scholarly journals Strength of Superelastic NiTi Velcro-Like Fasteners

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 909
Author(s):  
David Vokoun ◽  
Jan Pilch ◽  
Lukáš Kadeřávek ◽  
Petr Šittner
Keyword(s):  
Gaussian Distribution ◽  
Room Temperature ◽  
Detachment Force ◽  
Linear Dependency ◽  
Non Linear ◽  
Hook Geometry ◽  
Niti Wires ◽  
The Given ◽  
Tension Strength

Velcro hook-and-loop fasteners invented more than 70 years ago are examples of the mechanism inspired by the tiny hooks found on the surface of burs of a plant commonly known as burdock. Several years ago, a novel Velcro-like fastener made of two arrays of hook-shaped thin NiTi wires was developed. Unique features of such fasteners, such as high thermally-tunable strength, fair force–stroke reproducibility, forceless contact or silent release, all derive from the superelasticity of the NiTi micro-wires. Recently, it was noticed that the presented fastener design allowed for a prediction of the number of active hooks. In this continuing study, the tension strength of the fastener was simulated as a function of hook density. Based on statistics, the model showed non-linear dependency of the number of interlocked hooks, N, on the hook density, m (N = round (0.21 m + 0.0035 m2 − 6.6)), for the simple hook pairs and the given hook geometry. The dependence of detachment force on stroke was simulated based on the Gaussian distribution of unhooking of individual hook connections along the stroke. The strength of the studied NiTi hook fasteners depended on hook density approximately linearly. The highest strength per cm2 reached at room temperature was 10.5 Ncm−2 for a density of m = 240 hooks/cm2.

CLASS OF BOOLEAN FUNCTIONS CONSTRUCTED USING SIGNIFICANT BITS OF LINEAR RECURRENCES OVER THE RING ℤ2n

2019 ◽  
Vol 6 (2) ◽  
pp. 90-94
Author(s):  
Hernandez Piloto Daniel Humberto
Keyword(s):  
Linear Function ◽  
Boolean Functions ◽  
Hamming Distance ◽  
Linear Recurrences ◽  
Maximum Period ◽  
Non Linear ◽  
The Given ◽  
Class Of Functions

In this work a class of functions is studied, which are built with the help of significant bits sequences on the ring ℤ2n. This class is built with use of a function ψ: ℤ2n → ℤ2. In public literature there are works in which ψ is a linear function. Here we will use a non-linear ψ function for this set. It is known that the period of a polynomial F in the ring ℤ2n is equal to T(mod 2)2α, where α∈ , n01- . The polynomials for which it is true that T(F) = T(F mod 2), in other words α = 0, are called marked polynomials. For our class we are going to use a polynomial with a maximum period as the characteristic polyomial. In the present work we show the bounds of the given class: non-linearity, the weight of the functions, the Hamming distance between functions. The Hamming distance between these functions and functions of other known classes is also given.

Pressure dependent ultrasonic properties of hcp hafnium metal

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ramanshu P. Singh ◽  
Shakti Yadav ◽  
Giridhar Mishra ◽  
Devraj Singh
Keyword(s):  
Elastic Constants ◽  
Pressure Range ◽  
Room Temperature ◽  
Ultrasonic Attenuation ◽  
Coupling Constants ◽  
Ultrasonic Properties ◽  
Acoustic Coupling ◽  
Third Order Elastic Constants ◽  
The Stability ◽  
The Given

Abstract The elastic and ultrasonic properties have been evaluated at room temperature between the pressure 0.6 and 10.4 GPa for hexagonal closed packed (hcp) hafnium (Hf) metal. The Lennard-Jones potential model has been used to compute the second and third order elastic constants for Hf. The elastic constants have been utilized to calculate the mechanical constants such as Young’s modulus, bulk modulus, shear modulus, Poisson’s ratio, and Zener anisotropy factor for finding the stability and durability of hcp hafnium metal within the chosen pressure range. The second order elastic constants were also used to compute the ultrasonic velocities along unique axis at different angles for the given pressure range. Further thermophysical properties such as specific heat per unit volume and energy density have been estimated at different pressures. Additionally, ultrasonic Grüneisen parameters and acoustic coupling constants have been found out at room temperature. Finally, the ultrasonic attenuation due to phonon–phonon interaction and thermoelastic mechanisms has been investigated for the chosen hafnium metal. The obtained results have been discussed in correlation with available findings for similar types of hcp metals.

Lipophilic-hydrophilic properties and retention of phenylhydrazonopropanedinitriles by biological systems

1985 ◽  
Vol 50 (2) ◽  
pp. 538-550 ◽  
Author(s):  
Ernest Šturdík ◽  
Štefan Baláž ◽  
Marián Antalík ◽  
Pavol Sulo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Regression Analysis ◽  
Linear Dependence ◽  
Partition Coefficients ◽  
Linear Regression Analysis ◽  
Buffer System ◽  
Ph Values ◽  
Mycobacterium Phlei ◽  
Non Linear ◽  
The Given

Apparent partition coefficients in n-octanol-buffer system, solubility in the buffers, and retention by mitochondria from rat liver, by Mycobacterium phlei and by Saccharomyces cerevisiae (after 10 min incubation) have been characterized for 13 arylsubstituted phenylhydrazonopropanedinitrile derivatives. Regression analysis has shown linear dependence of logarithms of the apparent partition coefficients on the published π parameters characterizing lipophilicity of the substituents. The apparent partition coefficients are inversely proportional to the solubility of the phenylhydrazonopropanedinitriles. The retention by the biosystems studied increases linearly with increasing lipophilicity, being independent of reactivity of the phenylhydrazonopropanedinitriles. The non-linear dependence of concentration of the phenylhydrazonopropanedinitriles remaining in the medium on the lipophilicity indicates that a lipophilic-hydrophilic equilibrium is established in the given time. The retained amount of the derivatives tested decreases with increasing pH values. The dependences are Z-shaped and have been described by the equations derived from the model presented by application of non-linear regression analysis.

Vibrational analysis of the low resolution absorption spectra of BrClCS and Br2CS

1988 ◽  
Vol 66 (3) ◽  
pp. 359-366 ◽  
Author(s):  
B. Simard ◽  
R. P. Steer ◽  
R. H. Judge ◽  
D. C. Moule
Keyword(s):  
Absorption Spectra ◽  
Room Temperature ◽  
Vibrational Analysis ◽  
Vibrational Frequencies ◽  
Low Resolution ◽  
Barrier Heights ◽  
Vibrational Levels ◽  
Out Of Plane ◽  
The Given

The [Formula: see text] absorption spectra of BrClCS and Br2CS have been photographed under low resolution at room temperature. The electronic origins of BrClCS and Br2CS have been placed at 17116 and 16859 cm−1, respectively. Vibronic analyses show that the molecules are non-planar in their ā states. By fitting quadratic–Gaussian and quadratic–quartic double-minimum potentials to the observed vibrational levels of the out-of-plane manifolds, the equilibrium out-of-plane angles and the barrier heights to molecular inversion have been estimated to be 25 ± 1 deg and 541 ± 10 cm−1 for BrClCS, and 17.5 ± 1 deg and 524 ± 10 cm−1 for Br2CS. In the case of BrClCS, all six ā state vibrational frequencies have been obtained. In the case of Br2CS, only modes 1 (C—S stretch), 2 (symmetric C—Br stretch), 3 (in-plane Br—C—Br scissor), and 4 (out-of-plane bend) are active in the spectrum. Comparisons with other tetraatomic thiocarbonyls support the given assignments.

Confinement driven effects in a room temperature ferroelectric liquid crystal: X-ray, linear and non-linear dielectric investigations

2013 ◽  
Vol 86 (4) ◽  
pp. 323-338 ◽  
Author(s):  
M. Vijay Kumar ◽  
S. Krishna Prasad ◽  
D.S. Shankar Rao ◽  
E.P. Pozhidaev
Keyword(s):  
Liquid Crystal ◽  
Room Temperature ◽  
Ferroelectric Liquid Crystal ◽  
X Ray ◽  
Non Linear

Uniformly almost periodic solutions of non-linear differential equations of the second order I. General exposition

1955 ◽  
Vol 51 (4) ◽  
pp. 604-613
Author(s):  
Chike Obi
Keyword(s):  
Differential Equation ◽  
Differential Equations ◽  
Second Order ◽  
Linear Differential Equations ◽  
Almost Periodic ◽  
Non Linear ◽  
Independent Variable ◽  
Linear Differential ◽  
The Given ◽  
Analytical Expressions

1·1. A general problem in the theory of non-linear differential equations of the second order is: Given a non-linear differential equation of the second order uniformly almost periodic (u.a.p.) in the independent variable and with certain disposable constants (parameters), to find: (i) the non-trivial relations between these parameters such that the given differential equation has a non-periodic u.a.p. solution; (ii) the number of periodic and non-periodic u.a.p. solutions which correspond to each such relation; and (iii) explicit analytical expressions for the u.a.p. solutions when they exist.

scholarly journals IMPROVED METHODS OF CALCULATING SPANS OF CITY BRIDGES DURING THE RECONSTRUCTION TAKING INTO ACCOUNT STRUCTURAL AND TECHNOLOGICAL FACTORS

2015 ◽  
Vol 1 (158) ◽  
Author(s):  
Alexey Lobiak ◽  
Armaіs Oganesyan ◽  
Maxim Kovalyov
Keyword(s):  
Computer Simulation ◽  
Concrete Slabs ◽  
Technological Factors ◽  
Linear Dependency ◽  
Reconstruction Scheme ◽  
Non Linear ◽  
Three Stages ◽  
Improved Methods

An improvement of the methods of computer simulation of beam spans bridge city during the reconstruction scheme of the device for concrete slabs invoice. The calculations provide consistent construction of structures in three stages with non-linear dependency of concrete deformation and creep.

scholarly journals Experimental study of liquid evaporation from a surface of gel mixture

2019 ◽  
Vol 196 ◽  
pp. 00030
Author(s):  
Andrey Vyazmin ◽  
Dmitry Khramtsov ◽  
Boris Pokusaev ◽  
Dmitry Nekrasov ◽  
Nikolay Zakharov
Keyword(s):  
Experimental Study ◽  
Linear Dependency ◽  
Non Linear ◽  
Liquid Evaporation

Experimental study of liquid evaporation from gel mixture surface was performed. Gels based on agarose and starch were studied. Dependencies of liquid evaporation from time were obtained for mixtures of agarose and starch. A non-linear dependency of evaporation speed was observed for all sets of mixtures. It was shown that presence of starch inhibits the process of liquid evaporation.

scholarly journals Tunable exciton-polaritons emerging from WS2 monolayer excitons in a photonic lattice at room temperature

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
L. Lackner ◽  
M. Dusel ◽  
O. A. Egorov ◽  
B. Han ◽  
H. Knopf ◽  
...  
Keyword(s):  
Room Temperature ◽  
Optical Cavity ◽  
Research Strategy ◽  
Central Research ◽  
Ambient Conditions ◽  
Spectral Window ◽  
Strongly Coupled ◽  
Experimental Implementation ◽  
Exciton Polaritons ◽  
Non Linear

AbstractEngineering non-linear hybrid light-matter states in tailored lattices is a central research strategy for the simulation of complex Hamiltonians. Excitons in atomically thin crystals are an ideal active medium for such purposes, since they couple strongly with light and bear the potential to harness giant non-linearities and interactions while presenting a simple sample-processing and room temperature operability. We demonstrate lattice polaritons, based on an open, high-quality optical cavity, with an imprinted photonic lattice strongly coupled to excitons in a WS2 monolayer. We experimentally observe the emergence of the canonical band-structure of particles in a one-dimensional lattice at room temperature, and demonstrate frequency reconfigurability over a spectral window exceeding 85 meV, as well as the systematic variation of the nearest-neighbour coupling, reflected by a tunability in the bandwidth of the p-band polaritons by 7 meV. The technology presented in this work is a critical demonstration towards reconfigurable photonic emulators operated with non-linear photonic fluids, offering a simple experimental implementation and working at ambient conditions.

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