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Calcination temperature is a crucial parameter that can be easily controlled to induce a change in material properties. Herein, iron tungstate (FeWO4) was synthesized via a hydrothermal method using iron(II) sulfate heptahydrate and sodium tungstate dihydrate as precursors and calcined at the temperature between 300 oC and 700 oC. With increasing calcination temperature, the saturation magnetization of FeWO4 nanoparticles decreased from 6.6 emu/g for FeWO4 to 0.4 emu/g for FeWO4_700, whereas their band gaps increased from 1.95 eV for FeWO4 to 2.20 eV for FeWO4_700. More crystallinity and crystal defects, and morphological changes at higher calcination temperatures contributed to varying magneto-optical properties of FeWO4 nanoparticles. [ABSTRACT FROM AUTHOR]

Human skin acts as a protective barrier, preserving bodily functions and regulating water loss. Disruption to the skin barrier can lead to skin conditions and diseases, emphasizing the need for skin hydration monitoring. The gold-standard sensing method for assessing skin hydration is the Corneometer, monitoring the skin's electrical properties. It relies on measuring capacitance and has the advantage of precisely detecting a wide range of hydration levels within the skin's superficial layer. However, measurement errors due to its front end requiring contact with the skin, combined with the bipolar configuration of the electrodes used and discrepancies due to variations in various interfering analytes, often result in significant inaccuracy and a need to perform measurements under controlled conditions. To overcome these issues, we explore the merits of a different approach to sensing electrical properties, namely, a tetrapolar bioimpedance sensing approach, with the merits of a novel optical sensing modality. Tetrapolar bioimpedance allows for the elimination of bipolar measurement errors, and optical spectroscopy allows for the identification of skin water absorption peaks at wavelengths of 970 nm and 1450 nm. Employing both electrical and optical sensing modalities through a multimodal approach enhances skin hydration measurement sensitivity and validity. This layered approach may be particularly beneficial for minimising errors, providing a more robust and comprehensive tool for skin hydration assessment. An ex vivo desorption experiment was carried out on fresh porcine skin, and an in vivo indicative case study was conducted utilising the developed optical and bioimpedance sensing devices. Expected outcomes were expressed from both techniques, with an increase in the output of the optical sensor voltage and a decrease in bioimpedance as skin hydration decreased. MLR models were employed, and the results presented strong correlations (R-squared = 0.996 and p-value = 6.45 × 10−21), with an enhanced outcome for hydration parameters when both modalities were combined as opposed to independently, highlighting the advantage of the multimodal sensing approach for skin hydration assessment. [ABSTRACT FROM AUTHOR]

The Biomass Proxy is a new cloud-free vegetation monitoring product that offers timely and analysis-ready data indicative of above-ground crop biomass dynamics at 10m spatial resolution. The Biomass Proxy links the consistent and continuous temporal signal of the Sentinel-1 Cross Ratio (CR), a vegetation index derived from Synthetic Aperture Radar backscatter, with the spatial information of the Sentinel-2 Normalized Difference Vegetation Index (NDVI), a vegetation index derived from optical observations. A global scaling relationship between CR and NDVI forms the basis of a novel fusion methodology based on static and dynamic combinations of temporal and spatial responses of CR and NDVI at field level. The fusion process is used to mitigate the impact on product quality of low satellite revisit periods due to acquisition design or persistent cloud coverage, and to respond to rapid changes in a timely manner to detect environmental and management events. The resulting Biomass Proxy provides time series that are continuous, unhindered by clouds, and produced uniformly across all geographical regions and crops. The Biomass Proxy offers opportunities including improved crop growth monitoring, event detection, and phenology stage detection. [ABSTRACT FROM AUTHOR]

The increasing viral species have ruined people's health and the world's economy. Therefore, it is urgent to design bio-responsive materials to provide a vast platform for detecting a different family's passive or active virus. One can design a reactive functional unit for that moiety based on the particular bio-active moieties in viruses. Nanomaterials as optical and electrochemical biosensors have enabled better tools and devices to develop rapid virus detection. Various material science platforms are available for real-time monitoring and detecting COVID-19 and other viral loads. In this review, we discuss the recent advances of nanomaterials in developing the tools for optical and electrochemical sensing COVID-19. In addition, nanomaterials used to detect other human viruses have been studied, providing insights for developing COVID-19 sensing materials. The basic strategies for nanomaterials develop as virus sensors, fabrications, and detection performances are studied. Moreover, the new methods to enhance the virus sensing properties are discussed to provide a gateway for virus detection in variant forms. The study will provide systematic information and working of virus sensors. In addition, the deep discussion of structural properties and signal changes will offer a new gate for researchers to develop new virus sensors for clinical applications. [ABSTRACT FROM AUTHOR]

The ionic radius of R3+ ion plays a significant role in enhancing the structural, electrical, and dielectric properties of rare-earth chromites RCrO3; In this present study, RCrO3 (R = La, Y, Gd) was synthesized using the solid-state route reaction method. The XRD pattern confirmed the formation of a single phase. Refined XRD data revealed an orthorhombic crystal structure with the space group Pbnm at room temperature, along with the corresponding lattice parameters. Further analysis using diffuse reflectance UV-visible spectroscopy showed absorption peaks and a dual direct band gap, suggesting a semiconducting nature for the samples. To investigate the electrical properties of RCrO3, dielectric and impedance spectroscopy measurements were conducted at room temperature. Notably, the variation of ionic radii R3+ plays a significant role in the structural, optical, and dielectric properties of the material. Furthermore, AC conductivity measurement conducted in the higher frequency range provides insights into the conduction mechanism of the sample, and M- H curve indicates ferromagnetic behavior, and this variation is attributed to the effect of ionic radii. [ABSTRACT FROM AUTHOR]

Herein, a flexible Poly(methyl methacrylate) (PMMA)/ polyaniline (PANi) blend nanocomposite consisting of zinc ferrite (ZnFe2O4) nanoparticles was developed utilizing a casting solution and co-precipitation techniques. X-ray diffraction (XRD) technique showed that all PMMA/PANi/ x wt % ZnFe2O4 polymers have a typical amorphous structure. The high-resolution transmission electron microscopy (HRTEM) and XRD techniques revealed that the average crystallite size of ZnFe2O4 is 19 nm. UV diffuse reflectance spectrophotometry technique was applied to study PMMA/PANi optical characteristics variations up on doping with different amounts of ZnFe2O4. The direct and indirect Eg values for PMMA polymer are 4.94 and 4.79 eV, respectively. As PMMA loaded with PANi, the Eg values decreased to 4.89 and 4.68 eV, respectively. The direct and indirect Eg values attained their lowest values of 4.28 and 3.64 eV as the amount of ZnFe2O4 became 2.5 wt % in the PMMA/PANi matrix. Enrichments in the whole linear/nonlinear optical parameters are accomplished by PANi/ZnFe2O4 doping. The fluorescence (FL) data of PMMA/PANi/x wt% ZnFe2O4 were studied in detail. As the percentage of ZnFe2O4 in the polymer matrix increased to 0.5 wt% in the polymer matrix, the maximum energy density value was achieved. The ac conductivity reached its highest value (3.25 × 1010 s−1 at 5.41 eV) as the amount of ZnFe2O4 became 2.5 wt % in the polymer matrix. Taking into account the findings of this study, the proposed: PMMA/PANi/x wt % ZnFe2O4 are considered great prospects for numerous applications. [ABSTRACT FROM AUTHOR]

Silicon dioxide and graphene oxide nanomaterials (SiO2–GO) NMs were mixed with reinforcing ternary blend polymer, polyacrylamide (PAAm) blended with polyvinyl pyrrolidone (PVP) and poly (vinyl alcohol) (PVA). PAAm–PVP–PVA. Several loading ratios of SiO2 nanoparticles and syntheses GO nanosheets (SiO2–GO) NMs (SiO2–GOx) (x = 0, 0.01, 0.03, and 0.05 wt%) were loaded to reinforce and fabricated novel glass of the fabricated as quinary-based-hybrid nanocomposites using advanced acoustic-sonication-casting technology. Several characterizations were used to investigate the samples: X-ray diffraction (XRD), infrared Fourier-transform spectroscopy (FTIR), optical microscopy (OM), field emission scanning electron microscope (FESEM), UV–visible spectrophotometer, electrical meter, antibacterial activity, and gamma-ray detection. Significant bonds between the component matrix were exhibited in FTIR spectra, with acceptable homogeneity grainy and rough surfaces that defected using FESEM within the keep of good transparency as presented by OM. XRD patterns for samples showed a similar behavior of PAAm with shifting. NMs contribution revealed significant modification of the structure, the disappearance of surface creaks, and notable improvements in the properties of quinary hybrid nanocomposites. Absorption behavior significantly enhanced at (200 nm) up to 37%. The energy gap improved by 10% and 19% for allowed indirect and forbidden indirect transitions, respectively. The dielectric and loss constants were notably enhanced up to 273%. Excellent improvement was presented in the electrical conductivity results, reaching up to 207%. SiO2 and GO NMs exhibited notable changes in inhibited zone antibacterial activity from 00 up to 27 and 25 mm of Staphylococcus aureus, Escherichia coli, respectively, compared to the polymer matrix. Samples exhibited significant attention to gamma radiation rays up to 145%. These findings presented promising materials for various requirements, such as solar cells, biology sensors, and light shielding applications. [ABSTRACT FROM AUTHOR]

This work describes the straightforward solvothermal microwave irradiation approach utilized to create pure and variable quantities of Fe doped CuO nanoparticles, as well as the experimental methods used to characterize their structural properties. The chemical, physical, and structural features of the nanoparticles were characterized using a wide variety of methods. The crystal structure, lattice properties, and crystallite size of the pure and Fe-doped CuO nanoparticles produced were confirmed by powder X-ray diffraction investigation. Analyzing the produced nanoparticles using Energy Dispersive X-ray Absorptiometry confirmed their atomic percentage and stoichiometry. The band gap and absorption were calculated from the items' measured UV–visible spectra. Photoluminescence tests confirmed the materials' stated green emission. Surface morphology and nanoparticles quality is assessed by SEM. Transmission electron microscopy can assess particle size and dispersion. The temperature dependence of the dielectric characteristics of nanoparticles was studied. It has been shown that CuO nanoparticles, both undoped and Fe-doped possess applications like power generation, circuitry, telecommunication, optical and photovoltaic device. [ABSTRACT FROM AUTHOR]

Employing the Quantum Espresso computational tool and Monte Carlo simulation, we conducted an extensive investigation into the electronic, magnetic, and optical properties of the S r 2 C r O s O 6 (SCOsO) compound. Our analysis revealed its semiconductor nature with a direct band gap and the presence of spin-down states at the Fermi level. Notably, the Hubbard parameter (U) significantly influenced the magnetic states, illustrating its role in modulating the magnetic moments within the material. The computed exchange interactions using the Ising model unveiled distinct magnitudes for Cr - Cr , Os-Os, and Os-Cr interactions, reflecting variations in electronic interactions within the compound. The temperature-dependent magnetization and susceptibility demonstrated a critical temperature of 634 K , marking a significant ferrimagnetic to paramagnetic phase transition. SCOsO exhibited a significant magnetocaloric properties, displaying substantial values of maximum magnetic entropy change Δ S M and Relative Cooling Power (RCP) under an applied magnetic field of 2 T , outperforming various other compounds in this category. Regarding optical properties, our analysis using Quantum Espresso revealed SCOsO's strong reflectivity for green light, indicating its potential for solar light storage. The refractive index displayed distinct variations, suggestive of electronic transitions influenced by the spin–orbit coupling of C r and O s ions within the compound. [ABSTRACT FROM AUTHOR]

We report the fabrication and characterization of a plasmonic metasurface comprising electrically-contacted sub-wavelength gold dipole nanoantennas, conformally coated by a thin hafnia film, an indium tin oxide layer and a backside mirror, forming metal–oxide–semiconductor (MOS) capacitors, for use as an electrically-tunable reflectarray or metasurface. By voltage biasing the nanoantennas through metallic connectors and leveraging the carrier refraction effect in the MOS capacitors, our measurements demonstrate phase control in reflection over a range of about 30°, with a constant magnitude of reflection coefficient of 0.5, and the absence of secondary lobes. Comprehensive electromagnetic and quantum carrier models of the structure are developed and are in excellent agreement with the measurements. The metasurface holds promise for use as an optical phased array. [ABSTRACT FROM AUTHOR]

Diamond-like carbon (DLC) has attracted much attention due to its unique properties such as high chemical inertness, optical transparency, and high biocompatibility. In this study, the total gas flow rate was kept constant, while the ratio of reactive gases was varied to deposit nitrogen-doped diamond-like carbon thin films on glass substrates using radiofrequency plasma-enhanced chemical vapor deposition. The effects of the gas flow ratio on the composition, microstructure, surface morphology, and optical properties of the thin films were investigated through extended deposition times. It was found that with an increase in the nitrogen-to-methane gas flow ratio, the film surface became smoother and more compact. The maximum transmittance in the visible range reached 90%, and the highest and lowest transmittance in the same ultraviolet wavelength region differed by up to 25.62% among several sample groups. The optical bandgap decreased from 3.58 eV to 3.46 eV, contrary to the trend of the sp2 fraction variation. Compared with other studies, this study considered the preparation of nitrogen-doped diamondoids using a chemical vapor deposition method with a lesser total gas flow rate passed into it, which provides practical data reference value for the preparation of N-DLC. [ABSTRACT FROM AUTHOR]

Abstract Current understanding of the ammonia distribution in Jupiter's atmosphere is provided by observations from major ground‐based facilities and spacecraft, and analyzed with sophisticated retrieval models that recover high fidelity information, but are limited in spatial and temporal coverage. Here we show that the ammonia abundance in Jupiter's upper troposphere, which tracks the overturning atmospheric circulation, can be simply, but reliably determined from continuum‐divided ammonia and methane absorption‐band images made with a moderate‐sized Schmidt‐Cassegrain telescope (SCT). In 2020–2021, Jupiter was imaged in the 647‐nm ammonia absorption band and adjacent continuum bands with a 0.28‐m SCT, demonstrating that the spatially resolved ammonia optical depth could be determined with such a telescope. In 2022–2023, a 619 nm methane‐band filter was added to provide a constant reference against which to correct the ammonia abundances (column‐averaged mole fraction) for cloud opacity variations. These 0.28‐m SCT results are compared with observations from: (a) the MUSE instrument on ESO's Very Large Telescope (b) the TEXES mid‐infrared spectrometer used on NASA's InfraRed Telescope Facility; and (c) the Gemini telescopes, and are shown to provide reliable maps of ammonia abundance. Meridional and longitudinal features are examined, including the Equatorial Zone (EZ) ammonia enhancement, the North Equatorial Belt depletion, depletion above the Great Red Spot, and longitudinal enhancements in the northern EZ. This work demonstrates meaningful ammonia monitoring can be achieved with small telescopes that can complement spacecraft and major ground‐based facility observations.

The utilization of actual biological tissue (e.g., pork meat samples) and tissue-mimicking phantoms for optical-based in-body data and energy transfer studies is crucial. Near-infrared (NIR) light, a part of the light spectrum that falls between visible light and infrared, is highly advantageous as a carrier for data transmission due to its superior ability to penetrate biological tissue, for instance, the human body. Using pork meat samples as a propagation medium for prolonged experiments is challenging due to the deterioration of meat quality caused by drying in the temperature chamber. Typically, a controlled-temperature chamber can be utilized to warm the tissue samples to 37 °C. Some experiments need to be carried out over long periods, in some cases exceeding one hour, including the demonstration of transmitting large-size data (e.g., high-definition images or videos) in real-time through biological tissue using NIR LED. Moreover, for statistical analysis, some experiments need to be repeated, therefore degradation of the tissue sample should be avoided. Furthermore, experiments may also encompass investigations into optical wireless power transfer (OWPT) conducted on biological tissues under NIR illumination and employing energy harvester-based commercial photovoltaic cells (PV) at the receiving ends, which would require a long time to charge the storage (e.g., battery or supercapacitor) fully. Using phantoms for such an experiment is also not straightforward, requiring careful consideration, such as standardization issues. One possible approach to address this challenge is to conduct experiments in a free-space environment (e.g., sample-free) while guaranteeing that the optical power received in free-space is equivalent to that obtained through biological tissue. This can be achieved by carefully controlling the LED's current and arranging the optical channel's distance to achieve comparable results. The received optical power is the primary parameter for comparing free-space and biological tissue setups. This dataset provides settings for NIR LEDs (Pmax = 375 mW and λ = 810 nm), allowing in-body communication experiments in a free-space environment. The LED's current settings in this dataset (free-space) are equivalent in comparison to those used in a test-bed using biological tissue with 5 (five) different variations of LED currents (i.e., 500 mA, 400 mA, 300 mA, 200 mA, and 100 mA). The dataset consists of six pork meat samples with different thicknesses and fat-muscle layer compositions, resulting in 36 data points. This dataset holds significant potential for reuse in any biomedical research, particularly in the fields of in-body communication and energy transfer utilizing light.

Titanium dioxide (TiO2) has attracted much attention because of their desirable physicochemical properties especially in the water splitting process. In this work pure and Fe-doped TiO2 compounds are studies theoretically with the help of Generalized Gradient Approximation with the revised Pardew–Burke–Ernzerh (RPBE) exchange–correlation scheme. Total Density of States (TDOS) and Partial Density of States (DOS) were analyzed in detail which show that iron (Fe) and oxygen (O) orbitals hybridize, especially in the region of the doping system conduction band minima for both modes. Additionally, this interaction produces an energy level that effectively reduces the bandgap of the adsorbed system. Optical properties were elucidated which shows that Fe-doped TiO2 system results in high absorption and photoconductivity. Moreover, the results demonstrate low bandgap energy which is suitable for the reduction in water splitting without the need for external energy. Magnetic properties demonstrated that Fe-doped TiO2 systems show very low diamagnetic responses. The calculated elastic properties of Fe-doped TiO2 indicate ductile nature of the material with a strong average bond strength. Fe-doped TiO2 exhibited less microcracks with a mechanically stable composition.

Cs2BiAgI6 is a lead-free inorganic perovskite material exhibits exceptional photoelectric characteristics and great environmental stability. HTL/Cs2BiAgI6is/ETLs solar cells was investigated numerically by using SCAPS 1-D Capacitance Simulator. IGZO, TiO2, WO3, MoO3, and SnO2 have been chosen as ETLs, while CuO, CuI, and MoO3 are as HTLs. The values of electrical parameters were calculated as function of thickness of the absorber layer, ETLs, HTLs, interface defect densities, doping densities, and working temperature. Comparative study shows that best configuration of obtain solar cell is MoO3/Cs2BiAgI6/IGZO. The obtain value of Jsc, Voc, FF and PCE are 23.80 mA/cm2, 1.193 V, 83.46 %, 23.711 % respectively. The value of quantum efficiency is 80–90 % in the range of 350–750 nm. These results will open the door for the widespread use of stable and environmentally friendly perovskite solar cells by providing theoretical recommendations for high performance of Cs2BiAgI6 based photovoltaic solar cells (PSCs).

Abstract Neuromorphic sensors have inherently‐fast speeds and low data rates, which potentially make them ideal for the observation of transient sources, such as lightning and sprites. Particularly, for remote observations. In this article, we report the first observations of sprites from the ground with a neuromorphic sensor. These observations are accompanied by measurements with established instruments such as low‐light level and high‐frame rate cameras. We determine that neuromorphic sensors can capture sprites and determine their duration to an accuracy of roughly 6 ms. Average sprite durations were found to be 55 ms within our data set. We have also ascertained that sprites may be too dim for the neuromorphic sensors to resolve the internal spatiotemporal dynamics, at least without the aid of intensifiers.

This is a theoretical study of boron-doped single-walled carbon nanotubes. The same topology of primitive nanodomains, located at different positions on single-walled carbon nanotubes, leads to different electronic band structures. We propose a ϕ term. Density functional theory was corrected for van der Waals interactions and used to carry out the periodic boundary condition geometry optimization, where boron formed the topologies of primitive nanodomains. The calculated bulk structure and local structure spectroscopic parameters can be used for comparison with experimental results to confirm the theoretical models.

Over the previous decade, there has been a significant focus on researching underwater acoustic sensor networks (UW-ASNs) for a diverse range of underwater applications, which in turn has facilitated human exploration of the expansive underwater environment. This research introduces an innovative architectural approach that signifies a noteworthy advancement. By combining both acoustic and optical components, it establishes an underwater wireless sensor network. Additionally, the research introduces an innovative multiple levels Q learning-grounded direction-finding procedure, denoted as the proposed system Multi-layer Guidance Approach (MLGA) which is meticulously tailored for such underwater networks. The network's architecture encompasses both physical grouping and logical division into two tiers: the upper tier is overseen by group leaders responsible for managing routing within the lower tier, where group members execute the actual data packet routing. This design capitalizes on the wider viewpoint of upper-tier group leaders and the concurrent learning processes occurring across all groups, resulting in a substantial enhancement in routing efficiency in comparison with traditional methodologies. The empirical results obtained from experimental tests underscore the robustness of the proposed system when confronted with changes in network topology. Moreover, it showcases the system's ability to achieve higher delivery rates and reduced delays in dynamic networks compared to the established approach of flat Q-learning routing. This innovative strategy holds the potential to significantly push the boundaries of underwater sensor networks, surpassing the constraints of conventional communication methods and providing a more effective and dependable means of transmitting data underwater. This advancement not only contributes to the technical aspects but also holds promise for fostering greater exploration and understanding of underwater environments.

The significance of the ocean in scientific research and military applications is growing, with submarines being pivotal for exploration and naval operations. However, the challenge of wireless communication with submerged submarines due to the strong absorption and scattering of electromagnetic waves in seawater limits their utility. This paper addresses the need for submarine communication methods characterized by speed, stability, cost-effectiveness, and long-range capabilities. It provides a comprehensive overview of current and potential future submarine communication techniques, including electromagnetic, acoustic, and optical methods, analyzing their performance in various channel complexities and discussing their advantages and drawbacks. Additionally, emerging technologies such as magnetic, translational acoustic-RF (TARF), photo/thermo-acoustic (PA/TA), neutrino, and quantum communication are explored, showing promise for the future of submarine communication systems. The upcoming generation of communication technology may establish a three-dimensional communication network connecting land-based stations, buoys, drones, satellites, and submarines to enhance the efficiency and reach of underwater communication.

The unmanned aerial vehicle (UAV) based remote sensing has drawn increased attention in precision agriculture. Lightweight optical and thermal sensors have been used widely on UAVs for a range of applications, and have been proposed by some as the best approach to map soil moisture at farm scales. However, passive microwave remote sensing has been widely acknowledged as the most accurate soil moisture mapping technology, and adopted by the soil moisture and ocean salinity and soil moisture active and passive satellite missions. Accordingly, it is postulated that this will also be the best technique for UAV-based near-surface soil moisture remote sensing, overcoming the spatial resolution limitation from low earth orbit altitude. Being so far limited by sensor availability, only a small number of studies have illustrated the potential of UAV-based near-surface soil moisture mapping using L-band microwave radiometers, and there has been no direct comparison with the thermal-optical alternative. To guide the design of future UAV-based soil moisture mapping systems, airborne optical, thermal infrared, and passive microwave observations collected from a scientific aircraft at low altitude over a center-pivot irrigation farm in Tasmania, Australia were used in this study to simulate UAV-based observations, and the performances of the thermal-optical and microwave techniques when compared at 75 m scale. The L-band microwave emission showed a superior sensitivity to near-surface soil moisture, and a higher and more consistent soil moisture retrieval accuracy than thermal-optical, with a root-mean-squared error of 0.05–0.06 m3/m3 and 0.05–0.09 m3/m3, respectively.

This research explored the crystal structure, mechanical and elastic, electronic, magnetic, and optical properties of spinel compoundsATi2S4 (A=Ca, Sr and Ba). The ferromagnetic phase of the compounds was found to be stable, and FP-LAPW method within density functional theory (DFT) was used to calculate and compare the lattice constant a, bulk modulus B0, and its pressure derivative B'. The exchange-correlation potential was also treated with both the GGA and TB-mBJ potential approximation. The results of the study showed that the examined spinels exhibit half-metallic behavior, which makes them a potential material for use in spintronic and optoelectronic devices.

Aerogels have gained increasing attention due to their unique properties since their introduction in 1932. Silica aerogel, one of the earliest and most advanced types, is known for its high transparency and excellent thermal insulation. However, its internal pearl-like structure makes it extremely brittle, which limits its practical applications. To address this, through multiple refinements in formulation and production techniques, we developed a novel Polyvinyl Alcohol (PVA) aerogel using an innovative one-step standing method. This method significantly reduces the gelling time compared to the freeze–thaw method and eliminates the need for refrigeration, making it a more environmentally friendly and sustainable process. The resulting one-step standing PVA aerogel features a hierarchical porous structure, remarkable transparency, improved strength, and enhanced thermal insulation. Mechanical tests demonstrated that the PVA aerogel produced by the one-step standing method exhibited a significantly higher Young’s modulus of 4.2596 MPa, surpassing that of silica, copper nanowire (Cu NM), and graphene aerogels. Additional tests, including transmittance and thermal analysis, further confirmed that the one-step standing PVA aerogel excels in both transparency and thermal insulation. This combination of improved mechanical performance and light transmission opens novel potential applications, such as drug delivery systems, where the aerogel’s pore structure can store drugs while maintaining strength and transparency.

Optical biosensors have emerged as a powerful tool in analytical biochemistry, offering high sensitivity and specificity in the detection of various biomolecules. This article explores the advancements in the integration of optical biosensors with microfluidic technologies, creating lab-on-a-chip (LOC) platforms that enable rapid, efficient, and miniaturized analysis at the point of need. These LOC platforms leverage optical phenomena such as chemiluminescence and electrochemiluminescence to achieve real-time detection and quantification of analytes, making them ideal for applications in medical diagnostics, environmental monitoring, and food safety. Various optical detectors used for detecting chemiluminescence are reviewed, including single-point detectors such as photomultiplier tubes (PMT) and avalanche photodiodes (APD), and pixelated detectors such as charge-coupled devices (CCD) and complementary metal–oxide–semiconductor (CMOS) sensors. A significant advancement discussed in this review is the integration of optical biosensors with pixelated image sensors, particularly CMOS image sensors. These sensors provide numerous advantages over traditional single-point detectors, including high-resolution imaging, spatially resolved measurements, and the ability to simultaneously detect multiple analytes. Their compact size, low power consumption, and cost-effectiveness further enhance their suitability for portable and point-of-care diagnostic devices. In the future, the integration of machine learning algorithms with these technologies promises to enhance data analysis and interpretation, driving the development of more sophisticated, efficient, and accessible diagnostic tools for diverse applications.

The coseismic deformation field on both sides of the fault, especially the distribution and change characteristics of near-field deformation, not only provides important constraints for the fine inversion of the slip distribution model but also serves as an important basis for the anti-disruption defense of the cross-fault linear engineering facilities. In this paper, we used Sentinel-1 satellite data to obtain the coseismic deformation field of the Maduo earthquake by using InSAR and offset techniques. We quantitatively compared the coseismic displacement of the three types of data: InSAR, offset, and optical images. The results show that optical images and offset provided more robust near-fault (<2 km) deformation insights than InSAR, which exhibited irregular deformation patterns due to incoherence near the fault. The maximum relative displacements for InSAR and offset observations are ~2.8 m and 4 m, respectively. Then we tested various fault slip models with different data constraints, revealing that a combined inversion of GPS, InSAR, and offset data offers superior constraints on slip distribution. This integrative approach effectively captured both shallow and deep fault slip, particularly near the fault zone. The eastern branch fault model, jointly constrained by GPS, InSAR, and offset data, is the optimal coseismic slip distribution model for the Maduo earthquake, and the maximum slip is 5.55 m. [ABSTRACT FROM AUTHOR]

This work aims to upgrade the functional properties of ZnMn 2 O 4 via doping with Bi3+. Nano ZnMn 2-x Bi x O 4 (x = 0, 0.03, 0.05, 0.07, 0.1, 0.15, 0.2) samples were prepared by the sol-gel method. The structure, microstructure, and formed phases in ZnMn 2-x Bi x O 4 samples were determined using Rietveld-calculated profile fitting of the experimental x-ray synchrotron radiation diffraction data. The tetragonal spinel ZnMn 2 O 4 phase was formed with a tiny (∼2–4 %) hexagonal ZnO phase. The morphology and different vibration bands in ZnMn 2-x Bi x O 4 samples were investigated using scanning electron microscopy and Fourier transform infrared techniques. The diffused reflectance technique was used to explore the effect of Bi doping on the absorbance and optical band gap of ZnMn 2 O 4. The optical band gap energy decreased from 2.42 to 1.83 eV as the percentage of Bi-doped ZMO increased from 0 to 10 %, then increased again for higher Bi content. The dielectric permittivity is affected by the Bi-doped amounts and temperature. As the amount of Bi and temperature increased, the impedance of the ZMO sample and relaxation time changed. All samples exhibited both metallic and semiconducting behaviors. All samples have a non-Debye relaxation phenomenon. Samples with x = 0.03 and 0.2 exhibited the maximum conductivity among other doped samples. These findings introduce ZnMn 2-x Bi x O 4 samples for new applications in optoelectronics and optical devices. [ABSTRACT FROM AUTHOR]

Pr3+-ion doped YF3, LaF3, and GdF3 nanoparticles (NPs) were chemically prepared at a lower temperature (80 °C) to investigate the comparative physiochemical characteristics. X-ray diffraction profile of the nanoproducts exhibited the orthorhombic phase in YF3:Pr and GdF3:Pr NPs, whereas hexagonal structure was found in LaF3:Pr NPs with an estimated crystalline size 12, 23, and 15 nm, respectively. The unit cell constants for YF3:Pr (a = 6.340 Å, b = 7.269 Å, c = 4.317 Å, and unit cell volume = 198.97 (Å)3), LaF3:Pr (a = b = 7.171 Å, and c = 7.388 Å, and unit cell volume = 329.092 (Å)3) and GdF3:Pr (a = 6.465 Å, b = 7.008 Å, and c = 4.528 Å, and unit cell volume = 205.225 (Å)3) were considered to examine the influence of the dopant ions and the host ion's ionic radius on the crystal phase, and crystallinity. An orthorhombic phase GdF3:Pr NP sample revealed better thermal stability in comparison to the hexagonal phase LaF3:Pr NPs as received in the thermogravimetric outcomes. FTIR spectra exhibited the surface-fastened water molecules which promote the development of colloidal solution in aqueous solvents under the environmental conditions as achieved in absorption spectral analysis. Band gap energy was calculated from the UV/visible spectra to examine the optical behavior of the optically active NPs. The excitation and emission spectrums demonstrated the sharp excitation and emission transitions of the doped Pr3+ ion under excitation from the blue region. Comparatively, the emission and excitation transitions of the YF3:Pr NPs were dominant with respect to the orthorhombic GdF3:Pr and hexagonal LaF3:Pr NPs. YF3:Pr NPs are a useful host matrix for the loading of the activator Pr3+-ion for their use in luminescent phosphor material development. [ABSTRACT FROM AUTHOR]

The last decade has seen a large growth in fluorescence‐guided surgery (FGS) imaging and interventions. With the increasing number of clinical specialties implementing FGS, the range of systems with radically different physical designs, image processing approaches, and performance requirements is expanding. This variety of systems makes it nearly impossible to specify uniform performance goals, yet at the same time, utilization of different devices in new clinical procedures and trials indicates some need for common knowledge bases and a quality assessment paradigm to ensure that effective translation and use occurs. It is feasible to identify key fundamental image quality characteristics and corresponding objective test methods that should be determined such that there are consistent conventions across a variety of FGS devices. This report outlines test methods, tissue simulating phantoms and suggested guidelines, as well as personnel needs and professional knowledge bases that can be established. This report frames the issues with guidance and feedback from related societies and agencies having vested interest in the outcome, coming from an independent scientific group formed from academics and international federal agencies for the establishment of these professional guidelines. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP) blended polymer loaded with (x) wt. % tetrapropylammonium iodide (TPAI) were fabricated. X-ray diffraction was used to identify the TPAI and crystallinity changes in the blend. TPAI doping's effects on the blends linear and nonlinear optical parameters were examined. The direct and indirect energy gap values of the PVA/PVP blend were reduced from (5, 4.81) eV to (4.77, 4.27) eV and from (4.72, 4.39) eV to (5.11, 4.85) eV as it doped with 25% TPAI in the case of PVA/PVP prepared with distilled water (DW) and dimethylsulfoxide (DMSO), respectively. The value of refractive index at 500 nm was enlarged from 1.32 to 2.3 for the blend doped with TPAI and increased further to 2.67 as it was prepared with DW. A small doping amount of TPAI did not produce a noteworthy alteration in the real part of the dielectric constant (εr) value. By increasing the amount of TPAI (>12.5%), εr increased considerably, with the rate of increase in the blends prepared with DW being higher than that prepared with DMSO. At 500 nm, εr of PVA/PVP increased from 1.8 to 7.11 and 5.34 as it was doped with 31.25%TPAI in the case of the blends prepared with DW and DMSO, respectively. The influences of the solvent, amount of TPAI doping, and excitation wavelength on the fluorescence intensity and emitted colors were also investigated. The maximum DC conductivity (1.89 x10−7 and 1.06 x 10−5 s m−1) was detected at 338 K as the blend was doped with 12.5 wt. % TPAI and prepared with DW and DMSO, respectively. The effects of the amount of TPAI doping and the temperature on the DC conductivity of the various blends were also explored. [ABSTRACT FROM AUTHOR]

In the present research work, we have explored amperometric sensing properties of carbon nanospheres (Cx) (5%, 8%, and 15%) decorated over Sm2O3/Co3O4 nanocomposites (NC) that are synthesized by microwave-assisted method. The synthesized electrode materials are characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM-EDAX (energy-dispersive X-ray spectroscopy), BET (Brunauer–Emmett–Teller), XPS (X-ray photoelectron spectroscopy), and UV–visible. Phase analysis revealed mixed monoclinic crystal structure and crystallite size decreases from 32 to 22 nm. Plate/flake-like morphology resulted upon the incorporation of Cx on Sm2O3/Co3O4 crystal lattice. Redshift in the optical absorption peak resulted with an increase in Cx concentration on Sm2O3/Co3O4 NC and the optical band gap (Eg) decreases from 3.26 to 2.61 eV. The sensitive and selective determination of hydrogen peroxide (H2O2) is very important because it is a product of reactions catalyzed by oxidase enzymes, a powerful effector of redox signaling, versatile biomarker, and is widely used in the food industry. H2O2 is known to cause toxicity and they form hydroxyl radicals. The accurate detection of H2O2 can indicate the presence of enzyme activity, explosives, and cell signaling pathways. Additionally, H2O2 has become a signal propagator within signal amplification methodologies used to enhance selectivity of the diagnostic assays. The developed modified sensor (C15%:Sm2O3/Co3O4) showed amperometric detection of H2O2 with 96% steady current within 3–4 s, linear range was found to be 0.2 µM to 6 µM, limit of detection (LOD) 0.04 µM, and having a sensitivity of 0.483 µA/µM (R2 = 0.996). Further, sensitivity and selectivity were detected with glucose, dopamine, ascorbic acid, and uric acid at + 0.36 V and no current response was observed. The modified electrode material possess high selectivity, less response time, high stability, reusability, and high repeatability and can find applications in the field of real-time monitoring of hazardous materials, fabrication of biosensors, H2O2 sensors, and in optoelectronics. [ABSTRACT FROM AUTHOR]

Laser interferometry is one of the most accurate measurement technologies whose displacement resolution can reach the femtometer (fm) level. With the development of Micro‐Electro‐Mechanical Systems(MEMS) technology, many excellent optical interferometric MEMS sensors have emerged, which play an essential role in intelligent manufacturing, aerospace, and many other fields. Among them, optical interferometric MEMS accelerometers develop rapidly due to their high sensitivity, low noise, and anti‐electromagnetic interference advantages. Lots of research in optical interferometric chip design, micro‐nano fabrication process, signal demodulation algorithm, and range extension technology are performed, and different types of MEMS accelerometers based on the optical interferometric principles are developed, which have been demonstrated and applied in the fields of disaster monitoring, equipment operation and maintenance, and resource exploration. This paper reviews the development status of optical interferometric MEMS accelerometers, mainly focusing on the critical problems and solutions that need to be solved in the development process of optical interferometric accelerometers, and finally introduces the typical application scenarios. [ABSTRACT FROM AUTHOR]

Cu2MgSnS4 (CMTS) nanoparticles are successfully prepared via a solvothermal approach. X-ray diffraction (XRD) and Raman reveal that pure zinc-blende CMTS phase is obtained. Scanning electron microscopy (SEM) shows that CMTS nanoparticles exhibit microsphere structure. The band gap of as-obtained CMTS nanoparticles is calculated to be 1.68eV, indicating a potential candidate for tandem solar cells. The degradation rate of methylene blue (MB) with under visible-light irradiation is about 87%, indicating that CMTS can be useful for effective visible-light photocatalyst. [ABSTRACT FROM AUTHOR]

Nickel (Ni+2) doped nanocrystalline Bi2S3 thin films are deposited on the glass substrate from the solutions containing Bismuth Nitrate, Ethylenediamine Tetraacetic acid (EDTA) and Thioacetamide at a bath deposition temperature of 318K. The optical, surface morphological and electrical properties of Ni-doped Bi2S3 thin films prepared at three different doping concentration are investigate by using ultraviolet–visible transmission spectra (UV–Vis), Scanning electron microscopy (SEM), Energy Dispersive X-ray (EDAX) and thermo-e.m.f. techniques. The optical band gap energies are found in between 2.32-2.43 eV. The SEM images show that the prepared films are continuous, dense and distributed over the entire area with good uniformity. The electrical conductivity of the films are in the order of 10-2 Ω-1 m-1 . The films are n-type as determined from the Hot Probe method. Photoconductivity studies reveal that photocurrent increases with the increase in Ni doping concentrations. Due to the absorption of photons, free electron-hole pairs (EHP) are produce. [ABSTRACT FROM AUTHOR]

SpectroPhotometric Imaging in Astronomy with Kinetic Inductance Detectors (SPIAKID) aims at designing, building, and deploying on the sky a spectrophotometric imager based on microwave kinetic inductance detectors (MKIDs) in the optical and near-infrared bands. MKIDs show a fast response and the ability to resolve photon energy compared to the conventional Charge-coupled Devices (CCDs). In this paper, we present the design and simulation of the MKID arrays for SPIAKID. The detectors consist of four arrays with each array of 20,000 lumped-element pixels, and each array will be read with 10 readout lines. The meander material of the resonators is trilayer TiN/Ti/TiN to have better uniformity of the critical temperature across the array. We also present the measurement result for a test array with 30 × 30 pixels which is a subset of the designed 2000-pixel array to verify the design and fabrication. The current measured best energy-resolving power R = E / Δ E is 2.4 at λ = 405 nm and the current medium R is around 1.7. We have also observed that the response of the TiN/Ti/TiN is much smaller than expected. [ABSTRACT FROM AUTHOR]

This study aims to explore factors related to optical navigation that interfere with the accuracy of robot-assisted surgery, specifically focusing on the TIANJI Robot system. A measurement model was created to assess the accuracy of the TIANJI Robot system in simulated screw placement. Deviation between actual and planned positions was measured using a three-coordinate machine. Various experiments were conducted to investigate the impact of different optical navigation factors on screw placement accuracy. Deviations were measured at different distances (ranging from 1.2 to 2.2 m) between the optical navigation stereo camera and the tracker, with each distance being tested 50 times. The distance between the optical camera and patient tracker was set at 1.4 m. Deviations were also measured at different angles between the camera and robot tracker, repeated over 25 times for each angle. Data were analyzed using mean and standard deviation, with line charts illustrating deviation changes based on distance and angle details. Within the range of the TIANJI Robot system’s optical navigation (1.2–2.2 m), deviation increased as distance increased (χ2 = 479.107, P < 0.001). The robotic system demonstrated high and consistent accuracy (mean deviation: 0.332 mm ± 0.067 mm) when the relative angle between the optical camera and tracker was below 40°. The accuracy of the TIANJI Robot system was found to be influenced by relative distance and angle between the optical camera and tracker during screw placement procedures. Surgeons are recommended to set a relative distance of 1.4–1.5 m between the optical camera and patient tracker, with a relative angle below 40° when placing and adjusting optical tracking devices. [ABSTRACT FROM AUTHOR]

In this paper, using density functional theory (DFT), we present a systematic computational investigation on ZrCl4 in respect of electronic, structural, optical, mechanical properties, which is of great interest in semiconductor physics. Our results show that the metal tetrachloride is a mechanically stable semiconductor with a wide indirect bandgap of EgHSE03=4.82eV (EgGGA=3.56eV). ZrCl4 could behave as a brittle material and could be covalent. According to our optical data, a reflectivity of 27.6% could suggest a good material absorption characteristic on the studied material, with a high absorption coefficient of up to 1.61×105cm−1. On the partial density of states plot, the hybridization of electron orbitals between Cl 3p5 states in the valence band and transition Zr 4d2 states in the conduction band is also observed. Our findings advance the fundamental understanding of ZrCl4 material and provide important insights in electronic/optoelectronic applications. [ABSTRACT FROM AUTHOR]

In this study, strontium chloride hexahydrate (SrCl2.6 H2O), silver nitrate (AgNO3), and thioacetamide (C2H5NS) were employed as cationic and anionic precursors in the electrochemical deposition technique for the synthesis and characterisation of strontium sulphide doped silver (SrS/Ag) thin films. The spectrum reveals the polycrystalline nature of the materials. The film displayed a significant peak at orientation (111), which corresponds to 2theta values of 26.69° for undoped SrS, and a flawless crystalline peak with a cubic phase indexed at orientations (111), (112), (200), and (211). SrS/Ag of 0.01, 0.02, and 0.03 mol correspond to 2theta values of (26.45, 33.79, 37.60, and 51.77) o respectively. Clove-like material with precipitate is visible in the SrS material's micrograph; the big nano grain on the surface of the substrate exhibits photon absorption but lacks any signs of pinholes. The materials show an increase in thickness from 126.01 to 122.02 nm and an increase in film resistivity from 1.58 × 109 to 1.69 × 109 cm, which further led to a decrease in conductivity from 6.32 × 108 to 5.91 × 108 S/m. The bandgap energy of 1.35 to 2.00 eV was obtained. [ABSTRACT FROM AUTHOR]

The industrial dye pollutants directly affect the aquatic animals and humans. Among these methylene blue (MB) dye is highly toxic, non-degradable, carcinogenic and responsible for major health issues for humans and hazardous to the environment. In present work, we were mainly put efforts for the low-cost synthesis of Cu1.8Se nanoparticles (NPs), annealed as-synthesized sample at 200 ͦ C and then utilized it for photodegradation of toxic MB dye. The structural, morphological and optical properties were studied by X-ray diffraction, TEM, SEM, EDX, UV-Visible, FTIR spectroscopy techniques. Cu1.8Se NPs crystallized in cubic structural phase with crystallites size around 20 nm. The TEM micrographs confirmed the formation of random shaped and sized particles of size ranges from 15 nm 50 nm. SEM and EDAX results showed the presence of copper (Cu) and selenium (Se) elements. The direct band gaps of sample A (as-prepared) and sample B (annealed) were found to be 2.0 and 2.1 eV, respectively. FTIR spectra showed the bands of Cu-Se bending and stretching vibrations. The photocatalytic activities against MB dye shows that Cu1.8Se NPs could serve as a potential catalyst for breaking down of MB Dye and degrade in the presence of incandescent bulb light Hence, Cu1.8Se NPs is self sufficient for the removal of dissolved toxic contaminations from the industrial waste water as well as other polluted water resources. [ABSTRACT FROM AUTHOR]

Mo1-xCoxS2 (0 ≤ x ≤ 0.1) nanoparticles were successfully synthesized by using a hydrothermal route. The crystal structure of the prepared samples was investigated by Xray diffraction (XRD), emphasizing that all the prepared samples had a hexagonal structure of MoS2, and revealed an increment in the average particle size from 5 to 8 nm with increasing the cobalt ratio. The morphology was examined using scanning electron microscopy (SEM), and the recorded images of pure and cobalt-doped MoS2 show flowerlike architecture clusters. FT-IR spectroscopy was carried out to detect functional groups and stretching and bending vibrations of chemical bonds existing in all the prepared samples, confirming the presence of Mo-O and Co-O-Co characteristic peaks. The chemical composition of the synthesized samples was determined by energy dispersive Xray (EDX) analysis. The results confirmed the presence of Mo, S, and Co, which are consistent with the proposed formation of Mo1-xCoxS2 nanosystems. Optical properties were examined by UV–Visible spectrophotometry, reflecting allowed direct transitions with an energy band gap that decreases from 1.9 eV to 1.53 eV with increasing cobalt concentration. The photocatalytic degradation efficiency of methylene blue (MB) using pure and different ratios of cobalt-doped MoS2 as catalysts was tested under visible light radiation, and it was noticed that the MB degradation increased with increasing cobalt concentration. [ABSTRACT FROM AUTHOR]

Ni-doped ZnO (NZO) thin films were prepared onto a glass substrate with varying concentrations of 2, 4, 6, 8, 10% of Ni using sol-gel spin coating method and their structural, optical and magnetic characteristics were discussed with supporting of XRD, UV, Photoluminescence, XPS and vibrating sample magnetometer (VSM) characterization techniques. The XRD analysis shows that the polycrystalline hexagonal wurtzite structure with (002) orientation of NZO thin films. The XPS results confirmed the presence of Ni ion in all the samples. The optical bandgap of the prepared samples was decreased with increasing concentrations of nickel from 3.33 to 3.22 eV. Photoluminescence spectra showed a red shift of near band edge (NBE) and deep level (DLE) emissions for prepared undoped and NZO thin films. The VSM of prepared NZO thin films exhibit ferromagnetic behavior at room temperature for potential applications in various fields. Our experimental observations support for transparent conducting electrode and spintronics device applications. [ABSTRACT FROM AUTHOR]