• 한국식품위생안전성학회지
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• 제6권1호
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• pp.49-56
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• 1991

인삼 엽록차의 위생화를 위한 화학 훈증제 처리 및 감마선 조사가 시료의 몇가지 이화학적 특성에 미치는 영향을 조사하였다. 녹차의 품질에 관련된 가용성분, 사포닌 및 탄닌성분은 상업적 조건 ethylene oxide 처리와 10kGy 까지의 감마선 조사에 대하여 안정하였다. 그러나 비타민 C 및 클로로필은 5kGy 이상 조사와 훈증 처리시에 유의적으로 감소되었고, 녹차의 휘발성 성분, 추출액의 색도 및 pH는 살균선량 범위인 5kGy 조사군에 비해 훈증처리군에서 변화가 심하게 나타났다 .

• Current Research on Agriculture and Life Sciences
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• 제20권
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• pp.39-47
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• 2002

This study was carried out in order to produce useful material for the forest multiple use and forest protection by soil physico-chemical analysis of studied area in Mt. Palgong. The results of soil physico-chemical analysis and statistical analysis represented as following 2 points. 1. Soil depth was in the range of average 61.1 cm and soil texture was loamy sand and sandy loam except Donghwasa area. The part of solid phase and gaseous phase were higher than other areas, but liquid phase was less in verse. Soil water content was in an average 49.5%, penetrability was average $1.95{\times}E^{-2}cm/sec$ and the average of soil hardness was $1.64Kg/cm^2$. This data showed that soil water content, penetrability and soil hardness were good at Mt. Palgong forest soils. 2. Soil pH was the range of 3.4 to 6.0, organic carbon content was 2.8% that is nearly mean of the Korea brown forest soils, total N content is somewhat smaller than that of other places, and total average C/N ratios was 13.9. Average available $P_2O_5$ concentration was 5.05 mg/kg that is lower than that of any others. The concentration of available P of coniferous forests is higher than that of deciduous forests. Exchangeable cations content is similar to those of the Korea brown forest soil and the order of the cation content extent is $Ca^{2+}$ > $Mg^{2+}$ > $Na^+$ > $K^+$.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1630-1637
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• 2014

The objective of the study was to determine the quality and fatty acid profiles of mutton cuts purchased from rural and urban localities in South Africa. Five hundred and ten samples were collected in four seasons from both rural and urban shops and butcheries. Samples were immediately transported to the laboratory in cooler boxes with ice where the following physico-chemical characteristics of mutton were determined; meat pH, color ($L^*$, $a^*$, and $b^*$), cooking losses and Warner Braztler shear force and replicates stored at $-20^{\circ}C$ pending fatty acid analysis. Meat $L^*$ values were lowest ($24.7{\pm}0.49$) in winter and highest ($32.2{\pm}0.49$) in spring. The loin and sirloin cuts recorded the highest intramuscular fat whilst rib and leg cuts recorded the lowest intramuscular fat. In conclusion intramuscular fat, fatty acid profiles and physico-chemical quality of mutton were significantly affected by season and meat portion and not necessarily by the locality and class of shop.

• 한국물환경학회지
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• 제29권3호
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• pp.428-437
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• 2013

Physico-chemical water quality parameters and the phytoplankton communities from 12 sites in Oship-stream, Songchunstream, and Namdae-stream, located Gyeongsangbukdo Uljin-gun, Yeongdeok-gun, and Pyeonghae-eup respectively, were investigated from April 2009 to February 2010. Oship-stream, which is an open estuary, was easily affected by ocean current compared to that of Songchun-stream and Namdae-stream. OS3 and OS4 conductivity was higher with a season average of 3,397 ${\mu}s/cm$. The streams were mesotrophic to hypertrophic. Biological oxygen demand (BOD) was about 3mg/L, which was level 2 on the water quality ratings, but a concentration of 5mg/L in April 2009 indicated increased pollution due to drought. A total of 118, 117, and 124 phytoplankton taxa were found in Oship-stream, Songchun-stream, and Namdae-stream, respectively. The apparent dominant species in the polluted waters included Cryptomonas ovata, Fragilaria construens var. venter, Oscillatoria limnetica, O. limosa, and Phormidium tenue. All of Oship-stream, SC2 and SC4 of Songchun-stream, and ND3 of Namdae-stream were eutrophic as a result of standing crop analysis. BOD was highly correlated with chlorophyll-a content(r=0.52). Phosphorus concentration and proliferation of phytoplankton were thought to most affect BOD concentration in all three streams.

• Environmental Analysis Health and Toxicology
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• 제23권3호
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• pp.143-164
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• 2008

Concern about perfluorinated compounds (PFCs) is growing nationally as well as globally. PFCs could be considered emerging POPs due to their environmentally persistent, bioaccumulative, and potentially harmful properties. Moreover. perfluoroalkylates (PFAs) such as PFOS and PFOA are reported to experience long-range transport (LRT) to the Arctic in spite of their low volatility and strong solubility. The possible pathways contributing to LRT have been proposed but are still in debate in combination with unclear source definition and uncertain physico-chemical properties. The environmental fate of PFCs is more complicated because of the presence of precursors that are degraded to PFAs and are extremely different from their daughters, PFAs. in physico-chemical properties. To what extent and through what pathways are human and wildlife exposed is determined by the environmental fate and distribution of PFCs. To define uncertainties in fate and distribution thus is critical to prevent erroneous policy and/or determination related with exposure and risk reduction. This article aimed to review controversy and/or uncertain issues for the environmental fate and distribution of PFCs and to prospect research topics necessary to dissolve uncertainties.

• 동아시아식생활학회지
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• 제20권1호
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• pp.84-94
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• 2010

Physico-chemical analysis and sensory test of loin of lamb were carried out by four different methods such as grilling, pan-frying, oven-roasting and boiling. The crude fat content was all the same at three cooking methods except boiling. The moisture content was not different among grilling, pan-frying and oven-roasting. Hunter's color L-value(lightness) was lowest at grilling method. However, the heating loss appeared greatly at grilling. The hardness of the lamb-loin after cooking showed big differences with the control except boiling treatment. Amino acids in fillet contained highly in the order of glutamic acid > aspartic acid > cystein. The grilling showed a good value not only color of a sensory test but also the appearance. The oven-roasting cooking gave the tenderness and juiciness. The oven-roasting method showed good sensation to overall taste. Therefore, the oven-roasting (at $150^{\circ}C$ for 9 minutes) was suggested as the superior method when the loin of lamb is cooked for reducing off-flavour.

• Journal of Ginseng Research
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• 제35권4호
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• pp.487-496
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• 2011

Good manufacturing practice (GMP)-based quality control is an integral component of the common technical document, a formal documentation process for applying a marketing authorization holder to those countries where ginseng is classified as a medicine. In addition, authentication of the physico-chemical properties of ginsenoside reference materials, and qualitative and quantitative batch analytical data based on validated analytical procedures are prerequisites for certifying GMP. Therefore, the aim of this study was to propose an authentication process for isolated ginsenosides $Rb_1$ and $Rg_1$ as reference materials (RM) and for these compounds to be designated as RMs for ginseng preparations throughout the world. Ginsenoside $Rb_1$ and $Rg_1$ were isolated by Diaion HP-20 adsorption chromatography, silica gel flash chromatography, recrystallization, and preparative HPLC. HPLC fractions corresponding to those two ginsenosides were recrystallized in appropriate solvents for the analysis of physico-chemical properties. Documentation of the isolated ginsenosides was made according to the method proposed by Gaedcke and Steinhoff. The ginsenosides were subjected to analyses of their general characteristics, identification, purity, content quantitation, and mass balance tests. The isolated ginsenosides were proven to be a single compound when analyzed by three different HPLC systems. Also, the water content was found to be 0.940% for $Rb_1$ and 0.485% for $Rg_1$, meaning that the net mass balance for ginsenoside $Rb_1$ and $Rg_1$ were 99.060% and 99.515%, respectively. From these results, we could assess and propose a full spectrum of physicochemical properties for the ginsenosides $Rb_1$ and $Rg_1$ as standard reference materials for GMP-based quality control.

• 한국환경복원기술학회지
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• 제13권6호
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• pp.97-106
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• 2010

Earthworm, a prominent ecosystem engineer within many terrestrial ecosystems, can exert profound influences on various abiotic/biotic environments through bioturbation processes such as burrowing, casting and mixing of litter and soil. In this study, we investigated how the presence or absence of earthworm (Oligochaeta) can alter the soil physico-chemical conditions and ultimately the distribution and abundance of Collembola which constitutes a large proportion of the soil fauna. During September 2010, soil organisms along with soil samples were collected from randomly installed 20 plots in Mt. Gwan-ak. We examined the differences in the abundance of Collembola among plot samples in respect to the presence/absence of earthworm and soil physico-chemical conditions (i.e., pH, $PO_4^{3-}$, $NO_3^{2-}$, organic matter (OM), electrical conductance and water content). Analysis of soil physico-chemical environment revealed a significantly higher organic matter content and electrical conductance in plots with earthworm compared to plots without earthworm. Abundance of Collembola were not only higher in plots with earthworm than in plots without earthworm, but were also positively correlated with availability of OM present in the environment. The results suggest that positive impacts of earthworm on the abundance of Collembola in this study may have been due to their ability to effectively modify soil physico-chemical conditions favored by Collembola. Such conspicuous influence of earthworm's activity on below-ground community suggests their potential significance in forest restoration or revegetation process.

• 해양환경안전학회지
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• 제26권7호
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• pp.864-872
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• 2020

국제해사기구(IMO)의 황함유량 규제에 따르는 저유황연료유는 생산 공정에 따라 다양한 물리화학적 특성을 가지게 된다. 본 연구는 저유황연료유 및 저유황-고유황 혼합연료유의 물리화학적 특성연구 결과를 해양오염 방제대응의 기초자료로 활용하고자 한다. 연구에 사용된 혼합연료유는 황함유량이 0.46 mass%인 저유황연료유와 0.36 mass%인 저유황연료유에 고유황연료유를 25, 50, 75 mass% 혼합하여 제조하였다. 이 혼합연료유에 대해 동점도, 유동점 및 Saturates, Aromatics, Resins, Asphaltenes(SARA)분포 등 물리화학적 특성에 대해 실험실 연구를 하였다. 동점도가 높고 유동점이 낮은 특징의 고유황연료유가 75 mass% 혼합함에 따라, 혼합연료유의 동점도는 350.2 %까지 증가 하였으며, 유동점이 23℃와 -11℃의 저유황연료유는 각각 -3℃ 및 -6℃까지 유동점이 내려가거나 올라갔다. Asphaltenes 분포가 적은 저유황연료유에 고유황연료유를 혼합함에 따라, Saturates분포는 68.8 %까지 감소하고, Asphaltenes분포는 1,417 %까지 크게 증가하였다.