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Sample records for norte ozone study

  1. Ozone studies in the Paso del Norte region

    Science.gov (United States)

    Becerra-Davila, Fernando

    The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment. The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are conducive to high ozone episodes. In addition, the planetary boundary height is studied to understand its impact on high ozone episodes. Several studies report that ground level ozone non-attainment regulations could be caused not only by local emissions, but also by atmospheric transport. In this work the atmospheric advection of pollutants into the region is analyzed using HYSPLIT backward trajectories. Furthermore, a novel backward trajectory clustering technique is implemented for the summer of 2006. The "ozone weekend effect" (OWE) is a phenomenon by which in some geographical regions ambient ozone concentrations tend to be higher on weekends than on weekdays, despite the lower emissions of ozone precursors during those days. The observed local OWE has never previously been studied in terms of the photolysis rates of four of the main ozone precursors. In this research a novel method that allows the calculation of actinic fluxes, photolysis frequencies and photolysis rates with a high degree of accuracy and reliability has been developed. This method utilizes a combination of the experimental data available for this region in conjunction with a radiative transfer model (TUV model). Three weekend-weekday cases during summers 2006, 2009 and 2010 are studied in this work. In this research, the photolysis impact on the local OWE is studied. The results

  2. Sensitivity modeling study for an ozone occurrence during the 1996 Paso Del Norte Ozone Campaign.

    Science.gov (United States)

    Lu, Duanjun; Reddy, Remata S; Fitzgerald, Rosa; Stockwell, William R; Williams, Quinton L; Tchounwou, Paul B

    2008-12-01

    Surface ozone pollution has been a persistent environmental problem in the US and Europe as well as the developing countries. A key prerequisite to find effective alternatives to meeting an ozone air quality standard is to understand the importance of local anthropogenic emissions, the significance of biogenic emissions, and the contribution of long-range transport. In this study, an air quality modeling system that includes chemistry and transport, CMAQ, an emission processing model, SMOKE, and a mesoscale numerical meteorological model, WRF, has been applied to investigate an ozone event occurring during the period of the 1996 Paso del Norte Ozone Campaign. The results show that the modeling system exhibits the capability to simulate this high ozone occurrence by providing a comparable temporal variation of surface ozone concentration at one station and to capture the spatial evolution of the event. Several sensitivity tests were also conducted to identify the contributions to high surface ozone concentration from eight VOC subspecies, biogenic VOCs, anthropogenic VOCs and long-range transportation of ozone and its precursors. It is found that the reductions of ETH, ISOP, PAR, OLE and FORM help to mitigate the surface ozone concentration, and like anthropogenic VOCs, biogenic VOC plays a nonnegligible role in ozone formation. But for this case, long-range transport of ozone and its precursors appears to produce an insignificant contribution.

  3. Sensitivity Modeling Study for an Ozone Occurrence during the 1996 Paso Del Norte Ozone Campaign

    Directory of Open Access Journals (Sweden)

    Duanjun Lu

    2008-11-01

    Full Text Available Surface ozone pollution has been a persistent environmental problem in the US and Europe as well as the developing countries. A key prerequisite to find effective alternatives to meeting an ozone air quality standard is to understand the importance of local anthropogenic emissions, the significance of biogenic emissions, and the contribution of long-range transport. In this study, an air quality modeling system that includes chemistry and transport, CMAQ, an emission processing model, SMOKE, and a mesoscale numerical meteorological model, WRF, has been applied to investigate an ozone event occurring during the period of the 1996 Paso del Norte Ozone Campaign. The results show that the modeling system exhibits the capability to simulate this high ozone occurrence by providing a comparable temporal variation of surface ozone concentration at one station and to capture the spatial evolution of the event. Several sensitivity tests were also conducted to identify the contributions to high surface ozone concentration from eight VOC subspecies, biogenic VOCs, anthropogenic VOCs and long-range transportation of ozone and its precursors. It is found that the reductions of ETH, ISOP, PAR, OLE and FORM help to mitigate the surface ozone concentration, and like anthropogenic VOCs, biogenic VOC plays a nonnegligible role in ozone formation. But for this case, long-range transport of ozone and its precursors appears to produce an insignificant contribution.

  4. ATMOSPHERIC VOLATILE ORGANIC COMPOUND MEASUREMENTS DURING THE 1996 PASO DEL NORTE OZONE STUDY

    Science.gov (United States)

    Ambient air VOC samples were collected at surface air quality monitoring sites, near sources of interest, and aloft on the US (El Paso) and Mexican (Ciudad Juarez) side of the border during a six-week period of the 1996 Paso del Norte Ozone Study. Samples were collected at five...

  5. Meteorological Simulations of Ozone Episode Case Days during the 1996 Paso del Norte Ozone Study

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.J.; Costigan, K.; Muller, C.; Wang, G.

    1999-02-01

    Meteorological simulations centered around the border cities of El Paso and Ciudad Juarez have been performed during an ozone episode that occurred on Aug. 13,1996 during the 1996 Paso del Norte Ozone Study field campaign. Simulations were petiormed using the HOTMAC mesoscale meteorological model using a 1,2,4, and 8 km horizontal grid size nested mesh system. Investigation of the vertical structure and evolution of the atmospheric boundary layer for the Aug. 11-13 time period is emphasized in this paper. Comparison of model-produced wind speed profiles to rawirisonde and radar profiler measurements shows reasonable agreement. A persistent upper-level jet was captured in the model simulations through data assimilation. In the evening hours, the model was not able to produce the strong wind direction shear seen in the radar wind profiles. Based on virtual potential temperature profile comparisons, the model appears to correctly simulate the daytime growth of the convective mixed layer. However, the model underestimates the cooling of the surface layer at night. We found that the upper-level jet significantly impacted the turbulence structure of the boundary layer, leading to relatively high turbulent kinetic energy (tke) values aloft at night. The model indicates that these high tke values aloft enhance the mid-morning growth of the boundary layer. No upper-level turbulence measurements were available to verify this finding, however. Radar profiler-derived mixing heights do indicate relatively rapid morning growth of the mixed layer.

  6. Sensitivity Modeling Study for an Ozone Occurrence during the 1996 Paso Del Norte Ozone Campaign

    OpenAIRE

    Duanjun Lu; Remata S. Reddy; Williams, Quinton L.; Rosa Fitzgerald; William R. Stockwell; Paul B. Tchounwou

    2008-01-01

    Surface ozone pollution has been a persistent environmental problem in the US and Europe as well as the developing countries. A key prerequisite to find effective alternatives to meeting an ozone air quality standard is to understand the importance of local anthropogenic emissions, the significance of biogenic emissions, and the contribution of long-range transport. In this study, an air quality modeling system that includes chemistry and transport, CMAQ, an emission processing model, SMOKE, ...

  7. The Influence of Photolysis Rate Constants in Ozone Production for the Paso del Norte Region

    Science.gov (United States)

    Becerra, Fernando; Fitzgerald, Rosa

    2012-03-01

    In this research work we are focusing on understanding the relationship between photolysis rates and the photochemical ozone changes observed in the Paso del Norte region. The city of El Paso, Texas together with Ciudad Juarez, Mexico, forms the largest contiguous bi-national metropolitan area. This region suffers year-round ozone pollution events, and a better understanding is needed to mitigate them. Previous studies have found that ambient ozone concentrations tend to be higher on weekends rather than on weekdays, this phenomenon being referred to, as the ``weekend effect.'' If the ozone standard is exceeded more frequently on weekends, then this phenomenon must be considered in the design of ozone control strategies. In this work we investigate some of the most representative weekend ozone episodes at El Paso, TX, during the years 2009, 2010 and 2011 using the ozone photolysis rates. In this research the TUV radiative-transfer model is used to calculate the local photolysis rates and a UV MFRSR instrument is used to obtain experimental parameters. Seasonal variations and the weekday-weekend effect is studied. The results of this research will help to understand the underlying behavior of the photolysis rate constants when different atmospheric conditions are present.

  8. Evaluation of emission control strategies to reduce ozone pollution in the Paso del Norte region using a photochemical air quality modeling system

    Science.gov (United States)

    Valenzuela, Victor Hugo

    variability of the PREDICTED to OBSERVED ozone concentrations of both BASELINE model and simulations with modified emissions assessed by the sensitivity analysis. All simulations were found to vary within acceptable ranges of these two criteria variables. Simulation results indicate ozone formation in the PdN region is VOC-limited. Under VOC-limited conditions, modifications to NOx emissions do not produce a marked increase or decrease in ozone concentrations. Modifications to VOC emissions generated the highest variability in ozone concentrations. Increasing VOC emissions by 75% produced results which minimized model bias and error when comparing PREDICTED and OBSERVED ozone concentrations. Increasing VOC emissions by 75% either alone or in combination with a 75% increase in NOx emissions generated PREDICTED ozone concentrations very near to OBSERVED ozone. By evaluating the changes in ambient ozone concentrations through photochemical modeling, air quality planners may identify the most efficient or effective VOC emissions control strategies for area sources. Among the strategies to achieve emissions reductions are installation of gasoline vapor recovery systems, replacing high-pressure low-volume surface coating paint spray guns with high-volume low-pressure spray paint guns, requiring emissions control booths for surface coating operations as well as undertaking solvent management practices, requiring the sale of low VOC paint solvents in the surface-coating industry, and requiring low-VOC solvents in the dry cleaning industry. Other strategies to reduce VOC emissions include initiating Eco-Driving strategies to reduce fuel consumption from mobile sources and minimize vehicle idling at the international ports of entry by reducing bridge wait times. This dissertation depicts a tool for evaluating impacts of emissions on regional air quality by addressing the highly unresolved fugitive emissions in the Paso del Norte region. It provides a protocol for decision makers to

  9. Experimental studies on ozonation of ethylenethiourea

    Institute of Scientific and Technical Information of China (English)

    Xinyu Dong; Junwang Meng; Bo Yang; Yang Zhang; Jie Gan; Xi Shu; Jinian Shu

    2011-01-01

    The experimental study on ozonation of ethylenethiourea (ETU) is conducted. The reaction of gas-phase ETU with 0.63 × l06 mol/L ozone is carried out in a 200-L reaction chamber. The secondary organic aerosol (SOA) resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size (SMPS). The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days. The ozonation of dry ETU particles, ETU-contained water droplets and ETU aqueous solution is investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUVATOFMS). The formation of 2-imidazoline is observed in the ozonation of dry ETU particles and ETU-contained water droplets. The formation of 2-imidazoline and ethylenerea is observed in the ozonation of ETU aqueous solution.

  10. Ozone Lidar Observations for Air Quality Studies

    Science.gov (United States)

    Wang, Lihua; Newchurch, Mike; Kuang, Shi; Burris, John F.; Huang, Guanyu; Pour-Biazar, Arastoo; Koshak, William; Follette-Cook, Melanie B.; Pickering, Kenneth E.; McGee, Thomas J.; Sullivan, John T.; Langford, Andrew O.; Senff, Christoph J.; Alvarez, Raul; Eloranta, Edwin

    2015-01-01

    Tropospheric ozone lidars are well suited to measuring the high spatio-temporal variability of this important trace gas. Furthermore, lidar measurements in conjunction with balloon soundings, aircraft, and satellite observations provide substantial information about a variety of atmospheric chemical and physical processes. Examples of processes elucidated by ozone-lidar measurements are presented, and modeling studies using WRF-Chem, RAQMS, and DALES/LES models illustrate our current understanding and shortcomings of these processes.

  11. A study on the effects of ozone dosage on dissolved-ozone flotation (DOF) process performance.

    Science.gov (United States)

    Jin, Xin; Jin, Pengkang; Wang, Xiaochang

    2015-01-01

    Dissolved-ozone flotation (DOF) is a tertiary wastewater treatment process, which combines ozonation and flotation. In this paper, a pilot-scale DOF system fed by secondary effluent from a wastewater treatment plant (WWTP) in China was used to study the effect of ozone dosage on the DOF process performance. The results show that an ozone dosage could affect the DOF performance to a large extent in terms of color and organic matter removal as well as disinfection performance. The optimal color and organic matter removal was achieved at an ozone dosage of 0.8 mg/l. For disinfection, significant improvement in performance could be achieved only when the organic matter removal was optimal. The optimal ozone dosage of at least 1.6 mg/l was put forward, in this case, in order to achieve the optimal color, turbidity, organic matter and disinfection performance.

  12. Estudios de series temporales de energía solar UV-B de 305 nm y espesor de la capa de ozono estratosférico en Arica, norte de Chile Study of time series for 305 nm solar energy UV-B and stratospheric ozone layer thickness Arica in the north of Chile

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    Miguel Rivas

    2011-08-01

    Full Text Available En este trabajo se muestran los resultados del análisis de las series temporales de la energía solar medida a nivel del suelo, en la banda de 305 nm, y el espesor de la capa de ozono estratosférico. El rasgo más importante es la independencia de los valores de energía a nivel del suelo respecto de la variabilidad de corto periodo de la capa de ozono, siendo probablemente efectos meteorológicos locales los que llevan el mayor peso de la varianza.In this paper, the results obtained by analyzing time series of ground level energy of the solar radiation in the 305 nm band and stratospheric ozone layer thickness are shown. The most relevant feature found is the independence of the variability of the ground level energy with respect to the short period variations of the ozone layer, being the meteorological local effects those which more heavily affect the variability.

  13. Comparative Study of Ozonation and Catalyzed Ozonation Processes for Drinking Water Treatment by Pilot Test

    Institute of Scientific and Technical Information of China (English)

    GUAN Chun-yu; MA Jun; SHI Feng-hua; ZHANG Xiao-lan

    2009-01-01

    The ozone consumption effect and organic removal ability of metal coated cordierite ceramic honeycombs catalytic ozonation (catazone) process and ozonation process were comparatively studied by pilot-scale experiments. By Scan Electron Microscope (SEM), Atomic Force Microscope (AFM), BET, and X-ray photoelectron spectroscopy (XPS) analysis, metal oxides attached to ceramic surface were found to be in the form of crystal cluster, and the pore structure of ceramics was less developed. The air flow statuses of vacant catazone and ozone contactors were inclined to be plug-flow and mixed flow, respectively. Comparing with ozonation process, the ozone mass transfer efficiency of catazone process is lower, and the ozone decomposition efficiency of catazone is higher. The former effect is more obvious in semi-batch experiment, and the latter effect is more obvious in continuous-flow experiment. Unsaturated organics removal efficiencies of the two oxidation processes are similar, and are less affected by dissolved ozone concentration when it is higher than 1 mg/L. More dissolved organics were detected in catazone process in continuous-flow reaction, and more CH3Cl3formation potential (CH3Cl3FP) was removed by catazone in semi-batch mode, especially in the water with lower UV254.

  14. Study of ozone "weekend effect" in Shanghai

    Institute of Scientific and Technical Information of China (English)

    TANG WenYuan; ZHAO ChunSheng; GENG FuHai; PENG Li; ZHOU GuangQiang; GAO Wei; XU JianMing; TIE XueXi

    2008-01-01

    Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O3) concentrations in Xujiahui are higher at weekends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOX), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays.The possible chemical cause of ozone "weekend effect" is that NO2/NO ratio increases at weekends by 25.61% compared with those on weekdays.In addition, because of an average 12.13% reduction in NOx (NO + NO2) in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate.The rate of ozone production is a function of VOCs and NOx in the atmosphere.VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the "NOx-limited".The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone "weekend effect" in Xujiahui.Furthermore, combining with MICAPS cloud amount data, the fact that ozone "weekend effect" in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone "weekend effect" in Xujiahui of Shanghai.

  15. Ozone Removal by Filters Containing Activated Carbon: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William; Spears, Mike; Sullivan, Douglas; Mendell, Mark

    2009-09-01

    This study evaluated the ozone removal performance of moderate-cost particle filters containing activated carbon when installed in a commercial building heating, ventilating, and air conditioning (HVAC) system. Filters containing 300 g of activated carbon per 0.09 m2 of filter face area were installed in two 'experimental' filter banks within an office building located in Sacramento, CA. The ozone removal performance of the filters was assessed through periodic measurements of ozone concentrations in the air upstream and downstream of the filters. Ozone concentrations were also measured upstream and downstream of a 'reference' filter bank containing filters without any activated carbon. The filter banks with prefilters containing activated carbon were removing 60percent to 70percent of the ozone 67 and 81 days after filter installation. In contrast, there was negligible ozone removal by the reference filter bank without activated carbon.

  16. Ozone Therapy for Tumor Oxygenation: a Pilot Study

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    Bernardino Clavo

    2004-01-01

    Full Text Available Tumor hypoxia is an adverse factor for chemotherapy and radiotherapy. Ozone therapy is a non-conventional form of medicine that has been used successfully in the treatment of ischemic disorders. This prospective study was designed to assess the effect of ozone therapy on tumor oxygenation. Eighteen subjects were recruited for the study. Systemic ozone therapy was administered by autohemotransfusion on three alternate days over one week. Tumor oxygenation levels were measured using polarographic needle probes before and after the first and the third ozone therapy session. Overall, no statistically significant change was observed in the tumor oxygenation in the 18 patients. However, a significant decrease was observed in hypoxic values ≤10 and ≤5 mmHg of pO2. When individually assessed, a significant and inverse non-linear correlation was observed between increase in oxygenation and the initial tumor pO2 values at each measuring time-point, thus indicating that the more poorly-oxygenated tumors benefited most (rho = −0.725; P = 0.001. Additionally, the effect of ozone therapy was found to be lower in patients with higher hemoglobin concentrations (rho = −0.531; P < 0.034. Despite being administered over a very short period, ozone therapy improved oxygenation in the most hypoxic tumors. Ozone therapy as adjuvant in chemo-radiotherapy warrants further research.

  17. Compilation and evaluation of a Paso del Norte emission inventory

    Energy Technology Data Exchange (ETDEWEB)

    Funk, T.H.; Chinkin, L.R.; Roberts, P.T. [Sonoma Technology, Inc., 1360 Redwood Way, Suite C, 94954-1169 Petaluma, CA (United States); Saeger, M.; Mulligan, S. [Pacific Environmental Services, 5001 S. Miami Blvd., Suite 300, 27709 Research Triangle Park, NC (United States); Paramo Figueroa, V.H. [Instituto Nacional de Ecologia, Avenue Revolucion 1425, Nivel 10, Col. Tlacopac San Angel, Delegacion Alvaro Obregon, C.P., 01040, D.F. Mexico (Mexico); Yarbrough, J. [US Environmental Protection Agency - Region 6, 1445 Ross Avenue, Suite 1200, 75202-2733 Dallas, TX (United States)

    2001-08-10

    Emission inventories of ozone precursors are routinely used as input to comprehensive photochemical air quality models. Photochemical model performance and the development of effective control strategies rely on the accuracy and representativeness of an underlying emission inventory. This paper describes the tasks undertaken to compile and evaluate an ozone precursor emission inventory for the El Paso/Ciudad Juarez/Southern Dona Ana region. Point, area and mobile source emission data were obtained from local government agencies and were spatially and temporally allocated to a gridded domain using region-specific demographic and land-cover information. The inventory was then processed using the US Environmental Protection Agency (EPA) recommended Emissions Preprocessor System 2.0 (UAM-EPS 2.0) which generates emissions files compatible with the Urban Airshed Model (UAM). A top-down evaluation of the emission inventory was performed to examine how well the inventory represented ambient pollutant compositions. The top-down evaluation methodology employed in this study compares emission inventory ratios of non-methane hydrocarbon (NMHC)/nitrogen oxide (NO{sub x}) and carbon monoxide (CO)/NO{sub x} ratios to corresponding ambient ratios. Detailed NMHC species comparisons were made in order to investigate the relative composition of individual hydrocarbon species in the emission inventory and in the ambient data. The emission inventory compiled during this effort has since been used to model ozone in the Paso del Norte airshed (Emery et al., CAMx modeling of ozone and carbon monoxide in the Paso del Norte airshed. In: Proc of Ninety-Third Annual Meeting of Air and Waste Management Association, 18-22 June 2000, Air and Waste Management Association, Pittsburgh, PA, 2000)

  18. Stratospheric contribution to surface ozone in the desert Southwest during the 2013 Las Vegas Ozone Study

    Science.gov (United States)

    Langford, A. O.; Senff, C. J.; Alvarez, R. J. _II, II; Brioude, J. F.; Cooper, O. R.; Holloway, J. S.; Lin, M.; Marchbanks, R.; Pierce, R. B.; Reddy, P. J.; Sandberg, S.; Weickmann, A. M.; Williams, E. J.; Gustin, M. S.; Iraci, L. T.; Leblanc, T.; Yates, E. L.

    2014-12-01

    The 2013 Las Vegas Ozone Study (LVOS) was designed to investigate the potential impact of stratosphere-troposphere transport (STT) and long-range transport of pollution from Asia on surface O3 concentrations in Clark County, NV. This measurement campaign, which took place in May and June of 2013, was conducted at Angel Peak, NV, a high elevation site about 2.8 km above mean sea level and 45 km west of Las Vegas. The study was organized around the NOAA ESRL truck-based TOPAZ scanning ozone lidar with collocated in situ sampling of O3, CO, and meteorological parameters. These measurements were supported by the NOAA/NESDIS real time modelling system (RAQMS), FLEXPART particle dispersion model, and the NOAA GFDL AM3 model. In this talk, I will describe one of several STT events that occurred during the LVOS campaign. This intrusion, which was profiled by TOPAZ on the night of May 24-25, was also sampled by the NASA Alpha Jet, the Table Mountain ozone lidar, and by an ozonesonde flying above southern California. This event also led to significant ozone increases at surface monitors operated by Clark County, the California Air Resources Board, the U.S. National Park Service, and the Nevada Rural Ozone Initiative (NRVOI), and resulted in exceedances of the 2008 75 ppbv O3 NAAQS both in Clark County and in surrounding areas of Nevada and southern California. The potential implications of this and similar events for air quality compliance in the western U.S. will be discussed.

  19. A climatological study of rural surface ozone in central Greece

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    P. D. Kalabokas

    2004-01-01

    Full Text Available Recent studies show that surface ozone levels at rural sites in Greece are generally high when compared with rural ozone measurements at northern European sites. The area of SE Europe, including Greece, is not very well monitored regarding rural ozone in comparison to central and northern Europe. In order to have the best possible picture of the rural surface ozone climatology in the area, based on the available data-sets of long-term continuous monitoring stations, the 10-year measurement records (1987-1996 of the Athens peripheral station of Liossia, (12 km N of the city center and the urban background station of Geoponiki (3 km W as well as the 4-year record (1996-1999 of the rural station of Aliartos (100 km NW of Athens, are analyzed in this paper. The data for Liossia and Geoponiki stations are screened for cases of strong airflow from rural areas (N-NE winds stronger than 5 m/s. The variation characteristics of the average rural ozone afternoon levels (12:00-18:00, with the best vertical atmospheric mixing, are mainly examined since these measurements are expected to be representative of the broader area. In all three stations there is a characteristic seasonal variation of rural ozone concentrations with lowest winter afternoon values at about 50 μg/m3 in December-January and average summer afternoon values at about 120 μg/m3 in July-August, indicating that high summer values are observed all over the area. The rural summer afternoon ozone values are very well correlated between the three stations, implying spatial homogeneity all over the area but also temporal homogeneity, since during the 13-year period 1987-1999 the rural afternoon ozone levels remained almost constant around the value of 120 μg/m3.

  20. Modified Team-Based Learning Strategy to Improve Human Anatomy Learning: A Pilot Study at the Universidad Del Norte in Barranquilla, Colombia

    Science.gov (United States)

    Martínez, Emilio G.; Tuesca, Rafael

    2014-01-01

    As part of an institutional program sponsored by the Centre for Teaching Excellence at the Universidad del Norte, Barranquilla, Colombia, we developed an educational research study on two sessions of human anatomy in which we combined team-based learning (TBL) and the use of iPads. Study data included the TBL, assessments applied during the…

  1. Modified Team-Based Learning Strategy to Improve Human Anatomy Learning: A Pilot Study at the Universidad Del Norte in Barranquilla, Colombia

    Science.gov (United States)

    Martínez, Emilio G.; Tuesca, Rafael

    2014-01-01

    As part of an institutional program sponsored by the Centre for Teaching Excellence at the Universidad del Norte, Barranquilla, Colombia, we developed an educational research study on two sessions of human anatomy in which we combined team-based learning (TBL) and the use of iPads. Study data included the TBL, assessments applied during the…

  2. Kinetic study of ozonation of molasses fermentation wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Coca, M. [Departamento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Prado de la Magdalena s/n, 47011 Valladolid (Spain)], E-mail: monica@iq.uva.es; Pena, M.; Gonzalez, G. [Departamento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Prado de la Magdalena s/n, 47011 Valladolid (Spain)

    2007-10-22

    A kinetic study of molasses wastewater ozonation was carried out in a stirred tank reactor to obtain the rate constants for the decolorization reaction and the regime through which ozone is absorbed. First, fundamental mass transfer parameters such as ozone solubility, volumetric mass transfer coefficients and ozone decomposition kinetics were determined from semi-batch experiments in organic-free solutions with an ionic composition similar that of industrial wastewater. The influence of operating variables such as the stirring rate and gas flow rate on the kinetic and mass transfer parameters was also studied. The application of film theory allows to establish that the reactions between ozone and colored compounds in wastewater take place in the fast and pseudo-first-order regime, within the liquid film. The decolorization rate constants were evaluated at pH 8.7 and 25 deg. C, varying from 0.6 x 10{sup 7} to 3.8 x 10{sup 7} L mol{sup -1} s{sup -1}, depending on the stirring rate and the inlet gas flow.

  3. Study on coinfecting vector-borne pathogens in dogs and ticks in Rio Grande do Norte, Brazil

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    Luiz Ricardo Gonçalves

    Full Text Available Since dogs presenting several vector borne diseases can show none or nonspecific clinical signs depending on the phase of infection, the assessment of the particular agents involved is mandatory. The present study aimed to investigate the presence of Babesia spp., Ehrlichia spp., Anaplasma spp., Hepatozoon spp. and Leishmania spp. in blood samples and ticks, collected from two dogs from Rio Grande do Norte showing suggestive tick-borne disease by using molecular techniques. DNA of E. canis, H. canis and L. infantum were detected in blood samples and R. sanguineus ticks collected from dogs. Among all samples analyzed, two showed the presence of multiple infections with E. canis, H. canis and L. infantum chagasi. Here we highlighted the need for molecular differential diagnosis in dogs showing nonspecific clinical signs.

  4. Ozone therapy on Otorhinolaryngology. A five-year study.

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    Armando Figueroa Hernández

    2005-11-01

    Full Text Available Fundament: The ample active spectre of ozone in medicine is based in a series of properties that positively influence certain metabolic processes, whose alterations are cause for many diseases. Methods: Prospective-descriptive study about the treatment with ozone, besides the conventional therapeutics, to patients bearing affections of possible vascular ethiology as acufenos, peripheral vertiginous syndrome, sudden hypacusia, and others of infectious origin as recurrent suppurated half chronic otitis, rebel to conventional therapeutics. Tran rectal bias was used during three weeks, the results and evolution of patients were controlled. Results: ozone treatment effectiveness was proved (91%, with no intoxication or intolerance, a rapid remission of vertigo was observed in nearly all patients since first sessions, and evident betterment or remission of acufenos and the hypacusia. 

  5. Ozone formation and transport in southeastern United States: Overview of the SOS Nashville/Middle Tennessee Ozone Study

    Science.gov (United States)

    Meagher, James F.; Cowling, Ellis B.; Fehsenfeld, Fred C.; Parkhurst, William J.

    1998-09-01

    The Southern Oxidants Study (SOS) is a public-private partnership collectively engaged, since 1989, in a coordinated program of policy-relevant research to improve scientific and public understanding of tropospheric ozone pollution. In the summers of 1994 and 1995, SOS implemented the Nashville/Middle Tennessee Ozone Study. This effort, the second SOS urban intensive study, conducted a series of integrated, process-oriented airborne and surface measurement experiments to better understand the chemistry and meteorology associated with the production, transport, and impact of tropospheric ozone. Specific technical objectives addressed (1) the role of biogenic VOC and NOx emissions on local and regional ozone production, (2) the effect of urban-rural exchange/interchange on local and regional ozone production, (3) sub-grid-scale photochemical and meteorological processes, and (4) the provision of a high-quality chemical and meteorological data set to test and improve observation- and emission-based air quality forecast models. Some of the more significant findings of the 1994-1995 studies include the following: (1) Ozone production in Nashville was found to be close to the transition between NOx-sensitive and VOC-sensitive chemistry. (2) Ozone production efficiency (OPE) in power plant plumes, molecules of ozone formed per molecule of NOx emitted, was found to be inversely proportion to NOx emission rate, with the plants having the greatest NOx emissions exhibiting the lowest OPE. (3) During stagnant conditions, nighttime winds dominated pollutant transport and represent the major mechanism for transporting urban pollutants to rural areas. Ultimately, results provided by this research will allow improved assessment of existing ozone management strategies and provide better scientific tools for the development of future management strategies.

  6. TOLNet - A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Science.gov (United States)

    Newchurch, Michael J.; Kuang, Shi; Wang, Lihua; LeBlanc, Thierry; Alvarez II, Raul J.; Langford, Andrew O.; Senff, Christoph J.; Brown, Steve; Johnson, Bryan; Burris, John F.; hide

    2015-01-01

    NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly time-resolved (few minutes) tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation.

  7. Comparative study of ceramic blocks for masonry produced in Paraiba and Rio Grande do Norte; Estudo comparativo de blocos ceramicos para alvenaria produzidos na Paraiba e no Rio Grande do Norte (Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.C. dos; Melo, O.B. de; Macedo, R.S. de; Silva, B.J. da; Goncalves, W.P.; Santana, L.N.L., E-mail: renato.materiais@gmail.com [Universidade Federal de Campina Grande (CCT/UAEMa/UFCG), Campina Grande, PB (Brazil). Unidade Acadamica de Engenharia de Materiais. Centro de Ciencias e Tecnologia

    2011-07-01

    The aim of this study to analyze the properties of ceramic blocks produced by the states of Paraiba and Rio Grande do Norte. For this, the raw materials used in the fabrication of these blocks were characterized using the techniques of chemical, granulometry and mineralogical analysis and determination of the plasticity index of mixture ceramic. The properties of the ceramic blocks were determined by evaluating the geometric and visual characteristics and determining the water absorption and compressive strength, according to technical recommendations ABNT NBR 15270. It can be observed that samples have chemical compositions with a predominance of SiO{sub 2} and Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} and they are composed of mica, kaolinite, quartz, feldspar and goethite. It was also noted that all blocks showed compressive strength less than 1.5 MPa. (author)

  8. Ozone production in summer in the megacities of Tianjin and Shanghai, China: a comparative study

    Science.gov (United States)

    Ran, Liang; Zhao, Chunsheng

    2013-04-01

    Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various non-methane hydrocarbons (NMHCs). Ozone pollution in summer was found to be more severe in the Tianjin region than in the Shanghai region, based on either the frequency or the duration of high ozone events. High ozone concentrations (>80 ppbv) of long duration (>6h) were frequently encountered in both urban and suburban Tianjin, while the occurrence of high ozone concentrations lasted for a shorter period (usually <4h) and had a much lower frequency in Shanghai. Such differences might be attributed to the large amount of highly reactive NMHCs in Tianjin. Model simulations based on measurements also reveal similar dependence of ozone production rates upon NMHC reactivity. Industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominated. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is probably a regional problem. Combined efforts to reduce ozone precursor emissions on a regional

  9. Numerical modeling of ozone production in a pulsed homogeneous discharge: A parameter study

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, J.O.; Eninger, J.E. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Industrial Electrotechnology

    1997-02-01

    The pulsed volume discharge is an alternative for the efficient generation of ozone in compact systems. This paper presents a parameter study of the reactions in this kind of homogeneous discharge by using a numerical model which solves plasma chemical kinetic rate and energy equations. Results are presented of ozone generation efficiency versus ozone concentration for different parameter combinations. Two parameter regimes are identified and analyzed. In the plasma phase ozone formation regime, where significant amounts of ozone are produced during the discharge pulse, it is found that higher ozone concentrations can be obtained than in the neutral phase ozone formation regime, where most of the ozone is formed after the discharge pulse. In the two-step ozone formation process, the rate of conversion of atomic oxygen plays a key role. In both regimes the ozone generation efficiency increases as n is increased or T{sub 0} decreased. The maximum concentration is 3% at 10 amagat and 100 K. The results on ozone accumulation in multiple pulse discharges are presented. In contrast to the single pulse case, higher efficiency is achieved at lower gas density. This scaling can be explained by losses due to ion currents. A tradeoff can be made between ozone generation efficiency and the number of pulses required to reach a certain concentration.

  10. TOLNET – A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Directory of Open Access Journals (Sweden)

    Newchurch Michael J.

    2016-01-01

    Full Text Available Ozone lidars measure continuous, high-resolution ozone profiles critical for process studies and for satellite validation in the lower troposphere. However, the effectiveness of lidar validation by using single-station data is limited. Recently, NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly timeresolved (few minutes tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation. This article briefly describes the concept, stations, major specifications of the TOLNet instruments, and data archiving.

  11. Contribution of Integrated Management Systems to University Management: Case Study of the Federal University of Rio Grande Do Norte

    Directory of Open Access Journals (Sweden)

    Lucas A.B.D Oliveira

    2011-01-01

    Full Text Available Problem statement: The Higher Education Institutions (IHL have intensified process of introducing undergraduate and graduate courses to more remote regions, which expanded the scope of what these institutions and allowed the formation of population of these regions. This expansion (whether by on-campus or distance learning presents new challenges for university management and integration of the players involved in this process. The purpose of this article was to demonstrate importance of information systems for university management and integration, focusing on decentralization and expansion of IHsL. Approach: The investigation was descriptive and the article is practical in nature. A case study was conducted at the Federal University of Rio Grande do Norte (Brazil. The research proposal of article was to answer the following question: How does an information system contribute to managing university expansion? Results: Results showed the relevance of integrated management systems, given university expansion and broadened horizons observed in recent years. The system analyzed proved to be extremely efficient, since practically all university activities can be monitored and evaluated. Conclusion: It was concluded that using integrated management systems during higher learning expansion maximizes this process, resulting in credible and rapid procedures that are more efficient and more effective.

  12. Ozone treatment of recurrent aphthous stomatitis: a double blinded study.

    Science.gov (United States)

    Al-Omiri, Mahmoud K; Alhijawi, Mohannad; AlZarea, Bader K; Abul Hassan, Ra'ed S; Lynch, Edward

    2016-06-15

    This study aimed to evaluate the use of ozone to treat recurrent aphthous stomatitis (RAS). Consecutive sixty-nine participants with RAS were recruited into this non-randomized double blind, controlled cohort observational study (test group). A control group of 69 RAS patients who matched test group with age and gender was recruited. RAS lesions in test group were exposed to ozone in air for 60 seconds while controls received only air. Ulcer size and pain were recorded for each participant at baseline and daily for 15 days. Ulcer duration was determined by recording the time taken for ulcers to disappear. The main outcome measures were pain due to the ulcer, ulcer size and ulcer duration. 138 RAS participants (69 participants and 69 controls) were analyzed. Ulcer size was reduced starting from the second day in test group and from the fourth day in controls (p ≤ 0.004). Pain levels were reduced starting from the first day in the test group and from the third day in controls (p ≤ 0.001). Ulcer duration, ulcer size after day 2 and pain levels were more reduced in the test group. In conclusion, application of ozone on RAS lesions for 60 seconds reduced pain levels and enhanced ulcers' healing by reducing ulcers' size and duration.

  13. Study on ozone treatment of soil for agricultural application of surface dielectric barrier discharge

    Science.gov (United States)

    Nagatomo, Takuya; Abiru, Tomoya; Mitsugi, Fumiaki; Ebihara, Kenji; Nagahama, Kazuhiro

    2016-01-01

    Recently, application of plasma technologies to the agricultural field has attracted much interest because residual pesticides and excessive nitrogen oxides contained in plants, soil, and groundwater have become a serious issue worldwide. Since almost all of the atmospheric discharge plasma generates ozone, the effects of ozone are among the key factors for their agricultural applications. We have proposed the use of ozone generated using surface barrier discharge plasma for soil disinfection or sterilization. In this work, the ozone consumption coefficient and diffusion coefficient in soil were measured by the ultraviolet absorption method. The pH(H2O) and amount of nitrogen nutrient in soil after ozone diffusion treatment were studied and plant growth was observed simultaneously. The effect of ozone treatment on the amount of DNA in soil was also investigated and compared with that determined from the obtained ozone consumption coefficient.

  14. A produção mais limpa como ferramenta da sustentabilidade empresarial: um estudo no estado do Rio Grande do Norte Cleaner production as corporate sustainability tool: a study within companies from Rio Grande do Norte State

    Directory of Open Access Journals (Sweden)

    Handson Claudio Dias Pimenta

    2012-08-01

    Full Text Available O presente estudo teve como objetivo avaliar a produção mais limpa - PmL como ferramenta da sustentabilidade empresarial através de uma série de estudos de múltiplos casos em empresas do estado do Rio Grande do Norte. Para tanto, foi aplicada a metodologia de PmL modelo SEBRAE (2005 em três empresas: uma indústria de alimentos (empresa 1, uma indústria de confecções (empresa 2 e uma concessionária de veículos (empresa 3. Pelos resultados, destacam-se, na empresa 1, ações de substituição de matéria-prima, otimização do uso de água e energia. Na empresa 2, otimização do uso de tecido e modificação tecnológica. Por fim, na empresa 3, as medidas de segregação na fonte e reciclagem externa de resíduos. Contudo, foram evidenciadas melhorias nas vertentes ambiental, social e econômica, preconizadas pela sustentabilidade empresarial. Entretanto, faz-se necessário mais transparência da alta administração no comprometimento com a continuidade das ações para, diante disto, melhor enquadrar a PmL como uma ferramenta da sustentabilidade.The purpose of this stydy was to assess the Cleaner Production - CP as a corporate sustainability tool, through a multiple case study in companies from the State of Rio Grande do Norte. To this end, our research methodology approach used the CP methodology from SEBRAE (2005 and applied it to the food industry (Company 1, the textile industry (Company 2 and to a car dealer (Company 3. Results highlighted, among other variables, the specific sustainability focus of any observed cleaner production activity. In company 1, raw material substitution, optimization of water and energy usage were the main foci. In Company 2, the foci were the optimization of fabric usage and technological modification (installation of washing equipment for the printing plates; before that, there was not control of water usage in this process, resulting in increased water consumption and disposal of waste. Company 3

  15. Localized ozone fumigation system for studying ozone effects on photosynthesis, respiration, electron transport rate and isoprene emission in field-grown Mediterranean oak species

    Energy Technology Data Exchange (ETDEWEB)

    Velikova, V.; Tsonev, T. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Plant Physiology; Pinelli, P.; Alessio, G.A.; Loreto, F. [CNR Inst. de Biologia Agroambiental e Forestale, Rome (Italy)

    2005-12-01

    Although ozone typically forms in highly populated and industrialized areas of the world, its presence in rural areas indicates that it can also be formed by interactions between anthropogenic and biogenic precursors. Ozone concentrations often rise above phytotoxic thresholds, resulting in reduced plant productivity and visible damage to foliage. This study examined the effects of acute and prolonged ozone exposure on some physiological traits of Mediterranean vegetation. A localized ozone fumigation system was used on single leaves in an oak canopy that was not in an enclosed system. The main objectives were to determine if primary and secondary metabolism of Mediterranean oak are sensitive to acute and prolonged, but not chronic, super-ambient or high ozone. Another objective was to determine if leaf ontogeny plays a role in establishing ozone sensitivities in the plant canopy. The study provided evidence that Mediterranean oak are generally resistant to short-term high ozone exposure, because no permanent damage was noted during the 3-day long fumigation. Carbon assimilation of current-year leaves was temporarily affected by exposure to high ozone, but recovery was quick and may have involved increasing resistance to carbon dioxide diffusion and photochemical damage. The fact that biochemical stress markers were influenced only by high ozone concentrations indicates that biochemical changes occurred in the absence of large physiological changes, but may affect the long-term development and performance of leaves exposed to ozone stress. 40 refs., 1 tab., 6 figs.

  16. Study on enhanced degradation of atrazine by ozonation in the presence of hydroxylamine.

    Science.gov (United States)

    Yang, Jingxin; Li, Ji; Dong, Wenyi; Ma, Jun; Cao, Jie; Li, Tingting; Li, Jiayin; Gu, Jia; Liu, Pingxin

    2016-10-05

    Degradation of atrazine (ATZ) by ozonation in the presence of hydroxylamine (HA) was experimentally investigated in this study. The results showed approximately 80% of ATZ was degraded by ozonation in the presence of HA, while only 20% was degraded by ozonation alone. The obvious inhibition of the ATZ degradation by tert-butanol suggested the enhanced ATZ degradation by ozone/HA was primarily attributed to OH. The OH yield was determined to be 25.8%. Additionally, the optimum HA dosage for the ATZ degradation was 4μM, when the ozone dosage was 20μM. The effects of pH, bicarbonate and temperature on ATZ degradation by ozone/HA were investigated in details. Most importantly, the enhanced ATZ degradation by ozonation in the presence of HA was still observed in real water especially at acidic pHs. Furthermore, the potential mechanism of OH formation during the reaction of ozone with HA was proposed herein. Nine products were identified by UPLC/Q-TOF-MS system. The ATZ degradation involved dealkylation, dechlorination-hydroxylation and olefination. The evolutions of the concentrations of three available transformation products including deethylatrazine, deisopropylatrazine and deethyldeisopropylatrazine in ozone/HA were evaluated and compared with that in ozonation alone.

  17. Ozone production in the megacities of Tianjin and Shanghai, China: a comparative study

    Directory of Open Access Journals (Sweden)

    W. L. Lin

    2012-04-01

    Full Text Available Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP and Yangtze River Delta (YRD. Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP and Shanghai (YRD. Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx and various volatile organic compounds (VOCs. Ozone pollution was found to be more severe in Tianjin than in Shanghai during the summer, either based on the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive VOC mixture in the Tianjin region. It is found that industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominate. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

  18. Ozone production in the megacities of Tianjin and Shanghai, China: a comparative study

    Science.gov (United States)

    Ran, L.; Zhao, C. S.; Xu, W. Y.; Han, M.; Lu, X. Q.; Han, S. Q.; Lin, W. L.; Xu, X. B.; Gao, W.; Yu, Q.; Geng, F. H.; Ma, N.; Deng, Z. Z.; Chen, J.

    2012-04-01

    Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various volatile organic compounds (VOCs). Ozone pollution was found to be more severe in Tianjin than in Shanghai during the summer, either based on the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive VOC mixture in the Tianjin region. It is found that industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominate. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

  19. Ozone production in summer in the megacities of Tianjin and Shanghai, China: a comparative study

    Directory of Open Access Journals (Sweden)

    L. Ran

    2012-08-01

    Full Text Available Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP and Yangtze River Delta (YRD. Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP and Shanghai (YRD. Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx and various non-methane hydrocarbons (NMHCs. Ozone pollution in summer was found to be more severe in the Tianjin region than in the Shanghai region, based on either the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive NMHCs in Tianjin. Industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominated. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is probably a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

  20. A Numerical Study of Tropospheric Ozone in the Springtime in East Asia

    Institute of Scientific and Technical Information of China (English)

    ZHANG Meigen(张美根); XU Yongfu(徐永福); Itsushi UNO; Hajime AKIMOTO

    2004-01-01

    The Models-3 Community Multi-scale Air Quality modeling system (CMAQ) coupled with the Regional Atmospheric Modeling System (RAMS) is applied to East Asia to study the transport and photochemical transformation of tropospheric ozone in March 1998. The calculated mixing ratios of ozone and carbon monoxide are compared with ground level observations at three remote sites in Japan and it is found that the model reproduces the observed features very well. Examination of several high episodes of ozone and carbon monoxide indicates that these elevated levels are found in association with continental outflow,demonstrating the critical role of the rapid transport of carbon monoxide and other ozone precursors from the continental boundary layer. In comparison with available ozonesonde data, it is found that the model-calculated ozone concentrations are generally in good agreement with the measurements, and the stratospheric contribution to surface ozone mixing ratios is quite limited.

  1. Study of ozone “weekend effect” in Shanghai

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O3) concentrations in Xujiahui are higher at week-ends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays. The possible chemical cause of ozone "weekend effect" is that NO2/NO ratio increases at weekends by 25.61% compared with those on weekdays. In addition, because of an average 12.13% reduction in NOx (NO + NO2) in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate. The rate of ozone production is a function of VOCs and NOx in the atmosphere. VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the "NOx-limited". The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone "weekend effect" in Xujiahui. Furthermore, combining with MICAPS cloud amount data, the fact that ozone "weekend effect" in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone "weekend effect" in Xujiahui of Shanghai.

  2. Ab Initio Studies of Stratospheric Ozone Depletion Chemistry

    Science.gov (United States)

    Lee, Timothy J.; Head-Gordon, Martin; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    An overview of the current understanding of ozone depletion chemistry, particularly with regards the formation of the so-called Antarctic ozone hole, will be presented together with an outline as to how ab initio quantum chemistry can be used to further our understanding of stratospheric chemistry. The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of fluorine, chlorine, bromine and nitrogen oxide species will be demonstrated by presentation of some example studies. The ab initio results will be shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the theoretical results are shown to fill in the gaps and to resolve experimental controversies. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of halogen oxide species will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of experimental studies.

  3. Diagnostic study on the relation between ozone and vorticity potential

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Basset, H. [Department of Astronomy and Meteorology, Faculty of Science, Al Azhar University, Nasr City, Cairo (Egypt); Gahein, A. [Egyptian Meteorological Authority, Cairo (Egypt)

    2003-04-01

    A diagnostic analysis of a Mediterranean system and the associated tropopause folding for the period 27 February to 10 March, 1987 is presented. Geopotential height, potential vorticity (PV) and relative humidity distributions were diagnosed. The analysis indicates clear correlation between the development of the cut-off low and the tropopause folding. A series of vertical cross-sections at the ends of the jet streaks demonstrated that a fold could be captured using potential vorticity and relative humidity. Q-vectors were employed to investigate vertical motion in the vicinity of the fold and showed the exact positions of descent corresponding to the fold along the entire length of the jet streak. The analysis also shows that the strong correlation between total ozone and column integrated vorticity potential holds well for all levels. As both quantities are integrals through the atmosphere, this result is consistent with, but does not prove, a high independent linear dependence between ozone and PV. More case studies are needed to assure the high linear dependence between ozone and PV. The maximum transport of ozone from the stratosphere to the troposphere is coinciding with the maximum developing system, and also with the maximum values of PV. [Spanish] Se presenta un analisis diagnostico de un Sistema mediterraneo y del pliegue de la tropopausa asociado durante el periodo del 27 de febrero al 10 de marzo de 1987. Se diagnosticaron la altitud neopotencial, el potencial de vorticidad y la distribucion de la humedad relativa. El analisis indica una correlacion clara entre el desarrollo de la baja segregada y el pliegue de la tropopausa. Una serie de cortes verticales en los extremos de las trazas del chorro demostraron que el pliegue puede ser capturado utilizando el potencial de vorticidad y la humedad relativa. Para investigar la movilidad vertical en la vecindad del pliegue se utilizaron vectores Q, y se demostraron las posiciones exactas de descenso

  4. Study of Vertical Ozone Distributions in the Stratosphere and Mesosphere at the Millimeter Wavelengths

    Science.gov (United States)

    Solomonov, S. V.; Kropotkina, E. P.; Rozanov, S. B.

    2003-08-01

    We present the results of stratospheric and mesospheric ozone observations at the millimeter wavelengths. It is shown that the microwave remote sensing methods are important for studying the physical and chemical processes which play a significant role in the ozone-layer depletion. Examples of the results of ozone observations at 142.2 GHz by the spectrometer of the P. N. Lebedev Physical Institute of the Russian Academy of Sciences (LPI RAS) illustrate the high efficiency of radiophysical techniques for atmospheric-ozone research.

  5. Cultura e clima organizacionais: um estudo em indústrias de laticínios do estado do Rio Grande do Norte Organizational culture and climate: a study in Rio Grande do Norte's dairy industries

    Directory of Open Access Journals (Sweden)

    Luiz Célio Souza Rocha

    2013-06-01

    Full Text Available O objetivo deste trabalho é investigar se existe relação entre a cultura organizacional e o clima organizacional, tendo, como locus de pesquisa, indústrias de laticínios do Rio Grande do Norte. Para tanto, realizou-se um estudo exploratório-descritivo e conclusivo-causal, em uma amostra composta por 211 funcionários de todos os níveis hierárquicos das empresas participantes, o que corresponde a 25,6% do total do setor. A partir dos dados coletados, identificaram-se as características pessoais dos respondentes, o perfil da cultura organizacional predominante e o clima organizacional predominante nas indústrias analisadas. Para a análise da cultura organizacional, utilizou-se o Modelo dos Valores Competitivos (CAMERON; QUINN, 2006 com adaptações, segundo Santos (2000. Para a análise do clima organizacional, utilizou-se a Escala de Medida de Clima Organizacional, proposta por Martins et al. (2004 e Martins (2008, com modificações de forma a se ter um instrumento mais enxuto. Os dados coletados foram submetidos a análises estatísticas quantitativas que permitiram chegar às seguintes conclusões: os perfis culturais foram encontrados de forma equilibrada nas organizações pesquisadas, com ênfase para os perfis "cultura clã" e "cultura mercado"; as organizações pesquisadas possuem um clima bom, segundo a classificação de Martins (2008, com destaque para os fatores "apoio da chefia e da organização" e "conforto físico", fatores estes bem coerentes com o perfil "cultura clã"; e os perfis culturais apresentaram influência sobre os fatores do clima organizacional. Assim, os resultados nos permitem concluir que há relações entre os perfis culturais e os fatores determinantes do clima organizacional nas organizações pesquisadas.The objective of this study is to investigate the relationship between organizational culture and the organizational climate in Rio Grande do Norte's dairy industries. An exploratory

  6. Study on the kinetics and transformation products of salicylic acid in water via ozonation.

    Science.gov (United States)

    Hu, Ruikang; Zhang, Lifeng; Hu, Jiangyong

    2016-06-01

    As salicylic acid is one of widely used pharmaceuticals, its residue has been found in various environmental water systems e.g. wastewater, surface water, treated water and drinking water. It has been reported that salicylic acid can be efficiently removed by advanced oxidation processes, but there are few studies on its transformation products and ozonation mechanisms during ozonation process. The objective of this study is to characterize the transformation products, investigate the degradation mechanisms at different pH, and propose the ozonation pathways of salicylic acid. The results showed that the rate of degradation was about 10 times higher at acidic condition than that at alkaline condition in the first 1 min when 1 mg L(-1) of ozone solution was added into 1 mg L(-1) of salicylic acid solution. It was proposed that ozone direct oxidation mechanism dominates at acidic condition, while indirect OH radical mechanism dominates at alkaline condition. A two stages pseudo-first order reaction was proposed at different pH conditions. Various hydroxylation products, carbonyl compounds and carboxylic acids, such as 2,5-dihydroxylbenzoic acid, 2,3-dihydroxylbenzoic acid, catechol, formaldehyde, glyoxal, acetaldehyde, maleic acid, acetic acid and oxalic acid etc. were identified as ozonation transformation products. In addition, acrylic acid was identified, for the first time, as ozonation transformation products through high resolution liquid chromatography-time of flight mass spectrometer. The information demonstrated in this study will help us to better understand the possible effects of ozonation products on the water quality. The degradation pathways of salicylic acid by ozonation in water sample were proposed. As both O3 and OH radical were important in the reactions, the degradation pathways of salicylic acid by ozonation in water sample were proposed at acidic and basic conditions. To our knowledge, there was no integrated study reported on the ozonation of

  7. Ozone therapy as an adjuvant for endondontic protocols: microbiological – ex vivo study and citotoxicity analyses

    Science.gov (United States)

    NOGALES, Carlos Goes; FERREIRA, Marina Beloti; MONTEMOR, Antonio Fernando; RODRIGUES, Maria Filomena de Andrade; Lage-MARQUES, José Luiz; ANTONIAZZI, João Humberto

    2016-01-01

    ABSTRACT Objectives This study evaluated the antimicrobial efficacy of ozone therapy in teeth contaminated with Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus using a mono-species biofilm model. Parallel to this, the study aimed to evaluate the cytotoxicity of ozone for human gingival fibroblasts. Material and Methods: One hundred and eighty single-root teeth were contaminated with a mono-species biofilm of Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus. Groups were formed: Group I – control; Group II – standard protocol; Group III – standard protocol + ozone gas at 40 µg/mL; and Group IV – standard protocol + aqueous ozone at 8 µg/mL. In parallel, human gingival fibroblasts were submitted to the MTT test. Cells were plated, then ozone was applied as follows: Group I (control) – broth medium; Group II – aqueous ozone at 2 µg/mL; Group III – aqueous ozone at 5 µg/mL; and Group IV – aqueous ozone at 8 µg/mL. Data were submitted to the Kruskal Wallis test and Bonferroni post hoc analyses to assess microbiology and cytotoxicity, respectively (p<0.05%). Results The results revealed antimicrobial efficacy by Group IV with no CFU count. The cytotoxicity assay showed Groups III and IV to be the most aggressive, providing a decrease in cell viability at hour 0 from 100% to 77.3% and 68.6%, respectively. Such a decrease in cell viability was reverted, and after 72 hours Groups III and IV provided the greatest increase in cell viability, being statistically different from Groups I and II. Conclusion According to the applied methodology and the limitations of this study, it was possible to conclude that ozone therapy improved the decontamination of the root canal ex vivo. Ozone was toxic to the cells on first contact, but cell viability was recovered. Thus, these findings suggest that ozone might be useful to improve root canal results. PMID:28076466

  8. Comparison studies of ozone precursors in Phoenix, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, C.; Guyton, J.; Lee, C.P. [Arizona Dept. of Environmental Quality, Phoenix, AZ (United States); Parmar, S. [Atmospheric Analysis and Consulting Co., Ventura, CA (United States)

    1994-12-31

    This paper will present the comparison of the ozone precursors monitoring program for Phoenix, Arizona during 1992 and 1993. Specific details and methodologies will be presented involving collection of air samples and analysis of speciated measurements for reactive VOC and carbonyl precursors responsible for ozone formation. Quality control and quality assurance techniques will also be discussed.

  9. Effect of ozone on periodontopathogenic species--an in vitro study.

    Science.gov (United States)

    Eick, Sigrun; Tigan, Marius; Sculean, Anton

    2012-04-01

    The in vitro study was aimed to determine the effect of ozone on periodontopathogenic microorganisms. Ozone was generated for 6 s-2 × 24 s (corresponding to 0.56 mg-2 × 2.24 mg of ozone) against 23 mainly anaerobic periodontopathogenic species. Agar diffusion test was used as a screening method. Then, the killing activity was tested in a serum-free environment and with 25% v/v inactivated serum. Further, the effect of ozone on bactericidal activity of native serum was analyzed against Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. Agar diffusion test showed a high efficacy of ozone against microorganisms, especially against Porphyromonas gingivalis. This result was confirmed by the killing tests; most of the strains in a concentration of 10(5) were completely eliminated after twofold 18-s application of ozone. Only four of the six potentially "superinfecting" species (Staphylococcus aureus, Enterococcus faecalis, Enterobacter cloacae, Candida albicans) survived in part. Addition of heat-inactivated serum reduced the killing rate of ozone by 78% after 6-s and by 47% after twofold 18-s exposures; no strain was completely eradicated after any application of ozone. The bactericidal effect of native serum was enhanced after application of ozone; no effect was visible on the included A. actinomycetemcomitans strain which was found to be completely resistant to the bactericidal action of serum. In conclusion, (a) ozone has a strong antibacterial activity against putative periodontopathogenic microorganisms, and (b) the bactericidal effect is reduced in the presence of serum. Ozone may have potential as an adjunctive application to mechanical treatment in periodontitis patients.

  10. Studies on the biological effects of ozone: 10. Release of factors from ozonated human platelets.

    Science.gov (United States)

    Valacchi, G; Bocci, V

    1999-01-01

    In a previous work we have shown that heparin, in the presence of ozone (O3), promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF), transforming growth factor beta1 (TGF-beta1) and interleukin-8 (IL-8) are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limb ischemia treated with O3 autohaemoteraphy (O3-AHT).

  11. Studies on the Biological Effects of Ozone: 10. Release of Factors from Ozonated Human Platelets

    Directory of Open Access Journals (Sweden)

    G. Valacchi

    1999-01-01

    Full Text Available In a previous work we have shown that heparin, in the presence of ozone (O3, promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF, transforming growth factor β1 (TGF-β1 and interleukin-8(IL-8 are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limbischemia treated with O3 autohaemoteraphy (O3-AHT.

  12. In situ ozone data for evaluation of the laser absorption spectrometer ozone remote sensor: 1979 southeastern Virginia urban plume study summer field program

    Science.gov (United States)

    Gregory, G. L.; Mcdougal, D. S.; Mathis, J. J., Jr.

    1980-01-01

    Ozone data from the 1979 Southeastern Virginia Urban Study (SEV-UPS) field program are presented. The SEV-UPS was conducted for evaluation of an ozone remote sensor, the Laser Absorption Spectrometer. During the measurement program, remote-sensor evaluation was in two areas; (1) determination of the remote sensor's accuracy, repeatability, and operational characteristics, and (2) demonstration of the application of remotely sensed ozone data in air-quality studies. Data from six experiments designed to provide in situ ozone data for evaluation of the sensor in area 1, above, are presented. Experiments consisted of overflights of a test area with the remote sensor aircraft while in situ measurements with a second aircraft and selected surface stations provided correlative ozone data within the viewing area of the remote sensor.

  13. The influence of temperature on ozone production under varying NOx conditions - a modelling study

    Science.gov (United States)

    Coates, Jane; Mar, Kathleen A.; Ojha, Narendra; Butler, Tim M.

    2016-09-01

    Surface ozone is a secondary air pollutant produced during the atmospheric photochemical degradation of emitted volatile organic compounds (VOCs) in the presence of sunlight and nitrogen oxides (NOx). Temperature directly influences ozone production through speeding up the rates of chemical reactions and increasing the emissions of VOCs, such as isoprene, from vegetation. In this study, we used an idealised box model with different chemical mechanisms (Master Chemical Mechanism, MCMv3.2; Common Representative Intermediates, CRIv2; Model for OZone and Related Chemical Tracers, MOZART-4; Regional Acid Deposition Model, RADM2; Carbon Bond Mechanism, CB05) to examine the non-linear relationship between ozone, NOx and temperature, and we compared this to previous observational studies. Under high-NOx conditions, an increase in ozone from 20 to 40 °C of up to 20 ppbv was due to faster reaction rates, while increased isoprene emissions added up to a further 11 ppbv of ozone. The largest inter-mechanism differences were obtained at high temperatures and high-NOx emissions. CB05 and RADM2 simulated more NOx-sensitive chemistry than MCMv3.2, CRIv2 and MOZART-4, which could lead to different mitigation strategies being proposed depending on the chemical mechanism. The increased oxidation rate of emitted VOC with temperature controlled the rate of Ox production; the net influence of peroxy nitrates increased net Ox production per molecule of emitted VOC oxidised. The rate of increase in ozone mixing ratios with temperature from our box model simulations was about half the rate of increase in ozone with temperature observed over central Europe or simulated by a regional chemistry transport model. Modifying the box model set-up to approximate stagnant meteorological conditions increased the rate of increase of ozone with temperature as the accumulation of oxidants enhanced ozone production through the increased production of peroxy radicals from the secondary degradation of

  14. Experimental Study on Minimization of Sludge Production by Ozonation Process

    Institute of Scientific and Technical Information of China (English)

    何圣兵; 薛罡; 王宝贞; 王琳

    2003-01-01

    Based on the hypothesis of reducing sludge production under cryptic growth conditions, ozone was used as cell lysis agent to treat excess sludge,and then the ozonated supernatant was returned to the aeration tank. The results show that COD and NH+4-N removal efficiencies in ozonation process were 87.96% and 84.42%, respectively. Meanwhile, a low excess sludge yield coefficient of 0. 113 ( g SS/g COD removed) was obtained. Compared with that of the control test, the process configuration decreased the excess sludge production by 51.3%.

  15. Laboratory Studies of Halogen Oxides Important to Stratospheric Ozone Depletion

    Science.gov (United States)

    Wilmouth, D. M.; Klobas, J. E.; Anderson, J. G.

    2016-12-01

    Inorganic chlorine and bromine molecules are primarily responsible for stratospheric ozone destruction, with BrO, ClO, and ClOOCl comprising the two reaction cycles that cause most polar ozone losses. Despite comprehensive international treaties regulating CFCs and halons, seasonal polar ozone depletion will likely continue for decades to come. Accurate spectroscopic and kinetic measurements of inorganic bromine and chlorine molecules obtained in the laboratory are essential for reducing uncertainty in atmospheric models, better interpreting atmospheric field measurements, and forming trusted projections of future ozone changes. Here we present results from recent work in our laboratory using absorption spectroscopy and atomic resonance fluorescence detection to determine rate constants of halogen reactions, the equilibrium constant of ClO/ClOOCl, and absorption cross sections of several halogen oxides using a new cold trap-thermal desorption approach.

  16. STUDY OF THE INFLUENCE OF OZONE ON THE GROWTH PROCESSES OF MAIZE SEEDS

    Directory of Open Access Journals (Sweden)

    Shevchenko A. A.

    2015-01-01

    Full Text Available Increasing the yield of crops is a global challenge substantiated by the scientists from all over the world. To achieve this goal, there are various ways, one of which is the ozonation of seeds before sowing. This method inhibits harmful microflora, which could be formed on the seed during the period of storage, and excites the chemical processes within the seed that can accelerate the process of growth. But despite the positive effect of ozone-air mixture of seeds and a variety of conducting research there is still no reliable data on the technological parameters of ozone effects on seed crops (e.g., corn. In this regard, we have conducted experimental studies to determine the effective parameters of the ozonation of corn seeds, such as the concentration of ozone in the ozone-air mixture, exposure time and binning after treatment. The influence of these parameters was assessed by changes in growth performance of seed, such as germination, germination and growth of strength. Just at the end of the pilot study we carried out a statistical analysis of the data, which allowed us to estimate the degree of influence of each independent parameter (ozone concentration, exposure time, binning after treatment for each dependent parameter (germination energy, germination, growth force. The data obtained is presented in the article

  17. Improved hurricane forecasting from a variational bogus and ozone data assimilation (BODA) scheme: case study

    Science.gov (United States)

    Liu, Yin; Zhang, Wei

    2016-12-01

    This study develops a proper way to incorporate Atmospheric Infrared Sounder (AIRS) ozone data into the bogus data assimilation (BDA) initialization scheme for improving hurricane prediction. First, the observation operator at some model levels with the highest correlation coefficients is established to assimilate AIRS ozone data based on the correlation between total column ozone and potential vorticity (PV) ranging from 400 to 50 hPa level. Second, AIRS ozone data act as an augmentation to a BDA procedure using a four-dimensional variational (4D-Var) data assimilation system. Case studies of several hurricanes are performed to demonstrate the effectiveness of the bogus and ozone data assimilation (BODA) scheme. The statistical result indicates that assimilating AIRS ozone data at 4, 5, or 6 model levels can produce a significant improvement in hurricane track and intensity prediction, with reasonable computation time for the hurricane initialization. Moreover, a detailed analysis of how BODA scheme affects hurricane prediction is conducted for Hurricane Earl (2010). It is found that the new scheme developed in this study generates significant adjustments in the initial conditions (ICs) from the lower levels to the upper levels, compared with the BDA scheme. With the BODA scheme, hurricane development is found to be much more sensitive to the number of ozone data assimilation levels. In particular, the experiment with the assimilation of AIRS ozone data at proper number of model levels shows great capabilities in reproducing the intensity and intensity changes of Hurricane Earl, as well as improve the track prediction. These results suggest that AIRS ozone data convey valuable meteorological information in the upper troposphere, which can be assimilated into a numerical model to improve hurricane initialization when the low-level bogus data are included.

  18. Land cover change impacts on surface ozone: an observation-based study

    Science.gov (United States)

    Zhang, Yi; Lin, Jintai

    2016-04-01

    Ozone air quality is a critical global environmental issue. Although it is clear that industrialization and urbanization has increased surface ozone through enhanced emissions of its precursors, much less is known about the role of changes in land cover and land use. Human activities have substantially altered the global land cover and land use through agriculture, urbanization, deforestation, and afforestation. Changes in Land cover and land use affect the ozone levels by altering soil emissions of nitrogen oxides (NOx), biogenic emissions of volatile organic compounds (VOCs), and dry deposition of ozone itself. This study performs a series of experiments with a chemical transport model based on satellite observation of land types to analyze the influences of changes in land cover/land use and their impact on surface ozone concentration. Our results indicate that land cover change explains 1-2 ppbv of summertime surface ozone increase in the Western United States and 1-6 ppbv of increase in Southern China between 2001 and 2012. This is largely driven by enhanced isoprene emissions and soil NOx emissions. It is also found that land cover change itself elevates summertime surface zone in Canadian coniferous forests by up to 4 ppbv mainly through substantial decreases in ozone dry deposition associated with increased vegetation density in a warmer climate.

  19. Biomarkers of Oxidative Stress Study IV. Are Antioxidants Markers of Ozone Exposure?

    Science.gov (United States)

    To determine whether the oxidative effects of ozone would result in losses of antioxidants from plasma, and possibly bronchoalveolar lavage fluid (BALF). This research is part of a comprehensive, multilaboratory validation study searching for noninvasive biomarkers of oxidative ...

  20. TOWARDS RELIABLE AND COST-EFFECTIVE OZONE EXPOSURE ASSESSMENT: PARAMETER EVALUATION AND MODEL VALIDATION USING THE HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    Science.gov (United States)

    Accurate assessment of chronic human exposure to atmospheric criteria pollutants, such as ozone, is critical for understanding human health risks associated with living in environments with elevated ambient pollutant concentrations. In this study, we analyzed a data set from a...

  1. Treatment of a colored groundwater by ozone-biofiltration: pilot studies and modeling interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, B.E.; Stilwell, D.; Garside, J.C.; Amy, G.L.; Spangenberg, C.; Kalinsky, A.; Akiyoshi, E. [Northwestern University, Evanston, IL (USA). Dept. of Civil & Environmental Engineers

    2002-07-01

    Pilot studies investigated the fates of color, dissolved organic carbon (DOC), and biodegradable organic matter (BOM) by the tandem of ozone plus biofiltration for treating a source water having significant color (50 cu) and DOC (3.2 mg/l). Transferred ozone doses were from 1.0 to 1.8 g O{sub 3}/g C. Rapid biofilters used sand, anthracite, or granular activated carbon as media with empty-bed contact time (EBCT) up to 9 min. The pilot studies demonstrated that ozonation plus biofiltration removed most color and substantial DOC, and increasing the transferred ozone dose enhanced the removals. Compared to sand and anthracite biofilters, the GAC biofilter gave the best performance for color and DOC removal, but some of this enhanced performance was caused by adsorption, since the GAC was virgin at the beginning of the pilot studies.

  2. Update of national ozone study: Where are we now?

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, B.

    1996-12-31

    This paper is one of three keynote presentations given at the conference. It addresses the issue of national ozone research in focusing on the regional task force, Ozone Transport Assessment Group (OTAG). The overall objectives of the OTAG initiatives are reported. These include development of a comprehensive regional emissions inventory, selection of research models and protocols, identification of criteria for selecting emissions control strategies, and development of a framework for a NO{sub x} trading system. Findings from preliminary modeling runs and analyses are presented. 15 figs., 15 tabs.

  3. Effects of the Nordic photoperiod on ozone sensitivity and repair in different clover species studied using infrared imaging.

    Science.gov (United States)

    Futsaether, Cecilia M; Vollsnes, Ane V; Kruse, Ole Mathis Opstad; Otterholt, Eli; Kvaal, Knut; Eriksen, Aud B

    2009-12-01

    Plants in Nordic regions can be more ozone sensitive at a given ozone concentration than plants at lower latitudes. A recent study shows that the Nordic summer photoperiod, particularly the dim nighttime light, can increase visible foliar injury and alter leaf transpiration in subterranean clover. Effects of photoperiod on the ozone sensitivity of white and red clover cultivars adapted to Nordic conditions were investigated. Although ozone induced visible foliar injury and leaf transpirational changes in white clover, the effects were independent of photoperiod. In red clover, ozone combined with a long photoperiod with dim nights (8 nights) induced more severe visible injuries than with a short photoperiod. Furthermore, transpirational changes in red clover depended on photoperiod. Thus, a long photoperiod can increase ozone sensitivity differently in clover cultivars with different degrees of adaptation to northern conditions, suggesting that ozone indices used in risk analysis should take this effect into account.

  4. [Effects of elevated ozone on Pinus armandii growth: a simulation study with open-top chamber].

    Science.gov (United States)

    Liu, Chang-Fu; Liu, Chen; He, Xing-Yuan; Ruan, Ya-Nan; Xu, Sheng; Chen, Zhen-Ju; Peng, Jun-Jie; Li, Teng

    2013-10-01

    By using open-top chamber (OTC) and the techniques of dendrochronology, this paper studied the growth of Pinus armandii under elevated ozone, and explored the evolution dynamics and adaptation mechanisms of typical forest ecosystems to ozone enrichment. Elevated ozone inhibited the stem growth of P. armandii significantly, with the annual growth of the stem length and diameter reduced by 35.0% and 12.9%, respectively. The annual growth of tree-ring width and the annual ring cells number decreased by 11.5% and 54.1%, respectively, but no significant change was observed in the diameter of tracheid. At regional scale, the fluctuation of ozone concentration showed significant correlation with the variation of local vegetation growth (NDVI).

  5. Studying cumulative ozone exposures in Europe during a 7-year period

    Science.gov (United States)

    Bastrup-Birk, Annemarie; Brandt, JøRgen; Zlatev, Zahari; Uria, Ignacio

    1997-10-01

    Ozone is one of the most harmful pollutants in the troposphere. High ozone concentrations can damage plants, animals and humans. The damaging effects depend on the magnitude of a critical level of a special parameter, the cumulative ozone exposure. This is why cumulative ozone exposures must be carefully studied. It is important to determine the relationships between relevant emissions (NOx emissions, human-made VOC emissions, and/or a combination of NOx emissions and human-made VOC emissions) and cumulative ozone exposures. All these issues are discussed in this paper. Meteorological data from seven consecutive years, from 1989 to 1995, have been used in the experiments with different scenarios for varying the emissions (the NOx emissions, the human-made VOC emissions, as well as both the NOx emissions and the human-made VOC emissions). The particular air pollution model used in this study is the Danish Eulerian Model. Several hundred runs with different input data (meteorological data and/or emission data) have been performed. Advanced visualization techniques are used to interpret the large amount of digital data collected in these runs and to show clearly different trends and relationships that are normally hidden behind millions and millions of numbers. The model results were compared with measurements taken at more than 80 stations located in different European countries. The experiments indicate that it is sufficient to carry out computations over 5 consecutive years in order to eliminate the influence of extreme meteorological conditions (very warm or very cold summer months) on the cumulative ozone exposures, while this effect is clearly seen if less than 5 years are used in the experiments. It is shown that the relationship between the emissions (NOx and/or human-made VOC emissions) and the cumulative ozone exposures is in general nonlinear. Finally, it is illustrated that the critical values for ozone exposures are exceeded in most of Europe (in many

  6. EOS Aura and Future Satellite Studies of the Ozone Layer

    Science.gov (United States)

    Schoeberl, Mark R.

    2007-01-01

    The EOS Aura mission, launched in 2004, provides a comprehensive assessment of the stratospheric dynamics and chemistry. This talk will focus on results from Aura including the chemistry of polar ozone depletion. The data from Aura can be directly linked to UARS data to produce long term trends in stratospheric trace gases.

  7. Sampling Ozone Exposure of Canadian Forests at Different Scales: Some Case Studies

    Directory of Open Access Journals (Sweden)

    R.M. Cox

    2001-01-01

    Full Text Available The use of passive samplers in extensive monitoring, such as that used in national forest health monitoring plots, indicates that these devices are able to determine both spatial and temporal differences in ozone exposure of the plots. This allows for categorisation of the plots and the potential for cause-effect analysis of certain forest health responses. Forest exposure along a gradient of air pollution deposition demonstrates large variation in accumulated exposures. The efficacy of using passive samplers for in situ monitoring of forest canopy exposure was also demonstrated. The sampler data produced weak relationships with ozone values from the nearest �continuous� monitor, even though data from colocated samplers showed strong relationships. This spatial variation and the apparent effect of elevation on ozone exposure demonstrate the importance of topography and tree canopy characteristics in plant exposure on a regional scale. In addition, passive sampling may identify the effects of local pollutant gases, such as NO, which may scavenge ozone locally only to increase the production of this secondary pollutant downwind, as atmospheric reactions redress the equilibrium between concentrations of this precursor and those of the generated ozone. The use of passive samplers at the stand level is able to resolve vertical profiles within the stand and edge effects that are important in exposure of understorey and ground flora. Recent case studies using passive samplers to determine forest exposure to ozone indicate a great potential for the development of spatial models on a regional, landscape, and stand level scale.

  8. Study of the superficial ozone concentrations in the atmosphere of Comunidad de Madrid using passive samplers

    Directory of Open Access Journals (Sweden)

    D. Galán Madruga

    2001-06-01

    Full Text Available The ozone is a secondary atmospheric pollutant which is generated for photochemical reactions of volatil organic compounds (VOC’s and nitrogen oxides (NOx. In Spain the ozone is a big problem as a consequence of the solar radiation to reach high levels. Exposure over a period of time to elevated ozone concentrations can cause damage in the public health and alterations in the vegetation.The aim of this study is to carry out the development and validation of a measurement method to let asses the superficial ozone levels in the Comunidad de Madrid, by identifing the zones more significants, where to measure with UV photometric monitors (automatics methods this pollutant and where the health and the vegetation can be affected. To such effect, passive samplers are used, which have glass fiber filters coated with a solution of sodium nitrite, potassium carbonate, glycerol and water. The nitrite ion in the presence of ozone is oxidized to nitrato ion, which it is extrated with ultrapure water and analyzed for ion chromatography, by seen proportional to the concentration existing in the sampling point.The results of validation from field tests indicate a excellent correlation between the passive and the automatic method.The higher superficial ozone concentrations are placed in rural zones, distanced of emission focus of primary pollutants (nitrogen oxides and volatil organic compounds... principally in direction soutwest and northwest of the Comunidad of Madrid.

  9. PARAMETER EVALUATION AND MODEL VALIDATION OF OZONE EXPOSURE ASSESSMENT USING HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    Science.gov (United States)

    To examine factors influencing long-term ozone exposures by children living in urban communities, we analyzed longitudinal data on personal, indoor, and outdoor ozone concentrations as well as related housing and other questionnaire information collected in the one-year-long Harv...

  10. MUCESS-Supported Ozone Studies in Upstate New York and along the Texas Gulf Coast

    Science.gov (United States)

    Hromis, A.; Balimuttajjo, M.; Johnson, A.; Wright, J. M.; Idowu, A.; Vieyra, D.; Musselwhite, D.; Morris, P. A.

    2010-12-01

    The Minority University Consortium for Earth and Space Sciences (MUCESS) supports yearly atmospheric science workshops at their respective institutions. The NSF funded program has enabled Universities and colleges that are part of MUCESS, which include Medgar Evers College, City University of NY, University of Houston-Downtown and South Carolina State University, to develop and support atmospheric studies. The goal of the annual workshops is to instruct the students on the basics of atmospheric science and provide them with hands-on experience for preparing and calibrating the instruments for measuring atmospheric parameters. The instruments are subsequently attached to weather balloons. The data is obtained with an ENSCI ECC ozonesonde, which measures ozone concentrations to parts per billion, and an iMET radiosonde, which records temperature, pressure, relative humidity, and GPS altitude and position. In March 2010, Medgar Evers hosted the workshop in Paradox, NY. Students and faculty from the three institutions attended the 3 day workshop. Subsequent to the annual workshop students from the University of Houston-Downtown (UHD) launched a series of four Sunday launches during the summer from the campus. The data from both the workshop and UHD launches was subsequently analyzed to compare ozone profiles within the troposphere and stratosphere. Comparing rural (Paradox, NY) and urban ozone profiles (Houston, Tx) provides an invaluable experience. An excellent example is the March Paradox temperature profiles as the data indicates a mid-tropospheric temperature inversion. Coincident with this inversion, there is a significant rise in ozone concentrations, the source of which is likely of non-local provenance. In contrast, the Houston summer data indicates a different story as ground level ozone is produced by industrial and transportation-related ozone sources levels which vary. Weekend ground level ozone levels on Sunday are usually relatively low because of

  11. Variations of Ground-level Ozone Concentration in Malaysia: A Case Study in West Coast of Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Hashim Nur Izzah Mohamad

    2017-01-01

    Full Text Available Hourly ground ozone concentration, measured from the monitoring stations in the West Coast of Peninsular Malaysia for the period of 10 years (2003-2012 were used to analyse the ozone characteristic in Nilai, Melaka and Petaling Jaya. The prediction of tropospheric ozone concentrations is very important due to the negative impacts of ozone on human health, climate and vegetation. The mean concentration of ozone at the studied areas had not exceeded the recommended value of Malaysia Ambient Air Quality Guideline (MAAQG for 8-hour average (0.06 ppm, however some of the measurements exceeded the hourly permitted concentration by MAAQG that is 0.1 ppm. Higher concentration of ozone can be observed during the daytime since ozone needs sunlight for the photochemical reactions. The diurnal cycle of ozone concentration has a mid-day peak (14:00-15:00 and lower night-time concentrations. The ozone concentration slowly rises after the sun rises (08:00, reaching a maximum during daytime and then decreases until the next morning.

  12. Ozone and Botrytis interactions in onion-leaf dieback: open-top chamber studies

    Energy Technology Data Exchange (ETDEWEB)

    Wukasch, R.T.; Hofstra, G.

    1977-09-01

    Paired open-top chambers were used to study interactions between Botrytis spp. and ozone in field-grown onions. Charcoal filters removed 35 to 65% of the ambient ozone, resulting in six-fold reduction of onion leaf dieback and a 28% increase in onion yield compared with unfiltered chambers. Symptoms of leaf injury appeared soon after ozone levels exceeded 294 ..mu..g/m/sup 3/ (0.15 ppm) for 4 hr. Lesions caused by Botrytis were few because no dew formed in the chambers. However, when leaves were wetted with foggers, inoculation with mycelial suspensions of B. sauamosa in late August produced significantly more lesions and leaf dieback in the unfiltered chamber. Botrytis squamosa, B. cinerea, B. allii, and several genera of secondary fungi were isolated from these lesions. Botrytis squamosa was recovered from lesions only, whereas B. cinerea and B. allii were associated more generally with onion leaf tissue regardless of lesions. 25 references, 1 figure, 2 tables.

  13. Pilot Study on Nanofiltration Combined with Ozonation and GAC for Advanced Drinking Water Treatment

    Institute of Scientific and Technical Information of China (English)

    XUE Gang; HE Sheng-bing; WANG Xin-ze

    2004-01-01

    A pilot-scale study of advanced drinking water treatment was carried out in test site, and a combination of ozonation, granular activated carbon (GAC) and nanofiltration was employed as the experimental process. By optimizing the operational parameters of ozonation and GAC, a large quantity of micro-pollutants in drinking water was removed, which made the post-positioned nanofiltration operate more reliably. It was evident that nanofiltration shows good performance for removing residual organic matter, meantime partial minerals can also be retained by nanofiltration. Therefore the quality of drinking water can be further improved. In addition, NF membrane fouling and scaling can be solved by concentrate recycling, anti-scalant dosing and chemical rinsing effectively. By GAC adsorption for the residue chlorine and ozone self-decomposition, their oxidation on NF membrane material can be eliminated completely.

  14. Spaceship Nigeria: A Topic Study for Global Warming, Greenhouse Effect and Ozone Layer Depletion.

    Science.gov (United States)

    Okebukola, Peter; Akpan, Ben B.

    1997-01-01

    Explains the concept of a topic study, how it meets the needs of teachers seeking to integrate their teaching, and how it is especially well suited for environmental education. Outlines curriculum for a topic study on the greenhouse effect and ozone layer depletion. (DDR)

  15. Global Warming and Ozone Layer Depletion: STS Issues for Social Studies Classrooms.

    Science.gov (United States)

    Rye, James A.; Strong, Donna D.; Rubba, Peter A.

    2001-01-01

    Explores the inclusion of science-technology-society (STS) education in social studies. Provides background information on global warming and the depletion of the ozone layer. Focuses on reasons for teaching global climate change in the social studies classroom and includes teaching suggestions. Offers a list of Web sites about global climate…

  16. Spaceship Nigeria: A Topic Study for Global Warming, Greenhouse Effect and Ozone Layer Depletion.

    Science.gov (United States)

    Okebukola, Peter; Akpan, Ben B.

    1997-01-01

    Explains the concept of a topic study, how it meets the needs of teachers seeking to integrate their teaching, and how it is especially well suited for environmental education. Outlines curriculum for a topic study on the greenhouse effect and ozone layer depletion. (DDR)

  17. Global Warming and Ozone Layer Depletion: STS Issues for Social Studies Classrooms.

    Science.gov (United States)

    Rye, James A.; Strong, Donna D.; Rubba, Peter A.

    2001-01-01

    Explores the inclusion of science-technology-society (STS) education in social studies. Provides background information on global warming and the depletion of the ozone layer. Focuses on reasons for teaching global climate change in the social studies classroom and includes teaching suggestions. Offers a list of Web sites about global climate…

  18. Comparison of N-nitrosodimethylamine formation mechanisms from dimethylamine during chloramination and ozonation: A computational study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yong Dong, E-mail: ydliu@bjut.edu.cn; Zhong, Rugang

    2017-01-05

    Highlights: • NDMA formation mechanisms from dimethylamine in chloramination/ozonation were reinvestigated by G4 method. • The reactivity order of halo-/hydroxyl-amines reacting with dimethylamine is NHCl{sub 2} ∼ NHBrCl > NH{sub 2}Cl >> NH{sub 2}OH. • Nitrene compound is an important intermediate to form NDMA in oxidation reaction. • Oxidation of unsymmetrical dimethylhydrazine by O{sub 2} is significantly less feasible compared to that by O{sub 3}. • The amines containing the second nitrogen source are potential NDMA precursors in ozonation. - Abstract: N-nitrosodimethylamine (NDMA) as a disinfection by-product has recently become the focus of considerable research interest due to its unusually high carcinogenicity. In this study, the formation mechanisms of NDMA from dimethylamine (DMA) during chloramination and ozonation were investigated by using the quantum chemical G4 method. The reactivity of haloamines and hydroxylamine reacting with DMA was found in the order: NHCl{sub 2} ∼ NHBrCl (Br{sup -}leaving) > NHBr{sub 2} > NH{sub 2}Cl ∼ NH{sub 2}Br >> NH{sub 2}OH. This offers a theoretical support for the experimentally proposed mechanism that dimethylamine reacts with NHCl{sub 2} rather than NH{sub 2}Cl to form chlorinated unsymmetrical dimethylhydrazine intermediate and the existence of bromochloramine in the presence of bromide during chloramination, and explains the observation that NDMA yield during ozonation is much lower than that during chloramination. Importantly, an N,N-dimethylaminonitrene was found to be a significant intermediate to form NDMA in oxidation reactions by molecular oxygen and ozone. Additionally, results suggest that the amines containing the second nitrogen source directly connecting or close to the N-(CH{sub 3}){sub 2} moiety are potential significant NDMA precursors upon ozonation. The findings of this study are helpful for expanding the knowledge of NDMA formation mechanism, and predicting potential NDMA precursors

  19. Physicochemical patterns of ozone absorption by wood

    Science.gov (United States)

    Mamleeva, N. A.; Lunin, V. V.

    2016-11-01

    Results from studying aspen and pine wood ozonation are presented. The effect the concentration of ozone, the reagent residence time, and the content of water in a sample of wood has on ozone consumption rate and ozone demand are analyzed. The residence time is shown to determine the degree of ozone conversion degree and the depth of substrate destruction. The main patterns of ozone absorption by wood with different moisture content are found. Ways of optimizing the ozonation of plant biomass are outlined.

  20. Simulation of Tropospheric Ozone with MOZART-2:An Evaluation Study over East Asia

    Institute of Scientific and Technical Information of China (English)

    LIU Qianxia; ZHANG Meigen; WANG Bin

    2005-01-01

    Climate changes induced by human activities have attracted a great amount of attention. With this,a coupling system of an atmospheric chemistry model and a climate model is greatly needed in China for better understanding the interaction between atmospheric chemical components and the climate. As the first step to realize this coupling goal, the three-dimensional global atmospheric chemistry transport model MOZART-2 (the global Model of Ozone and Related Chemical Tracers, version 2) coupled with CAM2 (the Community Atmosphere Model, version 2) is set up and the model results are compared against observations obtained in East Asia in order to evaluate the model performance. Comparison of simulated ozone mixing ratios with ground level observations at Minamitorishima and Ryori and with ozonesonde data at Naha and Tateno in Japan shows that the observed ozone concentrations can be reproduced reasonably well at Minamitorishima but they tend to be slightly overestimated in winter and autumn while underestimated a little in summer at Ryori. The model also captures the general features of surface CO seasonal variations quite well, while it underestimates CO levels at both Minamitorishima and Ryori.The underestimation is primarily associated with the emission inventory adopted in this study. Compared with the ozonesonde data, the simulated vertical gradient and magnitude of ozone can be reasonably well simulated with a little overestimation in winter, especially in the upper troposphere. The model also generally captures the seasonal, latitudinal and altitudinal variations in ozone concentration. Analysis indicates that the underestimation of tropopause height in February contributes to the overestimation of winter ozone in the upper and middle troposphere at Tateno.

  1. Atmosphere-Ocean Ozone Exchange – A Global Modeling Study of Biogeochemical, Atmospheric and Water-Side Turbulence Dependencies

    NARCIS (Netherlands)

    Ganzeveld, L.N.; Helmig, D.; Fairall, C.W.; Hare, J.; Pozzer, A.

    2009-01-01

    The significance of the removal of tropospheric ozone by the oceans, covering ~2/3 of the Earth's surface, has only been addressed in a few studies involving water tank, aircraft, and tower flux measurements. On the basis of results from these few observations of the ozone dry deposition velocity (V

  2. Atmosphere-Ocean Ozone Exchange – A Global Modeling Study of Biogeochemical, Atmospheric and Water-Side Turbulence Dependencies

    NARCIS (Netherlands)

    Ganzeveld, L.N.; Helmig, D.; Fairall, C.W.; Hare, J.; Pozzer, A.

    2009-01-01

    The significance of the removal of tropospheric ozone by the oceans, covering ~2/3 of the Earth's surface, has only been addressed in a few studies involving water tank, aircraft, and tower flux measurements. On the basis of results from these few observations of the ozone dry deposition velocity

  3. Statistical considerations for plot design, sampling procedures, analysis, and quality assurance of ozone injury studies

    Science.gov (United States)

    Michael Arbaugh; Larry Bednar

    1996-01-01

    The sampling methods used to monitor ozone injury to ponderosa and Jeffrey pines depend on the objectives of the study, geographic and genetic composition of the forest, and the source and composition of air pollutant emissions. By using a standardized sampling methodology, it may be possible to compare conditions within local areas more accurately, and to apply the...

  4. Degradation of the northern paraná landscape: a study on forest fragments/ Degradação da paisagem norte-paranaense: um estudo de fragmentos florestais

    Directory of Open Access Journals (Sweden)

    Efraim Rodrigues

    2002-05-01

    Full Text Available Due to a fast occupation process, nearly all of the native vegetal covering of northern Paraná was devastated. Considering the lack of basic studies that support the management of forest remainders, this dissertation studies the forest fragmentation of the landscape in a transect of 180 km (between Maringá and Jacarezinho, considering a time and/or age of occupation gradient. One has adopted the hypothesis that the landscape to west, colonized from 1930 (Londrina and 1947 (Maringá, suffered smaller degradation in a comparison with what happened in the landscape situated further to east (and colonized in the mid 19th century and early 20th century. Results demonstrated that the initial hypothesis should be refute. Historical and factors socioeconomic influenced the occupation way and, consequently, the distribution of the forest fragments in the landscape.Devido ao rápido processo de ocupação, quase toda cobertura vegetal nativa do Norte do Paraná foi devastada. Considerando a necessidade de estudos básicos que dêem suporte ao manejo de remanescentes florestais, este trabalho estuda a fragmentação florestal da paisagem num transecto de 180 km (entre Jacarezinho e Maringá. Adotou-se a hipótese de que a paisagem mais a oeste – colonizada a partir de 1930 (Londrina e 1947 (Maringá – sofreu menor degradação antrópica, em comparação a paisagem, situada mais à leste (colonizada em meados do século XIX e início do século XX. Os resultados demonstraram que a hipótese inicial deve ser refutada. Fatores históricos e socioeconômicos influenciaram o modo de ocupação e conseqüentemente, a distribuição dos fragmentos florestais na paisagem.

  5. Comparison of N-nitrosodimethylamine formation mechanisms from dimethylamine during chloramination and ozonation: A computational study.

    Science.gov (United States)

    Liu, Yong Dong; Zhong, Rugang

    2017-01-05

    N-nitrosodimethylamine (NDMA) as a disinfection by-product has recently become the focus of considerable research interest due to its unusually high carcinogenicity. In this study, the formation mechanisms of NDMA from dimethylamine (DMA) during chloramination and ozonation were investigated by using the quantum chemical G4 method. The reactivity of haloamines and hydroxylamine reacting with DMA was found in the order: NHCl2∼NHBrCl (Br-leaving)>NHBr2>NH2Cl∼NH2Br>NH2OH. This offers a theoretical support for the experimentally proposed mechanism that dimethylamine reacts with NHCl2 rather than NH2Cl to form chlorinated unsymmetrical dimethylhydrazine intermediate and the existence of bromochloramine in the presence of bromide during chloramination, and explains the observation that NDMA yield during ozonation is much lower than that during chloramination. Importantly, an N,N-dimethylaminonitrene was found to be a significant intermediate to form NDMA in oxidation reactions by molecular oxygen and ozone. Additionally, results suggest that the amines containing the second nitrogen source directly connecting or close to the N-(CH3)2 moiety are potential significant NDMA precursors upon ozonation. The findings of this study are helpful for expanding the knowledge of NDMA formation mechanism, and predicting potential NDMA precursors during disinfection. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Photodegradation of antibiotics on soil surfaces: laboratory studies on sulfadiazine in an ozone-controlled environment.

    Science.gov (United States)

    Wolters, André; Steffens, Markus

    2005-08-15

    Among the processes affecting transport and degradation of antibiotics released to the environment during application of manure and slurry to agricultural land, photochemical transformations are of particular interest. Drying-out of the top soil layer under field conditions enables sorption of surface-applied antibiotics to soil dust, thus facilitating direct, indirect, and sensitized photodegradation at the soil/atmosphere interface. For studying various photochemical transformation processes of sulfadiazine, a photovolatility chamber designed in accordance with the requirements of the USEPA Guideline and 161-3 was used. Application of 14C-labeled sulfadiazine enabled complete mass balances and allowed for investigating the impact of various surfaces (glass and soil dust) and environmental factors, i.e., irradiation and atmospheric ozone, on photodegradation and volatilization. Volatilization was shown to be a negligible process. Even after increasing the air temperature up to 35 degrees C only minor amounts of sulfadiazine and transformation products (0.01-0.28% of applied radioactivity) volatilized. Due to direct and indirect photodegradation, the highest extent of mineralization to 14CO2 (3.9%), the formation of degradation products and of nonextractable soil residues was measured in irradiated soil dust experiments using ozone concentrations of 200 ppb. However, even in the dark significant mineralization was observed when ozone was present, indicating ozone-controlled transformation of sulfadiazine to occur at the soil surface.

  7. Pilot plant study on ozonation and biological activated carbon process for drinking water treatment

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study on advanced drinking water treatment was conducted in a pilot scale plant taking water from conventional treatment process. Ozonation-biological activated carbon process (O3-BAC) and granular activated carbon process (GAC) were evaluated based on the following parameters: CODMn, UV254, total organic carbon (TOC), assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC). In this test, the average removal rates of CODMn , UV254 and TOC in O3-BAC were18.2%, 9.0% and 10.2% higher on (AOC) than in GAC, respectively. Ozonation increased 19.3-57.6 μg Acetate-C/L in AOC-P17,45.6-130.6 μg Acetate-C/L in AOC-NOX and 0.1-0.5 mg/L in BDOC with ozone doses of 2-8 mg/L. The optimum ozone dose for maximum AOC formation was 3 mgO3/L. BAC filtration was effective process to improve biostability.

  8. Laser Spectroscopic Study on Oxygen Isotope Effects in Ozone Surface Decomposition

    Science.gov (United States)

    Minissale, Marco; Boursier, Corinne; Elandaloussi, Hadj; Te, Yao; Jeseck, Pascal; Rouille, Christian; Zanon-Willette, Thomas; Janssen, Christof

    2016-04-01

    The isotope kinetics of ozone formation in the Chapman reaction [1] O + O2 + M → O3 + M (1) provides the primary example for a chemically induced oxygen isotope anomaly and is associated with large [2] and mass independent [3] oxygen isotope enrichments in the product molecule, linked to a symmetry selection in the ozone formation kinetics [4-5]. The isotopic composition of ozone and its transfer to other molecules is a powerful tracer in the atmospheric and biogeochemical sciences [6] and serves as a primary model for a possible explanation of the oxygen isotopic heterogeneity in the Solar system [7-8]. Recently, the isotope fractionation in the photolytic decomposition process O3 + hν → O2 + O (2) using visible light has been studied in detail [9-10]. Much less is currently known about the isotope fractionation in the dry deposition or in the gas phase thermal decomposition of ozone O3 + M → O2 + O +M. (3) Here we report on first spectroscopic studies of non-photolytic ozone decomposition using a cw-quantum cascade laser at 9.5 μm. The concentration of individual ozone isotopomers (16O3,16O16O17O, and 16O17O16O) in a teflon coated reaction cell is followed in real time at temperatures between 25 and 150 °C. Observed ozone decay rates depend on homogeneous (reaction (3)) processes in the gas phase and on heterogeneous reactions on the wall. A preliminary analysis reveals agreement with currently recommended ozone decay rates in the gas phase and the absence of a large symmetry selection in the surface decomposition process, indicating the absence of a mass independent fractionation effect. This result is in agreement with previous mass spectrometer (MS) studies on heterogeneous ozone formation on pyrex [11], but contradicts an earlier MS study [12] on ozone surface decomposition on pyrex and quartz. Implications for atmospheric chemistry will be discussed. [1] Morton, J., Barnes, J., Schueler, B. and Mauersberger, K. J. Geophys. Res. 95, 901 - 907 (1990

  9. Aircraft laser infrared absorption spectrometer (ALIAS) for polar ozone studies

    Science.gov (United States)

    Webster, C. R.; May, R. D.

    1991-01-01

    The ALIAS instrument is a very high resolution (0.0003/cm) scanning, tunable diode laser spectrometer designed to make direct, simultaneous measurements of NO2, HNO3, HCl, CH4, and either O3 or N2O (including vertical profiles of CH4 and N2O) in the polar stratosphere at sub-part-per-billion level sensitivities over integration times from 3 to 30 s. Unique features include a sample inlet/throttle system designed to achieve near-isokinetic sampling, in PSC events, an in-flight wavelength reference cell rack, mechanical fringe-spoilers, a four-laser/four-detector dewar with 24-hr hold-time operating at a fixed temperature without electrical regulation, and in-flight fast correlation routines for spectral drift compensation prior to spectral addition. Instrument design and test flight results are discussed in the light of ALIAS's role in the Winter 1991 Arctic aircraft stratospheric ozone campaigns out of Fairbanks, Alaska, and Bangor, Maine.

  10. Impact of biogenic emissions on ozone formation in the Mediterranean area - a BEMA modelling study

    Science.gov (United States)

    Thunis, P.; Cuvelier, C.

    The aim of this modelling study is to understand and quantify the influence of biogenic volatile organic compound (BVOC) emissions on the formation of tropospheric ozone in the Burriana area (north of Valencia) on the east coast of Spain. The mesoscale modelling system used consists of the meteorology/transport module TVM and the chemical reaction mechanism RACM. The results of the model simulations are validated and compared with the data collected during the biogenic emissions in the mediterranean area (BEMA) field campaign that took place in June 1997. Anthropogenic and biogenic emission inventories have been constructed with an hourly resolution. Averaged (over the land area and over 24 h) emission fluxes for AVOC, anthropogenic NO x, BVOC and biogenic NO x are given by 16.0, 9.9, 6.2, and 0.7 kg km -2 day -1, respectively. The impact of biogenic emissions is investigated on peak ozone values by performing simulations with and without biogenic emissions, while keeping anthropogenic emissions constant. The impact on ozone formation is also studied in combination with some anthropogenic emissions reduction strategies, i.e. when anthropogenic VOC emissions and/or NO x emissions are reduced. A factor separation technique is applied to isolate the impact due to biogenic emissions from the overall impact due to biogenic and anthropogenic emissions together. The results indicate that the maximum impact of biogenic emissions on ozone formation represents at the most 10 ppb, while maximum ozone values are of the order of 100 ppb. At different locations the maximum impact is reached at different times of the day depending on the arrival time of the sea breeze. It is also shown that this impact does not coincide in time with the maximum simulated ozone concentrations that are reached over the day. By performing different emission reduction scenarios, BVOC impacts are found to be sensitive mainly to NO x, and not to AVOC. Finally, it is shown that amongst the various BVOCs

  11. A modeling study of the impact of urban trees on ozone

    Science.gov (United States)

    David J. Nowak; Kevin L. Civerolo; S. Trivikrama Rao; Gopal Sistla; Christopher J. Luley; Daniel E. Crane

    2000-01-01

    Modeling the effects of increased urban tree cover on ozone concentrations (July 13-15, 1995) from Washington, DC, to central Massachusetts reveals that urban trees generally reduce ozone concentrations in cities, but tend to increase average ozone concentrations in the overall modeling domain. During the daytime, average ozone reductions in urban areas (1 ppb) were...

  12. Indoor Secondary Pollutants from Household Product Emissions inthe Presence of Ozone: A Bench-Scale Chamber Study

    Energy Technology Data Exchange (ETDEWEB)

    Destaillats, Hugo; Lunden, Melissa M.; Singer, Brett C.; Coleman,Beverly K.; Hodgson, Alfred T.; Weschler, Charles J.; Nazaroff, William W.

    2005-10-01

    Ozone-driven chemistry is a major source of indoor secondary pollutants of health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and oxidation products were measured. Formaldehyde was a predominant oxidation byproduct for the three studied products, with yields under most conditions of 20-30% with respect to ozone consumed. Acetaldehyde, acetone, glycolaldehyde, formic acid and acetic acid were each also detected for two or three of the products. Immediately upon mixing of reactants, a scanning mobility particle sizer detected particle nucleation events that were followed by a significant degree of ultrafine particle growth. The production of secondary gaseous pollutants and particles depended primarily on the ozone level and was influenced by other parameters such as the air-exchange rate. Hydroxyl radical concentrations in the range 0.04-200 x 10{sup 5} molecules cm{sup -3} were measured. OH concentrations were observed to vary strongly with residual ozone level in the chamber, which was in the range 1-25 ppb, as is consistent with expectations from a simplified kinetic model. In a separate test, we exposed the dry residue of two products to ozone in the chamber and observed the formation of gas-phase and particle-phase secondary oxidation products.

  13. Nonlinear response of ozone to precursor emission changes in China: a modeling study using response surface methodology

    Directory of Open Access Journals (Sweden)

    J. Xing

    2011-05-01

    Full Text Available Statistical response surface methodology (RSM is successfully applied for a Community Multi-scale Air Quality model (CMAQ analysis of ozone sensitivity studies. Prediction performance has been demonstrated through cross validation, out-of-sample validation and isopleth validation. Sample methods and key parameters, including the maximum numbers of variables involved in statistical interpolation and training samples have been tested and selected through computational experiments. Overall impacts from individual source categories which include local/regional NOx and VOC emission sources and NOx emissions from power plants for three megacities – Beijing, Shanghai and Guangzhou – were evaluated using an RSM analysis of a July 2005 modeling study. NOx control appears to be beneficial for ozone reduction in the downwind areas which usually experience high ozone levels, and NOx control is likely to be more effective than anthropogenic VOC control during periods of heavy photochemical pollution. Regional NOx source categories are strong contributors to surface ozone mixing ratios in three megacities. Local NOx emission control without regional involvement may raise the risk of increasing urban ozone levels due to the VOC-limited conditions. However, local NOx control provides considerable reduction of ozone in upper layers (up to 1 km where the ozone chemistry is NOx-limited and helps improve regional air quality in downwind areas. Stricter NOx emission control has a substantial effect on ozone reduction because of the shift from VOC-limited to NOx-limited chemistry. Therefore, NOx emission control should be significantly enhanced to reduce ozone pollution in China.

  14. Study of air pollution: Effects of ozone on neuropeptide-mediated responses in human subjects. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boushey, H.A.

    1991-11-01

    The study examined the hypothesis that ozone inactivates the enzyme, neutral endopeptidase, responsible for limiting the effects of neuropeptides released from afferent nerve endings. Cough response of capsaicin solution delivered from a nebulizer at 2 min. intervals until two or more coughs were produced. Other endpoints measured included irritative symptoms as rated by the subjects on a nonparametric scale, spirometry, of each concentration of ozone were compared to those of filtered air in a single-blind randomized sequence. The results indicate that a 2 h. exposure to 0.4 ppm of ozone with intermittent light exercise alters the sensitivity of airway nerves that mediate the cough response to inhaled materials. This dose of ozone also caused a change in FEV1. A lower level of ozone, 0.02 ppm, caused a change in neither cough threshold nor FEV1, even when the duration of exposure was extended to three hours. The findings are consistent with the author's hypothesis that ozone may sensitize nerve endings in the airways by inactivating neutral endopeptidase, an enzyme that regulates their activity, but they do not demonstrate that directly examining an effect directly mediated by airway nerves allows detection of effects of ozone at doses below those causing effects detected by standard tests of pulmonary function.

  15. Interaction between hollow needles - electric field, light emission and ozone generation study in multineedle to plate electrical discharge

    Science.gov (United States)

    Kriha, Vitezslav

    2004-09-01

    Multi hollow needle to plate electrical discharges in air are studied as ozone sources. Dependence of ozone concentration as an function of applied voltage, discharge current, mutual hollow needles position and electrical connection, working gas flow rate, distances between needles tips and plate electrode, visible light emission was measured experimentally in these systems. Electric field was numerically modeled. Light emission and electrical field distributions were compared. Coming from light emission and electric field a model of energy density spatial distribution was built. This model was finally compared with ozone generation.

  16. Studies on degradation of glyphosate by several oxidative chemical processes: ozonation, photolysis and heterogeneous photocatalysis.

    Science.gov (United States)

    Assalin, Marcia R; De Moraes, Sandra G; Queiroz, Sonia C N; Ferracini, Vera L; Duran, Nelson

    2010-01-01

    Several different Advanced Oxidation Processes (AOPs) including ozonation at pH 6.5 and 10, photolysis and heterogeneous photocatalysis using TiO(2) as semiconductor and dissolved oxygen as electron acceptor were applied to study the degradation of glyphosate (N-phosphonomethyl glycine) in water. The degree of glyphosate degradation, the reactions kinetic and the formation of the major metabolite, aminomethyl phosphonic acid (AMPA), were evaluated. Ozonation at pH 10 resulted in the maximum mineralization of glyphosate. It was observed that under the experimental conditions used in this study the degradation of glyphosate followed the first-order kinetics. The half-life obtained for glyphosate degradation in the O(3)/pH 10 process was 1.8 minutes.

  17. Kinetics study on photochemical oxidation of polyacrylamide by ozone combined with hydrogen peroxide and ultraviolet radiation

    Institute of Scientific and Technical Information of China (English)

    REN Guang-meng; SUN De-zhi; CHUNG Jong Shik

    2006-01-01

    An investigation on the process of ozone combined with hydrogen peroxide and ultraviolet radiation has been carried out in order to establish the kinetics for photochemical oxidation of polyacrylamide (PAM) in aqueous solution. Effects of operating parameters, including initial PAM concentration, dosages of ozone and hydrogen peroxide, UV radiation and pH value on the photochemical oxidation of PAM, have been studied. There was an increase in photochemical oxidation rate of PAM with increasing of dosages of O3, H2O2 and ultraviolet radiation. Upon increasing of the initial PAM concentration, the photochemical oxidation rate of PAM decreased. Slight effect of pH value on the photochemical oxidation rate of PAM was observed in the experiments. The kinetics equation for the photochemical oxidation of PAM by the system has been established.

  18. Laboratory Studies of Chemical and Photochemical Processes Relevant to Stratospheric Ozone

    Science.gov (United States)

    Villalta, Peter W.; Zahniser, Mark S.; Nelson, David D.; Kolb, Charles E.

    1997-01-01

    The purpose of this project is to reduce the uncertainty in several key gas-phase kinetic processes which impact our understanding of stratospheric ozone. The main emphasis of this work is on measuring rate coefficients and product channels for reactions of HO(x) and NO(x) species in the temperature range 200 K to 240 K relevant to the lower stratosphere. The results of these studies will improve models of stratospheric ozone chemistry and predictions of perturbations due to human influences. The second year's effort has focussed the design and construction of the proposed high pressure flow reactor on three separate areas: (1) the construction of the high pressure flow reactor; (2) characterization of the turbulent flow profile; and (3) demonstration of the instrument by measuring HO2 + NO2 and HO2 + NO reaction rate coefficients.

  19. Surface Spectroscopy Studies of the Reactive Uptake of Ozone on Alkali Halides

    Science.gov (United States)

    Newberg, J. T.; Hemminger, J. C.

    2003-12-01

    Heterogeneous reactions in the atmosphere have attracted a lot of attention. In particular, reactions involving sea-salt in the form of aerosol droplets, particles, and/or sea-ice have been implicated to significantly affect the chemistry and composition of the marine boundary layer. For example, highly reactive chlorine and bromine atoms resulting from the oxidation of sea-salt halides (Cl- and Br-) have been implicated in tropospheric ozone depletion in the arctic and in lower latitude marine regions, as well as the deposition of mercury. While the heterogeneous processing of sea-salt has been studied extensively in laboratory, field and model studies, the mechanistic details behind the release of gas-phase halogens remains unclear and has sparked some interests. Recently there has been attention focused on the interaction of important atmospheric oxidants (e.g., OH and O3) with halides that reside at the air-particle interface of sea-salt. Such chemical interactions at the surface of particles may lead to unique chemical transformations that can alter current views of known chemical processing of sea-salt particles. There are several laboratory investigations which have investigated the surface reactivity of salts by measuring the reactive loss and/or formation of gas-phase species, indicating that reactions at the interface likely play an important role in aerosol chemistry. The efficacy of such surface-phase chemistry has yet to be elucidated with surface spectroscopy studies. X-ray photoelectron spectroscopy (XPS) is a surface spectroscopy technique with submonolayer resolution. Using XPS, we have investigated changes in the surface chemistry of various alkali halide salts upon exposure to ozone in an ultra-high vacuum (UHV) instrument. Salt samples were either freshly cleaved single crystals which were prepared from a melt, or purified salt crystals/powders pressed into pellets. Upon exposure to ozone, oxygen on the salt surfaces was monitored by measuring

  20. Ozone therapy in periodontics.

    Science.gov (United States)

    Gupta, G; Mansi, B

    2012-02-22

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics.

  1. Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

    Directory of Open Access Journals (Sweden)

    Z. A. Kanji

    2013-09-01

    Full Text Available Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T and relative humidity (RH, as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulfate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long-range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 T ns are reported and observed to increase as a function of decreasing temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. We also present the first results to show a suppression of heterogeneous ice nucleation activity without the condensation of a coating of (inorganic material. In immersion mode, low ozone exposed Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka, whereas high ozone exposed ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low exposure Ka had ice active fractions of an order of magnitude higher than untreated Ka, whereas high ozone exposed ATD had ice active fractions up to a factor of 4 lower than untreated ATD. From our results, we derive and present parameterizations in terms of ns(T that can be used in models to predict ice nuclei concentrations based on available aerosol surface area.

  2. Spectroscopic study of degradation products of ciprofloxacin, norfloxacin and lomefloxacin formed in ozonated wastewater.

    Science.gov (United States)

    Liu, Chen; Nanaboina, Venkateswarlu; Korshin, Gregory V; Jiang, Wenju

    2012-10-15

    This study addressed the formation and properties of degradation products of ciprofloxacin, norfloxacin and lomefloxacin formed during ozonation of secondary wastewater effluent containing these fluoroquinolone antibiotics. The generation of the degradation products was interpreted in the context of transformations of effluent organic matter (EfOM) tracked via absorbance measurements. The structures of 20 degradation products were elucidated for ciprofloxacin and norfloxacin, respectively. 27 degradation products were identified for lomefloxacin. The prevalent oxidation pathways were suggested based on the structures of the identified products formed in the absence and presence of the hydroxyl radical scavenger t-butanol. These pathways were largely similar for all studied fluoroquinolones and involved attacks on the piperazine ring and the quinolone structure. The quinolone ring remained intact in the presence of t-butanol thus indicating that this functional group could only be oxidized by OH radicals while the piperazine ring was readily oxidized by molecular ozone. The cleavage of the quinolone moiety that resulted in several identified degradation products occurred via the attack by hydroxyl radicals on the carbon-carbon double bond adjacent to the carboxylic acid group. Lomefloxacin had more diverse oxidation products due to the presence of a methyl group on its piperazinyl ring. The concentrations of the identified degradation products behaved non-monotonically as a function of ozone dose or treatment time, yet exhibited interpretable correlations versus changes of EfOM absorbance. Examination of these correlations allowed developing a novel approach for elucidating the transformations of fluoroquinolone antibiotics during ozonation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. SMM mesospheric ozone measurements

    Science.gov (United States)

    Aikin, A. C.

    1990-01-01

    The main objective was to understand the secular and seasonal behavior of ozone in the lower mesosphere, 50 to 70 km. This altitude region is important in understanding the factors which determine ozone behavior. A secondary objective is the study of stratospheric ozone in the polar regions. Use is made of results from the SBUV satellite borne instrument. In the Arctic the interaction between chlorine compounds and low molecular weight hydrocarbons is studied. More than 30,000 profiles were obtained using the UVSP instrument on the SMM spacecraft. Several orbits of ozone data per day were obtained allowing study of the current rise in solar activity from the minimum until the present. Analysis of Nimbus 7 SBUV data in Antarctic spring indicates that ozone is depleted within the polar vortex relative to ozone outside the vortex. This depletion confirms the picture of ozone loss at altitudes where polar stratospheric clouds exist. In addition, there is ozone loss above the cloud level indicating that there is another mechanism in addition to ozone loss initiated by heterogeneous chlorine reactions on cloud particles.

  4. A Comparative Study on Ozone Photochemical Formation in the Megacities of Tianjin and Shanghai, China

    Science.gov (United States)

    Ran, L.; Zhao, C.; Xu, W.; Geng, F.; Lu, X.; Han, M.; Lin, W.; Xu, X.

    2011-12-01

    As one of the most widespread and stubborn environmental issues, the ozone problem has been of particular concern for many years, given the potential adverse effects of high ozone concentrations on public health and agricultural productivity. In the past decades, rapid urbanization and industrialization have given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated megacities. Due to the highly nonlinear impacts of ozone precursors including nitrogen oxides (NOx) and various volatile organic compounds (VOCs) on ozone photochemistry, formation of ozone affected by different precursor emission patterns in those megacities has exhibited different characteristics. A comparative analysis of ozone photochemical production in the megacities of Tianjin and Shanghai has thus been carried out, using the data sets of surface ozone and its precursors measured respectively at an urban and a suburban site of the two megacities during the summertime. Observation-based analysis indicated an elevated ozone daily peak under photochemistry dominant conditions from the urban center to the suburb in both regions, nevertheless bearing different reasons. Ozone production was generally sensitive to VOCs in the Tianjin region, leading to a relatively higher level of ozone in the suburb where reactive VOCs were abundantly released from a number of industrial facilities, whereas a sensitivity of ozone production to NOx was found in Shanghai. The high level of NOx emitted mainly by motor vehicles in urban Shanghai largely inhibited ozone formation and resulted in a much more rapid decrease in ozone concentrations after reaching the daily maximum around midday compared with the other three areas. Ozone pollution in the megacity of Tianjin was more representative of the regional condition, implying that combined efforts would be needed to bring the ozone problem under control within this region. Improved understanding of

  5. Vertical Distributions of Ozone above the San Joaquin Valley Measured by the NOAA TOPAZ lidar during the California Baseline Ozone Transport Study

    Science.gov (United States)

    Langford, A. O.; Alvarez, R. J., II; Kirgis, G.; Senff, C. J.; Weickmann, A. M.

    2016-12-01

    The California Baseline Ozone Transport Study (CABOTS) was conducted in the late spring and summer of 2016 to investigate the influence of trans-boundary ozone (O3) on the surface concentrations in the San Joaquin Valley (SJV) of California, one of two "extreme" non-attainment areas remaining in the United States. As part of this study, the truck-based NOAA ESRL scanning ozone and aerosol lidar (TOPAZ) was deployed to the Visalia, CA Airport for two 3-week intensive operating periods: (May 29 - June 18) and (July 18-August 7). This site was selected to take advantage of the collocated radar wind profiler and RASS operated by the San Joaquin Valley Air Pollution Control District and the lidar measurements also overlapped with in situ sampling by the NASA Ames Alpha Jet (AJAX) and the UC Davis/Scientific Aviation Mooney aircraft. In addition, the lidar measurements coincided with daily ozonesonde launches at Bodega Bay and Half Moon Bay by San Jose State University. In this talk, I will provide an overview of the TOPAZ measurements, and discuss the impacts of stratosphere-to-troposphere transport (STT), long-range transport from Asia, and regional transport from the Los Angeles Basin on the measurements.

  6. Ozone reservoir layers in a coastal environment – a case study in southern Taiwan

    OpenAIRE

    Lin, C.-H.; Wu, Y.-L.; Lai, C. -H.

    2010-01-01

    The air layer between the nocturnal boundary layer and the top of the daily mixing layer in an ozone-polluted area is known to serve as an ozone reservoir since the ozone that is produced in the mixing layer on the preceding day is effectively preserved throughout the night in the air layer. Ozone reservoir layers existing at night can enhance the accumulation of surface ozone on the following day. However, our knowledge of the characteristics of ozone reservoir layers and their effects on th...

  7. Sensitivity Study of Cloud Cover and Ozone Modeling to Microphysics Parameterization

    Science.gov (United States)

    Wałaszek, Kinga; Kryza, Maciej; Szymanowski, Mariusz; Werner, Małgorzata; Ojrzyńska, Hanna

    2017-02-01

    Cloud cover is a significant meteorological parameter influencing the amount of solar radiation reaching the ground surface, and therefore affecting the formation of photochemical pollutants, most of all tropospheric ozone (O3). Because cloud amount and type in meteorological models are resolved by microphysics schemes, adjusting this parameterization is a major factor determining the accuracy of the results. However, verification of cloud cover simulations based on surface data is difficult and yields significant errors. Current meteorological satellite programs provide many high-resolution cloud products, which can be used to verify numerical models. In this study, the Weather Research and Forecasting model (WRF) has been applied for the area of Poland for an episode of June 17th-July 4th, 2008, when high ground-level ozone concentrations were observed. Four simulations were performed, each with a different microphysics parameterization: Purdue Lin, Eta Ferrier, WRF Single-Moment 6-class, and Morrison Double-Moment scheme. The results were then evaluated based on cloud mask satellite images derived from SEVIRI data. Meteorological variables and O3 concentrations were also evaluated. The results show that the simulation using Morrison Double-Moment microphysics provides the most and Purdue Lin the least accurate information on cloud cover and surface meteorological variables for the selected high ozone episode. Those two configurations were used for WRF-Chem runs, which showed significantly higher O3 concentrations and better model-measurements agreement of the latter.

  8. Long-term ambient ozone concentration and the incidence of asthma in nonsmoking adults: The Ahsmog study

    Energy Technology Data Exchange (ETDEWEB)

    McDonnell, W.F. [Environmental Protection Agency, Research Triangle Park, NC (United States). National Health and Environmental Effects Research Lab.; Abbey, D.E.; Nishino, N. [Loma Linda Univ., CA (United States). School of Public Health; Lebowitz, M.D. [Univ. of Arizona Coll. of Medicine, Tucson, AZ (United States).

    1999-02-01

    The authors conducted a prospective study of a cohort of 3091 nonsmokers, ages 27 to 87 years, to evaluate the association between long-term ambient ozone exposure and development of adult-onset asthma. Over a 15-year period, 3.2% of males and 4.3% of females reported new doctor diagnoses of asthma. For males, they observed a significant relationship between report of doctor diagnosis of asthma and 20-year mean 8-h average ambient ozone concentration. The authors observed no such relationship for females. Other variables significantly related to development of asthma were a history of ever-smoking for males, and for females, number of years worked with a smoker, age, and a history of childhood pneumonia or bronchitis. Addition of other pollutants to the models did not diminish the relationship between ozone and asthma for males. These data suggest that long-term exposure to ambient ozone is associated with development of asthma in adult males.

  9. Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

    Science.gov (United States)

    Kanji, Z. A.; Welti, A.; Chou, C.; Stetzer, O.; Lohmann, U.

    2013-09-01

    Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T) and relative humidity (RH), as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulfate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long-range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 < T < 263 K. Heterogeneous ice nucleation of untreated kaolinite (Ka) and Arizona Test Dust (ATD) particles is compared to corresponding aged particles that are subjected to ozone concentrations of 0.4-4.3 ppmv in a stainless steel aerosol tank. The portable ice nucleation counter (PINC) and immersion chamber combined with the Zurich ice nucleation chamber (IMCA-ZINC) are used to conduct deposition and immersion mode measurements, respectively. Ice active fractions as well as ice active surface site densities (ns) are reported and observed to increase as a function of decreasing temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. We also present the first results to show a suppression of heterogeneous ice nucleation activity without the condensation of a coating of (in)organic material. In immersion mode, low ozone exposed Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka, whereas high ozone exposed ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low

  10. Ozone damage to crops in southern Africa: An initial modeling study

    CSIR Research Space (South Africa)

    Zunckel, M

    2006-06-01

    Full Text Available The Cross Border Impact Assessment Project (CAPIA) was designed to develop an understanding of regional surface ozone concentrations and their potential risk to agriculture in southern Africa. Surface ozone concentrations were estimated using...

  11. Studies on the mechanism of ozone damage using the varigated leaf

    Energy Technology Data Exchange (ETDEWEB)

    Imaizumi, S.; Wada, Y.

    1971-03-01

    The distribution of green and white tissues within leaves was determined by examining free-hand cross-sections of varigated fresh leaves. It was apparent that ozone attacked not only palisade parenchyma cells but spongy cells. The first symptom of ozone damage was revealed to plasmolysis on mesophyll cells. The relation of the ozone damage to the photosynthetic system was discussed based on the experimental result that ozone particularly attacked the cells containing chloroplasts.

  12. A study of ozone in the surface layer of Kiev and its impact on the human health

    CERN Document Server

    Shavrina, A V; Kiforenko, S I; Sheminova, V A; Veles, A A; Blum, O B

    2012-01-01

    Ground-level ozone in Kiev for an episode of its high concentration in August 2000 was simulated with the model of the urban air pollution UAM-V (Urban Airshed Model). The study of total ozone over Kiev and its concentration changes with height in the troposphere is made on the basis of ground-based observations with the infrared Fourier spectrometer at the Main Astronomical Observatory of National Academy of Sciences of Ukraine as a part of the ESA-NIVR-KNMI no 2907. In 2008 the satellite Aura-OMI data OMO3PR on the atmosphere ozone profiles became available. Beginning in 2005, these data include the ozone concentration in the lower layer of the atmosphere and can be used for the evaluation of the ground-level ozone concentrations in all cities of Ukraine. Some statistical investigation of ozone air pollution in Kiev and medical statistics data on respiratory system was carried out with the application of the "Statistica" package. The regression analysis, prognostic regression simulation, and retrospective p...

  13. [A Study of Data From the Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) Mission

    Science.gov (United States)

    Newman, Paul A.; Fahey, David W.; Brune, William H.; Kurylo, Michael J.; Kawa, S. Randolph

    1999-01-01

    The Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) mission was designed to investigate the natural summer decrease of stratospheric ozone levels. Both polar regions have large and distinct annual cycles of ozone column amounts. In northern spring, the average level is over 450 Dobson units (DU), decreasing to less than 275 DU by September. In order to cover this period of ozone decrease, POLARIS was conducted in three deployment phases from Fairbanks, Alaska, (650N) during the summer of 1997. The principal measurement platforms were the NASA ER-2 high-altitude aircraft and stratospheric balloons. Additional measurements were provided by ground-based instruments, sondes, and satellites. POLARIS observations included ozone, meteorological variables, particles, long-lived chemicals, and short-lived radicals. During the field deployments, several modeling and theoretical groups participated in flight planning and data evaluation activities. The interpretive studies in this Special Section of the Journal of Geophysical Research are a first comprehensive examination of the POLARIS data set, addressing stratospheric ozone abundances and its changes; the role of aerosols; details of the photochemistry of reactive species; transport of stratospheric air and the correlations of long-lived species; and measurement intercomparisons.

  14. A kinetic study of the reaction of ozone with ethylene in a smog chamber under atmospheric conditions

    Institute of Scientific and Technical Information of China (English)

    XU Yongfu; JIA Long; GE Maofa; DU Lin; WANG Gengchen; WANG Dianxun

    2006-01-01

    Ozone is one of the key species in the processes of atmospheric chemistry, which can be taken as an indicator of oxidation capacity in the troposphere, The reaction of ozone with reactive gases is an important process in the troposphere. Experimental simulation equipment of smog chamber for atmospheric reactions is used to study the reaction of ozone with ethylene in real atmospheric environment with ozone concentrations of 100-200 ppb. The concentrations of ozone and ethylene were monitored during the reaction with the combination of Model 49C-O3 Analyzer and GC-FID. A rate constant of 1.01×10-18 (cm3.mol-1.s-1) was obtained at 286.5 K,under condition of which the half-life of ozone was 88 min. The results obtained from our experiments are in excellent agreement with those reported previously by other researchers under extremely Iow pressure in terms of matrix-isolation technology. This demonstrates that our equipment of smog chamber for atmospheric reactions is reliable, which can be used for further research of the processes of atmospheric reactions.

  15. Laboratory studies on the effect of ozonation on THM formation in swimming pool water

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Cheema, Waqas Akram

    2015-01-01

    Water samples from indoor swimming pool were ozonated at different pH values to evaluate the effect of pH on decomposition of ozone in swimming pool water. Furthermore, drinking and pool water were repeatedly ozonated followed by chlorination to evaluate THM formation. Decomposition of ozone...... was not affected by pH in the range relevant to swimming pools (pH 6.8 – 7.8) and a half-life time at 10-12 min was obtained. Repeating the ozonation, the decomposition of ozone increased at the second dose of ozone added (t½,2=8 min) and then decreased again at the third and fourth dose of ozone (t½,3=17 min; t...... chlorine for drinking water as lower TTHM formation occurred than in non-ozonated samples. For pool water, a higher TTHM formation was observed in ozonated than non-ozonated pool water. Thus, it was observed that ozone reacts markedly different in swimming pool water from the known pattern in drinking...

  16. Ozonation for source treatment of pharmaceuticals in hospital wastewater - ozone lifetime and required ozone dose

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Chhetri, Ravi Kumar

    2016-01-01

    Ozonation aimed at removing pharmaceuticals was studied in an effluent from an experimental pilot system using staged moving bed biofilm reactor (MBBR) tanks for the optimal biological treatment of wastewater from a medical care unit of Aarhus University Hospital. Dissolved organic carbon (DOC......) and pH in samples varied considerably, and the effect of these two parameters on ozone lifetime and the efficiency of ozone in removing pharmaceuticals were determined. The pH in the effluent varied from 5.0 to 9.0 resulting in approximately a doubling of the required ozone dose at the highest p......H for each pharmaceutical. DOC varied from 6 to 20 mg-DOC/L. The ozone required for removing each pharmaceutical, varied linearly with DOC and thus, ozone doses normalized to DOC (specific ozone dose) agreed between water samples (typically within 15%). At neutral pH the specific ozone dose required...

  17. Study on the formation and transport of ozone in relation to the air quality management and vegetation protection in Tenerife (Canary Islands).

    Science.gov (United States)

    Guerra, Juan-Carlos; Rodríguez, Sergio; Arencibia, M-Teresa; García, M-Dolores

    2004-09-01

    An experimental study on the formation and transport of ozone in ambient air was performed in Tenerife (Canary Islands) in order to investigate the processes affecting ozone levels and air quality. The special features of Tenerife (prevalence of the trade wind pattern (NE), orography and the specific location of the local ozone sources) permit to quantify the role of the 'long-range transport from northern latitudes' versus the 'formation and transport of ozone downwind of the main urban areas' of Tenerife. Levels of O(3), NO(2) and O(X) were monitored in different types of environments to achieve this purpose. The results showed that: (1) upwind of the urban areas ozone is mainly transported from the ocean by trade winds, (2) local ozone titration (by NO) and ozone replenishment from the ocean are the main causes of ozone variations in urban and suburban areas, and (3) photochemical ozone production occurs downwind of the urban areas. Photochemical production causes daylight O(3) and O(X) levels downwind of urban areas to be frequently (60% and 35% days/year, respectively) higher than upwind of the urban sites (O(3) and O(X) excess frequently in the range 5-20 ppbv). Due to the above processes, different daily ozone cycles occur in short distances (Tenerife.

  18. Ozonated Olive Oils and Troubles

    Directory of Open Access Journals (Sweden)

    Bulent Uysal

    2014-04-01

    Full Text Available One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. [J Intercult Ethnopharmacol 2014; 3(2.000: 49-50

  19. Use of pulse radiolysis for the study of the chemistry of aqueous ozone and ozonide solutions

    DEFF Research Database (Denmark)

    Sehested, Knud; Holcman, Jerzy; Bjergbakke, Erling

    1986-01-01

    The chemistry of aqeous ozone, O3, and ozonide, O3−, is of great interest from a technological, environmental and scientific point of view. The literature about their aqueous chemistry is extensive, the reaction mechanisms are still not well understood. The ozonide anion is a free radical...... of a detailed mechanism. We have investigated the reaction mechanisms using pulse radiolysis in combination with a high pressure cell, rapid mixing and numerical simulation of the experiments. This study makes it possible to give a detailed description of the reaction mechanisms in terms of uni- and bimolecular...... reactions and provides kinetic data sufficient for computer simulations of aqueous O3/O3− chemistry....

  20. Ozone exposure, vitamin C intake, and genetic susceptibility of asthmatic children in Mexico City: a cohort study

    Directory of Open Access Journals (Sweden)

    Moreno-Macías Hortensia

    2013-02-01

    Full Text Available Abstract Background We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF25-75 in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1, GSTP1 (rs1695, and NQO1 (rs1800566. Methods 257 asthmatic children from two cohort studies conducted in Mexico City were included. Stratified linear mixed models with random intercepts and random slopes on ozone were used. Potential confounding by ethnicity was assessed. Analyses were conducted under single gene and genotype score approaches. Results The change in FEF25-75 per interquartile range (60 ppb of ozone in persistent asthmatic children with low vitamin C intake and GSTM1 null was −91.2 ml/s (p = 0.06. Persistent asthmatic children with 4 to 6 risk alleles and low vitamin C intake showed an average decrement in FEF25-75 of 97.2 ml/s per 60 ppb of ozone (p = 0.03. In contrast in children with 1 to 3 risk alleles, acute effects of ozone on FEF25-75 did not differ by vitamin C intake. Conclusions Our results provide further evidence that asthmatic children predicted to have compromised antioxidant defense by virtue of genetic susceptibility combined with deficient antioxidant intake may be at increased risk of adverse effects of ozone on pulmonary function.

  1. Reactivity of NiO for 2,4-D degradation with ozone: XPS studies.

    Science.gov (United States)

    Rodríguez, Julia L; Valenzuela, Miguel A; Poznyak, Tatiana; Lartundo, Luis; Chairez, Isaac

    2013-11-15

    2,4-Dichlorophenoxyacetic acid (2,4-D) is usually used as a refractory model compound that requires a prolonged reaction time for mineralization. In this study, we found that nickel oxide (NiO) significantly improved 2,4-D degradation and mineralization in reaction with ozone. Other metal oxides, such as titania, silica and alumina, were also tested in this reaction, so that, the mineralization degree was almost the same for all of them (ca. 25%), whereas NiO showed more than 60% in 1h. These outstanding results led us to study in more depth the role of NiO as catalyst in the degradation of 2,4-D. For instance, the optimum NiO loading amount was 0.3 g L(-1). The catalytic ozonation showed a high stability after three reaction cycles. With the aim of identifying the surface species responsible for the high activity of NiO, besides knowing the byproducts during the degradation of 2,4-D, XPS and HPLC were mainly used as analytical tools. According to the results, the mineralization of 2,4-D was directly influenced by the adsorbed chlorate organic compounds and oxalate group onto NiO. Therefore, NiO plays a true role as a catalyst forming surface compounds which are subsequently decomposed causing an increase in the mineralization efficiency. In addition, it was possible to identify several degradation byproducts (2,4-diclorophenol, glycolic, fumaric, maleic and oxalic acids) that were included in a rational reaction pathway. It was proposed that 2,4-D elimination in presence of NiO as catalyst is a combination of processes such as: conventional ozonation, indirect mechanism (OH) and surface complex formation.

  2. A general circulation model study of the climatic effect of observed stratospheric ozone depletion between 1980 and 1990

    Science.gov (United States)

    Dudek, Michael P.; Wang, Wei-Chyung; Liang, Xin-Zhong; Li, Zhu

    1994-01-01

    The total ozone mapping spectrometer (TOMS) and stratospheric aerosol and gas experiment (SAGE) measurements show a significant reduction in the stratospheric ozone over the middle and high latitudes of both hemispheres between the years 1979 and 1991 (WMO, 1992). This change in ozone will effect both the solar and longwave radiation with climate implications. However, recent studies (Ramaswamy et al., 1992; WMO, 1992) indicate that the net effect depends not only on latitudes and seasons, but also on the response of the lower stratospheric temperature. In this study we use a general circulation model (GCM) to calculate the climatic effect due to stratospheric ozone depletion and compare the effect with that due to observed increases of trace gases CO2, CH4, N2O, and CFC's for the period 1980-1990. In the simulations, we use the observed changes in ozone derived from the TOMS data. The GCM used is a version of the NCAR community climate model referenced in Wang et al. (1991). For the present study we run the model in perpetual January and perpetual July modes in which the incoming solar radiation and climatological sea surface temperatures are held constant.

  3. A study of the sensitivity of stratospheric ozone to hypersonic aircraft emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kinnison, D.E.; Wuebbles, D.J.; Johnston, H.S.

    1988-09-01

    There recently has been new interest in the development of faster and more efficient aircraft for intercontinental passenger flights. Such aircraft would likely spend a high fraction of their flight time in the stratosphere. As a natural progression from studies that were done during the CIAP Program in the mid 1970s, this study investigates the sensitivity of stratospheric ozone to NO/sub x/ and HO/sub x/ emissions in conjunction with current understanding of atmospheric chemical and physical processes. The LLNL one-dimensional and two-dimensional chemical-radiative-transport models of the troposphere and stratosphere are used in this investigation. Because of the significant uncertainties in possible future emissions, it is necessary that we examine the models sensitivity to a wide range in magnitude, altitude, and latitude of assumed emissions. As well as examining different NO/sub x/ and HO/sub x/ emission levels, attempts are also made to examine the sensitivity of ozone to emissions under different background amounts of stratospheric chlorine (CIX). These studies lay the groundwork for future studies aimed at analyses of more realistic aircraft emission scenarios.

  4. A study of polar ozone depletion based on sequential assimilation of satellite data from the ENVISAT/MIPAS and Odin/SMR instruments

    Directory of Open Access Journals (Sweden)

    J. D. Rösevall

    2007-01-01

    Full Text Available The objective of this study is to demonstrate how polar ozone depletion can be mapped and quantified by assimilating ozone data from satellites into the wind driven transport model DIAMOND, (Dynamical Isentropic Assimilation Model for OdiN Data. By assimilating a large set of satellite data into a transport model, ozone fields can be built up that are less noisy than the individual satellite ozone profiles. The transported fields can subsequently be compared to later sets of incoming satellite data so that the rates and geographical distribution of ozone depletion can be determined. By tracing the amounts of solar irradiation received by different air parcels in a transport model it is furthermore possible to study the photolytic reactions that destroy ozone. In this study, destruction of ozone that took place in the Antarctic winter of 2003 and in the Arctic winter of 2002/2003 have been examined by assimilating ozone data from the ENVISAT/MIPAS and Odin/SMR satellite-instruments. Large scale depletion of ozone was observed in the Antarctic polar vortex of 2003 when sunlight returned after the polar night. By mid October ENVISAT/MIPAS data indicate vortex ozone depletion in the ranges 80–100% and 70–90% on the 425 and 475 K potential temperature levels respectively while the Odin/SMR data indicates depletion in the ranges 70–90% and 50–70%. The discrepancy between the two instruments has been attributed to systematic errors in the Odin/SMR data. Assimilated fields of ENVISAT/MIPAS data indicate ozone depletion in the range 10–20% on the 475 K potential temperature level, (~19 km altitude, in the central regions of the 2002/2003 Arctic polar vortex. Assimilated fields of Odin/SMR data on the other hand indicate ozone depletion in the range 20–30%.

  5. Estonian total ozone climatology

    Directory of Open Access Journals (Sweden)

    K. Eerme

    Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

    Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology

  6. Assessment of Solid Waste Management Strategies in Camarines Norte, Philippines

    OpenAIRE

    Maria Cristina C. Azuelo; Leah N. Barbado; Luz Menda L. Reyes

    2016-01-01

    The Ecological Solid Waste Management Act of 2000 or RA 9003 mandates the local government units to take initiatives in managing their daunting problems on ecological solid waste disposal. Consequently, compliance of Camarines Norte, Philippines on this mandate needs assessment to determine the existing solid waste management (SWM) strategies, the effectiveness and the possibility of adoption in each municipality. This study utilized the descriptive method using questionnaire as t...

  7. Measurement of Ozone Production Sensor

    Directory of Open Access Journals (Sweden)

    M. Cazorla

    2010-05-01

    Full Text Available A new ambient air monitor, the Measurement of Ozone Production Sensor (MOPS, measures directly the rate of ozone production in the atmosphere. The sensor consists of two 11.3 L environmental chambers made of UV-transmitting Teflon film, a unit to convert NO2 to O3, and a modified ozone monitor. In the sample chamber, flowing ambient air is exposed to the sunlight so that ozone is produced just as it is in the atmosphere. In the second chamber, called the reference chamber, a UV-blocking film over the Teflon film prevents ozone formation but allows other processes to occur as they do in the sample chamber. The air flows that exit the two chambers are sampled by an ozone monitor operating in differential mode so that the difference between the two ozone signals, divided by the exposure time in the chambers, gives the ozone production rate. High-efficiency conversion of NO2 to O3 prior to detection in the ozone monitor accounts for differences in the NOx photostationary state that can occur in the two chambers. The MOPS measures the ozone production rate, but with the addition of NO to the sampled air flow, the MOPS can be used to study the sensitivity of ozone production to NO. Preliminary studies with the MOPS on the campus of the Pennsylvania State University show the potential of this new technique.

  8. Pitfalls of Intralesional Ozone Injection in Diabetic Foot Ulcers: A Case Study

    OpenAIRE

    Uzun, Günalp; Mutluoğlu, Mesut; Karagöz, Hüseyin; Memiş, Ali; Karabacak, Ercan; Ay, Hakan

    2014-01-01

    Although the history of ozone therapy dates back to the 19th century, its use has shown a rapid growth of interest in recent decades. Intralesional ozone injection is seldom performed and its safety has not yet been reliably assessed for the treatment of diabetic foot wounds. Herein, we describe a diabetic patient who developed severe foot necrosis and infection after receiving intralesional ozone injections for a non-healing wound.

  9. Pitfalls of Intralesional Ozone Injection in Diabetic Foot Ulcers: A Case Study.

    Science.gov (United States)

    Uzun, Günalp; Mutluoğlu, Mesut; Karagöz, Hüseyin; Memiş, Ali; Karabacak, Ercan; Ay, Hakan

    2012-12-01

    Although the history of ozone therapy dates back to the 19th century, its use has shown a rapid growth of interest in recent decades. Intralesional ozone injection is seldom performed and its safety has not yet been reliably assessed for the treatment of diabetic foot wounds. Herein, we describe a diabetic patient who developed severe foot necrosis and infection after receiving intralesional ozone injections for a non-healing wound.

  10. Ozone, Iodine, and MSA - Case studies in Antarctic aerosol composition from the 2ODIAC Campaign

    Science.gov (United States)

    Giordano, M.; Kalnajs, L.; Deshler, T.; Davis, S. M.; Johnson, A.; Slater, A. G.; Goetz, J. D.; Mukherjee, A. D.; DeCarlo, P. F.

    2015-12-01

    Aerosol generation and transport over the Polar Regions, and especially Antarctica, remains a source of uncertainty for geophysical scientists. A characterization of aerosol sources, production, and lifecycle processes in the Polar Regions is required to better understand the polar atmosphere. In an attempt to better characterize Antarctic aerosol and trace gas interactions, the Two-Season, Ozone Depletion and Interaction with Aerosols Campaign (2ODIAC) was launched over the Austral Spring/Summer of 2014 and Austral Winter of 2015. One highlight of the campaign is the first ever deployment of a high-resolution aerosol mass spectrometer to Antarctica. In conjunction with trace gas, meteorology, and aerosol sizing measurements, this presentation will focus on case studies from the campaign relevant to the atmospheric science community. Questions about the role of iodine, MSA, and ozone depletion events in regards to aerosol composition will be examined. Specific attention will be paid to aerosol compositional changes before, during, and after particle bursts especially where changes in aerosol sulfate oxidation occurred (SO2 -> SO4)

  11. Plant cell death and cellular alterations induced by ozone: Key studies in Mediterranean conditions

    Energy Technology Data Exchange (ETDEWEB)

    Faoro, Franco, E-mail: franco.faoro@unimi.i [Istituto di Patologia Vegetale, Universita di Milano and CNR, Istituto di Virologia Vegetale, U.O.T di Milano, Via Celoria 2, 20133 Milan (Italy); Iriti, Marcello [Istituto di Patologia Vegetale, Universita di Milano and CNR, Istituto di Virologia Vegetale, U.O.T di Milano, Via Celoria 2, 20133 Milan (Italy)

    2009-05-15

    An account of histo-cytological and ultrastructural studies on ozone effect on crop and forest species in Italy is given, with emphasis on induced cell death and the underlying mechanisms. Cell death phenomena possibly due to ambient O{sub 3} were recorded in crop and forest species. In contrast, visible O{sub 3} effects on Mediterranean vegetation are often unclear. Microscopy is thus suggested as an effective tool to validate and evaluate O{sub 3} injury to Mediterranean vegetation. A DAB-Evans blue staining was proposed to validate O{sub 3} symptoms at the microscopic level and for a pre-visual diagnosis of O{sub 3} injury. The method has been positively tested in some of the most important crop species, such as wheat, tomato, bean and onion and, with some restriction, in forest species, and it also allows one to gain some very useful insights into the mechanisms at the base of O{sub 3} sensitivity or tolerance. - Ozone-induced cell death is a frequent phenomenon in Mediterranean conditions, not only in the most sensitive crops but also in forest species.

  12. Experimental study on oxidative decomposition of nitrobenzene in aqueous solution by honeycomb ceramic-catalyzed ozonation

    Institute of Scientific and Technical Information of China (English)

    Lei ZHAO; Jun MA; Zhizhong SUN; Zhengqian LIU; Yixin YANG

    2008-01-01

    The ozonation of nitrobenzene in aqueous solu-tion was carried out in a semi-batch reactor to investigate the degradation efficiency, the effect factors, and the reaction mechanism, where honeycomb ceramic was used as a cata-lyst. The presence of honeycomb ceramic could improve the degradation rate of nitrobenzene by 15.46% compared to the results ofozonation alone. Under the conditions of this exper-iment, the degradation rate of honeycomb ceramic-catalyzed ozonation increased by 12.94% with the increase of the amount of catalyst from 1 to 5 blocks. The degradation rates all increased greatly with the increase of temperature and pH of the solution in the processes of honeycomb ceramic-catalyzed ozonation and ozonation alone. But, when the pH of the solution increased to 9.50, the advantage of the honey-comb ceramic-catalyzed ozonation process would be lost. The experimental findings indicated that in the processes of ozonation alone and honeycomb ceramic-catalyzed ozona-tion, nitrobenzene was primarily oxidized by·OH free radical in aqueous solution. The adsorption of nitrobenzene was too limited to have an important influence on the degradation rate of nitrobenzene. With the same total dosage of applied ozone, the multiple step addition of ozone showed much higher removal efficiency than that obtained by one step in the two processes.

  13. Intoxicação por exposição à rapadura em três municípios do Rio Grande do Norte, Brasil: uma investigação de epidemiologia de campo Intoxication due to exposure to contaminated molasses ("rapadura" in three municipalities of the Brazilian state of Rio Grande do Norte: a field epidemiology study

    Directory of Open Access Journals (Sweden)

    Daniel Marques Mota

    2011-09-01

    Full Text Available O estudo objetivou descrever dois surtos de intoxicação por exposição à rapadura, ocorridos em três municípios do estado do Rio Grande do Norte, entre janeiro e fevereiro de 2008. Foi conduzida uma investigação epidemiológica com a realização de estudo de caso. Outras investigações, laboratorial e ambiental, complementaram o quadro de informações sobre os surtos. Foram oito casos prováveis por exposição à rapadura, dos quais cinco por consumo do produto (um evoluiu para óbito e três por proximidade física. As manifestações clínicas foram compatíveis com intoxicação por organofosforados. Outros sintomas apresentados podem estar relacionados com a presença de SO2, como rouquidão, lacrimejamento, dor nos olhos e ulceração corneana. A acetilcolinesterase eritrocitária resultou alterada para um dos pacientes que consumiu rapadura. Ocorreram dois surtos de intoxicação exógena: um por circunstância acidental e o outro, em decorrência do primeiro, por intoxicação ocupacional, cujo alimento implicado foi a rapadura contaminada com metamidofós e sulfito (SO2. A quantidade de metamidofós presente na rapadura consumida por dois casos foi 3.000 vezes maior que a ingestão diária aceitável para essa substância em humanos. Recomendam-se a adoção de medidas de saúde pública com a finalidade de minimizar a incidência de casos de intoxicação exógena e problemas decorrentes e prevenir surtos ocasionados por substâncias químicas, como as investigadas neste estudo.This study describes two poisoning outbreaks due to exposure to contaminated molasses in three municipalities of the state of Rio Grande do Norte (Northeastern Brazil between January and February 2008. Epidemiological investigation was conducted and a case study was carried out. Complementary laboratory and environmental investigations were performed to confirm outbreaks information. Eight cases were probably caused by exposure to contaminated

  14. Infrared matrix isolation and theoretical studies of reactions of ozone with bicyclic alkenes: α-pinene, norbornene, and norbornadiene.

    Science.gov (United States)

    Kugel, Roger W; Ault, Bruce S

    2015-01-15

    The reactions of ozone with three bicyclic alkenes, α-pinene, norbornene, and norbornadiene, were studied by low-temperature (14 K), argon matrix isolation infrared spectroscopy including (18)O isotope-labeling studies. Theoretical calculations of some of the proposed reaction intermediates and products were carried out using the Gaussian 09 suite of programs, applying density functional theory (DFT), the B3LYP functional, and the 6-311G++(d,2p) basis set. In the α-pinene/ozone system, the thermal reaction between α-pinene and ozone was too slow to observe under the twin-jet or merged-jet deposition conditions of these experiments. However, red light (λ ≥ 600 nm) irradiation of the argon matrixes containing α-pinene and ozone caused new infrared peaks to appear that could be readily assigned to reaction products of α-pinene with O((3)P) resulting from ozone photolysis: α-pinene oxide (with an epoxide ring) and two isomeric ketones. Norbornene and norbornadiene were both found to react with ozone in the gas phase during twin-jet or merged-jet deposition of these mixtures with argon. New peaks observed in the infrared spectra were assigned to the primary ozonides, Criegee intermediates, and secondary ozonides of norbornene and norbornadiene, indicating that the bulk of these reactions proceeded via the "classic" Criegee mechanism for ozonolysis of alkenes. Calculated infrared frequencies and molecular energies support these conclusions. Ultraviolet irradiation of these mixtures resulted in complete decomposition of the early intermediates and the formation of acids, aldehydes, alcohols, carbon dioxide, and carbon monoxide. In any case, no evidence for "unusual" chemistry, prompted by the bicyclic nature of the reactants, was observed.

  15. [Study on mechanism of ceramic honeycomb-catalytic ozonation for the decomposition of trace nitrobenzene in aqueous solution].

    Science.gov (United States)

    Zhao, Lei; Ma, Jun; Sun, Zhi-Zhong; Liu, Zheng-Qian; Yang, Yi-Xin; Lu, Wei

    2007-02-01

    The experiment investigated effects of the presence of hydroxyl radical inhibitor on degradation efficiency of trace nitrobenzene in aqueous solution in the processes of ozonation alone and ceramic honeycomb-catalyzed ozonation, including HCO3-, CO3(2-), HPO4(2-), H2PO4- and tert-butanol, and studied preliminarily on their mechanism. The results indicated that degradation rate of the two processes both increased firstly and decreased subsequently with the increase of the concentration of HCO3- (0 - 200 mg x L(-1)), and reached the climax at the concentration of bicarbonate ion 50 mg x L(-1) under the same experimental condition. The degradation rates of ozonation alone and ozonation/ ceramic honeycomb both declined by 16.57% and 27.52% with the increase of the concentration of CO3(2-) (0 - 20 mg x L(-1)), respectively, and decreased by 13.61% and 17.52% with the addition of the concentration of HPO4(2-) (0 - 12 mg x L(-1)), and reduced by 6.61% and 12.52% with the enhancement of the concentration of H2PO4- (0 - 120 mg x L(-1)), and dropped by 30.06% and 46.09% with the increasing of the concentration of tert-butanol (0 - 10 mg x L(-1)). The experimental results indicated that decomposition of nitrobenzene in both processes all followed the mechanism of oxidization by OH free radical, and tert-butanol is a more suitable indicator for the radical type reaction. The removal rate of ozonation alone rose with the increase of the concentration of pH (3.02 - 10.96), but that of ozonation/ceramic honeycomb process reached the maximum at pH = 9.23.

  16. Treatment effect of ozone and fluoride varnish application on occlusal caries in primary molars: a 12-month study.

    Science.gov (United States)

    Johansson, E; van Dijken, J W V; Karlsson, L; Andersson-Wenckert, I

    2014-09-01

    The aim of this study is to evaluate the effect of ozone and fluoride varnish on occlusal caries in primary molars in a split-mouth study. Caries risk was estimated by treating Public Dental Health Service dentists. Children with occlusal caries with Ekstrand index scores ≤3 (VI ≤3) were included. Selection of caries lesions was discontinued for ethical reasons due to non-acceptable clinical results during the follow-up. In the continued evaluation pairs of teeth with non-cavitated caries lesions, Ekstrand score ≤2a (VI ≤2) were selected. Fifty pairs of carious primary molars were included, 18 boys and 15 girls (mean 4.7 years, range 3-8). At baseline, the lesions were assessed by visual inspection (VI) and laser-induced fluorescence (LF), in each pair to treatment with 40 s ozone (HealOzone(TM), 2,100 ppm) or fluoride varnish Duraphat®. The treatments and evaluations were repeated at 3, 6 9 months and evaluations only at 12 months. Medium-high caries risk was observed in VI ≤3 children and low-medium risk in VI ≤2a children. In the 15 pairs VI ≤3 lesions, 8 treated with ozone and 9 with fluoride progressed to failure. In the 35 pairs VI ≤2a lesions, one lesion failed. Median baseline LF values in the VI ≤3 group were 76 and 69, for ozone and fluoride lesions, respectively, and 21 and 19 in the VI ≤2a group. At 12 months, LF values in the VI ≤2a group were 15 and 18. No improvement or difference in LF values was found over time between the caries lesions treated with ozone or fluoride. Neither ozone nor fluoride varnish treatments stopped the progression of caries in cavitated lesions. In low and medium caries risk children, non-cavitated lesions following both treatments showed slight or no progression. The use of ozone or fluoride varnish treatments in this regime as caries preventive method, added to the daily use of fluoridated toothpaste, to arrest caries progression in primary molars must therefore be questioned.

  17. Studies of Arctic Tropospheric Ozone Depletion Events Through Buoy-Borne Observations and Laboratory Studies

    Science.gov (United States)

    Halfacre, John W.

    The photochemically-induced destruction of ground-level Arctic ozone in the Arctic occurs at the onset of spring, in concert with polar sunrise. Solar radiation is believed to stimulate a series of reactions that cause the production and release of molecular halogens from frozen, salty surfaces, though this mechanism is not yet well understood. The subsequent photolysis of molecular halogens produces reactive halogen atoms that remove ozone from the atmosphere in these so-called "Ozone Depletion Events" (ODEs). Given that much of the Arctic region is sunlit, meteorologically stable, and covered by saline ice and snow, it is expected that ODEs could be a phenomenon that occurs across the entire Arctic region. Indeed, an ever-growing body of evidence from coastal sites indicates that Arctic air masses devoid of O3 most often pass over sea ice-covered regions before arriving at an observation site, suggesting ODE chemistry occurs upwind over the frozen Arctic Ocean. However, outside of coastal observations, there exist very few long-term observations from the Arctic Ocean from which quantitative assessments of basic ODE characteristics can be made. This work presents the interpretation of ODEs through unique chemical and meteorological observations from several ice-tethered buoys deployed around the Arctic Ocean. These observations include detection of ozone, bromine monoxide, and measurements of temperature, relative humidity, atmospheric pressure, wind speed, and wind direction. To assess whether the O-Buoys were observing locally based depletion chemistry or the transport of ozone-poor air masses, periods of ozone decay were interpreted based on current understanding of ozone depletion kinetics, which are believed to follow a pseudo-first order rate law. In addition, the spatial extents of ODEs were estimated using air mass trajectory modeling to assess whether they are a localized or synoptic phenomenon. Results indicate that current understanding of the

  18. Modelling cloud effects on ozone on a regional scale : A case study

    NARCIS (Netherlands)

    Matthijsen, J.; Builtjes, P.J.H.; Meijer, E.W.; Boersen, G.

    1997-01-01

    We have investigated the influence of clouds on ozone on a regional scale (Europe) with a regional scale photochemical dispersion model (LOTOS). The LOTOS-model calculates ozone and other photo-oxidant concentrations in the lowest three km of the troposphere, using actual meteorologic data and emiss

  19. A model study of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001)

    NARCIS (Netherlands)

    Roelofs, GJ; Scheeren, HA; Heland, J; Ziereis, H; Lelieveld, J

    2003-01-01

    A coupled tropospheric chemistry-climate model is used to analyze tropospheric ozone distributions observed during the MINOS campaign in the eastern Mediterranean region ( August, 2001). Modeled ozone profiles are generally in good agreement with the observations. Our analysis shows that the atmosph

  20. Ozone and nitrogen dioxide. A study on mechanisms of toxic action and cellular defense.

    NARCIS (Netherlands)

    Rietjens, I.M.C.M.

    1986-01-01

    Ozone and nitrogen dioxide are major toxic components of photochemical smog. They arise from the combustion of fossil fuels (traffic, industrial processes) and from solar radiation-catalyzed reactions in polluted atmospheres.The morphological, physiological and biochemical effects of ozone and nitro

  1. A model study of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001)

    NARCIS (Netherlands)

    Roelofs, GJ; Scheeren, HA; Heland, J; Ziereis, H; Lelieveld, J

    2003-01-01

    A coupled tropospheric chemistry-climate model is used to analyze tropospheric ozone distributions observed during the MINOS campaign in the eastern Mediterranean region ( August, 2001). Modeled ozone profiles are generally in good agreement with the observations. Our analysis shows that the

  2. The use of ozone-treated blood in the therapy of HIV infection and immune disease: a pilot study of safety and efficacy.

    Science.gov (United States)

    Garber, G E; Cameron, D W; Hawley-Foss, N; Greenway, D; Shannon, M E

    1991-08-01

    The use of ozone therapy is reported to be effective in a variety of viral illnesses, including HIV disease. We performed a phase I study of ozone blood treatments in 10 patients in whom no significant toxicity was observed. Three patients with moderate immunodeficiency showed improvement in surrogate markers of HIV-associated immune disease. A phase II controlled and randomized double-blinded study was initiated comparing reinjection of ozone-treated blood, and reinjection of unprocessed blood for 8 weeks, followed by a 4-week observation period. Ozone had no significant effect on hematologic, biochemical or clinical toxicity when compared with placebo. CD4 cell count, interleukin-2, gamma-interferon, beta 2-microglobulin, neopterin and p24 antigen were also unaffected by both treatment arms. In conclusion, ozone therapy does not enhance parameters of immune activation nor does it diminish measureable p24 antigen in HIV-infected individuals.

  3. Infrared matrix-isolation and theoretical studies of the reactions of ferrocene with ozone.

    Science.gov (United States)

    Kugel, Roger W; Pinelo, Laura F; Ault, Bruce S

    2015-03-19

    The reactions between ferrocene (Cp2Fe) (2a) and ozone (O3) were studied using low-temperature matrix-isolation techniques coupled with theoretical density functional theory (DFT) calculations. Co-deposition of Ar/Cp2Fe and Ar/O3 gas mixtures onto a cryogenically cooled CsI window produced a dark-green charge-transfer complex, Cp2Fe-O3, that photodecomposed upon red (λ ≥ 600 nm) and infrared (λ ≥ 1000 nm) irradiation but was stable to green or blue irradiation. Products of photodecomposition were characterized by FT-IR, oxygen-18 labeling, and DFT calculations using the B3LYP functionals and the 6-311G++(d,2p) basis set. Likely, photochemical products included four structures having the molecular formula C10H10FeO, identified by DFT calculations based on their calculated infrared spectra and (18)O isotope shifts. Each of these calculated molecules had one intact and fully coordinated η(5)-C5H5 cyclopentadienyl (Cp) ring and (1) an η(5)-C5H5O cyclic ether (pyran ring) (2b), (2) an η(4)-C5H5O linear aldehyde (2c), (3) a bidentate cyclic aldehyde with a seven-membered ring including the iron atom (2d), or (4) an Fe-O bond and an η(2)-C5H5 (Cp) ring (2e). No conclusive evidence for a gas-phase thermal reaction between ferrocene and ozone was observed under the conditions of these experiments. However, strong evidence for a surface-catalyzed thermal reaction was observed in merged-jet experiments wherein the gases were premixed before deposition. Surface-catalyzed ferrocene-ozone reaction products included a thin film of Fe2O3 observed on the walls of the merged tube as well as cyclopentadiene (C5H6), cyclopentadienone (C5H4O), and further oxidation products observed in the matrix. Possible mechanisms for both the photochemical and the thermal reactions are discussed.

  4. A model study of the response of mesospheric ozone to short-term solar ultraviolet flux variations

    Science.gov (United States)

    Summers, M. E.; Bevilacqua, R. M.; Strobel, D. F.; Zhu, Xun; Deland, M. T.; Allen, M.; Keating, G. M.

    1990-01-01

    An investigation is conducted in order to determine the relative importance of several modeled processes in controlling the magnitude and phase of the mesospheric ozone response. A detailed one-dimensional modeling study of the mesospheric ozone response to solar UV flux variations is conducted to remove some of the deficiencies in previous studies. This study is also used to examine specifically the importance of solar zenith angle, self-consistent calculation of water vapor abundance, and temperature feedback with a nonlocal thermodynamic equilibrium radiation model. The photochemical model is described, and the assumptions made for the purpose of comparing model results with the observed ozone response obtained from a statistical analysis of Solar Mesosphere Explorer data (Keating et al., 1987) are discussed. The numerical results for the theoretical ozone response are presented. The results of selected time-dependent calculations are considered to illustrate the degree to which a relatively simple model of the mesosphere is able to capture the major characteristics of the observed response.

  5. Effects of ozone nano-bubble water on periodontopathic bacteria and oral cells - in vitro studies

    Science.gov (United States)

    Hayakumo, Sae; Arakawa, Shinichi; Takahashi, Masayoshi; Kondo, Keiko; Mano, Yoshihiro; Izumi, Yuichi

    2014-10-01

    The aims of the present study were to evaluate the bactericidal activity of a new antiseptic agent, ozone nano-bubble water (NBW3), against periodontopathogenic bacteria and to assess the cytotoxicity of NBW3 against human oral cells. The bactericidal activities of NBW3 against representative periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) were evaluated using in vitro time-kill assays. The cytotoxicity of NBW3 was evaluated using three-dimensional human buccal and gingival tissue models. The numbers of colony forming units (CFUs)/mL of P. gingivalis and A. actinomycetemcomitans exposed to NBW3 dropped to below the lower limit of detection (therapy would be promising.

  6. Study of Oxidizing Agents for Tritium Removal in ITER -Compatible Conditions: Alternatives to Oxygen and Ozone

    Energy Technology Data Exchange (ETDEWEB)

    Tabares, F. L.; Tafalla, D.; Ferreira, J. A.; Gomez-Aleixandre, C.; Maria Albella, J.; Soria, J.; Rodriguez-Ramos, I.

    2007-07-20

    In the present report, the studies of tritiated carbon-film removal by oxidizing agents other than Oxygen and Ozone in ITER are described. Exposure of laboratory produced a-C:H/D films and tokamak flakes (Asdex Upgrade and Textor) to nitric oxide, water and hydrogen peroxide has been carried out. Temperatures of exposure up to 350 degree centigree were used, and thermal desorption of the samples at temperatures up to 750 degree centigree was performed for sample characterization prior to and after the treatment. Elastic Recoil Detection Analysis (ERDA), Infrared Spectroscopy, XPS and Nano indentation hardness analysis were applied to the characterization of the physical and chemical changes of the samples. This work was done under the EFDA Task 04-1175. (Author) 8 refs.

  7. La bella durmiente: el norte de Veracruz

    Directory of Open Access Journals (Sweden)

    Anath Ariel de Vidas

    2005-02-01

    Full Text Available La región del norte del Estado de Veracruz se ve en el mapa como una enorme extensión de un territorio llano de aproximadamente seis mil kilómetros cuadrados, poco poblado y careciendo totalmente de carreteras que lo atraviesan de la costa hacia el interior. Ocupa el espacio que va desde el río Pánuco y la frontera con Tamaulipas al norte, hasta la laguna de Tamiahua y la Sierra de Otontepec al sur y al poniente llega hasta los lomeríos de la Sierra Madre Oriental (ver mapa. Estas planicies ...

  8. Extreme waves from Nortes and climate change in the Gulf of Mexico

    Science.gov (United States)

    Appendini, Christian M.; Hernández-Lasheras, Jaime; Pedrozo-Acuña, Adrian; Meza-Padilla, Rafael

    2017-04-01

    Extreme ocean waves in the Gulf of Mexico are a result from the incidence of tropical cyclones and anticyclone systems known as Nortes. While the waves derived from tropical cyclones have devastating consequences but a low probability of occurrence, Nortes are a frequent phenomenon producing disruptions of maritime activities during autumn/winter months. In this study we present an assessment of the waves generated by Nortes and the effects of a warming climate. To do so, we first developed a methodology to identify Norte events and classify them according to their effect over the sea state. A new index is proposed to identify events, which was used to identify events in the present and future climates. A third generation wave model was run for each of the events identified in the CFSR reanalysis and the CMIP5 model CNRM-M5 under the RCP 8.5 scenario. Nortes were classified into 5 types, using both principal component analysis and a cluster analysis by k-means over the computed wave power of the individual events. An assessment of the effect of climate change was performed over the different Norte types, which indicated that climate change will result in less frequent events of higher intensity and more frequent mild events. This may provide a relief for coastal and marine operations, in relation to downtimes due to extreme wave conditions, so that the operational design of maritime structures could consider a lower occurrence of extreme events as a result of Nortes. While the results are not conclusive due to the uncertainty imposed by Global Circulation Models, this study provides the methodology to perform the assessment on other models to reduce uncertainty.

  9. The effect of rectal ozone on the portal vein oxygenation and pharmacokinetics of propranolol in liver cirrhosis (a preliminary human study).

    Science.gov (United States)

    Zaky, Saad; Fouad, Ehab Ahmad; Kotb, Hassan Ibrahim Mohamad

    2011-03-01

    The aim of this study was to investigate the effect of rectal ozone on portal vein oxygenation and the pharmacokinetic changes of propranolol in patients with liver cirrhosis. Fifteen patients with liver cirrhosis were included They were given a fixed oral dose of propranolol 80mg on the morning of day 1 after overnight fasting. Blood samples were collected at fixed time intervals for 24h. Patients were given 12 sessions of rectal ozone of 300ml of 40% ozone/oxygen mixture. On day 14 another oral dose of 80mg propranolol was given and blood samples were collected as on day 1. Plasma concentrations of propranolol were measured by HPLC. Portal vein oxygen tension and saturation were measured before and after rectal ozone. Plasma concentrations of propranolol were reduced after ozone therapy with pronounced decreases in the maximum plasma concentration and the area under the plasma concentration-time curve. The changes were consistent with a decrease in propranolol bioavailability. There was a decrease in the elimination half-life and mean residence time. Portal vein oxygenation significantly increased after rectal ozone. The changes in the pharmacokinetics of propranolol probably reflect an increase in the rate and extent of its metabolism resulting from improved portal vein oxygenation attributable to the ozone therapy. The present work highlights that ozone can be an alternative medical measure to improve portal vein oxygenation in liver cirrhosis. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

  10. Mid-latitude ozone changes: studies with a 3-D CTM forced by ERA-40 analyses

    Directory of Open Access Journals (Sweden)

    W. Feng

    2007-01-01

    Full Text Available We have used an off-line three-dimensional (3-D chemical transport model (CTM to study long-term changes in stratospheric O3. The model was run from 1977–2004 and forced by ECMWF ERA-40 and operational analyses. Model runs were performed to examine the impact of increasing halogens and additional stratospheric bromine from short-lived source gases. The analyses capture much of the observed interannual variability in column ozone, but there are also unrealistic features. In particular the ERA-40 analyses cause a large positive anomaly in northern hemisphere (NH column O3 in the late 1980s. Also, the change from ERA-40 to operational winds at the start of 2002 introduces abrupt changes in some model fields (e.g. temperature, ozone which affect analysis of trends. The model reproduces the observed column increase in NH mid-latitudes from the mid 1990s. Analysis of a run with fixed halogens shows that this increase is not due to a significant decrease in halogen-induced loss, i.e. is not an indication of recovery. The model predicts only a small decrease in halogen-induced loss after 1999. In the upper stratosphere, despite the modelled turnover of chlorine around 1999, O3 does not increase because of the effects of increasing ECMWF temperatures, decreasing modelled CH4 at this altitude, and abrupt changes in the SH temperatures at the end of the ERA-40 period. The impact of an additional 5 pptv stratospheric bromine from short-lived species decreases mid-latitude column O3 by about 10 DU. However, the impact on the modelled relative O3 anomaly is generally small except during periods of large volcanic loading.

  11. Aquolab ® ozone-therapy is an efficient adjuvant in the treatment of chronic periodontitis: A case-control study

    Directory of Open Access Journals (Sweden)

    Francesco Carinci

    2015-01-01

    Full Text Available Aim: The objective of this study was to compare the efficacy of supportive periodontal therapy (i.e., scaling and root planning [SRP] alone versus Aquolab ® ozone therapy used in association with SRP in the treatment of chronic periodontitis in adult patients. Materials and Methods: A total of 20 patients with a diagnosis of chronic periodontitis (40 localized chronic periodontitis sites were enrolled. None of these patients have previously received any surgical or nonsurgical periodontal therapy and demonstrated radiographic evidence of moderate bone loss. Two nonadjacent sites in separate quadrants were selected in each patient to verify treatment efficacy (split-mouth design. Microbial analysis was analyzed at baseline and the 7 th day after treatment. SPSS program and paired simple statistic t-test were used to detect statistically significant differences. Results: There was a statistically significant reduction of Tannerella forsythia loading in sites treated with ozone therapy respect to those treated with SPR alone. A similar trend was obtained also for additional 5 species and for total bacterial loading (CBT. These results were obtained with a single local application of ozone therapy just after SPR and with a molecular control 7 th day after treatment. Conclusion : Aquolab ® ozone therapy in is effective in reducing the CBT in pockets of patients affected by periodontitis. It is an efficacy medical device to be used as adjuvant therapy to be added to SRP in the management of moderate to severe chronic periodontitis.

  12. Investigation of Ozone Yield of Air Fed Ozonizer by High Pressure Homogeneous Dielectric Barrier Discharge

    Science.gov (United States)

    2013-07-01

    field strength in the discharge. In order to clarify this phenomenon, further study on the gas analysis within the ozone gas by an FTIR spectrometer...31st ICPIG, July 14-19, 2013, Granada, Spain Investigation of ozone yield of air fed ozonizer by high pressure homogeneous dielectric barrier... ozonizer and found that the ozone yield is higher by the homogeneous discharge mode than by the conventional filamentary discharge mode in larger

  13. Ozone decomposition

    Directory of Open Access Journals (Sweden)

    Batakliev Todor

    2014-06-01

    Full Text Available Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers. Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates

  14. [Experiment study on the aqueous removal of SO2 by Mn2+ catalytic ozonation].

    Science.gov (United States)

    Ma, Shuang-Chen; Su, Min; Ma, Jing-Xiang; Sun, Yun-Xue; Jin, Xin; Zhao, Yi

    2009-11-01

    The removal of SO2 by Mn2+ catalytic aqueous ozonation was investigated by experiment, so as to find the effects of Mn2+ for aqueous removal of SO2 by ozonation. The concentration curve of ozone was drawn by standard iodine method. The operating factors included mole ratio of ozone to sulfur dioxide and concentration of Mn2+. When absorption solution has no Mn2+, the removal efficiency of SO2 was 35% at [O3 ]/[SO2 ] = 0.5,but the efficiency was 70% when Mn2+ was put into absorption solution at the same value of [O3 ]/[SO2].With the increasing of [3O]/[SO2], the removal efficiency of SO2 increases. And as concentration of Mn2+ increases, the efficiency also increases. There is an appropriate concentration range which is 1.2 x 10(-2)-1.2 x 10(-1) mol/L for Mn2+.

  15. A case study to determine the efficacy of ozonation in purification ...

    African Journals Online (AJOL)

    2010-06-28

    Jun 28, 2010 ... 10 = Storage and distribution. 11 = Office (not shown .... sodium, sulphate, faecal coliform bacteria, magnesium, aluminium, ammonia ..... depression, ammonia addition, ozone dose and hydrogen peroxide addition (Westerhoff ...

  16. Modeling nitrous acid and its impact on ozone and hydroxyl radical during the Texas Air Quality Study 2006

    Directory of Open Access Journals (Sweden)

    B. H. Czader

    2012-08-01

    Full Text Available Nitrous acid (HONO mixing ratios for the Houston metropolitan area were simulated with the Community Multiscale Air Quality (CMAQ Model for an episode during the Texas Air Quality Study (TexAQS II in August/September 2006 and compared to in-situ MC/IC (mist-chamber/ion chromatograph and long path DOAS (Differential Optical Absorption Spectroscopy measurements at three different altitude ranges. Several HONO sources were accounted for in simulations, such as gas phase formation, direct emissions, nitrogen dioxide (NO2 hydrolysis, photo-induced formation from excited NO2 and photo-induced conversion of NO2 into HONO on surfaces covered with organic materials. Compared to the gas-phase HONO formation there was about a tenfold increase in HONO mixing ratios when additional HONO sources were taken into account, which improved the correlation between modeled and measured values. Concentrations of HONO simulated with only gas phase chemistry did not change with altitude, while measured HONO concentrations decrease with height. A trend of decreasing HONO concentration with altitude was well captured with CMAQ predicted concentrations when heterogeneous chemistry and photolytic sources of HONO were taken into account. Heterogeneous HONO production mainly accelerated morning ozone formation, albeit slightly. Also HONO formation from excited NO2 only slightly affected HONO and ozone (O3 concentrations. Photo-induced conversion of NO2 into HONO on surfaces covered with organic materials turned out to be a strong source of daytime HONO. Since HONO immediately photo-dissociates during daytime its ambient mixing ratios were only marginally altered (up to 0.5 ppbv, but significant increase in the hydroxyl radical (OH and ozone concentration was obtained. In contrast to heterogeneous HONO formation that mainly accelerated morning ozone formation, inclusion of photo-induced surface chemistry

  17. Modeling nitrous acid and its impact on ozone and hydroxyl radical during the Texas Air Quality Study 2006

    Directory of Open Access Journals (Sweden)

    B. H. Czader

    2012-02-01

    Full Text Available Nitrous acid (HONO mixing ratios for the Houston metropolitan area were simulated with the Community Multiscale Air Quality (CMAQ model for an episode during the Texas Air Quality Study (TexAQS II in August/September 2006 and compared to in-situ MC/IC (mist-chamber/ion chromatograph and long path DOAS (Differential Optical Absorption Spectroscopy measurements at three different altitudes. Several HONO sources were accounted for in simulations, such as gas phase formation, direct emissions, nitrogen dioxide (NO2* hydrolysis, photo-induced formation from excited NO2* and photo-induced conversion of NO2 into HONO on surfaces covered with organic materials. Compared to the gas-phase HONO formation there was about a tenfold increase in HONO mixing ratios when additional HONO sources were taken into account, which improved the correlation between modeled and measured values. Concentrations of HONO simulated with only gas phase chemistry did not change with altitude, while measured HONO concentrations decrease with height. A trend of decreasing HONO concentration with altitude was well captured with CMAQ predicted concentrations when heterogeneous chemistry and photolytic sources of HONO were taken into account. Heterogeneous HONO production mainly accelerated morning ozone formation, albeit slightly. Also HONO formation from excited NO2 only slightly affected HONO and ozone (O3 concentrations. Photo-induced conversion of NO2 into HONO on surfaces covered with organic materials turned out to be a strong source of daytime HONO. Since HONO immediately photo-dissociates during daytime its ambient mixing ratios were only marginally altered (up to 0.5 ppbv, but significant increase in the hydroxyl radical (OH and ozone concentration was obtained. In contrast to heterogeneous HONO formation that mainly accelerated morning ozone formation, inclusion of photo

  18. Study on an integrated process combining ozonation with ceramic ultra-filtration for decentralized supply of drinking water.

    Science.gov (United States)

    Zhu, Jia; Fan, Xiao J; Tao, Yi; Wei, De Q; Zhang, Xi H

    2014-09-19

    An integrated process was specifically developed for the decentralized supply of drinking water from micro-polluted surface water in the rural areas of China. The treatment process combined ozonation with ceramic ultra-filtration (UF), coagulation for pre-treatment and granular activated carbon filtration. A flat-sheet ceramic membrane was used with a cut-off of 60 nm and the measurement of 254 mm (length) × 240 mm (width) × 6 mm (thickness). Ozonation and ceramic UF was set up whthin one reactor. The experimental results showed that the removal efficiencies of the dissolved organic carbon (DOC) and the formation potential of trihalomethanes (THMs), haloacetic acids (HAAs) and ammonia were 80%, 76%, 70% and 90%, respectively; that the turbidity of the product water was below 0.2 NTU and the particle count number (particles larger than 2 μm) was less than 50 counts per mL. The result also showed that all the pathogenic microorganisms were retained by the ceramic and that UF. Ozonation played a critical role in the control of membrane fouling and the removal of contaminants. Exactly, the membrane fouling can be controlled in situ with 3 mg L(-1) ozone at the permeate flux of 80 L m(-2) h(-1), yet the required dosage of ozone was dependent on the quality of the raw water. Therefore, this study is able to provide a highly compacted system for decentralized supply of high-quality drinking water in terms of both chemical and microbiological safety for the rural areas in China.

  19. The contribution of anthropogenic bromine emissions to past stratospheric ozone trends: a modelling study

    Directory of Open Access Journals (Sweden)

    B.-M. Sinnhuber

    2009-04-01

    Full Text Available Bromine compounds play an important role in the depletion of stratospheric ozone. We have calculated the changes in stratospheric ozone in response to changes in the halogen loading over the past decades, using a two-dimensional (latitude/height model constrained by source gas mixing ratios at the surface. Model calculations of the decrease of total column ozone since 1980 agree reasonably well with observed ozone trends, in particular when the contribution from very short-lived bromine compounds is included. Model calculations with bromine source gas mixing ratios fixed at 1959 levels, corresponding approximately to a situation with no anthropogenic bromine emissions, show an ozone column reduction between 1980 and 2005 at Northern Hemisphere mid-latitudes of only ≈55% compared to a model run including all halogen source gases. In this sense anthropogenic bromine emissions are responsible for ≈45% of the model estimated column ozone loss at Northern Hemisphere mid-latitudes. However, since a large fraction of the bromine induced ozone loss is due to the combined BrO/ClO catalytic cycle, the effect of bromine would have been smaller in the absence of anthropogenic chlorine emissions. The chemical efficiency of bromine relative to chlorine for global total ozone depletion from our model calculations, expressed by the so called α-factor, is 64 on an annual average. This value is much higher than previously published results. Updates in reaction rate constants can explain only part of the differences in α. The inclusion of bromine from very short-lived source gases has only a minor effect on the global mean α-factor.

  20. Long-term exposure to ambient ozone and mortality: a quantitative systematic review and meta-analysis of evidence from cohort studies.

    Science.gov (United States)

    Atkinson, R W; Butland, B K; Dimitroulopoulou, C; Heal, M R; Stedman, J R; Carslaw, N; Jarvis, D; Heaviside, C; Vardoulakis, S; Walton, H; Anderson, H R

    2016-02-23

    While there is good evidence for associations between short-term exposure to ozone and a range of adverse health outcomes, the evidence from narrative reviews for long-term exposure is suggestive of associations with respiratory mortality only. We conducted a systematic, quantitative evaluation of the evidence from cohort studies, reporting associations between long-term exposure to ozone and mortality. Cohort studies published in peer-reviewed journals indexed in EMBASE and MEDLINE to September 2015 and PubMed to October 2015 and cited in reviews/key publications were identified via search strings using terms relating to study design, pollutant and health outcome. Study details and estimate information were extracted and used to calculate standardised effect estimates expressed as HRs per 10 ppb increment in long-term ozone concentrations. 14 publications from 8 cohorts presented results for ozone and all-cause and cause-specific mortality. We found no evidence of associations between long-term annual O3 concentrations and the risk of death from all causes, cardiovascular or respiratory diseases, or lung cancer. 4 cohorts assessed ozone concentrations measured during the warm season. Summary HRs for cardiovascular and respiratory causes of death derived from 3 cohorts were 1.01 (95% CI 1.00 to 1.02) and 1.03 (95% CI 1.01 to 1.05) per 10 ppb, respectively. Our quantitative review revealed a paucity of independent studies regarding the associations between long-term exposure to ozone and mortality. The potential impact of climate change and increasing anthropogenic emissions of ozone precursors on ozone levels worldwide suggests further studies of the long-term effects of exposure to high ozone levels are warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  1. Surface ozone variation at Bhubaneswar and intra-corelationship study with various parameters

    Indian Academy of Sciences (India)

    P S Mahapatra; J Jena; S Moharana; H Srichandan; T Das; G Roy Chaudhury; S N Das

    2012-10-01

    This paper summarizes the results of year long (December 2009 to January 2011) continuous measurements of daytime (0700–1745) ozone (O3) in the ambient air and related meteorological parameters at Bhubaneswar (21° 15′N–85° 15′E), Odisha. The seasonal variation shows distinct daytime ozone maxima during winters with a peak in January (∼85 ppbv), a slight increase (∼38 ppbv) in June and lowest in August (∼20 ppbv). The backward trajectory analysis during winter months suggests long distance transport of airmass from mainly Indo-Gangetic Plains (IGP) and western part of Indian peninsula, a major industrial hub. In other seasons, wind reaches the observation site from less polluted landmasses and the Bay of Bengal, thereby considerably reducing the pollution load. On the contrary, ozone build-up was found to be maximum and minimum in pre-monsoon and monsoon, respectively. An anti-weekend ozone effect (∼5 ppbv) was observed in winter. Paired t-test and F-test along with principal component analysis (PCA) were done to determine significance between various components (ozone, precursors and meteorological parameters). The t- and F-test showed significant monthly variation of ozone mixing ratio. The PCA showed that three components explained 79.1% of variances.

  2. Numerical study on the ozone formation inside street canyons using a chemistry box model

    Institute of Scientific and Technical Information of China (English)

    Chun-Ho Liu; Dennis Y. C. Leung

    2008-01-01

    Tropospheric ozone is a secondary air pollutant produced in the presence of nitrogen oxides, volatile organic compounds (VOCs), and solar radiation. In an urban environment, ground-level vehicular exhaust is the major anthropogenic source of ozone precursors. In the cases of street canyons, pollutant dilution is weakened by the surrounding buildings that create localized high concentration of nitrogen oxides and VOCs, and thus leads to high potential of ozone formation. By considering the major physical and chemical processes, a chemistry box model is employed to investigate the characteristics of ozone formation due to vehicular exhaust inside street canyons under the worst case scenario, i.e. the calm wind condition. It is found that a high level of ozone concentration, of the order of 100 ppbv and higher, would occur inside the street canyons, in particular, when the emission rate (concentration) ratio of VOCs to nitrogen oxides is greater than 10. This elevated ozone concentration appears at the transition from VOCs to nitrogen oxides sensitivity and may extend to a few hundreds.

  3. Saúde infantil em áreas pobres: resultados de um estudo de base populacional nos municípios de Caracol, Piauí, e Garrafão do Norte, Pará, Brasil Child health in poor areas: findings from a population-based study in Caracol, Piauí, and Garrafão do Norte, Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Juraci A. Cesar

    2009-04-01

    Full Text Available Este estudo teve por objetivo conhecer indicadores básicos de saúde infantil nos municípios de Caracol, Piauí, e Garrafão do Norte, Pará, Brasil. Mediante visitas domiciliares por amostragem sistemática, aplicaram-se questionários às mães de menores de cinco anos, investigando nível sócio-econômico, condições de habitação e saneamento da família, características demográficas, padrão de morbidade, de utilização de serviços de saúde e de assistência recebida durante a gestação e o parto. A análise consistiu da comparação de indicadores entre os dois municípios e foi avaliada através dos testes t e qui-quadrado. Das 1.728 crianças estudadas, 60% de suas famílias possuíam renda inferior a um salário mínimo mensal; 41% não contavam com qualquer tipo de sanitário; 10% de suas mães não realizaram uma única consulta de pré-natal; 30% nasceram no domicilio; 30% foram levadas à consulta médica nos últimos três meses; 20% apresentavam déficit > 2 desvios-padrão para o indicador altura/idade. Todos os indicadores estudados foram ruins em ambos os municípios, sobretudo em Garrafão do Norte. Aumentar a oferta de cuidados em saúde e melhorar as condições de habitação e saneamento deveriam ser prioridades nessas localidades.The aim of this study was to evaluate child health indicators in the municipalities (counties of Caracol, Piauí State, and Garrafão do Norte, Pará State, Brazil. Through household visits using systematic sampling, previously trained interviewers applied a standard questionnaire to mothers of under-five children, investigating socioeconomic status, housing and environmental sanitation, demographic characteristics, disease patterns, and prenatal and childbirth care. The analysis used the t-test and chi-square test to compare indicators between the two municipalities. Of the 1,728 children studied, 60% were from families with incomes less than one monthly minimum wage (approximately U

  4. Solar response in tropical stratospheric ozone: a 3-D chemical transport model study using ERA reanalyses

    Directory of Open Access Journals (Sweden)

    S. Dhomse

    2011-12-01

    Full Text Available We have used an off-line 3-D chemical transport model (CTM to investigate the 11-yr solar cycle response in tropical stratospheric ozone. The model is forced with European Centre for Medium-Range Weather Forecasts (ECMWF (reanalysis (ERA-40/operational and ERA-Interim data for the 1979–2005 time period. We have compared the modelled solar response in ozone to observation-based data sets that are constructed using satellite instruments such as Total Ozone Mapping Spectrometer (TOMS, Solar Backscatter UltraViolet instrument (SBUV, Stratospheric Aerosol and Gas Experiment (SAGE and Halogen Occultation Experiment (HALOE. A significant difference is seen between simulated and observed ozone during the 1980s, which is probably due to inhomogeneities in the ERA-40 reanalyses. In general, the model with ERA-Interim dynamics shows better agreement with the observations from 1990 onwards than with ERA-40. Overall both standard model simulations are partially able to simulate a "double peak"-structured ozone solar response with a minimum around 30 km, and these are in better agreement with HALOE than SAGE-corrected SBUV (SBUV/SAGE or SAGE-based data sets. In the tropical lower stratosphere (TLS, the modelled solar response with time-varying aerosols is amplified through aliasing with a volcanic signal, as the model overestimates ozone loss during high aerosol loading years. However, the modelled solar response with fixed dynamics and constant aerosols shows a positive signal which is in better agreement with SBUV/SAGE and SAGE-based data sets in the TLS. Our model simulations suggests that photochemistry contributes to the ozone solar response in this region. The largest model-observation differences occur in the upper stratosphere where SBUV/SAGE and SAGE-based data show a significant (up to 4% solar response whereas the standard model and HALOE do not. This is partly due to a positive solar response in the ECMWF upper stratospheric temperatures which

  5. A Geostatistical Approach to Reducing Uncertainty in Rainfall Estimates Using Terrain Characteristics: A Case Study in the Central-North Regional Water Administration of Mozambique (ARA Centro-Norte)

    Science.gov (United States)

    Raheem, Y. T.; Freyberg, D. L.

    2012-12-01

    Many data-sparse regions, such as southern Africa, will likely face significant changes in water resources availability and timing in the future due land use change, climate change and population growth. Improved estimates of rainfall and streamflow are necessary to improve water resources decision-making, risk management, and uncertainty quantification. In this study, we use a universal kriging framework to associate various watershed terrain characteristics with gauged rainfall data to improve the estimation of monthly rainfall fields. We focus on available gauge data because other precipitation data sources, such as satellite precipitation products, are unavailable over historic periods of interest and exhibit bias in our context of streamflow estimation. Our study area is the 185,000 sq km Central-North Regional Water Administration of Mozambique (ARA Centro-Norte), which is predominantly rural tropical savanna. We use fifty years of spatially and temporally sparse monthly rainfall observations from 316 rainfall gauges. Most of the watershed terrain characteristics we use are derived from the 90m HydroSHEDS Digital Elevation Model dataset. These include elevation, aspect, slope, distance to large water bodies, distance to ridges, and distance to watershed rainfall maximum. We quantify the importance of these characteristics for reducing uncertainty in rainfall estimates using the Bayes information criterion (BIC) approach. Future work includes using these rainfall estimates to drive the semi-distributed monthly time-step Pitman rainfall-runoff model, in order to reduce uncertainty in streamflow estimates in gauged and ungauged basins.

  6. 环境空气中臭氧API评价探讨%Study on Air Ozone API Evaluation

    Institute of Scientific and Technical Information of China (English)

    徐建平

    2012-01-01

    Air ozone API evaluation is considered that area of influence on ozone concentration exceed ambient air quality, ozone API correction on hours on ozone concentration exceed ambient air quality and Ozone average concentration exceed ambient air quality.%环境空气中臭氧API评价应考虑臭氧超标影响范围、臭氧超标小时数和超标平均浓度对臭氧API修正.

  7. Infrared spectroscopic studies of the heterogeneous reaction of ozone with dry maleic and fumaric acid aerosol particles.

    Science.gov (United States)

    Nájera, Juan J; Percival, Carl J; Horn, Andrew B

    2009-10-28

    Dicarboxylic acids, either directly emitted or formed in chemical processes, are found to be a significant component of tropospheric aerosols. To assess any potential chemical transformation of short unsaturated dicarboxylic acids in tropospheric heterogeneous chemistry, maleic and fumaric acid were selected as surrogates in this study. A novel aerosol flow tube apparatus is employed to perform kinetic studies of the oxidation of these organic compounds by gas-phase ozone. The system consists of a particle generation system, a vertically oriented glass flow tube and an infrared observation White cell with a Fourier transform infrared (FTIR) spectrometer for the detection system. A flow of single component organic aerosols with mean diameters ranging between 0.7 and 1.1 microm is introduced in a flow tube, in which the particles are subsequently exposed to a known concentration of ozone for a controlled period of time. A band assignment of infrared vibrational frequencies for dry maleic and fumaric acid aerosol spectra is presented. These studies are complemented with off-line analysis on the reaction products. The reaction exhibited pseudo-first-order kinetics on gas product formation, and the pseudo-first-order rate coefficients displayed a Langmuir-Hinshelwood dependence on gas-phase ozone concentration for both materials. By assuming a Langmuir-Hinshelwood behaviour, the following parameters were obtained: for the reaction of maleic acid aerosols, K(O3) = (3.3 + 0.5) x 10(-16) cm3 molecule(-1) and k(I)(max) = (0.038 + 0.004) s(-1); for the reaction of fumaric acid aerosols, K(O3) = (1.6 + 0.5) x 10(-16) cm3 molecule(-1) and k(I)(max) = (0.048 + 0.007) s(-1), where K(O3) is a parameter that describes the partitioning of ozone to the particle surface and k is the maximum pseudo-first-order coefficient at high ozone concentrations. Apparent reactive uptake coefficients were estimated from the pseudo-first-order rate coefficient and a trend of decreasing uptake

  8. Ozone response to emission changes: a modeling study during the MCMA-2006/MILAGRO Campaign

    Directory of Open Access Journals (Sweden)

    J. Song

    2010-04-01

    Full Text Available The sensitivity of ozone production to precursor emissions was investigated under five different meteorological conditions in the Mexico City Metropolitan Area (MCMA during the MCMA-2006/MILAGRO field campaign using the gridded photochemical model CAMx driven by observation-nudged WRF meteorology. Precursor emissions were constrained by the comprehensive data from the field campaign and the routine ambient air quality monitoring network. Simulated plume mixing and transport were examined by comparing with measurements from the G-1 aircraft during the campaign. The observed concentrations of ozone precursors and ozone were reasonably well reproduced by the model. The effects of reducing precursor emissions on urban ozone production were performed for three representative emission control scenarios. A 50% reduction in VOC emissions led to 7 to 22 ppb decrease in daily maximum ozone concentrations, while a 50% reduction in NOx emissions leads to 4 to 21 ppb increase, and 50% reductions in both NOx and VOC emission decrease the daily maximum ozone concentrations up to 10 ppb. These results along with a chemical indicator analysis using the chemical production ratios of H2O2 to HNO3 demonstrate that the MCMA urban core region is VOC-limited for all meteorological episodes, which is consistent with the results from MCMA-2003 field campaign; however the degree of the VOC-sensitivity is higher during MCMA-2006 due to lower VOCs, lower VOC reactivity and moderately higher NOx emissions. Ozone formation in the surrounding mountain/rural area is mostly NOx-limited, but can be VOC-limited, and the range of the NOx-limited or VOC-limited areas depends on meteorology.

  9. Ozone response to emission changes: a modeling study during the MCMA-2006/MILAGRO campaign

    Directory of Open Access Journals (Sweden)

    R. Zhang

    2009-11-01

    Full Text Available The sensitivity of ozone production to precursor emissions was investigated under five different meteorological conditions in the Mexico City Metropolitan Area (MCMA during the MCMA-2006/MILAGRO field campaign using the gridded photochemical model CAMx driven by observation-nudged WRF meteorology. Precursor emissions were constrained by the comprehensive data from the field campaign and the routine ambient air quality monitoring network. Simulated plume mixing and transport were examined by comparing with measurements from the G-1 aircraft during the campaign. The observed concentrations of ozone precursors and ozone were well reproduced by the model. The effects of reducing precursor emissions on urban ozone production were performed for three representative emission control strategies. A 50% reduction in VOC emissions led to 7 to 22 ppb decrease in daily maximum ozone concentrations, while a 50% reduction in NOx emissions leads to 4 to 21 ppb increase, and 50% reductions in both NOx and VOC emission decrease the daily maximum ozone concentrations up to 10 ppb. These results along with a chemical indicator analysis using the chemical production ratios of H2O2 to HNO3 demonstrate that the MCMA urban core region is VOC-limited for all meteorological episodes, which is consistent with the results from MCMA-2003 field campaign; however the degree of the VOC-sensitivity is higher in the MCMA-2006 due to lower VOC/NOx emission ratio and VOC reactivity. Ozone formation in the surrounding mountain/rural area is mostly NOx-limited, but can be VOC-limited, and the range of the NOx-limited or VOC-limited areas depends on meteorology.

  10. 臭氧冰在水产品保鲜中的研究%The Study on Ozone Ice in the Freshness Keeping of Fishery Products

    Institute of Scientific and Technical Information of China (English)

    徐涛

    2009-01-01

    The effects of ozone ice on the shelf life of Pseudosciaena crocea and cuttlefish, stored under refrigeration (4±0.5℃) were studied by monitoring the microbiological, chemical and sensory changes for a period of 17 days. Results showed that the shelf life could be lengthened 4~5 days preserved by 4mg/kg ozone ice. The total volatility basis nitrogen (TVB-N) was reduced and the bacteria colony was decreased by 92%. The bactericidal effectiveness of ozone ice is strong enough to attain better preservation effect. As a convenient, simple and environmental friendly method, it could be used in the preservation and transportation of fishery products.

  11. A cross-sectional study to estimate the frequency of anti-bovine viral diarrhea virus-1 antibodies in domestic pigs of Mossoró region in the state of Rio Grande do Norte, Brazil

    Directory of Open Access Journals (Sweden)

    Igor Renan Honorato Gatto

    2016-01-01

    Full Text Available ABSTRACT: This study investigated the occurrence of antibodies for BVDV-1 in swine herds located in the region of Mossoró city of the state of Rio Grande do Norte, Brazil. A sample size of 412 animals was estimated assuming unknown prevalence (set at 50%. Virus neutralization assay was used to the detect the presence of antibodies for BVDV-1 and the results found were analysed using multivariable logistic regression model. The obtained prevalence was 4% at animal level and 45% at the animal and herd level. The titers were highly variable between animals and within farms. The multivariable logistic regression analysis showed an association between being housed outside and exposure to BVDV-1 (OR=0.24, 95% CI:0.06, 0.96, P=0.04. Highly correlated data and low prevalence of antibodies at the animal level resulted in insufficient power to detect significant differences with other selected risk factors. In conclusion, the prevalence is within the range reported for other countries.

  12. Numerical Study of the Simultaneous Oxidation of NO and SO2 by Ozone

    Directory of Open Access Journals (Sweden)

    Bo Li

    2015-01-01

    Full Text Available This study used two kinetic mechanisms to evaluate the oxidation processes of NO and SO2 by ozone. The performance of the two models was assessed by comparisons with experimental results from previous studies. The first kinetic mechanism was a combined model developed by the author that consisted of 50 species and 172 reactions. The second mechanism consisted of 23 species and 63 reactions. Simulation results of both of the two models show under predictions compared with experimental data. The results showed that the optimized reaction temperature for NO with O3 ranged from 100~200 °C. At higher temperatures, O3 decomposed to O2 and O, which resulted in a decrease of the NO conversion rate. When the mole ratio of O3/NO was greater than 1, products with a higher oxidation state (such as NO3, N2O5 were formed. The reactions between O3 and SO2 were weak; as such, it was difficult for O3 to oxidize SO2.

  13. Three air quality studies: Great Lakes ozone formation and nitrogen dry deposition; and Tucson aerosol chemical characterization

    Science.gov (United States)

    Foley, Theresa

    The Clean Air Act of 1970 was promulgated after thousands of lives were lost in four catastrophic air pollution events. It authorized the establishment of National Ambient Air Quality Standards or (NAAQS) for six pollutants that are harmful to human health and welfare: carbon monoxide, lead, nitrogen dioxide, particulate matter, ozone and sulfur dioxide. The Clean Air Act also led to the establishment of the United Stated Environmental Protection Agency (US EPA) to set and enforce regulations. The first paper in this dissertation studies ozone in the Lake Michigan region (Foley, T., Betterton, E.A., Jacko, R., Hillery, J., 2011. Lake Michigan air quality: The 1994-2003 LADCO Aircraft Project (LAP). Atmospheric Environment 45, 3192-3202.) The Chicago-Milwaukee-Gary metropolitan area has been unable to meet the ozone NAAQS since the Clean Air Act was implemented. The Lake Michigan Air Directors' Consortium (LADCO) hypothesized that land breezes transport ozone precursor compounds over the lake, where a large air/water temperature difference creates a shallow conduction layer, which is an efficient reaction chamber for ozone formation. In the afternoon, lake breezes and prevailing synoptic winds then transport ozone back over the land. To further evaluate this hypothesis, LADCO sponsored the 1994-2003 LADCO Aircraft Project (LAP) to measure the air quality over Lake Michigan and the surrounding areas. This study has found that the LAP data supports this hypothesis of ozone formation, which has strong implications for ozone control strategies in the Lake Michigan region. The second paper is this dissertation (Foley, T., Betterton, E.A., Wolf, A.M.A., 2012. Ambient PM10 and metal concentrations measured in the Sunnyside Unified School District, Tucson, Arizona. Journal of the Arizona-Nevada Academy of Science, 43, 67-76) evaluated the airborne concentrations of PM10 (particulate matter with an aerodynamic diameter of 10 microns or less) and eight metalloids and metals

  14. [Preliminary study on suitability of ozone sterilization in traditional Chinese medicine and its preparation].

    Science.gov (United States)

    Hu, Yan-jun; Wang, Ya-qi; Wu, Zhen-feng; Lan, Ji-ping; Zhang, Li-guo; Yang, Ming

    2015-08-01

    Microbial contamination, growth and reproduction have a great influence on the quality of traditional Chinese medicine (TCM) and its preparation. TCM may be polluted by microbial in the production process due to ambient air, facilities and appliances and operating personnel, which affects the quality and efficacy of the final product. The GMP certification inspection standard of TCM manufacturing enterprises clearly established: "Sterilization methods of Chinese herbal medicine, intermediate products, finished products should follow the principle whether or not to change its quality", "TCM powder that used as medicine directly should follow the principle whether to do microbiological examinations". So it's particularly important for product quality, corporate energy consumption and its efficiency to choose the scientific and effective sterilization techniques and methods. Ozone is a kind of safe, environmentally friendly, efficient and no residue emerging sterilization technology. It has been widely applied in various fields of medical and health care and production and living. This paper mainly analyzed the ozone sterilization technology of TCM, aiming to explore the principle of ozone sterilization, the advantages, application status and existing problems and so on. The management regulations and implementation rules of ozone sterilization were summarized to make sterilization of Chinese medicine in the production, management, quality control and other aspects standardized, reasonable and scientific, and to provide the theoretical reference of the ozone sterilization technology for TCM and its preparation.

  15. Pilot study on bromate reduction in ozonation of water with low carbonate alkalinities by carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    Ji Li; Li Zou; Lulu Guo; Jialin Ji

    2011-01-01

    A pilot study was carried out to explore the application of carbon dioxide for pH depression in a bubble column and its ability to inhibit bromate formation for water with a low alkalinity.Results showed that in the absence of ammonia,CO2 was capable of reducing bromate 38.0%-65.4% with one-unit pH depression.CO2 caused a slightly lower bromate reduction (4.2%) than did H2SO4 when the pH was depressed to 7.4,and a more a pronounced lower reduction (8.8%) when the pH was depressed to 6.9.In the presence of 0.20mg/L-N ammonia,bromate was largely inhibited with 73.9% reduction.When the pH was depressed to 7.4,CO2 and H2SO4 showed an 11.3% and 23.5% bromate reduction respectively,demonstrating that the joint use of CO2 and ammonia might be a plausible strategy of blocking all three bromate formation pathways.CO2 could be applied through the aeration diffuser together with ozone gas,resulting in a similar bromate reduction compared with the premixing method through Venturi mixer.

  16. Mechanistic study of ozonation of p-nitrophenol in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    SHI Hui-xiang; XU Xian-wen; XU Xin-hua; WANG Da-hui; WANG Qi-da

    2005-01-01

    Ozonlysis in the treatment of p-nitrophenol solution was studied in this paper. The results indicated that the decomposition of pnitrophenol was accelerated as the gas flow rate or pH value increased. When gaseous ozone concentration was 20.11 mg/L and pH was 3, after 24 min reaction, the removal rate of p-nitrophenol reached 73.04%, 86. 11%, 91.71 % and 95 % at the gas flow rate of 32, 40, 48and 56 ml/min respectively. And when pH was 3, 4, 5, 6, the decomposition rate was 66.38%, 82.09%, 90.46%, 97.50% after a 20min reaction respectively. It was mainly O3 molecule that took part in the decomposition when pH was 3. The main intermediates during the decomposition include catechol, o-benzoquinone, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-nitrophenol was also discussed.

  17. Micro-organism re-growth in wastewater disinfected by UV radiation and ozone: a micro-biological study.

    Science.gov (United States)

    Alonso, E; Santos, A; Riesco, P

    2004-04-01

    A series of disinfection experiments using UV radiation and ozone was performed on the secondary effluent from a wastewater treatment plant at a pilot plant scale. The microbial population in the inflowing wastewater and the treated outflow water were quantified for each of the treatment modules (fecal coliforms, fecal streptococci, Salmonella spp. (presence/absence), Clostridium Sulphite-reducers, Pseudomonas aeruginosa, Staphylococcus aureus, coliphages, nematodes, intestinal nematodes and pathogenic fungi). Treated water was stored in opaque tanks at a temperature between 20 and 22 degrees C, after which, a one-month study of the regrowth of the bacterial flora, nematodes and fungi was carried out. Clostridium Sulphite-reducers, pathogenic fungi and nematodes were the micro-organisms showing a greatest degree of resistence to UV- and Ozone-treatment. It was only concerning Clostridium and Pseudomonas abatement that significant elimination results were achieved with both technologies.

  18. The Use of Ozone in High Frequency Device to Treat Hand Ulcers in Leprosy: a Case Study.

    Science.gov (United States)

    Reis, Felipe J J; Correia, Helia; Nagen, Roberto; Gomes, Maria Kátia

    2015-09-01

    Leprosy leads to chronic granulomatous inflammation in skin and peripheral nerves that can lead to sensory, motor and autonomic impairments. Autonomic dysfunctions may result in dryness and cracking of the skin. In this study, we present the use of ozone provided by a high-frequency device to treat hand ulcers (wounds) in an 80-year-old man who was diagnosed as multibacillary in 2007. In the first visit, the patient was evaluated and received verbal and written instructions about self-care. Treatment consisted of five sessions, once per week. The ozone provided by a high-frequency device seemed to be useful in the treatment of ulcers, thus, contributing to the healing process. Research that investigates the use of high frequencies in the treatment of ulcers associated or not with other interventions (self-care strategies, protective clothing, adapted tools and footwear adaptation) is strongly recommended.

  19. Biomarkers of Oxidative Stress Study V: Ozone exposure of rats and its effect on lipids, proteins and DNA in plasma and urine

    Science.gov (United States)

    Kadiiska, Maria B.; Basu, Samar; Brot, Nathan; Cooper, Christopher; Csallany, A. Saari; Davies, Michael J.; George, Magdalene M.; Murray, Dennis M.; Roberts, L. Jackson; Shigenaga, Mark K.; Sohal, Rajindar S.; Stocker, Roland; Van Thiel, David H.; Wiswedel, Ingrid; Hatch, Gary E.; Mason, Ronald P.

    2014-01-01

    Ozone exposure effect on free radical-catalyzed oxidation products of lipids, proteins and DNA in the plasma and urine of rats was studied as a continuation of the international Biomarker of Oxidative Stress Study (BOSS) sponsored by NIEHS/NIH. The goal was to identify a biomarker for ozone-induced oxidative stress and to assess whether inconsistent results often reported in the literature might be due to the limitations of the available methods for measuring the various types of oxidative products. The time and dose-dependent effects of ozone exposure on rat plasma lipid hydroperoxides, malondialdehyde, F2-isoprostanes, protein carbonyls, methionine oxidation, tyrosine- and phenylalanine oxidation products, as well as urinary malondialdehyde and F2-isoprostanes were investigated with various techniques. The criterion used to recognize a marker in the model of ozone exposure was that a significant effect could be identified and measured in a biological fluid seen at both doses at more than one time point. No statistically significant differences between the experimental and control groups at either ozone dose and time point studied could be identified in this study. Tissue samples were not included. Despite all the work accomplished in the BOSS study of ozone, no available product of oxidation in biological fluid has yet met the required criteria of being a biomarker. The current negative findings as a consequence of ozone exposure are of great importance, because they document that in complex systems, as the present in vivo experiment, the assays used may not provide meaningful data of ozone oxidation, especially in human studies. PMID:23608465

  20. Cerebrovascular pattern improved by ozone autohemotherapy: an entropy-based study on multiple sclerosis patients.

    Science.gov (United States)

    Molinari, Filippo; Rimini, Daniele; Liboni, William; Acharya, U Rajendra; Franzini, Marianno; Pandolfi, Sergio; Ricevuti, Giovanni; Vaiano, Francesco; Valdenassi, Luigi; Simonetti, Vincenzo

    2017-08-01

    Ozone major autohemotherapy is effective in reducing the symptoms of multiple sclerosis (MS) patients, but its effects on brain are still not clear. In this work, we have monitored the changes in the cerebrovascular pattern of MS patients and normal subjects during major ozone autohemotherapy by using near-infrared spectroscopy (NIRS) as functional and vascular technique. NIRS signals are analyzed using a combination of time, time-frequency analysis and nonlinear analysis of intrinsic mode function signals obtained from empirical mode decomposition technique. Our results show that there is an improvement in the cerebrovascular pattern of all subjects indicated by increasing the entropy of the NIRS signals. Hence, we can conclude that the ozone therapy increases the brain metabolism and helps to recover from the lower activity levels which is predominant in MS patients.

  1. Influence of altitude on ozone levels and variability in the lower troposphere: a ground-based study for western Europe over the period 2001–2004

    Directory of Open Access Journals (Sweden)

    J.-M. Cousin

    2007-01-01

    Full Text Available The PAES (French acronym for synoptic scale atmospheric pollution network focuses on the chemical composition (ozone, CO, NOx/y and aerosols of the lower troposphere (0–3000 m. Its high-altitude surface stations located in different mountainous areas in France complete the low-altitude rural MERA stations (the French contribution to the european program EMEP, European Monitoring and Evaluation Program. They are representative of pollution at the scale of the French territory because they are away from any major source of pollution. This study deals with ozone observations between 2001 and 2004 at 11 stations from PAES and MERA, in addition to 16 elevated stations located in mountainous areas of Switzerland, Germany, Austria, Italy and Spain. The set of stations covers a range of altitudes between 115 and 3550 m. The comparison between recent ozone mixing ratios with those of the last decade found in the literature for two high-elevation sites (Pic du Midi, 2877 m and Jungfraujoch, 3580 m leads to a trend that has slowed down compared to old trends but remains positive. This could be attribuable to the reduction of ozone precursors at European scale, that however do not compensate an ozone increase at the global scale. Averaged levels of ozone increase with elevation in good agreement with data provided by the airborne observation system MOZAIC (Measurement of OZone and water vapour by Airbus In-service airCraft, showing a highly stratified ozone field in the lower troposphere, with a transition at about 1000 m asl between a sharp gradient (30 ppb/km below but a gentler gradient (3 ppb/km above. Ozone variability also reveals a clear transition between boundary-layer and free-tropospheric regimes at the same altitude. Below, diurnal photochemistry accounts for about the third of the variability in summer, but less than 20% above – and at all levels in winter – where ozone variability is mostly due to day-to-day changes (linked to weather

  2. [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.

  3. Solar response in tropical stratospheric ozone: a 3-D chemical transport model study using ERA reanalyses

    Directory of Open Access Journals (Sweden)

    S. Dhomse

    2011-05-01

    Full Text Available We have used an off-line 3-D chemical transport model (CTM, to investigate the 11-year solar cycle response in tropical stratospheric ozone. The model is forced with European Centre for Medium-Range Weather Forecasts (ECMWF (reanalysis (ERA-40/Operational and ERA-Interim data for 1978–2005 time period. We have compared the modelled solar response in ozone to observational data from three satellite instruments, Solar Backscatter UltraViolet instrument (SBUV, Stratospheric Aerosol and Gas Experiment (SAGE and Halogen Occultation Experiment (HALOE. A significant difference is seen between simulated and observed ozone during the 1980s, which is probably due to inhomogeneities in the ERA-40 reanalyses. In general, the model with ERA-Interim dynamics shows better agreement with the observations from 1990 onwards than ERA-40. Overall both standard model simulations are partially able to simulate a "double peak"-structured ozone solar response profile with a minimum around 30 km, and these are in better agreement with HALOE than SBUV or SAGE. The largest model-observation differences occur in the upper stratosphere where SBUV and SAGE show a significant (up to 4 % solar response whereas the standard model and HALOE do not. This is partly due to a positive solar response in the ECMWF upper stratosphere analysed temperatures which reduces the modelled ozone signal. The large positive upper stratosphere response seen in SAGE/SBUV can be reproduced in a model run with fixed dynamical fields (i.e. no inter-annual meteorological changes. As this run effectively assumes no long-term temperature changes (solar-induced or otherwise it should provide an upper limit of the ozone solar response. Overall, full quantification of the upper stratosphere ozone solar response is limited by differences in the observed dataset and by uncertainties in the solar response in the stratospheric temperatures. In the lower stratosphere we find that transport by analysed winds

  4. Proceedings of the NATO Advanced Study Institute on Atmospheric Ozone: Its Variation and Human Influences, Aldeia das Acoteias, Algarve, Portugal, October 1-13, 1979,

    Science.gov (United States)

    1980-05-01

    studies ( Piaget , 1971) or more directly measurements (Danielson and Mohnen, 1977) from airplanes have shown that strong intrusions predominantly occur n...Umkehr evaluation tech- nique, NCAR, Boulder, 1964. Piaget , A., Utilisation de l’ozone atmosph~rique comme traceur des 6changes entre la troposphere...due to ozone absorp- tion, J. Atmos. Sci., 30, 513-515, 1973. Louis, Jean -Francois, A two-dimensional transport model of the atmosphere, PhD thesis

  5. Ozone therapy on Otorhinolaryngology. A five-year study. Ozonoterapia en Otorrinolaringología. Estudio de cinco años.

    OpenAIRE

    Alejandro Díaz González; Juan M. Salomón Bacallao; Armando Figueroa Hernández

    2005-01-01

    Fundament: The ample active spectre of ozone in medicine is based in a series of properties that positively influence certain metabolic processes, whose alterations are cause for many diseases. Methods: Prospective-descriptive study about the treatment with ozone, besides the conventional therapeutics, to patients bearing affections of possible vascular ethiology as acufenos, peripheral vertiginous syndrome...

  6. Stratospheric ozone

    Directory of Open Access Journals (Sweden)

    M. Gil

    2006-01-01

    Full Text Available Stratospheric ozone acquired a huge importance two decades ago because of the discovery of strong anomalies above the Antarctica due to gases of anthropogenic origin. From that date, stratosphere has become one of the research lines receiving more funding. A result, an important progress in the development of observational techniques, the understanding of the dynamics of the polar regions and, above all, in understanding of the chemical interactions among the species that influence the chemical-radiative balance of ozone. In this article a general revision is made of the distribution of the ozone in the stratosphere, the mechanisms that determine its equilibrium, the gases that contribute to its destruction, the present situation and the forecast of the health state of the layer.

  7. Kinetics study of heterogeneous reactions of ozone with erucic acid using an ATR-IR flow reactor.

    Science.gov (United States)

    Leng, Chunbo; Hiltner, Joseph; Pham, Hai; Kelley, Judas; Mach, Mindy; Zhang, Yunhong; Liu, Yong

    2014-03-01

    The ozone initiated heterogeneous oxidation of erucic acid (EA) thin film was investigated using a flow system combined with attenuated total reflection infrared spectroscopy (ATR-IR) over wide ranges of ozone concentrations (0.25-60 ppm), thin film thickness (0.1-1.0 μm), temperatures (263-298 K), and relative humidities (0-80% RH) for the first time. Pseudo-first-order rate constants, kapp, and overall reactive uptake coefficients, γ, were obtained through changes in the absorbance of C[double bond, length as m-dash]O stretching bands at 1695 cm(-1), which is assigned to the carbonyl group in carboxylic acid. Results showed that the reaction followed the Langmuir-Hinshelwood mechanism and kapp was largely dominated by surface reaction over bulk phase reaction. In addition, both the kapp and the γ values showed very strong temperature dependences (∼two orders of magnitude) over the temperature range; in contrast, they only slightly increased with increasing RH values from 0-80%. According to the kapp values as a function of temperature, the activation energy for the heterogeneous reaction was estimated to be 80.6 kJ mol(-1). Our results have suggested that heterogeneous reactions between ozone and unsaturated solid surfaces likely have a substantially greater temperature dependence than liquid ones. Moreover, the hygroscopic properties of EA thin films before and after exposure to ozone were also studied by measurement of water uptake. Based on the hygroscopicity data, the insignificant RH effect on reaction kinetics was probably due to the relatively weak water uptake by the unreacted and reacted EA thin films.

  8. Study on Ozone Water Production system%高浓度臭氧水制备系统的研究

    Institute of Scientific and Technical Information of China (English)

    陈立波; 卜辛国; 王建刚

    2011-01-01

    Ozone water preparing system which constituted by Nikeni pump and dissolved gas tower was studied. When dissolved gas pressure stands at 0. 25MPa, the ozone dissolved ratio can exceed 90% . The systemcan be used to treat oil-field injection water, when the oxidation time arrives at 30min, the ozone added should be 8.8g/t, and the sterilization ratio of sulfate reducing bacteria, iron bacteria and saprophytic bacteria can reach A2 level stipulated for injecting water in middle-pervious bed.%使用尼可尼泵-溶气塔组成的臭氧水制备系统,在溶气塔压力为0.25MPa时,使臭氧溶解效率达到90%以上.该系统用于油田回注水的杀菌处理,在接触时间为30min时,臭氧投加量为8.8g/t,硫酸盐还原菌、铁细菌和腐生菌灭菌率可达到中等渗透油藏注入水A2级指标.

  9. Learning about ozone depletion

    Energy Technology Data Exchange (ETDEWEB)

    Crutzen, J. P. [Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz, Germany; Oppenheimer M. [Woodrow Wilson School of Public and International Affairs, Department of Geosciences, Princeton University, Princeton, NJ (United States)

    2008-07-15

    Stratospheric ozone depletion has been much studied as a case history in the interaction between environmental science and environmental policy. The positive influence of science on policy is often underscored, but here we review the photochemistry of ozone in order to illustrate how scientific learning has the potential to mislead policy makers. The latter may occur particularly in circumstances where limited observations are combined with simplified models of a complex system, such as may generally occur in the global change arena. Even for the well-studied case of ozone depletion, further research is needed on the dynamics of scientific learning, particularly the scientific assessment process, and how assessments influence the development of public policy.

  10. Understanding Tropospheric Ozone Variability in the Arctic

    Science.gov (United States)

    McClure-Begley, A.; Petropavlovskikh, I. V.; Crepinsek, S.; Uttal, T.; Skov, H.

    2016-12-01

    The Arctic is a region that has been subject to drastic changes in the climate partially due to transported pollutants which strongly impact the composition of the atmosphere and associated feedbacks. Tropospheric ozone is an atmospheric species formed by the reaction of precursor species (NOx, CO, VOC's) in the presence of UV radiation and drives complex interactions which can result in impacts on atmospheric conditions in the Arctic. As an important greenhouse gas, ozone has a significant influence on the photochemical characteristics, oxidation capacity, and radiative forcing of the atmosphere and at high levels has negative impacts on public health and overall ecosystem functioning. In the Arctic, tropospheric ozone has variable characteristics in time and space. Seasonal variation of ozone is controlled by many factors influencing the production and destruction of ozone. The arctic ozone conditions are strongly influenced by seasonal destruction events, arctic haze, transport of pollution from Asia and influence from precursor compounds released from wildfires. This study investigates long-term ozone variation, seasonal surface ozone conditions, and characterizes deviations from expected ozone levels at four arctic ozone measurement locations (Barrow Alaska, Tiksi Russia, Summit Greenland, and Villum Station Greenland). Frequency of ozone depletion events and high ozone episodes for each station over time provides a context for the changing conditions of ozone in the arctic. NOAA Hysplit back-trajectory analysis, satellite imagery, NOAA Smoke verification model, co-located carbon monoxide, carbon dioxide, and aerosol optical depth measurements are used to understand the dominant source of pollution, pollutant composition, and the interactions due to meteorological conditions that result in anomalies in the ozone mixing ratio records. Characterization of ozone behavior and influences on the measurement locations is essential for understanding the spatial and

  11. A Process-Analysis Based Study of the Ozone Weekend Effect

    Energy Technology Data Exchange (ETDEWEB)

    Tonse, Shaheen R.; Brown, Nancy J.; Harley, Robert A.; Jin, Ling

    2008-05-09

    We have used the 3D photochemical model CMAQ to simulate the ozone weekend effect, a phenomenon in which urban areas can have higher ozone concentrations on weekends than on weekdays even though NO{sub x} emissions are usually lower on weekends. A simulation containing a weekend is compared to hypothetical simulations in which the anthropogenic emissions for the weekend have been replaced by weekday emissions. The simulations are identical in all other respects. Process analysis is used to explain the results. We find that the weekend effect can be decomposed into an ozone titration component and an odd oxygen component, each contributing about half of the excess weekend ozone. The titration component simply requires that there be lower weekend NO{sub x} emissions. The odd oxygen component additionally requires that on weekends there be a higher rate of OH + (VOC or CO) reactions, brought about by one or more of lower nitric acid formation, higher OH formation from O{sub 3} photolysis, and higher VOC emissions. This causes higher weekend peroxy radical formation. The odd oxygen component also requires sufficiently high NO concentration even on the lower-NO{sub x} weekends to propagate this higher rate of peroxy formation back to higher weekend OH formation.

  12. FIELD STUDY: IN SITU OXIDATION OF 1,4-DIOXANE WITH OZONE AND HYDROGEN PEROXIDE

    Science.gov (United States)

    A pilot-scale field evaluation is underway to assess the effectiveness of in situ oxidation (using ozone with and without hydrogen peroxide) for remediation of 1,4-dioxane and chlorinated volatile organic compounds in groundwater at the Cooper Drum Company Superfund Site located ...

  13. Evolution of stratospheric ozone and water vapour time series studied with satellite measurements

    Directory of Open Access Journals (Sweden)

    A. Jones

    2009-01-01

    Full Text Available The long term evolution of stratospheric ozone and water vapour has been investigated by extending satellite time series to April 2008. For ozone, we examine monthly average ozone values from various satellite data sets for nine latitude and altitude bins covering 60° S to 60° N and 20–45 km and covering the time period 1979–2008. Data are from the Stratospheric Aerosol and Gas Experiment (SAGE I+II, the HALogen Occultation Experiment (HALOE, the Solar BackscatterUltraViolet-2 (SBUV/2 instrument, the Sub-Millimetre Radiometer (SMR, the Optical Spectrograph InfraRed Imager System (OSIRIS, and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartograpY (SCIAMACHY. Monthly ozone anomalies are calculated by utilising a linear regression model, which also models the solar, quasi-biennial oscillation (QBO, and seasonal cycle contributions. Individual instrument ozone anomalies are combined producing a weighted all instrument average. Assuming a turning point of 1997 and that the all instrument average is represented by good instrumental long term stability, the largest statistically significant ozone declines from 1979–1997 are seen at the mid-latitudes between 35 and 45 km, namely −7.7%/decade in the Northern Hemisphere and −7.8%/decade in the Southern Hemisphere. For the period 1997 to 2008 we find that the southern mid-latitudes between 35 and 45 km show the largest ozone recovery (+3.4%/decade compared to other global regions, although the estimated trend model error is of a similar magnitude (+2.1%/decade, at the 95% confidence level. An all instrument average is also constructed from water vapour anomalies during 1984–2008, using the SAGE II, HALOE, SMR, and the Microwave Limb Sounder (aura/MLS measurements. We report that the decrease in water vapour values after 2001 slows down around 2004 in the lower tropical stratosphere (20–25 km, and has even shown signs of increasing values in upper stratospheric mid

  14. Evolution of stratospheric ozone and water vapour time series studied with satellite measurements

    Directory of Open Access Journals (Sweden)

    A. Jones

    2009-08-01

    Full Text Available The long term evolution of stratospheric ozone and water vapour has been investigated by extending satellite time series to April 2008. For ozone, we examine monthly average ozone values from various satellite data sets for nine latitude and altitude bins covering 60° S to 60° N and 20–45 km and covering the time period of 1979–2008. Data are from the Stratospheric Aerosol and Gas Experiment (SAGE I+II, the HALogen Occultation Experiment (HALOE, the Solar BackscatterUltraViolet-2 (SBUV/2 instrument, the Sub-Millimetre Radiometer (SMR, the Optical Spectrograph InfraRed Imager System (OSIRIS, and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartograpY (SCIAMACHY. Monthly ozone anomalies are calculated by utilising a linear regression model, which also models the solar, quasi-biennial oscillation (QBO, and seasonal cycle contributions. Individual instrument ozone anomalies are combined producing an all instrument average. Assuming a turning point of 1997 and that the all instrument average is represented by good instrumental long term stability, the largest statistically significant ozone declines (at two sigma from 1979–1997 are seen at the mid-latitudes between 35 and 45 km, namely −7.2%±0.9%/decade in the Northern Hemisphere and −7.1%±0.9%/in the Southern Hemisphere. Furthermore, for the period 1997 to 2008 we find that the same locations show the largest ozone recovery (+1.4% and +0.8%/decade respectively compared to other global regions, although the estimated trend model errors indicate that the trend estimates are not significantly different from a zero trend at the 2 sigma level. An all instrument average is also constructed from water vapour anomalies during 1991–2008, using the SAGE II, HALOE, SMR, and the Microwave Limb Sounder (Aura/MLS measurements. We report that the decrease in water vapour values after 2001 slows down around 2004–2005 in the lower tropical stratosphere (20–25 km and has even

  15. Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

    Directory of Open Access Journals (Sweden)

    Z. A. Kanji

    2013-04-01

    Full Text Available Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T and relative humidity (RH, as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulphate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 T ns are reported and observed to increase as a function of temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. Additionally, these are also the first results to show a suppression of heterogeneous ice nucleation without the condensation of a coating of (inorganic material. In immersion mode, low exposure Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka whereas high exposure ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low exposure Ka had ice active fractions of an order of magnitude higher than untreated Ka, where as high exposure ATD had ice active fractions up to a factor of 4 lower than untreated ATD. Based on our results, we present parameterizations in terms of ns(T that can represent ice nucleation of atmospherically aged and non-aged particles for both immersion and deposition mode. We find excellent agreement (to within less than a factor of 2 with field measurements when parameterizations derived from our results are used to

  16. Ozone production efficiency of a ship-plume: ITCT 2K2 case study.

    Science.gov (United States)

    Kim, Hyun S; Kim, Yong H; Han, Kyung M; Kim, Jhoon; Song, Chul H

    2016-01-01

    Ozone production efficiency (OPE) of ship plume was first evaluated in this study, based on ship-plume photochemical/dynamic model simulations and the ship-plume composition data measured during the ITCT 2K2 (Intercontinental Transport and Chemical Transformation 2002) aircraft campaign. The averaged instantaneous OPEs (OPE(i)‾) estimated via the ship-plume photochemical/dynamic modeling for the ITCT 2K2 ship-plume ranged between 4.61 and 18.92, showing that the values vary with the extent of chemical evolution (or chemical stage) of the ship plume and the stability classes of the marine boundary layer (MBL). Together with OPE(i)‾, the equivalent OPEs (OPE(e)‾) for the entire ITCT 2K2 ship-plume were also estimated. The OPE(e)‾ values varied between 9.73 (for the stable MBL) and 12.73 (for the moderately stable MBL), which agreed well with the OPE(e)‾ of 12.85 estimated based on the ITCT 2K2 ship-plume observations. It was also found that both the model-simulated and observation-based OPE(e)‾ inside the ship-plume were 0.29-0.38 times smaller than the OPE(e)‾ calculated/measured outside the ITCT 2K2 ship-plume. Such low OPEs insides the ship plume were due to the high levels of NO and non-liner ship-plume photochemistry. Possible implications of this ship-plume OPE study in the global chemistry-transport modeling are also discussed.

  17. Modeling of meteorology, tracer transport and chemistry for the Uintah Basin Winter Ozone Studies 2012 and 2013

    Science.gov (United States)

    Ahmadov, R.; McKeen, S. A.; Angevine, W. M.; Frost, G. J.; Roberts, J. M.; De Gouw, J. A.; Warneke, C.; Peischl, J.; Brown, S. S.; Edwards, P. M.; Wild, R. J.; Pichugina, Y. L.; Banta, R. M.; Brewer, A.; Senff, C. J.; Langford, A. O.; Petron, G.; Karion, A.; Sweeney, C.; Schnell, R. C.; Johnson, B.; Zamora, R. J.; Helmig, D.; Park, J.; Evans, J.; Stephens, C. R.; Olson, J. B.; Trainer, M.

    2013-12-01

    The Uintah Basin Winter Ozone Studies (UBWOS) field campaigns took place during winter of 2012 and 2013 in the Uintah Basin, Utah. The studies were aimed at characterizing meteorology, emissions of atmospheric constituents and air chemistry in a region abundant with oil and gas production, with associated emissions of various volatile organic compounds (VOCs) and NOx. High ozone pollution events were observed throughout the Uintah Basin during the winter of 2013, but not during the winter of 2012. A clear understanding of the processes leading to high ozone events is still lacking. We present here high spatiotemporal resolution simulations of meteorology, tracer transport and gas chemistry over the basin during January-February, 2012 and 2013 using the WRF/Chem regional photochemical model. Correctly characterizing the meteorology poses unique challenges due to complex terrain, cold-pool conditions, and shallow inversion layers observed during the winter of 2013. We discuss the approach taken to adequately simulate the meteorology over the basin and present evaluations of the modeled meteorology using surface, lidar and tethersonde measurements. Initial simulations use a passive tracer within the model as a surrogate for CH4 released from oil and gas wells. These tracer transport simulations show that concentrations of inert, emitted species near the surface in 2013 were 4-8 times higher than 2012 due to much shallower boundary layers and reduced winds in 2013. This is supported by in-situ measurements of CH4 made at the Horse Pool surface station during the field campaigns. Full photochemical simulations are forced by VOC and NOx emissions that are determined in a top-down approach, using observed emission ratios of VOC and NOx relative to CH4, along with available information of active wells, compressors, and processing plants. We focus on differences in meteorology, temperature, and radiation between the two winters in determining ozone concentrations in the

  18. Plant injury induced by ozone

    Energy Technology Data Exchange (ETDEWEB)

    Hill, A.C.; Pack, M.R.; Treshow, M.; Downs, R.J.; Transtrum, L.G.

    1961-06-01

    Phytotoxicity of ozone to 34 plant species was studied in controlled-atmosphere greenhouses. Plants were subjected at various stages of growth to 0.13-0.72 ppm ozone for 2-hour periods. Injury symptoms developed on 28 species. Some of the most sensitive species were small grains, alfalfa, spinach, and tobacco. There was a general tendency for sensitivity to increase with maturity of tissue. Palisade cells were most readily injured by ozone. On plants with adaxial palisade parenchyma, chlorotic spots and bleached necrotic areas developed on the upper leaf surface. Injury was equally apparent from either leaf surface of plants with undifferentiated mesophyll. Necrotic spots extending completely through the leaf developed on plants with either mesophyll structure when injury was severe. Ozone caused conspicuous tumors to develop on broccoli leaves. Symptoms similar to those produced by ozone fumigations have been observed on a wide range of plant species growing near several large metropolitan centers. 18 references, 8 figures, 2 tables.

  19. Ozone's impact on public health: Contributions from indoor exposures to ozone and products of ozone-initiated chemistry

    DEFF Research Database (Denmark)

    Weschler, Charles J.

    2006-01-01

    , if any, threshold for ozone's impact on mortality. Additionally, the present study estimates that average daily indoor intakes of ozone oxidation products are roughly one-third to twice the indoor inhalation intake of ozone alone. Some of these oxidation products are known or suspected to adversely...... affect human health (e.g., formaldehyde, acrolein, hydro-peroxides, fine and ultrafine particles). Indirect evidence supports connections between morbidity/mortality and exposures to indoor ozone and its oxidation products. For example, cities with stronger associations between outdoor ozone...

  20. Ozone and cardiovascular injury

    Directory of Open Access Journals (Sweden)

    Rainaldi Giuseppe

    2009-06-01

    Full Text Available Abstract Air pollution is increasingly recognized as an important and modifiable determinant of cardiovascular diseases in urban communities. The potential detrimental effects are both acute and chronic having a strong impact on morbidity and mortality. The acute exposure to pollutants has been linked to adverse cardiovascular events such as myocardial infarction, heart failure and life-threatening arrhythmias. The long-terms effects are related to the lifetime risk of death from cardiac causes. The WHO estimates that air pollution is responsible for 3 million premature deaths each year. The evidence supporting these data is very strong nonetheless, epidemiologic and observational data have the main limitation of imprecise measurements. Moreover, the lack of clinical experimental models makes it difficult to demonstrate the individual risk. The other limitation is related to the lack of a clear mechanism explaining the effects of pollution on cardiovascular mortality. In the present review we will explore the epidemiological, clinical and experimental evidence of the effects of ozone on cardiovascular diseases. The pathophysiologic consequences of air pollutant exposures have been extensively investigated in pulmonary systems, and it is clear that some of the major components of air pollution (e.g. ozone and particulate matter can initiate and exacerbate lung disease in humans 1. It is possible that pulmonary oxidant stress mediated by particulate matter and/or ozone (O3 exposure can result in downstream perturbations in the cardiovasculature, as the pulmonary and cardiovascular systems are intricately associated, and it is well documented that specific environmental toxins (such as tobacco smoke 2 introduced through the lungs can initiate and/or accelerate cardiovascular disease development. Indeed, several epidemiologic studies have proved that there is an association between PM and O3 and the increased incidence of cardiovascular morbidity

  1. Aspectos da bananicultura no litoral norte paulista estudados através de fotografias aéreas Some characteristics of banana plantations on the northern coast of São Paulo studied through aerial photographs

    Directory of Open Access Journals (Sweden)

    Arnaldo Guido de Souza Coelho

    1966-01-01

    Full Text Available São relatados estudos efetuados nos municípios de São Sebastião, Caraguatatuba e Ubatuba, no litoral Norte do Estado de São Paulo, relativos à distribuição da cultura da bananeira. Os trabalhos foram executados com apoio em fotografias aéreas verticais, tiradas em 1962, na escala aproximada de 1:25.000. Estimaram-se os totais de 2.606 ha, ocupados por 2.377.500 pés de bananeira, localizados, quase totalmente, em solos das partes baixas da região. Cêrca de 60% da área plantada e 70% do total de pés estão localizados no município de Caraguatatuba. Correlações de clima, solo e outras de interêsse para a cultura foram efetuadas.There are reported studies carried out in the counties of São Sebastião, Caraguatatuba and Ubatuba, on the north coast of the State of São Paulo, relative to distribution of banana cultures. Work was done with the help of vertical aerial photographs taken in 1962 on the approximate scale of 1:25,000. A total of 2,606 ha was estimated holding 2,377,500 banana plants, located almost in their totality on soils of the lowlands of the region. About 60% of the planted area and 70% of the total of plants are located in the Caraguatatuba county. Correlations of climate, soil and others of interest for this crop have been worked out.

  2. Ozonides: intermediates in ozone-induced toxicity. A study on their mechanism of toxic action and detoxification by antioxidants

    NARCIS (Netherlands)

    Hempenius, R.A.

    2000-01-01

    Ozone is a major constituent of photochemical smog. The toxicity of ozone is well documented and has been related to its strong oxidative potential. The principal target organ for ozone toxicity is the respiratory system. Unsaturated fatty acids, which are present in both the lipids of the lung lini

  3. Effect of ozonation of swimming pool water on formation of volatile disinfection by-products - A laboratory study

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Cheema, Waqas Akram;

    2016-01-01

    byproducts during subsequent chlorination. The ozone reaction was observed to behave according to first order kinetics. For tap water half-life was 4 min whilst polluted and unpolluted pool water exhibited half-life of 8 and 11 min, respectively. When ozonation dosage was repeated half-life of ozone...

  4. The Antarctic Ozone Hole

    Science.gov (United States)

    Jones, Anna E.

    2008-01-01

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For…

  5. Ozone pollution and ozone biomonitoring in European cities Part II. Ozone-induced plant injury and its relationship with descriptors of ozone pollution

    DEFF Research Database (Denmark)

    Klumpp, A.; Ansel, W.; Klumpp, G.

    2006-01-01

    Within the scope of a biomonitoring study conducted in twelve urban agglomerations in eight European countries, the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was employed in order to assess the occurrence of phytotoxic ozone effects at urban, suburban, rural and traffic....... This is because the actual ozone flux into the leaf, which is modified by various environmental factors, rather than ambient ozone concentration determines the effects on plants. The advantage of sensitive bioindicators like tobacco Bel-W3 is that the impact of the effectively absorbed ozone dose can directly...

  6. Hongos basidiomycetes: una contribución al conocimiento de 14 generos en norte de santander

    Directory of Open Access Journals (Sweden)

    Nancy Jackeline Sanchez-Sandoval

    2006-07-01

    Full Text Available In this article 14 genera of Basidiomycetes are reported tor Norte de Santander Department. These genera belong to 10 families and 5 orders: Agaricales, Boletales, Schizophyllales, Polyporales and Lycoperdales. The last order belongs to Gasteromycetes. The study was done in Chinócota county, during the years 2003-2004.

  7. Determining sex and life stage of Del Norte salamanders from external cues

    Science.gov (United States)

    Lisa Ollivier; Hartwell H. Welsh Jr

    2003-01-01

    Life stage determination for many western plethodontids often requires dissection of the specimen. Availability of reliable external measures that could be applied under field conditions would enhance future studies of the genus Plethodon. We examined preserved specimens of the Del Norte Salamander, Plethodon elongatus, taken from...

  8. OZONE CONCENTRATION ATTRIBUTABLE PREMATURE DEATH IN POLAND

    Directory of Open Access Journals (Sweden)

    Krzysztof Skotak

    2010-03-01

    Full Text Available Ozone in the lower part of the atmosphere (troposphere, strong photochemical oxidant, is not directly emitted to the atmosphere but formed through a series of complex reactions. Ozone concentrations depends on ozone precursors air contamination (mainly nitrogen dioxide and non-methane volatile organic compounds and meteorological conditions (temperature and solar radiation. The main sectors emitted ozone precursors are road transport, power and heat generation plants, household (heating, industry, and petrol storage and distribution. Ozone and some of its precursors are also transported long distances in the atmosphere and are therefore considered a transboundary problem. As a result, the ozone concentrations are often low in busy urban areas and higher in suburban and rural areas. Nowadays, instead of particulate matter, ozone is one of the most widespread global air pollution problems. In and around urban areas, relatively large gradients of ozone can be observed. Because of its high reactivity in elevated concentrations ozone causes serious health problems and damage to ecosystems, agricultural crops and materials. Main ill-health endpoints as a results of ozone concentrations can be characterised as an effect of pulmonary and cardiovascular system, time morbidity and mortality series, development of atherosclerosis and asthma and finally reduction in life expectancy. The associations with increased daily mortality due to ozone concentrations are confirmed by many researches and epidemiological studies. Estimation of the level selected ill-health endpoints (mortality in total and due to cardiovascular and respiratory causes as a result of the short-term ozone exposure in Poland was the main aim of the project. Final results have been done based on estimation method elaborated by WHO, ozone measurements from National Air Quality Monitoring System and statistical information such as mortality rate and populations. All analysis have been done in

  9. Ozone Reductions Using Residential Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Sherman, Max; Nazaroff, William W.

    2009-02-01

    Ozone is an air pollutant with that can have significant health effects and a significant source of ozone in some regions of California is outdoor air. Because people spend the vast majority of their time indoors, reduction in indoor levels of ozone could lead to improved health for many California residents. Ozone is removed from indoor air by surface reactions and can also be filtered by building envelopes. The magnitude of the envelope impact depends on the specific building materials that the air flows over and the geometry of the air flow paths through the envelope that can be changes by mechanical ventilation operation. The 2008 Residential Building Standards in California include minimum requirements for mechanical ventilation by referencing ASHRAE Standard 62.2. This study examines the changes in indoor ozone depending on the mechanical ventilation system selected to meet these requirements. This study used detailed simulations of ventilation in a house to examine the impacts of different ventilation systems on indoor ozone concentrations. The simulation results showed that staying indoors reduces exposure to ozone by 80percent to 90percent, that exhaust ventilation systems lead to lower indoor ozone concentrations, that opening of windows should be avoided at times of high outdoor ozone, and that changing the time at which mechanical ventilation occurs has the ability to halve exposure to ozone. Future work should focus on the products of ozone reactions in the building envelope and the fate of these products with respect to indoor exposures.

  10. Towards the retrieval of tropospheric ozone with the ozone monitoring instrument (OMI)

    NARCIS (Netherlands)

    Mielonen, T.; De Haan, J...F.; Van Peet, J.C.A.; Eremenko, M.; Veefkind, J.P.

    2015-01-01

    We have assessed the sensitivity of the operational Ozone Monitoring Instrument (OMI) ozone profile retrieval algorithm to a number of a priori and radiative transfer assumptions. We studied the effect of stray light correction, surface albedo assumptions and a priori ozone profiles on the retrieved

  11. Earth's Endangered Ozone

    Science.gov (United States)

    Panofsky, Hans A.

    1978-01-01

    Included are (1) a discussion of ozone chemistry; (2) the effects of nitrogen fertilizers, fluorocarbons, and high level aircraft on the ozone layer; and (3) the possible results of a decreasing ozone layer. (MR)

  12. A brief history of stratospheric ozone research

    Directory of Open Access Journals (Sweden)

    Rolf Müller

    2009-03-01

    Full Text Available Ozone is one of the most important trace species in the atmosphere. Therefore, the history of research on ozone has also received a good deal of attention. Here a short overview of ozone research (with a focus on the stratosphere is given, starting from the first atmospheric measurements and ending with current developments. It is valuable to study the history of ozone research, because much can be learned for current research from an understanding of how previous discoveries were made. Moreover, since the 1970s, the history of ozone research has also encompassed also the history of the human impact on the ozone layer and thus the history of policy measures taken to protect the ozone layer, notably the Montreal Protocol and its amendments and adjustments. The history of this development is particularly important because it may serve as a prototype for the development of policy measures for the protection of the Earth's climate.

  13. Tropospheric and Stratospheric Ozone From Assimilation of Aura Data

    Science.gov (United States)

    Stajner, I.; Wargan, K.; Chang, L.; Hayashi, H.; Pawson, S.; Froidevaux, L.; Livesey, N.; Bhartia, P. K.; Bowman, K.

    2006-05-01

    Ozone is an atmospheric trace gas with multiple impacts on the environment. Global ozone fields are needed for air quality predictions, estimation of the ultraviolet radiation reaching the surface, climate-radiation studies, and ozone may also have an impact on longer-term weather predictions. We estimate global ozone fields in the stratosphere and troposphere by combining the data from the EOS Aura satellite with an ozone model using data assimilation. Ozone exhibits a large temporal variability in the lower stratosphere. Our previous work showed that assimilation of satellite data from limb-sounding geometry helps constrain ozone profiles in that region. We assimilated ozone data from the Aura Microwave Limb Sounder (MLS) and the Ozone Monitoring Instrument (OMI) into the ozone system at NASA's Global Modeling and Assimilation Office (GMAO). Ozone is transported within a general circulation model (GCM) which includes parameterizations for stratospheric photochemistry, tropospheric chemistry, and a simple scheme for heterogeneous ozone loss. The focus of this study is on the representation of ozone in the lower stratosphere and tropospheric ozone columns. We plan to extend studies of tropospheric ozone distribution through assimilation of ozone data from the Tropospheric Emission Spectrometer (TES). Comparisons with ozone sondes and occultation data show that assimilation of Aura data provides a good representation of ozone gradients and variability in the lower stratosphere. We proceed by separating the contributions to temporal changes in the ozone field into those that are due to the model and those that are due to the assimilation of Aura data. We discuss the impacts of Aura data and their role in the representation of ozone variability in the lower stratosphere and troposphere.

  14. Retrieval of stratospheric ozone profiles from MIPAS/ENVISAT limb emission spectra: a sensitivity study

    Directory of Open Access Journals (Sweden)

    N. Glatthor

    2005-11-01

    Full Text Available We report on the dependance of ozone volume mixing ratio profiles, retrieved from spectra of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS, on different retrieval setups such as different a-priori profiles, regularization strengths and spectral regions used for analysis. MIPAS is a spaceborne limb-viewing Fourier transform infrared (FTIR emission spectrometer, by which vertical profiles of various trace gases can be measured simultaneously. Purpose of this investigation is to check and to optimize the current retrieval setup. The choice of different a-priori profiles, of a different approach to retrieve the continuum radiation, and of a weaker regularization than in the reference data version (V2_O3_2 causes only small to moderate deviations of up to ±0.2, −0.3 and ±0.5 ppmv, respectively, in the retrieved ozone volume mixing ratios below 60 km altitude. Use of different microwindow sets optimized for polar, mid-latitude and tropical conditions results in deviations of up to ±1.5 ppmv in the altitude region of the ozone maximum, exceeding the total estimated retrieval error of 0.65 ppmv (polar regions – 1.2 ppmv (tropics in this height region. Therefore, to avoid latitudinal artefacts, one fixed set of microwindows is considered more appropriate for retrieval of a whole orbit rather than a latitude-dependent microwindow selection. For this task the microwindow set optimized for the polar atmosphere was found to be better suitable than its midlatitude and tropical counterparts. The results from the different microwindow sets, which variably cover MIPAS spectral bands A (685–970 cm−1 and AB (1020–1170 cm−1, indicated a positive bias of up to 1ppmv between the ozone maxima retrieved from the ozone emission in MIPAS band AB only and from combined analysis of MIPAS bands A and AB. Further investigations showed that this discrepancy can be caused by a bias between the radiance calibration of

  15. PROTAGONISMO DOS ÍNDIOS NORTE-AMERICANOS NOS DESENHOS ANIMADOS DE WALTER LANTZ

    Directory of Open Access Journals (Sweden)

    RAFAEL DUARTE OLIVEIRA VENANCIO

    2011-06-01

    Full Text Available Condemned to a dubious media representation in early cinema through thenovels of the late nineteenth century, the North American Indians never had a high profile infilms of this period. However, an animator, Walter Lantz, has a high degree of characterizationof Native Americans in his work. The aim of this paper is to study the role of Native Americansin these cartoons and analyze the social implications of these choices, using the concepts ofapparatus and formula. Furthermore, the analysis will include a portrayal of the Americanmedia scene before and after Lantz, seeking disruptions and legacies.Condenados a uma duvidosa representação midiática no início do cinema graçasaos romances do final do século XIX, os índios norte-americanos nunca tiveram um grandedestaque nos filmes dessa época. No entanto, um realizador de desenhos animados, WalterLantz, possui um alto grau de caracterização de nativos norte-americanos em seus trabalhos. Oobjetivo do presente artigo é estudar o protagonismo dos índios norte-americanos nessesdesenhos animados, e analisar as implicações sociais dessas escolhas através do uso dosconceitos de dispositivo e fórmula. Além disso, a análise incluirá a retratação da cenamidiática norte-americana antes e depois de Lantz, buscando rupturas e legados.

  16. Influence of altitude on ozone levels and variability in the lower troposphere: a ground-based study for western Europe over the period 2001─2004

    Directory of Open Access Journals (Sweden)

    J.-M. Cousin

    2007-08-01

    Full Text Available The PAES (French acronym for synoptic scale atmospheric pollution network focuses on the chemical composition (ozone, CO, NOx/y and aerosols of the lower troposphere (0–3000 m. Its high-altitude surface stations located in different mountainous areas in France complete the low-altitude rural MERA stations (the French contribution to the european program EMEP, European Monitoring and Evaluation Program. They are representative of pollution at the scale of the French territory because they are away from any major source of pollution. This study deals with ozone observations between 2001 and 2004 at 11 stations from PAES and MERA, in addition to 16 elevated stations located in mountainous areas of Switzerland, Germany, Austria, Italy and Spain. The set of stations covers a range of altitudes between 115 and 3550 m. The comparison between recent ozone mixing ratios to those of the last decade at Pic du Midi (2877 m, as well as trends calculated over 14-year data series at three high-altitude sites in the Alps (Jungfraujoch, Sonnblick and Zugspitze reveal that ozone is still increasing but at a slower rate than in the 1980s and 1990s. The 2001–2004 mean levels of ozone from surface stations capture the ozone stratification revealed by climatological profiles from the airborne observation system MOZAIC (Measurement of OZone and water vapour by Airbus In-service airCraft and from ozone soundings above Payerne (Switzerland. In particular all data evidence a clear transition at about 1000–1200 m a.s.l. between a sharp gradient below (of the order of +30 ppb/km and a gentler gradient (+3 ppb/km above. The same altitude (1200 m is also found to be a threshold regarding how well the ozone levels at the surface stations agree with the free-tropospheric reference (MOZAIC or soundings. Below the departure can be as large as 40%, but suddenly drops within 15% above. For stations above 2000 m, the departure is even less than 8%. Ozone variability also

  17. Comparative scenario study of tropospheric ozone climate interactions using a global model. A 1% global increase rate, the IS92a IPCC scenario and a simplified aircraft traffic increase scenario

    Energy Technology Data Exchange (ETDEWEB)

    Chalita, S. [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France). Service d`Aeronomie; Le Treut, H. [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France). Lab. de Meteorologie Dynamique

    1997-12-31

    Sensitivity studies have been made to establish the relationship between different scenarios of tropospheric ozone increase and radiative forcing. Some aspects of the ozone-climate interactions for past and future scenarios are investigated. These calculations employ IMAGES tropospheric ozone concentrations for a pre-industrial, present and future atmospheres. The averaged last 10 years of the 25-year seasonal integrations were analyzed. The results of this study are preliminary. Ozone forcing is basically different from the CO{sub 2} forcing, for its regional and temporal structured nature and for its rather weak intensity. (R.P.) 14 refs.

  18. Ozone adsorption on carbon nanoparticles

    Science.gov (United States)

    Chassard, Guillaume; Gosselin, Sylvie; Visez, Nicolas; Petitprez, Denis

    2014-05-01

    Carbonaceous particles produced by incomplete combustion or thermal decomposition of hydrocarbons are ubiquitous in the atmosphere. On these particles are adsorbed hundreds of chemical species. Those of great concern to health are polycyclic aromatic hydrocarbons (PAHs). During atmospheric transport, particulate PAHs react with gaseous oxidants. The induced chemical transformations may change toxicity and hygroscopicity of these potentially inhalable particles. The interaction between ozone and carbon particles has been extensively investigated in literature. However ozone adsorption and surface reaction mechanisms are still ambiguous. Some studies described a fast catalytic decomposition of ozone initiated by an atomic oxygen chemisorption followed by a molecular oxygen release [1-3]. Others suggested a reversible ozone adsorption according to Langmuir-type behaviour [4,5]. The aim of this present study is a better understanding of ozone interaction with carbon surfaces. An aerosol of carbon nanoparticles was generated by flowing synthetic air in a glass tube containing pure carbon (primary particles p. 967-973. [2] Smith, D. and A. Chughtai, Reaction kinetics of ozone at low concentrations with n-hexane soot. Journal of geophysical research, 1996. 101(D14): p. 19607-19,620. [3] Kamm, S., et al., The heterogeneous reaction of ozone with soot aerosol. Atmospheric Environment, 1999. 33(28): p. 4651-4661. [4] Stephens, S., M.J. Rossi, and D.M. Golden, The heterogeneous reaction of ozone on carbonaceous surfaces. International journal of chemical kinetics, 1986. 18(10): p. 1133-1149. [5] Pöschl, U., et al., Interaction of ozone and water vapor with spark discharge soot aerosol particles coated with benzo [a] pyrene: O3 and H2O adsorption, benzo [a] pyrene degradation, and atmospheric implications. The Journal of Physical Chemistry A, 2001. 105(16): p. 4029-4041.

  19. Ozone Applications in Food Industry

    Directory of Open Access Journals (Sweden)

    Elif Savaş

    2014-03-01

    Full Text Available Known as active oxygen Ozone (O3, are among the most effective antimicrobials. The sun's ultraviolet rays and ozone caused by electric arcs of lightning occurring instantly around the world, and is available as a protective shield protects the animals against the effects of the sun's radiation. In the food industry, directly or indirectly in contact with food during processing of foods and chemical treatment of water disinfection bacteriological emerges as an alternative protection method. In this study, the effects of the ozone applications will evaluated as an alternative to conventional disinfectants in food industry.

  20. Hydrophobic recovery of UV/ozone treated poly(dimethylsiloxane): adhesion studies by contact mechanics and mechanism of surface modification

    Science.gov (United States)

    Oláh, Attila; Hillborg, Henrik; Vancso, G. Julius

    2005-01-01

    Silicone elastomers (Sylgard 184 and 170), based on poly(dimethylsiloxane) (PDMS), were surface treated by a combined exposure to UV and ozone. The effects of the treatments were analyzed as a function of time elapsed after stopping the treatments using different standard surface characterization techniques, such as water contact angle measurements, XPS and atomic force microscopy (AFM). However, the primary focus of this study was to apply the Johnson-Kendall-Roberts (JKR) contact mechanics approach to investigate PDMS samples prior to and following UV/ozone surface treatment. A gradual formation of a hydrophilic, silica-like surface layer with increasing modulus was observed with increasing UV/ozone exposure. A subsequent hydrophobic recovery after UV/ozone exposure was observed, as indicated by increasing contact angles. This supports the hypothesis that the hydrophobic recovery is mainly caused by the gradual coverage of a permanent silica-like structure with free siloxanes and/or reorientation of polar groups. PDMS containing a homogenously dispersed filler (Sylgard 184), exhibited a decreasing surface roughness (by AFM) when the oxidized surface region "collapsed" into a smooth SiO x layer (final surface roughness Sylgard 170), exhibited an increasing surface roughness with treatment dose, which was attributed to the "collapse" of the oxidized surface region thus exposing the contours of the underlying filler aggregates (final surface roughness ˜140 nm). A dedicated device was designed and built to study the contact mechanics behavior of PDMS prior to, and following surface treatment. The value of the combined elastic modulus obtained for PDMS lens and semi-infinite flat surface system showed an increase in full agreement with the formation of a silica-like layer exhibiting a high elastic modulus (compared with untreated PDMS). The work of adhesion observed in JKR experiments exhibited an increasing trend as a function of treatment done in agreement with

  1. STUDIES ON THE METHOD OF PRODUCING OZONE WATER SOLUTION WITH HIGH SOLUBILITY AND HIGH-CONCENTRATION%取得高溶解率和高浓度臭氧水的方法

    Institute of Scientific and Technical Information of China (English)

    白敏冬; 沈丽; 左军; 白希尧

    2001-01-01

    The studies and its wide applying prospects of ozone watersolution were described, and some methods which produce high-concentration ozone gas, effctively dissolven ozone gas into water, and achieve ozone water solution are introduced in this paper. With these methods, the concentration of ozone water and the efficiency of ozone solution reach over 8g/m3 and 98% respectively.%本文介绍了臭氧水溶液研究的进展及其广泛诱人的应用前景,同时阐叙了产生高浓度臭氧、高效率溶解臭氧及制取臭氧水溶液等方法。利用这些方法,臭氧水溶液的臭氧浓度达8g/m3,臭氧溶解率达98%以上。

  2. Characterizing ozone pollution in a petrochemical industrial area in Beijing, China: a case study using a chemical reaction model.

    Science.gov (United States)

    Wei, Wei; Lv, Zhaofeng; Cheng, Shuiyuan; Wang, Lili; Ji, Dongsheng; Zhou, Ying; Han, Lihui; Wang, Litao

    2015-06-01

    This study selected a petrochemical industrial complex in Beijing, China, to understand the characteristics of surface ozone (O3) in this industrial area through the on-site measurement campaign during the July-August of 2010 and 2011, and to reveal the response of local O3 to its precursors' emissions through the NCAR-Master Mechanism model (NCAR-MM) simulation. Measurement results showed that the O3 concentration in this industrial area was significantly higher, with the mean daily average of 124.6 μg/m(3) and mean daily maximum of 236.8 μg/m(3), which are, respectively, 90.9 and 50.6 % higher than those in Beijing urban area. Moreover, the diurnal O3 peak generally started up early in 11:00-12:00 and usually remained for 5-6 h, greatly different with the normal diurnal pattern of urban O3. Then, we used NCAR-MM to simulate the average diurnal variation of photochemical O3 in sunny days of August 2010 in both industrial and urban areas. A good agreement in O3 diurnal variation pattern and in O3 relative level was obtained for both areas. For example of O3 daily maximum, the calculated value in the industrial area was about 51 % higher than in the urban area, while measured value in the industrial area was approximately 60 % higher than in the urban area. Finally, the sensitivity analysis of photochemical O3 to its precursors was conducted based on a set of VOCs/NOx emissions cases. Simulation results implied that in the industrial area, the response of O3 to VOCs was negative and to NOx was positive under the current conditions, with the sensitivity coefficients of -0.16~-0.43 and +0.04~+0.06, respectively. By contrast, the urban area was within the VOCs-limitation regime, where ozone enhancement in response to increasing VOCs emissions and to decreasing NOx emission. So, we think that the VOCs emissions control for this petrochemical industrial complex will increase the potential risk of local ozone pollution aggravation, but will be helpful to inhibit the

  3. The influence of biogenic emissions from Africa on tropical tropospheric ozone during 2006: a global modeling study

    Directory of Open Access Journals (Sweden)

    J. E. Williams

    2009-08-01

    Full Text Available We have performed simulations using a 3-D global chemistry-transport model to investigate the influence that biogenic emissions from the African continent exert on the composition of the troposphere in the tropical region. For this purpose we have applied two recently developed biogenic emission inventories provided for use in large-scale global models (Granier et al., 2005; Lathière et al., 2006 whose seasonality and temporal distribution for biogenic emissions of isoprene, other volatile organic compounds and NO is markedly different. The use of the 12 year average values for biogenic emissions provided by Lathière et al. (2006 results in an increase in the amount of nitrogen sequestrated into longer lived reservoir compounds which contributes to the reduction in the tropospheric ozone burden in the tropics. The associated re-partitioning of nitrogen between PAN, HNO3 and organic nitrates also results in a ~5% increase in the loss of nitrogen by wet deposition. At a global scale there is a reduction in the oxidizing capacity of the model atmosphere which increases the atmospheric lifetimes of CH4 and CO by ~1.5% and ~4%, respectively. Comparisons against a range of different measurements indicate that applying the 12 year average of Lathière et al. (2006 improves the performance of TM4_AMMA for 2006 in the tropics. By the use of sensitivity studies we show that the release of NO from soils in Africa accounts for between ~2–45% of tropospheric ozone in the African troposphere, ~10% in the upper troposphere and between ~5–20% of the tropical tropospheric ozone column over the tropical Atlantic Ocean. The subsequent reduction in OH over the source regions allows enhanced transport of CO out of the region. For biogenic volatile organic C1 to C3 species released from Africa, the effects on tropical tropospheric ozone are rather limited, although this source contributes to the global burden of VOC by between ~2–4% and

  4. Infrared matrix isolation and theoretical study of the initial intermediates in the reaction of ozone with cis-2-butene.

    Science.gov (United States)

    Clay, Mary; Ault, Bruce S

    2010-03-04

    Matrix isolation studies combined with infrared spectroscopy of the twin jet codeposition of ozone and cis-2-butene into argon matrices have led to the first observation of several early intermediates in this ozonolysis reaction. Specifically, evidence is presented for the formation and identification of the long sought-after Criegee intermediate, as well as confirming evidence for earlier reports of the primary and secondary ozonides. These species were observed after initial twin jet deposition, and grew upon annealing to 35 K. Extensive isotopic labeling ((18)O and (16,18)O mixtures) experiments provided important supporting data. Detailed theoretical calculations at the B3LYP/6-311++G(d,2p) level were carried out as well to augment the experimental work. Merged jet (flow reactor) experiments followed by cryogenic trapping in solid argon led to the formation of "late", stable oxidation products. Photochemical reactions of ozone with cis-2-butene was studied as well, as was the photochemical behavior of the primary and secondary ozonides.

  5. Extreme events in total ozone over the northern mid-latitudes: A case study based on long-term data sets from 5 ground-based stations

    Science.gov (United States)

    Rieder, Harald E.; Jancso, Leonhardt M.; Staehelin, Johannes; Maeder, Jörg A.; Ribatet, Mathieu; Peter, Thomas; Davison, Anthony C.

    2010-05-01

    In this study we analyze the frequency distribution of extreme events in low and high total ozone (termed ELOs and EHOs) for 5 long-term stations in the northern mid-latitudes in Europe (Belsk, Poland; Hradec Kralove, Czech Republic; Hohenpeissenberg and Potsdam, Germany; and Uccle, Belgium). Further, the influence of these extreme events on annual and seasonal mean values and trends is analysed. The applied method follows the new "ozone extreme concept", which is based on tools from extreme value theory [Coles, 2001; Ribatet, 2007], recently developed by Rieder et al. [2010a, b]. Mathematically seen the decisive feature within the extreme concept is the Generalized Pareto Distribution (GPD). In this analysis, the long-term trends needed to be removed first, differently to the treatment of Rieder et al. [2010a, b], in which the time series of Arosa was analysed, covering many decades of measurements in the anthropogenically undisturbed stratosphere. In contrast to previous studies only focusing on so called ozone mini-holes and mini-highs the "ozone extreme concept" provides a statistical description of the tails in total ozone distributions (i.e. extreme low and high values). It is shown that this concept is not only an appropriate method to describe the frequency and distribution of extreme events, it also provides new information on time series properties and internal variability. Furthermore it allows detection of fingerprints of physical (e.g. El Niño, NAO) and chemical (e.g. polar vortex ozone loss) features in the Earth's atmosphere as well as major volcanic eruptions (e.g. El Chichón, Mt. Pinatubo). It is shown that mean values and trends in total ozone are strongly influenced by extreme events. Trend calculations (for the period 1970-1990) are performed for the entire as well as the extremes-removed time series. The results after excluding extremes show that annual trends are most reduced at Hradec Kralove (about a factor of 3), followed by Potsdam

  6. STUDY ON THE STERILIZATION EFFECTS OF FUNGI BY THE TREATMENT OF OZONE%臭氧对真菌杀灭作用的初步研究

    Institute of Scientific and Technical Information of China (English)

    孙东平; 卢平; 张爱娟; 方志杰; 李红召

    2001-01-01

    以根霉,黑曲霉,青霉,酵母菌等为研究对象,测定了放电时间与致死率的曲线关系,并观察了与空白对照后其菌落形态的变化。实验结果表明,随着放电时间的增长,致死率明显升高,且能够达到完全杀菌。%In this paper, the lethal effect on Rhizopus, Aspergillus niger, Penicillium by ozone was studied. The mortality rate against the time of the treatment of ozone and the variation of ozone concentration was measured. The changes of cell form were also observed. The Experiment results indicate that fungi could be destroyed completely by ozone and the mortality rate obviously increase with the prolonging of treatment time. When ozone was absorbed by KI,the mortality rate declines.

  7. Influence of corona discharge on the ozone budget in the tropical free troposphere: a case study of deep convection during GABRIEL

    Science.gov (United States)

    Bozem, H.; Fischer, H.; Gurk, C.; Schiller, C. L.; Parchatka, U.; Koenigstedt, R.; Stickler, A.; Martinez, M.; Harder, H.; Kubistin, D.; Williams, J.; Eerdekens, G.; Lelieveld, J.

    2014-09-01

    Convective redistribution of ozone and its precursors between the boundary layer (BL) and the free troposphere (FT) influences photochemistry, in particular in the middle and upper troposphere (UT). We present a case study of convective transport during the GABRIEL campaign over the tropical rain forest in Suriname in October 2005. During one measurement flight the inflow and outflow regions of a cumulonimbus cloud (Cb) have been characterized. We identified a distinct layer between 9 and 11 km altitude with enhanced mixing ratios of CO, O3, HOx, acetone and acetonitrile. The elevated O3 contradicts the expectation that convective transport brings low-ozone air from the boundary layer to the outflow region. Entrainment of ozone-rich air is estimated to account for 62% (range: 33-91%) of the observed O3. Ozone is enhanced by only 5-6% by photochemical production in the outflow due to enhanced NO from lightning, based on model calculations using observations including the first reported HOx measurements over the tropical rainforest. The "excess" ozone in the outflow is most probably due to direct production by corona discharge associated with lightning. We deduce a production rate of 5.12 × 1028 molecules O3 flash-1 (range: 9.89 × 1026-9.82 × 1028 molecules O3 flash-1), which is at the upper limit of the range reported previously.

  8. Capacity building for freshwater insect studies in northern Patagonia, Argentina: DARWIN Initiative programme Biodiversidad de insectos acuáticos en Patagonia Norte, Argentina: programa Iniciativa DARWIN

    Directory of Open Access Journals (Sweden)

    Stephen J. Brooks

    2009-06-01

    Full Text Available This project was funded from September 2006 for three years by the British Government's Darwin Initiative programme. The focus of our project is the study of aquatic insects from Nahuel Huapi National Park (NHNP in Patagonia, Argentina. The park includes a wide range of wetlands, including montane streams, lowland lakes and marshes, distributed within temperate rainforest and arid steppe. The material will be identified and stored in a fully referenced and accessible collection at La Plata Museum and the Natural History Museum, London. Darwin Initiative funding has been used to equip a biodiversity laboratory at National Park Headquarters in Bariloche and also a field station at Puerto Blest. Information on the insect species in NHNP will be entered into a GIS database, together with a vegetation classification and wetland characteristics, to model freshwater insect data spatially and create a biodiversity database, the first of its kind in Patagonia. We hope that the experiences we gain during the project, the insect collections and databases, the publications, and the many other products, will be used to further enhance wetland conservation throughout Argentina and southern South America.Este proyecto fue financiado durante un período de tres años, desde septiembre de 2006 a través de la Iniciativa Darwin del gobierno Británico. El objetivo de este trabajo es el estudio de los insectos acuáticos del Parque Nacional Nahuel Huapi (PNNHP, Patagonia, Argentina. El parque incluye una gran variedad de hábitats que comprenden arroyos, ríos y lagos los cuales se distribuyen desde el bosque siempreverde frío, hasta la zona árida de estepa. Todo el material será identificado y depositado en las colecciones del Museo La Plata y el Museo de Historia Natural de Londres. Los fondos de la Iniciativa Darwin han sido utilizados para equipar un laboratorio de biodiversidad en las oficinas del PNNHP en Bariloche y la estación de investigación en

  9. An investigation of high ozone episodes in the City of Johannesburg

    CSIR Research Space (South Africa)

    Padayachi, YR

    2014-10-01

    Full Text Available A study of ozone monitoring data in Johannesburg highlighted that the city is frequently affected by high ozone episodes. There is limited knowledge about the chemical and meteorological drivers of these high ozone episodes in Johannesburg...

  10. Importance of Ship Emissions to Local Summertime Ozone Production in the Mediterranean Marine Boundary Layer: A Modeling Study

    OpenAIRE

    Gencarelli, Christian N.; Ian M. Hedgecock; Francesca Sprovieri; Schürmann, Gregor J.; Nicola Pirrone

    2014-01-01

    Ozone concentrations in the Mediterranean area regularly exceed the maximum levels set by the EU Air Quality Directive, 2008/50/CE, a maximum 8-h mean of 120 μg·m-3, in the summer, with consequences for both human health and agriculture. There are a number of reasons for this: the particular geographical and meteorological conditions in the Mediterranean play a part, as do anthropogenic ozone precursor emissions from around the Mediterranean and continental Europe. Ozone concentrations measur...

  11. Establishment of a structural equation model for ground-level ozone: a case study at an urban roadside site.

    Science.gov (United States)

    Lin, Kun-Ming; Yu, Tai-Yi; Chang, Len-Fu

    2014-12-01

    This study established a cause-effect relationship between ground-level ozone and latent variables employing partial least-squares analysis at an urban roadside site in four distinct seasons. Two multivariate analytic methods, factor analysis, and cluster analysis were adopted to cite and identify suitable latent variables from 14 observed variables (i.e., meteorological factors, wind and primary air pollutants) in 2008-2010. Analytical results showed that the first six components explained 80.3 % of the variance, and eigenvalues of the first four components were greater than 1. The effectiveness of this model was empirically confirmed with three indicators. Except for surface pressure, factor loadings of observed variables were 0.303-0.910 and reached statistical significance at the 5 % level. Composite reliabilities for latent variables were 0.672-0.812 and average variances were 0.404-0.547, except for latent variable "primary" in spring; thus, discriminant validity and convergent validity were marginally accepted. The developed model is suitable for the assessment of urban roadside surface ozone, considering interactions among meteorological factors, wind factors, and primary air pollutants in each season.

  12. Photodegradation of secondary organic aerosol generated from limonene oxidation by ozone studied with chemical ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    X. Pan

    2009-02-01

    Full Text Available Photodegradation of secondary organic aerosol (SOA prepared by ozone-initiated oxidation of D-limonene is studied with an action spectroscopy approach, which relies on detection of volatile photoproducts with chemical ionization mass-spectrometry as a function of the UV irradiation wavelength. Efficient photodegradation is observed for a broad range of ozone and D-limonene concentrations (0.1–300 ppm used in the preparation of SOA. The observed photoproducts are dominated by oxygenated C1-C3 compounds such as methanol, formic acid, acetaldehyde, acetic acid, and acetone. The irradiation wavelength dependence of the combined yield of the photoproducts closely tracks the absorption spectrum of the SOA material suggesting that photodegradation is not limited to the UV wavelengths. Kinetic simulations suggest that RO2+HO2/RO2 reactions represent the dominant route to photochemically active carbonyl and peroxide species in the limonene SOA material. Similar photodegradation processes are likely to occur in realistic SOA produced by OH- or O3-initiated oxidation of biogenic volatile organic compounds in clean air.

  13. Photodegradation of secondary organic aerosol generated from limonene oxidation by ozone studied with chemical ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    X. Pan

    2009-06-01

    Full Text Available Photodegradation of secondary organic aerosol (SOA prepared by ozone-initiated oxidation of D-limonene is studied with an action spectroscopy approach, which relies on detection of volatile photoproducts with chemical ionization mass-spectrometry as a function of the UV irradiation wavelength. Efficient photodegradation is observed for a broad range of ozone (0.1–300 ppm and D-limonene (0.02–3 ppm concentrations used in the preparation of SOA. The observed photoproducts are dominated by oxygenated C1-C3 compounds such as methanol, formic acid, acetaldehyde, acetic acid, and acetone. The irradiation wavelength dependence of the combined yield of the photoproducts closely tracks the absorption spectrum of the SOA material suggesting that photodegradation is not limited to the UV wavelengths. Kinetic simulations suggest that RO2+HO2/RO2 reactions represent the dominant route to photochemically active carbonyl and peroxide species in the limonene SOA prepared in these experiments. Similar photodegradation processes are likely to occur in realistic SOA produced by OH- or O3-initiated oxidation of biogenic volatile organic compounds in clean air.

  14. [Modeling Study of A Typical Summer Ozone Pollution Event over Yangtze River Delta].

    Science.gov (United States)

    Zhang, Liang; Zhu, Bin; Gao, Jin-hui; Kang, Han-qing; Yang, Peng; Wang, Hong-lei; Li, Yue-e; Shao, Ping

    2015-11-01

    WRF/Chem model was used to analyze the temporal and spatial distribution characteristics and physical and chemical mechanism of a typical summer ozone pollution event over Yangtze River Delta (YRD). The result showed that the model was capable of reproducing the temporal and spatial distribution and evolution characteristics of the typical summer ozone pollution event over YRD. The YRD region was mainly affected by the subtropical high-pressure control, and the weather conditions of sunshine, high temperature and small wind were favorable for the formation of photochemical pollution on August 10-18, 2013. The results of simulation showed that the spatial and temporal distribution of O3 was obviously affected by the meteorological fields, geographic location, regional transport and chemical formation over YRD. The sensitivity experiment showed that the O3 concentration affected by maritime airstream was low in Shanghai, but the impact of Shanghai emissions on the spatial and temporal distribution of O3 concentration over YRD was significant; The main contribution of the high concentration of O3 in Nanjing surface was chemical generation ( alkene and aromatic) and the vertical transport from high-altitude O3, whereas the main contribution of the high concentration of O3 in Hangzhou and Suzhou was physics process. The influence of the 15:00 peak concentration of O3 over YRD was very obvious when O3 precursor was reduced at the maximum O3 formation rate (11-13 h).

  15. Diurnal variation of surface ozone in mountainous areas: Case study of Mt. Huang, East China.

    Science.gov (United States)

    Zhang, Lei; Jin, Lianji; Zhao, Tianliang; Yin, Yan; Zhu, Bin; Shan, Yunpeng; Guo, Xiaomei; Tan, Chenghao; Gao, Jinhui; Wang, Haoliang

    2015-12-15

    To explore the variations in atmospheric environment over mountainous areas, measurements were made from an intensive field observation at the summit of Mt. Huang (30.13°N, 118.15°E, 1841m above sea level), a rural site located in East China, from June to August 2011. The measurements revealed a diurnal change of surface O3 with low concentrations during the daytime and high concentrations during the nighttime. The causes of diurnal O3 variations over the mountain peak in East China were investigated by using a fairly comprehensive WRF-Chem and HYSPLIT4 modeling approach with observational analysis. By varying model inputs and comparing the results to a baseline modeling and actual air quality observations, it is found that nearby ozone urban/anthropogenic emission sources were contributing to a nighttime increase in mountaintop ozone levels due to a regional transport lag and residual layer effects. Positive correlation of measured O3 and CO concentrations suggested that O3 was associated with anthropogenic emissions. Sensitivity modeling experiments indicated that local anthropogenic emissions had little impact on the diurnal pattern of O3. The diurnal pattern of O3 was mainly influenced by regional O3 transport from the surrounding urban areas located 100-150km away from the summit, with a lag time of 10h for transport.

  16. Ozone Treatment For Cooling Towers

    Science.gov (United States)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  17. Ozone therapy: A clinical review

    OpenAIRE

    Elvis, A. M.; Ekta, J. S.

    2011-01-01

    Ozone (O3) gas discovered in the mid-nineteenth century is a molecule consisting of three atoms of oxygen in a dynamically unstable structure due to the presence of mesomeric states. Although O3 has dangerous effects, yet researchers believe it has many therapeutic effects. Ozone therapy has been utilized and heavily studied for more than a century. Its effects are proven, consistent, safe and with minimal and preventable side effects. Medical O3 is used to disinfect and treat disease. Mechan...

  18. Risk assessment of ozone effects with special consideration to epidemiological studies; Risikoabschaetzung der Ozonwirkung unter besonderer Beruecksichtigung epidemiologischer Studien

    Energy Technology Data Exchange (ETDEWEB)

    Hoeppe, P. [Muenchen Univ. (Germany). Inst. fuer Arbeits- und Umweltmedizin; Wagner, M.

    2000-07-01

    Ozone in environmental concentrations can irritate mucous membranes of the respiratory tract, lead to decrements of lung function and cause inflammatory processes in airways and lung. These functional changes in general are not perceived subjectively. Approximately 10-20% of the population respond more sensitively towards ozone. After repeated exposure to elevated ozone concentrations e.g. during persistent high pressure situations in summer ozone effects can still be found several days after the end of exposure. Indications of potential chronic ozone effects (cancerogenity, fibrosis of lung tissue or induction of asthma) are weak even in areas with the highest ozone concentrations and need verification. The same is valid for the potential influence of ozone on mortality. (orig.) [German] Umweltepidemiologische Studien haben gezeigt, dass Ozon in umweltrelevanten Konzentrationen zu Reizungen der Schleimhaeute der oberen Atemwege, zur Beeintraechtigung der Lungenfunktion und zu entzuendlichen Prozessen in den Atemwegen und der Lunge fuehren kann. Die funktionalen Beeintraechtigungen sind subjektiv meist nicht wahrnehmbar. Ca. 10-20% der Bevoelkerung reagieren besonders empfindlich auf Ozon. Nach wiederholten hohen Ozonexpositionen z.B. waehrend anhaltender sommerlicher Schoenwetterperioden koennen Ozonwirkungen noch bis einige Tage nach Beendigung der Belastung nachgewiesen werden. Hinweise auf potentielle chronische Ozonwirkungen (Kanzerogenitaet, Verhaertungen des Lungengewebes oder Induzierung von Asthma) sind selbst in den am staerksten ozonbelasteten Regionen wie z.B. in Kalifornien nur sehr schwach und beduerfen weiterer wissenschaftlicher Abklaerung; dasselbe gilt fuer einen moeglichen Einfluss auf die Mortalitaet. (orig.)

  19. The use of ozonated water and 0.2% chlorhexidine in the treatment of periodontitis patients: A clinical and microbiologic study

    Directory of Open Access Journals (Sweden)

    Kshitish Durga

    2010-01-01

    Full Text Available Background: The development of periodontal disease has been thought to be associated with several restricted members of the oral anaerobic species, such as black-pigmented Porphyromonas species and Actinobacillus actinomycetemcomitans (Aa, in the subgingival environment. Apart from bacteria, certain viruses and fungi that are associated with periodontal disease are also present in the subgingival plaque . Materials and Methods: A randomized, double-blind, crossover split-mouth design was performed. A total of 16 patients suffering from generalized chronic periodontitis were selected for the study. The study period of 18 days was divided into two time-intervals, i.e. baseline (0 days to 7 th day, with a washout period of 4 days followed by a second time interval of 7 days. The use of ozone and chlorhexidine gluconate (CHX irrigation was randomized. Both the patient and the clinician evaluating the clinical parameters were blinded regarding the type of irrigation used. Results: The interpretation of clinical and microbial data is from baseline to 7 th day. A higher percentage of plaque index (12%, gingival index (29% and bleeding index (26% reduction was observed using ozone irrigation as compared to chlorhexidine. The percentile reduction of Aa (25% using ozone was appreciable as compared to no change in Aa occurrence using chlorhexidine. By using O 3 and chlorhexidine, there was no antibacterial effect on Porphyromonas gingivalis (Pg and Tannerella forsythensis. The antifungal effect of ozone from baseline (37% to 7 th day (12.5% was pronounced during the study period, unlike CHX, which did not demonstrate any antifungal effect. Conclusion: Ozone may be considered as an alternative management strategy due to its powerful ability to inactivate microorganisms. Also, there is growing evidence that ozone can be employed as a useful therapeutic agent in both dentistry and medicine.

  20. Evaluation of Performance Catalytic Ozonation with Activated Alumina in the Removal of Pentachlorophenol from Aqueous Solutions and Study of the Intermediates

    Directory of Open Access Journals (Sweden)

    A.R. Rahmani

    2013-04-01

    Full Text Available Introduction & Objective: Pentachlorophenol (PCP is a refractory phenolic compound. Owing to its high poisonous and carcinogenic nature, PCP is on the US EPA’s list of priority pollut-ants. As a result, it is one of the important pollutants that need to be removed during water and wastewater reclamation processes. The efficiency of the catalytic ozonation process (COP was assessed based on the removal of PCP from the aqueous solutions and its inter-mediates were studied. Materials & Methods: In this experimental study, catalytic ozonation process was applied to remove PCP in aqueous solution and its intermediate was studied. The influence of several variables was examined, including pH of solution, contact time, dissolved ozone concentra-tion and dosage of -Al2O3 in semi batch reactor. The determination of PCP concentrations in solutions was analyzed by HPLC using the UV detector (254nm. Results: Our results showed that the removal effectiveness of PCP has been increased by ris-ing pH, contact time, catalyst dosage and dissolved ozone concentration. Removal efficiency of PCP was determined 89% and 100% in SOP and AOP after 60 minutes, respectively. The pHzpc of alumina was determined 8.6. Conclusion: Due to high performance of -Al2O3 as catalyst in catalytic ozonation and increas-ing the PCP removal, it is thus concluded that the integrated catalytic ozonation is a promis-ing and economically affordable technology for the treatment of wastewater containing pen-tachlorophenol and other similar compounds. (Sci J Hamadan Univ Med Sci 2013; 20 (1:77-85

  1. Ozonized oils: a qualitative and quantitative analysis.

    Science.gov (United States)

    Guinesi, Adriana Simionatto; Andolfatto, Carolina; Bonetti Filho, Idomeo; Cardoso, Arnaldo Alves; Passaretti Filho, Juliano; Farac, Roberta Vieira

    2011-01-01

    Most of the problems of endodontic origin have a bacterial etiological agent. Thus, there is a continued interest in seeking more effective chemical substances that can replace the camphorated paramonochiorophenol or antibiotics as intracanal medicaments. Among the possible substances, ozone has some interesting biological characteristics: bactericidal action, debriding effect, angiogenesis stimulation capacity and high oxidizing power. The purpose of this study was to chemically evaluate the presence of ozone in sunflower, castor, olive and almond oil, as well as in propylene glycol and byproducts of ozonation, such as formaldehyde. These compounds were ozonized, inserted into empty and sterile vials, and analyzed by testing the reaction between ozone and indigo, for determining the presence of ozone, and subjected to the chromotropic acid test for determining the presence of formaldehyde. It was observed complete absence of ozone in all samples tested and presence of formaldehyde. The bactericidal and healing action of ozonized oils could be attributed to products formed by the ozonation of mineral oils, such as formaldehyde, not to the ozone itself.

  2. Ozone kinetics in low-pressure discharges

    Science.gov (United States)

    Guerra, Vasco; Marinov, Daniil; Guaitella, Olivier; Rousseau, Antoine

    2012-10-01

    Ozone kinetics is quite well established at atmospheric pressure, due to the importance of ozone in atmospheric chemistry and to the development of industrial ozone reactors. However, as the pressure is decreased and the dominant three-body reactions lose importance, the main mechanisms involved in the creation and destruction of ozone are still surrounded by important uncertainties. In this work we develop a self-consistent model for a pulsed discharge and its afterglow operating in a Pyrex reactor with inner radius 1 cm, at pressures in the range 1-5 Torr and discharge currents of 40-120 mA. The model couples the electron Boltzmann equation with a system of equations for the time evolution of the heavy particles. The calculations are compared with time-dependent measurements of ozone and atomic oxygen. Parametric studies are performed in order to clarify the role of vibrationally excited ozone in the overall kinetics and to establish the conditions where ozone production on the surface may become important. It is shown that vibrationally excited ozone does play a significant role, by increasing the time constants of ozone formation. Moreover, an upper limit for the ozone formation at the wall in these conditions is set at 10(-4).

  3. Comparative experimental study on municipal wastewater disinfection with ozone and peracetic acid; Indagine sperimentale comparata sulla disinfezione di acque reflue urbane con ozono e acido peracetico

    Energy Technology Data Exchange (ETDEWEB)

    Andreottola, G.; Bertola, P.; Ziglio, G. [Trento Univ. (Italy). Dip. di Ingegneria Civile Ambientale

    1996-04-01

    The results of a pilot experimental study on the disinfection of treated municipal wastewater to be used in agriculture are presented. A comparative evaluation has been carried out on two parallel pilot-scale disinfection plants using respectively ozone and peracetic acid. After a preliminary sand filtration pilot unit. Both processes showed the capability of meeting the Italian standards for agricultural reuse, but the disinfection process with ozone required much higher doses than the one with peracetic acid, probably because of the higher reactivity of ozone, if compared to peracetic acid with the organic matter present in wastewater. Further research is needed in order to evaluate the efficiency of peracetic acid applied to microorganism different from the bacterial ones and to identify nature and consequences of possible disinfection by products.

  4. A model study on changes of European and Swiss particulate matter, ozone and nitrogen deposition between 1990 and 2020 due to the revised Gothenburg protocol

    Science.gov (United States)

    Aksoyoglu, S.; Keller, J.; Ciarelli, G.; Prévôt, A. S. H.; Baltensperger, U.

    2014-12-01

    We report a study of changes in air quality due to emission reductions using the chemical transport model CAMx. The model domain includes all of Europe with a nested domain over Switzerland. The model simulations were performed with emissions for 1990 (the reference year for the Gothenburg Protocol), 2005 (the reference year for the revised Gothenburg Protocol), 2006 (for model validation) and 2020 (the target year for the revised Gothenburg Protocol) using three emission scenarios prepared by IIASA/GAINS. Changes in ozone, particulate matter and nitrogen deposition are the central theme of the study. The modelled relative changes in the annual average PM2.5 concentrations between 1990 and 2005 look reasonable based on various PM10 and PM2.5 observations in the past. The results obtained in this study suggest that annual mean concentrations of PM2.5 decreased by about 20-50% in Europe. Simulations using the baseline scenario (BL 2020) suggest that PM2.5 concentrations in 2020 will be about 30% lower than those in 2005. The largest predicted decrease in PM2.5, based on the MTFR (maximum technically feasible reduction) scenario, was about 60% and was located mainly in the eastern part of Europe. In the case of ozone, both model results and measurements show an increase in the mean ozone mixing ratios between 1990 and 2005. The observations, however, suggest a larger increase, indicating the importance of background ozone levels. Although emission reductions caused a decrease in peak ozone values, average ozone levels in polluted regions increased due to reduced titration with nitric oxide (NO). This caused a change in the frequency distribution of ozone. Model simulations using emission scenarios for 2020 suggest that annual average ozone mixing ratios will continue to increase. Changes in the levels of the damage indicators AOT40 for forests and SOMO35 are reported as well. The model results suggest that nitrogen deposition has decreased by 10-30% in the eastern

  5. Neritic Jellyfishes (Cnidaria: Cubozoa and Scyphozoa from the coast of Rio Grande do Norte state, northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Matthews-Cascon, H.

    2009-01-01

    Full Text Available For the entire Brazilian coast, there are 22 published records of scyphozoans. On the other hand, only 35 species ofcubozoans were described worldwide, four of them reported for the Brazilian coast. However, little is known about thespecies of cubozoans and scyphozoans in the Northeastern states of Brazil. The aim of this study was to perform asurvey of the jellyfish (Cnidaria: Cubozoa and Scyphozoa on the coast of Rio Grande do Norte state, Northeast ofBrazil. Specimens were collected using trawl net on beaches in the counties of Natal (in 2003 and Tibaú (in 2004. Forthe Rio Grande do Norte coast there were few records of large jellyfish, and new records of the following cubozoan andscyphozoan species were verified: Chiropsalmus quadrumanus; Chrysaora lactea; Lychnorhiza lucerna andStomolophus meleagris. The studied species had their distributions expanded in the coast to the State of Rio Grande doNorte.

  6. Theoretical Studies of the HO/HO2 Catalytic Cycle for Ozone Destruction

    Science.gov (United States)

    Walch, Stephen P.; Langhoff, Steve R. (Technical Monitor)

    1996-01-01

    Recently it has been determined that the HO/HO2 catalytic cycle accounts for nearly one-half of the total ozone depletion in the lower stratosphere. The catalytic cycle is: (1) HO + O3 yields HO2 + O2; (2) HO2 + O3 yields HO + O2 + O2. The net reaction is 2O3 yields 3O2. The rate limiting step in this process is the reaction of HO2 with ozone. There is a problem extending the experimental measurement of the rate of this reaction over the range 233-400 K down to stratospheric temperatures of 210-220 K. Therefore we have undertaken a project to determine the temperature dependence of the rate constant for this reaction in the low temperature region. The first step in this project, which is described in this poster, is the determination of the relevant potential energy surfaces. The calculations use CASSCF/derivative methods to define the pathways followed by CASSCF/ACPF to determine the energetics. The HO + O3 reaction is found to proceed through an HO4 complex, which is unstable with respect to HO2 + O2. The HO2 +O3 reaction is more complex. One pathway, which has been characterized, is the formation of an HO5 complex which decomposes to HO3 + O2 and subsequently to HO + O2 + O2. Another pathway, which is believed to also play a role, is hydrogen abstraction to give O2 + HO3 and subsequent decomposition of HO3 to HO + O2. Isotopic labeling experiments indicate that the later pathway is dominant. However, so far attempts to locate the saddle point for this pathway have not been successful. We have also characterized the potential energy surfaces for a number of species involved in these reactions, including HO3 and triplet O4. The triplet O4 species is probably involved in the reaction of vibrationally excited O2 with ground state O2 leading to O3 + O. The latter reaction is believed to be important as an additional source of stratospheric ozone.

  7. A model study on changes of European and Swiss particulate matter, ozone and nitrogen deposition between 1990 and 2020 due to the revised Gothenburg protocol

    Directory of Open Access Journals (Sweden)

    S. Aksoyoglu

    2014-06-01

    Full Text Available We report a study of changes in air quality due to emission reductions using the chemical transport model CAMx. The model domain includes all of Europe with a nested domain over Switzerland. The model simulations were performed for 1990 (the reference year for the Gothenburg Protocol, 2005 (the reference year for the revised Gothenburg Protocol, 2006 (for model validation and 2020 (the target year for the revised Gothenburg Protocol using three emission scenarios prepared by IIASA/GAINS. Changes in ozone, particulate matter and nitrogen deposition are the central theme of the study. The relative changes in the annual average PM2.5 concentrations between 1990 and 2005 were reproduced very well. Both model results and observations show that annual mean concentrations of PM2.5 decreased by about 20–50% in Europe. Simulations using the baseline scenario (BL 2020 suggest that PM2.5 concentrations in 2020 will be about 30% lower than those in 2005. The largest predicted decrease in PM2.5, based on the MTFR (Maximum Technically Feasible Reduction scenario, was about 60% and was located mainly in the eastern part of Europe. In the case of ozone, both model results and measurements show an increase in the mean ozone mixing ratios between 1990 and 2005. The observations, however, suggest a larger increase, indicating the importance of background ozone levels. Although emission reductions caused a decrease in peak ozone values, ozone levels in polluted regions increased due to reduced titration with nitric oxide (NO. This caused a change in the frequency distribution of ozone. Model simulations using emission scenarios for 2020 suggest that annual average ozone mixing ratios will continue to increase. Changes in the levels of the damage indicators AOT40 for forests and SOMO35 are reported as well. The model results suggest that nitrogen deposition decreased by 10–30% in the eastern part of Europe since 1990, while it increased by about 20% in the

  8. Prevention of Mold Contamination : Ozone Treatment

    OpenAIRE

    Nakarmi, Kanchan

    2016-01-01

    Mold is a common pest that can cause diseases and decay property. Moreover, certain mold can produce toxic chemicals which leads directly or indirectly to additional health impacts and economic losses. Therefore, prevention of mold growth is a major concern, and disinfection of mold has become a center of attention. The purpose of this thesis was to study about the effect of ozone in the disinfection of mold and the method of producing ozone. The usage of ozone for disinfection in in...

  9. A theoretical model of atmospheric ozone depletion

    Science.gov (United States)

    Midya, S. K.; Jana, P. K.; Lahiri, T.

    1994-01-01

    A critical study on different ozone depletion and formation processes has been made and following important results are obtained: (i) From analysis it is shown that O3 concentration will decrease very minutely with time for normal atmosphere when [O], [O2] and UV-radiation remain constant. (ii) An empirical equation is established theoretically between the variation of ozone concentration and time. (iii) Special ozone depletion processes are responsible for the dramatic decrease of O3-concentration at Antarctica.

  10. Activity of ozonated water and ozone against Staphylococcus aureus and Pseudomonas aeruginosa biofilms

    Science.gov (United States)

    Bialoszewski, Dariusz; Pietruczuk-Padzik, Anna; Kalicinska, Agnieszka; Bocian, Ewa; Czajkowska, Magdalena; Bukowska, Bozena; Tyski, Stefan

    2011-01-01

    Summary Background The known bactericidal properties of ozone have not been checked in relation to its action on bacterial biofilms. This is especially true of ozonated fluids. The aim of this study was to investigate the bactericidal activity of ozonated water and that of a mixture of ozone and oxygen against biofilms. Material/Methods Eighteen clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa exhibiting various levels of antibiotic sensitivity were investigated. Bacteria were cultured in biofilm form on polystyrene titration plates for periods of 2 to 72 hours. The biofilms formed in this way were exposed to in statu nascendi ozonated water produced in a prototype device that had been tested in clinical conditions, or to a mixture of oxygen and ozone generated in the same device. Live cells in the biofilm were stained with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide solution. The degree of reduction of viable bacteria following ozone exposure was determined. Results Ozonated water was found to be an effective bactericidal agent against biofilms after as little as 30 seconds of exposure, while the bactericidal activity of the ozone-oxygen solution was much lower. Prolongation of the duration of biofilm exposure to the gaseous disinfectant to 40 minutes led to a reduction in the viable cell count, which nevertheless remained high. Conclusions Unlike the ozone-oxygen mixture, ozonated water effectively destroys bacterial biofilms in vitro. PMID:22037737

  11. Kinetic study of the degradation of C5 and C6 unsaturated aldehydes and alcohols by ozone

    Science.gov (United States)

    Kalalian, Carmen; Roth, Estelle; Chakir, Abdelkhaleq

    2017-04-01

    Emissions of biogenic volatile organic compounds (VOCs) are higher than those from anthropogenic sources. They are therefore likely to have a great influence on atmospheric chemistry both locally and regionally, through their impact on the HOx balance (HOx = HO + HO2), ozone production and ability to form secondary organic aerosols (SOA). Among the volatile organic compounds of biogenic origin are the family of C5 and C6 unsaturated aldehydes and alcohols. Few information exist regarding the fate of these compounds in the atmosphere especially there reaction with ozone. In this work, we studied the kinetics of the reaction of three unsaturated aldehydes (trans-2-pentenal, trans-2-hexenal and 2-methyl-2-pentenal) and three unsaturated alcohols (1-penten-3-ol, cis-2-penten-1-ol and trans-3-hexen-1-ol) with ozone O3 in a rigid atmospheric simulation chamber coupled to an FTIR spectrometer at four different temperatures (273, 298, 333 and 353 K) and at atmospheric pressure. The rate constants of the ozonolysis reaction of the unsaturated aldehydes and the unsaturated alcohols studied were determined and the following Arrhenius expression was obtained (cm3 molecule -1 s -1): k (Trans -2-pentenal)= (3.83 ± 3.71) x 10-16 exp (- (1706 ± 295) / T) k (Trans-2-hexenal)= (1.43 ± 0.67) x 10-16 exp (- (1369 ± 141) / T) k(2-Methyl-2-pentenal)= (3.62± 0.22) x 10-18 exp (- (121 ± 20) / T) k(1-penten-3-ol) = (1.42 ± 1.24) x 10-16 exp (- (642 ± 250) / T) k(Cis-2-penten-1-ol)= (3.14 ± 0.45) x 10-15 exp (- (1045 ± 40) / T) k(Trans-3-hexen-1-ol)= (6.38 ± 1.75) x 10-16 exp (- (686 ± 89) / T) The obtained data will be discussed in terms of structure-reactivity relationship and compared with the reported reactivity with OH radicals. The atmospheric implications derived from this study are discussed as well.

  12. Effect of ozonation of swimming pool water on formation of volatile disinfection by-products - A laboratory study

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Cheema, Waqas Akram

    2016-01-01

    Ozonation experiments were performed using unchlorinated tap water used for filling municipal swimming pools, actual pool water and pool water polluted by addition of fresh tap water and artificial body fluid to evaluate ozone kinetics and water quality effects on formation of volatile disinfection...

  13. Corea del Norte: vientos favorables para el cambio

    National Research Council Canada - National Science Library

    Garcia, Pio

    2009-01-01

    Las manifestaciones de fuerza de Corea del Norte durante el ultimo ano crisparon los nervios de los televidentes de todo el mundo, ante el temor de un conflicto de grandes dimensiones en el noreste asiatico...

  14. Effects of ozone on functional properties of proteins.

    Science.gov (United States)

    Uzun, Hicran; Ibanoglu, Esra; Catal, Hatice; Ibanoglu, Senol

    2012-09-15

    The present study investigates whether the ozone treatment could be an alternative to improve some functional properties of proteins. Ozone treatment was applied on whey protein isolate and egg white proteins which have been extensively used in food products to improve textural, functional and sensory attributes. Ozone treatment of proteins was performed either in aqueous solutions or as gas ozonation of pure protein powders. Foam formation and foam stability of proteins were enhanced extensively. The solubility of proteins were reduced as influenced from the aqueous and gas ozonation medium. The reduction was more pronounced in egg white proteins. Ozone treatment affected emulsion activity of whey protein isolate negatively and reduced the emulsion stability.

  15. Two mechanisms of stratospheric ozone loss in the Northern Hemisphere, studied using data assimilation of Odin/SMR atmospheric observations

    Science.gov (United States)

    Sagi, Kazutoshi; Pérot, Kristell; Murtagh, Donal; Orsolini, Yvan

    2017-02-01

    Observations from the Odin/Sub-Millimetre Radiometer (SMR) instrument have been assimilated into the DIAMOND model (Dynamic Isentropic Assimilation Model for OdiN Data), in order to estimate the chemical ozone (O3) loss in the stratosphere. This data assimilation technique is described in Sagi and Murtagh (2016), in which it was used to study the inter-annual variability in ozone depletion during the entire Odin operational time and in both hemispheres. Our study focuses on the Arctic region, where two O3 destruction mechanisms play an important role, involving halogen and nitrogen chemical families (i.e. NOx = NO and NO2), respectively. The temporal evolution and geographical distribution of O3 loss in the low and middle stratosphere have been investigated between 2002 and 2013. For the first time, this has been done based on the study of a series of winter-spring seasons over more than a decade, spanning very different dynamical conditions. The chemical mechanisms involved in O3 depletion are very sensitive to thermal conditions and dynamical activity, which are extremely variable in the Arctic stratosphere. We have focused our analysis on particularly cold and warm winters, in order to study the influence this has on ozone loss. The winter 2010/11 is considered as an example for cold conditions. This case, which has been the subject of many studies, was characterised by a very stable vortex associated with particularly low temperatures, which led to an important halogen-induced O3 loss occurring inside the vortex in the lower stratosphere. We found a loss of 2.1 ppmv at an altitude of 450 K in the end of March 2011, which corresponds to the largest ozone depletion in the Northern Hemisphere observed during the last decade. This result is consistent with other studies. A similar situation was observed during the winters 2004/05 and 2007/08, although the amplitude of the O3 destruction was lower. To study the opposite situation, corresponding to a warm and

  16. Associations of ozone and PM2.5 concentrations with Parkinson’s disease among participants in the Agricultural Health Study

    Science.gov (United States)

    Background: Evidence from experimental studies suggests that exposure to air pollution may be associated with risk of Parkinson’s disease (PD). Objective: To evaluate associations of ambient ozone and fine particulate matter (PM2.5 – particulate matter with an aerodynamic diam...

  17. Numerical simulation for regional ozone concentrations: A case study by weather research and forecasting/chemistry (WRF/Chem) model

    Energy Technology Data Exchange (ETDEWEB)

    Habib Al Razi, Khandakar Md; Hiroshi, Moritomi [Environmental and Renewable Energy System, Graduate School of Engineering, Gifu University, 1-1 Yanagido, Gifu City, 501-1193 (Japan)

    2013-07-01

    The objective of this research is to better understand and predict the atmospheric concentration distribution of ozone and its precursor (in particular, within the Planetary Boundary Layer (Within 110 km to 12 km) over Kasaki City and the Greater Tokyo Area using fully coupled online WRF/Chem (Weather Research and Forecasting/Chemistry) model. In this research, a serious and continuous high ozone episode in the Greater Tokyo Area (GTA) during the summer of 14–18 August 2010 was investigated using the observation data. We analyzed the ozone and other trace gas concentrations, as well as the corresponding weather conditions in this high ozone episode by WRF/Chem model. The simulation results revealed that the analyzed episode was mainly caused by the impact of accumulation of pollution rich in ozone over the Greater Tokyo Area. WRF/Chem has shown relatively good performance in modeling of this continuous high ozone episode, the simulated and the observed concentrations of ozone, NOx and NO2 are basically in agreement at Kawasaki City, with best correlation coefficients of 0.87, 0.70 and 0.72 respectively. Moreover, the simulations of WRF/Chem with WRF preprocessing software (WPS) show a better agreement with meteorological observations such as surface winds and temperature profiles in the ground level of this area. As a result the surface ozone simulation performances have been enhanced in terms of the peak ozone and spatial patterns, whereas WRF/Chem has been succeeded to generate meteorological fields as well as ozone, NOx, NO2 and NO.

  18. Numerical simulation for regional ozone concentrations: A case study by weather research and forecasting/chemistry (WRF/Chem model

    Directory of Open Access Journals (Sweden)

    Khandakar Md Habib Al Razi, Moritomi Hiroshi

    2013-01-01

    Full Text Available The objective of this research is to better understand and predict the atmospheric concentration distribution of ozone and its precursor (in particular, within the Planetary Boundary Layer (Within 110 km to 12 km over Kasaki City and the Greater Tokyo Area using fully coupled online WRF/Chem (Weather Research and Forecasting/Chemistry model. In this research, a serious and continuous high ozone episode in the Greater Tokyo Area (GTA during the summer of 14–18 August 2010 was investigated using the observation data. We analyzed the ozone and other trace gas concentrations, as well as the corresponding weather conditions in this high ozone episode by WRF/Chem model. The simulation results revealed that the analyzed episode was mainly caused by the impact of accumulation of pollution rich in ozone over the Greater Tokyo Area. WRF/Chem has shown relatively good performance in modeling of this continuous high ozone episode, the simulated and the observed concentrations of ozone, NOx and NO2 are basically in agreement at Kawasaki City, with best correlation coefficients of 0.87, 0.70 and 0.72 respectively. Moreover, the simulations of WRF/Chem with WRF preprocessing software (WPS show a better agreement with meteorological observations such as surface winds and temperature profiles in the ground level of this area. As a result the surface ozone simulation performances have been enhanced in terms of the peak ozone and spatial patterns, whereas WRF/Chem has been succeeded to generate meteorological fields as well as ozone, NOx, NO2 and NO.

  19. Tropospheric ozone as a fungal elicitor

    Indian Academy of Sciences (India)

    Paolo Zuccarini

    2009-03-01

    Tropospheric ozone has been proven to trigger biochemical plant responses that are similar to the ones induced by an attack of fungal pathogens, i.e. it resembles fungal elicitors. This suggests that ozone can represent a valid tool for the study of stress responses and induction of resistance to pathogens. This review provides an overview of the implications of such a phenomenon for basic and applied research. After an introduction about the environmental implications of tropospheric ozone and plant responses to biotic stresses, the biochemistry of ozone stress is analysed, pointing out its similarities with plant responses to pathogens and its possible applications.

  20. Effects of ozone-vegetation coupling on surface ozone air quality via biogeochemical and meteorological feedbacks

    Science.gov (United States)

    Sadiq, Mehliyar; Tai, Amos P. K.; Lombardozzi, Danica; Martin, Maria Val

    2017-02-01

    Tropospheric ozone is one of the most hazardous air pollutants as it harms both human health and plant productivity. Foliage uptake of ozone via dry deposition damages photosynthesis and causes stomatal closure. These foliage changes could lead to a cascade of biogeochemical and biogeophysical effects that not only modulate the carbon cycle, regional hydrometeorology and climate, but also cause feedbacks onto surface ozone concentration itself. In this study, we implement a semi-empirical parameterization of ozone damage on vegetation in the Community Earth System Model to enable online ozone-vegetation coupling, so that for the first time ecosystem structure and ozone concentration can coevolve in fully coupled land-atmosphere simulations. With ozone-vegetation coupling, present-day surface ozone is simulated to be higher by up to 4-6 ppbv over Europe, North America and China. Reduced dry deposition velocity following ozone damage contributes to ˜ 40-100 % of those increases, constituting a significant positive biogeochemical feedback on ozone air quality. Enhanced biogenic isoprene emission is found to contribute to most of the remaining increases, and is driven mainly by higher vegetation temperature that results from lower transpiration rate. This isoprene-driven pathway represents an indirect, positive meteorological feedback. The reduction in both dry deposition and transpiration is mostly associated with reduced stomatal conductance following ozone damage, whereas the modification of photosynthesis and further changes in ecosystem productivity are found to play a smaller role in contributing to the ozone-vegetation feedbacks. Our results highlight the need to consider two-way ozone-vegetation coupling in Earth system models to derive a more complete understanding and yield more reliable future predictions of ozone air quality.

  1. Advances in understanding ozone impact on forest trees: messages from novel phytotron and free-air fumigation studies.

    Science.gov (United States)

    Matyssek, R; Karnosky, D F; Wieser, G; Percy, K; Oksanen, E; Grams, T E E; Kubiske, M; Hanke, D; Pretzsch, H

    2010-06-01

    Recent evidence from novel phytotron and free-air ozone (O3) fumigation experiments in Europe and America on forest tree species is highlighted in relation to previous chamber studies. Differences in O3 sensitivity between pioneer and climax species are examined and viewed for trees growing at the harsh alpine timberline ecotone. As O3 apparently counteracts positive effects of elevated CO2 and mitigates productivity increases, response is governed by genotype, competitors, and ontogeny rather than species per se. Complexity in O3 responsiveness increased under the influence of pathogens and herbivores. The new evidence does not conflict in principle with previous findings that, however, pointed to a low ecological significance. This new knowledge on trees' O3 responsiveness beyond the juvenile stage in plantations and forests nevertheless implies limited predictability due to complexity in biotic and abiotic interactions. Unravelling underlying mechanisms is mandatory for assessing O3 risks as an important component of climate change scenarios.

  2. Low temperatures enhance organic nitrate formation: evidence from observations in the 2012 Uintah Basin Winter Ozone Study

    Directory of Open Access Journals (Sweden)

    L. Lee

    2014-06-01

    Full Text Available Nitrogen dioxide (NO2 and total alkyl nitrates (ΣANs were measured using thermal dissociation laser induced fluorescence during the 2012 Uintah Basin Winter Ozone Study (UBWOS in Utah, USA. The observed NO2 concentration was highest before sunrise and lowest in the late afternoon, suggestive of a persistent local source of NO2 coupled with turbulent mixing out of the boundary layer. In contrast, ΣANs co-varied with solar radiation with a noontime maximum, indicating that local photochemical production combined with rapid mixing and/or deposition was the dominant factor in determining the ΣAN concentrations. We calculate that ΣANs were a large fraction (~60% of the HOx free radical chain termination and show that the temperature dependence of the alkyl nitrate yields enhances the role of ΣANs in local chemistry during winter by comparison to what would occur at the warmer temperatures of summer.

  3. Impact of using different ozone cross sections on ozone profile retrievals from Global Ozone Monitoring Experiment (GOME ultraviolet measurements

    Directory of Open Access Journals (Sweden)

    X. Liu

    2007-07-01

    Full Text Available We investigate the effect of using three different cross section data sets on ozone profile retrievals from Global Ozone Monitoring Experiment (GOME ultraviolet measurements (289–307 nm, 326–337 nm. These include Bass-Paur, Brion, and GOME flight model cross sections (references below. Using different cross sections can significantly affect the retrievals, by up to 12 Dobson Units (DU, 1 DU=2.69×1016 molecules cm−2 in total column ozone, up to 10 DU in tropospheric column ozone, and up to 100% in retrieved ozone values for individual atmospheric layers. Compared to using the Bass-Paur and GOME flight model cross sections, using the Brion cross sections not only reduces fitting residuals by 15–60% in the Huggins bands, but also improves retrievals, especially in the troposphere, as seen from validation against ozonesonde measurements. Therefore, we recommend using the Brion cross section for ozone profile retrievals from ultraviolet measurements. The total column ozone retrieved using the GOME flight model cross sections is systematically lower, by 7–10 DU, than that retrieved using the Brion and Bass-Paur cross sections and is also systematically lower than Total Ozone Mapping Spectrometer (TOMS observations. This study demonstrates the need for improved ozone cross section measurements in the ultraviolet to improve profile retrievals of this key atmospheric constituent.

  4. [Characteristics of acid red 3R wastewater treatment by ozone microbubbles].

    Science.gov (United States)

    Zhang, Jing; Du, Ya-Wei; Liu, Xiao-Jing; Zhou, Yu-Wen; Liu, Chun; Yang, Jing-Liang; Zhang, Lei

    2015-02-01

    The application of microbubble technology for ozonation wastewater treatment could enhance ozone mass transfer, improve ozonation performance and increase ozone utilization efficiency. The ozone microbubbles were used to treat synthetic acid red 3R wastewater in the present study, and compared to ozone conventional bubbles. The ozone mass transfer and ozonation characteristics of acid red 3R were investigated when ozone microbubbles and ozone conventional bubbles were applied. The results confirmed the enhanced ozone mass transfer using microbubbles. The ozone mass transfer coefficient using microbubbles was 3.6 times higher than that using conventional bubbles under the same conditions. Simultaneously, the ozone decomposition coefficient using microbubbles was 6.2 times higher than that using conventional bubbles, which would be favorable for *OH generation. The ozonation rate and mineralization efficiency of acid red 3R could be improved significantly using ozone microbubbles. A TOC removal efficiency of 78.0% was achieved using ozone microbubbles, which was about 2 times higher than that using ozone conventional bubbles. The ozone utilization efficiency using microbubbles was much higher that using conventional bubbles during ozonation treatment of acid red 3R. The average ozone utilization efficiencies were 97.8% and 69.3% when microbubbles and conventional bubbles were used, respectively. The oxidative ability of ozone microbubbles could be increased by enhancing *OH generation, and as a result, the oxidative reaction of degradation intermediates was accelerated by ozone microbubbles. Especially, the mineralization ability of small organic acid intermediates using ozone microbubbles was about 1.6 times higher than that using ozone conventional bubbles.

  5. Symptoms of ozone-induced foliar injury on horticultural crops

    Energy Technology Data Exchange (ETDEWEB)

    Kostka-Rick, R. [Biologisch Ueberwachen und Bewerten, Echterdingen (Germany); Bender, J.; Bergmann, E.; Weigel, H.J. [Federal Agricultural Research Centre Braunschweig (FAL), Braunschweig (Germany). Inst. of Agroecology

    2002-07-01

    An ozone fumigation study has been conducted which aims to identify characteristic visible ozone symptoms on horticultural plant species and cultivars of economic significance that might help farmers as a diagnostic reference as well as increase people's awareness of the deleterious effects of ozone on vegetation. In most of the species and cultivars studied, specific ozone-induced foliar injury was observed. (orig.)

  6. Effectiveness of ozone against periodontal pathogenic microorganisms.

    Science.gov (United States)

    Huth, Karin C; Quirling, Martina; Lenzke, Stefanie; Paschos, Ekaterini; Kamereck, Klaus; Brand, Korbinian; Hickel, Reinhard; Ilie, Nicoleta

    2011-06-01

    Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

  7. Extracellular polymers of ozonized waste activated sludge.

    Science.gov (United States)

    Liu, J C; Lee, C H; Lai, J Y; Wang, K C; Hsu, Y C; Chang, B V

    2001-01-01

    Effect of ozonation on characteristics of waste activated sludge was investigated in the current study. Concentrations of cell-bound extracellular polymers (washed ECPs) did not change much upon ozonation, whereas the sum of cell-bound and soluble extracellular polymers (unwashed ECPs) increased with increasing ozone dose. Washed ECPs in original sludge as divided by molecular weight distribution was 39% 10,000 Da (high MW). It was observed that the low-MW fraction decreased, and the high-MW fraction increased in ozonized sludge. The unwashed ECPs were characterized as 44% in low MW, 30% in medium MW, and 26% in high MW. Both low-MW and medium-MW fractions of unwashed ECPs decreased while high-MW fraction increased in ozonized sludge. The dewaterability of ozonized sludge, assessed by capillary suction time (CST) and specific resistance to filtration (SRF), deteriorated with ozone dose. The optimal dose of cationic polyelectrolyte increased with increasing ozone dose. The production rate and the accumulated amount of methane gas of ozonized sludge were also higher.

  8. Experimental and theoretical studies of nuclear generation of ozone from oxygen and oxygen-sulfur hexafluoride mixtures

    Science.gov (United States)

    Elsayed-Ali, H. E.; Miley, G. H.

    1986-08-01

    A series of experimental measurements of the yield of O3 in nuclear-induced O2 and O2-SF6 discharges are reported. The discharges were created by bombardment with energetic particles from the 10B(n,α)7Li reaction. Continuous irradiation at dose rates of 1015-1017 eV cm-3 s-1 and pulsed irradiation (˜10 ms FWHM) at a peak dose rate of ˜1020 eV cm-3 s-1 were conducted. At the lower dose rates, the addition of SF6 generally increased the ozone yield due to the slowing of ozone destruction by negative oxygen and ozone ions. In contrast, at the high dose rates, the ozone concentration decreased due to SF6 suppression of atomic oxygen formation by ion-ion recombination. A numerical model was developed and tested against experimental conditions. This model indicates that the steady-state ozone concentration was limited by the reaction O-3+O3→2O2+O-2 with a rate coefficient of ˜1×10-12 cm3 s-1. In addition to dose rate effects, pressure and temperature effects on ozone production are discussed and methods for increasing the ozone yield are suggested.

  9. A study of vibrational excitations of ozone in the framework of a polyad preserving model of interacting Morse oscillators

    Science.gov (United States)

    Bermúdez-Montaña, M.; Lemus, R.

    2017-01-01

    The vibrational spectroscopic description of the ozone molecule 16O3 in its electronic ground state X1A1 is presented in the framework of a simple local model, where Morse potentials are associated with both stretching and bending modes. The Hamiltonian is written in terms of internal coordinates considering the local mode character of the ozone molecule. Later on an algebraic representation in terms of Morse ladder operators is introduced through a linear approximation in the expansion of the coordinates and momenta. Three polyads are considered in our study: P11 =ν1 +ν3 +ν2 , P21 = 2 (ν1 +ν3) +ν2 , and P32 = 3 (ν1 +ν3) + 2ν2 , as suggested by resonances derived from the fundamentals as well as from previous variational analysis. The best description is provided by the P11 polyad scheme, yielding an rms deviation of 1.85 cm-1 for a fit involving 121 energy levels. Considering the other two polyads the description is less accurate: rms = 2.78 cm-1 for polyad P21 and rms = 2.63 cm-1 for polyad P32 , considering 99 and 100 energy levels, respectively. These fits represent the best descriptions in the framework of an algebraic approach. In addition, since our algebraic model keeps the connection with configuration space, the force constants derived from the three fits have been estimated. We have found that all the available experimental energies may be assigned at least to one of the three fits. As the energy increases the eigenstates obtained from different polyad schemes differ. This fact paves the way to establish a polyad breaking approach as a next step to improve the description.

  10. Cloud sensitivity studies for stratospheric and lower mesospheric ozone profile retrievals from measurements of limb scattered solar radiation

    Directory of Open Access Journals (Sweden)

    T. Sonkaew

    2009-02-01

    Full Text Available Clouds in the atmosphere play an important role in reflection, absorption and transmission of solar radiation affecting trace gas retrievals. The main goal of this paper is to examine the sensitivity of stratospheric and lower mesospheric ozone retrievals from limb-scattered radiance measurements to clouds using the SCIATRAN radiative transfer model and retrieval package. Assuming an aerosol-free atmosphere and Mie phase functions for cloud particles, we compute the relative error of ozone profile retrievals in a cloudy atmosphere if clouds are neglected in the retrieval. To access altitudes from the lower stratosphere up to lower mesosphere, we combine the retrievals in the Chappuis and Hartley ozone absorption bands. We find significant cloud sensitivity of the limb ozone retrievals in the Chappuis bands at lower stratospheric altitudes. The relative error in the retrieved ozone concentrations gradually decreases with increasing altitude and becomes negligible above about 40 km. The parameters with the largest impact on the ozone retrievals are cloud optical thickness, ground albedo and solar zenith angle. Clouds with different geometrical thicknesses or different cloud altitudes have a similar impact on the ozone retrievals for a given cloud optical thickness value, if the clouds are outside the field of view of the instrument. The effective radius of water droplets has a small influence on the error, i.e., less than 0.5% at altitudes above the cloud top height. Furthermore, the impact of clouds on the ozone profile retrievals was found to have a rather small dependence on the solar azimuth angle (less than 1% for all possible azimuth angles. For the most frequent cloud types the total error is below 6% above 15 km altitude, if clouds are completely neglected in the retrieval. Neglecting clouds in the ozone profile retrievals generally leads to a low bias for a low ground albedo and to a high bias for a high ground albedo, assuming that the

  11. A Case Study On the Relative Influence of Free Tropospheric Subsidence, Long Range Transport and Local Production in Modulating Ozone Concentrations over Qatar

    Science.gov (United States)

    Ayoub, Mohammed; Ackermann, Luis; Fountoukis, Christos; Gladich, Ivan

    2016-04-01

    The Qatar Environment and Energy Research Institute (QEERI) operates a network of air quality monitoring stations (AQMS) around the Doha metropolitan area and an ozonesonde station with regular weekly launches and occasional higher frequency launch experiments (HFLE). Six ozonesondes were launched at 0700 LT/0400 UTC and 1300 LT/1000 UTC over a three day period between 10-12 September, 2013. We present the analysis of the ozonesonde data coupled with regional chemical transport modeling over the same time period using WRF-Chem validated against both the ozonesonde and surface AQMS measurements. The HFLE and modeling show evidence of both subsidence and transboundary transport of ozone during the study period, coupled with a strong sea breeze circulation on the 11th of September resulting in elevated ozone concentrations throughout the boundary layer. The development of the sea breeze during the course of the day and influence of the early morning residual layer versus daytime production is quantified. The almost complete titration of ozone in the morning hours of 11 September, 2013 is attributed to local vehicular emissions of NOx and stable atmospheric conditions prevailing over the Doha area. The relative contribution of long range transport of ozone along the Arabian Gulf coast and local urban emissions are discussed.

  12. Semiclassical wave packet study of anomalous isotope effect in ozone formation.

    Science.gov (United States)

    Vetoshkin, Evgeny; Babikov, Dmitri

    2007-10-21

    We applied the semiclassical initial value representation method to calculate energies, lifetimes, and wave functions of scattering resonances in a two-dimensional potential for O+O2 collision. Such scattering states represent the metastable O3* species and play a central role in the process of ozone formation. Autocorrelation functions for scattering states were computed and then analyzed using the Prony method, which permits one to extract accurate energies and widths of the resonances. We found that the results of the semiclassical wave packet propagation agree well with fully quantum results. The focus was on the 16O16O18O isotopomer and the anomalous isotope effect associated with formation of this molecule, either through the 16O16O+18O or the 16O+16O18O channels. An interesting correlation between the local vibration mode character of the metastable states and their lifetimes was observed and explained. New insight is obtained into the mechanism by which the long-lived resonances in the delta zero-point energy part of spectrum produce the anomalously large isotope effect.

  13. Experimental and modeling study of the impact of vertical transport processes from the boundary-layer on the variability and the budget of tropospheric ozone; Etude experimentale et numerique de l'influence des processus de transport depuis la couche-limite sur la variabilite et le bilan d'ozone tropospherique

    Energy Technology Data Exchange (ETDEWEB)

    Colette, A

    2005-12-15

    Closing the tropospheric ozone budget requires a better understanding of the role of transport processes from the major reservoirs: the planetary boundary layer and the stratosphere. Case studies lead to the identification of mechanisms involved as well as their efficiency. However, their global impact on the budget must be addressed on a climatological basis. This manuscript is thus divided in two parts. First, we present case studies based on ozone LIDAR measurements performed during the ESCOMPTE campaign. This work consists in a data analysis investigation by means of a hybrid - Lagrangian study involving: global meteorological analyses, Lagrangian particle dispersion computation, and mesoscale, chemistry - transport, and Lagrangian photochemistry modeling. Our aim is to document the amount of observed ozone variability related to transport processes and, when appropriate, to infer the role of tropospheric photochemical production. Second, we propose a climatological analysis of the respective impact of transport from the boundary-layer and from the tropopause region on the tropospheric ozone budget. A multivariate analysis is presented and compared to a trajectography approach. Once validated, this algorithm is applied to the whole database of ozone profiles collected above Europe during the past 30 years in order to discuss the seasonal, geographical and temporal variability of transport processes as well as their impact on the tropospheric ozone budget. The variability of turbulent mixing and its impact on the persistence of tropospheric layers will also be discussed. (author)

  14. Observações sôbre a produtividade de seringueiras (Hevea brasiliensis muell.-arg. plantadas de sementes: V - Produtividade de 15 plantas existentes no Instituto Agronômico do Norte, Belém, Pá Observations on the latex production of seedlings of rubber tree (Hevea brasiliensis muell.-arg.: V - Study of 15 plants of the Instituto Agronômico do Norte, Belém, Pará

    Directory of Open Access Journals (Sweden)

    Luiz O. T. Mendes

    1960-01-01

    Full Text Available São apresentados os resultados da sangria de 15 seringueiras plantadas de sementes e existentes no instituto Agronômico do Norte, que na data do início dos trabalhos tinham idade média superior a 30 anos. Os trabalhos foram executados de março de 1943 a setembro de 1944, sendo a sangria realizada a meia espiral, em dias alternados. É feito um estudo comparativo da produção em um e outro ano, bem como nos dois períodos em que foram divididos os anos. Logo após curto período de sangria a melhor planta classificou-se em primeiro lugar, pela sua produtividade. O estudo da população como um todo confirma resultados anteriores, de que pequena parte das plantas contribui com a maior parte da produção, em lotes de seringueiras obtidas de sementes não selecionadas.The results of topping 15 seedlings of rubber tree (Hevea brasiliensis Muell.-Arg. approximately 30 years old are presented. The tapping system adopted was an half-spiral cut, tapped every other day in the morning. The initial height of opening the tap was one meter above the soil, the cut made at an angle of 30° counterclockwise downward. After the results were collected, the length of the cuts was measured and as it was observed that almost all cuts were much shorter than they should be, a correction was introduced, based in the girth of the trees and their respective daily production expressed in cc of latex per cm of length of cut. The best plant yielded 35% of the total production of 10 plants studied from March 16, 1943 to September 30, 1944. The study of the plants as a group presents the following results: a 10% of the plant population yielded 35% of the total latex production; b 50% of the plant population yielded 79% of the total latex production; c 70% of the plant population yielded 90% of the total latex production. The data confirm that in order to find out the best yielding plant of a group of unselected seedlings it is not necessary to tap the trees for a long

  15. Basic Ozone Layer Science

    Science.gov (United States)

    Learn about the ozone layer and how human activities deplete it. This page provides information on the chemical processes that lead to ozone layer depletion, and scientists' efforts to understand them.

  16. Ozone Layer Protection

    Science.gov (United States)

    ... Search Search Ozone Layer Protection Share Facebook Twitter Google+ Pinterest Contact Us Ozone Layer Protection Welcome to ... Managing Refrigerant Emissions Stationary Refrigeration and Air Conditioning Car and Other Mobile Air Conditioning GreenChill Partnership Responsible ...

  17. The Comparison between Two Methods for the Relief of Knee Osteoarthritis Pain: Radiofrequency and Intra-Periarticular Ozone Injection: A Clinical Trial Study

    Directory of Open Access Journals (Sweden)

    Masoud Hashemi

    2016-07-01

    Full Text Available Knee osteoarthritis is not always well controlled by usual treatments, therefore new therapeutic methods such as radiofrequency and ozone injection should be investigated. Comparing the efficacy of two methods: radiofrequency and intra-periarticular ozone injection. This randomized clinical trial study was performed in an academic Pain Clinic of Guilan University of Medical Sciences in Iran from September 2014 to June 2015. The research was carried out on seventy-two patients, were randomly allocated in two groups by triple blocks. thirty-six patients in ozone group received intra-periarticular ozone injection and 36 patients in RF group, after a positive diagnostic genicular nerve blocks received Conventional Radiofrequency(CRFand then intra articular Pulse Radiofrequency(PRF. The evaluation was based on Visual Analog Scale (VAS and Oxford Knee Score (OKS before and 12 weeks after the procedure. The analysis was performed by paired t-test, Fisher, Chi square and Mann-Whitney-U tests in SPSS version18. In Ozone group the mean of initial OKS was 38.77±7.75 compare to 41.22±7.44 in RF group. After 12 weeks, it diminish ed to 21.77±7.78 and 22±6.21 respectively (p=0.0001 . In Ozone group VAS decreased from 9±1.43 to 3.38±1.79 (p=0.0001 while in RF group from 9.44±0.85 to 2.77±1.06 (p=0.0001. Comparing two methods, there was no significant difference between two groups based on OKS(p=0.23 and VAS (p=0.202. Also RF resulted in more acceptable pain relief based on OKS among subjects older than 65 years (p=0.0001. Both radiofrequency and intra-periarticular ozone injection have good clinical effects on knee osteoarthritis with superiority of radio frequency in age above 65 years old.

  18. Ozone Layer Observations

    Science.gov (United States)

    McPeters, Richard; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV and SAGE (Stratospheric Aerosol and Gas Experiment) instruments for example, show that the largest changes are occurring in the lower stratosphere and upper troposphere. The goal of ozone measurement in the next decades will be to document the predicted recovery of the ozone layer as CFC (chlorofluorocarbon) levels decline. This will require a continuation of global measurements of total column ozone on a global basis, but using data from successor instruments to TOMS. Hyperspectral instruments capable of measuring in the UV will be needed for this purpose. Establishing the relative roles of chemistry and dynamics will require instruments to measure ozone in the troposphere and in the stratosphere with good vertical resolution. Instruments that can measure other chemicals important to ozone formation and destruction will also be needed.

  19. Numerical simulation for regional ozone concentrations: A case study by weather research and forecasting/chemistry (WRF/Chem) model

    OpenAIRE

    Khandakar Md Habib Al Razi, Moritomi Hiroshi

    2013-01-01

    The objective of this research is to better understand and predict the atmospheric concentration distribution of ozone and its precursor (in particular, within the Planetary Boundary Layer (Within 110 km to 12 km) over Kasaki City and the Greater Tokyo Area using fully coupled online WRF/Chem (Weather Research and Forecasting/Chemistry) model. In this research, a serious and continuous high ozone episode in the Greater Tokyo Area (GTA) during the summer of 14–18 August 2010 was investigated u...

  20. Hydrocarbon Observations and Ozone Production Rates in Western Houston During the Texas 2000 Air Quality Study

    Energy Technology Data Exchange (ETDEWEB)

    Berkowitz, Carl M.; Spicer, Chet W.; Doskey, Paul V.

    2005-06-01

    Measurements of total non-methane hydrocarbon in whole air canisters collected from the top of a skyscraper on the western edge of Houston, Texas are summarized with an emphasis on samples collected during the passage of plumes of O{sub 3} and the associated rapid increase in the mixing ratio of this species. The back-trajectories associated with these events showed a pronounced deceleration of air parcels over central and western Houston and were not necessarily associated with direct passage over the petrochemical plants located in the heavily industrialized eastern part of Houston. As a result of the time these air parcels spent over the central and western parts of Houston, their VOC mix and associated chemical production rates were expected to differ from similar observations made over eastern Houston from aircraft sampling at low altitudes. Although periods of high O{sub 3} in the western part of the city were closely associated with light alkenes, these same observations show isoprene to make a significant contribution to the total VOC reactivity in the early afternoon (the start of peak photochemical activity) in contrast to observations made east of our sampling site that found the reactivity to be dominated by anthropogenic species. By initializing a 0-dimensional chemical kinetic model with observations made at the Williams Tower, we find that the ozone production efficiency scaled linearly to the ratio of total hydrocarbons and NO{sub x}, with an average OPE of 7.2, ranging from 2.3 to 16.9; these values are smaller than those reported in eastern Houston, suggesting a strong gradient in photochemical productivity across the city.

  1. Distinctive timing of US historical surface ozone change determined by climate and anthropogenic emissions

    Science.gov (United States)

    Yan, Yingying; Lin, Jintai

    2016-04-01

    Future changes in surface ozone in a warming climate is an important question for the United States. Analyses of historical ozone change in response to climate change, although useful for validating theories regarding future ozone changes, are complicated by concurrent changes in anthropogenic emissions. Here we find that the individual contributions of climate and precursor emissions to US historical ozone changes over 1990-2014 can be distinguished by contrasting the changes in daytime versus nighttime ozone, based on an analysis of observed and simulated annual mean ozone time series. In particular, climate variability has determined ozone interannual variability, particularly for the daytime ozone, while reductions of anthropogenic NOx emissions have primarily driven an increase in the nighttime ozone. Our results have important implications for future ozone change studies and ozone mitigation.

  2. History of mesquite introduction in Rio Grande do Norte State, Brazil

    Directory of Open Access Journals (Sweden)

    João Paulo Silva dos Santos

    2017-06-01

    Full Text Available The mesquite (Prosopis juliflora (Sw DC was established as a successful action of xerophilous introduction in Brazilian Northeast dry region. Its fruits are used in animal feed and the wood may be used as piles, firewood and charcoal. The species was introduced in 1942, spreading in "low areas" in Rio Grande do Norte, Paraiba, Pernambuco, Bahia and Piauí States. This article aims to elucidate how mesquite was introduced in Rio Grande do Norte State and to understand how it was spread. It was first introduced in Rio Grande do Norte State by the introduction experiments installed at São Miguel farm in the municipality of Angicos. The enthusiasm of technicians and researchers promoted the distribution of pods and seedlings on farms and cities in the state. In addition, there were government incentives to production, distribution and planting the species. This work aims to establish considerations to be used as historical basis on studies about this species and to consider aspects regarding current situation of this culture in Brazilian Northeast.

  3. Colorado Front Range Surface Ozone Analysis

    Science.gov (United States)

    McClure-Begley, A.; Petropavlovskikh, I. V.; Oltmans, S. J.; Kofler, J.; Petron, G.; Cothrel, H.

    2014-12-01

    The Colorado Front Range is a unique geographical region for air quality studies, including research of surface level ozone. Not only does surface ozone play a critical role in regulating the oxidation capacity of the atmosphere, but is a primary contributor to local smog and leads to public health complications and altered ecosystem functioning. The high frequency of sunny days, increasing population and pollution, and Mountain/Valley air dynamics of this region provide atmospheric conditions suitable for production and accumulation of ozone at the surface. This region of Colorado is currently in an ozone non-attainment status due to an assortment of contributing factors. Precursor emissions from pollution, wild-fires, and gas and oil production; along with stratosphere-troposphere exchange, can all result in high ozone episodes over the Colorado Front Range. To understand the dynamics of ozone accumulation in this region, Thermo-Scientific ozone monitors have been continuously sampling ozone from 4 different altitudes since the early 2000s. Analysis of ozone data in relation to Nitrogen Oxides (NOx), Methane (CH4), Carbon Monoxide (CO), wind-conditions and back-trajectory air mass origins help to address local ozone precursor emissions and resulting high ozone episodes. Increased ozone episodes are scrutinized with regards to dominant wind direction to determine main precursor emission sources. Analysis of this data reveals a strong influence of precursor emissions from the North-East wind sector, with roughly 50% of ozone exceedances originating from winds prevailing from this direction. Further, correlation with methane is enhanced when prevailing winds are from the North-East; indicative of influence from natural gas processes and feedlot activity. Similar analysis is completed for the North-West wind sector exceedances, with strong correlation to carbon monoxide; likely related to emissions from biomass burning events and forest fires. In depth analysis of

  4. en América del Norte

    Directory of Open Access Journals (Sweden)

    Alejandro Mercado Celis

    2006-01-01

    Full Text Available Las brechas tecnológicas entre países y regiones son la pieza clave en la diferenciación económica y en las tasas de crecimiento resultantes. Los países y regiones menos desarrollados pueden fomentar competencias tecnológicas con estrategias diferentes. El mejor momento para que este tipo de países ingrese en la competencia por el control tecnológico es cuando las tecnologías y los conocimientos relacionados con ellas están en una etapa inicial, a lo que se le conoce como ventana de oportunidad tecnológica y locacional. En este artículo, se argumenta que la ventana de oportunidad de la biotecnología aún está abierta, y que México todavía puede entrar en la competencia mundial por su desarrollo. No obstante lo anterior, se documenta que Canadá y Estados Unidos están generando ventajas absolutas con rapidez, por lo que las ventanas de oportunidad en algunas áreas pronto estarán "cerradas". Se presentan las regiones que dominan la creación de aplicaciones comerciales en biotecnología en la región de América del Norte. En particular, se subraya el papel destacado que algunas ciudades canadienses están jugando en el desarrollo de esta industria, pese a la competencia estadounidense.

  5. estudiantes de la Universidad del Norte

    Directory of Open Access Journals (Sweden)

    María Mercedes Botero

    2008-01-01

    Full Text Available El objetivo de esta investigación fue establecer la relación que existe entre el self y el consumo en 364 hombres y mujeres con edades entre 18 y 24 años, estudiantes de la Universidad del Norte, en la ciudad de Barranquilla, Colombia. El self se define como el producto de la internalización en la constante reinterpretación de la interacción individuo-sociedad. Según Luna-Arocas (1998, la identidad o self está compuesta por siete dimensiones: dimensión intelectual, física, belleza física, personal, social, emocional y socioeconómica. A veces estas dimensiones se construyen como partes independientes que afectan a una unicidad global denominada autoconcepto (Luna-Arocas 2005. La muestra del estudio estuvo conformada por 364 estudiantes, el 53.6 % eran mujeres y el 46,4%, hombres. Los participantes fueron seleccionados mediante un muestreo aleatorio simple. El instrumento utilizado está basado en el NESE, que diseñó y validó Roberto Luna-Arocas (1996 y fue modificado por las investigadoras, que lo conformaron con 114 ítems, y le consiguieron un índice de confiabilidad de 0.948. El análisis de los resultados arroja datos muy importantes para la comprensión de la Psicología del Consumidor, particularmente, acerca de sus comportamientos, que demuestran la existencia de una correlación significativa y directamente proporcional entre la variable self y consumo, (0.613

  6. Relative Contribution of Greenhouse Gases and Ozone Change to Temperature Trends in the Stratosphere: A Chemistry/Climate Model Study

    Science.gov (United States)

    Stolarski, Richard S.; Douglass, A. R.; Newman, P. A.; Pawson, S.; Schoeberl, M. R.

    2006-01-01

    Long-term changes in greenhouse gases, primarily carbon dioxide, are expected to lead to a warming of the troposphere and a cooling of the stratosphere. We examine the cooling of the stratosphere and compare the contributions greenhouse gases and ozone change for the decades between 1980 and 2000. We use 150 years of simulation done with our coupled chemistry/climate model (GEOS 4 GCM with GSFC CTM chemistry) to calculate temperatures and constituents fiom,1950 through 2100. The contributions of greenhouse gases and ozone to temperature change are separated by a time-series analysis using a linear trend term throughout the period to represent the effects of greenhouse gases and an equivalent effective stratospheric chlorine (EESC) term to represent the effects of ozone change. The temperature changes over the 150 years of the simulation are dominated by the changes in greenhouse gases. Over the relatively short period (approx. 20 years) of ozone decline between 1980 and 2000 changes in ozone are competitive with changes in greenhouse gases. The changes in temperature induced by the ozone change are comparable to, but smaller than, those of greenhouse gases in the upper stratosphere (1-3 hPa) at mid latitudes. The ozone term dominates the temperature change near both poles with a negative temperature change below about 3-5 hPa and a positive change above. At mid latitudes in the upper stratosphere and mesosphere (above about 1 hPa) and in the middle stratosphere (3 to 70 ma), the greenhouse has term dominates. From about 70 hPa down to the tropopause at mid latitudes, cooling due to ozone changes is the largest influence on temperature. Over the 150 years of the simulation, the change in greenhouse gases is the most important contributor to temperature change. Ozone caused a perturbation that is expected to reverse over the coming decades. We show a model simulation of the expected temperature change over the next two decades (2006-2026). The simulation shows a

  7. Antarctic ozone loss in 1989–2010: evidence for ozone recovery?

    Directory of Open Access Journals (Sweden)

    A. Pazmiño

    2012-04-01

    yr to get the first detectable ozone recovery signal at the 95% confidence intervals with the current ozone trends in the Antarctic. Thus, this study reveals that the recovery of the Antarctic ozone is well on course.

  8. Line parameter study of ozone at 5 and 10 μm using atmospheric FTIR spectra from the ground: A spectroscopic database and wavelength region comparison

    Science.gov (United States)

    Janssen, Christof; Boursier, Corinne; Jeseck, Pascal; Té, Yao

    2016-08-01

    Atmospheric ozone concentration measurements mostly depend on spectroscopic methods that cover different spectral regions. Despite long years of measurement efforts, the uncertainty goal of 1% in absolute line intensities has not yet been reached. Multispectral inter-comparisons using both laboratory and atmospheric studies reveal that important discrepancies exist when ozone columns are retrieved from different spectral regions. Here, we use ground based FTIR to study the sensitivity of ozone columns on different spectroscopic parameters as a function of individual bands for identifying necessary improvements of the spectroscopic databases. In particular, we examine the degree of consistency that can be reached in ozone retrievals using spectral windows in the 5 and 10 μm bands of ozone. Based on the atmospheric spectra, a detailed database inter-comparison between HITRAN (version 2012), GEISA (version 2011) and S&MPO (as retrieved from the website at the end of 2015) is made. Data from the 10 μm window are consistent to better than 1%, but there are larger differences when the windows at 5 μm are included. The 5 μm results agree with the results from 10 μm within ±2% for all databases. Recent S&MPO data are even more consistent with the desired level of 1%, but spectroscopic data from HITRAN give about 4% higher ozone columns than those from GEISA. If four sub-windows in the 5 μm band are checked for consistency, retrievals using GEISA or S&MPO parameters show less dispersion than those using HITRAN, where one window in the P-branch of the ν1 + ν3 band gives about 2% lower results than the other three. The atmospheric observations are corroborated by a direct comparison of the spectroscopic databases, using a simple statistical analysis based on intensity weighted spectroscopic parameters. The bias introduced by the weighted average approach is investigated and it is negligible if relative differences between databases do not correlate with line

  9. Control of dangerous substances in discharges and microbiological abatement: European framework and a case study of an ozone disinfection system.

    Science.gov (United States)

    Ostoich, M; Serena, F; Falletti, L; Fantoni, A

    2013-01-01

    Directive 2000/60/EC requires the achievement of a 'good chemical status' for surface water within pre-established dates. Disinfection is needed to achieve compulsory final microbial limit values (in Italy for wastewater discharges the parameter Escherichia coli - EC - is imposed by law with a maximum limit value of 5,000 cfu/100 mL). Liquid waste and disinfection by-products must be considered when designing appropriate monitoring of dangerous substances; the specific classes of substances must be investigated according to the typology of received wastewaters and liquid wastes (where applicable) and specific analytical techniques, with Limit of Detection (LOD) lower than the limit values, must be applied; the difficulties faced by national and regional environmental control Agencies is that these techniques have to be applied during ordinary activity and not only for research purposes. The study aims to present the control of dangerous substances, as a screening view, in wastewater treatment plant (WWTP) discharges in the province of Venice (Northern Italy) for the period 2007-2010 based on available data from institutional controls. In addition, the wastewater disinfection process with ozone applied to a medium size WWTP (45,000 Population Equivalents) is presented as a case study, with a view to assessing the microbiological abatement efficacy and the presence of dangerous substances. Discharge quality of the WWTPs in the province of Venice presented mean values that were higher than the LOD, but only for certain metals. For the Paese plant, zinc and chloroform were the only micro-pollutants detected with a higher level than the LOD. From microbiological data in the period 2006-2011 the disinfection abatement efficiency for Paese was, in most cases above 99% for EC, faecal coliform (FC), faecal streptococci (FS) while efficiency was slightly lower for total coliform (TC); however, the proposed criterion aimed at respecting 99.99% abatement was not completely

  10. Statistical estimation of ozone exposure metrics

    Science.gov (United States)

    Blankenship, Erin E.; Stefanski, L. A.

    Data from recent experiments at North Carolina State University and other locations provide a unique opportunity to study the effect of ambient ozone on the growth of clover. The data consist of hourly ozone measurements over a 140 day growing season at eight sites in the US, coupled with clover growth response data measured every 28 days. The objective is to model an indicator of clover growth as a function of ozone exposure. A common strategy for dealing with the numerous hourly ozone measurements is to reduce these to a single summary measurement, a so-called exposure metric, for the growth period of interest. However, the mean ozone value is not necessarily the best summarization, as it is widely believed that low levels of ozone have a negligible effect on growth, whereas peak ozone values are deleterious to plant growth. There are also suspected interactions with available sunlight, temperature and humidity. A number of exposure metrics have been proposed that reflect these beliefs by assigning different weights to ozone values according to magnitude, time of day, temperature and humidity. These weighting schemes generally depend on parameters that have, to date, been subjectively determined. We propose a statistical approach based on profile likelihoods to estimate the parameters in these exposure metrics.

  11. Ozone Therapy in Treatment of Female Infertility

    Directory of Open Access Journals (Sweden)

    Maradi A. Burduli

    2015-03-01

    Full Text Available Ozone therapy and physiotherapy have been successfully used in obstetric practice. The paper summarizes the results of studies on the use of ozone therapy in the postoperative rehabilitation of gynecological patients operated on for female infertility of various origins. Biomechanisms systemic impact methods of ozone therapy on the human body to meet the requirements of the tactics of the impact on the etiopathogenic mechanisms of chronic inflammatory diseases of the pelvic organs and their complications. It is advisable to wider use of ozone therapy in the complex treatment standards gynecological patients. Postoperative rehabilitation, including ozone therapy, can have a significant impact on the clinical course of gynecological and extragenital pathology, pregnancy rate and its outcomes.

  12. Computational analysis of ozonation in bubble columns

    Energy Technology Data Exchange (ETDEWEB)

    Quinones-Bolanos, E. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]|[Univ. de Cartagena, Facultad de Ciencias e Ingenieria, Cartagena de Indias (Colombia); Zhou, H.; Otten, L. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: hzhou@uoguelph.ca

    2002-06-15

    This paper presents a new computational ozonation model based on the principle of computational fluid dynamics along with the kinetics of ozone decay and microbial inactivation to predict the performance of ozone disinfection in fine bubble columns. The model can be represented using a mixture two-phase flow model to simulate the hydrodynamics of the water flow and using two transport equations to track the concentration profiles of ozone and microorganisms along the height of the column, respectively. The applicability of this model was then demonstrated by comparing the simulated ozone concentrations with experimental measurements obtained from a pilot scale fine bubble column. One distinct advantage of this approach is that it does not require the prerequisite assumptions such as plug flow condition, perfect mixing, tanks-in-series, uniform radial or longitudinal dispersion in predicting the performance of disinfection contactors without carrying out expensive and tedious tracer studies. (author)

  13. An overview of the 2013 Las Vegas Ozone Study (LVOS): Impact of stratospheric intrusions and long-range transport on surface air quality

    Science.gov (United States)

    Langford, A. O.; Senff, C. J.; Alvarez, R. J.; Brioude, J.; Cooper, O. R.; Holloway, J. S.; Lin, M. Y.; Marchbanks, R. D.; Pierce, R. B.; Sandberg, S. P.; Weickmann, A. M.; Williams, E. J.

    2015-05-01

    The 2013 Las Vegas Ozone Study (LVOS) was conducted in the late spring and early summer of 2013 to assess the seasonal contribution of stratosphere-to-troposphere transport (STT) and long-range transport to surface ozone in Clark County, Nevada and determine if these processes directly contribute to exceedances of the National Ambient Air Quality Standard (NAAQS) in this area. Secondary goals included the characterization of local ozone production, regional transport from the Los Angeles Basin, and impacts from wildfires. The LVOS measurement campaign took place at a former U.S. Air Force radar station ∼45 km northwest of Las Vegas on Angel Peak (∼2.7 km above mean sea level, asl) in the Spring Mountains. The study consisted of two extended periods (May 19-June 4 and June 22-28, 2013) with near daily 5-min averaged lidar measurements of ozone and backscatter profiles from the surface to ∼2.5 km above ground level (∼5.2 km asl), and continuous in situ measurements (May 20-June 28) of O3, CO, (1-min) and meteorological parameters (5-min) at the surface. These activities were guided by forecasts and analyses from the FLEXPART (FLEXible PARTticle) dispersion model and the Real Time Air Quality Modeling System (RAQMS), and the NOAA Geophysical Research Laboratory (NOAA GFDL) AM3 chemistry-climate model. In this paper, we describe the LVOS measurements and present an overview of the results. The combined measurements and model analyses show that STT directly contributed to each of the three O3 exceedances that occurred in Clark County during LVOS, with contributions to 8-h surface concentrations in excess of 30 ppbv on each of these days. The analyses show that long-range transport from Asia made smaller contributions (<10 ppbv) to surface O3 during two of those exceedances. The contribution of regional wildfires to surface O3 during the three LVOS exceedance events was found to be negligible, but wildfires were found to be a major factor during exceedance events

  14. Treatment of radiculopathies: a study of efficacy and tollerability of paravertebral oxygen-ozone injections compared with pharmacological anti-inflammatory treatment.

    Science.gov (United States)

    Melchionda, D; Milillo, P; Manente, G; Stoppino, L; Macarini, L

    2012-01-01

    The study was performed to evaluate the effectiveness of lumbar paravertebral injections of a gas mixture of Oxygen and Ozone in patients with lumbar radiculopathies caused by L4-L5 or L5-S1 disk herniations compared to a pharmacological therapy based on non-steroidal anti-inflammatory drugs. Lumbar radiculopathy caused by disc herniation is widely spread. Many therapeutic options are available before steering patients to the surgery. Low back pain and sciatica represent some of the most frequent causes of antinflammatory-analgesic drugs overuse. Recent findings have shown that medical Ozone can be used in the treatment of radicular syndrome caused by herniated intervertebral discs. Although widely spread, there are insufficient published data supporting the effectiveness of this approach in clinical practice. We studied 38 affected patients with acute L5 or S1 radicolopathy. The patients were randomly divided in two groups: A) 20 patients treated with lumbar paravertebral injections of Oxygen and Ozone; B) 18 patients treated pharmacologically with antinflammatory-analgesic drugs. All patients underwent a clinical and neurological examination at baseline (T1) and after 1 (T2), 2 (T3), 4 weeks (T4) and after 3 (T5) and 6 months (T6). An MRI and EMG examination were performed at baseline and after 6 months. The intensity of pain and the outcome of treatments were evaluated in all patients with the Visual Analogue Scale and with the Oswestry Disability Index. We found a reduction of pain and discomfort soon after one week with oxygen-ozone injections compared with pharmacological treatment, but this difference of response became statistically significant after two weeks (50 percent vs 16.6 percent) and is confirmed after 3 and 6 months, when 80 percent of patients treated with injections turned out pain free compared with half of the patients treated pharmacologically. No statistical difference were found in MRI and EMG examinations. No adverse effects were found in

  15. Searching for common responsive parameters for ozone tolerance in 18 rice cultivars in India: Results from ethylenediurea studies.

    Science.gov (United States)

    Pandey, Ashutosh K; Majumder, Baisakhi; Keski-Saari, Sarita; Kontunen-Soppela, Sari; Mishra, Ashvarya; Sahu, Nayan; Pandey, Vivek; Oksanen, Elina

    2015-11-01

    Eighteen rice (Oryza sativa) cultivars were screened for ozone (O3) tolerance and for the most responsive parameters with ethylenediurea (EDU) treatments at two experimental sites experiencing high ambient O3 conditions in the Indo-Gangetic Plains (IGP) of India. EDU was applied at 15 day intervals until the final harvest phase as a foliar spray at 300 ppm in order to protect the plants from the adverse effects of O3. Antioxidant activity, malondialdehyde content (MDA), chlorophyll content, gas exchange, and chlorophyll fluorescence (Fv/Fm) at the vegetative and flowering phases and harvest-related parameters were studied, for a total of 24 parameters. Seven of the studied cultivars had higher than average grainweightplant(-1) in all site and treatment combinations and can be recommended for cultivation in areas suffering from high O3 concentrations. The most responsive parameters with EDU treatment in high O3 across all cultivars were superoxide dismutase (SOD) and catalase (CAT) activities, the contents of oxidised (GSSG) and reduced (GSH) glutathione and MDA, and shoot weight plant(-1). These results indicated that the O3 scavenging activity of EDU is mediated through an antioxidant defence system rather than a direct effect on physiological parameters, such as photosynthesis and stomatal conductance.

  16. Advances in understanding ozone impact on forest trees: Messages from novel phytotron and free-air fumigation studies

    Energy Technology Data Exchange (ETDEWEB)

    Matyssek, R., E-mail: matyssek@wzw.tum.d [Ecophysiology of Plants, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising-Weihenstephan (Germany); Karnosky, D.F. [Michigan Technological University, School of Forest Resources and Environmental Sciences, Houghton, MI 49931-129 (United States); Wieser, G. [Federal Research and Trainings Centre for Forests, Natural Hazards and Landscape, Dept. of Alpine Timberline Ecophysiology, Rennweg 1, A-6020 Innsbruck (Austria); Percy, K. [K.E. Percy Air Quality Effects Consulting Ltd., 207-230 Wilson Drive, Fort McMurray, Alberta T9H 0A4 (Canada); Oksanen, E. [Faculty of Biosciences, University of Joensuu, P.O. Box 111, FIN 80101 Joensuu (Finland); Grams, T.E.E. [Ecophysiology of Plants, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising-Weihenstephan (Germany); Kubiske, M. [Institute for Applied Ecosystem Studies, US Forest Service, Northern Research Station, 5985 Hwy K, Rhinelander, WI 54501 (United States); Hanke, D. [Department of Plant Sciences, University of Cambridge, CB2 3EA (United Kingdom); Pretzsch, H. [Forest Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising-Weihenstephan (Germany)

    2010-06-15

    Recent evidence from novel phytotron and free-air ozone (O{sub 3}) fumigation experiments in Europe and America on forest tree species is highlighted in relation to previous chamber studies. Differences in O{sub 3} sensitivity between pioneer and climax species are examined and viewed for trees growing at the harsh alpine timberline ecotone. As O{sub 3} apparently counteracts positive effects of elevated CO{sub 2} and mitigates productivity increases, response is governed by genotype, competitors, and ontogeny rather than species per se. Complexity in O{sub 3} responsiveness increased under the influence of pathogens and herbivores. The new evidence does not conflict in principle with previous findings that, however, pointed to a low ecological significance. This new knowledge on trees' O{sub 3} responsiveness beyond the juvenile stage in plantations and forests nevertheless implies limited predictability due to complexity in biotic and abiotic interactions. Unravelling underlying mechanisms is mandatory for assessing O{sub 3} risks as an important component of climate change scenarios. - Novel phytotron and free-air O{sub 3} exposure studies on forest trees communicate sensitivity to be governed by genotype, ontogeny and biotic agents rather than species per se.

  17. Mechanisms controlling surface ozone over East Asia: a multiscale study coupling regional and global chemical transport models

    Science.gov (United States)

    Lin, M.; Holloway, T.; Oki, T.; Streets, D. G.; Richter, A.

    2008-12-01

    Mechanisms controlling surface ozone (O3) over East Asia are examined using the regional Community Multiscale Air Quality (CMAQ) model at two horizontal scales: 81 km and 27 km. Through sensitivity studies and comparison with recently available satellite data and surface measurements in China and Japan, we find that the O3 budget over East Asia shows complex interactions among photochemical production, regional transport, meteorological conditions, burning of agricultural residues, and global inflows. For example, wintertime surface O3 over northern domain is sensitive to boundary conditions derived from the MOZART (Model for Ozone and Related Tracers) global model, whereas summertime O3 budget is controlled by the competitive processes between photochemical production and monsoonal intrusion of low-O3 marine air masses from tropical Pacific. We find that simulated surface O3 for 2001 does not exhibit the same sharp drop in July and August concentrations that is observed at two mountaintop sites (Tai and Hua) for 2004 and Beijing for 1995-2005. CMAQ sensitivity tests with two widely used photochemical schemes demonstrate that over the industrial areas in East Asia north of 30° N, SAPRC99 produces higher values of mean summertime O3 than CBIV, amounting to a difference of 10 ppb. In addition, analysis of NCEP winds and geopotential heights suggests that southwesterly monsoonal intrusion in central east China is weakened in August 2001 as compared with the climatologically mean for 1980-2005. Further examination of the O3 diurnal cycle at nine Japanese sites shows that boundary layer evolution has an important effect on the vertical mixing of ground-level O3, and error in near surface meteorology might contribute to overprediction of nighttime O3 in urban and rural areas. In conclusion, the uncertainties in simulating cloud activities and convection mixing, Asian monsoon circulation, photochemical production, and nighttime cooling explain why CMAQ with 81 km

  18. Mechanisms controlling surface ozone over East Asia: a multiscale study coupling regional and global chemical transport models

    Directory of Open Access Journals (Sweden)

    M. Lin

    2008-12-01

    Full Text Available Mechanisms controlling surface ozone (O3 over East Asia are examined using the regional Community Multiscale Air Quality (CMAQ model at two horizontal scales: 81 km and 27 km. Through sensitivity studies and comparison with recently available satellite data and surface measurements in China and Japan, we find that the O3 budget over East Asia shows complex interactions among photochemical production, regional transport, meteorological conditions, burning of agricultural residues, and global inflows. For example, wintertime surface O3 over northern domain is sensitive to boundary conditions derived from the MOZART (Model for Ozone and Related Tracers global model, whereas summertime O3 budget is controlled by the competitive processes between photochemical production and monsoonal intrusion of low-O3 marine air masses from tropical Pacific. We find that simulated surface O3 for 2001 does not exhibit the same sharp drop in July and August concentrations that is observed at two mountaintop sites (Tai and Hua for 2004 and Beijing for 1995–2005. CMAQ sensitivity tests with two widely used photochemical schemes demonstrate that over the industrial areas in East Asia north of 30° N, SAPRC99 produces higher values of mean summertime O3 than CBIV, amounting to a difference of 10 ppb. In addition, analysis of NCEP winds and geopotential heights suggests that southwesterly monsoonal intrusion in central east China is weakened in August 2001 as compared with the climatologically mean for 1980–2005. Further examination of the O3 diurnal cycle at nine Japanese sites shows that boundary layer evolution has an important effect on the vertical mixing of ground-level O3, and error in near surface meteorology might contribute to overprediction of nighttime O3 in urban and rural areas. In conclusion, the uncertainties in simulating cloud activities and

  19. Assessment of Solid Waste Management Strategies in Camarines Norte, Philippines

    Directory of Open Access Journals (Sweden)

    Maria Cristina C. Azuelo

    2016-11-01

    Full Text Available The Ecological Solid Waste Management Act of 2000 or RA 9003 mandates the local government units to take initiatives in managing their daunting problems on ecological solid waste disposal. Consequently, compliance of Camarines Norte, Philippines on this mandate needs assessment to determine the existing solid waste management (SWM strategies, the effectiveness and the possibility of adoption in each municipality. This study utilized the descriptive method using questionnaire as the main tool supplemented by interview. Results showed that the existing SWM strategies with the highest percentages of existence in the twelve (12 municipalities were provision of number of trucks in transporting solid wastes and knowledge on waste segregation conducted at every household/establishment. Varying levels were observed. However, high level of effectiveness is still required for significant impact, seeing that from the six areas assessed only four municipalities were identified to have more and highly effective SWM strategies. Generally, only availability of technology for composting was considered more effective and can be adopted in all municipalities. Better solid waste management may be fully attained through the involvement, political will and commitment of the implementers in the implementation of politically passed resolutions and undertaking of their initiatives that will stimulate active participation of the community. All these measures may bring change in health and environment in the province.

  20. Diagnóstico de la logística del carbón en Norte de Santander

    Directory of Open Access Journals (Sweden)

    Jorge Enrique Rodríguez-Guevara

    2015-01-01

    Full Text Available Background: The participation of Colombian coal in the international market has depended and will depend primarily on price to compete with other potential international suppliers, if the strategy is not changed to compete. Therefore one of the most important factors to consider has to do with the cost of logistics operation, in the case of Norte de Santander. Objective: The main objective of this project is to make the diagnosis of coal logistics operation in Northern Santander. Methods: Basically the methodology used was the application of polls leading experts and entrepreneurs exporters of coal in Norte de Santander. Results: One of the most important aspects that mitigate the possibility of capturing value in foreign trade are high costs in logistics operation. The identified problem occurs in the absence of studies to characterize the international physical distribution of coal in Norte de Santander, the most representative for extraction Municipalities sector. Conclusions: Finally the internationalization of the economy requires productive sectors, to shift from comparative advantages to competitive advantages. These are needed to tap international markets, however, strategic sectors for its potential reserves and features of your product, as the coal sector in Norte de Santander, not yet consolidated elements for their use.

  1. Human migration, railways and the geographic distribution of leprosy in Rio Grande do Norte State--Brazil.

    Science.gov (United States)

    Nobre, Mauricio Lisboa; Dupnik, Kathryn Margaret; Nobre, Paulo José Lisboa; Freitas De Souza, Márcia Célia; Dűppre, Nádia Cristina; Sarno, Euzenir Nunes; Jerŏnimo, Selma Maria Bezerra

    2015-12-01

    Leprosy is a public health problem in Brazil where 31,044 new cases were detected in 2013. Rio Grande do Norte is a small Brazilian state with a rate of leprosy lower than other areas in the same region, for unknown reasons. We present here a review based on the analysis of a database of registered leprosy cases in Rio Grande do Norte state, comparing leprosy's geographic distribution among municipalities with local socio-economic and public health indicators and with historical documents about human migration in this Brazilian region. The current distribution of leprosy in Rio Grande do Norte did not show correlation with socio-economic or public health indicators at the municipal level, but it appears related to economically emerging municipalities 100 years ago, with spread facilitated by railroads and train stations. Drought-related migratory movements which occurred from this state to leprosy endemic areas within the same period may be involved in the introduction of leprosy and with its present distribution within Rio Grande do Norte. Leprosy may disseminate slowly, over many decades in certain circumstances, such as in small cities with few cases. This is a very unusual situation currently and a unique opportunity for epidemiologic studies of leprosy as an emerging disease.

  2. Importance of Ship Emissions to Local Summertime Ozone Production in the Mediterranean Marine Boundary Layer: A Modeling Study

    Directory of Open Access Journals (Sweden)

    Christian N. Gencarelli

    2014-12-01

    Full Text Available Ozone concentrations in the Mediterranean area regularly exceed the maximum levels set by the EU Air Quality Directive, 2008/50/CE, a maximum 8-h mean of 120 μg·m-3, in the summer, with consequences for both human health and agriculture. There are a number of reasons for this: the particular geographical and meteorological conditions in the Mediterranean play a part, as do anthropogenic ozone precursor emissions from around the Mediterranean and continental Europe. Ozone concentrations measured on-board the Italian Research Council’s R. V. Urania during summer oceanographic campaigns between 2000 and 2010 regularly exceeded 60 ppb, even at night. The WRF/Chem (Weather Research and Forecasting (WRF model coupled with Chemistrymodel has been used to simulate tropospheric chemistry during the periods of the measurement campaigns, and then, the same simulations were repeated, excluding the contribution of maritime traffic in the Mediterranean to the anthropogenic emissions inventory. The differences in the model output suggest that, in large parts of the coastal zone of the Mediterranean, ship emissions Atmosphere 2014, 5 938 contribute to 3 and 12 ppb to ground level daily average ozone concentrations. Near busy shipping lanes, up to 40 ppb differences in the hourly average ozone concentrations were found. It seems that ship emissions could be a significant factor in the exceedance of the EU directive on air quality in large areas of the Mediterranean Basin.

  3. 电除尘器内臭氧产生规律实验研究%Experimental Study on Ozone Generation in ESP

    Institute of Scientific and Technical Information of China (English)

    柳静献; 韩永杰; 毛宁; 常德强; 孙熙

    2011-01-01

    Due to the advantages of high efficiency and low resistance,electrostatic precipitator(ESP) is widely used in many industries for smoke and dust removal,it is one of the main industrial dust control technology.But the high voltage power supply in ESP can produce ozone which may affect the equipment and materials at downstream,research on ozone production may help to operate ESP safely.In this paper,an ESP physical model is established,the relations between ozone and voltage, wind speed,location are studied with experiment.The results show that,ESP will produce ozone and the concentration of ozone increases with voltage rising,decreases with the wind speed rising,increases in the direction of air flow,the ozone concentration and voltage are approximate linear with wind speed.%静电除尘器是一种工业除尘技术,但它的高压电源在使用中会产生臭氧,可能会对后续设备及材料造成一定的影响,研究臭氧产生规律对静电除尘器的安全使用有一定的指导意义。本文通过建立电除尘器的物理模型,以实验手段研究了电除尘器中臭氧产生与电压、风速、箱体位置的规律。结果表明,静电除尘器会产生臭氧,且臭氧浓度随着电压的增大而增大,随着风速的增大而减小,沿气流流动方向臭氧浓度逐渐增大,臭氧浓度与电压和风速成近似线性关系。

  4. Study on producing technology of the high concentration ozone ice%高浓度臭氧冰制取技术的研究

    Institute of Scientific and Technical Information of China (English)

    刁石强; 石红; 郝淑贤; 吴燕燕; 岑剑伟

    2011-01-01

    用臭氧发生器制取高浓度臭氧气体,经高效涡旋气-水混合泵与水循环混合溶解臭氧而取得高浓度的臭氧水,然后把高浓度臭氧水持续地送入快速制冰机中制成鳞片状的臭氧冰。通过对影响制取臭氧冰浓度的臭氧气体流量、水温、混合压力、水pH和水质等条件进行研究,最终确定臭氧冰的生产工艺。实验结果表明,在水的pH为4.0,水温接近0℃,臭氧气体流量2.5L/min,混合泵出水压力0.2MPa的条件下进行循环混合,能制出高浓度的臭氧水和臭氧冰,所制得臭氧冰的臭氧浓度达16.7mg/L。%High concentration ozone,produced by ozone generator,was mixed with water by vortex pump to obtain the high concentration ozone water,and then the high concentration ozone water was inducted continuously to the fast ice-making machine,the flake ice was made.The impacts of flow rate,water temperature,mixing pressure,and water pH value and water quality were studied.The results showed that when the water pH reached 4.0,the water temperature closed to 0℃,the ozone gas flow rate was 2.5L/min,pressure of mixing pump was 0.2MPa,the high ozone concentration of water and ice could be produced,its concentration reached 16.7mg/L in the ice.

  5. 臭氧催化氧化深度处理造纸废水研究%Experimental study on advanced treatment of papermaking wastewater with catalytic ozonation

    Institute of Scientific and Technical Information of China (English)

    王群; 叶琳嫣; 宋宏艺; 杨一; 鲁金凤; 陈盈盈; 薛宬

    2012-01-01

    In order to investigate the treatment effect of the advanced oxidation processes of papermaking wastewater treatment catalytic ozonation efficiency, the experiments were carried out using ozone alone, O3/H2O2, O3/CeO2 and O3/AC technology to study UV254, COD removal and effect of the dosage of H2O2. The results indicated that ozone oxidation had better decoloration and removal effect of UV254. Under this experimental condition, the color of the wastewater was completely faded after 10 min oxidation, and the removal of UV254 was up to 58%. With increasing the dosage of H2O2 by O3/H2O2, the removal of UV254 increased only slightly, but the COD removal was decreased. Therefore, the catalytic ozonation was not required and ozone alone may achieve better results when the use of ozone for papermaking wastewater treatment.%为了考察臭氧催化氧化深度处理工艺对造纸废水的处理效果,采用臭氧单独氧化、O/H2O2、O3/CeO2及O3/AC技术,考察其对水中UV254、COD的去除效果,同时分析了H2O2投加量对O3/H2O2氧化造纸废水效果的影响.实验结果表明,臭氧氧化具有很好的脱色及氧化水中UV254的效果;在本试验条件下,原水经过臭氧氧化10 min便可以完全褪去,UV254去除率最高可达58%左右;在O3/H2O2深度处理过程中,增加H2O2投加量只是略微提高了UV254去除率,但COD去除率反而降低.所以,在臭氧氧化某些造纸废水时,并不需要采用臭氧催化氧化技术,单独臭氧氧化便可以达到较理想效果.

  6. Tropospheric ozone column retrieval from the Ozone Monitoring Instrument by means of a neural network algorithm

    Directory of Open Access Journals (Sweden)

    P. Sellitto

    2011-05-01

    Full Text Available Monitoring tropospheric ozone from space is of critical importance in order to gain more thorough knowledge on phenomena affecting air quality and the greenhouse effect. Deriving information on tropospheric ozone from UV/VIS nadir satellite spectrometers is difficult owing to the weak sensitivity of the measured radiance spectra to variations of ozone in the troposphere. Here we propose an alternative method of analysis to retrieve tropospheric ozone columns from Ozone Monitoring Instrument radiances by means of a Neural Network algorithms. An extended set of ozone sonde measurements at northern mid-latitudes has been considered as the training and test data set. The design of the algorithm is extensively discussed. Our retrievals are compared to both tropospheric ozone residuals and optimal estimation retrievals over a similar independent test data set. Results show that our algorithm has comparable accuracy with respect to both correlative methods and its performance is slightly better over a subset containing only European ozone sonde stations. Possible sources of errors are analyzed. Finally, the capabilities of our algorithm to derive information on boundary layer ozone are studied and the results critically discussed.

  7. Evaluating stomatal ozone fluxes in WRF-Chem: Comparing ozone uptake in Mediterranean ecosystems

    Science.gov (United States)

    Rydsaa, J. H.; Stordal, F.; Gerosa, G.; Finco, A.; Hodnebrog, Ø.

    2016-10-01

    The development of modelling tools for estimating stomatal uptake of surface ozone in vegetation is important for the assessment of potential damage induced due to both current and future near surface ozone concentrations. In this study, we investigate the skill in estimating ozone uptake in plants by the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) V3.6.1, with the Wesely dry deposition scheme. To validate the stomatal uptake of ozone, the model simulations were compared with field measurements of three types of Mediterranean vegetation, over seven different periods representing various meteorological conditions. Some systematic biases in modelled ozone fluxes are revealed; the lack of an explicit and time varying dependency on plants' water availability results in overestimated daytime ozone stomatal fluxes particularly in dry periods. The optimal temperature in the temperature response function is likely too low for the woody species tested here. Also, too low nighttime stomatal conductance leads to underestimation of ozone uptake during night. We demonstrate that modelled stomatal ozone flux is improved by accounting for vapor pressure deficit in the ambient air. Based on the results of the overall comparison to measured fluxes, we propose that additional improvements to the stomatal conductance parameterization should be implemented before applying the modelling system for estimating ozone doses and potential damage to vegetation.

  8. A comparative study of disinfection efficiency and regrowth control of microorganism in secondary wastewater effluent using UV, ozone, and ionizing irradiation process.

    Science.gov (United States)

    Lee, O-Mi; Kim, Hyun Young; Park, Wooshin; Kim, Tae-Hun; Yu, Seungho

    2015-09-15

    Ionizing radiation technology was suggested as an alternative method to disinfection processes, such as chlorine, UV, and ozone. Although many studies have demonstrated the effectiveness of irradiation technology for microbial disinfection, there has been a lack of information on comparison studies of disinfection techniques and a regrowth of each treatment. In the present study, an ionizing radiation was investigated to inactivate microorganisms and to determine the critical dose to prevent the regrowth. As a result, it was observed that the disinfection efficiency using ionizing radiation was not affected by the seasonal changes of wastewater characteristics, such as temperature and turbidity. In terms of bacterial regrowth after disinfection, the ionizing radiation showed a significant resistance of regrowth, whereas, on-site UV treatment is influenced by the suspended solid, temperature, or precipitation. The electric power consumption was also compared for the economic feasibility of each technique at a given value of disinfection efficiency of 90% (1-log), showing 0.12, 36.80, and 96.53 Wh/(L/day) for ionizing radiation, ozone, and UV, respectively. The ionizing radiation requires two or three orders of magnitude lower power consumption than UV and ozone. Consequently, ionizing radiation can be applied as an effective and economical alternative technique to other conventional disinfection processes. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. A comparative study of disinfection efficiency and regrowth control of microorganism in secondary wastewater effluent using UV, ozone, and ionizing irradiation process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, O-Mi [Quarantine Technology Center, Animal and Plant Quarantine Agency Plant, 175 Anyangro, Manan-Gu, Anyang-Si, Gyeonggi-Do 480-757 (Korea, Republic of); Kim, Hyun Young; Park, Wooshin; Kim, Tae-Hun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Yu, Seungho, E-mail: seunghoyu68@gmail.com [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185 (Korea, Republic of)

    2015-09-15

    Highlights: • The ionizing radiation was applied to inactivate microorganisms and the critical dose to prevent the regrowth was determined. • The seasonal variation of disinfection efficiency observed in on-site UV treatment system was influenced by suspended solid, temperature, and precipitation, whereas, stable values were observed in ionizing radiation. • The electrical power consumption for disinfection using UV and ozone requires higher energy than ionizing radiation. - Abstract: Ionizing radiation technology was suggested as an alternative method to disinfection processes, such as chlorine, UV, and ozone. Although many studies have demonstrated the effectiveness of irradiation technology for microbial disinfection, there has been a lack of information on comparison studies of disinfection techniques and a regrowth of each treatment. In the present study, an ionizing radiation was investigated to inactivate microorganisms and to determine the critical dose to prevent the regrowth. As a result, it was observed that the disinfection efficiency using ionizing radiation was not affected by the seasonal changes of wastewater characteristics, such as temperature and turbidity. In terms of bacterial regrowth after disinfection, the ionizing radiation showed a significant resistance of regrowth, whereas, on-site UV treatment is influenced by the suspended solid, temperature, or precipitation. The electric power consumption was also compared for the economic feasibility of each technique at a given value of disinfection efficiency of 90% (1-log), showing 0.12, 36.80, and 96.53 Wh/(L/day) for ionizing radiation, ozone, and UV, respectively. The ionizing radiation requires two or three orders of magnitude lower power consumption than UV and ozone. Consequently, ionizing radiation can be applied as an effective and economical alternative technique to other conventional disinfection processes.

  10. A possible mechanism of the Scandinavian ozone loss

    Institute of Scientific and Technical Information of China (English)

    邹捍; 周立波; 季崇萍; 王维; 蹇泳啸; 吴瑞欢

    2001-01-01

    Satellite data analysis shows an important Arctic ozone loss over the Scandinavia, with - 50 DU in winter, equivalent to 15% of the total ozone over this region. The study shows a possible mechanism causing the ozone loss. The North Atlantic current carries the heat energy northwards, and causes a relatively high surface temperature along the Scandinavia. The high temperature over the east of North Atlantic heats the atmosphere, induces an upward mass lifting, and therefore causes an ozone divergence near 330°K isoentropic surface, which leads to a decline in the total ozone.

  11. Ozonation of estrogenic chemicals in biologically treated sewage

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Andersen, Henrik Rasmus; Ledin, Anna

    2010-01-01

    The present study shows that ozonation of effluents from municipal wastewater treatment plants (WWTPs) is likely to be a future treatment solution to remove estrogens and xeno-estrogens. The required ozone dose and electrical energy for producing the ozone were determined in two WWTP effluents....... It is furthermore suggested that UV-absorbance is a useful parameter for online control of the ozone dose in a full scale application since the absorbance of the WWTP effluents and the remaining concentration of the estrogens and xeno-estrogens correlated well with the applied ozone dose....

  12. Study on Effect and Mechanism of Sodium Ferulate in Preventing and Treating Ozone Induced Lung Injury in Mice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To study the effect and mechanism of sodium ferulate (SF) in preventing and treating ozone (O3) induced lung oxidative injury in mice. Methods: Lung oxidative injury model mice were established by making them inhale O3. The activity of anti-oxidase and membranous microviscosity in epithelial cells in the lung of mice were determined, and the ultrastructural change of lung tissues was observed with electromicroscopy. Results: Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were reduced, while membranous lipo-microviscosity significantly increased in the pulmonary epithelial cells of model mice, revealing ultrastructural change. These abnormal changes were reversed by SF treatment, which was manifested as the significantly raised activities of SOD and GSH-Px after treatment with high and moderate doses of SF, showing a significant difference compared with those in the model group (P<0.01). Membranous lipo-microviscosity basically approached that in the control group (P>0.05); electron microscopic examination showed a basically normal morphological structure of pulmonary epithelial cells, with the change in lung injury significantly milder than that in the model group. Conclusion: O3 could induce oxidative injury of lungs in mice, and SF could enhance the anti-oxidation capacity of mice and scavenge the oxygen free radicals so as to alleviate the injury.

  13. 基于臭氧分子体系的动力学研究%Dynamics study of thesystem based on ozone molecules

    Institute of Scientific and Technical Information of China (English)

    刘松红; 任维义

    2012-01-01

    Based on the Hamiltonian derived from dynamic group and the bond angle of Ozone molecules fixed at the equilibrium one. the Poincare section and KAM torus in phase space are calculated and the energy properties are studied by solving the canonical motion equation. A lot of dynamic information of Ozone molecules is therefore obtained.%在李代数动力学群得到Hamiltonian的基础上,通过求解正则运动方程,对固定键角近似下臭氧分子体系相空间的庞加莱截面、KAM环面以及振动体系的能量属性进行了研究,获得了有关臭氧分子振动体系丰富的动力学信息.

  14. Experimental and modelling study of the effect of airflow orientation with respect to strip electrode on ozone production of surface dielectric barrier discharge

    Science.gov (United States)

    Mikeš, J.; Pekárek, S.; Soukup, I.

    2016-11-01

    This study examines the effect of airflow orientation with respect to the strip active electrode on concentration of ozone and nitrogen dioxide produced in a planar generator based on the surface dielectric barrier discharge. The orientation of the airflow was tested in parallel and perpendicular with respect to the strips. It was found that in the investigated range of average discharge power, the ozone concentration increases approximately by 25% when airflow was oriented in parallel with respect to the strips in comparison with perpendicular orientation of the airflow. Similarly the increase of nitrogen dioxide concentration was observed for parallel orientation of the airflow with respect to the strips in comparison with the perpendicular orientation of the airflow. Within the range of wavelengths from 250 to 1100 nm, the changes of intensities of spectral lines associated with airflow orientation have been observed. A 3D numerical model describing ion trajectories and airflow patterns have also been developed.

  15. Sum frequency generation and catalytic reaction studies of the removal of the organic capping agents from Pt nanoparticles by UV-ozone treatment

    Energy Technology Data Exchange (ETDEWEB)

    Aliaga, Cesar; Park, Jeong Y.; Yamada, Yusuke; Lee, Hyun Sook; Tsung, Chia-Kuang; Yang, Peidong; Somorjai, Gabor A.

    2009-12-10

    We report the structure of the organic capping layers of platinum colloid nanoparticles and their removal by UV-ozone exposure. Sum frequency generation vibrational spectroscopy (SFGVS) studies identify the carbon-hydrogen stretching modes on poly(vinylpyrrolidone) (PVP) and tetradecyl tributylammonium bromide (TTAB)-capped platinum nanoparticles. We found that the UV-ozone treatment technique effectively removes the capping layer on the basis of several analytical measurements including SFGVS, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The overall shape of the nanoparticles was preserved after the removal of capping layers, as confirmed by transmission electron microscopy (TEM). SFGVS of ethylene hydrogenation on the clean platinum nanoparticles demonstrates the existence of ethylidyne and di-{sigma}-bonded species, indicating the similarity between single-crystal and nanoparticle systems.

  16. The mechanism and pathway of the ozonation of 4-chlorophenol in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    PI; Yunzheng

    2006-01-01

    The removal efficiency of 4-chlorophenol by ozonation was studied, and the reaction mechanism and characteristic of ozonation of 4-chlorophenol were investigated. Ozone and hydroxyl radicals are two strong oxidants during the process of ozonation. The experimental results showed that when there was no scavenger to inhibit OH· radicals, an intermediate product, hydrogen peroxide was formed during the ozonation of 4-chlorophenol. Hydrogen peroxide reacted with ozone at neutral pH and produced hydroxyl radicals. Ozone at the dosage of 113 mg/L could remove 20 mg/L4-chlorophenol and 39% TOC. With the complete inhibition of hydroxyl radicals, molecular ozone could effectively destroy 4-chlorophenol to form 4-quinone, which was subsequently oxidized to formic acid and oxalic acid. Two reaction pathways of the degradation of 4-chlorophenol by ozone and O3/OH· were proposed in this study. Ozonation is an effective method for reducing 4-chlorophenol,and has potential to practical application.

  17. Sensitivity study of the inverse problem on retrieval of the altitude profile of ozone from emission intensities of the molecular oxygen in the MLT

    Science.gov (United States)

    Martyshenko, Kseniia; Yankovsky, Valentine

    2015-04-01

    Retrieval of the ozone density altitude profile is important problem for energetics of the upper atmosphere. For comparison of methods of retrieval of altitude profiles of ozone concentration from emissions of excited oxygen molecule and atom was used a modern model of electronic-vibrational kinetics of the products of O3 and O2 photolysis YM-2011 [1]. This study uses only a part of the complete model YM-2011 related to population of levels O2(b1Σ+g, v=0-2), O2(a1Δg, v=0-5) and metastable atom O(1D). Thereby, we obtained solutions of the inverse problem of [O3] retrieval from five proxies O2(a1Δg, v = 0), O2(b1Σ+g, v = 0, 1, 2) and O (1D). Theoretically, every proposed emission of excited component could be promising sources of information about [O3], because it depends on [O3] both in production and in quenching. Detailed analysis of the solutions of the inverse problem of [O3] retrieval were conducted by the sensitivity study of these levels for variations of all model parameters at altitudes of z=40-105 km. The maximum values of sensitivity coefficient to [O3] variations have the following components: O2(b1Σ+g, v = 1), O2(a1Δg, v = 0) and O(1D). The sensitivity of all excited component to variations of ozone decreases sharply above 105 km due to a drastic fall of ozone concentration. [O2(b1Σ+g, v=2)] does not depend on ozone completely at the proposed altitudes, and [O2(b1Σ+g, v=0)] has the lowest sensitivity to variations of [O3] among rest components. Based on the results of the sensitivity study authors investigated the ozone altitude profiles retrieval accuracy taking into account uncertainties of all input parameters (solar excitation and photodissociation rates, quantum yields of products and rate constants of aeronomical reactions). Uncertainties of retrieval of altitude profiles of [O3] from [O(1D)] don't exceed 10% in the interval 40-85 km were obtained. Profile of [O2(b1Σ+g, v=1] allows us to retrieval of [O3] with 21% uncertainty at z =40

  18. Eight years of stratospheric ozone observations at Marambio, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Damski, J.; Taalas, P. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research

    1995-12-31

    In this work behaviour of the stratospheric ozone using the total ozone and ozone sounding measurements from Marambio (64 deg 14`S, 56 deg 37`W) at Antarctic Peninsula has been studied. The effects of depleted stratospheric ozone to the UV-B-radiation are investigated employing a radiative transfer model, and the Marambio total ozone measurements. The levels of UV-B radiation have been studied from the point of the erythemal UV-B-doses on the horizontal human epidermis. The low values of total ozone at Marambio are also reflected to the received UV-doses which have increased roughly 20-80% (compared to long term average) during austral spring and summer. In respective to the total amount of ozone, the model calculations show that during October the UV-B-doses can be at the same level they should be during normal summer

  19. Charge-Transfer Complexes and Photochemistry of Ozone with Ferrocene and n-Butylferrocene: A UV-vis Matrix-Isolation Study.

    Science.gov (United States)

    Pinelo, Laura F; Kugel, Roger W; Ault, Bruce S

    2015-10-15

    The reactions of ozone with ferrocene (cp2Fe) and with n-butylferrocene (n-butyl cp2Fe) were studied using matrix isolation, UV-vis spectroscopy, and theoretical calculations. The codeposition of cp2Fe with O3 and of n-butyl cp2Fe with O3 into an argon matrix led to the production of 1:1 charge-transfer complexes with absorptions at 765 and 815 nm, respectively. These absorptions contribute to the green matrix color observed upon initial deposition. The charge-transfer complexes underwent photochemical reactions upon irradiation with red light (λ ≥ 600 nm). Theoretical UV-vis spectra of the charge-transfer complexes and photochemical products were calculated using TD-DFT at the B3LYP/6-311G++(d,2p) level of theory. The calculated UV-vis spectra were in good agreement with the experimental results. MO analysis of these long-wavelength transitions showed them to be n→ π* on the ozone subunit in the complex and indicated that the formation of the charge-transfer complex between ozone and cp2Fe or n-butyl cp2Fe affects how readily the π* orbital on O3 is populated when red light (λ ≥ 600 nm) is absorbed. 1:1 complexes of cp2Fe and n-butyl cp2Fe with O2 were also observed experimentally and calculated theoretically. These results support and enhance previous infrared studies of the mechanism of photooxidation of ferrocene by ozone, a reaction that has considerable significance for the formation of iron oxide thin films for a range of applications.

  20. Combined effects of ozone and other air pollutants, especially allergens; Kombinationswirkung von Ozon mit anderen Luftschadstoffen, insbesondere mit Allergenen

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, D. [Muenchen Univ. (Germany). Inst. fuer Arbeits- und Umweltmedizin; Joerres, R.; Magnussen, H. [Krankenhaus Grosshansdorf (Germany). Zentrum fuer Pneumologie und Thoraxchirurgie

    2000-07-01

    Ozone effects in humans may either be examined in epidemiological or in clinical exposure studies. In the natural environment ozone does not occur alone but only in combination with other noxious agents. The present summary gives an overview of the literature on combined effects of ozone and allergens. [German] Ozoneffekte auf den Menschen koennen zum einen in epidemiologischen, zum anderen in klinischen Expositionsstudien untersucht werden. In der natuerlichen Umwelt des Menschen tritt Ozon nicht allein auf, sondern mit anderen Noxen kombiniert. Die vorliegende Zusammenfassung ist eine Literaturuebersicht ueber die Kombinationswirkung von Ozon mit Allergenen. (orig.)

  1. A matrix-isolation-infrared spectroscopic study of the reactions of nitric oxide with oxygen and ozone

    Science.gov (United States)

    Bhatia, S. C.; Hall, J. H., Jr.

    1980-01-01

    An investigation of the oxidation of NO to NO2 by trapping the products of the gas-phase reactions with excess oxygen and ozone identified the transient species by their infrared spectra. The primary products of the NO + NO2 reactions were NO2, N2O3(A), N2O3(B), N2O4, and peroxy nitrate (OONO). The primary products of the NO + O3 reactions were NO2 and peroxy NO3 with the higher nitric oxides in low concentrations compared with the NO + O2 reactions. Isotopic oxygen and ozone were used to identify the infrared absorption frequency of the peroxy nitrate.

  2. Occurrence of ozone anomalies over cloudy areas in TOMS version-7 level-2 data

    OpenAIRE

    Liu, X.; M.J. Newchurch; Kim, J. H.

    2003-01-01

    This study investigates anomalous ozone distributions over cloudy areas in Nimbus-7 (N7) and Earth-Probe (EP) TOMS version-7 data and analyzes the causes for ozone anomaly formation. A 5°-longitude by 5°-latitude region is defined to contain a Positive Ozone Anomaly (POA) or Negative Ozone Anomaly (NOA) if the correlation coefficient between total ozone and reflectivity is > 0.5 or

  3. Assessment of ozone impacts on vegetation in southern Africa and directions for future research

    CSIR Research Space (South Africa)

    Van Tienhoven, AM

    2005-03-01

    Full Text Available in the high ozone levels measured at the beginning of the southern African summer.17,23,24 The concentrations of ozone precursors, the complex production and removal pro- cesses, and the short lifespan of ozone, mean that ozone concentration in the atmosphere... jointoformextensiveareasofchlorosisas the leaf ages. Damage to foliage can be extensive enough to cause complete loss ofleafycropssuchaslettuceandchicory.39 Visible symptoms of ozone effects must be interpreted with caution, particularly in field studies where interactions...

  4. Calha Norte: Explaining Brazilian Army Presence in the Amazon

    Science.gov (United States)

    1993-06-01

    Perimetral Norte (Northern Perimeter Rim Road) that essentially served to "fence in" the Brazilian occupied territories of the Amazon. Another move by the...Naval Postgraduate School Monterey, CA 93943 13. LT Michael B. Ryan 1604 Red Hill Rd. Dauphin, PA 17018 110

  5. Impact of Intercontinental Transport of North American Ozone on Tropospheric Ozone over East Asia

    Science.gov (United States)

    Zhu, Ye; Liu, Jane; Wang, Tijian; Zhuang, Bingliang; Han, Han; Wang, Hengmao; Chang, Yi; Ding, Ke

    2017-04-01

    Ozone is an important trace gas in the troposphere as a major pollutant and greenhouse gas. In this study, we analyzed results from a global 3-dimentional chemical transport, GEOS-Chem, which simulates ozone concentrations from different regions, tracks their transport to each of the regions and thus provides a valuable dataset to study contributions of long-range transport of ozone from different regions to East Asia. With a particular focus on the influence of North American ozone, we compared the simulations with ozonesonde measurements at two sites in USA and found the model can best capture the ozone's interannual variations in the middle and upper troposphere in the region. We also used air parcel trajectory analysis and found that North American ozone can reach the western East Asia within 4-6 days. In the middle and upper troposphere, North American ozone can influence East Asia most significantly in spring and fall. In the lower troposphere, North American ozone's influence is the largest in winter. In fall, the fractional contribution of North American ozone appears to be the largest in the lower troposphere over Europe, while in the upper troposphere it can affect most regions of Eurasia, especially above 30°N. Ozone generated from North American's boundary layer is mainly transported to the west coast of Europe with so-called warm conveyor belts associated with extratropical cyclones, and along with the westerlies to the entire northern hemisphere. It is transported to the lower troposphere with the downdraft in Europe and East Asia. The underlying mechanisms for the seasonal variation on NA ozone influences will be discussed.

  6. Ozone production in four major cities of China: sensitivity to ozone precursors and heterogeneous processes

    Directory of Open Access Journals (Sweden)

    L. K. Xue

    2013-10-01

    Full Text Available Despite a large volume of research over a number of years, our understandings of the key precursors that control tropospheric ozone production and the impacts of heterogeneous processes remain incomplete. In this study, we analyze measurements of ozone and its precursors made at rural/suburban sites downwind of four large Chinese cities – Beijing, Shanghai, Guangzhou and Lanzhou. At each site the same measurement techniques were utilized and a photochemical box model based on the Master Chemical Mechanism (v3.2 was applied, to minimize uncertainties in comparison of the results due to differences in methodology. All four cities suffered from severe ozone pollution. At the rural site of Beijing, export of the well-processed urban plumes contributed to the extremely high ozone levels (up to an hourly value of 286 ppbv, while the pollution observed at the suburban sites of Shanghai, Guangzhou and Lanzhou was characterized by intense in-situ ozone production. The major anthropogenic hydrocarbons were alkenes and aromatics in Beijing and Shanghai, aromatics in Guangzhou, and alkenes in Lanzhou. The ozone production was found to be in a VOCs-limited regime in both Shanghai and Guangzhou, and a mixed regime in Lanzhou. In Shanghai, the ozone formation was most sensitive to aromatics and alkenes, while in Guangzhou aromatics were the predominant ozone precursors. In Lanzhou, either controlling NOx or reducing emissions of olefins from the petrochemical industry would mitigate the local ozone production. The potential impacts of several heterogeneous processes on the ozone formation were assessed. The hydrolysis of dinitrogen pentoxide (N2O5, uptake of the hydroperoxyl radical (HO2 on particles, and surface reactions of NO2 forming nitrous acid (HONO present considerable sources of uncertainty in the current studies of ozone chemistry. Further efforts are urgently required to better understand these processes and refine atmospheric models.

  7. A Simple Method for Simulating Horizontal Ozone Concentration Fields over Coastal Areas: A Case Study of the Seoul Metropolitan Area, Korea

    Directory of Open Access Journals (Sweden)

    Cheol-Hee Kim

    2009-01-01

    Full Text Available This paper describes a simple semi-empirical photo chemical simulation method to generate horizontal ozone (O3 concentration fields over coastal areas. Based on a simple semi-empirical photochemical reaction model (SEGRS, consisting of a simple photochemical reaction set and a diagnostic wind model, aggregated VOC emission strength is empirically scaled from measured photochemical gas phase concentrations of (O3-2NO-NO2 against cumulative actinic light flux for the case of relatively weak off-shore geostrophic wind at 850 hPa in sum mer. This scaled emission rate for volatile organic compounds (VOCs is equally applied to horizontal O3 concentration simulation under on-shore synoptic conditions, and results are com pared with observations. The results indicate that spatial distribution patterns and temporal variations of spatially aver aged ground level ozone concentrations are reasonably well simulated. In addition, from the more than 100 box-form SEGRS simulations, close agreement between simulated and ob served daily maximum O3 concentrations suggests that the semi empirical SEGRS model has great potential in getting horizontal ozone distribution pat terns. This indicates that this simple semi-empirical approach to the simulation of O3 concentration pat terns using SEGRS makes for an easy alternative method in multi-year simulation for impact studies of O3 concentrations by lowering heavy computational cost.

  8. 含酚废水的臭氧氧化处理研究%The study of ozone oxidation of phenol wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    谢飞

    2012-01-01

    This paper to reduce ozone oxidation process with a high concentration of phenol in waste the characteristics of phenol through the study of phenol concentration in the waste water control, waste water variables, ozone variables, oxidation factors such as time and catalyst, finding out all kinds of conditions of ozone in addition to the influence law of phenol efficiency, and then shows better treatment scheme, experimental results show that reach the expected goal.%通过臭氧氧化处理,降低含有较高苯酚浓度废水中的苯酚浓度。对不同苯酚浓度的废水,用自制的设备控制废水的流量、臭氧量、氧化时间和催化剂用量,找出各种条件对臭氧除酚效率的影响规律,得出较佳处理方案。实验结果达到了预期目标。

  9. Experimetal study on monitoring ozonated water disinfection of fresh-cut fruit and vegetables by ORP%用ORP监控鲜切果蔬臭氧水消毒的实验研究

    Institute of Scientific and Technical Information of China (English)

    李尤; 刘钟阳; 都健

    2011-01-01

    研究了用氧化还原电位(ORP)监控臭氧水对鲜切果蔬的消毒灭菌过程,通过不同ORP的臭氧水消毒实验发现,将鲜切果蔬浸入ORP超过800mV的臭氧水中超过30s可以使细菌总数下降约2个数量级.通过改变臭氧浓度和水温的方法研究了臭氧水ORP的影响因素,得出了提高臭氧气体浓度和低温制冷有利于制取高ORP臭氧水的结论.结果表明,利用ORP监测臭氧水的消毒能力是可行的.%Monitoring the process of disinfection and sterilization of fresh-cut fruit and vegetables treated with ozonated water by ORP was studied.It was found that the number of total bacterial counts was reduced by the order of about 102 by immerging fresh-cut fruit and vegetables into ozonated water with ORP above 800mV over 30s through ozonated water disinfection and sterilization experiment with different values of ORP.The influence factors of ORP of ozonated water were studied by changing concentration of ozonated and water temperature.It was concluded that increasing the concentration of ozone and lowering the water temperature tend to produce ozonated water with high ORP.The study showed that it was feasible to monitor the ability of disinfection and sterilization of fresh-cut fruit and vegetables with ozonated water by ORP.

  10. The behaviour of stratospheric and upper tropospheric ozone in high and mid latitudes; the role of ozone as a climate gas

    Energy Technology Data Exchange (ETDEWEB)

    Kyroe, M.; Rummukainen, M.; Kivi, R.; Turunen, T.; Karhu, J. [Finnish Meteorological Inst., Sodankylae (Finland); Taalas, P. [Finnish Meteorological Inst., Helsinki (Finland)

    1996-12-31

    During the past few years, the dual role that ozone plays in climate change has been becoming increasingly obvious. First, continuous thinning of the ozone layer has been evident, even in the high and middle latitudes in the northern hemisphere. Secondly, ozone is also a greenhouse gas, affecting radiative transfer. Increases in tropospheric ozone have a positive forcing, whereas decreases in stratospheric ozone cause a negative forcing. During the last six years, measurements on total ozone and the vertical distribution of ozone have been performed at the Sodankylae Observatory. At Jokioinen Observatory, measurements on total ozone have been performed since 1990 and measurements on the vertical distribution of ozone since 1993. The overall project has focused on extending the national data series on total ozone and the vertical distribution of ozone. At the same time, the study has contributed to the study of interannual variability of the ozone layer. This SILMU project took part in the large-scale research activities, in addition to performing national studies. The results confirm that there has been fast chemical ozone destruction in the high latitudes in the northern hemisphere. This was particularly evident in the last two winters, 1994/95 and 1995/96. The new data also allows better trend analyses to be made on ozone in high and mid latitudes

  11. Variability of ozone near the tropopause from GASP data

    Science.gov (United States)

    Nastrom, G. D.

    1978-01-01

    The first 22 months of ozone data from the Global Atmospheric Sampling Program are summarized. Variations in space and time were examined at nearly all scales permitted by the data. Case studies in the tropics suggest that local ozone maxima may be found in or near clouds. Preliminary seasonal mean maps of ozone during spring are presented for the Northern Hemisphere. In the troposphere over the United States during summer there is a distinct midcontinental ozone maximum. There is a diurnal variation in ozone in the upper troposphere and the daily range is about 5 ppbv. Correlations between ozone and other variables are given for the synoptic-scale and on a hemispheric scale. The possible bearing of these results on ozone transport computations is discussed.

  12. Ozone Determination: A Comparison of Quantitative Analysis Methods

    Directory of Open Access Journals (Sweden)

    Rachmat Triandi Tjahjanto

    2012-10-01

    Full Text Available A comparison of ozone quantitative analysis methods by using spectrophotometric and volumetric method has been studied. The aim of this research is to determine the better method by considering the effect of reagent concentration and volume on the measured ozone concentration. Ozone which was analyzed in this research was synthesized from air, then it is used to ozonize methyl orange and potassium iodide solutions at different concentration and volume. Ozonation was held for 20 minutes with 363 mL/minutes air flow rates. The concentrations of ozonized methyl orange and potassium iodide solutions was analyzed by spectrophotometric and volumetric method, respectively. The result of this research shows that concentration and volume of reagent having an effect on the measured ozone concentration. Based on the results of both methods, it can be concluded that volumetric method is better than spectrophotometric method.

  13. Residential ozone and lung function in the elderly

    DEFF Research Database (Denmark)

    Braeuner, Elvira V.; Karottki, Dorina Gabriela; Frederiksen, Marie

    2016-01-01

    Ground level ozone arises primarily from traffic, it is a powerful oxidant and its primary target organ is the lung. Most epidemiological studies reporting the health effects of ozone have estimated individual exposure from measurements obtained from outdoor monitors but surrogates of personal...... exposure may not adequately reflect personal exposures. Also, the main focus has been on infants and children. Our purpose was to assess associations between urban background ozone and indoor residential ozone levels as well as to investigate the effects of indoor residential ozone on lung function in 51...... elderly non-smokers. Indoor ozone was measured passively in homes, while urban background outdoor ozone was monitored continuously at a fixed monitoring station located on the roof of the 20-m high university H.C. Ørsteds campus building in a park area. Lung function was measured at baseline as well...

  14. Time resolved studies of interfacial reactions of ozone with pulmonary phospholipid surfactants using field induced droplet ionization mass spectrometry.

    Science.gov (United States)

    Kim, Hugh I; Kim, Hyungjun; Shin, Young Shik; Beegle, Luther W; Goddard, William A; Heath, James R; Kanik, Isik; Beauchamp, J L

    2010-07-29

    Field induced droplet ionization mass spectrometry (FIDI-MS) comprises a soft ionization method to sample ions from the surface of microliter droplets. A pulsed electric field stretches neutral droplets until they develop dual Taylor cones, emitting streams of positively and negatively charged submicrometer droplets in opposite directions, with the desired polarity being directed into a mass spectrometer for analysis. This methodology is employed to study the heterogeneous ozonolysis of 1-palmitoyl-2-oleoyl-sn-phosphatidylglycerol (POPG) at the air-liquid interface in negative ion mode using FIDI mass spectrometry. Our results demonstrate unique characteristics of the heterogeneous reactions at the air-liquid interface. We observe the hydroxyhydroperoxide and the secondary ozonide as major products of POPG ozonolysis in the FIDI-MS spectra. These products are metastable and difficult to observe in the bulk phase, using standard electrospray ionization (ESI) for mass spectrometric analysis. We also present studies of the heterogeneous ozonolysis of a mixture of saturated and unsaturated phospholipids at the air-liquid interface. A mixture of the saturated phospholipid 1,2-dipalmitoyl-sn-phosphatidylglycerol (DPPG) and unsaturated POPG is investigated in negative ion mode using FIDI-MS while a mixture of 1,2-dipalmitoyl-sn-phosphatidylcholine (DPPC) and 1-stearoyl-2-oleoyl-sn-phosphatidylcholine (SOPC) surfactant is studied in positive ion mode. In both cases FIDI-MS shows the saturated and unsaturated pulmonary surfactants form a mixed interfacial layer. Only the unsaturated phospholipid reacts with ozone, forming products that are more hydrophilic than the saturated phospholipid. With extensive ozonolysis only the saturated phospholipid remains at the droplet surface. Combining these experimental observations with the results of computational analysis provides an improved understanding of the interfacial structure and chemistry of a surfactant layer system when

  15. Artificial ozone holes

    OpenAIRE

    Dolya, S. N.

    2014-01-01

    This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total ma...

  16. [Effects of Ozone on Photosynthesis of Several Plants].

    Science.gov (United States)

    Li, Miao-miao

    2015-05-01

    In order to investigate the effect of ozone on photosynthesis of Machilus pauhoi, Lindera setchuenensis, Phoebe bournei, Phoebe chekiangensis and Machilus thunbergii, the study was carried out in 12 open-top chambers( OTCs) with different levels of ozone in Qianyanzhou experimental station, and net photosynthesis rate (Pn) and stomatal conductance (Cond) were detected. The results indicated that ozone treatments changed the variation trend of photosynthesis of all tested plants, but ozone exposure did not always play an inhibitory role on them. In fact, photosynthesis changed with ozone concentration, experimental period, season and specific species. Exposed to ozone could even promote Pn to a peak in a short term, and the indicator of plants treated with ozone was higher than that of the control at this point. Low and medium concentrations of ozone treatment enhanced Pn of Phoebe bournei and Machilus thunbergii. The peak of treatment group also came earlier because of ozone. Furthermore, the positive correlation between Pn and Cond did not existed under the condition of ozone. Machilus thunbergii had the strongest resistance to ozone, followed by Phoebe bournei, by comparison, Phoebe chekiangensis, Machilus pauhoi and Lindera setchuenensis were more sensitive.

  17. The Use of Ozone Gas for Medical Purposes

    Directory of Open Access Journals (Sweden)

    Mehmet Ozler

    2009-02-01

    Full Text Available Ozone (O3 is a colorless and sharp odorous natural gas that is composed of three oxygen atoms. Ozone, that is toxic and pollutant near earth’s surface, it is vital in stratosphere by absorbing harmful ultraviolet radiation. Although initial years after being discovered it was used for disinfection, studies conducted have come into question for medical usage of ozone. Ozone therapy may be summarized as administering a particular amount of ozone/oxygen mixture into body cavities or circulation. Ozone/oxygen gas mixture can be applied via intravenous, intramuscular, intraarticular, intrapleural, intrarectal and intradiscal as well as topically. Most frequent ozone administration is major autohemotherapy. In this method, 50-270 ml blood of patient is taken into a special bottle and after contacting with ozone/oxygen mixture for a particular duration, it is re-infused. During this period, hydrogen peroxide produced by oxidative stress and lipid oxidations mediates the biological effects of ozone therapy by acting as a second messenger. Repetition of ozone administration creates resistance against oxidative stress via inducing antioxidative system. Moreover, levels of several cytokine are increased depending on the fatty acid oxidation in cell membranes. Ozone therapy is used as an adjuvant therapeutic modality in the pathophysiological conditions where severe inflammatory processes and immune activation are involved. Some of the examples are wound healing, age-dependent macular degeneration, ischemic and infectious disorders. [TAF Prev Med Bull 2009; 8(1.000: 69-74

  18. Model development for naphthenic acids ozonation process.

    Science.gov (United States)

    Al Jibouri, Ali Kamel H; Wu, Jiangning

    2015-02-01

    Naphthenic acids (NAs) are toxic constituents of oil sands process-affected water (OSPW) which is generated during the extraction of bitumen from oil sands. NAs consist mainly of carboxylic acids which are generally biorefractory. For the treatment of OSPW, ozonation is a very beneficial method. It can significantly reduce the concentration of NAs and it can also convert NAs from biorefractory to biodegradable. In this study, a factorial design (2(4)) was used for the ozonation of OSPW to study the influences of the operating parameters (ozone concentration, oxygen/ozone flow rate, pH, and mixing) on the removal of a model NAs in a semi-batch reactor. It was found that ozone concentration had the most significant effect on the NAs concentration compared to other parameters. An empirical model was developed to correlate the concentration of NAs with ozone concentration, oxygen/ozone flow rate, and pH. In addition, a theoretical analysis was conducted to gain the insight into the relationship between the removal of NAs and the operating parameters.

  19. Forewing venation pattern and genital plate structure in a non-outbreak population of the Rice Black Bug (Scotinophara coarctata Stål) from Lala, Lanao del Norte, Philippines

    National Research Council Canada - National Science Library

    Mark A. J. Torres; Gerald M. P. Ong; Ravindra C. Joshi; Alberto T. Barrion; Leocadio S. Sebastian; Cesar G. Demayo

    2013-01-01

    .... The present study reports on the variability in the wing venation pattern and shapes of the male and female genital plates structure in a non-outbreak population of RBB from Lala, Lanao del Norte...

  20. Ozone Improves Pain, Function and Quality of Life in Patients with Knee Osteoarthritis: A Prospective Quasi-Experimental Before-After Study

    Directory of Open Access Journals (Sweden)

    Fernández Cuadros

    2016-10-01

    Full Text Available Background The study was conducted to: 1 demonstrate the effectiveness of a treatment protocol with Ozone therapy in pain, function, and quality of life in patients with knee osteoarthritis; and 2 apply Ozone as a conservative treatment option with a demonstrable level of scientific evidence. Methods This prospective quasi-experimental before-after study was conducted on 119 patients with knee osteoarthritis, having Kellgren-Lawrence grade 2 or more, who were referred to hospital of Santa Cristina’s University, from January 2012 to April 2016. The protocol consisted of an intra-articular infiltration of a medical mixture of Oxygen-Ozone (95% - 5% 20mL, at a 20ug / mL concentration, during a total number of 4 sessions (once per week. Pain and quality of life were measured by visual analogical scale (VAS and Western Ontarion and Mc Master Universities Index for osteoarthritis (WOMAC at the beginning and end of the treatment. Results The mean age of participants was 66.29 years. The sample was composed of 70.5% Women (n = 84 and 29.5% men (n = 35. The severity of OA according to Kellgren-Lawrence scale was 2.94°. Post-puncture erythema was 8.4% (n = 10. Pain measured by VAS significantly decreased (P < 0.0001 from the score 7.89 to 2.1. The scores of WOMAC-pain, WOMAC-stiffness, and WOMAC-function subscales decreased significantly (P < 0.0001 from 15.9 to 4.4, 3.5 to 0.9, and 49.5 to 17.6, respectively. The WOMAC total score decreased from 68.9 to 22.9 (P < 0.0001. Conclusions Ozone is a safe medical treatment that can improve significantly pain relief, stiffness, and function in patients with knee osteoarthritis. The study shows a good level of evidence as well as a good grade of recommendation that allows us to consider Ozone as a conservative therapeutic option in the treatment of osteoarthritis of the knee.

  1. Effects of ozone applied by spinal endoscopy in patients with chronic pain related to failed back surgery syndrome: a pilot study

    Directory of Open Access Journals (Sweden)

    Magalhães FNO

    2013-11-01

    Full Text Available Francisco Nêuton de Oliveira Magalhães, Sandra Correia Soares, Jaqueline Melo Torres, Arthur Ungaretti, Mariana Fillipi Cacciacarro, Manoel Jacobsen Teixeira, Erich Talamoni FonoffPain Center and Division of Functional Neurosurgery, Department of Neurology, School of Medicine, University of São Paulo, São Paulo, BrazilIntroduction: In the last two decades, ozone has emerged as a treatment for low back pain, applied by means of minimally invasive techniques. Objective: The aim of this study is to assess the effect and safety of ozone therapy applied in the epidural space for chronic pain related to failed back surgery syndrome.Methods: The investigators studied 13 sequential patients of both sexes, between 18 and 70 years old, with persistent chronic pain (more than six months in the lumbar region and in the lower limbs related to failed back surgery syndrome (FBSS. Pain was classified as neuropathic and non-neuropathic regarding the topography (lumbar and lower limb, based on the DN4 questionnaire. The patients received the ozone gas in the lumbar epidural space via spinal-sacral endoscopy. Clinical evaluation was performed before, immediately after (24 hours, and 1, 3, and 6 months after intervention with visual analog scale and Oswestry Disability Index (ODI.Results: Overall, the patients had 43.7% reduction of lumbar pain, 60.9% reduction in leg pain in six months followed by 44.0% of improvement in ODI. The reduction of pain and in the disability index was markedly greater in patients with non-neuropathic predominant pain, 95.2%, 80.6%, and 75.3% improvement in lumbar, leg pain, and ODI respectively, while neuropathic predominant pain patients experienced only 12.5%, 42.4%, and 20.9% improvement, also respectively. No neurological or infectious complications were observed acutely or during the follow-up. The present data suggests that epidural ozone might be a therapeutic option for persistent low back pain, especially in non

  2. DMAH ozone measurement net

    Directory of Open Access Journals (Sweden)

    D. Pagès

    2006-01-01

    Full Text Available The complexity of the study of tropospheric ozone lies in the fact that it is a secondary pollutant. It is not emitted by a source, instead its concentration in the air depends on other compounds (especially the nitrogen oxides emitted by motor vehicles and the volatile organic compounds emitted by the industry and the vegetation and meteorological factors (especially solar radiation and temperature. The European legislation compells to make measurements of the tropospheric ozone due to its effects on people (fatigue, irritation of the mucous membranes, aggravation of asthma ... and on environment (decrease of the production of cereals, synergy with plagues .... The measuring net in Catalonia belongs to the Department of Environment and Housing (DMAH. It has a pyramidal structure and it allows a surveillance to notify in case of exceeding a certain threshold. From the registered data of last years it is shown that the number of incidences is related to meteorology. They are more frequent during afternoon and the behaviour of this pollutant is different according to the proximity of the point of measurement to the sources of its precursors.

  3. [Study on the gas-phase reaction of alpha-pinene with ozone by LP-FTIR].

    Science.gov (United States)

    Liu, Zhao-rong; Hu, Di

    2004-07-01

    The gas-phase reaction of a-pinene with ozone was tailed by LP-FTIR under 1.0 x 10(5) Pa and (296 +/- 3)K. The spectra were analyzed and a preliminary predication of the possible products was made. Then the mechanism of this reaction was extrapolated according to the IR data.

  4. A pilot plant study of the degradation of Brilliant Green dye using ozone microbubbles: mechanism and kinetics of reaction.

    Science.gov (United States)

    Khuntia, Snigdha; Majumder, Subrata Kumar; Ghosh, Pallab

    2015-01-01

    Oxidation of Brilliant Green dye was performed using ozone microbubbles in a pilot plant scale. Decolourisation was very effective at both acidic and alkaline pH. The colour of the aqueous solution was below detectable limit after 30 min at 1.7 mg/s ozone generation rate. The reaction between the dye and ozone was first-order in nature with respect to both ozone and the dye. The enhancement factor increased with increasing dye concentration. The samples were analysed by the ultra-violet-visible (UV-Vis) spectrophotometry, gas chromatography-mass spectrometry (GC-MS) and Fourier transform infra-red (FTIR) spectroscopy. From the GC-MS analysis, 13 intermediates were detected as oxidation products of this dye at various stages of oxidation. The changes in the FTIR spectra showed the destruction of the dye and the formation of new compounds. The oxidation mechanism was divided into two reaction pathways. The mineralisation of Brilliant Green was up to 80% in 60 min, as determined by total organic carbon analysis.

  5. Hydrophobic recovery of UV/ozone treated poly(dimethylsiloxane): adhesion studies by contact mechanics and mechanism of surface modification

    NARCIS (Netherlands)

    Oláh, Attila; Hillborg, Henrik; Vancso, G. Julius

    2005-01-01

    Silicone elastomers (Sylgard 184 and 170), based on poly(dimethylsiloxane) (PDMS), were surface treated by a combined exposure to UV and ozone. The effects of the treatments were analyzed as a function of time elapsed after stopping the treatments using different standard surface characterization te

  6. Nanoscale Hydrophobic Recovery: A Chemical Force Microscopy Study of UV/Ozone-Treated Cross-Linked Poly(dimethylsiloxane)

    NARCIS (Netherlands)

    Hillborg, Henrik; Tomczak, Nikodem; Oláh, Attila; Schönherr, Holger; Vancso, G. Julius

    2004-01-01

    Chemical force microscopy (CFM) in water was used to map the surface hydrophobicity of UV/ozone-treated poly(dimethylsiloxane) (PDMS; Sylgard 184) as a function of the storage/recovery time. In addition to CFM pull-off force mapping, we applied indentation mapping to probe the changes in the normali

  7. An Operational Hygiene Study for Ozone in the Cabin of the Canadian Forces (CC137) Boeing 707 Aircraft,

    Science.gov (United States)

    1982-08-01

    Biological Effects At high concentrations, ozone is a bluish gas with a characteristic pungent odour, often described as "smelling like" new mown...a sensation of irritation to the eyes within 6 minutes at a concentration of 2 - 3.7 ppm. Chronical- ly, 03 has been reported to result in bronchioli

  8. Monitoring and future projections of the Antarctic Ozone Hole using the new Ozone Mapping and Profiler Suite (OMPS)

    Science.gov (United States)

    Kramarova, N. A.; Newman, P. A.; Nash, E. R.; Bhartia, P. K.; McPeters, R. D.; Rault, D. F.; Seftor, C. J.; Xu, P.

    2013-12-01

    Using the new Ozone Mapping and Profiler Suite (OMPS), launched October 2011 on board the Suomi National Polar-orbiting Partnership satellite, we have studied the structure and evolution of the 2012 and 2013 ozone holes. The 1st ozone hole observations by OMPS began in 2012. We quality check the OMPS measurements by comparing to other satellite instruments (Aura MLS, OMI and SBUV) and ozone sonde balloon measurements. The comparisons reveal that OMPS is producing excellent Antarctic ozone hole information, and, thus, OMPS data can be used to continue the historical record of Antarctic ozone observations. In 2012 the ozone hole developed quite normally in the August to-late September 2012 period, but disappeared much more rapidly during the late-September to November period than it would be expected in a normal year. This resulted in the second weakest ozone hole observed since 1988. Some have suggested that the rapid 2012 disappearance is evidence that the Montreal Protocol is working. However, the development of the ozone hole in August and September is largely driven by chlorine and bromine from human-produced compounds, and the normal development of the ozone hole in August-September 2012 suggests that chlorine and bromine levels were roughly the same as previous years. At the same time, observations from meteorological data show that there were stronger than average weather systems, faster warming during the September -November period, and stronger vertical motions, that led to a rapid decay of the 2012 ozone hole. Hence, the weak ozone hole of 2012 is not evidence that the Montreal Protocol has impacted the ozone hole. The characteristics of the 2013 ozone hole, as observed by OMPS, will also be shown in the presentation. Model predictions suggest that the ozone hole will begin showing signs of recovery in about 2018, and it will be fully recovered back to 1980 levels in about 2065. We will update projections of the ozone hole recovery using a parametric model

  9. Evaluation of ozone profile and tropospheric ozone retrievals from GEMS and OMI spectra

    Directory of Open Access Journals (Sweden)

    J. Bak

    2012-09-01

    Full Text Available Korea is planning to launch the GEMS (Geostationary Environment Monitoring Spectrometer instrument into a Geostationary (GEO platform in 2018 to monitor tropospheric air pollutants on an hourly basis over East Asia. GEMS will measure backscattered UV radiances covering the 300–500 nm wavelength range with a spectral resolution of 0.6 nm. The main objective of this study is to evaluate ozone profiles and stratospheric column ozone amounts retrieved from simulated GEMS measurements. Ozone Monitoring Instrument (OMI Level 1B radiances, which have the spectral range 270–500 nm at spectral resolution of 0.42–0.63 nm, are used to simulate the GEMS radiances. An optimal estimation-based ozone profile algorithm is used to retrieve ozone profiles from simulated GEMS radiances. Firstly, we compare the retrieval characteristics (including averaging kernels, degrees of freedom for signal, and retrieval error derived from the 270–330 nm (OMI and 300–330 nm (GEMS wavelength ranges. This comparison shows that the effect of not using measurements below 300 nm on tropospheric ozone retrievals is insignificant. However, the stratospheric ozone information decreases greatly from OMI to GEMS, by a factor of ∼2. The number of the independent pieces of information available from GEMS measurements is estimated to 3 on average in the stratosphere, with associated retrieval errors of ∼1% in stratospheric column ozone. The difference between OMI and GEMS retrieval characteristics is apparent for retrieving ozone layers above ∼20 km, with a reduction in the sensitivity and an increase in the retrieval errors for GEMS. We further investigate whether GEMS can resolve the stratospheric ozone variation observed from high vertical resolution EOS Microwave Limb Sounder (MLS. The differences in stratospheric ozone profiles between GEMS and MLS are comparable to those between OMI and MLS above ∼3 hPa (∼40 km except with slightly larger biases and larger

  10. Modelling study of boundary-layer ozone over northern China - Part II: Responses to emission reductions during the Beijing Olympics

    Science.gov (United States)

    Tang, Guiqian; Zhu, Xiaowan; Xin, Jinyuan; Hu, Bo; Song, Tao; Sun, Yang; Wang, Lili; Wu, Fangkun; Sun, Jie; Cheng, Mengtian; Chao, Na; Li, Xin; Wang, Yuesi

    2017-09-01

    The implementation of emission reduction measures during the Olympics provided a valuable opportunity to study regional photochemical pollution over northern China. In this study, the fifth-generation Pennsylvania State University/National Centre for Atmospheric Research Mesoscale Model and Community Multiscale Air Quality model system was applied to conduct two sets of modelling analyses of the period from July 20 to September 20, 2008, to illustrate the influences of emission reduction measures on regional photochemical pollution over northern China during the Beijing Olympics. The results indicated that the implementation of emission control measures decreased the concentrations of ozone (O3) precursors, namely nitrogen oxide (NOx) and volatile organic compounds (VOCs), throughout the boundary layer. The concentrations of these compounds were reduced by 45% in the central urban area of Beijing at the ground level. Although the average O3 concentration in the central urban area increased by more than 8 ppbv, the total oxidant concentration decreased significantly by more than 5 ppbv. Greater O3 concentrations mainly occurred during periods with weak photochemical reactions. During periods of strong photochemical production, the O3 concentration decreased significantly due to a weakening vertical circulation between the lower and upper boundary layer. Consequently, the number of days when the O3 concentration exceeded 100 ppbv decreased by 25% in Beijing. The emission control measures altered the sensitivity of the regional O3 production. The coordinated control region of NOx and VOCs expanded, and the control region of VOCs decreased in size. The reduction of non-point-source emissions, such as fugitive VOCs and vehicles, was more useful for controlling regional photochemical pollution over northern China.

  11. Overview of natural gas in Rio Grande do Norte, Brazil; Panorama do gas natural no Rio Grande do Norte

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Pedro Helio Gomes [Universidade Federal do Rio Grande do Norte (GREEN/UFRN), Natal, RN (Brazil). Centro de Tecnologia. Grupo de Estudos Energeticos

    2008-07-01

    This work draws a picture of what the natural gas means to Rio Grande do Norte in its quantitative dimension, expressed in the numbers and reserve indicators, production and structure of consume. In another dimension, it broaches the processes of energetic substitution by the natural gas in the state energetic matrix. (author)

  12. Decolorization of the dye, Reactive Blue 19, using ozonation, ultrasound, and ultrasound-enhanced ozonation.

    Science.gov (United States)

    Lall, Raman; Mutharasan, Raj; Shah, Y T; Dhurjati, Prasad

    2003-01-01

    Reactive dyes constitute a significant portion of colorants used in industries ranging from the textile industry to the paper industry. In most cases, the effluent streams from textile plants are highly colored, and treatment methods for dye decolorization such as chemical oxidation need to be explored. The oxidation processes investigated in this study are those of ozonation, ultrasound, and ultrasound-enhanced ozonation. The oxidation of an anthraquinone dye was studied under conditions of varying ultrasonic power, dye concentration, ozone concentration, pH, and temperature. Laboratory experiments were performed using a semibatch reactor by ozonating dye samples with and without ultrasound. Under conditions of constant ultrasonic radiation and continuous gas application, decolorization rates have been enhanced by ultrasound. The apparent first-order rate constants increased between 35 and 204% for the ultrasonic power inputs between 40 W/L and 120 W/L compared with ozonation alone. The effects of ultrasonic power input on the gas-liquid mass-transfer coefficient were also investigated and the results indicate that an increase in ultrasonic power input increases the mass-transfer coefficient. The mass-transfer coefficient increased between 89 and 93% for ozone inlet concentrations between 5.4 and 9.4 mg/L at an ultrasonic power of 120 W/L compared with ozonation alone. The reactions of the dye with ultrasound-enhanced ozone occurred through the hydroxyl radical pathway.

  13. Power consumption analysis DBD plasma ozone generator

    Science.gov (United States)

    Nur, M.; Restiwijaya, M.; Muchlisin, Z.; Susan, I. A.; Arianto, F.; Widyanto, S. A.

    2016-11-01

    Studies on the consumption of energy by an ozone generator with various constructions electrodes of dielectric barrier discharge plasma (DBDP) reactor has been carried out. This research was done to get the configuration of the reactor, that is capable to produce high ozone concentrations with low energy consumption. BDBP reactors were constructed by spiral- cylindrical configuration, plasma ozone was generated by high voltage AC voltage up to 25 kV and maximum frequency of 23 kHz. The reactor consists of an active electrode in the form of a spiral-shaped with variation diameter Dc, and it was made by using copper wire with diameter Dw. In this research, we variated number of loops coil windings N as well as Dc and Dw. Ozone concentrations greater when the wire's diameter Dw and the diameter of the coil windings applied was greater. We found that impedance greater will minimize the concentration of ozone, in contrary to the greater capacitance will increase the concentration of ozone. The ozone concentrations increase with augmenting of power. Maximum power is effective at DBD reactor spiral-cylinder is on the Dc = 20 mm, Dw = 1.2 mm, and the number of coil windings N = 10 loops with the resulting concentration is greater than 20 ppm and it consumes energy of 177.60 watts

  14. Dobson, Brewer, ERA-40 and ERA-Interim original and merged total ozone data sets – evaluation of differences: a case study, Hradec Králové (Czech, 1961–2010

    Directory of Open Access Journals (Sweden)

    K. Vaníček

    2012-09-01

    Full Text Available Homogenized data series of total ozone measurements taken by the regularly and well calibrated Dobson and Brewer spectrophotometers at Hradec Králové (Czech and the data from the re-analyses ERA-40 and ERA-Interim were merged and compared to investigate differences between the particular data sets originated in Central Europe, the Northern Hemisphere (NH mid-latitudes. The Dobson-to-Brewer transfer function and the algorithm for approximation of the data from the re-analyses were developed, tested and applied for creation of instrumentally consistent and completed total ozone data series of the 50-yr period 1961–2010 of observations. This correction has reduced the well-known seasonal differences between Dobson and Brewer data below the 1% calibration limit of the spectrophotometers. Incorporation of the ERA-40 and ERA-Interim total ozone data on days with missing measurements significantly improved completeness and reliability of the data series mainly in the first two decades of the period concerned. Consistent behaviour of the original and corrected/merged data sets was found in the pre-ozone-hole period (1961–1985. In the post-Pinatubo (1994–2010 era the data series show seasonal differences that can introduce uncertainty in estimation of ozone recovery mainly in the winter-spring season when the effect of the Montreal Protocol and its Amendments is expected. All the data sets confirm substantial depletion of ozone also in the summer months that gives rise to the question about its origin. The merged and completed data series of total ozone will be further analyzed to quantify chemical ozone losses and contribution of natural atmospheric processes to the ozone depletion over the region. This case study points out the importance of selection and evaluation of the quality and consistency of the input data sets used in estimation of long-term ozone changes including recovery of the ozone layer over the selected areas. Data are available

  15. Dobson, Brewer, ERA-40 and ERA-Interim original and assimilated total ozone data sets – evaluation of differences: a case study, Hradec Králové (Czech, 1961–2010

    Directory of Open Access Journals (Sweden)

    K. Vaníček

    2012-05-01

    Full Text Available Homogenized data series of total ozone measurements taken by the regularly and well calibrated Dobson and Brewer spectrophotometers at Hradec Králové (Czech and the data from the re-analyses ERA-40 and ERA-Interim were assimilated and combined to investigate differences between the particular data sets over Central Europe, the NH mid-latitudes. The Dobson-to-Brewer transfer function and the algorithm for approximation of the data from the re-analyses were developed, tested and applied for creation of instrumentally consistent and completed total ozone data series of the 50-yr period 1961–2010 of observations. The assimilation has reduced the well-known seasonal differences between Dobson and Brewer data below the 1% calibration limit of the spectrophotometers. Incorporation of the ERA-40 and ERA-Interim total ozone data on days with missing measurements significantly improved completeness and reliability of the data series mainly in the first two decades of the period concerned. Consistent behaviour of the original and assimilated data sets was found in the pre-ozone-hole period (1961–1985. In the post-Pinatubo (1994–2010 era the data series show seasonal differences that can introduce uncertainty in estimation of ozone recovery mainly in the winter-spring season when the effect of the Montreal Protocol and its Amendments is expected. All the data sets confirm substantial depletion of ozone also in the summer months that gives rise to the question about its origin. The assimilated and completed data series of total ozone will be further analyzed to quantify chemical ozone losses and contribution of natural atmospheric processes to the ozone depletion over the region. This case study points out importance of selection and evaluation of the quality and consistency of the input data sets used in estimation of long-term ozone changes including recovery of the ozone layer over the selected areas. Data are available from the PANGAEA database

  16. Ozone mitigation tests at the APS

    Energy Technology Data Exchange (ETDEWEB)

    Kuzay, T.M.; Collins, J.T.; Pisharody, M.; Job, P.K.; Wang Zhibi

    1996-09-01

    Ozone is generated in the APS experimental stations whenever the x-ray beam has a chance to interact with air. Ozone concentrations in an experimental station have to be below a certain defined limit (current OSHA regulations specify 0.08 ppm as the maximum limit) before an experimenter can reenter the hutch. This limit is said to be currently under study for a downward adjustment. One method of depleting the ozone generated in an experimental station is mitigation through either adsorption or direct destruction. In recent tests, both methods were tried using commercially available units. Test results and some analytical predictions are presented.

  17. Wastewater treatment by oxidation with ozone.

    OpenAIRE

    Edna de Almeida; Márcia Regina Assalin; Maria Aparecida Rosa; Nelson Durán

    2004-01-01

    A large variety of organic and inorganic compounds may be found in wastewater which can contribute to environmental contamination. Oxidation processes with ozone (O3; O3/UV; O3/H2O2; O3/TiO2; O3/Mn+2) and the use of ozone in the pre- or post-treatment of wastewater combined with biological processes has been extensively studied for the treatment of effluents. The aim of this work was to evaluate the potential of the ozonation process in the treatment of several industrial wastewaters, namely ...

  18. Dynamical contibution of Mean Potential Vorticity pseudo-observations derived from MetOp/GOME2 Ozone data into weather forecast, a Mediterranean High Precipitation Event study.

    Science.gov (United States)

    Sbii, Siham; Zazoui, Mimoun; Semane, Noureddine

    2015-04-01

    In the absence of observations covering the upper troposphere - lower stratophere, headquarters of several disturbances, and knowing that satellites are uniquely capable of providing uniform data coverage globally, a methodology is followed [1] to convert Total Column Ozone, observed by MetOp/GOME2, into pseudo-observations of Mean Potential Vorticity (MPV). The aim is to study the dynamical impact of Ozone data in the prediction of a Mediterranean Heavy Precipitation Event observed during 28-29 September 2012 in the context of HYMEX1. This study builds on a previously described methodology [2] that generates numerical weather prediction model initial conditions from ozone data. Indeed, the assimilation of MPV in a 3D-var framework is based on a linear regression between observed Ozone and vertical integrated Ertel PV. The latter is calculated using dynamical fields from the moroccan operational limited area model ALADIN-MAROC according to [3]: δθ fp p0 -R δU δV P V = - gξaδp- g-R-(p )Cp [(δp-)2 + (δp-)2] (1) Where ξa is the vertical component of the absolute vorticity, U and V the horizontal wind components, θ the potential temperature, R gas constant, Cp specific heat at constant pressure, p the pressure, p0 a reference pressure, g the gravity and f is the Coriolis parameter. The MPV is estimated using the following expression: --1--∫ P2 M PV = P1 - P2 P P V.δp 1 (2) With P1 = 500hPa and P2 = 100hPa In the present study, the linear regression is performed over September 2012 with a correlation coefficient of 0.8265 and is described as follows: M P V = 5.314610- 2 *O3 - 13.445 (3) where O3 and MPV are given in Dobson Unit (DU) and PVU (1 PV U = 10-6 m2 K kg-1 s-1), respectively. It is found that the ozone-influenced upper-level initializing fields affect the precipitation forecast, as diagnosed by a comparison with the ECMWF model. References [1] S. Sbii, N. Semane, Y. Michel, P. Arbogast and M. Zazoui (2012). Using METOP/GOME-2 data and MSG ozone

  19. Pulse laser photolysis of aqueous ozone in the microsecond range studied by time-resolved far-ultraviolet absorption spectroscopy.

    Science.gov (United States)

    Goto, Takeyoshi; Morisawa, Yusuke; Higashi, Noboru; Ikehata, Akifumi; Ozaki, Yukihiro

    2013-05-01

    Chemical dynamics of an ozone (O3) pulse-photolytic reaction in aqueous solutions were studied with pump-probe transient far-ultraviolet (FUV) absorption spectroscopy. With a nanosecond pulse laser of 266 nm as pump light, transient spectra of O3 aqueous solutions (78-480 μM, pH 2.5-11.3) were acquired in the time range from -50 to 50 μs in the wavelength region from 190 to 225 nm. The measured transient spectra were linearly decomposed into the molar absorption coefficients and the concentration-time profiles of constituted chemical components with a multivariate curve resolution method. From the dependences of the time-averaged concentrations for 20 μs of the constituted chemicals on the initial concentration of O3, it was found that the transient spectra involve the decomposition of O3 and the formation of hydrogen peroxide (H2O2) and a third component that is assigned to hydroxyl radical (OH) or perhydroxyl radical (HO2). Furthermore, the pH dependence of the time-averaged concentration of the third components indicates that HO2 is more probable than OH as the third component. The time-averaged concentration ratio of each chemical component to the initial O3 concentration depends on the pH conditions from -0.95 to -0.60 for O3, 0.98 to 1.2 for H2O2, 0.002 to 0.29 for OH, and 0.012 to 0.069 for HO2.

  20. Studying interfacial reactions of cholesterol sulfate in an unsaturated phosphatidylglycerol layer with ozone using field induced droplet ionization mass spectrometry.

    Science.gov (United States)

    Ko, Jae Yoon; Choi, Sun Mi; Rhee, Young Min; Beauchamp, J L; Kim, Hugh I

    2012-01-01

    Field-induced droplet ionization (FIDI) is a recently developed ionization technique that can transfer ions from the surface of microliter droplets to the gas phase intact. The air-liquid interfacial reactions of cholesterol sulfate (CholSO(4)) in a 1-palmitoyl-2-oleoyl-sn-phosphatidylglycerol (POPG) surfactant layer with ozone (O(3)) are investigated using field-induced droplet ionization mass spectrometry (FIDI-MS). Time-resolved studies of interfacial ozonolysis of CholSO(4) reveal that water plays an important role in forming oxygenated products. An epoxide derivative is observed as a major product of CholSO(4) oxidation in the FIDI-MS spectrum after exposure of the droplet to O(3) for 5 s. The abundance of the epoxide product then decreases with continued O(3) exposure as the finite number of water molecules at the air-liquid interface becomes exhausted. Competitive oxidation of CholSO(4) and POPG is observed when they are present together in a lipid surfactant layer at the air-liquid interface. Competitive reactions of CholSO(4) and POPG with O(3) suggest that CholSO(4) is present with POPG as a well-mixed interfacial layer. Compared with CholSO(4) and POPG alone, the overall ozonolysis rates of both CholSO(4) and POPG are reduced in a mixed layer, suggesting the double bonds of both molecules are shielded by additional hydrocarbons from one another. Molecular dynamics simulations of a monolayer comprising POPG and CholSO(4) correlate well with experimental observations and provide a detailed picture of the interactions between CholSO(4), lipids, and water molecules in the interfacial region.

  1. Ambient Ozone Concentrations and the Risk of Perforated and Nonperforated Appendicitis: A Multicity Case-Crossover Study

    Science.gov (United States)

    Tanyingoh, Divine; Dixon, Elijah; Johnson, Markey; Wheeler, Amanda J.; Myers, Robert P.; Bertazzon, Stefania; Saini, Vineet; Madsen, Karen; Ghosh, Subrata; Villeneuve, Paul J.

    2013-01-01

    Background: Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis. Objectives: We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis. Methods: We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis. Results: Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20). Conclusions: Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis. PMID:23842601

  2. Understanding in-situ ozone production in the summertime through radical observations and modelling studies during the Clean air for London project

    Science.gov (United States)

    Whalley, Lisa; Stone, Daniel; Sharp, Thomas; Garraway, Shani; Bannan, Thomas; Percival, Carl; Hopkins, James; Holmes, Rachel; Hamilton, Jacqui; Lee, James; Laufs, Sebastian; Kleffmann, Jörg; Heard, Dwayne

    2014-05-01

    -oxidation products was considered in addition to the measured primary OH reactants. Carbonyl species such as formaldehyde, acetaldehyde and acetone have been identified as the VOC class dominating organic OH reactivity. As such, together with the direct radical source contribution by photolysis, these species dominate local ozone production in London. Modelling studies comparing the observed carbonyl concentrations with model predictions suggest that over 50% of the total concentration may be directly emitted and, hence, London's in-situ chemistry may be considered to contribute significantly to the ozone levels observed.

  3. 纯化水系统臭氧消毒方法的研究%Study of Ozone Disinfection of Purification Water System

    Institute of Scientific and Technical Information of China (English)

    韩冬; 安爱军

    2013-01-01

    Objective To study the bactericidal effect of ozone on staphylococcus aureus and disinfection ability of purified water storage tank and pipeline. Methods 0.98 mg/L ozone solution is prepared with JW-5 water treatment ozone generator, and its bactericidal effects on staphylococcus aureus and disinfection effect on purified water storage tank and pipeline are measured. The sample, which is quantification ally trained through membrane filtration-agar culture, is taken at different time to calculate sterilization rate. Results The sterilization rates of ozone solution against staphylococcus aureus in 5 min, 10 min, 30 min are 99.29%, 100%, 100%. The sterilization rates for purified water pipeline and storage tank in 10 min, 45 min and 60 min are 95.79%, 99.85% and 100%. Conclusion Ozone disinfection is an exact method in the course of purifying water system disinfection.%目的 研究臭氧对金黄色葡萄球菌的杀菌效果和对纯化水贮罐和管道的消毒能力.方法利用JW-5型水处理臭氧发生器制备浓度为0.98 mg/L的臭氧溶液,分别对金黄色葡萄球菌杀菌,对纯化水贮罐及管道消毒,在不同时间取样,经薄膜过滤-琼脂培养法定量培养,计算杀菌率.结果臭氧溶液对金葡菌作用5 min、10 min、30 min后,对金葡菌的杀菌率分别为99.29%、100%、100%;对纯化水管道和贮罐冲洗消毒10 min、45 min和60 min,杀菌率分别为95.79%、99.85%和100%.结论臭氧消毒效果确切,能满足纯化水贮罐和管道的消毒要求.

  4. Impact of intercontinental pollution transport on North American ozone air pollution: an HTAP phase 2 multi-model study

    Science.gov (United States)

    Huang, Min; Carmichael, Gregory R.; Pierce, R. Bradley; Jo, Duseong S.; Park, Rokjin J.; Flemming, Johannes; Emmons, Louisa K.; Bowman, Kevin W.; Henze, Daven K.; Davila, Yanko; Sudo, Kengo; Eiof Jonson, Jan; Tronstad Lund, Marianne; Janssens-Maenhout, Greet; Dentener, Frank J.; Keating, Terry J.; Oetjen, Hilke; Payne, Vivienne H.

    2017-05-01

    The recent update on the US National Ambient Air Quality Standards (NAAQS) of the ground-level ozone (O3) can benefit from a better understanding of its source contributions in different US regions during recent years. In the Hemispheric Transport of Air Pollution experiment phase 1 (HTAP1), various global models were used to determine the O3 source-receptor (SR) relationships among three continents in the Northern Hemisphere in 2001. In support of the HTAP phase 2 (HTAP2) experiment that studies more recent years and involves higher-resolution global models and regional models' participation, we conduct a number of regional-scale Sulfur Transport and dEposition Model (STEM) air quality base and sensitivity simulations over North America during May-June 2010. STEM's top and lateral chemical boundary conditions were downscaled from three global chemical transport models' (i.e., GEOS-Chem, RAQMS, and ECMWF C-IFS) base and sensitivity simulations in which the East Asian (EAS) anthropogenic emissions were reduced by 20 %. The mean differences between STEM surface O3 sensitivities to the emission changes and its corresponding boundary condition model's are smaller than those among its boundary condition models, in terms of the regional/period-mean (Modeling System) simulation without EAS anthropogenic emissions. The scalability of O3 sensitivities to the size of the emission perturbation is spatially varying, and the full (i.e., based on a 100 % emission reduction) source contribution obtained from linearly scaling the North American mean O3 sensitivities to a 20 % reduction in the EAS anthropogenic emissions may be underestimated by at least 10 %. The three boundary condition models' mean O3 sensitivities to the 20 % EAS emission perturbations are ˜ 8 % (May-June 2010)/˜ 11 % (2010 annual) lower than those estimated by eight global models, and the multi-model ensemble estimates are higher than the HTAP1 reported 2001 conditions. GEOS-Chem sensitivities indicate that

  5. Degradation of Phenol in Wastewater with Ozone Produced by Self-design Ozone Generator

    Directory of Open Access Journals (Sweden)

    Wang Shibo

    2016-01-01

    Full Text Available The optimized tube’s structure of the self-design ozone generator was made with the double dielectric inner electrode and small metal cones were embedded in the outside electrode. This ozone generator was used for the degradation of phenol in wastewater. The research was studied from ozone gas flow rate, reaction time, the initial pH and concentration of the phenol in wastewater. In addition, the article also discusses the reaction mechanism of ozone degraded the phenol in wastewater. The results illustrate that the ozone concentration of self-design ozone generator under the pure oxygen flux (1.0 L/min were 7.06 mg/L, compared with the unoptimized ozone, the optimized ozone generator’s efficiency was improved 56.89%; the phenol removal rate was increased as the initial pH increased in wastewater, when pH was 12, the phenol removal rate was 80.17%; GC-MS analysis was adopted to analyze and determine the phenol intermediates. The results illustrate that the major oxidation degradation products of phenol may be p-benzoquinone benzenequinone, 4-cyclopentene-1, 3-dione and diacetone alcohol.

  6. Fundamental Study on the Ozone Posttreatment of Reverse Osmosis Permeates from Army Wastewaters.

    Science.gov (United States)

    1981-03-01

    and the stripping apparatus used in this study are described later. 76 The dynamic headspace stripping technique was evaluated to study the...results in Table 27 show that this apparatus offers higher efficiency under the same stripping conditior.s. Thus, dynamic headspace stripping, even with

  7. Impact of Ozone Exposure on OPV Efficiency

    Science.gov (United States)

    Palankar, Aneeket Jaisukhlal

    Organic solar cells are a considerable promise for alternate energy sources owing to their plentiful, easily accessible and renewable source of power. Degradation on organic film and anode layer are the major factors that determine device reliability and ozone can induce damage to these materials due to its strong oxidizing property. This study measured the sustainability of a type of organic photovoltaic (OPV) film (P3HT:PC71BM) and its anodes (Al and MoO3) to different levels of ozone environment and investigated the impact of ozone exposure on OPV film and anodes efficiency. The devices were fabricated in a Glove Box under controlled N2 atmosphere using Spin Coating and Physical Vapor Deposition and exposed to varied ozone concentrations, followed by J-V measurements to determine the Power Conversion Efficiency and Fill Factor. The effects of ozone exposure on the films were compared vs. the effects of exposure on complete devices with anodes (Al and MoO 3). The results show that the devices decay from normal efficiency (4%) to 0% in 12 hours under 300 ppb (+/-10%) ozone concentration and decay to 0% in 6 hours when the ozone concentration was 600 ppb (+/-10%), when only the polymer thin films are exposed. This established an inverse linear relationship between the decay rate and ozone exposure at high concentrations on the OPV films. Furthermore, the effect of exposure to ambient ozone concentration on the polymer films, which is 70 ppb (+/-15%), was also investigated and the devices were found to decay to 0% in 28 hours, which is much faster than expected. The decay resistance of complete devices when the polymer films are coated with thermally evaporated anodes (Al and MoO3) before exposure to 400 ppb ozone concentration was investigated. The average efficiency of the complete device after 2, 6, 10, 15, 28 and 42 hours exposure in 400 ppb ozone environment was 4.16% with a standard deviation of 0.12%. The test findings for the complete device with coated

  8. The Hole in the Ozone Layer.

    Science.gov (United States)

    Hamers, Jeanne S.; Jacob, Anthony T.

    This document contains information on the hole in the ozone layer. Topics discussed include properties of ozone, ozone in the atmosphere, chlorofluorocarbons, stratospheric ozone depletion, effects of ozone depletion on life, regulation of substances that deplete the ozone layer, alternatives to CFCs and Halons, and the future of the ozone layer.…

  9. Bases para la Planeación Regional del Norte Chico: Provincias de Atacama y Coquimbo. / Basis for Region Planning of the “Norte Chico”: Atacama and Coquimbo provinces.

    Directory of Open Access Journals (Sweden)

    Guillermo Ulriksen Becker

    2008-06-01

    Full Text Available Memoria compuesta de estudios sobre la demografía, migración, estadística agrícola-ganadera-agropecuaria, sobre el carácter del comercio interior y exterior de la región, sobre la renta regional, sobre los proyectos de regadío, sobre la experiencia en sentido negativo y positivo en la realización del "Plan de Fomento y Urbanización de las Provincias de Chile" aplicado al Norte Chico y especialmente a la ciudad de la Serena, sobre la flora, etc., y, un estudio final en calidad de conclusiones./ The thesis contain studies on: demography, migration, local agriculture and livestock, local and international trade, irrigation projects, the local flora, analysis of the "Plan de Fomento y Urbanización de las Provincias de Chile" in the Norte Chico, and others; concluding with a final study with conclusions.

  10. A Kinetic Study of Ozone and Nitric Oxides in Dielectric Barrier Discharges for O2/NOx Mixtures

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A simple model is described to simulate kinetic processes in dielectric barrier discharges for O2/NOx mixtures. A threshold of ozone production found experimentally is confirmed by the calculations of this modeling, and the underlying chemical reaction mechanisms are discussed. It is also found that the effects of diffusion processes in the period of the lifetime of O atoms are not important to microdischarge channels with a large radius, i.e. larger than 150μm.

  11. Study of the anticorrelations between ozone and UV-B radiation using linear and exponential fits in Southern Brazil

    Science.gov (United States)

    Guarnieri, R.; Padilha, L.; Guarnieri, F.; Echer, E.; Makita, K.; Pinheiro, D.; Schuch, A.; Boeira, L.; Schuch, N.

    Ultraviolet radiation type B (UV-B 280-315nm) is well known by its damage to life on Earth, including the possibility of causing skin cancer in humans. However, the atmo- spheric ozone has absorption bands in this spectral radiation, reducing its incidence on Earth's surface. Therefore, the ozone amount is one of the parameters, besides clouds, aerosols, solar zenith angles, altitude, albedo, that determine the UV-B radia- tion intensity reaching the Earth's surface. The total ozone column, in Dobson Units, determined by TOMS spectrometer on board of a NASA satellite, and UV-B radiation measurements obtained by a UV-B radiometer model MS-210W (Eko Instruments) were correlated. The measurements were obtained at the Observatório Espacial do Sul - Instituto Nacional de Pesquisas Espaciais (OES/CRSPE/INPE-MCT) coordinates: Lat. 29.44oS, Long. 53.82oW. The correlations were made using UV-B measurements in fixed solar zenith angles and only days with clear sky were selected in a period from July 1999 to December 2001. Moreover, the mathematic behavior of correlation in dif- ferent angles was observed, and correlation coefficients were determined by linear and first order exponential fits. In both fits, high correlation coefficients values were ob- tained, and the difference between linear and exponential fit can be considered small.

  12. Studies on the biological effects of ozone: 8. Effects on the total antioxidant status and on interleukin-8 production

    Directory of Open Access Journals (Sweden)

    V. Bocci

    1998-01-01

    Full Text Available Ozone (O3 is a controversial gas because, owing to its potent oxidant properties, it exerts damaging effects on the respiratory tract and yet it has been used for four decades as a therapy. While the disinfectant activity of O3 is understandable, it is less clear how other biological effects can be elicited in human blood with practically no toxicity. On the other hand plasma and cells are endowed with a powerful antioxidant system so that a fairly wide range of O3 concentrations between 40 and 80μ g/ml per gram of blood (˜0.83-1.66 mM are effective but not deleterious. After blood ozonation total antioxidant status (TAS and plasma protein thiol groups (PTG decrease by 20% and 25%, respectively, while thiobarbituric acid reactive substances (TBARS increases up to fivefold. The increase of haemolysis is negligible suggesting that the erythrocyte membrane is spared at the expense of other sacrificial substrates. While there is a clear relationship between the ozone dose and IL-8 levels, we have noticed that high TAS and PTG values inhibit the cytokine production. This is in line with the current idea that hydrogen peroxide, as a byproduct of O3 decomposition, acts as a messenger for the cytokine induction.

  13. Ozone as an air pollutant

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    1996-01-01

    A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995.......A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995....

  14. Ozone as an air pollutant

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    1996-01-01

    A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995.......A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995....

  15. Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes

    Directory of Open Access Journals (Sweden)

    Massimo Fagnano

    Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based

  16. Characterizing the Vertical Processes of Ozone in Colorado's Front Range Using the GSFC Ozone DIAL

    Science.gov (United States)

    Sullivan, John T.; McGee, Thomas J.; Hoff, Raymond M.; Sumnicht, Grant; Twigg, Laurence

    2016-06-01

    Although characterizing the interactions of ozone throughout the entire troposphere are important for health and climate processes, there is a lack of routine measurements of vertical profiles within the United States. In order to monitor this lower ozone more effectively, the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center TROPospheric OZone DIfferential Absorption Lidar (GSFC TROPOZ DIAL) has been developed and validated within the Tropospheric Ozone Lidar Network (TOLNet). Two scientifically interesting ozone episodes are presented that were observed during the 2014 Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER AQ) campaign at Ft. Collins, Colorado. The first case study, occurring between 22-23 July 2014, indicates enhanced concentrations of ozone at Ft. Collins during nighttime hours, which was due to the complex recirculation of ozone within the foothills of the Rocky Mountain region. Although quantifying the ozone increase aloft during recirculation episodes has been historically difficult, results indicate that an increase of 20 - 30 ppbv of ozone at the Ft. Collins site has been attributed to this recirculation. The second case, occurring between Aug 4-8th 2014, characterizes a dynamical exchange of ozone between the stratosphere and the troposphere. This case, along with seasonal model parameters from previous years, is used to estimate the stratospheric contribution to the Rocky Mountain region. Results suggest that a large amount of stratospheric air is residing in the troposphere in the summertime near Ft. Collins, CO. The results also indicate that warmer tropopauses are correlated with an increase in stratospheric air below the tropopause in the Rocky Mountain Region.

  17. [Sterilization with ozone in health care: an integrative literature review].

    Science.gov (United States)

    Sousa, Cristina Silva; Torres, Lilian Machado; Azevedo, Marcela Padilha Facetto; de Camargo, Tamara Carolina; Graziano, Kazuko Uchikawa; Lacerda, Rúbia Aparecida; Turrini, Ruth Natalia Teresa

    2011-10-01

    The objective of this integrative literature review was to find evidence to support using ozone as a sterilizing agent for health products. The search was performed on the following bases: MEDLINE, SCOPUS, COCHRANE, COMPENDEX, INSPEC and ENGINEERING RESEARCH DATABASE; using ozone and sterilization as descriptors. Five articles were found between 1990 and 2008, which tested ozone as a sterilizer. All studies used the same type of investigation (experimental laboratory study) and achieved sterilization with ozone, but with different scopes and products, besides using different methodological procedures. Considering the ever-growing technology for new products, with the vast range of forms and materials, the findings point at ozone sterilization as a promising method, but still in an initial phase of investigation. Further experimental studies are needed to provide broader evidence regarding the possibilities and limitations of ozone sterilization.

  18. A study on the degradation of endocrine disruptors and dioxins by ozonation and advanced oxidation processes

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, S.; Kenmochi, Y.; Tutumi, K.; Tanaka, T. [Ebara Corp., Fujisawa (Japan)

    2003-07-01

    Recently, enhancement and development of treatment technologies related to contaminated water environment by endocrine disruptors such as bisphenol-A(BPA), estradiol(E2) and dioxins have become a focus of attention. In this study, the influence of O{sub 3} dosage and the forms of endocrine disruptors on the degradability during O{sub 3} treatment and AOP treatment were investigated. A reaction kinetic evaluation of these processes was also carried out. In this study, the endocrine disruptors were classified into 2 groups: (1) DXNs: dioxins and (2) EDs: endocrine disruptors other than dioxins. For the case of DXNs decomposition, highly concentrated DXNs from incinerator washwater were degraded by UV/O{sub 3} combined treatment. Influence of O{sub 3} dosage and forms of DXNs on the reaction rate constant were evaluated. For the case of EDs decomposition, the effect of O{sub 3} dosage on the reaction rate constant were investigated during O{sub 3} treatment of secondary treated sewage. Also, a degradability comparison was made for the above 2 groups. (orig.)

  19. Surface ozone in the urban area of Manaus, Amazonas, Brazil

    Science.gov (United States)

    Souza, R. A. F. D.; Costa, P. S.; Silva, C.; Godoi, R. M.; Martin, S. T.; Tota, J.; Barbosa, H. M.; Pauliquevis, T.; Ferreira De Brito, J.; Artaxo, P.; Manzi, A. O.; Wolf, S. A.; Cirino, G. G.

    2014-12-01

    When nitrogen oxides from vehicle and industrial emissions mix with volatile organic compounds from trees and plants with exposure to sunlight, a chemical reaction occurs contributing to ground-level ozone pollution. The preliminary results of the surface ozone study in urban area of Manaus, Amazonas State, Brazil, are presented for the first intensive operating period (IOP1) of the GoAmazon experiment (February/March 2014). Photochemical ozone production was found to be a regular process, with an afternoon maximum of the ozone mixing ratio of lower than 20 ppbv for cloudy days or clear sky weather. Typical ozone concentrations at mid-day were low (about 10 ppb). On the other hand, several high-value ozone episodes with surface ozone mixing ratios up to three times larger were registered during the dry season of 2013 (September/October). At the beginning of the wet season, the ozone concentration in Manaus decreased significantly, but diurnal variations can be found during the days with rainfall and other fast changes of meteorological conditions. Possible explanations of the nature of pulsations are discussed. Photochemical ozone production by local urban plumes of Manaus is named as a first possible source of the ozone concentration and biomass burning or power plant emissions are suggested as an alternative or an additional source.

  20. The activity of ozonated olive oil against Leishmania major promastigotes

    Directory of Open Access Journals (Sweden)

    Omid Rajabi

    2015-09-01

    Full Text Available Objective(s:Cutaneous Leishmaniasis is a common and endemic disease in Khorasan province in North-East of Iran. The pentavalant antimony (Sb V is the mainstay of treatment that has many side effects and resistance to the drug has been reported. The microbicidal effect of ozone was proven in different microorganisms. Since there is no study in this respect and to achieve a low cost and effective treatment, we decided to evaluate the efficacy of ozone against promastigotes of Leishmania major,in vitro. Materials and Methods: Ozonated olive oil was prepared after production of ozone by bubbling ozone-oxygen gas produced by ozone generator through olive oil until it solidified. Promastigotes of L. major were cultivated in two phasic media. After calculation of the number of promastigotes, they were incubated with ozonated olive oil (0, 0.626, 0.938, 1.25, 2.5, 5, 10 mcg/ml at 28 °c for 24 hr. Parasites survival percentage was evaluated using MTS and microscopic assay, and then compared with Glucantime and non-ozonated olive oil. Results:According to the results, there were significant differences in parasites survival percentage between ozonated olive oil and non-ozonated olive oil, at similar concentrations (P

  1. Elevation and mass change of the Echaurren Norte Glacier (Central Andes, Chile) from 1955 to 2015.

    Science.gov (United States)

    Farías, David; Vivero, Sebastián; Casassa, Gino; Seehaus, Thorsten; Braun, Matthias H.

    2017-04-01

    The Echaurren Norte Glacier (33°34'S 70°07'W) is a small mountain glacier located at the upper Maipo basin, approximately 80 km to Santiago de Chile. The glacier has the longest surface mass balance record in South America (1975 to 2016). The measurements are carried out by DGA (water directory of Chile) using the direct glaciological method. The surface mass balance show continuous negative values, but exceptional positive mass balances were identified during ENSO periods. The aim of our study is complement the in-situ observations on Echaurren Norte Glacier with the geodetic mass balance measurements for the period 1955 to 2015. Our database comprises digital elevation models (DEM) from historical cartography based on aerial photographs (1955), SRTM (2000) and Lidar data. In addition, we mapped changes in glacier extent using aerial photography and multi-mission satellite data. TanDEM-X (2012-2015) and SRTM data will be used to investigate surrounding glaciers that have not such extensive and detailed coverage as Echaurren Norte Glacier. The aerial photographs from 1955 were scanned from the original negative using a photogrammetric scanner and processed on a digital photogrammetric workstation (DPW) and georeferenced with the aid of GCPs derived from the Lidar dataset. The TanDEM-X data was processed using differential interferometry using SRTM C-band DEM as reference. Differences resulting from X- and C-band penetration are considered comparing X- and C-band SRTM data. All DEMs were laterally and vertically co-registered to each other. Error assessment was done over stable ground. Our preliminary results indicate an elevation change of -42.2 m ± 4 m (1955-2015) for Echaurren Norte Glacier. The estimated averaged annual mass balance is -0.59 m water equivalent for the period 1955-2015 using a density of 0.85 kg/cm3 for volume to mass conversion. Significant changes of the surface cover were identified, with a considerable increase of the debris cover, in

  2. Catalysts for decomposing ozone tail gas

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-an; SUN De-zhi; WANG Hui; LI Wei

    2003-01-01

    The preparation of immobilizing-catalysts for decomposing ozone by using dipping method was studied. XRD, XPS and TEM were used to characterize the catalysts. The three kinds of catalysts were selected preferentially, and their catalytic activities were investigated. The results showed that the catalyst with activated carbon dipping acetate (active components are Mn: Cu = 3:2, active component proportion in catalyst is 15%, calcination temperature is 200℃ ) has the best catalytic activity for ozone decomposing. One gram of catalyst can decompose 17.6 g ozone at initial ozone concentration of 2.5 g/m3 and the residence time in reactor of 0.1 s. The experimental results also indicated that humidity of reaction system had negative effect on catalytic activity.

  3. Impacts of increasing ozone on Indian plants.

    Science.gov (United States)

    Oksanen, E; Pandey, V; Pandey, A K; Keski-Saari, S; Kontunen-Soppela, S; Sharma, C

    2013-06-01

    Increasing anthropogenic and biogenic emissions of precursor compounds have led to high tropospheric ozone concentrations in India particularly in Indo-Gangetic Plains, which is the most fertile and cultivated area of this rapidly developing country. Current ozone risk models, based on European and North American data, provide inaccurate estimations for crop losses in India. During the past decade, several ozone experiments have been conducted with the most important Indian crop species (e.g. wheat, rice, mustard, mung bean). Experimental work started in natural field conditions around Varanasi area in early 2000's, and the use of open top chambers and EDU (ethylene diurea) applications has now facilitated more advanced studies e.g. for intra-species sensitivity screening and mechanisms of tolerance. In this review, we identify and discuss the most important gaps of knowledge and future needs of action, e.g. more systematic nationwide monitoring for precursor and ozone formation over Indian region.

  4. Study of total column atmospheric aerosol optical depth, ozone and precipitable water content over Bay of Bengal during BOBMEX-99

    Indian Academy of Sciences (India)

    K K Dani; R S Maheskumar; P C S Devara

    2003-06-01

    The spatial and temporal variations in aerosols and precursor gases over oceanic regions have special importance in the estimation of radiative forcing parameters and thereby in the refinement of general circulation models. Extensive observations of the columnar aerosol optical depth (AOD), total column ozone (TCO) and precipitable water content (PWC) have been carried out using the on-line, multi-band solar radiometers onboard ORV Sagar Kanya (Cruise#SK 147B) over Bay of Bengal during 11th-28th August 1999. Aerosol optical and physical properties (optical depth and angstrom parameter) have been estimated at six wavelengths covering from UV to NIR (380-1020 nm) while TCO and PWC have been determined using the UV band around 300nm and NIR band around 940 nm, respectively. Added, concurrent meteorological and satellite observations during this field phase of BOBMEX-99 have been utilized to investigate spectral-temporal variations of AOD, TCO and PWC in marine environment. The results indicate lower AODs (around 0.4 at characteristic wavelength of 500 nm) and size distributions with abundance of coarse-mode particles as compared to those aerosols of typical land origin. An interesting result that is found in the present study is the significant reduction in AOD at all wavelengths from initial to later part of observation period due to cloud-scavenging and rain-washout effects as well as signature of coastal aerosol loading. The clear-sky daytime diurnal variation of TCO shows gradual increase during post-sunrise hours, broad maximum during afternoon hours and gradual decrease during pre-sunset hours, which is considered to be due to photochemical reactions. The diurnal variation curve of PWC showed maximum (∼4cm) during morning hours and gradual decrease (∼3.5cm) towards evening hours, which are found to be greater as compared to typical values over land. Another interesting feature observed is that although the PWC values are very high, there was no proportionate

  5. Characterization of atmospheric oxidants during, and after 2014 APEC summit: a case study of peroxides and ozone

    Science.gov (United States)

    Shen, H.; Chen, Z.; Huang, L.

    2016-12-01

    Peroxides and ozone (O3) are important atmospheric oxidants, and are directly related to the cycling of radicals in the atmosphere. They have a profound impact on many critical atmospheric chemical processes, and are closely associated with regional air pollution and global climate change. Many filed measurements have been conducted to study their concentrations, budget, and roles in the atmospheric chemistry in the past few decades. However, the characteristic and influencing factors of concentrations of peroxides and O3 are still not fully understood, especially in the polluted area. In this study, measurements for atmospheric peroxides and O3 were conducted simultaneously at PKU site in Beijing, China during, and after the 2014 Asia-Pacific Economic Cooperation (APEC) summit when strict pollution control measures were deployed. Hydrogen peroxide (H2O2) was the predominant peroxide observed, and occasionally, hydroxylmethyl hydroperoxide (HMHP) was detected. The average concentrations of H2O2 and O3 were 22.6±23.7pptv and 14.8±13.4ppbv, respectively. Both H2O2 and O3 showed distinct diurnal variations, with a peak between 14:00-16:00 for O3, and 18:00-20:00 for H2O2. However, the emergence of the H2O2 peak shifted to the night further both during, and after APEC compared to summer observations at the same site and in clean areas, but the exact mechanism is not clear. Concentrations of H2O2 and O3 were higher during APEC with A (After APEC)/D (During APEC) ratios of 0.3 and 0.7, respectively, contrary to the changes of most of the other observed trace constituents. We discussed the influencing factors in detail, and confirmed that the reduction of NOx was the decisive factors. Additionally, we found a sudden increase of concentrations of H2O2 and O3 on the early morning of 11 November. By analyzing the changes of related meteorological parameters, backward air mass trajectories, and pressure vertical velocity, we ascribed this to the downward transport of air

  6. Lima Norte: Desarrollo con identidad en una comunidad histórica del Perú actual. El rol de la iglesia.

    Directory of Open Access Journals (Sweden)

    José Antonio Benito Rodríguez

    2014-02-01

    Full Text Available In the vertiginous development that is currently experiencing the territory of Lima Norte, the Catholic Church can be identified as a leading agent, which, since the days of the Viceroyalty and the Republic, has always accompanied the population to achieve comprehensive development. Here and now, it is confirmed as part of its program of new evangelization, an effort to promote the development of "every man and all men" of the territory under study - diocese of Carabayllo and Lima Norte- in an world opened to the globalization without losing their identity.

  7. Modelos de asentamiento en la sierra norte de Soria

    Directory of Open Access Journals (Sweden)

    Manuel CORRAL CAÑÓN

    2009-10-01

    Full Text Available En esta comunicación intentaremos una aproximación a las estructuras económicas y los modelos de asentamiento de los poblados de la Edad del Hierro en la Sierra norte de Soria. Nuestra intención es reconocer las diferencias entre los asentamientos del Hierro I y II, tanto en lo que refiere a las posibilidades del entorno, como a los esquemas de organización de los habitats.

  8. Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States.

    Science.gov (United States)

    Tong, Daniel Q; Muller, Nicholas Z; Kan, Haidong; Mendelsohn, Robert O

    2009-11-01

    Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space.

  9. Aerosol effects on ozone concentrations in Beijing: A model sensitivity study

    Institute of Scientific and Technical Information of China (English)

    Jun Xu; Yuanhang Zhang; Shaoqing Zheng; Youjiang He

    2012-01-01

    Most previous O3 simulations were based only on gaseous phase photochemistry.However,some aerosol-related processes,namely,heterogeneous reactions occurring on the aerosol surface and photolysis rate alternated by aerosol radiative influence,may affect O3 photochemistry under high aerosol loads.A three-dimensional air quality model,Models-3/Community Multi-scale Air Quality-Model of Aerosol Dynamics,Reaction,Ionization,and Dissolution,was employed to simulate the effects of the above-mentioned processes on O3 formation under typical high O3 episodes in Beijing during summer.Five heterogeneous reactions,i.e.,NO2,NO3,N2O5,HO2,and O3,were individually investigated to elucidate their effects on O3 formation.The results showed that the heterogeneous reactions significantly affected O3 formation in the urban plume.NO2 heterogeneous reaction increased O3 to 90 ppb,while HO2 heterogeneous reaction decreased O3 to 33 ppb.In addition,O3 heterogeneous loss decreased O3 to 31 ppb.The effects of NO2,NO3,and N2O5 heterogeneous reactions showed opposite O3 concentration changes between the urban and extra-urban areas because of the response of the reactions to the two types of O3 formation regimes.When the aerosol radiative influence was included,the photolysis rate decreased and O3 decreased significantly to 73 ppb O3.The two aerosol-related processes should be considered in the study of O3 formation because high aerosol concentration is a ubiquitous phenomenon that affects the urban- and regional air quality in China.

  10. Ozone Treatment for Chronic Anal Fistula: It Is Not Promising.

    Science.gov (United States)

    Ozturk, Alaattin; Atalay, Talha; Cipe, Gokhan; Luleci, Nurettin

    2017-08-01

    The aim of this study is to assess the effect of ozone gas in the treatment of anorectal fistulae. The tip of a 20 G intravenous cannula was inserted from the fistula orifice. Medical ozone was introduced into the fistula. A total of 10 sessions of ozone gas insufflation was performed on alternate days. Treatment was considered to be successful if fistula discharge ceased and the outer fistula orifice closed; however, if discharge was continued or outer fistula orifice was open, the treatment considered to be failed. A total of 12 adult patients were included in the study. The fistula was closed in three patients (25 %), in nine patients (75 %) without closure. In one patient who had fistula closure, the fistula recurred after 2 months. Patients did not express any discomfort during ozone insufflation. There were no side effects or complications due to ozone insufflation. The success rate of ozone insufflation in anorectal fistulae closure is low.

  11. OZONE ABSORPTION IN RAW WATERS

    Directory of Open Access Journals (Sweden)

    LJILJANA TAKIĆ

    2008-03-01

    Full Text Available The ozone absorption in raw water entering the main ozonization step at the Belgrade drinking water supply plant was investigated in a continuous stirred tank reactor (CSTR. A slow chemical reaction rate of dissolved ozone and pollutants present in raw water have been experimentally determined. The modified Hatta number was defined and calculated as a criterion which determines whether and to which extent the reactions of ozone and pollutants influence the rate of the pure physical ozone absorption.

  12. The Ozone Hole -- a Mystery Reborn?

    Science.gov (United States)

    von Hobe, M.; Grooß, J.; Müller, R.; Stroh, F.

    2007-12-01

    In 1985, Farman et al. discovered the near complete disappearance of the stratospheric ozone layer over Antarctica in spring. This 'Ozone Hole' took the atmospheric research community by surprise as it could not be explained by the known catalytic cycles removing ozone in the stratosphere. McElroy et al. (1986) and Molina and Molina (1987) seemed to have solved the enigma by proposing two new catalytic cycles -- the ClO-BrO-cycle and the ClO dimer cycle -- that could rapidly destroy ozone at cold temperatures and high zenith angles. Subsequent work describing the kinetics of these cycles as well as stratospheric observations of chlorine and bromine compounds supported their theory and led to atmospheric chemistry models reproducing observed ozone loss reasonably well. Today, more than 20 years after the discovery of the ozone hole and the ratification of the Montreal Protocol, a new laboratory study (Pope et al., 2007) -- suggesting much smaller absorption cross sections and hence photolysis rates of the ClO dimer -- seriously calls into question our understanding of how ozone is destroyed in the spring polar stratosphere. With the new cross sections, both the dimer cycle and the ClO-BrO-cycle run much slower, and observations of neither chlorine compounds nor ozone loss are reproduced by model simulations (von Hobe et al., 2007): the known catalytic cycles cannot cause an ozone hole. Obviously, this also calls into question our ability to predict future polar ozone depletion. In search for an explanation, we discuss possible shortcomings of the Pope et al. experiment that could lead to an underestimation of the dimer absorption and examine various new chemical processes for their likelihood to influence chlorine partitioning and cause significant ozone loss in the atmosphere and at the same time go undetected in laboratory based kinetic studies. A strategy is presented for designing the tests needed to unambiguously confirm or rule out proposed solutions to the

  13. Ozone - plant surface reactions an important ozone loss term?

    Science.gov (United States)

    Hansel, Armin; Jud, Werner; Fischer, Lukas; Canaval, Eva; Wohlfahrt, Georg; Tissier, Alain

    2015-04-01

    Elevated tropospheric ozone concentrations are considered a toxic threat to plants responsible for global crop losses with associated economic costs of several billions dollar per year. Plant injuries have been related to the uptake of ozone through stomatal pores and oxidative effects damaging the internal leaf tissue. But a striking question remains: How much ozone enters the plant through open stomata and how much ozone is lost by chemical reactions at the plant surface? Until now surface losses are estimated from measured total ozone deposition fluxes and calculated stomatal conductance values. While stomatal conductance of CO2 and H2O is well understood and extensively used in describing plant atmosphere gas exchange, stomatal conductance of ozone is not well known. Here we use different Nicotiana tabacum varieties and find that surface reactions of ozone with diterpenoids synthesized by glandular trichomes reduce ozone flux through open stomata. Our measurements reveal that fast ozone loss at the plant surface is accompanied with prompt release of oxygenated volatile compounds. In the ozone fumigation experiments of different Nicotiana tabacum varieties the release of specific volatile oxy-VOCs allowed to identify the semi volatile precursor compounds at the plant surface. Ozone fumigation experiments with Norway spruce (Picea abies) and Scots Pine (Pinus sylvestris), two common species in the Northern Hemisphere, show also a significant ozone loss at the plant surface for Picea abies. Fluid dynamic calculations of ozone transport in the diffusive leaf boundary layer reveal a vertical but no horizontal ozone gradient thus reducing ozone fluxes through the pores in case of efficient ozone scavenging plant surfaces. We explain this efficient ozone protection mechanism by the porous surface architecture of plants in combination with unsaturated semi-volatile compounds deposited at the plant surface. These results show that unsaturated semi-volatile compounds at

  14. Ozone, greenhouse effect. Ozone, effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Aviam, A.M.; Arthaut, R.

    1992-12-01

    This file is made of eight general papers on environment (climates under observation, research on photo-oxidizing pollution, scientific aspects of stratospheric ozone layer, urban engineering and environment, glory of public gardens, earths not very natural, darwinism and society, economical data on environment). (A.B.). refs., 3 tabs.

  15. Ozone and caries: a review of the literature.

    Science.gov (United States)

    Burke, F J Trevor

    2012-05-01

    Ozone, either in gaseous form or as ozonated water, has been available for use as a treatment for dental caries for a decade. This paper reviews the literature on the subject by examining the findings of publications in the peer review literature. Eighteen papers were identified by a literature search. From the review of these, it was concluded that, while some laboratory studies and some short duration clinical studies have suggested that ozone may be effective in the treatment of root caries or killing of oral micro-organisms, the clinical evidence for the use of ozone in treatment of caries is not compelling.

  16. Innovation of Ozone Initial Concentration and Boundary Condition for Models-3 Community Multi-scale Air Quality (CMAQ) Modeling System Using Ozone Climatology and Its Impacts

    Science.gov (United States)

    He, S.; Vukovich, F. M.; Ching, J.; Gilliland, A.

    2002-05-01

    Models-3/CMAQ system is designed to provide a comprehensive and flexible modeling tool for states and other government agencies, and for scientific studies. The current setting of initial concentrations and boundary condition (ICBC) of air species for CMAQ system represents clean ambient condition in the eastern-half of the US, and as such. The ozone ICBC differed from observational values, significantly at upper troposphere. Because of the stratosphere-troposphere exchange, the upper troposphere may contain high concentrations of ozone (hundreds of ppbv). However the current ICBC artificially set ozone level as 70ppbv in upper troposphere throughout model domain. The large difference of standard ozone ICBC from realistic situation becomes considerable uncertainty source of CMAQ system. The purpose of this research is to improve ICBC setting for Models-3/CMAQ modeling system, and to assess the influence of introducing stratospheric ozone into troposphere on regional and urban air quality and on the tropospheric ozone budget. The approach taken is to perform a series of sensitivity studies on ICBC with CMAQ. The simulation covers the entire US with 108km grid resolution from July 2 to 12 of 1988. The domain divide in 34 layers vertically up to 40mbar. In addition to the base case with standard ICBC, ozone initial concentration and boundary condition are generated based on ozone climatology (Logan, 1999), which was derived from surface, satellite, and ozonesonde data across the globe. This new ICBC enables CMAQ model to study ozone cross-tropopause flux transporting to lower troposphere, and to analyze the impact of intercontinental ozone transport. The tropospheric ozone residue (TOR) data is used to compare with modeling tropospheric ozone budget for evaluation of CMAQ performance. Since ozone climatology was based on observation, the derived ozone ICBC are in better agreement with the ``real'' atmosphere than standard ICBC. CMAQ simulations with ozone climatology

  17. Artificial ozone holes

    CERN Document Server

    Dolya, S N

    2014-01-01

    This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

  18. Determination of β haplotypes in patients with sickle-cell anemia in the state of Rio Grande do Norte, Brazil.

    Science.gov (United States)

    Cabral, Cynthia Hatsue Kitayama; Serafim, Edvis Santos Soares; de Medeiros, Waleska Rayane Dantas Bezerra; de Medeiros Fernandes, Thales Allyrio Araújo; Kimura, Elza Miyuki; Costa, Fernando Ferreira; de Fátima Sonati, Maria; Rebecchi, Ivanise Marina Moretti; de Medeiros, Tereza Maria Dantas

    2011-07-01

    β(S) haplotypes were studied in 47 non-related patients with sickle-cell anemia from the state of Rio Grande do Norte, Brazil. Molecular analysis was conducted by PCR/RFLP using restriction endonucleases XmnI, HindIII, HincII and HinfI to analyze six polymorphic sites from the beta cluster. Twenty-seven patients (57.5%) were identified with genotype CAR/CAR, 9 (19.1%) CAR/BEN, 6 (12.8%) CAR/CAM, 1 (2.1%) BEN/BEN, 2 (4.3%) CAR/Atp, 1 (2.1%) BEN/Atp and 1 (2.1%) with genotype Atp/Atp. The greater frequency of Cameroon haplotypes compared to other Brazilian states suggests the existence of a peculiarity of African origin in the state of Rio Grande do Norte.

  19. Effect of greenhouse gas emissions on stratospheric ozone depletion

    OpenAIRE

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric interaction. We studied the interactions in the atmosphere between the greenhouse effect and stratospheric ozone depletion from the point of view of past and future emissions of the anthropogenic com...

  20. Relationship Between Outdoor and Indoor Ozone Pollution Concentration

    Institute of Scientific and Technical Information of China (English)

    DU Xiaogang; LIU Junjie

    2009-01-01

    This paper analyses the changing rule of indoor ozone concentration and its influencing factors. A for-mula of indoor-outdoor concentration ratio(I/O ratio)was deduced based on the indoor ozone mass-balance equa-tion. The ozone I/O ratio in different kinds of buildings was studied. Results show that I/O ratio is much related to air-exchange rate, which is well compatible with the theoretical calculation results.

  1. Effect of greenhouse gas emissions on stratospheric ozone depletion

    OpenAIRE

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric interaction. We studied the interactions in the atmosphere between the greenhouse effect and stratospheric ozone depletion from the point of view of past and future emissions of the anthropogenic com...

  2. Ozone therapy in the management and prevention of caries.

    Science.gov (United States)

    Almaz, Merve Erkmen; Sönmez, Işıl Şaroğlu

    2015-01-01

    The purpose of this article was to assess the effectiveness of ozone therapy in the management and prevention of caries, reviewing clinical and in vitro studies. Ozone has proven to be effective against gram-negative and gram-positive bacteria, viruses, and fungi. In dentistry, most of the published articles are based on ozone's antimicrobial effects and the treatment of caries. Most of the clinical studies reported ozone to be a promising alternative to conventional methods for caries management. However, a few studies have shown ozone to be insufficient for preventing caries and reducing microorganisms in open occlusal carious lesions. Ozone might be a useful tool to reduce and control oral infectious microorganisms in dental plaque and dental cavity. However, the results of in vitro studies are controversial; while some researchers reported that ozone therapy had a minimal or no effect on the viability of microorganisms, others suggested ozone to be highly effective in killing both gram-positive and gram-negative oral microorganisms. Therefore, more evidence is required before ozone can be accepted as an alternative to present methods for the management and prevention of caries.

  3. Evaluation of the potential of ozone as a power plant biocide

    Energy Technology Data Exchange (ETDEWEB)

    Mattice, J.S.; Trabalka, J.R.; Adams, S.M.; Faust, R.A.; Jolley, R.L.

    1978-09-01

    A review of the literature on the chemistry and biological effects of ozone was conducted to evaluate the potential of ozone to function as a power plant biocide. Evaluation of this potential is dependent upon determining the ability of ozone to maintain the integrity of both the condenser cooling system and the associated ecosystem. The well-known bactericidal capacity of ozone and the limited biofouling control studies conducted thus far suggest that ozone can control both slime and macroinvertebrate fouling at power plants. However, full-scale demonstrations of the minimum levels of ozone required and of solution of the practical aspects of application have not been performed.

  4. Evidence of the mid-latitude impact of Antarctic ozone depletion

    Science.gov (United States)

    Atkinson, Roger J.; Matthews, W. Andrew; Newman, Paul A.; Plumb, R. Alan

    1989-01-01

    Record low ozone values found over Australia and New Zealand during December 1987 following the record low Antarctic values of October 1987 are analyzed. The sudden decline of ozone amounts in midmonth rule out photochemical effects as a cause and permit the underlying processes to be investigated on a case study basis. Using data from ozone sondes, radiosondes, the Nimbus-7 total ozone mapping spectrometer, and meteorological analyses from the National Meteorological Center, it is argued that these low values resulted from transport of ozone-poor air from higher latitudes. Thus, it seems that the chemical destruction of ozone over Antarctica in early spring is having an impact on lower latitudes.

  5. Ozonation Systems as a Non-Chemical Alternative for Stored Grain Protection

    OpenAIRE

    2013-01-01

    The use of ozone as a non-chemical alternative in stored grain protection was studied by conducting scale-up demonstrations using a fixed bed ozonation system and developing a semi-continuous counterflow and a continuous flow ozonation treatment system. The objectives of this research were to determine the efficacy of ozonation to control insect pests without affecting end-use quality; to prove the concept of the semi-continuous counterflow ozonation system to ozonate grain at a faster rate a...

  6. Antarctic springtime ozone depletion computed from temperature observations

    Science.gov (United States)

    Rosenfield, Joan E.; Schoeberl, Mark R.; Newman, Paul A.

    1988-01-01

    An observationally based, mechanistic dynamical model is used to simulate the decline of total ozone during September and October for the years 1979 through 1986. Vertical velocities derived from observed stratospheric temperature changes and computed radiative heating rates are used to advect an ozone mixing ratio profile during the Antarctic spring period. An early August 1982 Syowa balloonsonde ozone profile is used to initialize the computations. The model reasonably simulates the September and October changes in total ozone, considering the uncertainties in the observed data and the radiative heating. The simulated decline is found to be very sensitive to the choice of initial ozone profile and to small changes in the radiative heating. The results of this study suggest that the dynamical hypothesis of the Antarctic ozone depletion is both quantitatively credible and consistent with the observed temperature changes.

  7. USE OF GASEOUS OZONE AS A DISINFECTANT IN MEAT INDUSTRY

    Directory of Open Access Journals (Sweden)

    S. Stella

    2013-02-01

    Full Text Available The aim of this study was to investigate the possible use of gaseous ozone as a disinfectant for meat industry environments. Firstly microbial inactivation trials were conducted in laboratory conditions on Petri plates inoculated with some microorganisms of importance to the food industry. The treatment with 1 ppm of ozone resulted to be effective in 1 h on the strains in use. Then similar trials were conducted in a meat industry, 1 ppm of ozone was supplied for 3 h. The results confirmed the antimicrobial efficacy of ozone even if it was less active than in laboratory conditions. A different sensibility among the microorganisms was observed, the most resistant being P. fluorescens and B. thuringiensis. Our results confirm the suitability of gaseous ozone as a disinfectant for meat industry environments and underline the need to calibrate ozone treatment parameters on the real environmental conditions of work-room.

  8. Three-dimensional model study of the arctic ozone loss in 2002/2003 and comparison with 1999/2000 and 2003/2004

    Directory of Open Access Journals (Sweden)

    W. Feng

    2004-09-01

    Full Text Available We have used the SLIMCAT 3-D off-line chemical transport model (CTM to quantify the Arctic chemical ozone loss in the year 2002/2003 and compare it with similar calculations for the winters 1999/2000 and 2003/2004. Recent changes to the CTM have improved the model's ability to reproduce polar chemical and dynamical processes. The updated CTM uses σ-θ as a vertical coordinate which allows it to extend down to the surface. The CTM has a detailed stratospheric chemistry scheme and now includes a simple NAT-based denitrification scheme in the stratosphere.

    In the model runs presented here the model was forced by ECMWF ERA40 and operational analyses. The model used 24 levels extending from the surface to ~55 km and a horizontal resolution of either 7.5°×7.5° or 2.8°×2.8°. Two different radiation schemes, MIDRAD and the CCM scheme, were used to diagnose the vertical motion in the stratosphere. Based on tracer observations from balloons and aircraft, the more sophisticated CCM scheme gives a better representation of the vertical transport in this model which includes the troposphere. The higher resolution model generally produces larger chemical O3 depletion, which agrees better with observations.

    The CTM results show that very early chemical ozone loss occurred in December 2002 due to extremely low temperatures and early chlorine activation in the lower stratosphere. Thus, chemical loss in this winter started earlier than in the other two winters studied here. In 2002/2003 the local polar ozone loss in the lower stratosphere was ~40% before the stratospheric final warming. Larger ozone loss occurred in the cold year 1999/2000 which had a persistently cold and stable vortex during most of the winter. For this winter the current model, at a resolution of 2.8°×2.8°, can reproduce the observed loss of over 70% locally. In the warm and more disturbed winter 2003/2004 the chemical O3 loss was generally

  9. Three-dimensional model study of the Arctic ozone loss in 2002/2003 and comparison with 1999/2000 and 2003/2004

    Directory of Open Access Journals (Sweden)

    W. Feng

    2005-01-01

    Full Text Available We have used the SLIMCAT 3-D off-line chemical transport model (CTM to quantify the Arctic chemical ozone loss in the year 2002/2003 and compare it with similar calculations for the winters 1999/2000 and 2003/2004. Recent changes to the CTM have improved the model's ability to reproduce polar chemical and dynamical processes. The updated CTM uses σ-θ as a vertical coordinate which allows it to extend down to the surface. The CTM has a detailed stratospheric chemistry scheme and now includes a simple NAT-based denitrification scheme in the stratosphere. In the model runs presented here the model was forced by ECMWF ERA40 and operational analyses. The model used 24 levels extending from the surface to ~55km and a horizontal resolution of either 7.5° x 7.5° or 2.8° x 2.8°. Two different radiation schemes, MIDRAD and the CCM scheme, were used to diagnose the vertical motion in the stratosphere. Based on tracer observations from balloons and aircraft, the more sophisticated CCM scheme gives a better representation of the vertical transport in this model which includes the troposphere. The higher resolution model generally produces larger chemical O3 depletion, which agrees better with observations. The CTM results show that very early chemical ozone loss occurred in December 2002 due to extremely low temperatures and early chlorine activation in the lower stratosphere. Thus, chemical loss in this winter started earlier than in the other two winters studied here. In 2002/2003 the local polar ozone loss in the lower stratosphere was ~40% before the stratospheric final warming. Larger ozone loss occurred in the cold year 1999/2000 which had a persistently cold and stable vortex during most of the winter. For this winter the current model, at a resolution of 2.8° x 2.8°, can reproduce the observed loss of over 70% locally. In the warm and more disturbed winter 2003/2004 the chemical O3 loss was generally much smaller, except above 620K where

  10. Three-dimensional model study of the Arctic ozone loss in 2002/2003 and comparison with 1999/2000 and 2003/2004

    Science.gov (United States)

    Feng, W.; Chipperfield, M. P.; Davies, S.; Sen, B.; Toon, G.; Blavier, J. F.; Webster, C. R.; Volk, C. M.; Ulanovsky, A.; Ravegnani, F.; von der Gathen, P.; Jost, H.; Richard, E. C.; Claude, H.

    2005-01-01

    We have used the SLIMCAT 3-D off-line chemical transport model (CTM) to quantify the Arctic chemical ozone loss in the year 2002/2003 and compare it with similar calculations for the winters 1999/2000 and 2003/2004. Recent changes to the CTM have improved the model's ability to reproduce polar chemical and dynamical processes. The updated CTM uses σ-θ as a vertical coordinate which allows it to extend down to the surface. The CTM has a detailed stratospheric chemistry scheme and now includes a simple NAT-based denitrification scheme in the stratosphere. In the model runs presented here the model was forced by ECMWF ERA40 and operational analyses. The model used 24 levels extending from the surface to ~55km and a horizontal resolution of either 7.5° x 7.5° or 2.8° x 2.8°. Two different radiation schemes, MIDRAD and the CCM scheme, were used to diagnose the vertical motion in the stratosphere. Based on tracer observations from balloons and aircraft, the more sophisticated CCM scheme gives a better representation of the vertical transport in this model which includes the troposphere. The higher resolution model generally produces larger chemical O3 depletion, which agrees better with observations. The CTM results show that very early chemical ozone loss occurred in December 2002 due to extremely low temperatures and early chlorine activation in the lower stratosphere. Thus, chemical loss in this winter started earlier than in the other two winters studied here. In 2002/2003 the local polar ozone loss in the lower stratosphere was ~40% before the stratospheric final warming. Larger ozone loss occurred in the cold year 1999/2000 which had a persistently cold and stable vortex during most of the winter. For this winter the current model, at a resolution of 2.8° x 2.8°, can reproduce the observed loss of over 70% locally. In the warm and more disturbed winter 2003/2004 the chemical O3 loss was generally much smaller, except above 620K where large losses occurred

  11. Clinical aplications of ozone in Dentistry

    Directory of Open Access Journals (Sweden)

    Haroldo José Mendes

    2009-01-01

    Full Text Available The ozone is an allotropic form of oxygen whose unique properties offer a wide application to biological systems and clinical treatments. Although discovered in the year 1840, its clinical use is current, finding applicability in various specialties in the dentistry pratice. This article aims to review the clinical applications of ozone in various dental specialties. The compound provides a high purifying capacity, responsible for microbicides actions (bacteria, fungi and viruses, through oxidation mechanisms not yet elucidated, makes it an alternative against the diseases. In dentistry practice, the ozone can be employed in process of sterilization of instruments and purification system of irrigation to dental unit, serving as a good strategy in the control and prevention of cross-infection in the dental environment. However, the administration of ozone at low concentration by systemic way induces tissue proliferation and neovascularization, and thus inducing a healing, a characteristic that makes it attractive from the clinical, as it allows both the elimination of bacteria such as the repair of anatomical structures. It has limited use in treating endodontic infections and tooth decay. The ozone can be used in the treatment of various oral diseases, reducing the clinical course of disease, achieving superior results in comparison to conventional therapies. Despite the literature showing positive results with the use of ozone in cariology, surgery, periodontics and endodontics, there is need for further studies with standardized methodologies to reach a definitive conclusion about its applicability

  12. Activated Sludge Ozonation to Reduce Sludge Production in MBR

    Institute of Scientific and Technical Information of China (English)

    HE Sheng-bing; XUE Gang; WANG Bao-zhen

    2005-01-01

    The total experimental period was divided into two stages.At the first stage, a series of batch studies were carried out to get an understanding of the effect of ozonation on sludge properties. At the following stages, three MBRs with different amounts of activated sludge to be ozonated were run in parallel for a long period to evaluate the influence of sludge ozonation on sludge yield and permeate quality.Through batch study, it was found that ozone could disrupt the cell walls and caused the release of plasm from the cells,then the amounts of soluble organics in the solution increased with ozonation time. With the rise of soluble organics, the amount of soluble organics to be mineralized increased as well, which wonld reduce the soluble organics content. For the counteraction between these two aspects, a pseudo-balance could be achieved, and soluble organics would vary in a limited range. Sludge ozonation also increased the contents of nitrogen and phosphorus in the solution. In addition, ozonation was effective in improving sludge settling property. On the basis of batch study, a suitable ozone dosage of 0.16 kgO3/kgMLSS wasdetermined. Three systems were run in parallel for a total period of 39 days, it was demonstrated that a part of activated sludge ozonation could reduce sludge production significantly, and biological performance of mineralization and nitrification would not be inhibited due to sludge ozonation. Experimental results proved that the combination of ozonation unit with MBR unit could achieve an excellent quality of permeate as well as a small quantity of sludge production, and economic analysis indicated that an additional ozonation operating cost for treatment of both wastewater and sludge was only 0.096Yuan (US $0.011,5)/m3 wastewater.

  13. Avaliação da degradação das terras nas regiões oeste e norte da cidade de Campina Grande, PB: um estudo de caso Evaluation of land degradation in north and western regions of Campina Grande, PB: a case study

    Directory of Open Access Journals (Sweden)

    João M. de Moraes Neto

    2002-04-01

    Full Text Available Objetivou-se, com o presente trabalho, avaliar a degradação das terras nas regiões oeste e norte da cidade de Campina Grande, PB, cuja metodologia incluiu: processamento digital de imagem, interpretação visual e correlação com os dados de campo. Na análise digital utilizou-se o método de classificação supervisionada por Maximoverossimilhança (Maxver, cujos resultados se mostraram satisfatórios permitindo, assim, o mapeamento das principais áreas degradadas da região de estudo.The objective of the present work was to evaluate and characterize the land degradation in western and northern regions of Campina Grande, PB. Data were obtained through digital image processing, followed by visual interpretation of the digitally processed image and final field checking. The Gaussian Maximum Likelihood Classifier was used in digital analysis. The results of the classification showed to be satisfactory, allowing to map the main degraded areas of the studied region.

  14. Pb-Pb Dating mono zircon from Gloria Norte Massif, Sergipano belt; Datacao de Pb-Pb em monozircao do Macico Gloria Norte, faixa Sergipana

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa, V.A.C.; Rosa, M.L.S.; Conceicao, H., E-mail: viniciuslisboa1@hotmail.com [Pós-Graduacão em Geociências e Análise de Bacias/Universidade Federal de Sergipe, São Cristóvão, SE (Brazil); Macambira, M.J.B.; Galarza, M.A. [Pós-Graduacão em Geociências/Universidade Federal do Pará, Belem, PA (Brazil); Rios, D.C. [Departamento de Geologia/Universidade Federal da Bahia, Salvador, BA (Brazil)

    2014-11-01

    The Gloria Norte Massif (MGN) has about 50 km{sup 2} in area, lies between the cities of Nossa Senhora da Gloria and Monte Alegre, northeastern Sergipe state, is composed of monzonitic rocks, being intrusive in metasediments Domain Macurure, in the Sergipano Belt. In this study Pb-Pb geochronological determinations were performed using the evaporation technique single crystals of zircon in MGN. Two samples were analyzed (03A and 12A) and the results were ages of 646 ± 2.5 Ma and 650 ± 4.5 Ma, place this magmatism in the Cryogenian period. These data may imply that around 645-655 Ma, there was an active magmatic arc in this region of the Sergipano Belt. (author)

  15. Formation of ozone and growth of aerosols in young smoke plumes from biomass burning: 1. Lagrangian parcel studies

    Science.gov (United States)

    Alvarado, Matthew James; Prinn, Ronald G.

    2009-05-01

    We have developed a new model of the gas- and aerosol-phase chemistry of biomass burning smoke plumes called Aerosol Simulation Program (ASP). Here we use ASP combined with a Lagrangian parcel model to simulate the chemistry in smoke plumes from three fires: the Otavi savannah fire in Namibia, an Alaska boreal forest fire, and the Timbavati savannah fire. Our model explained the observations of ozone in the Otavi and Alaska plumes fairly well, but our initial model simulation of the Timbavati plume underestimated the concentrations of ozone, OH, and secondary aerosol matter. The Timbavati simulation agrees with observations if we increase OH to equal its observed levels. Heterogeneous reactions of NO2 and SO2 could explain the needed higher concentrations of OH and the rapid formation of ozone, nitrate, and sulfate in the smoke plume if the uptake coefficients on smoke aerosols are large (O(10-3) and O(10-4), respectively). Uncharacterized organic species in the smoke plume were likely responsible for the rapid formation of aerosol organic carbon. The changes in the aerosol size distribution were dominated by plume dilution and condensational growth. The single scattering albedo of the modeled smoke increases from 0.866 to 0.902 over 1 h of aging. The change in aerosol scattering with relative humidity for the modeled fresh smoke matches observations up to 66% RH, but the model greatly overestimates the humidification factor at 80% RH (2.88 versus an observed value of 1.70-1.79). For the aged smoke, the modeled humidification factor is 1.22, slightly below the observed value of 1.40.

  16. Influence of pH and ozone dose on sulfaquinoxaline ozonation.

    Science.gov (United States)

    Urbano, Vanessa Ribeiro; Maniero, Milena Guedes; Pérez-Moya, Montserrat; Guimarães, José Roberto

    2016-08-21

    Sulfaquinoxaline (SQX) is an antimicrobial of the sulfonamides class. Usually employed in veterinary medicine, this contaminant of emerging concern has been found in superficial and groundwater and its consequences for the environment and human health are not completely known. In this study, SQX (C0 = 500 μg L(-1), 1 L) degradation by an ozonation process at pH 3, 7, and 11 was evaluated. Ozonation was effective in degrading SQX: efficiency exceeding 99% was obtained applying an ozone dose of 2.8 mg L(-1) at pH 3. Assays were performed according to a 2(2) design of experiments (DOE) with star points and three central points for statistical validity. Minimum and maximum levels were set at 3 and 11 for pH, and 0 and 11.5 mg L(-1) for applied ozone dose. There was no significant interaction between these variables, and the pH value played the most important role in terms of contaminant degradation. In relation to toxicity, samples ozonated at pH 3 did not inhibit the luminescence of the bacteria, even though different intermediates were formed and identified by mass spectra. At pH 7, inhibition of luminescence remained almost constant (at around 30%) according to ozonation time or ozone dose. However, the hydroxyl radical, the major oxidant at pH 11, was responsible for the formation of toxic intermediates.

  17. On the "ozone deficit problem": what are Ox and HOx catalytic cycles for ozone depletion hiding?

    Science.gov (United States)

    Varandas, António J C

    2002-05-17

    Studies on the role of vibrational excitation in the reactants for the O2 + O2, OH + O2, and HO2 + O2 reactions show that they can be important sources of ozone in the stratosphere, particularly at conditions of local thermodynamic disequilibrium. The results suggest that the Ox and HOx cycles commonly viewed as catalytic sinks of ozone may actually lead to its production, and hence help to clarify the "ozone deficit problem". This paper also presents an explanation for the general overestimation of the OH abundance in the upper stratosphere and lower mesosphere through standard HOx chemistry.

  18. An observational retrospective/horizontal study to compare oxygen-ozone therapy and/or global postural re-education in complicated chronic low back pain.

    Science.gov (United States)

    Apuzzo, Dario; Giotti, Chiara; Pasqualetti, Patrizio; Ferrazza, Paolo; Soldati, Paola; Zucco, Gesualdo M

    2014-01-01

    Acute low back pain (LBP) is the fifth most common reason for physician visits and about nine out of ten adults experience back pain at some point in their life. In a large number of patients LBP is associated with disc herniation (DH). Recently, oxygen-ozone (O2O3) therapy has been used successfully in the treatment of LBP, reducing pain after the failure of other conservative treatments. The aim of this study was to assess the effects of O2O3 therapy in back pain rehabilitation, comparing three groups of patients suffering from chronic back pain associated with DH submitted to three different treatments: intramuscular O2O3 infiltrations, global postural An observational retrospective/horizontal study to compare oxygen-ozone therapy and/or global postural re-education in complicated chronic low back pain re-education (GPR), or a combination of the two (O2O3+GPR). The data show that pain severity before treatment was significantly lower in the patients treated with GPR alone (VAS score 7.4) than in the O2O3+GPR patients (VAS score 8.5) and the O2O3 patients (VAS score 8.6). At the end of treatment, pain severity was lower in the O2O3 patients than in the GPR-alone patients. After some years of follow-up only the difference between O2O3+GPR and GPR-alone remained significant.

  19. Tropospheric Ozone Profile Information Derived From "Cloud Slicing"

    Science.gov (United States)

    Ziemke, Jerald R.; Chandra, S.; Bhartia, P. K.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    This study introduces a new approach to obtain ozone vertical profile information given coincident satellite measurements of both cloud-top pressure and above-cloud column ozone. This method is denoted "cloud slicing". In this study information of cloud-top pressure is derived from Geostationary Orbital Earth Satellite (GOES) infrared data, while above-cloud column ozone is obtained from the Earth Probe total ozone mapping spectrometer (TOMS) instrument. Several case examples are presented showing the feasibility of this technique as well as providing new geophysical results. Because the TOMS instrument measures backscattered UV radiation, it does detect ozone lying below dense water vapor clouds. This opaque property of TOMS can be used directly in conjunction with co-located cloud-top pressure data to derive ozone profile information in the troposphere. The cloud slicing method is an extension of the "Convective Cloud Differential" (CCD) method. In the CCD method, tropospheric column ozone (i.e., the total vertical column of ozone lying in the troposphere) is computed by taking total column ozone with low reflectivity (R less than 0.2) and subtracting from this a nearby measurement of above-cloud column ozone amount under conditions of high reflectivity (R greater than 0.9). (High reflectivity away from snow/ice conditions coincides with strong convection and tropopause-level clouds). The key element in determining tropospheric ozone profile information from the cloud slicing method is to have simultaneous and co-located measurements of both above-cloud column ozone and cloud-top pressure.

  20. Synergistic effect of sequential or combined use of ozone and UV radiation for the disinfection of Bacillus subtilis spores.

    Science.gov (United States)

    Jung, Yeon Jung; Oh, Byung Soo; Kang, Joon-Wun

    2008-03-01

    This study was performed to evaluate the inactivation efficiency or synergy of combined ozone and UV processes (combined ozone/UV process) or sequential processes (ozone-UV, UV-ozone) compared with individual unit processes and to investigate the specific roles of ozone, UV and the hydroxyl radical, which is formed as an intermediate in the combined ozone/UV process. The Bacillus subtilis spore, which has often been used as a surrogate microorganism for Cryptosporidium parvum oocysts, was used as a target microorganism. Compared to individual unit processes with ozone or UV, the inactivation of B. subtilis spores by the combined ozone/UV process was enhanced under identical conditions. To investigate the specific roles of ozone and UV in the combined ozone/UV process, sequential ozone-UV and UV-ozone processes were tested for degrees of inactivation. Additionally, the experiment was performed in the presence and absence of tert-butyl alcohol, which acted as a hydroxyl radical scavenger to assess the role of inactivation by the hydroxyl radical in the combined ozone/UV process. Among the five candidate processes, the greatest synergistic effect was observed in the combined ozone/UV process. From the comparison of five candidate processes, the hydroxyl radical and ozone were each determined to significantly enhance the overall inactivation efficiency in the combined ozone/UV process.

  1. Addressing Ozone Layer Depletion

    Science.gov (United States)

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  2. 2001 Ozone Design Value

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the...

  3. Susceptibility to mass movement processes in the municipality of Tlatlauquitepec, Sierra Norte de Puebla

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Borja Baeza

    2011-02-01

    Full Text Available Since historical times, mass movement processes have taken place in the Mexican territory as a result of its topography, heterogeneous lithology, intense rainfall and the impact of anthropic activity, particularly in mountainous areas such as the Sierra Norte de Puebla. In this region, as a result of extremely high rainfall, a large number of landslides occurred in October 1999. These were mainly slides and flows; they affected economic, structural and environmental aspects and caused the loss of dozens of human lives. Among the various approaches to analysis of this type of hazard, cartography is of considerable importance since it allows the understanding and assessment of spatial distribution, as well as of the interactions of elements of the terrain that determine slope instability. Hence, some studies of landslide hazard cartography have been carried out in Mexico; these have mainly been based on the overlaying, against a background of geographic information systems, of layers of information concerning the parameters that are involved in slope instability. However, there is a tendency for this approach to establish similar degrees of influence for all factors, regardless of specific local conditions. The present aim was to consider the influence of the five most important parameters controlling regional slope instability in the Sierra Norte de Puebla (slope, morphogenesis, relief dissection, deforestation and roads, and to validate the results by means of a recurrence index. Multicriteria analysis has allowed a map of susceptibility to mass movement processes to be produced for the municipality of Tlatlauquitepec.

  4. Preliminary Report on the Anurans of Mount Hilong-hilong, Agusan Del Norte, Eastern Mindanao, Philippines

    Institute of Scientific and Technical Information of China (English)

    Jeszianlenn L. PLAZA; Marites B.SANGUILA

    2015-01-01

    Mount Hilong-hilong is a key biodiversity area, spanning several municipalities in the provinces of the Caraga Region (Agusan del Norte, Agusan del Sur, Surigao del Norte and Surigao del Sur), northeastern Mindanao Island, southern Philippines. The Hilong-hilong massif remains one of the most signiifcant forested areas in Mindanao, threatened with habitat modification (forest removal, degradation) and other anthropogenic disturbances related to renewable resource extraction. Amphibians are key indicator species for environmental quality and are useful focal taxa for conservation efforts. Relying on historical museum database information and new survey work on Mount Hilong-hilong, we provide species accounts and describe microhabitat preferences of the anurans (frogs and toads) present in the area. Twenty-seven species representing seven anuran families were studied in detail at elevations between 700 to 1300 meters above sea level; 16 of these species are Mindanao faunal region endemics. Qualitative overlap in microhabitat use was observed, suggesting that, for the species recorded, intact forest may ensure species persistence to some levels of anthropogenic disturbance. A more extensive herpetofaunal survey is needed to fully estimate the herpetofaunal diversity of Mount Hilong-hilong. Because amphibians represent ifne-scale indicators of environmental quality and microendemism, we recommend appropriate ifne-scaled regional strategies geared towards the conservation of amphibians in the Caraga area, northeast Mindanao Island.

  5. Effects of ozone on the sporulation, germination, and pathogenicity of Botrytis cinerea

    Energy Technology Data Exchange (ETDEWEB)

    Krause, C.R.; Weidensaul, T.C.

    1978-02-01

    Studies were initiated to determine if Botrytis cinerea conidia remain viable when grown in vivo and in vitro in the presence of ambient ozone levels and whether ozonized conidia retain pathogenicity. Experimental materials and methods used are described.

  6. COMPRESSOR TYPE OZONATOR

    Directory of Open Access Journals (Sweden)

    Gulyaev P. V.

    2016-05-01

    Full Text Available The article is devoted to the development of a compressor type ozonator. It describes the design of a high-productivity compressor ozone generator, which can be used for industrial decontamination of mixed feeds, water, milk, and in the system of presowing treatment of seeds. This construction allows generating ozone with high concentration to 5 g/m3 at high feed air or oxygen from the compressor station (up to 2000 l/min. The article describes the design of the basic elements of tubular ozone generator, examines the factors influencing the productivity of the ozonator. The proposed mathematical model allows calculating the productivity of the ozonator when considering multiple influencing factors. These factors take into account: the parameters of supply voltage, such as the magnitude and frequency of the supply voltage; the configuration and geometrical parameters of electrodes such as, the area of the electrodes, the configuration of the surface of the electrodes and distance between electrodes; parameters dielectric barrier; and the transported gas parameters such as volume, temperature, pressure and composition. Special attention is paid to the design of the electrodes made of woven wire mesh with mesh sizes from 1.5×1.5 to 2.0×2.0 mm. It is noted, that such electrodes allow obtaining the maximum productivity of an ozonator, and they do not lead to overheating of the dielectric barrier, and do not output down the generator. In the same way, the article presents the results of the mathematical modeling of ozone generator productivity while changing various factors

  7. Model Simulations of Ozone in the Summer Lower Stratosphere

    Science.gov (United States)

    Douglass, Anne R.; Kawa, S. R.

    1998-01-01

    The Goddard 3D chemistry and transport model (CTM) uses winds and temperatures from the Goddard Earth Observing System Data Assimilation System (GEOS DAS); thus CTM simulations can be compared directly with observations from satellite, balloon and aircraft. In general, aspects of these comparisons show remarkable agreement between observation and model. One significant difference is that the model ozone is high biased below the ozone peak. The bias is apparently largest at high latitudes during the summer months. At the same time, comparisons with HALOE observations show that at mid to high latitudes, the ozone mixing ratio peak appears persistently at a lower altitude than observed by HALOE; the peak mixing ratio is also overestimated by the model. Both transport and photochemistry are possible contributors to the biased ozone in the lower stratosphere - excessive downward motion would increase lower stratospheric ozone, as would a too large vertical gradient in ozone. On the other hand, comparisons of model N2O and NOy with observations suggest transport deficiencies in the opposite sense, i.e., model N2O can be high relative to observations (particularly during winter), suggesting the need for stronger downward transport. Sensitivity studies have been carried out using parameterizations for ozone production and loss, NOy production and loss, and N2O loss. The goal of these studies is to clarify how problems in the photochemical scheme at and above the ozone peak influence the lower stratospheric ozone.

  8. Removal of Ozone by Carbon Nanotubes/Quartz Fiber Film.

    Science.gov (United States)

    Yang, Shen; Nie, Jingqi; Wei, Fei; Yang, Xudong

    2016-09-01

    Ozone is recognized as a harmful gaseous pollutant, which can lead to severe human health problems. In this study, carbon nanotubes (CNTs) were tested as a new approach for ozone removal. The CNTs/quartz fiber film was fabricated through growth of CNTs upon pure quartz fiber using chemical vapor deposition method. Ozone conversion efficiency of the CNTs/quartz fiber film was tested for 10 h and compared with that of quartz film, activated carbon (AC), and a potassium iodide (KI) solution under the same conditions. The pressure resistance of these materials under different airflow rates was also measured. The results showed that the CNTs/quartz fiber film had better ozone conversion efficiency but also higher pressure resistance than AC and the KI solution of the same weight. The ozone removal performance of the CNTs/quartz fiber film was comparable with AC at 20 times more weight. The CNTs played a dominant role in ozone removal by the CNTs/quartz fiber film. Its high ozone conversion efficiency, lightweight and free-standing properties make the CNTs/quartz fiber film applicable to ozone removal. Further investigation should be focused on reducing pressure resistance and studying the CNT mechanism for removing ozone.

  9. Total ozone columns and vertical ozone profiles above Kiev in 2005-2008

    OpenAIRE

    Shavrina, A. V.; Kroon, M.; Sheminova, V. A.; Pavlenko, Ya. V.; Veles, A. A.; Synyavski, I. I.; Romanyuk, Ya. O.

    2010-01-01

    The study of total ozone columns above Kiev and variations of ozone concentrations in the troposphere at different altitudes above Kiev was carried out using ground-based Fourier Transform InfraRed (FTIR) spectrometric observations that are taken on a routine basis at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (MAO NASU). This study was performed within the framework of the international ESA-NIVR-KNMI OMI-AO project no.2907 entitled OMI validation by grou...

  10. An Autonomous Ozone Instrument for Atmospheric Measurements from Ocean Buoys

    Science.gov (United States)

    Hintsa, E. J.; Rawlins, W. T.; Sholkovitz, E. R.; Hosom, D. S.; Allsup, G. P.; Purcell, M. J.; Scott, D. R.; Mulhall, P.

    2002-05-01

    Tropospheric ozone is an oxidant, a greenhouse gas, and a pollutant. Because of its adverse health effects, there are numerous monitoring stations on land but none over the oceans. We have built an ozone instrument for deployment anywhere at sea from ocean buoys, to study ozone chemistry over the oceans, intercontinental transport of pollution, diurnal and seasonal cycles of ozone, and to make baseline and long-term time series measurements of ozone in remote locations. The instrument uses direct (Beer's Law) absorption of UV radiation in a dual-path cell, with ambient and ozone-free air alternately switched between the two paths, to measure ozone. Ozone can be measured at a rate of 1 Hz, with a precision of about 1 ppb at sea level. The air inlet and outlet have valves which close automatically under high wind conditions or rain to protect the ozone sensor. The instrument has been packaged for deployment at sea, and tested on a 3-meter discus buoy with other instruments in coastal waters in fall 2001. It can operate autonomously or be controlled via line-of-sight modem or a satellite link. We will present the details of the instrument, and laboratory and buoy test data from its first deployment, including a comparison with a nearby ozone monitoring station on land. We will also present an evaluation of the instrument's performance and describe plans for improvements. In summer 2002, the ozone measurement system will be operated at the Martha's Vineyard Coastal Observatory; in the future we anticipate deploying on the Bermuda Testbed Mooring, followed by use on the open ocean to measure long-range transport of ozone.

  11. OMI total column ozone: extending the long term data record

    Science.gov (United States)

    McPeters, R. D.; Frith, S.; Labow, G. J.

    2015-07-01

    The ozone data record from the Ozone Monitoring Instrument (OMI) onboard the NASA EOS-Aura satellite has proven to be very stable over the ten plus years of operation. The OMI total column ozone processed through the TOMS ozone retrieval algorithm (version 8.5) has been compared with ground based measurements and with ozone from a series of SBUV/2 instruments. Comparison with an ensemble of Brewer and Dobson sites shows an absolute offset of about 1.5 % but stability over the ten years to better than half a percent. Comparison with a merged ozone (MOD) data set created by combining data from a series of SBUV/2 instruments again shows an offset, of about 1 %, and a relative trend of less than half a percent over ten years. The offset is mostly due to the use of the old Bass and Paur ozone cross sections in the OMI retrievals rather than the Brion/Daumont/Malicet cross sections that are now recommended. The bias in the Southern Hemisphere is smaller than that in the Northern Hemisphere, 1 vs. 1.5 %, for reasons that are not completely understood. When OMI was compared with the European realization of a multi-instrument ozone time series, the GTO (GOME type ozone) dataset, there was a small trend of about -0.85 % decade-1. Since all the comparisons of OMI relative to other ozone measuring systems show relative trends that are less than 1 % decade-1, we conclude that the OMI total column ozone data are sufficiently stable that they can be used in studies of ozone trends.

  12. OMI total column ozone: extending the long term data record

    Directory of Open Access Journals (Sweden)

    R. D. McPeters

    2015-07-01

    Full Text Available The ozone data record from the Ozone Monitoring Instrument (OMI onboard the NASA EOS-Aura satellite has proven to be very stable over the ten plus years of operation. The OMI total column ozone processed through the TOMS ozone retrieval algorithm (version 8.5 has been compared with ground based measurements and with ozone from a series of SBUV/2 instruments. Comparison with an ensemble of Brewer and Dobson sites shows an absolute offset of about 1.5 % but stability over the ten years to better than half a percent. Comparison with a merged ozone (MOD data set created by combining data from a series of SBUV/2 instruments again shows an offset, of about 1 %, and a relative trend of less than half a percent over ten years. The offset is mostly due to the use of the old Bass and Paur ozone cross sections in the OMI retrievals rather than the Brion/Daumont/Malicet cross sections that are now recommended. The bias in the Southern Hemisphere is smaller than that in the Northern Hemisphere, 1 vs. 1.5 %, for reasons that are not completely understood. When OMI was compared with the European realization of a multi-instrument ozone time series, the GTO (GOME type ozone dataset, there was a small trend of about −0.85 % decade−1. Since all the comparisons of OMI relative to other ozone measuring systems show relative trends that are less than 1 % decade−1, we conclude that the OMI total column ozone data are sufficiently stable that they can be used in studies of ozone trends.

  13. Influence of ozone on cold acclimation in sugar maple seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, A. [Agriculture and Agri-Food Canada, Sainte-Foy, PQ (Canada) Research Station; Robitaille, G. [Natural Resources Canada, Ste. Foy, PQ (Canada) Canadian Forest Service; Nadeau, P.; Castonguay, Y. [Agriculture and Agri-Food Canada, Sainte-Foy, PQ (Canada) Research Station

    1999-07-01

    A study was carried out with the aim of determining: a) if exposure to ozone gas induces changes in the key parts of cold acclimation in maple seedlings; and b) if the putative changes effect the process of cold acclimation. Two year old seedlings were exposed to two concentrations of ozone, ambient ozone (low ozone), and threefold ambient ozone concentrations (high ozone) from June to September. During the fall, winter and spring, the seedlings were left outdoors to acclimate to natural winter conditions. The freezing tolerance of stems and root tissues was determined for high ozone and low ozone treated seedlings over the winter period. Concomitant determination of the concentrations of starch, sucrose, raffinose, and stachyose in the sugar maple roots as well as ABA concentration in the xylem sap were carried out to assess the molecular changes associated with the cold acclimation of seedlings in the two treatments. Exposure to high concentrations of ozone did not decrease the freezing tolerance of sugar maple roots and improved the freezing tolerance of the stems in the fall. During the period of cold acclimation, an eightfold increase in sucrose concentration occurred in roots and stems, while starch concentration decreased. In roots, the accumulation of soluble sugars coincided with the period of lowest soil temperature. This showed that temperature has a major influence on the amount of sugar formed and the degree of freezing tolerance. There were no ozone treatment effects on either starch hydrolysis or sucrose accumulation in roots. Sucrose is a membrane and protein stabilizer during winter drying. In roots, the concentrations of the galactose containing oligosaccharides, raffinose and stachyose, were higher in the high ozone treatment than in the low ozone treatment, and stachyose indicated a similar response in stems. There is a relation between the increase in ABA concentration and cold acclimation in the sugar maple. 29 refs., 7 figs.

  14. A numerical study of summer ozone concentration over the Kanto area of Japan using the MM5/CMAQ model

    Institute of Scientific and Technical Information of China (English)

    Mai Khiem; Ryozo Ooka; Hong Huang; Hiroshi Hayami

    2011-01-01

    We assessed the ability of the MM5/CMAQ model to predict ozone (O3) air quality over the Kanto area and to investigate the factors that affect simulation of O3. We find that the coupled MM5/CMAQ model is a useful tool for the analysis of urban environmental problems. The simulation results were compared with observational data and were found to accurately replicate most of the important observed characteristics. The initial and boundary conditions were found to have a significant effect on simulated O3 concentrations.The results show that on hot and dry days with high O3 concentration, the CMAQ model provides a poor simulation of O3 maxima when using initial and boundary conditions derived from the CMAQ default data. The simulation of peak O3 concentrations is improved with the JCAP initial and boundary conditions. On mild days, the default CMAQ initial and boundary conditions provide a more realistic simulation. Meteorological conditions also have a strong impact on the simulated distribution and accumulation of O3 concentrations in this area. Low O3 concentrations are simulated during mild weather conditions, and high concentrations are predicted during hot and dry weather. By investigating the effects of different meteorological conditions on each model process, we find that advection and diffusion differ the most between the two meteorological regimes. Thus, differences in the winds that govern the transport of O3 and its precursors are likely the most important meteorological drivers of ozone concentration over the central Kanto area.

  15. Disinfection and oxidation of sewage effluent water using ozone and UV technologies.

    Science.gov (United States)

    Oh, B S; Park, S J; Jung, Y J; Park, S Y; Kang, J W

    2007-01-01

    This study was aimed at exploring the reclamation of sewage treatment plant effluent water (SEW) as an alternative water resource. For the oxidation of SEW, an ozone-UV system, based on the results of the combined ozone/UV process performed in our previous study, was set up under practical conditions, including a series type, continuous mode, semi-pilot scale operation (1.5 m3/d). As a result, the serial contact of the ozone and UV reactors showed lower CODCr and TOC removal efficiencies. However, these were greatly enhanced by recycling the water flow of the ozone-UV system at 40Q, as a result of the improvements in the transferred ozone dose in the ozone reactor and the contact efficiency between photons and ozone in the UV reactor, which approached that achieved in the combined ozone/UV process. For the disinfection of SEW, carried out in a syringe-type batch reactor, the increase of instantaneous ozone demand (ozone ID) led to a higher inactivation efficiency, an increased UV transmittance due to ozonation, and an enhanced inactivation rate of E. coli in the UV reactor. Additionally, it was concluded that the ozone/UV process could overcome the limitations of the ozone alone and UV alone processes for the reclamation of sewage effluent water.

  16. Analyzing ground ozone formation regimes using a principal axis factoring method: A case study of Kladno (Czech Republic) industrial area

    Energy Technology Data Exchange (ETDEWEB)

    Malec, L.; Skacel, F. [Department of Gas, Coke and Air Protection, Institute of Chemical Technology in Prague, (Czech Republic)]. E-mail: Lukas.Malec@vscht.cz; Fousek, T. [Institute of Public Health, District of Central Czech Republic, Kladno (Czech Republic); Tekac, V. [Department of Gas, Coke and Air Protection, Institute of Chemical Technology in Prague, (Czech Republic); Kral, P. [Institute of Public Health, District of Central Czech Republic, Kladno (Czech Republic)

    2008-07-15

    Tropospheric ozone is a secondary air pollutant, changes in the ambient content of which are affected by both, the emission rates of primary pollutants and the variability of meteorological conditions. In this paper, we use two multivariate statistical methods to analyze the impact of the meteorological conditions associated with pollutant transformation processes. First, we evaluated the variability of the spatial and temporal distribution of ozone precursor parameters by using discriminant analysis (DA) in locations close to the industrial area of Kladno (a city in the Czech Republic). Second, we interpreted the data set by using factor analysis (FA) to examine the differences between ozone formation processes in summer and in winter. To avoid temperature dependency between the variables, as well as to describe tropospheric washout processes, we used water vapour content rather than the more commonly employed relative humidity parameter. In this way, we were able to successfully determine and subsequently evaluate the various processes of ozone formation, together with the distribution of ozone precursors. High air temperature, radiation and low water content relate to summer pollution episodes, while radiation and wind speed prove to be the most important parameters during winter. [Spanish] El ozono troposferico es un contaminante fotoquimico secundario cuyos contenidos estan influidos tanto por las razones de emision de las sustancias contaminantes primarias como por la variabilidad de las condiciones meteorologicas. En este trabajo utilizamos dos metodos estadisticos multivariados para el analisis de la influencia de las condiciones meteorologicas relacionadas con los procesos de transformacion de las sustancias contaminantes. Primero, estimamos la variabilidad de la descomposicion espacial y temporal de los precursores de ozono mediante el analisis discriminante (DA) en las areas cercanas a la zona industrial de Kladno (una ciudad de la Republica Checa

  17. Effect of gaseous ozone for control of stored product pests at low and high temperature

    DEFF Research Database (Denmark)

    Hansen, Lise Stengård; Hansen, Peer; Vagn Jensen, Karl-Martin

    2013-01-01

    Gaseous ozone (O3) has shown potential for control of insects in stored grain. A previous laboratory study determined doses of ozone necessary to control freely exposed and internal stages of eleven stored product pest species at 20 C. In this study the impact of temperature on the effect of ozon...

  18. Decomposition of 2-mercaptothiazoline in aqueous solution by ozonation.

    Science.gov (United States)

    Chen, Y H; Chang, C Y; Chen, C C; Chiu, C Y; Yu, Y H; Chiang, P C; Ku, Y; Chen, J N; Chang, C F

    2004-07-01

    This study investigates the ozonation of 2-mercaptothiazoline (2-MT). The 2-MT is one of the important organic additives for the electroplating solution of the printed wiring board industry and has been widely used as a corrosion inhibitor in many industrial processes. It is of concern for the aquatic pollution control especially in the wastewaters. Semibatch ozonation experiments in the completely stirred tank reactor are performed under various concentrations of input ozone. The concentrations of 2-MT, sulfate, and ammonium are analyzed at specified time intervals to elucidate the decomposition of 2-MT during the ozonation. In addition, the time variation of the dissolved ozone concentration (C(ALb)) is continuously monitored in the course of experiments. Total organic carbon (TOC) is chosen and measured as a mineralization index of the ozonation of 2-MT. The results indicate that the decomposition of 2-MT is efficient, while the mineralization of TOC is limited via the ozonation only. Simultaneously, the yield of sulfate with the maximum value of about 47% is characterized by the increases of TOC removal and ozone consumption. These results can provide some useful information for assessing the feasibility of the treatment of 2-MT in the aqueous solution by the ozonation.

  19. Vertical ozone characteristics in urban boundary layer in Beijing.

    Science.gov (United States)

    Ma, Zhiqiang; Xu, Honghui; Meng, Wei; Zhang, Xiaoling; Xu, Jing; Liu, Quan; Wang, Yuesi

    2013-07-01

    Vertical ozone and meteorological parameters were measured by tethered balloon in the boundary layer in the summer of 2009 in Beijing, China. A total of 77 tethersonde soundings were taken during the 27-day campaign. The surface ozone concentrations measured by ozonesondes and TEI 49C showed good agreement, albeit with temporal difference between the two instruments. Two case studies of nocturnal secondary ozone maxima are discussed in detail. The development of the low-level jet played a critical role leading to the observed ozone peak concentrations in nocturnal boundary layer (NBL). The maximum of surface ozone was 161.7 ppbv during the campaign, which could be attributed to abundant precursors storage near surface layer at nighttime. Vertical distribution of ozone was also measured utilizing conventional continuous analyzers on 325-m meteorological observation tower. The results showed the NBL height was between 47 and 280 m, which were consistent with the balloon data. Southerly air flow could bring ozone-rich air to Beijing, and the ozone concentrations exceeded the China's hourly ozone standard (approximately 100 ppb) above 600 m for more than 12 h.

  20. Degradation Characteristics of Aniline with Ozonation and Subsequent Treatment Analysis

    Directory of Open Access Journals (Sweden)

    Zhaoqian Jing

    2015-01-01

    Full Text Available Owing to the toxicity and low biodegradability of aniline in water, its removal usually needs high cost processes such as adsorption and advanced oxidation. The degradation characteristics of aniline during ozonation were studied. The influence of operation parameters such as contact time, initial concentration, ozone dosage, temperature, and pH was also investigated. With ozone dosage of 22 mg/L, neutral pH, and room temperature, the ozonation removed aniline efficiently. After two hours’ ozonation, aniline removal reached 93.57%, and the corresponding COD removal was 31.03%, which indicated most of aniline was transformed into intermediates. At alkaline conditions, the aniline was more susceptible to being removed by ozonation owing to more hydroxyl radicals’ production. The results of GC-MS indicated many intermediates appeared during the process of ozonation such as butane diacid, oxalic acid, and formic acid. The intermediates produced during ozonation were more biodegradable than aniline; thus the ozonation of such organic compounds as aniline could be integrated with biological processes for further removal.

  1. On the assimilation of total-ozone satellite data

    Directory of Open Access Journals (Sweden)

    P. F. Levelt

    Full Text Available A two-dimensional model for advection and data assimilation of total-ozone data has been developed. The Assimilation Model KNMI (AMK is a global model describing the transport of the column amounts of ozone, by a wind field at a single pressure level, assuming that total ozone behaves as a passive tracer. In this study, ozone column amounts measured by the TIROS Operational Vertical Sounder (TOVS instrument on the National Oceanic and Atmospheric Administration (NOAA polar satellites and wind fields from the Meteorological Archive and Retrieval System (MARS archives at ECMWF have been used. By means of the AMK, the incomplete space-time distribution of the TOVS measurements is filled in and global total-ozone maps at any given time can be obtained. The choice of wind field to be used for transporting column amounts of ozone is extensively discussed. It is shown that the 200-hPa wind field is the optimal single-pressure-level wind field for advecting total ozone. Assimilated ozone fields are the basic information for research on atmospheric chemistry and dynamics, but are also important for the validation of ozone measurements.

  2. Antarctic ozone loss in 1979–2010: first sign of ozone recovery

    Directory of Open Access Journals (Sweden)

    A. Pazmiño

    2013-02-01

    Full Text Available A long-term ozone loss time series is necessary to understand the evolution of ozone in Antarctica. Therefore, we construct the time series using ground-based, satellite and bias-corrected multi-sensor reanalysis (MSR data sets for the period 1989–2010. The trends in ozone over 1979–2010 are also estimated to further elucidate its evolution in the wake of decreasing halogen levels in the stratosphere. Our analysis with ground-based observations shows that the average ozone loss in the Antarctic is about −33 to −50% (−90 to −155 DU (Dobson Unit in 1989–1992, and then stayed at around −48% (−160 DU. The ozone loss in the warmer winters (e.g. 2002 and 2004 is lower (−37 to −46%, and in the very cold winters (e.g. 2003 and 2006 it is higher (−52 to −55%. These loss estimates are in good agreement with those estimated from satellite observations, where the differences are less than ±3%. The ozone trends based on the equivalent effective Antarctic stratospheric chlorine (EEASC and piecewise linear trend (PWLT functions for the vortex averaged ground-based, Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI, and MSR data averaged over September–November exhibit about −4.6 DU yr−1 over 1979–1999, corroborating the role of halogens in the ozone decrease during the period. The ozone trends computed for the 2000–2010 period are about +1 DU yr−1 for EEASC and +2.6 DU yr−1 for the PWLT functions. The larger positive PWLT trends for the 2000–2010 period indicate the influence of dynamics and other basis functions on the increase of ozone. The trends in both periods are significant at 95% confidence intervals for all analyses. Therefore, our study suggests that Antarctic ozone shows a significant positive trend toward its recovery, and hence, leaves a clear signature of the successful implementation of the Montreal Protocol.

  3. Studies on calibration and validation of data provided by the Global Ozone Monitoring Experiment GOME on ERS-2 (CAVEAT). Final report; Studie zur Kalibrierung und Validation von Daten des Global Ozone Monitoring Experiments GOME auf ERS-2 (CAVEAT). Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, J.P.; Kuenzi, K.; Ladstaetter-Weissenmayer, A.; Langer, J. [Bremen Univ. (Germany). Inst. fuer Umweltphysik; Neuber, R.; Eisinger, M. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Potsdam (Germany)

    2000-04-01

    The Global Ozone Monitoring Experiment (GOME) was launched on 21 April 1995 as one of six scientific instruments on board the second European remote sensing satellite (ERS-2) of the ESA. The investigations presented here aimed at assessing and improving the accuracy of the GOME measurements of sun-standardized and absolute radiation density and the derived data products. For this purpose, the GOME data were compared with measurements pf terrestrial, airborne and satellite-borne systems. For scientific reasons, the measurements will focus on the medium and high latitudes of both hemispheres, although equatorial regions were investigated as well. In the first stage, operational data products of GOME were validated, i.e. radiation measurements (spectra, level1 product) and trace gas column densities (level2 product). [German] Am 21. April 1995 wurde das Global Ozone Monitoring Experiment (GOME) als eines von insgesamt sechs wissenschaftlichen Instrumenten an Bord des zweiten europaeischen Fernerkundungssatelliten (ERS-2) der ESA ins All gebracht. Das Ziel dieses Vorhabens ist es, die Genauigkeit der von GOME durchgefuehrten Messungen von sonnennormierter und absoluter Strahlungsdichte sowie der aus ihnen abgeleiteten Datenprodukte zu bewerten und zu verbessern. Dazu sollten die GOME-Daten mit Messungen von boden-, flugzeug- und satellitengestuetzten Systemen verglichen werden. Aus wissenschaftlichen Gruenden wird der Schwerpunkt auf Messungen bei mittleren und hohen Breitengraden in beiden Hemisphaeren liegen. Jedoch wurden im Laufe des Projektzeitraumes auch Regionen in Aequatornaehe untersucht. Im ersten Schritt sollen operationelle Datenprodukte von GOME validiert werden. Dieses sind Strahlungsmessungen (Spektren, Level1-Produkt) und Spurengas-Saeulendichten (Level2-Produkt). (orig.)

  4. Ozone toxicity and walking response of populations of Sitophilus zeamais (Coleoptera: Curculionidae).

    Science.gov (United States)

    Sousa, A H; Faroni, L R A; Silva, G N; Guedes, R N C

    2012-12-01

    Ozone is a recognized alternative to the fumigants methyl bromide and phosphine for the control of stored product insects. However, as with fumigants in general, the potential sublethal effects of ozone on targeted insect species may compromise its efficacy and has yet to be investigated. Here, we determined ozone toxicity of 30 field-collected populations of the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae), and assessed the walking response of adult insects from these populations to sublethal ozone exposure. Time-mortality toxicity to ozone at 50 ppm concentration in a continuous 2 liter/min flow indicated uniform susceptibility among the populations studied without any indication of ozone resistance (toxicity ratios [at LT50] > two-fold). In contrast, there was significant variation in walking activity among the maize weevil populations, which was not correlated with ozone susceptibility. This was not surprising because of the relatively uniform susceptibility to ozone among the maize weevil populations. Respiration rate affected ozone toxicity but not walking activity, whereas body mass was negatively correlated with walking activity but was not correlated with ozone toxicity. Based on our data, lower respiration rates may potentially lead to reduced ozone uptake whereas larger body mass limits walking activity. Ozone seems a promising alternative fumigant with low short-term risk of resistance development because of the high susceptibility and low variability of response to this compound. Furthermore, ozone reduces walking activity of S. zeamais that implies it likely reduces the chances of insects escaping exposure at the early stages of fumigation.

  5. Removal of a type of endocrine disruptors-di-n-butyl phthalate from water by ozonation

    Institute of Scientific and Technical Information of China (English)

    LI Hai-yan; QU Jiu-hui; LIU Hui-juan

    2006-01-01

    Ozonation of synthetic water containing a type of endocrine disruptor-di-n-butyl phthalate (DBP) was examined. Key impact factors such as pH, temperature, ionic strength, ozone dosage and initial DBP concentration were investigated. In addition, the activities of radicals on uncatalysed and catalysed ozonation were studied. The degradation intermediate products were followed and the kinetic of the ozonation were assessed as well. Results revealed that ozonation of DBP followed two mechanisms. Firstly, the reaction rate of direct ozonation was slower at lower pH, temperature, and ionic strength. Secondly, when these factors were increased for indirect radical reaction, higher percentage of DBP was removed with the increase of the initial ozone dosage and the decrease of the initial DBP concentration. In addition, tert-butanol, humic substances and Fe(Ⅱ) affected DBP ozonation through the radical pathway. It was determined that ozonation was restrained by adding tert-butanol for its radical inhibition effect. Furthermore, humic substances enhanced the reaction to some extent, but a slight negative effect would be encountered if the optimum dosage was exceeded. As a matter of fact, Mn(Ⅱ) affected the ozonation by "active sites" mechanism. In the experiment, three different kinds of intermediate products were produced during ozonation, but the amount of products for each one of them decreased as pH, temperature,ionic strength and initial ozone dosage increased. A kinetic equation of the reaction between ozone and DBP was obtained.

  6. Ozone modeling within plasmas for ozone sensor applications

    OpenAIRE

    Arshak, Khalil; Forde, Edward; Guiney, Ivor

    2007-01-01

    peer-reviewed Ozone (03) is potentially hazardous to human health and accurate prediction and measurement of this gas is essential in addressing its associated health risks. This paper presents theory to predict the levels of ozone concentration emittedfrom a dielectric barrier discharge (DBD) plasma for ozone sensing applications. This is done by postulating the kinetic model for ozone generation, with a DBD plasma at atmospheric pressure in air, in the form of a set of rate equations....

  7. Ozone modeling within plasmas for ozone sensor applications

    OpenAIRE

    Arshak, Khalil; Forde, Edward; Guiney, Ivor

    2007-01-01

    peer-reviewed Ozone (03) is potentially hazardous to human health and accurate prediction and measurement of this gas is essential in addressing its associated health risks. This paper presents theory to predict the levels of ozone concentration emittedfrom a dielectric barrier discharge (DBD) plasma for ozone sensing applications. This is done by postulating the kinetic model for ozone generation, with a DBD plasma at atmospheric pressure in air, in the form of a set of rate equations....

  8. El poblamiento temprano de la costa norte de Chile

    Directory of Open Access Journals (Sweden)

    Varela, Héctor Hugo

    2005-01-01

    Full Text Available La costa Norte de Chile estuvo habitada por lo menos desde 10000 AP por pequeños grupos humanos que subsistían de los recursos del mar y la costa. Ellos estaban asociados con la cultura Chinchorro, caracterizada por el tratamiento artificial que le daban a sus muertos. El sitio Caleta Huelén 42 se encuentra ubicado en la desembocadura del río Loa en el Norte de Chile. Constituye una importante conexión hacia el sur, vinculada con la expansión de los grupos de pescadores arcaicos semejantes a Morro 1 y Morro 1-6 y que continúa hacia Punta de Teatinos y El Cerrito. La presente experiencia tiene como objetivo establecer las relaciones biológicas de Caleta Huelén 42 con otros grupos arcaicos costeros. La colección está constituida por 33 individuos y los fechados conocidos la ubican entre el 4780 y el 3780 AP. Las afinidades biológicas con grupos semejantes (Morro 1, Morro 1/6, Morro Uhle, El Cerrito y Punta de Teatinos se analizan mediante el empleo de 29 caracteres métricos del cráneo y la aplicación de diferentes técnicas de análisis multivariado. Se demostró la existencia de dos conglomerados biológicos uno constituido por las muestras del Norte Árido (Morro Uhle, Morro 1, Morro1/6 y Caleta Huelén 42 y el otro por las series del Norte Semiárido (El Cerrito y Punta de Teatinos. Los fundadores de Caleta Huelén 42 son el resultado de la migración hacia el sur de una pequeña banda de cazadores recolectores arcaicos, que conservaron parte de genoma original y características culturales que los conecta con la tradición Chinchorro. Además, es posible que hayan recibido el aporte genético de grupos arcaicos proveniente del interior del continente a través del río Loa.

  9. Frontera Norte: estructura de poder y medios de comunicacion

    Directory of Open Access Journals (Sweden)

    Florence Toussaint

    1991-01-01

    Full Text Available This article makes known some cultural features belonging to the Northern border, in particular communication media, above all radio and television broadcasting in the cities bordering with the US: Baja California Norte, Tijuana, Mexicali, Sonora, Ciudad Obregon, Hermosillo, Nogales, Chihuahua, Coahuila, Piedras Negras, Ciudad Acuiia, Nuevo Le6n, Montertrey, Tamaulipas, Nuevo Laredo,Reynosa, and Matamoros. The article makes known as well the groups of economic power who control the functioning of the TV stations -both producing and broadcasting in each city.

  10. Ozone Depletion by Hydrofluorocarbons

    Science.gov (United States)

    Hurwitz, M.; Fleming, E. L.; Newman, P. A.; Li, F.; Mlawer, E. J.; Cady-Pereira, K. E.; Bailey, R.

    2015-12-01

    Hydrofluorocarbons (HFCs) are second-generation replacements for the chlorofluorocarbons (CFCs), halons and other substances that caused the 'ozone hole'. Atmospheric concentrations of HFCs are projected to increase dramatically in the coming decades. Coupled chemistry-climate simulations forced by these projections show that HFCs will impact the global atmosphere in 2050. As strong radiative forcers, HFCs modulate atmospheric temperature, thereby changing ozone-destroying catalytic cycles and enhancing the stratospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Sensitivity simulations with the NASA Goddard Space Flight Center (GSFC) 2D model show that HFC-125 is the most important contributor to atmospheric change in 2050, as compared with HFC-23, HFC-32, HFC-134a and HFC-143a. Incorporating the interactions between chemistry, radiation and dynamics, for a likely 2050 climate, ozone depletion potentials (ODPs) for HFCs range from 4.3x10-4 to 3.5x10-2; previously HFCs were assumed to have negligible ODPs since these species lack chlorine or bromine atoms. The ozone impacts of HFCs are further investigated with the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). The GEOSCCM is a three-dimensional, fully coupled ocean-atmosphere model with interactive stratospheric chemistry. Sensitivity simulations in which CO2, CFC-11 and HCFC-22 are enhanced individually are used as proxies for the atmospheric response to the HFC concentrations expected by the mid-21st century. Sensitivity simulations provide quantitative estimates of the impacts of these greenhouse gases on global total ozone, and can be used to assess their effects on the recovery of Antarctic ozone.

  11. Monica del Norte - Eesti maalikunstnik päikeselises Hispaanias / Anne-Mari Alver

    Index Scriptorium Estoniae

    Alver, Anne-Mari

    2006-01-01

    Deivi Oru alias Monica del Norte eneseleidmisest maalikunstniku, sisekujundaja ja kunstiõpetajana Hispaanias. Kunstnik teeb oma maalidele ise raamid. Koos abikaasa Alaniga on ta soetanud Räpina lähistele talukoha, millest tulevikus peaks saama näituste ja kunstilaagrite paik. 26. augustini on Monica del Norte maalid väljas Artdepoo galeriis

  12. Monica del Norte - Eesti maalikunstnik päikeselises Hispaanias / Anne-Mari Alver

    Index Scriptorium Estoniae

    Alver, Anne-Mari

    2006-01-01

    Deivi Oru alias Monica del Norte eneseleidmisest maalikunstniku, sisekujundaja ja kunstiõpetajana Hispaanias. Kunstnik teeb oma maalidele ise raamid. Koos abikaasa Alaniga on ta soetanud Räpina lähistele talukoha, millest tulevikus peaks saama näituste ja kunstilaagrite paik. 26. augustini on Monica del Norte maalid väljas Artdepoo galeriis

  13. Flora útil de los cafetales en la Sierra Norte de Puebla, México Useful plants of the Sierra Norte de Puebla, Mexico

    National Research Council Canada - National Science Library

    Miguel Ángel Martínez; Virginia Evangelista; Francisco Basurto; Myrna Mendoza; Antonio Cruz-Rivas

    2007-01-01

    Los cafetales de la Sierra Norte de Puebla son agroecosistemas variados en composición y estructura, donde se pueden encontrar especies vegetales cultivadas y silvestres, nativas e introducidas, y cuya diversidad florística está...

  14. Children's Models of the Ozone Layer and Ozone Depletion.

    Science.gov (United States)

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  15. Children's Models of the Ozone Layer and Ozone Depletion.

    Science.gov (United States)

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  16. Recovery of the Ozone Layer: The Ozone Depleting Gas Index

    Science.gov (United States)

    Hofmann, David J.; Montzka, Stephen A.

    2009-01-01

    The stratospheric ozone layer, through absorption of solar ultraviolet radiation, protects all biological systems on Earth. In response to concerns over the depletion of the global ozone layer, the U.S. Clean Air Act as amended in 1990 mandates that NASA and NOAA monitor stratospheric ozone and ozone-depleting substances. This information is critical for assessing whether the Montreal Protocol on Substances That Deplete the Ozone Layer, an international treaty that entered into force in 1989 to protect the ozone layer, is having its intended effect of mitigating increases in harmful ultraviolet radiation. To provide the information necessary to satisfy this congressional mandate, both NASA and NOAA have instituted and maintained global monitoring programs to keep track of ozone-depleting gases as well as ozone itself. While data collected for the past 30 years have been used extensively in international assessments of ozone layer depletion science, the language of scientists often eludes the average citizen who has a considerable interest in the health of Earth's protective ultraviolet radiation shield. Are the ozone-destroying chemicals declining in the atmosphere? When will these chemicals decline to pre-ozone hole levels so that the Antarctic ozone hole might disappear? Will this timing be different in the stratosphere above midlatitudes?

  17. Empregabilidade do profissional formado nos cursos superiores de tecnologia do CEFET-PR: estudo de caso em médias e grandes empresas da região norte do Paraná Empregabilidad del profesional graduado en los cursos superiores de tecnología: estudio de caso en las medias y grandes empresas de la región norte del Paraná Empregability of the graduates in the undergraduate courses of technology: study of case in medium-sized and large companies in the northern region of the state Paraná

    Directory of Open Access Journals (Sweden)

    Eurico Pedroso de Almeida Junior

    2007-09-01

    Full Text Available O presente trabalho discute a necessidade das empresas da região Norte do Paraná, por profissionais formados nos Cursos Superiores de Tecnologia. Trata-se de uma pesquisa exploratória que, em função dos procedimentos técnicos adotados, pode ser caracterizada como um estudo de caso. O método de pesquisa empregado foi o indutivo. Os resultados mostram que há por parte das empresas a necessidade por profissionais formados nos Cursos Superiores de Tecnologia, na maioria dos casos, ele atua dentro de sua área de formação, e sua convivência com outros profissionais formados nas áreas tecnológicas ocorre normalmente. Concluiu-se que o tecnólogo no ambiente produtivo é um profissional necessário e que colabora em várias frentes, principalmente em face às novas tendências tecnológicas, uma vez que o mesmo recebe conhecimento teórico e prático e pode contribuir eficazmente tanto com as empresas quanto com a sociedade.Esa investigación discute la necesidad de las compañías del área Norte de Paraná por profesionales formados en las Universidades de Tecnología. Es una investigación exploratoria que, por los procedimientos técnicos adoptados, puede caracterizarse como un estudio de caso. El método de la investigación usado fue el inductivo. Los resultados confirman que hay por parte de las compañías la necesidad de profesionales formados en las Universidades de Tecnología; en la mayor parte de los casos ellos actúan dentro de su área de formación específica, y su convivencia con otros profesionales formados en las áreas tecnológicas ocurre normalmente. La conclusión de la investigación presenta el tecnólogo en el ambiente productivo como un profesional necesario a colaborar en varios frentes, principalmente si pensamos en las nuevas tendencias tecnológicas, una vez que él recibe el conocimiento teórico y práctico y puede contribuir eficazmente tanto con las compañías en cuanto a la sociedad.The present paper

  18. Ozone-depleting Substances (ODS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

  19. Molecular storage of ozone in a clathrate hydrate: an attempt at preserving ozone at high concentrations.

    Directory of Open Access Journals (Sweden)

    Takahiro Nakajima

    Full Text Available This paper reports an experimental study of the formation of a mixed O(3+ O(2+ CO(2 hydrate and its frozen storage under atmospheric pressure, which aimed to establish a hydrate-based technology for preserving ozone (O(3, a chemically unstable substance, for various industrial, medical and consumer uses. By improving the experimental technique that we recently devised for forming an O(3+ O(2+ CO(2 hydrate, we succeeded in significantly increasing the fraction of ozone contained in the hydrate. For a hydrate formed at a system pressure of 3.0 MPa, the mass fraction of ozone was initially about 0.9%; and even after a 20-day storage at -25°C and atmospheric pressure, it was still about 0.6%. These results support the prospect of establishing an economical, safe, and easy-to-handle ozone-preservation technology of practical use.

  20. Investigating the long-term evolution of subtropical ozone profiles applying ground-based FTIR spectrometry

    OpenAIRE

    García, O.E.; Schneider, M; A. Redondas; Y. González; Hase, F.; Blumenstock, T.; Sepúlveda, E.

    2012-01-01

    This study investigates the long-term evolution of subtropical ozone profile time series (1999–2010) obtained from ground-based FTIR (Fourier Transform InfraRed) spectrometry at the Izaña Observatory ozone super-site. Different ozone retrieval strategies are examined, analysing the influence of an additional temperature retrieval and different constraints. The theoretical assessment reveals that the FTIR system is able to resolve four independent ozone layers with a precision of better than 6...

  1. Ozone-induced changes in carotenoids and chlorophylls in three Populus clones

    OpenAIRE

    Keski-Saari, Sarita; Dumont, Jennifer; Keinänen, Markku; Kontunen-Soppela, Sari; Oksanen, Elina; Le Thiec, Didier

    2011-01-01

    Ozone is a phytotoxic air pollutant causing oxidative stress. We studied the effect of ozone on carotenoids, chlorophylls and polyisoprenoid alcohols in three euramerican poplar clones (Populus deltoides x Populus nigra: 'Carpaccio', 'Cima' and 'Robusta'). Poplars originating from cuttings were grown for 6 weeks and exposed to ozone in fumigation chambers (120 ppb each day for 13h). Leaf samples were collected 2, 4, 11, 15 and 17 days after the start of ozone treatment. Chemical analyses were...

  2. Ozone photolysis of paracetamol in aqueous solution.

    Science.gov (United States)

    Neamţu, Mariana; Bobu, Maria; Kettrup, Antonius; Siminiceanu, Ilie

    2013-01-01

    The degradation of a paracetamol (N-acetil-para-aminofenol) aqueous solution (C (0) P = 5 mmol L(-1)) is studied in a bench-scale setup by means of simple ozonation (O3) and ozonation catalyzed with UV light (O3/UV) in order to quantify the influence of UV light on the degradation process. The results have shown that under the adopted experimental conditions (25°C, applied ozone dose = 9.8 mg L(-1) and gas flow rate of 20 L h(-1)) both oxidative systems are capable of removing the substrate with mineralization degrees up to 51% for ozonation and 53% for O3/UV. HPICE chromatography allowed the detection of nitrate ions and maleic and oxalic acids as ultimate carboxylic acids. The experimental data have been interpreted through 5 indicators: the conversion of paracetamol (XP ), the conversion degree of TOC (XTOC ), the apparent rate constant (kap ), the Hatta number (Ha) and the enhancement factor (E). The main advantage of photo-ozonation compared to simple ozonation was a more advanced conversion (79% vs. 92% after 90 min). The paracetamol decay follows a pseudo-first-order reaction with a superior rate constant (higher by 54%) for the UV catalyzed system in comparison with direct ozonation. Mineralization is slightly accelerated (+4%) in the O3/UV system, due to the additional production of hydroxyl radicals induced by the UV light and a higher Hatta number (+24%). Nevertheless, the process was still in the slow reaction kinetic regime (Ha < 0.3), and the enhancement factor was not significantly increased. The results are useful for the design and scale-up of the gas-liquid processes.

  3. Theoretical study on the reaction mechanism of ozone addition to the double bonds of keto-limonene

    Institute of Scientific and Technical Information of China (English)

    Lei Jiang; Yisheng Xu; Baohui Yin; Zhipeng Bai

    2012-01-01

    The reaction mechanism of ozone (O3) addition to the double bonds of gas phase keto-limonene was investigated using ab initio methods.Two different possibilities for O3 addition to the double bond were considered and two corresponding van der Waais complexes (Complex 1 and Complex 2) were found for 1-endo and 2-endo.The rate constants were calculated using the transition state theory at the CCSD(T)/6-31G(d) + CF//B3LYP/6-31G(d,p) level.The high-pressure limit of the total rate constant at 298 K was 3.51 × 10-16cm3/(molecule.sec),which was in a good agreement with the experimental data.

  4. Ozone Diurnal Variation in the PBL at the Boulder Atmospheric Observatory During Summer 2014

    Science.gov (United States)

    Newchurch, M.; Alvarez, R. J. _II, II; Brewer, A.; Brown, S. S.; Carrion, W.; Delgado, R.; De Young, R.; Huang, G.; Johnson, B.; Kuang, S.; Langford, A. O.; Lundquist, J. K.; McGee, T. J.; Pliutau, D.; Senff, C. J.; Sullivan, J. T.; Sumnicht, G. K.; Twigg, L.; Wang, L.

    2014-12-01

    We investigate the diurnal variation of PBL ozone at the Boulder Atmospheric Observatory (BAO) in July 2014 using multiple observations, including three ozone DIALs, several wind Doppler lidars, free-launched and tethered ozonesondes, and in-situ measurements on the BAO tower. Three mobile lidars from the Tropospheric Ozone Lidar NETwork (TOLNET) provide high spatial and temporal ozone profiles from near surface to the top of the troposphere. The combination of multiple observations will provide detailed structure of the diurnal variation of ozone. This ozone information will help the satellite and modeling communities to study the character of lower tropospheric ozone for the improvements of satellite retrieval and air-quality models. In addition, a Large-Eddy Simulation model will calculate ozone in the mixed layer to explain the processes responsible for the observations.

  5. The Ideas of Greek High School Students about the "Ozone Layer."

    Science.gov (United States)

    Boyes, Edward; Stanisstreet, Martin; Papantoniou, Vasso Spiliotopoulou

    1999-01-01

    Describes a study of Greek high school students' (n=116) perceptions of the ozone layer. Finds that students have a good understanding of the position and purpose of the ozone layer in terms of protection from ultraviolet rays, but students also hold misconceptions linking the ozone layer to the greenhouse effect and other forms of local…

  6. Sensitivity analysis of ground level ozone in India using WRF-CMAQ models

    NARCIS (Netherlands)

    Sharma, Sumit; Chatani, Satoru; Mahtta, Richa; Goel, Anju; Kumar, Atul

    2016-01-01

    Ground level ozone is emerging as a pollutant of concern in India. Limited surface monitoring data reveals that ozone concentrations are well above the prescribed national standards. This study aims to simulate the regional and urban scale ozone concentrations in India using WRF-CMAQ models. Sector-

  7. Interaction between ozone and airborne particulate matter in office air

    DEFF Research Database (Denmark)

    Mølhave, Lars; Kjærgaard, Søren K.; Sigsgaard, Torben

    2005-01-01

    This study investigated the hypotheses that humans are affected by air pollution caused by ozone and house dust, that the effect of simultaneous exposure to ozone and dust in the air is larger than the effect of these two pollutants individually, and that the effects can be measured as release...

  8. An analysis of regional differences in tropospheric ozone over Europe

    NARCIS (Netherlands)

    Builtjes, P.J.H.; Esser, P.J.; Roemer, M.G.M.

    1998-01-01

    It is a well known fact, based on observations and modelling studies, that there are large spatial gradients over Europe in ozone characteristics. These differences are caused by the differences in strength of the phenomena which determine the ozone concentration at a specific location: the precurso

  9. Kinetics of ozone-phenol reaction in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, M.G.; Shambaugh, R.L.

    1982-01-01

    The kinetics of the reaction of ozone and phenol in aqueous medium was studied. The reaction was first order with respect to both ozone and phenol. The rate constant was found to increase with increase in the pH of the reaction mixture. Four different catalysts were examined for their effect on the rate of reaction. 30 refs.

  10. 村镇供水中臭氧消毒副产物溴酸盐生成规律研究%Study on formation law of byproduct——bromate during ozone disinfection for rural drinking water supply

    Institute of Scientific and Technical Information of China (English)

    贾燕南; 宋卫坤; 李晓琴; 胡孟; 刘文朝

    2013-01-01

    结合村镇供水特点,本文采取三种投加方式对9省63份作为饮用水水源的地下水水样进行臭氧投加试验,考察了不同地区的水样消毒后生成溴酸盐浓度水平的差异,研究了臭氧投加量、投加方式对溴酸盐生成浓度的影响.结果表明:原水溴离子浓度越低,pH值越低,投加臭氧后生成的溴酸盐量也较小;溴酸盐生成量与臭氧投加量在一定范围内呈线性正相关关系.同一投加量下,三种臭氧投加方式对应的溴酸盐生成量由小到大依次为:投加高浓度臭氧水、水射器投加、直接通入臭氧气体.%In accordance with the characteristics of rural drinking water supply, the ozone adding experiment on the groundwater samples from 63 water sources for the rural drinking water in 9 provinces is made with three ozone dosing methods, and then the difference among the levels of bromate concentrations formed after the disinfections of the water samples from various areas is investigated and the impacts from both the ozone dosing and the dosing method on the bromate forming concentration are studied.The result shows that the less the bromonium ion concentration of the raw water is, the lower the pH value is to be, and then the less content of the bromate formed after ozone adding is to be as well, while the bromate formation shows linear positive correlation with the ozone dosage with a certain range.Under an identical dosing, the bromate formations corresponded to the three o-zone dosing methods, i.e.adding high concentration ozone water, adding by water-jet, direct adding of ozone gas, vary in an order from less to large.

  11. Inactivation of enteroviruses in sewage with ozone

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, O.E.; Bogdanov, M.V.; Kazantseva, V.A.; Gabrilevskaia, L.N.; Kodkind, G.K.H.

    The study of ozone inactivation of enteroviruses in sewage showed the presence in sewage of suspensions of organic origin and bacterial flora to influence the rate of inactivation. The inactivation rate of poliomyelitis virus in sewage free from organic suspension and bacterial flora was significantly higher than that in sewage containing such suspension and bacterial flora. The inactivation rate of enteroviruses was found not to depend upon the protein and salt composition and pH of sewage or strain appurtenance of viruses. The inactivation rate of enteroviruses directly depended upon the dose of ozone and time of contact with it. Differences in the resistance of different types of poliomyelitis virus, ECHO and Coxsackie viruses to the effect of ozone are likely exist. These differences are manifested within the range of relatively small doses of ozone. E. coli is more resistant to ozone than entero-viruses. The results of laboratory studies were used to choose the regimen of sanitation of urban sewage to be used in technological cycles of industrial enterprises.

  12. Cumulative ozone effect on canopy stomatal resistance and the impact on boundary layer dynamics and CO2 assimilation at the diurnal scale: A case study for grassland in the Netherlands

    NARCIS (Netherlands)

    Super, I.; Vilà-Guerau De Arellano, J.; Krol, M.C.

    2015-01-01

    Biological, chemical, and dynamical processes occurring at the surface strongly interact at diurnal scales. Therefore, this study examines the seasonal ozone impact on stomatal resistance, surface energy balance, boundary layer dynamics, and CO2 assimilation at this (sub)diurnal scale under changing

  13. Cumulative ozone effect on canopy stomatal resistance and the impact on boundary layer dynamics and CO2 assimilation at the diurnal scale: A case study for grassland in the Netherlands

    NARCIS (Netherlands)

    Super, I.; Vilà-Guerau De Arellano, J.; Krol, M.C.

    2015-01-01

    Biological, chemical, and dynamical processes occurring at the surface strongly interact at diurnal scales. Therefore, this study examines the seasonal ozone impact on stomatal resistance, surface energy balance, boundary layer dynamics, and CO2 assimilation at this (sub)diurnal scale under changing

  14. Total ozone columns and vertical ozone profiles above Kiev in 2005-2008

    CERN Document Server

    Shavrina, A V; Sheminova, V A; Pavlenko, Ya V; Veles, A A; Synyavski, I I; Romanyuk, Ya O

    2010-01-01

    The study of total ozone columns above Kiev and variations of ozone concentrations in the troposphere at different altitudes above Kiev was carried out using ground-based Fourier Transform InfraRed (FTIR) spectrometric observations that are taken on a routine basis at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (MAO NASU). This study was performed within the framework of the international ESA-NIVR-KNMI OMI-AO project no.2907 entitled OMI validation by ground-based remote sensing: ozone columns and atmospheric profiles during the time frame 2005-2008. The infrared FTIR spectral observations of direct solar radiation in the wavelength range of 2-12 micron as transmitted through the Earth's atmosphere were performed during the months of April-October of each year. The aim of the project was the validation of total ozone columns and vertical ozone profiles as obtained by the Ozone Monitoring Instrument (OMI)) onboard of the NASA EOS-Aura scientific satellite platform. The mode...

  15. A relação dos técnicos de educação de adultos com o discurso pedagógico oficial: um caso a norte de Portugal The relation between adult education agents and the official pedagogical discourse: a case study in northern Portugal

    Directory of Open Access Journals (Sweden)

    Armando Paulo Ferreira Loureiro

    2008-12-01

    Full Text Available O presente artigo pretende questionar, com base num estudo etnográfico realizado junto de uma equipa técnica de educação de adultos de uma associação de desenvolvimento local do norte de Portugal, a relação que este tipo de técnicos estabelece com o discurso pedagógico oficial proveniente de estruturas de informação que estão na dependência do Estado. Para realizar tal análise recorreu-se, do ponto de vista teórico, ao modelo da estrutura do discurso pedagógico de Basil Bernstein. Os resultados dizem-nos que, neste caso concreto, os técnicos, apesar de terem a sua acção fortemente normativizada, são capazes de estabelecer com o discurso oficial uma relação activa, pois no desenrolar da sua actividade fazem, muitas vezes, usos recontextualizados desse discurso.Based on an ethnographic study of a team of adult education agents in an association of local development in the North of Portugal, this paper is aimed at studying the relation that these agents establish with the official pedagogical discourse emerging from State-dependent information structures. In order to develop this analysis, Basil Bernstein's model of pedagogical discourse structure was used for a theoretical basis. The results have showed that, in this particular case, the agents, in spite of having a strongly normative action, are able to establish an active relation with the official discourse. It can be observed that they often readapt this official discourse in their daily activity.

  16. LA COMUNICACIÓN NO VERBAL-EXPRESIVO CORPORAL EN UN CONTEXTO ESCOLAR INTERCULTURAL EN EL NORTE DE ÁFRICA: ESTUDIO COMPARATIVO ENTRE NIÑOS EUROPEOS VS AMAZIGH NONVERBAL -CORPORAL EXPRESSIVE (COMMUNICATION IN AN INTERCULTURAL SCHOOL CONTEXT IN NORTH AFRICA: COMPARATIVE STUDY BETWEEN EUROPEAN VS AMAZIGH CHILDREN

    Directory of Open Access Journals (Sweden)

    Cremades Roberto

    2010-04-01

    Full Text Available Resumen:En este artículo se ha llevado a cabo un estudio comparativo acerca de los diferentes tipos de comportamiento relacionados con la comunicación no verbal y la expresión corporal que se dan entre niños de edad escolar con pertenencia a dos grupos étnicos diferentes (europeo y amazigh. El estudio se ha desarrollado en la ciudad de Melilla (España, población situada en el norte occidental de África y caracterizada por una gran diversidad social y cultural de sus habitantes (europeos, imazighen5, judíos sefardíes e hindúes. Para ello, han participado 100 alumnos (57 niños y 43 niñas, siendo el 50% de origen cultural europeo y el 50% de origen cultural amazigh, a los que se evaluó a través de diferentes pruebas de carácter observacional. Los resultados obtenidos revelan que los niños europeos usan más la comunicación no verbal que los de la cultura amazigh.Abstract:This article has conducted a comparative study about different kinds of behaviour related to non verbal communication and the corporal expression that happen among school-age children who belong to two different ethnic groups (European and Amazigh. The study has been developed in the city of Melilla (Spain, located in western North Africa. This city is characterized by social and cultural diversity of its citizens (Europeans, Berbers, Sephardic Jews and Indians. Some 100 students participated (57 boys and 43 gilrs, of which 50% were of European cultural origin and 50% of Amazigh cultural origin, which was evaluated through different observational tests. Results show that European children use nonverbal communication more than those of the Amazigh culture.

  17. Quantifying Ozone Production throughout the Boundary Layer from High Frequency Tethered Profile Measurements during a High Ozone Episode in the Uinta Basin, Utah

    Science.gov (United States)

    Sterling, C. W.; Johnson, B.; Schnell, R. C.; Oltmans, S. J.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Windell, J.; McClure-Begley, A.; Helmig, D.; Petron, G.

    2015-12-01

    During the Uinta Basin Winter Ozone Study (UBWOS) in Jan - Feb 2013, 735 tethered ozonesonde profiles were obtained at 3 sites including during high wintertime photochemical ozone production events that regularly exceeded 125 ppb. High resolution profiles of ozone and temperature with altitude, measured during daylight hours, showed the development of approximately week long high ozone episodes building from background levels of ~40 ppb to >150 ppb. The topography of the basin combined with a strong temperature inversion trapped oil and gas production effluents in the basin and the snow covered surface amplified the sun's radiation driving the photochemical ozone production at rates up to 13 ppb/hour in a cold layer capped at 1600-1700 meters above sea level. Beginning in mid-morning, ozone mixing ratios throughout the cold layer increased until late afternoon. Ozone mixing ratios were generally constant with height indicating that ozone production was nearly uniform throughout the depth of the cold pool. Although there was strong diurnal variation, ozone mixing ratios increased during the day more than decreased during the night, resulting in elevated levels the next morning; an indication that nighttime loss processes did not compensate for daytime production. Even though the 3 tethersonde sites were at elevations differing by as much as 140 m, the top of the high ozone layer was nearly uniform in altitude at the 3 locations. Mobile van surface ozone measurements across the basin confirmed this capped structure of the ozone layer; the vehicle drove out of high ozone mixing ratios at an elevation of ~1900 meters above sea level, above which free tropospheric ozone mixing ratios of ~50 ppb were measured. Exhaust plumes from a coal-fired power plant in the eastern portion of the basin were intercepted by the tethersondes. The structure of the profiles clearly showed that effluents in the plumes were not mixed downward and thus did not contribute precursor nitrogen

  18. La "gente del desierto" en el norte de Sonora

    Directory of Open Access Journals (Sweden)

    Hernán Javier Salas Quintanal

    2006-01-01

    Full Text Available La construcción de la frontera política administrativa, a mediados del siglo diecinueve, entre Arizona (Estados Unidos y Sonora (México provocó una dispersión entre los pápagos que quedaron al lado mexicano y los que se ubicaron al norte de la línea fronteriza. Durante años esta división generó un alejamiento en los estilos de vida y en la forma de habitar un ambiente desértico; en la actualidad, la frontera política se expresa en las esferas de la vida social, económica y cultural. En este artículo se hace referencia a la situación de los pápagos, la "gente del desierto" que habita el desierto de Altar, al norte de Sonora, quienes actualizan sus referentes comunes para identificarse como etnia y como grupo.

  19. Investigations of the mycorrhiza reactions to ozone and acid mist. Untersuchungen zur Reaktion von Mykorrhizen auf Ozon und sauren Nebel

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, M. (Muenchen Univ. (Germany, F.R.). Inst. fuer Systematische Botanik)

    1989-07-01

    In several experiments the root system and the mycorrhizae of Picea abies were studied in their reaction to different soils and to application of ozon and acid mist. While significant responses to substrat could be found, the tested parameters in most cases did not show significant reactions to the applicated ozon and acid mist. (orig.).

  20. RESEARCH OF QUALITY CONTROL OF OZONE CONCENTRATIONS IN A BEEHIVE USING A STABILIZING SYSTEM OF OZONIZATION O