Perturbed nonlocal fourth order equations of Kirchhoff type with Navier boundary conditions

Abstract We investigate the existence of multiple solutions for perturbed nonlocal fourth-order equations of Kirchhoff type under Navier boundary conditions. We give some new criteria for guaranteeing that the perturbed fourth-order equations of Kirchhoff type have at least three weak solutions by using a variational method and some critical point theorems due to Ricceri. We extend and improve some recent results. Finally, by presenting two examples, we ensure the applicability of our results

Interpolation of rainfall through polynomial regression in the Marche Region (Central Italy)

Notwithstanding its small size (less than 10000 km2), because of its varied topography, ranging from the Apennines Range (up to more than 2000 m amsl) to coastal environments, the Marche Region (the Adriatic side of Central Italy), is characterized by many different types of climate. In this region there are no fully satisfactory models to interpolate and generalize rainfall data from the 111available meteorological recording stations; however, in this study an innovative way to interpret data linking precipitation to many topographic parameters is introduced. Based on those considerations, statistical analyses were carried out on rainfall historical series in order to assess significantly variations during the last 60 years and to create a model capable of explaining rainfall distribution based on geo-graphical and topographic parameters. Thus on one hand was highlighted a significant decrease of rainfall from 1961-1990 to 1991-2016, over the whole period, in the hilly and mountainous sectors (100-200 mm), while closer to the coast the difference is slight (about 0 – 100 mm), on the other the new model highlights the presence of some outliers, which may lead to a better comprehension of climatic dynamics in this area

Effetti economici e sociali del sisma sugli allevamenti dell’Alto Maceratese

Il contributo analizza la filiera zootecnica dell’Alto Maceratese danneggiata dal sisma del 2016. Rispetto ad alcune difficolta storiche (marginalità territoriale e spopolamento), questa analisi si è concentrata sugli effetti del sisma. In collaborazione con i veterinari della Regione Marche, è stato somministrato ad un campione di 55 famiglie di allevatori un questionario semi-strutturato al fine di osservare le caratteristiche socio-economiche degli allevamenti (prevalentemente a media quota e dediti nella metà dei casi unicamente all’attività zootecnica) e i danni prodotti dal sisma (ad abitazioni, patrimonio zootecnico e strutture agricole). L’ultima sezione del questionario raccoglie alcune proposte di miglioramento nella fase di ricostruzione. Proprio la rigenerazione dei territori colpiti, infatti, sembra porre ambizione sfide che riguardano il ripristino delle attività lavorative e il ritorno della popolazione sul territorio

Considerazioni sull’utilizzo delle sabbie dragate al largo di Civitanova Marche (Adriatico centrale) per il ripascimento delle spiagge.

Sono state analizzate le principali caratteristiche dei sedimenti dragati al largo di Civitanova Marche (Adriatico centrale), confrontandole con quelle degli arenili delle Marche meridionali al fine di evidenziare la lor compatibilità. Particolare attenzione è stata dedicata all'analisi del sito di Marina Palmense (Comune di Fermo) in cui nel luglio 2007 il materiale dragato è stato utilizzato per un primo ripascimento. Dallo studio è risultata l'incompatibilità dei materiali dragati con la dinamica costiera lungo quasi tutto il tratto investigato, compreso quello già sottoposto a rifluimento, dimostratosi inefficace

Climatologie des brouillards epais dans la plaine du Po (Italie Septentrionnelle).

Aim of this work was to provide a first picture of the thick fog frequency, i.e. with horizontal visibility lower than 100 meters, in the Po plain, condition which causes remarkable problems to the aerial and motor tra ic. The analysis of this phenomenon has been possible by the study of the SYNOP messages, provided by the Meteorological Service of the Air Force in stations of survey which had cadence every three hours, continuous surveys or higher than 90% of the total potential. Therefore, the number of stations selected for the analysis has got down up to 15. Moreover, quite homogeneously distributed in the padano-veneto territory and along the coast of the high Adriatic Sea. The analysis was directed towards a calculation of a number of days with thick fog and to the evidence of the thirty-year tendencies concerning the phenomenon. The study of the minimum monthly minimum temperatures has allowed to understand that the increase in temperature registered in the undergoing study's period partly explains the general tendency to the decrease of the phenomenon but does not completely clarify the significant present differences between stations having the same increase in the temperatures. It is then possible to assume that the local morphology and its changes in the analysed thirty-year period may have a strong weight in explanations of the above-mentioned differences

Climatic conditions and sporadic permafrost in the Maiella Massif (Cental Apennines, Italy)

Climatic data were examined for some ten weather recording stations, in order to verify the presence of favorable conditions for preserving sporadic mountain permafrost in the Maiella Massif (Central Apennines, Italy). The analyzed data refer to the time-span 1965-1990; they have been gathered for recording stations located at altitudes ranging from sea level (Pescara) to over 2100 m a.s.l. (Campo Imperatore, Gran Sasso Massif). The mean annual average temperatures were ca. 6-7 °C in the higher areas; the seasonal means ranged from –4 °C in winter to 12 °C in summer. Average thermal gradients vary from 0.4 °C/100 m in January to 0.7 °C/100 m in July, with an annual average of 0.57 °C/100 m. Based upon these data, the altitude of the 0 °C isotherm in free air in the Maiella Massif is ca. 2500 m, whilst the –2 °C isotherm, which can be used as the lower climatic limit for the presence of permafrost, should be located slightly over 2750 m a.s.l., on average. The precipitation regime generally has sub-Mediterranean features, which are progressively more evident moving from the Adriatic to the Tyrrhenian side. It shows a maximum in late autumn or winter and a minimum in summer, locally associated with a secondary maximum in late spring. Annual precipitation ranges around 1200-1400 mm, both in the high plains and on the main mountain peaks. Snow falls are abundant, especially along the eastern sides of the mountain groups, because of direct exposition to Balcanic-Danubian cold currents. At 1000 m a.s.l., generally 150 to 200 cm of snow fall are recorded and a snow blanket is present for ca. 70 days, concentrated in the November-April period; at ca. 2000 m a.s.l. (Campo Imperatore), the snow fall sums up to 400 cm and 180-200 days of persistence are recorded from the end of October to the end of May. Analyzing the above situation, it is possible to infer that the general climatic framework allows the presence of permafrost only close to the top of the Maiella Massif, at altitudes exceeding 2750 m a.s.l. On the other hand, the bottom temperatures of winter snow cover (BTS) recorded in the Upper Cannella Valley, where sun irradiation is particularly reduced and wind blows very energetically during the cold period, demonstrate that permafrost can exist even at relatively low altitudes (ca. 2400 m a.s.l.) in particular morphologic conditions. This emphasizes the fact that micro-climatic conditions are instrumental in the energy balance of the ground, and therefore in the presence of permafrost