A comprehensive assessment of endocrine-disrupting chemicals in an Indian food basket: Levels, dietary intakes, and comparison with

Endocrine-disrupting chemicals (EDCs) in diet are a health concern and their monitoring in food has been introduced in the European Union. In developing countries, EDC dietary exposure data are scarce, especially from areas perceived as pollution hotspots, including industrialized countries like India. Several persistent organic pollutants (POPs) act as EDCs and pose a pressure to human health mainly through dietary exposure. In the present study, a range of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dioxins and furans were measured in several food items collected from Indian urban (Delhi) and peri-urban (Dehradun) areas. Food basket contamination data were used to estimate EDC dietary exposure and compare it with that of the average European population estimated from available monitoring data. All the target contaminants were found in most food items, especially in dairies and meat products. OCPs were the main contributers to the measured EDC contamination. Food supplied to Delhi's markets had higher EDC contamination than that supplied to the peri-urban market in Dehradun. Despite lax compliance and control measures, Indian dietary exposure of OCPs and PBDEs were comparable with that of Europe and were lower for PCBs and dioxins. Higher meat consumption in Europe only partly explained this pattern which was driven also by the higher EDC residues in some European food items. A substantial part of endocrine disrupting potential in the diet derives from food and animal feeds internationally traded between developed and developing countries. With increasingly globalized food systems, internationally harmonized policies on EDC content in food can lead to better protection of health in both these contexts

Selective photocatalysis using metal oxides..

Import 26/06/2013V předložené diplomové práci je uvedeno ověřování literárních poznatků a studium odstraňování dusitanů a dusičnanů z vod pomocí fotokatalýzy. V rámci práce byl testován vliv způsobu přípravy fotokatalyzátorů, vliv organického modifikátoru, vliv vlnové délky použitého světelného zdroje a vlivu dopantu TiO2. V teoretické části práce je proveden rozbor problematiky. Experimentální část práce řeší rozšíření spektra vhodných materiálů k jejich použití jako fotokatalyzátorů a rovněž i vliv jednotlivých parametrů na proces fotokatalýzy dusitanů a dusičnanů. Údaje literární rešerše jsou konfrontovány s naměřenými daty a jsou zpracovány do ucelených závěrů.In the presented thesis is described verification of the literary knowledge and studied nitrite and nitrate removal from water by photocatalysis. During the work were tested impact of a preparation method of photocatalysts, the influence of a organic modifier, the impact of a light source wavelength and the impact of a TiO2 dopant. In the theoretical part of the thesis the problematic is discussed. The experimental part of the thesis deals with a wide range of suitable materials for photocatalytic usage and also the impact of each parameter on the process of photocatalysis of nitrites and nitrates. Reviewed data are confronted with the measured data and processed into compact conclusions.Prezenční546 - Institut environmentálního inženýrstvívýborn

Photocatalysts and threir function in water cleaning from nitrite and nitrate

Import 04/07/2011Předkládaná bakalářská práce se zabývá ověřováním literárních poznatků a studiem odstraňování dusitanů a dusičnanů z vod pomocí fotokatalýzy. V rámci práce byl testován vliv množství fotokatalyzátoru, vliv koncentrací dusitanů a dusičnanů, vliv pH a vliv organického modifikátoru. Testy byly provedeny pro klasický fotokatalyzátor P 25 a pro TiO2 vázaný na kaolinu. Pro účely vyhodnocení experimentů byla pro některé analyty testována i vhodnost jednotlivých analytických postupů. V teoretické části práce je proveden rozbor problematiky. Experimentální část práce se zabývá jednotlivými experimenty pro praktické ověření dříve získaných poznatků. Údaje literární rešerše jsou konfrontovány s naměřenými daty.The present thesis discuss the verification of knowledge and literary study of nitrite and nitrate removal from water by photocatalysis. The thesis tested the influence of quantity of photocatalyst, the effect of nitrite and nitrate concentrations, pH influence and the influence of organic modifier. Tests were carried out for classical photocatalyst P 25 and TiO2 bound to kaolin. For evaluation purposes of experiments were some analytes tested for the suitability of various analytical procedures. The theoretical part is an analysis of the problem. The experimental part deals with various practical experiments for the verification of previously acquired knowledge. Details of literary research are confronted with the measured data.Prezenční546 - Institut environmentálního inženýrstvívýborn

Theoretical and experimental study of phase transformation temperatures of steels

Hlavními kritérii v oblastech optimalizace nastavení parametrů metalurgických procesů, zejména technologie odlévání a následného tuhnutí ocelí, jsou teploty fázových transformací ve vysokoteplotní oblasti: teplota likvidu (TL), teplota peritektické transformace (TP) a teplota solidu (TS). Vzhledem k technologickému i ekonomickému významu znalosti přesných teplot fázových transformací je stále věnována značná pozornost metodám jejich stanovení. Existují dva přístupy, tradiční experimentální metody, nejčastěji zastoupeny metodami termické analýzy a teoretické metody využívající ICT. V rámci předkládané disertační práce byla provedena rešerše literárních poznatků zabývajících se problematikou termické analýzy s ohledem na získávání TL, TP a TS. Byla získána originální experimentální data (TL, TP a TS) 18 vzorků ocelí metodami Diferenční termické analýzy a Přímé termické analýzy. Získaná experimentální data byla vyhodnocena a byl proveden výpočet průměru, směrodatné odchylky a variačního koeficientu. Na základě získaných údajů bylo zjištěno, že metody diferenční a přímé termické analýzy jsou nastaveny správně a výsledky jsou reprodukovatelné a porovnatelné. Výsledky termické analýzy vykazují vysokou míru konzistence a nízkou variabilitu. Byl proveden výpočet TL, TP a TS s využitím empirických modelů, a byl také proveden jejich výpočet v software Thermo-Calc metodou CALPHAD a v software InterDendritic Solidification metodou Phase Field. Vypočítaná data byla verifikována, konfrontována a diskutována s daty uváděnými v dostupné literatuře. Byla ověřena jejich shoda s výpočty empirických modelů a s výpočty software. Na základě analýzy výsledků empirických modelů a jejich shody s experimentálními výsledky a výsledky software, byl vytvořen nový empirický model (NEM), určený k výpočtu teplot fázových transformací TL, TP a TS. V principu se jedná o kalkulátor, v němž jsou implementovány vybrané empirické modely v tabulkovém editoru EXCEL. Průměr výsledků těchto modelů je pak výslednou teplotou TL, TP nebo TS. Výsledky empirických modelů jsou dále statisticky analyzovány. Na základě statistické analýzy byly vyloučeny modely, které poskytovaly výsledky značně odchýlené a tím značně negativně ovlivňovaly výsledek modelu. V případě teploty peritektické transformace byl využit pouze jeden model. Výsledky NEM byly porovnány a verifikovány s výsledky experimentů, s výpočty empirických vztahů a s výpočty software. Vytvořená aplikace je jednoduchým, nízkonákladovým a spolehlivým prostředkem pro výpočet TL, TP a TS. Hlavní přínos disertační práce spočívá v získání originálních dat a rozšíření databáze termo-fyzikálních a termodynamických vlastností ocelí. Data mohou být využita pro optimální nastavení licích podmínek v oboru odlévání ocelí. Dále pak lze data využít jako vstupní data pro software, který umožňuje modelování procesů odlévání ocelí a následného tuhnutí (např. Magmasoft, Procast). Data lze využít také k úpravě databází termodynamických software. Získané nové poznatky mohou přispět k rozvoji oborů metalurgie, slévárenství a materiálového inženýrství, metod termické analýzy a fyzikálně-numerického modelování. V důsledku tedy umožní optimalizaci procesů odlévání a tuhnutí ocelí, kde je cílem získat kvalitnější a energeticky méně nákladný produkt.The key parameters, in the area of parameters optimization of metallurgical processes, in particular the technology of casting and subsequent solidification of steel, are the transformation temperatures in high temperature region: liquidus temperature (TL), peritectic transformation temperature (TP) and solidus temperature (TS). Due to the technological, and consequently economical, importance of the knowledge of correct phase transformation temperatures, significant attention is still paid to the methods of its determination. There are two main approaches, traditional experimental methods, most often represented by thermal analysis methods and theoretical methods using ICT. The dissertation thesis deals with study of TL, TP and TS. A research was performed with focus on the topic of thermal analysis, with regard to the acquisition. Original experimental data (TL, TP and TS) of 18 samples of steel were obtained by Differential Thermal Analysis and Direct Thermal Analysis methods. The obtained experimental data were evaluated and a basic statistical analysis was performed. Based on the obtained data, it was found that the differential and direct thermal analysis methods are set correctly and the results are reproducible and comparable. Thermal analysis results shows high level of consistency and low variability. The TL, TP, and TS calculations were performed using existing empirical models, obtained by research and were calculated with Thermo-Calc by CALPHAD method and with InterDendritic Solidification by Phase Field method. The calculated data has been verified, confronted and discussed with data published in literature, and its compliance with empirical models and software calculations has been verified. Based on the analysis of the empirical equations results and software and its consistency with the experimental results, the new empirical model (NEM) for the calculation of TL, TP and TS was created. Basically, it is a calculator, where selected empirical equations are implemented, all suited in the EXCEL editor. The mean value of the results is then the final temperature TL, TP or TS. The results of the empirical models are further analysed statistically and the standard deviation, variation coefficient and variation range are evaluated. Based on statistical analysis, the equations that yielded results significantly deviated and thus adversely affecting the outcome of the model, were excluded. In case of peritectic transformation temperature, only one equation was used. NEM results were compared and verified with experimental results, empirical and software calculations. The created application is a simple, low-cost and reliable mean for calculating TL, TP, and TS. The main contribution of the thesis is the acquisition of original data and the extension of the thermo-physical and thermodynamic properties of steels. The data can be used to optimize casting conditions in the steel casting industry. Furthermore, the data can be used as input data for modelling software that allows modelling of casting processes of steels and following solidification (Magmasoft, Procast) or to modify thermodynamic software databases. Acquired new knowledge can contribute to the development of metallurgy, foundry and material engineering, thermal analysis methods and physical-numerical modelling. As a result, it will enable the optimization of steel casting and solidification processes where the goal is to obtain a better and less expensive product.619 - Katedra fyzikální chemie a teorie technologických pochodůvyhově

Production and Economic Parameters of a Poplar (J 105) Coppice Plantation with Different Length of the First Rotation in the Conditions of the Bohemian-Moravian Highlands

The paper analysed production and economic effectiveness of a short-rotation coppice plantation, namely J 105, after the first rotation period of 7 and 8 years respectively. The plantation is located in the region of the Bohemian-Moravian Highlands with an annual precipitation of 497 mm and mean air temperature of 8.6 °C. To assess the productivity, the trees were selected according to stem diameter at a height of 10 cm above the ground level and classified into three categories: I) 0–3.0 cm; II) 3.1–7.0 cm and III) > 7.0 cm. Sample trees were selected in each year. The economic effectiveness of the plantation was assessed as the difference between profits and costs for both rotation cycles. The mean annual above-ground biomass production for the 7-year rotation (2012) was 3.15 t/ha and 3.30 t/ha for the 8-year rotation (2013). The low productivity of poplar was due to slow growth (approx. 0.5 m in height) and drought in the first year after the plantation was established. The economic effectiveness for the 7-year rotation was CZK −5,300/ha and CZK +17,500/ha for the 8-year rotation. It was due to current total aboveground dry mass increment in the 8th year of rotation

Comparability of semivolatile organic compound concentrations from co-located active and passive air monitoring networks in Europe

Passive air sampling (PAS) has been used to monitor semivolatile organic compounds (SVOCs) for the past 20 years, but limitations and uncertainties persist in the derivation of effective sampling volumes, sampling rates, and concentrations. As a result, the comparability of atmospheric levels measured by PAS and concentrations measured by active air sampling (AAS) remains unclear. Long-term PAS data, without conversion into concentrations, provide temporal trends that are similar to, and consistent with, trends from AAS data. However, for more comprehensive environmental and human health assessments of SVOCs, it is also essential to harmonize and pool air concentration data from the major AAS and PAS monitoring networks in Europe. To address this need, we calculated and compared concentration data for 28 SVOCs (including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs)) at the six monitoring sites in Europe with 10 years of co-located AAS (EMEP) and PAS (MONET) data: Birkenes, Kosetice, Pallas, Rao, Storhofoi, and Zeppelin. Atmospheric SVOC concentrations were derived from PAS data using the two most common computation models. Long-term agreement between the AAS and PAS data was strong for most SVOCs and sites, with 79% of the median PAS-derived concentrations falling within a factor of 3 of their corresponding AAS concentrations. However, in both models it is necessary to set a sampler-dependent correction factor to prevent underestimation of concentrations for primarily particle-associated SVOCs. In contrast, the models overestimate concentrations at sites with wind speeds that consistently exceed 4 m s(-1). We present two recommendations that, if followed, allow MONET PAS to provide sufficiently accurate estimates of SVOC concentrations in air so that they can be deployed together with AAS in regional and global monitoring networks.ISSN:2050-7887ISSN:2050-789

Study of phase transformation temperatures of alloys based on Fe-C-Cr in high-temperature area

Three alloys based on Fe-C-Cr were studied. These alloys contained carbon in a range of 0.308-0.380 mass% and chromium 1.058-4.990 mass%. Temperatures of solidus (onward used as T (S)), liquidus (onward used as T (L)) and peritectic transformation (onward used as T (P)) were studied in the high-temperature region. These temperatures were obtained using two thermal analysis methods: differential thermal analysis (onward used as DTA) and simple thermal analysis (onward used as TA). The Setaram Setsys 18(TM) was used for experiments with employment of the DTA method. All measurements were taken in an inert atmosphere of pure argon at heating rate of 10 A degrees C min(-1), and simple TA method was used for the experiments with the use of the Netzsch STA 449 F3 Jupiter. Measurements were taken in inert atmosphere of pure argon at a heating and cooling rate of 5 A degrees C min(-1). Phase transformation temperatures were obtained by heating and cooling process and were approximated to "equilibrium conditions" (DTA method: zero heating rate and sample mass, standard, TA method: only standard) (A 1/2 aludova et al. in J Therm Anal Calorim 112:465-471, 2013a. The experimental data were compared and discussed with the calculation results using IDS (solidification analysis package) software (onward used as SW) Thermo-Calc and the TCFE8 (Thermo-Calc Fe-based alloys) database. The results of the two alloys were compared with those published for similar steels. The experimentally obtained transition temperatures were close to the calculated values. The solidus, liquidus and peritectic transformation temperatures were lowered with increasing carbon (range 0.308-0.380 mass%) and chromium content (range 1.058-4.990 mass%). The smallest difference between the experimental results and theoretical calculations was observed at the liquidus temperature for all alloys. Nonetheless, the difference measured for the solidus temperatures was much greater.Web of Science1331484

Experimental and theoretical assessment of liquidus, peritectic transformation, and solidus temperatures of laboratory and commercial steel grades

The paper deals with theoretical and experimental study of phase transformation temperatures of steels in high temperature region (above 1000 degrees C), with focus on the solidus temperature, peritectic transformation temperature and liquidus temperature of multicomponent steels. Experimental data were obtained using Differential Thermal Analysis and direct thermal analysis. The experimental data were assessed by basic statistics. The calculations were performed using InterDendritic Solidification software and Thermo-Calc software. Also, selected empirically based models were used for calculations. The study presents the basic principles of theoretical and experimental methods, characteristics, advantages and disadvantages. Both used thermo-analytical methods are set correctly; the results are reproducible, comparable and close to equilibrium temperatures. Furthermore, comprehensive comparisons between the calculated and measured phase transformation temperatures show that the experimental data is satisfactorily accounted for by the present thermodynamic description.Web of Science4011039

Prediction and measurement of selected phase transformation temperatures of steels

The study deals with precise determination of phase transformation temperatures of steel. A series of experimental measurements were carried out by Differential Thermal Analysis (DTA) and Direct Thermal Analysis (TA) to obtain temperatures very close to the equilibrium temperatures. There are presented results from the high temperatures region, above 1000 degrees C, with focus on the solidus temperatures (T-S), peritectic transition (T-P) and liquidus (T-L) of multicomponent steels. The data obtained were verified by statistical evaluation and compared with computational thermodynamic and empirical calculations. The calculations were performed using 15 empirical equations obtained by literature research (10 for T-L and 5 for T-S), as well as by software InterDendritic Solidification (IDS) and Thermo-Calc (2015b, TCFE8; TC). It was verified that both thermo-analytical methods used are set correctly; the results are reproducible, comparable and close to equilibrium state.Web of Science53339839

A comprehensive assessment of endocrine-disrupting chemicals in an Indian food basket: Levels, dietary intakes, and comparison with European data

Endocrine-disrupting chemicals (EDCs) in diet are a health concern and their monitoring in food has been introduced in the European Union. In developing countries, EDC dietary exposure data are scarce, especially from areas perceived as pollution hotspots, including industrialized countries like India. Several persistent organic pollutants (POPs) act as EDCs and pose a pressure to human health mainly through dietary exposure. In the present study a range of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dioxins and furans were measured in several food items collected in an Indian urban (Delhi) and a rural area (Dehradun). Food basket contamination data were used to estimate dietary exposure and compare it with that of the average European population estimated from available monitoring data. All targeted contaminants were found in most food items, especially in dairies and meat products. OCPs were the main contributors. Food supplied to Delhi's markets had higher contamination than that supplied to the peri-urban market in Dehradun. Despite looser control and restrictions, Indian dietary exposure of OCPs and PBDEs were comparable with that of Europe and were lower for PCBs and dioxins. Higher meat consumption in Europe only partly explained this pattern which was driven also by the higher residues in some European food items. A substantial part of endocrine disrupting potential in the diet derives from food and animal feeds internationally traded between developed and developing countries. With increasingly globalized food systems, internationally harmonized policies on EDC in food can lead to better protection of health in both these contexts