59 research outputs found
Ratios of bottom meson branching fractions involving J/psi mesons and determination of b quark fragmentation fractions
We report a measurement of the ratios of the decay rates of the B^+, B^0 and
B^0_s mesons into exclusive final states containing a J/psi meson. The final
states were selected from 19.6 pb^{-1} of p-pbar collisions recorded by the
Collider Detector at Fermilab. These data are interpreted to determine the
bquark fragmentation fractions f_u, f_d and f_s. We also determine the
branching fractions for the decay modes B^+ --> J/psi K^+, B^+ --> J/psi
K^*(892)^+, B^0 --> J/psi K^0, B^0 --> J/psi K^*(892)^0 and B_s^0 --> J/psi
phi(1020). We discuss the implications of these measurements to B meson decay
models.Comment: 40 pages with 5 figures. Submitted to Phys. Rev. D. PostScript also
available at http://www-cdf.fnal.gov/physics/pub96/cdf3609_bfrag_br_prd.p
The application of a predictive migration model for evaluating the compliance of plastic materials with European Food Regulations
A model for estimating the migration of organic substances from plastic materials into foodstuffs has been previously developed. The use of this model allows a shift away from expensive and time consuming migration analysis in foods to much simpler compositional analysis in the material. Starting with toxicologically-based specific migration values, like the over 400 specific migration limit values for organic substances listed in the European Union's Synoptic Document No. 7, the corresponding allowable maximum quantity limits of these substances in the plastic were calculated. The amount of migration that can occur depends on many different factors such as the natures of the plastic, substance and food, contact time and temperature conditions, material thickness and number of uses. These factors can result in a variety of situations which must be taken into account in the estimation of migration. The handling of the migration estimation model is demonstrated for several practical migr ation scenarios using a series of case studies
The application of a model for evaluating the compliance of plastic materials with food regulations
A model for estimating the migration of organic substances from plastic materials into foodstuffs has been previously developed. The use of this model allows a shift away from expensive and time consuming migration analysis in foods to much simpler compositional analysis in the material. Starting with toxicologically based specific migration values, like the over 400 SML values for organic substances listed in the European Union's Synoptic Document N. 7, the corresponding allowable limits (QM) of these substances in the plastic were calculated. The amount of migration that can occur depends on many different factors such as the natures of the plasic, substance and food, contact time and temperature conditions, material thickness and number of uses. These factors can result in a variety of situations wich must be taken into account in the estimation of migration. The handling of the migration estimation model is demonstrated for several practical migration scenarios using a series of ca se studies
Quantitative analysis of polymer additives by coupled SFE/SFC.
Supercritical carbon dioxide was used supercritical fluid extraction (SFE) coupled with supercritical fluid chromatography (SFC) to quantitatively analyze additives in polymers. A unique method was used to measure carbon dioxide flows at the system's outlets. Triacetine in Biopol and Irganox additives in Polypropylene were measured
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