• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.115-120
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• 2007

An experiment was conducted to measure rooting and growth of cuttings of rose as affected by cutting length, number of leaflets and cutting position. Test plants were two cultivars of Rosa hybrida 'Red Sandra'(standard) and 'Little Marble'(miniature). Cutting length was 4, 7 or 10cm for 'Red Sandra' and 3, 5 or 7 cm for 'Little Marble'. The number of leaflets left on the five-leaflet leaf was 0, 2, 4 or 5. The cutting position on the stem was between $1{\sim}2,\;3{\sim}4,\;5{\sim}6\;or\;7{\sim}8$ nodes from the shoot tip, which have five leaflet leaves. The most efficient cutting length was 7cm in both cultivars. Treatment with all leaflets left and cutting position at $1{\sim}2$ nodes resulted in good rooting ratio for both cultivars.

• Applied Microscopy
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• v.29 no.3
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• pp.343-351
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• 1999

The structures of the fertilized egg envelope from three species, three-spot gourami (Trichogaster trichopterus), pearl gourami (Trichogaster leeri) and marble gourami (Trichogaster trichopterus trichopterus) belong to Belontiidae were observed, utilizing light, scanning and transmission electron microscopes. In all three species, the fertilized eggs were the colorless, transparent, spherical, adhesive and pelagic type. A large oil droplet was located in vitelline membrane of the fertilized egg. The egg envelopes have a single micropyle, which is thought to the pathway of sperm in the area of the animal pole. Specially, the micropyle of three-spot gourami was similar to that of marble gourami which is subspecies of three-spot gourami. An outer surface of the fertilized egg envelope was arranged by grooves in all three species. The fertilized egg envelopes consists of two distinct layers; an adhesive outer layer and an inner layer with high electron density. In conclusion, the morphological similarity of the fertilized egg, micropyle, outer surface and transverse section of the fertilized e9g envelope seems to be an indication of the Belontiidae.

• Tunnel and Underground Space
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• v.23 no.3
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• pp.180-191
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• 2013

The purpose of this research was to find an optimal quarrying for marble by analyzing the applicability and the work efficiency of a chain saw machine newly introduced in the underground Baekwoon mine. From the test results of the physical properties of Baekwoon marble, which affects the efficiency of rock cutting, it was found to have similar physical characteristics as the ones which are now being produced in the other areas in Korea. And especially it shows isotropic property, which can be thought to be advantageous as a dimensional stone. To check the long-term quality of the marble as a stone material, several tests such as corrosion resistance test and abrasion test were carried out. It was found to be vulnerable to acid rain with decrease of weight and seismic wave velocity after applying artificial rain at pH 5.6 for 50 times. The percentage of wear from abrasion test was 22.67%. The working time and cutting speed of the chain saw machine were recorded and analyzed during the test-run at the quarry. The overall work cycle was assorted into 9 unit operations and the operating time per each unit was drawn. The operating times for the two cutting patterns, which could be possibly applicable to the work site, were compared. The results indicated that the pattern B, that the cutting sequence was set to minimize the movement of the machine, showed 6% less working hours than the pattern A, which first cuts the outer boundary. With cutting pattern analysis, the ore body in the Baekwoon mine was 3 dimensionally modeled and a quarrying plan considering the existing conditions of the marble was suggested.

• 베이커리
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• no.7 s.420
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• pp.107-109
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• 2003

• Explosives and Blasting
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• v.22 no.4
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• pp.17-22
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• 2004

Boryung sandstone and Yeosan marble were thermally cracked at predetermined temperatures ranging $200^{\circ}C$ to $600^{\circ}C$. Optical microscopy was utilized to observe thermally induced cracks and physical properties such as specific gravity, effective porosity k elastic wave velocity were measured. Optical observations show that all crystal boundaries of Yeosan marble heated to $600^{\circ}C$ open and new intracrystalline cracks seem to be occurred in all crystals, but developments of thermal cracks in Boryung sandstone heated to $600^{\circ}C$ are not pronounced. From $200^{\circ}C$ upwards, effective porosity and elastic wave velocity of Yeosan marble are sharpely increased, whereas effective porosity and elastic wave velocity of Boryung sandstone are weakly increased.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.503-506
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• 2011

A new hybrid, Phalaenopsis 'Pink Marble' was made by the National Institute of Horticultural and Herbal Science, Rural Development Administration, in 2005. This hybrid was selected from self-crossed progenies of P. '21-1' (collected number) in 1999. In 2001, one line was selected based on the aspects such as flower color, leaf shape, flower stalk, and vigorous growth. Trials were conducted from 2003 to 2005 for evaluation and selection of this cultivar. 'Pink Marble' had a medium flowering habit and a dark pink spot (RHS, RPN74B) on white petal and sepal when fully opened. The number of flowers on each peduncle was 7.5, and flower diameter was 52.3 cm. The general impression of petals and sepals is a plate shape. The thick sepal could extend the long flowering time. The average length of leaf and peduncle were 16.5 cm and 6.8 cm, respectively. It had a half-erect leaf form, and was a fast-growing cultivar. This hybrid is relatively easy to clone.

• Geomechanics and Engineering
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• v.14 no.2
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• pp.203-209
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• 2018

Reliable estimation of compressive as well as tensile in-situ stresses is critical in the design and analysis of underground structures and openings in rocks. Kaiser effect technique, which uses acoustic emission from rock specimens under cyclic load, is well established for the estimation of in-situ compressive stresses. This paper investigates the Kaiser effect on marble specimens under cyclic uniaxial compressive as well as cyclic uniaxial tensile conditions. The tensile behavior was studied by means of Brazilian tests. Each specimen was tested by applying the load in four loading cycles having magnitudes of 40%, 60%, 80% and 100% of the peak stress. The experimental results confirm the presence of Kaiser effect in marble specimens under both compressive and tensile loading conditions. Kaiser effect was found to be more dominant in the first two loading cycles and started disappearing as the applied stress approached the peak stress, where felicity effect became dominant instead. This behavior was observed to be consistent under both compressive and tensile loading conditions and can be applied for the estimation of in-situ rock stresses as a function of peak rock stress. At a micromechanical level, Kaiser effect is evident when the pre-existing stress is smaller than the crack damage stress and ambiguous when pre-existing stress exceeds the crack damage stress. Upon reaching the crack damage stress, the cracks begin to propagate and coalesce in an unstable manner. Hence acoustic emission observations through Kaiser effect analysis can help to estimate the crack damage stresses reliably thereby improving the efficiency of design parameters.

• Advances in materials Research
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• v.12 no.3
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• pp.227-242
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• 2023

Polyester composites play a vital role in civil engineering applications, especially in bridge and car park structures. Therefore, the addition of waste silica-based fillers will both improve the mechanical and durability performance of composites and produce an environmentally friendly material. In this study, the mechanical performance of polyester composites was investigated experimentally and numerically by adding micro and nano-sized silica-based fillers, marble powder, silica fume and nano-silica. 24 cubes for the compression test and 18 prisms for the flexural test were produced in six different groups containing 30% marble powder, 5% silica fume and 1% nano-silica by weight. SEM/EDS testing was used to investigate the distribution of filler particles in the matrix. Experimentally collected results were used to validate tests in the Abaqus software. Additionally, the Extended Finite Element Method (XFEM) was used to estimate the fracture process for the flexural test. The results show that the added silica fume, marble powder and nano silica improves the compressive strength of polyester composites by 32-38% and the flexural tensile strength by 10-60% compared to pure polyester composite. The numerically obtained results matched well with the experimental data, demonstrating the accuracy and feasibility of the calibrated finite element model.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.309-313
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• 2007

Experiments were conducted to measure rooting and growth of rose cuttings as affected by medium composition and volume. Rosa hybrida 'Red Sandra' and 'Little Marble' were used as test plants. For medium composition test, rockwool, phenolic foam, perlite, vermiculite, peatmoss, coir and a commercial medium (Tosilee medium) were applied in single or mixed forms on the propagation bed with fog (200 sec./5 min.) installed to control the humidification time. 'Red Sandra' and 'Little Marble' cuttings were planted in 16-cell plastic pots and 72-cell plug trays, respectively. For the medium volume test, 72-cell plug trays and 16-cell or 9-cell plastic pots were used. Cuttings with an uniform node with a five-leaflet leaf was soaked in a $500mg{\cdot}L^{-1}$ IBA solution for 30 sec. A fogging system installed on the propagation bed was used for (100 sec./5 min.). Rockwool 1 : peatmoss 1 (v/v) was the most effective on growth and rooting for both cultivars and high volume of Tosilee medium and rockwool were most effective media far both cultivars.

• Magazine of the Korea Concrete Institute
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• v.13 no.4
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• pp.62-67
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• 2001