814 research outputs found
Laser Scanner 3D per lo studio e la catalogazione dell’archeologia medievale: la chiesa di Santa Croce in Bergamo
The improvement of new active optical sensors has revolutionized the methods for documenting cultural heritage. The conservation and appreciation of our cultural legacy re¬quire an extensive documentation both in terms of shape, color and geometry as well as the more traditional art-historical features. The incessant development of scientific research today provides new possibilities and tools which are essential to know and use in a responsible and scientific way. In the field of archaeology, the automatic 3D survey is now recognized as an added value compared to traditional practices and the active contribution that this technology can provide to the interpretative phase, cataloguing and promotion of archaeological assets, even through the web, is becoming increasingly clear. On the other hand, even considering the speed of the procedure and the accuracy of measurement, there have been calls for reflection on the role that laser scanning can play in the field of archaeology; this role needs to be clarified and consolidated by conducting new studies and experiments, such as the one presented here that concerns the Church of Santa Croce in Bergamo, a small octagonal Romanesque chapel built in the first half of the 11th century
Update On The Code Intercomparison and Benchmark For Muon Fluence and Absorbed Dose Induced By An 18-GeV Electron Beam After Massive Iron Shielding
In 1974, Nelson, Kase and Svensson published an experimental investigation on
muon shielding around SLAC high-energy electron accelerators. They measured
muon fluence and absorbed dose induced by 14 and 18 GeV electron beams hitting
a copper/water beamdump and attenuated in a thick steel shielding. In their
paper, they compared the results with the theoretical models available at that
time.
In order to compare their experimental results with present model
calculations, we use the modern transport Monte Carlo codes MARS15, FLUKA2011
and GEANT4 to model the experimental setup and run simulations. The results are
then compared between the codes, and with the SLAC data.Comment: 14 pp. Presented paper at the 13th Meeting of the task-force on
Shielding aspects of Accelerators, Targets and Irradiation Facilities
(SATIF-13), HZDR, October 10-12, 2016, Dresden, Germany. arXiv admin note:
substantial text overlap with arXiv:1502.0168
Acute Treatment with Renal Denervation in a Patient with Resistant Hypertension and Hemorrhagic Stroke
A 49-year-old man with refractory hypertension was admitted
to our hospital in a coma caused by hemorrhagic stroke. Severe
hypertension was observed during hospitalization despite a full
antihypertensive therapy. Considering the risk of enlargement of
the intracranial hematoma, the decision was made to perform renal
denervation (RDN). A significant blood pressure reduction was
obtained after RDN. The patient had a progressive improvement of
general conditions and came out of the coma after a few days. This
case underlines the safety and the feasibility of RDN in a critically
ill patient
Percutaneous coronary intervention driven by combined use of intracoronary anatomy and physiology Towards a tailored therapy for coronary artery disease
Coronary angiography classically allows a bidimensional evaluation
of the vascular lumen, however with many limitations in the case of eccentric
lesions, irregular contour or tortuosity of the vessel.Moreover, it
does not enable to assess neither the features of the vessel wall, nor the
functional significance of a lesion [1]. Newer technologies are available
to overcome these limitations.We present a case of percutaneous coronary
revascularization optimized by combined use of two of the most
widely used techniques
Processor Allocation for Optimistic Parallelization of Irregular Programs
Optimistic parallelization is a promising approach for the parallelization of
irregular algorithms: potentially interfering tasks are launched dynamically,
and the runtime system detects conflicts between concurrent activities,
aborting and rolling back conflicting tasks. However, parallelism in irregular
algorithms is very complex. In a regular algorithm like dense matrix
multiplication, the amount of parallelism can usually be expressed as a
function of the problem size, so it is reasonably straightforward to determine
how many processors should be allocated to execute a regular algorithm of a
certain size (this is called the processor allocation problem). In contrast,
parallelism in irregular algorithms can be a function of input parameters, and
the amount of parallelism can vary dramatically during the execution of the
irregular algorithm. Therefore, the processor allocation problem for irregular
algorithms is very difficult.
In this paper, we describe the first systematic strategy for addressing this
problem. Our approach is based on a construct called the conflict graph, which
(i) provides insight into the amount of parallelism that can be extracted from
an irregular algorithm, and (ii) can be used to address the processor
allocation problem for irregular algorithms. We show that this problem is
related to a generalization of the unfriendly seating problem and, by extending
Tur\'an's theorem, we obtain a worst-case class of problems for optimistic
parallelization, which we use to derive a lower bound on the exploitable
parallelism. Finally, using some theoretically derived properties and some
experimental facts, we design a quick and stable control strategy for solving
the processor allocation problem heuristically.Comment: 12 pages, 3 figures, extended version of SPAA 2011 brief announcemen
Comparison between intermediate and severe coronary stenoses and clinical outcomes of an OCT-guided PCI strategy
We compared optical coherence tomography (OCT) features of intermediate and severe coronary stenoses in patients with stable angina and acute coronary syndrome (ACS), and tested the clinical impact of an OCT-based strategy for treating intermediate stenoses
Carotid artery stenting: a single-centre experience with up to 8 years' follow-up
Carotid artery stenting (CAS) may be an alternative to surgical endoarterectomy not only in high-risk patients. We report results in the endovascular treatment of carotid artery disease with up to 8 years' follow-up. In this retrospective study, we analysed data from 853 consecutive patients (946 arteries) treated for carotid artery stenosis between April 1999 and March 2007; 491 (52%) arteries were symptomatic and 455(48%) were asymptomatic. Preprocedural evaluation of the patients was performed with echo Doppler, magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) and a neurological examination. A cerebral protection device was used in 879 (92.9%) procedures. Anti-platelet therapy was administered before and after the procedure. All patients were included in a follow-up of up to 8 years. Technical success was achieved in 943 (99.6%) lesions. At 30 days, there was a 0.21% (n = 2) death rate, a 0.42% major stroke rate, a 1.69% minor stroke/transient ischaemic attack (TIA) rate and a combined 2.32% TIA/stroke and death rate. During follow-up, echo Doppler evidenced restenosis in 39 (4.85%) cases; of these, only five, presenting restenosis > 80%, were treated with an endovascular reintervention. At the long-term follow-up, two strokes (0.23%) were reported, which both occurred within the first 2 years. In our experience, carotid artery stenting seems to be a safe and effective treatment, providing satisfactory long-term clinical results
THE MAXXI MUSEUM IN ROME: AN INTEGRATED SURVEY EXPERIENCE FOR THE RESTORATION OF CONTEMPORARY ARCHITECTURE
In recent years, the fate of contemporary buildings in reinforced concrete is becoming a growing concern due to the fast ageing of structures, however, often of great architectural and social interest. The procedures to put in place for their material and structural preservation require multidisciplinary expertise, but also new methodological insights as most of these edifices are the result of pioneering experiments and individual ‘challenges’ from the morphological and technical point of views. They strictly depend on both the recognition of their peculiarities and the ability to differentiate their intrinsic characteristics of inhomogeneity from insecurity factors and degradation phenomena. This paper focuses on the experience undertaken on the MAXXI, the National Museum of the 21st century Arts, built by Zaha Hadid Architects in Rome to highlight the methodological process followed for the knowledge of this architectural work, in view of the establishment of the project for its conservation
Precision Measurement of KS Meson Lifetime with the KLOE detector
Using a large sample of pure, slow, short lived K0 mesons collected with KLOE
detector at DaFne, we have measured the KS lifetime. From a fit to the proper
time distribution we find tau = (89.562 +- 0.029_stat +- 0.043_syst) ps. This
is the most precise measurement today in good agreement with the world average
derived from previous measurements. We observe no dependence of the lifetime on
the direction of the Ks.Comment: 5 pages, 7 figure
Determination of CP and CPT violation parameters in the neutral kaon system using the Bell-Steinberger relation and data from the KLOE experiment
We present an improved determination of the CP and CPT violation parameters
Re(epsilon) and Im(delta) based on the unitarity condition (Bell-Steinberger
relation) and on recent results from the KLOE experiment. We find Re(epsilon) =
(159.6 \pm 1.3)10^-5 and Im(delta) = (0.4 \pm 2.1)10^-5, consistent with no CPT
violation.Comment: Submitted to JHE
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