• Title/Summary/Keyword: Physico-chemical property

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Evaluation of Compost Maturity by Physico-chemical Properties and Germination Index of Livestock Manure Compost (축분 퇴비의 이화학적 특성과 발아지수를 이용한 부숙도 평가)

  • Chang, Ki-Woon;Hong, Joo-Hwa;Lee, Jong-Jin;Han, Ki-Pil;Kim, Nam-Cheon
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.2
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    • pp.137-142
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    • 2008
  • This study was conducted to evaluate the humification grade of compost, based on physico-chemical property and phyto-toxicity during the composting with three kinds of livestock manures and saw dust. The ratios of the compost, which was mixed with pig manure(P) and sawdust(S) were 4 : 6(PS-1), 5 : 5(PS-2) and 6 : 4(PS-3); poultry manure(PO) and sawdust(S) were 4 : 6(POS-1), 5 : 5(POS-2) and 6 : 4(POS-3); cow manure(C) and sawdust(S) were 4 : 6(CS-1), 5 : 5(CS-2) and 6 : 4(CS-3) by volume to volume, and they were decomposed for 60 days. In the result, the temperature in all treatments during composting rapidly increased above $65.4^{\circ}C$, and then gradually decreased to around $40^{\circ}C$. At 60 day, after the treatment, pH 5.9 ~ 8.0 at the incipient stage increased to 7.6 ~ 8.5, and the C/N ratio was 13.8 ~ 21.1 at the final composting stage. Germination Index(G.I.) showed in the range of 75.1 ~ 94.6 in all treatments at day 60. Therefore, it is likely recommended to take the best humification grade when the temperature maintains above $65^{\circ}C$ longer than a day at minimum, in the range of pH 6.5 ~ 8.5 for the final compost, under 20 of C/N ratio, and G.I. above 80. The level of G.I. above 80 should be the mature compost which could be used in the field without gas demage to crops.

Combined Toxic Effects of Polar and Nonpolar Chemicals on Human Hepatocytes (HepG2) Cells by Quantitative Property - Activity Relationship Modeling

  • Kim, Ki-Woong;Won, Yong Lim;Park, Dong Jin;Kim, Young Sun;Jin, Eun Sil;Lee, Sung Kwang
    • Toxicological Research
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    • v.32 no.4
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    • pp.337-343
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    • 2016
  • We determined the toxicity of mixtures of ethyl acetate (EA), isopropyl alcohol (IPA), methyl ethyl ketone (MEK), toluene (TOL) and xylene (XYL) with half-maximal effective concentration ($EC_{50}$) values obtained using human hepatocytes cells. According to these data, quantitative property-activity relationships (QPAR) models were successfully proposed to predict the toxicity of mixtures by multiple linear regressions (MLR). The leave-one-out cross validation method was used to find the best subsets of descriptors in the learning methods. Significant differences in physico-chemical properties such as boiling point (BP), specific gravity (SG), Reid vapor pressure (rVP) and flash point (FP) were observed between the single substances and the mixtures. The $EC_{50}$ of the mixture of EA and IPA was significantly lower than that of contained TOL and XYL. The mixture toxicity was related to the mixing ratio of MEK, TOL and XYL (MLR equation $EC_{50}=3.3081-2.5018{\times}TOL-3.2595{\times}XYL-12.6596{\times}MEK{\times}XYL$), as well as to BP, SG, VP and FP (MLR equation $EC_{50}=1.3424+6.2250{\times}FP-7.1198{\times}SG{\times}FP-0.03013{\times}rVP{\times}FP$). These results suggest that QPAR-based models could accurately predict the toxicity of polar and nonpolar mixtures used in rotogravure printing industries.

Changes of Physico-chemical Soil Properties, Major Soil Nutrient Contents, and Weed Vegetation in Paddy Fields during Fallow Period (휴경답에서의 토양의 이화확적 특성, 주요 영양분 및 잡초종의 변화)

  • Han, Sung-Uk;Chung, Gap-Chae;Chon, Sang-Uk;Lee, Hee-Jae;Guh, Ja-Ock
    • Korean Journal of Environmental Agriculture
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    • v.17 no.3
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    • pp.211-214
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    • 1998
  • Changes in physico-chemical properties and major nutrient contents were investigated in the soil of paddy fields during fallow period. Weed vegetation change in the fallow paddy fields was also examined. As the fallow period became longer, organic matter content in the paddy soil has gradually increased. Soil pH of the paddy fields has not changed until three years of fallow period and thereafter slightly increased. Cation exchange capacity of the paddy soil, and exchangeable N, K, Ca and Mg contents in the soil tended to decrease until three years of fallow period and then increase with the prolonged fallow period. As the fallow period became longer, available $P_2O_5$ content in the paddy soil has continuously decreased. Available $SiO_2$ content in the paddy soil has not changed until three years of fallow period and thereafter increased. The vegetation in the fallow paddy fields have mostly been occupied by the weeds of the Gramineae, Cyperaceae, and Compositae. As the fallow period became longer, the weeds of the Polygonaceae and Juncaceae have increased, whereas the weeds of the Leguminosae, Commelinaceae, Pontederiaceae, and Onagraceae have gradually disappeared. However, the weeds of the Gramineae and Cyperaceae have always been dominant in the paddy fields during the fallow paddy period.

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The Effects of Various Dehiscence Materials, Growth Regulators and Fungicides on the of Ginseng Seed ( Panax ginseng C A. Meyer ) (개갑처리재료, 생장조절제 및 살충제가 고려인삼종자의 개갑에 미치는 영향)

  • 양덕조;천성기
    • Journal of Ginseng Research
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    • v.6 no.1
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    • pp.56-66
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    • 1982
  • The effects of various dehiscent application such as dehiscent materials (big chaffs, vermiculite etc.), growth regulators and agricultural chemicals (plant protector.) on stimulation of dehiscence and shortening of dehiscent period were investigated Results obtained were as follows : 1. The moisture content of endosperm and seed coat at 10 day after dehiscent application amounts between 40% and 50%. 2. Endosperm diameter was increased with time of stratification, and the embryo growth showed in linear function, 3. Non-dehiscent seed showed also normally development of embryo, and the property of dehiscence dependent from physico-chemical nature of ginseng seed coat. 4. The best dehiscent materials were big chaffs and followed vermiculite, sand and sand with big chaffs. 5. The effect of dehiscence of ginseng seed showed higher activity in fungi than in bacteria in general. 6. Agricultural chemicals ( plant Protector) reduced the dehiscent rate of ginseng seed 7. The best timing of dehiscent treatment was between August 1 and August 10 but the smaller amount of dehiscent rate after August 10 dehiscent appllication indicated that big chaffs and growth regulator treatment may be controlled shortening of dehiscent period of ginseng seed.

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HTPB Propellant Ageing Property and HFC Base Shelf-Life Evaluation Method (HTPB 추진제 노화 특성 및 HFC 기반 수명 평가 기법)

  • Cho, Wonho;Westerlund, M.;Ryoo, Baek-Neung;Jung, Gyoo-Dong;Yoo, Ji-Chang
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.148-153
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    • 2017
  • During natural ageing of HTPB propellant undergoes a series of slow physico-chemical degradation reactions. By using accelerated ageing conditions it is possible to simulate the material behaviour at different time-temperature conditions especially focused on the in-service conditions. Ageing behaviour of HTPB propellant were investigated using HFC(Micro-Heat Flow Calorimeter) is universal technique for measuring the rate of slow chemical and physical processes in long-term storage.

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HTPB Propellant Ageing Property and HFC Base Shelf-life Evaluation Method (HTPB 추진제 노화 특성 및 HFC 기반 수명 평가 기법)

  • Cho, Wonho;Westerlund, M.;Ryoo, Baekneung;Jung, Gyoodong;Yoo, Jichang
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.5
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    • pp.59-65
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    • 2018
  • During natural aging, hydroxyl-terminated polybutadiene(HTPB) propellant undergoes a series of slow physico-chemical degradation reactions. By using accelerated ageing conditions it is possible to simulate the material behavior at different time-temperatures focusing on in-service conditions. Aging behaviors of HTPB propellant are investigated using HFC(heat flow calorimeter), a universal technique for measuring the rate of slow chemical and physical processes in long-term storage.

Investigation of Soil Physico-chemical Properties in Saemangeum Reclaimed Tidal Land in Korea

  • Ahn, Byung-Koo;Lim, Yeon-Yi;Ko, Do-Young;Lee, Chang-Kyu;Kim, Jin-Ho;Song, Young-Ju;Lee, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.4
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    • pp.347-354
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    • 2016
  • This study was conducted to investigate the physical and chemical properties of soils in Saemangeum reclaimed lands. The investigated areas were total 5,020 ha which included 220 ha for Agricultural Life site, 2,450 ha for Tourism & Leisure site, 1,130 ha for Industrial & Research site, 820 ha for Bioenergy crop production site, and 400 ha for Rural City site. Soil samples consisting of the upper 20 cm from the surface were collected in every $200m{\times}500m$ of the each site in March and September, 2015. Particle size distribution of soils in the reclaimed land was 83.2% sand, 8.6% silt and 8.2% clay in average. Soil texture was distributed as 40.8% sandy soil, 35.5% loamy sand, and 19.7% sandy loam. Based on the investigation of soil chemical properties conducted in March, 2015, soil pH, electrical conductivity of a saturated soil paste extract (ECe), and exchangeable (Exch.) $K^+$ and $Mg^{2+}$ concentrations were higher than those of the optimum levels for upland soil, whereas soil organic matter content, available (Avail.) phosphate concentration, and Exch. $Ca^{2+}$ concentration were lower than those of the optimum ranges. Depending on the results of the soil chemical properties measured in September, 2015, soil pH, ECe, and Exch. $K^+$ concentration were higher than those of the optimum levels, but soil organic matter, Avail. phosphate, and Exch. $Ca^{2+}$ concentration were lower than the optimum ranges. In addition, distribution of sodic soil ranged between 41.4% and 50.0%, and saline soils were from 16.4 to 31.8%. Soils with pH values above 7.0 increased from 15.3% in March to 35.2% in September. Soils with ECe values over $4.8dS\;m^{-1}$ increased from 45.6% to 50.7%, whereas soils with the values below $2.0dS\;m^{-1}$ decreased from 42.8% to 36.9%.

A Study on Physico-chemical Property and Composition of Velvet Antler and Byproducts in Elk. (Elk종의 녹용과 부산물의 이화학적 특성에 관한 연구)

  • 이길왕
    • Journal of Life Science
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    • v.14 no.3
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    • pp.496-500
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    • 2004
  • This study has been performed for physico-chemical property and composition of sinew, testes, tail, blood and velvet antler in Elk. Amino acid contents in the sinew taurine, alanine, histidine, and lysine were high contained, histidine, glutamic acid, taurine, and lysine were high contained in testes, glutamic acid, lysine, alanine, glycine, and phenylalanine were high contained in tail, histidine, glycine, and lysine were high contained in blood, glutamic acid, lysine, taurine, alanine, and glycine were high contained in velvet antler. And, based on the amount of mineral, $K^{+}$, $Ca^{2+}$, and $P^{+}$ were 444.8, 166.6 and 242.9mg per 100g in sinew, respectively. $K^{+}$, $Ca^{2+}$ and $P^{+}$ were 294.4, 330.5, and 514.3 mg per 100g in testes, respectively, $K^{+}$, $Mg^{2+}$, and $P^{+}$ were 1420.6, 118.4, and 1105.2mg per 100 mg in tail, respectively. Fe3+,-K+, and P+ were 344.1, 1023.6 and 157.2 mg per 100 mg in blood, respectively and $K^{+}$, $Ca^{2+}$ and $P^{+}$ were 888.4, l1533.1 and 14722.0 in velvet antler, respectively. Finaly, difference were found in comparison of composition of free mwtal ion (N $a^{+}$, $K^{+}$, $Mg^{2+}$ and $Ca^2$) bwteen blood, tail, tests, sinew and velvet antler, and composition of free metal in blood higher than those othersd higher than those others.

Energy Band Structure and Photocatalytic Property of Fe-doped Zn2TiO4 Material

  • Jang, Jum-Suk;Borse, Pramod H.;Lee, Jae-Sung;Lim, Kwon-Taek;Jung, Ok-Sang;Jeong, Euh-Duck;Bae, Jong-Seong;Won, Mi-Sook;Kim, Hyun-Gyu
    • Bulletin of the Korean Chemical Society
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    • v.30 no.12
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    • pp.3021-3024
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    • 2009
  • $Zn_2Ti_{1-x}Fe_xO_4\;(0\;{\leq}\;x\;{\leq}\;0.7)$ photocatalysts were synthesized by polymerized complex (PC) method and investigated for its physico-chemical as well as optical properties. $Zn_2Ti_{1-x}Fe_xO_4$ can absorb not only UV light but also visible light region due to doping of Fe in the Ti site of $Zn_2TiO_4$ lattice because of the band transition from Fe 3d to the Fe 3d + Ti3d hybrid orbital. The photocatalytic activity of Fe doped $Zn_2TiO_4$ samples for hydrogen production under UV light irradiation decreased with an increase in Fe concentration in $Zn_2TiO_4$. Consequently, there exists an optimized concentration of iron for improved photocatalytic activity under visible light (${\lambda}{\leq}$420 nm)

The Change of Physico-Chemical Properties of Paddy Soil in Reclaimed Tidal Land (간척지 논토양의 물리화학성 변동에 관한 연구)

  • Yang, Chang-Hyu;Yoo, Chul-Hyun;Jung, Ji-Ho;Kim, Byeong-Su;Park, Woo-Kyun;Ryu, Jin-Hee;Kim, Taek-kyum;Kim, Jae-Duk;Kim, Seong-Jo;Baek, Seung-Hwa
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.2
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    • pp.94-102
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    • 2008
  • The physico-chemical properties of ten reclaimed saline soils in five soil series of west-south Korea were analyzed according to the years past after reclamation. The soil samples were collected at the same sites two times in 2000 and 2004. The physico-chemical properties in 2000 had been changed in 2004 as follows. Soil salinity was the highest in Podu and desalinization period was the shortest in Munpo and Yeompo. Seasonal ground water level were above 100 cm in all regions that were 30 years old reclaimed tidal land, which was the same results of normal paddy field. In the case of soil physical changes, bulk density increased in fine textured soil (Poseung and Podu) but decreased in coarse textured soil (Gwanghwal, Munpo, and Yeompo). Porosity decreased in fine textured soil(Poseung and Podu) but increased in coarse textured soil. These reason were as follows. Fine textured soil were increased in solid phase but decreased in liquid and gaseous phase. Coarse textured soil, Gwanghwal and Munpo except for Yempo, were increased in gaseous phase but decreased in solid and liquid phase. Yempo that have low water table level were increased in liquid phase but decreased in solid and gaseous phase. Soil hardness increased in 4 soil series except for Munpo. In the case of chemical property changes, although there were more or less difference, it showed decreasing tendencies. Soil pH, the content of organic matter, available phosphate, and available silicate of five soil series were decreased during the four years. The content of exchangeable cation also decreased except for magnesium.