• Title/Summary/Keyword: Emission Control

Search Result 1,571, Processing Time 0.026 seconds

Effects of Dietary Supplementation of Lactobacillus reuteri on Performance of Swine, Fecal and Rectumal Microflora and Carcass Grade (유산균(L. reuteri)의 첨가가 돼지의 생산성, 분과 결장내 미생물균총 및 육등급에 미치는 영향)

  • Son, Jang-Ho;Kim, Sang-Ho
    • Korean Journal of Organic Agriculture
    • /
    • v.13 no.2
    • /
    • pp.185-195
    • /
    • 2005
  • Two hundred [(Duroc${\times}$Yorkshire)${\times}$Landrace] pigs were used in a 117-d growth assay (including four growth stages) to determine the effects of dietary supplementation of Lactobacillus reuteri on performance of swine, fecal and rectumal microflora and carcass grade. Pig diet was divided tow types, commercial diet (Control group) and supplemention of 0.1% Lactobacillus reuteri (Treatmental group). There was tend to increased in average daily gain (ADG) and feed efficiency (Feed/gain) in treatmental group than control group during the whole experimental period. The number of Lactobacilius spp. into rectum and feaces and carcass rate tended to increase in treatmental group than control group. Ammonia emission from excreta were decrease by supplemention of 0.1% Lactobacillus reuteri in feed (P<0.05). These results indicated that the dietary Lactobacillus reuteri were effective in performance, increasing of Lactobacilius spp. into rectum and feaces, decreasing ammonia emission from excreta, and it had also effective the carcass rate in swine.

  • PDF

Structural properties of carbon nanotubes: The effect of substrate-biasing (기판 바이어스에 따른 탄소 나노튜브의 구조적 물성)

  • Park, Chang-Kyun;Yun, Sung-Jun;Park, Jin-Seok
    • Proceedings of the KIEE Conference
    • /
    • 2006.10a
    • /
    • pp.36-37
    • /
    • 2006
  • Both negative and positive substrate bias effects on the structural properties and field-emission characteristics are investigated. carbon nanotubes (CNTs) are grown on Ni catalysts employing an inductively-coupled plasma chemical vapor deposition (ICP-CVD) method. Characterization using various techniques, such as field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and Raman spectroscopy, shows that the physical dimension as well as the crystal quality of CNTs grown can be changed and controlled by the application of substrate bias during CNT growth. It is for the first time observed that the prevailing growth mechanism of CNTs, which is either due to tip-driven growth or based-on-catalyst growth, may be influenced by substrate biasing. It is also seen that negative biasing would be more effectively role in the vertical-alignment of CNTs compared to positive biasing. However, the CNTs grown under the positively bias condition display much better electron emission capabilities than those grown under negative bias or without bias. The reasons for all the measured data regarding the structural properties of CNTs are discussed to confirm the correlation with the observed field-emissive properties.

  • PDF

The influence of post-treatment using hydrogen ion bombardment on microstructures and field-emission properties of carbon nanotubes (수소 이온 충돌을 이용한 후처리가 탄소 나노튜브의 구조적 물성 및 전계방출 특성에 미치는 영향)

  • Yun, Sung-Jun;Park, Chang-Kyun;Park, Jin-Seok
    • Proceedings of the KIEE Conference
    • /
    • 2006.07c
    • /
    • pp.1444-1445
    • /
    • 2006
  • Carbon nanotubes (CNTs) are grown on TiN-Coated silicon substrates at $700^{\circ}C$ using an ICP-CVD method. Ni catalysts for CNT growth are formed using an RF magnetron sputtering system. Post-treatment using hydrogen ions has been performed in the ICP reactor by varying the treatment period. The characterization using various techniques, such as FESEM, HRTEM, and Raman spectroscopy, show that the physical dimension as well as the crystal quality of CNTs are changed by the post-treatment process. It is also seen that the hydrogen ion-bombardment may change the surface structure of CNTs, which may lead to produce better electron emission properties. The physical reason for all the measured data obtained are discussed to establish the relationship between the structural property and the electron emission characteristic of CNTs.

  • PDF

Effects of catalyst pretreatment on structural and field emissive properties of carbon nanotubes synthesized by ICP-CVD method (ICP-CVD 방법으로 합성된 탄소 나노튜브의 구조적 물성 및 전계방출 특성에 촉매의 전처리 공정이 미치는 영향)

  • Hong, Seong-Tae;Park, Chang-Kyun;Park, Jin-Seok
    • Proceedings of the KIEE Conference
    • /
    • 2005.07c
    • /
    • pp.1862-1864
    • /
    • 2005
  • Carbon nanotubes [CNTs] are grown on TiN-coated Si substrates at $700^{\circ}C$ by inductively coupled plasma-chemical vapor deposition (ICP-CVD). Pre-treatment of Ni catalysts has been performed using an RF magnetron sputtering system. Structural properties and field-emission characteristics of the CNTs grown are analyzed in terms of the RF power applied and the treatment time used in the pre-treatment process. The characterization using various techniques, such as FE-SEM, AFM, and Raman spectroscopy, show that the physical dimension as well as the crystal quality of CNTs are changed by pre-treatment of Ni catalysts. It is also seen that Ni catalysts with proper grain size and uniform surface roughness may produce much better electron emission. The physical reason for all the measured data obtained are discussed to establish the relationship between the structural property and the electron emission characteristic of CNTs.

  • PDF

A Basic Study on a New Type Particulate Emission Control Means of a Power Station Using a Micro-Gap and a Pulse Discharge (Micro-Airgap Discharge Phenomena) (초미소간격(超微小間隔)과 극단(極端)펄스방전(放電)을 이용(利用)한 미연소탄소립자(未燃燒炭素粒子) 소각제거기술(燒却除去技術) 개발기초연구(開發基礎硏究)(I) (초미소간격(超微小間隔)의 방전현상(放電現象)))

  • Moon, Jae-Duk;Shin, Soo-Youn
    • Proceedings of the KIEE Conference
    • /
    • 1993.07b
    • /
    • pp.605-608
    • /
    • 1993
  • Breakdown characteristics of a small rod-to-rod microairgap has been studied for obtain an optimum breakdown voltage and an airgap spacing to be used as an emission control means by the electrical arc-burning unburnt carbon particulates exhausted from a power station burner. It is found that the breakdown voltage at the rod-to-rod airgap spacing in the rang of $1{\sim}100{\mu}m$ decreased with decrease in the rod-to-rod airgap spacing. And there were no minimum breakdown voltage on a $V_b$-Pd characteristics which is known as the minimum voltage in Paschen's law in air atmosphere. Breakdown voltages of the airgap at the constant airgap spacing were $V_{b-dc}>V_{b-ac}>V_{b-pulse}$, and it was lowest for the pulse voltage applied. As a result, it is found that a pulse power was one of effective power compared with dc or ac to be used as such an unburnt carbon particulate emission control means and the airgap spacing became to several tens ${\mu}m$, then the breakdown voltages were down to several handreds voltages.

  • PDF

The impact of corrosion on marine vapour recovery systems by VOC generated from ships

  • Choi, Yoo Youl;Lee, Seok Hee;Park, Jae-Cheul;Choi, Doo Jin;Yoon, Young Soo
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.11 no.1
    • /
    • pp.52-58
    • /
    • 2019
  • Marine emissions of Volatile Organic Compounds (VOCs) have received much attention because the International Maritime Organization (IMO) requires the installation of vapour emission control systems for the loading of crude oils or petroleum products onto ships. It was recently recognised that significant corrosion occurs inside these vapour emission control systems, which can cause severe clogging issues. In this study, we analysed the chemical composition of drain water sampled from currently operating systems to investigate the primary causes of corrosion in vapour recovery systems. Immersion and electrochemical tests were conducted under simulated conditions with various real drain water samples, and the impact of corrosion on the marine vapour recovery system was carefully investigated. Moreover, corrosion tests on alternative materials were conducted to begin identifying appropriate substitutes. Thermodynamic calculations showed the effects of environmental factors on the production of condensed sulphuric acid from VOC gas. A model of sulphuric acid formation and accumulation by the characteristics of VOC from crude oil and flue gas is suggested.

A Characteristics of Hg, Pb, As and Se Emitted from Small and Medium Size Waste Incinerator Stacks (중.소형 폐기물 소각시설에서 배출되는 수은, 납, 비소, 셀렌 배출특성)

  • Lee, Han-Kook;Moon, Bu-Shik;Lee, Dong-Hoon
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.27 no.11
    • /
    • pp.1205-1214
    • /
    • 2005
  • This study was carried out to investigate the emission characteristics of volatile metals(Hg, As, Se) and semi volatile metals such as Pb from small and medium size municipal solid waste incinerators(MSWIs). The concentrations of Hg, Pb, As and Se in emission gas from small size waste incinerators were higher than those of medium size waste incinerators. This is probably due to less air pollutant control devices and high emission gas temperature of the small size waste incinerators relative to the medium size waste incinerators. Emission gas temperature from small and medium size waste incinerators were divided into 2 groups. The first group was about $100^{\circ}C$ and the second roup in the range of $400{\sim}700^{\circ}C$. The concentrations of emission gas at the second group were Hg $70.43\;{\mu}g/Sm^3$, Pb $0.94\;{\mu}g/Sm^3$, As $9.83\;{\mu}g/Sm^3$ and Se $5.05\;{\mu}g/Sm^3$. The concentrations of Hg, Pb, As and Se at the first group were lower than those found at the second group. Besides, the removal efficiencies of Hg in medium size waste incinerators were $55.2{\sim}95.9%$. Emission gas temperature reduction from waste heat boiler(WHB) contribute to control of Hg. Based on above results, we postulate that the temperature of flue gas should play a very important role in volatile metal control in small and medium size MSWIs. In order to improve the volatile metals removal efficiency, the temperature of cooling system must be controlled and the air pollution control device should be operated properly.

Decreases Nitrous Oxide Emission and Increase Soil Carbon via Carbonized Biomass Application of Orchard Soil (과수원 토양의 탄화물 시용에 따른 아산화질소 발생량 감소와 토양탄소 증가효과)

  • Lee, Sun-il;Kim, Gun-yeob;Choi, Eun-jung;Lee, Jong-sik;Jung, Hyun-cheol
    • Korean Journal of Environmental Agriculture
    • /
    • v.36 no.2
    • /
    • pp.73-79
    • /
    • 2017
  • BACKGROUND: Carbonized biomass is a carbon-rich solid product obtained by the pyrolysis of biomass. It has been suggested to mitigate climate change through increased carbon storage and reduction of greenhouse gas emission. The objective of this study was to evaluate carbon dioxide ($CO_2$) and nitrous oxide ($N_2O$) emissions from soil after carbonized biomass addition. METHODS AND RESULTS: The carbonized biomass was made from a pyrolyzer, which a reactor was operated about $400{\sim}500^{\circ}C$ for 5 hours. The treatments were consisted of a control without input of carbonized biomass and two levels of carbonized biomass inputs as 6.06 Mg/ha for CB-1 and 12.12 Mg/ha for CB-2. Emissions of $CO_2$ and $N_2O$ from orchard soil were determined using closed chamber for 13 weeks at $25^{\circ}C$ of incubation temperature. It was shown that the cumulative $CO_2$ were $209.4g\;CO_2/m^2$ for CB-1, $206.4g\;CO_2/m^2$ for CB-2 and $214.5g\;CO_2/m^2$ for the control after experimental periods. The cumulative $CO_2$ emission was similar in carbonized biomass input treatment compared to the control. It was appeared that cumulative $N_2O$ emissions were $4,478mg\;N_2O/m^2$ for control, $3,227mg\;N_2O/m^2$ for CB-1 and$ 2,324mg\;N_2O/m^2$ for CB-2 at the end of experiment. Cumulative $N_2O$ emission contents significantly decreased with increasing the carbonized biomass input. CONCLUSION: Consequently the carbonized biomass from byproducts such as pear branch residue could suppress the soil $N_2O$ emission. The results fromthe study imply that carbonized biomass can be utilized to reduce greenhouse gas emission from the orchard field.

Development of Cleanroom Garment Design in Semiconductor Industrial Environment (반도체 산업환경에서의 방진복 디자인의 개발)

  • 이윤정;정찬주;정재은
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.26 no.2
    • /
    • pp.337-348
    • /
    • 2002
  • Based upon literature survey and questionnaire survey, this research tries to develop four new Cleanroom Garment in semiconductor industrial environment. The designs emphasize to minimize workers disconmfort so that they can not only cover human body fully but also reduce dust as much as possible during work hour in clean room. The new designs characteristics and results from both function test and dust emission test are as follows: 1. In order to reduce dust-emission, we develop new designs with hood, kimono sleeve, and back zipper. The designs with hood face positive test results in term of motion suitability and dust-omission. The design with seam in front, in particular, is effective to control dust-emission. 2. For the purpose of reducing dust-emission, we also emphasize to minimize ease of dust-proof wear, with reference to previous research and clothing experiment. The experiment participants report that the new wears are not so comfortable as existing ones, but they accept the new wears positive as effective in reducing dust-emission owing to reduced ease of Cleanroom Garment and sleeves. 3. A1so to reduce dust-emission in inner wear, we put inner wear in both Cleanroom Garments and inner wear, resulting to remove discomfort of wearers when changing clothes and of tight waist due to inner-trousers. 4. We develop new designs with elastic bands in both waist through the side lines and with velcro only at the back side. To remove twist in front contributes to reduce emission arising out of friction, also to free the appearance minding woman workers from worrying about exposed stomach. The new designs need to be accepted as a valuable alternative of Cleanroom Garment, in that they are highly effective to reduce dust-emission, which is the most important factor in the wear, in spite of some drawbacks in terms of motion-suitability, ease and appearance as shown in wearing test.

Emission Characteristics of 0.7' Monochrome MOSFET-Controlled Field Emission Display in a High Vacuum Chamber

  • Lee, Jong-Duk;Oh, Chang-Woo;Kim, Il-Hwan;Park, Jae-Woo;Park, Byung-Gook
    • Journal of Information Display
    • /
    • v.2 no.3
    • /
    • pp.66-71
    • /
    • 2001
  • MCFEDs (MOSFET-Contoolled Field Emission Displays) were fabricated to evaluate the validity of MCFEA for display application. The electrical properties of FEAs (Field Emitter Arrays), HVMOSFETs (High-Voltage MOSFETs), and MCFEAs (MOSFET-Controlled Field Emitter Arrays) were measured. The extraction gate voltage of the FEAs to obtain the anode current of 10 nA/tip was around 71 V. The breakdown voltages of the HVMOSFETs were above 81 V for all the samples. The I-V characteristics of the MCFEAs showed that the emission currents of the FEAs were well controlled depending on the control gate voltages of the HVMOSFETs. To avoid the harmful effects during the packaging process, the performance of the MCFEDs was evaluated in a high vacuum chamber. The emission images of the MCFEDs were controlled through very-through operation. From the comparison with a conventional FED, it was proven that the poor uniformity of FED could be improved through the integration with HVMOSFET.

  • PDF