Experimental Analysis of Heat Transfer in Passive Latent Heat Thermal Energy Storage Systems for CSP Plants

Abstract Thermal energy storage is a key factor for efficiency, dispatchability and economic sustainability of concentrated solar plants. The latent heat storage systems could ensure a significant reduction in construction costs and environmental impact, because of its high storage energy density. In LHTES, the heat transfer between the heat transfer fluid and the storage system is strongly limited by the reduced thermal conductivity of the storage media. For operating temperatures between 200 and 600 °C, the most used storage media are salts. In order to evaluate solutions which promote the thermal conductivity, by increasing the exchange surface and/or the addition of nanoparticles to the storage media, Enea set up a small facility to test some storage concepts. In this facility, a diathermic oil flows through three elementary "shell-and-tube" storage systems, connected in series, reaching a maximum temperature of about 280 °C. The elementary storage systems are filled with a mixture of sodium and potassium nitrates salts, which melt at about 225 °C. Moreover a small percentage of alumina and silica nanoparticles were added to this mixture. The results of the experiments show an increase of the thermal diffusivity of the medium not only for the presence of fins on the heat transfer tubes but also because of convective flows within the melted fraction were established. These phenomena strongly reduce the charging times of the system (by about 30%). Instead, the presence of nanoparticles increases the thermal capacity and the thermal conductivity of the storage system but seems not to have a relevant effect on the thermal diffusivity of the mixture. This behavior depends on the type of used nanoparticles, which can significantly change over time some characteristics of the storage medium, in which they are dispersed, leaving other characteristics unchanged, according to mechanisms which are still to be well understood

Optimizing the Sampling Area across an Old-Growth Forest via UAV-Borne Laser Scanning, GNSS, and Radial Surveying

Aboveground biomass, volume, and basal area are among the most important structural attributes in forestry. Direct measurements are cost-intensive and time-consuming, especially for old-growth forests exhibiting a complex structure over a rugged topography. We defined a methodology to optimize the plot size and the (total) sampling area, allowing for structural attributes with a tolerable error to be estimated. The plot size was assessed by analyzing the semivariogram of a CHM model derived via UAV laser scanning, while the sampling area was based on the calculation of the absolute relative error as a function of allometric relationships. The allometric relationships allowed the structural attributes from trees’ height to be derived. The validation was based on the positioning of a number of trees via total station and GNSS surveys. Since high trees occlude the GNSS signal transmission, a strategy to facilitate the positioning was to fix the solution using the GLONASS constellation alone (showing the highest visibility during the survey), and then using the GPS constellation to increase the position accuracy (up to PDOP~5−10). The tree heights estimated via UAV laser scanning were strongly correlated (r2 = 0.98, RMSE = 2.80 m) with those measured in situ. Assuming a maximum absolute relative error in the estimation of the structural attribute (20% within this work), the proposed methodology allowed the portion of the forest surface (≤60%) to be sampled to be quantified to obtain a low average error in the calculation of the above mentioned structural attributes (≤13

Gestione sostenibile delle foreste Mediterranee e uso energetico delle biomasse forestali residuali

he book describes the reasons that led the Regional Department of Rural and Territorial Development to take part in the PROFORBIOMED Project. They can be summarized by the need to dispose of a tool for the sustainable management of all the state-owned forests of the Region. As a matter of fact, the Project aims at developing a model of sustainable forest management, through the recovery and reuse of wood scraps from ordinary silvicultural operations, to be used for the production of power and heat inside of a process adopting natural renewable energy sources. The main actions taken and the methodologies adopted are described, as well as the principles and instruments required for the setting up and execution of the work. Some of the most relevant are: the drafting of “Forest Management Plans”, the “Short Supply Chain” and the “Biomass Traceability Protocol”, together with the application of “Best Practices” of Management and the “Monitoring of impacts” caused by the woody biomass extraction procedures. The “forest – wood – energy” chain developed and proposed is exclusively related to the territory pertaining to one municipality, and with CHP plants fed with biomass exclusively produced within the territory of each municipality, in strict compliance with the “sustainable forest management” principles, as well as with the fundamental principle of “short supply chain”. For these reasons the CHP plans proposed shall be sized according to the biomass available in each municipality, with the possibility of integrating residual forest biomass with other waste wood resources potentially available in the territory and coming from prunings in agricultural activities. Therefore, the replicable model prepared and proposed by PROFORBIOMED aims at appraising from the economic point of view a waste product, such is currently considered the residual forest biomass from the forests of Sicily, and at the same time significantly improving the natural environment, thanks to the reduction in oil consumption

Endurance training damages small airway epithelium in mice.

RATIONALE: In athletes, airway inflammatory cells were found to be increased in induced sputum or bronchial biopsies. Most data were obtained after exposure to cold and dry air at rest or during exercise. Whether training affects epithelial and inflammatory cells in small airways is unknown. OBJECTIVES: To test whether endurance training under standard environmental conditions causes epithelial damage and inflammation in the small airways of mice. METHODS AND MEASUREMENTS: Formalin-fixed, paraffin-embedded lung sections were obtained in sedentary (n = 14) and endurance-trained (n = 16) Swiss mice at baseline and after 15, 30, and 45 days of training. The following variables were assessed (morphometry and immunohistochemistry) in small airways (basement membrane length < 1 mm): (1) integrity, proliferation, and apoptosis of bronchiolar epithelium; and (2) infiltration, activation, and apoptosis of inflammatory cells. MAIN RESULTS: Compared with sedentary mice, bronchiolar epithelium of trained mice showed progressive loss of ciliated cells, slightly increased thickness, unchanged goblet cell number and appearance, and increased apoptosis and proliferation (proliferating cell nuclear antigen) (p < 0.001 for all variables). Leukocytes (CD45(+) cells) infiltrated airway walls (p < 0.0001) and accumulated within the lumen (p < 0.001); however, apoptosis of CD45(+) cells did not differ between trained and sedentary mice. Nuclear factor-kappaB translocation and inhibitor-alpha of NF-kappaB (IkappaBalpha) phosphorylation were not increased in trained compared with sedentary mice. CONCLUSIONS: Bronchiolar epithelium showed damage and repair associated with endurance training. Training increased inflammatory cells in small airways, but inflammatory activation was not increased. These changes may represent an adaptive response to increased ventilation during exercise

Strategies for the re-naturalization of reforestation: the case study of the Sicilian clay hills

Over the last decades many areas have been reforested along Europe, with great proportion been made with exotic species. Very often these reforestations do not evolve in more diverse configurations, where some kind of management can be necessary to try to enhance this evolution. The hole is a silvicultural technique consisting in open small gaps to create favourable conditions for the establishment of other species changing the former structure, microclimate and competitive conditions mirroring this natural processes that occurs in structured and mature forests. The best size of the hole seems to be around 500 m\ub2, as small holes may not change significantly the conditions and larger holes seems to favour degradation processes like soil erosion and loss of organic layers. The afforestaion of the Santa Ninfa Natural Reserve (Trapani Province, W-Sicily) were made using essentially Pinus spp. and Eucalyptus camaldulensis. Particularly, this last specie occur in high density monospecific forest structure covering 19 ha (8% of the reserve), where practically no kind of management has been made until now and very few natural regenerations is observed. The aim of the study was to verify the effectiveness of the restoration actions combining the hole technique and planting native species with different management levels

Hemopoietic and angiogenetic progenitors in healthy athletes: different responses to endurance and maximal exercise

J Appl Physiol. 2010 Jul;109(1):60-7. Epub 2010 May 6. Hemopoietic and angiogenetic progenitors in healthy athletes: different responses to endurance and maximal exercise. Bonsignore MR, Morici G, Riccioni R, Huertas A, Petrucci E, Veca M, Mariani G, Bonanno A, Chimenti L, Gioia M, Palange P, Testa U. SourceBiomedical Department, Internal and Specialistic Medicine (DIBIMIS), Section of Pneumology, University of Palermo, Via Trabucco, 180, 90146 Palermo, Italy. [email protected] Abstract The effects of endurance or maximal exercise on mobilization of bone marrow-derived hemopoietic and angiogenetic progenitors in healthy subjects are poorly defined. In 10 healthy amateur runners, we collected venous blood before, at the end of, and the day after a marathon race (n = 9), and before and at the end of a 1.5-km field test (n = 8), and measured hemopoietic and angiogenetic progenitors by flow cytometry and culture assays, as well as plasma or serum concentrations of several cytokines/growth factors. After the marathon, CD34(+) cells were unchanged, whereas clonogenetic assays showed decreased number of colonies for both erythropoietic (BFU-E) and granulocyte-monocyte (CFU-GM) series, returning to baseline the morning post-race. Conversely, CD34(+) cells, BFU-E, and CFU-GM increased after the field test. Angiogenetic progenitors, assessed as CD34(+)KDR(+) and CD133(+)VE-cadherin(+) cells or as adherent cells in culture expressing endothelial markers, increased after both endurance and maximal exercise but showed a different pattern between protocols. Interleukin-6 increased more after the marathon than after the field test, whereas hepatocyte growth factor and stem cell factor increased similarly in both protocols. Plasma levels of angiopoietin (Ang) 1 and 2 increased after both types of exercise, whereas the Ang-1-to-Ang-2 ratio or vascular endothelial growth factor-A were little affected. These data suggest that circulating hemopoietic progenitors may be utilized in peripheral tissues during prolonged endurance exercise. Endothelial progenitor mobilization after exercise in healthy trained subjects appears modulated by the type of exercise. Exercise-induced increase in growth factors suggests a physiological trophic effect of exercise on the bone marrow. PMID:20448032[PubMed - indexed for MEDLINE

Emergenze vegetali dell'Isola di Lampedusa

Per la peculiarit\ue0 storica, geografica ed ambientale l\u2019Isola di Lampedusa, e vista l\u2019estrema frammentariet\ue0 delle formazioni preforestali, l\u2019esiguit\ue0 dei popolamenti (e degli individui) delle specie legnose assumono un valore scientifico e conservazionistico particolarmente elevato. Per queste ragioni \ue8 stato fatto un censimento eseguito con strumentazione GPS. Sull\u2019isola crescono diverse specie di rilevante interesse conservazionistico, numerose sono infatti le specie endemiche, esclusive, rare e/o a rischio di estinzione perch\ue9 legate a habitat molto vulnerabili e localizzati. A questa ragione d\u2019interesse generale per questi taxa si somma il fatto che buona parte delle specie arboree tipiche della vegetazione primaria dell\u2019isola, il pi\uf9 delle volte sopravvivono localmente con popolamenti costituiti da pochissimi (e talora singoli!) individui. Juniperus turbinata e Olea europaea var. sylvestris sono le due specie forestali di gran lunga pi\uf9 comuni tra quelle indagate . Meno positivo \ue8 il risultato dell\u2019analisi della rinnovazione, che ha permesso di individuare appena una trentina di giovani individui di ginepro e nessuno di olivastro. La presenza delle due specie sull\u2019isola risulta circoscritta esclusivamente ai valloni stretti ed incisi che sboccano sulla costa meridionale dell\u2019isola, disegnando un complesso sistema in cui si alternano profonde insenature e pendii rocciosi subpianeggianti. Per ambedue le specie si \ue8 registrata una netta prevalenza (ca. 80% dei ginepri e ca. 95% degli olivastri!) in corrispondenza delle esposizioni meridionali dell\u2019isola che, sebbene pi\uf9 soleggiate godono dell\u2019effetto benefico dei venti umidi provenienti da meridione

A new approach in the monitoring of the phytosanitary conditions of forests: the case of oak and beech stands in the Sicilian Regional Parks

L'obiettivo del presente studio è stato quello di esaminare lo stato fitosanitario delle quercete e faggete dei tre Parchi Regionali Siciliani (Parco dell'Etna, Parco delle Madonie, Parco dei Nebrodi). Lo studio è stato condotto individuando delle aree di saggio, popolamenti forestali omogenei sotto l'aspetto floristico, ecologico e fitosanitario. Complessivamente sono state delimitate 81 aree di saggio, di cui 54 quercete e 27 faggete. La condizione fitosanitaria di ogni essenza arborea all'interno della rispettiva area di saggio è stata espressa con un indice numerico denominato “classe fitosanitaria” (PC). I popolamenti di quercia hanno mostrato un elevato grado di sofferenza, con alberi sintomatici nell’85% delle aree di saggio. I popolamenti di faggio hanno mostrato una situazione di maggiore stabilità, ad eccezione delle faggete del parco dei Nebrodi che apparivano molto degradate. Sul genere Quercus, sono stati osservati sintomi di infezioni di patogeni fungini comuni nelle foreste delle aree temperate e Mediterranee, quali Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides ed Armillaria sp., mentre su faggio sono state osservate infezioni di Biscogniauxia nummularia, Fomes fomentarius e Neonectria radicicola. Sono state altresì individuate 22 aree che vengono proposte come aree di saggio permanenti dello stato fitosanitario delle foreste nei tre parchi.The objective of this study was to investigate the health conditions of oak and beech stands in the three Regional Parks of Sicily (Etna, Madonie and Nebrodi). A total of 81 sampling areas were investigated, 54 in oak stands and 27 in beech stands. The phytosanitary conditions of each tree within the respective sampling area was expressed with a synthetic index namely phytosanitary class (PC). Oak stands showed severe symptoms of decline, with 85% of the sampling areas including symptomatic trees. In general, beech stands were in better condition, with the exception of Nebrodi Park, where trees showed severe symptoms of decline. On oak trees, infections of fungal pathogens were also observed, including Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides and Armillaria sp. By contrast, on beech trees Biscogniauxia nummularia, Fomes fomentarius and Neonectria radicicola were recognized. Furthermore, twenty-two permanent sampling areas were delimited with the aim of monitoring regularly the health conditions of forests in these three parks

Sviluppo di modelli innovativi per il monitoraggio multiscala degli indicatori di servizi ecosistemici nelle foreste Mediterranee (Progetto MIMOSE).

Gli ecosistemi, attraverso le loro funzioni, forniscono un ampio range di beni e servizi, che risultano fondamentali per il benessere dell’uomo. Questi vengono complessivamente definiti Servizi Ecosistemici (SE). I SE possono essere intesi come un flusso di valori verso la società, quale risultato dello stato e della quantità del capitale naturale disponibile. Il mantenimento degli stocks del capitale naturale può permettere di prevedere i flussi futuri dei SE, assicurando quindi il benessere dell’uomo per le generazioni future. Il progetto FIRB 2012 MIMOSE è finalizzato allo sviluppo di un approccio multiscala innovativo e all’implementazione di strumenti previsionali volti al monitoraggio dei SE in habitat forestali Mediterranei. Un set di indicatori viene considerato per stimare i SE forniti dalle foreste, sviluppando strumenti integrati per il loro monitoraggio multiscala. Le attività di ricerca vertono allo sviluppo di un metodo statistico innovativo per la stima spaziale degli indicatori di SE, sulla base di dati disponibili a diversi livelli di scala spaziale. Sono realizzate mappe wall-to-wall per la fornitura dei SE, derivate da diversi domini spaziali, dal livello di scala locale sino ad aree forestali di grande estensione. I dati sugli indicatori dei SE sono forniti nel contesto di attività di campionamento già stabilite (raccolta dati a livello di aree di saggio e di popolamento), per poi applicare tecniche di spazializzazione per aggregare i dati raccolti su scala locale a livelli di scala più ampia (paesaggio, scala regionale); l’approccio utilizzato viene valutato attraverso l’applicazione di strumenti di monitoraggio in un set di aree test. Si procede quindi alla valutazione dei cambiamenti spazio-temporali nella previsione dei SE, considerando indicatori sensibili alla gestione forestale, ovvero capaci di evidenziare cambiamenti nella previsione di fornitura di beni e servizi ad opera dei sistemi forestali, in relazione a differenti scenari gestionali, con l’obiettivo di fornire indicazioni ai gestori forestali ed alle comunità locali per l’applicazione di pratiche di gestione che possano mantenere o incrementare la fornitura dei SE in un preciso contesto territoriale. Questo progetto permette di realizzare un’attenta analisi dei gaps esistenti negli attuali schemi di inventariazione in relazione alla fornitura dei SE, con l’obiettivo di dare indicazioni utili all’implementazione ed integrazione degli stessi mediante individuazione di nuovi indicatori, nell’ottica di una gestione forestale sostenibile. Le attività di ricerca in corso possono concretamente contribuire all’incorporazione dei SE nei processi decisionali connessi alla gestione dei paesaggi forestali, fornendo un’opportunità per comprendere la congruenza tra i diversi SE negli ambienti forestali