Linear and nonlinear analysis of submicron n+nn+ diodes for microwave generators

1992 ◽  
Vol 19 (1-4) ◽  
pp. 417-420 ◽  
Author(s):  
V. Gruzhinskis ◽  
E. Starikov ◽  
P. Shiktorov ◽  
L. Reggiani ◽  
L. Varani ◽  
...  
2021 ◽  
Vol 11 (8) ◽  
pp. 3425
Author(s):  
Marco Zucca ◽  
Nicola Longarini ◽  
Marco Simoncelli ◽  
Aly Mousaad Aly

The paper presents a proposed framework to optimize the tuned mass damper (TMD) design, useful for seismic improvement of slender masonry structures. A historical masonry chimney located in northern Italy was considered to illustrate the proposed TMD design procedure and to evaluate the seismic performance of the system. The optimization process was subdivided into two fundamental phases. In the first phase, the main TMD parameters were defined starting from the dynamic behavior of the chimney by finite element modeling (FEM). A series of linear time-history analyses were carried out to point out the structural improvements in terms of top displacement, base shear, and bending moment. In the second phase, masonry's nonlinear behavior was considered, and a fiber model of the chimney was implemented. Pushover analyses were performed to obtain the capacity curve of the structure and to evaluate the performance of the TMD. The results of the linear and nonlinear analysis reveal the effectiveness of the proposed TMD design procedure for slender masonry structures.


2006 ◽  
Vol 17 (01) ◽  
pp. 65-73 ◽  
Author(s):  
SHIRO SAWADA

The optimal velocity model which depends not only on the headway but also on the relative velocity is analyzed in detail. We investigate the effect of considering the relative velocity based on the linear and nonlinear analysis of the model. The linear stability analysis shows that the improvement in the stability of the traffic flow is obtained by taking into account the relative velocity. From the nonlinear analysis, the relative velocity dependence of the propagating kink solution for traffic jam is obtained. The relation between the headway and the velocity and the fundamental diagram are examined by numerical simulation. We find that the results by the linear and nonlinear analysis of the model are in good agreement with the numerical results.


2021 ◽  
Author(s):  
SeHyuk Park ◽  
Hamad Alnuaimi ◽  
Anna Hayes ◽  
Madison Sitkiewicz ◽  
Umar Amjad ◽  
...  

Abstract Guided acoustic wave based techniques have been found to be very effective for damage detection, and both quantitative and qualitative characterization of materials. In this research, guided acoustic wave techniques are used for porosity evaluation of additively manufactured materials. A metal 3D printer, Concept Laser Mlab 200 R Cusing™, is used to manufacture 316L additively manufactured (AM) stainless steel specimens. Two levels of porosity are investigated in this study, which was controlled by a suitable combination of scan speed and laser power. The sample with lower level of porosity is obtained with a low scanning speed. Lead Zirconate Titanate (PZT) transducers are used to generate guided acoustic waves. The signal is excited and propagated through the specimens in a single sided transmission mode setup. Signal processing of the recorded signals for damage analysis involves both linear and nonlinear analyses. Linear ultrasonic parameters such as the time-of-flight and magnitude of the propagating waves are recorded. The nonlinear ultrasonic parameter, the Sideband Peak Count Index (SPC-I) is obtained by a newly developed nonlinear analysis technique. Results obtained for both specimens are analyzed and compared using both linear and nonlinear ultrasonic techniques. Finally, the effectiveness of SPC-I technique in monitoring porosity levels in AM specimens is discussed.


Author(s):  
Мaria S. Barabash ◽  
Maryna A. Romashkina

The paper deals with technique of simulation for buildings at maintenance stage with account of changes in structural model during reconstruction. The authours suggest algorithm for linear and nonlinear analysis of structures in LIRA-SAPR program with account of erection process. Generation of design models for reconstructed buildings are illustrated with real examples from design practice (reconstruction of 3-storey office building with overstorey; reconstruction of 5-storey hostel with built-in nonresidential premises when floor slabs are changed; reconstruction of building with account of defects that were detected and strengthening that was made; reconstruction of 9-storey residential building where gaz was exploded, with account of defects that were detected and strengthening that was made).


2000 ◽  
Vol 28 (6) ◽  
pp. 2051-2057 ◽  
Author(s):  
Daniel Toweill ◽  
Karen Sonnenthal ◽  
Brent Kimberly ◽  
Susanna Lai ◽  
Brahm Goldstein

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