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• The physical and thermal properties and flame retardancy of PET fibers in SC−CO2 media were evaluated. • Each PET sample was prepared with DOPO from 1% to 9% o.w.f. concentration was treated. • PET fibers treated with DOPO concentration of 5% or higher showed excellent flame retardancy of 29 % or higher LOI. • The DOPO-treated PET fiber maintained its flame-retardant performance even after washing up to 50 times. • There was hardly any deterioration in the physical properties of PET treated with DOPO. An eco-friendly flame-retardant process was employed to impart flame-retardant characteristics to polyethylene terephthalate (PET) fibers by treating these with a phosphorus-based flame retardant, 910-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), using supercritical CO 2 as a solvent. DOPO was applied to the PET fibers without any other additives. The concentration of DOPO was changed from 1% o.w.f. to 9% o.w.f., and it was applied for 60 min at 120 °C and 25 MPa. As the DOPO concentration increased, many particles attached to the surface, creating a non-smooth surface. The phosphorous component increased with an increase in the amount of DOPO applied to the PET fiber, without the deterioration of physical properties such as tensile strength and elongation at break. When the sample was treated with 5% o.w.f DOPO, the char length decreased significantly, and the after-flame time was not observed. The limiting oxygen index (LOI) of ≥29 indicated excellent flame-retardant performance. Washing up to 50 times did not deteriorate the flame-retardant performance, as indicated by the retention of the LOI value of ≥29. Therefore, the PET fibers treated with DOPO using supercritical CO 2 showed excellent washing durability and flame retardancy. [ABSTRACT FROM AUTHOR]

• An analysis of the industrial accident prevention effect of the hazardous machine safety certification system was performed. • The necessity of the safety certification system was confirmed using three statistical methods. • Surveys, industrial accident data analysis, field surveys, and expert interviews were conducted. • It was confirmed that the safety certification system has a positive effect on industrial accident prevention. • The safety certification system must ensure efficiency by considering the safety policy and industrial environment of each country. The "4th industrial revolution" is accelerating changes in technology, industry, and machinery, and the "Internet of everything" (IoE) requires comprehensive integration of people and machines. Despite the development of these technologies, fatal accidents continue to occur due to malfunctions of dangerous machinery, so the importance of the safety certification system is increasing, but there are few objective analysis data. In this study, the necessity of a safety certification system was confirmed by analyzing the effect of the safety certification system on the prevention effect of industrial accidents in three methods. Based on these analysis results, the industrial accident prevention effect of the current safety certification system and necessary supplementary tasks were derived. Safety certification systems for more than 30 machines and equipment are in operation in South Korea. In this research, the press, crane, catapult, and lift machines most commonly used in industrial fields were analyzed. This study was conducted in five steps: a safety certification system operation status investigation, a survey and interviews, an analysis of dangerous machinery and equipment accidents, focus group interviews, and study of the direction of safety certification systems in consideration of recent IoE developments. As a result of the analysis, various opinions were presented on the safety certification system by subject, and it was found that it was necessary to prepare supplementary measures for the advancement of the safety certification system advancement, expand its field applicability, and improve the efficiency of safety certification. [ABSTRACT FROM AUTHOR]

• Industrial accidents caused by equipment (machinery) occur in various forms, such as jamming, cutting, and crushing. • Many fatal accidents, mainly due to jamming, occurred in non-routine work. • Non-routine work accounted for 56.5% of jamming accidents, which were caused by seven major equipment. • The maintenance, repair, inspection, replacement, adjustment, cleaning, and removal of foreign substances were classified into non-routine work. • The main cause was that the work was done without stopping the operation of equipment. Industrial accidents caused by equipment (machinery) occur in various forms, such as jamming, cutting, and crushing. Among them, various precise and dangerous machines and equipment in the manufacturing industry continue to be used despite the several regulations established and efforts made. This study analysed the accidental deaths caused through jamming or crushing during non-routine work, in the manufacturing industry from 2014 to 2018. The analysis was conducted on 203 cases of non-routine work among 359 fatalities. The maintenance, repair, inspection, replacement, adjustment, cleaning, and removal of foreign substances were classified into non-routine work. Owing to the use of various machineries and equipment in the manufacturing industry, specialised knowledge is required for their maintenance and management, as well as daily work. Since various types of equipment (machinery) are used in the manufacturing industry, expertise to safely use equipment is required to prevent industrial accidents that may occur during work using this equipment. In South Korea, where heavy industry and chemical industry have developed, many accidental deaths due to non-routine work have been reported under these conditions. Non-routine work accounted for 56.5% of jamming accidents, which were caused by seven major equipment such as conveyor, mixer, food manufacturing equipment, crushing machine, injection moulding machine, press machine, and industrial robot. In addition, the employees did not fully comply with the basic safety rules, such as not turning off the power or using lockout-tagout (LOTO), during the maintenance work. Finally, various measures were proposed to prevent accidental deaths resulting non-routine work. [ABSTRACT FROM AUTHOR]

• This study investigates chemical accidents that occurred between January 2008 and June 2018 in South Korea. • 76.1% of chemical accidents were caused by human error in South Korea. • Large-scale enterprises experienced the largest number of industrial accidents during maintenance work. • Fire and explosion accounted for 72% of all CPI accidents, of which 32.4% were ignited by static electricity. • Chemical accidents mostly occurred in storage tanks, chemical reactors, and mixing tanks. Major accidents in the chemical process industries are relatively rare, but the resulting harm to workers, property loss, business interruption, and the environment are very serious. This study investigates chemical accidents that occurred between January 2008 and June 2018 in South Korea, and proposes ways to prevent similar accidents from occurring by analyzing the main causes of these accidents. Nine core concepts were drawn from the analyses comparing chemical accidents in South Korea: (1) current casualties by type of worker, (2) how the scale of the enterprise affects the disaster, (3) chemical accidents by type of occurrence, (4) analysis of ignition sources, (5) chemical accidents by CPI facilities, (6) human and technical error, (7) chemical accidents by work situation, (8) chemical accidents by non-compliance of process safety management (PSM) standards, and (9) chemical accidents by hazardous materials. Although there have been no recent occurrences of large chemical accidents since 2017 due to various factors, our results indicate that the past frequency of such accidents area serious concern in South Korea. Understanding the root causes of these accidents can help to prevent the recurrence of similar accidents and to strengthen preventative measures in chemical plants. [ABSTRACT FROM AUTHOR]

Chemical disinfectants, widely used as antibacterial criteria, have been extensively studied for the past few decades by being divided into three levels, and γ-irradiation is also currently recognized as an outstanding antibacterial technique. However, there is no correlation between the strengths of the two methods. Antibacterial efficacy and tensile strengths of various natural and synthetic polymers inoculated with Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) were analyzed using SEM, FT-IR, and tensile strength instruments. High and medium-level chemical disinfectants showed a similar effect to 2 kGy and 0.5 kGy of γ-irradiation doses for antibacterial analysis. In addition, the degradation of material properties through tensile strength analysis was observed only with high-level chemical disinfectants. When the correlation of high-level chemical disinfectants and γ-irradiation doses was compared through analysis of tensile strength, high-level chemical disinfectants exhibited a result equivalent to a 0.5 kGy γ-irradiation dose for synthetic polymers, while natural polymers were observed to be similar to 5 kGy for cotton and 50 kGy for wool, respectively. [ABSTRACT FROM AUTHOR]

Supercapacitors have attracted considerable attention because they can store more energy than conventional capacitors and can have higher power densities than batteries. In this study, microwave irradiation was used for the rapid and facile synthesis of mesoporous RGO@(Co,Mn) 3 O 4 oxide nanosheets as an electrode material for supercapacitor applications. The as-prepared electrode exhibited a high capacitance of 1004 F g −1 at 3 mV s −1 in a 6 M KOH electrolyte solution. Moreover, the electrode showed good specific retention and high Coulombic efficiency of 81.6% and 96.9%, respectively, after 3000 charge-discharge cycles. The electrode also exhibited a high energy density of 53 Wh kg −1 (at power density of 500 W kg −1 ) and high power density 5000 W kg −1 (at energy density of 27 Wh kg −1 ). Overall, the RGO@(Co,Mn) 3 O 4 electrode showed very promising results for supercapacitor applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various elongation rates (50%, 100%, and 125%) improved physicochemical properties. • C-Cl peak disappears and C = C peak appears depending on the effect of carbonization. • CPVC carbon fiber with an elongation of 125% showed maximum mechanical properties. • CPVC carbon fiber with a tensile strength of 1.83 GPa can be applied to the automotive industry. CPVC fibers were prepared using a low-cost chlorinate polyvinyl chloride (CPVC) precursor using wet spinning, and various elongation rates were applied (0%, 50%, 100%, and 125%) to improve the physicochemical properties. CPVC fibers were carbonized in a nitrogen atmosphere to prepare CPVC carbon fibers, and physicochemical changes were observed by applying the same elongation rates. The CPVC fiber changed from aliphatic to aromatic carbon chemically, such as C-Cl peak intensity disappeared after carbonization and C = C bonding peak was newly discovered. After CPVC carbonization, CPVC carbon fiber, which has an elongation of 125%, has the maximum mechanical properties (tensile strength of up to 1.83GPa, modulus of 172GPa) by inducing a change in the carbon fiber structure, so it can be applied to the automotive industry in the future. [ABSTRACT FROM AUTHOR]

• Physiochemical property changes of PET fibers after supercritical (SC) CO 2 dyeing. • PET crystal orientation and crystal index of fibers increased by adding DR 167 dye. • After SC–CO 2 dyeing, some PET fiber C‒C bonds break and new C=O and C‒O bonds form. • SC–CO 2 -treated PET with DR 167 dye increases fiber tensile strength. ga1 The effects of supercritical CO 2 and C.I. Disperse Red 167 as media on the structural and chemical properties of polyethylene terephthalate (PET) fibers were observed in the supercritical dyeing process of these fibers using numerous methods to predict changes in their physical properties. PET samples were classified into three cases based on the sample preparation and analysis steps. When the PET fibers were treated without C.I. Disperse Red 167 under a supercritical fluid CO 2 solvent at 120 °C and 25 MPa, their crystallinity, orientation, and tensile strength decreased the most among the three cases, whereas when they were treated with C.I. Disperse Red 167 under the same conditions, the three above-mentioned characteristics were relatively improved compared to the scenario without the C.I. Disperse Red 167 treatment. These experimental results provided significant information on the effects of supercritical CO 2 and C.I. Disperse Red 167 on the properties of PET fiber polymers. [ABSTRACT FROM AUTHOR]