Browsing Τμήμα Χημείας / Department of Chemistry by Title
Now showing items 860-879 of 1320
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Radioactivity and metal concentrations in marine sediments associated with mining activities in Ierissos Gulf, North Aegean Sea, Greece
(2016)Marine sediment samples were collected from Ierissos Gulf, N Aegean Sea, close to the coastal mining facilities. Measurements of radionuclide and metal concentrations, mineral composition and grain size distribution were ...
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Radioactivity/Radionuclide (U-232 and Am-241) Removal from Waters by Polyurea-Crosslinked Alginate Aerogels in the Sub-Picomolar Concentration Range
(MDPI, 2023)The removal of radionuclide/radioactivity from laboratory and environmental water samples under ambient conditions was investigated via batch-type experiments using polyurea-crosslinked calcium alginate (X-alginate) aerogels. ...
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Radiometric analysis of potassium, radium and uranium levels in Brazil nuts
(Springer, 2023)The paper describes an alternative approach for the determination of uranium, radium-226 and potassium levels in Brazil nuts. Potassium analysis was performed by a NaI detector using 1-gram of nut’s ashes, radium analysis ...
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Radiometric determination of uranium in natural waters after enrichment and separation by cation-exchange and liquid-liquid extractionAAA
(2004)Preconcentration of uranium from natural water samples using Chelex-100 cation-exchange resin, its selective extraction by tributylphosphate and electrodeposition on stainless steel discs is reported. The validity of the ...
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Radionuclide removal from aqueous solutions using Oxidized Carbon Fabrics
(MDPI, 2023)The adsorption of actinide ions (Am(III) and U(VI)) from aqueous solutions using pristine and oxidized carbon fabrics was investigated by means of batch experiments at different pH values (pH 4, 7 and 9) and temperatures ...
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Radium concentration in uranium-bearing rocks and minerals by radon emanation after acidic sample dissolution
(2016)The applicability of a radon emanation system to radium determination in NORM materials after acidic sample dissolution has been investigated by means of a closed recirculating air loop radon emanation system. After system ...
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Radium removal from aqueous solutions by adsorption on non-treated and chemically modified biomass by-product
(2013)The adsorption efficiency of a biomass by-product (olive cake) regarding the removal of radium (226Ra) from aqueous solutions has been investigated prior and after its chemical treatment. The chemical treatment of the ...
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Radon emanation from phosphogypsum and related mineral samples in Cyprus
(2007)Radon emanation rates from phosphogypsum samples have been determined to assess the radiological impact of radon emanated from a phosphogypsum disposal site. For comparison corresponding measurements were conducted with ...
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Radon exhalation from granite countertops and expected indoor radon levels
(2017)Radon (222Rn) exhalation rates from granite countertops were measured using a continuous radon monitor. The countertops could be separated in three groups according to radon their exhalation rates. However, even for a ...
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Radon levels in Cyprus
(2003)Radon levels in atmospheric and aquatic systems in Cyprus have recently been measured using the radon monitor Alpha Guard. Indoor and outdoor radon levels were obtained in situ, whereas analysis of radon concentrations in ...
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Rainwater characteristics over an old sulphide mine refuse in Sha, Cyprus
(2003)Rainwater characteristics over an old mining area have been investigated on the basis of long-term sample collection and determination of physical parameters and chemical composition. The experimental data, which were ...
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Randomly cross-linked homopolymer networks: Synthesis by group transfer polymerization in solution and characterization of the aqueous degree of swelling
(2001)Randomly cross-linked homopolymer networks of 2-(dimethylamino)ethyl methacrylate (DMAEMA) of various average degrees of polymerization (DPs) between cross-links were synthesized by group transfer polymerization (GTP) in ...
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Rare Nuclearities and Unprecedented Structural Motifs in Manganese Cluster Chemistry from the Combined Use of Di-2-Pyridyl Ketone with Selected Diols †
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-01)The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3)∙2DMF∙H2O (1∙2DMF∙H2O), ...
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Rare nuclearities in Mn/oxo cluster chemistry: Synthesis and characterization of a mixed-valence {MnII/III11} complex bearing acetate and salicylhydroximate(-3) bridging/chelating ligands
(Elsevier, 2021-09-15)The one-pot reaction between Mn(O2CMe)2·4H2O, salicylhydroxamic acid (shaH2) and Me4NOH·5H2O in a molar ratio of 2:1:2, and a solvent mixture comprising MeCN and MeOH, affords the new mixed-valence cluster compound ...
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Rare oxidation-state combinations and unusual structural motifs in hexanuclear Mn complexes using 2-pyridyloximate ligands
(2010)The use of phenyl-2-pyridyl ketone oxime and di-2-pyridyl ketone oxime in Mn chemistry has led to hexanuclear clusters with unprecedented (Mn II4MnIIIMnIV) or extremely rare (MnIIMnIII5 and MnII 3MnIII3) metal oxidation-state ...
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Rates of activation and scanning electron microscopy of polyarylamide-derived chars
(1995)Fibrous activated carbons were prepared from Kevlar® (poly (p-phenylene terephthalamide)) and Nomex® (poly (m-phenylene isophthalamide)) by carbonisation in nitrogen and subsequent activation in steam of carbon dioxide to ...
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Article
The reaction of 2-amino-N′-arylbenzamidines with tetracyanoethene reinvestigated: routes to imidazoles, quinazolines and quinolino[2′,3′:4,5]imidazo[1,2-c]quinazoline-8-carbonitrile
(2015)2-Amino-N′-phenylbenzamidine (1a) reacts with tetracyanoethene (TCNE) to give 2-[2-(2-aminophenyl)-5-imino-1-phenyl-1H-imidazol-4(5H)-ylidene]malononitrile (11a), 4-(phenylamino)quinazoline-2-carbonitrile (5a) and ...
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Reaction of 3,4,4,5-tetrachloro-4H-1,2,6-thiadiazine with benzyltriethylammonium chloride
(2018)3,4,4,5-Tetrachloro-4H-1,2,6-thiadiazine was reacted with BnEt3NCl (10 mol%) to give perchloro-9-thia-1,5,8,10-tetraazaspiro[5.5]undeca-1,4,7,10-tetraene (up to 18% yield), 4,5,6-trichloropyrimidine-2-carbonitrile (up to ...
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Article
The reaction of 4,5-dichloro-1,2,3-dithiazolium chloride with dimethylsulfonium dicyanomethylide: an improved synthesis of (4-chloro-1,2,3-dithiazolylidene)malononitrile
(2009)4,5-Dichloro-1,2,3-dithiazolium chloride 6 (Appel salt) reacts with dimethylsulfonium dicyanomethylide 11 to give 5-(4-chloro-1,2,3-dithiazolylidene)malononitrile 1 and a mixture of E/Z isomers of 3-(4-chloro-5H-1,2,3-di ...