About the possibility of sorption concentration of heavy metals using magnetite

This paper addresses the possibility of using magnetite nanoparticles for sorption concentration of heavy metals ions in the analysis of their trace amounts. On the example of copper, lead and nickel ions, optimum conditions for concentrating have been determined, pH, temperature and contact time effect on the adsorption process have been studied in the static mode, and magnetite sorption capacity has been calculated on the basis of experimental data

Results of AAS measurements of atmospheric trace metals deposition in snow cover in lower kama urban agglomeration

The study of pollutant level of snow cover of the explored territory required establishment of more than 80 sample plots within the territory of several hundreds square kilometers including industrial area of Naberezhnye Chelny (steam power plants, JSC KAMAZ plants, etc.), which are exposed to intense human impact of the area of agroindustrial complex of the Tukai district, the part of "Lower Kama" national park area, and the territory of the city of Naberezhnye Chelny as well. Within the framework of the study snow sampling was carried out within these sample plots, its main features and contaminators' weight content were defined. Moreover, the results of long-term observations over snow cover state of the territory of the Naberezhnye Chelny (Lower Kama) urban agglomeration that allow - taking into account synoptic conditions by the end of cold period - forecasting the beginning of intense snow melting and planning snow-measuring measures and sampling correspondingly. To assess impact on environment, accumulated with snow and soil cover of pollutants, their inflow per unit area and per explored territory was estimated. Obtained results allowed to asses the snow cover contamination level by several complex indicators. The snow cover contamination level based on this data should be recognized as quite considerable: median value of contamination total index Kp5 is 15,1 that allow us to relate this territory to heavily polluted. Whereby partial coefficients of contamination with cooper and zinc, and manganese iron and nickel to a somewhat less degree, make a major contribution to this index

Sorption concentration of arsenic ions by magnetite

© The author(s). This paper is focused on the possibility of using magnetite powders obtained by chemical and plasma-chemical method for sorption concentration of arsenic ions. Processes of arsenic concentration by two-site sorption in magnetite-water system have been studied, and the optimal conditions for concentration have been defined. In static mode, effects of pH, temperature and contact time on the adsorption process have been studied. As a result, a method for pre-sorption concentration has been proposed, allowing reducing the lower limit of the atomic absorption determination of arsenic content

The influence of ash tree sawdust acid treatment on the removal of crude oil from water surfaces

Agricultural and timber industry wastes may constitute a significant source of promising oil sorption materials. In this study the potential application of Fráxinus excélsior ash tree sawdust as sorption material for crude oil removal was investigated. The effect of acid treatment on physicochemical and sorption properties of sawdust was studied in a batch system. Oil sorption capacity and water uptake of sorption materials in static system were evaluated. For the determination of raw and treated samples structure and surface changes X-ray diffraction analysis, atomic force microscopy, FTIR spectroscopy and contact angle evaluation were used. The highest oil sorption capacity was shown by 3% HNO3 treated sawdust, 43.2% and 37.4% increase of oil sorption capacity for Devonian oil and Carbon oil, respectively, was observed in comparison with untreated sawdust. The exhibited reduction of modified sawdust water uptake indicated the increase of sorbent material hydrophobicity that was confirmed by the results of contact angle determination. Based on atomic force microscopy results, the surface roughness of treated sawdust was shown to be enhanced that could be a primary factor affecting on oil sorption capacity improvement. Thus, acid treated ash tree sawdust was shown to have improved oil sorption and physicochemical characteristics for crude oil removal

The histochemistry of thiols and disulphides. II. Methodology of differential staining

The reduction of disulphide bonds by various mercaptans and tri- n -butylphosphine (TBP) has been examined in paraffin sections of rat tissues. A ‘re-reduction’ procedure demonstrating any residual disulphides shows that nearly equivalent endpoints are reached by all of the reagents at pH 8.5 and room temperature, though at greatly differing rates. TBP is the reductant of choice in that it acts rapidly, cannot cause the thiolation which is more or less pronounced with certain mercaptans and least reverses the prior alkylation of native thiol groups by iodoacetate or N-substituted malemides. Supporting studies establish that, except in highly compact structures, native as well as generated thiol groups can be visualized with satisfactory completeness and specificity by N-(4-aminophenyl)maleimide followed by a diazotization and coupling sequence. These findings provide the basis for the selective staining of disulphides, either alone or differentiated from native thiols in the same section.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42844/1/10735_2005_Article_BF01003139.pd

Plane torsion waves in quadratic gravitational theories

The definition of the Riemann-Cartan space of the plane wave type is given. The condition under which the torsion plane waves exist is found. It is expressed in the form of the restriction imposed on the coupling constants of the 10-parametric quadratic gravitational Lagrangian. In the mathematical appendix the formula for commutator of the variation operator and Hodge operator is proved. This formula is applied for the variational procedure when the gravitational field equations are obtained in terms of the exterior differential forms.Comment: 3 May 1998. - 11

Severe thrombocytosis and anemia associated with celiac disease in a young female patient: a case report

<p>Abstract</p> <p>Introduction</p> <p>Platelet counts exceeding 1.000 × 10³/μl are usually considered secondary to another cause, particularly to chronic myeloproliferative disease (CMPD). Reactive thrombocytosis due to iron deficiency rarely exceeds platelet counts of 700 × 10³/μl.</p> <p>Case presentation</p> <p>Here we report the case of a young woman presenting with clinical signs of severe anemia. Laboratory findings confirmed an iron-deficiency anemia associated with severe thrombocytosis of 1703 × 10³/μl. Macroscopic gastrointestinal and genitourinary tract bleeding was excluded. The excessive elevation of platelets, slightly elevated lactate dehydrogenase and slightly elevated leukocytes along with the absence of other inflammation parameters raised the suspicion of an underlying hematological disease. However, bone marrow evaluation could not prove the suspected diagnosis of a CMPD, especially essential thrombocythemia (ET). In the further clinical course the platelet count returned to normal after raising the hemoglobin to a level close to normal range with erythrocyte transfusion, and normalization of serum iron and decline of erythropoietin. Finally, following small bowel biopsy, despite the absence of typical clinical signs, celiac disease was diagnosed. After discharge from hospital the patient was commenced on a gluten-free diet and her hemoglobin almost completely normalized in the further follow-up period.</p> <p>Conclusion</p> <p>This case illustrates the rare constellation of an extreme thrombocytosis most likely secondary to iron deficiency due to celiac disease. This represents, to the best of the authors' knowledge, the highest reported platelet count coincident with iron deficiency. A potential mechanism for the association of iron-deficiency anemia and thrombocytosis is discussed. Even in the presence of 'atypically' high platelets one should consider the possibility of reactive thrombocytosis. Extreme thrombocytosis could emerge in the case of iron deficiency secondary to celiac disease.</p

Ground cover rice production system facilitates soil carbon and nitrogen stocks at regional scale

Rice production is increasingly limited by water scarcity. Covering paddy rice soils with films (so-called ground cover rice production system: GCRPS) can significantly reduce water demand as well as overcome temperature limitations at the beginning of the growing season, which results in greater grain yields in relatively cold regions and also in those suffering from seasonal water shortages. However, it has been speculated that both increased soil aeration and temperature under GCRPS result in lower soil organic carbon and nitrogen stocks. Here we report on a regional-scale experiment conducted in Shiyan, a typical rice-producing mountainous area of China. We sampled paired adjacent paddy and GCRPS fields at 49 representative sites. Measured parameters included soil carbon (C) and nitrogen (N) stocks (to 1m depth), soil physical and chemical properties, δ$^{15}$N composition of plants and soils, potential C mineralization rates, and soil organic carbon (SOC) fractions at all sampling sites. Root biomass was also quantified at one intensively monitored site. The study showed that: (1) GCRPS increased SOC and N stocks 5–20 years following conversion from traditional paddy systems; (2) there were no differences between GCRPS and paddy systems in soil physical and chemical properties for the various soil depths, with the exception of soil bulk density; (3) GCRPS increased above-ground and root biomass in all soil layers down to a 40 cm depth; (4) δ$^{15}$N values were lower in soils and plant leaves indicating lower NH$_{3}$ volatilization losses from GCRPS than in paddy systems; and (5) GCRPS had lower C mineralization potential than that observed in paddy systems over a 200-day incubation period. Our results suggest that GCRPS is an innovative production technique that not only increases rice yields using less irrigation water, but that it also increases SOC and N stocks

Pd Nanoparticles and Thin Films for Room Temperature Hydrogen Sensor

We report the application of palladium nanoparticles and thin films for hydrogen sensor. Electrochemically grown palladium particles with spherical shapes deposited on Si substrate and sputter deposited Pd thin films were used to detect hydrogen at room temperature. Grain size dependence of H2sensing behavior has been discussed for both types of Pd films. The electrochemically grown Pd nanoparticles were observed to show better hydrogen sensing response than the sputtered palladium thin films. The demonstration of size dependent room temperature H2sensing paves the ways to fabricate the room temperature metallic and metal–metal oxide semiconductor sensor by tuning the size of metal catalyst in mixed systems. H2sensing by the Pd nanostructures is attributed to the chemical and electronic sensitization mechanisms