Production of pyroxene ceramics from the fine fraction of incinerator bottom ash.

Incinerator bottom ash (IBA) is normally processed to extract metals and the coarse mineral fraction is used as secondary aggregate. This leaves significant quantities of fine material, typically less than 4mm, that is problematic as reuse options are limited. This work demonstrates that fine IBA can be mixed with glass and transformed by milling, calcining, pressing and sintering into high density ceramics. The addition of glass aids liquid phase sintering, milling increases sintering reactivity and calcining reduces volatile loss during firing. Calcining also changes the crystalline phases present from quartz (SiO2), calcite (CaCO3), gehlenite (Ca2Al2SiO7) and hematite (Fe2O3) to diopside (CaMgSi2O6), clinoenstatite (MgSiO3) and andradite (Ca3Fe2Si3O12). Calcined powders fired at 1080°C have high green density, low shrinkage (<7%) and produce dense (2.78 g/cm(3)) ceramics that have negligible water absorption. The transformation of the problematic fraction of IBA into a raw material suitable for the manufacture of ceramic tiles for use in urban paving and other applications is demonstrated.

Evidence for the ground-state resonance of 26O.

Evidence for the ground state of the neutron-unbound nucleus (26)O was observed for the first time in the single proton-knockout reaction from a 82 MeV/u (27)F beam. Neutrons were measured in coincidence with (24)O fragments. (26)O was determined to be unbound by 150(-150)(+50) keV from the observation of low-energy neutrons. This result agrees with recent shell-model calculations based on microscopic two- and three-nucleon forces.

Simultaneous recovery of copper and degradation of 2,4-dichlorophenoxyacetic acid in aqueous systems by a combination of electrolytic and photolytic processes.

In mixed industrial effluent the presence of metal ions can retard the destruction of organic contaminants and the efficiency of recovery of the metal is reduced by the presence of the organic species. Results are presented for copper-2,4-dichlorophenoxyacetic acid (2,4-D) system in which both effects occur. An electrochemical cell alone can be used to recover copper in the pH range 1.5-4.5 but it is not capable of achieving complete disappearance of 2,4-D by anodic oxidation. A photolytic cell alone can achieve the destruction of 2,4-D at pH 3.5 but leaves copper in solution. A combined photolytic-electrochemical system using an activated carbon concentrator cathode achieves the rapid simultaneous destruction of 2,4-D and recovery of copper. Results are presented for the recovery of more than 90% copper from, and >99.9%, destruction of the organochlorine compound 2,4-D in, a solution containing 100 mg dm(-3) copper and 50 mg dm(-3) 2.4-D. The photolytic degradation of 2,4-D depends on the intensity of the UV-probe. Only 19% degradation is achieved after 8 h with the 150 W UV-probe but the corresponding value with the 400 W UV-probe is 100%. In the case of 150 W UV-probe the degradation of 2,4-D proceeds through the formation of 2,4-dichlorophenol and phenol. The concentration of these intermediates are very low in the case of 400 W UV-probe because the speed of the degradation of 2,4-D is very fast. The addition of TiO2 (1 g dm(-3)), as a semiconductor material, and H202 (1.5 g dm(-3)) as an oxidant, increases the photolytic degradation of 2,4-D.

Photocatalytic degradation of trans-cinnamic, dihydrocinnamic, trans-caffeic, and dihydrocaffeic acids and characterization of the products.

Catalysed degradation of aqueous solutions of cinnamic 1, dihydrocinnamic 2, dihydrocaffeic 3 and trans-caffeic 4 acids in the presence of (TiO2) and UV radiation and the products identified by HPLC, and after treatment with diazomethane by GC-MS have been studied. A pH range of 3 to 11 was used. The four acids, in the presence of TiO2 in the dark, underwent little degradation. Extended irradiation of all the acids in the presence of TiO2 produced complete degradation as shown by TOC measurements. Initially the volume of carbon dioxide produced rose steadily to a constant value.

Chemical kinetics of the photocatalytic degradation of trans-cinnamic, dihydrocinnamic, trans-caffeic, and dihydrocaffeic acids.

Quantitative studies of the catalysed degradation of aqueous solutions of cinnamic 1, dihydrocinnamic 2, trans-caffeic 3 and dihydrocaffeic 4 acids in the presence of TiO2 and UV radiation at pH 3 and 10 are reported. The phenolic and aliphatic unsaturated groups in caffeic acid 3 caused it to be adsorbed more strongly than the phenolic saturated acid 4, and these two acids were much more strongly adsorbed than cinnamic and hydrocinnamic acids. The kinetics of the degradation of each acid has been studied at pH 3 and 10. TIC analysis showed complete mineralisation of the acids after 9 h.

Methodology for studying oxidation of organic species in solution.

A photoreactor was developed to study products of photochemical oxidation in a wide range of organic compounds. Analysis of the products from the reactor were used to determine the extent of mineralization of the organic material, to characterize any intermediate compounds formed, and to obtain information on the decomposition mechanism. Appropriate methods for separation and characterization include LC, UV spectrophotometry, gas chromatography/mass spectrometry, total organic carbon, and total inorganic carbon. The uses of the reactor are described for the photocatalytic decomposition of phenol and of its major decomposition intermediates 1,2- and 1,4-dihydroxybenzene.

Cryopreservation of interior spruce (Picea glauca engelmanni complex) embryogenic cultures.

Embryogenic cultures of interior spruce derived from 12 full-sib families were subjected to cryopreservation, with a 97 % success rate for 357 genotypes. Analyses suggested that cryotolerance was not related to family ranking (height increment), embryogenic potential or culture dispersability in suspension, and long-term storage in or above liquid nitrogen did not affect regenerative potential. By contrast, differences in cryotolerance among cell lines appeared to be prevalent in certain families. Analysis with a DNA fingerprinting probe used for clonal identification demonstrated no evidence of somaclonal variation as a result of cryopreservation. The results of this work indicate the applicability of cryopreservation as a long-term storage strategy for spruce embryogenic cultures from a wide genetic background.

Back pain and sciatica: controlled trials of manipulation, traction, sclerosant and epidural injections.

Four treatment regimens for patients with specified combinations of low back pain and sciatica were evaluated. The largest group studied had low back pain with limited straight-leg raising (SLR) and in them the beneficial effect of manipulation in hastening pain relief was highly significant. In similar patients without limitation of SLR, the effect was of borderline significance. In all the other groups, treated patients also recovered more quickly than their controls. Traction, for patients with low back pain and sciatica, and epidural injections when a root palsy was present also produced some significant pain relief. The effect of sclerosants for back pain was less clear.

Nifedipine in the treatment of Raynaud's phenomenon in patients with systemic sclerosis.

A double-blind, placebo-controlled, cross-over trial of nifedipine 10 mg three times daily for 6 weeks, in 10 patients with Raynaud's phenomenon secondary to systemic sclerosis, is reported. A significant reduction in the duration of attacks of Raynaud's phenomenon was observed. Nifedipine therapy also reduced the number and severity of attacks of Raynaud's phenomenon and the development of new digital ulcers, and increased the digital blood flow, but none of these changes was statistically significant. No alteration in red blood cell deformability or leukocyte chemiluminescence was observed during nifedipine treatment.

A double blind trial of UK-38,485, an orally active thromboxane synthetase inhibitor, in the treatment of Raynaud's syndrome.

Ten patients with moderate to severe Raynaud's syndrome were recruited into a four week randomised double blind crossover study to compare the efficacy of UK-38,485 50 mg, a new thromboxane synthetase inhibitor with that of placebo. With the doses used there was no significant difference between the two treatment periods in the number, severity and duration of ischaemic attacks, the mean hand temperatures, forearm and digital blood flow and red blood cell rheology.