scholarly journals On-Board Monitoring of SO2 Ship Emissions Using Resonant Photoacoustic Gas Detection in the UV Range

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4468
Author(s):  
Mahmoud El-Safoury ◽  
Miguel Dufner ◽  
Christian Weber ◽  
Katrin Schmitt ◽  
Hans-Fridtjof Pernau ◽  
...  
Keyword(s):  
Gas Flow ◽  
Limit Of Detection ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Photoacoustic Signal ◽  
Micro Electro Mechanical System ◽  
Exhaust Gas Emission ◽  
Mems Microphone ◽  
Gas Detector ◽  
Board Monitoring

A photoacoustic gas detector for SO2 was developed for ship exhaust gas emission monitoring. The basic measurement setup is based on the absorption of electromagnetic radiation of SO2 at 285 nm wavelength. A commercially available ultraviolet (UV) light-emitting diode (LED) is used as the light source and a micro-electro-mechanical system (MEMS) microphone as the detector. In order to achieve the required detection limits in marine applications, a measuring cell which allows an acoustically resonant amplification of the photoacoustic signal was developed and characterized. A limit of detection of 1 ppm was achieved in lab conditions during continuous gas flow. Long-term measurements on a container ship demonstrated the application relevance of the developed system.

scholarly journals Development of a Toluene Detector Based on Deep UV Absorption Spectrophotometry Using Glass and Aluminum Capillary Tube Gas Cells with a LED Source

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 193 ◽  
Author(s):  
Sulaiman Khan ◽  
David Newport ◽  
Stéphane Le Calvé
Keyword(s):  
Gas Flow ◽  
Capillary Tube ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Uv Absorption ◽  
Glass Capillary ◽  
Light Emitting ◽  
Uv Led ◽  
3D Printed ◽  
Deep Uv

A simple deep-ultraviolet (UV) absorption spectrophotometer based on ultraviolet light-emitting diode (UV LED) was developed for the detection of air-borne toluene with a good sensitivity. A fiber-coupled deep UV-LED was employed as a light source, and a spectrometer was used as a detector with a gas cell in between. 3D printed opto-fluidics connectors were designed to integrate the gas flow with UV light. Two types of hollow core waveguides (HCW) were tested as gas cells: a glass capillary tube with aluminum-coated inner walls and an aluminum capillary tube. The setup was tested for different toluene concentrations (10–100 ppm), and a linear relationship was observed with sensitivities of 0.20 mA·U/ppm and 0.32 mA·U/ppm for the glass and aluminum HCWs, respectively. The corresponding limits of detection were found to be 8.1 ppm and 12.4 ppm, respectively.

scholarly journals Ultrafine Aerosol Particle Sizer Based on Piezoresistive Microcantilever Resonators with Integrated Air-Flow Channel

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3731
Author(s):  
Maik Bertke ◽  
Ina Kirsch ◽  
Erik Uhde ◽  
Erwin Peiner
Keyword(s):  
Mass Concentration ◽  
Limit Of Detection ◽  
A Priori ◽  
Micro Electro Mechanical System ◽  
Single Chip ◽  
Air Stream ◽  
Mems Technology ◽  
Clean Air ◽  
Particle Sizer ◽  
Ultrafine Aerosol

To monitor airborne nano-sized particles (NPs), a single-chip differential mobility particle sizer (DMPS) based on resonant micro cantilevers in defined micro-fluidic channels (µFCs) is introduced. A size bin of the positive-charged fraction of particles herein is separated from the air stream by aligning their trajectories onto the cantilever under the action of a perpendicular electrostatic field of variable strength. We use previously described µFCs and piezoresistive micro cantilevers (PMCs) of 16 ng mass fabricated using micro electro mechanical system (MEMS) technology, which offer a limit of detection of captured particle mass of 0.26 pg and a minimum detectable particulate mass concentration in air of 0.75 µg/m3. Mobility sizing in 4 bins of a nebulized carbon aerosol NPs is demonstrated based on finite element modelling (FEM) combined with a-priori knowledge of particle charge state. Good agreement of better than 14% of mass concentration is observed in a chamber test for the novel MEMS-DMPS vs. a simultaneously operated standard fast mobility particle sizer (FMPS) as reference instrument. Refreshing of polluted cantilevers is feasible without de-mounting the sensor chip from its package by multiply purging them alternately in acetone steam and clean air.

FORCED INDICATING UPLC-DAD METHOD DEVELOPMENT AND VALIDATION FOR ESTIMATION OF APALUTAMIDE IN BULK AND IN PHARMACEUTICAL DOSAGE FORM

INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (09) ◽  
pp. 73-75
Author(s):  
China Babu D ◽  
Madhusudhana Chetty C ◽  
Mastanamma S. K ◽  
Keyword(s):  
Mobile Phase ◽  
Dosage Form ◽  
Method Development ◽  
Limit Of Detection ◽  
Uv Light ◽  
Accurate Method ◽  
Pharmaceutical Dosage Form ◽  
Good Ability ◽  
Acquity Uplc ◽  
Development And Validation

A new analytical method was developed for the estimation of apalutamide in bulk and its pharmaceutical formulation. The sensitive, précise and accurate method was developed by using Waters Acquity UPLC system equipped with quaternary gradient pump. The column used was Waters C18 150 X 2.1 mm X 1.7 µm and mobile phase was 0.2 % OPA buffer in water : acetonitrile in the ratio of 25:75 V/V. The buffer pH was maintained at 4.5. The fl ow rate of mobile phase was 0.5 mL min-1 and detection was at 272 nm by using PDA detector. The method was performed at ambient temperature. The retention time of the apalutamide was 1.27 min. The % RSD value in precision was >2 %. The accuracy of the method was found to be between 99.54 % - 100.01 %. The limit of detection and limit of quantifi cation values were found to be 0.14 µg mL-1 and 0.48 µg mL-1, respectively. The linearity concentration range was found to be 11.25 - 67.5 µg mL-1, it show wide linearity concentration range. The method was proved to have good robustness after changing parameters of fl ow rate, temperature and mobile phase composition. The method showed good ability towards different stress conditions of acidity, alkalinity, peroxide and UV-light. The method can be used for the routine analysis of apalutamide in bulk and its pharmaceutical dosage form by using UPLC.

Optical and structural properties of curcuminoids extracted from Curcuma longa L. for hybrid white light diode

2018 ◽  
Vol 84 (1) ◽  
pp. 10501 ◽  
Author(s):  
M. Al Shafouri ◽  
Naser M. Ahmed ◽  
Z. Hassan ◽  
Munirah Abdullah Almessiere ◽  
Maadh Jumaah
Keyword(s):  
White Light ◽  
Dye Degradation ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Stress Test ◽  
Air Gap ◽  
Color Temperature ◽  
Soxhlet Apparatus ◽  
Normal Method

In this study, curcuminoids were extracted from turmeric (Curcuma longa L.) by means of three methods, comprising the normal method, use of Soxhlet apparatus and by combining the normal method with the Soxhlet extraction approach. The limitation of stickiness in the use of curcuminoids was resolved by mixing it with silica gel. The curcuminoids used light down-conversion of UV light (390 nm) for the white light-emitting diode (WLED). The characteristics of the white light chromaticity were controlled by changing the current and concentration of the curcuminoids. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for different applied currents (20, 60 and 100 mA) and weights (25, 35 and 50 mg) of curcuminoids. It was observed from the concentration of phosphor that the combination of the normal and Soxhlet apparatus methods is most effective extraction approach. The results showed that increasing the concentration of phosphor significantly and remarkably increased the value of CCT when different values of current were applied. The stress test showed that the prolongation of dye degradation can be improved using air gap and glass slid, with air gap being more effective. An optimum color rendering index (CRI) value of 61.2 is obtained. The white phosphor exhibited CIE values of 0.333, 0.3151 and color temperature (CCT) of 5405 K.

scholarly journals LED and UV Light Utilizing Flavonoids and Limonoids to Investigate the Effect of Post-harvest Light Irradiation

2020 ◽  
Author(s):  
Shengyu Liu
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Red Light ◽  
Principal Component ◽  
Experimental Period ◽  
Light Irradiation ◽  
Flavonoid Glycosides ◽  
Clear Correlation ◽  
Post Harvest

To investigate the effect of post-harvest light irradiation on the accumulation of flavonoids and limonoids, harvestedNewhall navel oranges were continuously exposed to light-emitting diode (LED) and ultraviolet (UV) light irradiationfor 6 days, and the composition and content of flavonoids and limonoids in the segments were determined usingUPLC-qTOF-MS at 0, 6, and 15 days after harvest. In total, six polymethoxylated flavonoids (PMFs), fiveflavoneO/C-glycosides, seven flavanone-O-glycosides, and three limonoids were identified in the segments. Theaccumulation of these components was altered by light irradiation. Red and blue light resulted in higher levels ofPMFs during exposure periods. The accumulation of PMFs was also significantly induced after white light, UVBand UVC irradiation were removed. Red and UVC irradiation induced the accumulation of flavone and flavanoneglycosides throughout the entire experimental period. Single light induced limonoid accumulation during exposureperiods, but limonoid levels decreased significantly when irradiation was removed. Principal component analysisshowed a clear correlation between PMFs and white light, between flavonoid glycosides and red light and UVC,and between limonoids and UVC. These results suggest that the accumulation of flavonoids and limonoids in citrusis regulated by light irradiation. White light, red light and UVC irradiation might be a good potential method forimproving the nutrition and flavor quality of post-harvest citrus.

scholarly journals Suppression of “volcano” morphology and parasitic defect luminescence in AlGaN-based deep-UV light-emitting diode epitaxy

2019 ◽  
Vol 13 ◽  
pp. 102285 ◽  
Author(s):  
Chia-Yen Huang ◽  
Tsung-Yen Liu ◽  
Shih-Ming Huang ◽  
Kai-Hsiang Chang ◽  
Tsu-Ying Tai ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Deep Uv ◽  
Defect Luminescence

scholarly journals Chromaticity Study of Curcumin Dye Extracted from Curcuma longa L. Using for UV Light down Conversion for White Light Emitting Diode

2019 ◽  
Vol 290 ◽  
pp. 183-189
Author(s):  
Mahmood Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Major Factors ◽  
Color Rendering ◽  
Down Conversion

In thus study, Turmeric phosphor dye was extracted from Curcuma Longa L. via a simple technique using silica gel. The phosphor was used for light down-conversion of UV light for the manufacture white light emitting diode (WLED). The UV-LED was analyzed over 395nm wavelengths. The characteristics of the white light chromaticity were controlled by tuning the current and phosphor concentration. An optimum color rendering index (CRI) value of 63.4 was obtained. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for various currents and phosphor concentrations. The white phosphor exhibited CIE value of 0.355,0.338 and CCT of 4567 K. The concentration of phosphor and amount of applied current were confirmed to be major factors that control the intensity of white light emitted from the sample, where CIE and CRI of the emitted light steadily increased with the concentration of phosphor and current. Thus, phosphor concentration has a critical effect on conversion efficiency. Key words: Turmeric, phosphor, WLED, curcumin

scholarly journals Effect of Post-Harvest LED and UV Light Irradiation on the Accumulation of Flavonoids and Limonoids in the Segments of Newhall Navel Oranges (Citrus sinensis Osbeck)

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1755 ◽  
Author(s):  
Shengyu Liu ◽  
Linping Hu ◽  
Dong Jiang ◽  
Wanpeng Xi
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Red Light ◽  
Principal Component ◽  
Light Irradiation ◽  
Flavonoid Glycosides ◽  
Clear Correlation ◽  
Post Harvest ◽  
Uv Light Irradiation

To investigate the effect of post-harvest light irradiation on the accumulation of flavonoids and limonoids, harvested Newhall navel oranges were continuously exposed to light-emitting diode (LED) and ultraviolet (UV) light irradiation for 6 days, and the composition and content of flavonoids and limonoids in the segments were determined using UPLC-qTOF-MS at 0, 6, and 15 days after harvest. In total, six polymethoxylated flavonoids (PMFs), five flavone-O/C-glycosides, seven flavanone-O-glycosides, and three limonoids were identified in the segments. The accumulation of these components was altered by light irradiation. Red and blue light resulted in higher levels of PMFs during exposure periods. The accumulation of PMFs was also significantly induced after white light, UVB and UVC irradiation were removed. Red and UVC irradiation induced the accumulation of flavone and flavanone glycosides throughout the entire experimental period. Single light induced limonoid accumulation during exposure periods, but limonoid levels decreased significantly when irradiation was removed. Principal component analysis showed a clear correlation between PMFs and white light, between flavonoid glycosides and red light and UVC, and between limonoids and UVC. These results suggest that the accumulation of flavonoids and limonoids in citrus is regulated by light irradiation. White light, red light and UVC irradiation might be a good potential method for improving the nutrition and flavor quality of post-harvest citrus.

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