• 제목/요약/키워드: dark energy

검색결과 314건 처리시간 0.028초

Chlamydomonas reinhardtii 이용한 명반응 증식 특성 및 암반응에서 수소 생산 (Multiplication conditions in light reaction and hydrogen production in dark fermentation using Chlamydomonas reinhardtii)

  • 김지성;박호일;김동건;공경택;조경숙;박대원
    • 한국수소및신에너지학회논문집
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    • 제16권1호
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    • pp.17-24
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    • 2005
  • We experimented on growth in light and production of hydrogen and organic matters in dark fermentation by using C. reinhardtii. In the light, growth rate of C. reinhardtii following $CO_2$ fixation was proportional to consumption rate of nitrogen source. And the starch in cell was accumulated more when the period of culture was lengthened more. But the accumulation rate of starch in cell was decreased when the growth rate of cell become dull. In the dark fermentation, the production volume and production rate of hydrogen were the highest value in the mid exponential state among other states. The utilization efficiency of substrate was better in the early exponential state than other states. In production of organic matters, acetic acid didn't change remarkably and ethanol showed the highest value in early exponential state.

클로렐라의 동조배양법에 의한 세포분열의 생리학적 연구 1 (Physiological studies on cell division by the technique of synchronous culture of chlorella (I))

  • 이영녹;이종삼
    • 미생물학회지
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    • 제7권1호
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    • pp.1-9
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    • 1969
  • Changes in the phosphorylation of Chlorella cells during the life cycle the aulotrophic and micotrophic synchronous culture were followed under the light and dark. 1. In the autotrophic culture of Chlorella the amounts of esterified phosphate compounds of the algal cell under the light increased during the growing period and decreased strikingly in the ripening period showing a peak at the $L_1$ i/-cell stage. 2. TRhe amount of total esterified phosphate compounds of the cell under the dark, however, decreased during the growing period and then kept fairly constnat during the ripening nad division periods showing the greates activity of the oxidative phosphorylation in the early growing stage. 3. It is presumed that the energy requirement of the dividing algal cell in the autotrophic culture is fulfilled prior to the nuclear division mostly by the photosynthetic phosphorylation. 4. In the mixotrophic culture, the amount of esterified phosphate compounds of the algal cells under the light increased during the growing period and decreased during the late ripening and early division periods showing a peak in the $L_2$-cell stage as in the case of the phosphorylation under the dark. 5. The phosphorylation of the fell grown in the glucose medium is more active under the dark than under the light in the stages of the growing and early ripening periods. 6. It is considered that the excess glucose in the algal cell not only promotes the oxidative phosphorylation but also inhibits the photosynthetic phosphorylation of the cell. 7. It is presumed that the energy requirement of the dividing algal cell in the glucose medium is fulfilled prior to the nuclear division by the combined action of oxidative and photosynthetic phosphorylation, mostly by the oxidative phosphorylation.

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A STUDY OF LYNDS 1251 DARK CLOUD: II. INFRARED PROPERTIES

  • LEE YOUNGUNG
    • 천문학회지
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    • 제29권2호
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    • pp.107-117
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    • 1996
  • We have studied the star forming activities and dust properties of Lynds 1251, a dark cloud located at relatively high galactic latitude. Eleven IRAS point sources identified toward Lynds 1251 are discussed. Estimate of stellar masses, and far-infrared lumnosities of the young stars associated with two prominent IRAS point sources imply that these are T-Tauri stars with masses smaller than $0.3 M_\bigodot$. The low dust temperature of 27 K and low ratio of FIR emission to hydrogen column density are probably due to the lack of internal heating sources. Presumably two low mass young stars do not have enough energy to heat up the dust and gas associated. The dust heating is dominated by the interstellar heating source, and the weaker interstellar radiation field can explain the exceptionally low dust temperatures found in Lynds 1251. The estimated dust mass of Lynds 1251 is just $\~1M_\bigodot$, or about 1/1000 of gas mass, which implies that there must be a substantial amount of colder dust. The infrared flux at $100{\mu}m$ is matching well with $^{13}CO$ peak temperature, while the $^{12}CO$ integrated intensity is matching with the boundary of dust emission. Overall, the dust properties of Lynds 1251 is similar to those of normal dark clouds even though it does have star forming activities.

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다크웹 환경에서 산업기술 유출 탐지 시스템 (Industrial Technology Leak Detection System on the Dark Web)

  • 공영재;장항배
    • 스마트미디어저널
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    • 제11권10호
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    • pp.46-53
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    • 2022
  • 오늘날 4차 산업 혁명과 대규모 R&D 지원으로 인해 국내 기업은 세계 기술력 수준의 산업기술을 보유하기 시작하였으며 중요한 자산으로 변모하였다. 국가는 기업의 중요한 산업기술을 보호하고자 국가핵심기술로 지정하였으며, 특히 원자력, 조선, 반도체와 같은 기술이 유출될 경우 해당 기업뿐만 아니라 국가 차원에서도 심각한 경쟁력 손실로 이어질 수 있다. 매년 내부자 유출, 랜섬웨어 그룹의 해킹공격, 산업스파이에 산업기술 탈취 시도가 증가하고 있으며, 탈취된 산업기술은 다크웹 환경에서의 은밀하게 거래가 이루어진다. 본 논문에서는 다크웹 환경에서 은밀하게 이루어지는 산업기술 유출을 탐지하는 시스템을 제안한다. 제안된 모델은 먼저 OSINT 환경에서 수집한 정보를 이용하여 다크웹 크롤링을 통한 데이터베이스를 구축한다. 이후 KeyBERT 모델을 이용한 산업기술 유출 키워드를 추출한 후 다크웹 환경에서의 산업기술 유출 징후를 정량적 수치로 제안한다. 마지막으로 식별된 다크웹 환경에서의 산업기술 유출 사이트를 기반으로 PageRank 알고리즘 통한 2차 유출 가능성을 탐지한다. 제안된 모델을 통해 27,317개의 중복 없는 다크웹 사이트를 수집하였으며, 100개의 원자력 특허에서 총 15,028개의 원자력 관련 키워드를 추출하였다. 가장 높은 원자력 유출 다크웹 사이트를 기반으로 2차 유출을 탐지한 결과 12개의 다크웹 사이트를 식별하였다.

결정질 태양전지 모듈 내부 저항의 Missmatch 분석 (The Analysis of missmatch with resistance on Si-PV module)

  • 지양근;공지현;강기환;유권종;원창섭;안형근;한득영
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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    • pp.98-103
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    • 2009
  • In this paper, we test the electrical resistance of flat wire in the PV module. normally solar cell has two kind of flat wire(inter connection ribbon and bus bar ribbon). we found the phenomenon that has a unbalance with resistance when we make a wiling between of string. So, we measurement the resistance of flat wire each other. and analysis of missmatch with resistance between flat wires on PV module. next to survey of IR picture on missmatch flat wire samples for analyze of missmatch with current in the wire. and we perform IR test with solar cell that has a connection with flat wire for test the effect of missmatch resistance on solar cell. Finally we perform the Dark I-V test for survey of effect by the unbalance of resistance. By the result of Dark I-V test, the series resistance of existing connection sample is large more then innovated connection sample.

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국내 딸기 재배품종의 잎절편 배양으로부터 고빈도 식물체 재생 (High Frequency Plant Regeneration from Leaf Explant Cultures of Domestic Cultivated Strawberry (Fragaria x ananassa Duch))

  • 조미애;최규명;고석민;민성란;정화지;유장렬;최필선
    • Journal of Plant Biotechnology
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    • 제32권3호
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    • pp.175-179
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    • 2005
  • 딸기 기내배양으로부터 고빈도 식물체재생 방법을 개발하기 위하여 여봉딸기의 잎과 엽병절편을 0.5 mg/L IBA와 3.2 mg/L kinetin, BAP, zeatin을 각각 조합 첨가한 MS배지에서, 그리고 1주, 2주, 4주동안 암 전처리한 잎 절편을 0.5 mg/L IBA와 3.2 mg/L zeatin이 첨가된 배지에서 6주동안 16시간 광주기 조건으로 배양하였다. 신초 발생은 잎을 adaxial상태로 치상하였을때 절단부위로부터 안토시아닌 색소를 함유한 녹색 캘러스로부터 유도되었고 (57.0%), 엽병의 경우 절단부위로부터 직접 발생되었다(6.3%). 캘러스와 신초발생율은 잎 절편 크기가 클수록 ($1.0{\sim}1.5\;cm^2$) 높았으며, 암 전처리는 그 발생율을 점차 증가시켜 4주동안 암 전처리한 후 16시간 광조건으로 옮겼을 때 가장 높은 발생율 (87.0%)을 얻을 수 있었다. 이러한 shoot발생율 (87%)은 암 전처리를 하지 않은 대조군 (27%) 에 비하여 현저하게 증가된 것이다. 신초를 분리하여 1/2 MS기본배지에 옮겨20동안 배양하였을 때 뿌리가 발생되었으며, 이때 소식물체를 토양에 옮겨 순화시켰다.

Deep Learning the Large Scale Galaxy Distribution

  • Sabiu, Cristiano G.
    • 천문학회보
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    • 제45권1호
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    • pp.49.3-49.3
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    • 2020
  • I will give an overview of the recent work in deriving cosmological constraints from deep learning methods applied to the large scale distribution of galaxies. I will specifically highlight the success of convolutional neural networks in linking the morphology of the large scale matter distribution to dark energy parameters and modified gravity scenarios.

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고율 조류 생세포체 배양지에서 조사 조건으로 본 조류 배양 특성 (Algae Culture Characteristics Viewed with Continuous and Cyclic Irradiation in High Rate Algae Biomass Culture Pond)

  • 공석기
    • 환경위생공학
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    • 제14권3호
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    • pp.123-129
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    • 1999
  • The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

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다결정 실리콘 박막으로 구성된 Metal-Semiconductor-Metal 광검출기의 제조 (Metal-Semiconductor-Metal Photodetector Fabricated on Thin Polysilicon Film)

  • 이재성;최경근
    • 한국전기전자재료학회논문지
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    • 제30권5호
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    • pp.276-283
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    • 2017
  • A polysilicon-based metal-semiconductor-metal (MSM) photodetector was fabricated by means of our new methods. Its photoresponse characteristics were analyzed to see if it could be applied to a sensor system. The processes on which this study focused were an alloy-annealing process to form metal-polysilicon contacts, a post-annealing process for better light absorption of as-deposited polysilicon, and a passivation process for lowering defect density in polysilicon. When the alloy annealing was achieved at about $400^{\circ}C$, metal-polysilicon Schottky contacts sustained a stable potential barrier, decreasing the dark current. For better surface morphology of polysilicon, rapid thermal annealing (RTA) or furnace annealing at around $900^{\circ}C$ was suitable as a post-annealing process, because it supplied polysilicon layers with a smoother surface and a proper grain size for photon absorption. For the passivation of defects in polysilicon, hydrogen-ion implantation was chosen, because it is easy to implant hydrogen into the polysilicon. MSM photodetectors based on the suggested processes showed a higher sensitivity for photocurrent detection and a stable Schottky contact barrier to lower the dark current and are therefore applicable to sensor systems.

PICTS방법에 의한 Boron이온을 주입시킨 반절연성 GaAs의 깊은준위에 관한 연구 (A study on the deep levels in boron ion implanted semi-insulating GaAs by PICTS)

  • 최현태;김인수;이철욱;손정식;김영일;배인호
    • E2M - 전기 전자와 첨단 소재
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    • 제8권4호
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    • pp.426-433
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    • 1995
  • Effect of boron in GaAs have been investigated by photo induced current transient spectroscopy(PICTS). The starting material was undoped liquid encapsulated Czochralski(LEC) semi insulating GaAs and boron ion implantation at 150keV energy was conducted with dose of 10$\^$12/ and 10$\^$13/ions/cm$\^$2/. In ion implanted samples, the peaks related arsenic vacancy(V$\_$As/) were decreased but complex lattice defect was increased with annealing temperature. U band was observed at ion implanted(10$\^$13/ ions/cm$\^$2/) and thermally treated(550.deg. C) sample. More negative peak was detected after annealing at temperature between 600 and 700.deg. C. The measurement of dark current showed that the formation of B$\_$GA/-V$\_$As/, complex defect and complex lattice defect by ion implantation were a reasonable explanation for the decrease in dark current.

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