8 documents found, page 1 of 1
Reflectance and fluorescence characteristics of PTFE coated with TPB at visible...
Haefner, J.; Fahs, A.; Ho, J.; Stanford, C.; Guenette, R.; Adams, C.; Almazán, H.; Álvarez, V.; Aparicio, B.; Aranburu, A.I.; Arazi, L.; Arnquist, I.J.Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. In noble element systems, it is often coated with tetraphenyl butadiene (TPB) to allow detection of vacuum ultraviolet scintillation light. In this work this dependence is investigated for PTFE coated with TPB in air for light of wavelengths of 200 nm, 260 nm, and 450 nm. Th...
A compact dication source for Ba2+ tagging and heavy metal ion sensor development
Navarro, K.E.; Baeza-Rubio, J.; Boyd, M.; Foss, F.W.; Giri, S.; Jones, B.J.P.; Miller, R.L.; Nygren, D.R.; Samaniego, F.J.; Stogsdill, K.We present a tunable metal ion beam that delivers controllable ion currents in the picoamp range for testing of dry-phase ion sensors. Ion beams are formed by sequential atomic evaporation and single or multiple electron impact ionization, followed by acceleration into a sensing region. Controllability of the ionic charge state is achieved through tuning of electrode potentials that influence the retention time...
Relationship between solubility of freeze-dried skim milk and death of freeze-d...
Carvalho, A. Sofia; Silva, Joana; Ho, P.; Teixeira, Paula; Malcata, F. X.; Gibbs, P.To elucidate the relationship between death of freeze-dried cells of Lactobacillus bulgaricus during storage and decrease in powder solubility, the effect of milk precipitation during rehydration of freeze-dried Lb. delbrueckiissp. bulgaricus upon death of these cells throughout storage, via addition of various carbohydrates to the drying medium was studied. The degree of survival of freeze-dried Lb. bulgaricus...
Variability in quality of white and green beans during in-pack sterilization
Ávila, I.M.L.B.; Martins, R.C.; Ho, P.; Hendrickx, M.; Silva, C. L. M.Non-uniformity in process quality was investigated during in-pack thermal sterilization of food products. This was accomplished through the combined application of the Monte Carlo procedure and a reliable mathematical method for process evaluation. Despite the large coefficients of variation found, the optimum quality process could be designed. The influence of the statistical variability of heating rate index ...
Effects of addition of sucrose and salt, and of starvation upon thermotolerance...
Carvalho, A. S.; Silva, J.; Ho, P.; Teixeira, P.; Malcata, F. X.; Gibbs, P.Increased survival of freeze-dried cells of Lactobacillus bulgaricus was observed when the drying medium was supplemented with sucrose; however, the magnitude of such protection was dependent on the growth medium used. Supplementing the growth medium with NaCl markedly increased survival of dried cells, and only a small effect was exerted by the composition of the drying medium or prior to starvation of cells. ...
Effect of various growth media upon survival during storage of freeze-dried Ent...
Carvalho, A.S.; Silva, J.; Ho, P.; Teixeira, P.; Malcata, F. X.; Gibbs, P.The effects of three different growth media (MRS, M17 and Lee’s) on survival during freeze-drying and subsequent storage of six strains of Enterococcus faecalis and two strains of E. durans were investigated. Methods and Results: Distinct Enterococcus spp. strains were grown on M17, MRS and Lee’s broth, freeze-dried and stored at 20 C in air under darkness. At regular intervals throughout storage, freeze-dried ...
Multiple imputation and maximum likelihood principal component analysis of inco...
Ho, P.; Silva, M. C. M.; Hogg, T. A.A multivariate data matrix containing a number of missing values was obtained from a study on the changes in colour and phenolic composition during the ageing of port. Two approaches were taken in the analysis of the data. The first involved the use of multiple imputation (MI) followed by principal components analysis (PCA). The second examined the use of maximum likelihood principal component analysis (MLPCA)....
Application of a liquid chromatographic method for the determination of phenoli...
Ho, P.; Hogg, Tim; Silva, M.C.M.Fortified wines which suffer extended periods of wood ageing develop characteristics which in many cases define the product. An important component of this style is contributed by the specific phenolic compounds and furans which are either extracted from the wood or formed during the barrel ageing process. An HPLC method is presented here for the determination of phenolic compounds and furans in wood aged forti...