Sample records for heida
-
Gabriel, C; Perikli, M; Raptopoulou, C P; Terzis, A; Psycharis, V; Mateescu, C; Jakusch, T; Kiss, T; Bertmer, M; Salifoglou, A
2012-09-03
Hydrothermal pH-specific reactivity in the binary/ternary systems of Pb(II) with the carboxylic acids N-hydroxyethyl-iminodiacetic acid (Heida), 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid (Dpot), and 1,10-phenanthroline (Phen) afforded the new well-defined crystalline compounds [Pb(Heida)](n)·nH(2)O(1), [Pb(Phen)(Heida)]·4H(2)O(2), and [Pb(3)(NO(3))(Dpot)](n)(3). All compounds were characterized by elemental analysis, FT-IR, solution or/and solid-state NMR, and single-crystal X-ray diffraction. The structures in 1-2 reveal the presence of a Pb(II) center coordinated to one Heida ligand, with 1 exhibiting a two-dimensional (2D) lattice extending to a three-dimensional (3D) one through H-bonding interactions. The concurrent aqueous speciation study of the binary Pb(II)-Heida system projects species complementing the synthetic efforts, thereby lending credence to a global structural speciation strategy in investigating binary/ternary Pb(II)-Heida/Phen systems. The involvement of Phen in 2 projects the significance of nature and reactivity potential of N-aromatic chelators, disrupting the binary lattice in 1 and influencing the nature of the ultimately arising ternary 3D lattice. 3 is a ternary coordination polymer, where Pb(II)-Dpot coordination leads to a 2D metal-organic-framework material with unique architecture. The collective physicochemical properties of 1-3 formulate the salient features of variable dimensionality metal-organic-framework lattices in binary/ternary Pb(II)-(hydroxy-carboxylate) structures, based on which new Pb(II) materials with distinct architecture and spectroscopic signature can be rationally designed and pursued synthetically.
-
Study of cyclization of chelating compounds using electrospray ionization mass spectrometry
International Nuclear Information System (INIS)
Shi Ying; Campbell, J.A.
2000-01-01
Electrospray ionization mass spectrometry (ESI-MS) was used for the study of cyclization of organic chelating compounds (chelators). Four chelating compounds were studied: Symmetrical ethylenediaminediacetic acid (s-EDDA), Unsymmetrical ethylenediaminediacetic acid (u-EDDA), N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA), and N-(2-hydroxyethyl)iminodiacetic acid (HEIDA). The chelators were cyclized with treatments of acids and heating. The open and cyclized form of the chelators were semi-quantified by both positive and negative ion modes ESI-MS. The kinetics of chelator cyclization was studied as a function of reaction temperature and the pH of the matrix. The cyclization of s-EDDA was found to be a pseudo-first order reaction in s-EDDA and overall second order. The cyclizations of HEIDA and HEDTA are reversible reactions. Higher temperature and lower pH favors cyclization. (author)
-
Normani ja Pushwagneri juhtum, bb5, ehk Ühe kunstiametniku komandeeringuaruanne / Andreas Trossek
Trossek, Andreas, 1980-
2008-01-01
Koomiksi- ja filmiteemalised mõtted seoses Berliini 5. kaasaegse kunsti biennaaliga "Kui asjad ei heida varje". Pikemalt eesti kunstniku Kristina Normani animalistlikust videofilmist "Geniaalsuse väli" ja Norra kunstniku Hariton Pushwangeri, kodanikunimega Terje Brofoss, joonistuste sarjast "Soft city"
-
Norman Berliinis Einsteini jalajälgedes / Kristina Norman ; interv. Andreas Trossek
Norman, Kristina, 1979-
2008-01-01
5. IV-15. VI toimuva Berliini kaasaegse kunsti bienaali "When things cast no shadows / Kui asjad ei heida varju" (kuraatorid Adam Szymczyk ja Elena Filipovic) öise biennaaliprogrammi "Minu ööd on ilusamad kui teie päevad" raames on 25. V Archenholdi observatooriumis Kristina Normani diafilmi "The Field of Genius / Geniaalsuse väli" (2003) esitlus koos füüsiku ja astrobioloogi Paul Daviese loenguga. K. Norman meiliintervjuus oma diafilmist
-
Chelate-assisted phytoextraction of lead from contaminated soils
Energy Technology Data Exchange (ETDEWEB)
Cooper, E.M.; Sims, J.T.; Cunningham, S.D.; Huang, J.W.; Berti, W.R.
1999-12-01
Phytoextraction, a remediation strategy for lead (Pb)-contaminated soils that removes soil Pb through plant uptake and harvest, may be enhanced by use of synthetic chelates. The authors evaluated Pb desorption from four contaminated soils by seven chelates (CDTA, DTPA, EDDHA, EFTA, HEDTA, HEIDA, and NTA) at three rates. The three most effective chelates (CDTA, DTPA, and HEDTA) were used in greenhouse studies with an uncontaminated soil and a Pb-contaminated soil to determine the effect of chelate type and rate on growth, Pb uptake, and plant elemental composition. Lead desorption varied with chelate and soil and increased with chelate rate, averaging 948 mg Pb kg{sup {minus}1} at the 20 mmol kg{sup {minus}1} rate vs. 28 mg Pb kg{sup {minus}1} by the control. The general ranking of chelate effectiveness, based on total Pb desorbed, was HEDTA > CDTA > DTPA > EGTA > HEIDA > EDDHA {approximately} NTA. Plant uptake of Pb from the contaminated soil was enhanced by CDTA, DTPA, and HEDTA, but with even the most effective treatment (corn, high CDTA rate), the amount of Pb extracted by plants was rather low. Lead extractable by the Toxicity Characteristic Leaching Procedure (TCLP) was increased from 9 mg L{sup {minus}1} in the control to from 47 to 174 mg L{sup {minus}1} in soils treated with 20 mmol kg{sup {minus}1} CDTA or DTPA and chelates generally caused a shift in Pb from resistant to more soluble chemical fractions.
-
Punsár, Taavi
2017-01-01
Opinnäytetyön tarkoitus oli selvittää kroonisesta unettomuudesta kärsivien palautuminen sekä heidän kokemuksia työssä ja elämäntilanteessa olevista palautumista estävistä, haittaavista tai edistävistä tekijöistä. Jokapäiväinen aktiivinen toiminta aiheuttaa palautumisen tarpeen. Voimavaroja kuluttava ja lisäävä toiminta tulisi olla tasapainossa. Keskimäärin palautumista on riittävästi, kun sitä on noin kolmasosa vuorokaudesta. Suuri osa palautumisesta tapahtuu unijak...