The discrimination problem for two ground states or two thermal states of the quantum Ising model

We address the one-dimensional quantum Ising model as an example of system exhibiting criticality and study in some details the discrimination problem for pairs of states corresponding to different values of the coupling constant. We evaluate the error probability for single-copy discrimination, the Chernoff bound for $n$-copy discrimination in the asymptotic limit, and the Chernoff metric for the discrimination of infinitesimally close states. We point out scaling properties of the above quantities, and derive the external field optimizing state discrimination for short chains as well as in the thermodynamical limit, thus assessing criticality as a resource for quantum discrimination in many-body systems.Comment: revised version, title changed, 4 fig

Effect of noise and enhancement of nonlocality in on/off photodetection

Nonlocality of two-mode states of light is addressed by means of CHSH inequality based on displaced on/off photodetection. Effects due to non-unit quantum efficiency and nonzero dark counts are taken into account. Nonlocality of both balanced and unbalanced superpositions of few photon-number states, as well as that of multiphoton twin beams, is investigated. We find that unbalanced superpositions show larger nonlocality than balanced one when noise affects the photodetection process. De-Gaussification by means of (inconclusive) photon subtraction is shown to enhance nonlocality of twin beams in the low energy regime. We also show that when the measurement is described by a POVM, rather than a set of projectors, the maximum achievable value of the Bell parameter in the CHSH inequality is decreased, and is no longer given by the Cirel'son bound.Comment: 21 Figure

Investment and risk appraisal in Energy Storage Systems: a real options approach

The increasing penetration of variable renewable energy is becoming a key challenge for the management of the electrical grid. Electrical Energy Storage Systems (ESS) are one of the most suitable solutions to increase the flexibility and resilience of the electrical system. This paper presents an innovative methodology for the appraisal of the investment in ESS. The methodology is based on the Real Option Analysis and it is able to properly consider investment risks and uncertainties as well as the options available for the investor. The paper assesses the value of the option to wait for a change in the market conditions before investing and re-evaluates the profitability of the investment after each step of the development of the ESS project. In order to exemplify relevant results, this method is applied to the UK energy market and assesses the technical and economic feasibility of investing in ESS operating price arbitrage and Short Term Operating Reserves. The results show that the implementation of the Real Option Analysis increases the economic performance of ESS. Nevertheless, ESS still requires limited incentives to be economically viable

A methodology based on benchmarking to learn across megaprojects: the case of nuclear decommissioning

Purpose: The literature lacks a single and universally accepted definition of major and megaprojects: usually, these projects are described as projects with a budget above $1 billion and a high level of innovation, complexity & uniqueness both in terms of physical infrastructure and stakeholder network. Moreover, they often provide fewer benefits than what were originally expected and are affected by delays and cost overruns. Despite this techno-economic magnitude, it is still extremely hard to gather lessons learned from these projects in a systematic way. This paper presents an innovative methodology based on benchmarking to investigate good and bad practices and learn from a portfolio of unique megaprojects. Design/methodology/approach: The methodology combines quantitative & qualitative cross-comparison of case studies and statistical analysis into an iterative process. Findings: Indeed, benchmarking offers significant potential to identify good and bad practices and improve the performance of project selection, planning and delivery. Research limitations/implications: The methodology is exemplified in this paper using the case of Nuclear Decommissioning Projects and Programmes (NDPs). Originality/value: Indeed, due to their characteristics, NDPs can be addressed as megaprojects, and are a relevant example for the application of the methodology presented here that collects and investigates the characteristics that mostly impact the performance of (mega)projects, through a continuous learning process

Optical coherence tomography and optical coherence tomography angiography in uveitis : a review

Optical coherence tomography (OCT) has dramatically changed the understanding and management of uveitis and other ocular conditions. Currently, OCT angiography (OCTA) combines structural information with the visualization of blood flow within the imaged area. The aim of this review is to present the basic principles of OCT and OCTA interpretation and to investigate the role of these imaging techniques in the diagnosis and management of uveitis. Common complications of intraocular inflammation such as macular oedema and inflammatory choroidal neovascularization are often diagnosed and followed with OCT/OCTA scans. However, uveitis specialists can obtain much more information from tomographic scans. This review provides a comprehensive description of typical OCT/OCTA findings characterizing different ocular structures in uveitis, proceeding from the cornea to the choroid. A careful interpretation of OCT/OCTA images can help in the differential diagnosis, the prediction of clinical outcomes, and the follow-up of patients with uveitis

Cap rock efficiency of geothermal systems in fold-and-thrust belts: Evidence from paleo-thermal and structural analyses in Rosario de La Frontera geothermal area (NW Argentina)

Cap rock characterization of geothermal systems is often neglected despite fracturing may reduce its efficiency and favours fluid migration. We investigated the siliciclastic cap rock of Rosario de La Frontera geothermal system (NW Argentina) in order to assess its quality as a function of fracture patterns and related thermal alteration. Paleothermal investigations (XRD on fine-grained fraction of sediments, organic matter optical analysis and fluid inclusions on veins) and 1D thermal modelling allowed us to distinguish the thermal fingerprint associated to sedimentary burial from that related to fluid migration. The geothermal system is hosted in a Neogene N-S anticline dissected by high angle NNW- and ENE-striking faults. Its cap rock can be grouped into two quality categories: • rocks acting as good insulators, deformed by NNW–SSE and E–W shear fractures, NNE-SSW gypsum- and N-S-striking calcite-filled veins that developed during the initial stage of anticline growth. Maximum paleo-temperatures (< 60 °C) were experienced during deposition to folding phases.• rocks acting as bad insulators, deformed by NNW-SSE fault planes and NNW- and WNW-striking sets of fractures associated to late transpressive kinematics. Maximum paleo-temperatures higher than about 115 °C are linked to fluid migration from the reservoir to surface (with a reservoir top at maximum depths of 2.5 km) along fault damage zones.This multi-method approach turned out to be particularly useful to trace the main pathways of hot fluids and can be applied in blind geothermal systems where either subsurface data are scarce or surface thermal anomalies are lacking.Fil: Maffucci, R.. Universita Degli Studi Della Tuscia; Italia. Universita Degli Studi Roma Tre; ItaliaFil: Corrado, Sveva. Universita Degli Studi Roma Tre; ItaliaFil: Aldega, L.. Instituto de Investigaciones Universitarias Roma la Sapienza; ItaliaFil: Bigi, S.. Instituto de Investigaciones Universitarias Roma la Sapienza; ItaliaFil: Chiodi, Agostina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Di Paolo, L.. Eni E&P Division; ItaliaFil: Giordano, G.. Universita Degli Studi Roma Tre; ItaliaFil: Invernizzi, C.. Universita Degli Di Camerino; Itali

The &quot;safe falls, safe schools&quot; multicentre international project: Evaluation and analysis of backwards falling ability in Italian secondary schools

Problem statement: Different studies have reported on the epidemiology related to injuries resulting from falls, which are the most common causes of injury in Italy. The World Health Organization considers falls as the second leading cause of accidental or unintentional deaths worldwide. However, it has been demonstrated that the Safe Fall, Safe Schools Programme (SFSSP) based on 10-min warm-up sessions is able to teach techniques for falling backwards in safe way during physical education (PE) classes. Unfortunately, there are no studies that have analysed extensive warm-up and detraining effects related to the age. Aim: The aim of this study was to assess extensive specific warm-up (20 min) and detraining effects after five weeks on the SFSSP on Italian secondary school students according to age. Methods: Eighty-seven secondary school students took part in this investigation. Students were divided into two groups, equally distributed by age. The trial-control group (TC=39) and the control-trial group (CT=48) performed the same PE lesson for 10 weeks. In the first five weeks, two different 20-min warm-up exercises were performed (TC=SFSSP; CT=conventional warm-up); after five weeks, the warm-ups were inverted (TC=conventional warm-up; CT=SFSSP). The backwards falling ability test carried out among both groups was evaluated in relation to the position of the neck, trunk, knees, hips and hands, before and after five and 10 weeks. Results: McNemar\u2019s test showed significant differences (between pre-and mid-time points, P&lt;0.05) for the neck, trunk, hip and hands, while no significant differences were found in the knee value (P=0.581 in TC). No differences were found between the mid-and post-time points for TC. In CT, no differences were found in-between (pre-and mid-time points, P&gt;0.05) for all variables studied. Significant differences (P&lt;0.05) were found in-between the mid-and post- time points for CT in all variables studied. Analysis of the total scores for SFSSP showed significantly differences in TC and CT (P&lt;0.0001). The Wilcoxon signed-rank test showed no significant differences (total scores: first year=1.68\ub11.05 AU; fifth year=1.47\ub10.86 AU; P=0.34) before the SFSSP intervention, while the SFSSP was able to improve the ability after intervention (total scores: first year=4.47\ub10.84 AU; fifth year=3.91\ub11.40 AU; P&lt;0.01). Conclusions: The SFSSP was able to improve motor ability for both groups and the detraining effect was found to maintain the same ability level compared to that after the SFSSP intervention. Participants started with the same level of backwards falling ability and each group, after the intervention, significantly raised its score, confirming the efficacy of the intervention. Therefore, the SFSSP could be included in the standard national programme without changing the standard training lesson

Entanglement of two blocks of spins in the critical Ising model

We compute the entropy of entanglement of two blocks of L spins at a distance d in the ground state of an Ising chain in an external transverse magnetic field. We numerically study the von Neumann entropy for different values of the transverse field. At the critical point we obtain analytical results for blocks of size L=1 and L=2. In the general case, the critical entropy is shown to be additive when d goes to infinity. Finally, based on simple arguments, we derive an expression for the entropy at the critical point as a function of both L and d. This formula is in excellent agreement with numerical results.Comment: published versio