scholarly journals Development of La Doped Ni/CeO2 for CH4/CO2 Reforming

2018 ◽  
Vol 4 (4) ◽  
pp. 60 ◽  
Author(s):  
Federica Menegazzo ◽  
Cristina Pizzolitto ◽  
Elena Ghedini ◽  
Alessandro Di Michele ◽  
Giuseppe Cruciani ◽  
...  
Keyword(s):  
Effective Interaction ◽  
Active Phase ◽  
Dry Reforming ◽  
Effect Of Temperature ◽  
Incipient Wetness Impregnation ◽  
Co2 Reforming ◽  
Structural Modifications ◽  
The Stability ◽  
Positive Effect ◽  
La Doped

Methane dry reforming (MDR) allows the transformation of carbon dioxide and methane, the two main greenhouse gases, into syngas. Given the high endothermicity of the process, it is necessary to produce a catalytic system that is very active, selective and resistant to coking deactivation; this work focuses on the development of a heterogeneous catalyst based on nickel supported on cerium oxide. Several strategies of synthesis of the catalysts were studied with particular attention to the lanthanum addition methodology. Both supports and catalysts, fresh and used, were deeply characterized by different techniques (N2 physisorption, TPR, XRD, SEM). The effect of temperature on activity and selectivity of the different catalysts was also studied. A positive effect of lanthanum addition is strongly related to the synthetic methodology. Incipient wetness impregnation of lanthanum precursor on an already calcined ceria has led to the best catalytic activity. This behaviour is due to a more effective interaction between nickel and the support, which results in a higher dispersion of the active phase. The structural modifications have led to an improvement of the redox pump of the ceria, reducing the formation of coke during the reaction and improving the stability on time on stream.

Applicability of Instability Index for In vitro Protein Stability Prediction

2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell
Keyword(s):  
Protein Stability ◽  
Caulobacter Crescentus ◽  
Effect Of Temperature ◽  
Instability Index ◽  
Dipeptide Composition ◽  
Experimental Conditions ◽  
The Stability ◽  
Vitro Protein

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.

The effect of temperature and time on the properties of 2D Cs2ZnBr4 perovskite nanocrystals and its application in a Schottky barrier device

2021 ◽  
Author(s):  
Olusola Akinbami ◽  
Grace N Ngubeni ◽  
Francis Otieno ◽  
Rudo Kadzutu-Sithole ◽  
Cebisa Linganiso ◽  
...  
Keyword(s):  
Solar Cell ◽  
Schottky Barrier ◽  
Effect Of Temperature ◽  
Inorganic Perovskite ◽  
Perovskite Nanocrystals ◽  
The Stability ◽  
Barrier Device

2D hybrid perovskites are promising materials for solar cell applications, in particular, cesium based perovskite nanocrystals as they offer the stability that is absent in organic-inorganic perovskite. However, the most...

scholarly journals Role of Mixed Oxides in Hydrogen Production through the Dry Reforming of Methane over Nickel Catalysts Supported on Modified γ-Al2O3

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 157
Author(s):  
Ahmed Sadeq Al-Fatesh ◽  
Mayankkumar Lakshmanbhai Chaudhary ◽  
Anis Hamza Fakeeha ◽  
Ahmed Aidid Ibrahim ◽  
Fahad Al-Mubaddel ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Nickel Catalysts ◽  
H2 Production ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Incipient Wetness Impregnation ◽  
Thermally Stable ◽  
Oxide Systems ◽  
Catalyst Systems ◽  
H2 Yield

H2 production through dry reforming of methane (DRM) is a hot topic amidst growing environmental and atom-economy concerns. Loading Ni-based reducible mixed oxide systems onto a thermally stable support is a reliable approach for obtaining catalysts of good dispersion and high stability. Herein, NiO was dispersed over MOx-modified-γ-Al2O3 (M = Ti, Mo, Si, or W; x = 2 or 3) through incipient wetness impregnation followed by calcination. The obtained catalyst systems were characterized by infrared, ultraviolet–visible, and X-ray photoelectron spectroscopies, and H2 temperature-programmed reduction. The mentioned synthetic procedure afforded the proper nucleation of different NiO-containing mixed oxides and/or interacting-NiO species. With different modifiers, the interaction of NiO with the γ-Al2O3 support was found to change, the Ni2+ environment was reformed exclusively, and the tendency of NiO species to undergo reduction was modified greatly. Catalyst systems 5Ni3MAl (M = Si, W) comprised a variety of species, whereby NiO interacted with the modifier and the support (e.g., NiSiO3, NiAl2O4, and NiWO3). These two catalyst systems displayed equal efficiency, >70% H2 yield at 800 °C, and were thermally stable for up to 420 min on stream. 5Ni3SiAl catalyst regained nearly all its activity during regeneration for up to two cycles.

scholarly journals Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1554
Author(s):  
Chao Liu ◽  
Zhao-Jun Bu ◽  
Azim Mallik ◽  
Yong-Da Chen ◽  
Xue-Feng Hu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Species Interactions ◽  
Laboratory Experiments ◽  
Resource Competition ◽  
Specific Interactions ◽  
Interaction Type ◽  
Negative Effects ◽  
Experiment Data ◽  
The Stability ◽  
Positive Effect

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

SHELL MATERIAL'S PERFORMANCE OF THE MICROCAPSULE FOR ELECTROLYTIC CO-DEPOSITION

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3124-3130 ◽  
Author(s):  
HUI CONG LIU ◽  
XIU QING XU ◽  
WEI PING LI ◽  
YAN HONG GUO ◽  
LI-QUN ZHU
Keyword(s):  
Composite Coating ◽  
Methyl Cellulose ◽  
Water Vapor Permeability ◽  
Core Material ◽  
Vapor Permeability ◽  
Shell Material ◽  
The Core ◽  
Surface Performance ◽  
The Stability ◽  
Positive Effect

The shell material of microcapsules has an important effect on the electrolytic co-deposition behavior, the release of core material and the surface performance of composite coating. This paper discussed the tensile property and the stability of three shell materials including polyvinyl alcohol (PVA), gelatin and methyl cellulose (MC). It is found that these three shell materials have good mechanical strength and flexibility which are favorable to electrolytic co-deposition and stability of microcapsules in composite coating and that MC has well permeability and porosity which has a positive effect on the release of the core material in composite coating. Moreover, the study of the thermal properties and water vapor permeability of the three shell materials showed that their permeability improved with increase of temperature and humidity. In addition, the composite copper coating containing microcapsules with PVA, gelatin or MC as shell material was prepared respectively.

Temperature Dependence of Degradation of Colored Oxo-Biodegradable Low-Density Polyethylene Films under Accelerated Thermal Aging

2017 ◽  
Vol 890 ◽  
pp. 82-85 ◽  
Author(s):  
Reymark D. Maalihan ◽  
Bryan B. Pajarito
Keyword(s):  
Thermal Aging ◽  
Degradation Products ◽  
Low Density Polyethylene ◽  
Effect Of Temperature ◽  
Low Density ◽  
Polyethylene Films ◽  
Hot Air ◽  
Taguchi Design Of Experiments ◽  
Oxidant Concentration ◽  
The Stability

This work reports the effect of temperature on degradation of colored low-density polyethylene (PE) films during thermal aging. Film samples were formulated according to Taguchi design of experiments where colorant, thickness, and pro-oxidant concentration were varied accordingly. Tensile properties of films were monitored with time during heat aging in a hot air oven at 50, 70, and 90 °C. Likewise, surfaces of aged films were analyzed to evaluate the degree of oxidation of PE during thermal aging. The Arrhenius equation was then used to predict the lifetime of PE at an in-use temperature of 30 °C. Results indicate that increasing the temperature reduces the tensile strength and modulus of films. Formation of carbonyl groups as degradation products is also observed at higher temperatures. Consequently, thermal aging at 90 °C offers the highest extent of degradation of exposed films. Regression analysis reveals that white films degrade at a higher rate than yellow and non-colored films. The presence of TiO2 in white films shortens the lifetime of PE while amine stabilizer in yellow films enhances the stability of PE during thermal aging.

scholarly journals Higher Performance of DSSC with Dyes from Cladophora sp. as Mixed Cosensitizer through Synergistic Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Andery Lim ◽  
Noramaliyana Haji Manaf ◽  
Kushan Tennakoon ◽  
R. L. N. Chandrakanthi ◽  
Linda Biaw Leng Lim ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Structural Changes ◽  
Dye Sensitized Solar Cells ◽  
Life Time ◽  
Effect Of Temperature ◽  
Synergistic Activity ◽  
Electron Recombination ◽  
Positive Interaction ◽  
Effective Electron ◽  
The Stability

Chlorophyll and xanthophyll dyes extracted from a single source of filamentous freshwater green algae (Cladophora sp.) were used to sensitize dye sensitized solar cells and their performances were investigated. A more positive interaction is expected as the derived dyes come from a single natural source because they work mutually in nature. Cell sensitized with mixed chlorophyll and xanthophyll showed synergistic activity with improved cell performance of 1.5- to 2-fold higher than that sensitized with any individual dye. The effect of temperature and the stability of these dyes were also investigated. Xanthophyll dye was found to be more stable compared to chlorophyll that is attributed in the ability of xanthophyll to dissipate extra energy via reversible structural changes. Mixing the dyes resulted to an increase in effective electron life time and reduced the process of electron recombination during solar cell operation, hence exhibiting a synergistic effect.

scholarly journals EFFECT OF WEATHERED SURFACE CRUST LAYER ON STABILITY OF MUAR TRIAL EMBANKMENT

2015 ◽  
Vol 76 (2) ◽  
Author(s):  
Ali Sobhanmanesh ◽  
Ramli Nazir ◽  
Nader SaadatkhaH
Keyword(s):  
Deformation Behavior ◽  
Three Dimension ◽  
Crust Layer ◽  
Staged Construction ◽  
Weathered Crust ◽  
Dimension 2 ◽  
Embankment Height ◽  
The Stability ◽  
Positive Effect ◽  
Surface Crust

his paper attempts to evaluate the effect of surface crust layer on the stability and deformation behavior of embankment. A full-scale case history trial embankment constructed on Muar flat in the valley of the Muar River in Malaysia was modeled and analyzed. The Muar trial embankment was simulated in two- and three-dimension (2-D and 3-D) utilizing finite element programs PLAXIS 2-D AND PLAXIS 3-D FOUNDATION, using staged-construction procedure. Sensitivity analysis was performed by varying the thickness of weathered crust layer beneath the embankment fill, i.e., three models of embankment with no surface crust, 1 m surface crust and 2 m surface crust layer. Predictions were made for the vertical and the horizontal displacements of the embankment. Factor of safety for each meter increase in the embankment height was defined until the failure is reached. It is concluded that the bearing capacity of the ground and the deformation behavior of the embankment were sensitive to the thickness of the weathered crust layer. The surface crust layer has a positive effect on the stability of the embankment and consequently reduces the settlement and increases the failure height of the embankment fill up to 37%.

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