high gradient
Recently Published Documents


TOTAL DOCUMENTS

1371
(FIVE YEARS 178)

H-INDEX

47
(FIVE YEARS 7)

2022 ◽  
Vol 175 ◽  
pp. 107290
Author(s):  
Zixing Xue ◽  
Yuhua Wang ◽  
Xiayu Zheng ◽  
Dongfang Lu ◽  
Zixi Sun ◽  
...  

2022 ◽  
Author(s):  
Stuart John Frederick Forde Ramage ◽  
Eulyn Pagaling ◽  
Reza K. Haghi ◽  
Lorna A. Dawson ◽  
Kyari Yates ◽  
...  

2022 ◽  
Vol 2160 (1) ◽  
pp. 012057
Author(s):  
Purong Wang ◽  
Guoyin Xu

Abstract As one of the most effective techniques for fine particle processing, high gradient magnetic separation is mainly used in the separation and enrichment of fine and weak magnetic particles and other important industrial fields. High gradient magnetic separator is a new type of high intensity magnetic separator, which has strong ability to capture fine and weak magnetic particles, developed on the basis of ordinary high intensity magnetic separator. Based on the early periodic- high -gradient magnetic separators, the optimization development direction of high gradient magnetic separators and their application characteristics of various high gradient magnetic separators in these decades were summarized, and the future development directions of high gradient magnetic separator were presented.


Author(s):  
Ronald Agustsson ◽  
Paul Carriere ◽  
Osvaldo Chimalpopoca ◽  
Valery A. Dolgashev ◽  
Maria A Gusarova ◽  
...  

Abstract Recent research on high-gradient radio frequency (RF) accelerating structures indicates that the use of hard copper alloys provides improvement in high gradient performance over annealed copper. Such structures are made by bonding individually manufactured parts. However, there are no well-established bonding techniques that preserve the hardness, surface finish and cleanliness required for high gradient operation. To preserve the copper hardness, RadiaBeam has developed a joining technique based on electron beam welding. This technique provides efficient bonding with strong, clean welds and minimal thermal loading, while maintaining a clean inner RF environment. Our RF design and fabrication methodology limits the small heat affected zone to the outer cavity envelop, with virtually no distortions or thermal loading of critical RF surfaces. It also incorporates provisions to precisely control the gap despite conventional issues with weld joint shrinkage. To date we have manufactured and validated an RF accelerating structure joined by electron-beam welding that incorporates a novel open split design to significantly reduce the assembly complexity and cost. In this paper, we will present the electromagnetic design of this structure, discuss bonding, and present the results of high-power tests, where the accelerating gradients of 140 MV/m with surface peak fields of 400 MV/m were achieved for flat-top pulse length of 600 ns with an RF breakdown rate of 10-4 1/(pulse∙m).


2021 ◽  
Vol 8 (6) ◽  
pp. 967-973
Author(s):  
Collins Olusola Akeremale ◽  
Oluwasegun Adeyemi Olaiju ◽  
Su Hoe Yeak

This article considered the traditional finite element method (FEM) and adaptive finite element method (FEM) for the numerical solution of the one-dimensional boundary value problems. We established the preference or the superiority of the h-adaptive FEM to traditional FEM in high gradient problems in terms of accuracy and cost of computation. Numerical examples which confirm the performance and adaptability of the h-adaptive method over the traditional finite element method and the high accuracy of the numerical solution are presented. Detailed error analysis of linear elements was also discussed. In conclusion, h-adaptive FEM is recommended for complex systems with high gradient problems.


Author(s):  
Parveen Sihag ◽  
Balraj Singh ◽  
Md. Azlin Bin Md. Said ◽  
H. Md. Azamathulla

Abstract The coefficient of Manning's roughness (n) has been generally implemented in the determination of depth and discharge in open channels and canals. This study unravels the novel idea and potential of Random Forest (RF), M5P, and Random Tree (RT) approaches to evaluate and predict the coefficient of Manning's roughness for hydraulic designing. To achieve this purpose, 42 observations are collected for high-gradient streams in Colorado, USA. All the observations are from boulder-bed, cobble and high gradient (S > 0.002 m/m) streams for within bank flows. In order to ascertain the best model, the above-mentioned approaches are evaluated and compared using performance evaluation indices such as mean absolute error (MAE), coefficient of correlation (CC), and root mean square error (RMSE). Outcomes of performance evaluation indices revealed that the proposed pruned M5P approach outperformed other applied models for predicting the coefficient of Manning's roughness for hydraulic designing with CC = 0.7858, 0.7910, RMSE = 0.0195, 0.0195, and MAE = 0.0157, 0.0165 for model development and validation period, correspondingly. Furthermore, Taylor diagram and Box plot also suggest that M5P based approach works better than RF and RT based approaches for predicting the coefficient of Manning's roughness for high-gradient streams using the given data set.


2021 ◽  
Author(s):  
Se Jin Choi ◽  
Yura Ahn ◽  
Hyun Jung Koo ◽  
Dae-Hee Kim ◽  
Soyeon Lim ◽  
...  

Abstract Aortic valve calcium scoring by cardiac computed tomographic (CT) has been recommended as an alternative to classify the AS severity, but it is unclear that whether CT findings can predict and have prognostic implication in low-flow, low-gradient aortic stenosis (LF-LG AS), which has fewer benefit from surgery among the AS subtypes. In this study, we examined the clinical and cardiac CT findings of LF-LG AS patients and evaluated factors affecting outcomes after surgical aortic valve replacement (AVR). This study included 511 (66.9±8.8 years, 55% men) consecutive patients with severe AS who underwent surgical AVR. Aortic valve area (AVA) was obtained by echocardiography (AVAecho) and by CT (AVACT) using each modalities measurement of the left ventricular outflow tract. Patients with AS were classified as 1) high-gradient severe (n=438), 2) classic LF-LG (n=18), and 3) paradoxical LF-LG (n=55) based on echocardiography. Classic LF-LG AS patients had higher end-systolic and end-diastolic volume indices, lower left ventricular ejection fraction, larger AVAecho and AVACT, and larger aortic annulus compared to high-gradient severe AS (P<0.05, for all). In classic LF-LG AS group, 27.8% of patients presented AVACT≥1.2 cm2. After multivariable adjustment, old age (hazard ratio [HR], 1.04, P=0.049), high B-type natriuretic peptide (BNP) (HR, 1.005; P<0.001), preoperative atrial fibrillation (HR, 2.75; P=0.003), classic LF-LG AS (HR, 5.53, P=0.004), and small aortic annulus (HR, 0.57; P=0.002) were independently associated with major adverse cardiac and cerebrovascular events (MACCE). The classic LF-LG AS group presented larger AVACT and aortic annulus than those in high-gradient severe AS group and one third of them had AVACT ≥1.2 cm2. Old age, high BNP, atrial fibrillation, classic LF-LG AS, and small aortic annulus were associated with MACCE in severe AS patients after surgical AVR.


Sign in / Sign up

Export Citation Format

Share Document