scholarly journals Principles and Applications of Ceramic Humidity Sensors

1994 ◽  
Vol 16 (2) ◽  
pp. 69-87 ◽  
Author(s):  
Mario Pelino ◽  
Carlo Cantalini ◽  
Marco Faccio
Keyword(s):  
Impedance Spectroscopy ◽  
Relative Humidity ◽  
Response Time ◽  
State Of The Art ◽  
The State ◽  
Experimental Techniques ◽  
Humidity Sensors ◽  
Temperature Range ◽  
Si Doped ◽  
Signal Response

This paper presents a brief review of the state of the art in humidity and gas ceramic sensors R&D; it also describes the principle, fabrication and application of the humidity-sensitive Si-doped a-hematite (α-Fe2O3) sintered compacts. The humidity signal response is characterized by volt-amperometric and impedance spectroscopy techniques in the 0-97% relative humidity (RH) range. The response time of the sensor is evaluated by 0-60% RH variations. Experimental techniques used to measure the hysteresis, drift, and aging of the humidity setasor are presented and the results are discussed. The CO sensitivity is investigated by activating the sensor in the 350-450℃ temperature range. A humidity-meter prototype, based on the α-Fe2O3ceramic compact is described, and its electronics and features are presented in this paper.

scholarly journals Designing of Nanomaterials-Based Enzymatic Biosensors: Synthesis, Properties, and Applications

Electrochem ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 149-184
Author(s):  
Francisco T. T. Cavalcante ◽  
Italo R. R. de A. Falcão ◽  
José E. da S. Souza ◽  
Thales G. Rocha ◽  
Isamayra G. de Sousa ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
State Of The Art ◽  
Volume Ratio ◽  
The State ◽  
Future Research ◽  
Synthesis Properties ◽  
Signal Response ◽  
Enzymatic Biosensors ◽  
The Many ◽  
Biological Entities

Among the many biological entities employed in the development of biosensors, enzymes have attracted the most attention. Nanotechnology has been fostering excellent prospects in the development of enzymatic biosensors, since enzyme immobilization onto conductive nanostructures can improve characteristics that are crucial in biosensor transduction, such as surface-to-volume ratio, signal response, selectivity, sensitivity, conductivity, and biocatalytic activity, among others. These and other advantages of nanomaterial-based enzymatic biosensors are discussed in this work via the compilation of several reports on their applications in different industrial segments. To provide detailed insights into the state of the art of this technology, all the relevant concepts around the topic are discussed, including the properties of enzymes, the mechanisms involved in their immobilization, and the application of different enzyme-derived biosensors and nanomaterials. Finally, there is a discussion around the pressing challenges in this technology, which will be useful for guiding the development of future research in the area.

Response time of nanostructured relative humidity sensors

2009 ◽  
Vol 140 (2) ◽  
pp. 610-615 ◽  
Author(s):  
J.J. Steele ◽  
M.T. Taschuk ◽  
M.J. Brett
Keyword(s):  
Relative Humidity ◽  
Response Time ◽  
Humidity Sensors

Synthesis and conductive performance of quaternary heteropoly acid H5SiW9Mo2VO40⋅13H2O

2018 ◽  
Vol 11 (04) ◽  
pp. 1850065 ◽  
Author(s):  
Zhirong Xie ◽  
Qingyin Wu ◽  
Fengwei He ◽  
Limei Ai
Keyword(s):  
Activation Energy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Relative Humidity ◽  
Proton Conductivity ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Temperature Range ◽  
Higher Temperature ◽  
Conductive Mechanism

A novel molybdenum- and vanadium-substituted quaternary heteropoly acid H5SiW9Mo2VO40[Formula: see text][Formula: see text][Formula: see text]13H2O has been synthesized and characterized by IR, UV, TG-DTA and XRD. The proton conductive performance was studied by the electrochemical impedance spectroscopy (EIS), which demonstrated that H5SiW9Mo2VO40[Formula: see text][Formula: see text][Formula: see text]13H2O shows excellent proton conduction performance with proton conductivity reaching [Formula: see text][Formula: see text]S[Formula: see text]cm[Formula: see text] at 60∘C and 80% relative humidity. In the temperature range of measurements, conductivity enhances with higher temperature. The proton conductive mechanism of this new heteropoly acid is the vehicle mechanism due to the activation energy of 31.91[Formula: see text]kJ [Formula: see text] mol[Formula: see text].

Experimental Techniques in Fracture Characterization

2007 ◽  
Vol 567-568 ◽  
pp. 39-44
Author(s):  
W. R. Tyson
Keyword(s):  
Fracture Toughness ◽  
State Of The Art ◽  
Research Trends ◽  
The State ◽  
Experimental Techniques ◽  
Fracture Characterization ◽  
Girth Welds ◽  
Linepipe Steel

Characterization of fracture toughness is discussed in relation to specification of steels for northern pipelines. The state of the art and research trends in measurement of CTOD for girth welds and CTOA for linepipe steel are described.

scholarly journals Heterogeneous photocatalysts: an overview of classic and modern approaches for optical, electronic, and charge dynamics evaluation

2019 ◽  
Vol 48 (5) ◽  
pp. 1255-1271 ◽  
Author(s):  
Hui Ling Tan ◽  
Fatwa F. Abdi ◽  
Yun Hau Ng
Keyword(s):  
State Of The Art ◽  
The State ◽  
Experimental Techniques ◽  
Charge Dynamics ◽  
Key Aspects

This review summarizes current experimental techniques, including the conventional and the state-of-the-art tools, to examine the key aspects of photocatalysts.

Development of Humidity Sensors using Layer-by-Layer nanoAssembly of Polypyrrole

2005 ◽  
Vol 872 ◽  
Author(s):  
R. Nohria ◽  
Y. Su ◽  
R.K. Khillan ◽  
R. Dikshit ◽  
Y. Lvov ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Response Time ◽  
Sheet Resistance ◽  
Fast Response ◽  
Layer By Layer ◽  
Humidity Sensors ◽  
Intended Application ◽  
Humidity Sensitivity

AbstractIn this paper we demonstrate high sensitive and fast response humidity sensors using layer-by-layer (LbL) nano-assembled films of Polypyrrole (PPY). Spin coated PPY films were used for sensitivity and response time comparisons. The change in electrical sheet resistance of the sensing films was monitored as the device was exposed to humidity. For 5% change in relative humidity sensitivity measured from layer-by-layer based devices was 10% and 8% for the spin coated devices. The response time for LbL based and spin coated device was measured as 25 seconds and 57 seconds respectively. The LbL nano-assembled films of PPY showed the better response in terms of sensitivity, response time, linearity and degradation. An intended application for these LbL nano-assembled devices is in disposable handheld instruments to monitor the presence of humidity in humidity sensitive environments.

Practical Picture Processing

1974 ◽  
Vol 32 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Radiation Damage ◽  
Coherence Length ◽  
Spatial Information ◽  
State Of The Art ◽  
Coherent Radiation ◽  
The State ◽  
Energy Spread ◽  
Electron Micrograph ◽  
Picture Processing ◽  
Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

Hypothesis-Evidence Coordination: The State of the Art

2003 ◽  
Vol 48 (6) ◽  
pp. 826-829 ◽  
Author(s):  
Eric Amsel
Keyword(s):  
State Of The Art ◽  
The State

The State of the Art

1968 ◽  
Vol 13 (9) ◽  
pp. 479-480
Author(s):  
LEWIS PETRINOVICH
Keyword(s):  
State Of The Art ◽  
The State
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