Article
Biochemistry & Molecular Biology
Tatiana Tozar, Mihai Boni, Angela Staicu, Mihail Lucian Pascu
Summary: This study demonstrates the efficient photodegradation of ciprofloxacin using 266 nm laser beams, with analysis conducted through UV-Vis and FTIR spectroscopy, pH assay, and laser-induced fluorescence. HPTLC densitometry was utilized for characterizing fluorescence and fluorescence lifetime of photodegradation products. The results provide valuable insights into the degradation process and the identification of photoproducts.
Article
Multidisciplinary Sciences
Maria Giulia Delli Santi, Giacomo Insero, Saverio Bartalini, Pablo Cancio, Federico Carcione, Iacopo Galli, Giovanni Giusfredi, Davide Mazzotti, Antonio Bulgheroni, Ana Isabel Martinez Ferri, Rafael Alvarez-Sarandes, Laura Aldave de las Heras, Vincenzo Rondinella, Paolo De Natale
Summary: The precise determination of radionuclide inventory in radioactive waste streams is crucial for nuclear waste management. This paper demonstrates the use of laser-based saturated-absorption cavity ring-down (SCAR) spectroscopic technique as an accurate alternative for C-14 content determination in nuclear waste. The results show consistent measurements compared to accelerator mass spectrometry (AMS), indicating the maturity and accuracy of SCAR for C-14 analysis in concrete and graphite samples.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Multidisciplinary
Stefania Castelletto, Jovan Maksimovic, Tomas Katkus, Takeshi Ohshima, Brett C. Johnson, Saulius Juodkazis
Summary: By using femtosecond laser writing in silicon carbide and gallium nitride, vacancy-related color centers that emit photoluminescence from visible to infrared light can be generated. Large arrays of silicon vacancy defects with high localization within the confocal diffraction limit and minimal material damage can be produced using a 515 nm wavelength 230 fs pulsed laser. This study demonstrates the power-law scaling of the number of color centers formed with laser fabrication energy, indicating that the color centers are created by photoinduced ionization.
Article
Multidisciplinary Sciences
Driss Lahlou Kitane, Salma Loukman, Nabila Marchoudi, Alvaro Fernandez-Galiana, Fatima Zahra El Ansari, Farah Jouali, Jamal Badir, Jean-Luc Gala, Dimitris Bertsimas, Nawfal Azami, Omar Lakbita, Omar Moudam, Rachid Benhida, Jamal Fekkak
Summary: This paper presents a rapid, reagent-free screening method for detecting SARS-CoV-2, achieving high accuracy and reducing testing time to minutes. It is suitable for use in laboratories with limited resources.
SCIENTIFIC REPORTS
(2021)
Article
Optics
Hu Ge, Weipin Kong, Rui Wang, Gang Zhao, Weiguang Ma, Weigen Chen, Fu Wan
Summary: We present a new and simple technique to lock a 642 nm diode laser to an external linear power buildup cavity for enhancement of gas Raman signals. Compared to traditional techniques, this method guarantees stable power buildup without additional optical elements or complex arrangements. Detection limits at the ppm level are achieved for ambient gases (N2, O2) using a 40 mW diode laser and a backward Raman light collection geometry with an exposure time of 60 s.
Article
Chemistry, Analytical
Uri Zamir, Maayan Cohen, Avi Lerer, Yehoshua Kalisky, Amir Kaplan, Igor Rahinov, Joshua H. Baraban
Summary: We have successfully extended Intracavity Laser Absorption Spectroscopy to the ultraviolet region, thanks to a Ce-doped gain medium. This technique has been proven to be effective for measuring important species in combustion and atmospheric chemistry, including formaldehyde, sulfur dioxide, and hydroxyl radical.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Engineering, Multidisciplinary
Makoto Matsui, Ryuji Kobayashi, Tomoya Yasui
Summary: This study investigated the upper limit of sensitivity enhancement in a multipass process. It was found that by adjusting the mirror diameter, the sensitivity could be enhanced by several orders of magnitude. However, the experimental results were slightly lower than the numerical predictions, possibly due to the limitations of alignment optics.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
K. Saran Kumar, Y. Esther Blesso Vidhya, Ramya Selvaraj, Satyanarayanan Seshadri, S. M. Shiva Nagendra, Nilesh J. Vasa
Summary: This article presents a dual-wavelength band broadband photoacoustic spectroscopy (BPAS) technique ideally suited to low-energy broadband sources for industrial and environmental multigas sensing applications. The proposed technique allows for comprehensive concentration measurement and eliminates the impact of cross sensitivity among gases. The MDL achieved for methane, ammonia, and carbon monoxide were 0.4 and 0.7 ppm, 0.3 and 1.8 ppm, and 2.6 ppm, respectively.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
K. Saran Kumar, Y. Esther Blesso Vidhya, Ramya Selvaraj, Satyanarayanan Seshadri, S. M. Shiva Nagendra, Nilesh J. Vasa
Summary: This article presents a dual-wavelength band broadband photoacoustic spectroscopy (BPAS) technique for low-energy broadband sources in multigas sensing applications. The technique uses a broad spectral range to cover a wide range of absorption bands of different gases and eliminates the interference between gases. The sensor shows comprehensive concentration measurement and achieves a minimum detection limit for various gases.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Yaopeng Cheng, Fupeng Wang, Jinghua Wu, Rui Liang, Qiang Wang, Yubin Wei, Jiachen Sun, Qian Li, Qingsheng Xue
Summary: Fixed wavelength modulation spectroscopy (FWMS) modulates the wavelength around a constant value, which differs from the dynamic scanning ramp used in standard wavelength modulation spectroscopy (WMS). In this study, a software-based proportional-integral-derivative (PID) controller is developed to lock the laser wavelength at a specific methane line for CH4 detection in the FWMS system. The optimized PID parameters lead to a laser wavelength locking performance with a 1 sigma fluctuation of less than 406 kHz and a 100% locking success rate, which is the best reported result so far. The FWMS CH4 sensor shows improved linearity, with a detection sensitivity of 52 ppb at 0.1 s and the potential for further improvement with extended integration time.
IEEE SENSORS JOURNAL
(2023)
Article
Chemistry, Physical
E. P. Kovalev, A. S. Shalygin, S. A. Prikhod'ko, N. Yu Adonin, O. N. Martyanov
Summary: In this study, the absorption of acetylene by ionic liquids (ILs) was investigated using in situ ATR-FTIR spectroscopy. The analysis revealed a correlation between the spectral changes of absorbed acetylene and the nature of ILs.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Electrical & Electronic
Haruna Okada, Scott T. Sanders
Summary: The study examined the performance of IR and Raman spectroscopy in estimating the composition and properties of liquid mixtures, finding that Raman outperformed gas-phase IR and combined spectroscopy was even more effective. The performance of different absorption ranges in IR spectroscopy was also evaluated, with some ranges performing better than others for estimating molecular properties. Gas-phase IR showed better performance compared to liquid-phase IR when using the full range of absorption.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Analytical
Laura Kronlachner, Johannes Frank, Erwin Rosenberg, Andreas Limbeck
Summary: Polymeric composite materials are increasingly important due to their versatility and adaptability. Current analysis methods cannot provide the necessary information on both organic and elemental constituents. This study presents a novel approach using laser ablation and concurrent measurements with EI-MS and ICP-OES to directly characterize the main components of solid polymer samples.
ANALYTICA CHIMICA ACTA
(2023)
Article
Materials Science, Multidisciplinary
Oleg A. Morozov, Stella L. Korableva, Larisa A. Nurtdinova, Vladimir M. Kyashkin, Pavel A. Popov, Alexander E. Klimovitskii, Maksim S. Pudovkin, Vadim V. Semashko
Summary: The opportunity to grow LiGdF4 single crystals with length of several centimeters using the Bridgman-Stockbarger technique was demonstrated. Optically perfect LiGdF4 crystals measuring 8 mm and 55 mm in length were successfully grown. The phase composition, thermal conductivity, basic optical and spectral-kinetic properties of LiGdF4 crystals were studied for the first time. The results showed that LiGdF4 crystal has a larger linear thermal expansion coefficient and a more pronounced thermal conductivity dependence compared to other crystals.
Article
Physics, Applied
S. Chin, V. Mitev, E. Giraud, R. Maulini, S. Blaser, D. L. Boiko
Summary: This study introduces a method for producing fast frequency-swept laser emission from a monolithic mid-infrared laser and demonstrates its feasibility through experiments.
APPLIED PHYSICS LETTERS
(2021)
