• Title/Summary/Keyword: PV

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Experimental Analysis of Ventilation Effect on the Performance of Building-Integrated PV Solar Roof (건물통합형 PV Solar Roof의 통풍효과 실험분석)

  • Kim, Jin-Hee;Lee, Kang-rock;Kim, Jun-Tae
    • Journal of the Korean Solar Energy Society
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    • v.26 no.1
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    • pp.73-79
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    • 2006
  • The integration of PV modules into building facades or roof could raise PV module temperature that results in the reduction of electrical power generation. Lowering operating temperature of PV module is important in this respect, and PV module temperature should be considered more accurately, for building-integrated PV(BIPV) systems in predicting their performance. This paper describes a BIPV solar roof design and verifies its performance through experiment In relation to the effect of ventilation in space between PV module and roof surface. The results showed that the ventilation in the space had a positive effect in lowering the module temperature of the BIPV solar roof that enhanced the performance of its electricity generation.

PV모듈의 전면 유리 두께 변화에 따른 기계강도 특성

  • Choe, Ju-Ho;Jeong, Tae-Hui;Gang, Gi-Hwan;Jang, Hyo-Sik
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.297.1-297.1
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    • 2013
  • PV모듈은 다수의 태양전지를 상호 연결한 후 라미네이션(Lamination)공정을 통해 오랜 시간 견딜 수 있는 하나의 구조물로 만든 것이다. 외부환경 노출되어 장시간 발전하는 PV모듈은 설하중 풍하중 등 다양한 응력을 받는다. 이러한 외부 응력은 PV모듈 내부의 태양전지를 파손시켜 발전 출력의 감소를 발생 시킬 수 있다. 따라서 기계적 신뢰성을 보장하는 것은 매우 중요하며, PV모듈의 기계적 강도를 향상시키기 위한 연구가 활발히 진행되어지고 있다. 따라서, 본 논문에서는 PV모듈의 기계적, 물리적 변형을 최소화 하고자 PV모듈 전면에 사용되는 강화유리의 두께를 증가시켜 기계하중 시험을 진행하였다. 실험은 K SC IEC 61215의 PV모듈 인증시험 기준에서 제시하는 기계강도 시험과 동일한 방식으로 시험을 실시 하였으며, 전면유리 두께가 3.2 mm, 4 mm, 5 mm인 PV모듈을 사용하여 하중에 대한 최대변형과 출력 변화를 관찰하였으며, EL (electroluminescence) 측정을 통하여 기계강도 실험전 후의 모듈 내부 태양전지 파손 여부를 확인하였다. 이러한 결과는 PV모듈에 대한 내풍압 및 적설하중 등 Field에서 발생될 수 있는 물리적 내구성능을 분석하는데 많은 도움이 될 수 있다.

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Comparative Analysis of Korean and Japanese Strains of Pseudomonas syringae pv. actinidiae Causing Bacterial Canker of Kiwifruit

  • Lee, Jae-Hong;Kim, Jung-Ho;Kim, Gyoung-Hee;Jung, Jae-Sung;Hur, Jae-Sung;Koh, Young-Jin
    • The Plant Pathology Journal
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    • v.21 no.2
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    • pp.119-126
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    • 2005
  • Genomic and phenotypic characteristics of the bacterial strains of Pseudomonas syringae pv. actinidiae and P. syringae pv. syringae collected from several kiwifruit orchards of Korea were investigated and compared with those from Japan to elucidate their phylogenic relationships. All the strains of P. syringae pv. actinidiae and pv. syringae tested were sensitive to copper sulfate but Korean and Japanese strains showed quite different responses to streptomycin. Korean strains were sensitive to streptomycin, but most of the Japanese strains of P. syringae pv. actinidiae were highly resistant to streptomycin. Japanese strains were also relatively more resistant to oxytetracycline than Korean strains. Plasmid profiles were not valuable to distinguish Korean strains of P. syringae pv. actinidiae frombJapanese strains. One or more indigenous plasmids with more than 15 kb in size were detected in all strains of P. syringae pv. actinidiae, but the number and sizes of plasmids harbored in P. syringae pv. actinidiae were variable among the strains regardless of their geographic origins. There also observed no significant relationship among resistance levels of the strains of P. syringae pv. actinidiae to antibiotics, their pathogenicity and plasmid profiles. RAPD profiles were useful to analyze the strains of P. syringae pv. actinidiae and pv. syringae. All the strains of P. syringae pv. actinidiae fell into a wide cluster separated from the strains of P. syringae pv. syringae, but Korean strains of P. syringae pv. actinidiae were separated from Japanese strains. The results support that Korean and Japanese strains of P. syringae pv. actinidiae may have different phylogenic origins.

Development and Evaluation of PCR-Based Detection for Pseudomonas syrinage pv. tomato in Tomato Seeds (토마토 종자로부터 PCR을 이용한 Pseudomonas syringae pv. tomato의 검출)

  • Cho, Jung-Hee;Yim, Kyu-Ock;Lee, Hyok-In;Yea, Mi-Chi;Cha, Jae-Soon
    • Research in Plant Disease
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    • v.17 no.3
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    • pp.376-380
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    • 2011
  • The bacterial speck of tomato caused by Pseudomonas syringae pv. tomato leads to serious economic losses especially on fruits of susceptible genotype. Thus, Pseudomonas syringae pv. tomato is a plant quarantine bacterium in many countries including Korea. In this study, we developed specific PCR assays for detection of the bacterium from tomato seeds. A specific primer set is designed from the hrpZ gene for specific detection of Pseudomonas syringae pv. tomato. A 501 bp PCR product corresponding to hrpZ gene was amplified only form Pseudomonas syringae pv. tomato strains, but no PCR product was amplified from other tomato bacterial pathogens, such as Pseudomonas syringae pv. glycinea, P. syringae pv. maculicola, P. syringae pv. atropurpurea, P. syringae pv. morsprunorum, and from other P. syringae pathovar strains. The nested-PCR primer set corresponding to an internal fragment of the 501 bp sequence (hrpZ) gine was used to specific detection of Pseudomonas syringae pv. tomato in tomato seed. A 119 bp PCR product using nested PCR primer was highly specific and sensitive to detect low level of Pseudomonas syrigae pv. tomato in tomato seeds. We believe that the PCR assays developed in this study is very useful to detect Pseudomonas syringae pv. tomato from the tomato seeds.

Morphological and morphometric study of pulmonary vein anatomy in relation to cardiac invasive and electrophysiological procedures

  • Harshal Oza;Bhavik Doshi
    • Anatomy and Cell Biology
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    • v.56 no.4
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    • pp.428-434
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    • 2023
  • Pulmonary veins (PVs) and their myocardial sleeves play an important role in the development of atrial fibrillation. Hence, detailed knowledge of PV anatomy is required to improve the procedural success rate and prevent complications during cardiac procedures. The aim of this study was to evaluate the PV anatomy along with anatomical variations in the Indian population. Total 100 formalin fixed cadaveric hearts were examined. The number and pattern of the PVs were observed along with the measurement of their horizontal and vertical diameters. The ovality index for each PV was calculated. Classical PV pattern was observed in 62% cases. Variant pattern like additional right middle PV pattern and left common PV pattern were found in 20% and 10% cases respectively. A separate pattern with presence of both right middle PV and left common PV was observed in 6% cases. In the classical pattern right superior PV was the largest followed by right inferior, left superior and left inferior PV. The additional right middle PV had the smallest diameter whereas the left common PV had the largest diameter. Almost all the veins had greater vertical diameters in comparison to horizontal diameters. The variant PVs were oval and had greater ovality index compared to the normal PVs. In classical pattern 54.8% hearts whereas in variant pattern 79% hearts had one or more oval PV. The given data can help clinicians for planning and execution of various interventional and electrophysiological procedures involving PVs.

PCR-Based Sensitive Detection and Identification of Xanthomonas oryzae pv. oryzae (중합효소연쇄 반응에 의한 벼 흰잎마름병균의 특이적 검출)

  • Lee, Byoung-Moo;Park, Young-Jin;Park, Dong-Suk;Kim, Jeong-Gu;Kang, Hee-Wan;Noh, Tae-Hwan;Lee, Gil-Bok;Ahn, Joung-Kuk
    • Microbiology and Biotechnology Letters
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    • v.32 no.3
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    • pp.256-264
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    • 2004
  • A new primer set was developed for the detection and identification of Xanthomonas oryzae pv. oryzae, the bacterial leaf blight (BLB) pathogen in rice plant. The nucleotide sequence of hpaA gene was determined from X. o. pv. oryzae str. KACC10331, and the sequence information was used to design primers for the application of the polymerase chain reaction (PCR). The nucleotide sequence of hpaA from X. o. pv. oryzae str. KACC 10331 was aligned with those of X. campestris pv. vesicatoria, X. campestris pv. campestris, X. axonopodis pv. citri, and X. axonopodis pv. glycines. Based on these results, a primer set(XOF and XOR) was designed for the specific detection of hpaA in X. o. pv. oryzae. The length of PCR products amplified using the primer set was 534-bp. The PCR product was detected from only X. o. pv. oryzae among other Xanthomonas strains and reference bacteria. This product was used to confirm the conservation of hpaA among Xanthomonas strains by Southern-blotting. Furthermore, PCR amplification with XOF and XOR was used to detect the pathogen in an artificially infected leaf. The sensitivity of PCR detection in the pure culture suspension was also determined. This PCR-based detection methods will be a useful method for the detection and identification of X. o. pv. oryzae as well as disease forecasting.

Changes in volatile compounds of persimmon vinegar during aging (숙성기간에 따른 감식초의 휘발성 성분 변화)

  • Chung, Woo-Cheol;Baek, Hyung-Hee;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.51 no.5
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    • pp.438-446
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    • 2019
  • To investigate the changes in volatile compounds of persimmon vinegar (PV) during aging, PVs aged for 3-25 years were analyzed using solid-phase microextraction-gas chromatography-mass spectrometry. In total, 90 volatile compounds were identified, and acids and esters were the most abundant, followed by ketones and alcohols. The concentration of acetic acid ranged from 8,925.0 to 26,132.3 ng/mL, depending on the aging period. Ethyl acetate concentration ranged from 32.5 to 50,681.7 ng/mL and ethanol was present only in PV aged for 3 years (PV-3). The volatile compound content was the highest in PV-3. The volatile profiles of PV aged for 22 years (PV-22) and 25 years (PV-25) were considerably similar. Acids were the most predominant in PV-15, PV-22, and PV-25, whereas esters were abundant in PV-3. The contents of acids, alcohols, and esters decreased, while the aldehyde and ketone content increased with aging.

Computed tomographic evaluation of portal vein indices in cats with the extrahepatic portosystemic shunts

  • Eunji Jeong;Jin-Young Chung;Jin-Ok Ahn;Hojung Choi;Youngwon Lee;Kija Lee;Sooyoung Choi
    • Journal of Veterinary Science
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    • v.25 no.3
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    • pp.37.1-37.10
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    • 2024
  • Importance: The portal vein to aorta (PV/Ao) ratio is used to assess the clinical significance of extrahepatic portosystemic shunt (EHPSS). Previous studies using computed tomography (CT) were conducted in dogs but not in cats. Objective: This study aimed to establish normal reference values for PV indices (PV/Ao ratio and PV diameter) in cats and determine the usefulness of these for predicting symptomatic EHPSS. Methods: This study included 95 dogs and 114 cats that underwent abdominal CT. The canine normal (CN) group included dogs without EHPSS. The cats were classified into feline normal (FN, 88/114), feline asymptomatic (FA, 16/114), and feline symptomatic (FS, 10/114) groups. The PV and Ao diameters were measured in axial cross-sections. Results: The group FN had a higher PV/Ao ratio than the group CN (p < 0.001). Within the feline groups, the PV indices were in the order FN > FA > FS (both p < 0.001). The mean PV diameter and PV/Ao ratio for group FN were 5.23±0.77 mm and 1.46±0.19, respectively. The cutoff values between groups FN and FS were 4.115 mm for PV diameter (sensitivity, 100%; specificity, 97.7%) and 1.170 for PV/Ao ratio (90%, 92.1%). The cutoff values between group FA and FS were 3.835 mm (90%, 93.8%) and 1.010 (70%, 100%), respectively. Conclusions and Relevance: The results demonstrated significant differences in PV indices between dogs and cats. In cats, the PV/Ao ratio demonstrated high diagnostic performance for symptomatic EHPSS. The PV diameter also performed well, in contrast to dogs.

Output Control Simulation of PV-AF Generation System under Various Weather Conditions (다양한 기상조건하에서의 AF기능을 갖는 태양광발전시스템의 출력제어 시뮬레이션)

  • Seong, Nak-Gueon;Park, Min-Won;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.1364-1366
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    • 2002
  • The Photovoltaic(PV) generation system is a promising source of energy for the future. Since the need for renewable energy has been increased, the research of PV generation system has also been progressed. Recently, cost down of PV generation system has been accomplished and practical technologies of the solar energy developed, Moreover, grid connected PV generation system are becoming actual and general. Operational technology of the grid connected PV generation system is being a hot issue. Power output of PV system is directly affected by wether conditions. When AC power supply is needed, power conversion by an inverter and a MPPT control are necessary. In this paper, for stability improvement of PV generation system. Active filter(AF) function is added to PV generation system, and simulations of PV-AF system under various weather conditions are performed.

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A Study on the Algorithm for Interconnection of PV System on Power Distribution System Considering Reliability (신뢰도를 고려한 태양광시스템의 배전계통 연계 알고리즘에 관한 연구)

  • Moon, Jong-Fil
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.60 no.4
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    • pp.241-245
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    • 2011
  • In this paper, when photovoltaic (PV) systems are connected to power distribution system, most effective capacity and connected-point of PV system are presented considering power distribution system reliability. The reliability model of PV system is presented considering the duration of sunshine. Also the model of time-varying load and reliability test system bus2 model are used. To simulate the effects of PV system, various cases are selected; (1) base case which is no connection of PV system to power distribution system when faults are occurred, (2) 3MW case which is 3[MW] connection of PV system (3) 4[MW] case, and (4) 20[MW] case which is 20[MW] connection of PV system to the bus of power distribution system. The capacity limit of connected PV system is settled to 14[MW] for all cases except case 4. The reliability for residential, general, industrial, and educational customer is evaluated.