• 유기물자원화
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• 제22권4호
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• pp.72-86
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• 2014

본 연구는 벼 재배에서 유기물함유 피복자재의 멀칭처리가 벼 생육 및 수량과 논 환경에 미치는 영향을 구명하기 위해 수행하였다. 피복 자재의 원료 및 색상에 따라 쌀함유, 전분함유(투명색과 검정색), 광물질함유, 일반 비닐의 멀칭 처리구와 무피복(관행 및 유기재배) 대조구를 설정하였다. 처리구에 따라 벼의 생육과 수량이 상이하였는데, 벼의 수량은 쌀함유 피복($6.51ton\;ha^{-1}$)과 일반 비닐($6.47ton\;ha^{-1}$)이 가장 높았고, 전분함유 투명 피복($6.25ton\;ha^{-1}$)와 광물질 함유 피복($6.20ton\;ha^{-1}$)이 관행 제초구($6.15ton\;ha^{-1}$)과 유사하였으며, 전분함유 검정 피복($4.93ton\;ha^{-1}$)은 관행 제초구 보다 낮았다. 벼 재배 기간 중 토양의 평균 온도는 $23.6{\sim}24.1^{\circ}C$로 쌀함유 피복에서 가장 높았으며, 토양의 누적온도 역시 쌀함유 피복에서 다른 처리보다 높았다. 토양 이화학성 중 전기전도도, 유기물 함량, 인산 함량 등도 처리간 차이가 있었다. 쌀함유 피복구에서 지렁이에 의한 분변토 생성량($17.7kg\;m^{-2}$)이 다른 처리구($5.5{\sim}9.8kg\;m^{-2}$) 보다 많은 특성을 보였다. 따라서, 벼 수량과 논 토양의 지렁이 활동 측면에서 쌀함유 피복의 효과가 가장 큰 것으로 판단되었다.

• 보존과학회지
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• 제25권3호
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• pp.323-333
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• 2009

진천 사곡리 마애여래입상은 신라말의 마애불 양식을 계승하여 고려시대에 성행한 거군의 마애불로 암석의 종류는 흑운모화강암이다. 이 마애불은 2007년도에 세정을 통하여 생물학적 손상에 대해 보존처리를 실시했으나, 마애불 전면에 걸쳐 크고 작은 불연속면이 발달하고 있어 구조적 불안정을 야기하고 있다. 또한 암반상부에 일조량을 방해하는 수목으로 인하여 습도가 높은 환경에 노출되어 있다. 마애불이 조각된 암반의 구조적 안정성을 검토한 결과, 마애불의 두상과 수인, 법의부분에서 쐐기파괴의 가능성이 높은 것으로 분석되었다. 마애불에 발달한 불연속면의 보존처리는 먼저 절리면을 세정하고 에폭시수지(L-50)를 주입하여 내부를 완전히 충전하였다. 또한 티타늄봉의 삽입과 와이어로프를 설치하고 동종석분과 활석, 무기안료를 혼합한 에폭시수지(L-30)로 표면처리하여 이질감을 최소화하였다. 이 마애불의 균열 및 절리부위에는 균열측정기가 설치되어 모니터링과 함께 지속적인 보존관리가 수행되고 있다.

• 헤리티지:역사와 과학
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• 제38권
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• pp.359-385
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• 2005

우리나라에서 고대에 사용하던 붉은 색 안료에는 주사, 석간주, 장단 등이 있다. 이중에서 주사는 고급스러운 상품(上品)으로써 벽사의 상징적 의미를 지니고 있어 단청, 벽화, 회화를 비롯해 비석, 지석 등에 다양하게 나타나고 있다. 특히 "공사견문록(公私見聞錄)"의 기록에서는 고려재상의 지석 음각에 붉은 칠을 메웠다고 기록되어 있어 비, 신도비, 지석 등에 주사와 같은 붉은 칠이 된 것은 고려시대 또는 그 이전부터라고 볼 수 있을 것이다. 문헌기록을 토대로 하여 비석에 남아있는 붉은 안료들의 몇 사례를 조사해 본 결과 대부분 주사, 장단, 석간주 등이 칠해졌음이 분석되었다. 또한 붉은 색의 발색을 더욱 선명히 하기 위해 붉은 칠 아래 바탕칠로써 호분칠이 된 경우도 발견되었다. 현존하는 붉은 안료가 칠해진 비석들은 대부분 조선시대 이후의 사례들이므로 조선시대에는 비등에 붉은 안료로 주사를 사용했음을 알 수 있었는데, "공사견문록(公私見聞錄)"에 남겨진 기록을 보아 고려시대에도 칠해졌음을 추정해 볼 수 있다. 또한 삼국시대 이미 주사안료가 중국으로부터 수입되어 우리나라에 고가의 상품으로 사용되던 역사적 배경을 살펴볼 때 비에 붉은 안료를 칠하던 것은 고려 이전부터 였을 가능성도 배제할 수 없다. 이렇게 붉은 안료로 주사를 주로 사용했을 것은 주사가 지닌 벽사적 상징의미를 미루어 볼 때 상당히 가능성이 있으며 당시 주사가 매우 고가인 탓에 한때 사용이 금지되기도 하였기에 주사 대신 석간주나 장단과 같은 대체안료가 사용되기도 했을 것으로 추정된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.463-468
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• 1999

The slurry wall of Inchon LNG receiving terminal tank will be planned the super flowing concrete having properties of high strength (required strength 520kg/$\textrm{cm}^2$), no-vibrating and massive structure in the underground. For the performance of this concrete, we investigate and select all materials, the optimum mix design and sensibility test in the laboratory. As test results, we choose portland blast-furnace slag cement and lime stone powder(L.S.P) as cementitious materials, W/C 41%(W/B 35.4%), S/a 50.8% and unit volume of coasre aggregate 0.30 as optimum mix design. Also test result of the fresh and hardened concrete are satisfied with specifications of slurry wall.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.407-410
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• 2005

This research investigates experimentally an effect on the properties of the combined high flowing concrete by mix design factors. The purpose of this study is to determine the optimum mix proportion of the combined high flowing concrete having good flowability, viscosity, no-segregation and design strength(40.0MPa). For this purpose, trial mixings used belite cement+lime stone powder(LSP) are tested by mix design factors including water-cement ratio($47.9\~54.0\%$), fine aggregate volume ratio($41\~45\%$) and coarse aggregate volume ratio($41\~45\%$). As test results of this study, the optimum mix proportion for the combined high flowing concrete is as followings. Water-cement ratio $51.0\%$, fine aggregate volume ratio $43{\pm}1\%$ and coarse aggregate volume ratio $0.30{\pm}0.05m^3/m^3$ and replacement ratio of LSP $42.7\%$.

• 한국식품조리과학회지
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• 제20권3호
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• pp.287-291
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• 2004

The growth inhibitory effect of germanium, or soybean sprouts cultured with germanium, on cancer cells was determined in the cultured gastric cancer cell line, AGS. The growth of AGS was significantly inhibited by the addition of 0.01-1％ organic germanium (Ge-132) and germanium stone powder in MTT cytotoxicity assays. The juice from germanium treated soybean sprouts (GTS) inhibited the growth of AGS gastric cancer cells by 78-88％ at concentrations of 2.5 or 5${\mu}\ell$. The juice from Seomoktae GTS revealed an especially higher growth inhibitory effect than that from the control soybean sprouts (germanium non-treated soybean sprouts, GNTS) in AGS. The results suggest that soybean sprouts cultured with germanium may exert an anticancer effect against gastric cancer cells.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.689-692
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• 2006

The crack of concrete induced by the heat of hydration is a serious problem, particularly in massive concrete structures. In order to control the temperature crack of massive concrete, the selection of appropriate materials like low heat cement, mixture materials, etc. is essential. In tills study, mix proportion using low heat portland cement and lime stone powder was designed and the best mix proportion, B-1, was selected. When bottom slab of the #219 LNG tank in Incheon was constructed, concrete temperature was measured. And thermal stress was analyzed about bottom slab of the LNG tank. As results of the thermal analysis, crack index was 1.60 in bottom slab and satisfied with construction specifications(over 1.0).

• Natural Product Sciences
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• 제13권2호
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• pp.97-100
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• 2007

The present study includes macro and microscopical details, powder study, physico-chemical study and HPTLC fingerprinting of the Piper longum fruits. Microscopic studies revealed the presence of stone cells, starch grains and thin walled fragments of parenchymatous cells. Physico-chemical studies showed alcohol and ether soluble extract 24.53 and 6.7, sugar 0.35, starch 21.33 and tannin 0.83% respectively. Successive soxhlet extract showed maximum percentage of hexane soluble fraction i.e. 22.52. The HPTLC profile has also been performed against the reference marker pipeline, which was identified at R$_f$ 0.42. In the present paper a detailed pharmacognostical evaluation of fruit has been undertaken.

• 대한치과기공학회지
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• 제30권1호
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• pp.17-23
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• 2008

Gypsum products are used for the preparation of stone casts of oral and maxillofacial structures and as important adjuncts to dental laboratory operations involved in the production of dental prosthesis. Accuracy and dimensional stability over time are properties of concern in fixed prothodontics. Gypsum products used in denstry are a form calcium sulfate hemihydrate and are classified as 1 of 5 types according to International Standard Organization(ISO) 6873. All die materials exhibit some dimensional change during setting, but expansion and contraction during setting and dimensional changes in response to varations in temperature and the water-powder ratio must be minimal. Although numerous investigators have studied the properties of die materials, several products have been introduced recently with manufacturer claims of superior dimensional stalility. The aim of this study was to determine the surface properties using various separating materials of dental gypsum products The results were as follows 1. In the comparison of first and second plaster distances before separation in different separating agent, there was no significant difference except using Trio separating agent. The interface using Trio separating agent forms like to pores. 2. In the comparison of first and second plaster distances after separation in different separating agent, there was significant difference. The interface of plasters using WD-40, Trio and Vaseline was showed some gaps. Each they were measured at average 7.97 $\pm$ 2.07 ${\mu}m$, 63.09 $\pm$ 23.25 ${\mu}m$, 27.59 $\pm$ 4.19 ${\mu}m$. 3. In the comparison of the surface, the surface of control sample(using none seperating agent) showed irregular properties and the surface using Trio and Vaseline become wrinkled. Specially the surface using Vaseline was showed shiny properties. But the surface using MAGIC SEP, Plaster seperating agent, WD-40 showed regular properties.

• Steel and Composite Structures
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• 제45권2호
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• pp.205-218
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• 2022

Proper calculation of splitting tensile strength (STS) of concrete has been a crucial task, due to the wide use of concrete in the construction sector. Following many recent studies that have proposed various predictive models for this aim, this study suggests and tests the functionality of three hybrid models in predicting the STS from the characteristics of the mixture components including cement compressive strength, cement tensile strength, curing age, the maximum size of the crushed stone, stone powder content, sand fine modulus, water to binder ratio, and the ratio of sand. A multi-layer perceptron (MLP) neural network incorporates invasive weed optimization (IWO), cuttlefish optimization algorithm (CFOA), and electrostatic discharge algorithm (ESDA) which are among the newest optimization techniques. A dataset from the earlier literature is used for exploring and extrapolating the STS behavior. The results acquired from several accuracy criteria demonstrated a nice learning capability for all three hybrid models viz. IWO-MLP, CFOA-MLP, and ESDA-MLP. Also in the prediction phase, the prediction products were in a promising agreement (above 88%) with experimental results. However, a comparative look revealed the ESDA-MLP as the most accurate predictor. Considering mean absolute percentage error (MAPE) index, the error of ESDA-MLP was 9.05%, while the corresponding value for IWO-MLP and CFOA-MLP was 9.17 and 13.97%, respectively. Since the combination of MLP and ESDA can be an effective tool for optimizing the concrete mixture toward a desirable STS, the last part of this study is dedicated to extracting a predictive formula from this model.