Surface and microanalytical studies of whetlerite charcoals: 1. Effects of aging

ASC Whetlerite charcoals impregnated with copper and chromium have been studied by several surface and microanalytical techniques to determine the effects of aging on the composition and microstructure. X-ray photoelectron spectroscopic (XPS) studies of absorbers not deliberately aged, showed that most of copper on the inside of each particle was present as Cu(I). Transmission microscopy showed that some of this copper is present as crystallites with diameters up to 0.1 μm. Natural or artificial aging in a humid atmosphere resulted in the number and size of such crystallites and a migration of some of the copper impregnants to the outer surface of the particle, where it is bonded largely as Cu(OH)₂. Chromium is present in the adsorber in both Cr(III) and Cr(VI) oxidation states and it undergoes little change during aging.     

Mobile Ferroelastic Domain Walls in Nanocrystalline PZT Films: the Direct Piezoelectric Effect

Ferroelastic (90°) domain wall motion occurs readily in bulk samples of displacive ferroelectrics such as Pb(Zr,Ti)O₃ (PZT), dictating critical piezoelectric, dielectric, and polarization switching properties. Many prior studies have used converse piezoelectric measurements to probe the dynamics of ferroelastic domains in thin films; however, such experiments are strongly influenced by the mechanical clamping effect of the substrate, which inhibits electric field‐induced 90° domain wall motion. Nevertheless, these observations raise a tantalizing question: Does the application of mechanical stress, rather than electric field, result in an entirely different response in thin films? Here we report biaxial stress‐driven crystallographic reorientation of (100)/(001) textured, 70 nm thick Pb(Zr_0.25Ti_0.75)O₃ films via 90° domain wall motion, measured in situ by both x‐ray diffraction and piezoforce microscopy. Visual evidence of nanoscale mechanisms that underlie the direct piezoelectric effect is shown. Mobile 90° domain walls effect complete orientation switching in the grains in which they operate, without apparent wall pinning, indicating that bulk‐like ferroelastic behavior can extend to nanocrystalline films in the absence of substrate clamping.     

Real-time monitoring of benzene, toluene, and p-xylene in a photoreaction chamber with a tunable mid-infrared laser and ultraviolet differential optical absorption spectroscopy

We describe the implementation of a mid-infrared laser-based trace gas sensor with a photoreaction chamber, used for reproducing chemical transformations of benzene, toluene, and p-xylene (BTX) gases that may occur in the atmosphere. The system performance was assessed in the presence of photoreaction products including aerosol particles. A mid-infrared external cavity quantum cascade laser (EC-QCL)-tunable from 9.41-9.88?μm (1012-1063?cm(-1))-was used to monitor gas phase concentrations of BTX simultaneously and in real time during chemical processing of these compounds with hydroxyl radicals in a photoreaction chamber. Results are compared to concurrent measurements using ultraviolet differential optical absorption spectroscopy (UV DOAS). The EC-QCL based system provides quantitation limits of approximately 200, 200, and 600 parts in 10(9) (ppb) for benzene, toluene, and p-xylene, respectively, which represents a significant improvement over our previous work with this laser system. Correspondingly, we observe the best agreement between the EC-QCL measurements and the UV DOAS measurements with benzene, followed by toluene, then p-xylene. Although BTX gas-detection limits are not as low for the EC-QCL system as for UV DOAS, an unidentified by-product of the photoreactions was observed with the EC-QCL, but not with the UV DOAS system.     

Physicochemical and microbiological quality of water from a pilot domestic rainwater harvesting facility in Ireland

Dublin Institute of Technology personnel were commissioned in 2005 by the Department of Environment, Heritage and Local Government in Ireland to assess the feasibility of utilizing harvested rainwater to replace treated mains water, for nonpotable uses. A pilot project was set up. The project involved the design, installation, commissioning and monitoring of rainwater harvesting facilities in a rural housing development. A monitoring programme was carried out to examine the physicochemical and microbiological quality of the harvested rainwater. Harvested rainwater was sampled monthly and tested. Analysis of the harvested rainwater quality showed a consistently high quality of raw water in general compliance with the requirements of the European Communities (Quality of Bathing Water) Regulations for 100% of samples and the European Communities (Drinking Water) Regulations, 2007 for 37% of sampling dates.     

Pertussis vaccines: past, present and future in Australia

In August 1997, a workshop was convened by the National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases to consider current issues in the use of pertussis vaccines and implications for the Australian immunisation schedule. Topics covered included the history, efficacy and reactogenicity of whole-cell and acellular vaccines and vaccine schedules. Acellular pertussis vaccine is preferred by the National Health and Medical Research Council for the primary course as well as the 18 month and 4-5 year old childhood doses. At the time of the workshop, a 3-component acellular vaccine (DTPa) had been approved (licensed) in Australia for all doses in the childhood schedule. It was the first vaccine subject to a cost-effectiveness evaluation under the new vaccine funding arrangements. Issues considered in the evaluation of the cost-effectiveness of the vaccine were discussed. These included comparative efficacy, adverse events and compliance, and the question of community as well as individual benefit from the use of the vaccine.     

Continuous Wrapping Tantalum Barriers for Internal-Tin Nb3Sn Multi-Filamentary Wires

A process “continuous wrapping tantalum barrier” has been developing and investigated in this paper. By eliminating the need for inserting expensive tantalum tube, barrier is applied to unlimited piece length prior restack. A tantalum barrier with 20% overlap was wrapped onto subelements. Then 18-filament Nb₃Sn plus 1 copper core restack billet was successfully drawn down to wire with 0.84-mm diameter. The longitudinal and cross-sectional images revealed most of barriers were continuous and intact but some disrupted. So, we are still working on the optimization of manufacturing process.     

Uteroplacental vascular involvement in recurrent spontaneous abortion

In the present study, we assessed the ability of increasing doses of intranasal calcitonin to suppress urinary deoxypyridinoline cross-link (DPD), a specific biochemical marker of bone resorption, in early postmenopausal women. Subjects consisted of 30 healthy Thai women within 5 years of postmenopause, randomly assigned to 50, 100, or 200 IU of intranasal calcitonin 5 days/week for 3 months. Calcium supplementation by calcium carbonate capsules at 750 mg of elemental calcium per day was given to all subjects. Twenty four-hour urine for DPD and creatinine assays was collected at baseline, 1 month, and 3 months after treatment. All DPD values were corrected with urinary creatinine before analyses. Data were expressed as mean +/- SEM. DPD decreased significantly 1 month after intranasal calcitonin treatment (P < 0.01). However, at 3 months, DPD increased when compared with the values at 1 month (P < 0.01), suggesting that there may be a reduction in the suppression of bone resorption after prolonged calcitonin therapy. Using a stepwise multiple regression model to address whether dosage and DPD at baseline influence the response to intranasal calcitonin, it was found that DPD suppression after intranasal calcitonin was not related to dosage but was strongly associated with baseline DPD (P < 0.0001). Suppression of bone resorption in early postmenopausal women by intranasal calcitonin is determined more by the state of bone turnover at baseline than the dosage of calcitonin.