Validation of Sagnier's theory by its application to the major planets

The understanding of quantum mechanical phenomena has come to rely heavily on theory framed in terms of operators and their eigenvalue equations. This paper investigates the utility of that technique as related to the reciprocity principle in diffuse reflection. The reciprocity operator is shown to be unitary and Hermitian; hence, its eigenvectors form a complete orthonormal basis. The relevant eigenvalue is found to be infinitely degenerate. A superposition of the eigenfunctions found from solution by separation of variables is inadequate to form a general solution that can be fitted to a one-dimensional boundary condition, because the difficulty of resolving the reciprocity operator into a superposition of independent one-dimensional operators has yet to be overcome. A particular lunar application in the form of a failed prediction of limb-darkening of the full Moon from brightness versus phase illustrates this problem. A general solution is derived which fully exploits the determinative powers of the reciprocity operator as an unresolved two-dimensional operator. However, a solution based on a sum of one-dimensional operators, if possible, would be much more powerful. A close association is found between the reciprocity operator and the particle-exchange operator of quantum mechanics, which may indicate the direction for further successful exploitation of the approach based on the operational calculus.     

Alkali feldspars as a main phosphorus reservoirs in rare-metal granites: three examples from the Bohemian Massif (Czech Republic)

Phosphorus-rich alkali feldspars were found in three peraluminous highly differentiated albite-topaz-Li-mica granites in the W and S parts of the Bohemian Massif. The average contents of P₂O₅ in K-feldspars (Křížovy kámen 0.57 wt%, Homolka 0.77 wt%, and Podlesí 0.83 wt%) are higher than the average contents of P₂O₅ in albites (Křížovy kámen 0.23 wt%, Homolka 0.23 wt%, and Podlesí 0.39 wt%). The analyses of feldspars indicate that partition coefficient of phosphorus between K-feldspar and albite range from 1.5 to 2.5. Measured data in K-feldspars suggest a statistically significant difference from the Al³⁺+P⁵⁺=2 Si⁴⁺ substitution mechanism for higher phosphorus concentration. The P-content in K-feldspars from the Podlesí-granite represent the highest P-content in natural feldspar known to date (up to 2.5 wt% of P₂O₅)- It is suggested that all studied granites retained nearly all phosphorus of granitic melts and that their alkali feldspars represent major reservoirs of phosphorus.     

Potentially active volcanoes of Peru-Observations using Landsat Thematic Mapper and Space Shuttle imagery

Landsat Thematic Mapper (TM) images and Space Shuttle color photograph have been used to make a synoptic study of the volcanoes of southern Peru (14°–17° S), the northernmost portin of the Central Volcanic Zone (CVZ 14°–28° S) of the Andes. Apart from providing consistent coverage, the chief merit of the TM for this study has been the spatial resolution provided by the 30-m pixel size. The optimal 20-m resolution, variable lighting and viewing geometry, and stereo capability of the Shuttle photography provided an invaluable ancilliary data set. At the resolution available, subtle glacial-morphological features such as valley and terminal moraines can be confidently identified, and these features have been used to determine the relative ages of volcanoes. Volcanoes have been classified as potentially active if they have; (i) a well-preserved summit crater, (ii) pristine lava flow texture and morphology, (iii) flank lava flows with low albedo, and (iv) evidence of postglacial (<10 000 years) activity. Eight major volcanoes are postulated to be potentially active. Most are large, dominantly andesitic, composite cones with edifice heights of up to 2500 m; some of which threaten nearby settlements. One of them, Sabancaya, was active as recently as July 1988. Other, little-known, postglacial volcanic features include Huaynaputina, site of a major explosive rhyolitic eruption in 1600 a.d., and several fields of monogenetic scoria cones and lava flows. The active volcanic front is some 200 km east of the Peru-Chile trench, and the volcanoes lie on a trenchparallel trend oblique to the EW subduction. This narrow volcanic zone is thought to reflect the steep dip of the Nazca plate through the zone of magma generation. The break in the trend of the volcanic front in the northern extremity of the volcanic zone is thought to reflect the complexity of the crustal stress field above a major segment boundary in the subducting plate. The fields of mafic monogenetic centers also occur in this region. In comparison with the southern part of the CVZ, the general paucity of older volcanic edifices north of 17° S suggests a more recent onset of volcanism north of this latitude probably resulting from the oblique subduction of the Nazca ridge and the consequent northward migration of its intersection with the Pere-Chile trench. This, coupled with the lack of any large silicic caldera systems and youthful dacite domes, like those found further south, suggest that there are real differences between the volcanic evolution of different parts of the CVZ.     

Forecasting El Niño and La Niña events using decision tree classifier

Theoretical and Applied Climatology - The El Niño-Southern Oscillation (ENSO) phenomenon affects the global climate by changing temperature and precipitation patterns mainly in tropical...     

Correction to: Observational Investigation of the Statistical Properties of Surface-Layer Turbulence in a Suburban Area of São Paulo,Brazil: Objective Analysis of Scaling-Parameter Accuracy and Uncertainties

Boundary-Layer Meteorology -     

A methodology for defining homogeneous water bodies in estuaries – Application to the transitional systems of the EU Water Framework Directive

A methodology is developed and tested for division of estuarine and coastal systems into water bodies for monitoring and management purposes. This division is often implicit in the choice of sampling stations and in pollution abatement measures applied to different locations – it is now an explicit requirement of European Union Directive 2000/60/EC (Water Framework Directive) and recommended by United States Agencies such as EPA and NOAA. The approach considers both natural characteristics and the human dimension, by means of a stepwise methodology, which considers, on the one hand, morphology and salinity distribution, and, on the other, appropriate indicators of pressure and state. In the present application, nitrogen and phosphorus loading was used as the pressure component and chlorophyll a and dissolved oxygen as indicators of state. The criteria for system division were defined based on (1) an adimensional shape factor and salinity classes for the natural component; and (2) a normalised pressure index and (ASSETS) eutrophication symptom classes for the human dimension. Water quality databases and GIS were used to develop spatial distributions for the various components, and the results were aggregated into a final water body division, using tidal excursion as a “common sense” test. The methodology was applied to three well-studied systems in Portugal, a tubular estuary (Mondego), a wide lagunal estuary (Sado) and a coastal barrier island system (Ria Formosa). Although a final definition of water bodies will usually be a policy decision, this type of approach for the division of coastal systems into management units scientifically informs the decision-making process.     

Collaborative fisheries management in the Northeast US: Emerging initiatives and future directions

The nature of participation by fishing organizations in fisheries management in the Northeast US is changing. Evidence of this is the number of groups that are actively seeking opportunities for group governance of marine resources. This article explores emerging collaborative or co-management arrangements in this region (a process whereby decision-making is shared between federal/council level and fishery stakeholder groups) and the shift towards an ecosystem-based approach to the management of marine fisheries.This research suggests that it is an opportune time for the development of a regional policy in the Northeast that provides an enabling environment in support of decentralized governance of federally managed marine fisheries. It also suggests that these initiatives can play a key role in operationalizing ecosystem-based management.     

Oxygen isotopes of phosphatic compounds—Application for marine particulate matter, sediments and soils

The phosphate oxygen isotopic composition in naturally occurring particulate phosphatic compounds (δ¹⁸O_p) can be used as a tracer for phosphate sources and to evaluate the cycling of phosphorus (P) in the environment. However, phosphatic compounds must be converted to silver phosphate prior to isotopic analysis, a process that involves digestion of particulate matter in acid. This digestion will hydrolyze some of the phosphatic compounds such that oxygen from the acid solution will be incorporated into the sample as these phosphatic compounds are converted to orthophosphate (PO₄³⁻). To determine the extent of incorporation of reagent oxygen into the sample, we digested various phosphatic compounds in both acid amended with H₂¹⁸O (spiked) and unspiked acid and then converted the samples to silver phosphate for δ¹⁸O_p analysis. Our results indicate that there is no isotopic fractionation associated with acid digestion at 50 °C. Furthermore, we found that reagent oxygen incorporation is a function of the oxygen to phosphorus ratio (O:P) of the digested compound whereby the percentage of reagent oxygen incorporated into the sample is the same as that which is required to convert all of the P-compounds into orthophosphate. Based on these results, we developed a correction for reagent oxygen incorporation using simple mass balance, a procedure that allows for the determination of the δ¹⁸O_p of samples containing a mixture of phosphatic compounds. We analyzed a variety of environmental samples for δ¹⁸O_p to demonstrate the utility of this approach for understanding sources and cycling of P.     

Effects of furadan in the brown mussel Perna perna and in the mangrove oyster Crassostrea rhizophorae

Furadan is a carbamate pesticide used widely to combat agricultural pests. However little information is available about the toxicity of furadan in aquatic macroinvertebrates. The in vivo effects of furadan were evaluated in mussels, Perna perna, and oysters, Crassostrea rhizophorae. Glutathione S-transferase (GST), catalase (CAT) and cholinesterase (ChE) activities were measured in the gills of both species exposed to furadan (100 microg/l) for 96 h. No changes were observed in GST activity in the exposed groups. CAT activity was higher (9%) in the oysters exposed to furadan. ChE activity was inhibited by 64 and 35%, respectively, in C. rhizophorae and P. perna exposed to furadan, suggesting that the former is more susceptible to the toxic effects of furadan.