• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.309-317
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• 2002

The mechanical characteristics of Light-Weighted Foam Soil(LWFS) are investigated in this research. LWFS is composed of the dredged soil from offshore, cement and foam to reduce the unit-weight and increase compressive strength. For this purpose, the unconfined compression tests and triaxial compression tests are carried out on the prepared specimens of LWFS with various conditions such as initial water contents, cement contents, curing conditions and confining stresses. The test results of LWFS indicated that the stress-strain relationship and the compressive strength are strongly influenced by the cement contents rather than the intial water contents of the dredged soils. On the other hand, the stress-strain relationship from triaxial compression test has shown strain-softening behavior regardless of curing conditions. The stress-strain behavior for the various confining stress exhibited remarkable change at the boundary where the confining stress approached to the unconfined compression strength of LWFS. In order to obtain the ground improvement of the compressive strength above 200kPa, the required LWFS mixing ratio is found to be 100%~160% of the initial water contents of dredged soil and 6.6% of cement contents.

• Food Science and Preservation
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• v.11 no.4
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• pp.468-471
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• 2004

To investigate the effect of funcitional MA film 0.3 mm and control(non-pack) during 24 weeks of storage on 'Fuji' apple, the weight loss, firmness, a titratable acidity, soluble solid content(SSC $^{\circ}Brix$) and the rate of decay were measured. After 20 week storage, weight loss was $4.65\%$ in control, but $0.31\%$ in 0.03 mm funcitional MA film. The titratable acidity, soluble solid content and firmness were changed a little. The rate of decay was $4.2\%$ in control, and $1.1\%$ in funcitional MA film.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.473-476
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• 2008

The use of the recycled fine aggregate to the material of structural concrete is not easy currently because there are some problems, such as the difficulty of quality control and the badness of chemical and physical property other than river sand, crushed fine aggregate. To use of recycled fine aggregate, many researches on the recycling of recycled fine aggregate have been studying until today. However, the result of the research is little except for some results. Therefore, the purpose of this study is to confirm the possibility of use of recycled fine aggregate for raw material of plaster mortar. In this study, various tests were performed such as flow, air content, unit weight, bond strength, and compressive strength test to evaluate the effect according to the substitution of recycled concrete aggregate. The results of strength test showed that the concrete strength improved with the increase of replacement ratio of recycled fine aggregate. In the other side, flow and air content are decreased according to replacement ratio of recycled fine aggregate. The result of this study could be used as the basic data for the recycling of recycled fine aggregate.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.1-8
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• 1976

One of the most common needle leaf species used in planting in Korea is korean pine (Pinus koraiensis S. et Z.), and jack pine (Pinus banksiana Lamb.) is one of the test species for suitability. The relation of nursery bed density of 2-1 korean pine and 1-1 jack pine was studied at the Kwang Nung Nursery, Central Branch Station of Forest Research Institute, and about 40km north of Seoul. Nursery bed density of 2-1 korean pine, which ranged from 36 to 324 trees per square meters and of 1-1 jack pine, which ranged from 25 to 169 trees per square meters, had a marked effect on caliper, height, dry weight and percent and amount of plantable stock. The soil physical and chemical properties is silt plus clay, 50.55 percent; organic matter, 2.09 percent; total nitrogen, 0.13 percent; available phosphorus, 253.25 ppm; exchangeable potash, 0.46 m.e/100g; and pH, 5.58. As the density of the nursery seedling stand of 2-1 korean pine increases, the average tree height increases (Fig. 1A), but in 1-1 jack pine density do not affect to increase or decrease the average tree height. As the density of nursery bed increases, the average stem caliper (at 2cm above ground line) and dry weight decrease (Fig. 1B), but the decreasing rate is more seriously in 1-1 jack pine than 2-1 korean pine (Fig.5). As increasing the density of nursery bed, the T/R ratio of trees of the test species increase. Also the dry weight of leaf, stem and root parts are decreasing in proportion to the increase of stand density, but the drop rate of jack pine is more rapid than korean pine (table. 1) The patent facts of difference of growth characteristics between 2-1 korean pine and 1-1 jack pine were studied. These facts should be used to select the scale of stand density at the nursery bed or the plantable site. Korean pine is demanded high density, on the other hand in jack pine low density are more suitable to manage the stand density. Stands of comparatively low density had the greatest percentage of high-quality stock, and the stands of high density had less than the high quality trees of low density. An important criterion of the best density is percent and number of high-quality trees produced per square meter of bed area. Stem caliper and stem height of seedling is used in most public nurseries to sort seedling into plantable grades. The stock grade standard has set at 4.5mm caliper and 16cm height of 2-1 korean pine as the minimum desired stem caliper and height. By the result studies, the plantable stock grade standards of 2-1 korean pine used at stem height 16cm and stem caliper 4.5mm from public nurseries should be reformed to stem height 18cm and stem caliper 4.0mm by the growth characteristics and the tree distribution of stem height and caliper of relation to density. For the 2-1 korean pine, best density should be about 160 to 200 trees per square meter according to soil fertility. For the 1-1 jack pine, the suitable standard of plantable stock should be at stem height 25cm and caliper 6mm (at 2cm above ground line) and best density was about 100 to 120 trees.

• Journal of the Korean Wood Science and Technology
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• v.16 no.3
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• pp.38-47
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• 1988

표고버섯(Lentinus edodes) 균에 의한 졸참나무(Quercus serrata)골목의 미시형태적 변화를 주사형전자현미경 (SEM)을 통해 관찰하였다. 표고 재배 5년후 골목의 중량 감소율은 50%에 달했다. 구성세포중 목섬유는 표고균사에 의해 쉽게 분해되었으나 도관과 유세포는 저항성을 나타냈다. SEM 관찰 결과 표고균사는 세포내강(內腔)에서부터 세포벽을 서서히 분해 박벽화(薄壁化)시켰으며, 또한 Cell corner가 중간층보다 먼저 공격을 받아 분해 되었으나 중간층은 쉽게 분해되지 않았다. 흥미롭게도 연부후(軟腐朽)의 전형적 형태인 2차막에서의 공동(空洞)역시 백색부후균인 표고균사에 의해 형성 되었다. 이상의 관찰결과 표고균은 백색부후와 연부후균이 갖는 미시형태적 특징을 동시에 보여 주었다. 아울러 중간층 보다 Cell corner가 먼저 선택적으로 분해되며, 도관세포벽의 분해저항성을 세포벽 구성 리그닌의 화학적 특성과 연관시켜 논의했다.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.130-136
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• 1986

'Shingo' pears were seal-packaged in polyethylene (PE) film with different thickness of 0.04. 0.06, 0.07, and 0.08mm and stored for five months in an experimental storehouse with the temperature varyine 0 to $7^{\circ}C$ and relative humidity varying 86 to 89%. The atmosphere in PE film bags was modified to 5-l4% oxygen with 3-5% carbon dioxide depending on the film thickness and the storage period. Packaging of pears with PE film effectively reduced the weight loss, which resulted in good appearance after 5 months' storage, while non-packaged pears showed a slight wilt. Decay occurrence was not significantly different among the treatments. but role browning occurred a little more in packaged lots than in non-packaged lot. The sensory panel rated the pears front 0.07mm-thick bag highest in flavor, texture, and juiciness, which might be due to the high sugar content and low titratable acidity. The firmness of pear flesh decreased with the stogare time and its change was found to be highly correlated with that of cellulase activity (correlation coefficient= -0.946). Thisresult indicated that cellulase might be one of the enzymes responsible for the softening of pear fruit during storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.819-825
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• 2001

Characteristics (salt concentration, weight loss, soluble solid content, moisture content, pH, textural properties) of kakdugi radish cube (2$\times$2$\times$2 cm) were evaluated during salting. Four different radish cultivars harvested in spring were immersed into 5, 10 or 15% brine (radish : brine - 1 : 2) at 15$^{\circ}C$ for 5 hr. The time required to reach the optimum salt concentration (3.0%) was different among cultivars; in 10% brine solution, 5 hr for ‘Bakbong’and ‘9621’, and 4 hr ‘Bagkwang’ and ‘Housebommu’, in 15% brine, 3 hr for ‘Bakbong’and ‘9621’, and 2 hr for ‘Bagkwang’and ‘Housebommu’. While the highest value of weight loss of kakdugi radish cube was observed with ‘Bagkwang’, the lowest, ‘Bakbong’. There was a decrease of pH of kakdugi radish during salting ; while ‘Bakbong’ showed little change in pH, ‘Bakbong’and ‘Housebommu’ showed large decrease of pH. Hardness and fracturability decreased during salting; the highest value of hardness was observed with ‘Bagkwang’, the lowest, ‘Bagkwang’. ‘Bakbong’ has the lowest moisture content, but the highest soluble solid content, while ‘Bagkwang’and ‘Housebommu’ have the highest moisture content, but the lowest soluble solid content. There was a similarity of characteristics of kakdugi radish cube between two cultivars, ‘Bagkwang’and ‘Housebommu’.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.4
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• pp.121-128
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• 2007

The present study evaluates the resistance to sulfate attack of cement matrix with or without silica fume. The main variable was the replacement levels of silica fume. In order to introduce sulfate attack to cement matrix, mortars and pastes was exposed to sodium sulfate solution for 510 days. Visual examination, expansion and compressive strength loss of mortars in addition to characteristics of pore for the paste samples were regularly investigated. From the test results, it was clearly observed that the cement matrix with silica fume was very resistant to sulfate attack irrespective of the replacement levels of silica fume. However, the severe deterioration due to sulfate attack was found in cement matrix without silica fume.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.9-14
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• 2005

Changes of sound absorption capability and anatomical features of wood by delignification treatment was estimated. Sound absorption coefficients of wood and delignificated wood had been measured by the two microphone method and anatomical changes of delignificated wood examined by SEM observation. The sound absorption coefficients of delignificated wood generally seemed to be higher than those of normal specimen. Especially, in the frequency range of 2 to 4 KHz, they was about 50% higher than those of normal specimen. Abundant small cracks generated on the cross sectional surface of delignificated wood and the weight of delignificated wood decreased about 8% than that of normal wood. It was considered that the small cracks formed by delignification treatment behaved as a sound absorbing pore.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.632-637
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• 2017

This study was conducted to determine the minimal processing characteristics of four vegetables (brown mustard, kale, red beet and red lettuce) for wrapping (Ssam). Prior to evaluation, the vegetable leaves were cut, washed, and packaged. The texture, weight loss, browning index, pH, gas concentrations ($O_2$ and $CO_2$), microbial growth, and organoleptic qualities of the leaves were assessed at $10^{\circ}C$ for 7 days. The cutting strength of red beet was significantly different among leaves. The initial springiness of brown mustard was the lowest (0.98%). The weight loss varied between 0.24 to 4.77%, pH ranged from 6.00 to 6.95, and browning index increased to 0.95 during storage. Changes of gas composition were lower in cut leaf than whole leaf. Aerobic bacteria (4.9-8.0 log CFU/g), yeast (not detected), mold (-3.5 log CFU/g), and total coliforms (5.0-8.0 log CFU/g) were assessed in the samples. Thus, overall quality of kale and red beet leaves with minimal processing showed satisfactory results when stored for 7 days.