One of the basic problems in the development and production process of moulds for injection moulding is the control of temperature conditions in the mould. Precise study of thermodynamic processes in ...moulds showed, that heat exchange can be manipulated by thermoelectrical means. Such system upgrades conventional cooling systems within the mould or can be a stand alone application for heat manipulation within it.
In the paper, the authors will present results of the research project, which was carried out in three phases and its results are patented in A686\2006 patent. The testing stage, the prototype stage and the industrialization phase will be presented. The main results of the project were total and rapid on-line thermoregulation of the mould over the cycle time and overall influence on quality of plastic product with emphasis on deformation control.
Presented application can present a milestone in the field of mould temperature and product quality control during the injection moulding process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
Average daily contributions (90% CI black bar) to PM10 in relative (%, left pie charts), OPAA and OPDTT per source’s mass in absolute (OPm in nmol/min m−3, middle bar plot) and OPAA and OPDTT per ...volume in relative (OPv in %, right bar plot) values grouped according to sources common activities. Arrows indicate (additional) associations between the sources.
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•Concentrations of PM10 at the site are comparable to other Alpine valleys, however, OP levels are higher compared to European sites.•Extensive tests with PMF were performed including organic tracers.•The most important sources of PM10, OP per µg of source as well as OP per m3 at the site are biomass burning and activities related to cement production.•Sources with important contributions to PM10 do not necessarily have high OP.•An unusual chloride-rich source was identified with high OP per µg of source.
Toxicity of particulate matter (PM) depends on its sources, size and composition. We identified PM10 sources and determined their contribution to oxidative potential (OP) as a health proxy for PM exposure in an Alpine valley influenced by cement industry. PM10 filter sample chemical analysis and equivalent black carbon (eBC) were measured at an urban background site from November 2020 to November 2021. Using an optimized Positive Matrix Factorization (PMF) model, the source chemical fingerprints and contributions to PM10 were determined. The OP assessed through two assays, ascorbic acid (AA) and dithiothreitol (DTT), was attributed to the PM sources from the PMF model with a multiple linear regression (MLR) model. Ten factors were found at the site, including biomass burning (34, 40 and 38% contribution to annual PM10, OPAA and OPDDT, respectively), traffic (14, 19 and 7%), nitrate- and sulphate-rich (together: 16, 5 and 8%), aged sea salt (2, 2 and 0%) and mineral dust (10, 12 and 17%). The introduction of innovative organic tracers allowed the quantification of the PM primary and secondary biogenic fractions (together: 13, 8 and 21%). In addition, two unusual factors due to local features, a chloride-rich factor and a second mineral dust-rich factor (named the cement dust factor) were found, contributing together 10, 14 and 8%. We associate these two factors to different processes in the cement plant. Despite their rather low contribution to PM10 mass, these sources have one of the highest OPs per µg of source. The results of the study provide vital information about the influence of particular sources on PM10 and OP in complex environments and are thus useful for PM control strategies and actions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Recent years have seen an increase in the use of wood for energy production of over 30 %, and this trend is expected to continue due to the current energy crisis and geopolitical instability. At ...present, residential wood burning (RWB) is one of the most important sources of organic aerosols (OAs) and black carbon (BC), posing a significant risk to air quality and health. Simultaneously, as a substantial aerosol source, RWB also holds relevance in the context of aerosol radiative effects and climate. While BC is recognized for its large light absorption cross-section, the role of OAs in light absorption is still under evaluation due to their heterogeneous composition and source-dependent optical properties. Existing studies that characterize wood-burning aerosol emissions in Europe primarily concentrate on urban and background sites and focus on BC properties. Despite the significant RWB emissions in rural areas, these locations have received comparatively less attention. The present scenario underscores the imperative for an improved understanding of RWB pollution, aerosol optical properties, and their subsequent connection to climate impacts, particularly in rural areas.
Residential wood combustion is a widespread practice in
Europe with a serious impact on air quality, especially in mountainous
areas. While there is a significant number of studies conducted in deep
...urbanized valleys and basins, little is known about the air pollution
processes in rural shallow hollows, where around 30 % of the people in mountainous areas across Europe live. We aim to determine the influence of
ground temperature inversions on wood combustion aerosol pollution in hilly,
rural areas. The study uses Retje karst hollow (Loški Potok, Slovenia)
as a representative site for mountainous and hilly rural areas in central and south-eastern Europe with residential wood combustion. Sampling with a mobile
monitoring platform along the hollow was performed in December 2017 and
January 2018. The backpack mobile monitoring platform was used for the
determination of equivalent black carbon (eBC) and particulate matter
(PM) mass concentrations along the hollow. To ensure high quality of mobile measurement data, intercomparisons of mobile instruments with
reference instruments were performed at two air quality stations during
every run. Our study showed that aerosol pollution events in the relief
depression were associated with high local emission intensities originating
almost entirely from residential wood burning and shallow temperature
inversions (58 m on average). The eBC and PM mass concentrations showed
stronger associations with the potential temperature gradient (R2=0.8) than with any other meteorological parameters taken into account
(ambient temperature, relative humidity, wind speed, wind direction, and precipitation). The strong association between the potential temperature
gradient and pollutant concentrations suggests that even a small number of
emission sources (total 243 households in the studied hollow) in similar
hilly and mountainous rural areas with frequent temperature inversions can
significantly increase the levels of eBC and PM and deteriorate local air quality. During temperature inversions the measured mean eBC and
PM2.5 mass concentrations in the whole hollow were as high as 4.5±2.6 and 48.0 ± 27.7 µg m−3,
respectively, which is comparable to larger European urban centres.
In this study, air temperature and precipitation seasonality and their correlation with large-scale atmospheric circulations over the Sava River Basin (SRB), i.e., over the areas of Slovenia, ...Croatia, and Serbia, are analyzed. We used daily air temperature and precipitation measurements from 12 meteorological stations for the period from 1981 to 2010. In addition, mean (Ta), maximum (Tmax), and minimum (Tmin) daily temperatures and daily precipitation (P) were included in the analysis. Temperature values were correlated with atmospheric circulation patterns (ACPs), i.e., daily indices Arctic Oscillation (AO), North Atlantic Oscillation (NAO), and Mediterranean Oscillation (MO) for the same study period. The daily air temperature and precipitation data were obtained from European Climate Assessment & Dataset (ECA&D). The results generally show increasing trends in air temperatures, mainly during the spring and summer seasons, but also non-significant trends for precipitation. Moreover, the correlation results show no or weak influence of ACPs on seasonal air temperatures and precipitation, but the dominant effects differ by ACP type as well as at different seasonal levels. Among the selected ACPs, MO proved to be the most significant for the Sava River Basin.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Small aethalometers are frequently used to measure equivalent black carbon (eBC) mass concentrations in the context of personal exposure and air pollution mapping through mobile measurements (MM). ...The most widely used is the microAethalometer (AE51). Its performance in the laboratory and field is well documented, however, there is not sufficient data in the context of its performance in different environments. In this investigation, we present the characterization of the performance of the AE51 through field unit-to-unit intercomparisons (IC), and against a reference absorption photometer from three MM campaigns conducted in drastically different environments. Five IC parameters were considered: i) study area, ii) location of IC, iii) time of day, iv) duration of IC, and v) correction for the filter-loading effect. We can conclude that it is crucial where and how long the IC have been performed in terms of the correlation between the mobile and reference instruments. Better correlations (R^2 ＞ 0.8, slope = 0.8) are achieved for IC performed in rural, and background areas for more than 10 minutes. In locations with more homogenous atmosphere, the correction of the loading effect improved the correlation between the mobile and reference instruments. In addition, a newer microAethalometer model (MA200) was characterized in the field under extreme cold conditions and correlated against another MA200 (R^2 ＞ 0.8, slope ≈ 1.0), AE51(R^2 ＞ 0.9, slope ≈ 0.9), and a stationary Aethalometer (AE33) across all wavelengths (R^2 ＞ 0.8, slope ≈ 0.7). For MA200, the loading effect was more pronounced, especially at the lower wavelengths, hence the correction of the loading effect is essential to improve the correlation against the AE33. The MA200 and AE51 proved to be robust and dependable portable instruments for MM applications. Real-world quality assurance of these instruments should be performed through field IC against reference instruments with longer durations in areas of slowly changing eBC concentration.
Onesnaženost zraka v urbanih območjih je pomemben dejavnik kakovosti življenja, nesporen pa je tudi vpliv kakovosti zraka na zdravje ljudi. Med pomembna onesnaževala urbanega ozračja že desetletja ...uvrščamo dušikov dioksid (NO2), po letu 2000 pa se vse več raziskav posveča tudi črnemu ogljiku (BC). V prispevku predstavljamo stacionarne in mobilne meritve črnega ogljika ter stacionarne meritve dušikovega dioksida v urbanem območju na dveh primerih. V prvem primeru gre za ugotavljanje vpliva ceste na kakovost zraka v neposredni okolici vrtca in nekdanje osnovne šole na Lavrici, v drugem primeru pa so prikazani rezultati meritev črnega ogljika na cestnem omrežju Kranja v gosti prostorski mreži.
Based on selected parameters, this paper aims to assess the physical-chemical water quality (PCWQ) of the Sava River in a part of the streamflow through Serbia, for the period 1997–2016. The ...spatio-temporal variations of surface water quality were determined by using One Way ANOVA, Pearson Correlation Index (PCI), Principal Component Analysis (PCA) and Confirmatory factor analysis (CFA). Water quality was assessed according to national and international water quality criteria. The parameter values are mostly within the permitted limits, however, on few stations, they were found to exceed the criteria levels. Better water quality was registered during the colder periods of the year. Also, better water quality was registered at SSt Šabac compared to SSt Jamena and SSt Ostružnica. PCI analysis shows a negative correlation between the T and DO and a positive correlation between the EC and PO
4
-P. The PCA defined four main components that determine the greatest impact on the temporal change of water quality. These are seasonal factors, eutrophication, sediment pollution and organic pollution. As shown in the algorithm results, as long as the covariance curve is included in the four factors, no related issues are detected in the goodness of fit of reflective indicators and interior and external quality is reported with excellence. The orthogonal model, thus, stands. The seasonality factor was dominant but it has been established that the pressures in the Sava River Basin exist, and there are most pronounced through the point sources of pollution.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
9.
Black carbon air pollution Glojek, Kristina; Gregorič, Asta; Ogrin, Matej
Dela (Univerza v Ljubljani. Oddelek za geografijo),
12/2018
50
Journal Article
Peer reviewed
The paper presents a study of air pollution caused by black carbon (BC) and fine particulate matter (PM) carried out in the rural area of the municipality of Loški Potok in the winter season of ...2017/2018. Measurements of pollutants were performed at two different locations, one at Retje, a village at the bottom of a karst depression, and the other on the top of the Tabor hill in settlement Hrib. The measurement results exposed the main sources of black carbon air pollution in this area: domestic heating with biomass (almost 80% of all black carbon emissions) and unfavorable meteorological conditions for dilution of pollutants during temperature inversions. Three times higher concentrations were measured at Retje during temperature inversions than in the days of mixed atmosphere. In the winter of 2017/18, the average concentrations in the Retje hollow were even higher than those of Ljubljana, which calls attention to the problem of polluted air in rural areas too.
Black carbon air pollution Kristina Glojek; Asta Gregorič; Matej Ogrin
Dela (Univerza v Ljubljani. Oddelek za geografijo),
12/2018
50
Journal Article
Peer reviewed
Open access
The paper presents a study of air pollution caused by black carbon (BC) and fine particulate matter (PM) carried out in the rural area of the municipality of Loški Potok in the winter season of ...2017/2018. Measurements of pollutants were performed at two different locations, one at Retje, a village at the bottom of a karst depression, and the other on the top of the Tabor hill in settlement Hrib. The measurement results exposed the main sources of black carbon air pollution in this area: domestic heating with biomass (almost 80% of all black carbon emissions) and unfavorable meteorological conditions for dilution of pollutants during temperature inversions. Three times higher concentrations were measured at Retje during temperature inversions than in the days of mixed atmosphere. In the winter of 2017/18, the average concentrations in the Retje hollow were even higher than those of Ljubljana, which calls attention to the problem of polluted air in rural areas too.
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