871 research outputs found

    Root reinforcement and slope bioengineering stabilization by Spanish Broom (<i>Spartium junceum</i> L.)

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    The present paper deals with the root system's characteristics of Spanish Broom (<i>Spartium junceum</i> L.), a species whose capacity for adaptating and resisting to drought is worth investigating. In particular, the aims of the study were 1) to investigate the plant's bio-mechanical aspects and 2) to verify whether root reinforcement and the field rooting ability of stem cuttings enhance its potential for use in slope stabilization and soil bio-engineering techniques, particularly in the Mediterranean areas. <br><br> Single root specimens were sampled and tested for tensile strength, obtaining classic tensile strength-diameter relationships. Analysis were performed on the root systems in order to assess root density distribution. The Root Area Ratio (RAR) was analyzed by taking both direct and indirect measurements, the latter relying on image processing. The data obtained were used to analyze the stability of an artificial slope (landfill) and the root reinforcement. The measurement and calculation of mean root number, mean root diameter, RAR, root cohesion and Factor of safety are presented in order to distinguish the effect of plant origin and propagation. <br><br> Furthermore, tests were performed to assess the possibility of agamic propagation (survival rate of root-ball endowed plants, rooting from stem cuttings). These tests confirmed that agamic propagation is difficult, even though roots were produced from some buried stems, and for practical purposes it has been ruled out. <br><br> Our results show that Spanish Broom has good bio-mechanical characteristics with regard to slope stabilization, even in critical pedoclimatic conditions and where inclinations are quite steep, and it is effective on soil depths up to about 50 cm, in agreement with other studies on Mediterranean species. It is effective in slope stabilization, but less suitable for soil bio-engineering or for triggering natural plant succession

    Suitability of soil bioengineering techniques in Central America: a case study in Nicaragua

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    International audienceIn the last few years "D. I. A. F." (Department of Agriculture and Forestry Engineering of Florence University), has been testing the effectiveness of Soil Bio-Engineering techniques in Central America. The focus of the present study was to find out which native plants were most suited for soil bio-engineering purposes, particularly in the realization of riverbank protection. Furthermore, we have also been aiming at economic efficiency. In the context of sustainable watershed management, these techniques seem to be appropriate, especially in underdeveloped countries. Concerning the plants to be used, we considered three native species, Gliricidia Sepium, Cordia dentata and Jatropha curcas, to be appropriate for this type of work. Economically speaking, the low cost of such interventions in underdeveloped countries, has been shown by the construction of riverbank protection using vegetated crib-walls in Nicaragua

    The relevance of the research on the psychosocial dimensions of aging is really the same in europe and USA?

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    The paper by Kirilov and Coll." Active aging and elderly’s quality of life: Comparing the impact on literature of projects funded by the European Union and USA" has the merit of focusing on a strongly critical general theme: the weight given to the results of literature in Europe and the USA. The subject matter is everywhere relevant, but somewhat more critical in Europe, would mean an imbalance of interest between the two countries. However, the results of the research reassure us: apparently, the projects financed with public money in Europe and in the US have the same impact in the literature

    Forest cover influence on regional flood frequency assessment in Mediterranean catchments

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    The paper aims at evaluating to what extent the forest cover can explain the component of runoff coefficient as defined in a regional flood frequency analysis based on the application of the rational formula coupled with a regional model of the annual maximum rainfall depths. The analysis is addressed to evaluate the component of the runoff coefficient which cannot be captured by the catchment lithology alone. Data mining is performed on 75 catchments distributed from South to Central Italy. Cluster and correlation structure analyses are conducted for distinguishing forest cover effects within catchments characterized by hydro-morphological similarities. We propose to improve the prediction of the runoff coefficient by a linear regression model, exploiting the ratio of the forest cover to the catchment critical rainfall depth as dependent variable. The proposed regression enables a significant bias correction of the runoff coefficient, particularly for those small mountainous catchments, characterised by larger forest cover fraction and lower critical rainfall depth

    Exploring physical and psychosocial well-being and self-awareness as a new frontier in active aging

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    The knowledge about the effects of exercise, physical and sport activities on general well-being has been advanced thanks to pioneering studies in several medical conditions and in rehabilitation from the 1980s onwards [1]. However, a noteworthy contribution to improving standard tools hallowing to measure of how much exercise, physical and sport activities could affect the quality of life (QoL) of the elderly and adults came mainly from the studies on their effects on depression and mental health

    Alguns problemas sĂłcio-culturais no ensino de portuguĂŞs

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    PRIMI RISULTATI DI UN INDAGINE SULLO STATO DELLE SISTEMAZIONI IDRAULICO-FORESTALI NEL BACINO DELL’ARNO

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    Il presente lavoro è relativo ai risultati ottenuti con il primo stato d’avanzamento di una ricerca sullo stato delle Sistemazioni Idraulico-Forestali per assegnate aree di indagine comprese nel bacino del fiume Arno affidata dall’ Autorità di Bacino del Fiume Arno al Dipartimento di Ingegneria Agraria e Forestale dell’Università degli Studi di Firenze. Innanzi tutto, è stata condotta un’analisi preventiva, mediante un database, di documentazione relativa alle opere idrauliche già censite in precedenti lavori (prof. Grazi) con identificazione della posizione geografica delle opere stesse con l’ausilio di software GIS. A questa prima fase sono seguiti la predisposizione di una opportuna scheda di rilievo (sia cartacea sia elettronica) e quindi sopralluoghi in campo condotti mediante l’ausilio di un GPS collegato a computer palmare per il supporto cartografico di base. Rilievi di dettaglio sono stati condotti nei torrenti dell’area del Mugello, già oggetto di studi risalenti a una trentina di anni fa per la valutazione delle pendenze di compensazione (Falciai et al.) che sono stati utilizzati spesso in letteratura (Ferro et al., Pica et al., etc.). Con riferimento ad altre zone campione del bacino (es. Casentino e Area Fiorentina), la documentazione storica ed il sopralluogo in campo (su base statistica) ha avuto lo scopo di rintracciare le opere esistenti e verificare l’attendibilità e la confrontabilità dei vari censimenti eseguiti anche da altri Enti preposti. In particolare si è analizzato il dimensionamento delle opere ed il loro stato attuale di conservazione ed efficienza, confrontandolo con quanto riportato in eventuali elaborati progettuali e nei censimenti precedenti. Eventuali danneggiamenti dei manufatti possono essere derivati dalle valutazioni in sede progettuale, da scarsa o inesistente manutenzione o da mutate caratteristiche in alveo e nel bacino. Per avere qualche indicazione in proposito si è valutata la portata di progetto a partire dalle dimensioni delle gavete considerate come stramazzi in parete grossa e se ne è stimato il tempo di ritorno, mediante i modelli AlTo (Regione Toscana) e Idrarno (Autorità di Bacino). Questa fase ha richiesto un lavoro preventivo di queries spaziali che hanno lo scopo di attribuire il codice dell’asta a cui appartengono le opere idrauliche in esame (all’interno del reticolo idrografico del modello AlTo e all’interno del reticolo “Sistema Acque” dell’Autorità di Bacino dell’Arno). Questa operazione consente, inoltre, il collegamento tra il contenuto informativo del geodatabase dell’Autorità di Bacino con il sistema di regionalizzazione delle portate di piena della Regione Toscana. Mediante la misura delle caratteristiche dimensionali dell’opera si sono cercate di ricavare anche indicazioni statistiche riguardo alla pendenza di compensazione dei corsi d’acqua in esame. Le verifiche in campo ha permesso anche una descrizione delle condizioni generali dell’alveo in cui sono situate le opere e dei versanti siti in prossimità delle opere stesse. I dati raccolti sono stati immessi in un geodatabase opportunamente costruito secondo lo standard di quello esistente presso l’Autorità di Bacino del Fiume Arno e quindi elaborati per la ricerca delle relazioni tra le caratteristiche delle opere e la pendenza attuale dell’alveo nonché la stima della necessità, per i corsi d’acqua esaminati, di opere atte a garantire la continuità fluviale per la ittiofauna (Pini Prato e Barneschi)
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