The stability of Pd/TS-1 and Pd/silicalite-1 for catalytic oxidation of methane – understanding the role of titanium

2020 ◽  
Vol 10 (4) ◽  
pp. 1193-1204 ◽  
Author(s):  
Hadi Hosseiniamoli ◽  
Adi Setiawan ◽  
Adesoji A. Adesina ◽  
Eric M. Kennedy ◽  
Michael Stockenhuber
Keyword(s):  
Relative Humidity ◽  
Catalytic Oxidation ◽  
Catalytic Combustion ◽  
Methane Emissions ◽  
Oxidation Of Methane ◽  
The Stability

The stability of Pd/TS-1 and Pd/silicalite-1 catalysts was assessed at 400 °C and an approximate relative humidity (RH) of 80% for catalytic combustion of fugitive methane emissions, aiming to understand the role of titanium in the stability of the catalysts.

scholarly journals The role of endophytic methane oxidizing bacteria in submerged <i>Sphagnum</i> in determining methane emissions of Northeastern Siberian tundra

2010 ◽  
Vol 7 (6) ◽  
pp. 8521-8551
Author(s):  
F. J. W. Parmentier ◽  
J. van Huissteden ◽  
N. Kip ◽  
H. J. M. Op den Camp ◽  
M. S. M. Jetten ◽  
...  
Keyword(s):  
Vegetation Type ◽  
Methane Emissions ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Incubation Experiments ◽  
Flux Measurements ◽  
Microbial Analysis ◽  
Global Carbon ◽  
Tundra Ecosystems

Abstract. The behavior of tundra ecosystems is critical in the global carbon cycle due to their wet soils and large stores of carbon. Recently, cooperation was observed between methanotrophic bacteria and submerged Sphagnum, which reduces methane emissions in this type of vegetation and supplies CO2 for photosynthesis to the plant. Although proven in the lab, the differences that exist in methane emissions from inundated vegetation types with or without Sphagnum have not been linked to these bacteria before. To further investigate the importance of these bacteria, chamber flux measurements, microbial analysis and flux modeling were used to show that methane emissions in a submerged Sphagnum/sedge vegetation type were 50% lower compared to an inundated sedge vegetation without Sphagnum. From examining the results of the measurements, incubation experiments and flux modeling, it was found that it is likely that this difference is due to, for a large part, oxidation of methane below the water table by these endophytic bacteria. This result is important when upscaled spatially since oxidation by these bacteria plays a large role in 15% of the net methane emissions, while at the same time they promote photosynthesis of Sphagnum, and thus carbon storage. Future changes in the spread of submerged Sphagnum, in combination with the response of these bacteria to a warmer climate, could be an important factor in predicting future greenhouse gas exchange from tundra.

Role of pressure in homogeneous and/or catalytic oxidation of methane

1994 ◽  
Vol 21 (2-3) ◽  
pp. 527-532 ◽  
Author(s):  
V.I. Vedeneev ◽  
V.S. Arutyunov ◽  
V.Ya. Basevich ◽  
M.Ya. Goldenberg ◽  
M.A. Teitelboim ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Oxidation Of Methane

scholarly journals Probing the Role of a Non-Thermal Plasma (NTP) in the Hybrid NTP Catalytic Oxidation of Methane

2017 ◽  
Vol 56 (32) ◽  
pp. 9351-9355 ◽  
Author(s):  
Emma K Gibson ◽  
Cristina E Stere ◽  
Bronagh Curran-McAteer ◽  
Wilm Jones ◽  
Giannantonio Cibin ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Thermal Plasma ◽  
Oxidation Of Methane ◽  
Non Thermal Plasma

scholarly journals Probing the Role of a Non-Thermal Plasma (NTP) in the Hybrid NTP Catalytic Oxidation of Methane

2017 ◽  
Vol 129 (32) ◽  
pp. 9479-9483 ◽  
Author(s):  
Emma K Gibson ◽  
Cristina E Stere ◽  
Bronagh Curran-McAteer ◽  
Wilm Jones ◽  
Giannantonio Cibin ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Thermal Plasma ◽  
Oxidation Of Methane ◽  
Non Thermal Plasma

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Alkyl Group ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Terminal Alkyne ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
The Stability ◽  
Selective Formation ◽  
Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

LANDSLIDE RISK MANAGEMENT IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR DUE THE DESIGN OF HIGH-SPEED LINE "MOSCOW-KAZAN"

2017 ◽  
Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Models ◽  
Stable State ◽  
Landslide Risk ◽  
Kuibyshev Reservoir ◽  
Stepped Surface ◽  
The Stability ◽  
Landslide Slope ◽  
The Village

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.

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