Browsing by Subject "CHLORIDE"

Sort by: Order: Results:

Now showing items 1-7 of 7
  • Sitar, Simona; Aseyev, Vladimir; Zagar, Ema; Kogej, Ksenija (2019)
    Dynamic and static light scattering measurements were performed on isotactic and atactic forms of poly (methacrylic acid), iPMA and aPMA, respectively, in order to perform a wide survey of their molecular properties and chain dynamics in water as functions of tacticity, degree of neutralization, alpha(N), and salt concentration, c(s). The molecular parameters of PMA chains were analyzed at low alpha(N) and chain dynamics (diffusion coefficients and in this connection the polyelectrolyte slow mode behavior) at higher alpha(N). The data revealed that both PMAs form microgel-like aggregates with a core-shell structure at low alpha(N) ( = 0 and 0.25 for aPMA and iPMA, respectively). The distribution of the hydrophilic and hydrophobic functional groups within the aggregates and their compactness depended considerably on chain tacticity and for aPMA also on c(s). Further, the effect of c(s) on the polyelectrolyte slow diffusion coefficient, D-s, of partly (0.25
  • Parmentier, Dries; Paradis, Sarah; Metz, Sybrand J.; Wiedmer, Susanne K.; Kroon, Maaike C. (2016)
    This work describes for the first time a continuous process for selective metal extraction with an ionic liquid (IL) at room temperature. The hydrophobic fatty acid based IL tetraoctylphosphonium oleate ([P-8888][oleate]) was specifically chosen for its low viscosity and high selectivity towards transition metals. Applying [P-8888][oleate] for continuous metal ion extraction with 0.1 M sodium oxalate for regeneration resulted in a process with good and stable extraction efficiencies over time. The selectivity of the IL resulted in a process in which cobalt was selectively removed from two mixed salt solutions (Co/Na, Ca/Co/K) to obtain a pure cobalt stream after stripping the IL. The performed experiments showed that the contact time of the IL for extraction and stripping strongly influenced the achieved efficiencies. The stability of the IL was tested and it was shown that the fatty acid based IL was stable for the duration of the experiment. Liposome tests showed that the IL is very hydrophobic, which limits its leakage towards the water phase, but also results in a higher toxicity towards cell membranes. Economic analysis shows that the IL based process is not (yet) economical compared to ion-exchange resins, in case demineralised water is the only product. However, if the recovery of valuable metals is also taken into account and/or if brine disposal is an issue, then continuous IL metal extraction systems must be regarded as promising alternatives. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
  • Nieminen, Heta-Elisa; Kaipio, Mikko; Ritala, Mikko (2020)
    In this work, a growth mechanism of an intermetallic Co3Sn2 thin film is studied in situ with a quartz crystal microbalance (QCM) and quadrupole mass spectrometer (QMS). The film is deposited by atomic layer deposition (ALD) from CoCl2 (TMEDA) and Bu3SnH precursors (TMEDA = N,N,N' ,N' - tetramethylethylenediamine). Balanced reaction equations are resolved by fitting the QMS and QCM data, and a step-by-step growth mechanism is determined for the process. During the CoCl2 (TMEDA) pulse, only 1-chlorobutane is formed as a byproduct. However, during the Bu3SnH pulse, two byproducts, BuCl and Bu3SnCl, were clearly detected, indicating that two competing reaction pathways exist during that pulse. Preliminary studies on another intermetallic ALD process, Ni3Sn2, revealed that the reactions occur similarly as in the Co3Sn2 process.
  • Kyllönen, Lasse; Parviainen, Arno; Deb, Somdatta; Lawoko, Martin; Gorlov, Mikhail; Kilpeläinen, Ilkka; King, Alistair W. T. (2013)
  • Aly, Ashraf A.; Hassan, Alaa A.; Mohamed, Nasr K.; Ramadan, Mohamed; Brown, Alan B.; Abd El-Aal, Amal S.; Bräse, Stefan; Nieger, Martin (2019)
    A general method for the synthesis of 1,3,5-trisubstituted 1,2,4-triazoles has been developed from reaction of amidrazones with ethyl azodicarboxylate and triethylamine (Mitsunobu reagent) in EtOH. This highly regioselective one-pot process provides rapid access to highly diverse triazoles. The reaction was explained, based on Mitsunobu reagent oxidizing ethanol to acetaldehyde, which would then react with amidrazones to give the substituted 3-methyltriazoles. A [2 + 3] cycloaddition reaction between two oxidized forms of amidrazones produced the second type of triazoles. X-ray structure analyses proved the structure of each type of product. [GRAPHICS] .
  • EFSA Panel Dietetic Products Nutr (2018)
    Following an application from Flan-Biotech GmbH, submitted for authorisation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of Germany, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to Symbiosal((R)), lowering of blood pressure and reduced risk of hypertension. The Panel considers that the food, Symbiosal((R)), which is the subject of the health claim, and the food, table salt, which Symbiosal((R)) should replace, are sufficiently characterised. Lowering of blood pressure is a beneficial physiological effect. Increased blood pressure is a risk factor for hypertension. In weighing the evidence, the Panel took into account that one human study with some methodological limitations showed an effect of Symbiosal((R)) on blood pressure in the context of a self-selected diet with a maximum of 3 g/day added salt. The Panel also took into account that no other human studies in which these results have been replicated were provided, that the animal studies did not support the results of the human study, that no evidence was provided in support of a mechanism by which Symbiosal((R)) could induce a decrease in blood pressure upon oral consumption as compared to table salt in vivo in humans, and the low biological plausibility of the effect observed in the human intervention study. The Panel concludes that a cause and effect relationship has not been established between the consumption of Symbiosal((R)) and lowering of blood pressure. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.
  • Aromaa, Hanna; Voutilainen, Mikko; Ikonen, Jussi; Yli-Kaila, Maarit; Poteri, Antti; Siitari-Kauppi, Marja (2019)
    The spent nuclear fuel in Finland will be deposited in crystalline granitic rock in Olkiluoto, Finland. As a part of the safety assessment of the repository, series of extensive in-situ sorption and diffusion experiments and supplementary laboratory work has been done in the Olkiluoto site. Through Diffusion Experiment in a laboratory (TDElab) aims to provide applicable data for the ongoing in-situ experiment in Olkiluoto. This laboratory scale experiment resembles the in-situ experiment and aims to gain information on possible effects in values of distribution coefficients, effective diffusion coefficient and porosity that are caused by differences in laboratory and in-situ conditions. The through diffusion and sorption of tracer solution with known activities of HTO, 36Cl, 133Ba and 134Cs were studied in a decimeter scale sample of veined gneiss, which is one of the main rock types in Olkiluoto. The measured breakthrough curves were modeled taking into account the porosity of the rock and diffusion and sorption of the radionuclides using Time-Domain Random Walk (TDRW) simulations. The porosities of 0.7–0.8% were determined for the rock and effective diffusion coefficients of (3.5 ± 1.0) × 10−13 m2/s and (3.0 ± 1.0) × 10−13 m2/s were determined for HTO and 36Cl, respectively. The porosity and effective diffusion coefficients were found to be in agreement with previous results for veined gneiss. Furthermore, distribution coefficients of (1.0 ± 0.3) × 10−4 m3/kg and (2.0 ± 0.5) × 10−3 m3/kg were determined for 133Ba and 134Cs, respectively, using information about the effective diffusion coefficient determined for HTO. The distribution coefficients were found to be significantly smaller than the ones determined for crushed rock in previous studies and slightly smaller than the ones from previous in-diffusion experiments.