• Journal of Marine Life Science
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• v.5 no.2
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• pp.35-42
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• 2020

17β-estradiol (E₂) is a natural hormone secreted by ovary, and continuously discharged from household and livestock wastewater into aquatic environment. Due to its strong estrogenic activity, it has adverse effects on development and reproduction in crustacean as an endocrine disrupting chemical. Although ecdysteroid signaling pathway play a key role in development in crustacean, little information on transcriptional modulation of ecdysteroid-related genes in response to E₂ is available in small crustacean. Here, we investigated the acute toxicity of E₂ to obtain 24-h LC_x values in the brackish water flea Diaphanosoma celebensis. Time-dependent expression patterns of seven ecdysteroid pathway - related genes (CYP314a1, EcRA, EcRB, USP, ERR, Vtg, VtgR) were further examined using quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR). As results, 24-h LC₅₀ and LC₁₀ values were 9.581 mg/l and 4.842 mg/l, respectively. The mRNA expression of CYP314a1, EcRA, USP, VtgR was significantly up-regulated at 12 or 24 h after exposure to E₂. These findings indicate that E₂ can affect their molting and reproduction by modulating the expression of ecdysteroid pathway - related in D. celebensis. This study will be useful for better understanding of molecular mode of action of endocrine disrupting chemicals on molting process in small crustacean.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.185-198
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• 2019

Human tissue undergoes aging by the oxidant damage via structural change and its physical properties. The skin aging process is well known and many evaluations have been conducted. However, studies on hair aging were relatively few and thus care for aging hair is difficult. This study aims to fabricate an aging hair and identify anti-aging effect with known ingredient in anti-aging. First of all, physical properties of aging hair of age 60s by physiologically intrinsic factors were compared to those of the hair made by various extrinsic factors such as several chemical reactions and iteration numbers of the treatments. The extrinsic aging hair of this study relates to the less amount of lipid and to the hair of perm treated once accordingly, wherein several physical properties, preferably comprise roughness and tensile strength, present a novel concept of the intrinsic aging hair. The penetration of peptide into the aging hair was leading the extrinsic hair towards more structurally directed a younger hair. In addition to the structural change, the penetration of the peptide enhanced texture and tensile strength of the aging hair. These patterns have been also found in addition of propolis. For the first time, these qualitative studies exhibit that indeed our extrinsic aging hair well describes the anti-aging efficacy as a receptor for a cross-linker and the ingredients of human hair.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1456-1471
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• 2018

This article discusses the nutritional requirements, reviews senior or geriatric dog nutritional evaluation, and then addresses some common nutrition-related problems in older dogs. The purpose of this study was to investigate the Physiologic change associated with aging, essential nutrients and their diseases in senior or geriatric dog subjects. According to a 2002 market research, 30% to 40% of dogs raisedin the United States are 7 years of age. In Europe the number of dogs considered to be "senior or geriatric" (>7 years of age) increased by approximately 50% between 1983 and 1995. A 2012 e-mail survey of 50,347 respondents revealed that 33.2% of dogs were 6 to 10 years of age and 14.7% were older than 11 years in the United States. The average life expectancy of dogs raised in the home is affected by health care, aging and nutrition.And, the aging process is influenced by breed size, genetics, nutrition, environment, and other factors. Although many pets remain active and youthful well into their teens, most dogs start to slow down and may show signs of aging beginning as early as 5 or 6 years of age. Improvements in the control of various diseases and in the nutrition of dogs have resulted in a gradual increase in the average lifespan of companion dogs. Nutritional goals for aging dogs include supporting health and vitality, preventing the onset or slowing the progression of age-related health disorders, and enhancing the dog's quality of life and, if possible, life expectancy. Aging brings with its physiologicchanges. Some changes are obvious, such as whitening of hair, a general decline in body and coat condition, and failing senses including sight and hearing. Other changes are less obvious, however, and these include alterations in the physiology of the digestive tract, immune system, kidneys, and other organs. Nutritional requirements can change with age. In addition, many diseases common in older dogs may be nutrient-sensitive, meaning that diet can play an important role in the management of the condition.

• Clean Technology
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• v.25 no.3
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• pp.245-255
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• 2019

Pressurized oxy-fuel combustion is a promising technology for $CO_2$ capture with a benefit of improving power plant efficiency compared with atmospheric oxy-fuel combustion. Prior to $CO_2$ compression in this process, a flue gas condenser (FGC) is used to remove $H_2O$ while recovering the latent heat. At the same time, the FGC has a potential for high-efficiency removal of $SO_x$ and $NO_x$ by exploiting their good solubility in water. In this study, experiments were carried out in a lab-scale, direct contact FGC under different pressures varying between 1 and 20 bar to evaluate the removal efficiency of $SO_2$ and $NO_x$ for individual gases and their mixture. In the tests for individual gases, 20% and 76% of $NO_x$ was removed at 1 bar and 10 bar, respectively. Even higher removal efficiencies were achieved for $SO_2$, and also these were maintained for longer as the pressure increased. In the tests for $SO_2$ and $NO_x$ mixture, the removal efficiency of $NO_x$ increased from 13% at 1 bar to 56% at 20 bar because of higher solubility at elevated pressures. $SO_2$ in the mixture was initially dissolved almost completely and then increased by 1,219 ppm at 1 bar and by 165 ppm at 20 bar. Overall, the removal efficiency of $SO_2$ and $NO_x$ was increased at elevated pressures, but it was lower in the mixture compared with individual gases at identical conditions because of a lower pH and associated chemical reactions in water.

• Food Science and Industry
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• v.52 no.2
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• pp.188-201
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• 2019

In the past, food additives were classified and managed as chemical synthetic and natural additives according to the manufacturing process, but it was difficult to confirm the purpose or function of food additives.CODEX, an internationalstandard, classifies food additives according to their practical use, based on scientific evidence on the technical effects of food additives, instead of classifying them as synthetic or natural. Therefore, very recently, the food additive standards in Korea have been completely revised in accordance with these global trends. Currently, the classification system of food additives is divided into 31 uses to specify their functions and purposes instead of manufacturing methods. Newer revision of the legislative framework for defining and expanding the scope of the Act as an enlarged area is required. Competition for preempting new food products based on bio-based technology is very fierce in order to enhance the safety of domestic people and maximize the economic profit of their own countries. In this age of infinite competition, it is very urgent to revise or supplement the current regulations in order to revitalize the domestic food industry and enhance national competitiveness through the development of food additives using new biotechnology. In this report, current laws on domestic food ingredients, food additives and manufacturing methods, and a comparison of domestic and foreign advanced countries' regulations and countermeasures strategies were reviewed to improve national competitiveness of domestic advanced biotechnology-based food additives industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.139-147
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• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.

• Clean Technology
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• v.27 no.1
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• pp.1-8
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• 2021

Due to the negative impacts of microplastics (MPs) on the ecosystem, the investigation of its occurrence and its treatment from sewage and wastewater treatment plants (WWTPs) have received a lot of attention in the recent years. Most MPs are precipitated and removed with the sludge during the treatment process. Proper sludge management is immensely necessary to avoid MP exposure in the environment. However, the domestic research on this aspect is limited. This study reviews appropriate sludge management approaches to decrease environmental MP exposure. This can be achieved through investigating sludge generation and treatment, regulation laws and government policy trends with an emphasis on WWTPs. The ratio of sludge in sewage treatment plants has been observed to be highest in recycling followed by incineration and landfills. Recycling is the highest in fuel followed by construction materials and composting. For WWTPs, the highest ratio is in recycling followed by fuel and landfills, and recycling is confirmed in the following order: incineration > after composting > after solidification > earthworm breeding. Treatment approaches that can increase the exposure of MPs to the ecosystem are considered to be used in landfills and agricultural fields. However, this method is not appropriate given the insufficient capacity of domestic landfills and the sufficient supply of existing chemical and animal manure fertilizers. Instead, it would be rational in terms of environmental preservation to expand the use of fuel and energy in connection with the new and renewable energy policy, and to actively seek the use of sub-materials for construction materials. In order to secure the basic data for the effectiveness of future planning and revision of related laws, it is required to perform an in-depth investigation of the sludge supply and demand status along with the environmental and economic effects.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.264-274
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• 1993

This study was carried out to assess the agronomic characters and physicochemical properties of floury and chalky-endosperm mutant lines induced by chemical mutagen treatment to rice varieties, Hwacheongbyeo and IR24. Linkage analysis of a floury-endosperm gene was carried out using linkage testers. The grain size of brown rice of the mutants was smaller than that of the original varieties. The l, 000-grain and 1$\ell$ weight were lighter in the mutants compared with those in the original varieties. The compound starch granules in the endosperm cell of the mutants showed a loosely-packed crystalline structure. Amylose contents in mutants ranged from 16.9 to 28.5%. Crude protein contents of the mutants were not significantly different from the original rice variety, Hwacheongbyeo, but white core mutant(line 47106) derived from IR24 showed higher protein(l1.32%) compared with IR24(8.30%). The mutants showed slightly harder gel characteristics, and much lower viscosity in Amylograph than original varieties. Steamed rice-cakes from mutant lines showed greater volume than those from original varieties. During the process of alcohol fermentation, Brix in the mutants(especially floury mutants) decreased faster and the alcohol production after 10-day fermentation was much greater in the mutants than in the original varieties. Three different gene loci for floury endosperm characteristics were identified from the allelism test among mutant lines, and the genes were tentatively symbolized as flo-a, flo-b and flo-c, respectively. A floury gene, flo-a, was linked with lg(liguleless) gene in the linkage group N, with R.V. 5.76$\pm$1.72%.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.781-797
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• 2023

Recently, there has been a rapid response from mineral-demanding countries for securing critical minerals in a high tech industries. Graphite, while overwhelmingly dominated by China in production, is changing in global supply due to the exponential growth in EV battery sector, with active exploration in East Africa. Rare earth elements are essential raw materials widely used in advanced industries. Globally, there are ongoing developments in the production of REEs from three main deposit types: carbonatite, laterite, and ion-adsorption clay types. While China's production has decreased somewhat, it still maintains overwhelming dominance in this sector. Recent changes over the past few years include the rapid emergence of Myanmar and increased production in Vietnam. Nickel has been used in various chemical and metal industries for a long time, but recently, its significance in the market has been increasing, particularly in the battery sector. Worldwide, nickel deposits can be broadly classified into two types: laterite-type, which are derived from ultramafic rocks, and ultramafic hosted sulfide-type. It is predicted that the development of sulfide-type, primarily in Australia, will continue to grow, while the development of laterite-type is expected to be promoted in Indonesia. This is largely driven by the growing demand for nickel in response to the demand for lithium-ion batteries. The global lithium ores are produced in three main types: brine lake (78%), rock/mineral (19%), and clay types (3%). Rock/mineral type has a slightly higher grade compared to brine lake type, but they are less abundant. Chile, Argentina, and the United States primarily produce lithium from brine lake deposits, while Australia and China extract lithium from both brine lake and rock/mineral sources. Canada, on the other hand, exclusively produces lithium from rock/mineral type. Vanadium has traditionally been used in steel alloys, accounting for approximately 90% of its usage. However, there is a growing trend in the use for vanadium redox flow batteries, particularly for large-scale energy storage applications. The global sources of vanadium can be broadly categorized into two main types: vanadium contained in iron ore (81%) produced from mines and vanadium recovered from by-products (secondary sources, 18%). The primary source, accounting for 81%, is vanadium-iron ores, with 70% derived from vanadium slag in the steel making process and 30% from ore mined in primary sources. Intermediate vanadium oxides are manufactured from these sources. Vanadium deposits are classified into four types: vanadiferous titanomagnetite (VTM), sandstone-hosted, shale-hosted, and vanadate types. Currently, only the VTM-type ore is being produced.