ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT Direct activity determination by a flow-through microcalorimetry in the enzyme thermisto... more ABSTRACT Direct activity determination by a flow-through microcalorimetry in the enzyme thermistor system was employed for a fast comparison of (poly)acrylamide gel-entrapped penicillin G acylase preparations. Composition of the pre-polymerization cocktail and both the storage and operational stabilities of optimal gel-entrapped enzyme preparations isolated from the Escherichia coli industrial strain were optimized by this method. The validity of the results was corroborated by spectrophotometric measurements.
Three new metabolites - (-)-mitorubrinol, 2-formyl-3,5-dihydroxy-4-methylbenzoic and 2-formyl-3,5... more Three new metabolites - (-)-mitorubrinol, 2-formyl-3,5-dihydroxy-4-methylbenzoic and 2-formyl-3,5-dihydroxy-4-hydroxymethylbenzoic acids - were isolated from the culture medium of Penicillium vermiculatum DANG. Hexane extract of the mycelium contained ergosterol and esters of fatty acids, linoleic, oleic and palmitic acids being the dominating ones.
Although harvestmen (Opiliones) are among the best studied groups of arachnids in Europe from the... more Although harvestmen (Opiliones) are among the best studied groups of arachnids in Europe from the faunistic point of view, there is still lack of available information on ecological requirements of the particular species. Habitat preferences that determine the distribution of species are largely determined by the habitat structure and microclimate. Besides other factors, these characteristics of habitats are also influenced by the nature of the vegetation. Therefore, our study dealt with the influence of tree species on harvestmen communities. We conducted the research on nine sites in the Borová hora arboretum (Zvolen town, Central Slovakia). Each studied site represents a monoculture of one of nine tree species. On each site also some attributes of soil and leaf litter (pH, conductivity, content of H, C, N and P) were evaluated. Harvestmen were collected by pitfall trapping during vegetation periods in 2008–2012. In total, 2515 individuals of 17 species and 3 families were obtaine...
Extraction of coal, gold, and polymetallic ore, as well as their modifications, has left a lot of... more Extraction of coal, gold, and polymetallic ore, as well as their modifications, has left a lot of dumps of waste material, tailings, and abandoned mines in the world. Sulphide minerals in these deposits under aerobic conditions (air and water) are liable to microbio-chemical biodegradation by litotrophic bacteria and archaea, resulting in acid mine drainage (AMD) production. Processes caused by litotrophic microorganisms, namely Acidithiobacillus sp. and Leptospirillum sp, have occurred in the soil dump of pyritized hydroquartzite in the area of Banska Stiavnica – Sobov. They bring about AMD production, with dominant components of Fe, Al, and sulphates. This article deals with active modification/treatment (gaining of Fe-sorbents, Fe-pigments) and remediation (decreasing concentration of contaminants – heavy metal, sulphate) of AMD from this area. The products of various purities, phase compositions, and properties, including surface properties, can be synthesized from AMD depending on the reaction conditions. Obtained Fe-oxyhydroxides can be transformed thermally to hematite structure (basic ferric pigment). The other method of utilizing of Fe-sludge is the creation of ferrites (general structure MFe2O4 (M – Me +2 ), e. g. zinc ferrite. In an application of alkaline industrial effluents, especially red mud bauxite and blast furnace slag, in batch experiment and neutralization of AMD, it has been shown that it is possible to reduce contents of Fe, Al, Cu, Zn, Mn, and sulphates with these agents.
Preliminary results of research focused on the utilisation of specific waste from metallurgical a... more Preliminary results of research focused on the utilisation of specific waste from metallurgical and mining activities to obtain ferrite pigments are presented. As a source of iron in the spinel-type ferrites with the general structure MFe2O4 (where M is a bivalent metal such as Ca and Zn), three types of industrial wastes were used: metallurgical slag from the production of non-ferrous metals and two types of AMD (acid mine drainage) sludge: one of natural origin (Fe-sediment) and the second one synthetically prepared from AMD (Fe-precipitate). This waste was homogenised by ZnO and CaCO3 in various stoichiometric ratios n(Ca): n(Zn): n(Fe) and calcined at the temperature of 1000–1095°C. Mineralogical (XRD) analysis of the metallurgical slag pigments confirmed the formation of zinc ferrite and hematite only (Ca from reaction components entered into other phases). The ferric component of the AMD sludge (Fe-precipitate and Fe-sediment) formed a mixture of zinc ferrite, calcium ferrite,...
Vysokoškolská učebnica sa zaoberá problémami znečisťovania ako dôsledok priemyselnej aktivity, al... more Vysokoškolská učebnica sa zaoberá problémami znečisťovania ako dôsledok priemyselnej aktivity, ale aj otázkami znižovania emisií, sanácie kontaminovaných území a využívania najlepších dostupných techník (BAT). Problematika skúmania environmentálnych aspektov má široké interdisciplinárne súvislosti a vyžaduje dokonalú spoluprácu celého radu odborníkov. Cieľom učebnice je pripraviť absolventov vysokoškolského štúdia na tímovú spoluprácu a oboznámiť ich s najnovšími legislatívnymi podmienkami týkajúcimi sa posudzovania vplyvov na životné prostredie a na zdravie obyvateľstva. V úvodných kapitolách sú rozoberané všeobecné aspekty environmentálnych vplyvov priemyselných činností (legislatíva, definície základných pojmov, vzťahov a vzájomných súvislostí, rozdelenie technológií, spôsoby znižovania emisií a pod.). Učebnica je ďalej členená na kapitoly zamerané na výrobu a analýzu vybraných príkladov základných priemyselných látok ako z oblasti anorganickej, tak aj organickej technológie a te...
The study describes a new way of treating of acid mine drainage (AMD) waters containing sulphate ... more The study describes a new way of treating of acid mine drainage (AMD) waters containing sulphate of Fe+3 and Al+3 as dominant components using homogenous thermal hydrolysis with urea. The model solution and the acid mine drainage solution were kept with urea at one of the selected temperatures (60°C, 80°C and 95°C) in thermostatic bath. X-ray powder diffraction spectra identified four main phases in the hydrolysis products, namely: goethite, schwertmannite, ferrihydrite and jarosite. No crystalline phases of aluminum were detected. Depending on the precipitation conditions, the prepared samples consist of spherical aggregates of nanocrystals of various modifications of hydrated iron oxides. The specific surface area results show that with increasing content of Al3+, the specific surface area in the final product decreases. The results reveal that by homogenous hydrolysis of acid mine drainage with urea, it is possible to prepare easily filterable relatively pure oxide precipitates w...
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT Direct activity determination by a flow-through microcalorimetry in the enzyme thermisto... more ABSTRACT Direct activity determination by a flow-through microcalorimetry in the enzyme thermistor system was employed for a fast comparison of (poly)acrylamide gel-entrapped penicillin G acylase preparations. Composition of the pre-polymerization cocktail and both the storage and operational stabilities of optimal gel-entrapped enzyme preparations isolated from the Escherichia coli industrial strain were optimized by this method. The validity of the results was corroborated by spectrophotometric measurements.
Three new metabolites - (-)-mitorubrinol, 2-formyl-3,5-dihydroxy-4-methylbenzoic and 2-formyl-3,5... more Three new metabolites - (-)-mitorubrinol, 2-formyl-3,5-dihydroxy-4-methylbenzoic and 2-formyl-3,5-dihydroxy-4-hydroxymethylbenzoic acids - were isolated from the culture medium of Penicillium vermiculatum DANG. Hexane extract of the mycelium contained ergosterol and esters of fatty acids, linoleic, oleic and palmitic acids being the dominating ones.
Although harvestmen (Opiliones) are among the best studied groups of arachnids in Europe from the... more Although harvestmen (Opiliones) are among the best studied groups of arachnids in Europe from the faunistic point of view, there is still lack of available information on ecological requirements of the particular species. Habitat preferences that determine the distribution of species are largely determined by the habitat structure and microclimate. Besides other factors, these characteristics of habitats are also influenced by the nature of the vegetation. Therefore, our study dealt with the influence of tree species on harvestmen communities. We conducted the research on nine sites in the Borová hora arboretum (Zvolen town, Central Slovakia). Each studied site represents a monoculture of one of nine tree species. On each site also some attributes of soil and leaf litter (pH, conductivity, content of H, C, N and P) were evaluated. Harvestmen were collected by pitfall trapping during vegetation periods in 2008–2012. In total, 2515 individuals of 17 species and 3 families were obtaine...
Extraction of coal, gold, and polymetallic ore, as well as their modifications, has left a lot of... more Extraction of coal, gold, and polymetallic ore, as well as their modifications, has left a lot of dumps of waste material, tailings, and abandoned mines in the world. Sulphide minerals in these deposits under aerobic conditions (air and water) are liable to microbio-chemical biodegradation by litotrophic bacteria and archaea, resulting in acid mine drainage (AMD) production. Processes caused by litotrophic microorganisms, namely Acidithiobacillus sp. and Leptospirillum sp, have occurred in the soil dump of pyritized hydroquartzite in the area of Banska Stiavnica – Sobov. They bring about AMD production, with dominant components of Fe, Al, and sulphates. This article deals with active modification/treatment (gaining of Fe-sorbents, Fe-pigments) and remediation (decreasing concentration of contaminants – heavy metal, sulphate) of AMD from this area. The products of various purities, phase compositions, and properties, including surface properties, can be synthesized from AMD depending on the reaction conditions. Obtained Fe-oxyhydroxides can be transformed thermally to hematite structure (basic ferric pigment). The other method of utilizing of Fe-sludge is the creation of ferrites (general structure MFe2O4 (M – Me +2 ), e. g. zinc ferrite. In an application of alkaline industrial effluents, especially red mud bauxite and blast furnace slag, in batch experiment and neutralization of AMD, it has been shown that it is possible to reduce contents of Fe, Al, Cu, Zn, Mn, and sulphates with these agents.
Preliminary results of research focused on the utilisation of specific waste from metallurgical a... more Preliminary results of research focused on the utilisation of specific waste from metallurgical and mining activities to obtain ferrite pigments are presented. As a source of iron in the spinel-type ferrites with the general structure MFe2O4 (where M is a bivalent metal such as Ca and Zn), three types of industrial wastes were used: metallurgical slag from the production of non-ferrous metals and two types of AMD (acid mine drainage) sludge: one of natural origin (Fe-sediment) and the second one synthetically prepared from AMD (Fe-precipitate). This waste was homogenised by ZnO and CaCO3 in various stoichiometric ratios n(Ca): n(Zn): n(Fe) and calcined at the temperature of 1000–1095°C. Mineralogical (XRD) analysis of the metallurgical slag pigments confirmed the formation of zinc ferrite and hematite only (Ca from reaction components entered into other phases). The ferric component of the AMD sludge (Fe-precipitate and Fe-sediment) formed a mixture of zinc ferrite, calcium ferrite,...
Vysokoškolská učebnica sa zaoberá problémami znečisťovania ako dôsledok priemyselnej aktivity, al... more Vysokoškolská učebnica sa zaoberá problémami znečisťovania ako dôsledok priemyselnej aktivity, ale aj otázkami znižovania emisií, sanácie kontaminovaných území a využívania najlepších dostupných techník (BAT). Problematika skúmania environmentálnych aspektov má široké interdisciplinárne súvislosti a vyžaduje dokonalú spoluprácu celého radu odborníkov. Cieľom učebnice je pripraviť absolventov vysokoškolského štúdia na tímovú spoluprácu a oboznámiť ich s najnovšími legislatívnymi podmienkami týkajúcimi sa posudzovania vplyvov na životné prostredie a na zdravie obyvateľstva. V úvodných kapitolách sú rozoberané všeobecné aspekty environmentálnych vplyvov priemyselných činností (legislatíva, definície základných pojmov, vzťahov a vzájomných súvislostí, rozdelenie technológií, spôsoby znižovania emisií a pod.). Učebnica je ďalej členená na kapitoly zamerané na výrobu a analýzu vybraných príkladov základných priemyselných látok ako z oblasti anorganickej, tak aj organickej technológie a te...
The study describes a new way of treating of acid mine drainage (AMD) waters containing sulphate ... more The study describes a new way of treating of acid mine drainage (AMD) waters containing sulphate of Fe+3 and Al+3 as dominant components using homogenous thermal hydrolysis with urea. The model solution and the acid mine drainage solution were kept with urea at one of the selected temperatures (60°C, 80°C and 95°C) in thermostatic bath. X-ray powder diffraction spectra identified four main phases in the hydrolysis products, namely: goethite, schwertmannite, ferrihydrite and jarosite. No crystalline phases of aluminum were detected. Depending on the precipitation conditions, the prepared samples consist of spherical aggregates of nanocrystals of various modifications of hydrated iron oxides. The specific surface area results show that with increasing content of Al3+, the specific surface area in the final product decreases. The results reveal that by homogenous hydrolysis of acid mine drainage with urea, it is possible to prepare easily filterable relatively pure oxide precipitates w...
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