Metakaolin as a radon retardant from concrete

Granite aggregates are known to be the radon source in concrete. Recently, metakaolin has been introduced as a partial substitution of Portland cement to produce high strength concrete. It can effectively reduce the porosity of both the matrix and the aggregate/paste transition zone, which suggests its ability to retard radon emission from concrete aggregates. In the present work, radon exhalation rates from concrete cubes substituted with metakaolin were measured using charcoal canisters and gamma spectroscopy, and were considerably lower than those from normal concrete, by about 30%. The indoor radon concentration reduction is estimated as approximately 9 Bq m(-3) calculated using a room model, causing a 30% reduction in the indoor radon concentration and the corresponding radon dose. Therefore, metakaolin is a simple material to reduce the indoor radon concentration and the radon dose.     

Health effects of residential radon: a European perspective at the end of 2002

Surveys of indoor radon concentrations, when taken together with estimates of the risk of lung cancer from studies in miners of uranium and other hard rocks, suggest that residential radon is responsible for many thousands of deaths from lung cancer each year in Europe. The vast majority of these deaths are likely to occur in individuals who also smoke cigarettes. Because of the skewed nature of the distribution of the indoor radon concentrations in most populations, most of the deaths will occur in individuals who are exposed at moderate rather than at very high radon concentrations. In order to enable appropriate policies to be developed for managing the consequences of exposure to radon, more reliable estimates of the risk of lung cancer resulting from it are needed. To achieve this, a European Collaborative Group on Residential Radon and Lung Cancer was initiated and its findings should be published in 2004.     

Personal radon dosimetry from eyeglass lenses

Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosemeters. Samples of such lenses have been obtained, etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration, and with a uranium-based source of alpha particles as a convenient secondary standard. With one exception natural, environmental (fossil) track densities ranged from less than 3,000 to nearly 70,000 per cm2 for eyeglasses that had been worn for various times from one to nearly five years. Average radon concentrations to which those wearers were exposed are inferred to be in the range 14 to 130 Bq x m(-3) (0.4 to 3.5 pCi x l(-1)). A protocol for consistent, meaningful readout is derived and used. In the exceptional case the fossil track density was 1,780,000 cm(-2) and the inferred (24 h) average radon concentration was 6500 Bq x m(-3) (175 pCi x l(-1)) for a worker at an inactive uranium mine that is used for therapy.     

Bio-kinetics of radon ingested from drinking water

Previous studies have identified the stomach as the most significant organ for the dose from ingested radon. An important factor in dosimetric modelling is the rate of radon loss from the stomach. In the present study, two subjects who ingested radon-rich water were measured using a NaI(Tl) detector fixed over the stomach. The counting rates for 214Pb and 214Bi peak regions were plotted as a function of time after ingestion. These data were interpreted using a compartment model that expressed biokinetics of radon and its progeny. The model was fitted to the experimental data by changing biokinetic parameters such as the rate of radon loss from the stomach. Previous models for dosimetric purposes often assumed that the half-time for radon loss from the stomach is below 20 min. The present results, however, suggest that a part of radon stayed longer in the stomach than expected in the previous models.     

The rivalry between Bernini and Borromini from a scientometric perspective

Scientometrics - From a historical point of view, Rome and especially the University of La Sapienza, are closely linked to two geniuses of Baroque art: Bernini and Borromini. In this study, we...     

Comparison of urinary excretion of radon from the human body before and after radon bath therapy

Theoretically, the human body absorbs radon through the lungs and the skin and excretes it through the lungs and the excretory organs during radon bath therapy. To check this theory, the radon concentrations in urine samples were compared before and after radon bath therapy. During the therapy, the geometric mean (GM) and the geometric standard deviation of the radon concentration in air and in the bath water were 979 Bq m(-3), 1.58 and 73.6 Bq dm(-3), 1.1, respectively. Since radon was detected in each urine sample (GM around 3.0 Bq dm(-3)), urinary excretion of radon was confirmed. The results of this study can neither reject nor confirm the hypothesis of radon absorption through the skin. A 15 times higher increment of inhaled radon level did not cause significant changes in radon of urine samples.     

The weekly measurement deviations of indoor radon concentration from the annual arithmetic mean

The difference between weekly measurements and the annual arithmetic mean of radon indoor concentration CRn,Indoor was studied in the Czech Republic. The deviations were analysed for 1537 weekly measurements which were consecutively obtained in 29 rooms over a period of 1 year and the annual arithmetic mean was calculated for each particular room. The relationship of the deviations to three meteorological parameters (i.e. outside temperature, atmospheric pressure, and weekly rainfall) and to the sequential number of a calendar week was studied. The effect of atmospheric pressure and weekly rainfall was not significant. The deviation between a weekly measurement and the annual arithmetic mean depended significantly on outside weekly average temperatures. If the average outside weekly temperature was below 10 degrees C, the radon concentration was systematically higher than that of the annual arithmetic mean. The deviation variability was lower up to a temperature of 10 degrees C. If the weekly average outdoor temperature was higher than 10 degrees C, the uncertainty of a weekly measurement of radon concentration was also higher.     

Operationalising form postponement from a decision-making perspective

Form postponement means delaying the commitment of inventory to the final configuration of a product as long as possible. Many firms today are striving to redesign their products and/or their manufacturing and supply chain processes to implement form postponement. Opportunities for form postponement, however, are sometimes lost in the companies’ production-planning processes. By focusing on the deferring of product mix decisions in the master production scheduling process, this paper shows that form postponement opportunities can be divided into two components: one whose pursuit necessarily requires product and/or transformation process redesign, the other that can be pursued by changing the sales forecasting and master production scheduling process alone. We develop an operational procedure to identify and quantify, for a given product family, all opportunities for form postponement and their two respective components. Then, we discuss and empirically illustrate how the proposed measurement procedure may support companies in changing their decision-making routines to implement form postponement. Finally, we set future research directions on form postponement suggested by our results.     

Efimov physics from a renormalization group perspective

We discuss the physics of the Efimov effect from a renormalization group viewpoint using the concept of limit cycles. Furthermore, we discuss recent experiments providing evidence for the Efimov effect in ultracold gases and its relevance for nuclear systems.     

Improving technical specifications from a risk perspective

The Technical Specifications (TSs) for a nuclear power plant is an important licensing document which defines various operational requirements or conditions. In light of the recent trends to move towards risk-based regulation, many researchers analyzed the risk impacts associated with the TS requirements, using the plant models, such as event trees or fault trees, that were developed as part of probabilistic safety assessments. This paper presents the insights gained from a review of these risk-based analyses of TSs, focussing on surveillance requirements and AOT (allowed outage time) requirements.     

Bipenalty method from a frequency domain perspective

In a recent paper, it was shown that for time domain analysis, the simultaneous use of inertial and stiffness type penalty parameters to enforce constraints was found to yield accurate and converging results without causing any stability problems. From a frequency domain perspective, this is somewhat unexpected because the solution converges from below when stiffness penalty parameters are used to model constraints, and the convergence is from above when inertial penalty parameters are used. The purpose of this paper is to explain the effect of the simultaneous use of stiffness and inertial penalty parameters on the natural frequencies of constrained systems. In this work, it is shown that if suitably tuned, the bipenalty approach works well for frequency domain analysis also, and that with two different tuned set of stiffness and inertial penalty parameters, bounded solutions to the natural frequencies of constrained systems may be obtained. The method is applicable for any linear eigenvalue problem. Copyright © 2012 John Wiley & Sons, Ltd.     

An appraisal of ecolabelling from a design perspective

This paper considers the design implications of the European ecolabelling scheme. The aims and procedures of this procedures of this product level market instrument are examined and appraised with regard to impact on product design. The paper concludes that ecolabelling, as presently defined, will have a limited affect on promoting widespreads design and provision of environmentally sensitive products. A ‘product selection model’ is therefore proposed that makes for more effective ecolabelling. This in turn is developed to provide an ‘ecodesign emphasis model’ to indicate design options that can shift products towards an optimum and sustainable ‘green’ target.     

The occurrence of farm--environmental injuries in a Swedish municipality.

The objectives of the present baseline study were to investigate work- and nonwork-related injuries in farm environments. 364 or 10% of all injuries in the study area occurred within farm environments. 174 (84%) of these were classified as work-related and 190 (52%) as home injuries. Most of the cases of farming injuries occurred during repair and maintenance work, animal care, and machine and vehicle use. The dominant types of injuries were falls, crushes, and eye injuries. Home injuries on farms accounted for 22% of all home injuries in the study area. Fourteen percent of these involved people who were not living on farms. Child injuries occurred in the home as well as in the work environment.     

Development of a radon trap device using a corona discharge

Radon is one of the noble gases, which are chemically inert and do not make any reactants under normal conditions. In this experiment we demonstrated an enigmatic reaction between radon and fluorine when a corona discharge is used as a promoter. Distinctive changes in radon concentrations were caused by the discharge and a trap efficiency of >99.5% was estimated. The mass balance between the trapped and the released radon was found to be reasonable. This indicates the existence of chemical reactions with radon. This trap phenomenon has application as a technique for reducing radon concentration in radon-contaminated air. It is possible that this technique will be applicable to other noble gases.     

The Swedish Patent Office; a fully equipped international authority

The background and evolution of the Patent Department of the Swedish Patent Office is described, through the turmoil of the late 1970s—when the PCT and the EPC came into force—to the present situation characterized by flexible management and computerization.     

掀起简约风暴的瑞典家具

北欧风格以简洁著称于世，是“极简主义”，“后现代”等风格标准的代言人，在20世纪风起云涌的“工业设计”浪潮中，北欧风格的简洁更是被推到极致，北欧家具被普遍认为是有人情味的现代家具。有些家具评论家概括为“北欧家具表现出对形式和装饰的节制，对传统价值的尊重，对天然材料的偏爱，对形式和功能的统一，对手工品质的推崇。     

Human perception of radon risk and radon mitigation: some remarks

The Radon program in the Czech Republic has a relatively long and rich history. Procedures, which enable to evaluate the risk of radon penetration from the ground, to protect new buildings, to find existing buildings with elevated indoor radon levels and to realise remedial measures in such buildings, have been developed, published and tested. In some cases, the whole system may fail due to psychological or sociological reasons. Three types of problems (conflicts) will be presented: human behaviour affecting measurement results, conflict between individual and 'all-society' points of view, interpretation of radon risk itself.