Search results for "HRES"
showing 10 items of 695 documents
Class-B two-photon Fabry–Pérot laser
1998
Abstract We study the stationary operation and stability properties of a class-B two-photon Fabry–Perot laser. We show that, differently from the one-photon laser, the intensity emitted by the two-photon laser is larger in a Fabry–Perot than in a ring cavity. The lasing solution loses stability through a subcritical Hopf bifurcation, as it occurs in the unidirectional ring laser. The stability domain in the parameter space is larger in the Fabry–Perot than in the ring cavity configuration.
Progress in Modelling Coherently Pumped Far-Infrared Laser Dynamics
1990
Coherently pumped lasers (CPL) operating in the far-infrared spectral region shown a wealth of instabilities1, including a behavior remarkably similar2,3 with the predictions of the paradigmatic Lorenz-Haken model of a single-mode homogeneously broadened laser4,5. The qualitative agreement; between theory and experiments2,3 was rather surprising, for the model4,5 refers to a two-level system whereas the CPL operate on a three-level scheme, where the pumping and lasing transitions share a common upper level. Dupertuis et al.6 have identified conditions for the mathematical reduction of the CPL equations to the Lorenz-Haken equations4, but these conditions were not all fulfilled in the experi…
La casa Ipertestuale - Stanze e spazio-soglia
2010
Stanze e spazio soglia Il saggio descrive i risultati di un'esperienza di seminario/workshop extracurriculare, svoltosi a Palermo nel 2005 (dal titolo: “Futura. Come abiteremo domani”). La metafora dell’ipertesto, spesso utilizzata da architetti, filosofi e urbanisti come metafora significativa per descrivere la condizione metropolitana contemporanea, risulta particolarmente efficace quale rappresentazione sintetica dell’idea di casa che abbiamo inteso indagare, per alcune sue qualità essenziali che trovano immediato riscontro nelle nuove modalità dell’abitare. All’interno del tema più generale della casa “ipertestuale”, la sperimentazione diretta dal Emanuele Palazzotto ha inteso esplorare…
LA QUESTIONE ABITATIVA TRA SOSTENIBILITÀ SOCIALE E DINAMICHE IMMOBILIARI
2017
Questo studio si propone di delineare una metodologia di valutazione dell’housing affordability alla scala territoriale, intesa come accessibilità finanziaria all’abitazione, in modo da ottenere un sistema di informazioni da impiegare a supporto del processo decisionale pubblico sulle politiche abitative. L’obiettivo, in particolare, è quello di individuare la domanda locale e i bisogni sociali corrispondenti alla distribuzione territoriale dei gap reddituali che impediscono l’accesso all’abitazione, in modo da intervenire con tutti gli strumenti che consentono di raggiungere una maggiore equità sociale. La metodologia procede attraverso lo studio della distribuzione territoriale della ricc…
Experimental Modeling of Submerged Pivot Weir
2020
An inclined rectangular overflow structure, also called a pivot weir, consists of a rectangular plate, angled downstream from the vertical, that can be used as an upstream water level control device. A pivot weir is submerged when the upstream water level is influenced by the downstream flow depth. In this paper, to investigate factors influencing submerged flow conditions, an extensive experimental program including 251 experimental trials was carried out using weir inclination angles of 39.6°, 53°, 85°, and 90° and weir heights ranging from 0.263 to 0.312 m. A formula to distinguish between free and submerged flow conditions was developed using the Π theorem of dimensional analysis and th…
Concise review of interrill erosion studies in SE Spain (Alicante and Murcia): erosion rates and progress of knowledge from the 1980s
2005
From the 1980s onward studies on interrill soil erosion were intensified in SE Spain. The main achievements of the research carried out in the field areas of Alicante and Murcia concern: first, (1) the estimation of erosion rates directly in the field under a wide range of methodologies, different scales and different environmental conditions; (2) estimations based on existing models, such as the USLE, carried out for different subcatchments of the Segura and Júcar catchments; and (3) other parametric and physical event-based models have also been calibrated and validated. Second, the progress of the knowledge in understanding erosion mechanisms. New and reviewed concepts regarding mainly h…
Predicting unit plot soil loss in Sicily, south Italy
2008
Predicting soil loss is necessary to establish soil conservation measures. Variability of soil and hydrological parameters complicates mathematical simulation of soil erosion processes. Methods for predicting unit plot soil loss in Sicily were developed by using 5 years of data from replicated plots. At first, the variability of the soil water content, runoff, and unit plot soil loss values collected at fixed dates or after an erosive event was investigated. The applicability of the Universal Soil Loss Equation (USLE) was then tested. Finally, a method to predict event soil loss was developed. Measurement variability decreased as the mean increased above a threshold value but it was low als…
Derivation of Rainfall Thresholds for Flash Flood Warning in a Sicilian Basin Using a Hydrological Model
2016
Abstract The damages caused by flash floods are among the most onerous in terms of loss of lives and damage to properties. Derivation of rainfall threshold is one of the approaches commonly used for the development of flash flood warning systems. Specifically, rainfall threshold is the rainfall amount that, for a given basin area and duration, is enough to cause flooding and, therefore, it indicates the maximal sustainable rainfall for a basin. The aim of this paper is deriving flash flood-rainfall thresholds for a Sicilian basin (Italy) throughout a deterministic approach. The conceptual hydrological model TOPDM was used to estimate the amount of rainfall that, for given duration, hydrolog…
A novel framework for MR image segmentation and quantification by using MedGA
2019
BACKGROUND AND OBJECTIVES: Image segmentation represents one of the most challenging issues in medical image analysis to distinguish among different adjacent tissues in a body part. In this context, appropriate image pre-processing tools can improve the result accuracy achieved by computer-assisted segmentation methods. Taking into consideration images with a bimodal intensity distribution, image binarization can be used to classify the input pictorial data into two classes, given a threshold intensity value. Unfortunately, adaptive thresholding techniques for two-class segmentation work properly only for images characterized by bimodal histograms. We aim at overcoming these limitations and…
Salivary protein profiles and sensitivity to the bitter taste of caffeine.
2011
WOS: 000298381900008; International audience; The interindividual variation in the sensitivity to bitterness is attributed in part to genetic polymorphism at the taste receptor level, but other factors, such as saliva composition, might be involved. In order to investigate this, 2 groups of subjects (hyposensitive, hypersensitive) were selected from 29 healthy male volunteers based on their detection thresholds for caffeine, and their salivary proteome composition was compared. Abundance of 26 of the 255 spots detected on saliva electrophoretic patterns was significantly different between hypo- and hypersensitive subjects. Saliva of hypersensitive subjects contained higher levels of amylase…