A mechanistic software platform for mineral surface deposition and inhibition prediction under different flow conditions

Desalination ◽  
2021 ◽  
Vol 509 ◽  
pp. 115071
Author(s):  
Zhaoyi (Joey) Dai ◽  
Yi-Tsung Lu ◽  
Amy Kan ◽  
Cianna Leschied ◽  
Yue Zhao ◽  
...  
Keyword(s):  
Software Platform ◽  
Mineral Surface ◽  
Flow Conditions ◽  
Surface Deposition

One-Dimensional Simulations of Jet Fuel Thermal-Oxidative Degradation and Deposit Formation Within Cylindrical Passages

2000 ◽  
Vol 122 (4) ◽  
pp. 229-238 ◽  
Author(s):  
J. S. Ervin ◽  
S. Zabarnick ◽  
T. F. Williams
Keyword(s):  
Fluid Dynamics ◽  
Jet Fuel ◽  
Thermal Oxidative Degradation ◽  
Fuel System ◽  
Flow Conditions ◽  
Surface Deposition ◽  
Deposition Rates ◽  
Fuel Oxidation ◽  
One Dimensional ◽  
Dissolved O2

Flowing aviation fuel is used as a coolant in military aircraft. Dissolved O2 reacts with the heated fuel to form undesirable surface deposits which disrupt the normal flow. For purposes of aircraft design, it is important to understand and predict jet fuel oxidation and the resulting surface deposition. Detailed multi-dimensional numerical simulations are useful in understanding interactions between the fluid dynamics and fuel chemistry. Unfortunately, the detailed simulation of an entire fuel system is impractical. One-dimensional and lumped parameter models of fluid dynamics and chemistry can provide the simultaneous simulation of all components which comprise a complex fuel system. In this work, a simplified one-dimensional model of jet fuel oxidation and surface deposition within cylindrical passages is developed. Both global and pseudo-detailed chemical kinetic mechanisms are used to model fuel oxidation, while a global chemistry model alone is used to model surface deposition. Dissolved O2 concentration profiles and surface deposition rates are calculated for nearly isothermal and nonisothermal flow conditions. Flowing experiments are performed using straight-run jet fuels, and the predicted dissolved O2 concentrations and surface deposition rates agree reasonably well with measurements over a wide range of temperature and flow conditions. The new model is computationally inexpensive and represents a practical alternative to detailed multi-dimensional calculations of the flow in cylindrical passages. [S0195-0738(00)01204-8]

Mineralogical Dynamics of Primary Copper Sulfides Mediated by Acidophilic Biofilm Formation

2017 ◽  
Vol 262 ◽  
pp. 325-329 ◽  
Author(s):  
Roberto A. Bobadilla-Fazzini
Keyword(s):  
Biofilm Formation ◽  
Copper Recovery ◽  
Process Conditions ◽  
Mineral Surface ◽  
Flow Conditions ◽  
Mineralogical Analysis ◽  
Acidophilic Microorganisms ◽  
Copper Sulfides ◽  
New Process ◽  
Sulfur Oxidizing

Bioleaching of copper sulfides is catalyzed by iron-and sulfur-oxidizing acidophilic microorganisms attached to the mineral surface forming a biofilm. However, the link between copper sulfides bioleaching and biofilm formation is not yet fully understood. Understanding the factors that are limiting the bioleaching kinetics for different copper sulfide minerals through exhaustive mineralogical analysis of the mineral surface with concomitant biofilm formation during the leaching process will deliver new process conditions with enhanced kinetics and higher copper recovery. In this work we have developed and standardized a reproducible flow cell method able to mimic heap/dump bioleaching laminar flow conditions to study the mineralogical dynamics by advanced mineralogical analysis including QEMSCAN and SEM-EDS coupled to biofilm formation analysis. Based on this method, the bioleaching mineralogical dynamics of primary copper sulfides (enargite (Cu3AsS4), chalcopyrite (CuFeS2) and bornite (Cu5FeS4)) have been determined in the presence of biofilm formation. Supported by the observed mineralogical dynamics, different mechanisms of dissolution for bioleaching were observed as well as selective biofilm formation over the mineral surface, showing enhanced conditions for copper recovery.

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

Thrombus formation on artificial surfaces: Correlative microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 840-841
Author(s):  
Quintin J. Lai ◽  
Stuart L. Cooper ◽  
Ralph M. Albrecht
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Thrombus Formation ◽  
Blood Platelets ◽  
Polymer Surfaces ◽  
Flow Conditions ◽  
Transmission Electron ◽  
Adhesion Of Platelets ◽  
Microscopic Techniques

Thrombus formation and embolization are significant problems for blood-contacting biomedical devices. Two major components of thrombi are blood platelets and the plasma protein, fibrinogen. Previous studies have examined interactions of platelets with polymer surfaces, fibrinogen with platelets, and platelets in suspension with spreading platelets attached to surfaces. Correlative microscopic techniques permit light microscopic observations of labeled living platelets, under static or flow conditions, followed by the observation of identical platelets by electron microscopy. Videoenhanced, differential interference contrast (DIC) light microscopy permits high-resolution, real-time imaging of live platelets and their interactions with surfaces. Interference reflection microscopy (IRM) provides information on the focal adhesion of platelets on surfaces. High voltage, transmission electron microscopy (HVEM) allows observation of platelet cytoskeletal structure of whole mount preparations. Low-voltage, high resolution, scanning electron microscopy allows observation of fine surface detail of platelets. Colloidal gold-labeled fibrinogen, used to identify the Gp Ilb/IIIa membrane receptor for fibrinogen, can be detected in all the above microscopies.

Hydrodynamic flow conditions through permeable walls

1992 ◽  
Vol 2 (8) ◽  
pp. 1565-1569
Author(s):  
S. Vollmar ◽  
J. A. M. S. Duarte
Keyword(s):  
Hydrodynamic Flow ◽  
Flow Conditions ◽  
Permeable Walls

Platelet and Shear Rate Promote Tumor Cell Adhesion to Human Endothelial Extracellular Matrix - Absence of a Role for Platelet Cyclooxygenase

1989 ◽  
Vol 61 (03) ◽  
pp. 485-489 ◽  
Author(s):  
Eva Bastida ◽  
Lourdes Almirall ◽  
Antonio Ordinas
Keyword(s):  
Cell Adhesion ◽  
Shear Rate ◽  
Tumor Cell ◽  
Umbilical Vein ◽  
Blood Platelets ◽  
Flow Conditions ◽  
Tumor Cell Adhesion ◽  
Rate Dependent ◽  
Static Conditions

SummaryBlood platelets are thought to be involved in certain aspects of malignant dissemination. To study the role of platelets in tumor cell adherence to vascular endothelium we performed studies under static and flow conditions, measuring tumor cell adhesion in the absence or presence of platelets. We used highly metastatic human adenocarcinoma cells of the lung, cultured human umbilical vein endothelial cells (ECs) and extracellular matrices (ECM) prepared from confluent EC monolayers. Our results indicated that under static conditions platelets do not significantly increase tumor cell adhesion to either intact ECs or to exposed ECM. Conversely, the studies performed under flow conditions using the flat chamber perfusion system indicated that the presence of 2 × 105 pl/μl in the perfusate significantly increased the number of tumor cells adhered to ECM, and that this effect was shear rate dependent. The maximal values of tumor cell adhesion were obtained, in presence of platelets, at a shear rate of 1,300 sec-1. Furthermore, our results with ASA-treated platelets suggest that the role of platelets in enhancing tumor cell adhesion to ECM is independent of the activation of the platelet cyclooxygenase pathway.

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