• Title/Summary/Keyword: Repeated forming Process

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Enumeration and Activity of Methanogenic Microorganisms of th Anaerobic Digestion Process

  • Lee, Kwang-Ho
    • Korean Journal of Hydrosciences
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    • v.2
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    • pp.115-126
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    • 1991
  • The anaerobic digester with sludge from sewage treatment plant was operated in the laboratory for two year to investigate the enumeration and activity of methanogenic microorganisms. In this experimental study, the effects of HRT on the degradation characteristics of organic materials and on the number of methanogenic bacteria produced were investigated. By making the media with the repeated wxperiment, the number and activity of methanogenic bacteria were measured. The increase of the removal rate of organic acid in the digester was oberved at HRT of 2 days. The total number of methane forming bacteria estimated by the MPN method showed 2.3 $\times$ $ at HRT of 3 days, 7$\times$$ of 5 days and 7.9$\times$$ $/ml of 10 days. The optimum incubation time for measuring the number of methanogenic bacteria was found as more than four weeks. The PMA revealed 161ml CH$/l day at HRT of 10 days and the PUA 290mg COD/l day. At the incubation time 4.3 days, the maximum value of CH$ *59.1%) was found. At this time, $ was found as 15.3% and $ 25.6%.

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Forging Analysis of Upper Swash Plate for Unmanned Helicopter (무인 헬기용 상부 스와시 플레이트의 단조공정해석)

  • Kim, K.S.;Lee, O.Y.;Kong, J.H.;Yeo, H.T.;Hur, K.D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.347-349
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    • 2009
  • Unmanned helicopters are needed in various fields such as monitoring system, agriculture and forest fire. Swash plate is a essential part for exact driving of unmanned helicopter. And it is usually produced by machining. In this research, hot forging process of upper swash plate has been studied to improve proof stress against repeated loading of the product. In the forming analysis, design parameters such as effective stress, effective strain and distribution of damage have been considered in the hot forging.

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A Study on Forming 'Body Schema' for Role Creating (역할 창조를 위한 '몸틀(body schema)' 형성 연구)

  • Song, Hyo-sook
    • Journal of Korean Theatre Studies Association
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    • no.52
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    • pp.319-357
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    • 2014
  • Formation of 'body schema' is the start for actor to create role and becomes the root and the foundation of existing as a role on the stage. For this, an actor needs to form 'scheme of role' with escaping from own 'body schema.' 'Schema of role' is formed by acquiring through synthesizing daily basic actions, namely, walking, standing, sitting, hand stretching, bending, and touching. The body schema, which was made with simple and usual actions, has fundamental significance in a sense of becoming the body in which the past traces in a role are habituated while energy as a role flows. As for the process of forming body schema, an actor first needs to obtain the visualized materials like photo, magazine, picture and image available for seeing a role specifically and clearly based on what analyzed a character. An actor needs to have three-dimensional image available for always recalling it in the head during acting. To do this, image data available for fundamentally capturing routine actions along with body structure are still more useful. Next, the body schema is formed by interaction with environment. Thus, there is a need of passing through the two-time process of forming body schema. Firstly, the body schema is made on routine actions in a role as physical condition of a role in actor's own everyday life. Secondly, the body schema is made on routine actions available for moving efficiently and economically in line with the environment of performance. A theatrical stage is the temporal space of rhythm and rule different from routine space. What forms body schema immediately in the second phase without body schema in the first phase ultimately becomes what exists as actor's own body, not the body of a role. The body schema, which was formed as the second process, is what truly has identity as a role in the ontological aspect, comes to experience the oppositional force in muscle, a qualitative change in energy, and emotional agitation in the physical aspect, and experiences perception, thinking, volition, and even consciousness with the entire body in the cognitive dimension. Thus, the formation of body schema can be known to be just a method of changing even spiritual and emotional layer. Body schema cannot be made if there is no process of embodiment and habit. Embodiment and habit are not simply the repeated, empty and mechanical action in the body. But, habit itself has very important meanings for forming body schema for role creating. First, habit allows the body itself to learn and understand a meaning. Second, habit relies upon environment, thereby allowing an actor of making the habituated body schema to recognize environment. Third, habit makes the mind. The habituated body schema is just the mind and the ego of a person who possesses the body schema. Fourth, habit comes to experience the expansion in energy and the expansion in existence. It may be experienced through interrelation among actor's body, tool, and environment. Fifth, habit makes identity of the body. Hence, this just becomes what secures identity of a role. These implications of habit are the formation of body schema, which is maintained with the body of being remembered firmly through being closely connected with the process of neural adaptation. Finally, it sought for possibility of practice as one method of forming body schema for role creating through Deleuze's '-becoming' theory. As 'actual animal-becoming' is real '-becoming' of forming structural transformation in the physical dimension, it meets with what the formation of body schema pursues actuality and reality. This was explained with a concept as saying of 'all '-becoming' molecular' by Deleuze/Guattari. 'Animal of having imitated animal's characteristic- becoming' is formed by which the body schema relies upon environment. In this way, relationship among the body, tool and environment has influence even upon a change in consciousness, thinking, and emotion, thereby being able to be useful for forming body schema in a sense of possibly experiencing ultimately expansion in role, namely, expansion in existence.

Influence of Super Carburization on the Roller Pitting Fatigue Life of 0.16C-0.60Si-2.00Cr-0.34Mo Steel (0.16C-0.60Si-2.00Cr-0.34Mo강의 피팅강도에 미치는 고탄소 침탄의 영향)

  • Shin, Jung-Ho;Lee, Woon-Jae;Kim, Young-Pyo;Ko, In-Yong
    • Korean Journal of Metals and Materials
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    • v.50 no.7
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    • pp.517-522
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    • 2012
  • In this study, a super carburizing treatment was applied to improve roller pitting fatigue life. It produced excellent properties of surface hardness and temper softening resistance by forming precipitation of fine and spherodized carbides on a tempered marstensite matrix through the repeated process of carburization and diffusion after high temperature carburizing step 1. The cycle II performed two times carburizing/diffusion cycle (process) after super carburization at $1,000^{\circ}C$ had fine and spherodized carbides to subsurface $200{\mu}m$. In this case, the carbide was $(Fe,Cr)_3C$ and there was not any massive carbides. In the case of Cycle II, the roller pitting fatigue life had a 6.15 million cycles. It was improved 48% compared to normal gas carburizing treatment.

A Study on the Law Enforcement of Korea Coast Guard against the Illegal Chinese Fishing Vessels (불법조업 중국어선에 대한 해양경찰의 단속에 관한 고찰)

  • Lim, Chae-Hyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.1
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    • pp.49-58
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    • 2014
  • The illegal fishery act committed Chinese fishing vessels have not been stopped and Korea Coast Guard(KCG) has been injured or killed by chinese fishing forces, even though the Korean Government has been trying to control the illegal fishery and repeated violent act committed by Chinese fishing vessels in our Exclusive Economic Zone. Moreover, some problems in relation to the control process of KCG to suppress the illegal foreign fishing vessels has been exposed in spite of extensive efforts of Korean Government. Improper law enforcement of KCG in relation to foreign fishing vessels would cause international dispute between related states, although the control process to the illegal fishing vessels at sea is in a way of due law enforcement process forming a State's power. To this end, this paper examines the problems raised during the control process which is including the visit and inspection of illegal Chinese fishing vessels and law enforcement process exercised by KCG and presents practical solutions through analyzing the related materials, professional's opinion and recent cases.

Analysis of Microstructural Refinement for Inconel 706 during Hot Forging Process through Reheating and Strain (Inconel 706의 열간단조 공정 중 재가열과 변형양에 따른 결정립 미세화에 대한 분석)

  • S. G. Seong;H. J. Kang;Y. S. Lee;S. Y. Lee;U. J. Lee;H. I. Jae;J. H. Shin;E. Y. Yoon
    • Transactions of Materials Processing
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    • v.32 no.5
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    • pp.239-246
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    • 2023
  • To reduce the forming load due to the temperature drop, during the hot forging process, a reheating hot forging process design is required that to repeat heating and forging. However, if the critical strain required for recrystallization is not induced during forging and grain growth becomes dominant due to the reduction in dislocation density due to repeated heating, the mechanical properties may deteriorate. Therefore, in this study, Inconel 706 alloy was applied, and the grain refinement behavior was comparatively analyzed according to the number of reheating times and effective strain during reheating hot forging process. Reheating was carried out with a total compression rate of 40% up to 4 times. The Inconel 706 compression test specimens heated once showed finer grains as the effective strain increased due to the dynamic recrystallization phenomenon. However, as the number of heating increases, grain refinement was observed even in a low effective strain distribution of 0.43 due to static recrystallization during reheating. Moreover, grain growth occurs at a relatively low effective strain of 0.43 when the number of reheating is four or more. Therefore, it was effective to apply an effective strain of 0.43 or more during hot forging to Inconel 706 in order to induce crystallization through grain refinement and improve the properties of forged products. In addition, we could notice that up to three reheating times condition was appropriate to prevent grain growth and maintain fine grain size.

Ex-situ Remediation of a Contaminated Soil of Fe Abandoned Mine using Organic Acid Extractants (유기산 추출에 의한 철 폐광산 오염토양의 복원)

  • 정의덕;강신원;백우현
    • Journal of Environmental Science International
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    • v.9 no.1
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    • pp.43-47
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    • 2000
  • A study on the remediation of heavily for ion contaminated soils from abandoned iron mine was carried out, using ex-situ extraction process. Also, oxalic acid as a complex agent was evaluated as a function of concentration, reaction time and mixing ratio of washing agent in order to evaluate Fe removability of the soil contaminated from the abandoned iron mine. Oxalic acid showed a better extraction performance than 0.1N-HCl, i.e., the concentrations of Fe ion extracted from the abandoned mine for the former at uncontrolled pH and the latter were 1,750 ppm and 1,079 ppm, respectively. The optimum washing condition of oxalic acid was in the ratio of 1:5 and 1:10 between soil and acid solution during l hr reaction. The total concentrations of Fe ion by oxalic acid and EDTA at three repeated extraction, were 4,554 ppm and 864 ppm, respectively. The recovery of Fe ions from washing solution was achieved, forming hydroxide precipitation and metal sulfide under excess of calcium hydroxide and sodium sulfide. In addition, the amounted of sodium sulfide and calcium hydroxide for the optimal revovery of Fe were 15g/$\ell$ and 5g/$\ell$ from the oxalic acid complexes, respectively.

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Laser Transmission Welding of Flexible Substrates and Evaluation of the Mechanical Properties (플렉서블 기판의 레이저 투과 용접 및 기계적 특성 평가)

  • Ko, Myeong-Jun;Sohn, Minjeong;Kim, Min-Su;Na, Jeehoo;Ju, Byeong-Kwon;Park, Young-Bae;Lee, Tae-Ik
    • Journal of the Microelectronics and Packaging Society
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    • v.29 no.2
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    • pp.113-119
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    • 2022
  • In order to improve the mechanical reliability of next-generation electronic devices including flexible, wearable devices, a high level of mechanical reliability is required at various flexible joints. Organic adhesive materials such as epoxy for bonding existing polymer substrates inevitably have an increase in the thickness of the joint and involve problems of thermodynamic damage due to repeated deformation and high temperature hardening. Therefore, it is required to develop a low-temperature bonding process to minimize the thickness of the joint and prevent thermal damage for flexible bonding. This study developed flexible laser transmission welding (f-LTW) that allows bonding of flexible substrates with flexibility, robustness, and low thermal damage. Carbon nanotube (CNT) is thin-film coated on a flexible substrate to reduce the thickness of the joint, and a local melt bonding process on the surface of a polymer substrate by heating a CNT dispersion beam laser has been developed. The laser process conditions were constructed to minimize the thermal damage of the substrate and the mechanism of forming a CNT junction with the polymer substrate. In addition, lap shear adhesion test, peel test, and repeated bending experiment were conducted to evaluate the strength and flexibility of the flexible bonding joint.

Effect of Setting Temperatures and Time on the Gelation Properties (Suwari and Modori Phenomena) of Surimi from Mechanically Deboned Chicken Meat

  • Lee, Sung Ki;Min, Byung Jin
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.12
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    • pp.1758-1763
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    • 2004
  • This study was carried out to investigate gel forming and degradation properties (suwari and modori phenomena) of chicken surimi from mechanically deboned chicken meat (MDCM) at various setting temperatures and time. Chicken surimi was manufactured by a continuous process including chopping of MDCM, washing with 5% NaCl solution or pure water, standing, straining and centrifuging etc. Total process of washing for the MDCM from chopping to centrifuging was repeated over 3 cycles. Gel from prepared surimi were formed at $90^{\circ}C$ for 30 min after various setting treatments. The textural properties of gels were measured at the temperature ranges of low (10$^{\circ}C$), medium (25$^{\circ}C$ and $30^{\circ}C$) and high (45 to 70$^{\circ}C$). The compressive force (CF), hardness and fracturability of surimi gel at 10$^{\circ}C$ increased as setting time increased, and showed the highest value at 30 h of setting time. The CF and hardness of chicken surimi gel at 25$^{\circ}C$ and 30$^{\circ}C$ showed the highest values at 10 h of setting time. Most of gel strengths including CF, and texture profile analysis (TPA) values showed the highest levels in the range 47.5 to 52.5$^{\circ}C$ (p<0.05). The gel strength at 60$^{\circ}C$ increased slightly at 30 min, but then continued to decrease with longer setting times. There was no increase of gel strength at $70^{\circ}C$, but only a continuous decrease over setting time. In conclusion, suwari (gel setting) and modori (gel degradation) phenomena occur during the gel formation of surimi from MDCM. The temperature range in chicken surimi was 47.5 to 52.5$^{\circ}C$ for suwari and 60 to 70$^{\circ}C$ for modori.

Scale Formation by Electrode Reactions in Capacitive Deionization and its Effects on Desalination Performance (축전식 탈염에서 전극반응에 의한 스케일 생성과 탈염성능에 미치는 영향)

  • Choi, Jae-Hwan;Kang, Hyun-Soo
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.74-79
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    • 2016
  • The effects of scale formation of hardness material caused by electrode reactions on the desalination performance of the membrane capacitive deionization (MCDI) were investigated. During the repeated adsorption and desorption process for the influent containing $Ca^{2+}$ ion, changes in effluent concentration and cell potential with respect to the number of adsorption were analyzed. It was found that $OH^-$ generation at the cathode was initiated at about 0.8 V or more of cell potential. In addition, the scale of $Ca(OH)_2$ was formed on the surface of cathode carbon electrode by combining adsorbed $Ca^{2+}$ ions and $OH^-$ ions generated from electrode reaction. As the scale was forming, the electrical resistance of carbon electrode was increasing, which resulted in the decrease of the adsorption amount. In the case of the operation at 1.5 V cell potential, the adsorption was reduced to 58% of the initial adsorption amount due to the scale formation.