Intense Pulsed Light-Treated Near-Field Electrospun Nanofiber on a Quartz Tuning Fork for Multimodal Gas Sensors

2020 ◽  
Vol 12 (21) ◽  
pp. 24308-24318 ◽  
Author(s):  
Danny Wong ◽  
Osama Abuzalat ◽  
Juhee Ko ◽  
Jungchul Lee ◽  
Seonghwan Kim ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Tuning Fork ◽  
Near Field ◽  
Quartz Tuning Fork ◽  
Intense Pulsed Light ◽  
Electrospun Nanofiber ◽  
Pulsed Light

First Overtone Frequency Stimulated Quartz Tuning Fork Used for Shear-Force Scanning Near-Field Optical Microscopy

2003 ◽  
Vol 20 (11) ◽  
pp. 1928-1931 ◽  
Author(s):  
Liu Sheng ◽  
Sun Jia-Lin ◽  
Sun Hong-San ◽  
Tan Xiao-Jing ◽  
Shi Shuo ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Shear Force ◽  
Tuning Fork ◽  
Near Field ◽  
Quartz Tuning Fork

Distance control for a near-field scanning microwave microscope in liquid using a quartz tuning fork

2005 ◽  
Vol 86 (15) ◽  
pp. 153506 ◽  
Author(s):  
Songhui Kim ◽  
Hyunjun Yoo ◽  
Kiejin Lee ◽  
Barry Friedman ◽  
Mariafrancis A. Gaspar ◽  
...  
Keyword(s):  
Tuning Fork ◽  
Near Field ◽  
Quartz Tuning Fork ◽  
Distance Control ◽  
Microwave Microscope ◽  
Near Field Scanning

scholarly journals Passive Electrical Damping of a Quartz Tuning Fork as a Path to Fast Resonance Tracking in QEPAS

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5056
Author(s):  
Roman Rousseau ◽  
Diba Ayache ◽  
Wioletta Trzpil ◽  
Michael Bahriz ◽  
Aurore Vicet
Keyword(s):  
Gas Sensors ◽  
Electronic Circuit ◽  
Tuning Fork ◽  
Relaxation Times ◽  
Quartz Tuning Fork ◽  
High Quality ◽  
Spice Simulation ◽  
Signal Drift ◽  
Environmental Variations ◽  
Electrical Damping

In Quartz-Enhanced PhotoAcoustic Spectroscopy (QEPAS) gas sensors, the acoustic wave is detected by the piezoelectric Quartz Tuning Fork (QTF). Due to its high-quality factor, the QTF can detect very low-pressure variations, but its resonance can also be affected by the environmental variations (temperature, humidity, …), which causes an unwanted signal drift. Recently, we presented the RT-QEPAS technique that consistently corrects the signal drift by continuously measuring the QTF resonance. In this article, we present an improvement of RT-QEPAS to fasten the QTF characterization time by adding a passive electronic circuit, which causes the damping of the QTF resonance. The damping circuit is optimized analytically and through SPICE simulation. The results are supported by experimental observations, showing a 70 times improvement of the relaxation times compared to the lone QTF, which opens the way to a fast and drift-free QEPAS sensor.

scholarly journals Decontamination of Powdery Foods Using an Intense Pulsed Light (IPL) Device for Practical Application

2021 ◽  
Vol 11 (4) ◽  
pp. 1518
Author(s):  
Hee-Jeong Hwang ◽  
So-Yoon Yee ◽  
Myong-Soo Chung
Keyword(s):  
Total Energy ◽  
Water Activity ◽  
Treatment Time ◽  
Sesame Seed ◽  
Pilot Scale ◽  
Black Pepper ◽  
Intense Pulsed Light ◽  
Pulsed Light ◽  
Energy Fluence ◽  
Color Changes

Controlling microbial problems when processing seeds and powdered foods is difficult due to their low water activity, irregular surfaces, and opaqueness. Moreover, existing thermal processing can readily cause various undesirable changes in sensory properties. Intense pulsed light (IPL) can be effective in nonthermal processing, and so two xenon lamps were attached to the sides of a self-designed cyclone type of pilot-scale IPL device. Each lamp was connected to its own power supply, and the following treatment conditions were applied to four sample types: lamp DC voltage of 1800–4200 V, pulse width of 0.5–1.0 ms, frequency of 2 Hz, and treatment time of 1–5 min. This device achieved reductions of 0.45, 0.66, and 0.88 log CFU/mL for ground black pepper, red pepper, and embryo buds of rice, respectively, under a total energy fluence of 12.31 J/cm2. Meanwhile, >3-log reductions were achieved for sesame seed samples under a total energy fluence of 11.26 J/cm2. In addition, analyses of color changes, water activity, and moisture content revealed no significant differences between the control and IPL-treated samples. These findings indicate that IPL treatment may be considered a feasible sterilization method for seeds and powdered foods.

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