Effect determination of operating environments on growth of subfilm corrosion of machine parts with dispersion-filled polymer coatings

2021 ◽  
Vol 0 (8) ◽  
pp. 34-41
Author(s):  
V. A. Gabysheva ◽  
◽  
N. I. Baurova ◽  
Keyword(s):  
Growth Rate ◽  
Polymer Coating ◽  
Polymer Coatings ◽  
Detection Methods ◽  
Good Adhesion ◽  
Organosilicon Polymer ◽  
Operating Environments ◽  
Study Results ◽  
Machine Parts

Detection methods of subfilm corrosion as well as the effect of operating environments on the corrosion growth rate have been examined. The study results of the effect of operating environments on parts with organosilicon polymer coatings modified with various dispersed fillers are presented. It is shown that the addition of mica into the composition of an organosilicon coating make possible to have a protective anticorrosion coating with good adhesion to the metal surface. The effect of operating environments on wettability of the polymer coating surface is described.

scholarly journals Analysis: Particulate Limits for Intravascular Devices: Considerations for Polymer Coating Embolism

2019 ◽  
Vol 53 (6) ◽  
pp. 426-432 ◽  
Author(s):  
Amitabh Madhukumar Chopra
Keyword(s):  
Polymer Coating ◽  
Animal Studies ◽  
Polymer Coatings ◽  
Medical Instrumentation ◽  
New Device ◽  
Iatrogenic Complication ◽  
Industry Standard ◽  
Step Procedure ◽  
Release Limits ◽  
Intravascular Devices

Abstract Lubricious polymer coatings are increasingly used on intravascular devices to facilitate easier access and navigation through tortuous blood vessels. Recent reports highlight the separation and downstream embolism of polymer particles affecting the vasculature and various organs. The Food and Drug Administration (FDA) acknowledges polymer coating embolism as an iatrogenic complication of intravascular devices and continues to close gaps in standards related to coating integrity. The Association for the Advancement of Medical Instrumentation established particulate testing as an industry standard for evaluating coating integrity of intravascular devices. The FDA recognizes this standard; however, challenges exist in setting particulate limits that may compromise device function without sufficient clinical data. The microscopic nature of polymer emboli not visible with available imaging modalities has impacted reporting. This has also resulted in a reduced number of manufacturer-driven product development projects related to coating integrity. On the other hand, recent procedural trends have supported the innovation of coated devices with expanded indications, requiring particulate evaluations and release limits. This article proposes a methodology to set particulate limits for intravascular devices given existing clinical, regulatory, and manufacturing challenges. The approach with standardization requirements enables characterization, comparison, and evaluation of lubricious coatings from various manufacturers. It incorporates a step-by-step procedure that adds scrutiny to the application of coatings while ensuring device function is not impacted. Together with particulate assessments, clinicopathologic and animal studies permit an understanding of particulate ranges from commercially available devices and setting of particulate limits for new device evaluations.

Determination of the Growth Rate of Hydrothermally Synthesised ZnO2 Crystallites

2017 ◽  
Vol 50 ◽  
pp. 41-47 ◽  
Author(s):  
Martin Egblewogbe ◽  
Garu Gebreyesus ◽  
Samuel A. Atarah
Keyword(s):  
Growth Rate ◽  
Zinc Acetate Dihydrate ◽  
Hydrothermal Process ◽  
Growth Rate Constant ◽  
Acetate Dihydrate ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Zinc Peroxide

Powders consisting of nanoparticles of zinc peroxide were prepared via a simple hydrothermal process using zinc acetate dihydrate and hydrogen peroxide precursors. The size of the crystallites was determined using x-ray powder diffraction. Over a period of 5 hours the crystallite radius increased from 4 nm – 9 nm at a temperature of 68 °C ± 5 °C, with growth rate constant of 0.23 nm3 min−1 calculated using the Lifshitz, Slyozov, and Wagner model. The powders were further characterised with High Resolution Transmission Electron Microscopy, Energy Dispersive X-ray analysis, and Small Angle X-ray Scattering, showing well-crystallised ZnO2 nanoparticles.

High Frequency Ultrasonic Measurements

1988 ◽  
Vol 21 (5) ◽  
pp. 133-136
Author(s):  
N Zarsav
Keyword(s):  
High Frequency ◽  
Polymer Coating ◽  
Steel Sheet ◽  
Lamb Waves ◽  
Thin Plates ◽  
Design Features ◽  
Degree Of Cure ◽  
Double Probe ◽  
Ultrasonic Measurements

The use of high frequency ultrasonic Lamb waves to measure the thickness of thin plates and foils, is discussed and the feasibility of their application to the determination of the degree of cure of polymer coating on coated tin plated steel sheet (as used by the food can industry) is evaluated. The paper also discusses briefly the design features of the purpose built precision double probe ultrasonic goniometer used to carry out these measurements.

Contribution of satellite altimetry in modelling Moho density contrast in oceanic areas

2019 ◽  
Vol 13 (1) ◽  
pp. 33-40 ◽  
Author(s):  
M. Abrehdary ◽  
L. E. Sjöberg ◽  
D. Sampietro
Keyword(s):  
Satellite Altimetry ◽  
Density Contrast ◽  
Contrast Model ◽  
Bathymetric Data ◽  
Crustal Model ◽  
Marine Gravity ◽  
Study Results ◽  
Vening Meinesz ◽  
Satellite Altimetry Data

Abstract The determination of the oceanic Moho (or crust-mantle) density contrast derived from seismic acquisitions suffers from severe lack of data in large parts of the oceans, where have not yet been sufficiently covered by such data. In order to overcome this limitation, gravitational field models obtained by means of satellite altimetry missions can be proficiently exploited, as they provide global uniform information with a sufficient accuracy and resolution for such a task. In this article, we estimate a new Moho density contrast model named MDC2018, using the marine gravity field from satellite altimetry in combination with a seismic-based crustal model and Earth’s topographic/bathymetric data. The solution is based on the theory leading to Vening Meinesz-Moritz’s isostatic model. The study results in a high-accuracy Moho density contrast model with a resolution of 1° × 1° in oceanic areas. The numerical investigations show that the estimated density contrast ranges from 14.2 to 599.7 kg/m3 with a global average of 293 kg/m3. In order to evaluate the accuracy of the MDC2018 model, the result was compared with some published global models, revealing that our altimetric model is able to image rather reliable information in most of the oceanic areas. However, the differences between this model and the published results are most notable along the coastal and polar zones, which are most likely due to that the quality and coverage of the satellite altimetry data are worsened in these regions.

scholarly journals A New Method for Determination of Joint Roughness Coefficient of Rock Joints

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Shigui Du ◽  
Huicai Gao ◽  
Yunjin Hu ◽  
Man Huang ◽  
Hua Zhao
Keyword(s):  
Scale Effect ◽  
Fractal Model ◽  
Rock Joints ◽  
Effective Length ◽  
Roughness Coefficient ◽  
Joint Roughness Coefficient ◽  
Joint Roughness ◽  
Exposed Rock ◽  
Study Results

The joint roughness coefficient (JRC) of rock joints has the characteristic of scale effect. JRC measured on small-size exposed rock joints should be evaluated by JRC scale effect in order to obtain the JRC of actual-scale rock joints, since field rock joints are hardly fully exposed or well saved. Based on the validity analysis of JRC scale effect, concepts of rate of JRC scale effect and effective length of JRC scale effect were proposed. Then, a graphic method for determination of the effective length of JRC scale effect was established. Study results show that the JRC of actual-scale rock joints can be obtained through a fractal model of JRC scale effect according to the statistically measured results of the JRC of small-size partial exposed rock joints and by the selection of fractal dimension of JRC scale effect and the determination of effective length of JRC scale effect.

scholarly journals Biosensors for the Determination of SARS-CoV-2 Virus and Diagnosis of COVID-19 Infection

2022 ◽  
Vol 23 (2) ◽  
pp. 666
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Chien-Fu Chen ◽  
Urte Samukaite-Bubniene ◽  
...  
Keyword(s):  
Current Trend ◽  
Analytical Signal ◽  
Diagnostic Methods ◽  
Detection Methods ◽  
Label Free ◽  
Free Mode ◽  
Rna Hybridisation ◽  
Antigen Antibody ◽  
Affinity Interaction

Monitoring and tracking infection is required in order to reduce the spread of the coronavirus disease 2019 (COVID-19), induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To achieve this goal, the development and deployment of quick, accurate, and sensitive diagnostic methods are necessary. The determination of the SARS-CoV-2 virus is performed by biosensing devices, which vary according to detection methods and the biomarkers which are inducing/providing an analytical signal. RNA hybridisation, antigen-antibody affinity interaction, and a variety of other biological reactions are commonly used to generate analytical signals that can be precisely detected using electrochemical, electrochemiluminescence, optical, and other methodologies and transducers. Electrochemical biosensors, in particular, correspond to the current trend of bioanalytical process acceleration and simplification. Immunosensors are based on the determination of antigen-antibody interaction, which on some occasions can be determined in a label-free mode with sufficient sensitivity.

scholarly journals Measuring driver cognitive distraction through lips and eyebrows

2022 ◽  
Vol 12 (1) ◽  
pp. 756
Author(s):  
Afizan Azman ◽  
Mohd. Fikri Azli Abdullah ◽  
Sumendra Yogarayan ◽  
Siti Fatimah Abdul Razak ◽  
Hartini Azman ◽  
...  
Keyword(s):  
Facial Expression ◽  
Bayesian Network ◽  
Dynamic Bayesian Network ◽  
Detection Methods ◽  
Support Vector ◽  
Head Orientation ◽  
Strongly Correlated ◽  
Physiological Measurement ◽  
Cognitive Distraction ◽  
Study Results

<span>Cognitive distraction is one of the several contributory factors in road accidents. A number of cognitive distraction detection methods have been developed. One of the most popular methods is based on physiological measurement. Head orientation, gaze rotation, blinking and pupil diameter are among popular physiological parameters that are measured for driver cognitive distraction. In this paper, lips and eyebrows are studied. These new features on human facial expression are obvious and can be easily measured when a person is in cognitive distraction. There are several types of movement on lips and eyebrows that can be captured to indicate cognitive distraction. Correlation and classification techniques are used in this paper for performance measurement and comparison. Real time driving experiment was setup and faceAPI was installed in the car to capture driver’s facial expression. Linear regression, support vector machine (SVM), static Bayesian network (SBN) and logistic regression (LR) are used in this study. Results showed that lips and eyebrows are strongly correlated and have a significant role in improving cognitive distraction detection. Dynamic Bayesian network (DBN) with different confidence of levels was also used in this study to classify whether a driver is distracted or not.</span>

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