Assessment of blue-stain resistance according to the EN 152 and a reverse test method using visual and computer-aided techniques

2006 ◽  
Vol 57 (4) ◽  
pp. 229-238 ◽  
Author(s):  
Jan Van den Bulcke ◽  
Joris Van Acker ◽  
Marc Stevens
Keyword(s):  
Test Method ◽  
Stain Resistance ◽  
Computer Aided ◽  
Blue Stain

Computer Aided Design of Ultrasonic Test by Numerical Simulation

2021 ◽  
Vol 1164 ◽  
pp. 97-104
Author(s):  
Réka Erdei ◽  
Zoltán Bézi ◽  
Csaba Takács
Keyword(s):  
Computer Aided Design ◽  
Grain Orientation ◽  
Ultrasonic Test ◽  
Probability Of Detection ◽  
Test Method ◽  
Dissimilar Metal ◽  
Computer Aided ◽  
Aided Design ◽  
The Given ◽  
Sophisticated Technology

Ultrasonic tests of dissimilar metal welds require extremely sophisticated technology. The complexity of the test is caused by the grain orientation and difficult accessibility of the weld and it is therefore necessary to redound the examinations by simulation. This study details some application possibilities of CIVA software and presents an example of the evaluation of the procedure used for the given test method with probability of detection curves.

Error Correction of Theory Model in Process-Stress Accelerated Test

2011 ◽  
Vol 311-313 ◽  
pp. 1677-1680
Author(s):  
Chun Sheng Guo ◽  
Qian Qian Du ◽  
Shi Wei Feng
Keyword(s):  
Activation Energy ◽  
Theoretical Model ◽  
Theoretical Data ◽  
Theory Model ◽  
Test Method ◽  
Accelerated Test ◽  
New Model ◽  
Computer Aided ◽  
Model Algorithm ◽  
Process Stress

To correct error in theoretical model of process-stress accelerated test, a new calculation method is proposed. The new method, based on computer-aided calculation, can significantly reduce the error of the model. Theoretical data is calculated using both the new model algorithm, which is the root test method, and the old model algorithm. The results show that the old model algorithm can generate error more than 13% in the activation energy and error more than 150% in the extrapolated lifetime (Q≤1.0eV), while the new model algorithm generates error less than 1% in activation energy, and error less than 4.1% in the extrapolated lifetime.

Strength testing of low-cost 3D-printed transtibial prosthetic socket

2021 ◽  
pp. 095441192110600
Author(s):  
Merel van der Stelt ◽  
Luc Verhamme ◽  
Cornelis H Slump ◽  
Lars Brouwers ◽  
Thomas JJ Maal
Keyword(s):  
Tensile Properties ◽  
Lower Limb ◽  
Low Cost ◽  
Test Method ◽  
Structural Testing ◽  
International Standard ◽  
Prosthetic Socket ◽  
Computer Aided ◽  
3D Printed ◽  
Lower Limb Prostheses

Measurement and production of traditional prosthetic sockets are time-consuming, labor-intensive, and highly dependent on the personnel involved. An alternative way to make prostheses is using computer-aided design (CAD) and computer-aided manufacturing (CAM). Fused Filament Fabrication (FFF) may be an alternative to make low-cost prosthetic sockets. This study investigates the tensile properties of potential printing materials suitable for FFF according to ISO527 (Standard Test Method for Tensile Properties of Plastics). To ensure that FFF-printed sockets are safe for patient usage, the structural integrity of the 3D-printed prosthesis will be investigated according to ISO10328 (International Standard Structural Testing of Lower Limb Prostheses). Tough PLA was the most suitable print material according to ISO 527 testing. The Tough PLA printed socket completed 2.27 million cycles and a static test target value of 4025 N. Future research remains necessary to continue testing new potential materials, improve print settings, and improve the socket design for the production of FFF-printed transtibial prosthetic sockets. FFF using Tough PLA can be used to create transtibial prostheses that almost comply with the International Standard for Structural Testing of Lower Limb Prostheses.

Formulations and a Computer-Aided Test Method for the Estimation of IMD Levels in an Envelope Feedback RFIC Power Amplifier

2012 ◽  
Vol 31 (12) ◽  
pp. 1881-1893 ◽  
Author(s):  
Nicolas G. Constantin ◽  
Kai H. Kwok ◽  
Hongxiao Shao ◽  
Cristian Cismaru ◽  
Peter J. Zampardi
Keyword(s):  
Power Amplifier ◽  
Test Method ◽  
Computer Aided ◽  
Computer Aided Test

An automated computational tool to study MRI safety of implanted passive cardiovascular medical devices

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Baretta ◽  
R Bursi ◽  
A Palazzin ◽  
L Emili
Keyword(s):  
Medical Device ◽  
Medical Devices ◽  
In Silico ◽  
Test Method ◽  
Rf Heating ◽  
Implantable Medical Devices ◽  
Web Based ◽  
Computer Aided ◽  
Simulation Results ◽  
Rf Energy

Abstract Introduction The absorption of radiofrequency (RF) energy during an MRI procedure may cause tissue heating in the vicinity of an implanted device, such as a stent or a stented valve, potentially causing patient harm. Computational modeling and simulation (M&S) can be used by medical device manufacturers to assess the RF-induced heating of implanted devices during an MRI scan and identify worst-case configurations within a given line of implants. However, despite the use of in-silico tools, a standard for in-silico testing of such problematic is still missing; The tool here proposed is a web-based application that automates the set-up and solution of RF-heating analysis, in line with existing standards for in-vitro testing. Methods The presented tool is part of a commercial web-based platform. The tool was developed in collaboration with the market leader of computer-aided engineering software and as part of a Research Collaboration Agreement with the American regulatory body. Commercial software was used to compute RF energy absorption and thermal heating of implantable medical devices replicating the directives of the ASTM F2182–11a Standard Test Method. The model is integrated in an automated workflow. Each simulation submitted by the user is sent to the cloud infrastructure for solution. Simulation results are stored in a database for later retrieval and report generation. Results The tool consists of a web-interface where the user can: i) upload the medical device computer-aided design (CAD) or select a simplified geometry from a library; ii) define the material properties of the device; ii) specify the desired input parameters specific to an MRI exposure scenario. Specifically, it is possible to study the device exposure: i) at different field frequencies (i.e., 64 MHz and 128 MHz); ii) at different powers (i.e., 2, 4 and 10 W/kg Whole body Specific Absorption Rate - SAR); iii) at different field polarizations (i.e., two circular and two linear); and iv) for different exposure time (i.e., form 240 s to 900 s). The presented tool allows the users to view and export results for each simulation, including electromagnetic fields, local SAR, and the temperature rise over time. Finally, the simulation results are summarized in an automatically generated report that follows regulatory guidance on M&S reporting. Conclusion The presented web-based M&S tool allows users to perform the thermal safety assessment of implantable medical devices during an MRI procedure following established good simulation practices. Minimal training or background in computer modeling is required to use the tool. Specific potential applications of the tool include RF-heating assessment of cardiovascular devices (e.g., stents, stented valves, stent retrievers). The proposed platform promotes the broader adoption of digital evidence in preclinical trials for RF safety analysis, supporting the device submission process and pre-market regulatory evaluation. Stent safety simulation result interface Funding Acknowledgement Type of funding source: None

scholarly journals EFFECTIVENESS OF COMPUTER AIDED INSTRUCTIONS (CAI) ON STUDENTS’ PERFORMANCE IN BASIC ELECTRICITY IN TECHNICAL COLLEGES IN RIVERS STATE OF NIGERIA

2017 ◽  
Vol 5 (11) ◽  
pp. 14-21
Author(s):  
Reagan N. Robinson
Keyword(s):  
Sample Size ◽  
Test Performance ◽  
Design Method ◽  
Technical Colleges ◽  
Sampling Technique ◽  
Test Method ◽  
Analysis Of Covariance ◽  
Significant Difference ◽  
Computer Aided ◽  
Rivers State

The study focused attention on the effectiveness of Computer Aided Instructions (CAI) on students’ performance in basic electricity in technical colleges in Rivers State. The study adopted the pretest posttest quasi experimental design method. The population of the study comprises of all the vocational I basic electricity students in the five technical colleges in Rivers State. They comprised of 93 students. Purposive sampling technique was used to select two Government Technical Colleges and a sample size of 60 students was randomly selected for the study. This sample size comprised of 30 males and 30 females. The research instrument used for the study was the Basic Electricity Test (BET). The instrument was validated by two lecturers from technical education department of IgnatusAjuru University of Education Port Harcourt. The reliability of the instrument was done using test-re-test method and Pearson’s product moment correlation was used to obtain a coefficient of 0.65. Two research questions were drawn and two hypotheses were formulated for the study at 0.05 level of significance. The data for the study were analyzed using Mean and Analysis of Covariance (ANCOVA). The result indicated that students taught using Computer Aided Instructions (CAI) performed significantly better than those taught using conventional method. Also, there was no significant difference in the post test performance scores of male and female students. Some recommendations were made from the findings.

scholarly journals Improving the Mould and Blue-Stain-Resistance of Bamboo through Acidic Hydrolysis

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 244
Author(s):  
Zixuan Yu ◽  
Xiaofeng Zhang ◽  
Rong Zhang ◽  
Yan Yu ◽  
Fengbo Sun
Keyword(s):  
Weight Loss ◽  
Citric Acid ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Colour Change ◽  
Soluble Carbohydrates ◽  
Acidic Hydrolysis ◽  
Stain Resistance ◽  
Starch Grain ◽  
Blue Stain

Bamboo is much more easily attacked by fungus compared with wood, resulting in shorter service life and higher loss in storage and transportation. It has been long accepted that the high content of starch and sugars in bamboo is mainly responsible for its low mould resistance. In this paper, acetic acid, propionic acid, oxalic acid, citric acid, and hydrochloric acid were adopted to hydrothermally hydrolyze the starch in bamboo, with the aims to investigate their respective effect on the mould and blue-stain resistance of bamboo, and the optimized citric acid in different concentrations were studied. The starch content, glucose yields, weight loss, and colour changes of solid bamboo caused by the different acidic hydrolysis were also compared. The results indicated that weak acidic hydrolysis treatment was capable of improving mould-resistant of bamboo. The mould resistance increased with the increased concentration of citric acid. Bamboo treated with citric acid in the concentration of 10% could reduce the infected area ranging to 10–17%, the growth rating of which could reach 1 resistance. The content of soluble sugar and starch remained in bamboo decreased significantly from 43 mg/g to 31 mg/g and 46 mg/g to 23 mg/g, respectively, when the citric acid concentration varied from 4% to 10%. Citric acid treatments of 10% also caused a greatest surface colour change and weight loss. The results in this study demonstrated citric acid treatment can effectively reduce the starch grain and soluble sugars content and improve mould resistance of bamboo, which can be attributed to the reduction of starch grain and soluble carbohydrates (such as glucose, fructose, and sucrose, etc.) in bamboo.

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