Pyrolysis of brominated feedstock plastic in a fluidised bed reactor

Fire retarded high impact polystyrene has been pyrolysed using a fluidised bed reactor with a sand bed. The yield and composition of the products have been investigated in relation to fluidised bed temperature. The bromine distribution between the products and a detailed analysis of the oils using GC-FID/ECD, GC-MS, FT-ir, and size exclusion chromatography has been carried out. It was found that the majority of the bromine transfers to the pyrolysis oil and the antimony was detected in both the oil and the char. Oil made up over 89.9% of the pyrolysis products. Over 30% of the oil consisted of benzene, toluene, ethylbenzene, styrene and cumene. The pyrolysis gases were mainly hydrocarbons in the C1-C4 range but some HBr and Br2 was detected

A novel function for the Caenorhabditis elegans torsin OOC-5 in nucleoporin localization and nuclear import.

Torsin proteins are AAA+ ATPases that localize to the endoplasmic reticular/nuclear envelope (ER/NE) lumen. A mutation that markedly impairs torsinA function causes the CNS disorder DYT1 dystonia. Abnormalities of NE membranes have been linked to torsinA loss of function and the pathogenesis of DYT1 dystonia, leading us to investigate the role of the Caenorhabditis elegans torsinA homologue OOC-5 at the NE. We report a novel role for torsin in nuclear pore biology. In ooc-5-mutant germ cell nuclei, nucleoporins (Nups) were mislocalized in large plaques beginning at meiotic entry and persisted throughout meiosis. Moreover, the KASH protein ZYG-12 was mislocalized in ooc-5 gonads. Nups were mislocalized in adult intestinal nuclei and in embryos from mutant mothers. EM analysis revealed vesicle-like structures in the perinuclear space of intestinal and germ cell nuclei, similar to defects reported in torsin-mutant flies and mice. Consistent with a functional disruption of Nups, ooc-5-mutant embryos displayed impaired nuclear import kinetics, although the nuclear pore-size exclusion barrier was maintained. Our data are the first to demonstrate a requirement for a torsin for normal Nup localization and function and suggest that these functions are likely conserved

Fast pyrolysis of halogenated plastics recovered from waste computers

The disposal of waste computers is an issue that is gaining increasing interest around the world. In this paper, results from the fast pyrolysis in a fluidized bed reactor of three different waste computer monitor casings composed of mainly acrylonitrile-butadiene-styrene (ABS) copolymer and two different waste computer body casings composed of mostly poly(vinyl chloride) (PVC) type polymers are presented. Preliminary characterization of the waste plastics was investigated using coupled thermogravimetric analysis-Fourier transform infrared spectrometry (TGA-FT-IR). The results showed that the plastics decomposed in two stages. For the ABS-containing monitor casings, aromatic and aliphatic material were released in the first and second stages. The PVC-containing computer body casing samples showed a first-stage evolution of HCl and a second stage evolution of aromatic and aliphatic material and further HCl. In addition, each of the five plastics was fast-pyrolyzed in a laboratory-scale fluidized bed reactor at 500 °C. The fluidized bed pyrolysis led to the conversion of most of the plastics to pyrolysis oil, although the two PVC computer body cases produced large quantities of HCl. The pyrolysis oils were characterized by GC-MS and it was found that they were chemically very heterogeneous and contained a wide range of aliphatic, aromatic, halogenated, oxygenated, and nitrogenated compounds

Separation and recovery of materials from scrap printed circuit boards

Printed circuit boards from waste computers, televisions, and mobile phones were pyrolysed in a fixed bed reactor with the aim of separating and recovering the organic and metallic materials. A selection of printed circuit boards from each of the three waste classes was pyrolysed at 800°C and the pyrolysis products were analysed using GC-FID, GC-TCD, GC-MS, GC-ECD, ICP-MS, and SEM-EDX. The pyrolysis oils contained high concentrations of phenol, 4-(1-methylethyl)phenol, and p-hydroxyphenol, as well as bisphenol A, tetrabromobisphenol A, methyl phenols, and bromophenols. The pyrolysis oils also contained significant concentrations of organo – phosphate compounds and a number of tetrabromobisphenol A pyrolysis products were also identified. The pyrolysis residues were very fragile and the organic, glass fibre, and metallic fractions could easily be separated and the electrical components could easily be removed from the remains of the printed circuit boards. The ash in the residue mainly consisted of copper, calcium, iron, nickel, zinc, and aluminium, as well as lower concentrations of valuable metals such as gallium, bismuth, silver, and gold, silver was present in particularly high concentrations. Many other metals were also identified in the ash by ICP-MS and SEM EDX. The pyrolysis gases mainly consisted of CO2 and CO but all of the C1 – C4 alkanes and alkenes were present, as were some inorganic halogens

Software for Alignment of Segments of a Telescope Mirror

The Segment Alignment Maintenance System (SAMS) software is designed to maintain the overall focus and figure of the large segmented primary mirror of the Hobby-Eberly Telescope. This software reads measurements made by sensors attached to the segments of the primary mirror and from these measurements computes optimal control values to send to actuators that move the mirror segments

Communications Biophysics

Contains reports on four research projects.U.S. Air Force under Contract AF19(604)-411

Sexual identity fluidity, identity management stress, and depression among sexual minority adolescents

Introduction Sexual identity is mutable and evolving, particularly during adolescence. Sexual identity fluidity could be stressful for some adolescents and may differ by birth-sex. Evidence suggests chronic stress can lead to negative mental health outcomes. However, it is unknown if these two processes (stress and depression) differ by sexual identity fluidity.MethodsThis paper studied time-sequential associations between identity management stress and depression over time by sexual identity fluidity, in a national longitudinal data from sexual minority adolescents (SMA) aged 14–17 years using a multigroup autoregressive cross-lagged model (n = 1077). Results In the sample, 40% of SMA reported at least one change in sexual identity over 18-month period. Greater number of cisgender females reported sexual identity fluidity compared to their male counterparts (46.9% vs. 26.6%). A temporal cross-lagged effect was reported between depression and identity management stress among cisgender females who reported fluidity in sexual identity; and no cross-lagged effect was reported among those females who did not report fluidity. However, among cisgender male sample depression predicted subsequent identity management stress, irrespective of their change sexual identity fluidity status. Conclusion Public health programs and practice must be responsive to the sexual identity fluidity processes among adolescents, with particular attention to minority stress and depression. In addition, our results indicate that sexual identity development and fluidity processes differ between cisgender females and males; and the nuances associated with these processes of change need further investigation