• Title/Summary/Keyword: attached growth system

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Higher Biomass Productivity of Microalgae in an Attached Growth System, Using Wastewater

  • Lee, Seung-Hoon;Oh, Hee-Mock;Jo, Beom-Ho;Lee, Sang-A;Shin, Sang-Yoon;Kim, Hee-Sik;Lee, Sang-Hyup;Ahn, Chi-Yong
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1566-1573
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    • 2014
  • Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of $9.1g\;m^{-2}day^{-1}$ and $1.9g\;m^{-2}day^{-1}$, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.

The Study on Evaluating Performances of Lab Sacle-Advanced $A_{2}O$ with Changing System Using Biofilm Process (생물막 담체를 이용한 실험실 규모 $A_{2}O$공법의 시스템 변형에 따른 고도처리 성능 평가에 관한 연구)

  • Kim, Min-Sik;Kang, Gu-Young
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.2
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    • pp.209-218
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    • 2012
  • Recently, as reinforced water quality standards for wastewater has been announced, more efficient and more powerful wastewater treatment processes are required rather than the existing activated sludge process. In order to meet this demands, we evaluate Task 1-4 about lab scale $A_{2}O$ process using biofilm media. Task 1, 2, and 3 use 'Module A' which has 4 partitions (Anoxic/Anerobic/Oxic/Oxic). Task 4 uses 'Module B' which has 2 partitions including a denitrification reactor with an Inclined plug flow reactor (IPFR) and a nitrification reactor with biofilm media. The denitrification reactor of Module B is designed to be upward flow using IPFR. The result of evaluating at each Task has shown that attached growth system has better capacity of removal efficiency for organic matter and nitrogen with the exception of phosphorus. Task 4 which has the most outstanding removal efficiency has 90.5% of $BOD_{5}$ removal efficiency, 97.8% of ${NH_4}^{+}-N$ removal efficiency, 65% of T-N removal efficiency and 92% of T-P removal efficiency with additional chemical phosphorus removal system operated at HRT 9hr, Qi:Qir 1:2, and BOD/T-N ratio 2.7.

Single Image-Based 3D Tree and Growth Models Reconstruction

  • Kim, Jaehwan;Jeong, Il-Kwon
    • ETRI Journal
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    • v.36 no.3
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    • pp.450-459
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    • 2014
  • In this paper, we present a new, easy-to-generate system that is capable of creating virtual 3D tree models and simulating a variety of growth processes of a tree from a single, real tree image. We not only construct various tree models with the same trunk through our proposed digital image matting method and skeleton-based abstraction of branches, but we also animate the visual growth of the constructed 3D tree model through usage of the branch age information combined with a scaling factor. To control the simulation of a tree growth process, we consider tree-growing attributes, such as branching orders, branch width, tree size, and branch self-bending effect, at the same time. Other invisible branches and leaves are automatically attached to the tree by employing parametric branch libraries under the conventional procedural assumption of structure having a local self-similarity. Simulations with a real image confirm that our system makes it possible to achieve realistic tree models and growth processes with ease.

Experimental Basic Study on Growth Characteristics of Plant with Various Liquids (액체 종류에 따른 식물의 성장 특성 기초 실험)

  • Park, Jeong-Yeon;Kim, Jeongbae
    • Journal of Institute of Convergence Technology
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    • v.4 no.1
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    • pp.1-4
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    • 2014
  • This study was experimentally performed to show the growth characteristics of one specified plant with various liquids, which can be purchased easily. To do that, this study measured the number of leaves attached to the plant sample and the height of liquids everyday during almost 15 days on summer season in the laboratory room. From the experiments, we revealed that the remained number of leaves can be related with the liquid height.

Fatigue Crack Growth Equation considered the Effect of Stress Ratio (응력비의 영향을 고려한 표면피로균열의 균열성장식)

  • 강용구;김대석
    • Journal of Ocean Engineering and Technology
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    • v.12 no.1
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    • pp.39-49
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    • 1998
  • In this work, fatigue tests by axial loading were carried out to investigate the effect of stress ratio on the growth behaviors of surface fatigue crack for SM45C steel and Al 2024-T4 alloy. The growth behaviors of surface crack have been monitored during fatigue process by measuring system attached CCTV and monitor. When the growth rates of surface crack were investigate by the concept of LEFM based on Newman-Raju's .DELTA.K, the dependence of stress ratio appears both SM45C steel and Al 2024-T4 alloy. Therefore, modified stress intensity factor range, .DELTA.K' [=(1+R)/sup n/.DELTA.K] are intorduced to eliminate the dependence of stress ratio. Using .DELTA.K', it is found that the dependence of stress ratio disappears both SM45C steel and Al 2024-T4 alloy.

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Nodulation and Early Growth of Supernodulating Mutants in Soybean (초다 근류착생 돌연변이체 콩의 뿌리혹 형성 및 초기생육)

  • 이석하;이홍석
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.1
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    • pp.16-21
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    • 1992
  • Increase in nodulation and nitrogen fixation was achieved partly through the isolation of supernodulating soybean mutant plants. This experiment was conducted to compare nodulation, nitrogen fixation, and early growth characters of wild type 'Bragg' with those of its supernodulating soybean mutant, 'nts 382' and 'nts 246'. At 31 days after planting, nodule dry weight of nts mutants was 2.5 to 3.7 times greater than that of Bragg. Higher nodulation of nts mutants showed the reduced top growth, indicating that photosynthates might be translocated and used for nodule growth attached to the root system. Total acetylene reduction activity was higher in nts mutants than Bragg, whereas specific acetylene reduction activity of nts mutant was the half of that of Bragg. Mixture of nts mutants and Bragg did not affect nodulation characters each other, suggesting that factors affecting supernodulating characters exist inside rather than outside the root system.

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Manganese Zinc Ferrite Singel Crystal Growth by Continuous Crystal Growing Method (연속성장법에 의한 Mn-Zn Ferrite 단결정 성장)

  • 정재우;오근호
    • Journal of the Korean Ceramic Society
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    • v.29 no.7
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    • pp.539-543
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    • 1992
  • The continuous growth method was developed for Mn-Zn Ferrite single crystals. It is a new process that the polycrystalline MnχZn1-χFe2O4 raw materials are supplied continuously from the powder feeding system to the crucible heated by R.F. induction and melted in the crucible, and after the single crystals seed is attached to crucible's hole, the crystals are pulled downward with rotation. Growing the crystals by using the growth method different from the conventional Bridgman or Floating Zone method, we defined the factors having effect on the crystal growing through the pre-experiments. They are temperature distribution in the crucible, melt velocity according to its height, wettability between the crucible's bottom and melt. Therefore, Mn-Zn Ferrite single crystals were to be grown by attaining the appropriate melt height in the crucible, powder feeding rate, temperature gradient between the crucible and interface, crystal growing speed, and this method was confirmed to have possibility for single crystal growing.

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Barley Growth and Labor-Saving Efficiency as Using Barley Seeder Synchronized with Rice Harvesting (벼 수확동시 보리파종기 이용에 따른 보리생육특성 및 생력효과)

  • 김양길;이중호;서재환;박종철
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.49 no.3
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    • pp.179-183
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    • 2004
  • This study was conducted to investigate the effects of using barley seeder attached to rice harvest combine that could be used in rice harvesting and barley seeding simultaneously on the growth characteristics of barley and labor-saving efficiency. In developed seeding system, burley seeding was earlier about 5 days than in the conventional system, because of conducting rice Harvesting and barley seeding simultaneously. The germination of barley seed after seeding was protected from drought damage by the rice straw covering. Among the growth characteristics of barley using developed seeding system, the number of spikes per m$^2$ was lower than that of conventional system, but others showed longer culm length, hove kernel numbers per spike and heavier 1,000 kernel weight than those of conventional system. Developed seeding system resulted in about 57% labor-saving efficiency compared with conventional system. The cost of whole works from seeding to harvest of barley was saved about 8% compared with conventional system. A total of income increased about 16% than that of conventional system.

Low Temperature Effects on the Nitrification in a Nitrogen Removal Fixed Biofilm Process Packed with SAC Media

  • Jang, Se-Yong;Byun, Im-Gyu
    • Journal of Environmental Science International
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    • v.22 no.1
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    • pp.1-6
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    • 2013
  • A fixed biofilm reactor system composed of anaerobic, anoxic(1), anoxic(2), aerobic(1) and aerobic(2) reactor was packed with synthetic activated ceramic (SAC) media and adopted to reduce the inhibition effect of low temperature on nitrification activities. The changes of nitrification activity at different wastewater temperature were investigated through the evaluation of temperature coefficient, volatile attached solid (VAS), specific nitrification rate and alkalinity consumption. Operating temperature was varied from 20 to $5^{\circ}C$. In this biofilm system, the specific nitrification rates of $15^{\circ}C$, $10^{\circ}C$ and $5^{\circ}C$ were 0.972, 0.859 and 0.613 when the specific nitrification rate of $20^{\circ}C$ was assumed to 1.00. Moreover the nitrification activity was also observed at $5^{\circ}C$ which is lower temperature than the critical temperature condition for the microorganism of activated sludge system. The specific amount of volatile attached solid (VAS) on media was maintained the range of 13.6-12.5 mg VAS/g media at $20{\sim}10^{\circ}C$. As the temperature was downed to $5^{\circ}C$, VAS was rapidly decreased to 10.9 mg VAS/g media and effluent suspended solids was increased from 3.2 mg/L to 12.0 mg/L due to the detachment of microorganism from SAC media. And alkalinity consumption was lower than theoretical value with 5.23 mg as $CaCO_3$/mg ${NH_4}^+$-N removal at $20^{\circ}C$. Temperature coefficient (${\Theta}$) of nitrification rate ($20^{\circ}C{\sim}5^{\circ}C$) was 1.033. Therefore, this fixed film nitrogen removal process showed superior stability for low temperature condition than conventional suspended growth process.

Development and Characterization of Membrane for Local Delivery of Cephalexin

  • Shin, Sang-Chul;Oh, In-Joon;Cho, Seong-Jin
    • Archives of Pharmacal Research
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    • v.19 no.1
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    • pp.1-5
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    • 1996
  • Laminated films composed of drug-containing reservoir layer and drug-free membrane were prepared. Zero-order drug release with lag time was achieved by laminating drug-free film onto the reservoir layer, while burst effect was observed on cast-on film. The rate controlling membrane was either attached to or cast directly into the reservoir. The release rate was independent on the reservoir composition but dependent on the composition of rate-controlling membrane. In growth inhibitory test of cephalexin from Eudragit RS film to Streptococcus Mutans, the disk even after release test for 72 hours showed more bacterial growth inhibition than that of control. Permeation of drug through rat skin was proportional to the HPC fraction in the film. We could control the release of cephalexin from the film by changing the fraction of Eudragit RS, HPC and DEP content. Consequently, Eudragit RS/HPC film was found to be very effective system for local delivery of drugs.

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