The effect of hydrodynamic cavitation on performance of the alkaline aluminosilicate coatings for metal structures

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Sergii GUZII 1 ◽  
Pavel KRIVENKO 1
Keyword(s):  
Protective Coatings ◽  
Optimal Parameter ◽  
Metal Substrate ◽  
Hydrodynamic Cavitation ◽  
Major Constituent ◽  
Atmospheric Conditions ◽  
Hydration Products ◽  
Metal Structures ◽  
Coated Metal ◽  
Short Period

Load-bearing metal structures working in atmospheric conditions are exposed to corrosion. Known-in-the art paint-and-lacquer protective coatings can provide protection of metal for rather short period of time (5…10 years). These structures can be effectively protected by more advanced coatings of new generation, namely: alkaline aluminosilicate binder-based coatings of barrier type. These binders differ from the known-in-the-art binding materials by formation in their hydration products of zeolite-like minerals and feldspathoids. The paper discusses principles laid down in formulating the binder composition in the (хК, уNa)2OAl2O3nSiO2mH2O system, target synthesis of hydration products of the binder matrix under influence of dynamic of the binder matrix in cavitation, optimal parameter order to synthesis of cavitation treatment aimed at nanostructuring of zeolite-like and hydromica phases after solidification. These coatings exhibit high corrosion resistance, high adhesion to metal substrate and durability results of restoration works that had been carried out in December 2010 of the Big Bell Tower of the Kiev Petchersk Lavra in order to protect corroded metal surfaces by applying the aluminosilicate binder-based coatings, the major constituent (binder) of which was represented by (0.72Na2O+0.28K2O)1.5Al2O3(4.56)SiO217.5H2O are discussed in details. In 2016, after 6 years of service in high humidity conditions and other aggressive exposures, the coated metal structures were examined and no sign of corrosion of metal substrate and damage of the applied coating was found.

Atmospheric Corrosion Protection of Metallic Structures Using Geocements-Based Coatings

2015 ◽  
Vol 227 ◽  
pp. 239-242
Author(s):  
Pavel Krivenko ◽  
Sergii Guzii ◽  
Hameedi Abdullah Jafar Al-Musaedi
Keyword(s):  
Atmospheric Corrosion ◽  
Protective Coatings ◽  
Atmospheric Conditions ◽  
Hydration Products ◽  
Optimal Parameters ◽  
Metallic Structures ◽  
High Adhesion ◽  
Short Period ◽  
New Generation ◽  
Target Synthesis

It is known that load-bearing metallic structures that are in service in the atmospheric conditions showed that are exposed to corrosion. The known-in-the art paint-and-lacquer protective coatings can provide protection of metal surfaces for a rather short period between 5 to 10 years. That is why these structures should be protected by the more advanced coatings of new generation, namely: geocement-based coatings which differ from the known-in-the-art binding materials by formation in the hydration products of the zeolite-like minerals and feldspathoids. The paper discusses substantiation of choice of geocement composition in the (хК, уna)2O⋅Al2O3⋅nSiO2⋅mH2O system, target synthesis of hydration products of the geocements matrix in the fields of dynamic cavitation, optimal parameters of cavitation treatment aimed at nanostructurization of the geocements matrix in order to synthesize zeolite-like and hydromicaceous phases, choice of appropriate hardening agents and fillers etc. for producing highly efficient protective coatings with high corrosion resistance, high adhesion to metallic substrate and durability.

Corrosion at a Holiday in an Organic Coated-Metal Substrate System

CORROSION ◽  
1976 ◽  
Vol 32 (8) ◽  
pp. 316-321 ◽  
Author(s):  
B. D. CRAIG ◽  
D. L. OLSON
Keyword(s):  
Corrosion Rate ◽  
Ion Transport ◽  
Water Uptake ◽  
Galvanic Corrosion ◽  
Organic Coating ◽  
Metal Substrate ◽  
Galvanic Current ◽  
Factors Affecting ◽  
Coated Metal ◽  
Significant Factors

Abstract The galvanic corrosion at a holiday in an organic coating was investigated by measuring the galvanic current as a function of time. It was found that an area of exposed metal (holiday) in the coating will be anodic to the coated areas. Water uptake and ion transport of the coating are significant factors affecting the corrosion taking place at a holiday. Thickness of the coating was also found to be an important influence on the corrosion rate at a holiday.

scholarly journals Surface preparation as one of the main factors for ensuring the durability of anti-corrosion coatings

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Aleksei Bezgodov ◽  
Ilya Ovchinnikov
Keyword(s):  
Surface Treatment ◽  
Protective Coatings ◽  
Surface Preparation ◽  
Negative Consequences ◽  
Treatment Methods ◽  
Factors Affecting ◽  
Metal Structures ◽  
Optimal Processing ◽  
Main Factors ◽  
Paint Coatings

This article is devoted to the protection of bridge metal structures from corrosion. The article was written with the aim of studying one of the stages of anti-corrosion treatment, namely the preparation of the surface before applying a protective coating. In the article, the authors address the problem of the durability of paint coatings, and point to the main reasons, to a greater extent, affecting the service life. Studying the problem of the durability of protective coatings, the authors distinguish such a stage as preparing the metal surface of the bridge structure before applying the paintwork. The authors tell how important the preparation of the surface is and what negative consequences are possible if it is disturbed or not. For a more detailed study of the problem, the authors consider several methods of preparing the surface of the structure, such as: abrasive blast cleaning, phosphating the surface and heat treatment. When studying the above mentioned methods, the authors describe the technology of the work, the main factors affecting the final result of processing, as well as the positive and negative sides of each of the methods. For each of the surface treatment methods, the authors present illustrations that clearly show the basic concept of the selected treatment option. Summing up the comparative analysis of surface treatment methods before applying anti-corrosion coatings, the authors chose the most optimal processing method, as well as concluded that the importance of this stage and the possibility of its further improvement.

Aqueous Washable Thermal Resistant Coatings and Adhesives

2018 ◽  
Vol 2018 (1) ◽  
pp. 000767-000772 ◽  
Author(s):  
John Moore
Keyword(s):  
Laser Processing ◽  
Protective Coatings ◽  
Water Film ◽  
Water Soluble ◽  
Major Constituent ◽  
Organic Substrates ◽  
Uv Curable ◽  
Porous Carriers ◽  
Temporary Bonding ◽  
Industry Needs

Abstract Many packaging processes require thin and fragile components to be protected or held securely in place for temporary periods of time. The most common process flow is to: apply the coating, cure or use to bond a device, conduct the process, and finish with removing the coating by washing in a liquid chemistry. Aqueous cleaning is deemed safer for devices on organic laminates and in the presence of molding compounds. These reagents use water as their major constituent. They are compatible with organic substrates (panels, laminates, boards), are worker safe, and require less expensive operating equipment. Aqueous washing is generally green and exempt from the complexity and cost of environmental and waste management regulations. Daetec's washable coatings qualify as green, and exhibit thermal resistance over 300°C, making them one of the most unique materials on the market. These coatings enable soldering, laser processing, plasma etching, and dielectric curing, all following with simple water washing. Water washable DaeCoatTM 525 is a key choice in laser processing for debris removal around the heat activation zone (HAZ), while the etch-resistant DaeCoatTM 534 supports laser patterning for plasma singulation [1]. While DaeCoatTM 532 is water soluble, another material from the same family, DaeCoatTM 537 is not, yet will wash away in an aqueous surfactant, DaeClean™ S20 (10% in water). In many ways, these products act, as surfactants, but depending upon the chemistry, will dissolve in water or an aqueous agent. Customers desiring a green protective coating or adhesive for plating or etching processes, may apply DaeCoatTM 537, send through the processes, and then wash away in the S20 aqueous agent. All products are cast from water. Film forms as 50μm thick with peel away liners are available for DaeCoatTM 532 and 537. UV curable high solids versions are also available. Applications include planarizing coatings, adhesive for die solder attach, and C4 or micro bump protection. Protective coatings for EMI/RFI shielding, dicing operations, and temporary bonding operations that may use porous carriers have been demonstrated with water washable coatings and adhesives. The success in these and related temporary applications depend upon the use of the proper washable coating. Our experience in creating solutions for these and other industry needs will be discussed as well as the criteria for using temporary washable coatings.

scholarly journals ACCURACY IMPROVEMENT OF TROPOSPHERIC DELAY CORRECTION MODELS IN SPACE GEODETIC DATA. CASE STUDY: EGYPT

2014 ◽  
Vol 40 (4) ◽  
pp. 148-155
Author(s):  
Sobhy Abdel Monem Younes ◽  
Hafez Abbas Afify
Keyword(s):  
Elevation Angle ◽  
Tropospheric Delay ◽  
Limiting Factor ◽  
Data Sets ◽  
Atmospheric Conditions ◽  
New Model ◽  
External Data ◽  
Short Period ◽  
The Mean ◽  
Height Component

The tropospheric delay still remains a limiting factor to the accuracy of space based positioning techniques. The estimation of station positioning, especially height component, which is particularly important for more applications is susceptible to errors in modeling the tropospheric delay due to correlations between the station positioning and residual troposphere delay parameters. As the demand on positioning accuracy and precision has increased, it has begun a necessary of relaying on large external data sets, rather than relatively simple models for treating the tropospheric delay. This method has been possible by advances made in numerical weather models which provide accurate representations of global atmospheric conditions and by advances in computing speed which allow us to perform a large number of computations over a short period of time. The purpose of this work is to develop a new model for estimating the tropospheric delay and then assess the benefits of applying this model at various geographic atmospheric conditions of Egypt. By comparing new model with some common models such as Saastamoinen model, Hopfield model, Niell-MF, Black & Eisner-MF, UNB3 model and Vienna-MF, the results show that, new model for estimation tropospheric delay has an acceptable level of accuracy in describing the dry tropospheric delay in Egypt as it agrees closely with the numerical integration based model. The mean accuracy of this new model has been assessed to be about 9.64 mm with rms 11 mm at an elevation angle of 30° and for an elevation angle of 5°, the mean accuracy is about 83.23 mm with rms 96.42 mm for atmospheric conditions of Egypt.

scholarly journals Epimedium koreanumExtract and Its Constituent Icariin Improve Motor Dysfunction in Spinal Cord Injury

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chihiro Tohda ◽  
Aiko Nagata
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Chronic Treatment ◽  
Methanol Extract ◽  
Motor Dysfunction ◽  
Major Constituent ◽  
Active Constituent ◽  
Short Period ◽  
Cord Injury ◽  
Recovery Of Motor Function

Although cell transplantation strategies for spinal cord injury (SCI) using sources such as iPS cells and neural stem cells are focused as expectative therapies for SCI, the possibility of medication as more accessible and practical way should not be given up. We, therefore, aimed to develop medical sources for SCI. In this paper, we evaluated effects of a famous tonic herb,Epimedium koreanum, on motor dysfunction in spinal cord injury (SCI). The spinal cord was injured by contusion after laminectomy at T10 level. Oral administration of the methanol extract ofE. koreanumsignificantly enhanced hindlimb function in SCI mice by short period treatment (for initial 3 days) and chronic treatment (21 days), although chronic treatment recovered the function more potently. Since it is well known that icariin is the major constituent inE. koreanum, icariin was administered orally to SCI mice for initial 3 days. Motor dysfunction was ameliorated by icariin treatment similarly to the methanol extract ofE. koreanum. This paper is the first report to indicateE. koreanumis effective for recovery of motor function in SCI, and at least icariin is an active constituent.

scholarly journals Prefinished Metal Polymer Hybrid Parts

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Ines Kuehnert ◽  
Michaela Gedan-Smolka ◽  
Matthieu Fischer ◽  
Peter Scholz ◽  
Dirk Landgrebe ◽  
...  
Keyword(s):  
Thermoplastic Polyurethane ◽  
Powder Coating ◽  
Metal Substrate ◽  
Future Application ◽  
Process Chain ◽  
High Deformation ◽  
Coated Metal ◽  
Polymer Metal ◽  
Assembly Behavior ◽  
External Forces

In this study, the shaping and assembly behavior of adhesive polymer-metal-composites was investigated in an international cooperation using two step curable uretdione-polyester-based powder coatings (IPF development) which acts simultaneously as a reactive adhesive agent and as a high quality surface finish. To create the composite, a thermoplastic polyurethane (TPU) layer with good compatibility to the powder coating was over-molded onto a powder coated aluminum substrate. A polyamide (PA6) layer was over-molded on to the TPU layer to create a stiff composite structure with possibilities for further functionalization. The TPU-layer in between the metal substrate and the polymer top layer acts as a stress and strain compensation layer. These loads are caused by thermal expansion (under fluctuating temperatures) and external forces/deformation. Another key feature of the composite is the innovative process chain. The powder coating can resist high deformation and therefore the coating is suitable for a future application on to a metal substrate using a coil coating procedure. In addition, the coil could be easily implemented into a production line as a semi-finished product. The prefinished coated metal substrate could be formed (e.g. incremental forming, deep drawing) and inserted in the over-molding procedure. This overall shortened process chain allows not only an effective fabrication of pre-coated semi-finished materials and polymer-metal-joints in high quantities by saving process steps (e.g. cleaning steps, glue application) but also a higher versatility in the following composite production.

scholarly journals CAN SMOS SOIL MOISTURE DRY-DOWNS BE USEFUL TO DETECT FLOOD CONDITIONS OVER THE ARGENTINEAN PAMPAS PLAINS?

2020 ◽  
Vol XLII-3/W12-2020 ◽  
pp. 279-283
Author(s):  
L. Cappelletti ◽  
A. Sörensson ◽  
R. Ruscica ◽  
M. M. Salvia ◽  
E. Jobbágy ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Time Scales ◽  
Capillary Rise ◽  
Precipitation Anomaly ◽  
Water Dynamics ◽  
Atmospheric Conditions ◽  
Short Period ◽  
Dry Down ◽  
Spatio Temporal ◽  
Vegetation Water

Abstract. The process of soil drying following a single rainfall input offers an integrated perspective on soil-vegetation water dynamics in responses to atmospheric conditions during periods without rainfall. In this work, the soil moisture dry-down time scale events (τ) was calculated using surface soil moisture data from the SMOS mission, with the objective to explore if the spatio-temporal variability of τ could be used as a proxy for regional flooding and waterlogging characterization. Our working hypothesis is that soil moisture dries up more slowly under flooded conditions as a result of slower surface water elimination by infiltration and capillary rise of water from the saturated zone close to the surface. A clear difference precipitation-moisture coupling was detected between two regions with different flooding dynamics. In a region where flooding is triggered by precipitation excesses on weekly-to-monthly time scales and where the coupling between precipitation and evapotranspiration is strong, a positive correlation between dry-down and 6-month accumulated precipitation anomaly was found for all seasons except winter. By contrast, in the other region where flooding is largely de-coupled from precipitation and evapotranspiration, but rather coupled to ground water table dynamics on time scales from several months to years, no significant correlations were found. These results are based on a short period of data: March 2010 – November 2014.

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