• Applied Microscopy
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• v.17 no.1
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• pp.161-168
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• 1987

The elongated filamentous haustorial cells, hyphae, of Cuscuta australis R. Brown penetrated into the vascular tissues of the host plant Trifolium repens L. were studied by the light and electron microscopes. The hyphae reached the host xylem were invaded into the host vessels and then they grew within the host vessels. Finally these hyphae were differentiated into the water conducting elements, xylary hyphae, by thickening of the secondary walls. The hyphae reached the host phloem were branched at the apical regions. These hyphae possessed thin-layered cytoplasm involving the typical features of sieve elements such as the parallel arrays of smooth endoplasmic reticulum, plastids with the clusters of fine starch granules, and mitochondria with the dilated cristae. It was indicated that these hyphae were differentiated into the nutrients conducting elements, phloic hyphae. The structures described were compared with those of other parasitic plants and were discussed in view of the translocation of materials from host to parasite.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.441-444
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• 2006

Nakdong river estuary is located at south-eastern coast if the Korea. Especially, Complicating topography change is generated by interaction of much sediment, wave and tide. This study is investigated into observation data of grading size distribution in the post and surface sediment characteristics is investigated into grading size analysis using sieve analysis in Nakong river estuary. As a result, mean diameter of surface sediment is distributed to front of shoal as a size with 0.1~0.2 mm and mean diameter of the last generated shoal is about 0.2~0.3 mm.

• Computers and Concrete
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• v.21 no.5
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• pp.531-538
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• 2018

The slag through sieve #4 replaced the natural fine aggregate in different proportions (0-50%) to make ready-mixed soil and slag (RMSAS). The fresh properties studied, and the concrete specimens were produced to test the hardened properties at different ages. Results showed that the workability of RMSAS decreases when the replacement increases. The unit weight increases with the replacement. The setting time extends when the replacement decreases and shortens when the replacement increases. The compressive strength, ultrasonic pulse velocity and hammer rebound value increase with the replacement. However, the high-replacement results decrease because of the expansion factor at late age. Resistivity is close and less than $20k{\Omega}-cm$. After the industrial of steelmaking by-products are processed properly, they can be used in civil engineering, not only as a substitute for natural resources and to reduce costs, but also to provide environmental protection.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.5
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• pp.355-360
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• 1997

The atmospheric concentration of dimethylsulfide (DMS), known as the predominant volatile organic. sulfur compound, is determined at subnanogram level by a combined application of non-cryogenic preconcentration method and gas chromatography with flame photometric detection (GC/FPD). The volatile DMS in air is preconcentrated using a trapping tube containing adsorbent like Molecular Sieve 5A (or gold-coated sands). The tube is then connected to the GC/FPD system via a six-way rotary valve, thermally desorbed at 40$0^{\circ}C$, separated on OV101 column, and detected by a flame photometric detector. The DMS peak elutes at about 2.5 mins and is integrated electronically. The analytical precision, if expressed in terms of relative standard error, is around 5%. The detection limit of our GC/FPD system is ca 1 ng of DMS. Details of our analytical system are presented.

• Journal of the Mineralogical Society of Korea
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• v.8 no.2
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• pp.118-125
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• 1995

경북 구룡포에 소재한 구룡광산에서 산출하는 불석(클리놉틸로라이트와 모데나이트의 집합체)에 대한 Pb2+, Cd2+, Zn2+, Co2+, Fe2+ 및 NH4+ 등 양이온의 치환성질을 알아보기 위하여 베치실험을 실시하였다. 60∼80 메쉬 및 230 메쉬의 시료를 사용하여 각각 50ppm의 농도를 가진 용액과 반응시켰다. 반응후의 용액은 AA 및 전극 (NH4+)으로 분석하여 치환양을 측정하였다. 본 연구결과 Pb2+와 NH4+가 다른 이온들보다 훨씬 높은 선택성을 보여 주었다. 불석에 대한 이온들의 선택성은 NH4+, Pb2+》Zn2+, Cu2-, Co2->Cd2-, Fe2+와 같다. 실험결과 불석시료가 용액으로부터 흡착한 양이 시료로부터 용액으로 추출된 양보다 훨씬 높게 나타나고 있는 바 이는 이온치환보다는 불석의 시브(sieve) 효과에 의한 이온흡착현상이 우세하게 일어났다는 것을 지시해준다. 본 실험은 이 불석이 중금속과 암모니아와 같은 오염물을 제거하는데 사용될 수 있음을 보여준다.

• Construction Engineering and Management
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• v.4 no.1 s.13
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• pp.48-54
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• 2003

An automated system for scanning and characterizing unbound aggregates, called the 'Laser-based Aggregate Scanning System'(LASS), has been developed at the University of Texas at Austin. The system uses a laser profiler to acquire and analyze true three-dimensional data on aggregate particles to measure various morphological properties. Tests have demonstrated that the system can rapidly and accurately measure grain size distribution and dimensional ratios, and can objectively quantify particle shape, angularity, and texture in a size invariant manner. In its present state of development, the LASS machine is a first-generation, laboratory testing device. With additional development, this technology is expected to provide high-quality, detailed information for laboratory and on-line quality control during aggregate production.

• KSBB Journal
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• v.5 no.3
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• pp.207-214
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• 1990

Growth properties of carrot hairy roots transformed by Agrobacterium rhizogenes were compared in flask and bioreactor. Oxygen transfer coefficient KLa was measured during the cultivation in bioreactor. In flask cultures, initially sucrose 30g/l was nearly exhausted after 20days. pH was dropped from initially 5.8 to 4.79 after 4 days, but it is stable after that time. Finally, after 28 days, hairy roots were grown about twelve times. In view of the results studied optimum conditions, hairy roots were maintained high growth rates in sucrose 50g/l, pH 5.8, total nitrogen 60mM. Also in bioreactor cultures, fixed stainless sieve in bottom and aerated 0.31 vvm, the results of cultivation by the use of sucrose 50g/l had grown about twenty-eight times and pH variations were liked in flask. As a results, growth rate of 1.756g fresh weight/day/g inoculum in bioreactor were higher about three times than 0.57g fresh weight/day/g inoculum in flask culture. KLa values were showed a tendency to decrease from 0.209 min-1 to 0.068 min-1.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.566.1-566
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• 2001

The most desirable healing process for endodontic therapy is apical closure by hard tissue such as dentine or cementum. Then, we estimated hard tissue conductivity of tetracalcium phosphate (4CP)/dicalcium phosphate (2CP) compound using mandibular first molars of SD rats. Residual pulp responses to the calcium phosphate compound were examined at several amputation levels of pulp. 2CP was purchased and passed through a $32-\mu\textrm{m}$ sieve. 4CP was obtained from a stoichiometric mixture of 2CP and calcium carbonate (Mol ratio: Ca/P=2.0) by the dry synthetic method at 1, 400(C for 8 hours.(omitted)

• Korean journal of food and cookery science
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• v.7 no.4
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• pp.9-13
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• 1991

Nochi is a kind of Korean traditional food made from glutinous rice or millet. This study attempted to examine the effects o( the various factors and to clarify the factors which affect the overall eating quality of Noch. The results were summarized as follows. 1. Starch content of waxy rice was 72.4% and IBC was 0.017%. 2. $\alpha$-amylase and $\beta$-amylase activity of malt were 40.13 and 8.94 units respectively. 3. Waxy rice soaked for 3 hours was ground to flour then sifted 20 mesh sieve. The mixture of waxy rice and malt was steamed for 20 minutes. 4. In sensory evaluation on varying the amount of malt and incubation time, the most favorite tendancy of the overall eating quality was at the level of 8hours incubation made by 5% addition of malt. 5. Total sugar contents, reducing sugar contents and the intensities of iodine stain at the incubation temperature of $60^{\circ}C$ were significantly different from those at $50^{\circ}C$.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.5
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• pp.125-132
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• 2000

This study was performed to evaluate the physical properties of reinforced soil mixture powder. Soil sample was prepared by passing into the standard sieve of No. 200 and reinforcement materials were calcium carbonate, quicklime and portland cement. Fineness, setting time, and compressive strength test for reinforced soil mixture powder were performed and analyzed to investigate their physical properties. The main results were summarized as follow. The compressive strength of soil mixture powder itself and most reinforced was reinforced according to increasing in the mixture rate of reinforcement and the rate of increase was remarkably higher in the cement reinforced soil moisture powder. It was appeared that the early compressive strength is considering higher in the cement reinforced soil moisture powder with 2% of moisture rate of accelerator.