Kaolinisation of granite in an urban environment

Under natural acid and wet conditions, one of the main weathering processes affecting granitic rocks is the kaolinisation of Na, Ca and K-feldspar minerals by H₂O + CO₂ attack. We here report the occurrence of authigenic kaolinite on the surface of an eighteenth century granitic monument covered with sulphate-rich weathering patinas. We suggest that, in humid mesothermic climates, anthropogenically derived gaseous SO₂ from air pollution is responsible for accelerated kaolinisation of feldspars in an urban environment; SO₂ from air pollution thus plays a dual role in the weathering of silicate rocks being responsible for the well known sulphation of Ca-bearing materials leading to the formation of sulphate salts such as gypsum as well as the weathering of feldspar minerals to kaolinite. The kaolinisation reaction weakens the granite microfabric leading to enhanced decay of the building stone.     

Is Japan's whaling humane?

Video taken by Greenpeace of whaling by the Japanese whaling fleet in the Southern Ocean provided a unique opportunity to obtain quantitative data relevant to the welfare aspects of the killing of whales. Catches of 16 individual Antarctic minke whales (Balaenoptera bonaerensis) were analysed and in two of these asphyxiation appeared the most likely cause of death. Fewer than one in five whales were killed instantaneously and the average time to death for the remaining whales was around 10 min. The presence of Greenpeace did not result in a reduced accuracy of harpoon shots when compared with previous studies.     

Benchmarking for fisheries governance

The paper develops a benchmarking framework to improve fisheries governance and promote resilient ecosystems and profitable fisheries. The benchmarking includes five key components: accountability, transparency, incentives, risk assessment and management; and adaptability. Collectively, these factors provide a framework to benchmark and improve fisheries governance. Initial findings from benchmarking in two of Australia's Commonwealth fisheries indicate that the framework provides an important tool to help overcome the underlying causes of unsustainability in capture fisheries—poor and/or ineffective fisheries governance.     

No more blind dates with calcite:Fluid-flow vs.fault-slip along the O(c)kov thrust,Prague Basin

Dating of fracture-filling calcite with U-Pb geochronology is becoming a rapidly adopted technique for determin-ing the absolute timing of brittle deformation i...     

The hydrology of inland valleys in the sub‐humid zone of West Africa: rainfall‐runoff processes in the M'bé experimental watershed

Inland valleys with wet lowlands are an important water source for farming communities in the sub‐humid zone of West Africa. An inland valley and surrounding contributing watershed area located in the sub‐humid zone near M'bé in central Côte d'Ivoire was instrumented to study surface runoff and base flow mechanisms. Four flumes at different distances down the main stream and more than 100 piezometers were installed. Measurements were taken during two rainfall seasons in 1998 and 1999. Under initial wet conditions, a typical single‐peak hydrograph was observed. Under low antecedent moisture conditions, however, runoff was characterized by a double‐peaked hydrograph. The first peak, which occurred during the storm, was caused by rain falling on the saturated valley bottom. The second peak was delayed by minutes to hours from the first peak and consisted of rain flowing via the subsurface of the hydromorphic zone that surrounds the valley bottom. The duration of the delay was a function of the water table depth in the hydromorphic zone before the storm. The volume of the second peak constituted the largest portion of the stream flow. Copyright © 2003 John Wiley & Sons, Ltd.     

Upholding labour productivity under climate change: an assessment of adaptation options

Changes in labour productivity feed through directly to national income. An external shock, like climate change, which may substantially reduce the productivity of workers is therefore a macroeconomic concern. The biophysical impact of higher temperatures on human performance is well documented. Less well understood are the wider effects of higher temperatures on the aggregate productivity of modern, diversified economies, where economic output is produced in contexts ranging from outdoor agriculture to work in air-conditioned buildings. Working conditions are at least to some extent the result of societal choices, which means that the labour productivity effects of heat can be alleviated through careful adaptation. A range of technical, regulatory/infrastructural and behavioural options are available to individuals, businesses and governments. The importance of local contexts prevents a general ranking of the available measures, but many appear cost-effective. Promising options include the optimization of working hours and passive cooling mechanisms. Climate-smart urban planning and adjustments to building design are most suitable to respond to high base temperature, while air conditioning can respond flexibly to short temperature peaks if there is sufficient cheap, reliable and clean electricity.

Key policy insights

• The effect of heat stress on labour productivity is a key economic impact of climate change, which could affect national output and workers’ income.

• Effective adaptation options exist, such as shifting working hours and cool roofs, but they require policy intervention and forward planning.

• Strategic interventions, such as climate-smart municipal design, are as important as reactive or project-level adaptations.

• Adaptation solutions to heat stress are highly context specific and need to be assessed accordingly. For example, shifting working hours could be an effective way of reducing the effect of peak temperatures, but only if there is sufficient flexibility in working patterns.

     

Study of the contact binary AK Herculis: Light-curve analysis and orbital period investigation

AK Her is a very interesting contact binary exhibiting variable lightcurves and an obvious O'Connell effect, with max I greater than max II. Inthe present work an extensive study of this system is made covering notonly its light curve analysis, but also its orbital period changes in anattempt to give a definite answer regarding the apsidal motion of AK Her.Photoelectric observations of AK Her, obtained between 1985–1987 at theNational Observatory of Athens Greece, are presented, analysed anddiscussed. The light curve analysis was made with the W-D code and thegeometric and photometric elements of the system were derived. TheO'Connell effect was faced with a two dark spot model. Moreover, theorbital period of the system was examined and two periodicities weredetected. Since the first one corresponds to the time interval for whichobservational data exist and the second was found to be half of the first,it turns out that none of them is true. Two other significant results thatcame from the present analysis are that the orbital period of AK Her doesnot follow a sinusoidal variation and that, from the times of minimumlight at primary and secondary eclipses, it seems that there is no apsidalmotion.