• Title/Summary/Keyword: Excess oxygen

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Study of Advanced Control for Chemical Process Using the Commercial Package PCTP Based on Model Predictive Control Algorithm (모델예측제어기반 상용 Package PCTP를 이용한 화학공정의 제어 고도화 연구)

  • Park, Jun-Ho;Park, Ho-Cheol;Lee, Moon-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.11
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    • pp.1128-1136
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    • 2007
  • This paper presents an application study of a model predictive control based commercial package PCTP to real chemical processes. The first case study concerns a product purity control of a splitter process which distillates styrene from undesired component ethyl-benzene produced from ethyl-benzene dehydrogenation reaction. The second case study is about a temperature control of ethyl-benzene dehydrogenation reactor and an excess oxygen control of the fired heater. Optimum control structure for MPC application is developed for each case study. The application results show a significant improvement in control performance and stability.

Effects of Partial Substitution of W for Ti in Titanium Dioxide

  • Lee, Eun-Seok
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.2
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    • pp.68-71
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    • 2011
  • [ $Ti_{1-x}W_xO_{2-y}$ ]solid solutions with compositions of x = 0.01(TW-1), x = 0.02(TW-2), x = 0.03(TW-3) and x = 0.04(TW-4) were prepared at 1,073 K in air under atmospheric pressure. All the solutions exhibited tetragonal symmetries. Nonstoichiometric chemical formulas have been obtained from oxidation-reduction titration and the partial substitution of $W^{6+}$ ions mainly caused the formation of $Ti^{3+}$ ion, rather than oxygen excess. Resistivities of the samples were highly dependent on humidity. The increase of the W amount resulted in an increase of $Ti^{3+}$ content, decrease of resistivity values and finally degradation of photocatalytic activities.

A Study on Bu一ja(<附子>, Oh-du<烏頭>) Toxicosis (부자(附子)오두(烏頭) 중독증(中毒症)에 관한 소고(小考))

  • Na, Chang-Su;Yun, Yeo-Chung
    • The Journal of Korean Medicine
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    • v.16 no.1 s.29
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    • pp.451-467
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    • 1995
  • In order to study on Bu-ja(Oh-du) toxicosis, the outhor investigated many documents. The results obtained were as follows: 1. Toxicosis of Bu-ja(Oh-du) arised mainly from carelessness in use. 2. In the symptoms of Bu-ja(Oh-du), Heart System(心系) symptom often came out. 3. The general and local paralysis, falling of blood pressure in Heart System(心系) symptom : vertigo, cramp in Liver System(肝系) symptom : nausea, vomiting in Spleen System (脾系) symptom : difficulty of breathing in Lung System(肺系) symptom : wasting disease in Kidney System (腎系) symptom frequently originated from toxicosis of Bu-ja(Oh-du). 4. In the detoification method, there are atropin injection, carrying out a gastric lavage, and supplying a liquid medicine from the western medicine : taking ginger-licorice root decoction, taking mung beans thick decoction and getting vomited with soaked cinnamon from the oriental medicine. And also keeping warm and oxygen inhalation were used to counteract poison. 5. A pregnant woman, heat of excess type(實熱), yang sydrome(陽證 )must not be taken Bu-ja(Oh-du).

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Temperature Distributions inside a Space Heater for Greenhouse (I) - Temperature Characteristics with Heating Oil - (시설원예용 온풍난방기내의 온도분포에 관한 연구 (I) - 난방유 사용시 온도특성 -)

  • 서정덕;김종진;최규성;신창식;노수영
    • Journal of Biosystems Engineering
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    • v.24 no.4
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    • pp.335-342
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    • 1999
  • Air and flue gas temperature distributions in the space heater for greenhouse were measured to develop a thermal design technology for the space heater. Also, the characteristics of the fan supplying air to the space heater were investigated. The temperature of the flue gas inside the flue gas tube was linearly decreased as the lenght of than those of the flue gas with the oxygen concentration of 8.25% at the last exit of the second flue gas tube. Thus, the operating efficiency of the space heater could be increased with low air ratio decreased exhausting gas temperature and saved the energy consumption with decreased excess air flow. The temperature of the air supplied by fan was increased slowly around the first flue gas tube, meanwhile, increased sharply around the second flue gas tube due to large LMTD (Logarithmic Mean Temperature Difference) at the first flue gas tube than which of the second flue gas tube.

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Cellular and Molecular Pathways of Ischemic Neuronal Death

  • Won, Seok-Joon;Kim, Doo-Yeon;Gwag, Byoung-Joo
    • BMB Reports
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    • v.35 no.1
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    • pp.67-86
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    • 2002
  • Three routes have been identified triggering neuronal death under physiological and pathological conditions. Excess activation of ionotropic glutamate receptors cause influx and accumulation of $Ca^{2+}$ and $Na^+$ that result in rapid swelling and subsequent neuronal death within a few hours. The second route is caused by oxidative stress due to accumulation of reactive oxygen and nitrogen species. Apoptosis or programmed cell death that often occurs during developmental process has been coined as additional route to pathological neuronal death in the mature nervous system. Evidence is being accumulated that excitotoxicity, oxidative stress, and apoptosis propagate through distinctive and mutually exclusive signal transduction pathway and contribute to neuronal loss following hypoxic-ischemic brain injury. Thus, the therapeutic intervention of hypoxic-ischemic neuronal injury should be aimed to prevent excitotoxicity, oxidative stress, and apoptosis in a concerted way.

Effect of Ball-Milling on the Superconducting Properties of C and C-Based Compound Doped $MgB_2$ (탄소 및 탄소화합물이 도핑된 $MgB_2$ 초전도체의 볼밀링 효과)

  • Ahn, Jung-Ho;Jang, Min-Kyu;Oh, Sang-Jun
    • Progress in Superconductivity
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    • v.10 no.1
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    • pp.17-22
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    • 2008
  • We have examined the effect of ball-milling on the superconducting properties of $MgB_2$ doped with C. The ball-milling of pre-reacted $MgB_2$ powder was carried out in dry or wet state using C or diethylenetriamine ($C_{4}H_{13}N_3$) as additives. The diethylenetriamine, whose chemical formula contains no oxygen, was chosen to avoid an excess oxidation during doping. The superconducting transition temperature (Tc) of the ball-milled or doped $MgB_2$ powders was only slightly smaller than that of undoped $MgB_2$. The critical current density (Jc) of the highly ball-milled $MgB_2$ was higher than that of C-doped $MgB_2$. The addition of diethylenetriamine was detrimental to Jc, although Tc was almost unchanged.

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Optimizing Oily Wastewater Treatment Via Wet Peroxide Oxidation Using Response Surface Methodology

  • Shi, Jianzhong;Wang, Xiuqing;Wang, Xiaoyin
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.80-84
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    • 2014
  • The process of petroleum involves in a large amount of oily wastewater that contains high levels of chemical oxygen demand (COD) and toxic compounds. So they must be treated before their discharge into the receptor medium. In this paper, wet peroxide oxidation (WPO) was adopted to treat the oily wastewater. Central composite design, an experimental design for response surface methodology (RSM), was used to create a set of 31 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the COD removals. The experimental results show that WPO could effectively reduce COD by 96.8% at the optimum conditions of temperature $290^{\circ}C$, $H_2O_2$ excess (HE) 0.8, the initial concentration of oily wastewater 3855 mg/L and reaction time 9 min. RSM could be effectively adopted to optimize the operating multifactors in complex WPO process.

5.1: Control of Electrical Characteristics of Solution Processed TFTs Depending on InGaZnO Composition Variation

  • Kim, Gun-Hee;Jeong, Woong-Hee;Ahn, Byung-Du;Shin, Hyun-Soo;Kim, Hyun-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.524-526
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    • 2009
  • The effects of In and Ga contents on characteristics of InGaZnO (IGZO) films grown by a sol-gel method and their thin film transistors (TFTs) have been investigated. Excess In incorporation into IGZO enhances the field effect mobilities of the TFTs due to the increase in conducting path ways, and decreases the grain size and the surface roughness of the films because more $InO_2^-$ ions induce cubic stacking faults with IGZO. Ga incorporation into results in decrease in carrier concentration of films and off-current of TFTs since Ga ion forms stronger chemical bonds with oxygen than Zn and In ions, acting as a carrier killer.

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Emerging perspectives on mitochondrial dysfunction and inflammation in Alzheimer's disease

  • Yoo, Seung-Min;Park, Jisu;Kim, Seo-Hyun;Jung, Yong-Keun
    • BMB Reports
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    • v.53 no.1
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    • pp.35-46
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    • 2020
  • Despite enduring diverse insults, mitochondria maintain normal functions through mitochondrial quality control. However, the failure of mitochondrial quality control resulting from excess damage and mechanical defects causes mitochondrial dysfunction, leading to various human diseases. Recent studies have reported that mitochondrial defects are found in Alzheimer's disease (AD) and worsen AD symptoms. In AD pathogenesis, mitochondrial dysfunction-driven generation of reactive oxygen species (ROS) and their contribution to neuronal damage has been widely studied. In contrast, studies on mitochondrial dysfunction-associated inflammatory responses have been relatively scarce. Moreover, ROS produced upon failure of mitochondrial quality control may be linked to the inflammatory response and influence the progression of AD. Thus, this review will focus on inflammatory pathways that are associated with and initiated through defective mitochondria and will summarize recent progress on the role of mitochondria-mediated inflammation in AD. We will also discuss how reducing mitochondrial dysfunction-mediated inflammation could affect AD.

Pilot Scale Experiments on the Oxidation of $TiCl_4$ ($TiCl_4$의 산화반응에 대한 파이롯트 규모 실험)

  • 박균영;이익형;양현수
    • Journal of the Korean Ceramic Society
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    • v.27 no.6
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    • pp.817-823
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    • 1990
  • Pilot-scale experiments on the oxidation of TiCl4 to produce TiO2 were carried out in a verical reactor of 20cm in inside diameter and 140cm in length ; LPG burning was used as a heating means to maintain the reaciton temperature. The effects of reaction temperature and excess oxygen content on the conversion of TiCl4 and on the particle size of produced TiO2 were investigated. The ranges of operating conditions varied were 900 to TiO2 was 0.45-0.57${\mu}{\textrm}{m}$, TiCl4 conversion was 82-96%, the rutile content was 33-57% and the contents of impurities were 0.03% of Fe, 0.03% of SiO2 and 62ppm of Cl. These experimental results were compared with those of other investigators.

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