scholarly journals Effect of alkaline solutions on the tensile properties of glass-polyester pipes

2011 ◽  
pp. 185-195 ◽  
Author(s):  
Slavisa Putic ◽  
Marina Stamenovic ◽  
Jelena Petrovic ◽  
Marko Rakin ◽  
Bojan Medjo
Keyword(s):  
Tensile Properties ◽  
Construction Materials ◽  
Ammonium Hydroxide ◽  
Longitudinal Direction ◽  
Testing Procedure ◽  
Circumferential Direction ◽  
Process Equipment ◽  
Alkaline Solutions ◽  
Ph Values ◽  
Definite Structure

Construction materials, traditionally used in process equipment, are today successfully replaced by composite materials. Hence, many pipes are made of these materials. The subject of this study was the influence of liquids on the state of stresses and tensile strengths in the longitudinal and circumferential direction of glass-polyester pipes of a definite structure and known fabrication process. These analyses are of great importance for the use of glass-polyester pipes in the chemical industry. The tensile properties (the ultimate tensile strength and the modulus of elasticity) were tested and determined for specimens cut out of the pipes; flat specimens for the tensile properties in the longitudinal direction and ring specimens for the tensile properties in the circumferential direction. First, the tension test was performed on virgin samples (without the influence of any liquid), to obtain knowledge about the original tensile properties of the material composite studied. Subsequently, the specimens were soaked in alkaline solutions: sodium hydroxide (strong alkali) and ammonium hydroxide (weak alkali). These solutions were selected because of their considerable difference in pH values. The specimens and rings were left for 3, 10, 30 and 60 days in each liquid at room temperature. Then, the samples were tested on tension by the standard testing procedure. A comparison of the obtained results was made based on the pH values of the aggressive media in which the examined material had been soaked, as well as based on the original tensile properties and the number of days of treatment. Micromechanical analyses of sample breakage helped in the elucidation of the influence of the liquids on the structure of the composite pipe and enabled models and mechanisms that produced the change of strength to be proposed.

Electrochemical Behavior of Copper in Tetramethyl Ammonium Hydroxide Based Solutions

1999 ◽  
Vol 566 ◽  
Author(s):  
W. H. Huang ◽  
S. Raghavan ◽  
Y. Fang ◽  
L. Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Polyvinyl Alcohol ◽  
Electrochemical Behavior ◽  
Ammonium Hydroxide ◽  
Experimental Results ◽  
Alkaline Solutions ◽  
Tetramethyl Ammonium ◽  
Ph Values ◽  
Tetramethyl Ammonium Hydroxide

An investigation was undertaken to characterize the electrochemical behavior of copper in tetramethyl ammonium hydroxide (TMAH) based solutions. The effect of hydrogen peroxide and abrasion with a polyvinyl alcohol (PVA) brush on the corrosion of copper in alkaline solutions were characterized. Galvanic interactions between copper and tantalum in TMAH as well as in ammonium hydroxide (NH4OH) solutions were investigated. The experimental results have shown that the corrosion of copper in TMAH is lower than that in NH4OH, especially at pH values higher than 10. Even in the presence of hydrogen peroxide, TMAH corrodes copper at a lower rate than NH4OH.

The aquation of cis-Chlorodi(methyl sulphoxide)bisethylenediaminecobalt(III), cis-Chlorodimethylformamidebisethylenediaminecobalt(III), and cis-Chlorodimethylacetamidebisethylenediaminecobalt(III) ions

1966 ◽  
Vol 19 (10) ◽  
pp. 1821 ◽  
Author(s):  
IR Lantzke ◽  
DW Watts
Keyword(s):  
Solvent Molecule ◽  
Chloride Ion ◽  
Side Reaction ◽  
Base Hydrolysis ◽  
Alkaline Solutions ◽  
Replacement Reaction ◽  
Ph Values ◽  
Trigonal Bipyramidal ◽  
Entropy Of Activation ◽  
Solvent Replacement

The aquation of each of three octahedral chloro(solvent)bisethylene- diaminecobalt(III) ions, involving the solvent ligands dimethyl sulphoxide (DMSO), dimethylformamide (DMF), and dimethylacetamide (DMA), has been examined in solutions of different pH. In solutions of pH less than 6, the predominant reaction is replacement of the solvent molecule by water in an SN1 process, involving a trigonal bipyramidal transition state and resulting in a mixture of the trans- and cis- chloroaquo complexes. The slow loss of chloride ion is an accompanying side reaction. In solutions of pH greater than 6 base hydrolysis becomes important, and in alkaline solutions the rate of solvent loss is too fast to measure by conventional techniques. The rate of liberation of chloride ion is also greatly increased with increasing pH. Values of the activation energy, and entropy of activation, are reported for the solvent replacement reaction at a pH of 1.90.

scholarly journals Analyses of Total Alkaloid Extract ofCorydalis yanhusuoby Comprehensive RP × RP Liquid Chromatography with pH Difference

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Wei ◽  
Hongling Shen ◽  
Lijun Wang ◽  
Qingyan Meng ◽  
Wenjie Liu
Keyword(s):  
Liquid Chromatography ◽  
Total Alkaloid ◽  
Ph Value ◽  
Ammonium Hydroxide ◽  
Peak Capacity ◽  
Strong Base ◽  
Retention Factors ◽  
Ph Values ◽  
Dimension Analysis ◽  
Alternative Approach

A comprehensive two-dimensional (2D) reverse phase (RP) liquid chromatography (LC) method is developed for alkaloid analysis. This offline comprehensive 2D method is developed using different pH values. With a pH value of 10.5, most alkaloids appear in the form of neutral molecules possessing high retention factors based on their polarity, while the alkaloid polarity order is changed when the pH value decreased to 3.0. The performance of pH modulated 2D LC is demonstrated with 8 alkaloid standards which resulted in orthogonal separation. The developed method is then applied to total alkaloid separation inCorydalis yanhusuo. The first-dimension separation is carried out using methanol and water containing 1.0% ammonium hydroxide and a strong base-resistant RP column, which afforded a peak capacity of 94. The second-dimension analysis is carried out with a surface positive charge column providing a peak capacity of 205 using a mobile phase consisting of acetonitrile and water with 0.15% formic acid. 2D analyses of total alkaloid extract fromC. yanhusuoafford a total peak capacity of 9090. Sixteen compounds were tentatively identified based on their ultraviolet spectrum and MS/MS analyses. The proposed method provides an alternative approach to achieve high peak capacity for analysis of alkaloid extract.

scholarly journals Corrosion Inhibition Efficiencies of Polymeric Materials on Alloy Steel in Dilute Hydrochloric Acid and Sodium Hydroxide Solutions at Ambient Temperature

2020 ◽  
Vol 7 (2) ◽  
pp. C27-C32
Author(s):  
I.E. Ekengwu ◽  
O.G. Utu ◽  
K.O. Anyanwu
Keyword(s):  
Corrosion Rate ◽  
Ambient Temperature ◽  
Alloy Steel ◽  
Corrosion Inhibition ◽  
High Density Polyethylene ◽  
Inhibition Efficiency ◽  
Polymeric Materials ◽  
High Density ◽  
Alkaline Solutions ◽  
Ph Values

A corrosion control test was conducted on alloy steel, using polymeric coatings (polyurethane, bitumen (medium airing), and high-density polyethylene) in dilute HCl solutions of pH values 4, 7, and 12, respectively for acid, neutral and alkaline solutions at ambient temperature. In the study, Eighty-four coupons of alloy steel were used. The coupons were mechanized, ground, polished, etched with natal, and weighed using a digital weighing balance (Beva 206B). The mass of each coupon was recorded according to the tag number on them. Twenty-one of the coupons were coated with polyurethane, 21 coated with medium curing bitumen (MC), and 21 coated with high-density polyethylene, while 21 were left uncoated. Seven polyurethane-coated samples, bitumen coating, and uncoated coupons were suspended in dilute HCl solutions of pH values 4, 7, and 12. Every week, one sample is taken from each of the solutions, the coatings and the corrosion products were removed, and the coupons were etched with natal. Then the coupons were reweighed, and their masses were recorded in accordance with their tag number. The weight loss per unit area of the coupons, corrosion rate, and percentage corrosion inhibition efficiencies of the coatings was calculated over seven weeks. The results obtained were tabulated and represented graphically. From the results obtained, it is seen that the corrosion inhibition efficiency of polyurethane coatings is higher compared with bitumen and polyethylene. It is also seen from the graphs that the corrosion rate of the coupons is higher in acid, a little bit lower in alkaline, and much lower in neutral solution. It is also observed that the corrosion rates fall with time as the inhibition efficiency also falls with time.

scholarly journals Experimental investigations of the human oesophagus: anisotropic properties of the muscular layer in large deformation

2021 ◽  
Author(s):  
Ciara Durcan ◽  
Mokarram Hossain ◽  
Gregory Chagnon ◽  
Djordje Peric ◽  
Lara Bsiesy ◽  
...  
Keyword(s):  
Strain Rate ◽  
Ex Vivo ◽  
Longitudinal Direction ◽  
Tensile Tests ◽  
Endoscopic Biopsy ◽  
Circumferential Direction ◽  
Experimental Investigations ◽  
Uniaxial Tensile ◽  
Rate Dependency ◽  
Muscular Layer

Technological advancements in the field of robotics have led to endoscopic biopsy devices able to extract diseased tissue from between the layers of the gastrointestinal tract. Despite this, the layer-dependent properties of these tissues have yet to be mechanically characterised using human tissue. In this study, the ex vivo mechanical properties of the passive muscularis propia layer of the human oesophagus were extensively investigated. For this, a series of uniaxial tensile tests were conducted. The results displayed hyperelastic behaviour, while the differences between loading the tissue in both the longitudinal and circumferential directions showcased its anisotropy. The anisotropy of the muscular layer was present at different strain rates, with the longitudinal direction being consistently stiffer than the circumferential one. The circumferential direction was found to have little strain-rate dependency, while the longitudinal direction results suggest pronounced strain-rate-dependent behaviour. The repeated trials showed larger variation in terms of stress for a given strain in the longitudinal direction compared to the circumferential direction. The possible causes of variation between trials are discussed, and the experimental findings are linked to the histological analysis which was carried out via various staining methods. Finally, the direction-dependent experimental data was simulated using an anisotropic, hyperelastic model.

Experimental Study on Tensile Properties of Sugarcane Leaves

2021 ◽  
Vol 37 (4) ◽  
pp. 615-621
Author(s):  
Jing Bai ◽  
Shaochun Ma ◽  
Jiwei Hu ◽  
Yi Wei ◽  
Fenglei Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Tensile Properties ◽  
Tensile Force ◽  
Testing Machine ◽  
Longitudinal Direction ◽  
Leaf Sheath ◽  
List Type ◽  
Factors Affecting ◽  
Strong Linear Correlation ◽  
Tensile Forces

Highlights This article focuses on the tensile properties of sugarcane leaves. The moisture content and sheath diameter were selected as test factors, and the test index was the stalk-leaf connecting force. The load-displacement curves of stalks and leaves were plotted. Two-way ANOVA was also discussed. Abstract . The tensile properties of sugarcane leaves are critical factors affecting the harvesting quality of sugarcane harvesters. Thus, it is important to investigate the tensile properties of sugarcane stalks and leaves. The selected test factors were leaf moisture content and sheath diameter, and the stalk-leaf connecting force was selected as test index. The tests were conducted with two moisture content levels of 15% and 20%, and three sheath diameters of 22, 26, and 30 mm. The stress-strain curves of stalks and leaves were plotted to show how the tensile force varied during the tensile test. The results showed that there was a strong linear correlation between the stalk-leaf connecting force and diameter of leaf sheath, and the connecting force also increased with the increasing moisture content. In addition, leaf tensile forces in longitudinal direction were much larger than in transverse direction. Two-way ANOVA revealed that both of the moisture contents (A) and sheath diameters (B) had significant effects on the stalk-leaf connecting force (p < 0.01), however, the interaction between A and B was not significant (p > 0.1). This study provides a theoretical reference for the design and improvement of crop dividers of sugarcane harvester. Keywords: Moisture content, Sheath diameter, Stalk-leaf connecting force, Sugarcane leaves, Universal testing machine, Tensile properties.

The Effect of Pre-Strain and Strain Aging on Properties of X100 Line Pipe

2013 ◽  
Vol 690-693 ◽  
pp. 2270-2274
Author(s):  
Qiu Rong Ma ◽  
Hong Da Chen ◽  
Yan Hua Li ◽  
He Li
Keyword(s):  
Tensile Strength ◽  
Impact Toughness ◽  
Yield Strength ◽  
Tensile Properties ◽  
Aging Temperature ◽  
Strain Aging ◽  
Longitudinal Direction ◽  
Line Pipe ◽  
Toughness Test ◽  
The Impact

Tensile and impact toughness test on X100 line pipe with different pre-strain at different aging temperature were conducted to study the effect of pre-strain and aging temperature on properties of X100 line pipe. The result shows that yield strength and tensile strength of X100 line pipe would increase significantly with the introduction of pre-strain, while the impact toughness would decrease significantly. Effect of strain aging on tensile properties of X100 line pipe are more significantly. The yield strength, and tensile strength would increase significantly with the introduction of strain aging both transversal and longitudinal direction.

Effect of pH Test-Strip Characteristics on Accuracy of Readings

2017 ◽  
Vol 37 (3) ◽  
pp. 50-58 ◽  
Author(s):  
Norma A. Metheny ◽  
Emily M. Gunn ◽  
Cynthia S. Rubbelke ◽  
Terrilynn Fox Quillen ◽  
Uthayashanker R. Ezekiel ◽  
...  
Keyword(s):  
Nursing Students ◽  
Random Order ◽  
Test Strip ◽  
Testing Procedure ◽  
Buffer Solution ◽  
Convenience Sample ◽  
Test Strips ◽  
Ph Values ◽  
Upper Level ◽  
Ph Buffer

BACKGROUND Little is known about characteristics of colorimetric pH test strips that are most likely to be associated with accurate interpretations in clinical situations. OBJECTIVES To compare the accuracy of 4 pH test strips with varying characteristics (ie, multiple vs single colorimetric squares per calibration, and differing calibration units [1.0 vs 0.5]). METHODS A convenience sample of 100 upper-level nursing students with normal color vision was recruited to evaluate the accuracy of the test strips. Six buffer solutions (pH range, 3.0 to 6.0) were used during the testing procedure. Each of the 100 participants performed 20 pH tests in random order, providing a total of 2000 readings. The sensitivity and specificity of each test strip was computed. In addition, the degree to which the test strips under- or overestimated the pH values was analyzed using descriptive statistics. RESULTS Our criterion for correct readings was an exact match with the pH buffer solution being evaluated. Although none of the test strips evaluated in our study was 100% accurate at all of the measured pH values, those with multiple squares per pH calibration were clearly superior overall to those with a single test square. CONCLUSIONS Test strips with multiple squares per calibration were associated with greater overall accuracy than test strips with a single square per calibration. However, because variable degrees of error were observed in all of the test strips, use of a pH meter is recommended when precise readings are crucial.

Preparation and Tensile Properties of Gasbag with Textile Reinforced Composite Lining

2012 ◽  
Vol 271-272 ◽  
pp. 357-361
Author(s):  
Shuai Wang ◽  
Kun Jiang ◽  
Hui Jun Ning
Keyword(s):  
Brittle Fracture ◽  
Tensile Test ◽  
Tensile Properties ◽  
Longitudinal Direction ◽  
Tensile Fracture ◽  
Reinforced Composite ◽  
New Type ◽  
Textile Reinforced Composite ◽  
Composite Lining

Introducing an gasbag made of novel textile reinforced composite, investigating the tensile properties of this composite through comparison with different directions and speeds tensile test. The research indicates that this composite has preferable tensile properties, and the tensile properties are the same between transverse and longitudinal direction. The tensile fracture is brittle fracture. This result supplies necessary base for application of this new type textile reinforced composite.

Evaluation of Very Dilute Alkaline Solutions for Wafer Cleaning with Megasonic Irradiation

2012 ◽  
Vol 195 ◽  
pp. 181-184 ◽  
Author(s):  
Ji Hyun Jeong ◽  
Bong Kyun Kang ◽  
Min Su Kim ◽  
Hong Seong Sohn ◽  
Ahmed A. Busnaina ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Ammonium Hydroxide ◽  
Alkaline Solutions ◽  
Particle Removal ◽  
Semiconductor Wafer ◽  
Material Loss ◽  
Wafer Cleaning ◽  
Chemical Residues ◽  
Ionic Contamination

In the semiconductor wafer cleaning, ammonium hydroxide based APM (ammonium peroxide mixture) has been widely used to remove particles and organic contaminants [. However as the film thickness and line width of semiconductor structure scales down rapidly, the material losses by etching reaction of alkaline chemicals can cause serious problem in yield loss due to electric failure. The presence of H2O2 could enhance the material loss on silicon wafer. Very dilute alkaline chemicals might be of interest since it could minimize any possible ionic contamination or chemical residues from chemicals as long as we control the surface roughness and particle removal efficiency. Also the characterization of these very dilute alkaline chemicals will be very useful for particle removal in gas dissolved DI water.

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