scholarly journals Optical Sensor for Real-Time Detection of Trichlorofluoromethane

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 632 ◽  
Author(s):  
Maiko Girschikofsky ◽  
Dimitrij Ryvlin ◽  
Siegfried Waldvogel ◽  
Ralf Hellmann

Trichlorofluoromethane was once a promising and versatile applicable chlorofluorocarbon. Unaware of its ozone-depleting character, for a long time it was globally applied as propellant and refrigerant and thus led to significant thinning of the ozone layer and contributed to the formation of the so-called ozone hole. Although production and application of this substance were gradually reduced at an early stage, we still face the consequences of its former careless use. Today, trichlorofluoromethane is released during recycling processes of waste cooling devices, traded on the black market, and according to recent findings still illegally manufactured. Here, we present an optical sensor device for real-time in-situ detection and measurement of this environmentally harmful chlorofluorocarbon. The described sensor is based on a planar Bragg grating that is functionalized with cyclodextrin derivatives and operates on the principle of a chemical sensor. In our study, the sensor is sensitized using per-methyl-, per-ethyl-, and per-allyl-substituted α -, β -, and γ -cyclodextrins as affinity materials for airborne trichlorofluoromethane. These functional coatings have been proven to be highly efficient, as an up to 400-times stronger signal deflection could be achieved compared to an identical but uncoated sensor. The presented sensor device shows instantaneous response to trichlorofluoromethane exposure, and features a limit-of-detection of less than 25 ppm, depending on the applied affinity material.

Optik ◽  
2021 ◽  
pp. 167711
Author(s):  
Enlai Wan ◽  
Zhongmou Sun ◽  
Yuzhu Liu

Polyhedron ◽  
2019 ◽  
Vol 170 ◽  
pp. 639-648
Author(s):  
Anke Kabelitz ◽  
Hoang An Dinh ◽  
Franziska Emmerling

2018 ◽  
Vol 232 ◽  
pp. 04053
Author(s):  
Cheng-xing Miao ◽  
Qing Li ◽  
Sheng-yao Jia

In order to get ridded of the non real-time detection methods of artificial site sampled and laboratory instrument analyzed in the field of methane detection in the offshore shallow gas, real-time in-situ detection system for methane in offshore shallow gas was designed by the film interface.The methane in the offshore shallow gas through the gas-liquid separation membrane of polymer permeation into the system internal detection probe, analog infrared micro gas sensor sensed the methane concentration and the corresponded output value, data acquisition and communication node fitted into standard gas concentration.Based on the experimental data compared with the traditional detection method, and further analyzed the causes of error produced by the case experiment. The application results show that the system can achieve a single borehole layout, long-term on-line in-situ on-line detection, and improve the detection efficiency and the timeliness of the detection data.


2020 ◽  
Vol 127 (2) ◽  
pp. 291-299 ◽  
Author(s):  
Rajendra P. Shukla ◽  
Robert H. Belmaker ◽  
Yuly Bersudsky ◽  
Hadar Ben-Yoav

AbstractOlanzapine is a thienobenzodiazepine compound. It is one of the newer types of antipsychotic drugs used in the treatment of schizophrenia and other psychotic disorders. Several methods have been reported for analyzing olanzapine in its pure form or combined with other drugs and in biological fluids. These methods include high-performance liquid chromatography and liquid chromatography-tandem mass spectroscopy. Although many of the reported methods are accurate and sensitive, they require the use of sophisticated equipment, lack in situ analysis, and require expensive reagents. Moreover, several of these methods are cumbersome, require prolonged sample pretreatment, strict control of pH, and long reaction times. Here we present the development of a miniaturized electrochemical sensor that will enable minimally invasive, real-time, and in situ monitoring of olanzapine levels in microliter volumes of serum samples. For this purpose, we modified a microfabricated microelectrode with a platinum black film to increase the electrocatalytic activity of the microelectrode towards olanzapine oxidation; this improved the overall selectivity and sensitivity of the sensor. We observed in recorded voltammograms the anodic current dose response characteristics in microliter volumes of olanzapine-spiked serum samples that resulted in a limit of detection of 28.6 ± 1.3 nM and a sensitivity of 0.14 ± 0.02 µA/cm2 nM. Importantly, the platinum black-modified microelectrode exhibited a limit of detection that is below the clinical threshold (65–130 nM). Further miniaturizing and integrating such sensors into point-of-care devices provide real-time monitoring of olanzapine blood levels; this will enable treatment teams to receive feedback and administer adjustable olanzapine therapy.


2009 ◽  
Vol 2 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Craig Baker-Austin ◽  
Anthony Gore ◽  
James D. Oliver ◽  
Rachel Rangdale ◽  
J Vaun McArthur ◽  
...  

2014 ◽  
Vol 679 ◽  
pp. 176-183
Author(s):  
Ahmad Zulhusny Rozali ◽  
Robert Stewart ◽  
Sean Kennedy

WSN technology has now become ubiquitous due to its flexibility, efficiency and affordability. For example the nodes in a WSN can be easily deployed in any targeted area and last for many years. The nodes can supply reliable data from within the environment with minimal disturbance to the target area.However challenges remain in providing real-time communication in some communication hostile conditions. It may not always be possible to leave the sensors in situ but instead data collection is through the use of mobile a WSN. For example as a vehicle fitted with sensing devices passes through an area of interest data is collected and relayed at certain gateway nodes back to a backhaul network for processing.In this paper our aim is to analyse the interference caused by a mobile jammer node to the stationary transmitter and receiver nodes in a network by using the OPNET Modeler software. This is early stage work aimed at developing a mobile WSN node in our future research.


2004 ◽  
Vol 19 (02) ◽  
pp. 94-99 ◽  
Author(s):  
J.K. Smith ◽  
M. Yuan ◽  
T.H. Lopez ◽  
M. Means ◽  
J.L. Przybylinski

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