Near-infrared Region Of Spectrum Research Articles

Thio-naphthalene-modified artificial bases as targeted photosensitizers for two-photon photodynamic therapy

In this work, a series of quasi-intrinsic photosensitizers (PSs) are designed based on 2-amino-8-(1′-β-d-2′-deoxyribofuranosyl)-imidazo[1,2-a]-1,3,5-triazin-4(8H)-one (P), which could pair with the 6-amino-5-nitro-3-(1-β-d-2′-deoxyribofuranosyl)-2(1H)-pyridone (Z) and specifically recognize breast and liver cancer cells. The spectra calculations show that the modified bases possess efficient two-photon absorption in red and near-infrared spectra region that contribute to an efficient photodynamic therapy (PDT) for deep-seated tumors. After the vertical excitation, these modified bases in the excited singlet state exhibit a predominance of intersystem crossing to the triplet state channels, which can be predicted by the energy difference and the spin-orbit coupling values between the singlet and triplet states. Additionally, the triplet state lifetimes are examined by considering the radiative and non-radiative rates, thus reflecting the interaction time of the PS with molecular oxygen. To evaluate the direct usefulness in PDT, we further investigated the effect of base pairing and linking to deoxyribose on photosensitivity.

Highly Responsive Switchable Broadband DUV-NIR Photodetector and Tunable Emitter Enabled by Uniform and Vertically Grown III-V Nanowire on Silicon Substrate for Integrated Photonics.

Low-dimensional semiconductor nanostructures, particularly in the form of nanowire configurations with large surface-to-volume-ratio, offer intriguing optoelectronic properties for the advancement of integrated photonic technologies. Here, a bias-controlled, superior dual-functional broadband light detecting/emitting diode enabled by constructing the aluminum-gallium-nitride-based nanowire on the silicon-platform is reported. Strikingly, the diode exhibits a stable and high responsivity (R) of over 200mAW-1 covering an extremely wide operation band under reverse bias conditions, ranging from deep ultraviolet (DUV: 254nm) to near-infrared (NIR: 1000nm) spectrum region. While at zero bias, it still possesses superior DUV light selectivity with a high off-rejection ratio of 106. When it comes to the operation of the light-emitting mode under forward bias, it can achieve large spectral changes from UV to red simply by coating colloid quantum dots on the nanowires. Based on the multifunctional features of the diodes, this study further employs them in various optoelectronic systems, demonstrating outstanding applications in multicolor imaging, filterless color discrimination, and DUV/NIR visualization. Such highly responsive broadband photodetector with a tunable emitter enabled by III-V nanowire on silicon provides a new avenue toward the realization of integrated photonics and holds great promise for future applications in communication, sensing, imaging, and visualization.

Organic–inorganic hybrid nanoflowers as a new biomimetic platform for ROS-induced apoptosis by photodynamic therapy

We report here a newly and facile synthesis of the phospholipids@gold nanoflowers (AuNFs) from intact cells as a new biomimetic organic-inorganic hybrid. The most appealing feature of this nanostructure is its dual-absorbing peak in near infrared (NIR) and visible region of spectra, which makes them a potential light-sensitive agent for reactive oxygen species (ROS)-induced apoptosis. Here, in contrast to previous studies, proposed nanostructures are synthesized in a one-pot reaction using phospholipids present in living cell membranes (as a donor cell) with detectable micro process of AuNF formation. The properties of the resulting AuNFs were evaluated through transmission electron microscopy (TEM), as well as FT-IR, 31P-NMR spectra and UV–Vis spectroscopy. Designed cell membrane-based nanostructure looks like an intact cell and would be able to interact with other cells (as a target cell) and also capable to produce cytotoxic singlet oxygen under NIR irradiation. Generated ROS act as a key player in initiation of programmed cell death (apoptosis) and progress of cancer photodynamic therapy (PDT). Cellular experiments on breast cancer MCF-7 cells demonstrated that they may be effective as photodynamic therapy agents.

Broadband third-order nonlinear optical response of indium tin oxide in the near infrared spectrum

We reported the broadband optical nonlinearity of indium tin oxide (ITO) films with different thickness in the near-infrared spectrum region. The maximum nonlinear response is obtained at its epsilon-near-zero (ENZ) wavelength, and the measured maximum nonlinear refractive index n2 and nonlinear absorption coefficient β at the ENZ wavelength are 47 times and 28 times larger than the corresponding values at the 1000 nm wavelength, respectively. Meanwhile, a large modulation depth of 9.8% hinted that the ITO has good nonlinear modulation characteristics. In addition, the numerical simulation analysis illustrates the large nonlinear enhancement effect of ITO films, which is attributed to the significant enhancement of electric field due to the ENZ conditions. Our results highlight that ITO is a competitive nonlinear material and has great potential applications in the field of nonlinear optics and all-optical modulators.

Phosphorescence of hexachlorosubstituted subphthalocyanine and its pyrazine analogue

Spectral luminescence, kinetic and energetic properties of hexachlorosubphthalocyaninatoboron(III) chloride and its azaanalogue containing fused pyrazine fragments instead of benzene rings were studied at 298 and 77 K. Weak phosphorescence of complexes was detected and characterized in near-infrared region of spectrum, its parameters depend substantially on the presence of methyl iodide due to its external effect of heavy atom in solutions. Quantum yields of photosensitized formation of singlet oxygen were determined by the relative luminescence method.

The blue wavelengths in laser dentistry: a review of current literature

Dental laser applications are steadily increasing in popularity amongst dentists for the last four decades. Although many wavelengths are available for practitioners, semiconductor lasers or commonly known as diode lasers, are still the most popular ones. Dental diode laser devices are available in wavelengths that belong to visible and near infrared region of the electromanetic spectrum. Recently, lasers that are in the area of 400–450 nm have emerged in the market and became available to dentists. In this article, we aim to analyze the clinical possibilities we have with these lasers according to the available literature that has been published so far.

Assessment of Dau Tieng reservoir water quality using standard criteria combined with remotely sensed images

Water quality (WQ) pollution is a matter of concern to everyone, and it is necessary to take remedial measures to protect human life. This paper presents the assessment of surface WQ through the Water Quality Index (WQI) followed by the Vietnam Standard QCVN 08-MT:2015/BTNMT combined with satellite data for the Dau Tieng reservoir. The implementation method is based on the correlation of each WQ indicator with the spectral features of satellite images to build a regression function, simulating the spatial distribution of the entire reservoir. The Sentinel-2A satellite images were used with reflective bands in the visible and near-infrared (NIR) spectrum region. The regression functions showed that the correlation of the WQ indicators was related to single bands, and the band ratios include blue and NIR, red/blue, green/blue, and NIR/blue bands. Simulation results of the WQI spatial distribution expressed that the WQ of the Dau Tieng reservoir was in a polluted state at the level of WQI fluctuation in the range of 0–50 for the most part. Dau Tieng irrigation system plays a vital role in the water distribution system for Tay Ninh province and the southern key economic region. Therefore, appropriate treatment measures should be taken if it needs to be used for domestic water supply purposes.

Detecting nutrient deficiencies in Eucalyptus grandis trees using hyperspectral remote sensing and random forest

Nutrient deficiencies in commercial forest trees often lead to stunted growth and reduced chances of field survival, resulting in a loss of time, productivity, and trees that can become more susceptible to a host of infections. While conventional foliar analytical methods provide accurate results, they are not time and cost-effective in a high productivity environment. This study aims to test the capability of remote sensing to detect macronutrient and micronutrient deficiencies rapidly in juvenile trees. We acquired full-waveform hyperspectral data (350nm-2500nm) from 135 young trees planted in individual pots in a controlled forestry nursery environment. We quantified nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and boron (B) in young commercially planted forest variety. This study identified the most critical wavebands for detecting nutrient deficiencies using built-in random forest (RF) measures of variable importance. The random forest algorithm's robustness significantly reduced the dataset's noise whilst producing promising results for certain macronutrients such as P and N (0.95 and 0.89, respectively) and micronutrients such as Mn and Cu (0.90 and 0.86, respectively). We identified the red-edge, near-infrared (NIR), visible and short-wave infrared-2 (SWIR-2) regions of the electromagnetic spectrum as the most effective regions for detecting macronutrients and micronutrients in this study. We recommend testing the use of strategic portions of the electromagnetic spectrum for reducing noise and enabling faster computing time, such as portable near-infrared technology.

Optical Properties of Copper Monosulphide Nanoparticles in Near-Infrared Spectrum Region

Optical Properties of Copper Monosulphide Nanoparticles in Near-Infrared Spectrum Region

Theoretical Study on Polycarbonate-Based One-Dimensional Ternary Photonic Structures from Far-Ultraviolet to Near-Infrared Regions of Electromagnetic Spectrum

In the present research work, we have theoretically analyzed the photonic band-gap properties of one-dimensional photonic structures composed of polycarbonate and non-glass materials. These photonic structures, PC1, PC2, PC3 and PC4, are composed of alternating layers of polycarbonate/Al2O3, polycarbonate/MgF2, polycarbonate/BaF2 and polycarbonate/TiO2 materials, respectively. The period of each photonic structure is made up of a thin non-glass material layer sandwiched between two identical polycarbonate layers. The transfer matrix method has been used to investigate the transmission properties of PC1 to PC4. The comparison between the transmission spectra of PC1 to PC4 shows that the polycarbonate and TiO2-based photonic structure (PC4) possess three PBGs of zero transmission located at far-ultraviolet, visible and near-infrared regions of the electromagnetic spectrum at normal and oblique incidence (θ0 = 55°), both corresponding to TE wave only. The index of refraction of all five materials used in this study was obtained by applying the Sellmeier-type dispersion relationship to ensure accuracy in the results. The purpose of selecting polycarbonate along with Al2O3, TiO2, MgF2 or BaF2 as constituent materials of these photonic structures is due to the heat resistance properties of polycarbonate and the unique optical properties of oxide and fluoride materials with wide transparency from the ultraviolet to the near-infrared regions of the electromagnetic spectrum. The proposed work can be used to design some influential wavelength-selective reflectors composed of 1D PCs behind the active region of the solar cells for improving the photovoltaic performance of solar panels. This study can further be utilized for the fabrication of advanced solar cell designs consisting of 1D photonic mirror-based luminescence and reflection concentrators. The low temperature problem which arises in satellites may also be overcome with the help of smart windows based on the proposed multilayer structures.

Study of the Impact of Transcatheter Intracerebral Laser Photobiomodulation Therapy Treatment on Patients with Alzheimer's Disease and Binswanger's Disease

Background: Alzheimer's disease (AD) and Binswanger's disease (BD) are among the most common neurodegenerative disorders associated with cognitive impairment and dementia. Using energy of lasers with low output power of the red or near-infrared spectrum region called Photobiomodulation Therapy (PBMT), is an achievement in the development of methods for the treatment of these diseases. Aims: The present study investigates the impact of Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) on the reduction of cognitive, mental impairment and dementia in patients with various Alzheimer's Disease and Binswanger's Disease stages. Methods: For the research, we selected 62 patients suffering from dementia, aged 34-81 (mean age 72.75), 25 men (40.32%), 37 women (59.68%). Test Group 1 - 48 patients previously diagnosed with Alzheimer's Disease. According to dementia severity, patients were subdivided: preclinical stage (dementia level TDR-0) - 4, mild stage (dementia level TDR-1) - 16, moderately severe stage (dementia level TDR-2) - 21, severe stage (dementia level TDR-3) - 7. Test Group 2 - 14 patients with previously diagnosed Binswanger's Disease. According to dementia severity, the patients were subdivided: mild stage (dementia level CDR-1) - 9, moderately severe stage (dementia level CDR-2) - 5. All patients underwent Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT). Results: Test Group 1. Thanks to angiogenesis and neurogenesis stimulation using Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT), in all 48 (100%) cases, cerebral blood supply and microcirculation improved, cerebral involutive and atrophic changes decreased. Patients showed persistently decreasing dementia, cognitive and mental abilities improvement. The vast majority began to correspond to the group with a milder disease stage. Test Group 2. Due to angiogenesis and neurogenesis stimulation, all 14 (100%) cases demonstrated stable dementia reduction, restoration of cognitive, mental functions and daily life activities. Conclusion: Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) is an effective, physiologically based method of stimulating cerebral angiogenesis and neurogenesis for Alzheimer's Disease and Binswanger's Disease patients. Due to complex laser exposure, patients show cerebral collateral and capillary revascularization, tissue metabolism improvement and cerebral regenerative processes development. Clinically, this leads to stable dementia level decrease, cognitive functions restoration and improvement in patients’ quality of life. The resulting clinical effect lasts for many years.

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

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. In the strong coupling regime, surface plasmon polaritons (SPPs) of metal nanoparticles interact with excitons of quantum dots or organic dyes and plasmon–exciton hybrid states called plexcitons are formed. Until now, various shaped metal nanoparticles such as nanorods, core–shell nanoparticles, hollow nanoparticles, nanoprisms, nanodisks, nanorings, and nanobipyramids have been synthesized to generate plasmon–exciton mixed states. However, in order to boost plasmon–exciton interaction at nanoscale dimensions and expand the application of plexcitonic nanocrystals in a variety of fields such as solar cells, light emitting diodes, and nanolasers, new plexcitonic nanocrystals with outstanding optical and chemical properties remain a key goal and challenge. Here we report laser-assisted synthesis of decahedral shaped noble metal nanocrystals, tuning optical properties of the decahedral shaped nanocrystals by galvanic replacement reactions, colloidal synthesis of bimetallic decahedral shaped plexcitonic nanocrystals, and strong plasmon–plasmon interaction in bimetallic decahedral shaped noble metal nanocrystals near a metal film. We photochemically synthesize decahedral Ag nanoparticles from spherical silver nanoparticles by using a 488 nm laser. The laser assisted synthesis of silver nanoparticles yields decahedral (bicolored) and prism (monocolored) shaped silver nanocrystals. The decahedral shaped nanoparticles were selectively separated from prism shaped nanoparticles by centrifugation. The optical properties of decahedral nanocrystals were tuned by the galvanic replacement reaction between gold ions and silver atoms. Excitons of J-aggregate dyes and SPPs of decahedral bimetallic nanoparticles strongly couple and hence decahedral shaped plexcitonic nanoparticles are prepared. In addition, localized SPPs of decahedral shaped bimetallic nanocrystals interact strongly with the propagating SPPs of a flat silver film and hence new hybrid plasmonic modes (plasmonic nanocavities) are generated. The experimental results are further fully corroborated by theoretical calculations including decahedral shaped plexcitonic nanoparticles and decahedral nanoparticles coupled to flat metal films.

Modeling and Simulation of Optically Gated TFET for Near Infra-Red Sensing Applications and Its Low Frequency Noise Analysis

In this paper, optically gated Tunnel Field Effect Transistor (TFET), operating on the principle of band-to-band tunneling, is designed for sensing closely spaced spectral wavelengths (~100nm) in the near-infrared region of spectrum (1– $0.7~\mu \text{m}$ ) at low intensity of illumination ( $\! /cm2). A photogenerated voltage, gate charge and semi-conductor charge models have been respectively developed to illustrate device operation. A higher illumination current, lower threshold voltage, steeper sub-threshold swing (SS) and higher ION/IOFF of the proposed device, under the incident radiation, makes it compatible for low power operation with optimum performance. This device achieved a high sensitivity of 26.52 by utilizing the advantages of TFETs. On being exposed to different concentrations of uniform and Gaussian interface traps, the performance comparison is observed in terms of ION, IOFF and SS. Gaussian trap is more susceptible to device performance degradation. Further, the low both the cases, the $\text{S}_{ID}$ is in the range of 10−18 to 10−16 A2/Hz for all the considered trap concentrations which is comparatively low. Finally, the comparison of $\text{S}_{ID}$ of the proposed device with the published works is done.

Perylene diimide based low band gap copolymers: synthesis, characterization and their applications in perovskite solar cells

In this study, newly designed perylene diimide based polymers P1 and P2 were synthesized and were used as hole transporting materials in place of the more common spiro-OMeTAD in perovskite solar cells. The co-polymers P1-P2 were synthesized by Suzuki and direct arylation polymerizations of 2,9-bis(7-bromo-9,9-dioctyl-9H-fluoren-2-yl)anthra[2,1,9-def:6,5,10-d’e’f’]diisoquinoline-1,3,8,10(2H,9H)-tetrone M1 with 5,11-bis(2-hexyldecyl)-3,9-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,11-dihydoindolo[3,2-b]carbazole M2 and 3-octylthiophene M3, respectively. P1 and P2 exhibit broad absorption spectra in thin film and solution with the absorption extending from the ultraviolet to visible and near infrared region of the solar spectrum. The water contact angles of P1-P2 were determined to be 100.8° and 122.9°, respectively, showing good hydrophobicity for the synthesized copolymers. Both polymers show steady state photoluminescence quenching when blended with perovskite. Perovskite solar cell devices fabricated using P1-P2 in place of spiro-OMeTAD show power conversion efficiencies of 13.02% and 10.74%, respectively and manifest the potential of this class of materials as promising alternatives to conventionally used spiro-OMeTAD.

Modeling broadband cloaking using 3D nano-assembled plasmonic meta-structures.

The concept of "cloaking" an object is a very attractive one, especially in the visible (VIS) and near infra-red (NIR) regions of the electromagnetic spectrum, as that would reduce the visibility of an object to the eye. One possible route to achieving this goal is by leveraging the plasmonic property of metallic nanoparticles (NPs). We model and simulate light in the VIS and NIR scattered by a core of a homogeneous medium, covered by plasmonic cloak that is a spherical shell composed of gold nanoparticles (AuNPs). To consider realistic, scalable, and robust plasmonic cloaks that are comparable, or larger, in size to the wavelength, we introduce a multiscale simulation platform. This model uses the multiple scattering theory of Foldy and Lax to model interactions of light with AuNPs combined with the method of fundamental solutions to model interactions with the core. Numerical results of our simulations for the scattering cross-sections of core-shell composite indicate significant scattering suppression of up to 50% over a substantial portion of the desired spectral range (400 - 600 nm) for cores as large as 900 nm in diameter by a suitable combination of AuNP sizes and filling fractions of AuNPs in the shell.

APPLICATIONS OF CHEMICALLY SYNTHESIZED CUS: PBO ALLOYED THIN FILMS IN MULTILAYER SOLAR CELLS AND OPTOELECTRONICS

CuS: PbO, alloyed thin films were successfully deposited on glass substrates under the deposition condition of 40oC of NaOH solution, using two solution based methods: successive ionic layer adsorption and reaction (SILAR) and solution growth technique. The crystallographic studies were done using X-ray diffractometer (XRD) and scanning electron microscope (SEM). The deposited alloyed samples were annealed at 250oC and 1500C. using Master Chef Annealing Machine. Rutherford backscattering Spectroscopy (RBS) analysis confirmed the percentage of the elements of copper, lead, sulphur and oxygen in the alloyed thin films. The optical characterization was carried out using UV-1800 double beam spectrophotometer. Sample cp1 annealed at 250 oC has an optical transmittance of 27% -71% in the ultraviolet region, 71%-83% in the visible and 83%-88% in the near infrared regions of electromagnetic spectrum. The alloyed thin films of samples cp2 of CuS:PbO annealed at 150oC, show optical transmittance of 15%-61% in the ultraviolet region, 61%-59% in the visible, and becomes linear through the near-infrared regions of electromagnetic spectrum. The two samples, have equal direct wide band gap of 3.65±0.05eV. From the spectral qualities, these compounds alloyed thin films may found useful in passive layer in heat and cold mirror application, vulcanization in tyre production due its thermal stability, active multilayer in various types of solar cells, liquid crystal displays, flat panel displays for optoelectronic applications and gas censor applications.

Study of the Optical Characteristics of Aluminim Doped Zno Thin Film

In this work, the study on the influence of the aluminium on the optical properties of ZnO thin film was carried out with a focus on the influence of variation of aluminium ions on the optical behaviour of the ZnO thin film. The film was deposited on the glass substrates by chemical bath deposition technique and aluminium was used in the following varied quantity 0.1, 0.2, and 0.3M to dope the thin films respectively. The solutions were prepared using zinc sulphate, ammonia and Hexamine with aluminium nitrate. The optical characteristics of the film such as the spectral absorbance, reflectance and transmittance within the ultraviolet and near infra-red region of electromagnetic wave spectra were investigated using UV-VIS spectroscopy with the energy band gap found to be in the range of 3.5eV to 3.9eV.

Demonstration of low loss β -Ga2O3 optical waveguides in the UV–NIR spectra

In this paper, we report the fabrication of low loss beta-phase gallium oxide (β-Ga2O3) optical waveguides and the propagation loss analysis of the waveguides in the ultraviolet (UV) to near infrared (NIR) spectral region. The β-Ga2O3 thin films were grown on sapphire substrates using metal organic chemical vapor deposition and were fabricated into various waveguide structures using nanofabrication processes. A low propagation loss of 3.7 dB/cm was obtained on the β-Ga2O3 waveguide at the wavelength of 810 nm, which is comparable to the state of the art. Combined with theoretical simulations, various loss mechanisms from two-photon absorption, sidewall scattering, top surface scattering, and bulk scattering were discussed for β-Ga2O3 waveguides, and their contributions to the total optical loss were estimated. These results show that β-Ga2O3 is a promising optical material for the fabrication of various integrated photonic devices in the UV–NIR spectra region.

Is it possible to discern Striga weed (Striga hermonthica) infestation levels in maize agro-ecological systems using in-situ spectroscopy?

The invasion by Striga in most cereal crop fields in Africa has posed a significant threat to food security and has caused substantial socioeconomic losses. Hyperspectral remote sensing is an effective means to discriminate plant species, providing possibilities to track such weed invasions and improve precision agriculture. However, essential baseline information using remotely sensed data is missing, specifically for the Striga weed in Africa. In this study, we investigated the spectral uniqueness of Striga compared to other co-occurring maize crops and weeds. We used the in-situ FieldSpec® Handheld 2™ analytical spectral device (ASD), hyperspectral data and their respective narrow-band indices in the visible and near infrared (VNIR) region of the electromagnetic spectrum (EMS) and four machine learning discriminant algorithms (i.e. random forest: RF, linear discriminant analysis: LDA, gradient boosting: GB and support vector machines: SVM) to discriminate among different levels of Striga (Striga hermonthica) infestations in maize fields in western Kenya. We also tested the utility of Sentinel-2 waveband configurations to map and discriminate Striga infestation in heterogenous cereal crop fields. The in-situ hyperspectral reflectance data were resampled to the spectral waveband configurations of Sentinel-2 using published spectral response functions. We sampled and detected seven Striga infestation classes based on three flowering Striga classes (low, moderate and high) against two background endmembers (soil and a mixture of maize and other co-occurring weeds). A guided regularized random forest (GRRF) algorithm was used to select the most relevant hyperspectral wavebands and vegetation indices (VIs) as well as for the resampled Sentinel-2 multispectral wavebands for Striga infestation discrimination. The performance of the four discriminant algorithms was compared using classification accuracy assessment metrics. We were able to positively discriminate Striga from the two background endmembers i.e. soil and co-occurring vegetation (maize and co-occurring weeds) based on the few GRRF selected hyperspectral vegetation indices and the GRRF selected resampled Sentinel-2 multispectral bands. RF outperformed all the other discriminant methods and produced the highest overall accuracy of 91% and 85%, using the hyperspectral and resampled Sentinel-2 multispectral wavebands, respectively, across the four different discriminant models tested in this study. The class with the highest detection accuracy across all the four discriminant algorithms, was the “exclusively maize and other co-occurring weeds” (>70%). The GRRF reduced the dimensionality of the hyperspectral data and selected only 9 most relevant wavebands out of 750 wavebands, 6 VIs out of 15 and 6 out of 10 resampled Sentinel-2 multispectral wavebands for discriminating among the Striga and co-occurring classes. Resampled Sentinel-2 multispectral wavebands 3 (green) and 4 (red) were the most crucial for Striga detection. The use of the most relevant hyperspectral features (i.e. wavebands and VIs) significantly (p ≤ 0.05) increased the overall classification accuracy and Kappa scores (±5% and ±0.2, respectively) in all the machine learning discriminant models. Our results show the potential of hyperspectral, resampled Sentinel-2 multispectral datasets and machine learning discriminant algorithms as a tool to accurately discern Striga in heterogenous maize agro-ecological systems.

Cholesteric–azobenzene liquid crystalline copolymers: design, structure and thermally responsive optical properties

We report the synthesis of new functional cholesteric–azobenzene side-chain liquid crystalline copolymers and terpolymers, their temperature-responsive mesophase behavior, and stimuli responsive photonic properties from 400 nm to the near infra-red region of the electromagnetic spectra.