Search results for "LOAD"
showing 10 items of 1967 documents
Managing electrical energy storage systems and shiftable loads with an innovative approach in energy districts
2014
In this work, a power dispatch problem for a system composed of an aggregate of loads and an electrical energy storage system is considered. The approach to solve the optimal dispatch is innovative and shows good performances in limited calculation times. According to the more recent indications coming from the European distributors, the architecture for energy dispatch at distribution level will be hierarchical. The 'Aggregator' is the interface between groups of loads and the energy distributor and sends the individual consumers the desired load profiles, following which the user may gets a discount on the energy bill. On the other hand, the energy tariff may follow a given daily profile …
Real-time pricing for aggregates energy resources in the Italian energy market
2015
Abstract Over the last decade, the architecture of the energy market has radically changed. In many countries end-users are now able to directly access the market, which has given rise to the question of how they can actively participate in that market. End-users can comprise a critical mass through aggregation that is carried out by a third party – to wit the “loads aggregator.” This paper proposes a new framework for generating feasible real-time price curves for those end-users in a demand-response management process. The underlying algorithm generates output curves as the solution to a constrained optimization problem whose objective function is the aggregator's economic benefit. A case…
Muzeja pamatkrājuma elektroniskais katalogs
2019
Kvalifikācijas darbā ir izstrādāts Latvijas Universitātes muzeja pamatkrājuma elektroniskais katalogs. Sākotnēji, muzeja darbinieki muzeja eksponenta uzskaiti veidoja excel formātā, kur bija apkopoti dati par priekšmetu autoriem, izmēriem, topogrāfijas novietojumiem utt.. Tomēr šie dokumenti bija tikai redzami muzeja darbiniekiem, un nebija saskarsmes ar lietotāju. Tādēļ tika nolemts, ka nepieciešams datus konvertēt uz jaunu datubāzi, kurai tiek veidota lietotāju saskarsme caur Latvijas Universitāti. Pēc sistēmu ievades, lietotāji varēs apskatīt kuri priekšmeti un kurā vietā no katra muzeja kataloga ir izlikti kā eksponenti, savukārt muzeja darbinieki ir vienīgie kuri varēs rediģēt vai piev…
[pi]-strain-induced electrophilicity in small cycloalkynes: a dft analysis of the polar cycloaddition of cyclopentyne towards enol ethers
2006
Small cycloalkynes possess a π-strain-induced electrophilicity related to the bending of the C–Csp–Csp bond angle. For cyclopentyne and benzyne, the electrophilicity index defined in the context of density functional theory gives a coherent rationale for the reactivity of these cycloalkynes, which may act as electrophiles in polar cycloaddition reactions toward enol ethers. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
The transfer of tin and germanium atoms from N-heterocyclic stannylenes and germylenes to diazadienes.
2005
New N-heterocyclic stannylenes and germylenes were synthesized by transamination of E[N(SiMe3)2] (E = Ge, Sn) with alpha-amino-aldimines or ethylidene-1,2-diamines and were characterized by spectroscopic methods and in the case of the germylene 10 g by X-ray diffraction. The reactions of several germylenes and stannylenes with diazadienes were studied by using dynamic NMR and computational methods. Experimental and theoretical studies confirmed that metathesis with exchange of the Group 14 atom is feasible for both stannylenes and germylenes, with exchange rates being generally higher for stannylenes. The metathesis of the diazadiene 3 b and the stannylene 1 b follows second-order kinetics …
A DFT study of the ionic [2+2] cycloaddition reactions of keteniminium cations with terminal acetylenes
2015
Abstract The molecular mechanism of the ionic [2+2] cycloaddition (I-22CA) reactions of a keteniminium cation (KC) with acetylene and propyne has been investigated using DFT methods at the MPWB1K/6-311G(d,p) level. These I-22CA reactions take place via a two-step mechanism. The first step is the nucleophilic attack of these alkynes on the central carbon of KC, yielding cyclopropene intermediates, while the second step corresponds to the conversion of these intermediates into more stable cyclobuteniminium cations (CCs). The first step is the rate-determining step, while the second step is responsible for the formation of the two regioisomeric CCs experimentally observed in the reaction with …
1,3-Dipolar cycloaddition of 1H-pyrazinium-3-olate and N1- and C-methyl substituted pyrazinium-3-olates with methyl acrylate: a density functional th…
2011
Abstract A DFT study of the 1,3-dipolar cycloaddition of methyl acrylate to 1H-pyrazinium-3-olate and N1- and C-methyl substituted pyrazinium-3-olates, in the gas phase and in THF, has been carried out at the B3LYP/6-31G(d) level. Two stereoisomeric pathways, endo and exo, and two regioisomeric channels, 2-oxo-3,8-diazabicyclo[3.2.1]octane-6-ester and 7-ester products, have been considered. Thermodynamic and kinetic parameters calculated at room temperature have been analyzed. The regioselectivity has been interpreted using reactivity indices. It is generally found that the exo pathway is preferred and the formation of the 6-esters is dominant. The theoretical data obtained for the cycloadd…
Bis-1,2,4-triazolo[4,3-a:3′,4′-c]quinoxalines of pharmaceutical interest from 1,3-dipolar cycloaddition
2008
Abstract Various derivatives of the heterocyclic system 1,12,12a,12b-tetrahydrobis-1,2,4-triazolo[4,3-a:3′,4′-c]quinoxaline of pharmaceutical interest have been obtained by double site- and regio-selective 1,3-dipolar cycloaddition of arylnitrilimines to quinoxalines. No evidence for the formation of mono-adducts was obtained, at variance with literature reports. Specific studies to establish the exact stereochemistry of the bis-cycloadducts were undertaken.
Work characteristics in long-term temporary workers and temporary-to-permanent workers: A prospective study among Finnish health care personnel
2011
In this study, the authors seek to account for possible transitions from temporary to permanent employment in relation to perceived psychosocial work characteristics, i.e. job insecurity, workload, job control and organizational communication. The study compared three groups of Finnish hospital workers utilizing a two-wave design with a two-year time lag: (1) workers who were temporarily employed at Time 1 but permanently employed at Time 2 (temporary-to-permanent workers; n = 25); (2) workers who were temporarily employed at Time 1 and at Time 2 (long-term temporary workers; n = 45); and (3) a reference group of workers who were permanently employed at Time 1 and Time 2 (permanent workers…
Autonomy and Workload in Relation to Temporary and Permanent Workers’ Job Involvement
2010
The aim of the study was to investigate contract type (temporary vs. permanent employment) as a possible moderator in the relationship between autonomy and workload on the one hand, and job involvement on the other hand in samples from two countries: Belgium and Finland. The results on possible interactions were similar in the two countries. Contract type moderated the relationship between autonomy and job involvement: The relationship was stronger in permanent than in temporary workers. No moderation was found for workload. Instead, workload associated positively with job involvement in both temporary and permanent workers. These findings are discussed with reference to the activation hyp…