검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 63

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Given the recent increases in feed cost, the demand for rice straw has been increasing on dairy farms because it is cheaper than expensive imported forages. Therefore, it is necessary to study the effect of rice straw feeding on the growth and productivity of dairy heifers. This study compared how feeding tall fescue and rice straw affects the growth, age at first calving, and feed cost of heifers. we compared the growth, age at first calving, and feed cost for each group during the breeding period. Body height was higher in the tall fescue-fed group than in the rice straw-fed group (p<0.05). The length of the growing stage was significantly shorter in the tall fescue group than in the rice straw group (p<0.001) and the age at calving also showed a significant reduction in the tall fescue group compared to the rice straw group (p<0.001). However, the feed cost was lower in the rice straw group because of the difference in the unit price of forage (p<0.001). Based on these results, during the growing period, the rice straw group had delays in growth and the age at first calving compared to the tall fescue group, but also had reduced feed costs in the short term.
        4,000원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to prepare rice straw silage using cabbage by-product and persimmon peel which are agricultural by-products produced during the same season in Korea. The treatments comprised a commercial corn silage as the control and four rice straw silages (P15-1, P15-2, P30-1, and P30-2) with different levels of persimmon peel supplementation (15%, 30%) and ensiled periods (1 or 2 months). The cabbage by-products were used to adjust silage moisture (approximately 65%). The quality of the experimental silages was evaluated based on organic acid content, palatability to three Holstein dairy cows, and manufacturing cost. In the corn silage, all chemical compositions, except total digestible nutrients and levels of lactic and butyric acids, were significantly (p<0.05) higher than those of the rice straw silages. However, considering the quality analysis using Flieg's score, the rice straw silage supplemented with 30% persimmon peel ensiled for 2 months (P30-2) was estimated as second grade to corn silage, and was relatively better in palatability to dairy cows than the other rice straw silages, which were considered third grade. The manufacturing cost of rice straw silages using cabbage by-product and persimmon peel compared to that of corn silage was reduced by 28%. Consequently, to prepare rice straw silage adjusted to 65% moisture using only cabbage by-products without inoculant, 30% of persimmon peel, 10% of ground corn, and 2% of molasses as a sugar source should be ensiled for at least 2 months.
        4,000원
        3.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 사일리지 발효제 첨가가 볏짚 사일리지에서 곰팡이 독소 및 in situ 섬유소 소화율에 미치는 영향을 평가하고자 실시 하였다. 사일리지 발효제로 L. plantarum 단일제 및 L. plantarum 과 S. cerevisiae의 혼합제를 첨가하였을 때 사일리지의 발효 및 섬유소 분해에 영향을 주었을 뿐만 아니라 곰팡이독소 감소에도 영향을 주었다. 시험 시료에서 곰팡이독소 중 ochratoxin A 및 zearalenone만 발견되었다. Ochratoxin A 및 zearalenone는 대조구에서 각각 38.11±2.22 및 633.67±50.30 ug/kg 수준으로 발효제 첨가로 감소 경향이 나타났고, 혼합제에서만 각각 27.78±2.28 및 392.72± 25.04 ug/kg 수준으로 유의적 차이를 보였다(p<0.05). pH는 대조 구에 비하여 단일제 및 혼합제에서 낮았고(p<0.05), lactic acid는 대조구(8.18±0.93 mM)에 비하여 단일제(11.73±0.31 mM)가 높았고, 혼합제(16.01±0.88 mM)에서 가장 높은 수준을 나타내었다 (p<0.05). Acetic acid와 propionic acid는 발효제 첨가에 따라 유 의적으로 낮아짐을 발견하였다(p<0.05). 그리고 total VFA도 발 효제 첨가가 대조구에 비하여 낮았다(p<0.05). NDF 및 ADF의 반추위 in situ 분해율은 배양기간 동안 혼합제가 가장 높은 수준 의 분해율을 유지하였고, 다음으로 단일제가 높았으며, 대조구가 가장 낮은 수준을 유지하였다. 그리고 이들 NDF 및 ADF 분해율 은 각각 배양 12 및 24시간 이후 모든 시간대에서 실험구간 유의 차를 나타내었다(p<0.05). 이상의 연구 결과는 볏짚 사일리지 제조에서 사일리지 발효제 사용은 발효 및 섬유소 분해에 영향을 주었을 뿐만 아니라 곰팡 이독소 감소에도 영향을 주었다. 그리고 곰팡이독소 감소는 L. plantarum 단일제보다 L. plantarum과 S. cerevisiae 혼합제의 효능이 더 크게 나타났다. 따라서 사일리지 조제를 위한 발효제로 L. plantarum과 L. plantarum 첨가제의 사용은 사일리지의 품질 과 안정성을 더 증진할 것으로 사료 된다.
        4,000원
        4.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Arsenic (As) uptake and accumulation from agricultural soil to rice vary depending on the soil environmental conditions such as soil pH, redox potential, clay content, and organic matter (OM) content. Therefore, these factors are important in predicting changes in the uptake and accumulation of As in rice plants. Here, we studied the chemical properties of As-contaminated and/or rice straw compost (RSC)-treated soils, the growth responses of RSC-applied rice plants under As-contaminated soils, the changes in As content of soil, and the relationship between As uptake and accumulation from the RSC-treated soils to the rice organs under As-contaminated soils. Rice plants were cultivated in 30 mg kg-1 As-contaminated soils under three RSC treatments: 0 (control), 12, and 24 Mg ha-1. No significant differences were indicated in the chemical properties of pre-experimental (before transplanting rice seedling) soils, with the exception of EC, OM, and available P2O5. As the treatment of RSC under 30 mg kg-1 As-contaminated soils increased, EC, OM, and available P2O5 increased proportionally in soil. Increased soil RSC under As-contaminated soils increased shoot dry weight of rice plants at harvesting stage. As content in roots increased proportionally with RSC content, whereas As content in shoots decreased under As-contaminated soil at all stages of rice plants. Nevertheless, As accumulation were significantly decreased in both roots and shoots of RSC-treated rice plants than those in the plants treated without RSC. These results indicate that the use of RSC can mitigate As phytotoxicity and reduce As accumulation in rice plants under As-contaminated soils. Therefore, RSC can potentially be applied to As-contaminated soil for safe crop and forage rice production.
        4,000원
        5.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This in vitro study investigated the enhancement of rumen bacterial adhesion on a substrate to increase the digestibility of rice straw in Hanwoo cattle. The rice straw was pretreated with enzymes, probiotics, or ammonia, and the effects on the enhancement of bacterial adhesion and fiber degradation were analyzed using in vitro rumen fermentation. Enzyme treatment included spraying of cellulase and xylanase at 40 and 120 U per g of rice straw, respectively; Saccharomyces cerevisiae culture of 1.0×107 CFU was sprayed as a probiotic treatment per gram of rice straw; ammonia was sprayed at 0.3% per gram of rice straw. Following enzyme treatment, Fibrobacter succinogenes formed a higher adhesion colony than the control group (7.26±0.03 and 8.43±0.20) after 6h and 12h of in vitro culture (p<0.05), respectively. Attachment of Ruminococcus flavefaciens also increased following enzyme treatment (p<0.05) after 6 and 12 h compared to that of the control (5.18±0.06 and 6.60±0.15); and R. albus attachment showed a significant increase compared to that of the control (5.94±0.15) after 6 h of incubation (p<0.05). Probiotic treatment increased attachment of F. succinogenes in comparison with untreated rice straw after 6 h and 12 h of fermentation (p<0.05); R. flavefaciens attachment showed an increase only after 6 h of culture (p<0.05); R. albus was not affected. Attachment of F. succinogenes, R. flavefaciens, and R. albus increased with ammonia treatment after 6 h and 12 h (p<0.05). Dry matter digestibility was higher after the enzyme treatment (3.45±0.21 and 7.04±0.09) than in the control group(1.85±0.08 and 3.94±0.04) after 6 and 12 h of in vitro culture (p<0.05), respectively. It was also higher than that of untreated rice straw after probiotic and ammonia treatments (p<0.05). There was an increase in the enhancement levels of bacterial adhesion depending on the type of fibrolytic bacteria following enzyme, probiotic, and ammonia treatment. These treatments improved digestibility. This enhancement is considered to be greater following enzyme and ammonia treatments than with probiotics.
        4,300원
        6.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the current work, we have developed a new composite catalyst for methanol oxidation based on Ni and/or NiO incorporated in activated carbon (AC) derived from agricultural wastes (Rice straw). The new electrocatalysts based on nickel-activated carbon (Ni/AC) and nickel oxide-activated carbon (NiO/AC) composites were prepared by electroless plating technique. Physico-chemical characteristics of the composites such as structure, composition and morphology were studied by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and particle size analyzer. The electrochemical activity of the prepared composites towards methanol electrooxidation reaction (MOR) has been evaluated under alkaline conditions by cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. Among the examined electrodes, the electrochemical performance of NiO/AC preceded either Ni/ AC or Ni free AC and showed better stability. The dispersion of different forms of Ni in activated carbon in case of NiO/AC electrode is predicted to give rise to the increase in electrocatalytic activity in the potential range under study and makes it more resistant to poisoning by the byproduct of methanol oxidation. The effect of changing methanol concentrations and scan rates on the electrochemical characteristics of the modified electrode was studied and it was found that the diffusion process is controlled by methanol rather than OH− ions.
        4,800원
        7.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to research on the efficacy of chemical treatment as an effective method for reducing mycotoxin in rice straw silage. As a chemical treatment method, ammonia and sodium hydroxid were treated at 4% level of rice straws contaminated with mycotoxin, and the effects of silage storage on fungal toxin reduction, fermentation quality, and fiber digestion were evaluated. Aflatoxin B1, B2, G1, G2 and fumonisin B1, B2 as well as deoxynivalenol were not detected in all experimental groups, and ochratoxin A and zearalenone were detected. Ochratoxin A was detected lower in the chemical treatment than control (41.23 g / kg) (p<0.05). Zearalenone showed lower results in sodium hydroxide treatment (297.44 μg / kg) than control (600.33 μg / kg) and ammonia treatment (376.00 μg / kg) (p<0.05). The pH of rice straw silage was the lowest in ammonia treatment and the highest in sodium hydroxide treatment (p<0.05). The lactic acid contents of control and ammonia treatments were similar, but sodium hydroxide treatment was the lowest (p<0.05). Propionic acid was higher in the control than in the chemical treatments (p<0.05), and showed similar contents in the ammonia and sodium hydroxide treatment. Both the rumen microbial degradation rate of NDF and ADF showed the highest in sodium hydroxide treatment, followed by ammonia treatment, and the control showed the lowest level (p<0.05). Therefore, the results of this study are demonstrated to have a good effect on the treatment of ammonia and sodium hydroxide to reduce the mycotoxins and increase the rumen microbial degradation rate in the rice straw silage. Sodium hydroxide treatment was more effective in reducing mycotoxins and improving fiber degradation rate than ammonia treatment, but it is thought to have an inefficient effect on silage fermentation in rice straw silage.
        4,000원
        9.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to analyze the effectiveness of different storage periods of lactic acid bacteria (LAB)-fermented low moisture fresh rice straw silage. The low moisture fresh rice straw sample was inculcated with LAB and stored for different storage periods such as 45, 90, and 365 days, respectively. The low moisture fresh rice straw (LMFRS) silage inoculated with LAB exhibited reduction in pH throughout the fermentation as compared with the control (P<0.05). The lactic acid content was increased at the late fermentation period (90 and 365 days, respectively) in LAB inoculated LMFRS silage as compared with the control (P<0.05). In contrast, the acetic acid and butyric acid concentrations were slightly reduced in the LAB inoculated LMFRS silage sample at 90 and 365 days fermentation, respectively. Meanwhile, the non-inoculated LMFRS silage showed higher amounts of acetic acid and butyric acid at an extended fermentation with low bacterial population as compared with the LAB inoculated LMFRS silage. However, lactic acid concentration was slightly high in the non-inoculated LMFRS silage at early 45 days fermentation. Additionally, the nutrient profile such as crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), and total digestibility nutrients (TDN) were not significantly different in control and LAB inculcated samples during all fermentation. Though, the microbial population was greater in the LAB inoculated LMFRS silage as compared with the control. However, the massive population was noted in the LAB inoculated LMFRS silage during all fermentation. It indicates that the inoculated LAB is the main reason for increasing fermentation quality in the sample through pH reduction by organic acids production. Overall results suggest that the LAB inoculums are the effective strain that could be a suitable for LMFRS silage fermentation at prolonged days.
        4,000원
        14.
        2017.10 구독 인증기관·개인회원 무료
        Food fortification is defined as the addition of nutrients at levels higher than those found in the original food to improve nutritional quality. Oyster mushrooms generally contain low calcium. This present study focused on the Ca absorption efficacy of Pleurotus florida using eggshell powder, oyster shell powder and agricultural lime. Various concentrations (0%, 2%, 4%, 6%, 8% and 10%) of different calcium sources were added to the rice straw – based formulation. Duration of days from inoculation to mycelial colonization, primordial formation, fruiting body development were evaluated. Furthermore, the effect of Ca sources on the total yield and biological efficiency were also noted. Results revealed that addition of Ca sources on the formulated substrates generally lengthens time of mycelial ramification, primordial formation and fruiting body development. ESP-supplemented substrate generally increased the size of the cap but not greatly affected the stipe length and diameter of the fruiting bodies. On the other hand, the influence of addition of OSP increases cap size but decreases stipe length and diameter. Finally, for the incorporation of AGL, it was observed that size of cap of the fruiting bodies generally decreased in size, shortened the stipe and influence of AGL to the stipe diameter may vary depending on the concentration. Moreover, Ca supplementation increases the yield, biological efficiency and Ca content of P. florida. The highest yield from the substrate supplemented with eggshell powder was recorded at 8% concentration with 194.80g and biological efficiency of 36.26%. Substrate with 8% oyster shell powder resulted with the highest yield of 176.80g with biological efficiency of 33.92%. For agricultural lime supplemented substrate, the highest yield was observed in 6% concentration with 186.40g and biological efficiency of 35.51%. Optimum Ca content absorbed by P. florida was recorded in 6% ESP (140mg/100g dried sample), 10% OSP (105mg/100g dried sample) and 8% AGL (170mg/100g dried sample). These findings imply that addition of Ca on rice straw-based substrate can significantly improve yield, biological efficiency, and Ca content of the fruiting bodies.
        15.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was to research the relationships between rice straw degradation and changes of fibrolytic bacteria population during the in vitro rumen fermentation. Dry matter(DM) digestion of rice straw and population of fibrolytic bacteria were measured at the 0. 4, 8, 12 and 48 hours during the incubation. The populations of F. succinogenes. R. albus and R. flavefaciens were defined as log copy number of 16S rDNA by technical method of Quantitative real-time PCR. Total population of F. succinogenes, R. flavefaciens and R. albus was sum of bactera attached on rice straw and suspended in medium. It's population was increased with incubation, reached top level of 29.0 Log copy No at the 24 hour and then decreased. In the meantime, DM digestion of rice straw showed the higher increasement from the 8 hour to the 24 hour than from the 0 hour to the 8 hour, and then a slowdown in increasing trend of digestibility. Attachments of F. succinogenes, R. flavefaciens and R. albus were detected immediately after start of in vitro rumen incubation. At the same time, the colonized bacterial share were respectively 34.5%, 84.4% and 67.9% in total population. All of them was reached the highest colonized bacterial share above 94.7% at the 4 hour incubation. However population of attached bacteria was shown the highest level at the 12 hour or the 24 hour incubation. Kinetics of colonization were formed area of top speed from the 12 hour to the 24 hour and respectively reached 10.33, 9.28 및 8.30 Log copy No/h/g DM at the 24 hour by F. succinogenes, R. flavefaciens and R. albus. The kinetics of rice straw degradation was formed top level of 0.95% DM/h at the 24 hour. The present results gave clear evidence that degradation of rice straw was increased with the development of total fibrolytic bacteria in process of rumen fermentation. Also, their attachment was largely occurred immediately after insertion of rice straw, the colonized bacteria was actively proliferated, and then degradation of rice straw was maximized.
        4,000원
        16.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to optimize analytical methods for ochratoxin A (OTA) and zearalenone (ZEA) in rice straw silage and winter forage crops using ultra-high performance liquid chromatography (UHPLC). Samples free of mycotoxins were spiked with 50 μg/kg, 250 μg/kg, or 500 μg/kg of OTA and 300 μg/kg, 1500 μg/kg, or 3000 μg/kg of ZEA. OTA and ZEA were extracted by acetonitrile and cleaned-up using an immunoaffinity column. They were then subjected to analysis with UHPLC equipped with a fluorescence detector. The correlation coefficients of calibration curves showed high linearity (R2 ≧ 0.9999 for OTA and R2≧0.9995 for ZEA). The limit of detection and quantification were 0.1 μg/kg and 0.3 μg/kg, respectively, for OTA and 5 μg/kg and 16.7 μg/kg, respectively, for ZEA. The recovery and relative standard deviation (RSD) of OTA were as follows: rice straw = 84.23~95.33%, 2.59~4.77%; Italian ryegrass = 79.02~95%, 0.86~5.83%; barley = 74.93~97%, 0.85~9.19%; rye = 77.99~ 96.67%, 0.33~6.26%. The recovery and RSD of ZEA were: rice straw = 109.6~114.22%, 0.67~7.15%; Italian ryegrass = 98.01~109.44%, 1.65~4.81%; barley = 98~113.53%, 0.25~5.85%; rye = 90.44~108.56%, 2.5~4.66%. They both satisfied the standards of European Commission criteria (EC 401-2006) for quantitative analysis. These results showed that the optimized methods could be used for mycotoxin analysis of forages.
        4,000원
        17.
        2016.11 구독 인증기관·개인회원 무료
        The button mushroom, Agaricus bisporus, is one of the major economical crops cultivated in Korea. This mushroom showed the 5th production to 11,493 M/T in 2014. This study examined changes in decomposition-related enzyme activity secreted by the microorganisms isolated from button mushroom composts. Among the isolated microorganisms, bacterial strains CY-36 were the most dominant and had the highest enzyme activities. 16S rDNA sequencing analysis showed 99% similarity of CY-36 to Bacillus amyloliquefaciens. To define the optimum conditions for the mass production of CY-36, we have investigated optimum culture conditions and effects of various nutrient source on the bacterial growth. The optimum initial pH and temperature were determined as pH 5.0~8.0 and 30°C, respectively. The optimal culture medium for the growth was determined as follows: 2.0% dextrin, 1.0% yest extract, 0.5% NaNO3, 3 mM MgSO4, and 0.6% valine. Enzymatic activities of CMCase and PGase secreted by CY-36 were the most prominent and CMCase activity were optimal at 40°C and pH 7.0, and PGase activity were 50°C and pH 6.0. The activity of CMCase was rapidly decreased at more than 4°C and pH 5.0, and the activity of PGase was rapidly decreased at more than 30°C but didn’t affect as pH change. Accordingly, Bacillus amyloliquefaciens CY-36 was potentially useful on the fermentation stimulation and softening of rice straw in the process of fermentation for mushroom cultivation.
        18.
        2016.11 구독 인증기관·개인회원 무료
        This study examined changes in decomposition-related enzyme activity secreted by the microorganisms isolated from button mushroom composts. Among the isolated microorganisms, bacterial strains CY-24 were the most dominant and had the highest enzyme activities. 16S rDNA sequencing analysis showed 97% similarity of CY-24 to Bacillus licheniformis. To define the optimum conditions for the mass production of CY-24, we have investigated optimum culture conditions and effects of various nutrient source on the bacterial growth. The optimum initial pH and temperature were determined as pH 6.0 and 30°C, respectively. The optimal culture medium for the growth was determined as follows: 0.3% mannose, 1.5% yest extract, 0.8% (NH4)2HPO4, 2 mM MnSO4, and 0.5% asparatic acid. Enzymatic activities of CMCase and PGase secreted by CY-24 were the most prominent and CMCase activity were optimal at 50~60°C and pH 6.0, and PGase activity were 60°C and pH 6.0. The activity of CMCase was inhibited by metal ions including Ca+ and Cu+, while the activity of PGase didn’t affect. The activity of CMCase was rapidly decreased at more than 30°C and pH 7.0, and the activity of PGase didn’t affect as temperature change but was rapidly decreased at more than pH 5.0. Accordingly, This strain was potentially useful on the fermentation stimulation and softening of rice straw in the process of fermentation for mushroom cultivation.
        19.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 충남 천안 국립축산과학원 식용벼 재배지에서 2012년부터 2013년까지 정상적으로 벼 재배가 이루어지고 수확이 완료된 볏짚을 이용하여 수행하였다. 젖산균 접종 유무에 따라 볏짚사일리지의 사료가치 변화는 나타나지 않았으나 클로렐라 처리구는 대조구에 비해 현저하게 조단백질 함량이 증가하였다(p<0.05). 그리고 클로렐라 농도의 증가에 따라 조단백질 함량이 증가하는 경향을 보였다(p<0.05). 모든 처리구에서 섬유소와 TDN 함량 및 in vitro 소화율은 차이를 나타내지 않았다. 그리고 젖산균 접종 유무에 따라 볏짚사일리지의 pH 및 유기산 함량 변화는 나타나지 않았으며 클로렐라 처리구도 무처리구에 비해 pH 변화는 나타나지 않았다. 그러나 클로렐라 처리구에서 젖산함량은 무처리구에 비해 유의적으로 증가하였으며 클로렐라 농도의 증가에 따라 젖산함량이 증가하는 경향을 보였다(p<0.05). 젖산균 단독접종구의 젖산균 수는 무처리구에 비해 현저하게 증가하였으며(p<0.05), 클로렐라 농도의 증가에 따라 증가하는 경향을 보였다(p<0.05). 그러나 효모와 곰팡이 수는 비슷한 수준을 나타냈다. 그러므로 볏짚사일리지의 사료가치와 품질은 클로렐라 첨가에 의해서 향상될 수 있다.
        4,000원
        20.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 한국에서 분리한 송곳니구름버섯 (Irpex consors) 균사체의 에탄올 생산 가능성을 탐색하기 위해 수행되었다. 송곳니구름버섯의 균사체를 당이 함유된 배지에 접종하여 에탄올 생산량을 측정하였다. 포도당, 만노오스, 자일로스 등 단당류와 셀로비오스 등의 이당류가 각각 1 g 함유된 발효배지에 송곳니구름버섯의 균사체를 접종하고 배양한 결과 각각의 이들 당류에서 0.23, 0.19. 0.21, 0.17 g의 에탄올이 생산되었다. 또한 볏짚을 열수, 3% 가성소다, 3% 황산용액으로 각각 전 처리한 후 송곳니구름버섯의 균사체를 접종하고 배양한 결과 1 g의 볏짚은 각각 0.12, 0.15, 0.19 g의 에탄올로 전환되었다. 본 실험을 통해 송곳니구름버섯의 균사체는 여러 종류의 환원당을 이용해 에탄올을 생산할 수 있는 것은 물론 열수, 가성소다 및 황산으로 전 처리한 볏짚을 에탄올로 전환하는 것도 가능한 것으로 나타났다. 따라서 송곳니구름버섯 균사체의 에탄올 생산 수율을 본 실험의 결과 보다 높일 수 있다면 당류뿐 만아니라 볏짚을 비롯한 리그닌셀룰로오스의 바이오매스를 이용해 바이오에탄올을 효율적으로 생산해 우리나라 에너지 수요를 자급하는데 큰 기여를 할 수 있을 것으로 사료된다.
        4,000원
        1 2 3 4