Search results for "Near Infrared"
showing 10 items of 52 documents
Near-infrared photochemistry assisted by upconverting nanoparticles
2019
Abstract Upconverting nanoparticles (UCNPs) combine unique optical and imaging properties with high chemical and biological stability. The capability of UCNPs to emit visible light upon near-infrared light excitation, in an anti-Stokes fashion, is extremely attractive for the design of light-responsive nanomaterials whose action can be controlled spatially and temporally. In this chapter, we analyze the most promising approaches developed so far to functionalize the surface of UCNPs with photoactivatable organic and inorganic molecular systems. In particular, we emphasize the key advances in the design of upconverting nanosystems that exploit bioactive transition metal complexes.
Diagnostic Validity of Digital Imaging Fiber-Optic Transillumination (DIFOTI) and Near-Infrared Light Transillumination (NILT) for Caries in Dentine.
2020
The objective of the study is to analyse the available evidence for the validity of the transillumination method in the diagnosis of interproximal caries. Bibliographic searches were carried out in three data bases (PubMed, Embase, Scopus) with the key words “Transillumination AND caries”. A total of 11 studies were selected for the qualitative analysis and meta-analysis. In the qualitative analysis, both in vivo and in vitro studies were included. The gold standards were tomography, digital radiography, and clinical visual diagnosis. The meta-analysis determined the sensitivity, specificity, and area below the ROC curve relative to the transillumination method in the diagnosis …
Subcutaneous Veins Depth Estimation Method Using Monte Carlo Simulations
2015
International audience; Subcutaneous veins localization is basic and important step for any intravenous medication administration. Due to different physiological characteristics, mainly darker skin tone, scars or dehydrated condition of patients, medical staff face difficulty in veins localization. Through near infrared imaging technology the veins can be visualized due to high contrast between veins and skin tissue in this modality. Information on the depth of veins is equally important for proper catheterization or venipuncture procedures. Patients have different veins depth due to the different amount of fat present in the subcutaneous layer. The depth of veins from the skin surface cann…
Recognition and classification of external skin damage in citrus fruits using multispectral data and morphological features
2009
The computer vision systems currently used for the automatic inspection of citrus fruits are normally based on supervised methods that are capable of detecting defects on the surface of the fruit but are unable to discriminate between different types of defects. identifying the type of the defect affecting each fruit is very important in order to optimise the marketing profit and to be able to take measures to prevent such defects from occurring in the future. In this paper, we present a computer vision system that was developed for the recognition and classification of the most common external defects in citrus. in order to discriminate between 11 types of defects, images of the defects we…
Thermal inertia modeling for soil surface water content estimation: A laboratory experiment
2012
We are proposing a new method for estimating soil surface water content from thermal inertia distributions retrieved from visible–near infrared (VISNIR)and thermal infrared (TIR) images. A drying experiment was conducted on three fi ne-textured soils while acquiring multispectral VIS-NIR and TIR images. Simultaneous measurements of soil water content and thermal inertia were conducted by the thermogravimetric method and the heat pulse technique, respectively. Direct measurements were used to test the thermal inertia approach proposed by Murray and Verhoef that requires only knowledge of soil porosity and can be easily inverted to derive soil water content from thermal inertia. For the three…
Application of near Infrared Spectroscopy to the Quality Control of Citrus Fruits and Mango
2016
NIR spectroscopy is a proved tool to measure the optical properties of the samples, which are related to their chemical and textural properties. This technology can be used for determining the internal and external quality of fruits. Accordingly, many studies have been reported for long time to assess the quality of different fresh fruits by using reflectance measurements acquired with visible-NIR spectroscopy. We have been working on the estimation of the quality of fruits using computer vision for more than twenty years, always focused on problems that affect the local industry. As the region of Valencia (Spain) is one of the main producers and exporters of citrus fruits worldwide, most o…
Global modeling of the lower three polyads of PH_{3} Preliminary results
2009
International audience; In order to model the high-resolution infrared spectrum of the phosphine molecule in the 3 mu m region, a global approach involving the lower three polyads of the molecule (Dyad, Pentad and Octad) as been applied using an effective hamiltonian in the form of irreducible tensors. This model allowed to describe all the 15 vibrational states involved and to consider explicitly all relevant ro-vibrational interactions that cannot be accounted for by conventional perturbation approaches. 2245 levels (up to J=14) observed through transitions arising from 34 cold and hot bands including all available existing data as well as new experimental data have been fitted simultaneo…
Multispectral Photophletysmography for Evaluation of Cutaneous Flowmotions
2021
Human skin may reflect health conditions. Important and possibly diagnostically potent components of microcirculation are slow flow oscillations-flowmotions, however there is a lack of studies in this field. The present pilot study was devoted to evaluation of multispectral imaging photoplethysmography in determination of different components of flowmotions. Eight subjects were enrolled for the study. During resting conditions video was captured from dorsal aspect of hand at seven different wavelength and flowmotion analysis performed. Results indicate that at the resting conditions neurogenic component along with endothelial are dominant regardless of wavelength, while myogenic has the low…
Advances in solution-processed near-infrared light-emitting diodes
2021
A summary of recent advances in the near-infrared light-emitting diodes that are fabricated by solution-processed means, with coverage of devices based on organic semiconductors, halide perovskites and colloidal quantum dots.
Tunability of Injection Seeded High-Repetition Rate Ti:Sapphire Laser Far Off the Gain Peak
2009
We have investigated a tunability of a high‐repetition rate Ti:Sapphire laser seeded off the gain peak. By applying a birefringent filter, the 7 kHz injection seeded Ti:Sapphire laser system was operated with the average seeding efficiency of over 90% and the output power of over 1 W on the spectral range of 900–930 nm. We conclude that the birefringent filter suited for widely tunable operation of the injection seeded Ti:Sapphire laser system operated at high repetition rate.