scholarly journals Laser assisted synthesis of anisotropic metal nanocrystals and strong light-matter coupling in decahedral bimetallic nanocrystals

2021 ◽  
Author(s):  
Fadime Mert Balci ◽  
Sema Sarisozen ◽  
Nahit Polat ◽  
C. Meric Guvenc ◽  
Ugur Karadeniz ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Region ◽  
Electromagnetic Spectrum ◽  
Colloid Chemistry ◽  
Strong Light ◽  
Metal Nanocrystals ◽  
Matter Coupling ◽  
Bimetallic Nanocrystals ◽  
Tunable Optical Properties ◽  
Anisotropic Metal

The advances in colloid chemistry and nanofabrication allowed us to synthesize noble monometallic and bimetallic nanocrystals with tunable optical properties in the visible and near infrared region of the electromagnetic spectrum.

scholarly journals Hyperspectral and Multispectral Image Fusion Techniques

2020 ◽  
Vol 8 (5) ◽  
pp. 467-471
Keyword(s):  
Image Fusion ◽  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Spatial Information ◽  
Hyperspectral Image ◽  
Qualitative Comparative Analysis ◽  
Infrared Region ◽  
Multispectral Image ◽  
Electromagnetic Spectrum ◽  
Fusion Methods

The hyper spectral image covers a broad range of wavelengths in electromagnetic spectrum, spanning from visible to near-infrared region. The basic objective of hyperspectral imaging is to attain the spectrum for each pixel in the image of a scene, with the aim of identifying objects in the scene and its classification. The hyperspectral images give detailed spectral information but their spatial resolution is very poor. So to enhance the visual quality of the hyperspectral image, we can perform image fusion with high spatial information multispectral image. This paper provides a complete description of hyperspectral imaging and image fusion methods of hyperspectral and multispectral images. A quantitative and qualitative comparative analysis on performance of various hyperspectral and multispectral image fusion techniques are also done.

scholarly journals Spectroscopic near-infrared photodetectors enabled by strong light–matter coupling in (6,5) single-walled carbon nanotubes

2020 ◽  
Vol 153 (20) ◽  
pp. 201104
Author(s):  
Andreas Mischok ◽  
Jan Lüttgens ◽  
Felix Berger ◽  
Sabina Hillebrandt ◽  
Francisco Tenopala-Carmona ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Near Infrared ◽  
Single Walled Carbon Nanotubes ◽  
Infrared Photodetectors ◽  
Strong Light ◽  
Single Walled Carbon ◽  
Matter Coupling ◽  
Walled Carbon Nanotubes

scholarly journals Spectral Response of Eucalyptus saligna under Water Stress in Southern Brazil

2019 ◽  
pp. 1-8
Author(s):  
Lorena de Moura Melo ◽  
Adriano Castelo Dos Santos ◽  
Kardelan Arteiro da Silva ◽  
Uilian do Nascimento Barbosa ◽  
Géssyca Fernanda De Sena Oliveira ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Near Infrared ◽  
Spectral Response ◽  
Infrared Region ◽  
Electromagnetic Spectrum ◽  
Eucalyptus Saligna ◽  
Green Vegetation ◽  
Santa Maria ◽  
Genus Eucalyptus

The present work aims to assess the effect of water stress on the reflectance emitted by leaves of Eucalyptus saligna individuals. The design was completely randomized and the study comprised 30 subjects who underwent 5 cycles of drought simulation, 45 days each. Five individuals were submitted to water deficit treatment and five were used as controls, remaining in adequate water conditions. The experiment and data collection were performed in the external facilities of the forest management laboratory of the Federal University of Santa Maria, Rio Grande do Sul, Brazil. Which it comprised the period from September 2014 to April 2015. Spectral information was collected from 24-month-old tree individuals in adequate water and water stress situations by means of FieldSpec®3 spectroradiometer. Subsequently, the spectral data for the electromagnetic spectrum range from 400 nm to 1700 nm were processed and analyzed. The resulting spectral behavior varied between water stress cycles. In the 450 nm wavelength range, the reflectances ranged from 3.8% to 7.4%, at 550 nm from 7.9% to 14% and at 650 nm from 4.8% to 8.8%. In the near infrared region, in the 900 nm to 1300 nm range, the reflectances ranged from 28% to 62%. The spectral response of E. saligna showed minimal differences when compared to healthy green vegetation, even though it was exposed to water deficit situations. From the information obtained, this research can be used as a parameter for comparative analysis between species belonging to the genus Eucalyptus sp.

scholarly journals AVIRIS-NG Data for Geological Applications in Southeastern Parts of Aravalli Fold Belt, Rajasthan

Proceedings ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 16
Author(s):  
Sameeksha Mishra ◽  
Shovan L. Chattoraj ◽  
Alen Benny ◽  
Richa U. Sharma ◽  
P. K. Champati Ray
Keyword(s):  
High Resolution ◽  
Near Infrared ◽  
Country Rock ◽  
Satellite Image ◽  
Infrared Region ◽  
Hyperspectral Data ◽  
Electromagnetic Spectrum ◽  
Fold Belt ◽  
Spectral Angle Mapper ◽  
Iron Bearing

Advanced techniques using high resolution hyperspectral remote sensing data has recently evolved as an emerging tool with potential to aid mineral exploration. In this study, pertinently, five mosaicked scenes of Airborne Visible InfraRed Imaging Spectrometer-Next Generation (AVIRIS-NG) hyperspectral data of southeastern parts of the Aravalli Fold belt in Jahazpur area, Rajasthan, were processed. The exposed Proterozoic rocks in this area is of immense economic and scientific interest because of richness of poly-metallic mineral resources and their unique metallogenesis. Analysis of high resolution multispectral satellite image reveals that there are many prominent lineaments which acted as potential conduits of hydrothermal fluid emanation, some of which resulted in altering the country rock. This study takes cues from studying those altered minerals to enrich our knowledge base on mineralized zones. In this imaging spectroscopic study we have identified different hydrothermally altered minerals consisting of hydroxyl, carbonate and iron-bearing species. Spectral signatures (image based) of minerals such as Kaosmec, Talc, Kaolinite, Dolomite, and Montmorillonite were derived in SWIR (Short wave infrared) region while Iron bearing minerals such as Goethite and Limonite were identified in the VNIR (Visible and Near Infrared) region of electromagnetic spectrum. Validation of the target minerals was done by subsequent ground truthing and X-ray diffractogram (XRD) analysis. The altered end members were further mapped by Spectral Angle Mapper (SAM) and Adaptive Coherence Estimator (ACE) techniques to detect target minerals. Accuracy assessment was reported to be 86.82% and 77.75% for SAM and ACE respectively. This study confirms that the AVIRIS-NG hyperspectral data provides better solution for identification of endmember minerals.

scholarly journals Application of the Non-Destructive NIR Technique for the Evaluation of Strawberry Fruits Quality Parameters

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 441 ◽  
Author(s):  
Manuela Mancini ◽  
Luca Mazzoni ◽  
Francesco Gagliardi ◽  
Francesca Balducci ◽  
Daniele Duca ◽  
...  
Keyword(s):  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Infrared Region ◽  
Quality Parameters ◽  
Soluble Solids ◽  
Electromagnetic Spectrum ◽  
Least Squares Regression ◽  
Solids Content ◽  
Non Destructive

The determination of strawberry fruit quality through the traditional destructive lab techniques has some limitations related to the amplitude of the samples, the timing and the applicability along all phases of the supply chain. The aim of this study was to determine the main qualitative characteristics through traditional lab destructive techniques and Near Infrared Spectroscopy (NIR) in fruits of five strawberry genotypes. Principal Component Analysis (PCA) was applied to search for spectral differences among all the collected samples. A Partial Least Squares regression (PLS) technique was computed in order to predict the quality parameters of interest. The PLS model for the soluble solids content prediction was the best performing—in fact, it is a robust and reliable model and the validation values suggested possibilities for its use in quality applications. A suitable PLS model is also obtained for the firmness prediction—the validation values tend to worsen slightly but can still be accepted in screening applications. NIR spectroscopy represents an important alternative to destructive techniques, using the infrared region of the electromagnetic spectrum to investigate in a non-destructive way the chemical–physical properties of the samples, finding remarkable applications in the agro-food market.

scholarly journals Recent Developments in Instrumentation of Functional Near-Infrared Spectroscopy Systems

2020 ◽  
Vol 10 (18) ◽  
pp. 6522
Author(s):  
Murad Althobaiti ◽  
Ibraheem Al-Naib
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Continuous Wave ◽  
Infrared Region ◽  
Point Of View ◽  
Electromagnetic Spectrum ◽  
Functional Near Infrared Spectroscopy ◽  
Recent Developments ◽  
In The Beginning

In the last three decades, the development and steady improvement of various optical technologies at the near-infrared region of the electromagnetic spectrum has inspired a large number of scientists around the world to design and develop functional near-infrared spectroscopy (fNIRS) systems for various medical applications. This has been driven further by the availability of new sources and detectors that support very compact and wearable system designs. In this article, we review fNIRS systems from the instrumentation point of view, discussing the associated challenges and state-of-the-art approaches. In the beginning, the fundamentals of fNIRS systems as well as light-tissue interaction at NIR are briefly introduced. After that, we present the basics of NIR systems instrumentation. Next, the recent development of continuous-wave, frequency-domain, and time-domain fNIRS systems are discussed. Finally, we provide a summary of these three modalities and an outlook into the future of fNIRS technology.

scholarly journals Improvements in Gold Nanorod Biocompatibility with Sodium Dodecyl Sulfate Stabilization

2021 ◽  
Author(s):  
Rossana Terracciano ◽  
Aobo Zhang ◽  
Mathieu L. Simeral ◽  
Danilo Demarchi ◽  
Jason H. Hafner ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Cell Lines ◽  
Near Infrared ◽  
Sodium Dodecyl ◽  
Living Organism ◽  
Infrared Region ◽  
Aqueous Environment ◽  
Electromagnetic Spectrum ◽  
Dependent Effect ◽  
Dodecyl Sulfate

Due to their well-defined plasmonic properties, gold nanorods (GNRs) can be fabricated with optimal light absorption in the near-infrared region of the electromagnetic spectrum, which make them suitable for cancer-related theranostic applications. However, their controversial safety profile, as a result of surfactant stabilization during synthesis, limits their clinical translation. We report a facile method to improve GNR biocompatibility through the presence of sodium dodecyl sulfate (SDS). GNRs (120 x 40 nm) were synthesized through a seed-mediated approach, using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant to direct the growth of nanorods and stabilize the particles. Post-synthesis, SDS was used as an exchange ligand to modify the net surface charge of the particles from positive to negative while maintaining rod stability in an aqueous environment. GNR cytotoxic effects, as well as the mechanisms of their cellular uptake, were examined in two different cancer cell lines, Lewis lung carcinoma (LLC) and HeLa cells. We not only found a significant dose-dependent effect of GNR treatment on cell viability but also a time-dependent effect of GNR surfactant charge on cytotoxicity over the two cell lines. Our results promote a better understanding of how we can mediate the undesired consequences of GNR synthesis byproducts when exposed to a living organism, which so far has limited GNR use in cancer theranostics.

scholarly journals Mapping Surface Quartz Content in Sand Dunes Covered by Biological Soil Crusts Using Airborne Hyperspectral Images in the Longwave Infrared Region

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 318 ◽  
Author(s):  
Shahar Weksler ◽  
Offer Rozenstein ◽  
Eyal Ben-Dor
Keyword(s):  
Near Infrared ◽  
Sand Dunes ◽  
Ground Truth ◽  
Infrared Region ◽  
Biological Soil Crusts ◽  
Hyperspectral Images ◽  
Electromagnetic Spectrum ◽  
Quartz Content ◽  
Soil Crusts ◽  
Field Samples

Biological soil crusts (BSCs), composed of cyanobacteria, algae, mosses, lichens, and fungi, are important ecosystem engineers that stabilize the quartz-rich dunes in the Nitzana study area near the Israel–Egypt border. The longwave infrared (LWIR) region of the electromagnetic spectrum is very useful for quartz identification since quartz reflectance in the visible, near infrared, and shortwave infrared (VIS-NIR-SWIR, 0.4–2.5 µm) spectral regions lacks identifying features, whereas in the LWIR region, the quartz emissivity spectrum presents a strong doublet feature. This emissivity feature can be used as a diagnostic tool for BSCs development in desert environments, because BSCs attenuate the quartz feature as a function of their successional development. A pair of day and night airborne hyperspectral images were acquired using the Specim AisaOWL LWIR sensor (7.7–12 µm) and processed using an innovative algorithm to reduce the atmospheric interference in this spectral domain. The resulting day and night apparent emissivity products were used to produce a surface quartz content map of the study area. The significant reduction in atmospheric interference resulted in a high correlation (R2 = 0.88) between quartz content in field samples determined by X-ray powder diffraction analysis and emissivity estimations from the airborne images. This, in turn, served as the ground truth to our quartz content map of the surface, and by proxy to the BSC.

scholarly journals Improvements in Gold Nanorod Biocompatibility with Sodium Dodecyl Sulfate Stabilization

2021 ◽  
Vol 2 (3) ◽  
pp. 157-173
Author(s):  
Rossana Terracciano ◽  
Aobo Zhang ◽  
Mathieu L. Simeral ◽  
Danilo Demarchi ◽  
Jason H. Hafner ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Cell Lines ◽  
Near Infrared ◽  
Sodium Dodecyl ◽  
Living Organism ◽  
Infrared Region ◽  
Aqueous Environment ◽  
Electromagnetic Spectrum ◽  
Dependent Effect ◽  
Dodecyl Sulfate

Due to their well-defined plasmonic properties, gold nanorods (GNRs) can be fabricated with optimal light absorption in the near-infrared region of the electromagnetic spectrum, which make them suitable for cancer-related theranostic applications. However, their controversial safety profile, as a result of surfactant stabilization during synthesis, limits their clinical translation. We report a facile method to improve GNR biocompatibility through the presence of sodium dodecyl sulfate (SDS). GNRs (120 × 40 nm) were synthesized through a seed-mediated approach, using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant to direct the growth of nanorods and stabilize the particles. Post-synthesis, SDS was used as an exchange ligand to modify the net surface charge of the particles from positive to negative while maintaining rod stability in an aqueous environment. GNR cytotoxic effects, as well as the mechanisms of their cellular uptake, were examined in two different cancer cell lines, Lewis lung carcinoma (LLC) and HeLa cells. We not only found a significant dose-dependent effect of GNR treatment on cell viability but also a time-dependent effect of GNR surfactant charge on cytotoxicity over the two cell lines. Our results promote a better understanding of how we can mediate the undesired consequences of GNR synthesis byproducts when exposed to a living organism, which so far has limited GNR use in cancer theranostics.

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