Bulk Collectors Research Articles

Effect of uniaxial strain on characteristic frequency of scaled SiGe HBT with embedded stress raiser

In order to further improve the high-frequency characteristics of highly scaled SiGe HBT and consider the compatibility with the mature CMOS technology, a new SiGe HBT structure is proposed by introducing an embedded Si1−yGey stress raiser to produce additional uniaxial stress in the bulk collector region. The energy-band configuration of multi-layered emitter has been investigated by the estimation of the strain effect, and then the influence of stress raiser on the electrical properties and frequency response has been studied by employing the SILVACO TCAD tools. The results show that the device performance has been enhanced to different degrees by altering the Ge fraction (y) in the stress raiser. At y = 0.3, the current gain is increased by approximately 6% compared to the case without stress in the collector region (y = 0). For the case of a uniform Si0.75Ge0.25 base, the cut-off frequency (fT) and the maximum oscillating frequency (fmax) are, respectively, peaked at 507.7 GHz and 730.7 GHz. Approximately 29.1% improvement in fT and 71.5% improvement in fmax have been achieved for the proposed HBT device in comparison with an equivalent traditional SiGe HBT. At y = 0.1, the frequency characteristic is considered the best due to the maximum of fT × fmax product.

New insights related to the flotation of covellite in porphyry ores

Covellite usually occurs accompanying other copper minerals, like chalcopyrite and chalcocite, but there are few studies on covellite flotation. The effect of collectors O-isopropyl-N-ethyl thionocarbamate (IPETC) and potassium amyl xanthate (PAX) and pH on covellite and pyrite flotation was investigated through a Hallimond tube test using pure covellite and pyrite and a Denver cell test using porphyry ore. Pure covellite and pyrite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR). Moreover, the covellite was characterized using scanning electron microscopy coupled to energy dispersive spectroscopy (SEM-EDS). Porphyry ore was characterized by automated mineralogy using scanning electron microscopy (QEMSCAN®). Design of experiments was utilized to identify the factors with a statistical influence (ANOVA) and obtain the optimal flotation conditions using response surface methodology (RSM) and desirability function. ANOVA test demonstrated that the factors that influence covellite behavior are the collector type and dosage. The results obtained on pure minerals shows that with a high PAX concentration and low pH, it is possible to carry out bulk flotation with recoveries of 93% covellite and 90 % pyrite, and with a low IPETC dosage and high pH, it is possible to get a selective flotation with around 81% covellite and 20% pyrite recoveries. These results were determined using RSM and desirability function, and corroborated with the Hallimond tube test. Then, the flotation results of mixture covellite-pyrite show that selective flotation is feasible with IPETC at alkaline pH with a low dosage displaying recoveries of 97 % covellite and 53 % pyrite. Also, bulk flotation is feasible with PAX at a pH of 8 and a high collector concentration with recoveries of 96% covellite and 88% pyrite. The results show that covellite recovery is not pH-dependent. The Denver cell test with a porphyry ore shows a selective flotation with IPETC at a pH of 11 with a low collector dosage (5 g/ton), achieving recoveries of 92% covellite and 39% pyrite. Also, recoveries of 85% covellite and 75% pyrite were observed for a bulk flotation with IPETC at pH = 8 at the same collector dosage. Therefore, the IPETC can be used as a selective or bulk collector when varying the pH and collector concentration. These results demonstrate that covellite flotation performances remain constant over a wide range of pH values, which allows a selective separation from other sulfides such as pyrite.

An optimized sample preparation and analysis method for the determination of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in the atmospheric bulk deposition samples

A method based on solid phase extraction (SPE), gas chromatography tandem mass spectrometry (GC-MS/MS) and gas chromatography with electron capture detector (GC-ECD) was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in atmospheric deposition samples. Six indicator PCB congeners were analysed by GC-ECD equipped with two micro electron-capture detectors and two gas chromatographic columns, while 12 PAH compounds were analysed by GC-MS/MS. Solid phase extraction on silica sorbent proved suitable for accumulation of PAHs and PCBs from deposited matters. The extraction procedure was based by passing the whole sample volume through a silica cartridge with dichloromethane and n-hexane as the eluting solvents. Two different performances of a bulk collector were compared. The method was validated using field total deposited samples collected monthly over a year by bulk method at an urban background station in Zagreb, Croatia. The levels and occurrence of PCBs corresponded to global environmental pollution, with the deposition rates of ∑6PCBs between 6 - 28 ng m−2 d−1. The deposition rates of ∑12PAHs varied between 132 and 714 ng m−2 d−1 during the warm period, whereas it achieved a significantly higher range of 171 to 1069 ng m−2 d−1 in the cold period.

Ambient Atmospheric Deposition of Anthropogenic Microfibers and Microplastics on the Western Periphery of Europe (Ireland).

Microfibers (mf) are the most common type of microplastic in the environment. Few studies have focused on their abundance in atmospheric deposition in background environments. In the current study, we collected wet-only and bulk rainfall from four precipitation chemistry monitoring stations, primarily located in coastal areas around Ireland. Anthropogenic mf were observed in all samples; the average deposition across the four study sites was 80 mf m-2 day-1. Wet-only mf deposition was 70 mf m-2 day-1 compared with bulk deposition of 100 mf m-2 day-1. The wet-only collectors were estimated to capture ∼70% of the bulk collectors, suggesting that dry deposition makes up at least 30% of total deposition. Meteorological variables, i.e., relative humidity, rainfall volume, wind speed, and wind direction, were significantly related to mf abundance, suggesting that rainfall washout and air mass movement are important predictors of mf deposition in background regions. In total, 15% of all anthropogenic mf were identified as plastic. The most abundant polymer type was polyester or polyethylene terephthalate at 71%, followed by polyacrylonitrile at 11%, polyethylene at 11%, and polypropylene at 4%. The average deposition of plastic mf was 12 mf m-2 day-1.

Evaluation of collector performance at the bubble-particle scale

Particle attachment and detachment in froth flotation are complex processes and their measurement presents many challenges. Of particular interest is the effect of collectors at the bubble-particle scale, in order to assess the strength or collecting ability of these reagents. However, studies of the effect of collectors on particle attachment at the bubble-particle scale are scarce. In this work, we propose a methodology to characterise collector strength by measuring the attachment rate of particles to a capillary-pinned bubble. An image processing technique was developed to quantify bubble surface coverage over time, which was then used to determine particle attachment kinetics. The image analysis strategy is based on the sessile drop method and uses curve fitting to determine accurately the particle coverage. The methodology was used to assess the collecting ability of three chalcopyrite collectors. Interestingly, although very similar contact angle measurements were found for two of the collectors, they showed distinctly different particle attachment kinetics. It is proposed that this particle-bubble attachment method can be used to gain additional information not currently available from either contact angle measurements or bulk collector performance tests.

Atmospheric depositional characteristics of 210Po, 210Pb and some trace elements in İzmir, Turkey

The total atmospheric deposition rates of 210Po, 210Pb and some trace elements (Li, Be, B, Na, Mg, Al, Si, P, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Ba, La, Ce, Tl, Pb and U) have been determined for a year (November 2014–October 2015) collecting samples monthly using bulk collectors at three sites in İzmir, Turkey (Aliağa, Bornova, and Dikili). The annual 210Po flux was found as 34.8 Bq m−2 y−1 in Aliağa, 29.2 Bq m−2 y−1 in Bornova, 21.1 Bq m−2 y−1 in Dikili; the annual 210Pb flux was found as 41.7 Bq m−2 y−1 in Aliağa, 43.6 Bq m−2 y−1 in Bornova, 28.6 Bq m−2 y−1 in Dikili. The annual depositional fluxes of 210Po and 210Pb were generally correlated with the amount of precipitation. For most trace elements the highest fluxes were observed in Aliağa, while the lowest fluxes were observed in Dikili.

Modification of the isotopic composition of rainfall by throughfall and stemflow: The case of Scots pine and downy oak forests under Mediterranean conditions

AbstractMost hydrological studies based on stable water isotopes (18O and D) use the isotopic composition of rainfall as input signal. Although stable water isotopes are conservative tracers, previous studies have shown that canopies modify the isotopic composition of rainfall. At present, there is a scientific agreement about the factors involved in isotopic modification, but the effect of each factor and the magnitude of the isotopic shift are still not clear. In this study, we analyse at an interevent and intraevent basis the spatio‐temporal differences between the isotopic composition of rainfall, throughfall, and stemflow for two different species (Pinus sylvestris L. and Quercus pubescens Willd). The aim of the study is to analyse the isotopic modification that takes place in throughfall and stemflow and how meteorological variables and structural forest characteristics influence the observed changes. Rainfall and throughfall were sampled by a combination of bulk and sequential collectors, whereas stemflow was collected only by bulk collectors. Results showed that the isotopic modification occurred in both directions, although stemflow was consistently more enriched than throughfall. Despite the contrasting canopy structures, no significant differences between species were found. Moreover, the intraevent analysis suggested that all fractionation factors could occur during one event, but evaporation or isotopic exchange would have a higher impact at the beginning of rainfall, whereas canopy selection processes would be more important at the end of rainfall. Our results emphasize the importance of considering the isotopic composition of throughfall and stemflow in isotope‐related studies in forested catchments.

Bulk deposition of atmospheric inorganic nitrogen in mountainous heathland ecosystems in North-Western Spain

Nitrogen (N) deposition has been identified as one of the main traits of terrestrial ecosystems, affecting their structure and functioning. However, few studies have been developed under natural field conditions to evaluate the amount of N deposition in low nutrient status heathland ecosystems. Therefore, a field experiment was carried out to investigate the bulk inorganic N inputs in mountainous heathlands of North-Western Spain. Two study sites (La Majúa and San Isidro) were selected on the south side of the Cantabrian Mountains, as a representative monitoring of N-sensitive ecosystems. Three replicated bulk collectors and one rain gauge were installed at each study site to collect monthly bulk deposition samples over three-year period (2011–2014). Bulk inorganic N deposition was different between the study sites (2.81kgNha−1yr−1 in La Majúa and 4.56kgNha−1yr−1 in San Isidro), but showed the same seasonal dynamic, with higher N deposition rate in the wet period (October to April) compared to the dry period (May to September). Annual bulk NO3− deposition was comparable to annual bulk NH4+ deposition in La Majúa (1.42 vs. 1.39kgNha−1yr−1), and higher in San Isidro (2.89 vs. 1.67kgNha−1yr−1). San Isidro displayed a characteristic bulk NH4+/NO3− deposition ratio below 1 of industrialized areas (0.58), while La Majúa displayed a bulk NH4+/NO3− deposition ratio close to 1 (0.98), distinctive of an intermediate situation between industrialized and agricultural areas. Total bulk inorganic N depositions observed in the present field study are consistent with the modelled estimation of N depositions for North-Western Spain, but only San Isidro was consistent with the estimated dominance of oxidized N over reduced N.

Inorganic ions and trace metals bulk deposition at an Atlantic Coastal European region

The inorganic chemical composition (major ions and trace metals) of bulk deposition samples collected monthly with bulk collectors at seven Atlantic Coastal European cities (Galicia, Northwest of Spain) during wet season (September 2011 to March 2012) has been assessed and compared. Trace metals (Al, As, Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) were analysed in soluble fraction and non-soluble fraction (after acid extraction) of the bulk deposition by inductively coupled plasma-mass spectrometry. Major inorganic ions (Cl−, NO3 −, SO4 2−, Na+, K+, Ca2+, Mg2+ and NH4 +) were analysed in the soluble fraction of the bulk deposition by capillary zone electrophoresis. Univariate analysis (ANOVA and Multiple Range Test) according to the location of each sampling site was performed. Results also suggest a great influence of cleaner Atlantic air masses. After partition coefficients and enrichment factor estimation, similar sources could be assigned for the ionic and metal composition of bulk deposition at seven urban sites.

Cloud water composition during HCCT-2010: Scavenging efficiencies, solute concentrations, and droplet size dependence of inorganic ions and dissolved organic carbon

Abstract. Cloud water samples were taken in September/October 2010 at Mt. Schmücke in a rural, forested area in Germany during the Lagrange-type Hill Cap Cloud Thuringia 2010 (HCCT-2010) cloud experiment. Besides bulk collectors, a three-stage and a five-stage collector were applied and samples were analysed for inorganic ions (SO42−,NO3−, NH4+, Cl−, Na+, Mg2+, Ca2+, K+), H2O2 (aq), S(IV), and dissolved organic carbon (DOC). Campaign volume-weighted mean concentrations were 191, 142, and 39 µmol L−1 for ammonium, nitrate, and sulfate respectively, between 4 and 27 µmol L−1 for minor ions, 5.4 µmol L−1 for H2O2 (aq), 1.9 µmol L−1 for S(IV), and 3.9 mgC L−1 for DOC. The concentrations compare well to more recent European cloud water data from similar sites. On a mass basis, organic material (as DOC × 1.8) contributed 20–40 % (event means) to total solute concentrations and was found to have non-negligible impact on cloud water acidity. Relative standard deviations of major ions were 60–66 % for solute concentrations and 52–80 % for cloud water loadings (CWLs). The similar variability of solute concentrations and CWLs together with the results of back-trajectory analysis and principal component analysis, suggests that concentrations in incoming air masses (i.e. air mass history), rather than cloud liquid water content (LWC), were the main factor controlling bulk solute concentrations for the cloud studied. Droplet effective radius was found to be a somewhat better predictor for cloud water total ionic content (TIC) than LWC, even though no single explanatory variable can fully describe TIC (or solute concentration) variations in a simple functional relation due to the complex processes involved. Bulk concentrations typically agreed within a factor of 2 with co-located measurements of residual particle concentrations sampled by a counterflow virtual impactor (CVI) and analysed by an aerosol mass spectrometer (AMS), with the deviations being mainly caused by systematic differences and limitations of the approaches (such as outgassing of dissolved gases during residual particle sampling). Scavenging efficiencies (SEs) of aerosol constituents were 0.56–0.94, 0.79–0.99, 0.71–98, and 0.67–0.92 for SO42−, NO3−, NH4+, and DOC respectively when calculated as event means with in-cloud data only. SEs estimated using data from an upwind site were substantially different in many cases, revealing the impact of gas-phase uptake (for volatile constituents) and mass losses across Mt. Schmücke likely due to physical processes such as droplet scavenging by trees and/or entrainment. Drop size-resolved cloud water concentrations of major ions SO42−, NO3−, and NH4+ revealed two main profiles: decreasing concentrations with increasing droplet size and “U” shapes. In contrast, profiles of typical coarse particle mode minor ions were often increasing with increasing drop size, highlighting the importance of a species' particle concentration size distribution for the development of size-resolved solute concentration patterns. Concentration differences between droplet size classes were typically < 2 for major ions from the three-stage collector and somewhat more pronounced from the five-stage collector, while they were much larger for minor ions. Due to a better separation of droplet populations, the five-stage collector was capable of resolving some features of solute size dependencies not seen in the three-stage data, especially sharp concentration increases (up to a factor of 5–10) in the smallest droplets for many solutes.

Analysis of bulk precipitation chemistry in Serbia for the period from 1982 to 2010

Bulk precipitation samples collected daily through bulk collectors at eight meteorological stations in Serbia were analyzed for their chemical composition. The data covers time series, from 20 to 28 years, in the period between 1982 and 2010. The most abundant ion in the samples was sulfate. Only 0.17 % of all samples were from strong acid rains (pH < 3.5). The relatively high average pH values (5.94–6.26) of the collected precipitation indicate the neutral or alkaline nature of local rainwater. Trends in both the annual amount and the composition of precipitation were tested by the nonparametric Mann–Kendall test and Sen’s slope estimator. Significant increasing trend of precipitation was identified for almost all stations. Rebuilding activities after the bombing of Serbia in 1999 were identified as a possible anthropogenic cause of the sharp increase of some ions (Ca2+) in the first year following the bombing. The origin of air masses arriving at one particular station was examined using two-dimensional backward trajectories. Western sectors (W, SW and NW) accounted for almost half (44.3 %) of all rainy days, while eastern sectors (SE, E and NE) brought only 10.4 % of all rainy days. The distribution, per sector, of volume-weighted concentrations of sulfate, nitrate, ammonium, calcium, potassium, magnesium, chloride and sodium ions, as well as the amount of precipitation and its pH values for one station, was also analyzed. Rainwater from the SE and S sectors was the most polluted.

A new dust transport approach to quantify anthropogenic sources of atmospheric PM10 deposition on lakes

Windblown dust simulations are one of the most uncertain types of atmospheric transport models. This study presents an integrated PM10 emission, transport and deposition model which has been validated using monitored data. This model characterizes the atmospheric phosphorus load focusing on the major local sources within the Lake Simcoe airshed including paved and unpaved roads, agricultural sources, construction sites and aggregate mining sources. This new approach substantially reduces uncertainty by providing improved estimates of the friction velocities than those developed previously. Modeling improvements were also made by generating and validating an hourly windfield using detailed meteorology, topography and land use data for the study area. The model was used to estimate dust emissions generated in the airshed and to simulate the long-range transport and deposition of PM10 to Lake Simcoe. The deposition results from the model were verified against observed bulk collector phosphorus concentration data for both wet and dry deposition. Bulk collector data from stations situated outside the airshed in a remote, undeveloped area were also compared to determine the background contribution from distant sources.

Local Enhancement of 210Po Atmospheric Flux at a Site in İzmir, Turkey

The annual atmospheric deposition rates of 210Po and 210Pb were determined in Izmir, Turkey. The samples were collected from 18 November 2008 to 17 November 2009. The annual 210Po deposition flux was determined as 44.1 ± 3.0 Bq m−2 year−1, while 210Pb flux was calculated as 73.1 ± 4.4 Bq m−2 year−1 using bulk collectors. The monthly deposition fluxes of 210Po and 210Pb were correlated with the amount of precipitation. The activity concentrations of the samples were found to vary between 5.7 ± 1.1 and 167.1 ± 7.5 mBq L−1, with an average value of 41.2 ± 1.9 mBq L−1 for 210Po; and between 5.3 ± 0.6 and 265.7 ± 10.8 mBq L−1, with an average value of 67.3 ± 2.7 mBq L−1 for 210Pb. The activity ratios of 210Po/210Pb in the samples ranged from 0.16 to 3.39, with an average value of 0.80. During the course of the study, 210Po enhancement from both natural and anthropogenic sources was observed.

Chemical and isotopic characterisation of bulk deposition in the Louros basin (Epirus, Greece)

About 120 rainwater samples were collected through a network of five bulk collectors in the area of the Louros basin (Epirus, Greece) during the wet season from October 2008 to August 2009. They were analysed for their isotopic (δD and δ18O) and chemical (H+, Na+, K+, Mg2+, Ca2+, NH4+, F−, Cl−, Br−, NO3−, SO42−) composition.A local meteoric water line (δD‰=5.80±0.02 δ18O‰+0.02±0.12) and a local isotopic lapse rate (−0.18 δ18O‰/100m) were obtained considering the volume-weighted means of the five sampling sites. These results agree well with those obtained in nearby areas.The chemical composition of the samples allows to identify an almost entirely marine origin for chloride and sodium with decreasing deposition values at increasing distance from the coast. Nitrate and ammonium are almost completely of anthropogenic origin, calcium and potassium are overwhelmingly geogenic, sulphate has a prevailingly anthropogenic origin with a significant marine contribution and magnesium has a mixed marine and soil dust origin. Finally, as for most of the Mediterranean area, rainwater acidity is buffered by the dissolution of the abundant geogenic carbonate aerosol.

Roads as nitrogen deposition hot spots

Mobile sources are the single largest source of nitrogen emissions to the atmosphere in the US. It is likely that a portion of mobile-source emissions are deposited adjacent to roads and thus not measured by traditional monitoring networks, which were designed to measure long-term and regional trends in deposition well away from emission sources. To estimate the magnitude of near-source nitrogen deposition, we measured concentrations of both dissolved inorganic nitrogen (DIN) and total dissolved nitrogen (inorganic + organic) (TDN) in throughfall (i.e., the nitrogen that comes through the forest canopy) along transects perpendicular to two moderately trafficked roads on Cape Cod in Falmouth MA, coupled with measurements of both DIN and TDN in bulk precipitation made in adjacent open fields at the same transect distances. We used the TDN throughfall data to estimate total nitrogen deposition, including dry gaseous nitrogen deposition in addition to wet deposition and dry particle deposition. There was no difference in TDN in the bulk collectors along the transects at either site; however TDN in the throughfall collectors was always higher closest to the road and decreased with distance. These patterns were driven primarily by differences in the inorganic N and not the organic N. Annual throughfall deposition was 8.7 (±0.4) and 6.8 (±0.5) TDN kg N ha−1 year−1 at sites 10 and 150 m away from the road respectively. We also characterized throughfall away from a non-road edge (power line right-of-way) to test whether the increased deposition observed near road edges was due to deposition near emission sources or due to a physical, edge effect causing higher deposition. The increased deposition we observed near roads was due to increases in inorganic N especially NH4 +. This increased deposition was not the result of an edge effect; rather it is due to near source deposition of mobile source emissions. We scaled these results to the entire watershed and estimate that by not taking into account the effects of increased gaseous N deposition from mobile sources we are underestimating the amount of N deposition to the watershed by 13–25 %.

Tracing industrial sulfur contributions to atmospheric sulfate deposition in the Athabasca oil sands region, Alberta, Canada

Anthropogenic S emissions in the Athabasca oil sands region (AOSR) in Alberta, Canada, affect SO4 deposition in close vicinity of industrial emitters. Between May 2008 and May 2009, SO4-S deposition was monitored using open field bulk collectors at 15 sites and throughfall collectors at 14 sites at distances between 3 and 113 km from one of the major emission stacks in the AOSR. At forested plots >90 km from the operations, SO4 deposition was ∼1.4 kg SO4-S ha−1 yr−1 for bulk deposition and ∼3.3 kg SO4-S ha−1 yr−1 for throughfall deposition. Throughfall SO4 deposition rates in the AOSR exceeded bulk deposition rates at all sites by a factor of 2–3, indicating significant inputs of dry deposition especially under forest canopies. Both bulk and throughfall SO4 deposition rates were elevated within 29 km distance of the industrial operations with deposition rates as high as 11.7 kg SO4-S ha−1 yr−1 for bulk deposition and 39.2 kg SO4-S ha−1 yr−1 for throughfall at industrial sites. Sulfur isotope ratio measurements of atmospheric SO4 deposited in the AOSR revealed that at a few selected locations 34S-depleted SO4, likely derived from H2S emissions from tailing ponds contributes to local atmospheric SO4 deposition. In general, however, δ34S values of SO4 deposition at distant forested plots (>74 km) with low deposition rates were not isotopically different from δ34S values at sites with high deposition rates in the AOSR and are, therefore, not suitable to determine industrial S contributions. However, O isotope ratios of atmospheric SO4 in bulk and throughfall deposition in the AOSR showed a distinct trend of decreasing δ18O-SO4 values with increasing SO4 deposition rates allowing quantification of industrial contributions to atmospheric SO4 deposition. Two-end-member mixing calculations revealed that open field bulk SO4 deposition especially at industrial sites in close proximity (<29 km) to the operations is significantly (17–59%) affected by industrial S emissions and that throughfall generally contained 49–100% SO4 of industrial origin. Hence, it is suggested that δ18O values of SO4 may constitute a suitable tracer for quantifying industrial contributions to atmospheric SO4 deposition in the AOSR.

Trend in chemical composition of precipitation during 2005–2009 at a rural station of Bhubaneswar, eastern India

Precipitation samples collected during 2005- 2009 from a rural forest station of Bhubaneswar were ana- lyzed for their chemical composition. The samples were collected through a wet-only (WO) collector and two bulk (B1 and B2) collectors. The ions were evenly balanced indicating good data quality. The overall pH of rainwater was slightly acidic and ~47% of all rain events during the period were acidic (pH<5.6). Multilinear regression analy- sis showed relation between the free acidity (H + ) and other components in rainwater. Enrichment factors (EF) of the major components with respect to their sources such as marine and crustal were calculated. Maximum EF was ob- served for NO3 � for both marine and crustal sources for all the three collectors. Source apportionments were also car- ried for the ions. Trend analysis showed continuous increase in most of the ions over years during the study period driven by anthropogenic emissions. Statistical/factorial analysis established correlation among different ions.

Towards harmonization of forest deposition collectors - case study of comparing collector designs

In recent years the harmonization of methods in the frame of the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) operating under the UNECE Convention on Long-range Transboundary Air Pollution (CLRTAP) has been intensified. Among the C-actions of the FutMon project (LIFE07 ENV/D/000218; 2009-2010) the C1-Dep-22(SI) action was established with the goal to harmonize and develop the deposition monitoring procedures and sampling methods. The sampling equipment, spatial design of sampling plots and sampling frequency throughout Europe vary considerably. Therefore a step-by-step approach was made where the harmonized sampling equipment was developed and tested first. The selected collectors were installed at one observation plot of each participating country where measurements of throughfall and bulk deposition were run in parallel with the national collectors for a period of one year. To evaluate the agreement between methods, different statistical analyses were used including Altman-Bland plots, model II regression, and repeated measures ANOVA. Preliminary results from the “Intensive forest ecosystem monitoring plot” plot Brdo in NW Slovenia show a good agreement between national and harmonized bulk (both funnel-type) collectors, while comparison of throughfall measurements indicates systematic bias between harmonized (funnel-type) and national (gutter-type) collectors.

Spatial Variation of the Precipitation Chemistry in the Thrace Region of Turkey

Pollutants affect not only the environment in which they originate since they are also transported by air currents to other locations. For this reason, air pollution is a global problem for all countries and the air and water quality need to be monitored carefully. More information on precipitation chemistry is required to determine the source of pollution as well as its effects on the ecosystems. In this study, precipitation chemistry has been analyzed for the first time by using simple bulk collectors located at four different sites in Northwest Turkey for a period of two years. About 650 sequential rainwater samples were collected and analyzed for pH, electrical conductivity, anions such as SO 2- 4 , NO - 3 , Cl - , and cations such as Na + , K + , Mg 2+ , Ca 2+ , and NH + 4 . The selected sites were under the effect of different environmental factors. Our results showed that the highest SO 2- 4 and NO - 3 concentrations were measured in the Northwest of the research area. Additionally, it has been found that Ca 2+ ions are abundant within all rainwater samples.

Deposition of7Be to Bermuda and the regional ocean: Environmental factors affecting estimates of atmospheric flux to the ocean

[1] The distribution of 7Be in ocean surface waters is used as tracer of upper ocean transport and atmospheric deposition processes. However, there is very little ocean deposition data available to characterize the temporal and spatial input of 7Be to the oceans and test model results. Here we measure the deposition of 7Be in bulk collectors at two sites at Bermuda over a span of nearly 2 years (April 2007 to January 2009) and compare these rates to the flux required to sustain the inventory of 7Be measured in the nearby Sargasso Sea. The Tudor Hill collector site undersampled (by ∼40%) both the rainfall compared to other Bermuda sites and the 7Be flux required for the ocean inventory. On the other hand, the 7Be flux captured at the Bermuda Institute of Ocean Sciences station site (0.048 dpm cm−2 d−1) matched that expected from the ocean observations. Previously measured long-term atmospheric concentration of 7Be in surface air at Bermuda was used to estimate deposition velocities and scavenging ratios, and our estimates in this marine environment were found to be similar to those measured in continental regions. The deposition of 7Be to the oceans is overwhelmingly determined by wet processes; dry deposition to the ocean surface accounts for only a few percent, at most, of the total deposition to the ocean. We place these measurements in a longer-term and large-scale spatial context by using climatological rainfall data on Bermuda and ocean rainfall estimates from the Global Precipitation Climatology Program and Tropical Rainfall Measuring Mission.