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Let G be a simple graph of order n. The domination polynomial of G is the polynomial D(G,x)=σi=1 nd(G,i)xi, where d(G,i) is the number of dominating sets of G of size i. A root of D(G,x) is called a domination root of G. We denote the set of distinct domination roots by Z(D(G,x)). Two graphs G and H are said to be D-equivalent, written as G~H, if D(G,x)=D(H,x). The D-equivalence class of G is [G]={H:H~G}. A graph G is said to be D-unique if [G]={G}. In this paper, we show that if a graph G has two distinct domination roots, then Z(D(G,x))={-2,0}. Also, if G is a graph with no pendant vertex and has three distinct domination roots, then Z(D(G,x)). Also, we study the D-equivalence classes of... 

In a given graph G, a set S of vertices with an assignment of colors to them is a defining set of vertex coloring for G, if there exists a unique extension of the colors of 5 to a X(G)-coloring of the vertices of G. A defining set with minimum cardinality is called a smallest defining set (of vertex coloring) and its cardinality, the defining number, is denoted by d(G,X)- Mahmoodian et al. (1999) determined the defining number of graph C3 × Cn. In this paper, we study the defining number of graph Cm × Cn, and show that Also, we prove a similar result for the defining number of graph Cn × Pn  

Failure in sheet metal forming can occur by necking, fracture or wrinkling. By using a forming limit diagram (FLD) as a powerful tool to prevent sheets metal failures in the forming process, provides parameters controlling throughout forming. There are different developed methods for predicting FLDs, which estimate sheet metal forming strains limits. Assessment of FLD estimation reveals that there is a dependency between the effect of several factors containing normal stress, shear stress, sheet thickness, mechanical properties, metallurgical properties, yield function, strain path, and bending with formability. In this research, the effects of bending via two finite element models are... 

In this paper, a new cache placement scheme is proposed to achieve higher hit ratios with respect to the two conventional schemes namely set-associative and direct mapping. Similar to set-associative, in this scheme, cache space is divided into sets of different sizes. Hence, the length of tag fields associated to each set is also variable and depends on the partition it is in. The proposed mapping function has been simulated with some standard trace files and statistics are gathered and analyzed for different cache configurations. The results reveal that the proposed scheme exhibits a higher hit ratio compared to the two well-known mapping schemes, namely set-associative and direct mapping,... 

Unlocking the full potential of advanced high-strength bainitic steels in spot-welding is a pivotal endeavor for harnessing their extraordinary mechanical properties in the automotive industry. This study suggests a shift in paradigm to address the inferior fusion weldability of this type of steel because of the formation of coarse martensite within the welded zone of weldments obtained by liquid-state welding, through the strategy of refining the martensite within the weld zone using the solid-state friction stir spot welding (FSSW) process. This paper delves into an in-depth investigation of the microstructural evolution and load-bearing capacity of a Fe-0.25C-3Cr-1.63Mn-1.5Si (wt%)... 

Optimization of the fiber angle in the laminated composite material to achieve the highest strength or stability has great importance in structural design. In the present study, we aim to utilize genetic algorithm (GA) and particle swarm optimization (PSO) together to find the best angle of composite layers in a multilayer cylindrical shell structure. To this aim, a detailed formulation of the composite cylindrical structure is presented using nonlocal strain gradient theory (NSGT), zigzag theory, and Hamilton's principle for a shear deformable shell displacement field. The modal equations of motion are further solved using the general differential quadrature element method (GDQEM). Having... 

Drawing on the associative network memory theory (ANMT), this study aims to investigate the impact of social media marketing activities (SMMAs) on brand equity (BE) of luxury brands through the mediating role of brand image (BI) and the moderating role of word of mouth (WOM). This study employs a cross-sectional design to collect data from online adult users of Weibo in China. Data are analyzed in SmartPLS (v. 4.0.8.4) to evaluate the measurement model and the structural model. Findings of this study reveal that SMMAs have a significant positive impact on BI and BE. Besides, BI partially mediates the relationship between SMMAs and BE. Moreover, WOM moderates the association between SMMAs and... 

The AA7075 high-strength aluminum alloy exhibits a pronounced tendency for hot cracking during fusion welding, which hampers its widespread utilization in lightweight design concepts. This study aims to investigate the effectiveness of friction stir processing (FSP) as a pre-weld treatment to eliminate the occurrence of hot cracking during fusion welding of the AA7075 aluminum alloy. Our findings demonstrate that the FSP pre-weld treatment successfully suppresses liquation cracking in the AA7075 alloy, even when utilizing ER1050 filler metal for welding, which poses a considerable risk of liquation cracking. The FSP treatment induces a transformative effect on the microstructure of the... 

In the current research, a three-dimensional photovoltaic thermal system integrated with phase change material system with nanofluids is investigated. The working fluids involved in this study include nano-magnesium oxide, multiwall carbon nano tube and hybrid (mixture of nano-magnesium oxide and nano-multiwall carbon nano tube) nanofluids dispersed in pure water. After comparing single-phase model and mixture model, the mixture model is used in the study and fluid flow regime in the collector is assumed to be laminar, fully develop, uniform and incompressible, to model the nanofluid in the system. A parametric analysis is conducted to examine the effect of various parameters such as working... 

Martensitic stainless steel (MSS) spot welds show low fracture toughness due to the formation of a brittle microstructure at the joint area. To realize the full advantage of this class of steels in industrial applications, the strategy of altering the microstructure of the weld nugget through introduction of a Ni interlayer was investigated. For this purpose, Ni interlayers with variable thicknesses of 50 to 400 μm were utilized. The microstructural evolutions were thoroughly scrutinized using Scheil-Gulliver solidification modeling and electron backscatter diffraction (EBSD) analysis. Conventional quasi-static mechanical tests, namely, tensile-shear (TS) and cross-tension (CT) were used to... 

The bifacial photovoltaic/thermal module is an emerging concept that can provide electricity and heat simultaneously, taking advantage of both front and rear sides of the panel; therefore, exhibiting a better performance compared to a conventional photovoltaic module or photovoltaic thermal module. In this study, four configurations of the bifacial photovoltaic/thermal module with different cooling methods have been proposed, i.e., cooling performed at either the upper or the lower surface, in parallel (applied to both upper and lower surfaces having similar start/endpoints), and swinging air back and forth (by guiding the air over the upper and lower surfaces, respectively). The... 

Zeolitic imidazole frameworks (ZIFs) provide an exciting platform to design and fabricate non-precious-metal carbon-based catalysts for oxygen reduction/evolution reaction (ORR/OER). Herein, we elaborately design a facile enzyme-assisted synthetic strategy that enables to tailor the ZIFs precursors into structural stable decussation shape, which derived Co nanoislands grafted on decussate N-doped carbon nanoleaves (D-Co@NC) can well retain the interpenetrating nanostructure. Benefiting from the combined advantages of compositions and interpenetrating nanostructures, D-Co@NC possesses 5.2 times higher exposed electrochemical active area than the conventional dodecahedral one, thus endowing... 

Learning a foreign language encompasses a process of trial and error that can lead to the progression of the learner's interlanguage, meaning that the learners make use of their language knowledge that receives feedback and brings about progress through diagnosis of the problems and being corrected by the teacher. Therefore, there exists a need to analyze the underlying reasons causing the students to remain taciturn with a low willingness to communicate (WTC) during a language class. There has been much work done investigating the role of the learner's stable personal characteristics (traits) along with their situational changes at a specific time (states) that influence the student's... 

Accurate system identification (SI) is essential for flight controller design of unmanned aerial vehicles and microaerial vehicles (MAVs). SI can be performed either in frequency or time domain using flight test data. As flight testing is often costly and may even lead to catastrophic events before some flight stability analysis is at hand, a low-cost 5 degree-of-freedom free motion platform (FMP) is designed and used for initial identification of MAVs via wind tunnel testing. A typical MAV is constructed as a test case and equipped with inertial sensors for testing and validation purposes. The proposed FMP allows for both rotational as well as translational motions that in turn provide for... 

Using 3-D scanned data to analyze and extract pore network plays a vital role in investigation of porous media's characteristics. In this paper, a new simple method is developed to detect pores and throats for analyzing the connectivity and permeability of the network. This automated method utilizes some of the common and well-known image processing functions which are widely accessible by researchers and this has led to an easy algorithm implementation. In this method, after polishing and quality control of images, using city-block distance function and watershed segmentation algorithm, pores and throats are detected and 3-D network is produced. This method can also be applied on 2-D images... 

In this paper, we try to recognize and distinguish different groups of arrhythmia using novel features which have been obtained from the heart rate's phase space in recent years. For this purpose, we used Triangular Phase Space Mapping (TPSM) and Parabolic Phase Space Mapping (PPSM). For recognition, we used three groups of 15 subjects using the Physionet database (Arrhythmia, Congestive Heart Failure (CHF), and Atrial Fibrillation (AF)) with Normal Sinus Rhythm (NSR). The obtained features discriminate arrhythmia from NSR by p