scholarly journals Detection of Magnetomechanical Effect in Structural Steel Using GMR 2nd Order Gradiometer Based Sensors

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4147 ◽  
Author(s):  
Carmela Bonavolontà ◽  
Massimo Valentino ◽  
Francesco Penta ◽  
Carmine Granata ◽  
Berardo Ruggiero ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Dislocation Density ◽  
Crack Initiation ◽  
Structural Steel ◽  
Residual Magnetization ◽  
Test Material ◽  
Invasive Technique ◽  
Non Invasive ◽  
Gmr Sensors ◽  
Magnetomechanical Effect

The magneto-mechanical behaviour of structural steel specimens stressed up to the plastic deformation stage was investigated using a 2nd order gradiometer based on Giant Magneto Resistive (GMR) sensors. The correlation between the gradient of the magnetization and the dislocation density before the crack initiation inside the test material was reported. The capability of the GMR scanning sensor to detect the residual magnetization due to the tensile stress with a non-invasive technique was demonstrated.

Effect of Optimization of Shot Peening Parameters on Surface Integrity of NAK80

2010 ◽  
Vol 426-427 ◽  
pp. 537-539 ◽  
Author(s):  
Hong Miao ◽  
Dun Wen Zuo ◽  
Hong Feng Wang ◽  
X.W. Sha
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Crack Initiation ◽  
Yield Stress ◽  
Surface Integrity ◽  
Shot Peening ◽  
Experimental Result ◽  
Near Surface ◽  
Crystal Block

Shot peening is known to improve the fatigue performance of materials. The improvement in fatigue is that plastic deformation in the surface increases hardness, yield stress and microstrain of thinning Crystal block and dislocation density, and formed advantaged compress residual stress that are introduced into the near-surface of the components and which hinder crack initiation and growth. But over peening effect is produced when shot peening strengthening goes beyond a certain limit, which was adverse to improve surface quality. This paper adopted the optimization of the critical peening parameters to avoid appearing over peening effect. The experimental result showed that arc high value of optimal shot peening was 0.40mm.

Investigation of shock-wave deformation history from recovered structure

1986 ◽  
Vol 44 ◽  
pp. 434-435
Author(s):  
M.A. Mogilevsky ◽  
L.S. Bushnev
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Shock Waves ◽  
Shock Front ◽  
Single Crystals ◽  
Residual Deformation ◽  
Deformation Structure ◽  
Deformation History ◽  
Deformation Velocity

Single crystals of Al were loaded by 15 to 40 GPa shock waves at 77 K with a pulse duration of 1.0 to 0.5 μs and a residual deformation of ∼1%. The analysis of deformation structure peculiarities allows the deformation history to be re-established.After a 20 to 40 GPa loading the dislocation density in the recovered samples was about 1010 cm-2. By measuring the thickness of the 40 GPa shock front in Al, a plastic deformation velocity of 1.07 x 108 s-1 is obtained, from where the moving dislocation density at the front is 7 x 1010 cm-2. A very small part of dislocations moves during the whole time of compression, i.e. a total dislocation density at the front must be in excess of this value by one or two orders. Consequently, due to extremely high stresses, at the front there exists a very unstable structure which is rearranged later with a noticeable decrease in dislocation density.

USING DOPPLER TO ASSESS THE FETAL HEALTH FOR THE PREDICTION OF GESTATIONAL OUTCOME

2014 ◽  
pp. 9-18
Author(s):  
Thi Linh Giang Truong ◽  
Vu Quoc Huy Nguyen
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Umbilical Artery ◽  
Functional Method ◽  
Invasive Technique ◽  
Routine Practice ◽  
Fetal Health ◽  
Uterine Arteries ◽  
Non Invasive ◽  
Key Words Doppler

Background: Assessment of fetal health plays the most important role in prenatal care because of influence of the prediction of gestational outcome. One of the main aims of routine antenatal care is to identify the ‘ at risk ‘ fetus in order to apply clinical interventions which could results in reduced perinatal morbidity and mortality. Doppler ultrasound is a non invasive technique whereby the movement of blood is studied by detecting the change in frequence of reflected sound, Doppler blood flow velocity waves form of fetal side (umbilical artery, middle cerebral artery ...) and maternal side ( uterine arteries) are discussed and monograms for routine practice are presented. Recently this method is important tool for qualifying high risk pregnancies and help early forecasts the health of the babies and mothers disorder. Doppler sonography in obstetrics is a widely accepted functional method of examining the prediction of gestational outcome. Key words: Doppler, umbilical artery, middle cerebral artery, uterine arteries

scholarly journals Thermal Liquid Biopsy (TLB) Focused on Benign and Premalignant Pancreatic Cyst Diagnosis

2020 ◽  
Vol 11 (1) ◽  
pp. 25
Author(s):  
Sonia Hermoso-Durán ◽  
Guillermo García-Rayado ◽  
Laura Ceballos-Laita ◽  
Carlos Sostres ◽  
Sonia Vega ◽  
...  
Keyword(s):  
Liquid Biopsy ◽  
Pancreatic Cyst ◽  
Point Of View ◽  
Invasive Technique ◽  
Background Current ◽  
Interesting Point ◽  
Pancreatic Lesion ◽  
Non Invasive ◽  
Patient Diagnosis ◽  
New Biomarkers

Background: Current efforts in the identification of new biomarkers are directed towards an accurate differentiation between benign and premalignant cysts. Thermal Liquid Biopsy (TLB) has been previously applied to inflammatory and tumor diseases and could offer an interesting point of view in this type of pathology. Methods: In this work, twenty patients (12 males and 8 females, average ages 62) diagnosed with a pancreatic cyst benign (10) and premalignant (10) cyst lesions were recruited, and biological samples were obtained during the endoscopic ultrasonography procedure. Results: Proteomic content of cyst liquid samples was studied and several common proteins in the different groups were identified. TLB cyst liquid profiles reflected protein content. Also, TLB serum score was able to discriminate between healthy and cysts patients (71% sensitivity and 98% specificity) and between benign and premalignant cysts (75% sensitivity and 67% specificity). Conclusions: TLB analysis of plasmatic serum sample, a quick, simple and non-invasive technique that can be easily implemented, reports valuable information on the observed pancreatic lesion. These preliminary results set the basis for a larger study to refine TLB serum score and move closer to the clinical application of TLB providing useful information to the gastroenterologist during patient diagnosis.

Computation on continuous grain refinement in AA1050 aluminum during repetitive tube expansion and shrinking technique

2015 ◽  
Vol 232 (4) ◽  
pp. 307-318
Author(s):  
H Jafarzadeh ◽  
K Abrinia
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Grain Size ◽  
Finite Element ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Half Cycle ◽  
Tube Expansion ◽  
Element Method

The microstructure evolution during recently developed severe plastic deformation method named repetitive tube expansion and shrinking of commercially pure AA1050 aluminum tubes has been studied in this paper. The behavior of the material under repetitive tube expansion and shrinking including grain size and dislocation density was simulated using the finite element method. The continuous dynamic recrystallization of AA1050 during severe plastic deformation was considered as the main grain refinement mechanism in micromechanical constitutive model. Also, the flow stress of material in macroscopic scale is related to microstructure quantities. This is in contrast to the previous approaches in finite element method simulations of severe plastic deformation methods where the microstructure parameters such as grain size were not considered at all. The grain size and dislocation density data were obtained during the simulation of the first and second half-cycles of repetitive tube expansion and shrinking, and good agreement with experimental data was observed. The finite element method simulated grain refinement behavior is consistent with the experimentally obtained results, where the rapid decrease of the grain size occurred during the first half-cycle and slowed down from the second half-cycle onwards. Calculations indicated a uniform distribution of grain size and dislocation density along the tube length but a non-uniform distribution along the tube thickness. The distribution characteristics of grain size, dislocation density, hardness, and effective plastic strain were consistent with each other.

278 Assessing effects of lateral tilt on cardiac output using a Non-invasive technique

2021 ◽  
Vol 224 (2) ◽  
pp. S182-S183
Author(s):  
Zaid Diken ◽  
Antonio F. Saad ◽  
Sema Hajmurad ◽  
Rakesh Vadhera ◽  
Michelle Simon ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Invasive Technique ◽  
Lateral Tilt ◽  
Non Invasive

Simulation of Grain Growth of Materials Produced by Severe Plastic Deformation

2011 ◽  
Vol 409 ◽  
pp. 597-602
Author(s):  
Yuichi Mizuno ◽  
Kenji Okushiro ◽  
Yoshiyuki Saito
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Boundary Migration ◽  
Interface Energy ◽  
Diffusion Reaction ◽  
Field Methods

Grain boundary migration in materials under severe plastic deformation was simulated by the phase field methods. The interface energy and dislocation density on growth kinetics were simulated on systems of 2-dimensional lattice. .In inhomogeneous systems grain size distributions in simulated grain structures were binodal distributions. The classification of the solution of differential equations based on the mean-field Hillert model describing temporal evolution of the scaled grain size distribution function was in good agreement with those given by the Computer simulations. Effect of dislocation on thermodynamic stability was taken into consideration. Dislocation density distribution was calculated by a equation based on the diffusion-reaction equation.. Scaled grain size distribution was known to be affected by the dislocation.

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