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The widespread diffusion of renewable energy sources calls for the development of high-capacity energy storage systems as the A-CAES (Adiabatic Compressed Air Energy Storage) systems. In this framework, low temperature (100°C–200°C) A-CAES (LT-ACAES) systems can assume a key role, avoiding some critical issues connected to the operation of high temperature ones.In this paper, two different LT-ACAES configurations are proposed. The two configurations are characterized by the same turbomachines and compressed air storage section, while differ in the TES section and its integration with the turbomachinery. In particular, the first configuration includes two separated cycles: the working fluid (air) cycle and the heat transfer fluid (HTF) cycle. Several heat exchangers connect the two cycles allowing to recover thermal energy from the compressors and to heat the compressed air at the turbine inlet. Two different HTFs were considered: air (case A) and thermal oil (case B). The second configuration is composed of only one cycle, where the operating fluid and the HTF are the same (air) and the TES section is composed of three different packed-bed thermal storage tanks (case C). The tanks directly recover the heat from the compressors and heat the air at each turbine inlet, avoiding the use of heat exchangers.The LT-ACAES systems were modelled and simulated using the ASPEN-Plus and the MATLAB-Simulink environments. The main aim of this study was the detailed analysis of the reciprocal influence between the turbomachinery and the TES system; furthermore, the performance evaluation of each plant was carried out assuming both on-design and off-design operating conditions. Finally, the different configurations were compared through the main performance parameters, such as the round-trip efficiency.A total power output of around 10 MW was set, leading to a TES tank volume ranging between 500 and 700 m3. The second configuration with three TES systems appears to be the most promising in terms of round-trip efficiency since the energy produced during the discharging phase is greater. In particular, the round-trip efficiency of the LT-ACAES ranges between 0.566 (case A) to 0.674 (case C). Although the second configuration assures the highest performance, the effect of operating at very high pressures inside the tanks should be carefully evaluated in terms of overall costs.

The aim of this study is to evaluate the most suitable operating conditions for anaerobic co-digestion processes with high replacement rates (64% on average) of dedicated crops (silage of maize and triticale) with residual biomass, represented by a mixture of whey (scotta), pitted olive pomace, olive mill wastewater, and sheep manure. Experimental trials were first carried out at pilot plant scale and then at industrial plant scale. Univariate and multivariate statistical analysis demonstrates that almost 70% of the dedicated crops, ordinarily used in industrial scale anaerobic digestion plants, can be replaced by a mixture of residual biomass, available on the territory, without a reduction in performance. Compared to the industrial plant, the pilot plant shows much higher values of biogas production rate and specific production rates for both biogas (about 0.64–0.86 Nm3/kgVS vs 0.35 Nm3/kgVS) and methane (about 0.30–0.43 Nm3/kgVS vs 0.20 Nm3/kgVS). With reference to a case-study of the Sardinia island, the use of all available biomass residues in existing and new anaerobic digestion plants can provide a production of more than 160 million Nm3/y of biogas, that corresponds to about 87 millions Nm3/y of biomethane, that is about 20% of the forecasted natural gas demand of the island.

In the last decades the population undergoing non-cardiac surgery has become more numerous and complex. Cardiovascular perioperative complications represent at least one third of the perioperative deaths. Despite the pivotal role of the cardiologist in the perioperative management, current guidelines are often hardly useful in different settings of clinical practice. Local clinical protocols contribute to fill these gaps, to define the role of each specialist in the perioperative context and to achieve the best medical outcome.This single-center retrospective study analyzes the background of 33 463 preoperatory cardiologic visits, the adherence to scientific evidence in our institute and the impact of the implementation of a shared clinical protocol (CP) in terms of reduction of inappropriate requests of cardiological evaluations.Among all the patients, the mean age was 59 ± 18 years, 52.8% were male. Hypertension was the most prevalent disease followed by diabetes, chronic coronary syndrome and atrial fibrillation. The "low-risk surgery" category was the most represented (56.2%) and the vast majority of patients (70.1%) was totally free from predictors of perioperative cardiovascular events. After the introduction of the CP, the number of inappropriate evaluations decreased by 32%, mainly in the low-risk category. However, despite the overall reduction, almost two thirds of the evaluations were still deemed inappropriate according to the CP, mostly (82.9%) in the low-risk category and to a lesser degree (55%) in the moderate/high-risk category.The inappropriate use of the resources resulted in disappointing organizational performance, poor assistance quality and a huge number of inappropriate preoperatory evaluations. The implementation of a CP, developed on the basis of the local needs, is a useful tool to enhance the organizational standards for the cardiological evaluation of patients undergoing non-cardiac surgery. Regular verifications, a widespread knowledge of the guidelines and a more efficient system of management and surveillance may improve the appropriateness of these evaluations.

The application of Organic Rankine cycle (ORC) units in concentrating solar power systems is a very promising solution. However, fluctuations in the available solar energy often force solar-based ORC systems to operate at off-design conditions. An innovative methodology for finding robust design solutions of such ORC systems, based on the minimization of the expected Levelized Cost of Energy (LCOE), is therefore proposed. The expected variations in the ORC heat source and heat sink are considered during the design stage by adopting a multi-scenario approach. The proposed methodology has been tested by referring to a medium-scale ORC unit and by considering different working fluids. As case studies, the direct coupling of the ORC unit with a solar field and the integration of a thermal energy storage system have been investigated. The comparison of the results obtained by using a multi-scenario and a single-scenario approach highlights a reduction of the actual LCOE. The ORC configuration obtained by adopting a multi-scenario approach is characterized by lower performance under design conditions, but it is less sensitive to variations in the main inputs during off-design operating periods. This fact is particularly noteworthy for the case with the direct coupling of the solar field.

Post-myocardial infarction ventricular septal defect (VSD) is a life-threatening complication following ST Elevation myocardial infarction (STEMI). Current guidelines recommend the urgent VSD closure for his significant mortality. Despite VSD has been generally treated by surgical repair, often surgeons refrain from early surgery due to extremely poor results. We report the case of a 76-year-old female admitted to our hospital for a subacute myocardial infarction complicated by acute heart failure with VSD and apical thrombosis. The patient has undergone an urgent surgical repair of VSD with a bovine pericardium patch and concomitant double saphenous vein graft for the left anterior descending and the first diagonal branch. After two days a rescue percutaneous closure of a new shunt formation due to an early surgical patch dehiscence was necessary. Considering the particular morphology of the new shunt following the unnatural anatomy of the septum generating by dehiscence, we have planned to close the defect using a device undedicated for ventricular rupture, as 30/30 mm Amplatzer ASD-MF occluder, obtaining an optimal final result. At one-year follow up the patient was alive, with a NYHA class II-III without significant residual shunt.

This study aims to investigate the performance and economic benefits arising from the integration of concentrating solar power (CSP) plants with anaerobic digestion processes. To demonstrate the capabilities of hybrid CSP-biogas plants, the CSP section of the Ottana solar facility (Italy) is considered as a case study. A simulation model for the performance analysis of the hybrid system is developed, and the effects of variation in the volume of the anaerobic digester and the biogas storage capacity on the main performance indexes are evaluated. Furthermore, two different operating strategies for energy storage management are compared and the possible requirements for energy curtailment are analysed. Finally, a preliminary economic analysis is carried out. The results demonstrate the benefits and improvements in plant capacity factor and efficiency arising from proper sizing of the biogas section. Conversely, oversizing of the biogas section results in significant curtailments in biogas and/or solar field energy production, due to the limited storage capacity. Consequently, the optimal configuration, even from an economic point of view, is achieved by a biogas section of a size that is able to supply part (in the range of 10%–65%) of the nominal thermal power input required by the power block.

The Ottana solar facility aims to demonstrate the capabilities of concentrating solar technologies to provide dispatchable power and ancillary services at distribution level. The facility includes a 630 kW Concentrating Solar Power (CSP) plant with thermal storage coupled with a 400 kW Concentrating Photovoltaic (CPV) plant with electrochemical storage. The CSP + CPV plant aims to study the ability of the integrated concentrating solar systems to deliver scheduled power profiles for the following day on the basis of weather forecasting data. The CSP section is based on linear Fresnel collectors using thermal oil as heat transfer fluid and a two-tank direct Thermal Energy Storage (TES) system with a storage capacity of about 15 MWht. The power generation is carried out by a 630 kW Turboden 6HR Special ORC unit. This paper focuses on a description of the CSP plant section and on the analysis of its expected performance. In particular, the control strategy developed for determining the daily power profiles starting from the weather forecasting data is presented. Moreover, the first operating results and the expected performance of the CSP plant are reported and discussed.

Journal of synchrotron radiation 27(2), 250 - 253 (2020). doi:10.1107/S1600577520001125, Published by Wiley-Blackwell, [S.l.]

Herein, we report an eco-friendly, electrosynthetic approach for the intramolecular oxyselenylation of allyl-naphthol/phenol derivatives. This reaction proceeds with 0.2 equiv. of nBu4NClO4 as an electrolyte and Pt working electrodes in an undivided cell, resulting in the selenyl-dihydrofurans in good to excellent yields. Furthermore, several of the synthesized products presented a high percentage of acetylcholinesterase (AChE) inhibition, highlighting their potential anti-Alzheimer activity.

Four-dimensional (4D) flow sequences are an innovative type of MR sequences based upon phase contrast (PC) sequences which are a type of application of Angio-MRI together with the Time of Flight (TOF) sequences and Contrast-Enhanced Magnetic Resonance Acquisition (CE-MRA). They share the basic principles of PC, but unlike PC sequences, 4D flow has velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage. They guarantee the analysis of flow with multiplanarity on a post-processing level, which is a unique feature among MR sequences. Furthermore, this technique provides a completely new level to the in vivo flow analysis as it allows measurements in never studied districts such as intracranial applications or some parts of the heart never studied with echo-color-doppler, which is its sonographic equivalent. Furthermore, this technique provides a completely new level to the in vivo flow analysis as it allows accurate measurement of the flows in different districts (e.g., intracranial, cardiac) that are usually studied with echo-color-doppler, which is its sonographic equivalent. Of note, the technique has proved to be affected by less inter and intra-observer variability in several application. 4D-flow basic principles, advantages, limitations, common pitfalls and artefacts are described. This review will outline the basis of the formation of PC image, the construction of a 4D-flow and the huge impact the technique is having on the cardiovascular non-invasive examination. It will be then studied how this technique has had a huge impact on cardiovascular examinations especially on a central heart level.

This paper aims to evaluate the optimal configuration of an Adiabatic Compressed Air Energy Storage (ACAES) system designed to achieve the best matching between power production from non-programmable Renewable Energy Sources (RES) power plants and power demand from final users. The electrical energy demand of a small town, with a maximum power load of about 10 MW, has been considered as case study. The electrical energy can be supplied by both a photovoltaic (PV) power plant and the grid. For the ACAES system, different sizes for compressor, turbine, thermal energy storage (TES) system and air storage reservoir have been evaluated by varying the air mass flow rate of turbomachines and the charging and discharging duration times, to enhance the share of the PV energy supplied to the end user. The best performance is achieved with a PV power plant rated at about 35 MW and an ACAES section characterized by a compressor/turbine rated power of about 25-35% of the maximum power load of the end user, with a charging time of about 10 hours and a discharging time of about 20 hours. The average round-trip efficiency of the ACAES system is around 70%. On the overall, the integrated PV-ACAES system allows to cover 66% of the yearly electrical energy demand.

This paper aims to evaluate the environmental impact along the overall life cycle of the various components of a Hydrogen Valley with multiple end-users fed by green hydrogen. As case study, a hydrogen valley including a MW-scale electrolyser powered by different percentages of energy supplied by a wind farm and/or a photovoltaic plant, and an H2 storage section is considered. The H2 produced is used to feed a fleet of fuel cell electric vehicles and a stationary fuel cell, while the residue H2 is injected in a natural gas pipeline considering a maximum safety limit of 5%vol. When the safety limit is reached, the H2 overproduction can be used to produce biomethane through a biological hydrogen methanation process. With the aim of analysing the actual contribution of these hydrogen-based ecosystems towards more sustainable energy systems, a Life Cycle Analysis of the hydrogen valley is carried out. The results show that the final use of hydrogen for fuel cell electric vehicles produces the most valuable environmental benefits. Moreover, Hydrogen Valley solutions integrated with photovoltaic plants allows to maximize the use of H2 in fuel cell electric vehicles and therefore are the most valuable choice from an environmental point of view.

Organic Rankine cycle (ORC) powered by solar energy is a viable and effective option for a high efficiency conversion of solar thermal energy into electricity at a distributed scale but recurring fluctuations of the thermal energy often force solar-based ORC systems to operate at part-load conditions. With the aim of including the effects of the expected variations of the heat source and heat sink characteristics, even during the design phase, a novel optimization approach for the preliminary design of ORC systems integrated with concentrating solar collectors is presented and analysed. In particular, the minimization of the expected levelized cost of energy (LCOE) of the ORC unit is chosen as an objective function, while the generation of various scenarios is proposed to face the expected fluctuations on the heat source mass flow rate and temperature and cooling inlet temperature. In this way, the expected off-design performances are involved during the design step, giving robustness to the optimal design solution. The proposed methodology is tested by referring to the solar ORC system configuration of the Ottana solar facility. Firstly, the effect of a robust optimization on the preliminary ORC design is investigated by considering an increased number of scenarios for each of the three most significant ORC input variables (heat source mass flow rate and temperature and ambient temperature). Subsequently, the proposed methodology was applied to an ORC design case by considering a concurrent variation of the three variables and three different working fluids. The results of this study demonstrate that a multi-scenario approach drives towards an ORC configuration with lower performance under design conditions, but less sensitive to the variation of the main inputs. Less expensive solutions are therefore achieved by the proposed methodology, but the annual energy production obtained is comparable with those achieved by adopting a single scenario approach, with a consequent reduction of the LCOE.

Cancer and chemotherapy are known to be risk factors for developing coagulative disorders, venous thrombosis, adverse cardiovascular events, and cardiotoxicity. Combined modality gemcitabine–cisplatin chemotherapy is often administered to treat a few solid tumors. We report the unusual case of a man suffering from urothelial cancer and admitted for chemotherapy, who developed an ischemic stroke after the last chemotherapeutical cycle. During his hospital stay, at echocardiographic examination, left ventricular transient hypokinesia and two intraventricular thrombi were detected, without evidence of acute coronary syndrome. Multimodality imaging approach (i.e., transthoracic echo, transoesophageal echo, computed tomography, and cardiac magnetic resonance imaging) played a pivotal role for a clear diagnosis and prompt decision-making. This is the first report of an intraventricular-related arterial thromboembolic event in a patient treated with the combination gemcitabine–cisplatin.

A Power-to-Methane system based on a Biological Hydrogen Methanation (BHM) process using the CO2 produced by a biogas upgrading process and the H2 produced by an alkaline electrolyser was analysed in this work. The electrolyser can be fed by the electrical energy produced by a dedicated PV plant or supplied by the electrical grid. The analysis of the energy production from the PV plant and the consumption of the electrolyser was carried out on an hourly basis considering different sizes for the PV plant and four different scenarios for the operating time of the electrolyser. Also, a preliminary economic analysis was carried out to estimate the levelized cost of biomethane (LCOBM) and the costs of biomethane transport with a dedicate pipeline and in form of LNG by trucks. Finally, the paper investigated the availability of biomass and biogas in Sardinia that can be converted into biomethane, and the contribution of BHM plants to supply the forecast demand of CH4. The availability of biogas in Sardinia, together with the production of biomethane through BHM systems, can supply up to 44% of the forecast demand of CH4.

Background Anthracycline (ANT) therapy has dramatically improved clinical outcomes for patients with breast cancer, but it causes cardiotoxicity (CTX) in a dose-dependent manner. Current cardiac biomarkers (troponin, brain natriuretic peptide) and 2D echocardiography only detect CTX in advanced and often irreversible stages. Metabolomic analysis may allow early diagnosis of CTX, and prompt initiation of cardio protective therapies. Purpose To diagnose early CTX via speckle tracking echocardiography (STE), and to characterize the metabolomic fingerprint of patients affected by ANT-mediated CTX. Methods In 2019, patients with breast cancer and normal baseline ejection fraction (EF) were enrolled and longitudinally monitored through clinical assessment, blood sample collection and echocardiography, before initiation of ANT therapy and at 180, 270 and 360 mg/m2 of ANT. CTX, defined as >15% reduction in Global Longitudinal Strain (GLS), was monitored at each ANT dose increment. Unsupervised Principal Component Analysis, supervised Partial Least Square and Partial Least-Square Discriminant Analyses were used to compare the metabolomic profiles of patients who did and did not develop CTX during the study period. Results In the study sample (n=33), no patient developed clinical heart failure, but 8 patients (25%) developed CTX by GLS criteria. Patients with CTX had a significant decrease in GLS compared to patients without CTX at 270 mg/m2 (GLS 20.5 vs 17.9, p=0.01) and 360 mg/m2 ANT (GLS 21.6 vs 17.7, p Conclusions For the first time in a human population of breast cancer patients, we show that early ANT-induced CTX (diagnosed via asymptomatic GLS reduction) is associated with a unique metabolomic profile, which affects molecular pathways of energy production. Notably, CTX damage upregulates similar metabolites to those previously identified in clinical heart failure and in mouse CTX models. Our results suggest that a metabolomic fingerprint can be leveraged to create prediction models to identify patients at higher risk of developing cardiovascular complications from ANT therapy. This, in turn, will allow to personalize both chemotherapy and cardioprotective treatments. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): University of Cagliari

A cantilevered liquid-nitrogen-cooled silicon mirror is described that will achieve diffraction-limited performance even under extreme power density. This mirror will serve as a robust first optic for the high-brightness undulator beamlines at the upgraded Advanced Light Source., This paper presents a novel cantilevered liquid-nitro­gen-cooled silicon mirror design for the first optic in a new soft X-ray beamline that is being developed as part of the Advanced Light Source Upgrade (ALS-U) (Lawrence Berkeley National Laboratory, USA). The beamline is optimized for photon energies between 400 and 1400 eV with full polarization control. Calculations indicate that, without correction, this design will achieve a Strehl ratio greater than 0.85 for the entire energy and polarization ranges of the beamline. With a correction achieved by moving the focus 7.5 mm upstream, the minimum Strehl ratio is 0.99. This design is currently the baseline plan for all new ALS-U insertion device beamlines.

In the field of beam physics, two frontier topics have taken center stage due to their potential to enable new approaches to discovery in a wide swath of science. These areas are: advanced, high gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest in the marriage of these two fields, with the goal of producing a very compact XFEL. In this context, recent advances in high gradient radio-frequency cryogenic copper structure research have opened the door to the use of surface electric fields between 250 and 500 MV/m. Such an approach is foreseen to enable a new generation of photoinjectors with six-dimensional beam brightness beyond the current state-of-the-art by well over an order of magnitude. This advance is an essential ingredient enabling an ultra-compact XFEL (UC-XFEL). In addition, one may accelerate these bright beams to GeV scale in less than 10 meters. Such an injector, when combined with inverse free electron laser-based bunching techniques can produce multi-kA beams with unprecedented beam quality, quantified by ~50 nm-rad normalized emittances. These beams, when injected into innovative, short-period (1-10 mm) undulators uniquely enable UC-XFELs having footprints consistent with university-scale laboratories. We describe the architecture and predicted performance of this novel light source, which promises photon production per pulse of a few percent of existing XFEL sources. We review implementation issues including collective beam effects, compact x-ray optics systems, and other relevant technical challenges. To illustrate the potential of such a light source to fundamentally change the current paradigm of XFELs with their limited access, we examine possible applications in biology, chemistry, materials, atomic physics, industry, and medicine which may profit from this new model of performing XFEL science., 80 pages, 24 figures

A realistic wave optics simulation method has been developed to study how wavefront distortions originating from heat load deformations can be corrected using adaptive X-ray optics. Several planned soft X-ray and tender X-ray insertion-device beamlines in the Advanced Light Source upgrade rely on a common design principle. A flat, first mirror intercepts the white beam; vertical focusing is provided by a variable-line-space monochromator; and horizontal focusing comes from a single, pre-figured, adaptive mirror. A variety of scenarios to cope with thermal distortion in the first mirror are studied by finite-element analysis. The degradation of the intensity distribution at the focal plane is analyzed and the adaptive optics that correct it is modeled. The range of correctable wavefront errors across the operating range of the beamlines is reported in terms of mirror curvature and spatial frequencies. The software developed is a one-dimensional wavefront propagation package made available in the OASYS suite, an adaptable, customizable and efficient beamline modeling platform.

This study aims to investigate comparative techno-economic benefits of biomass combustion and anaerobic digestion systems as retrofit to concentrated solar power (CSP) plants. In this regard, technical parameters of an existing CSP plant currently in operation in Ottana (Italy) have been adopted for analyses. The biomass combustion technology involves direct burning of solid biomass in a furnace, while the anaerobic digestion technology entails biogas production from fruit and vegetable wastes. For the two technologies, the biomass retrofit system was proposed to constantly supply 45% of the nominal thermal power demand of the power block. Results demonstrated the energetic and economic benefits arising from the hybridization of existing CSP plants, both in terms of enhancement of the plant capacity factor and reduction of the cost of energy. Preliminary economic analysis highlighted the direct combustion of solid biomass as a more cost-effective option, while anaerobic digestion biogas plant suffers from substantial installation costs.

The focusing mirrors for the new LCLS soft x-ray (SXR) experimental hutches are tangential pre-shaped mirrors mounted in a Kirkpatrick Baez configuration. The mirrors are prefigured with an elliptical profile, coinciding with the longest working focal distance. The mirrors are equipped with benders to enable focusing of the beam at different experimental stations and to work out of focus with an uniform beam. To add complexity to the system, the mirrors are also water-cooled and need to fit in a very tight space, due to real estate limitation. For ensuring that the mirror profile is maintained at its sub-nm quality after the assembly of the mirror into its cooling and mechanical system, these mirrors need to undergo an extensive optics metrology study. The vertical and horizontal KB mirrors are first checked for twist error due to the mounting of the mirror substrate to its mechanics. This is measured with grazing incidence Fizeau interferometry. Then the mounted mirror needs to be shimmed to correct for any errors that may be caused by gluing of the mirror. This step requires a sequence of shimming and metrology measurement and must be repeated until the mirror shape is satisfactory. In addition, the mirror bender response function must be well-characterized and documented for the commissioning as well as operation of these mirrors in the experimental hutches. The response function can be attained by measuring the mirror profile using the instruments available in the LCLS Optics Metrology Laboratory and the stitching techniques developed at LCLS. The mirrors are scheduled to be installed in the new SXR beamline in spring 2020. Metrology data and initial commissioning results proving the performance of these wavefront preserving optics will be presented in this report.

In this paper we provide an update on the development of a novel cantilevered-liquid-nitrogen-cooled-silicon mirror for a new insertion device beamline included in the Advanced Light Source Upgrade (ALS-U). The goals of this mirror development are to achieve diffraction limited performance, demonstrate reliability, minimize coolant flow induced vibration, and demonstrate carbon contamination prevention and cleaning techniques. In this paper we summarize the design requirements, the design of the mirror system, and prototype fabrication.

We describe the implementation of realistic, adaptive wavefront correction in high-brightness beamline simulations to study the correction of thermal deformation. Several planned soft x-ray and tender x-ray insertion-device beamlines in the Advanced Light Source upgrade, where wavefront preservation is paramount, rely on a common design principle.After studying the performance of a 20-channel adaptive x-ray mirror prototype, at-wavelength and with visible-light, we implemented mirror shape-control algorithms in software that are designed to restore and optimize the focused beam intensity (i.e. Strehl ratio), considering the incident wavefront’s phase and amplitude. We implemented the modeling in OASYS which is an adaptable, customizable beamline modeling platform well suited to study this issue.

This case shows how interaction between imaging experts and interventionists allowed us to overcome the challenge of plug-prosthesis interaction in a complex procedure.

This article describes the development and testing of a novel, water-cooled, active optic mirror system (called “REAL: Resistive Element Adjustable Length”) that combines cooling with applied auxiliary heating, tailored to the spatial distribution of the thermal load generated by the incident beam. This technique is theoretically capable of sub-nanometer surface figure error control even at high power density. Tests conducted in an optical metrology laboratory and at synchrotron X-ray beamlines showed the ability to maintain the mirror profile to the level needed for the next generation storage rings and FEL mirrors.

Oscillators are at the heart of optical lasers, providing stable, transform-limited pulses. Until now, laser oscillators have been available only in the infrared to visible and near-ultraviolet (UV) spectral region. In this paper, we present a study of an oscillator operating in the 5- to 12-keV photon-energy range. We show that, using the [Formula: see text] line of transition metal compounds as the gain medium, an X-ray free-electron laser as a periodic pump, and a Bragg crystal optical cavity, it is possible to build X-ray oscillators producing intense, fully coherent, transform-limited pulses. As an example, we consider the case of a copper nitrate gain medium generating [Formula: see text] 5 × [Formula: see text] photons per pulse with 37-fs pulse length and 48-meV spectral resolution at 8-keV photon energy. Our theoretical study and simulation of this system show that, because of the very large gain per pass, the oscillator saturates and reaches full coherence in four to six optical-cavity transits. We discuss the feasibility and design of the X-ray optical cavity and other parts of the oscillator needed for its realization, opening the way to extend X-ray–based research beyond current capabilities.

With the aim of increasing the self-consumption rate of grid-connected Photovoltaic (PV) home systems, two main options can be implemented: the inclusion of an energy storage system, in particular a battery bank, and the adoption of a Demand Side Management (DSM) strategy. However, both the reshaping of the load consumption curve with the displacement of deferrable loads and the optimal management of the battery bank require estimation of the daily PV generation profile. The assessment of the on-site energy production can be carried out based on weather forecast data. However, the latter are characterized by uncertainty, which may affect the achievable self-consumption rate. This work investigates the influence of weather forecast errors on the performance of home PV systems equipped with a battery bank and characterized by a certain share of deferrable loads. Two different weather forecast services are considered, referring to the annual meteorological conditions occurring in Rome, and energy consumption data for 150 different households are analysed. The self-consumption rate is maximized by solving a suitable optimization problem, while different combinations of relative battery capacity, PV-to-load ratio and share of deferrable loads are considered. Two different approaches—deterministic and stochastic—are adopted and compared with an ideal approach where the PV generation profile is perfectly forecasted. The results show that the adoption of the deterministic approach leads to a reduction in the achievable self-consumption rate in the range of 0.5–4.5% compared to the ideal approach. The adoption of a stochastic approach further reduces the deviations from the ideal case, especially in the case of consumption profiles with a high share of deferrable loads. Finally, a preliminary economic analysis proves that the use of a battery bank is not yet a cost-effective solution and a price reduction of the current battery prices is therefore required.

This paper aims to evaluate the influence of solar field recirculation on the performance of medium-size Concentrating Solar Power (CSP) systems. Different strategies regarding recirculation paths are proposed and then compared. In particular, cases for total or partial recirculation of the solar field mass flow (those passing through, as well as those bypassing the cold tank) are compared with a strategy of no recirculation during the operating phases that occur throughout the day. The comparative analysis has been carried out by considering three days with different weather conditions, with particular reference to the CSP plant of the Ottana Solar Facility (currently under construction in the industrial district of Ottana, Sardinia, Italy). The results of this study show that partial recirculation of the solar field does not allow performance improvement of the CSP plant. Moreover, bypassing the cold tank in the recirculation path avoids a strong deterioration in performance. Differences between recirculation strategies become subtler for clear-sky days and, therefore, the present results can be very useful for improving the CSP performance, especially during mostly cloudy days.