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21.
Human activities in coastal areas have increased the occurrence of eutrophication events, especially in vulnerable ecosystems such as coastal lagoons. Although we have a general knowledge of the consequences of eutrophication in these ecosystems, some efforts need to be made to understand biotic feedbacks that could modify the response of the environment to nutrient enrichment. The plant-mediated 'coastal filter' is one of the main factors that determine lagoonal efficiency in processing excess nutrients. In this context, the present paper examined the relative contribution of benthic macrofauna to the 'coastal filter' of a Mediterranean lagoon. The analysis of macrofaunal assemblages in the Mar Menor lagoon led to a clear differentiation between shallow areas of net nutrient recycling and exportation and deeper areas of net retention. These differences enhance nutrient removal from the water column, thus increasing the ecosystem's resistance to eutrophication. 相似文献
22.
Arnaldo Belluigi 《Pure and Applied Geophysics》1959,43(1):182-194
Riassunto Fino ad oggi sono apparse solo teorie elettrogeosmotiche transitorie unidimensionali. Quì risolviamo un problema del genere bidimensionale, con elettrodi verticali cilindrici. Le curve rappresentative delle portate d'acqua catodicaq
K
a cui perveniamo, denotano diminuzioni abbastanza rapide fino ai tempi dell' ordine dei «tempi elettrodici », (t=), portate che poi diminuiscono in modo molto lento. Si riscontrano quì più estesi «pianerottoli»q
K
che non quelli delle monodimensionalità (t=/9). Inoltre, col crescere dei rapporti distanze eteropolari-raggi catodici, o col diminuire dei raggi catodici, tali portate (che si compongono dei contributi dei singoli anodi) s'incrementano nel modo diagrammato.
Summary Till now only mono-dimensional transient electro-geoosmotical theories have been published. In this paper a solution is given for a problem of bi-dimensional type, with vertical cylindrical electrodes. The plots which represent the amounts of cathodic waterq K show quite rapid lowerings as far as to reach time durations of the order of «electrodic times » (t=) volumes which, after, diminish very slowly. In this case more extendedq K «lobbies» are found than those in mono-dimensional case (t=/9). Furthermore increasing the ratios heteropolar spacings—cathodic radii, or diminishing the cathodic radii, water discharges (which result from the contribution of the single anods) increase as plotted in the diagrams.相似文献
23.
Prof. Dr. Arnaldo Belluigi 《Pure and Applied Geophysics》1956,34(1):51-56
Riassunto L'A. mostra corne dal metodo più semplice di misura di rcsistività d'un suolo del polo singolo, si possano dedurrc tutti gli altri (Wenner, Schlumberger, ecc). CiÒ dà la possibilità di risalire immediatamente dai grafici
s
di un dispositivo a quelli di un altro. L'A., dopo rettificato recenti valutazioni del metodo dei due punti, rimuove la pretesa da altri formulata di porre gerarchie nei dispositivi di misure
s
.
Relazion e presentata il 5 Aprile 1956 alla Quarta Assemblea Generale dcllaSocietà Italiana di Geofisica e Meteorologia (Genova: 5–8 Aprile 1956). 相似文献
Summary The Author shows how departing from simplest method of the ground resistivity measurement with the single pole can be deduced all another methods (Wenner, Schlumberger, etc.). That gives the practical possibility to pass immediately the s graphics of one arrangement to these of other types of arrangement. After having rectified recently mades evaluations about the two points method, the Author removes the requirements made from other side to graduate the s measuring arrangements.
Zusammenfassung Der Verfasser zeigt wie man von der einfachsten Methode der Widerstandsmessung eines Bodens mit Einzelpol alle anderen Methoden (Wenner, Schlumberger, usw.) ableiten kann. Dadurch hat man die praktische Möglichkeit, von den s Diagrammen einer Anordnung sofort auf jene anderer Anordnungen überzugehen. Nach Richtigstellung von kürzlich geäusserten Ansichten über die Zweipunktmethode, beseitigt der Verfasser die von Anderen gestellten Ansprüche, die s Messanordnungen vermeintlichen Vorzügen nach staffeln zu wollen.
Relazion e presentata il 5 Aprile 1956 alla Quarta Assemblea Generale dcllaSocietà Italiana di Geofisica e Meteorologia (Genova: 5–8 Aprile 1956). 相似文献
24.
Prof. Arnaldo Belluigi 《Pure and Applied Geophysics》1956,34(1):57-65
Riassunto L'A. espone a titolo di sintesi, alcuni propri risultati che riguardano le questioni dei principi d'equivalenza nei sondaggi elettrici, e l'erroneità di alcune leggi di composizione relative a terreni a più strati.
Relazione presentata il 5 Aprile 1956 alla Quarta Assemblea generale dellaSocietà Italiana di Geofisica e Meteorologia (Genova: 5–8 Aprile 1956). 相似文献
Summary The Author explais as a synthesis come own results about the equivalence principles of the electric soundings and the erronousness of some composition laws regarding grounds with more layers.
Zusammenfassung Der Verfasser erklärt als Synthese einige Ergebnisse über die Equivalenzgrundlageu der elektrischen Sondierungen und den falschen Inhalt einiger Verteilungsgesetze betreffend die Boden mit mehrerer Schichten.
Relazione presentata il 5 Aprile 1956 alla Quarta Assemblea generale dellaSocietà Italiana di Geofisica e Meteorologia (Genova: 5–8 Aprile 1956). 相似文献
25.
In this paper, a reliable Land-Surface Process Model (LSPM), which is a new version of the LPM of Ji and Hu (1989), is described. The LSPM has been validated with experimental data measured at two stations in the Po Valley (Northern Italy). 相似文献
26.
Benthic recovery during open sea fish farming abatement in Western Mediterranean, Spain 总被引：1，自引：0，他引：1
Fish farming is an important source of organic matter input in coastal waters, which contributes to eutrophication. In this study, the macrofaunal benthic community was studied after the cessation of fish farming with the aim of improving our understanding of benthic succession and sediment recovery in a marine ecosystem. The results showed that the best environmental variables for assessing organic pollution were acid-volatile sulfides (AVS) and redox potential. Succession and recovery was best explained by macrofaunal analysis based on community composition as well as on trophic groups. The patterns of recovery differed between each impacted station. For this reason, succession could not be accurately predicted due to the unique environmental parameters and the singular community functional structure of each location. The Azti Marine Benthic Index (AMBI) proved its validity for assessing pollution but did not distinguish between successional stages. 相似文献
27.
Enrico Ferrero Luca Mortarini Massimigliano Manfrin Arnaldo Longhetto Rita Genovese Renato Forza 《Boundary-Layer Meteorology》2009,130(3):347-363
Boundary-layer instabilities are studied by analyzing the results of laboratory simulations of wall turbulence in a shear-driven
rotating flow. The experiments were carried out in the Turin University Laboratory rotating water tank, where a circular flow
was generated by either increasing (spin-up) or decreasing (spin-down) the rotation speed of the platform. The flow was measured
using a Particle Image Velocimetry technique and the developed turbulence analyzed. Two cases were accounted for, in the former
the measurements were performed over a smooth surface (bottom of the tank), while in the latter a rough-to-smooth transition
was considered. The turbulent boundary layer developed inside the tank is analyzed by means of vertical profiles of mean and
turbulent quantities and on the basis of drag coefficients. Then turbulent structures developed in the different cases are
shown and discussed in terms of the vorticity fields. Finally, an analysis based on the concept of swirling strength was carried
out to select among the vortex extremes those associated with a coherent structure. 相似文献
28.
Prof. Arnaldo Belluigi 《Pure and Applied Geophysics》1958,39(1):72-95
Summary The A. with this third publication brings to an end his three-dimensional general theory of electro-osmosis, studying the problem of how to distribute poli-electrodes in the way in which they most often occur in practice. The A. exemplifies about twenty cases of electrodic distributions: linear- and point-form electrodes, at ground-surface and deep-seated electrodes; and more he makes some general formulae suitable to circumstances wich may occur in practice. A deep investigation of this problem has been necessary, first for a theorical orientation and second for practical application, and more because, as it may be stated by the existing bibliography, till now the electrodic distributions were performed with only empiric and often erroneous criteria. 相似文献
29.
Ivan Blecic Arnaldo Cecchini 《International journal of geographical information science》2013,27(3):349-374
The objective of this computational study was to investigate to which extent the availability and the way of use of historical maps may affect the quality of the calibration process of cellular automata (CA) urban models. The numerical experiments are based on a constrained CA applied to a case study. Since the model depends on a large number of parameters, we optimize the CA using cooperative coevolutionary particle swarms, which is an approach known for its ability to operate effectively in search spaces with a high number of dimensions. To cope with the relevant computational cost related to the high number of CA simulations required by our study, we use a parallelized CA model that takes advantage of the computing power of graphics processing units. The study has shown that the accuracy of simulations can be significantly influenced by both the number and position in time of the historical maps involved in the calibration. 相似文献
30.
Ivan Blečić Arnaldo Cecchini Tanja Congiu Giovanna Fancello Giuseppe A. Trunfio 《International journal of geographical information science》2013,27(8):1350-1374
We present a methodology and a planning and design support software tool for evaluating walkability and pedestrian accessibility of places which are relevant for people’s capabilities, and thus an important component of quality of life in cities. A multicriteria evaluation model, at the core of the decision support system, is used to assign walkability scores to points in urban space. Walkability scores are obtained through algorithms which process spatial data and run the evaluation model in order to derive potential pedestrian routes along the street network, taking into account the quality of urban space on several attributes relevant for walkability. One of its notable characteristics is a certain reversal of perspective in evaluating walkability: the walkability score of a place does not reflect how that place is per se walkable, but instead how and where to can one walk from there, that is to say, what is the walkability the place is endowed with. This evaluation incorporates three intertwined elements: the number of destinations/opportunities reachable by foot, their walking distances, and the quality of the paths to these destinations. In this article, we furthermore demonstrate possible uses of the support system by reporting and discussing the results of a case-study assessment of a project for the Lisbon’s Segunda Circular (Second Ring Road). The software tool is made freely available for download. 相似文献