87,595 research outputs found
Le architetture di Ridolfi e Frankl
No full textCatalogo della Mostra "Le architetture di Ridolfi e Frankl
Comparison of different hydrological similarity measures to estimate flow quantiles
No full textThis paper aims to evaluate the influence of hydrological similarity measures on the definition of homogeneous regions. To this end, several attribute sets have been analyzed in the context of the Region of Influence (ROI) procedure. Several combinations of geomorphological, climatological, and geographical characteristics are also used to cluster potentially homogeneous regions. To verify the goodness of the resulting pooled sites, homogeneity tests arecarried out. Through a Monte Carlo simulation and a jack-knife procedure, flow quantiles areestimated for the regions effectively resulting as homogeneous. The analysis areperformed in both the so-called gauged and ungauged scenarios to analyze the effect of hydrological measures on flow quantiles estimation.</p
An analytical model to relate the vertical root distribution to climate and soil properties
No full textWe propose an analytical model to relate the vertical distribution of plant roots in water controlled ecosystems to the local climatic and pedologic conditions. We find that the shape of the root profile is determined by the distribution of the incoming rainfall pulses, and that the rooting systems are deeper where the soils are coarse-textured and the evaporative demand slightly exceeds precipitation. Citation: Laio, F., P. D'Odorico, and L. Ridolfi (2006), An analytical model to relate the vertical root distribution to climate and soil propertie
C. Ridolfi
No full textBotanico: Ridolfi, Cosimo (1769-1844), marchese.
Professore di agraria nell\u27Università di Pisa.
Titolo sul recto.
1 incisione : litografia ; 293 x 211 mm.
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Plants in water-controlled ecosystem: active roles in hydrological processes and response to water stress. I: Scope and general outline
No full textThis series of four papers studies the complex dynamics of water-controlled ecosystems from the hydro-ecological point of view [e.g., I. Rodriguez-Iturbe, Water Resour. Res. 36 (1) (2000) 3-9]. After this general outline, the role of climate, soil, and vegetation is modeled in Part II [F. Laio, A. Porporato, L. Ridolfi, I. Rodriguez-Iturbe, Adv. Water Res. 24 (7) (2001) 707-723] to investigate the probabilistic structure of soil moisture dynamics and the water balance. Particular attention is given to the impact of timing and amount of rainfall, plant physiology, and soil properties. From the statistical characterization of the crossing properties of arbitrary levels of soil moisture, Part III develops an expression for vegetation water stress [A. Porporato, F. Laio, L. Ridolfi, I. Rodriguez-Iturbe, Adv. Water Res. 24 (7) (2001) 725-744]. This measure of stress is then employed to quantify the response of plants to soil moisture deficit as well as to infer plant suitability to given environmental conditions and understand some of the reasons for possible coexistence of different species. Detailed applications of these concepts are developed in Part IV [F. Laio, A. Porporato, C.P. Fernandez-Illescas, I. Rodriguez-Iturbe, Adv. Water Res. 24 (7) (2001) 745-762], where we investigate the dynamics of three different water-controlled ecosystems
Sancti Bernardini ... Opera quae extant omnia ... : in quatuor tomos distincta
No full textEs el tomus primusMarca tip. en portColofónSign. : 1-10\p4\s, a-f\p4\s, A-Z\p8\s, 2A-2M\p8\s, 2N\p4\sError de numeración en la última pTexto a dos colPort. grab. calc.: "Franco F.
Al-in-amphibole barometry of calcalkaline magma: assessment of active subvolcanic systems.
No full textCa-amphiboles (hornblende-hastingsite-pargasite solution) have been historically tested by many authors in order to discern their physic-chemical stability and the evolution of calcalkaline magmas at subduction-related systems. In general these amphiboles show direct proportional stability curves in P-T diagrams and, at high-T, their crystallization involves high fO2 and H2O contents of the melt.
Several mechanisms such as Edenite-reaction, Tschermak-reaction and Fe3+ = [6]Al exchange are inferred to drive the Al content of amphibole by the variation of T, P and fO2, respectively. Althought the degree of these exchanges have not been experimentally verified, the influence of T and fO2 on the Al-in-amphibole is considered to be negligible compared with pressure. In this framework, several Al-barometers were calibrated for subalkaline low-T granitoids (T < 800°C) and seem to fit well (±1 kbar) in the range of 2-12 kbar (i.e. Johnson & Rutherford, 1989; Thomas & Ernst, 1990). By contrast, these barometers tested with amphiboles synthesized at higher T, from calcalkaline basaltic andesite-rhyolite rocks (Johnson & Rutherford, 1989; Martel et al., 1999; Scaillet & Evans, 1999; Pichavant et al., 2002; Klimm et al., 2003; Rutherford & Devine, 2003) demonstrate to be inaccurate with errors up to ±2.1 kbar (±7.5 km of granitic-equivalent crust).
Using the above published data on Ca-amphiboles mainly synthesized by “crystallization methods” from calcalkaline rocks, we calibrated two new barometers suitable for basaltic andesite-andesite (BAAB) and dacite-rhyolite (DRB) series. BAAB is a 2nd order polynomial equation, i.e. P = 1.3701Al2 - 1.8457Al + 1.6116 (R2 = 0.95), valuable at high-T (825-1000°C) and fO2 (ΔNNO between +0.4 and +2.2) accounting for a maximum error of ±0.61 kbar (~2.2 km). The DRB calibrated at lower T (700-834°C) and between -0.2 and +2.0 ΔNNO, works even better (±0.49 kbar, ~1.8 km) and is characterized by a relation which accounts for the tetrahedral aluminium only (P = 3.3629[4]Al3 - 7.0947[4]Al2 + 3.8369[4]Al + 1.9063; R2 = 0.98). This is probably due to the removal of the fO2 dependence (i.e. Fe3+ = [6]Al) which should play an important role in the high-viscosity (dacite-rhyolite) magmas.
The BAAB applied to the amphiboles within the November 2002 calcalkaline products (early andesite pumice falls and late basaltic andesite-andesite lavas) of El Reventador volcano (Ecuador) allowed to constrain the magma chamber location between 8 km (pumice phenocrysts) and 11 km (lava poikilitic crystals). The poikilitic crystal depth fit well with the 10-11 km deep hypocenter earthquake swarm occurred ~1 month before the eruption, which should represent the mafic intrusion event at the bottom of the magma chamber (Ridolfi et al., submitted).
The same calculation on amphibole phenocrysts (i.e. Mg-hastingsite; Menna, 2000) within high-K calcalkaline andesites of the Petrazza pyroclastics (85-60 ka; Paleostromboli I, Italy) emphasizes crystallization depths of 12-14 km. This calculation fairly agree with the data on the early fluid inclusions within quartzite xenoliths of the Strombolicchio (200 ka) and Paleostromboli II (60 ka) extrusives, which suggest significant magma rest at depths of ~11 km (Vaggelli et al., 2003).
The Al-in-amphibole is strongly dependent on both P and composition of the magma and it is worth to note the use of inappropriate amphibole barometers could lead to blunders in locating magma chambers up to 9.5 kbar as shown by the pressure difference between BAAB and DRB calculations on the Stromboli amphiboles
REFERENCES
Johnson, M.C., Rutherford, M.J., 1989: Geology 17, 837-841.
Klimm, K., Holtz, F., Johannes, W., King, P. L., 2003: Precam. Res. 124, 327-341.
Martel, C., Pichavant, M., Holtz F., Scaillet, B., Bourdier, J.L., Traineau, H., 1999: J. Geoph. Res. 104, 29453-29470.
Menna, M., 2000: Unpublished Degree Thesis, Univ. Urbino, IT, pp. 109.
Pichavant, M., Martel, C., Bourdier, J. L., Scaillet, B., 2002: J. Geoph. Res. 107, B5, 2093, 10.1029/2001JB000315.
Ridolfi, F., Puerini, M., Renzulli, A., Menna, M., Toulkeridis, T.: J. Volc. Geoth. Res., submitted.
Rutherford, M.J., Devine, J.D., 2003: J. Petrol. 44, 1433-1454.
Scaillet, B., Evans, B.W., 1999. J. Petrol. 40, 381-411.
Thomas, W.M., Ernst W.G. 1990: Geochem. Soc., Spec. Publ. 2, 59-63.
Vaggelli, G., Francalanci, L., Ruggeri, G., Testi, S. 2003: Bull. Volcanol. 65, 385-404
Sancti Bernardini Senensis Ordinis Minorum ... Quadragesimale de Euangelio aeterno ...
No full textColofónMarca tip. en portSign.: I\p4\s, a-e\p4\s, f\p2\s, A-Z\p8\s, 2A-2Y\p8\s, 2Z\p6\sTexto a dos co
Orthogonal-Array based Design Methodology for Complex, Coupled Space Systems
No full textThe process of designing a complex system, formed by many elements and sub-elements interacting between each other, is usually completed at a system level and in the preliminary phases in two major steps: design-space exploration and optimization. In a classical approach, especially in a company environment, the two steps are usually performed together, by experts of the field inferring on major phenomena, making assumptions and doing some trial-and-error runs on the available mathematical models. To support designers and decision makers during the design phases of this kind of complex systems, and to enable early discovery of emergent behaviours arising from interactions between the various elements being designed, the authors implemented a parametric methodology for the design-space exploration and optimization. The parametric technique is based on the utilization of a particular type of matrix design of experiments, the orthogonal arrays. Through successive design iterations with orthogonal arrays, the optimal solution is reached with a reduced effort if compared to more computationally-intense techniques, providing sensitivity and robustness information. The paper describes the design methodology in detail providing an application example that is the design of a human mission to support a lunar base
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