Academic literature on the topic 'Testa peeling'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Testa peeling.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Testa peeling"
1
Putra, Yukodharma, Erry Rimawan, Ahmad Rusdi, and Andrianto . "Design and Peformance Test of Coconut Skin Testa Peeling Machine." International Journal of Innovative Science and Research Technology 5, no. 7 (2020): 93–97. http://dx.doi.org/10.38124/ijisrt20jul027.
Full textAbstract:
Coconut nicknamed "Tree of Life" because it is a multi-purpose agricultural commodities in which all parts of the coconut plants are beneficial to humans. One of the results of the coconut is coconut oil. To get the oil required several processes such as coconut testa peeling the skin. Coconut testa skin peeling process is still done manually using a special knife that takes time and considerable manpower. In addition, there is a risk of a knife scraped manually peeling process. It required skinner testa machine to increase production capacity and avoid the risks that occur when using the manual method. Skinner testa machine design results can peel testa with peeling efficiency of 90% with the time it takes for 15 minutes to peel as many as 20 coconuts. Costs for skin peeling coconut testa che
2
Huddar, Vivekanand B., Abdul Razak, Erdem Cuce, et al. "Thermal Performance Study of Solar Air Dryers for Cashew Kernel: A Comparative Analysis and Modelling Using Response Surface Methodology (RSM) and Artificial Neural Network (ANN)." International Journal of Photoenergy 2022 (July 5, 2022): 1–18. http://dx.doi.org/10.1155/2022/4598921.
Full textAbstract:
In this study, a new procedure for drying of cashew kernels is proposed. The new methodology involves the use of solar air dryers to remove the dark sticky coating called testa on the surface of the cashew kernel to get the final product. There are several challenges in the new procedures, especially with respect to the moisture level to be retained in the cashew kernel post drying for facilitating the optimal peeling activity. In this regard, thermal performance is carried out through a set of experimental and computational trials. The experiments have revealed that the natural and forced convection solar dryers with drying speeds of 1.0 kg/h and 1.66 kg/h, respectively, showed drying efficiencies of 51.7% and 50.9%, which is within the permissible acceptable limit, thus ascertaining a moisture reduction of 40 to 42% in each of case and keeping the moisture content within the band of approximately 5%, required for effective peeling of the testa from the cashew kernel to obtain the final product. This new method has resulted in batch drying of cashew kernels of up to 30 kg capacity in a time span of 360 minutes of solar irradiation with an average consumption of 255 kJ. The results of the experiments are also validated from the artificial neural network (ANN) and response surface methodology (RSM) modelling, resulting in better prediction and optimization of the performance parameters. The error between the actual and experimental values is well within the permissible limit of +/-5%, thereby correlating the experimental and statistical values for deriving an ANN model for predicting the results for different time duration and solar irradiation. In this way, the thermal analysis of the solar dryers for drying cashew kernels has resulted in findings, which shall be utilized to improve the overall performance efficiency and the methodology adopted for maximum yield.
3
Kozlov, S., and V. Koridze. "Comparison of domestic and European methods of testing concrete for frost resistance." Bulletin of Science and Practice, no. 4 (April 15, 2017): 123–25. https://doi.org/10.5281/zenodo.546277.
Full textAbstract:
The need for the existence of the test methods of concrete on frost–resistance both in the Russian Federation and the European Union due to the fact that much of Russia and much of the territories of the European countries are in the temperate zone, which is characterized by multiple transitions so-temperature through zero within calendar year, as well as the presence of snow cover lasting from 3 to 8–9 months. Currently, the Russian Federation, frost resistance of concrete is determined in accordance with GOST 10060-2012. “Concrete Methods for determining frost”, whereby the test was carried out on concrete samples–cubes by their multiple pope–belt freezing and thawing in water–saturated condition, using the quality saturation medium water or to accelerate the test, 5%-aqueous solution of sodium chlorite–grained. Reason to assume that the test concretes confirmed predetermined design mark on frost resistance is the simultaneous implementation of after–following conditions: no visible external damage samples in the form of chips, tre–communities, peeling and so on and decrease the compressive strength as a result of a predetermined number testing cycles is not more than 10% (in light concrete — not more than 15%) and the amount of weight loss of no more than 2%. Strength criteria laid down in the concrete domestic test method to frost more stringent than European, because of more severe climate that in most regions of the Russian Federation in comparison with European countries.
4
Gunarathna, R.A.M.M., and M.L.R. Meragalge. "Full Factorial Design of Experiment Approach to Design and Optimize the Performance of Industrial Coconut Testa Peeling Mechanism for Sri Lankan Manufacturing Industry." September 12, 2023. https://doi.org/10.5281/zenodo.8337217.
Full textAbstract:
Sri Lanka has the fourth largest coconut export market in the world. Desiccated coconut, brown fiber, virgin coconut oil, and coconut water are some popular exports among number of export products. Coconut testa should be peeled off in most of the coconut product manufacturing processes. Although testa peeling is common for a many coconut products, manual peeling method is still used in Sri Lankan manufacturing industry. Freezing, boiling, baking, and specialized machines are different methods that can be used except manual peeling. In this research the best mechanism for testa peeling to replace manual peeling is identified and the identified process is optimized by conducting number of experimental runs. Automation the manual peeling mechanism has been identified the well suited solution for the current requirements in the Sri Lankan coconut manufacturing industry. A Prototype was fabricated and experiments were conducted to identify the best parameter settings for coconut testa peeling. The effect of Grater thickness, Contact angle and Grater rotational speed were considered and the thickness of the peeled testa were observed as the output parameter. Full Factorial Design of Experiment (DOE) was conducted by changing parameters in different levels. Grater thickness and Contact angle show significant impact on the thickness of testa while grater rotational speed does not show a significant impact at 5 % significance level. Thickness of the testa can be optimized by setting Contact angle in high level and Grater thickness in the lower level.
5
Pesce, Fabiola, Lucia Parafati, Biagio Fallico, and Rosa Palmeri. "Use of liquid nitrogen as pistachio peeling agent: quality parameters of kernel and skins (testa)." Food and Bioproducts Processing, November 2024. http://dx.doi.org/10.1016/j.fbp.2024.11.023.
Full text
6
Chhavi, Verma. "Physiochemical Screening of Carica papaya Leaves with Specific Reference to Their Pharmacognostical Evaluation." February 4, 2021. https://doi.org/10.5281/zenodo.4500409.
Full textAbstract:
Carica papaya is made to develop pharmacognostical characters of leaf with their morphological, microscopical, and physical characters including histochemical analysis. Morphological evaluation as color, odor, taste, size, shape, surface, and powder microscopy of plant shows the presence of endosperm cell which is polygonal in shape and contains aleurone grains and oil droplet, cell of testa, yellow coloring matter, and starch grains. Quantitative leaf microscopy to determine palisade ratio, stomata index, and vein-islet number is carried out. Peels are removed mechanically through epidermal peeling off and stomatal index (SI) is calculated. The vein-islet number, vein termination number, and palisade ratio of lamina are determined according to the standard method. We prepared the extracts of plant with different solvents for determining the different extractive values by maceration, Soxhlet extraction, successive extraction process, and determination of ash values, pH value, moisture content, and phytochemical screening to show the presence of carbohydrates, phenolic compounds, flavonoids, alkaloids, proteins, saponins, and lipids in the drug extract and fluorescence analysis in different solvent. Analysis of pesticide residues, aflatoxin, and heavy metals are also performed
7
"Sustainable Energy for Drying of Cashew Kernels – Experimental Research." International Journal of Innovative Technology and Exploring Engineering 8, no. 6S4 (2019): 1193–98. http://dx.doi.org/10.35940/ijitee.f1246.0486s419.
Full textAbstract:
Drying is an important process in food preservation. In cashew processing industries cashew kernels are dried for easy peeling of the thin brownish sticky layer known as testa. For this it is necessary to reduce the average moisture content of 13% to 5%. Drying is achieved by direct and indirect methods like traditional open sun and using conventional energy through dryers. Due to control of the air properties in indirect drying cashew kernels can be dried at faster rate and can retain their quality. Air flow passages also play an important role in drying process. The objective of the study is to investigate experimentally the energy consumption for drying 1 kg of cashew kernel using electrically assisted heating and to evaluate the feasibility of active solar air dryer for drying in cashew processing industries. An electrical heat-assisted dryer (EHD) and an active solar flat plate collector air dryer (ASAD) systems are designed and developed using locally available materials. Both the systems are tested for reduction in moisture content with series of experiments. EHD is tested with three different drying chambers for optimum drying rate. In its final test drying chamber without baffle plates has resulted in reduction in moisture content to required level by 5% in three hours with drying rate of 2.8 kg/h against 6.5% and 6.8% in single tray version and four trays with baffle plate version. The drying efficiency of drying chamber is found to be 30.54%. In ASAD system the experimental results ensure the drying of cashew kernels within stipulated time of 6 hours with drying rate of 1.66 kg/h and energy consumption of 255 kJ against 270 kJ of electrical heater drying. The drying chamber exhibits an efficiency of 50.89%. The study suggests that the design is feasible to small, cottage industries for cashew kernel drying. The energy savings up to 3750 kJ per day for a batch of 15 kg is possible.
8
Kozuń, Marta. "DELAMINATION PROPERTIES OF THE HUMAN THORACIC ARTERIAL WALL WITH EARLY STAGE OF ATHEROSCLEROSIS LESIONS." Journal of Theoretical and Applied Mechanics 54, no. 1 (2017). https://doi.org/10.15632/jtam-pl.54.1.229.
Full textAbstract:
The aim of this work is to determine mechanical properties of interfaces between layers of the human thoracic aortic wall with early stages of atherosclerosis lesions. Circumferential (n = 48) and axial (n = 15) specimens have been prepared and the mechanical properties of the interfaces between the layers have been determined on the basis of the peeling test. The results show that the mechanical and dissection properties of the interfaces between the layers depend on the direction of the tests. The results confirm that the early stage of atherosclerosis does not affect the mechanical parameters of the layer interfaces and does not affect resistance of the vessel wall to delamination.
9
Savino, Vincenzo, Luca Lanzoni, Angelo Marcello Tarantino, and Marco Viviani. "A cohesive FE model for simulating the cracking/debonding pattern of composite NSC-HPFRC/UHPFRC members." September 6, 2022. https://doi.org/10.1016/j.conbuildmat.2020.119516.
Full textAbstract:
The aim of this work is to propose to practitioners a simple cohesive Finite-Element (FE) model able to simulate the cracking/debonding pattern of retrofitted concrete elements, in particular Normal-Strength-Concrete members (slabs, bridge decks, pavements) rehabilitated by applying a layer of High-Performance or Ultra-High-Performance Fiber-Reinforced-Concrete as overlay. The interface was modeled with a proper nonlinear cohesive law which couples mode I (tension-crack) with mode II (shear-slip) behaviors. The input parameters of the FE simulation were provided by a new bond test which reproduces a realistic condition of cracking/debonding pattern. The FE simulations were accomplished by varying the overlay materials and the moisture levels of the substrate surface prior to overlay, since findings about their influence on the bond performances are still controversial. The proposed FE model proved to effectively predict the bond failure of composite NSC-HPFRC/UHPFRC members.
Dissertations / Theses on the topic "Testa peeling"
1
Fan, Dongliang Fan. "Lap-shear test: from “Kendall’s steady peeling” to “catastrophic failure”." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1523316028088973.
Full text
2
Hailesilassie, Biruk Wobeshet. "Mechanisms of Blister Formation on Concrete Bridge Decks with Waterprooving Asphalt Pavement Systems." Licentiate thesis, KTH, Väg- och banteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-124078.
Full textAbstract:
Bridge decks are commonly subjected to harsh environmental conditions that often lead to serious corrosion problems triggered by blisters under the hot mix asphalt bridge deck surfacing and secretly evolving during weather exposure until damage is often detected too late. Blisters may form under both the waterproofing dense mastic asphalt layer or under the waterproofing membrane which is often applied as additional water protection under the mastic asphalt (MA). One of the main technical issues is the formation of blisters under the membrane and asphalt-covered concrete structures caused by a complex mechanism governed by bottom-up pressure and loss of adhesion. A linear viscoelastic finite-element model was developed to simulate time-dependent blister growth in a dense mastic asphalt layer under uniformly applied pressure with and without temperature and pressure fluctuation. A finite element model was developed using ABAQUS with linear viscoelastic properties and validated with a closed form solution from first-order shear-deformation theory for thick plates. In addition, the blister test was conducted on different samples of MA in the laboratory and digital image correlation measurement technique was used to capture the three-dimensional vertical deflection of the MA over time. It was found that the blister may grow continuously under repeated loading conditions over subsequent days. With respect to blistering under waterproofing membranes, mechanical elastic modeling and experimental investigations were performed for three different types of membranes under in-plane stress state. The orthotropic mechanical behavior of a polymer modified bitumen membrane (PBM) was determined from biaxial test data. Finally, blister tests by applying controlled pressure between orthotropic PBMs and concrete plates were performed for studying the elliptical adhesive blister propagation using digital 3D image correlation. The energy calculated from elliptical blister propagation was found comparable to the adhesive fracture energy from standard peeling tests for similar types of PBMs. This indicates that the peeling test assists to evaluate and rank the adhesive properties of different types of membranes with respect to blister formation at room temperature without conducting time consuming and complicated pressurized blister propagation tests using digital 3D image correlation.<br><p>QC 20130625</p>
3
Gonzalez, Laura N. "Study Of The Effect Of The Environmental Relative Humidity On The Angle Dependent Peeling Strength Of Pressure Sensitive Adhesives (PSA)." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1439549093.
Full text
4
Yu-Chiao and 沈玉嬌. "Sealing and Peeling Test Gauge R&R Nested Study for Surface Mount Supplies Process." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/24078963557751093962.
Full textAbstract:
碩士<br>萬能科技大學<br>經營管理研究所<br>97<br>Quality is the foundation of any company to survive in a competitive market. No matter how simple a product is, quality cannot be neglected. In the past, many evaluation of quality were carried out by human judgments. Therefore, it makes quantification of quality evaluation difficult. Furthermore, it makes it impossible to prove an evaluation system adequate for a specific product quality level. This study is based on a real product functional inspection development. It includes customer application simulation, preliminary product functional evaluation, a Measurement System Analysis (MSA) for the interested product function combined with designed experiments, presentation of experiment results by MINITAB, and discussion of future improvement. US auto industries have been advocating QS9000, which was updated to TS16949 of these years, for many years, as a component of that quality assurance system, MSA has drawn great attention. It has been a new trend that quality evaluation and decision making are based on quantified measurement.
5
Su, Ying-Yu. "Analytical Study on Adhesively Bonded Joints Using Peeling Test and Symmetric Composite Models Based on Bernoulli-Euler and Timoshenko Beam Theories for Elastic and Viscoelastic Materials." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8828.
Full textAbstract:
Adhesively bonded joints have been investigated for several decades. In most analytical studies, the Bernoulli-Euler beam theory is employed to describe the behaviour of adherends. In the current work, three analytical models are developed for adhesively bonded joints using the Timoshenko beam theory for elastic material and a Bernoulli-Euler beam model for viscoelastic materials.
One model is for the peeling test of an adhesively bonded joint, which is described using a Timoshenko beam on an elastic foundation. The adherend is considered as a Timoshenko beam, while the adhesive is taken to be a linearly elastic foundation. Three cases are considered: (1) only the normal stress is acting (mode I); (2) only the transverse shear stress is present (mode II); and (3) the normal and shear stresses co-exist (mode III) in the adhesive. The governing equations are derived in terms of the displacement and rotational angle of the adherend in each case. Analytical solutions are obtained for the displacements, rotational angle, and stresses. Numerical results are presented to show the trends of the displacements and rotational angle changing with geometrical and loading conditions.
In the second model, the peeling test of an adhesively bonded joint is represented using a viscoelastic Bernoulli-Euler beam on an elastic foundation. The adherend is considered as a viscoelastic Bernoulli-Euler beam, while the adhesive is taken to be a linearly elastic foundation. Two cases under different stress history are considered: (1) only the normal stress is acting (mode I); and (2) only the transverse shear stress is present (mode II). The governing equations are derived in terms of the displacements. Analytical solutions are obtained for the displacements. The numerical results show that the deflection increases as time and temperature increase.
The third model is developed using a symmetric composite adhesively bonded joint. The constitutive and kinematic relations of the adherends are derived based on the Timoshenko beam theory, and the governing equations are obtained for the normal and shear stresses in the adhesive layer. The numerical results are presented to reveal the normal and shear stresses in the adhesive.
Book chapters on the topic "Testa peeling"
1
Valori, Marcello, Vito Basile, Simone Pio Negri, Paolo Scalmati, Chiara Renghini, and Irene Fassi. "Towards the Automated Coverlay Assembly in FPCB Manufacturing: Concept and Preliminary Tests." In IFIP Advances in Information and Communication Technology. Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72632-4_3.
Full textAbstract:
AbstractIn modern electronics, flexible and rigid-flex PCBs are largely used due to their intrinsic versatility and performance, allowing to increase the available volume, or enabling connection between unconstrained components. Rigid-flex PCBs consists of rigid board portions with flexible interconnections and are commonly used in a wide variety of industrial applications. However, the assembly process of these devices still has some bottlenecks. Specifically, they require the application of cover layers (namely, coverlays), to provide insulation and protection of the flexible circuits. Due to the variability in planar shape and dimensions, the coverlay application is still performed manually, requiring troublesome manipulation steps and resulting in undetermined time-cycle and precision.This paper aims at the improvement of the industrial process currently performed, by proposing an approach for the automation of Kapton coverlay manipulation and application. Since these products are commercially provided as a film with a protective layer to be removed, the peeling issue is addressed, representing a challenging step of the automated process; the results of a systematic series of tests, performed in order to validate the peeling strategy, are reported in the paper. The overall assembly strategy relies on the development of a customized multi-hole vacuum gripper, whose concept is presented and contextualized in the proposed assembly process by outlining a suitable workcell architecture.
2
Mikno, Zygmunt. "Resistance Welding of Aluminium Alloys with an Electromechanical Electrode Force System." In Aluminium Alloys [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.93242.
Full textAbstract:
The idea presented in this chapter is an innovative welding machine electrode force system. The operation, advantages of the new solution and the optimisation of the welding process were illustrated by the welding of aluminium bars (5182) (ø 4 mm). The solution involves controlling the force and/or displacement of welding machine electrodes. The modulation of electrode force significantly improves welding, particularly as regards aluminium alloys (requiring a very short welding process). The tests involved the numerical analysis of two electrode force systems, i.e. a conventional Pneumatic Force System (PFS) and an Electromechanical (Servomechanical Force) System (EFS). The numerical tests were performed using SORPAS software. FEM calculation results were verified experimentally. The technological welding tests were conducted using inverter welding machines (1 kHz) equipped with various electrode force systems. The research included metallographic and strength (peeling) tests and measurements of characteristic parameters. The welding process optimisation based on the EFS and the hybrid algorithm of force control resulted in i) more favourable space distribution of welding power, ii) energy concentration in the central weld zone, iii) favourable melting of the material within the entire weld transcrystallisation zone, iv) obtainment of the full weld nugget and v) longer weld nugget diameter.
Conference papers on the topic "Testa peeling"
1
da Silva Pimenta, Egnalda Pereira, Arlindo Lopes, and Marinete de Souza. "Zinc Galvanized Steel’s Behavior after Accelerated Tests That Used High Chloride Ions Concentration." In LatinCORR 2023. AMPP, 2023. https://doi.org/10.5006/lac23-20390.
Full textAbstract:
Extended Abstract Zinc coatings applied to steels may corrode in place of substrate to form protective oxides that protect the substrate. However, in humid environments, the protective oxide does not form properly, what is aggravated by the chloride ions presence. Many cyclic accelerated corrosion tests use high concentrations of chloride ions, resulting in the formation of soluble zinc salts, which are removed from the surface, which may lead to results that do not adequately represent performance of galvanized steel. This study aimed to analyze the causes of this behavior. For this purpose, a coated and uncoated steel was evaluated after pretreatment and painting in furniture industry, it was submitted to a cyclic accelerated corrosion test (NBR 10821) and 13 months in natural industrial atmosphere. It was verified that the coated steel showed practically no corrosion or paint peeling after the industrial test. In contrast, the paint peeling of galvanized steel was higher than that of uncoated steel after accelerated testing with high concentrations of chloride ions. Therefore, it is concluded that the correct evaluation of the corrosion resistance of galvanized steels depends fundamentally on the selection of tests that represent conveniently the material application conditions and if the results are not correctly interpreted will lead to erroneous conclusions.
2
Karlsdottir, Sigrun Nanna, Adolph Manadao Bravo, Gifty Oppong Boakye, Halldór Pálsson, and Andri Stefánsson. "Corrosion Testing of Coatings in Simulated ORC Geothermal Heat Exchanger Environment." In CONFERENCE 2023. AMPP, 2023. https://doi.org/10.5006/c2023-19444.
Full textAbstract:
Abstract Materials used in utilizing geothermal energy can be subjected to corrosion and scaling due to elevated temperature and fluid chemistry in the systems. This can result in high costs associated with materials and decreased efficiency in the production of geothermal power. Carbon steel materials are often used in heat exchangers due to good heat transfer properties but have poor anti-corrosion and -scaling properties. Thus, corrosion-resistant alloys with less favorable heat transfer properties but better anti-corrosion and -scaling properties are commonly used in geothermal power production. In this study coatings developed in the GeoHex project to enhance corrosion, scaling and heat transfer performance were tested in experimental Organic Rankin Cycle (ORC) heat-exchanger (HE) test equipment to evaluate the anti-corrosion and -scaling properties in heat transfer experiments. Different types of coatings developed for simulated brine and working fluid sides of the ORC HE were tested at RT to 80°C in hot brine with a low temperature boiling working fluid. These included electroless nickel coating, and amorphous metal coatings. The microstructure and chemical composition of the coatings were analysed before and after the tests in hot brine with Scanning Electron Microscope and X-Ray Energy Dispersive Spectroscopy to evaluate the durability of the coatings. The morphology and hydrophobic properties (wettability) were also examined with roughness and water contact angle (WCA) measurements. The coatings were observed to increase the WCA in most of the coatings, however, higher angles were measured after the LT test influenced by the morphology of the coatings after the exposure. The findings showed that the Ni-P-PTFE samples were highly hydrophobic and had better corrosion properties in hot brine compared to the Amorphous coatings due to cracks and peeling of the coating peeling in the Amorphous samples. The Ni-P-PTFE coating was concluded to be the most promising Geo-Hex coating material candidate tested in hot brine in the simulated ORC-HE environment.
3
O’Malley, Cindy, Chuck Duffin, and Steve Revnew. "Use of Atlas Test Cells to Assess the Performance of Coatings with Varied Permeance over Concrete Masonry Units (CMU)." In SSPC 2012 Greencoat. SSPC, 2012. https://doi.org/10.5006/s2012-00035.
Full textAbstract:
Abstract The permeance of coatings applied to the walls of Single Wythe concrete masonry units (CMU) can affect the long term performance of the coating system, especially after multiple repaints. This paper describes the results of a study to determine if the Atlas Cell Test (NACE TM0174/ASTM C868) can be modified to evaluate the performance of individual coating systems based upon permeance. Coating systems with permeance (WVP US perm ratings) from &lt; 10 perms to &gt; 60 perms were used in the research. The goal of the test program is to establish a protocol that can eventually be used to determine the number of times that a given system can be repainted before the reduction in permeance causes concerns with blistering or peeling.
4
Park, Chung Seo, Sung Mo Son, Chil Seok Shin, Mong Kyu Chung, and Kwang Ki Baek. "Effects of Surface Preparation Methods and Protective Coating Types on the Performance of Erection Joint Weld Seams in Water Ballast Tanks." In CORROSION 2007. NACE International, 2007. https://doi.org/10.5006/c2007-07004.
Full textAbstract:
Abstract Ship's water ballast tanks are exposed to the extremely corrosive environments due to immersion or non-immersion by cyclic loading/unloading of ballast water. For cargo oil tankers, the temperature of the ballast tanks walls adjacent to the cargo oil tanks can reach up to 60℃ and drop to 0℃ in the cold sea causing higher hostility of corrosive environment. In ageing ships, coating failures, such as cracking, peeling off, are often observed in the areas of erection jointed weld seams and other stress concentrated areas. To improve coating performance of these vulnerable areas, the current surface preparation methods and coating materials for the erection jointed seams of water ballast tanks are evaluated. Three types of surface preparation tool were tested and evaluated in terms of surface profile and subsequent coating performances, such as long term corrosion resistance, crack resistance, rust creepage, cathodic disbondment test, etc. From these results, optimum surface preparation methods and proper coating materials for erection jointed seams of water ballast tanks are proposed.
5
Park, Cheon Kil, Ki Hong Kim, Ho Il Lee, and Seong Kyun Lee. "Lessons Learned from Winter Season Application of Epoxy/Urethane Coating System for the Offshore Structure." In CORROSION 2004. NACE International, 2004. https://doi.org/10.5006/c2004-04006.
Full textAbstract:
Abstract Offshore structures employed in deep sea water are expected to endure about 25 years without any dry docking repair, requiring rather strict control of surface preparation, protective coating application and inspection, and so on. Recently, these facilities have been built in the Far East of Asia region. Consequently, it’s unavoidable to overcoat epoxy with epoxy or urethane under the winter condition. In the initial stage of the coating application, there were lots of coating problems such as peeling-off and retarded coating drying. In this study, we have evaluated two coating materials widely used for offshore structures to establish the coating procedures providing high quality and better workability under low temperature condition. We also investigated a main cause of adhesion failure for epoxy-urethane coating by developing a test method for detection of coating defect. This procedure enabled us to apply the coating system successfully on our offshore yard. Based on the comparative study on several different epoxy coating system, and proper solutions to reduce painting defects were provided for successful application at the yard.
6
Rosas, Omar, Oscar Garcia, Jose Hernandez, Carlos Girault, and Mark Mulvihill. "Effect of Cycling Torqueing on the Corrosion Resistance and Nut-Factor Consistency of Coated High-Strength Steel Bolting." In CORROSION 2019. NACE International, 2019. https://doi.org/10.5006/c2019-13268.
Full textAbstract:
Abstract Almost every piece of equipment in the Oil and Gas industry requires the use of bolted joints due to numerous advantages they offer; protecting them against corrosion is mandatory. Most anti-corrosion coatings on bolts don’t offer a consistent tightening, as their nut factor changes, the nut factor relates the bolt’s installation torque to the tension required to tighten the bolt; maintaining a consistent nut factor would solve problems such as over-torqueing and overstress, avoiding leaks and failures. Organic coatings have historically suffered from flaking and peeling when torqued, hence, metallic coatings such as Nickel-Cobalt electroplating may offer a more reliable performance. To compare the performance of coatings used in bolted joints simulating service conditions, cyclic torqueing was applied to fasteners with different coatings and the nut-factor and corrosion resistance were evaluated. B7M bolts and 2HM nuts were coated with: 1) No coating, 2) Ni-Co Electroplating, 3) Zn Electroplated + PTFE, and 4) TSA + PTFE. All samples were tested with no lubricant, and two different commercial lubricants. Electrochemical and environmental corrosion tests were performed before and after torqueing. Ni-Co electroplating showed a better performance compared to the other coatings, offering the highest nut factor consistency and the lowest corrosion rate.
7
Tator, Kenneth B. "A New Cyclic Test Apparatus for Material Evaluation." In CORROSION 1989. NACE International, 1989. https://doi.org/10.5006/c1989-89041.
Full textAbstract:
Abstract A unique patented laboratory test chamber has been devised to simulate environmental exposure. This device automatically cycles test specimens through alternating immersion and heat-UV exposures. The difference between the new accelerated test chamber and existing test cabinets is that the failure and defects obtained on the new chamber are more visually representative of failures that occur in actual field environments. Rusting, chalking, blistering, cracking, and peeling failures have been successfully duplicated. NACE defines corrosion as the deterioration of a material under the influence of an environment. The environment is undefined, and is infinitely variable. It may consist of predominantly weathering, with exposure to sun, rain, and temperature change. Northern environments will include freeze/thaw, and chemical environments are contaminated by chemical ion species. Materials exposed in these naturally occurring environments deteriorate under these and perhaps other influences. The best test to establish a material's resistance to a given environment is exposure in that environment over a sufficiently long period of time. Unfortunately, such "natural" environmental corrosion testing is prohibitively expensive and time-consuming. Furthermore, relatively small changes in a given environment (such as differences in wet time, chloride ion, sulfate, oxygen concentrations, temperature, etc.) may cause failure of a material that otherwise would be considered "corrosion resistant". Thus, no one naturally occurring environment is the same as any other. However, certain of the more predominating environmental influences may be sufficient to generally characterize an environment. As an example, a "marine" environment connotates damp salt air and sea water wetting. This obviously is different than an inland environment, where such influences are not present. Similarly, an "immersion" environment is different than an atmospheric environment. A "high temperature" environment may induce material failures that otherwise would not occur at ambient temperatures. Accordingly, many material researchers, in order to reduce the time necessary to evaluate materials in an environment, have tried to characterize the most influential attributes of various environments, and incorporate them in laboratory testing devices to accelerate "natural" failures. The simulated environmental variables are chosen in order to be reasonably representative of the predominating influences in the actual environment. For most organic materials (plastics, fabrics, wood, coatings, etc.), the influence of water and solar radiation are probably the most detrimental. In immersion or chemical environments, water and the presence of the various chemical species are the most influential. In most cases, it is believed that a dynamic condition is more severe than a stable condition. For example, alternate wetting and drying is more severe than either the completely dry or a completely wet environment. Similarly, thermal cycling (alternately hot and cold) is more detrimental than a stable temperature condition (either hot or cold). Finally, the ability to easily adjust or change the predominating environmental influences in order to more closely simulate a dynamic condition, or to provide failure acceleration, is essential. All of these considerations led to the design of a new environmental test cabinet for material evaluation.
8
Kawahara, Yuuzou, Toshio Sakurada, Yuuji Nakagawa, Hiroki Kamakura, Masaharu Kira, and Yukio Imaizumi. "Life Evaluation of ZrO2 / Ni Base Alloy Plasma-Jet Coating Systems in High-Efficiency WTE Boiler Superheaters." In CORROSION 2004. NACE International, 2004. https://doi.org/10.5006/c2004-04535.
Full textAbstract:
Abstract In order to improve the durability and cost performance of superheater in high efficiency WTE boiler, new Ni base alloy/YSZ dual coating systems using plasma-jet spray technology has been developed, and then the life of these coatings sprayed on 500°C/9.8MPa high-efficiency WTE boiler superheater was evaluated by the long term field corrosion test. Three kinds of coating layer of: alloy 625/YSZ, NiCrSiB alloy/YSZ and Cr3C2·NiCr sprayed by 100kW plasma-jet system both on site and on shop were installed in tertialy and secondary superheater having high metal temperature of 450 ~ 500°C, and exposed for more than 1.3 years. As the results of the field corrosion test, alloy 625/YSZ and NiCrSiB alloy/YSZ coatings with inorganic sealant showed excellent durability more than 1.5 years compaired with conventional NiCrSiB alloy HVOF system in tertialy superheater. Based on the detail investigation of cut-off tube samples, A durability of each coatings reduce with increase in corrosivity of combustion gas. YSZ and inorganic sealant were clarified to work as a penetration barrier for corrosive components in deposits to coating/base metal interface. Especially, in soot blower affected position, Cr3C2·NiCr layer sprayed in secondary superheater peeled off by thermal cyclic factor after four months exposure, while large corrosion prevention effect was observed in Ni base alloy/YSZ layer regardless of partial peeling-off of YSZ layer. An application of Ni base alloy/YSZ coatings for actual boiler is expected in the future.
9
Xu, Chun, and Shuhui Li. "Research on Peeling Properties of Galvannealed Coatings." In ASME 2007 International Manufacturing Science and Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/msec2007-31038.
Full textAbstract:
Galvannealed coatings are so quite hard and brittle that they are difficult to peel off from their substrates by conventional peeling tests. A special test to tear galvannealed coatings, based on asymmetry 90°peel test, is experimentally investigated. Rectangle shapes of specimens are asked in the test. Specimens have 100mm in length and 25mm in width. They were pulled apart in Zwick instron testing machine at 5mm/min. peeling stress of galvannealed coatings was measured in this test. Morphology of cross-section sample was observed by SEM. The difference of microstructure phases on sample’s surface before and after peel test was analyzed by XRD. Galvannealed coatings are consisted of δ-, Γ- and Γ1 -phases. Gamma (Γ + Γ1) phases are located in interface of coating and substrate. Delta phase is next to gamma phase. After the coatings are peeled off, there are only gamma phase on the fractured surfaces of substrate side. The results show the coatings’ fracture occurs along interface layer of coating and substrate.
10
Strus, Mark C., Arvind Raman, Luis Zalamea, R. Byron Pipes, and Cattien V. Nguyen. "Nanomechanics of Peeling Studied Using the Atomic Force Microscope." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34570.
Full textAbstract:
Through adaptation of an atomic force microscope, we have developed a peel test at the micro- and nanoscale level that has the capability of investigating how long flexible nanotubes, nanowires, nanofibers, proteins, and DNA adhere to various substrates. This novel atomic force microscopy (AFM) peeling mode extends existing AFM “pushing” and “pulling” force spectroscopies by offering practical knowledge about the complex interplay of nonlinear flexure, friction, and adhesion when one peels a long flexible molecule or nanostructure off a substrate. The static force peeling spectroscopies of straight multiwalled carbon nanotubes suggest that a significant amount of the total peeling energy is channeled into nanotube flexure. Meanwhile dynamic force spectroscopies offer invaluable information about the dissipative physical processes involved in opening and closing a small “crack” between the nanotube and substrate.
Reports on the topic "Testa peeling"
1
STUDY ON MECHANICAL PROPERTIES OF STAINLESS STEEL PLATE SHEAR WALL STRENGTHENED BY CORRUGATED FRP. The Hong Kong Institute of Steel Construction, 2022. http://dx.doi.org/10.18057/icass2020.p.305.
Full textAbstract:
In this paper, the mechanical properties of stainless steel plate shear walls reinforced with fiber reinforced polymer (FRP) of corrugated sections were studied. Two scaled FRP-stainless steel plate shear wall specimens were designed and subjected to the monotonic horizontal load. FRPs in the form of corrugated and flat sections were respectively used to reinforce the embedded steel plates of the steel plate shear wall. The test results show that the failure mode of flat FRP reinforced steel plate shear wall is mainly the peeling of the FRP, while the failure mode of corrugated FRP reinforced steel plate shear wall is mainly the tensile fracture of the FRP. The out-of-plane deformation of steel plate reinforced with corrugated FRP can be effectively restrained. The maximum bearing capacity of the two specimens is 97.96 kN and 106.32 kN respectively. The yield load of the specimen with corrugated FRP is increased by 16.5%, the ultimate bearing capacity is increased by 9.3% and the stiffness is increased by 68%.