Article
Optics
Shaonan Zheng, Hong Cai, Linfang Xu, Nanxi Li, Zhonghua Gu, Yao Zhang, Weiguo Chen, Yanyan Zhou, Qingxin Zhang, Lennon Yao Ting Lee
Summary: This article introduces a chip-scale silicon substrate-integrated hollow waveguide (Si-iHWG) for optical gas sensing, which provides a compact, versatile, robust, and cost-effective sensing solution.
PHOTONICS RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
Snigdha Khuntia, Manish Kumar Sinha, Parveen Dalal, Arunima Singh
Summary: The combination of ozone and UV irradiation in aqueous mode has been investigated for removing SO2 and NOX. Various combinations of ozone, flue gas, and UV irradiation power were attempted to achieve complete removal of flue gases. The amount of hydroxyl radicals generated by UV and O3 combination was measured. A comprehensive comparison of the contribution of oxidants such as ozone, UV, and hydroxyl radicals was depicted. To reduce power consumption, it is important to find a suitable route, which has been achieved by changing the operation mode of gases, resulting in over 95% NOX and almost 100% SO2 removal.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Physics, Multidisciplinary
Yonglong Jin, Yaoyao Yin, Danzhu Wei, Tian Xu, Chaonan Wang, Meifeng Xu, Cong Peng
Summary: A liquid-core metal-cladding waveguide (LCMW) structure was proposed for optical trapping of SiO2 colloid particles, and factors such as the reflectivity of the guiding layer, light-off time, and sample refractive index were found to influence the time required for the SiO2 particles to reach a stable state during self-assembly.
Article
Engineering, Electrical & Electronic
Chuantao Zheng, Mingquan Pi, Fang Song, Yafei Li, Zihang Peng, Gangyun Guan, Lei Zhang, Yanming Ma, Yuting Min, Weilin Ye, Yiding Wang
Summary: Infrared absorption spectroscopy (IAS) is a powerful tool for gas sensing, with advantages of high sensitivity, good selectivity and in-situ measurement. Different types of infrared gas sensors, including discrete optics, hollow-core fiber sensors, and on-chip sensors, have been developed for various application environments. While discrete and hollow-core fiber sensors offer higher sensitivity due to their large light-gas interaction length, on-chip sensors with miniaturized size and low power consumption have limitations in interaction effect. However, advanced sensing techniques like slow-light enhanced absorption spectroscopy and surface-enhanced infrared absorption spectroscopy have been proposed to improve the performance of on-chip sensors.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
James D. Gaynor, Ashley P. Fidler, Yen-Cheng Lin, Hung-Tzu Chang, Michael Zuerch, Daniel M. Neumark, Stephen R. Leone
Summary: Nonlinear wave mixing in solids with ultrafast X-rays, particularly tabletop-based attosecond noncollinear four-wave mixing spectroscopy, has been demonstrated to provide valuable insights into the electronic dynamics of materials, such as the characterization of core-excitons and their properties in NaCl. This investigation highlights the potential of tabletop attosecond FWM spectroscopies as a viable technique for time-resolved solid state measurements.
Article
Engineering, Environmental
Tu Pham Le, Pakorn Opaprakasit
Summary: The study developed a halogen-free process using ozone as an environmentally-friendly alternative for the generation of TEMPO+. Quantitative monitoring of the reaction was achieved through iodine titration combined with UV-Vis spectroscopy, indicating a conversion rate of TEMPO reaching 70% under optimized conditions. The results suggest that ozone has high selectivity towards TEMPO oxidation to form TEMPO+ over disproportionation in acid solutions, making it a promising method for selective oxidation of primary alcohols.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Analytical
Zhangxiong Chen, Jiafu Zeng, Menghui Zhu, Xiaosong Zhu, Yiwei Shi
Summary: We have demonstrated a mid-infrared gas sensor based on a hollow waveguide cell. The waveguide inner-coated with silver and silver iodide films achieves low loss at 4.26 μm wavelength. The sensor uses a broad-spectrum light source and a pyroelectric detector, and the waveguide cell is butt-coupled with them. Various lengths and inner diameters of waveguide cells have been tested and optimized, with a coiled waveguide cell achieving a low detection limit of 263 ppb. This provides a simple, miniaturized, and cost-effective solution for trace gas sensing.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Optics
Ai Hosoki, Michiko Nishiyama, Kazuhiro Watanabe, Nozomu Sakurai
Summary: This study experimentally demonstrated the effects of using polarization-maintaining fibers (PMFs) as a sensing region in surface plasmon resonance (SPR) sensors. The results showed that PMF sensors exhibit broader SPR spectra and higher sensitivity compared to conventional single-mode fiber (SMF) sensors.
Article
Optics
Weijiang Xu, Yi Liu, Jinke Bai, Yan Li, Shiliang Qu
Summary: This Letter proposes an ultracompact fiber inclinometer based on a bubble controlled by Marangoni force. By coupling a 980-nm laser, the bubble can suspend in a quantum dots (QDs) liquid-core waveguide (LCW) due to the Marangoni effect. Under the excitation of a 405-nm laser, QDs LCW exhibit green emissions centered at 523 nm. The experimental results show that the sensitivity based on the peak intensity ratio (PIR) reaches 0.22/degrees with a linearity of 0.979 from 0 degrees to 35 degrees. Furthermore, the sensor has excellent stability and repeatability.
Article
Optics
Grzegorz Gomolka, Grzegorz Stepniewski, Dariusz Pysz, Ryszard Buczynski, Mariusz Klimczak, Michal Nikodem
Summary: This paper presents a highly-sensitive hollow-core fiber based methane sensor using a mid-infrared distributed feedback interband cascade laser. The sensor uses an all-silica negative curvature hollow-core fiber as the gas cell, achieving a low detection limit of 1.54 ppbv. The sensor was successfully applied for continuous monitoring of ambient methane and water vapor in atmospheric air, demonstrating its usability in environmental monitoring.
Article
Environmental Sciences
Venkatraman Madurai Ramakrishnan, G. Rajesh, P. Selvakumar, M. Flores, N. Muthukumarasamy, Dhayalan Velauthapillai, Nguyen Thuy Lan Chi, Arivalagan Pugazhendhi
Summary: In this study, TiO2 nanoparticles were prepared by solvothermal method, and Ag nanoparticles were decorated over TiO2 surface through photodeposition method. The results showed that the Ag-decorated TiO2 exhibited improved light absorption performance and SPR effect, and it was successfully used as the photoanode in dye-sensitized solar cells.
Article
Chemistry, Analytical
Diandra Nunes Barreto, Gabriel Martins, Peter C. Hauser, Boris Mizaikoff, Joao Flavio da Silveira Petruci
Summary: In this study, a reagent-less approach was proposed for rapid and accurate determination of sulfite threshold levels by measuring the absorbance of gaseous SO2 directly after sample acidification. The method enabled the determination of sulfite in beverages with suitable linearity and analysis time. The method was also successfully applied for sulfite quantification in concentrated grape juice, coconut water, and beer, showing promising potential for in-situ studies on sulfite and other volatilized preservatives.
ANALYTICA CHIMICA ACTA
(2022)
Article
Chemistry, Analytical
Iris Groeneveld, Suzan E. Schoemaker, Govert W. Somsen, Freek Ariese, Maarten R. van Bommel
Summary: The article discusses how many organic compounds undergo changes under the influence of light, which can have both beneficial and detrimental effects. To study light-induced degradation, a low-volume exposure cell was used, and successful monitoring of dye degradation was achieved.
Article
Chemistry, Analytical
Ran Bi, Mingquan Pi, Chuantao Zheng, Huan Zhao, Lei Liang, Fang Song, Dingdi Wang, Yu Zhang, Yiding Wang, Frank K. Tittel
Summary: The advantages of integrating infrared waveguide gas sensors on a chip include compactness, low power consumption, and high selectivity. In this study, a rectangular waveguide gas sensor using niobium pentoxide as the core layer was fabricated, achieving methane measurement.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Applied
Diego Tamburini, Chika Mori Shimada, Blythe McCarthy
Summary: This study analyzed 61 wool fabric samples from the appendix of a dyeing manual published in England in 1893. High performance liquid chromatography was used for molecular characterization. The results showed discrepancies between the dyes described in the manual and the actual dyes used in the samples, with mixtures of different categories of dyes often being used.