The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and th...The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical展开更多
A numerical study based on the finite volume method has been performed to study the three-dimension natural convection in a parallelogrammic top side opened cavity filled nanofluid with partially heated square at the ...A numerical study based on the finite volume method has been performed to study the three-dimension natural convection in a parallelogrammic top side opened cavity filled nanofluid with partially heated square at the bottom side.Results are obtained for different governing parameters such as nanoparticle concentration (φ) from 0 to 0.05,inclination angle of the back and front walls (α) from 5° to 75°,Rayleigh number from 10^3 to 10^5,and length of heater changer from 0.1 to 1.The main finding from the obtained result showed that the inclination angle and nanoparticle volume fraction affect the flow structure and enhance the heat transfer.展开更多
Crack monitoring at the bolt hole edge is one of the important focuses of aircraft structural health monitoring.In this study,a novel eddy current sensing film based on a parallelogram coil array is developed to quant...Crack monitoring at the bolt hole edge is one of the important focuses of aircraft structural health monitoring.In this study,a novel eddy current sensing film based on a parallelogram coil array is developed to quantitatively monitor the crack characteristics near the bolt hole with fewer layers and coils,compared with the existing methods.The parallelogram coil array configuration is designed and optimized to improve the quantitative monitoring ability of the crack.A 3×3 parallelogram coil array is used to quantify the crack parameters of aluminum bolted joints.Finite element simulation and experiments show that the proposed parallelogram coil array could not only accurately and quantitatively identify the crack angle at the edge of the bolt hole,but also track the crack length along the radial direction of the bolt hole and the depth along the axial direction.展开更多
We are responsible for providing energy and food resources for our next generation.After more than 20 years of research,the author has confirmed that the VAWT with flip-up mechanism can maintain rotation without the b...We are responsible for providing energy and food resources for our next generation.After more than 20 years of research,the author has confirmed that the VAWT with flip-up mechanism can maintain rotation without the brake,even in strong winds.Experiments have shown that the triangularly coupled movable parallelogram buoyancy structure makes it easy to maintain the verticality of the wind turbine tower even under large waves.Furthermore,as a result of studying the connection between the HAWT(horizontal axis wind turbine)and the movable parallelogram buoyancy structure of the triangular connection,the feasibility was confirmed.The only way for all people in the world to secure energy and food fairly is to look for the remaining areas such as the high seas.The author would like to propose the use of the high seas to combat global hunger,which is likely to be a global problem in the future.展开更多
In this paper, the effect of thermal gradient on the vibration of parallelogram plate with linearly varying thickness in both direction having clamped boundary conditions on all the four edges is analyzed. Thermal eff...In this paper, the effect of thermal gradient on the vibration of parallelogram plate with linearly varying thickness in both direction having clamped boundary conditions on all the four edges is analyzed. Thermal effect on vibration of such plate has been taken as one-dimensional distribution in linear form only. An approximate but quiet convenient frequency equation is derived using Rayleigh-Ritz technique with a two-term deflection function. The frequencies corresponding to the first two modes of vibration of a clamped parallelogram plate have been computed for different values of aspect ratio, thermal gradient, taper constants and skew angle. The results have been presented in tabular forms. The results obtained in this study are reduced to that of unheated parallelogram plates of uniform thickness and have generally been compared with the published one.展开更多
Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</...Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</sub>(G,x) and Zg<sub>1</sub>(G) of the graph G are defined as Σ<sub>uv∈E(G)</sub>x<sup>(d<sub>u</sub>+d<sub>v</sub>)</sup> and Σ<sub>e=uv∈E(G)</sub>(d<sub>u</sub>+d<sub>v</sub>) respectively. Recently Ghorbani and Hosseinzadeh introduced the first Eccentric Zagreb index as Zg<sub>1</sub>*</sup>=Σ<sub>uv∈E(G)</sub>(ecc(v)+ecc(u)), that ecc(u) is the largest distance between u and any other vertex v of G. In this paper, we compute this new index (the first Eccentric Zagreb index or third Zagreb index) of an infinite family of linear Polycene parallelogram of benzenoid.展开更多
Two 3d-4f-5d heterometallic cluster-containing polyoxometalates,formulated as Na_(22){(SbW_(9)O_(33))_(4)[La_(3)W_(6)MO_(18)(H_(2)O)_(8)(CH_(3)COO)_(4)]_(2)}·nH_(2)O(abbreviated as La_(6)M_(2),M=Co/Mn)were synthe...Two 3d-4f-5d heterometallic cluster-containing polyoxometalates,formulated as Na_(22){(SbW_(9)O_(33))_(4)[La_(3)W_(6)MO_(18)(H_(2)O)_(8)(CH_(3)COO)_(4)]_(2)}·nH_(2)O(abbreviated as La_(6)M_(2),M=Co/Mn)were synthesized and structurally characterized.Single-crystal X-ray diffraction analyses reveal that the polyanions of La_(6)Co_(2)and La_(6)Mn_(2)consist of the uncommon 3d-4f-5d clusters{La_(6)W_(12)Co_(2)}and{La_(6)W_(12)Mn_(2)},which are encapsulated by four trilacunary Keggin tungstoantimonates to form the parallelogram-shaped title compounds.Additionally,the polyanions can be extended into a two-dimensional(2D)frame by the linkage of peripheral Na+ions.The inner space of the 2D layer was filled with water molecules and thus an H-bonded network was formed,which is expected to exhibit a fascinating proton conductivity.The study of water-assisted proton conduction demonstrated that La_(6)Co_(2)and La_(6)Mn_(2)were temperature-and humiditydependent proton conductors,respectively,and the proton conductivities could reach 1.3×10^(-2)and 2.3×10^(-2)S/cm at 65℃and 90%RH conditions.展开更多
文摘The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical
文摘A numerical study based on the finite volume method has been performed to study the three-dimension natural convection in a parallelogrammic top side opened cavity filled nanofluid with partially heated square at the bottom side.Results are obtained for different governing parameters such as nanoparticle concentration (φ) from 0 to 0.05,inclination angle of the back and front walls (α) from 5° to 75°,Rayleigh number from 10^3 to 10^5,and length of heater changer from 0.1 to 1.The main finding from the obtained result showed that the inclination angle and nanoparticle volume fraction affect the flow structure and enhance the heat transfer.
基金supported by the Natural Science Foundation of China(No.11902280)Aeronautical Science Fund(No.20200033068001)+1 种基金Innovation Fosundation for Young Scholar of Xiamen(No.3502Z20206042)the Fundamental Research Funds for the Central Universities(No.20720210049)。
文摘Crack monitoring at the bolt hole edge is one of the important focuses of aircraft structural health monitoring.In this study,a novel eddy current sensing film based on a parallelogram coil array is developed to quantitatively monitor the crack characteristics near the bolt hole with fewer layers and coils,compared with the existing methods.The parallelogram coil array configuration is designed and optimized to improve the quantitative monitoring ability of the crack.A 3×3 parallelogram coil array is used to quantify the crack parameters of aluminum bolted joints.Finite element simulation and experiments show that the proposed parallelogram coil array could not only accurately and quantitatively identify the crack angle at the edge of the bolt hole,but also track the crack length along the radial direction of the bolt hole and the depth along the axial direction.
文摘We are responsible for providing energy and food resources for our next generation.After more than 20 years of research,the author has confirmed that the VAWT with flip-up mechanism can maintain rotation without the brake,even in strong winds.Experiments have shown that the triangularly coupled movable parallelogram buoyancy structure makes it easy to maintain the verticality of the wind turbine tower even under large waves.Furthermore,as a result of studying the connection between the HAWT(horizontal axis wind turbine)and the movable parallelogram buoyancy structure of the triangular connection,the feasibility was confirmed.The only way for all people in the world to secure energy and food fairly is to look for the remaining areas such as the high seas.The author would like to propose the use of the high seas to combat global hunger,which is likely to be a global problem in the future.
文摘In this paper, the effect of thermal gradient on the vibration of parallelogram plate with linearly varying thickness in both direction having clamped boundary conditions on all the four edges is analyzed. Thermal effect on vibration of such plate has been taken as one-dimensional distribution in linear form only. An approximate but quiet convenient frequency equation is derived using Rayleigh-Ritz technique with a two-term deflection function. The frequencies corresponding to the first two modes of vibration of a clamped parallelogram plate have been computed for different values of aspect ratio, thermal gradient, taper constants and skew angle. The results have been presented in tabular forms. The results obtained in this study are reduced to that of unheated parallelogram plates of uniform thickness and have generally been compared with the published one.
文摘Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</sub>(G,x) and Zg<sub>1</sub>(G) of the graph G are defined as Σ<sub>uv∈E(G)</sub>x<sup>(d<sub>u</sub>+d<sub>v</sub>)</sup> and Σ<sub>e=uv∈E(G)</sub>(d<sub>u</sub>+d<sub>v</sub>) respectively. Recently Ghorbani and Hosseinzadeh introduced the first Eccentric Zagreb index as Zg<sub>1</sub>*</sup>=Σ<sub>uv∈E(G)</sub>(ecc(v)+ecc(u)), that ecc(u) is the largest distance between u and any other vertex v of G. In this paper, we compute this new index (the first Eccentric Zagreb index or third Zagreb index) of an infinite family of linear Polycene parallelogram of benzenoid.
基金supported by the National Natural Science Foundation of China(No.22071045)the Excellent Youth Science Fund Project of Henan Province(No.202300410042)+2 种基金the Natural Science Foundation of Henan Province(No.232300420372)Henan Universitythe State Key Laboratory of Physical Chemistry of the Solid Surface of Xiamen University。
文摘Two 3d-4f-5d heterometallic cluster-containing polyoxometalates,formulated as Na_(22){(SbW_(9)O_(33))_(4)[La_(3)W_(6)MO_(18)(H_(2)O)_(8)(CH_(3)COO)_(4)]_(2)}·nH_(2)O(abbreviated as La_(6)M_(2),M=Co/Mn)were synthesized and structurally characterized.Single-crystal X-ray diffraction analyses reveal that the polyanions of La_(6)Co_(2)and La_(6)Mn_(2)consist of the uncommon 3d-4f-5d clusters{La_(6)W_(12)Co_(2)}and{La_(6)W_(12)Mn_(2)},which are encapsulated by four trilacunary Keggin tungstoantimonates to form the parallelogram-shaped title compounds.Additionally,the polyanions can be extended into a two-dimensional(2D)frame by the linkage of peripheral Na+ions.The inner space of the 2D layer was filled with water molecules and thus an H-bonded network was formed,which is expected to exhibit a fascinating proton conductivity.The study of water-assisted proton conduction demonstrated that La_(6)Co_(2)and La_(6)Mn_(2)were temperature-and humiditydependent proton conductors,respectively,and the proton conductivities could reach 1.3×10^(-2)and 2.3×10^(-2)S/cm at 65℃and 90%RH conditions.
