Liquid flame spray for generating metal and metal oxide nanoparticle test aerosol.

A flame-based method for generating nanoparticles with production rate in the order of g/min is presented to be used in a variety of applied studies concerning nanoparticle measurements and toxicological tests. In this study, ferric oxide, titanium dioxide, and silver nanoparticles were produced by this technique, as an example of the variety of producible compounds, and number and surface area were measured by state-of-art aerosol instruments. In the primary experiments of this study, the generator was used in a conventional way, in a fume cupboard, and the aerosol was measured from the exhaust duct of the cupboard. It has been shown that this steady, turbulent flame generator is also suitable for producing high-concentration aerosols in a wider concept. The generated aerosol was measured by variety of aerosol instrumentation to show the applicability of the generator. When using the generator intentionally as a source of aerosol in the flame processing room, mean nanoparticle sizes of 5-60 nm and active surface area concentration ranges of 1-10,000 microm(2)/cm(3) were covered for the room aerosol.

[Retrospective analysis of falls in an inpatient rehabilitation centre for rheumatic and orthopaedic diseases]. / Retrospektive Analyse von Stürzen und deren Ursachen in einem stationären Rehabilitationszentrum für Patienten mit Erkrankungen des Stütz- und Bewegungsapparates.

AIM: To analyse the frequency and circumstances of falls in an inpatient rehabilitation centre. METHODS: In a survey all falls reported to the Austrian accident insurance carrier were analysed and external circumstances of falls were evaluated. The survey covers a period of 64 months (Jan 2000 to April 2005): 10 820 inpatients (234 502 patient days); mean age 52.8 years; 1,252 patients aged >/= 70 years; 47 % male, 53 % female. RESULTS: Of 223 accidents registered, 140 (62.8 %) were falls. Of these, 17 patients had to be referred to a surgical unit for further treatment. In total, 1.29 % of all patients fell during their stay (with report to the accident insurance carrier), 0.16 % suffered major injuries from falls (with referral to surgical unit). Females fell more frequently than males. 39 % of the falls were associated with physical therapy. Most falls occurred in daytime. The location in the centre or the day of week showed no major influence on the frequency of falls. Falls occurred slightly more often in the first part of the three-week inpatient stay. CONCLUSION: The high total number of falls shows that falls are important in an inpatient rehabilitation centre for rheumatic and orthopaedic diseases. The analysis did not reveal any special location inside the rehabilitation centre with an increased risk of falls calling for urgent interventions. The active and activating physical therapies do not seem to increase the number of falls significantly.

The influence of an electrostatic precipitator and a mechanical filter on Rn decay products.

In the present work the effect of an HEPA filter and an electrostatic precipitator on the behaviour of Rn decay products has been studied in laboratory conditions. Both filters were found to decrease the equilibrium factor of progeny and increase the unattached fraction of decay products. In a clean air they also decreased the activity of unattached progeny. An electrostatic precipitator was found to produce condensation nuclei which were observable when no other particle sources were present. The ozone produced by the corona discharge of the filter probably has a great effect on the production of these submicron particles. The impurities of the air were found to grow the particles and thus their influence on the behaviour of Rn decay products became in some cases significant.

The control of radon progeny by air treatment devices.

The effect of air treatment devices on the behaviour of radon decay products has been studied in laboratory conditions. An HEPA filter and an electrostatic precipitator were used. Both of the filters were found to decrease the equilibrium factor of daughters and increase the unattached fraction of decay products. In a clean air they also decreased the activity of unattached daughters. The effect of the devices on the health risk caused by radon progeny was estimated by dosimetric calculations. The results corresponding to different models show considerable discrepancy, mainly due to different assumptions about the influence of unattached decay products on the dose.