Estimating Relevant Portion of Stability Region using Lyapunov Approach and Sum of Squares

Traditional Lyapunov based transient stability assessment approaches focus on identifying the stability region (SR) of the equilibrium point under study. When trying to estimate this region using Lyapunov functions, the shape of the final estimate is often limited by the degree of the function chosen, a limitation that results in conservativeness in the estimate of the SR. More conservative the estimate is in a particular region of state space, smaller is the estimate of the critical clearing time for disturbances that drive the system towards that region. In order to reduce this conservativeness, we propose a methodology that uses the disturbance trajectory data to skew the shape of the final Lyapunov based SR estimate. We exploit the advances made in the theory of sum of squares decomposition to algorithmically estimate this region. The effectiveness of this technique is demonstrated on a power systems classical model.Comment: Under review as a conference paper at IEEE PESGM 201

Estimating Spatial Econometrics Models with Integrated Nested Laplace Approximation

Integrated Nested Laplace Approximation provides a fast and effective method for marginal inference on Bayesian hierarchical models. This methodology has been implemented in the R-INLA package which permits INLA to be used from within R statistical software. Although INLA is implemented as a general methodology, its use in practice is limited to the models implemented in the R-INLA package. Spatial autoregressive models are widely used in spatial econometrics but have until now been missing from the R-INLA package. In this paper, we describe the implementation and application of a new class of latent models in INLA made available through R-INLA. This new latent class implements a standard spatial lag model, which is widely used and that can be used to build more complex models in spatial econometrics. The implementation of this latent model in R-INLA also means that all the other features of INLA can be used for model fitting, model selection and inference in spatial econometrics, as will be shown in this paper. Finally, we will illustrate the use of this new latent model and its applications with two datasets based on Gaussian and binary outcomes

Le comunità di fillominatori e parassitoidi della Riserva Naturale “Bosco d’Alcamo” (Sicilia)

È stata studiata la comunità di fillominatori e parassitoidi su 16 specie di piante spontanee della Riserva Naturale “Bosco d’Alcamo”. Sono state rinvenute 17 specie di Lepidoptera e 7 specie di Diptera. Da queste sono sfarfallate circa 20 specie di parassitoidi, perlopiù rappresentate da Eulophidae e Braconidae. Viene confermata la presenza in Sicilia del Gracillariidae Phyllonorycter trifasciella Haworth e dell’Eulophidae Derostenus gemmeus Westwood. Per la prima volta Sympiesis notata (Zetterstedt) e Cirrospilus viticola (Rondani) sono stati rinvenuti come parassitoidi di Emme- tia marginea (Haworth). Inoltre S. notata è stata rinvenuta anche come parassitoide di P. trifasciella. Nel complesso viene confermato il ruolo importante dei boschi naturali, soprattutto querceti, come riserva di entomofauna e di diversità biologica.Leafminer and parasitoid community of the Nature Reserve “Bosco d’Alcamo” (Sicily). The leafminer and parasitoid communities of the Nature Reserve “Bosco D’Alcamo” was studied on 16 spontaneous plants. 17 Lepidoptera and 7 Diptera species were detected. About 20 parasitoid species emerged mainly represented by Eulophidae and Braconidae. The presence in Sicily of the Gracillariidae Phyllonorycter trifasciella Haworth was confirmed, as well as that of Eulophidae Derostenus gemmeus Westwood. Sympiesis notata (Zetterstedt) and Cirrospilus viticola (Rondani) were recorded for the first time as parasitoid of Emmetia marginea (Haworth). S. notata was record- ed also as a new parasitoid of P. trifasciella. The important role of natural woods, especially oaks, as reservoir of entomofauna and biodiversity was confirmed

Spin-dependent direct gap emission in tensile-strained Ge films on Si substrates

The circular polarization of direct gap emission of Ge is studied in optically-excited tensile-strained Ge-on-Si heterostructures as a function of doping and temperature. Owing to the spin-dependent optical selection rules, the radiative recombinations involving strain-split light (cG-LH) and heavy hole (cG-HH) bands are unambiguously resolved. The fundamental cG-LH transition is found to have a low temperature circular polarization degree of about 85% despite an off-resonance excitation of more than 300 meV. By photoluminescence (PL) measurements and tight binding calculations we show that this exceptionally high value is due to the peculiar energy dependence of the optically-induced electron spin population. Finally, our observation of the direct gap doublet clarifies that the light hole contribution, previously considered to be negligible, can dominate the room temperature PL even at low tensile strain values of about 0.2%

First data on the repellent activity of essential oils of Citrus limon towards medfly (Ceratitis capitata)

The biological activity of peel essential oils of two Sicilian cultivars of C. limon, ‘Interdonato’ and ‘Lunario’, was investigated by electrophysiological recordings (EAG) and field trials on Ceratitis capitata (Wiedemann) (Diptera Tephritidae). The EAG data showed a remarkable dose-response relationship and a low activation threshold dose (10-3M) for both essential oil extracts. In field tests, essential oils showed a good repellent and antiovipositional activi- ty on ‘Navelina’ oranges, and in particular the essential oils of ‘Lunario’ pro- vided the same results of kaolin. Potential applications of essential oils from C. limon cultivars against C. capitata in organic farming are discussed

A review of the current knowledge on Zeugodacus cucurbitae (Coquillett) (Diptera, Tephritidae) in Africa, with a list of species included in Zeugodacus

Published online 2015 Nov 26This paper reviews all available information regarding the occurrence and biology of the melon fly, Zeugodacus cucurbitae (Coquillett), in the Afrotropical Region, including data on invasion history, distribution patterns, population genetics, host range, and interspecific competition. Although limited intraspecific variability has been observed within the region regarding the above mentioned aspects, there seems to be no indication that Zeugodacus cucurbitae represents a species complex. A checklist of all of the species included in Zeugodacus as recently proposed by Virgilio et al. (2015) is provided

Beam test calibration of the balloon-borne imaging calorimeter for the CREAM experiment

CREAM (Cosmic Ray Energetics And Mass) is a multi-flight balloon mission designed to collect direct data on the elemental composition and individual energy spectra of cosmic rays. Two instrument suites have been built to be flown alternately on a yearly base. The tungsten/Sci-Fi imaging calorimeter for the second flight, scheduled for December 2005, was calibrated with electron and proton beams at CERN. A calibration procedure based on the study of the longitudinal shower profile is described and preliminary results of the beam test are presented.Comment: 4 pages, 4 figures. To be published in the Proceedings of 29th International Cosmic Ray Conference (ICRC 2005), Pune, India, August 3-10, 200

Biological activity of metabolites extracted from Citrus spp. on Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

The Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most injurious pest at global level. During the last years, several electrophysiological and behavioural studies have been carried out in order to investigate plant volatile compound-insect interactions with the aim to use this knowledge in sustainable control techniques. It has been observed that lemons are not attacked by medfly, probably because of the peel oil, that is toxic to other fruit flies. In the present paper electrophysiological recordings were conducted to evaluate the insect sensitivity to peel extract and peel oil of two Sicilian cultivars (Interdonato and Lunario) of Citrus x limon (L.) Burm.f. on C. capitata females. Behavioural bioassays were also performed to show their possible biological activity (repellent, antioviposition, insecticidal). C. limon peel extracts in different solvents (petroleum ether, dichloromethane and methanol) were investigated at various concentrations using a single cell recording technique (stimulation of tarsal taste chemosensilla). Different tarsal taste cell responses to the two cultivars were recorded. The higher sensitivity was evoked by C. limon Interdonato, particularly to the methanol extract, which elicited significant increases in the spike frequency at increasing concentrations. The peel oil of the same cultivars as well as that ones of other two C. limon varieties (Monachello and Femminello) have been tested by EAG techniques. The EAG data showed a high sensitivity (about -8.0/8.5mV) of the medfly antennae to the oils of Citrus spp. and a clear dose-response relationship. Responses of adult females (virgin and mated) to Citrus spp. peel extract were quantified in a double-choice test using yellow spheres (diameter 7.0cm) housed in field cages. Preliminary tests conducted on three extracts of C. limon Interdonato and Lunario have provided interesting results. It was recorded a general decrease of the oviposition on treated spheres compared to control and in the case of the cultivar Lunario, a mortality of insects