• Title/Summary/Keyword: natural science high school

Search Result 822, Processing Time 0.028 seconds

A Study on the Method for Ecological Restoration on Abandoned Concrete-paved Road - Focused on the Experimental Construction Site in Young Dong Province of GyungBu Express Highway(227.24~229.04km) - (콘크리트 폐도의 생태복원 방안 모색에 관한 연구 - 경부선 영동군 황간지역 시험시공지를 중심으로(경부고속도로 227.24~229.04km 지점) -)

  • Kim, Nam Choon;Ann, Phil Gun;No, Su Dae;Kim, Do Hee
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.15 no.4
    • /
    • pp.119-132
    • /
    • 2012
  • The unmanaged abandoned concrete roads are vulnerable toward the issues on soil and water pollution, which requires flexible managing method such as eco-corridor after the process of ecological restoration. Among various alternations of abandoned concrete-paved roads, ecological restoration technique may be the most suitable method in sites including high quality of natural environment. Therefore, as in Young dong province, GyungBu express highway (227.24~229.04km), which is near to Hwang-gan IC, the survey to measure its effect of soil under the paving and water pollution by abandoned concrete roads was discussed. Then, the restoration method of plantings of landscape trees and hydro-seeding methods of artificial soil media was appraised through consecutive monitoring. The soil adequacy analysis shows lower percentage of heavy metal substance in each depth level compared to standard limit stated by the Ministry of Environment, along with low concerns raised after the analysis on heavy metal content of the spilled water on the concrete roads. Meanwhile, Korean Weigela (Weigela subsessilis L.H. Baily) was found to be withered in small-scale landscape trees planting sites. Among the seeding plants. the family of leguminosae, Silene armeria, Dendranthema boreale, Caryopteris incana and Aster yomena show good establishment results. Overall studies on planting of small and large landscape trees, planting method of container plants, planting method of ground cover plants, and germination and development trend of seeding plants of the experimental restoration site on abandoned concrete roads are revealing specific trends in the way landscape woody plants establishment and growth. Finally, this study suggests further studies and survey on varied plant restoration methods on abandoned concrete-roads for developed design guidelines of their methods.

Feasibility of Optoelectronic Neural Stimulation Shown in Sciatic Nerve of Rats (흰쥐의 좌골 신경 자극을 통한 광전 자극의 가능성에 대한 연구)

  • Kim Eui tae;Oh Seung jae;Baac Hyoung won;Kim Sung june
    • Journal of Biomedical Engineering Research
    • /
    • v.25 no.6
    • /
    • pp.611-615
    • /
    • 2004
  • A neural prostheses can be designed to permit stimulation of specific sites in the nervous system to restore their functions, lost due to disease or trauma. This study focuses on the feasibility of optoelecronic stimulation into nervous system. Optoelectronic stimulation supplies, power and signal into the implanted optical detector inside the body by optics. It can be effective strategy especially on the retinal prosthesis, because it enables the non-invasive connection between the external source and internal detector through natural optical window 'eye'. Therefore, we designed an effective neural stimulating setup by optically based stimulation. Stimulating on the sciatic nerve of a rat with proper depth probe through optical stimulation needs higher ratio of current spreading through the neural surface, because of high impedance of neural interface. To increase the insertion current spreading into the neuron, we used a parallel low resistance compared to load resistance organic interface and calculated the optimized outer parallel resistance for maximum insertion current with the assumption of limited current by photodiode. Optimized outer parallel resistance was at a range of 500Ω-700Ω and a current was at a level between 580uA and 650uA. Stimulating current efficiency from initial photodiode induced current was between 47.5 and 59.7%. Various amplitude and frequency of the optical stimulation on the sciatic nerve showed the reliable visual tremble, and the action potential was also recorded near the stimulating area. These result demonstrate that optoelectronic stimulation with no bias can be applied to the retinal prosthesis and other neuroprosthetic area.

Influence of the application of Tithonia diversifolia and phosphate rocks on the performances of rainfed rice

  • Rusaati, Butoto Imani wa;Kang, Jun-Won;Gendusa, Patience Arusi;Bisimwa, Pacifique Bulakali;Kasali, Joseph Lumande;Rolly, Nkulu Kabange;Park, Joowon;Rehema, Esther Matendo;Ndabaga, Cephas Masumbuko;Kaboyi, Gentil Iragi;Nankafu, Orleanne Nangalire;Chirimwami, Anastasie Bahati
    • Korean Journal of Agricultural Science
    • /
    • v.47 no.3
    • /
    • pp.403-414
    • /
    • 2020
  • Gradient concentrations of Tithonia diversifolia green leaves and phosphate rocks were used to investigate their contributions as a fertilizer to the yield and quality improvement of a rainfed rice cultivar. Six treatments were compared: (1) T0, no fertilization (control); (2) T1, 1.28 g of phosphate rocks; (3) T2, 250 g of organic matter; (4) T3, 500 g of organic matter; (5) T4, 250 g of organic matter + 1.28 g of phosphate rocks; (6) T5, 500 g of organic matter + 1.28 g of phosphate rocks. The results showed that the germination percentage recorded 15 days after sowing varied from 58 - 76% between T0 and T5. The number of panicles ranged between 2 (T0) to 6.3 (T5). Moreover, the recorded length of the panicles ranged between 7.5 (T1) to 15.8 cm (T2), and the number of grains per panicle ranged between 25.5 (T1) to 273.5 (T3). The plant height was significantly increased in the T5 (79.27 cm) group compared to the T1 (33.63 cm) and control treatment (T0) (40.08 cm) groups. Although the plant height in the T2, T3, and T4 groups was slightly lower than the T5 group, the difference was not statistically significant. The average of the grain number per plant was high in the T3 (273.6 grains) group compared to the T1 and T0 (25.5 and 32.8 grains) groups, respectively. These results suggest that the combination of T. diversifolia leaves and phosphate rocks as a natural fertilizer would be beneficial when integrated into soil fertility management strategies and would contribute to improving crop yield and quality.

Effect of Seasoning Condition and Fruit Extracts Level on the Quality Characteristics of Venison Jerky (조미배합 조건과 과일농축물 첨가에 의한 노령 사슴육포의 품질특성)

  • Yang, Cheul-Young
    • The Korean Journal of Food And Nutrition
    • /
    • v.22 no.3
    • /
    • pp.345-351
    • /
    • 2009
  • The principal objectives of the experiments in this study were to assess the quality of venison jerky made from Elk deer (female, weight; 380 kg, age; 15 old years) in accordance with various seasoning sauce and mixture fruit extract level. Salinity, saccharinity and acidity values of the seasoning sauces were all high(VJ-1; 3.72%), (VJ-3; 3.95%), (VJ-1; 0.35%). The salinity range of the venison jerky products was 5.65~5.92%, the saccharinity range was 3.75~4.18%, and the seasoning sauce samples resulted in a significant difference in acidity values(p<0.05). Crude protein, fat and ash contents of the venison jerky products satisfied the Korean jerky standard value, but the moisture content range was 36.18~38.59%, and this was also in excess of the jerky standard level. The manufacturing yield was 42.24~44.48%, with VJ-1 at lowest levels followed by VJ-2 and VJ-3. The pH value of VJ-1 was high, but not significantly higher than the other samples(p>0.05). The water activity value range was measured at 0.68~0.71, and the lightness(L) and redness(a) value evidenced marked increases with increased amounts of added sodium nitrite(p<0.05), and the yellowness(b) values did not significantly differ(p>0.05). The overall sensory acceptance scores ranged between 5.53~7.49, in the order VJ-3, VJ-2, VJ-1(p<0.05).

Production of a Recombinant Laccase from Pichia pastoris and Biodegradation of Chlorpyrifos in a Laccase/Vanillin System

  • Xie, Huifang;Li, Qi;Wang, Minmin;Zhao, Linguo
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.6
    • /
    • pp.864-871
    • /
    • 2013
  • The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was $60^{\circ}C$, but it was not stable at high temperature. The enzyme could remain stable at $30^{\circ}C$ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system ($k_{obs}$ = 0.151) than that in the buffer solution ($k_{obs}$ = 0.028).

Spatial and Temporal Aspects of Phytoplankton Blooms in Complex Ecosystems Off the Korean Coast from Satellite Ocean Color Observations

  • Ahn, Yu-Hwan;Shanmugam, Palanisamy;Chang, Kyung-Il;Moon, Jeong-Eon;Ryu, Joo-Hyung
    • Ocean Science Journal
    • /
    • v.40 no.2
    • /
    • pp.67-78
    • /
    • 2005
  • Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and $54\;mg\;m^{-3}$ inside Jin-hae Bay and adjacent coastal bays and 0.5 and $8\;mg\;m^{-3}$ in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature $(\theta)$ and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water $(\theta and warm and high saline subsurface water $({\theta}>12^{\circ}C; S>34.4)$ at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.

The effect of changes in the difficulty level of concepts by semester and changes in class types on academic achievement by level

  • Min Ju Koo;Dong-Seon Shin;Jong Keun Park
    • International Journal of Advanced Culture Technology
    • /
    • v.11 no.3
    • /
    • pp.211-224
    • /
    • 2023
  • This study surveyed 2nd graders of B high school and 1st graders of A university in Gyeongnam on factors such as behavior control and interaction in non-face-to-face classes, easy or difficult concepts presented in chemistry I and general chemistry textbooks. Based on the results of the survey, the effect of changes in the difficulty level of concepts presented in chemistry I and general chemistry and changes in class types (face-to-face and non-face-to-face) on students' academic achievement by level was compared and analyzed. In the face-to-face class, the average score between the first and second semesters was similar according to the change in the difficulty of the concepts presented in chemistry I and general chemistry. In the non-face-to-face class, the average score of chemistry I in the second semester was quite low, and the average score of general chemistry was rather high. In non-face-to-face classes, the average score of chemistry I in the second semester of low-level students was significantly lowered due to changes in the difficulty of the concept and changes in class types on academic achievement by level. In the case of 10% of students at the lower level, the academic achievement of chemistry I decreased in both the second semester regardless of the changes in the difficulty level of concepts and the changes in class types.

Antioxidant activity and MMP-1 inhibitory activity of Panax Ginseng Sprout Extracts (새싹인삼 추출물의 항산화 활성 및 MMP-1 저해 활성 )

  • Min-Jung Kim;Ye-Jin Yang;Ju-Hye Yang;Won-Yung Lee;Woo-Hyun Kim;Jae-Nam Lee;Kwang-Il Park
    • Herbal Formula Science
    • /
    • v.32 no.1
    • /
    • pp.83-90
    • /
    • 2024
  • Objectives : As a substitute for high-price ginseng, this study attempted to examine a possibility of the ferment extract of Panax ginseng sprout whether leaves and roots can be used together as a cosmetic ingredient with anti-oxidative and wrinkle-care effects. Methods : In terms of a test method, antioxidant activities were confirmed through total polyphenol contents, total flavonoid contents, DPPH radical scavenging activity and ABTS radical scavenging activity using the Panax ginseng sprout. In addition, to assess wrinkle-care effectiveness, the cytotoxicity of the extract was analyzed through MTT assay, and inhibition of collagenase activity in the cells was tested using the Panax ginseng sprout fermented by Saccharomyces cerevisiae. Resuits : The content of polyphenols and flavonoids in natural plants was highest in Panax Ginseng Sprout Extract at 100℃, which also demonstrated high DPPH, ABTS radical scavenging activity. MTT assay demonstrated that the Panax Ginseng Sprout Ferment Extract did not have a cytotoxic effect in CCD-986SK cell. Also, Panax Ginseng Sprout Ferment Extract was found to inhibit MMP-1 expression by 51.85±6.09% at a concentration of 10%. Conclusions : Therefore, this study has confirmed a possibility of Panax ginseng sprout ferment extract as a cosmetic ingredient with MMP-1-inhibitory effects.

Effect of Whey Brew Cultured by Lactobacillus helveticus ATCC 55163 and Propionibacterium acidipropionici 5020 on Quality Characteristics of Bread (Lactobacillus helveticus ATCC 55163과 Propionibacterium acidipropionici 5020로 배양한 유청발효물이 빵의 품질특성에 미치는 영향)

  • Yun, Mi-Sug;Lee, Jeong-Hoon;Lee, Si-Kyung
    • Food Science of Animal Resources
    • /
    • v.30 no.3
    • /
    • pp.458-465
    • /
    • 2010
  • This study evaluated the effect of whey brew cultured by Lactobacillus helveticus ATCC 55163 and Propionibacterium acidipropionici 5020 on bread quality characteristics. Ten and 15% whey brew were added to flour-based bread, after which bread volume, pH, total titratable acidity (TTA), moisture content, water activity, texture, organic acid content, and sensory evaluation were analyzed. The bread volume and TTA of control were the largest among the samples, whereas pH was the lowest. Moisture content did not significantly differ depending on the amount of whey brew added, though water activity was highest in the bread with 10% whey brew. However, hardness was the lowest in bread with 10% whey brew. Propionic acid was not detected while succinic acid, lactic acid, and acetic acid were detected in small amounts in the control compared to the test samples. Succinic acid, acetic acid, and lactic acid content was high in bread with 15% whey brew, with propionic acid present at a very high amount. In terms of sensory evaluation, bread with 10% whey brew had the highest score. As a result, high quality characteristics were associated with the bread with 10% whey brew, whereas long preservation was a characteristic of the bread with 15% whey brew.

An Analysis of STS Contents in the High School Chemistry(II) Textbook (화학II 교과서의 STS 내용 분석)

  • Kim, Jung-Tae;Kim, Yun-Hi;Moon, Seong-Bae
    • Journal of the Korean Chemical Society
    • /
    • v.46 no.1
    • /
    • pp.90-96
    • /
    • 2002
  • The STS contents, emphasized in the 6th curriculum, in the chemistry textbooks(II) were analyzed. The STS contents in textbooks showed average value of 2.7%. The chapter of ‘chemical bond and compound' were included 3.8% of STS contents. And the chapter of ‘atomic structure and periodic table', ‘state of material and solution', ‘science of material', and ‘chemical reaction' contained 3.2%, 2.2%, 1.9%, and 1.9% of STS contents, respectively. When the STS contents were analyzed by STS topics of Piel, the results are as follows; 33.7% on effect of technological developments, 27.5% on environmental quality and utilization of natural source, 19.6% on human engineering, 13.8% on energy, and 5.4% on sociality of science. However, there were no topics on population, space research and national defense. When the STS contents were analyzed by student activities of SATIS, most of the activities were research and case study. There were few field activities of practical investigation, problem solving and decision making, research design and stimulation. There were no activities of role play.