scholarly journals Viscous Fingering of Miscible Liquids in Porous and Swellable Media for Rapid Diagnostic Tests

2018 ◽  
Vol 5 (4) ◽  
pp. 94
Author(s):  
Holly Clingan ◽  
Devon Rusk ◽  
Kathryn Smith ◽  
Antonio Garcia
Keyword(s):  
Saliva Sample ◽  
Fluid Motion ◽  
Test Strip ◽  
Viscous Fingering ◽  
Test Method ◽  
Colorimetric Test ◽  
Significant Movement ◽  
Miscible Liquids ◽  
Korteweg Stresses ◽  
Kinetics Of

In lateral flow and colorimetric test strip diagnostics, the effects of capillary action and diffusion on speed and sensitivity have been well studied. However, another form of fluid motion can be generated due to stresses and instabilities generated in pores when two miscible liquids with different densities and viscosities come into contact. This study explored how a swellable test pad can be deployed for measuring urea in saliva by partially prefilling the pad with a miscible solution of greater viscosity and density. The resultant Korteweg stresses and viscous fingering patterns were analyzed using solutions with added food color through video analysis and image processing. Image analysis was simplified using the saturation channel after converting RGB image sequences to HSB. The kinetics of liquid mixing agreed with capillary displacement results for miscible liquids undergoing movement from Korteweg stresses. After capillary filling, there was significant movement of liquid due to these fluidic effects, which led to mixing of the saliva sample with an enzyme test solution. Owing to the simplicity and speed of this test method, urea can be analyzed with an electronic nose over a useful range for detecting salivary urea concentration for rapid and early detection of dehydration.

ASTM E 1559 Method for Measuring Material Outgassing/Deposition Kinetics

1995 ◽  
Vol 38 (1) ◽  
pp. 19-28
Author(s):  
J. Garrett ◽  
A. Glassford ◽  
J. Steakley
Keyword(s):  
Air Force ◽  
High Vacuum ◽  
Standard Test ◽  
Test Method ◽  
Deposition Kinetics ◽  
Standard Test Method ◽  
Typical Data ◽  
American Society ◽  
Kinetics Of ◽  
Measurement Approach

The American Society for Testing and Materials (ASTM) has published a new standard test method for characterizing time and temperature dependence of material outgassing kinetics and the deposition kinetics of outgassed species on surfaces at various temperatures. This new ASTM standard, E 1559,1 uses the quartz crystal microbalance (QCM) collection measurement approach. The test method was originally developed under a program sponsored by the U.S. Air Force Materials Laboratory to create a standard test method for obtaining outgassing and deposition kinetics data for spacecraft materials. Standardization by ASTM recognizes that the method has applications beyond aerospace. In particular, the method will provide data of use to the electronics, semiconductor, and high vacuum industries. This paper describes the ASTM E 1559 test method and presents some typical data. the paper also describes the Lockheed ASTM E 1559 test apparatus.

116 Colorimetric Test Method for Oil Contamination

2009 ◽  
Vol 2009.8 (0) ◽  
pp. 74-78
Author(s):  
Akira Sasaki ◽  
Hideo Aoyama ◽  
Tomomi Honda ◽  
Yoshiro Iwai
Keyword(s):  
Test Method ◽  
Oil Contamination ◽  
Colorimetric Test

scholarly journals Use of Colorimetric Test Strips for Monitoring the Effect of Hemodialysis on Salivary Nitrite and Uric Acid in Patients with End-Stage Renal Disease: A Proof of Principle

2008 ◽  
Vol 54 (9) ◽  
pp. 1473-1480 ◽  
Author(s):  
Timothy M Blicharz ◽  
David M Rissin ◽  
Michaela Bowden ◽  
Ryan B Hayman ◽  
Christopher DiCesare ◽  
...  
Keyword(s):  
Uric Acid ◽  
Renal Disease ◽  
End Stage Renal Disease ◽  
Test Strip ◽  
Initial Screening ◽  
Test Strips ◽  
Colorimetric Test ◽  
Stage Renal Disease ◽  
End Stage ◽  
Esrd Patients

Abstract Background: Initial screening of potential biomarkers for monitoring dialysis was performed with saliva samples collected from patients with end-stage renal disease (ESRD). A more thorough analysis of the most promising markers identified in the initial screening was conducted with saliva samples acquired at hourly intervals throughout dialysis to monitor analyte concentrations as dialysis progressed. We observed that salivary nitrite (NO2−) and uric acid (UA) concentrations consistently decreased as dialysis proceeded. Methods: Solution-based colorimetric-detection chemistries for NO2− and UA were converted to a test strip format to produce a simple method for semiquantitatively measuring NO2− and UA concentrations in the clinic or at the patient’s home. We assessed the test strips with saliva samples collected from both ESRD patients undergoing dialysis and healthy control volunteers to qualitatively monitor the effect of dialysis on salivary NO2− and UA. We used computer software to analyze digital images of the resulting test strip color intensities. Results: Test strip measurements showed that mean salivary concentrations of NO2− and UA were decreased in ESRD patients by 86% and 39%, respectively, compared with 15% and 9% for time-matched controls. Comparison of test strip results with calibrated solution-based assays suggests that the test strips can semiquantitatively measure salivary concentrations of NO2− and UA. Conclusions: The colorimetric test strips monitored changes in salivary NO2− and UA concentrations that occurred in ESRD patients during dialysis. The test strips may prove useful for noninvasively evaluating dialysis progress and may also be useful for monitoring renal disease status.

Altered kinetics of contraction of mouse atrial myocytes expressing ventricular myosin regulatory light chain

1999 ◽  
Vol 276 (4) ◽  
pp. H1167-H1171 ◽  
Author(s):  
Scott H. Buck ◽  
Patrick J. Konyn ◽  
Joseph Palermo ◽  
Jeffrey Robbins ◽  
Richard L. Moss
Keyword(s):  
Light Chain ◽  
Creatine Phosphate ◽  
Regulatory Light Chain ◽  
Test Method ◽  
Cardiac Contraction ◽  
Myosin Regulatory Light Chain ◽  
Wild Type ◽  
Shortening Velocity ◽  
Atrial Cells ◽  
Kinetics Of

To investigate the role of myosin regulatory light chain isoforms as a determinant of the kinetics of cardiac contraction, unloaded shortening velocity was determined by the slack-test method in skinned wild-type murine atrial cells and transgenic cells expressing ventricular regulatory light chain (MLC2v). Transgenic mice were generated using a 4.5-kb fragment of the murine α-myosin heavy chain promoter to drive high levels of MLC2v expression in the atrium. Velocity of unloaded shortening was determined at 15°C in maximally activating Ca2+ solution (pCa 4.5) containing (in mmol/l) 7 EGTA, 1 free Mg2+, 4 MgATP, 14.5 creatine phosphate, and 20 imidazole (ionic strength 180 mmol/l, pH 7.0). Compared with the wild type ( n = 10), the unloaded shortening velocity of MLC2v-expressing transgenic murine atrial cells ( n = 10) was significantly greater (3.88 ± 1.19 vs. 2.51 ± 1.08 muscle lengths/s, P < 0.05). These results provide evidence that myosin light chain 2 regulates cross-bridge cycling rate. The faster rate of cycling in the presence of MLC2v suggests that the MLC2v isoform may contribute to the greater power-generating capabilities of the ventricle compared with the atrium.

scholarly journals RapidChek SELECTTMSalmonella Enteritidis Test System for the Detection of Salmonella Enteritidis in Poultry House Drag Swabs, Shell Egg Pools, and Chicken Carcass Rinsates

2011 ◽  
Vol 94 (4) ◽  
pp. 1138-1153 ◽  
Author(s):  
Mark T Muldoon ◽  
Verapaz Gonzalez ◽  
Meredith I Sutzko ◽  
Ann-Christine Olsson Allen ◽  
Samantha Creamer ◽  
...  
Keyword(s):  
Salmonella Enteritidis ◽  
Reference Method ◽  
Test Strip ◽  
Test System ◽  
Test Method ◽  
Poultry House ◽  
Chicken Carcass ◽  
Two Samples ◽  
Secondary Enrichment ◽  
Inspection Service

Abstract The RapidChek SELECTTMSalmonella Enteritidis Test System was validated for the detection of Salmonella Enteritidis (SE) in poultry house drag swabs, shell egg pools, and chicken carcass rinsates. The method utilizes RapidChek SELECTTMSalmonella (AOAC PTM License No. 080601) proprietary primary and secondary enrichment media. Following enrichment, an immunochromatographic test strip is inserted into the tube containing the secondary enrichment broth, developed for 10 min, and interpreted. Salmonella Enteritidis-inoculated samples (1–5 CFU SE/analytical unit) were tested by the test method as well as the appropriate cultural reference method U.S. Food and Drug Administration-Bacteriological Analytical Manual (drag swabs and egg pools) or U.S. Department of Agriculture-Food Safety and Inspection Service (chicken carcass rinsates). A total of 80 samples were tested by both methods in the study. Fifty-two samples were positive by the RapidChek SELECT Salmonella Enteritidis method and 38 were found positive by the respective reference method. The sensitivity of the method was 100% and the specificity was 100%. The accuracy of the test method was 137%, indicating that the method was more sensitive than the reference method. The RapidChek SELECT Salmonella Enteritidis method was tested with 82 Salmonella Group D1 strains including 63 Salmonella Enteritidis strains as well as 32 non-Salmonella Group D1 strains representing 10 bacteria genera. The test method detected all 82 Group D1 strains (100% sensitivity). None of the non-Salmonella Group D1 or other genera of bacteria were detected, indicating a specificity of 100%. The method was shown to be highly robust and stable under control and accelerated stability conditions.

Wettability-Based Colorimetric Test Strips for Gasoline/Oil Mixture Differentiation

2015 ◽  
Vol 1105 ◽  
pp. 331-334 ◽  
Author(s):  
Shuang Qiu ◽  
Michael Chung Kay Wong ◽  
Paul Chi Hang Li
Keyword(s):  
Vapor Deposition ◽  
Low Cost ◽  
Engine Performance ◽  
Chemical Vapor ◽  
Test Strip ◽  
Inverse Opal ◽  
Opal Film ◽  
Colorimetric Test ◽  
Oil Mixtures

As inspired by the pH paper for the determination of the acidity levels of solutions, we have developed a wettability-based colorimetric test strip to differentiate the composition of gasoline/oil mixtures. These mixtures are widely used in two-stroke motor engines. A method that is rapid, low cost and simple-to-use will facilitate the differentiation of these gasoline/oil mixtures, and ensure the use of these mixtures in the proper ratios in two-stroke engines for optimized engine performance and endurance. An inverse opal film (IOF) consisting of nanopores was synthesized on the silicon strips. These strips were then functionalized with alkysilanes through chemical vapor deposition. Based on the observation that the silanized nanopores are wetted or not wetted by the gasoline/oil mixtures, we are able to differentiate between the 16:1 and 1:1 mixtures.

Viscous Fingering in Miscible Liquids under Microgravity Conditions

2001 ◽  
Vol 13 (9) ◽  
pp. S12-S12 ◽  
Author(s):  
A. A. Vedernikov ◽  
B. Scheid ◽  
E. Istasse ◽  
J. C. Legros
Keyword(s):  
Viscous Fingering ◽  
Microgravity Conditions ◽  
Miscible Liquids
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