A Medley of National Favourites. Things That Make Slovenes ShineSalted with the words of Benedict Anderson: to the Slovene nation, a love of Carniolan sausages, the Vače Situla, accordions and ...gibanica cakes “have an aura of fatality”,Peppered with Raymond Williams: that Carniolan sausages, the Vače Situla, accordions and gibanica reproduce a “structure of national feeling”, andServed with Karl Marx: these grandes dames of the Slovene nation weighas they must on the brains of living Slovenes.
Prostor hrvatskog Podunavlja zbog svoga strateškog položaja, uz najvažniju europsku prirodnu prometnicu, oduvijek je bio predmetom zanimanja brojnih populacija još od prapovijesnih vremena. Dunav ...nije samo spajao različite svjetove, nego ih je i razdvajao. Bogata arheološka građa iz doba prvih stoljeća posljednjeg tisućljeća prije Krista, koja je zabilježena na nalazištima na području Baranje, istočne Slavonije i zapadnog Srijema, svjedoči o važnosti ovog prostora u definiranju prijelaza kasnoga brončanog na starije željezno doba za širi južnopanonski prostor. Tijekom mlađe faze kasnoga brončanog doba i na početku starijega željeznog doba na prostoru hrvatskog Podunavlja rasprostirala se daljska grupa s jakim uplivima bosutske grupe, što se najjasnije prepoznaje u karakterističnim keramičkim oblicima ukrašenim urezivanjem te u Basarabi stilu koji svjedoče o intenzivnim kontaktima između dvije susjedne kulturne pojave što su dijelile i mnoge druge zajedničke značajke materijalne ostavštine, prije svega metalne predmete konjske opreme i nošnje. Intenzivna komunikacija između nositelja daljske i bosutske grupe, iako su pripadali različitim svjetovima i tradicijama, obilježila je početke željeznog doba koje se prema novim znanstvenim spoznajama datira prije od dosad ustaljenih datuma.
Inside orchards, turbulent coherent structures dominate the transport of heat, momentum, and moisture between the canopy and the atmosphere. Integrated quadrant analysis is a method to visualize the ...trajectory of individual turbulent coherent structures using in situ data from three-dimensional anemometry. In this paper, integrated quadrant analysis is used to characterize the turbulent transport of heat and momentum from two orchard experiments: one in the interrow space (the Canopy Horizontal Array Turbulence Study from Dixon, California in May and June 2007) and one in the crown of a tree (the Vertical Array Cherry Experiment from Linden, California in November 2019). By using the integrated quadrant analysis (IQA) method, this paper demonstrates the importance of the cross-wind velocity component in maintaining the turbulent coherent structures. Results from integrated quadrant analysis in three dimensions support the idea that the microfront is collocated with the boundary of a sweep and an ejection in a convective boundary layer. Moreover, in both orchards, there are preferred planar trajectories for individual coherent structures that do not depend on wind regimes. The statistical profile of the turbulence quantities, as well as individual coherent structures, are not appreciably different in the interrow space or within the crown.
•IQA provides the 3D coherent structure trajectory in two orchard experiments.•Individual coherent structures show characteristic planar trajectories.•Turbulent coherent structures have peak intensity near the top of the canopy.•The cross-stream velocity is large during the passage of coherent structures.
A text localisation and tracking method is presented that finds text-regions in videos and assigns unique IDs to their trajectories. For the goal, a graph-based framework that can work with existing ...text detection methods is developed. To be precise, graphs are built where vertices are image-level text detection results and edges represent the correspondence scores of the vertices. From these graphs, text-region trajectories by using the graph-cut algorithm are extracted. This approach allows considering false positives and misses, as well as their patch-based tracking results at the same time, and text trajectories are reliably extracted. Finally, the results are refined by interpolating misses and filtering out false positives. The proposed method is submitted to the International Conference on Document Analysis and Recognition 2015 robust reading competition (video text localisation) and the method showed the best performance in terms of CLEAR MOT metrics and was ranked third place according to VACE metrics among the seven participating methods.
In this study, we investigated the performance of an electrostatic precipitator (ESP) operating at high flow rates (i.e., 50–100 lpm) as a fine particulate matter (PM2.5) collector for toxicological ...studies. The ESP optimum configuration (i.e., flow rate of 75 lpm and applied voltage of +12 kV) was determined based on maximum particle collection efficiencies and minimum ozone emissions associated with the instrument using different laboratory-generated aerosols. This configuration resulted in particle collection efficiencies above 80% for almost all particles in the size range of 0.015–2.5 μm while the ozone concentration was 17 ppb. The ESP was then deployed to our sampling site in central Los Angeles to evaluate its performance using ambient particles under the optimum configuration. Chemical composition and oxidative potential of PM2.5 samples collected on the foils placed inside the ESP tube were compared with those collected concurrently on filters and aerosol slurries using the versatile aerosol concentration enrichment system (VACES) operating in parallel. Our results demonstrated that the ESP was more efficient in preserving labile inorganic ions and total organic carbon (TOC) compared to filters. PM samples collected on ESP substrates also showed higher intrinsic oxidative potential compared to the filters, which might be the result of better preservation of redox active semi-volatile organic compounds on the ESP substrates. However, the TOC concentrations and intrinsic oxidative potential of PM samples collected on ESP substrates were somewhat lower than the aerosol slurries collected by the VACES, probably due to deficiency of water-insoluble compounds in extracted PM samples from ESP substrates. In conclusion, while particle collection for toxicological purposes by the ESP is somewhat inferior to a direct aerosol-into-liquid collection, the ESP performs equally well, if not better, than conventional filter samplers and can be utilized as a simple and adequately efficient PM collector for toxicological studies.
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•Application of a high-volume ESP for toxicological studies was investigated.•Optimum flow and voltage of the ESP was determined in the laboratory.•ESP can capture semi-volatile species more efficiently than filter sampler.•Oxidative potential of PM samples collected by ESP was higher than filter.•Unlike BioSampler, ESP and filter extracts cannot preserve water-insoluble species.
In this study, we developed a novel method for generating aerosols that are representative of real-world ambient particulate matter (PM) in terms of both physical and chemical characteristics, with ...the ultimate objective of using them for inhalation exposure studies. The protocol included collection of ambient PM on filters using a high-volume sampler, which were then extracted with ultrapure Milli-Q water using vortexing and sonication. As an alternative approach for collection, ambient particles were directly captured into aqueous slurry samples using the versatile aerosol concentration enrichment system (VACES)/aerosol-into-liquid collector tandem technology. The aqueous samples from both collection protocols were then re-aerosolized using commercially available nebulizers. The physical characteristics (i.e., particle size distribution) of the generated aerosols were examined by the means of a scanning mobility particle sizer (SMPS) connected to a condensation particle counter (CPC) at different compressed air pressures of the nebulizer, and dilution air flow rates. In addition, the collected PM samples (both ambient and re-aerosolized) were chemically analyzed for water-soluble organic carbon (WSOC), elemental and organic carbon (EC/OC), inorganic ions, polycyclic aromatic hydrocarbons (PAHs), and metals and trace elements. Using the aqueous filter extracts, we were able to effectively recover the water-soluble components of ambient PM (e.g., water-soluble organic matter, and water-soluble inorganic ions); however, this method was deficient in recovering some of the important insoluble components such as EC, PAHs, and many of the redox-active trace elements and metals. In contrast, using the VACES/aerosol-into-liquid collector tandem technology for collecting ambient PM directly into water slurry, we were able to preserve the water-soluble and water-insoluble components very effectively. These results illustrate the superiority of the VACES/aerosol-into liquid collector tandem technology to be used in conjunction with the re-aerosolization setup to create aerosols that fully represent ambient PM, making it an attractive choice for application in inhalation exposure studies.
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•We developed a novel method for generating physically and chemically stable sources of PM in inhalation exposure studies.•Using the aqueous filter extracts, the water-soluble fractions of ambient PM were perfectly recovered.•Re-aerosolization of aqueous suspensions of PM was deficient in reconstructing water insoluble PM components.•Results indicated the advantages of VACES/aerosol-into-liquid collector tandem technology to recover all components of PM.
In this study, we investigated the organic constituents and toxicological characteristics of PM2.5 liquid suspensions collected by the means of a modified versatile aerosol concentration enrichment ...system (VACES)/aerosol-into-liquid collector tandem technology. Filter and slurry PM2.5 samples were collected during warm (spanning from mid-August 2019 to early-September 2019) and cold (from mid-December 2019 to early-January 2020) seasons at an urban site in central Los Angeles. The collected samples were chemically analyzed for their total organic carbon (TOC) as well as individual organic species, including polycyclic aromatic hydrocarbons (PAHs), hopanes and steranes, n-alkanes, and organic acids. In addition, the oxidative potential of PM2.5 samples was quantified by means of the 2′,7′-dichlorodihydrofluorescein (DCFH) in vitro assay. Overall, our findings revealed a very good agreement between the mass fractions of organic compounds in the collected PM2.5 slurries and filters, judging by the average slurry-to -filter ratios of 1.17 ± 0.15, 1.13 ± 0.14, 1.13 ± 0.15, and 1.16 ± 0.22 for PAHs, hopanes and steranes, n-alkanes, and organic acids, respectively. Moreover, comparable (Pvalue = 0.2) oxidative potential levels were observed between the collected filters and PM2.5 liquid suspensions. The aqueous PM suspensions collected by the VACES/aerosol-into-liquid collector exhibited slightly higher (although not statistically significant) capture of some semi-volatile organic compounds (SVOCs), probably due to less sampling artifacts and better preservation of these SVOCs collected directly into aqueous suspensions compared to the filter samplers. The outcomes of this study confirm the efficient collection of PM-bound organic species in aqueous slurries by the aerosol-into-liquid collector, further corroborating the ability of this sampler to be used as an attractive alternative to filter samplers for collection of PM2.5 for toxicological studies.
•PM2.5 liquid suspensions and filters were analyzed for their organic constituents in central Los Angeles.•TOC, PAHs, hopanes and steranes, n-alkanes, and organic acids fractions were comparable between filter and slurry samples.•Slightly higher contribution of organics to slurries were due to the sampling artifacts for slurry/filter collection.•Results underscored the efficiency of VACES/aerosol-into-liquid collector for PM2.5 slurry collection.
This study describes an investigation of the relative contributions of water-soluble and water-insoluble portions of ambient particulate matter (PM) to cellular redox activity. Size-fractionated ...ambient PM samples (coarse, PM2.5 and ultrafine PM) were collected in August–September of 2012 at an urban site in Los Angeles, using the Versatile Aerosol Concentration Enrichment System (VACES)/BioSampler tandem system. In this system, size-fractionated ambient PM was concentrated and collected directly into an aqueous suspension, thereby eliminating the need for solvent extraction required for PM collected on filter substrates. Separation of water-soluble and water-insoluble fractions of PM was achieved by 10 kilo-Delton ultra-filtration of the collected suspension slurries. Chemical analysis, including organic carbon, metals and trace elements, and inorganic ions, as well as measurement of macrophage reactive oxygen species (ROS) activity were performed on the slurries. Correlation between ROS activity and different chemical components of PM was evaluated to identify the main drivers of PM toxicity. Results from this study illustrate that both water-soluble and water-insoluble portions of PM play important roles in influencing potential cellular toxicity. While the water-soluble species contribute the large majority of the ROS activity per volume of sampled air, the highest intrinsic ROS activity (i.e. expressed per PM mass) is observed for the water-insoluble portions. Organic compounds in both water-soluble and water-insoluble portions of ambient PM, as well as transition metals, several with recognized redox activity (Mn, V, Cu and Zn), are highly correlated with ROS activity. These results may underscore the potential of these chemicals in driving the toxicity of ambient PM. Results from this study also suggest that collection of particles directly into a liquid suspension for toxicological analysis may be superior to conventional filtration by eliminating the need for extraction and by potentially reducing the losses of semi-volatile and redox active species such as organic compounds.
•A novel PM sampling methodology comparing to conventional filter collection was introduced.•Separation of water-soluble and water-insoluble portions of PM samples was achieved.•Comparison of ROS activity between water-soluble and water-insoluble portions of PM was shown.•Significant correlations were observed between ROS activity and OC, Mn, V, Cu and Zn.
Particulate nitrite is a critical source of hydroxyl radicals; however, it lacks high-resolution methods due to its low abundance and stability to explore its formation mechanism. In this study, a ...modified versatile aerosol concentration enrichment system (VACES) coupled with ion chromatography (IC) was used to measure particulate NO2 – hourly online and achieve a lowered detection limit of 10–3 μg m–3. VACES-IC was used to observe a high- and low-concentration events of PM1.0-NO2 – in Shanghai, corresponding to the ambient-level concentrations of 0.34 and 0.05 μg m–3, respectively. The morning peak concentrations of NO2 – even exceeded 3σ (standard deviation) in the high-concentration event due to the reduction of NO2 by aerosol SO3 2– based on kinetics and regression analysis. This implies that controlling SO2 emissions would be an effective strategy to decrease morning NO2 – concentrations, correspondingly reducing the kinetic formation of SO4 2– by 20.8–34.8%. However, after sunrise, NO2 – formation was primarily attributed to NO2 hydrolysis at pH 4.97–6.14. In the low-concentration event, NO2 hydrolysis also accounted for an overwhelming proportion (∼90%) of NO2 – formation. This work estimates the contribution of different paths to particulate NO2 – formation based on newly established high-resolution measurements.
Reduced nitrogen-containing organic compounds (NOCs) in aerosols play a crucial role in altering their light-absorption properties, thereby impacting regional haze and climate. Due to the low ...concentration levels of individual NOCs in the air, the utilization of accurate detection and quantification technologies becomes essential. For the first time, this study investigated the diurnal variation, chemical characteristics, and potential formation pathways of NOCs in urban ambient aerosols in Shanghai using a versatile aerosol concentration enrichment system (VACES) coupled with HPLC-Q-TOF-MS. The results showed that NOCs accounted over 60% of identified components of urban organic aerosols, with O/N < 3 compounds being the major contributors (>70%). The predominance of the positive ionization mode suggested the prevalence of reduced NOCs. Higher relative intensities and number fractions of NOCs were observed during nighttime, while CHO compounds showed an opposite trend. Notably, a positive correlation between the intensity of NOCs and ammonium during the nighttime was observed, suggesting that the reaction of ammonium to form imines may be a potential pathway for the formation of reduced NOCs during the nighttime. Seven prevalent types of reduced NOCs in autumn and winter were identified and characterized by an enrichment of CH2 long-chain homologues. These NOCs included alkyl, cyclic, and aromatic amides in CHON compounds, as well as heterocyclic or cyclic amines and aniline homologue series in CHN compounds, which were associated with anthropogenic activities and may be capable of forming light-absorbing chromophores or posing harm to human health. The findings highlight the significant contributions of both primary emissions and ammonium chemistry, particularly amination processes, to the pollution of reduced NOCs in Shanghai’s atmosphere.
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