Precipitation of barium sulfate: Induction time and the effect of an additive on nucleation and growth

1992 ◽  
Vol 152 (2) ◽  
pp. 338-350 ◽  
Author(s):  
M.C van der Leeden ◽  
D Kashchiev ◽  
G.M Van Rosmalen
Author(s):  
Ricardo D. Sosa ◽  
Xi Geng ◽  
Jacinta C. Conrad ◽  
Michael A. Reynolds ◽  
Jeffrey D. Rimer

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Raul B. Rebak

Artificially creviced Alloy 22 (N06022) may be susceptible to crevice corrosion in the presence of high-chloride aqueous solutions, especially at higher temperatures and at anodic potentials. The presence of oxyanions in the electrolyte, particularly nitrate, inhibits the nucleation and growth of crevice corrosion. The current results show that crevice corrosion will develop in Alloy 22 when a constant potential above the crevice repassivation potential is applied to a creviced specimen. The analyses of the current output showed the presence of three characteristic domains: (1) passivation or induction time, (2) nucleation and growth, and (3) stifling and arrest. That is, under the tested conditions, crevice corrosion did initiate but after it reached a critical stage of growth, further damage stalled and the output anodic current returned to the passive values before the nucleation of the attack.


Langmuir ◽  
2016 ◽  
Vol 32 (21) ◽  
pp. 5277-5284 ◽  
Author(s):  
Chong Dai ◽  
Andrew G. Stack ◽  
Ayumi Koishi ◽  
Alejandro Fernandez-Martinez ◽  
Sang Soo Lee ◽  
...  

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 403 ◽  
Author(s):  
Lie-Ding Shiau

As the turbidity induction time measurements are influenced by the size distribution of the nuclei at the detection point, these data should provide important information on both nucleation and growth. A model is developed in this work to determine the nucleation and growth kinetics of aqueous L-glycine solutions using the turbidity induction time data for various supersaturations from 293.15 K to 313.15 K. The photomicroscopic growth experiments of aqueous L-glycine solutions are also conducted to determine the growth kinetics of nuclei under the same conditions for comparison. The results indicate that the interfacial energy obtained from this model is consistent with that obtained based on the traditional method by assuming t i − 1 ∝ J . The growth kinetics, including the growth activation energy and the kinetic growth parameter, obtained from this model using the induction time data are close to those obtained from the photomicroscopic growth experiments performed in this work.


2018 ◽  
Vol 159 ◽  
pp. 02065 ◽  
Author(s):  
F. Sariman ◽  
A.P. Bayuseno ◽  
S. Muryanto

Barium sulfate scaling usually occurs in pipelines of offshore oil drilling wells, which has become a persistent problem. This scale can create technical problems, including the increased energy in consumption and unscheduled equipment shutdown. This paper presents the crystallization of barium sulfate and this experiment was focused on evaluating the effect of solution concentration and malic acid to the induction time and barium sulfate crystallization. In this research, the experiments on the growth of barium sulfate scale in the pipe test was conducted by reacting BaCl2 and Na2SO4 at concentrations of 3500, 4000, 4500 and 5000 ppm Ba2+, flow rate (40 ml / min), temperature (50 °C), while malic acid (0, 5, 10 ppm) was added to the solution as a scale inhibitor. BaSO4 scale formation was observed with the declining value of the conductivity of the solution. BaSO4 crystal shape was observed from the results of morphological studies performed using SEM, further analysis of the micro-crystal composition using EDX and XRD analysis was used to prove the crystal produced. The SEM imaging shows that the morphology crystals have a star-like particle, while XRD analysis confirmed that the pure barite crystal (barite) was produced during the experiments. Obviously, the malic acid inhibited the crystal growth of barite.


Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee

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.


Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.


Author(s):  
L.E. Murr ◽  
V. Annamalai

Georgius Agricola in 1556 in his classical book, “De Re Metallica”, mentioned a strange water drawn from a mine shaft near Schmölnitz in Hungary that eroded iron and turned it into copper. This precipitation (or cementation) of copper on iron was employed as a commercial technique for producing copper at the Rio Tinto Mines in Spain in the 16th Century, and it continues today to account for as much as 15 percent of the copper produced by several U.S. copper companies.In addition to the Cu/Fe system, many other similar heterogeneous, electrochemical reactions can occur where ions from solution are reduced to metal on a more electropositive metal surface. In the case of copper precipitation from solution, aluminum is also an interesting system because of economic, environmental (ecological) and energy considerations. In studies of copper cementation on aluminum as an alternative to the historical Cu/Fe system, it was noticed that the two systems (Cu/Fe and Cu/Al) were kinetically very different, and that this difference was due in large part to differences in the structure of the residual, cement-copper deposit.


Author(s):  
J.A. Eades ◽  
E. Grünbaum

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.


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