scholarly journals Modelling and simulations for signal loss evaluation during sampling phase for thermoluminescence authenticity tests

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 150
Author(s):  
Anna Maria Gueli ◽  
Martina Pace ◽  
Stefania Pasquale ◽  
Giuseppe Politi ◽  
Giuseppe Stella ◽  
...  
Keyword(s):  
Mechanical Model ◽  
Signal Intensity ◽  
Glow Curve ◽  
Maximum Temperature ◽  
Optimal Parameters ◽  
Signal Loss ◽  
Intensity Loss ◽  
Authenticity Test ◽  
Test Result ◽  
Local Temperature Increase

<p class="Abstract"><span lang="EN-GB">In authenticity tests using the thermoluminescence (TL) method, the sampling phase is fundamental to collecting an appropriate amount of powder for analysis. The powder is usually obtained by drilling in hidden and pertinently selected areas of an artefact. During the drilling, a local temperature increase can occur, and, because thermoluminescence emission is dependent on the heating rate, the authenticity test result could be invalidated due to underestimation of the signal intensity. In this work, the percentage of signal intensity loss is investigated through the combination of a dynamic electro-mechanical model and a typical TL glow curve simulation. After first modelling the drilling procedure to estimate the maximum temperature reached, the optimal parameters that should be used during the sampling phase are checked by simulations together with an evaluation of the correlated signal losses.</span></p>

scholarly journals Liver Steatosis: Investigation of Opposed-Phase T1-weighted Liver MR Signal Intensity Loss and Visceral Fat Measurement as Biomarkers

Radiology ◽  
2008 ◽  
Vol 249 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Manisha Bahl ◽  
Aliya Qayyum ◽  
Antonio C. Westphalen ◽  
Susan M. Noworolski ◽  
Philip W. Chu ◽  
...  
Keyword(s):  
Visceral Fat ◽  
Signal Intensity ◽  
Liver Steatosis ◽  
Intensity Loss

Case 1.7

2014 ◽  
pp. 13-14
Author(s):  
Christine U. Lee ◽  
James F. Glockner
Keyword(s):  
Signal Intensity ◽  
High Signal Intensity ◽  
High Signal ◽  
Signal Loss ◽  
Quadrant Pain ◽  
Hepatic Lobe ◽  
P 75 ◽  
The Right ◽  
Dual Echo ◽  
Delayed Phase

75-year-old man with right upper quadrant pain Axial fat-suppressed dual echo FSE T2-weighted images (Figure 1.7.1) reveal a lobulated mass in the right hepatic lobe with diffuse high signal intensity. Note that on the dual echo images, there is little signal loss between the first (TE, 80 ms) and second (TE, 160 ms) echoes. Axial arterial, portal venous, equilibrium, and 5-minute delayed phase postgadolinium 3D SPGR images (...

scholarly journals Integrated slice-specific dynamic shimming for whole-body diffusion-weighted MR imaging at 1.5 T

2020 ◽  
Author(s):  
Sarah McElroy ◽  
Jessica M. Winfield ◽  
Olwen Westerland ◽  
Geoff Charles-Edwards ◽  
Joanna Bell ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Image Quality ◽  
Signal Intensity ◽  
Distortion Correction ◽  
Whole Body ◽  
Signal Loss ◽  
Diffusion Weighted ◽  
Average Signal Intensity ◽  
3D Volume ◽  
Induced Signal

Abstract Objective To compare integrated slice-specific dynamic shim (iShim) with distortion correction post-processing to conventional 3D volume shim for the reduction of artefacts and signal loss in 1.5 T whole-body diffusion-weighted imaging (WB-DWI). Methods Ten volunteers underwent WB-DWI using conventional 3D volume shim and iShim. Forty-eight consecutive patients underwent WB-DWI with either volume shim (n = 24) or iShim (n = 24) only. For all subjects, displacement of the spinal cord at imaging station interfaces was measured on composed b = 900 s/mm2 images. The signal intensity ratios, computed as the average signal intensity in a region of high susceptibility gradient (sternum) divided by the average signal intensity in a region of low susceptibility gradient (vertebral body), were compared in volunteers. For patients, image quality was graded from 1 to 5 (1 = Poor, 5 = Excellent). Signal intensity discontinuity scores were recorded from 1 to 4 (1 = 2 + steps, 4 = 0 steps). A p value of < 0.05 was considered significant. Results Spinal cord displacement artefacts were lower with iShim (p < 0.05) at the thoracic junction in volunteers and at the cervical and thoracic junctions in patients (p < 0.05). The sternum/vertebra signal intensity ratio in healthy volunteers was higher with iShim compared with the volume shim sequence (p < 0.05). There were no significant differences between the volume shim and iShim patient groups in terms of image quality and signal intensity discontinuity scores. Conclusion iShim reduced the degree of spinal cord displacement artefact between imaging stations and susceptibility-gradient-induced signal loss.

scholarly journals Signal intensity loss of the intervertebral discs in the cervical spine of young patients on fluid sensitive sequences

2015 ◽  
Vol 45 (3) ◽  
pp. 375-381 ◽  
Author(s):  
F. de Bruin ◽  
S. ter Horst ◽  
R. van den Berg ◽  
M. de Hooge ◽  
F. van Gaalen ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Signal Intensity ◽  
Young Patients ◽  
Intervertebral Discs ◽  
Intensity Loss

HEATING RATE EFFECTS ON THERMOLUMINESCENCE OF BaSO4:Eu+PTFE PREPARED AT ININ-MEXICO

2010 ◽  
Vol 24 (08) ◽  
pp. 717-726 ◽  
Author(s):  
P. R. GONZALEZ ◽  
C. FURETTA ◽  
E. CRUZ-ZARAGOZA ◽  
J. AZORÍN
Keyword(s):  
Heating Rate ◽  
Sequential Quadratic Programming ◽  
Glow Curve ◽  
Frequency Factor ◽  
Glow Peak ◽  
Maximum Temperature ◽  
Kinetics Parameters ◽  
Rate Effects ◽  
Higher Temperature ◽  
Reading System

In this work, we show the influence of heating rate (H.R.) on the thermoluminescence (TL) signal of BaSO 4 activated by Eu ions. The maximum temperature, the TL integral, the activation energy, the frequency factor and full width at half maximum of the TL glow-peak as a function of the H.R. were studied. The TL reading system used was a Harshaw TL reader model 4000, with constant H.R. in the range from 2 to 12 K/s. The irradiation dose was 0.1 Gy from 60 Co in all cases. The kinetic parameters and their dependence on the H.R. were evaluated using the sequential quadratic programming glow curve deconvolution (SQPGCD). The experimental results showed that as the H.R. increases, the IM shifts to higher temperature; similar behavior of the kinetics parameters were obtained.

Tensile Test of the Fireproof Lining of Tunnel

2011 ◽  
Vol 255-260 ◽  
pp. 170-173 ◽  
Author(s):  
Rong Yao ◽  
Dong Ling Peng ◽  
Hong Yuan Huang
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Tensile Test ◽  
Strength Loss ◽  
Maximum Temperature ◽  
Textile Fiber ◽  
Resistance Furnace ◽  
Orthogonal Method ◽  
Custom Made ◽  
Test Result

The tensile fireproof lining of tunnel test has been done in orthogonal method with a custom-made fast fluctuation thermostat type resistance furnace which the maximum temperature may arrive 1200 °C , the heater was put for heating by choosing the RABT curve, the test result was analyzed, the ratio of tensile strength loss is changed with the meter of the polypropylene textile fiber, the silica flour and the carbon fiber, there is a optimality proportion when the ratio of tensile strength loss is low.

In-Phase Signal Intensity Loss in Solid Renal Masses on Dual-Echo Gradient-Echo MRI: Association With Malignancy and Pathologic Classification

2014 ◽  
Vol 203 (4) ◽  
pp. W421-W428 ◽  
Author(s):  
David D. Childs ◽  
M. Jennings Clingan ◽  
Ronald J. Zagoria ◽  
Joseph Sirintrapun ◽  
Kaan Tangtiang ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Gradient Echo ◽  
Renal Masses ◽  
Pathologic Classification ◽  
Phase Signal ◽  
Dual Echo ◽  
Intensity Loss

Origin of a Signal Intensity Loss Artifact in Fat-Saturation MR Imaging

Radiology ◽  
2000 ◽  
Vol 217 (3) ◽  
pp. 911-915 ◽  
Author(s):  
Leon Axel ◽  
Louis Kolman ◽  
Riad Charafeddine ◽  
Scott N. Hwang ◽  
Alan H. Stolpen
Keyword(s):  
Mr Imaging ◽  
Signal Intensity ◽  
Fat Saturation ◽  
Intensity Loss

Case 6.3

2014 ◽  
pp. 287-288
Author(s):  
Christine U. Lee ◽  
James F. Glockner
Keyword(s):  
Adrenal Gland ◽  
Signal Intensity ◽  
Adrenal Mass ◽  
Chest Ct ◽  
Adrenal Lesion ◽  
Signal Loss ◽  
Chest Discomfort

52-year-old woman with chest discomfort; chest CT showed an indeterminate adrenal lesion A well-circumscribed left adrenal mass shows signal intensity similar to that of the normal adrenal gland on coronal SSFSE (Figure 6.3.1) and axial fat-suppressed FSE T2-weighted (Figure 6.3.2) images. Notice the extensive signal loss within the lesion between IP (...

Case 5.17

2014 ◽  
pp. 274-275
Author(s):  
Christine U. Lee ◽  
James F. Glockner
Keyword(s):  
Hepatitis C ◽  
Signal Intensity ◽  
Cirrhotic Liver ◽  
Signal Loss ◽  
Weighted Image ◽  
Phase Images ◽  
History Of

50-year-old man with a history of hepatitis C and cirrhosis Axial in-phase and out-of-phase 2D SPGR images (Figure 5.17.1) show a cirrhotic liver with moderate splenomegaly. The spleen contains multiple hypointense nodules that show signal loss on in-phase images relative to out-of-phase images. The low-signal-intensity lesions are also seen on axial fat-suppressed FSE T2-weighted image (...

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