Dual source solar assisted heat pump model development, validation and comparison to conventional systems

This paper presents a new SAHP system integrated with hybrid photovoltaic/thermal panels (PVT). The main components of the system developed are a dual-source HP, PVT panels and two storage tanks. The use of two storage tanks allows to directly store the hot water for DHW if water temperature reaches the set-point or to send it to the cold storage. On the other side, the use of two heat exchangers on source side, allows the system to switch from air to the cold tank increasing system’s performances. In this work the developed system is compared with two conventional systems: an AWHP integrated with standard photovoltaic panels and an AWHP integrated with hybrid PVT panels for DHW production only. Those systems were investigated for a single family house, through one year simulation in the TRNSYS software. Control strategy, size of the tanks and number of panels were investigated with parametric studies. Thanks to the good results of the simulations, an experimental prototype has been designed and built. Data observed from first monitoring campaign highlighted better performances than expected. After a season of investigation and data analysis for the system, new findings will be illustrate

Influence of Comfort Expectations on Building Energy Need

Increase thermal comfort is considered as one of the main benefits of a deep renovation right after energy saving. However, an increase in thermal comfort could be seen as a behavioural change caused by the energy efficiency improvement that reduces expected energy saving: the so-called rebound effect. This paper shows how building energy need is correlated to comfort category, defined in EN 15251. The study is conducted via dynamic simulations performed by TRNSYS 17 software using 3D multi-zone models. Models are tailored on occupant behaviour and driven by thermal comfort constraints. Calculations of energy need for space heating and space cooling is done both before and after a deep renovation. The effect of building and user characteristics is evaluated too. Users are differentiated by number of persons and occupancy schedule. The relation between thermal comfort, set-point temperature and energy need is investigated, focusing attention on changes that occur after the building has been thermally insulated. Computational results are critically discussed and compared with an empirical study on building renovation that includes a survey on thermal comfort perception and user behaviour. Finally, rebound effect is discussed and its magnitude is evaluated

A simulation-based analysis of photovoltaic thermal hybrid solar collectors with a new TRNSYS type model

Nowadays buildings are responsible of 36% of CO2emissions and space heating and cooling alone accounts for 40% of the final energy consumption at European level. In this context, solar-assisted systems represent an important solution to support the decarbonisation pathways in residential sector. In this work, a novel lumped parameter simulation model for photovoltaic thermal hybrid solar collectors developed by Authors as a type of Transient System Simulation (TRNSYS) software is used to carry out computer simulations in different climatic conditions. The model is based on the electrical analogy method to solve the transient heat transfer problem and considers the effect of the thermal capacitances of the elements composing the photovoltaic thermal collector. The simulation tool was also validated with the experimental data in terms of both electrical and thermal power. In this work, a simulation-based analysis is carried out considering three climatic zones in order to evaluate the thermal performance of photovoltaic thermal hybrid solar collectors under different operating conditions

Field tests of a novel solar-assisted dual source multifunctional heat pump

In this paper, we present the results of field study concerning a novel solar-assisted dual-source multifunctional heat pump, installed in a detached house in Milan. The system couples hybrid photovoltaic/thermal (PVT) panels with multifunctional and reversible heat pump. The proposed system is equipped with an “air source” evaporator and a “water source” evaporator, connected in series and operated alternatively, based on the ambient conditions and system parameters. The “air source” evaporator is an external unit; conversely, the “water source” evaporator is connected with a storage tank, fed by the PVT system. The PVT system is connected with the heat pump by two storage tanks to be used to produce domestic hot water and to be used in “water source” evaporator. Based on the operating conditions, the hot water is sent to one of the storage tank. The proposed system has been tested experimentally; the results show that the system was able to maintain high efficiency in the different seasons and was able to produce domestic hot water. It was found that the use of the “water source” evaporator was able to compensate the performance degradation of the “air source” source evaporator caused by the low ambient temperature

Lymphedema and nutrition: A review

Nutrition is considered a basic component in the management of any vascular disease. Lymphedema is characterised by an increase of interstitial fluid due to a lymphatic system morphological and/or functional alteration. Therapeutic management of lymphedema includes a multi-faceted approach based on compression and physiotherapy mainly. Weight control and antiinflammatory and anti-edema diet are two additional necessary components of the holistic therapy in presence of primary or secondary limb lymphedema. This narrative review provides the available information derived from the scientific literature on nutrition in lymphedema, which anyway lacks robust evidence. Additional information and speculations are provided on the role of food, diet, nutraceuticals and fasting on the basic processes at the root of the chronic progressive degeneration of tissue lymph stasis, i.e. weight excess, inflammation, edema, fibroadiposis. More targeted and randomized studies are needed in order to assess and standardise the obvious, so far neglected, role of nutrition in lymphedema patients

A Hydrogenated amorphous silicon detector for Space Weather Applications

The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for monitoring in space solar flares and the evolution of large energetic proton events up to hundreds of MeV. The a-Si:H presents an excellent radiation hardness and finds application in harsh radiation environments for medical purposes, for particle beam characterization and in space weather science and applications. The critical flux detection threshold for solar X rays, soft gamma rays, electrons and protons is discussed in detail.Comment: 32 pages, 13 figures, submitted to Experimental Astronom

An explainable model of host genetic interactions linked to COVID-19 severity

We employed a multifaceted computational strategy to identify the genetic factors contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing (WES) dataset of a cohort of 2000 Italian patients. We coupled a stratified k-fold screening, to rank variants more associated with severity, with the training of multiple supervised classifiers, to predict severity based on screened features. Feature importance analysis from tree-based models allowed us to identify 16 variants with the highest support which, together with age and gender covariates, were found to be most predictive of COVID-19 severity. When tested on a follow-up cohort, our ensemble of models predicted severity with high accuracy (ACC = 81.88%; AUCROC = 96%; MCC = 61.55%). Our model recapitulated a vast literature of emerging molecular mechanisms and genetic factors linked to COVID-19 response and extends previous landmark Genome-Wide Association Studies (GWAS). It revealed a network of interplaying genetic signatures converging on established immune system and inflammatory processes linked to viral infection response. It also identified additional processes cross-talking with immune pathways, such as GPCR signaling, which might offer additional opportunities for therapeutic intervention and patient stratification. Publicly available PheWAS datasets revealed that several variants were significantly associated with phenotypic traits such as "Respiratory or thoracic disease", supporting their link with COVID-19 severity outcome.A multifaceted computational strategy identifies 16 genetic variants contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing dataset of a cohort of Italian patients

Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19

Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage

Gain- and Loss-of-Function CFTR Alleles Are Associated with COVID-19 Clinical Outcomes

Carriers of single pathogenic variants of the CFTR (cystic fibrosis transmembrane conductance regulator) gene have a higher risk of severe COVID-19 and 14-day death. The machine learning post-Mendelian model pinpointed CFTR as a bidirectional modulator of COVID-19 outcomes. Here, we demonstrate that the rare complex allele [G576V;R668C] is associated with a milder disease via a gain-of-function mechanism. Conversely, CFTR ultra-rare alleles with reduced function are associated with disease severity either alone (dominant disorder) or with another hypomorphic allele in the second chromosome (recessive disorder) with a global residual CFTR activity between 50 to 91%. Furthermore, we characterized novel CFTR complex alleles, including [A238V;F508del], [R74W;D1270N;V201M], [I1027T;F508del], [I506V;D1168G], and simple alleles, including R347C, F1052V, Y625N, I328V, K68E, A309D, A252T, G542*, V562I, R1066H, I506V, I807M, which lead to a reduced CFTR function and thus, to more severe COVID-19. In conclusion, CFTR genetic analysis is an important tool in identifying patients at risk of severe COVID-19

The polymorphism L412F in TLR3 inhibits autophagy and is a marker of severe COVID-19 in males

The polymorphism L412F in TLR3 has been associated with several infectious diseases. However, the mechanism underlying this association is still unexplored. Here, we show that the L412F polymorphism in TLR3 is a marker of severity in COVID-19. This association increases in the sub-cohort of males. Impaired macroautophagy/autophagy and reduced TNF/TNFα production was demonstrated in HEK293 cells transfected with TLR3L412F-encoding plasmid and stimulated with specific agonist poly(I:C). A statistically significant reduced survival at 28 days was shown in L412F COVID-19 patients treated with the autophagy-inhibitor hydroxychloroquine (p = 0.038). An increased frequency of autoimmune disorders such as co-morbidity was found in L412F COVID-19 males with specific class II HLA haplotypes prone to autoantigen presentation. Our analyses indicate that L412F polymorphism makes males at risk of severe COVID-19 and provides a rationale for reinterpreting clinical trials considering autophagy pathways. Abbreviations: AP: autophagosome; AUC: area under the curve; BafA1: bafilomycin A1; COVID-19: coronavirus disease-2019; HCQ: hydroxychloroquine; RAP: rapamycin; ROC: receiver operating characteristic; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; TLR: toll like receptor; TNF/TNF-α: tumor necrosis factor