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Analysis of Suspended Solids Reduction by Vegetative Filter Strip for Cultivated Area Using Web GIS-Based VFSMOD (VFSMOD를 이용한 경작지의 고형물질 유출 저감효과)

  • Ahn, Jae Hwan;Yun, Sang Leen;Kim, Seog Ku;Park, Youn Shik;Lim, Kyoung Jae
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.12
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    • pp.792-800
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    • 2012
  • The study was performed to simulate the reduction efficiency of suspended solids (SS) for cultivated land located at riverine area at the Namhan River and the Bukhan River watershed sites (site A, B, C) under the rainfall conditions using HUFF & SCS UH-based VFS Design module of Web GIS-based VFSMOD System. The study indicates that the field 5% sloped, located at Bukhan River watershed (site A), requires at least 0.5 m width of Vegetative Filter Strip (VFS) to reduce 70% of SS while the field 10% sloped requires the at least 1.0~1.5 m width of VFS to reduce 70% SS, under the condition 106.2 mm of rainfall event and bell pepper or corn of crops. Against the conditions 95.1 mm of rainfall event and sweet potato or soy bean of crops, the field 5% sloped, located at Namhan River watershed (site B) requires at least 0.5 m width of VFS to reduce 70% of SS while the field 10% sloped requires at least 1.0 m width of VFS to reduce 50% SS. The crops sweet potato and soy bean are cultivated in the site C, located at Namhan River watershed, 1 m of VFS is capable of 64.0% and 62.0% of SS reduction against 102.6 mm and 151.2 mm rainfall conditions respectively, for the 5% sloped field. The result supports that VFS is one of most potential methods to reduce SS from cultivated area, which is environment-friendly hydrologic structure. The VFS design, however, needs to be simulated before its installation in the field, the simulation needs to consider not only various characteristics of the field but also different conditions affecting the VFS, using a model capable to consider a lot of factors.

Optimum Condition of Soil Dispersion for Remediating Heavy Metal-Contaminated Soils using Wet Magnetic Separation (중금속 오염 토양 정화를 위한 습식자력선별법 사용 시 최적 토양분산 조건)

  • Chon, Chul-Min;Park, Jeong-Sik;Park, Sook-Hyun;Kim, Jae-Gon;Nam, In-Hyun
    • Economic and Environmental Geology
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    • v.45 no.2
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    • pp.121-135
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    • 2012
  • Soil dispersion and heavy metal leaching with two heavy metal-contaminated soils were studied to derive the optimal dispersion condition in the course of developing the remedial technology using magnetic separation. The dispersion solutions of pyrophosphate, hexametaphosphate, orthophosphate and sodium dodecylsulfate (SDS) at 1 - 200 mM and the pH of solutions was adjusted to be 9 - 12 with NaOH. The clay content of suspension as an indicator of dispersion rate and the heavy metal concentration of the solution were tested at the different pHs and concentrations of the dispersion solution during the experiment. The dispersion rate increased with increasing the pH and dispersion agent concentration of the solution. The dispersion efficiency of the agents showed as follows: pyrophosphate > hexametaphosphate > SDS > orthophosphate. Arsenic leaching was sharply increased at 50 mM of phosphates and 100 mM of SDS. The adsorption of $OH^-$, phosphates and dodecysulfate on the surface of Fe- and Mn-oxides and soil organic matter and the broken edge of clay mineral might decrease the surface charge and might increase the repulsion force among soil particles. The competition between arsenic and $OH^-$, phosphates and dodecylsulfate for the adsorption site of soil particles might induce the arsenic leaching. The dispersion and heavy metal leaching data indicate that pH 11 and 10 mM pyrophosphate is the optimum dispersion solution for maximizing dispersion and minimizing heavy metal leaching.

Biogeochemical Remediation of Cr(VI)-Contaminated Groundwater using MMPH-0 (Enterobacter aerogenes) (MMPH-0 (Enterobacter aerogenes)에 의한 6가 크롬 오염 지하수의 생지화학적 정화)

  • Seo, Hyun-Hee;Rhee, Sung-Keun;Kim, Kang-Joo;Park, Eun-Gyu;Kim, Yeong-Kyoo;Chon, Chul-Min;Moon, Ji-Won;Roh, Yul
    • Economic and Environmental Geology
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    • v.45 no.2
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    • pp.105-119
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    • 2012
  • Indigenous bacteria isolated from contaminated sites play important roles to remediate contaminated groundwater. Chromium has the most stable oxidation states. Cr(VI) is toxic, carcinogenic, and mobile, but Cr(III) is less toxic and immobile. In this study, indigenous microorganism (MMPH-0) was enriched from Cr(VI) contaminated groundwater, and identified by 16S rRNA gene analysis. Using MMPH-0, the effect of stimulating with e-donors (glucose, lactate, acetate, and no e-donor control), respiration conditions, biomass, tolerance, and geochemical changes on Cr(VI) reduction were investigated in batch experiments for 4 weeks. The changes of Cr(VI) concentration and geochemical conditions were monitored using UV-vis-spectrophotometer and Eh-pH meter. And the morphological and chemical characteristics of MMPH-0 and precipitates in the effluents were characterized by TEM-EDS and SEM-EDS analyses. MMPH-0 (Enterobacter aerogenes) was able to tolerate up to 2000 mg/L Cr(VI) and reduce Cr(VI) under aerobic and anaerobic conditions. MMPH-0 performed faster and higher efficiency of Cr(VI) reduction with electron donors (over 70% after 1 week with e-donor, 10-20% after 4 weeks without e-donor). The changes of Eh-pH in effluents showing the tendency from oxidizing to reducing condition and a bit of acidic change in pH due to microbial oxidation of organic matters donating electrons and protons suggested the roles of MMPH-0 on Cr(VI) in the contaminated water catalyzing to transit geochemical stable zone for more stable $Cr(OH)_3$ or Cr(III) precipitates. TEM/SEM-EDS analyses of MMPH-0 and precipitates indicate direct and indirect Cr(VI) reduction: extracellular polymers capturing Cr component outside cells. These results suggested diverse indigenous bacteria and their biogeochemical reactions might enhance more effective and feasible remediation technology of redox sensitive heavy metals in metal-contaminated in groundwater.

Physico-chemical effects of cerium oxide on catalytic activity of CeO2-TiO2 prepared by sol-gel method for NH3-SCR (CeO2가 졸겔법으로 합성한 CeO2-TiO2계 SCR용 촉매의 활성에 미치는 물리화학적 영향)

  • Kim, Buyoung;Shin, Byeongkil;Lee, Heesoo;Chun, Ho Hwan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.6
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    • pp.320-324
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    • 2013
  • The effects of $CeO_2$ on catalytic activity of $CeO_2-TiO_2$ for the selective catalytic reduction (SCR) of $NO_x$ were investigated in terms of structural, morphological, and physico-chemical analyseis. $CeO_2-TiO_2$ catalysts were synthesized with three different additions, 10, 20, and 30 wt% of $CeO_2$, by the sol-gel method. The XRD peaks of all specimens were assigned to a $TiO_2$ phase (anatase) and the peaks became broader with the addition of $CeO_2$ because it was dispersed as an amorphous phase on the surface of $TiO_2$ particles. The specific surface area of $TiO_2$ increased with the addition of $CeO_2$ from $60.6306m^2/g$ to $116.2791m^2/g$ due to suppression of $TiO_2$ grain growth by $CeO_2$. The 30 wt% $CeO_2-TiO_2$ catalyst, having the strongest catalytic acid sites ($Br{\Phi}nsted$ and Lewis), showed the highest $NO_x$ conversion efficiency of 98 % at $300^{\circ}C$ among the specimens. It was considered that $CeO_2$ contributes to the improvement of the $NO_x$ conversion of $CeO_2-TiO_2$ catalyst by increasing specific surface area and catalytic acid sites.

Plant regeneration and transformation of grape (Vitis labrusca L.) via direct regeneration method (포도 (Vitis labrusca L.)의 직접 재분화 방법을 이용한 식물체 재분화와 형질전환)

  • Kim, Se Hee;Shin, Il Sheob;Cho, Kang Hee;Kim, Dae Hyun;Kim, Hyun Ran;Kim, Jeong Hee;Lim, Sun-Hyung;Kim, Ki Ok;Lee, Hyang Bun;Do, Kyung Ran;Hwang, Hae Seong
    • Journal of Plant Biotechnology
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    • v.40 no.4
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    • pp.210-216
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    • 2013
  • Efficient regeneration methods and transformation system are a priority for successful application of genetic engineering to vegetative propagated plants such as grape (Vitis labrusca L.). This research is to establish shoot regeneration system from plant explants for 'Campbell Early', 'Tamnara', 'Heukgoosul', 'Heukbosek' using two types of plant growth regulators supplemented to medium. The highest adventitious shoot regeneration rate of 5% was achieved on a medium containing of Murashige and Skoog (MS) inorganic salts and Linsmaier and Skoog (LS) vitamins, 2 mg/L of TDZ and 0.1 mg/L of IBA. Leaf tissue of 'Campbell Early', was co-cultivated with Agrobacterium strains, LBA4404 containing the vector pBI121 carrying with CaMV 35S promoter, gus gene as reporter gene and resistance to kanamycin as selective agent, the other Agrobacterium strains, GV3101 containing the vector pB7 WG2D carrying with mPAP1-D gene. mPAP1-D is a regulatory genes of the anthocyanin biosynthetic pathway. 'Campbell Early' harboring mPAP1-D gene was readily able to be selected by red color due to anthocyanin accumulation in the transformed shoot. These results might be helpful for further studies to enhance the transformation efficiency in grape.

Assessment of Climate Change Impact on Storage Behavior of Chungju and the Regulation Dams Using SWAT Model (SWAT을 이용한 기후변화가 충주댐 및 조정지댐 저수량에 미치는 영향 평가)

  • Jeong, Hyeon Gyo;Kim, Seong-Joon;Ha, Rim
    • Journal of Korea Water Resources Association
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    • v.46 no.12
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    • pp.1235-1247
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    • 2013
  • This study is to evaluate the climate change impact on future storage behavior of Chungju dam($2,750{\times}10^6m^3$) and the regulation dam($30{\times}10^6m^3$) using SWAT(Soil Water Assessment Tool) model. Using 9 years data (2002~2010), the SWAT was calibrated and validated for streamflow at three locations with 0.73 average Nash-Sutcliffe model Efficiency (NSE) and for two reservoir water levels with 0.86 NSE respectively. For future evaluation, the HadCM3 of GCMs (General Circulation Models) data by scenarios of SRES (Special Report on Emission Scenarios) A2 and B1 of the IPCC (Intergovernmental Panel on Climate Change) were adopted. The monthly temperature and precipitation data (2007~2099) were spatially corrected using 30 years (1977~2006, baseline period) of ground measured data through bias-correction, and temporally downscaled by Change Factor (CF) statistical method. For two periods; 2040s (2031~2050), 2080s (2071~2099), the future annual temperature were predicted to change $+0.9^{\circ}C$ in 2040s and $+4.0^{\circ}C$ in 2080s, and annual precipitation increased 9.6% in 2040s and 20.7% in 2080s respectively. The future watershed evapotranspiration increased up to 15.3% and the soil moisture decreased maximum 2.8% compared to baseline (2002~2010) condition. Under the future dam release condition of 9 years average (2002~2010) for each dam, the yearly dam inflow increased maximum 21.1% for most period except autumn. By the decrease of dam inflow in future autumn, the future dam storage could not recover to the full water level at the end of the year by the present dam release pattern. For the future flood and drought years, the temporal variation of dam storage became more unstable as it needs careful downward and upward management of dam storage respectively. Thus it is necessary to adjust the dam release pattern for climate change adaptation.

Fusaric Acid Production in Fusarium oxysporum Transformants Generated by Restriction Enzyme-Mediated Integration Procedure (Restriction Enzyme-Mediated Integration 방법으로 확보한 Fusarium oxysporum 형질전환체의 후자리산 생성능 분석)

  • Lee, Theresa;Shin, Jean Young;Son, Seung Wan;Lee, Soohyung;Ryu, Jae-Gee
    • Research in Plant Disease
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    • v.19 no.4
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    • pp.254-258
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    • 2013
  • Fusaric acid (FA) is a mycotoxin produced by Fusarium species. Its toxicity is relatively low but often associated with other mycotoxins, thus enhancing total toxicity. To date, biosynthetic genes or enzymes for FA have not been identified in F. oxysporum. In order to explore the genetic element(s) for FA biosynthesis, restriction enzyme mediated integration (REMI) procedure as an insertional mutagenesis was employed using FA producing-F. oxysporum strains. Genetic transformation of two F. oxysporum strains by REMI yielded more than 7,100 transformants with efficiency of average 3.2 transformants/${\mu}g$ DNA. To develop a screening system using phytotoxicity of FA, eleven various grains and vegetable seeds were tested for germination in cultures containing FA: Kimchi cabbage seed was selected as the most sensitive host. Screening for FA non-producer of F. oxysporum was done by growing each fungal REMI transformant in Czapek-Dox broth for 3 weeks at $25^{\circ}C$ then observing if the Kimchi cabbage seeds germinated in the culture filtrate. Of more than 5,000 REMI transformants screened, fifty-three made the seeds germinated, indicating that they produced little or fewer FA. Among them, twenty-six were analyzed for FA production by HPLC and two turned out to produce less than 1% of FA produced by a wild type strain. Sequencing of genomic DNA regions (252 bp) flanking the vector insertion site revealed an uncharacterized genomic region homologous (93%) to the F. fujikuroi genome. Further study is necessary to determine if the vector insertion sites in FA-deficient mutants are associated with FA production.

Effects of PAA (Polyaspartic Acid) Contained Complex Fertilizer on Rice Growth and CH4 emission from Rice Cultivation (PAA(Polyaspartic Acid) 함유 복합비료가 벼 생육 및 벼 재배 논에서의 메탄 발생에 미치는 영향 연구)

  • Ju, Okjung;Lee, Jeong-Hyung;Choi, Byoung-Rourl;Won, Tae-Jin;Cho, Kwang-Rae;Seo, Jae-Sun;Kim, Young-Sun;Park, In-Tae
    • Journal of Environmental Impact Assessment
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    • v.22 no.6
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    • pp.705-711
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    • 2013
  • This study was carried out to investigate the effects of the complex fertilizers containing polyaspartic acid (PAA) on growth and $CH_4$ emission in rice field and optimum application rate of the fertilizer compared to the standard recommended application rate (control). The PAA-containing complex fertilizers (PCF) were applied at 55, 65 and 75% levels of standard recommended application rate (control). The application rate of PAA in the plot of every PCF treatment was 150g ai/10a. The PCF was applied as a basal dressing without topdressing at tillering stage. The growth parameters of rice and its nitrogen use efficiency treated with PCF at a 65 to 75% level were not different compared with those of control, and the rice yield was also not significantly different between PCF at a 65 to 75% level and control during 2 years(2010~2011) field experiment. And the $NH_4$-N content in soil was not affected by 65% to 75% level of PCF treatment. Considering overall research results such as rice yield and growth parameters PCF is not significantly different with the control and the optimum application rate of the PCF as a basal fertilization was determined to be 65~75% of the standard application rate based on the result in rice cultivation. Moreover, $CH_4$ emission rate was significantly reduced by PCF treatments, showing 216 kg and 229 kg $CH_4/ha$ at 65% and 75% PCF treatment level, respectively, compared to 266 kg $CH_4/ha$ of the control.

A Case Study on Implementation of Mobile Information Security (모바일 정보보안을 위한 실시간 모바일 기기 제어 및 관리 시스템 설계.구현 사례연구)

  • Kang, Yong-Sik;Kwon, Sun-Dong;Lee, Kang-Hyun
    • Information Systems Review
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    • v.15 no.2
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    • pp.1-19
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    • 2013
  • Smart working sparked by iPhone3 opens a revolution in smart ways of working at any time, regardless of location and environment. Also, It provide real-time information processing and analysis, rapid decision-making and the productivity of businesses, including through the timely response and the opportunity to increase the efficiency. As a result, every company are developing mobile information systems. But company data is accessed from the outside, it has problems to solve like security, hacking and information leakage. Also, Mobile devices such as smart phones belonging to the privately-owned asset can't be always controlled to archive company security policy. In the meantime, public smart phones owned by company was always applied security policy. But it can't not apply to privately-owned smart phones. Thus, this paper is focused to archive company security policy, but also enable the individual's free to use of smart phones when we use mobile information systems. So, when we use smart phone as individual purpose, the normal operation of all smart phone functions. But, when we use smart phone as company purpose like mobile information systems, the smart phone functions are blocked like screen capture, Wi-Fi, camera to protect company data. In this study, we suggest the design and implementation of real time control and management of mobile device using MDM(Mobile Device Management) solution. As a result, we can archive company security policy and individual using of smart phone and it is the optimal solution in the BYOD(Bring Your Own Device) era.

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The Study on the College Students' Career Reasons Affecting on Self-efficacy and Entrepreneurial Intention (대학생의 직업선택 동기가 창업에 대한 자아효능감과 창업의지에 미치는 영향에 대한 연구)

  • Lee, Woo Jin
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.8 no.3
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    • pp.113-124
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    • 2013
  • The government strives to create venture ecosystem for realizing creative economy, at the same time, the Mistry of Education is spending huge resources and efforts to spread entrepreneurship education to universities in Korea. Since entrepreneurship education gives motivation to individuals and creates market innovation and these connect to the growth of national economy through increased efficiency, entrepreneurship education is becoming increasingly more important for realizing creative economy. Based on the importance, entrepreneurship education in the universities is now spreading rapidly. However, college students' entrepreneurial intention has still not been improved comparing to spreading entrepreneurship education. To overcome the poor improvement, entrepreneurship education needs to be driven more systematic direction through the study on the effect of students' motivation and environment. In this study, entrepreneurship as a part of careers perspectives, is analyzed on students' career reasons with entrepreneurial intention. For this study, 918 surveys was collected from 7 universities having entrepreneurship courses in Seoul and Gyeonggi regions in 2012 and analyzed 858 surveys in order to prove the hypothesis. The results disclosed the relationship between students' career reasons and entrepreneurial self-efficacy and intention. Motivation factors of self-realization, innovation and role model have positive effect on entrepreneurial self-efficacy following by increased entrepreneurial intention, unlike the common notion financial success and independence factors are not significant with entrepreneurial intention of students. Based on these results having meaningful implication to Korea entrepreneurship education, this study is expected to have contribution to the successful promoting the creative economy realization of our government.

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