scholarly journals Methanol-Sensing Property Improvement of Mesostructured Zinc Oxide Prepared by the Nanocasting Strategy

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Qian Gao ◽  
Wei-Tao Zheng ◽  
Cun-Di Wei ◽  
Hui-Ming Lin
Keyword(s):  
Operating Temperature ◽  
Critical Role ◽  
Ethanol Sensitivity ◽  
Intrinsic Properties ◽  
Structure And Morphology ◽  
Methanol Sensor ◽  
Replication Procedure ◽  
Higher Sensitivity ◽  
Sensing Performance ◽  
Resultant Material

The specific structure and morphology often play a critical role in governing the excellent intrinsic properties of the compound semiconductor. Herein, mesostructured ZnO with excellent methanol-sensing properties was prepared by a structure replication procedure through the incipient wetness technique. The investigation on the crystal structure and morphology of the resultant material shows that the product consists of hexagonally arranged mesopores and crystalline walls, and its structure is an ideal replication of CMK-3 template. Consequently, mesostructured ZnO was fabricated as a gas sensor for methanol. The excellent methanol-sensing performance was achieved at a relatively low operating temperature of 120°C. In comparison with the nonporous ZnO prepared through conventional coprecipitation approach, mesostructured ZnO material shows the higher sensitivity and stability. Furthermore, it shows the discrimination between methanol and ethanol sensitivity, which makes it a good candidate in fabricating selective methanol sensor in practice.

scholarly journals Low-Operating-Temperature NO2 Sensor Based on a CeO2/ZnO Heterojunction

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8269
Author(s):  
Kai Sun ◽  
Guanghui Zhan ◽  
Hande Chen ◽  
Shiwei Lin
Keyword(s):  
Hydrothermal Treatment ◽  
Room Temperature ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Nanorod Array ◽  
Gas Sensitivity ◽  
Anodic Electrodeposition ◽  
No2 Sensor ◽  
Higher Sensitivity ◽  
Sensing Performance

CeO2/ZnO-heterojunction-nanorod-array-based chemiresistive sensors were studied for their low-operating-temperature and gas-detecting characteristics. Arrays of CeO2/ZnO heterojunction nanorods were synthesized using anodic electrodeposition coating followed by hydrothermal treatment. The sensor based on this CeO2/ZnO heterojunction demonstrated a much higher sensitivity to NO2 at a low operating temperature (120 °C) than the pure-ZnO-based sensor. Moreover, even at room temperature (RT, 25 °C) the CeO2/ZnO-heterojunction-based sensor responds linearly and rapidly to NO2. This sensor’s reaction to interfering gases was substantially less than that of NO2, suggesting exceptional selectivity. Experimental results revealed that the enhanced gas-sensing performance at the low operating temperature of the CeO2/ZnO heterojunction due to the built-in field formed after the construction of heterojunctions provides additional carriers for ZnO. Thanks to more carriers in the ZnO conduction band, more oxygen and target gases can be adsorbed. This explains the enhanced gas sensitivity of the CeO2/ZnO heterojunction at low operating temperatures.

scholarly journals Untangling the environmental from the dietary: dust does not matter

2016 ◽  
Vol 283 (1838) ◽  
pp. 20161032 ◽  
Author(s):  
Gildas Merceron ◽  
Anusha Ramdarshan ◽  
Cécile Blondel ◽  
Jean-Renaud Boisserie ◽  
Noël Brunetiere ◽  
...  
Keyword(s):  
Critical Role ◽  
Tooth Wear ◽  
Textural Analysis ◽  
Significant Determinant ◽  
Intrinsic Properties ◽  
Dental Microwear ◽  
Natural Conditions ◽  
Evolutionary Mechanisms ◽  
Food Items ◽  
Selection Of

Both dust and silica phytoliths have been shown to contribute to reducing tooth volume during chewing. However, the way and the extent to which they individually contribute to tooth wear in natural conditions is unknown. There is still debate as to whether dental microwear represents a dietary or an environmental signal, with far-reaching implications on evolutionary mechanisms that promote dental phenotypes, such as molar hypsodonty in ruminants, molar lengthening in suids or enamel thickening in human ancestors. By combining controlled-food trials simulating natural conditions and dental microwear textural analysis on sheep, we show that the presence of dust on food items does not overwhelm the dietary signal. Our dataset explores variations in dental microwear textures between ewes fed on dust-free and dust-laden grass or browse fodders. Browsing diets with a dust supplement simulating Harmattan windswept environments contain more silica than dust-free grazing diets. Yet browsers given a dust supplement differ from dust-free grazers. Regardless of the presence or the absence of dust, sheep with different diets yield significantly different dental microwear textures. Dust appears a less significant determinant of dental microwear signatures than the intrinsic properties of ingested foods, implying that diet plays a critical role in driving the natural selection of dental innovations.

scholarly journals Acetone Sensing and Catalytic Conversion by Pd-Loaded SnO2

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5921
Author(s):  
Pascal M. Gschwend ◽  
Florian M. Schenk ◽  
Alexander Gogos ◽  
Sotiris E. Pratsinis
Keyword(s):  
Gas Sensors ◽  
Tin Oxide ◽  
Operating Temperature ◽  
Packed Bed ◽  
Sensor Performance ◽  
Response Recovery ◽  
Recovery Times ◽  
Metal Additives ◽  
Metal Oxide Gas Sensors ◽  
Sensing Performance

Noble metal additives are widely used to improve the performance of metal oxide gas sensors, most prominently with palladium on tin oxide. Here, we photodeposit different quantities of Pd (0–3 mol%) onto nanostructured SnO2 and determine their effect on sensing acetone, a critical tracer of lipolysis by breath analysis. We focus on understanding the effect of operating temperature on acetone sensing performance (sensitivity and response/recovery times) and its relationship to catalytic oxidation of acetone through a packed bed of such Pd-loaded SnO2. The addition of Pd can either boost or deteriorate the sensing performance, depending on its loading and operating temperature. The sensor performance is optimal at Pd loadings of less than 0.2 mol% and operating temperatures of 200–262.5 °C, where acetone conversion is around 50%.

scholarly journals Postsynaptic integrative properties of dorsal CA1 pyramidal neuron subpopulations

2020 ◽  
Vol 123 (3) ◽  
pp. 980-992
Author(s):  
Arjun V. Masurkar ◽  
Chengju Tian ◽  
Richard Warren ◽  
Isabel Reyes ◽  
Daniel C. Lowes ◽  
...  
Keyword(s):  
Synaptic Input ◽  
Pyramidal Neuron ◽  
Critical Role ◽  
Functional Specialization ◽  
Intrinsic Properties ◽  
Transverse Axis ◽  
Population Activity ◽  
Sequence Encoding ◽  
Ca1 Pyramidal Neuron ◽  
Radial Axis

The population activity of CA1 pyramidal neurons (PNs) segregates along anatomical axes with different behaviors, suggesting that CA1 PNs are functionally subspecialized based on somatic location. In dorsal CA1, spatial encoding is biased toward CA2 (CA1c) and in deep layers of the radial axis. In contrast, nonspatial coding peaks toward subiculum (CA1a) and in superficial layers. While preferential innervation by spatial vs. nonspatial input from entorhinal cortex (EC) may contribute to this specialization, it cannot fully explain the range of in vivo responses. Differences in intrinsic properties thus may play a critical role in modulating such synaptic input differences. In this study we examined the postsynaptic integrative properties of dorsal CA1 PNs in six subpopulations along the transverse (CA1c, CA1b, CA1a) and radial (deep, superficial) axes. Our results suggest that active and passive properties of deep and superficial neurons evolve over the transverse axis to promote the functional specialization of CA1c vs. CA1a as dictated by their cortical input. We also find that CA1b is not merely an intermediate mix of its neighbors, but uniquely balances low excitability with superior input integration of its mixed input, as may be required for its proposed role in sequence encoding. Thus synaptic input and intrinsic properties combine to functionally compartmentalize CA1 processing into at least three transverse axis regions defined by the processing schemes of their composite radial axis subpopulations. NEW & NOTEWORTHY There is increasing interest in CA1 pyramidal neuron heterogeneity and the functional relevance of this diversity. We find that active and passive properties evolve over the transverse and radial axes in dorsal CA1 to promote the functional specialization of CA1c and CA1a for spatial and nonspatial memory, respectively. Furthermore, CA1b is not a mean of its neighbors, but features low excitability and superior integrative capabilities, relevant to its role in nonspatial sequence encoding.

Development of Advanced TBC for 1650 °C Class Gas Turbine

2021 ◽  
Author(s):  
Yoshifumi Okajima ◽  
Taiji Torigoe ◽  
Masahiko Mega ◽  
Masamitsu Kuwabara ◽  
Naotoshi Okaya
Keyword(s):  
Gas Turbine ◽  
Thermal Barrier Coatings ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Operating Temperature ◽  
Critical Role ◽  
Thermal Barrier ◽  
Barrier Coatings

Abstract Increasing operating temperature plays a critical role in improving the thermal efficiency of gas turbines. This paper assesses the capability of advanced thermal barrier coatings being developed for use in 1700 °C class gas turbines. Parts sprayed with these coatings were evaluated and found to have excellent durability and long-term reliability.

CO gas sensing performance of electrospun Co3O4 nanostructures at low operating temperature

2020 ◽  
Vol 303 ◽  
pp. 127193 ◽  
Author(s):  
C. Busacca ◽  
A. Donato ◽  
M. Lo Faro ◽  
A. Malara ◽  
G. Neri ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Operating Temperature ◽  
Co3o4 Nanostructures ◽  
Sensing Performance ◽  
Co Gas

The xylene sensing performance of WO3 decorated anatase TiO2 nanoparticles as a sensing material for a gas sensor at a low operating temperature

RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 49692-49701 ◽  
Author(s):  
Nan Chen ◽  
Dongyang Deng ◽  
Yuxiu Li ◽  
Xinxin Xing ◽  
Xu Liu ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Operating Temperature ◽  
Anatase Tio2 ◽  
Sensing Material ◽  
One Step ◽  
Sensing Performance

Here, the pristine and WO3 decorated TiO2 nanoparticles were synthesized by a one-step hydrothermal without the use of a surfactant or template, and used to fabricate gas sensors.

Glycothermal Synthesis of VO2(B) Nanoparticles for Gas Sensing Application

2020 ◽  
Vol 20 (3) ◽  
pp. 1946-1954 ◽  
Author(s):  
Hongmei Zhu ◽  
Zhengjie Zhang ◽  
Xuchuan Jiang
Keyword(s):  
Vanadium Dioxide ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Environmental Safety ◽  
Vanadium Oxides ◽  
Good Sensitivity ◽  
Reaction Conditions ◽  
The Family ◽  
Sensing Application ◽  
Sensing Performance

This study represents a facile but efficient glycothermal method for synthesis of vanadium dioxide, VO2(B) nanoparticles with various geometries from spheres to rods, flakes or their agglomeration structures, by controlling reaction conditions (e.g., vanadium resources, reducing agents and surfactants). The as-prepared VO2(B) nanoparticles were characterized in microstructure and composition, and also examined in terms of gas sensing performance. It was found that the VO2(B) nanoparticles exhibit a good sensitivity towards alcohols (ethanol, isopropanol, and butanol) and acetone at the optimised operating temperature of 300 °C. The gas sensing performance was further compared with other vanadium oxides investigated previously, such as V2O5, Na1.08V3O8. The plausible gas sensing mechanism of the as-prepared nanoparticles was discussed in detail. This study would expand the family of vanadium oxides that can be made as potential sensors for applications in detecting environmental safety and human health.

scholarly journals Cu/CuO@ZnO Hollow Nanofiber Gas Sensor: Effect of Hollow Nanofiber Structure and P–N Junction on Operating Temperature and Sensitivity

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3151 ◽  
Author(s):  
Sung-Ho Hwang ◽  
Young Kwang Kim ◽  
Seong Hui Hong ◽  
Sang Kyoo Lim
Keyword(s):  
Gas Sensor ◽  
Low Temperatures ◽  
Operating Temperature ◽  
Hollow Structure ◽  
Working Temperature ◽  
Sensor Effect ◽  
Co Gas Sensor ◽  
Hollow Nanofiber ◽  
Higher Sensitivity ◽  
Co Gas

For the fast and easy detection of carbon monoxide (CO) gas, it was necessary to develop a CO gas sensor to operate in low temperatures. Herein, a novel Cu/CuO-decorated ZnO hollow nanofiber was prepared with the electrospinning, calcination, and photodeposition methods. In the presence of 100 ppm CO gas, the Cu/CuO-photodeposited ZnO hollow nanofiber (Cu/CuO@ZnO HNF) showed twice higher sensitivity than that of pure ZnO nanofiber at a relatively low working temperature of 300 °C. The hollow structure and p–n junction between Cu/CuO and ZnO would be considered to contribute to the enhancement of sensitivity to CO gas at 300 °C due to the improved specific surface area and efficient electron transfer.

scholarly journals Acetone Gas Sensing Properties of a Multiple-Networked Fe2O3-Functionalized CuO Nanorod Sensor

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Sunghoon Park ◽  
Hyejoon Kheel ◽  
Gun-Joo Sun ◽  
Taegyung Ko ◽  
Wan In Lee ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Optimal Operating ◽  
Sensing Properties ◽  
Adsorption Sites ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Cuo Nanorods ◽  
Sensing Performance

Fe2O3-decorated CuO nanorods were prepared by Cu thermal oxidation followed by Fe2O3decoration via a solvothermal route. The acetone gas sensing properties of multiple-networked pristine and Fe2O3-decorated CuO nanorod sensors were examined. The optimal operating temperature of the sensors was found to be 240°C. The pristine and Fe2O3-decorated CuO nanorod sensors showed responses of 586 and 1,090%, respectively, to 1,000 ppm of acetone at 240°C. The Fe2O3-decorated CuO nanorod sensor also showed faster response and recovery than the latter sensor. The acetone gas sensing mechanism of the Fe2O3-decorated CuO nanorod sensor is discussed in detail. The origin of the enhanced sensing performance of the multiple-networked Fe2O3-decorated CuO nanorod sensor to acetone gas was explained by modulation of the potential barrier at the Fe2O3-CuO interface, highly catalytic activity of Fe2O3for acetone oxidation, and the creation of active adsorption sites by Fe2O3nanoparticles.

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