A non-disturbing sampler for near-surface waters

A small, simple and inexpensive device is described which allows the sampling of waters with a minimum of disturbance. This is particularly important when determining near-surface profiles, for example, following a dye release.     

Comparison of LIMPET contra-rotating wells turbine with theoretical and model test predictions

The performance of the contra-rotating Wells turbine installed in the LIMPET wave power station is compared to the predicted performance from theoretical analysis and model tests. A reasonable agreement was found between the predicted and measured turbine damping characteristic, however the turbine efficiency was found to be poorly predicted. It is postulated that this is due to the unsteady nature and mal-distribution of flow through the LIMPET turbine, which were not considered in the predictions. It is suggested that the reduced performance of the contra-rotating Wells turbine makes biplane or monoplane Wells turbines with guide vanes better solutions for OWC's.     

A search for propylene oxide and glycine in Sagittarius B2 (LMH) and Orion

We have used the Mopra Telescope to search for glycine and the simple chiral molecule propylene oxide in the Sgr B2 (LMH) and Orion KL, in the 3-mm band. We have not detected either species, but have been able to put sensitive upper limits on the abundances of both molecules. The 3σ upper limits derived for glycine conformer I are  3.7 × 10¹⁴ cm⁻²  in both Orion-KL and Sgr B2 (LMH), comparable to the reported detections of conformer I by Kuan et al. However, as our values are 3σ upper limits rather than detections we conclude that this weighs against confirming the detection of Kuan et al. We find upper limits for the glycine II column density of  7.7 × 10¹² cm⁻²  in both Orion-KL and Sgr B2 (LMH), in agreement with the results of Combes et al. The results presented here show that glycine conformer II is not present in the extended gas at the levels detected by Kuan et al. for conformer I. Our ATCA results have ruled out the detection of glycine (both conformers I and II) in the compact hot core of the LMH at the levels reported, so we conclude that it is unlikely that Kuan et al. have detected glycine in either Sgr B2 or Orion-KL. We find upper limits for propylene oxide abundance of  3.0 × 10¹⁴ cm⁻²  in Orion-KL and  6.7 × 10¹⁴ cm⁻²  in Sgr B2 (LMH). We have detected fourteen features in Sgr B2 and four features in Orion-KL which have not previously been reported in the interstellar medium, but have not been able to plausibly assign these transitions to any carrier.     

Applying a science-forward approach to groundwater regulatory design

Hydrogeology Journal - Groundwater sustainability is challenged by the difference between legal and scientific understanding of groundwater, as well as the lack of focused attention to regulatory...     

The decay of coastal forts in southeast Brazil and its implications for the conservation of colonial built heritage

The 500th anniversary of European arrival in Brazil was celebrated in 2000 and highlighted the need to review the condition of the countrys remaining colonial built heritage. This revision is particularly apposite in the adjacent cities of Rio de Janeiro and Niterói, where the heritage that survived twentieth century reconstruction has done so largely because of ownership by the church or military. However, whilst this may have protected buildings from demolition, detailed fabric can be neglected or abused. This paper investigates this possibility through an examination of two forts, built primarily of local augen gneiss, that guard the entrance to Guanabara Bay. Natural outcrops exposed to the same humid sub-tropical maritime environment show that this rock is susceptible to slow disaggregation through salt weathering. Surveys suggest that stonework in the forts that is sheltered from rainwash is heavily loaded with salt and has passed a threshold, wherein stresses accumulated over centuries of apparent stability, combined with the effects of a more recent increase in atmospheric pollution and apparently inappropriate intervention (re-pointing), have triggered rapid breakdown that requires immediate intervention.     

Monitoring urban growth on the European side of the Istanbul metropolitan area: A case study

Istanbul is the largest city in Turkey with an area of around 5750 km² and a population of around 10.8 M (2000). In 1980, the population was only around 4.7 M and so has more than doubled in only 2 decades. In 2000, around 65% of the population were living on the European side of the city with its large industrial/commercial and trade centres. The population is increasing as a result of both births exceeding deaths and mass immigration. Consequently, planned and unplanned housing are increasing while green areas are decreasing in area. Monitoring urban growth will enable the Municipality of Istanbul to better manage this complex urban area.     

Does the fine structure constant vary? A detailed investigation into systematic effects

We have previously presented 5.7 σ evidence for a smaller αat redshifts 0.2 < z_abs < 3.7 from a sample of 128 Keck/HIRES quasar absorption systems: Δα/α = (-0.57 ± 0.10) x10^-5. A non-zero <Δα/α manifests itself as a distinct pattern of shifts in the measured absorption line wavelengths. The statistical error is now small: we do detect small line shifts in the HIRES data. Whether these shifts are due to systematic errors or due to real variation in α is now the central question. Here we summarize the two potentially most important systematic effects: atmospheric dispersion and isotopic abundance evolution. Previously, these have been difficult to quantify/model but here we find that neither of them can explain our results. Furthermore, the HIRES spectra themselves contain no evidence for these effects. Independent measurements of Δα/α with a different telescope and spectrograph are now crucial if we are to rule out or confirm the present evidence for a variable α. This revised version was published online in July 2006 with corrections to the Cover Date.