• Title/Summary/Keyword: 사용이유

Search Result 3,482, Processing Time 0.034 seconds

A Study on the Forest Vegetation of Deogyusan National Park (덕유산 국립공원 삼림식생에 관한 연구)

  • Kim, Chang-Hwan;Oh, Jang-Geun;Lee, Nam-Sook
    • Korean Journal of Ecology and Environment
    • /
    • v.46 no.1
    • /
    • pp.33-40
    • /
    • 2013
  • From March 2012 to January 2013, this study was conducted as a part of the project for making a precise electronic ecological zoning map of vegetation on a highly reduced scale of 1 to 5,000 with a view to improving management efficiency of national parks and enlarging the availability of the data produced from the basic research monitoring the resources of national parks. For the research accuracy and rapidity, a vegetation map was specially created for the on-the-site-vegetation research. To make the map more meticulous, we categorized the vegetation database into five groups: broadleaved forest, coniferous forest, mixed forest, rock vegetation and miscellaneous one. After comparing the results of the data built for the vegetation research and the actual research findings, it was made clear that vegetation of both categories was almost the same in case of broad-leaved forest with 72.20% and 78.45% respectively, and also equivalent in other groups like, for example, coniferous forest (16.70%, 13.41%), mixed forest (9.50%, 7.49%) and rock vegetation (0.60%, 0.15%). According to the precise vegetation map produced from the research, the deciduous broad-leaved forest was the most widely prevalent type in the correlated hierarchical classification of vegetation, occupying 65.78% of the overall vegetation. It was followed by mountain valley forest (15.17%), coniferous forest (10.90%), and plantation forest (7.00%) in order. It is particularly noteworthy that Mt. Deogyusan national park has retained a very stable and versatile forest vegetation in the outstanding state since approximately 20% of the mountain turns out to belong to the I grade vegetation conservation classification which contains climax forests, unique vegetation, subalpine vegetation, matured stands which are older than 50 years and etc.

Numerical Study on Spring-Neap Variability of Net Volume Transport at Yeomha Channel in the Han River Estuary (한강하구 수로별 순 수송량과 대.소조기 변화에 따른 염하수로의 순 수송량 변동에 관한 수치해석적 연구)

  • Yoon, Byung-Il;Woo, Seung-Buhm
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.24 no.4
    • /
    • pp.257-268
    • /
    • 2012
  • The EFDC model with find grid resolution system connecting the Gyeong-Gi bay and Han River estuary was constructed to study on spring-neap variability of net volume transport at each channel of the Han River estuary. The simulation time of numerical model is 124 days from May to August, 2009 with freshwater discharge at Han, Imjin and Yeseong River. The calibration and verification of model results was confirmed using harmonic components of water level and tidal current. The net volume transport was calculated during 30 days with normal freshwater conditions at Seokmo channel and Yeomha channel around Ganghwado. The ebbing net volume transport of 44% and 56% is drained into Gyeong-Gi bay through Yeomha and Seokmo channel, respectively. The ebbing net volume transport nearby Seodo at Yeomha channel convergence flooding net volume transport at Incheon harbor, and drain (westward direction) through channel of tidal flat between Ganghwado and Yeongjongdo to the Gyeong-Gi bay. The averaged net volume transport during 4 tidal cycles was compared to variation of spring-neap periods of the Yeomha channel. The convergence position is moved up- and down-ward according to spring-neap variability. The movement of the convergence zone is appeared because 1) increasing of discharged rate tidal flat channel between Ganghwado and Yeongjongdo at the spring period, 2) The growth of barotropic forcing with downward direction at the spring tide, and 3) The strength of the baroclinic pressure gradient is greater than spring with mixing processes.

Simulation and model validation of Biomass Fast Pyrolysis in a fluidized bed reactor using CFD (전산유체역학(CFD)을 이용한 유동층반응기 내부의 목질계 바이오매스 급속 열분해 모델 비교 및 검증)

  • Ju, Young Min;Euh, Seung Hee;Oh, Kwang cheol;Lee, Kang Yol;Lee, Beom Goo;Kim, Dae Hyun
    • Journal of Energy Engineering
    • /
    • v.24 no.4
    • /
    • pp.200-210
    • /
    • 2015
  • The modeling for fast pyrolysis of biomass in fluidized bed reactor has been developed for accurate prediction of bio-oil and gas products and for yield improvement. The purpose of this study is to analyze and to compare the CFD(Computational Fluid Dynamics) simulation results with the experimental data from the CFD simulation results with the experimental data from the reference(Mellin et al., 2014) for gas products generated during fast pyrolysis of biomass in fluidized bed reactor. CFD(ANSYS FLUENT v.15.0) was used for the simulation. Complex pyrolysis reaction scheme of biomass subcomponents was applied for the simulation of pyrolysis reaction. This pyrolysis reaction scheme was included reaction of cellulose, hemicellulose, lignin in detail, gas products obtained from pyrolysis were mainly $CO_2$, CO, $CH_4$, $H_2$, $C_2H_4$. The deviation between the simulation results from this study and experimental data from the reference was calculated about 3.7%p, 4.6%p, 3.9%p for $CH_4$, $H_2$, $C_2H_4$ respectively, whereas 9.6%p and 6.7%p for $CO_2$ and CO which are relatively high. Through this study, it is possible to predict gas products accurately by using CFD simulation approach. Moreover, this modeling approach should be developed to predict fluidized bed reactor performance and other gas product yields.

Evaluation of Agronomic Characteristics, Nutritional Contents, and Insect Response of the Transgenic Potato Resistant to Glufosinate Ammonium (제초제 저항성 형질전환 감자의 농업적 특성, 영양 성분 및 해충 반응성 평가)

  • Ahn, Soon-Young;Cho, Kwang-Soo;Seo, Hyeo-Won;Yi, Jeong-Yoon;Bae, Shin-Cheol;Cho, Ji-Hong;Park, Young-Eun;Kim, Ju-Il;Kim, Hyun-Jun;Cho, Hyun-Mook
    • Horticultural Science & Technology
    • /
    • v.29 no.3
    • /
    • pp.247-254
    • /
    • 2011
  • The agronomic characteristics, nutritional contents, and insect response of the potato clones transformed with a glufosinate ammonium resistance gene were evaluated. Among the 4 transgenic potato clones, the Bar 3 clone was selected as a promising one for commercialization. The Bar 3 clone showed similar tuber yield capacity but higher herbicide resistance as compared with the non-transgenic potato cv. Dejima. The herbicide resistance of the Bar 3 clone was more than 5 times higher when tested with the herbicide concentration recommended by the producer. The major agronomic characteristics of the Bar 3 clone were not different from those of the non-transgenic Dejima. The annual variation in yields and agronomic characteristics showed similar tendency for 2 years from the third to fourth generation after transformation. The tubers of the Bar 3 clone also showed low occurrence in common scab and physiological disorders such as cracking and secondary growth. But the reasons for such results are yet to be studied. Also, it was considered that the Bar 3 clone have a potential of reducing not only common scab occurrence but also soil erosion during potato cultivation in field. The nutritional contents (mineral compound, vitamin C and amino acid) and response to Spodoptera exigua of the transgenic potato clones were not significantly different.

Optimization for Underwater Welding of Marine Steel Plates (선박용 강판의 수중 용접 최적화에 관한 연구)

  • 오세규
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.20 no.1
    • /
    • pp.49-59
    • /
    • 1984
  • Optimizing investigation of characteristics of underwater welding by a gravity type arc welding process was experimentally carried out by using six types of domestic coated welding electrodes for welding of domestic marine structural steel plates (KR Grade A-1, SWS41A, SWS41B,) in order to develop the underwater welding techniques in practical use. Main results obtained are summarized as follows: 1. The absorption speed of the coating of domestic coated lime titania type welding-electrode became constant at about 60 minutes in water and it was about 0.18%/min during initial 8 minutes of absorption time. 2. Thus, the immediate welding electrode could be used in underwater welding for such a short time in comparison with the joint strength of in-atmosphere-and on-water-welding by dry-, wet-or immediate-welding-electrode. 3. By bead appearance and X-ray inspection, ilmenite, limetitania and high titanium oxide types of electrodes were found better for underwater-welding of 10 mm KR Grade A-1 steel plates, while proper welding angle, current and electrode diameter were 6$0^{\circ}C$, above 160A and 4mm respectively under 28cm/min of welding speed. 4. The weld metal tensile strength or proof stress of underwater-welded-joints has a quadratic relationship with the heat input, and the optimal heat input zone is about 13 to 15KJ/cm for 10mm SWS41A steel plates, resulting from consideration upon both joint efficiency of above-100% and recovery of impact strength and strain. Meanwhile, the optimal heat input zone resulting from tension-tension fatigue limit above the base metal's of SWS41A plates is 16 to 19KJ/cm. Reliability of all the empirical equations reveals 95% confidence level. 6. The microstructure of the underwater welds of SES41A welded in such a zone has no weld defects such as hydrogen brittleness with supreme high hardness, since the HAZ-bond boundary area adjacent to both surface and base metal has only Hv400 max with the microstructure of fine martensite, bainite, pearlite and small amount of ferrite.

  • PDF

Current Status and Prospects of Various Methods used for Screening Probiotic Microorganisms (Probiotic 미생물 검사에 사용되는 다양한 방법들에 대한 현황과 향후 전망)

  • Kim, Dong-Hyeon;Kim, Hong-Seok;Jeong, Dana;Chon, Jung-Whan;Kim, Hyunsook;Kim, Young-Ji;Kang, Il-Byung;Lee, Soo-Kyung;Song, Kwang-Young;Park, Jin-Hyeong;Chang, Ho-Seok;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
    • /
    • v.34 no.4
    • /
    • pp.203-216
    • /
    • 2016
  • Probiotic microorganisms are thought to provide health benefits when consumed. In 2001, the World Health Organization defined probiotics as "live microorganisms which confer a health benefit on the host, when administered in adequate amounts." Three methods for screening potential probiotics have currently widely available. (1) In vitro assays of potential probiotics are preferred because of their simplicity and low cost. (2) The use of in vivo approaches for exploring various potential probiotics reflects the enormous diversity in biological models with various complex mechanisms. (3) Potential probiotics have been analyzed using several genetic and omics technologies to identify gene expression or protein production patterns under various conditions. However, there is no ideal procedure for selecting potential probiotics than testing cadidate strains on the target population. Hence, in this review, we provide an overview of the different methodologies used to identify new probiotic strains. Furthermore, we describe futre perspectives for the use of in vitro, in vivo and omics in probiotic research.

Effects of Arsenite and Antioxidants on Sperm Motility, Plasma Membrane Integrity, Mitochondrial Activity, and Lipid Peroxidation in Pigs (돼지정자의 운동성, 원형질막 온전성, 미토콘드리아 기능성 및 원형질막 지질과산화에 미치는 arsenite 및 항산화제의 영향)

  • Kim, Han-Su;Lee, Yu-Sub;Lee, Sang-Hee;Cheong, Hee-Tae;Park, Choon-Keun;Lee, Seunghyung;Yang, Boo-Keun
    • Journal of Life Science
    • /
    • v.27 no.5
    • /
    • pp.517-523
    • /
    • 2017
  • This study was to investigate the role of antioxidants on the characteristics of arsenite-damaged boar semen. Collected sperm was diluted with semen extender, and $100{\mu}M$ arsenite was used for sperm damage. Then melatonin, silymarin, curcumin, and vitamin E were applied for 3, 6, and 9 hr in arsenite-treated boar sperm. Sperm characteristics were then analyzed for motility, plasma membrane integrity, mitochondrial activity, and lipid peroxidation. In the results, sperm motility (control, $77.3{\pm}1.8%$) was decreased by arsenite ($33.3{\pm}1.5%$), while the antioxidant treatment groups (100 nM melatonin, $55.8{\pm}3.4%$; $2{\mu}M$ silymarin, $48.8{pm}3.4%$; $10{\mu}M$ curcumin, $53.9{\pm}2.8%$; and $500{\mu}M$ vitamin E, $54.5{\pm}3.1%$) showed increases compared to the arsenite group (p<0.05). $100{\mu}M$ arsenite decreased the sperm plasma membrane integrity ($24.5{\pm}1.6%$) and mitochondrial activity ($58.2{\pm}2.6%$), and increased lipid peroxidation ($5.3{\pm}0.2%$) at 3 hr (p<0.05). However, arsenite-treated samples with 100 nM melatonin, $2{\mu}M$ silymarin, $10{\mu}M$ curcumin, and $500{\mu}M$ vitamin E increased the plasma membrane integrity and mitochondria activity, and decreased lipid peroxidation compared to the arsenite-treated samples. In summary, arsenite may induce sperm damage and oxidation stress, while antioxidants such as melatonin, silymarin, curcumin, and vitamin E are useful for maintaining sperm characteristics. Therefore, antioxidants can protect sperm against damage by arsenite in fresh boar semen.

Combination Culture of Rotifer Brachionus rotundiformis and Copepod Apocylops sp. (로티퍼 Brachionus rotundiformis와 코페포다 Apocyclops sp.의 혼합 배양)

  • Jung, Min-Min;Rho, Sum
    • Journal of Aquaculture
    • /
    • v.11 no.4
    • /
    • pp.449-455
    • /
    • 1998
  • The small size food organism(under the size 150${\mu}m$) is needed as food for early stage of marine fish larvae of small mouse (e.g the group of grouper). This study was investigated to develop a method for copepod Apocyclops sp. culture in combination with the rotifer B. rachionus for stable culture of copepod species and harvest of various size food organisms. The culture conditions as temperature, salinity, culture volume, photo period, culture preiod and observation interval were 25${\circ}C$, 22ppt, 40ml, all dark except to observation time, 16 days and every two day during the experimental period, respectively. The Tetraselmis suecica was used as the food for the two testing orgtanisms. After every two day counting, theses two organisms were transferred to fresh culture tanks with Tetraselmis suecica of $7{\times}10^5$cells/ml. In the mixed culture of B. rotundiformis and A. sp., growth of rotifer was suppressed by mixed culture with A. sp. whereas the growth of copepod Apocyclops was promoted in the mixed culture with rotifer B. rotundiformis (the maximum density was 22 individuals/ml through the 16 culture days). Moreover, the number of copepod nauplius were promoted about 2 times in the mixed culture compared to the numbers in single species culture. With this combination culture, the havested two food organisms of variable sizes. This size variation of food organisms was useful tools for larval rearing of small mouse marine fish larvae and next step food organism size of post hatched larvae.

  • PDF

Sensory Integration and Occupational Therapy for Elementary Students Collaborative Group Program : Implementing School AMPS (초등학생집단 다전문가 협업프로그램에서의 School AMPS 분석을 통한 작업치료와 감각통합접근의 의미)

  • Ji, Seok-Yeon;Lee, Seong-A;Park, So-Yeon;Hong, Min-Kyung
    • The Journal of Korean Academy of Sensory Integration
    • /
    • v.11 no.1
    • /
    • pp.11-27
    • /
    • 2013
  • Objective : This is a descriptive study using a program review collaborative group program by special educator and occupational therapist for supporting children's school tasks, and it is designed to explore how changed school performance skills and to analyze how applied intervention methods including sensory integrative approach. Methods : Participants were 6 male elementary students(5 = 1st grade, 1 = 2nd grade). Pilot program had reviewed and its results used as base for planning main program. Main program was implemented by collaborative process with teacher and occupational therapist for 1 year. School AMPS was used to assess school task participants, and informal motor and process skill observation was used to assess self-help activities. Description of records by professions about intervention strategies through assessments was described as qualitative way. Japanese sensory inventory was used by parents. Results : Through the collaborative process, assessing children, planning and modifying program, establishing intervention strategies were implemented. Self-help abilities in group program were increased much more independently. School task abilities were increased slightly but skills changed irregularly and unexpectedly and their reasons became considered more complex from sensory processing reasons to social and emotional reasons. Conclusion : Sensory integration had benefits for primary group program and more complex intervention strategies became to emerge demands for person- environment-task challenges. Collaborative practice with teacher and occupational therapist was supplement and synergic effect for children and group dynamics. More objective and comprehensive methods for measure collaboration and group effect would be needed in further study.

  • PDF

The Effectiveness of Spiral Computed Tomography as a Diagnostic Tool in Pulmonary Embolism(Comparison of Spiral CT with Ventilation-Perfusion Scan) (폐색전증 진단의 도구로서의 Spiral Computed Tomography의 유용성(폐환기관류주사와의 비교))

  • Koh, Jae-Hyun;Oh, Eun-Young;Park, Jung-Ho;Park, Sang-Joon;Yun, Jung-Hwan;Park, Jung-Woong;Suh, Gee-Young;Chung, Man-Pyo;Lee, Kyung-Soo;Kwon, O-Jung;Rhee, Chong-H.
    • Tuberculosis and Respiratory Diseases
    • /
    • v.46 no.4
    • /
    • pp.564-573
    • /
    • 1999
  • Background: With variable symptoms and nonspecific radiographic appearances, pulmonary embolism (PE) is a frequent and often undiagnosed cause of mortality and morbidity. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study suggested that the majority of patients undergoing ventilation-perfusion (V-Q) scan would require additional studies to establish or to exclude the diagnosis of PE. Pulmonary angiography has been regarded as gold standard for diagnosis of PE. However, it is an invasive procedure that may be associated with significant notable morbidity and mortality. Thus, availability of an accurate, noninvasive screening examination is highly desirable. Method: From October 1994 to February 1997, twenty patients (male 13, female 7, range 23-91 years, median 58 years) who were suspected as pulmonary embolism on the basis of clinical evidence and underwent the spiral volumetric computed tomography (spiral CT), were studied retrospectively to evaluate the effectiveness of spiral CT as a diagnostic tool in PE. Results: PE could be excluded with spiral CT in 4 patients ; diagnoses of these patients were lung cancer, pneumonia with lung abscess, bilateral pleural effusion due to congestive heart failure, nonspecific pulmonary abnormality retrospectively. One patient who disclosed high probability in V/Q scan, could be diagnosed as pneumonia with lung abscess and underlying emphysema with spiral CT. Among 4 patients who showed intermediate and low probability in V/Q scan, 3 patients could be confirmed as PE with spiral CT. Spiral CT was helpful in 3 patients, in whom V/Q scan could not be performed due to other reasons (e.g. night time, mechanical ventilation) to confirm the diagnosis of PE. Spiral CT could demonstrate embolus above lobar artery level in 11 patients, and up to segmental artery level in 5 patients. Conclusion: This study demonstrated that spiral CT could allow accurate demonstration of thrombotic clots in centrally localized embolism. Spiral CT could be effective, specific, noninvasive and useful diagnostic screening modality for the diagnosis of pulmonary embolism.

  • PDF