Microbially Contaminated Water in Urban Fountains as a Hidden Source of Infections     

Barbara D. Modrzewska  Magdalena Bartnicka  Joanna Blaszkowska 《洁净——土壤、空气、水》2019,47(8)

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Soil formation and weathering in a permafrost environment of the Swiss Alps: a multi‐parameter and non‐steady‐state approach          下载免费PDF全文

Barbara Zollinger  Christine Alewell  Christof Kneisel  Dagmar Brandová  Marta Petrillo  Michael Plötze  Marcus Christl  Markus Egli 《地球表面变化过程与地形》2017,42(5):814-835

Spatially discontinuous permafrost conditions frequently occur in the European Alps. How soils under such conditions have evolved and how they may react to climate warming is largely unknown. This study focuses on the comparison of nearby soils that are characterised by the presence or absence of permafrost (active‐layer thickness: 2–3 m) in the alpine (tundra) and subalpine (forest) range of the Eastern Swiss Alps using a multi‐method (geochemical and mineralogical) approach. Moreover, a new non‐steady‐state concept was applied to determine rates of chemical weathering, soil erosion, soil formation, soil denudation, and soil production. Long‐term chemical weathering rates, soil formation and erosion rates were assessed by using immobile elements, fine‐earth stocks and meteoric ¹⁰Be. In addition, the weathering index (K + Ca)/Ti, the amount of Fe‐ and Al‐oxyhydroxides and clay minerals characteristics were considered. All methods indicated that the differences between permafrost‐affected and non‐permafrost‐affected soils were small. Furthermore, the soils did not uniformly differ in their weathering behaviour. A tendency towards less intense weathering in soils that were affected by permafrost was noted: at most sites, weathering rates, the proportion of oxyhydroxides and the weathering stage of clay minerals were lower in permafrost soils. In part, erosion rates were higher at the permafrost sites and accounted for 79–97% of the denudation rates. In general, soil formation rates (8.8–86.7 t/km²/yr) were in the expected range for Alpine soils. Independent of permafrost conditions, it seems that the local microenvironment (particularly vegetation and subsequently soil organic matter) has strongly influenced denudation rates. As the climate has varied since the beginning of soil evolution, the conditions for soil formation and weathering were not stable over time. Soil evolution in high Alpine settings is complex owing to, among others, spatio‐temporal variations of permafrost conditions and thus climate. This makes predictions of future behaviour very difficult. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Efficacy of an In‐Well Sonde to Determine Magnetic Susceptibility of Aquifer Sediment          下载免费PDF全文

Todd H. Wiedemeier  Barbara H. Wilson  Mark L. Ferrey  John T. Wilson 《Ground Water Monitoring & Remediation》2017,37(2):25-34

Magnetite is a natural component of many aquifers. Abiotic degradation of chlorinated solvents by magnetite can be an important mechanism for natural attenuation of these contaminants. The quantity of magnetite in aquifer materials can be estimated by measuring the magnetic susceptibility of the materials. This is most commonly done by determining the magnetic susceptibility of core samples in an analytical laboratory using a magnetic susceptibility meter. Unfortunately, the cost of acquiring core samples often makes an evaluation of abiotic degradation by magnetite economically unrealistic. Downhole sondes (probes) are available for the determination of magnetic susceptibility. In this study, a downhole sonde was evaluated as an affordable alternative to acquiring and analyzing core samples. The sonde was introduced into 10 monitoring wells. The data from the sonde were then compared to data from core samples that were collected from the same elevation as the sonde data. The core samples analyzed in the laboratory were used as the standard against which the sonde data were compared. The downhole sonde reported values that were similar to values reported on core samples. At most wells, the means of the two measurements could not be distinguished at the 95% confidence interval. When the means could be distinguished, they still agreed within a factor of two.  相似文献   

Integrated monitoring of the hydro-morphodynamics of a beach protected by low crested detached breakwaters     

Renata Archetti  Barbara Zanuttigh 《Coastal Engineering》2010

The aim of this paper is to propose an integrated low cost system for monitoring the performance of beach defence works during storms. For this purpose, the site of Igea Marina, Northern Adriatic Sea, Italy, which is protected by low crested detached breakwaters, is selected. The monitoring system is composed by a video installation, for the identification of the shoreline position and of the intertidal bathymetry at high space and time resolution, and a 2DH numerical model, to reconstruct the hydrodynamics induced by coastal defenses. The accuracy of the monitoring system is verified against available measurements of waves and currents performed during a field campaign with acoustic Doppler profilers. Assimilation of data on the shoreline position in 2DH model operatively working is challenging in the improvement of the production of risk maps. These show the current intensities and flooded areas during forecasted storms. First promising results suggest the possibility of setting up an early warning tool.  相似文献   

Two- and three-dimensional maturation reaction norms for the eastern Baltic cod, Gadus morhua     

Vainikka  Anssi; Gardmark  Anna; Bland  Barbara; Hjelm  Joakim 《ICES Journal of Marine Science》2009,66(2):248-257

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Annual deformation signals from homogeneously reprocessed VLBI and GPS height time series   总被引：3，自引：3，他引：0  

Volker Tesmer  Peter Steigenberger  Markus Rothacher  Johannes Boehm  Barbara Meisel 《Journal of Geodesy》2009,83(10):973-988

The first part of this paper compares homogeneously reprocessed Very Long Baseline Interferometry (VLBI) and Global Positioning System (GPS) long-term height series from 1994 to 2007. The data analysis used fully adapted state-of-the-art models (like VMF1 and a priori zenith delays from ECMWF) for the GPS and VLBI processing. The series are compared in terms of long-term non-linear behaviour, harmonic and mean annual signals (not necessarily of harmonic nature). The similarity between both techniques is very good (especially the mean annual signals), which is assumed to be due to the adapted models and consistent reprocessing of both series. As two almost independent observing techniques see the same annually recurring signals at almost all co-located sites, we expect a good geophysical interpretability as integral vertical deformation. For the second part of this paper, the height time series of 161 suitable GPS sites (of the same solution as before) are used to determine a harmonic and a mean annual signal for each of them. Comparing the annual signals for this big dataset visually to GRACE-determined load deformations described in other publications, we find good agreement. This puts emphasis to the assumption that our height data have a lot of potential to be interpreted as geophysical signals. Out of these 161, 131 are grouped to 55 clusters, if at least two nearby (some thousand kilometres) sites show similar mean annual signals, which are thus confirmed to be real regional deformation, not local or technical artefacts. These 55 signals are presented on a “world map” of regional average mean annual height signals, as easy-to-handle tool to validate geophysical models. The data of these measured regional mean annual signals can be downloaded from a web-page for numerical analysis.  相似文献   

Ecotoxicological and human health risk in a petrochemical district of southern Italy   总被引：2，自引：0，他引：2  

Ausili A  Gabellini M  Cammarata G  Fattorini D  Benedetti M  Pisanelli B  Gorbi S  Regoli F 《Marine environmental research》2008,66(1):215-217

An ecotoxicological investigation has been carried in the petrochemical district of Priolo (Sicily, Italy), one of the largest in Europe. Results indicated a severe mercury contamination in sediments sampled near a chloro-alkali plant. A clear bioavailability of this element was demonstrated in mussels Mytilus galloprovincialis (both native and translocated) and the benthic fish Mullus barbatus, which also exhibited marked genotoxic damages. The elevated mercury concentrations in marine organisms are a serious concern for human health; according to the national average fish consumption, the provisional tolerable weekly intake (PTWI) of Hg would be easily exceeded by at least 4 to 12 fold. Such toxicological risk is of particular importance for pregnant women, being possibly involved in the elevated frequency of neonatal malformations.  相似文献   

Sponges boring into precious corals: an overview with description of a new species of Alectona (Demospongiae, Alectonidae) and a worldwide identification key for the genus     

Barbara Calcinai  Carlo Cerrano  Nozomu Iwasaki  & Giorgio Bavestrello 《Marine Ecology》2008,29(2):273-279

Precious corals represent peculiar substrata for several species of boring sponges that exploit their carbonatic scleraxis, strongly decreasing their commercial value. Here we describe a new species of the genus Alectona from Japan recorded in a colony of Paracorallium japonicum (Kishinouye, 1903). The spicular complement of the new species consists of diactinal spicules covered by mushroom-like tubercles, often modified into styloid forms, and fusiform amphiasters with two or sometimes four verticils, each generally made up of six short tubercled rays. A complete survey of the literature on boring sponges recorded in precious corals in the Mediterranean Sea and Pacific Ocean indicates that the species of the family Alectonidae are the most strictly associated to this kind of substratum. Their world distribution, in fact, partially or totally overlap that of their coral hosts.  相似文献   

Transmission of wave energy at permeable low crested structures     

Barbara Zanuttigh  Luca Martinelli 《Coastal Engineering》2008,55(12):1135-1147

This paper presents a conceptual model for the prediction of energy transmission in presence of emergent permeable low crested structures. The transmitted wave is reconstructed from the superposition of perturbations generated leeward the structure by filtration and overtopped volumes. The model requires only structure geometry and incident wave conditions (wave height, period). A fair agreement is obtained by comparing the predicted transmission coefficients and wave spectra with measurements performed in wave flume and wave basin.  相似文献   

Wave reflection from coastal structures in design conditions     

Barbara Zanuttigh  Jentsje W. van der Meer 《Coastal Engineering》2008

Based on an extensive database of more than 4000 data, this paper analyses wave reflection for various types of coastal structures in design conditions, such as smooth, rock and armour unit slopes. A new simple formula has been developed that relates the reflection coefficient to the breaker parameter and seems to fit all kinds of revetment materials by changing two coefficients. These coefficients depend only on the correct roughness factor, provided by recent research on overtopping discharges. The effects on reflection due to composite slopes and to low crests are also examined and proper extensions of the formula are provided.  相似文献