• 한국구조물진단유지관리공학회 논문집
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• 제21권5호
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• pp.12-20
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• 2017

본 연구는 규산나트륨($Na_2SiO_3$)으로 활성화된 고유동 대량치환슬래그 시멘트의 기초특성에 관한 연구이다. 고로슬래그 미분말(GGBFS)은 보통포틀랜드 시멘트(OPC)의 40%에서 80%까지 질량치환하고 칼슘설포알루미네이트(CSA)는 2.5%와 5.0% 치환하였다. 규산나트륨($Na_2SiO_3$)은 전체 결합재(OPC+GGBFS+CSA) 질량의 2%와 4% 추가하였다. 모든 배합의 물-결합재 비(w/b)는 0.35이다. 본 연구에서는 미니슬럼프, V-funnel, 응결시간, 압축강도와 건조수축을 측정하였다. 실험결과 유동화제 양, V-funnel, 응결시간과 건조수축은 CSA와 $Na_2SiO_3$가 증가함에 따라 감소하였다. 그러나 압축강도는 CSA와 $Na_2SiO_3$가 증가함에 따라 증가하였다. 이러한 원인 중 하나는 CSA와 $Na_2SiO_3$가 GGBFS의 활성화를 촉진하였기 때문이다. 최고의 성능을 나타낸 배합은 CSA 5.0% + $Na_2SiO_3$ 4%를 혼합한 시험체이다.

• 공업화학
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• 제17권1호
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• pp.16-21
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• 2006

본 연구에서는 폴리아닐린(PANI)을 제조하여 큰 분자량의 유기산인 10-camphor sulfonic acid (CSA) 또는 dodecylbenzene sulfonic acid (DBSA)로 도핑시키고, polyethylene oxide (PEO)와 함께 블렌딩하여 전기방사 용액을 제조하였다. 제조된 용액을 전기방사하여 섬유형태로 만든 후, TGA와 전기화학 장치(cyclic voltammetry; CV)로 열적, 전기적 성질을 CSA 또는 DBSA로 도핑된 PANI의 함량에 따라 비교, 분석하였다. 본 실험 결과, PANI-CSA와 PANI-DBSA의 함량이 증가함에 따라 열분해 개시온도는 감소하지만 열안정성 지수와 적분 열분해 진행온도가 증가하는 것으로 보아 열안정성은 증가하는 것으로 판단된다. 또한, 전기전도도는 PANI-CSA와 PANI-DBSA의 함량이 증가함에 따라 증가하였으나 30% 이상이 되면 전도도가 일정해지는 것으로 나타났다. 순환전류젼압 곡선 결과, PANI/CSA는 PANI-DBSA 보다 피크가 좀 더 명확해지며, 전류밀도가 크게 나타났다. 이는 PANI/CSA가 약간 더 높은 전기전도도와 전하가 이동하기 쉬운 모폴로지를 가지고 있기 때문인 것으로 판단된다.

• 한국구조물진단유지관리공학회 논문집
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• 제21권6호
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• pp.74-82
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• 2017

본 연구는 고로슬래그 미분말(GGBFS), 플라이 애시(FA) 그리고 칼슘설포알리미네이트(CSA)를 혼합한 활성화된 삼성분계 시멘트의 강도와 건조수축에 대한 연구결과이다. 활성화된 삼성분계 시멘트(ATBC) 모르타르의 물-결합재 비는 0.4이다. GGBFS의 치환율은 100%, 80%, 70% 그리고 60%이며, FA는 10%, 20%, 30% 그리고 40%, CSA는 0%, 10%, 20% 그리고 30% 치환비율로 설정하였다. 혼화제는 폴리카르폭실계를 사용하였다. 활성화제는 결합제 질량에 대해 10% 수산화나트륨(NaOH) + 10% 규산나트륨($Na_2SiO_3$)을 사용하였다. 실험은 미니 슬럼프, 응결시간, V-funnel, 물흡수율, 압축강도 그리고 건조수축을 측정하였다. 실험결과 모든 배합에서 혼화제의 양, V-funnel 그리고 압축강도는 CSA 양이 증가함에 따라 증가하였다. 또한 응결시간, 물 흡수율과 건조수축은 CSA가 증가함에 따라 감소하였다. 강도증가와 건조수축 감소의 가장 큰 원인 중 하나는 CSA와 활성화제에 의한 GGBFS의 수화반응 촉진 때문이다. CSA의 혼합양은 활성화된 삼성분계 시멘트의 강도 증가와 건조수축 감소에 중요 영향요인이다.

• Journal of Radiation Protection and Research
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• 제35권2호
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• pp.81-84
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• 2010

A CSA(Charge Sensitive Amplifier) was designed and fabricated for application in a radiation detection system based on a semiconductor detector such as Si, SiC, CdZnTe and etc.. A fabricated hybrid.type CSA was evaluated by comparison with a commercially available CSA. A comparison was performed by using calculation of ENC (Equivalent Noise Charge) and by using energy resolutions of fabricated radiation detectors based on Si. In energy resolution comparison, a fabricated CSA showed almost the same performance compared with a commercial one. In this study, feasibility of a fabricated CSA was discussed.

• 시멘트 심포지엄
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• 32호
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• pp.103-106
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• 2005

유해 중금속을 다량 함유하고 있는 산업폐기물의 고화 처리에 사용되는 칼슘설포알루미네이트(4CaO$\cdot$$3Al_2O_3$$\cdot$$SO_4$이후부터 CSA로 기입) 의 제조를 위해 철강부산물인 압연 슬러지를 활용하여 그 특성에 대해 조사하였다. 본 연구에서는 철강 부산물인 압연슬러지 외에 석회석 미분물, 인산부산 석고를 혼합하여 칼슘알루미네이트상을 합성하였다. 합성 결과 소성온도 1250$^{\circ}C$에서부터 CSA가 합성되었고, 이와 함께 칼슘실리케이트 (2CaO$\cdot$$SiO_2$)와 칼슘알루미노페라이트(4CaO$\cdot$$Al_2O_3$$\cdot$$Fe_2O_3$)도 함께 합성되었다. CSA 합성에 미치는 중금속 영향을 관찰한 결과 원료의 중금속이 CSA 합성 온도를 낮추는 효과가 있는 것으로 나타났다. CSA를 이용한 철강산업 폐기물의 중금속 고용 처리 연구에서도 본 실험에서 합성된 CSA가 폐기물의 중금속 고화 처리에 효과가 있는 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.310-313
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• 2000

Polyaniline Emeraldine Base (PANI EB) polymerized by chemical oxidative polymerization was doped with Camphorsulfonic Acid(CSA). Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) solutions were solved in organic solvents and sonificated at the room temperature for different solvents in PANI-CSA ES solution and sonification time. PANI-CSA ES solutions was coated on PET films using bar coater. 1-Step oxidatively-polymerized Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) was solved in m-cresol:chloroform 1:1 co-solvents and their solution was bar-coated on PET film. The surface resistivities of these coated films were measured, The surface resistivity of PANI-CSA ES solution in m-cresol:chloroform 1:1 co-solvent system was 5${\times}$10$^2$$\Omega$/$\square$.

• Structural Engineering and Mechanics
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• 제77권6호
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• pp.779-795
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• 2021

In the recent decades, various optimization algorithms have been considered for the optimization of structures. In this research, a new enhanced algorithm is used for the size and topology optimization of truss structures. This algorithm, which is obtained from the combination of Crow Search Algorithm (CSA) and the Cellular Automata (CA) method, is called CA-CSA method. In the first iteration of the CA-CSA method, some of the best designs of the crow's memory are first selected and then located in the cells of CA. Then, a random cell is selected from CA, and the best design is chosen from the selected cell and its neighborhood; it is considered as a "local superior design" (LSD). In the optimization process, the LSD design is used to modify the CSA method. Numerical examples show that the CA-CSA method is more effective than CSA in the size and topology optimization of the truss structures.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.53-54
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• 2023

In recent decades, climate change has become an issue of global importance. The calcium sulfoaluminate (CSA) cement emits lower CO₂ than the Portland cements while manufacturing. However, ettringite, which is a main hydration product of CSA cement, starts dehydrating at a temperature above 100℃, hence it may limit the CSA cement for high temperature application. Recently, an early carbonation curing of cement-based material has been extensively studied in terms of carbon neutralization. The carbonation curing of CSA cement has a potential to transform the AFt and AFm phases into calcium carbonate, and the transformation of unstable hydrates to stable hydrates can increase the resistance to elevated temperature. This review study summarizes and discusses the carbonation curing effect of CSA cement and the thermal stability of CSA cement exposed to elevated temperatures.

• 한국유기농업학회지
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• 제9권1호
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• pp.1-16
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• 2001

With increasing global concern that intensively synthetic-chemical based farming systems accelerated the decline in environmental quality, the sustainability of modem agriculture became the subject of great concern. It is well known that the movement of Community Supported Agriculture(CSA) has been contributed significantly to the development of organic agriculture in USA and Japan. It was supposed that CSA could be one of the best way to promote the movement of organic agriculture since there is little reliability on the organically grown food by consumer. In this paper it was focussed to study the movement of CSA in USA and Europe in order to provide an idea for establishment and movement of CSA in Korea to support the organic agriculture. In a CSA system, the farmer grows food for a group of shareholders who pledge to buy a portion of the farm's crop that season. This arrangement gives growers up-front cash to finance their operation and higher prices for produce, since the middleman has been eliminated. For most shareholder for CSA saving money is a secondary consideration, but fresh safe products and environmentally sound farming system. People become shareholder of CSA since they expect an organic farming which can ; \circled1protect the environment, minimize pollution, promote health, \circled2replenish and maintain long-term soil fertility by providing optimal conditions for soil biological activity, \circled3maintain diversity within the farming system and its surroundings and protect plant and wildlife habit, \circled4recycle materials and resources to the greatest extent possible within the farm and its surrounding community, \circled5maintain the integrity of organic food and processed products through each step of the process from planting to consumption, \circled6develop and adopt new technologies with consideration for their long range social and ecological impact. In all CSAs, the farmer develops a crop plan and a budget, which details costs for a growing season, including fair wages for the farmers. Experienced Information on increasing shareholder retention, the future of CSA, and getting started such as ideas for ongoing marketing, printed materials that set realistic expectations, working members, production, pick-up and delivery, setting prices, and receiving feedback were also briefly introduced.

• Journal of Acupuncture Research
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• 제19권5호
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• pp.199-208
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• 2002

Objective : This study was undertaken to determine if Carthami Semen Aquacupunc- ture(CSA) exerts protective effect against alterations in membrane transport function rabbits with mercury chloride(HG)-induced acute renal failure. Methods : The administration of Hg at a subcutaneous single dose of 10 mg/kg caused a reduction in GFR and an increase in fractional Na excretion, indicating generation of acute renal failure. When CSA were given for 7 days prior to Hg administration, such changes were significantly attenuated. The fractional excretion of glucose and phosphate was increased in rabbits treated with Hg alone. Results : The increase in rabbits treated with Hg following CSA are significantly lower than that in animals treated with Hg alone. Uptakes of glucose and phosphate in purified isolated brush-border membrane and Na-K-ATPase activity in microsomal fraction were inhibited in rabbits treated with Hg alone. Such changes were prevented by CSA. Uptakes of organic ions, PAH and TEA, in renal cortical slices were inhibited by the administration of Hg, which was prevented by CSA. Exposure of renal cortical slices to Hg in vitro caused an increased LDH release and lipid peroxidation, which was significantly prevented by CSA extract. Conclusions : These results indicate that the administration of Hg causes impairment in reabsorption of solutes in the proximal tubule via the generation of reactive oxygen species. CSA provides the protection against the impairment in proximal reabsorption, and its effect may be resulted from its antioxidant effect.