scholarly journals Corrosion Initiation Behavior of Thermal Control Oxidation Film of LA103Z Alloy

2021 ◽  
Vol 8 ◽  
Author(s):  
Chen Wen ◽  
Jingying Bai ◽  
Kuo Zhao ◽  
Qingxin Cui ◽  
Baocheng Jiao ◽  
...  
Keyword(s):  
Early Stage ◽  
Thermal Control ◽  
Sample Surface ◽  
Treatment Method ◽  
Chemical Oxidation ◽  
Corrosion Mechanism ◽  
Electrochemical Characteristics ◽  
Corrosion Initiation ◽  
Corrosion Behaviors ◽  
Last Stage

The magnesium lithium thermal control oxidation is a commonly used conductive anti-corrosion treatment method for aerospace. The corrosion behaviors of thermal control oxidation films for LA103Z alloys were studied in 3.5% NaCl solution. The corrosion characteristics with different immersion time were characterized by using scanning electron microscopy, energy spectroscopy, and electrochemical methods. The results showed that the corrosion of Mg-Li alloy with chemical oxidation film starts from pitting corrosion, gradually expands in depth in the early stage, forms corrosion holes, and then gradually develops into river-like morphology. In the last stage, the increasing corrosion products slow down the corrosion rate and gradually covers the entire sample surface. The corrosion product mainly consists of MgO, LiF, and MgCl2. Combined with the electrochemical characteristics, the corrosion mechanism was investigated.

scholarly journals Corrosion Behaviors of the Eutectic Structure in Zn-Al-Mg Alloy Coated Steel in Chloride Containing Aqueous Environment

2020 ◽  
Vol 58 (9) ◽  
pp. 610-616
Author(s):  
Jae-Won Lee ◽  
Se-Young Oh ◽  
Bora Park ◽  
Min-Suk Oh ◽  
Sung Jin Kim
Keyword(s):  
Coating Layer ◽  
Early Stage ◽  
Galvanic Corrosion ◽  
Salt Spray ◽  
Eutectic Structure ◽  
Mg Alloy ◽  
Aqueous Environment ◽  
Corrosion Mechanism ◽  
Coated Steel ◽  
Corrosion Behaviors

To clearly understand the effect of the eutectic structure in the Zn-Al-Mg alloy coating on the corrosion behaviors in chloride containing aqueous environments, a bulk Zn-MgZn<sub>2</sub> sample was fabricated by diffusion bonding process, and a variety of experiments, such as electrochemical polarization and galvanic corrosion measurements, salt spray tests, and cyclic corrosion tests, were carried out. This study revealed that the corrosion potential values of MgZn<sub>2</sub> and Zn samples exposed to a 5 wt.% of NaCl solution were approximately -1.5 and -1 VSCE, respectively, and the MgZn<sub>2</sub> showed a higher corrosion current density than Zn at the early stage of corrosion. The continued dissolution of MgZn<sub>2</sub> phase from the eutectic structure in the coating layer provides not only sacrificial protection, but also environmental conditions for the co-formation of two types of corrosion products (simonkoleite (Zn<sub>5</sub>(OH)<sub>8</sub>Cl<sub>2</sub>·H<sub>2</sub>O) and hydrotalcite (ZnAl<sub>2</sub>(OH)<sub>6</sub>Cl<sub>2</sub>·H<sub>2</sub>O)) which have an inhibiting effect on the outer surface. The formation areas and kinetics of the two products on the coating surface were different, and they were greatly dependent upon the types of eutectic structures in the coating layer. Based on the results, a modified anti-corrosion mechanism of Zn-Al-Mg alloy coated steel sheet in chloride containing aqueous environment was proposed.

scholarly journals Analysis of Activation Process of Carbon Black Based on Structural Parameters Obtained by XRD Analysis

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Sang-Min Lee ◽  
Sang-Hye Lee ◽  
Jae-Seung Roh
Keyword(s):  
Carbon Black ◽  
Early Stage ◽  
Structural Parameters ◽  
Xrd Analysis ◽  
Activation Process ◽  
Co2 Gas ◽  
Carbon Black Surface ◽  
Black Surface ◽  
Last Stage ◽  
Pore Properties

In the present study, carbon black activated by CO2 gas was examined through XRD analysis, especially with regard to changes in its structural parameters. Based on the results, its activation process was thoroughly analyzed. The activation process was controlled by isothermally activating the carbon black inside a reaction tube through which CO2 gas flowed. With this approach, the degree of activation was varied as desired. At an early stage of the activation process, the amorphous fraction on the carbon black surface was preferentially activated, and later the less-developed crystalline carbon (LDCC) region inside the carbon black particles started to be activated. The latter process was attributable to the formation of pores inside the carbon black particles. As the activation process proceeded further, the more-developed crystalline carbon (MDCC) region started to be activated, thereby causing the pores inside the carbon black particles to grow larger. At the last stage of the activation process, La was found to be decreased to about 40 Å. This implied that the edges of the graphite crystals had been activated, thus causing the internal pores to grow and coalesce into larger pores. Activated conductive Super-P with enhanced pore properties is expected to have wide applications.

Study onCorrosion Behaviour of AISI 316L Stainless Steel Treated with Air Cold Plasma

2009 ◽  
Vol 79-82 ◽  
pp. 1119-1122
Author(s):  
Qi Wang ◽  
Hong Ren Wang ◽  
Cong Jie Gao ◽  
Feng Liu
Keyword(s):  
Stainless Steel ◽  
Cold Plasma ◽  
316L Stainless Steel ◽  
Electrochemical Impedance ◽  
Ferric Chloride Solution ◽  
Sample Surface ◽  
Corrosion Mechanism ◽  
Plasma Oxidation ◽  
Aisi 316L Stainless Steel ◽  
Potentiodynamic Polarization Curves

Pitting resistance of air cold plasma-oxidation 316L stainless steel was evaluated by exposing the specimens into a ferric chloride solution. The results indicate that the pitting resistance of plasma-oxidized specimens improved obviously. Potentiodynamic polarization curves were measured to study its corrosion behavior. The corrosion mechanism was also interpreted by electrochemical impedance spectroscopy (EIS) and Auger electron spectroscopy (AES).The results reveal that the oxide layer formed by the plasma treatment is much thicker than that without treatment and is double-deck structure, which leads to the change of EIS characteristic of sample surface.

Increase of the content of QP47 (a desiccation-associated nuclear protein) in embryo cells during maturation of pea seeds

1994 ◽  
Vol 4 (4) ◽  
pp. 421-429 ◽  
Author(s):  
Donato Chiatante ◽  
Paola Brusa
Keyword(s):  
Cell Proliferation ◽  
Nuclear Protein ◽  
Early Stage ◽  
Seed Maturation ◽  
Radicle Elongation ◽  
Embryo Cells ◽  
Last Stage ◽  
Pea Seeds ◽  
Metabolic Activities

AbstractA nuclear protein (QP47) is synthesized during the last stage of seed maturation when the embryo cells start to dehydrate and enter a condition of metabolic quiescence. This protein is localized in the nucleoplasm surrounding the chromosomes. The correlation existing between the synthesis of QP47 and arrest of cell proliferation, suggests that the presence of this protein in the nucleus could influence its metabolic activities. This hypothesis is supported by the fact that degradation of this protein precedes resumption of cell proliferation during the early stage of radicle elongation.

scholarly journals Understanding the Public’s Emotions about Cancer: Analysis of Social Media Data

2020 ◽  
Vol 17 (19) ◽  
pp. 7160
Author(s):  
Seul Ki Park ◽  
Hyeoun-Ae Park ◽  
Jooyun Lee
Keyword(s):  
Social Media ◽  
Cancer Survivors ◽  
Hair Loss ◽  
Early Stage ◽  
Treatment Method ◽  
Cancer Type ◽  
Social Media Data ◽  
Factors Affecting ◽  
Gastrointestinal Problems ◽  
Media Data

Cancer survivors suffer from emotional distress, which varies depending on several factors. However, existing emotion management programs are insufficient and do not take into consideration all of the factors. Social media provides a platform for understanding the emotions of the public. The aim of this study was to explore the relationship between the public’s emotions about cancer and factors affecting emotions using social media data. We used 321,339 posts on cancer and emotions relating to cancer extracted from 22 social media channels between 1 January 2014, and 30 June 2017. The factors affecting emotions were analyzed using association rule mining and social network analysis. Hope/gratitude was the most frequently mentioned emotion group on social media followed by fear/anxiety/overwhelmed, sadness/depression/loneliness/guilt, and anger/denial. Acute survival stage, treatment method, and breast cancer were associated with hope/gratitude. Early stage, gastrointestinal problems, fatigue/pain/fever, and pancreatic cancer were associated with fear/anxiety/overwhelmed. Surgery, hair loss/skin problems, and fatigue/pain/fever were associated with sadness/depression/loneliness/guilt. Acute survival stage and hair loss/skin problems were associated with anger/denial. We found that emotions concerning cancer differed depending on the cancer type, cancer stage, survival stage, treatment, and symptoms. These findings could guide the development of tailored emotional management programs for cancer survivors that meet the public’s needs more effectively.

scholarly journals Study on the Microstructure of the Pinctada martensii Pearls and Its Significance

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Wenlong Wu ◽  
Liping Zhang ◽  
Zhijun Yang ◽  
Weisheng Hou
Keyword(s):  
Raman Spectra ◽  
Early Stage ◽  
Formation Processes ◽  
High Quality ◽  
Middle Stage ◽  
Pinctada Martensii ◽  
Medium Quality ◽  
Three Stages ◽  
Last Stage ◽  
Crystalline Plane

The results of a microscopy, SEM-EDS, XRD, FTIR, and Raman spectra study of the nacres of the Pinctada martensii pearls from Zhanjiang city, China shows that they can be classified as the high-quality, medium-quality, and inferior-quality pearls. Aragonite, the main inorganic mineralogy in the nacres, was crystallized and grown up in the compartments formed by the silk and radial organic sheets originating from organic matters secreted by the mantle of mollusks. The crystalline orientations of aragonite tablets were changed from the (002), (012) and (102) crystalline plane nets in the early to the (002) crystalline plane net only in the later. The formation processes of the microstructure of the nacres could be divided into three stages. In the early stage, the precursor particles of aragonite nucleated and grew up fast; then, porous aragonite aggregates consisting of the fine aragonite crystals were formed. In the middle stage, the aragonite crystals directionally grew up to form the aragonite tablets and microlayers. The surface of the aragonite tablets and microlayers are rough and few porous, and the edges of the crystals were serrated. In the last stage, the aragonite tablets in the aragonite microlayer mixed perfectly together to form high-quality aragonite layer whose surface was smooth and perfect.

scholarly journals Early Stage in Identifying Autism Spectrum Disorder (ASD) Through Screening and Diagnosis

2018 ◽  
Vol 8 (4) ◽  
pp. 660-663
Keyword(s):  
Screening Tool ◽  
Early Stage ◽  
Treatment Method ◽  
Development Stage ◽  
Autism Spectrum ◽  
Screening Tools ◽  
Early Screening ◽  
Positive Score ◽  
Screening And Diagnosis

The objective of the paper was to evaluate developed screening tools on autism students’ as early detection detect early signs especially on visual for ASD children. The outcomes of early intervention in ASD can be improved but it depends types of the treatment. Method of collecting data was using tool, observation and interview. In design, flowchart and storyboard are produced. While in development stage, learning media and materials are presented with visualization in the form of sound, text, videos and pictures. The results of this study are a positive score and feedback from children with ASD. They are easy to focus in using this tool instead of conventional screening tool. The students really attract to something that related to technology. However, the suggestion of a screening for ASD when concerning from their parents or family. The quality of the instruments and screening procedure are the challenges faced during the process. The advantages of early screening and detection among ASD is very to avoid parents unnecessary worry among parents.

Evaluation of Creep Properties in Soldering Ball by Nanoindentation Creep

2005 ◽  
Author(s):  
Tadahiro Shibutani ◽  
Qiang Yu ◽  
Masaki Shiratori
Keyword(s):  
Chemical Potential ◽  
Early Stage ◽  
Hydrostatic Stress ◽  
Equivalent Stress ◽  
Nanoindentation Test ◽  
Diffusion Creep ◽  
Creep Properties ◽  
Last Stage ◽  
Power Law Creep ◽  
The Relationship

In this paper, the behavior the behavior of creep deformation in low melting point alloy during a nanoindentation test was examined. Nanoindentation creep test was performed for eutectic tin-lead solder ball. Estimated creep exponent from the relationship between hardness and indenter dwell-time decreases as a function of time. The morphology of indented area shows that the transition from the deformation due to the tip in the early stage to another one in the last stage. Each grain near the indenter tip was transformed in the last stage. Stress analysis using a finite element method reveals that relaxation of equivalent stress progresses rapidly and the residual hydrostatic stress is dominant. Then, the gradient of the residual hydrostatic stress affects the chemical potential on grain boundaries and diffusion creep is activated. Therefore, the transition from the power-law creep to diffusion creep takes place during the nanoindentaion creep.

scholarly journals Corrosion Monitoring of Galvanized Steel in Simulated Wet-Dry Cyclic Condition in 0.05 M NaCl Solution

1970 ◽  
Vol 8 (8) ◽  
pp. 76-80 ◽  
Author(s):  
AP Yadav
Keyword(s):  
Corrosion Rate ◽  
Corrosion Potential ◽  
Early Stage ◽  
Ac Impedance ◽  
Galvanized Steel ◽  
Corrosion Mechanism ◽  
Corrosion Monitoring ◽  
Cyclic Condition ◽  
Impedance Technique ◽  
Time Of Wetness

The corrosion monitoring of galvanized steel in 1 h wet and 7 h dry cyclic condition in 0.05 M NaCl has been carried out using AC impedance technique. During the wet-dry cycles, the polarization resistance, Rp, and solution resistance, Rs, were continuously monitored. The instantaneous corrosion rate of the coating was estimated from the obtained Rp-1 and time of wetness (TOW) was determined from the Rs values. The corrosion potential, Ecorr, was measured twice a day during the immersion period of wet-dry cycle. The corrosion was accelerated by the wet-dry cycles in the early stage followed by a decrease in the final stage of wet-dry cycle. The corrosion potential shifted to more negative direction for the first 8 cycles due to dissolution of air formed oxide. A gradual shift in the corrosion potential with the progress of corrosion in the later stage of the wet-dry cycle was observed due to deposition of corrosion products. The corrosion mechanism of galvanized steel is discussed based on the results of corrosion monitoring and corrosion potential variation. Key words: Atmospheric corrosion; Galvanized steel; AC Impedance; Corrosion rate. DOI: 10.3126/sw.v8i8.3855 Scientific World Vol.8(8) 2010 pp.76-80

The Role of Leukocyte-Platelet-Rich Fibrin in Promoting Wound Healing in Diabetic Foot Ulcers

2021 ◽  
pp. 153473462110528
Author(s):  
Yuqi Wang ◽  
Xiaotao Wang ◽  
Rong Chen ◽  
Liuwei Gu ◽  
Desen Liu ◽  
...  
Keyword(s):  
Wound Healing ◽  
Diabetic Foot ◽  
Early Stage ◽  
Treatment Method ◽  
Foot Ulcers ◽  
Control Group ◽  
Diabetic Foot Ulcers ◽  
External Application ◽  
Traditional Treatment ◽  
Platelet Rich Fibrin

To explore the effect of leukocyte-platelet-rich fibrin (L-PRF) on promoting wound healing in diabetic foot ulcers. A total of 42 patients with diabetic foot ulcers at our hospital from January 2017 to July 2020 were retrospectively analyzed. A control group and a PRF group were established. The two groups of patients underwent debridement. In the platelet-rich fibrin (PRF) group, autologous L-PRF was used to cover ulcer wounds. One time each week, Vaseline gauze was used to cover the ulcer wounds. In contrast, the control group was treated with the external application of mupirocin ointment and recombinant human epidermal growth factor gel (yeast). Two times each week, the sterile Vaseline gauze was covered with a bandage. Both groups were treated for 5 weeks. The wound recovery of the two groups was observed. During the early stage of treatment (first and second weeks) for diabetic foot ulcers, the wound healing rate was significantly better with L-PRF treatment than traditional treatment. For later-stage treatment (third to fifth weeks), the overall cure rate was higher with L-PRF than the traditional treatment method. L-PRF can effectively promote wound healing in diabetic foot ulcers.

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