10 µm. We also present its laboratory application demonstrating the use of the impactor under a wide range of temperature and humidity conditions. The computational fluid dynamics simulations were initially carried out to guide the design of the IS-PCVI. After fabrication, a series of validation laboratory experiments were performed coupled with the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) expansion cloud simulation chamber. In the AIDA chamber, test aerosol particles were exposed to the ice supersaturation conditions (i.e., RHice > 100 %), where a mixture of droplets and ice crystals was formed during the expansion experiment. In parallel, the flow conditions of the IS-PCVI were actively controlled, such that it separated ice crystals from a mixture of ice crystals and cloud droplets, which were of diameter ≥ 10 µm. These large ice crystals were passed through the heated evaporation section to remove the water content. Afterwards, the residuals were characterized with a suite of online and offline instruments downstream of the IS-PCVI. These results were used to assess the optimized operating parameters of the device in terms of (1) the critical cut-size diameter, (2) the transmission efficiency and (3) the counterflow

  4. Development and characterization of an ice-selecting pumped counterflow virtual impactor (IS-PCVI) to study ice crystal residuals

    SciTech Connect

    Hiranuma, Naruki; Möhler, Ottmar; Kulkarni, Gourihar; Schnaiter, Martin; Vogt, Steffen; Vochezer, Paul; Järvinen, Emma; Wagner, Robert; Bell, David M.; Wilson, Jacqueline; Zelenyuk, Alla; Cziczo, Daniel J.

    2016-01-01

    Separation of particles that play a role in cloud activation and ice nucleation from interstitial aerosols has become necessary to further understand aerosol-cloud interactions. The pumped counterflow virtual impactor (PCVI), which uses a vacuum pump to accelerate the particles and increase their momentum, provides an accessible option for dynamic and inertial separation of cloud elements. However, the use of a traditional PCVI to extract large cloud hydrometeors is difficult mainly due to its small cut-size diameters (< 5 µm). Here, for the first time we describe a development of an ice-selecting PCVI (IS-PCVI) to separate ice in controlled mixed-phase cloud system based on the particle inertia with the cut-off diameter ≥ 10 µm. We also present its laboratory application demonstrating the use of the impactor under a wide range of temperature and humidity conditions. The computational fluid dynamics simulations were initially carried out to guide the design of the IS-PCVI. After fabrication, a series of validation laboratory experiments were performed coupled with the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) expansion cloud simulation chamber. In the AIDA chamber, test aerosol particles were exposed to the ice supersaturation conditions (i.e., RHice > 100 %), where a mixture of droplets and ice crystals was formed during the expansion experiment. In parallel, the flow conditions of the IS-PCVI were actively controlled, such that it separated ice crystals from a mixture of ice crystals and cloud droplets, which were of diameter ≥ 10 µm. These large ice crystals were passed through the heated evaporation section to remove the water content. Afterwards, the residuals were characterized with a suite of online and offline instruments downstream of the IS-PCVI. These results were used to assess the optimized operating parameters of the device in terms of (1) the critical cut-size diameter, (2) the transmission efficiency and (3)

  5. Orbital Sciences Pegasus XL AIM Arrival

    NASA Image and Video Library

    2007-03-10

    NASA's Aeronomy of Ice in the Mesosphere, or AIM, spacecraft arrives in a clean room at Vandenberg Air Force Base in California. AIM is the seventh Small Explorers mission under NASA's Explorer Program. The program provides frequent flight opportunities for world-class scientific investigations from space within heliophysics and astrophysics. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  6. Orbital Sciences Pegasus XL AIM Processing

    NASA Image and Video Library

    2007-03-10

    Inside a clean room at Vandenberg Air Force Base in California, NASA's Aeronomy of Ice in the Mesosphere, or AIM, spacecraft is weighed. AIM is the seventh Small Explorers mission under NASA's Explorer Program. The program provides frequent flight opportunities for world-class scientific investigations from space within heliophysics and astrophysics. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to the Pegasus XL during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  7. An intercomparison of the indoor air sampling impactor and the dichotomous sampler for a 10-. mu. m cut size

    SciTech Connect

    Lioy, P.J.; Wainman, T. ); Turner, W. ); Marple, V.A. )

    1988-05-01

    As a consequence of the promulgation of the PM-10 (particulate matter {<=} 10 {mu}m aerodynamic diameter) standard by the US Environmental Protection Agency, there is increased use of samplers that collect particles within this range. Further, to support future human health and exposure studies on PM-10, it is necessary to develop samplers that can be used in either the indoor or outdoor environment or both. A low flow rate, sharp cut indoor air sampling impactor (IASI) has been constructed with a single impaction plate and size selectively collects PM-10 mass in indoor environments. It is presently being used in the Total Human Environmental Exposure Study (THEES). In an effort to examine the collection characteristics of the IASI, a field intercomparison study was conducted using both the dichotomous sampler and the IASI. The dichotomous sampler has been routinely used to collect PM-10 in the outdoor atmosphere in anticipation of the PM-10 standard. The results of that intercomparison are reported.

  8. Tension strength of a thick graphite/epoxy laminate after impact by a 1/2-in. radius impactor

    NASA Technical Reports Server (NTRS)

    Poe, C. C., Jr.; Illg, W.; Garber, D. P.

    1986-01-01

    NASA is developing graphite/epoxy filament-wound cases for solid rocket motors of the space shuttle. They are wet-wound with AS4W graphite fiber and HBRF-55A epoxy. The membrane region is about 1.4 inches thick. Two 30-inch-diameter by 12-inch-long cylinders were impacted every two inches of circumference with 1/2-inch radius impactors that were dropped from various heights. One cylinder was empty and the other was filled with inert propellant. Two-inch-wide test specimens were cut from the cylinders. Each was centered on an impact site. The specimens were x-rayed and loaded to failure in uniaxial tension. Rigid body mechanics and the Hertz law were used to predict impact force, local deformations, contact diameters, and contact pressures. The depth of impact damage was predicted using Love's solution for pressure applied on part of the boundary of a semi-infinite body. The predictions were reasonably good. The strengths of the impacted specimens were reduced by as much as 37 percent without visible surface damage. Even the radiographs did not reveal the nonvisible damage.

  9. Character as the Aim of Education

    ERIC Educational Resources Information Center

    Shields, David Light

    2011-01-01

    The aim of education should be developing intellectual character, moral character, civic character, and performance character. That does not mean that schools should ignore teaching content, but that the dispositions and habits of mind that come from developing these four forms of character will remain with students throughout their lives.…

  10. Character as the Aim of Education

    ERIC Educational Resources Information Center

    Shields, David Light

    2011-01-01

    The aim of education should be developing intellectual character, moral character, civic character, and performance character. That does not mean that schools should ignore teaching content, but that the dispositions and habits of mind that come from developing these four forms of character will remain with students throughout their lives.…

  11. Teacher Research and the Aims of Education

    ERIC Educational Resources Information Center

    Leeman, Yvonne; Wardekker, Willem

    2014-01-01

    We report on the development of a course for experienced teachers in the Netherlands, intended to enhance their professionalism by engaging them in doing research based on reflection on the aims of their educational efforts. The course was accompanied by design-based research. The research question was whether and how the course stimulated…

  12. AIM: Adventures in Movement for the Handicapped.

    ERIC Educational Resources Information Center

    Adventures In Movement for the Handicapped, Inc., Dayton, OH.

    The handbook on Adventures in Movement for the Handicapped (AIM) gives information about general organizational goals and suggests activities for use by volunteer teachers with blind, deaf, crippled, cerebral palsied, mentally retarded, and autistic children at five ability/age levels. General Information given about each handicap usually includes…

  13. AIM: Ames Imaging Module Spacecraft Camera

    NASA Technical Reports Server (NTRS)

    Thompson, Sarah

    2015-01-01

    The AIM camera is a small, lightweight, low power, low cost imaging system developed at NASA Ames. Though it has imaging capabilities similar to those of $1M plus spacecraft cameras, it does so on a fraction of the mass, power and cost budget.

  14. Pragmatics and the aims of language evolution.

    PubMed

    Scott-Phillips, Thomas C

    2017-02-01

    Pragmatics has historically played a relatively peripheral role in language evolution research. This is a profound mistake. Here I describe how a pragmatic perspective can inform language evolution in the most fundamental way: by making clear what the natural objects of study are, and hence what the aims of the field should be.

  15. Fabrication of graded density impactor via underwater shock wave and quasi-isentropic compression testing at two-stage gas gun facility

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Li, Xiaojie; Hokamoto, Kazuyuki

    2014-12-01

    We show direct evidence that underwater shock wave enables us to bond multithin plates with flat, parallel, and high-strength interfaces, which are key requirements for functionally graded material (also called graded density impactor). This phenomenon is ascribed to the super short duration of the high-speed underwater shock wave, reducing the surface tension, diffusion, evaporation, deposition, and viscous flow of matter. Thin magnesium, aluminum, titanium, copper, and molybdenum foils were welded together and designed with the increase in density. Experimental evidence and numerical simulation show that well bonding between the multilayer structures. Microstructure examinations reveal that the dominant interfacial form shifts from waviness to linearity. Graded density impactor with multilayer structure is proved that can produce quasi-isentropic compression in two-stage gas gun experiment with a designed pressure loading profile, which suggests a feasible method to simulate the conditions we want to study that were previously inaccessible in a precisely controlled laboratory environment.

  16. Electric Solar Wind Sail Kinetic Energy Impactor for Asteroid Deflection Missions

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Kouhei; Yamakawa, Hiroshi

    2016-03-01

    An electric solar wind sail uses the natural solar wind stream to produce low but continuous thrust by interacting with a number of long thin charged tethers. It allows a spacecraft to generate a thrust without consuming any reaction mass. The aim of this paper is to investigate the use of a spacecraft with such a propulsion system to deflect an asteroid with a high relative velocity away from an Earth collision trajectory. To this end, we formulate a simulation model for the electric solar wind sail. By summing thrust vectors exerted on each tether, a dynamic model which gives the relation between the thrust and sail attitude is proposed. Orbital maneuvering by fixing the sail's attitude and changing tether voltage is considered. A detailed study of the deflection of fictional asteroids, which are assumed to be identified 15 years before Earth impact, is also presented. Assuming a spacecraft characteristic acceleration of 0.5 mm/s 2, and a projectile mass of 1,000 kg, we show that the trajectory of asteroids with one million tons can be changed enough to avoid a collision with the Earth. Finally, the effectiveness of using this method of propulsion in an asteroid deflection mission is evaluated in comparison with using flat photonic solar sails.

  17. Advanced Industrial Materials (AIM) fellowship program

    SciTech Connect

    McCleary, D.D.

    1997-04-01

    The Advanced Industrial Materials (AIM) Program administers a Graduate Fellowship Program focused toward helping students who are currently under represented in the nation`s pool of scientists and engineers, enter and complete advanced degree programs. The objectives of the program are to: (1) establish and maintain cooperative linkages between DOE and professors at universities with graduate programs leading toward degrees or with degree options in Materials Science, Materials Engineering, Metallurgical Engineering, and Ceramic Engineering, the disciplines most closely related to the AIM Program at Oak Ridge National Laboratory (ORNL); (2) strengthen the capabilities and increase the level of participation of currently under represented groups in master`s degree programs, and (3) offer graduate students an opportunity for practical research experience related to their thesis topic through the three-month research assignment or practicum at ORNL. The program is administered by the Oak Ridge Institute for Science and Education (ORISE).

  18. CURRICULUM MATTERS: Aims assessments and workplace needs

    NASA Astrophysics Data System (ADS)

    Black, Paul

    1997-09-01

    This paper attempts to consider the aims that undergraduate physics degree courses actually reflect and serve in the light of the employment patterns of graduates and of the expressed needs of employers. It reviews the results of analyses of what degree examinations actually test, and goes on to quote criticisms of their courses and radical proposals to change them adopted by the UK conference of physics professors. The discussion is then broadened by discussion of evidence, about the employment of graduates and about the priorities that some industrialists now give in the qualities that they look for when recruiting new graduates. The evidence leads to a view that radical changes are needed, both in courses and examinations, and that there is a need for university departments to work more closely with employers in re-formulating the aims and priorities in their teaching.

  19. Tapping, grasping and aiming in ideomotor apraxia.

    PubMed

    Ietswaart, Magdalena; Carey, David P; Della Sala, Sergio

    2006-01-01

    Very few studies have investigated sensorimotor control in apraxia using tasks that differ in movement complexity. Nevertheless, there is some evidence to suggest that spontaneous behaviour, although relatively preserved, can be rather clumsy or awkward, and that patients with ideomotor apraxia may have subtle kinematic abnormalities in movements made in the laboratory. It remains unclear whether patients with ideomotor apraxia perform normally on movements such as visually guided aiming, that may not depend on higher-order, more cognitive, processes and that are relatively unguided by overlearned contexts. In this study, three different sensorimotor tasks were given to the same sample of patients with quantified apraxic disturbance. Finger tapping, goal-directed grasping and aiming with and without visual feedback were examined in these patients. A clear dissociation was found between grossly impaired gesture imitation and intact motor programming of goal-directed movements with visual feedback. Apraxic patients were, however, impaired on aiming movements without visual feedback, suggesting that apraxia is associated with an increased reliance on integration of online visual information with feedforward/feedback somatosensory and motor signals. Furthermore, patients were impaired on single finger tapping which was a surprisingly good predictor of apraxia severity.

  20. Laboratory and field evaluation of crystallized DOW 704 oil on the performance of the Well Impactor Ninety-Six fFine particulate matter fractionator.

    PubMed

    Vanderpool, Robert W; Byrd, Lee A; Wiener, Russell W; Hunike, Elizabeth T; Labickas, Michael; Leston, Alan R; Tolocka, Michael P; McElroy, Frank F; Murdoch, Robert W; Natarajan, Sanjay; Noble, Christopher A; Peters, Thomas M

    2007-01-01

    Subsequent to the 1997 promulgation of the Federal Reference Method (FRM) for monitoring fine particulate matter (PM2.5) in ambient air, U.S. Environmental Protection Agency (EPA) received reports that the DOW 704 diffusion oil used in the method's Well Impactor Ninety-Six (WINS) fractionator would occasionally crystallize during field use, particularly under wintertime conditions. Although the frequency of occurrence on a nationwide basis was low, uncertainties existed as to whether crystallization of the DOW 704 oil may adversely affect a sampling event's data quality. In response to these concerns, EPA and the State of Connecticut Department of Environmental Protection jointly conducted a series of specialized tests to determine whether crystallized oil adversely affected the performance of the WINS fractionator. In the laboratory, an experimental setup used dry ice to artificially induce crystallization of the diffusion oil under controlled conditions. Using primary polystyrene latex calibration aerosols, standard size-selective performance tests of the WINS fractionator showed that neither the position nor the shape of the WINS particle size fractionation curve was substantially influenced by the crystallization of the DOW 704 oil. No large particle bounce from the crystallized impaction surface was observed. During wintertime field tests, crystallization of the DOW 704 oil did not adversely affect measured PM2.5 concentrations. Regression of measurements with crystallized DOW 704 versus liquid dioctyl sebacate (DOS) oil produced slope, intercept, and R2 values of 0.98, 0.1, and 0.997 microg/m3, respectively. Additional field tests validated the use of DOS as an effective impaction substrate. As a result of these laboratory and field tests, DOS oil has been approved by EPA as a substitute for DOW 704 oil. Since the field deployment of DOS oil in 2001, users of this alternative oil have not reported any operational problems associated with its use in the PM2

  1. The aim and philosophy of patient monitoring

    PubMed Central

    Stewart, J. S. S.

    1970-01-01

    The history of monitoring is traced from ancient times until the invention of transducers and computers. The relevance of progress in resuscitation is emphasized. The more recent evolution of electromedical apparatus is considered from single signal detection, display and alarm to multiple signal processing, trend analysis and diagnosis. The aim of patient monitoring is to give warning of early or dangerous deterioration and to achieve this by obtaining an optimal compromise involving many design factors, clinical, engineering and economic. A new philosophy is illustrated by the specification and development of the Lifeline patient monitor. The translation of clinical diagnoses into electronic switching logic is of particular importance. PMID:4920275

  2. AIMS: Asteroseismic Inference on a Massive Scale

    NASA Astrophysics Data System (ADS)

    Reese, Daniel R.

    2016-11-01

    AIMS (Asteroseismic Inference on a Massive Scale) estimates stellar parameters and credible intervals/error bars in a Bayesian manner from a set of seismic frequency data and so-called classic constraints. To achieve reliable parameter estimates and computational efficiency it searches through a grid of pre-computed models using an MCMC algorithm; interpolation within the grid of models is performed by first tessellating the grid using a Delaunay triangulation and then doing a linear barycentric interpolation on matching simplexes. Inputs for the modeling consists of individual frequencies from peak-bagging, which can be complemented with classic spectroscopic constraints.

  3. Taking Aim at AYP Called Timely, Risky

    ERIC Educational Resources Information Center

    Klein, Alyson

    2010-01-01

    The Obama administration's proposal to revamp the signature yardstick used to measure schools' progress under the Elementary and Secondary Education Act (ESEA) is being seen as a bold step toward revising a key feature of the law, even as questions loom about how a new system would work. Under the plan, adequate yearly progress (AYP)--the…

  4. AIM cryocooler developments for HOT detectors

    NASA Astrophysics Data System (ADS)

    Rühlich, I.; Mai, M.; Withopf, A.; Rosenhagen, C.

    2014-06-01

    Significantly increased FPA temperatures for both Mid Wave and Long Wave IR detectors, i.e. HOT detectors, which have been developed in recent years are now leaving the development phase and are entering real application. HOT detectors allowing to push size weight and power (SWaP) of Integrated Detectors Cooler Assemblies (IDCA's) to a new level. Key component mainly driving achievable weight, volume and power consumption is the cryocooler. AIM cryocooler developments are focused on compact, lightweight linear cryocoolers driven by compact and high efficient digital cooler drive electronics (DCE) to also achieve highest MTTF targets. This technology is using moving magnet driving mechanisms and dual or single piston compressors. Whereas SX030 which was presented at SPIE in 2012 consuming less 3 WDC to operate a typical IDCA at 140K, next smaller cooler SX020 is designed to provide sufficient cooling power at detector temperature above 160K. The cooler weight of less than 200g and a total compressor length of 60mm makes it an ideal solution for all applications with limited weight and power budget, like in handheld applications. For operating a typical 640x512, 15μm MW IR detector the power consumption will be less than 1.5WDC. MTTF for the cooler will be in excess of 30,000h and thus achieving low maintenance cost also in 24/7 applications. The SX020 compressor is based on a single piston design with integrated passive balancer in a new design achieves very low exported vibration in the order of 100mN in the compressor axis. AIM is using a modular approach, allowing the chose between 5 different compressor types for one common Stirling expander. The 6mm expander with a total length of 74mm is now available in a new design that fits into standard dewar bores originally designed for rotary coolers. Also available is a 9mm coldfinger in both versions. In development is an ultra-short expander with around 35mm total length to achieve highest compactness. Technical

  5. Work, the Aims of Life and the Aims of Education: A Reply to Clarke and Mearman

    ERIC Educational Resources Information Center

    Winch, Christopher

    2004-01-01

    The main points made by Clarke and Mearman about Winch's article, 'The Economic Aims of Education,' are taken up and discussed. My argument is that work is not necessarily a disutility, although paid employment can be when it is undertaken in conditions that are not fulfilling. Life aims are not the same as educational aims, although educational…

  6. Work, the Aims of Life and the Aims of Education: A Reply to Clarke and Mearman

    ERIC Educational Resources Information Center

    Winch, Christopher

    2004-01-01

    The main points made by Clarke and Mearman about Winch's article, 'The Economic Aims of Education,' are taken up and discussed. My argument is that work is not necessarily a disutility, although paid employment can be when it is undertaken in conditions that are not fulfilling. Life aims are not the same as educational aims, although educational…

  7. Degree of impactor fragmentation under collision with a regolith surface—Laboratory impact experiments of rock projectiles

    NASA Astrophysics Data System (ADS)

    Nagaoka, Hiroki; Takasawa, Susumu; Nakamura, Akiko M.; Sangen, Kazuyoshi

    2014-01-01

    Some meteorites consist of a mix of components of various parent bodies that were presumably brought together by past collisions. Impact experiments have been performed to investigate the degree of target fragmentation during such collisions. However, much less attention has been paid to the fate of the impactors. Here, we report the results of our study of the empirical relationship between the degree of projectile fragmentation and the impact conditions. Millimeter-sized pyrophyllite and basalt projectiles were impacted onto regolith-like sand targets and an aluminum target at velocities of up to 960 m s-1. Experiments using millimeter-sized pyrophyllite blocks as targets were also conducted to fill the gap between this study and the previous studies of centimeter-sized rock targets. The catastrophic disruption threshold for a projectile is defined as the energy density at which the mass of the largest fragment is the half of the original mass. The thresholds with the sand target were 4.5 ± 1.1 × 104 and 9.0 ± 1.9 × 104 J kg-1, for pyrophyllite and basalt projectiles, respectively. These values are two orders of magnitude larger than the threshold for impacts between pyrophyllite projectiles onto aluminum targets, but are qualitatively consistent with the fact that the compressive and tensile strengths of basalt are larger than those of pyrophyllite. The threshold for pyrophyllite projectiles and the aluminum target agrees with the threshold for aluminum projectiles and pyrophyllite targets within the margin of error. Consistent with a previous result, the threshold depended on the size of the rocks with a power of approximately -0.4 (Housen and Holsapple 1999). Destruction of rock projectiles occurred when the peak pressure was about ten times the tensile strength of the rocks.

  8. Asteroid Retrieval Mission Concept - Trailblazing Our Future in Space and Helping to Protect Us from Earth Impactors

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Brohpy, John R.; Merrill, Raymond G.

    2013-01-01

    The Asteroid Retrieval Mission (ARM) is a robotic mission concept with the goal of returning a small (7 m diameter) near-Earth asteroid (NEA), or part of a large NEA, to a safe, stable orbit in cislunar space using a 50 kW-class solar electric propulsion (SEP) robotic spacecraft (40 kW available to the electric propulsion system) and currently available technologies. The mass of the asteroidal material returned from this mission is anticipated to be up to 1,000 metric tons, depending on the orbit of the target NEA and the thrust-to-weight and control authority of the SEP spacecraft. Even larger masses could be returned in the future as technological capability and operational experience improve. The use of high-power solar electric propulsion is the key enabling technology for this mission concept, and is beneficial or enabling for a variety of space missions and architectures where high-efficiency, low-thrust transfers are applicable. Many of the ARM operations and technologies could also be applicable to, or help inform, planetary defense efforts. These include the operational approaches and systems associated with the NEA approach, rendezvous, and station-keeping mission phases utilizing a low-thrust, high-power SEP spacecraft, along with interacting with, capturing, maneuvering, and processing the massive amounts of material associated with this mission. Additionally, the processed materials themselves (e.g., high-specific impulse chemical propellants) could potentially be used for planetary defense efforts. Finally, a ubiquitous asteroid retrieval and resource extraction infrastructure could provide the foundation of an on call planetary defense system, where a SEP fleet capable of propelling large masses could deliver payloads to deflect or disrupt a confirmed impactor in an efficient and timely manner.

  9. Forming the Flora Family: Implications for the Near-Earth Asteroid Population and Large Terrestrial Planet Impactors

    NASA Astrophysics Data System (ADS)

    Vokrouhlický, David; Bottke, William F.; Nesvorný, David

    2017-04-01

    Formed from a catastrophic collision of a parent body larger than 150 km in diameter, the Flora family is located in the innermost part of the main belt near the {ν }6 secular resonance. Objects in this region, when pushed onto planet-crossing orbits, tend to have relatively high probabilities of striking the Earth. These factors suggest that Flora may be a primary source of present-day LL chondrite-like NEOs and Earth/Moon impactors. To investigate this possibility, we used collisional and dynamical models to track the evolution of Flora family members. We created an initial Flora family and followed test asteroids 1 and 3 km in diameter using a numerical code that accounted for both planetary perturbations and nongravitational effects. Our Flora family members reproduce the observed semimajor axis, eccentricity, and inclination distributions of the real family after ≃ 1 to 1.4 Gyr. A consistency with the surface age inferred from crater spatial densities found on (951) Gaspra may favor the latter age. Our combined collisional and dynamical runs indicate that the family has lost nearly 90% of its initial kilometer-sized members. At its peak, 100{--}300 {Myr} after the family-forming event, Flora family members filled NEO space with nearly 1000 D≥slant 1 {km} size bodies before fading to its present contribution of 35-50 such NEOs. Therefore, it is not currently a major source of large NEOs. We also find 700-950 and 35-47 kilometer-sized asteroids struck the Earth and Moon, respectively, most within the first 300 Myr after family formation. These results imply that Flora played a major role in providing impacts to the mid-Proterozoic Earth.

  10. High volume air sampler for environmental nanoparticles using a sharp-cut inertial filter combined with an impactor

    NASA Astrophysics Data System (ADS)

    Zhang, Tong; Zhao, Tianren; Takahashi, Hideaki; Hata, Mitsuhiko; Toriba, Akira; Ikeda, Takuji; Otani, Yoshio; Furuuchi, Masami

    2017-02-01

    A multi-nozzle layered mesh inertial filter, developed by the authors based on inertial filter technology for separating ultrafine particles (UFPs) at a moderate pressure drop, was investigated in an attempt to improve the steepness of the separation efficiency curve by combining an inertial filter and an impactor. In this system, the separation curves overlap each other, while maintaining about a 100 nm difference in cutoff size d p50. Such a combination, which we refer to as a ‘hybrid inertial filter’, was validated for a single nozzle geometry. Using a multi nozzle geometry, it was scaled up to a high volume air sampling flow rate of 400 l min-1 at a pressure drop of  <15 kPa. An air sampling unit designed for a commercial portable high volume air sampler, consisting of a multi-cyclone (d p50  =  1 µm) and a hybrid inertial filer (d p50  =  130 nm), was devised and its performance was compared with that for conventional air samplers. The scaled up version of the hybrid inertial filter using multi-nozzle geometry was confirmed. The features of the hybrid inertial filter included the suppression of the bouncing of particles with sizes  >300 nm, a steeper collection efficiency curve and less pressure drop than those of a previous type of inertial filter. The ambient PM0.13 evaluated for the present unit was found to be in good agreement with values obtained for 2 different types of cascade air samplers.

  11. Method for measuring the size distribution of airborne rhinovirus

    SciTech Connect

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor.

  12. Insect food aiming at Mars emigration

    NASA Astrophysics Data System (ADS)

    Katayama, Naomi; Yamashita, Masamichi; Hashimoto, Hirofumi; Nagasaka, Sanako; Kuwayama, Akemi; Sofue, Megumi

    2012-07-01

    We study insect food aiming at Mars emigration.In space agriculture, insect is the important creature which we cannot miss.It is necessary for the pollination of the plant, and it is rich to protein and lipid as food.I reported that silkworm is an insect necessary for astroponics in particular last time.We make clothes using silk thread, and the pupa becomes the food.In addition, the clothes can make food as protein when we need not to use it. The bee is a very important insect in the space agriculture,too.We examined nutrition of silkworm, bee, grasshopper, snail and the white ant which are necessary for Mars emigration.We will introduce of good balance space foods.We will report many meal menu for Mars emigration.

  13. The aims and accomplishments of comparative psychology.

    PubMed

    Lickliter, Robert

    2004-01-01

    Greenberg, Partridge, Weiss, and Pisula propose a new perspective of comparative psychology, based in large part on an anagenetic and dynamic systems approach to the development and evolution of behavior. Their view appreciates the probabilistic nature of behavioral development and promotes the value of an integrative levels concept for generating testable hypothesis regarding the complex relationship between biology, context, and developmental history underlying behavioral and psychological functioning. However, the authors fail to represent the full scope of contemporary comparative psychology by overlooking several core aims of the field, including (a) the use of animal models to shed light on human behavior and development and (b) understanding the role of behavior as a leading edge in the evolutionary process.

  14. Research effort aims at floating production technology

    SciTech Connect

    Not Available

    1992-08-17

    This paper reports that a 3 year research and development program on floating production systems (FPS), instigated by the Royal Norwegian Council for Scientific and Industrial Research (NTNF), has refined and qualified technologies for North Sea and arctic conditions. The FPS 2000 program, which cost 58 million kroner ($10 million), concentrated mainly on mooring systems and pipeline technology, along with new system concepts and cost reduction measures. More than 30 projects have been completed within the scheme. The anchoring and positioning project concentrates on developing methods for simulating behavior of mooring systems for large volume structures in deep water. It also seeks ways to determine efficiency of dynamic positioning thrusters under extreme conditions.

  15. Taking aim at novel vaccines market.

    PubMed

    Awasthi, Sita

    2009-10-01

    The World Vaccine Congress Washington 2009 was held in Chantilly, VA USA April 2O -23rd. The Vaccine congress attracted over 400 participants from across the world, including leading vaccine manufacturers, biotechs, governmental agencies, NGOs, research and academic institutes, venture capital and legal firms, contract service and equipment manufacturers. The speakers covered a wide range of topics, including the role of government and regulatory agencies, funding availability, research and development, manufacturing, packaging and post vaccine evaluations. Past vaccine development efforts have historically focused on infectious diseases. With advancements in the field of immunology, molecular biology and vaccinology, the vaccine field has begun moving in new directions. "Taking aim at novel vaccines market" session chaired by Dr. Una Ryan, Chief Executive Officer of Waltham Technologies, was focused on traditional approaches to novel targets (nosocomial infections), novel approaches to traditional targets (flu and rabies), novel approaches to novel targets (Type 1 diabetes, multiple sclerosis and smoking) and vaccines for developing markets (TB, malaria, rabies). The importance of collaborations among academic institutions, industries, and philanthropic foundations for developing markets was also emphasized.

  16. Impactor No More (Animation)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Quick Time Movie for PIA02130 Realtime Ejecta (Animation)

    This movie was taken by Deep Impact's flyby spacecraft shows the flash that occurred when comet Tempel 1 ran over the spacecraft's probe. It was taken by the flyby craft's medium-resolution camera.

  17. ANNULAR IMPACTOR SAMPLING DEVICE

    DOEpatents

    Tait, G.W.C.

    1959-03-31

    A high-rate air sampler capable of sampling alphaemitting particles as small as 0.5 microns is described. The device is a cylindrical shaped cup that fits in front of a suction tube and which has sticky grease coating along its base. Suction forces contaminated air against the periodically monitored particle absorbing grease.

  18. An analytical method coupling accelerated solvent extraction and HPLC-fluorescence for the quantification of particle-bound PAHs in indoor air sampled with a 3-stages cascade impactor.

    PubMed

    Liaud, Céline; Millet, Maurice; Le Calvé, Stéphane

    2015-01-01

    Most of Polycyclic Aromatic Hydrocarbons (PAHs) are associated to airborne particles and their health impact depends on the particle size where they are bound. This work aims to develop a high sensitive analytical technique to quantify particulate PAHs sampled with a 3-stages cascade impactor in order to derive simultaneously their individual concentration in PM1, PM2.5 and PM10. Three key steps of the method were evaluated separately in order to avoid any PAHs loss during the global sample preparation procedure: (1) the accelerated solvent extraction of PAHs from the filter; (2) the primary concentration of the extract until 1 mL by means of a rotary evaporator at 45°C and 220 mbar and (3) the final concentration of the pre-concentrated extract to about 100-150 µL under a gentle nitrogen stream. Each recovery experiment was realized in triplicates. All these steps evaluated independently show that the overall PAHs loss, even for those with a low molecular weight, should not exceed more than a few percent. Extracts were then analyzed by using a HPLC coupled to fluorescence and Diode Array Detectors with the external standard method. The resulting calibration curves containing between 9 and 12 points were plotted in the concentration range of 0.05-45 µg L(-1) for most of the 16 US-EPA priority PAHs and were fully linear (R(2)>0.999). Limits Of Quantification were in the range 0.05-0.47 µg L(-1) corresponding to 0.75-7.05 pg m(-3) for 20 m(3) of pumped air. Finally, taking into account the average PAHs concentrations previously reported in typical European indoor environments, and considering the use of a 3-stages cascade impactor to collect simultaneously PM>10 µm, 2.5 µm

  19. Evidence from Polymict Ureilite Meteorites for a Single "Rubble-Pile" Ureilite Parent Asteroid Gardened by Several Distinct Impactors

    NASA Technical Reports Server (NTRS)

    Downes, Hilary; Mittlefehldt, David W.; Kita, Noriko T.; Valley, John W.

    2008-01-01

    Ureilites are ultramafic achondrite meteorites that have experienced igneous processing whilst retaining heterogeneity in mg# and oxygen isotope ratios. Polymict ureilites represent material derived from the surface of the ureilite parent asteroid(s). Electron microprobe analysis of more than 500 olivine and pyroxene clasts in six polymict ureilites reveals that they cover a statistically identical range of compositions to that shown by all known monomict ureilites. This is considered to be convincing evidence for derivation from a single parent asteroid. Many of the polymict ureilites also contain clasts that have identical compositions to the anomalously high Mn/Mg olivines and pyroxenes from the Hughes 009 monomict ureilite (here termed the Hughes cluster ). Four of the six samples also contain distinctive ferroan lithic clasts that have been derived from oxidized impactors. The presence of several common distinctive lithologies within the polymict ureilites is additional evidence that the ureilites were derived from a single parent asteroid. Olivine in a large lithic clast of augite-bearing ureilitic has an mg# of 97, extending the compositional range of known ureilite material. Our study confirms that ureilitic olivine clasts with mg#s < 85 are much more common than those with mg# > 85, which also show more variable Mn contents, including the melt-inclusion bearing "Hughes cluster" ureilites. We interpret this to indicate that the parent ureilite asteroid was disrupted by a major impact at a time when melt was still present in regions with a bulk mg# > 85, giving rise to the two types of ureilites: common ferroan ones that were already residual after melting and less common magnesian ones that were still partially molten when disruption occurred, some of which are the result of interaction of melts with residual mantle during disruption. A single daughter asteroid re-accreted from the disrupted remnants of the mantle of the proto-ureilite asteroid, giving rise

  20. Student Aims Performance in a Predominately Hispanic District

    ERIC Educational Resources Information Center

    Chebultz, Lance

    2012-01-01

    School districts in the United States have undergone large changes over the last decade to accommodate No Child Left Behind (NCLB). Arizona accommodated NCLB through Arizona's Instrument to Measure Standards (AIMS). Expectations were established for all students, varying by group of students based on grade, special education status, free/reduced…

  1. The effect of nonideal cascade impactor stage collection efficiency curves on the interpretation of the size of inhaler-generated aerosols.

    PubMed

    Roberts, D L; Mitchell, J P

    2013-06-01

    Cascade impactors, operating on the principle of inertial size separation in (ideally) laminar flow, are used to determine aerodynamic particle size distributions (APSDs) of orally inhaled product (OIP) aerosols because aerodynamic diameter can be related to respiratory tract deposition. Each stage is assumed typically to be an ideal size fractionator. Thus, all particles larger than a certain size are considered collected and all finer particles are treated as penetrating to the next stage (a step function stage efficiency curve). In reality, the collection efficiency of a stage smoothly increases with particle size as an "S-shaped" curve, from approximately 0% to 100%. Consequently, in some cases substantial overlap occurs between neighboring stages. The potential for bias associated with the step-function assumption has been explored, taking full resolution and two-stage abbreviated forms of the Andersen eight-stage nonviable impactor (ACI) and the next-generation pharmaceutical impactor (NGI) as example apparatuses. The behavior of unimodal, log-normal APSDs typical of OIP-generated aerosols has been investigated, comparing known input values to calculated values of central tendency (mass median aerodynamic diameter) and spread (geometric standard deviation, GSD). These calculations show that the error introduced by the step change assumption is larger for the ACI than for the NGI. However, the error is sufficiently small to be inconsequential unless the APSD in nearly monodisperse (GSD ≤1.2), a condition that is unlikely to occur with realistic OIPs. Account may need to be taken of this source of bias only for the most accurate work with abbreviated ACI systems.

  2. An Ordinary Chondrite Impactor Composition for the Bosumtwi Impact Structure, Ghana, West Africa: Discussion of Siderophile Element Contents and Os and Cr Isotope Data

    NASA Technical Reports Server (NTRS)

    Koeberl, Christian; Shukolyukov, Alex; Lugmair, Guenter

    2004-01-01

    Osmium isotope data had shown that Ivory Coast tektites contain an extraterrestrial component, but do not allow distinction between chondritic and iron meteorite contamination. PGE abundances of Ivory Coast tektites and impactites and target rocks from the Bosumtwi crater, the source crater of the Ivory Coast tektites, were all relatively high and did not allow to resolve the presence, or identify the nature, of the meteoritic component. However, Cr isotope analyses of an Ivory Coast tektite yielded a distinct 53Cr excess of 0.30+/-0.06, which indicates that the Bosumtwi impactor was an ordinary chondrite.

  3. An Ordinary Chondrite Impactor Composition for the Bosumtwi Impact Structure, Ghana, West Africa: Discussion of Siderophile Element Contents and Os and Cr Isotope Data

    NASA Technical Reports Server (NTRS)

    Koeberl, Christian; Shukolyukov, Alex; Lugmair, Guenter

    2004-01-01

    Osmium isotope data had shown that Ivory Coast tektites contain an extraterrestrial component, but do not allow distinction between chondritic and iron meteorite contamination. PGE abundances of Ivory Coast tektites and impactites and target rocks from the Bosumtwi crater, the source crater of the Ivory Coast tektites, were all relatively high and did not allow to resolve the presence, or identify the nature, of the meteoritic component. However, Cr isotope analyses of an Ivory Coast tektite yielded a distinct 53Cr excess of 0.30+/-0.06, which indicates that the Bosumtwi impactor was an ordinary chondrite.

  4. [Content analysis of food adverts aimed at children].

    PubMed

    Ponce-Blandón, José Antonio; Pabón-Carrasco, Manuel; Lomas-Campos, María de Las Mercedes

    To determine the contents and persuasive techniques used in processed food adverts aimed at children in Andalusia, comparing them with those aimed at adults. Study based on advert content analysis with two phases: a descriptive design phase and an analytical observational design phase. A sample of adverts from 60hours of broadcasting from the two most watched television channels in Andalusia. A total of 416 food and non-alcoholic beverage adverts were obtained, for 91 different products. Approximately 42.9% (n=39) was aimed at children and 53.8% (n=49) were products classified as "unhealthy". Unhealthy foods were more common in adverts for children (p <0.001). Significant differences were found between the ads aimed at adults and those aimed at children. Emotional and irrational persuasive resources such as fantasy (p <0.001), cartoons (p <0.001) or offering gifts with the purchase of the product (p=0.003) were observed more frequently in adverts for children. Food advertising aimed at children in Andalusia is mainly based on offering products with a low nutritional value and using persuasive resources based on fantasy or gifts. The message is focused on the incentive and not the food. More effective measures than the current self-regulatory systems must be put in place to counter these distorted adverts. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Potential trajectory design for a lunar CubeSat impactor deployed from a HEPO using only a small separation delta-V

    NASA Astrophysics Data System (ADS)

    Song, Young-Joo; Lee, Donghun; Jin, Ho; Kim, Bang-Yeop

    2017-01-01

    Potential impact trajectories for a lunar CubeSat impactor mission are designed and analyzed under the condition that only a small delta-V from the mechanical separation mechanism from the mother-ship is available. The orbit of the mother-ship from which the CubeSat is deployed is assumed to be a Highly Elliptical Polar Orbit (HEPO) around the Moon, and candidate peri- and aposelene altitudes are investigated. The resultant trajectory parameters for the CubeSat impactor are also analyzed. The impact footprint dispersion characteristics are roughly estimated considering the uncertainties that may arise at the moment of CubeSat deployment. As a result, a set of HEPO shapes that can successfully impact the lunar surface using a deployment delta-V of only 2 m/s is discovered. The delta-V required to separate the CubeSat, which is up to tens of m/s, can be greatly reduced depending on the geometry between the Earth and the orientation of the HEPO of the mother-ship at the moment of deployment. The dispersion characteristics of the impact footprint are more sensitive to the uncertainties in the velocity than in the position at the time of separation. From the point of view of the current proposed trajectory design, an uncertainty of less than several tens of cm/s in the velocity should be guaranteed for successful impact within a radius of several tens of kilometers of the target.

  6. Regular and random components in aiming-point trajectory during rifle aiming and shooting.

    PubMed

    Goodman, Simon; Haufler, Amy; Shim, Jae Kun; Hatfieldd, Bradley

    2009-07-01

    The authors examined the kinematic qualities of the aiming trajectory as related to expertise. In all, 2 phases of the trajectory were discriminated. The first phase was regular approximation to the target accompanied by substantial fluctuations obeying the Weber-Fechner law. During the first phase, shooters did not initiate the triggering despite any random closeness of the aiming point (AP) to the target. In the second phase, beginning at 0.6-0.8 s before the trigger pull, shooters applied a different control strategy: They waited until the following random fluctuation brought the AP closer to the target and then initiated triggering. This strategy is tenable when sensitivity of perception is greater than precision of the motor action, and could be considered a case of stochastic resonance. The strategies that novices and experts used distinguished only in the values of parameters. The authors present an analytical model explaining the main properties of shooting.

  7. Regular and Random Components in Aiming-Point Trajectory During Rifle Aiming and Shooting

    PubMed Central

    Goodman, Simon; Haufler, Amy; Shim, Jae Kun; Hatfield, Bradley

    2009-01-01

    The authors examined the kinematic qualities of the aiming trajectory as related to expertise. In all, 2 phases of the trajectory were discriminated. The first phase was regular approximation to the target accompanied by substantial fluctuations obeying the Weber–Fechner law. During the first phase, shooters did not initiate the triggering despite any random closeness of the aiming point (AP) to the target. In the second phase, beginning at 0.6–0.8 s before the trigger pull, shooters applied a different control strategy: They waited until the following random fluctuation brought the AP closer to the target and then initiated triggering. This strategy is tenable when sensitivity of perception is greater than precision of the motor action, and could be considered a case of stochastic resonance. The strategies that novices and experts used distinguished only in the values of parameters. The authors present an analytical model explaining the main properties of shooting. PMID:19508963

  8. AIM-9X Block II Sidewinder (AIM-9X Blk II)

    DTIC Science & Technology

    2013-12-01

    Applicable O&S - Operating and Support Oth - Other PAUC - Program Acquisition Unit Cost PB - President’s Budget PE - Program Element Proc - Procurement...IATO - Interim Authorization to Operate IEA - Information Enterprise Architecture in - Inches IP - Internet Protocol IT - Information Technology ...Block II SAR. RDT&E Appn BA PE Navy 1319 07 0207161N Project Name 0457 Tactical Aim Missile (Shared) Air Force 3600 07 0207161F

  9. Recent Advances in Detection of Ammonia and Nitric Acid on Short Timescales Suitable for Eddy Covariance Flux Measurements

    NASA Astrophysics Data System (ADS)

    Roscioli, Joseph; Herndon, Scott; Zahniser, Mark; Nelson, David; McManus, Barry

    2015-04-01

    Ammonia and nitric acid play important roles in aerosol, cloud, and NOx chemistry. Accurately measuring these species' concentrations on a fast timescale has historically been complicated due to their tendency to slowly and irreversibly interact with instrument surfaces. Here we present recent efforts aimed at mitigating these effects using new inlet technologies. First, an inlet that combines an inertial impactor with a pressure drop across a critical orifice provides particle removal without a traditional filter. This approach is used to reduce instrumental time responses for NH3 and HNO3 to 3-15 seconds. Second, a further reduction in time response is achieved by entraining functionalized perfluoroalkane vapor into the inlet sampling stream. This "active passivation" method is used to achieve time responses of ~0.5 seconds for both NH3 and HNO3, and is found to be applicable to a variety of inlet designs. These technologies enable fast time response sampling suitable for eddy covariance flux measurements.

  10. Characterizing the imaging performance of flash memory masks using AIMS

    NASA Astrophysics Data System (ADS)

    van Setten, Eelco; Wismans, Onno; Grim, Kees; Finders, Jo; Dusa, Mircea; Birkner, Robert; Richter, Rigo; Scherübl, Thomas

    2008-04-01

    Flash memory has become one of the most important segments of the semiconductor industry in recent years. Flash memory is also an important driver of the lithography roadmap, with its dramatic acceleration in dimensional shrink, pushing for ever smaller feature sizes. The introduction of the XT:1700Fi and XT:1900Gi have brought the 45nm node and below within reach for memory makers. At these feature sizes mask topology and the material properties of the film stack on the mask play an important role on imaging performance. Furthermore, the break up of the array pitch regularity in the NAND-type flash memory cell by two thick wordlines and a central space, leads to feature-center placement (overlay) errors, that are inherent to the design. An integral optimization approach is needed to mitigate these effects and to control both the CD and placement errors tightly. In this paper we will present the results of aerial image measurements on mask level of a NAND-Flash Memory Gate layer using AIMS TM 45-193i. Various imaging relevant parameters, such as MEEF, EL, DoF and placement errors are measured for different mask absorber materials for features sizes ranging from 39nm half pitch to 41nm half pitch design rule on wafer level. The AIMS TM measurements are compared to experimental results obtained with a XT:1900Gi hyper-NA immersion system. Mask optimization strategies are sought to increase Depth of Focus and minimize feature-center placement errors.

  11. Strategic Clinical Networks: Alberta's Response to Triple Aim.

    PubMed

    Noseworthy, Tom; Wasylak, Tracy; O'Neill, Blair J

    2016-01-01

    Verma and Bhatia make a compelling case for the Triple Aim to promote health system innovation and sustainability. We concur. Moreover, the authors offer a useful categorization of policies and actions to advance the Triple Aim under the "classic functions" of financing, stewardship and resource generation (Verma and Bhatia 2016). The argument is tendered that provincial governments should embrace the Triple Aim in the absence of federal government leadership, noting that, by international standards, we are at best mediocre and, more realistically, fighting for the bottom in comparative, annual cross-country surveys. Ignoring federal government participation in Medicare and resorting solely to provincial leadership seems to make sense for the purposes of this discourse; but, it makes no sense at all if we are attempting to achieve high performance in Canada's non-system (Canada Health Action: Building on the Legacy 1997; Commission on the Future of Health Care in Canada 2002; Lewis 2015). As for enlisting provincial governments, we heartily agree. A great deal can be accomplished by the Council of the Federation of Canadian Premiers. But, the entire basis for this philosophy and the reference paper itself assumes a top-down approach to policy and practice. That is what we are trying to change in Alberta and we next discuss. Bottom-up clinically led change, driven by measurement and evidence, has to meet with the top-down approach being presented and widely practiced. While true for each category of financing, stewardship and resource generation, in no place is this truer than what is described and included in "health system stewardship." This commentary draws from Verma and Bhatia (2016) and demonstrates how Alberta, through the use of Strategic Clinical Networks (SCNs), is responding to the Triple Aim. We offer three examples of provincially scaled innovations, each representing one or more arms of the Triple Aim.

  12. Evolved mare basalt magmatism, high Mg/Fe feldspathic crust, chondritic impactors, and the petrogenesis of Antarctic lunar breccia meteorites Meteorite Hills 01210 and Pecora Escarpment 02007

    NASA Astrophysics Data System (ADS)

    Day, James M. D.; Floss, Christine; Taylor, Lawrence A.; Anand, Mahesh; Patchen, Allan D.

    2006-12-01

    ferroan anorthosites. A 'chondrule-like' fragment found in PCA 02007 and unlike any previously described lunar material is described and tentatively identified as the remnants of a chondritic lunar impactor. This clast is porphyritic with equant olivines that have forsterite-rich cores (Fo >98), extreme normal zonation to more fayalitic rims (Fo >44), and a mineral assemblage with rare earth element abundances distinct from described lunar material and more similar to chondrules found in ordinary or carbonaceous chondrites. Its discovery and description is significant for understanding the composition of lunar impactors. Previously, the main evidence for chondritic lunar impactors was from chondritic relative abundances and near chondritic ratios of highly siderophile elements in lunar impact melt breccias. However, the presence of this clast, along with two other chondritic clasts from Apollo soils 12037 and 15602, provides clues to the identity of ancient meteorite impactors on the Moon.

  13. Analysis of secondary organic aerosol using a Micro-Orifice Volatilization Impactor (MOVI) coupled to an ion trap mass spectrometer with atmospheric pressure chemical ionization (APCI-IT/MS)

    NASA Astrophysics Data System (ADS)

    Brueggemann, M.; Vogel, A.; Hoffmann, T.

    2012-04-01

    We describe the development and characterization of a Micro-Orifice Volatilization Impactor (MOVI) which is coupled to an ion trap mass spectrometer with atmospheric pressure chemical ionization (APCI-IT/MS), and its application in laboratory and field measurements. The MOVI-APCI-IT/MS allows the quantification of organic acids and other oxidation products of volatile organic compounds (VOCs) in secondary organic aerosols (SOA) on a semi-continuous basis. Furthermore, the vapor pressure and saturation concentration of the particle components can be estimated. The MOVI was first described in 2010 by Yatavelli and Thornton (Yatavelli and Thornton, 2010). It is a single stage, multi-nozzle impactor with 100 nozzles, each having a diameter of 150 μm. At a flow-rate of 10 L·min-1 air is drawn through the MOVI and particles are collected on a deposition plate. The cut-point diameter (d50, diameter of 50% collection efficiency) is at 130 nm. A low pressure-drop of only 5.3% of atmospheric pressure behind the nozzles allows collecting not only low-volatile but even semi-volatile compounds, which are an important part of SOA. After collecting particles hydrocarbon-free synthetic air is led over the collection surface into the APCI-IT/MS and the collection surface is heated up to 120 ° C in less than 200 s, volatilizing the sampled SOA. The vaporized compounds are transferred into the ion source and subsequently analyzed by mass spectrometry. Due to the soft ionization at atmospheric pressure the obtained mass spectra show only low fragmentations and can easily be interpreted. In laboratory experiments the MOVI-APCI-IT/MS was used for the chemical analysis of SOA generated from α-pinene-ozonolysis in a smog chamber. The limit of detection was found at 7.3 ng for pinic acid. The vapor pressure log p0 and the saturation concentration C25* for pinic acid were calculated from the desorption temperature using the method presented by Faulhaber et al. (Faulhaber et al., 2009

  14. Visual regulation of manual aiming: a comparison of methods.

    PubMed

    Elliott, Digby; Hansen, Steve

    2010-11-01

    Visual regulation of upper limb movements occurs throughout the trajectory and is not confined to discrete control in the target area. Early control is based on the dynamic relationship between the limb, the target, and the environment. Despite robust outcome differences between protocols involving visual manipulations, it remains difficult to identify the kinematic events that characterize these differences. In this study, participants performed manual aiming movements with and without vision. We compared several traditional approaches to movement analysis with two new methods of quantifying online limb regulation. As expected, participants undershot the target and their movement endpoints were more variable when vision was not available. Although traditional measures such as reaction time, time after peak velocity, and the presence of discontinuities in acceleration were sensitive to the visual manipulation, measures quantifying the trial-to-trial spatial variability throughout the trajectory were the most effective in isolating the time course of online regulation.

  15. Working memory capacity, controlled attention and aiming performance under pressure.

    PubMed

    Wood, Greg; Vine, Samuel J; Wilson, Mark R

    2016-07-01

    This study explored the possibility that individual differences in working memory capacity (WMC) could predict those individuals who would experience attentional disruptions and performance decrements under pressure. Two WMC groups performed a Stroop handgun task under counterbalanced conditions of threat whilst wearing eye-tracking equipment that measured visual search activity and quiet eye (QE) aiming duration. Performance was measured in terms of shooting accuracy. Low-WMC individuals experienced impaired visual search time to locate the target and reduced QE durations when shooting at incongruent target words. Furthermore, the low-WMC group experienced significant reductions in shooting accuracy when anxious. Conversely, high-WMC individuals experienced no significant differences in attentional control or performance across congruency or threat conditions. Results support the suggestion that WMC is not only a good predictor of an individual's ability to control their attention but can also predict those likely to fail under pressure.

  16. Evidence for a chondritic impactor, evaporation-condensation effects and melting of the Precambrian basement beneath the 'target' Deccan basalts at Lonar crater, India

    NASA Astrophysics Data System (ADS)

    Das Gupta, Rahul; Banerjee, Anupam; Goderis, Steven; Claeys, Philippe; Vanhaecke, Frank; Chakrabarti, Ramananda

    2017-10-01

    The ∼1.88 km diameter Lonar impact crater formed ∼570 ka ago and is an almost circular depression hosted entirely in the Poladpur suite of the ∼65 Ma old basalts of the Deccan Traps. To understand the effects of impact cratering on basaltic targets, commonly found on the surfaces of inner Solar System planetary bodies, major and trace element concentrations as well as Nd and Sr isotopic compositions were determined on a suite of selected samples composed of: basalts, a red bole sample, which is a product of basalt alteration, impact breccia, and impact glasses, either in the form of spherules (<1 mm in diameter) or non-spherical impact glasses (>1 mm and <1 cm). These data include the first highly siderophile element (HSE) concentrations for the Lonar spherules. The chemical index of alteration (CIA) values for the basalts and impact breccia (36.4-42.7) are low while the red bole sample shows a high CIA value (55.6 in the acid-leached sample), consistent with its origin by aqueous alteration of the basalts. The Lonar spherules are classified into two main groups based on their CIA values. Most spherules show low CIA values (Group 1: 34.7-40.5) overlapping with the basalts and impact breccia, while seven spherules show significantly higher CIA values (Group 2: >43.0). The Group 1 spherules are further subdivided into Groups 1a and 1b, with Group 1a spherules showing higher Ni and mostly higher Cr compared to the Group 1b spherules. Iridium and Cr concentrations of the spherules are consistent with the admixture of 1-8 wt% of a chondritic impactor to the basaltic target rocks. The impactor contribution is most prominent in the Group 1a and Group 2 spherules, which show higher Ni/Co, Ni/Cr and Cr/Co ratios compared to the target basalts. In contrast, the Group 1b spherules show major and trace element compositions that overlap with those of the impact breccia and are characterized by high EFTh (Enrichment Factor for Th defined as the Nb-normalized concentration

  17. [Quality documentation with an Anaesthesia Information Management System (AIMS)].

    PubMed

    Junger, A; Benson, M; Quinzio, L; Jost, A; Veit, C; Klöss, T; Hempelmann, G

    1999-08-01

    . In contrast to the hand-written procedure, the AIMS provides recorded data for evaluation and guarantees more detailed and complete quality documentation. In addition, the effort needed for documentation is reduced. Whether these data sets really describe and measure quality or not has to be evaluated. In addition it has to be considered whether different requirements (such as automatic AVB recognition for an AIMS) are advantageous for quality documentation regarding the data raster and the AVB recognition, with respect to different documentation procedures.

  18. Ultimate Educational Aims, Overridingness, and Personal Well-Being

    ERIC Educational Resources Information Center

    Haji, Ishtiyaque; Cuypers, Stefaan E.

    2011-01-01

    Discussion regarding education's aims, especially its ultimate aims, is a key topic in the philosophy of education. These aims or values play a pivotal role in regulating and structuring moral and other types of normative education. We outline two plausible strategies to identify and justify education's ultimate aims. The first associates these…

  19. A proteolytic modification of AIM promotes its renal excretion

    PubMed Central

    Yamazaki, Tomoko; Sugisawa, Ryoichi; Hiramoto, Emiri; Takai, Ryosuke; Matsumoto, Ayaka; Senda, Yoshie; Nakashima, Katsuhiko; Nelson, Peter S.; Lucas, Jared M.; Morgan, Andrew; Li, Zhenghua; Yamamura, Ken-ichi; Arai, Satoko; Miyazaki, Toru

    2016-01-01

    Apoptosis inhibitor of macrophage (AIM, encoded by cd5l) is a multi-functional circulating protein that has a beneficial role in the regulation of a broad range of diseases, some of which are ameliorated by AIM administration in mice. In blood, AIM is stabilized by association with IgM pentamers and maintains its high circulating levels. The mechanism regulating the excessive accumulation of blood AIM remains unknown, although it is important, since a constitutive increase in AIM levels promotes chronic inflammation. Here we found a physiological AIM-cleavage process that induces destabilization of AIM and its excretion in urine. In blood, IgM-free AIM appeared to be cleaved and reduced in size approximately 10 kDa. Cleaved AIM was unable to bind to IgM and was selectively filtered by the glomerulus, thereby excreted in urine. Amino acid substitution at the cleavage site resulted in no renal excretion of AIM. Interestingly, cleaved AIM retained a comparable potency with full-length AIM in facilitating the clearance of dead cell debris in injured kidney, which is a key response in the recovery of acute kidney injury. Identification of AIM-cleavage and resulting functional modification could be the basis for designing safe and efficient AIM therapy for various diseases. PMID:27929116

  20. Stabilization precision control methods of photoelectric aim-stabilized system

    NASA Astrophysics Data System (ADS)

    Song, Xiaoru; Chen, Hua; Xue, Yonggang

    2015-09-01

    To solve the question that photoelectric aim-stabilized system can be controlled with high precision and stability, this paper researches a new photoelectric aim-stabilized control algorithm, analyzes the photoelectric aim-stabilized system architecture, sets up stability control system mathematical model, designs the stability of the photoelectric aim-stabilized LSSVM identification and control system, discusses uncertain factors and calculates the LSSVM parameters by the Chaos theory, gives the predictive controller model by the LSSVM and designs new photoelectric aim-stabilized system. Through the simulation calculation and experimental analysis, new photoelectric aim-stabilized control algorithm was verified; the results show the new photoelectric aim-stabilized control method can meet the demand of high precision control in photoelectric aim-stabilized system.

  1. Prosocial Behavior in Advertising Aimed at Children: A Content Analysis.

    ERIC Educational Resources Information Center

    Stout, Daniel A., Jr.; Mouritsen, Russell H.

    1988-01-01

    Analyzes network, independent, and cable television advertisements aimed at children in terms of their beneficial or "prosocial" examples. Reveals that several commercials aimed at children are rich in examples of sharing, courtesy, and physical affection. (MM)

  2. Laser ablation ICP-MS of size-segregated atmospheric particles collected with a MOUDI cascade impactor: a proof of concept

    NASA Astrophysics Data System (ADS)

    Robinson, Marin S.; Grgić, Irena; Šelih, Vid S.; Šala, Martin; Bitsui, Marsha; van Elteren, Johannes T.

    2017-05-01

    A widely used instrument for collecting size-segregated particles is the micro-orifice uniform deposit impactor (MOUDI). In this work, a 10-stage MOUDI (cut-point diameter of 10 µm to 56 nm) was used to collect samples in Ljubljana, Slovenia, and Martinska, Croatia. Filters, collected with and without rotation, were cut in half and analyzed for nine elements (As, Cu, Fe, Ni, Mn, Pb, Sb, V, Zn) using laser ablation ICP-MS. Elemental image maps (created with ImageJ) were converted to concentrations using NIST SRM 2783. Statistical analysis of the elemental maps indicated that for submicron particles (stages 6-10), ablating 10 % of the filter (0.5 cm2, 20 min ablation time) was sufficient to give values in good agreement (±10 %) to analysis of larger parts of the filter and with good precision (RSE < 1 %). Excellent sensitivity was also observed (e.g., 20 ± 0.2 pg m-3 V). The novel use of LA-ICP-MS, together with image mapping, provided a fast and sensitive method for elemental analysis of size-segregated MOUDI filters, particularly for submicron particles.

  3. The Healthy Communities Study: Its Rationale, Aims, and Approach.

    PubMed

    Arteaga, S Sonia; Loria, Catherine M; Crawford, Patricia B; Fawcett, Stephen B; Fishbein, Howard A; Gregoriou, Maria; John, Lisa V; Kelley, Melinda; Pate, Russell R; Ritchie, Lorrene D; Strauss, Warren J

    2015-10-01

    Communities across the U.S. are implementing programs and policies designed to address the epidemic of childhood obesity. These programs vary widely in their approaches, including the intensity level, duration, funding, target population, and implementation techniques. However, no previous studies have examined these variations and determined how such aspects of community programs and policies are related to childhood obesity outcomes. The Healthy Communities Study is an observational study that is assessing the associations between characteristics of community programs and policies and BMI, nutrition, and physical activity in children. The Healthy Communities Study was funded in 2010, field data collection and medical record abstraction will be completed in 2015, and data cleaning and analyses will be completed by mid-year 2016. One-hundred and thirty communities (defined as a high school catchment area) and approximately 5,000 children in kindergarten through eighth grade and their parents have been recruited from public elementary and middle schools across the country. The study is examining quantitative and qualitative information obtained from community-based initiatives; measures of community characteristics (e.g., school environment); and child and parent measures, including children's physical activity levels and dietary practices and children's and parents' BMI. The Healthy Communities Study employs a complex study design that includes a diverse sample of communities across the country and combines current/cross-sectional and retrospective data (abstracted from children's medical records). This paper describes the rationale for the Healthy Communities Study, the study aims and logic model, and a brief overview of the study design. Published by Elsevier Inc.

  4. Gaussian benchmark for optical communication aiming towards ultimate capacity

    NASA Astrophysics Data System (ADS)

    Lee, Jaehak; Ji, Se-Wan; Park, Jiyong; Nha, Hyunchul

    2016-05-01

    We establish the fundamental limit of communication capacity within Gaussian schemes under phase-insensitive Gaussian channels, which employ multimode Gaussian states for encoding and collective Gaussian operations and measurements for decoding. We prove that this Gaussian capacity is additive, i.e., its upper bound occurs with separable encoding and separable receivers so that a single-mode communication suffices to achieve the largest capacity under Gaussian schemes. This rigorously characterizes the gap between the ultimate Holevo capacity and the capacity within Gaussian communication, showing that Gaussian regime is not sufficient to achieve the Holevo bound particularly in the low-photon regime. Furthermore, the Gaussian benchmark established here can be used to critically assess the performance of non-Gaussian protocols for optical communication. We move on to identify non-Gaussian schemes to beat the Gaussian capacity and show that a non-Gaussian receiver recently implemented by Becerra et al. [F. E. Becerra et al., Nat. Photon. 7, 147 (2013), 10.1038/nphoton.2012.316] can achieve this aim with an appropriately chosen encoding strategy.

  5. Automated Diagnosis Of Faults In Antenna-Aiming Systems

    NASA Technical Reports Server (NTRS)

    Smyth, Patrick J.; Mellstrom, Jeffrey A.

    1993-01-01

    Report discusses research directed toward automated diagnosis of faults in complicated electromechanical and hydraulic systems aiming 70-m and 34-m antennas of Deep Space Network communication system.

  6. Critters: K-6 Life Science Activities. Project AIMS.

    ERIC Educational Resources Information Center

    Allen, Maureen Murphy; And Others

    Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9. Field testing of the curriculum materials produced by AIMS indicates that this integration produces the following beneficial results: (1) mathematics becomes more meaningful, hence more useful; (2) science is…

  7. Student Teachers' Attitude towards Twitter for Educational Aims

    ERIC Educational Resources Information Center

    Marín, Victoria I.; Tur, Gemma

    2014-01-01

    This paper presents an educational experience with 100 student teachers from different courses of the University of the Balearic Islands (Spain) in which Twitter is used for various different activities. The aim of this experiment was to explore student teachers' perceptions in order to value their attitude towards Twitter for educational aims.…

  8. The Aims of Education and the Leap of Freedom

    ERIC Educational Resources Information Center

    Yun, SunInn

    2014-01-01

    This paper considers the place of freedom in discussions of the aims of education. Bearing in mind remarks of R.S. Peters to the affect that the singling out of aims can "fall into the hands of rationalistically minded curriculum planners", it begins by considering the views of Roland Reichenbach regarding Bildung and his account of this…

  9. An Analysis of Aims and the Educational "Event"

    ERIC Educational Resources Information Center

    den Heyer, Kent

    2015-01-01

    In this article, the author explores key distinctions relevant to aims talk in education. He argues that present formulations of aims fail to adequately capture or speak to several overlapping domains involved in schooling: qualification, socialization, and the educational in the form of subjectification (Biesta, 2010). Drawing off Egan and Biesta…

  10. Primarily Plants, A Plant Study for K-3. Project AIMS.

    ERIC Educational Resources Information Center

    Hoover, Evalyn; Mercier, Sheryl

    Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9. Field testing of the curriculum materials produced by AIMS indicates that this interpretation produces the following beneficial results: (1) mathematics becomes more meaningful, hence more useful; (2) science is…

  11. An Analysis of Aims and the Educational "Event"

    ERIC Educational Resources Information Center

    den Heyer, Kent

    2015-01-01

    In this article, the author explores key distinctions relevant to aims talk in education. He argues that present formulations of aims fail to adequately capture or speak to several overlapping domains involved in schooling: qualification, socialization, and the educational in the form of subjectification (Biesta, 2010). Drawing off Egan and Biesta…

  12. The Core of Religious Education: Finnish Student Teachers' Pedagogical Aims

    ERIC Educational Resources Information Center

    Kuusisto, Elina; Tirri, Kirsi

    2014-01-01

    This article investigated the core of religious education (RE) by examining Finnish student teachers' pedagogical aims in the context of Lutheran RE. The data consisted of essays (N=82) analysed in a deductive manner using the main concepts of the didactic triangle together with the aims of the Finnish National Core Curriculum. The student…

  13. Teaching Design Education for Cultural, Pedagogical, and Economic Aims

    ERIC Educational Resources Information Center

    Vande Zande, Robin

    2010-01-01

    The aims of educating for economic, cultural, and pedagogical purposes have existed since the early inception of art education. Looking at how and why these aims evolved in the early era of art and design education has potential for better understanding how and why design should be incorporated into the art education curricula today. This article…

  14. Critters: K-6 Life Science Activities. Project AIMS.

    ERIC Educational Resources Information Center

    Allen, Maureen Murphy; And Others

    Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9. Field testing of the curriculum materials produced by AIMS indicates that this integration produces the following beneficial results: (1) mathematics becomes more meaningful, hence more useful; (2) science is…

  15. Soap Films and Bubbles, Grades 4-9. Project AIMS.

    ERIC Educational Resources Information Center

    Wiebe, Ann

    Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9 on the premise that such integration enriches and makes learning meaningful and holistic. In fact, extensive field testing of the curriculum materials produced by AIMS has confirmed that integration produces the…

  16. Patriotism, History and the Legitimate Aims of American Education

    ERIC Educational Resources Information Center

    Merry, Michael S.

    2009-01-01

    This article argues that while an attachment to one's country is both natural and even partially justifiable, cultivating loyal patriotism in schools is untenable insofar as it conflicts with the legitimate aims of education. These aims include the epistemological competence necessary for ascertaining important truths germane to the various…

  17. Soap Films and Bubbles, Grades 4-9. Project AIMS.

    ERIC Educational Resources Information Center

    Wiebe, Ann

    Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9 on the premise that such integration enriches and makes learning meaningful and holistic. In fact, extensive field testing of the curriculum materials produced by AIMS has confirmed that integration produces the…

  18. The Aims of Education and the Leap of Freedom

    ERIC Educational Resources Information Center

    Yun, SunInn

    2014-01-01

    This paper considers the place of freedom in discussions of the aims of education. Bearing in mind remarks of R.S. Peters to the affect that the singling out of aims can "fall into the hands of rationalistically minded curriculum planners", it begins by considering the views of Roland Reichenbach regarding Bildung and his account of this…

  19. Found in Translation: Interdisciplinary Arts Integration in Project AIM

    ERIC Educational Resources Information Center

    Pruitt, Lara; Ingram, Debra; Weiss, Cynthia

    2014-01-01

    This paper will share the arts-integration methodology used in Project AIM and address the question; "How is translation evident in interdisciplinary arts instruction, and how does it affect students?" Methods: The staff and researchers from Project AIM, (an arts-integration program of the Center for Community Arts Partnerships at…

  20. The Core of Religious Education: Finnish Student Teachers' Pedagogical Aims

    ERIC Educational Resources Information Center

    Kuusisto, Elina; Tirri, Kirsi

    2014-01-01

    This article investigated the core of religious education (RE) by examining Finnish student teachers' pedagogical aims in the context of Lutheran RE. The data consisted of essays (N=82) analysed in a deductive manner using the main concepts of the didactic triangle together with the aims of the Finnish National Core Curriculum. The student…

  1. Teaching Design Education for Cultural, Pedagogical, and Economic Aims

    ERIC Educational Resources Information Center

    Vande Zande, Robin

    2010-01-01

    The aims of educating for economic, cultural, and pedagogical purposes have existed since the early inception of art education. Looking at how and why these aims evolved in the early era of art and design education has potential for better understanding how and why design should be incorporated into the art education curricula today. This article…

  2. Primarily Plants, A Plant Study for K-3. Project AIMS.

    ERIC Educational Resources Information Center

    Hoover, Evalyn; Mercier, Sheryl

    Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9. Field testing of the curriculum materials produced by AIMS indicates that this interpretation produces the following beneficial results: (1) mathematics becomes more meaningful, hence more useful; (2) science is…

  3. Airborne Atmospheric Aerosol Measurement System

    NASA Astrophysics Data System (ADS)

    Ahn, K.; Park, Y.; Eun, H.; Lee, H.

    2015-12-01

    It is important to understand the atmospheric aerosols compositions and size distributions since they greatly affect the environment and human health. Particles in the convection layer have been a great concern in global climate changes. To understand these characteristics satellite, aircraft, and radio sonde measurement methods have usually been used. An aircraft aerosol sampling using a filter and/or impactor was the method commonly used (Jay, 2003). However, the flight speed particle sampling had some technical limitations (Hermann, 2001). Moreover, the flight legal limit, altitude, prohibited airspace, flight time, and cost was another demerit. To overcome some of these restrictions, Tethered Balloon Package System (T.B.P.S.) and Recoverable Sonde System(R.S.S.) were developed with a very light optical particle counter (OPC), impactor, and condensation particle counter (CPC). Not only does it collect and measure atmospheric aerosols depending on altitudes, but it also monitors the atmospheric conditions, temperature, humidity, wind velocity, pressure, GPS data, during the measurement (Eun, 2013). In this research, atmospheric aerosol measurement using T.B.P.S. in Ansan area is performed and the measurement results will be presented. The system can also be mounted to an unmanned aerial vehicle (UAV) and create an aerial particle concentration map. Finally, we will present measurement data using Tethered Balloon Package System (T.B.P.S.) and R.S.S (Recoverable Sonde System).

  4. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians maneuver the spacecraft handling fixture toward the AIM spacecraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  5. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    At North Vandenberg Air Force Base in California, the AIM spacecraft is moved into a clean room for testing. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  6. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians lower the spacecraft handling fixture around the AIM spacecraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  7. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians roll the AIM spacecraft back under the protective clean tent. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  8. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians lower the AIM spacecraft onto a moveable stand. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  9. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    At North Vandenberg Air Force Base in California, the AIM spacecraft is prepared for its move to the clean room for testing. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  10. Implementation of an Anesthesia Information Management System (AIMS)

    PubMed Central

    Douglas, James R.; Ritter, Melody J.

    2011-01-01

    During the administration of anesthesia, the anesthesia provider has historically created a paper record, charted manually, that included extensive patient care–related data (vital signs, other parameters, etc) and commentaries. DocuSys, a proprietary anesthesia information management system (AIMS), creates an electronic version of the anesthesia record and provides additional information. It electronically captures data from clinical monitors and other sources, including scheduling applications and laboratory computers. The AIMS facilitates chart entries such as drug doses and case narratives. Benefits of an AIMS include improved legibility of the anesthesia record and greater efficiency in documentation efforts. Use of the AIMS assists the practitioner with decision support logic, such as the timing of antibiotic administration and the inclusion of legally required documentation. Upon case completion, the AIMS data are immediately available to other information systems, such as billing and medical records. Data can be made available from a single case or, more important, from thousands of cases to analyze variables such as efficiency of services, adherence to best practices, patient outcomes, and clinical research. The AIMS was deployed at the main campus of the Ochsner Health System on March 26, 2009. In this article, we discuss the issues involved in the AIMS implementation process: the successes, surprises, and continued challenges. PMID:21734847

  11. Implementation of an Anesthesia Information Management System (AIMS).

    PubMed

    Douglas, James R; Ritter, Melody J

    2011-01-01

    During the administration of anesthesia, the anesthesia provider has historically created a paper record, charted manually, that included extensive patient care-related data (vital signs, other parameters, etc) and commentaries. DocuSys, a proprietary anesthesia information management system (AIMS), creates an electronic version of the anesthesia record and provides additional information. It electronically captures data from clinical monitors and other sources, including scheduling applications and laboratory computers. The AIMS facilitates chart entries such as drug doses and case narratives. Benefits of an AIMS include improved legibility of the anesthesia record and greater efficiency in documentation efforts. Use of the AIMS assists the practitioner with decision support logic, such as the timing of antibiotic administration and the inclusion of legally required documentation. Upon case completion, the AIMS data are immediately available to other information systems, such as billing and medical records. Data can be made available from a single case or, more important, from thousands of cases to analyze variables such as efficiency of services, adherence to best practices, patient outcomes, and clinical research. The AIMS was deployed at the main campus of the Ochsner Health System on March 26, 2009. In this article, we discuss the issues involved in the AIMS implementation process: the successes, surprises, and continued challenges.

  12. IR modules and long-life Stirling cryocoolers at AIM

    NASA Astrophysics Data System (ADS)

    Korf, Herbert; Cabanski, Wolfgang A.; Wendler, C. J.; Wild, U.; Ziegler, Johann

    1998-10-01

    The last 10 years of engineering and production at AEG INFRAROT-MODULE GmbH (AIM) resulted in continued improvements in performance, yield and reliability of IR modules and cryocoolers. For the optimizing of engineering, production and testing over the complete scope, from semiconductor material growth, FPA fabrication, cryo packaging data processing and software, cooling, etc. up to the camera level, AIM has all critical technologies under one roof. This paper demonstrates how such results were achieved, which criteria are to be met for performance, yield and cost improvements and how contemporary IR modules from AIM reflect these achievements.

  13. Evaluation of the Community Multiscale Air Quality (CMAQ) modeling system against size-resolved measurements of inorganic particle composition across sites in North America

    EPA Science Inventory

    This work evaluates particle size-composition distributions simulated by the Community Multiscale Air Quality (CMAQ) model using Micro-Orifice Uniform Deposit Impactor (MOUDI) measurements at 18 sites across North America. Size-resolved measurements of particulate SO4<...

  14. Evaluation of the Community Multiscale Air Quality (CMAQ) modeling system against size-resolved measurements of inorganic particle composition across sites in North America

    EPA Science Inventory

    This work evaluates particle size-composition distributions simulated by the Community Multiscale Air Quality (CMAQ) model using Micro-Orifice Uniform Deposit Impactor (MOUDI) measurements at 18 sites across North America. Size-resolved measurements of particulate SO4<...

  15. Researchers Take Aim At Insecticide-Resistant Bedbugs

    MedlinePlus

    ... Aim at Insecticide-Resistant Bedbugs New fungal-based pesticide might knock out insects that survive current chemicals ... use in bedbug management," Jenkins said. The new pesticide worked on all four strains of bedbugs, the ...

  16. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians prepare the AIM spacecraft for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  17. The mated Pegasus XL rocket - AIM spacecraft leaves Building 165

    NASA Image and Video Library

    2007-04-16

    The mated Pegasus XL rocket - AIM spacecraft leaves Building 1655 at Vandenberg Air Force Base in California. The rocket will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  18. The mated Pegasus XL rocket - AIM spacecraft leaves Building 165

    NASA Image and Video Library

    2007-04-16

    The mated Pegasus XL rocket - AIM spacecraft is secured onto a transporter at Vandenberg Air Force Base in California. The rocket will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  19. The mated Pegasus XL rocket - AIM spacecraft leaves Building 165

    NASA Image and Video Library

    2007-04-16

    The mated Pegasus XL rocket - AIM spacecraft is moved onto a transporter in Building 1655 at Vandenberg Air Force Base in California. The launch vehicle will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  20. Real-Time Estimation Of Aiming Error Of Spinning Antenna

    NASA Technical Reports Server (NTRS)

    Dolinsky, Shlomo

    1992-01-01

    Spinning-spacecraft dynamics and amplitude variations in communications links studied from received-signal fluctuations. Mathematical model and associated analysis procedure provide real-time estimates of aiming error of remote rotating transmitting antenna radiating constant power in narrow, pencillike beam from spinning platform, and current amplitude of received signal. Estimates useful in analyzing and enhancing calibration of communication system, and in analyzing complicated dynamic effects in spinning platform and antenna-aiming mechanism.

  1. Ethics and aims in psychotherapy: a contribution from Kant.

    PubMed Central

    Callender, J S

    1998-01-01

    Psychotherapy is an activity which takes many forms and which has many aims. The present paper argues that it can be viewed as a form of moral suasion. Kant's concepts of free will and ethics are described and these are then applied to the processes and outcome of psychotherapy. It is argued that his ideas, by linking rationality, free will and ethics into a single philosophical system, offer a valuable theoretical framework for thinking about aims and ethical issues in psychotherapy. PMID:9752632

  2. Ethics and aims in psychotherapy: a contribution from Kant.

    PubMed

    Callender, J S

    1998-08-01

    Psychotherapy is an activity which takes many forms and which has many aims. The present paper argues that it can be viewed as a form of moral suasion. Kant's concepts of free will and ethics are described and these are then applied to the processes and outcome of psychotherapy. It is argued that his ideas, by linking rationality, free will and ethics into a single philosophical system, offer a valuable theoretical framework for thinking about aims and ethical issues in psychotherapy.

  3. Automated Iodine Monitoring System Development (AIMS). [shuttle prototype

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The operating principle of the automated iodine monitoring/controller system (AIMS) is described along with several design modifications. The iodine addition system is also discussed along with test setups and calibration; a facsimile of the optical/mechanical portion of the iodine monitor was fabricated and tested. The appendices include information on shuttle prototype AIMS, preliminary prime item development specifications, preliminary failure modes and effects analysis, and preliminary operating and maintenance instructions.

  4. Pursuing the Triple Aim: The First 7 Years

    PubMed Central

    Whittington, John W; Nolan, Kevin; Lewis, Ninon; Torres, Trissa

    2015-01-01

    Context In 2008, researchers at the Institute for Healthcare Improvement (IHI) described the Triple Aim as simultaneously “improving the individual experience of care; improving the health of populations; and reducing the per capita costs of care for populations.” IHI and its close colleagues had determined that both individual and societal changes were needed. Methods In 2007, IHI began recruiting organizations from around the world to participate in a collaborative to implement what became known as the Triple Aim. The 141 participating organizations included health care systems, hospitals, health care insurance companies, and others closely tied to health care. In addition, key groups outside the health care system were represented, such as public health agencies, social services groups, and community coalitions. This collaborative provided a structure for observational research. By noting the contrasts between the contexts and structures of those sites in the collaborative that progressed and those that did not, we were able to develop an ex post theory of what is needed for an organization or community to successfully pursue the Triple Aim. Findings Drawing on our 7 years of experience, we describe the 3 major principles that guided the organizations and communities working on the Triple Aim: creating the right foundation for population management, managing services at scale for the population, and establishing a learning system to drive and sustain the work over time. Conclusions The concept of the Triple Aim is now widely used, because of IHI's work with many organizations and also because of the adoption of the Triple Aim as part of the national strategy for US health care, developed during the implementation of the Patient Protection and Affordable Care Act of 2010. Even those organizations working on the Triple Aim before IHI coined the term found our concept to be useful because it helped them think about all 3 dimensions at once and organize their

  5. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians look over the spacecraft handling fixture that will be used to lift the AIM spacecraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  6. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians work on the separation system to be mated to the AIM spacecraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  7. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians work on the separation system to be mated to the AIM spacecraft, hovering above it. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  8. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians carry the separation system, at left, toward the AIM spacecraft hovering above the stand at right. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  9. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians move a mobile stand toward the AIM spacecraft suspended via a crane at left. . AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  10. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    At North Vandenberg Air Force Base in California, the AIM spacecraft has been rotated to horizontal prior to its move to the clean room for testing. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  11. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    In Building 1555 on North Vandenberg Air Force Base in California, technicians lift the AIM spacecraft via the spacecraft handling fixture attached to it. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  12. Extended run distance measurements of shock initiation in PBX 9502

    SciTech Connect

    Gustavsen, R. L.; Sheffield, S. A.; Alcon, R. R.

    2007-12-12

    We have completed a series of shock initiation experiments on two lots of PBX 9502 (95 weight % TATB, 5 weight % Kel-F 800 binder). One PBX 9502 lot contained few fine particles (10 weight % <20 microns) while the second lot contained many fines (38 weight % <20 microns). Large, 71 mm diameter PBX 9502 samples were used and input pressures were 7.5-8.5 GPa, resulting in run distances of 25-35 mm. Buildup to detonation was measured using embedded magnetic particle velocity gauges. An unusual feature of the work was the use of metallic impactors (316 stainless steel) in combination with magnetic gauges. It has previously been assumed that conducting impactors would badly perturb the magnetic gauge measurements. However, we observed only a baseline voltage shift of {approx_equal}10% which increased linearly with time. Results include detonation coordinates (x*, t*) vs. initial shock pressure. No lot to lot differences in initiation behavior were observed.

  13. Integration of alternating monocular samples during goal-directed aiming.

    PubMed

    Hansen, Steve; Hayes, Spencer J; Bennett, Simon J

    2013-01-01

    The current study examined the effect of interocular delay in a manual aiming task that required accurate end-point placement, but not precise control of a grip aperture. Participants aimed in binocular, monocular, or alternating monocular vision conditions. For the latter, 25ms monocular samples were provided to alternate eyes without delay (0ms), or a delay of 25 or 50ms. The interocular delay resulted in a longer movement time, caused by a longer time-to-peak and time-after-peak velocity, and a reduction in peak velocity. We suggest that the change in kinematics reflect a strategic response to preserve terminal aiming accuracy and variability when faced with an informational perturbation. These findings indicate that the response to the interocular delay between alternating monocular samples depends on the task-specific information used to control that behavior.

  14. The International Particle Physics Outreach Group (ippog):. Aims and Activities

    NASA Astrophysics Data System (ADS)

    Barney, David

    2012-08-01

    The International Particle Physics Outreach Group, IPPOG, is a network of particle physics communication and education experts. IPPOG's principle aim is to maximize the impact of education and outreach efforts related to particle physics through information exchange and the sharing of expertise. IPPOG has initiated several major European and Worldwide activities, such as the "International Particle Physics Masterclasses" where each year thousands of high school students in more than 20 countries come to one of about 120 nearby universities or research centres for a day in order to unravel the mysteries of particle physics. IPPOG has also initiated a global database of education and outreach materials, aimed at supporting other particle physicists and education professionals. The aims and activities of IPPOG will be described, as well as plans to include more countries & laboratories in the network.

  15. Geochemistry of impact glasses and target rocks from the Zhamanshin impact structure, Kazakhstan: Implications for mixing of target and impactor matter

    NASA Astrophysics Data System (ADS)

    Jonášová, Šárka; Ackerman, Lukáš; Žák, Karel; Skála, Roman; Ďurišová, Jana; Deutsch, Alexander; Magna, Tomáš

    2016-10-01

    Internal structure and element chemistry including contents of highly siderophile elements (HSE) and Os isotope ratios have been studied in target rocks and several groups of impact glasses of the Zhamanshin impact structure, Kazakhstan. These include larger irregularly-shaped fragments and blocks of impact glass (zhamanshinites), and three types of tektite-like splash-form glasses, part of fallback ejecta. These glassy objects typically are up to 30 mm large and are shaped as teardrops, irregularly bent and curved glass rods and fibers. They can be subdivided into acidic types (irghizites; typically 69-76 wt.% SiO2), basic splash-forms (typically 53-56 wt.% SiO2), and rarely occurring highly inhomogeneous composites with abundant mineral inclusions. A comparison with the target rocks shows that zhamanshinites and basic splash-forms usually have no detectable admixture of the projectile matter, indicated by major and trace elements as well as highly siderophile element contents, with the exception of one sample containing Fe-, Cr-, Ni- and Ti-enriched particles and elevated HSE contents. In contrast, irghizites exhibit clear admixture of the projectile matter, which was incorporated by complex processes accompanied by strong element fractionations. Microscopic investigations confirm that irghizites were formed mainly by coalescence of smaller molten glass droplets sized typically below 1 mm. Irghizites exhibit significant enrichments in Ni, Co and Cr, whose concentrations are locally elevated in the rims of the original small droplets. A portion of these elements and also part of Fe and Mn and other elements were derived from the impactor, most likely a Ni-rich carbonaceous chondrite. The contents of HSE are low and strongly fractionated, with moderate depletions of Pt and Pd and strong depletions of other HSE with respect to chondritic element ratios. Osmium shows the strongest depletion, likely related to the presence of oxygen in the post-impact atmosphere

  16. Advanced Industrial Materials (AIM) Program annual progress report, FY 1997

    SciTech Connect

    1998-05-01

    The Advanced Industrial Materials (AIM) Program is a part of the Office of Industrial Technologies (OIT), Energy Efficiency and Renewable Energy, US Department of Energy (DOE). The mission of AIM is to support development and commercialization of new or improved materials to improve energy efficiency, productivity, product quality, and reduced waste in the major process industries. OIT has embarked on a fundamentally new way of working with industries--the Industries of the Future (IOF) strategy--concentrating on the major process industries that consume about 90% of the energy and generate about 90% of the waste in the industrial sector. These are the aluminum, chemical, forest products, glass, metalcasting, and steel industries. OIT has encouraged and assisted these industries in developing visions of what they will be like 20 or 30 years into the future, defining the drivers, technology needs, and barriers to realization of their visions. These visions provide a framework for development of technology roadmaps and implementation plans, some of which have been completed. The AIM Program supports IOF by conducting research and development on materials to solve problems identified in the roadmaps. This is done by National Laboratory/industry/university teams with the facilities and expertise needed to develop new and improved materials. Each project in the AIM Program has active industrial participation and support.

  17. Rockwell AIM 65 Interfacing: Physics Lab Applications, Air Track Kinematics.

    ERIC Educational Resources Information Center

    Vacha, T. H.

    The Rockwell AIM 65 is recommended for use in physics laboratories. Among advantages cited are that the basic board can be purchased customized; for example, it can be purchased with or without a printer, power supply, extra memory, and other items. In addition, the computer is basically designed to control equipment and take data from peripheral…

  18. R. S. Peters' Normative Conception of Education and Educational Aims

    ERIC Educational Resources Information Center

    Katz, Michael S.

    2009-01-01

    This article aims to highlight why R. S. Peters' conceptual analysis of "education" was such an important contribution to the normative field of philosophy of education. In the article, I do the following: 1) explicate Peters' conception of philosophy of education as a field of philosophy and explain his approach to the philosophical analysis of…

  19. Goal-directed aiming: two components but multiple processes.

    PubMed

    Elliott, Digby; Hansen, Steve; Grierson, Lawrence E M; Lyons, James; Bennett, Simon J; Hayes, Spencer J

    2010-11-01

    This article reviews the behavioral literature on the control of goal-directed aiming and presents a multiple-process model of limb control. The model builds on recent variants of Woodworth's (1899) two-component model of speed-accuracy relations in voluntary movement and incorporates ideas about dynamic online limb control based on prior expectations about the efferent and afferent consequences of a planned movement. The model considers the relationship between movement speed and accuracy, and how performers adjust their trial-to-trial aiming behavior to find a safe, but fast, zone for movement execution. The model also outlines how the energy and safety costs associated with different movement outcomes contribute to movement planning processes and the control of aiming trajectories. Our theoretical position highlights the importance of advance knowledge about the sensory information that will be available for online control and the need to develop a robust internal representation of expected sensory consequences. We outline how early practice contributes to optimizing strategic planning to avoid worst-case outcomes associated with inherent neural-motor variability. Our model considers the role of both motor development and motor learning in refining feed-forward and online control. The model reconciles procedural and representational accounts of the specificity-of-learning phenomenon. Finally, we examine the breakdown of perceptual-motor precision in several special populations (i.e., Down syndrome, Williams syndrome, autism spectrum disorder, normal aging) within the framework of a multiple-process approach to goal-directed aiming.

  20. The Aims of Sex Education: Demoting Autonomy and Promoting Mutuality

    ERIC Educational Resources Information Center

    McAvoy, Paula

    2013-01-01

    In this essay, Paula McAvoy critiques a commonly held view that teaching young people to be good choice makers should be a central aim of sex education. Specifically, she argues against David Archard's recommendation that sex educators ought to focus on the development of autonomy and teaching young people that "choice should be accorded…

  1. The Aims of Sex Education: Demoting Autonomy and Promoting Mutuality

    ERIC Educational Resources Information Center

    McAvoy, Paula

    2013-01-01

    In this essay, Paula McAvoy critiques a commonly held view that teaching young people to be good choice makers should be a central aim of sex education. Specifically, she argues against David Archard's recommendation that sex educators ought to focus on the development of autonomy and teaching young people that "choice should be accorded…

  2. Why the Aims of Education Cannot Be Settled

    ERIC Educational Resources Information Center

    Hardarson, Atli

    2012-01-01

    The dominant model of curriculum design in the last century assumed that school education could be organized around aims, defined primarily in terms of students' behaviour. The credentials of this model were questioned by, among others, Lawrence Stenhouse, who pointed out that education serves purposes that cannot be stated in terms of behavioural…

  3. An Examination of OMB Forms Clearance Aims, Policies and Procedures.

    ERIC Educational Resources Information Center

    Coan, Donald L.; Bertram, Charles L.

    The purposes of this paper are four-fold: (1) to delineate the principal aims and policy objectives of Office of Management and Budget Forms Clearance (OMB FC), as embodied in Federal legislation and executive directives since 1942; (2) to identify the major current thrusts of OMB FC; (3) to suggest possible future policy directions of OMB FC,…

  4. MayDay Colloquium 24: The Aims of Music Education

    ERIC Educational Resources Information Center

    Elliott, David J.

    2013-01-01

    On June 20, 2012, Professor John Kratus welcomed the MayDay Group to Michigan State University for "Colloquium 24: The Aims of Music Education". On behalf of all members of the Mayday Group, the author wishes to extend his deepest gratitude to Professor Kratus and his colleagues at Michigan State for their extremely gracious and…

  5. Why the Aims of Education Cannot Be Settled

    ERIC Educational Resources Information Center

    Hardarson, Atli

    2012-01-01

    The dominant model of curriculum design in the last century assumed that school education could be organized around aims, defined primarily in terms of students' behaviour. The credentials of this model were questioned by, among others, Lawrence Stenhouse, who pointed out that education serves purposes that cannot be stated in terms of behavioural…

  6. Aiming for a College Education: A Strategy for Scotland.

    ERIC Educational Resources Information Center

    McPherson, Andrew; And Others

    The report reviews British Petroleum's "Aiming for College Education" program in Scotland, a 5-year program to raise the aspirations of young people for post-compulsory education and for higher education in particular. The program invites local higher education institutions to consider initiatives in four areas (promotion and marketing,…

  7. Technicians prepare the AIM spacecraft for fairing installation

    NASA Image and Video Library

    2007-04-12

    At Vandenberg Air Force Base in California, technicians prepare the AIM spacecraft for fairing installation. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  8. AIM being prepared for integrated testing and flight simulation

    NASA Image and Video Library

    2007-03-24

    Flight simulation No. 3 is on the schedule for the Pegasus XL launch vehicle, seen here in Building 1555 on North Vandenberg Air Force Base in California. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. AIM is scheduled to be mated to its launch vehicle, Orbital Sciences' Pegasus XL, during the second week of April, after which final inspections will be conducted. Launch is scheduled for April 25.

  9. Autonomy as the Guiding Aim of Entrepreneurship Education

    ERIC Educational Resources Information Center

    van Gelderen, Marco

    2010-01-01

    Purpose: This paper has three purposes: first, to present a vision of entrepreneurship education that has the student's capacity for autonomous action as its ultimate aim; second, to convince the reader of the timeliness and relevance of such an approach; third, to outline how this can be implemented. Design/methodology/approach: The paper…

  10. Advanced Industrial Materials (AIM) Program: Annual progress report FY 1995

    SciTech Connect

    1996-04-01

    In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This Annual Report for FY 1995 contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Areas covered here are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes.

  11. Philosophical Analysis, Research on Teaching, and Aim-Oriented Empiricism.

    ERIC Educational Resources Information Center

    Popp, Jerome A.

    1980-01-01

    An attempt is made at providing cohesion and structure for a range of disparate activities and examining their interrelationships. Among concepts considered are: (1) the relationship of philosophic analysis in education; (2) the nature of pedagogical research; (3) the process-product paradigm; (4) aim-oriented empiricism; (5) the reduction thesis;…

  12. Autonomy as the Guiding Aim of Entrepreneurship Education

    ERIC Educational Resources Information Center

    van Gelderen, Marco

    2010-01-01

    Purpose: This paper has three purposes: first, to present a vision of entrepreneurship education that has the student's capacity for autonomous action as its ultimate aim; second, to convince the reader of the timeliness and relevance of such an approach; third, to outline how this can be implemented. Design/methodology/approach: The paper…

  13. MayDay Colloquium 24: The Aims of Music Education

    ERIC Educational Resources Information Center

    Elliott, David J.

    2013-01-01

    On June 20, 2012, Professor John Kratus welcomed the MayDay Group to Michigan State University for "Colloquium 24: The Aims of Music Education". On behalf of all members of the Mayday Group, the author wishes to extend his deepest gratitude to Professor Kratus and his colleagues at Michigan State for their extremely gracious and…

  14. Technicians prepare the AIM spacecraft for fairing installation

    NASA Image and Video Library

    2007-04-12

    At Vandenberg Air Force Base in California, under the protective clean tent, technicians work on the second half of the fairing to be installed around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  15. Technicians prepare the AIM spacecraft for fairing installation

    NASA Image and Video Library

    2007-04-12

    At Vandenberg Air Force Base in California, under the protective clean tent, technicians begin installing the fairing around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  16. Technicians prepare the AIM spacecraft for fairing installation

    NASA Image and Video Library

    2007-04-12

    At Vandenberg Air Force Base in California, under the protective clean tent, technicians maneuver the second half of the fairing into place around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  17. Technicians prepare the AIM spacecraft for fairing installation

    NASA Image and Video Library

    2007-04-12

    At Vandenberg Air Force Base in California, under the protective clean tent, technicians examine the installation of the fairing around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  18. Technicians prepare the AIM spacecraft for fairing installation

    NASA Image and Video Library

    2007-04-12

    At Vandenberg Air Force Base in California, under the protective clean tent, technicians move the second half of the fairing into place around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

  19. [Patient's aggression aimed at physicians. Legal interpretation of defense possibilities].

    PubMed

    Patryn, Rafał

    2013-01-01

    The aim of the following study is to acquaint medical practitioners with legal possibilities of defense against patients'aggression. The occurrence of the described and discussed issue, namely the appearance of different forms of aggression aimed at physicians and other medical staff is a more and more frequently appearing phenomenon, which is very problematic, and difficult to interpret. The scope of the analysis has been limited to aggression of patients towards physicians only, as they are most often the aim of this aggression, and what should be emphasized, they lack practical and universal solutions and frequently also necessary knowledge to protect themselves against it. The idea behind this study is to present a rational solution to the afore mentioned situation, within legal limits. First, an outline of a conflict situation with a short specification of sources of aggression will be presented, than an appropriate legal taxonomy (including civil and criminal law) allowing for aid in such a situation will be offered and discussed.The authors will also present practical and legally permissible solutions aiming at defense, abandonment, and not allowing for the appearance of this reprehensible phenomenon.

  20. The General Aims of Educational Development -- A Comparative Prospect.

    ERIC Educational Resources Information Center

    Dahawy, Bayoumi Mohamed

    The inconsistency between norms prescribed by international agencies and the educational strategies suggested to put these norms into practice has created problems as is evident in the case studies of India and Egypt and the general aims of educational development in these two countries. In Egypt a policy of basic education had the support of…

  1. Goal-Directed Aiming: Two Components but Multiple Processes

    ERIC Educational Resources Information Center

    Elliott, Digby; Hansen, Steve; Grierson, Lawrence E. M.; Lyons, James; Bennett, Simon J.; Hayes, Spencer J.

    2010-01-01

    This article reviews the behavioral literature on the control of goal-directed aiming and presents a multiple-process model of limb control. The model builds on recent variants of Woodworth's (1899) two-component model of speed-accuracy relations in voluntary movement and incorporates ideas about dynamic online limb control based on prior…

  2. Research Project on Educational Aims. Research Bulletin 60.

    ERIC Educational Resources Information Center

    Niskanen, Erkki A.; And Others

    Summaries of classroom research studies conducted in Finland on the development of educational aims are presented. Papers in this document deal with: (1) an overview of the purposes of the research project; (2) cognitive processes in classroom verbal interaction; (3) taxonomy of physical education; (4) objectives of religious education; (5)…

  3. Goal-Directed Aiming: Two Components but Multiple Processes

    ERIC Educational Resources Information Center

    Elliott, Digby; Hansen, Steve; Grierson, Lawrence E. M.; Lyons, James; Bennett, Simon J.; Hayes, Spencer J.

    2010-01-01

    This article reviews the behavioral literature on the control of goal-directed aiming and presents a multiple-process model of limb control. The model builds on recent variants of Woodworth's (1899) two-component model of speed-accuracy relations in voluntary movement and incorporates ideas about dynamic online limb control based on prior…

  4. Pursuing the Triple Aim: The First 7 Years.

    PubMed

    Whittington, John W; Nolan, Kevin; Lewis, Ninon; Torres, Trissa

    2015-06-01

    POLICY POINTS: In 2008, researchers at the Institute for Healthcare Improvement (IHI) proposed the Triple Aim, strategic organizing principles for health care organizations and geographic communities that seek, simultaneously, to improve the individual experience of care and the health of populations and to reduce the per capita costs of care for populations. In 2010, the Triple Aim became part of the US national strategy for tackling health care issues, especially in the implementation of the Patient Protection and Affordable Care Act (ACA) of 2010. Since that time, IHI and others have worked together to determine how the implementation of the Triple Aim has progressed. Drawing on our 7 years of experience, we describe 3 major principles that guided the organizations and communities working on this endeavor: creating the right foundation for population management, managing services at scale for the population, and establishing a learning system to drive and sustain the work over time. In 2008, researchers at the Institute for Healthcare Improvement (IHI) described the Triple Aim as simultaneously "improving the individual experience of care; improving the health of populations; and reducing the per capita costs of care for populations." IHI and its close colleagues had determined that both individual and societal changes were needed. In 2007, IHI began recruiting organizations from around the world to participate in a collaborative to implement what became known as the Triple Aim. The 141 participating organizations included health care systems, hospitals, health care insurance companies, and others closely tied to health care. In addition, key groups outside the health care system were represented, such as public health agencies, social services groups, and community coalitions. This collaborative provided a structure for observational research. By noting the contrasts between the contexts and structures of those sites in the collaborative that progressed and

  5. SAGE II aerosol data validation based on retrieved aerosol model size distribution from SAGE II aerosol measurements

    NASA Technical Reports Server (NTRS)

    Wang, Pi-Huan; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.; Swissler, T. J.; Osborn, M. T.; Russell, P. B.; Oberbeck, V. R.; Livingston, J.; Rosen, J. M.

    1989-01-01

    Consideration is given to aerosol correlative measurements experiments for the Stratospheric Aerosol and Gas Experiment (SAGE) II, conducted between November 1984 and July 1986. The correlative measurements were taken with an impactor/laser probe, a dustsonde, and an airborne 36-cm lidar system. The primary aerosol quantities measured by the ground-based instruments are compared with those calculated from the aerosol size distributions from SAGE II aerosol extinction measurements. Good agreement is found between the two sets of measurements.

  6. Automated Instrumentation, Monitoring and Visualization of PVM Programs Using AIMS

    NASA Technical Reports Server (NTRS)

    Mehra, Pankaj; VanVoorst, Brian; Yan, Jerry; Tucker, Deanne (Technical Monitor)

    1994-01-01

    We present views and analysis of the execution of several PVM codes for Computational Fluid Dynamics on a network of Sparcstations, including (a) NAS Parallel benchmarks CG and MG (White, Alund and Sunderam 1993); (b) a multi-partitioning algorithm for NAS Parallel Benchmark SP (Wijngaart 1993); and (c) an overset grid flowsolver (Smith 1993). These views and analysis were obtained using our Automated Instrumentation and Monitoring System (AIMS) version 3.0, a toolkit for debugging the performance of PVM programs. We will describe the architecture, operation and application of AIMS. The AIMS toolkit contains (a) Xinstrument, which can automatically instrument various computational and communication constructs in message-passing parallel programs; (b) Monitor, a library of run-time trace-collection routines; (c) VK (Visual Kernel), an execution-animation tool with source-code clickback; and (d) Tally, a tool for statistical analysis of execution profiles. Currently, Xinstrument can handle C and Fortran77 programs using PVM 3.2.x; Monitor has been implemented and tested on Sun 4 systems running SunOS 4.1.2; and VK uses X11R5 and Motif 1.2. Data and views obtained using AIMS clearly illustrate several characteristic features of executing parallel programs on networked workstations: (a) the impact of long message latencies; (b) the impact of multiprogramming overheads and associated load imbalance; (c) cache and virtual-memory effects; and (4significant skews between workstation clocks. Interestingly, AIMS can compensate for constant skew (zero drift) by calibrating the skew between a parent and its spawned children. In addition, AIMS' skew-compensation algorithm can adjust timestamps in a way that eliminates physically impossible communications (e.g., messages going backwards in time). Our current efforts are directed toward creating new views to explain the observed performance of PVM programs. Some of the features planned for the near future include: (a) Config

  7. Automated Instrumentation, Monitoring and Visualization of PVM Programs Using AIMS

    NASA Technical Reports Server (NTRS)

    Mehra, Pankaj; VanVoorst, Brian; Yan, Jerry; Lum, Henry, Jr. (Technical Monitor)

    1994-01-01

    We present views and analysis of the execution of several PVM (Parallel Virtual Machine) codes for Computational Fluid Dynamics on a networks of Sparcstations, including: (1) NAS Parallel Benchmarks CG and MG; (2) a multi-partitioning algorithm for NAS Parallel Benchmark SP; and (3) an overset grid flowsolver. These views and analysis were obtained using our Automated Instrumentation and Monitoring System (AIMS) version 3.0, a toolkit for debugging the performance of PVM programs. We will describe the architecture, operation and application of AIMS. The AIMS toolkit contains: (1) Xinstrument, which can automatically instrument various computational and communication constructs in message-passing parallel programs; (2) Monitor, a library of runtime trace-collection routines; (3) VK (Visual Kernel), an execution-animation tool with source-code clickback; and (4) Tally, a tool for statistical analysis of execution profiles. Currently, Xinstrument can handle C and Fortran 77 programs using PVM 3.2.x; Monitor has been implemented and tested on Sun 4 systems running SunOS 4.1.2; and VK uses XIIR5 and Motif 1.2. Data and views obtained using AIMS clearly illustrate several characteristic features of executing parallel programs on networked workstations: (1) the impact of long message latencies; (2) the impact of multiprogramming overheads and associated load imbalance; (3) cache and virtual-memory effects; and (4) significant skews between workstation clocks. Interestingly, AIMS can compensate for constant skew (zero drift) by calibrating the skew between a parent and its spawned children. In addition, AIMS' skew-compensation algorithm can adjust timestamps in a way that eliminates physically impossible communications (e.g., messages going backwards in time). Our current efforts are directed toward creating new views to explain the observed performance of PVM programs. Some of the features planned for the near future include: (1) ConfigView, showing the physical topology

  8. A methodology aimed to guarantee technology continuity in health structures.

    PubMed

    Miniati, R; Dori, F; Iadanza, E; Scatizzi, L; Niccolini, F; Sarti, A

    2011-01-01

    In healthcare the importance of clinical continuity is essential for both patients life and health organization activity. Since technology continuity is having more and more importance for the service continuity, a correct management of medical devices must be guided by criteria that ensure its safe, appropriate and economical use through a well planned purchase, appropriate preventive and corrective maintenance Indeed, the aim of health technology managers is to optimize the integration of external interventions assistance and internal technical service to guarantee an efficient and cost-effective maintenance system. This paper proposes an innovative carefully thought methodology which is aimed to provide technological and procedural actions which offer support to decision makers in technology management regarding the implementation of continuity in medical services and response to technology failures and emergency events.

  9. [Mucosal healling: a realistic aim or marketing myth?].

    PubMed

    García-Sánchez, Valle; Iglesias-Flores, Eva

    2011-12-01

    The classical aim of the treatment of ulcerative colitis is to induce and maintain remission. However, this aim has not been shown to prevent long-term complications. Current treatment goals attempt to prevent complications. In some studies, healing of the intestinal mucosa has been shown to improve long-term outcomes. In ulcerative colitis, mucosal healing reduces recurrence, the risk of colorectal cancer and the need for surgery, and improves patients' quality of life. The drugs for which there is greatest evidence of their efficacy in inducing and maintaining mucosal healing are salicylates and biological agents. In the near future, endoscopic monitoring may be required to evaluate response to the treatment and decisions may have to be taken according to the persistence or disappearance of these lesions.

  10. [Aiming at the chest, but hitting the back].

    PubMed

    Zech, Wolf-Dieter; Axmann, Stefan; Siegenthaler, Lea; Kneubühl, Beat; Thali, Michael

    2011-01-01

    Gunshot injuries in the back may suggest the unjustified use of firearms. A wound in the back inflicted by a firearm should not automatically imply that the shooter aimed at the back. A previous study demonstrated that it is possible for men to turn their trunk faster than it takes for a shooter to fire or throw a hand-operated weapon. With a high speed motion camera the authors were able to demonstrate that it is also possible for women to turn their trunk fast enough, so that a shot in the back could have been aimed at the front of the body. This conclusion is also likely to apply to hand-operated or thrown weapons, since the velocity of their projectiles is considerably lower than that of firearms.

  11. Advanced Industrial Materials (AIM) program. Annual progress report. FY 1996

    SciTech Connect

    1997-04-01

    The Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven `Vision Industries` that use about 80% of industrial energy and generated about 90% of industrial wastes. These are: aluminium; chemical; forest products; glass; metal casting; refineries; and steel. OIT is working with these industries, through appropriate organizations, to develop Visions of the desired condition of each industry some 20 or 25 years in the future and then to prepare Road Maps and Implementation Plans to enable them to reach their goals. The mission of AIM has, therefore, changed to `Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.` Though AIM remains essentially a National Laboratory Program, it is necessary that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains healthy and productive, thanks to the superb investigators and Laboratory Program Managers. Separate abstracts have been indexed into the energy database for articles from this report.

  12. Action Information Management System (AIMS): a User's View

    NASA Technical Reports Server (NTRS)

    Wiskerchen, M.

    1984-01-01

    The initial approach used in establishing a user-defined information system to fulfill the needs of users at NASA Headquarters was unsuccessful in bringing this pilot endeaveor to full project status. The persistence of several users and the full involvement of the Ames Research Center were the ingredients needed to make the AIMS project a success. The lesson learned from this effort is that NASA should always work from its organizational strengths as a Headquarters-Center partnership.

  13. Action Information Management System (AIMS): a User's View

    NASA Technical Reports Server (NTRS)

    Wiskerchen, M.

    1984-01-01

    The initial approach used in establishing a user-defined information system to fulfill the needs of users at NASA Headquarters was unsuccessful in bringing this pilot endeaveor to full project status. The persistence of several users and the full involvement of the Ames Research Center were the ingredients needed to make the AIMS project a success. The lesson learned from this effort is that NASA should always work from its organizational strengths as a Headquarters-Center partnership.

  14. Triple AIM evaluation and application in advanced node

    NASA Astrophysics Data System (ADS)

    Wang, Gary C.; Lio, En Chuan; Hung, Yuting; Chen, Charlie; Wang, Sybil; Weng, Tang Chun; Lin, Bill; Yu, Chun Chi

    2016-03-01

    A novel method on advanced node for IBO (Image Based Overlay) data extraction accuracy is demonstrated in this work, and here some special design in triple-AIM (Advanced Imaging Metrology) is able to realize the approach. Since triple AIM design has 3 locations left for patterning layers insertion, a new design with 2 layers locations, location-A (inner) and location-B (middle), are generated by 1st pattering, i.e. once lithography exposure, and the 2 marks grouping are formed on dielectric through lithography and etching process with a predetermined overlay "zero offset" through original mask layout design, as illustrated in Fig. (1). And then, as following top photo resist layer, assumed location-C (outer), lithography patterning process, PR coating, exposure and development complete, full triple-AIM patterns is generated, and 3 sets of overlay data could be obtained, A to B, C to B, C to A. Through re-calculating the overlay raw data of current (2nd patterning layer) to previous (1st patterning layer) layer by averaging [C to B] and [C to A], then theoretically the data extraction of sites would be more accuracy, since the variation of local marks signal, induced by inline process instability, could be minimized through the raw data averaging procedure. Moreover, from raw data [A to B], an extra monitor function for detections of the inline process variation, marks selection and recipe setting optimization could be obtained, since marks in [A] and [BB] locations are both generated in 1st patterning, and with the target "zero". So if the raw data [A to BB] is bigger or smaller than "zero" in some degree, there should be some process issue or marks condition setting error in triple-AIM design.

  15. Explanation in Biology: Reduction, Pluralism, and Explanatory Aims

    NASA Astrophysics Data System (ADS)

    Brigandt, Ingo

    2013-01-01

    This essay analyzes and develops recent views about explanation in biology. Philosophers of biology have parted with the received deductive-nomological model of scientific explanation primarily by attempting to capture actual biological theorizing and practice. This includes an endorsement of different kinds of explanation (e.g., mathematical and causal-mechanistic), a joint study of discovery and explanation, and an abandonment of models of theory reduction in favor of accounts of explanatory reduction. Of particular current interest are philosophical accounts of complex explanations that appeal to different levels of organismal organization and use contributions from different biological disciplines. The essay lays out one model that views explanatory integration across different disciplines as being structured by scientific problems. I emphasize the philosophical need to take the explanatory aims pursued by different groups of scientists into account, as explanatory aims determine whether different explanations are competing or complementary and govern the dynamics of scientific practice, including interdisciplinary research. I distinguish different kinds of pluralism that philosophers have endorsed in the context of explanation in biology, and draw several implications for science education, especially the need to teach science as an interdisciplinary and dynamic practice guided by scientific problems and explanatory aims.

  16. Electrostatic steering and beamlet aiming in large neutral beam injectors

    SciTech Connect

    Veltri, P. Chitarin, G.; Marcuzzi, D.; Sartori, E.; Serianni, G.; Sonato, P.; Cavenago, M.

    2015-04-08

    Neutral beam injection is the main method for plasma heating in magnetic confinement fusion devices. In high energy injector (E>100 keV/amu), neutrals are obtained with reasonable efficiency by conversion of negative ions (H- or D-) via electron detachment reactions. In the case of ITER injectors, which shall operate at 1 MeV, a total ion current of ∼ 40 A is required to satisfy the heating power demand. Gridded electrodes are therefore used in the accelerator, so that 1280 negative ion beamlets are accelerated together. A carefully designed aiming system is required to control the beamlet trajectories, and to deliver their power on a focal point located several meters away from the beam source. In nowadays injectors, the aiming is typically obtained by aperture offset technique or by grid shaping. This paper discuss an alternative concept of beamlets aiming, based on an electrostatic ”steerer” to be placed at the end of the accelerator. A feasibility study of this component is also presented, and its main advantages and drawbacks with respect to other methods are discussed.

  17. Electrostatic steering and beamlet aiming in large neutral beam injectors

    NASA Astrophysics Data System (ADS)

    Veltri, P.; Cavenago, M.; Chitarin, G.; Marcuzzi, D.; Sartori, E.; Serianni, G.; Sonato, P.

    2015-04-01

    Neutral beam injection is the main method for plasma heating in magnetic confinement fusion devices. In high energy injector (E>100 keV/amu), neutrals are obtained with reasonable efficiency by conversion of negative ions (H- or D-) via electron detachment reactions. In the case of ITER injectors, which shall operate at 1 MeV, a total ion current of ˜ 40 A is required to satisfy the heating power demand. Gridded electrodes are therefore used in the accelerator, so that 1280 negative ion beamlets are accelerated together. A carefully designed aiming system is required to control the beamlet trajectories, and to deliver their power on a focal point located several meters away from the beam source. In nowadays injectors, the aiming is typically obtained by aperture offset technique or by grid shaping. This paper discuss an alternative concept of beamlets aiming, based on an electrostatic "steerer" to be placed at the end of the accelerator. A feasibility study of this component is also presented, and its main advantages and drawbacks with respect to other methods are discussed.

  18. An automated model-based aim point distribution system for solar towers

    NASA Astrophysics Data System (ADS)

    Schwarzbözl, Peter; Rong, Amadeus; Macke, Ansgar; Säck, Jan-Peter; Ulmer, Steffen

    2016-05-01

    Distribution of heliostat aim points is a major task during central receiver operation, as the flux distribution produced by the heliostats varies continuously with time. Known methods for aim point distribution are mostly based on simple aim point patterns and focus on control strategies to meet local temperature and flux limits of the receiver. Lowering the peak flux on the receiver to avoid hot spots and maximizing thermal output are obviously competing targets that call for a comprehensive optimization process. This paper presents a model-based method for online aim point optimization that includes the current heliostat field mirror quality derived through an automated deflectometric measurement process.

  19. A Study on Estimating the Aiming Angle Error of Millimeter Wave Radar for Automobile

    NASA Astrophysics Data System (ADS)

    Kuroda, Hiroshi; Okai, Fumihiko; Takano, Kazuaki

    The 76GHz millimeter wave radar has been developed for automotive application such as ACC (Adaptive Cruise Control) and CWS (Collision Warning System). The radar is FSK (Frequency Shift Keying) monopulse type. The radar transmits 2 frequencies in time-duplex manner, and measures distance and relative speed of targets. The monopulse feature detects the azimuth angle of targets without a scanning mechanism. Conventionally a radar unit is aimed mechanically, although self-aiming capability, to detect and correct the aiming angle error automatically, has been required. The new algorithm, which estimates the aiming angle error and vehicle speed sensor error simultaneously, has been proposed and tested. The algorithm is based on the relationship of relative speed and azimuth angle of stationary objects, and the least squares method is used for calculation. The algorithm is applied to measured data of the millimeter wave radar, resulting in aiming angle estimation error of less than 0.6 degree.

  20. Pulse Response Measurement Aiming for Locating Water Tree Degradation in XLPE Cables

    NASA Astrophysics Data System (ADS)

    Hiei, Susumu; Hozumi, Naohiro; Kurihara, Takashi; Okamoto, Tatsuki; Uchida, Katsumi; Tsuji, Taizo

    Water treeing is a degradation mode of power cable with polymeric insulation. A water tree is composed of small droplets filled with water. As the conductivity in water tree is very high, it leads to dielectric breakdown when it grows up. As inside of the water tree is filled with trap sites, it is polarized with a certain distribution of relaxation time when a DC poling voltage is applied. Although its depolarization process after removing the poling voltage is determined by ambient temperature, applying a “depolarizing voltage” with the opposite polarity can accelerate the process. If a short pulse propagating through the cable is employed as a depolarization voltage, we may locate the water tree through looking at the time-resolved pulse response. This would lead to a diagnosing method with spatial resolution. In order to retain 100 m of spatial resolution, the response should be as sharp as 1 μs. As a preliminary study, a coaxial communication cable was aged to form water trees. A DC poling voltage was applied followed by a pulse voltage with opposite polarity. The rising time of the pulse was several hundreds of microseconds. A sharp pulse current response with 50 μs in width was observed, suggesting that a rapid depolarization took place. No such response was seen when the cable specimen was not aged. We concluded that the technique is quite feasible. As the response was found to be as quick as several microseconds, an experiment using 405 m-long cable, with 5 m of degraded length in the middle, was performed. It was shown that the degraded point was successfully located.