DOAS observations of formaldehyde and its impact on the HO<Subscript>x</Subscript> balance in the tropical Atlantic marine boundary layer

Measurements of formaldehyde (HCHO) were made at the Cape Verde Atmospheric Observatory between November 2006 and June 2007 using the Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) technique. Observations show that typical HCHO mixing ratios ranged between 350 and 550 pptv (with typical 2-σ uncertainties of ~110 pptv), with several events of high HCHO, the maximum being 1,885?±?149 pptv. The observations indicate a lack of strong seasonal or diurnal variations, within the uncertainty of the measurements. A box model is employed to test whether the observations can be explained using known hydrocarbon photochemistry; the model replicates well the typical diurnal profile and monthly mean values. The model results indicate that on average 20% of HO₂ production and 10% of OH destruction can be attributed to the mean HCHO levels, suggesting that even at these low average mixing ratios HCHO plays an important role in determining the HO_x (HO₂+OH) balance of the remote marine boundary layer.     

Chloritoid-Bearing Mineral Assemblages in High-Pressure Metapelites from the Bughea Complex, Leaota Massif (South Carpathians)

High-Mg chloritoid (X_Mg = 0·40–0·47) andrelatively high-Mg staurolite (X_Mg = 0·25–0·28)coexisting with kyanite and garnet were identified in a mica–garnet-richrock associated with very high-pressure eclogites in the BugheaComplex of the Leaota Massif (South Carpathians). Major andtrace element geochemical data for both fresh eclogites andassociated rocks which represent a metasomatic or retrogradealteration rind of the eclogites, indicate a pelitic precursor.Magnesian chloritoid was found as inclusions in garnet as partof a chloritoid–kyanite–garnet assemblage whichis indicative of high-pressure conditions. The host garnet showsa typically prograde chemical zoning pattern. The chloritoid-bearingassemblage is confined to the inner part of the garnet porphyroblasts,whereas the matrix assemblage in equilibrium with Mg-rich garnetrims has exceeded the thermal stability limit of chloritoid.Pressure–temperature pseudosections for simplified compositionsapproaching the rock bulk-chemistry show a high-pressure fieldfor the identified chloritoid-bearing assemblage in good agreementwith pressure–temperature estimates in the CFMASH andKCFMASH chemical subsystems using analysed mineral compositions.The derived pressure–temperature path is clockwise, indicatingoverprinting during exhumation from 1·8 GPa and 580°Cto 1·15 GPa and 620°C, at a water activity approachinga_H2O = 1. These conditions were attained in a subduction mélangeindicating transient thermal perturbations of a subduction channel. KEY WORDS: high-pressure metapelite; Mg-rich chloritoid; P–T path; P–T pseudosection; very high-pressure eclogite     

Granitoid events in space and time: Constraints from igneous and detrital zircon age spectra

The goal of this study is to evaluate the global age distribution of granitoid magmatism and juvenile continental crust production with U/Pb isotopic ages from igneous and detrital zircons, and with Nd isotopic data. Granitoid age peaks, which are largely defined by TIMS data, are narrow and precise in contrast to detrital peaks that are often broad and hump-shaped due to the larger uncertainties of SHRIMP and LAM-ICPMS data. Granitic age peaks do not always have detrital counterparts and vice versa. Possible contributing factors to this mismatch are removal of crustal sources by erosion, inadequate sampling of granitoids because of cover by younger rocks, or small age peaks hidden by large age peaks in detrital spectra.Seven igneous peaks are found on five or more cratons or continents (3300, 2700, 2680, 2500, 2100, 1900 and 1100 Ma) and seven detrital peaks occur on three or more continents (2785, 2700, 2600, 2500, 1900, 1650 and 1200 Ma). Nd isotope distributions suggest important additions of juvenile continental crust at 2700, 2500, 2120, 1900, 1700, 1650, 800, 570 and 450 Ma. Tight clusters of craton ages occur for Superior–Karelia, Sao Francisco–Nain, and Kaapvaal–Siberia in the early Archean and for Wyoming–Kaapvaal–Slave, Superior–Nain, and West Africa–Amazonia in the late Archean. The global 2700-Ma peak is not a simple spike, but involves several peaks between 2760 and 2650 Ma. Events older than 3700 Ma are limited to the Yilgarn, Slave, Nain and North China cratons, and events between 2600 and 2500 Ma are widespread only in East Asia, Central and East Africa, and India.Single, short-lived mantle plume events at 2700 and 1900 Ga (or any other time) cannot easily account for prolonged episodes of granitoid magmatism during the Precambrian. The causes of geographically widespread and geographically restricted events are probably not the same.     

Capturing digital data with handheld devices to determine the redox regime,lithology, and provenance of siliciclastic sediments and residual deposits—a review and field manual

Geomagnetic (magnetic susceptibility), geoelectrical (resistivity and conductivity, self-potential/SP, induced polarization/IP), and radiometric measurements (gamma radiation of K, U, and Th) are well adapted to the needs and wants of geoscientists and exploration geologists, in particular, who widely use them in wireline tools and for ground surveys. Miniaturization of technical components resulted in the production of handheld devices which enable field geologists to an improving of the mineralogical and chemical database and the efficiency of the routine work in the field or at a drill site. The tools and devices used by a field geologist are categorized and presented in a tripartite set. The tools for routine field work with “hammer and laptop” belong to the A-level kit. The handheld devices under consideration constitute an intermediate level (B-level) to enhance the mineralogical and chemical database using physical methods. More advanced level applications make use of short-wave infra-red mineral analyzers or portable X-ray fluorescence devices (C-level). Handheld tools are designed for one-dimensional (cross-sectioning) and two-dimensional (mapping) surveys as well as drill core and cuttings examinations during terrain analysis. They can be operated in foot-borne surveys by one field geologist and the obtained data interpreted without an exuberant computing capacity. In the present overview, siliciclastic rocks and residual deposits have been singled out for their good response to the afore-mentioned methods. Their practical use is demonstrated by means of some case histories, each standing for a particular sedimentary lithology and discussed in combination with similar applications from literature: mixed-type (calcareous) siliciclastic rocks from Mesozoic–Cenozoic basins, SE Germany; residual argillaceous/kaolin deposits on top of granites of the Variscan basement, SE Germany; Neogene red-bed sediments from the promontory of the Tien Shan, East Uzbekistan; and Cretaceous gray-bed sediments with coal seams from the Baganuur basin, Central Mongolia. Cobweb diagrams, histograms, ternary diagrams, simple x-y plots and x-y plots in combination with spider diagrams have proved to be the most suitable ways when it comes to combine the data obtained from various methods and to illustrate these results for further interpretation on screen. The geophysical methods are discussed as to their strong and weak points to cater for a solution in three important subject matters of applied and genetic sedimentology: (1) constraining the redox regime, (2) determination of the lithology and mineralogy, (3) and provenance analysis and lithostratigraphy. Magnetic methods have proved to be useful for all objectives (1, 2, and 3), gamma spectrometry can successfully be applied for objectives 1 and 2, and micro-resistivity contributes significantly to solutions of objective 2. Magnetic and gamma spectrometric methods do not need any direct contact with the sedimentary rocks and therefore can be correlated with equivalent airborne surveys and are less depending on the wetability of the substrate and climate than the geoelectrical methods under study. The final goal of this review is to create a matrix of applicability of the methods and enable the field geologist to select the most suitable type of geophysical measurement or combination of tools for a solution to one of the three issues as a function of the sediment types under study.     

Antioxidants in the black mussel (Mytilus galloprovincialis) as an indicator of Black Sea coastal pollution

The biologically active compounds, antioxidant activities, and free radical scavenging effects of black mussel dry matter (Mytilus galloprovincialis)--(BMDM) were investigated. The extract from BMDM with absolute methanol (BMDMAMet) showed the strongest inhibition of lipid peroxidation as a function of its concentration, and was comparable to the antioxidant activity of butylated hydroxyanisole, at the same concentration of 0.2 mg/ml. The extract with 50%methanol/water (BMDM50%Met) had the weakest antioxidant activity, whereas other extracts such as 1.2 M HCl in 50%methanol/water (BMDM50%Met/HCl) exhibited an average inhibition of lipid peroxidation. BMDMAMet extract showed marked activities in free radical scavenging determined by beta-carotene bleaching (beta-carotene), nitric oxide (NO*) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS*+ methods. The antioxidant activities of BMDMAMet extract determined beta-carotene, NO* and ABTS*+ methods showed the highest correlation coefficients (R2) such as 0.998, 0.9976 and 0.6103, respectively, with the presence of total polyphenols. BMDM50%Met had lower antioxidant ability than BMDM50%Met/HCl in different scavenging methods, indicating that the major antioxidant components in these extracts must be derived from the polyphenols. Correlation between proteins and antioxidants was very low (0.0318 and 0.0433). The mussel extracts from polluted areas have shown by all using methods higher antioxidant activity than from the clean ones. The results presented in this report indicate that the antioxidant activities of mussel extracts could possibly be an additional index of pollution characterization.     

Heuristic considerations pertaining to hailstone size distributions in the plain of Friuli-Venezia Giulia

In this work, the hailstone size distributions at the ground in the plain of Friuli-Venezia Giulia are presented, as revealed through a network of polystyrene pads (hailpads), managed by volunteers, which has been active since 1988. The aim of this work is to highlight possible differences in the diurnal and seasonal behavior of hail at the ground, both from Friuli-Venezia Giulia and other countries, in order to improve the knowledge of this meteorological phenomenon.In the comparison between different countries, differences are found between the yearly size distributions of Friuli-Venezia Giulia and those of North-East Colorado, measured during the National Hail Research Experiment (NHRE). The size distributions obtained in South West France and in Friuli-Venezia Giulia are quite similar and they are slightly different from those of the Grossversuch experiment.In the comparison between different periods of the year, relevant differences are found between April and May and the other months. In particular, thunderstorms are less efficient in producing big hailstones during the former months. The most prolific month in producing hailstones is June, followed by September. This feature is interpreted as due to a form of synergy between the frequency of the synoptic forcing of storms and the amount of available energy at the ground.Analyzing the size distributions at different times of the day, the greatest differences are found in the intervals [00–06] and [06–12] in local time (respectively, [22–04] and [04–10] in UTC). These differences cannot be ascribed to the melting of the hailstones during their fall.     

Base isolation for retrofitting historic buildings: Evaluation of seismic performance through experimental investigation

An experimental test program on a full‐scale model representing a sub‐assemblage of the cloister facade of the Sao Vicente de Fora monastery, retrofitted through base isolation, has been recently carried out at the European Laboratory for Structural Assessment of the Joint Research Centre of the European Commission. In this paper an overview of the laboratory model and the experimental results is provided. In particular, firstly the test model is described, including the geometry and mechanical properties of the masonry specimen and the design of the isolation devices; then the testing method and the sub‐structuring of the isolation system are described and the seismic inputs adopted for the pseudo‐dynamic tests are defined. Finally, the experimental results are discussed and compared to the analogous results obtained on the ‘as is’, fixed‐base sub‐assemblage model. The implications of the test outcomes are emphasized and developments of this research line are presented. Copyright © 2001 John Wiley & Sons, Ltd.     

The anomalous ionospheric absorption on winter days

Summary Some results on ionospheric absorption measurements made at Genova-Monte Capellino in the years 1959 and 1960 are presented, deducing the behaviour of the mean diurnal variation. The abnormally high absorption during some days of January and February 1959 is then discussed, together with the treatment of data collected in various European and Asiatic stations; the geographical distribution of the phenomenon is studied, and the influence of meteors is also briefly considered.This paper has been read at the XII-Assembly of the I.G.G.U. in Helsinki (July–August 1960).     

Globalstrahlung und Sonnenaktivität

Summary Using the highest global irradiance values (Sun plus sky) at noon derived from the records gathered during the years 1958 to 1963 at Genova, Monte Capellino and Sauze d'Oulx, it is demonstrated that the thermal energy which the Earth receives from the Sun is dependent from the Sun activity. Precisely, an increase of the thermal energy withR _Z occurs up toR _Z=160–170, whereas for greater values ofR _Z the thermal energy received decreases with the increase ofR _Z.

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Herrn Prof. Dr.Hans Ertel zu seinem 60. Geburtstag gewidmet.