• Journal of Technologic Dentistry
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• v.21 no.1
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• pp.27-41
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• 1999

The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-30Pd-10Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at 350-$550^{\circ}C$ Age-hardening characteristic of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, energy dispersed spectra and electron probe microanalysis. Principal results are as follows ; Maximum hardening occured in two co-phases of ${\alpha}_2$ + PdCu In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase($L1_o$ type) and an Ag-rich ${\alpha}_2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu redered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}{\to}{\alpha}_1+PdCu{\to}{\alpha}_2+PdCu$ at Pd/Cu = 3 Pd element of Ag-Pd-Cu alloy is more effective dental alloy on anti-corrosion and is suitable to isothermal ageing at $450^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.370-376
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• 2005

Sarcodon aspratus is well known as a natural edible mushroom and a symbiotic mycorrhizal fungus with oaks. This study was conducted to clarify the effects of environmental conditions on the fruiting of S. aspratus on the hillslope of Wolak Mt., Jecheon city, Chungbuk, South Korea. Soil moisture and soil temperature in S. aspratus colony were measured hourly and compared with those in the non-colony soil. The mean soil moisture during the mushroom development was 14.3% in the colony soil and 16.4% in the non-colony soil. The S. aspratus colony soils showed 2.1% less soil moisture. The mean soil temperature was $16.8^{\circ}C$ in the colony soil and $16.5^{\circ}C$ in the non-colony soil. The S. asprauts colony soils showed slightly higher temperature. It is considered that more soil water was consumed and more energy was emitted during the mycelial elongation and the mushroom development. The development of S. aspratus seems similar to that of T. matsutake which is known to be considerably affected by soil moisture, daily maximum air temperature, daily minimum air temperature and daily minimum soil temperature. The season of S. aspratus development ranges from the end of August to the beginning of October. And Ellino phenomenon and its unusual change in the weather seems to affect primodia and fruiting body development. Especially if daily minimum soil temperature continues to become higher than $20^{\circ}C$, the damage of primodia and its fruiting body was frequently observed in the field plots during the last few years recently.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1157-1163
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• 2011

This study was conducted to investigate the cause of microbiological contaminants in aseptic chocolate milk and evaluate the effect of a physicochemical treatment on the growth inhibition of isolated bacterial strains. The bacterium isolated from aseptic chocolate milk was identified as Bacillus lentus and was named B. lentus M1. In the heat and pH treatment, the growth of B. lentus was inhibited at 110$^{\circ}C$ for >15 min and at pH's <5 and >10. An electrolyzed water treatment against B. lentus M1, revealed 5 mm growth past the inhibition zone. The effect of ozone gas on B. lentus M1 growth was evaluated using viable cell counts. When the initial number of B. lentus M1 was $10^2$ and $10^3$ CFU, the bacteria were completely suppressed by ozone gas treatment for 10 and 30 min, respectively. In a microwave treatment, B. lentus M1 was sterilized following microwave treatment for 1 min. As the result of ${\gamma}$-irradiation against B. lentus M1, numbers decreased as the ${\gamma}$-irradiation dosage increased. These results show the growth inhibition effects against contaminants in aseptic chocolate milk using physicochemical treatments.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.130-140
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• 2020

This study was conducted in order to closely examine about optimum shading for superior seedling production a container seedling of Tetradium daniellii, which is being increased the demand for a seedling due to being used for alternative energy, ecological restoration and honey plant. The experiment of investigating the optimum shading on T. daniellii was carried out by using plastic container types (350 ml/cavity) for the forestry facility cultivation. The shading level was treated with full sunlight and with 35%, 55%, 75% of the full sunlight. As a result of having surveyed height and root collar diameter growth of a containerized seedling in T. daniellii, a case of the shading experiment showed a noticeably high value was indicated in the full sunlight. It was surveyed that the stronger shading level leads to the lower growth value. Root development was most active in full sunlight. Dry matter production, it was investigated to be the highest in full sunlight. It was surveyed to be the similar tendency to the outcome of height and root collar diameter growth. QI, which is index of showing the quality of a seedling, stood at 0.98 in full sunlight, thereby having been investigated to be the highest. As for the chlorophyll content in a seedling, the highest chlorophyll content was indicated in the 75% shading treatment with the relatively highest shading level. The photosynthetic rate and the water use efficiency were surveyed to be the highest in full sunlight with 8.48 μmolCO₂·m^-2s^-1, 1.40 μmolCO₂·mmolm^-1H₂O, respectively. As a result of surveying the whole experiment, optimum shading level for superior seedling production a container seedling of T. daniellii is determined in full sunlight (0%). It is expected that this will be used as a basic data for mass production.

• Progress in Medical Physics
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• v.3 no.2
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• pp.1-12
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• 1992

For intraoperative radiation therapy using electron beams, a cone system to deliver a large dose to the tumor during surgical operation and to save the surrounding normal tissue should be developed and dosimetry for the cone system is necessary to find proper X-ray collimator setting as well as to get useful data for clinical use. We developed a docking type of a cone system consisting of two parts made of aluminum: holder and cone. The cones which range from 4cm to 9cm with 1cm step at 100cm SSD of photon beam are 28cm long circular tubular cylinders. The system has two 26cm long holders: one for the cones larger than or equal to 7cm diamter and another for the smaller ones than 7cm. On the side of the holder is an aperture for insertion of a lamp and mirror to observe treatment field. Depth dose curve. dose profile and output factor at dept of dose maximum. and dose distribution in water for each cone size were measured with a p-type silicone detector controlled by a linear scanner for several extra opening of X-ray collimators. For a combination of electron energy and cone size, the opening of the X-ray collimator was caused to the surface dose, depths of dose maximum and 80%, dose profile and output factor. The variation of the output factor was the most remarkable. The output factors of 9MeV electron, as an example, range from 0.637 to 1.549. The opening of X-ray collimators would cause the quantity of scattered electrons coming to the IORT cone system. which in turn would change the dose distribution as well as the output factor. Dosimetry for an IORT cone system is inevitable to minimize uncertainty in the clinical use.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.392-398
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• 2009

This study identified risk factors of cross-contamination of foodborne pathogens and established a good agricultural practice (GAP) system for an agricultural products processing center (APC) for perilla leaves. All samples were collected before and after a standard work shift at the APC, while perilla leaves were also collected after each step in the APC. In addition, the workers and their surroundings were sampled by swabbing. The total plate count (TPC) and coliform count in the water samples increased significantly (p<0.05) to 3.36 and 1.73 log CFU/mL after work, respectively. However, no Escherichia coli and Listeria monocytogenes were detected. The bacterial populations of the workers and their surroundings did not differ significantly (p${\geq}$0.05) before and after work. However, Staphylococcus aureus (<1.66 log CFU) was detected at a high rate (13-50%) in the basket, packing table, gloves and cloth. Although perilla leaves passed through the washing steps, the TPC and coliform bacterial populations on the final products were higher (p${\geq}$0.05) than those of unwashed perilla leaves, which indicates that the washing system was not functioning properly. Accordingly, a GAP system with a better washing system should be employed at this facility.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.29-38
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• 2010

A moat is a pond or waterway paved on the outside of a fortress that is one of the facilities to prevent enemy from approaching the fortress wall or classify it as the boundary space, and this study was undertaken to find out the characteristics of the moat that was existed in the East and the West from ancient time to medieval time with the following result. First, the moat in the East was installed of natural moat and artificial moat at the same time while the moat in the West had the fortress built in naturally advantageous site to use natural most substantially more. Second, the moats of Korea were smaller in scale compared to other countries (Japan, China and the Western countries). Third, the fortresses in the East were built to protect towns or royal palace while the West had the fortress to protect the residence of kings, lords, great wealthy persons and the like, and they were used jointly with the natural moat and artificial moat to defend against the infiltration of enemy. Fourth, the Pungsujiri in the Orient is one of the numerous ideologies forming the supplementary ideologic system of Korean people that could not be denied as the perception that influences on Korean people after the Silla Dynasty, and this Pungsujiri was considered when determining the location of the castle. The moat surrounding the castle had the role to keep the good energy in the castle from escaping away. Fifth, the Ha-Ha technique in the west was designed to prevent the external power from infiltration by digging the ditch on the place applicable to the boundary of the garden site, rather than the fence. While walking around along the water-side path without knowing the existence of this ditch, when the road is discovered with the cut off in the ditch, people had the exclamation without actually recognizing such astonishment. It was originally the dike for military purpose during the medieval time that was designed to look into the garden without physical boundary surrounded with the vertical fence in the garden that by having the deep ditch like shape on the boundary line of the garden which was designed to form the farm by preventing various types of cattle from coming inside the garden and bring in the garden element for farms, forestry, agricultural land and the like.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.555-564
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• 2010

Remediation process by using the bio-carrier (beads) with dead Bacillus sp. B1 and polysulfone was investigated for heavy metal contaminated groundwater. Sorption batch experiments using the bio-carrier were performed to quantify the heavy metal removal efficiencies from the contaminated solution. The analyses using SEM/EDS and TEM for the structure and the characteristic of precipitates on/inside the beads were also conducted to understand the sorption mechanism by the bio-carrier. Various amounts of freeze-dried dead Bacillus sp. B1 were mixed with polysulfone + DMF(N,N-dimethylformamide) solution to produce the bio-carrier (beads; less than 2mm in diameter) and 5% of Bacillus sp. B1 in the bio-carrier was optimal for Pb removal in the solution. The removal efficiency ratings of the bio-carrier for Pb, Cu and Cd were greater than 80% after adding 2g of bio-carrier in 50ml of aqueous solution (<10mg/L of each heavy metal concentration). Reaction time of the bio-carrier was very fast and most of the sorption reaction for heavy metals were completed within few hours. Batch experiments were duplicated at various pH conditions of aqueous solutions and Cu and Pb removal efficiencies highly maintained at wide pH ranges (pH 2-12), suggesting that the bio-carrier can be useful to clean up the acidic waste water such as AMD. From SEM/EDS and TEM analyses, it was observed that the bio-carrier was spherical shape and was overlapped by many porous layers. During the sorption experiment, Pb was crystallized on the surface of porous layers and also was mainly concentrated at the boundary of Bacillus sp. B1 stroma and polysulfone substrate, showing that the main mechanism of the bio-carrier to remove heavy metals is the sorption on/inside of the bio-carriers and the bio-carriers are excellent biosorbents for the removal of heavy metal ions from groundwater.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.304-312
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• 2013

This study was conducted to investigate the effect of total neutral detergent fiber (NDF) and forage-derived NDF (fNDF) on nutrient intake and milk production in Holstein dairy cows. Thirty-six Holstein dairy cows at weeks 4 to 20 of lactation were included in this study. The cows were arranged in a randomized complete block design and assigned to one of six diets: 1) 38% NDF with 18% fNDF (HN-HF); 2) 38% NDF with 15% fNDF (HN-MF); 3) 38% with 12% fNDF (HN-LF); 4) 34% NDF with 18% fNDF (LN-HF); 5) 34% NDF with 15% fNDF (LN-MF); and 6) 34% with 12% fNDF (LN-LF). The cows were fed a total mixed ration twice daily (07:00 and 18:00 h) and given ad libitum access to feed and water throughout the experiment. Data on the intake of nutrients (DM, NEl, CP, NDF, fNDF, NFC), milk yield, composition, fat-corrected milk (FCM), fat and protein corrected milk (FPCM), and energy corrected milk (ECM) were analyzed. Lower dietary concentrations of total NDF or fNDF resulted in an increase in DM, NEl, and NFC intake (p<0.01), milk yield (p<0.05) and a lower milk fat concentration (p<0.01). The LN treatment showed no significant differences in milk fat concentration compared to the HN however, further reduction in fNDF decreased milk fat content (p<0.01). The lowest level of milk fat was observed in the LN-LF diet group. Changes in the dietary concentrations of NDF or fNDF did not affect the concentrations of milk protein or SNF (solid not fat), although the yield of milk protein and SNF increased with higher milk yield (p<0.01). The level of fNDF influenced the level of FCM (p=0.07), as well as FPCM and ECM yield (p<0.05). A highly positive correlation between fNDF intake and milk fat concentration was observed in animals with low NDF compared to those offered high NDF. A strong correlation was also observed between milk yield and low NDF intake compared to high NDF intake.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.44-51
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• 1980

In order to find out the suitable methods that can omit the earth healing and increase the survival through improving the seedling-healing and transportable methods. Several trials with plastic vinyl have been done and its results are as follows: 1. Though P. rigitaeda seedling have been stored in the black and white vinyl sack for 35 days in the storehouse. This seedling have survived with very high percentage as Table 1. This means that the earth healing work at the nursery or planting area can be omitted if seedling sould be stored in the storehouse by using the vinyl sack. The possibilities of long-period storage in the black and white vinyl sack seem to be come from the reasons that air humidity in the sack is nearly 100% and its air temperature is only around $15^{\circ}C$ with very little difference between day and night time. This sack also can be utilized in place of the planting sack, and though this sack with seedling have been laid under direct sunshine for 1 to 2 days. Any difference between the sack stored in the storehouse has not been observed on the survival specially Table 2. 2. When the bundled seedling have been covered with the black and white vinyl instead of earth healing, even if these seedling have been laid for 18 days under the vinyl. This seedling show us high survival as Table 3. High humidity with nearly 95%, very little difference of air temperature between day and night time under the vinyl and not so big difference between out-and inside temperature could be reasons of high survival to be considered. So through covering by the black and white vinyl. The labour power for earth healing works can be saved also. 3. In order to protect the healed seedling from the direct sunshine and the eva-transpiration. Black vinyl net and reed mat could be effective for this purpose. Because vinyl net could intercept around one to third, reed mat two to third of total solar energy and also suppress more than 50% of total water loss by the transpiration.