• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2007년도 제25회 학술대회발표 논문집
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• pp.65-66
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• 2007

• 한국세라믹학회지
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• 제56권4호
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• pp.365-373
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• 2019

Pond ash is a mixture of mostly coarser fly ash and bottom ash. The recycling rate of pond ash is low because pond ash is mixed with seawater and deposited in ponds. The pond ash is also subjected to natural weathering over a period of time. In this study, we investigated whether pond ash can be used as a raw material of geopolymers, without any purification process or through a minimal purification process. In addition, we investigated whether synthetic basalt made by adding foaming agent to geopolymer or casting it into a mold can show the surface of the natural basalt as it is. The highest 7-day compressive strength in geopolymers from pond ash without purification process was 26 MPa. The highest 7-day compressive strength in geopolymers from pond ash with impurities removed through dry sieve analysis was found to improve to 80 MPa. On the other hand, synthetic basalt made with geopolymer was shown to be more advantageous aesthetically when produced by casting it in a silicone mold rather than by adding a foaming agent. Non-purified pond ash can be made into geopolymers having low strength. Pond ash purified by sieving can, without use of an aggregate, be made into geopolymer having high-strength. Also, it is possible to produce synthetic basalt with the same appearance as natural basalt and sufficient strength for commercialization. This process will contribute to the mass consumption and recycling of pond ash.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.888-893
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• 2016

In this study, the solution plasma process was utilized with the aim of degrading synthetic dyes in water at atmospheric pressure. The experiments were conducted in a batch-type reactor consisting of a symmetric wire-wire electrode configuration with rhodamine B (RhB) as the target synthetic dye. The effects of the plasma treatment time and initial dye concentration on the RhB degradation were investigated by monitoring the change in absorbance of RhB solutions. The RhB solutions turned lighter in color and finally colorless with prolonged plasma treatment time, indicating the destruction of dye molecules. The RhB solutions were found to have degraded, following the first-order kinetic process. However, for high initial RhB concentrations, another kinetic process or factor seems to play a dominant role at the initial degradation stage. The fitted first-order rate constant decreased as the initial concentration increased. This result suggests that the degradation behavior and kinetic process of the RhB solution strongly depends on its initial concentration. The RhB degradation is considered to be due to a combination of factors, including the formation of chemically oxidative species, as well as the emission of intense UV radiation and high-energy electrons from the plasma. We believe that the solution plasma process may prove to be an effective and environment-friendly method for the degradation or remediation of synthetic dye in wastewater.

• 한국축산식품학회지
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• 제41권2호
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• pp.173-184
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• 2021

Clean labeling is emerging as an important issue in the food industry, particularly for meat products that contain many food additives. Among synthetic additives, nitrite is the most important additive in the meat processing industry and is related to the development of cured color and flavor, inhibition of oxidation, and control of microbial growth in processed meat products. As an alternative to synthetic nitrite, preconverted nitrite from natural microorganisms has been investigated, and the applications of pre-converted nitrite have been reported. Natural nitrate sources mainly include fruits and vegetables with high nitrate content. Celery juice or powder form have been used widely in various studies. Many types of commercial starter cultures have been developed. S. carnosus is used as a critical nitrate reducing microorganism and lactic acid bacteria or other Staphylococcus species also were used. Pre-converted nitrite has also been compared with synthetic nitrite and studies have been aimed at improving utilization by exploiting the strengths (positive consumer attitude and decreased residual nitrite content) and limiting the weaknesses (remained carcinogenic risk) of pre-converted nitrite. Moreover, as concerns regarding the use of synthetic nitrites increased, research was conducted to meet consumer demands for the use of natural nitrite from raw materials. In this report, we review and discuss various studies in which synthetic nitrite was replaced with natural materials and evaluate pre-converted nitrite technology as a natural curing approach from a clean label perspective in the manufacturing of processed meat products.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1578-1580
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• 2004

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1288-1288
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• 2001

X-ray powder diffraction (XRD) is utilized for determination of polymorphism in crystalline organic materials. Though convenient to use in a laboratory setting, XRD is not easily adapted to in situ monitoring of synthetic chemical production applications. Near-Infrared spectroscopy (NIR) can be adapted to in situ manufacturing schemes by use of a source/detector probe. Conversely, NIR is unable to conclusively define the existence of polymorphism in crystalline materials. By combining the two techniques, a novel simultaneous NIR/XRD instrument has been developed. During material's analysis, results from XRD allow for defining the polymorphic phase present, and NIR data are collected as a fingerprint for each of the observed polymorphs. These NIR fingerprints will allow for the development of a library, which can be referenced during the use of a NIR probe in manufacturing settings.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.3071-3079
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• 2023

Helium production in the nuclear fuel matrix during irradiation plays a critical role in the design and performance of Gen-IV reactor fuel, as it represents a life-limiting factor for the operation of fuel pins. In this work, a surrogate model for the helium production rate in fast reactor MOX fuels is developed, targeting its inclusion in engineering tools such as fuel performance codes. This surrogate model is based on synthetic datasets obtained via the SCIANTIX burnup module. Such datasets are generated using Latin hypercube sampling to cover the range of input parameters (e.g., fuel initial composition, fission rate density, and irradiation time) and exploiting the low computation requirement of the burnup module itself. The surrogate model is verified against the SCIANTIX burnup module results for helium production with satisfactory performance.

• 응용통계연구
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• 제36권2호
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• pp.141-166
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• 2023

재현자료를 생성하여 배포하는 것은 데이터 공개에 따른 정보 유출의 위험을 방지하는 대표적인 방법이다. 최근 산업에서 데이터의 활용이 중요해진 만큼 한국을 포함한 많은 국가 및 기관에서 재현자료에 관한 연구가 활발히 진행되고 있다. 본 논문에서는 대표적인 재현자료 생성 기법들과 평가 지표들을 소개한다. 전통적인 재현자료 생성 방법인 다중대체와 최근 제시된 인공신경망 기반의 재현자료 생성 방법 등을 활용하여 재현자료를 생성하는 과정을 기술함에 따라 재현자료 생성 방법에 대한 전반적인 이해를 돕는다. 이에 더해 다양한 재현자료 평가 지표를 바탕으로 생성된 재현자료들을 분석 및 비교함에 따라 앞으로의 연구에 대한 방향을 제시하고 그에 대한 토대를 마련하고자 한다.

• 대한기계학회논문집B
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• 제36권8호
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• pp.865-871
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• 2012

최근 고유가와 천연가스 수요 상승에 따른 가격 상승으로 인하여 상대적으로 낮은 가격의 석탄을 이용한 에너지 생산이 주목을 받고 있다. IGCC를 비롯한 석탄가스화 분야는 오래전부터 청정화석연료를 이용한 유망한 기술로 각광받아 왔었다. 본 연구에서는 이러한 석탄가스화 기술을 이용하여 합성천연가스를 생산하는 실제 프로젝트 개발단계에서 석탄가스화기 선정을 위한 기술적 검토를 수행하였다. 합성천연가스 생산에 적합하다고 판단되는 가스화기로써 고정층 슬래그 가스화기, 습식 분류층 가스화기, 건식 분류층 가스화기를 검토 대상으로 선정하여 연구를 진행하였다. 선정된 가스화기별 주요 공정 특징 및 성능에 대하여 검토하였으며, 종합검토내용을 토대로 합성천연가스 생산시 석탄가스화기 선정방향에 대하여 제시하였다.

• 한국광물학회지
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• 제19권2호
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• pp.123-128
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• 2006

딕카이트를 출발물질로 이용하여 이팔면체형 스멕타이트인 바이델라이트를 수열합성한 후, 바이델라이트의 층 내의 금속 양이온을 유기 양이온인 10-Carboxy-n-decyldimethylethyl-ammonium bromide와 교환 반응시켜 유기 [DEACOOH]-바이델라이트를 제조하였다. [DEACOOH]-바이델라이트는 고진공 상태 하에서 건조시킨 후 증류수, 메탄올, 에탄올, 아세톤, 에테르, 아세토니티릴 및 카프로락탐 등 상이한 팽윤용액과 반응시켜 팽윤거동에 대하여 연구하였다. 실험한 결과, 고진공하에서의 층간거리는 15.1 ${\AA}$이었고, 증류수, 메탄올, 에탄올, 아세톤, 에테르, 아세토니티릴, 카프로락탐에서 반응 후에는 각각 19.4, 29.9, 15.9, 16.8, 14.8, 26.5, 14.8 ${\AA}$층간거리가 얻어졌다. 또한 합성 바이델라이트와 자연산 몬모릴로나이트의 층간화합물 및 팽윤거동에 대하여 비교 분석하였다.