scholarly journals Interpretation of the bacterial growth process based on the analysis of the speckle field generated by calibrated scattering media

2020 ◽  
Vol 28 (19) ◽  
pp. 28648 ◽  
Author(s):  
Hadi Loutfi ◽  
Fabrice Pellen ◽  
Bernard Le Jeune ◽  
Roger Lteif ◽  
Mireille Kallassy ◽  
...  
2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Abdelmounaim Khallouq ◽  
Asma Karama ◽  
Mohamed Abyad

Abstract This paper presents the problem of actuator fault estimation and fault-tolerant control (FTC) of a biological process using Takagi–Sugeno fuzzy formulation. The goal is to ensure the desired outputs tracking even if the time-varying actuator faults occur. We propose to use a proportional multi-integral (PMI) observer to estimate both the time-varying actuator faults and the state of system. The reconstructed faults are used to reconfigure the nominal controller. As a nominal control, we use a fuzzy linear quadratic integral (LQI) law. To ensure the global asymptotic convergence of the PMI observer and to improve the compensation speed of faults, we propose to use the multiple Lyapunov function by introducing a convergence rate. Sufficient conditions in terms of linear matrix inequalities (LMIs) are developed. The obtained results show that, the proposed approach is successfully applied to the problem of actuator fault-tolerant control of a bacterial growth process.


2015 ◽  
Vol 08 (02) ◽  
pp. 1550007 ◽  
Author(s):  
Qiang Yang ◽  
Xinzhu Sang ◽  
Daxiong Xu

Focusing light though scattering media beyond the ballistic regime is a challenging task in biomedical optical imaging. This challenge can be overcome by wavefront shaping technique, in which a time-reversed (TR) wavefront of scattered light is generated to suppress the scattering. In previous TR optical focusing experiments, a phase-only spatial light modulator (SLM) has been typically used to control the wavefront of incident light. Unfortunately, although the phase information is reconstructed by the phase-only SLM, the amplitude information is lost, resulting in decreased peak-to-background ratio (PBR) of optical focusing in the TR wavefront reconstruction. A new method of TR optical focusing through scattering media is proposed here, which numerically reconstructs the full phase and amplitude of a simulated scattered light field by using a single phase-only SLM. Simulation results and the proposed optical setup show that the time-reversal of a fully developed speckle field can be digitally implemented with both phase and amplitude recovery, affording a way to improve the performance of light focusing through scattering media.


Author(s):  
J.A. Eades ◽  
E. Grünbaum

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.


Author(s):  
T. Sato ◽  
S. Kitamura ◽  
T. Sueyoshl ◽  
M. Iwatukl ◽  
C. Nielsen

Recently, the growth process and relaxation process of crystalline structures were studied by observing a SI nano-pyramid which was built on a Si surface with a UHV-STM. A UHV-STM (JEOL JSTM-4000×V) was used for studying a heated specimen, and the specimen was kept at high temperature during observation. In this study, the nano-fabrication technique utilizing the electromigration effect between the STM tip and the specimen was applied. We observed Si atoms migrated towords the tip on a high temperature Si surface.Clean surfaces of Si(lll)7×7 and Si(001)2×l were prepared In the UHV-STM at a temperature of approximately 600 °C. A Si nano-pyramid was built on the Si surface at a tunneling current of l0nA and a specimen bias voltage of approximately 0V in both polarities. During the formation of the pyramid, Images could not be observed because the tip was stopped on the sample. After the formation was completed, the pyramid Image was observed with the same tip. After Imaging was started again, the relaxation process of the pyramid started due to thermal effect.


Author(s):  
H. L. Tsai ◽  
J. W. Lee

Growth of GaAs on Si using epitaxial techniques has been receiving considerable attention for its potential application in device fabrication. However, because of the 4% lattice misfit between GaAs and Si, defect generation at the GaAs/Si interface and its propagation to the top portion of the GaAs film occur during the growth process. The performance of a device fabricated in the GaAs-on-Si film can be degraded because of the presence of these defects. This paper describes a HREM study of the effects of both the substrate surface quality and postannealing on the defect propagation and elimination.The silicon substrates used for this work were 3-4 degrees off [100] orientation. GaAs was grown on the silicon substrate by molecular beam epitaxy (MBE).


1990 ◽  
Vol 17 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Maher M. Anous ◽  
Haskell Gruber
Keyword(s):  

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