• Title/Summary/Keyword: Mild

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Experimental Study for Oxygen Methane MILD Combustion in a Laboratory Scale Furnace (Laboratory Scale 연소로를 적용한 산소 메탄 MILD 연소에 대한 실험적 연구)

  • Lee, Pil Hyong;Hwang, Sang Soon
    • Journal of the Korean Society of Combustion
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    • v.21 no.4
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    • pp.6-15
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    • 2016
  • The oxygen fuel MILD (Moderate or Intense Low-oxygen Dilution) combustion has been considered as one of the promising combustion technology for flame stability, high thermal efficiency, low emissions and improved productivity. In this paper, the effect of oxygen and fuel injection condition on formation of MILD combustion was analyzed using lab scale oxygen fuel MILD combustion furnace. The results show that the flame mode was changed from a diffusion flame mode to a split flame mode via a MILD combustion flame mode with increasing the oxygen flow rate. A high degree of temperature uniformity was achieved using optimized combination of fuel and oxygen injection configuration without the need for external oxygen preheating. In particular, the MILD combustion flame was found to be very stable and constant flame temperature region at 7 KW heating rate and oxygen flow rate 75-80 l/min.

Low NOx MILD Combustion for Sawdust Fuel (폐목 톱밥 연료의 저NOx MILD연소)

  • Shim, Sung-Hoon
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.153-156
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    • 2008
  • MILD combustion has been successfully applied to gaseous fuels and few commercial systems are now in operation. Extending MILD combustion applicability to solid fuel of sawdust is the focus of the present work. The MILD combustion furnace at the University of Adelaide in Australia was used in this study. A measurement of $O_2$ and CO emissions have been carried out in parallel with consideration of NOx emission and compared in each modes of conventional natural gas combustion, natural gas MILD combustion, NOx emission in natural gas MILD combustion mode can be reduced to 20% in comparison with conventional combustion. Emission in cases of air carrying sawdust combustion and $CO_2$ carrying sawdust combustion were also compared. Air and $CO_2$ were sued as a carry gas for the sawdust. It was found that MILD conditions are possible for sawdust particles of less than $355{\mu}m$ without additional air pre-heating. It was also found that when using $CO_2$ as the carry gas the flame inside the furnace was not visible anymore and that NOx emission dropped to less than two folds.

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The characteristics of temperature distribution, NOx and CO formation in a MILD combustor with the variation of equivalence ratio (당량비 변화에 따른 MILD 연소로의 온도 분포 및 NOx, CO 생성 특성)

  • Ha, Ji-Soo;Yu, Sang-Yeol;Sim, Sung-Hoon;Kim, Tae-Kwon
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.4
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    • pp.485-490
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    • 2010
  • MILD (Moderate and Intense Low Oxygen Dilution) combustion is a technique which is able to reduce NOx formation and to uniform temperature distribution in the furnace by recirculating the exhaust gas to the fresh air and fuel. This study focuses on finding optimal condition of MILD combustor by changing equivalence ratio with fuel and air flow. The present experiment employs six thermocouple sensors in the furnace, and two concentration probes of NOx and CO at the exhaust exit pipe respectively. The MILD combustion phenomena have been observed at the condition of equivalent ratios of 0.71~0.73, and the temperature uniformity, NOx and CO concentration are also examined at the MILD combustion condition.

A Study on Multi-Sensor System for Detection of Chronic Mild Stress (만성스트레스 검출을 위한 멀티 센서시스템 연구)

  • Lee, Ji-Hyeoung;Kim, Kung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.6
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    • pp.1131-1135
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    • 2010
  • The development of modern civilization result from the abundance of material. Yet modern people live with chronic mild stress. Excessive chronic mild stress leads to various diseases. From the risk of the disease in order to protect our bodies need to manage chronic mild stress. The purpose of this study is to inspection the effectiveness of detecting in chronic mild stress using the Multi-sensor system. The Multi-sensor system is designed that can be measure three kinds of vital signals of chronic mild stress for the detection. First Photoplethysmogram(PPG), second Electro Dermal Activity(EDA), third Skin Temperature(SKT). The ages and occupations exposed to chronic mild stress, people often use out of this system was applied to dairy products(Pen). In addition, vital signals that occur when the variety of noise was used to remove the accelerometer. Chronic mild stress by the analysis of measured vital signals from Multi-sensor system to the measurement information to a PC to a wireless transmission(Bluetooth). In this study, using Multi-sensor system writing conditions and a variety of situations in the movement to measure vital signals and measurement results verified the accuracy and reliability. Through this measure chronic mild stress in everyday life and managing to maintain will help more healthy lifestyle.

Electroplating of Nickel on Nickel Titanate Modified Mild Steel Surface

  • Beenakumari, K.S.
    • Journal of Electrochemical Science and Technology
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    • v.4 no.2
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    • pp.57-60
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    • 2013
  • Nickel is a good electrocatalytic metal and nickel electrodes find many applications in different electrochemical fields. The nickel plated electrodes were prepared by electro-deposition technique on mild steel surface modified with in-situ deposition of nickel titanate. The SEM images shows that the nickel plating on nickel titanate modified mild steel shows better adherence than the nickel plating on bare mild steel surfaces. The extent of polarization of the nickel plating on mild steel with nickel titanate was lower than that of nickel plating on mild steel. The incorporation of nickel titanate on mild steel surface before nickel plating enhances physical, chemical and electrochemical properties of the plating film.

MILD Combustion Technology for Recycled Fuel (재생연료의 MILD연소기술)

  • Shim, Sung Hoon;Jeong, Sang Hyun;Lee, Sang Sup
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.205.2-205.2
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    • 2010
  • Optimum operation conditions of low-NOx MILD combustion for gaseous and solid fuels have been investigated by experimental and computer simulation. Loop reactor type MILD combustor without air pre-heater has been used in the present work. The results show that the balance of injection velocities of fuel and surrounding air is major factor for maintaining MILD combustion mode. Temperature difference between lower and upper part can be reduced less than 20 degree of Celsius. It was found that NOx emission in MILD combustion also can be remarkably reduced to more than 85% in comparison with conventional premixed combustion, and reduced to more than 50% in case of nitrogen and carbon dioxide carrying dried waste water sludge and pulverized coal in comparison with the same of air carrying. It was also found that carbon monoxide emission increase was not appeared at the time of changeover to MILD combustion mode from premixed or air carrying combustion at optimum operation condition.

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Understanding and Application of MILD combustion (마일드연소의 이해와 응용)

  • Kim, Nam Il
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.281-282
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    • 2014
  • Recently, studies on Mild combustion have grown in many combustion application fields in the international combustion society. Compared with international activities in this field, domestic study in Korea has not been activated yet. This brief review aims to explain some essences of fundamental physics of Mild combustion and to introduce some recent application techniques of them. Fundamental physics of Mild combustion has been usually broken down into three aspects [1]; physical, thermodynamic, and chemical aspects. A major portion of Mild combustion physics is related to HiTAC (High Temperature Air Combustion) or HiCOT (High Temperature Combustion Technology). Although definition of Mild combustion is easily accepted among combustion engineers, combustion control in Mild combustion may be difficult without understanding essential physics of it. To encourage the research in this field, some representative cases will be introduced, and related essential techniques will be explained.

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MILD Combustion Characteristics with Inlet Air Velocity in a Conical Combustor (원추형 연소로에서 공기 유속에 따른 MILD 연소특성)

  • Kim, Tae-Kwon;Ha, Ji-Soo;Jo, A-Ron
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.6
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    • pp.774-779
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    • 2012
  • MILD (Moderate and Intense Low Oxygen Dilution) combustion is a technology that uses the recirculation of combustion gas to increase thermal efficiency not only by keeping down the concentration of Nitric Oxides and temperature but also by uniformizing the internal temperature of the combustion furnace. This study is a trial to obtain MILD combustion characteristics by adjusting the equivalence ratio with the air flow rate in the conical combustor while keeping the fuel flow rate and measuring the exhaust gas of the combustion furnace.

Neurocognitive Function Differentiation from the Effect of Psychopathologic Symptoms in the Disability Evaluation of Patients with Mild Traumatic Brain Injury

  • Kim, Jin-Sung;Kim, Oh-Lyong;Koo, Bon-Hoon;Kim, Min-Su;Kim, Soon-Sub;Cheon, Eun-Jin
    • Journal of Korean Neurosurgical Society
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    • v.54 no.5
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    • pp.390-398
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    • 2013
  • Objective : We determined whether the relationship between the neuropsychological performance of patients with mild traumatic brain injury (TBI) and their psychopathological characteristics measured by disability evaluation are interrelated. In addition, we assessed which psychopathological variable was most influential on neuropsychological performance via statistical clustering of the same characteristics of mild TBI. Methods : A total of 219 disability evaluation participants with mild brain injury were selected. All participants were classified into three groups, based on their psychopathological characteristics, via a two-step cluster analysis using validity and clinical scales from the Minnesota Multiphasic Personality Inventory (MMPI) and Symptom Checklist-90-revised (SCL-90-R). The Korean Wechsler Adult Intelligence Scale (K-WAIS), Korean Memory Assessment Scale (K-MAS) and the Korean Boston Naming Test (K-BNT) were used to evaluate the neurocognitive functions of mild TBI patients. Results : Over a quarter (26.9%) experienced severe psychopathological symptoms and 43.4% experienced mild or moderate psychopathological symptoms, and all of the mild TBI patients showed a significant relationship between neurocognitive functions and subjective and/or objective psychopathic symptoms, but the degree of this relationship was moderate. Variances of neurocognitive function were explained by neurotic and psychotic symptoms, but the role of these factors were different to each other and participants did not show intelligence and other cognitive domain decrement except for global memory abilities compared to the non-psychopathology group. Conclusion : Certain patients with mild TBI showed psychopathological symptoms, but these were not directly related to cognitive decrement. Psychopathology and cognitive decrement are discrete aspects in patients with mild TBI. Furthermore, the neurotic symptoms of mild TBI patients made positive complements to decrements or impairments of neurocognitive functions, but the psychotic symptoms had a negative effect on neurocognitive functions.

An Investigation on the Tetrahydropyrimidine Derivatives as Acid Corrosion Inhibitors for Mild Steel

  • Chitra, S.;Gayathri, N.;Parameswari, K.
    • Corrosion Science and Technology
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    • v.8 no.2
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    • pp.45-52
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    • 2009
  • The corrosive behavior of mild steel in 0.05 M to 10 M $H_2SO_4$ solutions containing different concentrations of tetrahydropyrimidine derivatives (THPM) was investigated using weight loss method, gasometric technique, electrochemical studies which include AC - impedance and potentiodynamic polarization method, atomic absorption studies and synergistic effect. The results obtained reveal that THPM derivatives is an efficient mixed type inhibitor but slightly anodic and it is more effective in reducing corrosion of mild steel in $H_2SO_4$ media. The adsorption of the inhibitor on the mild steel surface obeys the Langmuir adsorption isotherm. The thermodynamic parameters of adsorption reveal a strong interaction and spontaneous adsorption of THPM on the mild steel surface. The influence of temperature and inhibitor concentration on the corrosion of mild steel has also been investigated.