Influence of salinity and fish species on PAH uptake from dispersed crude oil     

Ramachandran SD  Sweezey MJ  Hodson PV  Boudreau M  Courtenay SC  Lee K  King T  Dixon JA 《Marine pollution bulletin》2006,52(10):1182-1189

The use of chemical oil dispersants to minimize spill impacts causes a transient increase in hydrocarbon concentrations in water, which increases the risk to aquatic species if toxic components become more bioavailable. The risk of effects depends on the extent to which dispersants enhance the exposure to toxic components, such as polycyclic aromatic hydrocarbons (PAH). Increased salinities can reduce the solubility of PAH and the efficiency of oil dispersants. This study measured changes in the induction of CYP1A enzymes of fish to demonstrate the effect of salinity on PAH availability. Freshwater rainbow trout and euryhaline mummichog were exposed to water accommodated fractions (WAF), and chemically-enhanced water accommodated fractions (CEWAF) at 0 per thousand, 15 per thousand, and 30 per thousand salinity. For both species, PAH exposure decreased as salinity increased whereas dispersant effectiveness decreased only at the highest salinity. Hence, risks to fish of PAH from dispersed oil will be greatest in coastal waters where salinities are low.  相似文献   

Crystal chemistry, surface morphology and X-ray photoelectron spectroscopy of Fe-rich osumilite from Mt. Arci, Sardinia (Italy)     

Chiara Elmi  Maria Franca Brigatti  Luca Pasquali  Monica Montecchi  Angela Laurora  Daniele Malferrari  Stefano Nannarone 《Physics and Chemistry of Minerals》2010,37(8):561-569

Microprobe analysis, single crystal X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray absorption spectroscopy were applied on Fe-rich osumilite from the volcanic massif of Mt. Arci, Sardinia, Italy. Osumilite belongs to the space group P6/mcc with unit cell parameters a = 10.1550(6), c = 14.306(1) Å and chemical formula (K_0.729)_C (Na_0.029)_B (Si_10.498 Al_1.502)_T1 (Al_2.706 Fe _0.294 ²⁺ )_T2 (Mg_0.735 Mn_0.091 Fe _1.184 ²⁺ )_AO₃₀. Structure refinement converged at R = 0.0201. Unit cell parameter a is related to octahedral edge length as well as to Fe²⁺ content, unlike the c parameter which does not seem to be affected by chemical composition. The determination of the amount of each element on the mineral surface, obtained through X-ray photoelectron spectroscopy high-resolution spectra in the region of the Si_2p, Al_2p, Mg_1s and Fe_2p core levels, suggests that Fe presents Fe²⁺ oxidation state and octahedral coordination. Two peaks at 103.1 and 100.6 eV can be related to Si⁴⁺ and Si¹⁺ components, respectively, both in tetrahedral coordination. The binding energy of Al_2p, at 74.5 eV, indicates that Al is mostly present in the distorted T2 site, whereas the Mg peak at 1,305.2 eV suggests that this cation is located at the octahedral site. X-ray absorption at the Fe L_2,3-edges confirms that iron is present in the mineral structure, prevalently in the divalent state and at the A octahedral site.  相似文献   

Connecting the primordial and Galactic deuterium abundances     

Gary Steigman  Donatella Romano  Monica Tosi 《Monthly notices of the Royal Astronomical Society》2007,378(2):576-580

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Procida volcanic history: new insights into the evolution of the Phlegraean Volcanic District (Campania region,Italy)     

Gianfilippo?De AstisEmail author  Lucia?Pappalardo  Monica?Piochi 《Bulletin of Volcanology》2004,66(7):622-641

New stratigraphic, major- and trace-element, and Sr-, Nd- and Pb- isotopic data on volcanic deposits older than 14 ka from the island of Procida, Italy, are presented and compared with published analyses from the rest of the Phlegraean Volcanic District (PVD). Procida rocks range in composition from basalt to shoshonite and trachyte and show ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb ratios varying within the ranges 0.70523–0.70678, 0.512539–0.512630, 18.99–19.29, 15.67–15.69 and 39.10–39.39, respectively. The presence of a compositional gap in the range SiO₂=54–59 wt % is evidence of magma bimodality, and suggests that the feeding magmatic system was formed by at least two different reservoirs located at different depths. Geochemical and isotopic variations with increasing differentiation can be explained by fractional crystallization mechanisms, that in some cases were associated with crustal contamination that occurred in both deeper and shallower reservoirs; the most evolved magmas formed in the shallower one. Mixing/mingling processes also occurred. The variation of isotopic composition through time observed both for Procida and for Campi Flegrei and Ischia rocks is evidence of strong affinity between magmas that erupted on the entire PVD until about 40 ka. This indicates that they share a common origin and a common plumbing system. Most of the PVD eruptive centers active until about 40 ka lie within a NE-SW-oriented volcano-tectonic belt extending from the southeastern part of Ischia, through Procida and Torregaveta volcano to the northeastern sector of the present Campi Flegrei caldera. This not only indicates the existence of a link between regional structures and volcanism in the area, but also suggests that PVD magma genesis and evolution were strongly regulated by extensional tectonics. In the last 40 ka the mafic rocks erupted along this extensional structure – from Torregaveta and the islands of Ischia and Procida – indicate that it still represents an important crustal discontinuity that focuses mantle-derived magmas. Procida trachybasalts are enriched in large ion lithophile elements (LILE) and light and middle rare earth elements (LREE and MREE), and show slight negative anomalies in the high field strength elements (HFSE) relative to average MORB. A slight depletion in HREE is present. Trace element and isotope systematics can be referred to a lithospheric mantle source. The lithospheric mantle source carries intra-plate and slab-derived components, the latter probably inherited from a previous subduction event.  相似文献   

Interference Testing for Atmospheric HOx Measurements by Laser-induced Fluorescence     

Xinrong Ren  Hartwig Harder  Monica Martinez  Ian C. Faloona  David Tan  Robert L. Lesher  Piero Di Carlo  James B. Simpas  William H. Brune 《Journal of Atmospheric Chemistry》2004,47(2):169-190

Accurate OH and HO₂ (collectively called HO_x) measurements by laser-induced fluorescence (LIF) may be contaminated by spurious signals from interfering atmospheric chemicals or from the instrument itself. Interference tests must be conducted to ensure that observed OH signal originates solely from ambient OH and is not due to instrument artifacts. Several tests were performed on the Penn State LIF HO_x instrument, both in the laboratory and in the field. Theseincluded measurements of the instrument's zero signal by using either zero air or perfluoropropylene to remove OH, examination of spectral interferences from naphthalene, sulfur dioxide, and formaldehyde, and tests of interferences by addition of suspected interfering atmospheric chemicals, including ozone, hydrogen peroxide, nitrous acid, formaldehyde, nitric acid, acetone, and organic peroxy radicals (RO₂). All tests lacked evidence ofsignificant interferences for measurements in the atmosphere, including highly polluted urban environments.  相似文献   

Photodegradation of the pharmaceuticals atorvastatin, carbamazepine, levofloxacin, and sulfamethoxazole in natural waters     

Monica W. Lam  Scott A. Mabury 《Aquatic Sciences - Research Across Boundaries》2005,67(2):177-188

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Landslides in Emilia-Romagna region (Italy): strategies for hazard assessment and risk management   总被引：1，自引：2，他引：1  

Giovanni Bertolini  Monica Guida  Marco Pizziolo 《Landslides》2005,2(4):302-312

In Emilia-Romagna, over 32,000 landslide bodies cover one-fifth of the hilly and mountainous territory. The majority of them originated as earth-flows after the last glacial maximum and grew during the rainiest periods of the Holocene through the superimposition of new earth-flows. Reactivation of these large landslides is the main problem the geologists of Emilia-Romagna are facing now. Intense and/or prolonged precipitation play a major role as triggering factors in reactivating landslide bodies, but also the importance of snowmelt is suggested by the monthly distribution of landslide events. Almost all the present-day landslide activity is due to the reactivation of pre-existing landslide bodies. Consequently, territorial planning and geo-thematic cartography are fundamental tools for the reduction of risk. The Emilia-Romagna geo-thematic cartography (1:10,000) is legally binding and regulates land use in regional, municipal and basin plans.  相似文献   

A surge of Skobreen, Svalbard     

Monica Sund 《Polar research》2006,25(2):115-122

Surging glaciers are common in Svalbard yet relatively few glaciers have been observed during a surge. This paper presents observations of the currently surging glacier Skobreen, in southern Spitsbergen. The study is based on examinations of new and archival photographs and maps. Skobreen, an 18 km² valley glacier terminating into the lower part of the glacier Paulabreen, has not been registered previously as a surging glacier. Skobreen experienced a build-up in its upper part, while there has been a lowering of the surface in the terminal region. Photographs from 1990 show incipient crevassing in the upper part. Photographs from 2003 show a slight advance of the terminus and marginal crevassing, indicating an initiation period of about 15 years for a surge of this glacier. In June 2005 transverse crevassing appeared in the upper part of the glacier, while the middle section moved as a block with strong shear margins and a pronounced drawdown of the ice surface. No traces of a surge front could be seen in the crevasse pattern. However, the crevasse pattern indicates an initiation area in the transition zone between the transverse crevassing in the upper part and the block of ice in the middle region.  相似文献   

Magma ascent and eruptive processes from textural and compositional features of Monte Nuovo pyroclastic products, Campi Flegrei, Italy     

Monica Piochi  Giuseppe Mastrolorenzo  Lucia Pappalardo 《Bulletin of Volcanology》2006,68(5):496-496

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1997年9月26日意大利中部Umbria-marche地震前的水文地质变化     

Monica Carro  Lucia Luzi  曹玲玲 《国际地震动态》2006,(7):71-85

分析了1997年9月26日意大利中部Umbria与marche交界地区的Umbria-marche地震序列引起的水文体系的变化。为了量化水文体系的变化,从地方当局和矿泉水公司收集了地下水位、泉水的流量以及河水流速等的资料,这些资料可以确定异常的影响面积,并且可以通过与从震前几年资料估算出的年平均体系的对比来量化异常的变化,试图对异常进行判定。分析结果表明,两个含水单元,即Umbria-marche山峰和Val-nerina单元,具有紧密的联系,它们都由于水文系统的改变而受到影响。地震前几个月两条河流测量站记录到了异常变化,认为是地震前兆异常。  相似文献