• Analytical Science and Technology
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• v.20 no.4
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• pp.296-301
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• 2007

Carbon nanofibers (CNFs) are non-microporous materials with a high surface area ($100{\sim}200m^2/g$) and high purity. Therefore, the material has a high potential for use as catalyst support. Activated carbon fibers (ACFs) are of increasing concern with regard to the levels of toxic air pollutants emitted from high-technology industry. Rayon-based CNFs and ACFs was subjected to thermal oxidation under a wide variety of temperature and air conditions to modify the surface properties. Rayon-based CNFs and ACFs were prepared by using thermal chemistry. CNFs were synthesized at temperatures above $600^{\circ}C$ in an air atmosphere and grew with increased temperature and air conditions. After heating at $800^{\circ}C$ for 72 hr, carbonized rayon with ACFs had $2,662m^2/g$ (BET) of surface area and $1.41cm^3/g$ of pore volume. The resulting ACFs had a 99% surface area in which pore size was 10 nm or less, and a 60 % surface area in which pore size was 2 nm or less.

• Korean Journal of Health Psychology
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• v.16 no.1
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• pp.169-187
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• 2011

The present study explored psychosocial characteristics of infants with genital anomalies (GA) and their caregivers against normal controls. Participants were female caregivers and infants between the ages of 6to38months diagnosed with hypospadias(HS;n=103) or cryptorchidism (CR;n=49). Normalcontrols(n=131) were recruited and selected via Internet. Caregivers completed measures on parenting stress, coping style, social support, and infant temperament. Within the GAgroups, HScaregivers reported their greatest parental concerns as infant urination/bodily functioning difficulties whereas CRcaregivers reported worries related to surgical anesthesia issues. Both groups reported concern about their children's potential reproductive problems. Per caregiver report, infants with GA had lower ability to self-soothe. HS infants in particular were perceived as exhibiting greater negative emotion. Compared with controls, HS and CRcaregivers overall employed coping strategies more frequently and had lower interpersonal sensitivity and parental distress. However, HScaregivers emerged as experiencing higher stress when compared to the CRgroup. There were no differences in to tal parenting stress and social support scores between groups. Further, CRcaregivers reported lower levels of family discord than controls. Despite temperament-related differences between infants with GA and normal controls, HS and CRcaregivers reported lower parental distress and greater use of coping skills as compared to controls. Clinical implications are discussed.

• Korea Trade Review
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• v.48 no.1
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• pp.215-241
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• 2023

As competition between ports intensifies, port efficiency has always been a hot topic in the port and shipping economy. Boosting regional and national economies by improving port efficiency and promoting sustainable development of ports is also a concern for port operators and local and national governments. In this situation, this study has the following objectives. First, using panel data from 2010 to 2017, the efficiency of 14 major inland ports along the Yangtze River was analyzed, and changes in port efficiency over time were examined. Second, 14 inland ports are divided into the middle, upper, and lower Yangtze River port groups to compare and review differences in efficiency levels of ports by basin. For the study, we applied a three-step DEA analysis method, which evaluated the pure relative efficiency of the port itself by removing the effects of environmental factors and statistical noise that could affect the efficiency evaluation and presented the results. As a result, it was confirmed that there was a clear difference in the efficiency value of the port between the first-stage and the third-stage efficiency evaluation result. In addition, the downstream ports showed relatively high efficiency compared to the middle and upstream ports.

• Journal of Nutrition and Health
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• v.56 no.5
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• pp.469-482
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• 2023

Purpose: Obesity has emerged as a critical global public health concern as it is associated with and increases susceptibility to various diseases. This condition is characterized by the excessive enlargement of adipose tissue, primarily stemming from an inequity between energy intake and expenditure. The purpose of this study was to investigate the potential of sweet pumpkin powder in mitigating obesity and metabolic disorders in leptin-deficient obese (ob/ob) mice and to compare the effects of raw sweet pumpkin powder (HNSP01) and heat-treated sweet pumpkin powder (HNSP02). Methods: Leptin-deficient obese mice were fed a diet containing 10% HNSP01 and another containing 10% HNSP02 for 6 weeks. Results: The supplementation of ob/ob mice with HNSP01 and HNSP02 resulted in decreased body weight gain, reduced adipose tissue weight, and a smaller size of lipid droplets in the adipose tissue and liver. Furthermore, the ob/ob-HNSP01 and ob/ob-HNSP02 supplemented groups exhibited lower levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, fasting blood glucose, and insulin, as well as a reduced atherogenic index in comparison with the control group. Molecular analysis also demonstrated that the intake of HNSP01 and HNSP02 resulted in a diminished activation of factors associated with fatty acid synthesis, including acetyl-CoA carboxylase and fatty acid synthase, while concurrently enhancing factors associated with lipolysis, including adipose triglyceride lipase and hormone-sensitive lipase, in the adipose tissue. Conclusion: Taken together, these findings collectively demonstrate the potential of sweet pumpkin powder as a functional food ingredient with therapeutic properties against obesity and its associated metabolic disorders, such as insulin resistance and dyslipidemia.

• Korean Journal of Ecology and Environment
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• v.56 no.3
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• pp.218-228
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• 2023

Invasive predators are one of the most damaging species groups to biodiversity. In the Nakdong River, the lake skygazer Chanodichthys erythropterus is a dominant species that is fiercely carnivorous and a concern for commercial fish. Although it is important to understand the ecological characteristics related to the feeding habit, studies on the diets of lake skygazer in Nakdong River have been limited to studies of gut contents. In this study, the trophic position (TP) and feeding habits of C. erythropterus were studied by calculating TPs using samples collected from 13 sites throughout the Nakdong River. Compound-specific isotopic analysis of amino acids provided reliable TPs from the muscle of Lake skygazer C. erythropterus without any isotope baseline. The results were approximately 3 to 3.6 and suggesting a carnivorous but size-dependent prey variation. In particular, the TP variability of C. erythropterus observed in the Nakdong River showed that it had a selective feeding habit compared to carnivorous fish species of relatively similar trophic levels.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.407-417
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• 2024

The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

• Journal of the Korean Society of Food Culture
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• v.14 no.4
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• pp.289-304
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• 1999

The purpose of this study was to examine the consumers' acceptance of irradiated foods according to sociodemographic characteristics and the factors to distinguish subjects with differential levels of their willingness to buy them. Data were collected from the 365 women living in Youngnam area by the self-administered questionnaire. The results from this study were as follows. First, consumers were concerned regarding food safety issues in general and particularly preservatives. Second, many subjects had not heard of the irradiated foods and showed wait-and-see attitude in the willingness to accept them. Consumers' willingness to purchase them were higher than any other cases if radiation would not remain in foods. Third, the results from the discriminant analyses showed that the concern toward food safety, perceived innovativeness, willingness to pay more for organic foods, and knowledge of irradiation were the factors to distinguish groups with differential levels of willingness to purchase the irradiated foods. The results from the study imply that accurate and scientific information about food irradiation should be given to the consumers.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.6-14
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• 2008

Objective of this study was to investigate the residual levels of mercury (Hg) in soil for "Top-rice" area and its uptake into rice plant for making sure food safety as compared to "Top-rice" & common rice produced from 2005 to 2006. Hg was analyzed with the direct mercury analyzer (DMA 80, Milestone, Italy), which implements the US/EPA method 7473. The average concentration of Hg in paddy soil was 0.031 mg/kg, which was below at 1/25-1/65 fold of the threshold levels (concern level 4 mg/kg, action level 10 mg/kg) for soil contamination designated by "The Soil Environment Conservation Law" in Korea. The maximum residue level (MRLs) for Hg residue in the polished rice is not designated in Korea. Therefore, Hg contents in the polished rice of "Top-rice" brand and common rice were compared to other country's criteria. Hg contents in the polished rice of "Top-rice" brand was 0.0018 mg/kg, which was lower at 1/10-1/30 fold than the MRLs, 0.02 mg/kg of China criteria and 0.05 mg/kg of Taiwan criteria, respectively. Hg were 0.02788, 0.00896, 0.00182, 0.00189, 0.00166, 0.00452 and 0.00145 mg/kg in soil, rice straw, unhulled rice, rice hulls, brown rice, rice bran, and polished rice produced in 2006 "Top-rice" area, respectively. For the ratio of Hg as compared to Hg contents in soil, there were 0.321 of rice straw ${\gg}$ 0.162 of rice bran ${\gg}$ 0.068 of rice hulls > 0.065 of unhulled rice > 0.060 of brown rice> 0.052 of polished rice. And, the slope of Hg uptakes was steeped as following order; rice straw ${\gg}$ rice bran ${\gg}$ rice hulls > unhulled rice > brown rice > polished rice. It means that the more slope steeped was the more uptakes. For the distribution of Hg uptaken, there was 83.8% into rice straw, and 16.2% into unhulled rice, 2.8% into rice hulls, 12.4% into brown rice, 3.5% into rice bran and 9.7% into polished rice. Consequently, it was appeared that the Hg contamination in the polished rice should not be worried in Korea.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.400-407
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• 2014

Urban farming supplies emotional stability and fresh vegetables to participating persons, however, no information regarding the biosafety of agricultural products from urban farming is available. Here, we collected 260 samples of Chinese cabbages and lettuce from 4 urban community gardens and 6 roof gardens in Seoul from September through October 2012, and monitored the microbiological and parasitological contamination quantitatively and/or qualitatively. The mean counts of total aerobic bacteria and coliforms were $6.1{\pm}0.8\;log\;CFU{\cdot}g^{-1}$ ( range, $5.4{\pm}0.6{\sim}7.1{\pm}0.8\;log\;CFU{\cdot}g^{-1}$) and $4.0{\pm}0.7\;log\;CFU{\cdot}g^{-1}$ (range, $2.3{\pm}0.6{\sim}6.1{\pm}0.9\;log\;CFU{\cdot}g^{-1}$), respectively. Coliforms were detected on 59.6% among 260 vegetable samples. There were no significant differences in the contamination levels of total aerobic bacteria and coliforms between the Chinese cabbages and lettuce, whereas both levels of vegetables from urban community gardens were higher than those of roof gardens (p > 0.05). Escherichia coli was isolated at 3.1% among whole vegetables, and contamination level was $1.5{\pm}0.2\;log\;CFU{\cdot}g^{-1}$. Among foodborne pathogens, Staphylococcus aureus was detected in 1.5%, however, Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were not detected on any of the vegetable samples. We also found undefined parasite eggs from two samples of Chinese cabbages (0.8% of total vegetables we tested). From these study, we found the presence of microbial contamination of agricultural products from urban farming, thus we need further concern to improve the biosafety during production of agricultural products.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.8-13
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• 2010

Bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) were obtained by a polymerization reaction of epichlorohydrin (ECH) with bisphenol A (BPA) or bisphenol F (BPF). These compounds are commonly used as monomers or additives such as a polymerization stabilizer and a hydrochloric acid scavenger of epoxy resin, polyvinyl chloride (PVC)-containing organosols and polyester lacquers, that are applied to the internal surface of most canned foods to impart chemical resistance. The unreacted BADGE, BFDGE and their reaction products migrating from epoxy resin, PVC-containing organosol and/or polyester lacquer-based food packaging materials into the foods have recently become an issue of great concern because of increased customer demand for safety. This study was conducted to develop a rapid and sensitive simultaneous analysis method based on HPLC/FLD and HPLC/APCI-mass and to evaluate the concentration of BADGE, BFDGE and their metabolites, BADGE $H_2O$, BADGE $2H_2O$, BADGE HCl, BADGE 2HCl, BADGE HCl $H_2O$, BFDGE $H_2O$, BFDGE $2H_2O$, BFDGE HCl, BFDGE 2HCl and BFDGE HCl $H_2O$ for 133 canned food samples. The method provided a linearity of 0.9997-0.9999, a limit of detection of $0.01-0.13\;{\mu}g/mL$, a limit of quantitation of $0.03-0.44\;{\mu}g/mL$ and a recovery (%) of 85.64-118.18. The number of samples containing BADGE, BFDGE or their metabolites were: 28/133 (21.1%), with levels of 0.400-0.888 mg/kg being observed for aqueous foods (19/133) and 0.093-0.506 mg/kg being observed for oily foods (9/133).