Influence of the coordination number and volume of a primitive cell on the vibration frequency of an iron atom during a polymorphic transition

2020 ◽  
Vol 1679 ◽  
pp. 042068
Author(s):  
Stepan A Yurchenko
Keyword(s):  
Coordination Number ◽  
Vibration Frequency ◽  
Iron Atom ◽  
Polymorphic Transition ◽  
Primitive Cell

Analysis of crystallographic and structural data of polymeric iron-alkaline metal complexes

2011 ◽  
Vol 34 (5-6) ◽  
pp. 93-126
Author(s):  
Milan Melnik ◽  
Markku Rafael Sundberg ◽  
Rolf Uggla
Keyword(s):  
Coordination Number ◽  
Iron Atom ◽  
Structural Parameters ◽  
Structural Data ◽  
Oxidation States ◽  
Alkaline Metal ◽  
Coordination Numbers ◽  
Metal Atoms ◽  
Polymeric Chains ◽  
Group 1

Abstract The present review covers almost 100 polymeric MFe (M=Li, Na, K, Rb, and Cs) compounds. The metal atoms of group 1 as partners with iron atom build up complex polymeric chains. The iron atoms are found in the oxidation states 0, +2, and +3, of which the oxidation state +3 prevails. The coordination number of the iron atom ranges from 2 to 10 (sandwiched). The coordination sphere about the main group 1 metals varies, ranging from tetrahedral to mostly trigonal bipyramid. There are also higher coordination numbers involved, namely, from 6 to 10. The most common ligand atoms are oxygen and nitrogen. There are three compounds displaying distortion isomerism. Several relationships between structural parameters are found and discussed.

Bond-length distributions for ions bonded to oxygen: Results for the lanthanides and actinides and discussion of the f-block contraction

2017 ◽  
Author(s):  
Olivier Charles Gagné
Keyword(s):  
Bond Length ◽  
Coordination Number ◽  
Lanthanide Ions ◽  
Lanthanide Contraction ◽  
Trivalent Lanthanide ◽  
Actinide Ions

Bond-length distributions have been examined for eighty-four configurations of the lanthanide ions and twenty-two configurations of the actinide ions bonded to oxygen. The lanthanide contraction for the trivalent lanthanide ions bonded to O<sup>2-</sup> is shown to vary as a function of coordination number and to diminish in scale with increasing coordination number.

Conceptual design and numerical studies of active flow control aerofoil based on shape-memory alloy and macro fibre composites

2021 ◽  
Vol 125 (1287) ◽  
pp. 830-846
Author(s):  
W. Zhang ◽  
X.T. Nie ◽  
X.Y. Gao ◽  
W.H. Chen
Keyword(s):  
Shape Memory Alloy ◽  
Flow Control ◽  
Shape Memory ◽  
Vibration Frequency ◽  
Active Flow Control ◽  
Flow Characteristics ◽  
Hybrid Design ◽  
Numerical Studies ◽  
Fibre Composites ◽  
Active Flow

ABSTRACTActive flow control for aerofoils has been proven to be an effective way to improve the aerodynamic performance of aircraft. A conceptual hybrid design with surfaces embedded with Shape-Memory Alloy (SMA) and trailing Macro Fibre Composites (MFC) is proposed to implement active flow control for aerofoils. A Computational Fluid Dynamics (CFD) model has been built to explore the feasibility and potential performance of the proposed conceptual hybrid design. Accordingly, numerical analysis is carried out to investigate the unsteady flow characteristics by dynamic morphing rather than using classical static simulations and complicated coupling. The results show that camber growth by SMA action could cause an evident rise of Cl and Cd in the take-off/landing phases when the Angle-of-Attack (AoA) is less than 10°. The transient tail vibration behaviour in the cruise period when using MFC actuators is studied over wide ranges of frequency, AoA and vibration amplitude. The buffet frequency is locked in by the vibration frequency, and a decrease of 1.66–2.32% in Cd can be achieved by using a proper vibration frequency and amplitude.

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