Search results for "Monitoring"
showing 10 items of 3614 documents
Un approccio semplificato per il calcolo del load flow nelle smart grids basato su misure distribuite in bassa tensione
2017
I sistemi di misura distribuiti sono alla base delle "smart distribution grids", ove la crescente presenza di generazione distribuita e sistemi di accumulo e la conseguente transizione verso sistemi attivi rendono necessarie funzionalità avanzate di monitoraggio, controllo e gestione delle reti. In tale contesto, un elemento essenziale è l'analisi dei flussi di potenza, che, com'è noto, può essere effettuata tramite algoritmi di load flow, noti il modello della rete e le potenze generate/assorbite nei vari nodi. Per la misura di tali grandezze sulla media tensione (MT), si possono utilizzare diversi strumenti (quali phasor measurement units, smart meters, power quality analyzers), che però …
Un metodo basato su misure distribuite in bassa tensione per il calcolo del load flow nelle smart grids
2016
Con la diffusione della generazione distribuita nei sistemi elettrici di distribuzione e la conseguente loro transizione verso reti attive, è diventato essenziale disporre di opportuni sistemi per il monitoraggio, il controllo e la gestione delle retistesse. In questo ambito, l'unità GMEE di Palermo, in collaborazione con l'ISSIA-CNR e la STMicroelectronics, da alcuni anni si occupa dello sviluppo di sistemi di misura e comunicazione per lo sviluppo delle "smart distribution grids". In particolare, per quanto riguarda il monitoraggio della rete, lo studio è stato focalizzato sull'analisi dei flussi di potenza, che, noti il modello della rete e le potenze generate o assorbite nei vari nodi, …
Concentrations, optical properties and sources of humic-like substances (HULIS) in fine particulate matter in Xi'an, Northwest China
2021
Humic-like substances (HULIS) are ubiquitous in the atmospheric environment, which affects both human health and climate. We present here the mass concentration and optical characteristics of HULIS isolated from aerosol samples collected in Xi'an, China. Both mass concentration and absorption coefficient (Abs365) of HULIS show clear seasonal differences, with the highest average in winter (3.91 μgC m-3 and 4.78 M m-1, respectively) and the lowest in summer (0.65 μgC m-3 and 0.55 M m-1, respectively). The sources of HULIS_C and light absorption of HULIS were analyzed by positive matrix factorization (PMF) and four major sources were resolved, including secondary formation, biomass burning, c…
Water-Insoluble Organics Dominate Brown Carbon in Wintertime Urban Aerosol of China: Chemical Characteristics and Optical Properties.
2020
The chromophores responsible for light absorption in atmospheric brown carbon (BrC) are not well characterized, which hinders our understanding of BrC chemistry, the links with optical properties, and accurate model representations of BrC to global climate and atmospheric oxidative capacity. In this study, the light absorption properties and chromophore composition of three BrC fractions of different polarities were characterized for urban aerosol collected in Xi'an and Beijing in winter 2013-2014. These three BrC fractions show large differences in light absorption and chromophore composition, but the chromophores responsible for light absorption are similar in Xi'an and Beijing. Water-ins…
Effective broadband refractive index retrieval by a white light optical particle counter.
2009
A new approach to retrieve the effective broadband refractive indices (nbroad,eff) of aerosol particles by a white light aerosol spectrometer (WELAS) optical particle counter (OPC) is presented. Using a tandem differential mobility analyzer (DMA)-OPC system, the nbroad,eff are obtained for both laboratory and field applications. This method was tested in the laboratory using substances with a wide range of optical properties. With the obtained nbroad,eff, WELAS aerosol size distributions can be corrected. Therefore, this method can be used for instrument calibration in both laboratory and field measurements. The retrieved effective broadband refractive indices for the scattering aerosols we…
New Challenges for Sustainable Organizations in Light of Agenda 2030 for Sustainability
2021
Sustainability is one of humanity’s most daunting issues at present. Increasing popula- tion, escalation of anthropogenic activities, industrialization, modern agricultural practices that pollute water, air, and soil around the world, and ever-increasing greenhouse gas emissions mean that sustainability is now in doubt [1]. In response to these critical concerns, the world has come up with several initiatives including Agenda 2030. Agenda 2030 is a commitment to eradicate poverty and achieve sustainable development worldwide, ensuring that no one is left behind by 2030. Its adoption was a landmark achievement, providing a shared vision towards sustainable development for all. Its 17 Sustain…
Reply to Castellano and David: Long-term fate of nitrate fertilizer and nitrate from agricultural catchments
2014
We thank Castellano and David for their insightful comments (1) on our paper (2), in which they point out that short-term changes in land use and agricultural management can lead to rapid reductions in nitrate leaching from agricultural systems. We fully agree with Castellano and David that in diversified cropping systems, this N distribution may be different, potentially resulting in reduced nitrate leaching.
Corrigendum to “Conservation value of forest plantations for bird communities in western Kenya” [Forest Ecol. Manag. 255 (2008) 3885–3892]
2009
A re-analysis of the bird data revealed a mistake within the database query. Only bird individuals that were heard were integrated in the results leading to lower total richness and number of individuals. In total 115 species and 13,331 individuals were detected of which 41 were forest specialists (43% of all individuals), 40 forest generalists (41%) and 34 forest visitors (16%). The statistical analyses remain very similar. We recorded significant differences in mean bird species richness, number of individuals and relative species richness among the five forest types (Table 1). Multiple pairwise comparisons showed significantly higher numbers of species in natural forest, mixed indigenous…
Researches Regarding the Species Diabrotica Virgifera Virgifera Le Conte in Sibiu County
2010
From the very beginning of the recording of its appearance in Europe as well as in
 our country the published material emphasized the harmful potential of the pest Diabrotica virgifera
 virgifera also drawing the attention to the scientific world and to the farmers as well upon this factor
 of reduction of the production of corn.
 In Sibiu County this species was first recorded in 2001, coming from West, at the border with
 Alba County. The first gatherings were done in Miercurea Sibiului. The investigation was done during
 2001–2009 concerning in: monitoring the adults and the larvae, the identification of the attacked
 plants, the way of harming both for…
Studies on Using Sugar Beet for Bio-Ethanol for Vehicle Motors
2011
The paper presents some researches on using sugar beet for producing bio-ethanol, considering the advantages which this raw material presents compared to other materials from which bio-ethanol can be obtained. One of the reasons of using bio-ethanol for motors as a fuel is the goal to reduce of 20% of greenhouse gases and it is established that the emissions of CO2 are much reduced in the case of bio-ethanol than that of conventional fuels.