1,721,190 research outputs found
Kang-Joon Heo
No full text학위논문(석사)--아주대학교 일반대학원 :에너지시스템학과,2020. 8I. Introduction 1
II. Modellingthe marginal price and electric bill 5
II.A. Marginal buying price model 6
II.A.1. Cumulative rate (Block rate pricing) 6
II.A.2. Time of use (TOU) and other tariffs 8
II.B. Marginal selling price model 10
II.B.1. Net metering system 10
II.B.2. DERs sales system 11
II.C. Service charges model 13
II.C.1. Platform service charge (PSC) 13
II.C.2. Network usage charge (NUC) 16
II.D. The transition of the electric bill before/after P2P trading 19
III. Modelling P2P energy trading and its algorithm formulation 21
III.A. Trade price determination 22
III.B. Matching algorithm formulation 23
III.C. Overall trading process and price modulation 27
IV. Case study 31
IV.A. Simulation assumption 31
IV.A.1. Input data description 32
IV.A.2. Tariff description 34
IV.B. Service charge calculation results 37
IV.C. Simulation results for a day 38
IV.C.1. Price determination results 38
IV.C.2. Matching results 40
IV.D. Simulation results for the month 43
IV.D.1. Price modulation results for block rate pricing 43
IV.D.2. Matching results for the month 45
IV.D.3. Service charge calculation results for the month 49
V. Conclusion 51
References 52MasterThis paper proposes a peer-to-peer (P2P) energy trading model to be integrated in the existing distribution system. For this, the operator-oriented trading scheme is developed to lower the barriers to entry into the P2P trading. Under this, the operator, rather than each participant, decides the trading price and trading schedules. To determine the trading price, the marginal price that accommodates various electric tariffs and sales systems are derived. The analysis for the wide range of tariffs and sales system has been conducted to be a trading model that accommodate a variety of current customers in the trading. Furthermore, to be a feasible trading model, service charges that include network usage charge and platform service charge are also derived. The former targets to compensate the utility company’s support that allows participants to trade energy and the latter ensures the platform operator’s economic benefit. Both service charges model
draws the relevant entities’ participations to P2P trading. Based on the derived elements mentioned above, a matching algorithm is finally formulated. For this, a constrained optimization problem is derived, and Lagrange multiplier method is applied to make optimal trading schedule that results in maximizing social welfare
while preventing imbalances in revenue between sellers and buyers. To verify the performance of the proposed P2P trading scheme, actual data for various types of load and distributed energy resources is applied on the IEEE 18 bus distribution system
NHC-Catalyzed 1,2-Selective Hydroboration of Quinolines
No full text© 2020 American Chemical Society.Selective dearomative transformation of readily available N-heteroarenes is a powerful tool accessing useful synthetic building units. Described herein is the NHC-catalyzed 1,2-selective hydroboration of quinolines with high functional group tolerance. Dihydroquinoline products could be isolated as their amide derivatives upon in situ N-protection, thus offering high synthetic utility of the current procedure. Combined experimental and computational studies revealed that the observed regioselectivity can be rationalized by proposing a six-membered transition state that collectively incorporates NHC catalyst, hydroborane reductant, and protonated quinoline substrate11sciescopu
KO tBu-Catalyzed 1,2-Silaboration of N-Heteroarenes to Access 2-Silylheterocycles: A Cooperative Model for the Regioselectivity
No full text© 2022 American Chemical Society.Reductive functionalization of N-heteroarenes offers a route to highly versatile heterocyclic synthons bearing multiple transformable groups. We present herein the development of KOtBu-catalyzed 1,2-silaboration of a broad range of N-heteroarenes, affording heterocyclic allylamines or enamines with the formation of a sp3 C2-Si bond. These labile compounds were isolated either as their N-acyl derivatives or as rearomatized 2-silyl-N-heteroarenes by the one-pot procedures. A model of the six-membered ion-pair complex was proposed to rationalize the observed 1,2-regioselectivity, wherein KOtBu catalyst plays an associative role in activating the substrate and silylborane reagent.11Nsciescopu
Ring-opening functionalizations of unstrained cyclic amines enabled by difluorocarbene transfer
No full textChemical synthesis based on the skeletal variation has been prolifically utilized as an attractive approach for modification of molecular properties. Given the ubiquity of unstrained cyclic amines, the ability to directly alter such motifs would grant an efficient platform to access unique chemical space. Here, we report a highly efficient and practical strategy that enables the selective ring-opening functionalization of unstrained cyclic amines. The use of difluorocarbene leads to a wide variety of multifaceted acyclic architectures, which can be further diversified to a range of distinctive homologative cyclic scaffolds. The virtue of this deconstructive strategy is demonstrated by successful modification of several natural products and pharmaceutical analogues. Cyclic amines are commonly present in natural products and synthetic compounds, but methods for their skeletal diversification are limited. Here, the authors report a strategy for selective ring-opening functionalization of unstrained cyclic amines to pluripotent products that can be further diversified.11sciescopu
On the Origin of Rh-Catalyzed Selective Ring-Opening Amidation of Substituted Cyclopropanols to Access β2-Amino Ketones
No full text© β2-Amino carbonyls, an α-substituted β-amino scaffold, hold a prominent place in the development of new pharmaceuticals and peptidomimetics. Herein, we report a highly efficient Rh-catalyzed ring-opening amidation of substituted cyclopropanols, which turned out to serve as a linchpin for the selective synthesis of β2-amino ketones to outcompete the formation of β3-isomers. Instead of the generally accepted rationale to consider steric factors for the β2-selectivity, orbital interaction was elucidated to play a more critical role in the amidative ring-opening of cyclopropanols to generate the key Rh-C intermediate. Subsequent inner-sphere acylnitrene transfer was achieved in excellent efficiency (TON > 5000) by using readily accessible dioxazolones as the amino source to afford β2-amino ketones with broad applicability.11Nsciescopu
Copper-Mediated Amination of Aryl C–H Bonds with the Direct Use of Aqueous Ammonia via a Disproportionation Pathway
No full textThe direct amination
of C–H bonds with ammonia is a challenge
in synthetic chemistry. Herein, we present a copper-mediated approach
that enables a chelation-assisted aromatic C–H bond amination
using aqueous ammonia. A key strategy was to use soft low-valent Cu(I)
species to avoid the strong coordination of ammonia. Mechanistic investigations
suggest that the catalysis is initiated by a facile deprotonation
of bound ammonia, and the C–N coupling is achieved by subsequent
reductive elimination of the resultant copper–amido intermediate
from a Cu(III) intermediate that is readily generated by disproportionation
of low-valent copper analogues. This mechanistic postulate was supported
by a preliminary kinetic isotope effect study and computations. This
new chelation-assisted, copper-mediated C–H bond amination
with aqueous ammonia was successfully applied to a broad range of
substrates to deliver primary anilines. Moreover, the mild conditions
required for this transformation allowed the reaction to operate even
under substoichiometric conditions to enable a late-stage application
for the preparation of pharmaceutical agents
Electro-inductive effect: Electrodes as functional groups with tunable electronic properties
No full text© 2020, The Authors. In place of functional groups that impose different inductive effects, we immobilize molecules carrying thiol groups on a gold electrode. By applying different voltages, the properties of the immobilized molecules can be tuned. The base-catalyzed saponification of benzoic esters is fully inhibited by applying a mildly negative voltage of -0.25 volt versus open circuit potential. Furthermore, the rate of a Suzuki-Miyaura cross-coupling reaction can be changed by applying a voltage when the arylhalide substrate is immobilized on a gold electrode. Finally, a two-step carboxylic acid amidation is shown to benefit from a switch in applied voltage between addition of a carbodiimide coupling reagent and introduction of the amine11sciescopu
Schrock vs Fischer carbenes: A quantum chemical perspective
No full textEarly and late transition metal-carbon multiple bonds that have been widely used for many catalytic processes, organic transformations, and olefin metathesis reactions are described. Especially, the development of Schrock and Fischer type olefin metathesis catalysts aided by computational studies is discussed, focusing on work that aims at improving the reactivity, stability, and regioselectivity. The intriguing electronic feature and reactivity of a titanium alkylidyne, which leads to many unique transformations of organic molecules, are summarized. The development of Fischer type olefin metathesis catalysts to control the regioselectivity in cyclopolymerization of diynes with RuII-alkylidene catalysts employing quantum chemical studies is summarized. © 2019 Elsevier Inc.11sci
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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