427 research outputs found
A Methodology for Pumping Control Based on Time Variable Trigger Levels
No full textAbstractA methodology for the control of a pumping plant feeding a tank is presented. This methodology is aimed at minimizing the energy costs by maximizing pumping during off-peak electricity tariff periods. It is based on trigger levels which are variable during the day according to a prefixed pattern in order to ensure that the water level in the elevated tank is at its minimum and maximum values at the end of the peak and off-peak tariff periods respectively. The pattern of the trigger levels is defined by solving a multi-objective problem aimed at minimizing the energy costs and the number of pump switches.The methodology was applied to the real case of a pumping plant feeding an elevated tank for daily balance which, in turn, feeds a small town in northern Italy; one week of hourly observed total consumptions was considered. This methodology was compared with other two methodologies typically used for pump control, i.e. pump scheduling and fixed trigger levels. The results show that the proposed methodology allows for achieving energy costs that are definitively lower than those obtainable by using fixed trigger levels, and comparable with those obtainable by using pump scheduling, being the number of pump switches the same. On the other hand, unlike the pump scheduling, the methodology presented does not require any water demand forecast and scheduling optimization to be repeated daily, thus representing an effective and efficient tool for pumping plant operation
Tavole n. 81-117 e 130-131
No full textIl contributo consiste in una serie di tavole grafiche di rilievo, lettura critica del costruito e analisi metrologica di Palazzo Alberini a Rom
Agricoltura, alimentazione, ambiente: come mantenere la "tripla A" al tempo della crisi?
No full textThe increasing food demand leads to an increase of the world food production. Nevertheless, there is the fear that neither yield increases nor exploitation of new croplands will be able to cope with this need. The ongoing changes will decrease the agricultural productivity of some areas (the Mediterranean among these), due to a lower soil fertility and water availability, whereas others will get an advantage, mainly in the north. On the other hand, the demand for meat is still rising, thanks to better living conditions in emerging countries. However, meat production, particularly livestock, has an important impact on climate as well as on the environment. Moreover, “energy crops” not only help questionably to reduce greenhouse gas emissions, but they have already shown a negative impact on prices of food cereals. With this background, a new version of “Decide” game has been created on the theme of sustainable agriculture, emphasizing the topic of resource consumption and greenhouse gas emissions
Live-cell analysis of human cytomegalovirus dna polymerase holoenzyme assembly by resonance energy transfer methods
No full textHuman cytomegalovirus (HCMV) genome replication is a complex and still not completely understood process mediated by the highly coordinated interaction of host and viral products. Among the latter, six different proteins form the viral replication complex: a single-stranded DNA binding protein, a trimeric primase/helicase complex and a two subunit DNA polymerase holoenzyme, which in turn contains a catalytic subunit, pUL54, and a dimeric processivity factor ppUL44. Being absolutely required for viral replication and representing potential therapeutic targets, both the ppUL44–pUL54 interaction and ppUL44 homodimerization have been largely characterized from structural, functional and biochemical points of view. We applied fluorescence and bioluminescence resonance energy transfer (FRET and BRET) assays to investigate such processes in living cells. Both interactions occur with similar affinities and can take place both in the nucleus and in the cytoplasm. Importantly, single amino acid substitutions in different ppUL44 domains selectively affect its dimerization or ability to interact with pUL54. Intriguingly, substitutions preventing DNA binding of ppUL44 influence the BRETmax of protein–protein interactions, implying that binding to dsDNA induces conformational changes both in the ppUL44 homodimer and in the DNA polymerase holoenzyme. We also compared transiently and stably ppUL44-expressing cells in BRET inhibition assays. Transient expression of the BRET donor allowed inhibition of both ppUL44 dimerization and formation of the DNA polymerase holoenzyme, upon overexpression of FLAG-tagged ppUL44 as a competitor. Our approach could be useful both to monitor the dynamics of assembly of the HCMV DNA polymerase holoenzyme and for antiviral drug discovery
Weaning from mechanical ventilation
No full textABSTRACT
Weaning from mechanical ventilation could be defined as the gradual process of transferring the respiratory work of breathing from the ventilator to the patients. The primary goal of weaning is timeliness, which implies that weaning should be started neither too late nor too early. Discontinuation of mechanical ventilation and removal of artificial airway are easily obtained in the majority of patients since about 70-80% of the patients are extubated when routine clinical criteria are fulfilled. This, however, is not always the case. In fact, about 20-30% of the patients present a difficult weaning. Patients require mechanical ventilation support when the ventilatory and/or gas exchange capabilities of their respiratory system fail. This respiratory failure can be the results of impairment between the load imposed on the respiratory system and the capacity of the respiratory muscle to perform this increased work of breathing. Shortly, the factors that limit the weaning process can be summarized as follows: 1) oxygenation, 2) respiratory load (table 1) and capacity of the respiratory muscle to accomplish this load, 3) cardiovascular performance, 4) psychological factors. To quantify these factors a great number of weaning indices has been proposed. However, none has been demonstrated to able to predict the weaning success, apart in patients with chronic obstructive pulmonary disease. Furthermore, the probability of remaining under mechanical ventilation is statistically higher in patients undergoing uncontrolled clinical practice when compared to a fixed protocol previously agreed
Hepatitis C virus and host cell lipids: An intimate connection?
No full textHepatitis C virus (HCV) is a major human pathogen, persistently infecting more than 170 million individuals worldwide. The recent establishment of fully permissive culture systems allowed unraveling the close link between host cell lipids and HCV, at each step of the viral replication cycle. HCV entry is triggered by the timely coordinated interaction of virus particles with cell surface receptors, including the low-density lipoprotein receptor. Viral RNA replication strictly depends on fatty acids and cholesterol biosynthesis. This process occurs on modified intracellular membranes, forming a membranous web. Their biogenesis is induced by the viral nonstructural proteins (NS) 4B and NS5A and requires the activity of cellular lipid kinases belonging to the phosphatidylinositol-4-kinase III family. A hallmark of HCV-induced membranes is thus the presence of phosphatidylinositol-4-phosphate (PI4P), which is synthesized by these kinases. Intriguingly, certain recently identified HCV dependency factors selectively bind to PI derivatives, suggesting a crucial role for PIPs in viral RNA replication and assembly. The latter occurs on the surface of lipid droplets and is tightly connected to the very low density lipoprotein pathway leading to the formation of unique lipoviro particles. Thus, HCV exploits lipid metabolism in many ways and may therefore serve as a model system to gain insights into membrane biogenesis, lipid droplet formation and lipid trafficking
La tutela del consumatore. Principio di verità e aspetti particolari della comunicazione commerciale
No full textAnalisi delle disposizioni contenute nel Codice di Autodisciplina della Comunicazione Com-merciale che specificano il divieto generale di ingannevolezza, con riferimento ad alcuni aspetti specifici e ad ambiti che presentano problemi particolari di tutela del consumatore i campi "sensibili"(come il consumo di alcol o l'uso di farmaci o prodotti cosmetici, l'uso di integratori alimentari). Il commento delle disposizioni è accompagnato da un'analisi della giurisprudenza del Giurì di autodisciplina
La tutela dell'impresa
No full textIl capitolo analizza le norme del Codice di autodisciplina della comunicazione commerciale e la giurisprudenza del Giurì che sono poste a tutela dell'impresa (imitazione della pubblicità, denigrazione del concorrente e disciplina della pubblicità comparativa)
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