A Comparison of Two Different Light Booths for Measuring Color Difference of Metameric Pairs

A standardized source of light is essential for visual color assessments, which is why lighting booths were developed. For the best results in visual assessment, it is important to consider the right choice of light source, the right viewing conditions, and the variability of the viewer. To date, many light booth technologies have been introduced to meet user demands. Since most of the light sources on the market are characterized by the designer or manufacturer, the resulting variations from booth-to-booth remain. In this study, we compared the performance of two standard light booths to assess the color difference of eleven metameric pairs. In this study, we checked an earlier technology-based light booth that is still used in the textile industry and contains illuminant A (Tungsten lamp) with CCT 2700 K, TL84 (tri-band fluorescent tube) with CCT 4000 K, and simulator D65 (CCT 6500 K) with a different light booth whose original light sources have been replaced by currently available LED retro kits from equivalent CCTs. As an inexperienced customer or industrial user, our question was, how important is this replacement? The results revealed that two different standard lighting technologies with similar CCTs cannot reproduce the same estimates because the light sources produced different SPDs. It is illustrating that caution is necessary when comparing results obtained from two different light booths containing light sources with similar CCTs but different SPDs. This comparative study suggested that the variability of the light sources’ SPDs or the observer or the sample should be modeled considering light booth’s technology to estimate its contribution to the overall variability. The close relationship between perceived and CAM02-UCS suggests that if both booths are used after the light sources have been calibrated, a formula based on color appearance models must be used to predict color appearance. To obtain better agreement between perceived and calculated color difference, one must need to avoid light booths with nominally white light sources.

Microfluidic Devices with Selectable Optical Pathlength for Quality Control of Alcoholic Solutions

In this work, we present a micro-opto-fluidic platform for the analytical testing of alcoholic solutions (isopropyl alcohol, also known as isopropanol, and ethylene glycol) based on their absorption properties in the wavelength region 1.0–1.7 μm. The investigated fluidic channel is a rectangular glass microcapillary externally coated with aluminum layers, to create a zig-zag guiding effect for the radiation provided by a tungsten lamp. Light crosses the capillary multiple times before being directed towards an optical spectrum analyzer; thanks to the enhanced optical path-length inside the sample, the measurement sensitivity is strongly increased. Preliminary experimental results are reported to show sensing performances.

A NIR-Spectroscopy-Based Approach for Detection of Fluids in Rectangular Glass Micro-Capillaries

In this work, we present a micro-opto-fluidic platform to distinguish water and alcohol samples flowing in rectangular glass micro-capillaries laid onto a bulk Aluminum mirror illuminated by the broadband radiation emitted by a Tungsten lamp. The fluid detection is based on the spectral analysis of the light reflected by the micro-structure in the near-infrared region from 1.0 μm to 1.7 μm. A theoretical model was implemented to study light propagation in the channel, taking into account absorption effects, and the results of the simulation are in good agreement with the experimental spectra obtained by testing water, ethanol, isopropanol and ethylene glycol.

Preparation of 2-Arylquinolines from 2-Arylethyl Bromides and Aromatic Nitriles with Magnesium and N-Iodosuccinimide

Treatment of 2-arylethylmagnesium bromides, prepared from 2-arylethyl bromides and magnesium, with aromatic nitriles, followed by reaction with water and then with N-iodosuccinimide under irradiation with a tungsten lamp, gave the corresponding 2-arylquinolines in good to moderate yields under transition-metal-free conditions. 2-Alkylquinolines could be also obtained in moderate yields by the same procedure with 2-arylethyl bromides, magnesium, aliphatic nitriles­ bearing a secondary alkyl group, and N-iodosuccinimide.

FINGER PRINTING ANALYSIS OF THE PHENOLS FROM PERGULARIA DAEMIA FORSK PLANT LEAVES AND STEM USING HPTLC

The research study was carried out to identify the phenols from methanol extracts (MPD) of medicinally and efficiently useful leaves and stem of Pergularia daemia (Forsk) plant using High Performance Thin Layer Chromatography (HPTLC) technique. Preliminary phytochemical screening was done and HPTLC studies were carried out. Densitometry scanning was performed in the reflectance absorbance mode at 540 nm and operated by Win CATS software with the help of tungsten lamp. Preliminary phytochemical screening of methanol extract of P. daemia shows the presence of alkaloids, glycosides, flavonoids, phenols and carbohydrates. HPTLC finger printing of phenols of methanolic extract of leaf and stem revealed eleven polyvalent phytoconstituents (13 and 10 peaks) and corresponding ascending order of Rf values in the range from 0.08 to 0.65 in leaf and 0.02 to 0.66 in the stem. From the result of preliminary phytochemical analysis and above Rf values from HPTLC, we have concluded the presence of phenols in methanol extracts.

ДОСЛІДЖЕННЯ ВПЛИВУ ПЕРЕПЛЕТЕННЯ НА СВІТЛОСТІЙКІСТЬ ЗАБАРВЛЕНЬ БАВОВНЯНОГО ТРИКОТАЖУ

The goal of the work is to determine the dependence of lightfastness of colours obtained by reactive dyes on the interlacing of cotton knitted fabrics. The study was carried out using cotton knitted fabrics of various interlacing: plain, rib knitted fabric 1×1 and pique. Samples of knitted fabric were previously prepared by the combined method of washing and peroxide bleaching. Dyeing was carried out by reactive dyes brand Bezaktiv Cosmos periodically. The insolation of the dyed samples was carried out on a device with a mercury-tungsten lamp. The lightfastness of the samples was evaluated according to BS 1006 UK/TN standard by determining color differences at regular intervals using a colorimeter.

Preparation of 2-arylquinolines from β-arylpropionitriles with aryllithiums and NIS through iminyl radical-mediated cyclization

Treatment of β-arylpropionitriles with aryllithiums, followed by the reaction with water and then with NIS under irradiation with a tungsten lamp gave 2-arylquinolines in good to moderate yields.

Research and Verification of Blackbody Radiation Law

<p>Blackbody radiation theory is one of the important origins of light quantum theory in the twentieth century. It is not only an important basis for quantum mechanics and photonics theory, but also an important conclusion of blackbody radiation, and an important foundation of modern measurement. In the early nineteenth century, the study of thermal radiation was supported by thermodynamics and spectroscopy, and the rapid development of electromagnetism and optics was used. By the end of the 19th century, it was recognized that both the thermal radiation and the optical radiation were electromagnetic waves, and began to study the distribution of radiant energy in different frequency ranges, especially the study of blackbody radiation in theory and practice. Blackbody radiation experiment is one of the contents of modern physics experiment in colleges and universities. This paper mainly studies and validates the law of blackbody radiation by the WGH-10 blackbody experimental device. There is already a calibrated bromine tungsten lamp energy curve at 2940k. At the beginning of the experiment, we should scan at 2940k color temperature to get the baseline, and then calculate the transfer function. Again, the energy curve obtained by scanning at different color temperatures is divided by the transfer function to obtain the correct energy radiation curve. The experimental study of blackbody radiation by computer scanning grating spectrometer and bromine tungsten lamp was carried out. By means of scrolling grating and sine mechanism, the data were recorded by computer scanning to verify the three laws of blackbody radiation directly, and the radiation, transmission and reception of blackbody were analyzed Error correction. </p>