Vortex Annihilation Dependence of Chirality in Asymmetric Permalloy Dots

SPIN ◽  
2019 ◽  
Vol 09 (01) ◽  
pp. 1950001
Author(s):  
Kuo-Ming Wu ◽  
Chao-Hsien Huang ◽  
Deng-Shiang Shiu ◽  
Yun Hong ◽  
Kao-Fan Lai ◽  
...  

Geometric asymmetry effect on vortex annihilation was investigated in series of submicro-scaled permalloy dots. By introducing the one-side-flat asymmetric shape into circular magnetic disks, the original degenerate signals of vortex annihilation for different chirality are separated into two different trajectories, where the asymmetry level is quantified by an excised angle. The separation of annihilation field for clockwise and counterclockwise vortex shows as a function of the excised angle. The asymmetry influence on the separation of annihilation field is discussed from the view of disk aspect ratio and flat boundary effect. Comparison of experimental results with numerical simulations is also presented.

2018 ◽  
Vol 17 (1-2) ◽  
pp. 36-51 ◽  
Author(s):  
KBMQ Zaman ◽  
JE Bridges

Flow and noise fields are explored for the concept of distributed propulsion. A model-scale experiment is performed with an 8:1 aspect ratio rectangular nozzle that is divided into six passages by five septa. The septa geometries are created by placing plastic inserts within the nozzle. It is found that the noise radiation from the septa nozzle can be significantly lower than that from the baseline rectangular nozzle. The reduction of noise is inferred to be due to the introduction of streamwise vortices produced by secondary flow within each passage. Thus, the geometry of the internal passages of the septa nozzle can have a large influence. The flow evolution is profoundly affected by slight changes in the geometry. These conclusions are reached by experimental results of the flowfield aided by brief numerical simulations.


2012 ◽  
Vol 1 (33) ◽  
pp. 47
Author(s):  
Piero Ruol ◽  
Luca Martinelli ◽  
Paolo Pezzutto

The aim of this work is to assess, by means of available experimental results and numerical simulations, the possible extension of the range of application of the formula proposed by Ruol et al. (J. Wat. Port, Coast. Ocean Eng., 1, 2013), giving wave transmission for chain-moored -type floating breakwaters. The formula is here applied out of the range used for its calibration and even to other types of FBs. The error between predicted and measured values is described and discussed with reference to the main geometrical variables. It appears that the formula performs fairly well for the box-type FB, but not in cases characterized by very different mooring stiffness compared to the one used for calibration. For instance in case of fixed or tethered FBs, the formula significantly overestimates the wave transmission.


2020 ◽  
Vol 117 (6) ◽  
pp. 615
Author(s):  
Ping Shen ◽  
Lei Zhou ◽  
Qiankun Yang ◽  
Zhiqi Zeng ◽  
Kenan Ai ◽  
...  

In 38MnVS6 steel, the morphology of sulfide inclusion has a strong influence on the fatigue life and machinability of the steel. In most cases, the MnS inclusions show strip morphology after rolling, which significantly affects the steel quality. Usually, the MnS inclusion with a spherical morphology is the best morphology for the steel quality. In the present work, tellurium was applied to 38MnVS6 micro-alloyed steel to control the MnS inclusion. Trace tellurium was added into 38MnVS6 steel and the effect of Te on the morphology, composition, size and distribution of MnS inclusions were investigated. Experimental results show that with the increase of Te content, the equivalent diameter and the aspect ratio of inclusion decrease strikingly, and the number of inclusions with small aspect ratio increases. The inclusions are dissociated and spherized. The SEM-EDS analysis indicates that the trace Te mainly dissolves in MnS inclusion. Once the MnS is saturated with Te, MnTe starts to generate and wraps MnS. The critical Te/S value for the formation of MnTe in the 38MnV6 steel is determined to be approximately 0.075. With the increase of Te/S ratio, the aspect ratio of MnS inclusion decreases and gradually reaches a constant level. The Te/S value in the 38MnVS6 steel corresponding to the change of aspect ratio from decreasing to constant ranges from 0.096 to 0.255. This is most likely to be caused by the saturation of Te in the MnS inclusion. After adding Te in the steel, rod-like MnS inclusion is modified to small inclusion and the smaller the MnS inclusion, the lower the aspect ratio.


1987 ◽  
Vol 19 (12) ◽  
pp. 79-83
Author(s):  
K. Bartoszewski ◽  
A. Bilyk

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.


1996 ◽  
Vol 324 ◽  
pp. 163-179 ◽  
Author(s):  
A. Levy ◽  
G. Ben-Dor ◽  
S. Sorek

The governing equations of the flow field which is obtained when a thermoelastic rigid porous medium is struck head-one by a shock wave are developed using the multiphase approach. The one-dimensional version of these equations is solved numerically using a TVD-based numerical code. The numerical predictions are compared to experimental results and good to excellent agreements are obtained for different porous materials and a wide range of initial conditions.


2013 ◽  
Vol 732-733 ◽  
pp. 809-812 ◽  
Author(s):  
Hong Rui Liu ◽  
Chao Ying Xia

This paper proposes an equalizer for serially connected Lithium-ion battery cells. The battery cell with the lowest state of charge (SOC) is charged by the equalizer during the process of charging and discharging, and the balancing current is constant and controllable. Three unbalanced lithium-ion battery cells in series are selected as the experimental object by this paper. The discharging current under a certain UDDS and 20A charging current are used to complete respectively one time balancing experiment of discharging and charging to the three lithium-ion battery cells. The validity of the balancing strategy is confirmed in this paper according to the experimental results.


1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.


Author(s):  
Hagen Kohl ◽  
Lisa Schade ◽  
Gabor Matthäus ◽  
Tobias Ullsperger ◽  
Burak Yürekli ◽  
...  

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