WorldWideScience

Sample records for blue haze enhanced

  1. Enhanced haze pollution by black carbon in megacities in China

    Science.gov (United States)

    Ding, A. J.; Huang, X.; Nie, W.; Sun, J. N.; Kerminen, V.-M.; Petäjä, T.; Su, H.; Cheng, Y. F.; Yang, X.-Q.; Wang, M. H.; Chi, X. G.; Wang, J. P.; Virkkula, A.; Guo, W. D.; Yuan, J.; Wang, S. Y.; Zhang, R. J.; Wu, Y. F.; Song, Y.; Zhu, T.; Zilitinkevich, S.; Kulmala, M.; Fu, C. B.

    2016-03-01

    Aerosol-planetary boundary layer (PBL) interactions have been found to enhance air pollution in megacities in China. We show that black carbon (BC) aerosols play the key role in modifying the PBL meteorology and hence enhancing the haze pollution. With model simulations and data analysis from various field observations in December 2013, we demonstrate that BC induces heating in the PBL, particularly in the upper PBL, and the resulting decreased surface heat flux substantially depresses the development of PBL and consequently enhances the occurrences of extreme haze pollution episodes. We define this process as the "dome effect" of BC and suggest an urgent need for reducing BC emissions as an efficient way to mitigate the extreme haze pollution in megacities of China.

  2. Enhanced Haze Ratio on Glass by Novel Vapor Texturing Method.

    Science.gov (United States)

    Lee, Seunghwan; Balaji, Nagarajan; Ju, Minkyu; Park, Cheolmin; Kim, Jungmo; Chung, Sungyoun; Lee, Youn-Jung

    2016-05-01

    State-of-the-art optical trapping designs are required to enhance the light trapping capabilities of tandem thin film silicon solar cells. The wet etch process is used to texture the glass surface by dipping in diluted acidic solutions such as HNO3 (nitric acid) and HF (hydrofluoric acid). For vapor texturing, the vapor was generated by adding silicon to HF:HNO3 acidic solution. The anisotropic etching of vapor textured wafers resulted in an etching depth of about 2.78 μm with reduced reflectance of 5%. We achieved a high haze value of 74.6% at a 540 nm wavelength by increasing the etching time and HF concentration. PMID:27483862

  3. Urban heat islands in China enhanced by haze pollution.

    Science.gov (United States)

    Cao, Chang; Lee, Xuhui; Liu, Shoudong; Schultz, Natalie; Xiao, Wei; Zhang, Mi; Zhao, Lei

    2016-01-01

    The urban heat island (UHI), the phenomenon of higher temperatures in urban land than the surrounding rural land, is commonly attributed to changes in biophysical properties of the land surface associated with urbanization. Here we provide evidence for a long-held hypothesis that the biogeochemical effect of urban aerosol or haze pollution is also a contributor to the UHI. Our results are based on satellite observations and urban climate model calculations. We find that a significant factor controlling the nighttime surface UHI across China is the urban-rural difference in the haze pollution level. The average haze contribution to the nighttime surface UHI is 0.7±0.3 K (mean±1 s.e.) for semi-arid cities, which is stronger than that in the humid climate due to a stronger longwave radiative forcing of coarser aerosols. Mitigation of haze pollution therefore provides a co-benefit of reducing heat stress on urban residents. PMID:27551987

  4. Haze over Beijing

    Science.gov (United States)

    2007-01-01

    Thick haze collected over the Beijing region in late March 2007. Earlier that month, the BBC News reported that an international team of scientists had documented how increasing pollution in China led to decreasing rainfall over the region. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard the Aqua satellite captured these images of the Beijing region on March 22, 2007. The top image is a 'true-color' picture, similar to a digital photo. The bottom, 'false-color,' image uses a combination of visible and infrared light to more clearly show vegetation, water, and clouds. Even sparse vegetation appears bright green, while water appears deep blue (bright blue when tinged with sediment). Clouds dominated by water droplets appear white, while clouds made of ice crystals appear light blue. The false-color image highlights water bodies, perhaps aqua-culture ponds, that are all but invisible in the true-color image, especially along the shores of the Bo Hai. While vegetation and water show up more clearly in the false-color image, haze is much more transparent. Although dingy gray haze dominates the true-color picture, it is all but invisible in the false-color view. The haze 'disappears' in the infrared-enhanced image because tiny haze particles do not reflect longer-wavelength infrared light very well, making this type of image useful for distinguishing haze from clouds. The bank of clouds in the upper right corner shows up clearly in both pictures. As China industrializes, factories, power plants, and automobiles all contribute to pollution in the region. In examining pollutants and rainfall, the team of scientists examined records covering more than 50 years, concluding that pollution decreased precipitation at Mount Hua near Xi'an in central China. They concluded that when conditions are so hazy that visibility is reduced to less than 8 kilometers (5 miles), hilly precipitation can drop by 30 to 50 percent. When moist air passes over mountains

  5. Blue enhanced light sources: opportunities and risks

    Science.gov (United States)

    Lang, Dieter

    2012-03-01

    Natural daylight is characterized by high proportions of blue light. By proof of a third type of photoreceptor in the human eye which is only sensitive in this spectral region and by subsequent studies it has become obvious that these blue proportions are essential for human health and well being. In various studies beneficial effects of indoor lighting with higher blue spectral proportions have been proven. On the other hand with increasing use of light sources having enhanced blue light for indoor illumination questions are arising about potential health risks attributed to blue light. Especially LED are showing distinct emission characteristics in the blue. Recently the French agency for food, environmental and occupational health & safety ANSES have raised the question on health issues related to LED light sources and have claimed to avoid use of LED for lighting in schools. In this paper parameters which are relevant for potential health risks will be shown and their contribution to risk factors will quantitatively be discussed. It will be shown how to differentiate between photometric parameters for assessment of beneficial as well as hazardous effects. Guidelines will be discussed how blue enhanced light sources can be used in applications to optimally support human health and well being and simultaneously avoid any risks attributed to blue light by a proper design of lighting parameters. In the conclusion it will be shown that no inherent health risks are related to LED lighting with a proper lighting design.

  6. Tapered photonic crystal fibers for blue-enhanced supercontinuum generation

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper;

    2012-01-01

    Tapering of photonic crystal fibers is an effective way of shifting the blue edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for enhancing the power in the blue edge.......Tapering of photonic crystal fibers is an effective way of shifting the blue edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for enhancing the power in the blue edge....

  7. Enhanced blue light shielding property of light-diffusion polycarbonate composites by CeO2-coated silicate microspheres

    Science.gov (United States)

    Zhao, Yu; Shi, Liyi; Tang, Anjie; Song, Na; Tang, Shengfu; Ding, Peng

    2015-07-01

    The CeO2 coated silicate microspheres (SMSs) core-shell particles (SMS-CeO2) were synthesized for enhancing blue light shielding property of polycarbonate (PC) composites. The structure analysis showed that CeO2 particles were homogenously coated on SMS by Ce-O-Si bonds. The optical analysis indicated that the transmittance of PC/SMS-CeO2 composites were enhanced to 63.2% from 42.9% for PC/SMS/CeO2 composites when 0.6 wt.% fillers were loaded, while there was no obvious influence on the haze of the composites. UV-Vis analysis showed that the absorbance at 450-nm wavelength of blue-light increased from 24% of PC/SMS to 50% of PC/SMS-CeO2 composites, while the absorbance at 650-nm wavelength of red-light was unchanged. These results indicated that the PC/SMS-CeO2 composites had blue light shielding property and better performance on transmitting other visible lights.

  8. Thermally enhanced blue light-emitting diode

    Science.gov (United States)

    Xue, Jin; Zhao, Yuji; Oh, Sang-Ho; Herrington, William F.; Speck, James S.; DenBaars, Steven P.; Nakamura, Shuji; Ram, Rajeev J.

    2015-09-01

    We investigate thermoelectric pumping in wide-bandgap GaN based light-emitting diodes (LEDs) to take advantage of high junction temperature rather than avoiding the problem of temperature-induced efficiency droop through external cooling. We experimentally demonstrate a thermally enhanced 450 nm GaN LED, in which nearly fourfold light output power is achieved at 615 K (compared to 295 K room temperature operation), with nearly no reduction in the wall-plug efficiency (i.e., electrical-optical energy conversion efficiency) at bias V active region by a combination of electrical work and Peltier heat (phonons) drawn from the lattice. In this optimal operating regime at 615 K, the LED injection current (3.26 A/cm2) is of similar magnitude to the operating point of common high power GaN based LEDs (5-35 A/cm2). This result suggests the possibility of removing bulky heat sinks in current high power LED products thus realizing a significant cost reduction for solid-state lighting.

  9. Titan Haze

    Science.gov (United States)

    Anderson, Carrie M.; West, Robert; Lavvas, Panayotis

    2011-01-01

    The Titan haze exerts a dominating influence on surface visibility and atmospheric radiative heating at optical and near-infrared wavelengths and our desire to understand surface composition and atmospheric dynamics provides a strong motivation to study the properties of the haze. Prior to the Cassini/Huygens missions the haze was known to be global in extent, with a hemispheric contrast asymmetry, with a complicated structure in the polar vortex region poleward of about 55 deg latitude, and with a distinct layer near 370 km altitude outside of the polar vortex at the time of the Voyager 2 flyby. The haze particles measured by the Pioneer and Voyager spacecraft were both highly polarizing and strongly forward scattering, a combination that seems to require an aggregation of small (several tens of nm radius) primary particles. These same properties were seen in the Cassini orbiter and Huygens Probe data. The most extensive set of optical measurements were made inside the atmosphere by the Descent Imager/Spectral Radiometer (DISR) instrument on the Huygens Probe. At the probe location as determined by the DISR measurements the average haze particle contained about 3000 primary particles whose radius is about 40 nm. Three distinct vertical regions were seen in the DISR data with differing particle properties. Refractive indices of the particles in the main haze layer resemble those reported by Khare et al. between O.3S and about 0.7 micron but are more absorbing than the Khare et al. results between 0.7 micron and the long-wavelength limit of the DISR spectra at 1.6 micron. These and other results are described by Tomasko et al., and a broader summary of results was given by Tomasko and West,. New data continue to stream in from the Cassini spacecraft. New data analyses and new laboratory and model results continue to move the field forward. Titan's 'detached' haze layer suffered a dramatic drop in altitude near equinox in 2009 with implications for the circulation

  10. Enhanced Deep Blue Aerosol Retrieval Algorithm: The Second Generation

    Science.gov (United States)

    Hsu, N. C.; Jeong, M.-J.; Bettenhausen, C.; Sayer, A. M.; Hansell, R.; Seftor, C. S.; Huang, J.; Tsay, S.-C.

    2013-01-01

    The aerosol products retrieved using the MODIS collection 5.1 Deep Blue algorithm have provided useful information about aerosol properties over bright-reflecting land surfaces, such as desert, semi-arid, and urban regions. However, many components of the C5.1 retrieval algorithm needed to be improved; for example, the use of a static surface database to estimate surface reflectances. This is particularly important over regions of mixed vegetated and non- vegetated surfaces, which may undergo strong seasonal changes in land cover. In order to address this issue, we develop a hybrid approach, which takes advantage of the combination of pre-calculated surface reflectance database and normalized difference vegetation index in determining the surface reflectance for aerosol retrievals. As a result, the spatial coverage of aerosol data generated by the enhanced Deep Blue algorithm has been extended from the arid and semi-arid regions to the entire land areas.

  11. Optimization of Tapered Photonic Crystal Fibers for Blue-Enhanced Supercontinuum Generation

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper;

    2012-01-01

    Tapering of photonic crystal fibers is an effective way of shifting the dispersive wavelength edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for blue-enhanced supercontinuum generation.......Tapering of photonic crystal fibers is an effective way of shifting the dispersive wavelength edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for blue-enhanced supercontinuum generation....

  12. Optimum PCF tapers for blue-enhanced supercontinuum sources

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Sørensen, Simon Toft; Larsen, Casper;

    2012-01-01

    Tapering of photonic crystal fibers has proven to be an effective way of blueshifting the dispersive wavelength edge of a supercontinuum spectrum down in the deep-blue. In this article we will review the state-of-the-art in fiber tapers, and discuss the underlying mechanisms of supercontinuum...... generation in tapers. We show, by introducing the concept of a group-acceleration mismatch, that for a given taper length, the downtapering section should be as long as possible to enhance the amount of blueshifted light. We also discuss the noise properties of supercontinuum generation in uniform and...... tapered fibers, and we demonstrate that the intensity noise at the spectral edges of the generated supercontinuum is at a constant level independent on the pump power in both tapered and uniform fibers....

  13. Seagrass restoration enhances "blue carbon" sequestration in coastal waters.

    Directory of Open Access Journals (Sweden)

    Jill T Greiner

    Full Text Available Seagrass meadows are highly productive habitats that provide important ecosystem services in the coastal zone, including carbon and nutrient sequestration. Organic carbon in seagrass sediment, known as "blue carbon," accumulates from both in situ production and sedimentation of particulate carbon from the water column. Using a large-scale restoration (>1700 ha in the Virginia coastal bays as a model system, we evaluated the role of seagrass, Zosteramarina, restoration in carbon storage in sediments of shallow coastal ecosystems. Sediments of replicate seagrass meadows representing different age treatments (as time since seeding: 0, 4, and 10 years, were analyzed for % carbon, % nitrogen, bulk density, organic matter content, and ²¹⁰Pb for dating at 1-cm increments to a depth of 10 cm. Sediment nutrient and organic content, and carbon accumulation rates were higher in 10-year seagrass meadows relative to 4-year and bare sediment. These differences were consistent with higher shoot density in the older meadow. Carbon accumulation rates determined for the 10-year restored seagrass meadows were 36.68 g C m⁻² yr⁻¹. Within 12 years of seeding, the restored seagrass meadows are expected to accumulate carbon at a rate that is comparable to measured ranges in natural seagrass meadows. This the first study to provide evidence of the potential of seagrass habitat restoration to enhance carbon sequestration in the coastal zone.

  14. Establishment of blue mussel beds to enhance fish habitats

    DEFF Research Database (Denmark)

    Kristensen, Louise Dahl; Stenberg, Claus; Støttrup, Josianne; Poulsen, Louise K.; Christensen, Helle Torp; Dolmer, Per; Landes, Anja; Røjbek, Maria; Thorsen, S.W.; Deurs, Mads Anker van; Grønkjær, Peter

    2015-01-01

    study aimed to establish blue mussel beds (Mytilus edulis) to increase structural complexity and increase the abundance of fish and epifauna in Nørrefjord. It was expected that the mussels would improve water transparency and increase the depth range and coverage of eelgrass (Zostera marina). New...... methods for mussel production and -bed construction were investigated in collaboration with local volunteer fishermen. The effect of the artificial mussel beds was most evident on a small scale. Video observations directly at the beds (Impact area) demonstrated increased biodiversity and a three times...... higher abundance of mesopredator fish compared to the Control area. Water clarity and eelgrass coverage were unchanged. Two methods for establishing mussel beds were tested. A total of 44 tons of blue mussels were produced and established in beds over an area of 121,000 m2. Production of blue mussels...

  15. Fog and Haze in California's San Joaquin Valley

    Science.gov (United States)

    2001-01-01

    This illustration features images of southern California and southwestern Nevada acquired on January 3, 2001 (Terra orbit 5569), and includes data from three of MISR's nine cameras. The San Joaquin Valley, which comprises the southern extent of California's Central Valley, covers much of the viewed area. Also visible are several of the Channel Islands near the bottom, and Mono and Walker Lakes, which stand out as darker patches near the top center, especially in the vertical and backward oblique images. Near the lower right of each image is the Los Angeles Basin, with the distinctive chevron shape of the Mojave Desert to its north.The Central Valley is a well-irrigated and richly productive agricultural area situated between the Coast Range and the snow-capped Sierra Nevadas. During the winter, the region is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected sunlight, dramatic differences in the MISR images are apparent as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, the pervasive haze that fills most of the valley is only slightly visible in the vertical view. At the oblique angles, the haze is highly distinguishable against the land surface background, particularly in the forward-viewing direction. Just above image center, the forward view also reveals bluish-tinged plumes near Lava Butte in Sequoia National Forest, where the National Interagency Coordination Center reported an active forest fire.The changing surface visibility in the multi-angle data allows us to derive the amount of atmospheric haze. In the lower right quadrant is a map of haze amount determined from automated processing of the MISR imagery. Low amounts of haze are shown in blue, and a variation in hue through shades of green, yellow, and red indicates progressively larger amounts of airborne particulates. Due to the topographically

  16. Methylene blue-enhanced arthroscopic resection of dorsal wrist ganglions.

    Science.gov (United States)

    Lee, Byung Joo; Sawyer, Gregory A; Dasilva, Manuel F

    2011-12-01

    The ganglion is the most common soft tissue mass of the hand and wrist. Over the past 10 to 15 years, there has been a growing interest in arthroscopic treatment of dorsal wrist ganglions. Proposed advantages of arthroscopy include greater motion (particularly wrist flexion), improved cosmesis, and potential to identify/treat other intra-articular pathology. Despite the documented clinical success of arthroscopic ganglion excision, limitations include inconsistent identification of the ganglion stalk. Our described technique offers a means by which to improve visualization of the ganglion stalk intra-articularly to produce a more effective and efficient arthroscopic ganglion excision. During the procedure, a small volume of methylene blue solution is injected into the cyst. Its communication with the joint is apparent arthroscopically, thus identifying the location of the stalk. With the ability to precisely identify the ganglion stalk using an injection of methylene blue, the surgeon can direct the arthroscopic debridement toward the appropriate pathologic tissue. Unnecessary debridement of uninvolved tissue can be avoided with the technique. This also allows for optimal portal placement and, in particular, indicates whether a midcarpal portal should be employed. This should result in fewer recurrences, decreased operative time, and less iatrogenic injury. PMID:22105637

  17. Enhancement of elimination of internally deposited radiocesium in human being by prussian blue

    International Nuclear Information System (INIS)

    The paper reported the results about observation of enhancement of elimination of 137Cs, 134Cs by administration of prussian blue in Chinese subjects who were internally contaminated with radiocesium released from the Chernobyl accident. The prussian blue was administrated on the 114th and 272nd day after contamination. 1.0 g of prussian blue was given 3 times per day, for a six day course. Three courses were given with an interval of a 6 days between two courses. The results indicated that biological half-time of 137Cs and 134Cs shorten from 54 - 123 days and 42 - 117 days during control period to 28 - 65 days and 23 - 69 days during administration period, respectively. The shortening of biological half-time resulted in 2 - 21% decrease of accumulative activity of radiocesium in body as compared with that during the same period when prussian blue was not given

  18. Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

    Directory of Open Access Journals (Sweden)

    I. Abdul Rahman

    2014-01-01

    Full Text Available ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment.

  19. Sulfate Formation Enhanced by a Cocktail of High NOx, SO2, Particulate Matter, and Droplet pH during Haze-Fog Events in Megacities in China: An Observation-Based Modeling Investigation.

    Science.gov (United States)

    Xue, Jian; Yuan, Zibing; Griffith, Stephen M; Yu, Xin; Lau, Alexis K H; Yu, Jian Zhen

    2016-07-19

    In recent years in a few Chinese megacities, fog events lasting one to a few days have been frequently associated with high levels of aerosol loading characterized by high sulfate (as high as 30 μg m(-3)), therefore termed as haze-fog events. The concomitant pollution characteristics include high gas-phase mixing ratios of SO2 (up to 71 ppbv) and NO2 (up to 69 ppbv), high aqueous phase pH (5-6), and smaller fog droplets (as low as 2 μm), resulting from intense emissions from fossil fuel combustion and construction activities supplying abundant Ca(2+). In this work, we use an observation-based model for secondary inorganic aerosols (OBM-SIA) to simulate sulfate formation pathways under conditions of haze-fog events encountered in Chinese megacities. The OBM analysis has identified, at a typical haze-fogwater pH of 5.6, the most important pathway to be oxidation of S(IV) by dissolved NO2, followed by the heterogeneous reaction of SO2 on the aerosol surface. The aqueous phase oxidation of S(IV) by H2O2 is a very minor formation pathway as a result of the high NOx conditions suppressing H2O2 formation. The model results indicate that the unique cocktail of high fogwater pH, high concentrations of NO2, SO2, and PM, and small fog droplets are capable of greatly enhancing sulfate formation. Such haze-fog conditions could lead to rapid sulfate production at night and subsequently high PM2.5 in the morning when the fog evaporates. Sulfate formation is simulated to be highly sensitive to fogwater pH, PM, and precursor gases NO2 and SO2. Such insights on major contributing factors imply that reduction of road dust and NOx emissions could lessen PM2.5 loadings in Chinese megacities during fog events. PMID:27331615

  20. Broken Pledges: The Deadly Rite of Hazing.

    Science.gov (United States)

    Nuwer, Hank

    The practice of hazing in college fraternities, sororities, high school clubs, professional societies, business, the military, and secret societies is investigated. Through the retelling of actual stories involving hazing, the book addresses the questions of why men and women haze and allow themselves to be hazed, how the problems of hazing can be…

  1. Enhanced visible light photocatalytic degradation of methylene blue by F-doped TiO2

    International Nuclear Information System (INIS)

    Graphical abstract: F-doped TiO2 is synthesized using a modified sol–gel method for visible photocatalytic degradation of MB with a high degradation rate of 91%. - Highlights: • F-doped TiO2 are synthesized using a modified sol–gel method. • The photocatalytic degradation of methylene blue by F-doped TiO2 is investigated. • A high methylene blue degradation rate of 91% is achieved under visible light irradiation. - Abstract: F-doped TiO2 (F-TiO2) were successfully synthesized using a modified sol–gel method. The morphologies, structures, and photocatalytic performance in the degradation of methylene blue (MB) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV–vis absorption spectroscopy, and electrochemical impedance spectra, respectively. The results show that F-TiO2 exhibits an enhanced photocatalytic performance in the degradation of MB with a maximum degradation rate of 91% under visible light irradiation as compared with pure TiO2 (32%). The excellent photocatalytic activity is due to the contribution from the increased visible light absorption, promoted separation of photo-generated electrons and holes as well as enhanced photocatalytic oxidizing species with the doping of F in TiO2

  2. Feasibility of Haze Governance Based on Carbon Sink Mode

    Institute of Scientific and Technical Information of China (English)

    Jie; HE; Quanquan; WANG

    2015-01-01

    In recent years,there are research findings of haze formation in various fields of academic circle. It has proved that causes of haze take on diverse characteristics. Thus,from both the natural and human perspective,haze governance should be diverse. Research conclusions on causes of haze formation mainly focus on special geographical structure,and meteorological factors such as relatively stable atmosphere,high rate of calm wind,high relative humidity and temperature of air,and human factors such as industrial pollution,automotive exhaust emissions,aerosol pollution,eutrophication of soil water,and change of city underlying surface. Carbon sink mode is a new channel for haze governance.In carbon sink mode,it is feasible to regulate relative humidity and temperature in air,enhance global wind,and reduce fine particles and microorganisms of air pollution,so as to reduce haze pollution. Besides,China’s special potential of carbon sink market makes it possible to govern haze on the base of carbon sink.

  3. Effectiveness of Alkali-Acid Treatment in Enhancement the Adsorption Capacity for Rice Straw: The Removal of Methylene Blue Dye

    OpenAIRE

    Nady A. Fathy; El-Shafey, Ola I.; Khalil, Laila B.

    2013-01-01

    The effectiveness of alkali-acid modification in enhancement the adsorption capacity of rice straw (RS) for removing a basic dye was studied. The obtained adsorbents were characterized by slurry pH, pHPZC, iodine number, methylene blue number, FTIR, and SEM analyses. Adsorption of methylene blue (MB) was described by the Langmuir, Freundlich, Tempkin, and Redlich-Peterson isotherm models. Effects of contact time, initial concentration of MB dye, pH of solution, adsorbent dose, salt concentrat...

  4. Doping of Co into V2O5 nanoparticles enhances photodegradation of methylene blue

    International Nuclear Information System (INIS)

    Highlights: • Co-doped V2O5 nanoparticles are synthesized by thermal decomposition method. • The nanoparticles are used as photocatalyst for the first time. • Doped samples exhibited enhanced photodegradation property. • Observed enhanced activity is due to Co and plausible mechanism has been proposed. - Abstract: V2O5 nanoparticles doped with different amounts of (x = 2%, 5% and 10%) Co was successfully synthesized by thermal decomposition method with the purpose of enhancing their photodegradation performance under visible light irradiation. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman, UV–Vis, photoluminescence (PL) spectroscopy, field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HR-TEM). The photodegradation property of the prepared pure V2O5 and Co-V2O5 nanoparticles were investigated by using aqueous solution of methylene blue (MB) under visible light irradiation. The obtained results clearly indicated that the amount of Co has significant effect on the photodegradation of MB. Particularly, 10%Co-V2O5 nanoparticles exhibits enhanced photodegradation property than the pure, 2% and 5%Co-doped samples. A plausible mechanism was put forth for such significant improvements in photodegradation performance of Co-V2O5

  5. Electroluminescence enhancement in blue phosphorescent organic light-emitting diodes based on different hosts

    Science.gov (United States)

    Zhang, Wei; Zhang, Fang-hui; Huang, Jin; Zhang, Mai-li; Ma, Ying

    2013-09-01

    Blue phosphorescent organic light-emitting diodes (OLEDs) are fabricated by utilizing the hole transport-type host material of 1,3-bis(carbazol-9-yl)benzene (MCP) combined with the electron transport-type host material of 1,3-bis (triphenylsilyl) benzene (UGH3) with the ratios of 1:0, 8:2 and 6:4, and doping with blue phosphorescent dopant of bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium (FIrpic). The device with an optimum concentration proportion of MCP:UGH3 of 8:2 exhibits the maximum current efficiency of 19.18 cd/A at luminance of 35.71 cd/m2 with maintaining Commission Internationale de L'Eclairage (CIE) coordinates of (0.1481, 0.2695), which is enhanced by 35.7% compared with that of 1:0 with (0.1498, 0.2738). The improvements are attributed to the effective carrier injection and transport in emitting layer (EML) because of mixed host materials. In addition, electron and exciton are confined in the EML, and 4,4',4″-Tris(carbazol-9-yl)-triphenylamine (TCTA) and Di-[4-(N,N-ditolyl-amino)-phenyl]cyclohexane (TAPC) have the high lowest unoccupied molecular orbital (LUMO) energy level and triplet exiton energy.

  6. Enhanced photocatalytic degradation of methylene blue by metal-modified silicon nanowires

    International Nuclear Information System (INIS)

    Highlights: • SiNWs modified with Pd, Au and Pt were used as photocatalysts to degrade MB. • Yield of photodegardation increases with UV irradiation time. • SiNWs modified with Pd nanoparticles show the best photocatalytic activity. • A degradation of 97% was obtained after 200 min of UV irradiation. - Abstract: Silicon nanowires (SiNWs) modified with Au, Pt and Pd nanoparticles were used as heterogeneous photocatalysts for the photodegradation of methylene blue in water under UV light irradiation. The modification of SiNWs was carried out by deposition of metal nanoparticles using the electroless metal deposition (EMD) technique. The effect of metal nanoparticles deposition time on the photocatalytic activity was studied. It was found that the photocatalytic activity of modified SiNWs was enhanced when the deposition time of metal nanoparticles was increased. In addition of modified SiNWs with Pt, Au and Pd nanoparticles, oxidized silicon substrate (Ox-Si), oxidized silicon nanowires (Ox-SiNWs) and hydrogen-terminated silicon nanowires (H-SiNWs) were also evaluated for the photodegradation of methylene blue

  7. Enhanced photocatalytic degradation of methylene blue by metal-modified silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Brahiti, N., E-mail: dihiabrahiti@yahoo.fr [Centre de Recherche en Technologie des Semi-conducteurs pour l' Energétique (CRTSE), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 Merveilles, Alger (Algeria); Université Mouloud MAMMERI de TiziOuzou, Département de Physique, Bastos (Algeria); Hadjersi, T., E-mail: hadjersi@gmx.com [Centre de Recherche en Technologie des Semi-conducteurs pour l' Energétique (CRTSE), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 Merveilles, Alger (Algeria); Menari, H. [Centre de Recherche en Technologie des Semi-conducteurs pour l' Energétique (CRTSE), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 Merveilles, Alger (Algeria); Amirouche, S.; El Kechai, O. [Université Mouloud MAMMERI de TiziOuzou, Département de Physique, Bastos (Algeria)

    2015-02-15

    Highlights: • SiNWs modified with Pd, Au and Pt were used as photocatalysts to degrade MB. • Yield of photodegardation increases with UV irradiation time. • SiNWs modified with Pd nanoparticles show the best photocatalytic activity. • A degradation of 97% was obtained after 200 min of UV irradiation. - Abstract: Silicon nanowires (SiNWs) modified with Au, Pt and Pd nanoparticles were used as heterogeneous photocatalysts for the photodegradation of methylene blue in water under UV light irradiation. The modification of SiNWs was carried out by deposition of metal nanoparticles using the electroless metal deposition (EMD) technique. The effect of metal nanoparticles deposition time on the photocatalytic activity was studied. It was found that the photocatalytic activity of modified SiNWs was enhanced when the deposition time of metal nanoparticles was increased. In addition of modified SiNWs with Pt, Au and Pd nanoparticles, oxidized silicon substrate (Ox-Si), oxidized silicon nanowires (Ox-SiNWs) and hydrogen-terminated silicon nanowires (H-SiNWs) were also evaluated for the photodegradation of methylene blue.

  8. High-pressure homogenization associated hydrothermal process of palygorskite for enhanced adsorption of Methylene blue

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Palygorskite was modified by a homogenization associated hydrothermal process. • The crystal bundles of PAL were disaggregated efficiently after modification. • The adsorption of palygorskite for Methylene blue was greatly enhanced. • MB-loaded palygorskite exhibits excellent resistance to acid and alkali solution. - Abstract: Palygorskite (PAL) was modified by a high-pressure homogenization assisted hydrothermal process. The effects of modification on the morphology, structure and physicochemical properties of PAL were systematically investigated by Field-emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FTIR), Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD) and Zeta potential analysis techniques, and the adsorption properties were systematically evaluated using Methylene blue (MB) as the model dye. The results revealed that the crystal bundles were disaggregated and the PAL nanorods became more even after treated via associated high-pressure homogenization and hydrothermal process, and the crystal bundles were dispersed as nanorods. The intrinsic crystal structure of PAL was remained after hydrothermal treatment, and the pore size calculated by the BET method was increased. The adsorption properties of PAL for MB were evidently improved (from 119 mg/g to 171 mg/g) after modification, and the dispersion of PAL before hydrothermal reaction is favorable to the adsorption. The desorption evaluation confirms that the modified PAL has stronger affinity with MB, which is benefit to fabricate a stable organic–inorganic hybrid pigment

  9. High-pressure homogenization associated hydrothermal process of palygorskite for enhanced adsorption of Methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhifang [Center of Eco-materials and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Wang, Wenbo [Center of Eco-materials and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); R& D Center of Xuyi Attapulgite Applied Technology, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Xuyi 211700 (China); Wang, Aiqin, E-mail: aqwang@licp.cas.cn [Center of Eco-materials and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); R& D Center of Xuyi Attapulgite Applied Technology, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Xuyi 211700 (China)

    2015-02-28

    Graphical abstract: - Highlights: • Palygorskite was modified by a homogenization associated hydrothermal process. • The crystal bundles of PAL were disaggregated efficiently after modification. • The adsorption of palygorskite for Methylene blue was greatly enhanced. • MB-loaded palygorskite exhibits excellent resistance to acid and alkali solution. - Abstract: Palygorskite (PAL) was modified by a high-pressure homogenization assisted hydrothermal process. The effects of modification on the morphology, structure and physicochemical properties of PAL were systematically investigated by Field-emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FTIR), Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD) and Zeta potential analysis techniques, and the adsorption properties were systematically evaluated using Methylene blue (MB) as the model dye. The results revealed that the crystal bundles were disaggregated and the PAL nanorods became more even after treated via associated high-pressure homogenization and hydrothermal process, and the crystal bundles were dispersed as nanorods. The intrinsic crystal structure of PAL was remained after hydrothermal treatment, and the pore size calculated by the BET method was increased. The adsorption properties of PAL for MB were evidently improved (from 119 mg/g to 171 mg/g) after modification, and the dispersion of PAL before hydrothermal reaction is favorable to the adsorption. The desorption evaluation confirms that the modified PAL has stronger affinity with MB, which is benefit to fabricate a stable organic–inorganic hybrid pigment.

  10. Magnetic enhancement of photoluminescence from blue-luminescent graphene quantum dots

    Science.gov (United States)

    Chen, Qi; Shi, Chentian; Zhang, Chunfeng; Pu, Songyang; Wang, Rui; Wu, Xuewei; Wang, Xiaoyong; Xue, Fei; Pan, Dengyu; Xiao, Min

    2016-02-01

    Graphene quantum-dots (GQDs) have been predicted and demonstrated with fascinating optical and magnetic properties. However, the magnetic effect on the optical properties remains experimentally unexplored. Here, we conduct a magneto-photoluminescence study on the blue-luminescence GQDs at cryogenic temperatures with magnetic field up to 10 T. When the magnetic field is applied, a remarkable enhancement of photoluminescence emission has been observed together with an insignificant change in circular polarization. The results have been well explained by the scenario of magnetic-field-controlled singlet-triplet mixing in GQDs owing to the Zeeman splitting of triplet states, which is further verified by temperature-dependent experiments. This work uncovers the pivotal role of intersystem crossing in GQDs, which is instrumental for their potential applications such as light-emitting diodes, photodynamic therapy, and spintronic devices.

  11. Microstructure and blue photoluminescence enhancement of silicon nanoporous pillar array embedded in ferroelectric barium strontium titanate

    International Nuclear Information System (INIS)

    A silicon nanoporous pillar array (Si-NPA) with micrometer/nanometer hierarchical structure was fabricated by hydrothermal etching, followed by spin-coating barium strontium titanate (BST) on Si-NPA substrate. The photoluminescence (PL) spectra of the Si-NPA and BST/Si-NPA thin film were investigated. The emission band of freshly prepared Si-NPA located at ∼630 nm, and a blueshift at ∼425 nm as well as degradation in intensity after annealing at 600 deg. C for 1 h was observed, which might be explained by a quantum confinement effect model. BST ferroelectric material provided a static-electric field and induced the excited carriers in Si-NPA to migrate toward the opposite direction and recombine in an interfacial oxide layer. Therefore, BST enhanced blue emission of Si-NPA as well as passivated Si-NPA

  12. Blue-enhanced supercontinuum generation pumped by a giant-chirped SESAM mode-locked fiber laser

    Science.gov (United States)

    Gao, Shoufei; Wang, Yingying; Sun, Ruoyu; Jin, Dongchen; Liu, Jiang; Wang, Pu

    2016-08-01

    We report on a blue-enhanced supercontinuum generation pumped by a giant-chirped SESAM mode-locked 1064-nm fiber laser, in which the giant chirp is introduced by a piece of 3.5-km single-mode fiber outside of the cavity. The giant-chirped pump source with 2.2-nm spectral bandwidth and 186-ps pulse width is used to enhance dispersive waves generation in blue wavelength. An extremely wide optical spectrum with a broad 3-dB spectral bandwidth of 311 nm (from 446 to 757 nm) and a maximum spectral power density of 4 mW/nm at 464 nm is obtained.

  13. Potential for use of methylene blue index testing to enhance geotechnical characterization of oil sands ores and tailings

    Energy Technology Data Exchange (ETDEWEB)

    Boxill, Lois [SRK Consulting (Canada)

    2011-07-01

    At the CONRAD conference held in Edmonton in 2011, clay scientist expressed their concern over the variability of clay structures and its impact both on oil sands ores and on tailings. This paper discusses the potential for using methylene blue index testing to enhance geotechnical understanding of the impact of the cation exchange capacity of clay present in oil sands ores and both solid and fluid components of the tailings stream. A description of the methylene blue index test procedure is provided. This process is most commonly used for characterization in the oil sands industry. The requirements for obtaining consistency in the test results are discussed. The test is often used to enhance geotechnical characterization of clays in other areas. The potential for developing correlations between methylene blue index test results and other geotechnical parameters is also discussed. It can be concluded from the study that geotechnical data on soil indicate the effect of clay minerals on the overall plasticity of the soil.

  14. Did the widespread haze pollution over China increase during the last decade? A satellite view from space

    Science.gov (United States)

    Tao, Minghui; Chen, Liangfu; Wang, Zifeng; Wang, Jun; Tao, Jinhua; Wang, Xinhui

    2016-05-01

    Widespread haze layers usually cover China like low clouds, exerting marked influence on air quality and regional climate. With recent Collection 6 MODIS Deep Blue aerosol data in 2000–2015, we analyzed the trends of regional haze pollution and the corresponding influence of atmospheric circulation in China. Satellite observations show that regional haze pollution is mainly concentrated in northern and central China. The annual frequency of regional haze in northern China nearly doubles between 2000 and 2006, increasing from 30–50 to 80–90 days. Though there is a marked decrease in annual frequency during 2007–2009 due to both reduction of anthropogenic emissions and changes of meteorological conditions, regional pollution increases slowly but steadily after 2009, and maintains at a high level of 70–90 days except for the sudden decrease in 2015. Generally, there is a large increase in the number of regional-scale haze events during the last decade. Seasonal frequency of regional haze exhibits distinct spatial and temporal variations. The increasing winter haze events reach a peak in 2014, but decrease strongly in 2015 due partly to synoptic conditions that are favorable for dispersion. Trends of summer regional haze pollution are more sensitive to changes of atmospheric circulation. Our results indicate that the frequency of regional haze events is associated not only with the strength of atmospheric circulation, but also with its direction and position, as well as variations in anthropogenic emissions.

  15. Poly(vinylpyrrolidone) supported copper nanoclusters: glutathione enhanced blue photoluminescence for application in phosphor converted light emitting devices

    Science.gov (United States)

    Wang, Zhenguang; Susha, Andrei S.; Chen, Bingkun; Reckmeier, Claas; Tomanec, Ondrej; Zboril, Radek; Zhong, Haizheng; Rogach, Andrey L.

    2016-03-01

    Poly(vinylpyrrolidone) supported Cu nanoclusters were synthesized by reduction of Cu(ii) ions with ascorbic acid in water, and initially showed blue photoluminescence with a quantum yield of 8%. An enhancement of the emission quantum yield has been achieved by treatment of Cu clusters with different electron-rich ligands, with the most pronounced effect (photoluminescence quantum yield of 27%) achieved with glutathione. The bright blue emission of glutathione treated Cu NCs is fully preserved in the solid state powder, which has been combined with commercial green and red phosphors to fabricate down-conversion white light emitting diodes with a high colour rendering index of 92.Poly(vinylpyrrolidone) supported Cu nanoclusters were synthesized by reduction of Cu(ii) ions with ascorbic acid in water, and initially showed blue photoluminescence with a quantum yield of 8%. An enhancement of the emission quantum yield has been achieved by treatment of Cu clusters with different electron-rich ligands, with the most pronounced effect (photoluminescence quantum yield of 27%) achieved with glutathione. The bright blue emission of glutathione treated Cu NCs is fully preserved in the solid state powder, which has been combined with commercial green and red phosphors to fabricate down-conversion white light emitting diodes with a high colour rendering index of 92. Electronic supplementary information (ESI) available: The optical spectra of control experiments for Cu NC synthesis, optimization of the reaction conditions, and spectra for LEDs chips and blue LEDs. See DOI: 10.1039/c6nr00806b

  16. Micellar-enhanced ultrafiltration of cadmium and methylene blue in synthetic wastewater using SDS

    International Nuclear Information System (INIS)

    Single and simultaneous removal of Cd2+ and methylene blue (MB) with sodium dodecyl sulfate (SDS) by micellar-enhanced ultrafiltration under different experimental conditions was investigated. In single removal process, with initial SDS concentration increasing, the removal efficiency of Cd2+ and MB kept increasing and then decreased. When the initial concentrations of SDS and Cd2+ were 1.0 cmc and 50 mg L-1, respectively, the maximum removal efficiency of Cd2+ was obtained as 99.2%. Removal efficiency of MB could achieve more than 99.9% with initial SDS concentration below 2.0 cmc. As compared with single Cd2+ removal, the removal efficiency of Cd2+ in the presence of MB was slightly higher with initial SDS concentration below 1.0 cmc, while decreased with the SDS concentration above 1.0 cmc. The maximum removal efficiency of Cd2+ was 98.8% when initial concentrations of SDS and MB were 1.0 cmc and 4 mg L-1, respectively. The removal efficiency of MB in the presence of Cd2+ could achieve higher than 96.5%, which was only 3.4% less than the optimum result of the single removal. Meanwhile, effect of pH on removal efficiency of Cd2+ was more significant than that of MB.

  17. Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of gliomas in optical images

    Science.gov (United States)

    Wirth, Dennis; Snuderl, Matija; Curry, William; Yaroslavsky, Anna

    2014-09-01

    Contrast agents have shown to be useful in the detection of cancers. The goal of this study was to compare enhancement of brain cancer contrast using reflectance and fluorescence confocal imaging of two fluorophores, methylene blue (MB) and demeclocycline (DMN). MB absorbs light in the red spectral range and fluoresces in the near-infrared. It is safe for in vivo staining of human skin and breast tissue. However, its safety for staining human brain is questionable. Thus, DMN, which absorbs light in the violet spectral range and fluoresces between 470 and 570 nm, could provide a safer alternative to MB. Fresh human gliomas, obtained from surgeries, were cut in half and stained with aqueous solutions of MB and DMN, respectively. Stained tissues were imaged using multimodal confocal microscopy. Resulting reflectance and fluorescence optical images were compared with hematoxylin and eosin histopathology, processed from each imaged tissue. Results indicate that images of tissues stained with either stain exhibit comparable contrast and resolution of morphological detail. Further studies are required to establish the safety and efficacy of these contrast agents for use in human brain.

  18. Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of brain neoplasms

    Science.gov (United States)

    Wirth, Dennis J.

    Brain tumors cause significant morbidity and mortality even when benign. Completeness of resection of brain tumors has been associated with better quality of life. However, that is often difficult to accomplish. The goal of this study was to evaluate the feasibility of using contrast enhanced multimodal confocal imaging for intraoperative detection of brain neoplasms. Different types of benign and malignant, primary and metastatic brain tumors, stained with Methylene Blue (MB) as a contrast agent, were imaged. MB is a traditional histopathologic stain that absorbs light in the red spectral range and fluoresces in the near infrared. It is FDA-approved for in vivo staining of human skin and breast tissue. Optical images showed good correlation with histopathology, demonstrating the potential of contrast enhanced multimodal confocal imaging for intraoperative detection of brain neoplasms ex vivo. However, the safety of MB for staining human brain in vivo is questionable. Demeclocycline (DMN), an antibiotic of the tetracycline family, has shown to be effective in differentiating normal from cancerous tissue in various organs. DMN is a fluorophore, which absorbs light in the violet spectral range and has a broad emission band covering green and yellow wavelengths. It is commonly used to treat infection and inflammatory disorders, and could provide a safer alternative to MB. To test this hypothesis, fresh excess human brain tissues were bisected and stained with aqueous solutions of either MB or DMN and then imaged. Reflectance and fluorescence images acquired from tissues stained with the two dyes were compared, and correlated with processed H&E histopathology. Comparison showed similar staining patterns and contrast of diagnostic features in glioblastomas, stained using either MB or DMN. The results show potential of both MB and DMN for the intraoperative detection of microscopic nests of brain neoplasms. Further studies will establish safety and efficacy of these

  19. Concentrations and chemical compositions of fine particles (PM2.5) during haze and non-haze days in Beijing

    Science.gov (United States)

    Zhang, Yang; Huang, Wei; Cai, Tianqi; Fang, Dongqing; Wang, Yuqin; Song, Jian; Hu, Min; Zhang, Yuanxun

    2016-06-01

    To investigate the chemical properties of PM2.5 and put forward reasonable control measures, daily samples of PM2.5 were collected at an urban site in Beijing from August 4 to September 3 of 2012 using two 2-channel samplers. Chemical analysis was conducted for eight water soluble inorganic ions (WSII, including Na+, NH4+, K+, Mg2 +, Ca2 +, Cl-, NO3-, and SO42 -), organic carbon (OC) and elementary carbon (EC). PM2.5 concentrations ranged from 8.8 to 218.6 μg m- 3, with an average concentration of 80.6 ± 57.3 μg m- 3. WSII, the most dominant PM2.5 constituents contributing 60 ± 18% of its mass, ranged from 3.1 to 172.2 μg m- 3. SO42 -, NO3-, and NH4+ dominated WSII (90 ± 28%) and their concentrations were 1.3-105.7 μg m- 3, 0.5-52.7 μg m- 3 and 0.3-33.5 μg m- 3, respectively. The concentrations of OC and EC were 3.0-28.8 μgC m- 3 and 0.8-7.4 μgC m- 3, constituting 17.6% and 4.9% of PM2.5, respectively. Three serious pollution episodes (haze days) occurred during the campaign. PM2.5 and its chemical species showed substantial increases during haze episodes. The greater enhancement factors for SO42 - (4.5), NO3- (4.0), and NH4+ (4.2) during haze days compared to non-haze days were obtained, suggesting that these secondary inorganic ions play important roles in the formation of haze. The average ratio of NO3-/SO42 - was 0.52. Ion balance calculations showed that PM2.5 samples were acidic during haze periods and close to neutral during non-haze days. Correlation analysis between the major ions was conducted and the results suggested that the main forms of NH4+ might be (NH4)2SO4. In addition, the variations between haze days and non-haze days for OC, EC, and the ratio of OC/EC were discussed.

  20. A new method of satellite-based haze aerosol monitoring over the North China Plain and a comparison with MODIS Collection 6 aerosol products

    Science.gov (United States)

    Yan, Xing; Shi, Wenzhong; Luo, Nana; Zhao, Wenji

    2016-05-01

    With worldwide urbanization, hazy weather has been increasingly frequent, especially in the North China Plain. However, haze aerosol monitoring remains a challenge. In this paper, MODerate resolution Imaging Spectroradiometer (MODIS) measurements were used to develop an enhanced haze aerosol retrieval algorithm (EHARA). This method can work not only on hazy days but also on normal weather days. Based on 12-year (2002-2014) Aerosol Robotic Network (AERONET) aerosol property data, empirical single scattering albedo (SSA) and asymmetry factor (AF) values were chosen to assist haze aerosol retrieval. For validation, EHARA aerosol optical thickness (AOT) values, along with MODIS Collection 6 (C6) dark-pixel and deep blue aerosol products, were compared with AERONET data. The results show that the EHARA can achieve greater AOT spatial coverage under hazy conditions with a high accuracy (73% within error range) and work a higher resolution (1-km). Additionally, this paper presents a comprehensive discussion of the differences between and limitations of the EHARA and the MODIS C6 DT land algorithms.

  1. Magnetic field assisted Fenton reactions for the enhanced degradation of methyl blue

    Institute of Scientific and Technical Information of China (English)

    Xiao Long Hao; Lu Yi Zou; Guang Sheng Zhang; Yi Bo Zhang

    2009-01-01

    Magnetic field was tentatively introduced into Fenton reactions system for the degradation and discoloration of methyl blue as the represent of organic chemical dye, which was a bio-refractory organic pollutant in industry wastewater. It was found that under optimal Fenton reaction conditions, with the assistant of magnetic field in Fenton reactions, the degradation rate of methyl blue, the decomposition rate of H2O2 and the conversion rate of Fe2+ were accelerated, the extent of them would be improved by the increase of magnetic field intensity. Meanwhile, the mineralization of methyl blue (CODcr) was improved by over 10% with magnetic fiold.

  2. Postpartum Blues

    Medline Plus

    Full Text Available ... baby blues). What are the baby blues? The word "blues" is not really correct since women with ... baby blues). What are the baby blues? The word "blues" is not really correct since women with ...

  3. Enhancement of the blue photoluminescence intensity for the porous silicon with HfO2 filling into microcavities.

    Science.gov (United States)

    Jiang, Ran; Du, Xianghao; Sun, Weideng; Han, Zuyin; Wu, Zhengran

    2015-01-01

    With HfO2 filled into the microcavities of the porous single-crystal silicon, the blue photoluminescence was greatly enhanced at room temperature. On one hand, HfO2 contributes to the light emission with the transitions of the defect levels for oxygen vacancy. On the other hand, the special filling-into-microcavities structure of HfO2 leads to the presence of ferroelectricity, which greatly enhances the blue emission from porous silicon. Since both HfO2 and Si are highly compatible with Si-based electronic industry, combined the low-cost and convenient process, the HfO2-filled porous Si shows a promising application prospect. PMID:26503804

  4. Facile synthesis and step by step enhancement of blue photoluminescence from Ag-doped ZnS quantum dots

    OpenAIRE

    Sahai, Sonal; Husain, Mushahid; Shanker, Virendra; Singh, Nahar; Haranath, D.

    2012-01-01

    Our results pertaining to the step by step enhancement of photoluminescence (PL) intensity from ZnS:Ag,Al quantum dots (QDs) are presented. Initially, these QDs were synthesized using a simple co-precipitation technique involving a surfactant, polyvinylpyrrolidone (PVP), in de-ionised water. It was observed that the blue PL originated from ZnS:Ag,Al QDs was considerably weak and not suitable for any practical display application. Upon UV (365 nm) photolysis, the PL intensity augmented to ~170...

  5. Tree shelters and weed control enhance growth and survival of natural blue oak seedlings

    OpenAIRE

    McCreary, Douglas D.; Tietje, William; Davy, Josh; Larsen, Royce E.; Doran, Morgan; Flavell, Dustin; Garcia, Sergio

    2011-01-01

    Blue oak is regenerating poorly in portions of its range. Techniques to artificially regenerate trees by collecting acorns, growing seedlings in a nursery and then planting them are effective but costly. Improving the growth and survival rate of existing volunteer seedlings in woodlands could be more cost efficient and therefore more widely used. We tested tree shelters and weed control treatments over 3 years at six woodland sites to evaluate whether they helped blue oak seedlings grow into ...

  6. Visible-light-induced blue MoO3–C3N4 composite with enhanced photocatalytic activity

    International Nuclear Information System (INIS)

    Highlights: • Novel MoO3–C3N4 composite was prepared by a mixing-calcination method. • The MoO3–C3N4 composite shows remarkably enhanced absorption of visible light. • The MoO3–C3N4 composite shows superior visible-light photocatalytic activity. - Abstract: Composite photocatalyst of blue MoO3/g-C3N4 (denoted as MoO3–C3N4) was prepared by a simple mixing-calcination method. The obtained MoO3–C3N4 composite contains a low amount of molybdenum blue and shows remarkably enhanced absorption of visible light and high efficiency for the degradation of methylene blue dye (MB) under visible light. The enhancement of visible light photocatalytic activity in MoO3–C3N4 is attributed to the synergetic effect: (i) the strong and wide absorption of visible light, (ii) the high separation and easy transfer of photogenerated electron–hole pairs at the heterojunction interfaces derived from the match of band position between the g-C3N4 and MoO3

  7. Seagrass Restoration EnhancesBlue Carbon” Sequestration in Coastal Waters

    OpenAIRE

    Jill T Greiner; Karen J McGlathery; John Gunnell; McKee, Brent A.

    2013-01-01

    Seagrass meadows are highly productive habitats that provide important ecosystem services in the coastal zone, including carbon and nutrient sequestration. Organic carbon in seagrass sediment, known as “blue carbon,” accumulates from both in situ production and sedimentation of particulate carbon from the water column. Using a large-scale restoration (>1700 ha) in the Virginia coastal bays as a model system, we evaluated the role of seagrass, Zostera marina , restoration in carbon storage in ...

  8. Deteriorating haze situation and the severe haze episode during December 18-25 of 2013 in Xi'an, China, the worst event on record

    Science.gov (United States)

    Liu, Xiaodong; Hui, Ying; Yin, Zhi-Yong; Wang, Zhaosheng; Xie, Xiaoning; Fang, Jiangang

    2016-07-01

    Frequent occurrence of haze weather has been considered an urgent environmental problem in China and has attracted much attention worldwide in recent years. In this study, we examined the trend in the occurrence of haze days based on horizontal visibility in Xi'an, a major city in central China, since 2000. There were 49 haze days per year on average in Xi'an during 2000-2013, and the number of haze days has increased significantly since 2008, reaching 102 days in 2013. December is the month of the highest frequency of occurrence. During December 18-25 of 2013, the longest-lasting and most severe haze event in the recent decades occurred. The 8-day mean visibility in Xi'an was only 2.5 km with 5 days below 2 km. The mean air quality index in Xi'an during this period was 486.5, and in four of those days, it reached or exceeded the index's upper limit of 500. The exceptionally high level of PM2.5 concentration was inferred as the main reason of this severe haze episode. The local weather conditions were characterized by weak winds, enhanced atmospheric stability, and high relative humidity. Strong mid-tropospheric zonal flows in combination with weakened East Asian winter monsoon limited the cold air invasion from the higher latitudes, creating a condition of low pressure gradients in the lower troposphere and near the surface for a large region in central and eastern China. With high background emission levels, the suppressed dispersion of air pollutants eventually caused this severe haze episode affecting a large region in China.

  9. METEOROLOGICAL FACTORS IN THE FORMATION OF REGIONAL HAZE

    Science.gov (United States)

    The purpose of this research project was to determine the role of meteorological factors in the formation of widespread areas of haze in the eastern United States. Three case studies were made: A summer haze episode, an off-season haze episode and a non-haze episode.

  10. Analysis of the effects of blue light on morphofunctional status of in vitro cultured blastocysts from mice carrying gene of enhanced green fluorescent protein (EGFP).

    Science.gov (United States)

    Sakharova, N Yu; Mezhevikina, L M; Smirnov, A A; Vikhlyantseva, E F

    2014-05-01

    We studied the effect of blue light (440-490 nm) on the development of late blastocysts of mice carrying the gene of enhanced green fluorescent protein (EGFP). Exposure to blue light for 20 min reduced adhesive properties of blastocysts and their capacity to form primary colonies consisting of the cells of inner cell mass, trophoblast, and extraembryonic endoderm. The negative effects of blue light manifested in morphological changes in the primary colonies and impairment of differentiation and migration of cells of the trophoblast and extraembryonic endoderm. The problems of cell-cell interaction and inductive influences of the inner cell mass on other cell subpopulations are discussed. EGFP blastocysts were proposed as the model for evaluation of the mechanisms underlying the effects of blue light as the major negative factor of visible light used in in vitro experiments on mammalian embryos. PMID:24913583

  11. A broadband cavity-enhanced spectrometer for measuring the extinction of aerosols at blue and near-UV wavelengths

    Science.gov (United States)

    Venables, Dean; Fullam, Donovan; Hoa Le, Phuoc; Chen, Jun; Böge, Olaf; Herrmann, Hartmut

    2016-04-01

    We describe a new broadband cavity-enhanced absorption spectrometer for sensitive extinction measurements of aerosols. The instrument is distinguished by its broad and continuous spectral coverage from the near-UV to blue wavelengths (ca. 320 to 450 nm). The short wavelength region has been little explored compared to visible wavelengths, but is important because (1) brown carbon (BrC) absorbs strongly in this wavelength region, and (2) absorption of near-UV radiation in the atmosphere alters the photolysis rate of the key atmospheric species O3, NO2, and HONO, with implications for air quality and atmospheric oxidation capacity. The instrument performance and the effect of a switchable in-line filter are characterised. Early results using the instrument in the TROPOS atmospheric simulation chamber are presented. These experiments include studies of secondary organic aerosol formation (SOA), and biomass burning experiments of rice and wheat straw, followed by experiments simulating particle aging under daytime and nighttime conditions.

  12. Konjac glucomannan/graphene oxide hydrogel with enhanced dyes adsorption capability for methyl blue and methyl orange

    Science.gov (United States)

    Gan, Lu; Shang, Songmin; Hu, Enling; Yuen, Chun Wah Marcus; Jiang, Shou-xiang

    2015-12-01

    In the present study, the graphene oxide (GO) filled konjac glucomannan (KGM) hydrogel was prepared by using calcium oxide as the crosslinker. The structure of the prepared KGM/GO hydrogel was characterized. The prepared hydrogel was then used to adsorb methyl orange (MO) and methyl blue (MB) in aqueous solutions. Due to the presence of GO, KGM/GO hydrogel showed much enhanced adsorbing performance to both MO and MB compared to neat KGM hydrogel. The adsorption kinetics of the hydrogel was studied. The prepared hydrogel fitted for the pseudo-second-order kinetics model better. The adsorption isotherm of the MO and MB onto KGM/GO hydrogel was also studied and the results suggested that the both MO and MB adsorption behaviors fitted for the Freundlich isotherm model better. The prepared KGM/GO has application potentials to be as the adsorbent for water purifications.

  13. Enhanced photocatalytic degradation of methylene blue by ZnO-reduced graphene oxide composite synthesized via microwave-assisted reaction

    International Nuclear Information System (INIS)

    Highlights: → ZnO-reduced graphene oxide composite is synthesized via microwave assisted reaction. → The method allows a facile, safe and rapid reaction in aqueous media. → A high dye degradation efficiency is achieved under UV light irradiation. - Abstract: A quick and facile microwave-assisted reaction is used to synthesize ZnO-reduced graphene oxide (RGO) hybrid composites by reducing graphite oxide dispersion with zinc nitrate using a microwave synthesis system. Their photocatalytic performance in degradation of methylene blue is investigated and the results show that the RGO plays an important role in the enhancement of photocatalytic performance and the ZnO-RGO composite with 1.1 wt. % RGO achieves a maximum degradation efficiency of 88% in a neutral solution under UV light irradiation for 260 min as compared with pure ZnO (68%) due to the increased light absorption, the reduced charge recombination with the introduction of RGO.

  14. Enhancement of the binding affinity of methylene blue to site I in human serum albumin by cupric and ferric ions.

    Science.gov (United States)

    He, Ling-Ling; Wang, Yong-Xia; Wu, Xiao-Xia; Liu, Xian-Ping; Wang, Xin; Liu, Bin; Wang, Xin

    2015-12-01

    In this work, the binding characteristics of methylene blue (MB) to human serum albumin (HSA) and the influence of Cu(2+) and Fe(3+) on the binding affinity of MB to HSA were investigated using fluorescence, absorption, circular dichroism (CD) spectroscopy and molecular modelling. The results of competitive binding experiments using the site probes ketoprofen and ibuprofen as specific markers suggested that MB was located in site I within sub-domain IIA of HSA. The molecular modelling results agreed with the results of competitive site marker experiments and the results of CD spectra indicated that the interaction between MB and HSA caused the conformational changes in HSA. The binding affinity of MB to HSA was enhanced but to a different extent in the presence of Cu(2+) and Fe(3+), respectively, which indicated that the influence of different metal ions varied. Enhancement of the binding affinity of MB to HSA in the presence of Cu(2+) is due to the formation of Cu(2+)-HSA complex leading to the conformational changes in HSA, whereas in the presence of Fe(3+), enhancement of the binding affinity is due to the greater stability of the Fe(3+)-HSA-MB complex compared with the MB-HSA complex. PMID:25833007

  15. Fluorine doped tin oxide film with high haze and transmittance prepared for dye-sensitized solar cells

    Science.gov (United States)

    Otsuka, Rena; Endo, Takeshi; Takano, Takafumi; Takemura, Shuichiro; Murakami, Ryo; Muramoto, Ryosuke; Madarász, János; Okuya, Masayuki

    2015-08-01

    Fluorine doped tin oxide (FTO) transparent conductive oxide (TCO) film for dye-sensitized solar cell (DSSC) was investigated. Haze of the incident light through TCO film was easily tuned by controlling the surface morphology of FTO deposited on tin doped indium oxide (ITO) nano-particle seed layer pre-coated on a glass substrate, and the light harvest within the cell was effectively enhanced with high haze TCO film. The conversion efficiency of DSSC fabricated with TCO film with the haze of 30.1% reached as high as 7.7%, attributing to the consequence of the effective light harvest with the scattering within the cell.

  16. Postpartum Blues

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    Full Text Available ... blues The postpartum blues E-mail to a friend Please fill in all fields. Please enter a ... blues: Talk to your partner or a good friend about how you feel Get plenty of rest ...

  17. Functionalization of electrochemically deposited chitosan films with alginate and Prussian blue for enhanced performance of microbial fuel cells

    International Nuclear Information System (INIS)

    Highlights: • Preparation of biocompatible chitosan–alginate electrode. • The synergism between Acetobacter aceti and Gluconobacter roseus. • Better biofilm formation and enhanced electricity generation. • Immobilized Prussian blue system replaces the conventional ferricyanide system. - Abstract: This work is aimed at finding new strategies for the modification of anode and cathode that can lead to improved performance of microbial fuel cells (MFCs). The electrochemical deposition of chitosan onto carbon felt followed by further modification with alginate led to the formation of a biocompatible platform for the prolific growth of microorganisms on the anode (Chit–Alg/carbon felt anode). The novel modification strategy for the formation of Prussian blue film, on the electrochemically deposited chitosan layer, has helped in circumventing the disadvantages of using ferricyanide in the cathode compartment and also for improving the electron transfer characteristics of the film in phosphate buffer. The anode was tested for its efficacy with four different substrates viz., glucose, ethanol, acetate and grape juice in a two compartment MFC. The synergistic effect of the mixed culture of Acetobacter aceti and Gluconobacter roseus was utilized for current generation. The electrocatalytic activity of the biofilm and its morphology were characterized by cyclic voltammetry and scanning electron microscopy, respectively. The power densities were found to be 1.55 W/m3, 2.80 W/m3, 1.73 W/m3 and 3.87 W/m3 for glucose, ethanol, acetate and grape juice, respectively. The performance improved by 20.75% when compared to the bare electrode

  18. Metal-Organic Coordination Networks: Prussian Blue and Its Synergy with Pt Nanoparticles to Enhance Oxygen Reduction Kinetics.

    Science.gov (United States)

    Du, Lei; Du, Chunyu; Chen, Guangyu; Kong, Fanpeng; Yin, Geping; Wang, Yong

    2016-06-22

    Oxygen reduction reaction (ORR) is the cornerstone in the electrochemical energy conversion devices such as fuel cells and metal-air batteries. It remains a great challenge to develop the ORR electrocatalysts with fast kinetics and high durability. Herein, we report the synthesis of a novel metal-organic coordination networks material, prussian blue crystalline nanograins mosaicked within amorphous membrane (PB CNG-M-AM). Such unique PB CNG-M-AM is designed to enhance the electrocatalysis of Pt toward the ORR by the electrostatic self-assembly. Thus, obtained Pt-PB/C catalysts form numerous Pt-PB-gas three-phase boundaries and present rather high intrinsic activity, four-electron selectivity and superior stability. Moreover, a completely new synergetic mechanism between PB and Pt is discovered, which delicately alters the ORR route and significantly enhances the ORR kinetics. This work provides not only a new strategy and mechanism for developing highly efficient ORR electrocatalysts, but also an alternative way to utilize metal-organic coordination networks materials. PMID:27253719

  19. Facile preparation of a Pt/Prussian blue/graphene composite and its application as an enhanced catalyst for methanol oxidation

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Pt/Prussian blue/graphene catalyst was easily synthesized by the sequential electrodeposition method. • Prussian blue can promote the homogeneous growth of small Pt nanoparticles. • The as-made catalyst exhibited enhanced electro-catalytic performance for methanol oxidation. • The interplay of Prussian blue and Pt plays a significant role in reducing CO poisoning of the catalyst. - Abstract: Graphene nanosheets (GN) are modified by electrodeposition of Prussian blue (PB) followed by shape-regulated depositing of small Pt nanoparticles via the interaction between PB and PtCl62− to form a novel catalyst Pt/PB/GN. The Pt/PB/GN composite exhibits significantly enhanced electrocatalytic activity with a mass activity of 445 mA mg−1Pt (at 0.68 V vs. SCE) and high stability towards methanol oxidation. The high catalytic activity can be attributed to the unique porous architecture and peculiar electrical property of Prussian blue integrated with graphene layers which can not only well accommodate Pt nanoparticles but also provide multidimensional pathways to facilitate the mass and electron transport for methanol oxidation. This strategy can be readily extended to fabrication of other graphene-based hybrid supports for precious metal catalysts in fuel cell applications

  20. Different Techniques for Enhancing the Removal of Methylene Blue (MB)dye From Aqueous Solution

    International Nuclear Information System (INIS)

    Different techniques were conducted for removal of MB dye from aqueous solution. These techniques which were used separately are: (i) adsorption using activated carbon (AC) prepared from composite of different ratios of Date Pits-Clay (DP-C); (II) Chemical oxidation using H2O2; and (III) photo degradation using UV irradiation. In the adsorption technique, a series of experiments were undertaken in an agitated batch to assess the effect of the system variables; types of activated carbon, ph, adsorbent and adsorbate concentration, temperature and interfering ions. From the isotherm studies, the Langmuir monolayer capacity was 416.67 mg/g. The kinetic parameters have shown that they could be fitted well to the pseudo second- order kinetic and intra-particle diffusion models. The temperature study showed that the MB adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. The presence of interfering ions has an insignificant effect with the exception of Cl- anion that slightly decreases the adsorption of MB. Finally, the addition of H2O2 and UV irradiation in the presence AC enhances the removal of MB dye. The rates of the second order for the removal of MB dye take the following order: AC+H2O2+UV > AC+UV >AC+H2O2 > AC.

  1. Rapid formation and evolution of an extreme haze episode in Northern China during winter 2015

    Science.gov (United States)

    Sun, Yele; Chen, Chen; Zhang, Yingjie; Xu, Weiqi; Zhou, Libo; Cheng, Xueling; Zheng, Haitao; Ji, Dongsheng; Li, Jie; Tang, Xiao; Fu, Pingqing; Wang, Zifa

    2016-05-01

    We investigate the rapid formation and evolutionary mechanisms of an extremely severe and persistent haze episode that occurred in northern China during winter 2015 using comprehensive ground and vertical measurements, along with receptor and dispersion model analysis. Our results indicate that the life cycle of a severe winter haze episode typically consists of four stages: (1) rapid formation initiated by sudden changes in meteorological parameters and synchronous increases in most aerosol species, (2) persistent evolution with relatively constant variations in secondary inorganic aerosols and secondary organic aerosols, (3) further evolution associated with fog processing and significantly enhanced sulfate levels, and (4) clearing due to dry, cold north-northwesterly winds. Aerosol composition showed substantial changes during the formation and evolution of the haze episode but was generally dominated by regional secondary aerosols (53–67%). Our results demonstrate the important role of regional transport, largely from the southwest but also from the east, and of coal combustion emissions for winter haze formation in Beijing. Also, we observed an important downward mixing pathway during the severe haze in 2015 that can lead to rapid increases in certain aerosol species.

  2. Unlinking absorption and haze in thin film silicon solar cells front electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Boccard, Mathieu; Cuony, Peter; Battaglia, Corsin; Despeisse, Matthieu; Ballif, Christophe [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Rue A.-L. Breguet 2, 2000 Neuchatel (Switzerland)

    2010-11-15

    We study the respective influence of haze and free carrier absorption (FCA) of transparent front electrodes on the photogenerated current of micromorph thin film silicon solar cells. To decouple the haze and FCA we develop bi-layer front electrodes: a flat indium tin oxide layer assures conduction and allows us to tune FCA while the haze is adjusted by varying the thickness of a highly transparent rough ZnO layer. We show how a minimum amount of FCA leads only to a few percents absorption for a single light path but to a strong reduction of the cell current in the infrared part of the spectrum. Conversely, a current enhancement is shown with increasing front electrode haze up to a saturation of the current gain. This saturation correlates remarkably well with the haze of the front electrode calculated in silicon. This allows us to clarify the requirements for the front electrodes of micromorph cells. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Rare Earth Oxide-Treated Fullerene and Titania Composites with Enhanced Photocatalytic Activity for the Degradation of Methylene Blue

    Institute of Scientific and Technical Information of China (English)

    MENG Zada; ZHU Lei; CHOI Jong-geun; PARK Chong-yeon; OH Won-chun

    2011-01-01

    Rare earth oxide-treated fullerene and titania composites (Y-fullerene/TiO2) were prepared by the sol-gel method.The products had interesting surface compositions.X-ray diffraction patterns of the composites showed that the Y-fullerene/TiO2 composites contained a single and clear anatase phase.The surface properties were observed by scanning electron microscopy,which gave a characterization of the texture on the Y-fullerene/TiO2 composites and showed a homogenous distribution of titanium particles.The energy-dispersive X-ray spectra showed the presence of C and Ti with strong Y peaks.The composite obtained was also characterized with transmission electron microscopy and UV-Vis spectroscopy.The photocatalytic results showed that the y-fullerene/TiO2 composites had excellent activity for the degradation of methylene blue under visible light irradiation.This was attributed to both the effects on the photocatalysis of the supported TiO2 by charge transfer by the fullerene,and the introduction of yttrium to enhance photo-generated electron transfer.

  4. Enhanced photocatalytic activity of CeO2 using β-cyclodextrin on visible light assisted decoloration of methylene blue.

    Science.gov (United States)

    Pitchaimuthu, Sakthivel; Velusamy, Ponnusamy

    2014-01-01

    An attempt has been made to enhance the photocatalytic activity of CeO(2) for visible light assisted decoloration of methylene blue (MB) dye in aqueous solutions by β-cyclodextrin (β-CD). The inclusion complexation patterns between host and guest (i.e., β-CD and MB) have been confirmed with UV-visible spectral data. The interaction between CeO(2) and β-CD has also been characterized by field emission scanning electron microscopy analysis. The photocatalytic activity of the catalyst under visible light was investigated by measuring the photodegradation of MB in aqueous solution. The effects of key operational parameters such as initial dye concentration, initial pH, CeO(2) concentration as well as illumination time on the decolorization extents were investigated. Among the processing parameters, the pH of the reaction solution played an important role in tuning the photocatalytic activity of CeO(2). The maximum photodecoloration rate was achieved at basic pH (pH 11). Under the optimum operational conditions, approximately 99.6% dye removal was achieved within 120 min. The observed results indicate that the decolorization of the MB followed a pseudo-first order kinetics. PMID:24434976

  5. Enhanced Photocatalytic Degradation of Methylene Blue Using ZnFe2O4/MWCNT Composite Synthesized by Hydrothermal Method

    Directory of Open Access Journals (Sweden)

    Sonal Singhal

    2013-01-01

    Full Text Available Multiwalled carbon nanotubes (MWCNTs were synthesized using arc discharge method at a magnetic field of 430 G and purified using HNO3/H2O2. Transmission electron micrographs revealed that MWCNTs had inner and outer diameter of ~2 nm and ~4 nm, respectively. Raman spectroscopy confirmed formation of MWCNTs showing G-band at 1577 cm−1. ZnFe2O4 and ZnFe2O4/MWCNT were produced using one step hydrothermal method. Powder X-ray diffraction (XRD confirmed the formation of cubic spinel ZnFe2O4 as well as incorporation of MWCNT into ZnFe2O4. Visible light photocatalytic degradation of methylene blue (MB was studied using pure ZnFe2O4 and ZnFe2O4/MWCNT. The results showed that ZnFe2O4/MWCNT composite had higher photocatalytic activity as compared to pure ZnFe2O4. After irradiation for 5 hours in the visible light, MB was almost 84% degraded in the presence of ZnFe2O4 photocatalyst, while 99% degradation was observed in case of ZnFe2O4/MWCNT composite. This enhancement in the photocatalytic activity of composite may be attributed to the inhibition of recombination of photogenerated charge carriers.

  6. Enhanced methylene blue oxidative removal by copper electrode-based plasma irradiation with the addition of hydrogen peroxide.

    Science.gov (United States)

    Son, Guntae; Kim, Do-Hyung; Lee, Jung Seok; Lee, Hongshin

    2016-08-01

    Submerged plasma irradiation (SPI)-based advanced oxidation processes have been studied for the oxidation of recalcitrant organic compounds because of their various physical and chemical properties. However, SPI technologies still have a few drawbacks such as relatively low efficiency for wastewater treatment and high energy consumption. In order to overcome these drawbacks, in this study, we proposed the combination of SPI and the Cu(II)-catalyzed Fenton-like system. The removal of methylene blue (MB) by the SPI system was significantly enhanced upon the addition of H2O2. The pseudo-first-order rate constants of MB removal increased with the increase of applied voltage. In addition, the optimum H2O2 dose and initial solution pH were 100 mM and 9, respectively. The reactive oxidants responsible for MB removal in copper electrode-based SPI/H2O2 systems are likely to be hydroxyl radicals (OH) or cupryl ion (Cu(III)), wherein Cu(III) is especially important. Furthermore, the copper electrode-based SPI/H2O2 system is a novel advanced oxidation process capable of oxidizing water recalcitrant and toxic organic pollutants at neutral pH. PMID:27236847

  7. Heterogeneous chemistry: a mechanism missing in current models to explain secondary inorganic aerosol formation during the January 2013 haze episode in North China

    Directory of Open Access Journals (Sweden)

    B. Zheng

    2014-06-01

    Full Text Available Severe regional haze pollution events occurred in eastern and central China in January 2013, which had adverse effects on the environment and public health. Extremely high levels of particulate matter with aerodynamic diameter of 2.5 μm or less (PM2.5 with dominant components of sulfate and nitrate are responsible for the haze pollution. Although heterogeneous chemistry is thought to play an important role in the production of sulfate and nitrate during haze episodes, few studies have comprehensively evaluated the effect of heterogeneous chemistry on haze formation in China by using the 3-D models due to of a lack of treatments for heterogeneous reactions in most climate and chemical transport models. In this work, the offline-coupled WRF-CMAQ model with newly added heterogeneous reactions is applied to East Asia to evaluate the impacts of heterogeneous chemistry and the meteorological anomaly during January 2013 on regional haze formation. The revised CMAQ with heterogeneous chemistry not only captures the magnitude and temporal variation of sulfate and nitrate, but also reproduces the enhancement of relative contribution of sulfate and nitrate to PM2.5 mass from clean days to polluted haze days. These results indicate the significant role of heterogeneous chemistry in regional haze formation and improve the understanding of the haze formation mechanisms during the January 2013 episode.

  8. Haze detection by using modified normalized difference haze index in Beijing, Tianjin, and Hebei province

    Science.gov (United States)

    Han, Xinlei; Yao, Fengmei; Zhang, Jiahua; Waqar, Mirza Muhammad; Zha, Yong; He, Junliang

    2016-04-01

    This paper presents the development of index to detect haze from moderate resolution imaging spectroradiometer remote sensing data. Detection of haze over a large area has always been a problem. This study focuses on Beijing, Tianjin, and Shijiazhuang cities in China. These cities have suffered the worst hazy weather in recent years. The spectral influence of haze on surface features was determined through analysis of the spectral variations of surface covers between hazy and haze-free days. A spectral index known as modified normalized difference haze index (m-NDHI) is developed that can be used to monitor haze distribution and intensity. Correlation analysis of the derived m-NDHI and previously developed NDHI with in situ PM2.5 (particulate matter with diameter water bodies has a coefficient of 0.7096, 0.5864, and 0.4857 and NDHI has coefficient of 0.5625, 0.5321, and 0.4618 with PM2.5 for Beijing, Tianjin, and Shijiazhuang, respectively, in winter. Moreover, the correlation of m-NDHI with PM2.5 is 0.4097, 0.8092, and 0.5546 during the spring, summer, and autumn, respectively, in Beijing. This developed index can be a much easier and more effective method to detect haze in large scales from remotely sensing data and characterize the situation of urban atmospheric pollution.

  9. Hazing in Public Schools: A Liability Challenge for School Leaders

    Science.gov (United States)

    Essex, Nathan L.

    2014-01-01

    Hazing in public schools is a significant problem that may result in serious physical or emotional harm to students who are victims. According to experts in the field, each year more than 1,500,000 American students become new hazing victims. Hazing also results in legal challenges for school personnel. The courts consider public schools to be…

  10. CORNEAL HAZE FOLLOWING PHOTO REFRACT IVE KERATECTOMY

    Directory of Open Access Journals (Sweden)

    Atul

    2015-02-01

    Full Text Available To assess the incidence of corneal haze following surface ablation in (PRK in high myopic patients (≥6D. METHODS: In this prospective clinical study , 25 patients with high myopia (≥6D that is 50 eyes in total , underwent photorefractive keratectomy by Schwind Amaris 500E laser machine. At the initial presentation , each patient underwent a detailed clinical evaluation that included recording of medical history , detailed ocular history , Snellen visual acuity testing , and thorough anterior segment by slit - lamp bi o - microscopy and posterior segment examination with indirect ophthalmoscopy were done. Corneal topography and pachymetry were also done. The patient is followed up at 1week to observe for re - epithelialization and then at 1 , 3 and 6 months for observation o f haze under slit - lamp examinamination. RESULTS: In our study of 25 patients , that is 50 eyes in total were divided into 3 groups depending upon the spherical equivalence. Group 1 between 6.00 - 7.00D , group 2 between 7.00 - 8.00D , and in group 3 more than 8D (≥8.00D. Over 6months period of follow up a significant haze was noted as the patient’s refractive error increased. Out of 50 eyes , 11 eyes (84.6% with spherical equivalence of 6.00 - 7.00D (group 1 had grade 0 , 8 eyes (66.6% with spherical equivalence o f 7.00 - 8.00D (group 2 had grade 0 , and 6 eyes (24% with spherical equivalence ≥8.00D (group 3 had grade 0. Thus , the results show that there has been a significant decrease in the eyes with no corneal haze as the refractive error increased. Eyes with gr ade 1 haze in group1 were 2 (15.3% , group 2 were 3 (25% , and group 3 were 7 (28%. These results showed that the incidence of grade 1 haze increased with increase in spherical equivalence. Eyes with grade 2 haze in group 1 were 0 (0% , group 2 were 1 (8. 3% , group 3 were 10 (40%. Thus , it is seen that grade 2 haze was not noted in eyes with spherical equivalence between 6.00 - 7.00D , but were

  11. Postpartum Blues

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  12. Postpartum Blues

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    Full Text Available ... with this condition are happy most of the time. But compared to how she usually feels, the ... the "blues" usually lessens and goes away over time. What causes the baby blues? Medical experts believe ...

  13. Postpartum Blues

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  18. Postpartum Blues

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    Full Text Available ... of Obstetricians and Gynecologists recommends that women do these things to help relieve the baby blues: Talk ... of Obstetricians and Gynecologists recommends that women do these things to help relieve the baby blues: Talk ...

  19. Postpartum Blues

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    Full Text Available ... Medical experts believe that changes in the woman's hormones after delivery cause the postpartum blues. How can ... Medical experts believe that changes in the woman's hormones after delivery cause the postpartum blues. How can ...

  20. Postpartum Blues

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    Full Text Available ... can you manage the baby blues? The American College of Obstetricians and Gynecologists recommends that women do ... can you manage the baby blues? The American College of Obstetricians and Gynecologists recommends that women do ...

  1. Postpartum Blues

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    Full Text Available ... postpartum blues The postpartum blues E-mail to a friend Please fill in all fields. Please enter ... hear about breakthroughs for babies and families. Ask a question Our health experts can answer questions about ...

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  3. Visible-light-induced blue MoO{sub 3}–C{sub 3}N{sub 4} composite with enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yeping, E-mail: ypli@ujs.edu.cn [School of Pharmacy, Jiangsu University, Zhenjiang 212013 (China); Huang, Liying [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Xu, Jingbo [School of Pharmacy, Jiangsu University, Zhenjiang 212013 (China); Xu, Hui [Institute for Energy Research, Jiangsu University, Zhenjiang 212013 (China); Xu, Yuanguo; Xia, Jixiang [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Li, Huaming, E-mail: lihm@ujs.edu.cn [Institute for Energy Research, Jiangsu University, Zhenjiang 212013 (China)

    2015-10-15

    Highlights: • Novel MoO{sub 3}–C{sub 3}N{sub 4} composite was prepared by a mixing-calcination method. • The MoO{sub 3}–C{sub 3}N{sub 4} composite shows remarkably enhanced absorption of visible light. • The MoO{sub 3}–C{sub 3}N{sub 4} composite shows superior visible-light photocatalytic activity. - Abstract: Composite photocatalyst of blue MoO{sub 3}/g-C{sub 3}N{sub 4} (denoted as MoO{sub 3}–C{sub 3}N{sub 4}) was prepared by a simple mixing-calcination method. The obtained MoO{sub 3}–C{sub 3}N{sub 4} composite contains a low amount of molybdenum blue and shows remarkably enhanced absorption of visible light and high efficiency for the degradation of methylene blue dye (MB) under visible light. The enhancement of visible light photocatalytic activity in MoO{sub 3}–C{sub 3}N{sub 4} is attributed to the synergetic effect: (i) the strong and wide absorption of visible light, (ii) the high separation and easy transfer of photogenerated electron–hole pairs at the heterojunction interfaces derived from the match of band position between the g-C{sub 3}N{sub 4} and MoO{sub 3}.

  4. Source appointment of fine particle number and volume concentration during severe haze pollution in Beijing in January 2013.

    Science.gov (United States)

    Liu, Zirui; Wang, Yuesi; Hu, Bo; Ji, Dongsheng; Zhang, Junke; Wu, Fangkun; Wan, Xin; Wang, Yonghong

    2016-04-01

    Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, particle number size distribution (PNSD) and particle chemical composition (PCC) data collected in an intensive winter campaign in an urban site of Beijing were used to investigate the sources of ambient fine particles. Positive matrix factorization (PMF) analysis resolved a total of eight factors: two traffic factors, combustion factors, secondary aerosol, two accumulation mode aerosol factors, road dust, and long-range transported (LRT) dust. Traffic emissions (54 %) and combustion aerosol (27 %) were found to be the most important sources for particle number concentration, whereas combustion aerosol (33 %) and accumulation mode aerosol (37 %) dominated particle volume concentrations. Chemical compositions and sources of fine particles changed dynamically in the haze episodes. An enhanced role of secondary inorganic species was observed in the formation of haze pollution. Regional transport played an important role for high particles, contribution of which was on average up to 24-49 % during the haze episodes. Secondary aerosols from urban background presented the largest contributions (45 %) for the rapid increase of fine particles in the severest haze episode. In addition, the invasion of LRT dust aerosols further elevated the fine particles during the extreme haze episode. Our results showed a clear impact of regional transport on the local air pollution, suggesting the importance of regional-scale emission control measures in the local air quality management of Beijing. PMID:26667647

  5. Analysis of a winter regional haze event and its formation mechanism in the North China Plain

    Directory of Open Access Journals (Sweden)

    X. J. Zhao

    2013-01-01

    these source regions. The accumulation of pollutants was one main factor in the haze formation. The enhanced southwest wind in the last period of this episode transported pollutants to the downwind area and expanded the regional scope of the haze.

  6. Absence of red-light enhancement of phototropism in pea seedlings at limiting irradiances of blue light

    International Nuclear Information System (INIS)

    The kinetics of phototropism were determined from infrared video recordings of third internodes of intact 7 d etiolated pea seedlings (Pisum sativum L. cv Alcan) exposed to continuous, unilateral blue light (460 nm). Small but significant curvatures (ca. 1–2°) were observed after a 2 h stimulation at 0.8 pmol m-2 s-1. Both latency (i.e., lag time) and rate of curvature were dependent on irradiance between 0.8 and 80 pmol m-2 s-1. Maximum rates of curvature at the highest irradiance of blue light were 74% greater in seedlings that received 2 min red light (270 J m-2) 20 h earlier, but latency was unaffected. An irradiance-response curve for curvature at 2 h was obtained with unilateral, broad-spectrum blue light between 4 and 90,000 pmol m-2 s-1. Maximum tropistic response in dark-grown seedlings (ca. 25°) occurred between 30 and 1000 pmol m-2 s-1. Peak response for red light-treated seedlings (ca. 55°) was obtained at 1000 pmol m-2 s-1. Above this irradiance, phototropism declined by 12–15° for both red-treated and dark-grown plants. Red light did not significantly stimulate phototropism at lower, limiting irradiances of blue light. The data do not support the hypothesis that phytochrome affects the amount or activity of a photoreceptor for phototropism

  7. Blue-shifted emission and enhanced quantum efficiency viaπ-bridge elongation in carbazole-carborane dyads.

    Science.gov (United States)

    Wang, Zhaojin; Jiang, Peng; Wang, Tianyu; Moxey, Graeme J; Cifuentes, Marie P; Zhang, Chi; Humphrey, Mark G

    2016-06-21

    Carbazole-carborane linear dyads and di(carbazole)-carborane V-shaped dyads with phenyleneethynylene-based bridges have been synthesized. The V-shaped dyads display the expected red-shifts in the location of their UV-Vis absorption maxima on bridge-lengthening, but show unusual blue-shifts in charge-transfer (CT) emission on the same π-system lengthening. These blue-shifts can be attributed to the 2n + 3 electron count within the carborane cluster in the excited state. The linear dyads luminesce via a combination of local excited (LE) and CT emission, with a red-shift in LE emission and a blue-shift in CT emission accompanying π-bridge elongation. A quantum efficiency as high as 86% in the solution state is achieved from the hybrid LE/CT emission. Time-dependent density functional theory (TD-DFT) calculations at the excited state of these compounds have clarified the photoluminescence blue-shift and suggested a typical cluster C-C bond elongation in the V-shaped dyads. Calculations on the elongated linear dyads have suggested that the electron density is localized at the phenyleneethynylene-containing bridge. PMID:27225829

  8. Size-resolved aerosol chemical analysis of extreme haze pollution events during early 2013 in urban Beijing, China

    International Nuclear Information System (INIS)

    Highlights: • Anthropogenic species substantially accumulated in both fine and coarse particles. • Secondary organic carbon in PM1.1 decreased from clear to haze days. • The mass peak shifted to larger particles from clear to haze days. • The NO3−/SO42− ratio decreased with enhanced haze pollution. • Both mobile local and stationary regional sources were vital for haze formation. - Abstract: Using size-resolved filter sampling and chemical characterization, high concentrations of water-soluble ions, carbonaceous species and heavy metals were found in both fine (PM2.1) and coarse (PM2.1–9) particles in Beijing during haze events in early 2013. Even on clear days, average mass concentration of submicron particles (PM1.1) was several times higher than that previously measured in most of abroad urban areas. A high concentration of particulate matter on haze days weakens the incident solar radiation, which reduces the generation rate of secondary organic carbon in PM1.1. We show that the peak mass concentration of particles shifted from 0.43–0.65 μm on clear days to 0.65–1.1 μm on lightly polluted days and to 1.1–2.1 μm on heavily polluted days. The peak shifts were also found for the following species: organic carbon, elemental carbon, NH4+, SO42−, NO3−, K, Cu, Zn, Cd and Pb. Our findings demonstrate that secondary inorganic aerosols (36%) and organic matter (26%) dominated the fine particle mass on heavily polluted days, while their contribution reduced to 29% and 18%, respectively, on clear days. Besides fine particles, anthropogenic chemical species also substantially accumulated in the coarse mode, which suggests that particles with aerodynamic diameter larger than 2.1 μm cannot be neglected during severe haze events

  9. Pollutional haze as a potential cause of lung cancer

    Science.gov (United States)

    Shi, Xuefei; Liu, Hongbing

    2015-01-01

    Along with fast economic growth over the past few decades, the world is faced with cumulatively serious environmental pollution and now is paying increased attention to pollutional haze. In the last few years, multiple epidemiological studies and animal models have provided compelling evidences that inhalation of pollutional haze could be linked to several adverse health effects. Since the respiratory tract is the crucial passageway of entry of pollutional haze, the lung is the main affected organ. Therefore, here, we reviewed some of the important information around long-term exposure to pollutional haze and lung cancer, as well as highlight important roles of pollutional haze in human lung carcinogenesis, providing evidence for pollutional haze acting as another risk factor for lung cancer. PMID:26623118

  10. CORNEAL HAZE FOLLOWING PHOTO REFRACT IVE KERATECTOMY

    OpenAIRE

    Atul; Superna; Pervaiz

    2015-01-01

    To assess the incidence of corneal haze following surface ablation in (PRK) in high myopic patients (≥6D). METHODS: In this prospective clinical study , 25 patients with high myopia (≥6D) that is 50 eyes in total , underwent photorefractive keratectomy by Schwind Amaris 500E laser machine. At the initial presentation , each patient underwent a detailed clinical evaluation that included recording of medical history , detailed ocular history , ...

  11. Photon-avalanche upconversion of Ho3+ in NaYF4 and enhancement of violet, blue and green emissions induced by sensitization of Tm3+

    International Nuclear Information System (INIS)

    Ho3+ singly doped and Ho3+/Tm3+ co-doped hexagonal NaYF4 powders have been synthesized by a solid-state reaction method. Under excitation of 671 nm diode laser, upconverted blue, green and red emission bands are observed in Ho3+ singly doped sample. Temporal evolution and excitation power dependent behavior for the green emission are explored, indicating that a photon-avalanche mechanism is responsible for the upconversion processes in Ho3+ singly doped hexagonal NaYF4 sample. With the introduction of Tm3+, the intensities of both blue and green emissions of Ho3+ are efficiently enhanced, which are attributed to two energy transfer processes from Tm3+ to Ho3+, i.e., 3F4 (Tm3+) + 5I8(Ho3+) → 3H6 (Tm3+) + 5I7(Ho3+) and 1G4 (Tm3+) + 5I8(Ho3+) → 3H6 (Tm3+) + 5F3(Ho3+). The result offers a new sensitization approach to enhance the upconversion efficiency of Ho3+ under 671 nm excitation.

  12. Postpartum Blues

    Medline Plus

    Full Text Available ... leader Partner Spotlight Become a partner World Prematurity Day Your support helps babies We are determined to ... confused The postpartum blues peak three to five days after delivery. They usually end by the tenth ...

  13. Postpartum Blues

    Medline Plus

    Full Text Available ... Saving Just a moment, please. You've saved this page It's been added to your dashboard . After ... blues" is not really correct since women with this condition are happy most of the time. But ...

  14. Postpartum Blues

    Medline Plus

    Full Text Available ... dashboard . After the baby is born, many new mothers have the postpartum blues (also called the baby ... compared to how she usually feels, the new mother: Is more irritable Cries more easily Feels sad ...

  15. Postpartum Blues

    Medline Plus

    Full Text Available ... articles March of Dimes Premature Birth Report Card Grades Cities, Counties; Focuses on Racial and Ethnic Disparities ... baby blues: Talk to your partner or a good friend about how you feel Get plenty of ...

  16. Postpartum Blues

    Medline Plus

    Full Text Available ... leader Partner Spotlight Become a partner World Prematurity Day World Prematurity Your support helps babies We are ... confused The postpartum blues peak three to five days after delivery. They usually end by the tenth ...

  17. Postpartum Blues

    Medline Plus

    Full Text Available ... for your baby Feeding your baby Common illnesses New parents Family health & safety Complications & Loss Pregnancy complications ... your dashboard . After the baby is born, many new mothers have the postpartum blues (also called the ...

  18. Probing the severe haze pollution in three typical regions of China: Characteristics, sources and regional impacts

    Science.gov (United States)

    Wang, Qiongzhen; Zhuang, Guoshun; Huang, Kan; Liu, Tingna; Deng, Congrui; Xu, Jian; Lin, Yanfen; Guo, Zhigang; Chen, Ying; Fu, Qingyan; Fu, Joshua S.; Chen, Jiakuan

    2015-11-01

    PM2.5 with its major chemical components were measured and analyzed during a concurrent haze in Jan. 1-19, 2013 at three sites (Shanghai, Beijing, and Huaniao, a remote isle over the East China Sea) to probe the sources and formation process of such a severe haze over three typical regions in China. The mean PM2.5 concentrations during the severely polluted days reached 180.8 μg m-3, 299.2 μg m-3, and 131.1 μg m-3 in Shanghai, Beijing, and the Huaniao Isle, respectively. The mass ratio of the sum of SO42- , NO3-, and NH4+ to PM2.5 were over 1/3 during the polluted days at all the three sites. Promoted gas-to-particle transformations from acidic SO2 and NOx to SO42- and NO3- under high relative humidity conditions played a major role in the formation of this severe haze. Significant contribution of traffic emissions to the haze formation over China was suggested to be one of the major sources in triggering the heavy haze over China. Specifically, there was a more contribution from traffic in Shanghai than in Beijing as indicated by the higher NO3-/SO42- ratio in Shanghai. In Beijing, the enhanced coal combustion for winter heating along with the traffic emission was suggested to be the major two sources of this haze episode. Typical pollution elements such as As, Cd, and Pb as well as Cl- and K+ were substantially enhanced in the severely polluted days. Although the Huaniao Isle is located in the remote oceanic area as a background site, pollution elements, secondary ions, and K+ all increased substantially during the polluted days. As visualized by the backward air mass trajectories associated with the potential source region identification technique, air masses that passed over Northern China and Yangtze River Delta evidently invaded the offshore areas of Eastern China. The ratios of As, Cd, Cu, Zn, and K+ to Al at the Huaniao Isle were closer to those of Beijing rather than Shanghai, indicating that the marine aerosol over the East China Sea had been

  19. Climate modulation of the Tibetan Plateau on haze in China

    Science.gov (United States)

    Xu, X.; Zhao, T.; Liu, F.; Gong, S. L.; Kristovich, D.; Lu, C.; Guo, Y.; Cheng, X.; Wang, Y.; Ding, G.

    2016-02-01

    Rapid increases in pollutant emissions in conjunction with stagnant meteorological conditions result in haze pollution in China. Recent frequent haze in China has attracted worldwide attention. Here we show a relationship between the haze events and Tibetan Plateau (TP)'s environment and climate changes. Based on observational data taken over recent decades, we identify central-eastern China (CEC) as a climatological large-scale "susceptible region" of frequent haze, which is harbored by the TP with its impact on midlatitude westerly winds. The observational and modeling studies demonstrate that the interannual variations in the thermal forcing of TP are positively correlated with the incidences of wintertime haze over CEC. Further analysis indicates that the climate warming of the TP induced changes in atmospheric circulation, driving frequent haze events in CEC. The frequent haze occurrences in CEC are consistent with decreasing winter monsoon winds, intensifying downward air flows and increasing atmospheric stability in the lower troposphere over the CEC in association with upstream plateau's thermal anomalies. Therefore, variations of haze in China are related to mechanical and thermal forcing by the TP. Our results also suggest that implications of the large TP topography for environment and climate changes should be taken into account for air pollution mitigation policies in China.

  20. Chinese haze versus Western smog: lessons learned

    OpenAIRE

    Zhang, Junfeng; Jonathan M. Samet

    2015-01-01

    Air pollution in many Chinese cities has been so severe in recent years that a special terminology, the “Chinese haze”, was created to describe China’s air quality problem. Historically, the problem of Chinese haze has developed several decades after Western high-income countries have significantly improved their air quality from the smog-laden days in the early- and mid-20th century. Hence it is important to provide a global and historical perspective to help China combat the current air pol...

  1. Does Pluto Have a Haze Layer?

    Science.gov (United States)

    Elliot, James L.

    1997-01-01

    The goal of this research was to determine whether Pluto has a haze layer through observations (with the Kuiper Airborne Observatory) of a stellar occultation by Pluto that was originally predicted to occur on 1993 October 3. As described in the attached material, our extensive astrometric measurements determined that this occultation would not be visible from Earth, and we canceled plans to observe it with the KAO. Efforts were then directed toward improving our astrometric techniques so that we could find future occultations with which we could satisfy the original goals of the research proposed for this grant.

  2. Formation process of the widespread extreme haze pollution over northern China in January 2013: Implications for regional air quality and climate

    Science.gov (United States)

    Tao, Minghui; Chen, Liangfu; Xiong, Xiaozhen; Zhang, Meigen; Ma, Pengfei; Tao, Jinhua; Wang, Zifeng

    2014-12-01

    In this study, we present a regional insight into characteristics and formation process of the widespread extreme haze pollution in northern China during January of 2013 using integrated satellite observations and ground measurements. Different from common regional pollution, dense haze clouds during the most polluted period not only wandered over northern China for more than one week, but also exhibited large spatial variations with some abrupt peak values in Beijing. High UV Aerosol Index (UVAI) values >2.5 indicate prevalent absorbing aerosols in upper part of the haze clouds. CALIPSO vertical detection shows that the haze layers were more than 3 km thick, with strong extinction within 1 km near surface and elevated dust layers above. Top of the more than 2 km thick dust plumes can reach 5 km, having a substantial contribution to the haze clouds. Movement of high aerosol loading regions with aerosol optical depth (AOD) exceeding 2.0 shows a notable superposition of different pollution processes within boundary layer, which largely enhanced the haze pollution. Peak value of PM10 in industrial cities of Hebei was around 1000 μg/m3, almost twice of that in usual pollution. Subsequent peak values of PM10 from south to north confirm the intense regional transport, which could be the main cause of sudden record-breaking particle concentration in Beijing. Anomalous weather conditions facilitated the unusual heavy pollution became extremely severe. Our results indicate close connections between variation of atmospheric circulation and the regional heavy pollution over northern China.

  3. 76 FR 36450 - Approval and Promulgation of Air Quality Implementation Plans; State of Nevada; Regional Haze...

    Science.gov (United States)

    2011-06-22

    ... promulgated a rule to address regional haze on July 1, 1999 known as the Regional Haze Rule (RHR) (64 FR 35713... Submittals II. Background A. Description of Regional Haze B. History of Regional Haze Regulations C. Roles of... conditions. 64 FR 35715 (July 1, 1999). \\1\\ Visual range is the greatest distance, in kilometers or miles,...

  4. 77 FR 38185 - Approval and Promulgation of Implementation Plans; State of North Carolina; Regional Haze State...

    Science.gov (United States)

    2012-06-27

    ... regional haze issues. EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713), the..., 2007, SIP revision to address the first implementation period for regional haze.\\1\\ See 77 FR 11858...' test.'' See also 70 FR 39121. North Carolina's analysis in the regional haze SIP revision...

  5. 77 FR 38191 - Approval and Promulgation of Implementation Plans; State of Mississippi; Regional Haze State...

    Science.gov (United States)

    2012-06-27

    ... regional haze issues. EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713), the... address the first implementation period for regional haze.\\1\\ See 77 FR 11879. EPA proposed a limited... FR 33642), EPA finalized a limited disapproval of the Mississippi regional haze SIP because...

  6. 77 FR 38509 - Approval and Promulgation of Implementation Plans; South Carolina; Regional Haze State...

    Science.gov (United States)

    2012-06-28

    ... promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional Haze Rule (RHR). The... address the first implementation period for regional haze.\\1\\ See 77 FR 11894. EPA proposed a limited..., 2012, proposal action on the South Carolina regional haze SIP submittal (77 FR 11906), the states...

  7. 77 FR 38501 - Approval and Promulgation of Implementation Plans; State of Georgia; Regional Haze State...

    Science.gov (United States)

    2012-06-28

    ... haze on July 1, 1999 ] (64 FR 35714), the Regional Haze Rule (RHR). The RHR revised the existing... period for regional haze.\\1\\ See 77 FR 11452. EPA proposed a limited approval of Georgia's SIP revisions... discussed in the proposed rulemaking (77 FR 11474-11475), Georgia's regional haze SIP satisfies the...

  8. 78 FR 53250 - Approval and Promulgation of Air Quality Implementation Plans; State of Florida; Regional Haze...

    Science.gov (United States)

    2013-08-29

    ... regional haze issues. EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713... first implementation period for regional haze.\\1\\ See 77 FR 31240. EPA's May 25, 2012, proposed... Florida regional haze SIP, and on June 7, 2012 (77 FR 33642), EPA finalized a limited disapproval of...

  9. 77 FR 38515 - Approval and Promulgation of Implementation Plans; State of Alabama; Regional Haze State...

    Science.gov (United States)

    2012-06-28

    ... haze on July 1, 1999 (64 FR 35713), the Regional Haze Rule (RHR). The RHR revised the existing... also 70 FR 39121. Alabama's analysis in the regional haze SIP revision was consistent with EPA's... February 28, 2012, proposal action on the Alabama regional haze SIP submittal (77 FR 11949), the RHR...

  10. Enhancement of power conversion efficiency of dye-sensitized solar cells by co-sensitization of Phloxine B and Bromophenol blue dyes on ZnO photoanode

    International Nuclear Information System (INIS)

    A single dye usually absorbs light only in a limited range of solar spectrum. In order to widen the absorption range, a combination of dyes, namely, Phloxine B and Bromophenol blue have been used as sensitizers in ZnO based dye sensitized solar cell (DSSC). It has been found that the DSSC sensitized by mixed dyes exhibited better photovoltaic performance than those observed with the DSSCs using test dyes individually. It has been ascribed to the enhanced absorption of light particularly in higher energy region (λ=400–550 nm) when both dyes were used together as was evident from the absorption spectra of dyes adsorbed onto ZnO electrode. The DSSC using ZnO electrode sensitized by mixed dyes provided JSC=5.6 mA cm−2, VOC=0.606 V, FF=0.53 and maximum energy conversion efficiency (η) of 1.35% on illuminating the cell with visible light of 150 mW cm−2 intensity. - Highlights: • Phloxine B and Bromophenol blue have been used as sensitizers in ZnO based DSSC. • DSSC sensitized by mixed dyes exhibited better photovoltaic performance than those observed with the DSSCs using test dyes individually. • Enhanced absorption of light particularly in higher energy region (λ=400–550 nm) have been observed when both dyes were used together. • The DSSC using ZnO electrode sensitized by mixed dyes provided Jsc=5.6 mA cm−2, Voc=0.606 V, FF=0.53. • Efficiency of 1.35% is achieved at visible light intensity of 150 mW cm−2

  11. Enhanced visible-light-response photocatalytic degradation of methylene blue on Fe-loaded BiVO4 photocatalyst

    International Nuclear Information System (INIS)

    Highlights: • Fe-loaded BiVO4 particles were prepared by hydrothermal method. • Physicochemical properties played a significant role in photocatalytic process. • All Fe-loaded BiVO4 samples showed higher photocatalytic activity than pure BiVO4. • The Fe3+ ions may improve the separation of photogenerated electrons and holes. - Abstract: Pure BiVO4 and nominal 0.5–5.0 mol% Fe-loaded BiVO4 samples were synthesized by hydrothermal method. All samples were characterized in order to obtain the correlation between structure and photocatalytic properties by X-ray diffraction, Brunauer, Emmett and Teller, UV–vis diffuse reflectance spectrophotometry, photoluminescence spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and inductively coupled plasma-optical emission spectroscopy. The structure of all samples was single-phase monoclinic scheelite. The absorption spectrum of 5.0 mol% Fe-loaded BiVO4 shifted to the visible region, suggesting the potential application of this material as a superior visible-light driven photocatalyst in comparison with pure BiVO4. Photocatalytic activities of all photocatalyst samples were examined by studying the degradation of methylene blue under visible light irradiation. The results clearly showed that Fe-loaded BiVO4 sample exhibited remarkably higher activity than pure BiVO4

  12. A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

    International Nuclear Information System (INIS)

    In this investigation, a facile modification of g-C3N4 through co-pyrolysis of melamine and sodium nitrate or potassium nitrate was reported and the as-synthesized samples were characterized by a collection of techniques, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV–vis diffuse reflectance spectroscopy, nitrogen adsorption–desorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and elemental analysis. Based upon the analysis, we speculated that the g-C3N4 framework was partially destroyed to produce cyano-containing fragments, which resulted into the variation of physical and optical properties, further affecting the adsorption and photocatalytic performance of g-C3N4 on the dye methylene blue. Furthermore, we found that nitrate anions rather than sodium or potassium ions had important effect on the structure and photocatalytic performance of g-C3N4. In addition, the photocatalysis mechanism and reusability test were also investigated and discussed in the study.

  13. Enhanced visible-light-response photocatalytic degradation of methylene blue on Fe-loaded BiVO{sub 4} photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Chala, Sinaporn [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wetchakun, Khatcharin [Program of Physics, Faculty of Science, Ubon Ratchathani Rajabhat University, Ubon Ratchathani 34000 (Thailand); Phanichphant, Sukon [Materials Science Research Centre, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Inceesungvorn, Burapat [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wetchakun, Natda, E-mail: natda_we@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-06-01

    Highlights: • Fe-loaded BiVO{sub 4} particles were prepared by hydrothermal method. • Physicochemical properties played a significant role in photocatalytic process. • All Fe-loaded BiVO{sub 4} samples showed higher photocatalytic activity than pure BiVO{sub 4}. • The Fe{sup 3+} ions may improve the separation of photogenerated electrons and holes. - Abstract: Pure BiVO{sub 4} and nominal 0.5–5.0 mol% Fe-loaded BiVO{sub 4} samples were synthesized by hydrothermal method. All samples were characterized in order to obtain the correlation between structure and photocatalytic properties by X-ray diffraction, Brunauer, Emmett and Teller, UV–vis diffuse reflectance spectrophotometry, photoluminescence spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and inductively coupled plasma-optical emission spectroscopy. The structure of all samples was single-phase monoclinic scheelite. The absorption spectrum of 5.0 mol% Fe-loaded BiVO{sub 4} shifted to the visible region, suggesting the potential application of this material as a superior visible-light driven photocatalyst in comparison with pure BiVO{sub 4}. Photocatalytic activities of all photocatalyst samples were examined by studying the degradation of methylene blue under visible light irradiation. The results clearly showed that Fe-loaded BiVO{sub 4} sample exhibited remarkably higher activity than pure BiVO{sub 4}.

  14. Blue gods, blue oil, and blue people.

    Science.gov (United States)

    Fairbanks, V F

    1994-09-01

    Studies of the composition of coal tar, which began in Prussia in 1834, profoundly affected the economies of Germany, Great Britain, India, and the rest of the world, as well as medicine and surgery. Such effects include the collapse of the profits of the British indigo monopoly, the growth in economic power of Germany based on coal tar chemistry, and an economic crisis in India that led to more humane tax laws and, ultimately, the independence of India and the end of the British Empire. Additional consequences were the development of antiseptic surgery and the synthesis of a wide variety of useful drugs that have eradicated infections and alleviated pain. Many of these drugs, particularly the commonly used analgesics, sulfonamides, sulfones, and local anesthetics, are derivatives of aniline, originally called "blue oil" or "kyanol." Some of these aniline derivatives, however, have also caused aplastic anemia, agranulocytosis, and methemoglobinemia (that is, "blue people"). Exposure to aniline drugs, particularly when two or three aniline drugs are taken concurrently, seems to be the commonest cause of methemoglobinemia today. PMID:8065194

  15. An integrated campaign for investigation of winter-time continental haze over Indo-Gangetic Basin and its radiative effects

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sanat Kumar, E-mail: sanatkrdas@gmail.com [Environmental Sciences Section, Bose Institute, Kolkata (India); Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); Chatterjee, Abhijit [Environmental Sciences Section, Bose Institute, Kolkata (India); Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); National Facility on Astroparticle Physics and Space Science, Darjeeling (India); Ghosh, Sanjay K. [Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); National Facility on Astroparticle Physics and Space Science, Darjeeling (India); Raha, Sibaji [Environmental Sciences Section, Bose Institute, Kolkata (India); Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); National Facility on Astroparticle Physics and Space Science, Darjeeling (India)

    2015-11-15

    An outflow of continental haze occurs from Indo-Gangetic Basin (IGB) in the North to Bay of Bengal (BoB) in the South. An integrated campaign was organized to investigate this continental haze during December 2013–February 2014 at source and remote regions within IGB to quantify its radiative effects. Measurements were carried out at three locations in eastern India; 1) Kalas Island, Sundarban (21.68°N, 88.57°E) — an isolated island along the north-east coast of BoB, 2) Kolkata (22.57°N, 88.42°E) — an urban metropolis and 3) Siliguri (26.70°N, 88.35°E) — an urban region at the foothills of eastern Himalayas. Ground-based AOD (at 0.5 μm) is observed to be maximum (1.25 ± 0.18) over Kolkata followed by Siliguri (0.60 ± 0.17) and minimum over Sundarban (0.53 ± 0.18). Black carbon concentration is found to be maximum at Kolkata (21.6 ± 6.6 μg·m{sup −3}) with almost equal concentrations at Siliguri (12.6 ± 5.2 μg·m{sup −3}) and Sundarban (12.3 ± 3.0 μg·m{sup −3}). Combination of MODIS-AOD and back-trajectories analysis shows an outflow of winter-time continental haze originating from central IGB and venting out through Sundarban towards BoB. This continental haze with high extinction coefficient is identified up to central BoB using CALIPSO observations and is found to contribute ~ 75% to marine AOD over central BoB. This haze produces significantly high aerosol radiative forcing within the atmosphere over Kolkata (75.4 Wm{sup −2}) as well as over Siliguri and Sundarban (40 Wm{sup −2}) indicating large forcing over entire IGB, from foothills of the Himalayas to coastal region. This winter-time continental haze also causes about similar radiative heating (1.5 K·day{sup −1}) from Siliguri to Sundarban which is enhanced over Kolkata (3 K·day{sup −1}) due to large emission of local urban aerosols. This high aerosol heating over entire IGB and coastal region of BoB can have considerable impact on the monsoonal circulation and more

  16. An integrated campaign for investigation of winter-time continental haze over Indo-Gangetic Basin and its radiative effects

    International Nuclear Information System (INIS)

    An outflow of continental haze occurs from Indo-Gangetic Basin (IGB) in the North to Bay of Bengal (BoB) in the South. An integrated campaign was organized to investigate this continental haze during December 2013–February 2014 at source and remote regions within IGB to quantify its radiative effects. Measurements were carried out at three locations in eastern India; 1) Kalas Island, Sundarban (21.68°N, 88.57°E) — an isolated island along the north-east coast of BoB, 2) Kolkata (22.57°N, 88.42°E) — an urban metropolis and 3) Siliguri (26.70°N, 88.35°E) — an urban region at the foothills of eastern Himalayas. Ground-based AOD (at 0.5 μm) is observed to be maximum (1.25 ± 0.18) over Kolkata followed by Siliguri (0.60 ± 0.17) and minimum over Sundarban (0.53 ± 0.18). Black carbon concentration is found to be maximum at Kolkata (21.6 ± 6.6 μg·m−3) with almost equal concentrations at Siliguri (12.6 ± 5.2 μg·m−3) and Sundarban (12.3 ± 3.0 μg·m−3). Combination of MODIS-AOD and back-trajectories analysis shows an outflow of winter-time continental haze originating from central IGB and venting out through Sundarban towards BoB. This continental haze with high extinction coefficient is identified up to central BoB using CALIPSO observations and is found to contribute ~ 75% to marine AOD over central BoB. This haze produces significantly high aerosol radiative forcing within the atmosphere over Kolkata (75.4 Wm−2) as well as over Siliguri and Sundarban (40 Wm−2) indicating large forcing over entire IGB, from foothills of the Himalayas to coastal region. This winter-time continental haze also causes about similar radiative heating (1.5 K·day−1) from Siliguri to Sundarban which is enhanced over Kolkata (3 K·day−1) due to large emission of local urban aerosols. This high aerosol heating over entire IGB and coastal region of BoB can have considerable impact on the monsoonal circulation and more importantly, such haze transported over to

  17. Upper limits of possible photochemical hazes on Pluto

    International Nuclear Information System (INIS)

    Elliot et al. [1989] invoked a haze layer near the surface of Pluto to explain certain features of a stellar occultation by that planet in June, 1988. The primary requirements for this haze layer were that it achieve unity tangential optical depth at a radius of 1174 km and be essentially transparent above 1189 km. The authors explore here the possibility that aerosols generated through methane photolysis could be responsible for such a haze layer. A comprehensive model of aerosol production, particle growth, sedimentation and condensation is applied to the atmosphere of Pluto using pressures, temperatures and composition derived from the stellar occultation and other data. They test two atmosphere models proposed in the literature, one from Elliot et al. [1989], and one from Hubbard et al. [1989], as well as a range of optical properties for the particles. In order to produce a haze with unity tangential optical depth at 1174 km, they had to use an aerosol mass production rate equal to twice the total methane dissociation rate due to solar UV expected for Pluto and assume that the particles produced were 10 times more absorbing than those in other hazes in the outer solar system. The possibility of condensation in the atmosphere was considered but did not result in distinctly different haze optical depths. If a photochemical haze on Pluto was responsible for the occultation lightcurve measured by Elliot et al., operation of a photochemical system different from those on Titan, Uranus or Neptune is indicated

  18. Slicing The 2010 Saturn's Storm: Upper Clouds And Hazes

    Science.gov (United States)

    Perez-Hoyos, Santiago; Sanz-Requena, J. F.; Sanchez-Lavega, A.; Hueso, R.

    2012-10-01

    At the end of 2010 a small storm erupted in Saturn's northern mid-latitudes. Starting from a localized perturbation, it grew up to be a global-scale disturbance and cover the whole latitude band by February, 2011 (Fletcher et al. 2011, Science 332; Sánchez-Lavega et al. 2011, Nature 475; Fischer et al. 2011, Nature 475). By June, 2011 the storm was facing its end and gradually disappeared (Sánchez-Lavega et al. 2012, Icarus 220). In this work we use the observations acquired by the Cassini ISS instrument during the whole process to investigate the vertical cloud and haze structure above the ammonia condensation level (roughly 1 bar). Cassini ISS observations cover visual wavelengths from the blue to the near-infrared including two methane absorption bands. Such observations have been modeled using a radiative transfer code which reproduces the atmospheric reflectivity as a function of observation/illumination geometry and wavelength together with a retrieval technique to find maximum likelihood atmospheric models. This allows to investigate some atmospheric parameters: cloud-top pressures, aerosol optical thickness and particle absorption, among others. We will focus on two aspects: (1) maximum likelihood models for the undisturbed reference atmosphere in the 15°N to 45°N band before and after the disturbance; (2) models for particular structures during the development of the global-scale phenomenon. Our results show a general increase of particle density and single-scattering albedo inside the storm. However, some discrete features showing anomalous structure and related to the storm peculiar dynamics will also be discussed. Acknowledgments: This work was supported by the Spanish MICIIN project AYA2009-10701 with FEDER funds, by Grupos Gobierno Vasco IT-464-07 and by Universidad País Vasco UPV/EHU through program UFI11/55.

  19. Wavelength-Scale Structures as Extremely High Haze Films for Efficient Polymer Solar Cells.

    Science.gov (United States)

    Ham, Juyoung; Dong, Wan Jae; Jung, Gwan Ho; Lee, Jong-Lam

    2016-03-01

    Wavelength-scale inverted pyramid structures with low reflectance and excellent haze have been designed for application to polymer solar cells (PSCs). The wavelength-scale structured haze films are fabricated on the back surface of glass without damages to organic active layer by using a soft lithographic technique with etched GaN molds. With a rigorous coupled-wave analysis of optical modeling, we find the shift of resonance peaks with the increase of pattern's diameter. Wavelength-scale structures could provide the number of resonances at the long wavelength spectrum (λ = 650-800 nm), yielding enhancement of power conversion efficiency (PCE) in the PSCs. Compared with a flat device (PCE = 7.12%, Jsc = 15.6 mA/cm(2)), improved PCE of 8.41% is achieved in a haze film, which is mainly due to the increased short circuit current density (Jsc) of 17.5 mA/cm(2). Hence, it opens up exciting opportunities for a variety of PSCs with wavelength-scale structures to further improve performance, simplify complicated process, and reduce costs. PMID:26901630

  20. Compositions and pollutant sources of haze in Beijing urban sites.

    Science.gov (United States)

    Wang, Junmei; Song, Yujun; Zuo, Jiangnan; Wu, Hongwen

    2016-05-01

    Haze from urban sites in Beijing was collected with a self-assembled electrostatic dust collector. The sizes and morphologies, thermal properties, and compositions of the particles in the haze were characterized by scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and X-ray photoelectric spectroscopy (XPS), respectively. Based on these results, the causes and pollutant sources of the chemicals in the haze were analyzed, and some countermeasures were further advanced to reduce the related pollutant sources. Graphical abstract ᅟ. PMID:26810665

  1. Organic haze on Titan and the early Earth

    OpenAIRE

    Trainer, Melissa G.; Pavlov, Alexander A.; DeWitt, H. Langley; Jimenez, Jose L.; McKay, Christopher P.; Toon, Owen B.; Tolbert, Margaret A.

    2006-01-01

    Recent exploration by the Cassini/Huygens mission has stimulated a great deal of interest in Saturn's moon, Titan. One of Titan's most captivating features is the thick organic haze layer surrounding the moon, believed to be formed from photochemistry high in the CH4/N2 atmosphere. It has been suggested that a similar haze layer may have formed on the early Earth. Here we report laboratory experiments that demonstrate the properties of haze likely to form through photochemistry on Titan and e...

  2. Regional Haze Evolved from Peat Fires - an Overview

    Science.gov (United States)

    Hu, Yuqi; Rein, Guillermo

    2016-04-01

    This work provides an overview of haze episodes, their cause, emissions and health effects found in the scientific literature. Peatlands, the terrestrial ecosystems resulting from the accumulation of partially decayed vegetation, become susceptible to smouldering fires because of natural droughts or anthropogenic-induced drainages. Once ignited, smouldering peat fires persistently consume large amounts of soil carbon in a flameless form. It is estimated that the average annual carbon gas emissions (mainly CO2 and CO) from peat fires are equivalent to 15% of manmade emissions, representing influential perturbation of global carbon circle. In addition to carbon emissions, smouldering peat fires emit substantial quantities of heterogeneous smoke, which is responsible for haze phenomena, has not yet been fully studied. Peat-fire-derived smoke is characterized by high concentration of particulate matter (PM), ranging from nano-scale ultrafine fraction (PM1, particle diameter transportation, construction, tourism and agriculture-based industries. For example, an unprecedented peatland mega-fire burst on the Indonesian islands Kalimantan and Sumatra during the 1997 El-Niño event, resulting in transboundary smoke-haze disaster. Severe haze events continue to appear in Southeast Asia every few years due to periodical peat fires in this region. In addition, smouldering peat fires have been frequently reported in tropical, temperate and boreal regions (Botswana in 2000, North America in 2004, Scotland in 2006 and Central Russia in 2010 et al.), peat-fire-induced haze has become a regional seasonal phenomenon. Exposure to smoky haze results in deleterious physiologic responses, predominantly to the respiratory and cardiovascular systems. In 1997, an estimation of 100 million people in 5 countries in Southeast Asia were affected by Indonesia haze episode while 20 million people suffered from respiratory problems in Indonesia alone. Fine PM fraction generated from peat fires

  3. Aerosol characterization over the North China Plain: Haze life cycle and biomass burning impacts in summer

    Science.gov (United States)

    Sun, Yele; Jiang, Qi; Xu, Yisheng; Ma, Yan; Zhang, Yingjie; Liu, Xingang; Li, Weijun; Wang, Fei; Li, Jie; Wang, Pucai; Li, Zhanqing

    2016-03-01

    The North China Plain experiences frequent severe haze pollution during all seasons. Here we present the results from a summer campaign that was conducted at Xianghe, a suburban site located between the megacities of Beijing and Tianjin. Aerosol particle composition was measured in situ by an Aerosol Chemical Speciation Monitor along with a suite of collocated measurements during 1-30 June 2013. Our results showed that aerosol composition at the suburban site was overall similar to that observed in Beijing, which was mainly composed of organics (39%), nitrate (20%), and sulfate (18%). Positive matrix factorization of organic aerosol (OA) identified four OA factors with different sources and processes. While secondary organic aerosol dominated OA, on average accounting for 70%, biomass burning OA (BBOA) was also observed to have a considerable contribution (11%) for the entire study period. The contribution of BBOA was increased to 21% during the BB period in late June, indicating a large impact of agricultural burning on air pollution in summer. Biomass burning also exerted a significant impact on aerosol optical properties. It was estimated that ~60% enhancement of absorption at the ultraviolet spectral region was caused by the organic compounds from biomass burning. The formation mechanisms and sources of severe haze pollution episodes were investigated in a case study. The results highlighted two different mechanisms, i.e., regional transport and local sources, driving the haze life cycles differently in summer in the North China Plain. While secondary aerosol species dominated aerosol composition in the episode from regional transport, organics and black carbon comprised the major fraction in the locally formed haze episode.

  4. Detection of haze and/or cloud

    Science.gov (United States)

    Mukai, Sonoyo; Sano, Itaru; Mukai, Makiko; Kokhanovsky, Alexander

    2015-04-01

    It is highly likely that large-scale air pollution will continue to occur because air pollution becomes severe due to both the increasing emissions of the anthropogenic aerosols and the complicated behavior of natural aerosols, especially in Asia. It is natural to consider that incident solar light multiply interacts with the atmospheric aerosols due to dense radiation field in such a heavy haze. Accordingly efficient and practical algorithms for radiation simulation are indispensable to retrieve aerosol characteristics in a hazy atmosphere. It has been shown that aerosol retrieval in the hazy atmosphere is achieved based on MSOS (method of successive order of scattering) [1]. The satellite polarimetric sensor POLDER-1, 2, 3 has shown that the spectro-photopolarimetry of the terrestrial atmosphere is very useful for the observation of the Earth, especially for atmospheric particles. JAXA has been developing the new Earth observing system, GCOM satellite. GCOM-C will board the polarimetric sensor SGLI (second-generation global imager) in 2017. The SGLI has two polarization channels at near-infrared wavelengths of 670 and 870 nm. Furthermore, EUMETSAT plans to collect polarization measurements with a POLDER follow on 3MI/EPS-SG in 2021. Then the efficient algorithms for radiation simulation in the optically thick atmosphere by using polarization information denoted by Stokes parameters are shown in this work. It is of interest to mention that multi-spectral data are available for detection and/or distinction of hazy aerosol and/or cloud. In this work our MSOS is expected to be available for atmospheric particle retrieval in a mixture case of cloud and haze. The MSOS is available for the radiation simulation reflected from the optically semi-infinite atmosphere.[1]. Here we intend to improve MSOS-scalar into more efficient and practical form, and further into MSOS-vector form. We show here that a dense aerosol episode can be well simulated by a semi-infinite radiation

  5. Light extraction efficiency enhancement of GaN-based blue LEDs based on ITO/ InxO ohmic contacts with microstructure formed by annealing in oxygen.

    Science.gov (United States)

    Luo, Yi; Bai, Yiming; Han, Yanjun; Li, Hongtao; Wang, Lai; Wang, Jian; Sun, Changzheng; Hao, Zhibiao; Xiong, Bing

    2016-05-16

    Indium tin oxide (ITO)/ indium oxide (InxO) double layer structure was adopted as the transparent conduction and light scattering function layer to improve the light extraction efficiency of the GaN-based blue LEDs. The double layer structure was first deposited in one run by electron beam evaporation using ITO and Indium as the source respectively, and then annealed in an oxygen environment. This method can fabricate transparent electrode with microstructure and low specific contact resistivity one time free from lithography and etching, which makes the fabrication process simple and at a ower cost. For the 220 nm ITO/ 170 nm InxO double layer sample annealed at 600°C for 15 min in oxygen, measurement results show that its root mean square of roughness of the surface microstructure can be as high as 85.2 nm which introduces the strongest light scattering. Its light transmittance at 450 nm can maintain 92.4%. At the same time, it can realize lower specific contact resistivity with p-InGaN. Compared with the GaN-based blue LEDs with only 220 nm ITO electrode, the light output power of the LEDs with 220 nm ITO/ 170 nm InxO double layer structure can be increased about 58.8%, and working voltage at 20 mA injection current is decreased about 0.23 V due to the enhanced current spreading capability. The light output power improvement is also theoretically convinced by finite difference time domain simulations. PMID:27409953

  6. Blue Nile

    OpenAIRE

    Ramos, Manuel João

    2000-01-01

    The Blue Nile, whose source lies in highland Ethiopia, is known as “Al-Bahr al- Azraq” in Arabic, and as “Abbay” in Amharic. Along with the Atbara, it contributes more than 80 per cent of the Nile’s total water supply, the remainder coming mainly from the White Nile that stretches down to the Great Lakes plateau in Central Africa.

  7. Energetics study of West African dust haze

    International Nuclear Information System (INIS)

    The causes of the large and often persistent negative anomalies of equivalent potential temperature observed in the 900-700 hpa layer and which occurs in association with dust haze outbreaks over Kano in winter is investigated. Energetics results indicate that the primary mechanism for such anomalies is the horizontal transport of drier and, to a lesser extent, colder air at the upper levels by eddy motions, with consequent destabilization of the atmospheric boundary layer over the station. This is suggested as the mobilization mechanism responsible for raising dust from the surface over the Bilma/Faya-Largeau source region much further poleward. Temperature inversions were also found to be more pronounced during dust spells than in clear periods. (author). 18 refs, 6 figs, 2 tabs

  8. Clouds and Hazes in Exoplanet Atmospheres

    CERN Document Server

    Marley, Mark S; Cuzzi, Jeffrey N; Kitzmann, Daniel

    2013-01-01

    Clouds and hazes are commonplace in the atmospheres of solar system planets and are likely ubiquitous in the atmospheres of extrasolar planets as well. Clouds affect every aspect of a planetary atmosphere, from the transport of radiation, to atmospheric chemistry, to dynamics and they influence - if not control - aspects such as surface temperature and habitability. In this review we aim to provide an introduction to the role and properties of clouds in exoplanetary atmospheres. We consider the role clouds play in influencing the spectra of planets as well as their habitability and detectability. We briefly summarize how clouds are treated in terrestrial climate models and consider the far simpler approaches that have been taken so far to model exoplanet clouds, the evidence for which we also review. Since clouds play a major role in the atmospheres of certain classes of brown dwarfs we briefly discuss brown dwarf cloud modeling as well. We also review how the scattering and extinction efficiencies of cloud p...

  9. Exploring the severe winter haze in Beijing

    Directory of Open Access Journals (Sweden)

    G. J. Zheng

    2014-07-01

    Full Text Available Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012–2013, causing major environmental and health problems. To better understand these extreme events, we analyzed the hourly observation data of PM2.5 and its major chemical composition, with support of model simulations. Severe winter haze was shown to result from stable synoptic meteorological conditions over a large part of northeastern China, rather than from an abrupt increase in emissions. Build-up of secondary species, including organics, sulfate, nitrate, and ammonium, was the major driving force behind these polluted periods. The contribution of organic matter decreased with increasing pollution level while sulfate and nitrate contributions increased. Correspondingly, the ratio of secondary organic carbon to elemental carbon decreased and had a stable diurnal pattern during heavily polluted periods, indicating weakened photochemical activity due to the dimming effect of high loading of aerosol particles. Under such conditions, the strong increase in sulfate and nitrate contributions to PM2.5 was attributed to an elevated conversion ratio, reflecting more active heterogeneous reactions with gradually increasing relative humidity. Moreover, we found that high aerosol concentration was a regional phenomenon. The accumulation process of aerosol particles occurred successively from southeast cities to Beijing. The "apparent" sharp increase in PM2.5 concentration of up to several hundred μg m−3 per hour recorded in Beijing represented rapid "recovery" from an "interruption" to the continuous pollution accumulation over the region, rather than purely local chemical production. This suggests that regional transport of pollutants played an important role during these severe pollution events.

  10. Atmospheric Prebiotic Chemistry and Organic Hazes

    Science.gov (United States)

    Trainer, Melissa G.

    2012-01-01

    Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of pre biotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere.

  11. Decadal variability in the occurrence of wintertime haze in central eastern China tied to the Pacific Decadal Oscillation

    Science.gov (United States)

    Zhao, Sen; Li, Jianping; Sun, Cheng

    2016-06-01

    Haze is a serious issue in China with increasing concerns, and understanding the factors driving decadal-scale variations in haze occurrence is relevant for government policymaking. Using a comprehensive observational haze dataset, we demonstrate notable decadal fluctuations in the number of haze days (HD) during winter in central eastern China, showing a decline since the mid-1980s. The leading mode of the wintertime HD features an increasing trend for 1959–2012 in eastern China, highly correlated with China’s gross domestic product (GDP) that represents increasing trend of pollutant emissions, and to a lesser extent meteorological factors. The second mode shows decadal variations in central eastern China associated with Pacific Decadal Oscillation (PDO). Observations and numerical simulations suggest that Mongolia High and corresponding descending motion tend to be enhanced (weakened) in central eastern China during the positive (negative) phase of PDO. With PDO shifting towards a negative phase, the weakened Mongolia High and ascending anomalies make the air unstable and conduce to the spread of pollutants, leading to the decline in the wintertime HD over central eastern China since the mid-1980s. Based on above physical mechanisms, a linear model based on PDO and GDP metrics provided a good fit to the observed HD.

  12. A new structure of p-GaN/InGaN heterojunction to enhance hole injection for blue GaN-based LEDs

    Science.gov (United States)

    Lin, Zhiting; Wang, Haiyan; Lin, Yunhao; Yang, Meijuan; Li, Guoqiang; Xu, Bingshe

    2016-07-01

    A new structure of p-GaN/InGaN heterojunction has been proposed to enhance hole injection for blue GaN-based light-emitting diodes (LEDs). It is demonstrated by the simulation results that a p-GaN (50 nm)/In0.05Ga0.95N (150 nm) heterojunction can make a 25% and 10% increment of hole and electron concentration in the active region, respectively, finally resulting in a 55% improvement on the LED’s radiative recombination intensity. The simulation also reveals that the efficiency droop is alleviated from 32.9% to 21.7% at the current density of 100 A cm‑2. The enhanced hole injection is mainly attributed to the increased average background hole concentration of the area between the p-AlGaN electron blocking layer (EBL) to the p-GaN/InGaN heterojunction. The increasing potential barrier of the conduction band, resulting from the introduction of p-GaN/InGaN heterojunction, would also weaken electron leakage and is favorable to the LED’s luminous performance. The experimental results show that the wall-plug efficiency (WPE) of the p-GaN/InGaN LED increases by 26.0% at the injection current of 75 mA, in spite of the increasing electric resistance, which impairs the improvement of the LED’s performance from the enhanced hole injection. The structure of the p-GaN/InGaN heterojunction is novel in the field of p-type region design, and is a simple but effective way to promote the LED’s performance, which is very promising for application in further high-performance LED fabrication.

  13. Posthuman blues

    CERN Document Server

    Tonnies, Mac

    2013-01-01

    Posthuman Blues, Vol. I is first volume of the edited version of the popular weblog maintained by author Mac Tonnies from 2003 until his tragic death in 2009. Tonnies' blog was a pastiche of his original fiction, reflections on his day-to-day life, trenchant observations of current events, and thoughts on an eclectic range of material he culled from the Internet. What resulted was a remarkably broad portrait of a thoughtful man and the complex times in which he lived, rendered with intellige...

  14. Analysis on the Change Characteristics of Haze in Dezhou City in Recent 40 Years

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to analyze the change characteristics of haze in Dezhou City. [Method] Based on the data of haze and sunshine duration from 11 counties or cities in Dezhou City from 1970 to 2009, the daily, monthly, seasonal and annual variation of haze and their variation reasons were studied, meanwhile, the effects of haze on sunshine duration were discussed. [Result] Haze occurred most frequently from 09:00 to 14:00 and daily variation was different in various seasons; haze days were the most in ...

  15. Effect of operational parameters on the decolorization of C.I. Reactive Blue 19 in aqueous solution by ozone-enhanced electrocoagulation

    International Nuclear Information System (INIS)

    The aim of this paper was to investigate the efficiency of the ozone-enhanced electrocoagulation (EC) process in the decolorization of C.I. Reactive Blue 19 in water using iron electrodes. We determined the effects of various operating parameters such as initial pH, initial dye concentration, current density, salt concentration, temperature, ozone flow rate, and distance between electrodes on decolorization efficiency in a laboratory-scale reactor. Increasing the initial dye concentration decreased the decolorization efficiency, whereas increasing the distance between electrodes increased it. The other operating factors had both positive and negative effects. With an initial pH of 10.0, an initial dye concentration of 100 mg/L, current density of 10 mA/cm2, salt concentration of 3000 mg/L, temperature of 30 deg. C, ozone flow rate of 20 mL/min, and distance between electrodes of 3 cm, over 96% of the color was removed after 10 min. As a consequence, removal of total organic carbon (TOC) was over 80%

  16. Effect of operational parameters on the decolorization of C.I. Reactive Blue 19 in aqueous solution by ozone-enhanced electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Song Shuang; Yao Jie [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); He Zhiqiao [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)], E-mail: zqhe@zjut.edu.cn; Qiu Jianping; Chen Jianmeng [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

    2008-03-21

    The aim of this paper was to investigate the efficiency of the ozone-enhanced electrocoagulation (EC) process in the decolorization of C.I. Reactive Blue 19 in water using iron electrodes. We determined the effects of various operating parameters such as initial pH, initial dye concentration, current density, salt concentration, temperature, ozone flow rate, and distance between electrodes on decolorization efficiency in a laboratory-scale reactor. Increasing the initial dye concentration decreased the decolorization efficiency, whereas increasing the distance between electrodes increased it. The other operating factors had both positive and negative effects. With an initial pH of 10.0, an initial dye concentration of 100 mg/L, current density of 10 mA/cm{sup 2}, salt concentration of 3000 mg/L, temperature of 30 deg. C, ozone flow rate of 20 mL/min, and distance between electrodes of 3 cm, over 96% of the color was removed after 10 min. As a consequence, removal of total organic carbon (TOC) was over 80%.

  17. Size-resolved aerosol chemical analysis of extreme haze pollution events during early 2013 in urban Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Shili; Pan, Yuepeng, E-mail: panyuepeng@mail.iap.ac.cn; Liu, Zirui; Wen, Tianxue; Wang, Yuesi, E-mail: wys@mail.iap.ac.cn

    2014-08-30

    Highlights: • Anthropogenic species substantially accumulated in both fine and coarse particles. • Secondary organic carbon in PM{sub 1.1} decreased from clear to haze days. • The mass peak shifted to larger particles from clear to haze days. • The NO{sub 3}{sup −}/SO{sub 4}{sup 2−} ratio decreased with enhanced haze pollution. • Both mobile local and stationary regional sources were vital for haze formation. - Abstract: Using size-resolved filter sampling and chemical characterization, high concentrations of water-soluble ions, carbonaceous species and heavy metals were found in both fine (PM{sub 2.1}) and coarse (PM{sub 2.1–9}) particles in Beijing during haze events in early 2013. Even on clear days, average mass concentration of submicron particles (PM{sub 1.1}) was several times higher than that previously measured in most of abroad urban areas. A high concentration of particulate matter on haze days weakens the incident solar radiation, which reduces the generation rate of secondary organic carbon in PM{sub 1.1}. We show that the peak mass concentration of particles shifted from 0.43–0.65 μm on clear days to 0.65–1.1 μm on lightly polluted days and to 1.1–2.1 μm on heavily polluted days. The peak shifts were also found for the following species: organic carbon, elemental carbon, NH{sub 4}{sup +}, SO{sub 4}{sup 2−}, NO{sub 3}{sup −}, K, Cu, Zn, Cd and Pb. Our findings demonstrate that secondary inorganic aerosols (36%) and organic matter (26%) dominated the fine particle mass on heavily polluted days, while their contribution reduced to 29% and 18%, respectively, on clear days. Besides fine particles, anthropogenic chemical species also substantially accumulated in the coarse mode, which suggests that particles with aerodynamic diameter larger than 2.1 μm cannot be neglected during severe haze events.

  18. Oxygen vacancy induced photoluminescence properties and enhanced photocatalytic activity of ferromagnetic ZrO2 nanostructures on methylene blue dye under ultra-violet radiation

    International Nuclear Information System (INIS)

    Highlights: • Room temperature ferromagnetism (RTFM) is found in ZrO2 nanostructures. • Oxygen vacancies are found to be the possible reason for the presence of RTFM. • The presence of oxygen vacancies are confirmed by photoluminescence spectra. • Enhanced photocatalytic activity of ZrO2 has been observed for MB dye. • Possible photodegradation mechanism of MB dye has been proposed. - Abstract: Room temperature ferromagnetic (RTFM) ZrO2 nanostructures with tetragonal (t-ZrO2) and monoclinic (m-ZrO2) phases were synthesized by sol–gel method. The photoluminescence (PL) feature of the synthesized samples was investigated using 300 nm excitation wavelength. The decrease of saturation magnetization (Ms) and intensity of emission band at higher calcinations temperature is attributed to the reduction of density of oxygen vacancies in the ZrO2 matrix. The variation of Ms with calcinations temperature follows the same trend as intensity of emission band varies. It further confirms that the presence of RTFM and decrease in emission band intensity is caused due change in density of oxygen vacancies with calcinations temperature. The photocatalytic activity of ZrO2 nanostructures has been investigated on methylene blue (MB) dye as function of particle size under ultra-violet (UV) radiation with 365 nm wavelength. The ZrO2 nanostructures with smaller particle size are found to be efficient for photodegradation of MB dye. Oxygen vacancies are found to be the main cause for enhanced photocatalytic activity of ZrO2 nanostructures

  19. Toward fluorine-free blue-emitting cationic iridium complexes: to generate emission from the cyclometalating ligands with enhanced triplet energy.

    Science.gov (United States)

    He, Lei; Wang, Zhen; Duan, Lian; Yang, Chunpeng; Tang, Ruiren; Song, Xiangzhi; Pan, Chunyue

    2016-04-01

    A route toward fluorine-free blue-emitting cationic iridium complexes, to generate emission from the cyclometalating ligands with enhanced triplet energy, has been proposed and demonstrated. Attaching electron-donating groups to the pyridine moieties of the ppy-type cyclometalating ligands (Hppy is 2-phenylpyridine) enhances the triplet ((3)π-π*) energy of the ligand, and the use of electron-rich or non-conjugated ancillary ligands ensures that the emission is generated from the (3)π-π* states of cyclometalating ligands. By this molecular design, [Ir(buoppy)2(pzpy)]PF6 (1) and [Ir(buoppy)2(bim-cb)]PF6 (2) have been developed, with 4-butoxy-2-phenylpyridine (buoppy) as the cyclometalating ligand and electron-rich 2-(1H-pyrazol-1-yl)pyridine (pzpy) or non-conjugated N-heterocyclic dicarbene (bim-cb) as the ancillary ligands. Complexes 1 and 2 give emission with major emission peaks around 465 nm, which is among the bluest reported for fluorine-free cationic iridium complexes. For both complexes, the emission is generated from the (3)π-π* states centered on buoppy. For complex 1, the charge-transfer (Ir/buoppy → pzpy) state is dominated by non-radiative deactivation and it behaves as a non-radiative deactivation channel for the emissive buoppy-centered (3)π-π* states which lies close to the charge-transfer state in energy. Such a non-radiative deactivation channel is largely suppressed in the rigid matrix, and is eliminated in complex 2 with a non-conjugated dicarbene ancillary ligand. PMID:26918443

  20. Determination and analysis of trace metals and surfactant in air particulate matter during biomass burning haze episode in Malaysia

    Science.gov (United States)

    Ahmed, Manan; Guo, Xinxin; Zhao, Xing-Min

    2016-09-01

    Trace metal species and surface active agent (surfactant) emitted into the atmosphere from natural and anthropogenic source can cause various health related and environmental problems. Limited data exists for determinations of atmospheric particulate matter particularly trace metals and surfactant concentration in Malaysia during biomass burning haze episode. We used simple and validated effective methodology for the determination of trace metals and surfactant in atmospheric particulate matter (TSP & PM2.5) collected during the biomass burning haze episode in Kampar, Malaysia from end of August to October 2015. Colorimetric method of analysis was undertaken to determine the concentration of anionic surfactant as methylene blue active substance (MBAS) and cationic surfactant as disulphine blue active substance (DBAS) using a UV-Visible spectrophotometer. Particulate samples were also analyzed for trace metals with inductive coupled plasma mass spectrometer (ICP-MS) followed by extraction from glass microfiber filters with close vessel microwave acid digestion. The result showed that the concentrations of surfactant in both samples (TSP & PM2.5) were dominated by MBAS (0.147-4.626 mmol/m3) rather than DBAS (0.111-0.671 mmol/m3) and higher than the other researcher found. Iron (147.31-1381.19 μg/m3) was recorded leading trace metal in PM followed by Al, Zn, Pb, Cd, Cr and others. During the haze period the highest mass concentration of TSP 313.34 μg/m3 and 191.07 μg/m3 for PM2.5 were recorded. Furthermore, the backward air trajectories from Kampar in north of peninsular Malaysia confirmed that nearly all the winds paths originate from Sumatera and Kalimantan, Indonesia.

  1. Elucidating severe urban haze formation in China

    Science.gov (United States)

    Guo, Song; Hu, Min; Zamora, Misti L.; Peng, Jianfei; Shang, Dongjie; Zheng, Jing; Du, Zhuofei; Wu, Zhijun; Shao, Min; Zeng, Limin; Molina, Mario J.; Zhang, Renyi

    2014-12-01

    As the world's second largest economy, China has experienced severe haze pollution, with fine particulate matter (PM) recently reaching unprecedentedly high levels across many cities, and an understanding of the PM formation mechanism is critical in the development of efficient mediation policies to minimize its regional to global impacts. We demonstrate a periodic cycle of PM episodes in Beijing that is governed by meteorological conditions and characterized by two distinct aerosol formation processes of nucleation and growth, but with a small contribution from primary emissions and regional transport of particles. Nucleation consistently precedes a polluted period, producing a high number concentration of nano-sized particles under clean conditions. Accumulation of the particle mass concentration exceeding several hundred micrograms per cubic meter is accompanied by a continuous size growth from the nucleation-mode particles over multiple days to yield numerous larger particles, distinctive from the aerosol formation typically observed in other regions worldwide. The particle compositions in Beijing, on the other hand, exhibit a similarity to those commonly measured in many global areas, consistent with the chemical constituents dominated by secondary aerosol formation. Our results highlight that regulatory controls of gaseous emissions for volatile organic compounds and nitrogen oxides from local transportation and sulfur dioxide from regional industrial sources represent the key steps to reduce the urban PM level in China.

  2. Size-resolved source apportionment of particulate matter in urban Beijing during haze and non-haze episodes

    Science.gov (United States)

    Tian, S. L.; Pan, Y. P.; Wang, Y. S.

    2016-01-01

    Additional size-resolved chemical information is needed before the physicochemical characteristics and sources of airborne particles can be understood; however, this information remains unavailable in most regions of China due to lacking measurement data. In this study, we report observations of various chemical species in size-segregated particle samples that were collected over 1 year in the urban area of Beijing, a megacity that experiences severe haze episodes. In addition to fine particles, high concentrations of coarse particles were measured during the periods of haze. The abundance and chemical compositions of the particles in this study were temporally and spatially variable, with major contributions from organic matter and secondary inorganic aerosols. The contributions of organic matter to the particle mass decreased from 37.9 to 31.2 %, and the total contribution of sulfate, nitrate and ammonium increased from 19.1 to 33.9 % between non-haze and haze days, respectively. Due to heterogeneous reactions and hygroscopic growth, the peak concentrations of the organic carbon, cadmium and sulfate, nitrate, ammonium, chloride and potassium shifted from 0.43 to 0.65 µm on non-haze days to 0.65-1.1 µm on haze days. Although the size distributions of lead and thallium were similar during the observation period, their concentrations increased by a factor of more than 1.5 on haze days compared with non-haze days. We observed that sulfate and ammonium, which have a size range of 0.43-0.65 µm, sulfate and nitrate, which have a size range of 0.65-1.1 µm, calcium, which has a size range of 5.8-9 µm, and the meteorological factors of relative humidity and wind speed were responsible for haze pollution when the visibility was less than 10 km. Source apportionment using Positive Matrix Factorization showed six PM2.1 sources and seven PM2.1-9 common sources: secondary inorganic aerosol (25.1 % for fine particles vs. 9.8 % for coarse particles), coal combustion (17

  3. The impact of haze on the adolescent's acute respiratory disease: A single institution study

    Directory of Open Access Journals (Sweden)

    Wan Fairos Wan Yaacob

    2016-05-01

    Conclusions: Student with haze effect documented much higher symptoms during haze especially female students. Symptoms such as headache, wheezing and mucus were noted among the normal secondary school children in Kota Bharu.

  4. 77 FR 24952 - Agency Information Collection Activities; Proposed Collection; Comment Request; Regional Haze...

    Science.gov (United States)

    2012-04-26

    ... ICR (August 26, 2009; 74 FR 43118). The last collection request anticipated the program progressing... AGENCY Agency Information Collection Activities; Proposed Collection; Comment Request; Regional Haze... organizations and facilities potentially regulated under the regional haze rule. Title: Regional...

  5. Enhanced amperometric response of a glucose oxidase and horseradish peroxidase based bienzyme glucose biosensor modified with a film of polymerized toluidine blue containing reduced graphene oxide

    International Nuclear Information System (INIS)

    Reduced graphene oxide (RGO) was used to construct a bienzyme biosensor containing horseradish peroxidase (HRP) and glucose oxidase (GOx). A poly(toluidine blue) (pTB) film containing RGO acted as both enzyme immobilization matrix and electron transfer mediator. The bienzyme biosensor was characterized by electrochemical techniques and displays a highly sensitive amperometric response to glucose and hydrogen peroxide (H2O2) at a potential as low as −0.1 V (vs. SCE). It is shown that use of RGO causes a strong enhancement on the amperometric responses. H2O2 formed by the action of GOx in the presence of oxygen can be further reduced by HRP in the pTB film contacting the RGO modified electrode. In the absence of oxygen, glucose oxidation proceeds by another mechanism in which electron transfer occurs from GOx to the electrode and with pTB acting as the mediator. Amperometric responses to glucose and H2O2 follow Michaelis-Menten kinetics. The experimental conditions were optimized, and under these conditions glucose can be determined in the 80 μM to 3.0 mM range with a detection limit of 50 μM. H2O2, in turn, can be quantified in up to 30.0 μM concentration with a detection limit of 0.2 μM. The bienzyme biosensor is reproducible, repeatable and stable. Finally, it has been successfully applied to the determination of glucose in plasma samples. (author)

  6. A critical evaluation of the ability of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) thermal infrared red-green-blue rendering to identify dust events: Theoretical analysis

    Science.gov (United States)

    Brindley, Helen; Knippertz, Peter; Ryder, Claire; Ashpole, Ian

    2012-04-01

    Using a combination of idealized radiative transfer simulations and a case study from the first field campaign of the Saharan Mineral Dust Experiment (SAMUM) in southern Morocco, this paper provides a systematic assessment of the limitations of the widely used Spinning Enhanced Visible and Infrared Imager (SEVIRI) red-green-blue (RGB) thermal infrared dust product. Both analyses indicate that the ability of the product to identify dust, via its characteristic pink coloring, is strongly dependent on the column water vapor, the lower tropospheric lapse rate, and dust altitude. In particular, when column water vapor exceeds ˜20-25 mm, dust presence, even for visible optical depths of the order 0.8, is effectively masked. Variability in dust optical properties also has a marked impact on the imagery, primarily as a result of variability in dust composition. There is a moderate sensitivity to the satellite viewing geometry, particularly in moist conditions. The underlying surface can act to confound the signal seen through variations in spectral emissivity, which are predominantly manifested in the 8.7μm SEVIRI channel. In addition, if a temperature inversion is present, typical of early morning conditions over the Sahara and Sahel, an increased dust loading can actually reduce the pink coloring of the RGB image compared to pristine conditions. Attempts to match specific SEVIRI observations to simulations using SAMUM measurements are challenging because of high uncertainties in surface skin temperature and emissivity. Recommendations concerning the use and interpretation of the SEVIRI RGB imagery are provided on the basis of these findings.

  7. Enhancing the Applicability of Satellite Remote Sensing for PM2.5 Estimation Using MODIS Deep Blue AOD and Land Use Regression in California, United States.

    Science.gov (United States)

    Lee, Hyung Joo; Chatfield, Robert B; Strawa, Anthony W

    2016-06-21

    We estimated daily ground-level PM2.5 concentrations combining Collection 6 deep blue (DB) Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) data (10 km resolution) with land use regression in California, United States, for the period 2006-2012. The Collection 6 DB method for AOD provided more reliable data retrievals over California's bright surface areas than previous data sets. Our DB AOD and PM2.5 data suggested that the PM2.5 predictability could be enhanced by temporally varying PM2.5 and AOD relations at least at a seasonal scale. In this study, we used a mixed effects model that allowed daily variations in DB AOD-PM2.5 relations. Because DB AOD might less effectively represent local source emissions compared to regional ones, we added geographic information system (GIS) predictors into the mixed effects model to further explain PM2.5 concentrations influenced by local sources. A cross validation (CV) mixed effects model revealed reasonably high predictive power for PM2.5 concentrations with R(2) = 0.66. The relations between DB AOD and PM2.5 considerably varied by day, and seasonally varying effects of GIS predictors on PM2.5 suggest season-specific source emissions and atmospheric conditions. This study indicates that DB AOD in combination with land use regression can be particularly useful to generate spatially resolved PM2.5 estimates. This may reduce exposure errors for health effect studies in California. We expect that more detailed PM2.5 concentration patterns can help air quality management plan to meet air quality standards more effectively. PMID:27218887

  8. Size-resolved source apportionment of particulate matter in urban Beijing during haze and non-haze episodes

    Directory of Open Access Journals (Sweden)

    S. L. Tian

    2015-03-01

    Full Text Available More size-resolved chemical information is needed before the physicochemical characteristics and sources of airborne particles can be understood, but this information remains unavailable in most regions of China due to a paucity of measurement data. In this study, we report a one-year observation of various chemical species in size-segregated particle samples collected in urban Beijing, a mega city that experiences severe haze episodes. In addition to fine particles, the measured particle size distributions showed high concentrations of coarse particles during the haze periods. The abundance and chemical compositions of the particles in this study were temporally and spatially variable, with major contributions from organic matter and secondary inorganic aerosols. The contribution of the organic matter to the mass decreased from 37.9 to 33.1%, whereas the total contribution of SO42−, NO3− and NH4+ increased from 19.1 to 32.3% on non-haze and haze days, respectively. Due to heterogeneous reactions and hygroscopic growth, the peaks in the size distributions of organic carbon, SO42−, NO3−, NH4+, Cl−, K+ and Cu shifted from 0.43–0.65 μm on non-haze days to 0.65–1.1 μm on haze days. Although the size distributions are similar for the heavy metals Pb, Cd and Tl during the observation period, their concentrations increased by a factor of more than 1.5 on haze days compared with non-haze days. We found that NH4+ with a size range of 0.43–0.65 μm, SO42− and NO3− with a size range of 0.65–1.1 μm and Ca2+ with a size range of 5.8–9 μm as well as the meteorological factors of relative humidity and wind speed were responsible for the haze pollution when the visibility was less than 15 km. Source apportionment using positive matrix factorization identified six common sources: secondary inorganic aerosols (26.1% for fine particles vs. 9.5% for coarse particles, coal combustion (19 vs. 23.6%, primary emissions from vehicles (5.9 vs

  9. Size-resolved source apportionment of particulate matter in urban Beijing during haze and non-haze episodes

    Science.gov (United States)

    Tian, S. L.; Pan, Y. P.; Wang, Y. S.

    2015-03-01

    More size-resolved chemical information is needed before the physicochemical characteristics and sources of airborne particles can be understood, but this information remains unavailable in most regions of China due to a paucity of measurement data. In this study, we report a one-year observation of various chemical species in size-segregated particle samples collected in urban Beijing, a mega city that experiences severe haze episodes. In addition to fine particles, the measured particle size distributions showed high concentrations of coarse particles during the haze periods. The abundance and chemical compositions of the particles in this study were temporally and spatially variable, with major contributions from organic matter and secondary inorganic aerosols. The contribution of the organic matter to the mass decreased from 37.9 to 33.1%, whereas the total contribution of SO42-, NO3- and NH4+ increased from 19.1 to 32.3% on non-haze and haze days, respectively. Due to heterogeneous reactions and hygroscopic growth, the peaks in the size distributions of organic carbon, SO42-, NO3-, NH4+, Cl-, K+ and Cu shifted from 0.43-0.65 μm on non-haze days to 0.65-1.1 μm on haze days. Although the size distributions are similar for the heavy metals Pb, Cd and Tl during the observation period, their concentrations increased by a factor of more than 1.5 on haze days compared with non-haze days. We found that NH4+ with a size range of 0.43-0.65 μm, SO42- and NO3- with a size range of 0.65-1.1 μm and Ca2+ with a size range of 5.8-9 μm as well as the meteorological factors of relative humidity and wind speed were responsible for the haze pollution when the visibility was less than 15 km. Source apportionment using positive matrix factorization identified six common sources: secondary inorganic aerosols (26.1% for fine particles vs. 9.5% for coarse particles), coal combustion (19 vs. 23.6%), primary emissions from vehicles (5.9 vs. 8.0%), biomass burning (8.5 vs. 2

  10. Study on the Variation Characteristics of Haze Weather in Hubei Province during 1980-2012

    Institute of Scientific and Technical Information of China (English)

    Tianxing SU; Mingfang XU; Xiang ZHOU; Zaiqiang YANG; Jijian YUAN; Haiyan ZHANG

    2015-01-01

    This paper, using the method of "the combination of 14 o ’clock relative humidity, visibility and weather phenomena" , selected haze days during 1980-2012 from 13 stations of Hubei Province, and studied years of variation characteristics of haze weather in Hubei Province. The results showed that the average annual haze days showed a fluctuant rising trend in whole from 1980 to 2012, but there were many peak value and val ey value during the whole changing process; haze days of most stations showed an increasing trend, among which the stations with less than 50 d haze days had a more obvious increasing trend, and the spatial distribution of annual mean haze days had distinct inhomogeneity. Haze days of Hubei Province presented the distribution characteristics of more in autumn and winter, and less in spring and summer, in which haze days during December-January were the most, and haze days during July -August were the least. Terrain had a big impact on lo-cal haze days, piedmont leeward zones were prone to haze days, mountainous re-gions were just the opposite. The research suggested that we should combine dif-ferent situations with different stations instead of exclusively from the mean value of multiple stations when we analyze the mean change of haze days in a broader area, to investigate the overal changing trend and the reasons.

  11. 78 FR 46141 - Approval and Disapproval of Air Quality State Implementation Plans; Arizona; Regional Haze and...

    Science.gov (United States)

    2013-07-30

    ... until we received Arizona's final Regional Haze SIP. 77 FR 66398, November 5, 2012. II. Review of State..., instead of under section 309. \\18\\ 74 FR 2392. ADEQ adopted and transmitted its 2011 Regional Haze SIP... Class I area and, therefore, must submit regional haze SIPs.'' 64 FR 35720; see also 40 CFR...

  12. 78 FR 40654 - Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze...

    Science.gov (United States)

    2013-07-08

    ... partially approving and partially disapproving Wyoming's 40 CFR 51.309(g) regional haze SIP. 78 FR 34738. In.... at both locations. The comment period for the proposed rule published June 10, 2013 at 78 FR 34738 is...; Regional Haze State Implementation Plan; Federal Implementation Plan for Regional Haze; Notice of...

  13. 77 FR 3975 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Regional Haze

    Science.gov (United States)

    2012-01-26

    ... regional haze issues. EPA promulgated a rule to address regional haze, the RHR, on July ] 1, 1999 (64 FR... regulations issued in 2005 revising the regional haze program. 70 FR 39104 (July 6, 2005). EPA's regulations...-fifth of the visual range that would exist under estimated natural conditions. See 64 FR 35715 (July...

  14. 76 FR 33662 - Approval and Promulgation of Air Quality Implementation Plans; State of Tennessee; Regional Haze...

    Science.gov (United States)

    2011-06-09

    ... address regional haze issues. EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713... revising the regional haze program, EPA made just such a demonstration for CAIR. See 70 FR 39104 (July 6... FR 39104, 39142-4143 (July 6, 2005). CAIR, as originally promulgated, requires significant...

  15. 78 FR 8083 - Partial Disapproval of State Implementation Plan; Arizona; Regional Haze Requirements

    Science.gov (United States)

    2013-02-05

    ... regional haze on July 1, 1999. 64 FR 35714 (July 1, 1999) codified at ] 40 CFR part 51, subpart P (Regional... of the required SIP submissions to address regional haze. See 74 FR 2392. Specifically, EPA found... Arizona's 309 Regional Haze SIP, if finalized, will not create a new FIP obligation.\\18\\ \\16\\ 74 FR...

  16. 77 FR 11452 - Approval and Promulgation of Air Quality Implementation Plans; State of Georgia; Regional Haze...

    Science.gov (United States)

    2012-02-27

    ... submittal arising from the State's reliance on CAIR to meet certain regional haze requirements. See 76 FR... promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713), the RHR. The RHR revised the... ] revising the regional haze program, EPA made just such a demonstration for CAIR. See 70 FR 39104 (July...

  17. 77 FR 30932 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Regional Haze

    Science.gov (United States)

    2012-05-24

    .... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional Haze Rule... the Regional Haze Rule, Part II, How to Identify BART-Eligible Sources. See 70 FR 39158. This guidance... the visual range that would exist under estimated natural conditions. See 64 FR 35715 (July 1,...

  18. 77 FR 71111 - Approval and Promulgation of Air Quality Implementation Plans; State of Florida; Regional Haze...

    Science.gov (United States)

    2012-11-29

    ... regional haze on July 1, 1999 (64 FR 35713), the Regional Haze Rule (RHR). The RHR revised the existing... haze SIP, and on June 7, 2012 (77 FR 33642), the EPA finalized a limited disapproval of the regional... of sources, i.e., ``reasonably attributable visibility impairment.'' See 45 FR 80084....

  19. 77 FR 33021 - Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze...

    Science.gov (United States)

    2012-06-04

    ... address regional haze issues. EPA promulgated a rule to address regional haze on July 1, 1999. 64 FR 35714... addressing the regional haze requirements. 74 FR 2392. Once EPA has found that a state has failed to make a... conditions. 64 FR 35715 (July 1, 1999). \\1\\ Visual range is the greatest distance, in kilometers or miles,...

  20. 76 FR 76646 - Approval and Promulgation of Implementation Plans; South Dakota; Regional Haze State...

    Science.gov (United States)

    2011-12-08

    .... 64 FR 35714 (July 1, 1999), codified at 40 CFR part 51, subpart P. The Regional Haze Rule revised the... the regional ] haze requirements. 74 FR 2392. Once EPA has found that a state has failed to make a...\\ The preamble to the Regional Haze Rule provides additional details about the deciview. 64 FR...

  1. 77 FR 46911 - Approval and Promulgation of Air Quality Implementation Plans; Michigan; Regional Haze State...

    Science.gov (United States)

    2012-08-06

    ... July 1, 1999 (64 FR 35713). The regional haze rule, which amended 40 CFR part 50, subpart P, integrated... haze rule provides additional details about the deciview. 64 FR 35714 (July 1, 1999). To track changes... which revised the regional haze program. 70 FR 39104 (July 6, 2005). EPA's regulations provided...

  2. 77 FR 11928 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Regional Haze

    Science.gov (United States)

    2012-02-28

    ... regional haze issues. EPA promulgated a rule to address regional haze, the RHR, on July 1, 1999 (64 FR... issued in 2005 revising the regional haze program. 70 FR 39104 ] (July 6, 2005). EPA's regulations... would exist under estimated natural conditions. See 64 FR 35715 (July 1, 1999). \\1\\ Areas designated...

  3. 77 FR 34801 - Approval and Promulgation of Air Quality Implementation Plans; Minnesota; Regional Haze

    Science.gov (United States)

    2012-06-12

    ... haze plan on January 25, 2012 (77 FR 3681). The proposed rule described the nature of the regional haze... July 1, 1999 RHR (64 FR 35714) required states to submit a regional haze plan by December 17, 2007... (RHR) as codified at 40 CFR 51.308. This rule was promulgated on July 1, 1999 (64 FR 35713),...

  4. 78 FR 5158 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Regional Haze

    Science.gov (United States)

    2013-01-24

    ... rule to address regional haze on July 1, 1999 (64 FR 35714) (``the Regional Haze Rule''). The... Connecticut Regional Haze SIP. See 77 FR 12367. \\1\\ Areas designated as mandatory Class I Federal areas..., promulgated a list of 156 areas where visibility is identified as an important value (44 FR 69122, November...

  5. 40 CFR Appendix Y to Part 51 - Guidelines for BART Determinations Under the Regional Haze Rule

    Science.gov (United States)

    2010-07-01

    ... regional haze rule is found in this part at 40 CFR 51.300 through 51.309. These regulations require, in 40... regional haze rule slightly modified 40 CFR 51.300 through 51.307, including the addition of a few... during the August 7, 1962 to August 7, 1977 time period. 2. Under the regional haze regulations at 40...

  6. 77 FR 17367 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Regional Haze

    Science.gov (United States)

    2012-03-26

    .... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional Haze Rule... significance to be assigned to each factor. See 70 FR 39170 (July 6, 2005). A regional haze SIP must include... the visual range that would exist under estimated natural conditions. See 64 FR 35715 (July 1,...

  7. 76 FR 58569 - Approval and Promulgation of Implementation Plans; North Dakota; Regional Haze State...

    Science.gov (United States)

    2011-09-21

    ... 1999. 64 FR 35714 (July 1, 1999), codified at 40 CFR part 51, subpart P. The Regional Haze Rule revised... the regional haze requirements. 74 FR 2392. Once EPA has found that a State has failed to make a.... See 70 FR 39104, 39118. This visibility metric expresses uniform changes in the degree of haze...

  8. 77 FR 30454 - Approval and Promulgation of Implementation Plans; State of Oregon; Regional Haze State...

    Science.gov (United States)

    2012-05-23

    ... approved certain provisions in Oregon's Regional Haze SIP submission. 76 FR 38997. This previous action... regional haze on July 1, 1999 (64 FR 35713) (the regional haze rule or RHR). The RHR revised the existing... (BART). 76 FR 38997. The action in this Federal Register notice addresses the remaining requirements...

  9. 77 FR 73926 - Approval and Promulgation of State Implementation Plans; State of Wyoming; Regional Haze Rule...

    Science.gov (United States)

    2012-12-12

    ... authority to address, as appropriate, disproportionate human health or environmental effects, using... regional haze issues, and we promulgated regulations addressing regional haze in 1999. 64 FR 35714 (July 1... Haze Rule Requirements for Mandatory Class I Areas Under 40 CFR 51.309 AGENCY: Environmental...

  10. 77 FR 76173 - Approval and Promulgation of Implementation Plans; State of Washington; Regional Haze State...

    Science.gov (United States)

    2012-12-26

    ... cause serious health effects and mortality in humans, and contributes to environmental effects such as... address regional haze on July 1, 1999 (64 FR 35713) (the Regional Haze Rule or RHR). The RHR revised the... Implementation Plans; State of Washington; Regional Haze State Implementation Plan; Federal Implementation...

  11. Aerosols optical propertites in Titan's Detached Haze Layer

    Science.gov (United States)

    Seignovert, Benoît; Rannou, Pascal; Lavvas, Panayotis; Cours, Thibaud; West, Robert A.

    2016-06-01

    Titan's Detached Haze Layer (DHL) first observed in 1983 by Rages and Pollack during the Voyager 2 [1] is a consistent spherical haze feature surrounding Titan's upper atmosphere and detached from the main haze. Since 2005, the Imaging Science Subsystem (ISS) instrument on board the Cassini mission performs a continuous survey of the Titan's atmosphere and confirmed its persistence at 500 km up to the equinox (2009) before its drop and disappearance in 2012 [2]. Previous analyses showed, that this layer corresponds to the transition area between small spherical aerosols and large fractal aggregates and play a key role in the aerosols formation in Titan's atmosphere [3-5]. In this study we perform UV photometric analyses on ISS observations taken from 2005 to 2007 based on radiative transfer inversion to retrieve aerosols particles properties in the DHL (bulk and monomer size, fractal dimension and local density).

  12. Mechanistic Studies of Planetary Haze Formation

    Science.gov (United States)

    Hicks, Raea Kay

    2015-10-01

    Planetary atmospheres can be thought of as global-scale reactors capable of synthesizing large, complex molecules from small gases such as methane (CH4), carbon dioxide (CO2), and nitrogen (N2). The atmosphere of Titan, the largest moon of Saturn covered by a thick organic haze, contains trace amounts (2%) of CH4 in an atmosphere of N2 at a surface pressure of 1.5 bar. This is similar to the Earth's Archaean atmosphere, which possibly contained trace amounts of CH4 and CO2 (˜1,000 ppmv each) in an N2 -dominant atmosphere before the rise of biogenic oxygen. Laboratory simulations of the atmospheric chemistry on Titan and the early Earth have shown that these atmospheres are capable of generating biologically-relevant molecules that condense to form particles which can then settle to the surface of the planetary body, possibly providing the molecules required for the emergence of life. The work presented here examines the mechanisms by which FUV photochemistry initiates incorporation of N atoms into Titan aerosol analogs, and C atoms into early Earth aerosol analogs. Results from the Aerosol Collector and Pyrolyser onboard the Huygens lander reveal the presence of nitrogen in Titan's aerosols. This nitrogen incorporation is thought to occur primarily by extreme-UV photons or energetic electrons. However, recent results from our laboratory indicate a surprising amount of nitrogen incorporation- up to 16% by mass- in Titan aerosol analogs produced by photochemistry initiated by FUV irradiation of CH4/N 2 mixtures. The termolecular reaction CH+N2 +M → HCN2 has been proposed to account for this observation. Here, we test this hypothesis by using a high- resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) to measure the mass loading and chemical composition of aerosol produced at a range of pressures from roughly 0.1 to 1 atm. We report a 10-fold increase in aerosol mass loading across the range of pressures studied, indicating that the mechanism

  13. Radiative effects of tropospheric aerosols on the evolution of the atmospheric boundary layer and its feedback on the haze formation

    Science.gov (United States)

    Wei, Chao; Su, Hang; Cheng, Yafang

    2016-04-01

    Planetary boundary layer (PBL) plays a key role in air pollution dispersion and influences day-to-day air quality. Some studies suggest that high aerosol loadings during severe haze events may modify PBL dynamics by radiative effects and hence enhance the development of haze. This study mainly investigates the radiative effects of tropospheric aerosols on the evolution of the atmospheric boundary layer by conducting simulations with Weather Research and Forecasting single-column model (WRF-SCM). We find that high aerosol loading in PBL depressed boundary layer height (PBLH). But the magnitude of the changes of PBLH after adding aerosol loadings in our simulations are small and can't explain extreme high aerosol concentrations observed. We also investigate the impacts of the initial temperature and moisture profiles on the evolution of PBL. Our studies show that the impact of the vertical profile of moisture is comparable with aerosol effects.

  14. Aerosol physicochemical properties and implication for visibility during an intense haze episode during winter in Beijing

    Directory of Open Access Journals (Sweden)

    Y. H. Wang

    2014-09-01

    Full Text Available The evolution of physical, chemical and optical properties of urban aerosol particles was characterized during an extreme haze episode in Beijing, PRC from 24 January through 31 January 2013 based on in-situ measurements. The average mass concentrations of PM1, PM2.5 and PM10 were 99 ± 67 μg m−3 (average ± stdev, 188 ± 128 μg m−3 and 265 ± 157 μg m−3, respectively. A significant increase in PM1−2.5 fraction was observed during the most heavily polluted periods. The average scattering coefficient (λ = 550 nm was 877 ± 624 M m−1. An increasing relative amount of coarse particles can be deduced from the variations of backscattering ratios, asymmetry parameter and scattering Ångström exponent. Particle number size distributions between 14 nm and 2500 nm diameter showed high number concentrations, particularly in the nucleation mode and accumulation modes. Size-resolved chemical composition of submicron aerosol from a High Resolution-ToF-Aerosol Mass Spectrometer showed that the mass concentration of organic, sulfate, nitrate, ammonium and chlorine mainly resided on 500 nm to 800 nm (vacuum diameter particles, and sulfate and ammonium contributed most to particle growth during the most heavily polluted day (28 January. Increasing relative humidity and stable synoptic conditions on 28 January combined with heavy pollution, lead to enhanced water uptake by the hygroscopic submicron particles and formation of secondary aerosol, maybe the main reasons for the severity of the haze episode. Light scattering apportionment showed that organic, ammonium sulfate, ammonium nitrate and ammonium chloride compounds contributed to light scattering fractions of 57%, 23%, 10% and 10%, respectively. This study indicated that the organic component in submicron aerosol plays an important role in visibility degradation in this haze episode in and around Beijing.

  15. Urban Heat Islands in China Enhanced by Haze Pollution

    Science.gov (United States)

    Cao, C.; Lee, X.; Liu, S.; Oleson, K. W.; Schultz, N. M.; Xiao, W.; Zhang, M.; Zhao, L.

    2015-12-01

    Land conversion from natural surfaces to artificial urban structures has led to the phenomenon of urban heat island (UHI). The intensity of UHI is thought to be controlled primarily by biophysical factors such as changes in albedo, aerodynamic resistance and evapotranspiration, while influences of biogeochemical factors such as aerosol pollution have long been ignored. We hypothesize that increased downward longwave radiation associated with anthropogenic aerosols in urban air will exacerbate nighttime UHI intensity. Here we tested this hypothesis by using the MODIS satellite land surface temperature product and the Community Land Model (CLM) for 39 cities in China. Our results showed that in contrast to observations in North America and elsewhere, nighttime surface UHI of these Chinese cities (3.34 K) was greater than daytime UHI (2.06 K). Variations in the nighttime UHI among the cities were positively correlated with difference in the aerosol optical depth between urban and the adjacent rural area (confidence level p benefit by reducing UHI-related heat stress on urban residents.

  16. Development of textured ZnO-coated low-cost glass substrate with very high haze ratio for silicon-based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hongsingthong, Aswin, E-mail: aswin.hongsingthong@nectec.or.th [Solar Energy Technology Laboratory, National Electronics and Computer Technology Center, 112 Thailand Science Park, Phahonyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120 (Thailand); Krajangsang, Taweewat; Limmanee, Amornrat; Sriprapha, Kobsak; Sritharathikhun, Jaran [Solar Energy Technology Laboratory, National Electronics and Computer Technology Center, 112 Thailand Science Park, Phahonyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120 (Thailand); Konagai, Makoto [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, NE-15, O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2013-06-30

    Zinc oxide (ZnO) films with a very high haze ratio and low resistivity were developed on soda–lime glass substrate by using reactive ion etching (RIE) treatment with carbon tetrafluoride (CF{sub 4}) to modify the substrate surface morphology before the deposition of ZnO films. We found that the surface morphology of the ZnO films deposited by metal organic chemical vapor deposition (MOCVD) technique could be modified by varying the glass treatment conditions and the gas pressure was a key parameter. With increasing glass-etching pressure, the surface morphology of the ZnO films changed from conventional pyramid-like single texture to greater cauliflower-like double texture, leading to significant increases in root mean square roughness and haze ratio of the films. By employing the developed high-haze ZnO films as a front transparent conductive oxide (TCO) layer in microcrystalline silicon solar cells, an enhancement in the quantum efficiency in the long-wavelength region has been achieved. Experimental results have verified that our unique and original glass etching treatment is a simple and effective technique to improve the light-scattering properties of the ZnO films while preserving their good transparency and electrical properties. Thus, the ZnO films deposited on etched soda–lime glass have a high potential for the use as a front TCO layer in thin-film Si solar cells. - Highlights: • High-haze zinc oxide (ZnO) grown on low cost soda–lime glass has been developed. • Surface of the ZnO can be modified by varying glass-substrate etching conditions. • Glass-etching pressure is a key to increase haze ratio of the ZnO films. • Higher cell efficiency has been achieved from cell using etched glass. • High-haze ZnO coated glass is a promising transparent conductive oxide coated glass.

  17. Hazing in orientation programmes in boys-only secondary schools

    Directory of Open Access Journals (Sweden)

    C Huysamer

    2013-01-01

    Full Text Available Hazing, associated with initiation, aims at taking newcomers from novice status to a status of functional and acknowledged members of a new group. However, the process is often dangerous, injurious, and usually secretive. Hazing may occur as an unauthorised component of institutionally sanctioned orientation programmes commonly held for new students at educational institutions at the beginning of the academic year. This study focuses on the occurrence of hazing elements in orientation programmes (OP for Grade 8 boys primarily run by Grade 12 learners in boys-only secondary schools in South Africa. A cross-sectional survey was conducted by administering a researcher-designed questionnaire to a non-probabilistic sample of 296 Grade 12 learners enrolled at three boys-only secondary schools in Johannesburg. The computer assisted analysis strategy included frequency distributions, exploratory factor analysis, and analysis of variance. Findings indicated that respondents generally agreed with regard to the structure, aims, and behaviours common to orientation programmes. Respondents strongly disagreed about the occurrence of physical and sexual abuse and activities aimed at discomfort in the OP; however, respondents showed ambivalence about the occurrence of certain activities, which may deteriorate into hazing. Prior experience of an orientation programme when in Grade 8; length of enrolment in the school, and boarder status affected respondents' perceptions of certain aspects of orientation programmes.

  18. Ice haze, snow, and the Mars water cycle

    Science.gov (United States)

    Kahn, Ralph

    1990-01-01

    Light curves and extinction profiles derived from Martian limb observations are used to constrain the atmospheric temperature structure in regions of the atmosphere with thin haze and to analyze the haze particle properties and atmospheric eddy mixing. Temperature between 170 and 190 K are obtained for three cases at levels in the atmosphere ranging from 20 to 50 km. Eddy diffusion coefficients around 100,000 sq cm/s, typical of a nonconvecting atmosphere, are derived in the haze regions at times when the atmosphere is relatively clear of dust. This parameter apparently changes by more than three orders of magnitude with season and local conditions. The derived particle size parameter varies systematically by more than an order of magnitude with condensation level, in such a way that the characteristic fall time is always about one Martian day. Ice hazes provide a mechanism for scavenging water vapor in the thin Mars atmosphere and may play a key role in the seasonal cycle of water on Mars.

  19. Surface Haze and Surface Morphology of Blown Film Compositions

    OpenAIRE

    Patel, Rajen; Ratta, Varun; Saavedra, Pepe; Li, Jing

    2005-01-01

    Abstract Reduction in surface haze is a very attractive way to improve the optical properties of most polyolefin films. This route becomes very viable for coextruded multilayer films where the inner layers may be utilized to provide the desired mechanical properties, such as high modulus, controlled shrinkage, and good tear strength while the outer 'skin' layers are utilized to give low surface and ...

  20. Silver nanowire based flexible electrodes with improved properties: High conductivity, transparency, adhesion and low haze

    International Nuclear Information System (INIS)

    Graphical abstract: This graphical abstract illustrates the schematic representation of the main drawbacks and rectifications for AgNWs based transparent electrodes. - Highlights: • Films exhibited low sheet resistance and optical properties with Rs ≤ 30 Ω/□ and T ≥ 90%. • We decreased haze to 2% by controlling AgNWs length, diameter, and concentration. • We achieved good adhesion for AgNWs on PET film. • There is no significant change in resistance in the bending angle from 0° to 180°, and on twisting. - Abstract: Recent work has been focusing on solution processable transparent electrodes for various applications including solar cells and displays. As well as, the research aims majorly at silver nanowires (AgNWs) to replace ITO. We enhance the transparent electrode performance as a function of optical and mechanical properties with low sheet resistance, by controlling the AgNWs accept ratios, ink composition, and processing conditions. The nanowire network of transparent films agrees with the 2D percolation law. The film transmittance values at 550 nm are coping with a reference ITO film. Sheet resistance and haze values are suitable for flexible electronic applications. We fabricate transparent flexible film using a low-cost processing technique

  1. Low-haze, annealing-free, very long Ag nanowire synthesis and its application in a flexible transparent touch panel

    Science.gov (United States)

    Moon, Hyunjin; Won, Phillip; Lee, Jinhwan; Ko, Seung Hwan

    2016-07-01

    Since transparent conducting films based on silver nanowires (AgNWs) have shown higher transmittance and electrical conductivity compared to those of indium tin oxide (ITO) films, the electronics industry has recognized them as promising substitutes. However, due to the higher haze value of AgNW transparent conducting films compared to ITO films, the clarity is decreased when AgNW films are applied to optoelectronic devices. In this study, we develop a highly transparent, low-haze, very long AgNW percolation network. Moreover, we confirm that analyzed chemical roles can easily be applied to different AgNW synthesis methods, and that they have a direct impact on the nanowire shape. Consequently, the lengths of the wires are increased up to 200 μm and the diameters of the wires are decreased up to 45 nm. Using these results, we fabricate highly transparent (96%) conductors (100 Ω/sq) with low-haze (2%) without any annealing process. This electrode shows enhanced clarity compared to previous results due to the decreased diffusive transmittance and scattering. In addition, a flexible touchscreen using a AgNW network is demonstrated to show the performance of modified AgNWs.

  2. Impact of aerosol–meteorology interactions on fine particle pollution during China’s severe haze episode in January 2013

    International Nuclear Information System (INIS)

    In January 2013, a severe regional haze occurred over the North China Plain. An online-coupled meteorology-chemistry model was employed to simulate the impacts of aerosol–meteorology interactions on fine particles (PM2.5) pollution during this haze episode. The response of PM2.5 to meteorology change constituted a feedback loop whereby planetary boundary layer (PBL) dynamics amplified the initial perturbation of PM2.5. High PM2.5 concentrations caused a decrease of surface solar radiation. The maximal decrease in daily average solar radiation reached 53% in Beijing, thereby leading to a more stable PBL. The peak PBL height in Beijing decreased from 690 m to 590 m when the aerosol extinction was considered. Enhanced PBL stability suppressed the dispersion of air pollutants, and resulted in higher PM2.5 concentrations. The maximal increase of PM2.5 concentrations reached 140 μg m−3 in Beijing. During most PM2.5 episodes, primary and secondary particles increased simultaneously. These results imply that the aerosol–radiation interactions played an important role in the haze episode in January 2013. (letter)

  3. Low-haze, annealing-free, very long Ag nanowire synthesis and its application in a flexible transparent touch panel.

    Science.gov (United States)

    Moon, Hyunjin; Won, Phillip; Lee, Jinhwan; Ko, Seung Hwan

    2016-07-22

    Since transparent conducting films based on silver nanowires (AgNWs) have shown higher transmittance and electrical conductivity compared to those of indium tin oxide (ITO) films, the electronics industry has recognized them as promising substitutes. However, due to the higher haze value of AgNW transparent conducting films compared to ITO films, the clarity is decreased when AgNW films are applied to optoelectronic devices. In this study, we develop a highly transparent, low-haze, very long AgNW percolation network. Moreover, we confirm that analyzed chemical roles can easily be applied to different AgNW synthesis methods, and that they have a direct impact on the nanowire shape. Consequently, the lengths of the wires are increased up to 200 μm and the diameters of the wires are decreased up to 45 nm. Using these results, we fabricate highly transparent (96%) conductors (100 Ω/sq) with low-haze (2%) without any annealing process. This electrode shows enhanced clarity compared to previous results due to the decreased diffusive transmittance and scattering. In addition, a flexible touchscreen using a AgNW network is demonstrated to show the performance of modified AgNWs. PMID:27276174

  4. Invasive blue mussels threaten regional scale genetic diversity in mainland and remote offshore locations: the need for baseline data and enhanced protection in the Southern Ocean.

    Science.gov (United States)

    Gardner, Jonathan P A; Zbawicka, Małgorzata; Westfall, Kristen M; Wenne, Roman

    2016-09-01

    Human-mediated biological transfers of species have substantially modified many ecosystems with profound environmental and economic consequences. However, in many cases, invasion events are very hard to identify because of the absence of an appropriate baseline of information for receiving sites/regions. In this study, use of high-resolution genetic markers (single nucleotide polymorphisms - SNPs) highlights the threat of introduced Northern Hemisphere blue mussels (Mytilus galloprovincialis) at a regional scale to Southern Hemisphere lineages of blue mussels via hybridization and introgression. Analysis of a multispecies SNP dataset reveals hotspots of invasive Northern Hemisphere blue mussels in some mainland New Zealand locations, as well as the existence of unique native lineages of blue mussels on remote oceanic islands in the Southern Ocean that are now threatened by invasive mussels. Samples collected from an oil rig that has moved between South Africa, Australia, and New Zealand were identified as invasive Northern Hemisphere mussels, revealing the relative ease with which such non-native species may be moved from region to region. In combination, our results highlight the existence of unique lineages of mussels (and by extension, presumably of other taxa) on remote offshore islands in the Southern Ocean, the need for more baseline data to help identify bioinvasion events, the ongoing threat of hybridization and introgression posed by invasive species, and the need for greater protection of some of the world's last great remote areas. PMID:27124277

  5. Dispensability of the major coat protein of oat blue dwarf virus in genome replication: Substitution of the open reading frame with the enhanced green fluorescent protein gene

    Science.gov (United States)

    Oat blue dwarf virus (OBDV) is a representative marafivirus that infects monocots and a limited number of dicot species and is vectored propagatively by the leafhopper Macrosteles fascifrons.Recently, we reported the generation of clone pOBDV-2r, the first clone of a marafivirus from which infectiou...

  6. Diversity and Composition of Airborne Fungal Community Associated with Particulate Matters in Beijing during Haze and Non-haze Days

    Science.gov (United States)

    Yan, Dong; Zhang, Tao; Su, Jing; Zhao, Li-Li; Wang, Hao; Fang, Xiao-Mei; Zhang, Yu-Qin; Liu, Hong-Yu; Yu, Li-Yan

    2016-01-01

    To assess the diversity and composition of airborne fungi associated with particulate matters (PMs) in Beijing, China, a total of 81 PM samples were collected, which were derived from PM2.5, PM10 fractions, and total suspended particles during haze and non-haze days. The airborne fungal community in these samples was analyzed using the Illumina Miseq platform with fungi-specific primers targeting the internal transcribed spacer 1 region of the large subunit rRNA gene. A total of 797,040 reads belonging to 1633 operational taxonomic units were observed. Of these, 1102 belonged to Ascomycota, 502 to Basidiomycota, 24 to Zygomycota, and 5 to Chytridiomycota. The dominant orders were Pleosporales (29.39%), Capnodiales (27.96%), Eurotiales (10.64%), and Hypocreales (9.01%). The dominant genera were Cladosporium, Alternaria, Fusarium, Penicillium, Sporisorium, and Aspergilus. Analysis of similarities revealed that both particulate matter sizes (R = 0.175, p = 0.001) and air quality levels (R = 0.076, p = 0.006) significantly affected the airborne fungal community composition. The relative abundance of many fungal genera was found to significantly differ among various PM types and air quality levels. Alternaria and Epicoccum were more abundant in total suspended particles samples, Aspergillus in heavy-haze days and PM2.5 samples, and Malassezia in PM2.5 samples and heavy-haze days. Canonical correspondence analysis and permutation tests showed that temperature (p air pollution in Beijing. PMID:27148180

  7. Spatial and temporal variation of haze in China from 1961 to 2012.

    Science.gov (United States)

    Han, Rui; Wang, Shuxiao; Shen, Wenhai; Wang, Jiandong; Wu, Kang; Ren, Zhihua; Feng, Mingnong

    2016-08-01

    The purpose of this study is to analyze the climatic characteristics and long-term spatial and temporal variations of haze occurrence in China. The impact factors of haze trends are also discussed. Meteorological data from 1961 to 2012 and daily PM10 concentrations from 2003 to 2012 were employed in this study. The results indicate that the annual-average hazy days at all stations have been increasing rapidly from 4 days in 1961 to 18 days in 2012. The maximum number of haze days occur in winter (41.1%) while the minimum occur in summer (10.4%). During 1961-2012, the high occurrence areas of haze shifted from central to south and east regions of China. The Beijing-Tianjin-Hebei (Jing-Jin-Ji) region, Shanxi, Shaanxi, and Henan Province are the high occurrence areas for haze, while the Yangtze River Delta (YRD) and the Pearl River Delta (PRD) have become regions with high haze occurrences in the last 25 years. Temperature and pressure are positively correlated with the number of haze days. However, wind, relative humidity, precipitation, and sunshine duration are negatively correlated with the number of haze days. The key meteorological factors affecting the formation and dissipation of haze vary for high and low altitudes, and are closely related to anthropogenic activities. In recent years, anthropogenic activities have played a more important role in haze occurrences compared with meteorological factors. PMID:27521945

  8. Individual particle analysis of aerosols collected under haze and non-haze conditions at a high-elevation mountain site in the North China plain

    Science.gov (United States)

    Li, W. J.; Zhang, D. Z.; Shao, L. Y.; Zhou, S. Z.; Wang, W. X.

    2011-11-01

    The North China plain is a region with megacities and huge populations. Aerosols over the highly polluted area have a significant impact on the regional and global climate. In order to investigate the physical and chemical characteristics of aerosol particles in elevated layers there, observations were carried out at the summit of Mt. Tai (1534 m a.s.l.) from 19 to 28 April, 2010, when the air masses were advected from the east (phase-I: 19-21 April), from the south (phase-II: 22-25 April), and from the northwest (phase-III: 26-28 April). Individual aerosol particles were identified with transmission electron microscopy (TEM), new particle formation (NPF) and growth events were monitored by a wide-range particle spectrometer, and ion concentrations in PM2.5 were analyzed. During phase-I and phase-II, haze layers caused by anthropogenic pollution were observed, and a high percentage of particles were sulfur-rich (47-49%). In phase-III, the haze disappeared due to the intrusion of cold air from the northwest, and mineral dust particles from deserts were dominant (43%). NPF followed by particle growth during daytime was more pronounced on hazy than on clear days. Particle growth during daytime resulted in an increase of particle geometric mean diameter from 10-22 nm in the morning to 56-96 nm in the evening. TEM analysis suggests that sulfuric acid and secondary organic compounds should be important factors for particle nucleation and growth. However, the presence of fine anthropogenic particles (e.g., soot, metal, and fly ash) embedded within S-rich particles indicates that they could weaken NPF and enhance particle growth through condensation and coagulation. Abundant mineral particles in phase-III likely suppressed the NPF processes because they supplied sufficient area on which acidic gases or acids condensed.

  9. Blue cures blue but be cautious

    Directory of Open Access Journals (Sweden)

    Pranav Sikka

    2011-01-01

    Full Text Available Methemoglobinemia is a disorder characterized by the presence of >1% methemoglobin (metHb in the blood. Spontaneous formation of methemoglobin is normally counteracted by protective enzyme systems, for example, nicotinamide adenine dinucleotide phosphate (NADPH methemoglobin reductase. Methemoglobinemia is treated with supplemental oxygen and methylene blue (1-2 mg/kg administered slow intravenously, which acts by providing an artificial electron acceptor for NADPH methemoglobin reductase. But known or suspected glucose-6-phosphate dehydrogenase (G6PD deficiency is a relative contraindication to the use of methylene blue because G6PD is the key enzyme in the formation of NADPH through pentose phosphate pathway and G6PD-deficient individuals generate insufficient NADPH to efficiently reduce methylene blue to leukomethylene blue, which is necessary for the activation of the NADPH-dependent methemoglobin reductase system. So, we should be careful using methylene blue in methemoglobinemia patient before G6PD levels.

  10. Seasonal size distribution of airborne culturable bacteria and fungi and preliminary estimation of their deposition in human lungs during non-haze and haze days

    Science.gov (United States)

    Gao, Min; Jia, Ruizhi; Qiu, Tianlei; Han, Meilin; Song, Yuan; Wang, Xuming

    2015-10-01

    In recent years, haze events in Beijing have significantly increased in frequency. On haze days, airborne microorganisms are considered to be a potential risk factor for various health concerns. However, limited information on bioaerosols has prevented our proper understanding of the possible threat to human health due to these bioaerosols. In this study, we used a six-stage impactor for sampling culturable bioaerosols and the LUDEP 2.07 computer-based model for calculating their deposition on human lungs to investigate seasonal concentration, size distribution, and corresponding deposition efficiency and flux in the human respiratory tract during different haze-level events. The current results of the analysis of 398 samples over four seasons indicate that the concentration of culturable airborne bacteria decreased with increasing haze severity. The bioaerosol concentration ratio was skewed towards larger particle sizes on heavy haze days leading to larger bioaerosol aerodynamic diameters than on non-haze days. During nasal breathing by an adult male engaged in light exercise in an outdoor environment, the total deposition efficiency of culturable bioaerosols is 80-90% including approximately 70% in the upper respiratory tract, 5-7% in the alveoli, and about 3% in the bronchial couple with bronchiolar regions. Although the difference in culturable bioaerosol aerodynamic diameters at different haze levels was not large enough to cause obvious differences in lung deposition efficiency, the deposition fluxes clearly varied with the degree of haze owing to the varied concentration of culturable airborne bacteria and fungi. The results here could improve our understanding of the seasonal health threat due to culturable bioaerosols during non-haze and haze days.

  11. Significant concentration changes of chemical components of PM1 in the Yangtze River Delta area of China and the implications for the formation mechanism of heavy haze-fog pollution.

    Science.gov (United States)

    Zhang, Y W; Zhang, X Y; Zhang, Y M; Shen, X J; Sun, J Y; Ma, Q L; Yu, X M; Zhu, J L; Zhang, L; Che, H C

    2015-12-15

    Since the winter season of 2013, a number of persistent haze-fog events have occurred in central-eastern China. Continuous measurements of the chemical and physical properties of PM1 at a regional background station in the Yangtze River Delta area of China from 16 Nov. to 18 Dec., 2013 revealed several haze-fog events, among which a heavy haze-fog event occurred between 6 Dec. and 8 Dec. The mean concentration of PM1 was 212μgm(-3) in the heavy haze-fog period, which was about 10 times higher than on clean days and featured a peak mass concentration that reached 298μgm(-3). Organics were the largest contributor to the dramatic rise of PM1 on heavy haze-fog days (average mass concentration of 86μgm(-3)), followed by nitrate (58μgm(-3)), sulfate (35μgm(-3)), ammonium (29μgm(-3)), and chloride (4.0μgm(-3)). Nitrate exhibited the largest increase (~20 factors), associated with a significant increase in NOx. This was mainly attributable to increased coal combustion emissions, relative to motor vehicle emissions, and was caused by short-distance pollutant transport within surrounding areas. Low-volatility oxidized organic aerosols (OA) (LV-OOA) and biomass-burning OA (BBOA) also increased sharply on heavy haze-fog days, exhibiting an enhanced oxidation capacity of the atmosphere and increased emissions from biomass burning. The strengthening of the oxidation capacity during the heavy pollution episode, along with lower solar radiation, was probably due to increased biomass burning, which were important precursors of O3. The prevailing meteorological conditions, including low wind and high relative humidity, and short distance transported gaseous and particulate matter surrounding of the sampling site, coincided with the increased pollutant concentrations mainly from biomass-burning mentioned above to cause the persistent haze-fog event in the YRD area. PMID:26298245

  12. The Effect of CO on Planetary Haze Formation

    CERN Document Server

    Hörst, Sarah M

    2014-01-01

    Organic haze plays a key role in many planetary processes ranging from influencing the radiation budget of an atmosphere to serving as a source of prebiotic molecules on the surface. Numerous experiments have investigated the aerosols produced by exposing mixtures of N$_{2}$/CH$_{4}$ to a variety of energy sources. However, many N$_{2}$/CH$_{4}$ atmospheres in both our solar system and extrasolar planetary systems also contain CO. We have conducted a series of atmosphere simulation experiments to investigate the effect of CO on formation and particle size of planetary haze analogues for a range of CO mixing ratios using two different energy sources, spark discharge and UV. We find that CO strongly affects both number density and particle size of the aerosols produced in our experiments and indicates that CO may play an important, previously unexplored, role in aerosol chemistry in planetary atmospheres.

  13. The effect of carbon monoxide on planetary haze formation

    International Nuclear Information System (INIS)

    Organic haze plays a key role in many planetary processes ranging from influencing the radiation budget of an atmosphere to serving as a source of prebiotic molecules on the surface. Numerous experiments have investigated the aerosols produced by exposing mixtures of N2/CH4 to a variety of energy sources. However, many N2/CH4 atmospheres in both our solar system and extrasolar planetary systems also contain carbon monoxide (CO). We have conducted a series of atmosphere simulation experiments to investigate the effect of CO on the formation and particle size of planetary haze analogues for a range of CO mixing ratios using two different energy sources, spark discharge and UV. We find that CO strongly affects both number density and particle size of the aerosols produced in our experiments and indicates that CO may play an important, previously unexplored, role in aerosol chemistry in planetary atmospheres.

  14. The effect of carbon monoxide on planetary haze formation

    Energy Technology Data Exchange (ETDEWEB)

    Hörst, S. M.; Tolbert, M. A, E-mail: sarah.horst@colorado.edu [Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO (United States)

    2014-01-20

    Organic haze plays a key role in many planetary processes ranging from influencing the radiation budget of an atmosphere to serving as a source of prebiotic molecules on the surface. Numerous experiments have investigated the aerosols produced by exposing mixtures of N{sub 2}/CH{sub 4} to a variety of energy sources. However, many N{sub 2}/CH{sub 4} atmospheres in both our solar system and extrasolar planetary systems also contain carbon monoxide (CO). We have conducted a series of atmosphere simulation experiments to investigate the effect of CO on the formation and particle size of planetary haze analogues for a range of CO mixing ratios using two different energy sources, spark discharge and UV. We find that CO strongly affects both number density and particle size of the aerosols produced in our experiments and indicates that CO may play an important, previously unexplored, role in aerosol chemistry in planetary atmospheres.

  15. Impact of relative humidity on visibility degradation during a haze event: A case study.

    Science.gov (United States)

    Deng, Hua; Tan, Haobo; Li, Fei; Cai, Mingfu; Chan, P W; Xu, Hanbing; Huang, Xiaoying; Wu, Dui

    2016-11-01

    Light scattering of aerosols depends on ambient relative humidity (RH) since hygroscopic particles absorb significant water at high RH, and this results in low visibility. This paper used custom-made parallel nephelometers (PNEPs) to measure aerosol light scattering enhancement factor ƒ(RH), and utilized data including visibility, PM2.5, black carbon, water-soluble ions mass concentrations and surface meteorological parameters, in conjunction with background weather conditions, to analyze a haze event in Guangzhou during 8th-15th Dec. 2013. Unfavorable weather conditions, such as high RH and low wind speed, were observed during the haze event. The hourly average mass concentration of PM2.5 was 127μg/m(3), with concentration of 192.4μg/m(3) on 9th and 196μg/m(3) on 13th. The ƒ(RH) did not exhibit significant changes during this haze process, with value of ƒ(80%)=1.58±0.07. Although the mass fraction of water-soluble ions to PM2.5 decreased after 12th Dec., the aerosol hygroscopicity might not have changed significantly since the mass fraction of nitrate became more dominant, which has stronger ability to take up water. The best-fitted parameterized function for ƒ(RH) is ƒ(RH)=0.731+0.1375∗(1-RH/100)(-1)+0.00719∗(1-RH/100)(-2). Combining the fixed parameterization of ƒ(RH) above, the visibility was calculated with the measured light scattering and absorption coefficient of particles and gas under dry condition, as well as ambient RH. The predicted visibility range agrees well with the measurements without precipitation. Using ISORROPIA II model, the calculated aerosol liquid water content (ALWC) at ambient RH varied consistently with the PM2.5 under lower RH, while it was more influenced by high RH. This work also show that high RH accompanied with precipitation will enhance aerosol hygroscopic growth effect, leading to further visibility degradation, even if PM2.5 mass decreased due to precipitation. PMID:27395081

  16. Investigating the impact of haze on MODIS cloud detection

    Science.gov (United States)

    Mao, Feiyue; Duan, Miaomiao; Min, Qilong; Gong, Wei; Pan, Zengxin; Liu, Guangyi

    2015-12-01

    The cloud detection algorithm for passive sensors is usually based on a fuzzy logic system with thresholds determined from previous observations. In recent years, haze and high aerosol concentrations with high aerosol optical depth (AOD) occur frequently in China and may critically impact the accuracy of the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud detection. Thus, we comprehensively explore this impact by comparing the results from MODIS/Aqua (passive sensor), Cloud-Aerosol Lidar with Orthogonal Polarization/CALIPSO (lidar sensor), and Cloud Profiling Radar/CloudSat (microwave sensor) of the A-Train suite of instruments using an averaged AOD as an index for an aerosol concentration value. Case studies concerning the comparison of the three sensors indicate that MODIS cloud detection is reduced during haze events. In addition, statistical studies show that an increase in AOD creates an increase in the percentage of uncertain flags and a decrease in hit rate, a consistency index between consecutive sets of cloud retrievals. On average, AOD values lower than 0.1 give hit rate values up to 80.0% and uncertainty values lower than 16.8%, while AOD values greater than 1.0 reduce the hit rate below to 66.6% and increase the percentage of uncertain flags up to 46.6%. Therefore, we can conclude that the ability of MODIS cloud detection is weakened by large concentrations of aerosols. This suggests that use of the MODIS cloud mask, and derived higher-level products, in situations with haze requires caution. Further improvement of this retrieval algorithm is desired as haze studies based on MODIS products are of great interest in a number of related fields.

  17. Single Image Haze Removal Method for Inland River

    Directory of Open Access Journals (Sweden)

    Qiu Liu

    2013-01-01

    Full Text Available Due to environmental pollution, the climate is worsening. The fog days up to 60% of the year in inland certain segments, which it has seriously affected the marine electronic cruise normal operation and navigation safety. According to the inland video image becomes gray and lack of visibility in foggy weather conditions, and in order to remove the haze to get a clear image color and contour, this paper presents a method based on Jones Extension Matrix and the Dark Channel Prior. First, we obtain the light intensity in the atmosphere and the estimated concentration of the haze by using Dark Channel Prior, and via using the Jones Extension Matrix and the parameters of Stokes' Law to eliminate part of the scattered light. At last, we have completed the function of image dehazing by brightness adjustment factor based on N pixels in the field of step brightness and improve the brightness based on Retinex Principle for the recovered image. Experimental results show this algorithm improves scenery visual effect in condition of haze. It is provided a clear video image for the marine electronic cruise in the foggy day.

  18. Photolytic Hazes in the Atmosphere of 51 Eri b

    CERN Document Server

    Zahnle, Kevin J; Morley, Caroline V; Moses, Julianne I

    2016-01-01

    We use a 1D model to address photochemistry and possible haze formation in the irradiated warm Jupiter, 51 Eridani b. The intended focus was to be carbon, but sulfur photochemistry turns out to be important. The case for organic photochemical hazes is intriguing but falls short of being compelling. If organic hazes form, they are likeliest to do so if vertical mixing in 51 Eri b is weaker than in Jupiter, and they would be found below the altitudes where methane and water are photolyzed. The more novel result is that photochemistry turns H$_2$S into elemental sulfur, here treated as S$_8$. In the cooler models, S$_8$ is predicted to condense in optically thick clouds of solid sulfur particles, whilst in the warmer models S$_8$ remains a vapor along with several other sulfur allotropes that are both visually striking and potentially observable. For 51 Eri b, the division between models with and without condensed sulfur is at an effective temperature of 700 K, which is within error its actual effective temperat...

  19. SEASONAL DISAPPEARANCE OF FAR-INFRARED HAZE IN TITAN'S STRATOSPHERE

    International Nuclear Information System (INIS)

    A far-infrared emission band attributed to volatile or refractory haze in Titan's stratosphere has been decreasing in intensity since Cassini's arrival in 2004. The 220 cm–1 feature, first seen by the Voyager Infrared Interferometer Spectrometer, has only been found in Titan's winter polar region. The emission peaks at about 140 km altitude near the winter stratospheric temperature minimum. Observations recorded over the period 2004-2012 by the Composite Infrared Spectrometer on Cassini show a decrease in the intensity of this feature by about a factor of four. Possible seasonal causes of this decline are an increase in photolytic destruction of source chemicals at high altitude, a lessening of condensation as solar heating increased, or a weakening of downwelling of vapors. As of early 2012, the 220 cm–1 haze has not yet been detected in the south. The haze composition is unknown, but its decrease is similar to that of HC3N gas in Titan's polar stratosphere, pointing to a nitrile origin.

  20. Photon-avalanche upconversion of Ho{sup 3+} in NaYF{sub 4} and enhancement of violet, blue and green emissions induced by sensitization of Tm{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Huabing; Bu Yanyan [Institute for Nanophysics and Rare-earth Luminescence, Xiangtan University, Xiangtan 411105, Hunan (China); Yang Xiaoliang, E-mail: xiaoliangy@xtu.edu.cn [Institute for Nanophysics and Rare-earth Luminescence, Xiangtan University, Xiangtan 411105, Hunan (China); Xiao Siguo; Ding, J.W. [Institute for Nanophysics and Rare-earth Luminescence, Xiangtan University, Xiangtan 411105, Hunan (China)

    2011-02-25

    Ho{sup 3+} singly doped and Ho{sup 3+}/Tm{sup 3+} co-doped hexagonal NaYF{sub 4} powders have been synthesized by a solid-state reaction method. Under excitation of 671 nm diode laser, upconverted blue, green and red emission bands are observed in Ho{sup 3+} singly doped sample. Temporal evolution and excitation power dependent behavior for the green emission are explored, indicating that a photon-avalanche mechanism is responsible for the upconversion processes in Ho{sup 3+} singly doped hexagonal NaYF{sub 4} sample. With the introduction of Tm{sup 3+}, the intensities of both blue and green emissions of Ho{sup 3+} are efficiently enhanced, which are attributed to two energy transfer processes from Tm{sup 3+} to Ho{sup 3+}, i.e., {sup 3}F{sub 4} (Tm{sup 3+}) + {sup 5}I{sub 8}(Ho{sup 3+}) {yields} {sup 3}H{sub 6} (Tm{sup 3+}) + {sup 5}I{sub 7}(Ho{sup 3+}) and {sup 1}G{sub 4} (Tm{sup 3+}) + {sup 5}I{sub 8}(Ho{sup 3+}) {yields} {sup 3}H{sub 6} (Tm{sup 3+}) + {sup 5}F{sub 3}(Ho{sup 3+}). The result offers a new sensitization approach to enhance the upconversion efficiency of Ho{sup 3+} under 671 nm excitation.

  1. Overexpression of the Synthetic Chimeric Native-T-phylloplanin-GFP Genes Optimized for Monocot and Dicot Plants Renders Enhanced Resistance to Blue Mold Disease in Tobacco (N. tabacum L.

    Directory of Open Access Journals (Sweden)

    Dipak K. Sahoo

    2014-01-01

    Full Text Available To enhance the natural plant resistance and to evaluate the antimicrobial properties of phylloplanin against blue mold, we have expressed a synthetic chimeric native-phylloplanin-GFP protein fusion in transgenic Nicotiana tabacum cv. KY14, a cultivar that is highly susceptible to infection by Peronospora tabacina. The coding sequence of the tobacco phylloplanin gene along with its native signal peptide was fused with GFP at the carboxy terminus. The synthetic chimeric gene (native-phylloplanin-GFP was placed between the modified Mirabilis mosaic virus full-length transcript promoter with duplicated enhancer domains and the terminator sequence from the rbcSE9 gene. The chimeric gene, expressed in transgenic tobacco, was stably inherited in successive plant generations as shown by molecular characterization, GFP quantification, and confocal fluorescent microscopy. Transgenic plants were morphologically similar to wild-type plants and showed no deleterious effects due to transgene expression. Blue mold-sensitivity assays of tobacco lines were performed by applying P. tabacina sporangia to the upper leaf surface. Transgenic lines expressing the fused synthetic native-phyllopanin-GFP gene in the leaf apoplast showed resistance to infection. Our results demonstrate that in vivo expression of a synthetic fused native-phylloplanin-GFP gene in plants can potentially achieve natural protection against microbial plant pathogens, including P. tabacina in tobacco.

  2. Overexpression of the synthetic chimeric native-T-phylloplanin-GFP genes optimized for monocot and dicot plants renders enhanced resistance to blue mold disease in tobacco (N. tabacum L.).

    Science.gov (United States)

    Sahoo, Dipak K; Raha, Sumita; Hall, James T; Maiti, Indu B

    2014-01-01

    To enhance the natural plant resistance and to evaluate the antimicrobial properties of phylloplanin against blue mold, we have expressed a synthetic chimeric native-phylloplanin-GFP protein fusion in transgenic Nicotiana tabacum cv. KY14, a cultivar that is highly susceptible to infection by Peronospora tabacina. The coding sequence of the tobacco phylloplanin gene along with its native signal peptide was fused with GFP at the carboxy terminus. The synthetic chimeric gene (native-phylloplanin-GFP) was placed between the modified Mirabilis mosaic virus full-length transcript promoter with duplicated enhancer domains and the terminator sequence from the rbcSE9 gene. The chimeric gene, expressed in transgenic tobacco, was stably inherited in successive plant generations as shown by molecular characterization, GFP quantification, and confocal fluorescent microscopy. Transgenic plants were morphologically similar to wild-type plants and showed no deleterious effects due to transgene expression. Blue mold-sensitivity assays of tobacco lines were performed by applying P. tabacina sporangia to the upper leaf surface. Transgenic lines expressing the fused synthetic native-phyllopanin-GFP gene in the leaf apoplast showed resistance to infection. Our results demonstrate that in vivo expression of a synthetic fused native-phylloplanin-GFP gene in plants can potentially achieve natural protection against microbial plant pathogens, including P. tabacina in tobacco. PMID:24778589

  3. Relationship between haze and acute cardiovascular, cerebrovascular, and respiratory diseases in Beijing.

    Science.gov (United States)

    Zhang, Jin-Jun; Cui, Meng-Meng; Fan, Da; Zhang, De-Shan; Lian, Hui-Xin; Yin, Zhao-Yin; Li, Jin

    2015-03-01

    Haze is an atmospheric phenomenon in which dry particulate pollutants obscure the sky. Haze has been associated with chronic diseases, but its relationship with acute diseases is less clear. We aimed to determine the association between haze and acute cardiovascular, cerebrovascular, and respiratory diseases, in order to determine the influence of haze on human health. We compared the number of cases of acute cardiovascular, cerebrovascular, and respiratory diseases in Beijing Emergency Center between 2006 and 2013, with haze data from Beijing Observatory. The relationship between the number of hazy days and the number of cases of the above types of diseases was analyzed using univariate analyses. Both the number of cases and the number of hazy days showed a rising trend. The average number of cases per day for all three diseases was higher on hazy days than on non-hazy days. There was a positive correlation between the number of hazy days and the number of cases, and this correlation showed a hysteretic quality. Haze has an influence on acute cardiovascular (CVDs), cerebrovascular (CBDs), and respiratory system (RSDs) diseases. Haze seems to have an additive effect, since the associations between haze and number of cases were stronger in the following month than in the preceding month. The increasing trend in the number of hazy days might worsen the problem of haze-related diseases. PMID:25292298

  4. Satellite observation of regional haze pollution over the North China Plain

    Science.gov (United States)

    Tao, Minghui; Chen, Liangfu; Su, Lin; Tao, Jinhua

    2012-06-01

    Haze clouds often form over the North China Plain (NCP) of eastern China, where large amounts of aerosol particles and their precursors are emitted. To obtain general insights into regional pollution, a large-scale, long-term study was conducted using A-Train satellite observations, ground measurements, and meteorological data. Contrary to previous analyses, most of the haze clouds appeared to form abruptly (within 2-3 h). Case studies show that natural sources contribute significantly to the formation of regional haze. Dust plumes can mix with local pollutants, causing smog clouds to form abruptly, while moist airflows can cause widespread haze-fog pollution. The combined observations revealed highly inhomogeneous haze clouds, in terms of both vertical and horizontal distribution, leading to clear discrepancies between site measurements near the surface and satellite observations at the top of the atmosphere. Surprisingly, prevailing dust plumes, which are closely connected with the haze clouds, were observed in winter. Airborne dust and water vapor transported from outside the region are the main drivers of regional haze over the NCP. Accumulation of local pollutants also leads to common occurrences of urban smog; however, the occurrence of most haze clouds shows no obvious correlation with local pollution. Local- and regional-scale haze pollution are common over the NCP, but they have differing formation mechanisms, and contrasting chemical and physical properties. The present findings improve our understanding of heavy pollution over eastern China and its links to climate.

  5. The impact of haze on the adolescent's acute respiratory disease:A single institution study

    Institute of Scientific and Technical Information of China (English)

    Wan Fairos Wan Yaacob; Nor Suhana Mohamad Noor; Nor Ili Che A Bakar; Nurulhuda Afisah Mat Zin; Fahisham Taib

    2016-01-01

    Objective: To examine the impact of haze in the reduction of peak expiratory flow rate (PEFR) reading and identify the risk factors affecting respiratory function due to haze. Methods: This study was conducted during haze period among secondary school stu-dents in Kota Bharu. We analyzed data on a total of 126 secondary school children measuring the respiratory health and symptoms in October 2015 using standardized questionnaire and PEFR measurement. Clinical characteristics on the risk factor and prevalence of haze effect were explored. Chi-square test and independent sample t-test was used to investigate the relationship between risk factors and haze effect and logistic regression analysis for the odds of having haze effect. Results: The findings revealed a significant reduction in PEFR reading of more than 15%from the expected PEFR values. It was also noted that the children with headache, cough, mucus and sore throat respiratory symptoms had consistently higher rates of respiratory illness of having haze effect compared to those who did not. Conclusions: Student with haze effect documented much higher symptoms during haze especially female students. Symptoms such as headache, wheezing and mucus were noted among the normal secondary school children in Kota Bharu.

  6. Characterization and optimization of hydrogen production by a salt water blue-green alga Oscillatoria sp. Miami BG 7. II - Use of immobilization for enhancement of hydrogen production

    Science.gov (United States)

    Phlips, E. J.; Mitsui, A.

    1986-01-01

    The technique of cellular immobilization was applied to the process of hydrogen photoproduction of nonheterocystous, filamentous marine blue-green alga, Oscillatoria sp. Miami BG 7. Immobilization with agar significantly improved the rate and longevity of hydrogen production, compared to free cell suspensions. Rates of H2 production in excess of 13 microliters H2 mg dry/wt h were observed and hydrogen production was sustained for three weeks. Immobilization also provided some stabilization to environmental variability and was adaptable to outdoor light conditions. In general, immobilization provides significant advantages for the production and maintenance of hydrogen photoproduction for this strain.

  7. The Impact of Clouds and Hazes in Substellar Atmospheres

    Science.gov (United States)

    Morley, Caroline; Fortney, Jonathan J.; Marley, Mark S.

    2016-01-01

    The formation of clouds significantly alters the spectra of cool substellar atmospheres from terrestrial planets to brown dwarfs. In cool planets like Earth and Jupiter, volatile species like water and ammonia condense to form ice clouds. In hot planets and brown dwarfs, iron and silicates instead condense, forming dusty clouds. Irradiated methane-rich planets may have substantial hydrocarbon hazes. During my thesis, I have studied the impact of clouds and hazes in a variety of substellar objects. First, I present results for cool brown dwarfs including clouds previously neglected in model atmospheres. Model spectra that include sulfide and salt clouds can match the spectra of T dwarf atmospheres; water ice clouds will alter the spectra of the newest and coldest brown dwarfs, the Y dwarfs. These sulfide/salt and ice clouds potentially drive spectroscopic variability in these cool objects, and this variability should be distinguishable from variability caused by hot spots.Next, I present results for small, cool exoplanets between the size of Earth and Neptune, so-called super Earths. They likely have sulfide and salt clouds and also have photochemical hazes caused by stellar irradiation. Vast resources have been dedicated to characterizing the handful of super Earths accessible to current telescopes, yet of the planets smaller than Neptune studied to date, all have radii in the near-infrared consistent with being constant in wavelength, likely showing that these small planets are consistently enshrouded in thick hazes and clouds. Very thick, lofted clouds of salts or sulfides in high metallicity (1000× solar) atmospheres create featureless transmission spectra in the near-infrared. Photochemical hazes with a range of particle sizes also create featureless transmission spectra at lower metallicities. I show that despite these challenges, there are promising avenues for understanding this class of small planets: by observing the thermal emission and reflectivity of

  8. Blue organic light-emitting diodes with low driving voltage and maximum enhanced power efficiency based on buffer layer MoO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Khizar-ul-Haq, E-mail: khizar_bhr@yahoo.co [School of Materials Science and Engineering, Shanghai University, Jiading Shanghai 201800 (China); Khan, M.A.; Jiang, X.Y. [School of Materials Science and Engineering, Shanghai University, Jiading Shanghai 201800 (China); Zhang, Z.L. [School of Materials Science and Engineering, Shanghai University, Jiading Shanghai 201800 (China)] [Key Laboratories of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072 (China); Zhang, X.W. [School of Materials Science and Engineering, Shanghai University, Jiading Shanghai 201800 (China); Wei, Bin [School of Materials Science and Engineering, Shanghai University, Jiading Shanghai 201800 (China)] [Key Laboratories of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072 (China); Wei, J.M.; Zhang Liang; Li Jun [School of Materials Science and Engineering, Shanghai University, Jiading Shanghai 201800 (China)

    2009-10-15

    Blue organic light-emitting devices based on wide bandgap host material, 2-(t-butyl)-9, 10-di-(2-naphthyl) anthracene (TBADN), blue fluorescent styrylamine dopant, p-bis(p-N,N-diphenyl-amino-styryl)benzene (DSA-Ph) have been realized by using molybdenum oxide (MoO{sub 3}) as a buffer layer and 4,7-diphenyl-1,10-phenanthroline (BPhen) as the ETL. The typical device structure used was glass substrate/ITO/MoO{sub 3} (5 nm)/NPB (30 nm)/[TBADN: DSA-Ph (3 wt%)](35 nm)/BPhen (12 nm)/LiF (0.8 nm)/Al (100 nm). It was found that the MoO{sub 3}-parallel BPhen-based device shows the lowest driving voltage and highest power efficiency among the referenced devices. At the current density of 20 mA/cm{sup 2}, its driving voltage and power efficiency are 5.4 V and 4.7 Lm/W, respectively, which is independently reduced 46%, and improved 74% compared with those the m-MTDATA-parallel Alq{sub 3} is based on, respectively. The J-V curves of 'hole-only' devices reveal that a small hole injection barrier between MoO{sub 3}-parallel NPB leads to a strong hole injection, resulting low driving voltage and high power efficiency. The results strongly indicate that carrier injection ability and balance shows a key significance in OLED performance.

  9. Typical Types and Formation Mechanisms of Haze in an Eastern Asia Megacity, Shanghai

    Science.gov (United States)

    Huang, K.; Zhuang, G.; Lin, Y.; Fu, J. S.; Wang, Q.; Liu, T.; Zhang, R.; Jiang, Y.; Deng, C.; Fu, Q.; Hsu, N. C.; Cao, B.

    2012-01-01

    An intensive aerosol and gases campaign was performed at Shanghai in the Yangtze River Delta region over Eastern China from late March to early June 2009. This study provided a complementary picture of typical haze types and the formation mechanisms in megacities over China by using a synergy of ground-based monitoring, satellite and lidar observations. During the whole study period, several extreme low visibility periods were observed with distinct characteristics, and three typical haze types were identified, i.e. secondary inorganic pollution, dust, and biomass burning. Sulfate, nitrate and ammonium accounted for a major part of PM2.5 mass during the secondary inorganic pollution, and the good correlation between SO2/NOx/CO and PM2.5 indicated that coal burning and vehicle emission were the major sources. Large-scale regions with high AOD (aerosol optical depths) and low Angstrom exponent were detected by remote-sensing observation during the dust pollution episode, and this episode corresponded to coarse particles rich in mineral components such as Al and Ca contributing 76.8% to TSP. The relatively low Ca/Al ratio of 0.75 along with the air mass backward trajectory analysis suggested the dust source was from Gobi Desert. Typical tracers for biomass burning from satellite observation (column CO and HCHO) and from ground measurement (CO, particulate K+, OC, and EC) were greatly enhanced during the biomass burning pollution episode. The exclusive linear correlation between CO and PM2.5 corroborated that organic aerosol dominated aerosol chemistry during biomass burning, and the high concentration and enrichment degree of arsenic (As) could be also partly derived from biomass burning. Aerosol optical profile observed by lidar demonstrated that aerosol was mainly constrained below the boundary layer and comprised of spheric aerosol (depolarization ratio <5%) during the secondary inorganic and biomass burning episodes, while thick dust layer distributed at altitudes

  10. What have we learned from HaChi (HAZE IN CHINA) project?

    Science.gov (United States)

    Zhao, Chunsheng; Wiedensohler, Alfred

    2016-04-01

    HaChi (Haze in China) project, a joint research between Chinese NSFC and German DFG, focuses on investigating the aerosol hygroscopic properties in the North China Plain and their relationships to aerosol optics, radiation, cloud physics and ozone photochemistry. As we know, Eastern China has suffered from severe pollution caused by large concentrations of aerosol particles resulting from emissions from fossil fuel and biomass burning, transportation and some other combustion sources. Low visibility events are frequently encountered and mainly accompanied with haze as a result of either high aerosol loading or the strong hygroscopic growth of the aerosol particles. Especially at relative humidities between 90 and 99%, the aerosol particles grow exponentially. The hygroscopic behaviors at relative humidities close to 100% are also strongly linked to the particles ability to grow into cloud droplets at supersaturation. In my talk, I will present an overview of the up to date results from a serial of intensive and comprehensive field campaigns conducted at the sites of Wuqing and Xianghe, China, between 2009 and 2014. The measurements of the ambient aerosol hygroscopic properties at high RH between 90 and 98.5% are reported first. These in situ field measurements of atmospheric aerosol are unique with respect to their high RH range and especially of importance to better understand the widespread anthropogenic haze over the North China Plain. Then I will introduce the methods for calculating of aerosol hygroscopicity and their parameterization schemes derived from size-segregated chemical composition and the light scattering enhancement factor measurements in the North China Plain. A new method was proposed to retrieve the ratio of the externally mixed light absorbing carbon mass to the total mass of light absorbing carbon. A new parameterization scheme of light extinction for low visibilities on hazy days is proposed based on visibility, relative humidity, aerosol

  11. Typical types and formation mechanisms of haze in an eastern Asia megacity, Shanghai

    Directory of Open Access Journals (Sweden)

    K. Huang

    2011-08-01

    Full Text Available An intensive aerosol and gases campaign has been performed at Shanghai in the Yangtze River Delta region over Eastern China from late March to early June 2009. This study provided a complementary picture of typical haze types and formation mechanisms in megacities over China by using a synergy of ground-based monitoring, satellite observation and lidar inversion. During the whole study period, several extreme low visibility periods were observed with distinct characteristics, and three typical haze types were identified, i.e. secondary inorganic pollution, dust, and biomass burning. Sulfate, nitrate and ammonium accounted for a major part of PM2.5 mass during the secondary inorganic pollution, and the good correlation between SO2/NOx/CO and PM2.5 indicated that coal burning and vehicle emission were the major sources. Large-scale regions with high AOD and low Ångström exponent were detected by remote-sensing observation during the dust pollution episode, and this episode corresponded to coarse particles rich in mineral components such as Al and Ca with mineral aerosol contributing 76.8 % to TSP. The relatively low Ca/Al ratio of 0.75 combined with the air mass backward trajectory analysis suggested the dust source from Gobi Desert. Typical tracers for biomass burning from satellite observation (column CO and HCHO and from ground measurement (CO, particulate K+, OC, and EC were greatly enhanced during the biomass burning pollution episode. The exclusive linear correlation between CO and PM2.5 corroborated that organic aerosol dominated aerosol chemistry during biomass burning, and the high concentration and enrichment degree of arsenic (As could be also partly derived from biomass burning. Aerosol optical profile observed by lidar demonstrated that aerosol was mainly constrained below the boundary layer and comprised of spheric aerosol (depolarization ratio <5 % during the

  12. Typical types and formation mechanisms of haze in an Eastern Asia megacity, Shanghai

    Directory of Open Access Journals (Sweden)

    K. Huang

    2012-01-01

    Full Text Available An intensive aerosol and gases campaign was performed at Shanghai in the Yangtze River Delta region over Eastern China from late March to early June 2009. This study provided a complementary picture of typical haze types and the formation mechanisms in megacities over China by using a synergy of ground-based monitoring, satellite and lidar observations. During the whole study period, several extreme low visibility periods were observed with distinct characteristics, and three typical haze types were identified, i.e. secondary inorganic pollution, dust, and biomass burning. Sulfate, nitrate and ammonium accounted for a major part of PM2.5 mass during the secondary inorganic pollution, and the good correlation between SO2/NOx/CO and PM2.5 indicated that coal burning and vehicle emission were the major sources. Large-scale regions with high AOD (aerosol optical depths and low Ångström exponent were detected by remote-sensing observation during the dust pollution episode, and this episode corresponded to coarse particles rich in mineral components such as Al and Ca contributing 76.8% to TSP. The relatively low Ca/Al ratio of 0.75 along with the air mass backward trajectory analysis suggested the dust source was from Gobi Desert. Typical tracers for biomass burning from satellite observation (column CO and HCHO and from ground measurement (CO, particulate K+, OC, and EC were greatly enhanced during the biomass burning pollution episode. The exclusive linear correlation between CO and PM2.5 corroborated that organic aerosol dominated aerosol chemistry during biomass burning, and the high concentration and enrichment degree of arsenic (As could be also partly derived from biomass burning. Aerosol optical profile observed by lidar demonstrated that aerosol was mainly constrained below the boundary layer and comprised of spheric aerosol (depolarization ratio <5% during the secondary

  13. Impact of crop field burning and mountains on heavy haze in the North China Plain: a case study

    Science.gov (United States)

    Long, Xin; Tie, Xuexi; Cao, Junji; Huang, Rujin; Feng, Tian; Li, Nan; Zhao, Suyu; Tian, Jie; Li, Guohui; Zhang, Qiang

    2016-08-01

    With the provincial statistical data and crop field burning (CFB) activities captured by Moderate Resolution Imaging Spectroradiometer (MODIS), we extracted a detailed CFB emission inventory in the North China Plain (NCP). The WRF-CHEM model was applied to investigate the impact of CFB on air pollution during the period from 6 to 12 October 2014, corresponding to a heavy haze incident with high concentrations of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm). The WRF-CHEM model generally performed well in simulating the surface species concentrations of PM2.5, O3 and NO2 compared to the observations; in addition, it reasonably reproduced the observed temporal variations of wind speed, wind direction and planetary boundary layer height (PBLH). It was found that the CFB that occurred in southern NCP (SNCP) had a significant effect on PM2.5 concentrations locally, causing a maximum of 34 % PM2.5 increase. Under continuous southerly wind conditions, the CFB pollution plume went through a long-range transport to northern NCP (NNCP; with several mega cities, including Beijing, the capital city of China), where few CFBs occurred, resulting in a maximum of 32 % PM2.5 increase. As a result, the heavy haze in Beijing was enhanced by the CFB, which occurred in SNCP. Mountains also play significant roles in enhancing the PM2.5 pollution in NNCP through the blocking effect. The mountains blocked and redirected the airflows, causing the pollutant accumulations along the foothills of mountains. This study suggests that the prohibition of CFB should be strict not only in or around Beijing, but also on the ulterior crop growth areas of SNCP. PM2.5 emissions in SNCP should be significantly limited in order to reduce the occurrences of heavy haze events in the NNCP region.

  14. Characteristics of bacterial and fungal aerosols during the autumn haze days in Xi'an, China

    Science.gov (United States)

    Li, Yanpeng; Fu, Honglei; Wang, Wei; Liu, Jun; Meng, Qinglong; Wang, Wenke

    2015-12-01

    In recent years, haze pollution has become one of the most critical environmental issues in Xi'an, China, with particular matter (PM) being one of the top pollutants. As an important fraction of PM, bioaerosols may have adverse effects on air quality and human health. In this study, to better understand the characteristics of such biological aerosols, airborne microbial samples were collected by using an Andersen six-stage sampler in Xi'an from October 8th to 22nd, 2014. The concentration, size distribution and genera of airborne viable bacteria and fungi were comparably investigated during the haze days and non-haze days. Correlations of bioaerosol levels with meteorological parameters and PM concentrations were also examined. The results showed that the daily average concentrations of airborne viable bacteria and fungi during the haze days, 1102.4-1736.5 and 1466.2-1703.9 CFU/m3, respectively, were not only much higher than those during the non-haze days, but also exceeded the recommended permissible limit values. Comparing to size distributions during the non-haze days, slightly different patterns for bacterial aerosols and similar single-peak distribution pattern for fungal aerosols were observed during the haze days. Moreover, more allergic and infectious genera (e.g. Neisseria, Aspergillus, and Paecilomyces) in bioaerosols were identified during the haze days than during non-haze days. The present results reveal that bioaerosols may have more significant effects on public health and urban air quality during the haze days than during non-haze days.

  15. 77 FR 75703 - Partial Approval and Disapproval of Air Quality Implementation Plans; Arizona; Regional Haze and...

    Science.gov (United States)

    2012-12-21

    ... against the sky. \\6\\ 64 FR 35715 (July 1, 1999). B. History of Regional Haze Regulations In section 169A... measures sufficient to meet the interstate transport visibility requirement. \\4\\ 77 FR 72512. III. Regional... states' SIPs designed to address regional haze.'' 72 FR 41629 at 41632. \\20\\ 77 FR 66398 (November...

  16. 77 FR 11894 - Approval and Promulgation of Air Quality Implementation Plans; South Carolina; Regional Haze...

    Science.gov (United States)

    2012-02-28

    ... haze requirements. See 76 FR 82219 (December 30, 2011). EPA is not proposing to take action in today's... haze on July 1, 1999 (64 FR 35713), the RHR. The RHR revised the existing visibility regulations to... approved into the South Carolina SIP. See 50 FR 28544 (July 12, 1985) and 52 FR 45132 (November 24,...

  17. Planck Intermediate Results. IX. Detection of the Galactic haze with Planck

    DEFF Research Database (Denmark)

    Planck Collaboration,; Ade, P. A. R.; Aghanim, N.;

    2013-01-01

    Using precise full-sky observations from Planck, and applying several methods of component separation, we identify and characterize the emission from the Galactic "haze" at microwave wavelengths. The haze is a distinct component of diffuse Galactic emission, roughly centered on the Galactic centre...

  18. 77 FR 66929 - Approval and Promulgation of Implementation Plans; State of Idaho; Regional Haze State...

    Science.gov (United States)

    2012-11-08

    ... a previous action EPA approved certain provisions in Idaho's Regional Haze SIP submission, 76 FR...]. regional haze SIP elements as proposed in the May 22, 2012 notice. 77 FR 30248. 0 3. Section 52.672 is... toward improving visibility in mandatory Class I Federal areas \\1\\ (Class I areas). 64 FR 35714 (July...

  19. 77 FR 30467 - Approval and Promulgation of Implementation Plans; State of Washington; Regional Haze State...

    Science.gov (United States)

    2012-05-23

    ... regional haze on July 1, 1999 (64 FR 35713) (the Regional Haze Rule or RHR). The RHR revised the existing... toward improving visibility in mandatory Class I Federal areas \\1\\ (Class I areas). 64 FR 35714 (July 1, 1999); see also 70 FR 39104 (July 6, 2005) and 71 FR 60612 (October 13, 2006). \\1\\ Areas designated...

  20. 77 FR 11798 - Approval and Promulgation of Air Quality Implementation Plans; Rhode Island; Regional Haze

    Science.gov (United States)

    2012-02-28

    ... (64 FR 35714), the Regional Haze Rule. The Regional Haze Rule revised the existing visibility... conditions. See 64 FR 35715, (July 1, 1999). B. Background Information In section 169A(a)(1) of the 1977... FR 80084 (Dec. 2, 1980). These regulations represented the first phase in addressing...

  1. 77 FR 17334 - Approval and Promulgation of Air Quality Implementation Plans; State of Nevada; Regional Haze...

    Science.gov (United States)

    2012-03-26

    ... promulgated a rule to address regional haze on July 1, 1999 known as the Regional Haze Rule (RHR). See 64 FR... program. EPA proposed to approve all parts of Nevada's SIP revisions on June 22, 2011 (76 FR 36450). This... conditions. 64 FR 35715 (July 1, 1999). \\1\\ Visual range is the greatest distance, in kilometers or miles,...

  2. 76 FR 27973 - Approval and Promulgation of Air Quality Implementation Plans; State of Delaware; Regional Haze...

    Science.gov (United States)

    2011-05-13

    .... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional Haze Rule... kilometers or about one-fifth of the visual range that would exist under estimated natural conditions (64 FR... of sources, i.e., ``reasonably attributable visibility impairment'' (45 FR 80084). These...

  3. 77 FR 11809 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Regional Haze

    Science.gov (United States)

    2012-02-28

    .... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional Haze Rule... FR 35715, (July 1, 1999). B. Background Information In section 169A(a)(1) of the 1977 Amendments to... of sources, i.e., ``reasonably attributable visibility impairment'' (RAVI). See 45 FR 80084, (Dec....

  4. 77 FR 11914 - Approval and Promulgation of Air Quality Implementation Plans; Vermont; Regional Haze

    Science.gov (United States)

    2012-02-28

    .... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional Haze Rule... the visual range that would exist under estimated natural conditions. See 64 FR 35715, (July 1, 1999....e., ``reasonably attributable visibility impairment'' (RAVI). See 45 FR 80084 (Dec. 2,1980)....

  5. 76 FR 43963 - Regional Haze State Implementation Plan; State of Nevada; Extension of Comment Period

    Science.gov (United States)

    2011-07-22

    ... plan. DATES: The comment period for the proposed rule published June 22, 2011 (76 FR 36450), is... AGENCY 40 CFR Part 51 Regional Haze State Implementation Plan; State of Nevada; Extension of Comment... (SIP) to implement the regional haze program for the first planning period through July 31, 2018....

  6. 77 FR 11022 - Approval and Promulgation of Implementation Plans; State of Alaska; Regional Haze State...

    Science.gov (United States)

    2012-02-24

    ... address regional haze on July 1, 1999 (64 FR 35713), the regional haze rule or RHR. The RHR revised the... Federal areas \\1\\ (Class I areas). 64 FR 35714 (July 1, 1999); see also 70 FR 39104 (July 6, 2005) and 71 FR 60612 (October 13, 2006). \\1\\ Areas designated as mandatory Class I Federal areas consist...

  7. 77 FR 76871 - Approval and Promulgation of Implementation Plans; State of Colorado; Regional Haze State...

    Science.gov (United States)

    2012-12-31

    ... haze in 1999 (64 FR 35714, July 1, 1999, codified at 40 CFR part 51, subpart P). The requirements for... the regional haze requirements (74 FR 2392). Once EPA has found that a state has failed to make a... Register on March 26, 2012 (77 FR 18052). In that notice, we provided a detailed description of the...

  8. 77 FR 50611 - Approval and Promulgation of Implementation Plans; State of Oregon; Regional Haze State...

    Science.gov (United States)

    2012-08-22

    ... approved certain provisions in Oregon's Regional Haze SIP submission. 76 FR 38997. This previous action... developing a LTS. 76 FR 38997. A detailed explanation of the Regional Haze Rule including the requirements... retrofit technology (BART). 76 FR 38997. On May 23, 2012, EPA proposed approving the remaining portion...

  9. 76 FR 73955 - Approval and Promulgation of Air Quality Implementation Plans; Maine; Regional Haze

    Science.gov (United States)

    2011-11-29

    ..., 1999)). EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the Regional... significance to be assigned to each factor. (70 FR 39170, (July 6, 2005)). A regional haze SIP must include... FR 35715, (July 1, 1999)) B. Background Information In section 169A(a)(1) of the 1977 Amendments...

  10. 77 FR 41279 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Regional Haze State...

    Science.gov (United States)

    2012-07-13

    ... CAA and EPA's Regional Haze Rule (64 FR 35714, July 1, 1999) and the rationale for EPA's proposed... under the Regional Haze Rule at Appendix Y to 40 CFR part 51 (hereafter the BART Rule). See 70 FR 39104... (NPR) for Pennsylvania (77 FR 3984). The NPR proposed limited approval of Pennsylvania's RH SIP....

  11. 78 FR 49684 - Approval and Disapproval of Air Quality State Implementation Plans; Arizona; Regional Haze and...

    Science.gov (United States)

    2013-08-15

    ... INFORMATION: In Federal Register document 2013-18022 published in the Federal Register on July 30, 2013 (78 FR...; Regional Haze and Interstate Transport Requirements AGENCY: Environmental Protection Agency (EPA). ACTION... of Arizona's State Implementation Plan (SIP) to implement the regional haze program for the...

  12. 77 FR 22550 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Regional Haze...

    Science.gov (United States)

    2012-04-16

    ..., 2012 (77 FR 11809) is reopened. Comments must be received on or before April 27, 2012. ADDRESSES...; Regional Haze; Reopening of Comment Period AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed... 26, 2011, that addresses regional haze for the first planning period from 2008 through 2018....

  13. 77 FR 39938 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Regional Haze State...

    Science.gov (United States)

    2012-07-06

    ... approving into the Maryland SIP. \\1\\ EPA promulgated the RHR to address regional haze on July 1, 1999 (64 FR... which the SIP relies,'' which is ``defined as 2002 for regional haze purposes.'' See 64 FR 35742, July 1..., 2012 (77 FR 11839), EPA published a notice of proposed rulemaking (NPR) for the State of Maryland....

  14. 76 FR 52604 - Approval and Promulgation of Implementation Plans; State of Kansas Regional Haze State...

    Science.gov (United States)

    2011-08-23

    ... address Regional Haze issues. EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713... about one-fifth of the visual range that would exist under estimated natural conditions. See 64 FR 35715....e. ``reasonably attributable visibility impairment'' (45 FR 80084). These regulations...

  15. 77 FR 19098 - Approval and Promulgation of Implementation Plans; Commonwealth of Kentucky; Regional Haze State...

    Science.gov (United States)

    2012-03-30

    ..., 1999 (64 FR 35713), the Regional Haze Rule (RHR). The RHR revised the existing visibility regulations... for regional haze. See 76 FR 78194. EPA proposed a limited approval of Kentucky's two SIP revisions to....e., ``reasonably attributable visibility impairment.'' See 45 FR 80084. These...

  16. 77 FR 39177 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Regional Haze

    Science.gov (United States)

    2012-07-02

    ..., 2012 (77 FR 3712). The proposal notice described the nature of the regional haze problem and the... December 30, 2011 (76 FR 82219), EPA did in fact propose a limited disapproval of the Ohio regional haze... codified at 40 CFR 51.308. This rule was promulgated on July 1, 1999 (64 FR 35713). Further...

  17. 77 FR 30248 - Approval and Promulgation of Implementation Plans; State of Idaho; Regional Haze State...

    Science.gov (United States)

    2012-05-22

    ... regional haze on July 1, 1999 (64 FR 35713) (the regional haze rule or RHR). The RHR revised the existing... toward improving visibility in mandatory Class ] I Federal areas \\1\\ (Class I areas). 64 FR 35714 (July 1, 1999); see also 70 FR 39104 (July 6, 2005) and 71 FR 60612 (October 13, 2006). \\1\\ Areas designated...

  18. 77 FR 20893 - Approval and Promulgation of Implementation Plans; North Dakota; Regional Haze State...

    Science.gov (United States)

    2012-04-06

    ... regional haze issues, and we promulgated regulations addressing regional haze in 1999. 64 FR 35714 (July 1... requirements. 74 FR 2392. Once EPA has found that a state has failed to make a required submission, EPA is.... 62 FR 38652. Section 110(a)(2) of the CAA lists the elements that such new SIPs must address,...

  19. Transboundary smoke haze pollution in Malaysia: Inpatient health impacts and economic valuation

    International Nuclear Information System (INIS)

    This study assessed the economic value of health impacts of transboundary smoke haze pollution in Kuala Lumpur and adjacent areas in the state of Selangor, Malaysia. Daily inpatient data from 2005, 2006, 2008, and 2009 for 14 haze-related illnesses were collected from four hospitals. On average, there were 19 hazy days each year during which the air pollution levels were within the Lower Moderate to Hazardous categories. No seasonal variation in inpatient cases was observed. A smoke haze occurrence was associated with an increase in inpatient cases by 2.4 per 10,000 populations each year, representing an increase of 31 percent from normal days. The average annual economic loss due to the inpatient health impact of haze was valued at MYR273,000 ($91,000 USD). - Highlights: • Transboundary smoke haze is an annual phenomenon in Malaysia. • No evidence of seasonal factors in smoke haze related inpatient cases. • Inpatient rates during a haze event increased by 31% relative to normal days. • Annual economic loss due to inpatient health impact of haze valued at $91,000. • Present value of economic loss estimated at $1.1 million to $1.7 million. - Inpatient rates soared by 31% while economic loss valued at USD91,000 annually

  20. 76 FR 1579 - Approval and Promulgation of Implementation Plans; State of Idaho; Regional Haze State...

    Science.gov (United States)

    2011-01-11

    ... light. Fine particulate can also cause serious health effects and mortality in humans, and contributes... rule to address regional haze on July 1, 1999 (64 FR 35713) (the RHR). The RHR revised the existing.... Regional haze SIPs were required to be submitted by December 17, 2007. See 74 FR 2392. At this later...

  1. 78 FR 18280 - Approval and Promulgation of Air Quality Implementation Plans; Nevada; Regional Haze Federal...

    Science.gov (United States)

    2013-03-26

    ... appropriate, disproportionately high and adverse human health or environmental effects of their programs.... See, for example, EPA's proposed approval of the Nevada Regional Haze SIP on June 22, 2011 (76 FR..., Health, and Safety at NV Energy to Anita Lee, US EPA Region 9, re: Nevada Regional Haze...

  2. 77 FR 11958 - Approval and Promulgation of Air Quality Implementation Plans; State of Missouri; Regional Haze...

    Science.gov (United States)

    2012-02-28

    ... 2.5 can also cause serious health effects and mortality in humans and contributes to environmental... regional haze requirements. 76 FR 82219. We are not proposing to take action in today's rulemaking on.... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713), the RHR. The...

  3. 77 FR 11839 - Approval and Promulgation of Implementation Plans; Louisiana; Regional Haze State Implementation...

    Science.gov (United States)

    2012-02-28

    ... distance that one can see. PM 2.5 can also cause serious health effects and mortality in humans and... would BART. 76 FR 82219. Based on this proposed finding, EPA also proposed to revise the Regional Haze... haze SIP may be found at Docket ID No. EPA-HQ-OAR-2011-0729. \\2\\ 76 FR 48208 (August 8,...

  4. 76 FR 12651 - Approval and Promulgation of Implementation Plans; State of Oregon; Regional Haze State...

    Science.gov (United States)

    2011-03-08

    ... health effects and mortality in humans, and contributes to environmental effects such as acid deposition... address regional haze on July 1, 1999 (64 FR 35713) (the RHR). The RHR revised the existing visibility.... Regional haze SIPs were required to be submitted by December 17, 2007. See 74 FR 2392. At this later...

  5. 76 FR 82219 - Regional Haze: Revisions to Provisions Governing Alternatives to Source-Specific Best Available...

    Science.gov (United States)

    2011-12-30

    ... distance at which one can see a scene. PM 2.5 can also cause serious health effects and mortality in humans... promulgated the RHR to address regional haze on July 1, 1999 (64 FR 35713). The RHR revised the existing... haze program made in 2005. 70 FR 39104 (July 6, 2005). In those revisions, we amended our...

  6. Male Team Sport Hazing Initiations in a Culture of Decreasing Homohysteria

    Science.gov (United States)

    Anderson, Eric; McCormack, Mark; Lee, Harry

    2012-01-01

    In this longitudinal ethnographic research, we report on 7 years of hazing rituals on two separate men's sports teams at one university in the United Kingdom. Using 38 in-depth interviews alongside naturalistic observations of the initiation rituals, we demonstrate that hazing activities have changed from being centered around homophobic same-sex…

  7. Prevalence and Profiling: Hazing Among College Students and Points of Intervention

    Science.gov (United States)

    Campo, Shelly; Poulos, Gretchen; Sipple, John W.

    2005-01-01

    Objective : To examine university students' attitudes, behaviors, and beliefs related to hazing. Methods : A random and representative sample of students completed a web-based survey regarding team-building and initiation behaviors (N=736). Results : Thirty-six percent of the respondents participated in hazing. Greeks, males, varsity athletes,…

  8. 76 FR 44534 - Approval and Promulgation of Air Quality Implementation Plans; Tennessee; Regional Haze State...

    Science.gov (United States)

    2011-07-26

    .... The Commenters requested the extension in order to determine any potential impacts of the CSAPR on the... potential impacts of the final CSAPR on EPA's proposed rulemaking to approve Tennessee's Regional Haze State... the Regional Haze requirements and, specifically, any potential impacts on the Tennessee Regional...

  9. Photolytic Hazes in the Atmosphere of 51 Eri b

    Science.gov (United States)

    Zahnle, K.; Marley, M. S.; Morley, C. V.; Moses, J. I.

    2016-06-01

    We use a 1D model to address photochemistry and possible haze formation in the irradiated warm Jupiter, 51 Eridani b. The intended focus was to be carbon, but sulfur photochemistry turns out to be important. The case for organic photochemical hazes is intriguing but falls short of being compelling. If organic hazes form, they are likeliest to do so if vertical mixing in 51 Eri b is weaker than in Jupiter, and they would be found below the altitudes where methane and water are photolyzed. The more novel result is that photochemistry turns H2S into elemental sulfur, here treated as S8. In the cooler models, S8 is predicted to condense in optically thick clouds of solid sulfur particles, while in the warmer models S8 remains a vapor along with several other sulfur allotropes that are both visually striking and potentially observable. For 51 Eri b, the division between models with and without condensed sulfur is at an effective temperature of 700 K, which is within error its actual effective temperature; the local temperature where sulfur condenses is between 280 and 320 K. The sulfur photochemistry we have discussed is quite general and ought to be found in a wide variety of worlds over a broad temperature range, both colder and hotter than the 650–750 K range studied here, and we show that products of sulfur photochemistry will be nearly as abundant on planets where the UV irradiation is orders of magnitude weaker than it is on 51 Eri b.

  10. Feeling blue? Blue phosphors for OLEDs

    Directory of Open Access Journals (Sweden)

    Hungshin Fu

    2011-10-01

    Full Text Available Research on organic light emitting diodes (OLEDs has been revitalized, partly due to the debut of the OLED TV by SONY in 2008. While there is still plenty of room for improvement in efficiency, cost-effectiveness and longevity, it is timely to report on the advances of light emitting materials, the core of OLEDs, and their future perspectives. The focus of this account is primarily to chronicle the blue phosphors developed in our laboratory. Special attention is paid to the design strategy, synthetic novelty, and their OLED performance. The report also underscores the importance of the interplay between chemistry and photophysics en route to true-blue phosphors.

  11. Enhanced orange-red emission from KSrVO4:Sm3+ nanophosphor for possible application in blue light-emitting diode based white LED

    International Nuclear Information System (INIS)

    In this paper, the combustion synthesis and photoluminescence properties of Sm3+ doped KSrVO4 nanophosphors are reported. The samples were characterized by different techniques such as x-ray powder diffraction, transmission electron microscopy, UV–vis spectrophotometry and photoluminescence spectroscopy. The lattice parameters were calculated as a=7.4688 (4) A-ring ´, b=5.8171 (4) A-ring ´, c=9.9490 (5) A-ring ´ and V=432.2485 (5) Ǻ3. The average grain size of the samples was estimated as 42 nm using the modified Scherrer’s equation. Under near UV excitation, the sharp emission line at 560, 600, 646 and 704 nm due to characteristic transitions of Sm3+ were observed. The maximum PL emission intensity was observed at 1.5 mol.% of the Sm3+ ions. The band gap of the phosphor was calculated from diffused reflectance data and was found to be 3.74 eV. The CIE 1931 chromaticity coordinates (x, y) of the phosphor were (0.61, 0.39), in a shade of orange-red color. The potential applications of this material as a down conversion phosphor under blue light excitation were evaluated for possible application as a high color-purity phosphor in light emitting diodes (LEDs) that can fill the 590–600 nm gap. (paper)

  12. Blue-green algae

    Science.gov (United States)

    ... Lac Klamath, Anabaena, Aphanizomenon flos-aquae, Arthrospira maxima, Arthrospira platensis, BGA, Blue Green Algae, Blue-Green Micro-Algae, Cyanobacteria, Cyanobactérie, Cyanophycée, Dihe, Espirulina, Hawaiian Spirulina, Klamath, Klamath Lake Algae, Lyngbya wollei, Microcystis aeruginosa, ...

  13. Blue-green algae

    Science.gov (United States)

    ... unresponsive to other treatments, taking 500 mg of spirulina blue-green algae by mouth 3 times daily for 6 months ... was seen in undernourished children who were given spirulina blue-green algae with a combination of millet, soy and peanut ...

  14. Templated blue phases.

    Science.gov (United States)

    Ravnik, Miha; Fukuda, Jun-ichi

    2015-11-21

    Cholesteric blue phases of a chiral liquid crystal are interesting examples of self-organised three-dimensional nanostructures formed by soft matter. Recently it was demonstrated that a polymer matrix introduced by photopolymerization inside a bulk blue phase not only stabilises the host blue phase significantly, but also serves as a template for blue phase ordering. We show with numerical modelling that the transfer of the orientational order of the blue phase to the surfaces of the polymer matrix, together with the resulting surface anchoring, can account for the templating behaviour of the polymer matrix inducing the blue phase ordering of an achiral nematic liquid crystal. Furthermore, tailoring the anchoring conditions of the polymer matrix surfaces can bring about orientational ordering different from those of bulk blue phases, including an intertwined complex of the polymer matrix and topological line defects of orientational order. Optical Kerr response of templated blue phases is explored, finding large Kerr constants in the range of K = 2-10 × 10(-9) m V(-2) and notable dependence on the surface anchoring strength. More generally, the presented numerical approach is aimed to clarify the role and actions of templating polymer matrices in complex chiral nematic fluids, and further to help design novel template-based materials from chiral liquid crystals. PMID:26412643

  15. Vertically-aligned sandwich nanowires enhance the photoelectrochemical reduction of hydrogen peroxide: hierarchical formation on carbon nanotubes of cadmium sulfide quantum dots and Prussian blue nanocoatings.

    Science.gov (United States)

    Gong, Kuanping

    2015-07-01

    We describe a vertically-aligned array of sandwiched nanowires comprising Prussian blue (PB) nanocoating-carbon nanotube (CNT) core-shell structures with CdS particles positioning at the core/shell interface, viz. PB/CdS/CNT. The PB/CdS/CNT electrode thus constructed are noticeable in synchronically harvesting photon-, ionic-, and chemical-energies, respectively, from visible light radiation, K(+) uptaking and releasing, and the reduction of H2O2. In 0.2 M K2SO4 aqueous solution, the photoelectrocatalytic reduction of 1.5 mM H2O2 at PB/CdS/CNT delivered the current density as high as 1.91 mA/cm(2) at reduced overpotential, that is, three times that at the Pt/C. This superb performance is causally linked to the judicious choice of materials and their assembly into defining sandwich nanostructures wherein the three components closely cooperate with each other in the photoelectrocatalytic reduction of H2O2, including photo-induced charge separation in CdS, spontaneous electron injection into PB due to its relatively low Fermi level, and the electrocatalytic reduction of H2O2 by PB via an electrochemical-chemical-electrochemical reaction mechanism. The structural alignment of PB/CdS/CNT ensures the simplest pathway for the mass diffusion and electron shuttle, and a high surface area accessible to the chemical and electrochemical reactions, so as to minimize the concentration- and electrochemical-polarization and thus ensure the fast overall kinetics of the electrode reaction. PMID:25458868

  16. Societal-Equity-Enhancing Criteria and Facility-Host Incentives Supporting Five Key Elements in the January 2012 Blue Ribbon Commission Report - 13015

    International Nuclear Information System (INIS)

    In February 2009, the Obama Administration announced it would abandon USA's only candidate SNF/HLW-disposal facility since 1987. In 2010, all related activities were stopped and the Blue Ribbon Commission on America's Nuclear Future was established 'to recommend a new strategy for managing the back end of the nuclear fuel cycle', which it did in January 2012, emphasizing eight key elements. However, Key Element 1, 'A new, consent-based approach to siting future nuclear facilities', is qualitative/indeterminate rather than quantitative/measurable. It is thus highly-susceptible to semantic permutations that could extend rather than, as intended, expedite the siting of future nuclear facilities unless it also defines: a) Whose consent is needed?; and b) What constitutes consent? The following 'generic', radiation-risk- and societal-equity-based criteria address these questions: 1. Identify areas affected by projected radiation and other health risks from: a. The proposed nuclear facility (facility stakeholders); and b. The related nuclear-materials-transportation routes (transportation stakeholders); then 2. Surround each stakeholder area with a buffer zone and use this enlarged foot print to identify: a. Stakeholder hosts; and b. Areas not hosting any stakeholder category (interested parties). 3. Define 'consent-based' as being at least 60 percent of the 'population' in the respective stakeholder category and apply this yardstick to both 'in favor' and 'against' votes. Although criteria 1 and 2 also need facility-based definitions to make Key Element 1 measurable, the described siting approach, augmented by related facility-host incentives, would expedite the schedule and reduce the cost for achieving Key Elements 4-6 and 8, politics permitting. (authors)

  17. Enhanced adsorptive and photocatalytic achievements in removal of methylene blue by incorporating tungstophosphoric acid-TiO2 into MCM-41

    International Nuclear Information System (INIS)

    The use of titania-dispersed materials in photocatalytic processes has been proposed as an alternative to the conventional bare TiO2, in order to modify the surface area and activity of the catalyst. A homogeneously dispersed Keggin unit into TiO2 was synthesized using tungstophosphoric acid (TPA) and titanium tetraisopropoxide. This compound was then loaded into MCM-41 by dispersing it in a suspension containing the mesoporous phase. Two other titanium-containing MCM-41 catalysts, Ti-MCM-41 and TiO2/MCM-41 were also prepared using isomorphous substitution synthesis method and impregnation method, respectively, for the sake of comparison. The prepared photocatalysts were characterized by X-ray diffraction (XRD), nitrogen physisorption (BET) and chemical analysis. The catalysts were used to study degradation of methylene blue (MB) in aqueous solution. XRD result shows a pure anatase crystalline phase for TPA-containing TiO2 indicating that there is good molecular distribution of tungstophosphoric acid into TiO2 structure. Supported TPA-TiO2 into MCM-41 shows both TPA-TiO2 and MCM-41 characteristic X-ray reflections in the high-angle and low-angle parts of the XRD patterns, respectively. The experimental results show that adsorption is a major constituent in the elimination of MB from the dye solutions by the TPA-containing materials. Exploitation of both adsorption and photocatalytic processes speeds up the removal of the dye using the TPA-TiO2-loaded MCM-41 photocatalyst. The elimination of MB is completed within 15 min for a 30 mg l-1 MB solution containing a catalyst dose of 100 mg/100 ml. The efficiencies of the other photocatalysts such as commercial TiO2, Ti-MCM-41, TiO2/MCM-41 and TPA-TiO2 for adsorption and degradation of MB were also studied and compared with that of the prepared catalyst.

  18. Proteome-Based Analysis of Colloidal Instability Enables the Detection of Haze-Active Proteins in Beer.

    Science.gov (United States)

    Schulte, Fabian; Flaschel, Erwin; Niehaus, Karsten

    2016-09-01

    Colloidal haze is a serious quality defect of bright beers that considerably reduces their shelf life and is thought to be triggered by hordeins, a class of proline-rich barley proteins. In this work, the proteomes of fresh and old beers were investigated in bottled pilsners and compared to the protein inventory of haze to identify specific haze-active proteins. Haze isolates dissolved in rehydration buffer contained high concentrations of proteins and sugars but provided protein gels with weak spot signals. Consequently, a treatment for the chemical deglycation with trifluoromethanesulfonic acid was applied, which resulted in the identification of protein Z4, LTP1, CMb, CMe, pUP13, 3a, and Bwiph as constituents of the haze proteome. Because only one hordein was detectable and the proline content in haze hydrolysates was lower than those of barley prolamins, our results suggest that this class of proteins is of minor importance for haze development. PMID:27515584

  19. Characteristics of atmospheric particulate mercury in size-fractionated particles during haze days in Shanghai

    Science.gov (United States)

    Chen, Xiaojia; Balasubramanian, Rajasekhar; Zhu, Qiongyu; Behera, Sailesh N.; Bo, Dandan; Huang, Xian; Xie, Haiyun; Cheng, Jinping

    2016-04-01

    Atmospheric particulate mercury (PHg) is recognized as a global pollutant that requires regulation because of its significant impacts on both human health and wildlife. The haze episodes that occur frequently in China could influence the transport and fate of PHg. To examine the characteristics of PHg during haze and non-haze days, size-fractioned particles were collected using thirteen-stage Nano-MOUDI samplers (10 nm-18 μm) during a severe haze episode (from December 2013 to January 2014) in Shanghai. The PHg concentration on haze days (4.11 ± 0.53 ng m-3) was three times higher than on non-haze days (1.34 ± 0.15 ng m-3). The ratio of the PHg concentration to total gaseous mercury (TGM) ranged from 0.42 during haze days to 0.21 during non-haze days, which was possibly due to the elevated concentration of particles for gaseous elemental mercury (GEM) adsorption, elevated sulfate and nitrate contributing to GEM oxidation, and the catalytic effect of elevated water-soluble inorganic metal ions. PHg/PM10 during haze days (0.019 ± 0.004 ng/μg) was lower than during non-haze days (0.024 ± 0.002 ng/μg), and PHg/PM10 was significantly reduced with an increasing concentration of PM10, which implied a relatively lower growth velocity of mercury than other compositions on particles during haze days, especially in the diameter range of 0.018-0.032 μm. During haze days, each size-fractioned PHg concentration was higher than the corresponding fraction on non-haze days, and the dominant particle size was in the accumulation mode, with constant accumulation to a particle size of 0.56-1.0 μm. The mass size distribution of PHg was bimodal with peaks at 0.32-0.56 μm and 3.1-6.2 μm on non-haze days, and 0.56-1.0 μm and 3.1-6.2 μm on haze days. There was a clear trend that the dominant size for PHg in the fine modes shifted from 0.32-0.56 μm during non-haze days to 0.56-1.0 μm on haze days, which revealed the higher growth velocity of PHg on haze days due to the

  20. Haze in Southeast Asia: Needed Local Actions for a Regional Problem

    Science.gov (United States)

    Odihi, J. O.

    - Southeast Asia experienced disastrous haze episodes in 1997 and 1998 as a result of natural factors such as the El-Niño occurrence and its attendant drought, which aided desiccation and facilitated high combustibility of forest resources, and human activities such as widespread burning of forests in the lush tropical environment. The human factors that caused the haze are presented in this paper, and the conclusion is that Nature is not guilty. A comprehensive approach that tackles the root causes of the haze problem is suggested. Particularly, socioeconomic problems of the poor who use fire as part of their land management, promulgation and effective enforcement of environmental laws are needed on the one hand to reduce the frequency and magnitude of haze episodes in the future. On the other hand, education of the public on `safe' behavior during haze episodes is necessary to avert large scale haze-related disasters or to prevent haze from becoming instantly synonymous with disaster in the region.

  1. Analysis of a severe prolonged regional haze episode in the Yangtze River Delta, China

    Science.gov (United States)

    Wang, Mengya; Cao, Chunxiang; Li, Guoshuai; Singh, Ramesh P.

    2015-02-01

    A severe prolonged regional haze episode occurred over the Yangtze River Delta (YRD) from 2 to 14 December 2013. In this paper, we have discussed the probable cause of haze episode and aerosol characteristics. Analysis of visibility and meteorological parameters suggest that the meteorological conditions play a very important role in the accumulation of aerosol particles that cause haze. The height of the planetary boundary layer (PBL) is considered as one of the key factors together with other factors in the haze formation. The Principal Component Analysis (PCA) clearly shows accumulation process of air pollutants from vehicular, industrial and anthropogenic sources are major contributors for the haze formation. The aerosol optical properties (aerosol optical depth - AOD, Ångström exponent - α and Ultra Violet Aerosol Index - UVAI) are analyzed to study the temporal and spatial variations of aerosol loadings. The results show concentrations of fine mode particles during the haze episode, the dust could have been also entered in the region from the northwestern China. Analysis of vertical aerosol profiles indicate that dust aerosols concentrated in the lower part of the haze layers.

  2. Blue ocean strategy.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2004-10-01

    Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades. PMID:15559577

  3. Ambient bioaerosol particle dynamics observed during haze and sunny days in Beijing.

    Science.gov (United States)

    Wei, Kai; Zou, Zhuanglei; Zheng, Yunhao; Li, Jing; Shen, Fangxia; Wu, Chang-Yu; Wu, Yusheng; Hu, Min; Yao, Maosheng

    2016-04-15

    The chemical characteristics of airborne particulate matter (PM) have been extensively studied; however, little information exists for its biological components (bioaerosol) especially during a haze event in mega cities. Herein, we studied the bioaerosol (fluorescent particle) dynamics on both haze and sunny days in Beijing from Dec. 2013 to March 2014 by employing a widely used real-time bioaerosol sensor-ultraviolet aerodynamic particle spectrometer (UV-APS). Firstly, we studied the fluorescent particle (BioPM) concentration and size distributions during three independent haze and three independent sunny days. Secondly, we investigated BioPM dynamics over a two-week long monitoring period which included consecutive haze days and alternated sunny days. In addition, we analyzed bacterial community structures and endotoxin levels in the air samples using pyrosequencing and Limulus amebocyte lysate (LAL) method, respectively. More than 6-fold higher fluorescent particle concentrations up to 5×10(5)/m(3) with peaks at night or early dawn were detected at the time of haze occurrences than those observed on sunny days. When the haze episode progressed for 3-5days, the BioPM concentrations were observed to decrease to the levels that were typically observed on sunny days. In general, ozone levels were found to be elevated at noon, while BioPM, NOx and relative humidity were reduced. Gene sequence analysis revealed no significant difference in abundances and community structures for top 13 bacterial genera between haze and sunny days, yet about twice higher endotoxin levels (12.4EU/m(3)) were detected on haze days than on sunny days. The results here facilitate a better understanding of atmospheric fluorescent particle dynamics including those under haze events. PMID:26849339

  4. Chemical characteristics of PM2.5 during a typical haze episode in Guangzhou

    Institute of Scientific and Technical Information of China (English)

    TAN Jihua; DUAN Jingchun; HE Kebin; MA Yuanliang; DUAN Fengkui; CHEN Yuan; FU Jiamo

    2009-01-01

    The chemical characteristics (water-soluble ions and carbonaceous species) of PM2.5 in Guangzhou were measured during a typical haze episode.Most of the chemical species in PM2.5 showed significant difference between normal and haze days.The highest contributors to PM2.5 were organic carbon (OC),nitrate,and sulfate in haze days and were OC,sulfate,and elemental carbon (EC) in normal days.The concentrations of secondary species such as,NO3-,SO42-,and NH4+ in haze days were 6.5,3.9 and 5.3 times higher than those in normal days,respectively,while primary species (EC,Ca2+,K+) show similar increase from normal to haze days by a factor about 2.2-2.4.OC/EC ratio ranged from 2.8 to 6.2 with an average of 4.7 and the estimation on a minimum OC/EC ratio showed that SOC (secondary organic carbon) accounted more than 36.6% for the total organic carbon in haze days.The significantly increase in the secondary species (SOC,NO3-,SO42-,and NH4+),especially in NO3-,caused the worst air quality in this region.Simultaneously,the result illustrated that the serious air pollution in haze episodes was strongly correlated with the meteorological conditions.During the sampling periods,air pollution and visibility have a good relationship with the air mass transport distance;the shorter air masses transport distance,the worse air quality and visibility in Guangzhou,indicating the strong domination of local sources contributing to haze formation.High concentration of the secondary aerosol in haze episodes was likely due to the higher oxidation rates of sulfur and nitrogen species.

  5. [Aerosol Optical Properties in the Northern Suburb of Nanjing During Haze Days in January 2013].

    Science.gov (United States)

    Wang, Li-peng; Ma, Yan; Zheng, Jun; Cui, Fen-ping; Zhou, Yao-yao

    2016-03-15

    In January 2013 large-scale, continuous and severe haze occurred in Nanjing. Three-wavelength photoacoustic soot spectrometer (PASS-3) was used for real-time, online and situ measurements of aerosol absorption and scattering coefficients in the northern suburb of Nanjing during January 2013. The results indicated that the average aerosol absorption and scattering coefficients were (83.20 ± 35.24) Mm⁻¹ and (670.16 ± 136.44) Mm⁻¹ during haze days, which were 3.85 and 3.45 times higher than those on clean days, respectively. The diurnal variation of absorption and scattering coefficients showed a bimodal distribution. The mean single scattering albedo and scattering Angstrom exponent were (0.89 ± 0.04) and (1.30 ± 0.27) respectively, indicating the predominance of scattering fine particles during haze days in Nanjing. Aerosols could be significantly removed by precipitation. The absorption and scattering coefficients showed negative correlations with surface wind speed, and the single scattering albedo and Angstrom exponent showed positive correlations with wind speed. Aerosol scattering coefficient was highest under southeasterly wind, whereas the absorption coefficient was highest under the southwesterly wind. In the three haze pollution events, Haze 1 and Haze 2 were mainly affected by long-range transportation of pollutants. Haze 1 was mainly affected by aging air mass from north Nanjing, Haze 2 was mainly affected by biomass burning air mass from southwest Nanjing, while Haze 3 was mainly caused by the high sulfate. PMID:27337871

  6. Transport characteristics of Chinese haze over Northern Taiwan in winter, 2005-2014

    Science.gov (United States)

    Wang, Sheng-Hsiang; Hung, Wei-Ting; Chang, Shuenn-Chin; Yen, Ming-Cheng

    2016-02-01

    Haze over east China has been extensively studied, but its impacts on downwind areas remain unclear. In this study, we applied long-term (9 yr) air quality, meteorological, and ground-based remote sensing data for investigating the transported haze events over Northern Taiwan in winter. Thirty-six haze events were identified using a statistical method and information pertaining to wind direction and episode duration. In contrast to haze events over China, the transported haze exhibits low relative humidity (approximately 70%) and high wind speed (approximately 5 m s-1) and is associated with a migrating high-pressure system. The mass concentration of fine particulate matter (PM2.5) for the haze events was 57.1 ± 13.6 μg m-3, nearly four times higher than that of the background (13.7 ± 7.4 μg m-3). Such high PM levels persisted for 120 h in winter. Back trajectory analysis suggests that the haze particles were transported from the east coast of China, particularly from the Yangtze River Delta (YRD) area with a traveling time of nearly 28 h. Lidar observations clarify that the Chinese haze was transported to Northern Taiwan and accompanied by low clouds and a temperature inversion layer, which confined the particles to a height of less than 1 km. Moreover, a relatively high PM2.5 concentration (65.0 μg m-3) was observed when air mass stagnated over YRD before advancing to Taiwan. This scenario, most frequently seen in the winter of 2013, resulted in the highest historical PM2.5 concentration (approximately 77.2 μg m-3). We propose that the heavy haze year is primarily attributable to synoptic weather variability and less to climate.

  7. Formation mechanism of continuous extreme haze episodes in the megacity Beijing, China, in January 2013

    Science.gov (United States)

    Yang, Yiru; Liu, Xingang; Qu, Yu; Wang, Jingli; An, Junling; Zhang, Yuanhangi; Zhang, Fang

    2015-03-01

    The primary objective of this study is to investigate the formation and evolution mechanism of the regional haze in Beijing by analyzing the process of a severe haze episode that occurredfrom1 to 31 January 2013. The mass concentration of PM2.5 and its chemical components were simultaneously measured at the Beijing urban atmospheric environmental monitoring station. The haze was characterized by a high frequency, a long duration, a large influential region and an extremely high PM2.5 values (> 500 μg/m3). The primary factors driving the haze formation were stationary atmospheric flows (in both vertical and horizontal directions), while a temperature inversion, a lower planetary boundary layer and a higher RH accelerated the formation of the regional haze. In one incident, the temperature inversion layer occurred at a height of 130 m above ground level, which prevented the air pollutants from being dispersed vertically. The regional transport of pollutants also played an important role in the formation of the haze. Wind from the south of Beijing increased from 58% in January 2012 to 63% in January 2013. Because the area to the south of Beijing is characterized by high industrial development, the unusual wind direction favored the regional transport of pollutants and severely exacerbated the haze. SO42-, NO3- and NH4+ are the three major water-soluble ions that contributed to the formation of the haze. The high variability in Cl- and K+ indicated that large quantities of coal combustion and biomass burning occurred during the haze.

  8. 浅谈雾和霾%Discussion on Fog and Haze

    Institute of Scientific and Technical Information of China (English)

    苗万强

    2013-01-01

    The paper discusses the causes, hazards of fog and haze, describes the influence of fog and haze on people's lives and puts forward scientific methods control fog and haze.%从雾和霾的成因、危害等方面的不同,进行了详细的论述,阐述了雾和霾对人们生活的影响,提出了应对雾和霾,科学预防、减小危害的方法。

  9. Effect of onion extract on corneal haze suppression after air assisted lamellar keratectomy

    OpenAIRE

    Kim, Soohyun; Park, Young Woo; LEE, Euiri; PARK, Sang Wan; Park, Sungwon; Noh, Hyunwoo; Kim, Jong Whi; Seong, Je Kyung; SEO, Kangmoon

    2015-01-01

    This study evaluated the effect of onion extract on corneal haze suppression after applying the air assisted lamellar keratectomy. The air assisted lamellar keratectomy was performed on 24 canine eyes. They were treated with an artificial tear (group C), prednisolone acetate (group P), onion extract (group O) and TGF-β1 (group T) three times per day from 7 to 28 days after the surgery. Corneal haze occurred on the all eyes and was observed beginning 7 days after the surgery. The haze was sign...

  10. Unlinking absorption and haze in thin film silicon solar cells front electrodes

    OpenAIRE

    Boccard, Mathieu; Cuony, Peter; Battaglia, Corsin; Despeisse, Matthieu; Ballif, Christophe

    2010-01-01

    We study the respective influence of haze and free carrier absorption (FCA) of transparent front electrodes on the photogenerated current of micromorph thin film silicon solar cells. To decouple the haze and FCA we develop bi-layer front electrodes: a flat indium tin oxide layer assures conduction and allows us to tune FCA while the haze is adjusted by varying the thickness of a highly transparent rough ZnO layer. We show how a minimum amount of FCA leads only to a few percents absorption for...

  11. Origin of haze in the central United States and its effect on solar irradiation

    International Nuclear Information System (INIS)

    The depletion by atmospheric haze of solar irradiation at the earth's surface in the central United States is estimated and some aspects of the origin of the haze investigated. Observed optical properties of the haze are reviewed and their relation to visual range measurements demonstrated. An approximate radiative transfer model relates visual range and mixing-height observations to solar irradiance at the ground, and the relation is validated against detailed irradiance observations on two days, and against observed monthly and annual irradiation at one station. Statistics of irradiation depletion are computed for 24 stations. The annual average depletion is approx.7.5%

  12. Latitudinal variations in Titan's methane and haze from Cassini VIMS observations

    Science.gov (United States)

    Penteado, P.F.; Griffith, C.A.; Tomasko, M.G.; Engel, S.; See, C.; Doose, L.; Baines, K.H.; Brown, R.H.; Buratti, B.J.; Clark, R.; Nicholson, P.; Sotin, C.

    2010-01-01

    We analyze observations taken with Cassini's Visual and Infrared Mapping Spectrometer (VIMS), to determine the current methane and haze latitudinal distribution between 60??S and 40??N. The methane variation was measured primarily from its absorption band at 0.61 ??m, which is optically thin enough to be sensitive to the methane abundance at 20-50 km altitude. Haze characteristics were determined from Titan's 0.4-1.6 ??m spectra, which sample Titan's atmosphere from the surface to 200 km altitude. Radiative transfer models based on the haze properties and methane absorption profiles at the Huygens site reproduced the observed VIMS spectra and allowed us to retrieve latitude variations in the methane abundance and haze. We find the haze variations can be reproduced by varying only the density and single scattering albedo above 80 km altitude. There is an ambiguity between methane abundance and haze optical depth, because higher haze optical depth causes shallower methane bands; thus a family of solutions is allowed by the data. We find that haze variations alone, with a constant methane abundance, can reproduce the spatial variation in the methane bands if the haze density increases by 60% between 20??S and 10??S (roughly the sub-solar latitude) and single scattering absorption increases by 20% between 60??S and 40??N. On the other hand, a higher abundance of methane between 20 and 50 km in the summer hemisphere, as much as two times that of the winter hemisphere, is also possible, if the haze variations are minimized. The range of possible methane variations between 27??S and 19??N is consistent with condensation as a result of temperature variations of 0-1.5 K at 20-30 km. Our analysis indicates that the latitudinal variations in Titan's visible to near-IR albedo, the north/south asymmetry (NSA), result primarily from variations in the thickness of the darker haze layer, detected by Huygens DISR, above 80 km altitude. If we assume little to no latitudinal methane

  13. Structure of Haze Forming Proteins in White Wines: Vitis vinifera Thaumatin-Like Proteins

    OpenAIRE

    Marangon, Matteo; Van Sluyter, Steven C.; Waters, Elizabeth J.; Menz, Robert I.

    2014-01-01

    Grape thaumatin-like proteins (TLPs) play roles in plant-pathogen interactions and can cause protein haze in white wine unless removed prior to bottling. Different isoforms of TLPs have different hazing potential and aggregation behavior. Here we present the elucidation of the molecular structures of three grape TLPs that display different hazing potential. The three TLPs have very similar structures despite belonging to two different classes (F2/4JRU is a thaumatin-like protein while I/4L5H ...

  14. Titan's Detached Haze as a Test of Circulation and Microphysical Models

    Science.gov (United States)

    West, R. A.

    2011-12-01

    In 1981 Voyager ISS images showed a thin, high haze layer above Titan's main haze. Rages and Pollack (Icarus 55, 50-62, 1983) measured the altitude of this so-called detached haze to be at 357 km at the equator and about 27 km lower in the high southern latitudes. In the Voyager images and later in the Cassini ISS images starting in 2004 the detached haze was observed to be present and continuous over all latitudes south of the northern polar vortex boundary, but in the Cassini images beginning in 2004 the altitude of the haze was significantly higher (just over 500 km ) and more circular. West et al. (Geophys. Res. Lett., 38, L06204, doi:10.1029/2011GL046843, 2011) tracked the altitude of the haze from 2004 to August of 2010, and found that the altitude dropped dramatically and most rapidly near equinox in 2009. More recent images taken in 2011 show the altitude to be the same, within a few km, as the altitude measured by Rages and Pollack almost 30 earth years and one Titan year earlier. Two very different models to explain the existence and properties of the detached were put forward prior to the observation of the altitude shift. One by Rannou et al. (Nature 418, 853-856, 2002) produces the detached haze via a global meridional cell and includes seasonal variations. Another by Lavvas et al. (Icarus, 201, 626-633, doi:10.1016/j.icarus.2009.01.004, 2009), produces the haze by a purely steady-state microphysical mechanism and must be coupled with a dynamical process to produce the evolution. The collapse of Titan's detached haze is most likely a feature of the breakdown of a global meridional cell in the high stratosphere at equinox as solar heating becomes symmetric, although the haze does not disappear with the change in altitude as predicted by the model of Rannou et al.. The detached haze, a scientific curiosity for almost 30 years, has become an incisive test for Titan circulation and haze microphysical models. Part of this work was performed by the Jet

  15. Silver nanowires decorated with silver nanoparticles for low-haze flexible transparent conductive films

    OpenAIRE

    Mini Mol Menamparambath; Muhammed Ajmal, C.; Kwang Hee Kim; Daejin Yang; Jongwook Roh; Hyeon Cheol Park; Chan Kwak; Jae-Young Choi; Seunghyun Baik

    2015-01-01

    Silver nanowires have attracted much attention for use in flexible transparent conductive films (TCFs) due to their low sheet resistance and flexibility. However, the haze was too high for replacing indium-tin-oxide in high-quality display devices. Herein, we report flexible TCFs, which were prepared using a scalable bar-coating method, with a low sheet resistance (24.1 Ω/sq at 96.4% transmittance) and a haze (1.04%) that is comparable to that of indium-tin-oxide TCFs. To decrease the haze an...

  16. Co-precipitation synthesis of nano-composites consists of zinc and tin oxides coatings on glass with enhanced photocatalytic activity on degradation of Reactive Blue 160 KE2B.

    Science.gov (United States)

    Habibi, Mohammad Hossein; Mardani, Maryam

    2015-02-25

    Nano-composite containing zinc oxide-tin oxide was obtained by a facile co-precipitation route using tin chloride tetrahydrate and zinc chloride as precursors and coated on glass by Doctor Blade deposition. The crystalline structure and morphology of composites were evaluated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The XRD results showed peaks relative to zinc oxide with hexagonal wurtzite structure and tin oxide with tetragonal structure. FESEM observations showed that the nano-composite consisted of aggregates of particles with an average particle size of 18 nm. The photocatalytic activity of the pure SnO2, pure ZnO, ZnSnO3-Zn2SnO4 and ZnO-SnO2 nano-structure thin films was examined using the degradation of a textile dye Reactive Blue 160 (KE2B). ZnO-SnO2 nano-composite showed enhanced photo-catalytic activity than the pure zinc oxide and tin oxide. The enhanced photo-catalytic activity of the nano-composite was ascribed to an improved charge separation of the photo-generated electron-hole pairs. PMID:25265524

  17. Developing the urban blue: Comparative health responses to blue and green urban open spaces in Germany.

    Science.gov (United States)

    Völker, Sebastian; Kistemann, Thomas

    2015-09-01

    Recently, new perspectives upon healthy urban open spaces propose that open spaces can be regarded as urban green or blue spaces. However, there has so far been very little research into blue environments and their benefits for mental well-being. Our article focuses on the effects of water in cities, "urban blue" (as compared to "urban green"), on human health and well-being. To assess the mental well-being of visitors, we conducted qualitative semi-standardised interviews (n=113), asking which differences in well-being occur when visiting urban green and blue spaces in high-density areas of the inner city in Dusseldorf and Cologne, Germany. Although we found many similarities, some health-enhancing effects for users turned out to be prominent for urban blue in the four conceptual therapeutic landscape dimensions: experienced, symbolic, social and activity space. These effects include enhanced contemplation, emotional bonding, participation, and physical activity. The results suggest that urban blue as a health-promoting factor needs more detailed and accurate determination and examination of its general and local health-enhancing effects. PMID:25475835

  18. New York Blue

    Data.gov (United States)

    Federal Laboratory Consortium — New York Blue is used cooperatively by the Laboratory and Stony Brook University as part of the New York Center for Computation Sciences. Ranked as the 28th fastest...

  19. Code blue: seizures.

    Science.gov (United States)

    Hoerth, Matthew T; Drazkowski, Joseph F; Noe, Katherine H; Sirven, Joseph I

    2011-06-01

    Eyewitnesses frequently perceive seizures as life threatening. If an event occurs on the hospital premises, a "code blue" can be called which consumes considerable resources. The purpose of this study was to determine the frequency and characteristics of code blue calls for seizures and seizure mimickers. A retrospective review of a code blue log from 2001 through 2008 identified 50 seizure-like events, representing 5.3% of all codes. Twenty-eight (54%) occurred in inpatients; the other 22 (44%) events involved visitors or employees on the hospital premises. Eighty-six percent of the events were epileptic seizures. Seizure mimickers, particularly psychogenic nonepileptic seizures, were more common in the nonhospitalized group. Only five (17.9%) inpatients had a known diagnosis of epilepsy, compared with 17 (77.3%) of the nonhospitalized patients. This retrospective survey provides insights into how code blues are called on hospitalized versus nonhospitalized patients for seizure-like events. PMID:21546315

  20. Visualising DNA in Classrooms Using Nile Blue

    Science.gov (United States)

    Milne, Christine; Roche, Scott; McKay, David

    2008-01-01

    Giving students the opportunity to extract, manipulate and visualise DNA molecules enhances a constructivist approach to learning about modern techniques in biology and biotechnology Visualisation usually requires agarose gel electrophoresis and staining. In this article, we report on an alternative DNA stain, Nile Blue A, that may be used in the…

  1. Efficient Blue-Colored Solid-State Dye-Sensitized Solar Cells: Enhanced Charge Collection by Using an in Situ Photoelectrochemically Generated Conducting Polymer Hole Conductor.

    Science.gov (United States)

    Zhang, Jinbao; Vlachopoulos, Nick; Hao, Yan; Holcombe, Thomas W; Boschloo, Gerrit; Johansson, Erik M J; Grätzel, Michael; Hagfeldt, Anders

    2016-05-18

    A high power conversion efficiency (PCE) of 5.5 % was achieved by efficiently incorporating a diketopyrrolopyrrole-based dye with a conducting polymer poly(3,4-ethylenediothiophene) (PEDOT) hole-transporting material (HTM) that was formed in situ, compared with a PCE of 2.9 % for small molecular spiro-OMeTAD-based solid-state dye solar cells (sDSCs). The high PCE for PEDOT-based sDSCs is mainly attributed to the significantly enhanced charge-collection efficiency, as a result of the three-order-of-magnitude higher hole conductivity (0.53 S cm(-1) ) compared with that of the widely used low molecular weight HTM spiro-OMeTAD (3.5×10(-4)  S cm(-1) ). PMID:26919196

  2. Structure of haze forming proteins in white wines: Vitis vinifera thaumatin-like proteins.

    Directory of Open Access Journals (Sweden)

    Matteo Marangon

    Full Text Available Grape thaumatin-like proteins (TLPs play roles in plant-pathogen interactions and can cause protein haze in white wine unless removed prior to bottling. Different isoforms of TLPs have different hazing potential and aggregation behavior. Here we present the elucidation of the molecular structures of three grape TLPs that display different hazing potential. The three TLPs have very similar structures despite belonging to two different classes (F2/4JRU is a thaumatin-like protein while I/4L5H and H2/4MBT are VVTL1, and having different unfolding temperatures (56 vs. 62°C, with protein F2/4JRU being heat unstable and forming haze, while I/4L5H does not. These differences in properties are attributable to the conformation of a single loop and the amino acid composition of its flanking regions.

  3. Aspartic acid protease from Botrytis cinerea removes haze-forming proteins during white winemaking.

    Science.gov (United States)

    Van Sluyter, Steven C; Warnock, Nicholas I; Schmidt, Simon; Anderson, Peter; van Kan, Jan A L; Bacic, Antony; Waters, Elizabeth J

    2013-10-01

    White wines suffer from heat-induced protein hazes during transport and storage unless the proteins are removed prior to bottling. Bentonite fining is by far the most commonly used method, but it is inefficient and creates several other process challenges. An alternative to bentonite is the enzymatic removal of haze-forming grape pathogenesis-related proteins using added proteases. The major problem with this approach is that grape pathogenesis-related proteins are highly protease resistant unless they are heat denatured in combination with enzymatic treatment. This paper demonstrates that the protease BcAP8, from the grape fungal pathogen Botrytis cinerea , is capable of degrading chitinase, a major class of haze-forming proteins, without heat denaturation. Because BcAP8 effectively removes haze-forming proteins under normal winemaking conditions, it could potentially benefit winemakers by reducing bentonite requirements. PMID:24007329

  4. Structure of haze forming proteins in white wines: Vitis vinifera thaumatin-like proteins.

    Science.gov (United States)

    Marangon, Matteo; Van Sluyter, Steven C; Waters, Elizabeth J; Menz, Robert I

    2014-01-01

    Grape thaumatin-like proteins (TLPs) play roles in plant-pathogen interactions and can cause protein haze in white wine unless removed prior to bottling. Different isoforms of TLPs have different hazing potential and aggregation behavior. Here we present the elucidation of the molecular structures of three grape TLPs that display different hazing potential. The three TLPs have very similar structures despite belonging to two different classes (F2/4JRU is a thaumatin-like protein while I/4L5H and H2/4MBT are VVTL1), and having different unfolding temperatures (56 vs. 62°C), with protein F2/4JRU being heat unstable and forming haze, while I/4L5H does not. These differences in properties are attributable to the conformation of a single loop and the amino acid composition of its flanking regions. PMID:25463627

  5. Haze defect control and containment in a high volume DRAM manufacturing environment

    Science.gov (United States)

    Chen, Jerry X.; Nguyen, Maihan; Arasaki, Osamu; Maraquin, Tammy; Sawyer, Daniel; Morrison, Pedro

    2005-11-01

    Haze and other progressive reticle defects have been known in the semiconductor industry for more than a decade [1]. Extensive research and experiments have been carried out to determine the sources and origins of the progressive haze growth, but the true mechanisms of its cause are still under speculation. To minimize the wafer yield loss at Samsung Austin Semiconductor (SAS), we introduced a practical method to control the haze defects in a DRAM manufacturing environment that integrates reticle and wafer inspections, reticle cleaning, and a dose-based and time-based control forecast software system. This development has been proven to be very effective in controlling the haze defects and reducing the related yield loss while still supporting high volume wafer production.

  6. Scanning confocal slit photon counter measurements of post-PRK haze in two-year study

    Science.gov (United States)

    Taboada, John; Gaines, David; Perez, Mary A.; Waller, Steve G.; Ivan, Douglas J.; Baldwin, J. Bruce; LoRusso, Frank; Tutt, Ronald C.; Thompson, B.; Perez, Jose; Tredici, Thomas; Johnson, Dan A.

    2001-06-01

    In our study, a group of 80 United States Air Force, non- flying personnel will undergo photorefractive corneal surgery for moderate levels of myopia (treatment. Of these, only about 59% of the treated eyes showed even a trace (.5) level of clinically assessed haze at any time. We report on the use of a recently developed instrument designed for the objective measurement of these low levels of haze in treated corneas. The sensitivity of the instrument is derived from the use of a scanning confocal slit photon counter. The use of a physical standard for calibration secures accuracy and reproducibility over an extensive period of time. Our haze measurements in this study revealed a very low level increase from baseline values for these patients. The typical increase over baseline was of the same magnitude as the variability in the observations, although the inherent variability in the measurements was approximately 0.25 times the value of the patient's haze variability.

  7. The Blues of David Lynch

    OpenAIRE

    Roche, David

    2009-01-01

    This article is an attempt to elaborate a typology of the color blue in the color films of David Lynch up to and including Mulholland Drive (2001). The color blue is considered alternately as light, matter or verbal language. The author studies the use, function, value and meaning of blue lighting, divided into static and flashing light, and of the blue objects in Blue Velvet (1986) and Mulholland Drive. The author shows how Lynch appropriates connotations Western culture, under the influence...

  8. Cadmium oxide nanoparticles grown in situ on reduced graphene oxide for enhanced photocatalytic degradation of methylene blue dye under ultraviolet irradiation.

    Science.gov (United States)

    Kumar, Sumeet; Ojha, Animesh K; Walkenfort, Bernd

    2016-06-01

    Cadmium oxide (CdO) nanoparticles (NPs), reduced graphene oxide (rGO) and rGO-CdO nanocomposites have been synthesized using one step hydrothermal method. The structural and optical properties of CdO NPs, rGO, and rGO-CdO nanocomposites were investigated by X-ray diffraction (XRD), energy dispersive X-ray (EDX), high resolution transmission electron microscopy (HR-TEM), Raman spectroscopy (RS), ultraviolet-visible spectroscopy (UV-Vis.) and photoluminescence (PL) spectroscopy techniques. The rGO has a sharp 2D peak compared to GO. The sharp nature of 2D band may be due to the larger contribution from single layer sheet. The photocatalytic activity of the synthesized samples has been investigated under UV irradiation. The results of photocatalytic measurements revealed that ~80% of MB dye is degraded by adding the rGO-CdO nanocomposites as photocatalysts into the dye solution. The decrease in the intensity of emission peaks indicates that the photogenerated charge carriers have been transferred from CdO NPs to rGO sheets, which causes to increase the density of O2(-) and OH radicals in the dye solution. The CdO nanoparticles gown on the rGO sheets showed enhanced ferromagnetism (FM) at room temperature, which may be attributed to the short range magnetic interaction of magnetic moments of CdO NPs and spin units present on the rGO sheets. PMID:27045279

  9. Understanding the recent trend of haze pollution in eastern China: roles of climate change

    Science.gov (United States)

    Wang, Hui-Jun; Chen, Huo-Po

    2016-04-01

    In this paper, the variation and trend of haze pollution in eastern China for winter of 1960-2012 were analyzed. With the overall increasing number of winter haze days in this period, the 5 decades were divided into three sub-periods based on the changes of winter haze days (WHD) in central North China (30-40° N) and eastern South China (south of 30° N) for east of 109° E mainland China. Results show that WHD kept gradually increasing during 1960-1979, remained stable overall during 1980-1999, and increased fast during 2000-2012. The author identified the major climate forcing factors besides total energy consumption. Among all the possible climate factors, variability of the autumn Arctic sea ice extent, local precipitation and surface wind during winter is most influential to the haze pollution change. The joint effect of fast increase of total energy consumption, rapid decline of Arctic sea ice extent and reduced precipitation and surface winds intensified the haze pollution in central North China after 2000. There is a similar conclusion for haze pollution in eastern South China after 2000, with the precipitation effect being smaller and spatially inconsistent.

  10. Changes in chemical components of aerosol particles in different haze regions in China from 2006 to 2013 and contribution of meteorological factors

    Science.gov (United States)

    Zhang, X. Y.; Wang, J. Z.; Wang, Y. Q.; Liu, H. L.; Sun, J. Y.; Zhang, Y. M.

    2015-11-01

    significant changes. In the Pearl River Delta (PRD) area, the regional background concentrations of the major chemical components were similar to those in the YRD, accounting for approximately 60-80 % of those in HBP. Since 2010, a decline has been found for winter concentrations, which can be partially attributable to persistently improving meteorological conditions and emission cutting with an emphasis on coal combustion in this area. In addition to the scattered and centralized coal combustion for heating, burning biomass fuels contributed to the large increase in concentrations of carbonaceous aerosol in major haze regions in winter, except in the PRD. No obvious changes were found for the proportions of each chemical components of PM10 from 2006 to 2013. Among all of the emissions recorded in chemical compositions in 2013, coal combustion was still the largest anthropogenic source of aerosol pollution in various areas in China, with a higher sulfate proportion of PM10 in most areas of China, and OC was normally ranked third. PM10 concentrations increased by approximately 25 % in January of 2013 relative to 2012, which caused persistent haze-fog events in HBP; emissions also reduced by approximately 35 % in Beijing and its vicinity (BIV) in late autumn of 2014, thereby producing the Asia Pacific Economic Cooperation (APEC) blue (extremely good air quality); thus, one can expect that the persistent haze-fog events would be reduced significantly in the BIV, if approx. one-third of the 2013 winter emissions were reduced, which can also be viewed as the upper limit of atmospheric aerosol pollution capacity in this area.

  11. Changes in chemical components of aerosol particles in different haze regions in China from 2006 to 2013 and contribution of meteorological factors

    Directory of Open Access Journals (Sweden)

    X. Y. Zhang

    2015-07-01

    components were similar to those in YRD; accounted approximately 60–80 % of these in HBP. Since 2010, a decline was found for winter concentrations, which can be partially attributable to a persistent bettering meteorological conditions and the emission cutting with an emphasis on coal-combustion in this area. In addition to the scattered and centralized coal-combustion for heating, burning biomass fuel contributed to the large increase in the concentrations of carbonaceous aerosol in major haze regions, except in PRD, in winter. No obvious changes were found for the proportions of each chemical components of PM10 from 2006 to 2013. Among all of the emissions recorded in chemical compositions in 2013, coal-combustion was still the largest anthropogenic source of aerosol pollution in various areas in China, with higher sulphate proportion of PM10 in most areas of China. OC normally ranked the third. PM10 concentration increased by approximately 25 % in January of 2013 relative to 2012 that caused persistent haze-fog events in HBP; emission also reduced by approximately 35 % in Beijing and its vicinity (BIV in late fall of 2014, thereby producing "APEC" blue; thus one can expect that the persistent haze-fog events would be reduced significantly in the BIV, if ~ one-third of the 2013 winter emission could be reduced, which can also be viewed as the upper limit of atmospheric aerosol pollution capacity in this area.

  12. The distribution and trends of fog and haze in the North China Plain over the past 30 years

    Directory of Open Access Journals (Sweden)

    G. Q. Fu

    2014-06-01

    Full Text Available Frequent low visibility, haze and fog events were found in the North China Plain (NCP. Data throughout the NCP during the past 30 years were examined to determine the horizontal distribution and decadal trends of low visibility, haze and fog events. The impact of meteorological factors such as wind and RH on those events was investigated. Results reveal distinct distributions of haze and fog days, due to their different formation mechanisms. Low visibility, haze and fog days all display increasing trends of before 1995, a steady stage during 1995–2003 and a drastically drop thereafter. All three events occurred most frequently during the heating season. Benefiting from emission control measures, haze and fog both show decreasing trends in winter during the past 3 decades, while summertime haze displays continuous increasing trends. The distribution of wind speed and wind direction as well as the topography within the NCP has determinative impacts on the distribution of haze and fog. Weakened south-easterly winds in the southern part of the NCP has resulted in high pollutant concentrations and frequent haze events along the foot of the Taihang Mountains. The orographic wind convergence zone in the central band area of the southern NCP is responsible for the frequent fog events in this region. Wind speed has been decreasing throughout the entire southern NCP, resulting in more stable atmospheric conditions and weaker dispersion abilities, calling for harder efforts to control emissions to prevent haze events. Haze events are strongly influenced by the ambient RH. RH values associated with haze days are evidently increasing, suggesting that an increasing fraction of haze events are caused by the hygroscopic growth of aerosols, rather than simply by high aerosol loadings.

  13. [Chemical Characteristics of Particulate Matters and Trajectory Influence on Air Quality in Shanghai During the Heavy Haze Episode in December, 2013].

    Science.gov (United States)

    Zhou, Min; Qiao, Li-ping; Zhu, Shu-hui; Li, Li; Lou, Sheng-rong; Wang, Hong-li; Tao, Shi-kang; Huang, Cheng; Chen, Chang-hong

    2016-04-15

    Intensive haze shrouded central and eastern parts of China in Dec. 2013. In this study, the mass concentrations of gaseous and particulate pollutants, and also the chemical compositions of fine particulate matters were obtained based on in-situ measurement in Shanghai urban area. The characteristics of PM2.5 were investigated during different pollution episodes, including dust, haze, fog-haze and long-rang transport episodes. The results showed that pollution was most serious during the fog-haze episode, during which the maximum daily mass concentrations of PM10 and PM2.5 reached 536 microg x m(-3) and 411 microg x m(-3), respectively. During the fog-haze episode, the ratio of PM2.5 to PM10 was over 76.7%, suggesting that high humidity enhanced the secondary formation of NO3-, SO4(2-) and NH4+ in PM2.5. Highest concentration of Ca2+ in PM2.5 occurred during the dust episode and the proportion of primary components in PM2.5 increased obviously. Highest concentration of SO2- was observed in PM25 during the long-range transport episode, with a fast growth rate. Meanwhile, the trajectories reaching Shanghai urban area and cluster analysis during different pollution episodes were simulated by HYSPLIT model. Combined with observation data of PM2.5 in Shanghai urban area, chemical characteristics of PM2.5 in different clusters and potential source apportionment of various pollution episodes were also studied in this study. The result revealed that the air trajectories could be grouped into six clusters based on their spatial similarities. Among these clusters, cluster6 which moved fast was associated with clean air. Cluster2 and cluster3 originating from Mongolia region had strong correlations to dust pollution, along with low PM2.5/PM10 ratio and high concentration of Ca2+ in PM2.5. Compared with other clusters, cluster5 and cluster4 with slow moving speed were more favorable for reactions between particulate species and formation of secondary pollutants during transport

  14. Beyond Deep Blue

    CERN Document Server

    Newborn, Monty

    2011-01-01

    More than a decade has passed since IBM's Deep Blue computer stunned the world by defeating Garry Kasparov, the world chess champion at that time. Beyond Deep Blue tells the continuing story of the chess engine and its steady improvement. The book provides analysis of the games alongside a detailed examination of the remarkable technological progress made by the engines - asking which one is best, how good is it, and how much better can it get. Features: presents a total of 118 games, played by 17 different chess engines, collected together for the first time in a single reference; details the

  15. The Blue Collar Brain

    Directory of Open Access Journals (Sweden)

    Guy eVan Orden

    2012-06-01

    Full Text Available Much effort has gone into elucidating control of the body by the brain, less so the role of the body in controlling the brain. This essay develops the idea that the brain does a great deal of work in the service of behavior that is controlled by the body, a blue collar role compared to the white collar control exercised by the body. The argument that supports a blue collar role for the brain is also consistent with recent discoveries clarifying the white collar role of synergies across the body's tensegrity structure, and the evidence of critical phenomena in brain and behavior.

  16. The "Blue Banana" Revisited

    NARCIS (Netherlands)

    Faludi, A.K.F.

    2015-01-01

    This essay is about the “Blue Banana”. Banana is the name given subsequently by others to a Dorsale européenne (European backbone) identified empirically by Roger Brunet. In a background study to the Communication of the European Commission ‘Europe 2000’, Klaus Kunzmann and Michael Wegener put forwa

  17. Blue spectral inflation

    CERN Document Server

    Schunck, Franz E

    2008-01-01

    We reconsider the nonlinear second order Abel equation of Stewart and Lyth, which follows from a nonlinear second order slow-roll approximation. We find a new eigenvalue spectrum in the blue regime. Some of the discrete values of the spectral index n_s have consistent fits to the cumulative COBE data as well as to recent ground-base CMB experiments.

  18. Insights into a historic severe haze weather in Shanghai: synoptic situation, boundary layer and pollutants

    Science.gov (United States)

    Leng, C.; Duan, J.; Xu, C.; Zhang, H.; Zhang, Q.; Wang, Y.; Li, X.; Kong, L.; Tao, J.; Cheng, T.; Zhang, R.; Chen, J.

    2015-11-01

    A historic winter haze weather, characterized by long duration, large scale and strong pollution intensity, occurred in the Yangtze River Delta (YRD) region of China during the time frame of 1 to 10 December 2013. This severe haze event constituted of several hazy episodes and significantly influenced air quality throughout the region, especially in urban areas. Aerosol physical, chemical and optical properties were measured in Shanghai, where the instantaneous particulate mass burden per volume (e.g. PM2.5) exceeded 600 μg m-3 in some time, breaking the existing historical observation records, and examined to give insights into severe haze weathers. Inorganic water-soluble ions in particles, trace gases and aerosol scattering/absorption coefficients had the same tendency to increase evidently from clear episodes to hazy episodes. A combination of various factors contributed to the formation and evolution of the severe haze, among which meteorological conditions, local anthropogenic emissions and aerosol properties played the major roles. During the haze weather, the YRD region was under the control of a high-pressure system with extremely small surface pressure gradients. The calm surface wind and subsidence airflow were responsible for decreasing planetary boundary layer (PBL) height and constructive to the build-up of air pollutants wandering inside the region, and ultimately induced the haze occurrence. Nonlinear regression analyses indicated that single water-soluble ion did not correlated with the atmospheric visibility degradation so strong, while high ambient relative humidity (RH) indeed exerted a great impact with a correlation coefficient (R2) of 0.41. Moreover, the close relationship was derived between atmospheric visibility and aerosols in size of 600-1400 nm with R2 of 0.70, which further improved to 0.73 when combined aerosol hygroscopicity. This study may provide supports for the public and authorities to recognize severe haze weathers in urban

  19. Characteristics of aerosol pollution during heavy haze events in Suzhou, China

    Science.gov (United States)

    Tian, M.; Wang, H. B.; Chen, Y.; Yang, F. M.; Zhang, X. H.; Zou, Q.; Zhang, R. Q.; Ma, Y. L.; He, K. B.

    2015-11-01

    A comprehensive measurement was carried out to analyze the heavy haze events in Suzhou in January 2013 when extremely severe haze pollution occurred in many cities in China especially in the East. Hourly concentrations of PM2.5, chemical composition (including water-soluble inorganic ions, OC, and EC), and gas-phase precursors were obtained via on-line monitoring system. Based on these data, detailed aerosol composition, light extinction and gas-phase precursors were analyzed to understand the characteristics of the haze events, moreover, the formation mechanism of nitrate and sulfate in PM2.5 and the regional sources deduced from trajectory and PSCF were discussed to explore the origin of the heavy aerosol pollution. The results showed that frequent haze events were occurred on January 2013 and the concentrations of PM2.5 often exceeded 150 μg m-3 during the haze occurrence, with a maximum concentration of 324 μg m-3 on 14 January 2013. Unfavorable weather conditions (high RH, and low rainfall, wind speed and atmospheric pressure), high concentration of secondary aerosol species (including SO42-, NO3-, NH4+, and SOC) and precursors were observed during the haze events. Additionally, OM, (NH4)2SO4, NH4NO3 were demonstrated to be the major contributors to the visibility impairment but the share differed from haze events. This study also found that the high concentration of sulfate might be explained by the heterogeneous reactions in the aqueous surface layer of pre-existing particles or in cloud processes while nitrate might be mainly formed through homogeneous gas-phase reactions. The results of trajectory clustering and the PSCF method manifested that aerosol pollutions in the studied areas were mainly affected by local activities and surrounding sources transported from nearby cities.

  20. III-nitride blue microdisplays

    International Nuclear Information System (INIS)

    Prototype blue microdisplays have been fabricated from InGaN/GaN quantum wells. The device has a dimension of 0.5x0.5mm2 and consists of 10x10 pixels 12 μm in diameter. Emission properties such as electroluminescence spectra, output power versus forward current (L--I) characteristic, viewing angle, and uniformity have been measured. Due to the unique properties of III-nitride wide-band-gap semiconductors, microdisplays fabricated from III nitrides can potentially provide unsurpassed performance, including high-brightness/resolution/contrast, high-temperature/high-power operation, high shock resistance, wide viewing angles, full-color spectrum capability, long life, high speed, and low-power consumption, thus providing an enhancement and benefit to the present capabilities of miniature display systems

  1. Experimental Study on Interactions Between H Atoms and Organic Haze

    Science.gov (United States)

    Sekine, Y.; Imanaka, H.; Khare, B. N.; Bakes, E. L. O.; McKay, C. P.; Sugita, S.; Matsui, T.

    2005-01-01

    In Titan s atmosphere composed of N2 and CH4, irradiations of both solar ultraviolet light and charged particles induce active chemical reactions. In the processes of these reactions, a large amount of hydrogen (H) atoms are expected to be formed by dissociation of CH4 and other hydrocarbons [e.g., 1, 2]. Theoretical models suggest that these active H atoms need to be converted to stable hydrogen molecules (H2) efficiently to maintain unsaturated hydrocarbons and organic haze in Titan s atmosphere [e.g., 1]. Furthermore, molecular hydrogen is an important greenhouse effect gas in Titan s atmosphere, and small variation in its abundance strongly affects Titan s surface temperature [3]. Thus, the formation of H2 molecules from H atoms is a key reaction for both the atmospheric chemistry and the surface environment of Titan. Although several numerical calculations have been conducted to investigate the atmospheric chemistry of Titan with hypothesized recombination reactions of H atoms, such as catalytic scheme of C4H2 [e.g., 1, 2], it is still unclear what chemical reaction is responsible for the conversion of H atoms to H2 molecules in Titan s atmosphere.

  2. A case-crossover analysis of forest fire haze events and mortality in Malaysia

    Science.gov (United States)

    Sahani, Mazrura; Zainon, Nurul Ashikin; Wan Mahiyuddin, Wan Rozita; Latif, Mohd Talib; Hod, Rozita; Khan, Md Firoz; Tahir, Norhayati Mohd; Chan, Chang-Chuan

    2014-10-01

    The Southeast Asian (SEA) haze events due to forest fires are recurrent and affect Malaysia, particularly the Klang Valley region. The aim of this study is to examine the risk of haze days due to biomass burning in Southeast Asia on daily mortality in the Klang Valley region between 2000 and 2007. We used a case-crossover study design to model the effect of haze based on PM10 concentration to the daily mortality. The time-stratified control sampling approach was used, adjusted for particulate matter (PM10) concentrations, time trends and meteorological influences. Based on time series analysis of PM10 and backward trajectory analysis, haze days were defined when daily PM10 concentration exceeded 100 μg/m3. The results showed a total of 88 haze days were identified in the Klang Valley region during the study period. A total of 126,822 cases of death were recorded for natural mortality where respiratory mortality represented 8.56% (N = 10,854). Haze events were found to be significantly associated with natural and respiratory mortality at various lags. For natural mortality, haze events at lagged 2 showed significant association with children less than 14 years old (Odd Ratio (OR) = 1.41; 95% Confidence Interval (CI) = 1.01-1.99). Respiratory mortality was significantly associated with haze events for all ages at lagged 0 (OR = 1.19; 95% CI = 1.02-1.40). Age-and-gender-specific analysis showed an incremental risk of respiratory mortality among all males and elderly males above 60 years old at lagged 0 (OR = 1.34; 95% CI = 1.09-1.64 and OR = 1.41; 95% CI = 1.09-1.84 respectively). Adult females aged 15-59 years old were found to be at highest risk of respiratory mortality at lagged 5 (OR = 1.66; 95% CI = 1.03-1.99). This study clearly indicates that exposure to haze events showed immediate and delayed effects on mortality.

  3. A Long-Term Prediction Model of Beijing Haze Episodes Using Time Series Analysis.

    Science.gov (United States)

    Yang, Xiaoping; Zhang, Zhongxia; Zhang, Zhongqiu; Sun, Liren; Xu, Cui; Yu, Li

    2016-01-01

    The rapid industrial development has led to the intermittent outbreak of pm2.5 or haze in developing countries, which has brought about great environmental issues, especially in big cities such as Beijing and New Delhi. We investigated the factors and mechanisms of haze change and present a long-term prediction model of Beijing haze episodes using time series analysis. We construct a dynamic structural measurement model of daily haze increment and reduce the model to a vector autoregressive model. Typical case studies on 886 continuous days indicate that our model performs very well on next day's Air Quality Index (AQI) prediction, and in severely polluted cases (AQI ≥ 300) the accuracy rate of AQI prediction even reaches up to 87.8%. The experiment of one-week prediction shows that our model has excellent sensitivity when a sudden haze burst or dissipation happens, which results in good long-term stability on the accuracy of the next 3-7 days' AQI prediction. PMID:27597861

  4. A Long-Term Prediction Model of Beijing Haze Episodes Using Time Series Analysis

    Directory of Open Access Journals (Sweden)

    Xiaoping Yang

    2016-01-01

    Full Text Available The rapid industrial development has led to the intermittent outbreak of pm2.5 or haze in developing countries, which has brought about great environmental issues, especially in big cities such as Beijing and New Delhi. We investigated the factors and mechanisms of haze change and present a long-term prediction model of Beijing haze episodes using time series analysis. We construct a dynamic structural measurement model of daily haze increment and reduce the model to a vector autoregressive model. Typical case studies on 886 continuous days indicate that our model performs very well on next day’s Air Quality Index (AQI prediction, and in severely polluted cases (AQI ≥ 300 the accuracy rate of AQI prediction even reaches up to 87.8%. The experiment of one-week prediction shows that our model has excellent sensitivity when a sudden haze burst or dissipation happens, which results in good long-term stability on the accuracy of the next 3–7 days’ AQI prediction.

  5. Vertical structure of foggy haze over the Beijing-Tianjin-Hebei area in January 2013

    Science.gov (United States)

    Han, Feng; Xu, Jun; He, Youjiang; Dang, Hongyan; Yang, Xuezhen; Meng, Fan

    2016-08-01

    In January 2013, frequent episodes of intense air pollution occurred in the Beijing-Tianjin-Hebei area (BTH), China. Besides the occurrence of region-wide dry haze pollution, foggy haze conditions also developed across the region on numerous days, lasting into the afternoon. Synergistic analysis, using multisatellite datasets, air sounding and surface meteorological observations, indicated that there was a vertical overlap of fog and aerosol layers during the foggy haze episodes in the region. Fog appeared at a low level of the atmosphere. The altitude of the upper boundary of the fog differed across the region, but it was always below 1 km. The aerosol layer that closely contacted with the top of the underlying fog was rather dense, having a high concentration comparable to that during severe pollution on the ground. Above the dense aerosol layer, aerosol with a concentration equivalent to that of moderate pollution stretched up to an altitude of 2 km. Beyond that, a tenuous aerosol layer extended 5 km into the atmosphere. This overlapping of fog and haze layers frequently occurred across the region in January 2013. The occurrence of a foggy haze over BTH could worsen the regional air quality, and its appearance across this region would have notable effects on the radiation balance.

  6. A Long-Term Prediction Model of Beijing Haze Episodes Using Time Series Analysis

    Science.gov (United States)

    Zhang, Zhongqiu; Sun, Liren; Xu, Cui

    2016-01-01

    The rapid industrial development has led to the intermittent outbreak of pm2.5 or haze in developing countries, which has brought about great environmental issues, especially in big cities such as Beijing and New Delhi. We investigated the factors and mechanisms of haze change and present a long-term prediction model of Beijing haze episodes using time series analysis. We construct a dynamic structural measurement model of daily haze increment and reduce the model to a vector autoregressive model. Typical case studies on 886 continuous days indicate that our model performs very well on next day's Air Quality Index (AQI) prediction, and in severely polluted cases (AQI ≥ 300) the accuracy rate of AQI prediction even reaches up to 87.8%. The experiment of one-week prediction shows that our model has excellent sensitivity when a sudden haze burst or dissipation happens, which results in good long-term stability on the accuracy of the next 3–7 days' AQI prediction. PMID:27597861

  7. The Blue Emu

    Science.gov (United States)

    Descalzi, Doug; Gillett, John; Gordon, Carlton; Keener, ED; Novak, Ken; Puente, Laura

    1993-01-01

    The primary goal in designing the Blue Emu was to provide an airline with a cost efficient and profitable means of transporting passengers between the major cities in Aeroworld. The design attacks the market where a demand for inexpensive transportation exists and for this reason the Blue Emu is an attractive investment for any airline. In order to provide a profitable aircraft, special attention was paid to cost and economics. For example, in manufacturing, simplicity was stressed in structural design to reduce construction time and cost. Aerodynamic design employed a tapered wing which reduced the induced drag coefficient while also reducing the weight of the wing. Even the propulsion system was selected with cost effectiveness in mind, yet also to maintain the marketability of the aircraft. Thus, in every aspect of the design, consideration was given to economics and marketability of the final product.

  8. Exploring the severe winter haze in Beijing: the impact of synoptic weather, regional transport and heterogeneous reactions

    Science.gov (United States)

    Zheng, Guangjie; Su, Hang; zhang, qiang; cheng, yafang; he, kebin

    2016-04-01

    Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, we performed a model-assisted analysis of the hourly observation data of PM2.5 and its major chemical compositions. The synthetic analysis shows that, (1) the severe winter haze was driven by stable synoptic meteorological conditions over northeastern China, and not by an abrupt increase in anthropogenic emissions. (2) Secondary species, including organics, sulfate, nitrate, and ammonium, were the major constituents of PM2.5 during this period. (3) Due to the dimming effect of high loading of aerosol particles, gaseous oxidant concentrations decreased significantly, suggesting a reduced production of secondary aerosols through gas phase reactions. Surprisingly, the observational data reveals an enhanced production rate of secondary aerosols, suggesting an important contribution from other formation pathways, most likely heterogeneous reactions. These reactions appeared to be more efficient in producing secondary inorganics aerosols than organic aerosols resulting in a strongly elevated fraction of inorganics during heavily polluted periods. (4) Moreover, we found that high aerosol concentration was a regional phenomenon. The accumulation process of aerosol particles occurred successively from southeast cities to Beijing. The apparent sharp increase in PM2.5 concentration of up to several hundred μg m-3 per hour recorded in Beijing represented rapid recovery from an interruption to the continuous pollution accumulation over the region, rather than purely local chemical production. This suggests that regional transport of pollutants played an important role during these severe pollution events.

  9. Simulations of Sulfate-Nitrate-Ammonium (SNA) aerosols during the extreme haze events over Northern China in 2014

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dan; Liu, Zhiquan; Fast, Jerome D.; Ban, Junmei

    2016-08-30

    Extreme haze events have occurred frequently over China in recent years. Although many studies have investigated the formation mechanisms associated with PM2.5 for heavily polluted regions in China based on observational data, adequately predicting peak PM2.5 concentrations is still challenging for regional air quality models. In this study, we evaluate the performance of one configuration of the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) and use the model to investigate the sensitivity of heterogeneous reactions on simulated peak sulfate, nitrate, and ammonium concentrations in the vicinity of Beijing during four extreme haze episodes in October 2014 over the North China Plain. The highest observed PM2.5 concentration of 469 μg m-3 occurred in Beijing. Comparisons with observations show that the model reproduced the temporal variability in PM2.5 with the highest PM2.5 values on polluted days (defined as days in which observed PM2.5 is greater than 75 μg m-3), but predictions of sulfate, nitrate, and ammonium were too low on days with the highest observed concentrations. Observational data indicate that the sulfur/nitric oxidation rates are strongly correlated with relative humidity during periods of peak PM2.5; however, the model failed to reproduce the highest PM2.5 concentrations due to missing heterogeneous reactions. As the parameterizations of those reactions is not well established yet, estimates of SO2-to-H2SO4 and NO2/NO3-to-HNO3 reaction rates that depend on relative humidity were applied which improved the simulation of sulfate, nitrate, and ammonium enhancement on polluted days in terms of both concentrations and partitioning among those species. Sensitivity simulations showed that the extremely high heterogeneous reaction rates and also higher emission rates than those reported in the emission inventory

  10. Impact of biomass burning on haze pollution in the Yangtze River delta, China: a case study in summer 2011

    Science.gov (United States)

    Cheng, Z.; Wang, S.; Fu, X.; Watson, J. G.; Jiang, J.; Fu, Q.; Chen, C.; Xu, B.; Yu, J.; Chow, J. C.; Hao, J.

    2014-05-01

    Open biomass burning is an important source of air pollution in China and globally. Joint observations of air pollution were conducted in five cities (Shanghai, Hangzhou, Ningbo, Suzhou and Nanjing) of the Yangtze River delta, and a heavy haze episode with visibility 2.9-9.8 km was observed from 28 May to 6 June 2011. The contribution of biomass burning was quantified using both ambient monitoring data and the WRF/CMAQ (Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ)) model simulation. It was found that the average and maximum daily PM2.5 concentrations during the episode were 82 and 144 μgm-3, respectively. Weather pattern analysis indicated that stagnation enhanced the accumulation of air pollutants, while the following precipitation event scavenged the pollution. Mixing depth during the stagnant period was 240-399 m. Estimation based on observation data and CMAQ model simulation indicated that biomass open burning contributed 37% of PM2.5, 70% of organic carbon and 61% of elemental carbon. Satellite-detected fire spots, back-trajectory analysis and air quality model simulation were integrated to identify the locations where the biomass was burned and the pollutants transport. The results suggested that the impact of biomass open burning is regional, due to the substantial inter-province transport of air pollutants. PM2.5 exposure level could be reduced 47% for the YRD region if complete biomass burning is forbidden and significant health benefit is expected. These findings could improve the understanding of heavy haze pollution, and suggest the need to ban open biomass burning during post-harvest seasons.

  11. Synthesizing a Blue Ocean

    OpenAIRE

    Vester, Daniel

    2012-01-01

    The purpose of this Master thesis was to determine how electronic musical instrument companies could utilize innovation strategies to add value to their products and create new business markets beyond their core. The theoretical framework was established by outlining competitive strategies suitable for adoption by electronic musical instrument companies. The Blue Ocean Strategy was compared to traditional competitive strategies such as Porter’s Five Forces, and subsequently chosen because of ...

  12. Suppression of local haze variations in MERIS images over turbid coastal waters for retrieval of suspended sediment concentration

    NARCIS (Netherlands)

    Shen, F.; Verhoef, W.

    2010-01-01

    Atmospheric correction over turbid waters can be problematic if atmospheric haze is spatially variable. In this case the retrieval of water quality is hampered by the fact that haze variations could be partly mistaken for variations in suspended sediment concentration (SSC). In this study we propose

  13. Chemical characteristics and source apportionment of PM10 during a brown haze episode in Harbin,China

    Institute of Scientific and Technical Information of China (English)

    Likun Huang; Chung-Shin Yuan; Guangzhi Wang; Kun Wang

    2011-01-01

    This study investigates the correlation between PM10 and meteorological factors such as wind speed,atmospheric visibility,dew point,relative humidity,and ambient temperature during a brown haze episode. In order to identify the potential sources of PM10 during brown haze episode,respirable particulate matter (PM10) was collected during both non-haze days and haze days and further analyzed for metallic elements,ionic species,and carbonaceous contents. Among them,ionic species contributed 45-64% to PM10,while metallic elements contributed 7-21% to PM10 which was smaller than the other chemical constituents. The average OC/EC ratio (42) in haze days was about three times of the average OC/EC ratio (14) in non-haze days. By using chemical mass balance (CMB) receptor model,the major sources were apportioned,including traffics,incinerators,coal combustion,steel industry,petrochemical industry,and secondary aerosols,etc. The contribution to PM10 concentration of each source was calculated for all the samples collected. The results showed that coal combustion was the major source of PM10 in non-haze days and secondary aerosols were the major source in haze days,followed by petrochemical industry,incinerators,and traffics,while other sources had negligible effect.

  14. The effects of dust–haze on mortality are modified by seasons and individual characteristics in Guangzhou, China

    International Nuclear Information System (INIS)

    This study aimed to investigate the effects of dust–haze on mortality and to estimate the seasonal and individual-specific modification effects in Guangzhou, China. Mortality, air pollution and meteorological data were collected for 2006–2011. A dust–haze day was defined as daily visibility 10. We concluded that dust–haze significantly increased mortality risk in Guangzhou, China, and this effect appears to be dominated by particulate mass and modified by season and individual-specific factors. - Highlights: • We assessed the health impact of dust–haze in a megacity of southern China. • A dust–haze was defined according to visibility and relative humidity. • Dust–haze increased mortality risk, which may be dominated by particulate mass. • The dust–haze effects were modified by season and individual-specific factors. - This study extends our understanding of the health impact of dust–haze in southern China, and provides local evidence for health to advocate for improved air emissions control and strategies to reduce population exposure

  15. Analytical solution for haze values of aluminium-induced texture (AIT) glass superstrates for a-Si:H solar cells.

    Science.gov (United States)

    Sahraei, Nasim; Forberich, Karen; Venkataraj, Selvaraj; Aberle, Armin G; Peters, Marius

    2014-01-13

    Light scattering at randomly textured interfaces is essential to improve the absorption of thin-film silicon solar cells. Aluminium-induced texture (AIT) glass provides suitable scattering for amorphous silicon (a-Si:H) solar cells. The scattering properties of textured surfaces are usually characterised by two properties: the angularly resolved intensity distribution and the haze. However, we find that the commonly used haze equations cannot accurately describe the experimentally observed spectral dependence of the haze of AIT glass. This is particularly the case for surface morphologies with a large rms roughness and small lateral feature sizes. In this paper we present an improved method for haze calculation, based on the power spectral density (PSD) function of the randomly textured surface. To better reproduce the measured haze characteristics, we suggest two improvements: i) inclusion of the average lateral feature size of the textured surface into the haze calculation, and ii) considering the opening angle of the haze measurement. We show that with these two improvements an accurate prediction of the haze of AIT glass is possible. Furthermore, we use the new equation to define optimum morphology parameters for AIT glass to be used for a-Si:H solar cell applications. The autocorrelation length is identified as the critical parameter. For the investigated a-Si:H solar cells, the optimum autocorrelation length is shown to be 320 nm. PMID:24922000

  16. What Causes Haze Pollution? An Empirical Study of PM2.5 Concentrations in Chinese Cities

    Directory of Open Access Journals (Sweden)

    Jiannan Wu

    2016-01-01

    Full Text Available In recent years, many areas of China have suffered from serious haze pollution, which greatly affects human health and daily life. It is of policy importance to understand the factors that influence the spatial concentration of PM2.5. Based on data from 74 cities with PM2.5 monitoring stations in 2013 and 2014, this study presents the overall haze situation in China and explores the determinants of PM2.5 using a random-effects model, as well as a set of OLS regressions. The results indicate that PM2.5 is significantly correlated with the industrial proportion, the number of motor vehicles, and household gas consumption, while public financial expenditure on energy saving and environmental protection does not show statistically significant effects. The analysis implies that China should adjust its economic structure and optimizes environmental governance to effectively respond to haze pollution.

  17. Predicting Intention to Take Protective Measures During Haze: The Roles of Efficacy, Threat, Media Trust, and Affective Attitude.

    Science.gov (United States)

    Lin, Trisha T C; Bautista, John Robert

    2016-07-01

    The annual Southeast Asian haze pollution raises public health concerns in this region. Based on a modified extended parallel process model, this study examines efficacy (self-efficacy and response efficacy) and perceived threat (susceptibility and severity) and incorporates new constructs of media trust and affective attitude. Results from a Web survey of 410 undergraduate students in Singapore show that response efficacy to seek haze-related information mediates the association between perceived self-efficacy and intention to take protective measures during haze. Moreover, self-efficacy is negatively associated with affective attitude (e.g., fear and worry) toward haze-related health problems. Next, perceived severity and perceived susceptibility are positively associated with response efficacy and affective attitude. Affective attitude toward haze is a stronger predictor than response efficacy for behavioral intention. Finally, trust in new media is positively associated with young Singaporeans' affective attitude, which positively affects their behavioral intention to take protective measures. PMID:27315440

  18. Assessing the Performance of the Photovoltaic Cells on the Effects of Yellow Dust Events and Haze in Seoul, Korea

    Science.gov (United States)

    Choi, Jiyeon; Kim, Yong Pyo; Wee, DaeHyun

    2016-04-01

    We analyze the potential effects of the Asian yellow dust Events and haze on the performance of Korean photovoltaic systems. Particulate matters from the Asian yellow dust outbreaks in the deserts of Mongolia and northern China are typically transported to Korea. Haze is an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky. Hence, we conjecture that the effects of the Asian yellow dust and haze block the incident solar irradiance. The potential reduction of the solar spectral irradiance due to Asian yellow dust events and haze in Korea is investigated using a clear-sky spectral radiation model, and the performance of photovoltaic systems under reduced irradiance is estimated by using a simple analytic model representing typical photovoltaic cells. Comparison of photovoltaic performance under Asian dust events, haze and that under a clear condition is made to evaluate overall influence of the particulate air pollution, respectively.

  19. The Composition of Organic Aerosols in Southeast Asia During The 2006 Haze Episode

    Science.gov (United States)

    Jun, H.; Zielinska, B.; Balasubramanian, R.

    2007-12-01

    The regional smoke haze in Southeast Asia is a recurring air pollution problem. Uncontrolled forest fires from land-clearing activities in Sumatra and Borneo, and to a lesser extent Malaysia, have occurred almost every dry season since the late 1990s. The smoke haze that took place in October 2006 shrouded an estimated 215,000 square miles of land on Indonesia's islands of Sumatra and Borneo, and persisted for several weeks. Satellite pictures showed numerous hotspots in both Sumatra and Kalimantan. The prevailing, South-Southwesterly, winds blew smoke from land and forest fires in central and south Sumatra to Singapore, affecting the regional air quality significantly and reducing atmospheric visibility. During this haze episode, we carried out an intensive field study in Singapore to characterize the composition of organic aerosols, which usually account for a large fraction of airborne particulate matter (PM). A total of 17 PM samples were collected while the hazy atmospheric conditions persisted in Singapore, and subjected to accelerated solvent extraction with dichloromethane and acetone. The extracted compounds were grouped into three major fractions (n-alkanes, polycyclic aromatic hydrocarbons, and polar organic compounds). More than 180 particulate-bound organic compounds were determined using gas chromatography/mass spectrometry (GC-MS). In order to investigate the origin of organic species, the carbon preference indexes as well as diagnostic ratios were used. The compositional differences of organic aerosols between the haze- and non- haze periods will be presented. The atmospheric implications of the composition of organic aerosols of biomass burning origin will be discussed. Keywords: smoke haze, organic aerosols, n-alkanes, polycyclic aromatic hydrocarbons, polar organic compounds

  20. Blue nano titania made in diffusion flames.

    Science.gov (United States)

    Teleki, Alexandra; Pratsinis, Sotiris E

    2009-05-21

    Blue titanium suboxide nanoparticles (including Magneli phases) were formed directly without any post-processing or addition of dopants by combustion of titanium-tetra-isopropoxide (TTIP) vapor at atmospheric pressure. Particle size, phase composition, rutile and anatase crystal sizes as well as the blue coloration were controlled by rapid quenching of the flame with a critical flow nozzle placed at various heights above the burner. The particles showed a broad absorption in the near-infrared region and retained their blue color upon storage in ambient atmosphere. A high concentration of paramagnetic Ti3+ centres was found in the substoichiometric particles by electron paramagnetic resonance (EPR) spectroscopy. Furthermore particles with controlled band gap energy from 3.2 to 3.6 eV were made by controlling the burner-nozzle-distance from 10 to 1 cm, respectively. The color robustness and extent of suboxidation could be further enhanced by co-oxidation of TTIP with hexamethyldisiloxane in the flame resulting in SiO2-coated titanium suboxide particles. The process is cost-effective and green while the particles produced can replace traditional blue colored, cobalt-containing pigments. PMID:19421486

  1. The Importance of Ammonia for Winter Haze Formation in Two Oil and Gas Production Regions

    Science.gov (United States)

    Collett, J. L., Jr.; Li, Y.; Evanoski-Cole, A. R.; Sullivan, A.; Day, D.; Archuleta, C.; Tigges, M.; Sewell, H. J.; Prenni, A. J.; Schichtel, B. A.

    2014-12-01

    Fine particle ammonium nitrate formation results from the atmospheric reaction of gaseous ammonia and nitric acid. This reaction is most important in winter when low temperatures thermodynamically enhance particle formation. Nitrogen oxides emissions from oil and gas operations partially react in the atmosphere to form nitric acid. The availability of atmospheric ammonia plays an important role in determining whether the nitric acid formed results in wintertime ammonium nitrate formation. Here we contrast situations in two important U.S. oil and gas production regions. Measurements of ammonia, nitric acid, ammonium nitrate and other species were made from 2007 to present near Boulder, Wyoming and in winters 2013 and 2014 in western North Dakota. The Boulder, Wyoming site is close to the large Jonah and Pinedale Anticline gas fields. Field sites at the north unit of Theodore Roosevelt National Park and Fort Union are situated in the large Bakken Formation oil and gas production region. Wintertime formation of nitric acid and ammonium nitrate, together comprising nitrogen in the +5 oxidation state (N(V)), was observed in both locations. Concentrations of N(V), however, are generally much lower at Boulder, WY than in the Bakken. An even bigger difference is seen in fine particle ammonium nitrate concentrations; limited regional ammonia is available in western Wyoming to react with nitric acid, leaving a portion of the nitric acid trapped in the gas phase. Higher concentrations of ammonia are observed in the Bakken where they support formation of much higher concentrations of ammonium nitrate. Comparison of these two regions clearly indicates the importance of understanding both local NOx emissions and regional concentrations of ammonia in predicting source impacts on formation of fine particles and haze.

  2. Our Blue Gene Experience

    Czech Academy of Sciences Publication Activity Database

    Jakl, Ondřej; Starý, Jiří

    Ostrava : Ústav geoniky AV ČR, 2009 - (Blaheta, R.; Starý, J.), s. 50-54 ISBN 978-80-86407-60-9. [SNA '09 - Seminar on numerical analysis: modelling and simulation of challenging engineering problems. Ostrava (CZ), 02.02.2009-06.02.2009] R&D Projects: GA ČR(CZ) GA105/09/1830 Institutional research plan: CEZ:AV0Z30860518 Keywords : IBM Blue Gene/P * finite element solver * parallel scalability Subject RIV: BA - General Mathematics

  3. Estruturas fundamentais no blues

    OpenAIRE

    Silva, Rafael Palmeira da

    2012-01-01

    Resumo: Esta pesquisa tem como objeto de estudo a aplicação e adaptação da teoria de Schenker como ferramenta analítica aplicada ao jazz, tendo em vista a possibilidade de encontrar estruturas fundamentais distintas na música popular. Tendo como base as análises feitas por Larson (1998; 2009), Forte (2011) e Stock (1993) a pesquisa abordará, em um primeiro momento, as origens do jazz (blues e ragtime) como parte essencial para sua abordagem analítica, através da ótica etno-schenkeriana propos...

  4. Identification of chemical compositions and sources of atmospheric aerosols in Xi'an, inland China during two types of haze events.

    Science.gov (United States)

    Li, Jianjun; Wang, Gehui; Ren, Yanqin; Wang, Jiayuan; Wu, Can; Han, Yanni; Zhang, Lu; Cheng, Chunlei; Meng, Jingjing

    2016-10-01

    High time resolution (1h) of TSP filter samples was collected in Xi'an in inland China from December 5 to 13, 2012, during which a 9-day long of haze episode occurred. The hazy days were classified as two types, i.e., Light-haze period with moderate degradation in visibility (5-10km) and relatively dry conditions (RH: 53±19%) and Severe-haze period with a daily visibility less than 5km and humid conditions (RH: 73±14%). TSP in the two periods (415±205 and 530±180μgm(-3) in Light-haze and Severe-haze periods, respectively) was comparable, but crustal Fe and Ca elements presented higher concentrations and strong correlation (R(2)=0.72) with TSP in Light-haze period. SO4(2-), NO3(-) and NH4(+) in Light-haze period were 16±5.9, 12±6.7 and 4.1±2.8μgm(-3), respectively, and increased dramatically to 51±15, 44±9.7 and 23±5.6μgm(-3) in Severe-haze period. Contributions of Fe and Ca to TSP decreased from 9.2% in Light-haze period to 5.3% in Severe-haze period, but those of SO4(2-), NO3(-) and NH4(+) increased from 3.8%, 2.9% and 1.0% in Light-haze period to 9.6%, 8.3% and 4.4% in Severe-haze period, respectively. These results suggest that dust-derived particles were more significant in Light-haze period while secondary aerosols were more important in Severe-haze period. Hopanes (33±24 and 38±29ngm(-3) in Light-haze and Severe-haze periods, respectively) during the two types of haze periods are comparable, indicating that differences in contribution of primary organic aerosols from fossil fuel combustions to TSP were insignificant. In contrast, the ratio of secondary organic aerosols (e.g., o-phthalic acid) to EC was much higher in Severe-haze period (5.8±2.7ngμg(-1)) than in Light-haze period (3.4±2.1ngμg(-1)), probably indicating that the humid conditions in Severe-haze period are favorable for secondary organic aerosol formation. PMID:27220100

  5. Comparison of composition of PM2.5 between haze and non-haze periods from 2012.3 to 2013.2 in Beijing

    Science.gov (United States)

    Fang, Y.; Zhu, T.; Wang, J.

    2014-12-01

    Fine particles (PM2.5) are complex compounds which are related to adverse health effects, visibility degradation and global climate change. A number of studies have focused on the components, sources and transportation of PM2.5all over the world. As the capital of China,suffering from the dense population and heavy traffic, Beijing has experienced serious air pollution, which can be easily proved by the increasing number of low-visibility days. In this study, we collected the daily PM2.5 samples from 2012.3 to 2013.2 to get the continuous data. The components of PM2.5 including ions, EC/OC and trace elements were obtained. Sulfate, nitrate, ammonium and organic matters (OM) are major components which account for more than 50% of PM2.5. Clearly seasonal variations are observed. Trace elements are highest in spring and lowest in summer. OM in winter is almost 3 times higher than that in summer. The percentage of OM has a significantly negative correlation with PM2.5 in summer and has no correlation with PM2.5 in winter at the p = 0.05 level, while indicates that in summer, the formation of organic compound may less important than in winter. The differences between seasons when haze episode occurred and the changes between haze and non-haze period will be discussed.

  6. REMOTE SENSING MEASUREMENTS OF AEROSOL OPTICAL THICKNESS AND CORRELATION WITH IN-SITU AIR QUALITY PARAMETERS DURING A SMOKE HAZE EPISODE IN SOUTHEAST ASIA

    Science.gov (United States)

    Chew, B.; Salinas Cortijo, S. V.; Liew, S.

    2009-12-01

    Transboundary smoke haze due to biomass burning is a major environmental problem in Southeast Asia which has not only affected air quality in the source region, but also in the surrounding countries. Air quality monitoring stations and meteorological stations can provide valuable information on the concentrations of criteria pollutants such as sulphur dioxide, nitrogen oxide, carbon monoxide, ozone and particulate mass (PM10) as well as health advisory to the general public during the haze episodes. Characteristics of aerosol particles in the smoke haze such as the aerosol optical thickness (AOT), aerosol size distribution and Angstrom exponent are also measured or retrieved by sun-tracking photometers, such as those deployed in the world-wide AErosol RObotic NETwork (AERONET). However, due to the limited spatial coverage by the air quality monitoring stations and AERONET sites, it is difficult to study and monitor the spatial and temporal variability of the smoke haze during a biomass burning episode, especially in areas without ground-based instrumentation. As such, we combine the standard in-situ measurements of PM10 by air quality monitoring stations with the remote sensing imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra and Aqua satellites. The columnar AOT is first derived from the MODIS images for regions where PM10 measurements are available. Empirical correlations between AOT and PM10 measurements are then established for 50 sites in both Malaysia and Singapore during the smoke haze episode in 2006. When available, vertical feature information from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) is used to examine the validity of the correlations. Aloft transport of aerosols, which can weaken the correlations between AOT and PM10 measurements, is also identified by CALIPSO and taken into consideration for the analysis. With this integrated approach, we hope to enhance and

  7. Blue emitting undecaplatinum clusters

    Science.gov (United States)

    Chakraborty, Indranath; Bhuin, Radha Gobinda; Bhat, Shridevi; Pradeep, T.

    2014-07-01

    A blue luminescent 11-atom platinum cluster showing step-like optical features and the absence of plasmon absorption was synthesized. The cluster was purified using high performance liquid chromatography (HPLC). Electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry (MS) suggest a composition, Pt11(BBS)8, which was confirmed by a range of other experimental tools. The cluster is highly stable and compatible with many organic solvents.A blue luminescent 11-atom platinum cluster showing step-like optical features and the absence of plasmon absorption was synthesized. The cluster was purified using high performance liquid chromatography (HPLC). Electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry (MS) suggest a composition, Pt11(BBS)8, which was confirmed by a range of other experimental tools. The cluster is highly stable and compatible with many organic solvents. Electronic supplementary information (ESI) available: Details of experimental procedures, instrumentation, chromatogram of the crude cluster; SEM/EDAX, DLS, PXRD, TEM, FT-IR, and XPS of the isolated Pt11 cluster; UV/Vis, MALDI MS and SEM/EDAX of isolated 2 and 3; and 195Pt NMR of the K2PtCl6 standard. See DOI: 10.1039/c4nr02778g

  8. Blue ocean leadership.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2014-05-01

    Ten years ago, two INSEAD professors broke ground by introducing "blue ocean strategy," a new model for discovering uncontested markets that are ripe for growth. In this article, they apply their concepts and tools to what is perhaps the greatest challenge of leadership: closing the gulf between the potential and the realized talent and energy of employees. Research indicates that this gulf is vast: According to Gallup, 70% of workers are disengaged from their jobs. If companies could find a way to convert them into engaged employees, the results could be transformative. The trouble is, managers lack a clear understanding of what changes they could make to bring out the best in everyone. Here, Kim and Mauborgne offer a solution to that problem: a systematic approach to uncovering, at each level of the organization, which leadership acts and activities will inspire employees to give their all, and a process for getting managers throughout the company to start doing them. Blue ocean leadership works because the managers' "customers"-that is, the people managers oversee and report to-are involved in identifying what's effective and what isn't. Moreover, the approach doesn't require leaders to alter who they are, just to undertake a different set of tasks. And that kind of change is much easier to implement and track than changes to values and mind-sets. PMID:24956870

  9. Blue tits are ultraviolet tits

    OpenAIRE

    Hunt, S; Bennett, A.T.D.; Cuthill, I. C.; Griffiths, R.

    1998-01-01

    The blue tit (Parus caeruleus) has been classified as sexually monochromatic. This classification is based on human colour perception yet, unlike humans, most birds have four spectrally distinct classes of cone and are visually sensitive to wavelengths in the near-ultraviolet (300 to 400 nm). Reflectance spectrophotometry reveals that blue tit plumage shows considerable reflection of UV light. For example, the blue crest shows peak reflectance at wavelengths around 352 nm. Furthermore, the bl...

  10. Postpartum Blues and Postpartum Depression

    OpenAIRE

    Erdem Ö et al.

    2009-01-01

    Postpartum blues which is seen during the postpartum period is a transient psychological state. Most of the mothers experience maternity blues in postpartum period. It remains usually unrecognized by the others. Some sensitive families can misattribute these feelings as depression. In this article, we tried to review the characteristics of maternity blues and its differences from depression. We defined depression and presented the incidence and diagnostic criteria, of major depression as well...

  11. Modeling study of the 2010 regional haze event in the North China Plain

    Science.gov (United States)

    Gao, M.; Carmichael, G. R.; Wang, Y.; Saide, P. E.; Yu, M.; Xin, J.; Liu, Z.; Wang, Z.

    2016-02-01

    The online coupled Weather Research and Forecasting-Chemistry (WRF-Chem) model was applied to simulate a haze event that happened in January 2010 in the North China Plain (NCP), and was validated against various types of measurements. The evaluations indicate that WRF-Chem provides reliable simulations for the 2010 haze event in the NCP. This haze event was mainly caused by high emissions of air pollutants in the NCP and stable weather conditions in winter. Secondary inorganic aerosols also played an important role and cloud chemistry had important contributions. Air pollutants outside Beijing contributed about 64.5 % to the PM2.5 levels in Beijing during this haze event, and most of them are from south Hebei, Tianjin city, Shandong and Henan provinces. In addition, aerosol feedback has important impacts on surface temperature, relative humidity (RH) and wind speeds, and these meteorological variables affect aerosol distribution and formation in turn. In Shijiazhuang, Planetary Boundary Layer (PBL) decreased about 278.2 m and PM2.5 increased more than 20 µg m-3 due to aerosol feedback. It was also shown that black carbon (BC) absorption has significant impacts on meteorology and air quality changes, indicating more attention should be paid to BC from both air pollution control and climate change perspectives.

  12. 78 FR 57487 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Regional Haze

    Science.gov (United States)

    2013-09-19

    ... relies''), 70 FR 39104, 39143 (``The baseline date for regional haze SIPs is 2002. . . .'') & id. n.84... published a Notice of Proposed Rulemaking (NPR) for the State of Massachusetts. See 77 FR 30932. The NPR... upheld in Utility Air Regulatory Group v. EPA, 471 F.3d 1333 (D.C. Cir. 2006). See 77 FR 33642,...

  13. 77 FR 38006 - Approval and Promulgation of Implementation Plans; State of Iowa: Regional Haze

    Science.gov (United States)

    2012-06-26

    ... Regional Haze SIP and imposed a FIP for Iowa. 77 FR 33642. V. Statutory and Executive Order Requirements... Executive Order Reviews I. Background On February 28, 2012 (77 FR 11974), EPA published a notice of proposed... Executive Order 12866 (58 FR 51735, October 4, 1993); Does not impose an information collection burden...

  14. 77 FR 31240 - Approval and Promulgation of Air Quality Implementation Plans; State of Florida; Regional Haze...

    Science.gov (United States)

    2012-05-25

    ... haze on July 1, 1999 (64 FR 35713), the RHR. The RHR revised the existing visibility regulations to... 76 FR 82219 (December 30, 2011). EPA is not proposing to take action in today's rulemaking on issues... natural conditions. See 64 FR 35715 (July 1, 1999). \\5\\ Visual range is the greatest distance,...

  15. Progress towards a post-Venus Express Clouds & Haze reference model for Venus

    Science.gov (United States)

    Marcq, Emmanuel; Belyaev, Denis; Wilson, Colin; Wilquet, Valérie; Luginin, Mikhail

    2016-07-01

    With the end of Venus Express in 2014, the focus of the scientific community has gradually moved from the study of Venus Express mono-instrumental data sets to cross-instrumental studies involving pure modelization as well. This is especially true for the clouds and hazes that surround most of the planet between 48 and 70 km. They play a major role at the crossroads of various atmospheric processes among which the radiative budget as well as the dynamical and chemical coupling between the lower and upper atmosphere. In order to support such efforts, ISSI has supported from 2013 to 2015 a "Clouds & Hazes of Venus" scientific team involving Venus Express and ground-based observers as well as microphysical modelers. Together, they compared their results in order to achieve a more unified and consistent view of Venus' clouds and hazes, taking into account its spatial and temporal variability more in detail than previously available VIRA-1 and 2 cloud models. We will review the individual data sets and models that have been used, and then present our strategy towards a unified cloud model. We will first make available some observable parameters to the wider community through a web-based repository. Our future steps will involve more advanced techniques (data assimilation) in order to achieve our objective of a unified Venus clouds & haze model that encompasses its various variabilities as well as possible.

  16. 77 FR 46952 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Regional Haze

    Science.gov (United States)

    2012-08-07

    ..., 1999 (64 FR 35713), and subsequently amended on July 6, 2005 (70 FR 39156), and on October 16, 2006 (70 FR 60631). The July 6, 2005, amendment provides further guidance on provisions related to BART. EPA proposed approval of the Wisconsin regional haze plan on February 28, 2012 (77 FR 11928). The proposed...

  17. 77 FR 71533 - Approval and Promulgation of Air Quality Implementation Plans; Michigan; Regional Haze State...

    Science.gov (United States)

    2012-12-03

    ... Regional Haze Rule was promulgated on July 1, 1999 (64 FR 35713), with further significant provisions promulgated on July 6, 2005 (70 FR 39104), that provided guidance related to BART. On August 6, 2012 (77 FR... Michigan and a number of other states in a separate rulemaking, published on June 7, 2012 (77 FR...

  18. 77 FR 11937 - Approval and Promulgation of Air Quality Implementation Plans; State of Alabama; Regional Haze...

    Science.gov (United States)

    2012-02-28

    ... submittal arising from the State's reliance on CAIR to meet certain regional haze requirements. See 76 FR... in 40 CFR 52.61 that were approved into the Alabama SIP. See 52 FR 45138 (November 24, 1987). EPA is... 64 FR 35715 (July 1, 1999). \\3\\ Visual range is the greatest distance, in kilometers or miles,...

  19. Effect of Homoharringtonine on Corneal Haze after Excimer Laser Photorefractive Keratectomy in Rabbits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Mingchang; WANG Li; WANG Yong; DING Zhengping; MAI Caikeng; NIE Shaosong; CHEN Fei

    2005-01-01

    To evaluate the inhibiting effect of Homoharringtonine HHT) on the corneal haze after excimer laser photorefractive keratectomy (PRK) in rabbits. 18 healthy rabbits which underwent PRK were randomly divided into three groups (A, B and C). The refractive degree of ablation was -10. 0DS in each group. Group A was locally treated with a piece of filter paper soaked with 1 mg/mi HHT for 5 min, and then the entire cornea was repeatedly irrigated with balance solution;Group B was dropped with 0.1 mg/mL HHT after PRK for 3 months; Group C was the control group. Corneal haze, histopathology, response, ect. were investigated. The corneal haze was sig nificantly less in group A, while the difference between group B and group C was insignificant.Keratocytes and fibrocytes in corneal stroma were more active up to 3 months in group B and group C. Intraoperative use of topical HHT can reduce corneal haze after PRK in rabbits.

  20. 77 FR 35287 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Regional Haze State...

    Science.gov (United States)

    2012-06-13

    ... Haze Rule (RH rule) (64 FR 35732, July 1, 1999) and the rationale for EPA's proposed action are...,'' or ``our'' is used, we mean EPA. On January 25, 2012 (77 FR 3691), EPA published a notice of proposed... Virginia). (76 FR 82219, December 30, 2011). Given the significance of the emissions reductions from...

  1. 78 FR 10546 - Approval and Promulgation of Implementation Plans; State of Alaska; Regional Haze State...

    Science.gov (United States)

    2013-02-14

    ... 1. 77 FR 11034, February 24, 2012. The Regional Haze rule grants States the authority to make the... toward improving visibility in mandatory Class I Federal areas \\1\\ (Class I areas). 64 FR 35714 (July 1, 1999); see also 70 FR 39104 (July 6, 2005) and 71 FR 60612 (October 13, 2006). \\1\\ Areas designated...

  2. 77 FR 34218 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Regional Haze

    Science.gov (United States)

    2012-06-11

    ... SIP.' The baseline date for regional haze SIPs is 2002 * * *'' 70 FR 39143. Comment #2: For the Alcoa... CFR 51.308. This rule was promulgated on July 1, 1999 (64 FR 35713). Further significant provisions... proposed a limited approval of Indiana's submittal on January 26, 2012 (77 FR 3975). That action...

  3. 78 FR 16452 - Approval and Promulgation of Implementation Plans; North Dakota; Regional Haze State...

    Science.gov (United States)

    2013-03-15

    ... discussion of regional haze requirements, please see our proposal at 76 FR 58574, 58576. In our proposed action, we proposed to disapprove the State's NO X BART determinations for these units. See 76 FR 58570... BART determinations for these units. 77 FR 20894, 20897 (April 6, 2012). We based our change on...

  4. 77 FR 3712 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Regional Haze

    Science.gov (United States)

    2012-01-25

    ... the regional haze program. 70 FR 39104 (July 6, 2005). EPA's regulations provided that states... natural conditions. See 64 FR 35715 (July 1, 1999). \\1\\ Areas designated as mandatory Class I Federal..., promulgated a list of 156 areas where visibility is identified as an important value. 44 FR 69122 (November...

  5. 77 FR 3966 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Regional Haze

    Science.gov (United States)

    2012-01-26

    ... promulgated the Regional Haze Rule (RHR) on July 1, 1999 (64 FR 35713). The RHR revised the existing...-fifth of the visual range that would exist under estimated natural conditions. 64 FR 35715 (July 1, 1999... is identified as an important value. 44 FR 69122 (November 30, 1979). The extent of a mandatory...

  6. 77 FR 73369 - Approval and Promulgation of Air Quality Implementation Plans; State of Florida; Regional Haze...

    Science.gov (United States)

    2012-12-10

    ... CAIR to meet certain regional haze requirements. See 76 FR 82219 (December 30, 2011). On May 25, 2012... first implementation period. See 77 FR 31240. EPA's May 25, 2012, proposed rulemaking covered Florida's... sources. On November 29, 2012 (77 FR 71111), EPA took final action fully approving the unit-specific...

  7. Aspartic Acid Protease from Botrytis cinerea Removes Haze-Forming Proteins during White Winemaking

    NARCIS (Netherlands)

    Sluyter, Van S.C.; Warnock, N.I.; Schmidt, S.; Anderson, P.; Kan, van J.A.L.; Bacic, A.; Waters, E.J.

    2013-01-01

    White wines suffer from heat-induced protein hazes during transport and storage unless the proteins are removed prior to bottling. Bentonite fining is by far the most commonly used method, but it is inefficient and creates several other process challenges. An alternative to bentonite is the enzymati

  8. 77 FR 31691 - Approval and Promulgation of Implementation Plans; State of Hawaii; Regional Haze Federal...

    Science.gov (United States)

    2012-05-29

    ... promulgated a rule to address regional haze on July 1, 1999. 64 FR 35714 (July 1, 1999), codified at 40 CFR... deadline identified. F. Public Hearings As announced on May 11, 2012, 77 FR 27671, EPA will hold two public... natural conditions. 64 FR 35715 (July 1, 1999). \\1\\ Visual range is the greatest distance, in...

  9. 76 FR 41158 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Regional Haze State...

    Science.gov (United States)

    2011-07-13

    .... EPA promulgated a rule to address regional haze on July 1, 1999 (64 FR 35713), the RHR. The RHR... FR 39104, 39142-4143, July 6, 2005). CAIR, as originally promulgated, requires significant reductions.... (75 FR 45210, Aug. 2, 2010) (``the Transport Rule''). EPA explained in that proposal that...

  10. 78 FR 34737 - Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze...

    Science.gov (United States)

    2013-06-10

    ... regional haze on July 1, 1999. 64 FR 35714 (July 1, 1999), codified at 40 CFR part 51, subpart P. The RHR..., 2012, and it was published in the Federal Register on June 4, 2012 (77 FR 33022). In our proposal, we... natural conditions. 64 FR 35715 (July 1, 1999). \\2\\ Visual range is the greatest distance, in...

  11. 77 FR 3681 - Approval and Promulgation of Air Quality Implementation Plans; Minnesota; Regional Haze

    Science.gov (United States)

    2012-01-25

    ... CAIR under regulations issued in 2005 revising the regional haze program. 70 FR 39104 (July 6, 2005... would exist under estimated natural conditions. See 64 FR 35715 (July 1, 1999). \\1\\ Areas designated as... important value. 44 FR 69122 (November 30, 1979). The extent of a mandatory Class I area includes...

  12. 77 FR 11827 - Approval and Promulgation of Air Quality Implementation Plans; State of Maryland; Regional Haze...

    Science.gov (United States)

    2012-02-28

    ... promulgated a rule to address regional haze on July 1, 1999 (64 FR 35714), the RHR. The RHR revised the... under estimated natural conditions (64 FR 35714, July 1, 1999). \\1\\ Visual range is the greatest... visibility impairment'' (45 FR 80084). These regulations represented the first phase in addressing...

  13. EVALUATION OF EFFECTS OF FOREST-FIRE SMOKE/HAZE ON BASIN-WIDE STREAM TEMPERATURES

    Science.gov (United States)

    The effects of forest fires on ecological resources in the area experiencing the burn are well documented in the literature. What is not well known is the effect of smoke and haze generated from forest fires on ecological resources adjacent to or at great distances from the burn ...

  14. Effect of onion extract on corneal haze suppression after air assisted lamellar keratectomy.

    Science.gov (United States)

    Kim, Soohyun; Park, Young Woo; Lee, Euiri; Park, Sang Wan; Park, Sungwon; Noh, Hyunwoo; Kim, Jong Whi; Seong, Je Kyung; Seo, Kangmoon

    2016-04-01

    This study evaluated the effect of onion extract on corneal haze suppression after applying the air assisted lamellar keratectomy. The air assisted lamellar keratectomy was performed on 24 canine eyes. They were treated with an artificial tear (group C), prednisolone acetate (group P), onion extract (group O) and TGF-β1 (group T) three times per day from 7 to 28 days after the surgery. Corneal haze occurred on the all eyes and was observed beginning 7 days after the surgery. The haze was significantly decreased in groups P and O from day 14 compared with the group C using the clinical (group P; P=0.021, group O; P=0.037) and objective evaluation method (group P; P=0.021, group O; P=0.039). In contrast, it was significantly increased in group T from day 14 compared with group C based on the clinical (P=0.002) and objective evaluation method (Peuthanasia, and immunohistochemistry with α-SMA antibodies was done. The total green intensity for α-SMA was significantly more expressed in group T and significantly less expressed in groups P and O than in group C. Onion extract could have potential as a therapeutic in preventing corneal haze development by suppressing the differentiation of fibroblasts into myofibroblasts. PMID:26607134

  15. The Link between Knowledge, Attitudes and Practices in Relation to Atmospheric Haze Pollution in Peninsular Malaysia

    Science.gov (United States)

    De Pretto, Laura; Acreman, Stephen; Ashfold, Matthew J.; Mohankumar, Suresh K.; Campos-Arceiz, Ahimsa

    2015-01-01

    Transboundary haze episodes caused by seasonal forest fires have become a recurrent phenomenon in Southeast Asia, with serious environmental, economic, and public health implications. Here we present a cross-sectional survey conducted among people in Kuala Lumpur and surrounds to assess the links between knowledge, attitudes, and practices in relation to the transboundary haze episodes. Of 305 respondents, 125 were amateur athletes participating in a duathlon event and the remainder were surveyed in an inner-city shopping mall. Across the whole sample, people who possessed more factual information about the haze phenomenon showed significantly higher levels of concern. Duathletes were more knowledgeable than non-duathletes and also more concerned about the negative effects of haze, especially on health. For all people who regularly practice outdoor sports (including people interviewed at the shopping mall), higher levels of knowledge and concerned attitudes translated into a greater likelihood of engaging in protective practices, such as cancelling their outdoor training sessions, while those with greater knowledge were more likely to check the relevant air pollution index on a daily basis. Our results indicate that the provision of accurate and timely information about air quality to residents will translate into beneficial practices, at least among particularly exposed individuals, such as amateur athletes who regularly practice outdoor sports. PMID:26646896

  16. Modeling study of the 2010 regional haze event in the North China Plain

    Directory of Open Access Journals (Sweden)

    M. Gao

    2015-08-01

    Full Text Available The online coupled Weather Research and Forecasting-Chemistry (WRF-Chem model was applied to simulate a haze event that happened in January 2010 in the North China Plain (NCP, and was validated against various types of measurements. The evaluations indicate that WRF-Chem provides reliable simulations for the 2010 haze event in the NCP. This haze event is mainly caused by high emissions of air pollutants in the NCP and stable weather conditions in winter. Secondary inorganic aerosols also played an important role and cloud chemistry had important contributions. Air pollutants outside Beijing contributed about 47.8 % to the PM2.5 levels in Beijing during this haze event, and most of them are from south Hebei, Shandong and Henan provinces. In addition, aerosol feedback has important impacts on surface temperature, Relative Humidity (RH and wind speeds, and these meteorological variables affect aerosol distribution and formation in turn. In Shijiazhuang, Planetary Boundary Layer (PBL decreased about 300 m and PM2.5 increased more than 20 μg m-3 due to aerosol feedback. Feedbacks associated to Black Carbon (BC account for about 50 % of the PM2.5 increases and 50 % of the PBL decreases in Shijiazhuang, indicating more attention should be paid to BC from both air pollution control and climate change perspectives.

  17. 76 FR 38997 - Approval and Promulgation of Implementation Plans; State of Oregon; Regional Haze State...

    Science.gov (United States)

    2011-07-05

    ..., EPA's ``Air Pollution Control Technology Fact Sheet'' states that ``SO 2 removal efficiencies are... that the proposed control limit of 0.4 lb/mmBtu is below the range cited in this fact sheet, but given... air pollution generated by the facility, including air pollutants which contribute to haze in Class...

  18. Archean Earth Atmosphere Fractal Haze Aggregates: Light Scattering Calculations and the Faint Young Sun Paradox

    Science.gov (United States)

    Boness, D. A.; Terrell-Martinez, B.

    2010-12-01

    As part of an ongoing undergraduate research project of light scattering calculations involving fractal carbonaceous soot aggregates relevant to current anthropogenic and natural sources in Earth's atmosphere, we have read with interest a recent paper [E.T. Wolf and O.B Toon,Science 328, 1266 (2010)] claiming that the Faint Young Sun paradox discussed four decades ago by Carl Sagan and others can be resolved without invoking heavy CO2 concentrations as a greenhouse gas warming the early Earth enough to sustain liquid water and hence allow the origin of life. Wolf and Toon report that a Titan-like Archean Earth haze, with a fractal haze aggregate nature due to nitrogen-methane photochemistry at high altitudes, should block enough UV light to protect the warming greenhouse gas NH3 while allowing enough visible light to reach the surface of the Earth. To test this hypothesis, we have employed a rigorous T-Matrix arbitrary-particle light scattering technique, to avoid the simplifications inherent in Mie-sphere scattering, on haze fractal aggregates at UV and visible wavelenths of incident light. We generate these model aggregates using diffusion-limited cluster aggregation (DLCA) algorithms, which much more closely fit actual haze fractal aggregates than do diffusion-limited aggregation (DLA) algorithms.

  19. Haze event monitoring and investigation in Penang Island, Malaysia using a ground-based backscatter Lidar

    International Nuclear Information System (INIS)

    During 24th July 2013 to 1st August 2013, a haze event struck Penang Island, causing the visibility to decrease and increase in Air Pollution Index (API). A ground-based backscatter Lidar, operate at 355 nm which was setup at the roof top of the School of Physics, Universiti Sains Malaysia. It was used to monitor and investigate the haze event. For this work, we studied the daytime variation of the aerosol intensity, distribution, planetary boundary layer (PBL) height and the aerosol optical depth (AOD) values during these days. We found that the aerosol are very intense during the first two days of the haze event and slowly decline as time passed. Finally the haze event died off on 1st August 2013. As for daily aerosol distribution, aerosols are generally more intense during the afternoon. Its intensity is slightly lower in the morning and evening. Similar trends were observed for AOD values as they increase from morning to afternoon and slowly decrease in the evening. Most aerosols are found contained below the PBL which generally found at around 1000 – 2000 m in height

  20. Redefining the importance of nitrate during haze pollution to help optimize an emission control strategy

    Science.gov (United States)

    Pan, Yuepeng; Wang, Yuesi; Zhang, Junke; Liu, Zirui; Wang, Lili; Tian, Shili; Tang, Guiqian; Gao, Wenkang; Ji, Dongsheng; Song, Tao; Wang, Yonghong

    2016-09-01

    Nitrate salts represent a major component of fine mode aerosols, which play an important role in air pollution worldwide. Based on on-line and off-line aerosol measurements in urban Beijing for both clean and haze conditions, we demonstrate that the absolute and relative concentrations of nitrate increased with visibility degradation (relative humidity), whereas the variations of organics tracked the patterns of mixing-layer height and temperature. We propose that the increase in the relative contribution of nitrate to PM1 observed during the early stages of haze pollution was due to new particle formation, whereas the nitrate formed in PM1-2.5 during the latter stages was due to heterogeneous formation and hygroscopic growth. The increasing trend of nitrate (and also sulfate and ammonium) but decreasing trends of organics during haze development, together with the increase of the NO2/SO2 molar ratio with increasing proximity to downtown Beijing and with visibility degradation, provide further evidence that controlling NOx emissions should be a priority for improving air quality in mega cities. Additional large-scale investigation is required to adequately characterize the regional features of NOx-induced haze pollution in China. Such studies may provide insight into the formation of critical nuclei or the subsequent growth of freshly nucleated particles and advance our understanding of the role of nitrate in new particle formation.

  1. Planck Intermediate Results. IX. Detection of the Galactic haze with Planck

    CERN Document Server

    Ade, P A R; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Balbi, A; Banday, A J; Barreiro, R B; Bartlett, J G; Battaner, E; Benabed, K; Benoît, A; Bernard, J -P; Bersanelli, M; Bonaldi, A; Bond, J R; Borrill, J; Bouchet, F R; Burigana, C; Cabella, P; Cardoso, J -F; Catalano, A; Cayón, L; Chary, R -R; Chiang, L -Y; Christensen, P R; Clements, D L; Colombo, L P L; Coulais, A; Crill, B P; Cuttaia, F; Danese, L; D'Arcangelo, O; Davis, R J; de Bernardis, P; de Gasperis, G; de Rosa, A; de Zotti, G; Delabrouille, J; Dickinson, C; Diego, J M; Dobler, G; Dole, H; Donzelli, S; Doré, O; Dörl, U; Douspis, M; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Finelli, F; Forni, O; Frailis, M; Franceschi, E; Galeotta, S; Ganga, K; Giard, M; Giardino, G; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Hansen, F K; Harrison, D; Helou, G; Henrot-Versillé, S; Hernández-Monteagudo, C; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Huffenberger, K M; Jaffe, T R; Jagemann, T; Jones, W C; Juvela, M; Keihänen, E; Knoche, J; Knox, L; Kunz, M; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Lasenby, A; Lawrence, C R; Leach, S; Leonardi, R; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Maris, M; Martin, P G; Martínez-González, E; Masi, S; Massardi, M; Matarrese, S; Matthai, F; Mazzotta, P; Meinhold, P R; Melchiorri, A; Mendes, L; Mennella, A; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Munshi, D; Murphy, J A; Naselsky, P; Natoli, P; Nørgaard-Nielsen, H U; Noviello, F; Osborne, S; Pajot, F; Paladini, R; Paoletti, D; Partridge, B; Pearson, T J; Perdereau, O; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Poutanen, T; Pratt, G W; Prunet, S; Puget, J -L; Rachen, J P; Rebolo, R; Reinecke, M; Renault, C; Ricciardi, S; Riller, T; Rocha, G; Rosset, C; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Savini, G; Schaefer, B M; Scott, D; Smoot, G F; Stivoli, F; Sudiwala, R; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Türler, M; Umana, G; Valenziano, L; Van Tent, B; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; White, M; Yvon, D; Zacchei, A; Zonca, A

    2012-01-01

    Using precise full-sky observations from Planck, and applying several methods of component separation, we identify and characterize the emission from the Galactic "haze" at microwave wavelengths. The haze is a distinct component of diffuse Galactic emission, roughly centered on the Galactic centre, and extends to |b| ~35 deg in Galactic latitude and |l| ~15 deg in longitude. By combining the Planck data with observations from the WMAP we are able to determine the spectrum of this emission to high accuracy, unhindered by the large systematic biases present in previous analyses. The derived spectrum is consistent with power-law emission with a spectral index of -2.55 +/- 0.05, thus excluding free-free emission as the source and instead favouring hard-spectrum synchrotron radiation from an electron population with a spectrum (number density per energy) dN/dE ~ E^-2.1. At Galactic latitudes |b|<30 deg, the microwave haze morphology is consistent with that of the Fermi gamma-ray "haze" or "bubbles," indicating ...

  2. Research on Haze Value of Wafer Surface%晶片表面Haze值研究

    Institute of Scientific and Technical Information of China (English)

    张伟才; 宋晶; 杨洪星; 赵权

    2011-01-01

    The Haze value of wafer surface is introduced from the definitions and theories based on the principle of SSIS. The Haze is explained as optical signals which can indirectly reflect the state of the wafer surface. The different materials and different surface were scanned by SSIS, and the effect of surface roughness and reflection coefficient on the Haze value and its distribution were studied. The results show that the Haze value of the same material increases with the increase of surface roughness, and the Haze value shows significant differences between different materials with similar roughness. Through the Analysis of the characteristics of scans, the relationship between Haze value distribution and the consistency of wafer surface state was studied. A new process feedback method for chemical mechanical polishing and wet cleaning process using Haze value was proposed.%介绍了晶片表面Haze值的定义和理论依据,通过对SSIS系统的原理分析,揭示了H aze是一种间接反映晶片表面状态的光学信号.通过对不同表面状态抛光片的光学扫描,研究了晶片表面粗糙度与Haze值的关系;通过对Si抛光片和砷化镓抛光片的扫描对比,研究了晶片本体反射系数对Haze值的影响.研究结果表明,同种材料的Haze值随着表面粗糙度的增大而增大,而不同的材料即使拥有相似的表面粗糙度,Haze值也会因本体反射系数的不同而呈现很大差异.通过对Haze扫描图的特征分析,研究了Haze值分布与晶片表面均匀性的关系,成功地利用Haze值分布将表面性状化,为化学机械抛光和湿法清洗工艺提供了一个新的反馈手段.

  3. Characterization of major pollution events (dust, haze, and two festival events) at Agra, India.

    Science.gov (United States)

    Pachauri, Tripti; Singla, Vyoma; Satsangi, Aparna; Lakhani, Anita; Kumari, K Maharaj

    2013-08-01

    Total suspended particulate (TSP) samples were collected during dust, haze, and two festival events (Holi and Diwali) from February 2009 to June 2010. Pollutant gases (NO2, SO2, and O3) along with the meteorological parameters were also measured during the four pollution events at Agra. The concentration of pollutant gases decreases during dust events (DEs), but the levels of the gases increase during other pollution events indicating the impact of anthropogenic emissions. The mass concentrations were about two times higher during pollution events than normal days (NDs). High TSP concentrations during Holi and Diwali events may be attributed to anthropogenic activities while increased combustion sources in addition to stagnant meteorological conditions contributed to high TSP mass during haze events. On the other hand, long-range transport of atmospheric particles plays a major role during DEs. In the dust samples, Ca(2+), Cl(-), NO3 (-), and SO4 (2-) were the most abundant ions and Ca(2+) alone accounted for 22 % of the total ionic mass, while during haze event, the concentrations of secondary aerosols species, viz., NO3 (-), SO4 (2-), and NH4 (+), were 3.6, 3.3, and 5.1 times higher than the normal days. During Diwali, SO4 (2-) concentration (17.8 μg m(-3)) was highest followed by NO3 (-), K(+), and Cl(-) while the Holi samples were strongly enriched with Cl(-) and K(+) which together made up 32.7 % of the total water-soluble ions. The ion balances indicate that the haze samples were acidic. On the other hand, Holi, Diwali, and DE samples were enriched with cations. The carbonaceous aerosol shows strong variation with the highest concentration during Holi followed by haze, Diwali, DEs, and NDs. However, the secondary organic carbon concentration follows the order haze > DEs > Diwali > Holi > NDs. The scanning electron microscope/EDX results indicate that KCl and carbon-rich particles were more dominant during Holi and haze events while DE samples were enriched

  4. The influence of Arctic haze and radiatively active trace gases on the arctic climate

    International Nuclear Information System (INIS)

    Increasing fossil fuel consumption and industrial activities have raised concerns of possible man-induced climate changes. The changes result mostly from increased radiatively active trace gases (RAG) and anthropogenic aerosols in the atmosphere. Among the by-products of combustion, carbon dioxide is the leading RAG. Fossil fuel combustion also generates sulfates and soot, the principal constituents of the Arctic haze. Both CO2 and Arctic haze interact with radiative processes to produce external climate forcing. Due to their strong tendency to absorb visible solar radiation, soot particles result in strong diabatic heating in the Arctic. With a mixing ratio of 10-10, a concentration 1 million times less than H2O, the solar radiative heating produced by particulate soot is still comparable to that of H2O. The Canadian Climate Centre (CCC) has recently completed a climate simulation with a double carbon dioxide scenario. Version 2 of the CCC-GCM includes a mixed-layer ocean and thermodynamic ice model. It allows for the evaluation of climate changes due to an external forcing. The aim of this paper is to compare the climate changes induced by increasing CO2 and Arctic haze. Since both signals are occurring simultaneously, the authors must investigate the individual contributions with a climate model. A preliminary sensitivity study of the Arctic haze (February to May) with interactive sea ice was done. The analysis suggests that the excess of solar radiative heating leads to increasing rates of snow and ice melt during spring and summer. The most sensitive regions are the Canadian Arctic Archipelago and the Greenland Sea. In both regions, the ice is substantially reduced. The anomaly of sea ice amount continues its propagation northward in June and July even though the Arctic haze is absent during that period

  5. Characteristics of aerosol pollution during heavy haze events in Suzhou, China

    Science.gov (United States)

    Tian, Mi; Wang, Huanbo; Chen, Yang; Yang, Fumo; Zhang, Xiaohua; Zou, Qiang; Zhang, Renquan; Ma, Yongliang; He, Kebin

    2016-06-01

    Extremely severe haze weather events occurred in many cities in China, especially in the east part of the country, in January 2013. Comprehensive measurements including hourly concentrations of PM2.5 and its major chemical components (water-soluble inorganic ions, organic carbon (OC), and elemental carbon (EC)) and related gas-phase precursors were conducted via an online monitoring system in Suzhou, a medium-sized city in Jiangsu province, just east of Shanghai. PM2.5 (particulate matter with an aerodynamic diameter of 2.5 µm or less) frequently exceeded 150 µg m-3 on hazy days, with the maximum reaching 324 µg m-3 on 14 January 2013. Unfavorable weather conditions (high relative humidity (RH), and low rainfall, wind speed, and atmospheric pressure) were conducive to haze formation. High concentrations of secondary aerosol species (including SO42-, NO3-, NH4+, and SOC) and gaseous precursors were observed during the first two haze events, while elevated primary carbonaceous species emissions were found during the third haze period, pointing to different haze formation mechanisms. Organic matter (OM), (NH4)2SO4, and NH4NO3 were found to be the major contributors to visibility impairment. High concentrations of sulfate and nitrate might be explained by homogeneous gas-phase reactions under low RH conditions and by heterogeneous processes under relatively high RH conditions. Analysis of air mass trajectory clustering and potential source contribution function showed that aerosol pollution in the studied areas was mainly caused by local activities and surrounding sources transported from nearby cities.

  6. Investigating the haze transport from 1997 biomass burning in Southeast Asia: its impact upon Singapore

    Science.gov (United States)

    Koe, Lawrence C. C.; Arellano, Avelino F.; McGregor, John L.

    The 1997 Indonesia forest fires was an environmental disaster of exceptional proportions. Such a disaster caused massive transboundary air pollution and indiscriminate destruction of biodiversity in the world. The immediate consequence of the fires was the production of large amounts of haze in the region, causing visibility and health problems within Southeast Asia. Furthermore, fires of these magnitudes are potential contributors to global warming and climate change due to the emission of large amounts of greenhouse gases and other pyrogenic products.The long-range transport of fire-related haze in the region is investigated using trajectories from the CSIRO Division of Atmospheric Research Limited Area Model (DARLAM). Emission scenarios were constructed for hotspot areas in Sumatra and Kalimantan for the months of September and October 1997 to determine the period and fire locations most critical to Singapore. This study also examines some transport issues raised from field observations. Results show that fires in the coastal areas of southeast Sumatra and southwest Kalimantan can be potential contributors to transboundary air pollution in Singapore. Singapore was directly affected by haze from these areas whereas Kuala Lumpur was heavily affected by the haze coming from Sumatra. In most cases, Singapore was more affected by fires from Kalimantan than was Kuala Lumpur. This was mainly a result of the shifting of monsoons. The transition of monsoons resulted in weaker low-level winds and shifted convergence zones near to the southeast of Peninsular Malaysia. In addition to severe drought and massive fire activity in 1997, the timing of the monsoon transition has a strong influence on haze transport in the region.

  7. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  8. The classification study of the heavy haze during autumn and winter of Jiangsu%江苏秋冬季重度霾的分型研究

    Institute of Scientific and Technical Information of China (English)

    戴竹君; 刘端阳; 王宏斌; 魏建苏; 姜有山

    2016-01-01

    By analyzing the conventional observation data,sounding data and reanalysis data of NCEP/NCAR,the circulation background,boundary layer characteristics,dynamic conditions,thermal conditions and the airflow trajectory of the heavy haze in Jiangsu Province during autumn and winter of 2014 are discussed.The results show that zonal circulation at 500 hPa was of more straightly west or northwest airflow.The airflow at 500 hPa changed to the northwest can be an indicator that heavy haze will disappear in 6 to 12 hours later.The main surface situations were uniform pattern of pressure,cold front and inverted trough with low pressure.The surface situation changed when heavy haze occurrs.Just before cold front coming,the haze was heaviest.The east path of cold air was more effective for eliminating haze than the middle or western path.In most of the heavy haze days,the bottom of the temperature inversion was near the ground.Lower wind speed of less than 4 m/s was shown to be favorable for the development of haze.The daily variation was obvious with the haze mitigated in the afternoon.As the intensi-ty and duration of temperature inversion are concerned,the inverted trough type was stronger than the cold front west path type,both of them were stronger than the uniform pressure type.But the three types were almost the same in terms of the thickness of inversion. Different types show different inversion intensity,which may be related to the prefrontal temperature enhancement and wind speed on 925 hPa and near ground,as well as air sources.The height of inversion layer is mostly under 300 m,with the intensity of temperature inversion for every hundred meters between 1 to 5℃,and higher relative humidity of greater than 40%and less than 90% were shown to be favorable for the development of haze.Underlying sink motion provided a favorable dy-namic condition for haze,and,weak upward motion at 850 hPa was conducive to the upward development of haze.By using backward trajectory

  9. Analysis of China’s Haze Days in the Winter Half-Year and the Climatic Background during 1961-2012

    Institute of Scientific and Technical Information of China (English)

    SONG Lian-Chun; GAO Rong; LI Ying; WANG Guo-Fu

    2014-01-01

    The characteristics of haze days and the climatic background are analyzed by using daily observations of haze, precipitation, mean and maximum wind speed of 664 meteorological stations for the period of 1961-2012. The results show that haze days occur significantly more often in eastern China than in western China. The annual number of haze days is 5-30 d in most parts of central-eastern China, with some areas experiencing more than 30 d, while less than 5 d are averagely occurring in western China. Haze days are mainly concentrated in the winter half-year, with most in winter, followed by autumn, spring, and then summer. Nearly 20% of annual haze days are experienced in December. The haze days in central-eastern China in the winter half-year have a significant increasing trend of 1.7 d per decade during 1961-2012. There were great increases in haze days in the 1960s, 1970s and the beginning of the 21st century. There was also significant abrupt changes of haze days in the early 1970s and 2000s. From 1961 to 2012, haze days in the winter half-year increased in South China, the middle-lower reaches of the Yangtze River, and North China, but decreased in Northeast China, eastern Northwest China and eastern Southwest China. The number of persistent haze is rising. The Longer the haze, the greater the proportion to the number persistent haze. Certain climatic conditions exacerbated the occurrence of haze. The correlation coefficient between haze days and precipitation days in the winter half-year is mainly negative in central-eastern China. The precipitation days show a decreasing trend in most parts of China, with a rate of around -4.0 d per decade in central-eastern China, which reduces the sedimentation capacity of atmospheric pollutants. During the period of 1961-2012, the correlation coefficients between haze days and mean wind speed and strong wind days are mainly negative in central-eastern China, while there exists positive correlation between haze days and

  10. Research Progress on Haze in China for the Past Ten Years%近10年来中国霾天气研究进展

    Institute of Scientific and Technical Information of China (English)

    万春燕

    2015-01-01

    文章从霾的判别研究、霾天气的成因、霾天气预报研究、霾天气监测技术研究、霾天气治理研究及霾天气尺度研究等6个方面进行梳理。未来需要加强对霾天气的持续动态监测,重视科学技术的更新应用,从动态、整体的视角进行霾天气的综合监测,为制定更为科学的霾天气应对措施提供依据。%The paper reviews the research on haze from the following six aspects:the criteria of haze,the cause of the haze weather,weather forecast of the haze,monitoring technology of the haze weather,the control and governance of the haze and the dimension research of haze weather. To provide a basis for making more scientific measures for haze weather,a continuous dynamic monitoring on haze weather should be strengthened,much more importance shall be attached to the updating and the application of science and technology,and a comprehensive monitoring on haze weather from both the dynamic and holistic perspective shall be conducted in the future research.

  11. Correlation of polishing-induced shallow subsurface damages with laser-induced gray haze damages in fused silica optics

    Science.gov (United States)

    He, Xiang; Zhao, Heng; Wang, Gang; Zhou, Peifan; Ma, Ping

    2016-08-01

    Laser-induced damage in fused silica optics greatly restricts the performances of laser facilities. Gray haze damage, which is always initiated on ceria polished optics, is one of the most important damage morphologies in fused silica optics. In this paper, the laser-induced gray haze damages of four fused silica samples polished with CeO2, Al2O3, ZrO2, and colloidal silica slurries are investigated. Four samples all present gray haze damages with much different damage densities. Then, the polishing-induced contaminant and subsurface damages in four samples are analyzed. The results reveal that the gray haze damages could be initiated on the samples without Ce contaminant and are inclined to show a tight correlation with the shallow subsurface damages.

  12. Characterization of individual aerosol particles collected during a haze episode in Incheon, Korea using the quantitative ED-EPMA technique

    Directory of Open Access Journals (Sweden)

    H. Geng

    2010-11-01

    Full Text Available Haze is an atmospheric phenomenon that leads to low visibility, and is mostly due to elevated levels of fine particulate matter. It can have effects on cloud formation, public health, agriculture, and even the global climate. Although urban haze has been increasing in occurrence over the past several years over the Seoul-Incheon metropolis, Korea, studies of the morphology and chemical composition of ambient aerosol particles by single-particle analysis during haze episodes have rarely been conducted. Herein, a quantitative energy-dispersive electron probe microanalysis (ED-EPMA, called low-Z particle EPMA, was used to analyze individual aerosol particles collected in Incheon, Korea on 13–18 October 2008 (a typical haze episode occurred from 15 to 18 October. Overall, 3600 particles in 12 aerosol samples collected on haze and non-haze days were measured by low-Z particle EPMA. Based on quantitative X-ray analysis, together with secondary electron images of individual particles, we successfully identified the aerosol particle types as follows: elemental carbon (EC, organic carbon (OC, (NH42SO4/NH4HSO4-containing, genuine (fresh and reacted (aged sea-salt, mineral dust (such as aluminosilicate, SiO2, CaCO3/CaMg(CO32, etc., and K-containing, Fe-rich, and fly ash particles. By analyzing the relative abundances of different particle types, it was concluded that (a on non-haze days, reacted sea-salts and reacted mineral dust particles were abundant in both the PM2.5–10 and PM1.0–2.5 fractions (with relative abundances of 65.0% and 57.7%, respectively; whereas on haze days, the relative abundances of OC and (NH42SO4/NH4HSO4-containing particles were significantly elevated, indicating that organic matter and secondary aerosols were abundant in the atmosphere

  13. 雾霾的产生与防治措施%Cause Amalysis amd Prevemtiom Measures of Fog - haze

    Institute of Scientific and Technical Information of China (English)

    李亚新

    2014-01-01

    近年来,我国中东部地区先后出现大面积持续雾霾天气,给人们生产生活造成了严重的影响。本文对雾霾天气形成的条件和污染源进行了分析,阐述了防治雾霾污染、改善空气质量的对策措施。%The fog - haze weather appears frequently in the area of Middle East China in recent years. It seriously affects human production and living. In this article the cause of fog - haze weather formation was analyzed in aspects of fog - haze weather condition and pollution resource. The measures and suggestions to improve the air quality for the prevention and control of fog - haze weather especially were expounded.

  14. Satellite based classification (haze, fog) and affected area estimation over Indo - Pak Sub-Continent

    Science.gov (United States)

    Ghauri, Badar; Zafar, Sumaira

    2016-07-01

    Northern Pakistan and bordering Indian Punjab experience intense smog and fog during fall and winters. Environmentalists have been raising their voices over the situation and demanded control over regional emissions to save the livelihood of millions of dwellers whose trade, commerce and agriculture is at stake because of long smog/ fog spells.. This paper estimates the area affected by haze, smog and fog during 2006- 2010. MODIS (geo-referenced MODIS subsets India1, 2 &3) of the area in Pakistan and India from 2006 to 2010 for the period October to February) were analyzed using state of the art software ENVI 4.2 and ArcGIS 10.2. This process resulted in area belonging to each class that is; haze, smog and fog. On the basis of density, haze and fog cover was determined. Variations in fog cover, its density and identification of location of fog initiation process were also determined using near real time (30 minutes) METEOSAT-7 IODC data where actually fog formation started and then extended to the area of favorable conditions. Haze has been noticed to intensify due to massive burning of agricultural waste (rice husk) in India and Pakistan towards the end of October each year. MODIS thermal anomalies/fire data (MYD 14) were also used to verify this activity on the ground, which results in hazy conditions at regional level during fall months. Haze-affected area during 2006 to 2010 in Pakistan ranged from 155,000 Km2 to 354,000 Km2 and in India it ranged from 333,000 Km2 to 846,000 Km2. Similarly winter fog cover during this period in Pakistan varied from 136,000 Km2 to 381,000 Km2 and in India it was estimated at 327,000 Km2 to 566,000 Km2. This phenomenon was more prominent in India than in Pakistan where and fog cover was at least twice than that was observed in Pakistan. It has been noted that area covered by fog, smog and haze doubled during the study period in the region. Atmospheric dimming during autumn/ fall also reduces the mixing height leading to greater

  15. Seasonal variation of Titan's haze at low and high altitudes from HST-STIS spectroscopy

    Science.gov (United States)

    Karkoschka, Erich

    2016-05-01

    The Space Telescope Imaging Spectrograph accumulated image cubes of Titan in five years between 1997 and 2004 that we calibrated and analyzed. The observations probe Titan's early northern fall to early winter. Methane bands between 543 and 990 nm wavelength are well resolved spectrally, and Titan's latitudinal and center-to-limb reflectivity variations are resolved spatially. A principal component analysis revealed two large components and two small components of less significance. The first principal component describes a variation of Titan's haze below 80 ± 20 km altitude. Haze particles change their size, opacity, and/or shape of the single scattering phase function. The largest and smallest opacities occurred both in 1997 at high southern latitudes and northern latitudes, respectively. The hemispherical asymmetry switched sign in 2002 at low latitudes, in 2003 at mid latitudes, and in early 2004 at high latitudes. The seasonal amplitude increased almost linearly with distance from the Equator. Tropical latitudes had slightly lower opacities than the annual and global average if the observed variation is seasonally symmetric and shaped like a sine curve. The cause for the variation may be condensation of gases onto aerosols seasonally driven by atmospheric dynamics. The second principal component describes a variation of haze opacity at altitudes above 150 ± 50 km. Largest and smallest opacities both occurred in 2004 at northern and high southern latitudes, respectively. The asymmetry switched in late 2001. Tropical latitudes had significantly higher haze opacity than the annual and global average, opposite to the case at low altitudes. The cause for the high-altitude variation may be aerosols transported at varying speeds driven by atmospheric dynamics. We present a seasonal model that completely describes the haze parameters at each altitude, latitude, and time. It compares fairly well with Cassini results obtained since 2004. The north-south asymmetry may

  16. Sulfur MIF, Organic Haze, and the Gaia Hypothesis in the Archean

    Science.gov (United States)

    Domagal-Goldman, S.; James, K. F.

    2006-05-01

    The presence of mass-independent fractionation (MIF) of sulfur isotopes in Archean sedimentary rocks provides evidence for a low-O2 atmosphere prior to 2.4 Ga. Recent data suggest that S-MIF vanished transiently between ~3.2 Ga and 2.8 Ga. The absence of S-MIF after 2.4 Ga is commonly attributed to the rise of O2 in the atmosphere, as the presence of free O2 would have oxidized all sulfur species, thereby erasing any MIF created by atmospheric photochemistry. However, if free O2 did not appear in the atmosphere until 2.4 Ga, then why did S-MIF disappear transiently much earlier? Could S-MIF have been eliminated from the rock record without the presence of free atmospheric O2? We used a 1-dimensional photochemical model to demonstrate how this might have happened. Increasing the CH4/CO2 ratio in the model atmosphere results in the formation of organic haze. If the haze was sufficiently thick, it would have blocked out much of the solar UV radiation shortward of 220 nm that dissociates SO2 and SO, and thereby causes MIF. The haze should also have caused anti-greenhouse cooling and may have triggered the (putative) 2.8-Ga glaciations. Speculatively, an increase in CH4 at 3.0 Ga could have been caused by the evolution of methanogens, while a CH4 decrease at 2.7 Ga could correspond to the evolution of cyanobacteria. The presence of an optically thin organic haze between 2.4 and 2.7 Ga may explain the larger S-MIF values seen at this time, as compared to the early Archean. If such an organic haze existed, it could have resulted in a biologically-mediated negative feedback loop that stabilized the Archean climate. This feedback loop would have operated as follows: an increase in the biological CH4 flux would have led to an increase in haze thickness and a stronger anti-greenhouse effect, cooling the surface. The surface cooling would have caused a reduction of methanogen productivity, thus offsetting the original increase in the CH4 flux. Such stabilizing feedbacks

  17. A weekly heavy haze episode in Hangzhou city in December of 2013: Characteristics, origins and implications

    Science.gov (United States)

    Yu, Shaocai; Zhang, Qingyu; Yan, Renchang; Li, Pengfei; Wang, Si; Liu, Weiping

    2015-04-01

    Air pollution and heavy haze have recently become China's biggest environmental problem due to the rapid economic and industrial developments and urbanization. However, the sources for the formation of the heavy haze for many cities remain unknown. Here, we analyzed the characteristics of air pollution in metropolitan Hangzhou city (China) from November 25 to December 11, 2013, on the basis of surface observations at 8 urban monitoring stations for PM2.5, PM10, O3, NO2, CO and SO2 and satellite observations for aerosol optical thickness. The sources for the formation of heavy haze were identified by the analysis of trajectory clustering, the receptor models such as potential source contribution function and concentration weighted trajectory. The results show that for the weekly heavy haze episode (December 3 to 9), the mean concentrations of PM2.5, PM10, SO2, NO2, and CO are 293.4±103.2, 376.8±119.4, 58.0±37.2, 118.5±39.3 and 2429±740 μg m-3, respectively. The back trajectory cluster analysis indicates that the predominant clusters are south (37.1%) and southeast (28.6%) during the weekly heavy haze episode at Hangzhou. The results of the receptor models show that the sources affecting formation of the extremely high PM2.5 in Hangzhou are mainly located in the southeastern coast of Zhejiang and Fujian provinces, north part of Jiangxi and central part of Jiangsu province. Rather than local emissions, it is also found that air mass pathways and cross-border transports are crucial factors for determining high PM2.5 concentrations and formation in Hangzhou. The two-way coupled WRF-CMAQ model was also used to study the formation of haze in Hangzhou. It is necessary to implement the air pollution control measures for all industrial areas on local, regional, and even national scales in China.

  18. Haze types in Beijing and the influence of agricultural biomass burning

    Directory of Open Access Journals (Sweden)

    W. J. Li

    2010-09-01

    Full Text Available Emissions from agricultural biomass burning (ABB in northern China have a significant impact on the regional and global climate. The monthly average aerosol optical depth (AOD at 550 nm in northern China in 2007 had a maximum of 0.7 in June. The AOD measurements are consistent with regional brown hazes that occurred at that time, which was a period of severe aerosol pollution. Aerosol particles were collected in urban Beijing from 12 to 30 June 2007, during a period of high haze, and studied using transmission electron microscopy with energy-dispersive X-ray spectrometry. The dominant particle types collected in the fine fraction (diameter <1 μm were ammonium sulfate, soot, K2SO4, KNO3, and organic matter, except that the K salts were minor between 21 and 30 June. K-rich particles as tracers of biomass burning, together with wildfire maps, show that intense regional ABB in northern China contributed significantly to the regional haze between 12 and 20 June. We therefore grouped the episodes into type-1 and -2 haze, with the former occurring between 12 and 20 June and the latter between 21 and 30 June. After long-range transport, ABB particles in the type-1 haze exhibited marked changes in morphology, composition, and mixing state. KCl particles were absent, presumably having been converted by heterogeneous reactions to K2SO4 and KNO3. Soot particles were mixed with the other particle types. Abundant organic matter and soluble salts emitted by ABB increased their sizes during transport and resulted in more hygroscopic aerosol particles in downwind areas, becoming additional cloud condensation nuclei. The high AOD (average value 2.2 in Beijing during 12 to 20 June is partly explained by the hygroscopic growth of fine aerosol particles and by the strong absorption of internally mixed soot particles, both coming from regional ABB emissions. Therefore, it is important to consider the

  19. Regional Visibility Statistics in the United States: Natural and Transboundary Pollution Influences, and Implications for the Regional Haze Rule

    OpenAIRE

    Park, Rojkin J.; Jacob, Daniel J.; Kumar, Naresh; Yantosca, Robert M.

    2006-01-01

    The Regional Haze Rule of the US Environmental Protection Agency mandates reduction in US anthropogenic emissions to achieve linear improvement of visibility in wilderness areas over the 2004–18 period toward an endpoint of natural visibility conditions by 2064. Linear improvement is to apply to the mean visibility degradation on the statistically 20% worst days, measured as a Haze Index in units of deciviews (log of aerosol extinction). We use a global chemical transport model (GEOS-Chem) wi...

  20. 1 Mixing state and absorbing properties of black carbon during Arctic haze

    Science.gov (United States)

    Zanatta, Marco; Gysel, Martin; Eleftheriadis, Kosas; Laj, Paolo; Hans-Werner, Jacobi

    2016-04-01

    The Arctic atmosphere is periodically affected by the Arctic haze occurring in spring. One of its particulate components is the black carbon (BC), which is considered to be an important contributor to climate change in the Arctic region. Beside BC-cloud interaction and albedo reduction of snow, BC may influence Arctic climate interacting directly with the solar radiation, warming the corresponding aerosol layer (Flanner, 2013). Such warming depends on BC atmospheric burden and also on the efficiency of BC to absorb light, in fact the light absorption is enhanced by mixing of BC with other atmospheric non-absorbing materials (lensing effect) (Bond et al., 2013). The BC reaching the Arctic is evilly processed, due to long range transport. Aging promote internal mixing and thus absorption enhancement. Such modification of mixing and is quantification after long range transport have been observed in the Atlantic ocean (China et al., 2015) but never investigated in the Arctic. During field experiments conducted at the Zeppelin research site in Svalbard during the 2012 Arctic spring, we investigated the relative precision of different BC measuring techniques; a single particle soot photometer was then used to assess the coating of Arctic black carbon. This allowed quantifying the absorption enhancement induced by internal mixing via optical modelling; the optical assessment of aged black carbon in the arctic will be of major interest for future radiative forcing assessment.Optical characterization of the total aerosol indicated that in 2012 no extreme smoke events took place and that the aerosol population was dominated by fine and non-absorbing particles. Low mean concentration of rBC was found (30 ng m-3), with a mean mass equivalent diameter above 200 nm. rBC concentration detected with the continuous soot monitoring system and the single particle soot photometer was agreeing within 15%. Combining absorption coefficient observed with an aethalometer and rBC mass

  1. Blue-sky thinking

    International Nuclear Information System (INIS)

    Global environmental problems - such as the greenhouse effect, the depletion of natural resources and the accumulation of wastes - have been recognized as common international issues affecting humanity since the 1990s. Sustainable development on a global scale is now sought, for instance, with the establishment of the targets for greenhouse gas reduction in the 1997 Kyoto Protocol, and with the adoption of the Declaration on Sustainable Development at the 2002 Johannesburg Summit. Honda launched the slogan 'Blue Sky for Children' in the 1960s when environmental pollution became a highly visible issue. During that decade we started an aggressive approach aimed at substantial environmental improvement, and unveiled the Compound Vortex Controlled Combustion (CVCC) engine - which used unique low-emission technology - in the United States and Japan. Since then, we have developed the Variable Valve Timing and Lift Electric Control System (VTEC) and the i-VTEC series with innovative engine technology, permitting global production of vehicles that combine high performance with state-of-the-art low-emission technologies. And we continued to work to preserve the global environment by releasing a hybrid vehicle, the Insight, which achieved the most efficient fuel consumption in the world at the time of its introduction in 1998

  2. Blue Angel for green electronics

    Energy Technology Data Exchange (ETDEWEB)

    Boettcher-Tiedemann, C.; Jacobs, B. [Federal Environmental Agency, Berlin (Germany)

    2004-07-01

    The Blue Angel was the first eco-label worldwide. It has been in existence for 26 years. For the last 12 years, modern electronic office and communications equipment has been among the products that are eligible for award of the Blue Angel. The Blue Angel eco-label is an important element of integrated product policy and is aimed towards environmentally sound product design. In addition, health aspects are increasingly being taken into account in criteria development. The use of the label gives innovative companies better market opportunities for products so labelled. For consumers and for purchasers in businesses and public administrations, it gives valuable guidance for product purchase. (orig.)

  3. Tourists’ Perception of Haze Pollution and the Potential Impacts on Travel: Reshaping the Features of Tourism Seasonality in Beijing, China

    Directory of Open Access Journals (Sweden)

    Aiping Zhang

    2015-02-01

    Full Text Available Haze pollution has worsened and has received close attention by news agencies in the past two years. This type of environmental pollution might have a great effect on tourism image and the entire tourism industry of a destination. This study aimed to reveal the potential impacts of haze pollution on the tourism industry. Based on a case study in Beijing using questionnaires for potential tourists, awareness of haze pollution, impacts of haze pollution on travel and attitudes toward the impacts were discussed. The results indicated that haze pollution has a considerable potential impact on travel, and there are distinct differences among travel elements and tourism market segments. Due to its impacts, haze pollution could be taken into account in tourists’ decision-making processes, causing a portion of potential tourists to cancel tourism plans. As a result, tourist arrivals to similar destinations could decrease by a small margin, but the most significant impact could be on the temporal distribution of tourist arrivals, namely tourism seasonality, due to tourists’ “avoiding” psychology.

  4. Blue-green photoluminescence in MCM-41 mesoporous nanotubes

    CERN Document Server

    Shen, J L; Lui, Y L; Cheng, P W; Cheng, C F

    2003-01-01

    Different photoluminescence (PL) techniques have been used to study the blue-green emission from siliceous MCM-41 nanotubes. It was found that the intensity of the blue-green PL is enhanced by rapid thermal annealing (RTA). This enhancement is explained by the generation of twofold-coordinated Si centres and non-bridging oxygen hole centres, in line with the surface properties of MCM-41. On the basis of the analysis of the PL following RTA, polarized PL, and PL excitation, we suggest that the triplet-to-singlet transition of twofold-coordinated silicon centres is responsible for the blue-green PL in MCM-41 nanotubes. (letter to the editor)

  5. Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics

    Science.gov (United States)

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Ng, Tienkhee; Ooi, Boon S.; Liao, Hsien-Yu; Shen, Chao; Chen, Long; Zhu, J. Y.

    2016-06-01

    Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are still characterized by high diffuse transmittance and small direct transmittance, resulting in high optical haze of the substrates. In this study, we proposed a simple methodology for large-scale production of high-transparency, low-haze CNP comprising both long cellulose nanofibrils (CNFs) and short cellulose nanocrystals (CNCs). By varying the CNC/CNF ratio in the hybrid CNP, we could tailor its total transmittance, direct transmittance and diffuse transmittance. By increasing the CNC content, the optical haze of the hybrid CNP could be decreased and its transparency could be increased. The direct transmittance and optical haze of the CNP were 75.1% and 10.0%, respectively, greatly improved from the values of previously reported CNP (31.1% and 62.0%, respectively). Transparent, flexible electrodes were fabricated by coating the hybrid CNP with silver nanowires (AgNWs). The electrodes showed a low sheet resistance (minimum 1.2 Ω sq-1) and a high total transmittance (maximum of 82.5%). The electrodes were used to make a light emitting diode (LED) assembly to demonstrate their potential use in flexible displays.Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are

  6. Chemical characterisation of the haze in Brunei Darussalam during the 1998 episode

    Science.gov (United States)

    Muraleedharan, T. R.; Radojevic, Miroslav; Waugh, Allan; Caruana, Anthony

    Coinciding with the El-Nino Southern Oscillation (ENSO) of 1997-1998, SE Asia experienced a severe air pollution episode locally referred to as haze. The monitoring and response efforts in the region mainly centred around criteria pollutants, though it was obvious that the pollution episode is fundamentally different from classical urban air pollution. This paper reports the results of the first-ever study of the detailed chemical composition of the haze in SE Asia. Although numerous studies of forest fire plumes have been conducted in other parts of the world, ours is the first study to be carried out with the specific aim of identifying and quantifying chemical components which are likely to have long-term human health implications. Volatile organic compounds (VOCs) including BTEX (benzene, toluene, ethylbenzene, and xylene), aldehydes, cresol, phenol, acetic acid, polynuclear aromatic hydrocarbons (PAHs), suspended particles effects.

  7. Trans-Boundary Haze Pollution in Southeast Asia: Sustainability through Plural Environmental Governance

    Directory of Open Access Journals (Sweden)

    Md Saidul Islam

    2016-05-01

    Full Text Available Recurrent haze in Southeast Asian countries including Singapore is largely attributable to rampant forest fires in Indonesia due to, for example, extensive slash-and-burn (S & B culture. Drawing on the “treadmill of production” and environmental governance approach, we examine causes and consequences of this culture. We found that, despite some perceived benefits, its environmental consequences include deforestation, soil erosion and degradation, global warming, threats to biodiversity, and trans-boundary haze pollution, while the societal consequences comprise regional tension, health risks, economic and productivity losses, as well as food insecurity. We propose sustainability through a plural coexistence framework of governance for targeting S & B that incorporates strategies of incentives, education and community resource management.

  8. Nanoimprint-assisted fabrication of high haze metal mesh electrode for solar cells

    Science.gov (United States)

    Iwahashi, Takashi; Yang, Rong; Okabe, Noriaki; Sakurai, Junpei; Lin, Jun; Matsunaga, Daisuke

    2014-12-01

    We propose a concept of transparent electrode for solar cells surpassing conventional transparent conductive oxide. Transparent electrode requires low electrical resistivity, high optical transparency, and high optical haze. Although transparent conductive oxide by chemical vapor deposition is widely used as a transparent electrode for solar cells, a breakthrough of the trade-off between electrical and optical properties is required for further improvement of solar cell efficiency. We demonstrate solution-processed electrode fabrication by using nanoimprint technology and metal nanoparticle ink. Silver mesh electrode is self-aligned on nanoimprinted texture with concave pattern as a template for mesh grid. Our electrode concept can realize desired high optical haze by nanoimprinted texture, as well as low electrical resistivity and high optical transparency by metal mesh electrode simultaneously, which boosts solar cell efficiency.

  9. Karner Blue Butterfly Recovery Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This recovery plan has been prepared by the Karner Blue Butterfly Recovery Team under the leadership of Dr. David Andow, University of Minnesota-St. Paul. Dr. John...

  10. Blue Ocean vs. Five Forces

    OpenAIRE

    Burke, Andrew; Stel, André; Thurik, Roy

    2010-01-01

    textabstractThe article reports on the authors' research in the Netherlands which focused on a profit model in Dutch retail stores and a so-called blue-ocean approach which requires a new market that attracts consumers and increases profits. Topics include the competitive strategy approach to increasing profits. The authors conclude that the blue-ocean strategy or innovation approach is sustainable.

  11. Direct observations of organic aerosols in common wintertime hazes in North China: insights into their size, shape, mixing state, and source

    OpenAIRE

    Chen, S. R.; Xu, L.; Zhang, Y X; Chen, B; Wang, X F; X. Y. Zhang; Zheng, M; Chen, J. M.; Wang, W. X.; Sun, Y L; P. Q. Fu; Z. F. Wang; Li, W. J.

    2016-01-01

    Many studies have focused on the physicochemical properties of aerosol particles in unusually severe haze episodes instead of the more freqent and less severe hazes. Consistent with this lack of attention, the morphology and mixing state of organic matter (OM) particles in the frequent light and moderate (L&M) hazes in winter in North China Plain (NCP) have not been examined, even though OM dominates these fine particles. In the present work, morphology, mixing state, and size of organic aero...

  12. 江苏霾灾害风险与地区差异研究%STUDY OF HAZE RISK AND THE DIFFERENCE OF HAZE AMONG ALL AREAS IN JIANGSU

    Institute of Scientific and Technical Information of China (English)

    田心如; 陈广昌; 武艳; 王伟丽

    2014-01-01

    利用江苏省69个地面气象观测站1980~2012年的气象资料,采用适当的方法定义了霾时概念,讨论了重度、中度、轻度及轻微霾时数的时空分布特征.根据霾灾害特点,以区县为评估单元,综合考虑了致灾因子危险性、孕灾环境敏感性、承载体易损性和防灾减灾能力4个因素,选取中度霾时数、重度霾时数、水域面积、植被面积、人口密度、公路里程、公共财政支出、每万人拥有医生数等8个因子作为评估的主要指标,利用层次分析法建立霾灾害风险评估模型,并借助于GIS分析工具,进行了霾灾害风险区划.%Based on the data collected from 69 surface observation stations during 1961-2012 in Jiangsu province,using proper measures to define the concept of haze hours,the temporal and spatial distribution features of severe,moderate,mild and slight haze hours are discussed in the research.According to the characteristics of haze disasters,the administrative regions (districts and counties) are taken as the basic evaluation unit,considering four factors such as the hazard risk,disaster pregnant environment sensitivity,vulnerability and disaster prevention and reduction capacity.This study selects eight factors including the moderate haze hours,severe haze hours,water area,vegetation area,population density,road mileage,public finance expenditure,the number of doctors per million people possessing as the evaluation indexes,uses the analytic hierarchy process to establish a risk assessment model,and with the help of GIS analysis tool,the haze disaster risk regionalization is given.The research shows that the slight haze is the most haze weather in Jiangsu province,with proportion of 77% in all haze weather.The frequency of severe and moderate haze weather is lower,with proportion of 2% and 4% respectively.The trend of annual haze hours of every grade is identical,rising slightly during 1980-2010,and obviously during 2011-2012.The

  13. Public concerns about transboundary haze: a comparison of Indonesia, Singapore, and Malaysia

    OpenAIRE

    Forsyth, Tim

    2014-01-01

    Public concerns about environmental problems create narrative structures that influence policy by allocating roles of blame, responsibility, and appropriate behavior. This paper presents an analysis of public concerns about transboundary haze resulting from forest fires in Indonesia, Singapore, and Malaysia for crises experienced in 1997, 2005 and 2013. The source of the information is content analysis of 2231 articles from representative newspapers in each country. The study shows that newsp...

  14. Characteristics of aerosol pollution during heavy haze events in Suzhou, China

    OpenAIRE

    Tian, Mi; Wang, Huanbo; Chen, Yang; Yang, Fumo; Zhang, Xiaohua; Zou, Qiang; Zhang, Renquan; Ma, Yongliang; He, Kebin

    2016-01-01

    Extremely severe haze weather events occurred in many cities in China, especially in the east part of the country, in January 2013. Comprehensive measurements including hourly concentrations of PM2.5 and its major chemical components (water-soluble inorganic ions, organic carbon (OC), and elemental carbon (EC)) and related gas-phase precursors were conducted via an online monitoring system in Suzhou, a medium-sized city in Jiangsu province, just east of Shanghai. PM2.5 (part...

  15. Titan's 2 micron Surface Albedo and Haze Optical Depth in 1996-2004

    Energy Technology Data Exchange (ETDEWEB)

    Gibbard, S; de Pater, I; Macintosh, B; Roe, H; Max, C; Young, E; McKay, C

    2004-05-04

    We observed Titan in 1996-2004 with high-resolution 2 {micro}m speckle and adaptive optics imaging at the W.M. Keck Observatory. By observing in a 2 {micro}m broadband filter we obtain images that have contributions from both Titan's surface and atmosphere. We have modeled Titan's atmosphere using a plane-parallel radiative transfer code that has been corrected to agree with 3-D Monte Carlo predictions. We find that Titan's surface albedo ranges from {le} 0:02 in the darkest equatorial region of the trailing hemisphere to {approx_equal} 0:1 in the brightest areas of the leading hemisphere. Over the past quarter of a Saturnian year haze optical depth in Titan's Southern hemisphere has decreased substantially from a value of 0.48 in 1996 down to 0.18 in 2004, while the northern haze has been increasing over the past few years. As a result of these changes, in 2004 the North/South haze asymmetry at K' band has disappeared.

  16. Impact of the June 2013 Riau province Sumatera smoke haze event on regional air pollution

    Science.gov (United States)

    Dewi Ayu Kusumaningtyas, Sheila; Aldrian, Edvin

    2016-07-01

    Forest and land fires in Riau province of Sumatera increase along with the rapid deforestation, land clearing, and are induced by dry climate. Forest and land fires, which occur routinely every year, cause trans-boundary air pollution up to Singapore. Economic losses were felt by Indonesia and Singapore as the affected country thus creates tensions among neighboring countries. A high concentration of aerosols are emitted from fire which degrade the local air quality and reduce visibility. This study aimed to analyze the impact of the June 2013 smoke haze event on the environment and air quality both in Riau and Singapore as well as to characterize the aerosol properties in Singapore during the fire period. Air quality parameters combine with aerosols from Aerosol Robotic Network (AERONET) data and some environmental parameters, i.e. rainfall, visibility, and hotspot numbers are investigated. There are significant relationships between aerosol and environmental parameters both in Riau and Singapore. From Hysplit modeling and a day lag correlation, smoke haze in Singapore is traced back to fire locations in Riau province after propagated one day. Aerosol characterization through aerosol optical depth (AOD), Ångstrom parameter and particle size distribution indicate the presence of fine aerosols in a great number in Singapore, which is characteristic of biomass burning aerosols. Fire and smoke haze even impaired economic activity both in Riau and Singapore, thus leaving some accounted economic losses as reported by some agencies.

  17. Health impacts and economic losses assessment of the 2013 severe haze event in Beijing area.

    Science.gov (United States)

    Gao, Meng; Guttikunda, Sarath K; Carmichael, Gregory R; Wang, Yuesi; Liu, Zirui; Stanier, Charles O; Saide, Pablo E; Yu, Man

    2015-04-01

    Haze is a serious air pollution problem in China, especially in Beijing and surrounding areas, affecting visibility, public health and regional climate. In this study, the Weather Research and Forecasting-Chemistry (WRF-Chem) model was used to simulate PM2.5 (particulate matters with aerodynamic diameter≤2.5 μm) concentrations during the 2013 severe haze event in Beijing, and health impacts and health-related economic losses were calculated based on model results. Compared with surface monitoring data, the model results reflected pollution concentrations accurately (correlation coefficients between simulated and measured PM2.5 were 0.7, 0.4, 0.5 and 0.6 in Beijing, Tianjin, Xianghe and Xinglong stations, respectively). Health impacts assessments show that the PM2.5 concentrations in January might cause 690 (95% confidence interval (CI): (490, 890)) premature deaths, 45,350 (95% CI: (21,640, 57,860)) acute bronchitis and 23,720 (95% CI: (17,090, 29,710)) asthma cases in Beijing area. Results of the economic losses assessments suggest that the haze in January 2013 might lead to 253.8 (95% CI: (170.2, 331.2)) million US$ losses, accounting for 0.08% (95% CI: (0.05%, 0.1%)) of the total 2013 annual gross domestic product (GDP) of Beijing. PMID:25585158

  18. Silver nanowires decorated with silver nanoparticles for low-haze flexible transparent conductive films

    Science.gov (United States)

    Mol Menamparambath, Mini; Muhammed Ajmal, C.; Hee Kim, Kwang; Yang, Daejin; Roh, Jongwook; Cheol Park, Hyeon; Kwak, Chan; Choi, Jae-Young; Baik, Seunghyun

    2015-11-01

    Silver nanowires have attracted much attention for use in flexible transparent conductive films (TCFs) due to their low sheet resistance and flexibility. However, the haze was too high for replacing indium-tin-oxide in high-quality display devices. Herein, we report flexible TCFs, which were prepared using a scalable bar-coating method, with a low sheet resistance (24.1 Ω/sq at 96.4% transmittance) and a haze (1.04%) that is comparable to that of indium-tin-oxide TCFs. To decrease the haze and maintain a low sheet resistance, small diameter silver nanowires (~20 nm) were functionalized with low-temperature surface-sintering silver nanoparticles (~5 nm) using bifunctional cysteamine. The silver nanowire-nanoparticle ink stability was excellent. The sheet resistance of the TCFs was decreased by 29.5% (from 34.2 to 24.1 Ω/sq) due to the functionalization at a low curing temperature of 85 °C. The TCFs were highly flexible and maintained their stability for more than 2 months and 10,000 bending cycles after coating with a protective layer.

  19. Scattering properties of the heterogeneous and non-spherical haze particles in the SWIR band

    International Nuclear Information System (INIS)

    To effectively estimate the influence of multiple scattering caused by haze particles on the misestimating of CO2 concentrations, it is necessary to understand the scattering properties of haze particles in the shortwave infrared (SWIR) wavelength range (∼1.6um) using satellite data. Due to the complexity of structures and components of haze particles, this paper investigates effects of particle size and chemical component on the scattering properties of both single non-spherical particles and aggregates for the 1.6um by using numerically effective medium theory and core-mantle theory. For the single non-spherical particles, the scattering parameters (e.g. scattering phase function, single scattering albedo, extinction coefficient and scattering coefficient) are calculated by combining the T-matrix method and the Maxwell-Garnett effective medium theory. For the aggregates, the particle-cluster aggregation algorithm is used to generate aggregates with different monomer numbers. And then, the Core-Mantle Generalized Multi-particle Mie (CMGMM) method is used to compute the scattering parameters. The results indicate that the scattering characteristics are significantly different for both single non-spherical particles and aggregates

  20. Insights into a historic severe haze event in Shanghai: synoptic situation, boundary layer and pollutants

    Science.gov (United States)

    Leng, Chunpeng; Duan, Junyan; Xu, Chen; Zhang, Hefeng; Wang, Yifan; Wang, Yanyu; Li, Xiang; Kong, Lingdong; Tao, Jun; Zhang, Renjian; Cheng, Tiantao; Zha, Shuping; Yu, Xingna

    2016-07-01

    A historic haze event, characterized by lengthy, large-scale and severe pollution, occurred in the Yangtze River Delta (YRD) of China from 1 to 10 December 2013. This haze event significantly influenced air quality throughout the region, especially in urban areas. Aerosol physical, chemical and optical properties were measured in Shanghai. Sometimes the 1 h average particle concentration (e.g., PM2.5) exceeded 600 µg m-3. Inorganic water-soluble ions in particles, trace gases and aerosol optical coefficients had a similar tendency to increase evidently from clear to hazy episodes. A combination of various factors contributed to the formation and evolution of the haze event, among which meteorological conditions, local anthropogenic emissions and pollutants are the major factors. High pressure system, calm surface wind and subsidence airflow were responsible for the decrease of planetary boundary layer (PBL) and the accumulation of pollutants. Atmospheric visibility correlated strongly with relative humidity (RH), particle number in size of 600-1400 nm other than particulate water-soluble species and particle mass (PM2.5). The particle hygroscopicity plays an important role in atmospheric visibility reduction. The results are somewhat helpful to forecast and eliminate regional atmospheric pollution in China.

  1. Net effect of wort osmotic pressure on fermentation course, yeast vitality, beer flavor, and haze.

    Science.gov (United States)

    Sigler, K; Matoulková, D; Dienstbier, M; Gabriel, P

    2009-04-01

    The net effect of increased wort osmolarity on fermentation time, bottom yeast vitality and sedimentation, beer flavor compounds, and haze was determined in fermentations with 12 degrees all-malt wort supplemented with sorbitol to reach osmolarity equal to 16 degrees and 20 degrees. Three pitchings were performed in 12 degrees/12 degrees/12 degrees, 16 degrees/16 degrees/12 degrees, and 20 degrees/20 degrees/12 degrees worts. Fermentations in 16 degrees and 20 degrees worts decreased yeast vitality measured as acidification power (AP) by a maximum of 10%, lowered yeast proliferation, and increased fermentation time. Repitching aggravated these effects. The 3rd "back to normal" pitching into 12 degrees wort restored the yeast AP and reproductive abilities while the extended fermentation time remained. Yeast sedimentation in 16 degrees and 20 degrees worts was delayed but increased about two times at fermentation end relative to that in 12 degrees wort. Third "back-to-normal" pitching abolished the delay in sedimentation and reduced its extent, which became nearly equal in all variants. Beer brewed at increased osmolarity was characterized by increased levels of diacetyl and pentanedione and lower levels of dimethylsulfide and acetaldehyde. Esters and higher alcohols displayed small variations irrespective of wort osmolarity or repitching. Increased wort osmolarity had no appreciable effect on the haze of green beer and accelerated beer clarification during maturation. In all variants, chill haze increased with repitching. PMID:19122996

  2. SEASONAL DISAPPEARANCE OF FAR-INFRARED HAZE IN TITAN'S STRATOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Donald E.; Anderson, C. M.; Flasar, F. M.; Cottini, V. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Samuelson, R. E.; Nixon, C. A.; Kunde, V. G.; Achterberg, R. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); De Kok, R. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands); Coustenis, A.; Vinatier, S. [LESIA, Observatoire de Paris-Meudon, 92195 Meudon Cedex (France); Calcutt, S. B., E-mail: donald.e.jennings@nasa.gov [Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)

    2012-07-20

    A far-infrared emission band attributed to volatile or refractory haze in Titan's stratosphere has been decreasing in intensity since Cassini's arrival in 2004. The 220 cm{sup -1} feature, first seen by the Voyager Infrared Interferometer Spectrometer, has only been found in Titan's winter polar region. The emission peaks at about 140 km altitude near the winter stratospheric temperature minimum. Observations recorded over the period 2004-2012 by the Composite Infrared Spectrometer on Cassini show a decrease in the intensity of this feature by about a factor of four. Possible seasonal causes of this decline are an increase in photolytic destruction of source chemicals at high altitude, a lessening of condensation as solar heating increased, or a weakening of downwelling of vapors. As of early 2012, the 220 cm{sup -1} haze has not yet been detected in the south. The haze composition is unknown, but its decrease is similar to that of HC{sub 3}N gas in Titan's polar stratosphere, pointing to a nitrile origin.

  3. On the latitudinal distribution of Titan's haze at the Voyager epoch

    Science.gov (United States)

    Negrao, A.; Roos-Serote, M.; Rannou, P.; Rages, K.; McKay, C.

    2002-09-01

    In this work, we re-analyse a total of 10 high phase angle images of Titan (2 from Voyager 1 and 8 from Voyager 2). The images were acquired in different filters of the Voyager Imaging Sub System in 1980 - 1981. We apply a model, developed and used by Rannou etal. (1997) and Cabane etal. (1992), that calculates the vertical (1-D) distribution of haze particles and the I/F radial profiles as a function of a series of parameters. Two of these parameters, the haze particle production rate (P) and imaginary refractive index (xk), are used to obtain fits to the observed I/F profiles at different latitudes. Differerent from previous studies is that we consider all filters simultaneously, in an attempt to better fix the parameter values. We also include the filter response functions, not considered previously. The results show that P does not change significantly as a function of latitude, eventhough somewhat lower values are found at high northern latitudes. xk seems to increase towards southern latitudes. We will compare our results with GCM runs, that can give the haze distribution at the epoch of the observations. Work financed by portuguese Foundation for Science and Tecnology (FCT), contract ESO/PRO/40157/2000

  4. [Characteristics of mass size distributions of water-soluble, inorganic ions during summer and winter haze days of Beijing].

    Science.gov (United States)

    Huang, Yi-Min; Liu, Zi-Rui; Chen, Hong; Wang, Yue-Si

    2013-04-01

    To investigate the size distribution characteristics of water soluble inorganic ions in haze days, the particle samples were collected by two Andersen cascade impactors in Beijing during summer and winter time and each sampling period lasted two weeks. Online measurement of PM10 and PM2.5 using TEOM were also conducted at the same time. Sources and formation mechanism of water soluble inorganic ions were analyzed based on their size distributions. The results showed that average concentrations of PM10 and PM 2.5 were (245.5 +/- 8.4) microg x m(-3) and (120.2 +/- 2.0) microg x m(-3) during summer haze days (SHD), and were (384.2 +/- 30.2) microg x m(-3) and (252.7 +/- 47.1) microg x m(-3) during winter haze days (WHD), which suggested fine particles predominated haze pollution episode in both seasons. Total water-soluble inorganic ions concentrations were higher in haze days than those in non-haze days, especially in fine particles. Furthermore, concentrations of secondary inorganic ions (SO4(2-), NO3(-) and NH4(+)) increased quicker than other inorganic ions in fine particles during haze days, indicating secondary inorganic ions played an important role in the formation of haze pollution. Similar size distributions were found for all Sinorganic water soluble ions except for NO3(-), during SHD and WHD. SO4(2-) and NH4(+) dominated in the fine mode (PM1.0) while Mg2+ and Ca2+ accumulated in coarse fraction, Na+, Cl- and K+ showed a bimodal distribution. For NO3(-), however, it showed a bimodal distribution during SHD and a unimodal distribution dominated in the fine fraction was found during WHD. The average mass median aerodynamic diameter (MMAD) of SO4(2-) was 0.64 microm in SHD, which suggested the formation of SO4(2-) was mainly attributed to in-cloud processes. Furthermore, a higher apparent conversion rate of sulfur dioxide (SOR) was found in SHD, indicating more fine particles were produced by photochemical reaction in haze days than that in non-haze days. The

  5. Long-term trend and spatiotemporal variations of haze over China by satellite observations from 1979 to 2013

    Science.gov (United States)

    Zhang, Xingying; Wang, Ling; Wang, Weihe; Cao, Dongjie; Wang, Xi; Ye, Dianxiu

    2015-10-01

    With the fast development of economy and industry in the past thirty years, many large cities in the eastern and southwestern areas of China are experiencing increased haze events and atmospheric pollution, which causes significant impacts on the regional environment, human health, and even climate. The long-term trend and spatiotemporal variations of haze over China during recent 30 years are investigated using TOMS AAI products. In addition, the heavy haze events that occurred in January 2013 over eastern China are explored using AAI products from TOU on board FY-3A. Validation results show that satellite AAI products can be used for haze monitoring since it is sensitive to the carbonaceous aerosol, which is one of the main components of haze. In China, the high AAI values (>1.0) mainly located in the main four areas with intense anthropogenic activities, except for the desert region in Northwestern China. In the eastern and northeastern region, AAI peaks dominate in spring before 2005 since those areas were always affected by dust in spring. However, after 2005, AAI peaks appear in winter over eastern China because of haze. Moreover, in the northeastern region, AAI peaks dominate in winter with a secondary peak in spring because this area is affected by both dust and haze. In the southern region, the AAI peaks always dominate in spring since the high-level air pollution often occur in spring, but a decreasing trend is acquired during recent ten years. Over eastern China and northeastern China, AAI shows an increasing trend during recent 30 years in winter, which reveals that the haze over these areas is strengthen. A case study result shows that the heavy haze events occurred in January 2013 in eastern China can be clearly identified from the AAI products of TOU/FY-3A. The daily coverage area with AAI > 3.0 peaks at five periods at this time, i.e. Jan. 7-8, Jan. 13, Jan. 18, Jan. 23, and, Jan. 28-29, which agrees well with the haze events recorded by in

  6. Molecular composition and size distribution of sugars, sugar-alcohols and carboxylic acids in airborne particles during a severe urban haze event caused by wheat straw burning

    Science.gov (United States)

    Wang, Gehui; Chen, Chunlei; Li, Jianjun; Zhou, Bianhong; Xie, Mingjie; Hu, Shuyuan; Kawamura, Kimitaka; Chen, Yan

    2011-05-01

    Molecular compositions and size distributions of water-soluble organic compounds (WSOC, i.e., sugars, sugar-alcohols and carboxylic acids) in particles from urban air of Nanjing, China during a severe haze event caused by field burning of wheat straw were characterized and compared with those in the summer and autumn non-haze periods. During the haze event levoglucosan (4030 ng m -3) was the most abundant compound among the measured WSOC, followed by succinic acid, malic acid, glycerol, arabitol and glucose, being different from those in the non-haze samples, in which sucrose or azelaic acid showed a second highest concentration, although levoglucosan was the highest. The measured WSOC in the haze event were 2-20 times more than those in the non-hazy days. Size distribution results showed that there was no significant change in the compound peaks in coarse mode (>2.1 μm) with respect to the haze and non-haze samples, but a large difference in the fine fraction (glucose and related sugar-alcohols whose concentrations significantly increased in the fine haze samples are unclear. Compared to that in the fresh smoke particles of wheat straw burning an increase in relative abundance of succinic acid to levoglucosan during the haze event suggests a significant production of secondary organic aerosols during transport of the smoke plumes.

  7. The development of Haze Events observed by multi-satellite retrievals and Meteorological Analysis: A Case Study over Eastern China in December 2013

    Science.gov (United States)

    Zhang, Xiaoyu; Jiang, Binbin; Du, Yong; Yao, Lingling; Huang, Dasong

    2015-04-01

    With the rapid development of national economy and urbanization, the haze has been one of the environment disasters in eastern China. It is necessary that building a model of monitoring the haze for preventing and solving it in the future. In this study, NPP/AOT(550nm) >1and GOCI/AOT(555nm) >1 are adopted to dynamically monitor severe haze events in December 2013 over eastern China. Meanwhile, wind field data from CDAS-NCEP/DOE Reanalysis data and air temperature data from CDAS-NCEP/FNL are adopted to study the mechanism of the occurrence, migration and decay of the haze events. The haze event is composed of two consecutive cases. The first case occurred during 4-9 December is an exogenous haze for Yangtze River Delta, whereas the second case appeared during 11-15 December is an endogenous haze. This result shows:1) With the improved two-stream approximation model, GOCI is successful used to retrieve AOT with compared AERONET AOT, which demonstrates to be feasible in monitoring severe haze events. 2)Because of the large-scale observation capacity of NPP/AOT(550nm) product (×6km) and the high temporal resolution of GOCI/AOT(555nm), this study establishes a framework that detect the large-scale haze events using both data sets. 3)Weak wind speed of less than 5 m*s-1 is important for the development of the haze but the inversion is not a necessary condition for the haze. The strong cold air mass from the northern Siberia area and from East China Sea is the main force for the immigration, diffusion and decay of this haze event. 4)The air quality around Yangtze River Delta in winter is apt to suffer widely divergent influences including exogenous hazes carried by winter northwestward monsoon flows from northern Asia, and endogenous hazes induced by the rapid development of urbanization. The hit of multiple hazes over Yangtze River Delta lead to one of the most severe polluted regions of haze in China. Key words: NPP/AOT;GOCI/AOT; Haze;dynamic monitoring

  8. 40 CFR 51.308 - Regional haze program requirements.

    Science.gov (United States)

    2010-07-01

    ... the program are needed to enhance performance of the program. (3) A State which opts under 40 CFR 51... stationary sources, mobile sources, and area sources. (v) The State must consider, at a minimum, the... administrative barriers to the operation of the allowance market, and ensure that such procedures apply...

  9. Modeling the Role of Zebra Mussels in the Proliferation of Blue-green Algae in Saginaw Bay, Lake Huron

    Science.gov (United States)

    Under model assumptions from Saginaw Bay 1991, selective rejection of blue-green algae by zebra mussels appears to be a necessary factor in the enhancement of blue-green algae production in the presence of zebra mussels. Enhancement also appears to depend on the increased sedime...

  10. PLAM - a meteorological pollution index for air quality and its applications in fog-haze forecasts in North China

    Science.gov (United States)

    Yang, Y. Q.; Wang, J. Z.; Gong, S. L.; Zhang, X. Y.; Wang, H.; Wang, Y. Q.; Wang, J.; Li, D.; Guo, J. P.

    2016-02-01

    Using surface meteorological observation and high-resolution emission data, this paper discusses the application of the PLAM/h index (Parameter Linking Air-quality to Meteorological conditions/haze) in the prediction of large-scale low visibility and fog-haze events. Based on the two-dimensional probability density function diagnosis model for emissions, the study extends the diagnosis and prediction of the meteorological pollution index PLAM to the regional visibility fog-haze intensity. The results show that combining the influence of regular meteorological conditions and emission factors together in the PLAM/h parameterization scheme is very effective in improving the diagnostic identification ability of the fog-haze weather in North China. The determination coefficients for four seasons (spring, summer, autumn, and winter) between PLAM/h and visibility observation are 0.76, 0.80, 0.96, and 0.86, respectively, and all of their significance levels exceed 0.001, showing the ability of PLAM/h to predict the seasonal changes and differences of fog-haze weather in the North China region. The high-value correlation zones are located in Jing-Jin-Ji (Beijing, Tianjin, Hebei), Bohai Bay rim, and southern Hebei-northern Henan, indicating that the PLAM/h index is related to the distribution of frequent heavy fog-haze weather in North China and the distribution of emission high-value zone. Through comparative analysis of the heavy fog-haze events and large-scale clear-weather processes in winter and summer, it is found that PLAM/h index 24 h forecast is highly correlated with the visibility observation. Therefore, the PLAM/h index has good capability in identification, analysis, and forecasting.

  11. Chemical characteristics of PM2.5 during haze episodes in the urban of Fuzhou,China

    Institute of Scientific and Technical Information of China (English)

    Fuwang Zhang; Lingling Xu; Jinsheng Chen; Xiaoqiu Chen; Zhenchuan Niu; Tong Lei; Chunming Li

    2013-01-01

    Atmospheric fine particles (PM2.5) were collected in this study with middle volume samplers in Fuzhou,China,during both normal days and haze days in summer (September 2007) and winter (January 2008).The concentrations,distributions,and sources of polycyclic aromatic hydrocarbons (PAHs),organic carbon (OC),elemental carbon (EC),and water soluble inorganic ions (WSIIs) were determinated.The results showed that the concentrations of PM2.5,PAHs,OC,EC,and WSIIs were in the orders of haze > normal and winter > summer.The dominant PAHs of PM2.5 in Fuzhou were Fluo,Pyr,Chr,BbF,BkF,BaP,BghiP,and IcdP,which represented about 80.0% of the total PAHs during different sampling periods.The BaPeq concentrations of ∑ PAHs were 0.78,0.99,1.22,and 2.43 ng/m3 in summer normal,summer haze,winter normal,and winter haze,respectively.Secondary pollutants (SO42-,NO3-,NH4+,and OC) were the major chemical compositions of PM2.5,accounting for 69.0%,55.1%,63.4%,and 64.9% of PM2.5 mass in summer normal,summer haze,winter normal,and winter haze,respectively.Correspondingly,secondary organic carbon (SOC) in Fuzhou accounted for 20.1%,48.6%,24.5%,and 50.5% of OC.The average values of nitrogen oxidation ratio (NOR) and sulfur oxidation ratio (SOR) were higher in haze days (0.08 and 0.27) than in normal days (0.05 and 0.22).Higher OC/EC ratios were also found in haze days (5.0) than in normal days (3.3).Correlation analysis demonstrated that visibility had positive correlations with wind speed,and negative correlations with relative humidity and major air pollutants.Overall,the enrichments of PM2.5,OC,EC,SO42-,and NO3-promoted haze formation.Furthermore,the diagnostic ratios of IcdP/(IcdP+ BghiP),IcdP/BghiP,OC/EC,andNO3-/SO42-indicated that vehicle exhaust and coal consumption were the main sources of pollutants in Fuzhou.

  12. Aerosol physical and chemical properties retrieved from ground-based remote sensing measurements during heavy haze days in Beijing winter

    Science.gov (United States)

    Li, Z.; Gu, X.; Wang, L.; Li, D.; Xie, Y.; Li, K.; Dubovik, O.; Schuster, G.; Goloub, P.; Zhang, Y.; Li, L.; Ma, Y.; Xu, H.

    2013-10-01

    With the increase in economic development over the past thirty years, many large cities in eastern and southwestern China are experiencing increased haze events and atmospheric pollution, causing significant impacts on the regional environment and even climate. However, knowledge on the aerosol physical and chemical properties in heavy haze conditions is still insufficient. In this study, two winter heavy haze events in Beijing that occurred in 2011 and 2012 were selected and investigated by using the ground-based remote sensing measurements. We used a CIMEL CE318 sun-sky radiometer to retrieve haze aerosol optical, physical and chemical properties, including aerosol optical depth (AOD), size distribution, complex refractive indices and aerosol fractions identified as black carbon (BC), brown carbon (BrC), mineral dust (DU), ammonium sulfate-like (AS) components and aerosol water content (AW). The retrieval results from a total of five haze days showed that the aerosol loading and properties during the two winter haze events were comparable. Therefore, average heavy haze property parameters were drawn to present a research case for future studies. The average AOD is about 3.0 at 440 nm, and the Ångström exponent is 1.3 from 440 to 870 nm. The fine-mode AOD is 2.8 corresponding to a fine-mode fraction of 0.93. The coarse particles occupied a considerable volume fraction of the bimodal size distribution in winter haze events, with the mean particle radius of 0.21 and 2.9 μm for the fine and coarse modes respectively. The real part of the refractive indices exhibited a relatively flat spectral behavior with an average value of 1.48 from 440 to 1020 nm. The imaginary part showed spectral variation, with the value at 440 nm (about 0.013) higher than the other three wavelengths (about 0.008 at 675 nm). The aerosol composition retrieval results showed that volume fractions of BC, BrC, DU, AS and AW are 1, 2, 49, 15 and 33%, respectively, on average for the investigated

  13. Methylene blue related sterile endophthalmitis.

    Science.gov (United States)

    Lim, A K E; Ulagantheran V, V; Siow, Y C; Lim, K S

    2008-08-01

    To report a case of methylene blue related endophthalmitis. Observational case report. Review of clinical record, photographs. A 60 year old man developed endophthalmitis after methylene blue was accidentally used to stain the anterior capsule during phacoemulsification of cataract. His left visual acuity deteriorated from 6/12 to 6/36 two weeks after the operation. Despite intensive treatment with topical and intravitreal antibiotics, his condition deteriorated. A vitrectomy and silicone oil injection eventually managed to control the progression of the disease and salvage the eye. However the visual outcome remained poor due to corneal decompensation and retinal ischemia. Both vitreous tap and vitreous biopsy were negative for any organism. Methylene blue is extremely toxic to ocular structures and should not be used intraocularly. PMID:19248701

  14. Why Do Proteins Glow Blue?

    CERN Document Server

    Sarkar, Sohini; Hazra, Partha; Mandal, Pankaj

    2014-01-01

    Recent literatures reported blue-green emission from amyloid fibril as exclusive signature of fibril formation. This unusual visible luminescence is regularly used to monitor fibril growth. Blue-green emission has also been observed in crystalline protein and in solution. However, the origin of this emission is not known exactly. Our spectroscopic study of serum proteins reveals that the blue-green emission is a property of protein monomer. Evidences suggest that semiconductor-like band structure of proteins with the optical band-gap in the visible region is possibly the origin of this phenomenon. We show here that the band structure of proteins is primarily the result of electron delocalization through the peptide chain, rather than through the hydrogen bond network in secondary structure.

  15. Causation mechanism analysis for haze pollution related to vehicle emission in Guangzhou, China by employing the fault tree approach.

    Science.gov (United States)

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Xu, Pingru; Qian, Yu

    2016-05-01

    Recently, China has frequently experienced large-scale, severe and persistent haze pollution due to surging urbanization and industrialization and a rapid growth in the number of motor vehicles and energy consumption. The vehicle emission due to the consumption of a large number of fossil fuels is no doubt a critical factor of the haze pollution. This work is focused on the causation mechanism of haze pollution related to the vehicle emission for Guangzhou city by employing the Fault Tree Analysis (FTA) method for the first time. With the establishment of the fault tree system of "Haze weather-Vehicle exhausts explosive emission", all of the important risk factors are discussed and identified by using this deductive FTA method. The qualitative and quantitative assessments of the fault tree system are carried out based on the structure, probability and critical importance degree analysis of the risk factors. The study may provide a new simple and effective tool/strategy for the causation mechanism analysis and risk management of haze pollution in China. PMID:26923237

  16. Process analysis of characteristics of the boundary layer during a heavy haze pollution episode in an inland megacity, China.

    Science.gov (United States)

    Wang, Shan; Liao, Tingting; Wang, Lili; Sun, Yang

    2016-02-01

    Ground observation data from 8 meteorological stations in Xi'an, air mass concentration data from 13 environmental quality monitoring sites in Xi'an, as well as radiosonde observation and wind profile radar data, were used in this study. Thereby, the process, causes and boundary layer meteorological characteristics of a heavy haze episode occurring from 16 to 25 December 2013 in Xi'an were analyzed. Principal component analysis showed that this haze pollution was mainly caused by the high-intensity emission and formation of gaseous pollutants (NO2, CO and SO2) and atmospheric particles (PM2.5 (fine particles) and PM10 (respirable suspended particle). The second cause was the relative humidity and continuous low temperature. The third cause was the allocation of the surface pressure field. The presence of a near-surface temperature inversion at the boundary layer formed favorable stratification conditions for the formation and maintenance of heavy haze pollution. The persistent thick haze layer weakened the solar radiation. Meanwhile, a warming effect in the urban canopy layer and in the transition zone from the urban friction sublayer to the urban canopy was indicated. All these conditions facilitated the maintenance and reinforcement of temperature inversion. The stable atmospheric stratification finally acted on the wind field in the boundary layer, and further weakened the exchange capacity of vertical turbulence. The superposition of a wind field with the horizontal gentle wind induced the typical air stagnation and finally caused the deterioration of air quality during this haze event. PMID:26969553

  17. The effects of dust-haze on mortality are modified by seasons and individual characteristics in Guangzhou, China.

    Science.gov (United States)

    Liu, Tao; Zhang, Yong Hui; Xu, Yan Jun; Lin, Hua Liang; Xu, Xiao Jun; Luo, Yuan; Xiao, Jianpeng; Zeng, Wei Lin; Zhang, Wan Fang; Chu, Cordia; Keogh, Kandice; Rutherford, Shannon; Qian, Zhengmin; Du, Yao Dong; Hu, Mengjue; Ma, Wen Jun

    2014-04-01

    This study aimed to investigate the effects of dust-haze on mortality and to estimate the seasonal and individual-specific modification effects in Guangzhou, China. Mortality, air pollution and meteorological data were collected for 2006-2011. A dust-haze day was defined as daily visibility humidity definition was further divided into light (8-10 km), medium (5-8 km) and heavy dust-haze (<5 km). A distributed lag linear model (DLM) was employed. Light, medium and heavy dust-haze days were associated with increased mortality of 3.4%, 6.8% and 10.4% respectively, at a lag of 0-6 days. This effect was more pronounced during the cold season, for cardiovascular mortality (CVD), respiratory mortality (RESP), in males and people ≥60years. These effects became insignificant after adjustment for PM10. We concluded that dust-haze significantly increased mortality risk in Guangzhou, China, and this effect appears to be dominated by particulate mass and modified by season and individual-specific factors. PMID:24477104

  18. Across the Threshold: A Comparative Analysis of Communitas and Rites of Passage in Sport Hazing and Initiations

    Directory of Open Access Journals (Sweden)

    Jay Johnson

    2011-01-01

    Full Text Available Hazing rituals and ceremonies have been described in traditional,historical world cultures, junior and high school, the military, private schools, paramilitary organizations, fraternities and sororities, as well as sport (Allan and Madden 2008; Bryshun and Young 1999; Campo, Poulos, and Sipple 2005; Fields, Collins, and Comstock 2010; Johnson 2000, 2009; Linhares de Albuquerque and Paes-Machado 2004; Nuwer 1999; Winslow 1999; Zacharda 2009. Student athletes often endure hazing practices with 80% of NCAA athletes reporting some form of initiation (Hoover 1999 in exchange for membership affiliation. This qualitative study compared the similarities and deviationsbetween contemporary initiations and historical traditions defining both the importance of cultures to establish “Rites of Passage” membership gateways and metamorphoses from nonmember to group. Results indicated that despite often abusive hazing ceremonies in sport, marked by hierarchies, power imbalances, and, at times, criminal behaviour, there still exists a demand for an entry ritual by the rookie contingency to mark their membership and identity within theteam structure. Hazing traditions continue in the belief in what Turner (1986describes as Communitas, despite indications from participants that hazing fractured relationships on the team — a marked contradiction of Communitas.

  19. Clouds in the Forecast? A Joint Spitzer and HST Investigation of Clouds and Hazes for Two Exo-Neptunes

    Science.gov (United States)

    Kreidberg, Laura; Morley, Caroline; Line, Michael; Stevenson, Kevin; Dragomir, Diana

    2016-08-01

    Recent observations of transiting planets have revealed that clouds and hazes are common in exoplanet atmospheres. Little is known, however, about how the clouds/hazes form, what their composition is, and how their properties vary with planet parameters. We propose to characterize the atmospheres of two exo-Neptunes, GJ 436b and GJ 3470b, both of which show evidence for clouds or hazes in their near-infrared spectra. We will measure precise 3.6 and 4.5 micron transit depths for these planets, to compare with existing high-precision data at shorter wavelengths. We will also obtain a UV spectrum for GJ 3470 with HST/COS to enable accurate models of the planet's photochemistry. These observations will enable us to distinguish at high confidence between a range of physically realistic models for the atmospheric chemistry, including methanogenic photochemical hazes and equilibrium salt/sulfide clouds. The measurements will enable comparative planetology with the handful of other small, cool worlds currently accessible to observation, and serve as a first assessment of the prevalence, origin, and composition of clouds and haze in metal-enriched atmospheres below 1000 K. Our findings will guide the design of future observations of increasingly Earth-like worlds with JWST.

  20. The blue-collar brain.

    Science.gov (United States)

    Van Orden, Guy; Hollis, Geoff; Wallot, Sebastian

    2012-01-01

    Much effort has gone into elucidating control of the body by the brain, less so the role of the body in controlling the brain. This essay develops the idea that the brain does a great deal of work in the service of behavior that is controlled by the body, a blue-collar role compared to the white-collar control exercised by the body. The argument that supports a blue-collar role for the brain is also consistent with recent discoveries clarifying the white-collar role of synergies across the body's tensegrity structure, and the evidence of critical phenomena in brain and behavior. PMID:22719730

  1. Toluidine blue: the mode of photodynamic action in yeast cells

    International Nuclear Information System (INIS)

    Toluidine blue, a thiazine dye, was shown to have in vivo photodynamic activity through singlet oxygen (O21Δsub(g)) production. This was based mainly on the effective protection by N3- and the marked enhancement in D2O for the sensitized inactivation of yeast cells. The mode of the in vivo activity was, however, quite different from that of acridine orange, for which the singlet oxygen mechanism has also been proposed. The most characteristic feature in the toluidine blue-sensitization was the total lack of the induction of gene conversion (at trp 5), while the survival went down below 10%. The non-induction of genetic changes was confirmed at several pH's in the neutral region, whereas the inactivation was seen in parallel to the reported pH dependence of singlet oxygen production in vitro. Direct measurements by microspectrophotometry showed none of the toluidine blue was accumulated in the cell. It was also ascertained from acridine-sensitized induction of gene conversion that toluidine blue never interfered with the binding of acridine orange to cellular DNA. These findings suggested that the unique mode of photodynamic activity of toluidine blue is attributable to its action from outside of the cell. Furthermore, comparisons between the photodynamically treated cells (with toluidine blue) and non-treated cells with respect to the response to UV irradiation excluded certain cell functions relating to the expression of gene conversion from the possible damage sites. The photoreactivation process of UV induced gene conversion was not distributed by the pre-toluidine blue sensitization. In view of the foregoing results, the plasma membrane was tentatively suggested as the most likely site of damage. (author)

  2. Efficiency of enzymatic and other alternative clarification and fining treatments on turbidity and haze in cherry juice

    DEFF Research Database (Denmark)

    Meyer, Anne Boye Strunge; Köser, C.; Adler-Nissen, Jens

    2001-01-01

    function. Individual and interactive effects on turbidity and haze formation in precentrifuged and uncentrifuged cherry juice of treatments with pectinase, acid protease, bromelain, gallic acid, and gelatin-silica sol were investigated in a factorial experimental design with 32 different parameter...... combinations. Gelatin-silica sol consistently had the best effect on juice clarity. Centrifugation of cherry juice (10000g for 15 min) prior to clarification treatment significantly improved juice clarity and diminished the rate of haze formation during cold storage of juice. Both treatment of precentrifuged...... cherry juice with Novozym 89L protease and co- addition of pectinase and gallic acid improved cherry juice clarity and diminished haze levels. None of the alternative treatments produced the unwieldy colloids notorious to gelatin- silica sol treatment. The data suggest that several alternative...

  3. Nobel Prize for blue LEDs

    Science.gov (United States)

    Kraftmakher, Yaakov

    2015-05-01

    A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent light bulbs caused by the Planck distribution and properties of the human eye are illustrated. The efficiency and luminous efficacy of thermal radiation are calculated for various temperatures; the results clearly show the limitations for thermal radiators. The only way to overcome these limitations is using non-thermal radiators, such as fluorescent lamps and light-emitting diodes (LEDs). Unique advantages of LEDs undoubtedly made a revolution in this field. A crucial element of this progress is the blue LEDs (Nobel Prize 2014). Some experiments with a blue and a green LED are described: (i) the luminescence triggered in a green-yellow phosphor inside a white LED by the blue LED; (ii) radiant spectra and ‘efficiency droop’ in the LEDs; (iii) modulation of the blue LED up to 4 MHz; and (iv) the h/e ratio from the turn-on voltage of the green LED. The experiments are suitable for undergraduate laboratories and usable as classroom demonstrations.

  4. Interannual increase of regional haze-fog in North China Plain in summer by intensified easterly winds and orographic forcing

    Science.gov (United States)

    Cao, Ziqi; Sheng, Lifang; Liu, Qian; Yao, Xiaohong; Wang, Wencai

    2015-12-01

    Regional haze-fog events over the North China Plain (NCP) have attracted much attention in recent years. Their increase has been attributed to anthropogenic emissions of air pollutants and synoptic weather conditions. We investigated the influence of local meteorological conditions and large-scale circulation on the haze-fog events over the NCP during 2001-2012, and found a significant interannual increase in the number of summer regional haze-fog days. Analysis indicated that local meteorological conditions could partly explain the increase but failed to explain the spatial variation; meanwhile, regional circulation change induced by large-scale circulation and orographic forcing unveiled a possible spatiotemporal variation mechanism. In summer, the prevalent southerly winds over the NCP were obstructed by the Taihang and Yanshan mountains, steadying the outflow direction to the southeast, while different inflow direction controlled by large-scale circulation had different effects on regional circulation. In weak (strong) East Asian summer monsoon years, an intensified eastward (westward) zonal inflow wind component reinforced (weakened) the negative vorticity and formed an anomalous anticyclone (cyclone), which strengthened (weakened) the downward motion, so the dissipation capability was weakened (strengthened) and the wind speed decreased (increased), ultimately resulting in the increased (decreased) occurrence of haze-fog. We also found that the circulation anomaly had a good relationship with strong El Niño and La Niña events. There was more haze-fog over the NCP in the summers that followed a La Niña event, and less in summers that followed an El Niño event. This suggested the possibility that summer haze-fog phenomena could be predicted based on the phase of ENSO.

  5. Characterizing Urban Turbulence Under Haze Pollution: Insights into Temperature-Humidity Dissimilarity

    Science.gov (United States)

    Guo, Xiaofeng; Sun, Yele; Miao, Shiguang

    2016-03-01

    We present a description of urban boundary-layer turbulence characteristics under conditions of severe haze pollution, an emerging issue of interest to air-pollution-relevant investigations. Comparative analysis between clean and hazy episodes reveals their remarkable difference in atmospheric stability. A stability signature is then identified in temperature-humidity de-correlation and dissimilarity. Such a signature is noteworthy, because the accuracy of a reliable parametrization of the heat-to-moisture transport efficiency is substantiated in unstable and stable conditions rather than in near-neutral conditions.

  6. The Optimal Dispatch of a Power System Containing Virtual Power Plants under Fog and Haze Weather

    OpenAIRE

    Yajing Gao; Huaxin Cheng; Jing Zhu; Haifeng Liang; Peng Li

    2016-01-01

    With the growing influence of fog and haze (F-H) weather and the rapid development of distributed energy resources (DERs) and smart grids, the concept of the virtual power plant (VPP) employed in this study would help to solve the dispatch problem caused by multiple DERs connected to the power grid. The effects of F-H weather on photovoltaic output forecast, load forecast and power system dispatch are discussed according to real case data. The wavelet neural network (WNN) model was employed t...

  7. Individual metal-bearing particles in a regional haze caused by firecracker and firework emissions

    International Nuclear Information System (INIS)

    Intensive firecracker/firework displays during Chinese New Year (CNY) release fine particles and gaseous pollutants into the atmosphere, which may lead to serious air pollution. We monitored ambient PM2.5 and black carbon (BC) concentrations at a regional background site in the Yellow River Delta region during the CNY in 2011. Our monitoring data and MOUDI images showed that there was a haze event during the CNY. Daily average PM2.5 concentration reached 183 μg m−3 during the CNY, which was six times higher than that before and after the CNY. Similarly, the black carbon (BC) concentrations were elevated during the CNY. In order to confirm whether the firecracker/firework related emission is the main source of the haze particles, we further analyzed the morphology and chemical composition of individual airborne particles collected before, during and after the CNY by using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM/EDS). We found that sulfate and organic-rich particles were dominant in the atmosphere before and after the CNY. In contrast, K-rich sulfates and other metal (e.g., Ba-rich, Al-rich, Mg-rich, and Fe-rich) particles were much more abundant than ammoniated sulfate particles during the CNY. These data suggest that it was the aerosol particles from the firecracker/firework emissions that induced the regional haze episode during the CNY. In individual organic and K-rich particles, we often found more than two types of nano-metal particles. These metal-bearing particles also contained abundant S but not Cl. In contrast, fresh metal-bearing particles from firecrackers generated in the laboratory contained abundant Cl with minor amounts of S. This indicates that the firecracker/firework emissions during the CNY significantly changed the atmospheric transformation pathway of SO2 to sulfate. - Highlights: ► TEM was used to observe the aged individual particles from firecrackers/fireworks during the Chinese New Year

  8. Chromophore Deprotonation State Alters the Optical Properties of Blue Chromoprotein.

    Directory of Open Access Journals (Sweden)

    Cheng-Yi Chiang

    Full Text Available Chromoproteins (CPs have unique colors and can be used in biological applications. In this work, a novel blue CP with a maximum absorption peak (λmax at 608 nm was identified from the carpet anemone Stichodactyla gigantea (sgBP. In vivo expression of sgBP in zebrafish would change the appearance of the fishes to have a blue color, indicating the potential biomarker function. To enhance the color properties, the crystal structure of sgBP at 2.25 Å resolution was determined to allow structure-based protein engineering. Among the mutations conducted in the Gln-Tyr-Gly chromophore and chromophore environment, a S157C mutation shifted the λmax to 604 nm with an extinction coefficient (ε of 58,029 M-1·cm-1 and darkened the blue color expression. The S157C mutation in the sgBP chromophore environment could affect the color expression by altering the deprotonation state of the phenolic group in the chromophore. Our results provide a structural basis for the blue color enhancement of the biomarker development.

  9. Efficiency of enzymatic and other alternative clarification and fining treatments on turbidity and haze in cherry juice

    DEFF Research Database (Denmark)

    Meyer, Anne Boye Strunge; Köser, C.; Adler-Nissen, Jens

    2001-01-01

    function. Individual and interactive effects on turbidity and haze formation in precentrifuged and uncentrifuged cherry juice of treatments with pectinase, acid protease, bromelain, gallic acid, and gelatin-silica sol were investigated in a factorial experimental design with 32 different parameter...... cherry juice with Novozym 89L protease and co- addition of pectinase and gallic acid improved cherry juice clarity and diminished haze levels. None of the alternative treatments produced the unwieldy colloids notorious to gelatin- silica sol treatment. The data suggest that several alternative...

  10. Artificial intelligence based approach to forecast PM2.5 during haze episodes: A case study of Delhi, India

    Science.gov (United States)

    Mishra, Dhirendra; Goyal, P.; Upadhyay, Abhishek

    2015-02-01

    Delhi has been listed as the worst performer across the world with respect to the presence of alarmingly high level of haze episodes, exposing the residents here to a host of diseases including respiratory disease, chronic obstructive pulmonary disorder and lung cancer. This study aimed to analyze the haze episodes in a year and to develop the forecasting methodologies for it. The air pollutants, e.g., CO, O3, NO2, SO2, PM2.5 as well as meteorological parameters (pressure, temperature, wind speed, wind direction index, relative humidity, visibility, dew point temperature, etc.) have been used in the present study to analyze the haze episodes in Delhi urban area. The nature of these episodes, their possible causes, and their major features are discussed in terms of fine particulate matter (PM2.5) and relative humidity. The correlation matrix shows that temperature, pressure, wind speed, O3, and dew point temperature are the dominating variables for PM2.5 concentrations in Delhi. The hour-by-hour analysis of past data pattern at different monitoring stations suggest that the haze hours were occurred approximately 48% of the total observed hours in the year, 2012 over Delhi urban area. The haze hour forecasting models in terms of PM2.5 concentrations (more than 50 μg/m3) and relative humidity (less than 90%) have been developed through artificial intelligence based Neuro-Fuzzy (NF) techniques and compared with the other modeling techniques e.g., multiple linear regression (MLR), and artificial neural network (ANN). The haze hour's data for nine months, i.e. from January to September have been chosen for training and remaining three months, i.e., October to December in the year 2012 are chosen for validation of the developed models. The forecasted results are compared with the observed values with different statistical measures, e.g., correlation coefficients (R), normalized mean square error (NMSE), fractional bias (FB) and index of agreement (IOA). The performed

  11. Photophysics of the blue fluorescent protein

    International Nuclear Information System (INIS)

    The blue fluorescent protein (BFP) is a mutant of the green fluorescent protein, where the phenolic ring of the chromophore has been replaced by imidazole cycle of histidine residue. The usability of BFP as a fluorescent marker is hampered by its low fluorescence quantum yield at room temperature. The intensity of fluorescence increases by a factor of 4.5 when the temperature is decreased from 320 K down to 225 K. The fluorescence is also enhanced by hydrostatic pressure. Both effects have been explained by shift of the equilibrium between hydrogen nonbonded and hydrogen-bonded chromophores. Our semi-empirical quantum chemical calculations show that the fluorescence quantum yield of the BFP chromophore is low due to isomerization in the electronically excited state -twisting of the bridging bond by 90 deg. At this twisted geometry the potential energy surfaces of ground and excited states are situated close to each other facilitating efficient nonradiative decay

  12. Flavour production of Stilton blue cheese microflora

    OpenAIRE

    Gkatzionis, Konstantinos

    2010-01-01

    In the blue cheese Stilton the starter mould Penicillium roqueforti grows and sporulates during the ripening period and is considered to be responsible for the unique blue cheese aroma. However, the sporulation of the mould, which results in the formation of blue veins, takes place in a fraction of the Stilton matrix which overall is very heterogeneous. Most blue cheeses develop a secondary microflora of yeasts which may affect their aroma. The aim of this study was to investigate the yeast f...

  13. Chemical composition and bioreactivity of PM2.5 during 2013 haze events in China

    Science.gov (United States)

    Ho, Kin-Fai; Ho, Steven Sai Hang; Huang, Ru-Jin; Chuang, Hsiao-Chi; Cao, Jun-Ji; Han, Yongming; Lui, Ka-Hei; Ning, Zhi; Chuang, Kai-Jen; Cheng, Tsun-Jen; Lee, Shun-Cheng; Hu, Di; Wang, Bei; Zhang, Renjian

    2016-02-01

    Chemical composition and bioreactivity of PM2.5 samples collected from Beijing (BJ), Xi'an (XA), Xiamen (XM) and Hong Kong (HK) in China during haze events were characterized. PM2.5 mass concentrations in BJ, XA, XM and HK in the episodes were found to be 258 ± 100 μg m-3, 233 ± 52 μg m-3, 46 ± 9 μg m-3 and 48 ± 13 μg m-3, respectively. Significant increase of sulfate, nitrate and ammonium concentrations in northern cities were observed. High contributions of biomass burning emissions to organic carbon (OC) in northern cities were estimated in this study implying frequent biomass burning during the haze periods. The urea concentrations in PM2.5 were 1855 ± 755 ng m-3 (BJ), 1124 ± 243 ng m-3 (XA), 543 ± 104 ng m-3 (XM) and 363 ± 61 ng m-3 (HK) suggesting higher or close to upper limits compared to other regions in the world. Dose-dependent alterations in oxidative potential, IL-6, IFN-γ and TNF-α levels were also investigated. The oxidative potential levels are BJ > XM > XA > HK, whereas levels of IL-6, IFN-γ and TNF-α were BJ > XA > XM > HK. The sulfate, nitrate, ammonium, OC, urea and levoglucosan are associated with oxidative-inflammatory responses. These experimental results are crucial for the policymakers to implement cost-effective abatement strategies for improving air quality.

  14. Chemistry of Forest Fires and Regional Haze with Emphasis on Southeast Asia

    Science.gov (United States)

    Radojevic, M.

    - The current state of knowledge regarding the chemistry of forest fires and regional haze is reviewed. More than 100 compounds have been identified in wood smoke and many of these have also been observed in field studies. Products of biomass combustion can have different environmental effects: CO2 and CH4 may contribute to global warming, NOx and SO2 could contribute to rainwater acidity, whereas smoke particles and polynuclear aromatic hydrocarbons (PAHs) could affect human health. Also, photochemical reactions of primary emissions from biomass fires can lead to the production of secondary pollutants such as O3. Regional haze episodes caused by forest fires have occurred in SE Asia on several occasions during the 1990s and the reported studies of these episodes are reviewed. Only total suspended particles (TSP) were determined in the earlier studies, and more comprehensive chemical investigations have only emerged during the more recent episodes, notably those of 1997 and 1998. To date, most of the measurements have centred on criteria pollutants (SO2, NO2, CO, O3 and PM10), however, other pollutants (e.g., VOCs, PAHs) have also been determined in certain studies. Rainwater analyses suggest that forest fires do not have a major acidifying effect because dissolved acidic gases (e.g., SO2) are neutralised by alkaline substances (e.g., Ca, Mg, K) that are also emitted by forest fires. There is a need for further laboratory and field studies in order to investigate important pollutant transformation mechanisms.

  15. Approaches to prevent the patients with chronic airway diseases from exacerbation in the haze weather

    Science.gov (United States)

    Ren, Jin; Li, Bo; Yu, Dan; Liu, Jing

    2016-01-01

    Haze weather is becoming one of the biggest problems in many big cities in China. It triggers both public anxiety and official concerns. Particulate matter (PM) plays the most important role in causing the adverse health effects. Chemical composition of PM2.5 includes primary particles and secondary particles. The toxicological mechanisms of PM2.5 to the human body include the oxidative stress, inflammation and carcinogenesis. Short or long-term exposure to PM (especially PM2.5) can cause a series of symptoms including respiratory symptoms such as cough, wheezing and dyspnea as well as other symptoms. There are positive associations between PM2.5 and mortality due to a number of causes. PM2.5 is considered to contribute to the onset of asthma, the exacerbation of chronic obstructive pulmonary disease (COPD) in haze weather. Some approaches including outdoor health care, indoor health care and preventive medications can prevent the patients with chronic airway diseases from exacerbations. PMID:26904232

  16. Effect of heavy haze and aerosol pollution on rice and wheat productions in China

    Science.gov (United States)

    Tie, Xuexi; Huang, Ru-Jin; Dai, Wenting; Cao, Junji; Long, Xin; Su, Xiaoli; Zhao, Shuyu; Wang, Qiyuan; Li, Guohui

    2016-07-01

    In China, regional haze pollution is a serious environmental problem. The impact on ecosystem, however, is not clearly understood. This study investigates the effect of regional haze pollution on the yields of rice and wheat in China. The spatial and temporal distributions of aerosol optical depth (AOD) show high particulate pollution in the North China Plain region, Yangtze River Delta region, the central eastern China, and the Si Chuan Basin, coexisted largely with crop growth in time and space. The solar irradiance reaching these regions is estimated to reduce by up to 28–49%, calculated using the AOD distributions and tropospheric ultraviolet-visible (TUV) model. Reduction of solar irradiance in these regions can depress optimal yields of about 45% of rice and 75% of wheat growth in China, leading to 2% reduction in total rice production and 8% reduction in total wheat production in China. However, there are large uncertainties of the estimate related to the diffuse solar radiation. For high diffuse radiation case, the estimate reductions of rice and wheat decrease to 1% and 4.5%, respectively. A further detailed study is needed to clearly understand this effect to meet the growing food demand in the nation in the coming decades.

  17. Mariner 9 television limb observations of dust and ice hazes on Mars

    International Nuclear Information System (INIS)

    Over 3000 Mariner 9 television reflectance profiles crossing the limb of Mars were analyzed statistically during the period from the decaying phase of a global dust storm (southern summer) until southern winter solstice. Most of the profiles were obtained during the first 100 days of the mission. The ''top'' of the dust, as defined by the inflection point in the reflectance profiles, decreased with time during the decay of the dust storm, but more rapidly in the higher latitudes of both hemispheres than in the tropics. The inflection point due to dust haze remained above 20 km in the tropics throughout the period. These variations support the hypothesis that the diurnal tide is the primary agent of vertical dust transport. Scale heights of the upper portion of the dust cloud were highest in the tropics early in the mission, decaying with time and/or depth in the atmosphere. If interpreted in terms of vertical eddy diffusion, the scale heights suggest diffusion coefficients of order 103 m2 s-1 in the 40--60 km height range. Distribution, color and polarization of higher limb hazes were also analyzed. These are interpreted as condensate layers associated with convective overshoot from the dusty lower atmosphere. A long internal gravity wave revealed by one of these layers is discussed

  18. Effect of heavy haze and aerosol pollution on rice and wheat productions in China.

    Science.gov (United States)

    Tie, Xuexi; Huang, Ru-Jin; Dai, Wenting; Cao, Junji; Long, Xin; Su, Xiaoli; Zhao, Shuyu; Wang, Qiyuan; Li, Guohui

    2016-01-01

    In China, regional haze pollution is a serious environmental problem. The impact on ecosystem, however, is not clearly understood. This study investigates the effect of regional haze pollution on the yields of rice and wheat in China. The spatial and temporal distributions of aerosol optical depth (AOD) show high particulate pollution in the North China Plain region, Yangtze River Delta region, the central eastern China, and the Si Chuan Basin, coexisted largely with crop growth in time and space. The solar irradiance reaching these regions is estimated to reduce by up to 28-49%, calculated using the AOD distributions and tropospheric ultraviolet-visible (TUV) model. Reduction of solar irradiance in these regions can depress optimal yields of about 45% of rice and 75% of wheat growth in China, leading to 2% reduction in total rice production and 8% reduction in total wheat production in China. However, there are large uncertainties of the estimate related to the diffuse solar radiation. For high diffuse radiation case, the estimate reductions of rice and wheat decrease to 1% and 4.5%, respectively. A further detailed study is needed to clearly understand this effect to meet the growing food demand in the nation in the coming decades. PMID:27388031

  19. Organic composition of aerosol particulate matter during a haze episode in Kuala Lumpur, Malaysia

    Science.gov (United States)

    Radzi Bin Abas, M.; Rahman, Noorsaadah A.; Omar, Nasr Yousef M. J.; Maah, M. Jamil; Abu Samah, Azizan; Oros, Daniel R.; Otto, Angelika; Simoneit, Bernd R. T.

    The solvent-extractable compounds of urban airborne particulate matter were analyzed to determine the distributions of homologous and biomarker tracers. Samples were collected by high-volume air filtration during the haze episode of 1997 around the University of Malaya campus near Petaling Jaya, a suburb of Kuala Lumpur, Malaysia. These results show that the samples contain n-alkanes, n-alkan-2-ones, n-alkanols, methyl n-alkanoates, n-alkyl nitriles, n-alkanals, n-alkanoic acids, levoglucosan, PAHs, and UCM as the dominant components, with minor amounts of terpenoids, glyceryl esters and sterols, all derived from natural biogenic sources (vascular plant wax), from burning of biomass, and from anthropogenic utilization of fossil fuel products (lubricating oil, vehicle emissions, etc.). Some compositional differences are observed in the samples and greater atmospheric concentrations were found for almost all organic components in the samples collected near a roadway. The results interpreted in terms of major sources are due to local build-up of organic contaminants from vehicular emissions, smoke from biomass burning, and natural background as a result of the atmospheric stability during the haze episodes. The organic components transported in from areas outside the region, assuming all smoke components are external to the city, amount to about 30% of the total organic particle burden.

  20. Thermoluminescence (TL) of Egyptian Blue

    Energy Technology Data Exchange (ETDEWEB)

    Schvoerer, M.; Delavergne, M.-C.; Chapoulie, R.

    1988-01-01

    Egyptian Blue is a synthesized crystalline pictorial pigment with formula CaCuSi/sub 4/O/sub 10/. It has been used in Egypt and Mesopotamia from the 3rd millenium B.C. A preliminary experiment on a recently synthesized sample showed that this pigment is thermoluminescent after ..beta.. irradiation (/sup 90/Sr). As the signal intensity grows linearly with the administered dose within the temperature range commonly used in TL dating, we have been looking for this phenomenon from archaeological pigments. It was encountered with two samples found in excavation. From its intensity and stability we concluded that Egyptian Blue can be dated using TL. This first and positive result encouraged us to extend the method to other types of mineral pigments synthesized by early man, and to suggest that it may be used for direct dating of ancient murals.

  1. Status of Blue Ridge Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  2. Food habits of blue grouse

    Science.gov (United States)

    Stewart, R.E.

    1944-01-01

    The food habits of Blue Grouse vary from a simple winter diet that is made up predominantly of coniferous needles to a complex diet during the summer months, characterized by great variety of foods including green leaves, fruits and seeds, flowers, animal matter and coniferous needles. The spring and fall, which represent the transition periods between these two, are characterized by feeding habits that are generally intermediate. The diets of the two species of Blue Grouse, Dendrugapus obscurus and Dendragapus juliginosus, are quite similar as far as major types of food are concerned, but they differ considerably in the species that are taken. Such differences reflect differences in the vegetation within the ecologic and geographic ranges occupied by the two species.

  3. Enhanced visible light photocatalytic degradation of eriochrome black T and eosin blue shade in water using tridoped titania decorated on SWCNTs and MWCNTs: Effect of the type of carbon nanotube incorporated

    Energy Technology Data Exchange (ETDEWEB)

    Mamba, G.; Mbianda, X.Y. [Department of Applied Chemistry, University of Johannesburg, Faculty of Science, P.O. Box 17011, Doornfontein, 2028 Johannesburg (South Africa); DST-NRF Centre of Excellence in Strong Materials, School of Physics, University of the Witwatersrand, Private Bag 3, WITS 2050 Johannesburg (South Africa); Mishra, A.K., E-mail: amishra@uj.ac.za [Department of Applied Chemistry, University of Johannesburg, Faculty of Science, P.O. Box 17011, Doornfontein, 2028 Johannesburg (South Africa); DST-NRF Centre of Excellence in Strong Materials, School of Physics, University of the Witwatersrand, Private Bag 3, WITS 2050 Johannesburg (South Africa)

    2015-01-15

    Oxidised single walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) were each incorporated into a neodymium, nitrogen and sulphur tridoped TiO{sub 2} (Nd,N,S–TiO{sub 2}) to form composite photocatalysts: SWCNT/Nd,N,S–TiO{sub 2} and MWCNT/Nd,N,S–TiO{sub 2}. The fabricated composite photocatalysts were exploited for the photocatalytic degradation of eriochrome black T (EBT) and eosin blue shade (EBS) from single and mixed dye solutions. Incorporation of the carbon nanotubes significantly improved visible light response and the photocatalytic activity of the composites compared to MWCNT/TiO{sub 2}, SWCNT/TiO{sub 2} and tridoped TiO{sub 2}. The SWCNTs incorporating photocatalyst displayed superior photocatalytic activity over its MWCNTs incorporating counterpart. From single dye solutions degradation studies, the SWCNT/Nd,N,S–TiO{sub 2} reached maximum degradation efficiencies of 96.9% and 89.2% for EBS and EBT, respectively. Similarly, maximum degradation efficiencies of 61.4% and 54.1% were recorded from mixed dye solutions using SWCNT/Nd,N,S–TiO{sub 2}, for EBS and EBT, respectively. First order kinetics studies revealed that EBS is degraded faster than EBT both from single and mixed dye solutions. Total organic carbon (TOC) analyses suggest a relatively high degree of complete mineralisation of both EBS (73.6% TOC removal) and EBT (66.2% TOC removal). The SWCNT/Nd,N,S–TiO{sub 2} composite photocatalyst displayed sufficient stability (88.8% EBS removal) after being reused for five times. - Highlights: • SWCNT/Nd,N,S–TiO{sub 2} and MWCNT/Nd,N,S–TiO{sub 2} were prepared via sol–gel method. • EBS and EBT degradation was studied in single and mixed dye solution. • SWCNT/Nd,N,S–TiO{sub 2} displayed higher photocatalytic activity than MWCNT/Nd,N,S–TiO{sub 2}. • Relatively high TOC removal for EBS and EBT by SWCNT/Nd,N,S–TiO{sub 2}. • SWCNT/Nd,N,S–TiO{sub 2} displayed good stability for reuse.

  4. Enhanced visible light photocatalytic degradation of eriochrome black T and eosin blue shade in water using tridoped titania decorated on SWCNTs and MWCNTs: Effect of the type of carbon nanotube incorporated

    International Nuclear Information System (INIS)

    Oxidised single walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) were each incorporated into a neodymium, nitrogen and sulphur tridoped TiO2 (Nd,N,S–TiO2) to form composite photocatalysts: SWCNT/Nd,N,S–TiO2 and MWCNT/Nd,N,S–TiO2. The fabricated composite photocatalysts were exploited for the photocatalytic degradation of eriochrome black T (EBT) and eosin blue shade (EBS) from single and mixed dye solutions. Incorporation of the carbon nanotubes significantly improved visible light response and the photocatalytic activity of the composites compared to MWCNT/TiO2, SWCNT/TiO2 and tridoped TiO2. The SWCNTs incorporating photocatalyst displayed superior photocatalytic activity over its MWCNTs incorporating counterpart. From single dye solutions degradation studies, the SWCNT/Nd,N,S–TiO2 reached maximum degradation efficiencies of 96.9% and 89.2% for EBS and EBT, respectively. Similarly, maximum degradation efficiencies of 61.4% and 54.1% were recorded from mixed dye solutions using SWCNT/Nd,N,S–TiO2, for EBS and EBT, respectively. First order kinetics studies revealed that EBS is degraded faster than EBT both from single and mixed dye solutions. Total organic carbon (TOC) analyses suggest a relatively high degree of complete mineralisation of both EBS (73.6% TOC removal) and EBT (66.2% TOC removal). The SWCNT/Nd,N,S–TiO2 composite photocatalyst displayed sufficient stability (88.8% EBS removal) after being reused for five times. - Highlights: • SWCNT/Nd,N,S–TiO2 and MWCNT/Nd,N,S–TiO2 were prepared via sol–gel method. • EBS and EBT degradation was studied in single and mixed dye solution. • SWCNT/Nd,N,S–TiO2 displayed higher photocatalytic activity than MWCNT/Nd,N,S–TiO2. • Relatively high TOC removal for EBS and EBT by SWCNT/Nd,N,S–TiO2. • SWCNT/Nd,N,S–TiO2 displayed good stability for reuse

  5. Models of Individual Blue Stragglers

    CERN Document Server

    Sills, Alison

    2014-01-01

    This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar collisions retain memory of their parent stars and are not fully mixed. Very high initial rotation rates must be reduced by an unknown process to allow the stars to collapse to the main sequence. The more massive collision products have shorter lifetimes than normal stars of the same mass, while products between low mass stars are long-lived and look very much like normal stars of their mass. Mass transfer can result in a merger, or can produce another binary system with a blue straggler and the remnant of the original primary. The products of binary mass transfer cover a larger portion of the colour-magnitude diagram than collision products for two reasons: there are more possible configurations which produce blue stragglers, and there are differing contributions to the blended ...

  6. Models of Individual Blue Stragglers

    Science.gov (United States)

    Sills, Alison

    This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar collisions retain memory of their parent stars and are not fully mixed. Very high initial rotation rates must be reduced by an unknown process to allow the stars to collapse to the main sequence. The more massive collision products have shorter lifetimes than normal stars of the same mass, while products between low mass stars are long-lived and look very much like normal stars of their mass. Mass transfer can result in a merger, or can produce another binary system with a blue straggler and the remnant of the original primary. The products of binary mass transfer cover a larger portion of the colour-magnitude diagram than collision products for two reasons: there are more possible configurations which produce blue stragglers, and there are differing contributions to the blended light of the system. The effects of rotation may be substantial in both collision and merger products, and could result in significant mixing unless angular momentum is lost shortly after the formation event. Surface abundances may provide ways to distinguish between the formation mechanisms, but care must be taken to model the various mixing mechanisms properly before drawing strong conclusions. Avenues for future work are outlined.

  7. Clinical application of sentinel lymph node biopsy under the guidance of contrast-enhanced ultrasound pins methylene blue in patients with breast cancer%超声造影结合亚甲蓝定位在乳腺癌前哨淋巴结活检中的应用

    Institute of Scientific and Technical Information of China (English)

    胡慧; 韦伟; 孙德胜; 刘荫华

    2013-01-01

    Objective To explore the application feasibility of contrast-emhanced ultrasound (CEUS) plus methylene blue in sentinel lymph node biopsy (SLNB) for breast cancer and determine the ultrasonographic features of sentinel lymph node (SLN).Methods The microbubbles of SonoVue were injected subcutaneously and intradermally into tumor side of areola.The images were observed to record the size,number,lymphatic door,aspect ratio,enhanced time and enhanced mode of SLN.Methylene blue was injected into SLN under the guidance of ultrasound.The marked SLNs were dissected for pathological examinations.Based upon the results,the specimens were divided into SLN metastasis and SLN nonmetastasis groups.Results A total of 34 breast cancer patients were recruited.Among them,SLN was detected preoperatively in 31 patients by CEUS and the rate was 91.2%.And the postoperative results showed that 14 were confirmed positive (metastasis group) and 17 negative (non-metastasis group).The sensitivity,specificity,accuracy and false negative rate of CEUS for detecting SLNs were 93.3% (14/15),100%(16/16),96.8% (30/31) and 6.7% (1/15) respectively.The model of stepwise regression analysis showed that lymphatic door,aspect ratio and enhanced mode were helpful to differentiate SLN metastasis and SLN nonmetastasis groups.Conclusions SLNB under the guidance of CEUS plus methylene blue offer prompt and accurate localization with a lower cost.It may enhance the detection rate of SLNB in breast cancer.%目的 探讨超声造影结合亚甲蓝行乳腺癌前哨淋巴结活检(SLNB)的可行性以及超声造影图像特征.方法 2011年10月至2012年5月北京大学深圳医院对34例乳腺癌患者在患侧乳晕区皮内及皮下注射造影剂,观察前哨淋巴结(SLN)超声造影增强情况,记录SLN大小、数量、淋巴门结构、纵横比、增强时间及增强模式;在B超声引导下对确定的SLN进行亚甲蓝定位后切除SLN,行病理检查,并根据有无肿瘤转移

  8. Fat necrosis in the breast from methylene blue dye injection

    OpenAIRE

    Ha, Kelli Y.; Parish, David; Hamilton, Raynal; Wang, Jean C.

    2013-01-01

    Sentinel lymph node biopsy has become the standard of clinical care in staging axillary lymph nodes for breast carcinoma. While deemed safe and effective, methylene blue dye has been associated with infection, fibrosis, and skin and fat necrosis. The variable appearance of surgical dye-related fibrosis and fat necrosis on imaging studies poses a challenge to both radiologists and clinicians. We present a patient in whom a new enhancing lesion was visualized on follow-up magnetic resonance ima...

  9. Hoe hoger de haze bij diffuus glas, hoe hoger de meerproductie (interview met Jan Janse en Sonny Moerenhout)

    NARCIS (Netherlands)

    Kierkels, T.; Janse, J.; Moerenhout, S.

    2012-01-01

    Een vroege komkommerteelt onder diffuus glas gaf vanaf het begin een grotere opbrengst dan onder gewoon glas. Jan Janse van Wageningen UR Glastuinbouw durft na de reeks proeven in de afgelopen jaren de conclusie te trekken: hoe hoger de haze, hoe hoger de meerproductie. Dus ook in een vroege teelt.

  10. Investigating the impact of haze on cloud detection of passive satellite by comparing MODIS, CloudSat and CALIPSO

    Science.gov (United States)

    Gong, W.; Mao, F.

    2015-12-01

    The cloud detection algorithm for passive sensors is usually based on a fuzzy logic system with thresholds determined from previous observations. In recent years, haze and high aerosol concentrations with high AOD occur frequently in China and may critically impact the accuracy of the MODIS cloud detection. Thus, we comprehensively explore this impact by comparing the results from MODIS/Aqua (passive sensor), CALIOP/CALIPSO (lidar sensor), and CPR/CloudSat (microwave sensor) of the A-Train suite of instruments using an averaged AOD as an index for an aerosol concentration value. Case studies concerning the comparison of the three sensors indicate that MODIS cloud detection is reduced during haze events. In addition, statistical studies show that an increase in AOD creates an increase in the percentage of uncertain flags and a decrease in hit rate, a consistency index between consecutive sets of cloud retrievals. Therefore, we can conclude that the ability of MODIS cloud detection is weakened by large concentrations of aerosols. This suggests that use of the MODIS cloud mask, and derived higher level products, in situations with haze requires caution. Further improvement of this retrieval algorithm, is desired as haze studies based on MODIS products are of great interest in a number of related fields.

  11. Inflation and alternatives with blue tensor spectra

    International Nuclear Information System (INIS)

    We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe cosmology models, including null energy condition violating inflation, inflation with general initial conditions, and string gas cosmology, etc. For the simplest G-inflation, blue tensor spectrum also implies blue scalar spectrum. In general, the inflation models with blue tensor spectra indicate large non-Gaussianities. On the other hand, string gas cosmology predicts blue tensor spectrum with highly Gaussian fluctuations. If further experiments do confirm the blue tensor spectrum, non-Gaussianity becomes a distinguishing test between inflation and alternatives

  12. Localized Eruptive Blue Nevi after Herpes Zoster

    Science.gov (United States)

    Colson, Fany; Arrese, Jorge E.; Nikkels, Arjen F.

    2016-01-01

    A 52-year-old White man presented with a dozen small, well-restricted, punctiform, asymptomatic, blue-gray macules on the left shoulder. A few months earlier, he had been treated with oral acyclovir for herpes zoster (HZ) affecting the left C7–C8 dermatomes. All the blue macules appeared over a short period of time and then remained stable. The patient had not experienced any previous trauma or had tattooing in this anatomical region. The clinical diagnosis suggested blue nevi. Dermatoscopy revealed small, well-limited, dark-blue, compact, homogeneous areas evoking dermal blue nevi. An excisional biopsy was performed and the histological examination confirmed a blue nevus. As far as we are aware of, this is the first report of eruptive blue nevi following HZ, and it should be included in the differential diagnosis of zosteriform dermatoses responding to an isotopic pathway. In addition, a brief review concerning eruptive nevi is presented. PMID:27462219

  13. The variation of chemical characteristics of PM2.5 and PM10 and formation causes during two haze pollution events in urban Beijing, China

    Science.gov (United States)

    Gao, Jiajia; Tian, Hezhong; Cheng, Ke; Lu, Long; Zheng, Mei; Wang, Shuxiao; Hao, Jiming; Wang, Kun; Hua, Shenbing; Zhu, Chuanyong; Wang, Yong

    2015-04-01

    Airborne particles in urban Beijing during haze days and normal days were collected and analyzed in the autumn and winter seasons to reveal the chemical characteristics variations of air pollution. The air quality in haze days was substantially worse than that in normal days. Both the relatively low wind speed and high relative humidity were in favor of the accumulation of pollution species and new formation of secondary PM2.5 in the atmosphere. Elevated concentrations of elements and water-soluble inorganic ions were found on haze days for both PM10 and PM2.5. Particularly, the crustal element, such as Fe, in both PM10 and PM2.5 were substantially higher in autumn normal days and winter haze days than those in autumn haze days and winter normal days, indicating that the abundance of Fe in autumn haze days mainly be originated from crustal dust while in winter haze days it might be primarily emitted from anthropogenic sources (iron and steel smelting) instead of road dust. Secondary ion species (SO42-, NO3-, NH4+) in particles were generated much more during haze episodes, and contributed a higher proportion in PM2.5 than in PM10 during the two sampling periods. Moreover, HYSPLIT model was used to explain the possible transport of airborne particles from distant sources. By comparing with south-type trajectory, west-type trajectory entrained larger amounts of primary crustal pollutants, while, south-type trajectory was comprised of a higher mass of anthropogenic pollution species. The results of back trajectory analysis indicated that the elevated concentration of aerosol and its chemical components during haze days might be caused by the integrated effects of accumulation under stagnant meteorological condition and the transport emissions of pollutants from anthropogenic sources surrounding Beijing city.

  14. Characteristics and formation mechanism of continuous hazes in China: a case study during the autumn of 2014 in the North China Plain

    Science.gov (United States)

    Yang, Y. R.; Liu, X. G.; Qu, Y.; An, J. L.; Jiang, R.; Zhang, Y. H.; Sun, Y. L.; Wu, Z. J.; Zhang, F.; Xu, W. Q.; Ma, Q. X.

    2015-07-01

    Four extreme haze episodes occurred in October 2014 in the North China Plain (NCP). To clarify the formation mechanism of hazes in autumn, strengthened observations were conducted in Beijing from 5 October to 2 November. The meteorological parameters, satellite data, chemical compositions and optical properties of aerosols were obtained. The hazes originated from the NCP, developing in the southwest and northeast directions, with the highest concentration of PM2.5 of 469 μg m-3 in Beijing. The NCP was dominated by a weak high pressure system during the haze episode, which resulted in low surface wind speed and relatively stagnant weather. Moreover, the wind slowed down around Beijing city. The secondary aerosols NO3- was always higher than that of SO42-, which indicated the motor vehicles played a more important part in the hazes in October 2014, even though the oxidation rate from SO2 to SO42- was faster than that of NOx to NO3-. Sudden increases of the concentrations of organic matter, Cl- and BC (black carbon) before each haze episode implied that regional transport of pollutants by biomass burning was important for haze formation during autumn. A satellite map of fire points and the backward trajectories of the air masses also indicated this pollution source. The distinct decrease in the PBL (planetary boundary layer) height during four haze episodes restrained the vertical dispersion of the air pollutants. Water vapor also played a vital role in the formation of hazes by accelerating the chemical transformation of secondary pollutants, leading to hygroscopic growth of aerosols and altering the thermal balance of the atmosphere.

  15. Characteristics and formation mechanism of continuous extreme hazes in China: a case study in autumn of 2014 in the North China Plain

    Science.gov (United States)

    Yang, Y. R.; Liu, X. G.; Qu, Y.; An, J. L.; Jiang, R.; Zhang, Y. H.; Sun, Y. L.; Wu, Z. J.; Zhang, F.; Xu, W. Q.; Ma, X. Q.

    2015-04-01

    Four extreme haze episodes occurred in October 2014 in the North China Plain (NCP). To clarify the formation mechanism of hazes in the autumn, strengthened observations were conducted in Beijing from 5 October to 2 November. The meteorological parameters, satellite data, chemical compositions and optical properties of aerosols were obtained. The hazes originated from NCP, developing in the southwest and northeast directions, with the highest concentration of PM2.5 of 469 μg m-3 in Beijing. NCP was dominated by a weak high pressure system during the haze episode, which resulted in low surface wind speed and relatively stagnant weather. Moreover, the wind slowed down around Beijing city. The secondary aerosols NO3- was always higher than that of SO42-, which indicated the motor vehicles played a more important part in the hazes in October 2014, even though the oxidation rate from SO2 to SO42- was faster than that of NOx to NO3-. Sudden increases of the concentrations of organic matter, Cl- and BC (Black carbon) before each haze episode implied that regional transport of pollutants by biomass burning was important for haze formation during the autumn. A satellite map of fire points and the backward trajectories of the air masses also indicated this pollution source. The distinct decrease in the PBL (planetary boundary layer) height during four haze episodes restrained the vertical dispersion of the air pollutants. Water vapor also played a vital role in the formation of hazes by accelerating the chemical transformation of secondary pollutants, leading to hygroscopic growth of aerosols and altering the thermal balance of the atmosphere.

  16. Study on an Air Quality Evaluation Model for Beijing City Under Haze-Fog Pollution Based on New Ambient Air Quality Standards

    OpenAIRE

    Li Li(State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China); Dong-Jun Liu

    2014-01-01

    Since 2012, China has been facing haze-fog weather conditions, and haze-fog pollution and PM2.5 have become hot topics. It is very necessary to evaluate and analyze the ecological status of the air environment of China, which is of great significance for environmental protection measures. In this study the current situation of haze-fog pollution in China was analyzed first, and the new Ambient Air Quality Standards were introduced. For the issue of air quality evaluation, a comprehensive eval...

  17. Study on governance of water resources and haze pollution%水资源与雾霾污染治理研究

    Institute of Scientific and Technical Information of China (English)

    张春华

    2015-01-01

    近年来,随着雾霾的频繁发生,水资源的污染更加严重。在阐述雾霾对水资源影响的基础上,提出了水资源与雾霾污染的同步治理。%In recent years, pollution of water resources is more serious with the frequent occurrence of haze, through the analy-sis of influence of haze on water resources, we suggest the simultaneous governance of water resources and haze pollution.

  18. Evolution process and sources of ambient volatile organic compounds during a severe haze event in Beijing, China.

    Science.gov (United States)

    Wu, Rongrong; Li, Jing; Hao, Yufang; Li, Yaqi; Zeng, Limin; Xie, Shaodong

    2016-08-01

    108 ambient volatile organic compounds (VOCs) were measured continuously at a time resolution of an hour using an online gas chromatography-frame ionization detector/mass spectrometry (GC-FID/MS) in October 2014 in Beijing, and positive matrix factorization (PMF) was performed with online data. The evolution process and causes for high levels of VOCs during a haze event were investigated through comprehensive analysis. Results show that mixing ratios of VOCs during the haze event (89.29 ppbv) were 2 to 5 times as that in non-haze days, There was a distinct accumulation process of VOCs at the beginning of the haze event, and the mixing ratios of VOCs maintained at the high levels until to the end of pollution when the mixing ratios of ambient VOCs recovered to the normal concentration levels in a few hours. Some reactive and toxic species increased remarkably as well, which indicates a potential health risk to the public in terms of VOCs. Eight sources were resolved by PMF, and results revealed gasoline exhaust was the largest contributor (32-46%) to the ambient VOCs in Beijing. Emissions of gasoline exhaust surged from 13.46 to 40.36 ppbv, with a similar variation pattern to total VOCs, indicating that high levels of VOCs were largely driven to by expanded vehicular emissions. Emissions of biomass burning also increased noticeably (from 2.32 to 11.12 ppbv), and backward trajectories analysis indicated regional transport of biomass burning emissions. Our findings suggested that extremely high levels of VOCs during the haze event was primarily attributed to vehicular emissions, biomass burning and regional transport, as well as stationary synoptic conditions. PMID:27093124

  19. Long-term trend of haze pollution and impact of particulate matter in the Yangtze River Delta, China

    International Nuclear Information System (INIS)

    Haze pollution caused by heavy particulate matter (PM) loading brings significant damage in eastern China. Long-term monitoring from 1980 to 2011 and 1-year field measurement in 2011–2012 are used for investigating visibility variation and the impact of PM pollution for the Yangtze River Delta (YRD). It was found that visual range in the YRD endured a sharp reduction from 13.2 km to 10.5 km during 1980–2000. Average mass extinction efficiency (MEE) for inhalable PM (PM10) is 2.25 m2/g in 2001–2011, and extinction coefficient due to PM10 is 207 Mm−1, accounting for 36.2% of total extinction coefficient. MEE of PM2.5 and PM2.5–10 are 4.08 m2/g and 0.58 m2/g, respectively. Extinction coefficient due to PM2.5 and PM2.5–10 is 198 Mm−1 (39.6%) and 20 Mm−1 (4.0%) in 2011–2012. Maximum daily concentration of PM10 and PM2.5 is estimated to be 63 μg/m3 (RH: 73%) and 38 μg/m3 (RH: 70%) to keep visual range above 10 km. Fine particulate matter is the key factor for haze pollution improvement in the YRD area. -- Highlights: •Long-term visual range variation and its causes in the Yangtze River Delta are analyzed. •Quantitative contribution of particulate matter to haze pollution is estimated. •Mass extinction efficiency of PM10, PM2.5, and PM2.5–10 is estimated. -- The long-term variation of haze pollution in the YRD and its cause is investigated and the quantitative contribution of particulate matter to haze pollution is estimated

  20. Spatial distribution of jovian clouds, hazes and colors from Cassini ISS multi-spectral images

    Science.gov (United States)

    Ordonez-Etxeberria, I.; Hueso, R.; Sánchez-Lavega, A.; Pérez-Hoyos, S.

    2016-03-01

    The Cassini spacecraft made a gravity assist flyby of Jupiter in December 2000. The Imaging Science Subsystem (ISS) acquired images of the planet that covered the visual range with filters sensitive to the distribution of clouds and hazes, their altitudes and color. We use a selection of these images to build high-resolution cylindrical maps of the planet in 9 wavelengths. We explore the spatial distribution of the planet reflectivity examining the distribution of color and altitudes of hazes as well as their relation. A variety of analyses is presented: (a) Principal Component Analysis (PCA); (b) color-altitude indices; and (c) chromaticity diagrams (for a quantitative characterization of Jupiter "true" colors as they would be perceived by a human observer). PCA of the full dataset indicates that six components are required to explain the data. These components are likely related to the distribution of cloud opacity at the main cloud, the distribution of two types of hazes, two chromophores or coloring processes and the distribution of convective storms. While the distribution of a single chromophore can explain most of the color variations in the atmosphere, a second coloring agent is required to explain the brownish cyclones in the North Equatorial Belt (NEB). This second colorant could be caused by a different chromophore or by the same chromophore located in structures deeper in the atmosphere. Color indices separate different dynamical regions where cloud color and altitude are correlated from those where they are not. The Great Red Spot (GRS) appears as a well separated region in terms of its position in a global color-altitude scatter diagram and different families of vortices are examined, including the red cyclones which are located deeper in the atmosphere. Finally, a chromaticity diagram of Jupiter nearly true color images quantifies the color variations in Jupiter's clouds from the perspective of a visual observer and helps to quantify how different

  1. Laboratory Investigations of Titan Haze Formation: Characterization of Gas Phase and Particle Phase Nitrogen

    Science.gov (United States)

    Horst, Sarah; Yoon, Heidi; Li, Rui; deGouw, Joost; Tolbert, Margaret

    2014-11-01

    Prior to the arrival of the Cassini-Huygens spacecraft, aerosol production in Titan’s atmosphere was believed to begin in the stratosphere where chemical processes are predominantly initiated by far ultraviolet (FUV) radiation. However, the discovery of very heavy ions, coupled with Cassini Ultraviolet Imaging Spectrograph (UVIS) occultation measurements that show haze absorption up to 1000 km altitude (Liang et al., 2007), indicates that haze formation initiates in the thermosphere. The energy environment of the thermosphere is significantly different from the stratosphere; in particular there is a greater flux of extreme ultraviolet (EUV) photons and energetic particles available to initiate chemical reactions, including the destruction of N2, in the upper atmosphere. The discovery of previously unpredicted nitrogen species in measurements of Titan’s atmosphere by the Cassini Ion and Neutral Mass Spectrometer (INMS) indicates that nitrogen participates in the chemistry to a much greater extent than was appreciated before Cassini (Vuitton et al., 2007). Additionally, measurements obtained by the Aerosol Collector Pyrolyzer (ACP) carried by Huygens to Titan’s surface may indicate that Titan’s aerosols contain significant amounts of nitrogen (Israël et al., 2005, 2006). The degree of nitrogen incorporation in the haze particles is important for understanding the diversity of molecules that may be present in Titan’s atmosphere and on its surface. We have conducted a series of Titan atmosphere simulation experiments using either spark discharge (tesla coil) or FUV photons (deuterium lamp) to initiate chemistry in CH4/N2 gas mixtures ranging from 0.01% CH4/99.99% N2 to 10% CH4/90% N2. We obtained in situ measurements using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) to measure the particle composition as a function of particle size and a proton-transfer ion-trap mass spectrometer (PIT-MS) to measure the composition of gas phase

  2. The 2013 severe haze over southern Hebei, China: model evaluation, source apportionment, and policy implications

    Science.gov (United States)

    Wang, L. T.; Wei, Z.; Yang, J.; Zhang, Y.; Zhang, F. F.; Su, J.; Meng, C. C.; Zhang, Q.

    2014-03-01

    Extremely severe and persistent haze occurred in January 2013 over eastern and northern China. The record-breaking high concentrations of fine particulate matter (PM2.5) of more than 700 μg m-3 on hourly average and the persistence of the episodes have raised widespread, considerable public concerns. During that period, 7 of the top 10 polluted cities in China were within the Hebei Province. The three cities in southern Hebei (Shijiazhuang, Xingtai, and Handan) have been listed as the top three polluted cities according to the statistics for the first half of the year 2013. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to simulate the 2013 severe winter regional hazes in East Asia and northern China at horizontal grid resolutions of 36 and 12 km, respectively, using the Multi-resolution Emission Inventory for China (MEIC). The source contributions of major source regions and sectors to PM2.5 concentrations in the three most polluted cities in southern Hebei are quantified by aiming at the understanding of the sources of the severe haze pollution in this region, and the results are compared with December 2007, the haziest month in the period 2001-2010. Model evaluation against meteorological and air quality observations indicates an overall acceptable performance and the model tends to underpredict PM2.5 and coarse particulate matter (PM10) concentrations during the extremely polluted episodes. The MEIC inventory is proven to be a good estimation in terms of total emissions of cities but uncertainties exist in the spatial allocations of emissions into fine grid resolutions within cities. The source apportionment shows that emissions from northern Hebei and the Beijing-Tianjin city cluster are two major regional contributors to the pollution in January 2013 in Shijiazhuang, compared with those from Shanxi and northern Hebei for December 2007. For Xingtai and Handan

  3. The 2013 severe haze over the southern Hebei, China: model evaluation, source apportionment, and policy implications

    Science.gov (United States)

    Wang, L. T.; Wei, Z.; Yang, J.; Zhang, Y.; Zhang, F. F.; Su, J.; Meng, C. C.; Zhang, Q.

    2013-11-01

    Extremely severe and persistent haze occurred in January 2013 over the eastern and northern China. The record-breaking high concentrations of fine particulate matter (PM2.5) of more than 700 μg m-3 on hourly average and the persistence of the episodes have raised widespread, considerable public concerns. During that period, seven of the top ten polluted cities in China were within Hebei Province. The three cities in southern Hebei, Shijiazhuang, Xingtai, and Handan, have been listed as the top three polluted cities according to the statistics for the first half year of 2013. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to simulate the 2013 severe winter regional hazes in East Asia and the northern China at horizontal grid resolutions of 36 and 12 km, respectively, using the Multi-resolution Emission Inventory of China (MEIC). The source contributions of major source regions and sectors to PM2.5 concentrations in the three most-polluted cities in southern Hebei are quantified aiming at the understanding of the sources of the severe haze pollution in this region, and the results are compared with December 2007, the haziest month in 2001-2010. Model evaluation against meteorological and air quality observations indicates an overall acceptable performance and the model tends to underpredict PM2.5 and coarse particulate matter (PM10) concentrations during the extremely severe polluted episodes. The MEIC inventory is proved to be a good estimation in terms of total emissions of cities but uncertainties exist in the spatial allocations of emissions into fine grid resolutions within cities. The source apportionment shows that emissions from the northern Hebei and the Beijing-Tianjin city cluster are two major regional contributors to the pollution in January 2013 in Shijiazhuang, comparing with those from Shanxi and the northern Hebei for December 2007. For Xingtai and

  4. Regional Haze

    Science.gov (United States)

    This indicator presents visibility trends measured at 41 locations in National Parks and Wilderness Areas between 1992 and 2008. Visibility impairment is caused by air pollution, especially particulate matter pollution, and limits the distance one can see and degrades the colo...

  5. Blue and UV Semiconductor Lasers

    International Nuclear Information System (INIS)

    Despite many technological difficulties the group III nitrides: GaN, AlN and InN and their alloys are primary candidates for electro-optical coherent light sources. In the recent years the research and technology of the nitride based continuous wave (CW) laser diodes (LDs) led to creation of blue-violet coherent light sources of power up to 200 mW. The progress has been attained by using various ways to attack the main obstacles in the technology of these devices such as insufficient size of high quality lattice matched substrates, low p-doping efficiency of Mg acceptor, poor contact to p-type semiconductor and low efficiency of radiative recombination. The two different approaches were used to overcome the substrate problem: hetero-epitaxy and homoepitaxy. Homoepitaxy used high pressure GaN high quality crystals. Heteroepitaxy used sapphire, SiC or GaAs substrates and very sophisticated techniques of reduction of the dislocation density. The low p-doping efficiency by using Mg acceptor is related to creation of Mg - H complexes due to hydrogen presence during the growth of laser diode quantum structures. In addition, Mg acceptor has low efficiency due to its high energy. High Mg concentrations can be obtained by using either MOCVD or ammonia source MBE growth. An alternative route is to use hydrogen-free plasma activated MBE (PA-MBE) method. The recent advances and the prospects of both approaches will be discussed. Solid AlGaInN solution offers a possibility to cover wide spectral range, starting from near UV to blue, green and red. Arsenide based laser diodes (LDs) are efficient coherent red light sources. Therefore, nitride based LDs are considered to be devices of choice for green, blue and UV spectral range. So far only blue and violet laser has been realized. The progress toward green and UV lasers is far less spectacular. The results in all these areas and future prospects will be discussed. (author)

  6. Liquid biofuels from blue biomass

    DEFF Research Database (Denmark)

    Kádár, Zsófia; Jensen, Annette Eva; Bangsø Nielsen, Henrik;

    2011-01-01

    Marine (blue) biomasses, such as macroalgaes, represent a huge unexploited amount of biomass. With their various chemical compositions, macroalgaes can be a potential substrate for food, feed, biomaterials, pharmaceuticals, health care products and also for bioenergy. Algae use seawater as a growth...... medium, light as energy source and they capture CO2 for the synthesis of new organic material, thus can grow on non-agricultural land, without increasing food prices, or using fresh water. Due to all these advantages in addition to very high biomass yield with high carbohydrate content, macroalgaes can...

  7. Spectroscopy of blue stellar objects

    Science.gov (United States)

    Mitchell, K. J.; Warnock, A., III; Nations, H. L.; Barden, S. C.

    1983-01-01

    Spectra have been obtained for the brightest objects from a list of blue stellar objects found in a Palomar Schmidt field centered on Kapteyn Selected Area 28. Four of the objects presented here comprise a complete sample of objects with UV excess and magnitudes brighter than or equal to B = 16.3 mag. The object with the largest UV excess is a previously undiscovered quasar of redshift 0.25 and cataloged B magnitude of 15.6 mag. The object shows some evidence of variability. Spectroscopy for one bright object in a companion field centered on Selected Area 29 is also presented.

  8. Bimodal Distribution of Sulfuric Acid Aerosols in the Upper Haze of Venus

    CERN Document Server

    Gao, Peter; Crisp, David; Bardeen, Charles G; Yung, Yuk L

    2013-01-01

    The upper haze (UH) of Venus is variable on the order of days and it is populated by two particle modes. We use a 1D microphysics and vertical transport model based on the Community Aerosol and Radiation Model for Atmospheres to evaluate whether interaction of upwelled cloud particles and sulfuric acid particles nucleated in situ on meteoric dust are able to generate the two size modes and whether their observed variability are due to cloud top vertical transient winds. Nucleation of photochemically produced sulfuric acid onto polysulfur condensation nuclei generates mode 1 cloud droplets that then diffuse upwards into the UH. Droplets generated in the UH from nucleation of sulfuric acid onto meteoric dust coagulate with the upwelled cloud particles and cannot reproduce the observed bimodal size distribution. The mass transport enabled by cloud top transient winds are able to generate a bimodal size distribution in a time scale consistent with observations. Sedimentation and convection in the middle and lower...

  9. Interventions to reduce individual exposure of elderly individuals and children to haze: a review.

    Science.gov (United States)

    Zhang, Sini; Li, Lingling; Gao, Wei; Wang, Yujie; Yao, Xin

    2016-01-01

    Given rapid economic developments and urbanization over the last few decades, China has experienced frequent haze episodes, which have adverse effects on public health. Children and elderly individuals are more susceptible than the general population to air pollution. In this study, we introduce interventions to reduce the exposure of elderly individuals and children to air pollution during hazy weather. These interventions include avoiding outdoor activities, wearing a dust mask, reducing burning biomass fuels, reducing frying and smoking at home, using an air filtration unit and taking supplemental antioxidants. However, the actual benefits of these measures remain unproven and are unlikely to be adequate. Sustained clean air policies remain the most important and efficient solution to reduce air pollution-related health effects. PMID:26904254

  10. Observing Jupiter's polar stratospheric haze with HST/STIS. An HST White Paper

    CERN Document Server

    Grodent, Denis; Nichols, Jonathan

    2015-01-01

    The purpose of this HST white paper is to demonstrate that it is possible to monitor Jupiter's polar haze with HST/STIS without breaking the ground screening limit for bright objects. This demonstration rests on a thorough simulation of STIS output from an existing image obtained with HST/WFPC2. It is shown that the STIS NUV-MAMA + F25CIII filter assembly provides a count rate per pixel ~11 times smaller than that obtained for one pixel of WFPC2 WF3 CCD + F218W corresponding filter. This ratio is sufficiently large to cope with the bright solar light scattered by Jupiter's atmosphere, which was a lesser concern for WFPC2 CCD safety. These STIS images would provide unprecedented spatial and temporal resolution observations of small-scale stratospheric aerosol structures, possibly associated with Jupiter's complex FUV aurora.

  11. Impact of aerosols on radiation during a heavy haze event in Beijing

    International Nuclear Information System (INIS)

    In order to understand the influence of anthropogenic aerosols on radiation in the urban boundary layer, we measured atmospheric aerosol mass concentrations (PM10 and PM2.5), integrated solar radiation, wind and temperature at different layers of a 325-m iron tower. A typical heavy haze process occurring during the period of October 2004 was analyzed. It is observed that the inversion layer and the weak wind was the most important factor causing the accumulation of pollutants. The results show that the PM10 concentrations under polluted day conditions is about 84 times (537.1μgm−3) higher than those on clear weather conditions (6.4μgm−3). The difference in the solar radiation between 2m and 280m became smaller (93.07 Wm−2 to 16.07 Wm−2) when pollution turned heavy, while the attenuations rate changed large (16.76% to 20.96%)

  12. Understanding the Atmosphere of 51 Eri b: Do Photochemical Hazes Cloud the Planets Spectrum?

    Science.gov (United States)

    Marley, Mark Scott; Zahnle, Kevin; Moses, J.; Morley, C.

    2015-01-01

    The first young giant planet to be discovered by the Gemini Planet Imager was the (is) approximately 2MJ planet 51 Eri b. This approximately 20 Myr old young Jupiter is the first directly imaged planet to show unmistakable methane in H band. To constrain the planet's mass, atmospheric temperature, and composition, the GPI J and H band spectra as well as some limited photometric points were compared to the predictions of substellar atmosphere models. The best fitting models reported in the discovery paper (Macintosh et al. 2015) relied upon a combination of clear and cloudy atmospheric columns to reproduce the data. However for an object as cool as 700 K, the origin of the cloud coverage is somewhat puzzling, as the global silicate and iron clouds would be expected to have sunk well below the photosphere by this effective temperature. While strong vertical mixing in these low gravity atmospheres remains a plausible explanation, we have explored whether atmospheric photochemistry, driven by the UV flux from the primary star, may yield hazes that also influence the observed spectrum of the planet. To explore this possibility we have modeled the atmospheric photochemistry of 51 Eri b using two state-of-the-art photochemical models, both capable of predicting yields of complex hydrocarbons under various atmospheric conditions. In our presentation we will summarize the modeling approach employed to characterize 51 Eri b, explaining constraints on the planet's effective temperature, gravity, and atmospheric composition and also present results of our studies of atmospheric photochemistry. We will discuss whether photochemical hazes could indeed be responsible for the particulate opacity that apparently sculpts the spectrum of the planet.

  13. [Exploring the Severe Haze in Beijing During December, 2015: Pollution Process and Emissions Variation].

    Science.gov (United States)

    Xue, Yi-feng; Zhou, Zhen; Nie, Teng; Pan, Tao; Qi, Jun; Nie, Lei; Wang, Zhan-shan; Li, Yun-ting; Li, Xue-feng; Tian, He-zhong

    2016-05-15

    Severe haze episodes shrouded Beijing and its surrounding regions again during December, 2015, causing major environmental and health problems. Beijing authorities had launched two red alerts for atmospheric heavy pollution in this period, adopted a series of emergency control measures to reduce the emissions from major pollution sources. To better understand the pollution process and emissions variation during these extreme pollution events, we performed a model-assisted analysis of the hourly observation data of PM₂.₅, and meteorological parameters combined with the emissions variation of pollution sources. The synthetic analysis indicated that: (1) Compared with the same period of last year, the emissions of atmospheric pollution sources decreased in December 2015. However, the emission levels of primary pollutants were still rather high, which were the main intrinsic causes for haze episodes, and the unfavorable diffusion conditions represented the important external factor. High source emissions and meteorological factors together led to this heavy air pollution process. (2) Emergency control measures taken by the red alert for heavy air pollution could decrease the pollutants emission by about 36% and the PM₂.₅ concentrations by 11% to 21%. Though the implementation of red alert could not reverse the evolution trend of heavier pollution, it indeed played an active role in mitigation of PM₂.₅ pollution aggravating. (3) Under the heavy pollution weather conditions, air pollutants continued to accumulate in the atmosphere, and the maximum effect by taking emergency measures occurred 48-72 hours after starting the implementation; therefore, the best time for executing emergency measures should be 36-48 hours before the rapid rise of PM₂.₅ concentration, which requires a more powerful demand on the accuracy of air quality forecast. PMID:27506009

  14. Effect of Atmospheric Haze on the Deterioration of Visibility over the Pearl River Delta

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The studies on the effect of atmospheric aerosol on climate and environment are hot issues in the current circle of international science and technology. In recent years the pollution of aerosol is getting worse and worse over the Pearl River Delta. The clouds of aerosol occur all year round, with heavy pollution area located at the western side at the mouth of Pearl River. The haze weather mainly occurs from October to April next year, resulting in visibility deterioration. From the beginning of 1980s, visibility dramatically deteriorated, obviously increasing haze weather, in which there are three big fluctuations, showing the periods of pollutions of dust, sulphate and dust, fine particle from photochemical process and sulphate and dust accompanying with the development of economy respectively. The long-term tendency of visibility caused by fog and light fog does not show a tendency due to human activities or economic development, which mainly shows the interannual and interdecadal variation of climate. The deterioration of visibility has close relation to the fine particles over Pearl River Delta, with half of PM10 overpass the limited value set by national second graded standard (150μg m-3), meanwhile, all values of PM2.5 overpass the day-mean limited value of American national standard (65μg m-3), especially from October to January next year, monthly mean values of PM2.5 almost reach two times of standard value, indicating the fine particle concentration is very high. The ratio of PM2.5 to PM10 is also very high, reaching 58%-77%, higher especially in dry season than in rainy season. Thus it is the fine particle pollution in aerosol pollution over the Pearl River Delta.Compared with the data of 15 years ago, the ratio of fine particle to aerosol has obviously increased.

  15. Mask quality assurance in cleaning for haze elimination using flexible mask specifications

    Science.gov (United States)

    Otsubo, Kyo; Yamaguchi, Shinji; Arisawa, Yukiyasu; Mukai, Hidefumi; Kotani, Toshiya; Mashita, Hiromitsu; Hashimoto, Hiromitsu; Kamo, Takashi; Tsutsui, Tomohiro; Ikenaga, Osamu

    2007-05-01

    We propose a new method of quality assurance for attenuated phase shifting mask (PSM) using the concept of the flexible mask specifications to extend the life of PSM [1]. The haze on PSM is a major issue for ArF lithography in semiconductor device manufacturing since it causes decline of device yield. PSM irradiated by ArF laser is periodically cleaned before haze is printed on wafer, which is a killer defect. Repetition of cleaning causes great changes of properties, i.e. phase, transmittance. Therefore, the number of times cleaning is performed has been limited by predetermined specifications based on ITRS. In this paper, relaxation of the pass/ fail criteria are studied as one solution to this limitation problem. In order to decide a suitable number of times for cleaning to be performed, we introduce the concept of flexible mask specifications, taking lithography margin into account. Firstly, we obtained mask parameters before cleaning; these parameters were, for instance, phase, transmittance and CD. Secondly, using these parameters, we simulated images of resist pattern exposed on wafer and obtained exposure latitude at desired depth of focus. Thirdly, we simulated mask parameters and exposure latitude when the mask was cleaned several times and obtained correlation between number of times cleaning is performed and exposure latitude. And finally, we estimated suitable pass/ fail criteria of mask parameters and the maximum number of times cleaning should be performed for each mask at the standard exposure latitude. In the above procedure, the maximum number of times cleaning should be performed exceeded that determined in the case of conventional specifications based on ITRS.

  16. High secondary aerosol contribution to particulate pollution during haze events in China

    Science.gov (United States)

    Huang, Ru-Jin; Zhang, Yanlin; Bozzetti, Carlo; Ho, Kin-Fai; Cao, Jun-Ji; Han, Yongming; Daellenbach, Kaspar R.; Slowik, Jay G.; Platt, Stephen M.; Canonaco, Francesco; Zotter, Peter; Wolf, Robert; Pieber, Simone M.; Bruns, Emily A.; Crippa, Monica; Ciarelli, Giancarlo; Piazzalunga, Andrea; Schwikowski, Margit; Abbaszade, Gülcin; Schnelle-Kreis, Jürgen; Zimmermann, Ralf; An, Zhisheng; Szidat, Sönke; Baltensperger, Urs; Haddad, Imad El; Prévôt, André S. H.

    2014-10-01

    Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China. Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.

  17. Atmospheric deposition of 210Po and 210Pb in Malaysian waters during haze events

    International Nuclear Information System (INIS)

    Biogenic burning as forest fire phenomena occurring from April to August each year in the Sumatra and Borneo islands are major sources of biogenic uranium–thorium decay series in marine systems. 30 samples were collected during the Ekspedisi Pelayaran Saintifik Perdana 2009 cruise (EPSP 2009 cruise) between 12th June and 1st August 2009 from the Straits of Malacca to the Sulu and Sulawesi Seas to study the effect of haze and the monsoon season on the deposition rate of 210Po and 210Pb in Malaysian waters. All samples were spiked with 1 ml of lead [Pb(NO3)2; 25 mg ml-1] and 0.05 ml of Polonium-209 tracer (26.08 dpm ml-1). 210Po activity was determined by auto plating onto silver foil and counting using an alpha spectrometry system (Canberra model Alpha Analyst with a silicon-surface barrier detector). Lead that was collected via electrodeposition, formed lead sulphate (PbSO4) precipitation. This precipitate was wrapped onto plastic discs and counted for 210Pb beta activity using a gross alpha-beta counting system (Tennelec model LB-5100 low background gas-flowing anti-coincidence alpha/beta counter) after 1 month to allow bismuth ingrowths. The range of 210Po activities varied between 51.08 ± 15.1 and 742.08 ± 220.34 Bq/kg, whereas the activity of 210Pb ranged from 31.10 ± 4.20 to 880.23 ± 123.86 Bq/kg and 210Po/210Pb ratio value varied between sampling stations from 0.19 to 13.77. The contents of 210Po were also statistically positively correlated with the amount of total suspended particulate especially those recorded during heavy haze period events. (author)

  18. Blue-sheet instability of Schwarzschild wormholes

    International Nuclear Information System (INIS)

    The Schwarzschild wormhole geometry is found to be unstable against the gravitational effects of accumulated, blue-shifted matter and radiation, or ''blue sheets'', accreting along the past horizons. This is shown by constructing a simple model of a wormhole geometry featuring such blue sheets and manifesting their effects. In this model the blue sheets are treated as null delta-function surface layers, and we derive here general conditions for matching spacetime geometries across such null hypersurfaces of discontinuity. These junction conditions are then applied to the construction of the wormhole model. The wormhole evolution depicted in this model shows that the gravitational focussing produced by the blue-sheet mass-energy eventually encloses the blue sheets and past horizons within future horizons, leaving a black-hole geometry. These effects limit emission processes from the region of a wormhole's past singularity into the external universe, and severely restrict the possible role of wormholes in cosmological contexts. (author)

  19. Aircraft Observations into the Characteristics of Biomass Burning Instigated 'Regional Haze' Over the Amazon during the SAMBBA Campaign

    Science.gov (United States)

    Darbyshire, Eoghan

    2013-04-01

    E. J. N. Darbyshire, J. D. Allan, M. Flynn, W. T. Morgan, A. Hodgson, B. T. Johnson, J. M. Haywood, K. Longo, P. Artaxo and H. Coe Aerosols associated with large scale Biomass Burning (BB) impact upon weather and climate at global and regional scales. However, quantitative evaluation of these effects is impeded by i) a limited understanding of BB processes and ii) a lack of quantitative knowledge of precise BB aerosol physiochemical characteristics, thus resulting in large model uncertainties. One region where these uncertainties are especially manifest is the Amazon Basin (AzB). Intense and widespread burning results in high atmospheric loadings of BB aerosol, which over the course of the dry season develops into a so-called 'regional haze'. This cloaks the AzB in a complex and inhomogeneous mix of BB emissions, characterized by large Aerosol Optical Depths (>1), low visibility and poor air quality. This haze has a substantial impact on the radiation budget over the AzB through direct scattering/absorption and indirect cloud microphysics effects. In order to best constrain the model uncertainties, and given the scale of the AzB earth-atmosphere system, an intensive observation campaign by multiple international institutions was instigated in the South American Biomass Burning Analyses (SAMBBA) project. The findings reported here are from the SAMBBA aircraft campaign, conducted during the 2012 dry season using the large UK research aircraft (FAAM BAe-146). The dense (high AOD), persistent haze expected throughout the campaign was only present for the first five or so days, due to removal via washout/transportation associated with large storms. For the remaining period, a haze was present but much reduced in area and intensity (mostly AOD's rainforest in Rhondonia and Cerrado agricultural fires in Mato Grosso. Thus, the ten (of twenty) SAMMBA flights that encountered haze, sampled from a diversity of haze types. The haze was sampled using the standard

  20. Transmission spectroscopy of HAT-P-32b with the LBT: confirmation of clouds/hazes in the planetary atmosphere

    Science.gov (United States)

    Mallonn, M.; Strassmeier, K. G.

    2016-05-01

    Aims: Spectroscopic observations of a transit event of an extrasolar planet offer the opportunity to study the composition of the planetary atmosphere. This can be done with comparably little telescope time using a low-resolution multi-object spectrograph at a large aperture telescope. We observed a transit of the inflated hot Jupiter HAT-P-32b with the Multi-Object Double Spectrograph at the Large Binocular Telescope to characterize its atmosphere from 3300 to 10 000 Å. Methods: A time series of target and reference star spectra was binned in two broad-band wavelength channels, from which differential transit light curves were constructed. These broad-band light curves were used to confirm previous transit parameter determinations. To derive the planetary transmission spectrum with a resolution of R ~ 60, we created a chromatic set of 62 narrow-band light curves. The spectrum was corrected for the third light of a nearby M star. Additionally, we undertook a photometric monitoring campaign of the host star to correct for the influence of starspots. Results: The transmission spectrum of HAT-P-32b shows no pressure-broadened absorption features from Na and K, which is interpreted by the presence of clouds or hazes in the planetary atmosphere. This result is in agreement with previous studies on the same planet. The presence of TiO in gas phase could be ruled out. We find a 2.8σ indication of increased absorption in the line core of potassium (K I 7699 Å). No narrow absorption features of Na and Hα were detected. Furthermore, tentative indications were found for a slope of increasing opacity toward blue wavelengths from the near-IR to the near-UV with an amplitude of two scale heights. If confirmed by follow-up observations, it can be explained by aerosols either causing Mie scattering or causing Rayleigh scattering with an aerosol - gas scale height ratio below unity. The host star was found to be photometrically stable within the measurement precision. Based on

  1. Uncovering Blue Diffuse Dwarf Galaxies

    CERN Document Server

    James, Bethan L; Stark, Daniel P; Belokurov, Vasily; Pettini, Max; Olszewski, Edward W

    2014-01-01

    Extremely metal poor (XMP) galaxies are known to be very rare, despite the large numbers of low-mass galaxies predicted by the local galaxy luminosity function. This paper presents a sub-sample of galaxies that were selected via a morphology-based search on SDSS images with the aim of finding these elusive XMP galaxies. By using the recently discovered extremely metal-poor galaxy, Leo P, as a guide, we obtained a collection of faint, blue systems, each with isolated HII regions embedded in a diffuse continuum, that have remained undetected until now. Here we show the first results from optical spectroscopic follow-up observations of 12 of ~100 of these blue, diffuse dwarf (BDD) galaxies yielded by our search algorithm. Oxygen abundances were obtained via the direct method for eight galaxies, and found to be in the range 7.45<12+log(O/H)<8.0, with two galaxies being classified as XMPs. All BDDs were found to currently have a young star-forming population (<10 Myr) and relatively high ionisation parame...

  2. African Music: Source of the Blues

    OpenAIRE

    Bayer, Konrad Sidney

    2010-01-01

    [Abstract] African music is the primary source for the blues. Scholars have supplied ample evidence to support this assertion. However, the African retentions still present in the blues are not immediately apparent. African music and the blues share many similarities, including the predominance of rhythm, the uses of music as social commentary and critique, types of instruments, and musical structure. Slaves brought their culture with them to the New World when they were forcibly taken from t...

  3. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-06-17

    The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf

  4. The Red-Blue Transportation Problem

    OpenAIRE

    Vancroonenburg, Wim; Della Croce, Federico; Goossens, Dries; Spieksma, Frits

    2014-01-01

    This paper considers the Red-Blue Transportation Problem (Red-Blue TP), a generalization of the transportation problem where supply nodes are partitioned into two sets and so-called exclusionary constraints are imposed. We encountered a special case of this problem in a hospital context, where patients need to be assigned to rooms. We establish the problem's complexity, and we compare two integer programming formulations. Furthermore, a maximization variant of Red-Blue TP is presented, for...

  5. After Indonesia’s Ratification: The ASEAN Agreement on Transboundary Haze Pollution and Its Effectiveness As a Regional Environmental Governance Tool

    Directory of Open Access Journals (Sweden)

    Daniel Heilmann

    2015-01-01

    Full Text Available On 20 January 2015 Indonesia deposited its instrument of ratification for the ASEAN Agreement on Transboundary Haze Pollution with the ASEAN Secretariat, becoming the last ASEAN member state to join the treaty. Haze pollution poses a serious health threat to the people of Indonesia, Singapore and Malaysia, and for decades haze pollution has been a highly contentious issue among ASEAN member states. This article argues that Indonesia’s ratification will not be an immediate game changer. The mechanisms of the agreement are too weak to contribute much to a reduction of haze pollution in the region. The agreement is designed according to the ASEAN way: a non-binding approach that is based on the principles of state sovereignty and non-intervention. This makes it unlikely that the agreement itself will bring about change, even now that all ASEAN member states have ratified it.

  6. Rural continental aerosol properties and processes observed during the Hohenpeissenberg Aerosol Characterization Experiment (HAZE2002

    Directory of Open Access Journals (Sweden)

    N. Hock

    2007-06-01

    Full Text Available Detailed investigations of the chemical and microphysical properties of rural continental aerosols were performed during the HAZE2002 experiment, which was conducted in May 2002 at the Meteorological Observatory Hohenpeissenberg (DWD in Southern Germany.

    The online measurement data and techniques included: size-resolved chemical composition of submicron particles by aerosol mass spectrometry (AMS; total particle number concentrations and size distributions over the diameter range of 3 nm to 9 μm (CPC, SMPS, OPC; monoterpenes determined by gas chromatography- ion trap mass spectrometry; OH and H2SO4 determined by atmospheric pressure chemical ionization mass spectrometry (CIMS. Filter sampling and offline analytical techniques were used to determine: fine particle mass (PM2.5, organic, elemental and total carbon in PM2.5 (OC2.5, EC2.5, TC2.5, and selected organic compounds (dicarboxylic acids, polycyclic aromatic hydrocarbons, proteins.

    Overall, the non-refractory components of submicron particles detected by aerosol mass spectrometry (PM1, 6.6±5.4 μg m−3, arithmetic mean and standard deviation accounted for ~62% of PM2.5 determined by filter gravimetry (10.6±4.7 μg m−3. The relative proportions of non-refractory submicron particle components were: 11% ammonium, 19% nitrate, 20% sulfate, and 50% organics (OM1. In spite of strongly changing meteorological conditions and absolute concentration levels of particulate matter (3–13 μg m−3 PM1, OM1 was closely correlated with PM1 (r2=0.9 indicating a near-constant ratio of non-refractory organics and inorganics. In contrast, the ratio of nitrate to sulfate was highly dependent on temperature (14–32°C and relative humidity (20–100%, which could be explained by thermodynamic model calculations of NH3/HNO3/NH4NO3 gas-particle partitioning. From the combination

  7. Variable blue straggler stars in NGC 5466

    International Nuclear Information System (INIS)

    Nine variable blue stragglers have been found in the globular cluster NGC 5466. The six dwarf Cepheids in this cluster coexist in the instability strip with other nonvariable stars. The three eclipsing binaries are among the hottest of the blue stragglers. The hypothesis is discussed that all blue stragglers in this cluster have undergone mass transfer in close binaries. Under this hypothesis, rotation and spin-down play important roles in controlling the evolution of blue stragglers in old clusters and in affecting some of their observational properties. 14 refs

  8. Clinical observation of haze after epipolis laser in situ keratomileusis%Epi-LASIK术后Haze形成的临床观察

    Institute of Scientific and Technical Information of China (English)

    张亚丽; 左天南; 刘蕾; 胡明; 李招娜

    2009-01-01

    央厚度上无统计学差异.结论 EpiLASIK术后Haze发生率及密度均较低,术后是否发生Haze与屈光度数,切削深度和切削率有关.%ncidence and density of Haze in Epi-LASIK.Higher myopia,deeper ablation and higher ablation depth/corneal thickness ratio obviously influenee the Haze formation.

  9. Inhibition of the WNT/β-catenin pathway by fine particulate matter in haze: Roles of metals and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Lee, Kang-Yun; Cao, Jun-Ji; Lee, Chii-Hong; Hsiao, Ta-Chih; Yeh, Chi-Tai; Huynh, Thanh-Tuan; Han, Yong-Ming; Li, Xiang-Dong; Chuang, Kai-Jen; Tian, Linwei; Ho, Kin-Fai; Chuang, Hsiao-Chi

    2015-05-01

    Air pollution might have a great impact on pulmonary health, but biological evidence in response to particulate matter less than 2.5 μm in size (PM2.5) has been lacking. Physicochemical characterization of haze PM2.5 collected from Beijing, Xian and Hong Kong was performed. Biological pathways were identified by proteomic profiling in mouse lungs, suggesting that WNT/β-catenin is important in the response to haze PM2.5. Suppression of β-catenin levels, activation of caspase-3 and alveolar destruction, as well as IL-6, TNF-α and IFN-γ production, were observed in the lungs. The inhibition of β-catenin, TCF4 and cyclin D1 was observed in vitro in response to haze PM2.5. The inhibition of WNT/β-catenin signaling, apoptosis-related results (caspase-3 and alveolar destruction), and inflammation, particularly including caspase-3 and alveolar destruction, were more highly associated with polycyclic aromatic hydrocarbons in haze PM2.5. In conclusion, decreased WNT/β-catenin expression modulated by haze PM2.5 could be involved in alveolar destruction and inflammation during haze episodes.

  10. Application of fault tree approach for the causation mechanism of urban haze in Beijing--Considering the risk events related with exhausts of coal combustion.

    Science.gov (United States)

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Qian, Yu

    2016-02-15

    Haze weather has become a serious environmental pollution problem which occurs in many Chinese cities. One of the most critical factors for the formation of haze weather is the exhausts of coal combustion, thus it is meaningful to figure out the causation mechanism between urban haze and the exhausts of coal combustion. Based on above considerations, the fault tree analysis (FAT) approach was employed for the causation mechanism of urban haze in Beijing by considering the risk events related with the exhausts of coal combustion for the first time. Using this approach, firstly the fault tree of the urban haze causation system connecting with coal combustion exhausts was established; consequently the risk events were discussed and identified; then, the minimal cut sets were successfully determined using Boolean algebra; finally, the structure, probability and critical importance degree analysis of the risk events were completed for the qualitative and quantitative assessment. The study results proved that the FTA was an effective and simple tool for the causation mechanism analysis and risk management of urban haze in China. PMID:26493345

  11. Long-persistence blue phosphors

    Science.gov (United States)

    Yen, William M. (Inventor); Jia, Weiyi (Inventor); Lu, Lizhu (Inventor); Yuan, Huabiao (Inventor)

    2000-01-01

    This invention relates to phosphors including long-persistence blue phosphors. Phosphors of the invention are represented by the general formula: MO . mAl.sub.2 O.sub.3 :Eu.sup.2+,R.sup.3+ wherein m is a number ranging from about 1.6 to about 2.2, M is Sr or a combination of Sr with Ca and Ba or both, R.sup.3+ is a trivalent metal ion or trivalent Bi or a mixture of these trivalent ions, Eu.sup.2+ is present at a level up to about 5 mol % of M, and R.sup.3+ is present at a level up to about 5 mol % of M. Phosphors of this invention include powders, ceramics, single crystals and single crystal fibers. A method of manufacturing improved phosphors and a method of manufacturing single crystal phosphors are also provided.

  12. Ecology of Blue Straggler Stars

    CERN Document Server

    Boffin, H M J; Beccari, G

    2014-01-01

    The existence of blue straggler stars (BSS), which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution, as such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. As such, BSS could just be some quirks but in fact their understanding requires a deep knowledge of many different areas in astronomy, from stellar evolution through cluster dynamics, from chemical abundances to stellar populations. In November 2012, a workshop on this important topic took place at the ESO Chilean headquarters in Santiago. The many topics covered at this workshop were introduced by very comprehensive invited reviews, providing a unique and insightful view on the field. These reviews have now become chapters of the first ever book on BSS.

  13. The O-(Al2) centre in topaz and its relation to the blue colour

    Science.gov (United States)

    da Silva, D. N.; Guedes, K. J.; Pinheiro, M. V. B.; Schweizer, S.; Spaeth, J.-M.; Krambrock, K.

    2005-01-01

    Colour-enhanced blue topaz is one of the most traded gemstones. Naturally very rare, mostly topaz is irradiated by neutrons, electrons, gamma radiation and combinations of them. The colour centre is still not identified. It was speculated that it is related to a Si dangling bond defect occupied by two electrons with spin S = 0. We investigated natural blue as well as colourless topaz from different regions in Brazil by electron paramagnetic resonance (EPR), optical absorption and Raman spectroscopy. The results are compared with neutron and gamma-irradiated blue topaz. By EPR two paramagnetic defects are identified in all samples: (i) the peroxy radical (O2-) measured at room temperature and (ii) an (O-) hole centre interacting with two equivalent Al neighbours measured at low temperature. Blue samples show an absorption band centred at 620 nm which is responsible for the blue colour. From our investigation we find that the O-(Al2) hole centre has nearly the same thermal stability as the optical absorption band. However, we cannot say whether it is responsible for the absorption band and the blue colour. We suggest that at least it plays a dominant role in the stabilization of the blue colour.

  14. Spatial and Temporal Variations of Hazes in Guangxi from 1960 to 2009%1960-2009年广西霾日时空变化特征

    Institute of Scientific and Technical Information of China (English)

    廖国莲; 曾鹏; 郑凤琴; 韦玉洁

    2011-01-01

    利用1960-2009年广西80个地面观测站资料,运用EOF、线性倾向估计等统计方法,分析了近50年广西霾日数的时空变化特征.结果表明:近50年广西霾日数总体呈上升趋势,与该地区人类活动和经济发展引起的污染排放增长密切相关;空间分布呈现出主要城市及其周边地区霾日多,边远地区及沿海地区霾日少的特点;广西霾天气主要发生在秋、冬季,以轻微霾(能见度为5~10 km)为主,且霾天气发生时的相对湿度8成以上介于70%~90%;除了空气污染之外,近50年风速呈下降趋势可能也导致更多的霾天气.%With the development of Guangxi economy and accelerating urbanization, human activities have discharged various pollutants into the atmosphere, which cause increasing atmospheric haze phenomenon in recent years. The toxic and harmful substances of hazes affect human health and environment a lot, becoming a new kind of severe weather. So it is very important to analyze the spatial-temporal variation characteristics of haze, which provide scientific bases for effective forecasting and controlling haze weather. Based on the data provided by 80 surface observation stations from 1960 to 2009, the haze days in Guangxi are calculated, and the characteristics of spatial-temporal variations of haze in Guangxi and its relationship with climate elements are analyzed by using EOF, linear trend estimation and other analytical methods. The average annual haze days in Guangxi are found to rise gradually over the past 50 years, which is closely related to the human activity and the increase in emissions by economic development. The haze happens more frequently in major cities and their surrounding areas than in remote areas and coastal areas. Comparing the periods of 1960-1979 and 1980-2009, and the remote areas and coastal areas, the haze days increase by different degrees in most parts of Guangxi, especially in Wuzhou, Liuzhou and other industrial

  15. Implications of the regional haze rule on renewable and wind energy development on native American lands in the west

    International Nuclear Information System (INIS)

    A study conducted at Northern Arizona University investigated the barriers and opportunities facing Native American tribes in the West when considering development of their renewable energy resources in order to reduce regional haze. This article summarizes some of the findings of that work with special attention to wind energy. Background information is presented concerning the Regional Haze Rule and the Western Regional Air Partnership, and some of the circumstances surrounding development of tribal energy resources. An assessment of tribal energy issues revealed that many Native American tribes are interested in developing their renewable resources. However, this development should occur within the context of maintaining and strengthening their cultural, social, economic and political integrity. Furthermore, it is shown that Native American lands possess an abundant wind resource. A list of potential actions in which tribes may participate prior to or during development of their wind or renewable resources is provided. (author)

  16. A study of photopolarimeter system UV absorption data on Jupiter, Saturn, Uranus, and Neptune - Implications for auroral haze formation

    International Nuclear Information System (INIS)

    The present investigation of the dark hazes of Jupiter, Saturn, Uranus, and Neptune on the basis of Voyager 2 UV data notes a geographic correlation between the auroral zones of Jupiter and Saturn and UV-dark polar regions. While the auroral fluxes and penetration depths on Jupiter and Saturn may suffice for a darkening of the polar regions by auroras' action on methane, Uranus and Neptune are found to be bright at all latitudes. In the former case, this brightness is in keeping with auroral electron energies too small to reach the CH4 homopause at which haze production occurs; in the latter case, a UV-dark band exists from 30 deg S to 5 deg N which is probably unrelated to auroral processes. 63 refs

  17. HaChi - Size- and time-resolved measurements of submicron winter and summer haze particles from the Beijing area

    Science.gov (United States)

    Nekat, B.; van Pinxteren, D.; Iinuma, Y.; Gnauk, T.; Müller, K.; Herrmann, H.

    2010-12-01

    Satellite observations of the Beijing clearly show that this area is frequently plagued with heavy air pollution caused by significantly increased particle emissions. The aerosol affects the regional air quality and impairs the visibility by the formation of haze. This process strongly depends on the chemical, optical, and microphysical properties of particles governing the ability to take up water. Furthermore, these particles play an important role for cloud formation processes, precipitation, and the radiative balance of the atmosphere by subsequently acting as Cloud Condensation Nuclei. The HaChi project (Haze in China) targets to study chemical parameters of submicron aerosol in order to associate the chemical composition with the ability to act as condensation nuclei during the formation of haze. For this purpose, two measurement campaigns were performed at a background site located between Beijing and Tianjin on different meteorological conditions, respectively. The winter campaign was carried out in March 2009 and the summer campaign took place from mid July 2009 to mid August 2009. PM1 samples were continuously sampled every 24 hours using a DIGITEL high volume sampler and size- and time-resolved aerosol samples were collected using a 10-stage Berner impactor in a 6 hours day/night regime. This study presents the results of the chemical characterization of submicron particles from winter haze and summer haze measurements in comparison to clear and dusty day measurements. All samples were analyzed for the mass concentration, inorganic ions and carbon sum parameters such as elemental (EC), organic (OC) and water soluble organic carbon (WSOC). The WSOC fraction of filter samples was analyzed for polar substances such as dicarboxylic acids and saccharides. Fatty acids were determined to investigate surface-active substances and metals from the impactor measurements for crust material. Usually, highest PM1 concentrations are observed during haze periods, while

  18. GPAW on Blue Gene/P

    Science.gov (United States)

    Romero, Nichols; Enkovaara, Jussi; Dulak, Marcin; Glinsvad, Christian; Larsen, Ask; Mortensen, Jens; Shende, Sameer; Morozov, Vitali; Greeley, Jeffrey

    2011-03-01

    Density function theory (DFT) is the most widely employed electronic structure method due to its favorable scaling with system size and accuracy for a broad range of molecular and condensed-phase systems. The advent of massively parallel supercomputers have enhanced the scientific community's ability to study larger system sizes. Ground state DFT calculations of systems with O (103) valence electrons can be routinely performed on present-day supercomputers. The performance of these massively parallel DFT codes at the scale of 1 - 10K execution threads are not well understood; even experienced DFT users are unaware of Amdahl's Law and the non-trivial scaling bottlenecks that are present in standard O (N3) DFT algorithms. The GPAW code was ported an optimized for the Blue Gene/P. We present our algorithmic parallelization strategy and interpret the results for a number of benchmark tests cases. Lastly, I will describe opportunities for computer allocations at the Argonne Leadership Computing Facility. This work has been supported by the Academy of Finland (Project 110013), Tekes MASI-program, Danish Center for Scientific Computing, Lundbeck Foundation, Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357.

  19. Blue Skies, Coffee Creamer, and Rayleigh Scattering

    Science.gov (United States)

    Liebl, Michael

    2010-01-01

    The first physical explanation of Earths blue sky was fashioned in 1871 by Lord Rayleigh. Many discussions of Rayleigh scattering and approaches to studying it both in and out of the classroom are available. Rayleigh scattering accounts for the blue color of the sky and the orange/red color of the Sun near sunset and sunrise, and a number of…

  20. Blue collection bag after ileal diversion.

    Science.gov (United States)

    Hildreth, T A; Cass, A S

    1978-02-01

    Five children with ileal diversions have shown asymptomatic blue staining of the urine collection bags. A tryptophan derivative (indican) in the urine that oxidizes to indigo blue on exposure to air is thought to be the cause of this benign transient phenomenon. PMID:628994