• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.394-402
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• 2013

The new complex catalysts were synthesized by the reaction of titanium compounds (titanium chloride or titanium butoxide) and diamines in this work, and they showed very high catalytic activities for the cyclododecatriene (CDT) synthesis from 1,3-butadiene through trimerization. CDT synthetic reaction was performed in an autoclave reactor, and the effects of reaction temperature, type of catalyst, catalyst amount added into the system, the mole ratio of Al/Ti and immobilization method were investigated on the yield of product CDT. The titanium complex catalyst combined to diamine with 1:1 ratio showed high selectivity to CDT more than 90%. The ratio of TTT-CDT/TTC-CDT isomers in the product revealed as different values, depending on the type of diamine combined to titanium and Ti/diamine ratios. Those homogeneous complexes could be used as a heterogenized catalyst after anchoring on the supports, and the immobilized titanium catalyst retained the catalytic activities for several times in the recycled reactions without leaching. The carbon support containing titanium has exhibited superior activity to the silica support. Especially, when the titanium complex was anchored on the support which was fabricated by the hydrolysis of tripropylaminosilane itself, the resulting titanium catalyst showed the highest BD conversion and CDT selectivity.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.57-65
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• 2007

Earthquake is one of the factors to affect the stability of geotechnical structures. Numerous past earthquakes have shown that earthquakes have taught that damage of soil structures could occur on fine soils as well as coarse soils. For that reason, earthquake-induced decreasing tendency for strength on both coarse and fine soils has been investigated using direct simple shear (DSS) tests in laboratory. Based on the testing results the decreasing tendency for strength on coarse and fine soils is clearly identified in terms of the concept of volume decrease potential and plasticity index, respectively. Most of the soils except the weathered soil have shown similar reduction tendency of strength with the increasing number of cycles. Liquefaction strength of coarse and fine soils appears to decrease with the increment of volume decrease potential and the decrement of plasticity index, respectively. Reduction of strength on the weathered soil is particularly remarkable rather than others, which might be owing to the collapse phenomenon. From the DSS test results for soils, proposed is a simple method to evaluate strength decrement with the increasing number of cycles, and it can help estimate decrement of strength with the number of cycles easily.

• The Korean Journal of Cytopathology
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• v.19 no.1
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• pp.34-40
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• 2008

Fine needle aspiration (FNA) cytology of the breast is a useful method for diagnosing breast lesions. Yet making the definite diagnosis with performing FNA is limited by some problems, such as the low cellularity, the poor preservation and the obscuring background. Recent studies have found that liquid-based cytology solves such problems, but it is an expensive method and it is limited by the loss of the background information. The purpose of this study is to compare the Liqui-$PREP^{TM}$, a new manual liquid-based method of cytology, and the conventional smears for analyzing breast FNA cytology materials. A total of 31 randomized FNA specimens of breast were studied. In each case, both the conventional smears and the Liqui-$PREP^{TM}$ method were performed, and the smears were evaluated for cellularity, cellular preservation, the background, the cytologic features and the architectural arrangement. The cellularity and architectural arrangement were equal for both preparations. The Liqui-$PREP^{TM}$ specimens showed better cellular preservation, loss of the obscuring background, no overlapping of cells and a smaller area to screen compared with the conventional smears. Moreover, it has the potential advantages of being able to use the remaining specimens for immunohistochemical study and ploidy analysis, and it can reduce the costs for preparation compared with the other liquid-based methods of cytology. But some background information is lost in the Liqui-$PREP^{TM}$ specimens, the same as the other liquid-based methods of cytology. In conclusion, the Liqui-$PREP^{TM}$ and conventional smears showed good correlation, but they have their respective advantages and disadvantages. These results suggest that Liqui-$PREP^{TM}$ can contribute to making the accurate diagnosis with performing breast FNA cytology when it is used along with other methods.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.175-190
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• 2006

The term mycoherbicide started in 1970, but its interest heightened due to increase costs of chemical herbicides. A classical biocontrol agent is expected to become a permanent part of its new environment and do no harm to it. Contemporary biological control agent(BCA) must be produced by artificial culture and could be applied like chemical herbicides over weeds. BCA is different from the classical approach in that it released through natural spread. To date 26 species of fungi are used as classical BCA against 26 species of weeds in seven countries. There are a number of examples of pathogens attacking non-target plants. But through risk assessments which include understanding the taxonomy, biology and ecology, the target and non-target species, it will be safe to introduce of exotic pathogens to control weeds. But pathogens have not been successfully used in practice. Many mycoherbicides show potential in laboratories, but are ineffective in the field and not consistent from year to year or field to field. There is also a lack of understanding humidity, dew formation and temperature and their effects on suppression of weeds by plant pathogens. Potential pathogen must be selected as a BCA. Previous studies suggest that these pathogens must (1) produce abundant and durable inoculum in artifical culture, (2) be genetically stable and weed specific and (3) kill weeds in control. A granular preparation of mycoherbicide into sodium alginate is lighter than liquids and less bulky than organic matter. Gel forms have also been used.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.392-399
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• 2007

This study was carried out to assess optimum conditions of peatmoss-based substrates for red pepper plug seedlings. Peatmoss-based substrates prepared by mixing of peatmoss with vermiculite, perlite, rice hull and zeolite at various mixing ratios were used for growing pepper plug seedlings. The physical and chemical properties of the peatmoss substrate were analyzed by the CEN(European committee for standardization) method. Fresh and dry weights (shoot, root), leaf area, root length and T/R ratio (dry shoot weight/dry root weight) were determined at 55 days after sowing. The results showed that the growing media PVSZ 6 (peatmoss:silver vermiculite: zeolite=6:3.9:0.1) and PVGZ 6 (peatmoss:gold vermiculite: zeolite=6:3.9:0.1) can successfully be used for red pepper plug seedlings judging from dry weight and T/R ratio of the plug seedlings. The optimal ranges of total pore space, water volume, air volume, easily available water content and water buffering capacity of the peatmoss based growing media for pepper plug seedlings were 87~93%, 52~71%, 20~41%, 10~37% and 0.6~10%, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.369-376
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• 2007

This experiment was carried out to investigate optimum conditions of coir-based substrates for the red pepper plug seedlings. Eleven different coir based substrates prepared by mixing of coir, vermiculite, rice hull, perlite, zeolite, mixed at different ratios were tested. The physical and chemical properties of the substrates were analyzed by the CEN (European committee for standardization) method. Fresh and dry weights of shoot and root, leaf area, root length, and T/R ratio (dry shoot weight/dry root weight) were determined at 55 days after sowing. The results showed that the growing media CRZ 8(coir:rice hull: vermiculite=8:1.9:0.1) and CVSZ 6(coir:silver vermiculite: zeolite=6:3.9:0.1) can successfully be used for pepper plug seedlings judging from dry weight and T/R ratio of the plug seedlings. The optimal range of total pore space, water volume, air volume, easily available water content and water buffering capacity of the coir-based growing substrates for pepper plug seedlings were in the range of 92~94%, 52~60%, 32~43%, 18~21%, and 0.9~8%, respectively.

• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.51-60
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• 2011

Electrical resistivity is applied for understanding details about layers and obtaining basic properties of soils to various measurement devices. The objective of this study is development of TRP(Temperature-compensated Resistivity Probe), analysis about effects of temperature changes during cone penetration test, and observation of characteristics of cone penetration. In order to observation of temperature changes according to a diameter difference of resistivity cone probe, the cone which has wedge type cone tip is made to two types, 2mm and 5mm. Temperature sensor is attached at 15mm below from cone tip because of an electrical interference with elecrical resistance probe. Delectrical connector is used to prevent electric disturbance between motor type penetrating machine and electrical resistivity cone probe. Application tests are carried out in acrylic cell whose diameter is 30cm with uniform Jumunjin sand according to densification caused by blows. The test results indicate that the temperature is increased uniformly during penetration and a tendency, characteristics of cone penetration, is discovered during altering state of soils. This study suggests that the temperature effects and characteristics of penetration should be considered in penetrating tests in order to conduct an accurate ground investigation using TRP(Temperature-compensated Resistivity Probe).

• Journal of the Korean Geotechnical Society
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• v.37 no.12
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• pp.73-87
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• 2021

Pile-supported wharf is a structure that can transmit and receive cargo, and it is mainly installed on saturated inclined ground. In the seismic design of these structures, the codes suggest using the response spectrum analysis method as a preliminary design method. However, guideline on modeling method for pile-supported wharf installed in saturated soil is lacking. Therefore, in this study, the dynamic centrifuge model test and response spectrum analysis were performed to evaluate the seismic performance of pile-supported wharf installed into the saturated soil. For the test, some sections (3×3 pile group) among the pile-supported wharf were selected, and they were classified into two model (dry and saturated sand model). Then the response spectrum analysis was performed by using the soil spring method to the test model. As a result of test and analysis, the m om ent difference occurred within a m axim um of 51% in the dry sand m odel and the saturated sand model where liquefaction does not occur, and it was found that the pile moment by depth was properly simulated. Therefore, in the case of these models, it is appropriate to perform the modeling using the Terzaghi (1955) constant of horizontal subgrade reaction (n_h)

• Korean journal of applied entomology
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• v.61 no.4
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• pp.675-688
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• 2022

Produced by steaming mature silkworms, HongJam is a natural functional food with various health-promoting effects. The current standard HongJam production protocol involves freezing and freeze-drying steamed mature silkworms for convenient long-term storage and/or selling it to customers. However, freeze-drying HongJam requires a range of processes and costs, which have contributed to its high resale value. In this study, we found that the cost of manufacturing HongJam powder could be reduced by homogenizing steamed mature silkworms using a high-speed blender and digital homogenizer, followed by spray drying. After the homogenized HongJam solution was digested by directly adding food-graded proteases, food-graded protease-digested homogenized HongJam solution was spray-dried. Food-graded digested protease or non-digested homogenized HongJam solutions could be used to produce food for special medical use for patients with general or specific diseases. This more efficient HongJam processing protocol proposed in this study can facilitate the development of sericulture farms and related industries by reducing the production costs of HongJam and its associated products.

• Nuclear Engineering and Technology
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• v.25 no.1
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• pp.91-101
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• 1993

To predict accurately the thermal hydraulic behavior of light water reactors during normal or abnormal operation, the accurate estimation of the void distribution is required. Up to date, many techniques for predicting void fraction of two-phase flow systems have been suggested. Among these techniques, the drift-flux model is widely used because of its exact calculation ability and simplicity. However, to get more accurate prediction of void fraction using drift-flux model, slip and flow regime effects must be considered more properly In the drift-flux method, these two effects are accounted for by two drift-flux parameters ; $C_{o}$ and (equation omitted). At earlier stage, $C_{o}$ is measured in a circular tube. In this study, $C_{o}$ is experimentally determined by measuring local void fraction and vapor velocity distribution in a rectangular subchannel having 4 heating rods which simulates nuclear subchannels. The measurements are peformed with two-electrical conductivity probes which are known to be adequate for measuring local parameters. The experiments are performed at low flow rate and the system pressure less than 3 atmo spheric pressure. In this experiment, (equation omitted), is not measured, but quoted from well-known empirical correlation to formulate $C_{o}$. Finally, $C_{o}$ is expressed as a function of channel averaged void fraction. fraction.