AliReza Abbasi | Qom University of Technology (original) (raw)

Papers by AliReza Abbasi

Reactive power dispatch in power systems is a complex combinatorial optimization problem involvin... more Reactive power dispatch in power systems is a complex combinatorial optimization problem involving nonlinear functions with multiple local minima and nonlinear constraints. In an open electricity market reactive power support is an ancillary service for real power transportation. From the viewpoint of ISO, this paper provides a dispatching reactive power model, based on optimal power flow, by which both the cost of procuring reactive power as auxiliary service and the losses of active power are minimized. In this paper the cost of reactive power support consists of two components: reactive power cost of generators and shunt capacitors. In addition an extremely powerful differential evolution optimization approach based on multiagent systems (MADE) is presented, and applied to the reactive power optimization problem in electricity markets. In the proposed method, agents live in a lattice-like environment and each agent competes with its neighbors, and also learns by using its own knowledge. MADE uses these agent-agent interactions and the evolutionary mechanism of DE to obtain the global optimum. The effectiveness of the proposed method is then verified using the IEEE 30-bus system, and its performance is compared to other stochastic search approaches.

Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organi... more Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organisms. In most higher plants, aand g-tocopherol are predominant with their ratio being under spatial and temporal control. While a-tocopherol accumulates predominantly in photosynthetic tissue, seeds are rich in g-tocopherol. To date, little is known about the specific roles of aand g-tocopherol in different plant tissues. To study the impact of tocopherol composition and content on stress tolerance, transgenic tobacco (Nicotiana tabacum) plants constitutively silenced for homogentisate phytyltransferase (HPT) and g-tocopherol methyltransferase (g-TMT) activity were created. Silencing of HPT lead to an up to 98% reduction of total tocopherol accumulation compared to wild type. Knockdown of g-TMT resulted in an up to 95% reduction of a-tocopherol in leaves of the transgenics, which was almost quantitatively compensated for by an increase in g-tocopherol. The response of HPT and g-TMT transgenics to salt and sorbitol stress and methyl viologen treatments in comparison to wild type was studied. Each stress condition imposes oxidative stress along with additional challenges like perturbing ion homeostasis, desiccation, or disturbing photochemistry, respectively. Decreased total tocopherol content increased the sensitivity of HPT:RNAi transgenics toward all tested stress conditions, whereas g-TMT-silenced plants showed an improved performance when challenged with sorbitol or methyl viologen. However, salt tolerance of g-TMT transgenics was strongly decreased. Membrane damage in g-TMT transgenic plants was reduced after sorbitol and methyl viologen-mediated stress, as evident by less lipid peroxidation and/or electrolyte leakage. Therefore, our results suggest specific roles for aand g-tocopherol in vivo.

Integration of regulating power markets of different balancing regions has a potential to reduce ... more Integration of regulating power markets of different balancing regions has a potential to reduce the costs of balancing within multinational power markets by exchange of regulating power between these regions. Currently, most regulating power markets are operating on a national level so that exchange of regulating power between regions is minimal. This paper investigates the potentials for reduction of total balancing costs by creation of multinational regulating power markets studying the case study of Northern Europe; the Netherlands, the Nordic region and Germany. An optimization model is built to analyze the effects on total balancing costs - the costs paid by a multinational TSO to the providers of regulating power. Based on the numerical results, total balancing costs can decrease by 100 million Euros per year when enough interconnection capacity is allocated to balancing trade. Furthermore, total amount of activated regulating power is reduced due to supportive power exchange. Finally, the use of the uniform pricing mechanism leads to frequent congestion of interconnection lines due to balancing trade. On average, regulation power prices stay within the same range.

The optimal reactive power dispatch (ORPD) problem is formulated as a combinatorial optimization ... more The optimal reactive power dispatch (ORPD) problem is formulated as a combinatorial optimization problem involving nonlinear objective function with multiple local minima. In this paper, as a new approach, different ant colony optimization (ACO) algorithms are applied to the reactive power dispatch problem. Ant system (AS), the firstly introduced ant colony optimization algorithm, and its direct successors, elitist ant system (EAS), rank-based ant system (ASrank) and max-min ant system (MMAS), are employed to solve the reactive power dispatch problem. To analyze the efficiency and effectiveness of these modern search algorithms, the proposed methods are applied to the IEEE 30-bus system and the results are compared to those of conventional mathematical methods, genetic algorithm, evolutionary programming, and particle swarm optimization.

Electric Power Components and Systems, 2009

Abstract This article investigates the effect of a few types of ferroresonance suppression circui... more Abstract This article investigates the effect of a few types of ferroresonance suppression circuits on suppression of the phenomenon of ferroresonance in coupling capacitor voltage transformers. A novel technique is proposed for damping of dangerous overvoltages due ...

Scientometrics, 2010

Although there are many studies for quantifying the academic performance of researchers, such as ... more Although there are many studies for quantifying the academic performance of researchers, such as measuring the scientific performance based on the number of publications, there are no studies about quantifying the collaboration activities of researchers. This study addresses this shortcoming. Based on three measures, namely the collaboration network structure of researchers, the number of collaborations with other researchers, and the productivity index of co-authors, two new indices, the RC-Index and CC-Index, are proposed for quantifying the collaboration activities of researchers and scientific communities. After applying these indices on a data set generated from publication lists of five schools of information systems, this study concludes with a discussion of the shortcomings and advantages of these indices.

1 a.abbasy@tudelft.nl 2 r.a.vanderveen@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-Different cr... more 1 a.abbasy@tudelft.nl 2 r.a.vanderveen@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-Different cross-border arrangements for exchange of balancing services in electricity markets can potentially have different effects on the behavior of market parties and consequently market performance as a whole. This paper focuses on BSP-TSO trading (foreign bidding) as one of the main four arrangements proposed for exchange of balancing services across borders. We analyze the case of Norway and the Netherlands as a main balancing market integration case in Northern Europe and investigate the possible effect of enabling BSP-TSO trading (as one step towards full balancing market integration) between these countries on the performance of the two individual markets. An agent-based model is developed in MATLAB through which we study the possible change in behavior of market parties as a result of BSP-TSO trading implementation.

Synthetic Communications, 2008

... 2003, 44, 4927; (b) Lam, PYS; Vincent, G.; Bonne D.; Clark, CG; Deudon, S.; Jadhav, PK ... b)... more ... 2003, 44, 4927; (b) Lam, PYS; Vincent, G.; Bonne D.; Clark, CG; Deudon, S.; Jadhav, PK ... b) Nair, V.; Rajesh, C.; Vinod, AU; Bindu, S.; Sreekanth, AR; Mathen, JS; Balagopal, L. Strategies ... 5, 4273; (b) Nair, V.; Sreekanth, AR; Abhilash, N.; Biju, AT; Remadevi, B.; Menon, RS; Rath ...

1 r.a.c.vanderveen@tudelft.nl 2 a.abbasy@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-This paper... more 1 r.a.c.vanderveen@tudelft.nl 2 a.abbasy@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-This paper presents an agent-based analysis of the impact of different cross-border balancing arrangements on balancing market performance for the case of Northern Europe, i.e. the Netherlands, Germany and the Nordic region, taking into account the change in behaviour of Balance Responsible Parties (BRPs). The four compared arrangements are separate markets, Area Control Error (ACE) netting, balancing energy trading, and a common merit order list. It is found that ACE netting reduces the total Dutch imbalance costs by 25%, but that the more advanced arrangements have the potential to reduce those costs for the Netherlands and Germany by as much as 50%. However, in case of the common merit order list the imbalance risks for Nordic BRPs increase largely because of the regional marginal pricing, and the system balance states of Germany and the Nordic region are largely affected due to changes in BRP behaviour. The large imbalance costs reductions in Germany and the Netherlands are the result of the import of more than half of the balancing energy from the Nordic region, which is possible because of the high availability of cross-border capacity between the areas.

Dalton Transactions, 2004

Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetr... more Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) angstroms. EXAFS spectra yield a mean Sc-O bond distance of 2.09(1) angstroms for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been recorded, also of the deuterated compound, and analysed by means of normal coordinate methods, together with spectra of dimethyl sulfoxide. The effects on the vibrational spectra of the weak intermolecular C-H...O interactions and of the dipole-dipole interactions in liquid dimethyl sulfoxide have been evaluated, in particular for the S-O stretching mode. The strong Raman band at 1043.6 cm(-1) and the intense IR absorption at 1062.6 cm(-1) have been assigned as the S-O stretching frequencies of the dominating species in liquid dimethyl sulfoxide, evaluated as centrosymmetric dimers with antiparallel polar S-O groups. The shifts of vibrational frequencies and force constants for coordinated dimethyl sulfoxide ligands in hexasolvated trivalent metal ion complexes are discussed. Hexasolvated scandium(iii) ions are found in dimethyl sulfoxide solution and in [Sc(OSMe(2))(6)]I(3). The iodide ion-dipole attraction shifts the methyl group C-H stretching frequency for (S-)C-H...I(-) more than for the intermolecular (S-)C-H...O interactions in liquid dimethyl sulfoxide.

Acta Crystallographica Section E-structure Reports Online, 2006

Inorganic Chemistry, 2007

The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysp... more The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III), and lutetium(III) iodides crystallize in the monoclinic space group P21/n (No. 14) with Z = 4, while the octakis(DMSO) iodides of the larger lanthanum(III), cerium(III), and praseodymium(III) ions crystallize in the orthorhombic space group Pbca (No. 61), Z = 8. In all [Ln(OS(Me2)8]I3 compounds the lanthanoid(III) ions coordinate eight DMSO oxygen atoms in a distorted square antiprism. Up to three of the DMSO ligands were found to be disordered and were described by two alternative configurations related by a twist around the metal-oxygen (Ln-O) bond. To resolve the atomic positions and achieve reliable Ln-O bond distances, complete semirigid DMSO molecules with restrained geometry and partial occupancy were refined for the alternative sites. This disorder model was also applied on previously collected data for the monoclinic octakis(DMSO)yttrium(III) iodide. At ambient temperature, the eight Ln-O bond distances are distributed over a range of about 0.1 A. The average value increases from Ln-O 2.30, 2.34, 2.34, 2.36, 2.38, 2.40 to 2.43 A (Ln = Lu, Er, Y, Dy, Gd, Sm, and Nd) for the monoclinic [Ln(OSMe2)8]I3 structures, and from 2.44, 2.47 to 2.49 A (Ln = Pr, Ce, and La) for the orthorhombic structures, respectively. The average of the La-O and Nd-O bond distances remained unchanged at 100 K, 2.49 and 2.43 A, respectively. Despite longer bond distances and larger Ln-O-S angles, the cell volumes are smaller for the orthorhombic structures (Ln = Pr, Ce, and La) than for the monoclinic structure with Ln = Nd, showing a more efficient packing arrangement. Raman and IR absorption spectra for the [Ln(OS(CH3)2)8]I3 (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Er, Lu, and Y) compounds, also deuterated for La and Y, have been recorded and analyzed by means of normal coordinate methods. The force constants for the Ln-O and S-O stretching modes in the complexes increase with decreasing Ln-O bond distance and show increasing polarization of the bonds for the smaller and heavier lanthanoid(III) ions.

Inorganic Chemistry, 2007

Octakis(DMSO)lanthanoid(III) iodides (DMSO ) dimethylsulfoxide), [Ln(OS(CH 3 ) 2 ) 8 ]I 3 , of mo... more Octakis(DMSO)lanthanoid(III) iodides (DMSO ) dimethylsulfoxide), [Ln(OS(CH 3 ) 2 ) 8 ]I 3 , of most lanthanoid(III) ions in the series from La to Lu have been studied in the solid state and in DMSO solution by extended X-ray absorption fine structure (EXAFS) spectroscopy. L 3 -edge and also some K-edge spectra were recorded, which provided mean Ln−O bond distances for the octakis(DMSO)lanthanoid(III) complexes. The agreement with the average of the Ln−O bond distances obtained in a separate study by X-ray crystallography was quite satisfactory. The crystalline octakis(DMSO)lanthanoid(III) iodide salts have a fairly broad distribution of Ln−O bond distances, ca. 0.1 Å, with a few disordered DMSO ligands. Their EXAFS spectra are in excellent agreement with those obtained for the solvated lanthanoid(III) ions in DMSO solution, both of which show slightly asymmetric distributions of the Ln−O bond distances. Hence, all lanthanoid(III) ions are present as octakis(DMSO)lanthanoid(III) complexes in DMSO solution, with the mean Ln−O distances centered at 2. This decrease in the Ln−O bond distances is larger than expected from the previously established ionic radii for octa-coordination. This indicates increasing polarization of the Ln III −O(DMSO) bonds with increasing atomic number. However, the S(1s) electron transition energies in the sulfur K-edge X-ray absorption near-edge structure (XANES) spectra, probing the unoccupied molecular orbitals of lowest energy of the DMSO ligands for the [Ln(OS(CH 3 ) 2 ) 8 ] 3+ complexes, change only insignificantly from Ln ) La to Lu. This indicates that there is no appreciable change in the σ-contribution to the S−O bond, probably due to a corresponding increase in the contribution from the sulfur lone pair to the bonding. (1) Abbasi, A.; Lindqvist-Reis, P.; Eriksson, L.; Sandström, D.; Lidin, S.; Persson, I.; Sandström, M. Chem. Eur.

Acta Crystallographica Section E-structure Reports Online, 2006

In the title compound, trans-[RuCl2 (C2H6S) 4], the RuII ion, located on a special position (4a) ... more In the title compound, trans-[RuCl2 (C2H6S) 4], the RuII ion, located on a special position (4a) with crystallographically imposed symmetry, coordinates four S atoms from the dimethyl sulfide molecules and two chloride ions in an octahedral trans configuration. All atoms, ...

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2005

Infrared (IR), far-infrared (far-IR) and Raman spectra have been recorded of the hydrated lanthan... more Infrared (IR), far-infrared (far-IR) and Raman spectra have been recorded of the hydrated lanthanide(III) trifluoromethanesulfonates, [Ln(OH2)9](CF3SO3)3, (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), and also for the deuterated [La(OD2)9](CF3SO3)3 compound. This has enabled complete assignments of all seven metal-oxygen stretching modes for the first time. Force constant calculations have been performed for an LnO9(3+) moiety, with a tricapped trigonal prismatic oxygen atom arrangement in D3h point group symmetry. The lanthanide contraction in reflected in continuously increasing trends for the averaged LnO stretching frequencies and force constants with increasing inverse of ionic radii. The stretching force constants increased from 0.81 to 1.16 Ncm-1 for the LnO6 prism in the series from La to Lu, while those for the capping LnO3 bonds increased from 0.49 to 0.65 Ncm-1. The LnO stretching force constants showed a smooth correlation with the LnO bond distances to the prism oxygen atoms, while the correlation to the LnO capping oxygen atoms has a different shape, reflecting the increased ligand-ligand repulsion with decreasing lanthanide ion size.

Chemistry-a European Journal, 2005

Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped t... more Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in a large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for the smallest metal ions in the isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)n](CF3SO3)3, in which M=ScIII, LuIII, YbIII, TmIII or ErIII. The hydration number n increases (n=8.0(1), 8.4(1), 8.7(1), 8.8(1) and 8.96(5), respectively) with increasing ionic size. Deuterium (2H) solid-state NMR spectroscopy revealed fast positional exchange between the coordinated capping and prism water molecules; this exchange started at temperatures higher than about 280 K for lutetium(III) and below 268 K for scandium(III). Similar positional exchange for the fully nonahydrated yttrium(III) and lanthanum(III) compounds started at higher temperatures, over about 330 and 360 K, respectively. An exchange mechanism is proposed that can exchange equatorial and capping water molecules within the restrictions of the crystal lattice, even for fully hydrated lanthanoid(III) ions. Phase transitions occurred for all the water-deficient compounds at ≈185 K. The hydrated scandium(III) trifluoromethanesulfonate transforms reversibly (ΔH°=−0.80(1) kJ mol−1 on cooling) to a trigonal unit cell that is almost nine times larger, with the scandium ion surrounded by seven fully occupied and two partly occupied oxygen atom positions in a distorted capped trigonal prism. The hydrogen bonding to the trifluoromethanesulfonate anions stabilises the trigonal prism of water ligands, even for the crowded hydration sphere of the smallest metal ions in the series. Implications for the Lewis acid catalytic activity of the hydrated scandium(III) and lanthanoid(III) trifluoromethanesulfonates for organic syntheses performed in aqueous media are discussed.

Reactive power dispatch in power systems is a complex combinatorial optimization problem involvin... more Reactive power dispatch in power systems is a complex combinatorial optimization problem involving nonlinear functions with multiple local minima and nonlinear constraints. In an open electricity market reactive power support is an ancillary service for real power transportation. From the viewpoint of ISO, this paper provides a dispatching reactive power model, based on optimal power flow, by which both the cost of procuring reactive power as auxiliary service and the losses of active power are minimized. In this paper the cost of reactive power support consists of two components: reactive power cost of generators and shunt capacitors. In addition an extremely powerful differential evolution optimization approach based on multiagent systems (MADE) is presented, and applied to the reactive power optimization problem in electricity markets. In the proposed method, agents live in a lattice-like environment and each agent competes with its neighbors, and also learns by using its own knowledge. MADE uses these agent-agent interactions and the evolutionary mechanism of DE to obtain the global optimum. The effectiveness of the proposed method is then verified using the IEEE 30-bus system, and its performance is compared to other stochastic search approaches.

Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organi... more Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organisms. In most higher plants, aand g-tocopherol are predominant with their ratio being under spatial and temporal control. While a-tocopherol accumulates predominantly in photosynthetic tissue, seeds are rich in g-tocopherol. To date, little is known about the specific roles of aand g-tocopherol in different plant tissues. To study the impact of tocopherol composition and content on stress tolerance, transgenic tobacco (Nicotiana tabacum) plants constitutively silenced for homogentisate phytyltransferase (HPT) and g-tocopherol methyltransferase (g-TMT) activity were created. Silencing of HPT lead to an up to 98% reduction of total tocopherol accumulation compared to wild type. Knockdown of g-TMT resulted in an up to 95% reduction of a-tocopherol in leaves of the transgenics, which was almost quantitatively compensated for by an increase in g-tocopherol. The response of HPT and g-TMT transgenics to salt and sorbitol stress and methyl viologen treatments in comparison to wild type was studied. Each stress condition imposes oxidative stress along with additional challenges like perturbing ion homeostasis, desiccation, or disturbing photochemistry, respectively. Decreased total tocopherol content increased the sensitivity of HPT:RNAi transgenics toward all tested stress conditions, whereas g-TMT-silenced plants showed an improved performance when challenged with sorbitol or methyl viologen. However, salt tolerance of g-TMT transgenics was strongly decreased. Membrane damage in g-TMT transgenic plants was reduced after sorbitol and methyl viologen-mediated stress, as evident by less lipid peroxidation and/or electrolyte leakage. Therefore, our results suggest specific roles for aand g-tocopherol in vivo.

Integration of regulating power markets of different balancing regions has a potential to reduce ... more Integration of regulating power markets of different balancing regions has a potential to reduce the costs of balancing within multinational power markets by exchange of regulating power between these regions. Currently, most regulating power markets are operating on a national level so that exchange of regulating power between regions is minimal. This paper investigates the potentials for reduction of total balancing costs by creation of multinational regulating power markets studying the case study of Northern Europe; the Netherlands, the Nordic region and Germany. An optimization model is built to analyze the effects on total balancing costs - the costs paid by a multinational TSO to the providers of regulating power. Based on the numerical results, total balancing costs can decrease by 100 million Euros per year when enough interconnection capacity is allocated to balancing trade. Furthermore, total amount of activated regulating power is reduced due to supportive power exchange. Finally, the use of the uniform pricing mechanism leads to frequent congestion of interconnection lines due to balancing trade. On average, regulation power prices stay within the same range.

The optimal reactive power dispatch (ORPD) problem is formulated as a combinatorial optimization ... more The optimal reactive power dispatch (ORPD) problem is formulated as a combinatorial optimization problem involving nonlinear objective function with multiple local minima. In this paper, as a new approach, different ant colony optimization (ACO) algorithms are applied to the reactive power dispatch problem. Ant system (AS), the firstly introduced ant colony optimization algorithm, and its direct successors, elitist ant system (EAS), rank-based ant system (ASrank) and max-min ant system (MMAS), are employed to solve the reactive power dispatch problem. To analyze the efficiency and effectiveness of these modern search algorithms, the proposed methods are applied to the IEEE 30-bus system and the results are compared to those of conventional mathematical methods, genetic algorithm, evolutionary programming, and particle swarm optimization.

Electric Power Components and Systems, 2009

Abstract This article investigates the effect of a few types of ferroresonance suppression circui... more Abstract This article investigates the effect of a few types of ferroresonance suppression circuits on suppression of the phenomenon of ferroresonance in coupling capacitor voltage transformers. A novel technique is proposed for damping of dangerous overvoltages due ...

Scientometrics, 2010

Although there are many studies for quantifying the academic performance of researchers, such as ... more Although there are many studies for quantifying the academic performance of researchers, such as measuring the scientific performance based on the number of publications, there are no studies about quantifying the collaboration activities of researchers. This study addresses this shortcoming. Based on three measures, namely the collaboration network structure of researchers, the number of collaborations with other researchers, and the productivity index of co-authors, two new indices, the RC-Index and CC-Index, are proposed for quantifying the collaboration activities of researchers and scientific communities. After applying these indices on a data set generated from publication lists of five schools of information systems, this study concludes with a discussion of the shortcomings and advantages of these indices.

1 a.abbasy@tudelft.nl 2 r.a.vanderveen@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-Different cr... more 1 a.abbasy@tudelft.nl 2 r.a.vanderveen@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-Different cross-border arrangements for exchange of balancing services in electricity markets can potentially have different effects on the behavior of market parties and consequently market performance as a whole. This paper focuses on BSP-TSO trading (foreign bidding) as one of the main four arrangements proposed for exchange of balancing services across borders. We analyze the case of Norway and the Netherlands as a main balancing market integration case in Northern Europe and investigate the possible effect of enabling BSP-TSO trading (as one step towards full balancing market integration) between these countries on the performance of the two individual markets. An agent-based model is developed in MATLAB through which we study the possible change in behavior of market parties as a result of BSP-TSO trading implementation.

Synthetic Communications, 2008

... 2003, 44, 4927; (b) Lam, PYS; Vincent, G.; Bonne D.; Clark, CG; Deudon, S.; Jadhav, PK ... b)... more ... 2003, 44, 4927; (b) Lam, PYS; Vincent, G.; Bonne D.; Clark, CG; Deudon, S.; Jadhav, PK ... b) Nair, V.; Rajesh, C.; Vinod, AU; Bindu, S.; Sreekanth, AR; Mathen, JS; Balagopal, L. Strategies ... 5, 4273; (b) Nair, V.; Sreekanth, AR; Abhilash, N.; Biju, AT; Remadevi, B.; Menon, RS; Rath ...

1 r.a.c.vanderveen@tudelft.nl 2 a.abbasy@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-This paper... more 1 r.a.c.vanderveen@tudelft.nl 2 a.abbasy@tudelft.nl 3 r.a.hakvoort@tudelft.nl Abstract-This paper presents an agent-based analysis of the impact of different cross-border balancing arrangements on balancing market performance for the case of Northern Europe, i.e. the Netherlands, Germany and the Nordic region, taking into account the change in behaviour of Balance Responsible Parties (BRPs). The four compared arrangements are separate markets, Area Control Error (ACE) netting, balancing energy trading, and a common merit order list. It is found that ACE netting reduces the total Dutch imbalance costs by 25%, but that the more advanced arrangements have the potential to reduce those costs for the Netherlands and Germany by as much as 50%. However, in case of the common merit order list the imbalance risks for Nordic BRPs increase largely because of the regional marginal pricing, and the system balance states of Germany and the Nordic region are largely affected due to changes in BRP behaviour. The large imbalance costs reductions in Germany and the Netherlands are the result of the import of more than half of the balancing energy from the Nordic region, which is possible because of the high availability of cross-border capacity between the areas.

Dalton Transactions, 2004

Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetr... more Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) angstroms. EXAFS spectra yield a mean Sc-O bond distance of 2.09(1) angstroms for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been recorded, also of the deuterated compound, and analysed by means of normal coordinate methods, together with spectra of dimethyl sulfoxide. The effects on the vibrational spectra of the weak intermolecular C-H...O interactions and of the dipole-dipole interactions in liquid dimethyl sulfoxide have been evaluated, in particular for the S-O stretching mode. The strong Raman band at 1043.6 cm(-1) and the intense IR absorption at 1062.6 cm(-1) have been assigned as the S-O stretching frequencies of the dominating species in liquid dimethyl sulfoxide, evaluated as centrosymmetric dimers with antiparallel polar S-O groups. The shifts of vibrational frequencies and force constants for coordinated dimethyl sulfoxide ligands in hexasolvated trivalent metal ion complexes are discussed. Hexasolvated scandium(iii) ions are found in dimethyl sulfoxide solution and in [Sc(OSMe(2))(6)]I(3). The iodide ion-dipole attraction shifts the methyl group C-H stretching frequency for (S-)C-H...I(-) more than for the intermolecular (S-)C-H...O interactions in liquid dimethyl sulfoxide.

Acta Crystallographica Section E-structure Reports Online, 2006

Inorganic Chemistry, 2007

The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysp... more The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III), and lutetium(III) iodides crystallize in the monoclinic space group P21/n (No. 14) with Z = 4, while the octakis(DMSO) iodides of the larger lanthanum(III), cerium(III), and praseodymium(III) ions crystallize in the orthorhombic space group Pbca (No. 61), Z = 8. In all [Ln(OS(Me2)8]I3 compounds the lanthanoid(III) ions coordinate eight DMSO oxygen atoms in a distorted square antiprism. Up to three of the DMSO ligands were found to be disordered and were described by two alternative configurations related by a twist around the metal-oxygen (Ln-O) bond. To resolve the atomic positions and achieve reliable Ln-O bond distances, complete semirigid DMSO molecules with restrained geometry and partial occupancy were refined for the alternative sites. This disorder model was also applied on previously collected data for the monoclinic octakis(DMSO)yttrium(III) iodide. At ambient temperature, the eight Ln-O bond distances are distributed over a range of about 0.1 A. The average value increases from Ln-O 2.30, 2.34, 2.34, 2.36, 2.38, 2.40 to 2.43 A (Ln = Lu, Er, Y, Dy, Gd, Sm, and Nd) for the monoclinic [Ln(OSMe2)8]I3 structures, and from 2.44, 2.47 to 2.49 A (Ln = Pr, Ce, and La) for the orthorhombic structures, respectively. The average of the La-O and Nd-O bond distances remained unchanged at 100 K, 2.49 and 2.43 A, respectively. Despite longer bond distances and larger Ln-O-S angles, the cell volumes are smaller for the orthorhombic structures (Ln = Pr, Ce, and La) than for the monoclinic structure with Ln = Nd, showing a more efficient packing arrangement. Raman and IR absorption spectra for the [Ln(OS(CH3)2)8]I3 (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Er, Lu, and Y) compounds, also deuterated for La and Y, have been recorded and analyzed by means of normal coordinate methods. The force constants for the Ln-O and S-O stretching modes in the complexes increase with decreasing Ln-O bond distance and show increasing polarization of the bonds for the smaller and heavier lanthanoid(III) ions.

Inorganic Chemistry, 2007

Octakis(DMSO)lanthanoid(III) iodides (DMSO ) dimethylsulfoxide), [Ln(OS(CH 3 ) 2 ) 8 ]I 3 , of mo... more Octakis(DMSO)lanthanoid(III) iodides (DMSO ) dimethylsulfoxide), [Ln(OS(CH 3 ) 2 ) 8 ]I 3 , of most lanthanoid(III) ions in the series from La to Lu have been studied in the solid state and in DMSO solution by extended X-ray absorption fine structure (EXAFS) spectroscopy. L 3 -edge and also some K-edge spectra were recorded, which provided mean Ln−O bond distances for the octakis(DMSO)lanthanoid(III) complexes. The agreement with the average of the Ln−O bond distances obtained in a separate study by X-ray crystallography was quite satisfactory. The crystalline octakis(DMSO)lanthanoid(III) iodide salts have a fairly broad distribution of Ln−O bond distances, ca. 0.1 Å, with a few disordered DMSO ligands. Their EXAFS spectra are in excellent agreement with those obtained for the solvated lanthanoid(III) ions in DMSO solution, both of which show slightly asymmetric distributions of the Ln−O bond distances. Hence, all lanthanoid(III) ions are present as octakis(DMSO)lanthanoid(III) complexes in DMSO solution, with the mean Ln−O distances centered at 2. This decrease in the Ln−O bond distances is larger than expected from the previously established ionic radii for octa-coordination. This indicates increasing polarization of the Ln III −O(DMSO) bonds with increasing atomic number. However, the S(1s) electron transition energies in the sulfur K-edge X-ray absorption near-edge structure (XANES) spectra, probing the unoccupied molecular orbitals of lowest energy of the DMSO ligands for the [Ln(OS(CH 3 ) 2 ) 8 ] 3+ complexes, change only insignificantly from Ln ) La to Lu. This indicates that there is no appreciable change in the σ-contribution to the S−O bond, probably due to a corresponding increase in the contribution from the sulfur lone pair to the bonding. (1) Abbasi, A.; Lindqvist-Reis, P.; Eriksson, L.; Sandström, D.; Lidin, S.; Persson, I.; Sandström, M. Chem. Eur.

Acta Crystallographica Section E-structure Reports Online, 2006

In the title compound, trans-[RuCl2 (C2H6S) 4], the RuII ion, located on a special position (4a) ... more In the title compound, trans-[RuCl2 (C2H6S) 4], the RuII ion, located on a special position (4a) with crystallographically imposed symmetry, coordinates four S atoms from the dimethyl sulfide molecules and two chloride ions in an octahedral trans configuration. All atoms, ...

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2005

Infrared (IR), far-infrared (far-IR) and Raman spectra have been recorded of the hydrated lanthan... more Infrared (IR), far-infrared (far-IR) and Raman spectra have been recorded of the hydrated lanthanide(III) trifluoromethanesulfonates, [Ln(OH2)9](CF3SO3)3, (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), and also for the deuterated [La(OD2)9](CF3SO3)3 compound. This has enabled complete assignments of all seven metal-oxygen stretching modes for the first time. Force constant calculations have been performed for an LnO9(3+) moiety, with a tricapped trigonal prismatic oxygen atom arrangement in D3h point group symmetry. The lanthanide contraction in reflected in continuously increasing trends for the averaged LnO stretching frequencies and force constants with increasing inverse of ionic radii. The stretching force constants increased from 0.81 to 1.16 Ncm-1 for the LnO6 prism in the series from La to Lu, while those for the capping LnO3 bonds increased from 0.49 to 0.65 Ncm-1. The LnO stretching force constants showed a smooth correlation with the LnO bond distances to the prism oxygen atoms, while the correlation to the LnO capping oxygen atoms has a different shape, reflecting the increased ligand-ligand repulsion with decreasing lanthanide ion size.

Chemistry-a European Journal, 2005

Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped t... more Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in a large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for the smallest metal ions in the isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)n](CF3SO3)3, in which M=ScIII, LuIII, YbIII, TmIII or ErIII. The hydration number n increases (n=8.0(1), 8.4(1), 8.7(1), 8.8(1) and 8.96(5), respectively) with increasing ionic size. Deuterium (2H) solid-state NMR spectroscopy revealed fast positional exchange between the coordinated capping and prism water molecules; this exchange started at temperatures higher than about 280 K for lutetium(III) and below 268 K for scandium(III). Similar positional exchange for the fully nonahydrated yttrium(III) and lanthanum(III) compounds started at higher temperatures, over about 330 and 360 K, respectively. An exchange mechanism is proposed that can exchange equatorial and capping water molecules within the restrictions of the crystal lattice, even for fully hydrated lanthanoid(III) ions. Phase transitions occurred for all the water-deficient compounds at ≈185 K. The hydrated scandium(III) trifluoromethanesulfonate transforms reversibly (ΔH°=−0.80(1) kJ mol−1 on cooling) to a trigonal unit cell that is almost nine times larger, with the scandium ion surrounded by seven fully occupied and two partly occupied oxygen atom positions in a distorted capped trigonal prism. The hydrogen bonding to the trifluoromethanesulfonate anions stabilises the trigonal prism of water ligands, even for the crowded hydration sphere of the smallest metal ions in the series. Implications for the Lewis acid catalytic activity of the hydrated scandium(III) and lanthanoid(III) trifluoromethanesulfonates for organic syntheses performed in aqueous media are discussed.