Confronto fra i regimi pluviometrici di Genova e Savona

Riassunto L'esame dei giorni di ciascun anno dal 1886 al 1900 nei quali si sono avute precipitazioni apprezzabili tanto a Genova quanto a Savona (località distanti fra loro 35 km) viene istituito utilizzando l'indice di similitudineS recentemene introdotto daM. Bouët. La discussione dei risultati dimostra fra l'altro come le località marittime a ridosso di catene montuose siano più adatte a mettere in luce le variazioni nel tempo delle caratteristiche climatiche.

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Zusammenfassung Ausgehend von der Anzahl der gleichzeitigen Niederschlagstagen in Genua und Savona (Abstand 35 km) wurde der AehnlichkeitsindexS nachBouët für jedes Jahr der Periode 1886–1900 berechnet. Die Diskussion der Ergebnisse zeigt u.a., dass die maritimen Orte, die am Fusse einer Bergkette liegen, gewöhnlich besser als die kontinentalen geeignet sind die zeitlichen Veränderungen der klimatischen Verhältnisse darzustellen.

     

Le possibilita' minerarie della Provincia di Messina

Riassunto Premessi alcuni richiami sulle caratteristiche geologiche della Provincia di Messina, si illustrano le possibilità minerarie della regione in base specialmente alle indagini eseguite dal R. Istituto Geofisico e Geodetico di Messina. Dal relativo esame consegue l'importanza delle manifestazioni di minerali metallici con giacimenti che possono assicurare una produzione notevole—sopratutto per il rame, ma anche il piombo, antimonio, zinco, ferro, ecc.—nonostante la distribuzione complessa ed irregolare delle mineralizzazioni. In pari tempo sono segnalate altresi le sicure possibilità di un conveniente sfruttamento degli scisti bituminosi, delle ligniti, nonchè di altri materiali (fluorite, caolino,...) di cui è dotato il sottosuolo della Provincia di Messina.

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Zusammenfassung Nach der Untersuchungen des R. Istituto Geofisico e Geodetico zu Messina werden die bergbauwürdigen Lagerstätten der Messina-Provinz beschrieben und erörtet. Das geschieht unter einer allgemeinen Erwähnung der geologischen Bedingugen. Dazu lässt sich zeigen, wie die Messina-Provinz besonders reich an Erz-Lagerstätte ist, vor allem an Kupfer-Erze, weiter auch an Blei-, Antimon-, Zink-, Eisen-Erze, usw, obwohl die Verteilung einigermassen kompliziert und ungleichmässig ist. Auch die bauwürdigen Lagerstätten der anderen Materialen, wie bituminose Schiefer, Braunkohlen, usw werden erwähnt.

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Résumé Après un bref rappel des caractères géologiques de la Province de Messina, on documente les possibilités minières de la région surtout à la suite des recherches faites par l'Istituto Geofisico e Geodetico di Messina. De l'examen rélatif dérive l'importance des maniféstations en mineraux métalliques, avec gisements capables de donner une production convenable—particulièrement de cuivre, mais aussi de plomb, d'antimoine, de zinc, de fer, etc,—malgré la distribution complexe et irrégulière des minéralisations. On mentionne aussi les autres possibilités d'exploitation des gîtes de schistes bitumineuses, de lignites et d'autres matériaux.

     

SporadicE-layer ionization and sunspot cycle

Summary The correlation between the sunspot cycle and the sporadicE-layer ionization is investigated at middle latitudes. Higher mean values off ₀Es occur generally with higher sunspot numbers. Some evidence for a phase-shift between long term time-variation in sunspot numbers andf ₀Es is obtained. The solar cycle variation ofEs is somewhat larger over the Far East. Regarding the behaviour of the time-development ofEs events in diurnal variation, an interpretation is proposed.     

On the lunar semidiurnal variation of theD andF2 layers

Summary The lunar semidiurnal variation of ionospheric absorption at Freiburg and of thef ₀ F2 at, Genova, Freiburg and Léopoldville has been deduced. The results are compared with those obtained by other Authors. Magnetic dip, rather than geomagnetic latitude, is found to be a parameter controlling the morphology of the lunar semidiurnal variation of theF2 layer. Finally, a graphical representation of the amplitude of lunar semidiurnal variation off ₀ F2 as function of the magnetic dip is also given.

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Riassunto Viene determinata la variazione lunare semidiurna dell'assorbimento ionosferico per Friburgo e della frequenza critica dello stratoF2 per Genova, Friburgo, Léopoldville. I risultati sono confrontati con quelli ottenuti da altri Autori per varie stazioni situate in diverse parti del globo. In particolare si trova che la inclinazione magnetica, meglio della latitudine geomagnetica, è il parametro che regola la morfologia della variazione lunare inF2. Infine si dà una rappresentazione grafica dell'ampiezza della variazione lunare dellaf ₀ F2 come funzione dell'inclinazione magnetica.

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This research was supported by a grant from the Committee on Lunar Variation (IAGA). The paper has been presented at the XII-Assembly of the I.G.G.U. in Helsinki (July–August 1960).     

Incorporating spatial and temporal information for urban drainage model calibration: An approach using preference ordering genetic algorithm

In order to successfully calibrate an urban drainage model, multiple criteria should be considered, which raises the issue of adopting a method for comparing different parameter sets according to a set of objectives. Multi-objective genetic algorithms (MOGA) have proved effective in numerous such applications, where most of the techniques relying on the condition of Pareto efficiency to compare different solutions. However, as the number of criteria increases, the ratio of Pareto optimal to feasible solutions increases as well, worsening the efficiency of the genetic algorithm search. In this paper, firstly the drawbacks of single objective calibration approach are highlighted. Then, a new MOGA, the preference ordering genetic algorithm, is proposed, that alleviates the drawbacks of conventional Pareto-based methods. The efficacy of this algorithm is demonstrated on the calibration of a physically-based, distributed sewer network model, and the comparison is made with a known MOGA NSGA-II. The results are very encouraging because the obtained parameter sets closely resembled both calibration and validation events. The identifiability of 10 model parameters were analysed, showing significantly smaller ranges of optimal values for parameters related to impervious areas compared to those related to pervious areas, which is reasonable considering relatively low rainfall intensities. In addition to standard ways of presenting calibration results, “radar” plots were also used to present information on trade-off for eight objective functions for four rainfall-runoff events.     

The European Water Framework Directive 2000/60/EC in the evaluation of the ecological status of watercourses. Case study: the river Chienti (central Apennines,Italy)

The quality of the river Chienti (eastern‐central Apennines, Italy) has been evaluated according to the Water Framework Directive 2000/60/EC, taking into consideration both biotic (animal and vegetable) and chemical parameters. In studying the biotic component, two indices were used: the E.B.I, Extended Biotic Index (version adapted to the Italian rivers), based on macroinvertebrates, and the EPI‐D, the Eutrophication and/or Pollution Index, based on diatoms. For both macroinvertebrates and diatoms, two samplings were conducted, one in June and the other in October 2003. Instead, according to the Italian Law 152/99 the chemical and bacteriological analyses were conducted monthly for the entire year. The results of biomonitoring and chemical‐bacteriological analyses unanimously demonstrated a good ecological situation for the upper section of the Chienti, though the situation tends to worsen as the river continues its descent and undergoes increased anthropogenic pressure. Data obtained were correlated with Spearman's coefficients and principal component analysis. Both statistical calculations showed clear, direct correlation between the two biotic indices and an inverse correlation between these and the chemical and bacteriological parameters. However, a few differences of judgement that emerged among the various indices highlight the importance of using them simultaneously in order to obtain a more accurate diagnosis of the ecological status of the watercourses.     

武汉天河机场低能见度现象的气候特征分析

利用武汉天河机场1996—2005年共10 a的地面气象观测资料,对该机场低能见度现象的年变化、日变化等气候特征进行了统计分析,结果表明低能见度现象在冬季出现得最多,夏季最少。春、秋、冬三季低能见度出现频率较高的时段比较接近。在对影响能见度的天气现象和低能见度的持续时间进行研究后发现雾是造成低能见度形成的最主要原因,而春、秋、冬三季低能见度的持续时间在2~4 h之间的居多。     

Effects of column axial force – bending moment interaction on inelastic seismic response of steel frames

It is well known that axial force – bending moment interaction (N–M interaction) affects to a large extent the cyclic inelastic behaviour of structural elements, especially columns in framed structures, with reduction in bending capacity and loss of available ductility. A few studies have also shown that significant inelastic axial shortening affects the response of column elements subjected to medium–high levels of axial loads and cyclic bending. This paper is primarily aimed at evaluating the effects of column N–M interaction on the inelastic seismic response of steel frames. By considering the contemporaneous action of vertical loads, due to gravity, and of horizontal seismic excitation, it is shown that the progressive axial shortening of adjacent columns may differ substantially, thus inducing significant relative settlements at the ends of the connecting beams and, then, remarkable amplifications in beam plastic rotations. An evaluation of additional beam plastic rotations induced by column N–M interaction is carried out for real structures by investigating the inelastic response of steel frames designed according to European standards under horizontal and vertical earthquake excitations. Copyright © 2003 John Wiley & Sons, Ltd.