• 한국토양비료학회지
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• 제27권3호
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• pp.189-194
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• 1994

신개간경사지(新開墾傾斜地)에서 생산력 증대를 위한 물리화학적인 개량방법(改良方法)과 고구마 재배에 대한 기초자료를 얻고자 1985년부터 4년간 송정양토(松汀壤土)에서 고구마를 재배하면서 토양물리화학성의 년차간(年次間) 변화량(變化量)과 변화율(變化率) 및 고구마의 수량을 조사, 분석하였다. 1. 토양의 용적밀도는 토심(土深)에 관계없이 2년차부터 계속 높아졌으나 경도(硬度)는 표토에서는 같은 경향이나 심토에서는 일정한 경향이 없었다. 2. 고구마의 4년간 평균수량(平均收量)은 종합개량구(綜合改良區)에서 32.68ton/ha으로 제일 많았고 대조구(對照區)에 비해 59% 증수(增收)되었으며 처리별로는 인산구>심경구>석회구>퇴비구>대조구 순으로 많았다. 3. 년차간(年次間) 고구마 수량과 토양의 물리화학성과의 상관계수는 표토에서는 용적밀도, 경도, 양이온치환용량과 심토에서는 용적밀도, 토양수분, 양이온치환용량과 유의성이 높았다. 4. 토양의 물리화학성 변화률(變化率)과 고구마 수량(收量)과의 상관관계(相關關係)는 유기물 함량을 제외한 다른 특성과 유의성이 있었고 개량제(改良劑) 시용(施用)이 없었던 4년차에 토양(土壤)의 물리화학성(物理化學性)이 악화(惡化)되었음을 알 수 있었다.

• 한국해안해양공학회지
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• 제18권3호
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• pp.251-261
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• 2006

본 연구의 목적은 금강 하구역 미세-점착성 퇴적물의 침강속도를 정량적으로 산정하고, 그 침강특성의 금강 하구 내에서의 지엽적 변화 및 계절적 변화와 타 지역 침강속도 결과와의 비교/분석을 통한 공간적 변화를 해석하는데 있다. 또한 실험분석을 통하여 점착성 퇴적물의 물리 화학적 특성 즉, 입경분포, 유기물함량, 광물질구성 등의 공간적 변화를 정량적으로 조사한 후, 이러한 특성들과 침강속도간의 상관관계 및 침강속도의 정량적 변화에 미치는 영향에 대해서도 해석하였다. 침강실험의 결과로서, 금강 하구역 미세점착성 퇴적물은 부유사 농도 값이 0.1 < C < 80 g/L에서 $0.01\;<\;W_{s}\;<\;1mm/sec$의 침강속도 값을 갖는 것으로 확인되었으며, 산정된 침강 속도는 다른 지역(새만금, Tampa만, Severn하구, Okeechobee호)과 비교해 정량적으로 상당한 차이를 보였으나 금강 하구역 내에서의 지엽적 변화 및 계절적 변화는 미미한 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.505-512
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• 1999

Soft marine clay deposits pose several foundation problems. Generally, lime stabilization is used worldwide for solidifying of soft marine clay deposits. In this paper, a series of laboratory tests were conducted to verify clay-lime reaction. A clay was collected from Pusan, which was mixed with various quantities of quick lime and slaked lime. Various compounds produced by clay-lime reaction were identified by X-ray diffraction analysis. The physico-chemical properties of the clay were also investigated. Compounds such as calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH), calcium aluminate (CA), hillebrandite, and gehlenite were identified. It is likely that such compounds were mainly produced by pozzolanic reaction. Based on the change of physico-chemical properties obtained by the reaction, the water content was considerably decreased when lime was added to the clay. In addition, unconfined strength was increased. In the other hand, quick lime was more effective than slaked lime in decreasing and increasing of the water content and unconfined strength, respectively. Fewer cracks were produced when the clay was mixed with quick lime. It is suggested that these beneficial changes produced by the mixing of the clay and lime depend on the properties of compounds obtained by chemical reaction.

• 원예과학기술지
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• 제29권3호
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• pp.201-210
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• 2011

This experiment was conducted to investigate physical and chemical characteristics by volume fractions of root media using peatmoss, perlite, and vermiculite, along with effects on the growth of pot chrysanthemums (Dendranthema ${\times}$ grandiflorum 'Vemini') in a C-channel mat irrigation system. To evaluate the physico-chemical properties of 20 root media, the bulk density, particle density, total pore space, pore space, ash content, organic matter, pH, and electrical conductivity were measured and data were analyzed using principal component analysis (PCA). PCA scores revealed that physico-chemical properties changed by the blending of peatmoss, perlite, and vermiculite. The 20 root media were divided into three main groups by hierarchical cluster analysis. At the end of the experiment, the pH and EC of the root media were measured from media divided into four layers. The pH of root media without plants showed a strong linear relationship and the pH of root media with plants increased exponentially. The change of EC in the root medium was indicated as a hyperbolic curve. Plant growth characteristics according to growth in the 20 root media were analyzed by PCA. It was found that the mixing ratios of the root media affected plant growth characteristics. Therefore, mixing ratio is an important factor for pot-plant production in a subirrigation system.

• 한국해양공학회지
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• 제19권4호
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• pp.42-48
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• 2005

The sediment of Shihwa Lake contains an abundant quantity of cohesive sediments. The transport processes of the cohesive sediments are complex and difficult to predict, quantitatively. The cohesive sediments are the primary reason for the pollution of the environment and water quality in the coastal region. In this study, a column test has been performed. In order to quantify the settling velocities of sediment from Shihwa Lake, an experiment was conducted using a specially designed 1.8m tall settling column. A series of settling tests and physico-chemical property tests on Shihwa Lake cohesive sediments has been conducted to investigate the correlation between settling properties and their physico-chemical properties, which are represented as grain size distribution, mineralogical composition, and percentage oj organic contents. Experimental results of physico-chemical property tests show that Shihwa Lake sediments are relatively large in average grain $size(74\mu m)$ contain very small organic $material(6\%)$, and are dominantly composed of Quarts, which has relatively low cohesion. Thus, Shihwa Lake sediments might be specified as those whose settling properties are more influenced by gravity than cohesion. It is concluded that the magnitude of settling velocities of muddy sediments can be quite different, regionally, and it implies that field or laboratory experiments for settling velocity measurement should be preceded over the numerical modeling of muddy sediment transport, in order to obtain the reliable prediction results for a given specific site.

• 한국해안·해양공학회논문집
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• 제24권3호
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• pp.203-209
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• 2012

본 연구에서는 최신의 유동측정기를 이용하여 고령토 및 세 종류의 도자기토 시료에 대해 머드유동층의 유동학적 특성, 즉 밀도에 따른 점성 및 항복응력의 변화특성이 정량적으로 산정되었다. 본 연구에서는 또한 이러한 머드유동층의 물리화학적 기본특성들이 각 시료별로 측정되었으며, 이 기본특성들과 유동학적 특성들 사이의 상관관계가 정성적으로 분석되었다. 본 연구결과에 따르면, 머드유동층은 일반적으로 의가소성 거동특성을 보이며, 그 점성 및 항복응력은 모두 밀도가 증가함에 따라 지수함수적으로 급격히 증가하나, 각 시료별로 이 값들은 정량적으로 큰 차이를 보이는 것으로 나타났다.

• 한국식품과학회지
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• 제27권5호
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• pp.768-772
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• 1995

건 구기자와 볶음조건을 달리한 볶은 구기자의 열수 추출물에 대하여 여러 가지 이화학적 특성을 조사하였다. 건 구기자의 일반성분은 수분 17.5%, 회분 5.4%, 지방 14.7%, 단백질 18.9%, 섬유질 12.8%, 당질 31.7%였다. 열수 추출시 추출수율은 볶음온도와 시간이 증가할수록 가용성 고형분이 더 빨리 추출되었으며, 색도는 명도가 감소하고 적색도가 증가하여 추출물이 더 진한 갈색을 나타내었고 탁도 역시 증가하였다. pH는 볶음온도와 시간이 증가할수록 5.08에서 4.38로 감소하였고 산도는 0.09%에서 0.16%로 증가하였다. 유리당 함량은 볶음온도와 시간이 증가할수록 감소하였고 특히 glucose함량이 0.45%에서 0.12%로 크게 감소하였다. 지방산 조성은 건 구기자에 비해 볶음온도와 시간이 증가할수록 linoleic acid의 비율이 감소하고 palmitic acid의 비율이 증가하였다. 관능검사 결과는 볶음온도와 시간이 증가할수록 단 냄새, 탄 냄새, 신 맛, 탄 맛, 떫은 맛 등은 증가하였고 단 맛과 구수한 맛은 약간 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제6권4호
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• pp.265-269
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• 1996

An isolate of Streptomyces rochei synonym was found to produce antibiotics with narrow anti-microbial spectrum against Streptococcus and Xanthomonas sp. Among the antibiotic complex produced by the strain, the main active compound was isolated, and its physico-chemical properties and biological activities were investigated. Molecular weight of the compound was determined to be ${[M+H]}^+$ 797 (FAB-MS). UV, $^1H \;and\;^{13}C$ NMR, and IR spectra suggested that the compound is a kirromycin-like aurodox group antibiotic. However, the anti-microbial spectrum of the main compound was slightly different from that of kirromycin. In addition, it was newly found that kirromycin showed a selective anti-microbial activity against Streptococcus pyogenes and phytopathogenic Xanthomonas sp.

• The Korean Journal of Ecology
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• 제8권1호
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• pp.21-29
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• 1985

The physico-chemical properties of sediment, the species composition and biomass of benthic diatoms were investigated in the intertidal zone of Kum river estuary, from July 1983 to May 1984. Sandflat sediment was more oligotrophic than mudflat one. The diatom composition was primarily associated with sediment grain size. The dominant epipelic diatoms belonged to the centric diatoms such as Paralia sulcata and Thalassiosira spp., while the epipsammic diatoms consisted mainly of Achnanthes haukiana and Amphora sabyii. Diatom flora of sandflat was more significantly diverse than that of mudflat. Mean yearly crop of sandflat diatoms was 2.8 times greater than that of mudflat diatoms and peaked at March reflecting the greater availability of ammonia.

• 한국생활과학회지
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• 제13권6호
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• pp.1031-1036
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• 2004

Effects of irradiation on physico-chemical properties of beef and pork loins were examined. Beef and pork were irradiated at dose levels of 0, 0.5, 1, 2, 3, and 5 kGy with a use of Co-60 source. The drip loss of beef increased from 0 kGy to 5 kGy, whereas that of pork remained unchanged. TBA values of beef and pork increased due to irradiation. Irradiation caused a decrease in the lightness, redness, and yellowness of beef, whereas it did an increase in the same properties of pork. Irradiation also contributed to an increase in the solubility of salt soluble protein.