Voyage et \ue9criture dans le 'Journal' de Julien Green

Abstract Il lavoro analizza il Journal dello scrittore franco-americano nonch\ue9 accademico di Francia Julien Green e il rapporto che instaura tra la scrittura del diarista e quella del romanziere, visto attraverso l\u2019importanza accordata dall\u2019autore al viaggio. Attraverso un genere di tipo autobiografico che presenta le caratteristiche tipiche del genere, Green viaggiatore infatti d\ue0 vita a una descrizione dei luoghi visitati dominata da un immaginario ricco e vario che richiama e amplifica quello dei suoi romanzi: le annotazioni sul viaggio fanno cos\uec comprendere che lo spostamento materiale non \ue8 altro per lui che l\u2019erranza dell\u2019uomo teso a capire se stesso : la contemplazione del mondo cos\uec, attraverso il sogno e l\u2019estasi, si trasforma in una r\ueaverie che annulla il presente e immette il viaggiatore in uno spazio-tempo immemoriale che meglio risponde all\u2019inquietudine del viaggiatore, in un atteggiamento che \ue8 tipico della personalit\ue0 dello scrittore. Il rapporto che si instaura tra la visione del mondo resa possibile dal viaggio e la sua annotazione quotidiana diventa cos\uec essenziale: all\u2019inquietudine che \ue8 all\u2019origine dell\u2019erranza dell\u2019uomo risponde l\u2019attivit\ue0 dell\u2019artista la cui scrittura diventa lo strumento indispensabile per giungere a quella stabilit\ue0 da sempre cercata. Le annotazioni del viaggiatore raccontano la sua passione e la sua curiosit\ue0 per le bellezze del mondo, ma con la scrittura egli pu\uf2 abbandonarsi anche ad altri viaggi e inoltrarsi su quei percorsi immaginari che meglio rispondono alle sue esigenze interiori

Long-term prediction of adherence to continuous positive air pressure therapy for the treatment of moderate/severe obstructive sleep apnea syndrome

BACKGROUND: Continuous positive airway pressure (CPAP) therapy is a highly effective treatment for obstructive sleep apnea syndrome (OSAS). However, poor adherence is a limiting factor, and a significant proportion of patients are unable to tolerate CPAP. The aim of this study was to determine predictors of long-term non-compliance with CPAP. METHODS: CPAP treatment was prescribed to all consecutive patients with moderate or severe OSAS (AHI ≥15 events/h) (n = 295) who underwent a full-night CPAP titration study at home between February 1, 2002 and December 1, 2016. Adherence was defined as CPAP use for at least 4 h per night and five days per week. Subjects had periodical follow-up visits including clinical and biochemical evaluation and assessment of adherence to CPAP. RESULTS: Median follow-up observation was 74.8 (24.2/110.9) months. The percentage of OSAS patients adhering to CPAP was 41.4% (42.3% in males and 37.0% in females), and prevalence was significantly higher in severe OSAS than in moderate (51.8% vs. 22.1%; p < 0.001; respectively). At multivariate analysis, lower severity of OSAS (HR = 0.66; CI 95 0.46-0.94) p < 0.023), cigarette smoking (HR = 1.72; CI 95 1.13-2.61); p = 0.011), and previous cardiovascular events (HR = 1.95; CI 95 1.03-3.70; p = 0.04) were the only independent predictors of long-term non-adherence to CPAP after controlling for age, gender, and metabolic syndrome. CONCLUSIONS: In our cohort of patients with moderate/severe OSAS who were prescribed CPAP therapy, long-term compliance to treatment was present in less than half of the patients. Adherence was positively associated with OSAS severity and negatively associated with cigarette smoking and previous cardiovascular events at baseline

The effect of voltage distortion on ageing acceleration of insulation systems under partial discharge activity

The features of harmonic distortion which may affect significantly the reliability of typical ac-power network equipment, such as low-voltage self-healing capacitors used for reactive power and harmonic compensation are investigated. Moreover, the effect of high-frequency pulse-like voltage generated by adjustable speed drives (ASD) on electrical machine insulation is also investigated, resorting to life tests carried out on different insulating materials of the standard and "corona resistant" type, at electrical field levels able to incept partial discharges (PD)

Multiscale properties of polymeric insulating materials: from microscale polarizability to macroscale permittivity

This article presents an innovative and easy way for the calculation of the real part of permittivity for some of the most common insulating materials used for electrical applications, namely: polyethylene (PE), polypropylene (PP), polytetrafluorethylene (PTFE), ethylene-propylene diene monomer (EPDM), polyamide-imide (PAI), and epoxy resin (EP). This is achieved by the implementation and validation of the additivity approach for polarizability, along with the derivation of molecular volumes by means of chemical calculations involving real density of the considered materials. The proposed approach significantly reduces the computational time and effort for the calculation of macroscopic permittivity. Simulated values show good accordance with experimental results, thus validating the approach

Broadband dielectric spectroscopy: A viable technique for aging assessment of low-voltage cable insulation used in nuclear power plants

This paper deals with the study of a non-destructive technique to detect the aging state of cable insulation used in a nuclear environment subjected to radiation and temperature aging. Cable samples were aged under dose rates ranging from 0.42 and 1.06 kGy/h at 55 and 85 °C. The imaginary part of the permittivity at 100 kHz is found to correlate well with mechanical properties, such as elongation at break, which is typically used to diagnose cable insulation, but it is a destructive property and cannot be used on field. It has been demonstrated also that a postirradiation effect occurs even years after aging is stopped, increasing the imaginary permittivity and worsening mechanical properties due to the slow conversion of radicals into oxidized species. The main consequence is that when cable insulation is subjected to a nuclear accident, releasing a huge amount of radiation, the health of cable insulation must be followed also for a long time after the accident occurred, since aging due to oxidation progresses even when the radiation source is switched off

Additive impact on space charge of XLPE-based insulators subjected to radio-chemical aging

This work investigates the development of space charge distribution through by means of the pulsed-electroacoustic method on differently-filled XLPE tapes subjected to radiochemical aging. The contribution of these different fillers on the space charge distribution and its evolution with aging is highlighted and linked with the physical-chemical properties (e.g. oxidation degree) of these materials

Impact of additives and fillers on space charge behavior of polyethylene insulation: investigation and modeling

Diagnostic measurements on electrically insulating materials are a compulsory step to assure an acceptable service life of the electrical equipment. In particular, this paper focuses on the consequences of the implementation of several concentrations of antioxidants (Irganox® 1076 and Irganox® PSS02) inside Si-XLPE matrices. Thermally Stimulated Depolarization Current (TSDC) measurements were carried out on pure and filled samples to obtain information about the space charge behavior and trap distribution of the specimens. Postprocessing based on Randal-Wilkins model highlighted additive impact on Si-XLPE properties. Similar trap depth and different trap density values were found in samples with different concentrations of the same additive, suggesting a close correlation between the energy levels of localized states and the used antioxidants

Corona poling for polarization of nanofibrous mats: advantages and open issues

This paper deals with the polarization process of piezoelectric nanofibrous mats of PVdF-TrFE by using a corona discharge process. With respect to traditional contact poling this process reduces the electrical breakdown risk which could easily occur when a highly porous mat is placed between two solid electrodes. Different set-up configurations were investigated by varying the applied voltage and the distance between the needle and the sample. The polarized nanofibers show a piezoelectric strain coefficients (mathrmd_33) comparable with the values of a commercial stiff film

Analysis on the impact of additives on space charge behavior of thermally aged XLPE plaques

This article investigates the space charge properties of XLPE-based materials characterized by different concentration and types of additives and fillers inside the polymeric compound. Materials were aged under three different temperatures (87 °C, 110 °C and 130 °C) for 24, 18 and 12 months, respectively. Space charge profiles of both unaged and aged materials were obtained through the Pulsed Electro Acoustic (PEA) method. Additives and fillers are proven to significantly impact the space charge behavior of the insulating material both in the unaged and aged states. The impact of antioxidants, together with their kinetics under thermal aging conditions, is analyzed and claims an effective containment of the degradation kinetics, keeping the accumulated space charge to low values

Effects of Graphene Coatings on hindering Space Charge injection in Epoxy Resin

The reliability of epoxy resins (and dielectrics in general) employed for HVDC applications is significantly affected by space charge accumulation in the insulating material. Several methods have been tested to limit the injection and accumulation of space charge. In this work, planar specimens featuring graphene coatings were tested. Measurements of space charge accumulation, conductivity and permittivity at different temperatures (from 30°C to 60°C) and fields (from 30 kV/mm to 50 kV/mm) were carried out on epoxy specimens with and without coatings. Results show accumulation of space charge for low fields and temperatures in the reference specimens, while a reduction can be noticed with a layer of graphene coating. On the other hand, at higher fields or temperatures, the effect is reversed