Investigation of color and anticorrosive properties of pigments in the Fe-Al-Mg-O-H system by the simplex lattice method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Liliya Frolova ◽  
Tatyana Butyrina
Keyword(s):  
Protective Effect ◽  
Dissociation Constants ◽  
Polarization Curves ◽  
Lattice Method ◽  
Corrosion Properties ◽  
Content Type ◽  
Measurement Results ◽  
Simplex Lattice ◽  
Co Precipitation ◽  
Potentiodynamic Method

Purpose The purpose of this paper is to study the patterns of formation of anti-corrosion properties, the development of compositions for pigments by using the method of co-precipitation and subsequent heat treatment. Design/methodology/approach To obtain co-precipitated hydroxides, aqueous solutions of salts were used. The conditions of synthesis varied according to the following parameters: the nature of the starting salts of metals; and the ratio of metal cations. The anticorrosive activity of the pigments was evaluated by the potentiodynamic method, by comparing the anodic and cathodic polarization curves, and calculated potentials and corrosion currents on the basis of regions of Tafel on curves. Polarization curves were obtained by using Potentiostat/Galvanostat/ZRA Gamry, which connected to the PC, and by using the program Gamry Framework. The measurement results were processed by using the method of simplex-lattice planning. X-ray diffractograms of pigments were recorded on a DRON – 2.0 diffractometer (monochromatic copper radiation with a nickel filter). Findings The paper deals with the results of research the dependence of colour characteristics and anticorrosion properties of synthesized compositions on their nature and composition. The presence of aluminium cations leads to the formation of solid solutions of ferrum and aluminium oxyhydroxides. Originality/value The main technological properties of pigments are determined by the anionic and cationic composition. Colour characteristics are determined by the cation-chromophore. The anti-corrosive properties of non-calcined pigments are determined to a greater extent by the presence of the formed hydroxyl ions and the composition of the compounds. The greatest protective effect is observed when using double compounds of metals, the dissociation constants of which differ significantly. The protective effect is mainly determined by the slowdown of the anode process. Anions containing aluminium atoms accelerate the corrosion processes.

Rheology effect and enhanced thermal conductivity of diamond/metakaolin geopolymer fabricated by direct ink writing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yushen Wang ◽  
Wei Xiong ◽  
Danna Tang ◽  
Liang Hao ◽  
Zheng Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Diamond Powder ◽  
Thermal Imager ◽  
Corrosion Properties ◽  
Content Type ◽  
Sensor Material ◽  
Direct Ink Writing ◽  
Diamond Particles ◽  
Before And After

Purpose Traditional simulation research of geological and similar engineering models, such as landslides or other natural disaster scenarios, usually focuses on the change of stress and the state of the model before and after destruction. However, the transition of the inner change is usually invisible. To optimize and make models more intelligent, this paper aims to propose a perceptible design to detect the internal temperature change transformed by other energy versions like stress or torsion. Design/methodology/approach In this paper, micron diamond particles were embedded in 3D printed geopolymers as a potential thermal sensor material to detect the inner heat change. The authors use synthetic micron diamond powder to reinforced the anti-corrosion properties and thermal conductivity of geopolymer and apply this novel geopolymer slurry in the direct ink writing (DIW) technique. Findings As a result, the addition of micron diamond powder can greatly influence the rheology of geopolymer slurry and make the geopolymer slurry extrudable and suitable for DIW by reducing the slope of the viscosity of this inorganic colloid. The heat transfer coefficient of the micron diamond (15 Wt.%)/geopolymer was 50% higher than the pure geopolymer, which could be detected by the infrared thermal imager. Besides, the addition of diamond particles also increased the porous rates of geopolymer. Originality/value In conclusion, DIW slurry deposition of micron diamond-embedded geopolymer (MDG) composites could be used to manufacture the multi-functional geological model for thermal imaging and defect detection, which need the characteristic of lightweight, isolation, heat transfer and wave absorption.

Comparison of flutter calculation methods based on ground vibration test result

2019 ◽  
Vol 91 (3) ◽  
pp. 466-476
Author(s):  
Wojciech Chajec
Keyword(s):  
Low Cost ◽  
Ground Vibration ◽  
Control Surface ◽  
Vibration Test ◽  
Problem Solution ◽  
Lattice Method ◽  
Mass Model ◽  
Content Type ◽  
Strip Theory ◽  
Flutter Analysis

PurposeA low-cost but credible method of low-subsonic flutter analysis based on ground vibration test (GVT) results is presented. The purpose of this paper is a comparison of two methods of immediate flutter problem solution: JG2 – low cost software based on the strip theory in aerodynamics (STA) and V-g method of the flutter problem solution and ZAERO I commercial software with doublet lattice method (DLM) aerodynamic model and G method of the flutter problem solution. In both cases, the same sets of measured normal modes are used. Design/methodology/approachBefore flutter computation, resonant modes are supplied by some non-measurable but existing modes and processed using the author’s own procedure. For flutter computation, the modes are normalized using the aircraft mass model. The measured mode orthogonalization is possible. The flutter calculation made by means of both methods are performed for the MP-02 Czajka UL aircraft and the Virus SW 121 aircraft of LSA category. FindingsIn most cases, both compared flutter computation results are similar, especially in the case of high aspect wing flutter. The Czajka T-tail flutter analysis using JG2 software is more conservative than the one made by ZAERO, especially in the case of rudder flutter. The differences can be reduced if the proposed rudder effectiveness coefficients are introduced. Practical implicationsThe low-cost methods are attractive for flutter analysis of UL and light aircraft. The paper presents the scope of the low-cost JG2 method and its limitations. Originality/valueIn comparison with other works, the measured generalized masses are not used. Additionally, the rudder effectiveness reduction was implemented into the STA. However, Niedbal (1997) introduced corrections of control surface hinge moments, but the present work contains results in comparison with the outcome obtained by means of the more credible software.

Shielded metal arc welding of AISI 409M ferritic stainless steel: study on mechanical, intergranular corrosion properties and microstructure analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sachin Ambade ◽  
Chetan Tembhurkar ◽  
Awanikumar P. Patil ◽  
Prakash Pantawane ◽  
Ravi Pratap Singh
Keyword(s):  
Corrosion Behavior ◽  
Heat Input ◽  
Intergranular Corrosion ◽  
Arc Welding ◽  
High Heat ◽  
Shielded Metal Arc Welding ◽  
Corrosion Properties ◽  
Content Type ◽  
Welding Heat Input ◽  
Metal Arc Welding

Purpose The purpose of this study is on AISI 409 M ferritic stainless steel (FSS) which is developing a preferred choice for railway carriages, storage tanks and reactors in chemical plants. The intergranular corrosion behavior of welded SS 409 M has been studied in H2SO4 solution (0.5 M) with the addition of NH4SCN (0.01 M) with different heat input. As this study is very important in context of various chemical and petrochemical industries. Design/methodology/approach The microstructure, mechanical properties and intergranular corrosion properties of AISI 409 M FSS using shielded metal arc welding were investigated. Shielded metal arc welding with different welding current values are used to change the heat input in the joints resulted in the microstructural variations. The microstructure of the welded steel was carefully inspected along the width of the heat-affected zone (HAZ) and the transverse-section of the thin plate. Findings The width of heat affected zone (3.1,4.2 and 5.8 mm) increases on increasing the welding heat input. Due to change in grain size (grain coarsening) as HAZ increased. From the microstructure, it was observed that the large grain growth which is dendritic and the structure become finer to increase in welding heat input. For lower heat input, the maximum microhardness value (388HV) was observed compared with medium (351 HV) and higher heat input (344 HV), which is caused by a rapid cooling rate and the depleted area of chromium (Cr) and nickel (Ni). The increase in weld heat input decreases tensile strength, i.e. 465 MPa, 440 MPa and 418 MPa for low, medium and high heat input, respectively. This is because of grain coarsening and chromium carbide precipitation in sensitized zone and wider HAZ. The degree of sensitization increases (27.04%, 31.86% and 36.08%) to increase welding heat input because of chromium carbide deposition at the grain boundaries. The results revealed that the higher degree of sensitization and the difference in intergranular corrosion behavior under high heat input are related to the grain growth in the HAZ and the weld zone. Originality/value The study is based on intergranular corrosion behavior of welded SS 409 M in H2SO4 solution (0.5 M) with the addition of NH4SCN (0.01 M) with different heat input which is rarely found in literature.

Corrosion characterization of Sn-Zn solder: a review

2019 ◽  
Vol 31 (1) ◽  
pp. 52-67 ◽  
Author(s):  
Muhammad Firdaus Mohd Nazeri ◽  
Muhamad Zamri Yahaya ◽  
Ali Gursel ◽  
Fakhrozi Cheani ◽  
Mohamad Najmi Masri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Alloy System ◽  
Future Research ◽  
Corrosion Properties ◽  
Content Type ◽  
Characterization Techniques ◽  
Recent Developments ◽  
Potentiostatic Polarization

PurposeThe purpose of this paper is to review and examine three of the most common corrosion characterization techniques specifically on Sn-Zn solders. The discussion will highlight the configurations and recent developments on each of the compiled characterization techniques of potentiodynamic polarization, potentiostatic polarization and electrochemical impedance spectroscopy (EIS).Design/methodology/approachThe approach will incorporate a literature review of previous works related to the experimental setups and common parameters.FindingsThe potentiostatic polarization, potentiodynamic polarization and EIS were found to provide crucial and vital information on the corrosion properties of Sn-Zn solders. Accordingly, this solder relies heavily on the amount of Zn available because of the inability to produce the intermetallic compound in between the elements. Further, the excellent mechanical properties and low melting temperature of the Sn-Zn solder is undeniable, however, the limitations regarding corrosion resistance present opportunities in furthering research in this field to identify improvements. This is to ensure that the corrosion performance can be aligned with the outstanding mechanical properties. The review also identified and summarized the advantages, recent trends and important findings in this field.Originality/valueThe unique challenges and future research directions regarding corrosion measurement in Sn-Zn solders were shown to highlight the rarely discussed risks and problems in the reliability of lead-free soldering. Many prior reviews have been undertaken of the Sn-Zn system, but limited studies have investigated the corrosive properties. Therefore, this review focuses on the corrosive characterizations of the Sn-Zn alloy system.

Investigation of liquidus surface in Pb-Sn-Te system by simplex lattice method

1979 ◽  
Vol 46 (4) ◽  
pp. 487-490 ◽  
Author(s):  
Z. Muszynski ◽  
O.I. Davarashvili ◽  
N.G. Riabtsev ◽  
A.P. Shotov
Keyword(s):  
Liquidus Surface ◽  
Lattice Method ◽  
Simplex Lattice

scholarly journals Interleukin-10 (IL-10) Produced by Mutant Toxic Shock Syndrome Toxin 1 Vaccine-Induced Memory T Cells Downregulates IL-17 Production and Abrogates the Protective Effect against Staphylococcus aureus Infection

2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Kouji Narita ◽  
Dong-Liang Hu ◽  
Krisana Asano ◽  
Akio Nakane
Keyword(s):  
Staphylococcus Aureus ◽  
T Cells ◽  
Infectious Diseases ◽  
Protective Effect ◽  
Toxic Shock Syndrome ◽  
Long Term Memory ◽  
Toxic Shock ◽  
Content Type ◽  
Memory Phase ◽  
Toxic Shock Syndrome Toxin

ABSTRACT Development of long-term memory is crucial for vaccine-induced adaptive immunity against infectious diseases such as Staphylococcus aureus infection. Toxic shock syndrome toxin 1 (TSST-1), one of the superantigens produced by S. aureus, is a possible vaccine candidate against infectious diseases caused by this pathogen. We previously reported that vaccination with less toxic mutant TSST-1 (mTSST-1) induced T helper 17 (Th17) cells and elicited interleukin-17A (IL-17A)-mediated protection against S. aureus infection 1 week after vaccination. In the present study, we investigated the host immune response induced by mTSST-1 vaccination in the memory phase, 12 weeks after the final vaccination. The protective effect and IL-17A production after vaccination with mTSST-1 were eliminated because of IL-10 production. In the presence of IL-10-neutralizing monoclonal antibody (mAb), IL-17A production was restored in culture supernatants of CD4+ T cells and macrophages sorted from the spleens of vaccinated mice. Vaccinated mice treated with anti-IL-10 mAb were protected against systemic S. aureus infection in the memory phase. From these results, it was suggested that IL-10 produced in the memory phase suppresses the IL-17A-dependent vaccine effect through downregulation of IL-17A production.

Corrosion behaviors of X70 steel under direct current interference

2019 ◽  
Vol 66 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Jun Wang ◽  
Zili Li ◽  
Gan Cui ◽  
JianGuo Liu ◽  
Chuanping Kong ◽  
...  
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Soil Solution ◽  
Direct Current ◽  
Polarization Curves ◽  
Solution Ph ◽  
Corrosion Morphology ◽  
Content Type ◽  
Tafel Polarization ◽  
Corrosion Behaviors

Purpose The purpose of this paper is to study the corrosion behaviors of X70 steel under direct current (DC) interference at 0-1,200 A/m2 in simulated soil solution. Design/methodology/approach The Tafel polarization curves of X70 steel under DC interference were tested using electrochemical method, the corrosion rate was calculated using weight-loss method and the change in steel surface was analyzed by optical microscopy. Findings The results showed that E-I polarization curves under 200-1,200 A/m2 interference were linear; with an increase in the DC density, the corrosion potential of X70 steel shifted positively, solution pH after the weight-loss tests increased and corrosion rate increased linearly. A mathematical relationship between polarization resistance Rp and current density was established. Corrosion morphology indicated that pitting corrosion and crevice corrosion occurred on the X70 steel under DC interference in simulated soil solution. Originality/value All tests were conducted at a relative higher DC density (200-1,200 A/m2). The linear fitting method is proposed to fit data of Tafel polarization curves under DC interference. This study provides guidelines for safe operation of X70 steel pipelines.

Effects of post-weld heat treatments on the microstructure, mechanical and corrosion properties of gas metal arc welded 304 stainless steel

2020 ◽  
Vol 17 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Taiwo Ebenezer Abioye ◽  
Igbekele Samson Omotehinse ◽  
Isiaka Oluwole Oladele ◽  
Temitope Olumide Olugbade ◽  
Tunde Isaac Ogedengbe
Keyword(s):  
Stainless Steel ◽  
Welded Joint ◽  
Grain Structure ◽  
304 Stainless Steel ◽  
Aisi 304 Stainless Steel ◽  
Corrosion Properties ◽  
Aisi 304 ◽  
Content Type ◽  
Post Annealing ◽  
Weld Heat

Purpose The purpose of this study is to determine the effects of post-annealing and post-tempering processes on the microstructure, mechanical properties and corrosion resistance of the AISI 304 stainless steel gas metal arc weldment. Design/methodology/approach Gas metal arc welding of AISI 304 stainless steel was carried out at an optimized processing condition. Thereafter, post-annealing and post-tempering processes were performed on the weldment. The microstructure, mechanical and electrochemical corrosion properties of the post-weld heat treated samples, as compared with the as-welded, were investigated. Findings The as-welded joint was characterized with sub-granular grain structure, martensite formation and Cr-rich carbides precipitates. This made it harder than the post-annealed and post-tempered joints. Because of slower cooling in the furnace, the post-annealed joint contained Cr-rich carbides precipitates. However, the microstructure of the post-tempered joint is more refined and significantly devoid of the carbide precipitates. Post-tempering process improved the elongation (∼23%), tensile (∼10%) and impact (∼31%) strengths of the gas metal arc AISI 304 stainless steel weldment, while post-annealing process improved the elongation (∼20%) and impact strength (∼72%). Owing to the refined grain structure and significant elimination of the Cr-rich carbide precipitates at the joint, the post-tempered joint exhibited better corrosion resistance in 3.5 Wt.% NaCl solution than the post-annealed and the as-welded joints. Originality/value The appropriate post-weld heat treatment that enhances microstructural homogeneity and quality of the AISI 304 gas metal arc welded joint was determined.

Synthesis of pigments in Fe2O3-Al2O3-CoO by co-precipitation method

2017 ◽  
Vol 46 (5) ◽  
pp. 356-361 ◽  
Author(s):  
Liliya Frolova ◽  
Alexander Pivovarov ◽  
Tatyana Butyrina
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Treatment Temperature ◽  
Precipitation Method ◽  
Colour Properties ◽  
X Ray Diffraction ◽  
Content Type ◽  
Composition Property ◽  
Yellow Pigments ◽  
Co Precipitation

Purpose The purpose of this work is to study the patterns of pigment colour formation and to develop metal compositions for obtaining spinels using the precipitation and heat treatment methods. Design/methodology/approach Precursor materials were prepared using co-precipitation method. Phase composition of pigments were determined by X-ray diffraction. Colour of pigments was determined spectrophotometry. Modelling of colour formation was performed using simplex method. Planning in the future to carry out full synthesis of pigments of blue, red and yellow colours. Findings The paper deals with the results of theoretical and experimental research on the synthesis pigments of blue, red and yellow colours based on Fe-Co-Al-O spinel. The influence of the chromophore cation content and the heat treatment temperature on optical and colour characteristics of pigments were studied. Originality/value The resulting composition-property diagrams make it possible to evaluate the effect of chromophore cations and heat treatment on the colour formation for Fe2O3-Al2O3-CoO system. Crystal-phase composition of the pigments is installed and its relationship with the optical colour characteristics. That makes it possible carry out targeted synthesis of pigments blue, red and yellow colours in further. The phase composition of pigments and its relationship with optical and colour properties has been established thus enabling the directed synthesis of blue, red and yellow pigments.

Design of a high gain equilateral triangular microstrip patch antenna array (ETMPAA) on FR4 substrate using microstrip feed

2016 ◽  
Vol 35 (5) ◽  
pp. 1538-1549 ◽  
Author(s):  
Manikandan Alagarsamy ◽  
Uma Maheswari Sangareswaran ◽  
P. Dhanaraj
Keyword(s):  
High Gain ◽  
Band 3 ◽  
Maximum Efficiency ◽  
Design System ◽  
Impedance Bandwidth ◽  
Patch Antennas ◽  
Content Type ◽  
Feeding Technique ◽  
Measurement Results ◽  
Microstrip Feed

Purpose The purpose of this paper is to discuss and analyze a microstrip feed equilateral triangular microstrip array antenna (ETMPAA) that is proposed for S band (3 GHz) applications. Design/methodology/approach The ETMPAA comprises three equilateral triangular patches with equal distance. The size of the antenna is 49.4 mm (0.0494 m)×18.4 mm (0.184 m). The proposed antenna has been designed by etching triangular shape structure on glass epoxy substrate (FR4). Findings The simulated result shows that ETMPAA has the impedance bandwidth of 900 MHz and the bandwidth can be achieved by controlling the gap between the patch antennas. The antenna is fed by microstrip feeding technique. Design of an antenna using advanced design system (ADS), based on finite element methods (FEM) has been used to analyze and optimize the antenna. Based on the measurement results an antenna proposed with maximum efficiency and maximum gain. Originality/value This paper fulfils an identified need to study a microstrip feed ETMPAA is proposed for S band (3 GHz) applications.

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