Search results for "Ultrapure water"
showing 4 items of 4 documents
A New Look at Homogeneous Ice Nucleation in Supercooled Water Drops
1995
Abstract The classical theory for homogeneous ice nucleation in supercooled water is investigated in the light of recent data published in various physico-chemical journal on the physical properties of supercooled water and in the light of recent evidence that the cooperative nature of the hydrogen bonds between water molecules is responsible for a singularity behavior of pure supercooled water at −45°C. Recent rates for homogeneous ice nucleation in supercooled water drops field from field experiments at the cirrus cloud level and from cloud chamber studies were shown to be quantitatively in agreement with the laboratory-derived lowest temperatures to which ultrapure water drops of a given…
Determination of glyphosate and aminomethylphosphonic acid in natural water using the capillary electrophoresis combined with enrichment step
2005
A previously elaborated capillary electrophoresis (CE) method used for the determination of glyphosate and aminomethylphosphonic acid (AMPA) was slightly modified in order to improve the sensitivity. However, detection limits attained (5 μg mL−1 for glyphosate and 4 μg mL−1 for AMPA) were still not satisfactory for analytical purposes, thus the addition of a preconcentration step before the CE analysis was proposed. AMBERLITE®IRA-900, a strong anion-exchange resin, was used to preconcentrate both analytes in environmental aqueous samples. The experimental conditions optimised in a previous work were readapted, by decreasing the eluent concentration due to CE limitations. Satisfactory result…
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 …
Effect of polyethelene oxide on the thermal degradation of cellulose biofilm - Low cost material for soft tissue repair in dentistry
2016
Background Bio cellulose is a byproduct of sweet tea fermentation known as kombusha. During the biosynthesis by bacteria cellulose chains are polymerized by enzyme from activated glucose. The single chains are then extruded through the bacterial cell wall. Interestingly, a potential of the Kombucha's byproduct bio cellulose (BC) as biomaterial had come into focus only in the past few decades. The unique physical and mechanical properties such as high purity, an ultrafine and highly crystalline network structure, a superior mechanical strength, flexibility, pronounced permeability to gases and liquids, and an excellent compatibility with living tissue that reinforced by biodegradability, bio…