Triangular Sheet Research Articles

Triangular graphene nanosheets, structures with extraordinary bending behavior.

Sometimes, manipulating the geometry or creating a defect can help the engineering of the nanostructured properties, such as increasing the frequency sensitivity of graphene nanosheets as a mass sensor by changing the geometry of the structure in a triangular shape and also by creating a vacancy or making nanodiodes in a triangular shape, which restricts the flow of heat in one direction and expands it in another direction. Then, the mechanical properties of the triangular geometry of graphene nanosheets have an excellent value for future devices. The results of the molecular dynamics study can illustrate the mechanical properties of graphene sheets well, which is particularly important. In this study, using molecular dynamics (MD) simulation, the bending stiffness of triangular graphene sheets was investigated to present a broader view of engineering applications of graphene sheets. Analyzing stress-displacement results of triangular graphene sheets in both zigzag and armchair directions under bending load reveals the effect of the directions of sheets on their bending stiffness. Also, comparing the bending stiffness of pristine and defective sheets showed that bending stiffness was decreased when an atom was removed from the middle of a sheet and made a single vacancy defected sheet. Obtained results suggest that triangular graphene nanosheets with higher bending stiffness, compared to rectangular sheets with the same number of atoms, are better for applications requiring higher bending properties, such as nanoelectromechanical devices. The reported results of this work provide an overall viewpoint concerning the geometry and defect effects on the graphene nanosheets' mechanical properties. The bending stiffness of triangular sheets was 20 and 10 times that of intrinsic and defective rectangular sheets, respectively.

Triangular BiVO4-Bi2O3 ultrathin sheet composites for enhancement of photoelectrochemical and photocatalytic performance

Our research unveils the synthesis of BiVO4-Bi2O3 triangular sheet composites, demonstrating their impact on charge separation ability under visible light irradiation. We found that composites with optimal BiVO4 content exhibit enhanced photocurrent density, reduced interfacial resistance, prolonged carrier life, increased surface active sites, improved charge transfer efficiency, and carrier concentration. The proposed Z-scheme mechanism appears to govern this composite system’s efficient separation of photogenerated carriers. These findings underscore the potential of BiVO4-Bi2O3 triangular sheet composites in adjusting photosensitivity and enhancing the photocatalytic ability of β-Bi2O3 triangular sheets, opening up new avenues for research in the application of the sustainable environment field.

Cost-effective horn antennas; from E-plane sectionalized to octagonal shapes

ABSTRACT In this paper, low-cost methods of improving horn antennas are studied based on the recently introduced E-plane sectionalized rectangular horn antennas. In the beginning, application of E-plane sectionalizing of the rectangular horn antennas on open-boundary E-plane sectoral horn antennas is reexamined and a simple method for obtaining high gain and low sidelobe levels (SLLs) is introduced. Subsequently, effects of removing the conductive sheets from the modified E-plane sectionalized horn antenna are studied and a simple horn antenna with octagonal aperture is obtained with slightly reduced efficiency. Finally, an ultra-low-cost method of improving simple rectangular horn antennas is introduced based on this study. The purpose is to compensate the destructive effects of high SLLs of reference antennas in the antenna measurements, since a common reference antenna type is the rectangular horn antenna, which has high SLLs on the E-plane. In particular, efficiency improvement and SLL reduction of rectangular horn antennas are achieved by adding only four triangular conductive sheets to construct octagonal horn antennas.

Computation of connection-based Zagreb indices in chain graphs and triangular sheets

Graph theory is a mathematical framework that can be used to model and analyze complex networks. Topology plays a key role in determining the compatibility of chemical graphs. Topological indices have been widely applied in a wide range of domains, such as chemistry, biological activity prediction, environmental risk assessment, and drug design. These indices can predict aqueous solubility, dipole moment, viscosity, boiling degree, refractive index, toxicity, and surface tension, among other physicochemical characteristics. Topological descriptors also assist us in the quantitative analysis and comparison of molecules by simplifying complicated molecular information. In this paper, we have computed the first Zagreb connection index ZC 1, the second Zagreb connection index ZC 2, and the first modified Zagreb connection index Z C 1 * . Further, a few recently introduced Zagreb connection indices like atom-bond connectivity, geomatric-arithmatic, and hyper-Zagreb connection indices are also calculated for the melem chain MC(m), the borophene chain B 36 ( m ) , and the boron triangular sheet BTS(m, n). Our goal is to comprehend the molecular connections between these substances. Through the study of several mathematical methods, we discovered intriguing relationships and patterns within their structures. The primary objective of our research is to learn more about these compounds and the relationship between their molecular structures and properties. Every chemical, as we have seen, has distinct properties. The ability to predict the behavior of these molecules under different conditions might open up new research avenues and practical applications.

Vibrations and buckling of triangular graphene sheet in polymer matrix

AbstractThe work is devoted to the study of vibrations and buckling of a graphene sheet (GS) with the shape of a right triangle, and embedded in a nonlinear polymer matrix. The research is based on the nonlocal elasticity theory and the application of the Bubnov‐Galerkin method. Due to the influence of the polymer surrounding, the study of vibrations is reduced to the analysis of a nonlinear cubic ordinary differential equation considering small‐scale effects. The nonlocal buckling problem for the triangular GS under in‐plane uniform compression is investigated including the finding of critical buckling load and the post‐buckling behaviour determined by the nonlinear medium effect.

Connection Number-based Multiplicative Zagreb Indices of Chemical Structures

Abstract: A topological index is a quantitative measure of molecular structure and connection. It also estimates the toxicological, structural, biological, and physicochemical characteristics of a chemical molecule. The use of nano-structured graphs in the study of chemistry is very extensive. Melem, one of the most significant tri−s−triazine compounds, is a nucleophilic reagent that may be employed in reactions with derivatives of phthalic acid. Materials with borophene nanostructures are also exploited in cross-disciplinary research. In comparison to carbon hexagonal nanotubes, boron triangular nanotubes are thought to be a superior conductor. The goal of computing the multiplicative Zagreb connection indices for Chemical graphs is to understand the complexity, connectedness, and chemical activity of molecules. Information is useful in a number of applications, including drug design, chemical synthesis, and property prediction. In this paper, we compute the first, second, third, fourth, and fifth multiplicative Zagreb connection indices (ZCIs) of the melem chain MC(s), the borophene chain B36(s), and the boron triangular sheet BTS(m,s).

GENERALIZED REDEFINED ZAGREB INDEX ON SOME NANOSTRUCTURES

Chemical graph theory has become a significant part of the research. Topological indices are numerical descriptors used to determine physico-chemical properties of chemical compounds. In this work, the generalized redefined Zagreb index is defined. This index is applied on several topological indices viz., redefined Zagreb indices (ReZG1(G), ReZG2(G), ReZG3(G)), sum-connectivity Zagreb index (SCI(G)), hyper Zagreb index (HM(G)), harmonic index (H(G)), arithmetic-geometric index (AGI(G)), SK index (SK(G)) and SK1 index (SK1(G)). The above said indices are calculated for aromatic compounds such as boron triangular sheet, borophene chain and melem chain nanostructures. The obtained results are useful in understanding the behaviour of compounds under the study.

Connection-based modified Zagreb indices of Boron triangular sheet BTS(m,n)

A topological index is a parameter from a molecular graph that predicts physicochemical properties or biological activities, characterised by the topology of molecular structure. Mathematician Harry Wiener created the Wiener index, one of the first and most widely used topological indices, in 1947 while trying to solve the problem of determining the boiling points of n-alkanes. In 1972, mathematician Ivan Gutman introduced the concept of degree-based topological indices. Then he proposed a series of topological indices based on the atomic degrees, such as the first and second Zagreb indices and Zagreb connection indices. In this study, we obtained modified second, third, and fourth Zagreb connections as well as modified first, second, and third multiplicative Zagreb connection indices for the Boron triangular sheet .

Flexible one-dimensional yarn-like Ni-Zn battery: micron-nano hierarchical-structure array, high energy density and excellent capacity retention

Many researches are devoted to design the wearable fibrous energy storage devices with miniaturization in order to satisfy the large demand of power for portable wearable electronics. As a kind of flexible battery, one-dimensional yarn-like nickel-zinc (Ni-Zn) battery has a lot of disadvantages such as low energy density and poor power density. Significantly, metal–organic framework (MOF) material provides an opportunity to solve the preceding shortcomings due to its porous structure, excellent specific surface area and multi-functionalization. In this study, the nickel cobalt layered double hydroxides (NiCo LDHs) with triangular micro sheet array and nano sheet structure is designed and prepared on silver coated nylon fibers (SCNF) as the flexibly fibrous Ni-Zn battery cathodes (SCNF@Ni@MOF@NiCo LDHs yarn electrode), which have high specific surface area and super structure stability even during bending of the yarn. Therefore, the cathodes have abundant active sites, excellent electron conduction and fast ion diffusion. The assembled aqueous Ni-Zn battery is featured with suitable capacitance (342 mAh/g at 7.6 A/g), appropriate energy density (572.5 Wh/g at 2.59 W g−1) and superior stability (55 % after 5000 cycles). In addition, the obtained one-dimensional yarn-like Ni-Zn battery has excellent flexibility and high capacity retention (90 % after 1000 bends and over 80 % after different deformation ways such as bend, squeeze and twist). These fascinating results demonstrate that the SCNF@Ni@MOF@NiCo LDHs yarn electrode have great application potential in wearable energy storage devices.

Detection of brown adipose tissue in rats with acute cold stimulation using quantitative susceptibility mapping.

Detection of brown adipose tissue in rats with acute cold stimulation using quantitative susceptibility mapping.

Experimental and Numerical Investigation on the Transient Cavitating Flows in a Mixed Flow Pump With Different Number of Blades at Startup

Abstract The objective of this paper is to experimentally and numerically investigate the transient cavitation flow during the startup process of mixed flow pump with emphasis on studying the influence of blade numbers. The transient cavitation simulation was studied based on the improved SST k–ω turbulence model and the Zwart cavitation model. Firstly, in order to obtain the relationship between transient flow rate and the variation of rotational speed at startup, a theoretical analysis based on the fast transients of centrifugal pump was first applied to mixed flow pump and was verified by the current experiment study. Subsequently, the influence of blade number on the cavitation flow in the startup was studied. It is found that the transient cavitation could be classified into four stages regardless of the number of blades: no cavitation stage, the cavitation growth stage, the cavitation reduction stage and the cavitation stabilization stage. However, the blade number does have an impact on the spatial-temporal evolution of cavitation. More specifically, when the blade number increases, the initial cavitation appeared lately, the coverage area of the triangular cavitation cloud and sheet cavitation both decreased, and the increase in blade number has a better inhibitory effect on the sheet cavitation at the cavitation growth stage, and can make sheet cavitation disappear more quickly at the cavitation reduction stage.

A Path Planning Method Based on Robot Automatic Grinding of Drills

This paper proposes a path planning method for grinding excess material after PDC bit repair using industrial robots. Firstly, a 3D scanning instrument is used to obtain point cloud data of the bit to be ground, secondly, this data are imported into Geomagic Studio for processing to obtain the triangular sheet file of the area to be ground. Finally, the software based on MATLAB is used to process the file and calculate the motion path of the robot end-effector. The generated path is imported into ROS for simulation. By comparing the generated path with the grinding area, it was verified that the generated path could be used in actual operation.

Complex viscosity of graphene suspensions

Atomically thin flat sheets of carbon, called graphene, afford interesting opportunities to study the role of orientation in suspensions. In this work, we use general rigid bead-rod theory to arrive at general expressions from first principles for the complex viscosity of graphene suspensions. General rigid bead-rod theory relies entirely on suspension orientation to explain the elasticity of the liquid. We obtain analytical expressions for the complex viscosity of triangular and hexagonal graphene sheets of arbitrary size. We find good agreement with new complex viscosity measurements.

Experimental Investigation of Drawbead Effect on Springback in Profile of Double Circular, Rectangular and Triangular Bending Sheet Metal Forming Processes

Springback is considered as one of the most common problems in metal forming processes, which poses an inaccuracy of product angle during assembling of parts. The estimation of the springback is difficult to predict for formed parts since it depends on many factors such as the mechanical properties, the sheet thickness, and the die angle. In this work, an experimental investigation of drawbead for different material thicknesses and the use of different lubricants such as grease, oil and wax have been studied and analyzed. Samples of aluminum specimens with 120 mm length, 30 mm width and thickness of 0.5, 0.7 and 0.8 mm were selected in this study. Design and manufacturing of double bending die with profile of Circular, Rectangular, and Triangular have been applied firstly without drawbead and then with drawbead. The results showed that in a given profile configuration, the springback reduced with existing the drawbead

Structural Evolution of Boron Clusters on Ag(111) Surfaces - From Atomic Chains to Triangular Sheets with Hexagonal Holes.

Unlike graphene and other 2D materials, borophene is 2D polymorphic with diverse hexagonal holes (HHs)-triangles ratios and the concentrations of HHs are highly substrate dependent. Here, we systematically explored the evolution of boron cluster on Ag(111) surface, BN @Ag(111) (N=1∼36), to understand the nucleation of 2D boron sheet on metal surface. Our calculation showed that, with the size increasing, the structures of most stable BN clusters undergo an evolution from compact triangular lattice, such as double-chains or triple-chains, to the ones with mixed triangular-hexagonal lattices. The first single-HH appears at N=12 and the first double-HH appears at N=27. The stability of large BN clusters with mixed structures is derived from the charge transfer between triangular lattice and the HHs, as well as between the substrates and the BN clusters. Our results provide a deep understanding on the formation of small boron clusters in the initial nucleation stage of borophene growth.

Cylindrical Focused Laser Differential Interferometer

A novel configuration of focused laser differential interferometry (FLDI) was developed, simulated, and tested. The new configuration is referred to as cylindrical FLDI or CFLDI. Using cylindrical lenses in place of standard lenses changes the three-dimensional shape of the focusing beam from a cone shape for FLDI to a triangular sheet for CFLDI, allowing for probing of flat-plate boundary layers closer to the wall. The beam propagation and interference pattern were modeled to determine the transfer functions for one-dimensional sinusoidal disturbances of varying wavelength () and varying spanwise thickness () of the tested area. CFLDI was employed to measure the density perturbations in supersonic blowdown wind tunnel SBR-50 at the University of Notre Dame with the test section width of 0.076.2 m. It was determined that the CFLDI system sufficiently filtered the sidewall boundary layers to measure the spectra of density fluctuations in a plane wall boundary layer. However, accurate measurements of the density disturbances in the freestream flow must account for the contribution of the sidewall boundary layers. This serves as an initial validation of the CFLDI maintaining spatial filtering similar to a regular FLDI.

Three-port terahertz circulator with multi-layer triangular graphene-based post

This article proposes a novel three-port circulator with a triangular graphene-based post for the THz region. This new circulator is formed by three 120° symmetrical metal-based waveguides. The anisotropic feature for circulation is provided by magnetically-biased graphene in the triangular post. The DC magnetic bias is applied in the z-direction. The magnetized, triangular graphene sheet supports hybrid TM-TE plasmons. To realize the proposed circulator, the structure has been simulated in COMSOL software. In our simulation results, isolation of -40 dB with a transmission loss of -3.5 dB is obtained at the central frequency of 5 THz for a specific design. The bandwidth of the simulated circulator is reported 7.25 % with respect to the isolation level of -15 dB. It has been shown that the scattering parameters of the proposed circulator can be changed by altering the chemical potential of the graphene and DC magnetic bias, which makes this circulator a tunable device to be utilized in various plasmonic systems.

On Knowledge Discovery and Representations of Molecular Structures Using Topological Indices

Abstract The main purpose of a topological index is to encode a chemical structure by a number. A topological index is a graph invariant, which decribes the topology of the graph and remains constant under a graph automorphism. Topological indices play a wide role in the study of QSAR (quantitative structure-activity relationship) and QSPR (quantitative structure-property relationship). Topological indices are implemented to judge the bioactivity of chemical compounds. In this article, we compute the ABC (atom-bond connectivity); ABC 4 (fourth version of ABC), GA (geometric arithmetic) and GA 5 (fifth version of GA) indices of some networks sheet. These networks include: octonano window sheet; equilateral triangular tetra sheet; rectangular sheet; and rectangular tetra sheet networks.

Structure, stability and bonding of the leapfrog B24 0 ,±1,±2.

Two new structural motifs of the B24 clusters are constructed by use of the leapfrog transformation. The resulting leapfrog B24 has either a bowl shape with a square vacancy or a quasi-planar 2D close-packed triangular boron sheet. The neutral and ionic forms of the latter are found to be more stable than their homologous leapfrog bowl clusters, with the exception of the dicationic B24 +2 . While the leapfrog isomer is less stable than the tubular double ring in the neutral state, it becomes competitive in some ionic states. The nucleus independent chemical shift, electron localization function, ring current maps and the electronic structure of leapfrog B24 clusters reveal them to behave as aromatics.

Nanoparticle mass detection by single-layer triangular graphene sheets, the extraordinary geometry for detection of nanoparticles

Present study peruses the vibrational behavior of triangular graphene sheets based on nano-mechanical graphene sensors. To this end, pristine and defected triangular graphene sheets in two directions, zigzag and armchair, have been simulated in molecular dynamic environment, and also the static response of sheets alone and with attached particles has been studied. By extracting the natural frequency using frequency decomposition method for sheets alone and with attached particles on them, as well as for defected sheets, their vibrational characteristics are determined and the frequency sensitivity is obtained for the number of different particles added. Two analyzes of mechanical tensile properties and vibrational properties have been performed to verify the accuracy of the method used on square and rectangular graphene sheets. Graphene sheet behavior under tensile test compared with other literature of molecular dynamic results and also the vibrational behavior of the square graphene sheet is obtained from the present method compared with the results of one of the improved theories of continuum mechanics. The comparisons illustrate the accuracy and applicability of the method is used. Finally, by examining the frequency sensitivity of each sheet, it is shown that equilateral triangular geometry in zigzag direction with the highest frequency sensitivity will result in sensors with higher sensitivity.