Background and Objective: Efforts to improve the effectiveness of noise barriers have been made, including shape, aesthetics, form and gender. Therefore, the aim of this study was to investigate the effect of the angle upper edge in shaped noise barriers with a T-shaped upper edge. Materials and Methods: A 2D boundary element method (BEM) was used to predict the insertion loss of the tested barriers. The results obtained from the angular obstructions of the upper edge with the upper T-face were compared. Results: The design of the angular barriers of the upper edge in the shape of the barrier caused a significant increase in the insertion loss performance, especially in the low frequency range, as compared to the upper T-shaped face. The highest amount of insertion loss in the angular barriers of the upper edge in the shaped barriers was estimated to be 3. 79 dB (A) above the upper edge of T, which usually depends on the relative dimensions and position relative to the source and location of the receiver. The results of this study showed that among the tested models to determine the efficiency, the best noise barrier for controlling the traffic noise was the angular barrier with a high angle of 19 degrees compared to the other higher angles and a simple T barrier at a frequency of 315, 400, 500, and 630 Hz was obtained. Conclusion: The performance of the barriers in the case of applying the angle at the upper edge on the T-shaped barrier surface is improved in comparison with the use of a simple T-barrier in lower frequencies. In this regard, the best form for applying angular obstructions with a high angle was about 19 degrees from the horizon. . The cause of this effect was the presence of a failure and reflection of the angled edges in the direction of transmission of sound wave from source to receiver. All angular barrier are able to increase the barrier performance at a specific frequency range, especially at low frequencies.

Aim: This study was designed to determine any profile changes and indentify the role of the most significant factors responsible for these changes.Materials and Methods: Cephalograms of 56 class II Division I patients (36 female and 18 male with mean age of 10 years) were used to analysis any changes in the perioral soft tissue profile before and after the treatment. A correlation analysis and multiple regression analysis (forward) revealed complex interaction between dentition, bony structures and soft tissues of the perioral area.Results: Retraction at the upper lip and increase in lower lip length in boys were more predictable than that of others. Significant soft tissue changes occured in response to orthodontic treatment, Upper lip retraction was shown to be related to the following factors: a- Retraction of upper incisal edges during treatment, b-Retraction of Point A, c- Pretreatment upper sulcus thickness and d- Retraction of sulcus superior.Conclusion: A greater increase in lower lip length takes place with greater amount of maxillary incisa1 edge retraction during treatment and a greater amount of sulcus superior retraction.

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The edge-tenacity Te(G) of a graph G was de ned as Te(G) = min F E(G) f j F j + (G 􀀀 F)! (G 􀀀 F) g where the minimum is taken over all edge cutset F of G. We de ne G-F to be the graph induced by the edges of E(G)􀀀 F,  (G􀀀 F) is the number of edges in the largest component of the graph induced by G-F and! (G 􀀀 F) is the number of components of G􀀀 F. A set F  E(G) is said to be a Te-set of G if Te(G) = jFj+ (G􀀀 F)! (G􀀀 F) Each component has at least one edge. In this paper we introduce a new invariant edge-tenacity, for graphs. it is another vulnerability measure. we present several properties and bounds on the edge-tenacity. we also compute the edge-tenacity of some classes of graphs.

In this study, the effect of rectangular finlets on the trailing edge noise of a flat plate in an incompressible turbulent boundary layer with Mach number 0. 06 has been studied numerically. The finlets are modeled upstream of the trailing edge of the flat plate with two spanwise spacing of 1. 5 and 0. 9 mm. Large-eddy simulation (LES) approach with Lund inflow generation model in open-source code of OpenFOAM has been used to simulate the turbulent boundary layer flow. Probe utility has been used for pressure and velocity data acquisitions. The finlets have increased the PSD of pressure fluctuations in the low to mid frequencies and decreased it at high frequencies between and downstream of the finlets. Also, the spanwise length scale of the pressure fluctuations increases, but the eddy convection velocity is reduced and their effects have been intensified by the reduction of the spanwise spacing. The mean velocity decreases, but the turbulence intensity increases downstream of the finlets. The reduction of the spanwise spacing of the finlets results in the formation of a stronger shear layer and the extension of the shear sheltering area downstream of the finlets. According to the results of the far-field noise prediction with Curle analogy, finlets with the spacing of 1. 5 mm have slightly reduced the noise about 0. 3 dB but the finlets with the spacing of 0. 9 mm have increased the trailing edge noise of the flat plate about 1. 0 dB.

In this paper, we study both concepts of geodetic dominating and edge geodetic dominating sets and derive some tight upper bounds on the edge geodetic and the edge geodetic domination numbers. We also obtain attainable upper bounds on the maximum number of elements in a partition of a vertex set of a connected graph into geodetic sets, edge geodetic sets, geodetic dominating sets and edge geodetic dominating sets, respectively.

In this paper, the transport properties of a phosphorene nanoribbon with zigzag edges are investigated. Although phosphorene is a two-dimensional structure with gaps, each zigzag edge of phosphorene nanoribbon acts like a one-dimensional quantum wire, so a nanoribbon with two edges is similar to two parallel quantum wires. We also show that by adding an impurity line between the upper and lower edges, we can create an impurity strip that can connect the upper edge to the lower edge. In other words, different inputs can be coupled to different outputs. To calculate coupling coefficients between inputs and outputs, we use the Lippmann-Schwinger formulation. The final results show that depending on the energy of the input state and the corresponding standing wave in the impurity band, the phenomenon of resonance or anti-resonance can be created in the dispersion between inputs and outputs. Besides the theoretical aspect of the proposed scheme presented in this article, it can be applied to make nanoswitches in practice.

For a coloring c of a graph G, the edge-di erence coloring sum and edge-sum coloring sum with respect to the coloring c are respectively Σ c D(G) = Σ jc(a) 􀀀 c(b)j and Σ s S(G) = Σ (c(a) + c(b)), where the summations are taken over all edges ab 2 E(G). The edge-di erence chromatic sum, denoted by Σ D(G), and the edge-sum chromatic sum, denoted by Σ S(G), are respectively the minimum possible values of Σ c D(G) and Σ c S(G), where the minimums are taken over all proper coloring of c. In this work, we study the edge-di erence chromatic sum and the edge-sum chromatic sum of graphs. In this regard, we present some necessary conditions for the existence of homomorphism between two graphs. Moreover, some upper and lower bounds for these parameters in terms of the fractional chromatic number are introduced as well.