Integrated adsorption and photocatalytic degradation of VOCs using a TiO2/diatomite composite: effects of relative humidity and reaction atmosphere

2020 ◽  
Vol 10 (8) ◽  
pp. 2378-2388 ◽  
Author(s):  
Guangxin Zhang ◽  
Arman Peyravi ◽  
Zaher Hashisho ◽  
Zhiming Sun ◽  
Yangyu Liu ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Photocatalytic Degradation ◽  
Carbon Chain ◽  
Humidity Condition ◽  
Relative Humidity Condition ◽  
Reaction Atmosphere

The optimal relative humidity condition for VOC degradation is related to the length of the carbon chain of VOCs.

The Effect of Local Hydration Environment on the Mechanical Properties and Unloaded Temporal Changes of Isolated Porcine Annular Samples

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Kristina M. Gruevski ◽  
Chad E. Gooyers ◽  
Thomas Karakolis ◽  
Jack P. Callaghan
Keyword(s):  
Relative Humidity ◽  
Annulus Fibrosus ◽  
Circumferential Stress ◽  
Tensile Loading ◽  
Average Standard Deviation ◽  
Relative Humidity Condition ◽  
Test Conditions ◽  
Biaxial Tensile ◽  
Cycle 24

Preventing dehydration during in vitro testing of isolated layers of annulus fibrosus tissue may require different test conditions than functional spine units. The purpose of the study was twofold: (A) to quantify changes in mass and thickness of multilayer annulus samples in four hydration environments over 120 min; and (B) to quantify cycle-varying biaxial tensile properties of annulus samples in the four environments. The environments included a saline bath, air, relative humidity control, and misting combined with controlled humidity. The loading protocol implemented 24 cycles of biaxial tensile loading to 20% strain at a rate of 2%/s with 3-, 8-, and 13-min of intermittent rest. Specimen mass increased an average (standard deviation) 72% (11) when immersed for 120 min (p < 0.0001). The air condition and the combined mist and relative humidity conditions reduced mass by 45% (15) and 25% (23), respectively, after 120 min (p < 0.0014). Stress at 16% stretch in the air condition was higher at cycle 18 (18 min of exposure) and cycle 24 (33 min of exposure) compared to all other environments in both the axial and circumferential directions (p < 0.0460). There was no significant change in mass or thickness over time in the relative humidity condition and the change in circumferential stress at 16% stretch between cycles 6 and 24 was a maximum of 0.099 MPa and not statistically significant. Implementation of a controlled relative humidity environment is recommended to maintain hydration of isolated annulus layers during cyclic tensile testing.

scholarly journals Enhanced Photo-Assisted Acetone Gas Sensor and Efficient Photocatalytic Degradation Using Fe-Doped Hexagonal and Monoclinic WO3 Phase−Junction

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 398 ◽  
Author(s):  
Ji-Chao Wang ◽  
Weina Shi ◽  
Xue-Qin Sun ◽  
Fang-Yan Wu ◽  
Yu Li ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Gas Sensors ◽  
Rational Design ◽  
Operating Temperature ◽  
Light Emitting Diode ◽  
Oxygen Adsorption ◽  
Noninvasive Diagnosis ◽  
Exhaled Breath ◽  
Acetone Concentration ◽  
Relative Humidity Condition

The development of WO3-based gas sensors for analysis of acetone in exhaled breath is significant for noninvasive diagnosis of diabetes. A series of Fe-doped hexagonal and monoclinic WO3 phase−junction (Fe−h/m−WO3) sensors were synthesized by the hydrothermal calcination method, and the influences of operating temperature and light irradiation on the response were studied. Under light emitting diode (LED) illumination, Fe−h/m−WO3 exhibited higher responses to acetone than those of the undoped WO3-based sensors at an operating temperature of 260 °C with 90% relative humidity, and good linearity between response and acetone concentration (0.5 to 2.5 ppm) was achieved under the 90% relative humidity condition. Meanwhile, the optimal Fe−h/m−WO3 sensor exhibited high selectivity and stability for a duration of three months. The excellent sensing performance of Fe−h/m−WO3 was attributed to the formation of phase−junction and Fe doping, and these were beneficial for the separation of photon−generated carriers and oxygen adsorption on the WO3 surface, promoting the generation of superoxide radicals, which was demonstrated by electron paramagnetic resonance and photocurrent tests. Additionally, the Fe−doped WO3 phase−junction sample also showed good photocatalytic performance for rhodamine B degradation. This study may provide some insights into rational design of new types of gas sensors and offer an alternative for noninvasive diagnosis of diabetes.

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