Determination of the size of dielectric particles using white light spectroscopy

2021 ◽  
Author(s):  
Kaloyan A. Popov
Keyword(s):  
White Light ◽  
Dielectric Particles

scholarly journals Fast and Sensitive Determination of the Fungicide Carbendazim in Fruit Juices with an Immunosensor Based on White Light Reflectance Spectroscopy

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 153
Author(s):  
Georgios Koukouvinos ◽  
Chrysoula-Evangelia Karachaliou ◽  
Ioannis Raptis ◽  
Panagiota Petrou ◽  
Evangelia Livaniou ◽  
...  
Keyword(s):  
White Light ◽  
Optical Biosensor ◽  
Reflectance Spectroscopy ◽  
Fruit Juices ◽  
Sample Treatment ◽  
Assay Sensitivity ◽  
Reliable Determination ◽  
Light Reflectance ◽  
Sensitive Determination

Carbendazim is a systemic benzimidazole-type fungicide with broad-spectrum activity against fungi that undermine food products safety and quality. Despite its effectiveness, carbendazim constitutes a major environmental pollutant, being hazardous to both humans and animals. Therefore, fast and reliable determination of carbendazim levels in water, soil, and food samples is of high importance for both food industry and public health. Herein, an optical biosensor based on white light reflectance spectroscopy (WLRS) for fast and sensitive determination of carbendazim in fruit juices is presented. The transducer is a Si/SiO2 chip functionalized with a benzimidazole conjugate, and determination is based on a competitive immunoassay format. Thus, for the assay, a mixture of an in-house developed rabbit polyclonal anti-carbendazim antibody with the standards or samples is pumped over the chip, followed by biotinylated secondary antibody and streptavidin. The WLRS platform allows for real-time monitoring of biomolecular interactions carried out onto the Si/SiO2 chip by transforming the shift in the reflected interference spectrum caused by the immunoreaction to effective biomolecular adlayer thickness. The sensor is able to detect 20 ng/mL of carbendazim in fruit juices with high accuracy and precision (intra- and inter-assay CVs ≤ 6.9% and ≤9.4%, respectively) in less than 30 min, applying a simple sample treatment that alleviates any “matrix-effect” on the assay results and a 60 min preincubation step for improving assay sensitivity. Excellent analytical characteristics and short analysis time along with its small size render the proposed WLRS immunosensor ideal for future on-the-spot determination of carbendazim in food and environmental samples.

Structure Determination of a New Molecular White-Light Source

2018 ◽  
Vol 255 (11) ◽  
pp. 1800083 ◽  
Author(s):  
Benjamin D. Klee ◽  
Eike Dornsiepen ◽  
Jens R. Stellhorn ◽  
Benedict Paulus ◽  
Shinya Hosokawa ◽  
...  
Keyword(s):  
Light Source ◽  
White Light ◽  
Structure Determination ◽  
White Light Source

Fast, sensitive and selective determination of herbicide glyphosate in water samples with a White Light Reflectance Spectroscopy immunosensor

Talanta ◽  
2020 ◽  
Vol 214 ◽  
pp. 120854 ◽  
Author(s):  
Eleftheria Stavra ◽  
Panagiota S. Petrou ◽  
Georgios Koukouvinos ◽  
Anastasios Economou ◽  
Dimitris Goustouridis ◽  
...  
Keyword(s):  
White Light ◽  
Water Samples ◽  
Reflectance Spectroscopy ◽  
Selective Determination ◽  
Light Reflectance ◽  
Herbicide Glyphosate

scholarly journals Estimating the mass of CMEs from the analysis of EUV dimmings

2019 ◽  
Vol 627 ◽  
pp. A8 ◽  
Author(s):  
F. M. López ◽  
H. Cremades ◽  
L. A. Balmaceda ◽  
F. A. Nuevo ◽  
A. M. Vásquez
Keyword(s):  
Relative Error ◽  
White Light ◽  
Line Of Sight ◽  
Absolute Relative Error ◽  
Empirical Function ◽  
Alternative Means ◽  
Extreme Uv ◽  
The Masses ◽  
Coronal Dimming

Context. Reliable estimates of the mass of coronal mass ejections (CMEs) are required to quantify their energy and predict how they affect space weather. When a CME propagates near the observer’s line of sight, these tasks involve considerable errors, which motivated us to develop alternative means for estimating the CME mass. Aims. We aim at further developing and testing a method that allows estimating the mass of CMEs that propagate approximately along the observer’s line of sight. Methods. We analyzed the temporal evolution of the mass of 32 white-light CMEs propagating across heliocentric heights of 2.5–15 R⊙, in combination with that of the mass evacuated from the associated low coronal dimming regions. The mass of the white-light CMEs was determined through existing methods, while the mass evacuated by each CME in the low corona was estimated using a recently developed technique that analyzes the dimming in extreme-UV (EUV) images. The combined white-light and EUV analyses allow the quantification of an empirical function that describes the evolution of CME mass with height. Results. The analysis of 32 events yielded reliable estimates of the masses of front-side CMEs. We quantified the success of the method by calculating the relative error with respect to the mass of CMEs determined from white-light STEREO data, where the CMEs propagate close to the plane of sky. The median for the relative error in absolute values is ≈30%; 75% of the events in our sample have an absolute relative error smaller than 51%. The sources of uncertainty include the lack of knowledge of piled-up material, subsequent additional mass supply from the dimming region, and limitations in the mass-loss estimation from EUV data. The proposed method does not rely on assumptions of CME size or distance to the observer’s plane of sky and is solely based on the determination of the mass that is evacuated in the low corona. It therefore represents a valuable tool for estimating the mass of Earth-directed events.

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