scholarly journals Improved PRF‐based MR thermometry using k‐space energy spectrum analysis

2020 ◽  
Vol 84 (6) ◽  
pp. 3325-3332
Author(s):  
Shenyan Zong ◽  
Guofeng Shen ◽  
Chang‐Sheng Mei ◽  
Bruno Madore
Keyword(s):  
Energy Spectrum ◽  
Spectrum Analysis ◽  
Mr Thermometry ◽  
Energy Spectrum Analysis

Fracture Failure Research on Feculence Discharge Pipe of LPG Spherical Tanks

2014 ◽  
Author(s):  
Wang Chen ◽  
Chen Jin ◽  
Cai XiaoHui ◽  
Wang YinPei
Keyword(s):  
Energy Spectrum ◽  
Spectrum Analysis ◽  
Sem Analysis ◽  
Corrosion Products ◽  
Welding Residual Stress ◽  
Liquefied Petroleum Gas ◽  
Metallographic Examination ◽  
Fracture Failure ◽  
Energy Spectrum Analysis ◽  
Discharge Pipe

The rupturing of feculence discharge pipe happened during the gas-tightness test of LPG (Liquefied petroleum gas) spherical tanks. In order to find out the reasons of fracture failure of feculence discharge pipe, the Scanning electron microscopy (SEM) analysis, mechanical property testing, metallographic examination and energy spectrum analysis of corrosion products were used. The examination results show that both chemical composition and metallographic structure are normal, and the cracking is the brittle cleavage fracture. The energy spectrum analysis of corrosion products reveals that there are many sulfides in the corrosion products. Based on the loading conditions of spherical tanks, crack morphology and corrosion products, the primary reason of pipe cracking is stress corrosion cracking induced by H2S existed in liquefied petroleum gas. So it is suggested that the examination should be fulfilled for the feculence discharge pipe of such spherical tanks, the cracked pipes should be replaced, and the welding residual stress in the pipes should be relieved before replacing operation.

Experimental Research on Energy Spectrum Analysis on Chips from Aeroengine Oil System

2014 ◽  
Vol 635-637 ◽  
pp. 957-961
Author(s):  
Chun Guang Li ◽  
Xiao Ming Ma ◽  
Hai Jun Tang
Keyword(s):  
Energy Spectrum ◽  
Spectrum Analysis ◽  
Energy Dispersive Spectrometer ◽  
Engineering Practice ◽  
Energy Spectrum Analysis ◽  
Analysis Technique ◽  
Metal Chips ◽  
Spectrum Curve ◽  
Appearance Feature ◽  
Electronic Microscope

Inspection on chips from oil system is an important method for modern aeroengine condition monitoring. Energy spectrum analysis technique is the most widely used and effective method in inspection on metal chips. In this method, size and quantity of chips are observed by scanning electronic microscope and qualitative and quantitative analysis of element contents are finished by energy dispersive spectrometer. Through above experiments, material type of metal chips can be analyzed and material mark can be determined by comparison with the materials list used in the aeroengine. In this article, characteristics and advantages of energy spectrum analysis technology are systematically introduced and typical appearance feature and energy spectrum curve of common l chips are summarized in engineering practice. In addition, problems and prospects of energy spectrum analysis technique are proposed.

scholarly journals Energy Spectrum Study and Optimal Design of an Inerter-Based Structure Considering the Underlying Soil

2020 ◽  
Vol 10 (9) ◽  
pp. 2999
Author(s):  
Qingjun Chen ◽  
Yanchao Wang ◽  
Zhipeng Zhao
Keyword(s):  
Energy Spectrum ◽  
Energy Dissipation ◽  
Spectrum Analysis ◽  
Energy Characteristics ◽  
Energy Spectrum Analysis ◽  
Mass Damper ◽  
Balance Analysis ◽  
Viscous Mass ◽  
Energy Balance Analysis ◽  
Underlying Soil

As a classic inerter system, the tuned viscous mass damper (TVMD) has been proven to be efficient for vibration control. It is characterized by an amplification effect, where the deformation of the dashpot in the TVMD can be larger than that of a single dashpot, providing enhanced energy dissipation. However, the contribution of this system to the enhancement of the energy dissipation quantity and vibration control remains unclear. To deal with this, and considering the underlying soil, this study proposes a systematic energy spectrum analysis framework for the single-degree-of-freedom (SDOF) element controlled by a tuned viscous mass damper (TVMD) in order to reveal the energy characteristics of the TVMD and develop an optimal energy dissipation enhancement-based design. The proposed energy spectrum analysis includes ground motion propagation and energy balance analysis. Considering the underlying soil, energy balance analysis is performed for a series of SDOF elements connected to the TVMD, which yields a fitted input energy spectrum for optimal design of the TVMD. Extensive parametric analysis reveals energy characteristics of the TVMD compared with a single dashpot, yielding an optimal energy dissipation enhancement-based design. The findings of this study show that by considering the soil underneath the inerter-based structure, the developed energy spectrum analysis quantifies the degree of energy dissipation enhancement effect of the TVMD. The proposed design is effective in guaranteeing the target of displacement control, which optimizes the efficiency and quantity of the TVMD for energy dissipation, relieving the energy-dissipation burden on the primary element.

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