The Stability of Chromium in CrAPO-5, CrAPO-11, and CrS-1 during Liquid Phase Oxidations

1998 ◽  
Vol 175 (1) ◽  
pp. 62-69 ◽  
Author(s):  
H.E.B. Lempers ◽  
R.A. Sheldon
Keyword(s):  
Liquid Phase ◽  
The Stability

scholarly journals Catalytic Performance of Nitrogen-Doped Activated Carbon Supported Pd Catalyst for Hydrodechlorination of 2,4-Dichlorophenol or Chloropentafluoroethane

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 674 ◽  
Author(s):  
Haodong Tang ◽  
Bin Xu ◽  
Meng Xiang ◽  
Xinxin Chen ◽  
Yao Wang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Liquid Phase ◽  
Gas Phase ◽  
Nitrogen Doping ◽  
Catalyst Surface ◽  
Catalytic Performance ◽  
Atomic Ratio ◽  
Pd Catalyst ◽  
Nitrogen Doped ◽  
The Stability

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.

Insights into the stability and thermal properties of WSe2-based nanofluids for concentrating solar power prepared by liquid phase exfoliation

2020 ◽  
Vol 319 ◽  
pp. 114333
Author(s):  
Paloma Martínez-Merino ◽  
Antonio Sánchez-Coronilla ◽  
Rodrigo Alcántara ◽  
Elisa I. Martín ◽  
Javier Navas
Keyword(s):  
Thermal Properties ◽  
Liquid Phase ◽  
Solar Power ◽  
Concentrating Solar Power ◽  
Liquid Phase Exfoliation ◽  
The Stability

scholarly journals Study on Liquid Phase Hydrogenation Technology of White Oil

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Tiezhen Zhang ◽  
◽  
Famin Sun ◽  
Yungang Jia ◽  
Fangming Xie ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Raw Materials ◽  
Copper Plate ◽  
Simulation Software ◽  
Quality Requirements ◽  
Food Grade ◽  
Ultraviolet Absorbance ◽  
Liquid Phase Hydrogenation ◽  
The Stability ◽  
Aromatic Hydrogen

Using Aspen Plus simulation software to simulate the hydrogen solubility of white oil raw materials, and calculate the de-aromatic hydrogen consumption. The liquid hydrogenation technology of white oil was studied by using 100mL uplink liquid hydrogenation evaluation device. The research results show that the ultraviolet absorbance of the liquid phase hydrogenation product is no more than 0.1, and saybolt color, copper plate corrosion, readily carbonizable substance can meet the quality requirements under the conditions of 230℃, 17 Mpa and LHSV 0.5 h-1. 2000 hours liquid phase hydrogenation test shows the stability of product quality which meets the food grade standard, and the liquid phase hydrogenation technology is feasible.

scholarly journals Regulation of the Stability and Localization of Post-synaptic Membrane Proteins by Liquid-Liquid Phase Separation

2021 ◽  
Vol 12 ◽  
Author(s):  
Tomohisa Hosokawa ◽  
Pin-Wu Liu
Keyword(s):  
Synaptic Plasticity ◽  
Phase Separation ◽  
Liquid Phase ◽  
Synaptic Transmission ◽  
Molecular Mechanism ◽  
Postsynaptic Membrane ◽  
Liquid Phase Separation ◽  
Synaptic Membrane ◽  
The Stability ◽  
Liquid Liquid Phase Separation

Synaptic plasticity is a cellular mechanism of learning and memory. The synaptic strength can be persistently upregulated or downregulated to update the information sent to the neuronal network and form a memory engram. For its molecular mechanism, the stability of α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate-type glutamate receptor (AMPAR), a glutamatergic ionotropic receptor, on the postsynaptic membrane has been studied for these two decades. Since AMPAR is not saturated on the postsynaptic membrane during a single event of neurotransmitter release, the number and nanoscale localization of AMPAR is critical for regulating the efficacy of synaptic transmission. The observation of AMPAR on the postsynaptic membrane by super-resolution microscopy revealed that AMPAR forms a nanodomain that is defined as a stable segregated cluster on the postsynaptic membrane to increase the efficacy of synaptic transmission. Postsynaptic density (PSD), an intracellular protein condensate underneath the postsynaptic membrane, regulates AMPAR dynamics via the intracellular domain of Stargazin, an auxiliary subunit of AMPAR. Recently, it was reported that PSD is organized by liquid-liquid phase separation (LLPS) to form liquid-like protein condensates. Furthermore, the calcium signal induced by the learning event triggers the persistent formation of sub-compartments of different protein groups inside protein condensates. This explains the formation of nanodomains via synaptic activation. The liquid-like properties of LLPS protein condensates are ideal for the molecular mechanism of synaptic plasticity. In this review, we summarize the recent progress in the properties and regulation of synaptic plasticity, postsynaptic receptors, PSD, and LLPS.

Ethanol and Distillate Blends: A Thermodynamic Approach to Miscibility Issues

2010 ◽  
Author(s):  
Jean-Noe¨l Jaubert ◽  
Romain Privat ◽  
Michel Molie`re
Keyword(s):  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Functional Groups ◽  
Fossil Fuels ◽  
Chemical Properties ◽  
Physical Property ◽  
Diesel Oil ◽  
Group Contribution ◽  
Heat Of Mixing ◽  
The Stability

In the recent years, the quest for an ever wider cluster of sustainable primary energies has prompted an increasing number of attempts to combine the emission sobriety of bio fuels with the energy density advantage of fossil fuels. A number of compositions incorporating hydrocarbons, ethanol and in some cases limited amounts of water have been proposed, especially in the forms of micro emulsions, with a variable success. Indeed due to markedly different physical and chemical properties, ethanol and gasoil are able to blend and form homogeneous solutions only in limited proportion ranges. Indeed, such mixtures often give rise to liquid-liquid equilibrium. A key parameter is thus the Minimum Miscibility Temperature (MMT), i.e. the temperature above which ethanol and gasoil become completely miscible. In fact, commercial gasoils do not constitute a monolithic product but display in the contrary a large span of compositions that influence the stability of these blends. In this context, the LRGP laboratory (Laboratoire Re´actions et Ge´nie des Proce´de´s) has undertaken an investigation program intended to understand the factors underlying the stability of ethanol/gasoil blends. The approach is based on the calculation of the liquid-liquid phase diagrams formed by anhydrous ethanol and a mixture of various hydrocarbons representative of the diesel oil pool using the group contribution concept. Indeed, for correlating thermodynamic properties, it is often convenient to regard a molecule as an aggregate of functional groups; as a result, some thermodynamic properties (heat of mixing, activity coefficients) can be calculated by summing group contributions. In this study, the universal quasichemical functional group activity coefficient (UNIFAC) method has been employed as it appears to be particularly useful for making reasonable estimates for the studied non ideal mixtures for which data are sparse or totally absent. In any group-contribution method, the basic idea is that whereas there are thousands of chemical compounds of interest in chemical technology, the number of functional groups that constitute these compounds is much smaller. Therefore, if we assume that a physical property of a fluid is the sum of contributions made by the molecule’s functional groups, we obtain a possible technique for correlating the properties of a very large number of fluids in terms of a much smaller number of parameters that characterize the contributions of individual groups. This paper shows the large influence exerted by the paraffinic, aromatic and naphthenic character of the gasoil but also the sulfur content of the fossil fraction on the shape of the liquid-liquid phase diagram and on the value of the minimum miscibility temperature.

Germanium Partitioning and Interface Stability During Rapid Solidification of Gesi Alloys

1994 ◽  
Vol 354 ◽  
Author(s):  
D. P. Brunco ◽  
Michael O. Thompson ◽  
D. E. Hoglundt ◽  
M. J. Aziz
Keyword(s):  
Liquid Phase ◽  
Rapid Solidification ◽  
Growth Rates ◽  
Laser Processing ◽  
Partition Coefficients ◽  
Processing Time ◽  
Measured Velocity ◽  
Continuous Growth ◽  
Stability Model ◽  
The Stability

AbstractThe stability of laser processed GeSi heteroepitaxial alloys on Si to partitioning driven interface instabilities is examined. Existing stability models are extended to include nonequi-librium solidification effects for nondilute alloys and are examined under typical conditions of laser induced solidification. Ge diffusion and partitioning were measured for quantitative input to the models. The Ge liquid-phase diffusivity was determined to be 2.5 x 10-4 cm2/s. The measured velocity-dependent partition coefficients k(v) were fit to the Continuous Growth Model using an equilibrium k of 0.45 and a diffusive speed of 2.7 m/s. Stability calculations based on these values and our extended stability model are presented. Although instabilities at compositions comparable to those experimentally observed to give defective films are predicted, the growth rates of these instabilities appear too slow to destabilize an interface on laser processing time scales. These results suggest that strain or other effects play an important role in the observed defective microstructures.

POLYSACCHARIDE DEGRADING ENZYMES IN MICROBIAL POPULATIONS FROM THE LIQUID AND SOLID FRACTIONS OF BOVINE RUMEN DIGESTA

1984 ◽  
Vol 64 (5) ◽  
pp. 58-59 ◽  
Author(s):  
A. G. WILLIAMS ◽  
N. H. STRACHAN
Keyword(s):  
Liquid Phase ◽  
Key Words ◽  
Glycoside Hydrolase ◽  
Microbial Populations ◽  
Bovine Rumen ◽  
Degrading Enzymes ◽  
The Stability

Polysaccharide depolymerase and glycoside hydrolase enzymes involved in the degradation of plant structural polysaccharides were most active in the adherent particle-associated microorganisms, whereas soluble saccharides were metabolized by the liquid phase and nonadherent populations. The activities were constant confirming the stability of the populations. Key words: Polysaccharidase, glycosidase, particle-associated microorganisms

Paper 33: Liquid Phase Movement in the Last Stages of Large Condensing Steam Turbines

1969 ◽  
Vol 184 (7) ◽  
pp. 70-91 ◽  
Author(s):  
J. Valha
Keyword(s):  
Liquid Phase ◽  
Droplet Size ◽  
Liquid Films ◽  
Steam Turbines ◽  
Blade Surface ◽  
Spontaneous Condensation ◽  
Primary Droplet ◽  
The Stability ◽  
Phase Transport ◽  
Thermodynamic Instability

This paper deals with the generation and the movement of the liquid phase in the last stages of large condensing steam turbines. Considering thermodynamic instability, the primary droplet size resulting from spontaneous condensation is dependent on radial position, the flow, and inlet parameters. The analysis of the liquid phase transport to the blade surface is given, and the stability and disintegration of the liquid films on the blade surface is discussed.

Sign in / Sign up

Export Citation Format

Share Document