On localization and position operators in Moebius-covariant theories

Some years ago it was shown that, in some cases, a notion of locality can arise from the group of symmetry enjoyed by the theory, thus in an intrinsic way. In particular, when Moebius covariance is present, it is possible to associate some particular transformations to the Tomita Takesaki modular operator and conjugation of a specific interval of an abstract circle. In this context we propose a way to define an operator representing the coordinate conjugated with the modular transformations. Remarkably this coordinate turns out to be compatible with the abstract notion of locality. Finally a concrete example concerning a quantum particle on a line is also given.Comment: 19 pages, UTM 705, version to appear in RM

Gas Turbines for Power Generation on Board of Cruise Ships: A Possible Solution to Meet the New IMO Regulations?

AbstractIn order to reduce the environmental impact caused by merchant ships, the International Maritimes Organization is imposing new and stricter regulations on NOx and SOx emissions. Therefore, ships propelled by Internal Combustion Engines (ICEs) burning HFO must adopt abatement devices or switch to a cleaner fuel such as MGO. If the use of MGO is considered, a further and more drastic modification of the power system can be analyzed, namely the use of Gas Turbines (GTs) in place of ICEs. GTs are an attractive solution thanks to a reduced weight, size and NOx emissions, but are penalized by a lower electric efficiency. The case of a real cruise ship is considered in the present paper and a detailed quantification of the above mentioned differences is provided by simulating the ship operation for a reference trip

Evaluation of gas turbines as alternative energy production systems for a large cruise ship to meet new maritime regulations

As a consequence of the new and up-coming regulations imposed by the International Maritime Organization (IMO), polluting emissions produced by large ships are now under strict control. Moreover, specific areas called \u201cEmission Controlled Area\u201d (ECA), which request even lower pollutant emissions, will be extended. To face up to this issue, ships propelled by Internal Combustion Engines (ICEs) burning Heavy Fuel Oil (HFO) can be equipped with abatement devices such as scrubbers and Selective Catalytic Reactor systems. Along with these solutions, which seem to be the route ship-owners will prefer, other methods can be considered, such as the use of Marine Gas Oil (MGO): a more expensive fuel, but with lower sulphur content. The use of MGO allows users to consider a further and more drastic modification of the power system, namely the use of Gas Turbines (GTs) in place of ICEs. GTs, despite being less efficient, are much lighter, more compact, and can more easily reach low NOx emissions than ICEs. Even if these aspects are theoretically well known, there are still difficulties in finding studies reporting quantitative analysis (weight, dimensions, fuel consumption) that compare GT and ICE power systems employed on board. The present paper aims to provide these data by analyzing different solutions applied to a real case. Unlike other studies, the work is focused on a cruise ship rather than on a cargo ship, because a cruise ship's operation profile is more variable during the trip

u-RANIA: a neutron detector based on \mu -RWELL technology

In the framework of the ATTRACT-uRANIA project, funded by the European Community, we are developing an innovative neutron imaging detector based on micro-Resistive WELL ($\mu$ -RWELL) technology. The $\mu$ -RWELL, based on the resistive detector concept, ensuring an efficient spark quenching mechanism, is a highly reliable device. It is composed by two main elements: a readout-PCB and a cathode. The amplification stage for this device is embedded in the readout board through a resistive layer realized by means of an industrial process with DLC (Diamond-Like Carbon). A thin layer of B$_4$C on the copper surface of the cathode allows the thermal neutrons detection through the release of $^7$Li and $\alpha$ particles in the active volume. This technology has been developed to be an efficient and convenient alternative to the $^3$He shortage. The goal of the project is to prove the feasibility of such a novel neutron detector by developing and testing small planar prototypes with readout boards suitably segmented with strip or pad read out, equipped with existing electronics or readout in current mode. Preliminary results from the test with different prototypes, showing a good agreement with the simulation, will be presented together with construction details of the prototypes and the future steps of the project.Comment: Prepared for the INSTR20 Conference Proceeding for JINS

Dilated Cardiomyopathy With Mid-Range Ejection Fraction at Diagnosis: Characterization and Natural History

Background Limited data are available on mid-range ejection fraction (mrEF) patients with dilated cardiomyopathy. We sought to define the characteristics, evolution, and long-term prognosis of dilated cardiomyopathy patients with mrEF at diagnosis. Methods and Results We analyzed all dilated cardiomyopathy patients consecutively evaluated in the Trieste Heart Muscle Disease Registry from 1988 to 2013. mrEF and reduced ejection fraction (rEF) were defined as baseline left ventricular (LV) ejection fraction values between 40% and 49% and <40%, respectively. All-cause mortality or heart transplantation, sudden cardiac death, or major ventricular arrhythmias were considered as outcome measures. Worsening LV ejection fraction (reduction to <40%) during follow-up was also considered to identify possible predictors of adverse remodeling. Among 812 enrolled patients, 175 (22%) presented with mrEF at presentation. At baseline, as compared with the rEF group, mrEF patients had lower rates of moderate-severe mitral regurgitation and restrictive LV filling pattern. During a median follow-up period of 120 (60-204) months, the mrEF group presented a lower rate of death/heart transplantation (9% versus 36%, P<0.001) and sudden cardiac death or major ventricular arrhythmias (4.5% versus 15%, P<0.001) than rEF patients. Moreover, 29 out of 175 mrEF patients (17%) evolved to rEF. Restrictive LV filling pattern emerged as the strongest predictor of rEF development following multivariable analysis. Conclusions mrEF identified a consistent subgroup of dilated cardiomyopathy patients diagnosed in an earlier stage with subsequent apparent better long-term evolution. However, 17% of these patients evolved into rEF despite the use of medical therapy. A baseline restrictive LV filling pattern was independently associated with subsequent evolution to rEF

The HADES RV Programme with HARPS-N at TNG XI. GJ 685 b: a warm super-Earth around an active M dwarf

Small rocky planets seem to be very abundant around low-mass M-type stars. Their actual planetary population is however not yet precisely understood. Currently several surveys aim to expand the statistics with intensive detection campaigns, both photometric and spectroscopic. We analyse 106 spectroscopic HARPS-N observations of the active M0-type star GJ 685 taken over the past five years. We combine these data with photometric measurements from different observatories to accurately model the stellar rotation and disentangle its signals from genuine Doppler planetary signals in the RV data. We run an MCMC analysis on the RV and activity indexes time series to model the planetary and stellar signals present in the data, applying Gaussian Process regression technique to deal with the stellar activity signals. We identify three periodic signals in the RV time series, with periods of 9, 24, and 18 d. Combining the analyses of the photometry of the star with the activity indexes derived from the HARPS-N spectra, we identify the 18 d and 9 d signals as activity-related, corresponding to the stellar rotation period and its first harmonic respectively. The 24 d signals shows no relations with any activity proxy, so we identify it as a genuine planetary signal. We find the best-fit model describing the Doppler signal of the newly-found planet, GJ 685\,b, corresponding to an orbital period $P_b = 24.160^{+0.061}_{-0.047}$ d and a minimum mass $M_P \sin i = 9.0^{+1.7}_{-1.8}$ M$_\oplus$. We also study a sample of 70 RV-detected M-dwarf planets, and present new statistical evidence of a difference in mass distribution between the populations of single- and multi-planet systems, which can shed new light on the formation mechanisms of low-mass planets around late-type stars.Comment: 18 pages, 13 figures, accepted for publication in A&

HADES RV Programme with HARPS-N at TNG. VII. Rotation and activity of M-Dwarfs from time-series high-resolution spectroscopy of chromospheric indicators

We aim to investigate the presence of signatures of magnetic cycles and rotation on a sample of 71 early M-dwarfs from the HADES RV programme using high-resolution time-series spectroscopy of the Ca II H & K and Halpha chromospheric activity indicators, the radial velocity series, the parameters of the cross correlation function and the V-band photometry. We used mainly HARPS-N spectra, acquired over four years, and add HARPS spectra from the public ESO database and ASAS photometry light-curves as support data, extending the baseline of the observations of some stars up to 12 years. We provide log(R'hk) measurements for all the stars in the sample, cycle length measurements for 13 stars, rotation periods for 33 stars and we are able to measure the semi-amplitude of the radial velocity signal induced by rotation in 16 stars. We complement our work with previous results and confirm and refine the previously reported relationships between the mean level of chromospheric emission, measured by the log(R'hk), with the rotation period, and with the measured semi-amplitude of the activity induced radial velocity signal for early M-dwarfs. We searched for a possible relation between the measured rotation periods and the lengths of the magnetic cycle, finding a weak correlation between both quantities. Using previous v sin i measurements we estimated the inclinations of the star's poles to the line of sight for all the stars in the sample, and estimate the range of masses of the planets GJ 3998 b and c (2.5 - 4.9 Mearth and 6.3 - 12.5 Mearth), GJ 625 b (2.82 Mearth), GJ 3942 b (7.1 - 10.0 Mearth) and GJ 15A b (3.1 - 3.3 Mearth), assuming their orbits are coplanar with the stellar rotation.Comment: 19 pages, 16 figures, 10 table

Accuracy of right atrial pressure estimation using a multi-parameter approach derived from inferior vena cava semi-automated edge-tracking echocardiography: a pilot study in patients with cardiovascular disorders

The echocardiographic estimation of right atrial pressure (RAP) is based on the size and inspiratory collapse of the inferior vena cava (IVC). However, this method has proven to have limits of reliability. The aim of this study is to assess feasibility and accuracy of a new semi-automated approach to estimate RAP. Standard acquired echocardiographic images were processed with a semi-automated technique. Indexes related to the collapsibility of the vessel during inspiration (Caval Index, CI) and new indexes of pulsatility, obtained considering only the stimulation due to either respiration (Respiratory Caval Index, RCI) or heartbeats (Cardiac Caval Index, CCI) were derived. Binary Tree Models (BTM) were then developed to estimate either 3 or 5 RAP classes (BTM3 and BTM5) using indexes estimated by the semi-automated technique. These BTMs were compared with two standard estimation (SE) echocardiographic methods, indicated as A and B, distinguishing among 3 and 5 RAP classes, respectively. Direct RAP measurements obtained during a right heart catheterization (RHC) were used as reference. 62 consecutive \u2018all-comers\u2019 patients that had a RHC were enrolled; 13 patients were excluded for technical reasons. Therefore 49 patients were included in this study (mean age 62.2\ua0\ub1\ua015.2\ua0years, 75.5% pulmonary hypertension, 34.7% severe left ventricular dysfunction and 51% right ventricular dysfunction). The SE methods showed poor accuracy for RAP estimation (method A: misclassification error, ME\ua0=\ua051%, R2\ua0=\ua00.22; method B: ME\ua0=\ua069%, R2\ua0=\ua00.26). Instead, the new semi-automated methods BTM3 and BTM5 have higher accuracy (ME\ua0=\ua014%, R2\ua0=\ua00.47 and ME\ua0=\ua022%, R2\ua0=\ua00.61, respectively). In conclusion, a multi-parametric approach using IVC indexes extracted by the semi-automated approach is a promising tool for a more accurate estimation of RAP

Central charges and boundary fields for two dimensional dilatonic black holes

In this paper we first show that within the Hamiltonian description of general relativity, the central charge of a near horizon asymptotic symmetry group is zero, and therefore that the entropy of the system cannot be estimated using Cardy's formula. This is done by mapping a static black hole to a two dimensional space. We explain how such a charge can only appear to a static observer who chooses to stay permanently outside the black hole. Then an alternative argument is given for the presence of a universal central charge. Finally we suggest an effective quantum theory on the horizon that is compatible with the thermodynamics behaviour of the black hole.Comment: 16 pages, no figures, LaTex 2e, references adde