scholarly journals Hydrodynamic Characterization of Physicochemical Process in Stirred Tanks and Agglomeration Reactors

2018 ◽  
Author(s):  
Benjamin Oyegbile ◽  
Guven Akdogan
Keyword(s):  
Physicochemical Process ◽  
Stirred Tanks

Improvement of RSM Prediction and Optimization by Using Box-Cox Transformation

2018 ◽  
pp. 156-191
Author(s):  
Mustafa Çırak
Keyword(s):  
Electrical Current ◽  
Physicochemical Process ◽  
Quadratic Model ◽  
Operational Parameters ◽  
New Model ◽  
Engineering Technique ◽  
Perfect Normality ◽  
Mineral Industries ◽  
Box Cox Transformation

Electrocoagulation can be effectively used in the elimination of the colloids from the tailings of the mineral industries. Owing to the numerous operational parameters of this physicochemical process, the best engineering technique for the characterization of the process is RSM. In this chapter, a non-transformed quadratic model is firstly formed considering the supernatant turbidity of the electrocoagulation experiments as a function of temperature, pH, and electrical current. Then, the non-normality and the heteroscedasticity of this initial model was indicated. These drawbacks were improved by using the Box-Cox transformation with λ of -0.32 and a new model with a perfect normality and homoscedasticity was obtained. The R2 value increased from 81.60% to 99.48% and adjusted R2 increased from 48.48% to 99.22% upon the transformation. According to the confirmed optimization results of the Box-Cox transformed model, the maximum desirability was obtained at pH of 5, temperature of 85°C, and electrical current of 0.25A, and the supernatant turbidity decreased down to 2.25 NTU.

Characterization of onset of entrainment in stirred tanks

2009 ◽  
Vol 87 (7) ◽  
pp. 951-961 ◽  
Author(s):  
R.G. Mali ◽  
A.W. Patwardhan
Keyword(s):  
Stirred Tanks

The Investigation on Preparation & Physicochemical Process of Nanosized Hydroxyapatite Powder

2002 ◽  
Vol 724 ◽  
Author(s):  
Yunjing Song ◽  
Shulin Wen ◽  
Musen Li
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Calcium Nitrate ◽  
Physicochemical Process ◽  
Ethanol Solution ◽  
Xrd Pattern ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Mean ◽  
Nitrate Tetra Hydrate

AbstractThe investigations of the preparation and physicochemical process of the HA nanostructured powder with high performance have been performed at present study. The HA preparation starts from the ethanol solution of calcium nitrate tetra-hydrate and phosphorous pentoxide as raw materials. The characterization of the effects of reacting temperatures on preparation, the crystalline degrees (some amorphous HA formed at certain condition) of the reacting products are carried out in the meanwhile. The physicochemical processes and the conditions for different reactions stages of the HA preparation have been traced and characterized by the TG-DTA (thermogravimetric and differential thermal analysis), the FTIR (Fourier-transformed infrared spectroscopy) and other methods. The investigations of the chemical reactions for the HA preparation show that the synthesis of HA is completely finished at the temperature of 500°for hours. The grain sizes and shapes of the HA reacting products are observed and characterized by the TEM and the XRD. The results show that the mean diameters of these product grains are as fine as 30-40nm at the temperature of 500°C. The XRD pattern of the present HA powders sintered at 500°C for 2h coincided very well with the JCPDS standards showing its superior purity and therefore, with really high performance for later applications.

scholarly journals Characterization of hydromechanical stress in aerated stirred tanks up to 40 m3 scale by measurement of maximum stable drop size

2014 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
Andreas Daub ◽  
Marina Böhm ◽  
Stefanie Delueg ◽  
Markus Mühlmann ◽  
Gerhard Schneider ◽  
...  
Keyword(s):  
Drop Size ◽  
Stirred Tanks

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Sign in / Sign up

Export Citation Format

Share Document