This study analyses the energy consumption of a social housing built in the 80′s. This typology is widely diffused in the building stock of Rome and of the city’s suburbs and for this its improvement ...represents a dutiful effort for the Italian national scene, where the energy efficiency of public social housing is a major concern. Public funding is significantly reduced compared to the past and the conditions of the buildings are deteriorating over time, resulting in an increase in energy consumption for air conditioning and in indoor comfort conditions very far from the standards. Often it is also very difficult to act on the passive system, with the insertion of a thermal insulation, as well as inside the apartments, with the replacement of terminal units. For this reason a good way is to evaluate the possibility of modifying the thermal energy generation system, preserving as much as possible the distribution and supply system inside the apartments. In general, where the boiler is not obsolescent, the idea is to propose a hybrid generation system with the inclusion of a heat pump (HHP), which could be implemented with renewable energy equipment, properly installed in the building. The results show that a hybrid system can lower the primary energy consumption up to 28%, thus allowing the employment of renewable energies within the social housing building stock.
In this work, we present experimental results of a prompt gamma camera for real-time proton beam range verification. The detection system features a pixelated Cerium doped lutetium based ...scintillation crystal, coupled to Silicon PhotoMultiplier arrays, read out by dedicated electronics. The prompt gamma camera uses a knife-edge slit collimator to produce a 1D projection of the beam path in the target on the scintillation detector. We designed the detector to provide high counting statistics and high photo-detection efficiency for prompt gamma rays of several MeV. The slit design favours the counting statistics and could be advantageous in terms of simplicity, reduced cost and limited footprint. We present the description of the realized gamma camera, as well as the results of the characterization of the camera itself in terms of imaging performance. We also present the results of experiments in which a polymethyl methacrylate phantom was irradiated with proton pencil beams in a proton therapy center. A tungsten slit collimator was used and prompt gamma rays were acquired in the 3-6 MeV energy range. The acquisitions were performed with the beam operated at 100 MeV, 160 MeV and 230 MeV, with beam currents at the nozzle exit of several nA. Measured prompt gamma profiles are consistent with the simulations and we reached a precision (2σ) in shift retrieval of 4 mm with 0.5 × 10(8), 1.4 × 10(8) and 3.4 × 10(8) protons at 100, 160 and 230 MeV, respectively. We conclude that the acquisition of prompt gamma profiles for in vivo range verification of proton beam with the developed gamma camera and a slit collimator is feasible in clinical conditions. The compact design of the camera allows its integration in a proton therapy treatment room and further studies will be undertaken to validate the use of this detection system during treatment of real patients.
Treatments delivered by proton therapy are affected by uncertainties on the range of the beam within the patient, requiring medical physicists to add safety margins on the penetration depth of the ...beam. To reduce these margins and deliver safer treatments, different projects are currently investigating real-time range control by imaging prompt gammas emitted along the proton tracks in the patient. This study reports on the feasibility, development and test of a new concept of prompt gamma camera using a slit collimator to obtain a one-dimensional projection of the beam path on a scintillation detector. This concept was optimized, using the Monte Carlo code MCNPX version 2.5.0, to select high energy photons correlated with the beam range and detect them with both high statistics and sufficient spatial resolution. To validate the Monte Carlo model, spectrometry measurements of secondary particles emitted by a PMMA target during proton irradiation at 160 MeV were realized. An excellent agreement with the simulations was observed when using subtraction methods to isolate the gammas in direct incidence. A first prototype slit camera using the HiCam gamma detector was consequently prepared and tested successfully at 100 and 160 MeV beam energies. Results confirmed the potential of this concept for real-time range monitoring with millimetre accuracy in pencil beam scanning mode for typical clinical conditions. If we neglect electronic dead times and rejection of detected events, the current solution with its collimator at 15 cm from the beam axis can achieve a 1-2 mm standard deviation on range estimation in a homogeneous PMMA target for numbers of protons that correspond to doses in water at the Bragg peak as low as 15 cGy at 100 MeV and 25 cGy at 160 MeV assuming pencil beams with a Gaussian profile of 5 mm sigma at target entrance.
In this study, we present the preliminary imaging results obtained with a gamma module called BeNEdiCTE, specifically designed for boron neutron capture therapy (BNCT). The primary objective of the ...BNCT-SPECT system is to quantitatively assess and pinpoint the 10B contribution to the dose administered to a patient during BNCT treatment by detecting the 478-keV gamma rays emitted from the 10B(n,<inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>)7Li reactions. Starting from a feasibility study of a collimator suitable for a BNCT-SPECT system, we end up presenting the first images obtained by reconstructing vials containing boron powder thanks to the aid of an artificial neural network (ANN). However, the extremely high-intensity neutron flux of <inline-formula> <tex-math notation="LaTeX">10{^{{9}}} </tex-math></inline-formula> n/cm2/s and the presence of mixed radiation fields in the irradiation room pose significant challenges to this task. To overcome these challenges, the implementation of an appropriate collimator becomes essential. Thanks to Monte Carlo simulations, we designed a lead pinhole collimator, with a twofold focus on enhancing spatial resolution (achieving <1 cm) and maximizing geometric efficiency (GE) (attaining <inline-formula> <tex-math notation="LaTeX">\gt 10{^{-}6 } </tex-math></inline-formula>).
This study suggests a methodology for damage diagnosis in structures, which is based on a multivariate statistical procedure and uses the measured time domain structural vibration response. In this ...paper the methodology is developed for the purposes of delamination assessment in free vibrating composite laminate plates. It applies singular spectrum analysis to the measured strains in order to decompose and compress the information contained in these responses into a smaller number of independent variables. The method works on the principle of clusterization between healthy and delaminated plates with different delamination sizes and locations. The developed methodology is then applied and verified on numerically simulated and experimentally obtained results for composite laminate plates. The results demonstrate a good capability for clusterization between different delamination scenarios in composite laminate plates.
Coronavirus disease (COVID-19) usually starts with pulmonary signs and symptoms. However, in some cases, the initial clinical presentations are extrapulmonary. This literature review aimed at ...summarizing and discussing the extrapulmonary onset manifestations of COVID-19. The most frequent initial extrapulmonary manifestations include hypogeusia, hyposmia, non-specific abdominal symptoms, corneal congestion, and deep venous thrombosis. Several rarer extrapulmonary manifestations in locations such as the brain, peripheral nerves, muscles, eyes, ears, myocardium, intestines, skin, or vessels have been additionally reported as onset presentations of COVID-19. In conclusion, it is crucial for clinicians and health care providers to consider extrapulmonary presentations at the onset of COVID-19 to avoid overlooking the infection and contributing to the spread of the disease.
The K¯N system at threshold is a sensitive testing ground for low energy QCD, especially for the explicit chiral symmetry breaking. Therefore, we have measured the K-series X-rays of kaonic hydrogen ...atoms at the DAΦNE electron–positron collider of Laboratori Nazionali di Frascati, and have determined the most precise values of the strong-interaction energy-level shift and width of the 1s atomic state. As X-ray detectors, we used large-area silicon drift detectors having excellent energy and timing resolution, which were developed especially for the SIDDHARTA experiment. The shift and width were determined to be ϵ1s=−283±36(stat)±6(syst) eV and Γ1s=541±89(stat)±22(syst) eV, respectively. The new values will provide vital constraints on the theoretical description of the low-energy K¯N interaction.
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