Search results for "trap"

Recent Development in Analytical Methods for Identification of Off-Flavour Compounds

1983

The best resolution of individual off-flavour compounds is achieved by glass or quartz capillary gas chromatography. A special two-column system was used by which simultaneous instrumental detection and sniffing (odour desorption) of odorous compounds could be done. The measuring detectors were flame ionization (FID), electron capture (ECD), flame photometric (FPD) and a mass spectrometer (MS). Structural assignments of the odorous substances were done from MS data and verified by model compounds. Before the GC run the sample was collected at the head of the double column using a cold trap device. The sample for analysis was injected in liquid form or, more efficiently, thermally desorbed f…

Determination of pharmaceutical residues and assessment of their removal efficiency at the Daugavgriva municipal wastewater treatment plant in Riga, …

2017

Pharmaceutical products (PPs) belong to emerging contaminants that may accumulate along with other chemical pollutants in wastewaters (WWs) entering industrial and/or urban wastewater treatment plants (WWTPs). In the present study, the technique of ultra-high-performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry (Orbitrap-HRMS) was applied for the analysis of 24 multi-class PPs in WW samples collected at different technological stages of Daugavgriva WWTP located in Riga, Latvia. Caffeine and acetaminophen levels in the range of 7,570–11,403 ng/L and 810–1,883 ng/L, respectively, were the predominant compounds among 19 PPs determined in the WW. The results i…

Influence of Welding Time on Tensile-Shear Strength of Linear Friction Welded Birch (Betula pendula L.) Wood

2015

Linear friction welding of wood is a bonding process applied to wood and during which a stiff bond line is formed by the softening and rehardening of wood components to form a composite material composed mainly of wood fibres embedded in a modified lignin matrix. Unfortunately, the bonds tend to spontaneously delaminate or lose their strength when exposed to moist conditions. Some approaches were previously applied to overcome this problem, but so far a suitable solution has not been found. This paper presents results of applying post-welding thermal modification to reduce the moisture sensitivity of welded wood. The experiments included welding of birch wood, thermal modification under sup…

Analysis of perfluoroalkyl substances in waters from Germany and Spain

2012

Water has been identified as one of the main routes of human exposure to perfluoroalkyl substances (PFASs). This work assessed the presence of 21 PFASs along the whole water cycle using a new fast and cost effective analytical method based on an online sample enrichment followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method was validated for different types of matrices (ultrapure water, tap water and treated wastewater). The quality parameters for the 21 selected compounds presented good limits of detection (LOD) and quantification (LOQ) ranging, in general, from 0.83-10 ng/L to 2.8-50 ng/L, respectively. The method was applied to assess the occurrence …

Le iscrizioni greche

2009

Non-parametric probabilistic forecasting of academic performance in Spanish high school using an epidemiological modelling approach

2013

Academic underachievement is a concern of paramount importance in Europe, and particularly in Spain, where around of 30% of the students in the last two courses in high school do not achieve the minimum knowledge academic requirement. In order to analyse this problem, we propose a mathematical model via a system of ordinary differential equations to study the dynamics of the academic performance in Spain. Our approach is based on the idea that both, good and bad study habits, are a mixture of personal decisions and influence of classmates. Moreover, in order to consider the uncertainty in the estimation of model parameters, a bootstrapping approach is employed. This technique permits to for…

Tetrakis{[(p-dodecacarboranyl)methyl]stilbenyl}ethylene: A Luminescent Tetraphenylethylene (TPE) Core System

2017

The synthesis and spectroscopic characterization of the first set of tetra(p-dodecacarborane-stilbeno)ethylenes (TDSE), substituted either with a methyl or phenyl group in the 2-position (Ccluster) of the ortho-carborane, are described. The complex absorption properties are elucidated by TD-DFT calculations, stressing the importance of through bond conjugation. Enhanced conjugation and restriction of the conformational space are identified as the main factors for boosted luminescence properties in solution compared to tetraphenylethylene (TPE) core, effectively reducing internal conversion (IC). IC is further reduced when aggregate suspensions of our compounds in water are formed, providing…

Determination and comparison of acidic gas ratios at the Stromboli Volcano and Mount Etna obtained by various active alkaline traps

2013

Pharmakologisch-aktive polymere, 18. Körperverteilung und ausscheidungsverhalten von monomerem und polymerem sulfadiazinacrylamid

1979

Sulfadiazinacrylamid was absorbed after oral and intraperitoneal application in rats to a high extent; the absorption from the intraperitoneum was retarded. Glucose treatment delayed the absorption after both application forms. At comparatively high renal and enteral excretion rates the biological half life time of the monomer was estimated to 8 h. A tumouraffinity was not found but there were indications for a preferred storage in the RES. Poly[sulfadiazinacrylamide] was absorbed after intraperitoneal injection to a clear extent, where at the beginning of the treatment under simultaneous glucose load the absorption was delayed. 24 h after injection higher concentrations in metabolic organs…

Sequential recruitment of the mRNA decay machinery to the iron-regulated protein Cth2 in Saccharomyces cerevisiae

2020

Post-transcriptional factors importantly contribute to the rapid and coordinated expression of the multiple genes required for the adaptation of living organisms to environmental stresses. In the model eukaryote Saccharomyces cerevisiae, a conserved mRNA-binding protein, known as Cth2, modulates the metabolic response to iron deficiency. Cth2 is a tandem zinc-finger (TZF)-containing protein that co-transcriptionally binds to adenine/uracil-rich elements (ARE) present in the 3′-untranslated region of iron-related mRNAs to promote their turnover. The nuclear binding of Cth2 to mRNAs via its TZFs is indispensable for its export to the cytoplasm. Although Cth2 nucleocytoplasmic transport is ess…