• Title/Summary/Keyword: 유경환

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Economic and Environmental Sustainability Assessment of Livestock Manure Gasification for Fuel Gas Production (축분 가스화를 통한 연료가스 생산 공정의 경제적, 환경적 지속가능성 평가)

  • Ji Hong Moon;Kyung Hwan Ryu
    • Applied Chemistry for Engineering
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    • v.34 no.3
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    • pp.291-298
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    • 2023
  • This research evaluates the sustainability of gasifying livestock manure to produce fuel gas from an economic and carbon emission perspective. The entire process, including gasification, fuel gas purification, and pipeline installation to transport the produced fuel gas to the demanding industrial complex, is analyzed for realistic feasibility. The study is conducted using an ASPEN PLUS simulation with experimental data. The results of the economic and CO2 life cycle assessments confirm that the fuel gas produced from livestock manure is competitive with natural gas despite having a lower calorific value. When used as a fuel with a high hydrogen content, the fuel gas emits less CO2 per calorific value, making it more environmentally friendly. A scenario analysis is also performed to determine the expected economics, with price competitiveness being influenced by several factors. Although a significant decrease in natural gas prices could reduce the price competitiveness of the proposed process, it can still be supported by government policies. The cash flow analysis also confirms the economic viability of the process.

Characteristics of Electomigration & Surface Hardness about Tungsten-Carbon-Nitrogen(W-C-N) Related Diffusion Barrier (W-C-N 확산방지막의 전자거동(ElectroMigration) 특성과 표면 강도(Surface Hardness) 특성 연구)

  • Kim, Soo-In;Hwang, Young-Joo;Ham, Dong-Shik;Nho, Jae-Kue;Lee, Jae-Yun;Park, Jun;Ahn, Chan-Goen;Kim, Chang-Seong;Oh, Chan-Woo;Yoo, Kyeng-Hwan;Lee, Chang-Woo
    • Journal of the Korean Vacuum Society
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    • v.18 no.3
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    • pp.203-207
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    • 2009
  • Copper is known as a replacement for aluminum wire which is used for semiconductor. Because specific resistance of Cu ($1.67{\mu}{\Omega}$-cm) is lower than that of Al ($2.66{\mu}{\Omega}$-cm), Cu reduce RC delay time. Although melting point of Cu($1085^{\circ}C$) is higher than melting point of Al, Cu have characteristic to easily react with Silicon(Si) in low temperature, and it isn't good at adhesive strength with Si. For above these reason, research of diffusion barrier to prevent reaction between Cu and Si and to raise adhesive strength is steadily advanced. Our study group have researched on W-C-N (tungsten-carbon-nitrogen) Diffusion barrier for preventing diffusion of Cu through semiconductor. By recent studies, It's reported that W-C-N diffusion barrier can even precent Cu and Si diffusing effectively at high temperature. In this treatise, we vaporized different proportion of N into diffusion barrier to research Cu's Electromigration based on the results and studied surface hardness in the heat process using nano scale indentation system. We gain that diffusion barrier containing nitrogen is more stable for Cu's electromigration and has stronger surface hardness in heat treatment process.

fMRI Study on the Brain Activity Induced by Manual Acpuncture at BL62 (신맥(申脈) 혈위자극이 fMRI상 뇌활성화 변화에 미치는 영향 연구)

  • Rheu, Kyoung-Hwan;Choi, Il-Hwan;Park, Hi-Joon;Lim, Sa-Bi-Na
    • Korean Journal of Acupuncture
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    • v.23 no.2
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    • pp.89-103
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    • 2006
  • Objectives: Recently, the effect of acupuncture has been approved not only in the East but also in the West, so the interest on acupuncture was greatly improved. Especially, functional magnetic resonance imaging(fMRI) was embossed as the study tool for the mechanism of acupuncture noninvasively and many studies on the mechanism of acupuncture using fMRI were carried out. We archived the fMRI study on the brain activity induced by manual acupuncture at BL62(申脈). Methods: The study was the acupuncture at BL62(申脈) and we acquired 9 fMRI results from 6 persons$(age\;20{\sim}30,\;4\;male\;and\;2\;female)$. These studies employed The block design for mapping brain activity and acupuncture was perfomed at BL62(申脈) on the left foot. Results: The brain related motor function was cerebellum, basal ganglia and cerebral cortex and thalamus connected these elements. In the result of this study, the regions of significant activation in the cerebellum was centered on the spinocerebellum in the anterior lobe, so we presumed that this result showed the input of stimulation by the acupuncture on BL62(申脈). But basal ganglia and cerebral cortex showed the regions of significant activation in the left larger than the right and regions of the cerebral cortex was the motor and sensory cortex. Such a result explained that acupuncture at BL62(申脈) could have influence the motor function and acupuncture at left BL62(申脈) could affect the right side through the activation of the left basal ganglia and cerebral cortex. Conclusions: In the theory of crossing needling at collaterals(繆刺論), it the pathogenic factor invaded in the Yang Heel channel(陽?脈) that was one of the eight Extra meridians(奇經八脈), we recognized the disease of the collateral channel and used contralateral BL62(申脈) for treatment of the Yang Heel channel(陽?脈). Moreover the result of this study could bear the construction that acupuncture at the left BL62(申脈) treats the contralateral lesion and this construction is related to the theory of crossing needling at collaterals(繆刺論).

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Effect of saline irrigation used in combination with antimicrobial agents on salivary bacterial counts (생리식염수 세척이 구강 소독제의 타액 내 세균 수의 변화에 미치는 영향)

  • Kim, Dong-Joo;Yu, Kyoung-Hwan;Lim, Hyong-Sub;Lee, Sung-Kyu;Kim, Su-Gwan;Kim, Hak-Kyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.36 no.3
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    • pp.202-205
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    • 2010
  • Introduction: The aim of the present study was to investigate the effect of mechanical irrigation in combination with mouthwash of antimicrobial agents on salivary bacterial counts. Materials and Methods: This study was performed with a randomized study employing a panel of 40 healthy volunteers (20 males and 20 females) between the age of 26 and 32 years. Volunteers were randomly put in one of four treatment groups. In the first group, 0.2 mL of non-stimulatory saliva was collected from every subjective person. Then, saliva was collected after rinsing with chlorhexidine (CHX) for 1 minute. In the second group, non-stimulatory saliva was collected, and then saliva was collected after rinsing with CHX and irrigation with saline. In the third and fourth groups, the same procedures as the first and second groups were performed with povidone iodine (PVI) instead of CHX. All of these samples were cultured for 48 hours aerobically. The reduction rates of colony-forming units (CFU) were calculated for each group. The reduction rate between each group was tested statistically using student t-test. Results: Using CHX in combination with saline irrigation showed a significant decrease of the salivary bacterial CFU when compared with only using CHX.(P<0.01) And using PVI with saline irrigation showed a little decrease of the CFU when compared with only using PVI, but there was no statistical significance.(P>0.01) Conclusion: It was concluded that the CHX or PVI used with saline irrigation made the salivary bacterial counts reduced more than when CHX or PVI was used alone as an oral antiseptic agent.

Comparative study between proportional method and directional method in locating acupoints at forearm (전완부(前腕部) 경혈(經穴) 취혈(取穴)에서 골도분촌법(骨度分寸法)과 일부법(一夫法)의 비교(比較) 연구(硏究))

  • Park, Hi-Joon;Chae, Youn-Byoung;Cha, Wung-Seok;Park, Jong-Bae;Lee, Hye-Jung;Lee, Hyang-Sook;Yin, Chang-Sik;Koh, Hyung-Kyun;Kim, Su-Young;Choe, Il-Hwan;Kim, Kang-Sik;Moon, Jung-Bae;Bae, Ki-Tae;Rheu, Kyoung-Hwan;Yook, Keun-Yung;Jeong, Byeong-Ju;Sohn, In-Chul;Lim, Sabina
    • Korean Journal of Acupuncture
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    • v.21 no.4
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    • pp.31-41
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    • 2004
  • Background : The cun measurement system, an essential and convenient method in locating acupoints, has been widely used in the practice of acupuncture. However, traditional cun measurement has been criticized for its lack of reliability. Objectives : The purposes of this study are to determine if one cun measured by the directional methods have a consistency with that of proportional methods and to investigate which factors are related with these differences, especially in forearm. Methods : The distance between the elbow crease and the wrist crease of forearm was compared to a reference value of one cun obtained by the directional method. In this method, one cun is one third of the distance between index finger and small finger of a subject, measured at proximal interphalangeal joint. In addition, to investigate the factors influencing the differences between these two methods, we measured the height and body weight and calculated body mass index (BMI). Finally we analyzed the factors correlated with these lengths by linear regression test. Results : The results showed that one cun obtained by the directional methods were significantly different from one cun by the proportional methods in forearm. It was demonstrated that the length acquired with the directional method was more correlated with body weight and body mass index, while the length obtained by the proportional method was more correlated with the height. Conclusion : These findings suggest that the directional method is less likely dependable in locating acupoints than the proportional method because the influencing factors are different.

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Plasma G-CSF and GM-CSF Concentrations and Expression of their Receptors on the Granulocyte in Children with Leukocytosis (백혈구 증가증 환아의 혈장내 G-CSF와 GM-CSF의 농도 및 과립구에서의 이들 수용체의 발현)

  • Choi, Won Seok;Ryu, Kyung Hwan;Kim, You Jeong;Kim, So Young;Kim, Hyun Hee;Lee, Wonbae
    • Clinical and Experimental Pediatrics
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    • v.46 no.3
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    • pp.271-276
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    • 2003
  • Purpose : Granulocyte-colony stimulating factor(G-CSF) and granulocyte macrophage-colony stimulating factor(GM-CSF) are principal cytokines in granulopoiesis and their physiologic effects are mediated through binding to specific cell surface receptors. Although it is known that the level of serum G-CSF and GM-CSF, and presentation of the receptors are increased in infectious diseases, there have been no studies to find the correlation between the granulopoiesis and leukocytosis. This study was designed to measure G-CSF and GM-CSF in leukocytosis and in control and to demonstrate the possible pathogenesis of granulopoiesis in leukocytosis using quantitative analysis of G-CSF, GM-CSF and their CSFr. Methods : The plasma levels of G-CSF, GM-CSF of 13 children without leukocytosis and 14 children with leukocytosis were measured. Counts of cell surface G-CSFr and GM-CSFr were measured by combining anti G-CSFr and anti GM-CSFr monoclonal antibodies to their respective receptors by using quantitative flow cytometric assay. Results : There was no significant difference betweeen the plasma concentration of G-CSF and GM-CSF in acute leukocytosis and in the control group. However, levels of G-CSFr in acute leukocytosis decreased significantly compared to the control(P=0.012) and the levels of GM-CSFr in both groups revealed no significant difference. Conclusion : Increase in the number of leukocyte in leukocytosis was mediated by increasing the number of neutrophil, and increased plasma concentration of G-CSF may be the cause of neutrophilia. But GM-CSF did not have any influence on leukocytosis.