Search results for " sistema."
showing 10 items of 1920 documents
Testing a Simplified Approach to Determine Field Saturated Soil Hydraulic Conductivity
2013
Abstract Interpreting and simulating hydrological processes need a large number of field saturated soil hydraulic conductivity, Kfs , data that should be collected with simple and rapid field experiments. A Simplified method based on a Beerkan Infiltration run (SBI method) was recently developed and tested successfully on Burundian soils. With the SBI method, a cylinder is inserted to a short depth into the soil and the infiltration time of a few small volumes of water repeatedly applied at the surface of the confined soil is measured. Calculating Kfs needs the slope of the linearized cumulative infiltration vs. time relationship and an estimate of the so called α* parameter. In this invest…
Lista bibliografica
2007
Questa lista bibliografica contiene il secondo aggiornamento della bibliografia della Lisy e deriva dall’assemblaggio da parte della redazione (M. Serdoz ed E. Panfili) dei contributi parziali stilati dai gruppi regionali.
Typification of the name Statice calcarae (Plumbaginaceae), basionym of the threatened endemic Limonium calcarae
2018
Limonium calcarae (basionym Statice calcarae), a rare diploid species endemic to Sicily, is one of the few members of the genus that occurs in the inland areas of the island. According to IUCN criteria, it has been assessed as critically endangered but recent data on its distribution, demography and threats affecting its populations are lacking. A lectotype is designated, preserved at PAL, and isolectotypes have been traced and verified in other European herbaria.
The territories of tourism: a reflection about the experience of the Tourist Districts (Local Tourism Systems) in Sicily
2013
The tourist district is an important tool for territorial governance of regional tourism. The district is a type of Local System which is characterized by its multidimensionality, as well as the spatial contiguity of traders who belong to it. The territory is a space transformed by social interactions and relations of production: it is therefore the indispensable reference for measuring the impact of tourism. A bottom up approach in the process of identification of the districts is therefore vital. A Balance Score Card-approach is desirable to correctly manage this process. This study is a preliminary analysis derived from direct experience of the Sicilian tourist districts, recently formed…
Las cajas de ahorros españolas : gestión en una crisis y consecuencias de la misma
2013
Este trabajo estudia los problemas que han sufrido las entidades de crédito españolas en la crisis financiera que están soportando. El estudio se centra en las variables que afectan al impago de los créditos en general centrándose en las diferencias que existen entre las cajas de ahorros y los bancos comerciales en cuanto al impacto de la misma. Los resultados obtenidos indican que los bancos obtienen mejores resultados que las cajas en la morosidad. Como variables significativas que incrementan la morosidad están: las adjudicaciones de activos inmobiliarios, el volumen de participadas y el número de concurso de acreedores declarados. Entre las variables que contribuyen a reducir la morosid…
Predicting soil loss in central and south Italy with a single USLE-MM model
2018
Purpose: The USLE-MM estimates event normalized plot soil loss, Ae,N, by an erosivity term given by the runoff coefficient, QR, times the single-storm erosion index, EI30, raised to an exponent b1> 1. This modeling scheme is based on an expected power relationship, with an exponent greater than one, between event sediment concentration, Ce, and the EI30/Pe(Pe= rainfall depth) term. In this investigation, carried out at the three experimental sites of Bagnara, Masse, and Sparacia, in Italy; the soundness of the USLE-MM scheme was tested. Materials and methods: A total of 1192 (Ae,N, QREI30) data pairs were used to parameterize the model both locally and considering all sites simultaneously. …
Contribution to the knowledge of Inonotus baumii in Thailand
2015
Inonotus baumii in Thailand is reported on three new host-plants: Acacia tomentosa, Shorea robusta, and S. siamensis. A key for the identification of Inonotus species in Thailand accompanies notes on the taxonomy of I. baumii.
Overland flow hydrodynamic characteristics in rough beds at low Reynolds numbers
2022
This paper considers overland flow resistance at low Reynolds numbers through analysis of experimental runs carried out using water only and water/glycerol mixtures. We first examined the power relationship between the Darcy–Weisbach friction factor f and the Reynolds number Re to obtain the values of the K coefficient and b exponent. These results confirmed the applicability of the values of b suggested in literature, while K required a specific calibration for laminar open-channel flows. The analysis revealed that transition from a laminar to turbulent flow regime for water only flows occurred at a threshold value of Re equal to 500 as described historically. The estimate of f by the powe…
Effect of a Heavy Rainstorm on the Surface Hydrodynamic Properties of a Sandy-Loam Soil
2022
Changes in surface-soil hydrodynamic properties associated with torrential natural rainstorms are largely unknown. This investigation aimed at verifying if the surface hydrodynamic properties of a sandy-loam soil varied due to the heavy rainfall event (130 mm in nearly three hours) that occurred in the summer of 2020 at Palermo (Italy) and also to establish if soil recovery processes occurred soon after the event. The soil of an orchard was sampled immediately before the rainstorm and a few days and 1.5 months later. The rainstorm determined a moderate decrease (by 1.8 times) of the saturated soil hydraulic conductivity, Ks, and an increase of its relative variability. In the subsequent wee…
A test of water pouring height and run intermittence effects on single-ring infiltration rates
2018
Assessing how the infiltration process depends on the water impact energy improves interpretation of hydrological processes. Impact energies vary with the height of water pouring; that is, the distance between the water delivery point and the soil surface. The effects of the height of water pouring on infiltration in an initially near saturated soil can be tested in the field by two repeated Beerkan infiltration runs separated by a short pause (30 min) and using both low (non-perturbing) and high (perturbing) heights of water application. The double two-stage Beerkan run methodology was applied in two soils. The infiltration rate at the end of the perturbing stage of the experiment was 0.2–…