scholarly journals Frontal Polymerization in Acrylic Acid System

2011 ◽  
Vol 8 (1) ◽  
pp. 75-82
Author(s):  
P. K. Srivastava ◽  
S. S. Majhi ◽  
B. K. Sarkar
Keyword(s):  
Acrylic Acid ◽  
Benzoyl Peroxide ◽  
Reaction Temperature ◽  
Test Tube ◽  
Frontal Polymerization ◽  
Initial Reaction ◽  
Initial Concentration ◽  
Maximum Value ◽  
Front Position ◽  
Initial Starting

Moving wave front have been investigated in acrylic acid / benzoyl peroxide / N, N-dimethyl aniline system in a test tube at 30oC temperature. Dependence of front velocity on initial concentration of benzoyl peroxide, and effect of hydroquinone was determined. Consumption of acrylic acid and benzoyl peroxide have been found to decrease exponentially with respect to front position. The variation of reaction temperature with respect to front position at different initial concentration of benzoyl peroxide and different initial starting temperature have been investigated. It has been established that the reaction temperature increases and attains a maximum value by increasing both benzoyl peroxide and initial reaction temperature. The rate of polyacrylic acid chain propagation has been determined.

Parameter Identification by Inverse Analysis Coupled with a Finite Pointset Method for Polyurethane Foam Expansion

2014 ◽  
Vol 611-612 ◽  
pp. 868-875 ◽  
Author(s):  
Hichem Abdessalam ◽  
Boussad Abbès ◽  
Yu Ming Li ◽  
Ying Qiao Guo ◽  
Elvis Kwassi ◽  
...  
Keyword(s):  
Parameter Identification ◽  
Reaction Temperature ◽  
Inverse Analysis ◽  
Stokes Equations ◽  
Foam Height ◽  
Test Tube ◽  
Navier Stokes ◽  
Foam Expansion ◽  
Mesh Free ◽  
Mesh Free Method

This paper deals with the parameter identification for polyurethane foaming process simulation by using an inverse analysis coupled with a Finite Pointset Method. Simultaneous measurements of the foam height rise, the reaction temperature and the viscosity on a cylindrical cardboard test tube are obtained by using the foam measurement system (FOAMAT). The simulation of the foam expansion is obtained by solving unsteady Navier-Stokes equations coupled with the energy equation, the curing reaction (reaction of isocyanate with polyol) and the foaming reaction (reaction of isocyanate with water to emit the CO2 gas) by using a mesh-free method. The inverse identification method consists in determining the parameters by comparing the computed quantities (height rise, reaction temperature and viscosity) computed by the finite pointset method to those measured experimentally.

The Research for Microwave Modified Vermiculite Adsorption of Zn2+

2014 ◽  
Vol 809-810 ◽  
pp. 493-499
Author(s):  
Li Fang Bao ◽  
Chen Li Wang ◽  
Jin Chuan Gu ◽  
Sheng Zhong ◽  
Rui Wang
Keyword(s):  
Reaction Time ◽  
Correlation Coefficient ◽  
Adsorption Isotherms ◽  
Reaction Temperature ◽  
Room Temperature ◽  
Adsorption Equilibrium ◽  
Adsorption Rate ◽  
Absorption Mechanism ◽  
Initial Concentration ◽  
The Impact

The impact on the adsorption of Zn2+of these factors, initial concentration, modification time, reaction time vermiculite dosage, reaction temperature and pH having, and absorption mechanism are studied . The results show that: microwave modification time 30s, reaction time 40min, modified vermiculite dosage 8g/L, reaction temperature 30°C, reaction pH 6, Zn2+ adsorption rate can reach 97.91%, adsorption isotherms of Zn2+ by microwave modified vermiculite show that the adsorption equilibrium is consistent with Langmuir curves, correlation coefficient reached to 0.997 at room temperature.

Process Optimization of Cefradine/ Montmorillionite in Solution Intercalation

2011 ◽  
Vol 306-307 ◽  
pp. 831-834
Author(s):  
Yan Zhao Zhao ◽  
Wen Ji Guo ◽  
Lan Wang
Keyword(s):  
Experimental Design ◽  
Process Optimization ◽  
Reaction Temperature ◽  
Drug Concentration ◽  
Orthogonal Design ◽  
Experimental Results ◽  
Mass Ratio ◽  
Drug Load ◽  
Solution Intercalation ◽  
Initial Concentration

One-factor-at-a-time design and orthogonal design were used in the experimental design to optimize the process of preparation for Cefradine /Montmorillionite composites in solution intercalation. Experimental results indicate that drug initial concentration was the most significant condition for optimal preparation of composites, intercalation time and reaction temperature were not so significant. In our paper, the maximum drug load occurred at reaction temperature of 60°C with the intercalation time of 2h when the drug concentration (mass ratio of cefradine to MMT) was 2:1.

Reactive Adsorption Desulfurization of Thiophene in n-hexane over Oxides Adsorbent of NiO-ZnO/Al2O3-SiO2

2013 ◽  
Vol 455 ◽  
pp. 43-47 ◽  
Author(s):  
Xiao Ming Hou ◽  
Ben Xian Shen ◽  
Ji Gang Zhao
Keyword(s):  
Reaction Time ◽  
Structural Properties ◽  
Reaction Temperature ◽  
Chemical Process ◽  
Removal Rate ◽  
Precipitation Method ◽  
Initial Concentration ◽  
Reactive Adsorption ◽  
Adsorption Desulfurization ◽  
Co Precipitation

The oxides adsorbent of NiO-ZnO/-Al2O3-SiO2 was prepared by co-precipitation method. SEM, XRD and BET studies were performed to understand the structural properties of the adsorbent. And the adsorbent can be used for the desulfurization of thiophene in n-hexane as model gasoline. Removal rate of thiophene increased with increasing reaction time. Removal rate of thiophene in equilibrium decreases with increasing the initial concentration of thiophene. The extent of adsorption in adsorbent increased with increasing the initial concentration of thiophene. The removal rate of thiophene increases with increasing reaction temperature, it showed that the desulfurization is a chemical process not a physical process.

Preparation of A Spherical Cellulose Adsorbent as Amino Acid Sorbent

2011 ◽  
Vol 197-198 ◽  
pp. 899-905 ◽  
Author(s):  
Chun Xiang Lin ◽  
Ming Hua Liu ◽  
Huai Yu Zhan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Reaction Time ◽  
Acrylic Acid ◽  
Reaction Temperature ◽  
Monomer Concentration ◽  
Initiator Concentration ◽  
Basic Amino Acids ◽  
Cellulose Adsorbent

The spherical cellulose adsorbent was prepared by grafting acrylic acid onto the spherical cellulose beads prepared by NMMO method. The effecting factors, e.g., monomer concentration, initiator concentration, reaction temperature and reaction time were optimized by the orthogonal and signal-factor experiments and the structure of the adsorbent was characterized by FTIR and SEM. The graft mechanism was also discussed. Moreover, the spherical cellulose adsorbents were shown to behave as good sorbents for basic amino acids L-Arg, L-Lys and L-His.

scholarly journals Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide

2006 ◽  
Vol 2006 ◽  
pp. 1-8 ◽  
Author(s):  
Ignazio Renato Bellobono ◽  
Giulia de Martini ◽  
Paola Maria Tozzi ◽  
Carmen Canevali ◽  
Franca Morazzoni ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Membrane Reactors ◽  
Quantum Yields ◽  
Peroxide Formation ◽  
Initial Concentration ◽  
A Value ◽  
Maximum Value ◽  
Radiant Power ◽  
Hydrogen Peroxide Formation ◽  
Kinetics Of

For some model molecules (methanoic and ethanoic acids, methane, and phenol), systematic investigations of quantum yields were carried out in the present paper, as a function of concentration and of absorbed radiant power. Quantum yieldsΦ∞, calculated from rates, followed an apparently Langmuirian function of initial concentrationC0, by whichΦ∞values at “infinite” concentration could be obtained. By having thus established that quantum yields of photomineralisationΦ∞are independent of radiation wavelength, within the absorption range of semiconductor, but depend on radiant power, such a dependency was experimentally investigated. For all the investigated molecules, the maximum allowable values reached in the low radiant power range clearly appeared as a plateau. On the contrary, at high radiant power values, another plateau, at a value of about 1/4-1/5 with respect to the maximum value, was evident. This was interpreted on the basis of a competition kinetics of hydroxyl radicals with themselves, leading to hydrogen peroxide formation, other than with substrate or intermediate molecules leading to full mineralisation. Modelling of quantum yields as a function of concentration and radiant power thus allows a fully consistent and trustworthy design of photoreactors.

Semibatch Aqueous-Solution Polymerization of Acrylic Acid: Simultaneous Control of Molar Masses and Reaction Temperature

2011 ◽  
Vol 5 (5-6) ◽  
pp. 223-231 ◽  
Author(s):  
Roque J. Minari ◽  
Gerardo Caceres ◽  
Paola Mandelli ◽  
Mariana M. Yossen ◽  
Manuel Gonzalez-Sierra ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Reaction Temperature ◽  
Solution Polymerization ◽  
Simultaneous Control ◽  
Aqueous Solution Polymerization

Turbulent Characteristics in Lead-Bismuth Flows Flowing in Poor and Good Wettability Pipes

2016 ◽  
Author(s):  
Gen Ariyoshi ◽  
Daisuke Ito ◽  
Yasushi Saito ◽  
Kaichiro Mishima
Keyword(s):  
Void Fraction ◽  
Liquid Velocity ◽  
Test Tube ◽  
Experimental Results ◽  
Wall Region ◽  
Two Phase ◽  
Maximum Value ◽  
Turbulent Characteristics ◽  
Electro Magnetic ◽  
Effect Of Surface

Lead-bismuth single-phase and two-phase upward flows in a round tube were measured by using an electro-magnetic probe and an electrical conductivity probe. Experiments were performed under adiabatic conditions by varying the superficial gas and liquid velocity from 0 to 0.04 m/s and 0.1 to 0.2 m/s respectively. From the experimental results, it was found that the local liquid velocity and the void fraction in the lead-bismuth two-phase flow take the maximum value near the wall region at low void fraction conditions. These results indicate bubbles would tend to flow along the wall surface due to the poor wettability of the test section to the lead-bismuth. To verify this hypothesis, the liquid velocity and void fraction were also measured by using a test tube with better wettability. In addition, the experimental results were compared with existing experimental results to evaluate the effect of surface wettability on flow structure of lead-bismuth.

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