Measurements Of Spectra Research Articles

Exploring the structural, optical and photoluminescence of novel terbium-doped barium borosilicate glasses for high-performance technologies

The production process involved the use of the melt-quenching approach to produce a series of barium borosilicate glasses with the specific chemical formula 55B2O3+(26-x)BaO+12SiO2+7Na2O + xTb4O7, where x = 0, 0.5, 1, 2, and 3 mol%. X-ray diffraction (XRD), Raman spectroscopy, optical absorption, and photoluminescence spectra measurement were used to examine the prepared samples. X-ray diffraction revealed the non-crystalline character of the assembled samples. The Raman spectroscopy revealed that the incorporation of Tb4O7 into borosilicate glasses induced alterations in their structure. As the doping of Tb3+ ions increases, the density and molar volume of the glasses under investigation increase. Furthermore, the ion concentration and field strength increase while the polaron radius and inter-ionic distance decrease. The glass optical absorption spectra showed five peaks in the wavelength range from 300 nm to 2000 nm: 5L10, 5D3, 5D4, 7F(0, 1, 2), and 7F3, attributed to Tb3+ ion electronic transitions. In addition, optical parameters like optical energy gap, Urbach energy, refractive index, molar refractive index, reflection loss, electronic polarizability, and optical transmission coefficient were computed. Terbium-doped borosilicate glasses had a decreased optical energy gap and an improved refractive index. Photoluminescence spectra were excited at 325 nm and showed five peaks in the range of 400–750 nm. Photoluminescence (PL) emission spectra exhibit distinct peaks in the visible range.

Understanding the Vibrational Structure and Ultrafast Dynamics of the Metal Carbonyl Precatalyst [Mn(ppy)(CO)4

The solution phase structure, vibrational spectroscopy, and ultrafast relaxation dynamics of the precatalyst species [Mn(ppy)(CO)4] (1) in solution have been investigated using ultrafast two-dimensional infrared (2D-IR) spectroscopy. By comparing 2D-IR data with the results of anharmonic density functional theory (DFT) calculations, we establish an excellent agreement between measured and predicted inter-mode couplings of the carbonyl stretching vibrational modes of 1 that relates to the atomic displacements of axial and equatorial ligands in the modes and the nature of the molecular orbitals involved in M-CO bonding. Measurements of IR pump-probe spectra and 2D-IR spectra as a function of waiting time reveal the presence of ultrafast (few ps) intramolecular vibrational energy redistribution between carbonyl stretching modes prior to vibrational relaxation. The vibrational relaxation times of the CO-stretching modes of 1 are found to be relatively solvent-insensitive, suggestive of limited solvent-solute interactions in the ground electronic state. Overall, these data provide a detailed picture of the complex potential energy surface, bonding and vibrational dynamics of 1, establishing a fundamental basis for the next steps in understanding and modulating precatalyst behavior.

Modulating Electronic States of Cu in Metal-Organic Frameworks for Emerging Controllable CH4/C2H4 Selectivity in CO2 Electroreduction.

The intensive study of electrochemical CO2 reduction reaction (CO2RR) has resulted in numerous highly selective catalysts, however, most of these still exhibit uncontrollable selectivity. Here, it is reported for the first time the controllable CH4/C2H4 selectivity by modulating the electronic states of Cu incorporated in metal-organic frameworks with different functional ligands, achieving a Faradaic efficiency of 58% for CH4 on Cu-incorporated UiO-66-H (Ce) composite catalysts,Cu/UiO-66-H (Ce) and that of 44% for C2H4 on Cu/UiO-66-F (Ce). In situ measurements of Raman and X-ray absorption spectra revealed that the electron-withdrawing ability of the ligand side group controls the product selectivity on MOFs through the modulation of the electronic states of Cu. This work opens new prospects for the development of MOFs as a platform for the tailored tuning of selectivity in CO2RR.

Investigations on structural and opto-electrical characterization of Ag-TCNQ (metal-organic frameworks) as complex thin films for potential device applications

The silver- (7, 7, 8, 8-tetracyanoquinodimethane (Ag-TCNQ) organometallic complex was synthesized chemically as a nano-powder and thereafter deposited as a thin film by thermal evaporation. The monoclinic, needle-like, polycrystalline structure of the Ag-TCNQ complex was analyzed employing x-ray diffraction (XRD) and a scanning electron microscope (SEM). Whereas their chemical structure and stability were explored using Fourier transformation infrared (FTIR) techniques. The findings imply a charge transfer of degree −0.5 between TCNQ° and TCNQ−, as revealed by the shift of the bands of the C≡N stretching and the (C═C-H) bond positioned at 2198 and 824 cm−1, respectively. As well as the optical properties of Ag-TCNQ thin film were studied using spectrophotometric measuring in the wavelength ranging 200 to 2500 nm. The measurement of transmittance and reflectance spectra were employed to calculate the refractive index (n), dielectric constant, absorption index (k), surface and volume energy loss functions, and optical conductivity. In the normal dispersion zone, optical characteristics such free charge carrier concentration, infinity dielectric constant (ε ∞), lattice dielectric constant (ε L), oscillator energy (Eo), and dispersion energy (Ed) were estimated. Furthermore, the optoelectronic nonlinear optical features and electronic transitions for the Ag-TCNQ thin film were assessed. Finally, these findings are promising milestones on the path to providing convincing evidence for the synthesis of stoichiometric thermally stable Ag-TCNQ thin film by conventional thermal evaporation technique that is potential to be utilized in optoelectronic devices applications.

O-249 METAPHOR: METabolic imaging through AI-powered Phasor-based Hyperspectral analysis and Organelle recognition for the classification of human blastocysts

Abstract Study question Can we classify human blastocysts non-invasively using hyperspectral imaging? Summary answer HS imaging can significantly enhance our classification of human embryos and reveal numerous cellular features present in the embryo invisible to brightfield imaging. What is known already Non-invasive measurement of metabolism is a safe and powerful tool to reliably predict oocyte and embryo quality. We have previously shown that our METAPHOR technology, based on HS imaging coupled to artificial intelligence, was able to separate mouse oocyte categories according to maternal age with an average AUC of 96.2% and predict blastocyst formation (AUC 82.2%). Moreover, it was able to classify mouse embryos deprived from different nutrients with an average AUC of 93.7% showing clear superiority to grading provided by experienced embryologists (51%). Study design, size, duration A total of 74 human embryos donated for research at the blastocyst stage have been imaged to date. Embryos were warmed and imaged according to our established protocol and survival was statistically indistinguishable from control embryos. Participants/materials, setting, methods Embryos are imaged using multiphoton illumination near the infra-red. The HS detection covered the simultaneous measurement of the whole visible spectrum. Embryos are then allowed to implant in our proprietary 3D ex vivo platform. Implantation is monitored up until day 9 before immunostaining is performed to quantify presence and prevalence of lineage and implantation markers. Main results and the role of chance After imaging, embryos were placed on the 3D ex vivo implantation platform and let implant. Successful implantation (75.41%) was scored by observation of the characteristic deformation of collagen fibers within the matrix and staining for relevant cell lineages (OCT4, pMLC2). Interestingly, we observed that embryos with a higher trophectoderm (TE) grading tended to implant with a higher efficiency and penetrate deeper into the matrix than embryos with lower grading. HS images have unveiled a profound cellular diversity within embryos, elucidating distinctions between the Inner Cell Mass (ICM) and TE, as well as revealing different metabolic states defined by NADH dominance, FAD dominance, protoporphyrin levels, and apoptosis. HS raw images are processed using our HS-phasor approach which allows quick computing by converting the multidimensional HS data into comprehensive visual representation of bidimensional histograms and phasor plots. In summary, our analysis pipeline encompasses the algorithms to detect and segment the embryos, the computation of histogram and phasor-plot, and the classifier. AI allows us to classify embryos in distinct spectral spaces based on their metabolic features, paving the way to the establishment of a new grading system based on HS imaging. Limitations, reasons for caution The cohort size is still limited, and ongoing experiments will increase the dataset needed for more accurate prediction of embryo implantation. The implantation platform is an in vitro test that will require future clinical validation. Wider implications of the findings The safety and speed of METAPHOR warrants its incorporation at the IVF clinic, adding an additional layer of information to the current embryo selection methods. Moreover, the non-invasive measurement of the metabolic function opens new alleys of research such as the effect of media and culture supplements on embryo culture. Trial registration number Not applicable

A green method to improve adsorption capacity of hydrochar by ball-milling: enhanced norfloxacin adsorption performance and mechanistic insight

The application of hydrochar as a cost-effective solution has received much attention for the remediation of contaminated water. An economical and environmental approach to enhancing the physicochemical and adsorption performance of hydrochar is essential. In this study, the green technology of ball-milling was firstly employed to improve the adsorption capacity of hydrochar for the typical antibiotics norfloxacin. Aqueous batch adsorption experiment using both pristine and ball milled hydrochar derived from water hyacinth, prepared by hydrothermal carbonization at three temperatures (180, 200, 220 °C) was conducted. The results showed that ball-milling decreased the specific surface area of hydrochar, but still greatly enhanced their performance on the adsorption of norfloxacin. Surface functional groups, aromatization degree, and hydrophobicity of hydrochar were increased after ball-milling, as evidenced by measurements of Boehm titration, Raman spectra, and contact angle, respectively. With these changes, all the ball-milled water hyacinth hydrochar exhibited a better performance on the adsorption of norfloxacin than pristine hydrochar. Ball-milled 220 °C water hyacinth hydrochar showed the greatest norfloxacin adsorption (68.53 mg g−1) compared to unmilled hydrochar (24.29 mg g−1), and the enhancement was effective in a wide pH range (5–9) in aqueous solutions. The thermodynamics study indicated that the norfloxacin adsorption on ball-milled hydrochar was both physically spontaneous and exothermic. Combined physicochemical characterization of hydrochar and batch experiment results suggest that the enhanced adsorption capacity was owing to boosting H-bonds, π-π electron-donor–acceptor, and hydrophobic interaction. This study suggested that ball-milling can be served as a facile, green, and cost-effective method to obtain modified hydrochar for the removal of pollutants in water.

Electric field control of the energy gap in ZnO and BaSnO3 films grown on PMN-PT

ZnO and BaSnO3 (BSO) thin films grown on Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) substrates have been studied using electrical resistance and photoconductivity (PC) spectra measurements under different applied electric fields on the substrate. The behavior of the resistance and the energy gap (EG) extracted from the PC spectra are modified by the polarization state of the substrate in the case of the ZnO film, while for BSO, these physical parameters depend on the strain imposed by the substrate when a voltage is applied on the PMN-PT. In the latter case, an in-plane tensile (compressive) strain leads to a reduction (increase) in the resistance and the energy gap when an external electric field is applied on the substrate. The behavior of ZnO and BSO can be explained by the different crystalline structure in both films and by the fact that ZnO is also a piezoelectric material. In ZnO, a change in the polarization state of the substrate is associated with an imposed strain and an induced polarization on the film that leads to a modification of the band bending and hence of the energy gap. In the case of BSO, a shift of the impurity and conduction band generates a modification of the energy gap for the different types of strain.

Research on Bioimpedance Technology Based on Real Axis Equidistant Method

Bioimpedance technology (BMI) is a non-invasive detection technology that widely applied in volume measurement, human tissue structure analysis and human body composition analysis. It uses the electrical characteristics, such as impedance, admittance and dielectric constant, and changes of biological tissues and organs to extract biomedical information about human physiological and pathological conditions. This paper analyzes the influence of the distribution of frequency points on the characteristic parameters in the measurement of bio-impedance spectrum. A new method of sampling frequency points, namely the real axis equidistant method, is proposed, and this algorithm is used in the actual test. Without changing the total number of measurement frequency points, this method can effectively improve the accuracy of feature parameter α and fc calculation by increasing the number of intermediate sampling frequency points, and improve the accuracy of human body composition estimation. At last, the impedance of human body section is measured, and the characteristic parameters of human body section bio-impedance spectrum are analyzed. The continuous bioelectrical impedance changes caused by water and sugar were observed. It was initially found that drinking water led to an increase in impedance and drinking sugar led to a decrease in impedance. It lays a theoretical foundation for further research on human body data.

High dynamic-range and portable magnetometer using ensemble nitrogen-vacancy centers in diamond.

Nitrogen vacancy (NV) centers in diamonds have been explored for a wide range of sensing applications in the last decade due to their unique quantum properties. In this work, we report a compact and portable magnetometer with an ensemble of NV centers, which we call the Quantum MagPI (Quantum Magnetometer with Proportional Integral control). Our fully integrated compact sensor assembly and control electronics fit inside a 10 × 10 × 7cm3 box and a 30 × 25 × 5cm3 rack-mountable box, respectively. We achieve a bandwidth normalized sensitivity of ∼10 nT/Hz. Using closed-loop feedback for locking to the resonance frequency, we extend the linear dynamic range to 200 μT (20× improvement compared to the intrinsic dynamic range) without compromising the sensitivity. We report a detailed performance analysis of the magnetometer through measurements of noise spectra, Allan deviation, and tracking of nT-level magnetic fields in real-time. In addition, we demonstrate the utility of such a magnetometer by real-time tracking of the movement of an elevator car and door opening events by measuring the projection of the magnetic field along one of the NV-axes under ambient temperature and humidity conditions.

SiPM and readout electronics for the JUNO-TAO Central Detector

The Taishan Antineutrino Observatory (TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). TAO consists of a spherical ton-level Gadolinium-doped Liquid Scintillator detector and its main purpose is the precise measurement of the reactor antineutrino spectrum by detection of light produced in v̅e + p⟶ e + + n reaction, as a reference for JUNO. About 4,500 photoelectrons per MeV could be detected by instrumenting the sphere surface (∼10 m2) with state-of-the-art Silicon PhotoMultipliers (SiPMs), resulting in a sub-percent energy resolution. In this work we present the implemented architecture of the readout electronics based on low-noise, high-speed Front-End Boards (FEBs) connected to a 50×50 mm2 SiPM Hamamatsu tile, composed by 32 SiPM elements of 12×6 mm2 each, divided into two independent output channels. The overall 4,024 FEBs will be supplied through eight custom flanges that have to bring in about 1.5 kW. On the same flanges the 8,048 output signal cables are distributed and routed to the Front-End Controllers (FECs), based on Virtex Ultrascale FPGAs, able to manage up to eight 16-channel ADCs, for a total of 128 channels on a single FEC, with a maximum sampling rate of 250 MHz with 12-bit resolution. A dedicated trigger and data-acquisition system will filter and record occurring events, rejecting dark count events. We report the results of the characterization for the pre-production FEBs batch, following the main figures of merit defined for the experiment, showing single photoelectron resolution better than 13% and dynamic range up to 250 photoelectrons.

Feature Engineering for Physics-informed Evaluation of Electromechanical Impedance Measurements for Sandwich Face Layer Debonding Identification

The present research exploits various physically explainable features for the evaluation of electromechanical impedance (EMI) measurements for sandwich face layer debonding identification using a recently published two-step physics- and machine-learning (ML)-based approach. In the previous work, the ML approach used employs a One-Class Support Vector Machine and a K-Nearest Neighbor model for debonding detection and size estimation, respectively. Feature engineering was used to compensate for the simplifications of the finite element (FE)-based physical model and a simple data calibration step was used to adapt to distribution shifts. This enabled to train both ML models exclusively with FE simulation-based synthetic EMI spectra data. The efficacy of the method was demonstrated on real-world EMI spectra measurements of a circular aluminum sandwich panel by a piezoelectric transducer. The considered face layer debonding damage was idealized and stepwise increased by a milling process. In the present work, we explore opportunities for further optimization of our method with respect to data distillation, where we reduce the computational requirements of both training and inference while at the same time preserving essential information. Furthermore, we investigate the usefulness of a separate approach for debonding detection, formulated as an anomaly detection problem. The data preprocessing and ML models are validated by unseen real-world EMI measurement data and benchmarked with the previously published damage evaluation results, considering both reliability and accuracy. The data and the code used in this study are provided in their entirety to enable reproducibility, enhance comprehensibility, and encourage future research.

Experimental study on the discharge characteristics of an air rotating gliding arc

In this study, the discharge characteristics of an air rotating gliding arc (RGA) are investigated by synchronous measurements of a digital oscilloscope and a high-speed camera, and the emission spectrum measurement. The discharge evolution in one complete motion cycle exhibits a ‘breakdown-elongation-extinction’ process accompanied by a jump phenomenon of the arc root and a back-breakdown phenomenon. The discharge evolves from the unstable breakdown mode (U-B), to the transition mode and finally to the stable gliding mode (S-G) by increasing the input voltage or decreasing the tangential and axial gas flow rates. The U-B mode at an input voltage of 120 V is featured by the large reduced electric field and high electron temperature of 1.90 eV, but the arc length and existence time are very short. The S-G mode at an input voltage of 270 V has a relatively low breakdown frequency of 0.33 kHz and an average breakdown current of 1.31 A, implying that the arc steadily glides and rotates along the spiral electrode. The average electron temperature is 0.64 eV in the S-G mode, while the arc length and existence time are longer. The rotational and vibrational temperatures of the N2(C3∏u) state are respectively measured at 2200 K and 4400 K in the U-B mode, and in the S-G mode are 2600 K and 4820 K. From the evolution of emission intensities of measured excited species, it is found that the NOγ band emission intensity generally rises from the U-B mode to the S-G mode since the gas temperature and arc existence time rise, indicating that the S-G mode may be beneficial for the vibrationally promoted Zeldovich reactions. This study could deepen the understanding of arc characteristics in air RGA for selecting a suitable mode to achieve better plasma performance in practical applications.

Electrochemical applications of CdO-Co-ZnO nanocomposites, their synthesis and characterization reveal their multifunctional abilities

In this study, we investigated the electrochemical catalysis potential of hybrid nanocomposites containing CdO, Co and ZnO nanocomposites, as opposed to Zn-O doped Co nanocomposites, have weaker Coulomb interactions due their ionic bonds. Because CdO and Co form a covalent bond, Co interacts more strongly with O than Zn. In order to reduce nanoparticle crystallinity, oxygen defects improve the interaction between −O and oxygen defects in the lattice. From SEM micrographs, it appears that CdO does not completely change under the influence of dopants. It can be seen from the SEM image that both materials have very tightly packed particles. The Co and CdO dopants in ZnO nanocomposites prevent them from absorbing a large range of visible wavelengths. It is more energy-dense for nanocomposites with 5.28 eV to compare to 5.14 eV nanocomposites. The fact that CdO matrix has a tuneable bandgap is evident since different types of dopants are used in its manufacture. There are at least three distinct absorption modes in Co nanocomposites doped with CdO, around 450, 498, and 676 cm−1. In addition to its absorption from 450 cm−1 and 498 cm−1 vibrational modes, Co-O stretching absorption along the [101] plane has also been observed at 676 cm−1. As a method of studying charge carriers, photoluminescence spectroscopy is usually used. This method can be used to analyze electron-hole pairs (e−/h+) formed by semiconducting particles. It is in the blue emission range between the luminescence band of 615 nm and the valence band of 635 nm. With increasing cobalt and zinc concentrations, CdO nanomaterials lose their remanent magnetization. CdO has been demonstrated to have significant coercive effects in both pure and additively incorporated solutions regardless of their anisotropic, morphological, porosity, and particle size distribution. Electrochemical impedance spectrum measurements were conducted between 100 kHz and 0.01 Hz. According to the Nyquist plot, purity CdO, CdO doped Co, and CdO doped ZnO nanocomposites show a high frequency resistance to charge transfer. Nanocomposites that contained CdO doped Co & ZnO were exposed to UV light for 120 min to remove the solution. The degradation of MO is virtually nonexistent when no photocatalyst is present, but with a photocatalyst, degradation can reach 92.56 %.

Effect of Gamma Irradiation (Cesium-137) on the Properties of Chemical Functional Groups from Collagen Extraction of Snakehead Fish Scales (Channa striata)

This study aims to determine the absorption spectrum of the functional groups of snakehead fish scale collagen before irradiation and the effect of the dose of Cesium-137 irradiation on the functional groups in snakehead fish scale collagen. The extraction method used is acid extraction. Measurement of the absorption spectrum of collagen samples from snakehead fish scales using an FTIR spectrophotometer. Samples were irradiated using doses of 10 mGy, 30 mGy and 50 mGy. The results of the functional group values before irradiation produce amide A, amide I, amide II and amide III which fill the absorption area of the functional group. The results of the functional group values produced after irradiation for a dose of 10 mGy produced amide I, amide II and amide III which filled the absorption area. Amide A and amide B do not fill the absorption region at a dose of 10 mGy. Doses of 30 mGy and 50 mGy produced amide A, amide I, amide II and amide III which filled the absorption area. Amide B did not fill the absorption area at doses of 30 mGy and 50 mGy. Amide groups that are not detected or do not meet standard collagen functional group standards can be caused by the chemical composition of the fish scale extraction process.

Evaluación de Interferencias en Escenarios Urbanos Interiores en Bandas Inferiores a 6 GHz

In an increasingly interconnected world, the unlicensed 2.4 and 5 GHz frequency bands have been essential for developing wireless applications such as Wi-Fi (IoT devices), home automation, and media streaming, among others. However, in highly populated urban environments, such as Guayaquil,Ecuador, the efficient administration of these spectrum swaths is a critical challenge that allows the development of smart and sustainable cities. The lack of comprehensive studies on interference in these bands in dense indoor environments causes a deterioration in network reliability, limiting the ability to use higher modulation schemes (MCS) which are essential for applications that require higher connection speeds. This study focuses on the precise collection of radio spectrum measurements in Guayaquil, specifically in the 2.4 and 5 GHz bands, to evaluate interference levels and channel availability in these densely urban environments. The results reveal more pronounced saturation in the 2.4 GHz band, underscoring the urgent need for more effective spectrum management in densely populated urban areas to ensure robust connectivity.

Antenna Design for Absolute Sky Measurements at Gigahertz Frequencies—a First Step toward Detecting CMB Spectral Distortions from Recombination

There exist inevitable deviations in the cosmic microwave background spectrum from that of a blackbody. The additive distortions from photons emitted over the epoch of recombination are one such deviation. We present a novel scalable broadband antenna design motivated by detecting these spectral distortions in the 2.5–4 GHz band. This antenna is capable of maintaining the spectral quality of the measured sky spectrum to 1 part in 103 over the full band and outperforms conventional broadband antennas by at least an order of magnitude. While this is not sufficient to make a direct detection of the cosmological recombination radiation, it meets the baseline design criteria for an experiment that can make an absolute measurement of the sky spectrum at the millikelvin level, thereby making it capable of improving foreground models to global signal detection experiments (including those from cosmic dawn and the epoch of reionization) and addressing the problem of the excess radio background at 3.3 GHz reported by the ARCADE2 experiment.

Search for Dark Matter Ionization on the Night Side of Jupiter with Cassini.

We present a new search for dark matter (DM) using planetary atmospheres. We point out that annihilating DM in planets can produce ionizing radiation, which can lead to excess production of ionospheric H_{3}^{+}. We apply this search strategy to the night side of Jupiter near the equator. The night side has zero solar irradiation, and low latitudes are sufficiently far from ionizing auroras, leading to a low-background search. We use Cassini data on ionospheric H_{3}^{+} emission collected three hours either side of Jovian midnight, during its flyby in 2000, and set novel constraints on the DM-nucleon scattering cross section down to about 10^{-38} cm^{2}. We also highlight that DM atmospheric ionization may be detected in Jovian exoplanets using future high-precision measurements of planetary spectra.

Quantitative Complex Refractive Index Changes in Thin Films: A Pump-Probe Spectroscopy Analysis Approach.

Photoexcitation induces intricate changes in both the real and imaginary components of the complex refractive index of thin film materials, which is essential for interpreting transient spectral features. Here, we employ a Kramers-Kronig-based analytical approach to elucidate light-induced changes in the complex refractive index from transient transmission spectra of thin films. Using gold-perovskite films as model systems, we conduct experimental measurements of transient transmission spectra for both individual gold and perovskite films, as well as for the bilayer heterostructure. Our analysis reveals significant changes in the refractive index and absorption for these systems. Notably, we observe negligible photocarrier transfer between the gold and perovskite layers based on transient spectroscopic analysis. These findings have implications for the design and optimization of bilayer heterostructures in optoelectronic applications. This work highlights the importance of spectroscopic techniques in studying the photophysical properties of heterostructure films.

Study of Electrochromic Properties of PEDOT:PSS for Tunable Filter Optics with Lithium Salt Electrolyte

Nowadays, conductive polymers based on poly(3,4-ethylenedioxythiophene), poly(styrene sulfonic acid), or PEDOT:PSS, have been employed as a flexible and transparent coating in various significant electronic applications. With the demand for electrochromic properties, such as in electronic displays, further research into its electrooptic properties is required, especially the systematic understanding to obtain the optimized switching. Our research investigates the electrooptic properties of the PEDOT:PSS film, particularly the refractive index changing under various applied biases. The electrochromic device is prepared in a simple fashion, and the electroactive layer of PEDOT:PSS thickness is defined via spin-coating between two indium tin oxide (ITO) substrates. To increase the switching properties of PEDOT:PSS, lithium perchlorate (LiClO4) was prepared in acetonitrile, as the electrolyte in varied concentrations of 1.195 M, 1.5 M, and 2.0 M, respectively. A potential voltage of -4.0 V to 0.0 V is utilized to study the device's electrochromic properties with the step 5 mV/s continuously. Finally, the optical properties are characterized using the spectroscopy method based on real-time measurement of the transmission spectrum and transmission matrix calculations. The change in visible light absorption, transmission, and film color is recorded under a switching cycle that shows consistent behavior. This allows the further utilization of such a hybrid structure for possible tunable filter applications. Keywords: Electrochromic, PEDOT:PSS, Optical, Lithium salt, Electrolyte

Hyperfine interactions of paramagnetic radiation-induced defect centres in advanced ceramic breeder pebbles

Advanced ceramic breeder (ACB) pebbles consisting of 65 mol% lithium orthosilicate (Li4SiO4) and 35 mol% lithium metatitanate (Li2TiO3) are developed for tritium breeding in the European Union’s (EU) helium cooled pebble bed (HCPB) breeder blanket concept of the demonstration fusion power plant (DEMO). Electron-nuclear double resonance (ENDOR) spectroscopy is a powerful and widely used magnetic resonance technique that combines aspects of electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR). In the present work, ENDOR spectroscopy was applied to investigate hyperfine (HF) interactions of paramagnetic radiation-induced defect centres (containing unpaired electrons) in the biphasic ACB pebbles after irradiation with 10 MeV accelerated electrons. To separate individual EPR signals of the formed and accumulated paramagnetic centres, isochronal annealing of the irradiated ACB pebbles followed by EPR spectra measurements at X- and Q-microwave frequency bands at room and low temperature were performed. Afterwards, X-band ENDOR spectra at low temperature were recorded for selected EPR signals to reveal HF interactions between the unpaired electron spins with the spins of magnetic 7Li and 1H isotope nuclei. The g-factor and HF coupling values determined from EPR and ENDOR spectra simulations provide novel insights into the local structure of paramagnetic hole- and electron-type centres in the irradiated ACB pebbles.