186 research outputs found
Electron spin resonance for the detection of paramagnetic species: from fundamentals to computational methods for simulation and interpretation
No full textApplications of computational intelligence techniques in chemical and biochemical analysis
No full text"Real-world" evaluation of lipid oxidation products and trace metals in French fries from two chain fast-food restaurants
No full textDifferences in lipid oxidation products (LOPs) and trace metal concentrations of French fry samples found between two global chain fast-food restaurants in the UK were investigated using high-resolution proton nuclear magnetic resonance ( H NMR) and inductively coupled plasma-optical emission spectrometry (ICP-OES) analyses, respectively, of extracts derived therefrom. Over the course of 3 days and 3 different diurnal time periods, samples of French fries (FFs) were analyzed, and comparisons of two different oil extraction methods were undertaken for the two restaurants involved. The magnitude of concentrations of LOPs extracted from FFs is discussed. Significant differences between 6/7 aldehyde classifications, and aluminum, manganese, vanadium, lead, iron, copper and nickel levels between samples from the two restaurants are also reported. Redox-active transition and further trace metal concentrations inversely correlated with FF oil sample LOP contents; this suggested an antioxidant rather than a pro-oxidant role for them. [Abstract copyright: Copyright © 2021 Le Gresley, Ampem, De Mars, Grootveld and Naughton.
Tooth-whitening activity of a novel home-bleaching system utilising thermal diffusion : a multifactorial simultaneous evaluation of efficacy at cervical, body and incisal tooth sites
No full textIntroduction The ability of a thermal diffusion system (TDS) to promote the tooth-whitening actions of a bleaching gel/bleaching activator combination product (containing a final hydrogen peroxide (H2O2) content of 10.0% (w/v)) towards discoloured 'smile-zone' teeth was examined.
Methods Fifty teeth in 15 participants aged 18-62 years were investigated. The CIE tooth shade parameters L*, a* and b*, together with Vitapan shade scores (VSSs), were simultaneously recorded at three separate tooth areas (cervical, body and incisal sites) with a novel spectrophotometric monitoring system before treatment, and also at 14 days after completion of a 10-day treatment period in which the product was applied 'at-home' (twice daily).
Results The tooth-whitening treatment administered gave rise to extremely significant increases in L*, and decreases in the a* and b* shade parameters for each of the tooth areas investigated (p <10−10). Post-treatment mean decreases in the VSS values were 8.26, 9.70 and 9.14 for the cervical, body and incisal areas respectively (p <10−8 in each case). Mean ΔE values determined post-treatment were also very highly significant for each tooth region examined (p <10−10 in each case).
Conclusions The tooth-whitening system tested exerted extremely powerful bleaching actions in all tooth areas investigated. The order of tooth-whitening effectiveness was body > incisal > cervical for Δb* and ΔE, and incisal > body > cervical for Δa* and ΔL*, and this may reflect the TDS's ability to promote the penetration of H2O2 to intrinsic stain sites
Measuring & modeling of concentrated settling suspensions using electrical impedance tomography
No full textApplied Science
Simulation of slurry transport through a horizontal pipe
No full textThis final report for my Masters Degree in Chemical Engineering describes a research project on slurry transport. A mathematical simulation model of the transport of slurries in a horizontal pipe is given, as well as its evaluation by means of measurements conducted in a horizontal pipe. This report deals with the problem of modelling a concentrated solid/liquid flow in a circular horizontal pipe. Particle concentration profiles were calculated with use of a settling-dispersion model. This model contains a dispersion coefficient which is a lumped parameter. This parameter contains the particle-particle interactions and particle-fluid interactions. The settling-dispersion model lacks the formation of a layer of solids at the bottom of the pipe. My report introduces a computer program that combines the formation of the layer with the settling-dispersion model. The program has been written in FORTRAN using the finite element package SEPRAN. Experiments were carried out with a sand/water slurry in a hydraulic circuit, to measure how the layer builds up. The height of the settled layer is on the one hand a function of the particle concentration in the slurry and one the other hand the particle velocity. The measurements have been done by a fairly new non-invasive technique, called Electrical Impedance Tomography. This technique is based on differences in conductivity between the sand and water, and crosssectional images of conductivity profiles can be reconstructed from the data.Applied SciencesChemical Process TechnologyParticle Technolog
Essentials for Data Support: Training the Front Office
No full textAt the end of 2011 a Data Intelligence 4 Librarians course was developed to provide online resources and training for digital preservation practitioners, specifically library staff. Lessons learned during the first rounds of the course and developments in the Research Data Management landscape have led to a revision of the positioning, the structure and the content of the course. This paper describes both the three main drivers for the revision, the changes themselves and the lessons that can be drawn from them, after three training rounds in 2014 in the revised format under the new programmatic title of Essentials 4 Data Support.Delft University of Technolog
Synthese van butyraldehyde
No full textDocument(en) uit de collectie Chemische Procestechnologie.DelftChemTechApplied Science
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