1,412 research outputs found

    \uabTransitoriet\ue0 e ritribalizzazione delle immagini nelle spaziazioni museali contemporanee\ubb

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    Parlare di spazio significa parlare di luoghi reali o immaginari, delle cose, delle azioni, delle parole, delle immagini o delle performance che a questi rimandano e viceversa. Il sistema dell\u2019arte occidentale, soprattutto negli ultimi due secoli, ha fatto dei musei i luoghi dell\u2019arte in senso stretto, della sua conservazione ed esposizione permanente. Eppure vanno considerate tutta una serie di pratiche artistiche che esulano lo spazio museale pur evocandolo in qualche modo. Si pensi alla Land Art, alle pitture rupestri del Paleolitico superiore, a certe opere d\u2019arte non occidentale come i Sand Paintings degli Indiani Navajo o degli Aborigeni Australiani dove l\u2019azione artistica (de)finisce lo spazio del paesaggio, e questo a sua volta comprende, orienta, influenza e sviluppa l\u2019azione artistica. Lo scopo di questo studio \ue8 di riflettere sul concetto di transitoriet\ue0 che contraddistingue certe azioni artistiche che vanno oltre il museo, che lo eccedono, e al contempo dimostrare come la stessa logica temporanea stia sempre pi\uf9 caratterizzando le forme, le dinamiche e le pratiche artistiche all\u2019interno degli spazi espositivi moderni (installazioni, foto e videoproiezioni, retrospettive). L\u2019idea \ue8 che l\u2019arte di passaggio nel paesaggio \u2012 realizzata da sempre da diverse societ\ue0 \u2012 si stia trasponendo come pratica artistica, come paradigma all\u2019interno dei musei occidentali che non sono pi\uf9 solo dei meri contenitori di oggetti e immagini, ma dei veri e propri atelier, teatri in azione dove artisti e/o curatori mettono in scena performance artistiche ed espositive istantanee. Lo spazio museale odierno sta subendo una sorta di \uabritribalizzazione artistica\ubb dove \ue8 facile osservare una corrispondenza antropologica tra l\u2019effimerit\ue0 delle azioni artistiche nel paesaggio e quella delle azioni artistiche nel museo. Quest\u2019ultimo diviene, in ultima analisi, terreno di ricerca, spazio da esplorare in senso etnografico

    ka band phase locked loop oscillator dielectric resonator oscillator for satellite ehf band receiver

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    This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB) for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very highQdielectric resonator

    AACVD synthesis of catalytic gold nanoparticle-modified cerium(IV) oxide thin films

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    Co-deposition of Ce(dbm)4 and NH4AuCl4 precursors in acetone at 500 °C via AACVD results in deposition of crystalline CeO2 thin films containing/decorated with metallic gold. These particles are estimated to be ∼ 70 nm in size via optical methods. Preliminary testing of catalytic activity showed the materials were surprisingly catalytically active given the very small amounts of gold present and the large estimated particle size, although the presence of smaller catalytically active particles could not be discounted

    Evaluation of the efficacy of animal-assisted therapy based on the reality orientation therapy protocol in Alzheimer's disease patients: a pilot study.

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    BACKGROUND: The aim of this study was to evaluate the efficacy of animal-assisted therapy (AAT) in elderly patients affected by Alzheimer's disease based on the formal reality orientation therapy (ROT) protocol. METHODS: Our study was carried out at an Alzheimer's centre for 6 months. A homogeneous sample (age, Mini-Mental State Examination (MMSE), 15-item Geriatric Depression Scale (GDS)) of 50 patients was selected at random and successively. Patients were divided into three groups: (i) 20 patients received a course of AAT (AAT group) based on the ROT protocol; (ii) 20 patients were engaged exclusively in activities based on the ROT group; and (iii) 10 patients (control group) participated in no stimulations. MMSE and GDS were administered at time 0 (T0 ) and time 1 (T1 ) to all three groups. Differences within groups between T0 and T1 for GDS and MMSE scores were analyzed by Student's t-test. Differences between group means were analyzed using an anova test with the Bonferroni-Dunn test for post-hoc comparisons. RESULTS: Both the AAT group and ROT group had improved GDS scores and showed a slight improvement in terms of mood. On the GDS, the AAT group improved from 11.5 (T0 ) to 9.5 (T1 ), and the ROT group improved from 11.6 (T0 ) to 10.5 (T1 ). At the same time, a slight improvement in cognitive function, as measured by the MMSE, was observed. In the AAT group, mean MMSE was 20.2 at T0 and 21.5 at T1 , and in the ROT group, it was 19.9 at T0 and 20.0 at T1 . In the control group, the average values of both the GDS and MMSE remained unchanged. The Bonferroni-Dunn results showed statistically significant differences between groups, particularly between the AAT group and the other two (P < 0.001). CONCLUSIONS: Pet therapy interventions based on the formal ROT protocol were effective and, compared to the ROT, provided encouraging and statistically significant results

    Distal ureteral stump: case report

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    Introdution. Distal Ureteral Stump is a residual ureter after total or partial nephrectomy. It is a rare complication and it also appears many years after surgery. Majority of patients are asymptomatic but Literature reports patients with recurrent bacteriuria or haematuria, empyema, stones and tumors (transitional-cell carcinoma or renal-cell carcinoma). We present one case of diseased ureteral stump and surgical strategy. Case Report. We report a case of a patient subjected to retroperitoneoscopic total nephrectomy when he was seven months old for sympthomatic right vesico-ureteral reflux of IV grade and associated renal hypoplasia. These patient presented recurrent urinary infections after 3 years from the surgery and for this reason we performed voiding micturating cystourethrography who revealed the presence of urinary reflux in the DUS. Because of this surgical removal of stump was necessary and during 2 months follow-up was normal and there weren’t surgical complications or UTI. Discussion. Distal Ureteral Stump is a rare complication but possible after nephrectomy and it is due to partial excision of ureter in the distal portion. Recurrent urinary infections are a usefull signal to subspect the presence of DUS and they are due to persistent reflux of urine and dysfunctional voiding (reservoir) resulting in stasis and infections. Therefore in all patients subjected to total or partial nephrectomy with recurrent urinary infections also after years, the presence of DUS should always be suspected and radiological investigation must be performed for accurate managemen

    Envelope analysis applied to non-Hertzian contact simulations in damaged roller bearings

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    In the latest years many researcher focused on the possibility to foresee the failure of a mechanical system in the early stages in order to allow quick response times. Monitoring and diagnostics are at the base of those methodologies of predictive maintenance, which represents the standard for companies. Data acquired by monitoring systems are sometimes not sufficient to perform an effective diagnosis and to detect failures. In the present work the possibility of a defining a relation between the response of a system and the dimension of a defect causing the vibration is explored. Through a non-Hertzian contact model a roller bearing is studied and a correlation is sought between the size of the defect and the frequency content of the contact pressure time history. Resorting to a non-Hertzian approach enables the determination with good accuracy of the overpressures due to edge effects caused by the sudden change in curvature in presence of a defect. The estimation of the pressure variation can be used to estimate the amplitude of the harmonic content exciting the bearing during operation. Using algorithms for the signal analysis already assessed in the literature, in particular the envelope method, an in-depth analysis of the harmonic content of the signal to consider is possible. The possibility of building a correlation between the load and the size of the defect which might help to identify the dimension of a damage from the estimated frequency content. It is then possible to identify the presence and nature of the defect, allowing an early diagnosis of the failure

    Health indicators construction for damage level assessment in bearing diagnostics: A proposal of an energetic approach based on envelope analysis

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    Predictive maintenance strategies are established in the industrial context on account of their benefits in terms of costs abatement and machine failures reduction. Among the available techniques, vibration-based condition monitoring (VBCM) has notably been applied in many bearing fault detection problems. The health indicators construction is a central issue for VBCM, since these features provide the necessary information to assess the current machine condition. However, the relation between vibration data and its sources intimately related to bearing damage is not effortlessly definable from a diagnostic perspective. This study discloses a diagnostic investigation performed both on the vibration signal and on the contact pressure signal that is supposed to be one of main forcing terms in the dynamic equilibrium of the damaged bearing. Envelope analysis and spectral kurtosis (SK) are applied to extract and compare diagnostic features from both signals, referring to the Case Western Reserve University (CWRU) case-study. Namely, health indicators are constructed by means of physical considerations based on the effect of faults on the signal power contents. These indicators show to be promising not only for damage detection but, also, for damage severity assessment. Moreover, they provide an invaluable reading key of the link occurring between the contact pressure path and the vibration response

    HYPERPLASIA OF THYMIC GLAND: LEFT VIDEO-ASSISTED THORACOSCOPIC APPROACH

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    Hyperplasia of thymic gland is a rare benign entity that should be considered in the differential diagnosis of anterior mediastinal masses in children and young adolescents. We report a case of a patient with a thymic mass, diagnosed occasionally for respiratory symptoms and treated by video-assisted thoracoscopic surgery. A previously healthy 10 years-old boy presented to our hospital for retrosternal pain and dyspnea with restriction to daily activities from four months. Diagnostic imaging was performed, including a chest x-ray and a magnetic resonance imaging, showing a large homogeneous anterosuperior mediastinal mass, more extended on the left side. The additional laboratory analysis, considered essential for differential diagnosis with myasthenia gravis and lymphoma, resulted negative. In view of these findings, our patient underwent to video assisted thoracoscopy with left-sided approach for a total resection of thymus and perithymic fat. The patient made an excellent recovery without postoperative complications and was discharged from the hospital four days later. Histopathological examination showed a normal thymic architecture like a true thymic hyperplasia. At follow up, chest x-ray was normal in absence of pleural and parenchimal alterations. Thoracoscopic thymectomy is a safe technique that allows to achieve the goal of early thymectomy with the advantages of less invasive procedure

    Aerosol-assisted CVD synthesis, characterisation and gas-sensing application of gold-functionalised tungsten oxide

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    Tungsten oxide nanoneedles (NNs) functionalised with gold nanoparticles (NPs) have been integrated with alumina gas-sensor platforms using a simple and effective co-deposition method via aerosol-assisted chemical vapour deposition (AACVD) utilising a novel gold precursor, (NH4)AuCl4. The gas-sensing results show that gold NP functionalisation of tungsten oxide NNs improves the sensitivity of response to ethanol, with sensitivity increasing and response time decreasing with increasing amount of gold
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