Calvo-de la Rosa, Jaume, Alexandre Locquet, Denis Bouscaud, Sophie Berveiller, and D. S. Citrin. "Optical constants of CuO and ZnO particles in the terahertz frequency range." Ceramics International (2020).
Monday, 6 July 2020
Friday, 3 July 2020
Terahertz Time-of-Flight Tomography Beyond the Axial Resolution Limit: Autoregressive Spectral Estimation Based on the Modified Covariance Method
Zhai, Min, Alexandre Locquet, Cyrielle Roquelet, and D. S. Citrin. "Terahertz Time-of-Flight Tomography Beyond the Axial Resolution Limit: Autoregressive Spectral Estimation Based on the Modified Covariance Method." Journal of Infrared, Millimeter, and Terahertz Waves (2020): 1-14.
We present a time-of-flight tomography method for exceeding the naïve axial (i.e., depth) resolution limit of terahertz (THz) deconvolution by autoregressive spectral extrapolation (AR) based on the modified covariance method (AR/MCM). In contrast to Wiener filtering combined with wavelet denoising, AR/MCM does not discard any frequency components in the low signal-to-noise (SNR) regions of the measured data, and unlike the AR approach based on the Burg method (AR/BM), no peak splitting (single peaks in the impulse response function appearing as double peaks) as well as frequency bias (spectral peaks shifted with respect to their correct positions) is observed after deconvolution. After verifying the advantages of AR/MCM over Wiener filtering in conjunction with wavelet denoising as well as over AR/BM, using synthetic data, AR/MCM is employed to reconstruct a single layer of mill scale on a steel coupon from experimental THz time-of-flight tomography data. The reconstruction shows good agreement with the film thickness obtained from destructive cross-sectional measurements. In addition, unlike AR/BM, optimizing the parameters to obtain stable reconstruction is straightforward relying of Akaike’s information criterion suggesting that AR/MCM can be an easier to implement for THz nondestructive characterization of stratigraphy under noisy conditions, particularly when estimates of the stratigraphy may not a priori be available.
Full paper can be found at https://link.springer.com/article/10.1007/s10762-020-00722-1
… that minimizes the AIC. Experiment. The measurement in this work is carried out using a pulsed, broadband THz time domain system from TeraView Ltd. (TPSSpectra 3000), shown schematically in Fig. 1. The GaAs photoconductive …
Thursday, 2 July 2020
High performance of talented copper/magneso-zinc titanate nanostructures as biocidal agents for inactivation of pathogens during wastewater disinfection
Nahrawy, Amany M. El, Ahmed M. Bakr, Ali B. Abou Hammad, and Bahaa A. Hemdan. "High performance of talented copper/magneso-zinc titanate nanostructures as biocidal agents for inactivation of pathogens during wastewater disinfection." Applied Nanoscience: 1-17.
In the present research, the performance of MZT nano-titanate was established by combining (0.3–0.5) copper nanoparticles (0–0.5C-MZT) to improve the antimicrobial efficacy of promising engineered nanomaterials. XRD characterized the phase purity confirms the formation of magneto-zinc and copper titanates at 750 °C. The morphological features of four engineering nanoceramics were accurately described. As well, the inactivation effects of microbial growth were also evaluated for these kinds of engineered nanomaterials. After that, the disinfection of estimating four harmful waterborne bacteria in real wastewater was appraised. The results obtained of Raman active modes and FT-IR exhibit that the crystallization was strengthened by Cu doping. The natural THz response of the samples appears a distinct attenuation in the THz transmission. In addition, the results showed that 0.5C-MZT is a powerful antimicrobial agent for damaging the targeted pathogens. The results of toxicological safety tests indicated that the nanomaterials examined are safe for environmental applications. The results achieved reveal that the examined proficient dosage (200 mg/L) of studied 0.5C-MZT nanomaterials was practiced to deactivate four predominant waterborne pathogens in wastewater. Eventually, MZT could serve as a smart nano-weapon towards numerous sorts of dangerous pathogenic microbes and results; therefore, recommend that MZT can be employed as a talented disinfecting agent within wastewater processing.
for full paper see https://link.springer.com/article/10.1007%2Fs13204-020-01454-3
… Standard transmission THz/TDS coordination is occupied for measurements using the TPS spectra 3000 system (Teraview Ltd. England) model by using the transmission unit of polyethylene pelts and under Nitrogen gas (N2) purging …
Wednesday, 1 July 2020
Utilizing multilayer structures to enhance terahertz characterization of thin films ranging from aqueous solutions to histology slides
Sun, Qiushuo, Kai Liu, Xuequan Chen, Xudong Liu, A. I. Hernandez-Serrano, and Emma Pickwell-MacPherson. "Utilizing multilayer structures to enhance terahertz characterization of thin films ranging from aqueous solutions to histology slides." Optics letters 44, no. 9 (2019): 2149-2152.
Tuesday, 30 June 2020
The OSA has awarded the William F. Meggers Award for recognition of his outstanding work in spectroscopy to Tony F. Heinz
Stanford University and SLAC National Accelerator Laboratory, USA
For seminal studies of the properties and dynamics of surfaces, interfaces, and nanoscale materials by diverse spectroscopic techniques, including through the development of powerful new methods .
Tony Heinz received a B.S. in physics from Stanford University, USA, and a Ph.D. in physics from the University of California, Berkeley, USA. He is a professor of applied physics and photon science at Stanford University and the Associate Laboratory Director for Energy Sciences at SLAC National Accelerator Laboratory. Previously, he was a research staff member at the IBM Watson Research Center, USA, and a professor of physics and electrical engineering at Columbia University, USA. He is a Fellow of OSA and served as OSA President in 2012. Heinz has developed a wide range of spectroscopic techniques to examine the properties and dynamics of nanoscale systems. These methods include interface sensitive nonlinear spectroscopy and time-resolved approaches, such as terahertz time-domain techniques. The measurement techniques have been applied to elucidate the electronic, optical and chemical properties of 0-, 1-, and 2-dimensional materials and interfaces. The research would not have been possible without the insight and hard work of more than 70 graduate students and postdocs over the years.