• Title/Summary/Keyword: Limiting Efficiency

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Bioremediation of Petroleum Contaminated Soils by Pilot Scale Biopile (Pilot 규모 biopile에 의한 유류오염토양의 정화)

  • Yoon, Jeong Ki;Noh, Hoe-Jung;Kim, Hyuk;Kim, Jong Ha;Kim, Tae Seung;Ko, Sung Hwan
    • Journal of Soil and Groundwater Environment
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    • v.18 no.2
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    • pp.10-18
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    • 2013
  • The pilot scale biopile system was designed and operated for evaluation of bioremediation efficiency for petroleum contaminated soil. The pilot scale biopile consisted of biopile dome, aeration system and monitoring system and two biopiles were operated with nutrients and inoculum for more 100 days. The test pile A and B were analyzed with regard to pH, total carbon contents, water contents, nutrients (N, P) and TPH. The initial TPH concentrations for pile A and pile B were about 10,000 mg/kg and 2,300 mg/kg, respectively. After 100 days, the TPH contents decreased about 70% in the pile A and 30% in the pile B. Also, n-$C_{17}$/pristane and n-$C_{18}$/phytane ratios in all pile were significantly changed. The microbial densities in the pile A was increased by approximately $10^7$ CFU/g-soil~$10^8$ CFU/g-soil, but there was almost no changed in the pile B. The average biodegradation rates were calculated about 66.8 mg/kg-day in the pile A and 10.9 mg/kg-day in the pile B. Over the course of operation period, pile temperature was considered the major limiting factor for the efficiency of all biopiles.

Design of 808nm GRIN-SCH Quantum Dot Laser Diode (808nm GRIN-SCH 양자점 레이저 다이오드 설계)

  • Chan, Trevor;Son, Sung-Hun;Kim, Kyoung-Chan;Kim, Tae-Geun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.131-131
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    • 2010
  • The power of semiconductor laser diodes has been limited primarily by the heating effects which occur at high optical intensities. The actual limiting event can take one of a number of forms such as. catastrophic optical damage or filamentation. A general approach to this problem is to design a heterostructure which creates a high powered output while maintaining low internal optical intensities. A graded index separate confinement heterostructure (GRIN-SCH) is one such structure that accomplishes the above task. Here, the active region is sandwiched between graded index layers where the index of refraction increases nearer to the active layer. This structure has been shown to yield a high efficiency due to the confinement of both the optical power and carriers, thereby reducing the optical intensity required to achieve higher powers. The optical confinement also reinforces the optical beam quality against high power effects. Quantum dots have long been a desirable option for laser diodes due to the enhanced optical properties associated with the zeroth dimensionality. In our work, we use PICS3D software created by Crosslight Software Inc. to simulate the performance of In0.67A10.33As/A10.2Ga0.8AsquantumdotsusedwithaGRIN-SCH. The simulation tools are used to optimize the GRIN-SCH structure for high efficiency and optical beam quality.

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Emission Plasma Spectroscopy of High-pressure Microdischarges

  • Lee, Byeong-Jun;Ju, Yeong-Do;Kim, Seung-Hwan;Ha, Tae-Gyun;Gong, Hyeong-Seop;Park, Yong-Jeong;Park, Jong-Do;Nam, Sang-Hun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.253.2-253.2
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    • 2014
  • Micro hollow cathode discharges (MHCDs) are high-pressure, non-equilibrium discharges. Those MHCDs are useful to produce an excimer radiation. A major advantage of excimer sources is their high internal efficiency which may reach values up to 40% when operated under optimum conditions. To produce strong excimer radiation, the optimisation of the discharge conditions however needs a detailed knowledge of the properties of the discharge plasma itself. The electron density and temperature influence the excitation as well as plasma chemistry reactions and the gas temperature plays a major role as a significant energy loss process limiting efficiency of excimer radiation. Most of the recent spectroscopic investigations are focusing on the ultraviolet or vacuum ultraviolet range for direct detection of the excimer. In our experiments we have concentrated on investigating the micro hollow cathodes from the near UV to the near infrared (300~850 nm) to measure the basic plasma parameters using standard plasma diagnostic techniques such as stark broadening for electron density and the relative line intensity method for electron temperature. Finally, the neutral gas temperature was measured by means of the vibrational rotational structures of the second positive system of nitrogen.

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Operating parameters in electrodialysis membrane processes for removal of arsenic in groundwater (지하수내 비소제거를 위한 전기투석 막여과 운전인자 연구)

  • Choi, Su Young;Park, Keun Young;Lee, Seung Ju;Choi, Dan Bi;Park, Ki Young;Kim, Hee Jun;Kweon, Ji Hyang
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.4
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    • pp.449-457
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    • 2016
  • In this study, the effectiveness of electrodialysis in removing inorganic arsenic from groundwater was investigated. To evaluate the feasibility of the electrodialysis, operating parameters such as treatment time, feed concentration, applied voltage and superficial velocity were experimentally investigated on arsenic removal. The higher conductivity removal and arsenic removal efficiency were obtained by increasing applied voltages and operation time. An increase of salinity concentrations in arsenic polluted groundwater exerted no effects on the arsenic separation ratios. Arsenic polluted waters were successfully treated with stack voltages of 1.8 ~ 2.4 V/cell-pair to approximately 93.4% of arsenic removal. Increase flow rate in diluate cell gave positive effect to removal rate. However, increase of superficial velocity in the concentrated cell exerted no effects on either the conductivity reduction or on the separation efficiency. Hopefully, this paper will provide direction in selecting appropriate operating conditions of electrodialysis for arsenic removal.

Effect of Cutting Frequency and Nitrogen Fertilization on Productivity of Reed Canarygrass ( Phalaris arundinacea L.) (유휴 논토양에서 Reed Canarygrass의 생산성에 대한 예취빈도와 질소시비 효과)

  • 조익환;이주삼
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.17 no.4
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    • pp.407-414
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    • 1997
  • In this study, the optimum cutting 6equency and level of mineral nitrogen fertilization were investigated for the production of Reed canarygrass in uncultivated rice paddy. The results are summarized as follows; 1. Higher relative dry matter yields were recorded in 2nd cut of plots with 3 and 5 cutting frequencies, and 3rd cut of plot with 4 cutting kquency, respectively. 2. With no nitrogen fertilization, mean dry matter yields per year were 6.2~7.6 tonsha and the highest yield appeared in plot with 4 cutting 6equency. 3. The increased fertilization of mineral nitrogen resulted in the increased dry matter yield. Significantly higher dry matter yields than that of no nitrogen fertilization were recorded in fertilization of 90 kg nitrogen per year in 3 cutting fequency, 240 kg in 4 cutting frequency and 150 kg in 5 cutting 6equency respectively. 4. Efficiency of dry matter production with nitrogen fertilization(kg DMkg N) was higher in 30kg Nhalcut in 3 and 5 cutting eequency, 60kg Nhalcut in 4 cutting 6equency respectively. In each cutting kequency, the higher efficiency of dry matter production appeared in 1st cut in 3 cutting kequency, and 2nd cut in 4 and 5 cutting 6equency respectively. 5. Economic N level(kg/ha) was 179.5~242.3kg/ha in 3 cutting 6equency, and 189.6-241.6kg/ha and 167.0 ~253.2kg/ha in 4 and 5 cutting 6equency respectively, and marginal dry matter yields were 11.4~ 12.3 tons/ ha, 11.2 ~ 11.8 tons/ha and 8.3 ~9.1 tons/ha in 3, 4 and 5 cutting 6equency respectively. 6. The limiting N fertilization level to the highest dry matter were estimated to be 569.9kg/ha, 492.4kg/ha and 654.lkg/ha in 3, 4 and 5 cutting kequency respectively.

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Studies on the Preparation of Food Proteins from Castor Bean Protein (피마자 단백질의 식품화를 위한 연구)

  • Yoon, Joo-Ok
    • Korean Journal of Food Science and Technology
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    • v.12 no.4
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    • pp.263-271
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    • 1980
  • Detoxified and deallergenized castor bean protein isolate was prepared from defatted castor bean pomace for use in animal feedstuffs and human foods. Succinylation and acetylation of the ${\varepsilon}-amino$ groups of the protein improved markedly the water solubility of the protein at $pH\;7{\sim}8$. The results of the amino acid analysis of the protein isolate revealed that the sulfur-containing amino acids and L-lysine were limiting amino acids and that succinylation and acetylation caused some little loss of the amino acid content. The L-methionine enriched plastein was synthesized from the protein isolate or the acylated protein isolates and DL-methionine ethyl ester by one step process with papain. By this method the extent of incorporation of L-methionine was about 50%. Pepsin hydrolyzed both unmodified and modified protein isolates at the same rate (about 92%). Tryptic hydrolysis, however, was less for the succinylated protein isolates (about 42%) and less for the acetylated protein isolates (about 26%). The protein efficiency ratio of L-methionine enriched protein isolate (about 2.5 weight %) was 90% that of reference casein. The protein efficiency ratio values of succinylated (88%) and acetylated (84%) protein isolate were 55 and 69% of reference casein, respectively.

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Transonic buffet alleviation on 3D wings: wind tunnel tests and closed-loop control investigations

  • Lepage, Arnaud;Dandois, Julien;Geeraert, Arnaud;Molton, Pascal;Ternoy, Frederic;Dor, Jean Bernard;Coustols, Eric
    • Advances in aircraft and spacecraft science
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    • v.4 no.2
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    • pp.145-167
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    • 2017
  • The presented paper gives an overview of several projects addressing the experimental characterization and control of the buffet phenomenon on 3D turbulent wings in transonic flow conditions. This aerodynamic instability induces strong wall pressure fluctuations and therefore limits flight domain. Consequently, to enlarge the latter but also to provide more flexibility during the design phase, it is interesting to try to delay the buffet onset. This paper summarizes the main investigations leading to the achievement of open and closed-loop buffet control and its experimental demonstration. Several wind tunnel tests campaigns, performed on a 3D half wing/fuselage body, enabled to characterize the buffet aerodynamic instability and to study the efficiency of innovative fluidic control devices designed and manufactured by ONERA. The analysis of the open-loop databases demonstrated the effects on the usual buffet characteristics, especially on the shock location and the separation areas on the wing suction side. Using these results, a closed-loop control methodology based on a quasi-steady approach was defined and several architectures were tested for various parameters such as the input signal, the objective function, the tuning of the feedback gain. All closed-loop methods were implemented on a dSPACE device able to estimate in real time the fluidic actuators command calculated mainly from the unsteady pressure sensors data. The efficiency of delaying the buffet onset or limiting its effects was demonstrated using the quasi-steady closed-loop approach and tested in both research and industrial wind tunnel environments.

Drivers of Crop Productivity and Resource Use Efficiencies in Apple between Western and Eastern States in the US

  • Kim, Soo-Hyung
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2015.08a
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    • pp.18-28
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    • 2015
  • Apple is cultivated under various climatic conditions in many parts of the world. Better understanding of how climate, genotype, soil, and management factors interact to determine crop productivity will improve our ability to optimize crop selection, management strategies, and resource use efficiencies. We developed and applied a physiology-based apple canopy model to evaluate how climatic factors and crop phenotypes interact to determine biomass accumulation, radiation use efficiency (RUE), and water use efficiency (WUE) at multiple production sites between western and eastern states of the US including WA, CA, NY, WV, and PA. Our results indicate that solar radiation is a dominant factor limiting biomass production in the eastern states while VPD is the primary factor governing crop water use across eastern and western states during the peak growing season. Crop RUE and WUE were strongly correlated in the western states but not in the eastern states while VPD showed highly negative correlation with both RUE and WUE across all locations. The RUE improved with increasing fraction of diffuse radiation ($f_{df}$) and the $RUE-f_{df}$ relationships revealed distinctive responses between western and eastern states. Overall, the eastern locations exhibited slightly higher RUE and WUE than the western locations. However, overall productivity and total water use were greater in the western states. A clear decline of productivity with increasing temperature and afternoon VPD past an optimum was predicted in the western locations but this pattern was less clear in the eastern locations. We also discuss potential phenotypes with specific physiological and morphological traits that are differentially suitable for western and eastern locations. Our results provide plausible, spatially explicit explanations and insights to disentangle the complex relationships between crop productivity, resource use efficiencies, phenotype, and climate drivers in apple grown in the US.

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BIM-based Efficiency Review of Barrier Free Certification Items (장애물 없는 생활환경(BF)인증 항목의 BIM기반 효율성 검토)

  • Kang, Kyung-Ha;Son, Byeung-Hun;So, Seung-Young
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.2
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    • pp.183-194
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    • 2022
  • This study conducted a survey for BIM experts as a basic study to improve the efficiency of a BIM-based review of the BF certification evaluation method. By limiting the buildings to elementary schools, the first survey was conducted to extract the mandatory facilities from the BF certification evaluation items according to the evaluation criteria, and 63 out of a total of 94 evaluation items were extracted. The extracted facilities were intermediary facilities, internal facilities, and sanitary facilities. The second survey provided detailed calculation criteria for BF certification evaluation items, and through investigating the possibility of BIM-based review, 31 items were derived. In the 3rd and final survey, when asked about the effectiveness of the current CAD-based and BIM-based evaluation methods, the BIM-based evaluation method showed 96.8% effectiveness and the CAD-based evaluation method showed 3.2% effectiveness.

Disinfection of Water by Ultrasonic Irradiation (초음파 검사에 의한 수중의 살균처리)

  • 손종렬;유병성
    • Journal of environmental and Sanitary engineering
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    • v.14 no.1
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    • pp.54-61
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    • 1999
  • The industrial techniques of ultrasound have been used in the various fields, such as cleaning, medical surgery, emulsification, cell disruption etc. Especially the application of cell disruption was interested in the field of disinfection process in water by ultrasonic irradiation. It has been recognized that the ultrasounds are irradiated in aqueous solution, cavitation bubbles are generated and shock waves of high temperature and pressure are emitted as the bubbles are developed and finally broken, which function as a energy source to promote reaction efficiencies of various kinds of chemical reactions such as disinfection reaction in water. Therefore, this study was performed to apply the ultrasound for the disinfection method of infected drinking raw water and to discuss the limiting factors such as pH, sample volume and reaction temperature influenced on the removal efficiency of E. coli from experimental analysis of the results obtained in bench-scale plant. For the experiments to measure the influence of reaction parameters in the ultrasonic disinfection process, escalated reactivity of aqueous solutions was excellent when pH in aqueous solution was low, and sample volume was small. On the contrary, the reactivity of disinfection became elevated when reaction temperature was high. It was found that the rate constant of disinfection reaction was applied by Chick's law, reaction kinetics of Chick's law was irreversible and pseudo-first order at all the tested conditions.As a conclusion it appeared that the technology using ultrasonic irradiation can be applied to the treatment of disinfection in infected water which are difficult to be treated by conventional methods.

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