Top PDF Scavenging of ultrafine particles by rainfall at a boreal site: observations and model estimations

Scavenging of ultrafine particles by rainfall at a boreal site: observations and model estimations

Scavenging of ultrafine particles by rainfall at a boreal site: observations and model estimations

cipitation recorded during 15 min is mostly less than 1 mm, while the highest values reach ∼5 mm during the warmest months of the summer when convective precipitation is more frequent. However, such convective precipitation events are not too intense overall, since they generally produced R≤10 mm h −1 . Rain duration (Fig. 5b) shows that the most frequent duration is less than 30 min, and there are very few cases with

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Modeling ultrafine particle growth at a pine forest site influenced by anthropogenic pollution during BEACHON-RoMBAS 2011

Modeling ultrafine particle growth at a pine forest site influenced by anthropogenic pollution during BEACHON-RoMBAS 2011

The time series of measured and simulated CCN (0.5 % SS) number concentrations are shown in Fig. 10c–d. In this study, CCN concentrations are calculated at 0.5 % SS in the WRF-Chem model. As CCN measurements were mainly performed at high supersaturation (Sect. 3.1), here we compare model results with CCN observations at 0.5 % SS. As previously mentioned (Sec. 4.1), only particles with diameters larger than 60 nm are likely to activate at 0.5 % SS. The Nucleation-bsoa run reasonably simulates the CCN (0.5 % SS) concentrations in both time series (Fig. 10c, d) and diurnal profiles (Fig. 6i, j) except on 29 July as expected. Figure 6i shows that the Nucleation-bsoa run captures the magnitudes of CCN (0.5 % SS) during the daytime, with however a slight underestimation of the afternoon values dur- ing PBE days. The Nucleation-bsoa simulation reproduces more accurately CCN (0.5 % SS) concentrations than the Ref-8bins run, especially during PBE days. This difference suggests that sub-40 nm particles and their growth to larger sizes (> 60 nm) that can activate at 0.5 % SS significantly contribute to CCN. The Nucleation-off simulation underes- timates by a factor of 3 the CCN (0.5 % SS) number concen- tration compared to Nucleation-bsoa (Fig. 10). This indicates that the ability of the modified WRF-Chem to predict PBEs is dependent on including both AN nucleation parameterization and secondary organic aerosol (SOA) formation. Comparing the results of Nucleation-bsoa with Nucleation-off during the two simulating periods, we find that the nucleation explains 67 % of near-surface CCN (0.5 % SS) concentrations at the MEFO site. This is an extreme case; however, it illustrates that the accurate treatment of nucleation in 3-D models is important for predicting CCN (0.5 % SS) concentrations and aerosol number concentration in general.
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Quantification of the volatility of secondary organic compounds in ultrafine particles during nucleation events

Quantification of the volatility of secondary organic compounds in ultrafine particles during nucleation events

In order to isolate the effect of organic volatility on the growth of ultrafine particles during the 9 event days, we con- strain the box model inputs with measurements. The initial size distribution for each simulation is taken from observa- tions at each site just prior to the nucleation event. Figure 1 shows the measured nucleation rate, the sulfuric acid con- centration and the SOA formation rate used for inputs to the TOMAS box model for all the Hyyti¨al¨a 10 April 2007 sim- ulations. The model-input nucleation rates as a function of time are derived from the SMPS data using the method of Dal Maso et al. (2005). The nucleated particles are added to the model at 3 nm, the lower limit of the DMPS/SMPS detection. For simulations of the Hyyti¨al¨a events, gas-phase sulfuric acid concentrations are specified in the model based on the CIMS measurements. For the simulations of the Eg- bert events, sulfuric acid is added to the gas phase based on the mass change in sulfate concentrations measured by the AMS (the sulfuric acid then condenses onto the parti- cles in TOMAS such that the sulfate masses in the model will match AMS observations). Since nucleation rates are derived from the SMPS data, sulfuric acid vapor concentra- tions are not used to predict nucleation rates. Organic mate- rial is initially formed in the gas phase (particle-phase chem- istry discussed later) using the change in aerosol organic mass concentrations measured by the AMS with time. Since all SOA formed has a volatility of 10 −1 µg m −3 or less and total organic concentrations are generally much larger than
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The effect of coal-fired power-plant SO<sub>2</sub> and NO<sub>x</sub> control technologies on aerosol nucleation in the source plumes

The effect of coal-fired power-plant SO<sub>2</sub> and NO<sub>x</sub> control technologies on aerosol nucleation in the source plumes

ticles by power plants without particulate controls could also provide a large amount of surface area and would also greatly reduce new-particle formation and growth. These primary ash particles may be important in developing countries where particulate con- trols are not implemented or for historical simulations of periods prior to when these controls were commonplace in developed countries (e.g. the United States before the

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Morphology and Mixing State of Aged Soot Particles at a Remote Marine Free Troposphere Site : Implications for Optical Properties

Morphology and Mixing State of Aged Soot Particles at a Remote Marine Free Troposphere Site : Implications for Optical Properties

The radiative properties of soot particles depend on their morphology and mixing state, but.. 27 .[r]

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Evaluation of physicochemical and antioxidant properties of peanut protein hydrolysate.

Evaluation of physicochemical and antioxidant properties of peanut protein hydrolysate.

Peanut is the world’s fourth most important source of edible vegetable oil and the third most important source of vegetable protein feed meal [1]. In China, peanuts have been grown as an oil seed crop for export and for production of the edible oil, while the protein residue in the form of oil cake is used as animal feed [2,3]. Recently peanut protein has been receiving increasing attention from the food industry, as an additive in meat and dairy products, baked food, health food and other similar commercially important items. One of the notable features of peanut protein is its high nutritional value; but its functional properties, digestibility and bioactivity are relatively low [4]. However, its hydrolysate which is peanut peptide could have better physicochemical properties such as the solubility, emulsifying capacity, foam capacity, etc. Certain peptide sequences that are correlated with potent antioxidative and radical scavenging functions have been identified by sequence comparison of various proteins and are present in peanut protein [5].
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Aerosol nucleation and its role for clouds and Earth's radiative forcing in the aerosol-climate model ECHAM5-HAM

Aerosol nucleation and its role for clouds and Earth's radiative forcing in the aerosol-climate model ECHAM5-HAM

(defined as particles with dry diameter >3 nm) from the years 1990 to 1999 over the Pacific Ocean. These aerosol profiles are shaped by aerosol nucleation in convective outflow (Clarke and Kapustin, 2002) and cover large areas with a comparably homoge- neous meteorology, hence constitute ideal reference values for evaluating the aerosol nucleation schemes in ECHAM5-HAM. This data set has the additional advantage that

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The link between atmospheric radicals and newly formed particles at a spruce forest site in Germany

The link between atmospheric radicals and newly formed particles at a spruce forest site in Germany

ducing a variety of different macromolecules that have been seen in infrared spectra (Wolf et al., 2009). Organic peroxy radicals with less than six carbon atoms seem to split after formation of a very short-lived intermediate caused by the release of reaction energy, undergoing transfer to stable carbonyl compounds. Thus, they cannot con- tribute to particle mass and may seal the reactive sites preventing further reactions.

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Fields of study and the earnings gap by race in Brazil

Fields of study and the earnings gap by race in Brazil

The aim of this paper is to investigate the labor earnings differential between white and black workers with a bachelor ’s or graduate degree in Brazil, decomposing this gap into components accounted for by observable differences across individuals, and differences in the return on these characteristics. The empirical analysis uses data from the 2000 and 2010 Brazilian Census. This survey, conducted by the Brazilian Census Bureau (IBGE), has information about labor market and field of study for those who have tertiary education, in addition to demographic characteristics of the individuals. The empirical strategy is based on decompositions of the mean labor earnings difference between white and black workers using the traditional Oaxaca- Blinder methodology (Oaxaca, 1973 and Blinder, 1973), and decompositions for different quantiles of the earnings distribution, through the method proposed by Fortin, Lemieux and Firpo (2009). This way, not only the racial earnings gap could be attributed to differences in the distribution of observable characteristics, and in the returns on these characteristics, but also the former component can be decomposed into contributions associated with individual’s distribution across fields of study, mismatch between education and occupation, attainment of a graduate degree and demographic variables. And this could be done for different percentiles of the earnings distribution.
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Evaluating the influence of selected parameters on sensitivity of a numerical model of solidification

Evaluating the influence of selected parameters on sensitivity of a numerical model of solidification

Sensitivity analysis was conducted each time for the model described in Section 3, for which it was assumed that the parameters vary in ranges given in Table 1. Table 2 lists parameters influence of which was not taken into consideration in sensitivity analysis. According to the fact that these parameters are connected with the phase change diagram, they cannot be changed freely and independently from one another. Additionally, in Table 2 physical parameters of the mould are included. Table 2.

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Microphysical processing of aerosol particles in orographic clouds

Microphysical processing of aerosol particles in orographic clouds

During their residence time in the atmosphere, aerosol par- ticles undergo various modifications which may affect their ability to serve as CCN and IN. Thereby, aerosol processing within clouds plays a crucial role, as the aerosol mass, com- position and mixing state can be altered. Due to activation, nucleation and collision–coalescence processes aerosol par- ticles are incorporated into hydrometeors. Processes like au- toconversion, accretion, aggregation, freezing, melting, rim- ing and self-collection transfer aerosol mass and number between the different hydrometeor classes. Aqueous-phase chemistry within droplets can lead to the formation of new aerosol mass. Finally, wet deposition, sedimentation and scavenging processes lead to a removal of aerosol mass from the atmosphere. However, a substantial fraction of hydrom- eteors evaporate/sublimate, releasing newly formed aerosol particles to the atmosphere with different size, composi- tion and mixing state compared to the original ones. Re- cent investigations concerning the impact of aerosol solubil- ity and recycled aerosol particles on orographic cloud forma- tion have been conducted by Xue et al. (2010, 2012). They explicitly account for the release of aerosol particles upon droplet and rain evaporation, replenishing between one-third and two-thirds of the scavenged aerosol particles. In their model configuration, the CCN number concentration explic- itly depends on the number concentration and properties of the background and regenerated aerosol particles. In ideal- ized 2-D simulations of warm-phase clouds over two bell- shaped mountains, recycled aerosol particles enhance the cloud droplet number concentration and thus reduce precipi- tation formation at the second mountain (Xue et al., 2010). In mixed-phase clouds, regenerated aerosol particles were found to inhibit the riming process by changing the droplet size distribution (Xue et al., 2012).
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Bank Privatization and Market Structure of the Banking Industry: Evidence from a Dynamic Structural Model

Bank Privatization and Market Structure of the Banking Industry: Evidence from a Dynamic Structural Model

a Dynamic Structural Model”. We are indebted to Martin Pesendorfer for his support and guidance during this project. We would like to thank Dimitri Szerman for the help with the data and for insightful comments on several versions of this draft. Robinson Silva helped us to organize the data. We also benefited from discussions with Bernardo Guimarães, Bruno Rocha, Emmanuel Guerre, Fabio Pinna, Francesco Caselli, Francisco Costa, Gabriel Garber, Jason Garred, Joachim Groeger, Johannes Spinnewijn, Maitreesh Ghatak, Matthew Gentry, Michael Dickstein, Panle Jia, Pasquale Schiraldi, Pedro Carvalho, Robert Miller and Tim Besley. Fabio gratefully acknowledges the financial support from CAPES (Brazilian Ministry of Education) and Daniel gratefully acknowledges the support from CNPQ (Brazilian Ministry of Science and Technology). The usual disclaimer applies.
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Nanoparticles in boreal forest and coastal environment: a comparison of observations and implications of the nucleation mechanism

Nanoparticles in boreal forest and coastal environment: a comparison of observations and implications of the nucleation mechanism

air masses have passed over land area, VOCs emitted from the vegetation or anthro- pogenic emissions might explain the higher and more varying concentrations. At least the nano-CN seem not to consist of the same biogenic iodine compounds that make the nucleation mode particles, as they do not exhibit similar tidal cycle than the parti- cle formation events. The exact chemical composition of the nano-CN remains to be

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The mass and number size distributions of black carbon aerosol over Europe

The mass and number size distributions of black carbon aerosol over Europe

The definitions of EC and BC have been discussed in de- tail in the literature (see e.g. Bond and Bergstrom, 2006; An- dreae and Gelencs´er, 2006), but in general their definitions are based on the measurement technique (thermo-optical or optical respectively) used to detect the particles. The dif- ferences between measurements of EC and BC in different environments have been quantified in several instrument in- tercomparison studies (e.g. ten Brink et al., 2004; Jeong et al., 2004; Hitzenberger et al., 2006; Bae et al., 2007; Ram et al., 2010). In general there is a high correlation between the measured mass concentrations of EC and BC (e.g. ten Brink et al., 2004; Jeong et al., 2004; Bae et al., 2007), but the differences in the absolute mass concentrations are highly variable. For example, Ram et al. (2010) found the BC mass concentration to be ∼20 % higher than that of EC, whereas ten Brink et al. (2004) and Jeong et al. (2004) found a dif- ference of up to a factor of 3 between measured BC and EC mass concentrations. It is important to note that, in the latter two measurement studies, large differences were also found between BC values obtained with the various optical meth- ods, and ten Brink et al. (2004) found EC concentrations dif- fered by up to a factor of ∼4 between methods. The type of modelled carbonaceous aerosol will therefore depend on the measurements used to compile the model emission inventory. In GLOMAP, emissions of carbonaceous combustion aerosol are based on AeroCom-prescribed emission data sets for the year 2000 (Dentener et al., 2006). The AeroCom in- ventory includes emissions of primary carbonaceous aerosol from anthropogenic (fossil fuel and biofuel) sources based on Bond et al. (2004) and from biomass burning following van der Werf et al. (2003). The emission inventory developed by Bond et al. (2004) is reported by Vignati et al. (2010) to be predominantly based on measurements of the refractive be- haviour of carbon (thermo-optical measurements) and thus is more representative of EC. However, since systematic un- certainties associated with the measurements are generally larger than the operational differences in the measurement techniques, Bond et al. (2004) treat measurements of EC as equal to BC, referring to the quantity as “BC”. In addition, Koch et al. (2009) refer to both the modelled and measured quantities as “BC” in their evaluation of AeroCom models
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The origin of summer monsoon rainfall at New Delhi by deuterium excess

The origin of summer monsoon rainfall at New Delhi by deuterium excess

from GNIP (Global Network for Isotopes in Precipitation), accessible at: http://isohis.iaea.org; the re-analysis data of NCEP/NCAR zonal wind speed and relative humidity are available at http://www.cdc.noaa.gov/cdc/reanalysis/ reanalysis.shtml; and the summer monsoon rainfall of the northwestern India refers to Sontakke and Nityanand Singh (1996).

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Bioremoval Capacity Of Phenol By Green Micro-Algal And Fungal Species Isolated From Dry Environment

Bioremoval Capacity Of Phenol By Green Micro-Algal And Fungal Species Isolated From Dry Environment

phenol and utilize it as sole carbon and energy source. Another reason for this trend may be attributed to sporulation stage which requires a period of time to enter mycelium stage. After the first three days, phenol removal by fungi was significantly increased until day 18. Then, bioremoval efficiency was slightly different. The detected increased removal capacity can be explained by the abundance of a carbon source which improves the fungi performances and growth and afterwards the depletion of carbon source in the solution which is reflected as decrease or an inhibition in the bioremoval process (mortality of the cells). Because there was no significant differences between the two species of algae, one species of algae (Desmodesmus sp.) was selected in the experiments, and one species of fungi (Rhizopus sp.) was selected to be used in the experiments for the same reason. Bioremoval processes may be carried out by pure culture or by a consortium of microbes [19]. When phenol bioremoval efficiency of the consortium (Desmodesmus sp., and Rhizopus sp.) is compared to axenic cultures of Desmodesmus sp., or Rhizopus sp. at 25 mg/L of phenol concentration, it can be concluded that more than 94% phenol bioremoval was achieved in the presence of the consortium. It seem that there is a both species (Desmodesmus sp. and Rhizopus sp.) tolerate phenol as a consortium better than do individual species [20]. Remarkably, at higher phenol concentration, it was found the phenol bioremoval by the consortium (Desmodesmus sp., and Rhizopus sp.) is lower than axenic cultures of either Desmodesmus sp. or Rhizopus sp. Lower phenol bioremoval at higher concentration of phenol by the consortium as compared to axenic cultures may be may be explained by the use
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Usefulness of different techniques for measuring body composition changes during weight loss in overweight and obese women

Usefulness of different techniques for measuring body composition changes during weight loss in overweight and obese women

management program through newspaper ads, the internet, and announcement flyers. Inclusion criteria were age greater than 24 years, premenopausal and not currently pregnant, BMI greater than 24.9 kg/m 2 , healthy, and not currently taking medications. After one orientation session, 152 women signed up for the program. During the run-in phase, four women decided not to participate (reporting new time and scheduling conflicts), four did not comply with testing requirements and were excluded, three women found out they were pregnant or decided to attempt pregnancy and were also excluded, and one subject was found ineligible due to medical reasons (untreated hyperthyroidism), leaving a total of 140 women who started the intervention. An initial visit with the study physician ensured that subjects met all medical inclusion criteria. Participants agreed to refrain from participating in any other weight loss program and gave written informed consent prior to participation in the study. The Institutional Review Board of the Faculty of Human Movement, Technical University of Lisbon, approved the study, described elsewhere (10).
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A Method To Find The Area Of Sector Without The Usage Of Angle Made By The Chord

A Method To Find The Area Of Sector Without The Usage Of Angle Made By The Chord

As we know that to find the area of sector the angle made by the chord (that is chord which divides the circle) is required. But in the below method we find the ratio of the segments of the circle. Thus by relating the area of segment to the area of sector the area of sector could be found. The ratio of area of segments is related to tangents that are drawn through diameter on either side.

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Evaluating the effect of partial contributing storage on storage–discharge function from recession analysis

Evaluating the effect of partial contributing storage on storage–discharge function from recession analysis

of water balance dynamics is a challenge partly due to the fact that evaporation and water storage data are limited in many watersheds. Evaporation is controlled by com- plex factors such as atmospheric condition, vegetation, and water availability. With the advancement of measurement technology, evaporation can be estimated by utilizing remote sensed data which covers large spatial scales with high resolution (Mu et al.,

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Tyrosinase inhibitory effects and antioxidative activities of saponins from Xanthoceras Sorbifolia nutshell.

Tyrosinase inhibitory effects and antioxidative activities of saponins from Xanthoceras Sorbifolia nutshell.

Antioxidants are defined as substances that can delay or prevent oxidative cellular oxidisable substrates. They work via two ways: scavenging reactive oxygen species (ROS) or inhibiting the generation of ROS. At present, synthetic antioxidants are widely used for Whitening cosmetics and industrial processing to preserve food quality. However, some reports have been suspected of the side effects and stability of some common ones. For example, hydroquinone has been associated with mutagenicity and the incidence of ochronosis in African countries [7]. Thus, there has been increasing interest in exploring natural, safe and effective alternative sources, since they can protect the human body from free radicals and retard the progress of many chronic diseases [8].
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