Azarbaijan Shahid Madani University

About: Azarbaijan Shahid Madani University is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Graphene & Nanocomposite. The organization has 1477 authors who have published 3186 publications receiving 30278 citations. The organization is also known as: Azarbaijan University.

Efficacy beyond 17% via engineering the length and quality of grafts in organic halide perovskite/CNT photovoltaics

Abstract: Pure carbon nanotubes (CNTs) and their derivatives grafted with the regiorandom poly(3-dodecyl thiophene) (CNT-g-PDDT) and regioregular poly(3-hexylthiophene) (CNT-g-P3HT) polymers were employed to improve the morphological, optical, and photovoltaic properties of CH3NH3PbI3 perovskite solar cells. Although the grafted CNT components improved the cell characteristics, bare CNTs destroyed them. The regioregularity and graft length influences were investigated on the system behavior. The CNT nanostructures grafted with the shorter P3HT backbones demonstrated the best results, i.e., 79.9 Ω, 23.60 mA cm−2, 76%, 0.97 V and 17.40%. This originated from the higher crystalline peak intensities for both P3HT (5.6–5.8°) and CH3NH3PbI3 (14.81, 20.91, 24.11, 29.21 and 32.51°) precursors and also the larger grain sizes (5 (600 nm) versus 50 (490 nm) kDa). The perovskite + CNT-g-P3HT devices, in particular the CNTs with shorter grafts, possessed faster electron transport and lower carrier recombination compared with the other solar cells, as evidenced by the larger short-circuit current density.

Multi-Stage Planning of Distribution Networks with Application of Multi-Objective Algorithm Accompanied by DEA Considering Economical, Environmental and Technical Improvements

Abstract: The regards to widespread impact of distribution networks and ever increasing demand for electricity, some strategies must be devized in order to well operate the distribution networks. In this paper, to enhance the accountability of the power system and to improve the system performance parameters, simultaneous placement of renewable energy generation (REG) sources (e.g., wind, solar and dispatchable distributed generators (DGs)) and capacitors are investigated in a modified radial distribution network with considering ZIP loads. To enhance all network parameters simultaneously to the best possible condition multi-objective functions are proposed and solved using non-dominated sorting genetic algorithm (NSGA II). The employed objectives contain all economical, environmental and technical aspects of distribution network. One of the most important advantages of the proposed multi-objective formulation is that it obtains non-dominated solutions allowing the system operator (decision maker) to exercise his/her personal preference in selecting each of those solutions based on the operating conditions of the system and the costs. It is clear that the implementation of each non-dominated solution needs related costs according to the technology used and the system performance characteristics. However, there is a paucity of objective methodologies for ranking the obtained non-dominated solutions considering economical, environmental and technical aspects. So, in this paper, data envelopment analysis (DEA) is suggested for this purpose. In other words, in this paper, first NSGA II is applied to the siting and sizing problem, and then the obtained non-dominated solutions are prioritized by DEA. The significant advantage of using DEA is that there is no need to impose the decision maker’s idea into the model and ranking is done based on the efficiencies of the non-dominated solutions. The most efficient solution is the one which has improved network parameters considerably and has lowest costs. So, using DEA gives a realistic view of solutions and the provided results are for all, not for a specific decision maker. To validate the effectiveness of the proposed scheme, the simulations are carried out on a modified test case 33-bus radial distribution network.

The signed Roman domatic number of a digraph

Abstract: Let $D$ be a finite and simple digraph with vertex set $V(D)$.A {\em signed Roman dominating function} on the digraph $D$ isa function $f:V (D)\longrightarrow \{-1, 1, 2\}$ such that$\sum_{u\in N^-[v]}f(u)\ge 1$ for every $v\in V(D)$, where $N^-[v]$ consists of $v$ andall inner neighbors of $v$, and every vertex $u\in V(D)$ for which $f(u)=-1$ has an innerneighbor $v$ for which $f(v)=2$. A set $\{f_1,f_2,\ldots,f_d\}$ of distinct signedRoman dominating functions on $D$ with the property that $\sum_{i=1}^df_i(v)\le 1$ for each$v\in V(D)$, is called a {\em signed Roman dominating family} (of functions) on $D$. The maximumnumber of functions in a signed Roman dominating family on $D$ is the {\em signed Roman domaticnumber} of $D$, denoted by $d_{sR}(D)$. In this paper we initiate the study of signed Romandomatic number in digraphs and we present some sharp bounds for $d_{sR}(D)$. In addition, wedetermine the signed Roman domatic number of some digraphs. Some of our results are extensionsof well-known properties of the signed Roman domatic number of graphs.