Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 32 for “"Scale formation"”.
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Scale formation, properties and de-scaling in steelmaking
… containing oxidizing gases which results in scale formation. Inefficient removal of the formed scale during reheating affects product surface quality. The effect of steel composition and operating parameters on scale formation and scale removal efficiencies were investigated. Experimental …
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Gypsum seeding to prevent scale formation and improve separation efficiency
… seeding was effective in decreasing the mass of scale that formed on the heat transfer surface. Gypsum seeds improved gypsum crystallization kinetics in the bulk solution which resulted in an increase in the mass of gypsum product. Gypsum seeding marginally increased melted ice purity, although …
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Gypsum scale formation on a heated copper plate under natural convection conditions and produced water remediation technologies review
… and thermal water treatment technologies. Formation of dihydrated calcium sulfate scale, also known as gypsum, on a heated copper plate is studied in lab. The copper plate, held at a given temperature, is immersed in a supersaturated solution of calcium sulfate prepared at a given …
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Investigating the influence of solute type and solute concentration on ice scale formation on Polypropylene Graphite (PP-GR) during Eutectic Freeze Crystallization
… treatment of hypersaline streams. However, the formation of ice scale layers on heat exchanger surfaces has hindered its industrial implementation. Previous studies have shown that smooth heat exchanger (HX) materials with low surface energy like Polypropylene Graphite (PP-GR), can help reduce …
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Scale prevention in sea water evaporators Part II: decarbonation-filtration treatment
… has been the deposition of an insulating scale composed of calcium sulfate, calcium carbonate, and magnesium hydroxide on the heat transfer surfaces of the evaporators. Various chemical and mechanical treatments have been successfully used by industry to prevent scale formation in fresh …
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Evaluating the Potential of Scaling due to Calcium Compounds in Hydrometallurgical Processes
… and experimental study on calcium sulphate scale formation in hydrometallurgical solutions containing various minerals was conducted. A new database for the Mixed Solvent Electrolyte (MSE) model of the OLI Systems® software was developed through fitting of existing literature data such as …
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The phytoplankton of a eutrophic lake : community dynamics and ultrastructural studies
… a and with varying Secchi disc visibility . Scale-bearing planktonic organisms from Sawley Dene were studied as whole mounts in the electron microscope and 30 taxa are distinguished, including 17 species of flagellate Chrysophyceae (Mallomonas and related genera). Comparative studies on …
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In-operando techniques for early-stage corrosion
… anoxic CO2 solution. The initial corrosion scales can have a significant impact on how corrosion progresses. In some cases, it may prevent further corrosion. In this study, we have aimed to capture the initiation and nucleation of early scale. It is not well understood but may provide …
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Desalination systems for the treatment of hypersaline produced water from unconventional oil and gas processes
… emerged as a strategy in many unconventional formations. However, although desalination systems are well understood in oceanographic and brackish groundwater contexts, their performance and design at significantly higher salinities is less well explored. In this thesis, this gap is addressed …
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Engineering aspects of calcium carbonate and magnesium hydroxide precipitation in waste water reclamation
… which may result in serious calcium carbonate scale formation problems. In the thesis this instability is attributed to two fundamental causes, (1) Incomplete precipitation, i.e. a kinetic problem. (2) The unintentional absorption of carbon dioxide from the air by the highly alkaline …
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Biomimetic approach to anti-fouling surfaces
Scale formation is recognized as one of the major problems affecting production in the oil and gas sector. There are many approaches to remove and prevent scaling with chemical inhibition, chemical scale removers and mechanical methods being the most prevalent ones. Recently the focus has shifted …
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Estudo da permeação de hidrogênio e fragilização pelo hidrogênio de um aço API 5L X80
… In addition, the growth of iron sulphides scales can take an important part on the diffusion process. This study investigates the behaviour of the API X80 steel in relation hydrogen absorption in solutions with different concentrations of H2S, at static and tensile tests conditions. It aims …
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In vivo imaging and morphogenesis of butterfly scale development
… of a butterfly sprout hundreds of thousands of scales with intricate micro- and nanostructures that determine the wings' optical appearance, wetting characteristics, thermodynamic properties, and aerodynamic behavior. This strategy—of enabling multifunctionality by controlling material structure …
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Design Strategies for Improving the Oxidation Resistance of Multi-Principal Element Alloys
… within the materials is said to suppress the formation of deleterioustopologically close packed (TCP) phases and stabilize simple microstructures while allowingfor heavy alloying to generate significant solid solution strengthening, slowed diffusivities,and highly tailorable microstructures. …
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The effectiveness of antiscalants when used on multi-stage flash distillers.
… is concerned with the testing of antiscalants (scale inhibitors) used to improve the performance of Multi-Stage Flash (MSF) distillers in Kuwait. This study describes and compares the thermal schemes, thermal efficiency and thermal performances ratios of the distillers when treated with three …
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Experimental and modelling studies on the phase behaviour of mutual solvents and their transport through porous media in oil/brine/mutual solvent systems in the context of scale inhibitor squeeze treatments
Oilfield scale is a significant problem in oil production which arises due to temperature and pressure changes and mixing of incompatible brines when a well is produced. The most successful and commonly used strategy for mitigating against oilfield scale is the application of scale inhibitor …
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Interfacial engineering to control phase transitions : applications in icing and mineral scale fouling
Icing and scale fouling affect the functioning of a number of industries. The problems due to ice accretion have been prevalent for decades in a number of systems including aircrafts, wind turbines and power lines. Similarly, scale formation is one of the major problems that currently plague a …
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Investigating the Effect of Heat Transfer Driving Force and Seed Loading on the Batch Eutectic Freeze Crystallization of a Dilute Brine
… from the bulk and ice formed on the wall (scale). The yield of ice in the bulk decreased with increasing ΔTLMTD, whilst the yield of scale increased. As ΔTLMTD increased, the cooled wall became colder, therefore the fluid closest to the wall had the most supersaturation. This led to the …
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Heat transfer and scale resisting properties of silicone resins
… film coefficient of heat transfer and on the formation of gypsum seals were studied. The heat-exchanger tubes consisted of 74 ½-in. sections of 1-in. Nominal diameter standard iron pipe into whose surface were installed six copper-constantan thermocouples for measuring the temperature of the …
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Improving Oxidation Resistance in Polycrystalline Ni-based Superalloys for High-Temperature Applications
… oxidation transition for the formation and maintenance of a continuous Al₂O₃ scale were used in computational models to assess commercial alloys and an experimental alloy (Alloy X). The models successfully predicted the oxidation behaviour of the commercial alloys but …
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