11 research outputs found
Development of a humidifier for patient ventilation using a semi-permeable tube to minimize system condensate
Historical Review of Experimental Studies and Prediction Methods to Describe Laminar and Turbulent Shock Wave/Boundary Layer Interactions in Hypersonic Flows
Predictions of the Maximum Amplitude, Time of Occurrence, and Total Length of Solar Cycle 24
In this work we predict the maximum amplitude, its time of occurrence, and
the total length of Solar Cycle 24 by linear regression to the curvature
(second derivative) at the preceding minimum of a smoothed version of the
sunspots time series. We characterise the predictive power of the proposed
methodology in a causal manner by an incremental incorporation of past solar
cycles to the available data base. In regressing maximum cycle intensity to
curvature at the leading minimum we obtain a correlation coefficient R \approx
0.91 and for the upcoming Cycle 24 a forecast of 78 (90% confidence interval:
56 - 106). Ascent time also appears to be highly correlated to the second
derivative at the starting minimum (R \approx -0.77), predicting maximum solar
activity for October 2013 (90% confidence interval: January 2013 to September
2014). Solar Cycle 24 should come to an end by February 2020 (90% confidence
interval: January 2019 to July 2021), although in this case correlational
evidence is weaker (R \approx -0.56).Comment: Accepted in Solar Physic
Tropospheric ozone: respiratory effects and Australian air quality goals.
OBJECTIVE--To review the health effects of tropospheric ozone and discuss the implications for public health policy. DESIGN--Literature review and consultation with scientists in Australia and overseas. Papers in English or with English language abstracts were identified by Medline search from the international peer reviewed published reports. Those from the period 1980-93 were read systematically but selected earlier papers were also considered. Reports on ozone exposures were obtained from environmental agencies in the region. RESULTS--Exposure to ozone at concentrations below the current Australian air quality goal (0.12 ppm averaged over one hour) may cause impaired respiratory function. Inflammatory changes in the small airways and respiratory symptoms result from moderate to heavy exercise in the presence of ozone at levels of 0.08-0.12 ppm. The changes in respiratory function due to ozone are short lived, vary with the duration of exposure, may be modified by levels of other pollutants (such as sulphur dioxide and particulates), and differ appreciably between individuals. Bronchial lavage studies indicate that inflammation and other pathological changes may occur in the airways before reductions in air flow are detectable, and persist after respiratory function has returned to normal. It is not known whether exposures to ozone at low levels (0.08-0.12 ppm) cause lasting damage to the lung or, if such damage does occur, whether it is functionally significant. At present, it is not possible to identify confidently population subgroups with heightened susceptibility to ozone. People with asthma may be more susceptible to the effects of ozone than the general population but the evidence is not consistent. Recent reports suggest that ozone increases airway reactivity on subsequent challenge with allergens and other irritants. Animal studies are consistent with the findings in human populations. CONCLUSION--A new one hour air quality ozone goal of 0.08 ppm for Australia, and the introduction of a four hour goal of 0.06 ppm are recommended on health grounds
Solar Weather Event Modelling and Prediction
Key drivers of solar weather and mid-term solar weather are reviewed by considering
a selection of relevant physics- and statistics-based scientific models as well as aselection of related prediction models, in order to provide an updated operational scenario
for space weather applications. The characteristics and outcomes of the considered scientific
and prediction models indicate that they only partially cope with the complex nature of solar
activity for the lack of a detailed knowledge of the underlying physics. This is indicated by
the fact that, on one hand, scientific models based on chaos theory and non-linear dynamics
reproduce better the observed features, and, on the other hand, that prediction models
based on statistics and artificial neural networks perform better. To date, the solar weather
prediction success at most time and spatial scales is far from being satisfactory, but the forthcoming
ground- and space-based high-resolution observations can add fundamental tiles to
the modelling and predicting frameworks as well as the application of advanced mathematical
approaches in the analysis of diachronic solar observations, that are a must to provide
comprehensive and homogeneous data sets.peerReviewe