Fabrication of Ag-nanosheet-assembled hollow tubular array and their SERS effect

2019 ◽  
Vol 772 ◽  
pp. 663-668 ◽  
Author(s):  
Haibao Zhang ◽  
Jingjing Wang ◽  
Guang Li ◽  
Lin Chen ◽  
Hua Wang ◽  
...  
Keyword(s):  
Tubular Array

scholarly journals CONSTRUCTAL DESIGN OF A TUBULAR ARRAY SUBJECTED TO FORCED CONVECTION

2015 ◽  
Vol 14 (1) ◽  
pp. 16
Author(s):  
V. A. Pedrotti ◽  
J. A. Souza ◽  
E. D. Dos Santos ◽  
L. A. Isoldi
Keyword(s):  
Thermal Performance ◽  
Mesh Generation ◽  
Constructal Theory ◽  
Forced Flow ◽  
Constructal Design ◽  
Fluent Software ◽  
Energy Equations ◽  
Volume Method ◽  
Study Setting ◽  
Tubular Array

In this work a tubular array (four tubes) subjected to a transverse forced flow is analyzed in terms of thermal performance. Taking into account that there are two main assembles usually used in heat exchanger equipment (aligned and staggered), and that there exist an uncountable number of possible assembles for an array of tubes, present work proposes to use the Constructal Theory to build an optimized assemble. The distance between tubes (p), and the region where tubes can be positioned are the geometric constraint of the problem. Four values for p were considered: p = 1.25D (tube diameter), p = 1.5D, p = 2D, p is free (no restriction). Fluid flow is considered bi-dimensional, incompressible and laminar with ReD = 10 and Pr = 0.71. Mass, momentum and energy equations were solved by the Finite Volume Method (FVM) using FLUENT software. Geometry creation and mesh generation were performed with GMSH software while VISIT software was used for the post processing. Results have shown that imposing no restriction to tube positioning do not necessarily lead to best system thermal performance. In this particular study, setting p = 2D has resulted in best thermal performance.

Highly tunable acoustic metamaterials based on a resonant tubular array

2012 ◽  
Vol 86 (18) ◽  
Author(s):  
K. J. B. Lee ◽  
Myoung Ki Jung ◽  
Sam H. Lee
Keyword(s):  
Acoustic Metamaterials ◽  
Tubular Array

A novel tubular hydrogen-bond pattern in a new diazaphosphole oxide: a combination of X-ray crystallography and theoretical study of hydrogen bonds

2017 ◽  
Vol 73 (7) ◽  
pp. 508-516 ◽  
Author(s):  
Fahimeh Sabbaghi ◽  
Mehrdad Pourayoubi ◽  
Abolghasem Farhadipour ◽  
Nazila Ghorbanian ◽  
Pavel V. Andreev
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Coupling Constant ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Hydrogen Bond Pattern ◽  
Orbital Analysis ◽  
Tubular Array ◽  
Hydrogen Bonded

In the structure of 2-(4-chloroanilino)-1,3,2λ4-diazaphosphol-2-one, C12H11ClN3OP, each molecule is connected with four neighbouring molecules through (N—H)2...O hydrogen bonds. These hydrogen bonds form a tubular arrangement along the [001] direction built from R 3 3(12) and R 4 3(14) hydrogen-bond ring motifs, combined with a C(4) chain motif. The hole constructed in the tubular architecture includes a 12-atom arrangement (three P, three N, three O and three H atoms) belonging to three adjacent molecules hydrogen bonded to each other. One of the N—H groups of the diazaphosphole ring, not co-operating in classical hydrogen bonding, takes part in an N—H...π interaction. This interaction occurs within the tubular array and does not change the dimension of the hydrogen-bond pattern. The energies of the N—H...O and N—H...π hydrogen bonds were studied by NBO (natural bond orbital) analysis, using the experimental hydrogen-bonded cluster of molecules as the input file for the chemical calculations. In the 1H NMR experiment, the nitrogen-bound proton of the diazaphosphole ring has a high value of 17.2 Hz for the 2 J H–P coupling constant.

The energy-absorbing characteristics of tubular sandwich structures

2021 ◽  
pp. 109963622110204
Author(s):  
HZ Jishi ◽  
RA Alia ◽  
WJ Cantwell
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Small Diameter ◽  
Areal Density ◽  
External Energy ◽  
Composite Tubes ◽  
Longitudinal Splitting ◽  
Energy Absorbing ◽  
Tubular Array ◽  
Tubular Arrays

The energy-absorbing response of sandwich structures with exceptionally high levels of energy absorption is investigated. The sandwich panels are produced by fixing small composite tubes onto metal facings with surface features that reflect the internal geometry of the tubing. Small diameter tubes are employed to manufacture the cores, since it is well established that the specific energy absorption (SEA) characteristics of a composite tube increase as the inner dimension (diameter or wall-to-wall) to thickness ratio decreases. Tests have been undertaken on tubular arrays based on both circular and square composite tubes. The effect of varying the areal density of the tubular array within the core was investigated by systematically increasing the number of tubes from one to nine. An examination of the composites during the crushing process indicated that all of the tubes failed in a splaying process, involving significant fracturing of fibers and longitudinal splitting. The measured values of SEA remained relatively constant in most cases as the areal density of the tubular arrangement was increased, suggesting that cores could readily be designed to absorb known levels of applied external energy. Arrays based on circular tubes offered higher energy-absorbing characteristics than their square counterparts, with values in excess of 100 kJ/kg being recorded in some cases. It is believed that these tubular sandwich structures offer potential for use in components that are subjected to extreme dynamic loading, such as those associated with impact and blast.

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