scholarly journals On the Static Pull-in of Tilting Actuation in Hybrid Levitation Micro-actuator: Theory and Experiment

Author(s):  
Kirill V. Poletkin

This work presents the results of the experimental and theoretical study of the static pull-in of tilting actuation executed by a hybrid levitation micro-actuator (HLMA) based on the combination of inductive levitation and electrostatic actuation. A semi-analytical model to study such the pull-in phenomenon is developed, for the first time, as a result of using the qualitative technique based on the Lagrangian approach to analyze inductive contactless suspensions presented in work and a recent progress in the calculation of mutual inductance and force between two circular filaments. The obtained non-linear model, accounting for two degrees of freedom of the actuator, allows us to predict accurately the static pull-in displacement and voltage. The results of modelling were verified experimentally and agree well with measurements.

Actuators ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 256
Author(s):  
Kirill Poletkin

This work presents the results of the experimental and theoretical study of the static pull-in of tilting actuation executed by a hybrid levitation micro-actuator (HLMA) based on the combination of inductive levitation and electrostatic actuation. A semi-analytical model to study such a pull-in phenomenon is developed, for the first time, as a result of using the qualitative technique based on the Lagrangian approach to analyze inductive contactless suspensions and a recent progress in the calculation of mutual inductance and force between two circular filaments. The obtained non-linear model, accounting for two degrees of freedom of the actuator, allows us to predict accurately the static pull-in displacement and voltage. The results of modeling were verified experimentally and agree well with measurements.


Author(s):  
Sara Fucini ◽  
Sergio Scopetta ◽  
Michele Viviani

An interesting breakthrough in understanding the elusive inner content of nuclear systems in terms of partonic degrees of freedom is represented by deeply virtual Compton scattering processes. In such a way, tomographic view of nuclei and bound nucleons in coordinate space could be achieved for the first time. Moreover, nowadays experimental results for such a process considering ^44He targets recently released at Jefferson Lab are available. In this talk, the recent results of our rigorous Impulse Approximation for DVCS off ^44He, in terms of state-of-the-art models of the nuclear spectral function and of the parton structure of the bound proton, able to explain present data, has been shown.


2021 ◽  
Vol 5 (5) ◽  
pp. 119
Author(s):  
Stelios K. Georgantzinos ◽  
Georgios I. Giannopoulos ◽  
Panteleimon A. Bakalis

This paper aims to establish six-dimensional (6D) printing as a new branch of additive manufacturing investigating its benefits, advantages as well as possible limitations concerning the design and manufacturing of effective smart structures. The concept of 6D printing, to the authors’ best knowledge, is introduced for the first time. The new method combines the four-dimensional (4D) and five-dimensional (5D) printing techniques. This means that the printing process is going to use five degrees of freedom for creating the final object while the final produced material component will be a smart/intelligent one (i.e., will be capable of changing its shape or properties due to its interaction with an environmental stimulus). A 6D printed structure can be stronger and more effective than a corresponding 4D printed structure, can be manufactured using less material, can perform movements by being exposed to an external stimulus through an interaction mechanism, and it may learn how to reconfigure itself suitably, based on predictions via mathematical modeling and simulations.


2021 ◽  
Vol 23 (4) ◽  
pp. 2605-2621
Author(s):  
M. Goussougli ◽  
B. Sirjean ◽  
P.-A. Glaude ◽  
R. Fournet

A theoretical study of the thermal decomposition of β-1,4-xylan, a model polymer of hemicelluloses, is proposed for the first time.


Author(s):  
X. Lachenal ◽  
P. M. Weaver ◽  
S. Daynes

Conventional shape-changing engineering structures use discrete parts articulated around a number of linkages. Each part carries the loads, and the articulations provide the degrees of freedom of the system, leading to heavy and complex mechanisms. Consequently, there has been increased interest in morphing structures over the past decade owing to their potential to combine the conflicting requirements of strength, flexibility and low mass. This article presents a novel type of morphing structure capable of large deformations, simply consisting of two pre-stressed flanges joined to introduce two stable configurations. The bistability is analysed through a simple analytical model, predicting the positions of the stable and unstable states for different design parameters and material properties. Good correlation is found between experimental results, finite-element modelling and predictions from the analytical model for one particular example. A wide range of design parameters and material properties is also analytically investigated, yielding a remarkable structure with zero stiffness along the twisting axis.


2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Justine Yasappan ◽  
Ángela Jiménez-Casas ◽  
Mario Castro

Fluids subject to thermal gradients produce complex behaviors that arise from the competition with gravitational effects. Although such sort of systems have been widely studied in the literature for simple (Newtonian) fluids, the behavior of viscoelastic fluids has not been explored thus far. We present a theoretical study of the dynamics of a Maxwell viscoelastic fluid in a closed-loop thermosyphon. This sort of fluid presents elastic-like behavior and memory effects. We study the asymptotic properties of the fluid inside the thermosyphon and the exact equations of motion in the inertial manifold that characterizes the asymptotic behavior. We derive, for the first time, the mathematical derivations of the motion of a viscoelastic fluid in the interior of a closed-loop thermosyphon under the effects of natural convection and a given external temperature gradient.


Author(s):  
J. Espinosa-Garcia ◽  
Jose Carlos Corchado

For the theoretical study of the title reaction, an analytical full-dimensional potential energy surface named PES-2021 was developed for the first time, by fitting high-level explicitly-correlated ab initio data. This...


Author(s):  
Л. Х. Пастушкова ◽  
Д. Н. Каширина ◽  
А. Г. Гончарова ◽  
Н. Б. Захарова ◽  
Е. С. Тийс ◽  
...  

Впервые описаны белки, достоверно увеличивающиеся и уменьшающиеся в моче с возрастом в интервале 20-60 лет. Охарактеризованы комбинации белков, связанных с изменением иммунных процессов, нарушением реологии крови, в том числе риском коагулопатии, противоопухолевых защитных механизмов, инсулинового сигнального пути, с изменением характеристик клеточного деления и качества новообразованной ткани. Таким образом, возрастная динамика основных процессов запускает каскад реакций, проявляющихся в замыкании «патологических биохимических кругов», которые формируют предпосылки к развитию заболеваний и, с течением времени, клинические проявления. For the first time proteins are described, reliably increasing and decreasing in urine with age in the range of 20 to 60 years. The combinations of proteins associated with changes in immune processes, violation of blood reology, including the risk of coagulopathy, anticancer defense mechanisms, insulin signaling pathway, changes in cell characteristics are characterized division and quality of the newly formed fabric. Thus, the age dynamics of the main processes triggers a cascade of reactions manifested in the closure of «pathological biochemical circles» that form the prerequisites for the development of diseases and, over time, clinical manifestations.


Author(s):  
Wei Liu ◽  
Yunbo Yuan ◽  
Tao He ◽  
Donghua Wang

Considering the effect of teeth surface sliding friction, free vibration of two-stage planetary gears (TPG) is studied theoretically for the first time. The lateral-torsional coupling dynamic model and equation are established with three degrees of freedom: two translations and one rotation. The change rule of natural frequency is discussed with the case of first stage planetary gear’s number 4 and second stage planetary gear’s number 3, 4 and 5. Afterwards three vibration modes are summarized by calculating the free vibration. In order to understand the behavior of friction, the effect of friction on natural frequencies is analyzed for the case of considering friction and not considering friction. Furthermore, the ‘self-coupling’ phenomenon is obtained from the vibration of center component of TPG Meanwhile, the ‘mutual coupling’ is obtained between the first-stage planetary gear (FPG) and the second-stage planetary gear (SPG).


2017 ◽  
Vol 19 (37) ◽  
pp. 25298-25308
Author(s):  
Andreas Erlebach ◽  
Katrin Thieme ◽  
Marek Sierka ◽  
Christian Rüssel

Solid solutions of SiO2and B2O3in Li2O·2SiO2are synthesized and characterized for the first time by calculations and experiments.


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