• Title/Summary/Keyword: life cycle of plants

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The Software Verification and Validation Tasks for a Safety Critical System in Nuclear Power Plants

  • Cheon Se Woo;Cha Kyung Ho;Kwon Kee Choon
    • International Journal of Safety
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    • v.3 no.1
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    • pp.38-46
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    • 2004
  • This paper introduces the software life-cycle V&V (verification and validation) tasks for the KNICS (Korea nuclear instrumentation and control system) project. The objectives of the V&V tasks are mainly to develop a programmable logic controller (PLC) for safety critical instrumentation and control (I&C) systems, and then to apply the PLC to developing the prototype of an engineered safety features-component control system (ESF-CCS) in nuclear power plants. As preparative works for the software V&V, various kinds of software plans and V&V task procedures have been developed according to the software life-cycle management. A number of software V&V tools have been adopted or developed to efficiently support the V&V tasks. The V&V techniques employed in this work include a checklist-based review and inspection, a requirement traceability analysis, formal verification, and life-cycle based software testing.

Evaluation of monthly environmental loads from municipal wastewater treatment plants operation using life cycle assessment

  • Piao, Wenhua;Kim, Ye-jin
    • Environmental Engineering Research
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    • v.21 no.3
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    • pp.284-290
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    • 2016
  • Life cycle assessment (LCA) methodology can be used to assess impacts on the environment that might be generated during treatment of wastewater and sludge treatment. In this work, LCA methodology was suggested to evaluate monthly environmental impact of wastewater treatment plants (WWTPs). Two field scale WWTPs, A2/O process and conventional activated sludge process (CAS), were selected as target plants and the operational data were collected from those plants. As the function units, the unit volume of treated wastewater of $1m^3$ and 1 kg T-N eq. removed were selected. The environmental effect of target WWTPs operation were assessed as impact categories such as global warming potential, eutrophication potential, and so on. From monthly profiles of each index, it was shown that the environmental impact of WWTPs has seasonal patterns influenced by the influent flow rate variation causing higher impacts in winter than summer. This is due to the fact that there were no significant increase in the electricity consumption and chemical usage during the summer while the treated volume of wastewater was increased.

Chilling Tolerance of Photosynthesis in Plants is Dependent on the Capacity to Enhance the Levels of the Xanthophyll Cycle Pigments in Response to Cold Stress

  • Kim, Hyun-Ju;Kang, In-Soon;Lee, Chin-Bum;Lee, Choon-Hwan;Cho, Sung-Ho;Moon, Byoung-Yong
    • Journal of Photoscience
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    • v.12 no.1
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    • pp.33-39
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    • 2005
  • Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.

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Life cycle of Kunugia yamadai Nagano (Lepidoptera, Lasiocampidae) in Korea (도토리나방(나비목, 솔나방과)의 생활사)

  • 박철하;변봉규
    • Korean journal of applied entomology
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    • v.36 no.1
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    • pp.73-76
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    • 1997
  • This study was conducted to investigate the life cycle of Kunugia yamadai Nagano attacking Qriercrrs spp. in Chungju area, Korea during 1987-1989. The moth had one generation a year. Host plants of the species were Quercus acutissima, Q. serrata, Q. aliena, and Castanea crenata. And Q. dentata T., and Q variahilis B. were newly recognized as host plants of the insect. Young larvae were hatched from the overwintered eggs and fed on the leaves from late April to early August which took ahout 3 months. In mid-August, the fully grown larva made a rough cocoon and pupated at the ground debris or dense grass. The moths emerged from September to late October with a peak around mid-October. Female oviposited 121 eggs on average mostly on the bark of host plants at 131 cm ahove the ground.

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Life History, Ginseng Damage and Chemical Control of the Field Slug, Deroceras varsans A, Adams (들민달팽이의 생활사와 인삼의 피해 및 약제 방제)

  • 김기황;오승환
    • Journal of Ginseng Research
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    • v.14 no.3
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    • pp.421-426
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    • 1990
  • Field and laboratory works were conducted to Investigate the life history, ginseng damage and chemical control effect of the field slug, Deroceras varians A. Adams. D. varians laid eggs from April to June, but a small number of eggs were also found from July to September in the field. Most young slugs grew through the slimmer months to maturity by October. overwintered beneath the moist soil surface, and began feeding and egg-laying in the following April. indicating that D varians have a life cycle in a year. Damage of ginseng plants by D. varina occurred mainly from late April to mid May in the 3rd to 5th year ginseng fields with rice-straw mulching. It seems that this damage is caused by the adults in oviposition periods and related to rice-straw mulching of ginseng fields. In the experiment, ethoprop 5% granule and metaldehyde 6% bait showed relatively high effectiveness in the control of D. varians adults. Bordeaux mixture was more effective when the chemical was sprayed after infestation of the slug than before the infestation and when the 6-12 mixture was used.

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Validating the Applicability of a Simplified Correlation Method for Economic Evaluation of Cooling Plants (냉방열원기기의 경제성 평가를 위한 간이계산법의 적용성 검토)

  • 김영섭;김강수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.10
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    • pp.854-862
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    • 2002
  • In the previous research, a simplified correlation method was developed as an easy prediction tool for comparing energy use of cooling plants. The purpose of this paper is to test the applicability of this method for economic evaluation with two zones of a 20-story commercial building in Seoul. The results of this method were compared with the DOE-2 simulation and actual measured data. Then, Comparisons of life cycle cost were carried out for three types of cooling plants. Testing of one zone showed good agreement of within 10% error in cooling energy use and within 2% error in LCC. But testing of the other zone indicated that the use of this method were invalid when input variables were used beyond its valid range.

Biology of a predatory bug Eocanthecona furcellata Wolff (Hemiptera : Pentatomidae) on Vapourer tussock moth larvae: a major pest of tasar silkworm food plants

  • Siddaiah, Aruna Ambadahalli;Devi, Aribam Reema
    • International Journal of Industrial Entomology and Biomaterials
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    • v.30 no.1
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    • pp.26-30
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    • 2015
  • Tropical Tasar culture is forest and agro-based activity that covers agricultural and industrial activity. Tasar silk is produced by the silkworm, Antheraea mylitta which is polyphagous in nature. A large number of pests are reported to attack both the host plant as well as silkworm. As the rearing is conducted outdoor silkworms are exposed to attack of various pests during their life cycle. Eocanthecona furcellata (Hemiptera: Pentatomidae) is the major predator of tasar silkworm during young age rearing. Both nymphs and adults of the stink bug suck the heamolymph of silkworm leading to death. The present work was undertaken to study the life cycle of E. furcellata on larvae of vapourer tussock moth which is a major pest of tasar host plants. The incubation period, nymphal duration and total developmental period from egg to adult was $8.0{\pm}0.45d$, $16.0{\pm}3.24$ and $22.0{\pm}4.20d$, respectively. Pre-oviposition, oviposition and longevity of male and female stink bug was $3.20{\pm}0.38$, $17.60{\pm}1.86$, $42.40{\pm}1.94$, $37.00{\pm}3.18d$, respectively. Analysis of the data revealed no significant difference in life cycle of the predator when provided silkworm and vapourer tussock moth larvae as hosts. Which clearly indicates that E. furcellata can multiply on vapourer tussock moth larvae during non rearing periods. Adoption of recommended pest control measures for defoliators of tasar host plants during non-rearing periods will help in reducing the incidence of host plant pests and also in reducing the incidence of stink bug during rearing season. During the study it was also observed that larvae semilooper, boll headed caterpillar and nymphs of leaf hopper serve as alternate/secondary hosts to E. furcellata during non rearing seasons.

Effect of Plant Life Cycle on Plant Settlement in Diverse Water Level (다양한 수위 조건에서 식물 생활형이 식물 정착에 미치는 영향)

  • Nam, Jong Min;Cho, Hyun Seung;Kim, Jae Geun
    • Journal of Wetlands Research
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    • v.17 no.1
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    • pp.19-25
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    • 2015
  • The purpose of this study is to reveal the effect of plant life cycle to plant settlement by 1 year monitoring. The subjects of monitoring are the plants (3 plant life cycle, 9 taxa) well established in the mesocosm. 18 mesocosms were divided into 3 sets and water levels were maintained at 0, 20 and 60 cm during 16 weeks from mid-May, respectively and at 0 cm except these 16 weeks. Height and population size of transplanted perennial plants (Scirpus tabernaemontani, Zizania caduciflora, Typha (Typha angustifolia and Typha orientalis)) at 1st year were not affected by diverse water level, though any more seedlings of these species were not settled at this condition. In contrast, water level condition strong influenced annual and biennial plant, relatively. As a result, timing and duration of flooding have great effect on successful settlement of annual and biennial plant without rhizome.

Host Plants and Lifr Cycle of Rice Black Bug, Scotinophara lurida BURMEISTER(Hemiptera: Pentatomidae) (벼먹노린재(Scotinophara lurida)의 생활사와 기주식물)

  • 이기열;안기수;강효중;박성규;김태수
    • Korean journal of applied entomology
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    • v.40 no.4
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    • pp.309-313
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    • 2001
  • Life cycle and host plants of Scotinophara lurida(BURMEISTER) were studied from 1999 to 2001. Egg of S. lurida was oval-shaped with light-gray in color. Nymphs were reddish brown, dark brown, and brown, and the body was 1.19~7.24mm long, depending on their developmental stages from the 1st to the 5th instar. Adults were black and the body were 9.34mm and 8.47mm long in female laid 30.7 eggs in average for its life span. Developmental period was 4.3 days for eggs, and 45.8 days for nymphs. Total 9 host plant species was identified by the greenhouse observation in Chungbuk province.

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Issues of New Technological Trends in Nuclear Power Plant (NPPs) for Standardized Breakdown Structure

  • Gebremichael, Dagem D.;Lee, Yunsub;Jung, Youngsoo
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.353-358
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    • 2020
  • Recent efforts to develop a common standard for nuclear power plants (NPPs) with the aim of creating (1) a digital environment for a better understanding of NPPs life-cycle management aspect and (2) engineering data interoperability by using existing standards among different unspecified project participants (e.g., owners/operators, engineers, contractors, equipment suppliers) during plants' life cycle process (EPC, O&M, and decommissioning). In order to meet this goal, there is a need for formulating a standardized high-level physical breakdown structure (PBS) for NPPs project management office (PMO). However, high-level PBS must be comprehensive enough and able to represent the different types of plants and the new trends of technologies in the industry. This has triggered the need for addressing the issues of the recent operational NPPs and future technologies' ramification for evaluating the changes in the NPPs physical components in terms of structure, system, and component (SSC) configuration. In this context, this ongoing study examines the recent conventional NPPs and technological trends in the development of future NPPs facilities. New reactor models regarding the overlap of variant issues of nuclear technology were explored. Finally, issues on PBS for project management are explored by the examination of the configuration of NPPs primary system. The primary systems' configuration of different reactor models is assessed in order to clarify the need for analyzing the new trends in nuclear technology and to formulate a common high-level PBS. Findings and implications are discussed for further studies.

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