scholarly journals Long-Time Behavior of Surface Properties of Microstructures Fabricated by Multiphoton Lithography

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3285
Author(s):  
Mateusz Dudziak ◽  
Ievgeniia Topolniak ◽  
Dorothee Silbernagl ◽  
Korinna Altmann ◽  
Heinz Sturm

The multiphoton lithography (MPL) technique represents the future of 3D microprinting, enabling the production of complex microscale objects with high precision. Although the MPL fabrication parameters are widely evaluated and discussed, not much attention has been given to the microscopic properties of 3D objects with respect to their surface properties and time-dependent stability. These properties are of crucial importance when it comes to the safe and durable use of these structures in biomedical applications. In this work, we investigate the surface properties of the MPL-produced SZ2080 polymeric microstructures with regard to the physical aging processes during the post-production stage. The influence of aging on the polymeric microstructures was investigated by means of Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). As a result, a time-dependent change in Young’s Modulus, plastic deformation, and adhesion and their correlation to the development in chemical composition of the surface of MPL-microstructures are evaluated. The results presented here are valuable for the application of MPL-fabricated 3D objects in general, but especially in medical technology as they give detailed information of the physical and chemical time-dependent dynamic behavior of MPL-printed surfaces and thus their suitability and performance in biological systems.

2019 ◽  
Vol 17 (1) ◽  
pp. 89-103
Author(s):  
Qiaozhen Ma ◽  
Jing Wang ◽  
Tingting Liu

Abstract In this article, we consider the long-time behavior of solutions for the wave equation with nonlinear damping and linear memory. Within the theory of process on time-dependent spaces, we verify the process is asymptotically compact by using the contractive functions method, and then obtain the existence of the time-dependent attractor in $\begin{array}{} H^{1}_0({\it\Omega})\times L^{2}({\it\Omega})\times L^{2}_{\mu}(\mathbb{R}^{+};H^{1}_0({\it\Omega})) \end{array}$.


2021 ◽  
pp. 1-17
Author(s):  
Penghui Zhang ◽  
Lu Yang

In this paper, we study the long-time behavior of the following plate equation ε ( t ) u t t + g ( u t ) + Δ 2 u + λ u + f ( u ) = h , where the coefficient ε depends explicitly on time, the nonlinear damping and the nonlinearity both have critical growths.


2003 ◽  
Vol 2003 (43) ◽  
pp. 2747-2758 ◽  
Author(s):  
Ray Redheffer ◽  
Richard R. Vance

We give conditions under which two solutionsxandyof the Kolmogorov equationx˙=xf(t,x)satisfylimy(t)/x(t)=1ast→∞. This conclusion is important for two reasons: it shows that the long-time behavior of the population is independent of the initial condition and it applies to ecological systems in which the coefficients are time dependent. Our first application is to an equation of Weissing and Huisman for growth and competition in a light gradient. Our second application is to a nonautonomous generalization of the Turner-Bradley-Kirk-Pruitt equation, which even before generalization, includes several problems of ecological interest.


1988 ◽  
Vol 5 (2) ◽  
pp. 311
Author(s):  
Mozaffar Partowmah

The 14th Annual Conferknce of the Association of Muslim Scientistsand Engineers (ASME) was held during the weekend of qufur 2628,1409/0ctober 7-9, 1988, at the Islamic Center of North America in Plainfield,Indiana. Papers presented at the Conference dealt with a variety of subjectsranging from agriculture and health sciences to car manufacturing tips,computers, industrial, civil and electronic engineering, as well as resourcemanagement and organizational behavior.Members of the AMSS (Association of Muslim Social Scientists) whoattended the AMSE Conference, participated in the sessions with undividedattention. Dr. AbdulHamid AbuSulayman, the AMSS President, in his banquetspeech, stressed the need for an active AMSE that will eventually attracta more sizable number of Muslims in North America and coordinate theirscientific efforts for their common benefit.In a session entitled “Technology Transfer,” the Japanese and Koreanapproaches were contrasted with the Muslim world approach. A highlightof the Conference was the announcement of the A1 Khwarazmi Award thatthe AMSE will award annually to a distinguished Muslim scientist or engineer.The first Al Khwarazmi Award went to Dr. M.A.K. Lodhi of Texas A&MUniversity in appreciation of his continuous support for Muslim studentsand his long-time involvement in the AMSE in addition to his scientific interestand achievements in nuclear physics and field theory.The Best Student Paper Award went to the following: 1) Abdullah M.Elramsisi of Rochester Hill, Michigan for his paper “On Model-based ImageRestoration and Performance Evaluation;” and 2) Khatib Rajab of Morgantown,West Virginia for his paper on “Agricultural Research Needs and Prioritiesin Zanzibar as perceived by Administrators and Extension Workers.”Copies of all of the presented papers were distributed at the Conferenceand will be ppblished in the conference proceedings. Preprints and reprintsmay be obtained by writing to the AMSE office at P.O. Box 38, Plainfield,Indianna, 46168 ...


2021 ◽  
Vol 8 (1) ◽  
pp. 27-45
Author(s):  
M. M. Freitas ◽  
M. J. Dos Santos ◽  
A. J. A. Ramos ◽  
M. S. Vinhote ◽  
M. L. Santos

Abstract In this paper, we study the long-time behavior of a nonlinear coupled system of wave equations with damping terms and subjected to small perturbations of autonomous external forces. Using the recent approach by Chueshov and Lasiecka in [21], we prove that this dynamical system is quasi-stable by establishing a quasistability estimate, as consequence, the existence of global and exponential attractors is proved. Finally, we investigate the upper and lower semicontinuity of global attractors under autonomous perturbations.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1117
Author(s):  
Bin Li ◽  
Zhikang Jiang ◽  
Jie Chen

Computing the sparse fast Fourier transform (sFFT) has emerged as a critical topic for a long time because of its high efficiency and wide practicability. More than twenty different sFFT algorithms compute discrete Fourier transform (DFT) by their unique methods so far. In order to use them properly, the urgent topic of great concern is how to analyze and evaluate the performance of these algorithms in theory and practice. This paper mainly discusses the technology and performance of sFFT algorithms using the aliasing filter. In the first part, the paper introduces the three frameworks: the one-shot framework based on the compressed sensing (CS) solver, the peeling framework based on the bipartite graph and the iterative framework based on the binary tree search. Then, we obtain the conclusion of the performance of six corresponding algorithms: the sFFT-DT1.0, sFFT-DT2.0, sFFT-DT3.0, FFAST, R-FFAST, and DSFFT algorithms in theory. In the second part, we make two categories of experiments for computing the signals of different SNRs, different lengths, and different sparsities by a standard testing platform and record the run time, the percentage of the signal sampled, and the L0, L1, and L2 errors both in the exactly sparse case and the general sparse case. The results of these performance analyses are our guide to optimize these algorithms and use them selectively.


2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Xiaopeng Zhao

AbstractIn this paper, we study the long time behavior of solution for the initial-boundary value problem of convective Cahn–Hilliard equation in a 2D case. We show that the equation has a global attractor in $H^{4}(\Omega )$ H 4 ( Ω ) when the initial value belongs to $H^{1}(\Omega )$ H 1 ( Ω ) .


2021 ◽  
pp. 1-27
Author(s):  
Ahmad Makki ◽  
Alain Miranville ◽  
Madalina Petcu

In this article, we are interested in the study of the well-posedness as well as of the long time behavior, in terms of finite-dimensional attractors, of a coupled Allen–Cahn/Cahn–Hilliard system associated with dynamic boundary conditions. In particular, we prove the existence of the global attractor with finite fractal dimension.


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