Economia agraria e pianificazione economica territoriale nel Parco nazionale del Sagarmatha (Everest, Nepal)

In questo quaderno vengono pubblicati i contributi scientifici che sono stati presentati alla conferenza nazionale avente per tema “Economia agraria e pianificazione economica territoriale nel Parco Nazionale del Sagarmatha (Everest, Nepal)”, che si è tenuta alla facoltà di Economia dell’Università degli Studi di Perugia, il 25 e 26 settembre 2008. English: This paper collects research works presented at a national conference on the theme "Agricultural Economy, Environmental Economics and Land Use Planning in the Sagarmatha National Park (Everest, Nepal)" held at the Faculty of Economics of the University of Perugia, September, 25th-26th, 2008economia agraria, gestione ambientale, parco naturale, pianificazione economica territoriale, sviluppo economico sostenibile, Sagarmatha National Park

Strumenti e metodi innovativi per la gestione degli interventi di manutenzione effettuati su impianti fotovoltaici al fine del mantenimento della loro efficienza e funzionalità.

Nel corso della loro vita utile, gli impianti fotovoltaici sono soggetti ad un degrado continuo dei componenti con conseguente decremento della produzione attesa, nonché a guasti, avarie o malfunzionamenti. Per monitorare le prestazioni nel tempo e per individuare eventuali diminuzioni di performance, vengono utilizzate tecniche quali l’analisi dei dati di produzione e l’esecuzione di prove strumentali in campo. Data la carenza di procedure circa le tecniche sopra menzionate, sia nella modalità di esecuzione sia nella rappresentazione dei risultati, emersa dallo studio dello stato dell’arte, il principale obiettivo di questo lavoro è quello di definire un processo organico per indagare le performance d’impianto e per elaborare proposte di intervento atte ad incrementarne le prestazioni. A partire dalle analisi condotte sui dati provenienti da impianti fotovoltaici reali e dalle prove strumentali in campo, lo studio propone procedure per l’analisi dei di monitoraggio e per l’individuazione e l’esecuzione delle prove da svolgere e la successiva interpretazione e rappresentazione dei risultati. Inoltre, definisce proposte di intervento da mettere in atto per risolvere eventuali criticità emerse nelle fasi di indagine. In aggiunta, il presente lavoro ha perseguito due obiettivi parallelamente a quello principale sopra esposto. Il primo obiettivo ha riguardato l’esecuzione di “curve I-V” (corrente-tensione) su alcuni moduli fotovoltaici mediante l’impiego di un dispositivo per i flash test e l’individuazione della correlazione quantitativa tra alcuni tipici difetti riscontrabili con la termografia ad infrarossi su un modulo e il decremento di potenza associato. Il secondo obiettivo ha visto un focus all’accuratezza delle curve I-V attraverso il confronto tra i risultati delle misure in campo e quelli ottenuti in laboratorio attraverso l’impiego del flash-tester; la conclusione è la scarsa affidabilità delle curve I-V svolte in campo come strumento per valutare l’underperformance dell’impianto.During their lifetime, photovoltaic plants are subject to a normal degradation of their components, and they are consequently characterized by decrease of the expected production. Techniques such as production data analysis and instrumental tests are performed in order to monitor performance over time and to identify power decrease. Examining the state of the art, a lack of procedures related to the abovementioned techniques, both in the execution mode and in the results representation, has emerged. The main aim of this work is to define an organic process to investigate the performance of photovoltaic plants and to elaborate intervention proposals in order to increase their production. Based on the analyses that have been performed on the data from real photovoltaic plants and instrumental tests, this work defines the procedures to analyze the data extracted from the monitoring systems and proposes the procedures to identify and perform the tests to be carried out and the subsequent interpretation and representation of the results. In addition, the present work has pursued two other objectives parallel to the main one described above. Using the I-V curves determined by means of an indoor solar flash test device, it has been possible to evaluate production loss associated to specific thermal defects that can be detected through infrared thermography on the photovoltaic modules. A specific focus was also dedicated to the accuracy of I-V curves through the comparison between the measurements that are performed in the field and those obtained in the laboratory by means of an indoor solar flash test device. This study has led to a relevant conclusion: the I-V curves, that are carried out in the field, are characterized by an inadequate reliability and they cannot be considered a valid technique to evaluate the underperformance of a photovoltaic plant

Structural changes and dynamic behaviour of vanadium oxide-based catalysts for gas-phase selective oxidations

Selective oxidation is one of the simplest functionalization methods and essentially all monomers used in manufacturing artificial fibers and plastics are obtained by catalytic oxidation processes. Formally, oxidation is considered as an increase in the oxidation number of the carbon atoms, then reactions such as dehydrogenation, ammoxidation, cyclization or chlorination are all oxidation reactions. In this field, most of processes for the synthesis of important chemicals used vanadium oxide-based catalysts. These catalytic systems are used either in the form of multicomponent mixed oxides and oxysalts, e.g., in the oxidation of n-butane (V/P/O) and of benzene (supported V/Mo/O) to maleic anhydride, or in the form of supported metal oxide, e.g., in the manufacture of phthalic anhydride by o-xylene oxidation, of sulphuric acid by oxidation of SO2, in the reduction of NOx with ammonia and in the ammoxidation of alkyl aromatics. In addition, supported vanadia catalysts have also been investigated for the oxidative dehydrogenation of alkanes to olefins , oxidation of pentane to maleic anhydride and the selective oxidation of methanol to formaldehyde or methyl formate [1]. During my PhD I focused my work on two gas phase selective oxidation reactions. The work was done at the Department of Industrial Chemistry and Materials (University of Bologna) in collaboration with Polynt SpA. Polynt is a leader company in the development, production and marketing of catalysts for gas-phase oxidation. In particular, I studied the catalytic system for n-butane oxidation to maleic anhydride (fluid bed technology) and for o-xylene oxidation to phthalic anhydride. Both reactions are catalyzed by systems based on vanadium, but catalysts are completely different. Part A is dedicated to the study of V/P/O catalyst for n-butane selective oxidation, while in the Part B the results of an investigation on TiO2-supported V2O5, catalyst for o-xylene oxidation are showed. In Part A, a general introduction about the importance of maleic anhydride, its uses, the industrial processes and the catalytic system are reported. The reaction is the only industrial direct oxidation of paraffins to a chemical intermediate. It is produced by n-butane oxidation either using fixed bed and fluid bed technology; in both cases the catalyst is the vanadyl pyrophosphate (VPP). Notwithstanding the good performances, the yield value didn’t exceed 60% and the system is continuously studied to improve activity and selectivity. The main open problem is the understanding of the real active phase working under reaction conditions. Several articles deal with the role of different crystalline and/or amorphous vanadium/phosphorous (VPO) compounds. In all cases, bulk VPP is assumed to constitute the core of the active phase, while two different hypotheses have been formulated concerning the catalytic surface. In one case the development of surface amorphous layers that play a direct role in the reaction is described, in the second case specific planes of crystalline VPP are assumed to contribute to the reaction pattern, and the redox process occurs reversibly between VPP and VOPO4. Both hypotheses are supported also by in-situ characterization techniques, but the experiments were performed with different catalysts and probably under slightly different working conditions. Due to complexity of the system, these differences could be the cause of the contradictions present in literature. Supposing that a key role could be played by P/V ratio, I prepared, characterized and tested two samples with different P/V ratio. Transformation occurring on catalytic surfaces under different conditions of temperature and gas-phase composition were studied by means of in-situ Raman spectroscopy, trying to investigate the changes that VPP undergoes during reaction. The goal is to understand which kind of compound constituting the catalyst surface is the most active and selective for butane oxidation reaction, and also which features the catalyst should possess to ensure the development of this surface (e.g. catalyst composition). On the basis of results from this study, it could be possible to project a new catalyst more active and selective with respect to the present ones. In fact, the second topic investigated is the possibility to reproduce the surface active layer of VPP onto a support. In general, supportation is a way to improve mechanical features of the catalysts and to overcome problems such as possible development of local hot spot temperatures, which could cause a decrease of selectivity at high conversion, and high costs of catalyst. In literature it is possible to find different works dealing with the development of supported catalysts, but in general intrinsic characteristics of VPP are worsened due to the chemical interaction between active phase and support. Moreover all these works deal with the supportation of VPP; on the contrary, my work is an attempt to build-up a V/P/O active layer on the surface of a zirconia support by thermal treatment of a precursor obtained by impregnation of a V5+ salt and of H3PO4. In-situ Raman analysis during the thermal treatment, as well as reactivity tests are used to investigate the parameters that may influence the generation of the active phase. Part B is devoted to the study of o-xylene oxidation of phthalic anhydride; industrially, the reaction is carried out in gas-phase using as catalysts a supported system formed by V2O5 on TiO2. The V/Ti/O system is quite complex; different vanadium species could be present on the titania surface, as a function of the vanadium content and of the titania surface area: (i) V species which is chemically bound to the support via oxo bridges (isolated V in octahedral or tetrahedral coordination, depending on the hydration degree), (ii) a polymeric species spread over titania, and (iii) bulk vanadium oxide, either amorphous or crystalline. The different species could have different catalytic properties therefore changing the relative amount of V species can be a way to optimize the catalytic performances of the system. For this reason, samples containing increasing amount of vanadium were prepared and tested in the oxidation of o-xylene, with the aim of find a correlations between V/Ti/O catalytic activity and the amount of the different vanadium species. The second part deals with the role of a gas-phase promoter. Catalytic surface can change under working conditions; the high temperatures and a different gas-phase composition could have an effect also on the formation of different V species. Furthermore, in the industrial practice, the vanadium oxide-based catalysts need the addition of gas-phase promoters in the feed stream, that although do not have a direct role in the reaction stoichiometry, when present leads to considerable improvement of catalytic performance. Starting point of my investigation is the possibility that steam, a component always present in oxidation reactions environment, could cause changes in the nature of catalytic surface under reaction conditions. For this reason, the dynamic phenomena occurring at the surface of a 7wt% V2O5 on TiO2 catalyst in the presence of steam is investigated by means of Raman spectroscopy. Moreover a correlation between the amount of the different vanadium species and catalytic performances have been searched. Finally, the role of dopants has been studied. The industrial V/Ti/O system contains several dopants; the nature and the relative amount of promoters may vary depending on catalyst supplier and on the technology employed for the process, either a single-bed or a multi-layer catalytic fixed-bed. Promoters have a quite remarkable effect on both activity and selectivity to phthalic anhydride. Their role is crucial, and the proper control of the relative amount of each component is fundamental for the process performance. Furthermore, it can not be excluded that the same promoter may play different role depending on reaction conditions (T, composition of gas phase..). The reaction network of phthalic anhydride formation is very complex and includes several parallel and consecutive reactions; for this reason a proper understanding of the role of each dopant cannot be separated from the analysis of the reaction scheme. One of the most important promoters at industrial level, which is always present in the catalytic formulations is Cs. It is known that Cs plays an important role on selectivity to phthalic anhydride, but the reasons of this phenomenon are not really clear. Therefore the effect of Cs on the reaction scheme has been investigated at two different temperature with the aim of evidencing in which step of the reaction network this promoter plays its role

Weather Simulation of Extreme Precipitation Events Inducing Slope Instability Processes over Mountain Landscapes

Mountain landscapes are characterised by a very variable environment under different points of view (topography, geology, meteorological conditions), and they are frequently affected by mass wasting processes. A debris flow that occurred along the Croso stream, located in the Italian Lepontine Alps in the Northern Ossola Valley, during summer 2019, was analysed from a geological/geomorphological and meteorological point of view. The debris flow was triggered by an intense precipitation event that heavily impacted a very restricted area over the course of three hours. A previous debris flow along the same stream occurred in Autumn 2000, but it was related to an intense and prolonged rainfall event. The slope was characterised in terms of sediment connectivity, and data were retrieved and elaborated from the Web-GIS (Web-Geographic Information System) database of the IFFI-Italian Landslide Inventory and historical archives of landslides. Both the events were analysed through the weather research and forecasting (WRF) model applying a very high horizontal grid spacing with the aim of catching the precipitation patterns and timings. The obtained results are compared with the observed precipitation at a selection of weather stations in the area. The simulation of WRF that measured the timing in total precipitation and in its minor steps could be considered reliable. Moreover, it reveals to be appropriate for detecting in advance the meteorological conditions potentially triggering mass-wasting processes affecting slopes featuring high connectivity conditions and lithotypes characterised by a high Landslide Susceptibility Index

Emotional management and biological markers of dietetic regimen in chronic kidney disease patients

The aim of the study was to investigate the association between psychological characteristics and biological markers of adherence in chronic kidney disease patients receiving conservative therapy, hemodialysis, peritoneal dialysis (PD), or kidney transplantation. Seventy-nine adult patients were asked to complete the following questionnaires: Toronto Alexithymia scale, Snaith–Hamilton Pleasure Scale, and Short Form Health Survey. Biological markers of adherence to treatment were measured. Peritoneal dialysis patients showed a lower capacity to feel pleasure from sensorial experience (p = .011) and a higher values of phosphorus compared to the other patients’ groups (p = .0001). The inability to communicate emotions was negatively correlated with hemoglobin levels (r = −(0).69; p = .001) and positively correlated with phosphorus values in the PD patients (r = .45; p = .050). Findings showed higher psychological impairments and a lower adherence to the treatment in PD patients and suggest the implication of emotional competence in adherence to treatment.The aim of the study was to investigate the association between psychological characteristics and biological markers of adherence in chronic kidney disease patients receiving conservative therapy, hemodialysis, peritoneal dialysis (PD), or kidney transplantation. Seventy-nine adult patients were asked to complete the following questionnaires: Toronto Alexithymia scale, Snaith-Hamilton Pleasure Scale, and Short Form Health Survey. Biological markers of adherence to treatment were measured. Peritoneal dialysis patients showed a lower capacity to feel pleasure from sensorial experience (p = .011) and a higher values of phosphorus compared to the other patients' groups (p = .0001). The inability to communicate emotions was negatively correlated with hemoglobin levels (r = -(0).69; p = .001) and positively correlated with phosphorus values in the PD patients (r = .45; p = .050). Findings showed higher psychological impairments and a lower adherence to the treatment in PD patients and suggest the implication of emotional competence in adherence to treatment

Correction Procedures for Temperature and Irradiance of Photovoltaic Modules: Determination of Series Resistance and Temperature Coefficients by Means of an Indoor Solar Flash Test Device

none5openLuciani, Silvia; Coccia, Gianluca; Tomassetti, Sebastiano; Pierantozzi, Mariano; Di Nicola, GiovanniLuciani, Silvia; Coccia, Gianluca; Tomassetti, Sebastiano; Pierantozzi, Mariano; Di Nicola, Giovann

Efeitos da Expansão da Cana de Açúcar no Sudeste do Mato Grosso do Sul e Possíveis Caminhos para uma Agenda Sustentável

The Brazilian Alcohol program (Pró-Álcool) is pointed out as a sustainable development tool.However, the negative impacts produced throughout its production can minimize its benefits. Inrecent years, the area under sugar cane increased from 105 thousands hectares to more than700 thousands hectares in the state of Mato Grosso do Sul. Nonetheless, little is known about theimpacts faced by this region of Brazil. The goal of this project was to evaluate the sugarcaneimpacts in the Southwestern region of that state, through interviews, reports analysis and in locovisits. The better protection of Areas Legally Protected and the incensement in the number ofenterprises formally registered are within the positive effects. Related to the negative impacts,stands out conflicts related to Indigenous Lands and issues related to the public health system inthe cities analysed. The results point out the need, for the public governments create andcoordinate actions, alongside other sectors, with clear statements focused on the sustainabledevelopment.O programa do Álcool brasileiro é apontado como uma estratégia para o desenvolvimento sustentável, no entanto, seus impactos negativos podem minimizar os seus benefícios. Nos últimos dez anos, a área de cana de açúcar aumentou de 105 mil ha para mais de 700 mil ha no estado do Mato Grasso do Sul, entretanto, pouco se sabe sobre os impactos causados nesta região do Brasil. O objetivo desse trabalho foi fazer uma avaliação dos impactos da cana no sudeste deste estado por meio de entrevistas, análise de relatórios e visitas a campo. A maior proteção de Áreas Legalmente Protegidas e aumento no número de empresas formalmente cadastradas estão entre os fatores positivos encontrados. Quanto aos impactos negativos, sobressaem os conflitos com Territórios Indígenas e problemas relacionados à saúde pública nas cidades envolvidas analisadas. Os resultados apontam para a necessidade do poder público criar e coordenar ações junto aos diversos setores com diretrizes claras focadas no desenvolvimento sustentável

Technique for supine percutaneous nephrolithotomy

Percutaneous nephrolithotomy is the gold standard for large kidney stones. Supine approach has proved to be safe and effective. Herein we present an educational video about our stepwise technique of supine PCNL in a safe way