PHOTOCATALYTIC CONVERSION OF METHANE INTO METHANOL OVER THE MoO3(010) SURFACE USING A SIMULATION METHOD

2004 ◽  
Vol 11 (01) ◽  
pp. 33-39 ◽  
Author(s):  
A. Z. MOSHFEGH ◽  
M. DASHTI
Keyword(s):  
Light Intensity ◽  
Atmospheric Pressure ◽  
Incident Light ◽  
Formation Rate ◽  
Simulation Method ◽  
Incident Light Intensity ◽  
Formation Reaction ◽  
Methanol Formation ◽  
Conversion Of Methane ◽  
Effect Of Light

In this investigation, we have studied the kinetics and mechanism of photocatalytic conversion of methane into methanol reaction over the MoO 3(010) surface using a computer simulation method. Methane and oxygen as the reactants are used at room temperature and atmospheric pressure under UV photoirradiation of the catalyst. According to our data analysis, the order of methanol formation reaction with respect to CH 4 and O 2 was determined to be l=0.30 and m=-1.03, respectively. The highest methanol formation rate (TOF) value was obtained at about 0.05 molecule/s.site in a range of 25–35 W/cm2 incident light intensity with energy hν≥Eg. The selectivity of CH 3 OH was increased with increasing partial pressure of CH 4, while the selectivity of CHOH was decreased. The effect of light intensity on the CH 3 OH selectivity was also studied under different P CH 4/P O 2 ratios, namely 0.9, 1.5 and 2.6. The highest CH 3 OH selectivity was obtained at 1.5 ratio.

scholarly journals The photosynthesis of hydrogen chloride. III.—Mixtures containing oxygen

1933 ◽  
Vol 140 (842) ◽  
pp. 713-740 ◽  
Keyword(s):  
Light Intensity ◽  
Hydrogen Chloride ◽  
Oxygen Content ◽  
Quantum Efficiency ◽  
Atmospheric Pressure ◽  
Incident Light ◽  
Incident Light Intensity ◽  
Inhibiting Action ◽  
Rate Of Reaction

The inhibiting action of oxygen in hydrogen-chlorine mixtures was first observed by Bunsen and Roscoe, and has been generally confirmed by all later workers, but the exact part played by oxygen is still attended by some uncertainties. Chapman and MacMahon found the sensitivity of stoichiometric mixtures of hydrogen and chlorine at atmospheric pressure to be inversely proportional to the oxygen content. In like manner, Bodenstein and Dux, for stoichiometric mixtures and concentrations of oxygen up to 22.5 mm. Hg, state that the rate of formation of HCI under such conditions is given by d [HCI] / dt = k [Cl 2 ] 2 / [O 2 ] for constant conditions of incident light intensity. The results of all workers are in agreement with the statement that in the presence of oxygen the rate of reaction is proportional to the first power of the light absorbed, and thus that the quantum efficiency is independent of variation of the intensity of light.

scholarly journals All organic multiferroic magnetoelectric complexes with strong interfacial spin-dipole interaction

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuying Yang ◽  
Zhiyan Chen ◽  
Xiangqian Lu ◽  
Xiaotao Hao ◽  
Wei Qin
Keyword(s):  
Magnetic Field ◽  
Light Intensity ◽  
Room Temperature ◽  
Incident Light ◽  
Dipole Interaction ◽  
Interfacial Interaction ◽  
Magnetoelectric Coupling ◽  
Incident Light Intensity ◽  
Organic Ferromagnets ◽  
Magnetoelectric Coefficient

AbstractThe organic magnetoelectric complexes are beneficial for the development on flexible magnetoelectric devices in the future. In this work, we fabricated all organic multiferroic ferromagnetic/ferroelectric complexes to study magnetoelectric coupling at room temperature. Under the stimulus of external magnetic field, the localization of charge inside organic ferromagnets will be enhanced to affect spin–dipole interaction at organic multiferroic interfaces, where overall ferroelectric polarization is tuned to present an organic magnetoelectric coupling. Moreover, the magnetoelectric coupling of the organic ferromagnetic/ferroelectric complex is tightly dependent on incident light intensity. Decreasing light intensity, the dominated interfacial interaction will switch from spin–dipole to dipole–dipole interaction, which leads to the magnetoelectric coefficient changing from positive to negative in organic multiferroic magnetoelectric complexes.

A renewable photocatalytic system with dramatic photocatalytic activity for H2 evolution and constant light energy utilization: Eosin Y sensitized ZnWO4 nanoplates loaded with CuO nanoparticles

2021 ◽  
Author(s):  
Xiaoluo Bao ◽  
Xiaokun Wang ◽  
Xiangqing Li ◽  
Lixia Qin ◽  
Taiyang Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Light Intensity ◽  
Incident Light ◽  
Cuo Nanoparticles ◽  
Energy Utilization ◽  
Limited Attention ◽  
Eosin Y ◽  
H2 Evolution ◽  
Incident Light Intensity ◽  
Photocatalytic System

It is necessary for the commercialization of sunlight-driven H2 evolution to develop an efficient photocatalytic system whose energy utilization is independent on incident light intensity. Unfortunately, limited attention has been...

scholarly journals Temperature and Light-Quality-Dependent Regulation of Freezing Tolerance in Barley

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 83 ◽  
Author(s):  
Mohamed Ahres ◽  
Krisztián Gierczik ◽  
Ákos Boldizsár ◽  
Pavel Vítámvás ◽  
Gábor Galiba
Keyword(s):  
Light Intensity ◽  
Target Gene ◽  
Light Quality ◽  
Incident Light ◽  
Gene Expression Pattern ◽  
Frost Tolerance ◽  
Light Conditions ◽  
Incident Light Intensity ◽  
Binding Factor ◽  
R:Fr Ratio

It is established that, besides the cold, incident light also has a crucial role in the cold acclimation process. To elucidate the interaction between these two external hardening factors, barley plantlets were grown under different light conditions with low, normal, and high light intensities at 5 and 15 °C. The expression of the HvCBF14 gene and two well-characterized members of the C-repeat binding factor (CBF)-regulon HvCOR14b and HvDHN5 were studied. In general, the expression level of the studied genes was several fold higher at 5 °C than that at 15 °C independently of the applied light intensity or the spectra. The complementary far-red (FR) illumination induced the expression of HvCBF14 and also its target gene HvCOR14b at both temperatures. However, this supplementation did not affect significantly the expression of HvDHN5. To test the physiological effects of these changes in environmental conditions, freezing tests were also performed. In all the cases, we found that the reduced R:FR ratio increased the frost tolerance of barley at every incident light intensity. These results show that the combined effects of cold, light intensity, and the modification of the R:FR light ratio can greatly influence the gene expression pattern of the plants, which can result in increased plant frost tolerance.

A multitrap model for high-intensity reciprocity failure in the photographic grain

1984 ◽  
Vol 21 (03) ◽  
pp. 464-478
Author(s):  
William J. Anderson
Keyword(s):  
Light Intensity ◽  
High Intensity ◽  
Extreme Values ◽  
Incident Light ◽  
Time Interval ◽  
Interval Duration ◽  
Incident Light Intensity ◽  
Deterministic Process ◽  
Reciprocity Law ◽  
Reciprocity Failure

The response of the photographic grain to light is a non-deterministic process which is as yet not completely understood. This response, as measured by the photographic density, is usually taken to be a function of the product of incident light intensity and exposure time interval duration, but at extreme values of either of these two quantities, this is no longer true. This latter effect is called reciprocity-law failure. This paper discusses a probabilistic model, similar to a multiserver queue, for high-intensity reciprocity failure.

Sign in / Sign up

Export Citation Format

Share Document