Journal articles: 'Gas and liquid sensors'

1

Nazarava, K. U. "Liquid-Crystalline Infrared Gas Sensors." Molecular Crystals and Liquid Crystals 442, no. 1 (December 1, 2005): 93–102. http://dx.doi.org/10.1080/154214090964645.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Yu, Lei, Diego Garcia, Rex Ren, and Xiangqun Zeng. "Ionic liquid high temperature gas sensors." Chemical Communications, no. 17 (2005): 2277. http://dx.doi.org/10.1039/b501224d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Shibaev, P. V., M. Wenzlick, J. Murray, A. Tantillo, and J. Howard-Jennings. "Liquid Crystalline Compositions as Gas Sensors." Molecular Crystals and Liquid Crystals 611, no. 1 (April 13, 2015): 94–99. http://dx.doi.org/10.1080/15421406.2015.1027999.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Sedlak, Petr, Petr Kubersky, Pavel Skarvada, Ales Hamacek, Vlasta Sedlakova, Jiri Majzner, Stanislav Nespurek, and Josef Sikula. "Current Fluctuation Measurements of Amperometric Gas Sensors Constructed with Three Different Technology Procedures." Metrology and Measurement Systems 23, no. 4 (December 1, 2016): 531–43. http://dx.doi.org/10.1515/mms-2016-0042.

Full text

Abstract:

Abstract Electrochemical amperometric gas sensors represent a well-established and versatile type of devices with unique features: good sensitivity and stability, short response/recovery times, and low power consumption. These sensors operate at room temperature, and therefore have been applied in monitoring air pollutants and detection of toxic and hazardous gases in a number of areas. Some drawbacks of classical electrochemical sensors are overcome by the solid polymer electrolyte (SPE) based on ionic liquids. This work presents evaluation of an SPE-based amperometric sensor from the point of view of current fluctuations. The sensor is based on a novel three-electrode sensor platform with solid polymer electrolytes containing ionic liquid for detection of nitrogen dioxide − a highly toxic gas that is harmful to the environment and presenting a possible threat to human health even at low concentrations. The paper focuses on using noise measurement (electric current fluctuation measurement) for evaluation of electrochemical sensors which were constructed by different fabrication processes: (i) lift-off and drop-casting technology, (ii) screen printing technology on a ceramic substrate and (iii) screen printing on a flexible substrate.

APA, Harvard, Vancouver, ISO, and other styles

5

Ofuchi, César Y., Henrique K. Eidt, Carolina C. Rodrigues, Eduardo N. Dos Santos, Paulo H. D. Dos Santos, Marco J. Da Silva, Flávio Neves, Paulo Vinicius S. R. Domingos, and Rigoberto E. M. Morales. "Multiple Wire-Mesh Sensors Applied to the Characterization of Two-Phase Flow inside a Cyclonic Flow Distribution System." Sensors 19, no. 1 (January 7, 2019): 193. http://dx.doi.org/10.3390/s19010193.

Full text

Abstract:

Wire-mesh sensors are used to determine the phase fraction of gas–liquid two-phase flow in many industrial applications. In this paper, we report the use of the sensor to study the flow behavior inside an offshore oil and gas industry device for subsea phase separation. The study focused on the behavior of gas–liquid slug flow inside a flow distribution device with four outlets, which is part of the subsea phase separator system. The void fraction profile and the flow symmetry across the outlets were investigated using tomographic wire-mesh sensors and a camera. Results showed an ascendant liquid film in the cyclonic chamber with the gas phase at the center of the pipe generating a symmetrical flow. Dispersed bubbles coalesced into a gas vortex due to the centrifugal force inside the cyclonic chamber. The behavior favored the separation of smaller bubbles from the liquid bulk, which was an important parameter for gas-liquid separator sizing. The void fraction analysis of the outlets showed an even flow distribution with less than 10% difference, which was a satisfactorily result that may contribute to a reduction on the subsea gas–liquid separators size. From the outcomes of this study, detailed information regarding this type of flow distribution system was extracted. Thereby, wire-mesh sensors were successfully applied to investigate a new type of equipment for the offshore oil and gas industry.

APA, Harvard, Vancouver, ISO, and other styles

6

Carter, M. T., J. R. Stetter, M. W. Findlay, and V. Patel. "Amperometric Gas Sensors with Ionic Liquid Electrolytes." ECS Transactions 58, no. 34 (April 2, 2014): 7–18. http://dx.doi.org/10.1149/05834.0007ecst.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Becker, David, Robert Schmidt, Gerhard Lindner, and Klaus Stefan Drese. "Ultrasound Measurement Technique for Validation of Cryogenic Flows." Proceedings 2, no. 13 (December 11, 2018): 1090. http://dx.doi.org/10.3390/proceedings2131090.

Full text

Abstract:

An ultrasound sensor system based on the transmission-mode approach is developed to enable the monitoring and sensing of cryogenic liquids and gases—especially gaseous bubbles and gas-liquid interfaces in liquid nitrogen (LN2). Common sensors do not meet requirements of cryogenic and microgravity-environments. Therefore, a special encapsulation design for the optimization of the electrical connection and the mechanical coupling of the ultrasound sensors is needed. The ultrasound system is qualified in LN2 and is able to measure bubbles (size and location) and fill levels with a high spatial resolution in a submillimetre range and a sampling rate of more than 500 Hz.

APA, Harvard, Vancouver, ISO, and other styles

8

Kim, Inki, Won-Sik Kim, Kwan Kim, Muhammad Afnan Ansari, Muhammad Qasim Mehmood, Trevon Badloe, Yeseul Kim, et al. "Holographic metasurface gas sensors for instantaneous visual alarms." Science Advances 7, no. 15 (April 2021): eabe9943. http://dx.doi.org/10.1126/sciadv.abe9943.

Full text

Abstract:

The rapid detection of biological and chemical substances in real time is particularly important for public health and environmental monitoring and in the military sector. If the process of substance detection to visual reporting can be implemented into a single miniaturized sensor, there could be a profound impact on practical applications. Here, we propose a compact sensor platform that integrates liquid crystals (LCs) and holographic metasurfaces to autonomously sense the existence of a volatile gas and provide an immediate visual holographic alarm. By combining the advantage of the rapid responses to gases realized by LCs with the compactness of holographic metasurfaces, we develop ultracompact gas sensors without additional complex instruments or machinery to report the visual information of gas detection. To prove the applicability of the compact sensors, we demonstrate a metasurface-integrated gas sensor on safety goggles via a one-step nanocasting process that is attachable to flat, curved, and flexible surfaces.

APA, Harvard, Vancouver, ISO, and other styles

9

Zhang, Mingkuan, Xiaohong Wang, Zhiping Huang, and Wei Rao. "Liquid Metal Based Flexible and Implantable Biosensors." Biosensors 10, no. 11 (November 10, 2020): 170. http://dx.doi.org/10.3390/bios10110170.

Full text

Abstract:

Biosensors are the core elements for obtaining significant physiological information from living organisms. To better sense life information, flexible biosensors and implantable sensors that are highly compatible with organisms are favored by researchers. Moreover, materials for preparing a new generation of flexible sensors have also received attention. Liquid metal is a liquid-state metallic material with a low melting point at or around room temperature. Owing to its high electrical conductivity, low toxicity, and superior fluidity, liquid metal is emerging as a highly desirable candidate in biosensors. This paper is dedicated to reviewing state-of-the-art applications in biosensors that are expounded from seven aspects, including pressure sensor, strain sensor, gas sensor, temperature sensor, electrical sensor, optical sensor, and multifunctional sensor, respectively. The fundamental scientific and technological challenges lying behind these recommendations are outlined. Finally, the perspective of liquid metal-based biosensors is present, which stimulates the upcoming design of biosensors.

APA, Harvard, Vancouver, ISO, and other styles

10

Nazarava, K. U., and V. I. Navumenka. "Mid-infrared gas sensors of liquid crystal type." Ultramicroscopy 105, no. 1-4 (November 2005): 204–8. http://dx.doi.org/10.1016/j.ultramic.2005.06.037.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Han, Jialuo, Jiong Yang, Jianbo Tang, Mohammad B. Ghasemian, Lee J. Hubble, Nitu Syed, Torben Daeneke, and Kourosh Kalantar-Zadeh. "Liquid metals for tuning gas sensitive layers." Journal of Materials Chemistry C 7, no. 21 (2019): 6375–82. http://dx.doi.org/10.1039/c9tc01544b.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Iswanto, Iswanto, Alfian Ma’arif, Bilah Kebenaran, and Prisma Megantoro. "Design of gas concentration measurement and monitoring system for biogas power plant." Indonesian Journal of Electrical Engineering and Computer Science 22, no. 2 (May 1, 2021): 726. http://dx.doi.org/10.11591/ijeecs.v22.i2.pp726-732.

Full text

Abstract:

Biogas is a gas obtained from the breakdown of organic matter (such as animal waste, human waste, and plants) by methanogenic bacteria in an oxygen-free (anaerobic) state. The biogas produced mainly consists of 50-70% methane, 30-40% carbon dioxide, and other gases in small amounts. The gas produced has a different composition depending on the type of animal that produces it. It is challenging to obtain biogas concentration data because the monitoring equipment is currently minimal. Therefore, this research discusses how to make a monitoring system for biogas reactors. Sensors are installed in the digester tank and storage tank. The installed sensors are the MQ-4 sensor to detect methane gas (CH4), MG-811 sensor to detect carbon dioxide (CO2) gas, MQ-136 sensor to detect sulfide acid gas (H2S), and Thermocouple Type-K to detect temperature. The sensor will send a signal to the control unit in Arduino Mega 2560, then processed and displayed on the liquid crystal display (LCD). The sensor calculation results' accuracy is not much different from the reference based on the sensor readings. The sensor deviation standard is below 5.0, indicating that the sensor is in precision. The sensor's linearity of MQ-4 is 0.7%, the MG-811 is 0.17%, the MQ-136 is 0.29%, and the Type-K Thermocouple is 1.19%. The installed sensor can be used to monitor gas concentration and temperature in a biogas reactor.

APA, Harvard, Vancouver, ISO, and other styles

13

Smith, Natasha L., Zhenmin Hong, and Sanford A. Asher. "Responsive ionic liquid–polymer 2D photonic crystal gas sensors." Analyst 139, no. 24 (2014): 6379–86. http://dx.doi.org/10.1039/c4an01485e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Despot, Daneish, Micaela Pacheco Fernández, and Matthias Barjenbruch. "Comparison of Online Sensors for Liquid Phase Hydrogen Sulphide Monitoring in Sewer Systems." Water 13, no. 13 (July 5, 2021): 1876. http://dx.doi.org/10.3390/w13131876.

Full text

Abstract:

Hydrogen sulfide (H2S) related to wastewater in sewer systems is known for causing significant problems of corrosion and odor nuisance. Sewer systems severely affected by H2S typically rely on online H2S gas sensors for monitoring and control. However, these H2S gas sensors only provide information about the H2S emission potential at the point being monitored, which is sometimes inadequate to design control measures. In this study, a comparison of three market-ready online sensors capable of liquid-phase H2S detection in sewer systems was assessed and compared. Two of the three sensors are based on UV/Vis spectrophotometry, while the other adapted the design and principles of a Clark-type electrochemical microsensor. The H2S measurements of the sensors were statistically compared to a standard laboratory method at first. Following that, the performance of the online sensors was evaluated under realistic sewer conditions using the Berlin Water Company (BWB) research sewer pilot plant. Test applications representing scenarios of typical H2S concentrations found in sulfide-affected sewers and during control measures were simulated. The UV/Vis spectrometers showed that the performance of the sensors was highly dependent on the calibration type and measurements used for deriving the calibration function. The electrochemical sensor showed high sensitivity by responding to alternating anaerobic/anoxic conditions simulated during nitrate dosing. All sensors were prone to measurement disturbances due to high amounts of sanitary solids in wastewater at the study site and required continuous maintenance for reliable measurements. Finally, a summary of the key attributes and limitations of the sensors compared for liquid phase H2S detection is outlined.

APA, Harvard, Vancouver, ISO, and other styles

15

Bonilla Riaño, Adriana, Antonio Carlos Bannwart, and Oscar M. H. Rodriguez. "Film thickness planar sensor in oil-water flow: prospective study." Sensor Review 35, no. 2 (March 16, 2015): 200–209. http://dx.doi.org/10.1108/sr-09-2014-702.

Full text

Abstract:

Purpose – The purpose of this paper is to study a multiphase-flow instrumentation for film thickness measurement, especially impedance-based, not only for gas–liquid flow but also for mixtures of immiscible and more viscous substances such as oil and water. Conductance and capacitive planar sensors were compared to select the most suitable option for oil – water dispersed flow. Design/methodology/approach – A study of techniques for measurement of film thickness in oil – water pipe flow is presented. In the first part, some measurement techniques used for the investigation of multiphase flows are described, with their advantages and disadvantages. Next, examinations of conductive and capacitive techniques with planar sensors are presented. Findings – Film thickness measurement techniques for oil–water flow are scanty in the literature. Some techniques have been used in studies of annular flow (gas–liquid and liquid–liquid flows), but applications in other flow patterns were not encountered. The methods based on conductive or capacitive measurements and planar sensor are promising solutions for measuring time-averaged film thicknesses in oil–water flows. A capacitive system may be more appropriate for oil–water flows. Originality/value – This paper provides a review of film thickness measurements in pipes. There are many reviews on gas – liquid flow measurement but not many about liquid – liquid flow.

APA, Harvard, Vancouver, ISO, and other styles

16

Shibaev, P. V., M. Wenzlick, J. Murray, A. Tantillo, and J. Howard-Jennings. "Rebirth of Liquid Crystals for Sensoric Applications: Environmental and Gas Sensors." Advances in Condensed Matter Physics 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/729186.

Full text

Abstract:

Films and droplets of liquid crystals may soon become an essential part of sensitive environmental sensors and detectors of volatile organic compounds (VOCs) in the air. In this paper a short overview of recent progress in the area of sensors based on liquid crystals is presented, along with the studies of low molar mass liquid crystals as gas sensors. The detection of VOCs in the air may rely on each of the following effects sequentially observed one after the other: (i) slight changes in orientation and order parameter of liquid crystal, (ii) formation of bubbles on the top of the liquid crystalline droplet, and (iii) complete isotropisation of the liquid crystal. These three stages can be easily monitored by a photo camera and/or optical microscopy. Detection limits corresponding to the first stage are typically lower by a factor of at least 3–6 than detection limits corresponding to isotropisation. The qualitative model taking into account the reorientation of liquid crystals is presented to account for the observed changes.

APA, Harvard, Vancouver, ISO, and other styles

17

Zhao, Yong, Ya-Nan Zhang, and Qi Wang. "Research advances of photonic crystal gas and liquid sensors." Sensors and Actuators B: Chemical 160, no. 1 (December 2011): 1288–97. http://dx.doi.org/10.1016/j.snb.2011.09.064.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Jia, Hao, Pengcheng Xu, and Xinxin Li. "Integrated Resonant Micro/Nano Gravimetric Sensors for Bio/Chemical Detection in Air and Liquid." Micromachines 12, no. 6 (May 31, 2021): 645. http://dx.doi.org/10.3390/mi12060645.

Full text

Abstract:

Resonant micro/nanoelectromechanical systems (MEMS/NEMS) with on-chip integrated excitation and readout components, exhibit exquisite gravimetric sensitivities which have greatly advanced the bio/chemical sensor technologies in the past two decades. This paper reviews the development of integrated MEMS/NEMS resonators for bio/chemical sensing applications mainly in air and liquid. Different vibrational modes (bending, torsional, in-plane, and extensional modes) have been exploited to enhance the quality (Q) factors and mass sensing performance in viscous media. Such resonant mass sensors have shown great potential in detecting many kinds of trace analytes in gas and liquid phases, such as chemical vapors, volatile organic compounds, pollutant gases, bacteria, biomarkers, and DNA. The integrated MEMS/NEMS mass sensors will continuously push the detection limit of trace bio/chemical molecules and bring a better understanding of gas/nanomaterial interaction and molecular binding mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

19

Wang, Dayang, Ningde Jin, Lusheng Zhai, and Yingyu Ren. "Salinity Independent Flow Measurement of Vertical Upward Gas-Liquid Flows in a Small Pipe Using Conductance Method." Sensors 20, no. 18 (September 15, 2020): 5263. http://dx.doi.org/10.3390/s20185263.

Full text

Abstract:

Flow measurement in gas-liquid two-phase flow is always a challenging work, because of the non-uniform phase distribution, severe slippage effect between phases, and different flow structures. Furthermore, the variation of salinity changes the water conductivity, which brings more difficulties to multiphase flow measurement. In this study, a methodology for flow measurement using the conductance method in gas-liquid two-phase flow with salinity change is proposed. The methodology includes the suitable conductivity detection method, the strategy of using combined sensors, and the measurement models of flow parameters. A suitable conductivity detection method that can guarantee that the sensor output is linearly proportional to the conductivity is proposed. This conductivity detection method can ensure that the sensors have a high and constant resolution in the conductivity variation caused by water holdup under the conditions of water conductivity change. Afterward, a combined sensor system consisting of a water holdup sensor, velocity sensor, and water conductivity sensor is designed and experimentally evaluated in gas-water two-phase flow in a 20 mm inner diameter pipe. Considering the non-uniform phase distribution, severe slippage effect between phases, different flow structures, and the variation of salinity, a new water holdup measurement model and flow velocity measurement models are established to achieve salinity independent water holdup measurement and flow velocity measurement for the first time.

APA, Harvard, Vancouver, ISO, and other styles

20

Park, Jae Jung, Yongsoo Kim, Chanmin Lee, Jun-Won Kook, Donghyun Kim, Jung-Hyun Kim, Ki-Seob Hwang, and Jun-Young Lee. "Colorimetric Visualization Using Polymeric Core–Shell Nanoparticles: Enhanced Sensitivity for Formaldehyde Gas Sensors." Polymers 12, no. 5 (April 25, 2020): 998. http://dx.doi.org/10.3390/polym12050998.

Full text

Abstract:

Although equipment-based gas sensor systems (e.g., high-performance liquid chromatography) have been widely applied for formaldehyde gas detection, pre-treatment and expensive instrumentation are required. To overcome these disadvantages, we developed a colorimetric sensor based on polymer-based core–shell nanoparticles (PCSNPs), which are inexpensive, stable, and exhibit enhanced selectivity. Spherical and uniform poly(styrene-co-maleic anhydride) (PSMA)/polyethyleneimine (PEI) core–shell nanoparticles were prepared and then impregnated with Methyl Red (MR), Bromocresol Purple (BCP), or 4-nitrophenol (4-NP) to construct colorimetric sensors for formaldehyde gas. The intrinsic properties of these dyes were maintained when introduced into the PCSNPs. In the presence of formaldehyde, the MR, BCP, and 4-NP colorimetric sensors changed to yellow, red, and gray, respectively. The colorimetric response was maximized at a PEI/PSMA ratio of four, likely owing to the high content of amine groups. Effective formaldehyde gas detection was achieved at a relative humidity of 30% using the MR colorimetric sensor, which exhibited a large color change (92%) in 1 min. Advantageously, this stable sensor allowed sensitive and rapid naked-eye detection of low formaldehyde concentrations (0.5 ppm). Hence, this approach is promising for real-time formaldehyde gas visualization and can also be adapted to other colorimetric gas sensor systems to improve sensitivity and simplicity.

APA, Harvard, Vancouver, ISO, and other styles

21

Vistak, Maria, Taras Prystay, Vasyl Petryshak, Orest Sushynskyi, and Zinoviy Mikityuk. "Dynamic characteristics of nanocomposite on the basis of porous Al2O3 doped by liquid crystal with magnetite under carbon monoxide influence." Photonics Letters of Poland 8, no. 4 (December 31, 2016): 119. http://dx.doi.org/10.4302/plp.2016.4.10.

Full text

Abstract:

In this paper dynamics characteristics of nanocomposite on the basis of cholesteric liquid crystal (CLC) with magnetite dopant introduced into porous structures are studied. We studied the behavior of spectral characteristics of transmittance of CLC2103L with Fe3O4 introduced in porous structures of Al2O3 under carbon monoxide influence. The diameter pores of Al2O3 is 20 nm, 35 nm and 50 nm, and CO concentration is in the range of 0-100 mg/m3. Interaction of investigated nanocomposite is the most intensive in the first minutes of CO influence. Further increase of interaction time does not lead to changes in the structure of the CLC. Full Text: PDF ReferencesS. Youssef, J. Podlecki, R. Habchi, M. Brouche, A. Foucarana, D. Bouvier, N. Brillouet, P. Coudray, "Innovative prototype of a zinc-oxide based optical gas sensor", Sens. and Act. B. 173, 391 (2012). CrossRef N.Yamazoe, G. Sakai, K. Shimanoe, "Oxide Semiconductor Gas Sensors", Catalysis Surveys from Asia 7, 63 (2003). CrossRef B. W. Kooa, C. K. Songa, C. Kimb, "CO gas sensor based on a conducting dendrimer", Sens. and Act. B 77. 432 (2001). CrossRef O. Sushynskyi, M. Vistak, Z. Gotra, A. Fechan, Z. Mikityuk, "Silicon dioxide nanoporous structure with liquid crystal for optical sensors", Proc. SPIE 9127, 91271F (2014). CrossRef A. Andrushchak, Z. Hotra, Z. Mykytyuk, M. Vistak, T. Prystay, O. Sushynskyi, "Nanostructures on the Basis of Porous Alumina with Intercalated with Cholesteric Liquid Crystal", Mol. Cryst. and Liq. Cryst. 611, 132 (2015). CrossRef O. Aksimentyeva, Z. Mykytyuk, A. Fechan, B.Tsizh, O. Sushynskyi, "Cholesteric Liquid Crystal Doped by Nanosize Magnetite as an Active Medium of Optical Gas Sensor", Mol. Cryst. and Liq. Cryst. 589, 83 (2014). CrossRef M. Vistak, O. Sushynsky, Z. Mykytyuk, O. Aksimentyeva, Y. Semenova, "Sensing of carbon monoxide with porous Al2O3 intercalated with Fe3O4 nanoparticles-doped liquid crystal", Sens. and Act. A: Physical. 235, 165 (2015). CrossRef

APA, Harvard, Vancouver, ISO, and other styles

22

Zhan, Zhipeng. "An amperometric H2 gas sensor based on ionic liquid for hydrogen fuel cell ships." E3S Web of Conferences 261 (2021): 02013. http://dx.doi.org/10.1051/e3sconf/202126102013.

Full text

Abstract:

Hydrogen fuel cell ship is an important way to realize green shipping, and the safety of hydrogen fuel ship is primary issue that shall be concerned. H2 gas sensors can provide online monitoring of H2 concentration and it is an effective mean to insure safety of hydrogen fuel. In this study, an amperometric electrochemical H2 gas sensor based on room-temperature ionic liquid was developed, which was expected to be applicable to monitoring of H2 concentration in the hydrogen fuel cell ship. A threeelectrode H2 gas sensor was fabricated by using room-temperature ionic liquid N, N, N-trimethyl-Nbutanesulfonic acid ammonium hydrogen sulfate ([TMBSA][HSO4]) as electrolyte and using platinum black as catalyst. The H2 gas sensor not only had the advantages of the conventional aqueous electrolyte sensor, such as high sensitivity, fast response, and the linear relationship between the response current and the concentration of H2, but also overcame the problem that the conventional electrochemical gas sensor cannot be applied to high humidity environment. After storage in high-humidity environment (98% RH) for three weeks, the sensor had stable performances, with current signal drift less than 2.25%. The sensor has a good potential application prospect in ships with high temperature and humidity environment.

APA, Harvard, Vancouver, ISO, and other styles

23

Chaudhari, G. N., D. R. Bambole, and A. B. Bodade. "Structural and gas sensing behavior of nanocrystalline BaTiO3 based liquid petroleum gas sensors." Vacuum 81, no. 3 (October 2006): 251–56. http://dx.doi.org/10.1016/j.vacuum.2006.03.026.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Chaisitsak, Sutichai. "Nanocrystalline SnO2:F Thin Films for Liquid Petroleum Gas Sensors." Sensors 11, no. 7 (July 11, 2011): 7127–40. http://dx.doi.org/10.3390/s110707127.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Elkow, Kenneth J., and Kamiel S. Rezkallah. "Void fraction measurements in gas - liquid flows using capacitance sensors." Measurement Science and Technology 7, no. 8 (August 1, 1996): 1153–63. http://dx.doi.org/10.1088/0957-0233/7/8/011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Carter, M. T., J. R. Stetter, M. W. Findlay, and V. Patel. "Rational Design of Amperometric Gas Sensors with Ionic Liquid Electrolytes." ECS Transactions 64, no. 1 (August 12, 2014): 95–103. http://dx.doi.org/10.1149/06401.0095ecst.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

de Mas, Nuria, Axel Günther, Tobias Kraus, Martin A. Schmidt, and Klavs F. Jensen. "Scaled-Out Multilayer Gas−Liquid Microreactor with Integrated Velocimetry Sensors." Industrial & Engineering Chemistry Research 44, no. 24 (November 2005): 8997–9013. http://dx.doi.org/10.1021/ie050472s.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Otono, Yuki, Khai Jun Kek, Jovia Jia Zhen Lee, Shoichi Ishihara, Yusuke Nakano, Kiyoshi Hashimotodani, and Hiroaki Oka. "75-3: Chemical Gas Sensors using Chiral Nematic Liquid Crystals." SID Symposium Digest of Technical Papers 47, no. 1 (May 2016): 1021–24. http://dx.doi.org/10.1002/sdtp.10898.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Suter, Jonathan D., Cameron J. Hohimer, Jacob M. Fricke, Josef Christ, Hanseup Kim, and Allan T. Evans. "Principles of Meniscus-Based MEMS Gas or Liquid Pressure Sensors." Journal of Microelectromechanical Systems 22, no. 3 (June 2013): 670–77. http://dx.doi.org/10.1109/jmems.2013.2239258.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Silvester, Debbie S. "New innovations in ionic liquid–based miniaturised amperometric gas sensors." Current Opinion in Electrochemistry 15 (June 2019): 7–17. http://dx.doi.org/10.1016/j.coelec.2019.03.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Arunkumar, S., J. Adhavan, M. Venkatesan, S. K. Das, and A. R. Balakrishnan. "Characterization of gas-liquid two phase flows using dielectric Sensors." Flow Measurement and Instrumentation 45 (October 2015): 274–79. http://dx.doi.org/10.1016/j.flowmeasinst.2015.07.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Fernández-Ramos, María Dolores, Fátima Mirza-Montoro, Luis Fermín Capitán-Vallvey, and Isabel María Pérez de Vargas-Sansalvador. "Near Infrared Sensor to Determine Carbon Dioxide Gas Based on Ionic Liquid." Coatings 11, no. 2 (January 30, 2021): 163. http://dx.doi.org/10.3390/coatings11020163.

Full text

Abstract:

In this study we present an NIR carbon dioxide gas sensor based on an inner filter process that includes an ionic liquid (IL), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), to improve its stability, dynamic behavior and lifetime, which are usually the main drawbacks with these sensors. The presence of CO2 causes a displacement of a simple boron-dipyrromethene-type fluorophore, azaBODIPY, as the pH indicator towards its acid form. This increases the emission intensity of Cr(III)-doped gadolinium aluminium borate (GAB) as the luminophore. The characterization of the prepared sensor was carried out and a discussion of the results is presented. The response and recovery times improved considerably, 23 and 49 s, respectively, with respect to the sensor without IL, at 60 and 120 s, respectively,. Additionally, the measurement range is extended when using IL, able in this case to measure in the complete range up to 100% CO2; without IL the measurement range is limited to 60% CO2. The detection limit ranges from 0.57% CO2 without IL to 0.26% CO2 when IL is added. The useful lifetime of the sensing membrane was 20 days for membranes with IL and only 6 days for membranes without IL, with the sensor always kept in the dark and without the need to maintain a special atmosphere.

APA, Harvard, Vancouver, ISO, and other styles

33

Miniaev, M. V., M. B. Belyakova, N. V. Kostiuk, D. V. Leshchenko, and T. A. Fedotova. "Non-obvious Problems in Clark Electrode Application at Elevated Temperature and Ways of Their Elimination." Journal of Analytical Methods in Chemistry 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/249752.

Full text

Abstract:

Well-known cause of frequent failures of closed oxygen sensors is the appearance of gas bubbles in the electrolyte. The problem is traditionally associated with insufficient sealing of the sensor that is not always true. Study of a typical temperature regime of measurement system based on Clark sensor showed that spontaneous release of the gas phase is a natural effect caused by periodic warming of the sensor to a temperature of the test liquid. The warming of the sensor together with the incubation medium causes oversaturation of electrolyte by dissolved gases and the allocation of gas bubbles. The lower rate of sensor heating in comparison with the medium reduces but does not eliminate the manifestation of this effect. It is experimentally established, that with each cycle of heating of measuring system up to 37°C followed by cooling the volume of gas phase in the electrolyte (KCl; 60 g/L; 400 μL) increased by 0.6 μL approximately. Thus, during just several cycles it can dramatically degrade the characteristics of the sensor. A method was developed in which the oxygen sensor is heated in contact with the liquid, (depleted of dissolved gases), allowing complete exclusion of the above-mentioned effect.

APA, Harvard, Vancouver, ISO, and other styles

34

Ren, Fu Jian, Yi Sun, Liang Huang, Yun Han Ling, and Jia You Feng. "Low-Temperature Synthesis and Gas Sensing Properties of Anatase TiO₂ Thin Films." Key Engineering Materials 492 (September 2011): 300–303. http://dx.doi.org/10.4028/www.scientific.net/kem.492.300.

Full text

Abstract:

Crystalline anatase TiO2thin films were obtained on glass substrates at 60°C, 75°C and 90°C, respectively, by liquid phase deposition (LPD) method without subsequent heat treatment. X-ray diffraction (XRD), atomic force microscopy (AFM) and UV-Vis spectrophotometer were used to characterize the as-synthesized TiO2thin films. The H2sensing properties of the TiO2thin films based sensors were investigated. The results show that the gas sensors signal Ra/Rg (Ra: resistance in air, Rg: resistance in a sample gas) decreases with the increasing deposition temperature. The TiO2thin films obtained at deposition temperature of 60°C exhibited the maximum H2gas response at 350°C, and the magnitude of the sensor signal and the response time for 500ppm H2was 1.25 and 17s, respectively.

APA, Harvard, Vancouver, ISO, and other styles

35

Setyawan, Andriyanto, Indarto, Deendarlianto, and Apip Badarudin. "Effects of Liquid Viscosity on the Wave Velocity and Wave Frequency in Horizontal Annular Flow." Applied Mechanics and Materials 758 (April 2015): 7–12. http://dx.doi.org/10.4028/www.scientific.net/amm.758.7.

Full text

Abstract:

An investigation on the liquid holdup, wave velocity, and wave frequency in horizontal annular flow has been experimentally conducted through the measurement of liquid holdup using constant electric current method (CECM) sensors. To investigate the effect of viscosity, water and glycerin were used as working liquid, using superficial liquid velocity and superficial gas velocity of 0.05 to 0.2 m/s and 12 to 40 m/s, respectively. Liquids with higher viscosity give the higher liquid holdup, lower wave velocity, and lower wave frequency. Correlations for liquid holdup and mean film thickness, wave velocity, and wave frequency have been developed with mean average errors (MAE) of 13.5%, 9.2%, and 8.6%, respectively.

APA, Harvard, Vancouver, ISO, and other styles

36

Kleiza, V., and J. Verkelis. "Some Advanced Fiber-Optical Amplitude Modulated Reflection Displacement and Refractive Index Sensors." Nonlinear Analysis: Modelling and Control 12, no. 2 (April 25, 2007): 213–25. http://dx.doi.org/10.15388/na.2007.12.2.14712.

Full text

Abstract:

Some advanced fiber-optic amplitude modulated reflection displacement sensors and refractive index sensors have been developed. An improved three-fiber displacement sensor has been investigated as a refractive index sensor by computer simulations in a large interval of displacement. Some new regularities have been revealed. A reflection fiber-optic displacement sensor of novel configuration, consisting of double optical-pair fibers with a definite angle between the measuring tips of fibers in the pairs has been proposed, designed, and experimentally investigated to indicate and measure the displacement and refractive index of gas and liquid water solutions. The proposed displacement sensor and refractive index sensor configuration improves the measuring sensitivity in comparison with the known measuring methods. The refractive index sensor sensitivity Snsub = 4 × 10−7 RIU/mV was achieved. The displacement sensor sensitivity is Ssub = 1702 mV/µm in air (n = 1.00027).

APA, Harvard, Vancouver, ISO, and other styles

37

Nauber, A., and P. Tschuncky. "Toxic Gas Sensors Using Ionic Liquids." ECS Transactions 58, no. 21 (February 27, 2014): 33–38. http://dx.doi.org/10.1149/05821.0033ecst.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Toma, P., R. Ridley, and M. Chen. "A Gas-Liquid Flowmeter Combining Vertical and Horizontal Pressure Fluctuations Induced by Local Void Fraction Variations." Journal of Energy Resources Technology 125, no. 1 (March 1, 2003): 35–42. http://dx.doi.org/10.1115/1.1514214.

Full text

Abstract:

Two AC signals generated by two sensors mounted in two elbows at the ends of vertical and horizontal branches of a metering pipe are simultaneously recorded and analyzed. The AC signals are mainly due to fluctuations in stagnation-pressure caused by the local oscillations of local void fraction and to transport velocity of the gas-liquid flow. Features extracted from stochastic interpretation of the two signals are strongly related to gas and liquid flowrates. Laboratory and field testing of the new meter demonstrated that, for the same gas and liquid flowrates, probability distribution functions (PDF) determined from statistical analysis of “vertical” and “horizontal” AC signals are unique. For broad ranges of gas-liquid ratios, features extracted from the PDF are linearly related to gas and liquid flowrates.

APA, Harvard, Vancouver, ISO, and other styles

39

Kim, Ha-Na, Yong-Geun Kim, and Sun-Tae Kim. "Comparison of sensitivity of gas sensors for liquid n-Butanol analysis." Journal of Odor and Indoor Environment 16, no. 1 (March 31, 2017): 64–71. http://dx.doi.org/10.15250/joie.2017.16.1.64.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Gondosiswanto, Richard, D. Brynn Hibbert, Yu Fang, and Chuan Zhao. "Ionic Liquid Microstrips Impregnated with Magnetic Nanostirrers for Sensitive Gas Sensors." ACS Applied Materials & Interfaces 9, no. 49 (November 28, 2017): 43377–85. http://dx.doi.org/10.1021/acsami.7b14657.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Yao, Nan, Yue Cai, and Yang Liu. "Application of 3D Visualization Recognition in Liquid Composites-Based Gas Sensors." Sensor Letters 14, no. 3 (March 1, 2016): 304–9. http://dx.doi.org/10.1166/sl.2016.3670.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Kek, Khai Jun, Jovia Jia Zhen Lee, Yuki Otono, and Shoichi Ishihara. "Chemical gas sensors using chiral nematic liquid crystals and its applications." Journal of the Society for Information Display 25, no. 6 (June 2017): 366–73. http://dx.doi.org/10.1002/jsid.560.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Gao, Lei, Changqing Yin, Yuanyuan Luo, and Guotao Duan. "Facile Synthesis of the Composites of Polyaniline and TiO2 Nanoparticles Using Self-Assembly Method and Their Application in Gas Sensing." Nanomaterials 9, no. 4 (March 30, 2019): 493. http://dx.doi.org/10.3390/nano9040493.

Full text

Abstract:

The composites of polyaniline and TiO2 nanoparticles with different contents were prepared in the aqueous solution of phosphoric acid, in which the phosphoric acid was selected as the protonic acid to improve the conductivity of polyaniline. In the composites, the TiO2 nanoparticles with the size of about 20 nm were coated by a layer of polyaniline film with a thickness of about 5 nm. Then, the gas sensors were constructed by a liquid–gas interfacial self-assembly method. The gas-sensing properties of the composites-based gas sensors obviously improved after doping with TiO2 nanoparticles, and the sensor response of the composites increased several times to NH3 from 10 ppm to 50 ppm than that of pure polyaniline. Especially when the mass ratio of TiO2 to aniline monomer was 2, it exhibited the best gas response (about 11.2–50 ppm NH3), repeatability and good selectivity to NH3 at room temperature. The p–n junction structure consisting of the polyaniline and TiO2 nanoparticles played an important role in improving gas-sensing properties. This paper will provide a method to improve the gas-sensing properties of polyaniline and optimum doping proportion of TiO2 nanoparticles.

APA, Harvard, Vancouver, ISO, and other styles

44

Yamanaka, Kazushi. "Ball SAW Sensors for Safety and Reliability of Fuel Cell Technologies." Key Engineering Materials 321-323 (October 2006): 48–52. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.48.

Full text

Abstract:

Detection of hydrogen gas is a crucial task for establishing safety and reliability of fuel cells, a key technology for the environment and our society. However, hydrogen is difficult to detect and various hydrogen sensors have many drawbacks. Here we report a novel hydrogen gas sensor, the ball surface acoustic wave (SAW) sensor, using Pd or PdNi sensitive film. The ball SAW sensor is based on a novel phenomenon, diffraction-free propagation of collimated beam along an equator of sphere. The resultant ultra-multiple roundtrips of SAW makes it possible to achieve highest sensitivity among SAW sensors. Moreover, it enables to use a very thin sensitive film, and consequently the shortest response time (2s) was realized. In terms of the sensing range, it has the widest range of 10 ppm to 100 % among any hydrogen sensors including FET or resistivity sensors. The ball SAW sensor can be applied not only to hydrogen but also to any gasses and possibly to liquids.

APA, Harvard, Vancouver, ISO, and other styles

45

Kuchmenko and Lvova. "A Perspective on Recent Advances in Piezoelectric Chemical Sensors for Environmental Monitoring and Foodstuffs Analysis." Chemosensors 7, no. 3 (August 26, 2019): 39. http://dx.doi.org/10.3390/chemosensors7030039.

Full text

Abstract:

This paper provides a selection of the last two decades publications on the development and application of chemical sensors based on piezoelectric quartz resonators for a wide range of analytical tasks. Most of the attention is devoted to an analysis of gas and liquid media and to industrial processes controls utilizing single quartz crystal microbalance (QCM) sensors, bulk acoustic wave (BAW) sensors, and their arrays in e-nose systems. The unique opportunity to estimate several heavy metals in natural and wastewater samples from the output of a QCM sensor array highly sensitive to changes in metal ion activity in water vapor is shown. The high potential of QCM multisensor systems for fast and cost-effective water contamination assessments “in situ” without sample pretreatment is demonstrated.

APA, Harvard, Vancouver, ISO, and other styles

46

Sedlák, Petr, Petr Kuberský, Adam Gajdoš, Jiří Majzner, Vlasta Sedláková, Robert Macků, and Vladimír Holcman. "Effect of the Different Crystallinity of Ionic Liquid Based Solid Polymer Electrolyte on the Performance of Amperometric Gas Sensor." Engineering Proceedings 2, no. 1 (November 14, 2020): 37. http://dx.doi.org/10.3390/ecsa-7-08166.

Full text

Abstract:

Solid polymer electrolytes (SPE) based on ionic liquid, poly-(vinylidene fluoride) and solvent N-methyl-pyrrolidone represent an effective component in electrochemical sensors. The advantage lies in their composition, which offers an opportunity to prepare SPE layers with a different porosity and microstructure. The study shows how the SPEs of different crystallinities affect the performance of an amperometric gas sensor from the point of view of current response (sensitivity), limit of detection and current fluctuations. The morphology of SPE has an impact not only on its conductivity but also on sensor sensitivity due to the morphology of the interface SPE/working electrode (WE).

APA, Harvard, Vancouver, ISO, and other styles

47

Salinas Alvarez, Carlos, Daniel Sierra–Sosa, Begonya Garcia–Zapirain, Deborah Yoder–Himes, and Adel Elmaghraby. "Detection of Volatile Compounds Emitted by Bacteria in Wounds Using Gas Sensors." Sensors 19, no. 7 (March 28, 2019): 1523. http://dx.doi.org/10.3390/s19071523.

Full text

Abstract:

In this paper we analyze an experiment for the use of low-cost gas sensors intended to detect bacteria in wounds using a non-intrusive technique. Seven different genera/species of microbes tend to be present in most wound infections. Detection of these bacteria usually requires sample and laboratory testing which is costly, inconvenient and time-consuming. The validation processes for these sensors with nineteen types of microbes (1 Candida, 2 Enterococcus, 6 Staphylococcus, 1 Aeromonas, 1 Micrococcus, 2 E. coli and 6 Pseudomonas) are presented here, in which four sensors were evaluated: TGS-826 used for ammonia and amines, MQ-3 used for alcohol detection, MQ-135 for CO2 and MQ-138 for acetone detection. Validation was undertaken by studying the behavior of the sensors at different distances and gas concentrations. Preliminary results with liquid cultures of 108 CFU/mL and solid cultures of 108 CFU/cm2 of the 6 Pseudomonas aeruginosa strains revealed that the four gas sensors showed a response at a height of 5 mm. The ammonia detection response of the TGS-826 to Pseudomonas showed the highest responses for the experimental samples over the background signals, with a difference between the values of up to 60 units in the solid samples and the most consistent and constant values. This could suggest that this sensor is a good detector of Pseudomonas aeruginosa, and the recording made of its values could be indicative of the detection of this species. All the species revealed similar CO2 emission and a high response rate with acetone for Micrococcus, Aeromonas and Staphylococcus.

APA, Harvard, Vancouver, ISO, and other styles

48

Choi, Jung-Min, Kye-Won Park, Jae-Gun Jeong, Yong-Kwon Lee, Gil-Nam Kim, Doo-Chan Choi, and Min-Hyuk Ko. "Experimental Study on the Availability of Fire Detection Using Gas Sensors for Air Quality Measurement." Fire Science and Engineering 35, no. 1 (February 28, 2021): 41–47. http://dx.doi.org/10.7731/kifse.0759bab4.

Full text

Abstract:

This study tested gas sensors used to measure indoor air quality to explore the feasibility of using them as detection sensors in case of fire. A B-class fire environment was implemented in the compartment (ISO 9705 standard fire room), and four types of high- and low- accuracy and priced gas sensors (Carbon monoxide, carbon dioxide, methane, t-VOC) used for indoor air quality measurement were installed. From ignition of the fuel to alarming of the heat detector, the responses from the sensors were analyzed. The results revealed the following: 1) Among the four types of sensors, CO and t-VOC sensors were effective as fire detection sensors in terms of their concentration increase and response time. 2) Low-accuracy CO2 and CH4 sensors were not effective in fire detection as they responded late relatively to CO and t-VOC sensors. 3) It was confirmed that low-accuracy gas sensors are feasible for use for fire detection in that they showed valid increase in concentration before the heat detector alarms. However, as only liquid combustible (Heptane) was applied as a fire source, analysis in an environment where different types of combustibles are used will be necessary in the future.

APA, Harvard, Vancouver, ISO, and other styles

49

Li, Jinku, Delin Hu, Wei Chen, Yi Li, Maomao Zhang, and Lihui Peng. "CNN-Based Volume Flow Rate Prediction of Oil–Gas–Water Three-Phase Intermittent Flow from Multiple Sensors." Sensors 21, no. 4 (February 10, 2021): 1245. http://dx.doi.org/10.3390/s21041245.

Full text

Abstract:

In this paper, we propose a deep-learning-based method using a convolutional neural network (CNN) to predict the volume flow rates of individual phases in the oil–gas–water three-phase intermittent flow simultaneously by analyzing the measurement data from multiple sensors, including a temperature sensor, a pressure sensor, a Venturi tube and a microwave sensor. To build datasets, a series of experiments for the oil–gas–water three-phase intermittent flow in a horizontal pipe, in which gas volume fraction and water-in-liquid ratio ranges are 23.77–94.45% and 14.95–86.97%, respectively, and gas flow superficial velocity and liquid flow superficial velocity ranges are 0.66–5.23 and 0.27–2.14 m/s, respectively, have been carried out on a test loop pipeline. The preliminary results indicate that the model can provide relative prediction errors on the testing-1 dataset for the volume flow rates of oil-phase, gas-phase and water-phase within ±10% with 94.49%, 92.56% and 95.71% confidence levels, respectively. Additionally, the prediction results on the testing-2 dataset also demonstrate the generalization ability of the model. The consuming time of a prediction with one sample is 0.43 s on an Intel Xeon CPU E5-2678 v3, and 0.01 s on an NVIDIA GeForce GTX 1080 Ti GPU. Hence, the proposed CNN-based prediction model, which can fulfill the real-time application requirements in the petroleum industry, reveals the potential of using deep learning to obtain accurate results in the multiphase flow measurement field.

APA, Harvard, Vancouver, ISO, and other styles

50

Kim, Yeon Hoo, Kye Yeop Kim, You Rim Choi, Young-Seok Shim, Jong-Myeong Jeon, Jong-Heun Lee, Soo Young Kim, Seungwu Han, and Ho Won Jang. "Ultrasensitive reversible oxygen sensing by using liquid-exfoliated MoS2 nanoparticles." Journal of Materials Chemistry A 4, no. 16 (2016): 6070–76. http://dx.doi.org/10.1039/c6ta01277a.

Full text

Abstract:

Two-dimensional (2D) molybdenum disulfide (MoS₂) has been attracting rapidly increasing interest for application in chemoresistive gas sensors owing to its moderate band gap energy and high specific surface area.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Gas and liquid sensors'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles