Effect of benzotriazole on the existing pits of copper tube in fire sprinkler system.

In this paper, two leaking tubes were investigated among copper tubes injected with 200 and 400 ppm benzotriazole after 8 years of usage. The electrochemical tests were conducted in simulated pit-out and pit-in environments (i.e., regions outside and inside of the pit) to determine the effect of benzotriazole on the propagation of an existing pit. The electrochemical analysis results showed that 200 and 400 ppm benzotriazole exhibit relatively lower inhibition efficiency in an acidic simulated pit-in environment because of the difficulty of forming a protective film and the benzotriazole cationization.

Communication competence and resilience are modifiable factors for burnout of operating room nurses in South Korea.

BACKGROUND: Burnout negatively impacts the personal and professional life of nurses. Job stress and resilience have been determined to be associated with nurse burnout. Given the importance of communication competence in operating room (OR) nurses, the associations of job stress, resilience, and communication competence with burnout have not been examined. PURPOSE: To determine the relationships of job stress, resilience, and communication competence to burnout of OR nurses in South Korea. METHODS: This was a cross-sectional, descriptive study of 146 OR nurses. A series of self-reported questionnaires was used to assess job stress, resilience, communication competence, and burnout. Pearson correlation coefficient and a hierarchical linear regression were used for data analysis. RESULTS: Communication competence was correlated with resilience (r = 0.65, p < .001) and burnout (r = -0.44, p < .001), and resilience was correlated with burnout (r = -0.48, p < .001). Resilience (ß = -0.22, p = .027) and communication competence (ß = -0.33, p < .001) were associated with burnout of OR nurses in a hierarchical linear regression (F = 6.28, p < .001). CONCLUSIONS: Increased resilience and communication competence were associated with lower burnout of perioperative nurses. To prevent and reduce burnout of OR nurses, it is necessary to develop and implement a program targeting for communication competence and resilience. IMPLICATIONS FOR NURSING MANAGEMENT: Nurse leaders should provide programs fostering communication competence and resilience to OR nurses and encourage them to actively participate in such job trainings.

Comparison of Hydrogen Embrittlement Susceptibility of Different Types of Advanced High-Strength Steels.

This study investigated the hydrogen embrittlement (HE) characteristics of advanced high-strength steels (AHSSs). Two different types of AHSSs with a tensile strength of 1.2 GPa were investigated. Slow strain rate tests (SSRTs) were performed under various applied potentials (Eapp) to identify the mechanism with the greatest effect on the embrittlement of the specimens. The SSRT results revealed that, as the Eapp increased, the elongation tended to increase, even when a potential exceeding the corrosion potential was applied. Both types of AHSSs exhibited embrittled fracture behavior that was dominated by HE. The fractured SSRT specimens were subjected to a thermal desorption spectroscopy analysis, revealing that diffusible hydrogen was trapped mainly at the grain boundaries and dislocations (i.e., reversible hydrogen-trapping sites). The micro-analysis results revealed that the poor HE resistance of the specimens was attributed to the more reversible hydrogen-trapping sites.

Localized Corrosion Occurrence in Low-Carbon Steel Pipe Caused by Microstructural Inhomogeneity.

In this study, the cause of failure of a low-carbon steel pipe meeting standard KS D 3562 (ASTM A135), in a district heating system was investigated. After 6 years of operation, the pipe failed prematurely due to pitting corrosion, which occurred both inside and outside of the pipe. Pitting corrosion occurred more prominently outside the pipe than inside, where water quality is controlled. The analysis indicated that the pipe failure occurred due to aluminum inclusions and the presence of a pearlite inhomogeneous phase fraction. Crevice corrosion occurred in the vicinity around the aluminum inclusions, causing localized corrosion. In the large pearlite fraction region, cementite in the pearlite acted as a cathode to promote dissolution of surrounding ferrite. Therefore, in the groundwater environment outside of the pipe, localized corrosion occurred due to crevice corrosion by aluminum inclusions, and localized corrosion was accelerated by the large fraction of pearlite around the aluminum inclusions, leading to pipe failure.

Relationships among basic psychological needs, organizational commitment, perceived authentic leadership and turnover intention in Korean nurses: A cross-sectional study.

AIM: This study determined the relationships of satisfaction and frustration with basic psychological needs, organizational commitment, perceived authentic leadership and turnover intention in nurses in South Korea. BACKGROUND: Minimizing nurse turnover is essential for improving the quality of nursing care and patient safety. METHODS: This was a cross-sectional, correlational pilot study of 216 nurses at a university hospital in South Korea. Data were collected with a self-report questionnaire, from 1 to 15 September 2020. Collected data were analysed using SPSS 24.0. RESULTS: Multiple regression analysis revealed that clinical experience (3 to 5 years, ß = 2.35, p = .019; 5 to 10 years, ß = 2.23, p = .026), subjective workload (severe, ß = 2.10, p = .036; extreme, ß = 2.84, p = .005), psychological needs frustration (ß = 0.35, p < .001), organizational commitment (ß = -0.17, p = .011) and perceived authentic nurse leadership (ß = -0.14, p = .030) were found to have significant effects on nurses' turnover intention. CONCLUSIONS: The results suggest that it is necessary to create a transparent work environment based on authentic leadership and consider individual frustrations with regard to basic psychological needs and organizational commitments. IMPLICATIONS FOR NURSING MANAGEMENT: This study offers a new approach to reducing nurses' turnover. A strategy is needed for efficient nursing staffing management to assist with reduction of nurses' turnover intentions.

Effect of Imidazole as Corrosion Inhibitor on Carbon Steel Weldment in District Heating Water.

Many research studies have been conducted on the corrosion inhibition performance of imidazole in acidic environments such as in the piping of a petrochemical plant. However, there has been no study on the effect of imidazole in alkaline conditions such as a local district water heating environment. Therefore, in this study, the effect of imidazole as a corrosion inhibitor on carbon steel weldment was investigated in alkaline district heating water. Inhibition efficiency and electrochemical properties were investigated by potentiodynamic polarization test and electrochemical impedance spectroscopy. As the concentration of imidazole increased up to 500 ppm, inhibition efficiency increased up to 91.7%. At 1000 ppm, inhibition efficiency decreased. Atomic force microscopy showed that surface coverage of imidazole at 1000 ppm is lower than that of imidazole at 500 ppm. X-ray photoelectron spectroscopy showed that with 500 ppm of imidazole, the amount of pyrrole type interaction is 4.8 times larger than pyridine type interaction. At 1000 ppm of imidazole, the amount of pyridine type interaction is 3.49 times larger than pyrrole type interaction. Depending on the concentration of imidazole, the ratio of interaction between carbon steel and imidazole affected inhibition efficiency.

Effect of Cr on Aqueous and Atmospheric Corrosion of Automotive Carbon Steel.

This study investigated the effect of Cr alloying element on the corrosion properties of automotive carbon steel (0.1C, 0.5Si, 2.5Mn, Fe Bal., composition given in wt.%) in aqueous and atmospheric conditions using electrochemical measurement and cyclic corrosion tests. Three steels with 0, 0.3, and 0.5 wt.% Cr were studied by electrochemical impedance spectroscopy. Polarization resistance (Rp) of 0.3 Cr and 0.5 Cr steels was higher than that of 0 Cr steel, and the Rp also increased as the Cr content increased. Therefore, Cr increases the corrosion resistance of automotive carbon steel immersed in a chloride ion (Cl-)-containing aqueous solution. In the cyclic corrosion test results, Cl- was concentrated at the metal/rust interface in all of the steels regardless of Cr content. The Cl- was uniformly concentrated and distributed on the 0 Cr steel, but locally and non-uniformly concentrated on the Cr-added steels. The inner rust layer consisted of ß-FeOOH containing Cl- and Cr-goethite, while the outer rust layer was composed of amorphous iron oxyhydroxide mixed with various types of rust. FeCl2 and CrCl3 are formed from the Cl- nest developed in the early stage, and the pitting at CrCl3-formed regions are locally accelerated because Cr is strongly hydrolyzed to a very low pH.

Effect of Benzotriazole on the Localized Corrosion of Copper Covered with Carbonaceous Residue.

Carbonaceous residues on copper pipes during the manufacturing process are known to be one of the main causes of pitting corrosion on copper pipes. This study examined the corrosion-inhibiting effect of benzotriazole (BTA) on C12200 copper pipes with carbonaceous film in synthetic tap water. In the absence of BTA, localized corrosion mechanisms due to galvanic corrosion, crevice corrosion, and oxygen-concentration cell were proposed in the boundary part of the carbonaceous film on the copper through X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) analyses. Electrochemical tests showed that BTA inhibits corrosion by forming Cu-BTA complexes on all over the copper surface where carbonaceous film is present. BTA mitigates galvanic corrosion and crevice corrosion at the boundary of the carbonaceous film and suppresses the formation of oxygen-concentration cells through the formation of a Cu-BTA complex.

Comparison of Interface Pressures and Subjective Comfort of Pressure-Relieving Overlays on the Operating Table for Healthy Volunteers.

(1) Background: Pressure ulcers in the hospital setting occurring within 72 h after surgery are called perioperative pressure injuries. The aim of this study was to provide data for the prevention of perioperative pressure injuries following the use of pressure-relieving overlays by measuring the interface pressures and subjective comfort. (2) Methods: This study is based on a repeated measures design. The subjects included 30 healthy volunteers aged 18 to 57 years. Interface pressures of the sacrum and both heels were measured in the supine position, and the subjective comfort was evaluated with visual analog scale after applying polyurethane foam, gel pad, and egg crate foam for relief. (3) Results: The pressures in the sacrum and both heels were the lowest with polyurethane foam, and the subjective comfort was the highest. (4) Conclusions: Inexpensive polyurethane foam with satisfactory pressure relief is recommended as an overlay for surgical patients.

Factors Influencing the Preventive Practice of International Students in South Korea against COVID-19 during the Pandemic.

As the novel coronavirus disease (COVID-19) spreads worldwide, quarantine guidelines are being constantly updating to prevent the transmission of this virus. Regardless of which country international students live in, they might receive limited crucial quarantine guidelines from that country's government. The purpose of this study was to identify factors influencing the preventive practice of international students in South Korea during the COVID-19 pandemic. This was a cross-sectional descriptive study. Data were collected from international students in three universities from July 10 to July 31 in 2020. A total of 261 international students participated in the survey, using an online questionnaire. Data were analyzed by independent t-test, one-way ANOVA, Pearson correlation coefficients, and multiple regression analysis. Preventive practice during the COVID-19 pandemic was affected by duration of stay in Korea (ß = -0.21, p < 0.001), attitudes (ß = 0.22, p = 0.001), and trust in Korea's quarantine system (ß = 0.33, p < 0.001). This study showed that attitudes and trust in the quarantine system could affect personal preventive practice during the outbreak of a highly contagious disease such as COVID-19.

Optimization of Pickling Solution for Improving the Phosphatability of Advanced High-Strength Steels.

This study investigated the optimum pickling conditions for improving the phosphatability of advanced high-strength steel (AHSS) using surface analysis and electrochemical measurements. To remove the SiO2 that forms on the surface of AHSS, 30 wt.% NH4HF2 was added to the pickling solution, resulting in a significant reduction in the amount of SiO2 remaining on the surface of the AHSS. The phosphatability was improved remarkably using HNO3 concentrations higher than 13% in the pickling solution. Furthermore, phosphate crystals became finer after pickling with a HNO3-based solution rather than a HCl-based solution. Electrochemical impedance spectroscopy (EIS) data indicated that the corrosion resistance of AHSS subjected to HNO3-based pickling was higher than that of AHSS subjected to HCl-based pickling. Fluorine compounds, which were involved in the phosphate treatment process, were only formed on the surface of steel in HNO3-based solutions. The F compounds reacted with the phosphate solution to increase the pH of the bulk solution, which greatly improved the phosphatability. The phosphatability was better under HNO3-based conditions than a HCl-based condition due to the fineness of the phosphate structure and the increased surface roughness.

Effects of a breastfeeding coaching program on growth and neonatal jaundice in late preterm infants in South Korea.

PURPOSE: This study examined the effects of a breastfeeding coaching program for mothers on growth and neonatal jaundice in late preterm infants (LPIs). METHODS: This was a quasi-experimental study (non-randomized intervention) with a time-series design. The study was conducted among 40 LPIs who were admitted to the neonatal intensive care unit of a university hospital in Daegu, South Korea. In the order of admission, the first 21 infants were assigned to the experimental group, and 19 were assigned to the control group. The intervention program consisted of home- based and web-based practical breastfeeding support education for mothers across a total of 5 sessions. Infant growth was measured using body weight, length, and head circumference, and neonatal jaundice was assessed using transcutaneous bilirubin levels. RESULTS: The likelihood of breastfeeding for infants in the experimental group at 4 weeks after discharge was the same as on the day of discharge, whereas it steadily decreased in the control group. There were significant differences in head circumference between the groups. However, weight, length, and transcutaneous bilirubin levels did not show a significant group-time interaction. CONCLUSION: A formal breastfeeding coaching program should be considered in clinical settings and at home within the first few weeks postpartum.

Effects of Corrosion on Mechanical Properties of Welded Carbon Steel Pipe in District Heating Water.

This study examined the effect of corrosion on mechanical properties of welded carbon steel pipe in district heating water. To evaluate the corrosion properties, potentiodynamic tests were conducted and a galvanostatic test was used to accelerate corrosion. Tensile tests and microstructure observations were performed to figure out the degradation of the corroded region, and stress intensity factors were calculated. As a result of the potentiodynamic tests, welded carbon steel pipe showed uniform corrosion and the total charge was calculated. Using the galvanostatic test, the current density at the equivalent aging time was applied to the specimens. The tensile tests showed that according to corrosion damages, mechanical properties were degraded due to corrosion. Through the microstructure observations and calculations of stress intensity factors, the corrosion of the welded carbon steel pipe induced the degradation of mechanical properties. The mode of fracture was changed from ductile to brittle fracture with increasing aging time.

Effects of quantitative electroencephalography based neurofeedback training on autonomous regulations in patients with alcohol use disorder.

PURPOSE: The study investigated whether neurofeedback training can normalize the excessive high-beta and low alpha waves indicative of hyperarousal, and subsequently improve autonomous regulation based on the self-determination theory in alcohol use disorders. METHODS: A nonequivalent control group pretest-posttest design was used. Data were collected using self-report questionnaires from 36 Korean inpatients who met the Alcohol Use Disorder Identification Test in Korea criteria. Data were collected from quantitative electroencephalography to assess alpha (8-12 Hz) and high-beta (21-30 Hz) waves for hyperarousal. The questionnaires included Basic Psychological Need Satisfaction scales that assessed autonomy, competence, and relatedness, and the Alcohol Abstinence Self-Efficacy Scale and Treatment Self-Regulation Questionnaire. The experimental group underwent 10 sessions of neurofeedback training over four weeks. Data were analyzed using the chi-squared, Mann-Whitney U, and Wilcoxon signed-rank tests. RESULTS: In the experimental group, the alpha wave was increased in 15 of 19 sites and high-beta waves were decreased in 15 of 19 sites, but this difference was not significant. However, high-beta waves were increased in 15 of 19 sites in the control group, with seven sites (Fz, Cz, Pz, Fp2, F4, C4, and P4) showing significant increases. The experimental group showed a significant increase in basic psychological need satisfaction, alcohol abstinence self-efficacy, and self-regulation compared with the control group. CONCLUSIONS: Neurofeedback training is recommended for improving autonomous regulation in alcohol use disorder as a nursing intervention. However, for significantly attenuating hyperarousal through brain wave correction, it may be necessary to increase the number of neurofeedback sessions.