Search results for "exclusion"

Step-by-step analysis of drinking water treatment trains using size-exclusion chromatography to fingerprint and track protein-like and humic/fulvic-l…

2019

This paper provides a glimpse into the removal of dissolved organic matter (DOM) during conventional drinking water treatment and evaluates the potential of high-performance size-exclusion chromatography (HPSEC) as a supplementary tool for routine monitoring of drinking water treatment plants (DWTPs). Two DWTPs in Central Finland were systematically evaluated using HPSEC with simultaneous UV and fluorescence detection. For tyrosine-like, tryptophan-like, and humic/fulvic-like DOM fractions of various molecular weight (MW) values, the total and step-by-step removal efficiencies were estimated along the treatment trains. Overall, both DWTPs removed ∼70% of dissolved organic carbon (DOC) and r…

CTR: A calculus of timed refinement

1995

This paper presents CTR — a process algebraic framework for loose specification of time quantity sensitive operational behaviour of reactive systems. CTR terms are provided both with operational and specification semantics (via the notion of specification refinement). Besides the intuitive justification of appropriateness of the refinement notion, a preservation theorem is proved for a timed variant of Hennessy-Milner logic. A comparison of CTR with the related formalism of Timed Modal Specifications, and with the timed process calculi TCCS due to Wang is given. Some pragmatics of the application of CTR is sketched on a critical resource access example.

Framing the public: the policy process around xenotransplantation in Latvia and Sweden 1970–2004

2011

A crucial debate is under way concerning the public's participation in biotechnology decision-making processes. This study, concerning the policy process around xenotransplantation (XTP) in Latvia and Sweden in the period 1970–2004, focuses on how scientific experts and politicians view the public and the public's participation in the process of developing policy regarding XTP. Drawing on interviews with actors involved in XTP in each country, we analyse and explain the inclusion and exclusion of publics in policy decision-making processes. In particular, we highlight the significance of the role of scientists and politicians in generating discourses which exclude the public from participat…

Keyhole limpet haemocyanin (KLH): Purification of intact KLH1 through selective dissociation of KLH2

1995

Abstract Keyhole limpet haemocyanin (KLH) from almost all newly captive animals contains a mixture of KLH1 and KLH2. We show that the dissociation of KLH2 can be produced during EM specimen preparation by the negative staining-carbon film (NS-CF) procedure and in solution by ammonium molybdate-PEG solutions at slightly acidic pHs. The KLH2 multidecamers split apart in the pH range 7.5-6.5 and in the pH range 6.5-6.0 the individual decamers break open and start to dissociate. At pH 5.9 the dissociation of KLH2 yields predominantly a mixture of single subunits and what appear to be subunit dimers. Over the pH range 7.0-5.7 the KLH1 didecamer remains stable. Separation of intact KLH1, in the f…

Fluorescence of soil humic acids and their fractions obtained by tandem size exclusion chromatography-polyacrylamide gel electrophoresis

2002

Humic acids (HAs) extracted from soils of different origin (chernozem, ferralsol and ranker) and their fractions (A, B and C+D) obtained by tandem size exclusion chromatography–polyacrylamide gel electrophoresis were investigated by steady-state fluorescence spectroscopy in the emission mode. Independently of HA source, high molecular size fractions A and B are shown to be weakly fluorescent. The main fluorophores, especially those emitting at long wavelength (around 500–510 nm), are contained in the polar and low molecular size fractions C+D. As indicated by the observed pH effect, aromatic structures bearing carboxylate and OH substituents may be involved in these longer wavelength emissi…

Solution properties of polyelectrolytes. III. Effect of sodium polystyrene sulfonate concentration on viscometric and size exclusion chromatographic …

1988

The effect of sodium polystyrene sulfonate concentration on the shape of its molecules in aqueous solution at different NaNO3 ionic strengths has been analyzed by viscometry and size-exclusion chromatography (s.e.c). An equation has been developed which predicts the intrinsic viscosity, [η] p.cp.cs, at finite concentration of both polyion (cp) and electrolyte (cs). The experimental results obtained by both techniques can be accounted for in terms of the theory. Several factors involved in the elution mechanism have been considered and the variation of the slopes of s.e.c. calibration curves with cp and cs has been discussed in terms of polyion conformation changes.

Solution properties of polyelectrolytes. I. Exclusion chromatography of sodium polystyrene sulphonate in salt-free water as eluent

1987

The effect of concentration of sodium polystyrene sulphonate on the elution volume in exclusion chromatography has been investigated using salt-free water as eluent. A non-linear increase in the elution volume has been observed with increasing injected sample concentration. Concentration-dependent calibrations have been obtained which approach the universal calibration for uncharged polymers (dextrans) as polyelectrolyte concentration increases. The separation mechanisms are interpreted in terms of electrostatic and hydrodynamic interactions. A semi-empirical model is proposed to predict concentration effects of linear polyions in exclusion chromatography and good agreement has been found b…

Gel permeation chromatography, calibration, and distributions of cellulose trinitrates

1967

Molar Mass Distribution and Size of Hydroxyethyl Starch Fractions Obtained by Continuous Polymer Fractionation

2002

By the use of continuous polymer fractionation (CPF) the initial polymer can be separated into fractions of different molar masses, which makes it possible to obtain hydroxyethyl starch (HES) fractions tailor-made for specific application. Two samples of HES (HES A and HES B) were fractionated by means of CPF. By size-exclusion chromatography-multi-angle laser light-scattering-differential refractive index (SEC/ MALLS/DRI) measurements it was shown that CPF is able to remove the low-molar-mass components and to adjust the samples to various desired molar masses with lower polydispersities than the original samples. In terms of the weight-average mean molar mass M w , the sol fractions have …

Prosocial and Aggressive Behavior Occurrence in Young Athletes: Field Research Results in Six European Countries

2020

Aggression and violence among youth are researched as social phenomena in sport. This paper was designed to determine the occurrence of these behaviors as well as prosocial behaviors among young athletes. The current paper is a research report aiming to detect the frequency of aggressive behavior, social exclusion, prosocial behavior and cohesion in the youth environment, the frequency of personal experience of peer violence or social exclusion, and to evaluate cross-national differences in terms of occurrence of these phenomena.The field research was conducted in six European countries (Austria, Bosnia and Herzegovina, Croatia, Italy, Lithuania, and Serbia) on a sample of 482 children aged…