scholarly journals Analysis of Electromagnetic Force And Formability of Tube Electromagnetic Bulging Based On Convex Magnetic Field Shaper

2021 ◽  
Author(s):  
Weiye Wu ◽  
Li Qiu ◽  
A. Abu-Siada ◽  
Chenglin Wang ◽  
Jinbo Jiang
Keyword(s):  
Magnetic Field ◽  
Wall Thickness ◽  
Electromagnetic Force ◽  
Coupling Model ◽  
Relative Wall Thickness ◽  
Thickness Reduction ◽  
Axial Deformation ◽  
Electromagnetic Structure ◽  
Forming Technology ◽  
Tube Bulging

Abstract In order to solve the problems of non-uniform axial deformation and thinning of wall thickness in traditional tube electromagnetic bulging, a method of tube electromagnetic bulging based on convex magnetic field shaper is proposed in this paper. The electromagnetic-structure coupling model is constructed by using COMSOL software, and the influence of convex magnetic field shaper structure on radial and axial electromagnetic force, axial deformation uniformity and wall thickness reduction is analyzed, and compared with traditional tube electromagnetic bulging. The results show that by using this method, the axial deformation uniformity is increased by 4.2 times, and the relative wall thickness is reduced by 33%. Obviously, this method of tube bulging can effectively overcome the problems existing in traditional tube electromagnetic bulging and promote the wide application of electromagnetic forming technology.

scholarly journals Electromagnetic Force Distribution and Wall Thickness Reduction of Three-Coil Electromagnetic Tube Bulging With Axial Compression

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 21665-21675 ◽  
Author(s):  
Li Qiu ◽  
Wang Zhang ◽  
A. Abu-Siada ◽  
Qi Xiong ◽  
Chenglin Wang ◽  
...  
Keyword(s):  
Axial Compression ◽  
Wall Thickness ◽  
Electromagnetic Force ◽  
Thickness Reduction ◽  
Force Distribution ◽  
Tube Bulging

Abstract 16018: Impaired Intrinsic Myocardial Shortening in Both Two Directions and Compensatory Mechanism to Maintain Left Ventricular Ejection Fraction in Patients With Hypertensive Heart Disease

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Satoshi Yamada ◽  
Kazunori Okada ◽  
Hisao Nishino ◽  
Hiroyuki Iwano ◽  
Daisuke Murai ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ejection Fraction ◽  
Wall Thickness ◽  
Circumferential Strain ◽  
Hypertensive Heart Disease ◽  
Wall Stress ◽  
Left Ventricular ◽  
Relative Wall Thickness ◽  
Left Ventricular Ejection ◽  
Compensatory Mechanism

Background: Longitudinal myocardial shortening is known to be reduced even if left ventricular (LV) ejection fraction (EF) is preserved in patients with hypertensive heart disease (HHD). However, the compensatory mechanism remains to be elucidated. Thus layer-specific longitudinal and circumferential strain as well as stress-strain relationship was observed in HHD patients. Methods: In 46 HHD patients with preserved EF (>50%) and 29 age-matched control subjects, global longitudinal strain (LS) and layer-specific circumferential strain (CS) were measured from the apical 4-chamber view and mid-ventricular short-axis view, respectively, by using speckle tracking echocardiography. LS was measured at innermost LV wall layer, and CS at innermost, midwall, and outermost layers. Layer-specific end-systolic circumferential wall stress (CWS) according to Mirsky’s formula and endocardial meridional wall stress (MWS) were calculated. Results: Systolic blood pressure (147±20 mm Hg), interventricular septal thickness (13±2 mm), and LV dimension (48±4 mm) were greater in HHD than controls, whereas EF was comparable (66±8 vs 66±5%). LS was smaller in HHD than controls (-13±3 vs -17±3%, p<0.001) in spite of reduced MWS (520±141 vs 637±164 dyn·mm -2 , p<0.01), suggesting impaired longitudinal myocardial function in HHD. Similarly, CS was smaller in HHD than controls at outer layer (-6.8±2.2 vs -8.8±2.2%, p<0.01) and at midwall (-11.3±3.4 vs -13.9±3.2%, p<0.01) in spite of reduced CWS (outer: 238±82 vs 336±110 dyn·mm -2 , p<0.001; mid: 360±107 vs 473±131 dyn·mm -2 , p<0.001). In contrast, at the innermost layer, both CS (-26±5 vs -25±5%, p=0.41) and CWS (979±153 vs 992±139 dyn·mm -2 , p=0.72) were comparable between groups. Furthermore, the difference of CS between inner and outer layers significantly correlated with relative wall thickness (r=-0.33, p<0.01). Finally, CS at inner layer significantly correlated with EF (r=-0.43, p<0.001), whereas LS did not. Conclusions: In patients with HHD, intrinsic myocardial shortening was impaired both longitudinally and circumferentially. Some compensatory mechanism associated with increased relative wall thickness might work to maintain subendocardial CS, resulting in preserved EF.

Abstract 4197: Does Relative Wall Thickness or Left Ventricular Mass Index Best Predict Mortality Risk in Patients With Preserved Systolic Function?

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Dharmendrakumar A Patel ◽  
Carl J Lavie ◽  
Sangeeta Shah ◽  
Yvonne Gilliland ◽  
Richard V Milani
Keyword(s):  
Wall Thickness ◽  
Systolic Function ◽  
Age Groups ◽  
Left Ventricular ◽  
Relative Wall Thickness ◽  
Prognostic Impact ◽  
Geometric Patterns ◽  
Lv Mass ◽  
Mortality Table ◽  
The Impact

Background: Several studies have indicated that left ventricular (LV) geometric patterns predict cardiovascular events. However, little data is available that compares the relative prognostic impact of LV mass index (LVMI) and relative wall thickness (RWT) on mortality in a large cohort of patients with preserved systolic function. Methods: The impact of LVMI and RWT on mortality during an average follow-up of 1.7±1.0 years was examined in a sample of 47,701 patients (mean age: 61.6 ± 15.4; females=54.6 %) with preserved ejection fraction(EF), as well as in age groups of <50 yrs(n=10,864; mean age=39.9 ± 8.1; females=58.4 %), 50 –70 yrs (n=20,181; mean age=59.9 ± 5.7; females=52.2 %) and >= 70 yrs (n=16,836; mean age=77.7 ± 5.5; females=55.1 %). Results: With increasing age (<50, 50 –70, >=70 yrs), both LVMI (78.5 ± 23.4, 84.3 ± 25.4, 90.3 ± 27.6; p<0.0001) and RWT (0.37 ± 0.08, 0.41 ± 0.08, 0.43 ± 0.09; p<0.0001) as well as mortality (2.2%, 5.0%, 14.2%; p<0.0001) showed significant linear trends and were independent predictors of mortality (Table , Figure ). Conclusion: Although, both LVMI and RWT were independently associated with increased mortality in all groups, RWT was by far the strongest independent predictor of all-cause mortality, especially in younger patients.

Abstract 11093: Layer-specific Quantification of Myocardial Deformation by Strain Echocardiography May Reveal the Mechanism of Preserved Left Ventricular Ejection Fraction in Patients With Hypertrophic Cardiomyopathy

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jing Ping Sun ◽  
Xianda Ni ◽  
Tingyan Xu ◽  
Min Xu ◽  
Xing Sheng Yang ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Ejection Fraction ◽  
Wall Thickness ◽  
Radial Strain ◽  
Left Ventricular ◽  
Relative Wall Thickness ◽  
Left Ventricular Ejection ◽  
Compensatory Mechanisms ◽  
Ventricular Ejection Fraction ◽  
Bull's Eye

Purpose: We aimed to evaluate compensatory mechanisms in hypertrophic cardiomyopathy (HCM) patients (pts) with preserved left-ventricular (LV) ejection fraction (EF). Methods: Speckle-tracking echocardiography (Vivid E9, GE) was performed in 50 HCM with preserved LV EF (38 m; 49± 14 y, all LV EF > 55%) and 50 age, gender matched controls (38 m; 49±12 y). The global and segmental longitudinal (LS), circumferential (CS) and radial strain (RS) strains of endocardia (End), mid-wall and epicardia layers were analyzed using a novel layer-specific TTE. The ratio of End to epicardia strain (End/Epi) was calculated. Results: The LV EF were similar in pts and controls (64±8 vs 64±7 %, p=0.95). The diastolic function was significantly impaired in HCM pts compared with controls (E/E’:18.4±8.4 vs 8.6 ±2.4, p<0.0001). The absolute value of LS and CS was reserved at apical End layers (-34±7 vs -35±6, p=0.44); the remaining segments and LV global LS and CS of three layers were significantly smaller (LS,-16±5 vs -22±3; CS -24±8 vs -33±7; p<0.0001), and LS and CS End/Epi (1.7±0.3 vs 1.3±0.1, 3.4±1.1 vs 1.7±0.2 respectively, P <0.0001) was significantly higher in HCM pts than in controls. The RS and LV twist were preserved in all LV segments (27±10 vs 24±12, p=0.19; 20±8 vs 18±5, p=0.33; respectively). In HCM pts, the LV LS value at basal and middle levels revealed significant negative correlations with LV relative wall thickness (r=–0.65, –0.59 and –0.60, –0.54, respectively , p< 0.0001); and mild negative correlations (r=-0.33,-0.29, p<0.0001). The LV CS value at all levels revealed mild correlations with relative wall thickness (r=-0.22, p<0.05) . The LS were significantly reduced at the hypertrophic segments (Figure). Conclusions: In HCM patients with preserved LVEF, LV GLS was impaired, but apical End LS and basal End CS, LV RS as well as LV twist were maintained as the compensation for reduction LV LS and CS. The Bull’s eye of LS may help us to localize the lesion segments and define the type of HCM.

scholarly journals P955 left ventricle cardiac remodeling among lithuanian football versus basketball players

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
A Aldujeli ◽  
J Laukaitiene ◽  
R Unikas
Keyword(s):  
Left Ventricle ◽  
Wall Thickness ◽  
Cardiac Remodeling ◽  
Interventricular Septum ◽  
Posterior Wall ◽  
Left Ventricular ◽  
Relative Wall Thickness ◽  
Football Players ◽  
Basketball Players ◽  
Lv Mass

Abstract Background Regular physical exercise causes a continuous gradual increase of the cardiac left ventricular (LV) mass known as physiological adaptive hypertrophy. The extent of LV remodeling depends on the type, amount, and intensity of the exercise. Purpose The aim of this study was to compare structural changes of the heart among Lithuanian football, basketball players and unathletic controls. Methods A total of 50 Lithuanian males aged between 20-29 years volunteered to participate in the study. Football players (n = 15) playing for local II league football clubs,and Basketball players (n = 15) playing for local minor league basketball teams. All athletes had been regularly engaged in their sport for at least three years. Inactive healthy volunteers (n = 20) of similar age served as controls. Routine transthoracic echocardiographic examinations to measure end-diastolic LV dimensions were performed by cardiology fellow under the supervision of a fully licensed cardiologist. Statistical analyses were performed using the SPSS 20.0 software. The value of p &lt; 0,05 was considered as statistically significant. Results No structural or functional pathologies were evident during the echocardiographic examination in any of the subjects. Absolute interventricular septum (IVS) thickness and LV posterior wall thickness, but not LV diameter, were higher in athletes than in inactive controls (P &lt; 0,001). Indexed LV diameter was higher in football players as compared with non-athlete controls and basketball players (P &lt; 0,05). Left ventricular mass of all athletes were higher as compared with controls (p &lt; 0.001). Relative wall thickness was not increased in football players but was higher in basketball players as compared with controls (p &lt; 0.05). Conclusion Cardiac remodeling in Lithuanian football players resulted in left ventricle eccentric hypertrophy due to the LV dilation, increased LV mass and relatively normal relative wall thickness. However in Lithuanian basketball players we noticed an increase in both relative wall thickness and LV mass resulting in LV concentric hypertrophy. Echocardiographic characteristics Groups n End-diastolic LV diameter(mm) End-diastolic Interventricular septum (mm) End-diastolic LV posterior wall LV mass Football Players 15 56.9 10.8 10.8 242 Basketball players 15 53.6 11.5 11.3 254 Inactive individuals 20 53.2 9.1 9.5 182 P value 0.01 &lt;0.001 &lt;0.001 &lt;0.01 Abstract P955 Figure.

scholarly journals The Simulation and Optimization of an Electromagnetic Field in a Vertical Continuous Casting Mold for a Large Bloom

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 516
Author(s):  
Lianwang Zhang ◽  
Changjun Xu ◽  
Jiazheng Zhang ◽  
Tao Wang ◽  
Jing Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Continuous Casting ◽  
Electromagnetic Force ◽  
Three Dimensional ◽  
Electromagnetic Stirring ◽  
Current Intensity ◽  
Continuous Casting Mold ◽  
Current Frequency ◽  
Simulation And Optimization ◽  
Electromagnetic Model

The electromagnetic model of a large-bloom continuous casting was established to simulate the magnetic field. The model 3600 digital, high-precision, three-dimensional Gaussian meter was used to measure the internal magnetic field of mold electromagnetic stirring (M-EMS). The distribution of simulated magnetic field was basically consistent with that of the measured magnetic field; the accuracy of electromagnetic stirring model was verified. With the increase of current frequency, the electromagnetic force first increases and then decreases; when the current frequency is 9 Hz, the electromagnetic force reaches its maximum value. A bipolar electromagnetic stirring model is proposed; the influence of current intensity and distance were investigated. With the increase of current intensity of lower mold electromagnetic stirring (M-EMSB), the internal magnetic intensity of upper mold electromagnetic stirring (M-EMSA) gradually increases, and the middle region is gradually filled by magnetic field. With the increase of the distance, the range of the low-intensity magnetic field expands. When the current intensity of the M-EMSB is 320 A, and the distance is 400 mm, an 8 mT uniform magnetic field in the range of 1.2 m is formed. Compared with the traditional continuous casting electromagnetic agitator, the center equiaxial crystal of bipolar electromagnetic agitator increases from 30.3% to 49.5%.

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