scholarly journals Determination of Vitamin C in Foods Using the Iodine-Turbidimetric Method Combined with an Infrared Camera

2020 ◽  
Vol 10 (8) ◽  
pp. 2655 ◽  
Author(s):  
Yi Miao ◽  
Yuanyang Zhu ◽  
Wenzhu Zhao ◽  
Changshuai Jiao ◽  
Hongwei Mo ◽  
...  
Keyword(s):  
Vitamin C ◽  
Light Emitting Diode ◽  
Infrared Camera ◽  
Infrared Light ◽  
Measuring Device ◽  
Light Emitting ◽  
Turbidimetric Method ◽  
Novel Method ◽  
Color Components

A novel method was proposed for the determination of vitamin C (VC) using an infrared camera combined with the iodine-turbidimetric method. Based on the redox between VC and iodine, the residual iodine was measured using the turbidimetric method with an infrared camera to obtain VC content. The light emitted by the infrared light-emitting diode (LED) was absorbed and scattered when it penetrated the residual iodine suspension. The transmitted light was captured by the infrared camera to form a digital image and the responding color components and grayscale values were obtained. The obtained color components and log-grayscale were fitted to the VC concentration, and the fitted relation expressions were used to measure the unknown VC solution. A VC measuring device equipped with an infrared camera and processing software was designed to obtain the color components corresponding to the images of the iodine suspensions. Compared with the spectrophotometry, the method based on the color component of brightness had a higher accuracy for measuring the VC standard solution. For VC measurements in tomatoes, nectarines, and VC tablets, our proposed method was highly consistent with spectrophotometry. Therefore, this method could potentially be implemented in the determination of VC in fruits and tablets, or other foods.

scholarly journals Earable POCER: Development of a Point-of-Care Ear Sensor for Respiratory Rate Measurement

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3020 ◽  
Author(s):  
Kazuhiro Taniguchi ◽  
Atsushi Nishikawa
Keyword(s):  
Respiratory Rate ◽  
Light Emitting Diode ◽  
Point Of Care ◽  
Respiratory Frequency ◽  
Infrared Light ◽  
Rate Measurement ◽  
Ear Canal ◽  
Measuring Device ◽  
Light Emitting ◽  
Reflected Light

We have carried out research and development on an earphone-type respiratory rate measuring device, earable POCER. The name earable POCER is a combination of “earable”, which is a word coined from “wearable” and “ear”, and “POCER”, which is an acronym for “point-of-care ear sensor for respiratory rate measurement”. The earable POCER calculates respiratory frequency, based on the measurement values over one minute, through the simple attachment of an ear sensor to one ear of the measured subject and displays these on a tablet terminal. The earable POCER irradiates infrared light using a light-emitting diode (LED) loaded on an ear sensor to the epidermis within the ear canal and, by receiving that reflected light with a phototransistor, it measures movement of the ear canal based on respiration. In an evaluation experiment, eight healthy subjects first breathed through the nose 12 times per minute, then 16 times per minute, and finally 20 times per minute, in accordance with the flashing of a timing instruction LED. The results of these evaluation tests showed that the accuracy of the respiratory frequency was 100% for nose breathing 12 times per minute, 93.8% at 16 times, and 93.8% at 20 times.

Heat-resistant reflectors for enhanced 850-nm near infrared light-emitting diode efficiency

2021 ◽  
pp. 103879
Author(s):  
Hyung-Joo Lee ◽  
Gwang-Hoon Park ◽  
Jin-Su So ◽  
Choong-Hun Lee ◽  
Jae-Hoon Kim ◽  
...  
Keyword(s):  
Near Infrared ◽  
Light Emitting Diode ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Light Emitting ◽  
Heat Resistant

Evaluation of Static Performance of Optoelectronic Semiconductor Devices under X-Rays Irradiation

2010 ◽  
Vol 173 ◽  
pp. 1-6 ◽  
Author(s):  
Haider F. Abdul Amir ◽  
Fuei Pien Chee
Keyword(s):  
Ionizing Radiation ◽  
Light Emitting Diode ◽  
Optoelectronic Devices ◽  
Third Party ◽  
Infrared Light ◽  
X Rays ◽  
Total Ionizing Dose ◽  
Light Emitting ◽  
Static Performance ◽  
Current Drives

In this research, optoelectronic devices consisted of an infrared light emitting diode and a phototransistor with no special handling or third party-packaging were irradiated to ionizing radiation utilizing x-rays. It was found that the devices under test (DUTs) undergo performance degradation in their functional parameters during exposure to x-rays. These damaging effects are depending on their current drives and also the Total Ionizing Dose (TID) absorbed. The TID effects by x-rays are cumulative and gradually take place throughout the lifecycle of the devices exposed to radiation.

scholarly journals Determination of 3,4,5-Trihydroxybenzoic Acid Exploiting a Visible-Light-Driven Photoelectrochemical Platform: Application in Wine and Tea Samples

2022 ◽  
Author(s):  
Kayni Lima ◽  
Ridvan Fernandes ◽  
Clenilton dos Santos ◽  
Flavio Damos ◽  
Rita de Cássia Luz
Keyword(s):  
Light Emitting Diode ◽  
Glass Slide ◽  
Experimental Conditions ◽  
Amperometric Determination ◽  
Light Emitting ◽  
Promising Tool ◽  
Visible Light Driven ◽  
Photoelectrochemical Method ◽  
Acid Determination

The present work is based on the development and application of a photoelectrochemical method for the amperometric determination of 3,4,5-trihydroxybenzoic acid in different samples. The method is based on the use of a photoelectrochemical platform based on a glass slide coated with fluorine-doped tin oxide, which has been modified with cadmium sulfide and poly(D-glucosamine) and subjected to a light-emitting diode (LED) lamp. The photoelectrochemical platform was sensitive to the increase of the concentration of the antioxidant 3,4,5-trihydroxybenzoic acid in the solution. Under the optimized experimental conditions, the photoelectrochemical method presented a linear response for a 3,4,5-trihydroxybenzoic acid concentration ranging from 0.2 up to 500 μmol L-1. The method was applied to 3,4,5-trihydroxybenzoic acid determination in samples of wines and teas with recoveries between 95.88 and 101.72%. The results obtained suggest that the developed platform is a promising tool for quantifying the 3,4,5-trihydroxybenzoic acid.

scholarly journals Determination of Dental Adhesive Composition throughout Solvent Drying and Polymerization Using ATR–FTIR Spectroscopy

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3886
Author(s):  
Arwa Almusa ◽  
António H.S. Delgado ◽  
Paul Ashley ◽  
Anne M. Young
Keyword(s):  
Light Exposure ◽  
Light Emitting Diode ◽  
Attenuated Total Reflectance ◽  
Drying Time ◽  
Light Emitting ◽  
Spectral Changes ◽  
One Step ◽  
Urethane Dimethacrylate ◽  
Kinetics Of

The of this study aim was to develop a rapid method to determine the chemical composition, solvent evaporation rates, and polymerization kinetics of dental adhesives. Single-component, acetone-containing adhesives One-Step (OS; Bisco, USA), Optibond Universal (OU; Kerr, USA), and G-Bond (GB; GC, Japan) were studied. Filler levels were determined gravimetrically. Monomers and solvents were quantified by comparing their pure Attenuated Total Reflectance-Fourier Transform Infra-Red (ATR–FTIR) spectra, summed in different ratios, with those of the adhesives. Spectral changes at 37 °C, throughout passive evaporation for 5 min, then polymerisation initiated by 20 s, and blue light emitting diode (LED) (600 mW/cm2) exposure (n = 3) were determined. Evaporation and polymerisation extent versus time and final changes were calculated using acetone (1360 cm−1) and methacrylate (1320 cm−1) peaks. OS, OU, and GB filler contents were 0, 9.6, and 5.3%. FTIR suggested OS and OU were Bis-GMA based, GB was urethane dimethacrylate (UDMA) based, and that each had a different diluent and acidic monomers and possible UDMA/acetone interactions. Furthermore, initial acetone percentages were all 40−50%. After 5 min drying, they were 0% for OS and OU but 10% for GB. Whilst OS had no water, that in OU declined from 18 to 10% and in GB from 25 to 20% upon drying. Evaporation extents were 50% of final levels at 23, 25, and 113 s for OS, OU, and GB, respectively. Polymerisation extents were all 50 and 80% of final levels before 10 and at 20 s of light exposure, respectively. Final monomer polymerisation levels were 68, 69, and 88% for OS, OU, and GB, respectively. An appreciation of initial and final adhesive chemistry is important for understanding the properties. The rates of evaporation and polymerisation provide indications of relative required drying and light cure times. UDMA/acetone interactions might explain the considerably greater drying time of GB.

Transcranial, Red/Near-Infrared Light-Emitting Diode Therapy to Improve Cognition in Chronic Traumatic Brain Injury

2016 ◽  
Vol 34 (12) ◽  
pp. 610-626 ◽  
Author(s):  
Margaret A. Naeser ◽  
Paula I. Martin ◽  
Michael D. Ho ◽  
Maxine H. Krengel ◽  
Yelena Bogdanova ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Near Infrared ◽  
Light Emitting Diode ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Light Emitting

On-site determination of the migration amount of fluorescent whitening agents from paper to finger by fluorescence spectrophotometry

2017 ◽  
Vol 9 (3) ◽  
pp. 465-472 ◽  
Author(s):  
Yang Yu ◽  
Xinghua Wang ◽  
Qiang Fei ◽  
Yong Yu ◽  
Sizhu Tian ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Fluorescence Spectrophotometry ◽  
Fluorescent Whitening Agents ◽  
Local Students

We have established a light emitting diode fluorescence spectrophotometer (LED-FS) for quantitatively determining the amount of FWA that migrates from paper notebooks or pads, used by local students, to fingers.

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