Search results for "Tie line"
showing 6 items of 6 documents
Computation of Unstable Binodals Not Requiring Concentration Derivatives of the Gibbs Energy
1998
The equilibrium of three liquid phases in a binary mixture implies the existence of tie lines and binodals that are different from the normal experimentally observable ones. First of all, there are the metastable extensions of the binodal built up by S/S tie lines. These S/S tie lines fulfill the equilibrium condition of the minimum of the Gibbs energy of the entire two-phase system. Both coexisting phases are located within the meta(stable) region. There are two additional types of tie lines: U/U (maximum of the Gibbs energy; both end points within the unstable area) and U/S tie lines (saddle point; one end point within the (meta)stable, the other within the unstable region). All types of…
Optimized design of wide-area PSS for damping of inter-area oscillations
2015
In this paper a genetic algorithm based wide area power system stabilizer (PSS) in a multi machine power system for damping of low frequency inter-area oscillations has been presented. The wide area PSS is composed of two stages, the input of one stage is a local signal and the input of other is a global signal. Geometric measure of controllability and observability is used to select the most effective stabilizing signals and location of controller. Tie line active power flow deviation is found to be the most effective input signal. Time domain based objective function is minimized, in which the deviation in the oscillatory rotor speed of generator is involved so that the stability performa…
Specific features of the interfacial tension in the case of phase separated solutions of random copolymers
2000
Abstract Phase diagrams (cloud point curves, critical points, tie lines for constant critical composition) and interfacial tensions as a function of temperature were measured for solutions of two random copolymers: poly(dimethylsiloxane- ran -methylphenylsiloxane) [I] and poly(styrene- ran -acrylonitrile) [II]. Acetone and anisole served as solvents for I and toluene for II; all solutions exhibit UCSTs between 300 and 310 K. The phase separation behavior can be well modeled if one accounts for the molecular and chemical non-uniformities of the random copolymers used in this study. The interfacial tensions σ differ most markedly from that of comparable homopolymer solutions in their correlat…
Transitions from grid-connected to island operation of Smart Microgrids
2019
In this paper a control methodology is presented to perform a bumpless transition from the on-grid to the offgrid of a smart microgrid. The derived controller manages the internal production in order to get to zero the tie-line active and reactive power flows so that the opening of the tie line breaker does not produce significant perturbations. Experimental tests performed on the microgrid built at the Polytechnic University of Bari demonstrated the effectiveness of the proposed control strategy.
Interfacial tension between polymer-containing liquids - Predictability and influences of additives
1999
The first part of the contribution deals with the interfacial tension, σ, of phase-separated polymer solutions in single or mixed solvents and of binary polymer blends as a function of the relative distance to the critical temperature of the system, special attention being paid to the possibilities of theoretical prediction. Two methods are discussed in more detail. One is based on a realistic description of the Gibbs energy of mixing as a function of composition, the second correlates σ with the length of the measured tie line. The second part is devoted to another aspect, namely the effects of additives on the interfacial tension between the coexisting phases of demixed polymer solutions …
Vispārinātie lineārie modeļi skaita tipa datu analīzei
2022
Bakalaura darbs ir veltīts vispārināto lineāro modeļu, kas piemēroti skaita tipa datu analīzei, teorijas apskatam. Darbā apskatīts Puasona regresijas modelis, kā arī modeļi, kas piemēroti pārāk lielas dispersijas gadījumā (kvazi-Puasona un negatīvā binomiālā sadalījuma regresijas modeļi). Skaita tipa datos var būt situācijas, kad liels datu daudzums ir 0, tāpēc šādu datu analīzei aprakstīti īpaši piemēroti modeļi, jo iepriekšminētie modeļi šādiem datiem nevar sniegt korektus novērtējumus. Atsevišķi tika aprakstīta arī empīriskās ticamības funkcijas metode vispārināto lineāro modeļu koeficientu novērtēšanai un ticamības intervālu konstruēšanai, kuru var izmantot Puasona modeļa gadījumā. Darb…