80 research outputs found
A new solution for mirror coating in -ray Cherenkov Astronomy
In the -ray Cherenkov Astronomy framework mirror coating plays a
crucial role in defining the light response of the telescope. We carried out a
study for new mirror coating solutions with both a numerical simulation
software and a vacuum chamber for small sample production. In this article, we
present a new mirror coating solution consisting of a 28-layer interferometric
SiO-TiO-HfO design deposited on a glass substrate, whose
average reflectance is above for normally incident light in the
wavelength range between 300 and 550 nm.Comment: 6 pages, 5 figures. Article submitted to Experimental Astronomy, the
final publication is available at link.springer.co
The Mirror Alignment and Control System for CT5 of the H.E.S.S. experiment
The High Energy Stereoscopic System (H.E.S.S.) experiment is one of the
largest observatories for gamma-ray astronomy. It consists of four telescopes
with a reflecting dish diameter of 12m (CT1 to CT4) and a newer large telescope
(CT5) with a reflecting dish diameter of 28m. On CT5 876 mirror facets are
mounted, all of them equipped with a computerised system for their alignment.
The design of the mirror alignment and control system and the performance of
the hardware installed to the telescope are presented. Furthermore the achieved
point spread function of the telescope over the full operational elevation
range as well as the stability of the alignment over an extended period of time
are shown
Treatment of Stifle Joint Luxation in a Cat Using a Temporary Trans-Articular Locking Plate
AbstractThe aim of this study was to report the surgical treatment of stifle joint luxation through temporary immobilization of the joint with locking plates in a cat. Stifle joint was immobilized using a temporary trans-articular locking plate applied medially. Return to function was assessed by physical and radiographic follow-up examinations. The cat had good return to function despite a reduction in range of motion. Moderate chronic gonarthritis developed, as seen radiographically. Under the limitation of this single case, temporary trans-articular plating may be considered as useful method for the treatment of long-standing, severely displaced stifle joint luxations in cats
Treatment of Y-T Humeral Fractures with Polyaxial Locking Plate System (PAX) in 14 Dogs
The aim of this study is to report the results and to review the outcome of 14 cases of Y-T humeral fractures repair using paired polyaxial locking system (PAX) plates through a combined medial and lateral approach. Fourteen consecutive dogs, with traumatic humeral Y-T fractures, met the inclusion criteria. This study includes signalment, preoperative radiographs, type of implants, radiographic bone healing assessment, complications, range of motion (ROM) of the elbow and limb function evaluated at 120 days after surgery. Postoperative radiographs revealed adequate anatomic reconstruction, and in all cases, bone healing has been achieved. No implant failure was observed. Functional outcome was excellent in 7 dogs (no lameness and preserved ROM), good in 4 (slight lameness and moderate ROM reduction) and discrete in 2 (mild lameness and severe ROM reduction). Complications were encountered in 2/14 patients with implant-associated infection resolved after long-term antibiotic treatment and implant removal. The PAX system is shown to be a valid alternative for the treatment of Y-T humeral fractures, offering the benefit of polyaxial insertion of locking screws. The possibility of angle locking screws is helpful in the distal humeral bicondylar fractures, providing additional options for screw placement in juxtarticular fractures, avoiding fracture lines or other implants
Investigation of Late-Quaternary sediments from the South Yellow Sea and the Yangtze River Delta (China)
The results of a study to determine the geochemical, mineralogical, magnetic and textural characteristics done on Late-Quaternary sediments from drill cores from the South Yellow Sea (core H106) and the Yangtze River Delta (core LA)
(China) are reported. The Late-Pleistocene continental sedimentation is represented by clayey silt and hard clay layers, while the marine Holocene sediments consist mainly of clay (H106) and sand and clay layers (LA)
Dal racconto al paesaggio. La narrazione come strumento progettuale nel recupero degli spazi agricoli di versante (Valtellina, Alpi centrali)
With the recent unfolding of several landscape recovery projects, the terraced
landscape of Media Valtellina (Central Alps, Lombardia) gained a crucial consideration
in the public discourse, both on a national and a transboundary, international level.
Such projects focus on restoring the traditional rural heritage, allowing a new wave of
agricultural and touristic initiatives to take place on the terraced slopes.
Relying on narrative interviews with key informants within the “Emblematici” project
framework, the essay explores the contemporary culture of the agricultural terracing in a
highly significant region. Our discourse embraces questions related to the symbolic and
cultural dimension of the terracing, the everyday labour the takes place on the slopes, the
future perspectives of the agricultural sector, and the constituent role of the abandonment
in the formation of the cultural landscape
MORPHODYNAMICS PROCESSES IN THE LAGOON OF VENICE: THE SCANELLO SALT MARSH AREA
Geomorpholgical variations have been naturally occurring in the Lagoon of Venice since its formation. In recent times, however, complex morphodynamic changes, caused by natural processes and by the direct or indirect impact of man activities have been recognised. Moreover, there remains a lack of knowledge concerning sediment erosion, re-suspension,
transport and sedimentation, sea-lagoon balance and the role played by the hydrodynamics.
A detailed study of the Scanello salt marsh area, in the Northern part of the Venice Lagoon, was carried out, in order to better understand the erosion-transport-sedimentation processes and the hydrodynamics interaction.
Understanding the role that the hydrodynamics plays in the erosion, transportation and deposition of sediments in this test area, is essential to the understanding the morphological variations, that are presently occurring in the Venice Lagoon and morphological and environmental restorations required. A 2D hydrodynamic finite element model was used to provide the circulation field of the entire Venice basin. Results obtained by different simulations allowed the investigation of the main hydrodynamic features of the Scanello area
Comparison between Areas of Bone Visualization Using Radiolucent Hybrid Fixator Frames and Graphically Simulated Metallic Frames: An Ex Vivo Study
The objective of this study is to evaluate the difference between the amount of bone visible with the superimposition of a radiolucent hybrid external fixator and a graphically simulated metallic frame. Eighteen frames were applied to eighteen bone specimens. The fracture area (FA), the radiolucent area (RLA) and the radiopaque area (ROA) inside the FA were calculated for each construct on both postoperative views. The ratio between the RLA and FA and between the ROA and FA was used to evaluate the amount of bone visible in the FA with a radiolucent and a radiopaque fixator, respectively. Finally, the areas of RLA and ROA were compared using the Wilcoxon test and Friedman test to evaluate the effect of the radiolucent material on the amount of bone visible. Differences were considered significant if p < 0.5. In every specimen p was <0.5. The amount of bone visible was significantly higher with the radiolucent frame compared to the radiopaque frame. Based on the results of this study, the use of radiolucent materials can be a valuable option for external fixation, in order to decrease the radiographic interference of the frame, allowing better assessment of fracture reduction and bone healing on postoperative radiographs
L’insostenibile leggerezza della sostenibilità: i limiti dell’attuale ecopolitica
‘Sustainability’ is a ubiquitous term within the political agenda worldwide. The
common recognition of such concept has its roots in the Seventies and is the
outcome of a cultural process which integrates the ‘limits to the (capitalistic)
growth’ in its paradigm. Notwithstanding, the consistency between ‘sustainability’
as a concept and its expected contents is doubtful. A trustful approach
towards the technical domain, together with the incorporation of ‘sustainability’
within the market mechanisms, have largely weakened the opportunity for the
concept to be disruptive on a political level, locally and globally. The relevant
distance between ‘sustainability’ as a term and its actual contents is the object
of the present proposal. The underlying ambiguity of the ‘Sustainable Development
Goals’ will be provided as a case-study for our critical review
Calixarenes Incorporating Sulfonamide Moieties: Versatile Ligands for Carbonic Anhydrases Inhibition
Carbonic anhydrases (CAs) continue to represent a relevant pharmaceutical target. The need of selective inhibitors and the involvement of these metalloenzymes in many multifaceted diseases boost the search for new ligands able to distinguish among the different CA isoforms, and for multifunctional systems simultaneously able to inhibit CAs and to interfere with other pathological events by interacting with additional targets. In this work, we successfully explored the possibility of preparing new CAs ligands by combining calixarenes with benzensulfonamide units. Inhibition tests towards three human CA isoforms evidenced, for some of the ligands, Ki values in the nanomolar range and promising selectivity. X-ray and molecular modeling studies provided information on the mode of binding of these calixarene derivatives. Thanks to the encouraging results and the structural features typical of the calixarene scaffold, it is then possible to plan for the future the design of multifunctional inhibitors for this class of widely spread enzymes
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