Toxicological analysis of the risk of lead exposure in metal processing

Purpose: To evaluate toxicological risks for workers who are exposed to lead in their work environment. Methods: Since it is an important indicator of toxicological risk, a statistical analysis of lead concentration and biological lead toxicity markers in blood and urine were performed for both exposed and control groups. Both experimental groups consisted of employees from "NISSAL" JSC factory. Analytical epidemiological method in the form of a retrospective cohort study was applied, and covered the period from 2001 to 2010. The concentration of lead, δ-aminolevulinic acid, and coproporphyrin in biological samples were determined by spectrophotometric methods. Results: The results showed a high positive correlation between lead concentrations in blood and urine and the length of exposure of the participants (p < 0.01). Also, increase of lead concentration in the biological material significantly increased δ-aminolevulinic acid (p < 0.01) and slightly increased the concentration of coproporphyrin, both of which are important indicators of toxicological risk. Conclusion: The control group of employees belonged to the normal risk category, while the exposed group belonged to a moderate risk category. Correlation between the monitored parameters is statistically significant at p < 0.01 and p < 0.05. Keywords: Lead, δ-Aminolevulinic acid, Coproporphyrin, Chronic exposure, Toxicity, Correlatio

Butler-volmer current equation and fractal nature correction in electrochemical energy

The Global Energy Crisis necessitated improving research into new, renewable and alternative energy sources. Due to that, our focus is on the area of some phenomena and applications where different synthetic methods and microstructure property optimization achieved significant improvement in the electro physical properties of output materials and components. This is especially important for higher energy efficiency and electricity production (batteries and battery systems, fuel cells, and hydrogen energy). The improvement of energy storage tank capacity is one of the most important development issues in the energy sphere too. It is because of this very promising research and application area that we are expanding the knowledge on these phenomena through fractal nature analysis. So, the results obtained in the field of electrochemical energy sources, especially in electrolyte development, are taken into account the analysis of fractal nature optimization. Based on the research field of fractal material science, particularly electronic materials, we conducted research in micro-structure fractal influence in the area of electrochemistry. We investigated the consolidation parameters of Fe2O3 redox processes. The influence of activation energy, fundamental thermodynamic parameters, and also the fractal correction of electrode surface area through complex fractal dimension with recognized grains and pores, and the Brownian motion of particles is introduced. Finally, the electrochemical Butler-Volmer equation fractalization is obtained. These results practically open new frontiers in electrochemical energy processes performed through the Arrhenius equation within electrolyte bulk and electrode relations and more complete and precise energy generation

Geochemistry of the hydrothermal dickite (nowa ruda, lower silesia, poland): chromium

Geochemical analyses for trace Cr have been made on a representative sample of a typical hydrothermal dickite filling vein at Nowa Ruda. The mineralogy of the sample is comparatively simple, dickite being the principal component (ca. 91% of total sample). Geochemical fractionation and inductively coupled plasma-optical emission spectrometry (ICP-OES) indicate that most (>96 % of total metal) of Cr reside in the dickite. The combination of geochemical and spectroscopic tools applied on Cr3+ allow one to specify the Eh (>0.4 V, highly oxidizing) and pH (≤4.0, highly acidic) of the solution during the formation of dickite from the Nowa Ruda Basin. We suggest that hot hydrothermal waters leached the surrounding varieties of gabbroids enriched in Cr for the dickite-forming solution

Application of oxidation processes in the purification of wastewaters from phenolic compounds

Natural phenolic compounds are significant component of the human diet, as they are present in fruits and vegetables, and they have very important biological activity in the living organisms. Because of their structure, they are subject of numerous oxidation processes, such as autoxidation, but are easily to oxidize in presence of various oxidizing agents and enzymes. Many authors have been investigating phenolic oxidation processes, and have successfully identified their pathways and a significant number of intermediates and products generated by these processes. Also, particular attention has been made to the effects of these processes on food quality and other biological processes in living organisms. Phenols are persistent pollutants of water systems from various agricultural activities and industrial wastewater discharges. It is known that the presence of phenolic compounds in water supplies and industrial effluents directly affects natural processes in the environment due to their toxicity and natural ability to decompose. This property, to easily oxidize and, as a result of it, to mineralize, is practically useful for the treatment of the wastewaters, so it is of global concern to manage the best technology to remove phenols and other organic pollutants, assisted with the oxidation processes. In the aspect of treatment of wastewaters polluted with phenols, we reviewed oxidative processes such as autoxidation, enzyme-catalyzed oxidation, photo-oxidation, electrochemical oxidation and oxidation by Fenton's reagent and, based on the literature data, we presented advantages and disadvantages of these processes compared to each other. © 2020 Editura Academiei Romane. All rights reserved

Chemical Analysis of Mortars of Archeological Samples form Mediana

The aim of this study was mineralogical and chemical analysis of mortar from the floor, ceiling and wall of Stibadium B, from the archaeological site of Mediana. ICP-OES and FTIR-spectroscopy were used to determine chemical composition and some major mineralogical species. The obtained results show that lime mortar is probably used. Large contribution of silicon- and aluminum-oxides, indicate the presence of quartz and clay minerals derived from the aggregate, river sand and crushed bricks. The obtained results also show large amount of iron, manganese and copper. The determinated metals in samples from floor and wall of Stibadium B, are mostly present in oxide fraction, while in sample from ceiling, they are mostly found in silicate fraction

Chemical Analysis of Mortars of Archeological Samples form Mediana

The aim of this study was mineralogical and chemical analysis of mortar from the floor, ceiling and wall of Stibadium B, from the archaeological site of Mediana. ICP-OES and FTIR-spectroscopy were used to determine chemical composition and some major mineralogical species. The obtained results show that lime mortar is probably used. Large contribution of silicon- and aluminum-oxides, indicate the presence of quartz and clay minerals derived from the aggregate, river sand and crushed bricks. The obtained results also show large amount of iron, manganese and copper. The determinated metals in samples from floor and wall of Stibadium B, are mostly present in oxide fraction, while in sample from ceiling, they are mostly found in silicate fraction

Measurement of the production cross section of prompt j/psi mesons in association with a W (+/-) boson in pp collisions root s=7 TeV with the ATLAS detector

The process pp - GT W (+/-) J/psi provides a powerful probe of the production mechanism of charmonium in hadronic collisions, and is also sensitive to multiple parton interactions in the colliding protons. Using the 2011 ATLAS dataset of 4.5 fb(-1) of root s= 7 TeV pp collisions at the LHC, the first observation is made of the production of W (+/-) + prompt J/psi events in hadronic collisions, using W (+/-) - GT mu nu(mu) and J/psi - GT mu(+)mu(-) center dot A yield of W (+/-) + prompt J/psi events is observed, with a statistical significance of 5.1 sigma. The production rate as a ratio to the inclusive W (+/-) boson production rate is measured, and the double parton scattering contribution to the cross section is estimated

Search for W - GT t(b)over-bar in the lepton plus jets final state in proton-proton collisions at a centre-of-mass energy of root s=8 TeV with the ATLAS detector

A search for new charged massive gauge bosons, called W, is performed with the ATLAS detector at the LHC, in proton-proton collisions at a centre-of-mass energy of root s = 8 TeV, using a dataset corresponding to an integrated luminosity of 20.3 fb(-1). This analysis searches for W bosons in the W - GT t (b) over tilde decay channel in final states with electrons or muons, using a multivariate method based on boosted decision trees. The search covers masses between 0.5 and 3.0 TeV, for right-handed or left-handed W bosons. No significant deviation from the Standard Model expectation is observed and limits are set on the W - GT t (b) over bar cross-section times branching ratio and on the W-boson effective couplings as a function of the W-boson mass using the CLs procedure. For a left-handed (right-handed) W boson, masses below 1.70 (1.92) TeV are excluded at 95% confidence level. Published by Elsevier B.V

Search for dark matter in events with heavy quarks and missing transverse momentum in pp collisions with the ATLAS detector

This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb(-1) of pp collisions collected at root s = 8 TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing b-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter-nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a coloured mediator suitable to explain a possible signal of annihilating dark matter

Search for new phenomena in events with a photon and missing transverse momentum in pp collisions at root s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum with the ATLAS experiment at the LHC are reported. Data were collected in proton-proton collisions at a center-of-mass energy of 8 TeVand correspond to an integrated luminosity of 20.3 fb(-1). The observed data are well described by the expected Standard Model backgrounds. The expected (observed) upper limit on the fiducial cross section for the production of events with a photon and large missing transverse momentum is 6.1 (5.3) fb at 95% confidence level. Exclusion limits are presented on models of new phenomena with large extra spatial dimensions, supersymmetric quarks, and direct pair production of dark-matter candidates