1,721,007 research outputs found
E. Allen Bateman, Superintendent of Murray School District from 1928 - 1933
No full textE. Allen Bateman, third superintendent of Murray City Schools, 1928-1933
Armorel Dixon (Viola) and Allen Bateman (Valentine), outdoor production of "Twelfth Night" performed on the University of Utah campus, May 29-30 and June 2, 1914
No full textBlack and white photograph of Armorel Dixon as Viola and Allen Bateman as Valentine in an outdoor production of "Twelfth Night," performed on the University of Utah campus, May 29-30 and June 2, 1914.
RICOSTRUZIONE E MODELLAZIONE NUMERICA DI UN EVENTO DI FLASH FLOOD. Il caso di Atrani 2010
Get PDFDalle alluvioni del Salernitano del 1954 a quella di Atrani nel 2010 la ricorrenza degli eventi registra una tendenza
crescente incrinando l’accezione stessa di eccezionalità del fenomeno calamitoso. In coda ormai ad un decennio di
continua attivazione dei comparti tecnico-scientifici di settore, il supporto della ricerca scientifica agli strumenti di misura
e mitigazione della pericolosità idraulica si concretizza particolarmente nella codifica di modelli matematici e numerici
per la simulazione preventiva dei fenomeni generativi e di quelli propagativi dell’evento alluvionale. Lo studio
ricostruisce l’evento di flash flood che il 9 Settembre 2010 ha investito l’abitato di Atrani (Costiera Amalfitana). Grazie
ad una dettagliata attività di rilievo di campo, nei giorni immediatamente successivi all’evento, è stato possibile stimare
alcune caratteristiche del fenomeno tra cui i valori di riferimento per i tiranti e le velocità della corrente. La formazione
della piena è stata ricostruita attraverso il modello afflussi-deflussi geomorfologico del tipo WFIUH (Width Function
Istantaneous Unit Hydrograph). L’idrogramma così ottenuto ha costituito la condizione al contorno di monte per la
simulazione delle dinamiche propagative dell’onda di piena in area urbana. Per lo studio idraulico ci si è avvalso di
un codice matematico-numerico originale (2D FLATModel) operante su griglie di calcolo non-strutturate. Gli strumenti
utilizzati hanno fornito una simulazione dell’evento in buon accordo con le osservazioni di campo dimostrandosi quindi
adeguati per la simulazione e la previsione degli eventi di flash flood in contesti analoghi a quello di studio
DERIVATION OF CRITICAL RAINFALL THRESHOLDS FOR DEBRISFLOW WARNINGS THROUGH MATHEMATICAL AND NUMERICAL MODELING
No full textThe aim of the work is to develop a system capable of providing debris flow warnings in areas where historical events data are not available as well as in the case of changing environments and climate. For these reasons, critical rainfall threshold curves are derived from mathematical and numerical simulations rather than the classical derivation from empirical rainfall data. The possible formation of debris flow is simulated through infinite-slope stability analysis. Land instability is governed by the increases of groundwater pressures due to rainfall. The simulations are performed in a virtual basin, representative of the one studied, taking into account the uncertainties linked with the definition of the characteristics of the soil. A large number of calculations are performed which take into account the entire range of the governing input dynamic variables (rainfall characteristics) and different combinations between them. The dynamic variables considered are the antecedent rainfall, the intensity of the triggering rainfall and its duration. The multiple combinations of the input dynamic variables giving failure is therefore obtained. For each failure, the corresponding debris flow volume is estimated. The resulting database is elaborated in order to obtain rainfall threshold curves. These curves may be used for the real time evaluation of possible debris flow events on the basis of observed and forecasted rainfall
Armorel Dixon (Viola) and Allen Bateman (Valentine) reunited, scene from outdoor production of "Twelfth Night" performed on the University of Utah campus, May 29-30 and June 2, 1914
No full textBlack and white photograph of the scene in which Armorel Dixon (Viola) and Allen Bateman (Valentine) are reunited, during an outdoor production of "Twelfth Night," performed on the University of Utah campus, May 29-30 and June 2, 1914
Experimental and numerical simulation of three dimensional gravity currents on smooth and rough bed
No full textThe dynamics of a three-dimensional gravity current is investigated by both laboratory experiments and numerical simulations. The experiments take place in a rectangular tank, which is divided into two square reservoirs with a wall containing a sliding gate of width b. The two reservoirs are filled to the same height H, one with salt water and the other with fresh water. The gravity current starts its evolution as soon as the sliding gate is manually opened. Experiments are conducted with either smooth or rough surface on the bottom of the tank. The bottom roughness is created by gluing sediment material of different diameters to the surface. Five diameter values for the surface roughness and two salinity conditions for the fluid are investigated. The mathematical model is based on shallow-water theory together with the single-layer approximation, so that the model is strictly hyperbolic and can be put into conservative form. Consequently, a finite-volume-based numerical algorithm can be applied. The Godunov formulation is used together with Roe's approximate Riemann solver. Comparisons between the numerical and experimental results show satisfactory agreement. The behavior of the gravity current is quite unusual and cannot be interpreted using the usual model framework adopted for two-dimensional and axisymmetric gravity currents. Two main phases are apparent in the gravity current evolution; during the first phase the front velocity increases, and during the second phase the front velocity decreases and the dimensionless results, relative to the different densities, collapse onto the same curve. A systematic discrepancy is seen between the numerical and experimental results, mainly during the first phase of the gravity current evolution. This discrepancy is attributed to the limits of the mathematical formulation, in particular, the neglect of entrainment in the mathematical model. An interesting result arises from the influence of the bottom surface roughness; it both reduces the front velocity during the second phase of motion and attenuates the differences between the experimental and numerical front velocities during the first phase of motion
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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