Effect of smartphone camera settings in colorimetric measurements under controlled illumination

An analysis was performed of various estimates of the adiabatic temperature Ttot that corresponds to the total heat liberated by a gas dose adsorbed on a metal film in the calorimeter for measurement of chemisorption enthalpies. Besides the two common procedures consisting either in the construction of the adiabatic temperature-time curve or in the extrapolation of the single-exponential cooling part of the actual temperature-time curve to zero time, we have examined estimates of Ttot by extrapolating the cooling exponential to the mid-point between zero time and the temperature maximum (t = tmax/2). Model calculations have shown the merit of the latter extrapolation, particularly in the cases of slow heat evolution. This has been verified on the data measured in the chemisorption of methane and ethane on molybdenum films. Extrapolation to tmax/2 has turned out to be a simple and reasonably reliable procedure for handling the data obtained in film calorimeters.

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Chemical Degradation and Color Changes of Paint Protective Coatings Used in Solar Glass Mirrors

Coatings ◽

10.3390/coatings11040476 ◽

2021 ◽

Vol 11 (4) ◽

pp. 476

Author(s):

Mohamed Guerguer ◽

Sanae Naamane ◽

Zineb Edfouf ◽

Olivier Raccurt ◽

Hassan Bouaouine

Keyword(s):

Protective Coatings ◽

Natural Aging ◽

Attenuated Total Reflection ◽

Chemical Degradation ◽

Complete Analysis ◽

Color Changes ◽

Colorimetric Measurements ◽

Marine Site ◽

Service Conditions ◽

Paint Coatings

This paper reports a study of the influence of outdoor natural aging on paint coatings applied to the back of three commercial solar glass mirrors (A1, C2, and D2) under two different exposure environments (marine and desert) in Morocco for a period of about three years. The aging assessment was carried out through colorimetric measurements and FTIR-ATR (Attenuated total reflection-Fourier transform infrared) analyses of the top coat paints. The obtained results demonstrate that the tested coating system had a high resistance at the desert site. Under the desert environment, no obvious changes to the coating occurred after 350 days. However, at the marine site, some color changes were detected, and the coating got yellow and more matte, especially for mirror A1. FTIR-ATR analyses have indicated many modifications in the intensity of many bonds of infrared spectra especially for paint of this mirror type (A1). This chemical degradation is not only due to UV degradation but also related to many factors, such as humidity, salinity, and rainfall. This finding was concluded after the faster degradation observed on samples exposed at the marine site. The present study confirms the need to use different exposure environments for testing the limits of new protective systems for solar glass mirrors rather than using only the real service conditions. Finally, accelerated tests are necessary for understanding the effect of each degrading parameter and their results should be compared to outdoor tests data for a complete analysis of coatings durability.

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Methodology for irrigation water uptake time estimation based on RGB colorimetric measurements of leaves (A visual-graphical observation)

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1031/1/012016 ◽

2021 ◽

Vol 1031 (1) ◽

pp. 012016

Author(s):

S Atanasov

Keyword(s):

Water Uptake ◽

Irrigation Water ◽

Time Estimation ◽

Colorimetric Measurements

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Nanotechnology in Roman Opaque Red Glass from the 2nd Century AD. Archaeometric Investigation in Red Sectilia from the Decoration of the Lucius Verus Villa in Rome

Heritage ◽

10.3390/heritage2030159 ◽

2019 ◽

Vol 2 (3) ◽

pp. 2597-2611 ◽

Cited By ~ 1

Author(s):

Mario Bandiera ◽

Patrice Lehuédé ◽

Marco Verità ◽

Luis Alves ◽

Isabelle Biron ◽

...

Keyword(s):

Chemical Composition ◽

Chemical Characterization ◽

Second Step ◽

Colorimetric Analysis ◽

Historical Sources ◽

Pixe Analysis ◽

X Ray ◽

Colorimetric Measurements ◽

Shed Light

This work aims to characterise the chemical composition of Roman opaque red glass sectilia dated to the 2nd century A.D and to shed light on Roman glassmaking production of different shades of red, from red to reddish-brown. Due to the lack of technical historical sources for this period many questions about technological aspects still remain. In this project a multi-disciplinary approach is in progress to investigate the red glass sectilia with several red hues from the Imperial Villa of Lucius Verus (161–169 A.D.) in Rome. First, colorimetric measurements were taken to identify the various red hues. The second step was chemical characterization of the samples and the identification of crystalline colouring phases. Particle Induced X-Ray Emission (PIXE) analysis was used to investigate the chemical composition of these glass samples, while the crystalline phases were identified by Raman Spectroscopy and Scanning Electrons Microscope with Energy Dispersive X-ray Spectrometry (SEM-EDS). Using SEM-EDS nanoparticles were detected as a colouring agent, the chemical composition and the morphology of which has been studied in depth. This information has been compared with the colorimetric analysis to establish any correlation with the different colour hues.

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The effect of hematocrit on the results of measurements using glucose meters based on different techniques

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm.2011.770 ◽

2012 ◽

Vol 50 (2) ◽

Cited By ~ 5

Author(s):

Bogdan Solnica ◽

Jan Skupien ◽

Beata Kusnierz-Cabala ◽

Krystyna Slowinska-Solnica ◽

Przemyslaw Witek ◽

...

Keyword(s):

Glucose Concentration ◽

Repeated Measures ◽

Glucose Dehydrogenase ◽

Venous Blood ◽

Measurement Techniques ◽

Blood Samples ◽

Dehydrogenase Reaction ◽

Wide Range ◽

Colorimetric Measurements ◽

Glucose Meter

AbstractThe aim of the study was to evaluate the effect of hematocrit (HCT) on glucose meter assays based on different measurement techniques.This paper studied glucose meters utilizing the glucose dehydrogenase reaction and four measurement techniques: colorimetry (HemoCue), reflectometry (Accu-Chek Active), amperometry (Optium Xido) and coulometry (Optium Omega). The EDTA venous blood samples HCT were modified by adding or removing defined aliquots of plasma. Glucose concentration was measured using each meter in 27 batches of blood samples, with HCT ranging from 20% to 60% in 10% increments. The data were analyzed using repeated measures models and a linear random effects model.A significant relationship between HCT and glucose reading in all meters was found and, for all meters except Optium Xido, there was a significant modification of this relationship by glucose level. The relative decrease in glucose concentration per 1% increase of the HCT value varied from 0.30% for Optium Omega in samples with glucose concentrations <5.55 mmol/L to 1.37% for Optium Xido in the same stratum (p<0.0001). The 5% glucose meter error (the ADA recommendation) was reached in the <5.55 mmol/L stratum after HCT change by 3.9%–16.7%.There is a significant continuous effect of HCT on measurement accuracy of glucose meters across its wide range of values and glucose concentrations. The most sensitive to the HCT interference was the system utilizing amperometric technique (Optium Xido) followed by the one with reflectometric technique (Accu-Chek Active), while the systems with the coulometric technique (Optium Omega) or colorimetric measurements in whole blood haemolysate (HemoCue) were less sensitive.

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RESEARCH OF DIGITAL CAMERA DYNAMIC RANGE ON THE IMAGING PROCESSING BASIS

Devices and Methods of Measurements ◽

10.21122/2220-9506-2017-8-3-271-278 ◽

2017 ◽

Vol 8 (3) ◽

pp. 271-278

Author(s):

M Sutkowski ◽

Ya. N. Saukova

Keyword(s):

Dynamic Range ◽

Digital Camera ◽

Measuring Channel ◽

Blue Color ◽

Lower And Upper Bounds ◽

Color Target ◽

Color Channel ◽

Imaging Processing ◽

Colorimetric Measurements ◽

Target Sets

Digital images provide to determine photometric and colorimetric properties of objects subject to validation all elements of a measuring channel (digital camera, software, display) and solve the problem of their limited dynamic ranges. The aim of the study was to explore the dynamic range of a digital camera for use in photometric and colorimetric measurements.The Laboratory of Photonics at the Institute of Microelectronics and Optoelectronics (Warsaw Technical University, Poland) conducted a comparative experiment to determine the threshold of sensitivity, linearity and range of application the digital camera. Color target sets with certified brightness and chromaticity were created at the terminals and recorded with a digital camera with different exposure times. The authors propose a method to extend the dynamic range of a digital camera for red, green and blue color channel of intensities by pairing the calibration dependencies, and determine the true brightness and color of a point on the object by calculation.Calibration dependencies (triads) of digital camera for red, green and blue color channels intensities were constructed. These dependences allow determining lower and upper bounds of the dynamic range. Each triad has a form of the hysteresis loop. The experiment showed that the accuracy of this method is ± 3–5 %.

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