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Sample records for smog chamber experiments

  1. Dynamic consideration of smog chamber experiments

    Directory of Open Access Journals (Sweden)

    W. K. Chuang

    2017-08-01

    Full Text Available Recent studies of the α-pinene + ozone reaction that address particle nucleation show relatively high molar yields of highly oxidized multifunctional organic molecules with very low saturation concentrations that can form and grow new particles on their own. However, numerous smog-chamber experiments addressing secondary organic aerosol (SOA mass yields, interpreted via equilibrium partitioning theory, suggest that the vast majority of SOA from α-pinene is semivolatile. We explore this paradox by employing a dynamic volatility basis set (VBS model that reproduces the new-particle growth rates observed in the CLOUD experiment at CERN and then modeling SOA mass yield experiments conducted at Carnegie Mellon University (CMU. We find that the base-case simulations do overpredict observed SOA mass but by much less than an equilibrium analysis would suggest; this is because delayed condensation of vapors suppresses the apparent mass yields early in the chamber experiments. We further find that a second VBS model featuring substantial oligomerization of semivolatile monomers can match the CLOUD growth rates with substantially lower SOA mass yields; this is because the lighter monomers have a higher velocity and thus a higher condensation rate for a given mass concentration. The oligomerization simulations are a closer match to the CMU experiments than the base-case simulations, though they overpredict the observations somewhat. However, we also find that if the chemical conditions in CLOUD and the CMU chamber were identical, substantial nucleation would have occurred in the CMU experiments when in fact none occurred. This suggests that the chemical mechanisms differed in the two experiments, perhaps because the high oxidation rates in the SOA formation experiments led to rapid termination of peroxy radical chemistry.

  2. Dynamic consideration of smog chamber experiments

    Science.gov (United States)

    Chuang, Wayne K.; Donahue, Neil M.

    2017-08-01

    Recent studies of the α-pinene + ozone reaction that address particle nucleation show relatively high molar yields of highly oxidized multifunctional organic molecules with very low saturation concentrations that can form and grow new particles on their own. However, numerous smog-chamber experiments addressing secondary organic aerosol (SOA) mass yields, interpreted via equilibrium partitioning theory, suggest that the vast majority of SOA from α-pinene is semivolatile. We explore this paradox by employing a dynamic volatility basis set (VBS) model that reproduces the new-particle growth rates observed in the CLOUD experiment at CERN and then modeling SOA mass yield experiments conducted at Carnegie Mellon University (CMU). We find that the base-case simulations do overpredict observed SOA mass but by much less than an equilibrium analysis would suggest; this is because delayed condensation of vapors suppresses the apparent mass yields early in the chamber experiments. We further find that a second VBS model featuring substantial oligomerization of semivolatile monomers can match the CLOUD growth rates with substantially lower SOA mass yields; this is because the lighter monomers have a higher velocity and thus a higher condensation rate for a given mass concentration. The oligomerization simulations are a closer match to the CMU experiments than the base-case simulations, though they overpredict the observations somewhat. However, we also find that if the chemical conditions in CLOUD and the CMU chamber were identical, substantial nucleation would have occurred in the CMU experiments when in fact none occurred. This suggests that the chemical mechanisms differed in the two experiments, perhaps because the high oxidation rates in the SOA formation experiments led to rapid termination of peroxy radical chemistry.

  3. [Characterization of photochemical smog chamber and initial experiments].

    Science.gov (United States)

    Jia, Long; Xu, Yong-Fu; Shi, Yu-Zhen

    2011-02-01

    A self-made new indoor environmental chamber facility for the study of atmospheric processes leading to the formation of ozone and secondary organic aerosols has been introduced and characterized. The characterization experiments include the measurements of wall effects for reactive species and the determination of chamber dependent * OH radical sources by CO-NO(x) irradiation experiments. Preliminary ethene-NO(x) and benzene-NO(x) experiments were conducted as well. The results of characterization experiments show that the wall effects for O3 and NO2 in a new reactor are not obvious. Relative humidity has a great effect on the wall losses in the old reactor, especially for O3. In the old reactor, the rate constant for O3 wall losses is obtained to be 1.0 x 10(-5) s(-1) (RH = 5%) and 4.0 x10(-5) s(-1) (RH = 91%), whereas for NO2, it is 1.0 x 10(-6) s(-1) (RH = 5%) and 0.6 x 10(-6) s(-1) (RH = 75%). The value for k(NO2 --> HONO) determined by CO-NO(x) irradiation experiments is (4.2-5.2) x 10(-5) s(-1) and (2.3-2.5) x 10(-5) s(-1) at RH = 5% and RH 75% -77%, respectively. The average *OH concentration is estimated to be (2.1 +/- 0.4) x 10(6) molecules/cm3 by using a reaction rate coefficient of CO and * OH. The sensitivity of chamber dependent auxiliary reactions to the O3 formation is discussed. Results show that NO2 --> HONO has the greatest impact on the O3 formation during the initial stage, N2O5 + H2O --> 2HNO3 has a minus effect to maximum O3 concentration, and that the wall losses of both O3 and NO2 have little impact on the O3 formation. The results from the ethene-NO(x) and benzene-NO(x) experiments are in good agreement with those from the MCM simulation, which reflects that the facility for the study of the formation of secondary pollution of ozone and secondary organic aerosols is reliable. This demonstrates that our facility can be further used in the deep-going study of chemical processes in the atmosphere.

  4. Exploring the Liquefied Petroleum Gas - Ozone Relation in Guadalajara, Mexico, by Smog Chamber Experiments

    OpenAIRE

    Jaimes-López, José Luis; Sandoval-Fernández, Julio; Zambrano-García, Angel

    2005-01-01

    It has been hypothesized that liquefied petroleum gas (LPG) emissions can increase substantially the formation of ozone (O3) in the ambient air. We tested experimentally such hypothesis in Guadalajara's downtown by captive-air irradiation (CAI) techniques. During November 1997-January, 1998, morning ambient air samples were confined in outdoor smog chambers and subjected to the following treatments: 35% addition of commercial LPG or one out of two mixtures of major LPG compounds (propane/buta...

  5. Acid aerosol measurement method intercomparisons: An outdoor smog chamber study

    International Nuclear Information System (INIS)

    Ellestad, T.G.; Barnes, H.M.; Kamens, R.M.; McDow, S.R.; Sickles, J.E. II; Hodson, L.L.; Waldman, J.M.; Randtke, S.J.; Lane, D.D.; Springston, S.R.; Koutrakis, P.; Thurston, G.D.

    1991-01-01

    A workshop on the measurement of acid aerosols indicated that the sampling methods in use had not been intercompared. Following two laboratory pilot studies, EPA sponsored tests in an outdoor smog chamber with a variety of test aerosols, including sulfuric acid only, photochemical smog with added sulfuric acid, photo-chemical smog with added sulfuric acid and dust, and dust followed by photochemical smog with added sulfuric acid. Two experiments of each type were conducted. Six groups, several of which were active in ambient acid aerosol measurements, participated by operating duplicate samplers for each experiment. Five groups employed a similar method, in which ammonia is removed from the sample stream by diffusion, particles are removed by Teflon filter, and hydrogen ion on the Teflon filter is determined by pH electrode. However, differences existed in the method's implementation among groups in physical design, flow rate, procedures, and analysis. The sixth group's method did not use a diffusion denuder for ammonia and had several other important differences. Besides hydrogen ion, seven other species were reported by most of the groups, including particle phase sulfate, ammonium, and nitrate, and gas phase sulfur dioxide, ammonia, nitric acid, and nitrous acid. Results of the inter-comparison will be presented

  6. Evaluation of one-dimensional and two-dimensional volatility basis sets in simulating the aging of secondary organic aerosol with smog-chamber experiments.

    Science.gov (United States)

    Zhao, Bin; Wang, Shuxiao; Donahue, Neil M; Chuang, Wayne; Hildebrandt Ruiz, Lea; Ng, Nga L; Wang, Yangjun; Hao, Jiming

    2015-02-17

    We evaluate the one-dimensional volatility basis set (1D-VBS) and two-dimensional volatility basis set (2D-VBS) in simulating the aging of SOA derived from toluene and α-pinene against smog-chamber experiments. If we simulate the first-generation products with empirical chamber fits and the subsequent aging chemistry with a 1D-VBS or a 2D-VBS, the models mostly overestimate the SOA concentrations in the toluene oxidation experiments. This is because the empirical chamber fits include both first-generation oxidation and aging; simulating aging in addition to this results in double counting of the initial aging effects. If the first-generation oxidation is treated explicitly, the base-case 2D-VBS underestimates the SOA concentrations and O:C increase of the toluene oxidation experiments; it generally underestimates the SOA concentrations and overestimates the O:C increase of the α-pinene experiments. With the first-generation oxidation treated explicitly, we could modify the 2D-VBS configuration individually for toluene and α-pinene to achieve good model-measurement agreement. However, we are unable to simulate the oxidation of both toluene and α-pinene with the same 2D-VBS configuration. We suggest that future models should implement parallel layers for anthropogenic (aromatic) and biogenic precursors, and that more modeling studies and laboratory research be done to optimize the "best-guess" parameters for each layer.

  7. USING 14 C METHODOLOGY IN SMOG CHAMBER RESEARCH

    Science.gov (United States)

    Smog chambers are large enclosures (~ 10-200 m3) that are used to perform laboratory simulations of atmospheric reactions. By dealing with simple systems in which the number of reactants is limited and the conditions are strictly controlled, insights on how reactions ...

  8. Assessing the influence of NOx concentrations and relative humidity on secondary organic aerosol yields from α-pinene photo-oxidation through smog chamber experiments and modelling calculations

    Science.gov (United States)

    Stirnweis, Lisa; Marcolli, Claudia; Dommen, Josef; Barmet, Peter; Frege, Carla; Platt, Stephen M.; Bruns, Emily A.; Krapf, Manuel; Slowik, Jay G.; Wolf, Robert; Prévôt, Andre S. H.; Baltensperger, Urs; El-Haddad, Imad

    2017-04-01

    Secondary organic aerosol (SOA) yields from the photo-oxidation of α-pinene were investigated in smog chamber (SC) experiments at low (23-29 %) and high (60-69 %) relative humidity (RH), various NOx / VOC ratios (0.04-3.8) and with different aerosol seed chemical compositions (acidic to neutralized sulfate-containing or hydrophobic organic). A combination of a scanning mobility particle sizer and an Aerodyne high-resolution time-of-flight aerosol mass spectrometer was used to determine SOA mass concentration and chemical composition. We used a Monte Carlo approach to parameterize smog chamber SOA yields as a function of the condensed phase absorptive mass, which includes the sum of OA and the corresponding bound liquid water content. High RH increased SOA yields by up to 6 times (1.5-6.4) compared to low RH. The yields at low NOx / VOC ratios were in general higher compared to yields at high NOx / VOC ratios. This NOx dependence follows the same trend as seen in previous studies for α-pinene SOA. A novel approach of data evaluation using volatility distributions derived from experimental data served as the basis for thermodynamic phase partitioning calculations of model mixtures in this study. These calculations predict liquid-liquid phase separation into organic-rich and electrolyte phases. At low NOx conditions, equilibrium partitioning between the gas and liquid phases can explain most of the increase in SOA yields observed at high RH, when in addition to the α-pinene photo-oxidation products described in the literature, fragmentation products are added to the model mixtures. This increase is driven by both the increase in the absorptive mass and the solution non-ideality described by the compounds' activity coefficients. In contrast, at high NOx, equilibrium partitioning alone could not explain the strong increase in the yields with RH. This suggests that other processes, e.g. reactive uptake of semi-volatile species into the liquid phase, may occur and be

  9. Interferences of commercial NO2 instruments in the urban atmosphere and in a smog chamber

    Directory of Open Access Journals (Sweden)

    J. Kleffmann

    2012-01-01

    Full Text Available Reliable measurements of atmospheric trace gases are necessary for both, a better understanding of the chemical processes occurring in the atmosphere, and for the validation of model predictions. Nitrogen dioxide (NO2 is a toxic gas and is thus a regulated air pollutant. Besides, it is of major importance for the oxidation capacity of the atmosphere and plays a pivotal role in the formation of ozone and acid precipitation. Detection of NO2 is a difficult task since many of the different commercial techniques used are affected by interferences. The chemiluminescence instruments that are used for indirect NO2 detection in monitoring networks and smog chambers use either molybdenum or photolytic converters and are affected by either positive (NOy or negative interferences (radical formation in the photolytic converter. Erroneous conclusions on NO2 can be drawn if these interferences are not taken into consideration. In the present study, NO2 measurements in the urban atmosphere, in a road traffic tunnel and in a smog-chamber using different commercial techniques, i.e. chemiluminescence instruments with molybdenum or photolytic converters, a Luminol based instrument and a new NO2-LOPAP, were compared with spectroscopic techniques, i.e. DOAS and FTIR. Interferences of the different instruments observed during atmospheric measurements were partly characterised in more detail in the smog chamber experiments. Whereas all the commercial instruments showed strong interferences, excellent agreement was obtained between a new NO2-LOPAP instrument and the FTIR technique for the measurements performed in the smog chamber.

  10. Modelling winter organic aerosol at the European scale with CAMx: evaluation and source apportionment with a VBS parameterization based on novel wood burning smog chamber experiments

    Science.gov (United States)

    Ciarelli, Giancarlo; Aksoyoglu, Sebnem; El Haddad, Imad; Bruns, Emily A.; Crippa, Monica; Poulain, Laurent; Äijälä, Mikko; Carbone, Samara; Freney, Evelyn; O'Dowd, Colin; Baltensperger, Urs; Prévôt, André S. H.

    2017-06-01

    We evaluated a modified VBS (volatility basis set) scheme to treat biomass-burning-like organic aerosol (BBOA) implemented in CAMx (Comprehensive Air Quality Model with extensions). The updated scheme was parameterized with novel wood combustion smog chamber experiments using a hybrid VBS framework which accounts for a mixture of wood burning organic aerosol precursors and their further functionalization and fragmentation in the atmosphere. The new scheme was evaluated for one of the winter EMEP intensive campaigns (February-March 2009) against aerosol mass spectrometer (AMS) measurements performed at 11 sites in Europe. We found a considerable improvement for the modelled organic aerosol (OA) mass compared to our previous model application with the mean fractional bias (MFB) reduced from -61 to -29 %. We performed model-based source apportionment studies and compared results against positive matrix factorization (PMF) analysis performed on OA AMS data. Both model and observations suggest that OA was mainly of secondary origin at almost all sites. Modelled secondary organic aerosol (SOA) contributions to total OA varied from 32 to 88 % (with an average contribution of 62 %) and absolute concentrations were generally under-predicted. Modelled primary hydrocarbon-like organic aerosol (HOA) and primary biomass-burning-like aerosol (BBPOA) fractions contributed to a lesser extent (HOA from 3 to 30 %, and BBPOA from 1 to 39 %) with average contributions of 13 and 25 %, respectively. Modelled BBPOA fractions were found to represent 12 to 64 % of the total residential-heating-related OA, with increasing contributions at stations located in the northern part of the domain. Source apportionment studies were performed to assess the contribution of residential and non-residential combustion precursors to the total SOA. Non-residential combustion and road transportation sector contributed about 30-40 % to SOA formation (with increasing contributions at urban and near

  11. An historical experiment: Los Angeles smog evolution observed by blimp.

    Science.gov (United States)

    Hidy, G M

    2018-02-12

    Observations of smog over the Los Angeles Basin (LAB) links high oxidant mixing ratios with poor visibility, sometimes smog by blimp in a Lagrangian-like format. The experiment on September 6, 1973, demonstrated that a blimp could travel with the wind across the LAB, observing ozone (O 3 ) and precursors, and particles of different size ranges. These included condensation nuclei (CN) concentrations dominated by particles of ≤ 0.1 µm diameter and light scattering coefficient (b sc ) representing mainly particles of 0.1-2.0 µm diameter. The results indicated a pollutant variation similar to that measured at a fixed site. Ozone was produced in an air mass, reaching a maximum of ~400 ppb in the presence of nitrogen oxides (NO x ) and nonmethane hydrocarbons (NMHCs), then declined. Although the photochemistry was developing, b sc grew with O 3 mixing ratio to a quasi-steady state at ~9-10 × 10 -4  m -1 , decreasing in value much later with decease in O 3 . The light scattering coefficient was found to be positively associated with the O 3 mixing ratio, whereas CN concentrations were negatively proportional to O 3 mixing ratio. The blimp experiment was supported with aircraft vertical profiles and ground-level observations from a mobile laboratory. The blimp flight obtained combined gas and particle changes aloft that could not be obtained by ground or fixed-wing aircraft measurements alone. The experiment was partially successful in achieving a true Lagrangian characterization of smog chemistry in a constrained or defined "open" air mass. The Los Angeles experiment demonstrated the use of a blimp as a platform for measurement of air pollution traveling with an air mass across an urban area. The method added unique data showing the relationship between photochemical smog chemistry and aerosol dynamics in smog. The method offers an alternative to reliance on smog chamber and modeling observations to designing air quality management strategies for reactive

  12. [Studies of ozone formation potentials for benzene and ethylbenzene using a smog chamber and model simulation].

    Science.gov (United States)

    Jia, Long; Xu, Yong-Fu

    2014-02-01

    Ozone formation potentials from irradiations of benzene-NO(x) and ethylbenzene-NO(x) systems under the conditions of different VOC/NO(x) ratios and RH were investigated using a characterized chamber and model simulation. The repeatability of the smog chamber experiment shows that for two sets of ethylbenzene-NO(x) irradiations with similar initial concentrations and reaction conditions, such as temperature, relative humidity and relative light intensity, the largest difference in O3 between two experiments is only 4% during the whole experimental run. On the basis of smog chamber experiments, ozone formation of photo-oxidation of benzene and ethylbenzene was simulated in terms of the master chemical mechanism (MCM). The peak ozone values for benzene and ethylbenzene simulated by MCM are higher than the chamber data, and the difference between the MCM-simulated results and chamber data increases with increasing RH. Under the conditions of sunlight irradiations, with benzene and ethylbenzene concentrations being in the range of (10-50) x 10(-9) and NO(x) concentrations in the range of (10-100) x 10(-9), the 6 h ozone contributions of benzene and ethylbenzene were obtained to be (3.1-33) x 10(-9) and (2.6-122) x 10(-9), whereas the peak O3 contributions of benzene and ethylbenzene were (3.5-54) x 10(-9) and (3.8-164) x 10(-9), respectively. The MCM-simulated maximum incremental reactivity (MIR) values for benzene and ethylbenzene were 0.25/C and 0.97/C (per carbon), respectively. The maximum ozone reactivity (MOR) values for these two species were obtained to be 0.73/C and 1.03/C, respectively. The MOR value of benzene from MCM is much higher than that obtained by carter from SAPRC, indicating that SAPRC may underestimate the ozone formation potential of benzene.

  13. SMOG CHAMBERS: A TOOL TO EXAMINE EFFECTS OF PHOTOCHEMICALLY AGED AIR POLLUTANTS ON BIOLOGICAL SYSTEMS

    Science.gov (United States)

    Irradiative exposure chambers or 'Smog chambers' have been used at the University of North Carolina for over 30 years to study photochemically active mixtures of volatile organic compounds and their transformation products (a significant sub-set of Hazardous Air Pollutants, HAPs)...

  14. Smog chamber studies on the air chemistry of biogenic hydrocarbons in the presence of ozone, NOx and SO2

    International Nuclear Information System (INIS)

    Nolting, F.; Zetzsch, C.

    1990-01-01

    The influence of SO 2 on the photochemical degradation processes of the biogenic hydrocarbon α-pinene was studied with respect to the present forest decline. For that purpose premixed air was irradiated with simulated sunlight in laboratory experiments using a modified smog chamber. The performance of a novel semi continuous analyzer for H 2 SO 4 /sulfate was tested for smog chamber studies of the transformation of SO 2 to sulfuric acid and sulfur containing aerosol. An influence of SO 2 on the formation of ozone was not detected. The rates of degradation cannot be described by gas phase reactions alone, and, in addition, they are faster in the presence of humidity. Depending on humidity, 30-50% of the consumed SO 2 can be recovered in the suspended aerosol. In the presence of 60% relative humidity the nearly exclusive product is sulfur aerosol that needs further characterization. (orig.) With 9 figs., 42 refs [de

  15. [Smog chamber simulation of ozone formation from atmospheric photooxidation of propane].

    Science.gov (United States)

    Huang, Li-hua; Mo, Chuang-rong; Xu, Yong-fu; Jia, Long

    2012-08-01

    Atmospheric photochemical reactions of propane and NO, were simulated with a self-made smog chamber. The effects of relative humidity (RH) and [C3H8]0/[NOx]0 ratio on ozone formation were studied. The results showed that both the maximum ozone concentration and the maximum value of incremental reactivity (IRmax) of propane decreased linearly with increasing RH. Under lower RH conditions, the occurrence time of peak ozone concentration was about 22 h after the beginning of reaction, and IRmax varied from 0.0231 to 0.0391, while under higher RH conditions the occurrence time of peak ozone concentration was 16 h, and IRmax ranged from 0.0172 to 0.0320. During the 20 h of reaction, within the first 12 h RH did not significantly affect the yield of acetone, whereas after 12 h the lower RH condition could lead to relatively greater amount of acetone. During the first 4-20 h of experiments, acetone concentrations ranged from 153 x 10(-9) to 364 x 10(-9) at 17% RH and from 167 x 10(-9) to 302 x 10(-9) at 62% RH, respectively. Maximum ozone concentrations decreased with increasing [C3H8]0/[NOx]0 ratio and a better negative linear relationship between them was obtained under the lower RH conditions. The smog chamber data and the results from simulation of the C3H8-NOx reactions using the sub-mechanism of MCM were compared, and a significant deviation was found between these two results.

  16. Effects of relative humidity on the characterization of a photochemical smog chamber.

    Science.gov (United States)

    Hu, Gaoshuo; Xu, Yongfu; Jia, Long

    2011-01-01

    Water vapor plays an important role in many atmospheric chemical reactions. A self-made indoor environmental smog chamber was used to investigate the effects of relative humidity (RH) on its characterization, which included the wall effects of reactive species such as 03 and NOx, and the determination of chamber-dependent OH radicals in terms of CO-NOx irradiation experiments. Results showed that the rate constant of O3 wall losses increased with increasing RH, and that their relationship was linearly significant. Although RH affected the rate constant of NOx wall losses, their relationship was not statistically significant. Background air generated a small amount of ozone at both high and low RH. When RH varied from 5% to 79%, the apparent rate constant kNO2-->HONO for the conversion of NO2 into gas phase HONO was estimated in the range of 0.70 x 10(-3)-2.5 x 10(-3) min(-1). A linear relationship between kNO2-->HONO and RH was obtained as kNO2-->HONO (10(-3) min(-1)) = -0.0255RH + 2.64, with R2 and P value being 0.978 and < 0.01. To our knowledge, this is the first report on their relationship. The generation mechanism for HONO and OH was also discussed in this work.

  17. Constraining a hybrid volatility basis-set model for aging of wood-burning emissions using smog chamber experiments: a box-model study based on the VBS scheme of the CAMx model (v5.40)

    Science.gov (United States)

    Ciarelli, Giancarlo; El Haddad, Imad; Bruns, Emily; Aksoyoglu, Sebnem; Möhler, Ottmar; Baltensperger, Urs; Prévôt, André S. H.

    2017-06-01

    In this study, novel wood combustion aging experiments performed at different temperatures (263 and 288 K) in a ˜ 7 m3 smog chamber were modelled using a hybrid volatility basis set (VBS) box model, representing the emission partitioning and their oxidation against OH. We combine aerosol-chemistry box-model simulations with unprecedented measurements of non-traditional volatile organic compounds (NTVOCs) from a high-resolution proton transfer reaction mass spectrometer (PTR-MS) and with organic aerosol measurements from an aerosol mass spectrometer (AMS). Due to this, we are able to observationally constrain the amounts of different NTVOC aerosol precursors (in the model) relative to low volatility and semi-volatile primary organic material (OMsv), which is partitioned based on current published volatility distribution data. By comparing the NTVOC / OMsv ratios at different temperatures, we determine the enthalpies of vaporization of primary biomass-burning organic aerosols. Further, the developed model allows for evaluating the evolution of oxidation products of the semi-volatile and volatile precursors with aging. More than 30 000 box-model simulations were performed to retrieve the combination of parameters that best fit the observed organic aerosol mass and O : C ratios. The parameters investigated include the NTVOC reaction rates and yields as well as enthalpies of vaporization and the O : C of secondary organic aerosol surrogates. Our results suggest an average ratio of NTVOCs to the sum of non-volatile and semi-volatile organic compounds of ˜ 4.75. The mass yields of these compounds determined for a wide range of atmospherically relevant temperatures and organic aerosol (OA) concentrations were predicted to vary between 8 and 30 % after 5 h of continuous aging. Based on the reaction scheme used, reaction rates of the NTVOC mixture range from 3.0 × 10-11 to 4. 0 × 10-11 cm3 molec-1 s-1. The average enthalpy of vaporization of secondary organic aerosol

  18. Constraining a hybrid volatility basis-set model for aging of wood-burning emissions using smog chamber experiments: a box-model study based on the VBS scheme of the CAMx model (v5.40

    Directory of Open Access Journals (Sweden)

    G. Ciarelli

    2017-06-01

    Full Text Available In this study, novel wood combustion aging experiments performed at different temperatures (263 and 288 K in a ∼ 7 m3 smog chamber were modelled using a hybrid volatility basis set (VBS box model, representing the emission partitioning and their oxidation against OH. We combine aerosol–chemistry box-model simulations with unprecedented measurements of non-traditional volatile organic compounds (NTVOCs from a high-resolution proton transfer reaction mass spectrometer (PTR-MS and with organic aerosol measurements from an aerosol mass spectrometer (AMS. Due to this, we are able to observationally constrain the amounts of different NTVOC aerosol precursors (in the model relative to low volatility and semi-volatile primary organic material (OMsv, which is partitioned based on current published volatility distribution data. By comparing the NTVOC ∕ OMsv ratios at different temperatures, we determine the enthalpies of vaporization of primary biomass-burning organic aerosols. Further, the developed model allows for evaluating the evolution of oxidation products of the semi-volatile and volatile precursors with aging. More than 30 000 box-model simulations were performed to retrieve the combination of parameters that best fit the observed organic aerosol mass and O : C ratios. The parameters investigated include the NTVOC reaction rates and yields as well as enthalpies of vaporization and the O : C of secondary organic aerosol surrogates. Our results suggest an average ratio of NTVOCs to the sum of non-volatile and semi-volatile organic compounds of ∼ 4.75. The mass yields of these compounds determined for a wide range of atmospherically relevant temperatures and organic aerosol (OA concentrations were predicted to vary between 8 and 30 % after 5 h of continuous aging. Based on the reaction scheme used, reaction rates of the NTVOC mixture range from 3.0 × 10−11 to 4. 0 × 10−11 cm3 molec−1 s−1

  19. Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber

    Directory of Open Access Journals (Sweden)

    M. A. Miracolo

    2011-05-01

    Full Text Available Field experiments were performed to investigate the effects of photo-oxidation on fine particle emissions from an in-use CFM56-2B gas turbine engine mounted on a KC-135 Stratotanker airframe. Emissions were sampled into a portable smog chamber from a rake inlet installed one-meter downstream of the engine exit plane of a parked and chocked aircraft. The chamber was then exposed to sunlight and/or UV lights to initiate photo-oxidation. Separate tests were performed at different engine loads (4, 7, 30, 85 %. Photo-oxidation created substantial secondary particulate matter (PM, greatly exceeding the direct PM emissions at each engine load after an hour or less of aging at typical summertime conditions. After several hours of photo-oxidation, the ratio of secondary-to-primary PM mass was on average 35 ± 4.1, 17 ± 2.5, 60 ± 2.2, and 2.7 ± 1.1 for the 4, 7, 30, and 85 % load experiments, respectively. The composition of secondary PM formed strongly depended on load. At 4 % load, secondary PM was dominated by secondary organic aerosol (SOA. At higher loads, the secondary PM was mainly secondary sulfate. A traditional SOA model that accounts for SOA formation from single-ring aromatics and other volatile organic compounds underpredicts the measured SOA formation by ~60 % at 4 % load and ~40 % at 85 % load. Large amounts of lower-volatiliy organic vapors were measured in the exhaust; they represent a significant pool of SOA precursors that are not included in traditional SOA models. These results underscore the importance of accounting for atmospheric processing when assessing the influence of aircraft emissions on ambient PM levels. Models that do not account for this processing will likely underpredict the contribution of aircraft emissions to local and regional air pollution.

  20. Knudsen cell and smog chamber study of the heterogeneous uptake of sulfur dioxide on Chinese mineral dust.

    Science.gov (United States)

    Zhou, Li; Wang, Weigang; Gai, Yanbo; Ge, Maofa

    2014-12-01

    The heterogeneous uptake processes of sulfur dioxide on two types of Chinese mineral dust (Inner Mongolia desert dust and Xinjiang sierozem) were investigated using both Knudsen cell and smog chamber system. The temperature dependence of the uptake coefficients was studied over a range from 253 to 313 K using the Knudsen cell reactor, the initial uptake coefficients decreased with the increasing of temperature for these two mineral dust samples, whereas the steady state uptake coefficients of the Xinjiang sierozem increased with the temperature increasing, and these temperature dependence functions were obtained for the first time. In the smog chamber experiments at room temperature, the steady state uptake coefficients of SO2 decreased evidently with the increasing of sulfur dioxide initial concentration from 1.72 × 10¹² to 6.15 × 10¹² mol/cm³. Humid air had effect on the steady state uptake coefficients of SO₂onto Inner Mongolia desert dust. Consequences about the understanding of the uptake processes onto mineral dust samples and the environmental implication were also discussed. Copyright © 2014. Published by Elsevier B.V.

  1. Smog chamber study on the evolution of fume from residential coal combustion.

    Science.gov (United States)

    Geng, Chunmei; Wang, Kun; Wang, Wei; Chen, Jianhua; Liu, Xiaoyu; Liu, Hongjie

    2012-01-01

    Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking, and emit considerable pollutants to the atmosphere because of no treatment of their exhaust, which can result in deteriorating local air quality. In this study, a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation. The real-time emissions revealed that the total hydrocarbon (THC) and CO increased sharply after ignition, and then quickly decreased, indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants. There was evident shoulder peak around 10 min combustion for both THC and CO, revealing the emissions from vitrinite combustion. Additionally, another broad emission peak of CO after 30 min was also observed, which was ascribed to the incomplete combustion of the inertinite. Compared with THC and CO, there was only one emission peak for NOx, SO2 and particular matters at the beginning stage of combustion. The fume evolution with static chamber simulation indicated that evident consumption of SO2 and NOx as well as new particle formation were observed. The consumption rates for SO2 and NOx were about 3.44% hr(-1) and 3.68% hr(-1), the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour, and the increase of the diameter of accumulation mode particles was evident. The addition of isoprene to the diluted mixture of the fume could promote 03 and secondary particle formation.

  2. Effect of hydrocarbons and nitrogen oxides on ozone formation in smog chambers exposed to solar irradiance of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval F, J; Marroquin de la R, O; Jaimes L, J. L; Zuniga L, V. A; Gonzalez O, E; Guzman Lopez-Figueroa, F [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2001-01-01

    Outdoor smog chambers experiments were performed on air to determine the answer of maximum ozone levels, to changes in the initial hydrocarbons, HC, and nitrogen oxide NO{sub x}. These captive-air experiments under natural irradiation were carried out. Typically, eight chambers were filled with Mexico city air in the morning. In some of those chambers, the initial HC and/or Nox concentrations were varied by {+-}25% to {+-}50% by adding various combinations of a mixture of HC, clean air, or NO{sub x} (perturbed chambers). The O{sub 3} and NO{sub x} concentration in each chamber was monitored throughout the day to determine O{sub 3} (max). The initial HC and NO{sub x} concentration effects were determined by comparing the maximum ozone concentrations measured in the perturbed and unperturbed chambers. Ozone isopleths were constructed from the empirical model obtained of measurements of the eight chambers and plotted in a graph whose axe were the initial HC and NO{sub x} values. For the average initial conditions that were measured in Mexico City, it was found that the most efficient strategy to reduce the maximum concentration of O{sub 3} is the one that reduces NO{sub x}. [Spanish] Se realizaron experimentos de camaras de esmog con el aire de la ciudad de Mexico para determinar las respuestas de los niveles maximos de ozono a los cambios en las concentraciones iniciales de hidrocarburos, HC y oxido de nitrogeno, NO{sub x}. Por lo general, se llenaron 8 bolsas con aire matutino de la Ciudad de Mexico. En algunas camaras, las concentraciones iniciales fueron cambiadas de 25% a 50%, anadiendo varias concentraciones de una mezcla de HC, aire limpio y/o NO{sub x}. La concentracion de O{sub 3} y NO{sub x}, en cada camara, fueron monitoreadas a lo largo del dia para determinar el maximo de O{sub 3}. El efecto de los HC y el NO{sub x} fue determinado por comparacion del maximo de ozono formado en las camaras, que fueron perturbadas por adicion o reduccion de HC y/o Nox

  3. SMOG programme version for np (E=1-5 GeV) experiment

    International Nuclear Information System (INIS)

    Kotorobaj, F.

    1975-01-01

    The SMOG program, which can be used for NPD robot scanning in the described experiment, is described. A new modifiaction, set up so as to ensure its reliable use on the CDC-1604A, is considered. The program was designed for and used in processing the np (E=1-5 GeV) experiment. SMOG uses three magnetic tapes at the input (one at the extension) and one at the output containing the assembled collected events. A new SMOG variant with origination of errors according to parity during the recording time is attempted in order to continue to write the given zone five times. A short description of the work with the new SMOG program version is given

  4. Molecular size evolution of oligomers in organic aerosols collected in urban atmospheres and generated in a smog chamber.

    Science.gov (United States)

    Kalberer, Markus; Sax, Mirjam; Samburova, Vera

    2006-10-01

    Only a minor fraction of the total organic aerosol mass can be resolved on a molecular level. High molecular weight compounds in organic aerosols have recently gained much attention because this class of compound potentially explains a major fraction of the unexplained organic aerosol mass. These compounds have been identified with different mass spectrometric methods, and compounds with molecular masses up to 1000 Da are found in secondary organic aerosols (SOA) generated from aromatic and terpene precursors in smog chamber experiments. Here, we apply matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to SOA particles from two biogenic precursors, alpha-pinene and isoprene. Similar oligomer patterns are found in these two SOA systems, but also in SOA from trimethylbenzene, an anthropogenic SOA precursor. However, different maxima molecular sizes were measured for these three SOA systems. While oligomers in alpha-pinene and isoprene have sizes mostly below 600-700 Da, they grow up to about 1000 Da in trimethylbenzene-SOA. The final molecular size of the oligomers is reached early during the particle aging process, whereas other particle properties related to aging, such as the overall acid concentration or the oligomer concentration, increase continuously over a much longer time scale. This kinetic behavior of the oligomer molecular size growth can be explained by a chain growth kinetic regime. Similar oligomer mass patterns were measured in aqueous extracts of ambient aerosol samples (measured with the same technique). Distinct differences between summer and winter were observed. In summer a few single mass peaks were measured with much higher intensity than in winter, pointing to a possible difference in the formation processes of these compounds in winter and summer.

  5. Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments.

    Science.gov (United States)

    Chiappini, L; Perraudin, E; Durand-Jolibois, R; Doussin, J F

    2006-11-01

    A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m3 Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91

  6. Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chiappini, L.; Perraudin, E.; Durand-Jolibois, R.; Doussin, J.F. [Universites Paris, Laboratoire Interuniversitaire des Systemes Atmospheriques, UMR CNRS 7583, Creteil (France)

    2006-11-15

    A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m{sup 3} Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91 < R < 0.98) of the method were both good and detection limits ranged from 1.2 to 6.4 ng for the investigated compounds. (orig.)

  7. Analyzing the Formation, Physicochemical, and Optical Properties of Aging Biomass Burning Aerosol Using an Indoor Smog Chamber

    Science.gov (United States)

    Smith, D. M.; Fiddler, M. N.; Bililign, S.; Spann, M.

    2017-12-01

    Biomass burning (BB) is recognized as one of the largest sources of absorbing aerosols in the atmosphere and significantly influences the radiative properties of the atmosphere. The chemical composition and physical properties of particles evolve during their atmospheric lifetime due to condensation, oxidation reactions, etc., which alters their optical properties. To this end, an indoor smog chamber was constructed to study aging BB aerosol in a laboratory setting. Injections to the chamber, including NOx, O3, and various biogenic and anthropogenic VOCs, can simulate a variety of atmospheric conditions. These components and some of their oxidation products are monitored during the aging process. A tube furnace is used for combustion of biomass to be introduced to the chamber, while size distributions are taken as the aerosol ages. Online measurements of optical properties are determined using a Cavity Ring-down Spectrometry and Integrating Nephelometry system. Chemical properties are measured from samples captured on filters and analyzed using Ultra-Performance Liquid Chromatography coupled in-line to both a Diode Array Detector and High-Resolution Time-of-Flight Mass Spectrometer equipped with electrospray ionization. The measured changes in the optical properties as a function of particle size, aging, and chemical properties are presented for fuel sources used in Africa.

  8. Mutagenicity in Salmonella of a Simulated Urban-Smog Atmosphere Generated Using a Mobile Reaction Chamber

    Science.gov (United States)

    The EPA Mobile Reaction Chamber (MRC) is a 24-foot trailer containing a 14.3-m3 Teflon lined photochemical chamber used to generate simulated urban atmospheres. Photochemistry in the MRC is catalyzed by 120 fluorescent bulbs evenly mixed with black light bulbs and UV bulbs (300 &...

  9. Gas-particle partitioning of semivolatile organic compounds (SOCs) on mixtures of aerosols in a smog chamber.

    Science.gov (United States)

    Chandramouli, Bharadwaj; Jang, Myoseon; Kamens, Richard M

    2003-09-15

    The partitioning behavior of a set of diverse SOCs on two and three component mixtures of aerosols from different sources was studied using smog chamber experimental data. A set of SOCs of different compound types was introduced into a system containing a mixture of aerosols from two or more sources. Gas and particle samples were taken using a filter-filter-denuder sampling system, and a partitioning coefficient Kp was estimated using Kp = Cp/(CgTSP). Particle size distributions were measured using a differential mobility analyzer and a light scattering detector. Gas and particle samples were analyzed using GCMS. The aerosol composition in the chamber was tracked chemically using a combination of signature compounds and the organic matter mass fraction (f(om)) of the individual aerosol sources. The physical nature of the aerosol mixture in the chamber was determined using particle size distributions, and an aggregate Kp was estimated from theoretically calculated Kp on the individual sources. Model fits for Kp showed that when the mixture involved primary sources of aerosol, the aggregate Kp of the mixture could be successfully modeled as an external mixture of the Kp on the individual aerosols. There were significant differences observed for some SOCs between modeling the system as an external and as an internal mixture. However, when one of the aerosol sources was secondary, the aggregate model Kp required incorporation of the secondary aerosol products on the preexisting aerosol for adequate model fits. Modeling such a system as an external mixture grossly overpredicted the Kp of alkanes in the mixture. Indirect evidence of heterogeneous, acid-catalyzed reactions in the particle phase was also seen, leading to a significant increase in the polarity of the resulting aerosol mix and a resulting decrease in the observed Kp of alkanes in the chamber. The model was partly consistent with this decrease but could not completely explain the reduction in Kp because of

  10. Simulation of chamber experiments

    International Nuclear Information System (INIS)

    Ivanov, V.G.

    1981-01-01

    The description of the system of computer simulation of experiments conducted by means of track detectors with film data output is given. Considered is the principle of organization of computer model of the chamber experiment comprising the following stages: generation of events, generation of measurements, ge-- neration of scanning results, generation of distorbions, generated data calibration, filtration, events reconstruction, kinematic identification, total results tape formation, analysis of the results. Generation programs are formed as special RAM-files, where the RAM-file is the text of the program written in FORTRAN and divided into structural elements. All the programs are a ''part of the ''Hydra'' system. The system possibilities are considered on the base of the CDSC-6500 computer. The five-beam event generation, creation data structure for identification and calculation by the kinematic program take about 1s of CDC-6500 computer time [ru

  11. A chromatographic method to analyze products from photo-oxidation of anthropogenic and biogenic mixtures of volatile organic compounds in smog chambers.

    Science.gov (United States)

    Pindado Jiménez, Oscar; Pérez Pastor, Rosa M; Vivanco, Marta G; Santiago Aladro, Manuel

    2013-03-15

    A method for quantifying secondary organic aerosol compounds (SOA) and water soluble secondary organic aerosol compounds (WSOA) produced from photo-oxidation of complex mixtures of volatile organic compounds (VOCs) in smog chambers by gas chromatography/mass spectrometry (GC/MS) has been developed. This method employs a double extraction with water and methanol jointly to a double derivatization with N,O-bis (trimethylsilil) trifluoroacetamide (BSTFA) and O-(2,3,4,5,6)-pentafluorobenzyl-hydroxylamine hydrochloride (PFBHA) followed by an analysis performed by GC/MS. The analytical procedure complements other methodologies because it can analyze SOA and WSOA compounds simultaneously at trace levels. As application, the methodology was employed to quantify the organic composition of aerosols formed in a smog chamber as a result of photo-oxidation of two different mixtures of volatile organic compounds: an anthropogenic mixture and a biogenic mixture. The analytical method allowed us to quantify up to 17 SOA compounds at levels higher than 20 ng m(-3) with reasonable recovery and a precision below 11%. Values found for applicability, selectivity, linearity, precision, recovery, detection limit, quantification limit and sensitivity demonstrated that the methodology can be satisfactorily applied to quantify SOA and WSOA. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Effect of nitrogen oxides (NO and NO2) and toluene on SO2 photooxidation, nucleation and growth: A smog chamber study

    Science.gov (United States)

    Li, Kangwei; Chen, Linghong; White, Stephen J.; Han, Ke; Lv, Biao; Bao, Kaiji; Wu, Xuecheng; Gao, Xiang; Azzi, Merched; Cen, Kefa

    2017-08-01

    The formation and growth of new particles has recently been shown to have a significant influence on Chinese haze pollution, and sulfuric acid has long been recognized as a major contributor to new particle formation. In this study, four comparison groups of experiments related to SO2 photooxidation, as well as aerosol nucleation and growth, have been conducted in the CAPS-ZJU (Complex Air Pollution Study-Zhejiang University) smog chamber. These were conducted either under SO2/NOx or SO2/toluene gas-phase environments in the absence of seed particles. During aerosol nucleation and growth process, several physical properties such as mass, size and effective density were measured simultaneously by Scanning Mobility Particle Sizer (SMPS) and Differential Mobility Analyzer-Aerosol Particle Mass Analyzer-Condensation Particle Counter (DMA-APM-CPC). The effective density of new particles decreased from 1.8 to 1.35 g/cm3 as the particle size increased from 20 to 65 nm. The single particle mass showed good power-law relationship with mobility diameter, with an average mass-mobility exponent of 2.885. A new algorithm and a reference density of 1.38 g/cm3 based on size-resolved single particle mass (SPM) were proposed to calculate the mass concentration of new particles. Two methods based on Log Normal and Max Concentration were applied to derive particle growth rate (GR), and data merging from both methods was implemented to decrease calculation uncertainty. Meanwhile, both continuous nucleation and inhibition of further growth in sub-20 nm size range were observed in different experiments depending on composition, and possible reasons were analyzed. The presence of NO was found to suppress nucleation and subsequent aerosol growth; while the presence of NO2 or toluene promoted it. It was concluded that decreasing NOx (NO or NO2) or increasing toluene may promote SO2 photooxidation, nucleation and subsequent aerosol growth, all of which is significant for deeper

  13. Smog wars

    Energy Technology Data Exchange (ETDEWEB)

    Gospodarek, M.P.

    1979-04-12

    International discussions of transboundary pollution, which have not been able to find a way to effect the agreed-upon principle that no nation should have to suffer another nation's pollution, parallel the smog wars across state boundaries. The states, however, can blame the US Environmental Protection Agency (EPA) as well as each other because of relaxed and unevenly applied standards. Several EPA decisions are cited to illustrate tensions between states and the alienation of the environmental lobby. Of particular concern are the application of smog and ozone standards in rural areas and the effect of offset policy on industrial development.

  14. Smog chamber study on aging of combustion soot in isoprene/SO2/NOx system: Changes of mass, size, effective density, morphology and mixing state

    Science.gov (United States)

    Li, Kangwei; Chen, Linghong; Han, Ke; Lv, Biao; Bao, Kaiji; Wu, Xuecheng; Gao, Xiang; Cen, Kefa

    2017-02-01

    Atmospheric soot aging process is always accompanied by secondary particle formation, which is a comprehensive environmental issue that deserves great attention. On one hand, aging of primary soot could change its own physicochemical properties; on the other hand, complex air pollution caused by pollutant emission from various sources (e.g., vehicle exhausts, coal-fired flue gases and biogenic VOCs emission) may contribute to secondary particle formation onto primary particle surface. In this study, aging of combustion soot in isoprene/SO2/NOx system was investigated under controlled laboratory conditions in several smog chamber experiments. During the evolution of soot, several physical properties such as mass, size, effective density, morphology and mixing state were determined simultaneously by an integrated aerosol analytical system of Scanning Mobility Particle Sizer (SMPS), Differential Mobility Analyzer-Aerosol Particle Mass Analyzer-Condensation Particle Counter (DMA-APM-CPC) and Transmission Electron Microscopy coupled with Energy-dispersive X-ray Spectrometry (TEM/EDX) techniques. Here, based on the experimental results of soot aging under different gas-phase composition and relative humidity (RH), we firstly proposed possible aging pathways of soot in isoprene/SO2/NOx system. A synergetic effect was speculated to exist between SO2 and isoprene on soot aging process, which led to more secondary particle formation. At the same time, TEM/EDX analysis showed that a competitive mechanism between H2SO4(g) and isoprene oxidation vapor may exist: H2SO4(g) firstly condensed onto fresh soot, then an acceleration of isoprene oxidation products formed onto H2SO4 pre-coated soot. In isoprene/SO2/NOx system, high RH conditions could contribute to soot aging and new particle formation. The changes of effective density and dynamic shape factor of soot also indicated that high RH conditions could accelerate soot aging process, and led chain-like soot into more spherical

  15. Radiation smog

    International Nuclear Information System (INIS)

    Spurny, Z.

    1988-01-01

    The principle is described of the production of radiation smog resulting from radioactive emisions. The differences are discussed in the contamination over the territory of Czechoslovakia following the Chernobyl accident. The higher surface contamination of industrial areas recorded after the accident can be explained by electroprecipitation of industrial impurities with the radicals and ions of the radioactive cloud. (E.S.). 3 figs., 16 refs

  16. Volatile Organic Compounds from Logwood Combustion: Emissions and Transformation under Dark and Photochemical Aging Conditions in a Smog Chamber.

    Science.gov (United States)

    Hartikainen, Anni; Yli-Pirilä, Pasi; Tiitta, Petri; Leskinen, Ari; Kortelainen, Miika; Orasche, Jürgen; Schnelle-Kreis, Jürgen; Lehtinen, Kari E J; Zimmermann, Ralf; Jokiniemi, Jorma; Sippula, Olli

    2018-04-17

    Residential wood combustion (RWC) emits high amounts of volatile organic compounds (VOCs) into ambient air, leading to formation of secondary organic aerosol (SOA), and various health and climate effects. In this study, the emission factors of VOCs from a logwood-fired modern masonry heater were measured using a Proton-Transfer-Reactor Time-of-Flight Mass Spectrometer. Next, the VOCs were aged in a 29 m 3 Teflon chamber equipped with UV black lights, where dark and photochemical atmospheric conditions were simulated. The main constituents of the VOC emissions were carbonyls and aromatic compounds, which accounted for 50%-52% and 30%-46% of the detected VOC emission, respectively. Emissions were highly susceptible to different combustion conditions, which caused a 2.4-fold variation in emission factors. The overall VOC concentrations declined considerably during both dark and photochemical aging, with simultaneous increase in particulate organic aerosol mass. Especially furanoic and phenolic compounds decreased, and they are suggested to be the major precursors of RWC-originated SOA in all aging conditions. On the other hand, dark aging produced relatively high amounts of nitrogen-containing organic compounds in both gas and particulate phase, while photochemical aging increased especially the concentrations of certain gaseous carbonyls, particularly acid anhydrides.

  17. Smog signals

    International Nuclear Information System (INIS)

    Fick, S.; Shilts, E.

    2008-01-01

    Nitrogen dioxide (NO 2 ) gas is created when fossil fuels are burned. Hot spots of NO 2 pollution in the troposphere have been identified by researchers at the Royal Netherlands Meteorological Institute. In addition to traffic, the biggest emitters of NO 2 include power plants, heavy industry and oil refineries. The City of Shanghai in China ranks with Los Angeles and Mexico City as the urban areas with the highest NO 2 concentrations in the world. NO 2 combines with particles in the air to create a smog that hangs over larger cities in the summer and plays a role in the production of ground-level ozone, both of which cause a variety of respiratory problems. According to the World Health Organization, such air pollution reduces the life of the average European by 8.6 months. This article included a map indicating NO 2 concentrations around the world. The high levels at Fort McMurray, Alberta can be attributed to the NO 2 emitted by oil sands plants. Individual power plants in Chandrapur and Ramagundam in India and oil refineries around the Persian Gulf also revealed high levels, as did the Highveld area outside of Johannesburg in South Africa, where a number of power plants sit on a plateau. At high altitude, NO 2 lingers longer in the air. In the past decade in Europe and eastern North America, cleaner technology in cars and power plants has led to declines in NO 2 in those regions. However, huge increases in emissions in East Asia mean the air will remain smoggy. 1 fig

  18. Photochemical smog and plants

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, T.

    1974-07-01

    Surveys of plant damage due to photochemical smog are summarized. The components of smog which appear to be responsible for plant damage include ozone and peroxyacyl nitrates. Their phytotoxic effects are much greater than those due to sulfur oxides. Damage surveys since 1970 reveal the following symptoms appearing on herbaceous plants (morning glory, cocks comb, dahlia, knotweed, petunia, chickweed, Welsh onion, spinach, Chinese cabbage, chard, taro): yellowish-white leaf discoloration, white and brown spots on matured leaves, and silvering of the lower surfaces of young leaves. Symptoms which appear on arboraceous plants such as zelkova, poplar, ginkgo, planetree, rose mallow, magnolia, pine tree, and rhododendron include early yellowing and reddening, white or brown spots, and untimely leaf-fall. The above plants are now utilized as indicator plants of photochemical smog. Surveys covering a broad area of Tokyo and three other prefectures indicate that plant damage due to photochemical smog extends to relatively unpolluted areas.

  19. Comparative Toxicity of Simulated Smog Atmospheres in ...

    Science.gov (United States)

    Effects of complex regional multipollutant mixtures on disease expression in susceptible populations are dependent on multiple exposure and susceptibility factors. Differing profiles of ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM), which are key components of smog, and other hazardous pollutants may develop as a result of regional-specific geographic and urban environment characteristics. We investigated the pulmonary effects of two smog mixtures with different compositions in a mouse model of allergic airway disease to determine which source profile had the greatest impact on pulmonary endpoints. A hydrocarbon mixture was combined with NO gas in the presence of UV light in a controlled setting. Simulated smog atmosphere 1 (SSA-1) consisted of concentrations of 1070 µg/m3 secondary organic aerosol (SOA), 0.104 ppm O3, and 0.252 ppm NO2. SSA-2 consisted of a starting concentration of 53 µg/m3 SOA, 0.376 ppm O3, and 0.617 ppm NO2. An increased aerosol concentration was noted in the exposure chamber. Healthy and house dust mite (HDM)-sensitized (allergic) female BALB/cJ mice were exposed 4 hr/day for 1 or 5 days to either smog mixture or clean air. Two days after HDM challenge, airway mechanics were tested in anesthetized ventilated mice. Following methacholine aerosol challenge, increased airway resistance and elastance and a decrease in lung compliance were consistently observed in air- and smog-exposed HDM-allergic groups compared with non-a

  20. Climate chamber for environmentally controlled laboratory airflow experiments.

    Science.gov (United States)

    Even-Tzur, Nurit; Zaretsky, Uri; Grinberg, Orly; Davidovich, Tomer; Kloog, Yoel; Wolf, Michael; Elad, David

    2010-01-01

    Climate chambers have been widely used in in vitro and in vivo studies which require controlled environmental temperature and humidity conditions. This article describes a new desktop climate chamber that was developed for application of respiratory airflows on cultured nasal epithelial cells (NEC) under controlled temperature and humidity conditions. Flow experiments were performed by connecting the climate chamber to an airflow generator via a flow chamber with cultured NEC. Experiments at two controlled climate conditions, 25 degrees C and 40% relative humidity (RH) and 37 degrees C and 80%RH, were conducted to study mucin secretion from the cultures inresponse to the flow. The new climate chamber is a relatively simple and inexpensive apparatus which can easily be connected to any flow system for climate controlled flow experiments. This chamber can be easily adjusted to various in vitro experiments, as well as to clinical studies with animals or human subjects which require controlled climate conditions.

  1. Steering smog prediction

    NARCIS (Netherlands)

    R. van Liere (Robert); J.J. van Wijk (Jack)

    1997-01-01

    textabstractThe use of computational steering for smog prediction is described. This application is representative for many underlying issues found in steering high performance applications: high computing times, large data sets, and many different input parameters. After a short description of the

  2. Menace of smog

    Energy Technology Data Exchange (ETDEWEB)

    Kemmerer, J B

    1959-01-01

    In addition to the loss of human and animal lives, smog causes extensive damage to plant life. With the increasing industrialization of the Los Angeles Basin, air pollution is increasing and causing serious damage to lawns, flowering plants, arable and horticultural crops.

  3. In vitro study of injury on human bronchial epithelial cells caused by gunpowder smog.

    Science.gov (United States)

    Lan, Xiaomei; Feng, Liang; Liu, Yifan; Zhou, Ying; Shao, Lingli; Pang, Wei; Lan, Yating; Wang, Chengbin

    2013-02-01

    Smog inhalation is associated with acute respiratory symptoms in exposed victims. However, despite the evidence from cell injury caused by smog, a stable and practical apparatus used to treat cells with smog is necessary. The aim of this study is to develop a cell research platform of smoke inhalation injury. In the smog-generation device, a wireless electromagnetic heater was used to ignite gunpowder and generate smog. The quality of black powder was checked by the black powder burn rate, and experimental smog was indirectly checked by the amount of cell damage. The temperature and humidity were set at 37 °C ± 1 °C and ≥95% in the smog-cells reaction chamber, respectively. Factors including gunpowder dosages, smog-exposure time, the cell density, modes of exposure, volumes of smog, test durations, volumes of the cell culture medium and combustion velocity were measured. Coefficient variation of different batches of gunpowder and smog were less than 4% and 9%, respectively. With larger gunpowder dosage and longer exposure time, cell injury appeared to increase. When cells were cultured in 4 × 10(4)/well density in culture medium (1 mL/well), exposed to more than 10 L smog with filter screens above plates, detected after 24 h culture in cell incubator and gunpowder burned out within 5 s, smog had the best effect on cell injury. In conclusion, the experimental device can produce test smog stably and safely. The apparatus treating cells with smog can induce cell injury effectively, and the injury is positively correlated with smog concentration and exposure time.

  4. Construction of a drift chamber prototype for the CMS experiment

    International Nuclear Information System (INIS)

    Berdugo, J.; Cerrada, M.; Daniel, M.; Martin, F.; Mocholi, J.; Romero, L.

    1997-01-01

    General design features of a small size drift chamber prototype are described in this report. Prototype construction has taken place at CIEMAT and we explain in detail the assembly procedure. This activity is part of a long term project to mass produce chambers for the muon barrel detector of the CMS experiment which will be installed at CERN. (Author)

  5. Two Simulated-Smog Atmospheres with Different Chemical Compositions Produce Contrasting Mutagenicity in Salmonella.

    Science.gov (United States)

    Ozone (O3), particulate matter (PM), and nitrogen dioxide (NO2) are criteria pollutants used to evaluate air quality. Using a 14.3-m3 Teflon-lined smog chamber with 120 UV bulbs to simulate solar radiation, we generated 2 simulated-smog atmospheres (SSA-1 & SSA-2) with differ...

  6. Parallel Plate Chambers and their possible use in LHC experiments

    International Nuclear Information System (INIS)

    Arefiev, A.; Bencze, Gy.L.; Bizzeti, A.; Choumilov, E.; Civinini, C.; D'Alessandro, R.; Dajko, G.; Fenyvesi, A.; Ferrando, A.; Fouz, M.C.; Iglesias, A.; Ivochkin, V.; Maggi, F.; Malinin, A.; Martinez-Laso, L.; Meschini, M.; Molnar, J.; Pojidaev, V.; Szoncso, F.; Wulz, C.E.

    1995-01-01

    Present status of Parallel Plate Chambers (PPC) is reviewed. After a description of this detector, results from tests concerning PPC efficiency uniformity, radiation hardness, and behaviour in electromagnetic calorimetry are presented. Some possible utilizations in LHC experiments are mentioned. (orig.)

  7. Tropospheric Ozone and Photochemical Smog

    Science.gov (United States)

    Sillman, S.

    2003-12-01

    emitted species, in a process that is driven by sunlight and is accelerated by warm temperatures. This smog is largely the product of gasoline-powered engines (especially automobiles), although coal-fired industry can also generate photochemical smog. The process of photochemical smog formation was first identified by Haagen-Smit and Fox (1954) in association with Los Angeles, a city whose geography makes it particularly susceptible to this type of smog formation. Sulfate aerosols and organic particulates are often produced concurrently with ozone, giving rise to a characteristic milky-white haze associated with this type of air pollution.Today ozone and particulates are recognized as the air pollutants that are most likely to affect human health adversely. In the United States, most major metropolitan areas have periodic air pollution events with ozone in excess of government health standards. Violations of local health standards also occur in major cities in Canada and in much of Europe. Other cities around the world (especially Mexico City) also experience very high ozone levels. In addition to urban-scale events, elevated ozone occurs in region-wide events in the eastern USA and in Western Europe, with excess ozone extending over areas of 1,000 km2 or more. Ozone plumes of similar extent are found in the tropics (especially in Central Africa) at times of high biomass burning (e.g., Jenkins et al., 1997; Chatfield et al., 1998). In some cases ozone associated with biomass burning has been identified at distances up to 104 km from its sources (Schultz et al., 1999).Ozone also has a significant impact on the global troposphere, and ozone chemistry is a major component of global tropospheric chemistry. Global background ozone concentrations are much lower than urban or regional concentrations during pollution events, but there is evidence that the global background has increased as a result of human activities (e.g., Wang and Jacob, 1998; Volz and Kley, 1988). A rise in

  8. Simulations of smog-chamber experiments using the two-dimensional volatility basis set: linear oxygenated precursors.

    Science.gov (United States)

    Chacon-Madrid, Heber J; Murphy, Benjamin N; Pandis, Spyros N; Donahue, Neil M

    2012-10-16

    We use a two-dimensional volatility basis set (2D-VBS) box model to simulate secondary organic aerosol (SOA) mass yields of linear oxygenated molecules: n-tridecanal, 2- and 7-tridecanone, 2- and 7-tridecanol, and n-pentadecane. A hybrid model with explicit, a priori treatment of the first-generation products for each precursor molecule, followed by a generic 2D-VBS mechanism for later-generation chemistry, results in excellent model-measurement agreement. This strongly confirms that the 2D-VBS mechanism is a predictive tool for SOA modeling but also suggests that certain important first-generation products for major primary SOA precursors should be treated explicitly for optimal SOA predictions.

  9. The health policy implications of individual adaptive behavior responses to smog pollution in urban China.

    Science.gov (United States)

    Ban, Jie; Zhou, Lian; Zhang, Yi; Brooke Anderson, G; Li, Tiantian

    2017-09-01

    Smog pollution is a serious public health issue in urban China, where it is associated with public health through a range of respiratory and cardiovascular illnesses. Despite the negative health impacts of smog pollution, individual adaptive behaviors are poorly understood. This knowledge gap hinders the development of effective public policy to support and encourage the adoption of individual adaptive and mitigating behaviors to smog pollution. A questionnaire survey of 1141 randomly sampled individuals in a typical PM 2.5 -polluted Chinese city was designed to establish smog concerns and behavior changes during smog events. The results demonstrate a variety of behavior responses associated with risk perception, experience of smog, age, and gender of respondents. An understanding of these variations is critical to the development of effective public policy and ultimately to the improvement of public health in cities affected by smog. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The drift chamber system of the MEG experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Malte, E-mail: malte.hildebrandt@psi.c [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2010-11-01

    The MEG experiment searches for the lepton flavour violating decay {mu}{yields}e{gamma} and is aiming for a sensitivity of 10{sup -13} in the branching ratio in order to probe new physics beyond the standard model. The experiment is located at the Paul Scherrer Institut (PSI) in Switzerland, where one of the world's most intensive surface muon beams is located. Physics data taking started in September 2008. The drift chamber system is part of the innovative positron spectrometer of the MEG experiment and consists of 16 drift chamber modules. The system is designed to ensure precision measurement of 52.8 MeV/c positrons. Design, construction, geometrical alignment and performance of the drift chamber system are presented.

  11. A Pedagogical Experiment Using Bubble Chamber Pictures

    CERN Multimedia

    2002-01-01

    We have taken, in October 1981, 20.000 pictures of proton-proton interactions at 5 GeV/c in order to get some clean elastic events which can be easily studied by high school students. The purpose is to illustrate, by actual measurements of these real events, some basic concepts of relativistic mechanisms. This experiment will be an extension of our previous one, performed with HBC 2m events taken at 2 GeV/c. In 1980, all french lycees were provided with large size reproduction of HBC 2m events. Before distribution they were carefully selected and severe kinematical cuts were made. The students measured track curvatures by template, and checked the necessity and the validity of relativistic mechanics by computing the energy balance using non-relativistic and relativistic formulae. No practical problems have been encountered during this experiment and the pedagogical results are encouraging. This new sample of events will be interesting because they are relativistic than the old ones although with the same curv...

  12. Drift chamber readout system of the DIRAC experiment

    CERN Document Server

    Afanasiev, L G

    2002-01-01

    A drift chamber readout system of the DIRAC experiment at CERN is presented. The system is intended to read out the signals from planar chambers operating in a high current mode. The sense wire signals are digitized in the 16-channel time-to-digital converter boards which are plugged in the signal plane connectors. This design results in a reduced number of modules, a small number of cables and high noise immunity. The system has been successfully operating in the experiment since 1999.

  13. Dynamical Networks for Smog Pattern Analysis

    OpenAIRE

    Zong, Linqi; Gong, Xinyi; Zhu, Jia

    2015-01-01

    Smog, as a form of air pollution, poses as a serious problem to the environment, health, and economy of the world[1-4] . Previous studies on smog mostly focused on the components and the effects of smog [5-10]. However, as the smog happens with increased frequency and duration, the smog pattern which is critical for smog forecast and control, is rarely investigated, mainly due to the complexity of the components, the causes, and the spreading processes of smog. Here we report the first analys...

  14. Drift Chambers Simulations in BM@N Experiment

    Directory of Open Access Journals (Sweden)

    Fedorišin Ján

    2016-01-01

    Full Text Available Drift chambers constitute an important part of the tracking system of the BM@N experiment designed to study the production of baryonic matter at the Nuclotron energies. GEANT programming package is employed to investigate the drift chamber response to particles produced in relativistic nuclear collisions of C+C nuclei, which are simulated by the UrQMD and LAQGSM Monte Carlo generators. These simulations are combined with the first BM@N experimental data to estimate particle track coordinates and their errors.

  15. Smog Yellows Taj Mahal

    Science.gov (United States)

    2007-01-01

    Built as a monument to the favorite wife of the Mughal Emperor Shah Jahan, the Taj Mahal has watched over the city of Agra, India, since the mid-seventeenth century with its pillars of gleaming white marble. By the spring of 2007, however, one of the world's most visited landmarks was turning yellow, and a panel of India's parliament had little trouble identifying the culprit: pollution. The panel blamed particles of soot and dirt suspended high in the atmosphere for the Taj Mahal's dinginess. The Taj Mahal's home, Agra, sits not far from the base of the Himalaya, and smog regularly collects along the southern side of the mountain range. On May 16, 2007, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image of the area around Agra, India. The closeup image shows the immediate vicinity of the Taj Majal. The larger image shows the surrounding area. In both pictures, dingy, gray-beige haze obscures the satellite's view of the land surface. India had tried to minimize the adverse impact of air pollution on the famous landmark. According to the BBC, in the late 1990s, India's Supreme Court ordered the closure of thousands of iron foundries and kilns that had belched smoke near the monument. Many of the 3 million tourists who visited the Taj Majal each year approached the monument on horse-drawn carriages or battery-operated buses as fossil-fuel-powered vehicles could not drive within 2 kilometers (1.5 miles). Since those efforts have failed to save the Taj Majal's complexion, Indian officials have considered applying a cleansing mud pack to the monument's surface to draw out the dirt. As India industrializes, smog results, and the Taj Mahal's gleaming whiteness is only one casualty. Pollution has been blamed for a decrease in Indian rice harvests, which had soared during the 'Green Revolution' of the 1960s and 1970s. Haze and dust also appear to bring on the region's monsoon rains earlier than normal.

  16. Chinese haze versus Western smog: lessons learned.

    Science.gov (United States)

    Zhang, Junfeng Jim; Samet, Jonathan M

    2015-01-01

    Air pollution in many Chinese cities has been so severe in recent years that a special terminology, the "Chinese haze", was created to describe China's air quality problem. Historically, the problem of Chinese haze has developed several decades after Western high-income countries have significantly improved their air quality from the smog-laden days in the early- and mid-20(th) century. Hence it is important to provide a global and historical perspective to help China combat the current air pollution problems. In this regard, this article addresses the followings specific questions: (I) What is the Chinese haze in comparison with the sulfurous (London-type) smog and the photochemical (Los Angeles-type) smog? (II) How does Chinese haze fit into the current trend of global air pollution transition? (III) What are the major mitigation measures that have improved air quality in Western countries? and (IV) What specific recommendations for China can be derived from lessons and experiences from Western countries?

  17. Study on a drift chamber for high energy experiments

    International Nuclear Information System (INIS)

    Puget, Maria Augusta Constante

    1993-01-01

    This work deals with the studies of a multiwire gaseous detector operating as a drift chamber, which will be part of the SELEX spectrometer of the experiment Fermilab E781. A prototype was designed to be built and tested at IFUSP. Results are shown of the analysis of data taken with another similar detector whose construction and test were done at Fermilab, with the aim of studying its characterization and performance. (author)

  18. Toronto Smog Summit Report Card

    International Nuclear Information System (INIS)

    2001-01-01

    This 'report card' provides a summary of actions taken, and progress achieved by the federal government, the provincial government and the City of Toronto, respectively, in response to various previous commitments regarding air quality, sustainable transportation, climate and atmospheric research, investing in green infrastructure (federal government), environmental assessment regulations, transboundary air pollution, improved monitoring and reporting regulations. Ratings also cover efforts in imposing emissions caps on the electric industry, emissions reduction trading system, toll-free public air pollution hotline, regulation of ozone depleting substances (provincial government), public education campaign on smog reduction, energy efficiency initiatives, corporate smog alert response plan, and a number of other environmental issues (City of Toronto)

  19. Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

    Science.gov (United States)

    C. J. Hennigan; M. A. Miracolo; G. J. Engelhart; A. A. May; A. A. Presto; T. Lee; A. P. Sullivan; G. R. McMeeking; H. Coe; C. E. Wold; W.-M. Hao; J. B. Gilman; W. C. Kuster; J. de Gouw; B. A. Schichtel; J. L. Collett; S. M. Kreidenweis; A. L. Robinson

    2011-01-01

    Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA) during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III). We investigated emissions from 12 different...

  20. The Time Projection Chamber for the ALICE Experiment

    CERN Document Server

    Lippmann, C

    2008-01-01

    The Time Projection Chamber of the ALICE Experiment has been installed in the experimental setup in the underground area at the Large Hadron Collider at CERN in Geneva. The Alice TPC ReadOut (ALTRO) chip implements intelligent signal processing on the Front-End-Electronics. During the years of 2007 and 2008 commissioning and calibration of the TPC have been carried out with cosmic rays, radioactive Krypton isotopes and with tracks produced by a UV laser system. In addition to these in this publication we present first results on energy loss measurements and on the momentum resolution.

  1. The Time Projection Chamber of the HARP Experiment

    CERN Document Server

    Lundborg, A

    2002-01-01

    The hadron production experiment HARP aims to measure hadron collision cross sections with a 2-15 GeV particle beam and several targets. This energy regime is in a borderline zone between the low energy region dominated by resonance formation and the high energy domain where perturbative Quantum Chromo Dynamics is applicable. The emphasis of this master thesis is put on the HARP central tracker, the Time Projection Chamber (TPC). In the thesis work, Finite Element Method computations of the electric field in critical regions of the TPC have been performed to provide design input concerning the electrostatic configuration of the field cages and of the wire chamber. A first step in the chain of reconstruction of the information produced by the detector is the equalisation and monitoring of about 4000 analogue signals. An algorithm that processes the raw digitised signals, filters out electronics noise and extracts the pad gain from signal distributions has been produced and analysed for this purpose. The algori...

  2. All-metal vacuum chamber for the ZT-40 experiment

    International Nuclear Information System (INIS)

    Dike, R.S.; Downing, J.N.

    1981-10-01

    We discuss the design and fabrication of the all-metal vacuum chamber presently in use in the ZT-40 device. ZT-40 is the current experiment in the Los Alamos Reversed-Field Pinch (RFP) program. The new vessel, which replaces a ceramic one, is made of Inconel 625 and has major and minor diameters of 228 cm and 40 cm, respectively. It consists of 24 convoluted and straight sections welded into a single toroidal geometry. Presented are several design features showing diagnostic and vacuum port tubulations and thermal-electrical insulation isolating the unit from its conducting shell. We also discuss fabrication techniques and our procedure for cleaning and heat treatment designed to eliminate residual gas contamination in the Inconel material

  3. How Smog Awareness Influences Public Acceptance of Congestion Charge Policies

    OpenAIRE

    Lingyi Zhou; Yixin Dai

    2017-01-01

    Although various studies have investigated public acceptance of congestion charge policies, most of them have focused on behavioral and policy-related factors, and did not consider the moderating influence that individual concern about smog and perceived smog risk may have on public acceptance. This paper takes the congestion charge policy in China, targeted at smog and traffic control, and checks how smog awareness—including smog concerns and perceived smog risks, besides behavioral and poli...

  4. The large size straw drift chambers of the COMPASS experiment

    CERN Document Server

    Bychkov, V N; Dünnweber, W; Faessler, Martin A; Fischer, H; Franz, J; Geyer, R; Gousakov, Yu V; Grünemaier, A; Heinsius, F H; Ilgner, C; Ivanchenko, I M; Kekelidze, G D; Königsmann, K C; Livinski, V V; Lysan, V M; Marzec, J; Matveev, D A; Mishin, S V; Mialkovski, V V; Novikov, E A; Peshekhonov, V D; Platzer, K; San, M; Schmid, T; Shokin, V I; Sissakian, A N; Viriasov, K S; Wiedner, U; Zaremba, K; Zhukov, I A; Zlobin, Y L; Zvyagin, A

    2005-01-01

    Straw drift chambers are used for the Large Area Tracking (LAT) of the Common Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) at CERN. An active area of 130 m2 in total is covered by 12 440 straw tubes, which are arranged in 15 double layers. The design has been optimized with respect to spatial resolution, rate capability, low material budget and compactness of the detectors. Mechanical and electrical design considerations of the chambers are discussed as well as new production techniques. The mechanical precision of the chambers has been determined using a CCD X-ray scanning apparatus. Results about the performance during data taking in COMPASS are described.

  5. Interim Report 'Winter smog and traffic'.

    NARCIS (Netherlands)

    Bloemen, H.; Blom, T.; Bogaard, van den C.; Boluyt, N.; Bree, van L.; Brunekreef, B.; Hoek, G.; Zee, van der S.

    1994-01-01

    This report presents a halfway score of the research project "Winter smog and Traffic", one of the themes of the research programme "Air Pollution and Health". A state of the art is presented of the health effects associated with exposure to winter smog and of the toxicological effects caused by the

  6. Stereo: cylindrical drift chamber for muon decay experiments at LAMPF

    International Nuclear Information System (INIS)

    Bolton, R.D.; Carlini, R.D.; Cooper, M.D.; Frank, J.S.; Hart, V.E.; Matis, H.S.; Mischke, R.E.; Sandberg, V.D.; Sennhauser, U.

    1983-01-01

    A stereo, cylindrical drift chamber has been built for use in a search for rare decay modes of the muon at LAMPF. This chamber (part of the Crystal Box detector) has 728 cells on 8 concentric annuli at alternating angles of 10 0 to 16 0 from the chamber axis and with radii from 105 to 220 mm. The basic cell cross section is (9 x 10) mm 2 and the inter-layer spacing is 4.7 mm. Preliminary results show the single-wire efficiencies to be greater than 99%. Based on results obtained from prototype chambers, we hope to achieve 170-μm resolution (including multiple scattering) when TDC offsets and sense-wire locations found in a careful inspection of the endplates are added to the track-finding algorithm

  7. An example of radiation-education experiment using a new-type handy cloud chamber

    International Nuclear Information System (INIS)

    Kushita, Kouhei

    2005-01-01

    We have developed a new-type handy cloud chamber to overcome shortcomings in the conventional handy cloud chambers. The new-type handy cloud chamber has such advantages as: no dangerous parts or tools are used; can be assembled quickly; has a wider observation window; much less expensive, etc. We have also prepared a new text for this cloud-chamber kit to explain the basic theory of radiation and radioisotopes, which is divided into two levels for children and for adults. Using this new-type handy cloud chamber, we propose an example of an educational experiment on radiation and radioisotopes which can be carried out within one hour. (author)

  8. Two Simulated-Smog Atmospheres with Different Chemical Compositions Produce Contrasting Mutagenicity in Salmonella**

    Science.gov (United States)

    Ozone (O3), particulate matter (PM), and nitrogen dioxide (NO2) are criteria pollutants used to evaluate air quality. Using EPA’s Mobile Reaction Chamber (MRC), we generated 2 simulated-smog atmospheres (SSA-1 & SSA-2) with different concentrations of these criteria pol...

  9. Adaptation of multiwire chambers to some recent experiments in elementary particle physics

    International Nuclear Information System (INIS)

    Comby, G.

    1977-01-01

    Three realizations of gas multiplication detectors are presented in the field of multiwire chambers. Le 'NEUTRINO' experiment is intended for investigating neutrino interactions at energies as high as possible with using drift chambers. The 'LEZARD' experiment is intended for investigating lepton and hadron production at high transverse momentum in hadron-nucleon collisions up to the higher energies attainable at SPS (use of a multiwire proportional chamber), the apparatus has the performance of a spectrometer. A spark chamber equipped with memories has been developed for controlling bubble chamber experiments. Emphasis is put on the evolution towards detectors associated with 'another thing' to obtain a more specific operation: such as the plasma memory and spark chamber association, some possible association with function gaps is pointed out (delay function, homothetic function) [fr

  10. Smog monitored. A review of smog in the Netherlands, 1960-2010

    International Nuclear Information System (INIS)

    Buijsman, E.

    2012-01-01

    Over the last decades, the Dutch air quality has improved dramatically. Quite some time has passe since the last real episode of air pollution in the Netherlands. Nevertheless, the authorities and the media still report regularly about smog. Air pollution is more quickly labeled as smog nowadays. This article offers an overview of the recent past when poor air quality was simply called air pollution and when smog was much more common than today. [nl

  11. Large proportional chambers for muon detection in the CELLO experiment at PETRA

    International Nuclear Information System (INIS)

    Aleksan, R.; Bouchez, J.; Cozzika, G.; Ducros, Y.; Durand, A.; Francinet, G.; Gaidot, A.; Heitzmann, J.; Martin, H.; Maillet, J.C.

    1981-01-01

    We describe the muon detector in the CELLO experiment. This detector is composed of one layer of proportional chambers placed after a total of 5 interaction lengths of matter. These chambers have cathode read-out, thus enabling the unambiguous determination of coordinates. A total of 32 chambers has been built in order to cover 95% of the total solid angle. The read-out electronics use the FILAS intergrated chips made by EFCIS. Data concentration is done by a multiplexing system which addresses only those chambers which have some information. The precision is poor, but sufficient for muon detection: sigma = +-6 mm. (orig.)

  12. Hardware processors for pattern recognition tasks in experiments with wire chambers

    International Nuclear Information System (INIS)

    Verkerk, C.

    1975-01-01

    Hardware processors for pattern recognition tasks in experiments with multiwire proportional chambers or drift chambers are described. They vary from simple ones used for deciding in real time if particle trajectories are straight to complex ones for recognition of curved tracks. Schematics and block-diagrams of different processors are shown

  13. Sag compensation system for assembly of MDT-chambers for the ATLAS experiment

    International Nuclear Information System (INIS)

    Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Evtukhovich, P.G.; Il'yushenko, E.N.; Kotov, S.A.; Kruchonok, V.G.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.

    2005-01-01

    The description of a system of the devices created for compensation of the gravitational deflection of the drift chamber during its assembly is presented. By means of this system during stage-by-stage gluing of layers of tube drift detectors to the chamber the transversal deflection considerably decreases and by that high accuracy of mutual position of separate tubes is provided. The devices were applied at assembly of 74 MDT-chambers of the ATLAS experiment. Design values of deformation of the chambers as well as the results of measurement of transversal deflections obtained during the assembly with the use of the system of sag compensation are given. Testing of chambers on the X-ray tomograph at CERN has shown that the accuracy of the positions of separate signal wires inside the assembled chambers is within the limits of the required 20 μm

  14. Prototype exposure chamber of radon for animal experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yuji; Koizumi, Akira; Yonehara, Hidenori; Shimo, Michikuni; Inaba, Jiro [National Institute of Radiological Sciences, Chiba (Japan)

    1998-12-31

    To evaluate a dose conversion factor from the `Working Level of Month` (WLM) of radon to the absorbed dose (mGy), the quality of radon and its progeny was assessed, and exposures controlled for each deposition region were planed as follows: 1) exposure of radon gas to the entire respiratory tract, 2) exposure of `unattached` fractions to the upper respiratory tract, 3) exposure of `attached` fractions onto ultrafine particles to the deep lung, 4) exposure of `attached` fractions onto fine particles to the lower respiratory tract, 5) exposure of `attached` fractions onto coarse particles to the upper respiratory tract. In this preliminary study, a prototype exposure system of radon and its progeny for small rodents was designed. A whole body exposure chamber with a volume of about 0.5 m{sup 3} was used, which it held 20 rats. The aging and mixing chamber separated by the exposure chamber had a volume of about 1 m{sup 3}. As career aerosols of radon progeny, carnauba wax aerosols as solid particles, DOS aerosols as liquid particles and NaCl aerosols as hygroscopic particles were selected. These aerosols generated using a vaporization-condensation method and/or an electrical classification method were almost monodisperse with {sigma}{sub g} of <1.2. The monitoring data on biologically related gases showed an importance in the oxygen injection system and the carbon dioxide absorption system. (author)

  15. The Great London Smog of 1952.

    Science.gov (United States)

    Polivka, Barbara J

    2018-04-01

    : The Great London Smog of December 1952 lasted five days and killed up to 12,000 people. The smog developed primarily because of extensive burning of high-sulfur coal. The health effects were both immediate and long lasting, with a recent study revealing an increased likelihood of childhood asthma development in those exposed to the Great Smog while in utero or during their first year of life. Subsequent pollution legislation-including the U.S. Clean Air Act and its amendments-have demonstrably reduced air pollution and positively impacted health outcomes. With poor air quality events like the Great Smog continuing to occur today, nurses need to be aware of the impact such environmental disasters can have on human health.

  16. Studies of particle interactions in bubble chamber, spark chambers and counter experiments. Annual progress report

    International Nuclear Information System (INIS)

    Holloway, L.E.; O'Halloran, T.A. Jr.; Simmons, R.O.

    1983-07-01

    During the past six years we have carried out and planned experiments which predominantly studied the production and decay of particles containing charmed quarks. A series of photoproduction and neutron production experiments started with the very early observation of the production of J/psi by neutrons and by photons at Fermilab. From subsequent experiments using these neutral beams and the basic detecting system, we have reported results on the photoproduction of the Λ/sub c/ charmed baryon and the D and D* charmed mesons. More recent runs are studying the high energy photoproduction of vector mesons including the psi'. The present experiment in this sequence is using neutrons to produce a large number of D mesons. Another series of experiments at Fermilab set out to study the hadronic production of charmed mesons. The Chicago Cyclotron facility was modified with a detector sensitive to various possible production mechanisms. The experiments were a success; clean signals of D mesons were observed to be produced by pions, and also the production of chi/sub c/ with the subsequent decay via a γ-ray to psi was observed. The charmonium experiments run this year have better photon resolution for measuring the decays of chi/sub c/ to psi. We are part of a collaboration which is working on the Collider Detector Facility for Fermilab. The CDF at Fermilab is a possible source of (weak) intermediate vector bosons from the collisions of protons and anti-protons. Our responsibilities in the CDF include both the construction of the muon detector and the designing, planning, and testing of the FASTBUS electronics. The second part of our weak interaction program is the Neutrino Oscillation experiment which is now under construction at Brookhaven

  17. Silicon drift chamber studies for the RHIC STAR experiment

    International Nuclear Information System (INIS)

    Humanic, T.J.

    1992-01-01

    The two-hit resolution of a silicon drift chamber is measured using a pulsed Nd:Yag laser and a time digitizer readout. The data is analyzed by forming the covariance matrix in time samples, and transforming to a matrix in amplitude and time variation of each of the two hits. The resolution of the two-hit separation is found to be better than 25 microns with a drift field of 530 V/cm and a separation of more than 500 microns, with the resolution increasing to 50 microns as the separation nears 500 microns. Results are also presented for multiply ionizing tracks, showing a great improvement over single minimum ionizing. 8 refs

  18. Development of Aluminium Vacuum Chambers for the LHC Experiments at CERN

    CERN Document Server

    Gallilee, M; Costa-Pinto, P; Lepeule, P; Perez-Espinos, J; Marques Antunes Ferreira, L; Prever-Loiri, L; Sapountzis, A

    2014-01-01

    Beam losses may cause activation of vacuum chamber walls, in particular those of the Large Hadron Collider (LHC) experiments. For the High Luminosity (HL-LHC), the activation of such vacuum chambers will increase. It is therefore necessary to use a vacuum chamber material which interacts less with the circulating beam. While beryllium is reserved for the collision point, a good compromise between cost, availability and transparency is obtained with aluminium alloys; such materials are a preferred choice with respect to austenitic stainless steel. Manufacturing a thin-wall aluminium vacuum chamber presents several challenges as the material grade needs to be machinable, weldable, leak-tight for small thicknesses, and able to withstand heating to 250°C for extended periods of time. This paper presents some of the technical challenges during the manufacture of these vacuum chambers and the methods for overcoming production difficulties, including surface treatments and Non-Evaporable Getter (NEG) thin-film coat...

  19. Smog induces oxidative stress and microbiota disruption.

    Science.gov (United States)

    Wong, Tit-Yee

    2017-04-01

    Smog is created through the interactions between pollutants in the air, fog, and sunlight. Air pollutants, such as carbon monoxide, heavy metals, nitrogen oxides, ozone, sulfur dioxide, volatile organic vapors, and particulate matters, can induce oxidative stress in human directly or indirectly through the formation of reactive oxygen species. The outermost boundary of human skin and mucous layers are covered by a complex network of human-associated microbes. The relation between these microbial communities and their human host are mostly mutualistic. These microbes not only provide nutrients, vitamins, and protection against other pathogens, they also influence human's physical, immunological, nutritional, and mental developments. Elements in smog can induce oxidative stress to these microbes, leading to community collapse. Disruption of these mutualistic microbiota may introduce unexpected health risks, especially among the newborns and young children. Besides reducing the burning of fossil fuels as the ultimate solution of smog formation, advanced methods by using various physical, chemical, and biological means to reduce sulfur and nitrogen contains in fossil fuels could lower smog formation. Additionally, information on microbiota disruption, based on functional genomics, culturomics, and general ecological principles, should be included in the risk assessment of prolonged smog exposure to the health of human populations. Copyright © 2017. Published by Elsevier B.V.

  20. Plasma Chamber and First Wall of the Ignitor Experiment^*

    Science.gov (United States)

    Cucchiaro, A.; Coppi, B.; Bianchi, A.; Lucca, F.

    2005-10-01

    The new designs of the Plasma Chamber (PC) and of the First Wall (FW) system are based on updated scenarios for vertical plasma disruption (VDE) as well as estimates for the maximum thermal wall loadings at ignition. The PC wall thickness has been optimized to reduce the deformation during the worst disruption event without sacrificing the dimensions of the plasma column. A non linear dynamic analysis of the PC has been performed on a 360^o model of it, taking into account possible toroidal asymmetries of the halo current. Radial EM loads obtained by scaling JET measurements have been also considered. The low-cycle fatigue analysis confirms that the PC is able to meet a lifetime of few thousand cycles for the most extreme combinations of magnetic fields and plasma currents. The FW, made of Molybdenum (TZM) tiles covering the entire inner surface of the PC, has been designed to withstand thermal and EM loads, both under normal operating conditions and in case of disruption. Detailed elasto-plastic structural analyses of the most (EM) loaded tile-carriers show that these are compatible with the adopted fabrication requirements. ^*Sponsored in part by ENEA of Italy and by the U.S. DOE.

  1. Some aspects of the applications of wire chambers in high energy physics experiments at large accelerators

    International Nuclear Information System (INIS)

    Turala, M.

    1982-01-01

    An application of proportional and drift chambers in four large spectrometers at the accelerators of IHEP Serpukhov and CERN Geneva is described. An operation of wire chambers at high intensities and high multiplicities of particles is discussed. The results of investigations of their efficiencies, spatial resolution (for one and two-dimensional readout) and long term stability are presented. Problems of preselection of a given class of events are discussed. The systems for preselection of defined multiplicities or a scattering angle of particles, in which proportional chambers have been used, are described and the results of their application in the real experiments are presented. (author)

  2. Surviving With Smog and Smoke: Precision Interventions?

    Science.gov (United States)

    Cai, Hua; Wang, Chen

    2017-11-01

    Despite continuous efforts of regional governmental agencies, air pollution remains a major threat to public health worldwide. In January 2017, a severe episode of smog similar to the Great Smog of 1952 occurred in London. The longest episode of Chinese haze also developed in Beijing, during which levels of particulate matter smog and Chinese haze are associated with large numbers of premature deaths each year, at 400,000 and 1.2 million, respectively, primarily from respiratory diseases, cerebrovascular diseases, and ischemic heart diseases. In addition to air pollution, some are exposed to other harmful environmental factors, such as secondhand smoke. For countries with large populations of smokers, such as China, India, the United States, and Russia, surviving both smog and smoke is a serious problem. With novel genomic and epigenomic studies revealing air pollution- and smoking-induced mutational signatures and epigenetic editing in diseases such as lung cancer, it has become feasible to develop precision strategies for early intervention in the disease-causing pathways driven by the specific mutations or epigenetic regulations, or both. New therapies guided by gene-drug interactions and genomic biomarkers may also be developed. We discuss both perspectives regarding the urgent need to manage the toxic effects of smog and smoke for the benefit of global health and the novel concept of precision intervention to protect the exposed individuals when exposure to smog and secondhand smoke cannot be voluntarily avoided or easily modified. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  3. Performance of Resistive Plate Chambers installed during the first long shutdown of the CMS experiment

    CERN Document Server

    Shopova, M.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Sultanov, G.; Rodozov, M.; Stoykova, S.; Assran, Y.; Sayed, A.; Radi, A.; Aly, S.; Singh, G.; Abbrescia, M.; Iaselli, G.; Maggi, M.; Pugliese, G.; Verwilligen, P.; Van Doninck, W.; Colafranceschi, S.; Sharma, A.; Benussi, L.; Bianco, S.; Piccolo, D.; Primavera, F.; Cimmino, A.; Crucy, S.; Rios, A.A.O.; Tytgat, M.; Zaganidis, N.; Gul, M.; Fagot, A.; Bhatnagar, V.; Singh, J.; Kumari, R.; Mehta, A.; Ahmad, A.; Awan, I.M.; Shahzad, H.; Hoorani, H.; Asghar, M.I.; Muhammad, S.; Ahmed, W.; Shah, M.A.; Cho, S.W.; Choi, S.Y.; Hong, B.; Kang, M.H.; Lee, K.S.; Lim, J.H.; Park, S.K.; Kim, M.S.; Laktineh, I.B.; Lagarde, F.; Gouzevitch, M.; Grenier, G.; Pedraza, I.; Bernardino, S. Carpinteyro; Estrada, C. Uribe; Carrillo Moreno, S.; Valencia, F. Vazquez; Pant, L.M.; Buontempo, S.; Cavallo, N.; Fabozzi, F.; Orso, I.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Thyssen, F.; Lanza, G.; Esposito, M.; Braghieri, A.; Magnani, A.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Montagna, P.; Ban, Y.; Qian, S.J.; Choi, M.; Choi, Y.; Goh, J.; Kim, D.; Dimitrov, A.; Litov, L.; Petkov, P.; Pavlov, B.; Bagaturia, I.; Lomidze, D.; Avila, C.; Cabrera, A.; Sanabria, J.C.; Crotty, I.; Vaitkus, J.

    2016-01-01

    The CMS experiment, located at the CERN Large Hadron Collider, has a redundant muon system composed by three different detector technologies: Cathode Strip Chambers (in the forward regions), Drift Tubes (in the central region) and Resistive Plate Chambers (both its central and forward regions). All three are used for muon reconstruction and triggering. During the first long shutdown (LS1) of the LHC (2013-2014) the CMS muon system has been upgraded with 144 newly installed RPCs on the forth forward stations. The new chambers ensure and enhance the muon trigger efficiency in the high luminosity conditions of the LHC Run2. The chambers have been successfully installed and commissioned. The system has been run successfully and experimental data has been collected and analyzed. The performance results of the newly installed RPCs will be presented.

  4. GGD-richtlijn medische milieukunde : Smog en gezondheid

    NARCIS (Netherlands)

    Zuurbier M; van Buggenum S; Burghgraef F; Dijkema M; Fischer P; van den Hout K; Meijerink M; van Brederode NE; IMG; mev

    2012-01-01

    Het RIVM heeft, in opdracht van het ministerie van VWS, met de GGD'en de richtlijn 'Smog en gezondheid' ontwikkeld. Hiermee is de 'GGD-richtlijn smog' uit 2004 herzien. De richtlijn geeft GGD'en informatie over smog, smogregelgeving, effecten op de gezondheid en maatregelen om gezondheidseffecten te

  5. Measurement system for evaluation of the muon chambers for the LHCb experiment

    International Nuclear Information System (INIS)

    Nobrega, Rafael A.; Pinci, Davide

    2011-01-01

    In a detector with the complexity of the LHCb, where only for the muon system more than 1300 chambers, divided into 20 different types, will be used, resulting on more than 120 k channels to be readout, it is of crucial importance to study the many types of chambers to create a complete knowledge of the detector operation and to guarantee a high-quality performance during the experiment. To make it possible, a complete setup was built and a C++ based software was developed to carry out a set of measurements on the full-equipped chambers of the LHCb muon detector. The setup is made of front-end control electronics, high-voltage supply and acquisition circuitry while the software, running on a PC, remotely controls each element of the system and implements a number of automatized procedures to assess the main characteristics of the chambers. The main advantages of this system are its versatility and speed of measurement which are crucial to the experiment since there is the need to characterize every single chamber before final installation. Moreover, in this work it was proposed to measure the starting knee of the high-voltage operational plateau without the use of an external trigger by making use of the internal structure of the chambers. Two laboratories were prepared at CERN (European Laboratory for Particle Physics) to receive this system; one used to test chambers arrived from the CERN itself and the PNPI (Petersburg Nuclear Physics Institute) production sites, and one to test the chambers arrived from the INFN (National Institute of Nuclear Physics) production sites. In this document, the hardware and software setup will be presented together with the measurement-oriented implementations.

  6. Effects of Isoprene- and Toluene-Generated Smog on Allergic ...

    Science.gov (United States)

    Reactions of organic compounds with nitric oxide (NO) and sunlight produce complex mixtures of pollutants including secondary organic aerosol (SOA), ozone (O3), nitrogen dioxide (NO2), and reactive aldehydes. The health effects of these photochemical smog mixtures in susceptible populations including asthmatics are unclear. We assessed effects of smog generated from mixtures of NO with isoprene (IS) or toluene (TL) on allergic inflammatory responses in Balb/cJ mice. House dust mite (HDM)-sensitized or control mice were all challenged with HDM intranasally 1 d prior to whole-body inhalation exposure to IS (chamber average 509 ppb NO2, 246 ppb O3, and 160 g/m3 SOA), TL (217 ppb NO2, 129 ppb O3, and 376 g/m3 SOA), or HEPA-filtered air (4 h/d for 2 days). Mice were necropsied within 3 h after the second exposure (2 d post-HDM challenge). Assessment of breathing parameters during exposure with double-chamber plethysmography showed a trend for increased specific airway resistance and decreased minute volume during the second day of TL exposure in both non-allergic and HDM-allergic mice. HDM-allergic air-exposed mice had significant increases in numbers of bronchoalveolar lavage (BAL) alveolar macrophages (AM) and eosinophils (EO), and trends for increases in BAL indices of lung injury in comparison with non-allergic air-exposed mice. Exposure to either IS or TL attenuated the increases in AM, EO, and lung injury markers in HDM-allergic mice. The results of this

  7. Computer Modelling of Photochemical Smog Formation

    Science.gov (United States)

    Huebert, Barry J.

    1974-01-01

    Discusses a computer program that has been used in environmental chemistry courses as an example of modelling as a vehicle for teaching chemical dynamics, and as a demonstration of some of the factors which affect the production of smog. (Author/GS)

  8. Data Smog: Surviving the Info Glut.

    Science.gov (United States)

    Shenk, David

    1997-01-01

    While the ability to churn out information has exceeded our ability to process it, the goal of the information industry is to convince us that whatever we have is not enough. This article examines the drawbacks of the information age (including "data smog" and "information anxiety") and makes suggestions for limiting exposure…

  9. New indoor environment chambers and field experiment offices for research on human comfort, health and productivity

    DEFF Research Database (Denmark)

    Toftum, Jørn; Langkilde, Gunnar; Fanger, Povl Ole

    2004-01-01

    The article describes three new indoor environment chambers, a new laboratory for the study of air movement in spaces and five offices for controlled environment exposures of human subjects in field experiments at the International Centre for Indoor Environment and Energy, Technical University of...... of Denmark. Together with three older chambers, the Centre now has at its disposal 12 spaces for studying indoor environments and their impact on human comfort, health and productivity.......The article describes three new indoor environment chambers, a new laboratory for the study of air movement in spaces and five offices for controlled environment exposures of human subjects in field experiments at the International Centre for Indoor Environment and Energy, Technical University...

  10. How Smog Awareness Influences Public Acceptance of Congestion Charge Policies

    Directory of Open Access Journals (Sweden)

    Lingyi Zhou

    2017-09-01

    Full Text Available Although various studies have investigated public acceptance of congestion charge policies, most of them have focused on behavioral and policy-related factors, and did not consider the moderating influence that individual concern about smog and perceived smog risk may have on public acceptance. This paper takes the congestion charge policy in China, targeted at smog and traffic control, and checks how smog awareness—including smog concerns and perceived smog risks, besides behavioral and policy-related factors—might influence public acceptance of the policy. In this paper, we found both a direct and moderating causal relationship between smog awareness and public acceptance. Based on a sample of 574 valid questionnaires in Beijing and Shanghai in 2016, an ordered logistic regression modeling approach was used to delineate the causality between smog awareness and public acceptance. We found that both smog concerns, such as perceived smog risk, and willingness to pay (WTP were both directly and indirectly positively correlated with public acceptance. These findings imply that policymakers should increase policy fairness with environmental-oriented policy design and should express potential policy effectiveness of the smog controlling policy to citizens to increase their acceptance level.

  11. Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber

    International Nuclear Information System (INIS)

    Gallavardin, S. J.; Froyd, Karl D.; Lohmann, U.; Moehler, Ottmar; Murphy, Daniel M.; Cziczo, Dan

    2008-01-01

    Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or 'interstitial' aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation

  12. A Facility for Long-Term Mars Simulation Experiments: The Mars Environmental Simulation Chamber (MESCH)

    Science.gov (United States)

    Jensen, Lars Liengaard; Merrison, Jonathan; Hansen, Aviaja Anna; Mikkelsen, Karina Aarup; Kristoffersen, Tommy; Nørnberg, Per; Lomstein, Bente Aagaard; Finster, Kai

    2008-06-01

    We describe the design, construction, and pilot operation of a Mars simulation facility comprised of a cryogenic environmental chamber, an atmospheric gas analyzer, and a xenon/mercury discharge source for UV generation. The Mars Environmental Simulation Chamber (MESCH) consists of a double-walled cylindrical chamber. The double wall provides a cooling mantle through which liquid N2 can be circulated. A load-lock system that consists of a small pressure-exchange chamber, which can be evacuated, allows for the exchange of samples without changing the chamber environment. Fitted within the MESCH is a carousel, which holds up to 10 steel sample tubes. Rotation of the carousel is controlled by an external motor. Each sample in the carousel can be placed at any desired position. Environmental data, such as temperature, pressure, and UV exposure time, are computer logged and used in automated feedback mechanisms, enabling a wide variety of experiments that include time series. Tests of the simulation facility have successfully demonstrated its ability to produce temperature cycles and maintain low temperature (down to -140°C), low atmospheric pressure (5 10 mbar), and a gas composition like that of Mars during long-term experiments.

  13. How the IS has validated the building of the experiment chamber of the Megajoule Laser

    International Nuclear Information System (INIS)

    Anon.

    2005-01-01

    Imagine an aluminium sphere of more than 11 meters of external diameter and of a mass of about an hundred of tons. Here is the frame of the Megajoule laser experiments chamber in building in the CESTA site of the CEA, near Arcachon. The IS has been in charge of the inspection of the studies and of the fabrication. Narration. (O.M.)

  14. Jagiellonian University Drift Chamber Calibration and Track Reconstruction in the P349 Antiproton Polarization Experiment

    CERN Document Server

    Alfs, D; Moskal, P; Zieliński, M; Grzonka, D; Hauenstein, F; Kilian, K; Lersch, D; Ritman, J; Sefzick, T; Oelert, W; Diermaier, M; Widmann, E; Zmeskal, J; Wolke, M; Nadel-Turonski, P; Carmignotto, M; Horn, T; Mkrtchyan, H; Asaturyan, A; Mkrtchyan, A; Tadevosyan, V; Zhamkochyan, S; Malbrunot-Ettenauer, S; Eyrich, W; Zink, A

    2017-01-01

    The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.

  15. The present status of Brazil-Japan Collaboration on Chacaltaya Emulsion chamber experiments

    International Nuclear Information System (INIS)

    Sawayanagi, K.

    1983-01-01

    A short guide of the recent results in Brazil-Japan Collaboration on Chacaltaya Emulsion Chamber Experiments is given. An emphasis is laid on the comparison of the cosmic ray data with the p sup(-)-p Collider's results. (Author) [pt

  16. Cost effective electronics for proportional and drift chambers of 'EPECUR' experiment

    International Nuclear Information System (INIS)

    Alekseev, I.G.; Andreev, V.A.; Budkovsky, P.E.; Filimonov, E.A.; Golubev, V.V.; Kanavets, V.P.; Kats, M.M.; Koroleva, L.I.; Kovalev, A.I.; Kozlenko, N.G.; Kozlov, V.S.; Krivshich, A.G.; Kulikov, V.V.; Morozov, B.V.; Nesterov, V.M.; Novinsky, D.V.; Ryltsov, V.V.; Sadler, M.E.; Sakharov, V.A.; Soboyede, D.; Sulimov, A.D.; Sumachev, V.V.; Svirida, D.N.; Trautman, V.Yu.; Walker, E.; Watson, S.

    2007-01-01

    The 'EPECUR' experimental setup is under construction at beam line 322 of the ITEP proton synchrotron. The experiment requires several large area drift chambers to provide reasonable acceptance and fine-pitch proportional chambers for beam particle tracking. The total number of electronic channels is about 7000. A new compact and cost effective readout system for these gaseous detectors was designed, prototyped and tested in the last two years. It is based on modern technologies in analog and digital electronics and data transfer protocols. This paper presents the functional description of the whole DAQ system, including test results as an illustration of its performance

  17. LHCb: Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment

    CERN Multimedia

    Leduc, L; Veness, R

    2011-01-01

    The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

  18. A straw chambers' tracker for the high rate experiment 835 at the Fermilab accumulator

    Science.gov (United States)

    Bagnasco, S.; Dughera, G.; Giraudo, G.; Govi, G.; Marchetto, F.; Menichetti, E.; Pastrone, N.; Rumerio, P.; Trapani, P. P.

    1998-02-01

    Two layers of proportional drift tubes (aluminum mylar straws) are staggered in two cylindrical light chambers to measure charged particles' azimuthal angle. To stand the high rates (˜10 kHz/ cm2) and minimize the pile-up of the high luminosity experiment 835 at FNAL, a fast ASIC Amplifier-Shaper-Discriminator (ASD-8B) was chosen. The front-end electronics, designed exclusively with SMD components, was mounted on the downstream end plug of each chamber to avoid oscillations and noise. Design, construction and operational performances of these detectors are presented.

  19. Photochemical smog incident on June 30, 1973

    Energy Technology Data Exchange (ETDEWEB)

    Hata, S

    1973-01-01

    The first photochemical smog incident in Shizuoka prefecture (June 30, 1973) started in Hamamatsu and extended 100 km northeast as far as Fujinomiya city. This not only involved an extraordinarily large area, but the type of smog was different from that in Tokyo and Osaka. The victims were all pupils exercising at the time in the playgrounds. In Hamamatsu, 1050 children were involved and complained of eye irritation and pain, throat pain, coughs, and headaches between 2 and 3 pm, but there were no serious effects. The damages to agricultural produce were extensive and 70% of the total rice fields (1656 hectares), and 40 hectares of green scallions were affected. In Shizuoka, 716 children were affected about 5:30 pm, but in Fujinomiya, which is located further northeast, 16 children were affected about 4 pm. The movement of the damages, the locations, the extent of damages, and the direction of the wind, were puzzling in the light of the normal pattern of photochemical smogs, and the pollution sources could not be the coastal industrial area or automobile exhaust gases. Meteorological factors were similar to the usual photochemical smog conditions, but the locations of the cities involved and the wind direction from the sea suggested that the pollution source was the Pacific Ocean. Since the wind above 1000 m was northeast, circulation of industrial pollutants by the sea breeze is a possible explanation. The maximum concentration of oxidants was about 0.2 ppm in all areas except for Hamamatsu, where it was a little over 0.2 ppm.

  20. List of publications covering bubble chamber experiments carried out at CERN during the period 1960-1974

    International Nuclear Information System (INIS)

    Steel, E.W.D.

    1976-01-01

    Some 950 references are given, grouped by experiment number and bubble chamber under the main headings of incoming beam particle and momentum. The particles and momenta are: protons (4-24 GeV/c), antiprotons (0-12 GeV/c), positive kaons (0-16 GeV/c), negative kaons (0-16 GeV/c), positive pions (2.75-16 GeV/c), negative pions (2.75-18 GeV/c), deuterons (3 GeV/c), long-lived neutral kaons (0.5-2 GeV/c), and neutrinos and antineutrinos. The bubble chambers are: 30 cm CERN Chamber, 100 cm Ecole Polytechnique Heavy Liquid Chamber, 80 cm Saclay Hydrogen Bubble Chamber, 120 cm CERN Heavy Liquid Chamber, 150 cm British National Bubble Chamber, 200 cm CERN Chamber, Gargamelle heavy-liquid bubble chamber. A table of all bubble-chamber experiments proposed during 1960-1974 is included, as well as lists of experiments, for each beam particle, for which results have been published. The references give title, first author, collaborating institutions (in abbreviated form), and reference to the scientific periodical; conference papers and theses are not included. (Author)

  1. Pre-launch simulation experiment of microwave-ionosphere nonlinear interaction rocket experiment in the space plasma chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N. (Kobe University, Kobe, Japan); Tsutsui, M. (Kyoto University, Uji, Japan); Matsumoto, H. (Kyoto University, Kyoto, Japan)

    1980-09-01

    A pre-flight test experiment of a microwave-ionosphere nonlinear interaction rocket experiment (MINIX) has been carried out in a space plasma simulation chamber. Though the first rocket experiment ended up in failure because of a high voltage trouble, interesting results are observed in the pre-flight experiment. A significant microwave heating of plasma up to 300% temperature increase is observed. Strong excitations of plasma waves by the transmitted microwaves in the VLF and HF range are observed as well. These microwave effects may have to be taken into account in solar power satellite projects in the future.

  2. A New Segment Building Algorithm for the Cathode Strip Chambers in the CMS Experiment

    Directory of Open Access Journals (Sweden)

    Golutvin I.

    2016-01-01

    Full Text Available A new segment building algorithm for the Cathode Strip Chambers in the CMS experiment is presented. A detailed description of the new algorithm is given along with a comparison with the algorithm used in the CMS software. The new segment builder was tested with different Monte-Carlo data samples. The new algorithm is meant to be robust and effective for hard muons and the higher luminosity that is expected in the future at the LHC.

  3. The effects of atmospheric processes on tehran smog forming.

    Science.gov (United States)

    Mohammadi, H; Cohen, D; Babazadeh, M; Rokni, L

    2012-01-01

    Air pollution is one of the most important problems in urban areas that always threaten citizen's health. Photochemical smog is one of the main factors of air pollution in large cities like Tehran. Usually smog is not only a part of nature, but is being analyzed as an independent matter, which highly affects on the nature. It has been used as relationship between atmospheric elements such as temperature, pressure, relative humidity, wind speed with inversion in the time of smog forming and weather map in 500 Hpa level during 9 years descriptive static by using correlation coefficient in this analyze. Results show that there is a meaningful correlation between atmospheric elements and smog forming. This relation is seen between monthly average of these elements and monthly average of smog forming. However, when temperature decreases, corresponding pressure will increase and result of this will be smog forming. Usually smog increases in cold months of year due to enter cold high pressure air masses in Iran during December and January that is simultaneous with decreasing temperature and air pressure increases and inversion height distance decreases from the earth surface which cause to integrate air pollution under its surface, will cause to form smog in Tehran. It shows a meaningful and strong relation, based on resultant relations by correlation coefficient from inversion height and smog forming, so that obtained figure is more than 60% .

  4. Early-Life Exposure to the Great Smog of 1952 and the Development of Asthma.

    Science.gov (United States)

    Bharadwaj, Prashant; Zivin, Joshua Graff; Mullins, Jamie T; Neidell, Matthew

    2016-12-15

    Little is known about the long-term effects of air pollution exposure and the root causes of asthma. We use exposure to intense air pollution from the 1952 Great Smog of London as a natural experiment to examine both issues. To determine whether exposure to extreme air pollution in utero or soon after birth affects asthma development later in life. This was a natural experiment using the unanticipated pollution event by comparing the prevalence of asthma between those exposed to the Great Smog in utero or the first year of life with those conceived well before or after the incident and those residing outside the affected area at the time of the smog. Prevalence of asthma during childhood (ages 0-15) and adulthood (ages >15) is analyzed for 2,916 respondents to the Life History portion of the English Longitudinal Study on Aging born from 1945 to 1955. Exposure to the Great Smog in the first year of life increases the likelihood of childhood asthma by 19.87 percentage points (95% confidence interval [CI], 3.37-36.38). We also find suggestive evidence that early-life exposure led to a 9.53 percentage point increase (95% CI, -4.85 to 23.91) in the likelihood of adult asthma and exposure in utero led to a 7.91 percentage point increase (95% CI, -2.39 to 18.20) in the likelihood of childhood asthma. These results are the first to link early-life pollution exposure to later development of asthma using a natural experiment, suggesting the legacy of the Great Smog is ongoing.

  5. Study of microstrip gas chambers for CMS experiment and measurement of the W boson mass in the DELPHI experiment

    International Nuclear Information System (INIS)

    Ripp-Baudot, I.

    2004-06-01

    In this document the author describes 3 fields of his research activities: first, the development and validation tests of micro-strip gas chambers for the CMS experiment; secondly, the measurements of the W boson mass and width by analysing the events: e + e - → W + W - → qq-bar qq-bar whose data have been collected in the DELPHI experiment (at the LEP-2 accelerator); and thirdly, the tagging of b-jets that is an essential tool for the study of the top quark. The last chapter is dedicated to what is expected from LHC experiments concerning the properties of the quark top: mass, spin, production and decay channels

  6. Hermeticity control system for the BMS/BMF-MDT chambers of the muon spectrometer of ATLAS experiment

    International Nuclear Information System (INIS)

    Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Dedovich, D.V.; Demichev, M.A.; Zhemchugov, A.S.; Il'yushenko, E.N.; Korolevich, Ya.V.; Kruchonok, V.G.; Lomidze, D.D.; Nikolaev, K.V.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Shcherbakov, A.A.

    2005-01-01

    Description of hermeticity certification of the JINR made muon chambers for the ATLAS experiment is presented. A high precision stand was installed in the production area of the DLNP, JINR. The description of the stand and results of the measurements and the description and results of the second testing of the drift chambers carried out after transportation to CERN are presented

  7. Study of a proportional chamber for the detection of muons in the CELLO experiment

    International Nuclear Information System (INIS)

    Durand, Alain.

    1978-01-01

    The physics of e + e - interactions that the CELLO experiment is proposing to do requires good μ detection. For this, the prototype of a wire type proportional chamber with integrated logical system read-out is under study. The various phenomena that govern the working of a wire type proportional chamber are recalled first of all. Section II deals with the various working and read-out modes. Section III is devoted to the description of the method chosen and its advantages. In Sections IV and V, the two more specifically studied read-out methods are presented and it is shown that the read-out method by delay line proves to be much more delicate to use than the integrated electronic method finally selected [fr

  8. Design and Qualification of Transparent Beam Vacuum Chamber Supports for the LHCb Experiment

    CERN Document Server

    Bosch, JL; Garion, C

    2014-01-01

    Three beryllium beam vacuum chambers pass through the aperture of the large dipole magnet and particle acceptance region of the LHCb experiment, coaxial to the LHC beam. At the interior of the magnet, a system of rods and cables supports the chambers, holding them rigidly in place, in opposition to the vacuum forces caused by their conical geometry. In the scope of the current upgrade programme, the steel and aluminium structural components are replaced by a newly designed system, making use of beryllium, in addition to a number of organic materials, and are optimised for overall transparency to incident particles. Presented in this paper are the design criteria, along with the unique design developments carried out at CERN, and furthermore, a description of the technologies procured from industrial partners, specifically in obtaining the best solution for the cable components.

  9. The 10 bar hydrogen time projection chamber of the MuCap experiment

    Energy Technology Data Exchange (ETDEWEB)

    Egger, Johny [Paul Scherrer Institute, Olga/019, CH - 5232 Villigen PSI (Switzerland); Hildebrandt, Malte, E-mail: malte.hildebrandt@psi.c [Paul Scherrer Institute, Olga/019, CH - 5232 Villigen PSI (Switzerland); Petitjean, Claude [Paul Scherrer Institute, Olga/019, CH - 5232 Villigen PSI (Switzerland)

    2011-02-01

    The experimental goal of the MuCap experiment at the Paul Scherrer Institute (PSI) is a high-precision measurement of the singlet capture rate of the nuclear muon capture on the free proton in the reaction {mu}{sup -}+p{yields}n+{nu}{sub {mu}.} The measuring principle is a lifetime measurement whereas the experimental approach is based on a specially developed Time Projection Chamber (TPC) operating with ultra-pure and deuterium-depleted hydrogen gas at a pressure of 10 bar. The TPC acts as an active muon stop detector and the 10 bar hydrogen operates as target and detector. Design, construction and operation of the Time Projection Chamber are presented.

  10. Smog exposure and host resistance to respiratory pathogens

    Science.gov (United States)

    The US EPA is evaluating the health effects of photochemical smog on respiratory, cardiovascular and metabolic health (https://www.epa.gov/air-research/secondary-organic-aerosol-soas-research). Smog exposure has been associated with an increased risk of allergy and decreased res...

  11. Trends in photochemical smog in the Cape Peninsula and the ...

    African Journals Online (AJOL)

    There has been growing public concern over reports of increasing air pollution in the Cape Peninsula. Attention has been focused on the 'brown haze' and on photochemical smog. Because of deficiencies in the monitoring equipment, information on trends in photochemical smog levels over the past decade is limited.

  12. Foreign Experience of Activity of Chambers of Commerce and Industry and Prospects of its Introduction in Ukraine

    Directory of Open Access Journals (Sweden)

    Alexandrova Bohdana V.

    2013-12-01

    Full Text Available The article conducts analysis of foreign experience of activity of chambers of commerce and industry under conditions of market economy. It studies specific features of its formation and establishment in the countries of European Union and Commonwealth of Independent States. In particular, it analyses activity of chambers of commerce and industry of Germany, Denmark, Great Britain, Russia, Moldova and Belarus. It considers continental, anglo-saxon, state and mixed models of activity of a chamber of commerce and industry. It identifies specific features of functioning of the Chamber of Commerce and Industry of Ukraine. Having analysed the progressive experience, it offers measures for improvement of the procedure of interaction of business with the Chamber of Commerce and Industry of Ukraine at the national, regional and branch levels.

  13. Threshold bubble chamber for measurement of knock-on DT neutron tails from magnetic and inertial confinement experiments

    International Nuclear Information System (INIS)

    Fisher, R.K.; Zaveryaev, V.S.; Trusillo, S.V.

    1997-01-01

    We propose a new open-quotes thresholdclose quotes bubble chamber detector for measurement of knock-on neutron tails. These energetic neutrons result from fusion reactions involving energetic fuel ions created by alpha knock-on collisions in tokamak and other magnetic confinement experiments, and by both alpha and neutron knock-on collisions in inertial confinement fusion (ICF) experiments. The energy spectrum of these neutrons will yield information on the alpha population and energy distribution in tokamaks, and on alpha target physics and ρR measurements in ICF experiments. The bubble chamber should only detect neutrons with energies above a selectable threshold energy controlled by the bubble chamber pressure. The bubble chamber threshold mechanism, detection efficiency, and proposed applications to the International Thermonuclear Experimental Reactor and National Ignition Facility experiments will be discussed. copyright 1997 American Institute of Physics

  14. Threshold bubble chamber for measurement of knock-on DT neutron tails from magnetic and inertial confinement experiments

    International Nuclear Information System (INIS)

    Fisher, R.K.; Zaveryaev, V.S.; Trusillo, S.V.

    1996-07-01

    We propose a new open-quotes thresholdclose quotes bubble chamber detector for measurement of knock-on neutron tails. These energetic neutrons result from fusion reactions involving energetic fuel ions created by alpha knock-on collisions in tokamak and other magnetic confinement experiments, and by both alpha and neutron knock-on collisions in inertial confinement fusion (ICF) experiments. The energy spectrum of these neutrons will yield information on the alpha population and energy distribution in tokamaks, and on alpha target physics and ρR measurements in ICF experiments. The bubble chamber should only detect neutrons with energies above a selectable threshold energy controlled by the bubble chamber pressure. The bubble chamber threshold mechanism, detection efficiency, and proposed applications to the International Thermonuclear Experimental Reactor (ITER) and National Ignition Facility (NIF) experiments will be discussed

  15. Reaction Rate Benchmark Experiments with Miniature Fission Chambers at the Slovenian TRIGA Mark II Reactor

    Science.gov (United States)

    Štancar, Žiga; Kaiba, Tanja; Snoj, Luka; Barbot, Loïc; Destouches, Christophe; Fourmentel, Damien; Villard, Jean-François AD(; )

    2018-01-01

    A series of fission rate profile measurements with miniature fission chambers, developed by the Commisariat á l'énergie atomique et auxénergies alternatives, were performed at the Jožef Stefan Institute's TRIGA research reactor. Two types of fission chambers with different fissionable coating (235U and 238U) were used to perform axial fission rate profile measurements at various radial positions and several control rod configurations. The experimental campaign was supported by an extensive set of computations, based on a validated Monte Carlo computational model of the TRIGA reactor. The computing effort included neutron transport calculations to support the planning and design of the experiments as well as calculations to aid the evaluation of experimental and computational uncertainties and major biases. The evaluation of uncertainties was performed by employing various types of sensitivity analyses such as experimental parameter perturbation and core reaction rate gradient calculations. It has been found that the experimental uncertainty of the measurements is sufficiently low, i.e. the total relative fission rate uncertainty being approximately 5 %, in order for the experiments to serve as benchmark experiments for validation of fission rate profiles. The effect of the neutron flux redistribution due to the control rod movement was studied by performing measurements and calculations of fission rates and fission chamber responses in different axial and radial positions at different control rod configurations. It was confirmed that the control rod movement affects the position of the maximum in the axial fission rate distribution, as well as the height of the local maxima. The optimal detector position, in which the redistributions would have minimum effect on its signal, was determined.

  16. Development of a Time Projection Chamber using CF4 gas for relativistic heavy ion experiments

    International Nuclear Information System (INIS)

    Isobe, T.; Hamagaki, H.; Ozawa, K.; Inuzuka, M.; Sakaguchi, T.; Matsumoto, T.; Kametani, S.; Kajihara, F.; Gunji, T.; Kurihara, N.; Oda, S.X.; Yamaguchi, Y.L.

    2006-01-01

    A prototype Time Projection Chamber (TPC) using pure CF 4 gas was developed for possible use in heavy ion experiments. Basic characteristics such as gain, drift velocity, longitudinal diffusion and attenuation length of produced electrons were measured with the TPC. At an electric field of 900V/cm, the drift velocity and longitudinal diffusion for 1cm drift were obtained as 10cm/μs and 60μm, respectively. The relatively large gain fluctuation is explained to be due to the electron attachment process in CF 4 . These characteristics are encouraging for the measurement of the charged particle trajectories under high multiplicity conditions at RHIC

  17. Reproduction and evaluation of a rat model of inhalation lung injury caused by black gunpowder smog

    Directory of Open Access Journals (Sweden)

    Yi-fan LIU

    2013-09-01

    Full Text Available Objective To reproduce and evaluate a rat model of inhalation lung injury caused by black gunpowder smog. Methods The smog composition was analyzed and a rat model of inhalation lung injury was reproduced. Forty two healthy male Wistar rats were randomly divided into normal control (NC group and 1h, 2h, 6h, 24h, 48h and 96h after inhalation group (n=6. The arterial blood gas, wet to dry weight ratio (W/D of lung, leukocyte count, and protein concentration in broncho-alveolar lavage fluid (BALF were determined. Macroscopic and microscopic changes in lung tissue were observed. Results The composition of black gunpowder smog was composed mainly of CO2 and CO, and their concentrations remained stable within 12 minutes. Smog inhalation caused a significant hypoxemia, the concentration of blood COHb reached a peak value 1h, and the W/D of lung reached peak value 2h after inhalation (P<0.05. The amount of leukocytes and content of protein in BALF increased significantly within 24h after inhalation (P<0.05. Histopathological observation showed diffuse hemorrhage, edema and inflammatory cell infiltration in lung tissue as manifestations of acute lung injury, and the injury did not recover at 96h after inhalation. Conclusion The rat model of inhalation lung injury can be reproduced using black gunpowder smog, and it has the advantages of its readiness for reproduction, reliability and stability, and it could be used for the experiment of inhalation injury in a battlefield environment.

  18. Continuous measurements of H2 and CO deposition onto soil: a laboratory soil chamber experiment

    Science.gov (United States)

    Ghosh, P.; Eiler, J.; Smith, N. V.; Thrift-Viveros, D. L.

    2004-12-01

    Hydrogen uptake in soil is the largest single component of the global budget of atmospheric H2, and is the most important parameter for predicting changes in atmospheric concentration with future changing sources (anthropogenic and otherwise). The rate of hydrogen uptake rate by soil is highly uncertain [1]. As a component of the global budget, it is simply estimated as the difference among estimates for other recognized sources and sinks, assuming the atmosphere is presently in steady state. Previous field chamber experiments [2] show that H2 deposition velocity varies complexly with soil moisture level, and possibly with soil organic content and temperature. We present here results of controlled soil chamber experiments on 3 different soil blocks (each ~20 x ~20 x ~21 cm) with a controlled range of moisture contents. All three soils are arid to semi arid, fine grained, and have organic contents of 10-15%. A positive air pressure (slightly higher than atmospheric pressure) and constant temperature and relative humidity was maintained inside the 10.7 liter, leak-tight plexiglass chamber, and a stream of synthetic air with known H2 concentration was continuously bled into the chamber through a needle valve and mass flow meter. H2, CO and CO2 concentrations were continuously analyzed in the stream of gas exiting the chamber, using a TA 3000 automated Hg-HgO reduced gas analyzer and a LI-820 CO2 gas analyzer. Our experimental protocol involved waiting until concentrations of analyte gases in the exiting gas stream reached a steady state, and documenting how that steady state varied with various soil properties and the rate at which gases were delivered to the chamber. The rate constants for H2 and CO consumption in the chamber were measured at several soil moisture contents. The calculated deposition velocities of H2 and CO into the soil are positively correlated with steady-state concentrations, with slopes and curvatures that vary with soil type and moisture level

  19. Supernova cooling in a dark matter smog

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yue, E-mail: yuezhang@theory.caltech.edu [Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-11-01

    A light hidden gauge boson with kinetic mixing with the usual photon is a popular setup in theories of dark matter. The supernova cooling via radiating the hidden boson is known to put an important constraint on the mixing. I consider the possible role dark matter, which under reasonable assumptions naturally exists inside supernova, can play in the cooling picture. Because the interaction between the hidden gauge boson and DM is likely unsuppressed, even a small number of dark matter compared to protons inside the supernova could dramatically shorten the free streaming length of the hidden boson. A picture of a dark matter ''smog'' inside the supernova, which substantially relaxes the cooling constraint, is discussed in detail.

  20. Space chamber experiments of ohmic heating by high power microwave from the solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N.; Matsumoto, H.

    1981-12-01

    It is quantitatively predicted that a high power microwave from the Solar Power Satellite (SPS) nonlinearly interacts with the ionospheric plasma. The possible nonlinear interactions are ohmic heating, self-focusing and parametric instabilities. A rocket experiment called MINIX (Microwave-Ionosphere Nonlinear Interaction Experiment) has been attempted to examine these effects, but is note reported here. In parallel to the rocket experiment, a laboratory experiment in a space plasma simulation chamber has been carried out in order to examine ohmic heating in detail and to develop a system of the rocket experiment. Interesting results were observed and these results were utilized to revise the system of the rocket experiments. A significant microwave heating of plasma up to 150% temperature increase was observed with little electron density decrease. It was shown that the temperature increase is not due to the RF breakdown but to the ohmic heating in the simulated ionospheric plasma. These microwave effects have to be taken into account in the SPS Project in the future.

  1. A track chamber with controlled heat centres as a vertex detector for very high energy physics experiments

    International Nuclear Information System (INIS)

    Shcherbakov, Yu.A.

    1989-01-01

    A high-pressure vertex detector for high energy experiments is proposed on the basis of development of a new track detector of charged particles, which is a chamber with controlled centres. A possible design of this chamber is discussed. Laser illumination of a streamer chamber allows enough light for reading the information by means of a CCD device. Some characteristics of the set-up are considered in the paper. A possibility of using a new method for suppression of diffusion is discussed. 30 refs.; 7 figs.; 3 tabs

  2. A high-pressure hydrogen time projection chamber for the MuCap experiment

    Energy Technology Data Exchange (ETDEWEB)

    Egger, J.; Fahrni, D.; Hildebrandt, M.; Hofer, A.; Meier, L.; Petitjean, C. [Paul Scherrer Institute, Villigen PSI (Switzerland); Andreev, V.A.; Ganzha, V.A.; Kravtsov, P.A.; Krivshich, A.G.; Maev, E.M.; Maev, O.E.; Petrov, G.; Semenchuk, G.G.; Vasilyev, A.A.; Vorobyov, A.A.; Vznuzdaev, M.E. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Banks, T.I. [University of California, Department of Physics, Berkeley, California (United States); Clayton, S.M. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, Illinois (United States); Gray, F.E. [University of California, Department of Physics, Berkeley, California (United States); Regis University, Department of Physics and Computational Science, Denver, Colorado (United States); University of Washington, Department of Physics, Seattle, Washington (United States); Kammel, P.; Kiburg, B.; Winter, P. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, Illinois (United States); University of Washington, Department of Physics, Seattle, Washington (United States); Lauss, B. [Paul Scherrer Institute, Villigen PSI (Switzerland); University of California, Department of Physics, Berkeley, California (United States)

    2014-10-15

    The MuCap experiment at the Paul Scherrer Institute performed a high-precision measurement of the rate of the basic electroweak process of nuclear muon capture by the proton, μ{sup -} + p → n + ν{sub μ}. The experimental approach was based on the use of a time projection chamber (TPC) that operated in pure hydrogen gas at a pressure of 10bar and functioned as an active muon stopping target. The TPC detected the tracks of individual muon arrivals in three dimensions, while the trajectories of outgoing decay (Michel) electrons were measured by two surrounding wire chambers and a plastic scintillation hodoscope. The muon and electron detectors together enabled a precise measurement of the μp atom's lifetime, from which the nuclear muon capture rate was deduced. The TPC was also used to monitor the purity of the hydrogen gas by detecting the nuclear recoils that follow muon capture by elemental impurities. This paper describes the TPC design and performance in detail. (orig.)

  3. Semi-automated operation of Mars Climate Simulation chamber - MCSC modelled for biological experiments

    Science.gov (United States)

    Tarasashvili, M. V.; Sabashvili, Sh. A.; Tsereteli, S. L.; Aleksidze, N. D.; Dalakishvili, O.

    2017-10-01

    The Mars Climate Simulation Chamber (MCSC) (GEO PAT 12 522/01) is designed for the investigation of the possible past and present habitability of Mars, as well as for the solution of practical tasks necessary for the colonization and Terraformation of the Planet. There are specific tasks such as the experimental investigation of the biological parameters that allow many terrestrial organisms to adapt to the imitated Martian conditions: chemistry of the ground, atmosphere, temperature, radiation, etc. MCSC is set for the simulation of the conduction of various biological experiments, as well as the selection of extremophile microorganisms for the possible Settlement, Ecopoesis and/or Terraformation purposes and investigation of their physiological functions. For long-term purposes, it is possible to cultivate genetically modified organisms (e.g., plants) adapted to the Martian conditions for future Martian agriculture to sustain human Mars missions and permanent settlements. The size of the chamber allows preliminary testing of the functionality of space-station mini-models and personal protection devices such as space-suits, covering and building materials and other structures. The reliability of the experimental biotechnological materials can also be tested over a period of years. Complex and thorough research has been performed to acquire the most appropriate technical tools for the accurate engineering of the MCSC and precious programmed simulation of Martian environmental conditions. This paper describes the construction and technical details of the equipment of the MCSC, which allows its semi-automated, long-term operation.

  4. Studies of particle interactions in bubble chamber, spark chambers and counter experiments: Task P. Annual progress report

    International Nuclear Information System (INIS)

    Jones, L.M.; Holloway, L.; O'Halloran, T.A. Jr.; Simmons, R.O.

    1983-07-01

    Our current work reflects the general aim of this task, which is to calculate phenomenological theories of interest to present experiments. Recently, this has emphasized the jet calculus approach to properties of quark and gluon jets. Progress is reviewed

  5. Mobile Smog Simulator: New Capabilities to Study Urban Mixtures

    Science.gov (United States)

    A smog simulator developed by EPA scientists and engineers has unique capabilities that will provide information for assessing the health impacts of relevant multipollutant atmospheres and identify contributions of specific sources.

  6. Progress on the superconducting magnet for the time projection chamber experiment (TPC) at PEP

    International Nuclear Information System (INIS)

    Green, M.A.; Eberhard, P.H.; Burns, W.A.

    1980-01-01

    The TPC (Time Projection Chamber) experiment at PEP will have a two meter inside diameter superconducting magnet which creatests a 1.5 T uniform solenoidal field for the TPC. The superconducting magnet coil, cryostat, cooling system, and the TPC gas pressure vessel (which operatests at 11 atm) were designed to be about two thirds of a radiation length thick. As a result, a high current density coil design was chosen. The magnet is cooled by forced flow two phase helium. The TPC magnet is the largest adiabatically stable superconducting magnet built to date. The paper presents the parameters of the TPC thin solenoid and its subsystems. Tests results from the Spring 1980 cryogenic tes are presented. The topics to be dealt with in the paper are cryogenic services and the tests of magnet subsystems such as the folded current leads. Large thin superconducting magnet technology will be important to large detectors to be used on LEP

  7. A new drift chamber TDC readout for the high intensity program of the NA48 experiment

    CERN Document Server

    Ramusino, A C; Cartiglia, N; Chiozzi, S; Clemencic, M; Damiani, C; Gianoli, A; Milano, L; Malaguti, R; Petrucci, F; Scarpa, M

    2004-01-01

    A new read-out for the drift chambers (DCH) (8192 channels) of the NA48 experiment at CERN has been developed and realized by the Ferrara and Torino INFN sites and has taken data during the 2002 run. The core of the system is a set of 32 VME-9U Time-to-Digital- Converter boards (NA48-TDC). The NA48-TDCs record the time of arrival of signals from the DCH and store them in 40 MHz pipelined ring memories pending the trigger supervisor's decision. Dual memories and data extraction resources allow independent and simultaneous processing of level-1 and level-2 trigger requests. Time measurements are performed by the TDC-F1 commercial ASICs, having an intrinsic time resolution of 120 ps and multi-hit capabilities. The NA48-TDC board features a maximum sustained rate of 500 kHz per channel.

  8. A new drift chamber TDC readout for the high intensity program of the NA48 experiment

    International Nuclear Information System (INIS)

    Arcidiacono, R.; Cartiglia, N.; Chiozzi, S.; Clemencic, M.; Cotta Ramusino, A.; Damiani, C.; Gianoli, A.; Milano, L.; Malaguti, R.; Petrucci, F.; Scarpa, M.

    2004-01-01

    A new read-out for the drift chambers (DCH) (8192 channels) of the NA48 experiment at CERN has been developed and realized by the Ferrara and Torino INFN sites and has taken data during the 2002 run. The core of the system is a set of 32 VME-9U Time-to-Digital-Converter boards (NA48-TDC). The NA48-TDCs record the time of arrival of signals from the DCH and store them in 40 MHz pipelined ring memories pending the trigger supervisor's decision. Dual memories and data extraction resources allow independent and simultaneous processing of level-1 and level-2 trigger requests. Time measurements are performed by the TDC-F1 commercial ASICs, having an intrinsic time resolution of 120 ps and multi-hit capabilities. The NA48-TDC board features a maximum sustained rate of 500 kHz per channel

  9. ASD IC for the thin gap chambers in the LHC Atlas experiment

    International Nuclear Information System (INIS)

    Sasaki, Osamu; Yoshida, Mitsuhiro

    1999-01-01

    An amplifier-shaper-discriminator (ASD) chip was designed and built for Thin Gap Chambers in the forward muon trigger system of the LHC Atlas experiment. The ASD IC uses SONY Analog Master Slice bipolar technology. The IC contains 4 channels in a QFP48 package. The gain of its first stage (preamplifier) is approximately 0.8V/pC and output from the preamplifier is received by a shaper (main-amplifier) with a gain of 7. The baseline restoration circuit is incorporated in the main-amplifier. The threshold voltage for discriminator section is common to the 4 channels and their digital output level is LVDS-compatible. The IC also has analog output of the preamplifier. The equivalent noise charge at input capacitance of 150 pF is around 7,500 electrons. The power dissipation with LDVS outputs (100 Omega load) is 59mW/ch

  10. Small-Strip Thin Gap Chambers for the Muon Spectrometer Upgrade of the ATLAS Experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00221766; The ATLAS collaboration

    2016-01-01

    The ATLAS muon system upgrade to be installed during the LHC long shutdown in 2018/19, the so called New Small Wheel (NSW), is designed to cope with the increased instantaneous luminosity in LHC Run 3. The small-strip Thin Gap Chambers (sTGC) will provide the NSW with fast trigger and high precision tracking. The construction protocol has been validated by test beam experiments on a full-size prototype sTGC detector, showing the performance requirements are met. The intrinsic spatial resolution for a single layer has been found to be about 50$\\mu$m at perpendicular incident angle, and the pads transition region has been measured to be about 4mm.

  11. Kinematical analysis with the Emulsion Cloud Chamber in the OPERA experiment

    CERN Document Server

    Di Capua, F

    2010-01-01

    The OPERA experiment aims at measuring for the first time neutrino oscil- lation in appearance mode through the detection of ni-tau in an almost pure niμ beam produced at CERN SPS (CNGS), 730 km far from the detector. The ni-tau appearance signal is identified through the measurement of the decay daughter particles of the " lepton produced in CC ni-tau interactions. Since the short-lived " particle has, at the energy of the beam, an average decay length shorter than a 1 mm, a micrometric detection resolution is needed. The OPERA appara- tus is hybrid, using nuclear emulsion as high precision tracker and electronic detectors for the time stamp, event localization in the target and muon recon- struction. The Emulsion Cloud Chamber technique fulfils the requirement of a microscopic resolution together with a large target mass. The kinematical analysis allowed by this technique is described.

  12. Krypton calibration of time projection chambers of the NA61/SHINE experiment

    CERN Document Server

    Naskret, Michal

    The NA61/SHINE experiment at CERN is searching for the critical point in phase transition between quark-gluon plasma and hadronic matter. To do so we use the most precise apparatus - Time Projection Chamber. Its main task is to find trajectories of particles created in a relativistic collision. In order to improve efficiency of TPCs, we introduce calibration using radioactive krypton gas. Simulation of events in a TPC cham- ber through a decay of excited krypton atoms gives us a spectrum, which is later fitted to the model spectrum of krypton from a Monte-Carlo simulation. The data obtained in such a way serves us to determine malfunctioning electronics in TPCs. Thanks to the krypton calibration we can create a map of pad by pad gains. In this thesis I will de- scribe in detail the NA61 experimental setup, krypton calibration procedure, calibration algorithm and results for recent calibration runs

  13. Web-based monitoring tools for Resistive Plate Chambers in the CMS experiment at CERN

    International Nuclear Information System (INIS)

    Kim, M.S.; Ban, Y.; Cai, J.; Li, Q.; Liu, S.; Qian, S.; Wang, D.; Xu, Z.; Zhang, F.; Choi, Y.; Kim, D.; Goh, J.; Choi, S.; Hong, B.; Kang, J.W.; Kang, M.; Kwon, J.H.; Lee, K.S.; Lee, S.K.; Park, S.K.

    2014-01-01

    The Resistive Plate Chambers (RPC) are used in the CMS experiment at the trigger level and also in the standard offline muon reconstruction. In order to guarantee the quality of the data collected and to monitor online the detector performance, a set of tools has been developed in CMS which is heavily used in the RPC system. The Web-based monitoring (WBM) is a set of java servlets that allows users to check the performance of the hardware during data taking, providing distributions and history plots of all the parameters. The functionalities of the RPC WBM monitoring tools are presented along with studies of the detector performance as a function of growing luminosity and environmental conditions that are tracked over time

  14. ASD IC for the thin gap chambers in the LHC ATLAS experiment

    CERN Document Server

    Sasaki, O

    1998-01-01

    An amplifier-shaper-discriminator (ASD) chip was designed and built for Thin Gap Chambers in the forward muon trigger system of the LHC ATLAS experiment. The ASD IC uses SONY Analog Master Slice bipolar technology. The IC contains 4 $9 channels in a QFP48 package. The gain of its first stage (preamplifier) is approximately 0.8 V/pC and output from the preamplifier is received by a shaper (main-amplifier) with a gain of 7. The baseline restoration circuit is $9 incorporated in the main-amplifier. The threshold voltage for the discriminator section is common to the 4 channels and their digital output level is LVDS-compatible. The IC also has analog output for the preamplifier. The equivalent $9 noise charge at input capacitance of 150 pF is around 7500 electrons. The power dissipation with LDVS outputs (100 Omega load) is 59 mW/ch. (8 refs).

  15. ASD IC for the thin gap chambers in the LHC ATLAS Experiment

    CERN Document Server

    Sasaki, O

    1999-01-01

    An amplifier-shaper-discriminator (ASD) chip was designed and built for Thin Gap Chambers in the forward muon trigger system of the LHC Atlas experiment. The ASD IC uses SONY Analog Master Slice bipolar technology. The IC contains 4 channels in a QFP48 package. The gain of its first stage (preamplifier) is approximately 0.8 V/pC and output from the preamplifier is received by a shaper (main-amplifier) with a gain of 7. The baseline restoration circuit is incorporated in the main-amplifier. The threshold voltage for discriminator section is common to the 4 channels and their digital output level is LVDS- compatible. The IC also has analog output of the preamplifier. The equivalent noise charge at input capacitance of 150 pF is around 7500 electrons. The power dissipation with LDVS outputs (100 Omega load) is 59 mW/ch.

  16. A review of chamber experiments for determining specific emission rates and investigating migration pathways of flame retardants

    Science.gov (United States)

    Rauert, Cassandra; Lazarov, Borislav; Harrad, Stuart; Covaci, Adrian; Stranger, Marianne

    2014-01-01

    The widespread use of flame retardants (FRs) in indoor products has led to their ubiquitous distribution within indoor microenvironments with many studies reporting concentrations in indoor air and dust. Little information is available however on emission of these compounds to air, particularly the measurement of specific emission rates (SERs), or the migration pathways leading to dust contamination. Such knowledge gaps hamper efforts to develop understanding of human exposure. This review summarizes published data on SERs of the following FRs released from treated products: polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), tetrabromobisphenol-A (TBBPA), novel brominated flame retardants (NBFRs) and organophosphate flame retardants (PFRs), including a brief discussion of the methods used to derive these SERs. Also reviewed are published studies that utilize emission chambers for investigations/measurements of mass transfer of FRs to dust, discussing the chamber configurations and methods used for these experiments. A brief review of studies investigating correlations between concentrations detected in indoor air/dust and possible sources in the microenvironment is included along with efforts to model contamination of indoor environments. Critical analysis of the literature reveals that the major limitations with utilizing chambers to derive SERs for FRs arise due to the physicochemical properties of FRs. In particular, increased partitioning to chamber surfaces, airborne particles and dust, causes loss through “sink” effects and results in long times to reach steady state conditions inside the chamber. The limitations of chamber experiments are discussed as well as their potential for filling gaps in knowledge in this area.

  17. The central drift chamber of the SAPHIR detector - implementation into the experiment and study of its properties

    International Nuclear Information System (INIS)

    Haas, K.M.

    1992-01-01

    At the Bonn accelerator facility ELSA the large solid angle detector SAPHIR was built for the investigation of photon induced reactions. A main component of SAPHIR is the central drift chamber (CDC) matching the magneto gap of 1m 3 . The diameter of the in total 1828 hexagonal drift cells is about 18 mm. The subject of this paper is the implementation of the CDC in the experiment. After the description of the hardware follows the presentation of the software tools for filtering and monitoring the data, which have been developed and tested. An algorithm for extracting the space time relationship is presented. The properties of the chamber with an improved gas mixture (Helium/Neon/Isobutane8 21.25:63.75:15) have been investigated. A spatial resolution of about 200 μm was achieved. The efficiency of the chamber is 97% at a tagged photon of 5x10 4 per second crossing the chamber. (orig.) [de

  18. A time projection chamber for the crystal barrel experiment at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Schaab, Dimitri; Ball, Markus; Beck, Reinhard; Ketzer, Bernhard [HISKP, Bonn University (Germany); Collaboration: CBELSA/TAPS-Collaboration

    2015-07-01

    The CBELSA/TAPS experiment focuses on baryon spectroscopy by photoproduction processes off nucleons. For this purpose the experiment consists of an inner detector and an outer detector. The outer Crystal Barrel detector mainly measures photons from the decaying resonance. For charged particle identification and in order to obtain their direction, the Inner Detector consists of three layers of scintillating fibers. This inner detector will be replaced by a Time Projection Chamber (TPC). It offers improved track reconstruction capabilities, a robust pattern recognition and, if operated in a magnetic field, an excellent momentum resolution. Moreover, one obtains a particle identification of charged particles via the specific energy loss. A TPC has been developed for the FOPI experiment which also fits to the Crystal Barrel dimensions. It operates in continuous mode using Gas Electron Multipliers (GEM) as pre-amplification stage. For the TPC detector the calibration of the detector is crucial since parameters such as drift velocity or field inhomogenities have a direct impact on the detector performance. For the CBELSA TPC a calibration system is planned, which is based on the T2K calibration system. Here, the photoelectric effect is used to release electrons at well-known positions on the cathode, which drift towards the readout plane and show the integrated spatial distortions.

  19. IPPSO raises Hydro exports in smog negotiations

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    The Independent Power Producers of Ontario (IPPSO) requested federal and provincial committees negotiating atmospheric emission standards to review Ontario Hydro's export wheeling plans. IPPSO alleges that Ontario Hydro is preparing to apply pressure on the Canadian export approval process, and is building up a major effort that will increase emissions, contrary to the objectives embodied in a number of environment protection projects such as the Ontario Smog Plan, The Federal-Provincial NOx Management Plan, the Strategic Options Plan, or the Convention on Long-Range Transboundary Air Pollution Draft NOx Protocol Negotiations. IPPSO alleges further that while Ontario Hydro is one of Canada's largest single emitter of greenhouse gases NOx, and SO 2 , and as a public sector corporation it should be the most amenable to serving the public good, the Corporation is doing exactly the opposite: it actively prevents production of electricity from less polluting sources. It is IPPSO's contention that Ontario Hydro's desire to control the Ontario market could come at significant cost to the environment

  20. The central drift chamber for the D0 experiment: Design, construction and test

    International Nuclear Information System (INIS)

    Behnke, T.

    1989-08-01

    A cylindrical drift chamber has been designed and built at the State University of New York at Stony Brook. This chamber is to be installed in the D0 detector which is being completed at the Fermi National Accelerator. In this dissertation the design, construction and testing of this chamber are described. The characteristic features of this chamber are cells formed by solid walls and a modular structure. Much discussion is given to the performance of and results from a chamber made from three final modules which was installed in the D0 interaction region during the 1988/1989 collider run. Using this chamber proton anti-proton interactions were measured at the D0 interaction point

  1. The central drift chamber for the D0 experiment: Design, construction and test

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Ties [State Univ. of New York (SUNY), Stony Brook, NY (United States)

    1989-08-01

    A cylindrical drift chamber has been designed and built at the State University of New York at Stony Brook. This chamber is to be installed in the D0 detector which is being completed at the Fermi National Accelerator. In this dissertation the design, construction and testing of this chamber are described. The characteristic features of this chamber are cells formed by solid walls and a modular structure. Much discussion is given to the performance of and results from a chamber made from three final modules which was installed in the D0 interaction region during the 1988/1989 collider run. Using this chamber proton anti-proton interactions were measured at the D0 interaction point.

  2. Stability of reference class ionization chambers used for radiotherapy dosimetry: IAEA experience

    International Nuclear Information System (INIS)

    Czap, L.; Meghzifene, A.; Shortt, K.R.; Andreo, P.

    2002-01-01

    The IAEA calibrates ionization chambers, used in radiotherapy, for its Member States. The calibrations are either for Secondary Standards Dosimetry Laboratories (SSDLs) or hospitals from countries without a SSDL. For that purpose, the IAEA calibrates mainly reference class instruments that are in turn used to cross-calibrate field class instruments at the hospital. Typically, the IAEA calibrates about 30-40 ionization chambers per year, of which about half are new chambers purchased by the IAEA for its Member States using Technical Cooperation funds. The IAEA database includes the calibration coefficients of 189 reference class ionization chambers of the following types: NE-2561/2611, NE-2571, W-30001/W-30010. The results of the calibrations and recalibrations of the ionization chambers in terms of air kerma and absorbed dose to water are presented and discussed. The ratio of 60 Co calibration coefficients N D,w /N K , labelled C K , was determined for all chambers. The use of C K as a chamber dependent parameter and quality control indicator to check the results of the routine IAEA calibrations is discussed. In the process of its routine calibrations, the IAEA identified a specific problem related to the W- 30001 ionization chambers. The stability of these chambers was found to exceed the 0.5% tolerance limit set by the International IEC standard. Other SSDLs reported similar findings. The manufacturer stopped the production of these W-30001 chambers to investigate the reasons for this anomalous behaviour. After identifying and correcting the problem, the manufacturer produced a new type of ionization chamber. Five of these chambers were tested at the IAEA and found to be within the tolerance limit

  3. Design of Plant Gas Exchange Experiments in a Variable Pressure Growth Chamber

    Science.gov (United States)

    Corey, Kenneth A.

    1996-01-01

    Sustainable human presence in extreme environments such as lunar and martian bases will require bioregenerative components to human life support systems where plants are used for generation of oxygen, food, and water. Reduced atmospheric pressures will be used to minimize mass and engineering requirements. Few studies have assessed the metabolic and developmental responses of plants to reduced pressure and varied oxygen atmospheres. The first tests of hypobaric pressures on plant gas exchange and biomass production at the Johnson Space Center will be initiated in January 1996 in the Variable Pressure Growth Chamber (VPGC), a large, closed plant growth chamber rated for 10.2 psi. Experiments were designed and protocols detailed for two complete growouts each of lettuce and wheat to generate a general database for human life support requirements and to answer questions about plant growth processes in reduced pressure and varied oxygen environments. The central objective of crop growth studies in the VPGC is to determine the influence of reduced pressure and reduced oxygen on the rates of photosynthesis, dark respiration, evapotranspiration and biomass production of lettuce and wheat. Due to the constraint of one experimental unit, internal controls, called pressure transients, will be used to evaluate rates of CO2 uptake, O2 evolution, and H2O generation. Pressure transients will give interpretive power to the results of repeated growouts at both reduced and ambient pressures. Other experiments involve the generation of response functions to partial pressures of O2 and CO2 and to light intensity. Protocol for determining and calculating rates of gas exchange have been detailed. In order to build these databases and implement the necessary treatment combinations in short time periods, specific requirements for gas injections and removals have been defined. A set of system capability checks will include determination of leakage rates conducted prior to the actual crop

  4. Engineering photochemical smog through convection towers

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, S.; Prueitt, M.L.; Bossert, J.E.; Mroz, E.J.; Krakowski, R.A.; Miller, R.L. [Los Alamos National Lab., NM (United States); Jacobson, M.Z.; Turco, R.P. [Los Alamos National Lab., NM (United States)]|[Univ. of California, Los Angeles, CA (United States). Atmospheric Sciences Dept.

    1995-02-01

    Reverse convection towers have attracted attention as a medium for cleansing modern cities. Evaporation of an aqueous mist injected at the tower opening could generate electrical power by creating descent, and simultaneously scavenge unsightly and unhealthful particulates. The study offered here assesses the influence to tower water droplets on the photochemical component of Los Angeles type smog. The primary radical chain initiator OH is likely removed into aqueous phases well within the residence time of air in the tower, and then reacts away rapidly. Organics do not dissolve, but nighttime hydrolysis of N{sub 2}O{sub 5} depletes the nitrogen oxides. A lack of HOx would slow hydrocarbon oxidation and so also ozone production. Lowering of NOx would also alter ozone production rates, but the direction is uncertain. SO{sub 2} is available in sufficient quantities in some urban areas to react with stable oxidants, and if seawater were the source of the mist, the high pH would lead to fast sulfur oxidation kinetics. With an accommodation coefficient of 10{sup {minus}3}, however, ozone may not enter the aqueous phase efficiently. Even if ozone is destroyed or its production suppressed, photochemical recovery times are on the order of hours, so that tower processing must be centered on a narrow midday time window. The cost of building the number of structures necessary for this brief turnover could be prohibitive. The increase in humidity accompanying mist evaporation could be controlled with condensers, but might otherwise counteract visibility enhancements by recreating aqueous aerosols. Quantification of the divergent forcings convection towers must exert upon the cityscape would call for coupled three dimensional modeling of transport, microphysics, and photochemistry. 112 refs.

  5. Conditions of deep magma chamber beneath Fuji volcano estimated from high- P experiments

    Science.gov (United States)

    Asano, K.; Takahashi, E.; Hamada, M.; Ushioda, M.; Suzuki, T.

    2012-12-01

    Fuji volcano, the largest in volume and eruption rate in Japan, is located at the center of Honshu, where North America, Eurasia and Philippine Sea plates meets. Because of the significance of Fuji volcano both in tectonic settings and potential volcanic hazard (particularly after the M9 earthquake in 2011), precise knowledge on its magma feeding system is essentially important. Composition of magma erupted from Fuji volcano in the last 100ky is predominantly basalt (SiO2=50-52wt%, FeO/MgO=1.5-3.0). Total lack of silica-rich magma (basaltic andesite and andesite) which are always present in other nearby volcanoes (e.g., Hakone, Izu-Oshima, see Fig.1) is an important petrologic feature of Fuji volcano. Purpose of this study is to constrain the depth of magma chamber of Fuji volcano and explain its silica-nonenrichment trend. High pressure melting experiments were carried out using two IHPVs at the Magma Factory, Tokyo Institute of Technology (SMC-5000 and SMC-8600, Tomiya et al., 2010). Basalt scoria Tr-1 which represents the final ejecta of Hoei eruption in AD1707, was adopted as a starting material. At 4kbar, temperature conditions were 1050, 1100 and 1150C, and H2O contents were 1.3, 2.7 and 4.7 wt.%, respectively. At 7kbar, temperature conditions were 1075, 1100 and 1125C, and H2O contents were 1.0, 1.1, 3.6 and 6.3wt.%, respectively. The fO2 was controlled at NNO buffer. At 4kbar, crystallization sequence at 3 wt% H2O is magnetite, plagioclase, clinopyroxene and finally orthopyroxene. At 7 kbar, and ~3 wt% H2O, the three minerals (opx, cpx, pl) appears simultaneously near the liquidus. Compositional trend of melt at 4 kbar and 7 kbar are shown with arrows in Fig.1. Because of the dominant crystallization of silica-rich opx at 7 kbar, composition of melt stays in the range SiO2=50-52wt% as predicted by Fujii (2007). Absence of silica-rich rocks in Fuji volcano may be explained by the tectonic setting of the volcano. Because Fuji volcano locates on the plate

  6. The multigap resistive plate chamber as time-of-flight detector for the STAR experiment at RHIC

    International Nuclear Information System (INIS)

    Lamas V, J.

    2002-01-01

    The multigap resistive plate chamber (MRPC) is a suitable candidate for the time-of-flight system for the STAR experiment at RHIC at the BNL. A time resolution of 50 ps with an efficiency of 98% has been measured with MRPCs composed of 6 gas gaps of 220 μm. Results obtained during the year 2000 are reported here

  7. Reconstruction of data for an experiment using multi-gap spark chambers with six-camera optics

    International Nuclear Information System (INIS)

    Maybury, R.; Daley, H.M.

    1983-06-01

    A program has been developed to reconstruct spark positions in a pair of multi-gap optical spark chambers viewed by six cameras, which were used by a Rutherford Laboratory experiment. The procedure for correlating camera views to calculate spark positions is described. Calibration of the apparatus, and the application of time- and intensity-dependent corrections are discussed. (author)

  8. Estimated emission reductions from California's enhanced Smog Check program.

    Science.gov (United States)

    Singer, Brett C; Wenzel, Thomas P

    2003-06-01

    The U.S. Environmental Protection Agency requires that states evaluate the effectiveness of their vehicle emissions inspection and maintenance (I/M) programs. This study demonstrates an evaluation approach that estimates mass emission reductions over time and includes the effect of I/M on vehicle deterioration. It includes a quantitative assessment of benefits from pre-inspection maintenance and repairs and accounts for the selection bias effect that occurs when intermittent high emitters are tested. We report estimates of one-cycle emission benefits of California's Enhanced Smog Check program, ca. 1999. Program benefits equivalent to metric tons per day of prevented emissions were calculated with a "bottom-up" approach that combined average per vehicle reductions in mass emission rates (g/gal) with average per vehicle activity, resolved by model year. Accelerated simulation mode test data from the statewide vehicle information database (VID) and from roadside Smog Check testing were used to determine 2-yr emission profiles of vehicles passing through Smog Check and infer emission profiles that would occur without Smog Check. The number of vehicles participating in Smog Check was also determined from the VID. We estimate that in 1999 Smog Check reduced tailpipe emissions of HC, CO, and NO(x) by 97, 1690, and 81 t/d, respectively. These correspond to 26, 34, and 14% of the HC, CO, and NO(x) that would have been emitted by vehicles in the absence of Smog Check. These estimates are highly sensitive to assumptions about vehicle deterioration in the absence of Smog Check. Considering the estimated uncertainty in these assumptions yields a range for calculated benefits: 46-128 t/d of HC, 860-2200 t/d of CO, and 60-91 t/d of NO(x). Repair of vehicles that failed an initial, official Smog Check appears to be the most important mechanism of emission reductions, but pre-inspection maintenance and repair also contributed substantially. Benefits from removal of nonpassing

  9. Utilizing ARC EMCS Seedling Cassettes as Highly Versatile Miniature Growth Chambers for Model Organism Experiments

    Science.gov (United States)

    Freeman, John L.; Steele, Marianne K.; Sun, Gwo-Shing; Heathcote, David; Reinsch, S.; DeSimone, Julia C.; Myers, Zachary A.

    2014-01-01

    The aim of our ground testing was to demonstrate the capability of safely putting specific model organisms into dehydrated stasis, and to later rehydrate and successfully grow them inside flight proven ARC EMCS seedling cassettes. The ARC EMCS seedling cassettes were originally developed to support seedling growth during space flight. The seeds are attached to a solid substrate, launched dry, and then rehydrated in a small volume of media on orbit to initiate the experiment. We hypothesized that the same seedling cassettes should be capable of acting as culture chambers for a wide range of organisms with minimal or no modification. The ability to safely preserve live organisms in a dehydrated state allows for on orbit experiments to be conducted at the best time for crew operations and more importantly provides a tightly controlled physiologically relevant growth experiment with specific environmental parameters. Thus, we performed a series of ground tests that involved growing the organisms, preparing them for dehydration on gridded Polyether Sulfone (PES) membranes, dry storage at ambient temperatures for varying periods of time, followed by rehydration. Inside the culture cassettes, the PES membranes were mounted above blotters containing dehydrated growth media. These were mounted on stainless steel bases and sealed with plastic covers that have permeable membrane covered ports for gas exchange. The results showed we were able to demonstrate acceptable normal growth of C.elegans (nematodes), E.coli (bacteria), S.cerevisiae (yeast), Polytrichum (moss) spores and protonemata, C.thalictroides (fern), D.discoideum (amoeba), and H.dujardini (tardigrades). All organisms showed acceptable growth and rehydration in both petri dishes and culture cassettes initially, and after various time lengths of dehydration. At the end of on orbit ISS European Modular Cultivation System experiments the cassettes could be frozen at ultra-low temperatures, refrigerated, or chemically

  10. Psychopathological Symptoms under Smog: The Role of Emotion Regulation.

    Science.gov (United States)

    Chen, Shuquan; Kong, Jiayang; Yu, Feng; Peng, Kaiping

    2017-01-01

    Over the past decade, major cities in China have suffered from severe air pollution, which is also known as smog. Despite lay considerations that smog might pose risks for psychopathology, it remains unknown whether it is only linked to affective psychopathology or to a broader range of symptomologies. Moreover, whether individual differences in emotion regulation, a transdiagnostic risk factor for psychopathology, would influence the magnitude of pollution-induced symptoms is not well understood. Using a longitudinal design, the current study measured trait emotion regulation and psychopathological symptoms in a sample of university students at Time 1 (without smog, N = 120) and then reassessed for psychopathology at Time 2 (after acute exposure to smog for 1 week, N = 102). The results showed that participants had higher levels of positive symptom distress, obsessive-compulsive symptoms, interpersonal sensitivity, depression, and psychoticism at Time 2. Moreover, reappraisal is negatively associated with smog-induced elevations in psychopathological symptoms only when participants rely heavily on suppression. We discuss the implications of this investigation for both intervention efforts and future work on the contextual factors surrounding the deployment of emotion regulation strategies.

  11. Psychopathological Symptoms under Smog: The Role of Emotion Regulation

    Directory of Open Access Journals (Sweden)

    Shuquan Chen

    2018-01-01

    Full Text Available Over the past decade, major cities in China have suffered from severe air pollution, which is also known as smog. Despite lay considerations that smog might pose risks for psychopathology, it remains unknown whether it is only linked to affective psychopathology or to a broader range of symptomologies. Moreover, whether individual differences in emotion regulation, a transdiagnostic risk factor for psychopathology, would influence the magnitude of pollution-induced symptoms is not well understood. Using a longitudinal design, the current study measured trait emotion regulation and psychopathological symptoms in a sample of university students at Time 1 (without smog, N = 120 and then reassessed for psychopathology at Time 2 (after acute exposure to smog for 1 week, N = 102. The results showed that participants had higher levels of positive symptom distress, obsessive-compulsive symptoms, interpersonal sensitivity, depression, and psychoticism at Time 2. Moreover, reappraisal is negatively associated with smog-induced elevations in psychopathological symptoms only when participants rely heavily on suppression. We discuss the implications of this investigation for both intervention efforts and future work on the contextual factors surrounding the deployment of emotion regulation strategies.

  12. Radon emanation chamber: High sensitivity measurements for the SuperNEMO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soulé, B. [Université Bordeaux 1, Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, Chemin du Solarium, Le Haut-Vigneau, BP120, F-33175 Gradignan (France); Collaboration: SuperNEMO Collaboration; and others

    2013-08-08

    Radon is a well-known source of background in ββ0ν experiments due to the high Q{sub β} value of one of its daughter nucleus, {sup 214}Bi. The SuperNEMO collaboration requires a maximum radon contamination of 0.1 mBq/m{sup 3} inside its next-generation double beta decay detector. To reach such a low activity, a drastic screening process has been set for the selection of the detector's materials. In addition to a good radiopurity, a low emanation rate is required. To test this parameter, a Radon Emanation Setup is running at CENBG. It consists in a large emanation chamber connected to an electrostatic detector. By measuring large samples and having a low background level, this setup reaches a sensitivity of a few μ Bq. m{sup −2}. d{sup −1} and is able to qualify materials used in the construction of the SuperNEMO detector.

  13. Supervised Self-Organizing Classification of Superresolution ISAR Images: An Anechoic Chamber Experiment

    Directory of Open Access Journals (Sweden)

    Radoi Emanuel

    2006-01-01

    Full Text Available The problem of the automatic classification of superresolution ISAR images is addressed in the paper. We describe an anechoic chamber experiment involving ten-scale-reduced aircraft models. The radar images of these targets are reconstructed using MUSIC-2D (multiple signal classification method coupled with two additional processing steps: phase unwrapping and symmetry enhancement. A feature vector is then proposed including Fourier descriptors and moment invariants, which are calculated from the target shape and the scattering center distribution extracted from each reconstructed image. The classification is finally performed by a new self-organizing neural network called SART (supervised ART, which is compared to two standard classifiers, MLP (multilayer perceptron and fuzzy KNN ( nearest neighbors. While the classification accuracy is similar, SART is shown to outperform the two other classifiers in terms of training speed and classification speed, especially for large databases. It is also easier to use since it does not require any input parameter related to its structure.

  14. Performance of the Drift Chambers of the CMS Experiment in the Measurement of LHC Muons

    International Nuclear Information System (INIS)

    Dominguez, D.; Fouz, M. C.

    2011-01-01

    This work deals with the study of the performance of the drift chambers of the CMS Barrel Muon detector operating at the LHC. Using the data obtained with pp collisions during the first months os LHC operation we have studied the drift cell efficiency and position resolution, as well as the effect of the existing background noise. The results confirm the excellent performance of the muon chambers. It is expected that it will improve further as statistics increase, thus allowing a correct calibration and alignment of these chambers. (Author) 6 refs.

  15. Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds

    Directory of Open Access Journals (Sweden)

    M. Schnaiter

    2016-04-01

    Full Text Available This study reports on the origin of small-scale ice crystal complexity and its influence on the angular light scattering properties of cirrus clouds. Cloud simulation experiments were conducted at the AIDA (Aerosol Interactions and Dynamics in the Atmosphere cloud chamber of the Karlsruhe Institute of Technology (KIT. A new experimental procedure was applied to grow and sublimate ice particles at defined super- and subsaturated ice conditions and for temperatures in the −40 to −60 °C range. The experiments were performed for ice clouds generated via homogeneous and heterogeneous initial nucleation. Small-scale ice crystal complexity was deduced from measurements of spatially resolved single particle light scattering patterns by the latest version of the Small Ice Detector (SID-3. It was found that a high crystal complexity dominates the microphysics of the simulated clouds and the degree of this complexity is dependent on the available water vapor during the crystal growth. Indications were found that the small-scale crystal complexity is influenced by unfrozen H2SO4 / H2O residuals in the case of homogeneous initial ice nucleation. Angular light scattering functions of the simulated ice clouds were measured by the two currently available airborne polar nephelometers: the polar nephelometer (PN probe of Laboratoire de Métérologie et Physique (LaMP and the Particle Habit Imaging and Polar Scattering (PHIPS-HALO probe of KIT. The measured scattering functions are featureless and flat in the side and backward scattering directions. It was found that these functions have a rather low sensitivity to the small-scale crystal complexity for ice clouds that were grown under typical atmospheric conditions. These results have implications for the microphysical properties of cirrus clouds and for the radiative transfer through these clouds.

  16. Short description of BMS/BMF MDT chamber production for the muon spectrometer of the ATLAS experiment

    International Nuclear Information System (INIS)

    Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Gongadze, I.B.; Gostkin, M.I.; Gus'kov, A.V.; Dedovich, D.V.; Demichev, M.A.; Evtukhovich, P.G.; Elagin, A.L.; Zhemchugov, A.S.; Il'yushenko, E.N.; Kotov, S.A.; Kotova, T.I.; Korolevich, Ya.V.; Kruchonok, V.G.; Krumshtejn, Z.V.; Kuznetsov, N.K.; Lomidze, D.D.; Nikolaev, K.V.; Potrap, I.N.; Rudenko, T.O.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Shiyakova, M.M.; Shcherbakov, A.A.; Podkladkin, S.Yu.

    2005-01-01

    The method of assembly of the MDT chambers for the muon spectrometer of the ATLAS experiment is described. During 2000-2004 ∼ 25000 drift tubes were produced at the DLNP, JINR. The tubes were assembled into 84 muon chambers of BMS/BMF type, one of the six main types for the barrel part of the ATLAS muon spectrometer. Particle momenta must be measured in the ATLAS spectrometer with very high precision (2% at 100 GeV/c and 10% at 1000 GeV/c), which required to produce the coordinate detectors with very high (∼80 μm) precision. We describe the method of assembly of large-scale 5-10 m 2 muon chambers with the signal wire mean deviation from the nominal position less than 20 μm

  17. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. Existing Smog in Lahore, Pakistan: An Alarming Public Health Concern.

    Science.gov (United States)

    Riaz, Ramsha; Hamid, Khizar

    2018-01-25

    Lahore, the second-largest and most polluted city in Pakistan, has been plagued by a heavy blanket of smog recently. The ever-growing urbanization and industrialization have contributed to the worsening air quality of the city. Smog, being hazardous to health, is leading to a rapid sprout in multiple health-related problems, as well as raising concerns about the long-term deleterious effects on public health. The current situation is expected to worsen due to the lack of an active action plan from the government's side and a failure of concerned authorities to take note of the urgency of the situation. Hence, we aim to highlight this pressing issue in the light of previously published articles, to alert the relevant authorities regarding the detrimental consequences smog can have on public health and urge them to take immediate action to avoid further damage.

  19. A high performance Front End Electronics for drift chamber readout in MEG experiment upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Chiarello, G. [Dipartimento di Matematica e Fisica “Ennio De Giorgi” – Universitá del Salento, Via Arnesano, Lecce (Italy); Istituto Nazionale di Fisica Nucleare Sez. Lecce, Via Arnesano, Lecce (Italy); Chiri, C.; Corvaglia, A.; Grancagnolo, F. [Istituto Nazionale di Fisica Nucleare Sez. Lecce, Via Arnesano, Lecce (Italy); Panareo, M. [Dipartimento di Matematica e Fisica “Ennio De Giorgi” – Universitá del Salento, Via Arnesano, Lecce (Italy); Istituto Nazionale di Fisica Nucleare Sez. Lecce, Via Arnesano, Lecce (Italy); Pepino, A., E-mail: aurora.pepino@le.infn.it [Dipartimento di Matematica e Fisica “Ennio De Giorgi” – Universitá del Salento, Via Arnesano, Lecce (Italy); Istituto Nazionale di Fisica Nucleare Sez. Lecce, Via Arnesano, Lecce (Italy); Pinto, C.; Tassielli, G. [Dipartimento di Matematica e Fisica “Ennio De Giorgi” – Universitá del Salento, Via Arnesano, Lecce (Italy); Istituto Nazionale di Fisica Nucleare Sez. Lecce, Via Arnesano, Lecce (Italy)

    2016-07-11

    Front End (FE) Electronics plays an essential role in Drift Chambers (DC) for time resolution and, therefore, spatial resolution. The use of cluster timing techniques, by measuring the timing of all the individual ionization clusters after the first one, may enable to reach resolutions even below 100 μm in the measurement of the impact parameter. To this purpose, a Front End Electronics with a wide bandwidth and low noise is mandatory in order to acquire and amplify the drift chamber signals.

  20. A high performance Front End Electronics for drift chamber readout in MEG experiment upgrade

    International Nuclear Information System (INIS)

    Chiarello, G.; Chiri, C.; Corvaglia, A.; Grancagnolo, F.; Panareo, M.; Pepino, A.; Pinto, C.; Tassielli, G.

    2016-01-01

    Front End (FE) Electronics plays an essential role in Drift Chambers (DC) for time resolution and, therefore, spatial resolution. The use of cluster timing techniques, by measuring the timing of all the individual ionization clusters after the first one, may enable to reach resolutions even below 100 μm in the measurement of the impact parameter. To this purpose, a Front End Electronics with a wide bandwidth and low noise is mandatory in order to acquire and amplify the drift chamber signals.

  1. WE-G-BRA-06: Calibrating an Ionisation Chamber: Gaining Experience Using a Dosimetry 'flight Simulator'.

    Science.gov (United States)

    Beavis, A; Saunderson, J; Ward, J

    2012-06-01

    Recently there has been great interest in the use of simulation training, with the view to enhance safety within radiotherapy practice. We have developed a Virtual Environment for Radiotherapy Training (VERT) which facilitates this, including the simulation of a number of 'Physics practices'. One such process is the calibration of an ionisation chamber for use in Linac photon beams. The VERT system was used to provide a life sized 3D virtual environment within which we were able to simulate the calibration of a departmental chamber for 6MV and 15 MV beams following the UK 1990 Code of Practice. The characteristics of the beams are fixed parameters in the simulation, whereas default (Absorbed dose to water) correction factors of the chambers are configurable thereby dictating their response in the virtual x-ray beam. When the simulation is started, a random, realistic temperature and pressure is assigned to the bunker. Measurement and chamber positional errors are assigned to the chambers. A virtual water phantom was placed on the Linac couch and irradiated through the side using a 10 × 10 field. With a chamber at the appropriate depths and irradiated iso-centrically, the Quality Indices (QI) of the beams were obtained. The two chambers were 'inter-compared', allowing the departmental chamber calibration factor to be calculated from that of the reference chamber. For the virtual 6/15 MV beams, the QI were found to be 0.668/ 0.761 and the inter-comparison ratios 0.4408/ 0.4402 respectively. The departmental chamber calibration factors were calculated; applying these and appropriate environmental corrections allowed the output of the Linac to be confirmed. We have shown how a virtual training environment can be used to demonstrate practical processes and reinforce learning. The UK CoP was used here, however any relevant protocol could be demonstrated. Two of the authors (Beavis and Ward) are Founders of Vertual Ltd, a spin-out company created to commercialise the

  2. Preliminary results of Resistive Plate Chambers operated with eco-friendly gas mixtures for application in the CMS experiment

    International Nuclear Information System (INIS)

    Abbrescia, M.; Muhammad, S.; Saviano, G.; Auwegem, P. Van; Cauwenbergh, S.; Tytgat, M.; Benussi, L.; Bianco, S.; Passamonti, L.; Pierluigi, D.; Piccolo, D.; Primavera, F.; Russo, A.; Ferrini, M.

    2016-01-01

    The operations of Resistive Plate Chambers in LHC experiments require Fluorine based (F-based) gases for optimal performance. Recent European regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. In view of the CMS experiment upgrade, several tests are ongoing to measure the performance of the detector with these new ecological gas mixtures, in terms of efficiency, streamer probability, induced charge and time resolution. Prototype chambers with readout pads and with the standard CMS electronic setup are under test. In this paper preliminary results on performance of RPCs operated with a potential eco-friendly gas candidate 1,3,3,3-Tetrafluoropropene, commercially known as HFO-1234ze, with CO 2 and CF 3 I based gas mixtures are presented and discussed for the possible application in the CMS experiment.

  3. Preliminary results of Resistive Plate Chambers operated with eco-friendly gas mixtures for application in the CMS experiment

    CERN Document Server

    Abbrescia, Marcello; Benussi, Luigi; Bianco, Stefano; Cauwenbergh, Simon Marc D; Ferrini, Mauro; Muhammad, Saleh; Passamontic, L; Pierluigi, Daniele; Piccolo, Davide; Primavera, Federica; Russo, Alessandro; Savianoc, G; Tytgat, Michael

    2016-01-01

    The operations of Resistive Plate Chambers in LHC experiments require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. In view of the CMS experiment upgrade several tests are ongoing to measure the performance of the detector in terms of efficiency, streamer probability, induced charge and time resolution. Prototype chambers with readout pads and with the standard cms electronic setup are under test. In this talk preliminary results on performance of RPCs operated with a potential eco-friendly gas candidate 1,3,3,3-Tetrafluoropropene, commercially known as HFO-1234ze and with CO2 based gas mixtures are presented and discussed for the possible application in the CMS experiment.

  4. Preliminary results of Resistive Plate Chambers operated with eco-friendly gas mixtures for application in the CMS experiment

    CERN Document Server

    Abbrescia, M.

    2016-01-01

    The operations of Resistive Plate Chambers in LHC experiments require Fluorine based (F-based) gases for optimal performance. Recent European regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. In view of the CMS experiment upgrade, several tests are ongoing to measure the performance of the detector with these new ecological gas mixtures, in terms of efficiency, streamer probability, induced charge and time resolution. Prototype chambers with readout pads and with the standard CMS electronic setup are under test. In this paper preliminary results on performance of RPCs operated with a potential eco-friendly gas candidate 1,3,3,3-Tetrafluoropropene, commercially known as HFO-1234ze, with CO2 and CF3I based gas mixtures are presented and discussed for the possible application in the CMS experiment.

  5. Scintillation counter and wire chamber front end modules for high energy physics experiments

    International Nuclear Information System (INIS)

    Baldin, Boris; DalMonte, Lou

    2011-01-01

    This document describes two front-end modules developed for the proposed MIPP upgrade (P-960) experiment at Fermilab. The scintillation counter module was developed for the Plastic Ball detector time and charge measurements. The module has eight LEMO 00 input connectors terminated with 50 ohms and accepts negative photomultiplier signals in the range 0.25...1000 pC with the maximum input voltage of 4.0 V. Each input has a passive splitter with integration and differentiation times of ∼20 ns. The integrated portion of the signal is digitized at 26.55 MHz by Analog Devices AD9229 12-bit pipelined 4-channel ADC. The differentiated signal is discriminated for time measurement and sent to one of the four TMC304 inputs. The 4-channel TMC304 chip allows high precision time measurement of rising and falling edges with ∼100 ps resolution and has internal digital pipeline. The ADC data is also pipelined which allows deadtime-less operation with trigger decision times of ∼4 (micro)s. The wire chamber module was developed for MIPP EMCal detector charge measurements. The 32-channel digitizer accepts differential analog signals from four 8-channel integrating wire amplifiers. The connection between wire amplifier and digitizer is provided via 26-wire twist-n-flat cable. The wire amplifier integrates input wire current and has sensitivity of 275 mV/pC and the noise level of ∼0.013 pC. The digitizer uses the same 12-bit AD9229 ADC chip as the scintillator counter module. The wire amplifier has a built-in test pulser with a mask register to provide testing of the individual channels. Both modules are implemented as a 6Ux220 mm VME size board with 48-pin power connector. A custom europack (VME) 21-slot crate is developed for housing these front-end modules.

  6. Climate Chamber Experiment-Based Thermal Analysis and Design Improvement of Traditional Huizhou Masonry Walls

    Directory of Open Access Journals (Sweden)

    Ling Dong

    2018-03-01

    Full Text Available Supported by thousands of years of history, traditional Huizhou buildings have played a vital role, both functionally and culturally, as residential buildings in China. Masonry walls are one of the key building components of a Huizhou building; however, the traditional Huizhou masonry wall structure, predominantly a hollow brick structure, cannot meet the local building energy code requirements, and thus needs to be improved. Within this context, the present research measures the actual thermal performance of traditional Huizhou masonry walls for historical buildings and new-built buildings, which results in mean thermal transmittances of 1.892 W/m2·K and 2.821 W/m2·K, respectively, while the local building energy code requires a minimum thermal transmittance of 1.500 W/m2·K. In order to improve the thermal performance of traditional Huizhou masonry walls, four design scenarios for wall insulation are proposed and tested in a climate chamber: (1 hollow brick wall with inorganic interior insulation mortar, (2 solid brick wall with inorganic interior insulation mortar, (3 hollow brick wall with foamed concrete, and (4 hollow brick wall with foamed concrete plus inorganic interior insulation mortar. The experiment results indicate that, among the four proposed design scenarios, only scenario 4 can significantly improve the thermal performance of Huizhou masonry walls and meet the building energy code requirements, with a mean thermal transmittance of 1.175 W/m2·K. This research lays the foundation for improving the thermal performance of Huizhou masonry walls with new insulation and construction technology, thereby helping to improve the quality of life of Huizhou residents while respecting the cultural significance of the traditional Huizhou building.

  7. Differential cardiac effects in rats exposed to atmospheric smog generated from isoprene versus toluene

    Science.gov (United States)

    The results of this study demonstrate that atmospheric smog generated from both isoprene and toluene cause cardiac effects in rats. In addition, it appears that smog from toluene is more toxic in terms of cardiac arrhythmogenicity. Smog, which is a comple...

  8. Comparative cardiopulmonary effects of particulate matter- and ozone-enhanced smog atmospheres in mice

    Science.gov (United States)

    This study was conducted to compare the cardiac effects of particulate matter (PM)-enhanced and ozone(O3)-enhanced smog atmospheres in mice. We hypothesized that O3-enhanced smog would cause greater cardiac dysfunction than PM-enhanced smog due to the higher concentrations of irr...

  9. Use of a time-projection chamber in multifragmentation experiments at the BEVALAC

    International Nuclear Information System (INIS)

    Porile, N.T.

    1991-01-01

    An exclusive study of multifragmentation is described. The moments of the fragment charge distribution are used to extract the critical exponents associated with the phase transition to which the breakup is ascribed. The fragmentation of 1 GeV/nucleon La and Au is studied by reverse kinematics using a carbon target. Fragments with Z ≤ 6 will be identified with the EOS time projection chamber (TPC) while heavier fragments will be identified with a multiple sampling ionization chamber (MUSIC). The experimental setup using these detectors will be described

  10. Note: A versatile mass spectrometer chamber for molecular beam and temperature programmed desorption experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tonks, James P., E-mail: james.tonks@awe.co.uk [Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); AWE Plc, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Galloway, Ewan C., E-mail: ewan.galloway@awe.co.uk; King, Martin O. [AWE Plc, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Kerherve, Gwilherm [VACGEN Ltd, St. Leonards-On-Sea, East Sussex TN38 9NN (United Kingdom); Watts, John F. [Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2016-08-15

    A dual purpose mass spectrometer chamber capable of performing molecular beam scattering (MBS) and temperature programmed desorption (TPD) is detailed. Two simple features of this design allow it to perform these techniques. First, the diameter of entrance aperture to the mass spectrometer can be varied to maximize signal for TPD or to maximize angular resolution for MBS. Second, the mass spectrometer chamber can be radially translated so that it can be positioned close to the sample to maximize signal or far from the sample to maximize angular resolution. The performance of this system is described and compares well with systems designed for only one of these techniques.

  11. Smog episodes, fine particulate pollution and mortality in China.

    Science.gov (United States)

    Zhou, Maigeng; He, Guojun; Fan, Maoyong; Wang, Zhaoxi; Liu, Yang; Ma, Jing; Ma, Zongwei; Liu, Jiangmei; Liu, Yunning; Wang, Linhong; Liu, Yuanli

    2015-01-01

    Starting from early January 2013, northern China was hit by multiple prolonged and severe smog events which were characterized by extremely high-level concentrations of ambient fine particulate matter (PM2.5) with hourly peaks of PM2.5 over 800 µg/m(3). However, the consequences of this severe air pollution are largely unknown. This study investigates the acute effect of the smog episodes and PM2.5 on mortality for both urban and rural areas in northern China. We collected PM2.5, mortality, and meteorological data for 5 urban city districts and 2 rural counties in Beijing, Tianjin and Hebei Province of China from January 1, 2013 through December 31, 2013. We employed the generalized additive models to estimate the associations between smog episodes or PM2.5 and daily mortality for each district/county. Without any meteorological control, the smog episodes are positively and statistically significantly associated with mortality in 5 out of 7 districts/counties. However, the findings are sensitive to the meteorological factors. After controlling for temperature, humidity, dew point and wind, the statistical significance disappears in all urban districts. In contrast, the smog episodes are consistently and statistically significantly associated with higher total mortality and mortality from cardiovascular/respiratory diseases in the two rural counties. In Ji County, a smog episode is associated with 6.94% (95% Confidence Interval, -0.20 to 14.58) increase in overall mortality, and in Ci County it is associated with a 19.26% (95% CI, 6.66-33.34) increase in overall mortality. The smog episodes kill people primarily through its impact on cardiovascular and respiratory diseases. On average, a smog episode is associated with 11.66% (95% CI, 3.12-20.90) increase in cardiovascular and respiratory mortality in Ji County, and it is associated with a 22.23% (95% CI, 8.11-38.20) increase in cardiovascular and respiratory mortality in Ci County. A 10 μg/m(3) increase in PM2

  12. Some method of treating experimental data from X-ray chamber experiments

    International Nuclear Information System (INIS)

    Michalak, W.; Sroka, J.

    1977-01-01

    The procedure of studying the scaling law conservation using the cosmic radiation data from emulsion chambers is presented. The gamma-ray families are selected and processed in order to investigate the cascade development dependency on the primary particle energy. The most meaningful gamma family characteristics are proposed. (S.B.)

  13. Experiments with a pressure-driven Stirling refrigerator with flexible chambers

    Science.gov (United States)

    McFarlane, Patrick; Suire, Jonathan; Sen, Mihir; Semperlotti, Fabio

    2014-06-01

    We report on the design and experimental testing of a Stirling refrigerator that uses air as the working fluid, and where the conventional piston-cylinder assemblies are replaced by pressure-driven flexible chambers. The two chambers are periodically compressed by pneumatic actuators resulting in airflow through the regenerator and in a net temperature difference between the chambers. An experimental setup is used to investigate the performance of the refrigerator under different operating conditions with particular attention to actuation frequencies, driving pressure differences, and phase angles between the two inputs. The time constant of the temperature difference between the two chambers is determined, and the temperature difference is measured as a function of the system parameters. The results of several tests conducted under different operating conditions show that the refrigerating effect is very robust and allows good performance even for modulated inputs. The frequency response is radically different from that of a traditional motion-driven device. This work suggests that mechanical to thermal energy conversion devices based on this principle can be successfully powered by human motion.

  14. Experiences with large-area frisch grid chambers in low-level alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Winkler, R. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.). Inst. fuer Strahlenschutz)

    1984-06-15

    The properties of parallel-plate gridded ionization chambers with areas of 300 cm/sup 2/, developed by us for alpha spectrometry of samples with low specific alpha activity are reported. Several practical hints for optimum operating conditions are presented. The chambers can be operated routinely at atmospheric pressure for several days, without the need for purification of the gas filling (P10). The minimum detectable activity at 5 MeV is 0.01 pCi, based on 4.65 standard deviations of background and 1000 min counting time. At the GSF Research Center ionization chambers of this type are used for the analysis of natural alpha emitters, as well as of transuranium nuclides in environmental samples by: a) direct alpha spectrometry without any previous treatment of the sample, b) semi-direct spectrometry after removal of organic matter by low-temperature ashing and c) spectrometry after chemical separation. Some typical example of application are given. Furthermore the range of application of the chambers in comparison to semiconductor detectors in the field of low-level alpha spectrometry is discussed.

  15. Experiences with large-area frisch grid chambers in low-level alpha spectrometry

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1984-01-01

    The properties of parallel-plate gridded ionization chambers with areas of 300 cm 2 , developed by us for alpha spectrometry of samples with low specific alpha activity are reported. Several practical hints for optimum operating conditions are presented. The chambers can be operated routinely at atmospheric pressure for several days, without the need for purification of the gas filling (P10). The minimum detectable activity at 5 MeV is 0.01 pCi, based on 4.65 standard deviations of background and 1000 min counting time. At the GSF Research Center ionization chambers of this type are used for the analysis of natural alpha emitters, as well as of transuranium nuclides in environmental samples by: a) direct alpha spectrometry without any previous treatment of the sample, b) semi-direct spectrometry after removal of organic matter by low-temperature ashing and c) spectrometry after chemical separation. Some typical example of application are given. Furthermore the range of application of the chambers in comparison to semiconductor detectors in the field of low-level alpha spectrometry is discussed. (orig.)

  16. Simulations of photochemical smog formation in complex urban areas

    Science.gov (United States)

    Muilwijk, C.; Schrijvers, P. J. C.; Wuerz, S.; Kenjereš, S.

    2016-12-01

    In the present study we numerically investigated the dispersion of photochemical reactive pollutants in complex urban areas by applying an integrated Computational Fluid Dynamics (CFD) and Computational Reaction Dynamics (CRD) approach. To model chemical reactions involved in smog generation, the Generic Reaction Set (GRS) approach is used. The GRS model was selected since it does not require detailed modeling of a large set of reactive components. Smog formation is modeled first in the case of an intensive traffic emission, subjected to low to moderate wind conditions in an idealized two-dimensional street canyon with a building aspect ratio (height/width) of one. It is found that Reactive Organic Components (ROC) play an important role in the chemistry of smog formation. In contrast to the NOx/O3 photochemical steady state model that predicts a depletion of the (ground level) ozone, the GRS model predicts generation of ozone. Secondly, the effect of direct sunlight and shadow within the street canyon on the chemical reaction dynamics is investigated for three characteristic solar angles (morning, midday and afternoon). Large differences of up to one order of magnitude are found in the ozone production for different solar angles. As a proof of concept for real urban areas, the integrated CFD/CRD approach is applied for a real scale (1 × 1 km2) complex urban area (a district of the city of Rotterdam, The Netherlands) with high traffic emissions. The predicted pollutant concentration levels give realistic values that correspond to moderate to heavy smog. It is concluded that the integrated CFD/CRD method with the GRS model of chemical reactions is both accurate and numerically robust, and can be used for modeling of smog formation in complex urban areas.

  17. 2005 Toronto smog report card : final grade C-

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-10-01

    This annual Smog Report Card for Toronto evaluates the progress made by the City toward reducing the environmental and health impacts of smog. The final grade for the City in 2005 was a C-, a decrease over the B+ issued in 2004. The report card evaluates City Council actions based on their clean air commitments. In particular, the performance on initiatives in the following six major areas were graded: energy; transit; walking and biking; fleets and fuels; intergovernmental action; and new air quality strategies. Although Toronto had a record number of smog days due to high-temperatures and high pollution levels, it had a better record on smog and climate change than either the provincial or federal levels. Greenhouse gas emissions in Toronto are actually going down, but they are up 12 and 24 per cent at the federal and provincial levels respectively. In 2005, the City of Toronto developed a new Air Quality Management Strategy to replace the Smog Plan. Future evaluations will depend on whether the strategy is effective. The report recommends that efforts should be made to reduce greenhouse gas emissions which cause global warming, as well measures to reduce the urban heat island effect by planting trees, improving energy efficiency and using lighter-coloured materials for roads, parking lots and roofs. The report card criticized that there has been no green power purchased for the City and that the transit ridership growth strategy is behind schedule. It also noted that the City is not pedestrian or bike friendly. refs., tabs., figs.

  18. Determination and analysis of uptake of gaseous hydrogen peroxide by red spruce seedlings, determined by CSTR-type chamber experiments

    International Nuclear Information System (INIS)

    Claiborn, C.S.; Aneja, V.P.; Carbonell, R.G.

    1991-01-01

    In order to better understand the pathways for damage, the fate of gaseous hydrogen peroxide in red spruce needles was examined. The uptake of gaseous hydrogen peroxide by red spruce trees was determined from controlled exposure chamber experiments in which the chamber behaved as a Continuous Stirred Tank Reactor (CSTR). The results from these experiments were analyzed using a detailed transport model developed from fundamental principles, in order to determine the fate of hydrogen peroxide in the needles and characterize the exposure. The chamber was specially designed to accommodate highly reactive gases. All inner surfaces were Teflon-coated to minimize wall losses. Fluxes of hydrogen peroxide, carbon dioxide, and water vapor were determined. Both daytime and nighttime conditions were examined. Although other investigators have reported that the flux of other, less water-soluble pollutants to red spruce decreases at night when the stomata closes, the hydrogen peroxide flux did not exhibit this behavior. The results of these studies suggest that, at the concentrations observed in the atmosphere, hydrogen peroxide does not reach the inner, mesophyll tissues, but is lost in water condensing in the cuticular wax residing in the stomatal antechamber, above the stomata. The implications of the condensation in the stomatal antechamber and subsequent reactions occurring in this water for forest damage are discussed

  19. Methane emission estimates using chamber and tracer release experiments for a municipal waste water treatment plant

    Science.gov (United States)

    Yver Kwok, C. E.; Müller, D.; Caldow, C.; Lebègue, B.; Mønster, J. G.; Rella, C. W.; Scheutz, C.; Schmidt, M.; Ramonet, M.; Warneke, T.; Broquet, G.; Ciais, P.

    2015-07-01

    This study presents two methods for estimating methane emissions from a waste water treatment plant (WWTP) along with results from a measurement campaign at a WWTP in Valence, France. These methods, chamber measurements and tracer release, rely on Fourier transform infrared spectroscopy and cavity ring-down spectroscopy instruments. We show that the tracer release method is suitable for quantifying facility- and some process-scale emissions, while the chamber measurements provide insight into individual process emissions. Uncertainties for the two methods are described and discussed. Applying the methods to CH4 emissions of the WWTP, we confirm that the open basins are not a major source of CH4 on the WWTP (about 10 % of the total emissions), but that the pretreatment and sludge treatment are the main emitters. Overall, the waste water treatment plant is representative of an average French WWTP.

  20. Common support and integration of the BMS/BMF type MDT/RPC chambers of the muon spectrometer of the ATLAS experiment

    International Nuclear Information System (INIS)

    Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Gostkin, M.I.; Gus'kov, A.V.; Dedovich, D.V.; Demichev, M.A.; Zhemchugov, A.S.; Il'yushenko, E.N.; Kotov, S.A.; Korolevich, Ya.V.; Kruchonok, V.G.; Krumshtejn, Z.V.; Kuznetsov, N.K.; Lomidze, D.D.; Potrap, I.N.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Podkladkin, S.Yu.; Sekhniaidze, G.G.

    2005-01-01

    The common support system for muon BMS/BMF drift chambers with trigger RPC chambers for the muon spectrometer of the ATLAS experiment is described. The support systems are intended for the chambers integration into combined modules and for the subsequent installation in the experimental set-up. The technology of chambers integration is described. The sagging of the drift chambers was tested by tilting the modules at different angles. The measurements were performed by means of the RASNIK optical system. The normal operation of kinematic supports was confirmed. We also present the method of the sag regulation for the BMS/BMF chambers lying in the horizontal plane which provides the minimum difference between signal wire and detector tube body sags when the modules are later installed in their working positions

  1. Development of the Experiment Control System and Performance Study of the Muon Chambers for the LHCb Experiment

    CERN Document Server

    Antunes Nobrega, R; Penso, G; Pinci, D

    2010-01-01

    The work of this thesis practically opened three fronts of the LHCb muon system : the development of the control and monitoring system of the readout electronics; the study of noise and threshold of the detector; and the study of the performance of the muon chambers. The LHCb muon readout apparatus is made 1368 Multi-Wire Proportional Chambers (MWPC) and 24 Gas Electron Multiplier (GEM) chambers connected to approximately 7500 16-channel front-end boards, resulting in 120000 output channels. The large-scale of this system naturally led to a complex control and monitoring system made of about 600 microcontrollers which are directly connected to the front-end electronics and handled by six computers. The development of this control system was accomplished within this thesis; the microcontroller’s firmware and the high level software, operating on the six local computers, were implemented. Besides configuring and monitoring the on-chamber readout electronics, a set of calibration and debugging oriented procedu...

  2. Comparison of crop yield sensitivity to ozone between open-top chamber and free-air experiments.

    Science.gov (United States)

    Feng, Zhaozhong; Uddling, Johan; Tang, Haoye; Zhu, Jianguo; Kobayashi, Kazuhiko

    2018-02-02

    Assessments of the impacts of ozone (O 3 ) on regional and global food production are currently based on results from experiments using open-top chambers (OTCs). However, there are concerns that these impact estimates might be biased due to the environmental artifacts imposed by this enclosure system. In this study, we collated O 3 exposure and yield data for three major crop species-wheat, rice, and soybean-for which O 3 experiments have been conducted with OTCs as well as the ecologically more realistic free-air O 3 elevation (O 3 -FACE) exposure system; both within the same cultivation region and country. For all three crops, we found that the sensitivity of crop yield to the O 3 metric AOT40 (accumulated hourly O 3 exposure above a cut-off threshold concentration of 40 ppb) significantly differed between OTC and O 3 -FACE experiments. In wheat and rice, O 3 sensitivity was higher in O 3 -FACE than OTC experiments, while the opposite was the case for soybean. In all three crops, these differences could be linked to factors influencing stomatal conductance (manipulation of water inputs, passive chamber warming, and cultivar differences in gas exchange). Our study thus highlights the importance of accounting for factors that control stomatal O 3 flux when applying experimental data to assess O 3 impacts on crops at large spatial scales. © 2018 John Wiley & Sons Ltd.

  3. One of the two end-cap vacuum chambers for the CMS experiment has been completed.

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    This 7.5-metre-long cone-shaped object is the fruit of many years' development and its machining and assembly were performed with the utmost precision. Part of the team involved in the design and production of the end-cap vacuum chamber for CMS, standing behind the completed segment. Picture 02 from left to right : Thierry Tardy (TS/MME), Luigi Leggiero (TS/MME), Patrick Lepeule (AT/VAC), Gérard Faber (ETH Zürich), Stefano Bongiovani (CINEL Project Manager), Giuseppe Foffano (TS/MME) and Marc Thiebert (TS/MME).

  4. Biochar application reduce ammonia volatilization in a soil-plant system: A closed chamber experiment

    Science.gov (United States)

    Mandal, Sanchita; Donner, Erica; Smith, Euan; Lombi, Enzo

    2017-04-01

    Ammonia (NH3) volatilization is considered as one of the major mechanisms responsible for the loss of nitrogen (N) from soil-plant systems worldwide. About 10-30% of N can be lost as NH3 volatilization, which constitutes a significant economic loss. In recent years carbon-based materials such as biochar have created a great research interest because of their ability to increase soil fertility by reducing nutrient loss and pollutants bioavailability in soil. Most of the studies so far have investigated how biochar addition can reduce NH3 volatilization from soils but less information is available for soil-plant systems. In this research, wheat plants (Triticum aestivum, variety: Calingiri) were grown in a calcareous soil (pH 8, calcarosol) inside a closed chamber system to assess both ammonia volatilization and plant N uptake. In this specialized glass chamber air was passed through an inlet where the flow rate was maintained using an air pump (3.5 L min-1). The air outlet was passed through a sulphuric acid trap which was used to capture the volatilized NH3 from the chamber. Plants were watered using the inlet to maintain 50% field capacity throughout the incubation. Two different biochar samples were used in this study: a poultry manure biochar (PM-BC) and a green waste compost biochar (GW-BC) produced at 250 ˚C. Five different application rates were tested (0, 0.5, 1, 1.5, and 2%). The soil was mixed with biochar samples, water, N, P, K, Ca, Mg, and S for one week before sowing. After one week of germination, plants were transferred to the chamber for further three weeks incubation for NH3 volatilization measurement. The study identified that biochar application reduced the NH3 volatilization and increase the plant biomass. Biochar application at 0.5 and 2% decreased the NH3 volatilization by 36 and 48% respectively. The N uptake of the plants also increased from 2.9 to 28% at 0.5 and 2% application rates respectively. The dry biomass of the plant also increased

  5. Study of micro-strip gas ionisation chambers substrates for CMS experiment at LHC

    International Nuclear Information System (INIS)

    Pallares, A.

    1996-01-01

    High luminosity, expected interaction and dose rates of the future LHC collider require the development of micro-strips gas chambers. In addition to optimization of this new detector, this work is concerned with understanding of gain loss phenomena. Influence of the gas substrate is carefully analysed, as well as theoretical concepts concerning glasses and their behaviour under polarization and irradiation, and the consequence on detection operations.Electron spin resonance is used to study, in standard glass, creation of radiation induced defects which may be charged. (D.L.)

  6. Modeling smog along the Los Angeles-Palm Springs trajectory

    International Nuclear Information System (INIS)

    Hanna, S.R.

    1976-01-01

    Observations of smog concentrations and wind patterns during the summer of 1973 in Los Angeles, Pomona, Riverside, Banning, and Palm Springs, California are presented which show that high oxidant concentrations at Banning and Palm Springs are often due to advection of smog from source regions in the more densely populated western part of the Los Angeles basin. At Pomona and Riverside, advection from upwind source regions combines with the effects of local emissions to cause long durations of high oxidant concentrations with peak times in the mid afternoon. An empirical model for the diurnal oxidant variation is suggested which satisfactorily simulates observed concentrations. More complex models which include chemical kinetics systems do not perform very satisfactorily at the rural stations of Banning and Palm Springs, especially at night when observed oxidant concentrations remain high

  7. Toronto smog report card 2003 : final grade C -

    International Nuclear Information System (INIS)

    2003-10-01

    An annual Smog Report Card for Toronto has been published annually by the Toronto Environmental Alliance since 1997, evaluating the progress made by the City toward reducing the environmental and health impacts of smog. The final grade for the City in 2003 was a C -, an improvement over last year's D +. The evaluation examined the performance on 33 initiatives in six major areas: leadership, transit, electricity, fleets and fuels, bikes and pedestrians, and public education. Issues that stood out were: a $30 million increase in funding to the Toronto Transit Commission (TTC), and the release of the TTC's Ridership Growth Strategy depicting how transit ridership can be increased through improved service and lower fares. The drive-through and pesticide by-laws were passed by Council, which should result in smog reduction from unnecessary activities. Leadership was found to be lacking at City Hall in the area of clean air, in view of its decision to proceed with the expansion of Island Airport. The decision to move forward on only 20 per cent of planned green power and energy efficiency measures was a low point in 2002. The City's budget process, which effectively screened out most environmental initiatives was in part responsible for the lack of progress. The following grades were awarded: transit and trip reduction (B), energy efficiency and green power received (D), fleets and fuels (C), bikes and pedestrians (C), public education (B). Recommendations for next year included: implementation of the TTC's Ridership Growth Strategy; creation of a Smog Plan Implementation Fund of $20 million per year to invest in energy efficiency, green fleets, green power and other related measures; and stop the expansion of Island Airport

  8. ARADISH - Development of a Standardized Plant Growth Chamber for Experiments in Gravitational Biology Using Ground Based Facilities

    Science.gov (United States)

    Schüler, Oliver; Krause, Lars; Görög, Mark; Hauslage, Jens; Kesseler, Leona; Böhmer, Maik; Hemmersbach, Ruth

    2016-06-01

    Plant development strongly relies on environmental conditions. Growth of plants in Biological Life Support Systems (BLSS), which are a necessity to allow human survival during long-term space exploration missions, poses a particular problem for plant growth, as in addition to the traditional environmental factors, microgravity (or reduced gravity such as on Moon or Mars) and limited gas exchange hamper plant growth. Studying the effects of reduced gravity on plants requires real or simulated microgravity experiments under highly standardized conditions, in order to avoid the influence of other environmental factors. Analysis of a large number of biological replicates, which is necessary for the detection of subtle phenotypical differences, can so far only be achieved in Ground Based Facilities (GBF). Besides different experimental conditions, the usage of a variety of different plant growth chambers was a major factor that led to a lack of reproducibility and comparability in previous studies. We have developed a flexible and customizable plant growth chamber, called ARAbidopsis DISH (ARADISH), which allows plant growth from seed to seedling, being realized in a hydroponic system or on Agar. By developing a special holder, the ARADISH can be used for experiments with Arabidopsis thaliana or a plant with a similar habitus on common GBF hardware, including 2D clinostats and Random Positioning Machines (RPM). The ARADISH growth chamber has a controlled illumination system of red and blue light emitting diodes (LED), which allows the user to apply defined light conditions. As a proof of concept we tested a prototype in a proteomic experiment in which plants were exposed to simulated microgravity or a 90° stimulus. We optimized the design and performed viability tests after several days of growth in the hardware that underline the utility of ARADISH in microgravity research.

  9. Incidence of DCS and oxygen toxicity in chamber attendants: a 28-year experience.

    Science.gov (United States)

    Witucki, Pete; Duchnick, Jay; Neuman, Tom; Grover, Ian

    2013-01-01

    Decompression sickness (DCS) and central nervous system oxygen toxicity are inherent risks for "inside" attendants (IAs) of hyperbaric chambers. At the Hyperbaric Medicine Center at the University of California San Diego (UCSD), protocols have been developed for decompressing IAs. Protocol 1: For a total bottom time (TBT) of less than 80 minutes at 2.4 atmospheres absolute (atm abs) or shallower, the U.S. Navy (1955) no-decompression tables were utilized. Protocol 2: For a TBT between 80 and 119 minutes IAs breathed oxygen for 15 minutes prior to initiation of ascent. Protocol 3: For a TBT between 120-139 minutes IAs breathed oxygen for 30 minutes prior to ascent. These protocols have been utilized for approximately 28 years and have produced zero cases of DCS and central nervous system oxygen toxicity. These results, based upon more than 24,000 exposures, have an upper limit of risk of DCS and oxygen toxicity of 0.02806 (95% CI) using UCSD IA decompression Protocol 1, 0.00021 for Protocol 2, and 0.00549 for Protocol 3. We conclude that the utilization of this methodology may be useful at other sea-level multiplace chambers.

  10. A cylindrical drift chamber for radiative muon capture experiments at TRIUMF

    International Nuclear Information System (INIS)

    Henderson, R.S.; Dawson, R.J.; Azuelos, G.; Robertson, B.C.; Hasinoff, M.D.; Ahamad, S.; Gorringe, T.P.; Serna-Angel, A.; Blecher, M.; Wright, D.H.

    1990-01-01

    In the Standard Model, the weak interaction is purely V-A in character. However in semileptonic reactions the strong force induces additional couplings. Radiative muon capture (RMC), μ - Z → ν(Z-1)γ, is a process which is particularly sensitive to the induced pseudoscalar coupling constant, g p , which is still very poorly determined experimentally. Due to the extremely small branching ratio (∼ 6 x 10 -8 ), the elementary reaction μ - p → νnγ has never been measured. Effort to date has concentrated on nuclear RMC where the branching ratio is much larger, but the interpretation of these results is hindered by nuclear structure uncertainties. A measurement is being carried out at TRIUMF to determine the rate of RMC on hydrogen to a precision of 8% leading to a determination of g p with an error of 10%. The detection system is based on a large volume cylindrical drift chamber, in an axial magnetic field, acting as an e + e - pair spectrometer with a solid angle of ≅ 2 π. The design, construction and performance of the cylindrical drift chamber are discussed

  11. Relationship between mortality and fine particles during Asian dust, smog-Asian dust, and smog days in Korea.

    Science.gov (United States)

    Kim, Hyun-Sun; Kim, Dong-Sik; Kim, Ho; Yi, Seung-Muk

    2012-01-01

    This study examined the association between all-cause/cardiovascular mortality and PM(2.5) as related to Asian dust (AD), smog-AD, smog, and nonevent days and evaluated the differential risks according to specific events for mortality. The daily records of all-cause/cardiovascular mortality and PM(2.5) from March to May 2003-2006 in Seoul, Korea, were used as independent and dependent variables. Differences in the event effects were assessed using a time-series analysis. Both all-cause and cardiovascular mortalities were significantly associated with PM(2.5) during smog-AD and AD days only. Differences in chemical composition emerging during long-range transport to Korea may explain these observations, especially as regards secondary aerosol, metal-sulfate/or nitrate, and metallic components. These results suggest that exposure to PM(2.5) during specific events is differentially associated with human mortality and that changes in the chemical composition of PM(2.5), occurring during long-range transport, represent important factors in such differential effects on health.

  12. Development of a Novel Contamination Resistant Ion Chamber for Process Tritium Measurement and Use in the JET First Trace Tritium Experiment

    International Nuclear Information System (INIS)

    Worth, L.B.C.; Pearce, R.J.H.; Bruce, J.; Banks, J.; Scales, S.

    2005-01-01

    The accuracy of process measurements of tritium with conventional ion chambers is often affected by surface tritium contamination. The measurement of tritium in the exhaust of the JET torus is particularly difficult due to surface contamination with highly tritiated hydrocarbons. JET's first unsuccessful attempt to overcome the contamination problem was to use an ion chamber, with a heating element as the chamber wall so that it could be periodically decontaminated by baking. The newly developed ion chamber works on the principle of minimising the surface area within the boundary of the anode and cathode.This paper details the design of the ion chamber, which utilises a grid of 50-micron tungsten wire to define the ion chamber wall and the collector electrode. The effective surface area which, by contamination, is able to effect the measurement of tritium within the process gas has been reduced by a factor of ∼200 over a conventional ion chamber. It is concluded that the new process ion chamber enables sensitive accurate tritium measurements free from contamination issues. It will be a powerful new tool for future tritium experiments both to improve tritium tracking and to help in the understanding of tritium retention issues

  13. Modeling and simulation of critical parameters of the first chamber of the dimuon arm spectrometer of the Alice experiment

    International Nuclear Information System (INIS)

    Guez, D.

    2003-10-01

    The Alice experiment that is dedicated to the study of ultra-relativistic heavy ion collisions, will take place in the future large hadron collider (LHC) at CERN. The dimuon arm spectrometer of the Alice experiment is devoted to the search of a new signature of the existence of the quark gluon plasma (QGP). The first chapter is dedicated to the physics notions linked to the study of QGP, a few signatures are proposed for the detection of QGP, particularly the signature concerning the production rate of quarkonium. The second chapter deals with particle detection involved in Alice experiment, the dimuon arm spectrometer is a detector dedicated to the track reconstruction of muons issued from the decay of heavy mesons from J/Ψ and Υ families. The third and the fourth chapters present the studies made to integrate a reliable model of the dimuon arm in the global simulation code of Alice (Aliroot). The fifth chapter presents the software TB 2 that has been developed within the framework of this thesis in order to check and control the output data when the detector is tested with a real particle beam. The sixth chapter presents the results of the tests that have been performed with a 7 GeV/c pion beam. These tests have shown that the electronic noise is coherent with the specifications of Alice experiment. A factor 1,8 between the highest and the weakest values of the gain has been measured in the chamber. The detection efficiency of the chamber has been estimated to 99% in the different cases studied. (A.C.)

  14. Small-Strip Thin Gap Chambers for the Muon Spectrometer Upgrade of the ATLAS Experiment

    CERN Document Server

    Perez Codina, Estel; The ATLAS collaboration

    2015-01-01

    For the forthcoming Phase-I upgrade to the LHC (2018/19), the first station of the ATLAS muon end-cap system, Small Wheel, needs to be replaced. The New Small Wheel (NSW) will have to operate in a high background radiation region while reconstructing muon tracks with high precision and providing information for the Level-1 trigger. In particular, the precision reconstruction of tracks requires a spatial resolution of about 100 μm, and the Level-1 trigger track segments have to be reconstructed with an angular resolution of approximately 1 mrad. The NSWs consist of eight layers each of Micromegas and small-strip Thin Gap Chambers (sTGC), both providing trigger and tracking capabilities. The single sTGC planes of a quadruplet consists of an anode layer of 50μm gold plated tungsten wire sandwiched between two resistive cathode layers. Behind one of the resistive cathode layers, a PCB with precise machined strips (thus the name sTGC) spaced every 3.2mm allows to achieve a position resolution that ranges from 70...

  15. The vertex detector of the UA2 experiment (a low mass self sustaining system of cylindrical multiwire proportional chambers)

    International Nuclear Information System (INIS)

    Dialinas, M.; Forget, J.; Geoffroy, D.; Jean, P.; Vergand, M.

    1983-07-01

    The construction of the cylindrical proportional strip chambers of the UA2 vertex detector is reported. The mechanical design, the engineering and the effective realization are described in detail. Possible improvements for the construction of such chambers are also given

  16. A first experiment on the scavenging of materials by rainfall using a large artificial climate experiment chamber at ACEF in IES

    International Nuclear Information System (INIS)

    Kawabata, Hitoshi; Hasegawa, Hidenao; Akata, Naofumi; Chikuchi, Yuki; Kondo, Kunio; Inaba, Jiro

    2004-01-01

    Radionuclides in the atmosphere are removed to rough surfaces on the earth through wet or dry removal. According to our past results, the wet deposition flux of sea-salt particles is larger than the dry deposition flux in Rokkasho, Aomori. Therefore, to clarify the mechanism of wet removal of aerosol particles, a laboratory experiment using a large artificial climate experiment chamber at the Artificial Climate Experiment Facility (ACEF) in the Institute for Environmental Sciences was started. We conducted a preliminary experiment on the scavenging of aerosol particles by raindrops. The scavenging coefficient for NaCl particles was larger than that for test powder (JIS Z 8901 No. 11 Kanto loam). The scavenging coefficients for NaCl particles and test powder increased exponentially with the increase of precipitation intensity. (author)

  17. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  18. Public perception of smog: A case study in Ningbo City, China.

    Science.gov (United States)

    Yang, Shuncheng; Shi, Longyu

    2017-02-01

    Smog has become a public environmental crisis in most areas of China, and in response, research efforts have mainly focused on the chemical properties of smog and its impact on human health. However, in-depth research on the public's perception of smog has not yet been conducted. A survey of residents living around eight state-controlled atmospheric environmental monitoring sites in Ningbo City was conducted using stratified sampling. The data was statistically analyzed to investigate people's views and behavioral tendencies in smog weather, the influence of different media reports on public outlook, and public opinions on the local atmosphere and pollution management in different areas. The results showed that people's perception of smog differs greatly from actual conditions, indicating that the public opinion tends to deviate when faced with a public crisis. Mainstream media (TV, newspaper, etc.), accounting for 67% of all media sources, are the main source for dissemination of smog information. The main sources of pollution, in order of decreasing contribution, according to residents of Ningbo City are as follows: motor vehicle exhaust, industrial coal combustion, large-scale construction, biomass burning, and kitchen fumes. Since 2011, most areas of China have been affected by frequent smog. Most research on smog has been concentrated on its causes, alert systems, and prevention measures, whereas in-depth research on the public perception of smog has not yet been conducted. When a risky environmental event such as smog occurs, consequences may be more serious than the event itself will cause if people take irrational measures because of lacking relevant knowledge. Therefore, investigating people's attitude and response to smog is both theoretically and practically significant.

  19. Cloud Experiment. View inside the chamber with Jasper Kirkby, Head leader of the project.

    CERN Multimedia

    Maximilien Brice

    2009-01-01

    CLOUD, the cutting-edge physics experiment that will shed light on climate-related matters, has finished its assembly phase and is starting taking data using a beam of protons from the Proton Synchrotron.

  20. Ionization chamber

    International Nuclear Information System (INIS)

    Jilbert, P.H.

    1975-01-01

    The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

  1. A prototype experiment to study charmed particle production and decay using a Holographic High Resolution Hydrogen Chamber (HOLEBC) and the European Hybrid Spectrometer

    CERN Multimedia

    2002-01-01

    The high resolution hydrogen bubble chamber LEBC has already been used in experiments at the SPS to detect particles with lifetime $\\geq 5 \\times 10^{-13}$s (NA13 & NA16). \\\\\\\\For this experiment, a new version of LEBC called HOLEBC, has been constructed. This chamber and the NA26 version of the spectrometer have been used with classical optics in the NA27 experiment. A significant improvement in resolution was achieved ($\\simeq$ 20 microns compared with $\\simeq$ 40 $\\mu$m in LEBC) and hence a good sensitivity to all (known) charmed particle decays. The development of holographic recording techniques with HOLEBC is in progress. \\\\\\\\The prototype NA26 experiment is designed to evaluate the feasibility of the high sensitivity, high resolution holographic hydrogen bubble chamber technique and evaluate various possible charm selective triggers using the information from the spectrometer.

  2. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  3. Complete fabrication of target experimental chamber and implement initial target diagnostics to be used for the first target experiments in NDCX-1

    International Nuclear Information System (INIS)

    Bieniosek, F.M.; Bieniosek, F.M.; Dickinson, M.R.; Henestroza, E.; Katayanagi, T.; Jung, J.Y.; Lee, C.W.; Leitner, M.; Ni, P.; Roy, P.; Seidl, P.; Waldron, W.; Welch, D.

    2008-01-01

    The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) has completed the fabrication of a new experimental target chamber facility for future Warm Dense Matter (WDM) experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. This achievement provides to the HIFS-VNL unique and state-of-the-art experimental capabilities in preparation for the planned target heating experiments using intense heavy ion beams

  4. Correction of effects due to reactions on complex nuclei in a sample of hydrogen-like antiproton annihilations from a heavy liquid bubble chamber experiment

    International Nuclear Information System (INIS)

    Fett, E.; Haatuft, A.; Olsen, J.M.

    1977-01-01

    A method is presented, which has been used to determine the pion multiplicity distributions for antiproton annihilations on free protons from a sample of events obtained in a heavy liquid bubble chamber experiment. The method uses data obtained in the experiment in question together with the usual invariance principles satisfied by strong interactions. Furthermore no particular nuclear model is assumed

  5. SMOG CHAMBER STUDIES OF SECONDARY ORGANIC AEROSOLS FROM IRRADIATED HYDROCARBONS UNDER AMBIENT CONDITIONS

    Science.gov (United States)

    Understanding the physics and chemistry of aerosols is fundamental to evaluating health risks and developing and evaluating atmospheric models. However, as noted in a recent NRC report only about 10% of the organics in PM2.5 have been identified. A significant portion of the un...

  6. SMOG-CHAMBER TOXICOLOGY BETTER ESTIMATES THE TRUE TOXIC POTENTIAL OF ATMOSPHERIC MIXTURES

    Science.gov (United States)

    The chemistry of hazardous air pollutants (HAPs) have been studied for many years, yet little is known about how these chemicals, once interacted with urban atmospheres, affect healthy and susceptible individuals. The toxic potential of these very reactive compounds once they int...

  7. Free Air Quality Alerts Help New Englanders Prepare for Summer Smog Season

    Science.gov (United States)

    With the onset of warm summer weather, the USEPA advises New Englanders to be aware of the increased risk of ground-level ozone and fine particle air pollution (when combined, often referred to as smog), & take health precautions when smog levels are high.

  8. A single exposure to photochemical smog causes airway irritation and cardiac dysrhythmia in mice

    Science.gov (United States)

    The data presented here shows that a single exposure to photochemical smog causes airway irritation and cardiac dysrhythmia in mice. Smog, which is a complex mixture of particulate matter and gaseous irritants (ozone, sulfur dioxide, reactive aldehydes), as well as components whi...

  9. DELPHI time projection chamber

    CERN Multimedia

    1989-01-01

    The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  10. Interaction of light and atmospheric photochemical products (smog) within plants. [Phaseolius vulgaris; Petunia hydrida

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, O C; Dugger, W M; Cardiff, E A; Darley, E F

    1961-12-02

    Damage to plants from ozone and peroxyacetyl nitrate, two photochemically formed components of smog, has been described. However, variations in symptom expression and the degree of damage caused by a given concentration of these components, whether of synthetic or natural origin, have complicated development of an adequate biological assay method for these materials. These observed variations in symptomatology have implicated stomatal action, inorganic nutrition temperature, genetics, ascorbic acid content, physiological age of tissue and photoperiod. Plants grown under artificial illumination differ in their response to the photochemically formed pollutants as compared with plants grown in the greenhouse. Interactions between light and oxidants from the polluted atmosphere within plants, as reported here, might well explain some of the variabilities in symptomatology observed in earlier controlled experiments as well as the unexplained natural variability observed in the Los Angeles area. The results presented also emphasize the importance of standardizing plant growth conditions for future work of this nature. 10 references.

  11. Validation of a δ2Hn-alkane-δ18Ohemicellulose based paleohygrometer: Implications from a climate chamber experiment

    Science.gov (United States)

    Hepp, Johannes; Kathrin Schäfer, Imke; Tuthorn, Mario; Wüthrich, Lorenz; Zech, Jana; Glaser, Bruno; Juchelka, Dieter; Rozanski, Kazimierz; Zech, Roland; Mayr, Christoph; Zech, Michael

    2017-04-01

    Leaf wax-derived biomarkers, e.g. long chain n-alkanes and fatty acids, and their hydrogen isotopic composition are proved to be of a value in paleoclimatology/-hydrology research. However, the alteration of the isotopic signal as a result of the often unknown amount of leaf water enrichment challenges a direct reconstruction of the isotopic composition of paleoprecipitation. The coupling of ^2H/^1H results of leaf wax-derived biomarkers with 18O/16O results of hemicellulose-derived sugars has the potential to overcome this limitation and additionally allows reconstructing relative air humidity (RH) (Zech et al., 2013). This approach was recently validated by Tuthorn et al. (2015) by applying it to topsoil samples along a climate transect in Argentina. Accordingly, the biomarker-derived RH values correlate significantly with modern actual RH values from the respective study sites, showing the potential of the established 'paleohygrometer' approach. However, a climate chamber validation study to answer open questions regarding this approach, e.g. how robust biosynthetic fractionation factors are, is still missing. Here we present coupled δ2Hn-alkane-δ18Ohemicellulose results obtained for leaf material from a climate chamber experiment, in which Eucalyptus globulus, Vicia faba and Brassica oleracea were grown under controlled conditions (Mayr, 2003). First, the 2H and 18O enrichment of leaf water strongly reflects actual RH values of the climate chambers. Second, the biomarker-based reconstructed RH values correlate well with the actual RH values of the respective climate chamber, validating the proposed 'paleohygrometer' approach. And third, the calculated fractionation factors between the investigated leaf biomarkers (n-C29 and n-C31 for alkanes; arabinose and xylose for hemicellulose) and leaf water are close to the expected once reviewed from the literature (+27\\permil for hemicellulose; -155\\permil for n-alkanes). Nevertheless, minor dependencies of these

  12. Chamber transport

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2001-01-01

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system

  13. Ambient air pollution, smog episodes and mortality in Jinan, China.

    Science.gov (United States)

    Zhang, Jun; Liu, Yao; Cui, Liang-Liang; Liu, Shou-Qin; Yin, Xi-Xiang; Li, Huai-Chen

    2017-09-11

    We aimed to assess the acute effects of ambient air pollution and weather conditions on mortality in the context of Chinese smog episodes. A total of 209,321 deaths were recorded in Jinan, a large city in eastern China, during 2011-15. The mean concentrations of daily particulate matter ≤10 μm (PM 10 ), fine particulate matter (PM 2.5 ), sulfur dioxide (SO 2 ) and nitrogen dioxide (NO 2 ) were 169 μg/m 3 , 100 μg/m 3 , 77 μg/m 3 , and 54 μg/m 3 , respectively. Increases of 10 μg/m 3 in PM 10 , PM 2.5 , SO 2 and NO 2 were associated with 1.11% (95% CI 0.96-1.26%), 0.71% (95% CI 0.60-0.82%), 1.69% (95% CI 1.56-1.83%), and 3.12% (95% CI 2.72-3.53%) increases in daily non-accidental mortality rates, respectively. Moreover, the risk estimates for these 4 pollutants were higher in association with respiratory and cardiovascular mortality. The effects of all the evaluated pollutants on mortality were greater in winter than in summer. Smog episodes were associated with a 5.87% (95% CI 0.16-11.58%) increase in the rate of overall mortality. This study highlights the effect of exposure to air pollution on the rate of mortality in China.

  14. 2006 Toronto smog report card : final grade C-

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This annual report card evaluated the progress made by the City of Toronto toward reducing the environmental and health impacts of smog. The final grade for 2006 was a C-, the same as for 2005. The highest grade of B+ was issued in 2004. The report card evaluated City Council actions based on their clean air commitments. Although the summer of 2006 was one of the best on record, with only 11 smog days, the grade of C- was issued because the performance of the City's Air Quality Improvement record was poor. Toronto Environmental Alliance strongly recommended that important changes be made to improve air quality, transit and waste disposal. It recommended that the City should address the real causes of unclean air, which are motor vehicle exhaust and toxic pollution. This report card graded the performance on initiatives in the following six major areas: energy; transit; air quality plan; walking and biking; fleets and fuels; and, intergovernmental action. The report recommended that efforts should be made to reduce greenhouse gas emissions which cause global warming. refs., tabs., figs.

  15. Evaluation of Kinetic and Mechanistic Data for Modeling of Photochemical Smog

    International Nuclear Information System (INIS)

    Atkinson, R.; Lloyd, A.C.

    1984-01-01

    This review is a critical evaluation of the rate constants, mechanisms, and products of selected atmospheric reactions of hydrocarbons, nitrogen oxides, and sulfur oxides in air. The evaluation considers eight hydrocarbons (n-butane, 2,3-dimethylbutane, ethene, propene, 1-butene, trans-2-butene, toluene, and m-xylene) for which smog chamber irradiations have been carried out under carefully controlled conditions and which have been the subject of computer modeling studies by more than one research group. The reactions involved are treated in the following categories: inorganic reactions in organic-NO/sub x/-air irradiations; organic reactions of the formaldehyde-NO/sub x/-air system; organic reactions of the acetaldehyde-NO/sub x/-air system; organic reactions of the alkene-NO/sub x/-air systems; organic reactions of the alkane-NO/sub x/-air systems; organic reactions of selected carbonyl-NO/sub x/-air systems; organic reactions of the aromatic-NO/sub x/-air systems; combination reactions of peroxy radicals, and homogeneous gas phase SO 2 reactions. This report considers literature through early 1983

  16. Peculiarities occurrence and microstrip gas chambers studied through experiment WA97; La production d`etrangete et les chambres gazeuses a micropistes dans le cadre de l`experience WA97

    Energy Technology Data Exchange (ETDEWEB)

    Kachelhoffer, T.

    1995-04-01

    This paper presents the studies on development of a Monte-Carlo type generator used for inclusive production of odd baryons and antibaryons through proton- proton and proton- nucleus collisions. Experiment WA97 consisted in designing simulation software for MSGCs (Micro-strips Gas Chambers) as well as the redefining of particle paths with the help of these chambers. This work made it possible to design the MSGC detector for experiment WA97. (TEC). 71 refs., 88 figs.

  17. Test and performances of the RPC trigger chambers of the ATLAS experiment at LHC

    CERN Document Server

    Aielli, G; Ammosov, A; Biglietti, M; Brambilla, Elena; Camarri, P; Canale, V; Caprio, M A; Cardarelli, R; Carlino, G; Cataldi, G; Chiodini, G; Di Simone, A; Di Ciaccio, A; Della Volpe, D; De Asmundis, R; Della Pietra, M; Grancagnolo, F; Gorini, E; Iengo, P; Liberti, B; Patricelli, S; Perrino, R; Primavera, M; Santonico, R; Sehkniadze, G; Spagnolo, S; Sviridov, Yu; Zaetz, V G

    2004-01-01

    RPCs will be used as trigger detectors in the barrel region of the Muon Spectrometer of the ATLAS experiment at LHC. The total number of RPC units to be installed is 1088, covering a total surface of about 3500m**2. ATLAS RPCs work in avalanche mode with C//2H//2F //4/C//4H //1//0/SF//6 (94.7%/5%/0.3%) gas mixture. A cosmic ray test stand has been designed and built in Naples laboratories in order to carry out a complete test of the ATLAS RPC units. Since August 2002 about 300 units have been tested. A description of the test stand, test procedure and results are presented.

  18. Analysis of high mass resolution PTR-TOF mass spectra from 1,3,5-trimethylbenzene (TMB) environmental chamber experiments

    Science.gov (United States)

    Müller, M.; Graus, M.; Wisthaler, A.; Hansel, A.; Metzger, A.; Dommen, J.; Baltensperger, U.

    2012-01-01

    A series of 1,3,5-trimethylbenzene (TMB) photo-oxidation experiments was performed in the 27-m3 Paul Scherrer Institute environmental chamber under various NOx conditions. A University of Innsbruck prototype high resolution Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF) was used for measurements of gas and particulate phase organics. The gas phase mass spectrum displayed ~200 ion signals during the TMB photo-oxidation experiments. Molecular formulas CmHnNoOp were determined and ion signals were separated and grouped according to their C, O and N numbers. This allowed to determine the time evolution of the O:C ratio and of the average carbon oxidation state solid #000; color: #000;">OSC of the reaction mixture. Both quantities were compared with master chemical mechanism (MCMv3.1) simulations. The O:C ratio in the particle phase was about twice the O:C ratio in the gas phase. Average carbon oxidation states of secondary organic aerosol (SOA) samples solid #000; color: #000;">OSCSOA were in the range of -0.34 to -0.31, in agreement with expected average carbon oxidation states of fresh SOA (solid #000; color: #000;">OSC = -0.5-0).

  19. Electro smog. Health risks, limiting values, consumer protection

    International Nuclear Information System (INIS)

    Karus, M.; Ebert, L.; Schneider, W.; Koehnecke, W.; Loefflad, H.; Plotzke, O.; Niessen, P.

    1994-01-01

    At first, the popular book describes physical facts. All terms and units being necessary for the comprehension of electro smog are presented and referred to practice: Which electric and magnetic fields of natural and technical origin appear in everyday life? The main part of the book occupies physical effects. The current scientific state of the research is presented: Are electric and magnetic fields a physical risk factor? In the chapter 'limiting values', the valid limiting values and their conceptional and political basis are discussed. The last part of the book addresses consumer protection: How can the own load be reduced through electric and magnetic fields of electric devices and installations, computers and mobile telephones without renouncing of electric comfort. (VHE) [de

  20. The evolution of photochemical smog in a power plant plume

    Science.gov (United States)

    Luria, Menachem; Valente, Ralph J.; Tanner, Roger L.; Gillani, Noor V.; Imhoff, Robert E.; Mueller, Stephen F.; Olszyna, Kenneth J.; Meagher, James F. Present address: Aeronomy Laboratory, NOAA, 325 Broadway, Boulder CO 80303, USA.)

    The evolution of photochemical smog in a plant plume was investigated with the aid of an instrumented helicopter. Air samples were taken in the plume of the Cumberland Power Plant, located in central Tennessee, during the afternoon of 16 July 1995 as part of the Southern Oxidants Study - Nashville Middle Tennessee Ozone Study. Twelve cross-wind air sampling traverses were made at six distance groups from 35 to 116 km from the source. During the sampling period the winds were from the west-northwest and the plume drifted towards the city of Nashville TN. Ten of the traverses were made upwind of the city, where the power plant plume was isolated, and two traverses downwind of the city when the plumes were possibly mixed. The results revealed that even six hours after the release, excess ozone production was limited to the edges of the plume. Only when the plume was sufficiently dispersed, but still upwind of Nashville, was excess ozone (up to 109 ppbv, 50-60 ppbv above background levels) produced in the center of the plume. The concentrations image of the plume and a Lagrangian particle model suggests that portions of the power plant plume mixed with the urban plume. The mixed urban power plant plume began to regenerate O 3 that peaked at 120 ppbv at a short distance (15-25 km) downwind of Nashville. Ozone productivity (the ratio of excess O 3 to NO y and NO z) in the isolated plume was significantly lower compared with that found in the city plume. The production of nitrate, a chain termination product, was significantly higher in the power plant plume compared to the mixed plume, indicating shorter chain length of the photochemical smog chain reaction mechanism.

  1. The evolution of photochemical smog in a power plant plume

    International Nuclear Information System (INIS)

    Luria, M.; The Hebrew University, Jerusalem; Valente, R.J.; Tanner, R.L.; Imhoff, R.E.; Mueller, S.F.; Olszyna, K.J.; Meagher, J.F.; Gillani, N.V.; University of Alabama, Huntsville, AL

    1999-01-01

    The evolution of photochemical smog in a plant plume was investigated with the aid of an instrumented helicopter. Air samples were taken in the plume of the Cumberland Power Plant, located in central Tennessee, during the afternoon of 16 July 1995 as part of the Southern Oxidants Study - Nashville Middle Tennessee Ozone Study. Twelve cross-wind air sampling traverses were made at six distance groups from 35 to 116 km from the source. During the sampling period the winds were from the west-northwest and the plume drifted towards the city of Nashville TN. Ten of the traverses were made upwind of the city, where the power plant plume was isolated, and two traverses downwind of the city when the plumes were possibly mixed. The results revealed that even six hours after the release, excess ozone production was limited to the edges of the plume. Only when the plume was sufficiently dispersed, but still upwind of Nashville, was excess ozone (up to 109 ppbv, 50-60 ppbv above background levels) produced in the center of the plume. The concentrations image of the plume and a Lagrangian particle model suggests that portions of the power plant plume mixed with the urban plume. The mixed urban power plant plume began to regenerate O 3 that peaked at 120 ppbv at a short distance (15-25 km) downwind of Nashville. Ozone productivity (the ratio of excess O 3 to NO y and NO z ) in the isolated plume was significantly lower compared with that found in the city plume. The production of nitrate, a chain termination product, was significantly higher in the power plant plume compared to the mixed plume, indicating shorter chain length of the photochemical smog chain reaction mechanism. (author)

  2. Ussing Chamber

    NARCIS (Netherlands)

    Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

    2015-01-01

    The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

  3. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  4. The NA36 time projection chamber: An interim report on a TPC designed for a relativistic heavy ion experiment

    International Nuclear Information System (INIS)

    Diebold, G.E.

    1987-01-01

    Since its conception in the early 1970s, the Time Projection Chamber (TPC) has found application in several areas of particle physics ranging from e + e - collider experiments to rare decay studies of lepton nonconservation. A new and promising area of application for the TPC is the study of relativistic heavy ion collisions (RHIC). Presented here is an interim report on the first TPC for this field of physics, the NA36 TPC, being developed by Berkeley (LBL) for RHIC at the CERN SPS. Emphasis is placed on the operational and design considerations implemented to optimize the performance of the NA36 TPC in the study of central rapidity strange baryons produced in RHIC. The NA36 TPC volume is rectangular with an endcap area 0.5 m x 1.0 m and a maximum drift distance of 0.5 m. The drift volume is filled with Ar-CH 4 (9%) at one atmosphere. A total of 6400 channels of time digitizing electronics instrument 66% of the endcap in a wedge shaped area matched to fixed target kinematics. 6 refs., 5 figs

  5. Evaluation of the tolerance of three cultivars of barley to Zn, Cd or Cr in a growth chamber experiment

    Directory of Open Access Journals (Sweden)

    González A.

    2013-04-01

    Full Text Available To evaluate the tolerance of three cultivars of barley for the phytoremediation of soils contaminated by metals, a growth chamber experiment with plants exposed to increasing concentrations of Zn, Cd and Cr was conducted. Growth parameters, chlorophyll content and chlorophyll fluorescence were measured at 15 and 29 days after treatment application. Metal concentration in the plant was also measured. In all cases, the amount of metal accumulated in the plant increased by increasing the concentration of the applied metal. Chlorophyll content and chlorophyll fluorescence were higher in the first sampling indicating the negative effect on these parameters of the highest metal concentrations. Cr treatments affected significantly plant growth. Height and dry weights plants were significantly lower (p <0.05 than those treated with Zn and Cd. Physiological parameters measured and water content were also lower in plants treated with Cr. Plaisant and Pedrezuela varieties accumulated more Zn and Cd than Reinette, which accumulated greater amount of Cr than the other two cultivars. This fact shows the interest in selecting the most tolerant varieties when using a crop for phytoremediation of contaminated soils.

  6. Effects of SF$_{6}$ on the avalanche mode operation of a real-sized double-gap resistive plate chamber for the Compact Muon Solenoid experiment

    CERN Document Server

    Ahn Sung Hwan; Hong, B; Hong, S J; Ito, M; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee, H W; Lee, K B; Lee, K S; Lee, S J; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee, J T; Ryu, M S; Shim, H H; Sim, K S; Kang, T I

    2005-01-01

    We present the design and the test, results for a real-sized prototype resistive plate chamber by using cosmic-ray muons for the forward region of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). In particular, we investigate the effects of adding SF/sub 6/ to the gas mixture for the avalanche mode operation of a resistive plate chamber. A small fraction of SF/sub 6/ is very effective in suppressing streamer signals in a resistive plate chamber. The shapes of the muon detection efficiency and the muon cluster size remain similar, but are shifted to higher operating voltage by SF/sub 6/. The noise cluster rate and size are not influenced by SF/sub 6/.

  7. Drift chamber

    International Nuclear Information System (INIS)

    Inagaki, Yosuke

    1977-01-01

    Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

  8. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  9. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  10. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  11. Bio-mimic design of PM2.5 anti-smog masks

    Directory of Open Access Journals (Sweden)

    Shen Jing

    2014-01-01

    Full Text Available The basic property of anti-smog masks is to block PM2.5 with excellent air permeability. A multi-layer nanofiber woven fabric with hierarchical structure is the best candidate for this purpose.

  12. Effects of Isoprene- and Toluene-Generated Smog on Allergic Inflammation in Mice

    Science.gov (United States)

    Reactions of organic compounds with nitric oxide (NO) and sunlight produce complex mixtures of pollutants including secondary organic aerosol (SOA), ozone (O3), nitrogen dioxide (NO2), and reactive aldehydes. The health effects of these photochemical smog mixtures in susceptible ...

  13. Ionization chamber

    International Nuclear Information System (INIS)

    1977-01-01

    An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  14. Ionization chambers

    International Nuclear Information System (INIS)

    Boag, J.W.

    1987-01-01

    Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

  15. Characteristics of activated carbon remove sulfur particles against smog.

    Science.gov (United States)

    Ge, Shengbo; Liu, Zhenling; Furuta, Yuzo; Peng, Wanxi

    2017-09-01

    Sulfur particles, which could cause diseases, were the main powder of smog. And activated carbon had the very adsorption characteristics. Therefore, five sulfur particles were adsorbed by activated carbon and were analyzed by FT-IR. The optimal adsorption time were 120 min of Na 2 SO 3 , 120 min of Na 2 S 2 O 8 , 120 min of Na 2 SO 4 , 120 min of Fe 2 (SO 4 ) 3 and 120 min of S. FT-IR spectra showed that activated carbon had the eight characteristic absorption of S-S stretch, H 2 O stretch, O-H stretch, -C-H stretch, conjugated C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 O stretch or CC stretch, CH 2 bend, C-O stretch and acetylenic C-H bend vibrations at 3850 cm -1 , 3740 cm -1 , 3430 cm -1 , 2920 cm -1 , 1630 cm -1 , 1390 cm -1 , 1110 cm -1 and 600 cm -1 , respectively. For Na 2 SO 3 , the peaks at 2920 cm -1 , 1630 cm -1 , 1390 cm -1 and 1110 cm -1 achieved the maximum at 20 min. For Na 2 S 2 O 8 , the peaks at 3850 cm -1 , 3740 cm -1 and 2920 cm -1 achieved the maximum at 60 min. The peaks at 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 40 min. For Na 2 SO 4 , the peaks at 3430 cm -1 , 2920 cm -1 , 1630 cm -1 , 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 60 min. For Fe 2 (SO 4 ) 3 , the peaks at 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 20 min. For S, the peaks at 1630 cm -1 , 1390 cm -1 and 600 cm -1 achieved the maximum at 120 min. It provided that activated carbon could remove sulfur particles from smog air to restrain many anaphylactic diseases.

  16. Metagenomic profiling of ARGs in airborne particulate matters during a severe smog event.

    Science.gov (United States)

    Hu, Jialin; Zhao, Fuzheng; Zhang, Xu-Xiang; Li, Kan; Li, Chaoran; Ye, Lin; Li, Mei

    2018-02-15

    Information is currently limited regarding the distribution of antibiotic resistance genes (ARGs) in smog and their correlations with airborne bacteria. This study characterized the diversity and abundance of ARGs in the particulate matters (PMs) of severe smog based on publicly available metagenomic data, and revealed the occurrence of 205 airborne ARG subtypes, including 31 dominant ones encoding resistance to 11 antibiotic types. Among the detectable ARGs, tetracycline, β-lactam and aminoglycoside resistance genes had the highest abundance, and smog and soil had similar composition characteristics of ARGs. During the smog event, the total abundance of airborne ARGs ranged from 4.90 to 38.07ppm in PM 2.5 samples, and from 7.61 to 38.49ppm in PM 10 samples, which were 1.6-7.7 times and 2.1-5.1 times of those in the non-smog day, respectively. The airborne ARGs showed complicated co-occurrence patterns, which were heavily influenced by the interaction of bacterial community, and physicochemical and meteorological factors. Lactobacillus and sulfonamide resistance gene sul1 were determined as keystones in the co-occurrence network of microbial taxa and airborne ARGs. The results may help to understand the distribution patterns of ARGs in smog for the potential health risk evaluation. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Assessing the features of extreme smog in China and the differentiated treatment strategy

    Science.gov (United States)

    Deng, Lu; Zhang, Zhengjun

    2018-01-01

    Extreme smog can have potentially harmful effects on human health, the economy and daily life. However, the average (mean) values do not provide strategically useful information on the hazard analysis and control of extreme smog. This article investigates China's smog extremes by applying extreme value analysis to hourly PM2.5 data from 2014 to 2016 obtained from monitoring stations across China. By fitting a generalized extreme value (GEV) distribution to exceedances over a station-specific extreme smog level at each monitoring location, all study stations are grouped into eight different categories based on the estimated mean and shape parameter values of fitted GEV distributions. The extreme features characterized by the mean of the fitted extreme value distribution, the maximum frequency and the tail index of extreme smog at each location are analysed. These features can provide useful information for central/local government to conduct differentiated treatments in cities within different categories and conduct similar prevention goals and control strategies among those cities belonging to the same category in a range of areas. Furthermore, hazardous hours, breaking probability and the 1-year return level of each station are demonstrated by category, based on which the future control and reduction targets of extreme smog are proposed for the cities of Beijing, Tianjin and Hebei as an example.

  18. Tests of the data acquisition system and detector control system for the muon chambers of the CMS experiment at the LHC

    International Nuclear Information System (INIS)

    Sowa, Michael Christian

    2009-01-01

    The Phys. Inst. III A of RWTH Aachen University is involved in the development, production and tests of the Drift Tube (DT) muon chambers for the barrel muon system of the CMS detector at the LHC at CERN (Geneva). The present thesis describes some test procedures which were developed and performed for the chamber local Data Acquisition (DAQ) system, as well as for parts of the Detector Control System (DCS). The test results were analyzed and discussed. Two main kinds of DAQ tests were done. On the one hand, to compare two different DAQ systems, the chamber signals were split and read out by both systems. This method allowed to validate them by demonstrating, that there were no relevant differences in the measured drift times, generated by the same muon event in the same chamber cells. On the other hand, after the systems were validated, the quality of the data was checked. For this purpose extensive noise studies were performed. The noise dependence on various parameters (threshold,HV) was investigated quantitatively. Also detailed studies on single cells, qualified as ''dead'' and ''noisy'' were done. For the DAQ tests a flexible hardware and software environment was needed. The organization and installation of the supplied electronics, as well as the software development was realized within the scope of this thesis. The DCS tests were focused on the local gas pressure read-out components, attached directly to the chamber: pressure sensor, manifolds and the pressure ADC (PADC). At first it was crucial to proof, that the calibration of the mentioned chamber components for the gas pressure measurement is valid. The sensor calibration data were checked and possible differences in their response to the same pressure were studied. The analysis of the results indicated that the sensor output depends also on the ambient temperature, a new experience which implied an additional pedestal measurement of the chamber gas pressure sensors at CMS. The second test sequence

  19. The influence of aerosols on photochemical smog in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Castro, T.; Mar, B. [UNAM, Mexico, Centro de Ciencias de la Atmosfera (Mexico); Madronich, S.; Rivale, S. [National Center for Atmospheric Research, Boulder, CO (United States); Muhlia, A. [UNAM, Mexico, Inst. de Geofysica (Mexico)

    2001-04-01

    Aerosols in the Mexico City atmosphere can have a non-negligible effect on the ultraviolet radiation field and hence on the formation of photochemical smog. We used estimates of aerosol optical depths from sun photometer observations in a detailed radiative transfer model, to calculate photolysis rate coefficients (J{sub NO2}) for the key reaction NO{sub 2}+h{nu}{yields}NO+O ({lambda}<430nm). The calculated values are in good agreement with previously published measurements of J{sub NO2} at two sites in Mexico City: Palacio de Mineria (19 degrees 25'59''N, 99 degrees 07'58''W, 2233masl), and IMP (19 degrees 28'48''N, 99 degrees 11'07''W, 2277masl) and in Tres Marias, a town near Mexico City (19 degrees 03'N, 99 degrees 14'W, 2810masl). In particular, the model reproduces very well the contrast between the two urban sites and the evidently much cleaner Tres Marias site. For the measurement days, reductions in surface J{sub NO2} by 10-30% could be attributed to the presence of aerosols, with considerable uncertainty due largely to lack of detailed data on aerosol optical properties at ultraviolet wavelengths (esp. the single scattering albedo). The potential impact of such large reductions in photolysis rates on surface ozone concentrations is illustrated with a simple zero-dimensional photochemical model. (Author)

  20. The vacuum chamber in the interaction region of particle colliders a historical study and developments implementations in the LHCb experiment at CERN

    CERN Document Server

    Knaster, J R; Gamez-Mejias, L

    2004-01-01

    The history of particle colliders begins in the early 60's when an idea previously patented by R. Wideroe in 1953 is constructed. The design of the vacuum chamber in their experimental area became essential as it was the rst physical barrier that the particles to be detected needed to traverse. The interaction of the products of the collisions with the vacuum chamber structural materials, hindered the identification of the significative events. This Thesis analyses the historical evolution of the experimental vacuum chambers and summarizes the technical criteria that are to be fulfilled. The Large Hadron Collider (LHC) presently under construction at CERN is the last generation of particle colliders. Four big experiments will be in operation (ATLAS, CMS, ALICE and LHCb) in the LHC with diferent physics objectives. In particular, LHCb will be devoted to the study of CP violation and the design of its vacuum chamber is the scope of this Thesis. Physics simulations with an initial design consisting of a conical ...

  1. Study on a drift chamber for high energy experiments; Estudos sobre uma camara de arrasto para um experimento de altas energias

    Energy Technology Data Exchange (ETDEWEB)

    Puget, Maria Augusta Constante

    1993-12-31

    This work deals with the studies of a multiwire gaseous detector operating as a drift chamber, which will be part of the SELEX spectrometer of the experiment Fermilab E781. A prototype was designed to be built and tested at IFUSP. Results are shown of the analysis of data taken with another similar detector whose construction and test were done at Fermilab, with the aim of studying its characterization and performance. (author) 35 refs., 54 figs., 17 tabs.

  2. Study on a drift chamber for high energy experiments; Estudos sobre uma camara de arrasto para um experimento de altas energias

    Energy Technology Data Exchange (ETDEWEB)

    Puget, Maria Augusta Constante

    1994-12-31

    This work deals with the studies of a multiwire gaseous detector operating as a drift chamber, which will be part of the SELEX spectrometer of the experiment Fermilab E781. A prototype was designed to be built and tested at IFUSP. Results are shown of the analysis of data taken with another similar detector whose construction and test were done at Fermilab, with the aim of studying its characterization and performance. (author) 35 refs., 54 figs., 17 tabs.

  3. Conception and test of an integrated circuit (ASIC): application to multiwire chambers and photomultipliers of the GRAAL experience

    International Nuclear Information System (INIS)

    Bugnet, H.

    1995-01-01

    The nuclear physics project GRAAL (GRenoble Anneau Accelerateur Laser) located at the European Synchrotron Radiation Facility (ESRF) in Grenoble produces a high energy photon beam with a maximum energy of 1.5 GeV. This gamma beam is obtained by Compton backscattering and can be polarized easily. It permits to probe, in an original way, the structure of the nucleon. The associated detector system includes multiwire proportional chambers and scintillator hodoscopes. A kit of six ASICs (Application Specific Integrated Circuit) has been developed and used for the signal processing and data conditioning up to the level of the data acquisition. This integrated electronics can be mounted right on the detectors. Obvious advantages, due to the reduction of the length of the wires and the number of connections, are an improvement of the signal quality and an increase of the reliability. The Wire Processor (WP), ASIC designed and tested during this thesis, treats the signals from the chamber wires and the photomultipliers. In one chip, there are two identical channels permitting the amplification, the amplitude discrimination, the generation of a programmable delay and the writing in a two state memory in case of coincidence with an external strobe signal. The measurement of the multiwire chamber efficiency demonstrates the functioning of the WP, the data conditioning electronics, the data acquisition and the chamber itself. (author). 62 refs., 111 figs., 13 tabs

  4. Muon Chamber Endcap Upgrade of the CMS Experiment with Gas Electron Multiplier (GEM) Detectors and their Performance

    CERN Document Server

    Gola, Mohit

    2017-01-01

    As the CERN LHC is heading towards a high luminosity phase a very high flux is expected in the endcaps of the CMS Detector. The presence of muons in collision events can be due to rare or new physics so it is important to maintain the high trigger efficiency of the CMS muon system. The CMS Collaboration has proposed to instrument the high-eta region (1.6 lt IetaI lt 2.2) of the muon endcaps with Gas Electron Multiplier (GEM) detectors, referred to as GE1/1 chambers, during the LS2. This technology will help in maintaining optimum trigger performance with maximum selection efficiency of muons even in a high flux environment. We describe plans for a Slice Test to installa few GE1/1 chambers covering 50 degrees in azimuthal angle within the CMS detector in 2017, with subsequent operation during the current Run 2 of the LHC. We show the performance of the GE1/1 chambers to be installed during the slice test, specifically GEM foil leakage currents, chamber gas volume integrity, high voltage circuit performanc...

  5. Cloud Chamber

    DEFF Research Database (Denmark)

    Gfader, Verina

    Cloud Chamber takes its roots in a performance project, titled The Guests 做东, devised by Verina Gfader for the 11th Shanghai Biennale, ‘Why Not Ask Again: Arguments, Counter-arguments, and Stories’. Departing from the inclusion of the biennale audience to write a future folk tale, Cloud Chamber......: fiction and translation and translation through time; post literacy; world picturing-world typing; and cartographic entanglements and expressions of subjectivity; through the lens a social imaginary of worlding or cosmological quest. Art at its core? Contributions by Nikos Papastergiadis, Rebecca Carson...

  6. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  7. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  8. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  9. Gas and particle phase chemical characterization of photochemical smog in Beijing and Hong Kong

    Science.gov (United States)

    Hallquist, Mattias; Le Breton, Michael; Guo, Song; Zhen Yu, Jian; Hallquist, Åsa. M.; Pathak, Ravi K.; Liu, Qianyun; Wang, Yuchen; Li, Jinjian; Chan, Chak K.; Wang, Yujue; Zheng, Jing; Yang, Yudong; Lu, Keding; Wu, Zhijun; Hu, Min

    2017-04-01

    Secondary chemistry transforming primary pollutants is of high relevance for Chinese photochemical smog. In particular, formation of ozone (O3) and particulate matter (PM), including Secondary Organic Aerosols (SOA), are of major concern regarding impacts on health, climate and ecosystems. The atmospheric oxidation processes leading to SOA formation are complex and involves thousands of different compounds, both of biogenic and anthropogenic origin. Furthermore, for a thorough understanding both the gas and the particle phase need to be considered. As part of an intercollaborative project to assess the photochemical smog in China, two major field campaigns were arranged in 2016; in Changping, Bejing during springtime and at HKUST, Hong Kong during the autumn. Alongside with other advanced instrumentations, a Time of Flight Chemical Ionisation Mass Spectrometer (ToF CIMS) utilising the Filiter Inlet for Gases and AEROsols (FIGAERO) was used to chemically characterize the gas and the particle phase. This specific instrument applies soft ionization limiting the fragmentation and one can usually identify molecular composition of hundreds of different parent molecules. In both Beijing and Hong Kong the iodide ionization scheme was utilised, making it possible to specifically detect oxygenated compounds such as carboxylic acids, organic nitrates and sulphates as well as some inorganic compounds e.g. N2O5, ClNO2, and HONO. For numerous compounds significant levels were detected in both the gas and particle phase enabling evaluation of partitioning and gas-to-particle transformation and its relationship to atmospheric conditions and estimated vapour pressures. Furthermore, the detection of molecular markers such as levoglucosan, C6H5NO3, C10H16NSO7, C5H8SO7, C5H8O4 can support source apportionment and atmospheric process description. In order to further investigate atmospheric ageing/processing a portable laminar flow reactor (Go:PAM) was for selected periods utilized to

  10. Should people be physically active outdoors on smog alert days?

    Science.gov (United States)

    Campbell, Monica E; Li, Qian; Gingrich, Sarah E; Macfarlane, Ronald G; Cheng, Shouquan

    2005-01-01

    Given the importance of physical activity to well-being, there is a need to encourage people to be physically active year-round. At the same time, many people are vulnerable to adverse health effects from air pollution, especially on smog alert days. This study was undertaken to determine when air pollution levels tend to be lowest so that the public can modify strenuous outdoor activity accordingly. Existing hourly air pollution data for Toronto were analyzed to determine how pollutant levels varied from hour to hour throughout each 24-hour day, to identify the times when pollution levels are at their lowest on average. Pollutant levels vary throughout the day, with concentrations of some pollutants (such as ozone, particles and sulphur dioxide) being highest during mid-day, and others (such as carbon monoxide and nitrogen dioxide) being highest with morning rush hour. Overall, pollutant concentrations tend to be lowest before seven a.m. and after eight p.m. The public should be encouraged to maintain regular physical activity outdoors while monitoring any air pollution-related symptoms. The intensity of outdoor activity should be reduced, or activities replaced with indoor exercise, at those Air Quality Index (AQI) levels that trigger individual symptoms and when AQI values exceed 50. Where possible, strenuous activity should be taken when and where air pollution levels tend to be lowest, namely early in the morning and in low-traffic areas. More research is required to guide development of health protective advice on exercising when air quality is poor.

  11. The upgrade of the multiwire drift chamber readout of the HADES experiment at GSI: the optical end point board

    Energy Technology Data Exchange (ETDEWEB)

    Tarantola, Attilio; Michel, Jan; Muentz, Christian; Stroth, Joachim [Institut fuer Kernphysik, Goethe-Universitaet, Frankfurt (Germany); GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Froehlich, Ingo; Stroebele, Herbert [Institut fuer Kernphysik, Goethe-Universitaet, Frankfurt (Germany); Kolb, Burkhard; Traxler, Michael [GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Palka, Marek [Smoluchowski Institute of Physics, Jagiellonian University, Krakow (Poland); GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Wuestenfeld, Joern [Institut fuer Strahlenphysik, Forschungszentrum, Dresden-Rossendorf (Germany)

    2009-07-01

    One of the goal of the HADES upgrade project is the realization of a new data acquisition scheme for the 24 Multiwire Drift Chambers (MDCs), which allows to increase the readout speed of the 40.000 TDC channels. On the existing MDC Front End Electronic (FEE) side an Optical End Point Board (OEPB) has been designed to control configuration and readout of the chamber's TDCs. The OEPB uses Plastic Optical Fibres (POF) for data transmission, which results in total electromagnetic immunity, amazing simplicity in handling and low power consumption. The employment of a Lattice ECP2/M FPGA with SERDES manages serial data transmission and its large resources allow for the storage of several events close-to-front-end. As 400 OEPBs will be located in the detector acceptance, dedicated FPGA hardware is used to detect Single Event Upsets (SEUs).

  12. A Questionnaire Case Study to Investigate Public Awareness of Smog Pollution in China’s Rural Areas

    Directory of Open Access Journals (Sweden)

    Li Jiang

    2016-10-01

    Full Text Available Smog pollution is one of China’s most pressing public health issues today and has therefore received significant attention worldwide. Not only cities but also villages in China are suffering from smog pollution, especially since 2013. However, there is limited information available about public awareness on smog pollution in China, especially for where it concerns the residents living in villages. Based on a questionnaire survey, this study aims to help fill this gap. The results of the study show that the income of the majority of respondents comes from working in the city, accounting for 31.6% of the total income. The percentages for respondents related to access to smog information from various channels are as follows: TV (28.5%, radio (24.2%, neighbors (13.5%, Internet (9.8%, newspapers (8.3% and others (7.8%. As for attitudes regarding the severity degree and main cause of smog pollution, most respondents (33.7% thought smog pollution in villages was somewhat severe, while 26.3% agreed that the main contributor to smog pollution was industrial emissions, followed by coal burning at power plants (20.9% and vehicle emissions (17.7%. The results also indicate that most of the respondents were satisfied with the government’s performance in terms of smog control. However, 67.9% of respondents indicated they would remain silent and not intervene when confronted by an activity that causes smog pollution. This study can help to improve an understanding of public awareness regarding smog pollution in China’s rural areas and thereby activate positive public participation in smog pollution prevention and management in the search for sustainable development.

  13. The KLOE drift chamber

    International Nuclear Information System (INIS)

    Ferrari, A.

    2002-01-01

    The design and construction of the large drift chamber of the KLOE experiment is presented. The track reconstruction is described, together with the calibration method and the monitoring systems. The stability of operation and the performance are studied with samples of e + e - , K S K L and K + K - events

  14. OPAL Muon Chamber

    CERN Multimedia

    OPAL was one of the 4 experiments installed at the LEP particle accelerator from 1989 to 2000. This is a slice of the outermost layer of OPAL : the muon chambers. This outside layer detects particles which are not stopped by the previous layers. These are mostly muons.

  15. Review of straw chambers

    International Nuclear Information System (INIS)

    Toki, W.H.

    1990-03-01

    This is a review of straw chambers used in the HRS, MAC, Mark III, CLEO, AMY, and TPC e + e - experiments. The straws are 6--8 mm in diameter, operate at 1--4 atmospheres and obtain resolutions of 45--100 microns. The designs and constructions are summarized and possible improvements discussed

  16. Microbiological Diversity Demonstrates the Potential which Collaboratively Metabolize Nitrogen Oxides ( NOx) under Smog Environmental Stress

    Science.gov (United States)

    Chen, X. Z.; Zhao, X. H.; Chen, X. P.

    2018-03-01

    Recently, smoggy weather has become a daily in large part of China because of rapidly economic growth and accelerative urbanization. Stressed on the smoggy situation and economic growth, the green and environment-friendly technology is necessary to reduce or eliminate the smog and promote the sustainable development of economy. Previous studies had confirmed that nitrogen oxides ( NOx ) is one of crucial factors which forms smog. Microorganisms have the advantages of quickly growth and reproduction and metabolic diversity which can collaboratively Metabolize various NOx. This study will design a kind of bacteria & algae cultivation system which can metabolize collaboratively nitrogen oxides in air and intervene in the local nitrogen cycle. Furthermore, the nitrogen oxides can be transformed into nitrogen gas or assembled in protein in microorganism cell by regulating the microorganism types and quantities and metabolic pathways in the system. Finally, the smog will be alleviated or eliminated because of reduction of nitrogen oxides emission. This study will produce the green developmental methodology.

  17. Air quality plans unveiled at Toronto's first Smog Summit

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-06-23

    New federal and provincial initiatives to improve air quality were announced at the recent first-ever Toronto Smog Summit. An initial one million dollars have been pledged by the federal Minister of the Environment to support a framework for extending daily air quality forecasting across Canada, to begin within the next year. The funding will be used to increase the information base of existing air quality advisory programs in Ontario, and to create a daily air quality index immediately in other areas of the country most affected by smog. Existing air quality assessment programs will be expanded to include air quality models incorporating measurement and reporting of particulate matter levels. A second federal initiative also announced at the is meeting will be a corporate smog action plan, led by the Ontario regional offices of the federal departments of the Environment, Health Canada, and Public Works and Government Services. This program will include rapid response by federal government departments during Smog Alerts Days and measures to reduce the federal government's contribution to causing smog through encouragement of low or no emission options for employees, educational programs on best practices at home and at the office, reduction of employee travel through flextime and telecommuting, conversion of government vehicles to natural gas and other alternatives, and retrofitting government buildings for greater energy and water efficiency. A federal commitment of at least $200,000 was also announced by the Minister of Transport to support six sustainable transportation projects. The provincial Minister of the Environment announced the membership of the province's Anti-Smog Action Plan, which involves some 50 partners from industry associations, companies, government agencies and non-government organizations to help Ontario to meet its commitment to reduces nitrogen oxides and volatile organic compounds emissions by 45 per cent by 2015. A strategy for

  18. The Effectiveness of the Smog Index in Determining the Reading Levels of Business and Distributive Education Texts.

    Science.gov (United States)

    Schultheis, Robert A.; Anderson, Roberta

    1982-01-01

    McLaughlin's Smog Index was compared to the Dale-Chall formula for the determination of reading levels of 48 textbooks in business and distributive education. A Modified Smog Index proved a valid substitute for the Dale-Chall formula when used to evaluate the reading levels of business and distributive education narrative. (Author/CT)

  19. The Impact of the 2013 Eastern China Smog on Outpatient Visits for Coronary Heart Disease in Shanghai, China.

    Science.gov (United States)

    Huang, Fang; Chen, Renjie; Shen, Yuetian; Kan, Haidong; Kuang, Xingya

    2016-06-23

    There have been relatively few opportunities to examine the cardiovascular effects of an extreme air pollution event in China. We aimed to examine the impact of the 2013 Eastern China Smog occurring from 2 to 9 December 2013, on outpatient visits for coronary heart diseases (CHD) in a typical hospital in Shanghai, China. We used the over-dispersed, generalized additive model to estimate the relative risk (RR) of the 2013 Eastern China Smog on the outpatient visits by comparing the smog period (2-9 December 2013; 8 days) to the non-smog period (1 November-1 December 2013, and 10 December-28 February 2014; 112 days). This model also controlled for time trends, days of the week, holidays, and meteorological factors. A stratification analysis was performed to estimate sex- and age-specific RRs. The daily average PM2.5 (fine particulate matter with an aerodynamic diameter less than 2.5 μm) concentrations during the smog period were 212 μg/m³, which were three times higher than during the non-smog period (76 μg/m³). The smog in Eastern China in 2013 was significantly associated with an increased risk of outpatient visits for CHD. For example, the RR was 1.18 (95% CI: 1.04, 1.32) on lag 0 day. There were similar effects on males and females. Our analyses provided preliminary evidence that smog constituted a significant risk factor of CHD in China.

  20. The Impact of the 2013 Eastern China Smog on Outpatient Visits for Coronary Heart Disease in Shanghai, China

    Directory of Open Access Journals (Sweden)

    Fang Huang

    2016-06-01

    Full Text Available There have been relatively few opportunities to examine the cardiovascular effects of an extreme air pollution event in China. We aimed to examine the impact of the 2013 Eastern China Smog occurring from 2 to 9 December 2013, on outpatient visits for coronary heart diseases (CHD in a typical hospital in Shanghai, China. We used the over-dispersed, generalized additive model to estimate the relative risk (RR of the 2013 Eastern China Smog on the outpatient visits by comparing the smog period (2–9 December 2013; 8 days to the non-smog period (1 November–1 December 2013, and 10 December–28 February 2014; 112 days. This model also controlled for time trends, days of the week, holidays, and meteorological factors. A stratification analysis was performed to estimate sex- and age-specific RRs. The daily average PM2.5 (fine particulate matter with an aerodynamic diameter less than 2.5 μm concentrations during the smog period were 212 μg/m3, which were three times higher than during the non-smog period (76 μg/m3. The smog in Eastern China in 2013 was significantly associated with an increased risk of outpatient visits for CHD. For example, the RR was 1.18 (95% CI: 1.04, 1.32 on lag 0 day. There were similar effects on males and females. Our analyses provided preliminary evidence that smog constituted a significant risk factor of CHD in China.

  1. The little holographic bubble chambers

    International Nuclear Information System (INIS)

    Herve, A.

    1983-01-01

    The lifetime study of the charmed particles has readvanced the idea to use holography for the little fast-cycle bubble chambers. A pilot experiment has been realised in 1982 with a little bubble chamber filled up with freon-115. 40000 holograms have been recorded [fr

  2. Phytohormones in needles of spruce (Picea abies [L.] Karst.) under different levels of air pollution in the open-top chamber experiment at Edelmannshof

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, A.; Frenzel, B. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Botanik

    1997-12-01

    The plant hormones ethylene (ACC, MACC), abscisic acid and indoleacetic acid were investigated between August 1988 and December 1989 in current-year and one-year-old needles of the twelve spruce trees of the Edelmannshof experiment. Data from this period do not allow to reliably differentiate between consequences of the reduced impact of immissions (open-top chambers receiving charcoal-filtered air) and individual differences of the trees investigated. The conditions are discussed that might have made such a differentiation possible but which were not fulfilled at Edelmannshof. (orig.)

  3. Tests of the data acquisition system and detector control system for the muon chambers of the CMS experiment at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, Michael Christian

    2009-02-27

    The Phys. Inst. III A of RWTH Aachen University is involved in the development, production and tests of the Drift Tube (DT) muon chambers for the barrel muon system of the CMS detector at the LHC at CERN (Geneva). The present thesis describes some test procedures which were developed and performed for the chamber local Data Acquisition (DAQ) system, as well as for parts of the Detector Control System (DCS). The test results were analyzed and discussed. Two main kinds of DAQ tests were done. On the one hand, to compare two different DAQ systems, the chamber signals were split and read out by both systems. This method allowed to validate them by demonstrating, that there were no relevant differences in the measured drift times, generated by the same muon event in the same chamber cells. On the other hand, after the systems were validated, the quality of the data was checked. For this purpose extensive noise studies were performed. The noise dependence on various parameters (threshold,HV) was investigated quantitatively. Also detailed studies on single cells, qualified as ''dead'' and ''noisy'' were done. For the DAQ tests a flexible hardware and software environment was needed. The organization and installation of the supplied electronics, as well as the software development was realized within the scope of this thesis. The DCS tests were focused on the local gas pressure read-out components, attached directly to the chamber: pressure sensor, manifolds and the pressure ADC (PADC). At first it was crucial to proof, that the calibration of the mentioned chamber components for the gas pressure measurement is valid. The sensor calibration data were checked and possible differences in their response to the same pressure were studied. The analysis of the results indicated that the sensor output depends also on the ambient temperature, a new experience which implied an additional pedestal measurement of the chamber gas pressure

  4. submitter Phase transition observations and discrimination of small cloud particles by light polarization in expansion chamber experiments

    CERN Document Server

    Nichman, Leonid; Järvinen, Emma; Ignatius, Karoliina; Höppel, Niko Florian; Dias, Antonio; Heinritzi, Martin; Simon, Mario; Tröstl, Jasmin; Wagner, Andrea Christine; Wagner, Robert; Williamson, Christina; Yan, Chao; Connolly, Paul James; Dorsey, James Robert; Duplissy, Jonathan; Ehrhart, Sebastian; Frege, Carla; Gordon, Hamish; Hoyle, Christopher Robert; Kristensen, Thomas Bjerring; Steiner, Gerhard; McPherson Donahue, Neil; Flagan, Richard; Gallagher, Martin William; Kirkby, Jasper; Möhler, Ottmar; Saathoff, Harald; Schnaiter, Martin; Stratmann, Frank; Tomé, António

    2016-01-01

    Cloud microphysical processes involving the ice phase in tropospheric clouds are among the major uncertainties in cloud formation, weather, and general circulation models. The detection of aerosol particles, liquid droplets, and ice crystals, especially in the small cloud particle-size range below 50 μm, remains challenging in mixed phase, often unstable environments. The Cloud Aerosol Spectrometer with Polarization (CASPOL) is an airborne instrument that has the ability to detect such small cloud particles and measure the variability in polarization state of their backscattered light. Here we operate the versatile Cosmics Leaving OUtdoor Droplets (CLOUD) chamber facility at the European Organization for Nuclear Research (CERN) to produce controlled mixed phase and other clouds by adiabatic expansions in an ultraclean environment, and use the CASPOL to discriminate between different aerosols, water, and ice particles. In this paper, optical property measurements of mixed-phase clouds and viscous secondary ...

  5. Calculation of Wakefields and Higher Order Modes for the Vacuum Chamber of the ATLAS Experiment for the HL-LHC

    CERN Document Server

    Wanzenberg, R

    2013-01-01

    A design study for a High Luminosity Large Hadron Collider (HL-LHC) was started to extend the discovery potential of the Large Hadron Collider (LHC). The HL-LHC study implies also an upgraded configuration of the ATLAS detector with a new beam pipe. The trapped Higher Order Modes (HOMs) and the short range wakefields for the new design of the vacuum chamber are calculated using the computer codes MAFIA and ECHO2D. The short range wakefields are characterized in terms of kick and loss parameters. For the HOMs the frequency the R/Q and the Q-values are given which can directly converted into impedance data. The obtained data are intended to be included into the impedance database of the HL-LHC.

  6. Eight years of IMRT quality assurance with ionization chambers and film dosimetry: experience of the montpellier comprehensive cancer center

    Directory of Open Access Journals (Sweden)

    Dubois Jean-Bernard

    2011-07-01

    Full Text Available Abstract Background To present the results of quality assurance (QA in IMRT of film dosimetry and ionization chambers measurements with an eight year follow-up. Methods All treatment plans were validated under the linear accelerator by absolute and relative measures obtained with ionization chambers (IC and with XomatV and EDR2 films (Kodak. Results The average difference between IC measured and computed dose at isocenter with the gantry angle of 0° was 0.07 ± 1.22% (average ± 1 SD for 2316 prostate, 1.33 ± 3.22% for 808 head and neck (h&n, and 0.37 ± 0.62% for 108 measurements of prostate bed fields. Pelvic treatment showed differences of 0.49 ± 1.86% in 26 fields for prostate cases and 2.07 ± 2.83% in 109 fields of anal canal. Composite measurement at isocenter for each patient showed an average difference with computed dose of 0.05 ± 0.87% for 386 prostate, 1.49 ± 1.86% for 158 h&n, 0.37 ± 0.34% for 23 prostate bed, 0.80 ± 0.28% for 4 pelvis, and 2.31 ± 0.56% for 17 anal canal cases. On the first 250 h&n analyzed by film in absolute dose, the average of the points crossing a gamma index 3% and 3 mm was 93%. This value reached 99% for the prostate fields. Conclusion More than 3500 beams were found to be within the limits defined as validated for treatment between 2001 and 2008.

  7. SMOG 2: A Versatile Software Package for Generating Structure-Based Models.

    Science.gov (United States)

    Noel, Jeffrey K; Levi, Mariana; Raghunathan, Mohit; Lammert, Heiko; Hayes, Ryan L; Onuchic, José N; Whitford, Paul C

    2016-03-01

    Molecular dynamics simulations with coarse-grained or simplified Hamiltonians have proven to be an effective means of capturing the functionally important long-time and large-length scale motions of proteins and RNAs. Originally developed in the context of protein folding, structure-based models (SBMs) have since been extended to probe a diverse range of biomolecular processes, spanning from protein and RNA folding to functional transitions in molecular machines. The hallmark feature of a structure-based model is that part, or all, of the potential energy function is defined by a known structure. Within this general class of models, there exist many possible variations in resolution and energetic composition. SMOG 2 is a downloadable software package that reads user-designated structural information and user-defined energy definitions, in order to produce the files necessary to use SBMs with high performance molecular dynamics packages: GROMACS and NAMD. SMOG 2 is bundled with XML-formatted template files that define commonly used SBMs, and it can process template files that are altered according to the needs of each user. This computational infrastructure also allows for experimental or bioinformatics-derived restraints or novel structural features to be included, e.g. novel ligands, prosthetic groups and post-translational/transcriptional modifications. The code and user guide can be downloaded at http://smog-server.org/smog2.

  8. Development of SMOG-Cro readability formula for healthcare communication and patient education.

    Science.gov (United States)

    Brangan, Sanja

    2015-03-01

    Effective communication shows a positive impact on patient satisfaction, compliance and medical outcomes, at the same time reducing the healthcare costs. Written information for patients needs to correspond to health literacy levels of the intended audiences. Readability formulas correlate well with the reading and comprehension tests but are considered an easier and quicker method to estimate a text difficulty. SMOG readability formula designed for English language needs to be modified if used for texts in other languages. The aim of this study was to develop a readability formula based on SMOG, that could be used to estimate text difficulty of written materials for patients in Croatian language. Contras- tive analysis of English and Croatian language covering a corpus of almost 100,000 running words showed clear linguis- tic differences in the number of polysyllabic words. The new formula, named SMOG-Cro, is presented as an equation: SMOG-Cro = 2 + √4+ syllables, with the score showing the number of years of education a person needs to be able to understand a piece of writing. The presented methodology could help in the development of readability formulas for other languages. We hope the results of this study are soon put into practice for more effective healthcare communication and patient education, and for development of a health literacy assessment tool in Croatian language.

  9. SMOG 2: A Versatile Software Package for Generating Structure-Based Models.

    Directory of Open Access Journals (Sweden)

    Jeffrey K Noel

    2016-03-01

    Full Text Available Molecular dynamics simulations with coarse-grained or simplified Hamiltonians have proven to be an effective means of capturing the functionally important long-time and large-length scale motions of proteins and RNAs. Originally developed in the context of protein folding, structure-based models (SBMs have since been extended to probe a diverse range of biomolecular processes, spanning from protein and RNA folding to functional transitions in molecular machines. The hallmark feature of a structure-based model is that part, or all, of the potential energy function is defined by a known structure. Within this general class of models, there exist many possible variations in resolution and energetic composition. SMOG 2 is a downloadable software package that reads user-designated structural information and user-defined energy definitions, in order to produce the files necessary to use SBMs with high performance molecular dynamics packages: GROMACS and NAMD. SMOG 2 is bundled with XML-formatted template files that define commonly used SBMs, and it can process template files that are altered according to the needs of each user. This computational infrastructure also allows for experimental or bioinformatics-derived restraints or novel structural features to be included, e.g. novel ligands, prosthetic groups and post-translational/transcriptional modifications. The code and user guide can be downloaded at http://smog-server.org/smog2.

  10. Peltier-based cloud chamber

    Science.gov (United States)

    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.

  11. Pelletron general purpose scattering chamber

    International Nuclear Information System (INIS)

    Chatterjee, A.; Kailas, S.; Kerekette, S.S.; Navin, A.; Kumar, Suresh

    1993-01-01

    A medium sized stainless steel scattering chamber has been constructed for nuclear scattering and reaction experiments at the 14UD pelletron accelerator facility. It has been so designed that several types of detectors, varying from small sized silicon surface barrier detectors to medium sized gas detectors and NaI detectors can be conveniently positioned inside the chamber for detection of charged particles. The chamber has been planned to perform the following types of experiments : angular distributions of elastically scattered particles, fission fragments and other charged particles, angular correlations for charged particles e.g. protons, alphas and fission fragments. (author). 2 figs

  12. Dormancy release of Norway spruce under climatic warming: testing ecophysiological models of bud burst with a whole-tree chamber experiment.

    Science.gov (United States)

    Hänninen, Heikki; Slaney, Michelle; Linder, Sune

    2007-02-01

    Ecophysiological models predicting timing of bud burst were tested with data gathered from 40-year-old Norway spruce (Picea abies (L.) Karst.) trees growing in northern Sweden in whole-tree chambers under climatic conditions predicted to prevail in 2100. Norway spruce trees, with heights between 5 and 7 m, were enclosed in individual chambers that provided a factorial combination of ambient (365 micromol mol-1) or elevated (700 micromol mol-1) atmospheric CO2 concentration, [CO2], and ambient or elevated air temperature. Temperature elevation above ambient ranged from +2.8 degrees C in summer to +5.6 degrees C in winter. Compared with control trees, elevated air temperature hastened bud burst by 2 to 3 weeks, whereas elevated [CO2] had no effect on the timing of bud burst. A simple model based on the assumption that bud rest completion takes place on a fixed calendar day predicted timing of bud burst more accurately than two more complicated models in which bud rest completion is caused by accumulated chilling. Together with some recent studies, the results suggest that, in adult trees, some additional environmental cues besides chilling are required for bud rest completion. Although it appears that these additional factors will protect trees under predicted climatic warming conditions, increased risk of frost damage associated with earlier bud burst cannot be ruled out. Inconsistent and partially anomalous results obtained in the model fitting show that, in addition to phenological data gathered under field conditions, more specific data from growth chamber and greenhouse experiments are needed for further development and testing of the models.

  13. Studies of ageing effects of Small-Strip Thin Gap Chambers for the Muon Spectrometer Upgrade of the ATLAS Experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00425540; The ATLAS collaboration

    2016-01-01

    The instantaneous luminosity of the Large Hadron Collider at CERN will be increased by up to seven times its design value by undergoing an extensive upgrade program over the coming decade. The largest upgrade project for the ATLAS Muon System is the replacement of the present first station in the forward regions with the so-called New Small Wheels (NSWs), to be installed during the LHC long shutdown in 2019-2020. Small-Strip Thin Gap Chambers (sTGC) detectors are one chosen technology to provide fast trigger and high precision muon tracking under the high luminosity LHC conditions. The basic sTGC structure consists of a grid of gold-plated tungsten wires sandwiched between two resistive cathode planes at a small distance from the wire plane. We study ageing effects of sTGC detectors with a gas mixture of 55\\% of CO$_{2}$ and 45\\% of n-pentane. A sTGC detector was irradiated with beta-rays from a 10~mCi~$^{90}$Sr source. Three different gas flow rates were tested. We observed no deterioration on pulse height o...

  14. Studies of ageing effects of Small-Strip Thin Gap Chambers for the Muon Spectrometer Upgrade of the ATLAS Experiment

    CERN Document Server

    Gignac, Matthew; The ATLAS collaboration

    2016-01-01

    The instantaneous luminosity of the Large Hadron Collider at CERN will be increased up to a factor of five with respect to the design value by undergoing an extensive upgrade program over the coming decade. The largest upgrade project for the ATLAS Muon System is the replacement of the present first station in the forward regions with the so-called New Small Wheels (NSWs), to be installed during the LHC long shutdown in 2019/20. Small-Strip Thin Gap Chambers (sTGC) detectors are one chosen technology to provide fast trigger and high precision muon tracking under the high luminosity LHC conditions. The basic sTGC structure consists of a grid of gold-plated tungsten wires sandwiched between two resistive cathode planes at a small distance from the wire plane. We study ageing effects of sTGC detectors with a gas mixture of 55% of CO_2 and 45% of n-pentane. A sTGC detector was irradiated with beta-rays from a Sr-90 source. Three different gas flow rates were tested. We observed no deterioration on pulse height of...

  15. Experience Gained from Construction of Low-Emission Combustion Chambers for On-Land Large-Capacity Gas-Turbine Units: GT24/26

    Science.gov (United States)

    Bulysova, L. A.; Vasil'ev, V. D.; Berne, A. L.; Gutnik, M. M.

    2018-06-01

    This article is the third in a planned series of articles devoted to the experience gained around the world in constructing low-emission combustion chambers for on-land large-capacity (above 250 MW) gas-turbine units (GTUs). The aim of this study is to generalize and analyze the ways in which different designers apply the fuel flow and combustion arrangement principles and the fuel feed control methods. The considered here GT24 and GT26 (GT24/26) gas-turbine units generating electric power at the 60 and 50 Hz frequencies, respectively, are fitted with burners of identical designs. Designed by ABB, these GTUs were previously manufactured by Alstom, and now they are produced by Ansaldo Energia. The efficiency of these GTUs reaches 41% at the 354 MW power output during operation in the simple cycle and 60.5% at the 505MW power output during operation in the combined cycle. Both GTUs comply with all requirements for harmful emissions. The compression ratio is equal to 35. In this article, a system is considered for two-stage fuel combustion in two sequentially arranged low-emission combustion chambers, one of which is placed upstream of the high-pressure turbine (CC1) and the other upstream of the low-pressure turbine (CC2). The article places the main focus on the CC2, which operates with a decreased content of oxygen in the oxidizer supplied to the burner inlets. The original designs of vortex generators and nozzles placed in the flow of hot combustion products going out from the high-pressure turbine are described in detail. The article also presents an original CC2 front plate cooling system, due to which a significantly smaller amount of air fed for cooling has been reached. The article also presents the pressure damping devices incorporated in the chamber, the use of which made it possible to obtain a significantly wider range of CC loads at which its low-emission operation is ensured. The fuel feed adjustment principles and the combustion control methods

  16. Wire chamber degradation at the Argonne ZGS

    International Nuclear Information System (INIS)

    Haberichter, W.; Spinka, H.

    1986-01-01

    Experience with multiwire proportional chambers at high rates at the Argonne Zero Gradient Synchrotron is described. A buildup of silicon on the sense wires was observed where the beam passed through the chamber. Analysis of the chamber gas indicated that the density of silicon was probably less than 10 ppM

  17. Simple Cloud Chambers Using Gel Ice Packs

    Science.gov (United States)

    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…

  18. Program and performance characteristics of the environmental chambers during a long-term experiment with Norway spruce trees exposed to ozone, acid mist, and frost

    Energy Technology Data Exchange (ETDEWEB)

    Payer, H D; Blank, L W; Eisenmann, T; Runkel, K H; Bosch, C

    1986-09-01

    This paper describes the climatic and pollutant conditions simulated in the new environmental chambers of the GSF (Payer et al. 1986) during the course of the first (five-month) experiment. This so-called 'pilot-project' was also used to assess the technical performance of this new research facility during realistic experimental conditions. The factorial design with 16 groups analyzed the effects of i) normal winter temperatures vs. an episode of severe frost, ii) low vs. raised ozone concentrations, iii) misting with water of pH 5.6 vs. water of pH 3.0, and iiii) fertilized vs. unfertilized soil. The climatic conditions and ozone levels applied were based on longterm field measurements from the higher regions of the Bavarian forest in order to simulate realistic diurnal and seasonal variations as observed at a site affected by severe forest decline. The main characteristics of this exposure program are outlined, and an assessment of the technical performance of the environmental chambers is given in this paper.

  19. Studies on multigap resistive plate chamber prototypes for the new NeuLAND detector at the R3B experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Elvers, Michael; Endres, Janis; Zilges, Andreas [IKP, Universitaet Koeln (Germany); Aumann, Tom; Boretzky, Konstanze; Hehner, Joerg; Heil, Michael; Prokopowicz, Wawrczek; Reifarth, Rene; Schrieder, Gerhard [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Bemmerer, Daniel; Stach, Daniel; Wagner, Andreas; Yakorev, Dmitry [Forschungszentrum Dresden-Rossendorf (FZD), Dresden (Germany); Kratz, Jens Volker; Rossi, Dominic [Johannes-Gutenberg-Universitaet, Mainz (Germany)

    2009-07-01

    The NeuLAND detector is part of the R3B experiment at FAIR and will detect neutrons between 0.2 and 1 GeV. The high energy neutrons are converted to charged particles, mainly protons, which are detected by Multigap Resistive Plate Chambers (MRPC). For the detector, a time resolution of {sigma}{sub t} < 100 ps and a position resolution of {sigma}{sub x,y,z} {approx}1 cm is required for given flight paths in the range from 10 to 35 m. An active area of 2 x 2 m{sup 2} of the neutron detector at a distance of 12.5 m to the target will match the angular acceptance of {+-}80 mrad for the neutrons defined by the gap of the superconducting dipole magnet. The salient features of the prototypes are described, as well as electrical measurements and studies with cosmic rays.

  20. Development of a highly selective muon trigger exploiting the high spatial resolution of monitored drift-tube chambers for the ATLAS experiment at the HL-LHC

    CERN Document Server

    Kortner, Oliver; The ATLAS collaboration

    2018-01-01

    The High-Luminosity LHC will provide the unique opportunity to explore the nature of physics beyond the Standard Model. Highly selective first level triggers are essential for the physics programme of the ATLAS experiment at the HL-LHC, where the instantaneous luminosity will exceed the LHC design instantaneous luminosity by almost an order of magnitude. The ATLAS first level muon trigger rate is dominated by low momentum muons, selected due to the moderate momentum resolution of the current system. This first level trigger limitation can be overcome by including data from the precision muon drift tube (MDT) chambers. This requires the fast continuous transfer of the MDT hits to the off-detector trigger logic and a fast track reconstruction algorithm performed in the trigger logic. The feasibility of this approach was studied with LHC collision data and simulated data. Two main options for the hardware implementation will be studied with demonstrators: an FPGA based option with an embedded ARM microprocessor ...

  1. Development of a Highly Selective Muon Trigger Exploiting the High Spatial Resolution of Monitored Drift-Tube Chambers for the ATLAS Experiment at the HL-LHC

    CERN Document Server

    Kortner, Oliver; The ATLAS collaboration

    2018-01-01

    The High-Luminosity LHC will provide the unique opportunity to explore the nature of physics beyond the Standard Model. Highly selective first level triggers are essential for the physics programme of the ATLAS experiment at the HL-LHC, where the instantaneous luminosity will exceed the LHC design instantaneous luminosity by almost an order of magnitude. The ATLAS first level muon trigger rate is dominated by low momentum muons, selected due to the moderate momentum resolution of the current system. This first level trigger limitation can be overcome by including data from the precision muon drift tube (MDT) chambers. This requires the fast continuous transfer of the MDT hits to the off-detector trigger logic and a fast track reconstruction algorithm performed in the trigger logic. The feasibility of this approach was studied with LHC collision data and simulated data. Two main options for the hardware implementation are currently studied with demonstrators, an FPGA based option with an embedded ARM microproc...

  2. CO2 dose–response functions for wheat grain, protein and mineral yield based on FACE and open-top chamber experiments

    International Nuclear Information System (INIS)

    Pleijel, Håkan; Högy, Petra

    2015-01-01

    Data from three Swedish open-top chamber and four German FACE experiments were combined to derive response functions for elevated CO 2 (eCO 2 ) effects on Cd, Zn, Mn, protein, grain yield, grain mass and grain number of wheat. Grain yield and grain number were increased by ∼6% and ∼7%, respectively, per 100 ppm CO 2 ; the former effect was linked to plant nitrogen status. Grain mass was not influenced by eCO 2 , whereas Cd concentration was reduced. Unlike Zn, Mn and protein, effects on Cd yield were not related to effects on grain yield. Yields of Mn, Zn and (weakly) protein were positively affected by eCO 2 . For protein, grain yield, grain mass and grain number, the results were consistent among the FACE and OTC experiments. A key conclusion was that yields of essential nutrients were enhanced (Mn > Zn > protein), although less than grain yield, which would not be expected from a simple dilution model. - Highlights: • Grain yield and grain number were positively affected by 6–7% per 100 ppm CO 2 . • Yield stimulation by CO 2 was influenced by plant nitrogen status. • Cd concentration was reduced by elevated CO 2 . • Yields of Zn, Mn and protein were stimulated by CO 2 , but less than grain yield. • A simple dilution model did not explain effects on Zn, Mn and protein. - Yields of Zn, Mn and protein were stimulated less by elevated CO 2 than grain yield, while Cd yield and grain mass were unaffected, in wheat exposed in FACE and open-top chambers

  3. Evaluation of 1,3,5 trimethylbenzene degradation in the detailed tropospheric chemistry mechanism, MCMv3.1, using environmental chamber data

    Directory of Open Access Journals (Sweden)

    A. Metzger

    2008-11-01

    Full Text Available The degradation mechanism of 1,3,5-trimethyl- benzene (TMB as implemented in the Master Chemical Mechanism version 3.1 (MCM was evaluated using data from the environmental chamber at the Paul Scherrer Institute. The results show that the MCM provides a consistent description of the photo-oxidation of TMB/NOx mixtures for a range of conditions. In all cases the agreement between the measurement and the simulation decreases with decreasing VOC-NOx ratio and in addition with increasing precursor concentration. A significant underestimation of the decay rate of TMB and thus underestimation of reactivity in the system, consistent with results from previous appraisals of the MCM, was observed.

    Much higher nitrous acid (HONO concentrations compared to simulations and expected from chamber characterization experiments were measured during these smog chamber experiments. A light induced NO2 to HONO conversion at the chamber walls is suggested to occur. This photo-enhanced NO2 to HONO conversion with subsequent HONO photolysis enhances the reactivity of the system. After the implementation of this reaction in the model it describes the decay of TMB properly. Nevertheless, the model still over-predicts ozone at a later stage of the experiment. This can be attributed to a too slow removal of NO2. It is also shown that this photo-enhanced HONO formation is not restricted to TMB photo-oxidation but also occurs in other chemical systems (e.g. α-pinene. However, the influence of HONO as a source of OH radicals is less important in these more reactive systems and therefore the importance of the HONO chemistry is less obvious.

  4. Space plasma simulation chamber

    International Nuclear Information System (INIS)

    1986-01-01

    Scientific results of experiments and tests of instruments performed with the Space Plasma Simulation Chamber and its facility are reviewed in the following six categories. 1. Tests of instruments on board rockets, satellites and balloons. 2. Plasma wave experiments. 3. Measurements of plasma particles. 4. Optical measurements. 5. Plasma production. 6. Space plasms simulations. This facility has been managed under Laboratory Space Plasma Comittee since 1969 and used by scientists in cooperative programs with universities and institutes all over country. A list of publications is attached. (author)

  5. Early-Life Persistent Vitamin D Deficiency Alters Cardiopulmonary Responses to Particulate Matter-Enhanced Atmospheric Smog in Adult Mice

    Science.gov (United States)

    This study demonstrates that early-life persistent vitamin D deficiency alters the cardiopulmonary response to smog in mice and may increase risk of adverse effects. Early life nutritional deficiencies can lead to increased cardiovascular susceptibility to environme...

  6. Multiwire proportional chamber development

    Science.gov (United States)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  7. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  8. The OPAL vertex drift chamber

    International Nuclear Information System (INIS)

    Carter, J.R.; Elcombe, P.A.; Hill, J.C.; Roach, C.M.; Armitage, J.C.; Carnegie, R.K.; Estabrooks, P.; Hemingway, R.; Karlen, D.; McPherson, A.; Pinfold, J.; Roney, J.M.; Routenburg, P.; Waterhouse, J.; Hargrove, C.K.; Klem, D.; Oakham, F.G.; Carter, A.A.; Jones, R.W.L.; Lasota, M.M.B.; Lloyd, S.L.; Pritchard, T.W.; Wyatt, T.R.

    1990-01-01

    A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar. (orig.)

  9. Protective effects of edaravone combined puerarin on inhalation lung injury induced by black gunpowder smog.

    Science.gov (United States)

    Wang, Zhengguan; Li, Ruibing; Liu, Yifan; Liu, Xiaoting; Chen, Wenyan; Xu, Shumin; Guo, Yuni; Duan, Jinyang; Chen, Yihong; Wang, Chengbin

    2015-05-01

    The present study aimed to investigate the combined effects of puerarin with edaravone on inhalation lung injury induced by black gunpowder smog. Male Wistar rats were divided into five groups (control group, edaravone group, puerarin group, edaravone combined with puerarin group and inhalation group). The severity of pulmonary injuries was evaluated after inducing acute lung injury. Arterial blood gas, inflammatory cytokines, biochemical, parameters, cell counting, W/D weight ratio and histopathology were analyzed. Results in lung tissues, either edaravone or puerarin treatment alone showed significant protective effects against neutrophil infiltration and tissue injury, as demonstrated by myeloperoxidase activity and histopathological analysis (all pedaravone and puerarin demonstrated additive protective effects on smog-induced lung injury, compared with single treatment. Combination of edaravone and puerarin shows promise as a new treatment option for acute lung injury/acute respiratory distress syndrome patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Effect of latitude on the potential for formation of photochemical smog

    Energy Technology Data Exchange (ETDEWEB)

    Neiboer, H [Central Laboratorium TNO, Delft, Netherlands; Carter, W P.L.; Lloyd, A C; Pitts, Jr, J N

    1976-01-01

    The effect of latitude on the potential for the formation of photochemical smog has been assessed. Calculations suggest that at the summer solstice, the integrated sunlight intensity at Rotterdam or Fairbanks (Alaska) is very similar to that in Los Angeles. Computations carried out, assuming the same pollutant emission inventory for the three locations, showed that ozone and PAN dosages depend more on the integrated light intensity than on the nature of the light intensity distribution with time. Therefore, if factors such as emissions and meteorological conditions are equal, the potential for significant photochemical smog formation during the summer months is similar for Los Angeles (34/sup 0/N) and northern cities such as Rotterdam (52/sup 0/N) and Nome or Fairbanks, Alaska (65/sup 0/N).

  11. Electro-smog; Elektrosmog. Ein Thema in aller Munde, doch viele Quellen sind wenig bekannt

    Energy Technology Data Exchange (ETDEWEB)

    Thalmann, K. [Ecosens AG, Wallisellen (Switzerland); Gugler, M. [Schaffner EMV AG, Luterbach (Switzerland)

    2007-07-01

    This article deals with the topic of electro-smog - the non-ionising radiation produced by technical installations in low and high-frequency ranges. Various sources such as mobile telephones, radio and television and newer sources such as WLAN and Bluetooth are discussed. The correct installation of electrical circuits in buildings is considered as being a simple and effective means of reducing mains-frequency electro-smog. Effects on human beings are discussed and regulations concerning protection against non-ionising radiation are examined. The fact that certain electrical and magnetic fields such as those caused by cookers, vacuum cleaners and hair-dryers are short term, whereas radio-alarms, laptops and charging stations are quasi-continuous sources. Also the placing of boilers and refrigerators is considered. The specific absorption rate (SAR) value for mobile telephones is also looked at and recommendations are made on keeping distance to electro-magnetic sources.

  12. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  13. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1980-01-01

    A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

  14. Applications of the three-dimensional air quality system to western U.S. air quality: IDEA, smog blog, smog stories, airquest, and the remote sensing information gateway.

    Science.gov (United States)

    Hoff, Raymond; Zhang, Hai; Jordan, Nikisa; Prados, Ana; Engel-Cox, Jill; Huff, Amy; Weber, Stephanie; Zell, Erica; Kondragunta, Shobha; Szykman, James; Johns, Brad; Dimmick, Fred; Wimmers, Anthony; Al-Saadi, Jay; Kittaka, Chieko

    2009-08-01

    A system has been developed to combine remote sensing and ground-based measurements of aerosol concentration and aerosol light scattering parameters into a three-dimensional view of the atmosphere over the United States. Utilizing passive and active remote sensors from space and the ground, the system provides tools to visualize particulate air pollution in near real time and archive the results for retrospective analyses. The main components of the system (Infusing satellite Data into Environmental Applications [IDEA], the U.S. Air Quality Weblog [Smog Blog], Smog Stories, U.S. Environmental Protection Agency's AIRQuest decision support system, and the Remote Sensing Information Gateway [RSIG]) are described, and the relationship of how data move from one system to another is outlined. To provide examples of how the results can be used to analyze specific pollution episodes, three events (two fires and one wintertime low planetary boundary layer haze) are discussed. Not all tools are useful at all times, and the limitations, including the sparsity of some data, the interference caused by overlying clouds, etc., are shown. Nevertheless, multiple sources of data help a state, local, or regional air quality analyst construct a more thorough picture of a daily air pollution situation than what one would obtain with only surface-based sensors.

  15. Potential oxidative stress in the bodies of electric arc welding operators: effect of photochemical smog.

    Science.gov (United States)

    Zhu, You-Gen; Zhou, Jun-Fu; Shan, Wei-Ying; Zhou, Pei-Su; Tong, Gui-Zhong

    2004-12-01

    To investigate whether photochemical smog emitted during the process of electric arc welding might cause oxidative stress and potential oxidative damage in the bodies of welding operators. Seventy electric arc welding operators (WOs) and 70 healthy volunteers (HVs) were enrolled in a randomized controlled study design, in which the levels of vitamin C (VC) and vitamin E (VE) in plasma as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and the level of lipoperoxide (LPO) in erythrocytes were determined by spectrophotometry. Compared with the average values of the above experimental parameters in the HVs group, the average values of VC and VE in plasma as well as those of SOD, CAT and GPX in erythrocytes in the WOs group were significantly decreased (P smog the values of VC, VE, SOD, and GPX, except for CAT, in the WOs were decreased gradually (P smog in the bodies of WOs, thereby causing potential oxidative and lipoperoxidative damages in their bodies.

  16. SMOG@ctbp: simplified deployment of structure-based models in GROMACS.

    Science.gov (United States)

    Noel, Jeffrey K; Whitford, Paul C; Sanbonmatsu, Karissa Y; Onuchic, José N

    2010-07-01

    Molecular dynamics simulations with coarse-grained and/or simplified Hamiltonians are an effective means of capturing the functionally important long-time and large-length scale motions of proteins and RNAs. Structure-based Hamiltonians, simplified models developed from the energy landscape theory of protein folding, have become a standard tool for investigating biomolecular dynamics. SMOG@ctbp is an effort to simplify the use of structure-based models. The purpose of the web server is two fold. First, the web tool simplifies the process of implementing a well-characterized structure-based model on a state-of-the-art, open source, molecular dynamics package, GROMACS. Second, the tutorial-like format helps speed the learning curve of those unfamiliar with molecular dynamics. A web tool user is able to upload any multi-chain biomolecular system consisting of standard RNA, DNA and amino acids in PDB format and receive as output all files necessary to implement the model in GROMACS. Both C(alpha) and all-atom versions of the model are available. SMOG@ctbp resides at http://smog.ucsd.edu.

  17. Particle number concentration, size distribution and chemical composition during haze and photochemical smog episodes in Shanghai.

    Science.gov (United States)

    Wang, Xuemei; Chen, Jianmin; Cheng, Tiantao; Zhang, Renyi; Wang, Xinming

    2014-09-01

    The aerosol number concentration and size distribution as well as size-resolved particle chemical composition were measured during haze and photochemical smog episodes in Shanghai in 2009. The number of haze days accounted for 43%, of which 30% was severe (visibilitysmog episodes, about 5.89 times and 4.29 times those of clean days. The particle volume concentration and surface concentration in haze, photochemical smog and clean days were 102, 49, 15μm(3)/cm(3) and 949, 649, 206μm(2)/cm(3), respectively. As haze events got more severe, the number concentration of particles smaller than 50nm decreased, but the particles of 50-200nm and 0.5-1μm increased. The diurnal variation of particle number concentration showed a bimodal pattern in haze days. All soluble ions were increased during haze events, of which NH4(+), SO4(2-) and NO3(-) increased greatly, followed by Na(+), K(+), Ca(2+) and Cl(-). These ions were very different in size-resolved particles during haze and photochemical smog episodes. Copyright © 2014. Published by Elsevier B.V.

  18. Multiple production around 1000 TeV observed in the emulsion chamber experiments at Mt. Fuji and linkage experiments with air shower

    International Nuclear Information System (INIS)

    Torii, Syoji

    1980-01-01

    The multiple production around 1000 TeV is discussed in this paper by using the experimental data at Mt. Fuji and the results of the Monte Carlo simulation. Six events with the total energy more than 1000 TeV were observed in the emulsion chamber (EC) exposed for 600 m 2 year at Mt. Fuji. Various Monte Carlo calculations with the scaling model were performed. The relation between the transverse momentum and The Feynman scaling law is discussed. The frequency of the total gamma energy spectrum and the lateral distribution of the family were compared with the calculation. In the case that protons are dominant in primary cosmic ray, the multiplicity in the interaction increased according to 1/4 th power of energy. In the case of heavy nuclei, the experimental results can be reproduced by assuming the increase of cross-section, when the scaling holds. It is still hard to make definite conclusion on the break of scaling. Simultaneous observation of air family and air shower is proposed. (Kato, T.)

  19. Causes of variation among rice models in yield response to CO2 examined with Free-Air CO2 Enrichment and growth chamber experiments.

    Science.gov (United States)

    Hasegawa, Toshihiro; Li, Tao; Yin, Xinyou; Zhu, Yan; Boote, Kenneth; Baker, Jeffrey; Bregaglio, Simone; Buis, Samuel; Confalonieri, Roberto; Fugice, Job; Fumoto, Tamon; Gaydon, Donald; Kumar, Soora Naresh; Lafarge, Tanguy; Marcaida Iii, Manuel; Masutomi, Yuji; Nakagawa, Hiroshi; Oriol, Philippe; Ruget, Françoise; Singh, Upendra; Tang, Liang; Tao, Fulu; Wakatsuki, Hitomi; Wallach, Daniel; Wang, Yulong; Wilson, Lloyd Ted; Yang, Lianxin; Yang, Yubin; Yoshida, Hiroe; Zhang, Zhao; Zhu, Jianguo

    2017-11-01

    The CO 2 fertilization effect is a major source of uncertainty in crop models for future yield forecasts, but coordinated efforts to determine the mechanisms of this uncertainty have been lacking. Here, we studied causes of uncertainty among 16 crop models in predicting rice yield in response to elevated [CO 2 ] (E-[CO 2 ]) by comparison to free-air CO 2 enrichment (FACE) and chamber experiments. The model ensemble reproduced the experimental results well. However, yield prediction in response to E-[CO 2 ] varied significantly among the rice models. The variation was not random: models that overestimated at one experiment simulated greater yield enhancements at the others. The variation was not associated with model structure or magnitude of photosynthetic response to E-[CO 2 ] but was significantly associated with the predictions of leaf area. This suggests that modelled secondary effects of E-[CO 2 ] on morphological development, primarily leaf area, are the sources of model uncertainty. Rice morphological development is conservative to carbon acquisition. Uncertainty will be reduced by incorporating this conservative nature of the morphological response to E-[CO 2 ] into the models. Nitrogen levels, particularly under limited situations, make the prediction more uncertain. Improving models to account for [CO 2 ] × N interactions is necessary to better evaluate management practices under climate change.

  20. New Particle Formation in an Urban Atmosphere: The Role of Various Ingredients Investigated in the CLOUD Chamber

    Science.gov (United States)

    Baltensperger, U.; Xiao, M.; Hoyle, C.; Dada, L.; Garmash, O.; Stolzenburg, D.; Molteni, U.; Lehtipalo, K.; El-Haddad, I.; Dommen, J.

    2017-12-01

    Atmospheric aerosols play an important role on climate via aerosol-radiation interaction and aerosol-cloud interaction. The latter is strongly influenced by new particle formation (NPF). The physical and chemical mechanisms behind the NPF process are still under investigation. Great advancements were made in resolving chemical and physical mechanisms of NPF with a series of experiments conducted at the CLOUD (Cosmics Leaving Outdoor Droplets) chamber facility at CERN (Geneva, Switzerland), including binary nucleation of sulfuric acid - water, ternary nucleation of sulfuric acid - water with ammonia or dimethylamine as well as oxidation products (highly oxygenated molecules, HOMs) from biogenic precursors with and without the presence of sulfuric acid. Here, we investigate possible NPF mechanisms in urban atmospheres, where large populations are exposed to high aerosol concentrations; these mechanisms are still missing and are urgently needed. Urban atmospheres are highly polluted with high concentrations of SO2, ammonia, NOx and volatile organic vapors from anthropogenic activity as well as with high particle concentrations, which provide a high condensation sink for condensable gases. Aromatic hydrocarbons from industrial activities, traffic and residential combustion are present at high concentrations and contribute significantly to photochemical smog in the urban environment.The experiments were conducted at the CLOUD chamber facility during the CLOUD11 campaign in fall 2016. Three aromatic hydrocarbons were selected: toluene, 1,2,4-trimethylbenzene (1,2,4-TMB) and naphthalene (NPT). Experiments were also conducted with mixtures of the three aromatic hydrocarbons to better represent the urban atmosphere. All the experiments were conducted in the presence of sulfuric acid concentrations with or without the addition of ammonia and NOx. New particle formation rates and early growth rates derived for each precursor and their mixture, together with sulfuric acid and

  1. Holography in small bubble chambers

    International Nuclear Information System (INIS)

    Lecoq, P.

    1984-01-01

    This chapter reports on an experiment to determine the total charm cross section at different incident momenta using the small, heavy liquid bubble chamber HOBC. Holography in liquid hydrogen is also tested using the holographic lexan bubble chamber HOLEBC with the aim of preparing a future holographic experiment in hydrogen. The high intensity tests show that more than 100 incident tracks per hologram do not cause a dramatic effect on the picture quality. Hydrogen is more favorable than freon as the bubble growth is much slower in hydrogen. An advantage of holography is to have the maximum resolution in the full volume of the bubble chamber, which allows a gain in sensitivity by a factor of 10 compared to classical optics as 100 tracks per hologram look reasonable. Holograms are not more difficult to analyze than classical optics high-resolution pictures. The results show that holography is a very powerful technique which can be used in very high resolution particle physics experiments

  2. Study of dimuon spectrometer tracking chambers of the ALICE experiment at LHC; Etude des chambres de trajectoire du spectrometre dimuons de l'experience ALICE aupres du LHC

    Energy Technology Data Exchange (ETDEWEB)

    Kharmandarian, Liliane [Institut de Physique Nucleaire, CNRS - IN2P3, Universite Paris - Sud, 91406 Orsay Cedex (France)

    1999-12-16

    The ALICE (A Large Ion Collider Experiment) experiment will study ultrarelativistic heavy ion collisions at the Large Hadron Collider (LHC) in CERN as of 2005. An extensive R and D programme has been carried out on the dimuon spectrometer tracking chambers at the Nuclear Physics Institute in Orsay. Three multiwire proportional chamber prototypes with segmented cathodes, including a full-scale 1 m{sup 2} version, were constructed. In this thesis, the experimental tests are presented along with the simulations used to understand and optimize the detectors' performances. The prototypes were tested several times at the PS and SPS accelerators. The aims were to validate the choices made in terms of mechanical construction, geometrical parameters, gas mixture and read-out electronics. Analysis of the large amount of data collected has shown that the performances of this type of detector fulfill the required specifications. The results concerning the detectors' characteristics, spatial resolution efficiency, gain and homogeneity are given. Spatial resolutions of less than thirty microns were obtained. In parallel with the in-beam tests, several simulations have been developed in order to gain a better understanding of the detectors' response. They allowed, in particular, to define the segmentation of the cathode plane, to study the position reconstruction algorithm and to establish the future electronics specifications. (author)

  3. The Mark III vertex chamber and prototype test results

    International Nuclear Information System (INIS)

    Grab, C.

    1987-07-01

    A vertex chamber has been constructed for use in the Mark III experiment. The chamber is positioned inside the current main drift chamber and will be used to trigger data collection, to aid in vertex reconstruction, and to improve the momentum resolution. This paper discusses the chamber's construction and performance and tests of the prototype

  4. Washout ratio of NaCl particles by raindrops, snowflakes and fog particles obtained using the large artificial climate experiment chamber at ACEF in IES

    International Nuclear Information System (INIS)

    Kawabata, Hitoshi; Kondo, Kunio; Hasegawa, Hidenao; Akata, Naofumi; Chikuchi, Yuki; Hisamatsu, Shun'ichi; Inaba, Jiro; Komagata, Yuuetsu

    2007-01-01

    Scavenging of NaCl particles by rainfall, snowfall and fog was examined in a large artificial climate experiment chamber in which the meteorological elements were controlled. The scavenging coefficient of Na by rainfall and snowfall were obtained using Na concentrations in air and precipitation. The washout ratio of Na by fog was also measured using Na concentrations in air and fog water. The scavenging coefficients by snowfall were found to be larger than those by rainfall, and showed that the removal efficiency of the former was higher than that of the latter. The coefficients by both rainfall and snowfall increased linearly with precipitation intensity. When the average diameters of fog droplets were the same, the washout ratio of Na by fog increased with fog liquid water content. On the other hand, when liquid water contents were the same, the washout ratio decreased with increasing average diameter of fog droplets. The washout ratio of Na by fog exponentially increased with the total surface area of fog droplets. (author)

  5. Glove box chamber

    International Nuclear Information System (INIS)

    Cox, M.E.; Cox, M.E.

    1975-01-01

    An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

  6. Advances on fission chamber modelling

    International Nuclear Information System (INIS)

    Filliatre, Philippe; Jammes, Christian; Geslot, Benoit; Veenhof, Rob

    2013-06-01

    In-vessel, online neutron flux measurements are routinely performed in mock-up and material testing reactors by fission chambers. Those measurements have a wide range of applications, including characterization of experimental conditions, reactor monitoring and safety. Depending on the application, detectors may experience a wide range of constraints, of several magnitudes, in term of neutron flux, gamma-ray flux, temperature. Hence, designing a specific fission chamber and measuring chain for a given application is a demanding task. It can be achieved by a combination of experimental feedback and simulating tools, the latter being based on a comprehensive understanding of the underlying physics. A computation route that simulates fission chambers, named CHESTER, is presented. The retrieved quantities of interest are the neutron-induced charge spectrum, the electronic and ionic pulses, the mean current and variance, the power spectrum. It relies on the GARFIELD suite, originally developed for drift chambers, and makes use of the MAGBOLTZ code to assess the drift parameters of electrons within the filling gas, and the SRIM code to evaluate the stopping range of fission products. The effect of the gamma flux is also estimated. Computations made with several fission chambers exemplify the possibilities of the route. A good qualitative agreement is obtained when comparing the results with the experimental data available to date. In a near future, a comprehensive experimental programme will be undertaken to qualify the route using the known neutron sources, mock-up reactors and wide choice of fission chambers, with a stress on the predictiveness of the Campbelling mode. Depending on the results, a refinement of the modelling and an effort on the accuracy of input data are also to be considered. CHESTER will then make it possible to predict the overall sensitivity of a chamber, and to optimize the design for a given application. Another benefit will be to increase the

  7. Effects of seasonal smog on asthma and COPD exacerbations requiring emergency visits in Chiang Mai, Thailand.

    Science.gov (United States)

    Pothirat, Chaicharn; Tosukhowong, Apiwat; Chaiwong, Warawut; Liwsrisakun, Chalerm; Inchai, Juthamas

    2016-12-01

    Seasonal smog produces particulate matters that are less than 10 microns in diameter (PM₁₀), which are known to have several impacts on the respiratory system. This study was to determine the association of an increased PM10 level due to seasonal smog in Chiang Mai and emergency visits for asthma and chronic obstructive pulmonary disease (COPD) exacerbations. A retrospective cross-sectional study was conducted between the months of January and March from 2006 until 2009. The association of an increased PM₁₀ level and the daily number of asthma and COPD exacerbations were analyzed using a generalized linear model; a Poisson regression model was fit to the number of daily emergency visits using predictor variables: lags of PM10, day of the week, and time. There were a total of 917 emergency visits for acute exacerbations of asthma and COPD, with a median of 2 visits per day (range 0-10). The median PM₁₀ level during the same interval was 64.5 microgram per cubic meter (μg/m3) (16-304). For every 10 μg/m3 rise in PM10 concentration, there was a lag time of 6 days for asthma exacerbations [Adjusted relative risk (RR)=1.020; 95% confident interval (CI), 1.001-1.040; (p=0.014)], 7 days for COPD exacerbations [RR=1.030; 95%CI, 1.010-1.050 (p=0.024)] and 7 days for all exacerbations [RR=1.030 95%CI, 1.010-1.040 (p<0.001)]. This study confirms the effect of increasing PM₁₀ concentrations from seasonal smog on asthma and COPD exacerbations. However, there was an approximately 1 week lag time between the elevated PM₁₀ levels and time to emergency visits due to disease exacerbation.

  8. Establishment and evaluation of a rat model of inhalation lung injury induced by ship smog

    Directory of Open Access Journals (Sweden)

    Xin-xin DUAN

    2018-03-01

    Full Text Available Objective To establish and evaluate a rat model of inhalation lung injury induced by ship smog. Methods A rat model of inhalation lung injury was established by analyzing the composition of ship materials after combustion. Forty- two healthy male Wistar rats were randomly divided into normal control group and 2, 6, 12, 24, 48 and 72h groups (6 eachafter inhalation, these rats were killed at each time point, and the changes of arterial blood gas, coagulation function, the lung water content (% were detected. Macroscopic and microscopic changes in lung tissues were observed to judge the degree of lung injury. Results The main components after combustion of 7 kinds of nonmetal materials on ship included CO, CO2, H2S, NOx and other harmful gases in this study, AIKE in one gas detector was used to monitor O2, CO, CO2 and H2S, and their concentrations remained relatively stable within 15 minutes, and the injury time was 15 minutes. The rats presented with shortness of breath and mouth breathing. Smoke inhalation caused a significant hypoxemia, the concentration of blood COHb reached a peak value 2h and the lung water content (% did 6h after inhalation (P<0.05. It is metabolic acidosis in the early stage after inhalation, but metabolic acidosis combined with respiratory acidosis in the later period. Histopathological observation showed diffuse hemorrhage, edema and inflammatory cell infiltration in the lung tissue as manifestations of lung injury, and the injury did not recover at 72h after inhalation, the change of blood coagulation function was not statistically significant. Conclusion A rat model of inhalation lung injury induced by ship smog has been successfully established, and has the advantages of easy replication, stability and reliability, thus can be used to research and treat inhalation lung injury induced by ship smog in naval war environment and other cases. DOI: 10.11855/j.issn.0577-7402.2018.03.14

  9. Track photographing in 8-m streamer chamber

    International Nuclear Information System (INIS)

    Anisimova, N.Z.; Davidenko, V.A.; Kantserov, V.A.; Rybakov, V.G.; Somov, S.V.

    1981-01-01

    A system for obtaining data from a streamer chamber intended for measuring muon polarization is described. An optical scheme for photographing of tracks in the chamber is given. The photographing process is complicated at the expense of large dimensions and module structure of the chamber as well as due to insufficient for direct photographing brightness of streamers. The system described was tested during a long time in a physical experiment. More than 100 thousand photos have been taken by its means [ru

  10. Smog episodes in the Lodz agglomeration in the years 2014-17

    Directory of Open Access Journals (Sweden)

    Wielgosiński Grzegorz

    2018-01-01

    Full Text Available In recent years, in the winter season we are alarmed about the poor air quality in Poland and significantly exceeded permissible concentrations of certain pollutants, especially PM10 and PM2.5, which are a result of so-called low emissions. The authors analyze smog episodes in the Lodz agglomeration by comparing the recorded values of selected pollutant concentrations at monitoring stations of the Regional Inspectorate for Environmental Protection in Lodz with the meteorological conditions prevailing at this time. The analysis covers data from the years 2014-2017.

  11. Smog episodes in the Lodz agglomeration in the years 2014-17

    Science.gov (United States)

    Wielgosiński, Grzegorz; Czerwińska, Justyna; Namiecińska, Olga; Cichowicz, Robert

    2018-01-01

    In recent years, in the winter season we are alarmed about the poor air quality in Poland and significantly exceeded permissible concentrations of certain pollutants, especially PM10 and PM2.5, which are a result of so-called low emissions. The authors analyze smog episodes in the Lodz agglomeration by comparing the recorded values of selected pollutant concentrations at monitoring stations of the Regional Inspectorate for Environmental Protection in Lodz with the meteorological conditions prevailing at this time. The analysis covers data from the years 2014-2017.

  12. Relationship between subjective symptom classifications in photochemical smog incidents and air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Noushi, H; Nagasaki, M; Mizoguchi, I

    1973-04-01

    Investigation was conducted twice on 74 and 50 junior high school students having subjective symptoms of injury from smog on June 25 and July 8 of 1972. Among the first group there were 27 cases of headache, 18 cases of weakness, 13 cases of malaise, 11 cases of eye irritation, 9 cases of throat pain, and others. The second group showed a comparable number of cases for each individual symptom. Classification of the symptoms and pollution index showed relationships between oxidants and breathing difficulties, numbness of hands and legs, and throat pain, and also relationships between sulfur dioxide and eye irritation, throat pain, weakness, malaise, coughing, and dizziness.

  13. Tackling Air Pollution in China—What do We Learn from the Great Smog of 1950s in LONDON

    Directory of Open Access Journals (Sweden)

    Dongyong Zhang

    2014-08-01

    Full Text Available Since the prolonged, severe smog that blanketed many Chinese cities in first months of 2013, living in smog has become “normal” to most people living in mainland China. This has not only caused serious harm to public health, but also resulted in massive economic losses in many other ways. Tackling the current air pollution has become crucial to China’s long-term economic and social sustainable development. This paper aims to find the causes of the current severe air quality and explore the possible solutions by reviewing the current literature, and by comparing China’s air pollution regulations to that of the post London Killer Smog of 1952, in the United Kingdom (UK. It is hoped that China will learn the lesson from the UK, and decouple its economic growth from the detrimental impact of environment. Policy suggestions are made.

  14. Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

    Directory of Open Access Journals (Sweden)

    H. Fuchs

    2012-07-01

    Full Text Available During recent field campaigns, hydroxyl radical (OH concentrations that were measured by laser-induced fluorescence (LIF were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK, methacrolein (MACR and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD, China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS. Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s−1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03 × 106 cm−3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30–40% (median larger than those by DOAS after MVK (20 ppbv and

  15. Dual ionization chamber

    International Nuclear Information System (INIS)

    Mallory, J.; Turlej, Z.

    1981-01-01

    Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

  16. An anxiety, personality and altitude symptomatology study during a 31-day period of hypoxia in a hypobaric chamber (experiment 'Everest-Comex 1997').

    Science.gov (United States)

    Nicolas, M; Thullier-Lestienne, F; Bouquet, C; Gardette, B; Gortan, C; Joulia, F; Bonnon, M; Richalet, J P; Therme, P; Abraini, J H

    1999-12-01

    Extreme environmental situations are useful tools for the investigation of the general processes of adaptation. Among such situations, high altitude of more than 3000 m produces a set of pathological disorders that includes both cerebral (cAS) and respiratory (RAS) altitude symptoms. High altitude exposure further induces anxiety responses and behavioural disturbances. The authors report an investigation on anxiety responses, personality traits, and altitude symptoms (AS) in climbers participating in a 31-day period of confinement and gradual decompression in a hypobaric chamber equivalent to a climb from sea-level to Mount Everest (8848 m altitude). Personality traits, state-trait anxiety, and AS were assessed, using the Cattell 16 Personality Factor questionnaire (16PF), the Spielberger's State-Trait Anxiety Inventory (STAI), and the Lake Louise concensus questionnaire. Results show significant group effect for state-anxiety and AS; state-anxiety and AS increased as altitude increased. They also show that state-type anxiety shows a similar time-course to cAS, but not RAS. Alternatively, our results demonstrate a significant negative correlation between Factor M of the 16PF questionnaire, which is a personality trait that ranges from praxernia to autia. In contrast, no significant correlation was found between personality traits and AS. This suggests that AS could not be predicted using personality traits and further support that personality traits, such as praxernia (happening sensitivity), could play a major role in the occurrence of state-type anxiety responses in extreme environments. In addition, the general processes of coping and adaptation in individuals participating in extreme environmental experiments are discussed.

  17. [A study on the role of vascular endothelial growth factor in emphysema of rat caused by smog exposure].

    Science.gov (United States)

    Chen, Jin-long; Ran, Pi-xin

    2003-11-01

    To explore the role of vascular endothelial growth factor (VEGF) in emphysema of rat caused by smog exposure. Thirty-six 12-week male rats were randomly divided into 2 groups: a smog exposure group (S group), and a normal control group (N group). S group rats were randomly subdivided into 3 groups: S(1) group, S(2) group, S(3) group, which were exposed to smog for 2 weeks, 4 weeks, 8 weeks, respectively; N group rats were randomly subdivided into 3 groups: N(1) group, N(2) group, N(3) group, which were raised in normal oxygen condition for 0 week, 4 weeks, 8 weeks, respectively. The expressions of VEGF mRNA and VEGF protein and kinase-insert domain containing receptor (KDR) protein were determined by reverse transcription-polymerase chain reaction (RT-PCR) and modified SABC immunohistochemistry assay separately. The pathological change in smog exposure rat lung was determined by HE staining. MLI and MAN were determined as an index of emphysema. Variance analysis, nonparametric analysis and correlate analysis were conducted in SPSS 10.0. (1) There were airway inflammation in S group rat lungs, and an early-emphysema-like change in S(3) group rat lungs: MAN in S(3) group was significantly decreased compared with N(3) group, MLI in S(3) group was significantly increased compared with N(3) group (P 0.05). (3) VEGF protein expression in alveolar epithelium and bronchial epithelium had a positive correlation with MAN (r = 0.43, r = 0.37, P Smog exposure decrease the expression of VEGF and KDR in rat lung. VEGF might involve in the pathology of emphysema caused by smog exposure.

  18. Social acceptance towards the air pollution in China: Evidence from public's willingness to pay for smog mitigation

    International Nuclear Information System (INIS)

    Sun, Chuanwang; Yuan, Xiang; Yao, Xin

    2016-01-01

    Air pollution is one of the most predominant challenges in China. In order to ensure the smog governance projects could be promoted smoothly and the public shoulder the environmental responsibilities consciously, it is necessary for the policymakers to take public attitude into consideration, and understand the public willingness to pay (WTP) for smog mitigation. This paper adopts a CV method framework to assess the value of WTP and analyze the determinants. Given the consideration of the possible presence of the selectivity bias caused by protest responses, the bivariate sample selection model is constructed for estimation. Results show that up to 14% of respondents hold the protest responses, and neglecting the selection bias caused by protest responses would lead to downward biased estimates. The mean value of WTP for the smog mitigation is 1590.36 RMB per year, accounting for about 1% of annual income. Moreover, the NIMBY (not in my backyard) attitude among public is found to be significantly correlated with their WTP, and the other determinants such as household annual income, energy expenditure and economic loss caused by smog could also substantially affect the value of WTP. We further recommend grading governance and policy transparency to address the smog crisis. - Highlights: •Evaluating the social acceptance towards the air pollution in China. •Up to 14% of respondents hold the protest responses. •WTP for the smog mitigation accounts for about 1% of income. •Household energy expenditure is closely related with public's WTP. •The grading governance and policy transparency are recommended.

  19. Laboratory Course on Drift Chambers

    International Nuclear Information System (INIS)

    Garcia-Ferreira, Ix-B.; Garcia-Herrera, J.; Villasenor, L.

    2006-01-01

    Drift chambers play an important role in particle physics experiments as tracking detectors. We started this laboratory course with a brief review of the theoretical background and then moved on to the the experimental setup which consisted of a single-sided, single-cell drift chamber. We also used a plastic scintillator paddle, standard P-10 gas mixture (90% Ar, 10% CH4) and a collimated 90Sr source. During the laboratory session the students performend measurements of the following quantities: a) drift velocities and their variations as function of the drift field; b) gas gains and c) diffusion of electrons as they drifted in the gas

  20. Bicone vacuum chamber for ISR intersection

    CERN Multimedia

    1975-01-01

    This is one of the bicone chambers made of titanium for experiment R 702. The central corrugated part had a very thin titanium wall (0.28 mm). The first of these chambers collapsed in its central part when baked at 300 C (August 1975). After an intensive effort to develop better quality and reproducible welds for this special material, the ISR workshop was able to build two new chambers of this type. One of them was installed at I 7 for R 702 in 1976 and worked perfectly. It was at that time the most "transparent" intersection vacuum chamber. See also 7609219, 7609221.

  1. Drift chamber vertex detectors for SLC/LEP

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, K G

    1988-03-01

    Factors influencing the design of drift chamber vertex detectors for SLC and LEP are discussed including global strategy, chamber gas, cell design, and signal processing. The designs of the vertex chambers for the L3 and OPAL experiments at LEP and the Mark II experiment at the SLC are described.

  2. Vertical gradients of nitrous acid (HONO) measured in Beijing during winter smog events.

    Science.gov (United States)

    Kramer, Louisa; Crilley, Leigh; Thomson, Steven; Bloss, William; Tong, Shengrui

    2017-04-01

    HONO is an important atmospheric constituent, as the photolysis of HONO leads to the formation of OH radicals in the boundary layer, with contributions of up to 60% in urban regions. This is particularly important in mega-cities, such as Beijing, where measured HONO levels can reach parts per billion. Research has shown that direct emissions, homogeneous gas phase reactions and heterogeneous conversion of NO2 on surfaces all contribute to HONO in urban areas. There are, however, still uncertainties regarding the magnitude of these sources, and models are still unable to account for total measured HONO mixing ratios. To assess the sources of HONO, vertical profile measurements were performed up to an altitude of 260 m on the Institute of Atmospheric Physics (IAP) Meteorological Tower in Beijing. These measurements were performed as part of the Air Pollution and Human Health (APHH) project, during Nov/Dec 2016. Here we present HONO profile measurements using a long-path absorption photometer (LOPAP), during both clear and hazy days. HONO levels near the ground were very high during smog events with concentrations over 10 ppb observed. The data show a strong negative gradient with altitude, suggesting a source close to the surface. The largest gradients were observed overnight during smog events, with differences in HONO between the ground and the highest level up to 6 ppb.

  3. Double chamber ion source

    International Nuclear Information System (INIS)

    Uman, M.F.; Winnard, J.R.; Winters, H.F.

    1978-01-01

    The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

  4. OPAL jet chamber full-scale prototype

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D; Mazzone, L

    1986-12-01

    The concept of a jet chamber for the central detector of OPAL was tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration, and readout are described. Operating experience was gathered since summer 1984. The chamber performance in terms of spatial resolution and particle identification capability is given.

  5. Triangular tube proportional wire chamber system

    Energy Technology Data Exchange (ETDEWEB)

    Badtke, D H; Bakken, J A; Barnett, B A; Blumenfeld, B J; Chien, C Y; Madansky, L; Matthews, J A.J.; Pevsner, A; Spangler, W J [Johns Hopkins Univ., Baltimore, MD (USA); Lee, K L [California Univ., Berkeley (USA). Lawrence Berkeley Lab.

    1981-10-15

    We report on the characteristics of the proportional tube chamber system which has been constructed for muon identification in the PEP-4 experiment at SLAC. The mechanical and electrical properties of the extruded aluminum triangular tubes allow these detectors to be used as crude drift chambers.

  6. Tests of the data acquisition system and detector control system for the muon chambers of the CMS experiment at the LHC

    CERN Document Server

    Sowa, Michael Christian

    The Phys. Inst. III A of RWTH Aachen University is involved in the development, production and tests of the Drift Tube (DT) muon chambers for the barrel muon system of the CMS detector at the LHC at CERN (Geneva). The thesis describes some test procedures which were developed and performed for the chamber local Data Acquisition (DAQ) system, as well as for parts of the Detector Control System (DCS). The test results were analyzed and discussed. Two main kinds of DAQ tests were done. On the one hand, to compare two different DAQ systems, the chamber signals were split and read out by both systems. This method allowed to validate them by demonstrating, that there were no relevant differences in the measured drift times, generated by the same muon event in the same chamber cells. On the other hand, after the systems were validated, the quality of the data was checked. For this purpose extensive noise studies were performed. The noise dependence on various parameters (threshold, HV) was investigated quantitativel...

  7. Re-evaluation of the Pressure Effect for Nucleation in Laminar Flow Diffusion Chamber Experiments with Fluent and the Fine Particle Model

    Czech Academy of Sciences Publication Activity Database

    Herrmann, E.; Hyvärinen, A.-P.; Brus, David; Lihavainen, H.; Kulmala, M.

    2009-01-01

    Roč. 113, č. 8 (2009), s. 1434-1439 ISSN 1089-5639 Institutional research plan: CEZ:AV0Z40720504 Keywords : laminar flow diffusion chamber * experimental data * fine particle model Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.899, year: 2009

  8. Measurement of profile and intensity of proton beam by an integrating current transformer and a segmented parallel-plate ion chamber for the AGS-spallation target experiment (ASTE)

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Nakashima, Hiroshi; Takada, Hiroshi

    2001-03-01

    Profile and intensity of proton beams incident to a mercury target were measured for the experiments under AGS-spallation Target Experiment (ASTE) collaboration. Protons of 1.94, 12 and 24 GeV energy were measured for a temperature, pressure wave and neutronics in the mercury target. For the beam profile measurement, segmented parallel-plate ion chamber (CHIDORI) was used as the online detector. Imaging plates (IP) were also used for the profile measurement with aluminum activation foils as the image converter. An integrating current transformer (ICT) and activation method by Cu foil were used for the measurement of beam intensity. The beam profile obtained by CHIDORI gives a good agreement with the results with the IP. The beam intensity obtained by ICT agrees with the data obtained by the activation technique within ±3% for 12 and 24 GeV cases. Furthermore, these results show in good agreement with those obtained by the monitor of segmented wire ionization chamber (SWIC) and secondary emission chamber (SEC) installed by the AGS team. Therefore, a reliable beam monitor technique was established, so that the analysis of the experiment such as temperature and pressure wave can be normalized by the number of incident protons. (author)

  9. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  10. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  11. DORIOT CLIMATIC CHAMBERS

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

  12. Gas microstrip chambers

    International Nuclear Information System (INIS)

    McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

    1992-01-01

    The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

  13. Holographic processing of track chamber data

    Energy Technology Data Exchange (ETDEWEB)

    Bykovsky, Y A; Larkin, A I; Markilov, A A; Starikov, S N [Moskovskij Fiziko-Tekhnicheskij Inst. (USSR)

    1975-12-01

    The holographic pattern recognition method was applied for processing of track chamber photographs. Experiments on detection of such events as a definitely directed track, an angle formed by two tracks, a three-pronged star, a definitely curved track were performed by using models. It is proposed to recognize these events in a filmshot by the shape of correlation signals. The experiment to recognize the event in a real bubble chamber filmshot was realized; requirements to the processing films were determined.

  14. Vertical distribution of optical and microphysical properties of smog aerosols measured by multi-wavelength polarization lidar in Xi'an, China

    Science.gov (United States)

    Di, Huige; Hua, Hangbo; Cui, Yan; Hua, Dengxin; He, Tingyao; Wang, Yufeng; Yan, Qing

    2017-02-01

    In this study, a multi-wavelength polarization lidar was developed at the Lidar Center for Atmosphere Remote Sensing, in Xi'an, China to study the vertical distribution of the optical and microphysical properties of smog aerosols. To better understand smog, two events with different haze conditions observed in January 2015 were analyzed in detail. Using these data, we performed a vertical characterization of smog evolution using the lidar range-squared-corrected signal and the aerosol depolarization ratio. Using inversion with regularization, we retrieved the vertical distribution of aerosol microphysical properties, including volume size distribution, volume concentration, number concentration and effective radius. We also used the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model to analyze aerosol sources during the two episodes. Our results show that the most polluted area in the lower troposphere during smog episodes is located below a height of 1 km above the ground level; under more severe smog conditions, it can be below 0.5 km. In the case of severe smog, we found a large number of spherical and fine particles concentrated in the very low troposphere, even below 0.5 km. Surprisingly, a dust layer with a slight depolarization ratio was observed above the smog layer.

  15. Mortality during winter smog episodes 1982, 1985, 1987 and 1993 in the Czech Republic.

    Science.gov (United States)

    Jelínková, J; Branis, M

    2001-10-01

    Severe air pollution episodes were recorded during the 1980s and early 1990s in the Czech Republic as a result of widespread combustion of brown coal. A population-based retrospective study investigated the relationship between air pollution and daily mortality in six highly polluted areas of the Czech Republic during smog episodes in 1982, 1985, 1987, and 1993. Total daily mortality, mortality by gender and age, cardiovascular mortality, respiratory mortality, data on weekly incidence of acute respiratory diseases and daily mean concentrations of sulphur dioxide and suspended particulate matter were used in the model. The effects of smog on daily mortality were estimated by multiple linear regression analysis. Significant increases in mortality were observed for the 1982 and 1987 episodes (6% and 9%). In 1982, mortality was significantly associated with mean concentration of sulphur dioxide (SO2) of the current and the preceding days and with the 4-day moving average. In the 1985 episode a significant increase in respiratory mortality in men and in both genders together, lagging by 2 and 3 days, was detected. During the 1987 episode significant associations of total daily mortality, mortality in persons over 65 years of age and mortality from cardiovascular or respiratory diseases with 4-day moving average of both pollutants were found. For the 1993 episode a significant association between mortality in women under 65, lagging by 3 days, and mean concentration of suspended particulate matter (SPM) was observed. Most of the results are consistent with other studies aimed at episodic air pollution during the 1950s and 1960s in Western Europe and the USA, in which outdoor air pollution was shown to be a significant predictor of mortality. However, non-significant or opposite associations between air pollution and mortality indicate that other factors may also play an important role. A stronger effect on men under 65 years of age, suggested by a previous Czech study

  16. Variation of atmospheric aerosol components and sources during smog episodes in Debrecen, Hungary

    International Nuclear Information System (INIS)

    Angyal, A.; Kertész, Zs.; Szoboszlai, Z.; Szikszai, Z.; Ferenczi, Z.; Furu, E.; Tõrõk, Zs.

    2013-01-01

    Full text: Atmospheric particulate matter (APM) pollution is one of the leading environmental problems in densely populated urban environments. In most cities all around the world high aerosol pollution levels occurs regularly. Debrecen, an average middle-European city is no exception. Every year there are several days when the aerosol pollution level exceeds the alarm threshold value (100 μ-g/m 3 for PM10 in 24- hours average). When the PM10 pollution level remains over this limit value for days, it is called 'smog' by the authorities. In this work we studied the variation of the elemental components and sources of PM10, PM2.5 and PM coarse and their dependence on meteorological conditions in Debrecen during two smog episodes occurred in November 2011. Aerosol samples were collected with 2-hours time resolution with a PIXE International sequential streaker in an urban background site in the downtown of Debrecen. In order to get information about the size distribution of the aerosol elemental components 9-stage cascade impactors were also employed during the sampling campaigns. The elemental composition (Z ≥ 13) were determined by Particle Induced X-Ray Emission (PIXE) at the IBA Laboratory of Atomki. Concentrations of elemental carbon were measured with a smoke stain reflectometer. On this data base source apportionment was carried out by using the positive matrix factorisation (PMF) method. Four factors were identified for both size fractions, including soil dust, traffic, domestic heating, and oil combustion. The time pattern of the aerosol elemental components and PM sources exhibited strong dependence on the mixing layer thickness. We showed that domestic heating had a major contribution to the aerosol pollution. (This work was carried out in the frame of the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and TÁMOP-4.2.2/B-10/1-2010-0024 project). (author)

  17. Calculation of Wakefields and Higher Order Modes for the New Design of the Vacuum Chamber of the ALICE Experiment for the HL-LHC

    CERN Document Server

    Wanzenberg, Rainer; CERN. Geneva. ATS Department

    2016-01-01

    The High Luminosity Large Hadron Collider (HL-LHC) project was started with the goal to extend the discovery potential of the Large Hadron Collider (LHC). The HL-LHC study implies also an upgraded dimensions of the ALICE beam pipe. The trapped monopole and dipole Higher Order Modes (HOMs) and the short range wakefields for the new design of the ALICE vacuum chamber were calculated with help of the computer codes MAFIA and ECHO2D. The results of the short range wakefields calculations and the HOMs calculations for the ALICE vacuum chamber with new dimensions are presented in this report. The short range wakefields are presented in terms of longitudinal and transverse wake potentials and also in terms of loss and kick parameters. The frequency, the loss parameter, the R/Q and the Qvalues and also power loss parameters are presented as result of the HOMs calculations and can be converted into impedance values.

  18. MPS II drift chamber system

    International Nuclear Information System (INIS)

    Platner, E.D.

    1982-01-01

    The MPS II detectors are narrow drift space chambers designed for high position resolution in a magnetic field and in a very high particle flux environment. Central to this implementation was the development of 3 multi-channel custom IC's and one multi-channel hybrid. The system is deadtimeless and requires no corrections on an anode-to-anode basis. Operational experience and relevance to ISABELLE detectors is discussed

  19. Feasibility study of a synchronized-moving-grid (SMOG) system to improve image quality in cone-beam computed tomography (CBCT).

    Science.gov (United States)

    Ren, Lei; Yin, Fang-Fang; Chetty, Indrin J; Jaffray, David A; Jin, Jian-Yue

    2012-08-01

    To evaluate the feasibility of a synchronized moving grid (SMOG) system to remove scatter artifacts, improve the contrast-to-noise ratio (CNR), and reduce image lag artifacts in cone-beam CT (CBCT). The SMOG system proposed here uses a rapidly oscillating, synchronized moving grid attached to the kV source. Multiple partial projections are taken at different grid positions to form a complete projection in each gantry position, before the gantry moves to the next position during a scan. The grid has a low transmission factor, and it is used for both scatter reduction and scatter measurement for postscan scatter correction. Experimental studies using a static grid and an enlarged CATphan phantom were performed to evaluate the potential CNR enhancement for different SMOG exposure numbers (1, 2, and 4). Simulation studies were performed to evaluate the image lag correction for different exposure numbers (2, 3, and 4) and grid interspace widths in SMOG using the data from an anthropomorphic pelvis phantom scan. Imaging dose of SMOG was also estimated by measuring the imaging dose in a CIRS CT dose phantom using a static grid. SMOG can enhance the CNR by 16% and 13% when increasing exposure number from 1 to 2 and from 2 to 4, respectively. This enhancement was more dramatic for larger phantoms and smaller initial exposure numbers. Simulation results indicated that SMOG could reduce the lag to less than 4.3% for 2-exposure mode and to less than 0.8% for 3-exposure mode when the grid interspace width was 1.4 cm. Increasing the number of exposures in SMOG dramatically reduced the residual lag in the image. Reducing the grid interspace width somewhat reduced the residual lag. Skin line artifacts were removed entirely in SMOG. Point dose measurement showed that imaging dose of SMOG at isocenter was similar as that of a conventional CBCT. Compared to our previously developed static-grid dual-rotation method, the proposed SMOG technique has the advantages of enhancing the CNR

  20. Feasibility study of a synchronized-moving-grid (SMOG) system to improve image quality in cone-beam computed tomography (CBCT)

    International Nuclear Information System (INIS)

    Ren Lei; Yin Fangfang; Chetty, Indrin J.; Jaffray, David A.; Jin Jianyue

    2012-01-01

    Purpose: To evaluate the feasibility of a synchronized moving grid (SMOG) system to remove scatter artifacts, improve the contrast-to-noise ratio (CNR), and reduce image lag artifacts in cone-beam CT (CBCT). Methods: The SMOG system proposed here uses a rapidly oscillating, synchronized moving grid attached to the kV source. Multiple partial projections are taken at different grid positions to form a complete projection in each gantry position, before the gantry moves to the next position during a scan. The grid has a low transmission factor, and it is used for both scatter reduction and scatter measurement for postscan scatter correction. Experimental studies using a static grid and an enlarged CATphan phantom were performed to evaluate the potential CNR enhancement for different SMOG exposure numbers (1, 2, and 4). Simulation studies were performed to evaluate the image lag correction for different exposure numbers (2, 3, and 4) and grid interspace widths in SMOG using the data from an anthropomorphic pelvis phantom scan. Imaging dose of SMOG was also estimated by measuring the imaging dose in a CIRS CT dose phantom using a static grid. Results: SMOG can enhance the CNR by 16% and 13% when increasing exposure number from 1 to 2 and from 2 to 4, respectively. This enhancement was more dramatic for larger phantoms and smaller initial exposure numbers. Simulation results indicated that SMOG could reduce the lag to less than 4.3% for 2-exposure mode and to less than 0.8% for 3-exposure mode when the grid interspace width was 1.4 cm. Increasing the number of exposures in SMOG dramatically reduced the residual lag in the image. Reducing the grid interspace width somewhat reduced the residual lag. Skin line artifacts were removed entirely in SMOG. Point dose measurement showed that imaging dose of SMOG at isocenter was similar as that of a conventional CBCT. Conclusions: Compared to our previously developed static-grid dual-rotation method, the proposed SMOG technique

  1. An electrodeless drift chamber

    International Nuclear Information System (INIS)

    Allison, J.; Barlow, R.J.; Bowdery, C.K.; Duerdoth, I.; Rowe, P.G.

    1982-01-01

    We describe a chamber in which the drift field is controlled by the deposition of electrostatic charge on an insulating surface. The chamber operates with good efficiency and precision for observed drift distances of up to 45 cm, promises to be extremely robust and adaptable and offers a very cheap way of making particle detectors. (orig.)

  2. High resolution drift chambers

    International Nuclear Information System (INIS)

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 μm resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs

  3. Plastic flashtube chambers

    International Nuclear Information System (INIS)

    Frisken, W.R.

    1977-01-01

    A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

  4. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  5. BEBC bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  6. The Mobile Chamber

    Science.gov (United States)

    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.

  7. Bi-cone vacuum chamber in the ISR

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The "bi-cone" vacuum chamber in ISR intersection I-7, for experiment R702. Made from 0.28 mm thick titanium, it was at its time the most transparent chamber ever built. Ian Wilson is standing next to the chamber. See also 7609219.

  8. Multispecimen dual-beam irradiation damage chamber

    International Nuclear Information System (INIS)

    Packan, N.H.; Buhl, R.A.

    1980-06-01

    An irradiation damage chamber that can be used to rapidly simulate fast neutron damage in fission or fusion materials has been designed and constructed. The chamber operates in conjunction with dual Van de Graaff accelerators at ORNL to simulate a wide range of irradiation conditions, including pulsed irradiation. Up to six experiments, each with up to nine 3-mm disk specimens, can be loaded into the ultrahigh vacuum chamber. Specimen holders are heated with individual electron guns, and the temperature of each specimen can be monitored during bombardment by an infrared pyrometer. Three different dose levels may be obtained during any single bombardment, and the heavy-ion flux on each of the nine specimens can be measured independently with only a brief interruption of the beam. The chamber has been in service for nearly three years, during which time approximately 250 bombardments have been successfully carried out. An appendix contains detailed procedures for operating the chamber

  9. Structural Analysis of Extended Plasma Focus Chamber

    International Nuclear Information System (INIS)

    Mohd Azhar Ahmad; Abdul Halim Baijan; Siti Aiasah Hashim

    2016-01-01

    Accelerator Development Centre (ADC) of Nuclear Malaysia intends to upgrade the plasma focus device. It involves the extension part placed on top of the existing plasma focus vacuum chamber. This extended vacuum chamber purposely to give an extra space in conducting experiments on the existing plasma focus chamber. The aim of upgrading the plasma focus device is to solve the limitation in research and analysis of sample due to its done in an open system that cause analysis of samples is limited and less optimal. This extended chamber was design in considering the ease of fabrication as well as durability of its structural. Thus, this paper discusses the structural analysis in term of pressure loading effect in extended chamber. (author)

  10. Note: Small anaerobic chamber for optical spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chauvet, Adrien A. P., E-mail: adrien.chauvet@gmail.com; Chergui, Majed [Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, Station 6, 1015 Lausanne (Switzerland); Agarwal, Rachna; Cramer, William A. [Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 (United States)

    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, to the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment.

  11. Hyperbaric and hypobaric chamber fires: a 73-year analysis.

    Science.gov (United States)

    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 (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.

  12. Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

    Directory of Open Access Journals (Sweden)

    C. J. Hennigan

    2011-08-01

    Full Text Available Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III. We investigated emissions from 12 different fuels commonly burned in North American wildfires. The experiments feature atmospheric and plume aerosol and oxidant concentrations; aging times ranged from 3 to 4.5 h. OA production, expressed as a mass enhancement ratio (ratio of OA to primary OA (POA mass, was highly variable. OA mass enhancement ratios ranged from 2.9 in experiments where secondary OA (SOA production nearly tripled the POA concentration to 0.7 in experiments where photo-oxidation resulted in a 30 % loss of the OA mass. The campaign-average OA mass enhancement ratio was 1.7 ± 0.7 (mean ± 1σ; therefore, on average, there was substantial SOA production. In every experiment, the OA was chemically transformed. Even in experiments with net loss of OA mass, the OA became increasingly oxygenated and less volatile with aging, indicating that photo-oxidation transformed the POA emissions. Levoglucosan concentrations were also substantially reduced with photo-oxidation. The transformations of POA were extensive; using levoglucosan as a tracer for POA, unreacted POA only contributed 17 % of the campaign-average OA mass after 3.5 h of exposure to typical atmospheric hydroxyl radical (OH levels. Heterogeneous reactions with OH could account for less than half of this transformation, implying that the coupled gas-particle partitioning and reaction of semi-volatile vapors is an important and potentially dominant mechanism for POA processing. Overall, the results illustrate that biomass burning emissions are subject to extensive chemical processing in the atmosphere, and the timescale for these transformations is rapid.

  13. Hydrostatic Hyperbaric Chamber Ventilation System

    Science.gov (United States)

    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

  14. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  15. Acoustic-Levitation Chamber

    Science.gov (United States)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  16. Optical spark chamber

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    An optical spark chamber developed for use in the Omega spectrometer. On the left the supporting frame is exceptionally thin to allow low momentum particles to escape and be detected outside the magnetic field.

  17. Vacuum chamber 'bicone'

    CERN Multimedia

    1977-01-01

    This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

  18. Miniature ionization chamber

    International Nuclear Information System (INIS)

    Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

    1976-01-01

    A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

  19. Reference ionization chamber

    International Nuclear Information System (INIS)

    Golnik, N.; Zielczynski, M.

    1999-01-01

    The paper presents the design of ionization chamber devoted for the determination of the absolute value of the absorbed dose in tissue-equivalent material. The special attention was paid to ensure that the volume of the active gas cavity was constant and well known. A specific property of the chamber design is that the voltage insulators are 'invisible' from any point of the active volume. Such configuration ensures a very good time stability of the electrical field and defines the active volume. The active volume of the chamber was determined with accuracy of 0.3%. This resulted in accuracy of 0.8% in determination of the absorbed dose in the layer of material adherent to the gas cavity. The chamber was applied for calibration purposes at radiotherapy facility in Joint Institute for Nuclear Research in Dubna (Russia) and in the calibration laboratory of the Institute of Atomic Energy in Swierk. (author)

  20. Gridded ionization chamber

    International Nuclear Information System (INIS)

    Houston, J.M.

    1977-01-01

    An improved ionization chamber type x-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is disposed adjacent the anode and is maintained at a voltsge intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting toward the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  1. ALICE Time Projection Chamber

    CERN Multimedia

    Lippmann, C

    2013-01-01

    The Time Projection Chamber (TPC) is the main device in the ALICE 'central barrel' for the tracking and identification (PID) of charged particles. It has to cope with unprecedented densities of charges particles.

  2. Possibilities of climate reconstruction in the Holocene using δ13C and δ2H values from annual tree rings on the basis of climate chamber experiments and studies on present-day organisms

    International Nuclear Information System (INIS)

    Mayr, C.

    2002-01-01

    This study deals with the climatic information content of 2 H and 13 C levels in annual tree rings and plant material. The influence of variations in air temperature, relative humidity and water availability on stable isotope ratios in three different C 3 plant species (Brassica oleracea, Eucalyptus globulus, Vicia faba) was studied in climate chamber experiments. Furthermore, calibration studies using δ 13 C and δ 2 H time series from Southern German spruce (Picea abies) from two stands (Schussbach, Klosterreichenbach) were performed. Correlations with meteorological data from a nearby meteorological station prove stable isotope ratios to be dependent on weather conditions in the summer months (June through August). Using the δ 13 C ''response surfaces'' obtained from these experiments as well as correlations from long gridbox precipitation series it was shown that for the climate mode under study the δ 13 C values largely reflect water availability to trees, which is greatly influenced by summer precipitation, especially at the more arid of the two sites. The results of the climate chamber experiments also suggest that the spruce δ 2 H values largely reflect the isotope variation in soil water and hence the δ 2 H fluctuations in summer precipitation. The study closes with a discussion of methodological approaches to creating long isotope series from annual tree rings of subfossil oak trees

  3. The large cylindrical drift chamber of TASSO

    International Nuclear Information System (INIS)

    Boerner, H.; Fischer, H.M.; Hartmann, H.; Loehr, B.; Wollstadt, M.; Fohrmann, R.; Schmueser, P.; Cassel, D.G.; Koetz, U.; Kowalski, H.

    1980-03-01

    We have built and operated a large cylindrical drift chamber for the TASSO experiment at the DESY storage ring, PETRA. The chamber has a length of 3.5 m, a diameter of 2.5 m, and a total of 2340 drift cells. The cells are arranged in 15 concentric layers such that tracks can be reconstructed in three dimensions. A spatial resolution of 220 μm has been achieved for tracks of normal incidence on the drift cells. (orig.)

  4. Cylindrical geometry for proportional and drift chambers

    International Nuclear Information System (INIS)

    Sadoulet, B.

    1975-06-01

    For experiments performed around storage rings such as e + e - rings or the ISR pp rings, cylindrical wire chambers are very attractive. They surround the beam pipe completely without any dead region in the azimuth, and fit well with the geometry of events where particles are more or less spherically produced. Unfortunately, cylindrical proportional or drift chambers are difficult to make. Problems are discussed and two approaches to fabricating the cathodes are discussed. (WHK)

  5. OPAL jet chamber full scale prototype

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D; Mazzone, L

    1986-12-01

    The concept of a jet chamber for the central detector of OPAL has been tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration and readout are described. Operating experience has been gathered since summer 1984. The chamber performance in terms of spatial resolution and particle identification capability is given.

  6. OPAL jet chamber full scale prototype

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstreom, R; Heuer, R D; Mazzone, L

    1986-05-22

    The concept of a jet chamber for the central detector of OPAL has been tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration and readout are described. The operating experience gathered since the summer of 1984 and the chamber performance as measured by its spatial resolution and ability to identify particles are also given.

  7. Gridded Ionization Chamber

    International Nuclear Information System (INIS)

    Manero Amoros, F.

    1962-01-01

    In the present paper the working principles of a gridded ionization chamber are given, and all the different factors that determine its resolution power are analyzed in detail. One of these devices, built in the Physics Division of the JEN and designed specially for use in measurements of alpha spectroscopy, is described. finally the main applications, in which the chamber can be used, are shown. (Author) 17 refs

  8. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  9. Sleeve reaction chamber system

    Science.gov (United States)

    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.

  10. Effects of Simulated Smog Atmospheres in Rodent Models of Metabolic and Immunologic Dysfunction.

    Science.gov (United States)

    McGee Hargrove, Marie; Snow, Samantha J; Luebke, Robert W; Wood, Charles E; Krug, Jonathan D; Krantz, Q Todd; King, Charly; Copeland, Carey B; McCullough, Shaun D; Gowdy, Kymberly M; Kodavanti, Urmila P; Gilmour, M Ian; Gavett, Stephen H

    2018-03-06

    Air pollution is a diverse and dynamic mixture of gaseous and particulate matter, limiting our understanding of associated adverse health outcomes. The biological effects of two simulated smog atmospheres (SA) with different compositions but similar air quality health indexes were compared in a nonobese diabetic rat model (Goto-Kakizaki, GK) and three mouse immune models (house dust mite (HDM) allergy, antibody response to heat-killed pneumococcus, and resistance to influenza A infection). In GK rats, both SA-PM (high particulate matter) and SA-O 3 (high ozone) decreased cholesterol levels immediately after a 4-h exposure, whereas only SA-O 3 increased airflow limitation. Airway responsiveness to methacholine was increased in HDM-allergic mice compared with nonallergic mice, but exposure to SA-PM or SA-O 3 did not significantly alter responsiveness. Exposure to SA-PM did not affect the IgM response to pneumococcus, and SA-O 3 did not affect virus titers, although inflammatory cytokine levels were decreased in mice infected at the end of a 7-day exposure. Collectively, acute SA exposures produced limited health effects in animal models of metabolic and immune diseases. Effects of SA-O 3 tended to be greater than those of SA-PM, suggesting that gas-phase components in photochemically derived multipollutant mixtures may be of greater concern than secondary organic aerosol PM.

  11. Measuring the sensitivity of a boron-lined ion chamber

    International Nuclear Information System (INIS)

    Barton, D.M.

    1992-03-01

    Boron-lined ion chambers are used to monitor external neutron flux from fissionable materials assembled at the Los Alamos Critical Assembly Experiment Facility. The sensitivity of these chambers must be measured periodically in order to detect changes in filling gas and to evaluate other factors that may affect chamber performance. We delineate a procedure to measure ion chamber response using a particular neutron source ( 239 PuBe) in a particular moderating geometry of polyethylene. We also discuss use of the amplifier, high-voltage power supply, recorders, and scram circuits that comprise the complete ion chamber monitoring system

  12. Liquid ionization chambers for LET determination

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    Liquid ionization chambers [1] (LICs) have have been used in the last decades as background dosemeters. Since a few years LICs are also commercially available for dosimetry and are used for measurements of dose distributions where a high spatial distribution is necessary. Also in the last decades...... a differential equation applying several simplifications and approximations leading to discrepancies between theory and experiments [3]. The theory predicts the collection efficiency as a function of the electrical field and was applied for both air filled ionization chambers and liquid filled ionization...... chambers. For liquids the LET can be roughly deduced from the collection efficiency dependency on the electrical field inside a liquid ionization chambers [4] using an extrapolation method. We solved the fundamental differential equation again presented by Jaffe numerically, but now taking into account...

  13. Wire chambers: Trends and alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Regler, Meinhard

    1992-05-15

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

  14. Conception and test of an integrated circuit (ASIC): application to multiwire chambers and photomultipliers of the GRAAL experience; Conception et test d`un circuit integre (ASIC): application aux chambres multifils et aux photomultiplicateurs de l`experience GRAAL

    Energy Technology Data Exchange (ETDEWEB)

    Bugnet, H.

    1995-11-21

    The nuclear physics project GRAAL (GRenoble Anneau Accelerateur Laser) located at the European Synchrotron Radiation Facility (ESRF) in Grenoble produces a high energy photon beam with a maximum energy of 1.5 GeV. This gamma beam is obtained by Compton backscattering and can be polarized easily. It permits to probe, in an original way, the structure of the nucleon. The associated detector system includes multiwire proportional chambers and scintillator hodoscopes. A kit of six ASICs (Application Specific Integrated Circuit) has been developed and used for the signal processing and data conditioning up to the level of the data acquisition. This integrated electronics can be mounted right on the detectors. Obvious advantages, due to the reduction of the length of the wires and the number of connections, are an improvement of the signal quality and an increase of the reliability. The Wire Processor (WP), ASIC designed and tested during this thesis, treats the signals from the chamber wires and the photomultipliers. In one chip, there are two identical channels permitting the amplification, the amplitude discrimination, the generation of a programmable delay and the writing in a two state memory in case of coincidence with an external strobe signal. The measurement of the multiwire chamber efficiency demonstrates the functioning of the WP, the data conditioning electronics, the data acquisition and the chamber itself. (author). 62 refs., 111 figs., 13 tabs.

  15. Change of Pressing Chamber Conicalness at Briquetting Process in Briquetting Machine Pressing Chamber

    Directory of Open Access Journals (Sweden)

    Peter Križan

    2012-01-01

    Full Text Available In this paper, we will present the impact of the conical shape of a pressing chamber, an important structural parameter. Besides the known impact of the technological parameters of pressing chambers, it is also very important to pay attention to their structural parameters. In the introduction, we present a theoretical analysis of pressing chamber conicalness. An experiment aimed at detecting this impact was performed at our institute, and it showed that increasing the conicalness of a pressing chamber improves the quality of the final briquettes. The conicalness of the pressing chamber has a significanteffect on the final briquette quality and on the construction of briquetting machines. The experimental findings presented here show the importance of this parameter in the briquetting process.

  16. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  17. Modeling and simulation of critical parameters of the first chamber of the dimuon arm spectrometer of the Alice experiment; Modelisation et simulation de parametres critiques de la premiere station du spectrometre dimuons d'ALICE

    Energy Technology Data Exchange (ETDEWEB)

    Guez, D

    2003-10-01

    The Alice experiment that is dedicated to the study of ultra-relativistic heavy ion collisions, will take place in the future large hadron collider (LHC) at CERN. The dimuon arm spectrometer of the Alice experiment is devoted to the search of a new signature of the existence of the quark gluon plasma (QGP). The first chapter is dedicated to the physics notions linked to the study of QGP, a few signatures are proposed for the detection of QGP, particularly the signature concerning the production rate of quarkonium. The second chapter deals with particle detection involved in Alice experiment, the dimuon arm spectrometer is a detector dedicated to the track reconstruction of muons issued from the decay of heavy mesons from J/{psi} and {upsilon} families. The third and the fourth chapters present the studies made to integrate a reliable model of the dimuon arm in the global simulation code of Alice (Aliroot). The fifth chapter presents the software TB{sup 2} that has been developed within the framework of this thesis in order to check and control the output data when the detector is tested with a real particle beam. The sixth chapter presents the results of the tests that have been performed with a 7 GeV/c pion beam. These tests have shown that the electronic noise is coherent with the specifications of Alice experiment. A factor 1,8 between the highest and the weakest values of the gain has been measured in the chamber. The detection efficiency of the chamber has been estimated to 99% in the different cases studied. (A.C.)

  18. The challenge of building large area, high precision small-strip Thin Gap Trigger Chambers for the upgrade of the ATLAS experiment

    CERN Document Server

    Maleev, Victor; The ATLAS collaboration

    2015-01-01

    The current innermost stations of the ATLAS muon endcap system must be upgraded in 2018 and 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. Large area small-strip Thin Gap Chambers (sTGC) up to 2 m2 in size and totaling an active area of 1200 m2 will be employed for fast and precise triggering. The precision reconstruction of tracks requires a spatial resolution of about 100 μm to allow the Level-1 trigger track segments to be reconstructed with an angular resolution of 1mrad. The upgraded detector will consist of eight layers each of Micromegas and sTGC’s detectors together forming the ATLAS New Small Wheels. The position of each strip must be known with an accuracy of 30 µm along the precision coordinate and 80 µm along the beam. On such large area detectors, the mechanical precision is a key point and then must be controlled and monitored all along the process of construction and integrati...

  19. The Challenge of Building Large Area, High Precision Small-Strip Thin Gap Trigger Chambers for the Upgrade of the ATLAS Experiment

    CERN Document Server

    Maleev, Victor; The ATLAS collaboration

    2015-01-01

    The current innermost stations of the ATLAS muon end-cap system must be upgraded in 2018 and 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. Large area small-strip Thin Gap Chambers (sTGC) up to 2 $m^2$ in size and totaling an active area of 1200 $m^2$ will be employed for fast and precise triggering. The precision reconstruction of tracks requires a spatial resolution of about 100 $\\mu m$ while the Level-1 trigger track segments need to be reconstructed with an angular resolution of 1 mrad. The upgraded detector will consist of eight layers each of Micromegas and sTGC’s detectors together forming the ATLAS New Small Wheels. The position of each strip must be known with an accuracy of 40 $\\mu m$ along the precision coordinate and 80 $\\mu m$ along the beam. On such large area detectors, the mechanical precision is a key point and then must be controlled and monitored all along the process of cons...

  20. Growth responses, biomass partitioning, and nitrogen isotopes of prairie legumes in response to elevated temperature and varying nitrogen source in a growth chamber experiment.

    Science.gov (United States)

    Whittington, Heather R; Deede, Laura; Powers, Jennifer S

    2012-05-01

    Because legumes can add nitrogen (N) to ecosystems through symbiotic fixation, they play important roles in many plant communities, such as prairies and grasslands. However, very little research has examined the effect of projected climate change on legume growth and function. Our goal was to study the effects of temperature on growth, nodulation, and N chemistry of prairie legumes and determine whether these effects are mediated by source of N. We grew seedlings of Amorpha canescens, Dalea purpurea, Lespedeza capitata, and Lupinus perennis at 25/20°C (day/night) or 28/23°C with and without rhizobia and mineral N in controlled-environment growth chambers. Biomass, leaf area, nodule number and mass, and shoot N concentration and δ(15)N values were measured after 12 wk of growth. Both temperature and N-source affected responses in a species-specific manner. Lespedeza showed increased growth and higher shoot N content at 28°C. Lupinus showed decreases in nodulation and lower shoot N concentration at 28°C. The effect of temperature on shoot N concentration occurred only in individuals whose sole N source was N(2)-fixation, but there was no effect of temperature on δ(15)N values in these plants. Elevated temperature enhanced seedling growth of some species, while inhibiting nodulation in another. Temperature-induced shifts in legume composition or nitrogen dynamics may be another potential mechanism through which climate change affects unmanaged ecosystems.

  1. Hadronic interactions at energies around 103 TeV inferred from the large-scale emulsion chamber experiment at Mt. Fuji

    International Nuclear Information System (INIS)

    Akashi, M.; Amenomori, M.; Konishi, E.

    1981-01-01

    Details of experimental results, obtained with the large-scale emulsion chambers at Mt. Fuji (3776 m above sea level), are presented to investigate the hadronic interactions at energies around 10 3 TeV, comparing with the Monte Carlo simulation based on various assumed interaction models and primary particles. It may be briefly summarized as 1) Scaling in the fragmentation region can be valid up to 10 3 TeV at least only if the primary particles are mixed, with significant amounts of heavy nuclei at energies over 10 14 eV, 2) Cross sections should continue to increase with energy up to 10 3 TeV, at least, at almost the same rate as that obtained at lower energies, 3) There exist some evidence to indicate remarkable production of particles or jets with high P sub(t) of several GeV/c at energies around 10 3 TeV, 4) Hadron to gamma-ray ratios in the observed family events remain almost within the scope of simulation prediction. Other interesting characters of family events are also discussed. (author)

  2. Radon diffusion chamber

    International Nuclear Information System (INIS)

    Pretzsch, G.; Boerner, E.; Lehmann, R.; Sarenio, O.

    1986-01-01

    The invention relates to the detection of radioactive gases emitting alpha particles like radon, thoron and their alpha-decaying daughters by means of a diffusion chamber with a passive detector, preferably with a solid state track detector. In the chamber above and towards the detector there is a single metallized electret with negative polarity. The distance between electret and detector corresponds to the range of the alpha particles of radon daughters in air at the most. The electret collects the positively charged daughters and functions as surface source. The electret increases the sensitivity by the factor 4

  3. The Honeycomb Strip Chamber

    International Nuclear Information System (INIS)

    Graaf, Harry van der; Buskens, Joop; Rewiersma, Paul; Koenig, Adriaan; Wijnen, Thei

    1991-06-01

    The Honeycomb Strip Chamber (HSC) is a new position sensitive detector. It consists of a stack of folded foils, forming a rigid honeycomb structure. In the centre of each hexagonal cell a wire is strung. Conducting strips on the foils, perpendicular to the wires, pick up the induced avalanche charge. Test results of a prototype show that processing the signals form three adjacent strips nearest to the track gives a spatial resolution better than 64 μm for perpendicular incident tracks. The chamber performance is only slightly affected by a magnetic field. (author). 25 refs.; 21 figs

  4. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1982-01-01

    An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector

  5. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  7. The CAST Time Projection Chamber

    CERN Document Server

    Autiero, D.; Carmona, J.M.; Cebrian, S.; Chesi, E.; Davenport, M.; Delattre, M.; Di Lella, L.; Formenti, F.; Irastorza, I.G.; Gomez, H.; Hasinoff, M.; Lakic, B.; Luzon, G.; Morales, J.; Musa, L.; Ortiz, A.; Placci, A.; Rodriguez, A.; Ruz, J.; Villar, J.A.; Zioutas, K.

    2007-01-01

    One of the three X-ray detectors of the CAST experiment searching for solar axions is a Time Projection Chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity X-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is safely set during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62 %. Shielding has been installed around the detector, lowering the background level to 4.10 x 10^-5 counts/cm^2/s/keV between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion-photon coupling and mass.

  8. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  9. Heavy liquid bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  10. Drift chamber detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez Laso, L.

    1989-01-01

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  11. Drift Chambers detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez laso, L.

    1989-01-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs

  12. Improvements in ionization chambers

    International Nuclear Information System (INIS)

    Whetten, N.R.; Zubal, C.

    1980-01-01

    A method of reducing mechanical vibrations transmitted to the parallel plate electrodes of ionization chamber x-ray detectors, commonly used in computerized x-ray axial tomography systems, is described. The metal plate cathodes and anodes are mounted in the ionizable gas on dielectric sheet insulators consisting of a composite of silicone resin and glass fibres. (UK)

  13. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  14. MISSING: BUBBLE CHAMBER LENS

    CERN Multimedia

    2001-01-01

    Would the person who borrowed the large bubble chamber lens from the Microcosm workshops on the ISR please return it. This is a much used piece from our object archives. If anybody has any information about the whereabouts of this object, please contact Emma.Sanders@cern.ch Thank you

  15. Ion chamber instrument

    International Nuclear Information System (INIS)

    Stephan, D.H.

    1975-01-01

    An electrical ionization chamber is described having a self-supporting wall of cellular material which is of uniform areal density and formed of material, such as foamed polystyrene, having an average effective atomic number between about 4 and about 9, and easily replaceable when on the instrument. (auth)

  16. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  17. Wire chamber conference

    International Nuclear Information System (INIS)

    Bartl, W.; Neuhofer, G.; Regler, M.

    1986-02-01

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  18. Primary pollutants and potential photochemical smog formation in Makkah, Saudi Arabia

    International Nuclear Information System (INIS)

    Nasralla, M.M.; Seroji, A.R.

    2007-01-01

    This study was conducted in Mina Valley and the central district of the holy city, Makkah, during the pilgrimage (Hajj) season of 1424 Hijri (2004). During this season, more than 2.5 million people gathered in Makkah to perform the Hajj rituals. Two mobile air pollution laboratories were used to monitor NO, NO2, NOx, non-methane hydrocarbons and ozone (O3) in the atmosphere in Mina and Makkah. Instruments were calibrated periodically against standard gases. The present investigation showed clearly an ideal diurnal cycle of local ozone formation. Although the intensity of the incoming UV radiation was the lowest compared with other months of the year, recorded ozone levels approached the maximum allowable levels of 150 ug/m3 in Mina, and exceeded 160 ug/m3 in Makkah during the pilgrimage period. The problem was intensified by the high record levels NOx, sometimes reaching more than 800 ug/m3, 1h average, coupled with 1h average concentration of about 3 ppm non-methane hydrocarbons. Furthermore, the average maximum hourly ozone concentrations increased gradually from less than 60 ug/m3 during February to reach more than 200 ug/m3 (as an indication of smog formation) during some days of May. This coincides with the increase in the intensity of the incoming UV radiation reaching its maximum level in May. Consequently, it can be concluded that Makkah may face severe air pollution episodes when the pilgrimage season shifts to the summer months in the next few years. This may pose acute health problems for the elderly people and those with respiratory health problems. Good air quality and transportation management as well as the use of alternative clean fuel are highly recommended. (author)

  19. Quality control of ATLAS muon chambers

    CERN Document Server

    Fabich, Adrian

    ATLAS is a general-purpose experiment for the future Large Hadron Collider (LHC) at CERN. Its Muon Spectrometer will require ∼ 5500m2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5m to 15m length, embedded in a magnetic field of ∼ 0.5T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ∼ 1200 drift chambers. The performance of the MDT chambers is very much dependent on the mechanical quality of the chambers. The uniformity and stability of the performance can only be assured providing very high quality control during production. Gas tightness, high-voltage behaviour and dark currents are global parameters which are common to gas detectors. For all chambers, they will be tested immediately after the chamber assembly at every production site. Functional tests, for example radioactive source scans and cosmic-ray runs, will be performed in order to establish detailed performan...

  20. Proportional chambers and multiwire drift chambers at high rates

    International Nuclear Information System (INIS)

    Walenta, A.H.

    1977-01-01

    The high event and particle rates expected for ISABELLE intersecting storage rings raise the question whether PWC's and drift chambers, now widely in use in experiments, still can operate under such conditions. Various effects depend on the number of avalanches produced per length of wire N and the size of the avalanche Q, i.e., on the number of positive ions created in an avalanche. Therefore the important parameter for the following discussion is the product QN. The minimum Q is determined by the type and noise level of preamplifiers used. Examples are given for a typical low noise amplifier as well as for a typical integrated ''cheap'' amplifier. The rate/wire length N depends on the chamber arrangement, wire spacing, etc. In multiwire drift chambers, a single wire shows space-charge effects reducing the pulse height by 1% at a rate of N = 7 x 10 3 mm -1 sec -1 . At a rate of N approximately equal to 10 5 mm -1 sec -1 an efficiency loss of the order of 1% was noticed. The aging effect due to deposits on the anode wire can be reduced using low noise amplifiers and low gas gain to such an extent that a lifetime of about half a year at ISABELLE can be expected. The use of conventional cheap preamplifiers will result in a typical lifetime of about 30 days. Improvements are probable. The time resolution of Δt/sub r/ = 4 nsec fwhm seems adequate for event rates of 10 7 sec -1 . The memory time Δt/sub m/ greater than or equal to 100 nsec may cause serious problems for pattern recognition depending on layout and readout. The use of induced signals on cathode pads, thus reading out shorter parts of the wire, can solve the problem

  1. ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS

    International Nuclear Information System (INIS)

    Bradner, H.; Solmitz, F.

    1958-01-01

    Since its invention by Glaser in 1953, the bubble chamber has become a most valuable tool in high-energy physics. It combines a number of advantages of various older methods of particle detection: it offers high spatial resolution, rapid accumulation of data, some time resolution, and some choice of the nucleus whose interaction one wants to study (bubble chambers have been made to operate with a large number of different liquids, including H 2 , D 2 , He, Xe, and several hydrocarbons). In order to exploit the advantages of spatial resolution and rapid data accumulation, high-speed high-precision analysis procedures must be developed. In this article they discuss some of the problems posed by such analysis. The discussion is based largely on experience gained in performing hydrogen bubble chamber experiments with the University of California's Bevatron (6-Bev proton synchrotron)

  2. Source reconciliation of atmospheric gas-phase and particle-phase pollutants during a severe photochemical smog episode.

    Science.gov (United States)

    Schauer, James J; Fraser, Matthew P; Cass, Glen R; Simoneit, Bernd R T

    2002-09-01

    A comprehensive organic compound-based receptor model is developed that can simultaneously apportion the source contributions to atmospheric gas-phase organic compounds, semivolatile organic compounds, fine particle organic compounds, and fine particle mass. The model is applied to ambient data collected at four sites in the south coast region of California during a severe summertime photochemical smog episode, where the model determines the direct primary contributions to atmospheric pollutants from 11 distinct air pollution source types. The 11 sources included in the model are gasoline-powered motor vehicle exhaust, diesel engine exhaust, whole gasoline vapors, gasoline headspace vapors, organic solvent vapors, whole diesel fuel, paved road dust, tire wear debris, meat cooking exhaust, natural gas leakage, and vegetative detritus. Gasoline engine exhaust plus whole gasoline vapors are the predominant sources of volatile organic gases, while gasoline and diesel engine exhaust plus diesel fuel vapors dominate the emissions of semivolatile organic compounds from these sources during the episode studied at all four air monitoring sites. The atmospheric fine particle organic compound mass was composed of noticeable contributions from gasoline-powered motor vehicle exhaust, diesel engine exhaust, meat cooking, and paved road dust with smaller but quantifiable contributions from vegetative detritus and tire wear debris. In addition, secondary organic aerosol, which is formed from the low-vapor pressure products of gas-phase chemical reactions, is found to be a major source of fine particle organic compound mass under the severe photochemical smog conditions studied here. The concentrations of secondary organic aerosol calculated in the present study are compared with previous fine particle source apportionment results for less intense photochemical smog conditions. It is shown that estimated secondary organic aerosol concentrations correlate fairly well with the

  3. Stopping coal-fired electricity imports on smog days : a review of the OPA's proposed 250 MW demand response program

    International Nuclear Information System (INIS)

    Gibbons, J.

    2006-01-01

    This paper proposed an alternative to importing coal-fired electricity from the Ohio Valley on smog alert days in Ontario. It was suggested that the Ontario Power Authority (OPA) should pay large electricity consumers to shift some of their consumption from peak to off-peak hours. It was observed that demand response programs which pay consumers to shift demands to off-peak hours can provide multiple benefits to Ontario, including reduced air pollution on smog-alert days, a reduction in the spot price of electricity and reduced price volatility. In addition, demand response programs reduce the risk of blackouts and brownouts, as well as the need for new electricity generation and transmission infrastructure. It was noted that the Independent Electricity System Operator (IESO) and the OPA are planning to introduce demand response programs for the summer of 2006. However, the IESO's emergency load reduction program will be operated only during emergency situations to avoid the need for voltage reductions, while the OPA proposes to introduce a non-emergency demand response program which will be activated during most smog-alert days. Various amendments to the proposed program were suggested in this paper, including the establishment of price parity with coal-fired electricity imports; the provision of notification by 3 PM of the need for demand reductions the following day; no capping on the quantity of demand reductions that the OPA will purchase at a lower cost than electricity imports; and that the OPA's proposed Capacity Building Demand Response Program should proceed as quickly as possible without a pre-determined MW cap. 4 refs., 6 figs

  4. Radial semiconductor drift chambers

    International Nuclear Information System (INIS)

    Rawlings, K.J.

    1987-01-01

    The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

  5. Vienna Wire Chamber Conference

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    After those of 1978 and 1980, a third Wire Chamber Conference was held from 15-18 February in the Technical University of Vienna. Eight invited speakers covered the field from sophisticated applications in biology and medicine, via software, to the state of the art of gaseous detectors. In some forty other talks the speakers tackled in more detail the topics of gaseous detectors, calorimetry and associated electronics and software

  6. Wire chamber gases

    International Nuclear Information System (INIS)

    Va'vra, J.

    1992-04-01

    In this paper, we describe new developments in gas mixtures which have occurred during the last 3--4 years. In particular, we discuss new results on the measurement and modeling of electron drift parameters, the modeling of drift chamber resolution, measurements of primary ionization and the choice of gas for applications such as tracking, single electron detection, X-ray detection and visual imaging. In addition, new results are presented on photon feedback, breakdown and wire aging

  7. Double chambered right ventricle

    International Nuclear Information System (INIS)

    Cho, Chul Koo; Yu, Yun Jeong; Yeon, Kyung Mo; Han, Man Chung

    1983-01-01

    Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and autopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows: 1. Among 14 cases, 6 cases were male and 8 cases were female. Age distribution was from 4 years to 36 years. 2. In chest x-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressure chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricle was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catheterization is an essential procedure

  8. Double chambered right ventricle

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Yu, Yun Jeong; Yeon, Kyung Mo; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1983-12-15

    Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and autopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows: 1. Among 14 cases, 6 cases were male and 8 cases were female. Age distribution was from 4 years to 36 years. 2. In chest x-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressure chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricle was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catheterization is an essential procedure.

  9. Argus drift chamber

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, M; Nagovizin, V; Hasemann, H; Michel, E; Schmidt-Parzefall, W; Wurth, R; Kim, P

    1983-11-15

    The ARGUS detector came into operation at the DORIS-II e/sup +/s/sup -/ storage ring at the end of 1982. Its two meter long drift chamber contains 5940 sense and 24588 field wires organized in uniform 18x18.8 mm/sup 2/ drift cells filling the whole volume. These cells form 36 layers, 18 of which provide stereo views. Each sense wire is equipped with a single hit TDC and ADC for coordinate and dE/dx measurements. The chamber is operated with propane to improve momentum and dE/dx resolution. The drift chamber design and initial performance are presented. With a very crude space-time relation approximation and without all the necessary corrections applied a spatial resolution of about 200 ..mu..m was obtained for half of the drift cell volume. Further corrections should improve this result. An intrinsic dE/dx resolution of 4.2% and an actual resolution of 5% were obtained for cosmic muons and also for Bhabha scattered electrons. An actual dE/dx resolution of 5.6% was obtained for pions from e/sup +/e/sup -/ annihilation data with almost no track selection. A relativistic rise of 30% was observed in good agreement with theory. The long-term stability is still to be investigated.

  10. Argus target chamber

    International Nuclear Information System (INIS)

    Rienecker, F. Jr.; Glaros, S.S.; Kobierecki, M.

    1975-01-01

    A target chamber for application in the laser fusion program must satisfy some very basic requirements. (1) Provide a vacuum on the order of 10 -6 torr. (2) Support a microscopically small target in a fixed point in space and verify its location within 5 micrometers. (3) Contain an adjustable beam focusing system capable of delivering a number of laser beams onto the target simultaneously, both in time and space. (4) Provide access for diagnostics to evaluate the results of target irradiation. (5) Have flexibility to allow changes in targets, focusing optics and number of beams. The ARGUS laser which is now under construction at LLL will have a target chamber which meets these requirements in a simple economic manner. The chamber and auxiliary equipment are described, with reference to two double beam focusing systems; namely, lenses and ellipsoidal mirrors. Provision is made for future operation with four beams, using ellipsoidal mirrors for two-sided illumination and lens systems for tetragonal and tetrahedral irradiation

  11. Essere o non essere SMOG. Diventare la più giovane società di geni e deflorare il realismo socialista?

    Directory of Open Access Journals (Sweden)

    Alexandre Urussov

    2015-07-01

    Full Text Available In questo articolo Alexandre Urussov (Aleksandr o Alexander, a seconda delle diverse traslitte- razioni ricorda la propria partecipazione all’associazione giovanile underground SMOG in URSS nel 1965. Al tempo giovane scrittore moscovita, Alexandre Urussov prese parte ad alcune mani- festazioni organizzate da SMOG e pubblicò il racconto Il grido delle formiche lontane nella rivista samizdat Sfinsky. Il racconto è stato tradotto in varie lingue e pubblicato nel Regno Unito, in Italia, Germania, Francia, Canada e Islanda. L’autore spiega qui le dinamiche di alcuni processi culturali nell’URSS di quei tempi, le caratteristiche distintive del Samizdat letterario degli scrittori SMOG e gli atti di repressione delle autorità sovietiche contro gli scrittori dissidenti.

  12. Wire chambers: Trends and alternatives

    International Nuclear Information System (INIS)

    Regler, Meinhard

    1992-01-01

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

  13. Organization of bubble chamber image processing

    International Nuclear Information System (INIS)

    Gritsaenko, I.A.; Petrovykh, L.P.; Petrovykh, Yu.L.; Fenyuk, A.B.

    1985-01-01

    A programme of bubble chamber image processing is described. The programme is written in FORTRAN, it is developed for the DEC-10 computer and is designed for operation of semi-automation processing-measurement projects PUOS-2 and PUOS-4. Fornalization of the image processing permits to use it for different physical experiments

  14. Is Climate Simulation in Growth Chambers Necessary?

    Science.gov (United States)

    Z.M. Wang; K.H. Johnsen; M.J. Lechowicz

    1999-01-01

    In the expression of their genetic potential as phenotypes, trees respond to environmental cues such as photoperiod, temperature and soil and atmospheric water. However, growth chamber experiments often utilize simple and standard environmental conditions that might not provide these important environmental signals. We conducted a study to compare seedling growth in...

  15. Study of micro-strip gas ionisation chambers substrates for CMS experiment at LHC; Etude de substrats pour chambres gazeuses a micropistes dans le cadre de l`experience CMS au LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pallares, A.

    1996-06-14

    High luminosity, expected interaction and dose rates of the future LHC collider require the development of micro-strips gas chambers. In addition to optimization of this new detector, this work is concerned with understanding of gain loss phenomena. Influence of the gas substrate is carefully analysed, as well as theoretical concepts concerning glasses and their behaviour under polarization and irradiation, and the consequence on detection operations.Electron spin resonance is used to study, in standard glass, creation of radiation induced defects which may be charged. (D.L.). 14 refs.

  16. WE-EF-207-04: An Inter-Projection Sensor Fusion (IPSF) Approach to Estimate Missing Projection Signal in Synchronized Moving Grid (SMOG) System

    International Nuclear Information System (INIS)

    Zhang, H; Kong, V; Jin, J; Ren, L; Zhang, Y; Giles, W

    2015-01-01

    Purpose: A synchronized moving grid (SMOG) has been proposed to reduce scatter and lag artifacts in cone beam computed tomography (CBCT). However, information is missing in each projection because certain areas are blocked by the grid. A previous solution to this issue is acquiring 2 complimentary projections at each position, which increases scanning time. This study reports our first Result using an inter-projection sensor fusion (IPSF) method to estimate missing projection in our prototype SMOG-based CBCT system. Methods: An in-house SMOG assembling with a 1:1 grid of 3 mm gap has been installed in a CBCT benchtop. The grid moves back and forth in a 3-mm amplitude and up-to 20-Hz frequency. A control program in LabView synchronizes the grid motion with the platform rotation and x-ray firing so that the grid patterns for any two neighboring projections are complimentary. A Catphan was scanned with 360 projections. After scatter correction, the IPSF algorithm was applied to estimate missing signal for each projection using the information from the 2 neighboring projections. Feldkamp-Davis-Kress (FDK) algorithm was applied to reconstruct CBCT images. The CBCTs were compared to those reconstructed using normal projections without applying the SMOG system. Results: The SMOG-IPSF method may reduce image dose by half due to the blocked radiation by the grid. The method almost completely removed scatter related artifacts, such as the cupping artifacts. The evaluation of line pair patterns in the CatPhan suggested that the spatial resolution degradation was minimal. Conclusion: The SMOG-IPSF is promising in reducing scatter artifacts and improving image quality while reducing radiation dose

  17. WE-EF-207-04: An Inter-Projection Sensor Fusion (IPSF) Approach to Estimate Missing Projection Signal in Synchronized Moving Grid (SMOG) System

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H; Kong, V; Jin, J [Georgia Regents University Cancer Center, Augusta, GA (Georgia); Ren, L; Zhang, Y; Giles, W [Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: A synchronized moving grid (SMOG) has been proposed to reduce scatter and lag artifacts in cone beam computed tomography (CBCT). However, information is missing in each projection because certain areas are blocked by the grid. A previous solution to this issue is acquiring 2 complimentary projections at each position, which increases scanning time. This study reports our first Result using an inter-projection sensor fusion (IPSF) method to estimate missing projection in our prototype SMOG-based CBCT system. Methods: An in-house SMOG assembling with a 1:1 grid of 3 mm gap has been installed in a CBCT benchtop. The grid moves back and forth in a 3-mm amplitude and up-to 20-Hz frequency. A control program in LabView synchronizes the grid motion with the platform rotation and x-ray firing so that the grid patterns for any two neighboring projections are complimentary. A Catphan was scanned with 360 projections. After scatter correction, the IPSF algorithm was applied to estimate missing signal for each projection using the information from the 2 neighboring projections. Feldkamp-Davis-Kress (FDK) algorithm was applied to reconstruct CBCT images. The CBCTs were compared to those reconstructed using normal projections without applying the SMOG system. Results: The SMOG-IPSF method may reduce image dose by half due to the blocked radiation by the grid. The method almost completely removed scatter related artifacts, such as the cupping artifacts. The evaluation of line pair patterns in the CatPhan suggested that the spatial resolution degradation was minimal. Conclusion: The SMOG-IPSF is promising in reducing scatter artifacts and improving image quality while reducing radiation dose.

  18. Criteria for controlled atmosphere chambers

    International Nuclear Information System (INIS)

    Robinson, J.N.

    1980-03-01

    The criteria for design, construction, and operation of controlled atmosphere chambers intended for service at ORNL are presented. Classification of chambers, materials for construction, design criteria, design, controlled atmosphere chamber systems, and operating procedures are presented. ORNL Safety Manual Procedure 2.1; ORNL Health Physics Procedure Manual Appendix A-7; and Design of Viewing Windows are included in 3 appendices

  19. Accurate computer simulation of a drift chamber

    International Nuclear Information System (INIS)

    Killian, T.J.

    1980-01-01

    A general purpose program for drift chamber studies is described. First the capacitance matrix is calculated using a Green's function technique. The matrix is used in a linear-least-squares fit to choose optimal operating voltages. Next the electric field is computed, and given knowledge of gas parameters and magnetic field environment, a family of electron trajectories is determined. These are finally used to make drift distance vs time curves which may be used directly by a track reconstruction program. Results are compared with data obtained from the cylindrical chamber in the Axial Field Magnet experiment at the CERN ISR

  20. Ultra-low mass drift chambers

    International Nuclear Information System (INIS)

    Assiro, R.; Cappelli, L.; Cascella, M.; De Lorenzis, L.; Grancagnolo, F.; Ignatov, F.; L'Erario, A.; Maffezzoli, A.; Miccoli, A.; Onorato, G.; Perillo, M.; Piacentino, G.; Rella, S.; Rossetti, F.; Spedicato, M.; Tassielli, G.

    2013-01-01

    We present a novel low mass drift chamber concept, developed in order to fulfill the stringent requirements imposed by the experiments for extremely rare processes, which require high resolutions (order of 100–200 keV/c) for particle momenta in a range (50–100 MeV/c) totally dominated by the multiple scattering contribution. We describe a geometry optimization procedure and a new wiring strategy with a feed-through-less wire anchoring system developed and tested on a drift chamber prototype under completion at INFN-Lecce

  1. Ultra-low mass drift chambers

    Science.gov (United States)

    Assiro, R.; Cappelli, L.; Cascella, M.; De Lorenzis, L.; Grancagnolo, F.; Ignatov, F.; L'Erario, A.; Maffezzoli, A.; Miccoli, A.; Onorato, G.; Perillo, M.; Piacentino, G.; Rella, S.; Rossetti, F.; Spedicato, M.; Tassielli, G.; Zavarise, G.

    2013-08-01

    We present a novel low mass drift chamber concept, developed in order to fulfill the stringent requirements imposed by the experiments for extremely rare processes, which require high resolutions (order of 100-200 keV/c) for particle momenta in a range (50-100 MeV/c) totally dominated by the multiple scattering contribution. We describe a geometry optimization procedure and a new wiring strategy with a feed-through-less wire anchoring system developed and tested on a drift chamber prototype under completion at INFN-Lecce .

  2. Accurate computer simulation of a drift chamber

    CERN Document Server

    Killian, T J

    1980-01-01

    The author describes a general purpose program for drift chamber studies. First the capacitance matrix is calculated using a Green's function technique. The matrix is used in a linear-least-squares fit to choose optimal operating voltages. Next the electric field is computed, and given knowledge of gas parameters and magnetic field environment, a family of electron trajectories is determined. These are finally used to make drift distance vs time curves which may be used directly by a track reconstruction program. The results are compared with data obtained from the cylindrical chamber in the Axial Field Magnet experiment at the CERN ISR. (1 refs).

  3. On The Development of One-way Nesting of Air-pollution Model Smog Into Numerical Weather Prediction Model Eta

    Science.gov (United States)

    Halenka, T.; Bednar, J.; Brechler, J.

    The spatial distribution of air pollution on the regional scale (Bohemian region) is simulated by means of Charles University puff model SMOG. The results are used for the assessment of the concentration fields of ozone, nitrogen oxides and other ozone precursors. Current improved version of the model covers up to 16 groups of basic compounds and it is based on trajectory computation and puff interaction both by means of Gaussian diffusion mixing and chemical reactions of basic species. Gener- ally, the method used for trajectory computation is valuable mainly for episodes sim- ulation, nevertheless, climatological study can be solved as well by means of average wind rose. For the study being presented huge database of real emission sources was incorporated with all kind of sources included. Some problem with the background values of concentrations was removed. The model SMOG has been nested into the forecast model ETA to obtain appropriate meteorological data input. We can estimate air pollution characteristics both for episodes analysis and the prediction of future air quality conditions. Necessary prognostic variables from the numerical weather pre- diction model are taken for the region of the central Bohemia, where the original puff model was tested. We used mainly 850 hPa wind field for computation of prognos- tic trajectories, the influence of surface temperature as a parameter of photochemistry reactions as well as the effect of cloudness has been tested.

  4. Shock tubes: compressions in the low pressure chamber

    International Nuclear Information System (INIS)

    Schins, H.; Giuliani, S.

    1986-01-01

    The gas shock tube used in these experiments consists of a low pressure chamber and a high pressure chamber, divided by a metal-diaphragm-to-rupture. In contrast to the shock mode of operation, where incident and reflected shocks in the low pressure chamber are studied which occur within 3.5 ms, in this work the compression mode of operation was studied, whose maxima occur (in the low pressure chamber) about 9 ms after rupture. Theoretical analysis was done with the finite element computer code EURDYN-1M, where the computation was carried out to 30 ms

  5. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  6. A cylindrical drift chamber with azimuthal and axial position readout

    International Nuclear Information System (INIS)

    Bar-Yam, Z.; Cummings, J.P.; Dowd, J.P.; Eugenio, P.; Hayek, M.; Kern, W.; King, E.; Shenhav, N.; Chung, S.U.; Hackenburg, R.W.; Olchanski, C.; Weygand, D.P.; Willutzki, H.J.; Brabson, B.B.; Crittenden, R.R.; Dzierba, A.R.; Gunter, J.; Lindenbusch, R.; Rust, D.R.; Scott, E.; Smith, P.T.; Sulanke, T.; Teige, S.; Denisov, S.; Dushkin, A.; Kochetkov, V.; Lipaev, V.; Popov, A.; Shein, I.; Soldatov, A.; Anoshina, E.V.; Bodyagin, V.A.; Demianov, A.I.; Gribushin, A.M.; Kodolova, O.L.; Korotkikh, V.L.; Kostin, M.A.; Ostrovidov, A.I.; Sarycheva, L.I.; Sinev, N.B.; Vardanyan, I.N.; Yershov, A.A.; Adams, T.; Bishop, J.M.; Cason, N.M.; Sanjari, A.H.; LoSecco, J.M.; Manak, J.J.; Shephard, W.D.; Stienike, D.L.; Taegar, S.A.; Thompson, D.R.; Brown, D.S.; Pedlar, T.; Seth, K.K.; Wise, J.; Zhao, D.; Adams, G.S.; Napolitano, J.; Nozar, M.; Smith, J.A.; Witkowski, M.

    1997-01-01

    A cylindrical multiwire drift chamber with axial charge-division has been constructed and used in experiment E852 at Brookhaven National Laboratory. It serves as a trigger element and as a tracking device for recoil protons in π - p interactions. We describe the chamber's design considerations, details of its construction, electronics, and performance characteristics. (orig.)

  7. Rapid-Cycling Bubble-Chamber, details

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Parts of the hydraulic expansion system of the Rapid-Cycling Bubble-Chamber (RCBC). RCBC was the largest of 3 rapid-cycling bubble-chambers (the others were LEBC and HOLEBC), used as target- and vertex-detectors within the European Hybrid Spectrometer (EHS) in the SPS North Area (EHN1). RCBC contained 250 l of liquid hydrogen and was located inside a 3 T superconducting magnet. It was designed for 30 expansions/s (100 times faster than BEBC), the system shown here allowed 50 expansions/s. RCBC operated from 1981 to 1983 for experiments NA21, NA22 and NA23 at a rate of 15 expansions/s, clocking up a total of over 4 million. In the rear, at left, is bearded Lucien Veillet; Augustin Didona is at the right. See also 8001009. The installation of the piston assembly in the RCBC chamber body is shown in the Annual Report 1980, p.65.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  10. Chamber transport for heavy ion fusion

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2014-01-01

    A brief review is given of research on chamber transport for HIF (heavy ion fusion) dating from the first HIF Workshop in 1976 to the present. Chamber transport modes are categorized into ballistic transport modes and channel-like modes. Four major HIF reactor studies are summarized (HIBALL-II, HYLIFE-II, Prometheus-H, OSIRIS), with emphasis on the chamber transport environment. In general, many beams are used to provide the required symmetry and to permit focusing to the required small spots. Target parameters are then discussed, with a summary of the individual heavy ion beam parameters required for HIF. The beam parameters are then classified as to their line charge density and perveance, with special emphasis on the perveance limits for radial space charge spreading, for the space charge limiting current, and for the magnetic (Alfven) limiting current. The major experiments on ballistic transport (SFFE, Sabre beamlets, GAMBLE II, NTX, NDCX) are summarized, with specific reference to the axial electron trapping limit for charge neutralization. The major experiments on channel-like transport (GAMBLE II channel, GAMBLE II self-pinch, LBNL channels, GSI channels) are discussed. The status of current research on HIF chamber transport is summarized, and the value of future NDCX-II transport experiments for the future of HIF is noted

  11. Review of wire chamber aging

    International Nuclear Information System (INIS)

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  12. Stability of Streamer Chamber

    Science.gov (United States)

    Wada, Toshiaki; Ogawa, Masato; Takahashi, Kaoru; Sugiyama, Tsunetoshi; Kobayashi, Shigeharu; Kohno, Hirobumi

    1982-08-01

    The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result.

  13. Stability of streamer chamber

    International Nuclear Information System (INIS)

    Wada, Toshiaki; Ogawa, Masato; Takahashi, Kaoru; Sugiyama, Tsunetoshi; Kobayashi, Shigeharu; Kohno, Hirobumi.

    1982-01-01

    The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result. (author)

  14. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  15. Cardiac chamber scintiscanning

    International Nuclear Information System (INIS)

    Goretzki, G.

    1981-01-01

    The two methods of cardiac chamber scintiscanning, i.e. 'first pass' and 'ECG-triggered' examinations, are explained and compared. Two tables indicate the most significant radiation doses of the applied radio tracers, i.e. 99m-Tc-pertechnetate and 99m-Tc-HSA, to which a patient is exposed. These averaged values are calculated from various data given in specialised literature. On the basis of data given in literature, an effective half-life of approximately 5 hours in the intravascular space was calculated for the erythrocytes labelled with technetium 99m. On this basis, the radiation doses for the patients due to 99m-Tc-labelled erythrocytes are estimated. The advantages and disadvantages of the two methods applied for cardiac chamber scintiscanning are put into contrast and compared with the advantages and disadvantages of the quantitative X-ray cardiography of the left heart. The still existing problems connected with the assessment of ECG-triggered images are discussed in detail. The author performed investigations of his own, which concerned the above-mentioned problems. (orig./MG) [de

  16. A combination drift chamber/pad chamber for very high readout rates

    International Nuclear Information System (INIS)

    Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W.; Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J.; Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P.; Arenton, M.; Conetti, S.; Cox, B.; Dukes, E.; Golovatyuk, V.; Hanlet, P.; McManus, A.; Nelson, K.; Recagni, M.; Segal, J.; Sun, J.; Ballagh, C.; Bingham, H.; Kaeding, T.; Lys, J.; Misawa, S.; Blankman, A.; Borodin, S.; Kononenko, W.; Newcomer, M.; Selove, W.; Trojak, T.; VanBerg, R.; Zhang, S.N.; Block, M.; Corti, G.; LeCompte, T.; Rosen, J.; Yao, T.; Boden, A.; Cline, D.; Ramachandran, S.; Rhoades, J.; Tokar, S.; Budagov, J.; Tsyganov, E.; Cao, Z.L.; He, M.; Wang, C.; Wei, C.; Zhang, N.; Chen, T.Y.; Yao, N.; Clark, K.; Jenkins, M.; Cooper, M.; Creti, P.; Gorini, E.; Grancagnolo, F.; Panareo, M.; Fortney, L.; Kowald, W.; Haire, M.; Judd, D.; Turnbull, L.; Wagoner, D.; Lau, K.; Mo, G.; Trischuk, J.

    1991-11-01

    Six medium-sized (∼1 x 2 m 2 ) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers

  17. A combination drift chamber/pad chamber for very high readout rates

    Energy Technology Data Exchange (ETDEWEB)

    Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W. (Fermi National Accelerator Lab., Batavia, IL (United States)); Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J. (Wisconsin Univ., Madison, WI (United States)); Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P. (Pavia Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Rome (Italy)); Arenton, M.; Conetti, S.

    1991-11-01

    Six medium-sized ({approx}1 {times} 2 m{sup 2}) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers.

  18. Limited streamer chamber testing and quality evaluation in ASTRA

    International Nuclear Information System (INIS)

    Anzivino, G.; Bianco, S.; Casaccia, R.

    1991-01-01

    Limited streamer chambers are extensively used for high-energy and nuclear physics experiments in accelerator and underground laboratories. The tracking system of LVD, an underground experiment to study muons and nutrino astronomy, will use roughly 15000 limited streamer chambers and 100000 external pickup strips with digital readout electronics. In the article the different aspects of chamber operation that serve to establish a testing procedure and to define acceptance criteria for selecting reliable and long-life devices, are discussed. The procedures and the results obtained from a long-term test to evaluate streamer chamber quality, based upon a sample of 2900 items, are described. The selection tests and the long-term observations have been performed in the ASTRA laboratory, established at the Laboratori Nazionali di Frascati to carry out quality control procedures for streamer chambers on a large scale and in a controlled environment

  19. The CAST time projection chamber

    International Nuclear Information System (INIS)

    Autiero, D; Beltran, B; Carmona, J M; Cebrian, S; Chesi, E; Davenport, M; Delattre, M; Di Lella, L; Formenti, F; Irastorza, I G; Gomez, H; Hasinoff, M; Lakic, B; Luzon, G; Morales, J; Musa, L; Ortiz, A; Placci, A; Rodrigurez, A; Ruz, J; Villar, J A; Zioutas, K

    2007-01-01

    One of the three x-ray detectors of the CERN Axion Solar Telescope (CAST) experiment searching for solar axions is a time projection chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity x-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is set to a safe level during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62%. Shielding has been installed around the detector, lowering the background level to 4.10 x 10 -5 counts cm -2 s -1 keV -1 between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion-photon coupling and mass

  20. Assessing the meteorological conditions of a deep Italian Alpine valley system by means of a measuring campaign and simulations with two models during a summer smog episode

    NARCIS (Netherlands)

    Dosio, A.; Emeis, S.; Graziani, G.; Junkermann, W.; Levy, A.

    2001-01-01

    The typical features of a summer smog episode in the highly complex terrain of the Province of Bolzano (Northern Italy) were investigated by numerical modelling with two non-hydrostatic models, ground-based monitoring stations, and vertical profiling with two sodars and an ultra-light aircraft. High

  1. Photochemical smog effects in mixed conifer forests along a natural gradient of ozone and nitrogen deposition in the San Bernardino Mountains

    Science.gov (United States)

    Michael Arbaugh; Andrzej Bytnerowicz; Nancy Grulke; Mark Fenn; Mark Poth; Patrick Temple; Paul Miller

    2003-01-01

    Toxic effects of photochemical smog on ponderosa and Jeffrey pines in the San Bernardino Mountains were discovered in the 1950s. It was revealed that ozone is the main cause of foliar injury manifested as chlorotic mottle and premature needle senescence. Various morphological, physiological and biochemical alterations in the affected plants have been reported over a...

  2. IFE chamber technology testing program in NIF and chamber development test plan

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1995-01-01

    Issues concerning chamber technology testing program in NIF involving: criteria for evaluation/prioritization of experiments, engineering scaling requirements for test article design and material selection and R and D plan prior to NIF testing were addressed in this paper. In order to maximize the benefits of testing program in NIF, the testing in NIF should provide the experimental data relevant to DEMO design choice or to DEMO design predictive capability by utilizing engineering scaling test article designs. Test plans were developed for 2 promising chamber design concepts. Early testing in non-fusion/non-ignition prior to testing in ignition facility serves a critical role in chamber R and D test plans in order to reduce the risks and costs of the more complex experiments in NIF

  3. Diogene pictorial drift chamber

    International Nuclear Information System (INIS)

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive)

  4. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  5. Nucleation in bubble chambers

    International Nuclear Information System (INIS)

    Harigel, G.G.

    1988-01-01

    Various sources and mechanisms for bubble formation in superheated liquids are discussed. Bubble chambers can be filled with a great variety of liquids, such as e.g. the cryogenic liquids hydrogen, deuterium, neon, neon/hydrogen mixtures, argon, nitrogen, argon/nitrogen mixtures, or the warm liquids propane and various Freon like Freon-13B1. The superheated state is normally achieved by a rapid movement of an expansion piston or membrane, but can also be produced by standing ultrasonic waves, shock waves, or putting liquids under tension. Bubble formation can be initiated by ionizing particles, by intense (laser) light, or on rough surfaces. The creation of embryonic bubbles is not completely understood, but the macroscopic growth and condensation can be calculated, allowing to estimate the dynamic heat load [fr

  6. Computerized versus hand-scored health literacy tools: a comparison of Simple Measure of Gobbledygook (SMOG) and Flesch-Kincaid in printed patient education materials.

    Science.gov (United States)

    Grabeel, Kelsey Leonard; Russomanno, Jennifer; Oelschlegel, Sandy; Tester, Emily; Heidel, Robert Eric

    2018-01-01

    The research compared and contrasted hand-scoring and computerized methods of evaluating the grade level of patient education materials that are distributed at an academic medical center in east Tennessee and sought to determine if these materials adhered to the American Medical Association's (AMA's) recommended reading level of sixth grade. Librarians at an academic medical center located in the heart of Appalachian Tennessee initiated the assessment of 150 of the most used printed patient education materials. Based on the Flesch-Kincaid (F-K) scoring rubric, 2 of the 150 documents were excluded from statistical comparisons due to the absence of text (images only). Researchers assessed the remaining 148 documents using the hand-scored Simple Measure of Gobbledygook (SMOG) method and the computerized F-K grade level method. For SMOG, 3 independent reviewers hand-scored each of the 150 documents. For F-K, documents were analyzed using Microsoft Word. Reading grade levels scores were entered into a database for statistical analysis. Inter-rater reliability was calculated using intra-class correlation coefficients (ICC). Paired t -tests were used to compare readability means. Acceptable inter-rater reliability was found for SMOG (ICC=0.95). For the 148 documents assessed, SMOG produced a significantly higher mean reading grade level (M=9.6, SD=1.3) than F-K (M=6.5, SD=1.3; p SMOG method of assessment, 147 of the 148 documents (99.3%) scored above the AMA's recommended reading level of sixth grade. Computerized health literacy assessment tools, used by many national patient education material providers, might not be representative of the actual reading grade levels of patient education materials. This is problematic in regions like Appalachia because materials may not be comprehensible to the area's low-literacy patients. Medical librarians have the potential to advance their role in patient education to better serve their patient populations.

  7. The search for primary particle tracks in nucleon-nucleus interactions with gamma ray energy ΣEγ ≥ 3 TeV registered in stratospheric X-ray emulsion chambers using data of the RUNJOB experiment

    Directory of Open Access Journals (Sweden)

    Zayarnaya I.S.

    2017-01-01

    Full Text Available We present here the result of a retreatment of data from the RUNJOB (RUssia-Nippon JOint Balloon experiment of nucleon-nucleus interactions registered in stratospheric X-ray emulsion chambers (REC using a new method for searching and tracing of galactic particles in nuclear emulsions. In about halfcof these interactions (∼ 50 recorded in REC RUNJOB‘96-3B, RUNJOB‘97-6A and RUNJOB‘99-11A,B with energy released in the electromagnetic component ΣEγ ≥ 3 TeV and ΣEγ ≥ 5 TeV respectively, single charged particle tracks are not found within the search area defined individually by the particle track location accuracy. The absence of primary proton tracks is consistent with the original treatment of the RUNJOB experimental data. There is a difference in the zenith angular distribution for two groups of events in which a single charged particle track is observed or absent. The average penetration depth of the primary particles in REC to the interaction vertex in the zenith angle range from 60∘ to 79∘ differs by a factor two for these groups.

  8. 'Electric smog' - non-ionizing electromagnetic fields and radiation. Seminar of the Zentrale Informationsstelle, Umweltberatung Bayern. Vol. 1

    International Nuclear Information System (INIS)

    Haury, H.J.; Koller, U.

    1993-06-01

    This seminar on the subject of ''electrical smog'' welcomed participants from Bavarian environmental consultancy agencies, rural and urban district authorities, ministries, consume-consultancy agencies and public health authorities. Leading scientists from research and authorities gave papers on the sources, exposure and effects/actions of electromagnetic fields and present the current state of knowledge about the hazards and risk of this radiation for human health. The proceedings in hand provide the papers given on the following topics: electromagnetic fields - and introduction to relevant issues; low-frequency fields - sources and exposure; high-frequency fields - sources and exposure; biological actions and effects of low-frequency fields; biological actions and effects of high-frequency fields; low-frequency fields -helath risk assessment; high-frequency fields - health risk assessment. (Uhe) [de

  9. Performance of the Drift Chambers of the CMS Experiment in the Measurement of LHC Muons; Prestaciones de las Camaras de Deriva del Experimento CMS en la Deteccion de Muones del LHC

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, D.; Fouz, M. C.

    2011-05-13

    This work deals with the study of the performance of the drift chambers of the CMS Barrel Muon detector operating at the LHC. Using the data obtained with pp collisions during the first months os LHC operation we have studied the drift cell efficiency and position resolution, as well as the effect of the existing background noise. The results confirm the excellent performance of the muon chambers. It is expected that it will improve further as statistics increase, thus allowing a correct calibration and alignment of these chambers. (Author) 6 refs.

  10. Drift chambers in BM@N Experiment

    Directory of Open Access Journals (Sweden)

    Fedorišin Ján

    2017-01-01

    In first step, the radius vs drift time calibration curve is estimated and applied to calculate DCH hit closest approach coordinates. These coordinates are used to construct hits in each DCH under the assumption of track linearity. Hits in both the DCHs are subsequently aligned and fitted to produce global linear track candidates. Eventually the hit and track reconstruction is optimized by the autocalibration method. The coordinate resolutions are estimated from Gaussian fits of the DCH hit residual spectra for different DCH planes. Furthermore, the deuteron beam momentum value is reconstructed in order to check reliability of the employed track reconstruction algorithm.

  11. Expanding exports, increasing smog : Ontario Power Generation's and Hydro One's strategies to continue coal-fired electricity generation in Ontario

    International Nuclear Information System (INIS)

    Gibbons, J.

    2002-06-01

    The production of coal-fired electricity increased by approximately 150 per cent in Ontario between 1995 and 2000. As a result, the smog-causing emissions generated by the five coal-fired power plants operated by Ontario Power Generation caused an increase in smog and worsened air quality in the province as well as affecting air quality as far afield as the Atlantic provinces. Between 2002 and 2005, it is expected that the Pickering and Bruce nuclear plants will be returned to service, making the electricity generated by the coal plants surplus to Ontario's needs. Increasing this surplus are the planned natural gas generating stations. Ontario Power Generation is planning on using this surplus to export it to the United States rather than phasing out its reliance on coal. The increase in exports to the United States Northeast and Midwest is planned with Hydro One, already busy increasing its transmission capacity to the United States by 1,000 megawatt (MW). This plan involves laying 975 MW submarine cable from the Nanticoke Generating Station (operated by Ontario Power Generation) under Lake Erie to Pennsylvania, Ohio, or both states. At the moment, the exports are constrained by the government emissions limits imposed by the Ontario government on sulphur dioxide and nitrogen oxides. This constraint could be removed if Ontario Power Generation decides to pay further for pollution controls for sulphur dioxide and nitrogen oxides at its coal stations. Unfortunately, increasing the exports would also result in emissions increases for 28 other uncapped pollutants such as lead, mercury and arsenic. The author recommended that the Ontario government ban non-emergency coal-fired electricity exports to improve air quality in the province. refs., 8 figs

  12. Wire chambers with their magnetostrictive readout

    CERN Multimedia

    1974-01-01

    This set of wire chamber planes shaped as a cylinder sector was installed inside the magnet of a polarized spin target modified to allow as well momentum analysis of the produced particles. The experiment (S126) was set up by the CERN-Trieste Collaboration in the PS beam m9 to measure spin effects in the associated production of of a positive kaon and a positive Sigma by interaction of a positive pion with polarized protons.

  13. Study on the effect factor of the absolute fission rates measured by depleted uranium fission chamber

    International Nuclear Information System (INIS)

    Jiang Li; Liu Rong; Wang Dalun; Wang Mei; Lin Jufang; Wen Zhongwei

    2003-01-01

    The absolute fission rates was measured by the depleted uranium fission chamber. The efficiency of the fission fragments recorded in the fission chamber was analyzed. The factor influencing absolute fission rates was studied in the experiment, including the disturbing effect between detectors and the effect of the structural of the fission chamber, etc

  14. Charge division in a small proportional chamber constructed with aluminized mylar tubes

    International Nuclear Information System (INIS)

    Biino, C.; Mussa, R.; Palestini, S.; Pastrone, N.; Pesando, L.

    1988-01-01

    A tracking detector composed of aluminized mylar drift tubes is under development for the Fermilab experiment 760. A prototype chamber has been constructed. Results on the longitudinal coordinate determined by charge division are given. Spatial resolution values below 2 mm (rms) were found, corresponding to <1% of the chamber length. Results on chamber ageing are also discussed. (orig.)

  15. Charge division in a small proportional chamber constructed with aluminized mylar tubes

    Science.gov (United States)

    Biino, C.; Mussa, R.; Palestini, S.; Pastrone, N.; Pesando, L.

    1988-09-01

    A tracking detector composed of aluminized mylar drift tubes is under development for the Fermilab experiment 760. A prototype chamber has been constructed. Results on the longitudinal coordinate determined by charge division are given. Spatial resolution values below 2 mm (rms) were found, corresponding to <1% of the chamber length. Results on chamber ageing are also discussed.

  16. National Ignition Facility Target Chamber

    International Nuclear Information System (INIS)

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

    2000-01-01

    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 two 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

  17. He leak testing of Indus-2 dipole vacuum chambers

    International Nuclear Information System (INIS)

    Sindal, B.K.; Bhavsar, S.T.; Shukla, S.K.

    2003-01-01

    Full text: Centre for Advanced Technology is developing its second synchrotron radiation source INDUS-2 which is a 2.5 GeV electron storage ring. Dipole vacuum chambers are the vital components of Indus-2 vacuum system. Each of these chambers is approx. 3.6 m long and 0.67 m wide with 24 nos. of ports of various sizes. The dipole chambers were made by machining two halves and they are then lip welded together. The dipole chamber has approx. 14 m of total weld length and it was leak tested for leak tightness of the order of 10 -10 mbar 1/s. Helium mass spectrometer leak detector (HMSLD) was utilized for the leak testing. Subsequently the leaks of various orders in welding joints were repaired and leak tightness achieved. This paper describes the experiences during leak testing of 20 nos. of aluminum dipole chambers for INDUS-2

  18. The CLEO III drift chamber

    CERN Document Server

    Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

    2002-01-01

    The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

  19. Beam test results of a resistive plate chamber made of Chinese bakelites

    CERN Document Server

    Ying, J; Ban, Y; Liu Hong Tao; Zhu, Z M; Zhu, Z Y; Chen, T; Ma Jing Guo; Qian, S J

    2001-01-01

    The detailed beam test results of the first Chinese made avalanche mode resistive plate chamber are reported. The experimental set-ups at CERN GIF area are introduced. The detection efficiency, position resolution and time resolution of the chamber fulfil requirements as muon trigger for the future LHC experiments, while the rate capability is not good enough if the chamber is used at forward region. The applicability and the further possible improvements of the chamber are discussed. (12 refs).

  20. Coffee Tables & Cryo Chambers

    DEFF Research Database (Denmark)

    Temte, Bjørn; Schoenau-Fog, Henrik

    2012-01-01

    This paper explores how the user experience and diegetic time changes when a specific roleplaying scenario is played via a virtual environment and headsets, compared to a traditional playthrough. A case-study roleplaying scenario is developed to investigate the change in user experience qualitati...

  1. Micro plate fission chamber development

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Jiang Li; Liu Rong; Wang Dalun

    2014-01-01

    To conduct the measurement of neutron flux and the fission rate distribution at several position in assemblies, the micro plate fission chamber was designed and fabricated. Since the requirement of smaller volume and less structure material was taken into consideration, it is convinient, commercial and practical to use fission chamber to measure neutron flux in specific condition. In this paper, the structure of fission chamber and process of fabrication were introduced and performance test result was presented. The detection efficiency is 91.7%. (authors)

  2. High counting rate resistive-plate chamber

    International Nuclear Information System (INIS)

    Peskov, V.; Anderson, D.F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast ( 5 counts/mm 2 . A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity (≥10 10 Ω·cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm 2 , leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases

  3. "Flat-Fish" vacuum chamber for the ISR

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    The "Flat-Fish" vacuum chamber was a very special one for the ISR beam intersection I-4, inside the Split-Field Magnet. Technical descriptions are given with pictures 7802042 and 7712182. There were several generations of this chamber. This picture was taken during the last year of ISR operation. See also 7510230X, 7511123X, 7802039, 7802041. A flat-fish type vacuum chamber was also used at I-8, inside the Open Axial Field Magnet (OAFM, experiment 807 on large transverse momentum collision products), see 7901358.

  4. A shielding chamber for the Rossendorf whole body counter

    International Nuclear Information System (INIS)

    Beutmann, A.; Ebert, S.; Kaden, M.; Loehnert, D.; Doerfel, H.R.; Schreiber, W.; Helbig, S.

    2016-01-01

    In connection with the relocation of the incorporation measurement point operated by the VKTA, a new shielding chamber was designed. The development of the new shielding chamber will be shown based on the design study by IDEA System and the inquiries for material availability, procurement of material and assembly technology up to fabrication, assembly and completion of the chamber. The accompanying background measurements through In-situ gamma spectrometry and first experiences with incorporation measurements at the new In-Vivo measurement facility are shown.

  5. Temperature uniformity in the CERN CLOUD chamber

    Directory of Open Access Journals (Sweden)

    A. Dias

    2017-12-01

    Full Text Available The CLOUD (Cosmics Leaving OUtdoor Droplets experiment at CERN (European Council for Nuclear Research investigates the nucleation and growth of aerosol particles under atmospheric conditions and their activation into cloud droplets. A key feature of the CLOUD experiment is precise control of the experimental parameters. Temperature uniformity and stability in the chamber are important since many of the processes under study are sensitive to temperature and also to contaminants that can be released from the stainless steel walls by upward temperature fluctuations. The air enclosed within the 26 m3 CLOUD chamber is equipped with several arrays (strings of high precision, fast-response thermometers to measure its temperature. Here we present a study of the air temperature uniformity inside the CLOUD chamber under various experimental conditions. Measurements were performed under calibration conditions and run conditions, which are distinguished by the flow rate of fresh air and trace gases entering the chamber at 20 and up to 210 L min−1, respectively. During steady-state calibration runs between −70 and +20 °C, the air temperature uniformity is better than ±0.06 °C in the radial direction and ±0.1 °C in the vertical direction. Larger non-uniformities are present during experimental runs, depending on the temperature control of the make-up air and trace gases (since some trace gases require elevated temperatures until injection into the chamber. The temperature stability is ±0.04 °C over periods of several hours during either calibration or steady-state run conditions. During rapid adiabatic expansions to activate cloud droplets and ice particles, the chamber walls are up to 10 °C warmer than the enclosed air. This results in temperature differences of ±1.5 °C in the vertical direction and ±1 °C in the horizontal direction, while the air returns to its equilibrium temperature with a time constant of about 200 s.

  6. Large-format, high-speed, X-ray pnCCDs combined with electron and ion imaging spectrometers in a multipurpose chamber for experiments at 4th generation light sources

    International Nuclear Information System (INIS)

    Strueder, Lothar; Epp, Sascha; Rolles, Daniel; Hartmann, Robert; Holl, Peter; Lutz, Gerhard; Soltau, Heike; Eckart, Rouven; Reich, Christian; Heinzinger, Klaus; Thamm, Christian; Rudenko, Artem; Krasniqi, Faton; Kuehnel, Kai-Uwe; Bauer, Christian; Schroeter, Claus-Dieter; Moshammer, Robert; Techert, Simone; Miessner, Danilo; Porro, Matteo

    2010-01-01

    Fourth generation accelerator-based light sources, such as VUV and X-ray Free Electron Lasers (FEL), deliver ultra-brilliant (∼10 12 -10 13 photons per bunch) coherent radiation in femtosecond (∼10-100 fs) pulses and, thus, require novel focal plane instrumentation in order to fully exploit their unique capabilities. As an additional challenge for detection devices, existing (FLASH, Hamburg) and future FELs (LCLS, Menlo Park; SCSS, Hyogo and the European XFEL, Hamburg) cover a broad range of photon energies from the EUV to the X-ray regime with significantly different bandwidths and pulse structures reaching up to MHz micro-bunch repetition rates. Moreover, hundreds up to trillions of fragment particles, ions, electrons or scattered photons can emerge when a single light flash impinges on matter with intensities up to 10 22 W/cm 2 . In order to meet these challenges, the Max Planck Advanced Study Group (ASG) within the Center for Free Electron Laser Science (CFEL) has designed the CFEL-ASG MultiPurpose (CAMP) chamber. It is equipped with specially developed photon and charged particle detection devices dedicated to cover large solid-angles. A variety of different targets are supported, such as atomic, (aligned) molecular and cluster jets, particle injectors for bio-samples or fixed target arrangements. CAMP houses 4π solid-angle ion and electron momentum imaging spectrometers ('reaction microscope', REMI, or 'velocity map imaging', VMI) in a unique combination with novel, large-area, broadband (50 eV-25 keV), high-dynamic-range, single-photon-counting and imaging X-ray detectors based on the pnCCDs. This instrumentation allows a new class of coherent diffraction experiments in which both electron and ion emission from the target may be simultaneously monitored. This permits the investigation of dynamic processes in this new regime of ultra-intense, high-energy radiation-matter interaction. After an introduction into the salient features of the CAMP chamber and

  7. Proton beam monitor chamber calibration

    International Nuclear Information System (INIS)

    Gomà, C; Meer, D; Safai, S; Lorentini, S

    2014-01-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

  8. A small flat fission chamber

    International Nuclear Information System (INIS)

    Li Yijun; Wang Dalun; Chen Suhe

    1999-01-01

    With fission materials of depleted uranium, natural uranium, enriched uranium, 239 Pu, and 237 Np, the authors have designed and made a series of small flat fission chamber. The authors narrated the construction of the fission chamber and its technological process of manufacture, and furthermore, the authors have measured and discussed the follow correct factor, self-absorption, boundary effect, threshold loss factor, bottom scatter and or so

  9. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  10. PEP quark search proportional chambers

    Energy Technology Data Exchange (ETDEWEB)

    Parker, S I; Harris, F; Karliner, I; Yount, D [Hawaii Univ., Honolulu (USA); Ely, R; Hamilton, R; Pun, T [California Univ., Berkeley (USA). Lawrence Berkeley Lab.; Guryn, W; Miller, D; Fries, R [Northwestern Univ., Evanston, IL (USA)

    1981-04-01

    Proportional chambers are used in the PEP Free Quark Search to identify and remove possible background sources such as particles traversing the edges of counters, to permit geometric corrections to the dE/dx and TOF information from the scintillator and Cerenkov counters, and to look for possible high cross section quarks. The present beam pipe has a thickness of 0.007 interaction lengths (lambdasub(i)) and is followed in both arms each with 45/sup 0/ <= theta <= 135/sup 0/, ..delta..phi=90/sup 0/ by 5 proportional chambers, each 0.0008 lambdasub(i) thick with 32 channels of pulse height readout, and by 3 thin scintillator planes, each 0.003 lambdasub(i) thick. Following this thin front end, each arm of the detector has 8 layers of scintillator (one with scintillating light pipes) interspersed with 4 proportional chambers and a layer of lucite Cerenkov counters. Both the calculated ion statistics and measurements using He-CH/sub 4/ gas in a test chamber indicate that the chamber efficiencies should be >98% for q=1/3. The Landau spread measured in the test was equal to that observed for normal q=1 traversals. One scintillator plane and thin chamber in each arm will have an extra set of ADC's with a wide gate bracketing the normal one so timing errors and tails of earlier pulses should not produce fake quarks.

  11. Chemical Composition Based Aerosol Optical Properties According to Size Distribution and Mixture Types during Smog and Asian Dust Events in Seoul, Korea

    Science.gov (United States)

    Jung, Chang Hoon; Lee, Ji Yi; Um, Junshik; Lee, Seung Soo; Kim, Yong Pyo

    2018-02-01

    This study investigated the optical properties of aerosols involved in different meteorological events, including smog and Asian dust days. Carbonaceous components and inorganic species were measured in Seoul, Korea between 25 and 31 March 2012. Based on the measurements, the optical properties of aerosols were calculated by considering composition, size distribution, and mixing state of aerosols. To represent polydisperse size distributions of aerosols, a lognormal size distribution with a wide range of geometric mean diameters and geometric standard deviations was used. For the optical property calculations, the Mie theory was used to compute single-scattering properties of aerosol particles with varying size and composition. Analysis of the sampled data showed that the water-soluble components of organic matter increased on smog days, whereas crustal elements increased on dust days. The water content significantly influenced the optical properties of aerosols during the smog days as a result of high relative humidity and an increase in the water-soluble component. The absorption coefficients depended on the aerosol mixture type and the aerosol size distributions. Therefore, to improve our knowledge on radiative impacts of aerosols, especially the regional impacts of aerosols in East Asia, accurate measurements of aerosols, such as size distribution, composition, and mixture type, under different meteorological conditions are required.

  12. R607 drift chamber

    CERN Multimedia

    1977-01-01

    The experiment R607 was set-up by the Aachen-Amsterdam (NIKHEF)-CERN-Munich- Northwestern-Riverside Collaborartion to search for diffraction production of charmed particles and correlations at high longitudinal momentum. It consisted of identical septum magnet spectrometers on both downstream arms of intersection 6, each having a series of three gas Cerenkov counters for particle identification. (see also photo 7702599X)

  13. Aging of plumes from emission sources based on chamber simulation

    Science.gov (United States)

    Wang, X.; Deng, W.; Fang, Z.; Bernard, F.; Zhang, Y.; Yu, J.; Mellouki, A.; George, C.

    2017-12-01

    Study on atmospheric aging of plumes from emission sources is essential to understand their contribution to both secondary and primary pollutants occurring in the ambient air. Here we directly introduced vehicle exhaust, biomass burning plume, industrial solvents and cooking plumes into a smog chamber with 30 m3 fluorinated ethylene propylene (FEP) Teflon film reactor housed in a temperature-controlled enclosure, for characterizing primarily emitted air pollutants and for investigating secondarily formed products during photo-oxidation. Moreover, we also initiated study on the formation of secondary aerosols when gasoline vehicle exhaust is mixed with typical coal combustion pollutant SO2 or typical agricultural-related pollutant NH3. Formation of secondary organic aerosols (SOA) from typical solvent toluene was also investigated in ambient air matrix in comparison with purified air matrix. Main findings include: 1) Except for exhaust from idling gasoline vehicles, traditional precursor volatile organic compounds could only explain a very small fraction of SOA formed from vehicle exhaust, biomass burning or cooking plumes, suggesting knowledge gap in SOA precursors; 2) There is the need to re-think vehicle emission standards with a combined primary and/or secondary contribution of vehicle exhaust to PM2.5 or other secondary pollutants such as ozone; 3) When mixed with SO2, the gasoline vehicle exhaust revealed an increase of SOA production factor by 60-200% and meanwhile SO2 oxidation rates increased about a factor of 2.7; when the aged gasoline vehicle exhaust were mixing with NH3, both particle number and mass concentrations were increasing explosively. These phenomenons implied the complex interaction during aging of co-existing source emissions. 4) For typical combination of "tolune+SO2+NOx", when compared to chamber simulation with purified air as matrix, both SOA formation and SO2 oxidation were greatly enhanced under ambient air matrix, and the enhancement

  14. Effect of photochemical smog associated with synoptic weather patterns on cardiovascular and respiratory hospital admissions in metropolitan Taipei.

    Science.gov (United States)

    Lai, Li-Wei

    2012-01-01

    This study focuses on the relationship between photochemical smog (PS) (hourly ozone conc. >100 ppb), PS-related diseases, and the synoptic weather patterns during 2005-2009 in metropolitan Taipei. The results show that compared to respiratory ailments (ICD code 460-519) and asthma (ICD code 493), cardiovascular ailments (ICD code 390-459) were more clearly influenced by PS events. On the PS event day, the number of admissions of babies, children, and adults increased by 0.04 [95% CI 0.01-0.06], 0.03 [95% CI 0.00-0.07], and 1.12 [95% CI 0.36-1.89] (P < 0.05), respectively. The investigation showed that more than 70% of the PS events were associated primarily with the peripheral circulation of typhoons, Pacific pressure, and discrete Pacific pressure. PS events are a threat to public health. To avoid the ill effects of air pollution, residents should be informed about the daily weather patterns and air quality.

  15. Inhalable microorganisms in Beijing's PM2.5 and PM10 pollutants during a severe smog event.

    Science.gov (United States)

    Cao, Chen; Jiang, Wenjun; Wang, Buying; Fang, Jianhuo; Lang, Jidong; Tian, Geng; Jiang, Jingkun; Zhu, Ting F

    2014-01-01

    Particulate matter (PM) air pollution poses a formidable public health threat to the city of Beijing. Among the various hazards of PM pollutants, microorganisms in PM2.5 and PM10 are thought to be responsible for various allergies and for the spread of respiratory diseases. While the physical and chemical properties of PM pollutants have been extensively studied, much less is known about the inhalable microorganisms. Most existing data on airborne microbial communities using 16S or 18S rRNA gene sequencing to categorize bacteria or fungi into the family or genus levels do not provide information on their allergenic and pathogenic potentials. Here we employed metagenomic methods to analyze the microbial composition of Beijing's PM pollutants during a severe January smog event. We show that with sufficient sequencing depth, airborne microbes including bacteria, archaea, fungi, and dsDNA viruses can be identified at the species level. Our results suggested that the majority of the inhalable microorganisms were soil-associated and nonpathogenic to human. Nevertheless, the sequences of several respiratory microbial allergens and pathogens were identified and their relative abundance appeared to have increased with increased concentrations of PM pollution. Our findings may serve as an important reference for environmental scientists, health workers, and city planners.

  16. Inhalable Microorganisms in Beijing’s PM2.5 and PM10 Pollutants during a Severe Smog Event

    Science.gov (United States)

    2014-01-01

    Particulate matter (PM) air pollution poses a formidable public health threat to the city of Beijing. Among the various hazards of PM pollutants, microorganisms in PM2.5 and PM10 are thought to be responsible for various allergies and for the spread of respiratory diseases. While the physical and chemical properties of PM pollutants have been extensively studied, much less is known about the inhalable microorganisms. Most existing data on airborne microbial communities using 16S or 18S rRNA gene sequencing to categorize bacteria or fungi into the family or genus levels do not provide information on their allergenic and pathogenic potentials. Here we employed metagenomic methods to analyze the microbial composition of Beijing’s PM pollutants during a severe January smog event. We show that with sufficient sequencing depth, airborne microbes including bacteria, archaea, fungi, and dsDNA viruses can be identified at the species level. Our results suggested that the majority of the inhalable microorganisms were soil-associated and nonpathogenic to human. Nevertheless, the sequences of several respiratory microbial allergens and pathogens were identified and their relative abundance appeared to have increased with increased concentrations of PM pollution. Our findings may serve as an important reference for environmental scientists, health workers, and city planners. PMID:24456276

  17. Testing fireproof materials in a combustion chamber

    Directory of Open Access Journals (Sweden)

    Kulhavy Petr

    2017-01-01

    Full Text Available This article deals with a prototype concept, real experiment and numerical simulation of a combustion chamber, designed for testing fire resistance some new insulating composite materials. This concept of a device used for testing various materials, providing possibility of monitoring temperatures during controlled gas combustion. As a fuel for the combustion process propane butane mixture has been used and also several kinds of burners with various conditions of inlet air (forced, free and fuel flows were tested. The tested samples were layered sandwich materials based on various materials or foams, used as fillers in fire shutters. The temperature distribution was measured by using thermocouples. A simulation of whole concept of experimental chamber has been carried out as the non-premixed combustion process in the commercial final volume sw Pyrosim. The result was to design chamber with a construction suitable, according to the international standards, achieve the required values (temperature in time. Model of the combustion based on a stoichiometric defined mixture of gas and the tested layered samples showed good conformity with experimental results – i.e. thermal distribution inside and heat release rate that has gone through the sample.

  18. Directional muon jet chamber for a muon collider (Groovy Chamber)

    International Nuclear Information System (INIS)

    Atac, M.

    1996-10-01

    A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-ψ coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas

  19. Study on time response properties of ionization chamber in profile gauge

    International Nuclear Information System (INIS)

    Wang Zhentao; Shen Yixiong; Wang Liqiang; Hao Pengfei

    2011-01-01

    The drift time of ions in the ionization chamber was measured by means of using a shortly pulsed X-ray device and through analyzing the voltage signals on the load resistor of the chamber recorded by a digital oscilloscope. By using this method, the time response properties of the ionization chamber in the profile gauge were studied, results of ion drift time for ionization chambers with different internal structures, different voltages and different gas pressures were introduced and the sources of error were discussed. The experiment results show that the time response of ionization chamber in profile gauge meets the requirement of on-line hot strip measuring. (authors)

  20. A Lab Assembled Microcontroller-Based Sensor Module for Continuous Oxygen Measurement in Portable Hypoxia Chambers

    OpenAIRE

    Mathupala, Saroj P.; Kiousis, Sam; Szerlip, Nicholas J.

    2016-01-01

    Background Hypoxia-based cell culture experiments are routine and essential components of in vitro cancer research. Most laboratories use low-cost portable modular chambers to achieve hypoxic conditions for cell cultures, where the sealed chambers are purged with a gas mixture of preset O2 concentration. Studies are conducted under the assumption that hypoxia remains unaltered throughout the 48 to 72 hour duration of such experiments. Since these chambers lack any sensor or detection system t...

  1. Plasma chemistry in wire chambers

    International Nuclear Information System (INIS)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55 Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  2. Experimental project - Cloud chamber

    International Nuclear Information System (INIS)

    Nour, Elena; Quinchard, Gregory; Soudon, Paul

    2015-01-01

    This document reports an academic experimental project dealing with the general concepts of radioactivity and their application to the cloud room experiment. The author first recalls the history of the design and development of a cloud room, and some definitions and characteristics of cosmic radiation, and proposes a description of the principle and physics of a cloud room. The second part is a theoretical one, and addresses the involved particles, the origins of electrons, and issues related to the transfer of energy (Bremsstrahlung effect, Bragg peak). The third part reports the experimental work with the assessment of a cloud droplet radius, the identification of a trace for each particle (alphas and electrons), and the study of the magnetic field deviation

  3. Oxford engineering students to study new solutions for vacuum chambers

    CERN Multimedia

    Department of Engineering Science - University of Oxford

    2012-01-01

    In April, eleven engineering science students in their third year at Oxford University were invited here to present their design ideas for new vacuum chamber materials to be used in accelerators. We publish below an abstract of the article that the University of Oxford featured on its website.   The 11 Oxford students who worked at CERN on alternatives to beryllium in vacuum chambers. (Photo courtesy of the Department of Engineering Science, University of Oxford.) Engineering Science students invited to design for CERN’s Large Hadron Collider In April, eleven Engineering Science students in their third year were invited to the CERN laboratory in Geneva to present their ideas for new vacuum chamber designs for the experiments of the Large Hadron Collider (LHC). Their design objectives were to propose alternatives to beryllium – the material used for some of the existing experimental vacuum chambers. Beryllium (chemical element with the symbol Be and atomic number 4) is to...

  4. Mini-chamber, an advanced protection concept for NIF

    International Nuclear Information System (INIS)

    Peterson, P.F.; Scott, J.M.

    1996-01-01

    Inertial confinement fusion (ICF) target debris and ablated near-target materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in future inertial fusion energy (IFE) power plants. This work discusses a NIF 'mini-chamber,' designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protected target positioner and refractory first-wall coatings, the mini-chamber provides important flexibility in three areas: debris-shield protection from beyond-design basis shots (i.e. heavy hohlraums, special diagnostics, shields); fielding of large experiments with significant surface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. Key mini-chamber modeling results are presented, followed by discussion of equipment requirements for fielding a NIF mini-chamber. 7 refs., 3 figs

  5. Fabrication of resistive plate chamber using bakelite

    International Nuclear Information System (INIS)

    Neog, Himangshu; Bhuyan, M.R.; Biswas, S.; Mohanty, B.; Mohanty, Rudranarayan; Rudra, Sharmili; Sahu, P.K.; Sahu, S.

    2014-01-01

    Now a days Resistive Plate Chamber (RPC) is one of the most important detectors in the High Energy Physics (HEP) experiments. RPC is a gas filled detector utilizing a constant and uniform electric field produced between two parallel electrode plates made of a material with high bulk resistivity e.g. glass or bakelite. RPC has good time resolution (1-2 ns) and spatial resolution (∼ cm). The high resistance of RPC plate limits the spark size produced after the ionization of gas due to the passing charged particle. This contribution discusses building of a RPC using bakelite (local sources) and the measurement of the surface resistivity of the detector

  6. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  7. An experimental propane bubble chamber

    International Nuclear Information System (INIS)

    Rogozinski, A.

    1957-01-01

    Describes a propane bubble chamber 10 cm in diameter and 5 cm deep. The body of the chamber is in stainless steel, and it has two windows of polished hardened glass. The compression and decompression of the propane are performed either through a piston in direct contact with the liquid, or by the action on the liquid, through a triple-mylar-Perbunan membrane, of a compressed gas. The general and also optimum working conditions of the chamber are described, and a few results are given concerning, in particular, the tests of the breakage-resistance of the windows and the measurements of the thermal expansion of the compressibility isotherm for the propane employed. (author) [fr

  8. Equipment for handling ionization chamber

    International Nuclear Information System (INIS)

    Altmann, J.

    1988-01-01

    The device consists of an ionization channel with an ionization chamber, of a support ring, axial and radial bearings, a sleeve, a screw gear and an electric motor. The ionization chamber is freely placed on the bottom of the ionization channel. The bottom part of the channel deviates from the vertical axis. The support ring propped against the axial bearing in the sleeve is firmly fixed to the top part of the ionization channel. The sleeve is fixed to the reactor lid. Its bottom part is provided with a recess for the radial bearing which is propped against a screw wheel firmly connected to the ionization channel. In measuring neutron flux, the screw wheel is rotated by the motor, thus rotating the whole ionization channel such that the ionization chamber is displaced into the reactor core.(J.B.). 1 fig

  9. General purpose nuclear irradiation chamber

    International Nuclear Information System (INIS)

    Nurul Fadzlin Hasbullah; Nuurul Iffah Che Omar; Nahrul Khair Alang Md Rashid; Jaafar Abdullah

    2013-01-01

    Nuclear technology has found a great need for use in medicine, industry, and research. Smoke detectors in our homes, medical treatments and new varieties of plants by irradiating its seeds are just a few examples of the benefits of nuclear technology. Portable neutron source such as Californium-252, available at Industrial Technology Division (BTI/ PAT), Malaysian Nuclear Agency, has a 2.645 year half-life. However, 252 Cf is known to emit gamma radiation from the source. Thus, this chamber aims to provide a proper gamma shielding for samples to distinguish the use of mixed neutron with gamma-rays or pure neutron radiation. The chamber is compatible to be used with other portable neutron sources such as 241 Am-Be as well as the reactor TRIGA PUSPATI for higher neutron dose. This chamber was designed through a collaborative effort of Kulliyyah Engineering, IIUM with the Industrial Technology Division (BTI) team, Malaysian Nuclear Agency. (Author)

  10. Test chamber for alpha spectrometry

    Science.gov (United States)

    Larsen, Robert P.

    1977-01-01

    Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

  11. The knife-edge chamber

    International Nuclear Information System (INIS)

    Barasch, E.F.; Bowcock, T.J.V.; Drew, M.M.; Elliott, S.M.; Lee, B.; McIntyre, P.M.; Pang, Y.; Popovic, M.; Smith, D.D.

    1990-01-01

    In this paper the design for a new technology for particle track detectors is described. Using standard IC fabrication techniques, a pattern of microscopic knife edges and field-shaping electrodes can be fabricated on a silicon substrate. The knife-edge chamber uniquely offers attractive performance for the track chambers required for SSC detectors, for which no present technology is yet satisfactory. Its features include: excellent radiation hardness (10 Mrad), excellent spatial resolution (∼20 μm), short drift time (20 ns), and large pulse height (1 mV)

  12. Ionization chambers for LET determination

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    2010-01-01

    resolution and high sensitivity are necessary. For exact dosimetry which is done using ionization chambers (ICs), the recombination taking place in the IC has to be known. Up to now, recombination is corrected phenomenologically and more practical approaches are currently used. Nevertheless, Jaff´e's theory...... of columnar recombination was designed to model the detector efficiency of an ionization chamber. Here, we have shown that despite the approximations and simplification made, the theory is correct for the LETs typically found in clinical radiotherapy employing particles from protons to carbon ions...

  13. The Mark III vertex chamber

    International Nuclear Information System (INIS)

    Adler, J.; Bolton, T.; Bunnell, K.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 μm at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 μm using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin

  14. Effects of puerarin combined with edaravone on inhalation lung injury induced by black gunpowder smog in rats

    Directory of Open Access Journals (Sweden)

    Zheng-guan WANG

    2015-04-01

    Full Text Available Objective To explore the protective effects of puerarin combined with edaravone on inhalation lung injury induced by black gunpowder smog in rats. Methods Forty healthy male Wistar rats were randomly divided into normal control group (group N, inhalation group (group X, puerarin group (group P, edaravone group (group E and edaravone combined with puerarin group (group L, with 8 rats in each group. Rat model of inhalation lung injury was reproduced by a self-made smoke generator. Rats in group E were given intraperitoneal injections of edaravone (9 mg/kg at 30 minutes and 1 day after modeling (twice totally. Rats in group P were given intraperitoneal injections of puerarin (100 mg/kg at 30 minutes and 1, 2, 3, 4, 5 days after modeling (6 times totally. Rats in group L were treated the way of both group E and P. The rats in group N and group X were given intraperitoneal injections of normal saline (12 ml/kg at the time-points above. The animals were sacrificed 6 days after modeling, and the blood samples were collected from abdominal aorta to assess arterial blood gas values, meanwhile the serum levels of tumor necrosis factor-α (TNF-α, interleukin-6 (IL-6, interleukin-10 (IL-10 were determined by ELISA. Lung tissue homogenates were prepared to determine the protein content and myeloperoxidase (MPO activity. The pathological changes in the lung tissue with HE staining were observed under light microscope. Results Arterial blood gas analysis revealed that the PaO2 levels in groups P, E and L were higher than that in group X (P<0.05, and the PaO2 levels in groups E and L were higher than that in group P (P<0.05, while the PaCO2 level in group L was lower than that in groups X and E (P<0.05. The TNF-α, IL-6 and IL-10 levels in serum, the protein content and MPO activity in lung tissue homogenate in groups P, E and L were lower than those of group X (P<0.05. The TNF-α and IL-6 levels in serum and protein content and MPO activity in lung

  15. DNA bulky adducts in a Mediterranean population correlate with environmental ozone concentration, an indicator of photochemical smog.

    Science.gov (United States)

    Palli, Domenico; Saieva, Calogero; Grechi, Daniele; Masala, Giovanna; Zanna, Ines; Barbaro, Antongiulio; Decarli, Adriano; Munnia, Armelle; Peluso, Marco

    2004-03-01

    Ozone (O(3)), the major oxidant component in photochemical smog, mostly derives from photolysis of nitrogen dioxide. O(3) may have biologic effects directly and/or via free radicals reacting with other primary pollutants and has been reported to influence daily mortality and to increase lung cancer risk. Although DNA damage may be caused by ozone itself, only other photochemical reaction products (as oxidised polycyclic aromatic hydrocarbons) may form bulky DNA adducts, a reliable biomarker of genotoxic damage and cancer risk, showing a seasonal trend. In a large series consisting of 320 residents in the metropolitan area of Florence, Italy, enrolled in a prospective study for the period 1993-1998 (206 randomly sampled volunteers, 114 traffic-exposed workers), we investigated the correlation between individual levels of DNA bulky adducts and a cumulative O(3) exposure score. The average O(3) concentrations were calculated for different time windows (0-5 to 0-90 days) prior to blood drawing for each participant, based on daily measurements provided by the local monitoring system. Significant correlations between DNA adduct levels and O3 cumulative exposure scores in the last 2-8 weeks before enrollment emerged in never smokers. Correlations were highest in the subgroup of never smokers residing in the urban area and not occupationally exposed to vehicle traffic pollution, with peak values for average concentrations 4-6 weeks before enrollment (r = 0.34). Our current findings indicate that DNA adduct formation may be modulated by individual characteristics and by the cumulative exposure to environmental levels of ozone in the last 4-6 weeks, possibly through ozone-associated reactive pollutants. Copyright 2003 Wiley-Liss, Inc.

  16. Construction of a full-length prototype of the BESIII drift chamber and on-detector test for the BESIII drift chamber electronics

    International Nuclear Information System (INIS)

    Qin Zhonghua; Wu Linghui; Liu Jianbei; Chinese Academy of Sciences, Beijing; Yan Zhikang; Hunan Univ., Changsha; Chen Yuanbo; Chen Chang; Xu Meihang; Wang Lan; Ma Xiaoyan; Jin Yan; Liu Rongguang; Tang Xiao; Zhang Guifang; Zhu Qiming; Sheng Huayi; Zhu Kejun

    2007-01-01

    A full-length prototype of the BESIII drift chamber was built. The experience gained on gas sealing, high voltage supply and front-end electronics installation should be greatly beneficial to the successful construction of the BESIII drift chamber. An on-detector test of the BESIII drift chamber electronics was carried out with the constructed prototype chamber. The noise performance, drift time and charge measurements, and electronics gains were examined specifically. The final test results indicate that the electronics have a good performance and can satisfy their design requirements. (authors)

  17. Testing an hydrogen streamer chamber

    CERN Multimedia

    1975-01-01

    A 2x10 cm gap streamer chamber, 35x55 cm2 in surface, was built and tested at CERN. Good tracks of cosmic rays were obtained up to atmospheric pressure, see F. Rohrbach et al, CERN-LAL (Orsay) Collaboration, Nucl. Instr. Methods 141 (1977) 229. Michel Cathenoz stand on the center.

  18. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  19. Analysis of an interaction experiment of 12GeV/c of antiprotons in hydrogen in the big European bubble chamber (B.E.B.C.). Study of the problems concerning the efficiency of the frame automatic measurement apparatus (C.R.T.) of this chamber

    International Nuclear Information System (INIS)

    Obolensky, M.

    1979-01-01

    B.E.B.C. (Big European Bubble Chambers) filled with hydrogen is submitted to a 12 GeV/c beam of antiprotons. The frames are analysed on a machine, called C.R.T. - Paris, using the light ray created on the screen of a Cathode Ray Tube. The topic of the study is the program, called 'tracking follower', which tries to ensure the most automatic pattern recognition of tracks of charged particles, by means of local approximation hypothesis (circle, parabola), having the constant possibility of calling the operator. We show that the accuracy of this measure on a semi-automatic machine is compatible with this of manual measurement tables, i.e. in the order of ten microns or less. Preliminary results, obtained for the first two hundred events analysed on the C.R.T.-Paris are presented at the end [fr

  20. A test and calibration setup for mass-produced proportional chambers

    International Nuclear Information System (INIS)

    Burov, S.; Galaktionov, Yu.; Kamyshkov, Yu.

    1987-01-01

    The L3 experiment, presently being installed at (CERN) will use a 300 Hadron Calorimeter made of depleted uranium plates interleaved with about 8.000 proportional chambers. The review of experience in the use of gamma radioactivity of depleted uranium for the test of the chambers which are now being built at ITEP is given. The depleted uranium radioactivity and the response of a proportional chamber are discussed. A description of the test setup is given and a method to test the uniformity of the chamber response is discussed. Finally, a procedure for the L3 hadron calorimeter calibration in situ using uranium radioactivity is proposed