Sample records for accelerated weathering chambers

  1. Comparison of pore space textural characteristics of natural stone exposed to real weathering environment and/or subjected to accelerated weathering tests: implications for durability assessment

    NASA Astrophysics Data System (ADS)

    Prikryl, Richard; Weishauptová, Zuzana

    2017-04-01

    One of the key questions in the debate on durability of natural stone is related to the relevance of accelerated weathering tests for durability assessments, specifically whether similar material responses can be achieved? In the recent study, specimens of opuka stone (extremely fine-grained clayey-calcareous silicite) was subjected to accelerated weathering tests in a climatic chamber (sulphur dioxide atmosphere, freezing/thawing). After completion of certain number of cycles, pore space textural characteristics by means of mercury porosimetry were studied. These data were compared with porosimetric data obtained from a piece of stone, sampled from a carved stone altar located in the interior of the St. Vitus Cathedral (Prague, Czech Republic) which was affected by 150-years lasting indoor decay processes (cyclic themohygric stresses due to variable indoor atmospheric conditions). Interestingly, the pore space textural characteristics of these two sets of specimens are closely related and show some distinct features different from fresh, non-weathered material. Our observation therefore supports relevance of some accelerated weathering simulations; however, conditions of these simulations must be based on parameters of real environment.

  2. Accelerated laboratory weathering of acrylic lens materials

    NASA Astrophysics Data System (ADS)

    Arndt, Thomas; Richter, Steffen; Kogler, René; Pasierb, Mike; Walby, Christopher

    2015-09-01

    Flat samples from various poly(methyl methacrylate) (PMMA) formulations were subjected to outdoor weathering in Arizona and Florida, EMMAQUA® accelerated outdoor weathering, and two accelerated laboratory weathering procedures at 3 Sun irradiance which, imitate dry (Arizona) and wet (Florida) conditions. The main mode of degradation is yellowing and not the generation of haze for any weathering procedure within the investigated radiant exposure. Higher UV absorber concentrations lead to smaller changes in optical properties and in the resulting relative concentrator photovoltaic (CPV) module efficiencies. Comparison of sample properties after various weathering procedures reveals that the influence of weathering factors other than radiant exposure depends on the sample as well.

  3. Accelerated Solar-UV Test Chamber

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Laue, E. G.

    1984-01-01

    Medium-pressure mercury-vapor lamps provide high ratio of ultraviolet to total power. Chamber for evaluating solar-ultraviolet (UV) radiation damage permits accelerated testing without overheating test specimens.

  4. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOEpatents

    Danby, Gordon T.; Jackson, John W.

    1991-01-01

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.

  5. Accelerated weathering of fire-retardant-treated wood for fire testing

    Treesearch

    Robert H. White

    2009-01-01

    Fire-retardant-treated products for exterior applications must be subjected to actual or accelerated weathering prior to fire testing. For fire-retardant-treated wood, the two accelerated weathering methods have been Method A and B of ASTM D 2898. The rain test is Method A of ASTM D 2898. Method B includes exposures to ultraviolet (UV) sunlamps in addition to water...

  6. Characterization of Vinyl Ester Composites Filled with Carbonized Jatropha seed shell: effect of accelerated weathering

    NASA Astrophysics Data System (ADS)

    Sri Aprilia, N. A.; Khalil, H. P. S. Abdul; Amin, Amri; Meurah Rosnelly, Cut; Fathanah, Ummi; Mariana

    2018-05-01

    The effect of accelerated weathering test of carbonized jatropha seed shell filled vinyl ester biocomposites was investigated. In this study, four loading of carbonized jatropha seed shell and one without loading of vinyl ester biocomposites were used. The samples exposure at several circles time in QUV chamber. The durability of vinyl ester biocomposites filled carbonized jatropha seed shell changes in mechanical properties and weight loss during exposure in UV and condensation. The tensile test and flexural indicated decrease with increasing of carbonized jatropha seed shell loading. The SEM fracture surface of biocomposites looks rough and some carbonized out of the matrix.

  7. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOEpatents

    Danby, G.T.; Jackson, J.W.

    1990-03-19

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations (dB/dt) in the particle beam.

  8. Durability of anti-graffiti coatings on stone: natural vs accelerated weathering.

    PubMed

    Carmona-Quiroga, Paula M; Jacobs, Robert M J; Martínez-Ramírez, Sagrario; Viles, Heather A

    2017-01-01

    Extending the use of novel anti-graffiti coatings to built heritage could be of particular interest providing the treatments are efficient enough in facilitating graffiti removal and long-lasting to maintain their protective properties without interfering with the durability of the substrates. However, studies of the durability of these coatings are scarce and have been mainly carried out under accelerated weathering conditions, the most common practice for assessing the durability of materials but one that does not reproduce accurately natural working conditions. The present study aimed to assess the durability of the anti-graffiti protection afforded by two anti-graffiti treatments (a water dispersion of polyurethane with a perfluoropolyether backbone and a water based crystalline micro wax) on Portland limestone and Woodkirk sandstone after 1 year of outdoor exposure in the South of England with periodic painting and cleaning episodes taking place. A parallel study under artificial weathering conditions in a QUV chamber for 2000 hours was also carried out. Changes to the coatings were assessed by measuring colour, gloss, water-repellency, roughness and microstructure, the latter through micro-Raman and optical microscope observations, periodically during the experiments. The results show that both anti-graffiti treatments deteriorated under both artificial and natural weathering conditions. For the polyurethane based anti-graffiti treatment, artificial ageing produced more deterioration than 1 year of outdoor exposure in the south of England due to loss of adhesion from the stones, whereas for micro wax coating there were no substantial differences between the two types of weathering.

  9. Durability of anti-graffiti coatings on stone: natural vs accelerated weathering

    PubMed Central

    Jacobs, Robert M. J.; Martínez-Ramírez, Sagrario; Viles, Heather A.

    2017-01-01

    Extending the use of novel anti-graffiti coatings to built heritage could be of particular interest providing the treatments are efficient enough in facilitating graffiti removal and long-lasting to maintain their protective properties without interfering with the durability of the substrates. However, studies of the durability of these coatings are scarce and have been mainly carried out under accelerated weathering conditions, the most common practice for assessing the durability of materials but one that does not reproduce accurately natural working conditions. The present study aimed to assess the durability of the anti-graffiti protection afforded by two anti-graffiti treatments (a water dispersion of polyurethane with a perfluoropolyether backbone and a water based crystalline micro wax) on Portland limestone and Woodkirk sandstone after 1 year of outdoor exposure in the South of England with periodic painting and cleaning episodes taking place. A parallel study under artificial weathering conditions in a QUV chamber for 2000 hours was also carried out. Changes to the coatings were assessed by measuring colour, gloss, water-repellency, roughness and microstructure, the latter through micro-Raman and optical microscope observations, periodically during the experiments. The results show that both anti-graffiti treatments deteriorated under both artificial and natural weathering conditions. For the polyurethane based anti-graffiti treatment, artificial ageing produced more deterioration than 1 year of outdoor exposure in the south of England due to loss of adhesion from the stones, whereas for micro wax coating there were no substantial differences between the two types of weathering. PMID:28231301

  10. Accelerating Climate and Weather Simulations through Hybrid Computing

    NASA Technical Reports Server (NTRS)

    Zhou, Shujia; Cruz, Carlos; Duffy, Daniel; Tucker, Robert; Purcell, Mark

    2011-01-01

    Unconventional multi- and many-core processors (e.g. IBM (R) Cell B.E.(TM) and NVIDIA (R) GPU) have emerged as effective accelerators in trial climate and weather simulations. Yet these climate and weather models typically run on parallel computers with conventional processors (e.g. Intel, AMD, and IBM) using Message Passing Interface. To address challenges involved in efficiently and easily connecting accelerators to parallel computers, we investigated using IBM's Dynamic Application Virtualization (TM) (IBM DAV) software in a prototype hybrid computing system with representative climate and weather model components. The hybrid system comprises two Intel blades and two IBM QS22 Cell B.E. blades, connected with both InfiniBand(R) (IB) and 1-Gigabit Ethernet. The system significantly accelerates a solar radiation model component by offloading compute-intensive calculations to the Cell blades. Systematic tests show that IBM DAV can seamlessly offload compute-intensive calculations from Intel blades to Cell B.E. blades in a scalable, load-balanced manner. However, noticeable communication overhead was observed, mainly due to IP over the IB protocol. Full utilization of IB Sockets Direct Protocol and the lower latency production version of IBM DAV will reduce this overhead.

  11. Effect of Reprocessing and Accelerated Weathering on Impact-Modified Recycled Blend

    NASA Astrophysics Data System (ADS)

    Ramesh, V.; Mohanty, Smita; Biswal, Manoranjan; Nayak, Sanjay K.

    2015-12-01

    Recovery of recycled polycarbonate, acrylonitrile butadiene styrene, high-impact polystyrene, and its blends from waste electrical and electronic equipment plastics products properties were enhanced by the addition of virgin polycarbonate and impact modifier. The optimized blend formulation was processed through five cycles, at processing temperature, 220-240 °C and accelerated weathering up to 700 h. Moreover, the effect of reprocessing and accelerated weathering in the physical properties of the modified blends was investigated by mechanical, thermal, rheological, and morphological studies. The results show that in each reprocessing cycle, the tensile strength and impact strength decreased significantly and the similar behavior has been observed from accelerated weathering. Subsequently, the viscosity decreases and this decrease becomes the effect of thermal and photo-oxidative degradation. This can be correlated with FTIR analysis.

  12. Accelerated laboratory weathering of acrylic lens materials

    NASA Astrophysics Data System (ADS)

    Arndt, Thomas; Richter, Steffen; Kogler, René; Pasierb, Mike; Walby, Christopher

    2014-09-01

    Flat samples from various PMMA formulations subjected to accelerated laboratory weathering in an "Atlas Xenotest Alpha +" weathering device operating at 3 Sun irradiance remain transparent after 6.48GJ/m2 radiant exposure (300 - 400nm). Transmittance is reduced and yellowness index increases. However, the amount of change depends largely on the PMMA formulation. Higher UV absorber concentrations lead to smaller changes in optical properties. Based on a model of CPV efficiency for a particular power train, relative losses of efficiency are between 1 and 28%. Performance regarding these properties can be linked to the UV absorber type and concentrations used.

  13. The influence of air humidity on an unsealed ionization chamber in a linear accelerator.

    PubMed

    Blad, B; Nilsson, P; Knöös, T

    1996-11-01

    The safe and accurate delivery of the prescribed absorbed dose is the central function of the dose monitoring and beam stabilization system in a medical linear accelerator. The absorbed dose delivered to the patient during radiotherapy is often monitored by a transmission ionization chamber. Therefore it is of utmost importance that the chamber behaves correctly. We have noticed that the sensitivity of an unsealed chamber in a Philips SL linear accelerator changes significantly, especially during and after the summer season. The reason for this is probably a corrosion effect of the conductive plates in the chamber due to the increased relative humidity during hot periods. We have found that the responses of the different ion chamber plates change with variations in air humidity and that they do not return to their original values when the air humidity is returned to ambient conditions.

  14. Environmental aging in polycrystalline-Si photovoltaic modules: comparison of chamber-based accelerated degradation studies with field-test data

    NASA Astrophysics Data System (ADS)

    Lai, T.; Biggie, R.; Brooks, A.; Potter, B. G.; Simmons-Potter, K.

    2015-09-01

    Lifecycle degradation testing of photovoltaic (PV) modules in accelerated-degradation chambers can enable the prediction both of PV performance lifetimes and of return-on-investment for installations of PV systems. With degradation results strongly dependent on chamber test parameters, the validity of such studies relative to fielded, installed PV systems must be determined. In the present work, accelerated aging of a 250 W polycrystalline silicon module is compared to real-time performance degradation in a similar polycrystalline-silicon, fielded, PV technology that has been operating since October 2013. Investigation of environmental aging effects are performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability providing illumination uniformity of 98% over a 2 x 1.6 m area. Time-dependent, photovoltaic performance (J-V) is evaluated over a recurring, compressed night-day cycle providing representative local daily solar insolation for the southwestern United States, followed by dark (night) cycling. This cycle is synchronized with thermal and humidity environmental variations that are designed to mimic, as closely as possible, test-yard conditions specific to a 12 month weather profile for a fielded system in Tucson, AZ. Results confirm the impact of environmental conditions on the module long-term performance. While the effects of temperature de-rating can be clearly seen in the data, removal of these effects enables the clear interpretation of module efficiency degradation with time and environmental exposure. With the temperature-dependent effect removed, the normalized efficiency is computed and compared to performance results from another panel of similar technology that has previously experienced identical climate changes in the test yard. Analysis of relative PV module efficiency degradation for the chamber-tested system shows good comparison to the field-tested system with ~2.5% degradation following

  15. 46 CFR 160.072-5 - Accelerated weathering test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... submersion in 5% by weight sodium chloride solution for 2 hours followed immediately by storage at 95% (±5... less than 24 hours. (d) The flag fails the accelerated weathering test if (1) After conditioning, the... bright red/orange color, (4) The disc and square images no longer meet the requirements of § 160.072-3(a...

  16. Effect of processing method on accelerated weathering of wood-flour/HDPE composites

    Treesearch

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2003-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  17. Ultra-accelerated natural sunlight exposure testing

    DOEpatents

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  18. Indirect check of the stability of the reference ion chamber used for accelerator output calibration

    NASA Astrophysics Data System (ADS)

    Kang, Sei-Kwon; Yoon, Jai-Woong; Park, Soah; Hwang, Taejin; Cheong, Kwang-Ho; Han, Tae Jin; Kim, Haeyoung; Lee, Me-Yeon; Kim, Kyoung Ju; Bae, Hoonsik

    2014-11-01

    A linear accelerator's output is periodically checked by using a reference ion chamber which is also periodically calibrated at the accredited standard dosimetry laboratories. We suggest a simple procedure for checking the chamber's stability between calibrations by comparison with another ion chamber. To identify the long-term stability of chambers, we collected and assessed the dose-to-water conversion factors provided by standard laboratories for three chambers during a period of four years. To develop the chamber constancy check program, we used one Farmer-type reference ion chamber FC65-G, two ion chambers (CC13a and CC13b) and one CC01 ion chamber (IBA). Under the accelerator, each chamber was placed inside the solid phantom and irradiated; the experimental configurations were identical. To check the variation in charge collection of the reference chamber, we monitored the ratios of the FC65-G values over each chamber reading. Based on the error propagation of the two chamber ratios, we estimated the uncertainty of the output calibration from the chamber variation. The calibration factors provided for the three chambers showed 0.04 ˜ 0.12% standard deviations during four years. For procedure development, the reading ratios of FC65-G over CCxx showed very good stability; the ratios of FC65-G over CC13a, CC13b and CC01 varied less than 0.059, 0.087 and 0.248%, respectively, over five measurements. By ascribing possible uncertainties of the ratio to the reference chamber alone, we could conservatively check the stability of the reference chamber for treatment safety. An extension of the chamber calibration period was also evaluated. In conclusion, we designed a stability check procedure for the reference chamber based on a reading ratio of two chambers. This could help the user assess the chamber stability between periodic chamber calibration, and the associated patient treatment could be carried out with enhanced safety.

  19. UV exposure in artificial and natural weathering: A comparative study

    NASA Astrophysics Data System (ADS)

    Heikkilä, A.; Kazadzis, S.; Meinander, O.; Vaskuri, A.; Kärhä, P.; Mylläri, V.; Syrjälä, S.; Koskela, T.

    2017-02-01

    We report on a study focusing on UV exposure conditions in three different types of chambers used for accelerated ageing of materials. The first chamber is equipped with four 300-W UVA/UVB mercury vapour lamps (Ultra-Vitalux/Osram). The second chamber uses four 40-W UVA fluorescent lamps (QUV-340/Q-Lab). The third chamber is Weather-Ometer Ci3000+ from Atlas with a 4500-W xenon arc lamp. UV irradiance prevailing in each chamber was measured using Bentham DM150 double monochromator spectroradiometer. The results were compared to measurements of solar spectral UV irradiance at Jokioinen, Finland, with a Brewer MkIII double monochromator spectrophotometer. The spectral shapes of the exposing UV radiation in the different chambers were found to notably differ from each other and from the solar UV spectrum. Both spatial inhomogeneities and temporal variability caused by various factors, like the ageing of the lamps, were detected. The effects were found to strongly depend on wavelength of the exposing UV radiation. The findings of this study underline the necessity of careful characterization of the UV exposure conditions provided by the facilities used in accelerated testing of materials.

  20. Changes in wood flour/HDPE composites after accelerated weathering with and without water spray

    Treesearch

    Nicole M. Stark

    2005-01-01

    Wood-plastic lumber is promoted as a low-maintenance high-durability product. After weathering, however, wood-plasticcomposites (WPCs) often fide and lose mechanical properties. In the first part ofthis study, 50%wood-flour-filled high-density polyethylene (HDPE) composite samples were injection molded or extruded. Composites were exposed to two accelerated weathering...

  1. Analysis on weathering characteristics of volcanic rocks in Dokdo, Korea based on accelerated weatehring experiments

    NASA Astrophysics Data System (ADS)

    Woo, Ik; Song, Won-Kyong; Kim, Bok-Chul; Kang, Jinseok

    2010-05-01

    Dokdo consists of small volcanic islands located in the southern part of the East Sea. Accelerated weathering tests was performed to examine the physico-mechanical characteristics of volcanic rocks in Dokdo. Rock core specimens of trachyandesite, andesitic dyke and ash tuff were prepared, and double soxhlet extractors(DSE) and peristatic pumps were used for accelerating the weathering processes. The DSE was designed to perform cyclic leaching tests for rock core specimen using distilled water at seventy degrees centigrade. The core specimens which are classified according to pre-test weathering grades placed in the lower part of the DSE, and periodically exposed to hot distilled water at every ninety minutes. On the other hand the peristatic pumps were utilized to induce leaching by distilled or brine water at normal temperature. The physico-mechanical property changes including rock surface appearance, microscopic structure and rock strength were analyzed with the results obtained from both experiments performed for 120 days. The conducted research in this study have shown that the methodologies of artificial weathering experiments have strong capability to understand the weathering characteristics of the rocks effectively.

  2. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    DOEpatents

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  3. Ultra-accelerated natural sunlight exposure testing facilities

    DOEpatents

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2003-08-12

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS to deliver a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in chamber means that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  4. Copper leaching of MSWI bottom ash co-disposed with refuse: effect of short-term accelerated weathering.

    PubMed

    Su, Lianghu; Guo, Guangzhai; Shi, Xinlong; Zuo, Minyu; Niu, Dongjie; Zhao, Aihua; Zhao, Youcai

    2013-06-01

    Co-disposal of refuse with municipal solid waste incinerator (MSWI) bottom ash (IBA) either multi-layered as landfill cover or mixed with refuse could pose additional risk to the environment because of enhanced leaching of heavy metals, especially Cu. This study applied short-term accelerated weathering to IBA, and monitored the mineralogical and chemical properties of IBA during the weathering process. Cu extractability of the weathered IBA was then evaluated using standard leaching protocols (i.e. SPLP and TCLP) and co-disposal leaching procedure. The results showed that weathering had little or no beneficial effect on Cu leaching in SPLP and TCLP, which can be explained by the adsorption and complexation of Cu with DOM. However, the Cu leaching of weathered IBA was reduced significantly when situated in fresh simulated landfill leachate. This was attributed to weakening Cu complexation with fulvic acid or hydrophilic fractions and/or intensifying Cu absorption to neoformed hydr(oxide) minerals in weathered IBA. The amount of total leaching Cu and Cu in free or labile complex fraction (the fraction with the highest mobility and bio-toxicity) of the 408-h weathered IBA were remarkably decreased by 86.3% and 97.6% in the 15-day co-disposal leaching test. Accelerated weathering of IBA may be an effective pretreatment method to decrease Cu leaching prior to its co-disposal with refuse. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Effect of TiO2-Crystal Forms on the Photo-Degradation of EVA/PLA Blend Under Accelerated Weather Testing

    NASA Astrophysics Data System (ADS)

    Van Cong, Do; Trang, Nguyen Thi Thu; Giang, Nguyen Vu; Lam, Tran Dai; Hoang, Thai

    2016-05-01

    Photo-degradation of poly (ethylene-co-vinyl acetate) (EVA)/poly (lactic acid) (PLA) blend and EVA/PLA/TiO2 nanocomposites was carried out under accelerated weather testing conditions by alternating cycles of ultraviolet (UV) light and moisture at controlled and elevated temperatures. The characters, properties, and morphology of these materials before and after accelerated weather testing were determined by Fourier transform infrared spectroscopy, colour changes, viscosity, tensile test, thermogravimetric analysis, and field emission scanning electron microscopy. The increases in the content of oxygen-containing groups, colour changes; the decreases in viscosity, tensile properties, and thermal stability of these materials after accelerated weather testing are the evidence for the photo-degradation of the blend and nanocomposites. After accelerated weather testing, the appearance of many micro-holes and micro-pores on the surface of the collected samples was observed. The photo-degradation degree of the nanocomposites depended on the TiO2-crystal form. Rutile TiO2 do not enhance the degradation, but anatase and mixed crystals TiO2 nanoparticles promoted the degradation of the nanocomposites. Particularly, the mixed crystals TiO2 nanoparticles showed the highest photo-catalytic activity of the nanocomposites.

  6. NOTE: Calibration of low-energy electron beams from a mobile linear accelerator with plane-parallel chambers using both TG-51 and TG-21 protocols

    NASA Astrophysics Data System (ADS)

    Beddar, A. S.; Tailor, R. C.

    2004-04-01

    A new approach to intraoperative radiation therapy led to the development of mobile linear electron accelerators that provide lower electron energy beams than the usual conventional accelerators commonly encountered in radiotherapy. Such mobile electron accelerators produce electron beams that have nominal energies of 4, 6, 9 and 12 MeV. This work compares the absorbed dose output calibrations using both the AAPM TG-51 and TG-21 dose calibration protocols for two types of ion chambers: a plane-parallel (PP) ionization chamber and a cylindrical ionization chamber. Our results indicate that the use of a 'Markus' PP chamber causes 2 3% overestimation in dose output determination if accredited dosimetry-calibration laboratory based chamber factors \\big(N_{{\\rm D},{\\rm w}}^{{}^{60}{\\rm Co}}, N_x\\big) are used. However, if the ionization chamber factors are derived using a cross-comparison at a high-energy electron beam, then a good agreement is obtained (within 1%) with a calibrated cylindrical chamber over the entire energy range down to 4 MeV. Furthermore, even though the TG-51 does not recommend using cylindrical chambers at the low energies, our results show that the cylindrical chamber has a good agreement with the PP chamber not only at 6 MeV but also down to 4 MeV electron beams.

  7. Development of a standard accelerated weathering test for aggregates using dimethyl sulfoxide (DMSO) : final report.

    DOT National Transportation Integrated Search

    1986-09-01

    A standard accelerated weathering test using Dimethyl Sulfoxide (DMSO) was developed to simulate the chemical degradation of basaltic rocks. After a thorough study of the parameters affecting the current procedure, such as container geometry, aggrega...

  8. Accelerated weathering of wood surfaces coated with multifunctional allkoxysilanes by sol-gel deposition

    Treesearch

    Mandla A. Tshabalala; John E. Gangstad

    2003-01-01

    Accelerated weathering of wood surfaces coated with hexadecyltrimethoxysilane (HDTMOS) in the presence of methyltrimethoxysilane (MTMOS) by the sol-gel process was investigated. The sol-gel process allowed the deposition of a covalently bound thin layer of polysiloxane networks on the wood surface that was resistant to water sorption and water leaching. The rate of...

  9. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, Greg H.; Knauss, Kevin G.; Langer, William H.; Caldeira,

    2004-01-01

    We evaluate accelerated weathering of limestone (AWL: CO2 + CaCO3 + H2O=> Ca2+ + 2HCO3-) as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology. With access to seawater and limestone being essential to this approach, significant limestone resources are close to most CO2-emitting power plants along the coastal US. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could be used as an inexpensive source of AWL carbonate. Under such circumstances CO2 mitigation cost could be as low as $3-$4/tonne. More broadly, 10-20% of US point-source CO2 emissions could be treated at $20-$30/tonne CO2. AWL end-solution disposal in the ocean would significantly reduce effects on ocean pH and carbonate chemistry relative to those caused by direct atmospheric or ocean CO2 disposal. Indeed, the increase in ocean Ca2+ and bicarbonate offered by AWL should enhance growth of corals and other calcifying marine organisms.

  10. Surface chemistry and mechanical property changes of wood-flour/high-density-polyethylene composites after accelerated weathering

    Treesearch

    Nicole M. Stark; Laurent M. Matuana

    2004-01-01

    Although wood–plastic composites have become more accepted and used in recent years and are promoted as low-maintenance, high-durability building products, they do experience a color change and a loss in mechanical properties with accelerated weathering. In this study, we attempted to characterize the modulus-of-elasticity (MOE) loss of photostabilized high- density...

  11. Rapid electron beam accelerator (REBA-tron)

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

    Kapetanakos, C.A.; Sprangle, P.A.; Dialetis, D.

    1986-03-05

    This invention comprises a particle accelerator with a toroidal vacuum chamber, an injector for injecting a charged-paticle beam into the chamber and an exit port to extract the accelerated particle beam. A toroidal magnetic field to confine the beam in the chamber is generated by a set of coils with their axis along the minor axis of the chamber and by two twisted wires that carry current in the same direction wrapped around the chamber. The two twisted wires also generate a torsatron magnetic field that controls the minor radius of the beam. A time-varying magnetic field is generated bymore » two concentric cylindrical plates surrounding the chamber. A convoluted transmission line generates a localized electric field in the chamber to accelerate the beam.« less

  12. Measurement of changes in linear accelerator photon energy through flatness variation using an ion chamber array

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

    Gao Song; Balter, Peter A.; Rose, Mark

    2013-04-15

    Purpose: To compare the use of flatness versus percent depth dose (PDD) for determining changes in photon beam energy for a megavoltage linear accelerator. Methods: Energy changes were accomplished by adjusting the bending magnet current by up to {+-}15% in 5% increments away from the value used clinically. Two metrics for flatness, relative flatness in the central 80% of the field (Flat) and average maximum dose along the diagonals normalized by central axis dose (F{sub DN}), were measured using a commercially available planner ionization chamber array. PDD was measured in water at depths of 5 and 10 cm in 3more » Multiplication-Sign 3 cm{sup 2} and 10 Multiplication-Sign 10 cm{sup 2} fields using a cylindrical chamber. Results: PDD was more sensitive to changes in energy when the beam energy was increased than when it was decreased. For the 18-MV beam in particular, PDD was not sensitive to energy reductions below the nominal energy. The value of Flat was found to be more sensitive to decreases in energy than to increases, with little sensitivity to energy increases above the nominal energy for 18-MV beams. F{sub DN} was the only metric that was found to be sensitive to both increases and reductions of energy for both the 6- and 18-MV beams. Conclusions: Flatness based metrics were found to be more sensitive to energy changes than PDD, In particular, F{sub DN} was found to be the most sensitive metric to energy changes for photon beams of 6 and 18 MV. The ionization chamber array allows this metric to be conveniently measured as part of routine accelerator quality assurance.« less

  13. Surface degradation of polymer insulators under accelerated climatic aging in weather-ometer

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

    Xu, G.; McGrath, P.B.; Burns, C.W.

    1996-12-31

    Climatic aging experiments were conducted on two types of outdoor polymer insulators by using a programmable weather-ometer. The housing materials for the insulators were silicone rubber (SR) and ethylene propylene diene monomer (EPDM). The accelerated aging stresses were comprised of ultraviolet radiation, elevated temperature, temperature cycling, thermal shock and high humidity. Their effects on the insulator surface conditions and electrical performance wee examined through visual inspection and SEM studies, contact angle measurements, thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS) analysis, and 50% impulse flashover voltage tests. The results showed a significant damage on the insulator surface caused by some ofmore » the imposed aging stresses. The EDS analysis suggested a photooxidation process that happened on the insulator surface during the aging period.« less

  14. The Addition of Graphene to Polymer Coatings for Improved Weathering

    DOE PAGES

    Nuraje, Nurxat; Khan, Shifath I.; Misak, Heath; ...

    2013-01-01

    Graphene nanoflakes in different weight percentages were added to polyurethane top coatings, and the coatings were evaluated relative to exposure to two different experimental conditions: one a QUV accelerated weathering cabinet, while the other a corrosion test carried out in a salt spray chamber. After the exposure tests, the surface morphology and chemical structure of the coatings were investigated via atomic force microscopy (AFM) and Fourier transform infrared (FTIR) imaging. Our results show that the addition of graphene does in fact improve the resistance of the coatings against ultraviolet (UV) degradation and corrosion. It is believed that this process willmore » improve the properties of the polyurethane top coating used in many industries against environmental factors.« less

  15. Accelerator system and method of accelerating particles

    NASA Technical Reports Server (NTRS)

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  16. Three chamber negative ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.; Hiskes, John R.

    1985-01-01

    A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

  17. Weatherization and Intergovernmental Program - Portal to New Jobs in Home Weatherization (Green Jobs)

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

    None

    2010-04-01

    Expanding training opportunities in the weatherization of buildings will accelerate learning and provide a direct path for many Americans to find jobs in the clean energy field. The National Weatherization Training Portal (NWTP), which is now in the final stages of testing, features multi-media, interactive, self-paced training modules.

  18. Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, William H.; San, Juan A.; Rau, Greg H.; Caldeira, Ken

    2009-01-01

    Large amounts of limestone fines co-produced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point sources such as cement manufacturing. AWL reactants are readily available, inexpensive and environmentally benign. Waste CO2 is hydrated with water to produce carbonic acid. This reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate.

  19. Accelerated azo dye degradation and concurrent hydrogen production in the single-chamber photocatalytic microbial electrolysis cell.

    PubMed

    Hou, Yanping; Zhang, Renduo; Yu, Zebin; Huang, Lirong; Liu, Yuxin; Zhou, Zili

    2017-01-01

    The single-chamber microbial electrolysis cell constructed with a TiO 2 -coated photocathode, termed photocatalytic microbial electrolysis cell (PMEC), was developed to accelerate methyl orange (MO) degradation and concurrent hydrogen (H 2 ) recovery under UV irradiation. Results showed that faster MO decolorization rates were achieved from the PMEC compared with those without UV irradiation or with open circuit. With increase of MO concentrations (acetate as co-substrate) from 50 to 300mg/L at an applied voltage of 0.8V, decolorization efficiencies decreased from 98% to 76% within 12h, and cyclic H 2 production declined from 113 to 68mL. As the possible mechanism of MO degradation, bioelectrochemical reduction, co-metabolism reduction, and photocatalysis were involved; and degradation intermediates (mainly sulfanilic acid and N,N-dimethylaniline) were further degraded by OH generated from photocatalysis. This makes MO mineralization be possible in the single-chamber PMEC. Hence, the PMEC is a promising system for dyeing wastewater treatment and simultaneous H 2 production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Estimation of absorbed dose in clinical radiotherapy linear accelerator beams: Effect of ion chamber calibration and long-term stability

    PubMed Central

    Ravichandran, Ramamoorthy; Binukumar, Johnson Pichy; Davis, Cheriyathmanjiyil Antony

    2013-01-01

    The measured dose in water at reference point in phantom is a primary parameter for planning the treatment monitor units (MU); both in conventional and intensity modulated/image guided treatments. Traceability of dose accuracy therefore still depends mainly on the calibration factor of the ion chamber/dosimeter provided by the accredited Secondary Standard Dosimetry Laboratories (SSDLs), under International Atomic Energy Agency (IAEA) network of laboratories. The data related to Nd,water calibrations, thermoluminescent dosimetry (TLD) postal dose validation, inter-comparison of different dosimeter/electrometers, and validity of Nd,water calibrations obtained from different calibration laboratories were analyzed to find out the extent of accuracy achievable. Nd,w factors in Gray/Coulomb calibrated at IBA, GmBH, Germany showed a mean variation of about 0.2% increase per year in three Farmer chambers, in three subsequent calibrations. Another ion chamber calibrated in different accredited laboratory (PTW, Germany) showed consistent Nd,w for 9 years period. The Strontium-90 beta check source response indicated long-term stability of the ion chambers within 1% for three chambers. Results of IAEA postal TL “dose intercomparison” for three photon beams, 6 MV (two) and 15 MV (one), agreed well within our reported doses, with mean deviation of 0.03% (SD 0.87%) (n = 9). All the chamber/electrometer calibrated by a single SSDL realized absorbed doses in water within 0.13% standard deviations. However, about 1-2% differences in absorbed dose estimates observed when dosimeters calibrated from different calibration laboratories are compared in solid phantoms. Our data therefore imply that the dosimetry level maintained for clinical use of linear accelerator photon beams are within recommended levels of accuracy, and uncertainties are within reported values. PMID:24672156

  1. Accelerating the carbon cycle: the ethics of enhanced weathering.

    PubMed

    Lawford-Smith, H; Currie, A

    2017-04-01

    Enhanced weathering, in comparison to other geoengineering measures, creates the possibility of a reduced cost, reduced impact way of decreasing atmospheric carbon, with positive knock-on effects such as decreased oceanic acidity. We argue that ethical concerns have a place alongside empirical, political and social factors as we consider how to best respond to the critical challenge that anthropogenic climate change poses. We review these concerns, considering the ethical issues that arise (or would arise) in the large-scale deployment of enhanced weathering. We discuss post-implementation scenarios, failures of collective action, the distribution of risk and externalities and redress for damage. We also discuss issues surrounding 'dirty hands' (taking conventionally immoral action to avoid having to take action that is even worse), whether enhanced weathering research might present a moral hazard, the importance of international governance and the notion that the implementation of large-scale enhanced weathering would reveal problematic hubris. Ethics and scientific research interrelate in complex ways: some ethical considerations caution against research and implementation, while others encourage them. Indeed, the ethical perspective encourages us to think more carefully about how, and what types of, geoengineering should be researched and implemented. © 2017 The Author(s).

  2. Accelerated weathering of tough shales : final report.

    DOT National Transportation Integrated Search

    1977-01-01

    The purpose of this study was to find or develop a test that would identify a very tough but relatively rapid weathering type of shale that has caused problems when used in embankments as rock. Eight shales, including the problem shale, were collecte...

  3. NASA Aviation Safety Program Weather Accident Prevention/weather Information Communications (WINCOMM)

    NASA Technical Reports Server (NTRS)

    Feinberg, Arthur; Tauss, James; Chomos, Gerald (Technical Monitor)

    2002-01-01

    Weather is a contributing factor in approximately 25-30 percent of general aviation accidents. The lack of timely, accurate and usable weather information to the general aviation pilot in the cockpit to enhance pilot situational awareness and improve pilot judgment remains a major impediment to improving aviation safety. NASA Glenn Research Center commissioned this 120 day weather datalink market survey to assess the technologies, infrastructure, products, and services of commercial avionics systems being marketed to the general aviation community to address these longstanding safety concerns. A market survey of companies providing or proposing to provide graphical weather information to the general aviation cockpit was conducted. Fifteen commercial companies were surveyed. These systems are characterized and evaluated in this report by availability, end-user pricing/cost, system constraints/limits and technical specifications. An analysis of market survey results and an evaluation of product offerings were made. In addition, recommendations to NASA for additional research and technology development investment have been made as a result of this survey to accelerate deployment of cockpit weather information systems for enhancing aviation safety.

  4. Zinc stable isotope fractionation upon accelerated oxidative weathering of sulfidic mine waste.

    PubMed

    Matthies, R; Krahé, L; Blowes, D W

    2014-07-15

    Accelerated oxidative weathering in a reaction cell (ASTM D 5744 standard protocol) was performed over a 33 week period on well characterized, sulfidic mine waste from the Kidd Creek Cu-Zn volcanogenic massive sulfide deposit, Canada. The cell leachate was monitored for physicochemical parameters, ion concentrations and stable isotope ratios of zinc. Filtered zinc concentrations (<0.45 μm) in the leachate ranged between 4.5 mg L(-1) and 1.9 g L(-1)-potentially controlled by pH, mineral solubility kinetics and (de)sorption processes. The zinc stable isotope ratios varied mass-dependently within +0.1 and +0.52‰ relative to IRMM 3702, and were strongly dependent on the pH (rpH-d66Zn=0.65, p<0.005, n=31). At a pH below 5, zinc mobilization was governed by sphalerite oxidation and hydroxide dissolution-pointing to the isotope signature of sphalerite (+0.1 to +0.16‰). Desorption processes resulted in enrichment of (66)Zn in the leachate reaching a maximum offset of +0.32‰ compared to the proposed sphalerite isotope signature. Over a period characterized by pH=6.1 ± 0.6, isotope ratios were significantly more enriched in (66)Zn with an offset of ≈ 0.23‰ compared to sphalerite, suggesting that zinc release may have been derived from a second zinc source, such as carbonate minerals, which compose 8 wt.% of the tailings. This preliminary study confirms the benefit of applying zinc isotopes alongside standard monitoring parameters to track principal zinc sources and weathering processes in complex multi-phase matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. The electrical performance of polymeric insulating materials under accelerated aging in a fog chamber

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

    Gorur, R.S.; Cherney, E.A.; Hackam, R.

    1988-07-01

    A comparative study of the ac (60 Hz) surface aging in a fog chamber is reported on cylindrical rod samples of high temperature vulcanized (HTV) silicone rubber and ethylene propylene diene monomer (EPDM) rubber containing various amounts of alumina trihydrate (ATH) and/or silica fillers. In low conductivity (250 ..mu..S/cm) fog, silicone rubber performed better than EPDM samples whereas in high conductivity (1000 ..mu..S/cm) fog, the order of performance was reversed. The mechanisms by which fillers impart tracking and erosion resistance to materials is discussed as influenced by the experimental conditions of the accelerated aging tests. Surface studies by ESCA (Electronmore » Spectroscopy for Chemical Analysis) demonstrate that the hydrophobicity of silicone rubber, despite the accumulation of surface contamination, can be attributed to migration of low molecular weight polymer chains and/or mobile fluids, such as silicone oil.« less

  6. Development of a neutron spectrometer using multi-wire spark chambers for the measurement of the spectra of stray neutrons in the vicinity of high energy accelerators

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

    Lim, Chun Bin

    A method of neutron spectrometry which measures the energy spectra of the stray neutrons around the high energy accelerators, roughly between 50 MeV and 300 MeV has been developed using a series of multi-wire spark chambers and polyethylene n-p converters.

  7. Limestone weathering rates accelerated by micron-scale grain detachment

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.; Levenson, Y.

    2014-12-01

    The weathering rates of carbonate rocks is often thought to be controlled by chemical dissolution, although some studies have suggested that mechanical erosion could also play an important role. Quantifying the rates of the different processes has proved challenging due to the high degree of variability encountered in both field and lab settings. To determine the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Weathering rates in fine-grained micritic limestone blocks are up to 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these higher reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained rocks in many carbonate terrains.

  8. Climate-change effects on soils: Accelerated weathering, soil carbon and elemental cycling

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

    Qafoku, Nikolla

    2015-04-01

    Climate change [i.e., high atmospheric carbon dioxide (CO2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2, and create organic carbon (C) that is either reprocessed to CO2 or stored in soils are the subject of active current investigations, with great concern over themore » influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries, identifies key research needs, and highlights opportunities offered by the climate-change effects on soils.« less

  9. Electrostatic Plasma Accelerator (EPA)

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Aston, Graeme

    1989-01-01

    The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass. The goal of the present program is to demonstrate feasibility of the EPA thruster concept through experimental and theoretical investigations of the EPA acceleration mechanism and discharge chamber performance. Experimental investigations will include operating the test bed ion (TBI) engine as an EPA thruster and parametrically varying the thruster geometry and operating conditions to quantify the electrostatic plasma acceleration effect. The theoretical investigations will include the development of a discharge chamber model which describes the relationships between the engine size, plasma properties, and overall performance. For the EPA thruster to be a viable propulsion concept, overall thruster efficiencies approaching 30% with specific impulses approaching 1000 s must be achieved.

  10. Weatherization Innovation Pilot Program (WIPP): Technical Assistance Summary

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

    Hollander, A.

    2014-09-01

    The U.S. Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) Weatherization and Intergovernmental Programs Office (WIPO) launched the Weatherization Innovation Pilot Program (WIPP) to accelerate innovations in whole-house weatherization and advance DOE's goal of increasing the energy efficiency and health and safety of low-income residences without the utilization of additional taxpayer funding. Sixteen WIPP grantees were awarded a total of $30 million in Weatherization Assistance Program (WAP) funds in September 2010. These projects focused on: including nontraditional partners in weatherization service delivery; leveraging significant non-federal funding; and improving the effectiveness of low-income weatherization through the use of newmore » materials, technologies, behavior-change models, and processes.« less

  11. Acceleration switch

    DOEpatents

    Abbin, Jr., Joseph P.; Devaney, Howard F.; Hake, Lewis W.

    1982-08-17

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  12. Acceleration switch

    DOEpatents

    Abbin, J.P. Jr.; Devaney, H.F.; Hake, L.W.

    1979-08-29

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  13. Lifetime Prediction for Degradation of Solar Mirrors using Step-Stress Accelerated Testing (Presentation)

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

    Lee, J.; Elmore, R.; Kennedy, C.

    This research is to illustrate the use of statistical inference techniques in order to quantify the uncertainty surrounding reliability estimates in a step-stress accelerated degradation testing (SSADT) scenario. SSADT can be used when a researcher is faced with a resource-constrained environment, e.g., limits on chamber time or on the number of units to test. We apply the SSADT methodology to a degradation experiment involving concentrated solar power (CSP) mirrors and compare the results to a more traditional multiple accelerated testing paradigm. Specifically, our work includes: (1) designing a durability testing plan for solar mirrors (3M's new improved silvered acrylic "Solarmore » Reflector Film (SFM) 1100") through the ultra-accelerated weathering system (UAWS), (2) defining degradation paths of optical performance based on the SSADT model which is accelerated by high UV-radiant exposure, and (3) developing service lifetime prediction models for solar mirrors using advanced statistical inference. We use the method of least squares to estimate the model parameters and this serves as the basis for the statistical inference in SSADT. Several quantities of interest can be estimated from this procedure, e.g., mean-time-to-failure (MTTF) and warranty time. The methods allow for the estimation of quantities that may be of interest to the domain scientists.« less

  14. Accelerated Weathering of Fluidized Bed Steam Reformation Material Under Hydraulically Unsaturated Conditions

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

    Pierce, Eric M.

    2007-09-16

    To predict the long-term fate of low- and high-level waste forms in the subsurface over geologic time scales, it is important to understand the behavior of the corroding waste forms under conditions the mimic to the open flow and transport properties of a subsurface repository. Fluidized bed steam reformation (FBSR), a supplemental treatment technology option, is being considered as a waste form for the immobilization of low-activity tank waste. To obtain the fundamental information needed to evaluate the behavior of the FBSR waste form under repository relevant conditions and to monitor the long-term behavior of this material, an accelerated weatheringmore » experiment is being conducted with the pressurized unsaturated flow (PUF) apparatus. Unlike other accelerated weathering test methods (product consistency test, vapor hydration test, and drip test), PUF experiments are conducted under hydraulically unsaturated conditions. These experiments are unique because they mimic the vadose zone environment and allow the corroding waste form to achieve its final reaction state. Results from this on-going experiment suggest the volumetric water content varied as a function of time and reached steady state after 160 days of testing. Unlike the volumetric water content, periodic excursions in the solution pH and electrical conductivity have been occurring consistently during the test. Release of elements from the column illustrates a general trend of decreasing concentration with increasing reaction time. Normalized concentrations of K, Na, P, Re (a chemical analogue for 99Tc), and S are as much as 1 × 104 times greater than Al, Cr, Si, and Ti. After more than 600 days of testing, the solution chemistry data collected to-date illustrate the importance of understanding the long-term behavior of the FBSR product under conditions that mimic the open flow and transport properties of a subsurface repository.« less

  15. The erosion of the beaches on the coast of Alicante: Study of the mechanisms of weathering by accelerated laboratory tests.

    PubMed

    López, I; López, M; Aragonés, L; García-Barba, J; López, M P; Sánchez, I

    2016-10-01

    One of the main problems that coasts around the world present, is the regression and erosion of beaches. However, the factors involved in these processes are unclear. In this study, the influence of sediment erosion on beach regression has been analysed. In order to do that, a three-step investigation has been carried out. Firstly, coastline variations of four Spanish beaches have been analysed. Secondly, a study on sediment position along the beach profile has been developed. Finally, the process that beach sediments undergo along the surf zone when they are hit by the incident waves has been simulated by an accelerated particle weathering test. Samples of sand and shells were subjected to this accelerated particle weathering test. Results were supplemented with those from carbonate content test, XRD, SEM and granulometric analysis. Results shows a cross-shore classification of sediments along the beach profile in which finer particles move beyond offshore limit. Besides, it was observed that sediment erosion process is divided into three sages: i) particles wear due to crashes ii) dissolution of the carbonate fraction, and iii) breakage and separation of mineral and carbonate parts of particles. All these processes lead to a reduction of particle size. The mechanism responsible of beach erosion would consist of multiples and continuous particle location exchanges along the beach profile as a consequence of grain-size decrease due to erosion. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. SU-E-T-525: Ionization Chamber Perturbation in Flattening Filter Free Beams

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

    Czarnecki, D; Voigts-Rhetz, P von; Zink, K

    2015-06-15

    Purpose: Changing the characteristic of a photon beam by mechanically removing the flattening filter may impact the dose response of ionization chambers. Thus, perturbation factors of cylindrical ionization chambers in conventional and flattening filter free photon beams were calculated by Monte Carlo simulations. Methods: The EGSnrc/BEAMnrc code system was used for all Monte Carlo calculations. BEAMnrc models of nine different linear accelerators with and without flattening filter were used to create realistic photon sources. Monte Carlo based calculations to determine the fluence perturbations due to the presens of the chambers components, the different material of the sensitive volume (air insteadmore » of water) as well as the volume effect were performed by the user code egs-chamber. Results: Stem, central electrode, wall, density and volume perturbation factors for linear accelerators with and without flattening filter were calculated as a function of the beam quality specifier TPR{sub 20/10}. A bias between the perturbation factors as a function of TPR{sub 20/10} for flattening filter free beams and conventional linear accelerators could not be observed for the perturbations caused by the components of the ionization chamber and the sensitive volume. Conclusion: The results indicate that the well-known small bias between the beam quality correction factor as a function of TPR20/10 for the flattening filter free and conventional linear accelerators is not caused by the geometry of the detector but rather by the material of the sensitive volume. This suggest that the bias for flattening filter free photon fields is only caused by the different material of the sensitive volume (air instead of water)« less

  17. Effect of accelerated weathering on surface chemistry of modified wood

    NASA Astrophysics Data System (ADS)

    Temiz, Ali; Terziev, Nasko; Eikenes, Morten; Hafren, Jonas

    2007-04-01

    In this study, the effects of UV-light irradiation and water spray on colour and surface chemistry of scots pine sapwood samples were investigated. The specimens were treated with chromated copper arsenate (CCA), a metal-free propiconazol-based formulation, chitosan, furfuryl alcohol and linseed and tall oils. The weathering experiment was performed by cycles of 2 h UV-light irradiation followed by water spray for 18 min. The changes at the surface of the weathered samples were characterised by Fourier transform infrared spectroscopy (FT-IR); colour characterizations were performed by measuring CIELab parameters. The results show that all treatment methods except chitosan treatment provided lower colour changes than the control groups after 800 h exposure in weathering test cycle, but differences between chitosan and control were also small. The lowest colour changes were found on linseed oil (full cell process) and CCA treated wood. FT-IR results show that oil treatment (linseed and tall oil) decreased the intensities of a lignin specific peak (1500-1515 cm -1). Absorption band changes at 1630-1660 cm -1 were reduced by all treatments.

  18. Reactor for simulation and acceleration of solar ultraviolet damage

    NASA Technical Reports Server (NTRS)

    Laue, E.; Gupta, A.

    1979-01-01

    An environmental test chamber providing acceleration of UV radiation and precise temperature control (+ or -)1 C was designed, constructed and tested. This chamber allows acceleration of solar ultraviolet up to 30 suns while maintaining temperature of the absorbing surface at 30 C - 60 C. This test chamber utilizes a filtered medium pressure mercury arc as the source of radiation, and a combination of selenium radiometer and silicon radiometer to monitor solar ultraviolet (295-340 nm) and total radiant power output, respectively. Details of design and construction and operational procedures are presented along with typical test data.

  19. Field performance of self-siphon sediment cleansing set for sediment removal in deep CSO chamber.

    PubMed

    Zhou, Yongchao; Zhang, Yiping; Tang, Ping

    2013-01-01

    This paper presents a study of the self-siphon sediment cleansing set (SSCS), a system designed to remove sediment from the deep combined sewer overflow (CSO) chamber during dry-weather periods. In order to get a better understanding of the sediment removal effectiveness and operational conditions of the SSCS system, we carried out a full-scale field study and comparison analysis on the sediment depth changes in the deep CSO chambers under the conditions with and without the SSCS. The field investigation results demonstrated that the SSCS drains the dry-weather flow that accumulated for 50-57 min from the sewer channel to the intercepting system in about 10 min. It is estimated that the bed shear stress in the CSO chamber and sewer channel is improved almost 25 times on average. The SSCS acts to remove the near bed solids with high pollution load efficiently. Moreover, it cleans up not only the new sediment layer but also part of the previously accumulated sediment.

  20. Ultra-high vacuum photoelectron linear accelerator

    DOEpatents

    Yu, David U.L.; Luo, Yan

    2013-07-16

    An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.

  1. Accelerated weathering of limestone for CO2 mitigation opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, W.H.; Juan, C.A.S.; Rau, G.H.; Caldeira, K.

    2009-01-01

    Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO 2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO 2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

  2. THOR contribution to space weather science

    NASA Astrophysics Data System (ADS)

    Vaivads, A.; Opgenoorth, H. J.; Retino, A.; Khotyaintsev, Y. V.; Soucek, J.; Valentini, F.; Escoubet, C. P.; Chen, C. H. K.; Vainio, R. O.; Fazakerley, A. N.; Lavraud, B.; Narita, Y.; Marcucci, M. F.; Kucharek, H.; Bale, S. D.; Moore, T. E.; Kistler, L. M.; Samara, M.

    2016-12-01

    Turbulence Heating ObserveR - THOR is a mission proposal to study energy dissipation and particle acceleration in turbulent space plasma. THOR will focus on turbulent plasma in pristine solar wind, bow shock and magnetosheath. The orbit of THOR is tuned to spend long times in those regions allowing THOR to obtain high resolution data sets that can be used also for space weather science. Here we will discuss the space weather science questions that can be addressed and significantly advanced using THOR. Link to THOR: http://thor.irfu.se.

  3. Apparatus and method for the acceleration of projectiles to hypervelocities

    DOEpatents

    Hertzberg, Abraham; Bruckner, Adam P.; Bogdanoff, David W.

    1990-01-01

    A projectile is initially accelerated to a supersonic velocity and then injected into a launch tube filled with a gaseous propellant. The projectile outer surface and launch tube inner surface form a ramjet having a diffuser, a combustion chamber and a nozzle. A catalytic coated flame holder projecting from the projectile ignites the gaseous propellant in the combustion chamber thereby accelerating the projectile in a subsonic combustion mode zone. The projectile then enters an overdriven detonation wave launch tube zone wherein further projectile acceleration is achieved by a formed, controlled overdriven detonation wave capable of igniting the gaseous propellant in the combustion chamber. Ultrahigh velocity projectile accelerations are achieved in a launch tube layered detonation zone having an inner sleeve filled with hydrogen gas. An explosive, which is disposed in the annular zone between the inner sleeve and the launch tube, explodes responsive to an impinging shock wave emanating from the diffuser of the accelerating projectile thereby forcing the inner sleeve inward and imparting an acceleration to the projectile. For applications wherein solid or liquid high explosives are employed, the explosion thereof forces the inner sleeve inward, forming a throat behind the projectile. This throat chokes flow behind, thereby imparting an acceleration to the projectile.

  4. Reducing energy-related CO2 emissions using accelerated weathering of limestone

    USGS Publications Warehouse

    Rau, Greg H.; Knauss, Kevin G.; Langer, William H.; Caldeira, Ken

    2007-01-01

    The use and impacts of accelerated weathering of limestone (AWL; reaction: CO2+H2O+CaCO3→Ca2++2(HCO3-) is explored as a CO2 capture and sequestration method. It is shown that significant limestone resources are relatively close to a majority of CO2-emitting power plants along the coastal US, a favored siting location for AWL. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could provide an inexpensive or free source of AWL carbonate. With limestone transportation then as the dominant cost variable, CO2 mitigation costs of $3-$4/tonne appear to be possible in certain locations. Perhaps 10–20% of US point–source CO2 emissions could be mitigated in this fashion. It is experimentally shown that CO2 sequestration rates of 10-6 to 10-5 moles/sec per m2 of limestone surface area are achievable, with reaction densities on the order of 10-2 tonnes CO2 m-3day-1, highly dependent on limestone particle size, solution turbulence and flow, and CO2 concentration. Modeling shows that AWL would allow carbon storage in the ocean with significantly reduced impacts to seawater pH relative to direct CO2 disposal into the atmosphere or sea. The addition of AWL-derived alkalinity to the ocean may itself be beneficial for marine biota.

  5. Acceleration performance of individual European sea bass Dicentrarchus labrax measured with a sprint performance chamber: comparison with high-speed cinematography and correlates with ecological performance.

    PubMed

    Vandamm, Joshua P; Marras, Stefano; Claireaux, Guy; Handelsman, Corey A; Nelson, Jay A

    2012-01-01

    Locomotor performance can influence the ecological and evolutionary success of a species. For fish, favorable outcomes of predator-prey encounters are often presumably due to robust acceleration ability. Although escape-response or "fast-start" studies utilizing high-speed cinematography are prevalent, little is known about the contribution of relative acceleration performance to ecological or evolutionary success in a species. This dearth of knowledge may be due to the time-consuming nature of analyzing film, which imposes a practical limit on sample sizes. Herein, we present a high-throughput potential alternative for measuring fish acceleration performance using a sprint performance chamber (SPC). The acceleration performance of a large number of juvenile European sea bass (Dicentrarchus labrax) from two populations was analyzed. Animals from both hatchery and natural ontogenies were assessed, and animals of known acceleration ability had their ecological performance measured in a mesocosm environment. Individuals from one population also had their acceleration performance assessed by both high-speed cinematography and an SPC. Acceleration performance measured in an SPC was lower than that measured by classical high-speed video techniques. However, short-term repeatability and interindividual variation of acceleration performance were similar between the two techniques, and the SPC recorded higher sprint swimming velocities. Wild fish were quicker to accelerate in an SPC and had significantly greater accelerations than all groups of hatchery-raised fish. Acceleration performance had no significant effect on ecological performance (as assessed through animal growth and survival in the mesocosms). However, it is worth noting that wild animals did survive predation in the mesocosm better than farmed ones. Moreover, the hatchery-originated fish that survived the mesocosm experiment, when no predators were present, displayed significantly increased acceleration

  6. Observational Simulation of Icing in Extreme Weather Conditions

    NASA Astrophysics Data System (ADS)

    Gultepe, Ismail; Heymsfield, Andrew; Agelin-Chaab, Martin; Komar, John; Elfstrom, Garry; Baumgardner, Darrel

    2017-04-01

    Observations and prediction of icing in extreme weather conditions are important for aviation, transportation, and shipping applications, and icing adversely affects the economy. Icing environments can be studied either in the outdoor atmosphere or in the laboratory. There have been several aircraft based in-situ studies related to weather conditions affecting aviation operations, transportation, and marine shipping that includes icing, wind, and turbulence. However, studying severe weather conditions from aircraft observations are limited due to safety and sampling issues, instrumental uncertainties, and even the possibility of aircraft producing its own physical and dynamical effects. Remote sensing based techniques (e.g. retrieval techniques) for studying severe weather conditions represent usually a volume that cannot characterize the important scales and also represents indirect observations. Therefore, laboratory simulations of atmospheric processes can help us better understand the interactions among microphysical and dynamical processes. The Climatic Wind Tunnel (CWT) in ACE at the University of Ontario Institute of Technology (UOIT) has a large semi-open jet test chamber with flow area 7-13 m2 that can precisely control temperatures down to -40°C, and up to 250 km hr-1 wind speeds, for heavy or dry snow conditions with low visibility, similar to ones observed in the Arctic and cold climate regions, or at high altitude aeronautical conditions. In this study, the ACE CWT employed a spray nozzle array suspended in its settling chamber and fed by pressurized water, creating various particle sizes from a few microns up to mm size range. This array, together with cold temperature and high wind speed, enabled simulation of severe weather conditions, including icing, visibility, strong wind and turbulence, ice fog and frost, freezing fog, heavy snow and blizzard conditions. In this study, the test results will be summarized, and their application to aircraft

  7. Bakeout Chamber Within Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Taylor, Daniel M.; Soules, David M.; Barengoltz, Jack B.

    1995-01-01

    Vacuum-bakeout apparatus for decontaminating and measuring outgassing from pieces of equipment constructed by mounting bakeout chamber within conventional vacuum chamber. Upgrade cost effective: fabrication and installation of bakeout chamber simple, installation performed quickly and without major changes in older vacuum chamber, and provides quantitative data on outgassing from pieces of equipment placed in bakeout chamber.

  8. Surface characterization of weathered wood-plastic composites produced from modified wood flour

    Treesearch

    James S. Fabiyi; Armando G. McDonald; Nicole M. Stark

    2007-01-01

    The effects of weathering on the surface properties of wood-plastic composites (WPC) were examined. High-density polyethylene (HDPE) based WPCs made from modified wood flour (untreated, extractives free, and holocellulose (delignified) fibers) were subjected to accelerated (xenon-arc) weathering. Colorimetry and Fourier-transform infrared spectroscopy were employed to...

  9. Strategy for future space weather observational assets

    NASA Astrophysics Data System (ADS)

    Davies, Jackie; Bogdanova, Yulia; Harrison, Richard; Bisi, Mario; Hapgood, Mike

    2017-04-01

    Observations from an ad-hoc suite of mainly aging, scientific, space-borne assets currently underpin space weather forecasting capabilities world-wide. While efforts have begun to replace / supplement these assets - in particular with the recent launch of the DSCOVR spacecraft - it is widely accepted that there is an urgent need to accelerate these endeavours in order to mitigate the risk of losing these critical observations. It is hence opportune to critically review the possible options for the provision of space weather observations, particularly in terms of identifying the optimum vantage point(s) and the instrumentation that will provide the most beneficial measurements to support space weather prediction. Here we present the results of several recent European studies that aim to identify the best solution for space-based space weather monitoring - obviously within realistic financial constraints and bearing in mind the immediacy with which such a mission needs to be realised.

  10. Enhanced weathering strategies for cooling the planet and saving coral reefs

    NASA Astrophysics Data System (ADS)

    Beerling, D. J.; Taylor, L.; Quirk, J.; Thorley, R.; Kharecha, P. A.; Hansen, J. E.; Ridgwell, A. J.; Lomas, M.; Banwart, S. A.

    2014-12-01

    Acceleration of the chemical weathering sink for atmospheric CO2 via distribution of pulverized silicate rocks across terrestrial landscapes has been proposed as a macro-engineering Carbon Dioxide Removal (CDR) scheme, but its effectiveness and response to ongoing global change is poorly understood. We employ a detailed spatially resolved weathering model driven by two ensemble Representative Concentration Pathway (RCP) projections of 21st Century climate (RCP8.5 and RCP4.5) to assess enhanced weathering and examine feedbacks on atmospheric CO2 and ocean carbonate biogeochemistry. Atmospheric CO2 reduction of ~100-260 ppm by year 2100, the range depending mainly on rock composition, is obtained by spreading 5 kg m-2 yr-1 over 20 Mkm2 tropical weathering 'hotspots'. Ocean acidification is neutralized in RCP4.5 and ameliorated in RCP8.5 due to enhanced land-ocean export of weathered alkalinity products and reduced CO2 forcings, and the aragonite saturation state of surface oceans is raised to >3.5, thus avoiding likely extinction of coral reef ecosystems. We suggest that accelerated weathering has substantial potential to help limit global warming and benefits to marine life not obtained from other CDR approaches, but major issues of cost, social acceptability, and potential unanticipated consequences should encourage urgent efforts to phase down fossil fuel emissions.

  11. LIONs at the Stanford Linear Accelerator Center

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

    Constant, T.N.; Zdarko, R.W.; Simmons, R.H.

    1998-01-01

    The term LION is an acronym for Long Ionization Chamber. This is a distributed ion chamber which is used to monitor secondary ionization along the shield walls of a beam line resulting from incorrectly steered charged particle beams in lieu of the use of many discrete ion chambers. A cone of ionizing radiation emanating from a point source as a result of incorrect steering intercepts a portion of 1-5/8 inch Heliax cable (about 100 meters in length) filled with Argon gas at 20 psi and induces a pulsed current which is proportional to the ionizing charge. This signal is transmittedmore » via the cable to an integrator circuit whose output is directed to an electronic comparators, which in turn is used to turn off the accelerated primary beam when preset limits are exceeded. This device is used in the Stanford Linear Accelerator Center (SLAC) Beam Containment System (BCS) to prevent potentially hazardous ionizing radiation resulting from incorrectly steered beams in areas that might be occupied by people. This paper describes the design parameters and experience in use in the Final Focus Test Beam (FFTB) area of the Stanford Linear Accelerator Center.« less

  12. BLISTERING AND DEGRADATION OF POLYURETHANE COATINGS UNDER DIFFERENT ACCELERATED WEATHERING TESTS. (R828081E01)

    EPA Science Inventory

    An epoxy primer with a high gloss polyurethane topcoat coating system was exposed either only in a QUV chamber or exposed in a QUV chamber and a Prohesion chamber, alternatively, in this study. AFM studies found that micro blisters formed on the coating surface after both expo...

  13. Quasi-Steady Acceleration Direction Indicator in Three Dimensions

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Nelson, Emily S.; Jules, Kenol

    2000-01-01

    Many materials processing and fluids physics experiments conducted in a microgravity environment require knowledge of the orientation of the low-frequency acceleration vector. This need becomes especially acute for space experiments such as directional solidification of a molten semiconductor, which is extremely sensitive to orientation and may involve tens of hours of operations of a materials furnace. These low-frequency acceleration data have been measured for many Shuttle missions with the Orbital Acceleration Research Experiment. Previous attempts at using fluid chambers for acceleration measurements have met with limited success due to pointing and vehicle attitude complications. An acceleration direction indicator is described, which is comprised of two orthogonal short cylinders of fluid, each with a small bubble. The motion and the position of the bubble within the chamber will indicate the direction of the acceleration experienced at the sensor location. The direction of the acceleration vector may then be calculated from these data. The frequency response of such an instrument may be tailored for particular experiments with the proper selection of fluid and gas parameters, surface type, and geometry. A three-dimensional system for sensing and displaying the low-frequency acceleration direction via an innovative technique described in this paper has advantages in terms of size, mass, and power compared with electronic instrumentation systems.

  14. Research on structural design and test technologies for a three-chamber launching device

    NASA Astrophysics Data System (ADS)

    Jun, Wu; Qiushi, Yan; Ling, Xiao; Tieshuan, Zhuang; Chengyu, Yang

    2016-07-01

    A three-chamber launching device with improved acceleration is proposed and developed. As indicated by the damage generated during the pill and engineering protection tests, the proposed device is applicable as a high-speed launching platform for pills of different shapes and quality levels. Specifically, it can be used to investigate kinetic energy weapons and their highly destructive effects due to the resulting large bomb fragments. In the horizontal direction of the barrel, two auxiliary chambers are set at a certain distance from the main chamber. When the pill reaches the mouth of the auxiliary chambers, the charges in the auxiliary chambers are ignited by the high-temperature, high-pressure combustible gas trailing the pill. The combustible gas in the auxiliary chambers can resist the rear pressure of the pill and thus maintain the high pressure of the pill base. In this way, the required secondary acceleration of the pill is met. The proposed device features the advantage of launching a pill with high initial velocity under low bore pressure. Key techniques are proposed in the design of the device to address the problems related to the angle between the main chamber axis and the ancillary chamber axis, the overall design of a three-chamber barrel, the structural design of auxiliary propellant charge, the high-pressure combustible gas sealing technology, and the sabot and belt design. Results from the launching test verify the reasonable design of this device and its reliable structural sealing. Additionally, the stiffness and the strength of the barrel meet design requirements. Compared with the single-chamber launching device with the same caliber, the proposed device increases the average launching velocity by approximately 15% and the amount of muzzle kinetic energy by approximately 35%. Therefore, this equipment is capable of carrying out small-caliber, high-speed pill firing tests.

  15. Pulsed electromagnetic gas acceleration

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

    1971-01-01

    Experimental data were combined with one-dimensional conservation relations to yield information on the energy deposition ratio in a parallel-plate accelerator, where the downstream flow was confined to a constant area channel. Approximately 70% of the total input power was detected in the exhaust flow, of which only about 20% appeared as directed kinetic energy, thus implying that a downstream expansion to convert chamber enthalpy into kinetic energy must be an important aspect of conventional high power MPD arcs. Spectroscopic experiments on a quasi-steady MPD argon accelerator verified the presence of A(III) and the absence of A(I), and indicated an azimuthal structure in the jet related to the mass injection locations. Measurements of pressure in the arc chamber and impact pressure in the exhaust jet using a piezocrystal backed by a Plexiglas rod were in good agreement with the electromagnetic thrust model.

  16. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam M.

    2011-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications, including the treatment of medical conditions. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy available in the developing world for the treatment of a variety of medical conditions. Specifically, hyperbaric oxygen therapy is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. Hyperbaric oxygen therapy is simply too expensive and too dangerous to implement in the developing world using standard equipment. The hydrostatic hyperbaric chamber technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system that will provide controlled pressurization of the system, and provide adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the

  17. Development of Alumina Ceramics Vacuum Chamber for J-PARC

    NASA Astrophysics Data System (ADS)

    Kinsho, Michikazu; Saito, Yoshio; Kabeya, Zenzaburo; Ogiwara, Norio

    We successfully developed alumina ceramics vacuum chamber for the 3 GeV-RCS of J-PARC at JAEA. This chamber has titanium flanges and an outer RF shield to reduce duct impedance, and moreover TiN film is coated on the inside surface to preclude charge build up and to reduce secondary emitted electrons. The outgassing rate of the ceramics chamber measured by the conductance modulation method has a sufficiently low value of 1.2×10-8 Pa m3 s-1 m2 after 50 hours pumping. The temperature of the titanium flange became 45°C due to eddy current heating under dipole magnet operation. It was found that the radiation damage to the capacitor used for the RF shield of this duct was small, the capacitance only decreased by 7% after gamma ray irradiation of 30 MGy. In order to determine effect of the ceramics chamber on the proton beam, this ceramics chamber prepared for J-PARC was installed instead in the 12 GeV main ring at KEK-PS. The proton beam could be controlled to accelerate stably after installation, and thus it was found that this chamber did not influence the beam very much. This ceramics chamber is thus usable for the 3 GeV-RCS of J-PARC.

  18. Microwave Radiometer Technology Acceleration Mission (MiRaTA): Advancing Weather Remote Sensing with Nanosatellites

    NASA Astrophysics Data System (ADS)

    Cahoy, K.; Blackwell, W. J.; Bishop, R. L.; Erickson, N.; Fish, C. S.; Neilsen, T. L.; Stromberg, E. M.; Bardeen, J.; Dave, P.; Marinan, A.; Marlow, W.; Kingsbury, R.; Kennedy, A.; Byrne, J. M.; Peters, E.; Allen, G.; Burianek, D.; Busse, F.; Elliott, D.; Galbraith, C.; Leslie, V. V.; Osaretin, I.; Shields, M.; Thompson, E.; Toher, D.; DiLiberto, M.

    2014-12-01

    The Microwave Radiometer Technology Acceleration (MiRaTA) is a 3U CubeSat mission sponsored by the NASA Earth Science Technology Office (ESTO). Microwave radiometer measurements and GPS radio occultation (GPSRO) measurements of all-weather temperature and humidity provide key contributions toward improved weather forecasting. The MiRaTA mission will validate new technologies in both passive microwave radiometry and GPS radio occultation: (1) new ultra-compact and low-power technology for multi-channel and multi-band passive microwave radiometers, and (2) new GPS receiver and patch antenna array technology for GPS radio occultation retrieval of both temperature-pressure profiles in the atmosphere and electron density profiles in the ionosphere. In addition, MiRaTA will test (3) a new approach to spaceborne microwave radiometer calibration using adjacent GPSRO measurements. The radiometer measurement quality can be substantially improved relative to present systems through the use of proximal GPSRO measurements as a calibration standard for radiometric observations, reducing and perhaps eliminating the need for costly and complex internal calibration targets. MiRaTA will execute occasional pitch-up maneuvers so that the radiometer and GPSRO observations sound overlapping volumes of atmosphere through the Earth's limb. To validate system performance, observations from both microwave radiometer (MWR) and GPSRO instruments will be compared to radiosondes, global high-resolution analysis fields, other satellite observations, and to each other using radiative transfer models. Both the radiometer and GPSRO payloads, currently at TRL5 but to be advanced to TRL7 at mission conclusion, can be accommodated in a single 3U CubeSat. The current plan is to launch from an International Space Station (ISS) orbit at ~400 km altitude and 52° inclination for low-cost validation over a ~90-day mission to fly in 2016. MiRaTA will demonstrate high fidelity, well-calibrated radiometric

  19. Small field out-put factors comparison between ion chambers and diode dedectors for different photon energies

    NASA Astrophysics Data System (ADS)

    Tas, B.; Durmus, I. F.

    2018-02-01

    To compare small fields out-put factors of linear accelerator by using different ion chambers and diode dedectors for different photon energies. We measured small fields (1×1 to 5×5 cm2) out-put factors by using IBA® cc003 nano chamber, cc01 Razor, cc01, cc04, cc13, fc65 ion chambers and SFD, Razor diode dedectors for 6MV, 10MV, 15MV, 6MV FFF and 10MV FFF energies. We determined the most compatible out-put factors between ion chamber and diode dedector by using cc003 nano ion chamber for 1×1cm2 field size. We determined less than %2 dose difference between cc003 nano chamber, cc01 Razor, cc01, cc04 and cc13 ion chambers from 2×2 to 5×5 cm2. We determined %12±2 and %13±1 underestimate doses by using cc01 and cc13 ion chambers, also we determined %57±2 underesimate dose by using fc65 ion chamber's than razor diode for 1×1 cm2 field size. These results show that we shouldn't measure out-put factors of 1×1 cm2 field size by using cc01, cc13 and fc65 ion chambers. The dose difference between SFD and Razor diodes were determined less than %1.5. If we would like to use ion chambers for ≤1×1cm2 field size out-put measurement, we should use correction factor while commisionning linear accelerator. Otherwise we could determine underestimate dose by using ion chambers.

  20. Position-sensitive, fast ionization chambers

    NASA Astrophysics Data System (ADS)

    Lai, J.; Afanasieva, L.; Blackmon, J. C.; Deibel, C. M.; Gardiner, H. E.; Lauer, A.; Linhardt, L. E.; Macon, K. T.; Rasco, B. C.; Williams, C.; Santiago-Gonzalez, D.; Kuvin, S. A.; Almaraz-Calderon, S.; Baby, L. T.; Baker, J.; Belarge, J.; Wiedenhöver, I.; Need, E.; Avila, M. L.; Back, B. B.; DiGiovine, B.; Hoffman, C. R.

    2018-05-01

    A high-count-rate ionization chamber design with position-sensitivity has been developed and deployed at several accelerator facilities. Counting rates of ≥ 500 kHz with good Z-separation (up to 5% energy resolution) for particle identification have been demonstrated in a series of commissioning experiments. A position-sensitive capability, with a resolution of 3 mm, has been implemented for the first time to record position information and suppress pileup. The design and performance of the detectors are described.

  1. Effect of weathering variables on the lightness of high-density polyethylene woodflour composites

    Treesearch

    Nicole M. Stark

    2005-01-01

    Wood-plastic lumber is promoted as a low-maintenance, high-durability product. After weathering, however, wood-plastic composites (WPCs) often fade. In the first part of this study, 50 percent woodflour-filled high- density polyethylene (HDPE) composite samples were manufactured. Composites were exposed to two accelerated weathering cycles in a xenon- arc type...

  2. CFD Code Survey for Thrust Chamber Application

    NASA Technical Reports Server (NTRS)

    Gross, Klaus W.

    1990-01-01

    In the quest fo find analytical reference codes, responses from a questionnaire are presented which portray the current computational fluid dynamics (CFD) program status and capability at various organizations, characterizing liquid rocket thrust chamber flow fields. Sample cases are identified to examine the ability, operational condition, and accuracy of the codes. To select the best suited programs for accelerated improvements, evaluation criteria are being proposed.

  3. Dose verification with different ion chambers for SRT/SBRT plans

    NASA Astrophysics Data System (ADS)

    Durmus, I. F.; Tas, B.; Okumus, A.; Uzel, O. E.

    2017-02-01

    Verification of patient plan is very important in stereotactic treatments. VMAT plans were prepared with 6MV-FFF or 10MV-FFF energies for 25 intracranial and extracranial stereotactic patients. Absolute dose was measured for dose verification in each plans. Iba® CC01, Iba® CC04, Iba® CC13 ion chambers placed at a depth of 5cm in solid phantom (RW3). Also we scanned this phantom with ion chambers by Siemens® Biograph mCT. QA plans were prepared by transferring twenty five patient plans to phantom assemblies for three ion chambers. All plans were performed separately for three ion chambers at Elekta® Versa HD linear accelerator. Statistical analysis of results were made by Wilcoxon signed-rank test. Difference between dose values were determined %1.84±3.4 (p: 0.001) with Iba CC13 ion chamber, %1.80±3.4 (p: 0.002) with Iba CC04 ion chamber and %0.29±4.6 (p: 0.667) with Iba CC01 ion chamber. In stereotactic treatments, dosimetric uncertainty increases in small areas. We determined more accurate results with small sized detectors. Difference between TPS calculations and all measurements were founded lower than %2.

  4. Track chambers based on precision drift tubes housed inside 30 mm mylar pipe

    NASA Astrophysics Data System (ADS)

    Borisov, A.; Bozhko, N.; Fakhrutdinov, R.; Kozhin, A.; Leontiev, B.; Levin, A.

    2014-06-01

    We describe drift chambers consisting of 3 layers of 30 mm (OD) drift tubes made of double sided aluminized mylar film with thickness 0.125 mm. A single drift tube is self-supported structure withstanding 350 g tension of 50 microns sense wire located in the tube center with 10 microns precision with respect to end-plug outer surface. Such tubes allow to create drift chambers with small amount of material, construction of such chambers doesn't require hard frames. Twenty six chambers with working area from 0.8 × 1.0 to 2.5 × 2.0 m2 including 4440 tubes have been manufactured for experiments at 70-GeV proton accelerator at IHEP(Protvino).

  5. Space Weather: Where Is The Beef?

    NASA Astrophysics Data System (ADS)

    Koskinen, H. E. J.

    Space weather has become a highly fashionable topic in solar-terrestrial physics. It is perhaps the best tool to popularise the field and it has contributed significantly to the dialogue between solar, magnetospheric, and ionospheric scientist, and also to mu- tual understanding between science and engineering communities. While these are laudable achievements, it is important for the integrity of scientific space weather re- search to recognise the central open questions in the physics of space weather and the progress toward solving them. We still lack sufficient understanding of the solar physics to be able to tell in advance when and where a solar eruption will take place and whether it will turn to a geoeffective event. There is much to do to understand ac- celeration of solar energetic particles and propagation of solar mass ejecta toward the Earth. After more than 40 years of research scientific discussion of energy and plasma transfer through the magnetopause still deals mostly with qualitative issues and the rapid acceleration processes in the magnetosphere are not yet explained in a satisfac- tory way. Also the coupling to the ionosphere and from there to the strong induction effects on ground is another complex of research problems. For space weather science the beef is in the investigation of these and related topics, not in marketing half-useful space weather products to hesitant customers.

  6. Weather Safety - NOAA's National Weather Service

    Science.gov Websites

    Statistical Models... MOS Prod GFS-LAMP Prod Climate Past Weather Predictions Weather Safety Weather Radio National Weather Service on FaceBook NWS on Facebook NWS Director Home > Safety Weather Safety This page weather safety. StormReady NOAA Weather Radio Emergency Managers Information Network U.S. Hazard Assmt

  7. Modeling the influence of organic acids on soil weathering

    NASA Astrophysics Data System (ADS)

    Lawrence, Corey; Harden, Jennifer; Maher, Kate

    2014-08-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  8. Modeling the influence of organic acids on soil weathering

    USGS Publications Warehouse

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  9. Effect of processing method on surface and weathering characteristics of wood-flour/HDPE composites

    Treesearch

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2004-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  10. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware

  11. Design and Installation of a Field Ionization Test Chamber for Ion Thrusters

    DTIC Science & Technology

    2011-12-01

    where F is thrust, m& is the mass flow rate of the propellant, and go is the standard acceleration due to gravity at sea level [1]. It provides a...only one graphene wall, and multi- walled CNT ( MWCNT ), which consist of multiple, concentric walls of graphene (Figure 9). One of the most unique...ionization chamber to ensure the mass flow rate going into the chamber matches the mass flow rate leaving it. 46 B. FIELD EMISSION AND FIELD

  12. Weatherization and Intergovernmental Programs Office FY 2017 Budget At-A-Glance

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

    None

    2016-03-01

    The Weatherization and Intergovernmental Programs (WIP) Office is part of EERE’s balanced research, development, demonstration, and deployment approach to accelerate America’s transition to a clean energy economy. WIP’s mission is to partner with state and local organizations to improve energy security and to significantly accelerate the deployment of clean energy technologies and practices by a wide range of government, community, and business stakeholders.

  13. Predictive models of poly(ethylene-terephthalate) film degradation under multi-factor accelerated weathering exposures

    PubMed Central

    Ngendahimana, David K.; Fagerholm, Cara L.; Sun, Jiayang; Bruckman, Laura S.

    2017-01-01

    Accelerated weathering exposures were performed on poly(ethylene-terephthalate) (PET) films. Longitudinal multi-level predictive models as a function of PET grades and exposure types were developed for the change in yellowness index (YI) and haze (%). Exposures with similar change in YI were modeled using a linear fixed-effects modeling approach. Due to the complex nature of haze formation, measurement uncertainty, and the differences in the samples’ responses, the change in haze (%) depended on individual samples’ responses and a linear mixed-effects modeling approach was used. When compared to fixed-effects models, the addition of random effects in the haze formation models significantly increased the variance explained. For both modeling approaches, diagnostic plots confirmed independence and homogeneity with normally distributed residual errors. Predictive R2 values for true prediction error and predictive power of the models demonstrated that the models were not subject to over-fitting. These models enable prediction under pre-defined exposure conditions for a given exposure time (or photo-dosage in case of UV light exposure). PET degradation under cyclic exposures combining UV light and condensing humidity is caused by photolytic and hydrolytic mechanisms causing yellowing and haze formation. Quantitative knowledge of these degradation pathways enable cross-correlation of these lab-based exposures with real-world conditions for service life prediction. PMID:28498875

  14. Flow chamber

    DOEpatents

    Morozov, Victor [Manassas, VA

    2011-01-18

    A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

  15. Solar Radio Bursts and Space Weather

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Natchimuthuk,

    2012-01-01

    Radio bursts from the Sun are produced by electron accelerated to relativistic energies by physical processes on the Sun such as solar flares and coronal mass ejections (CMEs). The radio bursts are thus good indicators of solar eruptions. Three types of nonthermal radio bursts are generally associated with CMEs. Type III bursts due to accelerated electrons propagating along open magnetic field lines. The electrons are thought to be accelerated at the reconnection region beneath the erupting CME, although there is another view that the electrons may be accelerated at the CME-driven shock. Type II bursts are due to electrons accelerated at the shock front. Type II bursts are also excellent indicators of solar energetic particle (SEP) events because the same shock is supposed accelerate electrons and ions. There is a hierarchical relationship between the wavelength range of type /I bursts and the CME kinetic energy. Finally, Type IV bursts are due to electrons trapped in moving or stationary structures. The low frequency stationary type IV bursts are observed occasionally in association with very fast CMEs. These bursts originate from flare loops behind the erupting CME and hence indicate tall loops. This paper presents a summary of radio bursts and their relation to CMEs and how they can be useful for space weather predictions.

  16. Effect of weathering cycle and manufacturing method on performance of wood flour and high-density polyethylene composites

    Treesearch

    Nicole M. Stark

    2006-01-01

    Wood–plastic lumber is promoted as a low-maintenance high-durability product. When exposed to accelerated weathering, however, wood–plastic composites may experience a color change and loss in mechanical properties. Differences in weathering cycle and composite surface characteristics can affect the rate and amount of change caused by weathering. In this study, 50%...

  17. Dosimetry for electron Intra-Operative RadioTherapy: Comparison of output factors obtained through alanine/EPR pellets, ionization chamber and Monte Carlo-GEANT4 simulations for IORT mobile dedicate accelerator

    NASA Astrophysics Data System (ADS)

    Marrale, Maurizio; Longo, Anna; Russo, Giorgio; Casarino, Carlo; Candiano, Giuliana; Gallo, Salvatore; Carlino, Antonio; Brai, Maria

    2015-09-01

    In this work a comparison between the response of alanine and Markus ionization chamber was carried out for measurements of the output factors (OF) of electron beams produced by a linear accelerator used for Intra-Operative Radiation Therapy (IORT). Output factors (OF) for conventional high-energy electron beams are normally measured using ionization chamber according to international dosimetry protocols. However, the electron beams used in IORT have characteristics of dose per pulse, energy spectrum and angular distribution quite different from beams usually used in external radiotherapy, so the direct application of international dosimetry protocols may introduce additional uncertainties in dosimetric determinations. The high dose per pulse could lead to an inaccuracy in dose measurements with ionization chamber, due to overestimation of ks recombination factor. Furthermore, the electron fields obtained with IORT-dedicated applicators have a wider energy spectrum and a wider angular distribution than the conventional fields, due to the presence of electrons scattered by the applicator's wall. For this reason, a dosimetry system should be characterized by a minimum dependence from the beam energy and from angle of incidence of electrons. This become particularly critical for small and bevelled applicators. All of these reasons lead to investigate the use of detectors different from the ionization chamber for measuring the OFs. Furthermore, the complete characterization of the radiation field could be accomplished also by the use of Monte Carlo simulations which allows to obtain detailed information on dose distributions. In this work we compare the output factors obtained by means of alanine dosimeters and Markus ionization chamber. The comparison is completed by the Monte Carlo calculations of OFs determined through the use of the Geant4 application "iort _ therapy" . The results are characterized by a good agreement of response of alanine pellets and Markus

  18. Modeling rock weathering in small watersheds

    NASA Astrophysics Data System (ADS)

    Pacheco, Fernando A. L.; Van der Weijden, Cornelis H.

    2014-05-01

    Many mountainous watersheds are conceived as aquifer media where multiple groundwater flow systems have developed (Tóth, 1963), and as bimodal landscapes where differential weathering of bare and soil-mantled rock has occurred (Wahrhaftig, 1965). The results of a weathering algorithm (Pacheco and Van der Weijden, 2012a, 2014), which integrates topographic, hydrologic, rock structure and chemical data to calculate weathering rates at the watershed scale, validated the conceptual models in the River Sordo basin, a small watershed located in the Marão cordillera (North of Portugal). The coupling of weathering, groundwater flow and landscape evolution analyses, as accomplished in this study, is innovative and represents a remarkable achievement towards regionalization of rock weathering at the watershed scale. The River Sordo basin occupies an area of approximately 51.2 km2 and was shaped on granite and metassediment terrains between the altitudes 185-1300 m. The groundwater flow system is composed of recharge areas located at elevations >700 m, identified on the basis of δ18O data. Discharge cells comprehend terminations of local, intermediate and regional flow systems, identified on the basis of spring density patterns, infiltration depth estimates based on 87Sr/86Sr data, and spatial distributions of groundwater pH and natural mineralization. Intermediate and regional flow systems, defined where infiltration depths >125 m, develop solely along the contact zone between granites and metassediments, because fractures in this region are profound and their density is very large. Weathering is accelerated where rocks are covered by thick soils, being five times faster relative to sectors of the basin where rocks are covered by thin soils. Differential weathering of bare and soil-mantled rock is also revealed by the spatial distribution of calculated aquifer hydraulic diffusivities and groundwater travel times.

  19. Calibration of cathode strip gains in multiwire drift chambers of the GlueX experiment

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

    Berdnikov, V. V.; Somov, S. V.; Pentchev, L.

    A technique for calibrating cathode strip gains in multiwire drift chambers of the GlueX experiment is described. The accuracy of the technique is estimated based on Monte Carlo generated data with known gain coefficients in the strip signal channels. One of the four detector sections has been calibrated using cosmic rays. Results of drift chamber calibration on the accelerator beam upon inclusion in the GlueX experimental setup are presented.

  20. Reducing Energy-Related CO2 Emissions Using Accelerated Limestone Weathering

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

    Rau, G H; Knauss, K G; Langer, W H

    2004-04-27

    Following earlier descriptions, the use and impacts of accelerated weathering of limestone AWL; reaction: CO{sub 2} + H{sub 2}O + CaCO{sub 3} {yields} Ca{sup 2+} + 2(HCO{sub 3}{sup -}) as a CO{sub 2} capture and sequestration method is further explored. Since ready access to the ocean is likely an essential requirement for AWL, it is shown that significant limestone resources are relatively close to a majority of CO{sub 2}-emitting power plants along the coastal US. Furthermore, waste fines, representing more than 20% of current US crushed limestone production (>10{sup 9} tonnes/yr), could be used in many instances as an inexpensivemore » or free source of AWL carbonate. With limestone transportation to coastal sites then as the dominant cost variable, CO{sub 2} sequestration (plus capture) costs of $3-$4/tonne are achievable in certain locations. While there is vastly more limestone and water on earth than that required for AWL to capture and sequester all fossil fuel CO{sub 2} production, the transportation cost of bringing limestone, seawater, and waste CO{sub 2} into contact likely limits the method's applicability to perhaps 10-20% of US point-source emissions. Using a bench-scale laboratory reactor, it is shown that CO{sub 2} sequestration rates of 10{sup -6} to 10{sup -5} moles/sec per m{sup 2} of limestone surface area are readily achievable using seawater. This translates into reaction densities as high as 2 x 10{sup -2} tonnes CO{sub 2} m{sup -3}day{sup -1}, highly dependent on limestone particle size, solution turbulence and flow, and CO{sub 2} concentration. Modeling of AWL end-solution disposal in the ocean shows significantly reduced effects on ocean pH and carbonate chemistry relative to those caused by direct CO{sub 2} disposal into the atmosphere or ocean. In fact the increase in ocean Ca{sup 2+} and bicarbonate offered by AWL should significantly enhance the growth of corals and other marine calcifiers whose health is currently being threatened

  1. Intel Xeon Phi accelerated Weather Research and Forecasting (WRF) Goddard microphysics scheme

    NASA Astrophysics Data System (ADS)

    Mielikainen, J.; Huang, B.; Huang, A. H.-L.

    2014-12-01

    The Weather Research and Forecasting (WRF) model is a numerical weather prediction system designed to serve both atmospheric research and operational forecasting needs. The WRF development is a done in collaboration around the globe. Furthermore, the WRF is used by academic atmospheric scientists, weather forecasters at the operational centers and so on. The WRF contains several physics components. The most time consuming one is the microphysics. One microphysics scheme is the Goddard cloud microphysics scheme. It is a sophisticated cloud microphysics scheme in the Weather Research and Forecasting (WRF) model. The Goddard microphysics scheme is very suitable for massively parallel computation as there are no interactions among horizontal grid points. Compared to the earlier microphysics schemes, the Goddard scheme incorporates a large number of improvements. Thus, we have optimized the Goddard scheme code. In this paper, we present our results of optimizing the Goddard microphysics scheme on Intel Many Integrated Core Architecture (MIC) hardware. The Intel Xeon Phi coprocessor is the first product based on Intel MIC architecture, and it consists of up to 61 cores connected by a high performance on-die bidirectional interconnect. The Intel MIC is capable of executing a full operating system and entire programs rather than just kernels as the GPU does. The MIC coprocessor supports all important Intel development tools. Thus, the development environment is one familiar to a vast number of CPU developers. Although, getting a maximum performance out of MICs will require using some novel optimization techniques. Those optimization techniques are discussed in this paper. The results show that the optimizations improved performance of Goddard microphysics scheme on Xeon Phi 7120P by a factor of 4.7×. In addition, the optimizations reduced the Goddard microphysics scheme's share of the total WRF processing time from 20.0 to 7.5%. Furthermore, the same optimizations

  2. The Light Ion Pulsed Power Induction Accelerator for ETF

    DTIC Science & Technology

    1995-07-01

    the technical development necessary to demonstrate scientific and engineering feasibility for fusion energy production with a reprated driver. In...order for ETF to be cost effective, the accelerator system must be able to drive several target chambers which will test various Inertial Fusion ... Energy (IFE) reactor technologies. We envision an elevator system positioning and removing multiple target chambers from the center area of the ion beam

  3. Accelerated aging and stabilization of radiation-vulcanized EPDM rubber

    NASA Astrophysics Data System (ADS)

    Basfar, A. A.; Abdel-Aziz, M. M.; Mofti, S.

    2000-03-01

    The effect of different antioxidants and their mixtures on the thermal aging and accelerated weathering of γ-radiation vulcanized EPDM rubber in presence of crosslinking coagent, was investigated. The compounds used were either a synergistic blend of phenolic and phosphite antioxidants, i.e. 1:4 Irganox 1076: Irgafos 168 or a blend of arylamine and quinoline type antioxidants, i.e. 1:1 IPPD: TMQ, at fixed concentration. Tinuvin 622 LD hindered amine light stabilized (HALS) was also used. The response was evaluated by the tensile strength and elongation at break for irradiated samples after thermal aging at 100°C for 28 days and accelerated weathering (Xenon test) up to 200 h.

  4. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies.

    PubMed

    Shu, Anthony; Collette, Andrew; Drake, Keith; Grün, Eberhard; Horányi, Mihály; Kempf, Sascha; Mocker, Anna; Munsat, Tobin; Northway, Paige; Srama, Ralf; Sternovsky, Zoltán; Thomas, Evan

    2012-07-01

    A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Institüt für Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10(-7) torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10(-10) torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

  5. Design of large vacuum chamber for VEC superconducting cyclotron beam line switching magnet

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Sumantra; Nandi, Chinmoy; Gayen, Subhasis; Roy, Suvadeep; Mishra, Santosh Kumar; Ramrao Bajirao, Sanjay; Pal, Gautam; Mallik, C.

    2012-11-01

    VEC K500 superconducting cyclotron will be used to accelerate heavy ion. The accelerated beam will be transported to different beam halls by using large switching magnets. The vacuum chamber for the switching magnet is around 1000 mm long. It has a height of 85 mm and width varying from 100 mm to 360 mm. The material for the chamber has been chosen as SS304.The material for the vacuum chamber for the switching magnet has been chosen as SS304. Design of the vessel was done as per ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. It was observed that primary stress values exceed the allowable limit. Since, the magnet was already designed with a fixed pole gap; increase of the vacuum chamber plate thickness restricts the space for beam transport. Design was optimized using stress analysis software ANSYS. Analysis was started using plate thickness of 4 mm. The stress was found higher than the allowable level. The analysis was repeated by increasing plate thickness to 6 mm, resulting in the reduction of stress level below the allowable level. In order to reduce the stress concentration due to sharp bend, chamfering was done at the corner, where the stress level was higher. The thickness of the plate at the corner was increased from 6 mm to 10 mm. These measures resulted in reduction of localized stress.

  6. High Intensity Tests of the NuMI Beam Monitoring Ionization Chambers

    NASA Astrophysics Data System (ADS)

    Zwaska, Robert

    2002-04-01

    The NuMI facility at Fermilab will generate an intense beam of neutrinos directed toward Soudan, MN, 735 km away. Components of the planned beam monitoring system will be exposed to fluences of up to 8 x 10^9 charge particles / cm^2 and 6 x 10^10 neutrons / cm^2 in an 8.6 us beam spill. These fluences will be measured by an array of Helium ionization chambers. We tested a pair of chambers with 8 GeV protons at the Fermilab Booster accelerator, and with high intensity neutron sources at the Texas Experimental Nuclear Facility.

  7. X-ray photoelectron spectroscopy and secondary electron yield analysis of Al and Cu samples exposed to an accelerator environment

    NASA Astrophysics Data System (ADS)

    Rosenberg, R. A.; McDowell, M. W.; Ma, Q.; Harkay, K. C.

    2003-09-01

    It is well known that exposure to an accelerator environment can cause ``conditioning'' of the vacuum chamber surfaces. In order to understand the manner in which the surface structure might influence the production of gases and electrons in the accelerator, such surfaces should be studied both before and after exposure to accelerator conditions. Numerous studies have been performed on representative materials prior to being inserted into an accelerator, but very little has been done on materials that have ``lived'' in the accelerator for extended periods. In the present work, we mounted Al and Cu coupons at different positions in a section of the Advanced Photon Source storage ring and removed them following exposures ranging from 6 to 18 months. X-ray photoelectron spectroscopy (XPS) of the surface was performed before and after exposure. Changes were observed that depended on the location and whether the coupon was facing the chamber interior or chamber wall. These results will be presented and compared to XPS and secondary electron yield data obtained from laboratory measurements meant to simulate the accelerator conditions.

  8. Twin-Screw Extruder and Pellet Accelerator Integration Developments for ITER

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

    Meitner, Steven J; Baylor, Larry R; Combs, Stephen Kirk

    The ITER pellet injection system consisting of a twinscrew frozen hydrogen isotope extruder, coupled to a combination solenoid actuated pellet cutter and pneumatic pellet accelerator, is under development at the Oak Ridge National Laboratory. A prototype extruder has been built to produce a continuous solid deuterium extrusion and will be integrated with a secondary section, where pellets are cut, chambered, and launched with a single-stage pneumatic accelerator into the plasma through a guide tube. This integrated pellet injection system is designed to provide 5 mm fueling pellets, injected at a rate up to 10 Hz, or 3 mm edge localizedmore » mode (ELM) triggering pellets, injected at higher rates up to 20 Hz. The pellet cutter, chamber mechanism, and the solenoid operated pneumatic valve for the accelerator are optimized to provide pellet velocities between 200-300 m/s to ensure high pellet survivability while traversing the inner wall fueling guide tubes, and outer wall ELMpacing guide tubes. This paper outlines the current twin-screwextruder design, pellet accelerator design, and the integrationrequired for both fueling and ELM pacing pellets.« less

  9. Salt weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures

    NASA Astrophysics Data System (ADS)

    Aly, Nevin; Gomez-Heras, Miguel; Hamed, Ayman; Alvarez de Buergo, Monica

    2013-04-01

    weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures Nevin Aly Mohamed (1), Miguel Gomez - Heras(2), Ayman Hamed Ahmed (1), and Monica Alvarez de Buergo(2). (1) Faculty of Pet. & Min. Engineering- Suez Canal University, Suez, Egypt, (2) Instituto de Geociencias (CSIC-UCM) Madrid. Spain. Limestone is one of the most frequent building stones in Egypt and is used since the time of ancient Egyptians and salt weathering is one of the main threats to its conservation. Most of the limestone used in historical monuments in Cairo is a biomicrite extracted from the Mid-Eocene Mokattam Group. During this work, cylindrical samples (2.4 cm diameter and approx. 4.8 cm length) were subjected, in a purpose-made simulation chamber, to simulated laboratory weathering tests with fixed salt concentration (10% weight NaCl solution), at different temperatures, which were kept constant throughout each test (10, 20, 30, 40 oC). During each test, salt solutions flowed continuously imbibing samples by capilarity. Humidity within the simulation chamber was reduced using silica gel to keep it low and constant to increase evaporation rate. Temperature, humidity inside the simulation chamber and samples weight were digitally monitored during each test. Results show the advantages of the proposed experimental methodology using a continuous flow of salt solutions and shed light on the effect of temperature on the dynamics of salt crystallization on and within samples. Research funded by mission sector of high education ministry, Egypt and Geomateriales S2009/MAT-1629.

  10. Potential and field produced by a uniform or non-uniform elliptical beam inside a confocal elliptic vacuum chamber

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

    Regenstreif, E.

    The potential produced by an isolated beam of elliptic cross-section seems to have been considered first by L.C. Teng. Image effects of line charges in elliptic vacuum chambers were introduced into accelerator theory by L. J. Laslett. Various approximate solutions for elliptic beams of finite cross-section coasting inside an elliptic vacuum chamber were subsequently proposed by P. Lapostolle and C. Bovet. A rigorous expression is derived for the potential produced by an elliptic beam inside an elliptic vacuum chamber, provided the beam envelope and the vacuum chamber can be assimilated to confocal ellipses.

  11. Global Acceleration of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Lara, Alejandro; Lepping, Ronald; Kaiser, Michael; Berdichevsky, Daniel; St. Cyr, O. Chris; Lazarus, Al

    1999-01-01

    Using the observed relation between speeds of coronal mass ejections (CMEs) near the Sun and in the solar wind, we estimate a global acceleration acting on the CMEs. Our study quantifies the qualitative results of Gosling [1997] and numerical simulations that CMEs at 1 AU with speeds closer to the solar wind. We found a linear relation between the global acceleration and the initial speed of the CMEs and the absolute value of the acceleration is similar to the slow solar wind acceleration. Our study naturally divides CMEs into fast and slow ones, the dividing line being the solar wind speed. Our results have important implications to space weather prediction models which need to incorporate this effect in estimating the CME arrival time at 1 AU. We show that the arrival times of CMEs at 1 AU are drastically different from the zero acceleration case.

  12. Carbonation-induced weathering effect on cesium retention of cement paste

    NASA Astrophysics Data System (ADS)

    Park, S. M.; Jang, J. G.

    2018-07-01

    Carbonation is inevitable for cement and concrete in repositories over an extended period of time. This study investigated the carbonation-induced weathering effect on cesium retention of cement. Cement paste samples were exposed to accelerated carbonation for different durations to simulate the extent of weathering among samples. The extent of carbonation in cement was characterized by XRD, TG and NMR spectroscopy, while the retention capacity for cesium was investigated by zeta potential measurement and batch adsorption tests. Though carbonation led to decalcification from the binder gel, it negatively charged the surface of cement hydrates and enhanced their cesium adsorption capacity.

  13. In situ baking method for degassing of a kicker magnet in accelerator beam line

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

    Kamiya, Junichiro, E-mail: kamiya.junichiro@jaea.go.jp; Ogiwara, Norio; Yanagibashi, Toru

    In this study, the authors propose a new in situ degassing method by which only kicker magnets in the accelerator beam line are baked out without raising the temperature of the vacuum chamber to prevent unwanted thermal expansion of the chamber. By simply installing the heater and thermal radiation shield plates between the kicker magnet and the chamber wall, most of the heat flux from the heater directs toward the kicker magnet. The result of the verification test showed that each part of the kicker magnet was heated to above the target temperature with a small rise in the vacuummore » chamber temperature. A graphite heater was selected in this application to bake-out the kicker magnet in the beam line to ensure reliability and easy maintainability of the heater. The vacuum characteristics of graphite were suitable for heater operation in the beam line. A preliminary heat-up test conducted in the accelerator beam line also showed that each part of the kicker magnet was successfully heated and that thermal expansion of the chamber was negligibly small.« less

  14. Accelerated Aging Test for Plastic Scintillator Gamma Ray Detectors

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

    Kouzes, Richard T.

    Polyvinyl toluene (PVT) and polystyrene (PS), collectively referred to as “plastic scintillator,” are synthetic polymer materials used to detect gamma radiation, and are commonly used in instrumentation. Recent studies have revealed that plastic scintillator undergoes an environmentally related material degradation that adversely affects performance under certain conditions and histories. A significant decrease in gamma ray sensitivity has been seen in some detectors in systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no agingmore » effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. It has been demonstrated that exposure of plastic scintillator in an environmental chamber to 30 days of high temperature and humidity (90% relative humidity and 55°C) followed by a single cycle to cold temperature (-30°C) will produce severe fogging in all PVT samples. This thermal cycle will be referred to as the “Accelerated Aging Test.” This document describes the procedure for performing this Accelerated Aging Test.« less

  15. Anthropogenically enhanced chemical weathering and carbon evasion in the Yangtze Basin

    PubMed Central

    Guo, Jingheng; Wang, Fushun; Vogt, Rolf David; Zhang, Yuhang; Liu, Cong-Qiang

    2015-01-01

    Chemical weathering is a fundamental geochemical process regulating the atmosphere-land-ocean fluxes and earth’s climate. It is under natural conditions driven primarily by weak carbonic acid that originates from atmosphere CO2 or soil respiration. Chemical weathering is therefore assumed as positively coupled with its CO2 consumption in contemporary geochemistry. Strong acids (i.e. sulfuric- and nitric acid) from anthropogenic sources have been found to influence the weathering rate and CO2 consumption, but their integrated effects remain absent in the world largest river basins. By interpreting the water chemistry and overall proton budget in the Yangtze Basin, we found that anthropogenic acidification had enhanced the chemical weathering by 40% during the past three decades, leading to an increase of 30% in solute discharged to the ocean. Moreover, substitution of carbonic acid by strong acids increased inorganic carbon evasion, offsetting 30% of the CO2 consumption by carbonic weathering. Our assessments show that anthropogenic loadings of sulfuric and nitrogen compounds accelerate chemical weathering but lower its CO2 sequestration. These findings have significant relevance to improving our contemporary global biogeochemical budgets. PMID:26150000

  16. Chemical vs. Physical Acceleration of Cement Hydration

    PubMed Central

    Bentz, Dale P.; Zunino, Franco; Lootens, Didier

    2016-01-01

    Cold weather concreting often requires the use of chemical accelerators to speed up the hydration reactions of the cement, so that setting and early-age strength development will occur in a timely manner. While calcium chloride (dihydrate – CaCl2·2H2O) is the most commonly used chemical accelerator, recent research using fine limestone powders has indicated their high proficiency for physically accelerating early-age hydration and reducing setting times. This paper presents a comparative study of the efficiency of these two approaches in accelerating hydration (as assessed via isothermal calorimetry), reducing setting times (Vicat needle), and increasing early-age mortar cube strength (1 d and 7 d). Both the CaCl2 and the fine limestone powder are used to replace a portion of the finest sand in the mortar mixtures, while keeping both the water-to-cement ratio and volume fractions of water and cement constant. Studies are conducted at 73.4 °F (23°C) and 50 °F (10 °C), so that activation energies can be estimated for the hydration and setting processes. Because the mechanisms of acceleration of the CaCl2 and limestone powder are different, a hybrid mixture with 1 % CaCl2 and 20 % limestone powder (by mass of cement) is also investigated. Both technologies are found to be viable options for reducing setting times and increasing early-age strengths, and it is hoped that concrete producers and contractors will consider the addition of fine limestone powder to their toolbox of techniques for assuring performance in cold weather and other concreting conditions where acceleration may be needed. PMID:28077884

  17. Weather.

    ERIC Educational Resources Information Center

    Ruth, Amy, Ed.

    1996-01-01

    This theme issue of "The Goldfinch" focuses on weather in Iowa and weather lore. The bulletin contains historical articles, fiction, activities, and maps. The table of contents lists: (1) "Wild Rosie's Map"; (2) "History Mystery"; (3) "Iowa's Weather History"; (4) "Weather Wonders"; (6)…

  18. Solutions for discharge chamber sputtering and anode deposit spalling in small mercury ion thrusters

    NASA Technical Reports Server (NTRS)

    Power, J. L.; Hiznay, D. J.

    1975-01-01

    Proposed solutions to the problems of sputter erosion and sputtered material spalling in the discharge chamber of small mercury ion thrusters are presented. The accelerated life test evaluated three such proposed solutions: (1) the use of tantalum as a single low sputter yield material for the exposed surfaces of the discharge chamber components subject to sputtering, (2) the use of a severely roughened anode surface to improve the adhesion of the sputter-deposited coating, and (3) the use of a wire cloth anode surface in order to limit the size of any coating flakes which might spall from it. Because of the promising results obtained in the accelerated life test with anode surfaces roughened by grit-blasting, experiments were carried out to optimize the grit-blasting procedure. The experimental results and an optimal grit-blasting procedure are presented.

  19. Portable Hyperbaric Chamber

    NASA Technical Reports Server (NTRS)

    Schneider, William C. (Inventor); Locke, James P. (Inventor); DeLaFuente, Horacio (Inventor)

    2001-01-01

    A portable, collapsible hyperbaric chamber was developed. A toroidal inflatable skeleton provides initial structural support for the chamber, allowing the attendant and/or patient to enter the chamber. Oval hatches mate against bulkhead rings, and the hyperbaric chamber is pressurized. The hatches seal against an o-ring, and the internal pressure of the chamber provides the required pressure against the hatch to maintain an airtight seal. In the preferred embodiment, the hyperbaric chamber has an airlock to allow the attendant to enter and exit the patient chamber during treatment. Visual communication is provided through portholes in the patient and/or airlock chamber. Life monitoring and support systems are in communication with the interior of the hyperbaric chamber and/or airlock chamber through conduits and/or sealed feed-through connectors into the hyperbaric chamber.

  20. Determination of the thermal and epithermal neutron sensitivities of an LBO chamber.

    PubMed

    Endo, Satoru; Sato, Hitoshi; Shimazaki, Takuto; Nakajima, Erika; Kotani, Kei; Suda, Mitsuru; Hamano, Tsuyoshi; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Hoshi, Masaharu

    2017-08-01

    An LBO (Li 2 B 4 O 7 ) walled ionization chamber was designed to monitor the epithermal neutron fluence in boron neutron capture therapy clinical irradiation. The thermal and epithermal neutron sensitivities of the device were evaluated using accelerator neutrons from the 9 Be(d, n) reaction at a deuteron energy of 4 MeV (4 MeV d-Be neutrons). The response of the chamber in terms of the electric charge induced in the LBO chamber was compared with the thermal and epithermal neutron fluences measured using the gold-foil activation method. The thermal and epithermal neutron sensitivities obtained were expressed in units of pC cm 2 , i.e., from the chamber response divided by neutron fluence (cm -2 ). The measured LBO chamber sensitivities were 2.23 × 10 -7  ± 0.34 × 10 -7 (pC cm 2 ) for thermal neutrons and 2.00 × 10 -5  ± 0.12 × 10 -5 (pC cm 2 ) for epithermal neutrons. This shows that the LBO chamber is sufficiently sensitive to epithermal neutrons to be useful for epithermal neutron monitoring in BNCT irradiation.

  1. Modeling of Particle Acceleration at Multiple Shocks via Diffusive Shock Acceleration: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Parker, L. Neergaard; Zank, G. P.

    2013-01-01

    Successful forecasting of energetic particle events in space weather models require algorithms for correctly predicting the spectrum of ions accelerated from a background population of charged particles. We present preliminary results from a model that diffusively accelerates particles at multiple shocks. Our basic approach is related to box models in which a distribution of particles is diffusively accelerated inside the box while simultaneously experiencing decompression through adiabatic expansion and losses from the convection and diffusion of particles outside the box. We adiabatically decompress the accelerated particle distribution between each shock by either the method explored in Melrose and Pope (1993) and Pope and Melrose (1994) or by the approach set forth in Zank et al. (2000) where we solve the transport equation by a method analogous to operator splitting. The second method incorporates the additional loss terms of convection and diffusion and allows for the use of a variable time between shocks. We use a maximum injection energy (E(sub max)) appropriate for quasi-parallel and quasi-perpendicular shocks and provide a preliminary application of the diffusive acceleration of particles by multiple shocks with frequencies appropriate for solar maximum (i.e., a non-Markovian process).

  2. The Proton Synchrotron (PS): At the Core of the CERN Accelerators

    NASA Astrophysics Data System (ADS)

    Cundy, Donald; Gilardoni, Simone

    The following sections are included: * Introduction * Extraction: Getting the Beam to Leave the Accelerator * Acceleration and Bunch Gymnastics * Boosting PS Beam Intensity * Capacitive Energy Storage Replaces Flywheel * Taking the Neutrinos by the Horns * OMEGA: Towards the Electronic Bubble Chamber * ISOLDE: Targeting a New Era in Nuclear Physics * The CERN n_TOF Facility: Catching Neutrons on the Fly * References

  3. The role of synoptic weather variability in Greenland ice sheet dynamics

    NASA Astrophysics Data System (ADS)

    Walker, J. M.; Radic, V.

    2017-12-01

    Much of the large uncertainty in predictions of future global sea level rise is due to our limited understanding of Greenland ice sheet (GrIS) motion and its interactions with climate. Over the next century, climate models predict that the GrIS will experience not only gradual warming, but also changes in atmospheric circulation, hydrology, and weather, including a northward shift of the North Atlantic storm track, with greater frequency and intensity of rain storms over the GrIS. Recent studies of GrIS dynamics have focused on the effects of increased seasonal mean meltwater on ice velocities, finding only a modest impact due to compensation by subglacial drainage systems, but subglacial hydraulic theory indicates that variability on shorter timescales is also relevant: short-term surges in meltwater or rainfall can overload drainage systems at rates faster than they can adjust, leading to water pressure spikes and ice acceleration. If the magnitude or frequency of these transient ice accelerations increase substantially as synoptic weather patterns change over the next century, there could be a significant cumulative impact on seasonal mean ice velocities. However, this issue has not been addressed in the literature and represents a major source of uncertainty. In this study, we investigate the role of synoptic weather variability in GrIS dynamics, with the ultimate goal of evaluating the relationships between extreme weather events and ice sheet flow in different seasons and regions of the GrIS. As a first step, we apply the machine learning technique of self-organizing maps to atmospheric reanalysis data to categorize the predominant synoptic weather systems over the GrIS domain, evaluating atmospheric moisture transport and rainfall to assess the impacts of each weather system on GrIS surface hydrology. The preliminary results presented here will be used in conjunction with ice velocity satellite measurements in future work, to identify any correlations

  4. ION ACCELERATION SYSTEM

    DOEpatents

    Luce, J.S.; Martin, J.A.

    1960-02-23

    Well focused, intense ion beams are obtained by providing a multi- apertured source grid in front of an ion source chamber and an accelerating multi- apertured grid closely spaced from and in alignment with the source grid. The longest dimensions of the elongated apertures in the grids are normal to the direction of the magnetic field used with the device. Large ion currents may be withdrawn from the source, since they do not pass through any small focal region between the grids.

  5. Exposure chamber

    DOEpatents

    Moss, Owen R.

    1980-01-01

    A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

  6. Irradiation chamber and sample changer for biological samples

    NASA Astrophysics Data System (ADS)

    Kraft, G.; Daues, H. W.; Fischer, B.; Kopf, U.; Liebold, H. P.; Quis, D.; Stelzer, H.; Kiefer, J.; Schöpfer, F.; Schneider, E.; Weber, K.; Wulf, H.; Dertinger, H.

    1980-01-01

    This paper describes an irradiation system with which living cells of different origin are irradiated with heavy ion beams (18⩽ Z⩽92) at energies up to 10 MeV/amu. The system consists of a beam monitor connected to the vacuum system of the accelerator and the irradiation chamber, containing the biological samples under atmospheric pressure. The requirements and aims of the set up are discussed. The first results with saccharomyces cerevisiae and Chinese Hamster tissue cells are presented.

  7. Weathering Characteristics of Wood Plastic Composites Reinforced with Extracted or Delignified Wood Flour

    PubMed Central

    Chen, Yao; Stark, Nicole M.; Tshabalala, Mandla A.; Gao, Jianmin; Fan, Yongming

    2016-01-01

    This study investigated weathering performance of an HDPE wood plastic composite reinforced with extracted or delignified wood flour (WF). The wood flour was pre-extracted with three different solvents, toluene/ethanol (TE), acetone/water (AW), and hot water (HW), or sodium chlorite/acetic acid. The spectral properties of the composites before and after artificial weathering under accelerated conditions were characterized by Fourier transform infrared (FTIR) spectroscopy, the surface color parameters were analyzed using colorimetry, and the mechanical properties were determined by a flexural test. Weathering of WPC resulted in a surface lightening and a decrease in wood index (wood/HDPE) and flexural strength. WPCs that were reinforced with delignified wood flour showed higher ΔL* and ΔE* values, together with lower MOE and MOR retention ratios upon weathering when compared to those with non-extracted control and extracted WF. PMID:28773732

  8. Effect of mouthwash and accelerated aging on the color stability of esthetic restorative materials.

    PubMed

    Lee, Y K; El Zawahry, M; Noaman, K M; Powers, J M

    2000-06-01

    To evaluate the color stability of esthetic restorative materials after immersion in mouthwashes and accelerated aging. Compomers and resin-based composites (RBC) were measured at baseline and repeatedly after immersion in three kinds of mouthwash (Listerine, Peridex, Rembrandt Age Defying) for 24 hrs and 7 days, and after aging for 150 kJ/m2. Color was measured according to CIE L*a*b* color scale on a reflection spectrophotometer. After immersion for 7 days, the mouthwash groups did not produce significantly higher color changes than the distilled water group, except with some mouthwashes used with Tetric-Ceram. After immersion for 7 days and aging for 150 kJ/m2, the mouthwash groups did not produce significantly higher color changes than the distilled water group. Aging in weathering chamber produced color change (deltaE*) of 1.1-3.9, which was mainly influenced by the material. With some exceptions, the color changes from immersion of the RBCs and compomers in mouthwashes were not perceptible (deltaE*<3.3).

  9. Turbojet-engine Starting and Acceleration

    NASA Technical Reports Server (NTRS)

    Mc Cafferty, R. J.; Straight, D. M.

    1956-01-01

    From considerations of safety and reliability in performance of gas-turbine aircraft, it is clear that engine starting and acceleration are of utmost importance. For this reason extensive efforts have been devoted to the investigation of the factors involved in the starting and acceleration of engines. In chapter III it is shown that certain basic combustion requirements must be met before ignition can occur; consequently, the design and operation of an engine must be tailored to provide these basic requirements in the combustion zone of the engine, particularly in the vicinity of the ignition source. It is pointed out in chapter III that ignition by electrical discharges is aided by high pressure, high temperature, low gas velocity and turbulence, gaseous fuel-air mixture, proper mixture strength, and-an optimum spark. duration. The simultaneous achievement of all these requirements in an actual turbojet-engine combustor is obviously impossible, yet any attempt to satisfy as many requirements as possible will result in lower ignition energies, lower-weight ignition systems, and greater reliability. These factors together with size and cost considerations determine the acceptability of the final ignition system. It is further shown in chapter III that the problem of wall quenching affects engine starting. For example, the dimensions of the volume to be burned must be larger than the quenching distance at the lowest pressure and the most adverse fuel-air ratio encountered. This fact affects the design of cross-fire tubes between adjacent combustion chambers in a tubular-combustor turbojet engine. Only two chambers in these engines contain spark plugs; therefore, the flame must propagate through small connecting tubes between the chambers. The quenching studies indicate that if the cross-fire tubes are too narrow the flame will not propagate from one chamber to another. In order to better understand the role of the basic factors in actual engine operation, many

  10. Centrifugal accelerator, system and method for removing unwanted layers from a surface

    DOEpatents

    Foster, Christopher A.; Fisher, Paul W.

    1995-01-01

    A cryoblasting process having a centrifugal accelerator for accelerating frozen pellets of argon or carbon dioxide toward a target area utilizes an accelerator throw wheel designed to induce, during operation, the creation of a low-friction gas bearing within internal passages of the wheel which would otherwise retard acceleration of the pellets as they move through the passages. An associated system and method for removing paint from a surface with cryoblasting techniques involves the treating, such as a preheating, of the painted surface to soften the paint prior to the impacting of frozen pellets thereagainst to increase the rate of paint removal. A system and method for producing large quantities of frozen pellets from a liquid material, such as liquid argon or carbon dioxide, for use in a cryoblasting process utilizes a chamber into which the liquid material is introduced in the form of a jet which disintegrates into droplets. A non-condensible gas, such as inert helium or air, is injected into the chamber at a controlled rate so that the droplets freeze into bodies of relatively high density.

  11. Effect of acoustic coupling on power-law flame acceleration in spherical confinement

    NASA Astrophysics Data System (ADS)

    Akkerman, V'yacheslav; Law, Chung K.

    2013-01-01

    A model describing acoustically-generated parametric instability in a spherical chamber is developed for quasi-one-dimensional, low-Mach number flames. We demonstrate how sound waves generated by a centrally-ignited, outwardly-propagating accelerating flamefront can be incorporated into an existing theory of self-similar flame acceleration in free space [V. Akkerman, C. K. Law, and V. Bychkov, "Self-similar accelerative propagation of expanding wrinkled flames and explosion triggering," Phys. Rev. E 83, 026305 (2011)], 10.1103/PhysRevE.83.026305. Being reflected from the chamber wall, flame-generated acoustics interact with the flamefront and the attendant hydrodynamic flamefront cellular instability. This in turn affects the subsequent flame morphology and propagation speed. It is shown that the acoustics modify the power-law flame acceleration, concomitantly facilitating or inhibiting the transition to detonation in confinement, which allows reconciliation of a discrepancy in experimental measurements of different groups.

  12. Numerical study of gravity effects on phase separation in a swirl chamber.

    PubMed

    Hsiao, Chao-Tsung; Ma, Jingsen; Chahine, Georges L

    2016-01-01

    The effects of gravity on a phase separator are studied numerically using an Eulerian/Lagrangian two-phase flow approach. The separator utilizes high intensity swirl to separate bubbles from the liquid. The two-phase flow enters tangentially a cylindrical swirl chamber and rotate around the cylinder axis. On earth, as the bubbles are captured by the vortex formed inside the swirl chamber due to the centripetal force, they also experience the buoyancy force due to gravity. In a reduced or zero gravity environment buoyancy is reduced or inexistent and capture of the bubbles by the vortex is modified. The present numerical simulations enable study of the relative importance of the acceleration of gravity on the bubble capture by the swirl flow in the separator. In absence of gravity, the bubbles get stratified depending on their sizes, with the larger bubbles entering the core region earlier than the smaller ones. However, in presence of gravity, stratification is more complex as the two acceleration fields - due to gravity and to rotation - compete or combine during the bubble capture.

  13. Accelerated Weathering of Waste Glass at 90°C with the Pressurized Unsaturated Flow (PUF) Apparatus: Implications for Predicting Glass Corrosion with a Reactive Transport Model

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

    Pierce, Eric M.; Bacon, Diana H.

    2009-09-21

    The interest in the long-term durability of waste glass stems from the need to predict radionuclide release rates from the corroding glass over geologic time-scales. Several long-term test methods have been developed to accelerate the glass-water reaction [drip test, vapor hydration test, product consistency test-B, and pressurized unsaturated flow (PUF)]. Currently, the PUF test is the only method that can mimic the unsaturated hydraulic properties expected in a subsurface disposal facility and simultaneously monitor the glass-water reaction. PUF tests are being conducted to accelerate the weathering of glass and validate the model parameters being used to predict long-term glass behavior.more » One dimensional reactive chemical transport simulations of glass dissolution and secondary phase formation during a 1.5-year long PUF experiment was conducted with the subsurface transport over reactive multi-phases (STORM) code. Results show that parameterization of the computer model by combining direct laboratory measurements and thermodynamic data provides an integrated approach to predicting glass behavior over geologic-time scales.« less

  14. Office-like Test Chambers to Measure Cool Roof Energy Savings in Four Indian Climates

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

    Arumugam, Rathish; B, Sasank; T, Rajappa

    Selecting a high albedo (solar reflectance) waterproofing layer on the top of a roof helps lower the roof’s surface temperature and reduce the air conditioning energy consumption in the top floor of a building. The annual energy savings depend on factors including weather, internal loads, and building operation schedule. To demonstrate the energy saving potential of high albedo roofs, an apparatus consisting of two nearly identical test chambers (A and B) has been built in four Indian climates: Chennai (hot & humid), Bangalore (temperate), Jhagadia (Hot & dry) and Delhi (composite). Each chamber has well-insulated walls to mimic the coremore » of an office building. Both chambers have the same construction, equipment, and operating schedule, differing only in roof surface. The reinforced cement concrete roof of Chamber A is surfaced with a low-albedo cement layer, while that of Chamber B is surfaced with a high-albedo water proof membrane (change in solar reflectance of 0.28). The experiment will be carried out for one year to explore seasonal variations in energy savings. Initial results in the month of July (post summer) shows that savings from high albedo roof ranges from 0.04 kWh/m2/day in temperate climates, to 0.08 kWh/m2/day in hot & dry climate.« less

  15. Boundary layer development as a function of chamber pressure in the NASA Lewis 1030:1 area ratio rocket nozzle

    NASA Technical Reports Server (NTRS)

    Smith, Tamara A.

    1988-01-01

    Through the use of theoretical predictions of fluid properties and experimental heat transfer and thrust measurements, the zones of laminar, transitional, and turbulent boundary layer flow were defined for the NASA Lewis 1039:1 area ratio rocket nozzle. Tests were performed on the nozzle at chamber pressures from 350 to 100 psia. For these conditions, the throat diameter Reynolds numbers varied from 300,000 to 1 million. The propellants used were gaseous hydrogen and gaseous oxygen. Thrust measurements and nozzle outer wall temperature measurements were taken during the 3-sec test runs. Comparison of experimental heat transfer and thrust data with the corresponding predictions from the Two-Dimensional Kinetics (TDK) nozzle analysis program indicated laminar flow in the nozzle at a throat diameter Reynolds number of 320,000 or chamber pressure of 360 psia. Comparison of experimental and predicted heat transfer data indicated transitional flow up to and including a chamber pressure of 1000 psia. Predicted values of the axisymmetric acceleration parameter within the convergent and divergent nozzle were consistent with the above results. Based upon an extrapolation of the heat transfer data and predicted distributions of the axisymmetric acceleration parameter, transitional flow was predicted up to a throat diameter Reynolds number of 220,000 or 2600-psia chamber pressure. Above 2600-psia chamber pressure, fully developed turbulent flow was predicted.

  16. Boundary layer development as a function of chamber pressure in the NASA Lewis 1030:1 area ratio rocket nozzle

    NASA Technical Reports Server (NTRS)

    Smith, Tamara A.

    1988-01-01

    Through the use of theoretical predictions of fluid properties and experimental heat transfer and thrust measurements, the zones of laminar, transitional, and turbulent boundary layer flow were defined for the NASA Lewis 1030:1 area ratio rocket nozzle. Tests were performed on the nozzle at chamber pressures from 350 to 100 psia. For these conditions, the throat diameter Reynolds numbers varied from 300,000 to 1 million. The propellants used were gaseous hydrogen and gaseous oxygen. Thrust measurements and nozzle outer wall temperature measurements were taken during the 3-sec test runs. Comparison of experimental heat transfer and thrust data with the corresponding predictions from the Two-Dimensional Kinetics (TDK) nozzle analysis program indicated laminar flow in the nozzle at a throat diameter Reynolds number of 320,000 or chamber pressure of 360 psia. Comparison of experimental and predicted heat transfer data indicated transitional flow up to and including a chamber pressure of 1000 psia. Predicted values of the axisymmetric acceleration parameter within the convergent and divergent nozzle were consistent with the above results. Based upon an extrapolation of the heat transfer data and predicted distributions of the axisymmetric acceleration parameter, transitional flow was predicted up to a throat diameter Reynolds number of 220,000 or 2600-psia chamber pressure. Above 2600-psia chamber pressure, fully developed turbulent flow was predicted.

  17. Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa

    PubMed Central

    Dirks, Paul HGM; Berger, Lee R; Roberts, Eric M; Kramers, Jan D; Hawks, John; Randolph-Quinney, Patrick S; Elliott, Marina; Musiba, Charles M; Churchill, Steven E; de Ruiter, Darryl J; Schmid, Peter; Backwell, Lucinda R; Belyanin, Georgy A; Boshoff, Pedro; Hunter, K Lindsay; Feuerriegel, Elen M; Gurtov, Alia; Harrison, James du G; Hunter, Rick; Kruger, Ashley; Morris, Hannah; Makhubela, Tebogo V; Peixotto, Becca; Tucker, Steven

    2015-01-01

    We describe the physical context of the Dinaledi Chamber within the Rising Star cave, South Africa, which contains the fossils of Homo naledi. Approximately 1550 specimens of hominin remains have been recovered from at least 15 individuals, representing a small portion of the total fossil content. Macro-vertebrate fossils are exclusively H. naledi, and occur within clay-rich sediments derived from in situ weathering, and exogenous clay and silt, which entered the chamber through fractures that prevented passage of coarser-grained material. The chamber was always in the dark zone, and not accessible to non-hominins. Bone taphonomy indicates that hominin individuals reached the chamber complete, with disarticulation occurring during/after deposition. Hominins accumulated over time as older laminated mudstone units and sediment along the cave floor were eroded. Preliminary evidence is consistent with deliberate body disposal in a single location, by a hominin species other than Homo sapiens, at an as-yet unknown date. DOI: http://dx.doi.org/10.7554/eLife.09561.001 PMID:26354289

  18. Quantification of the effect of plants on weathering: Studies in Iceland

    NASA Astrophysics Data System (ADS)

    Moulton, Katherine L.; Berner, Robert A.

    1998-10-01

    The weathering of calcium and magnesium silicate minerals on the continents has exerted a major control on atmospheric CO2 over geologic time, and vascular plants may have played an important role in this process. In western Iceland, we have examined the role of plants in weathering by measuring the chemistry of waters draining adjacent areas of basaltic rocks that are either barren (having a partial cover of mosses and lichens) or populated by trees. The study area was chosen to maximize vegetational differences and to minimize differences in microclimate, slope, and lithology, while avoiding hydrothermal waters and anthropogenic acid rain. Results, including data on cation uptake by growing trees, indicate that the rate of weathering release of Ca and Mg to streams and vegetation is two to five times higher in vegetated areas than the release of Ca and Mg to streams in barren areas. This finding suggests a major role for vascular plants in accelerating weathering and thereby lowering atmospheric CO2 as they invaded upland areas of the continents between 380 and 350 Ma.

  19. Uncertainty Quantification of Non-linear Oscillation Triggering in a Multi-injector Liquid-propellant Rocket Combustion Chamber

    NASA Astrophysics Data System (ADS)

    Popov, Pavel; Sideris, Athanasios; Sirignano, William

    2014-11-01

    We examine the non-linear dynamics of the transverse modes of combustion-driven acoustic instability in a liquid-propellant rocket engine. Triggering can occur, whereby small perturbations from mean conditions decay, while larger disturbances grow to a limit-cycle of amplitude that may compare to the mean pressure. For a deterministic perturbation, the system is also deterministic, computed by coupled finite-volume solvers at low computational cost for a single realization. The randomness of the triggering disturbance is captured by treating the injector flow rates, local pressure disturbances, and sudden acceleration of the entire combustion chamber as random variables. The combustor chamber with its many sub-fields resulting from many injector ports may be viewed as a multi-scale complex system wherein the developing acoustic oscillation is the emergent structure. Numerical simulation of the resulting stochastic PDE system is performed using the polynomial chaos expansion method. The overall probability of unstable growth is assessed in different regions of the parameter space. We address, in particular, the seven-injector, rectangular Purdue University experimental combustion chamber. In addition to the novel geometry, new features include disturbances caused by engine acceleration and unsteady thruster nozzle flow.

  20. A preliminary design of the collinear dielectric wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Zholents, A.; Gai, W.; Doran, S.; Lindberg, R.; Power, J. G.; Strelnikov, N.; Sun, Y.; Trakhtenberg, E.; Vasserman, I.; Jing, C.; Kanareykin, A.; Li, Y.; Gao, Q.; Shchegolkov, D. Y.; Simakov, E. I.

    2016-09-01

    A preliminary design of the multi-meter long collinear dielectric wakefield accelerator that achieves a highly efficient transfer of the drive bunch energy to the wakefields and to the witness bunch is considered. It is made from 0.5 m long accelerator modules containing a vacuum chamber with dielectric-lined walls, a quadrupole wiggler, an rf coupler, and BPM assembly. The single bunch breakup instability is a major limiting factor for accelerator efficiency, and the BNS damping is applied to obtain the stable multi-meter long propagation of a drive bunch. Numerical simulations using a 6D particle tracking computer code are performed and tolerances to various errors are defined.

  1. Convective Weather Avoidance with Uncertain Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots

  2. The Mobile Chamber

    NASA Technical Reports Server (NTRS)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  3. 45. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION DDD), ...

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

    45. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION DDD), VIEW LOOKING EAST. LEAD ENCLOSED PIPING IS DRAIN FROM BOILER CHAMBER No. 1 - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  4. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This month's insert, Severe Weather, has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in this poster are hurricanes,…

  5. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This article deals with a poster entitled, "Severe Weather," that has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in…

  6. Climate Change Mitigation through Enhanced Weathering in Bioenergy Crops

    NASA Astrophysics Data System (ADS)

    Kantola, I. B.; Masters, M. D.; Wolz, K. J.; DeLucia, E. H.

    2016-12-01

    Bioenergy crops are a renewable alternative to fossil fuels that reduce the net flux of CO2 to the atmosphere through carbon sequestration in plant tissues and soil. A portion of the remaining atmospheric CO2 is naturally mitigated by the chemical weathering of silica minerals, which sequester carbon as carbonates. The process of mineral weathering can be enhanced by crushing the minerals to increase surface area and applying them to agricultural soils, where warm temperatures, moisture, and plant roots and root exudates accelerate the weathering process. The carbonate byproducts of enhanced weathering are expected accumulate in soil water and reduce soil acidity, reduce nitrogen loss as N2O, and increase availability of certain soil nutrients. To determine the potential of enhanced weathering to alter the greenhouse gas balance in both annual (high disturbance, high fertilizer) and perennial (low disturbance, low fertilizer) bioenergy crops, finely ground basalt was applied to fields of maize, soybeans, and miscanthus at the University of Illinois Energy Farm. All plots showed an immediate soil temperature response at 10 cm depth, with increases of 1- 4 °C at midday. Early season CO2 and N2O fluxes mirrored soil temperature prior to canopy closure in all crops, while total N2O fluxes from miscanthus were lower than corn and soybeans in both basalt treatment and control plots. Mid-season N2O production was reduced in basalt-treated corn compared to controls. Given the increasing footprint of bioenergy crops, the ability to reduce GHG emissions in basalt-treated fields has the potential to mitigate atmospheric warming while benefitting soil fertility with the byproducts of weathering.

  7. Modeling of Particle Acceleration at Multiple Shocks Via Diffusive Shock Acceleration: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Parker, L. N.; Zank, G. P.

    2013-12-01

    Successful forecasting of energetic particle events in space weather models require algorithms for correctly predicting the spectrum of ions accelerated from a background population of charged particles. We present preliminary results from a model that diffusively accelerates particles at multiple shocks. Our basic approach is related to box models (Protheroe and Stanev, 1998; Moraal and Axford, 1983; Ball and Kirk, 1992; Drury et al., 1999) in which a distribution of particles is diffusively accelerated inside the box while simultaneously experiencing decompression through adiabatic expansion and losses from the convection and diffusion of particles outside the box (Melrose and Pope, 1993; Zank et al., 2000). We adiabatically decompress the accelerated particle distribution between each shock by either the method explored in Melrose and Pope (1993) and Pope and Melrose (1994) or by the approach set forth in Zank et al. (2000) where we solve the transport equation by a method analogous to operator splitting. The second method incorporates the additional loss terms of convection and diffusion and allows for the use of a variable time between shocks. We use a maximum injection energy (Emax) appropriate for quasi-parallel and quasi-perpendicular shocks (Zank et al., 2000, 2006; Dosch and Shalchi, 2010) and provide a preliminary application of the diffusive acceleration of particles by multiple shocks with frequencies appropriate for solar maximum (i.e., a non-Markovian process).

  8. Beam trapping in high-current cyclic accelerators with strong-focusing fields. Memorandum report, January-December 1984

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

    Sprangle, P.; Kapetanakos, C.A.

    1985-03-06

    In cyclic induction accelerators, the energy of the particles increases slowly in synchronism with the vertical (betatron) magnetic field. As a consequence of the slow acceleration, the charged particles must be confined by the weak-focusing magnetic field over long periods of time, and thus field errors, instabilities, and radiation losses can impose limitations on the acceleration process. These limitations can be substantially relaxed if the acceleration were to occur rapidly, say over a few microseconds. An appropriate name for such an accelerator is REBA-TRON (Rapid Electron Beam Accelerator). This paper considers a possible mechanism which could trap a high currentmore » electron beam in the strong focusing magnetic fields of the rebatron. We investigate a possible mechanism for trapping an intense relativistic electron beam confined by strong focusing fields. In our model the electron beam is assumed to be injected into torsatron fields off axis, near the chamber walls. The finite resistivity of the walls results in a drag force on the beam centroid which may cause the beam to spiral inward towards the axis of the chamber. We have analyzed this mechanism and obtained decay rates for the inward spiraling beam motion.« less

  9. Dynamic Multivariate Accelerated Corrosion Test Protocol

    DTIC Science & Technology

    2014-10-01

    atmospheric, accelerated, AA2024-T3, AA6061-T6, AA7075-T3, 1010 steel, AgCl, rare earth conversion coat, magnesium rich primer, polyurethane , Eyring, Monte...morphology and elemental analysis by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and electrochemical determinations of...in the FT-IR analysis; degradation of the components of the high performance polyurethane coatings exposed in the UV/ozone chamber were more

  10. QUANTITATIVE ULTRAVIOLET SPECTROSCOPY IN WEATHERING OF A MODEL POLYESTER-URETHANE COATING. (R828081E01)

    EPA Science Inventory

    Spectroscopy was used to quantify the effects of ultraviolet light on a model polyester–urethane coating as it degraded in an accelerated exposure chamber. An explorative calculation of the effective dosage absorbed by the coatings was made and, depending on the quantum...

  11. Two chamber reaction furnace

    DOEpatents

    Blaugher, Richard D.

    1998-05-05

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  12. Two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1998-05-05

    A vertical two chamber reaction furnace is described. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 C and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  13. Evaluating weather factors and material response during outdoor exposure to determine accelerated test protocols for predicting service life

    Treesearch

    R. Sam Williams; Steven Lacher; Corey Halpin; Christopher White

    2005-01-01

    To develop service life prediction methods for the study of sealants, a fully instrumented weather station was installed at an outdoor test site near Madison, WI. Temperature, relative humidiy, rainfall, ultraviolet (UV) radiation at 18 wavelengths, and wind speed and direction are being continuously measured and stored. The weather data can be integrated over time to...

  14. Multi-chamber deposition system

    DOEpatents

    Jacobson, Richard L.; Jeffrey, Frank R.; Westerberg, Roger K.

    1989-10-17

    A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

  15. Multi-chamber deposition system

    DOEpatents

    Jacobson, Richard L.; Jeffrey, Frank R.; Westerberg, Roger K.

    1989-06-27

    A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

  16. Weather Watch

    ERIC Educational Resources Information Center

    Bratt, Herschell Marvin

    1973-01-01

    Suggests a number of ways in which Federal Aviation Agency weather report printouts can be used in teaching the weather section of meteorology. These weather sequence reports can be obtained free of charge at most major airports. (JR)

  17. An online proton beam monitor for cancer therapy based on ionization chambers with micro pattern readout

    NASA Astrophysics Data System (ADS)

    Basile, E.; Carloni, A.; Castelluccio, D. M.; Cisbani, E.; Colilli, S.; De Angelis, G.; Fratoni, R.; Frullani, S.; Giuliani, F.; Gricia, M.; Lucentini, M.; Santavenere, F.; Vacca, G.

    2012-03-01

    A unique compact LINAC accelerator for proton therapy is under development in Italy within the TOP-IMPLART project. The proton beam will reach the kinetic energy of 230 MeV, it will have a widely variable current intensity (0.1-10 μA, with average up to 3.5 nA) associated with a high pulse repetition frequency (1-3.5 μs long pulses at 10-100 Hz). The TOP-IMPLART system will provide a fully active 3+1D dose delivery, that is longitudinal (energy modulation), transverse active spot scanning, and current intensity modulation. These accelerator features will permit a highly conformational dose distribution, which therefore requires an effective, online, beam monitor system with wide dynamic range, good sensitivity, adequate spatial resolution and rapid response. In order to fulfill these requisites a new device is under development for the monitoring of the beam intensity profile, its centroid and direction; it is based on transmission, segmented, ionization chambers with typical active area of 100 × 100 mm2. Micro pattern x/y pad like design has been used for the readout plane in order to maximize the field uniformity, reduce the chamber thickness and obtain both beam coordinates on a single chamber. The chamber prototype operates in ionization region to minimize saturation and discharge effects. Simulations (based on FLUKA) have been carried on to study the perturbation of the chamber on the beam parameters and the effects on the delivered dose (on a water phantom). The charge collected in each channel is integrated by dedicated auto-ranging readout electronics: an original scheme has been developed in order to have an input dynamic range greater than 104 with sensitivity better than 3%. This is achieved by a dynamical adjustment of the integrating capacitance to the signal intensity.

  18. Municipalities' Preparedness for Weather Hazards and Response to Weather Warnings

    PubMed Central

    Mehiriz, Kaddour; Gosselin, Pierre

    2016-01-01

    The study of the management of weather-related disaster risks by municipalities has attracted little attention even though these organizations play a key role in protecting the population from extreme meteorological conditions. This article contributes to filling this gap with new evidence on the level and determinants of Quebec municipalities’ preparedness for weather hazards and response to related weather warnings. Using survey data from municipal emergency management coordinators and secondary data on the financial and demographic characteristics of municipalities, the study shows that most Quebec municipalities are sufficiently prepared for weather hazards and undertake measures to protect the population when informed of imminent extreme weather events. Significant differences between municipalities were noted though. Specifically, the level of preparedness was positively correlated with the municipalities’ capacity and population support for weather-related disaster management policies. In addition, the risk of weather-related disasters increases the preparedness level through its effect on population support. We also found that the response to weather warnings depended on the risk of weather-related disasters, the preparedness level and the quality of weather warnings. These results highlight areas for improvement in the context of increasing frequency and/or severity of such events with current climate change. PMID:27649547

  19. Municipalities' Preparedness for Weather Hazards and Response to Weather Warnings.

    PubMed

    Mehiriz, Kaddour; Gosselin, Pierre

    2016-01-01

    The study of the management of weather-related disaster risks by municipalities has attracted little attention even though these organizations play a key role in protecting the population from extreme meteorological conditions. This article contributes to filling this gap with new evidence on the level and determinants of Quebec municipalities' preparedness for weather hazards and response to related weather warnings. Using survey data from municipal emergency management coordinators and secondary data on the financial and demographic characteristics of municipalities, the study shows that most Quebec municipalities are sufficiently prepared for weather hazards and undertake measures to protect the population when informed of imminent extreme weather events. Significant differences between municipalities were noted though. Specifically, the level of preparedness was positively correlated with the municipalities' capacity and population support for weather-related disaster management policies. In addition, the risk of weather-related disasters increases the preparedness level through its effect on population support. We also found that the response to weather warnings depended on the risk of weather-related disasters, the preparedness level and the quality of weather warnings. These results highlight areas for improvement in the context of increasing frequency and/or severity of such events with current climate change.

  20. Alternative uses of a megavolt tandem accelerator for few-keV studies with ion-source SIMS monitoring.

    PubMed

    Mello, S L A; Codeço, C F S; Magnani, B F; Sant'Anna, M M

    2016-06-01

    We increase the versatility of a tandem electrostatic accelerator by implementing simple modifications to the standard operation procedure. While keeping its ability to deliver MeV ion beams, we show that the experimental setup can (i) provide good quality ion beams in the few-keV energy range and (ii) be used to study ion-beam surface modification with simultaneous secondary ion mass spectrometry. This latter task is accomplished without using any chamber connected to the accelerator exit. We perform mass spectrometry of the few-keV anions produced in the ion source by measuring their neutral counterparts at the accelerator exit with energies up to 1.7 MeV. With an additional modification, a high-current few-keV regime is obtained, using the ion source as an irradiation chamber and the accelerator itself only as a mass spectrometer. As an example of application, we prepare a sample for the study of ion-beam assisted dewetting of a thin Au film on a Si substrate.

  1. Alternative uses of a megavolt tandem accelerator for few-keV studies with ion-source SIMS monitoring

    NASA Astrophysics Data System (ADS)

    Mello, S. L. A.; Codeço, C. F. S.; Magnani, B. F.; Sant'Anna, M. M.

    2016-06-01

    We increase the versatility of a tandem electrostatic accelerator by implementing simple modifications to the standard operation procedure. While keeping its ability to deliver MeV ion beams, we show that the experimental setup can (i) provide good quality ion beams in the few-keV energy range and (ii) be used to study ion-beam surface modification with simultaneous secondary ion mass spectrometry. This latter task is accomplished without using any chamber connected to the accelerator exit. We perform mass spectrometry of the few-keV anions produced in the ion source by measuring their neutral counterparts at the accelerator exit with energies up to 1.7 MeV. With an additional modification, a high-current few-keV regime is obtained, using the ion source as an irradiation chamber and the accelerator itself only as a mass spectrometer. As an example of application, we prepare a sample for the study of ion-beam assisted dewetting of a thin Au film on a Si substrate.

  2. STEREO Space Weather and the Space Weather Beacon

    NASA Technical Reports Server (NTRS)

    Biesecker, D. A.; Webb, D F.; SaintCyr, O. C.

    2007-01-01

    The Solar Terrestrial Relations Observatory (STEREO) is first and foremost a solar and interplanetary research mission, with one of the natural applications being in the area of space weather. The obvious potential for space weather applications is so great that NOAA has worked to incorporate the real-time data into their forecast center as much as possible. A subset of the STEREO data will be continuously downlinked in a real-time broadcast mode, called the Space Weather Beacon. Within the research community there has been considerable interest in conducting space weather related research with STEREO. Some of this research is geared towards making an immediate impact while other work is still very much in the research domain. There are many areas where STEREO might contribute and we cannot predict where all the successes will come. Here we discuss how STEREO will contribute to space weather and many of the specific research projects proposed to address STEREO space weather issues. We also discuss some specific uses of the STEREO data in the NOAA Space Environment Center.

  3. Determining mineral weathering rates based on solid and solute weathering gradients and velocities: Application to biotite weathering in saprolites

    USGS Publications Warehouse

    White, A.F.

    2002-01-01

    Chemical weathering gradients are defined by the changes in the measured elemental concentrations in solids and pore waters with depth in soils and regoliths. An increase in the mineral weathering rate increases the change in these concentrations with depth while increases in the weathering velocity decrease the change. The solid-state weathering velocity is the rate at which the weathering front propagates through the regolith and the solute weathering velocity is equivalent to the rate of pore water infiltration. These relationships provide a unifying approach to calculating both solid and solute weathering rates from the respective ratios of the weathering velocities and gradients. Contemporary weathering rates based on solute residence times can be directly compared to long-term past weathering based on changes in regolith composition. Both rates incorporate identical parameters describing mineral abundance, stoichiometry, and surface area. Weathering gradients were used to calculate biotite weathering rates in saprolitic regoliths in the Piedmont of Northern Georgia, USA and in Luquillo Mountains of Puerto Rico. Solid-state weathering gradients for Mg and K at Panola produced reaction rates of 3 to 6 x 10-17 mol m-2 s-1 for biotite. Faster weathering rates of 1.8 to 3.6 ?? 10-16 mol m-2 s-1 are calculated based on Mg and K pore water gradients in the Rio Icacos regolith. The relative rates are in agreement with a warmer and wetter tropical climate in Puerto Rico. Both natural rates are three to six orders of magnitude slower than reported experimental rates of biotite weathering. ?? 2002 Elsevier Science B.V. All rights reserved.

  4. Pilot weather advisor

    NASA Technical Reports Server (NTRS)

    Kilgore, W. A.; Seth, S.; Crabill, N. L.; Shipley, S. T.; Graffman, I.; Oneill, J.

    1992-01-01

    The results of the work performed by ViGYAN, Inc., to demonstrate the Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication system are presented. The Pilot Weather Advisor demonstrated that the technical problems involved with transmitting significant amount of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The Pilot Weather Advisor appears to be a viable solution for providing accurate and timely weather information for general aviation aircraft.

  5. Peltier-based cloud chamber

    NASA Astrophysics Data System (ADS)

    Nar, Sevda Yeliz; Cakir, Altan

    2018-02-01

    Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

  6. Evolution of the microstructure of unmodified and polymer modified asphalt binders with aging in an accelerated weathering tester.

    PubMed

    Menapace, Ilaria; Masad, Eyad

    2016-09-01

    This paper presents findings on the evolution of the surface microstructure of two asphalt binders, one unmodified and one polymer modified, directly exposed to aging agents with increasing durations. The aging is performed using an accelerated weathering tester, where ultraviolet radiation, oxygen and an increased temperature are applied to the asphalt binder surface. Ultraviolet and dark cycles, which simulated the succession of day and night, alternated during the aging process, and also the temperature varied, which corresponded to typical summer day and night temperatures registered in the state of Qatar. Direct aging of an exposed binder surface is more effective in showing microstructural modifications than previously applied protocols, which involved the heat treatment of binders previously aged with standardized methods. With the new protocol, any molecular rearrangements in the binder surface after aging induced by the heat treatment is prevented. Optical photos show the rippling and degradation of the binder surface due to aging. Microstructure images obtained by means of atomic force microscopy show gradual alteration of the surface due to aging. The original relatively flat microstructure was substituted with a profoundly different microstructure, which significantly protrudes from the surface, and is characterized by various shapes, such as rods, round structures and finally 'flower' or 'leaf' structures. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  7. Characterization of Lunar Swirls at Mare Ingenii: A Model for Space Weathering at Magnetic Anomalies

    NASA Technical Reports Server (NTRS)

    Kramer, Georgianna Y.; Combe, Jean-Philippe; Harnett, Erika M.; Hawke, Bernard Ray; Noble, Sarah K.; Blewett, David T.; McCord, Thomas B.; Giguere, Thomas A.

    2011-01-01

    Analysis of spectra from the Clementine ultraviolet-visible and near-infrared cameras of small, immature craters and surface soils both on and adjacent to the lunar swirls at Marc Ingenii has yielded the following conclusions about space weathering at a magnetic anomaly. (l) Despite having spectral characteristics of immaturity, the lunar swirls arc not freshly exposed surfaces. (2) The swirl surfaces arc regions of retarded weathering, while immediately adjacent regions experience accelerated weathering, (3) Weathering in the off-swirl regions darkens and flattens the spectrum with little to no reddening, which suggests that the production of larger (greater than 40 nm) nanophase iron dominates in these locations as a result of charged particle sorting by the magnetic field. Preliminaty analysis of two other lunar swirl regions, Reiner Gamma and Mare Marginis, is consistent with our observations at Mare Ingenii. Our results indicate that sputtering/vapor deposition, implanted solar wind hydrogen, and agglutination share responsibility for creating the range in npFe(sup 0) particle sizes responsible for the spectral effects of space weathering.

  8. Evaluation of the US Department of Energy Weatherization Innovation Pilot Program (2010-2014)

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

    Tonn, Bruce Edward; Rose, Erin M.; Hawkins, Beth A.

    This report contains results from analysis conducted on each of the Weatherization Innovation Pilot Program (WIPP) grants awarded to 16 organizations by the US Department of Energy (DOE) in 2010. The purpose of WIPP was to explore the potential adoptability or replicability of innovative processes or technologies for the enhancement of DOE’s Weatherization Assistance Program (WAP). DOE initiated the WIPP grant to accelerate effective innovations in home energy efficiency and other WAP mission-related goals for income-qualifying households of low socioeconomic status. This study was performed alongside a broader, national evaluation of WAP conducted by Oak Ridge National Laboratory (ORNL) formore » DOE.« less

  9. Weather Information System

    NASA Technical Reports Server (NTRS)

    1995-01-01

    WxLink is an aviation weather system based on advanced airborne sensors, precise positioning available from the satellite-based Global Positioning System, cockpit graphics and a low-cost datalink. It is a two-way system that uplinks weather information to the aircraft and downlinks automatic pilot reports of weather conditions aloft. Manufactured by ARNAV Systems, Inc., the original technology came from Langley Research Center's cockpit weather information system, CWIN (Cockpit Weather INformation). The system creates radar maps of storms, lightning and reports of surface observations, offering improved safety, better weather monitoring and substantial fuel savings.

  10. Using Weather Types to Understand and Communicate Weather and Climate Impacts

    NASA Astrophysics Data System (ADS)

    Prein, A. F.; Hale, B.; Holland, G. J.; Bruyere, C. L.; Done, J.; Mearns, L.

    2017-12-01

    A common challenge in atmospheric research is the translation of scientific advancements and breakthroughs to decision relevant and actionable information. This challenge is central to the mission of NCAR's Capacity Center for Climate and Weather Extremes (C3WE, www.c3we.ucar.edu). C3WE advances our understanding of weather and climate impacts and integrates these advances with distributed information technology to create tools that promote a global culture of resilience to weather and climate extremes. Here we will present an interactive web-based tool that connects historic U.S. losses and fatalities from extreme weather and climate events to 12 large-scale weather types. Weather types are dominant weather situations such as winter high-pressure systems over the U.S. leading to very cold temperatures or summertime moist humid air masses over the central U.S. leading to severe thunderstorms. Each weather type has a specific fingerprint of economic losses and fatalities in a region that is quantified. Therefore, weather types enable a direct connection of observed or forecasted weather situation to loss of life and property. The presented tool allows the user to explore these connections, raise awareness of existing vulnerabilities, and build resilience to weather and climate extremes.

  11. Emulsion chamber observations and interpretation (HE 3)

    NASA Technical Reports Server (NTRS)

    Shibata, M.

    1986-01-01

    Experimental results from Emulsion Chamber (EC) experiments at mountain altitudes or at higher levels using flying carriers are examined. The physical interest in this field is concentrated on the strong interaction at the very high energy region exceeding the accelerator energy, also on the primary cosmic ray intensity and its chemical composition. Those experiments which observed cosmic ray secondaries gave information on high energy interaction characteristics through the analyses of secondary spectra, gamma-hadron families and C-jets (direct observation of the particle production occuring at the carbon target). Problems of scaling violation in fragmentation region, interaction cross section, transverse momentum of produced secondaries, and some peculiar features of exotic events are discussed.

  12. GEOSS interoperability for Weather, Ocean and Water

    NASA Astrophysics Data System (ADS)

    Richardson, David; Nyenhuis, Michael; Zsoter, Ervin; Pappenberger, Florian

    2013-04-01

    "Understanding the Earth system — its weather, climate, oceans, atmosphere, water, land, geodynamics, natural resources, ecosystems, and natural and human-induced hazards — is crucial to enhancing human health, safety and welfare, alleviating human suffering including poverty, protecting the global environment, reducing disaster losses, and achieving sustainable development. Observations of the Earth system constitute critical input for advancing this understanding." With this in mind, the Group on Earth Observations (GEO) started implementing the Global Earth Observation System of Systems (GEOSS). GEOWOW, short for "GEOSS interoperability for Weather, Ocean and Water", is supporting this objective. GEOWOW's main challenge is to improve Earth observation data discovery, accessibility and exploitability, and to evolve GEOSS in terms of interoperability, standardization and functionality. One of the main goals behind the GEOWOW project is to demonstrate the value of the TIGGE archive in interdisciplinary applications, providing a vast amount of useful and easily accessible information to the users through the GEO Common Infrastructure (GCI). GEOWOW aims at developing funcionalities that will allow easy discovery, access and use of TIGGE archive data and of in-situ observations, e.g. from the Global Runoff Data Centre (GRDC), to support applications such as river discharge forecasting.TIGGE (THORPEX Interactive Grand Global Ensemble) is a key component of THORPEX: a World Weather Research Programme to accelerate the improvements in the accuracy of 1-day to 2 week high-impact weather forecasts for the benefit of humanity. The TIGGE archive consists of ensemble weather forecast data from ten global NWP centres, starting from October 2006, which has been made available for scientific research. The TIGGE archive has been used to analyse hydro-meteorological forecasts of flooding in Europe as well as in China. In general the analysis has been favourable in terms of

  13. Using Space Weather for Enhanced, Extreme Terrestrial Weather Predictions.

    NASA Astrophysics Data System (ADS)

    McKenna, M. H.; Lee, T. A., III

    2017-12-01

    Considering the complexities of the Sun-Earth system, the impacts of space weather to weather here on Earth are not fully understood. This study attempts to analyze this interrelationship by providing a theoretical framework for studying the varied modalities of solar inclination and explores the extent to which they contribute, both in formation and intensity, to extreme terrestrial weather. Using basic topologic and ontology engineering concepts (TOEC), the transdisciplinary syntaxes of space physics, geophysics, and meteorology are analyzed as a seamless interrelated system. This paper reports this investigation's initial findings and examines the validity of the question "Does space weather contribute to extreme weather on Earth, and if so, to what degree?"

  14. Characteristics of ageostrophic flow in the vicinity of a severe weather outbreak - AVE-SESAME I

    NASA Technical Reports Server (NTRS)

    Arnold, J. E.

    1982-01-01

    GOES satellite data was used to examine the ageostrophic flow in the vicinity of severe weather outbreaks along the Red River between Texas and Oklahoma in April 1979. The observations were part of the NASA AVE-SESAME I data on atmospheric states close to severe weather conditions. The Barnes Objective Analysis Technique was employed to analyze the data on a 100 km grid. The ageostrophic wind was defined on a regional scale from satellite data on different levels of cloud wind vectors, with a height change signalling a short-wave system in a long-wave trough. The percentage of deviation of the subgeostrophic winds from the geostrophic wind was calculated, and maximum departure corresponded with the region of greatest storm development. Time cross sections of additions to the ageostrophic flow were made as a function of pressure at 100 mb intervals from 900-100 mb. The ageostrophic acceleration was consistently twice the geostrophic acceleration.

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  16. Four top tier challenges for Space Weather Research for the next decade

    NASA Astrophysics Data System (ADS)

    Spann, James

    2017-04-01

    The science of space weather is that which (1) develops the knowledge and understanding to predict conditions in space that impact life and society, and (2) leads to operational solutions that protect assets and systems to the benefit of society. Advances over the past decades in this area of research have yielded amazing discoveries and significant strides toward fulfilling the promise of an operational solution to space weather, and have facilitated the enterprise to make its way into the realm of national and international policy. Even if the resources, technologies, and political will were available to take advantage of this progress, our current lack of understanding of space weather would prevent the implementation of a fully operational system. This talk will highlight four distinct areas of research that, if fully understood, could enable operational solutions to space weather impacts, given sufficient resources and political will. These areas are (a) trigger of solar variability, (b) acceleration of mass and energy in interplanetary space, (c) geoeffectiveness of solar wind, and (d) ionospheric variability. A brief description, technical challenges, and possible pathways to resolution will be offered for each of these areas.

  17. Chamber and Diffusive Based Carbon Flux Measurements in an Alaskan Arctic Ecosystem

    NASA Astrophysics Data System (ADS)

    Wilkman, E.; Oechel, W. C.; Zona, D.

    2013-12-01

    consumption, whereas chamber and eddy covariance methodologies only document net production from the surface. Also, the capability to measure spring, summer and fall chamber fluxes, and to continuously determine year-round CO2 and CH4 fluxes under even the most extreme weather conditions, allows an unprecedented level of data continuity and local spatial coverage. Comparison to a nearby eddy covariance tower measuring CO2 and CH4 fluxes with an LGR Fast Greenhouse Gas Analyzer add additional power to this set of measurements. Thus, inter-comparison between diffusive, chamber, and tower-based carbon fluxes should lend much insight into the spatial and temporal controls on carbon cycling in this ecosystem.

  18. Human-accelerated weathering increases salinization, major ions, and alkalinization in fresh water across land use

    EPA Science Inventory

    Human land use increases transport of dissolved inorganic carbon and major ions in watersheds due to the combination of easily weathered materials in watersheds and anthropogenic inputs. Here, we show that dissolved inorganic carbon (DIC), alkalinity, and major ions are significa...

  19. IONIZATION CHAMBER

    DOEpatents

    Redman, W.C.; Shonka, F.R.

    1958-02-18

    This patent describes a novel ionization chamber which is well suited to measuring the radioactivity of the various portions of a wire as the wire is moved at a uniform speed, in order to produce the neutron flux traverse pattern of a reactor in which the wire was previously exposed to neutron radiation. The ionization chamber of the present invention is characterized by the construction wherein the wire is passed through a tubular, straight electrode and radiation shielding material is disposed along the wire except at an intermediate, narrow area where the second electrode of the chamber is located.

  20. 50. BOILER CHAMBER No. 1, LOOKING SOUTHEAST BETWEEN CHAMBER AND ...

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

    50. BOILER CHAMBER No. 1, LOOKING SOUTHEAST BETWEEN CHAMBER AND ENCLOSURE (LOCATION III) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  1. Fun with Weather

    ERIC Educational Resources Information Center

    Yildirim, Rana

    2007-01-01

    This three-part weather-themed lesson for young learners connects weather, clothing, and feelings vocabulary. The target structures covered are: asking about the weather; comparing weather; using the modal auxiliary, should; and the question word, when. The lessons utilize all four skills and include such activities as going outside, singing,…

  2. 61. BOILER CHAMBER No. 2, LOOKING SOUTHWEST BETWEEN CHAMBER AND ...

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

    61. BOILER CHAMBER No. 2, LOOKING SOUTHWEST BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION PPP) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  3. 72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR ...

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

    72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR AND CANAL (LOCATION T) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  4. SU-F-T-458: Tracking Trends of TG-142 Parameters Via Analysis of Data Recorded by 2D Chamber Array

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

    Alexandrian, A; Kabat, C; Defoor, D

    Purpose: With increasing QA demands of medical physicists in clinical radiation oncology, the need for an effective method of tracking clinical data has become paramount. A tool was produced which scans through data automatically recorded by a 2D chamber array and extracts relevant information recommended by TG-142. Using this extracted information a timely and comprehensive analysis of QA parameters can be easily performed enabling efficient monthly checks on multiple linear accelerators simultaneously. Methods: A PTW STARCHECK chamber array was used to record several months of beam outputs from two Varian 2100 series linear accelerators and a Varian NovalisTx−. In conjunctionmore » with the chamber array, a beam quality phantom was used to simultaneously to determine beam quality. A minimalist GUI was created in MatLab that allows a user to set the file path of the data for each modality to be analyzed. These file paths are recorded to a MatLab structure and then subsequently accessed by a script written in Python (version 3.5.1) which then extracts values required to perform monthly checks as outlined by recommendations from TG-142. The script incorporates calculations to determine if the values recorded by the chamber array fall within an acceptable threshold. Results: Values obtained by the script are written to a spreadsheet where results can be easily viewed and annotated with a “pass” or “fail” and saved for further analysis. In addition to creating a new scheme for reviewing monthly checks, this application allows for able to succinctly store data for follow up analysis. Conclusion: By utilizing this tool, parameters recommended by TG-142 for multiple linear accelerators can be rapidly obtained and analyzed which can be used for evaluation of monthly checks.« less

  5. Accelerator Vacuum Protection System

    NASA Astrophysics Data System (ADS)

    Barua, Pradip; Kothari, Ashok; Archunan, M.; Joshi, Rajan

    2012-11-01

    A new and elaborate automatic vacuum protection system using fast acting valve has been installed to avoid accidental venting of accelerator from experimental chamber side. To cover all the beam lines and to reduce the system cost, it has been installed at a common point from where all the seven beam lines originate. The signals are obtained by placing fast response pressure sensing gauges (HV SENSOR) near all the experimental stations. The closing time of the fast valve is 10 milli-second. The fast closing system protects only one vacuum line at a time. At IUAC, we have seven beam lines so one sensor was placed in each of the beam lines near experimental chamber and a multiplexer was incorporated into the fast closing system. At the time of experiment, the sensor of the active beam line is selected through the multiplexer and the Fast closing valve is interlocked with the selected sensor. As soon as the pressure sensor senses the pressure rise beyond a selected pressure, the signal is transferred and the fast valve closes within 10 to 12 millisecond.

  6. 41. AUXILIARY CHAMBER, CONCRETE ENCLOSURE CHAMBER AIR LOCK (EXTERIOR), LOOKING ...

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

    41. AUXILIARY CHAMBER, CONCRETE ENCLOSURE CHAMBER AIR LOCK (EXTERIOR), LOOKING NORTHEAST FROM SOUTHWEST CORNER (LOCATION AAA) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  7. Weathering and landscape evolution

    NASA Astrophysics Data System (ADS)

    Turkington, Alice V.; Phillips, Jonathan D.; Campbell, Sean W.

    2005-04-01

    In recognition of the fundamental control exerted by weathering on landscape evolution and topographic development, the 35th Binghamton Geomorphology Symposium was convened under the theme of Weathering and Landscape Evolution. The papers and posters presented at the conference imparted the state-of-the-art in weathering geomorphology, tackled the issue of scale linkage in geomorphic studies and offered a vehicle for interdisciplinary communication on research into weathering and landscape evolution. The papers included in this special issue are encapsulated here under the general themes of weathering mantles, weathering and relative dating, weathering and denudation, weathering processes and controls and the 'big picture'.

  8. Evaluating Weathering of Food Packaging Polyethylene-Nano-clay Composites: Release of Nanoparticles and their Impacts.

    PubMed

    Han, Changseok; Zhao, Amy; Varughese, Eunice; Sahle-Demessie, E

    2018-01-01

    Nano-fillers are increasingly incorporated into polymeric materials to improve the mechanical, barrier or other matrix properties of nanocomposites used for consumer and industrial applications. However, over the life cycle, these nanocomposites could degrade due to exposure to environmental conditions, resulting in the release of embedded nanomaterials from the polymer matrix into the environment. This paper presents a rigorous study on the degradation and the release of nanomaterials from food packaging composites. Films of nano-clay-loaded low-density polyethylene (LDPE) composite for food packaging applications were prepared with the spherilene technology and exposed to accelerated weathering of ultraviolet (UV) irradiation or low concentration of ozone at 40 °C. The changes in the structural, surface morphology, chemical and physical properties of the films during accelerated weathering were investigated. Qualitative and quantitative changes in properties of pristine and aged materials and the release of nano-clay proceeded slowly until 130 hr irradiation and then accelerated afterward resulting complete degradation. Although nano-clay increased the stability of LDPE and improved thermal and barrier properties, they accelerated the UV oxidation of LDPE. With increasing exposure to UV, the surface roughness, chemiluminescence index, and carbonyl index of the samples increased while decreasing the intensity of the wide-angle X-ray diffraction pattern. Nano-clay particles with sizes ranging from 2-8 nm were released from UV and ozone weathered composite. The concentrations of released nanoparticles increased with an increase in aging time. Various toxicity tests, including reactive oxygen species generation and cell activity/viability were also performed on the released nano-clay and clay polymer. The released nano-clays basically did not show toxicity. Our combined results demonstrated the degradation properties of nano-clay particle-embedded LDPE composites

  9. 44. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION CCC), ...

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

    44. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION CCC), LOOKING NORTHEAST SHOWING DRAIN PIPE FROM SUMP - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  10. Acceleration of ions and neutrals by a traveling electrostatic wave

    NASA Astrophysics Data System (ADS)

    Lee, K. H.; Lee, L. C.; Wong, A. Y.

    2018-02-01

    We propose a new scheme for accelerating a weakly ionized gas by externally imposing a sinusoidal electrostatic (ES) potential in a tubular system. The weakly ionized gas consists of three fluid components: neutral hydrogen fluid ( H ), positively charged fluid ( H + ), and negatively charged fluids ( H - and/or e - ), as an example. The sinusoidal ES potential is imposed on a series of conductive meshes in the tubular system, and its phase varies with time and space to mimic a traveling ES wave. The charged fluids are trapped and accelerated by the sinusoidal ES potential, while the neutral fluid is accelerated through neutral-ion collisions. The neutral fluid can be accelerated to the wave phase velocity in a few neutral-ion collision times. The whole device remains charge-neutral, and there is no build-up of space charge. The acceleration scheme can be applied to, for example, the propulsion of glider in the air, partially ionized plasma in a chamber, spacecraft, and wind tunnel.

  11. Alternative uses of a megavolt tandem accelerator for few-keV studies with ion-source SIMS monitoring

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

    Mello, S. L. A., E-mail: smello@ufv.br; Codeço, C. F. S.; Magnani, B. F.

    2016-06-15

    We increase the versatility of a tandem electrostatic accelerator by implementing simple modifications to the standard operation procedure. While keeping its ability to deliver MeV ion beams, we show that the experimental setup can (i) provide good quality ion beams in the few-keV energy range and (ii) be used to study ion-beam surface modification with simultaneous secondary ion mass spectrometry. This latter task is accomplished without using any chamber connected to the accelerator exit. We perform mass spectrometry of the few-keV anions produced in the ion source by measuring their neutral counterparts at the accelerator exit with energies up tomore » 1.7 MeV. With an additional modification, a high-current few-keV regime is obtained, using the ion source as an irradiation chamber and the accelerator itself only as a mass spectrometer. As an example of application, we prepare a sample for the study of ion-beam assisted dewetting of a thin Au film on a Si substrate.« less

  12. The Active Target Time Projection Chamber at NSCL

    NASA Astrophysics Data System (ADS)

    Bazin, D.; Bradt, J.; Ayyad, Y.; Mittig, W.; Ahn, T.; Beceiro-Novo, S.; Carpenter, L.; Cortesi, M.; Fritsch, A.; Kolata, J. J.; Lynch, W.; Watwood, N.

    2017-11-01

    Reactions in inverse kinematics close to the Coulomb barrier offer unique opportunities to study exotic nuclei, but they are plagued by the difficulty to efficiently and precisely measure the characteristics of the emerging particles. The Active Target Time Projection Chamber (AT-TPC) offers an elegant solution to this dilemma. In this device, the detector gas of the time projection chamber is at the same time the target in which nuclear reactions take place. The use of this new paradigm offers several advantages over conventional inert target methods, the most significant being the ability to increase the luminosity of experiments without loss of resolution. The AT-TPC and some results obtained on resonant α scattering to explore the clustering properties of neutron-rich nuclei are presented, as well as fusion cross section results using a 10Be radioactive beam. In addition, the first re-accelerated radioactive beam experiment using the fully commissioned ReA3 linac was conducted recently at the NSCL with the AT-TPC, where proton resonant scattering of a 4.6 MeV/u 46Ar beam was used to measure the neutron single-particle strength in 47Ar.

  13. Characteristics of a 30-cm thruster operated with small hole accelerator grid ion optics

    NASA Technical Reports Server (NTRS)

    Vahrenkamp, R. P.

    1976-01-01

    Small hole accelerator grid ion optical systems have been tested as a possible means of improving 30-cm ion thruster performance. The effects of small hole grids on the critical aspects of thruster operation including discharge chamber performance, doubly-charged ion concentration, effluent beam characteristics, and plasma properties have been evaluated. In general, small hole accelerator grids are beneficial in improving thruster performance while maintaining low double ion ratios. However, extremely small accelerator aperture diameters tend to degrade beam divergence characteristics. A quantitative discussion of these advantages and disadvantages of small hole accelerator grids, as well as resulting variations in thruster operation characteristics, is presented.

  14. UTM Weather Presentation

    NASA Technical Reports Server (NTRS)

    Chan, William N.; Kopardekar, Parimal H.; Carmichael, Bruce; Cornman, Larry

    2017-01-01

    Presentation highlighting how weather affected UAS operations during the UTM field tests. Research to develop UAS weather translation models with a description of current and future work for UTM weather.

  15. Reconstruction of Historical Weather by Assimilating Old Weather Diary Data

    NASA Astrophysics Data System (ADS)

    Neluwala, P.; Yoshimura, K.; Toride, K.; Hirano, J.; Ichino, M.; Okazaki, A.

    2017-12-01

    Climate can control not only human life style but also other living beings. It is important to investigate historical climate to understand the current and future climates. Information about daily weather can give a better understanding of past life on earth. Long-term weather influences crop calendar as well as the development of civilizations. Unfortunately, existing reconstructed daily weather data are limited to 1850s due to the availability of instrumental data. The climate data prior to that are derived from proxy materials (e.g., tree-ring width, ice core isotopes, etc.) which are either in annual or decadal scale. However, there are many historical documents which contain information about weather such as personal diaries. In Japan, around 20 diaries in average during the 16th - 19th centuries have been collected and converted into a digitized form. As such, diary data exist in many other countries. This study aims to reconstruct historical daily weather during the 18th and 19th centuries using personal daily diaries which have analogue weather descriptions such as `cloudy' or `sunny'. A recent study has shown the possibility of assimilating coarse weather data using idealized experiments. We further extend this study by assimilating modern weather descriptions similar to diary data in recent periods. The Global Spectral model (GSM) of National Centers for Environmental Prediction (NCEP) is used to reconstruct weather with the Local Ensemble Kalman filter (LETKF). Descriptive data are first converted to model variables such as total cloud cover (TCC), solar radiation and precipitation using empirical relationships. Those variables are then assimilated on a daily basis after adding random errors to consider the uncertainty of actual diary data. The assimilation of downward short wave solar radiation using weather descriptions improves RMSE from 64.3 w/m2 to 33.0 w/m2 and correlation coefficient (R) from 0.5 to 0.8 compared with the case without any

  16. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  17. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1999-03-16

    A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  18. Differential acceleration in the final beam lines of a Heavy Ion Fusion driver

    DOE PAGES

    Friedman, Alex

    2013-10-19

    A long-standing challenge in the design of a Heavy Ion Fusion power plant is that the ion beams entering the target chamber, which number of order a hundred, all need to be routed from one or two multi-beam accelerators through a set of transport lines. The beams are divided into groups, which each have unique arrival times and may have unique kinetic energies. It is also necessary to arrange for each beam to enter the target chamber from a prescribed location on the periphery of that chamber. Furthermore, it has generally been assumed that additional constraints must be obeyed: thatmore » the path lengths of the beams in a group must be equal, and that any delay of \\main-pulse" beams relative to \\foot-pulse" beams must be provided by the insertion of large delay-arcs in the main beam transport lines. Here we introduce the notion of applying \\di erential acceleration" to individual beams or sets of beam at strategic stages of the transport lines. That is, by accelerating some beams \\sooner" and others \\later," it is possible to simplify the beam line con guration in a number of cases. For example, the time delay between the foot and main pulses can be generated without resorting to large arcs in the main-pulse beam lines. It is also possible to use di erential acceleration to e ect the simultaneous arrival on target of a set of beams ( e.g., for the foot-pulse) without requiring that their path lengths be precisely equal. We illustrate the technique for two model con gurations, one corresponding to a typical indirect-drive scenario requiring distinct foot and main energies, and the other to an ion-driven fast-ignition scenario wherein the foot and main beams share a common energy.« less

  19. Weatherization Innovation Pilot Program: Program Overview and Philadelphia Project Highlight (Fact Sheet)

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

    Not Available

    2012-01-01

    Case Study with WIPP program overview, information regarding eligibility, and successes from Pennsylvania's Commission on Economic Opportunity (CEO) that demonstrate innovative approaches that maximize the benefit of the program. The Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) recently launched the Weatherization Innovation Pilot Program (WIPP) to accelerate innovations in whole-house weatherization and advance DOE's goal of increasing the energy efficiency and health and safety of homes of low-income families. Since 2010, WIPP has helped weatherization service providers as well as new and nontraditional partners leverage non-federal financial resources to supplement federal grants, saving taxpayer money.more » WIPP complements the Weatherization Assistance program (WAP), which operates nation-wide, in U.S. territories and in three Native American tribes. 16 grantees are implementing weatherization innovation projects using experimental approaches to find new and better ways to weatherize homes. They are using approaches such as: (1) Financial tools - by understanding a diverse range of financing mechanisms, grantees can maximize the impact of the federal grant dollars while providing high-quality work and benefits to eligible low-income clients; (2) Green and healthy homes - in addition to helping families reduce their energy costs, grantees can protect their health and safety. Two WIPP projects (Connecticut and Maryland) will augment standard weatherization services with a comprehensive green and healthy homes approach; (3) New technologies and techniques - following the model of continuous improvement in weatherization, WIPP grantees will continue to use new and better technologies and techniques to improve the quality of work; (4) Residential energy behavior change - Two grantees are rigorously testing home energy monitors (HEMs) that display energy used in kilowatt-hours, allowing residents to monitor and reduce their

  20. CONTINUOUS ROTATION SCATTERING CHAMBER

    DOEpatents

    Verba, J.W.; Hawrylak, R.A.

    1963-08-01

    An evacuated scattering chamber for use in observing nuclear reaction products produced therein over a wide range of scattering angles from an incoming horizontal beam that bombards a target in the chamber is described. A helically moving member that couples the chamber to a detector permits a rapid and broad change of observation angles without breaching the vacuum in the chamber. Also, small inlet and outlet openings are provided whose size remains substantially constant. (auth)

  1. Privacy Policy of NOAA's National Weather Service - NOAA's National Weather

    Science.gov Websites

    Safety Weather Radio Hazard Assmt... StormReady / TsunamiReady Skywarn(tm) Education/Outreach Information , and National Weather Service information collection practices. This Privacy Policy Statement applies only to National Weather Service web sites. Some organizations within NOAA may have other information

  2. Wire chamber

    DOEpatents

    Atac, Muzaffer

    1989-01-01

    A wire chamber or proportional counter device, such as Geiger-Mueller tube or drift chamber, improved with a gas mixture providing a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor.

  3. Combustor with fuel preparation chambers

    NASA Technical Reports Server (NTRS)

    Zelina, Joseph (Inventor); Myers, Geoffrey D. (Inventor); Srinivasan, Ram (Inventor); Reynolds, Robert S. (Inventor)

    2001-01-01

    An annular combustor having fuel preparation chambers mounted in the dome of the combustor. The fuel preparation chamber comprises an annular wall extending axially from an inlet to an exit that defines a mixing chamber. Mounted to the inlet are an air swirler and a fuel atomizer. The air swirler provides swirled air to the mixing chamber while the atomizer provides a fuel spray. On the downstream side of the exit, the fuel preparation chamber has an inwardly extending conical wall that compresses the swirling mixture of fuel and air exiting the mixing chamber.

  4. Filament wound rocket motor chambers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The design, analysis, fabrication and testing of a Kevlar-49/HBRF-55A filament wound chamber is reported. The chamber was fabricated and successfully tested to 80% of the design burst pressure. Results of the data reduction and analysis from the hydrotest indicate that the chamber design and fabrication techniques used for the chamber were adequate and the chamber should perform adequately in a static test.

  5. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  6. Accelerated/abbreviated test methods, study 4 of task 3 (encapsulation) of the low-cost silicon solar array project

    NASA Technical Reports Server (NTRS)

    Kolyer, J. M.; Mann, N. R.

    1978-01-01

    Inherent weatherability is controlled by the three weather factors common to all exposure sites: insolation, temperature, and humidity. Emphasis was focused on the transparent encapsulant portion of miniature solar cell arrays by eliminating weathering effects on the substrate and circuitry (which are also parts of the encapsulant system). The most extensive data were for yellowing, which were measured conveniently and precisely. Considerable data also were obtained on tensile strength. Changes in these two properties after outdoor exposure were predicted very well from accelerated exposure data.

  7. Effect of rutile titania dioxide nanoparticles on the mechanical property, thermal stability, weathering resistance and antibacterial property of styrene acrylic polyurethane coating

    NASA Astrophysics Data System (ADS)

    Vuong Nguyen, Thien; Nguyen, Tuan Anh; Dao, Phi Hung; Phuc Mac, Van; Hiep Nguyen, Anh; Thanh Do, Minh; Nguyen, The Huu

    2016-12-01

    This study aims to enhance the mechanical properties, thermal stability, weathering resistance and antibacterial property of a styrene acrylic polyurethane coating by adding rutile titania dioxide (R-TiO2) nanoparticles in coating formulation. The styrene acrylic polyurethane/R-TiO2 nanocomposite had been prepared by using ultrasonication. The effects of nanoparticles on the mechanical properties, thermal stability and weathering resistance of as-prepared coatings were investigated by using the adhesion strength and ball impact tests, the Fourier transform infrared and UV-vis analyses, thermogravimetric analysis (TGA), and UV/condensation weathering chamber equipped with UVA-340 fluorescent lamps, respectively. The disperse quality of nanoparticles in the coating was examined by using the field emission scanning electron microscope (FESEM). The mechanical test results showed that suitable content of R-TiO2 nanoparticles in the nanocomposite coating was 2 wt%. The FESEM images indicated that the nanoparticles were dispersed homogeneously into the entire volume of the coating. For the nanocomposite prepared by 3 h of ultrasonication, the average size of nanoparticles was in range of 40-50 nm. The ball impact and adhesion tests showed that the incorporation of nanoparticles into the coating significantly enhanced the impact strength from 120 to 145 kg cm and increased the adhesion from level 1 to level 0. The TGA test illustrated that in presence of nanoparticles, the decomposition temperature of coating increased from 146.9 °C to 154.21 °C. For the temperature at 50% loss in mass (T 50%), it was found that the T 50% of the neat coating is 351.86 °C. Adding the 2 wt% R-TiO2 nanoparticles into coating increased the T 50% value to 360.06 °C. After UV/condensation accelerated weathering test (30 cycles), the significant improvement in weight loss, impact strength and adhesion of the neat coating was observed with the presence of nanoparticles. The antibacterial test

  8. Coupling of physical erosion and chemical weathering after phases of intense human activity

    NASA Astrophysics Data System (ADS)

    Schoonejans, Jerome; Vanacker, Veerle; Opfergelt, Sophie; Ameijeiras-Mariño, Yolanda; Kubik, Peter W.

    2014-05-01

    Anthropogenic disturbance of natural vegetation profoundly alters the lateral and vertical fluxes of soil nutrients and particles at the land surface. Human-induced acceleration of soil erosion can thereby result in an imbalance between physical erosion, soil production and chemical weathering. The (de-)coupling between physical erosion and chemical weathering in ecosystems with strong anthropogenic disturbances is not yet fully understood, as earlier studies mostly focused on natural ecosystems. In this study, we explore the chemical weathering intensity for four study sites located in the Internal Zone of the Spanish Betic Cordillera. Most of the sites belong to the Nevado-Filabres complex, but are characterized by different rates of long-term exhumation, 10Be catchment-wide denudation and hill slope morphology. Denudation rates are generally low, but show large variation between the three sites (from 23 to 246 mm kyr-1). The magnitude of denudation rates is consistent with longer-term uplift rates derived from marine deposits, fission-track measurements and vertical fault slip rates. Two to three soil profiles were sampled per study site at exposed ridge tops. All soils overly fractured mica schist, and are very thin (< 60cm). In each soil profile, we sampled 5 depth slices, rock fragments and the (weathered) bedrock. In total, 38 soil and 20 rock samples were analyzed for their chemical composition. The chemical weathering intensity is constrained by the Chemical Depletion Fraction that is based on a chemical mass balance approach using Zr as an immobile element. Chemical weathering accounts for 5 to 35% of the total mass lost due to denudation. We observe systematically higher chemical weathering intensities (CDFs) in sites with lower denudation rates (and vice versa), suggesting that weathering is supply-limited. Our measurements of soil elemental losses from 10 soil profiles suggest that the observed variation in chemical weathering is strongly associated

  9. Dynamic Weather Routes: A Weather Avoidance Concept for Trajectory-Based Operations

    NASA Technical Reports Server (NTRS)

    McNally, B. David; Love, John

    2011-01-01

    The integration of convective weather modeling with trajectory automation for conflict detection, trial planning, direct routing, and auto resolution has uncovered a concept that could help controllers, dispatchers, and pilots identify improved weather routes that result in significant savings in flying time and fuel burn. Trajectory automation continuously and automatically monitors aircraft in flight to find those that could potentially benefit from improved weather reroutes. Controllers, dispatchers, and pilots then evaluate reroute options to assess their suitability given current weather and traffic. In today's operations aircraft fly convective weather avoidance routes that were implemented often hours before aircraft approach the weather and automation does not exist to automatically monitor traffic to find improved weather routes that open up due to changing weather conditions. The automation concept runs in real-time and employs two keysteps. First, a direct routing algorithm automatically identifies flights with large dog legs in their routes and therefore potentially large savings in flying time. These are common - and usually necessary - during convective weather operations and analysis of Fort Worth Center traffic shows many aircraft with short cuts that indicate savings on the order of 10 flying minutes. The second and most critical step is to apply trajectory automation with weather modeling to determine what savings could be achieved by modifying the direct route such that it avoids weather and traffic and is acceptable to controllers and flight crews. Initial analysis of Fort Worth Center traffic suggests a savings of roughly 50% of the direct route savings could be achievable.The core concept is to apply trajectory automation with convective weather modeling in real time to identify a reroute that is free of weather and traffic conflicts and indicates enough time and fuel savings to be considered. The concept is interoperable with today

  10. Magnetic circuit for hall effect plasma accelerator

    NASA Technical Reports Server (NTRS)

    Manzella, David H. (Inventor); Jacobson, David T. (Inventor); Hofer, Richard (Inventor); Peterson, Peter (Inventor); Jankovsky, Robert S. (Inventor)

    2009-01-01

    A Hall effect plasma accelerator includes inner and outer electromagnets, circumferentially surrounding the inner electromagnet along a thruster centerline axis and separated therefrom, inner and outer magnetic conductors, in physical connection with their respective inner and outer electromagnets, with the inner magnetic conductor having a mostly circular shape and the outer magnetic conductor having a mostly annular shape, a discharge chamber, located between the inner and outer magnetic conductors, a magnetically conducting back plate, in magnetic contact with the inner and outer magnetic conductors, and a combined anode electrode/gaseous propellant distributor, located at a bottom portion of the discharge chamber. The inner and outer electromagnets, the inner and outer magnetic conductors and the magnetically conducting back plate form a magnetic circuit that produces a magnetic field that is largely axial and radially symmetric with respect to the thruster centerline.

  11. HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF ...

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

    HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF PLENUM WITH ATTACHED DRAFT REGULATOR. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  12. Iridium-Coated Rhenium Combustion Chamber

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Tuffias, Robert H.; Rosenberg, Sanders D.

    1994-01-01

    Iridium-coated rhenium combustion chamber withstands operating temperatures up to 2,200 degrees C. Chamber designed to replace older silicide-coated combustion chamber in small rocket engine. Modified versions of newer chamber could be designed for use on Earth in gas turbines, ramjets, and scramjets.

  13. Activities in Teaching Weather

    ERIC Educational Resources Information Center

    Tonn, Martin

    1977-01-01

    Presented is a unit composed of activities for teaching weather. Topics include cloud types and formation, simple weather instruments, and the weather station. Illustrations include a weather chart and instruments. A bibliography is given. (MA)

  14. Space Weathering of Rocks

    NASA Technical Reports Server (NTRS)

    Noble, Sarah

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

  15. Automated soil gas monitoring chamber

    DOEpatents

    Edwards, Nelson T.; Riggs, Jeffery S.

    2003-07-29

    A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within the chamber has been invented. The chamber opens between measurements and therefore does not alter the metabolic processes that influence soil gas efflux rates. A multiple chamber system provides for repetitive multi-point sampling, undisturbed metabolic soil processes between sampling, and an essentially airtight sampling chamber operating at ambient pressure.

  16. NOAA's weather forecasts go hyper-local with next-generation weather

    Science.gov Websites

    model NOAA HOME WEATHER OCEANS FISHERIES CHARTING SATELLITES CLIMATE RESEARCH COASTS CAREERS with next-generation weather model New model will help forecasters predict a storm's path, timing and intensity better than ever September 30, 2014 This is a comparison of two weather forecast models looking

  17. Cold-Weather Sports

    MedlinePlus

    ... Videos for Educators Search English Español Cold-Weather Sports KidsHealth / For Teens / Cold-Weather Sports What's in this article? What to Do? Classes ... weather. What better time to be outdoors? Winter sports can help you burn calories, increase your cardiovascular ...

  18. Ion-recombination correction for different ionization chambers in high dose rate flattening-filter-free photon beams

    NASA Astrophysics Data System (ADS)

    Lang, Stephanie; Hrbacek, Jan; Leong, Aidan; Klöck, Stephan

    2012-05-01

    Recently, there has been an increased interest in flattening-filter-free (FFF) linear accelerators. Removal of the filter results in available dose rates up to 24 Gy min-1 (for nominal energy 10 MV in depth of maximum dose, a source-surface distance of 100 cm and a field size of 10×10 cm2). To guarantee accurate relative and reference dosimetry for the FFF beams, we investigated the charge collection efficiency of multiple air-vented and one liquid ionization chamber for dose rates up to 31.9 Gy min-1. For flattened beams, the ion-collection efficiency of all air-vented ionization chambers (except for the PinPoint chamber) was above 0.995. By removing the flattening filter, we found a reduction in collection efficiency of approximately 0.5-0.9% for a 10 MV beam. For FFF beams, the Markus chamber showed the largest collection efficiency of 0.994. The observed collection efficiencies were dependent on dose per pulse, but independent of the pulse repetition frequency. Using the liquid ionization chamber, the ion-collection efficiency for flattened beams was above 0.990 for all dose rates. However, this chamber showed a low collection efficiency of 0.940 for the FFF 10 MV beam at a dose rate of 31.9 Gy min-1. All investigated air-vented ionization chambers can be reliably used for relative dosimetry of FFF beams. The order of correction for reference dosimetry is given in the manuscript. Due to their increased saturation in high dose rate FFF beams, liquid ionization chambers appear to be unsuitable for dosimetry within these contexts.

  19. NASA Weather Support 2017

    NASA Technical Reports Server (NTRS)

    Carroll, Matt

    2017-01-01

    In the mid to late 1980's, as NASA was studying ways to improve weather forecasting capabilities to reduce excessive weather launch delays and to reduce excessive weather Launch Commit Criteria (LCC) waivers, the Challenger Accident occurred and the AC-67 Mishap occurred.[1] NASA and USAF weather personnel had advance knowledge of extremely high levels of weather hazards that ultimately caused or contributed to both of these accidents. In both cases, key knowledge of the risks posed by violations of weather LCC was not in the possession of final decision makers on the launch teams. In addition to convening the mishap boards for these two lost missions, NASA convened expert meteorological boards focusing on weather support. These meteorological boards recommended the development of a dedicated organization with the highest levels of weather expertise and influence to support all of American spaceflight. NASA immediately established the Weather Support Office (WSO) in the Office of Space Flight (OSF), and in coordination with the United Stated Air Force (USAF), initiated an overhaul of the organization and an improvement in technology used for weather support as recommended. Soon after, the USAF established a senior civilian Launch Weather Officer (LWO) position to provide meteorological support and continuity of weather expertise and knowledge over time. The Applied Meteorology Unit (AMU) was established by NASA, USAF, and the National Weather Service to support initiatives to place new tools and methods into an operational status. At the end of the Shuttle Program, after several weather office reorganizations, the WSO function had been assigned to a weather branch at Kennedy Space Center (KSC). This branch was dismantled in steps due to further reorganization, loss of key personnel, and loss of budget line authority. NASA is facing the loss of sufficient expertise and leadership required to provide current levels of weather support. The recommendation proposed

  20. Cockpit weather information needs

    NASA Technical Reports Server (NTRS)

    Scanlon, Charles H.

    1992-01-01

    The primary objective is to develop an advanced pilot weather interface for the flight deck and to measure its utilization and effectiveness in pilot reroute decision processes, weather situation awareness, and weather monitoring. Identical graphical weather displays for the dispatcher, air traffic control (ATC), and pilot crew should also enhance the dialogue capabilities for reroute decisions. By utilizing a broadcast data link for surface observations, forecasts, radar summaries, lightning strikes, and weather alerts, onboard weather computing facilities construct graphical displays, historical weather displays, color textual displays, and other tools to assist the pilot crew. Since the weather data is continually being received and stored by the airborne system, the pilot crew has instantaneous access to the latest information. This information is color coded to distinguish degrees of category for surface observations, ceiling and visibilities, and ground radar summaries. Automatic weather monitoring and pilot crew alerting is accomplished by the airborne computing facilities. When a new weather information is received, the displays are instantaneously changed to reflect the new information. Also, when a new surface or special observation for the intended destination is received, the pilot crew is informed so that information can be studied at the pilot's discretion. The pilot crew is also immediately alerted when a severe weather notice, AIRMET or SIGMET, is received. The cockpit weather display shares a multicolor eight inch cathode ray tube and overlaid touch panel with a pilot crew data link interface. Touch sensitive buttons and areas are used for pilot selection of graphical and data link displays. Time critical ATC messages are presented in a small window that overlays other displays so that immediate pilot alerting and action can be taken. Predeparture and reroute clearances are displayed on the graphical weather system so pilot review of weather along

  1. RADIATION MONITOR CONTAINING TWO CONCENTRIC IONIZATION CHAMBERS AND MEANS FOR INSULATING THE SEPARATE CHAMBERS

    DOEpatents

    Braestrup, C.B.; Mooney, R.T.

    1964-01-21

    This invention relates to a portable radiation monitor containing two concentric ionization chambers which permit the use of standard charging and reading devices. It is particularly adapted as a personnel x-ray dosimeter and to this end comprises a small thin walled, cylindrical conductor forming an inner energy dependent chamber, a small thin walled, cylindrical conductor forming an outer energy independent chamber, and polymeric insulation means which insulates said chambers from each other and holds the chambers together with exposed connections in a simple, trouble-free, and compact assembly substantially without variation in directional response. (AEC)

  2. Employing Numerical Weather Models to Enhance Fire Weather and Fire Behavior Predictions

    Treesearch

    Joseph J. Charney; Lesley A. Fusina

    2006-01-01

    This paper presents an assessment of fire weather and fire behavior predictions produced by a numerical weather prediction model similar to those used by operational weather forecasters when preparing their forecasts. The PSU/NCAR MM5 model is used to simulate the weather conditions associated with three fire episodes in June 2005. Extreme fire behavior was reported...

  3. STUDIES OF A FREE ELECTRON LASER DRIVEN BY A LASER-PLASMA ACCELERATOR

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

    Montgomery, A.; Schroeder, C.; Fawley, W.

    A free electron laser (FEL) uses an undulator, a set of alternating magnets producing a periodic magnetic fi eld, to stimulate emission of coherent radiation from a relativistic electron beam. The Lasers, Optical Accelerator Systems Integrated Studies (LOASIS) group at Lawrence Berkeley National Laboratory (LBNL) will use an innovative laserplasma wakefi eld accelerator to produce an electron beam to drive a proposed FEL. In order to optimize the FEL performance, the dependence on electron beam and undulator parameters must be understood. Numerical modeling of the FEL using the simulation code GINGER predicts the experimental results for given input parameters. Amongmore » the parameters studied were electron beam energy spread, emittance, and mismatch with the undulator focusing. Vacuum-chamber wakefi elds were also simulated to study their effect on FEL performance. Energy spread was found to be the most infl uential factor, with output FEL radiation power sharply decreasing for relative energy spreads greater than 0.33%. Vacuum chamber wakefi elds and beam mismatch had little effect on the simulated LOASIS FEL at the currents considered. This study concludes that continued improvement of the laser-plasma wakefi eld accelerator electron beam will allow the LOASIS FEL to operate in an optimal regime, producing high-quality XUV and x-ray pulses.« less

  4. Sensitivity of 30-cm mercury bombardment ion thruster characteristics to accelerator grid design

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1978-01-01

    The design of ion optics for bombardment thrusters strongly influences overall performance and lifetime. The operation of a 30 cm thruster with accelerator grid open area fractions ranging from 43 to 24 percent, was evaluated and compared with experimental and theoretical results. Ion optics properties measured included the beam current extraction capability, the minimum accelerator grid voltage to prevent backstreaming, ion beamlet diameter as a function of radial position on the grid and accelerator grid hole diameter, and the high energy, high angle ion beam edge location. Discharge chamber properties evaluated were propellant utilization efficiency, minimum discharge power per beam amp, and minimum discharge voltage.

  5. Vibrating-chamber levitation systems

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Granett, D.; Lee, M. C. (Inventor)

    1985-01-01

    Systems are described for the acoustic levitation of objects, which enable the use of a sealed rigid chamber to avoid contamination of the levitated object. The apparatus includes a housing forming a substantially closed chamber, and means for vibrating the entire housing at a frequency that produces an acoustic standing wave pattern within the chamber.

  6. Seedling-Size Fumigation Chambers

    Treesearch

    Keith F. Jensen; Frederick W. Bender

    1977-01-01

    The design of fumigation chambers is described. Each chamber has individual temperature, humidity, light, and pollutant control. Temperature is variable from 15 to 35ºC and controlled within ± 1ºC. Humidity is variable from 25 to 95 percent and controlled within ± 3 percent. Seedlings have been successfully grown in these chambers...

  7. Mercury ion thruster research, 1977. [plasma acceleration

    NASA Technical Reports Server (NTRS)

    Wilbur, P. J.

    1977-01-01

    The measured ion beam divergence characteristics of two and three-grid, multiaperture accelerator systems are presented. The effects of perveance, geometry, net-to-total accelerating voltage, discharge voltage and propellant are examined. The applicability of a model describing doubly-charged ion densities in mercury thrusters is demonstrated for an 8-cm diameter thruster. The results of detailed Langmuir probing of the interior of an operating cathode are given and used to determine the ionization fraction as a function of position upstream of the cathode orifice. A mathematical model of discharge chamber electron diffusion and collection processes is presented along with scaling laws useful in estimating performance of large diameter and/or high specific impluse thrusters. A model describing the production of ionized molecular nitrogen in ion thrusters is included.

  8. Sleeve reaction chamber system

    DOEpatents

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  9. Highlights of Space Weather Services/Capabilities at NASA/GSFC Space Weather Center

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Zheng, Yihua; Hesse, Michael; Kuznetsova, Maria; Pulkkinen, Antti; Taktakishvili, Aleksandre; Mays, Leila; Chulaki, Anna; Lee, Hyesook

    2012-01-01

    The importance of space weather has been recognized world-wide. Our society depends increasingly on technological infrastructure, including the power grid as well as satellites used for communication and navigation. Such technologies, however, are vulnerable to space weather effects caused by the Sun's variability. NASA GSFC's Space Weather Center (SWC) (http://science.gsfc.nasa.gov//674/swx services/swx services.html) has developed space weather products/capabilities/services that not only respond to NASA's needs but also address broader interests by leveraging the latest scientific research results and state-of-the-art models hosted at the Community Coordinated Modeling Center (CCMC: http://ccmc.gsfc.nasa.gov). By combining forefront space weather science and models, employing an innovative and configurable dissemination system (iSWA.gsfc.nasa.gov), taking advantage of scientific expertise both in-house and from the broader community as well as fostering and actively participating in multilateral collaborations both nationally and internationally, NASA/GSFC space weather Center, as a sibling organization to CCMC, is poised to address NASA's space weather needs (and needs of various partners) and to help enhancing space weather forecasting capabilities collaboratively. With a large number of state-of-the-art physics-based models running in real-time covering the whole space weather domain, it offers predictive capabilities and a comprehensive view of space weather events throughout the solar system. In this paper, we will provide some highlights of our service products/capabilities. In particular, we will take the 23 January and the 27 January space weather events as examples to illustrate how we can use the iSWA system to track them in the interplanetary space and forecast their impacts.

  10. Cyclic fatigue analysis of rocket thrust chambers. Volume 1: OFHC copper chamber low cycle fatigue

    NASA Technical Reports Server (NTRS)

    Miller, R. W.

    1974-01-01

    A three-dimensional finite element elasto-plastic strain analysis was performed for the throat section of a regeneratively cooled rocket combustion chamber. The analysis employed the RETSCP finite element computer program. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the chamber operating cycle. The analysis was performed for chamber configuration and operating conditions corresponding to a hydrogen-oxygen combustion chamber which was fatigue tested to failure. The computed strain range at typical chamber operating conditions was used in conjunction with oxygen-free, high-conductivity (OHFC) copper isothermal fatigue test data to predict chamber low-cycle fatigue life.

  11. Weather Education/Outreach - NOAA's National Weather Service

    Science.gov Websites

    select the go button to submit request City, St Go Sign-up for Email Alerts RSS Feeds RSS Feeds Warnings Skip Navigation Links weather.gov NOAA logo-Select to go to the NOAA homepage National Oceanic and Atmospheric Administration's Select to go to the NWS homepage National Weather Service Site Map News

  12. Careers in Weather - NOAA's National Weather Service

    Science.gov Websites

    select the go button to submit request City, St Go Sign-up for Email Alerts RSS Feeds RSS Feeds Warnings Skip Navigation Links weather.gov NOAA logo-Select to go to the NOAA homepage National Oceanic and Atmospheric Administration's Select to go to the NWS homepage National Weather Service Site Map News

  13. American Weather Stories.

    ERIC Educational Resources Information Center

    Hughes, Patrick

    Weather has shaped United States' culture, national character and folklore; at times it has changed the course of history. The seven accounts compiled in this publication highlight some of the nation's weather experiences from the hurricanes that threatened Christopher Columbus to the peculiar run of bad weather that has plagued American…

  14. NASA Space Weather Center Services: Potential for Space Weather Research

    NASA Technical Reports Server (NTRS)

    Zheng, Yihua; Kuznetsova, Masha; Pulkkinen, Antti; Taktakishvili, A.; Mays, M. L.; Chulaki, A.; Lee, H.; Hesse, M.

    2012-01-01

    The NASA Space Weather Center's primary objective is to provide the latest space weather information and forecasting for NASA's robotic missions and its partners and to bring space weather knowledge to the public. At the same time, the tools and services it possesses can be invaluable for research purposes. Here we show how our archive and real-time modeling of space weather events can aid research in a variety of ways, with different classification criteria. We will list and discuss major CME events, major geomagnetic storms, and major SEP events that occurred during the years 2010 - 2012. Highlights of major tools/resources will be provided.

  15. Weathering and weathering rates of natural stone

    NASA Astrophysics Data System (ADS)

    Winkler, Erhard M.

    1987-06-01

    Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the rocks' permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of the causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between disolution, crack-corrosion, and expansion-contraction cycies triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

  16. Tubular copper thrust chamber design study

    NASA Technical Reports Server (NTRS)

    Masters, A. I.; Galler, D. E.

    1992-01-01

    The use of copper tubular thrust chambers is particularly important in high performance expander cycle space engines. Tubular chambers have more surface area than flat wall chambers, and this extra surface area provides enhanced heat transfer for additional energy to power the cycle. This paper was divided into two sections: (1) a thermal analysis and sensitivity study; and (2) a preliminary design of a selected thrust chamber configuration. The thermal analysis consisted of a statistical optimization to determine the optimum tube geometry, tube booking, thrust chamber geometry, and cooling routing to achieve the maximum upper limit chamber pressure for a 25,000 pound thrust engine. The preliminary design effort produced a layout drawing of a tubular thrust chamber that is three inches shorter than the Advanced Expander Test Bed (AETB) milled channel chamber but is predicted to provide a five percent increase in heat transfer. Testing this chamber in the AETB would confirm the inherent advantages of tubular chamber construction and heat transfer.

  17. Aviation weather : FAA and the National Weather Service are considering plans to consolidate weather service offices, but face significant challenges.

    DOT National Transportation Integrated Search

    2009-07-01

    The National Weather Services (NWS) weather products are a vital component of the Federal Aviation Administrations (FAA) air traffic control system. In addition to providing aviation weather products developed at its own facilities, NWS also pr...

  18. Comparing Novel Multi-Gap Resistive Plate Chamber Models

    NASA Astrophysics Data System (ADS)

    Stien, Haley; EIC PID Consortium Collaboration

    2016-09-01

    Investigating nuclear structure has led to the fundamental theory of Quantum Chromodynamics. An Electron Ion Collider (EIC) is a proposed accelerator that would further these investigations. In order to prepare for the EIC, there is an active detector research and development effort. One specific goal is to achieve better particle identification via improved Time of Flight (TOF) detectors. A promising option is the Multi-Gap Resistive Plate Chamber (mRPC). These detectors are similar to the more traditional RPCs, but their active gas gaps have dividers to form several thinner gas gaps. These very thin and accurately defined gas gaps improve the timing resolution of the chamber, so the goal is to build an mRPC with the thinnest gaps to achieve the best possible timing resolution. Two different construction techniques have been employed to make two mRPCs. The first technique is to physically separate the gas gaps with sheets of glass that are .2mm thick. The second technique is to 3D print the layered gas gaps. A comparison of these mRPCs and their performances will be discussed and the latest data presented. This research was supported by US DOE MENP Grant DE-FG02-03ER41243.

  19. Cancellation of residual spacecraft accelerations for zero-G space physics experiments

    NASA Technical Reports Server (NTRS)

    Stephens, J. B.

    1977-01-01

    The Drop Dynamics Module houses an acoustic positioning system which counteracts the effects of small accelerations of a spacecraft and thus allows long-term study of free-floating materials such as liquid drops. The acoustic positioning system provides an acoustic 'well' in the center of the experiment chamber. Data collection is by cinematographic photography. The module subsystems are discussed.

  20. Wall-ablative laser-driven in-tube accelerator

    NASA Astrophysics Data System (ADS)

    Sasoh, Akihiro; Suzuki, Shingo; Matsuda, Atsushi

    2008-05-01

    The laser-driven in-tube accelerator in which the propellant is supplied from laser-ablated gas from the tube wall was developed. Proof-of concept demonstrations of vertical launch were successfully done. The device had a 25mm X 25mm square cross-section; two opposing walls were made of polyacetal and acted as the propellant, the other two acrylic window with guide grooves to the projectile. The upper end of the launch tube was connected to a vacuum chamber of an inner volume of 0.8 m2, in which the initial pressure was set to lower than 20 Pa. With plugging the bottom end of the launch tube, a momentum coupling coefficient exceeding 2.5 mN/W was obtained. Even with the bottom end connected to the same vacuum chamber through a different duct, the projectile was vertical launched successfully, obtaining 0.14 mN/W.

  1. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. 77.305 Section 77.305 Mineral Resources MINE SAFETY... drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot...

  2. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. 77.305 Section 77.305 Mineral Resources MINE SAFETY... drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot...

  3. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. 77.305 Section 77.305 Mineral Resources MINE SAFETY... drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot...

  4. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. 77.305 Section 77.305 Mineral Resources MINE SAFETY... drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot...

  5. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. 77.305 Section 77.305 Mineral Resources MINE SAFETY... drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot...

  6. Effect of accelerated environmental aging on tensile properties of oil palm/jute hybrid composites

    NASA Astrophysics Data System (ADS)

    Jawaid, M.; Saba, N.; Alothman, O.; Paridah, M. T.

    2016-11-01

    Recently natural fibre based hybrid composites are receiving growing consideration due to environmental and biodegradability properties. In order to look behaviour of hybrid composites in outdoor applications, its environmental degradation properties such as UV accelerated weathering properties need to analyze. In this study oil palm empty fruit bunch (EFB) and jute fibres reinforced hybrid composites, pure EFB, pure jute and epoxy composites were fabricated through hand lay-up techniques. Hybrid composites with different layering pattern (EFB/jute/EFB and Jute/EFB/jute) while maintaining 40 wt. % total fibre loading were fabricates to compared with EFB and jute composites. Effect of UV accelerated environmental aging on tensile properties of epoxy, pure EFB, pure jute, and hybrid composites were assessed and evaluate under UV exposure. Tensile samples of all composites were subjected to accelerated weathering for 100h, at temperature (75°C), relative humidity (35%), Light (125 W/m2), and water spray off. Obtained results indicated that there is reduction in tensile strength, modulus and elongation at break values of hybrid and pure composites due to degradation of lignin and fibre-matrix interfacial bonding.

  7. Socio-Economic Impacts of Space Weather and User Needs for Space Weather Information

    NASA Astrophysics Data System (ADS)

    Worman, S. L.; Taylor, S. M.; Onsager, T. G.; Adkins, J. E.; Baker, D. N.; Forbes, K. F.

    2017-12-01

    The 2015 National Space Weather Strategy and Space Weather Action Plan (SWAP) details the activities, outcomes, and timelines to build a "Space Weather Ready Nation." NOAA's Space Weather Prediction Center and Abt Associates are working together on two SWAP initiatives: (1) identifying, describing, and quantifying the socio-economic impacts of moderate and severe space weather; and (2) outreach to engineers and operators to better understand user requirements for space weather products and services. Both studies cover four technological sectors (electric power, commercial aviation, satellites, and GNSS users) and rely heavily on industry input. Findings from both studies are essential for decreasing vulnerabilities and enhancing preparedness.

  8. Weathering of wood

    Treesearch

    R. Sam Williams

    2005-01-01

    Weathering is the general term used to define the slow degradation of materials exposed to the weather. The degradation mechanism depends on the type of material, but the cause is a combination of factors found in nature: moisture, sunlight, heat/cold, chemicals, abrasion by windblown materials, and biological agents. Tall mountains weather by the complex and...

  9. Mechanical weathering and rock erosion by climate-dependent subcritical cracking

    NASA Astrophysics Data System (ADS)

    Eppes, Martha-Cary; Keanini, Russell

    2017-06-01

    This work constructs a fracture mechanics framework for conceptualizing mechanical rock breakdown and consequent regolith production and erosion on the surface of Earth and other terrestrial bodies. Here our analysis of fracture mechanics literature explicitly establishes for the first time that all mechanical weathering in most rock types likely progresses by climate-dependent subcritical cracking under virtually all Earth surface and near-surface environmental conditions. We substantiate and quantify this finding through development of physically based subcritical cracking and rock erosion models founded in well-vetted fracture mechanics and mechanical weathering, theory, and observation. The models show that subcritical cracking can culminate in significant rock fracture and erosion under commonly experienced environmental stress magnitudes that are significantly lower than rock critical strength. Our calculations also indicate that climate strongly influences subcritical cracking—and thus rock weathering rates—irrespective of the source of the stress (e.g., freezing, thermal cycling, and unloading). The climate dependence of subcritical cracking rates is due to the chemophysical processes acting to break bonds at crack tips experiencing these low stresses. We find that for any stress or combination of stresses lower than a rock's critical strength, linear increases in humidity lead to exponential acceleration of subcritical cracking and associated rock erosion. Our modeling also shows that these rates are sensitive to numerous other environment, rock, and mineral properties that are currently not well characterized. We propose that confining pressure from overlying soil or rock may serve to suppress subcritical cracking in near-surface environments. These results are applicable to all weathering processes.

  10. Space Weather

    NASA Astrophysics Data System (ADS)

    Hapgood, Mike

    2017-01-01

    Space weather-changes in the Earth's environment that can often be traced to physical processes in the Sun-can have a profound impact on critical Earth-based infrastructures such as power grids and civil aviation. Violent eruptions on the solar surface can eject huge clouds of magnetized plasma and particle radiation, which then propagate across interplanetary space and envelop the Earth. These space weather events can drive major changes in a variety of terrestrial environments, which can disrupt, or even damage, many of the technological systems that underpin modern societies. The aim of this book is to offer an insight into our current scientific understanding of space weather, and how we can use that knowledge to mitigate the risks it poses for Earth-based technologies. It also identifies some key challenges for future space-weather research, and considers how emerging technological developments may introduce new risks that will drive continuing investigation.

  11. Weather in Your Life.

    ERIC Educational Resources Information Center

    Kannegieter, Sandy; Wirkler, Linda

    Facts and activities related to weather and meteorology are presented in this unit. Separate sections cover the following topics: (1) the water cycle; (2) clouds; (3) the Beaufort Scale for rating the speed and force of wind; (4) the barometer; (5) weather prediction; (6) fall weather in Iowa (sleet, frost, and fog); (7) winter weather in Iowa…

  12. Weather it's Climate Change?

    NASA Astrophysics Data System (ADS)

    Bostrom, A.; Lashof, D.

    2004-12-01

    For almost two decades both national polls and in-depth studies of global warming perceptions have shown that people commonly conflate weather and global climate change. Not only are current weather events such as anecdotal heat waves, droughts or cold spells treated as evidence for or against global warming, but weather changes such as warmer weather and increased storm intensity and frequency are the consequences most likely to come to mind. Distinguishing weather from climate remains a challenge for many. This weather 'framing' of global warming may inhibit behavioral and policy change in several ways. Weather is understood as natural, on an immense scale that makes controlling it difficult to conceive. Further, these attributes contribute to perceptions that global warming, like weather, is uncontrollable. This talk presents an analysis of data from public opinion polls, focus groups, and cognitive studies regarding people's mental models of and 'frames' for global warming and climate change, and the role weather plays in these. This research suggests that priming people with a model of global warming as being caused by a "thickening blanket of carbon dioxide" that "traps heat" in the atmosphere solves some of these communications problems and makes it more likely that people will support policies to address global warming.

  13. Design, fabrication, and operation of dished accelerator grids on a 30-cm ion thruster

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Banks, B. A.; Byers, D. C.

    1972-01-01

    Several closely-space dished accelerator grid systems were fabricated and tested on a 30-cm diameter mercury bombardment thruster and they appear to be a solution to the stringent requirements imposed by the near-term, high-thrust, low specific impulse electric propulsion missions. The grids were simultaneously hydroformed and then simultaneously stress relieved. The ion extraction capability and discharge chamber performance were studied as the total accelerating voltage, the ratio of net-to-total voltage, grid spacing, and dish direction were varied.

  14. Topographic imprint on chemical weathering in deeply weathered soil-mantled landscapes (southern Brazil)

    NASA Astrophysics Data System (ADS)

    Vanacker, Veerle; Schoonejans, Jerome; Ameijeiras-Marino, Yolanda; Opfergelt, Sophie; Minella, Jean

    2017-04-01

    The regolith mantle is defined as the thin layer of unconsolidated material overlaying bedrock that contributes to shape the Earth's surface. The development of the regolith mantle in a landscape is the result of in-situ weathering, atmospheric input and downhill transport of weathering products. Bedrock weathering - the physical and chemical transformations of rock to soil - contributes to the vertical development of the regolith layer through downward propagation of the weathering front. Lateral transport of soil particles, aggregates and solutes by diffusive and concentrated particle and solute fluxes result in lateral redistribution of weathering products over the hillslope. In this study, we aim to expand the empirical basis on long-term soil evolution at the landscape scale through a detailed study of soil weathering in subtropical soils. Spatial variability in chemical mass fluxes and weathering intensity were studied along two toposequences with similar climate, lithology and vegetation but different slope morphology. This allowed us to isolate the topographic imprint on chemical weathering and soil development. The toposequences have convexo-concave slope morphology, and eight regolith profiles were analysed involving the flat upslope, steep midslope and flat toeslope part. Our data show a clear topographic imprint on soil development. Along hillslope, the chemical weathering intensity of the regolith profiles increases with distance from the crest. In contrast to the upslope positions, the soils in the basal concavities develop on in-situ and transported regolith. While the chemical weathering extent on the slope convexities (the upslope profiles) is similar for the steep and gentle toposequence, there is a clear difference in the rate of increase of the chemical weathering extent with distance from the crest. The increase of chemical weathering extent along hillslope is highest for the steep toposequence, suggesting that topography enhances soil particle

  15. A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

    NASA Astrophysics Data System (ADS)

    Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

    2015-11-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

  16. A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

    NASA Astrophysics Data System (ADS)

    Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

    2016-03-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

  17. Pyrite oxidation under simulated acid rain weathering conditions.

    PubMed

    Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

    2017-09-01

    We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

  18. Sensitivity of barley varieties to weather in Finland.

    PubMed

    Hakala, K; Jauhiainen, L; Himanen, S J; Rötter, R; Salo, T; Kahiluoto, H

    2012-04-01

    Global climate change is predicted to shift seasonal temperature and precipitation patterns. An increasing frequency of extreme weather events such as heat waves and prolonged droughts is predicted, but there are high levels of uncertainty about the nature of local changes. Crop adaptation will be important in reducing potential damage to agriculture. Crop diversity may enhance resilience to climate variability and changes that are difficult to predict. Therefore, there has to be sufficient diversity within the set of available cultivars in response to weather parameters critical for yield formation. To determine the scale of such 'weather response diversity' within barley (Hordeum vulgare L.), an important crop in northern conditions, the yield responses of a wide range of modern and historical varieties were analysed according to a well-defined set of critical agro-meteorological variables. The Finnish long-term dataset of MTT Official Variety Trials was used together with historical weather records of the Finnish Meteorological Institute. The foci of the analysis were firstly to describe the general response of barley to different weather conditions and secondly to reveal the diversity among varieties in the sensitivity to each weather variable. It was established that barley yields were frequently reduced by drought or excessive rain early in the season, by high temperatures at around heading, and by accelerated temperature sum accumulation rates during periods 2 weeks before heading and between heading and yellow ripeness. Low temperatures early in the season increased yields, but frost during the first 4 weeks after sowing had no effect. After canopy establishment, higher precipitation on average resulted in higher yields. In a cultivar-specific analysis, it was found that there were differences in responses to all but three of the studied climatic variables: waterlogging and drought early in the season and temperature sum accumulation rate before heading

  19. Dependence with air density of the response of the PTW SourceCheck ionization chamber for low energy brachytherapy sources.

    PubMed

    Tornero-López, Ana M; Guirado, Damián; Perez-Calatayud, Jose; Ruiz-Arrebola, Samuel; Simancas, Fernando; Gazdic-Santic, Maja; Lallena, Antonio M

    2013-12-01

    Air-communicating well ionization chambers are commonly used to assess air kerma strength of sources used in brachytherapy. The signal produced is supposed to be proportional to the air density within the chamber and, therefore, a density-independent air kerma strength is obtained when the measurement is corrected to standard atmospheric conditions using the usual temperature and pressure correction factor. Nevertheless, when assessing low energy sources, the ionization chambers may not fulfill that condition and a residual density dependence still remains after correction. In this work, the authors examined the behavior of the PTW 34051 SourceCheck ionization chamber when measuring the air kerma strength of (125)I seeds. Four different SourceCheck chambers were analyzed. With each one of them, two series of measurements of the air kerma strength for (125)I selectSeed(TM) brachytherapy sources were performed inside a pressure chamber and varying the pressure in a range from 747 to 1040 hPa (560 to 780 mm Hg). The temperature and relative humidity were kept basically constant. An analogous experiment was performed by taking measurements at different altitudes above sea level. Contrary to other well-known ionization chambers, like the HDR1000 PLUS, in which the temperature-pressure correction factor overcorrects the measurements, in the SourceCheck ionization chamber they are undercorrected. At a typical atmospheric situation of 933 hPa (700 mm Hg) and 20 °C, this undercorrection turns out to be 1.5%. Corrected measurements show a residual linear dependence on the density and, as a consequence, an additional density dependent correction must be applied. The slope of this residual linear density dependence is different for each SourceCheck chamber investigated. The results obtained by taking measurements at different altitudes are compatible with those obtained with the pressure chamber. Variations of the altitude and changes in the weather conditions may produce

  20. Weather Features Associated with Aircraft Icing Conditions: A Case Study

    PubMed Central

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk. PMID:24701152

  1. Weather features associated with aircraft icing conditions: a case study.

    PubMed

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk.

  2. Rocket thrust chamber thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Quentmeyer, R. J.

    1985-01-01

    Subscale rocket thrust chamber tests were conducted to evaluate the effectiveness and durability of thin yttria stabilized zirconium oxide coatings applied to the thrust chamber hot-gas side wall. The fabrication consisted of arc plasma spraying the ceramic coating and bond coat onto a mandrell and then electrodepositing the copper thrust chamber wall around the coating. Chambers were fabricated with coatings .008, and .005 and .003 inches thick. The chambers were thermally cycled at a chamber pressure of 600 psia using oxygen-hydrogen as propellants and liquid hydrogen as the coolant. The thicker coatings tended to delaminate, early in the cyclic testing, down to a uniform sublayer which remained well adhered during the remaining cycles. Two chambers with .003 inch coatings were subjected to 1500 thermal cycles with no coating loss in the throat region, which represents a tenfold increase in life over identical chambers having no coatings. An analysis is presented which shows that the heat lost to the coolant due to the coating, in a rocket thrust chamber design having a coating only in the throat region, can be recovered by adding only one inch to the combustion chamber length.

  3. Weather and emotional state

    NASA Astrophysics Data System (ADS)

    Spasova, Z.

    2010-09-01

    Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions

  4. Aviation weather services

    NASA Technical Reports Server (NTRS)

    Sprinkle, C. H.

    1983-01-01

    The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.

  5. Weather Instruments.

    ERIC Educational Resources Information Center

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities to measure various weather phenomena. Directions for constructing a weather station are included. Instruments including rain gauges, thermometers, wind vanes, wind speed devices, humidity devices, barometers, atmospheric observations, a dustfall jar, sticky-tape can, detection of gases in the air, and pH of…

  6. A Milestone in Commercial Space Weather: USTAR Center for Space Weather

    NASA Astrophysics Data System (ADS)

    Tobiska, W.; Schunk, R. W.; Sojka, J. J.; Thompson, D. C.; Scherliess, L.; Zhu, L.; Gardner, L. C.

    2009-12-01

    As of 2009, Utah State University (USU) hosts a new organization to develop commercial space weather applications using funding that has been provided by the State of Utah’s Utah Science Technology and Research (USTAR) initiative. The USTAR Center for Space Weather (UCSW) is located on the USU campus in Logan, Utah and is developing innovative applications for mitigating adverse space weather effects in technological systems. Space weather’s effects upon the near-Earth environment are due to dynamic changes in the Sun’s photons, particles, and fields. Of the space environment domains that are affected by space weather, the ionosphere is the key region that affects communication and navigation systems. The UCSW has developed products for users of systems that are affected by space weather-driven ionospheric changes. For example, on September 1, 2009 USCW released, in conjunction with Space Environment Technologies, the world’s first real-time space weather via an iPhone app. Space WX displays the real-time, current global ionosphere total electron content along with its space weather drivers; it is available through the Apple iTunes store and is used around the planet. The Global Assimilation of Ionospheric Measurements (GAIM) system is now being run operationally in real-time at UCSW with the continuous ingestion of hundreds of global data streams to dramatically improve the ionosphere’s characterization. We discuss not only funding and technical advances that have led to current products but also describe the direction for UCSW that includes partnering opportunities for moving commercial space weather into fully automated specification and forecasting over the next half decade.

  7. Optimizing Placement of Weather Stations: Exploring Objective Functions of Meaningful Combinations of Multiple Weather Variables

    NASA Astrophysics Data System (ADS)

    Snyder, A.; Dietterich, T.; Selker, J. S.

    2017-12-01

    Many regions of the world lack ground-based weather data due to inadequate or unreliable weather station networks. For example, most countries in Sub-Saharan Africa have unreliable, sparse networks of weather stations. The absence of these data can have consequences on weather forecasting, prediction of severe weather events, agricultural planning, and climate change monitoring. The Trans-African Hydro-Meteorological Observatory (TAHMO.org) project seeks to address these problems by deploying and operating a large network of weather stations throughout Sub-Saharan Africa. To design the TAHMO network, we must determine where to place weather stations within each country. We should consider how we can create accurate spatio-temporal maps of weather data and how to balance the desired accuracy of each weather variable of interest (precipitation, temperature, relative humidity, etc.). We can express this problem as a joint optimization of multiple weather variables, given a fixed number of weather stations. We use reanalysis data as the best representation of the "true" weather patterns that occur in the region of interest. For each possible combination of sites, we interpolate the reanalysis data between selected locations and calculate the mean average error between the reanalysis ("true") data and the interpolated data. In order to formulate our multi-variate optimization problem, we explore different methods of weighting each weather variable in our objective function. These methods include systematic variation of weights to determine which weather variables have the strongest influence on the network design, as well as combinations targeted for specific purposes. For example, we can use computed evapotranspiration as a metric that combines many weather variables in a way that is meaningful for agricultural and hydrological applications. We compare the errors of the weather station networks produced by each optimization problem formulation. We also compare these

  8. Synoptic weather types associated with critical fire weather

    Treesearch

    Mark J. Schroeder; Monte Glovinsky; Virgil F. Hendricks; Frank C. Hood; Melvin K. Hull; Henry L. Jacobson; Robert Kirkpatrick; Daniel W. Krueger; Lester P. Mallory; Albert G. Oeztel; Robert H. Reese; Leo A. Sergius; Charles E. Syverson

    1964-01-01

    Recognizing that weather is an important factor in the spread of both urban and wildland fires, a study was made of the synoptic weather patterns and types which produce strong winds, low relative humidities, high temperatures, and lack of rainfall--the conditions conducive to rapid fire spread. Such historic fires as the San Francisco fire of 1906, the Berkeley fire...

  9. New weather index

    NASA Astrophysics Data System (ADS)

    Scientists at the National Oceanic and Atmospheric Administration (NOAA) and the University of Delaware have refined the wind-chill factor, a common measurement of weather discomfort, into a new misery register called the weather stress index. In addition to the mix of temperature and wind speed data used to calculate wind chill, the recipe for the index adds two new ingredients—humidity and a dash of benchmark statistics—to estimate human reaction to weather conditions. NOAA says that the weather stress index estimates human reaction to weather conditions and that the reaction depends on variations from the ‘normal’ conditions in the locality involved.Discomfort criteria for New Orleans, La., and Bismarck, N.D., for example, differ drastically. According to NOAA, when it's the middle of winter and it's -10°C with a relative humidity of 80% and 24 km/h winds, persons in New Orleans would be highly stressed while those in Bismarck wouldn't bat an eye.

  10. Chemical weathering indices applied to weathering profiles developed on heterogeneous felsic metamorphic parent rocks

    Treesearch

    Jason R. Price; Michael A. Velbel

    2003-01-01

    Chemical weathering indices are commonly used for characterizing weathering profiles by incorporating bulk major element oxide chemistry into a single metric for each sample. Generally, on homogeneous parent rocks, weathering indices change systematically with depth. However, the weathering of heterogeneous metamorphic rocks confounds the relationship between...

  11. The Planeterrella: an Analog Model for Teaching About the Invisible Electromagnetic Processes Driving Space Weather

    NASA Astrophysics Data System (ADS)

    Masongsong, E. V.; Glesener, G. B.; Angelopoulos, V.; Lilensten, J.; Bingley, L.

    2015-12-01

    The Planeterrella can be used as an analog to help students visualize and understand the electromagnetic processes driving space weather that affect our daily lives. Solar storms and solar wind charged particles (plasma) cause "space weather" via their interaction with Earth's protective magnetic shield, the magnetosphere. The Planeterrella uses magnetized spheres in a vacuum chamber to demonstrate solar wind energy transfer to Earth and planets, with polar localization of aurora due to charged particles traveling along geomagnetic field lines. The Planeterrella provides a unique opportunity to experience and manipulate plasma, the dominant form of matter in our universe, yet seldom observable on Earth. Severe space weather events produce spectacular auroral displays as well as devastating consequences: radiation exposure to air and space travelers, prolonged radio blackouts, and damage to critical GPS and communications satellites. We will (1) discuss ways in which the Planeterrella may be most useful in classroom settings, including large lecture halls, laboratories, and small discussion sessions; (2) provide information on how instructors can produce their own Planeterrella for their courses; and (3) invite meeting attendees to engage in a discussion on how we might be able to improve on the current design of the Planeterrella, and how to reach students in more parts of the world.

  12. Formation of halloysite from feldspar: Low temperature, artificial weathering versus natural weathering

    USGS Publications Warehouse

    Parham, Walter E.

    1969-01-01

    Weathering products formed on surfaces of both potassium and plagioclase feldspar (An70), which were continuously leached in a Soxhlet extraction apparatus for 140 days with 7.21 of distilled water per day at a temperature of approximately 78°C, are morphologically identical to natural products developed on potassium feldspars weathered under conditions of good drainage in the humid tropics. The new products, which first appear as tiny bumps on the feldspar surface, start to develop mainly at exposed edges but also at apparently random sites on flat cleavage surfaces. As weathering continues, the bumps grow outward from the feldspar surface to form tapered projections, which then develop into wide-based thin films or sheets. The thin sheets of many projections merge laterally to form one continuous flame-shaped sheet. The sheets formed on potassium feldspars may then roll to form tubes that are inclined at a high angle to the feldspar surface. Etch pits of triangular outline on the artificially weathered potassium feldspars serve as sites for development of continuous, non-rolled, hollow tubes. It is inferred from its morphology that this weathering product is halloysite or its primitive form. The product of naturally weathered potassium feldspars is halloysite . 4H2O.The flame-shaped films or sheets formed on artificially weathered plagioclase feldspar do not develop into hollow tubes, but instead give rise to a platy mineral that is most probably boehmite. These plates form within the flame-shaped films, and with continued weathering are released as the film deteriorates. There is no indication from this experiment that platy pseudohexagonal kaolinite forms from any of these minerals under the initial stage of weathering.

  13. Weather Information Processing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Science Communications International (SCI), formerly General Science Corporation, has developed several commercial products based upon experience acquired as a NASA Contractor. Among them are METPRO, a meteorological data acquisition and processing system, which has been widely used, RISKPRO, an environmental assessment system, and MAPPRO, a geographic information system. METPRO software is used to collect weather data from satellites, ground-based observation systems and radio weather broadcasts to generate weather maps, enabling potential disaster areas to receive advance warning. GSC's initial work for NASA Goddard Space Flight Center resulted in METPAK, a weather satellite data analysis system. METPAK led to the commercial METPRO system. The company also provides data to other government agencies, U.S. embassies and foreign countries.

  14. Road Weather and Connected Vehicles

    NASA Astrophysics Data System (ADS)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  15. Wacky Weather

    ERIC Educational Resources Information Center

    Sabarre, Amy; Gulino, Jacqueline

    2013-01-01

    What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

  16. Improved Rhenium Thrust Chambers

    NASA Technical Reports Server (NTRS)

    O'Dell, John Scott

    2015-01-01

    Radiation-cooled bipropellant thrust chambers are being considered for ascent/ descent engines and reaction control systems on various NASA missions and spacecraft, such as the Mars Sample Return and Orion Multi-Purpose Crew Vehicle (MPCV). Currently, iridium (Ir)-lined rhenium (Re) combustion chambers are the state of the art for in-space engines. NASA's Advanced Materials Bipropellant Rocket (AMBR) engine, a 150-lbf Ir-Re chamber produced by Plasma Processes and Aerojet Rocketdyne, recently set a hydrazine specific impulse record of 333.5 seconds. To withstand the high loads during terrestrial launch, Re chambers with improved mechanical properties are needed. Recent electrochemical forming (EL-Form"TM") results have shown considerable promise for improving Re's mechanical properties by producing a multilayered deposit composed of a tailored microstructure (i.e., Engineered Re). The Engineered Re processing techniques were optimized, and detailed characterization and mechanical properties tests were performed. The most promising techniques were selected and used to produce an Engineered Re AMBR-sized combustion chamber for testing at Aerojet Rocketdyne.

  17. Experimental evaluation of the Battelle accelerated test design for the solar array at Mead, Nebraska

    NASA Technical Reports Server (NTRS)

    Frickland, P. O.; Repar, J.

    1982-01-01

    A previously developed test design for accelerated aging of photovoltaic modules was experimentally evaluated. The studies included a review of relevant field experience, environmental chamber cycling of full size modules, and electrical and physical evaluation of the effects of accelerated aging during and after the tests. The test results indicated that thermally induced fatigue of the interconnects was the primary mode of module failure as measured by normalized power output. No chemical change in the silicone encapsulant was detectable after 360 test cycles.

  18. National Ignition Facility Target Chamber

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

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The twomore » isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

  19. Above the weathering front: contrasting approaches to the study and classification of weathered mantle

    NASA Astrophysics Data System (ADS)

    Ehlen, Judy

    2005-04-01

    Weathered mantle comprises the materials above bedrock and below the soil. It can vary in thickness from millimeters to hundreds of meters, depending primarily on climate and parent material. Study of the weathered mantle comes within the realms of four disciplines: geology, geomorphology, soil science, and civil engineering, each of which uses a different approach to describe and classify the material. The approaches of engineers, geomorphologists, and geologists are contrasted and compared using example papers from the published literature. Soil scientists rarely study the weathering profile as such, and instead concentrate upon soil-forming processes and spatial distribution primarily in the solum. Engineers, including engineering geologists, study the stability and durability of the weathered mantle and the strength of the materials using sophisticated procedures to classify weathered materials, but their approach tends to be one-dimensional. Furthermore, they believe that the study of mineralogy and chemistry is not useful. Geomorphologists deal with weathering in terms of process—how the weathered mantle is formed—and with respect to landform evolution using a spatial approach. Geologists tend to ignore the weathered mantle because it is not bedrock, or to study its mineralogy and/or chemistry in the laboratory. I recommend that the approaches of the various disciplines be integrated—geomorphologists and geologists should consider using engineering weathering classifications, and geologists should adopt a spatial perspective to weathering, as should engineers and engineering geologists.

  20. Weather and climate

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human losses caused by weather, (3) development of space system capability to manage and control air pollutant concentrations, and (4) establish mechanisms for the national examination of deliberate and inadvertent means for modifying weather and climate.

  1. Metal explosion chambers: designing, manufacturing, application

    NASA Astrophysics Data System (ADS)

    Stoyanovskii, O. I.; Zlobin, B. S.; Shtertser, A. A.; Meshcheryakov, Y. P.

    2017-10-01

    Designing of explosion chambers is based on research investigations of the chamber body stress-strain state, which is determined by numerical computation and experimentally by the strain gage technique. Studies show that chamber bottoms are the most loaded elements, and maximal stresses arise in chamber poles. Increasing the shell thickness around poles by welding-in an insert is a simple and saving way to solve this problem. There are structural solutions, enabling reliable hermetic closure and preventing leakage of detonation products from the chamber. Explosion chambers are employed in scientific research and in different industrial applications: explosive welding and hardening, synthesis of new materials, disposal of expired ammunition, and etc.

  2. Degradation Behavior and Accelerated Weathering of Composite Boards Produced from Waste Tetra Pak® Packaging Materials

    Treesearch

    Nural Yilgor; Coskun Kose; Evren Terzi; Aysel Kanturk Figen; Rebecca Ibach; S. Nami Kartal; Sabriye Piskin

    2014-01-01

    Manufacturing panels from Tetra Pak® (TP) packaging material might be an alternative to conventional wood-based panels. This study evaluated some chemical and physical properties as well as biological, weathering, and fire performance of panels with and without zinc borate (ZnB) by using shredded TP packaging cartons. Such packaging material, a worldwide well-known...

  3. In-vitro Study on Temperature Changes in the Pulp Chamber Due to Thermo-Cure Glass Ionomer Cements

    PubMed Central

    van Duinen, Raimond NB; Shahid, Saroash; Hill, Robert

    2016-01-01

    The application of the Glass Ionomer Cements in clinical dentistry is recommended due to properties such as fluoride release, chemical adhesion to tooth, negligible setting shrinkage, and coefficient of thermal expansion close to tooth, low creep, and good color stability. However, the cement is vulnerable to early exposure to moisture due to slow setting characteristics. The uses of external energy such as ultrasound and radiant heat (Thermo-curing) have been reported to provide acceleration of the setting chemistry and enhance physical properties. Aim: The aim of this in vitro study was to analyze temperature changes in the pulpal chamber when using radiant heat to accelerate the setting of GICs. Material and Methods:The encapsulated GIC Equia Forte was used for this study. The temperature changes in the pulp were measured using thermocouple in the cavities which were 2,6 and 4,7mm deep with and without filling. Results:The results showed that a temperature rise (ΔT) in the pulp chamber was 3,7°C. ΔT for the 2.6mm and 4.7mm deep cavity and without placing any restoration the temperature was 4,2°C and 2,6°C respectively. After the restoration has been placed, the ΔT range in the pulp chamber was lower ranging from 1.9°C to 2.4°C. Conclusion: It could be concluded that Thermo-curing of the GIC during the setting is safe for the pulp and can be recommended in clinical practice. PMID:28275275

  4. NSTAR Extended Life Test Discharge Chamber Flake Analysis

    NASA Technical Reports Server (NTRS)

    deGroh, Kim K.; Banks, Bruce A.; Karniotis, Christina A.

    2005-01-01

    The Extended Life Test (ELT) of the NASA Solar Electric Propulsion Technology Readiness (NSTAR) ion thruster was concluded after 30,352 hours of operation. The ELT was conducted using the Deep Space 1 (DS1) back-up flight engine, a 30 cm diameter xenon ion thruster. Post-test inspection of the ELT engine revealed numerous contaminant flakes distributed over the bottom of the cylindrical section of the anode within the discharge chamber (DC). Extensive analyses were conducted to determine the source of the particles, which is critical to the understanding of degradation mechanisms of long life ion thruster operation. Analyses included: optical microscopy (OM) and particle length histograms, field emission scanning electron microscopy (FESEM) combined with energy dispersive spectroscopy (EDS), and atomic oxygen plasma exposure tests. Analyses of the particles indicate that the majority of the DC flakes consist of a layered structure, typically with either two or three layers. The flakes comprising two layers were typically found to have a molybdenum-rich (Mo-rich) layer on one side and a carbon-rich (C-rich) layer on the other side. The flakes comprising three layers were found to be sandwich-like structures with Mo-rich exterior layers and a C-rich interior layer. The presence of the C-rich layers indicates that these particles were produced by sputter deposition build-up on a surface external to the discharge chamber from ion sputter erosion of the graphite target in the test chamber. This contaminant layer became thick enough that particles spalled off, and then were electro-statically attracted into the ion thruster interior, where they were coated with Mo from internal sputter erosion of the screen grid and cathode components. Atomic oxygen tests provided evidence that the DC chamber flakes are composed of a significant fraction of carbon. Particle size histograms further indicated that the source of the particles was spalling of carbon flakes from downstream

  5. Sliding and rolling behavior of water droplets on an ordered nanoball matrix fluorocarbon polymer layer under simulated weather conditions

    NASA Astrophysics Data System (ADS)

    Jiang, Xieqiang; Wan, Jie; Han, Haoxu; Wang, Yiping; Li, Kang; Wang, Qingjun

    2018-09-01

    Ordered nanoball matrix fluorocarbon polymer layers were produced with two different fluorocarbon polymers on an anodized aluminum oxide (AAO) surface. These treated surfaces each exhibited hydrophobicity or superhydrophobicity. The dynamic behavior of a droplet sliding down these surfaces was captured by high-speed photography under simulated weather conditions including at room temperature (25 °C) and low temperature (5 °C) with various relative humidities (30%-80%). By analyzing the trajectory of a marker in the captured video frame-by-frame, we distinguished the slipping and rolling behaviors and analyzed the internal fluidity by calculating the ratio of these two motions. Both the pore diameters of the substrate matrix and the environmental conditions play a dominant role in the resultant sliding acceleration of a water droplet. At room temperature (25 °C) and 30% relative humidity, the sliding acceleration of the droplet on the fluoropolymer layer decreased by 0.5 m·s-2 -0.6 m·s-2 as the pore diameters of the underlying AAO substrates increased. The sliding acceleration underwent a 25%-50% decrease under extreme environmental conditions (5 °C and 80% RH). These phenomena proved that a wetting transition from the Cassie-Baxter model to the Wenzel model can partially occur under various weather conditions.

  6. Liquid rocket engine self-cooled combustion chambers

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Self-cooled combustion chambers are chambers in which the chamber wall temperature is controlled by methods other than fluid flow within the chamber wall supplied from an external source. In such chambers, adiabatic wall temperature may be controlled by use of upstream fluid components such as the injector or a film-coolant ring, or by internal flow of self-contained materials; e.g. pyrolysis gas flow in charring ablators, and the flow of infiltrated liquid metals in porous matrices. Five types of self-cooled chambers are considered in this monograph. The name identifying the chamber is indicative of the method (mechanism) by which the chamber is cooled, as follows: ablative; radiation cooled; internally regenerative (Interegen); heat sink; adiabatic wall. Except for the Interegen and heat sink concepts, each chamber type is discussed separately. A separate and final section of the monograph deals with heat transfer to the chamber wall and treats Stanton number evaluation, film cooling, and film-coolant injection techniques, since these subjects are common to all chamber types. Techniques for analysis of gas film cooling and liquid film cooling are presented.

  7. Vacuum Plasma Spray Forming of Tungsten Lorentz Force Accelerator Components

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank R.

    2001-01-01

    The Vacuum Plasma Spray (VPS) Laboratory at NASA's Marshall Space Flight Center has developed and demonstrated a fabrication technique using the VPS process to form anode sections for a Lorentz force accelerator from tungsten. Lorentz force accelerators are an attractive form of electric propulsion that provides continuous, high-efficiency propulsion at useful power levels for such applications as orbit transfers or deep space missions. The VPS process is used to deposit refractory metals such as tungsten onto a graphite mandrel of the desired shape. Because tungsten is reactive at high temperatures, it is thermally sprayed in an inert environment where the plasma gun melts and accelerates the metal powder onto the mandrel. A three-axis robot inside the chamber controls the motion of the plasma spray torch. A graphite mandrel acts as a male mold, forming the required contour and dimensions of the inside surface of the anode. This paper describes the processing techniques, design considerations, and process development associated with the VPS forming of the Lorentz force accelerator.

  8. Simulating synchrotron radiation in accelerators including diffuse and specular reflections

    DOE PAGES

    Dugan, G.; Sagan, D.

    2017-02-24

    An accurate calculation of the synchrotron radiation flux within the vacuum chamber of an accelerator is needed for a number of applications. These include simulations of electron cloud effects and the design of radiation masking systems. To properly simulate the synchrotron radiation, it is important to include the scattering of the radiation at the vacuum chamber walls. To this end, a program called synrad3d has been developed which simulates the production and propagation of synchrotron radiation using a collection of photons. Photons generated by a charged particle beam are tracked from birth until they strike the vacuum chamber wall wheremore » the photon is either absorbed or scattered. Both specular and diffuse scattering is simulated. If a photon is scattered, it is further tracked through multiple encounters with the wall until it is finally absorbed. This paper describes the synrad3d program, with a focus on the details of its scattering model, and presents some examples of the program’s use.« less

  9. Aviation Weather Observations for Supplementary Aviation Weather Reporting Stations (SAWRS) and Limited Aviation Weather Reporting Stations (LAWRS). Federal Meteorological Handbook No. 9.

    ERIC Educational Resources Information Center

    Department of Transportation, Washington, DC.

    This handbook provides instructions for observing, identifying, and recording aviation weather at Limited Aviation Weather Reporting Stations (LAWRS) and Supplementary Aviation Weather Reporting Stations (SAWRS). Official technical definitions, meteorological and administrative procedures are outlined. Although this publication is intended for use…

  10. Genetically optimizing weather predictions

    NASA Astrophysics Data System (ADS)

    Potter, S. B.; Staats, Kai; Romero-Colmenero, Encarni

    2016-07-01

    humidity, air pressure, wind speed and wind direction) into a database. Built upon this database, we have developed a remarkably simple approach to derive a functional weather predictor. The aim is provide up to the minute local weather predictions in order to e.g. prepare dome environment conditions ready for night time operations or plan, prioritize and update weather dependent observing queues. In order to predict the weather for the next 24 hours, we take the current live weather readings and search the entire archive for similar conditions. Predictions are made against an averaged, subsequent 24 hours of the closest matches for the current readings. We use an Evolutionary Algorithm to optimize our formula through weighted parameters. The accuracy of the predictor is routinely tested and tuned against the full, updated archive to account for seasonal trends and total, climate shifts. The live (updated every 5 minutes) SALT weather predictor can be viewed here: http://www.saao.ac.za/ sbp/suthweather_predict.html

  11. Defining the `negative emission' capacity of global agriculture deployed for enhanced rock weathering

    NASA Astrophysics Data System (ADS)

    Beerling, D. J.; Taylor, L.; Banwart, S. A.; Kantzas, E. P.; Lomas, M.; Mueller, C.; Ridgwell, A.; Quegan, S.

    2016-12-01

    Enhanced rock weathering involves application of crushed silicates (e.g. basalt) to the landscape to accelerate their chemical breakdown to release base cations and form bicarbonate that ultimate sequester CO2 in the oceans. Global croplands cover an area of 12 million km2 and might be deployed for long-term removal of anthropogenic CO2 through enhanced rock weathering with a number of co-benefits for food security. This presentation assesses the potential of this strategy to contribute to `negative emissions' as defined by a suite of simulations coupling a detailed model of rock grain weathering by crop root-microbial processes with a managed land dynamic global vegetation model driven by the `business as usual' future climate change scenarios. We calculate potential atmospheric CO2 drawdown over the next century by introducing a strengthened C-sink term into the global carbon cycle model within an intermediate complexity Earth system model. Our simulations indicate agricultural lands deployed in this way constitute a `low tech' biological negative emissions strategy. As part of a wider portfolio of options, this strategy might contribute to limiting future warming to 2oC, subject to economic costs and energy requirements.

  12. Differences in the importance of weather and weather-based decisions among campers in Ontario parks (Canada)

    NASA Astrophysics Data System (ADS)

    Hewer, Micah J.; Scott, Daniel J.; Gough, William A.

    2017-10-01

    Parks and protected areas represent an important resource for tourism in Canada, in which camping is a common recreational activity. The important relationship between weather and climate with recreation and tourism has been widely acknowledged within the academic literature. Howbeit, the need for activity-specific assessments has been identified as an on-going need for future research in the field of tourism climatology. Furthermore, very little is known about the interrelationships between personal characteristics and socio-demographics with weather preferences and behavioural thresholds. This study uses a stated climate preferences approach (survey responses) to explore differences in the importance of weather and related weather-based decisions among summer campers in Ontario parks. Statistically significant differences were found among campers for each of the four dependent variables tested in this study. Physically active campers placed greater importance on weather but were still more tolerant of adverse weather conditions. Older campers placed greater importance on weather. Campers travelling shorter distances placed greater importance on weather and were more likely to leave the park early due to adverse weather. Campers staying for longer periods of time were less likely to leave early due to weather and were willing to endure longer durations of adverse weather conditions. Beginner campers placed greater importance on weather, were more likely to leave early due to weather and recorded lower temporal weather thresholds. The results of this study contribute to the study of tourism climatology by furthering understanding of how personal characteristics such as gender, age, activity selection, trip duration, distance travelled, travel experience and life cycles affect weather preferences and decisions, focusing this time on recreational camping in a park tourism context.

  13. Differences in the importance of weather and weather-based decisions among campers in Ontario parks (Canada).

    PubMed

    Hewer, Micah J; Scott, Daniel J; Gough, William A

    2017-10-01

    Parks and protected areas represent an important resource for tourism in Canada, in which camping is a common recreational activity. The important relationship between weather and climate with recreation and tourism has been widely acknowledged within the academic literature. Howbeit, the need for activity-specific assessments has been identified as an on-going need for future research in the field of tourism climatology. Furthermore, very little is known about the interrelationships between personal characteristics and socio-demographics with weather preferences and behavioural thresholds. This study uses a stated climate preferences approach (survey responses) to explore differences in the importance of weather and related weather-based decisions among summer campers in Ontario parks. Statistically significant differences were found among campers for each of the four dependent variables tested in this study. Physically active campers placed greater importance on weather but were still more tolerant of adverse weather conditions. Older campers placed greater importance on weather. Campers travelling shorter distances placed greater importance on weather and were more likely to leave the park early due to adverse weather. Campers staying for longer periods of time were less likely to leave early due to weather and were willing to endure longer durations of adverse weather conditions. Beginner campers placed greater importance on weather, were more likely to leave early due to weather and recorded lower temporal weather thresholds. The results of this study contribute to the study of tourism climatology by furthering understanding of how personal characteristics such as gender, age, activity selection, trip duration, distance travelled, travel experience and life cycles affect weather preferences and decisions, focusing this time on recreational camping in a park tourism context.

  14. Finding past weather...Fast - Public Affairs - NOAA's National Weather

    Science.gov Websites

    government web resources and services. Home >>Climate Data Finding past weather...Fast Climate data Weather Forecast Offices (WFOs). First, find the location you need climate data for on the following map the left side of the page there will be a section called Climate in yellow-colored text. You may have

  15. National Weather Service

    MedlinePlus

    ... Data SAFETY Floods Tsunami Beach Hazards Wildfire Cold Tornadoes Fog Air Quality Heat Hurricanes Lightning Safe Boating ... Winter Weather Forecasts River Flooding Latest Warnings Thunderstorm/Tornado Outlook Hurricanes Fire Weather Outlooks UV Alerts Drought ...

  16. Microclimatic, chemical, and mineralogical evidence for tafoni weathering processes on the Miaowan Island, South China

    NASA Astrophysics Data System (ADS)

    Huang, Rihui; Wang, Wei

    2017-02-01

    Tafoni were widely distributed around the world; however, their processes of development remain unclear. In this study, the roles of microclimatic, geochemical and mineralogical processes on tafoni development along the subtropical coastline of the Miaowan Island, south China, are investigated. Field observations were carried out during three visits to the island over a four-year period (2011-2015). The orientation of 184 tafoni openings were measured, and micrometeorological changes of three tafoni on opposite sides of the island were monitored by pocket weather trackers (Kestrel 4500) in two periods. Samples of residual debris inside three tafoni hosted in a large boulder, the parent rock of the tafoni, and from the weathering profile of a nearby bedrock outcrop were collected for X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses. The field observations showed that tafoni were of different sizes and constantly produced flakes and debris inside the tafoni caves, indicating their on-going active development. An increase in Na in residual debris in tafoni caves on the Miaowan Island is the most obvious evidence of salt weathering. Salt weathering inside tafoni caves is not intense and does not match the salt-rich environment outside the caves, indicating that the influence of salt is not strong. The loss of K, Ca, and Mg in the residue samples, and the appearance of the clay mineral montmorillonite are caused by chemical weathering. Most of the tafoni openings face mountains, demonstrating the effect of humidity in tafoni weathering. Tafoni cave shapes are related to the distribution of humid water vapour, which tends to collect at the top of the cave, and leads to more intensive development here than in other parts. Drastic daily changes in relative humidity inside tafoni caves accelerate mechanical weathering owing to swelling and shrinking of salt and clay minerals. The Miaowan Island tafoni are formed by weathering, but they cannot be simply

  17. Dependence with air density of the response of the PTW SourceCheck ionization chamber for low energy brachytherapy sources

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

    Tornero-López, Ana M.; Guirado, Damián; Ruiz-Arrebola, Samuel

    2013-12-15

    altitude and changes in the weather conditions may produce significant density corrections, and that effect should be taken into account. This effect is chamber-dependent, indicating that a specific calibration is necessary for each particular chamber. To our knowledge, this correction has not been considered so far for SourceCheck ionization chambers, but its magnitude cannot be neglected in clinical practice. The atmospheric pressure and temperature at which the chamber was calibrated need to be taken into account, and they should be reported in the calibration certificate. In addition, each institution should analyze the particular response of its SourceCheck ionization chamber and compute the adequate correction factors. In the absence of a suitable pressure chamber, a possibility for this assessment is to take measurements at different altitudes, spanning a wide enough air density range.« less

  18. The effect of weathering on ecopersistence, reactivity, and potential toxicity of naturally occurring asbestos and asbestiform minerals.

    PubMed

    Enrico Favero-Longo, Sergio; Turci, Francesco; Tomatis, Maura; Compagnoni, Roberto; Piervittori, Rosanna; Fubini, Bice

    2009-01-01

    The mechanisms underlying asbestos toxicity mainly rely on experiments performed on "laboratory" fibers, but little data is available on naturally occurring asbestos (NOA). Human exposure to NOA is subject to their ecopersistence and the modulation of their potential toxicity following weathering. The effect of weathering on three fibrous minerals from the Italian Western Alps, chrysotile, tremolite, and balangeroite-a Fe-rich asbestiform mineral-was investigated by mimicking more than 100 yr of physical (freezing-thawing/wetting-drying cycles in a climatic chamber) and biochemical forces (incubation with oxalic acid). Ion release, evaluated by means of inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and variation in chemical composition, evaluated by scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), indicated that weathering modified the fibers in the series: chrysotile > balangeroite > tremolite. Kinetics of ion release from the fibers (Mg, Fe, and Si) revealed different ion removal pathways. Tremolite was poorly affected. Chrysotile preferentially released cations up to a plateau, with physical and biochemical forces acting competitively. Conversely, for balangeroite, upon which weathering forces acted synergistically, the initial loss of ions facilitated further dissolution and more Si than Mg was released, suggesting an ongoing collapse of the crystal structure. Depletion of redox-reactive ions produced a significant reduction in fiber-derived *OH radicals (EPR, spin-trapping technique), but the fibrous nature was always retained. Despite weathered fibers appearing less toxic than "stored/laboratory" ones, NOA is to be considered far from safe because of fibrous nature and residual surface reactivity. Risk assessment needs to consider the effect of weathering on exposures. Both tremolite and balangeroite may contaminate, in some areas, chrysotile asbestos. However, in contrast to tremolite, balangeroite

  19. Electrodeless plasma acceleration system using rotating magnetic field method

    NASA Astrophysics Data System (ADS)

    Furukawa, T.; Takizawa, K.; Kuwahara, D.; Shinohara, S.

    2017-11-01

    We have proposed Rotating Magnetic Field (RMF) acceleration method as one of electrodeless plasma accelerations. In our experimental scheme, plasma generated by an rf (radio frequency) antenna, is accelerated by RMF antennas, which consist of two-pair, opposed, facing coils, and these antennas are outside of a discharge tube. Therefore, there is no wear of electrodes, degrading the propulsion performance. Here, we will introduce our RMF acceleration system developed, including the experimental device, e.g., external antennas, a tapered quartz tube, a vacuum chamber, external magnets, and a pumping system. In addition, we can change RMF operation parameters (RMF applied current IRMF and RMF current phase difference ϕ, focusing on RMF current frequency fRMF) by adjusting matching conditions of RMF, and investigate the dependencies on plasma parameters (electron density ne and ion velocity vi); e.g., higher increases of ne and vi (˜360 % and 55 %, respectively) than previous experimental results were obtained by decreasing fRMF from 5 MHz to 0.7 MHz, whose RMF penetration condition was better according to Milroy's expression. Moreover, time-varying component of RMF has been measured directly to survey the penetration condition experimentally.

  20. SU-F-T-72: Experimental Determination of the Positionuncertainties for ROOS Ionization Chambers in Clinical Electron Beams

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

    Voigts-Rhetz, P von; Zink, K; University Hospital Giessen-Marburg, Marburg

    2016-06-15

    Purpose: National and international dosimetry protocols assume a position accuracy for ionization chambers of less than 0.2mm. To follow this precept the manufacturer PTW-Freiburg introduced a positioning assistance system (TRUFIX) for their particular ion chambers. Aim of this study is an experimental investigation of the positioning uncertainties for ROOS-type ionization chambers. Methods: For all measurements a linear accelerator Elekta Synergie was used. The experiments were performed in a water-phantom. To collimate the electron beam a 10×10cm{sup 2} applicator was installed. All measured depth dose curves were normalized to their maximum. In all cases the TRUFIX system was applied for chambermore » positioning. For the first measurement series, to determine the positioning reproducibility of a ROOS chamber, one person placed the chamber three times in a 6 MeV electron beam. The mean value of this three measurements was the reference for further six random persons who repeated this procedure. The results were compared for different depths (R{sub 50}, z{sub ref} and R{sub p}). To investigate the impact of different individual chambers of the same type 10 different ROOS chambers were placed by the same person in a 6, 12 and 18MeV electron beam and the measured reference depths z{sub ref} were compared. Results: The absolute positioning reproducibility is less than 0.1mm for the same person. The positioning uncertainties are increasing up to +/−0.3mm if different persons perform the chamber’s positioning within the water phantom. The comparison of the 10 different ROOS chambers resulted in reference depths z{sub ref} with deviations in the range of +/−0.45mm for all energies. Conclusion: The position accuracy of 0.2mm can be fulfilled with the TRUFIX system. The comparison of the 10 different ROOS ionization chambers showed noticeable deviations in the determined reference depth. The impact of a positioning uncertainty of about 0.3–0.4mm on the total

  1. Weather Fundamentals: Meteorology. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

  2. Diagnosis of Acceleration, Reconnection, Turbulence, and Heating

    NASA Astrophysics Data System (ADS)

    Dufor, Mikal T.; Jemiolo, Andrew J.; Keesee, Amy; Cassak, Paul; Tu, Weichao; Scime, Earl E.

    2017-10-01

    The DARTH (Diagnosis of Acceleration, Reconnection, Turbulence, and Heating) experiment is an intermediate-scale, experimental facility designed to study magnetic reconnection at and below the kinetic scale of ions and electrons. The experiment will have non-perturbative diagnostics with high temporal and three-dimensional spatial resolution, giving it the capability to investigate kinetic-scale physics. Of specific scientific interest are particle acceleration, plasma heating, turbulence and energy dissipation during reconnection. Here we will describe the magnetic field system and the two plasma guns used to create flux ropes that then merge through magnetic reconnection. We will also describe the key diagnostic systems: laser induced fluorescence (LIF) for ion vdf measurements, a 300 GHz microwave scattering system for sub-mm wavelength fluctuation measurements and a Thomson scattering laser for electron vdf measurements. The vacuum chamber is designed to provide unparalleled access for these particle diagnostics. The scientific goals of DARTH are to examine particle acceleration and heating during, the role of three-dimensional instabilities during reconnection, how reconnection ceases, and the role of impurities and asymmetries in reconnection. This work was supported by the by the O'Brien Energy Research Fund.

  3. Ionization-chamber smoke detector system

    DOEpatents

    Roe, Robert F.

    1976-10-19

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system is designed to reduce false alarms caused by fluctuations in ambient temperature. Means are provided for periodically firing the gas discharge triode and each time recording the triggering voltage required. A computer compares each triggering voltage with its predecessor. The computer is programmed to energize an alarm if the difference between the two compared voltages is a relatively large value indicative of particulates in the measuring chamber and to disregard smaller differences typically resulting from changes in ambient temperature.

  4. Helicon Plasma Injector and Ion Cyclotron Acceleration Development in the VASIMR Experiment

    NASA Technical Reports Server (NTRS)

    Squire, Jared P.; Chang, Franklin R.; Jacobson, Verlin T.; McCaskill, Greg E.; Bengtson, Roger D.; Goulding, Richard H.

    2000-01-01

    In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) radio frequency (rf) waves both produce the plasma and then accelerate the ions. The plasma production is done by action of helicon waves. These waves are circular polarized waves in the direction of the electron gyromotion. The ion acceleration is performed by ion cyclotron resonant frequency (ICRF) acceleration. The Advanced Space Propulsion Laboratory (ASPL) is actively developing efficient helicon plasma production and ICRF acceleration. The VASIMR experimental device at the ASPL is called VX-10. It is configured to demonstrate the plasma production and acceleration at the 10kW level to support a space flight demonstration design. The VX-10 consists of three electromagnets integrated into a vacuum chamber that produce magnetic fields up to 0.5 Tesla. Magnetic field shaping is achieved by independent magnet current control and placement of the magnets. We have generated both helium and hydrogen high density (>10(exp 18) cu m) discharges with the helicon source. ICRF experiments are underway. This paper describes the VX-10 device, presents recent results and discusses future plans.

  5. Climate, weather, space weather: model development in an operational context

    NASA Astrophysics Data System (ADS)

    Folini, Doris

    2018-05-01

    Aspects of operational modeling for climate, weather, and space weather forecasts are contrasted, with a particular focus on the somewhat conflicting demands of "operational stability" versus "dynamic development" of the involved models. Some common key elements are identified, indicating potential for fruitful exchange across communities. Operational model development is compelling, driven by factors that broadly fall into four categories: model skill, basic physics, advances in computer architecture, and new aspects to be covered, from costumer needs over physics to observational data. Evaluation of model skill as part of the operational chain goes beyond an automated skill score. Permanent interaction between "pure research" and "operational forecast" people is beneficial to both sides. This includes joint model development projects, although ultimate responsibility for the operational code remains with the forecast provider. The pace of model development reflects operational lead times. The points are illustrated with selected examples, many of which reflect the author's background and personal contacts, notably with the Swiss Weather Service and the Max Planck Institute for Meteorology, Hamburg, Germany. In view of current and future challenges, large collaborations covering a range of expertise are a must - within and across climate, weather, and space weather. To profit from and cope with the rapid progress of computer architectures, supercompute centers must form part of the team.

  6. Monte Carlo calculated correction factors for diodes and ion chambers in small photon fields.

    PubMed

    Czarnecki, D; Zink, K

    2013-04-21

    The application of small photon fields in modern radiotherapy requires the determination of total scatter factors Scp or field factors Ω(f(clin), f(msr))(Q(clin), Q(msr)) with high precision. Both quantities require the knowledge of the field-size-dependent and detector-dependent correction factor k(f(clin), f(msr))(Q(clin), Q(msr)). The aim of this study is the determination of the correction factor k(f(clin), f(msr))(Q(clin), Q(msr)) for different types of detectors in a clinical 6 MV photon beam of a Siemens KD linear accelerator. The EGSnrc Monte Carlo code was used to calculate the dose to water and the dose to different detectors to determine the field factor as well as the mentioned correction factor for different small square field sizes. Besides this, the mean water to air stopping power ratio as well as the ratio of the mean energy absorption coefficients for the relevant materials was calculated for different small field sizes. As the beam source, a Monte Carlo based model of a Siemens KD linear accelerator was used. The results show that in the case of ionization chambers the detector volume has the largest impact on the correction factor k(f(clin), f(msr))(Q(clin), Q(msr)); this perturbation may contribute up to 50% to the correction factor. Field-dependent changes in stopping-power ratios are negligible. The magnitude of k(f(clin), f(msr))(Q(clin), Q(msr)) is of the order of 1.2 at a field size of 1 × 1 cm(2) for the large volume ion chamber PTW31010 and is still in the range of 1.05-1.07 for the PinPoint chambers PTW31014 and PTW31016. For the diode detectors included in this study (PTW60016, PTW 60017), the correction factor deviates no more than 2% from unity in field sizes between 10 × 10 and 1 × 1 cm(2), but below this field size there is a steep decrease of k(f(clin), f(msr))(Q(clin), Q(msr)) below unity, i.e. a strong overestimation of dose. Besides the field size and detector dependence, the results reveal a clear dependence of the

  7. Space Weather Impacts to Mariners

    Science.gov Websites

    Tsunamis 406 EPIRB's National Weather Service Marine Forecasts SPACE WEATHER IMPACTS TO MARINERS Marine present an even greater danger near shore or any shallow waters? Space Weather Impacts to Mariners Don't ), Notices to Mariners, Special Paragraphs: "(73) SPACE WEATHER IMPACTS. There is a growing potential

  8. Process-based modeling of silicate mineral weathering responses to increasing atmospheric CO2 and climate change

    NASA Astrophysics Data System (ADS)

    Banwart, Steven A.; Berg, Astrid; Beerling, David J.

    2009-12-01

    A mathematical model describes silicate mineral weathering processes in modern soils located in the boreal coniferous region of northern Europe. The process model results demonstrate a stabilizing biological feedback mechanism between atmospheric CO2 levels and silicate weathering rates as is generally postulated for atmospheric evolution. The process model feedback response agrees within a factor of 2 of that calculated by a weathering feedback function of the type generally employed in global geochemical carbon cycle models of the Earth's Phanerozoic CO2 history. Sensitivity analysis of parameter values in the process model provides insight into the key mechanisms that influence the strength of the biological feedback to weathering. First, the process model accounts for the alkalinity released by weathering, whereby its acceleration stabilizes pH at values that are higher than expected. Although the process model yields faster weathering with increasing temperature, because of activation energy effects on mineral dissolution kinetics at warmer temperature, the mineral dissolution rate laws utilized in the process model also result in lower dissolution rates at higher pH values. Hence, as dissolution rates increase under warmer conditions, more alkalinity is released by the weathering reaction, helping maintain higher pH values thus stabilizing the weathering rate. Second, the process model yields a relatively low sensitivity of soil pH to increasing plant productivity. This is due to more rapid decomposition of dissolved organic carbon (DOC) under warmer conditions. Because DOC fluxes strongly influence the soil water proton balance and pH, this increased decomposition rate dampens the feedback between productivity and weathering. The process model is most sensitive to parameters reflecting soil structure; depth, porosity, and water content. This suggests that the role of biota to influence these characteristics of the weathering profile is as important, if not

  9. Plant and mycorrhizal weathering at the laboratory mesocosm scale

    NASA Astrophysics Data System (ADS)

    Andrews, M. Y.; Leake, J.; Banwart, S. A.; Beerling, D. J.

    2011-12-01

    The evolutionary development of large vascular land plants in the Paleozoic is hypothesized to have enhanced weathering of Ca and Mg silicate minerals. This plant-centric view overlooks the fact that plants and their associated mycorrhizal fungi co-evolved. Many weathering processes usually ascribed to plants may actually be driven by the combined activities of roots and mycorrhizal fungi. This study focuses on two key evolutionary events in plant and fungal evolution: 1) the transition from gymnosperm-only to mixed angiosperm-gymnosperm forests in the Mesozoic and 2) the similarly timed rise of ectomycorrhizal fungi (EM) in a previously arbuscular mycorrhizal (AM) only world. Here we present results from a novel mesocosm-scale laboratory experiment designed to allow investigation of plant- and mycorrhizae-driven carbon fluxes and mineral weathering at different soil depths, and under ambient (400 ppm) and elevated (1500 ppm) atmospheric CO2. To test our hypothesis that photosynthetic carbon flux from the plant to the roots and fungal partner drives biological weathering of minerals, we studied five mycorrhizal plant species: the gymnosperms Sequoia sempervirens (AM), Pinus sylvestris (EM) and Ginkgo biloba (AM), and two angiosperms, Magnolia grandiflora (AM) and Betula pendula (EM). This long term (7-9 months) experiment was grown in controlled environment chambers, with replicated systems at two atmospheric CO2 levels. Each mycorrhizal plant had access to isolated horizontal mesh cores containing crushed granite and basalt at three depths, in a compost:sand (50:50 vol:vol) bulk substrate, with appropriate plant-free and mineral-free controls. 14CO2 pulse-labeling provided a snapshot of the magnitude, timing, and allocation of carbon through the atmosphere-plant-fungi-soil system and also measured mycorrhizal fungal activity associated with the target granite and basalt. Total plant and fungal biomass were also assessed in relation to +/- mineral treatments and

  10. A Systematic Approach to the Study of Accelerated weathering of Building Joint Sealants

    Treesearch

    Christopher C. White; Donald L. Hunston; Kar Tean Tan; James J. Filliben; Adam L. Pintar; Greg Schueneman

    2012-01-01

    An accurate service life prediction model is needed for building joint sealants in order to greatly reduce the time to market of a new product and reduce the risk of introducing a poorly performing product into the marketplace. A stepping stone to the success of this effort is the precise control of environmental variables in a laboratory accelerated test apparatus in...

  11. Weather impacts on space operations

    NASA Astrophysics Data System (ADS)

    Madura, J.; Boyd, B.; Bauman, W.; Wyse, N.; Adams, M.

    The efforts of the 45th Weather Squadron of the USAF to provide weather support to Patrick Air Force Base, Cape Canaveral Air Force Station, Eastern Range, and the Kennedy Space Center are discussed. Its weather support to space vehicles, particularly the Space Shuttle, includes resource protection, ground processing, launch, and Ferry Flight, as well as consultations to the Spaceflight Meteorology Group for landing forecasts. Attention is given to prelaunch processing weather, launch support weather, Shuttle launch commit criteria, and range safety weather restrictions. Upper level wind requirements are examined. The frequency of hourly surface observations with thunderstorms at the Shuttle landing facility, and lightning downtime at the Titan launch complexes are illustrated.

  12. Winter Weather Emergencies

    MedlinePlus

    Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

  13. NASA GSFC Space Weather Center - Innovative Space Weather Dissemination: Web-Interfaces, Mobile Applications, and More

    NASA Technical Reports Server (NTRS)

    Maddox, Marlo; Zheng, Yihua; Rastaetter, Lutz; Taktakishvili, A.; Mays, M. L.; Kuznetsova, M.; Lee, Hyesook; Chulaki, Anna; Hesse, Michael; Mullinix, Richard; hide

    2012-01-01

    The NASA GSFC Space Weather Center (http://swc.gsfc.nasa.gov) is committed to providing forecasts, alerts, research, and educational support to address NASA's space weather needs - in addition to the needs of the general space weather community. We provide a host of services including spacecraft anomaly resolution, historical impact analysis, real-time monitoring and forecasting, custom space weather alerts and products, weekly summaries and reports, and most recently - video casts. There are many challenges in providing accurate descriptions of past, present, and expected space weather events - and the Space Weather Center at NASA GSFC employs several innovative solutions to provide access to a comprehensive collection of both observational data, as well as space weather model/simulation data. We'll describe the challenges we've faced with managing hundreds of data streams, running models in real-time, data storage, and data dissemination. We'll also highlight several systems and tools that are utilized by the Space Weather Center in our daily operations, all of which are available to the general community as well. These systems and services include a web-based application called the Integrated Space Weather Analysis System (iSWA http://iswa.gsfc.nasa.gov), two mobile space weather applications for both IOS and Android devices, an external API for web-service style access to data, google earth compatible data products, and a downloadable client-based visualization tool.

  14. Cockpit weather information system

    NASA Technical Reports Server (NTRS)

    Tu, Jeffrey Chen-Yu (Inventor)

    2000-01-01

    Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

  15. Nanosatellites : A paradigm change for space weather studies.

    NASA Astrophysics Data System (ADS)

    Barthelemy, Mathieu

    2016-04-01

    Nanosatellites are changing the paradigm of space exploration and engineering. The past 15 years have seen a growing activity in this field, with a marked acceleration in the last 3 years. Whereas the educational value of nanosatellites is well recognized, their scientific and technological use is potentially extremely rich but not fully explored. Conventional attitudes towards space engineering need to be reviewed in light of the capabilities and characteristics of these miniature devices that enable approaches and applications not possible with traditional satellite platforms. After an evaluation of the past and near future nanosatellites missions in the domain of space weather and from the example of the Zegrensat/ATISE mission, we will give some perspectives on the possibilities opened by these small satellites.

  16. Weather dissemination and public usage

    NASA Technical Reports Server (NTRS)

    Stacey, M. S.

    1973-01-01

    The existing public usage of weather information was examined. A survey was conducted to substantiate the general public's needs for dissemination of current (0-12 hours) weather information, needs which, in a previous study, were found to be extensive and urgent. The goal of the study was to discover how the general public obtains weather information, what information they seek and why they seek it, to what use this information is put, and to further ascertain the public's attitudes and beliefs regarding weather reporting and the diffusion of weather information. Major findings from the study include: 1. The public has a real need for weather information in the 0-6 hour bracket. 2. The visual medium is preferred but due to the lack of frequent (0-6 hours) forecasts, the audio media only, i.e., telephone recordings and radio weathercasts, were more frequently used. 3. Weather information usage is sporadic.

  17. Severe Weather Forecast Decision Aid

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  18. Development of secondary chamber for tar cracking-improvement of wood pyrolysis performance in pre-vacuum chamber

    NASA Astrophysics Data System (ADS)

    Siahaan, S.; Homma, H.; Homma, H.

    2018-02-01

    Energy crisis and global warming, in other words, climate change are critical topics discussed in various parts of the world. Global warming primarily result from too much emission of carbon dioxide (CO2) in the atmosphere. To mitigate global warming, or climate change and improve electrification in rural areas, wood pyrolysis technology is developed in a laboratory scale, of which gases are directly applicable to the gas engine generator. Our laboratory has developed a prototype of wood pyrolysis plant with a pre-vacuum chamber. However, tar yield was around 40 wt% of feedstock. This research aims to reduce tar yield by secondary tar cracking. For the secondary tar cracking, a secondary pre-vacuum chamber is installed after primary pre-vacuum chamber. Gases generated in the primary pre-vacuum chamber are lead into the secondary chamber that is heated up to 1000 K. This paper reports performance of the secondary chamber for secondary tar cracking in homogeneous mode and heterogeneous mode with char.

  19. Pilot Weather Advisor System

    NASA Technical Reports Server (NTRS)

    Lindamood, Glenn; Martzaklis, Konstantinos Gus; Hoffler, Keith; Hill, Damon; Mehrotra, Sudhir C.; White, E. Richard; Fisher, Bruce D.; Crabill, Norman L.; Tucholski, Allen D.

    2006-01-01

    The Pilot Weather Advisor (PWA) system is an automated satellite radio-broadcasting system that provides nearly real-time weather data to pilots of aircraft in flight anywhere in the continental United States. The system was designed to enhance safety in two distinct ways: First, the automated receipt of information would relieve the pilot of the time-consuming and distracting task of obtaining weather information via voice communication with ground stations. Second, the presentation of the information would be centered around a map format, thereby making the spatial and temporal relationships in the surrounding weather situation much easier to understand

  20. Weather assessment and forecasting

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Data management program activities centered around the analyses of selected far-term Office of Applications (OA) objectives, with the intent of determining if significant data-related problems would be encountered and if so what alternative solutions would be possible. Three far-term (1985 and beyond) OA objectives selected for analyses as having potential significant data problems were large-scale weather forecasting, local weather and severe storms forecasting, and global marine weather forecasting. An overview of general weather forecasting activities and their implications upon the ground based data system is provided. Selected topics were specifically oriented to the use of satellites.

  1. Depth Profiles of Mg, Si, and Zn Implants in GaN by Trace Element Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Ravi Prasad, G. V.; Pelicon, P.; Mitchell, L. J.; McDaniel, F. D.

    2003-08-01

    GaN is one of the most promising electronic materials for applications requiring high-power, high frequencies, or high-temperatures as well as opto-electronics in the blue to ultraviolet spectral region. We have recently measured depth profiles of Mg, Si, and Zn implants in GaN substrates by the TEAMS particle counting method for both matrix and trace elements, using a gas ionization chamber. Trace Element Accelerator Mass Spectrometry (TEAMS) is a combination of Secondary Ion Mass Spectrometry (SIMS) and Accelerator Mass Spectrometry (AMS) to measure trace elements at ppb levels. Negative ions from a SIMS like source are injected into a tandem accelerator. Molecular interferences inherent with the SIMS method are eliminated in the TEAMS method. Negative ion currents are extremely low with GaN as neither gallium nor nitrogen readily forms negative ions making the depth profile measurements more difficult. The energies of the measured ions are in the range of 4-8 MeV. A careful selection of mass/charge ratios of the detected ions combined with energy-loss behavior of the ions in the ionization chamber eliminated molecular interferences.

  2. Enhanced Weathering Strategies for Stabilizing Climate and Averting Ocean Acidification

    NASA Technical Reports Server (NTRS)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2015-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m(exp -2) yr (exp -1)) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  3. Enhanced weathering strategies for stabilizing climate and averting ocean acidification

    NASA Astrophysics Data System (ADS)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2016-04-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m-2 yr-1) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  4. Environmental Education Tips: Weather Activities.

    ERIC Educational Resources Information Center

    Brainard, Audrey H.

    1989-01-01

    Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

  5. Aviation & Space Weather Policy Research: Integrating Space Weather Observations & Forecasts into Operations

    NASA Astrophysics Data System (ADS)

    Fisher, G.; Jones, B.

    2006-12-01

    The American Meteorological Society and SolarMetrics Limited are conducting a policy research project leading to recommendations that will increase the safety, reliability, and efficiency of the nation's airline operations through more effective use of space weather forecasts and information. This study, which is funded by a 3-year National Science Foundation grant, also has the support of the Federal Aviation Administration and the Joint Planning and Development Office (JPDO) who is planning the Next Generation Air Transportation System. A major component involves interviewing and bringing together key people in the aviation industry who deal with space weather information. This research also examines public and industrial strategies and plans to respond to space weather information. The focus is to examine policy issues in implementing effective application of space weather services to the management of the nation's aviation system. The results from this project will provide government and industry leaders with additional tools and information to make effective decisions with respect to investments in space weather research and services. While space weather can impact the entire aviation industry, and this project will address national and international issues, the primary focus will be on developing a U.S. perspective for the airlines.

  6. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, K.; Hong, S.; Park, S.; Kim, Y. Y.; Wi, G.

    2015-12-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  7. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, KiChang; Kim, Jae-Hun; Kim, Young Yun; Kwon, Yongki; Wi, Gwan-sik

    2016-07-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  8. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, K.; Hong, S.; Jangsuk, C.; Dong Kyu, K.; Jinyee, C.; Yeongoh, C.

    2016-12-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  9. Acceleration processes in the quasi-steady magnetoplasmadynamic discharge. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Boyle, M. J.

    1974-01-01

    The flow field characteristics within the discharge chamber and exhaust of a quasi-steady magnetoplasmadynamic (MPD) arcjet were examined to clarify the nature of the plasma acceleration process. The observation of discharge characteristics unperturbed by insulator ablation and terminal voltage fluctuations, first requires the satisfaction of three criteria: the use of refractory insulator materials; a mass injection geometry tailored to provide propellant to both electrode regions of the discharge; and a cathode of sufficient surface area to permit nominal MPD arcjet operation for given combinations of arc current and total mass flow. The axial velocity profile and electromagnetic discharge structure were measured for an arcjet configuration which functions nominally at 15.3 kA and 6 g/sec argon mass flow. An empirical two-flow plasma acceleration model is advanced which delineates inner and outer flow regions and accounts for the observed velocity profile and calculated thrust of the accelerator.

  10. Plant growth chamber M design

    NASA Technical Reports Server (NTRS)

    Prince, R. P.; Knott, W. M.

    1986-01-01

    Crop production is just one of the many processes involved in establishing long term survival of man in space. The benefits of integrating higher plants into the overall plan was recognized early by NASA through the Closed Ecological Life Support System (CELSS) program. The first step is to design, construct, and operate a sealed (gas, liquid, and solid) plant growth chamber. A 3.6 m diameter by 6.7 m high closed cylinder (previously used as a hypobaric vessel during the Mercury program) is being modified for this purpose. The chamber is mounted on legs with the central axis vertical. Entrance to the chamber is through an airlock. This chamber will be devoted entirely to higher plant experimentation. Any waste treatment, food processing or product storage studies will be carried on outside of this chamber. Its primary purpose is to provide input and output data on solids, liquids, and gases for single crop species and multiple species production using different nutrient delivery systems.

  11. Bridging the Transition from Mesoscale to Microscale Turbulence in Numerical Weather Prediction Models

    NASA Astrophysics Data System (ADS)

    Muñoz-Esparza, Domingo; Kosović, Branko; Mirocha, Jeff; van Beeck, Jeroen

    2014-12-01

    With a focus towards developing multiscale capabilities in numerical weather prediction models, the specific problem of the transition from the mesoscale to the microscale is investigated. For that purpose, idealized one-way nested mesoscale to large-eddy simulation (LES) experiments were carried out using the Weather Research and Forecasting model framework. It is demonstrated that switching from one-dimensional turbulent diffusion in the mesoscale model to three-dimensional LES mixing does not necessarily result in an instantaneous development of turbulence in the LES domain. On the contrary, very large fetches are needed for the natural transition to turbulence to occur. The computational burden imposed by these long fetches necessitates the development of methods to accelerate the generation of turbulence on a nested LES domain forced by a smooth mesoscale inflow. To that end, four new methods based upon finite amplitude perturbations of the potential temperature field along the LES inflow boundaries are developed, and investigated under convective conditions. Each method accelerated the development of turbulence within the LES domain, with two of the methods resulting in a rapid generation of production and inertial range energy content associated to microscales that is consistent with non-nested simulations using periodic boundary conditions. The cell perturbation approach, the simplest and most efficient of the best performing methods, was investigated further under neutral and stable conditions. Successful results were obtained in all the regimes, where satisfactory agreement of mean velocity, variances and turbulent fluxes, as well as velocity and temperature spectra, was achieved with reference non-nested simulations. In contrast, the non-perturbed LES solution exhibited important energy deficits associated to a delayed establishment of fully-developed turbulence. The cell perturbation method has negligible computational cost, significantly accelerates

  12. CCMC: Serving research and space weather communities with unique space weather services, innovative tools and resources

    NASA Astrophysics Data System (ADS)

    Zheng, Yihua; Kuznetsova, Maria M.; Pulkkinen, Antti; Maddox, Marlo

    2015-04-01

    With the addition of Space Weather Research Center (a sub-team within CCMC) in 2010 to address NASA’s own space weather needs, CCMC has become a unique entity that not only facilitates research through providing access to the state-of-the-art space science and space weather models, but also plays a critical role in providing unique space weather services to NASA robotic missions, developing innovative tools and transitioning research to operations via user feedback. With scientists, forecasters and software developers working together within one team, through close and direct connection with space weather customers and trusted relationship with model developers, CCMC is flexible, nimble and effective to meet customer needs. In this presentation, we highlight a few unique aspects of CCMC/SWRC’s space weather services, such as addressing space weather throughout the solar system, pushing the frontier of space weather forecasting via the ensemble approach, providing direct personnel and tool support for spacecraft anomaly resolution, prompting development of multi-purpose tools and knowledge bases, and educating and engaging the next generation of space weather scientists.

  13. Weather Information Communications (WINCOMM) Project: Dissemination of Weather Information for the Reduction of Aviation Weather-Related Accident Causal Factors

    NASA Technical Reports Server (NTRS)

    Jarrell, Michael; Tanger, Thomas

    2004-01-01

    Weather Information Communications (WINCOMM) is part of the Weather Accident Prevention (WxAP) Project, which is part of the NASA's Aviation Safety and Security Program. The goals of WINCOMM are to facilitate the exchange of tactical and strategic weather information between air and ground. This viewgraph presentation provides information on data link decision factors, architectures, validation goals. WINCOMM is capable of providing en-route communication air-to-ground, ground-to-air, and air-to-air, even on international or intercontinental flights. The presentation also includes information on the capacity, cost, and development of data links.

  14. The INAF/IAPS Plasma Chamber for ionospheric simulation experiment

    NASA Astrophysics Data System (ADS)

    Diego, Piero

    2016-04-01

    The plasma chamber is particularly suitable to perform studies for the following applications: - plasma compatibility and functional tests on payloads envisioned to operate in the ionosphere (e.g. sensors onboard satellites, exposed to the external plasma environment); - calibration/testing of plasma diagnostic sensors; - characterization and compatibility tests on components for space applications (e.g. optical elements, harness, satellite paints, photo-voltaic cells, etc.); - experiments on satellite charging in a space plasma environment; - tests on active experiments which use ion, electron or plasma sources (ion thrusters, hollow cathodes, field effect emitters, plasma contactors, etc.); - possible studies relevant to fundamental space plasma physics. The facility consists of a large volume vacuum tank (a cylinder of length 4.5 m and diameter 1.7 m) equipped with a Kaufman type plasma source, operating with Argon gas, capable to generate a plasma beam with parameters (i.e. density and electron temperature) close to the values encountered in the ionosphere at F layer altitudes. The plasma beam (A+ ions and electrons) is accelerated into the chamber at a velocity that reproduces the relative motion between an orbiting satellite and the ionosphere (≈ 8 km/s). This feature, in particular, allows laboratory simulations of the actual compression and depletion phenomena which take place in the ram and wake regions around satellites moving through the ionosphere. The reproduced plasma environment is monitored using Langmuir Probes (LP) and Retarding Potential Analyzers (RPA). These sensors can be automatically moved within the experimental space using a sled mechanism. Such a feature allows the acquisition of the plasma parameters all around the space payload installed into the chamber for testing. The facility is currently in use to test the payloads of CSES satellite (Chinese Seismic Electromagnetic Satellite) devoted to plasma parameters and electric field

  15. Comparison of Selected Weather Translation Products

    NASA Technical Reports Server (NTRS)

    Kulkarni, Deepak

    2017-01-01

    Weather is a primary contributor to the air traffic delays within the National Airspace System (NAS). At present, it is the individual decision makers who use weather information and assess its operational impact in creating effective air traffic management solutions. As a result, the estimation of the impact of forecast weather and the quality of ATM response relies on the skill and experience level of the decision maker. FAA Weather-ATM working groups have developed a Weather-ATM integration framework that consists of weather collection, weather translation, ATM impact conversion and ATM decision support. Some weather translation measures have been developed for hypothetical operations such as decentralized free flight, whereas others are meant to be relevant in current operations. This paper does comparative study of two different weather translation products relevant in current operations and finds that these products have strong correlation with each other. Given inaccuracies in prediction of weather, these differences would not be expected to be of significance in statistical study of a large number of decisions made with a look-ahead time of two hours or more.

  16. AWE: Aviation Weather Data Visualization Environment

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly; Lodha, Suresh K.

    2000-01-01

    The two official sources for aviation weather reports both provide weather information to a pilot in a textual format. A number of systems have recently become available to help pilots with the visualization task by providing much of the data graphically. However, two types of aviation weather data are still not being presented graphically. These are airport-specific current weather reports (known as meteorological observations, or METARs) and forecast weather reports (known as terminal area forecasts, or TAFs). Our system, Aviation Weather Environment (AWE), presents intuitive graphical displays for both METARs and TAFs, as well as winds aloft forecasts. We start with a computer-generated textual aviation weather briefing. We map this briefing onto a cartographic grid specific to the pilot's area of interest. The pilot is able to obtain aviation-specific weather for the entire area or for his specific route. The route, altitude, true airspeed, and proposed departure time can each be modified in AWE. Integral visual display of these three elements of weather reports makes AWE a useful planning tool, as well as a weather briefing tool.

  17. DECISION-MAKING SPARK CHAMBERS,

    DTIC Science & Technology

    of scattering of a particle and coplanarity of two particles. Decision - making spark chambers are used to trigger an optical spark chamber of two...the position of a spark and the separation of two sparks. Many other kinds of spatial decisions can be made with these devices such as the recognition

  18. SUMO Chamber Conditions

    DOE Data Explorer

    Sevanto, Sanna [Los Alamos National Laboratory; Powers, Heath [Los Alamos National Laboratory; Dickman, Turin L. [Los Alamos National Laboratory; Collins, Adam [Los Alamos National Laboratory; Grossiord, Charlotte [Swiss Federal Institute for Forest Snow and Landscape Research; Adams, Henry [Oklahoma State University; Borrego, Isaac [USGS Southwest Biological Science Center; McDowell, Nate [Pacific Northwest National Laboratory (PNNL); Stockton, Elizabeth [University of New Mexico; Ryan, Max [Los Alamos National Laboratory; Slentz, Matthew [Mohle Adams; Briggs, Sam [Fossil Creek Nursery; McBranch, Natalie [Los Alamos National Laboratory; Morgan, Bryn [Los Alamos National Laboratory

    2018-01-01

    The Los Alamos Survival–Mortality experiment (SUMO) is located on Frijoles Mesa near Los Alamos, New Mexico, USA, at an elevation of 2150 m. This was a tree manipulation study that investigated the relative impacts of drought and warming on plant function and reveals how trees adapt to drought and heat in semi-arid regions. The study factored the role of tree hydraulic acclimation to both precipitation and temperature and separated their effects.The experiment is located in a pinon-juniper woodland near the ponderosa pine (Pinus ponderosa) forest ecotone. Chamber conditions (temperature, relative humidity, vapor pressure deficit) for SUMO Open Top Chambers (OTCs) used to control air temperatures surrounding heated and control chamber trees. See SUMO Target Tree Information data package (doi:10.15485/1440544) for additional information. Data released by Los Alamos National Lab for public use under LA-UR-18-23656.

  19. Free-Flow Open-Chamber Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Free-flow open-chamber electrophoresis variant of free-flow electrophoresis performed in chamber with open ends and in which velocity of electro-osmotic flow adjusted equal to and opposite mean electrophoretic velocity of sample. Particles having electrophoretic mobilities greater than mean mobility of sample particles move toward cathode, those with mobilities less move toward anode. Technique applied to separation of components of mixtures of biologically important substances. Sensitivity enhanced by use of tapered chamber.

  20. Method for generating a plasma wave to accelerate electrons

    DOEpatents

    Umstadter, D.; Esarey, E.; Kim, J.K.

    1997-06-10

    The invention provides a method and apparatus for generating large amplitude nonlinear plasma waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the electron gun system, also called beam source, which preferably comprises photo cathode electron source and RF-LINAC accelerator; electron photo-cathode triggering system; the electron diagnostics; and the feedback system between the electron diagnostics and the laser system. The system also includes plasma source including vacuum chamber, magnetic lens, and magnetic field means. The laser system produces a train of pulses that has been optimized to maximize the axial electric field amplitude of the plasma wave, and thus the electron acceleration, using the method of the invention. 21 figs.

  1. Method for generating a plasma wave to accelerate electrons

    DOEpatents

    Umstadter, Donald; Esarey, Eric; Kim, Joon K.

    1997-01-01

    The invention provides a method and apparatus for generating large amplitude nonlinear plasma waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the electron gun system, also called beam source, which preferably comprises photo cathode electron source and RF-LINAC accelerator; electron photo-cathode triggering system; the electron diagnostics; and the feedback system between the electron diagnostics and the laser system. The system also includes plasma source including vacuum chamber, magnetic lens, and magnetic field means. The laser system produces a train of pulses that has been optimized to maximize the axial electric field amplitude of the plasma wave, and thus the electron acceleration, using the method of the invention.

  2. Mountain ranges, climate and weathering. Do orogens strengthen or weaken the silicate weathering carbon sink?

    NASA Astrophysics Data System (ADS)

    Maffre, Pierre; Ladant, Jean-Baptiste; Moquet, Jean-Sébastien; Carretier, Sébastien; Labat, David; Goddéris, Yves

    2018-07-01

    The role of mountains in the geological evolution of the carbon cycle has been intensively debated for the last decades. Mountains are thought to increase the local physical erosion, which in turns promotes silicate weathering, organic carbon transport and burial, and release of sulfuric acid by dissolution of sulfides. In this contribution, we explore the impact of mountain ranges on silicate weathering. Mountains modify the global pattern of atmospheric circulation as well as the local erosion conditions. Using an IPCC-class climate model, we first estimate the climatic impact of mountains by comparing the present day climate with the climate when all the continents are assumed to be flat. We then use these climate output to calculate weathering changes when mountains are present or absent, using standard expression for physical erosion and a 1D vertical model for rock weathering. We found that large-scale climate changes and enhanced rock supply by erosion due to mountain uplift have opposite effect, with similar orders of magnitude. A thorough testing of the weathering model parameters by data-model comparison shows that best-fit parameterizations lead to a decrease of weathering rate in the absence of mountain by about 20%. However, we demonstrate that solutions predicting an increase in weathering in the absence of mountain cannot be excluded. A clear discrimination between the solutions predicting an increase or a decrease in global weathering is pending on the improvement of the existing global databases for silicate weathering. Nevertheless, imposing a constant and homogeneous erosion rate for models without relief, we found that weathering decrease becomes unequivocal for very low erosion rates (below 10 t/km2/yr). We conclude that further monitoring of continental silicate weathering should be performed with a spatial distribution allowing to discriminate between the various continental landscapes (mountains, plains …).

  3. CubeSat: Colorado Student Space Weather Experiment

    NASA Astrophysics Data System (ADS)

    Li, X.; Palo, S. E.; Turner, D. L.; Gerhardt, D.; Redick, T.; Tao, J.

    2009-12-01

    Energetic particles, electrons and protons either directly associated with solar flares or trapped in the terrestrial radiation belt, have a profound space weather impact. A 3U CubeSat mission with a single instrument, Relativistic Electrons and Proton Telescope integrated little experiment (REPTile), is proposed to address fundamental questions relating to the relationship between solar flares and energetic particles and the acceleration and loss mechanism of outer radiation belt electrons. REPTile, in a highly inclined low earth orbit, will measure differential fluxes of relativistic electrons in the energy range of 0.5-3.5 MeV and protons in 10-40 MeV. This project is a collaborative effort between the Laboratory for Atmospheric and Space Physics and the Department of Aerospace Engineering Sciences at the University of Colorado, which includes the integration of students, faculty, and professional engineers.

  4. Convection Weather Detection by General Aviation Pilots with Convectional and Data-Linked Graphical Weather Information Sources

    NASA Technical Reports Server (NTRS)

    Chamberlain, James P.; Latorella, Kara A.

    2001-01-01

    This study compares how well general aviation (GA) pilots detect convective weather in flight with different weather information sources. A flight test was conducted in which GA pilot test subjects were given different in-flight weather information cues and flown toward convective weather of moderate or greater intensity. The test subjects were not actually flying the aircraft, but were given pilot tasks representative of the workload and position awareness requirements of the en route portion of a cross country GA flight. On each flight, one test subject received weather cues typical of a flight in visual meteorological conditions (VMC), another received cues typical of flight in instrument meteorological conditions (IMC), and a third received cues typical of flight in IMC but augmented with a graphical weather information system (GWIS). The GWIS provided the subject with near real time data-linked weather products, including a weather radar mosaic superimposed on a moving map with a symbol depicting the aircraft's present position and direction of track. At several points during each flight, the test subjects completed short questionnaires which included items addressing their weather situation awareness and flight decisions. In particular, test subjects were asked to identify the location of the nearest convective cells. After the point of nearest approach to convective weather, the test subjects were asked to draw the location of convective weather on an aeronautical chart, along with the aircraft's present position. This paper reports preliminary results on how accurately test subjects provided with these different weather sources could identify the nearest cell of moderate or greater intensity along their route of flight. Additional flight tests are currently being conducted to complete the data set.

  5. Demonstration of improved sensitivity of echo interferometers to gravitational acceleration

    NASA Astrophysics Data System (ADS)

    Mok, C.; Barrett, B.; Carew, A.; Berthiaume, R.; Beattie, S.; Kumarakrishnan, A.

    2013-08-01

    We have developed two configurations of an echo interferometer that rely on standing-wave excitation of a laser-cooled sample of rubidium atoms. Both configurations can be used to measure acceleration a along the axis of excitation. For a two-pulse configuration, the signal from the interferometer is modulated at the recoil frequency and exhibits a sinusoidal frequency chirp as a function of pulse spacing. In comparison, for a three-pulse stimulated-echo configuration, the signal is observed without recoil modulation and exhibits a modulation at a single frequency as a function of pulse spacing. The three-pulse configuration is less sensitive to effects of vibrations and magnetic field curvature, leading to a longer experimental time scale. For both configurations of the atom interferometer (AI), we show that a measurement of acceleration with a statistical precision of 0.5% can be realized by analyzing the shape of the echo envelope that has a temporal duration of a few microseconds. Using the two-pulse AI, we obtain measurements of acceleration that are statistically precise to 6 parts per million (ppm) on a 25 ms time scale. In comparison, using the three-pulse AI, we obtain measurements of acceleration that are statistically precise to 0.4 ppm on a time scale of 50 ms. A further statistical enhancement is achieved by analyzing the data across the echo envelope so that the statistical error is reduced to 75 parts per billion (ppb). The inhomogeneous field of a magnetized vacuum chamber limited the experimental time scale and resulted in prominent systematic effects. Extended time scales and improved signal-to-noise ratio observed in recent echo experiments using a nonmagnetic vacuum chamber suggest that echo techniques are suitable for a high-precision measurement of gravitational acceleration g. We discuss methods for reducing systematic effects and improving the signal-to-noise ratio. Simulations of both AI configurations with a time scale of 300 ms suggest

  6. Aviation Weather Information Requirements Study

    NASA Technical Reports Server (NTRS)

    Keel, Byron M.; Stancil, Charles E.; Eckert, Clifford A.; Brown, Susan M.; Gimmestad, Gary G.; Richards, Mark A.; Schaffner, Philip R. (Technical Monitor)

    2000-01-01

    The Aviation Safety Program (AvSP) has as its goal an improvement in aviation safety by a factor of 5 over the next 10 years and a factor of 10 over the next 20 years. Since weather has a big impact on aviation safety and is associated with 30% of all aviation accidents, Weather Accident Prevention (WxAP) is a major element under this program. The Aviation Weather Information (AWIN) Distribution and Presentation project is one of three projects under this element. This report contains the findings of a study conducted by the Georgia Tech Research Institute (GTRI) under the Enhanced Weather Products effort, which is a task under AWIN. The study examines current aviation weather products and there application. The study goes on to identify deficiencies in the current system and to define requirements for aviation weather products that would lead to an increase in safety. The study also provides an overview the current set of sensors applied to the collection of aviation weather information. New, modified, or fused sensor systems are identified which could be applied in improving the current set of weather products and in addressing the deficiencies defined in the report. In addition, the study addresses and recommends possible sensors for inclusion in an electronic pilot reporting (EPIREP) system.

  7. Integration of Weather Avoidance and Traffic Separation

    NASA Technical Reports Server (NTRS)

    Consiglio, Maria C.; Chamberlain, James P.; Wilson, Sara R.

    2011-01-01

    This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

  8. A soundproof pressure chamber.

    PubMed

    Kitahara, M; Kodama, A; Ozawa, H; Inoue, S

    1994-01-01

    For neurotological research we designed a soundproof pressure chamber in which pressure can be adjusted +/- 1000 mmH2O at the rate of less than 100 mmH2O per second. Noise in the chamber can be maintained under 30-35 dB while pressure is kept at a given level.

  9. Space Weathering of Lunar Rocks

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2012-01-01

    All materials exposed at the lunar surface undergo space weathering processes. On the Moon, boulders make up only a small percentage of the exposed surface, and areas where such rocks are exposed, like central peaks, are often among the least space weathered regions identified from remote sensing data. Yet space weathered surfaces (patina) are relatively common on returned rock samples, some of which directly sample the surface of larger boulders. Because, as witness plates to lunar space weathering, rocks and boulders experience longer exposure times compared to lunar soil grains, they allow us to develop a deeper perspective on the relative importance of various weathering processes as a function of time.

  10. Vacuum Plasma Spray Forming of Tungsten Lorentz Force Accelerator Components

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank R.

    2004-01-01

    The Vacuum Plasma Spray (VPS) Laboratory at NASA's Marshall Space Flight Center, working with the Jet Propulsion Laboratory, has developed and demonstrated a fabrication technique using the VPS process to form anode and cathode sections for a Lorentz force accelerator made from tungsten. Lorentz force accelerators are an attractive form of electric propulsion that provides continuous, high-efficiency propulsion at useful power levels for such applications as orbit transfers or deep space missions. The VPS process is used to deposit refractory metals such as tungsten onto a graphite mandrel of the desired shape. Because tungsten is reactive at high temperatures, it is thermally sprayed in an inert environment where the plasma gun melts and deposits the molten metal powder onto a mandrel. A three-axis robot inside the chamber controls the motion of the plasma spray torch. A graphite mandrel acts as a male mold, forming the required contour and dimensions for the inside surface of the anode or cathode of the accelerator. This paper describes the processing techniques, design considerations, and process development associated with the VPS forming of Lorentz force accelerator components.

  11. Fabulous Weather Day

    ERIC Educational Resources Information Center

    Marshall, Candice; Mogil, H. Michael

    2007-01-01

    Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

  12. Seasonal Forecasting of Fire Weather Based on a New Global Fire Weather Database

    NASA Technical Reports Server (NTRS)

    Dowdy, Andrew J.; Field, Robert D.; Spessa, Allan C.

    2016-01-01

    Seasonal forecasting of fire weather is examined based on a recently produced global database of the Fire Weather Index (FWI) system beginning in 1980. Seasonal average values of the FWI are examined in relation to measures of the El Nino-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). The results are used to examine seasonal forecasts of fire weather conditions throughout the world.

  13. EPA GAS PHASE CHEMISTRY CHAMBER STUDIES

    EPA Science Inventory

    Gas-phase smog chamber experiments are being performed at EPA in order to evaluate a number of current chemical mechanisms for inclusion in EPA regulatory and research models. The smog chambers are 9000 L in volume and constructed of 2-mil teflon film. One of the chambers is co...

  14. Incremental laser space weathering of Allende reveals non-lunar like space weathering effects

    NASA Astrophysics Data System (ADS)

    Gillis-Davis, Jeffrey J.; Lucey, Paul G.; Bradley, John P.; Ishii, Hope A.; Kaluna, Heather M.; Misra, Anumpam; Connolly, Harold C.

    2017-04-01

    We report findings from a series of laser-simulated space weathering experiments on Allende, a CV3 carbonaceous chondrite. The purpose of these experiments is to understand how spectra of anhydrous C-complex asteroids might vary as a function of micrometeorite bombardment. Four 0.5-gram aliquots of powdered, unpacked Allende meteorite were incrementally laser weathered with 30 mJ pulses while under vacuum. Radiative transfer modeling of the spectra and Scanning Transmission Electron Microscope (STEM) analyses of the samples show lunar-like similarities and differences in response to laser-simulated space weathering. For instance, laser weathered Allende exhibited lunar-like spectral changes. The overall spectra from visible to near infrared (Vis-NIR) redden and darken, and characteristic absorption bands weaken as a function of laser exposure. Unlike lunar weathering, however, the continuum slope between 450-550 nm does not vary monotonically with laser irradiation. Initially, spectra in this region redden with laser irradiation; then, the visible continua become less red and eventually spectrally bluer. STEM analyses of less mature samples confirm submicroscopic iron metal (SMFe) and micron sized sulfides. More mature samples reveal increased dispersal of Fe-Ni sulfides by the laser, which we infer to be the cause for the non-lunar-like changes in spectral behavior. Spectra of laser weathered Allende are a reasonable match to T- or possibly K-type asteroids; though the spectral match with a parent body is not exact. The key take away is, laser weathered Allende looks spectrally different (i.e., darker, and redder or bluer depending on the wavelength region) than its unweathered spectrum. Consequently, connecting meteorites to asteroids using unweathered spectra of meteorites would result in a different parent body than one matched on the basis of weathered spectra. Further, spectra for these laser weathering experiments may provide an explanation for

  15. The Impact of Organo-Mineral Complexation on Mineral Weathering in the Soil Zone under Unsaturated Conditions

    NASA Astrophysics Data System (ADS)

    Michael, H. A.; Tan, F.; Yoo, K.; Imhoff, P. T.

    2017-12-01

    While organo-mineral complexes can protect organic matter (OM) from biodegradation, their impact on soil mineral weathering is not clear. Previous bench-scale experiments that focused on specific OM and minerals showed that the adsorption of OM to mineral surfaces accelerates the dissolution of some minerals. However, the impact of natural organo-mineral complexes on mineral dissolution under unsaturated conditions is not well known. In this study, soil samples prepared from an undisturbed forest site were used to determine mineral weathering rates under differing conditions of OM sorption to minerals. Two types of soil samples were generated: 1) soil with OM (C horizon soil from 84-100cm depth), and 2) soil without OM (the same soil as in 1) but with OM removed by heating to 350°for 24 h). Soil samples were column-packed and subjected to intermittent infiltration and drainage to mimic natural rainfall events. Each soil sample type was run in duplicate. The unsaturated condition was created by applying gas pressure to the column, and the unsaturated chemical weathering rates during each cycle were calculated from the effluent concentrations. During a single cycle, when applying the same gas pressure, soils with OM retained more moisture than OM-removed media, indicating increased water retention capacity under the impact of OM. This is consistent with the water retention data measured by evaporation experiments (HYPROP) and the dew point method (WP4C Potential Meter). Correspondingly, silicon (Si) denudation rates indicated that dissolution of silicate minerals was 2-4 times higher in OM soils, suggesting that organo-mineral complexes accelerate mineral dissolution under unsaturated conditions. When combining data from all cycles, the results showed that Si denudation rates were positively related to soil water content: denundation rate increased with increasing water content. Therefore, natural mineral chemical weathering under unsaturated conditions, while

  16. Alaska Native Weatherization Training and Jobs Program First Steps Toward Tribal Weatherization – Human Capacity Development

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

    Wiita, Joanne

    The Alaska Native Weatherization Training and Jobs Project expanded weatherization services for tribal members’ homes in southeast Alaska while providing weatherization training and on the job training (OJT) for tribal citizens that lead to jobs and most probably careers in weatherization-related occupations. The program resulted in; (a) 80 Alaska Native citizens provided with skills training in five weatherization training units that were delivered in cooperation with University of Alaska Southeast, in accordance with the U.S. Department of Energy Core Competencies for Weatherization Training that prepared participants for employment in three weatherizationrelated occupations: Installer, Crew Chief, and Auditor; (b) 25 paidmore » OJT training opportunities for trainees who successfully completed the training course; and (c) employed trained personnel that have begun to rehab on over 1,000 housing units for weatherization.« less

  17. The New Space Weather Action Center; the Next Level on Space Weather Education

    NASA Astrophysics Data System (ADS)

    Collado-Vega, Y. M.; Lewis, E. M.; Cline, T. D.; MacDonald, E.

    2016-12-01

    The Space Weather Action Center (SWAC) provides access for students to near real-time space weather data, and a set of easy instructions and well-defined protocols that allow them to correctly interpret such data. It is a student centered approach to teaching science and technology in classrooms, as students are encouraged to act like real scientists by accessing, collecting, analyzing, recording, and communicating space weather forecasts. Integration and implementation of several programs will enhance and provide a rich education experience for students' grades 5-16. We will enhance the existing data and tutorials available using the Integrated Space Weather Analysis (iSWA) tool created by the Community Coordinated Modeling Center (CCMC) at NASA GSFC. iSWA is a flexible, turn-key, customer-configurable, Web-based dissemination system for NASA-relevant space weather information that combines data based on the most advanced space weather models available through the CCMC with concurrent space environment information. This tool provides an additional component by the use of videos and still imagery from different sources as a tool for educators to effectively show what happens during an eruption from the surface of the Sun. We will also update content on the net result of space weather forecasting that the public can experience by including Aurorasaurus, a well established, growing, modern, innovative, interdisciplinary citizen science project centered around the public's visibility of the northern lights with mobile applications via the use of social media connections.

  18. Guidelines for disseminating road weather messages : improved road weather information for travelers.

    DOT National Transportation Integrated Search

    2013-01-01

    The Federal Highway Administration (FHWA) Road Weather Management Program (RWMP) recently published a document titled Guidelines for Disseminating Road Weather Advisory and Control Information (FHWA-JPO-12- 046). The guidelines are intended for use b...

  19. Training Early Career Space Weather Researchers and other Space Weather Professionals at the CISM Space Weather Summer School

    NASA Astrophysics Data System (ADS)

    Gross, N. A.; Hughes, W.

    2011-12-01

    This talk will outline the organization of a summer school designed to introduce young professions to a sub-discipline of geophysics. Through out the 10 year life time of the Center for Integrated Space Weather Modeling (CISM) the CISM Team has offered a two week summer school that introduces new graduate students and other interested professional to the fundamentals of space weather. The curriculum covers basic concepts in space physics, the hazards of space weather, and the utility of computer models of the space environment. Graduate students attend from both inside and outside CISM, from all the sub-disciplines involved in space weather (solar, heliosphere, geomagnetic, and aeronomy), and from across the nation and around the world. In addition, between 1/4 and 1/3 of the participants each year are professionals involved in space weather in some way, such as: forecasters from NOAA and the Air Force, Air Force satellite program directors, NASA specialists involved in astronaut radiation safety, and representatives from industries affected by space weather. The summer school has adopted modern pedagogy that has been used successfully at the undergraduate level. A typical daily schedule involves three morning lectures followed by an afternoon lab session. During the morning lectures, student interaction is encouraged using "Timeout to Think" questions and peer instruction, along with question cards for students to ask follow up questions. During the afternoon labs students, working in groups of four, answer thought provoking questions using results from simulations and observation data from a variety of source. Through the interactions with each other and the instructors, as well as social interactions during the two weeks, students network and form bonds that will last them through out their careers. We believe that this summer school can be used as a model for summer schools in a wide variety of disciplines.

  20. Home Weatherization Visit

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

    Chu, Steven; Strickland, Ted

    2009-08-25

    Secretary Steven Chu visits a home that is in the process of being weatherized in Columbus, OH, along with Ohio Governor Ted Strickland and Columbus Mayor Michael Coleman. They discuss the benefits of weatherization and how funding from the recovery act is having a direct impact in communities across America.

  1. Home Weatherization Visit

    ScienceCinema

    Chu, Steven; Strickland, Ted

    2018-02-14

    Secretary Steven Chu visits a home that is in the process of being weatherized in Columbus, OH, along with Ohio Governor Ted Strickland and Columbus Mayor Michael Coleman. They discuss the benefits of weatherization and how funding from the recovery act is having a direct impact in communities across America.

  2. Forecasting Space Weather Events for a Neighboring World

    NASA Technical Reports Server (NTRS)

    Zheng, Yihua; Mason, Tom; Wood, Erin L.

    2015-01-01

    Shortly after NASA's Mars Atmosphere and Volatile EvolutioN mission (MAVEN) spacecraft entered Mars' orbit on 21 September 2014, scientists glimpsed the Martian atmosphere's response to a front of solar energetic particles (SEPs) and an associated coronal mass ejection (CME). In response to some solar flares and CMEs, streams of SEPs burst from the solar atmosphere and are further accelerated in the interplanetary medium between the Sun and the planets. These particles deposit their energy and momentum into anything in their path, including the Martian atmosphere and MAVEN particle detectors. MAVEN scientists had been alerted to the likely CME-Mars encounter by a space weather prediction system that had its origins in space weather forecasting for Earth but now forecasts space weather for Earth's neighboring planets. The two Solar Terrestrial Relations Observatory spacecraft and Solar Heliospheric Observatory observed a CME on 26 September, with a trajectory that suggested a Mars intercept. A computer model developed for solar wind prediction, the Wang-Sheeley-Arge-Enlil cone model [e.g., Zheng et al., 2013; Parsons et al., 2011], running in real time at the Community Coordinated Modeling Center (CCMC) located at NASA Goddard since 2006, showed the CME propagating in the direction of Mars (Figure 1). According to MAVEN particle detectors, the disturbance and accompanying SEP enhancement at the leading edge of the CME reached Mars at approximately 17 hours Universal Time on 29 September 2014. Such SEPs may have a profound effect on atmospheric escape - they are believed to be a possible means for driving atmospheric loss. SEPs can cause loss of Mars' upper atmosphere through several loss mechanisms including sputtering of the atmosphere. Sputtering occurs when atoms are ejected from the atmosphere due to impacts with energetic particles.

  3. Weather Forecasting Systems and Methods

    NASA Technical Reports Server (NTRS)

    Mecikalski, John (Inventor); MacKenzie, Wayne M., Jr. (Inventor); Walker, John Robert (Inventor)

    2014-01-01

    A weather forecasting system has weather forecasting logic that receives raw image data from a satellite. The raw image data has values indicative of light and radiance data from the Earth as measured by the satellite, and the weather forecasting logic processes such data to identify cumulus clouds within the satellite images. For each identified cumulus cloud, the weather forecasting logic applies interest field tests to determine a score indicating the likelihood of the cumulus cloud forming precipitation and/or lightning in the future within a certain time period. Based on such scores, the weather forecasting logic predicts in which geographic regions the identified cumulus clouds will produce precipitation and/or lighting within during the time period. Such predictions may then be used to provide a weather map thereby providing users with a graphical illustration of the areas predicted to be affected by precipitation within the time period.

  4. Hydrostatic Level Sensors as High Precision Ground Motion Instrumentation for Tevatron and Other Energy Frontier Accelerators

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

    Volk, James; Hansen, Sten; Johnson, Todd

    2012-01-01

    Particle accelerators require very tight tolerances on the alignment and stability of their elements: magnets, accelerating cavities, vacuum chambers, etc. In this article we describe the Hydrostatic Level Sensors (HLS) for very low frequency measurements used in a variety of facilities at Fermilab. We present design features of the sensors, outline their technical parameters, describe their test and calibration procedures, discuss different regimes of operation and give few illustrative examples of the experimental data. Detail experimental results of the ground motion measurements with these detectors will be presented in subsequent papers.

  5. Rock-weathering rates as functions of time

    USGS Publications Warehouse

    Colman, Steven M.

    1981-01-01

    The scarcity of documented numerical relations between rock weathering and time has led to a common assumption that rates of weathering are linear. This assumption has been strengthened by studies that have calculated long-term average rates. However, little theoretical or empirical evidence exists to support linear rates for most chemical-weathering processes, with the exception of congruent dissolution processes. The few previous studies of rock-weathering rates that contain quantitative documentation of the relation between chemical weathering and time suggest that the rates of most weathering processes decrease with time. Recent studies of weathering rinds on basaltic and andesitic stones in glacial deposits in the western United States also clearly demonstrate that rock-weathering processes slow with time. Some weathering processes appear to conform to exponential functions of time, such as the square-root time function for hydration of volcanic glass, which conforms to the theoretical predictions of diffusion kinetics. However, weathering of mineralogically heterogeneous rocks involves complex physical and chemical processes that generally can be expressed only empirically, commonly by way of logarithmic time functions. Incongruent dissolution and other weathering processes produce residues, which are commonly used as measures of weathering. These residues appear to slow movement of water to unaltered material and impede chemical transport away from it. If weathering residues impede weathering processes then rates of weathering and rates of residue production are inversely proportional to some function of the residue thickness. This results in simple mathematical analogs for weathering that imply nonlinear time functions. The rate of weathering becomes constant only when an equilibrium thickness of the residue is reached. Because weathering residues are relatively stable chemically, and because physical removal of residues below the ground surface is slight

  6. Graphical tools for TV weather presentation

    NASA Astrophysics Data System (ADS)

    Najman, M.

    2010-09-01

    Contemporary meteorology and its media presentation faces in my opinion following key tasks: - Delivering the meteorological information to the end user/spectator in understandable and modern fashion, which follows industry standard of video output (HD, 16:9) - Besides weather icons show also the outputs of numerical weather prediction models, climatological data, satellite and radar images, observed weather as actual as possible. - Does not compromise the accuracy of presented data. - Ability to prepare and adjust the weather show according to actual synoptic situtation. - Ability to refocus and completely adjust the weather show to actual extreme weather events. - Ground map resolution weather data presentation need to be at least 20 m/pixel to be able to follow the numerical weather prediction model resolution. - Ability to switch between different numerical weather prediction models each day, each show or even in the middle of one weather show. - The graphical weather software need to be flexible and fast. The graphical changes nee to be implementable and airable within minutes before the show or even live. These tasks are so demanding and the usual original approach of custom graphics could not deal with it. It was not able to change the show every day, the shows were static and identical day after day. To change the content of the weather show daily was costly and most of the time impossible with the usual approach. The development in this area is fast though and there are several different options for weather predicting organisations such as national meteorological offices and private meteorological companies to solve this problem. What are the ways to solve it? What are the limitations and advantages of contemporary graphical tools for meteorologists? All these questions will be answered.

  7. The scientific challenges to forecasting the propagation of space weather through the heliosphere (Invited)

    NASA Astrophysics Data System (ADS)

    van der Holst, B.; Manchester, W.; Sokolov, I.; Toth, G.; Gombosi, T. I.

    2013-12-01

    Coronal mass ejections (CMEs) are a major source of potentially destructive space weather conditions. Understanding and forecasting these events are of utmost importance. In this presentation we discuss the progress towards a physics-based predictive capability within the Space Weather Modeling Framework (SWMF). We demonstrate our latest development in the AWSoM (Alfven Wave Solar Model) global model of the solar corona and inner heliosphere. This model accounts for the coupled thermodynamics of the electrons and protons via single fluid magnetohydrodynamics. The coronal heating and solar wind acceleration are addressed with Alfvén wave turbulence. The realistic 3D magnetic field is simulated using data from the photospheric magnetic field measurements. The AWSoM model serves as a workhorse for modeling CMEs from initial eruption to prediction at 1AU. With selected events we will demonstrate the complexity and challenges associated with CME propagation.

  8. Food Safety for Warmer Weather

    MedlinePlus

    ... Fight Off Food Poisoning Food Safety for Warmer Weather En español Send us your comments In warm-weather months, who doesn’t love to get outside ... to keep foods safe to eat during warmer weather. If you’re eating or preparing foods outside, ...

  9. Space Weather: The Solar Perspective

    NASA Astrophysics Data System (ADS)

    Schwenn, Rainer

    2006-08-01

    The term space weather refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and that can affect human life and health. Our modern hi-tech society has become increasingly vulnerable to disturbances from outside the Earth system, in particular to those initiated by explosive events on the Sun: Flares release flashes of radiation that can heat up the terrestrial atmosphere such that satellites are slowed down and drop into lower orbits, solar energetic particles accelerated to near-relativistic energies may endanger astronauts traveling through interplanetary space, and coronal mass ejections are gigantic clouds of ionized gas ejected into interplanetary space that after a few hours or days may hit the Earth and cause geomagnetic storms. In this review, I describe the several chains of actions originating in our parent star, the Sun, that affect Earth, with particular attention to the solar phenomena and the subsequent effects in interplanetary space.

  10. Road weather information for travelers : improving road weather messages and dissemination methods.

    DOT National Transportation Integrated Search

    2010-01-01

    The Federal Highway Administration (FHWA) Road Weather Management Program (RWMP) recently completed a study titled Human Factors Analysis of Road Weather Advisory and Control Information (Publication No. FHWAJPO- 10-053). The goal of the study was to...

  11. NOAA WEATHER SATELLITES

    Science.gov Websites

    extent of snow cover. In addition, satellite sensors detect ice fields and map the movement of sea and greater danger near shore or any shallow waters? NATIONAL WEATHER SERVICE SATELLITE PRODUCTS NOAA's operational weather satellite system is composed of two types of satellites: geostationary operational

  12. Pilot's Automated Weather Support System (PAWSS) concepts demonstration project. Phase 1: Pilot's weather information requirements and implications for weather data systems design

    NASA Technical Reports Server (NTRS)

    Crabill, Norman L.; Dash, Ernie R.

    1991-01-01

    The weather information requirements for pilots and the deficiencies of the current aviation weather support system in meeting these requirements are defined. As the amount of data available to pilots increases significantly in the near future, expert system technology will be needed to assist pilots in assimilating that information. Some other desirable characteristics of an automation-assisted system for weather data acquisition, dissemination, and assimilation are also described.

  13. Compact ion chamber based neutron detector

    DOEpatents

    Derzon, Mark S.; Galambos, Paul C.; Renzi, Ronald F.

    2015-10-27

    A directional neutron detector has an ion chamber formed in a dielectric material; a signal electrode and a ground electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; readout circuitry which is electrically coupled to the signal and ground electrodes; and a signal processor electrically coupled to the readout circuitry. The ion chamber has a pair of substantially planar electrode surfaces. The chamber pressure of the neutron absorbing material is selected such that the reaction particle ion trail length for neutrons absorbed by the neutron absorbing material is equal to or less than the distance between the electrode surfaces. The signal processor is adapted to determine a path angle for each absorbed neutron based on the rise time of the corresponding pulse in a time-varying detector signal.

  14. Anechoic chamber qualification at ultrasonic frequencies

    NASA Astrophysics Data System (ADS)

    Jenny, Trevor; Anderson, Brian

    2010-10-01

    Qualifying an anechoic chamber for frequencies that extend into the ultrasonic range is necessary for research work involving airborne ultrasonic sound. For example, an anechoic chamber allows for measurements of the direct sound radiated by an object without reflections from walls. The ANSI S12.55/ISO 3745 standard which covers anechoic chamber qualification does not extend into the ultrasonic frequency range, nor have others discussed this frequency range in the literature. An increasing number of technologies are employing ultrasound; hence the need to develop facilities to conduct basic research studies on airborne ultrasound. This presentation will discuss the challenges associated with chamber qualification and present the results for qualification of a chamber at Brigham Young University. [This work has been funded by the Los Alamos National Laboratory

  15. AMS-02 as a Space Weather Observatory

    NASA Astrophysics Data System (ADS)

    Whitman, K.; Bindi, V.; Chati, M.; Consolandi, C.; Corti, C.

    2013-12-01

    The Alpha Magnetic Spectrometer (AMS-02) is a state-of-the-art space detector that measures particles in the energy range of hundreds of MeV to a few TeV. AMS-02 has been installed onboard of the International Space Station (ISS) since May 2011 where it will operate for the duration of the station. To date, there is an abundance of space-based solar data collected in the low energy regimes, whereas there are very few direct measurements of higher energy particles available. AMS-02 is capable of measuring arrival time and composition of the highest energy SEPs in space. It is crucial to build a better knowledge base regarding the most energetic and potentially harmful events. We are currently developing a program to employ AMS-02 as a real-time space weather observatory. SEPs with higher energies are usually accelerated during a short period of time and they are the first particles to reach the Earth. AMS-02, measuring these highest energy SEPs, can alert the onset of an SEP event. During the past two years of operation, we have identified two main quantities in AMS-02 that are particularly sensitive to the arrival of SEPs: the detector livetime and the transition radiation detector (TRD) event size. By monitoring the detector livetime and the TRD event size, AMS-02 can pinpoint in real-time the arrival of SEPs inside the Earth's magnetosphere operating as a space weather detector.

  16. Preparing for Operational Use of High Priority Products from the Joint Polar Satellite System (JPSS) in Numerical Weather Prediction

    NASA Astrophysics Data System (ADS)

    Nandi, S.; Layns, A. L.; Goldberg, M.; Gambacorta, A.; Ling, Y.; Collard, A.; Grumbine, R. W.; Sapper, J.; Ignatov, A.; Yoe, J. G.

    2017-12-01

    This work describes end to end operational implementation of high priority products from National Oceanic and Atmospheric Administration's (NOAA) operational polar-orbiting satellite constellation, to include Suomi National Polar-orbiting Partnership (S-NPP) and the Joint Polar Satellite System series initial satellite (JPSS-1), into numerical weather prediction and earth systems models. Development and evaluation needed for the initial implementations of VIIRS Environmental Data Records (EDR) for Sea Surface Temperature ingestion in the Real-Time Global Sea Surface Temperature Analysis (RTG) and Polar Winds assimilated in the National Weather Service (NWS) Global Forecast System (GFS) is presented. These implementations ensure continuity of data in these models in the event of loss of legacy sensor data. Also discussed is accelerated operational implementation of Advanced Technology Microwave Sounder (ATMS) Temperature Data Records (TDR) and Cross-track Infrared Sounder (CrIS) Sensor Data Records, identified as Key Performance Parameters by the National Weather Service. Operational use of SNPP after 28 October, 2011 launch took more than one year due to the learning curve and development needed for full exploitation of new remote sensing capabilities. Today, ATMS and CrIS data positively impact weather forecast accuracy. For NOAA's JPSS initial satellite (JPSS-1), scheduled for launch in late 2017, we identify scope and timelines for pre-launch and post-launch activities needed to efficiently transition these capabilities into operations. As part of these alignment efforts, operational readiness for KPPs will be possible as soon as 90 days after launch. The schedule acceleration is possible because of the experience with S-NPP. NOAA operational polar-orbiting satellite constellation provides continuity and enhancement of earth systems observations out to 2036. Program best practices and lessons learned will inform future implementation for follow-on JPSS-3 and -4

  17. The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.

    PubMed

    Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

    2015-09-01

    On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  18. Weather forecasting expert system study

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Weather forecasting is critical to both the Space Transportation System (STS) ground operations and the launch/landing activities at NASA Kennedy Space Center (KSC). The current launch frequency places significant demands on the USAF weather forecasters at the Cape Canaveral Forecasting Facility (CCFF), who currently provide the weather forecasting for all STS operations. As launch frequency increases, KSC's weather forecasting problems will be great magnified. The single most important problem is the shortage of highly skilled forecasting personnel. The development of forecasting expertise is difficult and requires several years of experience. Frequent personnel changes within the forecasting staff jeopardize the accumulation and retention of experience-based weather forecasting expertise. The primary purpose of this project was to assess the feasibility of using Artificial Intelligence (AI) techniques to ameliorate this shortage of experts by capturing aria incorporating the forecasting knowledge of current expert forecasters into a Weather Forecasting Expert System (WFES) which would then be made available to less experienced duty forecasters.

  19. Space Weather Effects in the Earth's Radiation Belts

    NASA Astrophysics Data System (ADS)

    Baker, D. N.; Erickson, P. J.; Fennell, J. F.; Foster, J. C.; Jaynes, A. N.; Verronen, P. T.

    2018-02-01

    The first major scientific discovery of the Space Age was that the Earth is enshrouded in toroids, or belts, of very high-energy magnetically trapped charged particles. Early observations of the radiation environment clearly indicated that the Van Allen belts could be delineated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. The energy distribution, spatial extent and particle species makeup of the Van Allen belts has been subsequently explored by several space missions. Recent observations by the NASA dual-spacecraft Van Allen Probes mission have revealed many novel properties of the radiation belts, especially for electrons at highly relativistic and ultra-relativistic kinetic energies. In this review we summarize the space weather impacts of the radiation belts. We demonstrate that many remarkable features of energetic particle changes are driven by strong solar and solar wind forcings. Recent comprehensive data show broadly and in many ways how high energy particles are accelerated, transported, and lost in the magnetosphere due to interplanetary shock wave interactions, coronal mass ejection impacts, and high-speed solar wind streams. We also discuss how radiation belt particles are intimately tied to other parts of the geospace system through atmosphere, ionosphere, and plasmasphere coupling. The new data have in many ways rewritten the textbooks about the radiation belts as a key space weather threat to human technological systems.

  20. Early Wuchiapingian cooling linked to Emeishan basaltic weathering?

    NASA Astrophysics Data System (ADS)

    Yang, Jianghai; Cawood, Peter A.; Du, Yuansheng; Condon, Daniel J.; Yan, Jiaxin; Liu, Jianzhong; Huang, Yan; Yuan, Dongxun

    2018-06-01

    The last glaciation during the late Paleozoic ice age commenced at around the Guadalupian-Lopingian (G-L) boundary and is synchronous with the emplacement of the Emeishan large igneous province. Using CA-TIMS zircon U-Pb dating, we obtained an age of 259.51 ± 0.21 Ma for the uppermost tuff from the Puan volcanic sequence in the eastern Emeishan large igneous province, constraining the timing of Emeishan volcanism and providing another candidate age for the G-L boundary. In addition, we determined an age of 259.69 ± 0.72 Ma for a basal claystone in the immediately overlying Longtan Formation from a drill core section in southwest South China. These ages, along with source weathering trends of mudstones from the lower Longtan Formation, and compiled paleotemperature records, indicate an earliest Wuchiapingian cooling coinciding with the onset of the last Permian glaciation. This global cooling is associated with positive shifts in both organic and carbonate carbon isotopic records and likely a decrease in atmospheric pCO2. A hypothesised causal linkage is proposed in which the rapid post-eruptive basaltic weathering of the Emeishan province in an equatorial humid belt may accelerate the atmospheric CO2 consumption and lead to climate cooling. Our work supports the long-term climate cooling effects of large igneous provinces.

  1. Passive avoidance and complex maze learning in the senescence accelerated mouse (SAM): age and strain comparisons of SAM P8 and R1.

    PubMed

    Spangler, Edward L; Patel, Namisha; Speer, Dorey; Hyman, Michael; Hengemihle, John; Markowska, Alicja; Ingram, Donald K

    2002-02-01

    Two strains of the senescence accelerated mouse, P8 and R1,were tested in footshock-motivated passive avoidance (PA; P8, 3-21 months; R1, 3-24 months) and 14-unit T-maze (P8 and R1, 9, and 15 months) tasks. For PA, entry to a dark chamber from a lighted chamber was followed by a brief shock. Latency to enter the dark chamber 24 hours later served as a measure of retention. Two days of active avoidance training in a straight runway preceded 2 days (8 trials/day) of testing in the 14-unit T-maze. For PA retention, older P8 mice entered the dark chamber more quickly than older R1 mice, whereas no differences were observed between young P8 or R1 mice. In the 14-unit T-maze, age-related learning performance deficits were reflected in higher error scores for older mice. P8 mice were actually superior learners; that is, they had lower error scores compared with those of age-matched R1 counterparts. Although PA learning results were in agreement with other reports, results obtained in the 14-unit T-maze were not consistent with previous reports of learning impairments in the P8 senescence accelerated mouse.

  2. NOAA Weather Radio

    Science.gov Websites

    Questions NOAA WEATHER RADIO Marine Coverage The NOAA Weather Radio network provides near continuous coverage of the coastal U.S, Great Lakes, Hawaii, and populated Alaska coastline. Typical coverage is 25 Transmitter frequency, call sign and power; and remarks (if any.) Atlantic Gulf of Mexico Great Lakes West

  3. Weatherizing a Structure.

    ERIC Educational Resources Information Center

    Metz, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with weatherizing a structure. Its objective is for the student to be able to analyze factors related to specific structures that indicate need for weatherizing activities and to determine steps to correct defects in structures that…

  4. Weather Forecaster Understanding of Climate Models

    NASA Astrophysics Data System (ADS)

    Bol, A.; Kiehl, J. T.; Abshire, W. E.

    2013-12-01

    Weather forecasters, particularly those in broadcasting, are the primary conduit to the public for information on climate and climate change. However, many weather forecasters remain skeptical of model-based climate projections. To address this issue, The COMET Program developed an hour-long online lesson of how climate models work, targeting an audience of weather forecasters. The module draws on forecasters' pre-existing knowledge of weather, climate, and numerical weather prediction (NWP) models. In order to measure learning outcomes, quizzes were given before and after the lesson. Preliminary results show large learning gains. For all people that took both pre and post-tests (n=238), scores improved from 48% to 80%. Similar pre/post improvement occurred for National Weather Service employees (51% to 87%, n=22 ) and college faculty (50% to 90%, n=7). We believe these results indicate a fundamental misunderstanding among many weather forecasters of (1) the difference between weather and climate models, (2) how researchers use climate models, and (3) how they interpret model results. The quiz results indicate that efforts to educate the public about climate change need to include weather forecasters, a vital link between the research community and the general public.

  5. Assessing the influence of humic acids on the weathering of galena and its environmental implications.

    PubMed

    Liu, Qingyou; Li, Heping; Jin, Guoheng; Zheng, Kai; Wang, Luying

    2018-08-30

    Galena weathering often occurs in nature and releases metal ions during the process. Humic acid (HA), a critical particle of natural organic matter, binds metal ions, thus affecting metal transfer and transformation. In this work, an electrochemical method combined with spectroscopic techniques was adopted to investigate the interfacial processes involved in galena weathering under acidic and alkaline conditions, as well as in the presence of HA. The results show that the initial step of galena weathering involved the transformation Pb 2+ and S°, regardless of whether the solution was acidic or alkaline. Under acidic conditions, S° and Pb 2+ further transform into anglesite, and HA adsorbs on the galena surface, inhibiting the transformation of sulfur. HA and Pb (II) ions form bridging complexes. Under alkaline conditions without HA, the sulfur produced undergoes no transformation, whereas Pb 2+ will transform into PbO. The presence of HA changes the galena weathering mechanism via ionization effect, and Pb 2+ is ultimately converted into anglesite. Higher acidity in acidic conditions or higher alkalinity in alkaline conditions causes galena corrosion when the electrolyte does not contain HA. Conversely, higher pH always accelerates galena corrosion when the electrolyte contains HA, whether the electrolyte is acidic or alkaline. At the same acidity/alkalinity, increasing the concentration of HA inhibits galena weathering. Galena will release 134.7 g m -2 ·y -1 Pb 2+ to solution at pH 2.5, and the amount decreases to 28.09 g m -2 ·y -1 in the presence of 1000 mg/L HA. This study provides an in situ electrochemical method for the assessment of galena weathering. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Making a Fish Tank Cloud Chamber

    ERIC Educational Resources Information Center

    Green, Frances

    2012-01-01

    The cloud chambers described here are large, made from readily available parts, simple to set up and always work. With no source in the chamber, background radiation can be observed. A large chamber means that a long rod containing a weakly radioactive material can be introduced, increasing the chance of seeing decays. Details of equipment and…

  7. 46 CFR 45.187 - Weather limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

  8. 46 CFR 45.187 - Weather limitations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

  9. 46 CFR 45.187 - Weather limitations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

  10. 46 CFR 45.187 - Weather limitations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

  11. 46 CFR 45.187 - Weather limitations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

  12. Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes

    USGS Publications Warehouse

    Jones, B.F.; Herman, J.S.

    2008-01-01

    Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and oxyhydroxides, and solute fluxes (Meunier and Velde, 1979). The chemical composition of the clay-mineral product is often ignored. However, in earlier investigations, the saprolitic weathering profile at the South Fork Brokenback Run (SFBR) watershed, Shenandoah National Park, Virginia, was characterized extensively in terms of its mineralogical and chemical composition (Piccoli, 1987; Pochatila et al., 2006; Jones et al., 2007) and its basic hydrology. O'Brien et al. (1997) attempted to determine the contribution of primary mineral weathering to observed stream chemistry at SFBR. Mass-balance model results, however, could provide only a rough estimate of the weathering reactions because idealized mineral compositions were utilized in the calculations. Making use of detailed information on the mineral occurrence in the regolith, the objective of the present study was to evaluate the effects of compositional variation on mineral-solute mass-balance modelling and to generate plausible quantitative weathering reactions that support both the chemical evolution of the surface water and ground water in the catchment, as well as the mineralogical evolution of the weathering profile. ?? 2008 The Mineralogical Society.

  13. Enhanced Weather Radar (EWxR) System

    NASA Technical Reports Server (NTRS)

    Kronfeld, Kevin M. (Technical Monitor)

    2003-01-01

    An airborne weather radar system, the Enhanced Weather Radar (EWxR), with enhanced on-board weather radar data processing was developed and tested. The system features additional weather data that is uplinked from ground-based sources, specialized data processing, and limited automatic radar control to search for hazardous weather. National Weather Service (NWS) ground-based Next Generation Radar (NEXRAD) information is used by the EWxR system to augment the on-board weather radar information. The system will simultaneously display NEXRAD and on-board weather radar information in a split-view format. The on-board weather radar includes an automated or hands-free storm-finding feature that optimizes the radar returns by automatically adjusting the tilt and range settings for the current altitude above the terrain and searches for storm cells near the atmospheric 0-degree isotherm. A rule-based decision aid was developed to automatically characterize cells as hazardous, possibly-hazardous, or non-hazardous based upon attributes of that cell. Cell attributes are determined based on data from the on-board radar and from ground-based radars. A flight path impact prediction algorithm was developed to help pilots to avoid hazardous weather along their flight plan and their mission. During development the system was tested on the NASA B757 aircraft and final tests were conducted on the Rockwell Collins Sabreliner.

  14. SU‐C‐105‐05: Reference Dosimetry of High‐Energy Electron Beams with a Farmer‐Type Ionization Chamber

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

    Muir, B; Rogers, D

    2013-06-15

    Purpose: To investigate gradient effects and provide Monte Carlo calculated beam quality conversion factors to characterize the Farmer‐type NE2571 ion chamber for high‐energy reference dosimetry of clinical electron beams. Methods: The EGSnrc code system is used to calculate the absorbed dose to water and to the gas in a fully modeled NE2571 chamber as a function of depth in a water phantom. Electron beams incident on the surface of the phantom are modeled using realistic BEAMnrc accelerator simulations and electron beam spectra. Beam quality conversion factors are determined using calculated doses to water and to air in the chamber inmore » high‐energy electron beams and in a cobalt‐60 reference field. Calculated water‐to‐air stopping power ratios are employed for investigation of the overall ion chamber perturbation factor. Results: An upstream shift of 0.3–0.4 multiplied by the chamber radius, r-cav, both minimizes the variation of the overall ion chamber perturbation factor with depth and reduces the difference between the beam quality specifier (R{sub 5} {sub 0}) calculated using ion chamber simulations and that obtained with simulations of dose‐to‐water in the phantom. Beam quality conversion factors are obtained at the reference depth and gradient effects are optimized using a shift of 0.2r-cav. The photon‐electron conversion factor, k-ecal, amounts to 0.906 when gradient effects are minimized using the shift established here and 0.903 if no shift of the data is used. Systematic uncertainties in beam quality conversion factors are investigated and amount to between 0.4 to 1.1% depending on assumptions used. Conclusion: The calculations obtained in this work characterize the use of an NE2571 ion chamber for reference dosimetry of high‐energy electron beams. These results will be useful as the AAPM continues to review their reference dosimetry protocols.« less

  15. Weathering Database Technology

    ERIC Educational Resources Information Center

    Snyder, Robert

    2005-01-01

    Collecting weather data is a traditional part of a meteorology unit at the middle level. However, making connections between the data and weather conditions can be a challenge. One way to make these connections clearer is to enter the data into a database. This allows students to quickly compare different fields of data and recognize which…

  16. Teacher's Weather Sourcebook.

    ERIC Educational Resources Information Center

    Konvicka, Tom

    This book is a teaching resource for the study of weather-related phenomena. A "weather unit" is often incorporated into school study because of its importance to our daily lives and because of its potential to cut across disciplinary content. This book consists of two parts. Part I covers the major topics of atmospheric science such as the modern…

  17. Natural Weathering Rates of Silicate Minerals

    NASA Astrophysics Data System (ADS)

    White, A. F.

    2003-12-01

    Silicates constitute more than 90% of the rocks exposed at Earth's land surface (Garrels and Mackenzie, 1971). Most primary minerals comprising these rocks are thermodynamically unstable at surface pressure/temperature conditions and are therefore susceptible to chemical weathering. Such weathering has long been of interest in the natural sciences. Hartt (1853) correctly attributed chemical weathering to "the efficacy of water containing carbonic acid in promoting the decomposition of igneous rocks." Antecedent to the recent interest in the role of vegetation on chemical weathering, Belt (1874) observed that the most intense weathering of rocks in tropical Nicaragua was confined to forested regions. He attributed this effect to "the percolation through rocks of rain water charged with a little acid from decomposing vegetation." Chamberlin (1899) proposed that the enhanced rates of chemical weathering associated with major mountain building episodes in Earth's history resulted in a drawdown of atmospheric CO2 that led to periods of global cooling. Many of the major characteristics of chemical weathering had been described when Merrill (1906) published the groundbreaking volume Rocks, Rock Weathering, and Soils.The major advances since that time, particularly during the last several decades, have centered on understanding the fundamental chemical, hydrologic, and biologic processes that control weathering and in establishing quantitative weathering rates. This research has been driven by the importance of chemical weathering to a number environmentally and economically important issues. Undoubtedly, the most significant aspect of chemical weathering is the breakdown of rocks to form soils, a process that makes life possible on the surface of the Earth. The availability of many soil macronutrients such as magnesium, calcium, potassium, and PO4 is directly related to the rate at which primary minerals weather. Often such nutrient balances are upset by anthropogenic

  18. Electromagnetic analysis of the plasma chamber of an ECR-based charge breeder

    NASA Astrophysics Data System (ADS)

    Galatà, A.; Patti, G.; Celona, L.; Mascali, D.; Neri, L.; Torrisi, G.

    2016-02-01

    The optimization of the efficiency of an ECR-based charge breeder is a twofold task: efforts must be paid to maximize the capture of the injected 1+ ions by the confined plasma and to produce high charge states to allow post-acceleration at high energies. Both tasks must be faced by studying in detail the electrons heating dynamics, influenced by the microwave-to-plasma coupling mechanism. Numerical simulations are a powerful tools for obtaining quantitative information about the wave-to-plasma interaction process: this paper presents a numerical study of the microwaves propagation and absorption inside the plasma chamber of the PHOENIX charge breeder, which the selective production of exotic species project, under construction at Legnaro National Laboratories, will adopt as charge breeder. Calculations were carried out with a commercial 3D FEM solver: first, all the resonant frequencies were determined by considering a simplified plasma chamber; then, the realistic geometry was taken into account, including a cold plasma model of increasing complexity. The results gave important information about the power absorption and losses and will allow the improvement of the plasma model to be used in a refined step of calculation reproducing the breeding process itself.

  19. Space Weather Forecasting: An Enigma

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.

    2012-12-01

    The space age began in earnest on October 4, 1957 with the launch of Sputnik 1 and was fuelled for over a decade by very strong national societal concerns. Prior to this single event the adverse effects of space weather had been registered on telegraph lines as well as interference on early WWII radar systems, while for countless eons the beauty of space weather as mid-latitude auroral displays were much appreciated. These prior space weather impacts were in themselves only a low-level science puzzle pursued by a few dedicated researchers. The technology boost and innovation that the post Sputnik era generated has almost single handedly defined our present day societal technology infrastructure. During the decade following Neil's walk on the moon on July 21, 1969 an international thrust to understand the science of space, and its weather, was in progress. However, the search for scientific understand was parsed into independent "stove pipe" categories: The ionosphere-aeronomy, the magnetosphere, the heliosphere-sun. The present day scientific infrastructure of funding agencies, learned societies, and international organizations are still hampered by these 1960's logical divisions which today are outdated in the pursuit of understanding space weather. As this era of intensive and well funded scientific research progressed so did societies innovative uses for space technologies and space "spin-offs". Well over a decade ago leaders in technology, science, and the military realized that there was indeed an adverse side to space weather that with each passing year became more severe. In 1994 several U.S. agencies established the National Space Weather Program (NSWP) to focus scientific attention on the system wide issue of the adverse effects of space weather on society and its technologies. Indeed for the past two decades a significant fraction of the scientific community has actively engaged in understanding space weather and hence crossing the "stove

  20. Weathered stony meteorites from Victoria Land, Antarctica, as possible guides to rock weathering on Mars

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1984-01-01

    Parallel studies of Martian geomorphic features and their analogs on Earth continue to be fruitful in deciphering the geologic history of Mars. In the context of rock weathering, the Earth-analog approach is admirably served by the study of meteorites recovered from ice sheets in Antarctica. The weathering environment of Victoria Land possesses several Mars-like attributes. Four of the five Antarctic meteorites being studied contain rust and EETA79005 further possesses a conspicuous, dark, weathering rind on one side. Secondary minerals (rust and salts) occur both on the surfaces and interiors of some of the samples and textural evidence indicates that such secondary mineralization contributed to physical weathering (by salt riving) of the rocks. Several different rust morphologies occur and emphasis is being placed on identifying the phase compositions of the various rust occurrances. A thorough understanding of terrestrial weathering features of the meteorites is a prerequisite for identifying possible Martian weathering features (if such features exist) that might be postulated to occur in some meteorites.

  1. Weather Fundamentals: Climate & Seasons. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes), describes weather patterns and cycles around the globe. The various types of climates around…

  2. Hyperbaric and hypobaric chamber fires: a 73-year analysis.

    PubMed

    Sheffield, P J; Desautels, D A

    1997-09-01

    Fire can be catastrophic in the confined space of a hyperbaric chamber. From 1923 to 1996, 77 human fatalities occurred in 35 hyperbaric chamber fires, three human fatalities in a pressurized Apollo Command Module, and two human fatalities in three hypobaric chamber fires reported in Asia, Europe, and North America. Two fires occurred in diving bells, eight occurred in recompression (or decompression) chambers, and 25 occurred in clinical hyperbaric chambers. No fire fatalities were reported in the clinical hyperbaric chambers of North America. Chamber fires before 1980 were principally caused by electrical ignition. Since 1980, chamber fires have been primarily caused by prohibited sources of ignition that an occupant carried inside the chamber. Each fatal chamber fire has occurred in an enriched oxygen atmosphere (> 28% oxygen) and in the presence of abundant burnable material. Chambers pressurized with air (< 23.5% oxygen) had the only survivors. Information in this report was obtained from the literature and from the Undersea and Hyperbaric Medical Society's Chamber Experience and Mishap Database. This epidemiologic review focuses on information learned from critical analyses of chamber fires and how it can be applied to safe operation of hypobaric and hyperbaric chambers.

  3. Weather Augmented Risk Determination (WARD) System

    NASA Astrophysics Data System (ADS)

    Niknejad, M.; Mazdiyasni, O.; Momtaz, F.; AghaKouchak, A.

    2017-12-01

    Extreme climatic events have direct and indirect impacts on society, economy and the environment. Based on the United States Bureau of Economic Analysis (BEA) data, over one third of the U.S. GDP can be considered as weather-sensitive involving some degree of weather risk. This expands from a local scale concrete foundation construction to large scale transportation systems. Extreme and unexpected weather conditions have always been considered as one of the probable risks to human health, productivity and activities. The construction industry is a large sector of the economy, and is also greatly influenced by weather-related risks including work stoppage and low labor productivity. Identification and quantification of these risks, and providing mitigation of their effects are always the concerns of construction project managers. In addition to severe weather conditions' destructive effects, seasonal changes in weather conditions can also have negative impacts on human health. Work stoppage and reduced labor productivity can be caused by precipitation, wind, temperature, relative humidity and other weather conditions. Historical and project-specific weather information can improve better project management and mitigation planning, and ultimately reduce the risk of weather-related conditions. This paper proposes new software for project-specific user-defined data analysis that offers (a) probability of work stoppage and the estimated project length considering weather conditions; (b) information on reduced labor productivity and its impacts on project duration; and (c) probabilistic information on the project timeline based on both weather-related work stoppage and labor productivity. The software (WARD System) is designed such that it can be integrated into the already available project management tools. While the system and presented application focuses on the construction industry, the developed software is general and can be used for any application that involves

  4. Climate Prediction - NOAA's National Weather Service

    Science.gov Websites

    Statistical Models... MOS Prod GFS-LAMP Prod Climate Past Weather Predictions Weather Safety Weather Radio National Weather Service on FaceBook NWS on Facebook NWS Director Home > Climate > Predictions Climate Prediction Long range forecasts across the U.S. Climate Prediction Web Sites Climate Prediction

  5. Space Weathering on Airless Bodies.

    PubMed

    Pieters, Carle M; Noble, Sarah K

    2016-10-01

    Space weathering refers to alteration that occurs in the space environment with time. Lunar samples, and to some extent meteorites, have provided a benchmark for understanding the processes and products of space weathering. Lunar soils are derived principally from local materials but have accumulated a range of optically active opaque particles (OAOpq) that include nanophase metallic iron on/in rims formed on individual grains (imparting a red slope to visible and near-infrared reflectance) and larger iron particles (which darken across all wavelengths) such as are often found within the interior of recycled grains. Space weathering of other anhydrous silicate bodies, such as Mercury and some asteroids, produce different forms and relative abundance of OAOpq particles depending on the particular environment. If the development of OAOpq particles is minimized (such as at Vesta), contamination by exogenic material and regolith mixing become the dominant space weathering processes. Volatile-rich bodies and those composed of abundant hydrous minerals (dwarf planet Ceres, many dark asteroids, outer solar system satellites) are affected by space weathering processes differently than the silicate bodies of the inner solar system. However, the space weathering products of these bodies are currently poorly understood and the physics and chemistry of space weathering processes in different environments are areas of active research.

  6. Space Weathering on Airless Bodies

    PubMed Central

    Pieters, Carle M.; Noble, Sarah K.

    2018-01-01

    Space weathering refers to alteration that occurs in the space environment with time. Lunar samples, and to some extent meteorites, have provided a benchmark for understanding the processes and products of space weathering. Lunar soils are derived principally from local materials but have accumulated a range of optically active opaque particles (OAOpq) that include nanophase metallic iron on/in rims formed on individual grains (imparting a red slope to visible and near-infrared reflectance) and larger iron particles (which darken across all wavelengths) such as are often found within the interior of recycled grains. Space weathering of other anhydrous silicate bodies, such as Mercury and some asteroids, produce different forms and relative abundance of OAOpq particles depending on the particular environment. If the development of OAOpq particles is minimized (such as at Vesta), contamination by exogenic material and regolith mixing become the dominant space weathering processes. Volatile-rich bodies and those composed of abundant hydrous minerals (dwarf planet Ceres, many dark asteroids, outer solar system satellites) are affected by space weathering processes differently than the silicate bodies of the inner solar system. However, the space weathering products of these bodies are currently poorly understood and the physics and chemistry of space weathering processes in different environments are areas of active research. PMID:29862145

  7. Severe Weather Planning for Schools

    ERIC Educational Resources Information Center

    Watson, Barbara McNaught; Strong, Christopher; Bunting, Bill

    2008-01-01

    Flash floods, severe thunderstorms, and tornadoes occur with rapid onset and often no warning. Decisions must be made quickly and actions taken immediately. This paper provides tips for schools on: (1) Preparing for Severe Weather Emergencies; (2) Activating a Severe Weather Plan; (3) Severe Weather Plan Checklist; and (4) Periodic Drills and…

  8. Comparison of characteristics of aerosol during rainy weather and cold air-dust weather in Guangzhou in late March 2012

    NASA Astrophysics Data System (ADS)

    Chen, Huizhong; Wu, Dui; Yu, Jianzhen

    2016-04-01

    Using the data on aerosol observed hourly by Marga ADI 2080 and Grimm 180, we compared the characteristics of aerosol during rainy weather and cold air-dust weather in Guangzhou in late March 2012. The mass concentration of aerosol appeared distinct between the two weather processes. During rainy weather, the mass concentration of PM and total water-soluble components decreased obviously. During cold air-dust weather, the cleaning effect of cold air occurred much more suddenly and about a half day earlier than the dust effect. As a result, the mass concentration of PM and total water-soluble components first dropped dramatically to a below-normal level and then rose gradually to an above-normal level. The ratio of PM2.5/PM10 and PM1/PM10 decreased, suggesting that dust-storm weather mainly brought in coarse particles. The proportion of Ca2+ in the total water-soluble components significantly increased to as high as 50 % because of the effect of dust weather. We further analysed the ionic equilibrium during rainy and cold air-dust weather, and compared it with that during hazy weather during the same period. The aerosol during rainy weather was slightly acidic, whereas that during hazy weather and cold air-dust weather was obviously alkaline, with that during cold air-dust weather being significantly more alkaline. Most of the anions, including SO4 2- and NO3 -, were neutralised by NH4 + during rainy and hazy weather, and by Ca2+ during cold air-dust weather.

  9. The Application of Synoptic Weather Forecasting Rules to Selected Weather Situations in the United States.

    ERIC Educational Resources Information Center

    Kohler, Fred E.

    The document describes the use of weather maps and data in teaching introductory college courses in synoptic meteorology. Students examine weather changes at three-hour intervals from data obtained from the "Monthly Summary of Local Climatological Data." Weather variables in the local summary include sky cover, air temperature, dew point, relative…

  10. Chamber for Growing and Observing Fungi

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Molina, Thomas C.

    2005-01-01

    A chamber has been designed to enable growth and observation of microcolonies of fungi in isolation from the external environment. Unlike prior fungus-growing apparatuses, this chamber makes it possible to examine a fungus culture without disrupting it. Partly resembling a small picture frame, the chamber includes a metal plate having a rectangular through-thethickness opening with recesses for a top and a bottom cover glass, an inlet for air, and an inlet for water. The bottom cover glass is put in place and held there by clips, then a block of nutrient medium and a moisture pad are placed in the opening. The block is inoculated, then the top cover glass is put in place and held there by clips. Once growth is evident, the chamber can be sealed with tape. Little (if any) water evaporates past the edges of the cover glasses, and, hence there is little (if any) need to add water. A microscope can be used to observe the culture through either cover glass. Because the culture is sealed in the chamber, it is safe to examine the culture without risking contamination. The chamber can be sterilized and reused.

  11. Upright Imaging of Drosophila Egg Chambers

    PubMed Central

    Manning, Lathiena; Starz-Gaiano, Michelle

    2015-01-01

    Drosophila melanogaster oogenesis provides an ideal context for studying varied developmental processes since the ovary is relatively simple in architecture, is well-characterized, and is amenable to genetic analysis. Each egg chamber consists of germ-line cells surrounded by a single epithelial layer of somatic follicle cells. Subsets of follicle cells undergo differentiation during specific stages to become several different cell types. Standard techniques primarily allow for a lateral view of egg chambers, and therefore a limited view of follicle cell organization and identity. The upright imaging protocol describes a mounting technique that enables a novel, vertical view of egg chambers with a standard confocal microscope. Samples are first mounted between two layers of glycerin jelly in a lateral (horizontal) position on a glass microscope slide. The jelly with encased egg chambers is then cut into blocks, transferred to a coverslip, and flipped to position egg chambers upright. Mounted egg chambers can be imaged on either an upright or an inverted confocal microscope. This technique enables the study of follicle cell specification, organization, molecular markers, and egg development with new detail and from a new perspective. PMID:25867882

  12. Performance parameters of a liquid filled ionization chamber array

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

    Poppe, B.; Stelljes, T. S.; Looe, H. K.

    2013-08-15

    Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluatedmore » using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The

  13. World weather program

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A brief description of the Global Weather Experiment is presented. The world weather watch program plan is described and includes a global observing system, a global data processing system, a global telecommunication system, and a voluntary cooperation program. A summary of Federal Agency plans and programs to meet the challenges of international meteorology for the two year period, FY 1980-1981, is presented.

  14. Development research for wind power weather insurance index through analysis of weather elements and new renewable energy

    NASA Astrophysics Data System (ADS)

    Park, Ki-Jun; jung, jihoon

    2014-05-01

    Recently, social interests and concerns regarding weather risk are gradually growing with increase in frequency of unusual phenomena. Actually, the threat to many vulnerable industries (sensitive to climate conditions) such as agriculture, architecture, logistics, transportation, clothing, home appliance, and food is increasing. According to climate change scenario reports published by National Institute of Meteorological Research (NIMR) in 2012, temperature and precipitation are expected to increase by 4.8% and 13.2% respectively with current status of CO2 emissions (RCP 8.5) at the end of the 21st century. Furthermore, most of areas in Korea except some mountainous areas are also expected to shift from temperate climate to subtropical climate. In the context of climate change, the intensity of severe weathers such as heavy rainfalls and droughts is enhanced, which, in turn, increases the necessity and importance of weather insurance. However, most insurance market is small and limited to policy insurance like crop disaster insurance, and natural disaster insurance in Korea. The reason for poor and small weather insurance market could result from the lack of recognition of weather risk management even though all economic components (firms, governments, and households) are significantly influenced by weather. However, fortunately, new renewable energy and leisure industry which are vulnerable to weather risk are in a long term uptrend and the interest of weather risk is also getting larger and larger in Korea. So, in the long run, growth potential of weather insurance market in Korea might be higher than ever. Therefore, in this study, the capacity of power generation per hour and hourly wind speed are analyzed to develop and test weather insurance index for wind power, and then the effectiveness of weather insurance index are investigated and the guidance will be derived to objectively calculate the weather insurance index.

  15. SU-G-TeP1-03: Beam Quality Correction Factors for Linear Accelerator with and Without Flattening Filter

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

    Czarnecki, D; Voigts-Rhetz, P von; Zink, K

    2016-06-15

    Purpose: The impact of removing the flattening filter on absolute dosimetry based on IAEA’s TPR-398 and AAPM’s TG-51 was investigated in this study using Monte Carlo simulations. Methods: The EGSnrc software package was used for all Monte Carlo simulations performed in this work. Five different ionization chambers and nine linear accelerator heads have been modeled according to technical drawings. To generate a flattening filter free radiation field the flattening filter was replaced by a 2 mm thick aluminum layer. Dose calculation in a water phantom were performed to calculate the beam quality correction factor k{sub Q} as a function ofmore » the beam quality specifiers %dd(10){sub x}, TPR{sub 20,10} and mean photon and electron energies at the point of measurement in photon fields with (WFF) and without flattening filter (FFF). Results: The beam quality correction factor as a function of %dd(10){sub x} differs systematically between FFF and WFF beams for all investigated ionization chambers. The largest difference of 1.8% was observed for the largest investigated Farmer-type ionization chamber with a sensitive volume of 0.69 cm{sup 3}. For ionization chambers with a smaller nominal sensitive volume (0.015 – 0.3 cm{sup 3}) the deviation was less than 0.4% between WFF and FFF beams for %dd(10){sub x} > 62%. The specifier TPR{sub 20,10} revealed only a good correlation between WFF and FFF beams (< 0.3%) for low energies. Conclusion: The results confirm that %dd(10){sub x} is a suitable beam quality specifier for FFF beams with an acceptable bias. The deviation depends on the volume of the ionization chamber. Using %dd(10){sub x} to predict k{sub Q} for a large volume chamber in a FFF photon field may lead to not acceptable errors according to the results of this study. This bias may be caused by the volume effect due to the inhomogeneous photon fields of FFF linear accelerators.« less

  16. Does the Weather Really Matter?

    NASA Astrophysics Data System (ADS)

    Burroughs, William James

    1997-09-01

    We talk about it endlessly, write about it copiously, and predict it badly. It influences what we do, what we wear, and how we live. Weather--how does it really impact our lives? In this compelling look at weather, author Burroughs combines historical perspective and economic and political analysis to give the impact of weather and climate change relevance and weight. He examines whether the frequency of extreme events is changing and the consequences of these changes. He looks at the chaotic nature of the climate and how this unpredictability can impose serious limits on how we plan for the future. Finally, he poses the important question: what types of serious, even less predictable changes are around the corner? In balanced and accessible prose, Burroughs works these issues into lucid analysis. This refreshing and insightful look at the impact of weather will appeal to anyone who has ever worried about forgetting an umbrella. William James Burroughs is the author of Watching the World's Weather (CUP, 1991) and Weather Cycles: Real or Imaginary? (CUP, 1994).

  17. LRL 25-inch Bubble Chamber

    DOE R&D Accomplishments Database

    Alvarez, L. W.; Gow, J. D.; Barrera, F.; Eckman, G.; Shand, J.; Watt, R.; Norgren, D.; Hernandez, H. P.

    1964-07-08

    The recently completed 25-inch hydrogen bubble chamber combines excellent picture quality with a fast operating cycle. The chamber has a unique optical system and is designed to take several pictures each Bevatron pulse, in conjunction with the Bevatron rapid beam ejection system.

  18. Weather information network including graphical display

    NASA Technical Reports Server (NTRS)

    Leger, Daniel R. (Inventor); Burdon, David (Inventor); Son, Robert S. (Inventor); Martin, Kevin D. (Inventor); Harrison, John (Inventor); Hughes, Keith R. (Inventor)

    2006-01-01

    An apparatus for providing weather information onboard an aircraft includes a processor unit and a graphical user interface. The processor unit processes weather information after it is received onboard the aircraft from a ground-based source, and the graphical user interface provides a graphical presentation of the weather information to a user onboard the aircraft. Preferably, the graphical user interface includes one or more user-selectable options for graphically displaying at least one of convection information, turbulence information, icing information, weather satellite information, SIGMET information, significant weather prognosis information, and winds aloft information.

  19. Weatherization Plays a Starring Role in Mississippi: Weatherization Assistance Close-Up Fact Sheet

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

    D&R International

    2001-10-10

    Mississippi demonstrates its commitment to technology and efficiency through the Weatherization Program. Weatherization uses advanced technologies and techniques to reduce energy costs for low-income families by increasing the energy efficiency of their homes.

  20. Reducing Aviation Weather-Related Accidents Through High-Fidelity Weather Information Distribution and Presentation

    NASA Technical Reports Server (NTRS)

    Stough, H. Paul, III; Shafer, Daniel B.; Schaffner, Philip R.; Martzaklis, Konstantinos S.

    2000-01-01

    In February 1997, the US President announced a national goal to reduce the fatal accident rate for aviation by 80% within ten years. The National Aeronautics and Space Administration established the Aviation Safety Program to develop technologies needed to meet this aggressive goal. Because weather has been identified (is a causal factor in approximately 30% of all aviation accidents, a project was established for the development of technologies that will provide accurate, time and intuitive information to pilots, dispatchers, and air traffic controllers to enable the detection and avoidance of atmospheric hazards. This project addresses the weather information needs of general, corporate, regional, and transport aircraft operators. An overview and status of research and development efforts for high-fidelity weather information distribution and presentation is discussed with emphasis on weather information in the cockpit.

  1. Impact of accelerated plant growth on seed variety development

    NASA Astrophysics Data System (ADS)

    Christophersen, Eric

    1998-01-01

    The commercial lives of agricultural seed products have steadily declined in recent years. The introduction of genetically engineered crop seeds in 1966 has accentuated that trend. Widespread grower demand for genetically engineered seed requires competitive response by industry followers in order to avert market share losses to the industry leaders. Limitations on plant transformation technology, regulatory requirements and patent impediments require companies to rapidly convert transformed lines into elite commercial products. Massive multigenerational backcrossing efforts are required to distribute genetically engineered traits into a broad product mix. Significant incidents of expression failures, or ``gene silencing,'' have occurred unexpectedly, requiring product substitution strategies. First-to-market strategies, competitive response, broad germplasm conversion and rescue of product failures all share the element of urgency. Technologies which reliably accelerate product development rates can expect favorable reception by commercial seed developers. A growth chamber which dramatically accelerates the rate of plant growth is described.

  2. Where fast weathering creates thin regolith and slow weathering creates thick regolith

    USGS Publications Warehouse

    Bazilevskaya, Ekaterina; Lebedeva, Marina; Pavich, Milan J.; Brantley, Susan L.; Rother, Gernot; Parkinson, Dilworth Y.; Cole, David

    2013-01-01

    Weathering disaggregates rock into regolith – the fractured or granular earth material that sustains life on the continental land surface. Here, we investigate what controls the depth of regolith formed on ridges of two rock compositions with similar initial porosities in Virginia (USA). A priori, we predicted that the regolith on diabase would be thicker than on granite because the dominant mineral (feldspar) in the diabase weathers faster than its granitic counterpart. However, weathering advanced 20 deeper into the granite than the diabase. The 20 -thicker regolith is attributed mainly to connected micron-sized pores, microfractures formed around oxidizing biotite at 20 m depth, and the lower iron (Fe) content in the felsic rock. Such porosity allows pervasive advection and deep oxidation in the granite. These observations may explain why regolith worldwide is thicker on felsic compared to mafic rock under similar conditions. To understand regolith formation will require better understanding of such deep oxidation reactions and how they impact fluid flow during weathering.

  3. Guidelines for disseminating road weather messages.

    DOT National Transportation Integrated Search

    2010-06-01

    The tremendous growth in the amount of available weather and road condition informationincluding devices that gather weather information, models and forecasting tools for predicting weather conditions, and electronic devices used by travelersha...

  4. AWE: Aviation Weather Data Visualization Environment

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly; Lodha, Suresh K.; Norvig, Peter (Technical Monitor)

    2000-01-01

    Weather is one of the major causes of aviation accidents. General aviation (GA) flights account for 92% of all the aviation accidents, In spite of all the official and unofficial sources of weather visualization tools available to pilots, there is an urgent need for visualizing several weather related data tailored for general aviation pilots. Our system, Aviation Weather Data Visualization Environment AWE), presents graphical displays of meteorological observations, terminal area forecasts, and winds aloft forecasts onto a cartographic grid specific to the pilot's area of interest. Decisions regarding the graphical display and design are made based on careful consideration of user needs. Integral visual display of these elements of weather reports is designed for the use of GA pilots as a weather briefing and route selection tool. AWE provides linking of the weather information to the flight's path and schedule. The pilot can interact with the system to obtain aviation-specific weather for the entire area or for his specific route to explore what-if scenarios and make "go/no-go" decisions. The system, as evaluated by some pilots at NASA Ames Research Center, was found to be useful.

  5. Experimental Investigation of the Distribution of Shock Effects in Regolith Impact Ejecta Using an Ejecta Recovery Chamber

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Montes, R.; Cardenas, F.; Cintala, M. J.

    2016-01-01

    Because the mass-flux of solar system meteoroids is concentrated in the approx. 200 microns size range, small-scale impacts play a key role in driving the space weathering of regoliths on airless bodies. Quantifying this role requires improved data linking the mass, density and velocity of the incoming impactors to the nature of the shock effects produced, with particular emphasis on effects, such as production of impact melt and vapor, that drive the optical changes seen in space weathered regoliths. Of particular importance with regard to space weathering is understanding not only the composition of the shock melt created in small-scale impacts, but also how it is partitioned volumetrically between the local impact site and more widely distributed ejecta. To improve the ability of hypervelocity impact experiments to obtain this type of information, we have developed an enclosed sample target chamber with multiple-geometry interior capture cells for in-situ retention of ejecta from granular targets. A key design objective was to select and test capture cell materials that could meet three requirements: 1) Capture ejecta fragments traveling at various trajectories and velocities away from the impact point, while inducing minimal additional damage relative to the primary shock effects; 2) facilitate follow-up characterization of the ejecta either on or in the cell material by analytical SEM, or ex-situ by microprobe, TEM and other methods; and 3) enable the trajectories of the captured and characterized ejecta to be reconstructed relative to the target.

  6. Learn about Earth Science: Weather. [CD-ROM].

    ERIC Educational Resources Information Center

    2000

    This CD-ROM, designed for students in grades K-2, explores the world of weather. Students investigate weather to learn about climate and the seasons, how animals adapt to weather changes, how clouds tell us about conditions, and how weather plays a part in our everyday lives. The weather calendar lets students record and write about conditions…

  7. SU-F-E-06: Dosimetric Characterization of Small Photons Beams of a Novel Linear Accelerator

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

    Almonte, A; Polanco, G; Sanchez, E

    2016-06-15

    Purpose: The aim of the present contribution was to measure the main dosimetric quantities of small fields produced by UNIQUE and evaluate its matching with the corresponding dosimetric data of one 21EX conventional linear accelerator (Varian) in operation at the same center. The second step was to evaluate comparative performance of the EDGE diode detector and the PinPoint micro-ionization chamber for dosimetry of small fields. Methods: UNIQUE is configured with MLC (120 leaves with 0.5 cm leaf width) and a single low photon energy of 6 MV. Beam data were measured with scanning EDGE diode detector (volume of 0.019 mm{supmore » 3}), a PinPoint micro-ionization chamber (PTW) and for larger fields (≥ 4×4cm{sup 2}) a PTW Semi flex chamber (0.125 cm{sup 3}) was used. The scanning system used was the 3D cylindrical tank manufactured by Sun Nuclear, Inc. The measurement of PDD and profiles were done at 100 cm SSD and 1.5 depth; the relative output factors were measured at 10 cm depth. Results: PDD and the profile data showed less than 1% variation between the two linear accelerators for fields size between 2×2 cm{sup 2} and 5×5cm{sup 2}. Output factor differences was less than 1% for field sizes between 3×3 cm{sup 2} and 10×10 cm{sup 2} and less of 1.5 % for fields of 1.5×1.5 cm{sup 2} and 2×2 cm{sup 2} respectively. The dmax value of the EDGE diode detector, measured from the PDD, was 8.347 mm for 0.5×0,5cm{sup 2} for UNIQUE. The performance of EDGE diode detector was comparable for all measurements in small fields. Conclusion: UNIQUE linear accelerator show similar dosimetrics characteristics as conventional 21EX Varian linear accelerator for small, medium and large field sizes.EDGE detector show good performance by measuring dosimetrics quantities in small fields typically used in IMRT and radiosurgery treatments.« less

  8. Measurements of 59Ni in meteorites by accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Paul, M.; Fifield, L. K.; Fink, D.; Albrecht, A.; Allan, G. L.; Herzog, G.; Tuniz, C.

    1993-10-01

    Isotopic abundances of the radionuclide 59Ni (T1/2 = 76000 yr) were measured by accelerator mass spectrometry with the 14UD Pelletron tandem accelerator at the Australian National University and a detection system solely based on a multianode ionization chamber. The sensitivity limit in the measurement of 59Ni isotopic abundances is 5 × 10-13, as determined by residual interferences from isobaric 59Co and isotopic 58Ni ions. Cosmogenic 59Ni abundances 59Ni/Ni = (8-20) × 10-12 were measured in four samples prepared from the metal phase of two meteorites (mesosiderites). The ratio of the 59Ni abundances to those measured for 41Ca in the silicate phase of the same samples, is in fair agreement with the ratio of the production rates via thermal-neutron capture on 58Ni and 40Ca.

  9. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and maintained...

  10. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and maintained...

  11. An innovative system for supplying air and fuel mixture to a combustion chamber of an engine

    NASA Astrophysics Data System (ADS)

    Saikumar, G. R. Bharath

    2018-04-01

    Conventional carburetors are being used since decades to ensure that the desired ratio of air and fuel enters the combustion chamber for combustion for the purpose of generating power in an Spark Ignition(SI) internal combustion engine. However to increase the efficiency, the carburetor system is gradually being replaced by fuel injection systems. Fuel injection systems use injectors to supply pressurized fuel into the combustion chamber. Owing to the high initial and maintenance cost, carburetors are still ruling in the low cost vehicle domain. An innovative concept is conceived, which is an alternative method to the carburetor system to supply the air and fuel mixture to a combustion chamber of an engine. This system comprises of an inner hollow cylinder with minute holes drilled along its length with an outer cylinder capable of sliding along its length or its longitudinal axis. This system is placed in the venturi instead of the conventional carburetor system. Fuel enters from the bottom inlet of the inner cylinder and flows out through the holes provided along its length. The fuel flow from the inner cylinder is dependent on the size and the number of holes exposed at that instance by the sliding outer cylinder which in turn is connected to the throttle or accelerator.

  12. Venturi vacuum systems for hypobaric chamber operations.

    PubMed

    Robinson, R; Swaby, G; Sutton, T; Fife, C; Powell, M; Butler, B D

    1997-11-01

    Physiological studies of the effects of high altitude on man often require the use of a hypobaric chamber to simulate the reduced ambient pressures. Typical "altitude" chambers in use today require complex mechanical vacuum systems to evacuate the chamber air, either directly or via reservoir system. Use of these pumps adds to the cost of both chamber procurement and maintenance, and service of these pumps requires trained support personnel and regular upkeep. In this report we describe use of venturi vacuum pumps to perform the function of mechanical vacuum pumps for human and experimental altitude chamber operations. Advantages of the venturi pumps include their relatively low procurement cost, small size and light weight, ease of installation and plumbing, lack of moving parts, and independence from electrical power sources, fossil fuels and lubricants. Conversion of three hyperbaric chambers to combined hyper/hypobaric use is described.

  13. Assessing Weather Curiosity in University Students

    NASA Astrophysics Data System (ADS)

    Stewart, A. E.

    2017-12-01

    This research focuses upon measuring an individual's level of trait curiosity about the weather using the Weather Curiosity Scale (WCS). The measure consists of 15 self-report items that describe weather preferences and/or behaviors that people may perform more or less frequently. The author reports on two initial studies of the WCS that have used the responses of 710 undergraduate students from a large university in the southeastern United States. In the first study, factor analysis of the 15 items indicated that the measure was unidimensional - suggesting that its items singularly assessed weather curiosity. The WCS also was internally consistent as evidenced by an acceptable Cronbach's alpha, a = .81). The second study sought to identify other personality variables that may relate with the WCS scores and thus illuminate the nature of weather curiosity. Several clusters of personality variables appear to underlie the curiosity levels people exhibited, the first of which related to perceptual curiosity (r = .59). Being curious about sights, sounds, smells, and textures generally related somewhat to curiosity about weather. Two measures of trait sensitivity to environmental stimulation, the Highly Sensitive Person Scale (r = .47) and the Orientation Sensitivity Scale of the Adult Temperament Questionnaire (r = .43), also predicted weather curiosity levels. Finally, possessing extraverted personality traits (r = .34) and an intense style of experiencing one's emotions (r = .33) related to weather curiosity. How can this measure be used in K-12 or post-secondary settings to further climate literacy? First, the WCS can identify students with natural curiosities about weather and climate so these students may be given more challenging instruction that will leverage their natural interests. Second, high-WCS students may function as weather and climate ambassadors during inquiry-based learning activities and thus help other students who are not as oriented to the

  14. Verification of Space Weather Forecasts using Terrestrial Weather Approaches

    NASA Astrophysics Data System (ADS)

    Henley, E.; Murray, S.; Pope, E.; Stephenson, D.; Sharpe, M.; Bingham, S.; Jackson, D.

    2015-12-01

    The Met Office Space Weather Operations Centre (MOSWOC) provides a range of 24/7 operational space weather forecasts, alerts, and warnings, which provide valuable information on space weather that can degrade electricity grids, radio communications, and satellite electronics. Forecasts issued include arrival times of coronal mass ejections (CMEs), and probabilistic forecasts for flares, geomagnetic storm indices, and energetic particle fluxes and fluences. These forecasts are produced twice daily using a combination of output from models such as Enlil, near-real-time observations, and forecaster experience. Verification of forecasts is crucial for users, researchers, and forecasters to understand the strengths and limitations of forecasters, and to assess forecaster added value. To this end, the Met Office (in collaboration with Exeter University) has been adapting verification techniques from terrestrial weather, and has been working closely with the International Space Environment Service (ISES) to standardise verification procedures. We will present the results of part of this work, analysing forecast and observed CME arrival times, assessing skill using 2x2 contingency tables. These MOSWOC forecasts can be objectively compared to those produced by the NASA Community Coordinated Modelling Center - a useful benchmark. This approach cannot be taken for the other forecasts, as they are probabilistic and categorical (e.g., geomagnetic storm forecasts give probabilities of exceeding levels from minor to extreme). We will present appropriate verification techniques being developed to address these forecasts, such as rank probability skill score, and comparing forecasts against climatology and persistence benchmarks. As part of this, we will outline the use of discrete time Markov chains to assess and improve the performance of our geomagnetic storm forecasts. We will also discuss work to adapt a terrestrial verification visualisation system to space weather, to help

  15. Accelerated stability studies of Sufoofe Sailan: A Unani formulation.

    PubMed

    Rani, Seema; Rahman, Khaleequr; Younis, Peerzada Mohammad

    2015-01-01

    Sufoofe Sailan (SS) is a polyherbal powder preparation used in Unani medicine to treat gynecological diseases. It is observed that SS degrade early as it is in the form of powder; however, the stability study of SS was not carried out till date. To evaluate the accelerated stability of SS. Finished formulation of SS was packed in three airtight transparent polyethylene terephthalate containers. One pack was analyzed just after manufacturing and remaining two packs were kept in stability chamber at 40°C ± 2°C/75% ± 5% RH, of which one pack was analyzed after the completion of three and another after 6 months. Organoleptic, physico-chemical, microbiological parameters along with high-performance thin layer chromatography (HPTLC) fingerprinting were carried out. Organoleptic characters showed no significant change in accelerated stability condition. All physico-chemical parameters showed changes <5%, HPTLC fingerprinting showed minimum changes and microbial studies were in confirmation to the World Health Organization guidelines. SS confirmed to the International Conference on Harmonization Guideline for accelerated testing of the pharmaceutical product on said parameters and as per the Grimm's statement the shelf life of SS may last 20 months.

  16. The light ion pulsed power induction accelerator for ETF

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

    Mazarakis, M.G.; Olson, R.E.; Olson, C.L.

    1994-12-31

    Our Engineering Test Facility (ETF) driver concept is based on HERMES III and RHEPP technologies. Actually, it is a scaled-down version of the LMF design incorporating repetition rate capabilities of up to 10 Hz CW. The preconceptual design presented here provides 200-TW peak power to the ETF target during 10 ns, equal to 2-MJ total ion beam energy. Linear inductive voltage addition driving a self-magnetically insulated transmission line (MITL) is utilized to generate the 36-MV peak voltage needed for lithium ion beams. The {approximately} 3-MA ion current is achieved by utilizing many accelerating modules in parallel. Since the current permore » module is relatively modest ({approximately}300 kA), two-stage or one-stage extraction diodes can be utilized for the generation of singly charged lithium ions. The accelerating modules are arranged symmetrically around the fusion chamber in order to provide uniform irradiation onto the ETF target. In addition, the modules are fired in a programmed sequence in order to generate the optimum power pulse shape onto the target. This design utilizes RHEPP accelerator modules as the principal power source.« less

  17. Generation of X-rays by electrons recycling through thin internal targets of cyclic accelerators

    NASA Astrophysics Data System (ADS)

    Kaplin, V.; Kuznetsov, S.; Uglov, S.

    2018-05-01

    The use of thin (< 10‑3 radiation length) internal targets in cyclic accelerators leads to multiple passes (recycling effect) of electrons through them. The multiplicity of electron passes (M) is determined by the electron energy, accelerator parameters, the thickness, structure and material of a target and leads to an increase in the effective target thickness and the efficiency of radiation generation. The increase of M leads to the increase in the emittance of electron beams which can change the characteristics of radiation processes. The experimental results obtained using the Tomsk synchrotron and betatron showed the possibility of increasing the yield and brightness of coherent X-rays generated by the electrons passing (recycling) through thin crystals and periodic multilayers placed into the chambers of accelerators, when the recycling effect did not influence on the spectral and angular characteristics of generated X-rays.

  18. Vaporization chambers and associated methods

    DOEpatents

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Shunn, Lee P.

    2017-02-21

    A vaporization chamber may include at least one conduit and a shell. The at least one conduit may have an inlet at a first end, an outlet at a second end and a flow path therebetween. The shell may surround a portion of each conduit and define a chamber surrounding the portion of each conduit. Additionally, a plurality of discrete apertures may be positioned at longitudinal intervals in a wall of each conduit, each discrete aperture of the plurality of discrete apertures sized and configured to direct a jet of fluid into each conduit from the chamber. A liquid may be vaporized by directing a first fluid comprising a liquid into the inlet at the first end of each conduit, directing jets of a second fluid into each conduit from the chamber through discrete apertures in a wall of each conduit and transferring heat from the second fluid to the first fluid.

  19. New Technologies for Weather Accident Prevention

    NASA Technical Reports Server (NTRS)

    Stough, H. Paul, III; Watson, James F., Jr.; Daniels, Taumi S.; Martzaklis, Konstantinos S.; Jarrell, Michael A.; Bogue, Rodney K.

    2005-01-01

    Weather is a causal factor in thirty percent of all aviation accidents. Many of these accidents are due to a lack of weather situation awareness by pilots in flight. Improving the strategic and tactical weather information available and its presentation to pilots in flight can enhance weather situation awareness and enable avoidance of adverse conditions. This paper presents technologies for airborne detection, dissemination and display of weather information developed by the National Aeronautics and Space Administration (NASA) in partnership with the Federal Aviation Administration (FAA), National Oceanic and Atmospheric Administration (NOAA), industry and the research community. These technologies, currently in the initial stages of implementation by industry, will provide more precise and timely knowledge of the weather and enable pilots in flight to make decisions that result in safer and more efficient operations.

  20. Browsing Space Weather Data and Models with the Integrated Space Weather Analysis (iSWA) System

    NASA Technical Reports Server (NTRS)

    Maddox, Marlo M.; Mullinix, Richard E.; Berrios, David H.; Hesse, Michael; Rastaetter, Lutz; Pulkkinen, Antti; Hourcle, Joseph A.; Thompson, Barbara J.

    2011-01-01

    The Integrated Space Weather Analysis (iSWA) System is a comprehensive web-based platform for space weather information that combines data from solar, heliospheric and geospace observatories with forecasts based on the most advanced space weather models. The iSWA system collects, generates, and presents a wide array of space weather resources in an intuitive, user-configurable, and adaptable format - thus enabling users to respond to current and future space weather impacts as well as enabling post-impact analysis. iSWA currently provides over 200 data and modeling products, and features a variety of tools that allow the user to browse, combine, and examine data and models from various sources. This presentation will consist of a summary of the iSWA products and an overview of the customizable user interfaces, and will feature several tutorial demonstrations highlighting the interactive tools and advanced capabilities.

  1. Automated Electrostatics Environmental Chamber

    NASA Technical Reports Server (NTRS)

    Calle, Carlos; Lewis, Dean C.; Buchanan, Randy K.; Buchanan, Aubri

    2005-01-01

    The Mars Electrostatics Chamber (MEC) is an environmental chamber designed primarily to create atmospheric conditions like those at the surface of Mars to support experiments on electrostatic effects in the Martian environment. The chamber is equipped with a vacuum system, a cryogenic cooling system, an atmospheric-gas replenishing and analysis system, and a computerized control system that can be programmed by the user and that provides both automation and options for manual control. The control system can be set to maintain steady Mars-like conditions or to impose temperature and pressure variations of a Mars diurnal cycle at any given season and latitude. In addition, the MEC can be used in other areas of research because it can create steady or varying atmospheric conditions anywhere within the wide temperature, pressure, and composition ranges between the extremes of Mars-like and Earth-like conditions.

  2. Upgrade Summer Severe Weather Tool

    NASA Technical Reports Server (NTRS)

    Watson, Leela

    2011-01-01

    The goal of this task was to upgrade to the existing severe weather database by adding observations from the 2010 warm season, update the verification dataset with results from the 2010 warm season, use statistical logistic regression analysis on the database and develop a new forecast tool. The AMU analyzed 7 stability parameters that showed the possibility of providing guidance in forecasting severe weather, calculated verification statistics for the Total Threat Score (TTS), and calculated warm season verification statistics for the 2010 season. The AMU also performed statistical logistic regression analysis on the 22-year severe weather database. The results indicated that the logistic regression equation did not show an increase in skill over the previously developed TTS. The equation showed less accuracy than TTS at predicting severe weather, little ability to distinguish between severe and non-severe weather days, and worse standard categorical accuracy measures and skill scores over TTS.

  3. Smooth Sailing for Weather Forecasting

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Through a cooperative venture with NASA's Stennis Space Center, WorldWinds, Inc., developed a unique weather and wave vector map using space-based radar satellite information and traditional weather observations. Called WorldWinds, the product provides accurate, near real-time, high-resolution weather forecasts. It was developed for commercial and scientific users. In addition to weather forecasting, the product's applications include maritime and terrestrial transportation, aviation operations, precision farming, offshore oil and gas operations, and coastal hazard response support. Target commercial markets include the operational maritime and aviation communities, oil and gas providers, and recreational yachting interests. Science applications include global long-term prediction and climate change, land-cover and land-use change, and natural hazard issues. Commercial airlines have expressed interest in the product, as it can provide forecasts over remote areas. WorldWinds, Inc., is currently providing its product to commercial weather outlets.

  4. International Space Weather Initiative (ISWI)

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Davila, Joseph M.

    2010-01-01

    The International Space Weather Initiative (ISWI) is an international scientific program to understand the external drivers of space weather. The science and applications of space weather has been brought to prominence because of the rapid development of space based technology that is useful for all human beings. The ISWI program has its roots in the successful International Heliophysical Year (IHY) program that ran during 2007 - 2009. The primary objective of the ISWI program is to advance the space weather science by a combination of instrument deployment, analysis and interpretation of space weather data from the deployed instruments in conjunction with space data, and communicate the results to the public and students. Like the IHY, the ISWI will be a grass roots organization with key participation from national coordinators in cooperation with an international steering committee. This talk outlines the ISWI program including its organization and proposed activities.

  5. A Sensitive Cloud Chamber without Radioactive Sources

    ERIC Educational Resources Information Center

    Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

    2012-01-01

    We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

  6. AWE: Aviation Weather Data Visualization

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly; Lodha, Suresh K.

    2001-01-01

    The two official sources for aviation weather reports both require the pilot to mentally visualize the provided information. In contrast, our system, Aviation Weather Environment (AWE) presents aviation specific weather available to pilots in an easy to visualize form. We start with a computer-generated textual briefing for a specific area. We map this briefing onto a grid specific to the pilot's route that includes only information relevant to his flight route that includes only information relevant to his flight as defined by route, altitude, true airspeed, and proposed departure time. By modifying various parameters, the pilot can use AWE as a planning tool as well as a weather briefing tool.

  7. Accelerated life test of sputtering and anode deposit spalling in a small mercury ion thruster

    NASA Technical Reports Server (NTRS)

    Power, J. L.

    1975-01-01

    Tantalum and molybdenum sputtered from discharge chamber components during operation of a 5 centimeter diameter mercury ion thruster adhered much more strongly to coarsely grit blasted anode surfaces than to standard surfaces. Spalling of the sputtered coating did occur from a coarse screen anode surface but only in flakes less than a mesh unit long. The results were obtained in a 200 hour accelerated life test conducted at an elevated discharge potential of 64.6 volts. The test approximately reproduced the major sputter erosion and deposition effects that occur under normal operation but at approximately 75 times the normal rate. No discharge chamber component suffered sufficient erosion in the test to threaten its structural integrity or further serviceability. The test indicated that the use of tantalum-surfaced discharge chamber components in conjunction with a fine wire screen anode surface should cure the problems of sputter erosion and sputtered deposits spalling in long term operation of small mercury ion thrusters.

  8. Cold-Weather Sports and Your Family

    MedlinePlus

    ... Videos for Educators Search English Español Cold-Weather Sports and Your Family KidsHealth / For Parents / Cold-Weather ... kids while being active. Types of Cold-Weather Sports Skiing, snowboarding, ice skating, and snowshoeing are just ...

  9. ... AND HERE COMES THE WEATHER - Austrian TV and radio weather news in the eye of the public

    NASA Astrophysics Data System (ADS)

    Keul, A.; Holzer, A. M.; Wostal, T.

    2010-09-01

    Media weather reports as the main avenue of meteorological and climatological information to the general public have always been in the focus of critical investigation. Former research found that although weather reports are high-interest topics, the amount of information recalled by non-experts is rather low, and criticized this. A pilot study (Keul et al., 2009) by the Salzburg University in cooperation with ORF, the Austrian Broadcasting Corporation, used historic radio files on a fair-weather and a storm situation. It identified the importance of intelligible wording of the weather forecast messages for lay people. Without quality control, weather information can stimulate rumours, false comfort or false alarms. More qualitative and experimental research, also on TV weather, seems justified. This need for further research was addressed by a second and larger field experiment in the spring of 2010. The survey took place in Salzburg City, Austria, with a quota sample of about 90 lay persons. This time TV and radio weather reports were used and a more realistic listening and viewing situation was created by presenting the latest weather forecasts of the given day to the test persons in the very next hours after originally broadcasting them. It asked lay people what they find important in the weather reports and what they remember for their actual next-day use. Reports of a fairweather prognosis were compared with a warning condition. The weather media mix of the users was explored. A second part of the study was a questionnaire which tested the understanding of typical figures of speech used in weather forecasts or even meteorological terms, which might also be important for fully understanding the severe weather warnings. This leads to quantitative and qualitative analysis from which the most important and unexpected results are presented. Short presentation times (1.5 to 2 minutes) make Austrian radio and TV weather reports a narrow compromise between general

  10. Development of sputtered techniques for thrust chambers

    NASA Technical Reports Server (NTRS)

    Mullaly, J. R.; Hecht, R. J.; Schmid, T. E.; Torrey, C. T.

    1975-01-01

    Techniques and materials were developed and evaluated for the fabrication and coating of advanced, long life, regeneratively cooled thrust chambers. Materials were analyzed as fillers for sputter application of OFHC copper as a closeout layer to channeled inner structures; of the materials evaluated, aluminum was found to provide the highest bond strength and to be the most desirable for chamber fabrication. The structures and properties were investigated of thick sputtered OFHC copper, 0.15 Zr-Cu, Al2O3,-Cu, and SiC-Cu. Layered structures of OFHC copper and 0.15 Zr-Cu were investigated as means of improving chamber inner wall fatigue life. The evaluation of sputtered Ti-5Al-2.5Sn, NASA IIb-11, aluminum and Al2O3-Al alloys as high strength chamber outer jackets was performed. Techniques for refurbishing degraded thrust chambers with OFHC copper and coating thrust chambers with protective ZrO2 and graded ZrO2-copper thermal barrier coatings were developed.

  11. Sequential Notch activation regulates ventricular chamber development

    PubMed Central

    D'Amato, Gaetano; Luxán, Guillermo; del Monte-Nieto, Gonzalo; Martínez-Poveda, Beatriz; Torroja, Carlos; Walter, Wencke; Bochter, Matthew S.; Benedito, Rui; Cole, Susan; Martinez, Fernando; Hadjantonakis, Anna-Katerina; Uemura, Akiyoshi; Jiménez-Borreguero, Luis J.; de la Pompa, José Luis

    2016-01-01

    Ventricular chambers are essential for the rhythmic contraction and relaxation occurring in every heartbeat throughout life. Congenital abnormalities in ventricular chamber formation cause severe human heart defects. How the early trabecular meshwork of myocardial fibres forms and subsequently develops into mature chambers is poorly understood. We show that Notch signalling first connects chamber endocardium and myocardium to sustain trabeculation, and later coordinates ventricular patterning and compaction with coronary vessel development to generate the mature chamber, through a temporal sequence of ligand signalling determined by the glycosyltransferase manic fringe (MFng). Early endocardial expression of MFng promotes Dll4–Notch1 signalling, which induces trabeculation in the developing ventricle. Ventricular maturation and compaction require MFng and Dll4 downregulation in the endocardium, which allows myocardial Jag1 and Jag2 signalling to Notch1 in this tissue. Perturbation of this signalling equilibrium severely disrupts heart chamber formation. Our results open a new research avenue into the pathogenesis of cardiomyopathies. PMID:26641715

  12. Benign Weather Modification,

    DTIC Science & Technology

    1997-05-01

    with respect to weather modification. Publicizing these efforts is necessary in order to eliminate all traces of " cloak and dagger " efforts tainting...theater, the Japanese used the weather to conceal their approach to the Hawaiian Islands, enhancing their surprise attack on Pearl Harbor. There... attack is different than previous researcher goals. Therefore, future experiments would have to be tailored for the new objective of hiding military

  13. Comparison of Weather Shows in Eastern Europe

    NASA Astrophysics Data System (ADS)

    Najman, M.

    2009-09-01

    Comparison of Weather Shows in Eastern Europe Television weather shows in Eastern Europe have in most cases in the high graphical standard. There is though a wast difference in duration and information content in the weather shows. There are few signs and regularities by which we can see the character of the weather show. The main differences are mainly caused by the income structure of the TV station. Either it is a fully privately funded TV relying on the TV commercials income. Or it is a public service TV station funded mainly by the national budget or fixed fee structure/tax. There are wast differences in duration and even a graphical presentation of the weather. Next important aspect is a supplier of the weather information and /or the processor. Shortly we can say, that when the TV show is produced by the national met office, the TV show consists of more scientific terms, synoptic maps, satellite imagery, etc. If the supplier is the private meteorological company, the weather show is more user-friendly, laical with less scientific terms. We are experiencing a massive shift in public weather knowledge and demand for information. In the past, weather shows consisted only of maps with weather icons. In todaýs world, even the laic weather shows consist partly of numerical weather model outputs - they are of course designed to be understandable and graphically attractive. Outputs of the numerical weather models used to be only a part of daily life of a professional meteorologist, today they are common part of life of regular people. Video samples are a part of this presentation.

  14. Note: The design of thin gap chamber simulation signal source based on field programmable gate array.

    PubMed

    Hu, Kun; Lu, Houbing; Wang, Xu; Li, Feng; Liang, Futian; Jin, Ge

    2015-01-01

    The Thin Gap Chamber (TGC) is an important part of ATLAS detector and LHC accelerator. Targeting the feature of the output signal of TGC detector, we have designed a simulation signal source. The core of the design is based on field programmable gate array, randomly outputting 256-channel simulation signals. The signal is generated by true random number generator. The source of randomness originates from the timing jitter in ring oscillators. The experimental results show that the random number is uniform in histogram, and the whole system has high reliability.

  15. Note: The design of thin gap chamber simulation signal source based on field programmable gate array

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

    Hu, Kun; Wang, Xu; Li, Feng

    The Thin Gap Chamber (TGC) is an important part of ATLAS detector and LHC accelerator. Targeting the feature of the output signal of TGC detector, we have designed a simulation signal source. The core of the design is based on field programmable gate array, randomly outputting 256-channel simulation signals. The signal is generated by true random number generator. The source of randomness originates from the timing jitter in ring oscillators. The experimental results show that the random number is uniform in histogram, and the whole system has high reliability.

  16. A Severe Weather Laboratory Exercise for an Introductory Weather and Climate Class Using Active Learning Techniques

    ERIC Educational Resources Information Center

    Grundstein, Andrew; Durkee, Joshua; Frye, John; Andersen, Theresa; Lieberman, Jordan

    2011-01-01

    This paper describes a new severe weather laboratory exercise for an Introductory Weather and Climate class, appropriate for first and second year college students (including nonscience majors), that incorporates inquiry-based learning techniques. In the lab, students play the role of meteorologists making forecasts for severe weather. The…

  17. Weathering of stony meteorites in Antarctica

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1986-01-01

    Weathering produces undesirable physical, chemical, and isotopic changes that might disturb the records of cosmochemical evolution that are sought in meteorites. Meteorites are physically disintegrated by crack propagation phenomena, including ice riving and secondary mineral riving, and are probably abraded by wind that is laden with ice crystals or dust particles. Chemical weathering proceeds by oxidation, hydration, carbonation, and solution and produces a variety of secondary minerals and mineraloids. Differential weathering under freezing conditions is discussed, as well as, the mineralogy of weathering products. Furthermore, the use of Antarctic alteration of meteorites could be used as an excellent analog for weathering on Mars or on cometary bodies.

  18. HIGH ENERGY PARTICLE ACCELERATOR

    DOEpatents

    Courant, E.D.; Livingston, M.S.; Snyder, H.S.

    1959-04-14

    An improved apparatus is presented for focusing charged particles in an accelerator. In essence, the invention includes means for establishing a magnetic field in discrete sectors along the path of moving charged particles, the magnetic field varying in each sector in accordance with the relation. B = B/ sub 0/ STAln (r-r/sub 0/)/r/sub 0/!, where B/sub 0/ is the value of the magnetic field at the equilibrium orbit of radius r/sub 0/ of the path of the particles, B equals the magnetic field at the radius r of the chamber and n equals the magnetic field gradient index, the polarity of n being abruptly reversed a plurality of times as the particles travel along their arcuate path. With this arrangement, the particles are alternately converged towards the axis of their equillbrium orbit and diverged therefrom in successive sectors with a resultant focusing effect.

  19. Enhanced Weathering Strategies for Stabilizing Climate and Averting Ocean Acidification - Supplementary Information

    NASA Technical Reports Server (NTRS)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2015-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m(exp. -2) yr (exp -1)) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  20. Engaging Earth- and Environmental-Science Undergraduates Through Weather Discussions and an eLearning Weather Forecasting Contest

    NASA Astrophysics Data System (ADS)

    Schultz, David M.; Anderson, Stuart; Seo-Zindy, Ryo

    2013-06-01

    For students who major in meteorology, engaging in weather forecasting can motivate learning, develop critical-thinking skills, improve their written communication, and yield better forecasts. Whether such advances apply to students who are not meteorology majors has been less demonstrated. To test this idea, a weather discussion and an eLearning weather forecasting contest were devised for a meteorology course taken by third-year undergraduate earth- and environmental-science students. The discussion consisted of using the recent, present, and future weather to amplify the topics of the week's lectures. Then, students forecasted the next day's high temperature and the probability of precipitation for Woodford, the closest official observing site to Manchester, UK. The contest ran for 10 weeks, and the students received credit for participation. The top students at the end of the contest received bonus points on their final grade. A Web-based forecast contest application was developed to register the students, receive their forecasts, and calculate weekly standings. Students who were successful in the forecast contest were not necessarily those who achieved the highest scores on the tests, demonstrating that the contest was possibly testing different skills than traditional learning. Student evaluations indicate that the weather discussion and contest were reasonably successful in engaging students to learn about the weather outside of the classroom, synthesize their knowledge from the lectures, and improve their practical understanding of the weather. Therefore, students taking a meteorology class, but not majoring in meteorology, can derive academic benefits from weather discussions and forecast contests. Nevertheless, student evaluations also indicate that better integration of the lectures, weather discussions, and the forecasting contests is necessary.

  1. Measurement of the Hadronic Charm Production Cross-Section in a High Resolution Streamer Chamber Experiment

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

    Tzeng, Liang

    1984-05-01

    Hadronic production of charmed particles in association with muons from semileptonic decay or. these short lived particles has been observed in a high resolution streamer cham her experiment performed at Fermi National Accelerator Laboratory in 1982. The incident beam was a collimated high energy neutron beam with an average energy or 280 Gev. The streamer cham her was triggered on the detection or the prom pt muon from the charm decay. Two toroids were installed at the downstream end or the muon spectrometer for analyzing the muon momentum. In the operation of the streamer chamber, we achieved a streamer size or 50 μm and a run track width or 120 μm in space. The streamer chamber optical system had a demagnification factor of about 1.5 from space to film. The minimum separation between two measurable tracks was about 150 μm on the film. With a special miss-distance analysis or the streamer chamber pictures. 17.32 ± 4.73 charm signal events were obtained. Using the assumption ofmore » $$A^{2/3}$$ dependenre for the production cross section and several different $$D-\\bar{D}$$ production models, the nucleonnucleon charm production cross section, averaged over the neutron spectrum, is estimated to be between 13 to 20 μb (with the average value equal to 17.69 ± 6.80 μb).« less

  2. An experimental study of recombination and polarity effect in a set of customized plane parallel ionization chambers.

    PubMed

    Kron, T; McNiven, A; Witruk, B; Kenny, M; Battista, J

    2006-12-01

    Plane parallel ionization chambers are an important tool for dosimetry and absolute calibration of electron beams used for radiotherapy. Most dosimetric protocols require corrections for recombination and polarity effects, which are to be determined experimentally as they depend on chamber design and radiation quality. Both effects were investigated in electron beams from a linear accelerator (Varian 21CD) for a set of four tissue equivalent plane parallel ionization chambers customized for the present research by Standard Imaging (Madison WI). All four chambers share the same design and air cavity dimensions, differing only in the diameter of their collecting electrode and the corresponding width of the guard ring. The diameters of the collecting electrodes were 2 mm, 4 mm, 10 mm and 20 mm. Measurements were taken using electron beams of nominal energy 6 to 20 MeV in a 10 cm x 10 cm field size with a SSD of 100 cm at various depths in a Solid Water slab phantom. No significant variation of recombination effect was found with radiation quality, depth of measurement or chamber design. However, the polarity effect exceeded 5% for the chambers with small collecting electrode for an effective electron energy below 4 MeV at the point of measurement. The magnitude of the effect increased with decreasing electron energy in the phantom. The polarity correction factor calculated following AAPM protocol TG51 ranged from approximately 1.00 for the 20.0 mm chamber to less than 0.95 for the 2 mm chamber at 4.1 cm depth in a electron beam of nominally 12 MeV. By inverting the chamber it could be shown that the polarity effect did not depend on the polarity of the electrode first traversed by the electron beam. Similarly, the introduction of an air gap between the overlying phantom layer and the chambers demonstrated that the angular distribution of the electrons at the point of measurement had a lesser effect on the polarity correction than the electron energy itself. The

  3. Enhancing the Awareness of the Interaction of the Space Weather and Public: Some Case Studies in Turkey

    NASA Astrophysics Data System (ADS)

    Tulunay, Y.; Tulunay, E.; Kocabas, Z.; Altuntas, E.; Yapici, T.; Senalp, E. T.; Hippler, R.

    2009-04-01

    Tour-Mobile Bus 5. Rocket / balloon launch participation for European web quiz winner and journalists 6. Space Weather / Solar / Aurora / Rocket / Balloon movie production for TV 7. Space Weather / Sun /Heliospheric public science festival & public fair in Schwerin castle (main SWEETS festival during ESW 2007) 8. Space Weather telescope video link with Australian (Antarctic Mawson station) and Japanese locations for Schwerin castle festival (no. 7 deliverable) 9. Space Weather planetarium show in Poland, Finland, France and Portugal (4 new languages) 10. Updated Space Weather / Solar CD-Rom / DVD in 7 new languages, poster / flyer 11. Cosmic ray spark chambers 12. Space Weather storm forecast map 13. Mirror system for solar movie 14. FP6 SWEETS / IHY / COST 724 Case Sub-project: "I LOVE MY SUN" (An outreach Activity in Turkey: The Space Weather and the Sun as conceived by the School Children of age 7-11) 15. Press Releases 16. FP6 SWEETS Related Art 17. Turkish Translations in IHY and COST webpages 18. Impact of the SWEETS References Tulunay Y. (2007), FP6 SWEETS (SSA) Activity Report of the Participant No. 16: the METU in Ankara, Türkiye, 31 December 2007, www.ae.metu.edu.tr/~cost.

  4. Weatherization Works--Summary of Findings from the Retrospective Evaluation of the U.S. DOE's Weatherization Assistance Program

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

    Tonn, Bruce Edward; Carroll, David; Pigg, Scott

    This report presents a summary of the studies and analyses that compose the retrospective evaluation of the U.S. Department of Energy s low-income Weatherization Assistance Program (WAP). WAP provides grants to Grantees (i.e., states) that then provide grants to Subgrantees (i.e., local weatherization agencies) to weatherize low-income homes. This evaluation focused on the WAP Program Year 2008. The retrospective evaluation produced twenty separate reports, including this summary. Four separate reports address the energy savings, energy cost savings, and cost effectiveness of WAP across four housing types: single family, mobile home, small multifamily, and large multifamily. Other reports address the environmentalmore » emissions, macroeconomic, and health and household-related benefits attributable to WAP, and characterize the program, its recipients, and those eligible for the program. Major field studies are also summarized, including a major indoor air quality study and a follow-up ventilation study, an in-depth in-field assessment of weatherization work and quality, and a study that assesses reasons for variations in energy savings across homes. Results of surveys of weatherization staff, occupants, occupants satisfaction with weatherization services provided, and weatherization trainees are summarized. Lastly, this report summarizes a set of fifteen case studies of high-performing and unique local weatherization agencies.« less

  5. Planetary Space Weather

    NASA Astrophysics Data System (ADS)

    Grande, M.

    2012-04-01

    Invited Talk - Space weather at other planets While discussion of space weather effects has so far largely been confined to the near-Earth environment, there are significant present and future applications to the locations beyond, and to other planets. Most obviously, perhaps, are the radiation hazards experienced by astronauts on the way to, and on the surface of, the Moon and Mars. Indeed, the environment experienced by planetary spacecraft in transit and at their destinations is of course critical to their design and successful operation. The case of forthcoming missions to Jupiter and Europa is an exreme example. Moreover, such craft can provide information which in turn increases our understanding of geospace. Indeed, space weather may be a significant factor in the habitability of other solar system and extrasolar planets, and the ability of life to travel between them.

  6. Vacuum chamber with a supersonic flow aerodynamic window

    DOEpatents

    Hanson, Clark L.

    1982-01-01

    A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  7. Vacuum chamber with a supersonic-flow aerodynamic window

    DOEpatents

    Hanson, C.L.

    1980-10-14

    A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  8. Acute shallowing of the anterior chamber.

    PubMed Central

    Mapstone, R

    1981-01-01

    In aging eyes phenylephrine drops have no significant effect on the depth of the anterior chamber, whereas pilocarpine drops produce a significant shallowing. If both drugs are instilled simultaneously, a significantly greater decrease in anterior chamber depth occurs. The effect is seen in normal, glaucomatous, and hypertensive eyes, and in eyes with shallow anterior chambers. It did not occur in eyes that had had an iridectomy. During the course of a positive provocative test an acute reduction in anterior depth occurs which is reversed when the angle opens and pressure returns to normal levels. It is concluded that the depth of the anterior chamber is not a static dimension but that changes can occur which are rapid and transient. The mechanism of shallowing and deepening depends on an increase or a decrease in the pupil block force. It is a necessary consequence too that eyes with nonshallow anterior chambers can get closed-angle glaucoma and that this possibility cannot be detected by a conventional gonioscopic approach. PMID:6455153

  9. Overview of Goal 1 (Establish Benchmarks for Space-Weather Events) of the National Space Weather Action Plan

    NASA Astrophysics Data System (ADS)

    Jonas, S.; Murtagh, W. J.; Clarke, S. W.

    2017-12-01

    The National Space Weather Action Plan identifies approximately 100 distinct activities across six strategic goals. Many of these activities depend on the identification of a series of benchmarks that describe the physical characteristics of space weather events on or near Earth. My talk will provide an overview of Goal 1 (Establish Benchmarks for Space-Weather Events) of the National Space Weather Action Plan which will provide an introduction to the panel presentations and discussions.

  10. 14 CFR 121.101 - Weather reporting facilities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Weather reporting facilities. 121.101... § 121.101 Weather reporting facilities. (a) Each certificate holder conducting domestic or flag operations must show that enough weather reporting services are available along each route to ensure weather...

  11. 14 CFR 121.101 - Weather reporting facilities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Weather reporting facilities. 121.101... § 121.101 Weather reporting facilities. (a) Each certificate holder conducting domestic or flag operations must show that enough weather reporting services are available along each route to ensure weather...

  12. 14 CFR 121.101 - Weather reporting facilities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Weather reporting facilities. 121.101... § 121.101 Weather reporting facilities. (a) Each certificate holder conducting domestic or flag operations must show that enough weather reporting services are available along each route to ensure weather...

  13. 14 CFR 121.101 - Weather reporting facilities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Weather reporting facilities. 121.101... § 121.101 Weather reporting facilities. (a) Each certificate holder conducting domestic or flag operations must show that enough weather reporting services are available along each route to ensure weather...

  14. 14 CFR 121.101 - Weather reporting facilities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Weather reporting facilities. 121.101... § 121.101 Weather reporting facilities. (a) Each certificate holder conducting domestic or flag operations must show that enough weather reporting services are available along each route to ensure weather...

  15. Outgassing measurement of the aluminum alloy UHV chamber

    NASA Technical Reports Server (NTRS)

    Miyamoto, M.; Itoh, T.; Komaki, S.; Narushima, K.; Ishimaru, H.

    1986-01-01

    A large vacuum chamber (580 mm diameter) was fabricated from an aluminum alloy surface treated by a special process normally used on small chambers. The chamber was tested unbaked and baked at various temperatures, pressures, and holding periods. The chamber was filled with N2 gas, and the outgassing rate was measured after one hour. Then the ultimate pressure was measured. Outgassing rates for baked and unbaked groups were compared. It is concluded that the same surface treatment technique can be used on both large and small chambers produced by the same special extrusion process.

  16. Rainmakers: why bad weather means good productivity.

    PubMed

    Lee, Jooa Julia; Gino, Francesca; Staats, Bradley R

    2014-05-01

    People believe that weather conditions influence their everyday work life, but to date, little is known about how weather affects individual productivity. Contrary to conventional wisdom, we predict and find that bad weather increases individual productivity and that it does so by eliminating potential cognitive distractions resulting from good weather. When the weather is bad, individuals appear to focus more on their work than on alternate outdoor activities. We investigate the proposed relationship between worse weather and higher productivity through 4 studies: (a) field data on employees' productivity from a bank in Japan, (b) 2 studies from an online labor market in the United States, and (c) a laboratory experiment. Our findings suggest that worker productivity is higher on bad-, rather than good-, weather days and that cognitive distractions associated with good weather may explain the relationship. We discuss the theoretical and practical implications of our research. (c) 2014 APA, all rights reserved.

  17. Effects of Background Pressure on Relativistic Laser-Plasma Interaction Ion Acceleration

    NASA Astrophysics Data System (ADS)

    Peterson, Andrew; Orban, C.; Feister, S.; Ngirmang, G.; Smith, J. T.; Klim, A.; Frische, K.; Morrison, J.; Chowdhury, E.; Roquemore, W. M.

    2016-10-01

    Typically, ultra-intense laser-accelerated ion experiments are carried out under high-vacuum conditions and with a repetition rate up to several shots per day. Looking to the future there is a need to perform these experiments with a much larger repetition rate. A continuously flowing liquid target is more suitable than a solid target for this purpose. However liquids vaporize below their vapor pressure, and the experiment cannot be performed under high-vacuum conditions. The effects of this non-negligible high chamber pressure acceleration of charged particles is not yet well understood. We investigate this phenomena using Particle-in-Cell simulations, exploring the effect of the background pressure on the accelerated ion spectrum. Experiments in this regime are being performed at the Air Force Research Laboratory at Wright-Patterson Air Force Base. This research was sponsored by the Quantum and Non-Equilibrium Processes Division of the Air Force Office of Scientific Research, under the management of Dr. Enrique Parra, Program Manager and significant support from the DOD HPCMP Internship Program.

  18. Operational Space Weather Activities in the US

    NASA Astrophysics Data System (ADS)

    Berger, Thomas; Singer, Howard; Onsager, Terrance; Viereck, Rodney; Murtagh, William; Rutledge, Robert

    2016-07-01

    We review the current activities in the civil operational space weather forecasting enterprise of the United States. The NOAA/Space Weather Prediction Center is the nation's official source of space weather watches, warnings, and alerts, working with partners in the Air Force as well as international operational forecast services to provide predictions, data, and products on a large variety of space weather phenomena and impacts. In October 2015, the White House Office of Science and Technology Policy released the National Space Weather Strategy (NSWS) and associated Space Weather Action Plan (SWAP) that define how the nation will better forecast, mitigate, and respond to an extreme space weather event. The SWAP defines actions involving multiple federal agencies and mandates coordination and collaboration with academia, the private sector, and international bodies to, among other things, develop and sustain an operational space weather observing system; develop and deploy new models of space weather impacts to critical infrastructure systems; define new mechanisms for the transition of research models to operations and to ensure that the research community is supported for, and has access to, operational model upgrade paths; and to enhance fundamental understanding of space weather through support of research models and observations. The SWAP will guide significant aspects of space weather operational and research activities for the next decade, with opportunities to revisit the strategy in the coming years through the auspices of the National Science and Technology Council.

  19. KSC Weather and Research

    NASA Technical Reports Server (NTRS)

    Maier, Launa; Huddleston, Lisa; Smith, Kristin

    2016-01-01

    This briefing outlines the history of Kennedy Space Center (KSC) Weather organization, past research sponsored or performed, current organization, responsibilities, and activities, the evolution of weather support, future technologies, and an update on the status of the buoys located offshore of Cape Canaveral Air Force Station and KSC.

  20. Development of time projection chamber for precise neutron lifetime measurement using pulsed cold neutron beams

    NASA Astrophysics Data System (ADS)

    Arimoto, Y.; Higashi, N.; Igarashi, Y.; Iwashita, Y.; Ino, T.; Katayama, R.; Kitaguchi, M.; Kitahara, R.; Matsumura, H.; Mishima, K.; Nagakura, N.; Oide, H.; Otono, H.; Sakakibara, R.; Shima, T.; Shimizu, H. M.; Sugino, T.; Sumi, N.; Sumino, H.; Taketani, K.; Tanaka, G.; Tanaka, M.; Tauchi, K.; Toyoda, A.; Tomita, T.; Yamada, T.; Yamashita, S.; Yokoyama, H.; Yoshioka, T.

    2015-11-01

    A new time projection chamber (TPC) was developed for neutron lifetime measurement using a pulsed cold neutron spallation source at the Japan Proton Accelerator Research Complex (J-PARC). Managing considerable background events from natural sources and the beam radioactivity is a challenging aspect of this measurement. To overcome this problem, the developed TPC has unprecedented features such as the use of polyether-ether-ketone plates in the support structure and internal surfaces covered with 6Li-enriched tiles to absorb outlier neutrons. In this paper, the design and performance of the new TPC are reported in detail.

  1. Note: Small anaerobic chamber for optical spectroscopy

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

    Chauvet, Adrien A. P., E-mail: adrien.chauvet@gmail.com; Chergui, Majed; Agarwal, Rachna

    2015-10-15

    The study of oxygen-sensitive biological samples requires an effective control of the atmosphere in which they are housed. In this aim however, no commercial anaerobic chamber is adequate to solely enclose the sample and small enough to fit in a compact spectroscopic system with which analysis can be performed. Furthermore, spectroscopic analysis requires the probe beam to pass through the whole chamber, introducing a requirement for adequate windows. In response to these challenges, we present a 1 l anaerobic chamber that is suitable for broad-band spectroscopic analysis. This chamber has the advantage of (1) providing access, via a septum, tomore » the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment.« less

  2. 49 CFR 195.224 - Welding: Weather.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions that...

  3. 49 CFR 195.224 - Welding: Weather.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions that...

  4. 49 CFR 195.224 - Welding: Weather.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions that...

  5. 49 CFR 195.224 - Welding: Weather.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions that...

  6. 49 CFR 195.224 - Welding: Weather.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions that...

  7. Economic Value of Weather and Climate Forecasts

    NASA Astrophysics Data System (ADS)

    Katz, Richard W.; Murphy, Allan H.

    1997-06-01

    Weather and climate extremes can significantly impact the economics of a region. This book examines how weather and climate forecasts can be used to mitigate the impact of the weather on the economy. Interdisciplinary in scope, it explores the meteorological, economic, psychological, and statistical aspects of weather prediction. Chapters by area specialists provide a comprehensive view of this timely topic. They encompass forecasts over a wide range of temporal scales, from weather over the next few hours to the climate months or seasons ahead, and address the impact of these forecasts on human behavior. Economic Value of Weather and Climate Forecasts seeks to determine the economic benefits of existing weather forecasting systems and the incremental benefits of improving these systems, and will be an interesting and essential text for economists, statisticians, and meteorologists.

  8. Poster — Thur Eve — 28: Enabling trajectory-based radiotherapy on a TrueBeam accelerator with the Eclipse treatment planning system

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

    Mullins, J; Asiev, K; DeBlois, F

    2014-08-15

    The TrueBeam linear accelerator platform has a developer's mode which permits the user dynamic control over many of the machine's mechanical and radiation systems. Using this research tool, synchronous couch and gantry motion can be programmed to simulate isocentric treatment with a shortened SAD, with benefits such as smaller projected MLC leaf widths and an increased dose rate. In this work, water tank measurements were used to commission a virtual linear accelerator with an 85 cm SAD in Eclipse, from which several arc-based radiotherapy treatments were generated, including an inverse optimized VMAT delivery. For each plan, the pertinent treatment deliverymore » information was extracted from control points specified in the Eclipse-exported DICOM files using the pydicom package in Python, allowing construction of an XML control file. The dimensions of the jaws and MLC positions, defined for an 85 cm SAD in Eclipse, were scaled for delivery on a conventional SAD linear accelerator, and translational couch motion was added as a function of gantry angle to simulate delivery at 85 cm SAD. Ionization chamber and Gafchromic film measurements were used to compare the radiation delivery to dose calculations in Eclipse. With the exception of the VMAT delivery, ionization chamber measurements agreed within 3.3% of the Eclipse calculations. For the VMAT delivery, the ionization chamber was located in an inhomogeneous region, but gamma evaluation of the Gafchromic film plane resulted in a 94.5% passing rate using criteria of 3 mm/3%. The results indicate that Eclipse calculation infrastructure can be used.« less

  9. Numerical simulation of magma chamber dynamics.

    NASA Astrophysics Data System (ADS)

    Longo, Antonella; Papale, Paolo; Montagna, Chiara Paola; Vassalli, Melissa; Giudice, Salvatore; Cassioli, Andrea

    2010-05-01

    Magma chambers are characterized by periodic arrivals of deep magma batches that give origin to complex patterns of magma convection and mixing, and modify the distribution of physical quantities inside the chamber. We simulate the transient, 2D, multi-component homogeneous dynamics in geometrically complex dyke+chamber systems, by means of GALES, a finite element parallel C++ code solving mass, momentum and energy equations for multi-component homogeneous gas-liquid (± crystals) mixtures in compressible-to-incompressible flow conditions. Code validation analysis includes several cases from the classical engineering literature, corresponding to a variety of subsonic to supersonic gas-liquid flow regimes (see http://www.pi.ingv.it/~longo/gales/gales.html). The model allows specification of the composition of the different magmas in the domain, in terms of ten major oxides plus the two volatile species H2O and CO2. Gas-liquid thermodynamics are modeled by using the compositional dependent, non-ideal model in Papale et al. (Chem.. Geol., 2006). Magma properties are defined in terms of local pressure, temperature, and composition including volatiles. Several applications are performed within domains characterized by the presence of one or more magma chambers and one or more dykes, with different geometries and characteristic size from hundreds of m to several km. In most simulations an initial compositional interface is placed at the top of a feeding dyke, or at larger depth, with the deeper magma having a lower density as a consequence of larger volatile content. The numerical results show complex patterns of magma refilling in the chamber, with alternating phases of magma ingression and magma sinking from the chamber into the feeding dyke. Intense mixing takes place in feeding dykes, so that the new magma entering the chamber is always a mixture of the deep and the initially resident magma. Buoyant plume rise occurs through the formation of complex convective

  10. The Garden State Flourishes with Weatherization (New Jersey): Weatherization Assistance Close-Up Fact Sheet

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

    D&R International

    2001-10-10

    New Jersey demonstrates its commitment to technology and efficiency through the Weatherization Program. Weatherization uses advanced technologies and techniques to reduce energy costs for low-income families by increasing the energy efficiency of their homes.

  11. The Weathering of Antarctic Meteorites: Climatic Controls on Weathering Rates and Implications for Meteorite Accumulation

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Akridge, J. M. C.; Sears, D. W. G.; Bland, P. A.

    1995-01-01

    Weathering of meteorites includes a variety of chemical and mineralogical changes, including conversion of metal to iron oxides, or rust. Other changes include the devitrification of glass, especially in fusion crust. On a longer time scale, major minerals such as olivine, pyroxene, and feldspar are partially or wholly converted to various phyllosilicates. The degree of weathering of meteorite finds is often noted using a qualitative system based on visual inspection of hand specimens. Several quantitative weathering classification systems have been proposed or are currently under development. Wlotzka has proposed a classification system based on mineralogical changes observed in polished sections and Mossbauer properties of meteorite powders have also been used. In the current paper, we discuss induced thermoluminescence (TL) as an indicator of degree of weathering of individual meteorites. The quantitative measures of weathering, including induced TL, suffer from one major flaw, namely that their results only apply to small portions of the meteorite.

  12. Making MUSIC: A multiple sampling ionization chamber

    NASA Astrophysics Data System (ADS)

    Shumard, B.; Henderson, D. J.; Rehm, K. E.; Tang, X. D.

    2007-08-01

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. × 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction.

  13. Simple Cloud Chambers Using Gel Ice Packs

    ERIC Educational Resources Information Center

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  14. What is the weather like today

    NASA Astrophysics Data System (ADS)

    Jovic, Sladjana

    2017-04-01

    Meteorology is the study of all changes in the atmosphere that surround the Earth. In this project, students will design and build some of the instruments that meteorologists use and make two school Weather Stations and placed them in different school yards so that results of weather parameters date can be follow during three months and be compared. Poster will present a procedure and a preparation how to work with weather stations that contain 1. Barometer (Air pressure) 2. Rain Gauge (Precipitation) 3. Thermometer (Temperature ) 4. Wind Vane (Wind Direction) By collecting their own data, the students found out more about weather through a process similar to the one that professional meteorologists used. Finally students compared differences between two school weather station and used these results to presented how different places had different climate and how climate changed during the months in a year. This was opportunity for cooperation between students from different schools and different grades when older students from secondary school helped younger student to make their weather station and shared knowledge and experience while they followed weather condition during the project .

  15. A new ring-shaped graphite monitor ionization chamber

    NASA Astrophysics Data System (ADS)

    Yoshizumi, M. T.; Caldas, L. V. E.

    2010-07-01

    A ring-shaped monitor ionization chamber was developed at the Instituto de Pesquisas Energéticas e Nucleares. This ionization chamber presents an entrance window of aluminized polyester foil. The guard ring and collecting electrode are made of graphite coated Lucite plates. The main difference between this new ionization chamber and commercial monitor chambers is its ring-shaped design. The new monitor chamber has a central hole, allowing the passage of the direct radiation beam without attenuation; only the penumbra radiation is measured by the sensitive volume. This kind of ionization chamber design has already been tested, but using aluminium electrodes. By changing the electrode material from aluminium to a graphite coating, an improvement in the chamber response stability was expected. The pre-operational tests, as saturation curve, recombination loss and polarity effect showed satisfactory results. The repeatability and the long-term stability tests were also evaluated, showing good agreement with international recommendations.

  16. Promoted-Combustion Chamber with Induction Heating Coil

    NASA Technical Reports Server (NTRS)

    Richardson, Erin; Hagood, Richard; Lowery, Freida; Herald, Stephen

    2006-01-01

    An improved promoted-combustion system has been developed for studying the effects of elevated temperatures on the flammability of metals in pure oxygen. In prior promoted-combustion chambers, initial temperatures of metal specimens in experiments have been limited to the temperatures of gas supplies, usually near room temperature. Although limited elevated temperature promoted-combustion chambers have been developed using water-cooled induction coils for preheating specimens, these designs have been limited to low-pressure operation due to the hollow induction coil. In contrast, the improved promoted-combustion chamber can sustain a pressure up to 10 kpsi (69 MPa) and, through utilization of a solid induction coil, is capable of preheating a metal specimen up to its melting point [potentially in excess of 2,000 F (approximately equal to 1,100 C)]. Hence, the improved promoted combustion chamber makes a greater range of physical conditions and material properties accessible for experimentation. The chamber consists of a vertical cylindrical housing with an inner diameter of 8 in. (20.32 cm) and an inner height of 20.4 in. (51.81 cm). A threaded, sealing cover at one end of the housing can be unscrewed to gain access for installing a specimen. Inlet and outlet ports for gases are provided. Six openings arranged in a helical pattern in the chamber wall contain sealed sapphire windows for viewing an experiment in progress. The base of the chamber contains pressure-sealed electrical connectors for supplying power to the induction coil. The connectors feature a unique design that prevents induction heating of the housing and the pressure sealing surfaces; this is important because if such spurious induction heating were allowed to occur, chamber pressure could be lost. The induction coil is 10 in. (25.4 cm) long and is fitted with a specimen holder at its upper end. At its lower end, the induction coil is mounted on a ceramic base, which affords thermal insulation to

  17. 36 CFR 910.71 - Weather protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Weather protection. 910.71 Section 910.71 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL... DEVELOPMENT AREA Glossary of Terms § 910.71 Weather protection. Weather protection means a seasonal or...

  18. 36 CFR 910.71 - Weather protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Weather protection. 910.71 Section 910.71 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL... DEVELOPMENT AREA Glossary of Terms § 910.71 Weather protection. Weather protection means a seasonal or...

  19. 36 CFR 910.71 - Weather protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Weather protection. 910.71 Section 910.71 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL... DEVELOPMENT AREA Glossary of Terms § 910.71 Weather protection. Weather protection means a seasonal or...

  20. 36 CFR 910.71 - Weather protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Weather protection. 910.71 Section 910.71 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL... DEVELOPMENT AREA Glossary of Terms § 910.71 Weather protection. Weather protection means a seasonal or...