scholarly journals A multi-channel photometric detector for multi-component analysis in flow injection analysis

1994 ◽  
Vol 16 (2) ◽  
pp. 71-73 ◽  
Author(s):  
Aimin Tan ◽  
Jialin Huang ◽  
Liudi Geng ◽  
Jinhua Xu ◽  
Xinna Zhao
Keyword(s):  
Zinc Sulphate ◽  
Light Emitting Diode ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Light Emitting ◽  
Flow Cells ◽  
Photometric Detector ◽  
Sulphate Electrolyte ◽  
Multi Wavelength

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors.

Anti-Glare Device for Car Based on Single Chip Microcomputer

2013 ◽  
Vol 706-708 ◽  
pp. 1124-1127
Author(s):  
Hai Xia Li
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Lamp Method ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Light Emitting ◽  
High Beam ◽  
The Core

Because the car headlamp light intensity is too large and it leads to accidents, This paper is based on the initiative to reduce the light intensity of their vehicles according headlights glare or close the high beam and open the lamp method, to achieve the purpose of the glare. The system is AT89C51 microcontroller as the core control, use of photodiode sensor to induction opposite the car headlights light intensity , when opposite car headlights light intensity up to a certain value, photodiode get a signal to the microcontroller ,and then microcontroller sends a signal, to control buzzer sound or not. When the buzzer sounded, using DAC0832 chip to control the brightness of the light emitting diode or control the light on and off and low beam enabled. When enabled for dipped beam, has been more than the antiglare range; after the scope enabled high beam, in order to achieve the anti-dazzle cycle. Through practice, the system has reached the anti-dazzle purpose and has practical value .

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.

scholarly journals A 3 W High-Voltage Single-Chip Green Light-Emitting Diode with Multiple-Cells Network

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
W. Wang ◽  
Y. Cai ◽  
Y. B. Zhang ◽  
H. J. Huang ◽  
W. Huang ◽  
...  
Keyword(s):  
High Voltage ◽  
Light Emitting Diode ◽  
Light Output ◽  
Green Light ◽  
Current Crowding ◽  
Single Chip ◽  
Light Output Power ◽  
Large Area ◽  
Light Emitting ◽  
Multiple Cells

A parallel and series network structure was introduced into the design of the high-voltage single-chip (HV-SC) light-emitting diode to inhibit the effect of current crowding and to improve the yield. Using such a design, a6.6×5 mm2large area LED chip of 24 parallel stages was demonstrated with 3 W light output power (LOP) at the current of 500 mA. The forward voltage was measured to be 83 V with the same current injection, corresponding to 3.5 V for a single stage. The LED chip’s average thermal resistance was identified to be 0.28 K/W by using infrared thermography analysis.

Characteristics of Single-Chip GaN-Based Alternating Current Light-Emitting Diode

2008 ◽  
Vol 47 (12) ◽  
pp. 8808-8810 ◽  
Author(s):  
Hsi-Hsuan Yen ◽  
Hao-Chung Kuo ◽  
Wen-Yung Yeh
Keyword(s):  
Light Emitting Diode ◽  
Alternating Current ◽  
Single Chip ◽  
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.

Miniaturized UV-LED Array Chip Photochemical Vapor Generator Coupled with Point Discharge Optical Emission Spectrometer for Determination of Trace Selenium

2021 ◽  
Author(s):  
Mengtian Li ◽  
Yi Luo ◽  
Zhirong Zou ◽  
Fujian Xu ◽  
Xiaoming Jiang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Optical Emission ◽  
Nano Tio2 ◽  
Light Emitting ◽  
Uv Led ◽  
Led Array ◽  
Point Discharge ◽  
Photochemical Vapor Generation ◽  
Optical Emission Spectrometer

An ultraviolet light emitting diode (UV-LED) array chip as irradiation source for nano-TiO2 catalyzed photochemical vapor generation (PCVG) was combined with a hollow electrode point discharge microplasma optical emission spectrometer...

scholarly journals Portable Instrument for Hemoglobin Determination Using Room-Temperature Phosphorescent Carbon Dots

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 825
Author(s):  
Fabio Murru ◽  
Francisco J. Romero ◽  
Roberto Sánchez-Mudarra ◽  
Francisco J. García Ruiz ◽  
Diego P. Morales ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Room Temperature ◽  
Light Emitting Diode ◽  
Electronic System ◽  
Portable Device ◽  
Light Emitting ◽  
Current Converter ◽  
Reconfigurable Platform ◽  
Luminescence Characteristics

A portable reconfigurable platform for hemoglobin determination based on inner filter quenching of room-temperature phosphorescent carbon dots (CDs) in the presence of H2O2 is described. The electronic setup consists of a light-emitting diode (LED) as the carbon dot optical exciter and a photodiode as a light-to-current converter integrated in the same instrument. The reconfigurable feature provides adaptability to use the platform as an analytical probe for CDs coming from different batches with some variations in luminescence characteristics. The variables of the reaction were optimized, such as pH, concentration of reagents, and response time; as well as the variables of the portable device, such as LED voltage, photodiode sensitivity, and adjustment of the measuring range by a reconfigurable electronic system. The portable device allowed the determination of hemoglobin with good sensitivity, with a detection limit of 6.2 nM and range up to 125 nM.

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