102,454 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
The reasonable consumer under the European and Italian regulation on unfair business-to-consumer commercial practices
No full textIl contributo analizza il significato dell'attributo della ragionevolezza riferito al consumatore dalla disciplina comunitaria delle pratiche commerciali sleal
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
[Value of electromyography for the detection of peripheral neuropathies in the course of chronic hepatopathies].
No full textIt has recently been noted that peripheral nerve fibres are involved in the course of chronic liver disease. The existence of hepatic polyneuropathy is still a matter of debate. A series of 29 subjects (not including diabetics or alcoholics) were examined clinically and electromyographically. Signs of distal lower extremity polyneuritis (paresthesia, hypoesthesia and osteotendinous hypo-areflexia) were noted in 31%. Latent neuropathy was observed in the form of slow maximum and minimum motor conduction rates in clinically unimpaired nerves. Electromyographical alterations were more evident in subjects with frankly chronic as opposed to barely chronic liver disease
Enhanced gas sensing properties of chemiresistors based on ZnO nanorods electrodecorated with Au and Pd nanoparticles
No full textColloidal Au and Pd nanoparticles (NPs) were directly electrochemically synthesized, by sacrificial anode electrolysis (SAE), on hydrothermal ZnO nanostructures, previously desiccated; further, the functionalized ZnO nanostructures were subjected to thermal annealing at 550°C to obtain stable ZnO nanorods (NRs), superficially decorated by naked metal NPs. The both pristine and metal functionalized ZnO NRs were proposed as active layer in chemiresistive sensors for environmental monitoring to detect pollutant gases (e.g. NO2, C4H10). The effect of the presence and of the chemical nature of the deposited metal NPs on the performance of ZnO NRs-based gas sensor (e.g. sensitivity, selectivity and recovery) was evaluated, comparing the sensing results with those of pristine ZnO NRs. In particular, the gas sensing properties of pristine and metal-functionalized ZnO NRs were studied at an operating temperature of 300°C towards a various range of concentration of different gaseous pollutants. © 2017 Materials Research Society
Sensitive detection of hydrocarbon gases using electrochemically Pd-modified ZnO chemiresistors
No full textPristine and electrochemically Pd-modified ZnO nanorods (ZnO NRs) were proposed as active sensing layers in chemiresistive gas sensors for hydrocarbon (HC) gas detection (e.g., CH4, C3H8, C4H10). The presence of Pd nanoparticles (NPs) on the surface of ZnO NRs, obtained after the thermal treatment at 550 °C, was revealed by morphological and surface chemical analyses, using scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. The effect of the Pd catalyst on the performance of the ZnO-based gas sensor was evaluated by comparing the sensing results with those of pristine ZnO NRs, at an operating temperature of 300 °C and for various HC gas concentrations in the range of 30-1000 ppm. The Pd-modified ZnO NRs showed a higher selectivity and sensitivity compared to pristine ZnO NRs. The mean sensitivity of Pd-modified ZnO NRs towards the analyzed HCs gases increased with the length of the hydrocarbon chain of the target gas molecule. Finally, the evaluation of the selectivity revealed that the presence or the absence of metal nanoparticles on ZnO NRs improves the selectivity in the detection of specific HCs gaseous molecules. © 2017 Dilonardo et al
Sensing properties of MWCNTs layers electrodecorated with metal nanoparticles for detection of aromatic hydrocarbon compounds
No full textAn electrophoretic process is proposed to deposit electrochemically-preformed Au or Pd NPs, with controlled size, directly on MWCNTs-based chemiresistors to improve the detection of aromatic pollutants, compared to pristine ones. The sensing properties of pristine and functionalized MWCNTs were evaluated at an operating temperature of 40°C towards various concentrations of one aromatic pollutant, belonging to the dangerous BTEX class of compounds, m-Xylene. The sensing performance was related to the metal used in the functionalization process. Metal-doped MWCNTs sensors exhibited a very high gas sensitivity to m-Xylene even at low (80 ppb) concentration at low operating temperature (40°C), good reversibility and repeatability, with the sensing properties controlled by the type of deposited metal catalyst. The results indicate that Metal-modified MWCNT-based chemiresistive gas sensors has good potential in practical applications, due to its remarkable performance, low power consumption, and facile synthesized methods. © 2017 Materials Research Society
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