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Identification of Pelleting Materials and Effect of Nutrient Addition on the Germination of Pelleted Lettuce Seeds (상추 펠렛종자의 피복물질 탐색과 영양물질 첨가가 발아력에 미치는 영향)

  • Kang, Jum-Soon
    • Protected Horticulture and Plant Factory
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    • v.13 no.1
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    • pp.8-15
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    • 2004
  • Seedling mechanization of lettuce is known to be difficult due to the small seed size and the irregular seed shape. The purpose of seed pelleting is to make seedling mechanization possible by enlarging the seed size. After that, it can reduce seedling and thinning labours and can also save seeds. According to the results, there were significant differences on the percent germination and day to 50% final germination in accordance with the pelleting polymer. Among the pelleting polymer, gemination of seeds using polynimyl alcohol (PVA) was generally smooth, and followed by polyvinyl pyrrolidone (PVP), hydroxyethyl cellulose (HEC), methyl cellulose (MC), and wteen 80. The germination rate was also different according to the pelleting particulate matters. Generally, percent germination and speed of seed using the mixture of diatomaceous earth, talc and calcium carbonate were higher and faster than using other polleting materials, respectively. Thus, it should be suitable pelleting particulate matter for the pelleting of lettuce seeds. On the other hands germination of seeds using limestone, calcium oxide and benonite were low. The seed size of lettuce after pelleting was 33 times as large as the raw seed size. During the process of seed pelleting, netrient addition induced the decrement on the germination and the delay of germination speed. Also, there was differences in the germinability of pelleted seeds in accordance with the addition of nutrient sources. MS medium was generally lower than monosodium phosphate in inhibition of seed germination. Germination of pelleted seeds after priming was higher than the seeds without the treatment, and also showed the trend of early germination.

Experimental Study on Engineering Characteristic of the Waste Landfill Soil Admixed Linear (폐기물매립지 토사계 혼합 차수재의 공학적 특성에 대한 실험적 연구)

  • Chang, Yongchai;Kim, Jinchun;Jeong, Ogki
    • Journal of the Korean Geoenvironmental Society
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    • v.8 no.1
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    • pp.13-20
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    • 2007
  • Leachates resulting from the waste landfill of waste can possibly cause the second pollution, such as the underground water and environmental pollution. Accordingly, Liner layer has been installed in the reclaimed land of waste to block and purify permeation water to and prevent this second pollution. The material used as Liner layer should have water resistance and be less than permeability coefficient of $1{\times}10^{-7}$ cm/sec. As it is very difficult to get this kind of natural clay with low permeability around the field, the suitable way to get the low permeable material is to use blend with good watertighness by mixing it with natural soil which is spread in the site. While this mixed soil, which can resist water, is commonly used in the site, namely, bentonite and MCG cementious mateiral mixed soil, which is widely used as Liner layer in the reclaimed land of waste, is recognized in Liner and durability. The study was performed to find the effect of additive of the bottom liner in the waste landfill. The aim of this paper is to explain of the field application examples as well as the data of experimental research with the engineering properties of Liner layer of the reclaimed land.

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Manufacture of the Hydrophobic HY-type Zeolite-honeycomb and Its Adsorption/Desorption Characteristics for the Benzene, o-xylene, and MEK (소수성 HY-형 제올라이트제 하니컴의 제조 및 그 하니컴의 벤젠, o-xylene, MEK에 대한 흡.탈착특성)

  • Mo, Se-Young;Jeon, Dong-Hwan;Kwon, Ki-Seung;Sohn, Jong-Ryeul
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.1
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    • pp.84-96
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    • 2007
  • We performed the experiments to manufacture the hydrophobic $200cells/in^2$-zeolite honeycomb using HY-type zeolite of Si/Al ratio of 80 for separating and removing the VOCs emitted from small and medium size-plants by adsorption and to determine the drying method for the honeycomb at $105^{\circ}C$ without cracking, then measured performances of the honeycomb to adsorb the benzene, o-xylene, and MEK and to desorb the benzene and MEK saturated on the honeycomb by the nitrogen gas as the desorption gas. As a results, the good honeycomb was formed and the honeycomb was not cracked when the mixing ratio of the zeolite to bentonite to methyl cellulose to polyvinyl alcohol to glycerine to water is 100 : 8.73 : 2.18 : 4.19 : 1.38 : 126 and dried the honeycomb at $105^{\circ}C$ for 24 hours in the drying oven. The shape of the dried honeycomb was not changed after calcination, and the compressive strengths of the honeycomb after drying and calcination were 6.7 and $0.69kg/cm^2$, respectively. The adsorption efficiencies of the honeycomb for benzene, o-xylene, and MEK were $92{\sim}96%$ at the room temperature. The desorption efficiency at $180^{\circ}C$ was higher than that at $150^{\circ}C\;by\;1.5{\sim}13.8%$ depending on the flow rate of the nitrogen gas, and it was found that desorption efficiency is higher than 85% at $180^{\circ}C$ and 1.0L/min of the nitrogen gas. At $180^{\circ}C$ and 0.2 L/min, the concentration of the benzene and MEK in the used desorption gas are higher than 40,000 and 50,000ppm, respectively, so it be used as the fuel for preheating the desorption gas fed into the column in desorption cycle.

A Study on Consolidation Characteristics of Remolded Clay due to the Liquid Limit (액성한계에 따른 재성형 점토의 압밀특성에 관한 연구)

  • Lim, Hyeongmin
    • Journal of the Korean Geoenvironmental Society
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    • v.15 no.5
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    • pp.67-74
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    • 2014
  • In this study, a constant rate of strain test (CRS) and oedometer test was performed in order to study the consolidation characteristics to the liquid limit using a re-shaped clay which was preconsolidated at a constant pressure. Consolidation samples were made of kaolinite which was mixed with bentonite of 6 %, 9 %, 12 % and 15 % of it by weight and the test value of liquid limit of samples were appeared in 77 %, 84 %, 88 % and 91 % respectively. And then consolidation samples which were agitated sufficiently adding distilled water 2 times of liquid limit were preconsolidated in the condition of a constant pressure of 0.2 MPa. The oedometer test which is commonly used recently and the consolidation test of constant rate of strain which were applied in 0.001 %/min, 0.004 %/min, 0.01 %/min rate of strain according to ASTM, D4186-82 were performed and the preconsolidation pressures were compared and analyzed at 0.2 MPa preconsolidated pressure. As a result, in the case of low value of liquid limit, preconsolidation pressure was appeared same as 0.2 MPa preconsolidated pressure at the high speed strain rate, and in the case of high value of liquid limit, preconsolidation pressure was appeared same as 0.2 MPa preconsolidated pressure at the low speed strain rate.

Effect of Sand Contents on Plastic and Liquid Limits and Shear Strength of Clays (모래 함유량이 점토의 액소성한계 및 전단강도에 미치는 영향)

  • Park, Sung-Sik;Nong, Zhenzhen
    • Journal of the Korean Geotechnical Society
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    • v.30 no.2
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    • pp.65-76
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    • 2014
  • For soil improvement, sand mats or sand compaction piles are often constructed on soft marine clays. In such cases, some amounts of sand and clay are inevitably mixed. Sand or gravel often exists in the weathered soils near the slope surface. This research investigates the effect of mixing sand content on consistency limits and shear strength of clays. Firstly, sand was mixed with kaolinite or bentonite at 0, 9, 17, 23, 29, 33, 50% and then liquid and plastic limits were measured. Both plastic and liquid limits decreased as a sand content increased. The water content of clay-sand mixtures with different sand content increased by 10% or 20% step by step and then their undrained shear strength was measured using a portable vane shear device called Torvane. For all cases, undrained shear strength of clay-sand mixtures decreased rapidly until reaching a certain value. Their state changed from undrained to drained state gradually as the sand content increased, which caused their undrained shear strength to decrease. On the other hand, a series of direct shear tests were also conducted on such clay-sand mixtures to investigate the effect of sand content on cohesion and angle of internal friction. It was found from clay-sand mixtures that their cohesion decreased but angle of internal friction increased as the sand content increased.

R&D Review on the Gap Fill of an Engineered Barrier for an HLW Repository (고준위폐기물처분장 공학적방벽의 갭채움재 기술현황)

  • Lee, Jae Owan;Choi, Young-Chul;Kim, Jin-Seop;Choi, Heui-Joo
    • Tunnel and Underground Space
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    • v.24 no.6
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    • pp.405-417
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    • 2014
  • In a high-level waste repository, the gap fill of the engineered barrier is an important component that influences the performance of the buffer and backfill. This paper reviewed the overseas status of R&D on the gap fill used engineered barriers, through which the concept of the gap fill, manufacturing techniques, pellet-molding characteristics, and emplacement techniques were summarized. The concept of a gap fill differs for each country depending on its disposal type and concept. Bentonite has been considered a major material of a gap fill, and clay as an inert filler. Gap fill was used in the form of pellets, granules, or a pellet-granule blend. Pellets are manufactured through one of the following techniques: static compaction, roller compression, or extrusion-cutting. Among these techniques, countries have focused on developing advanced technologies of roller compression and extrusion-cutting techniques for industrial pellet production. The dry density and integrity of the pellet are sensitive to water content, constituent material, manufacturing technique, and pellet size, and are less sensitive to the pressure applied during the manufacturing. For the emplacement of the gap fill, pouring, pouring and tamping, and pouring with vibration techniques were used in the buffer gap of the vertical deposition hole; blowing through the use of shotcrete technology and auger placement and compaction techniques have been used in the gap of horizontal deposition hole and tunnel. However, these emplacement techniques are still technically at the beginning stage, and thus additional research and development are expected to be needed.

Immobilization and Recycling of Arsenic-Contaminated Fine Soil Cake Produced after Soil Washing Process (토양세척 후 발생하는 비소오염 탈수미세토의 불용화 및 재활용 평가)

  • Oh, Minah;Moon, SoYoung;Hyun, Min;Chae, HeeHoon;Lee, Jai-Young
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.4
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    • pp.9-16
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    • 2012
  • Standardized remediation process for the soil contaminated with arsenic is insufficient due to characteristics of its anion-mobility and speciation changed by Eh-pH of soil. One of the well-known efficient remediation processes is the modified soil washing that particle separation process by only water. However, it is required that the treatment plan for the fine soil what was discharged after modified soil washing. Therefore, this research suggests the treatment plan that the recycling method using arsenic immobilization by FeS-$H_2O_2$. The batch experiments results for the arsenic immobilization showed that the water content was at least 50%, the injection of FeS and $H_2O_2$ (assay-35%) were 8% (w/watdrybase) and 0.2 mL/10 g of fine soil respectively. Arsenic concentration with KSLT was decreased about 95.4%. The results indicated that the mixing of FeS-$H_2O_2$ was highly efficient on the immobilization of As-contaminated soil. The mixing ratio as 13% of bentonite with 3% of cement (at based on 100% of immobilized fine soil) was satisfied with standard of liner for landfill construction.

Evaluation of a Ground Heat Exchanger Appropriate for the Site of the Third Stage Construction of Incheon International Airport (인천국제공항 3단계 건설부지에 적합한 지중열교환기 시스템 평가 연구)

  • Cho, Nam-Hyun;Song, Jung-Tae;Yoon, Seok;Lee, Seung-Rae
    • Journal of the Korean Geotechnical Society
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    • v.31 no.5
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    • pp.23-33
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    • 2015
  • In the present study, a ground heat exchanger was installed for each heat source in the system at the site to evaluate ground heat conductivity, constructability, and economic feasibility; the factors considered in the study included ground heat, groundwater, fillers (such as bentonite and pea pebbles) and the shape of the heat exchange pipe (e.g., U and D-U). The aim was to determine the ground heat exchanger appropriate for the geothermal system in the 3rd-phase construction of Incheon International Airport. A comparative cost analysis of the initial costs based on the above information showed that although the initial costs of the regular vertical closed loop-II and modified vertical closed loop were lower than those of the regular vertical closed loop-I, they could not be expected to deliver high economic efficiency from the viewpoint of constructability (filler injection, heat exchange pipe insertion). The initial costs proved to be higher in the case of Geohil.

Overseas Review on the In-situ Demonstration of EBS for IN-DEBS Development (공학적방벽 현장실증 시스템 (IN-DEBS) 개발을 위한 해외 실증연구 현황 분석)

  • Lee, Minsoo;Choi, Heui-Joo;Lee, Jong-Youl;Lee, Changsoo;Lee, Jae-Owan;Kim, Inyoung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.107-119
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    • 2014
  • The worldwide Status-of-Art survey for the in-situ experiments of the engineered barrier system for HLW underground disposal was performed as a preliminary action for the design of the in-situ demonstration at KURT. Some nations, which have executed or is ongoing the in-situ experiments at their underground research facilities, were summarized in this review. The demonstration projects reviewed were TBT/Sweden-France, LOT/Sweden, HE-E/Switzerland, PRACLAY/Belgium, FEBEX/Spain, HORONOBE/Japan, and BCE/Canada. The investigated items for the projects were mainly their purposes, constitutional structures, test conditions, monitoring parameters and the measuring tools, and test results. In this review, the hardware design and the assembling of the test system were more concentrated rather than their experimental results, because the purpose of this review is to achieve the necessary information for the practical design of the in-situ experiment to be installed at KURT. A mid scale in-situ demonstration of EBS at KURT, that is called IN-DBES, will be launched right after the completion the expanding project of KURT in 2015. It is hoped that the structural design, installing methods, hardware equipments required in the establishment of IN-DEBS will be referred on this review.

Effect of Subacute Ruminal Acidosis on Plasma Concentrations of Lipopolysaccharide in Dairy Cattle (젖소에 있어 아급성제1위과산증(SARA)의 강도가 혈장 Lipopolysaccharide (LPS)의 농도에 미치는 효과)

  • Son, Hey In;Baek, Seong Gwang;Moon, Ju Yeon;Ahn, Eui-Young;Lee, Hyun-Jun;Son, Yong Suk
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.33 no.4
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    • pp.313-318
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    • 2013
  • A study was conducted to determine if subacute ruminal acidosis (SARA) induced by feeding high level of non-structural carbohydrates results in increases in lipopolysaccharides (LPS) of peripheral blood in dairy cattle. In this experiment four Holstein steers, two of which having ruminal canulae with indwelling probes placed for measuring long term pH changes, were alloted into two dietary treatments in a cross-over design, where an acidogenic diet (AD) was formulated by including high amount of non-structural carbohydrates (NSC) based on corn silage and corn flake as TMR ingredients. Data for ruminal pH change and plasma LPS concentration were compared against normal diet (ND) which contained grass hay as forage and low NSC ingredients. Feeding AD for more than 14 days to animals brought about a pH change as low as less than 5.8 for more than 4 hours, which made good contrast to ND fed animals. Decreased ruminal pH also had an effect on LPS concentrations which showed significantly higher level for AD compared with ND. Therefore, plasma LPS concentration may be used as an effective indicator to verify acidosis whether it is acute or chronic. Na-bentonite and Propylene glycol, which are frequently included in dairy TMR as additives, helped decrease ruminal pH by buffering and then ultimately alleviates SARA. Therefore, it could also be helpful to lower the occurrence of laminitis which is often caused by increased blood endotoxin (LPS) concentration.