A Pronounced Catalytic Activity of an Acidic Cesium Salt of 12-Tungstophosphoric Acid for Ester Decomposition in Solid–liquid System

1990 ◽  
Vol 19 (7) ◽  
pp. 1201-1202 ◽  
Author(s):  
Toshio Okuhara ◽  
Toru Nishimura ◽  
Kazutaka Ohashi ◽  
Makoto Misono
Keyword(s):  
Catalytic Activity ◽  
Liquid System ◽  
Tungstophosphoric Acid ◽  
Cesium Salt ◽  
Solid Liquid

The Use of High Energies Radiations to Characterise Solid-Liquid Systems

2005 ◽  
Vol 498-499 ◽  
pp. 49-54 ◽  
Author(s):  
Fábio de Oliveira Arouca ◽  
João Jorge Ribeiro Damasceno
Keyword(s):  
Gamma Rays ◽  
Constitutive Equations ◽  
Liquid System ◽  
Local Concentration ◽  
High Energies ◽  
Transient Regimes ◽  
Medium Permeability ◽  
Liquid Systems ◽  
And Performance ◽  
Solid Liquid

The behavior of an isothermal and non-reaction solid-liquid system can be model using a mathematical model based on the Mixtures’ Theory of Continuum Mechanics. The knowledge of the constitutive equations of this phenomenon, as pressure on the solids and medium permeability, is very important in the design and performance evaluation of the continuous thickeners or filters. In this work the batch sedimentation phenomena of a kaolin aqueous suspensions was investigated. The technique consists on measuring of the gamma rays attenuation when they cross the physical media as a function of the local concentration at several vertical positions in a reservoir. Using the experimental data and local concentration as a function of the attenuation curve, it is possible to determine the constitutive equations. The results were satisfactory, allowing simulations of this phenomenon for steady and transient regimes in future papers.

Mechanistic modelling of kinetics and mass transfer for a solid–liquid system: Leaching of zinc with ferric iron

2010 ◽  
Vol 65 (15) ◽  
pp. 4460-4471 ◽  
Author(s):  
Tapio Salmi ◽  
Henrik Grénman ◽  
Heidi Bernas ◽  
Johan Wärnå ◽  
Dmitry Yu. Murzin
Keyword(s):  
Mass Transfer ◽  
Ferric Iron ◽  
Liquid System ◽  
Mechanistic Modelling ◽  
Solid Liquid

Facile Synthesis of Polysubstituted Cyclopropanes in a Two-Phase Solid-Liquid System

1992 ◽  
Vol 22 (12) ◽  
pp. 1651-1653 ◽  
Author(s):  
Yan Chaoguo ◽  
Kong Qiangzhi ◽  
Lu Wenxing ◽  
Wu Jitao
Keyword(s):  
Liquid System ◽  
Facile Synthesis ◽  
Two Phase ◽  
Solid Liquid

Moving into Nanotechnology Roles to Mimic and Boost Enzyme Activity

2018 ◽  
pp. 421-440
Author(s):  
Maria Laura Soriano
Keyword(s):  
Enzyme Activity ◽  
Catalytic Activity ◽  
Enzyme Immobilization ◽  
Mesoporous Materials ◽  
Specific Activity ◽  
Artificial Enzymes ◽  
Catalytic Nanoparticles ◽  
Solid Liquid ◽  
By Products ◽  
Insight Into

A new tendency toward the design of artificial enzymes based on nanostructures (nanodots, nanofibers, mesoporous materials) has emerged. On one hand, nanotechnology bestows self-catalytic nanoparticles with a specific activity to achieve efficient reactions with low number of by-products. On other hand, the nanoparticles may behave as nanometric scaffolds for hosting enzymes, promoting their catalytic activity and stability. In this case, enzyme immobilization requires the preservation of the catalytic activity by preventing enzyme unfolding and avoiding its aggregation. These approaches render many other advantages like hosting/storing enzymes in nanotechnological solid, liquid, and gel-like media. This chapter focuses on the most up-to-date approaches to manipulate or mimic enzyme activity based on nanotechnology, and offers examples of their applications in the most promising fields. It also gives new insight into the creation of reusable nanotechnological tools for enzyme storage.

Microstructural Evolution of AZ91D-1.5%Er during Semi-Solid Isothermal Treatment

2012 ◽  
Vol 192-193 ◽  
pp. 238-245 ◽  
Author(s):  
Hong Yu Xu ◽  
Ze Sheng Ji ◽  
Zhen Yu Wang
Keyword(s):  
Microstructural Evolution ◽  
Heating Temperature ◽  
Liquid System ◽  
Isothermal Treatment ◽  
Az91d Magnesium Alloy ◽  
Primary Particles ◽  
Recycling Technology ◽  
Paper Chip ◽  
Semi Solid ◽  
Solid Liquid

In this paper, chip recycling technology combined with SIMA method which is called CR-SIMA method was adopted to prepare semi-solid billets. AZ91D magnesium alloy was refined by Er and its microstructural evolution was investigated during semi-solid isothermal treatment. The results show that Er can improve the feature of cast structure and decrease the grain size. Moreover, the γ-Mg17Al12 phase is well refined and disperses in the α-Mg matrix. A semisolid microstructure with small and spheroidal primary particles can be obtained after partially remelting. With increasing heating temperature, the dissolution of eutectic Mg17Al12 phase first took place, resulting in the primary dendritic grains coarsening into interconnected non-dendritic grains. With heating continuously, the residual interdendritic γ-Mg17Al12 at the edges of the primary grains melted in succession and the primary grains separated into small polygon grains. During the semi-solid isothermal treatment, the amount of liquid increased until the solid-liquid system reached its equilibrium state. At the same time, owing to the decreasing of interfacial energy, the grains gradually spheroidized and began to grow with a further increasing of the holding time.

Nano-MRF: A Material for Damping Application

2013 ◽  
Vol 209 ◽  
pp. 35-38 ◽  
Author(s):  
Kruti Shah ◽  
R.V. Upadhyay ◽  
V.K. Aswal
Keyword(s):  
Magnetic Particles ◽  
Synergetic Effect ◽  
Liquid System ◽  
Carrier Fluid ◽  
Vehicle Suspensions ◽  
Shock Absorbers ◽  
Increasing Temperature ◽  
Robotics Design ◽  
Solid Liquid ◽  
Vibration Dampers

A magnetorheological fluid (MR), a suspension of micron-sized magnetic particles in a carrier fluid, has vast applications in the field of vibration dampers, seismic vibration dampers, shock absorbers, clutches, break system, vehicle suspensions, seat suspensions, Robotics, design of buildings and bridges etc. The biggest issue in MR fluid is the settling of particles under gravity. To overcome this, one of the approaches is to mix micron size particles in a magnetic fluid (MF) known as Nano-MRF. In the present paper, we report a technique to synthesis Nano-MRF suspension having high stability under gravitation as well as magnetic field. X-ray diffraction (XRD) and dynamic light scattering are used to characterize the solid/liquid system. Magnetic and Magnetorheological properties are studied and results indicate that: instead of decreasing stress with increasing temperature we have observed an increase until 40°C and thereafter, it decreases. This is explained based on, inter and intra particles/chain interaction as well as synergetic effect between small and large sized magnetic dispersion.

scholarly journals Simple Protocol for the Knoevenagel Condensation Under Solvent Free Conditions using Tungstophosphoric Acid as Catalyst

2019 ◽  
Vol 31 (10) ◽  
pp. 2181-2184
Author(s):  
Abdulrahman I. Alharthi
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Room Temperature ◽  
Model Compound ◽  
Knoevenagel Condensation ◽  
Maximum Yield ◽  
Tungstophosphoric Acid ◽  
Grinding Method ◽  
Solvent Free Conditions ◽  
Simple Protocol

The effect of calcination on the performance of tungstophosphoric acid for the product of Knoevenagel condensation was investigated. Substituted aldehydes and dimedone has been used in the presence of calcined tungstophosphoric acid as a heterogeneous catalyst using grinding method at room temperature. The results of reactions revealed that calcined tungstophosphoric acid has superior catalytic activity comparing to non-calcined catalyst in terms of yield and reaction time. Maximum yield of model compound was achieved by using 10 mol% of calcined catalyst in a reaction time that does not exceed 10 min, whereas the yield at same amount of non-calcined catalyst was 86 % in a reaction time of 35 min.

The Activation Technology for the Surface Modification High Voltage Electric Field Dispersed Mineral Additives for Concrete

2020 ◽  
Vol 1011 ◽  
pp. 23-30
Author(s):  
A. Khalyushev ◽  
A. Mayilyan ◽  
Sergey Stelmakh ◽  
Evgeniy Shcherban
Keyword(s):  
Surface Modification ◽  
Electric Field ◽  
Calcium Hydroxide ◽  
High Voltage ◽  
Sedimentation Rate ◽  
Liquid System ◽  
Interparticle Interactions ◽  
Surface Modified ◽  
Solid Liquid ◽  
Mineral Additives

The aim of the research was to study the activation technology of the materials for concrete by their surface modification in a high-voltage electric field. It is noted that the mineral additives modified in a high-voltage electric field are characterized by a higher activity of the calcium hydroxide absorption. It was established that, despite the presence of a large number of crystalline compounds in metakaolin, its pozzolanic activity in the absorption of calcium hydroxide from a saturated solution is quite high. The same value of the hydration activity coefficient is also determined for the ground slag. The authors found that a characteristic feature of the dispersed mineral additives, surface-modified in a high-voltage electric field in comparison with control samples, are the lower values ​​of bulk density and repose angle. This is due to a change in the forces balance that occurs during the mutual contact of particles. The influence of the mineral additives’ surface modification in a high-voltage electric field on interparticle interactions in the “solid – liquid” system is evaluated. It is established that in the absence of a repulsion barrier, the particles form the aggregates that increase their sedimentation rate. During unipolar or bipolar charging of particles in an electric field, the sedimentation rate slows down or accelerates accordingly. These effects are used to modify the cement surface.

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