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671.
Yusuf Emre Güner 《European Journal of Operational Research》2018,264(1):310-326
In this study, a new method is developed to determine the least cost capacity expansion of a power system by using the screening curve method. The proposed methodology differs from the previous studies by its geometrical solution process to evaluate a capacity expansion problem considering both existing and candidate power plants. The algorithms are computationally more efficient and simple than the ones in previous studies for the same improvement. Further, the interpretation of the optimal capacity expansion plan is enhanced by explicitly exhibiting the results of all considered capacity expansion alternatives. The solution process can be interpreted as minimizing the long run marginal cost of supplying 1 megawatt of capacity during the whole year by finding the optimal combination of units. The developed method calculates and finds the cost polygon with the minimum area by moving along the intersection points of the screening curves to form trapezoids and then joining them to form cost polygons. The intersection points, which are needed to calculate the areas of the cost polygons, are found by using the Karush–Kuhn–Tucker conditions in a recursive manner. The last unit in the merit order of dispatching is determined by scenarios to yield an optimal capacity expansion plan. The scenarios are primarily based on a tradeoff between incurring investment costs by commissioning candidate units or taking online existing units with relatively higher variable costs compared to the candidate units. 相似文献
672.
Yusuf Civan 《Journal of Combinatorial Theory, Series A》2007,114(7):1315-1331
A vertex coloring of a simplicial complex Δ is called a linear coloring if it satisfies the property that for every pair of facets (F1,F2) of Δ, there exists no pair of vertices (v1,v2) with the same color such that v1∈F1?F2 and v2∈F2?F1. The linear chromatic numberlchr(Δ) of Δ is defined as the minimum integer k such that Δ has a linear coloring with k colors. We show that if Δ is a simplicial complex with lchr(Δ)=k, then it has a subcomplex Δ′ with k vertices such that Δ is simple homotopy equivalent to Δ′. As a corollary, we obtain that lchr(Δ)?Homdim(Δ)+2. We also show in the case of linearly colored simplicial complexes, the usual assignment of a simplicial complex to a multicomplex has an inverse. Finally, we show that the chromatic number of a simple graph is bounded from above by the linear chromatic number of its neighborhood complex. 相似文献
673.
Yusuf DANISMAN 《数学年刊B辑(英文版)》2017,38(4):1019-1036
The L-factor of irreducible x1×x2(×)σ defined by Piatetski-Shapiro is computed by using non-split Bessel functional. 相似文献
674.
675.
The photoinitiated cationic polymerization of cyclohexene oxide with N‐phenacyl‐N,N‐dimethylanilinium hexafluoroantimonate (PDA+SbF6–) and a polynuclear aromatic compound, such as perylene, anthracene or phenothiazine, or an aromatic carbonyl compound, such as benzophenone or thioxanthone, was studied at λinc > 340 nm. All the aromatic sensitizers except benzophenone and thioxanthone are effective in initiating the polymerization at wavelengths where PDA+SbF6– is transparent. An initiation mechanism is proposed that involves electron transfer from the excited sensitizer to PDA+SbF6–. 相似文献
676.
Yusuf Yagci 《Macromolecular Symposia》2000,161(1):19-36
This paper on recent developments in the use of photoinitiating systems in polymer synthesis concentrates on: (i) the possiblity of controlled//living polymerization by photopolymerization, (ii) major photoinitiating systems for both cationic and radical polymerization and (iii) preparation of block copolymers and functional polymers by photoinduced processes. Much progress has been made in the past ten years in preparation of block copolymers by photoinduced reactions of either chromophoric groups incorporated into polymers or low‐molecular‐weight compounds with suitable functional groups present in polymer chains. 相似文献
677.
Tugberk Tabak Kerem Kaya Recep Isci Turan Ozturk Yusuf Yagci Baris Kiskan 《Macromolecular rapid communications》2024,45(2):2300455
A novel method based on light-induced fabrication of a poly (3,4-ethylenedioxythiophene)-polycaprolactone (PEDOT-PCL) scaffold using phenacyl bromide (PAB) as a single-component photoinitiator is presented. HBr released from the step-growth polymerization of EDOT is utilized as an in situ catalyst for the chain-growth polymerization of ε-caprolactone. Detailed investigations disclose the formation of a self-assembled nanoporous electroconductive scaffold (1.2 mS cm−1). Fluorescence emission spectra of the fabricated scaffold exhibit a mixed solvatochromic behavior, indicating specific interactions between the self-assembled scaffold and solvents with varying polarities, as evidenced by transmission electron microscopy (TEM). Moreover, the same light-induced technique can also be applied for bulk photopolymerization showcasing the versatility and wide-ranging scope of the originated method. In brief, this study introduces a novel approach for light-induced polymerization reactions that is merging step-growth and chain-growth mechanisms. This innovative approach is promising to facilitate in situ polymerization of monomers possessing diverse functionalities. 相似文献
678.
The compounds 2‐thioxanthone‐thioacetic acid and 2‐(carboxymethoxy)thioxanthone, bimolecular photoinitiators for free radical polymerization, are synthesized and characterized. Their capability to act as initiators for the polymerization of methyl methacrylate was examined. The postulated mechanism is based on the intermolecular electron‐transfer reaction of the excited photoinitiator with the sulfur or oxygen atom of the ground state of the respective photoinitiator followed by decarboxylation. The resulting alkyl radicals initiate the polymerization.