• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.3
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• pp.149-158
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• 2021

Advances in food packaging play an important role in keeping food manufacturing and food supply safe. Food packaging facilitates the storage, handling, transportation and preservation of food, and also contributes to the minimization of food waste. On the other hand, food packaging materials have high production volumes, short usage times, and accelerate the occurrence of environmental problems related to waste. The circular economy has already been introduced to pursue sustainability through resource conservation and recycling, and to reduce waste and carbon emissions. By activating an eco-friendly economic system that minimizes resource depletion and environmental pollution, reducing, reusing, recycling and redesigning the goals of the circular economy will reduce the impact of food packaging on the environment. This review focused on the safety aspects of recycled food packaging as recycling is currently considered an important means of packaging waste management. Assessing the safety of recycled packaging is very important because recycling can increase the levels of potentially hazardous chemicals in packaging and in the food after they are migrated. Various food packaging materials such as plastic, paper and cardboard, aluminum, steel, and multi-material multi-layers packaging are commonly used, but only the recycling safety of plastic food packaging materials, which is the most used and has a significant increase in post-use problem, is discussed in this review.

• Economic and Environmental Geology
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• v.55 no.3
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• pp.281-293
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• 2022

We examined degradation characteristics of lead based pigments(white lead, Red lead, Litharge) according to atmospheric environmet condition, for example atmospheric gas(CO₂, NO₂) and soluble salt. Painted samples not changed material compositions but were occured the color change(𝚫E 4~31) after exposed UV irradiation. All sample were not affected by CO₂ gas not only color but chemical composition. However, samples were remakably changed color exposed NO₂ gas and it was formed secondary product like as lead nitrate. Such as red lead and white lead samples' color difference were 𝚫E 2 and 𝚫 10 respectively and became dark, along with litharge became bright and color difference was 𝚫E 5 after react with NO₂ gas. It confirm that NO₂ was influential factor than CO₂ in the case of same concentration. Furthermore salt spray test was taken to figure out soluble salt influence in fine dust. The result showed noticeable color change and secondary product was formed on samples' surface. The glue film peeled off or hole, and color changed around the secondary products. After salt spray, XRD pattern showed decrease peak intensity and lower crystalinity. As a result of salt spray test, white lead was formed new product litharge and litharge was formed litharge and minium. According to the results, influential atmospheric factors for conservation of paint pigments were UV, NO₂, soluble salt, and litharge was most weakness throughout lead base pigments.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.30-30
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• 2001

The culture of preantral follicles has important biotechnological implications through its potential to produce the large quantity of oocytes for embryo production, transgenesis research, conservation of rare breed, and a potential source of ovarian genetic material. The present study was conducted to establish the optimal conditions of in vitro culture for intact bovine preantral follicles; and to examine the developmental ability of oocytes derived from the in vitro-grown preantral follicles; and to investigate the effects of various concentrations of FSH and LH on these processes. Bovine preantral follicles (150 $\pm$ 1.2${\mu}{\textrm}{m}$), surrounded by theca cell, were isolated enzymetically and mechanically from ovarian cortical slides in Leibovitz L-15 medium containing 1 mg/$m\ell$ collagens and 0.2 mg/$m\ell$ DNase I and cultured for 25 days in the presence of different concentrations of bovine FSH and LH in $\alpha$MEM medium with insulin, transferrin, and selenite. The survival was tested by frypan Blue and Hematoxylin. The survival and growth rates of follicles were higher in FSH treatment groups than these in control (P<0.001), but there were no significant differences between the LH treatment groups and the control. In 25 days, the survival and growth rates of follicles in FSH and LH treatment group (50%, 300$\pm$1.0${\mu}{\textrm}{m}$) were higher than in FSH treatment group (40%, 244$\pm$0.5${\mu}{\textrm}{m}$) and the control group (25%, 160$\pm$ 1.0${\mu}{\textrm}{m}$). Fifty-five percent of healthy antral follicles were obtained, and 60% of the oocytes complete meiotic maturation to the metaphase II stage. Twenty-two percent of the mature oocytes underwent cleavage, and 9% developed to the blastocyst stage. In this study, in vitro-grown oocytes (111 $\pm$ $1.5mutextrm{m}$), under our culture conditions, were not equivalent in size to the in vivo-grown oocytes (130$\pm$1.3${\mu}{\textrm}{m}$). Therefore, these results suggest that bovine preantral follicles with intact theca cell can grow to the antral stage in 25days, and that oocytes from those follicles can acquire the meiotic competence and normally undergo fertilization and development to the blastocyst stage. However, the developmental capacity of in vitro-grown oocytes is presumably not comparable to those of the in vivo counterparts.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1610-1610
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• 2001

Microbiological examination of silage is of little value in gauging the outcome of silage, and so chemical analysis is more reliable and meaningful indicator of quality. On the other hand chemical assessments of the principal fermentation products provide an unequivocal basis on which to judge quality. Livestock require energy, protein, minerals and vitamins from their food. While fresh forages provide these essential items, conserved forages on the other hand may be deficient in one or more of them. The aim of the conservation process is to preserve as many of the original nutrients as possible, particularly energy and protein components (Woolford, 1984). Silage fermentation is important to preservation of forage with respect of feeding value and animal performance. Chemical and bacteriological changes in the silo during the fermentation process can affect adversely nutrient yield and quality (Moe and Carr, 1984). Many of the important chemical components of silage must be assayed in fresh or by extraction of the fresh material, since drying either by heat or lyophilisation, volatilises components such as acids or nitrogenous components, or effects conversion to other compounds (Abrams et al., 1987). Maize silage dorms the basis of winter rations for the vast majority of dairy and beef cattle production in Uruguay. Since nutrient intake, particularly energy, from forages is influenced by both voluntary dry matter intake and digestibility; there is a need for a rapid technique for predicting these parameters in farm advisory systems. Near Infrared Reflectance Spectroscopy (NIRS) is increasingly used as a rapid, accurate method of evaluating chemical constituents in cereals and dried forages. For many years NIRS was applied to assess chemical composition in dry materials (Norris et al., 1976, Flinn et al., 1992; Murray, 1993, De Boever et al., 1996, De la Roza et al., 1998). The objectives of this study were (1) to determine the potential of NIRS to assess the chemical composition of dried maize samples and (2) to attempt calibrations on undried samples either for farm advisory systems or for animal nutrition research purposes in Uruguay. NIRS were used to assess the chemical composition of whole - plant maize silage samples (Zea mays, L). A representative population of samples (n = 350) covering a wide distribution in chemical characteristics were used. Samples were scanned at 2 nm intervals over the wavelength range 400-2500 nm in a NIRS 6500 (NIRSystems, Silver Spring, MD, USA) in reflectance mode. Cross validation was used to avoid overfitting of the equations. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation (SECV). The calibration statistics were R$^2$ 0. 86 (SECV: 11.4), 0.90 (SECV: 5.7), 0.90 (SECV: 16.9) for dry matter (DM), crude protein (CP), acid detergent fiber (ADF) in g kg$\^$-1/ on dry matter, respectively for maize silage samples. This work demonstrates the potential of NIRS to analyse whole - maize silage in a wide range of chemical characteristics for both advisory farm and nutritive evaluation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.517-527
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• 2023

Objectives: We examine cases of chemical poisoning that occurred in the cleaning of metal parts and the regulations on halogenated solvents in other countries and propose regulations necessary to prevent chemical poisoning from halogenated solvents. Methods: We collected cases of chemical poisoning through the website of the Korea Occupational Safety and Health Agency. A review of the literature was conducted focusing on regulations related to halogenated solvents in the United States and the European Union, particularly for cleaning metal parts. Among the Material Safety Data Sheets submitted to the government, MSDS containing eleven substances were extracted to confirm the composition and product use. We investigated cleaning methods for metal parts used in South Korea. For the hazard classification, the European Chemicals Agency or Japan's NITE's website was used. Results: In the case of poisoning, the cleaning methods involving trichloromethane were dipping and dry, which was not found in the literature. It was confirmed that many halogenated solvents and dimethyl carbonate were used for metal cleaning in South Korea. In vapor degreasing using TCE in the USA, even if the facility is strictly managed, such as by installing cooling coils in open cleaning facilities, the risk of exposure to TCE is considered to be not only carcinogenic but also a concern for acute and chronic effects. In comparison, exposure through Korean work methods such as dipping and drying operations is inevitably much higher. Conclusions: The transition to water-based cleaning with low-hazard chemicals should be a priority in the cleaning process. In the case of metal parts that require precise cleaning, if the use of a halogenated solvent is inevitable, a closed degreasing facility should be used to minimize exposure. The current regulations in the Occupational Safety and Health Act, the Chemical Substances Control Act, and the Air Environment Conservation Act do not require cleaning facilities to minimize emissions. To protect the health of workers using halogenated solvents to clean metal parts, regulations that require a fundamental reduction in exposure will be necessary.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.129-139
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• 2008

Marine ecotoxicological standard method was applicated using marine rotifer and benthic copepod as primary consumer of marine ecosystem. Marine rotifer, Brachionus plicatilis and benthic copepod, Tigriopus japonicus were designated as standard test species with the endpoints of 24hr neonate mortality (24hr $LC_{50}$) and 48hr population growth (48hr $EC_{50}$) for rotifer, and 48hr nauplius mortality (48hr $LC_{50}$) for benthic copepod. Tests method was referred to those of ASTM (American Society for Testing and Materials) with the replacement of test species which are widely distributed in Korean waters. The two species showed a wide tolerance on salinity ($5{\sim}35\;psu$) and can be easily cultured in small space even they were not as sensitive as in the mortality test using the nauplius of marine invertebrates. However, these species revealed the significant "concentrationresponse relationship" tested with ocean disposal wastes, and reproducibility using cadmium as standard reference material between laboratories. Accordingly, these two species have good potential as test species for marine ecotoxicological test species. Also, we strongly recommend that at least one of these species be included in the test species of "battery test" in marine bioassay.

• The Journal of Engineering Geology
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• v.34 no.2
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• pp.163-171
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• 2024

Changes in the soil layer on Dokdo are important both academically and with regard to sustainable conservation and utilization of the islands. Continuous investigation and observation are necessary, as the soil layer is essential to the growth of plants and, therefore, the islands' ecosystem. Such work was carried out for about 8 years using soil erosion measuring bars, which are durable and facilitate simple monitoring of changes in the soil layer. Each bar comprised a rod measuring 30~50 cm long and 1.5 cm in diameter, and the use of stainless steel afforded resistance to corrosion caused by sea breezes. Six measuring bars were installed in the soil layers of each of two islands, Dongdo and Seodo, and measurements were taken one to three times a year from 2014 to 2021. The field measurements indicate that soil was deposited on Dongdo but eroded on Seodo during the observation period. As the measuring bars on Dongdo were located in the central and lower parts of the island, the observed changes in the soil layer resulted mainly from sedimentation of material eroded by weathering or soil runoff from the upper part of the island. In contrast, the measurement locations on Seodo were located in the upper and central parts of the island, where soil erosion and runoff diminished the soil layer at the observation points.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.26-27
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• 2018

With entry into force of the Nagoya Protocol to promote the fair sharing of the benefits of accessing and utilizing genetic resources, much support has been given to research on the development of biomaterials and products using domestic natural resources. Conservation and resource-saving of native species became very important through Nagoya Protocol enactment. The trend of cosmetic industry has been shifing from use synthetic chemicals to natural biomaterials, due to the safety regulations on new materials, ban on animal experiments, and expansion of cosmeceuticals range. In addition, functional cosmetic range has been expanded from whitening, wrinkle improvement, and ultraviolet shielding, to hair loss, hair loss alleviation, acne relaxation, and moisturizing of atopic skin, thus causing the activation of research about field of efficacy evaluation on natural biomaterials and commercialization. Chungbuk province is fostering the bio industry as a key industry for regional economic growth. For this purpose, Osong Biotechnology Complex/Ochang Science Industrial Complex in middle area, Jecheon biovalley in northern region, and Chungju Enterprise city have been established, thus playing a pivotal role in Bio innovative cluster in Korea. In particular, it was established the osong cosmetics clinical research support center to develop the cosmetics industry in chungbuk, thereby supporting clinical trials, efficacy evaluations, overseas certification, and overseas market entry in order to advance into the global market. In addition, oriental plants such as astragalus propinquus, schisandra chinensis, eucommia, alpiniae oxyphyllae fructus and biancaea sappan are being actively studied as global cosmetic ingredients through the promotion of various national research and development projects using natural materials in chungbuk province. The chungbuk natural product industry is expected to grow further throughout cosmetics industry development in the future, as companies and research institutes are actively promoting the secure index of effective material in natural products and effective material commercialization.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.199-205
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• 2008

This study was carried out to find out causes of high Ni content and characteristics of potential increase of Cu and Zn contents in the soils of Jeju area. Soil samples were collected from 4 series of Alfisols, 35 series of Andisols, 9 series of Entisols, 16 series of Inceptisols, and 1 series of Ultisols, respectively. Parent material (gravel) samples were also collected from the same sites where soil samples were taken. Both soil and parent material samples were analyzed for Ni, Cu, and Zn. The average Ni content of all the soil samples was $79.2mg\;kg^{-1}$, which was exceeded warning standard for Ni against the Soil Conservation Act in Korea, whereas that of Cu and Zn contents were lower than the warning standard for Cu and Zn. The difference of Ni, Cu and Zn content was not consistent depending upon soil color. Ni content in the soil samples from Entisols was particularly high, whereas that from the other soil orders was similar to each other. Cu and Zn contents in the soil samples were similar regardless of the difference in soil order. Ni content in Seongsan Formation(SSF), Cinder cone(C) and acicular Feldspar Olivine Basalt(FOB) was high, while that in Feldspar Basalt(FB) and Trachy Andesite lava(TA) was low. Ni content in the non-agricultural land was higher compared with that in the agricultural land, whereas Cu and Zn contents in the non-agricultural land were significantly lower than that of agricultural land. The topsoil/subsoil ratios for Ni content in most of the soil samples were less than 1, while that for total contents of Cu and Zn in many of the soil samples were larger than 1 indicating potential Cu and Zn accumulation in topsoil by artificial reasons.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.4-21
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• 2019

In this paper, 23 Silla gold earrings from the sixth and seventhand centuries, excavated from the Yeongnam region, were analyzed. Based on the silver content of the gold plate, they were classified into three types. The classifications included type I(20-50wt%), type II(10-20wt%) and type III (less than 10wt%). In the analysis process, the composition and morphological differences were identified on the surface of the gold plate. In the case of type I and II earrings, it was observed that the fine holes were concentrated in a relatively higher part of the gold content. The causes of the difference in the surface composition of the gold plate were divided into four categories: 1) surface treatment, 2) thermal diffusivity in the manufacturing process, 3) differences in composition of alluvial gold, and 4) the refining method of gold. It is possible that depletion gilding was attempted to increase the gold content while intentionally removing the other metals from the surface of the gold alloy in the portion where the gold deposit is relatively concentrated on the surface of the gold plating. The highest copper content was detected in the earring with the highest gold content of the analyzed earrings, and it was assumed that thermal diffusion had occurred between the gold plate and the metal rod during the manufacturing process rather than intentional addition. Copper was detected only in the thin ring earring type, and copper was not detected in the thick ring earring type or pendant type. It also proves that this earring has a high degree of tightness at higher temperatures, as there was an invisible edge finish on other earrings and horizontal wrinkles on the gold plate surface. In terms of the material of the gold plate, we examined whether the silver content of the gold plate was natural gold or added by alloy through analyzing the alluvial gold collected in the region. As a result of the analysis, it was found that on average about 13wt% of silver is included. This suggests that type II is natural gold, type III is refined gold, and type I seems to have been alloyed with natural gold. Here, we investigated the refining method introduced in the ancient literature, both at home and abroad, about the possibility of alloying silver after the refining process of type III earrings and then making pure gold. It was found that from ancient refining methods, silver which had been present in the natural gold was removed by reacting and combining with silver chloride or silver sulfide, and long-term efforts and techniques were required to obtain pure gold through this method. Therefore, it was concluded that the possibility of adding a small amount of silver in order to increase strength after making pure gold through a refining process is low.