• Title/Summary/Keyword: Specific Strength

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Comparative Study on Applicable Consolidants for Archival Objects of Copper Alloy (동합금 행정박물에 적용 가능한 표면강화처리제 비교 연구)

  • Park, Chang-Su;Cho, Hyun-Kyung;Cho, Nam-Chul;Kang, Dai-Ill
    • Journal of Conservation Science
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    • v.28 no.1
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    • pp.53-62
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    • 2012
  • The archival objects are tangible evidence related to the public service. They are unique and offer information representing the specific events, time or person. The archival objects as modern cultural heritage do not have the guideline to classify, manage and conserve them. Especially, it is difficult to apply general conservation process for burial artifacts, because there are few study example of conservation for metal archival objects and they have complex administrative value. We tried to find suitable material and application method for consolidation of copper alloy archival object. We choose three kinds of wax and acrylic resin for burial artifacts and had done comparative analysis of their characterizations following kinds and coating methods. As a result of evaluation by several surface analysis such as optical microscope, measuring film thickness, adhesive strength, contact angle and yellowing test, acrylic resin can use to archival objects of copper alloy, effectively but the method of heating after dip-coating with Wax B used before can get best effect of consolidation.

Tracking Interdisciplinary Relationships between Scientific Researches in Energy Fields using Bibliometic Analysis (과학기술논문을 통한 에너지 연구 분야의 다학제 동태 추적분석)

  • Kang, Jong-Seok;Chung, Hyun-Sang;Lee, Il-Hyung
    • Journal of Korea Technology Innovation Society
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    • v.13 no.4
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    • pp.680-699
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    • 2010
  • In this paper, we attempted to analysis and track dynamic properties of the interdisciplinary relationship between scientific research areas in energy field using bibliometric analysis. We created network maps with SCs (subject categories) defined from $WoS^{\circledR}$ (Web of Science, Thomson Scientific ISI, Philadelphia, USA) using co-occurrence analysis method in order to identify overall disciplines directly linked with energy fields and investigate the change of interaction between SCs as a function of time. From the results of this study, thermodynamics, fuels, chemistry/chemical engineering, and electrochemistry have differentiated into more specific disciplines while the strength of interaction with energy field gradually has increased. Meanwhile, "nuclear physics" was developed to "nuclear science & technology" toward applicable target sector and also the interaction of "environmental science" with "energy generation area" among various energy disciplines recently showed the radical increase as compared with the values of 4 years ago. Finally, through combinative reviews of today's energy policy established by South Korea government, this study will give a help for keeping up with national energy agenda meeting the diverse characteristics of academic disciplines of energy field. In addition, our results support that the use of such network analysis based on bibliometric analysis to discern shifts in academic R&D strategies and target sectors.

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Isolation and Characterization of a Diesel-Degrading Bacterium, Gordonia sp. SD8 (디젤 분해 세균 Gordonia sp. SD8 분리 및 특성)

  • Hong, Sun-Hwa;Kim, Ji-Young;Cho, Kyung-Suk
    • Microbiology and Biotechnology Letters
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    • v.38 no.3
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    • pp.335-339
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    • 2010
  • A diesel-degrading bacterium, Gordonia sp. SD8, was isolated from soil contaminated with petroleum, and its diesel degradation was characterized in a soil as well as a liquid culture system. SD8 could grow in the mineral salt medium supplemented with diesel as a sole carbon and energy source. The maximum specific growth rate ($0.67{\pm}0.05\;d^{-1}$) and diesel degradation rate ($1,727{\pm}145$ mg-TPH $L^{-1}\;d^{-1}$) of SD8 showed at 20,000 mg-TPH $L^{-1}$ and $30^{\circ}C$, and then this bacterium could degrade high strength of diesel of 40,000 mg-TPH $L^{-1}$. The residual diesel concentration in the inoculated soil with SD8 was 3,724 mg-TPH kg-dry $soil^{-1}$ after 17 days, whereas the diesel concentration in the non-inoculated soil was $8,150{\pm}755$ mg-TPH kg-dry $soil^{-1}$. These results indicate that Gordonia sp. SD8 can serve as a promising microbial resource for the bioremediaion of contaminated soil with petroleum hydrocarbons including diesel.

The Effects of Dynamic Functional Electrical Stimulation With Treadmill Gait Training on Functional Ability, Balance Confidence and Gait in Chronic Stroke Patients

  • Cho, Young-Ki;Ahn, Jun-Su;Park, Yong-Wan;Do, Jung-Wha;Lee, Nam-Hyun;Kwon, Oh-Yun
    • Physical Therapy Korea
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    • v.21 no.4
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    • pp.23-33
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    • 2014
  • The aim of this study was to evaluate the effects of walking on a treadmill while using dynamic functional electrical stimulation (Dynamic FES) on functional ability and gait in chronic stroke patients. This was a prospective, randomized controlled study. Twelve patients with chronic stroke (>24 months) who were under grade 3 in dorsiflexor strength with manual muscle test were included and randomized into intervention (Dynamic FES) ($n_1$=7) and control (FES) ($n_2$=5). Both the Dynamic FES group and FES group were given a neuromuscular development treatment. The Dynamic FES group has implemented a total of 60 minutes of exercise treatment and gait training with Dynamic FES application. The FES group, with the addition of applying FES while sitting, has also implemented a total of 90 minutes of gait training on treadmill after the exercise treatment. Both two groups accomplished the program, twice a week, for a total of 24 times in a 12-week period. Exercise treatment, gait training on treadmill, and both Dynamic FES and FES were implemented for 30 minutes each. Korean version activities-specific balance confidence scale (K-ABC) was measured to determine self-efficacy in balance function. Timed up and go (TUG) test was performed to evaluate the physical performance. K-ABC, TUG, Berg balance scale (BBS), modified physical performance test (mPPT) and G-walk were evaluated at baseline and at 12 weeks. After 12 weeks, statistically significant differences (p<.05) were apparent in the Dynamic FES group in the changes in K-ABC and BBS. mPPT, TUG, gait speed, stride length and stance phase duration (%) were compared with the FES group. K-ABC had higher correlation to BBS, along with mPPT to TUG. Our results suggest that walking with Dynamic FES in chronic stroke patients may be beneficial for improving their balance confidence, functional ability and gait.

Effects on Quality Characteristics of Extruded Meat Analog by Addition of Tuna Sawdust (참치 톱밥의 첨가가 압출성형 인조육의 품질 특성에 미치는 영향)

  • Cho, Sung Young;Ryu, Gi-Hyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.4
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    • pp.465-472
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    • 2017
  • In this study, tuna sawdust was added to extruded meat analog in order to develop a meat analog with high quality. Addition of tuna sawdust has merit for utilizing a byproduct from poultry processing. Physicochemical characteristics were examined through the extrusion cooking process. The basic mixture of sample mixed with 65% deffated soy flour 25% isolated soy protein, and 10% corn starch was setup as the raw material. Three kinds of samples were made in total by addition of 15% and 30% tuna sawdust to this mixture. The extrusion process had a screw speed of 250 rpm, die temperature of $140^{\circ}C$, and moisture content of 50%. As addition of tuna sawdust increased, breaking strength and density decreased, specific length increased, and integrity and water holding capacity decreased. Likewise, nitrogen solubility index and protein digestibility decreased as addition of tuna sawdust increased. DPPH radical scavenging activity increased as addition of tuna sawdust addition, whereas it decreased as storage period increased to 30 or 60 days. The value of rancidity decreased as addition of tuna sawdust increased. However, 60 days later, radical scavenging activity increased more or less, and a significant difference was detected 150 days later. In conclusion, addition of tuna sawdust increased soft texture, and nutrition of the basic mixture sample. The process promoting functionality such as improvement of antioxidant function was confirmed through this study.

A Study on the Engineering Characteristics of Power Plant Coal Ash (화력발전소 부산물인 석탄회의 공학적 특성에 관한 연구)

  • Kuk, Kilkeun;Kim, Hyeyang;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.5
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    • pp.25-34
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    • 2010
  • In this study characteristics for reclaimed ash was studied to enlarge the usage of reclaimed ash which is reaching to 72 million ton producted from whole thermal power plants in South Korea. Fly ash and bottom ash are reclaimed separately at some of thermal power plants. However, typically bottom ash and fly ash are mixed when they are buried at most of the thermal power plant, as a result the engineering characteristics of ponded ash are not investigated properly. In order to investigate the engineering characteristics of the ponded ash, laboratory tests were performed with ponded ash and fly ash from youngheung and samcheonpo thermal power plants. Specific gravity, unit weight, and grain size analysis test were fulfilled to evaluate the physical characteristics and triaxial permeability test, direct shear test, unconfined compressive strength test, compaction test were performed to evaluate the mechanical characteristics. And also engineering characteristics of coal ash from anthracite and Bituminous thermal power plants were compared and studied respectively. As a result of the study, it was confirmed that using coal ash from Bituminous thermal power plants can be effective in the place where lightweight materials are required and using coal ash from anthracite thermal power plants can be effective as backfill material which require higher permeability. Finally, it was confirmed that fly ash from youngheung thermal power plants which has the lowest permeability among the tested material is suitable for a field requiring impermeable material.

Analytical Assessment of Blast Damage of 270,000-kL LNG Storage Outer Tank According to Explosive Charges (270,000 kL급 LNG 저장 탱크 외조의 폭발량에 따른 손상도 해석적 평가)

  • Kim, Jang-Ho Jay;Choi, Seung-Jai;Choi, Ji-Hun;Kim, Tae-Kyun;Lee, Tae-Hee
    • Journal of the Korea Concrete Institute
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    • v.28 no.6
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    • pp.685-693
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    • 2016
  • The outer tank of a liquefied natural gas (LNG) storage tank is a longitudinally and meridionally pre-stressed concrete (PSC) wall structure. Because of the current trend of constructing larger LNG storage tanks, the pre-stressing forces required to increase wall strength must be significantly increased. Because of the increase in tank sizes and pre-stressing forces, an extreme loading scenario such as a bomb blast or an airplane crash needs to be investigated. Therefore, in this study, the blast resistance performance of LNG storage tanks was analyzed by conducting a blast simulation to investigate the safety of larger LNG storage tanks. Test data validation for a blast simulation of reinforced concrete panels was performed using a specific FEM code, LS-DYNA, prior to a full-scale blast simulation of the outer tank of a 270,000-kL LNG storage tank. Another objective of this study was to evaluate the safety and serviceability of an LNG storage tank with respect to varying amounts of explosive charge. The results of this study can be used as basic data for the design and safety evaluation of PSC LNG storage tanks.

The effect of applying u-health system on metabolic syndrome management of elderly (U-health system 활용이 남녀노인의 대사증후군 관리에 미치는 영향)

  • Chung, Jin-Wook;Sung, Soon-Chang
    • Journal of Digital Convergence
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    • v.11 no.11
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    • pp.553-560
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    • 2013
  • The purpose of this study was to examine the effect of u-health system on metabolic syndrome risk factor, body composition, and fitness in male and female elderly. Subjects were 46 elderly(24 men and 22 women) with metabolic syndrome. They were divided into u-health group and home exercise group. Blood pressure, blood profile, body composition, and fitness were measured before and after the intervention. As a results, blood glucose and waist circumference showed significant interaction in both men and women, respectively. In body composition, weight, muscle mass, fat mass, %body fat, BMI showed significant interaction whereas only muscle mass showed significant differences in women. In fitness, there were interaction shown in 3m up and go, functional reach, and gait speed in men. In women sit to stand, 6min walk, and grip strength showed significant interaction. In conclusion, u-health system seems to be the effective method in terms of checking regularly. However, easier and more simple system for elderly and specific direction for exercise should be added.

A study on the discriminant analysis of node deployment based on cable type Wi-Fi in indoor (케이블형 Wi-Fi 기반 실내 공간의 노드 배치 판별 분석에 관한 연구)

  • Zin, Hyeon-Cheol;Kim, Won-Yeol;Kim, Jong-Chan;Kim, Yoon-Sik;Seo, Dong-Hoan
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.836-841
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    • 2016
  • An indoor positioning system using Wi-Fi is essential to produce a radio map that combines the indoor space of two or more dimensions, the information of node positions, and etc. in processing for constructing the radio map, the measurement of the received signal strength indicator(RSSI) and the confirmation of node placement information counsume substantial time. Especially, when the installed wireless environment is changed or a new space is created, easy installation of the node and fast indoor radio mapping are needed to provide indoor location-based services. In this paper, to reduce the time consumption, we propose an algorithm to distinguish the straight and curve lines of a corridor section by RSSI visualization and Sobel filter-based edge detection that enable accurate node deployment and space analysis using cable-type Wi-Fi node installed at a 3 m interval. Because the cable type Wi-Fi is connected by a same power line, it has an advantage that the installation order of nodes at regular intervals could be confirmed accurately. To be able to analyze specific sections in space based on this advantage, the distribution of the signal was confirmed and analyzed by Sobel filter based edge detection and total RSSI distribution(TRD) computation through a visualization process based on the measured RSSI. As a result to compare the raw data with the performance of the proposed algorithm, the signal intensity of proposed algorithm is improved by 13.73 % in the curve section. Besides, the characteristics of the straight and the curve line were enhanced as the signal intensity of the straight line decreased by an average of 34.16 %.

Study on the Development and Property of Epoxy Putty with Excellent Low Shrinkage and Cutting Force Using Mercaptan Type and Diamine Type (Mercaptan계와 Diamine계를 이용한 저수축·절삭력이 우수한 Epoxy Putty의 개발 및 물성에 관한 연구)

  • Oh, Seung-Jun;Wi, Koang-Chul
    • Journal of Adhesion and Interface
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    • v.16 no.4
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    • pp.137-145
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    • 2015
  • This study aimed to develop epoxy putty as a multi-purpose connection and restoration material that can be used for material-specific restoration work such as metal, wood, ceramics, earthenware and stone artifacts by replacing synthetic resins currently being used for preservation treatment of cultural assets. Existing synthetic resins have the issue of cutting force resulting from high strength, deflection resulting from long hardening time, contaminating the surface of artifacts through staining on tools or gloves and need for re-treatment resulting from material discoloration. Accordingly, paste type restoration material most widely being used in the field of cultural assets preservation treatment was selected and examined the property to select it as an object of comparison. Based on such process, epoxy putty was developed according to the kind of agent, hardener and filler. For the purpose of solving the issues of existing material and allowing the epoxy putty developed to have similar property, property experiments were conducted by selecting agents and hardeners with different characteristics and conditions. The study findings showed that both kinds are paste type that improved work convenience and deflection issue as a result of their work time of within 5~10 minutes that are about 3~10 times shorter than that of existing material. In regards to wear rate for increasing cutting force, it improved by about 3 times, thereby allowing easy molding. For the purpose of improving the issue of surface contamination that occurs during work process, talc and micro-ballon were added as filler to reduce the issue of stickiness and staining on hand. Furthermore, a multi-purpose restoration material with low shrinkage, low discoloration and high cutting force was developed with excellent coloring, lightweight and cutting force features.