1,722,144 research outputs found
Electromagnetic signals from bare strange stars
Full text linkStrange stars with a crystalline color superconducting crust can sustain large shear stresses, supporting torsional oscillations of large amplitude. We consider a simple model of strange star with a bare quark matter surface. When a torsional oscillation is excited, for example by a stellar glitch, the positive charge at the star surface oscillates, with typical kHz frequencies, for a 1km thick crust, to hundreds of Hz, for a 9km thick crust. Higher frequencies, of the order of few GHz, can be reached if the star crust is of the order of few centimeters thick. The estimated emitted power is of the order of 1045 erg/s
Transverse myelitis associated with Mycoplasma pneumoniae pneumonitis: a report of two cases
No full textThe authors report two cases of transverse myelitis due to Mycoplasma pneumoniae occurring during a recent acute infection due to Epstein-Barr virus (EBV). The clinical picture included weakness of the legs, bladder dysfunction, fever, headache and in one case, a mild confusional state. Magnetic Resonance Imaging (MRI) revealed a segmental edema of the lumbar tract and cerebro-spinal fluid analysis showed a mild pleocytosis and an increased level of proteins with a blood-brain barrier damage. The diagnosis of acute infection due to Mycoplasma pneumoniae was made on serological criteria. The patients recovered completely after a 14-day course of an associated regimen with Ciprofloxacin (400 mg/day i.v.) plus prednisone (60 mg/day i.v.). The authors emphasise the immunological disorders in the combined infection with Mycoplasma pneumoniae and EBV, supposing that an infective mononucleosis may predispose to mycoplasmic transverse myelitis
An analytical model-based assessment of Wet Electrostatic Scrubbing for mitigating fine and ultrafine particles emissions in domestic biomass boilers
Full text linkThis paper proposes the general design of a Wet Electrostatic Scrubber aimed at mitigating fine and ultrafine particles emissions from domestic heating boilers. The design is based on particle capture modelling supported by specific experiments and technical literature information. Results indicate up to 96.6% removal efficiency, consuming 1.2 kg/h of water and 0.3 W per 1 m3/h of gas treated. Comparative analysis highlights the balanced performance of Wet Electrostatic Scrubber in particle capture, energy and water usage, pressure drop, and space occupancy, with the additional benefit of more efficient absorption of gas pollutants
Self-affine properties of fractures in brittle materials
No full textWe present the result of numerical simulations for a fracturing process in a three-dimensional solid subjected to a mode-I load in a quasi-static regime. The solid is described using the Born model on an FCC lattice with a starting notch. We obtain a value of the roughness exponent ζ≈0.5 in agreement with the value measured in microfracturing experiments. Our result supports the idea that at small length scales the fracturing process can be considered as quasi-static, which is the basic of the possible application of the model of line depinning to the case of fractures
La realtà giuridica delle unioni civili.
No full textLa vicenda giuridica delle unioni di fatto si svolge per lungo tempo ai margini del diritto di famiglia, rectius, della famiglia legittimamente costituita, nel trascorrere dell’interprete dalla suggestione del ricorso all’applicazione analogica di norme afferenti ad istituti consolidati ed il ritrarsi dalle regole tradizionali per porre mente al momento negoziale e alle norme pattizie.
Il vivere stabilmente insieme è la base comune tanto del vincolo coniugale - regno indiscusso degli status, strutturato globalmente nella fase della formazione, nella sua funzionalità quale rapporto e nelle finalità specifiche e peculiari connesse alla sua esistenza - quanto delle unioni di fatto, genus per lungo tempo indistinto tranne che per il suo collocarsi, di là dagli spazi di ingerenza dei pubblici poteri, nell’ambito della autoregolamentazione privata e della libera espressione della volontà dei contraenti.
Attraverso il succedersi di provvedimenti normativi, per lo più nelle forme di novellazione del codice civile, il diritto quasi impercettibilmente è entrato nella materia senza invadere, affiancando progressivamente alla figura del coniuge quella del convivente tout court: rilevava, ormai, sia a livello sociale che a livello politico, l’esigenza generalizzata di definire le coordinate giuridiche del fenomeno, oltre che di delinearne l’esattezza del connotato semantico.
Il legislatore di più ordinamenti sembra aver condiviso il disagio di strutturare giuridicamente una figura multiforme - seppure incentrata sulla stabile convivenza -, dimidiata tra istanze opposte di autonomia e disciplina, nell’intento di sottrarla, comunque, all’inaccettabile dimensione dell’arbitrarietà.
Conciliare, dunque, l’intrinseca pretesa di autonomia della fattispecie e le sue indiscusse esigenze di tutela, a pena di disattendere il rispetto di diritti e valori fondamentali, era impegno improcrastinabile, soprattutto per il legislatore italiano, al di là delle sollecitazioni della Corte Costituzionale e degli arresti dei giudici di Strasburgo
Stress-Prediction Model for Airport Pavements with Jointed Concrete Slabs
No full textAbstract: Two specific three-dimensional finite-element models are presented for making an evaluation of the maximum
stresses at critical locations in concrete slabs i.e., at the interior and edge that is superior to the classic approach of the
approximate methods. Concrete airport pavements with square-shaped slabs are studied. A homogeneous, isotropic elastic
half-space is assumed as a subgrade foundation model so that the influence of variation in Young’s modulus is examined in
contrast with Winkler’s reaction modulus. The effects of two aircrafts A380 and B747, different subgrade bearing capabilities
and temperature gradients Δt, are investigated. Combined stresses due to aircraft load and temperature gradient Δt are
accurately estimated by means of a finite-element software and compared to their separate actions. As a consequence the
incorrect applicability of the principle of effects superposition, which is due to the support soil that is non resistant to tensile
stress, is quantified. Moreover, the difference in the values of the stresses due to the two different aforementioned aircrafts is
calculated. A simplified method for predicting maximum stresses is also derived from the results of the finite-element
software. This predictive method represents a useful tool for a faster estimation of stresses at a preliminarily design level. The
proposed equations make adjustments to Westergaard’s load stress model and Eisenmann’s temperature stress model
necessary, as they also do for the separate actions of load and Δt. The procedure makes use of dimensionless variables so that
it may also be extended to different square-slab dimensions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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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