Pub Date : 2014-04-09DOI: 10.2478/s11532-014-0553-z
L. Muresan, A. Cadiș, I. Perhaita, E. Indrea
AbstractYttrium silicate doped with cerium (Y2SiO5:Ce) was obtained from Y-Ce-Si based precursors prepared by the simultaneous addition of reagents (SimAdd) technique. The synthesis of the precursors was done in well controlled conditions using ammonium oxalate, ammonium carbonate or urea as precipitating agents. Results regarding the influence of precipitating agents on the morpho structural and photoluminescent characteristics of Y2SiO5:Ce are reported. The TG analysis in correlation with EGA, FT-IR and XRD investigations reveals the formation of oxalate, hydroxy-carbonate or hydroxy-nitrate based compounds, the same as the conversion of the precursors to well crystallized yttrium silicate. XRD patterns show that the precursors are amorphous except for the sample prepared with ammonium oxalate. Depending on the precipitation conditions, the phosphors phase composition varies from single phase (X2-Y2SiO5) to a mixture of phases (X2-Y2SiO5, X1-Y2SiO5, Y2O3). Under UV excitation, phosphors exhibit the specific blue emission of cerium with an intensity that varies from 175.8% (urea) to 96.0% (ammonium carbonate) and to 78.5% (ammonium oxalate). The emission intensity depends on the phase purity and order degree of the phosphors. PACS Classification codes:78.55 Hx, 81.20Fw
{"title":"Morpho-structural and luminescence investigations on yttrium silicate based phosphors prepared with different precipitating agents","authors":"L. Muresan, A. Cadiș, I. Perhaita, E. Indrea","doi":"10.2478/s11532-014-0553-z","DOIUrl":"https://doi.org/10.2478/s11532-014-0553-z","url":null,"abstract":"AbstractYttrium silicate doped with cerium (Y2SiO5:Ce) was obtained from Y-Ce-Si based precursors prepared by the simultaneous addition of reagents (SimAdd) technique. The synthesis of the precursors was done in well controlled conditions using ammonium oxalate, ammonium carbonate or urea as precipitating agents. Results regarding the influence of precipitating agents on the morpho structural and photoluminescent characteristics of Y2SiO5:Ce are reported. The TG analysis in correlation with EGA, FT-IR and XRD investigations reveals the formation of oxalate, hydroxy-carbonate or hydroxy-nitrate based compounds, the same as the conversion of the precursors to well crystallized yttrium silicate. XRD patterns show that the precursors are amorphous except for the sample prepared with ammonium oxalate. Depending on the precipitation conditions, the phosphors phase composition varies from single phase (X2-Y2SiO5) to a mixture of phases (X2-Y2SiO5, X1-Y2SiO5, Y2O3). Under UV excitation, phosphors exhibit the specific blue emission of cerium with an intensity that varies from 175.8% (urea) to 96.0% (ammonium carbonate) and to 78.5% (ammonium oxalate). The emission intensity depends on the phase purity and order degree of the phosphors. PACS Classification codes:78.55 Hx, 81.20Fw\u0000","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"19 1","pages":"1023-1031"},"PeriodicalIF":0.0,"publicationDate":"2014-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78041993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-09DOI: 10.2478/s11532-014-0550-2
R. Summers, Sridhar Gopishetty, S. Mohanty, M. Subramanian
Caffeine is a natural plant product found in many drinks, including coffee, tea, soft and energy drinks. Due to caffeine’s presence in the environment, microorganisms have evolved two different mechanisms to live on caffeine. The genetic maps of the caffeine N-demethylation pathway and C-8 oxidation pathway have been discovered in Pseudomonas putida CBB5 and Pseudomonas sp. CBB1, respectively. These genes are the only characterized bacterial caffeine-degrading genes, and may be of great value in producing fine chemicals, biofuels, and animal feed from coffee and tea waste. Here, we present preliminary results for production of theobromine and 7-methylxanthine from caffeine and theobromine, respectively, by two strains of metabolically engineered E. coli. We also demonstrate complete decaffeination of tea extract by an immobilized mixed culture of Klebsiella and Rhodococcus cells. These processes provide a first level demonstration of biotechnological utilization of coffee and tea waste.
{"title":"New genetic insights to consider coffee waste as feedstock for fuel, feed, and chemicals","authors":"R. Summers, Sridhar Gopishetty, S. Mohanty, M. Subramanian","doi":"10.2478/s11532-014-0550-2","DOIUrl":"https://doi.org/10.2478/s11532-014-0550-2","url":null,"abstract":"Caffeine is a natural plant product found in many drinks, including coffee, tea, soft and energy drinks. Due to caffeine’s presence in the environment, microorganisms have evolved two different mechanisms to live on caffeine. The genetic maps of the caffeine N-demethylation pathway and C-8 oxidation pathway have been discovered in Pseudomonas putida CBB5 and Pseudomonas sp. CBB1, respectively. These genes are the only characterized bacterial caffeine-degrading genes, and may be of great value in producing fine chemicals, biofuels, and animal feed from coffee and tea waste. Here, we present preliminary results for production of theobromine and 7-methylxanthine from caffeine and theobromine, respectively, by two strains of metabolically engineered E. coli. We also demonstrate complete decaffeination of tea extract by an immobilized mixed culture of Klebsiella and Rhodococcus cells. These processes provide a first level demonstration of biotechnological utilization of coffee and tea waste.","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"26 1","pages":"1271-1279"},"PeriodicalIF":0.0,"publicationDate":"2014-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85061492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-09DOI: 10.2478/s11532-014-0547-x
M. Tudorache, George Ghemes, Andreea Nae, E. Matei, I. Mercioniu, E. Kemnitz, Benjamin S. Ritter, S. Coman, V. Pârvulescu
A comparative study of two different biocatalytic models, e.g. enzyme immobilized on magnetic particles (EIMP) and cross-linking enzyme aggregates onto magnetic particles (CLEMPA) was performed. The first model was designed as enzyme-immobilized on the magnetic particles surface (EIMP). The second model was constructed as a network structure with the enzyme aggregates and magnetic particles placed into the nodes and polyglutaraldehyde cross-linker as the network ledges. The design was called cross-linking enzyme aggregates onto magnetic particles (CLEMPA). The biocatalysts were prepared using lipase enzyme from Aspergillus niger for catalyzing the glycerol (Gly) conversion to glycerol carbonate (GlyC). The biocatalyst characteristics for both designs (EIMP and CLEMPA) were evaluated using scanning electron microscopy (SEM), laser light scattering (LLS) and UV-Vis techniques. The EIMP model was strongly influenced by the composition of the polymeric layer covering the particles surface, while the size of the magnetic particles affected mostly the CLEMPA design. Also, the biocatalytic capacity of the tested models was evaluated as maximum 52% Gly conversion with 90% GlyC selectivity for EIMP, and 73% Gly conversion with 77% GlyC selectivity for CLEMPA. Both biocatalytic models were successfully used to prepare GlyC from “crude” glycerol collected directly from the biodiesel process (e.g. 49% Gly conversion with 91% GlyC selectivity for EIMP and 70% Gly conversion with 80% GlyC selectivity for CLEMPA).
{"title":"Biocatalytic designs for the conversion of renewable glycerol into glycerol carbonate as a value-added product","authors":"M. Tudorache, George Ghemes, Andreea Nae, E. Matei, I. Mercioniu, E. Kemnitz, Benjamin S. Ritter, S. Coman, V. Pârvulescu","doi":"10.2478/s11532-014-0547-x","DOIUrl":"https://doi.org/10.2478/s11532-014-0547-x","url":null,"abstract":"A comparative study of two different biocatalytic models, e.g. enzyme immobilized on magnetic particles (EIMP) and cross-linking enzyme aggregates onto magnetic particles (CLEMPA) was performed. The first model was designed as enzyme-immobilized on the magnetic particles surface (EIMP). The second model was constructed as a network structure with the enzyme aggregates and magnetic particles placed into the nodes and polyglutaraldehyde cross-linker as the network ledges. The design was called cross-linking enzyme aggregates onto magnetic particles (CLEMPA). The biocatalysts were prepared using lipase enzyme from Aspergillus niger for catalyzing the glycerol (Gly) conversion to glycerol carbonate (GlyC). The biocatalyst characteristics for both designs (EIMP and CLEMPA) were evaluated using scanning electron microscopy (SEM), laser light scattering (LLS) and UV-Vis techniques. The EIMP model was strongly influenced by the composition of the polymeric layer covering the particles surface, while the size of the magnetic particles affected mostly the CLEMPA design. Also, the biocatalytic capacity of the tested models was evaluated as maximum 52% Gly conversion with 90% GlyC selectivity for EIMP, and 73% Gly conversion with 77% GlyC selectivity for CLEMPA. Both biocatalytic models were successfully used to prepare GlyC from “crude” glycerol collected directly from the biodiesel process (e.g. 49% Gly conversion with 91% GlyC selectivity for EIMP and 70% Gly conversion with 80% GlyC selectivity for CLEMPA).","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"172 1","pages":"1262-1270"},"PeriodicalIF":0.0,"publicationDate":"2014-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77521061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-03DOI: 10.2478/s11532-014-0551-1
Paulina Szatkowska, M. Koba, Piotr Kośliński, Jacek Wandas, T. Bączek
AbstractBenzodiazepines (BDZs) are generally commonly used as anxiolytic and/or hypnotic drugs as a ligand of the GABAA-benzodiazepine receptor. Moreover, some of benzodiazepines are widely used as an anti-depressive and sedative drugs, and also as anti-epileptic drugs and in some cases can be useful as an adjunct treatment in refractory epilepsies or anti-alcoholic therapy. High-performance liquid chromatography (HPLC) methods, thin-layer chromatography (TLC) methods, gas chromatography (GC) methods, capillary electrophoresis (CE) methods and some of spectrophotometric and spectrofluorometric methods were developed and have been extensively applied to the analysis of number of benzodiazepine derivative drugs (BDZs) providing reliable and accurate results. The available chemical methods for the determination of BDZs in biological materials and pharmaceutical formulations are reviewed in this work.
{"title":"Analytical methods for determination of benzodiazepines. A short review","authors":"Paulina Szatkowska, M. Koba, Piotr Kośliński, Jacek Wandas, T. Bączek","doi":"10.2478/s11532-014-0551-1","DOIUrl":"https://doi.org/10.2478/s11532-014-0551-1","url":null,"abstract":"AbstractBenzodiazepines (BDZs) are generally commonly used as anxiolytic and/or hypnotic drugs as a ligand of the GABAA-benzodiazepine receptor. Moreover, some of benzodiazepines are widely used as an anti-depressive and sedative drugs, and also as anti-epileptic drugs and in some cases can be useful as an adjunct treatment in refractory epilepsies or anti-alcoholic therapy. High-performance liquid chromatography (HPLC) methods, thin-layer chromatography (TLC) methods, gas chromatography (GC) methods, capillary electrophoresis (CE) methods and some of spectrophotometric and spectrofluorometric methods were developed and have been extensively applied to the analysis of number of benzodiazepine derivative drugs (BDZs) providing reliable and accurate results. The available chemical methods for the determination of BDZs in biological materials and pharmaceutical formulations are reviewed in this work.\u0000","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"19 1","pages":"994-1007"},"PeriodicalIF":0.0,"publicationDate":"2014-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88006536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-03DOI: 10.2478/s11532-014-0546-y
C. Cannilla, G. Bonura, L. Frusteri, F. Frusteri
In this work the etherification reaction of glycerol with isobutene (IB) and tert-butyl alcohol (TBA) has been studied with the aim of preparing mixtures with high content of poly-substituted ethers. The results obtained using solid acid catalysts have shown that the reaction with IB proceeds at a high rate but the formation of undesired di-isobutene (DIB) represents a serious problem when catalysts with high density of acid sites, such as Amberlyst, are used. When using TBA as a reactant, the main problem is the formation of water that, due to thermodynamic reasons, prevents the formation of poly-substituted ethers regardless of the catalyst used. Some preliminary experiments carried out with a water permselective tubular membrane have demonstrated that the yield of poly-substituted ethers significantly increases once water was selectively removed from the reaction medium by recirculation of the gas phase.
{"title":"Catalytic production of oxygenated additives by glycerol etherification","authors":"C. Cannilla, G. Bonura, L. Frusteri, F. Frusteri","doi":"10.2478/s11532-014-0546-y","DOIUrl":"https://doi.org/10.2478/s11532-014-0546-y","url":null,"abstract":"In this work the etherification reaction of glycerol with isobutene (IB) and tert-butyl alcohol (TBA) has been studied with the aim of preparing mixtures with high content of poly-substituted ethers. The results obtained using solid acid catalysts have shown that the reaction with IB proceeds at a high rate but the formation of undesired di-isobutene (DIB) represents a serious problem when catalysts with high density of acid sites, such as Amberlyst, are used. When using TBA as a reactant, the main problem is the formation of water that, due to thermodynamic reasons, prevents the formation of poly-substituted ethers regardless of the catalyst used. Some preliminary experiments carried out with a water permselective tubular membrane have demonstrated that the yield of poly-substituted ethers significantly increases once water was selectively removed from the reaction medium by recirculation of the gas phase.","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"1 1","pages":"1248-1254"},"PeriodicalIF":0.0,"publicationDate":"2014-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86677642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-01DOI: 10.2478/s11532-013-0405-2
Anamika Roy, Sunil Kumar Singh, J. Bajpai, A. Bajpai
Polymers have been widely used in agriculture for applications including controlled release of pesticides and other active ingredients. The ability to predict their delivery helps avoid environmental hazards. Macromolecular matrices used as carriers in controlled release of agricultural active agents, especially pesticides, are reviewed. The review focuses on the advantages and mechanisms of controlled release. It includes biodegradable polymers in agriculture, their manufacturing methods, and their degradation mechanisms and kinetics. The article also presents a critical account of recent release studies and considers upcoming challenges.
{"title":"Controlled pesticide release from biodegradable polymers","authors":"Anamika Roy, Sunil Kumar Singh, J. Bajpai, A. Bajpai","doi":"10.2478/s11532-013-0405-2","DOIUrl":"https://doi.org/10.2478/s11532-013-0405-2","url":null,"abstract":"Polymers have been widely used in agriculture for applications including controlled release of pesticides and other active ingredients. The ability to predict their delivery helps avoid environmental hazards. Macromolecular matrices used as carriers in controlled release of agricultural active agents, especially pesticides, are reviewed. The review focuses on the advantages and mechanisms of controlled release. It includes biodegradable polymers in agriculture, their manufacturing methods, and their degradation mechanisms and kinetics. The article also presents a critical account of recent release studies and considers upcoming challenges.","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"5 1","pages":"453-469"},"PeriodicalIF":0.0,"publicationDate":"2014-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90276680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-03-19DOI: 10.2478/s11532-014-0542-2
L. Gyenge, B. Raduly, S. Crognale, S. Lányi, Beáta Ábrahám
This study investigated the individual and interactive effects of three factors — temperature, inoculum/substrate ratio (ISR) and inoculum typology — on the anaerobic digestion of corn ethanol distillery wastewater. Biochemical methane potential assays planned with factorial design with two independent quantitative variables on three levels (ISR: 1:1, 2:1 and 3:1; temperature: 30°C, 33.5°C, 37°C) and one independent qualitative variable (inoculum type: suspended, granular, mixed) have been performed. Response Surface Methodology has been used to study the effect of the factors with the aim of maximizing the specific methane yields (YCH4) obtainable with this substrate. The results show that all three investigated factors influence in a significant matter the YCH4, the ISR having the strongest effect on it. The temperature has significant influence on the YCH4 only in combination with high ISR values. The optimal conditions for the maximum YCH4 (551 mL CH4 g−1 VSadded) have been found at 37°C operating temperature, ISR=3:1 and using granular inoculum. These conditions gave rise to a 4-fold increase of YCH4 with respect to the worst combination of factors (YCH4=129 mL g−1 VSadded for the suspended inoculum type, at 30°C and ISR=1:1). The results improve the knowledge on the digestion of this substrate, providing information for successful process up-scaling.
研究了温度、接种物/底物比(ISR)和接种物类型对玉米乙醇蒸馏废水厌氧消化的影响。生化甲烷电位测定计划采用因子设计，在三个水平(ISR: 1:1, 2:1和3:1)上有两个独立的定量变量;温度:30°C, 33.5°C, 37°C)和一个独立的定性变量(接种类型:悬浮，颗粒状，混合)进行了测试。利用响应面法研究了各因素的影响，目的是使该底物的比甲烷产率(YCH4)最大化。结果表明，三种因子对YCH4的影响均显著，其中ISR对YCH4的影响最大。温度只有在高ISR值的情况下才对YCH4有显著影响。在37℃工作温度、ISR=3:1和颗粒接种条件下，获得最大YCH4 (551 mL CH4 g−1 vs1)的最佳条件。在这些条件下，与最坏的因素组合相比，YCH4增加了4倍(悬浮接种型的YCH4=129 mL g−1 vsv，在30°C和ISR=1:1)。结果提高了对该底物消化的认识，为成功的工艺放大提供了信息。
{"title":"Cultivating conditions optimization of the anaerobic digestion of corn ethanol distillery residuals using response surface methodology","authors":"L. Gyenge, B. Raduly, S. Crognale, S. Lányi, Beáta Ábrahám","doi":"10.2478/s11532-014-0542-2","DOIUrl":"https://doi.org/10.2478/s11532-014-0542-2","url":null,"abstract":"This study investigated the individual and interactive effects of three factors — temperature, inoculum/substrate ratio (ISR) and inoculum typology — on the anaerobic digestion of corn ethanol distillery wastewater. Biochemical methane potential assays planned with factorial design with two independent quantitative variables on three levels (ISR: 1:1, 2:1 and 3:1; temperature: 30°C, 33.5°C, 37°C) and one independent qualitative variable (inoculum type: suspended, granular, mixed) have been performed. Response Surface Methodology has been used to study the effect of the factors with the aim of maximizing the specific methane yields (YCH4) obtainable with this substrate. The results show that all three investigated factors influence in a significant matter the YCH4, the ISR having the strongest effect on it. The temperature has significant influence on the YCH4 only in combination with high ISR values. The optimal conditions for the maximum YCH4 (551 mL CH4 g−1 VSadded) have been found at 37°C operating temperature, ISR=3:1 and using granular inoculum. These conditions gave rise to a 4-fold increase of YCH4 with respect to the worst combination of factors (YCH4=129 mL g−1 VSadded for the suspended inoculum type, at 30°C and ISR=1:1). The results improve the knowledge on the digestion of this substrate, providing information for successful process up-scaling.","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"39 1","pages":"868-876"},"PeriodicalIF":0.0,"publicationDate":"2014-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86190491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-03-19DOI: 10.2478/s11532-014-0543-1
G. Pawlik, W. Radosz, A. Mituś, J. Myśliwiec, A. Miniewicz, F. Kajzar, I. Rău
We study experimentally the dynamics of holographic inscription of gratings in DR1:DNA-CTMA thin films using a degenerate two-wave mixing (DTWM) setup in its initial phase (30 ms) and in a longer time interval (30 s). The temporal pattern of evolution of diffraction efficiency is complex, simple fitting procedures fail to reproduce the data. We point out that the complex dynamics can originate a large span of temporal scales, closely related to the microscale inhomogeneity of local free volume. Some of its hallmarks are found through Monte Carlo simulations.
{"title":"Holographic grating inscription in DR1: DNA-CTMA thin films: the puzzle of time scales","authors":"G. Pawlik, W. Radosz, A. Mituś, J. Myśliwiec, A. Miniewicz, F. Kajzar, I. Rău","doi":"10.2478/s11532-014-0543-1","DOIUrl":"https://doi.org/10.2478/s11532-014-0543-1","url":null,"abstract":"We study experimentally the dynamics of holographic inscription of gratings in DR1:DNA-CTMA thin films using a degenerate two-wave mixing (DTWM) setup in its initial phase (30 ms) and in a longer time interval (30 s). The temporal pattern of evolution of diffraction efficiency is complex, simple fitting procedures fail to reproduce the data. We point out that the complex dynamics can originate a large span of temporal scales, closely related to the microscale inhomogeneity of local free volume. Some of its hallmarks are found through Monte Carlo simulations.","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"18 1","pages":"886-892"},"PeriodicalIF":0.0,"publicationDate":"2014-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83832938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-03-19DOI: 10.2478/s11532-014-0538-y
T. Zaharescu, R. Setnescu, I. Borbath
AbstractMagnetic fluid applications require stability under demanding conditions. Complete magnetic fluids and their component surfactants and dispersing oils were irradiated. Their subsequent thermal oxidation was characterized by chemiluminescence and DSC. Except for polyisobutylsuccinic anhydride, irradiation sensitized the components toward oxidation. The components were ranked by stability. Complete fluids were more stable than would be predicted from their components suggesting that they may be used for nuclear applications.
{"title":"Thermal oxidation of irradiated magnetic fluids and their component surfactants and dispersing oils","authors":"T. Zaharescu, R. Setnescu, I. Borbath","doi":"10.2478/s11532-014-0538-y","DOIUrl":"https://doi.org/10.2478/s11532-014-0538-y","url":null,"abstract":"AbstractMagnetic fluid applications require stability under demanding conditions. Complete magnetic fluids and their component surfactants and dispersing oils were irradiated. Their subsequent thermal oxidation was characterized by chemiluminescence and DSC. Except for polyisobutylsuccinic anhydride, irradiation sensitized the components toward oxidation. The components were ranked by stability. Complete fluids were more stable than would be predicted from their components suggesting that they may be used for nuclear applications.\u0000","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"45 1","pages":"782-787"},"PeriodicalIF":0.0,"publicationDate":"2014-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89141392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-03-13DOI: 10.2478/s11532-014-0531-5
E. Tolis, D. Saraga, George Z. Ammari, E. Gkanas, Theofilos Gougoulas, Christina C. Papaioannou, Anastasios K. Sarioglou, Eleftherios Kougioumtzidis, Athina Skemperi, J. Bartzis
Eordaia basin located in northwest of Greece, comprises an area which is characterized by intense energy related activities, including coal burning at four power plants and the associated mining operations. Air samples of inhalable (PM10) and respirable particles (PM2.5) were collected in cold and warm periods in 2010 at an urban background site of Kozani, the major city and capital of the region which is located close to the power plants. Particulate matter concentration, particle-bound polycyclic aromatic hydrocarbons and anionic species concentrations were determined using gravimetric, GC-MS in SIM mode and Ion Chromatography analysis, respectively. For the cold period, the mean PM10 and PM2.5 mass concentration was found to be 19.62 and 14.68 µg m−3, respectively. Correspondingly, for the warm period, the mean PM10 and PM2.5 values were 35.29 and 25.75 µg m−3, respectively. In general, the results indicated that the major sources of air pollution in Kozani are traffic, combustion from agricultural activities and lignite power plants emissions, contributing by different percentages to each particle fraction.
{"title":"Chemical characterization of particulate matter (PM) and source apportionment study during winter and summer period for the city of Kozani, Greece","authors":"E. Tolis, D. Saraga, George Z. Ammari, E. Gkanas, Theofilos Gougoulas, Christina C. Papaioannou, Anastasios K. Sarioglou, Eleftherios Kougioumtzidis, Athina Skemperi, J. Bartzis","doi":"10.2478/s11532-014-0531-5","DOIUrl":"https://doi.org/10.2478/s11532-014-0531-5","url":null,"abstract":"Eordaia basin located in northwest of Greece, comprises an area which is characterized by intense energy related activities, including coal burning at four power plants and the associated mining operations. Air samples of inhalable (PM10) and respirable particles (PM2.5) were collected in cold and warm periods in 2010 at an urban background site of Kozani, the major city and capital of the region which is located close to the power plants. Particulate matter concentration, particle-bound polycyclic aromatic hydrocarbons and anionic species concentrations were determined using gravimetric, GC-MS in SIM mode and Ion Chromatography analysis, respectively. For the cold period, the mean PM10 and PM2.5 mass concentration was found to be 19.62 and 14.68 µg m−3, respectively. Correspondingly, for the warm period, the mean PM10 and PM2.5 values were 35.29 and 25.75 µg m−3, respectively. In general, the results indicated that the major sources of air pollution in Kozani are traffic, combustion from agricultural activities and lignite power plants emissions, contributing by different percentages to each particle fraction.","PeriodicalId":9888,"journal":{"name":"Central European Journal of Chemistry","volume":"10 1","pages":"643-651"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81325205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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