SUMMARYThis paper presents a new method to determine the locations and sizes of Distributed Generations (DGs) for loss reduction and voltage profile enhancement in distribution systems. The strategic placement of DG can help reduce power losses and improve feeder voltage profile. Fuzzy Goal Programming (FGP) is adopted to handle the multiobjective DG placement problem incorporating the voltage characteristics of each individual load component. The original objective functions and constraints are transformed into the multiobjective function with fuzzy sets by FGP. The transformed multiobjective function with fuzzy sets represents the imprecise natures for criterion of loss reduction and voltage profile enhancement, and the number and total capacities of DGs. The solution of the transformed multiobjective function with fuzzy sets is searched by Genetic Algorithm (GA). The proposed method is tested on the IEEE 34-bus system to demonstrate its effectiveness.
A novel HOCl signaling probe based on the oxidative hydrolysis of resorufin carbonodithioate to generate resorufin dye was investigated and applied to cell imaging.
Additive engineering of perovskite
solar absorbers has been considered
an efficient protocol for fabricating highly efficient and stable
solar cells. Organic additives such as polymers and small molecules
efficiently passivate defect sites and thereby reduce charge trapping
and recombination, which significantly improves the performance and
environmental stability of perovskite devices. However, stiff polymer
chains or hard organic crystals with a high transition temperature
can generate pin holes via rapid phase separation from perovskite.
Using liquid-phase additives during the crystallization of perovskite
can assist in obtaining desirable film morphologies and passivating
defect sites. Ethyl carbamate (EC) was employed in this study as a
soft small-molecule additive with a low melting point (∼50
°C). Highly mobile EC molecules detach from the perovskite matrix
and diffuse to the grain boundaries to reduce the boundary energy.
The resulting films were composed of large grains and selectively
passivated grain boundaries. The power conversion efficiency (PCE)
of fabricated solar cells improved from 19.51 to 22.25% upon the incorporation
of the additive. Moreover, the device exhibited an excellent PCE retention
of 93.5% of the initial value for 1200 h at a relative humidity of
20%.
In this study, we synthesized two acceptor− donor−acceptor (A−D−A)-type small molecules (SMs) (P3T4−VCN and P3T4−INCN) with different terminal end-groups (dicyanovinyl (VCN) and 2-methylene-3-(1,1dicyanomethylene)indanone (INCN)) based on the 1,4bis(thiophenylphenylthiophene)-2,5-difluorophenylene (P3T4) core that possesses high coplanarity because of intrachain noncovalent Coulombic interactions. We investigated the influence of terminal end-groups on intermolecular packing and the resulting electrical and photovoltaic characteristics. A small change in the end-group structure of the SMs induces a significant variation in the torsional structures, molecular packing, and pristine/blend film morphology. It is noteworthy that the less crystalline P3T4−INCN with tilted conformation is highly sensitive to post-treatments (i.e., additives and annealing) such that it permits facile morphological modulation. However, the highly planar and crystalline P3T4−VCN exhibits a strong tolerance toward processing treatments. After morphology optimization, the fullerene-based bulkheterojunction solar cell of tilted P3T4−INCN exhibits a power conversion efficiency (PCE) of 5.68%, which is significantly superior to that of P3T4−VCN:PC 71 BM (PCE = 1.29%). Our results demonstrate the importance of the terminal end-group for the design of A−D−A-type SMs and their sensitivity toward the postprocessing treatments in optimizing their performance.
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