• 대한토목학회논문집
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• 제2권1호
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• pp.33-44
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• 1982

활성(活性)슬러지법(法)에 의한 폐수처리(廢水處理)에서 가장 중요(重要)한 단위조작(單位操作)의 하나인 폭기특성(曝氣特性)을 연구(硏究)할 목적(目的)으로 드라프트 튜브가 부착(附着)된 팔각형(八角形) 폭기조(曝氣槽)와 piched blade형(形)의 터빈을 설치(設置)한 폭기장치(曝氣裝置) 모델을 제작(製作)하여 터빈의 모양을 여러가지로 변화(變化)시켜 이 모델에서의 산소이동속도(酸素移動速度), 소비동력(消費動力) 및 유속(流速)과 유태(流態)를 실험(實驗)에 의하여 측정(測定) 및 조사(調査)하고 평가(評價)했다. 그리고 그 결과(結果)를 무차원(無次元)으로 수식화(數式化)하여 폭기조(曝氣槽)에서 폭기특성(曝氣特性)을 연구(硏究)함으로써, 폭기조(曝氣槽)에서의 터빈의 합리적(合理的)인 모양 결정(決定) 시도(試圖)하였다.

• 동력기계공학회지
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• 제11권3호
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• pp.22-28
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• 2007

Liquefied gas vaporizer is a machine to vaporize liquefied gas such as liquid nitrogen($LN_{2}$), liquefied natural gas(LNG), liquid oxygen($LO_{2}$) etc. For the air type vaporizer, the frozen dew is created by temperature drop (below 273 K) on vaporizer surface. The layer of ice make a contractions on vaporizer. The structure analysis on the heat transfer was studied to see the effect of geometric parameters of the vaporizer, which are length 1000 mm of various type vaporizer. Structure analysis result such as temperature variation, thermal stress and thermal strain have high efficiency of heat emission as increase of thermal conductivity. As the result, Frist, With-fin model shows high temperature distribution better than without-fin on the temperature analysis. Second, Without-fin model shows double contractions better then with-fin model under the super low temperature load on the thermal strain analysis. Third, Vaporizer fin can be apply not only heat exchange but also a stiffener of structure. Finally, we confirm that All model vaporizer can be stand for sudden load change because of compressive yield stress shows within 280 MPa on thermal stress analysis.

• Archives of Pharmacal Research
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• 제26권11호
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• pp.951-959
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• 2003

A series of typical (chlorpromazine, haloperidol and thioridazine) and atypical (risperidone, quetiapine, clozapine and olanzapine) antipsychotics were tested for effects on integrated bioenergetic functions of isolated rat liver mitochondria. Polarographic measurement of oxygen consumption in freshly isolated mitochondria showed that electron transfer activity at respiratory complex I is inhibited by chlorpromazine, haloperidol, risperidone, and quetiapine, but not by clozapine, olanzapine, or thioridazine. Chlorpromazine and thioridazine act as modest uncouplers of oxidative phosphorylation. The typical neuroleptics inhibited NADH-coenzyme Q reductase in freeze-thawed mitochondria, which is a direct measure of complex I enzyme activity. The inhibition of NADH-coenzyme Q reductase activity by the atypicals risperidone and quetiapine was 2-4 fold less than that for the typical neuroleptics. Clozapine and olanzapine had only slight effects on NADH-coenzyme Q reductase activity, even at 200 $\mu$ M. The relative potencies of these neuroleptic drugs as inhibitors of mitochondrial bioenergetic function is similar to their relative potencies as risk factors in the reported incidence of extrapyramidal symptoms, including tardive dyskinesia (TD). This suggests that compromised bioenergetic function may be involved in the cellular pathology underlying TD.

• 센서학회지
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• 제20권6호
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• pp.363-367
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• 2011

This paper proposes a highly-sensitive gas flow sensor with a simple structure. The sensor is composed of a micro-heater for heating the gas medium and a pair of temperature sensors for detecting temperature differences due to gas flow in a sealed chamber on one axis. Operation of the gas flow sensor depends on the transfer of heat through the air medium. The proposed gas flow sensor has the capability to measure gas flow rates <5 $cm^3$/min with a resolution of approximately 0.01 $cm^3$/min. Furthermore, this paper reports some additional experiment results, including the sensitivity of the proposed gas flow sensor as a function of operating current and the flow of different types of gas(oxygen, carbon dioxide, and nitrogen). The fabrication process of the proposed sensor is very simple, making it a good candidate for mass production.

• 한국산학기술학회논문지
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• 제6권2호
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• pp.116-121
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• 2005

폐수 처리를 위한 PVA 포괄 고정화 담체의 특성에 관한 연구를 실시하였다. 특히 PVA의 고정화 조건에 따른 용해도의 영향, 첨가제가 PVA 물성에 미치는 영향, 제작된 PVA gel의 질산화 처리 효율을 살펴보았다. PVA gel 제작 과정 중 진공을 걸어줄수록 그리고 동결온도가 낮을수록 PVA gel의 용해도는 감소하였다. PAC와 같은 첨가제를 넣었을 때 PVA gel의 용해도는 감소하였고 특히 organoclay를 넣었을 때 PAC에 비하여 25% 낮은 용해도를 보였다. 질산화 효율면에서는 PVA로 코팅한 담체가 기존의 부착 담체에 비하여 용질과 산소 확산의 제한 때문에 질산화율이 낮게 관찰되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1515-1517
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• 2002

$MnO_2$ is used for the oxide electrode of electrochemical equipments because of its good electric conductivity and low oxygen overpotential. The effect of additives on the properties of $MnO_2$ has been investigated to enhance the electric conductivity and the stability in an acid solution. In this research, the effect of Ni addition on ${\beta}-MnO_2$ was studied by the theoretical quantum chemical method. The calculation was carried out by the discrete variation $X{\alpha}$ method, which is a sort of the first principle method and use Hatre-Fock-Slater approximation. The electron energy level, the density of state, the bond overlap population, the charge density distribution and the net ionic transfer between cations and anions were calculated and discussed. The used cluster model was $(Mn_{10}NiO_{44})^{-44}$.

• 한국유체기계학회 논문집
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• 제14권6호
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• pp.61-67
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• 2011

The study is to analyze the chemical and heat-flow reactions in the hydrogen generation unit(autothermal reformer), using computational numerical tools. Autothermal reformer(ATR) is involved in complex chemical reaction, mass and heat transfer due to exothermic and endothermic reactions. Therefore it is necessary to reveal the effects of various operation parameters and geometries on the ATR performance by using numerical analysis. Numerical analysis needs to dominant chemical reactions that includes Full Combustion(FC) reaction, Steam Reforming(SR) reaction, Water-Gas Shift(WGS) reaction and Direct Steam Reforming(DSR) reaction. The objective of the study is to improve theoretically the reformer design capability for the goal of high hydrogen production in the autothermal reformer using methane. Hydrogen production reached maximum in a certain value of Oxygen to Carbon Ratio(OCR) or Steam to Carbon Ratio(SCR). When the longitudinal distance to dimeter ratio(L/D) is increased, hydrogen production increases.

• 센서학회지
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• 제21권1호
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• pp.46-52
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• 2012

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

• 대한화학회지
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• 제33권5호
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• pp.477-477
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• 1989

1,2-디클로로에탄에서 $[MoO_2(S_2CNEt_2)_2]$와 트리페닐포스핀과의 산소이동 반응에 대한 속도를 분광학적인 방법으로 측정하였다. 이 때 시간에 따라 흡광도가 증가하였다가 감소하였는데, 흡광도가 증가되는 단계는 중간체인 $[Mo_2O_3(S_2CNE_t2)_4]$의 생성 때문이고, 흡광도가 감소되는 단계는 이 생성물이 환원되는 과정이다. 제 1단계에서는 효소반응 메카니즘이, 그리고 제 2단계에서는 중간체인 ${\mu}$-옥소몰리브덴(V) 이합체가 감소되는 반응과 관련된 메카니즘이 제시된다.

• Corrosion Science and Technology
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• 제14권5호
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• pp.232-238
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• 2015

Corrosion is of greatest concern for metallic materials exposed to corrosive seawater or aggressive marine atmospheres. Marine structures and components made of metallic materials incur an initial cost and additional large costs for corrosion control and maintenance. There have been worldwide efforts to minimize marine corrosion and extend service life of the materials. It is believed that various factors are associated with corrosion of marine grade metallic materials, particularly the temperature of the solution affecting the corrosion rate by changing dissolved oxygen solubility and concentrations of chloride. In the present study, the electrochemical characteristics of S355ML steel are investigated to identify corrosion acceleration tendencies with changes in solution temperature under marine environments. It was found that increasing seawater temperature, promoted not only activation of chloride ion transfer, but also the formation of porous $Fe(OH)_3$ or $Fe_2O_3$, leading to the acceleration of corrosion.