• Title/Summary/Keyword: PV.1

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Butt-fusing Procedures and Qualifications of High Density Polyethylene Pipe for Nuclear Power Plant Application (원자력발전소 적용 고밀도 폴리에틸렌 배관의 맞대기 융착절차 및 검증절차 분석)

  • Oh, Young-Jin;Park, Heung-Bae;Shin, Ho-Sang
    • Journal of Welding and Joining
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    • v.31 no.6
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    • pp.1-7
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    • 2013
  • In nuclear power plants, lined carbon steel pipes or PCCPs (pre-stressed concrete cylinder pipes) have been widely used for sea water transport systems. However, de-bonding of linings and oxidation of PCCP could make problems in aged NPPs (nuclear power plants). Recently at several NPPs in the United States, the PCCPs or lined carbon steel pipes of the sea water or raw water system have been replaced with HDPE (high density polyethylene) pipes, which have outstanding resistance to oxidation and seismic loading. ASME B&PV Code committee developed Code Case N-755, which describes rules for the construction of buried Safety Class 3 polyethylene pressure piping systems. Although US NRC permitted HDPE materials for Class 3 buried piping, their permission was limited to only 10-year operation because of several concerns including the quality of fusion zone of HDPE. In this study, various requirements for fusion qualification test of HDPE and some regulatory issues raised during HDPE application review in foreign NPPs are introduced.

Breeding for Resistance to Bacterial Blight in Rice (벼흰잎마름병 저항성 품종 육성 및 금후 연구 방향)

  • Shin, Mun-Sik;Kim, Ki-Young;Park, Hyun-Su;Ko, Jae-Kwon
    • Korean Journal of Breeding Science
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    • v.43 no.4
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    • pp.241-251
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    • 2011
  • Bacterial blight(BB) caused by Xanthomonas oryzae pv. oryzae(Xoo) is one of the most economically destructive bacterial diseases of rice in worldwide. Utilization of resistant cultivars carrying resistant gene(s) is relatively an effect method to control this disease. About 34 resistant genes for BB resistance have been identified in many countries. Among them, Xa1 and Xa3 genes against bacterial blight have been incorporated into improved korean japonica rice varieties. Now, Ilmi carrying Xa1 gene and severial cultivars carrying Xa3 gene are widely grown in our country. In recent year, xa5, Xa21 and Xa23 genes are using in rice breeding programs for japonica resistant cultivars to bacterial blight. Resistant cultivars incorporated with a diverse single gene and two, three, or the more major gene necessite in the future.

Detection of RNA Mycoviruses in Wild Strains of Lentinula edodes in Korea

  • Kim, Eunjin;Park, Mi-Jeong;Jang, Yeongseon;Ryoo, Rhim;Ka, Kang-Hyeon
    • The Korean Journal of Mycology
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    • v.49 no.3
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    • pp.285-294
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    • 2021
  • In general, mycoviruses remain latent and rarely cause visible symptoms in fungal hosts; however, some viral infections have demonstrated abnormal mycelial growth and fruiting body development in commercial macrofungi, including Lentinula edodes. Compared to other cultivated mushrooms, L. edodes is more vulnerable to viral infections as it is still widely cultivated under near-natural conditions. In this study, we investigated whether Korean wild strains of L. edodes were infected by RNA mycoviruses that have previously been reported in other parts of the world (LeSV, LePV1, LeV-HKB, LeNSRV1, and LeNSRV2). Using specific primer sets that target the RNA-dependent RNA polymerase genes of each of the RNA mycovirus, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect viral infection. Viral infection was detected in about 90% of the 112 wild strains that were collected in Korea between 1983 and 2020. Moreover, multiple infections with RNA mycoviruses were detected in strains that had normal fruiting bodies. This work contributes to our understanding of the distribution of RNA mycoviruses in Korea and the impact of multiple viral infections in a single strain of L. edodes.

Removal of reactive black 5 dye by using polyoxometalate-membrane

  • Topaloglu, Ali Kemal;Yildirim, Yilmaz
    • Membrane and Water Treatment
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    • v.12 no.1
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    • pp.23-35
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    • 2021
  • A POM-membrane was fabricated by immobilizing a keggin type polyoxometalate (POM) H5PV2Mo10O40 onto the surface of microporous flat-sheet polymeric polyvinylidene fluoride (PVFD) membrane using a chemical deposition method. The POM-membrane was characterized by FT-IR, SEM and EDX to confirm existing of the POM onto the membrane surface. The POM-membrane was used to remove an anionic textile dye (Reactive Black 5 named as an RB5) from aqueous phases with a cross-flow membrane filtration and a batch adsorption system. The dye removal efficiency of the POM-membrane using the cross-flow membrane filtration system and the batch adsorption system was about 88% and 98%, respectively. The influence factors such as contact time, adsorbent dosage, pH, and initial dye concentration were investigated to understand the adsorption mechanism of the RB5 dye onto the POM-membrane. To find the best fitting isotherm model, Langmuir, Freundlich, BET and Harkins-Jura isotherm models were used to analyze the experimental data. The isotherm analysis showed that the Langmuir isotherm model was found to the best fit for the adsorption data (R2 = 0.9982, qmax = 24.87 mg/g). Also, adsorption kinetic models showed the pseudo second order kinetic model was found the best model to fit the experimental data (R2 = 0.9989, q = 8.29 mg/g, C0 = 15 ppm). Moreover, after four times regeneration with HNO3 acid, the POM-membrane showed high regenerability without losing dye adsorption capacity.

Isolation and Identification of Ice Nucleation Active Fusarium Strains from Rapid Apple Declined Trees in Korea

  • Avalos-Ruiz, Diane;Ten, Leonid N.;Kim, Chang-Kil;Lee, Seung-Yeol;Jung, Hee-Young
    • The Plant Pathology Journal
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    • v.38 no.4
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    • pp.403-409
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    • 2022
  • In biological particles such as Fusarium species, ice nucleation activity (INA) has been observed. Fusarium strains isolated from apple declined trees in Korea were identified with a multilocus sequence analysis using the tef1 and rpb1 genes. Droplet-freezing and tube-freezing assays were used to determine the INA of the strains, using Pseudomonas syringae pv. syringae KACC 21200 as a positive control and resulting in seven INA+ fungal strains that were identified as F. tricinctum (KNUF-21-F17, KNUF-21-F18, KNUF-21-F29, KNUF-21-F32, KNUF-21-F38, KNUF-21-F43, and KNUF-21-F44). The effect of Fusarium INA+ KNUF-21-F29 was compared to that of INA- strains on Chrysanthemum morifolium cv. Shinma explants. A higher callus formation and no-shoot formation were observed, suggesting that fungal INA could play a role in cold injuries and be a factor to consider in rapid apple decline. To the best of our knowledge, this is the first report of INA fungal strains isolated in Korea.

Negative evidence on the transgenerational inheritance of defense priming in Arabidopsis thaliana

  • Yun, Se-Hun;Noh, Bosl;Noh, Yoo-Sun
    • BMB Reports
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    • v.55 no.7
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    • pp.342-347
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    • 2022
  • Defense priming allows plants to enhance their immune responses to subsequent pathogen challenges. Recent reports suggested that acquired resistances in parental generation can be inherited into descendants. Although epigenetic mechanisms are plausible tools enabling the transmission of information or phenotypic traits induced by environmental cues across generations, the mechanism for the transgenerational inheritance of defense priming in plants has yet to be elucidated. With the initial aim to elucidate an epigenetic mechanism for the defense priming in plants, we reassessed the transgenerational inheritance of plant defense, however, could not observe any evidence supporting it. By using the same dipping method with previous reports, Arabidopsis was exposed repeatedly to Pseudomonas syringae pv tomato DC3000 (Pst DC3000) during vegetative or reproductive stages. Irrespective of the developmental stages of parental plants that received pathogen infection, the descendants did not exhibit primed resistance phenotypes, defense marker gene (PR1) expression, or elevated histone acetylation within PR1 chromatin. In assays using the pressure-infiltration method for infection, we obtained the same results as above. Thus, our results suggest that the previous observations on the transgenerational inheritance of defense priming in plants should be more extensively and carefully reassessed.

Building Integrated Photovoltaics: Technical and Aesthetic Prospects

  • Polgampola Chamani Madara;Hasnain Yousuf;Muhammad Aleem Zahid;Suresh Kumar Dhungel;Youngkuk Kim;Junsin Yi
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.2
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    • pp.154-163
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    • 2024
  • The energy demand in the world is expected to exceed 740 million TJ by 2040 and our dependence on fossil fuels needs to be switched to sustainable and renewable energy sources like solar energy. Building Integrated Photovoltaic (BIPV) is one of the best approaches to extracting solar energy. There are more than 200 BIPV products in the market currently but when it comes to integrating these products into the technical aspects such as buildings' structural integrity, thermal, daylight retainment and aesthetic prospects to be considered. The share of BIPV integration potential of different building types in the world of residential, agricultural, industrial, commercial and other buildings account for 66%, 4.8%, 8.1%, 19.9%, and 1.2% accordingly. Many solar technologies developed to achieve architectural requirements, but the main problem is the trade-off between efficiency and aesthetic appeal, which is less than 10% in coloured and transparent solar modules. This paper discusses the different applications of solar photovoltaics (PV) in building architecture, technical requirements, and different module technologies. The article provides a comprehensive guide for researchers and designers working on the development of BIPV integrations.

Durability Evaluation Study of Re-manufactured Photovoltaic Modules (재 제조 태양광모듈의 내구성능 평가 연구)

  • Kyung Soo Kim
    • Current Photovoltaic Research
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    • v.12 no.1
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    • pp.17-23
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    • 2024
  • Photovoltaic (PV) power generation is the world's best and largest renewable energy that generates electricity with infinite sunlight. Solar cell modules are a component of photovoltaic power generation and must have a long-term durability of at least 25 years. The development of processes and equipment that can be recovered through the recycling of metals and valuable metals when the solar module's lifespan is over has been completed to the level of commercialization, but few processes have been developed that require repair due to initial defects. This is mainly due to the economic problems caused by remaking. However, if manufacturing processes such as repairing solar cell modules that have been proven to be early defects are established and the technical review of long-term reliability and durability reaches a certain level, it is considered that it will be a recommended process technology for environmental economics. In this paper, assuming that a defective solar cell module occurs artificially, a manufacturing process for replacement of solar cells was developed, and a technical verification of the manufacturing technology was conducted through long-term durability evaluation in accordance with KS C 8561. Through this, it was determined that remanufacturing technology for solar cell replacement of solar cell modules that occurred in a short period of time after installation was possible, and the research results were announced through a journal to commercialize solar modules using manufacturing technology in the solar market in the future.

Isolation and In vitro and In vivo Antifungal Activity of Phenylacetic acid Produced by Micromonospora aurantiaca Strain JK-1

  • Kim, Hyo-Jin;Hwang, In-Sun;Kim, Beom-Seok;Hwang, Byung-Kook
    • The Plant Pathology Journal
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    • v.22 no.1
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    • pp.75-89
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    • 2006
  • The actinomycete strain JK-1 that showed strong inhibitory activity against some plant pathogenic fungi and oomycetes was isolated from Jung-bal Mountain in Ko-yang, Korea. The strain JK-1 produced spores singly borne on sporophores and the spores were spherical and 0.9-1.2 11m in diameter. The cell wall of the strain JK-1 contained meso-diaminopimelic acid. The actinomycete strain JK-1 was identified as the genus Micromonospora based on the morphological, physiological, biochemical and chemotaxonomic characteristics. From the 168 rDNA analysis, the strain JK-1 was assigned to M aurantiaca. The antibiotic MA-1 was purified from the culture broth of M aurantiaca JK-1 using various purification procedures, such as Diaion HP20 chromatography, C18 flash column chromatography, silica gel flash column chromatography and Sephadex LH-20 column chromatography. $^{1}H-$, $^{13}C-NMR$ and EI mass spectral analysis of the antibiotic MA-1 revealed that the antibiotic MA-1 is identical to phenylacetic acid. Phenylacetic acid showed in vitro inhibitory effects against fungal and oomycete pathogens Alternaria mali, Botrytis cinerea, Magnaporthe grisea, Phytophthora capsici and yeast Saccharomyces cerevisiae at < 100 $\mug$ $ml^{-1}$. In addition, phenylacetic, acid completely inhibited the growth of Sclerotinia sclerotiorum, Bacillus subtilis, Candida albicans, Xanthomonas campestris pv. vesicatoria at < $\mug$ $ml^{-1}$. Phenylacetic acid strongly inhibited conidial germination and hyphal growth of M grisea and C. orbiculare. Phenylacetic acid showed significantly high levels of inhibitory' effect against rice blast and cucumber anthracnose diseases at 250 $\mug$ $ml^{-1}$. The control efficacies of phenylacetic acid against the two diseases were similar to those of commercial compounds tricyclazole, iprobenfos and chlorothalonil .n the greenhouse.

Evaluation of Power Generation Performance for Bifacial Si Photovoltaic Modules installed on Different Artificial Grass Floors (인조잔디 바닥종류에 따른 양면수광형 실리콘 태양광 모듈의 발전성능 평가)

  • Yoo, Younggyun;Seo, Yeongju;Park, Dohyun;Kim, Minsu;Jang, Hojun;Kwon, Young Hoon;Hwangbo, Chul;Kim, Woo Kyoung;Chang, Sungho
    • Journal of Energy Engineering
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    • v.27 no.3
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    • pp.1-9
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    • 2018
  • In this study, the outdoor evaluation test was performed to characterize the highly-reflective artificial grass to be used for bifacial photovoltaic (PV) power generation system. The 60-cell n-type Si monofacial and bifacial PV modules were employed, where two types of bifacial modules were equipped with split-type and box-type junction boxes, respectively. The results showed that the split-type junction box improved the rear-side power production and thus energy yield of bifacial module compared to the box-type junction box causing the shadow effect. Highly-reflective artificial grass achieved relatively high albedo of 0.18, and excellent bifacial gain of 33%, compared to conventional artificial grass with an albedo of 0.14-0.15, and bifacial gain of 29-30%.