• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.40-46
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• 2007

This study was conducted to clarify the effects of the different substrates in terms of perlite (100%), peat moss (100%), granular rock wool (100%) and mixing perlite (50%) with peat moss (50%) on the growth responses and mineral contents of hydroponically grown Plantago asiatic in aggregate culture. Overall early plant growth such as plant height, stem diameter, number of leaves, root length, fresh and dry weight of shoot and root were increased in the order of that miked perlite and peat moss (50%:50%, v/v)>peat moss (100%)>granular rock wool (100%)>perlite (100%). Ca and Mg contents in plants became highest in the plants grown in the peat moss, however, Mg and Na in the granular rock wool. $P_2O_5$ content in plants were most increased in proportion to the plant growth increment in the peat moss (100%) and the mixing substrates of perlite and peat moss (50:50, v/v).

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.88-94
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• 2001

Physical and chemical properties, the salt accumulation and leaching of salt by water of coal fly ash ball (ash ball) were evaluated in comparison with perlite and granule rockwool (rockwool). Bulk density, particle density, solid phase, and porosity of ash ball were 0.93 g.cm$^{-3}$ , 2.29 g.cm$^{-3}$ , 40.6%, 59.4%, respectively. The bulk density of ash ball was greater, while porosity was smaller, than that of perlite and rockwool. Saturation moisture capacity was 52% in ash ball, 71% in perlite, and 90% in rockwool. Water contents after drainage for 1 hr of ash ball, perlite, and rockwool were 21%, 27%, and 80%, respectively. Water content of small granules (3-5 mm) of ash ball was 5% greater than that of large (7-15 mm) grannules. The ash ball was a weak alkali substrate with pH 7.6, but not electric conductivity (EC), of the nutrient solution supplied to ash ball slightly increased. When the absorption of mineral ions to substrates were analyzed, ash ball and RW absorbed mainly PO￣$_4$. On tomato culture, salt accumulation in ash ball substrate was similar to that in perlite. Most of the salts in the ash balls were removed by submerging the substrate eight times in distilled water. It is concluded that water holding capacity of ash ball substrate was lo as compared to other substrates, but air permeability, and water diffusion was excellent, making control of medium water content easy.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.292-299
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• 2022

This study was conducted to analyze physical and chemical properties of horticultural substrates and response of hydroponically grown two cultivars of 'Namcheon' and 'Somirang' perilla by four different substrates: coir (chip:dust = 5:5), perlite, granular rockwool, and commercial mixed substrate (cocopeat:peatmoss:vermiculite:perlite: zeolite = 50:25:10:10:5). There were no significant differences in EC and pH according to substrates. Container capacity was the greatest in granular rockwool, and it showed appropriate levels in mixed substrate and coir. Air space was higher in coir and perlite than the other treatments. Bulky density reached a proper standard in all substrates excepting coir. The leaf length and width of 'Namcheon' indicated the most in mixed substrate, though the value of 'Somirang'was greatest in coir substrate. The leaf weight of both cultivars was highest in mixed substrate, and relatively low in coir and perlite. The total yield of leaves was separated by two groups: higher group, which are mixed substrate and granular rockwool, and lower group, which are coir and perlite. There was a large gap by 28% between these two groups. Therefore, this study suggests that substrates with high water holding capacity such as mixed substrate or granular rockwool are most suitable for the hydroponic cultivation of perilla, which require sufficient moisture supply to the root zone.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.159-166
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• 1995

This experiment was aimed to investigate the growth and yield responses of hydroponically grown cucumber as affected by cultural containers and substrates using perlite and mixtures with perlite. Containers used in this experiment were bed and box made of styrofoam, PE film and Wagner pot and substrates used were perlite, peatmoss, rice hull and carbonized rice hull. The results obtained were as follows : Based on the growth and yield responses determined from the leaf area and total fruit weight, bed and box made of styrofoam was considered the best containers among tested for cucumber hydroponics. Recommendable substrates for hydroponically grown cucumber using perlite were evaluated in the order of perlite, perlite with rice hull and perlite with carbonized rice hull in styrofoam bed and box. Increase in marketable yield and decrease in abnormal fruits was observed in the mixed substrates with rice hull or carbonized rice hull when compared to perlite single media.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.19-24
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• 2010

The experiment was implemented to introduce the drainage electrode irrigation system as early as possible after transplanting in order to save the nutrient solution in a convenient way. Drainage electrode irrigation method was introduced 15, 19 or 22 days after transplanting after irrigation was firstly controlled by time clock. Time clock method was also treated as a control plot. Drainage electrode method could be adopted from 15 days after transplanting, 15 days earlier than the present introducing time. The growth and yield was better in treatments with drainage electrode method. Water and fertilizer use efficiency were the highest in the treatment of 15 days, the lowest in time clock treatment.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.04a
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• pp.101-105
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• 2002

최근 원예 분야에 무토양 상토가 매우 광범위하게 쓰이고, 그 종류도 매우 다양하다. 무토양상토는 피트모스, 코코피트, 펄라이트, 버미클라이트 등 많은 유ㆍ무기 소재의 혼합물이다. 따라서 일반토양과는 수분특성과 단위체적중량이 완전히 다르며, 일반토양분석방법으로 여러 가지 다양한 종류의 무토양상토의 물리화학적 성질을 비교 분석한다는 것은 매우 어려운 일이다. (중략)

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.59-70
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• 2010

More than 10 different cases of airline overrun accidents happened annually home and abroad in recent years. So the government put the guidelines to protect that kinds of accidents, which is named 'Runway End Safety Area'. However, the great part of airports are far from the standards, because most of the airports have been built before the guidelines. Moreover, in many cases natural obstacles, ambiance, and local area developments obstruct the extension of the runway to meet the criteria. For these reasons, the Federal Aviation Administration (FAA) recommends that the aviation fields construct 'Aircraft Rapid Arresting System(ARAS)' at the end of the runway. Many airdromes have been constructing the system and some airports have already completed the construction. In this research, our team performed a basic study about low strength perlite concrete to provide the proper material with 'ARAS'. As a result, the unit weight of the low strength perlite concrete was $4.5{\sim}6.4kN/m^3$ and uniaxial compressive strength was measured in the range of $400{\sim}1,470kN/m^2$. In addition, we tested penetration compressive strength by using CBR tester, and we observed that the strength was increased after around 60% of penetration rate. Also, 40% of penetration rate was measured through the penetration test with dump trucks.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.257-263
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• 2006

This experiment was conducted to investigate the optimal media for 'Pechika' ever-bearing strawberry grown in hydroponic culture system in summer highland. Three mixed media (1:1, v/v) of peatmoss with perlite, rice hull, and granular rockwool, and four solution strengths of EC 0.5, 0.75, 1.0 and $1.25 dS{\cdot}m^{-1}$ were tested. Root zone temperature in peatmoss+perlite media was 1 to $3^{\circ}C$ lower than in the other media. The culture medium of mixing to peat moss and perlite was most effective in producing good yield and fruit quality. The culture medium of mixing to peat moss and perlite was the highest about 1,632kg/10a to yield yearly average, but was very undulating 732 kg/10a to yield in 2004 year and 3,013kg/10a in 2003 year. The deformed fruits were increased when the solution strength was increased, especially in EC $1.25dS{\cdot}m^{-1}$. The soluble solids and the acidity content of fruits were increased with higher solution strength regardless of media. The uptake of Ca and Mg was inhibited at higher solution strength, and the uptake of N, P and K was promoted. Therefore, the culture medium of mixing to peat moss and perlite was the most suitable culture medium to product strawberry in summer, because it had the highest yield even though fruit quality among treatments was not significant.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.216-220
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• 2011

This experiment was conducted to select the right artificil soil for the purpose of artificial cultivation by effect of NaCl and different artificial soil treatment on plant growth in Salicornia herbacea that live in coastal areas. The experimental plants were planted in light and easy-to-use artificial porous soil, vermiculite, perlite, and mixed soil and were cultured for 4 month treated by hyponex solution fertilizer and 200 mM NaCl. The height, fresh weight, and dry weight of plant growth was good in a mixed soil of porous soil and pearlite. NaCl treatment on growth and chlorophyll contents, regardless of soil type decreased. Proline content of control was showed higher than salt treatment in planted by poros soil and perlite and antioxidant activity was similar value in all treatment. The antioxidant of Salicornia in different soil and salt treatment was not affected.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.3
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• pp.143-148
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• 2004

Organic and inorganic substrates commonly used in Korea include peat moss, coir, bark, rice hull, saw dust, perlite, vermiculite, rockwool granulate, clay ball, and so on. The objective of this study was to get analytical results about the physical and chemical properties of these substrates by European standard methods. Organic substrates showed different properties depending on the type, origin and manufacturing processes. Inorganic substrates showed different properties depending on the type and particle size. Further study on physical and chemical properties for more raw materials and commercially available growing media analyzed by European standard method and comparison of the results with those by Korean standard method is needed.