scholarly journals Emittance Growth Caused by Electron Cloud Below the "Fast Tmci" Threshold: Numerical Noise or True Physics?

Author(s):  
E. Benedetto ◽  
D. Schulte ◽  
F. Zimmermann ◽  
G. Franchetti ◽  
K. Ohmi
Author(s):  
H. Rose

The scanning transmission electron microscope offers the possibility of utilizing inelastically scattered electrons. Use of these electrons in addition to the elastically scattered electrons should reduce the scanning time (dose) Which is necessary to keep the quantum noise below a certain level. Hence it should lower the radiation damage. For high resolution, Where the collection efficiency of elastically scattered electrons is small, the use of Inelastically scattered electrons should become more and more favorable because they can all be detected by means of a spectrometer. Unfortunately, the Inelastic scattering Is a non-localized interaction due to the electron-electron correlation, occurring predominantly at the circumference of the atomic electron cloud.


1998 ◽  
Vol 4 (1) ◽  
pp. 92-101
Author(s):  
A.S. Mazmanishvili ◽  
◽  
O.Ya. Rafalovich ◽  
◽  

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.


2012 ◽  
Vol 40 (2) ◽  
pp. 83-107 ◽  
Author(s):  
Zhao Li ◽  
Ziran R. Li ◽  
Yuanming M. Xia

ABSTRACT A detailed tire-rolling model (185/75R14), using the implicit to explicit FEA solving strategy, was constructed to provide a reliable, dynamic simulation with several modeling features, including mesh, material modeling, and a solving strategy that could contribute to the consideration of the serious numerical noises. High-quality hexahedral meshes of tread blocks were obtained with a combined mapping method. The actual rubber distributing and nonlinear, stress-strain relationship of the rubber and bilinear elastic reinforcement were modeled for realism. In addition, a tread-rubber friction model obtained from the Laboratory Abrasion and Skid Tester (LAT 100) was applied to simulate the interaction of the tire with the road. The force and moment (F&) behaviors of tire cornering when subjected to a slip-angle sweep of −10 to 10° were studied with that model. To demonstrate the efficiency of the proposed simulation, the computed F&M were compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering F&M agreed well with the experimental results, so the footprint shape and contact pressure distribution of several cornering conditions were investigated. Furthermore, the longitudinal forces in response to braking/driving torque application in a slip-ratio range of −100% to 100% were computed. The proposed FEA solution confines the numerical noise within a smaller range and can serve as a valid tool in tire design.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4292
Author(s):  
Kirill Kabalyk ◽  
Andrzej Jaeschke ◽  
Grzegorz Liśkiewicz ◽  
Michał Kulak ◽  
Tomasz Szydłowski ◽  
...  

The article describes an assessment of possible changes in constant fatigue life of a medium flow-coefficient centrifugal compressor impeller subject to operation at close-to-surge point. Some aspects of duct acoustics are additionally analyzed. The experimental measurements at partial load are presented and are primarily used for validation of unidirectionally coupled fluid-structural numerical model. The model is based on unsteady finite-volume fluid-flow simulations and on finite-element transient structural analysis. The validation is followed by the model implementation to replicate the industry-scale loads with reasonably higher rotational speed and suction pressure. The approach demonstrates satisfactory accuracy in prediction of stage performance and unsteady flow field in vaneless diffuser. The latter is deduced from signal analysis relying on continuous wavelet transformations. On the other hand, it is found that the aerodynamic incidence losses at close-to-surge point are underpredicted. The structural simulation generates considerable amounts of numerical noise, which has to be separated prior to evaluation of fluid-induced dynamic strain. The main source of disturbance is defined as a stationary region of static pressure drop caused by flow contraction at volute tongue and leading to first engine-order excitation in rotating frame of reference. Eventually, it is concluded that the amplitude of excitation is too low to lead to any additional fatigue.


2021 ◽  
Author(s):  
Wenjing Yang ◽  
Yanhong Dong ◽  
Hongjian Sun ◽  
Xiaoyan Li

The synthesis and characterization of Fe, Co and Ni complexes supported by silylene ligands in recent ten years are summarized. Due to the decrease of electron cloud density on Si...


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