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This paper analyzes the optimal sizing of a particular solution for renewable energy residential building integration. The solution combines a photovoltaic (PV) plant with a heat pump (HP). The idea is to develop a system that permits the maximum level of self-consumption of renewable energy generated by using a small-scale solar array installed on the same building. The problem is analyzed using data obtained from an experimental system installed in a building in Pisa, Italy. The residential house was equipped with a PV plant (about 3.7 kW of peak power), assisting a HP of similar electrical power (3.8 kW). The system was monitored for eight years of continuous operation. With reference to the data acquired from the long-term experimental analysis and considering a more general perspective, we discuss criteria and guidelines for the design of such a system. We focus on the possibility of exporting energy to the electrical grid, from the perspective of obtaining self-consumption schemes. Considering that one of the problems with small-scale PV plants is represented by the bidirectional energy flows from and to the grid, possible alternative solutions for the design are outlined, with both a size reduction in the plant and utilization of a storage system considered. Different design objectives are considered in the analysis. [ABSTRACT FROM AUTHOR]

Energy efficiency, indoor environmental quality, and comfort in public buildings has received increasing attention in recent years as it can contribute to maintaining safety conditions and to the reduction of conventional fuels consumption, energy costs for building owners, and greenhouse gas emissions. People are an integral part of any building energetic ecosystem as, according to some estimates, they spend a great part of their life in indoor spaces. On one side, occupants are responsible for the energy consumption of the building and for this reason the "psychology of energy saving" has received attention since the 70s up to recent results. On the other hand, strategies for energy efficiency should not jeopardize occupants' health and quality of life. While general awareness of the value of environmental variables has increased in the last few years, this interest has recently been further exacerbated by the spreading of the well-known COVID-19 pandemic. In fact, as most countries have started planning post-lock-down activities, there is a growing concern regarding how social distancing measures can be enforced in shared buildings and strict indoor air quality control can prevent airborne virus transmission in crowded spaces. The paper discusses the perspectives of increasing the level of social interaction of building users through the systematic use of Information and Communication Technologies (ICT), and in particular, some specific platforms. The ICT system, taking information from the occupants in a concerted way, can be an important instrument to collect data, coming both from physical sensors and from people to develop a multi-objective control strategy for the Heating, Ventilation, and Air Cooling (HVAC) systems in order to obtain energy savings whilst balancing user comfort and healthy conditions. [ABSTRACT FROM AUTHOR]

Estimating and optimizing the dynamic performance of a heat pump system coupled to a building is a paramount yet complex task, especially under intermittent conditions. This paper presents the "hardware-in-the-loop" experimental campaign of an air-source heat pump serving a typical dwelling in Pisa (Italy). The experimental apparatus uses real pieces of equipment, together with a thermal load emulator controlled by a full energy dynamic simulation of the considered building. Real weather data are continuously collected and used to run the simulation. The experimental campaign was performed from November 2019 to February 2020, measuring the system performances under real climate and load dynamics. With a water set point equal to 40 °C, the average heat pump coefficient of performance was about 3, while the overall building-plant performance was around 2. The deviation between the two performance indexes can be ascribed to the continuous on-off signals given by the zone thermostat due to the oversized capacity of the heat emission system. The overall performance raised to 2.5 thanks to a smoother operation obtained with reduced supply temperature (35 °C) and fan coil speed. The paper demonstrates the relevance of a dynamic analysis of the building-HVAC system and the potential of the "hardware-in-the-loop" approach in assessing actual part-load heat pump performances with respect to the standard stationary methodology. [ABSTRACT FROM AUTHOR]

Air ventilation rate plays a relevant role in maintaining adequate indoor air quality (IAQ) conditions in public buildings. In general, high ventilation rates ensure good indoor air quality but entail relevant energy consumption. Considering the necessity of balancing IAQ and energy consumption, a correlation between the number of occupants obtained from analysis of CO2 concentration variation is presented as a general element for controlling the operation of heating ventilation and air cooling (HVAC) systems. The specific CO2 exhalation rate is estimated using experimental data in some real conditions in university classrooms. A method for the definition of optimal values of air exchange rate is defined, highlighting that the obtained values are much lower than those defined in current technical standards with possibilities of relevant reduction of the total energy consumption. [ABSTRACT FROM AUTHOR]

In this paper, the production of low to medium temperature water for industrial process heat using solar energy is considered. In particular, the paper outlines the perspective of an optimum design method that takes into account all of the typical variables of the problem (solar irradiation, system architecture, design constraints, load type and distribution, and design and optimization criteria) and also considers the use of the fossil fuel backup system. The key element of the methodology is the definition of a synthetic combined energetic and economic utility function. This considers the attribution of an economic penalty to irreversibility in connection with the use of a fossil fuel backup. This function incorporates the share of the solar system production (solar fraction) as an optimum design variable. This paper shows how, using the proposed criteria, the optimal value of the solar fraction, defined as the share of operation of the solar system with respect to the whole energy demand, can be increased. Current practice considers values in the range between 40 and 60%. However, levels up to 80% can also be obtained with the proposed methodology. Thus, penalizing the use of fossil fuels does not exclude a priori their contribution. [ABSTRACT FROM AUTHOR]

The performance of ground heat exchanger systems depends on the knowledge of the thermal parameters of the ground, such as thermal conductivity, capacity, and diffusivity. The knowledge of these parameters often requires quite accurate experimental analysis, known as a thermal response test (TRT). In this paper, after a general analysis of the various available types of TRT and a study of the theoretical basics of the method, we explore the perspective of the definition of a simplified routine method of analysis based on the combination of a particular version of TRT and the routine geotechnical tests for the characterization of soil stratigraphy and the ground characteristics. Geotechnical analyses are indeed mandatory before the construction of new buildings, even if limited to 30 m below the ground level or foundation base when piles are needed. The idea of developing TRT in connection with geotechnical test activity has the objective of promoting the widespread use of in situ experimental analysis and reducing TRT costs and time. The considerations presented in the present paper lead to reconsidering a particular variety of the TRT, in particular, the versions known as thermal response test while drilling (TRTWD) and TRT using heating cables (HC-TRT). [ABSTRACT FROM AUTHOR]

The paper analyzes the problem of defining the potential of geothermal reservoirs and the definition of a sustainable size of a geothermal power plant in the preliminary design phase. While defining the size of a geothermal plant, the objective is to find a compromise between renewability, technical sustainability, and economic return-related issues. In the first part of the paper the simplified lumped parameter approach based on the First-Order methods and their further evolutions and limitations is proposed. Experimental data available for some geothermal reservoirs are used for critical analysis of the simplified approaches for estimating the renewability and sustainability of the production of geothermal plants. In the second part the authors analyze methods based on theoretical heat transfer analysis supported by experimental data acquired from the geothermal field (thermal properties of the rock, porosity of the reservoir, and natural heat flux) and finally consider the numerical simulation as a method to connect the two approaches discussed before. The sustainability of geothermal power production can be estimated taking into account the energy stored in the reservoir and the thermal and fluid dynamic analysis of the reservoir. From this perspective, the numerical simulation of the reservoir can be considered as an effective method for the estimation of a sustainable mass flow rate extraction. Some specific cases are analyzed and discussed. [ABSTRACT FROM AUTHOR]

The low bioavailability of nutrients, especially nitrogen (N) and phosphorus (P), is one of the most limiting factors for crop production. In this study, under N- and P-free nutrient solution (-N-P), nodulating white lupin plants developed some nodules and analogous cluster root structures characterized by different morphological, physiological, and molecular responses than those observed upon single nutrient deficiency (strong acidification of external media, a better nutritional status than -N+P and +N-P plants). The multi-elemental analysis highlighted that the concentrations of nutrients in white lupin plants were mainly affected by P availability. Gene-expression analyses provided evidence of interconnections between N and P nutritional pathways that are active to promote N and P balance in plants. The root exudome was mainly characterized by N availability in nutrient solution, and, in particular, the absence of N and P in the nutrient solution triggered a high release of phenolic compounds, nucleosides monophosphate and saponines by roots. These morphological, physiological, and molecular responses result from a close interplay between N and P nutritional pathways. They contribute to the good development of nodulating white lupin plants when grown on N- and P-free media. This study provides evidence that limited N and P availability in the nutrient solution can promote white lupin-Bradyrhizobium symbiosis, which is favourable for the sustainability of legume production. [ABSTRACT FROM AUTHOR]

Abstract The 73rd Conference of the Italian Thermal Machines Engineering Association (ATI) was held in Pisa (Italy) on September 12-14, 2018. The conference was organized by ATI and the University of Pisa. The main topic of this conference edition was: "Innovation and research for a sustainable energy future" In the last 10 years, the share of renewable sources in the energy mix of several countries has increased at a steady pace. This led to a revolution in the way energy conversion is conceived and distributed in comparison to a fossil based system. Nowadays, thinking about a 100% renewable energy system is no more just a dream. Nevertheless, the transition to this future implies several critical decisions from the technical and economic point of view. The 73rd ATI conference was the opportunity to discuss these topics, present new frontiers of the energy engineering research and promote the cooperation between researchers. The topics of the conference were: Heat Transfer and Fluid Dynamics, Energetics of Buildings, Air Conditioning and Refrigeration, Environmental Aspects of Energy Conversion, Renewable Energy, Advanced Energy Conversion and Storage Systems, Innovative Propulsion Systems and Internal Combustion Engines, Turbomachinery, Combustion and Fuels, Fluid Power. This issue of Energy Procedia includes all the papers presented at the conference, 143 in oral form and 20 in the poster session reserved to PhD students. The conference also included a plenary session and two panel sessions with outstanding keynote speakers from both academy and industry. The Guest Editors of the 73rd Conference of the Italian Thermal Machines Engineering Association [ABSTRACT FROM AUTHOR]

A correction to the article "Perspectives for the long-term penetration of new renewables in complex energy systems: the Italian scenario" by Alessandro Franco and Pasquale Salza is presented.

Italy has experienced a revolution in the electricity production mix in the years 2008-2015, when a large scale deployment of intermittent renewables caused a high volatility of electricity prices, stopped the investments in both fossil and renewable power plants and caused a high degree of uncertainty in matching electricity demand and supply. The current legislation gives renewable energy the priority of dispatchment, producing a significant decrease of the operational hours of all kinds of power plants, which caused economic problems to utilities, that had started investments in new high efficiency combined cycles before 2008, and reduced the overall efficiency of fossil fired power generation. In order to restore the opportunities for further investments in renewable energy systems, it is very important to develop long term policies and interventions to improve the capacity to balance the electricity demand and supply. [ABSTRACT FROM AUTHOR]

This paper deals with the experimental analysis and numerical simulation of a two-phase closed thermosyphon (TPCT) in the aim to predict its transient performances. A concern in the design and operation of the TPCT is evaluating working fluid loading charge to maximize performance while avoiding dryout in the evaporator section and geyser boiling phenomena. The model includes the heat transfer through the wall, the vapor core, the liquid pool and the falling condensate film. The complete two-dimensional conservation equations for mass, momentum, and energy are solved using a finite volume scheme for the vapor flow and the pipe wall. The liquid film is modeled by using one-dimensional quasi-steady Nusselt type solution. An experimental facility has been also designed and operated to determine the operating condition and measure the maximum heat transfer rate and the overall thermal resistance of the TPCT. The total length and the diameter of pipe are 500 mm and 35 mm, respectively. The experiments have been performed in the heat transfer range of 30–700 W and filling ratios of 16, 35 and 135%. The numerical predictions for the maximum heat transport rate due to the transient local dryout are shown to be in close agreement with the experimental results under normal operation. However, for obtained liquid film dryout a discrepancy is observed. The geyser boiling is also evaluated under certain operating condition. [ABSTRACT FROM AUTHOR]

• Occurrence of a strong cross-interaction between Fe and P acquisition mechanisms. • white lupin roots upregulated Fe-responsive genes ascribable to Strategy-I response. • The Strategy-I mechanism was upregulated also in P-deficient clusters roots. • Viceversa , some P-responsive genes were upregulated also in Fe deficient roots. • P and Fe deficiency upregulated glycolysis and phenylpropanoid pathway, respectively. In agricultural soil, the bioavailability of iron (Fe) and phosphorus (P) is often below the plant's requirement causing nutritional deficiency in crops. Under P-limiting conditions, white lupin (Lupinus albus L.) activates mechanisms that promote P solubility in the soil through morphological, physiological and molecular adaptations. Similar changes occur also in Fe-deficient white lupin roots; however, no information is available on the molecular bases of the response. In the present work, responses to Fe and P deficiency and their reciprocal interactions were studied. Transcriptomic analyses indicated that white lupin roots upregulated Fe-responsive genes ascribable to Strategy-I response, this behaviour was mainly evident in cluster roots. The upregulation of some components of Fe-acquisition mechanism occurred also in P-deficient cluster roots. Concerning P acquisition, some P-responsive genes (as phosphate transporters and transcription factors) were upregulated by P deficiency as well by Fe deficiency. These data indicate a strong cross-connection between the responses activated under Fe or P deficiency in white lupin. The activation of Fe- and P-acquisition mechanisms might play a crucial role to enhance the plant's capability to mobilize both nutrients in the rhizosphere, especially P from its associated metal cations. [ABSTRACT FROM AUTHOR]

Two-phase closed thermosyphons (TPCTs) are excellent thermal transfer devices that their integration into heat exchangers has been shown a strong potential for energy savings. The scope of this study is an experimental evaluation of the evaporation and condensation heat transfer of a TPCT for uniformly heated evaporator surface. Water as the working fluid is charged in a TPCT with a length of 500 mm and an inner diameter of 33 mm at different filling ratios (8–100%). The Thermosyphon heat transfer performances are compared with some predictive correlations of suppress the pool boiling insert uniquely and suppress the pool boiling combined with film evaporation for the evaporator section at different filling ratios. The experimentally obtained condensation heat transfer is also evaluated by available filmwise condensation model. Results show an agreement with the most of the selected correlations with tolerance ±30% and the appropriate set of correlations are introduced giving an accuracy within ±10%. [ABSTRACT FROM AUTHOR]

The perspectives of utilization of a screen mesh heat pipe (HP) for low to medium operating temperature applications are studied in this study. A two-dimensional mathematical model for heat and mass transfer of HPs is presented to define its performances under steady state operations. The model couples heat conduction in the wall with both liquid flow in the wick and vapor flow in the core. Experimental analysis is developed to evaluate the influence of operating parameters (the orientation and the cooling temperature) as well as the evaporator section length on the performance of the HP. Furthermore, a modeling approach to optimize the HP performance from a thermal point of view is presented. Using the heat transfer capability and total thermal resistance as the objective function and the structure parameters as the decision variable, the optimization design for the HP is performed using the Non-Dominated Sorting in Genetic Algorithms-II (NSGA-II). The results show that the optimal wick thickness and wick permeability to be a strong function of the heat flux. It is concluded that to have lower thermal resistance at lower heat fluxes for a screen mesh wick HP may have a large effective thermal conductivity, but have a small permeability. While at high heat transfer rate a small effective thermal conductivity, but a large permeability is recommended. The designer must always make trade-offs between these competing factors to obtain an optimal wick design. The investigations are aimed to determine working limits and thermal performance of HPs for low to medium operating temperature applications. [ABSTRACT FROM AUTHOR]

Aim Restrictive lung dysfunction ( RLD; defined as reduced forced vital capacity [ FVC] in the presence of normal forced expiratory volume in 1 s [ FEV1]/ FVC ratio) is highly prevalent in the elderly, and is associated with diabetes, metabolic syndrome ( MetS) and abdominal obesity. The aim of this study was to assess the relative contribution of diabetes, MetS and abdominal obesity in characterizing RLD in the elderly. Methods This was cross-sectional analysis of 192 consecutive, community-dwelling persons (mean age 70.8 ± 8 years). The participants were grouped according to the number of MetS components (i.e. 0, 1, 2, 3 or 4) and the presence of diabetes. According to the Adult Treatment Panel- III criteria, participants with three or four components were considered to be affected by MetS. Independent correlates of RLD and obstructive lung dysfunction ( OLD; FEV1/ FVC < 0.70) were assessed by logistic regression models. Results The mean age of the sample population was 70.8 years. FVC expressed as percent of the predicted value declined for an increasing number of MetS components ( P < 0.0001), but diabetes did not account for further ventilatory decline. Consistently, MetS ( OR 3.03, 95% CI 1.16-7.89) and abdominal obesity ( OR 4.89, 95% CI 1.17-20.3), but not diabetes, were independently associated with RLD. OLD did not worsen for an increasing number of MetS components and was only related to age ( OR 1.07, 95% CI 1.01-1.13) and smoking ( OR 1.04, 95% CI 1.01-1.06). Conclusions MetS and abdominal obesity, two conditions of prediabetes, but not diabetes itself, are closely associated with RLD. These conditions might be implicated in the pathogenesis of the RLD, which is frequently observed in diabetic patients. Geriatr Gerontol Int 2013; 13: 894-900. [ABSTRACT FROM AUTHOR]

Background: Audit is a clinical instrument of government characterized by a whole process of evaluation inter pares to improve medical behaviors in the clinical practice. Different endocrinopathies are underestimated in the clinical and diagnostics practice but they can be a real problem in patients admitted in the departments of Internal Medicine. The adrenal incidentaloma is an accidental discovery with an incidence equal to 4% in radiologic studies but it's rarely considereted in the internal disorders. In the departments of Internal Medicine are hospitalized each year approximately 1450,000 patients and 58,000 about them show a surrenalic lesion identified with CT or MRI as Adrenal Incidentaloma., Methods: Through a search in the radiological archives, were reviewed all abdominal CT performed in the year 2012 in 8 departments of Internal Medicine of 8 Italian public hospitals. They also examined all medical records of these patients to value clinical management of the adrenal masses and the real incidence of the adrenal incidentaloma., Results: Distribution of pathological results show an important incidence about adrenal incidentaloma in Italian patients although this pathology is represented as a rare disease and its clinical and economic burden are significant. Many questions remain unanswered as the association between duration and severity of the disease, morbidity and how the dimensions affecting it. These results need to be supported by important studies with long follow-up to realize an easy diagnosis., Conclusions: The results of this audit confirm the real incidence of this pathology in the internistic patients and the final target is to implement changes about therapeutic diagnostic pathway of the hospital patients in the internal medicine departments.

Background and Aim:  Post-discharge prophylaxis for venous thromboembolism (VTE) is a challenging issue in patients hospitalised in Internal Medicine Units (IMUs). The aim of this study was to evaluate the frequency and the factors associated with post-discharge prophylaxis for VTE in IMUs., Methods:  Multi-centre, retrospective study including consecutive patients who were admitted for any cause and discharged from an IMU., Results:  Overall, 3,740 patients (mean age 74.1 ± 15.7 years) were included in the study at 38 IMUs in Italy. At discharge, the percentage of patients receiving pharmacological thromboprophylaxis was 16.0% (20.1% after excluding patients treated with anticoagulants for indications other than VTE prophylaxis). At multivariable analysis, history of ischaemic stroke, hypomobility ≥ 7 days, central venous catheter, ≥ 10 versus ≤ 5 days of hospital stay, use of corticosteroids, cancer, history of falls, availability of a caregiver, infections and age were significantly associated with thromboprophylaxis, while an inverse correlation was observed with concomitant anti-platelet drugs and platelet count < 70,000/mm 3 . Patients with a Padua Prediction Score ≥ 4 versus < 4 and with an IMPROVE bleeding score ≥ 7 versus < 7 more frequently received prophylaxis at discharge (31.2% vs. 10.6%, p  < 0.0001, and 25.7% vs. 19.6%, p  = 0.028, respectively)., Conclusion:  In this study, one in five patients discharged from an Italian IMU received prophylaxis for VTE. The perceived thrombotic risk is significantly related to the use of prophylaxis., Competing Interests: None declared., (Georg Thieme Verlag KG Stuttgart · New York.)

This DIB article provides details about transcriptional and physiological response of Fe- and P-deficient white lupin roots, an extensive and complete description of plant response is shown in the research article "Physiological and transcriptomic data highlight common features between iron and phosphorus acquisition mechanisms in white lupin roots" Venuti et al. [1]. White lupin plants were grown under hydroponic system and three different nutritional regimes: Fe deficiency (-Fe), P deficiency (-P), or Fe and P sufficiency (+P + Fe). Depending on nutritional treatment, white lupin plants showed changes in the fresh weights, in root external acidification and Fe III -reductase activity. Moreover, the transcriptomic changes occurring in apices and clusters of Fe-deficient lupin roots were investigated and compared with differences of gene expression occurring in P-deficient plants (-P) and in Fe- and P-sufficient plants (+P + Fe). Transcriptomic data are available in the public repository Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo) under the series entry (GSE112220). The annotation, mapping and enrichment analyses of differentially modulated transcripts were assessed.