scholarly journals FMR Damping in Thin Films with Exchange Bias

2021 ◽  
Vol 7 (5) ◽  
pp. 70
Author(s):  
Nikolay G. Chechenin ◽  
Irina O. Dzhun ◽  
Georgy V. Babaytsev ◽  
Mikhail G. Kozin ◽  
Alexey V. Makunin ◽  
...  
Keyword(s):  
Exchange Bias ◽  
High Frequency ◽  
High Speed ◽  
Bias Field ◽  
Sample Surface ◽  
Interface Roughness ◽  
Stray Field ◽  
Angular Dispersion ◽  
The Difference ◽  
Frequency Properties

Ferromagnetic resonance (FMR) linewidth (LW) is a tool for studying the high frequency properties of magnetic materials for their application in high-speed devices. Here, we investigate different mechanisms which determine FMR damping in bilayer ferromagnetic/antiferromagnetic (F/AF and AF/F) exchange bias systems. Variations of FMR LW with the thickness and deposition order of the F and AF layers were studied, as well as their correlation with the exchange bias field and roughness of the sample surface. We observed much larger LW in AF/F structures compared with F/AF samples. It was found that neither the exchange bias nor surface/interface roughness in the samples could explain the difference in LW for F/AF and AF/F samples. Instead, the different underlayer microstructure influenced the grainsize, leading to different angular dispersion of magnetization and different internal stray field in F-layers, promoting a different intensity of magnon scattering and FMR damping in F/AF and AF/F samples.

scholarly journals Analysis of positioning error and its impact on high frequency properties of differential signal coupler

2015 ◽  
Vol 63 (2) ◽  
pp. 549-553
Author(s):  
M. Zmuda ◽  
S. Szczepański ◽  
S. Kozieł
Keyword(s):  
Data Transmission ◽  
High Frequency ◽  
High Speed ◽  
Design Methodology ◽  
Concept Design ◽  
Differential Signal ◽  
Chip Data ◽  
High Speed Data ◽  
Frequency Properties ◽  
Speed Data Transmission

Abstract This paper presents the analysis of the effect of differential signal coupler positioning accuracy on its high frequency performance parameters for contact-less high speed chip-to-chip data transmission on PCB application. Our considerations are continuation of the previous works on differential signal coupler concept, design methodology and analysis for high speed data transmission monitoring. The theoretical analysis of possible coupler positioning innaccuracies is extended for representative design cases by simulations carried out using EM simulator. The results reported here confirm that the concept of contactless monitoring of high speed chip-to-chip data transmission in a pair of coupled microstrip lines is of practically usefulness without applying the expensive and precise positioning system

High-Speed SiGe BiCMOS Technologies and Circuits

2017 ◽  
Vol 26 (01n02) ◽  
pp. 1740002 ◽  
Author(s):  
A. Mai ◽  
I. Garcia Lopez ◽  
P. Rito ◽  
R. Nagulapalli ◽  
A. Awny ◽  
...  
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Heterojunction Bipolar Transistor ◽  
Sige Hbt ◽  
Wave Radar ◽  
Bicmos Technology ◽  
Sige Bicmos ◽  
Additional Process ◽  
The Difference ◽  
Oscillation Frequencies

This work reports on the development of SiGe-BiCMOS technologies for mm-wave and THz high frequency applications. We present state-of-the-art performances for different SiGe heterojunction bipolar transistor (SiGe-HBT) developments as well as the evolution of complex BiCMOS technologies. With respect to different technology generations of high-speed SiGe-BiCMOS processes at IHP we discuss selected device modifications of the SiGe-HBT to achieve high frequency performances of a complex BiCMOS technology towards the 0.5 THz regime. We show the difference of high-frequency performance difference with respect to maximum achievable transit frequencies fT and oscillation frequencies fmax in comparison to RF-CMOS technologies and depict the required increase of additional process effort for the HBT-module integration for a 0.5 THz SiGe-BiCMOS technology. Moreover different high speed circuits are presented like broadband ICs for optical communication, high frequency circuits for wireless communication at 60 and 240 GHz, mm-wave radar circuits at 60 and 120 GHz as well as THz circuits operating at 245 GHz and 500 GHz for spectroscopic applications. All reviewed circuit examples are based on the discussed 130nm-SiGe-BiCMOS technologies and show their potential for a broad range of high-speed applications.

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

scholarly journals Prognostic Assessment of the Performance Parameters for the Industrial Diesel Engines Operated with Microalgae Oil

2021 ◽  
Vol 13 (11) ◽  
pp. 6482
Author(s):  
Sergejus Lebedevas ◽  
Laurencas Raslavičius
Keyword(s):  
Energy Efficiency ◽  
Diesel Engine ◽  
High Speed ◽  
Performance Parameters ◽  
Prognostic Assessment ◽  
High Speed Diesel ◽  
Microalgae Oil ◽  
The Difference ◽  
Smoke Opacity ◽  
Efficiency Indicators

A study conducted on the high-speed diesel engine (bore/stroke: 79.5/95.5 mm; 66 kW) running with microalgae oil (MAO100) and diesel fuel (D100) showed that, based on Wibe parameters (m and φz), the difference in numerical values of combustion characteristics was ~10% and, in turn, resulted in close energy efficiency indicators (ηi) for both fuels and the possibility to enhance the NOx-smoke opacity trade-off. A comparative analysis by mathematical modeling of energy and traction characteristics for the universal multi-purpose diesel engine CAT 3512B HB-SC (1200 kW, 1800 min−1) confirmed the earlier assumption: at the regimes of external speed characteristics, the difference in Pme and ηi for MAO100 and D100 did not exceeded 0.7–2.0% and 2–4%, respectively. With the refinement and development of the interim concept, the model led to the prognostic evaluation of the suitability of MAO100 as fuel for the FPT Industrial Cursor 13 engine (353 kW, 6-cylinders, common-rail) family. For the selected value of the indicated efficiency ηi = 0.48–0.49, two different combinations of φz and m parameters (φz = 60–70 degCA, m = 0.5 and φz = 60 degCA, m = 1) may be practically realized to achieve the desirable level of maximum combustion pressure Pmax = 130–150 bar (at α~2.0). When switching from diesel to MAO100, it is expected that the ηi will drop by 2–3%, however, an existing reserve in Pmax that comprises 5–7% will open up room for further optimization of energy efficiency and emission indicators.

A Fault Diagnosis Method for the Roller-Marks in Offset Printing Machine Based on Texture Recognition

2012 ◽  
Vol 262 ◽  
pp. 361-366
Author(s):  
Zhuo Fei Xu ◽  
Hai Yan Zhang ◽  
Ling Hui Ren
Keyword(s):  
Fault Diagnosis ◽  
High Speed ◽  
Solution Method ◽  
Offset Printing ◽  
Texture Recognition ◽  
Defect Image ◽  
Diagnosis Method ◽  
The Difference ◽  
Detecting Method ◽  
Printing Machine

Roller-mark is a common problem in offset printing and its solution method is important for printing. A new detecting method of texture analysis was given in this paper. In this study, printing image was acquired with high-speed CCD. Compared the difference between printing image and standard image, a defective image was obtained. Then the reason of roller-marks was given by the texture recognition of defect image. Finally, experiments were taken to prove the feasibility and effectiveness of this new method for the roller-marks diagnosis in the offset printing machine.

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