• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.273-279
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• 2015

Phaeodactylum tricornutum is a model diatom that its genomic information and biological tools are well established. In this study, a gene encoding (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase (PtHDR), a terminal enzyme of the methylerythritol phosphate pathway regulating chlorophyll and carotenoid biosynthesis, was isolated from P. tricornutum. The isolated gene was cloned into pPha-T1 vector containing fcpA promoter to prepare pPha-T1-HDR plasmid. As a positive control, pPha-T1-eGFP plasmid was constructed with egfp gene. Stable nuclear transformation was carried out with these plasmids by particle bombardment method and zeocin resistant colonies of P. tricornutum were selected on f/2 agar plate. In result, transformation efficiency was evaluated according to the amount of plasmid DNA coated with gold particles. Integration of introduced plasmids was confirmed with genomic DNA of each transformant by polymerase chain reaction. The eGFP fluorescence was visible in the cytoplasm, indicating that eGFP was successively expressed in P. tricornutum system. The transcript level of exogenous Pthdr gene was evaluated with the obtained transformants. The results presented here demonstrated that introduction of Pthdr gene into P. tricornutum chromosome succeeded and expression of PtHDR was enhanced under the fcpA promoter.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.247-251
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• 2002

This study was carried out to investigate the keeping quality of market milks collected from several dairy processing companies. Microbiological, chemical, and sensory properties of Intra-high temperature(UHT) treated milks stored at 5, 10, 15t were evaluated during the storage of 154days. No significant difference during the storage was shown in bacterial counts, pH and titratable acidity. Standard plate count(SPC) was remained less than 20,000 cfu/ml after 15 day storage at 5, 10, 15$^{\circ}C$. Also, Psychrotrophic bacterial count and Coliform count were not detected or detected at low level. The pH ranged from 6.55 to 6.83 and the titratable acidity ranged from 0.13% to 0.16%. In sensory evaluation, UHT milks showed normal flavor until 10days, but thereafter off-flavor was slightly developed. Consequently, UHT milks remained in good quality when stored at 5$^{\circ}C$,10$^{\circ}C$t until 15days except sensory properties. According to this experiment, the shelf-life of UHT milk can be extended to 10 days, even though maintaining the storage temperature strictly below 10 t in milk market is not easy.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.1-9
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• 2006

Purpose: The purpose of this study was to evaluate the efficacy and substitute possibility of a newly developed flowable composite resins as a luting cement for translucent fiber post. Material & Method: Two kinds of 12 mm translucent fiber Post (D.T. Light-Post (Bisco, USA) and FRC Postec (Ivoclar vivadent, Liechtenstein) was inserted into the teflon mold (7 mm diameter, 9 mm long) and Filtek-Flow (3M ESPE. USA), a light activated flowable composite resin, was polymerized for 60 seconds through the post. Also, the post was cut from the tip to 9 mm, 6 mm, 3 mm, and Filtek-Flow was light cured according to each length. For comparison, 60 seconds light-cured and 24 hours self-cured two dual cured resin cement (Duo-cement (Bisco, USA) and 2 Panavia-F (Kuraray, Japan)) samples were prepared as control group. Also cavities (1 mm in width, 1 mm in depth and 12 mm in length) were prepared using acrylic plate and aluminum bar, and flowable composite resin was flied and light cured by the diffused light from the fiber post's side wall. The degree of polymerization was measured according to the distance from curing light using Vickers' hardness test. Result: Within the limitation of this study, the following conclusions were drawn: 1. Vickers' hardness of light cured dual cured resin cement and flowable composite resin decreased from Panavia-F, Filtek-Flow and Duo-cement accordingly (p<0.05). In the dual curing resin cement, light curing performed group showed higher surface hardness value than self cured only group (p<0.05). 2. Surface hardness ratio (light cured through fiber post /directly light cured) of D.T. Light-Post using Filtek-Flow showed about 70% in the 6 mm deep and about 50% in the 12 mm deep FRC Postec showed only 40% of surface hardness ratio. 3. Surface hardness ratio by diffused light from the post's side wall showed about 50% at 6 mm and 9 mm deep, and about 40% at 12 mm deep in D.T. Light-Post. However, FRC Postec showed about 40% at 6 mm deep, and almost no polymerization in 9 mm and 12 mm deep.

• Food Science and Preservation
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• v.20 no.2
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• pp.215-221
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• 2013

The objective of this study was to evaluate the changes in the physicochemical and microbiological characteristics of pork loin meat through microwave treatment. The microwave treatment was divided into two groups: continuing microwave treatment (CW) and holding microwave treatment (HW). The microwave treatment resulted in a whiter color (L value) and affected the a, b value. The initial pH was 5.51~5.74, but it increased to 6.32~6.51 when the pork loin samples were stored for three days. During storage for 14 days, the pH changes were not significantly different (p>0.05). The thiobarbituric-acid values of all the pork loin samples increased along with the storage period, and decreased with increasing microwave dose. The volatile basic nitrogen (VBN) content of the control was higher than those of the other samples, and the VBN content decreased along with the microwave dose. The total plate counts of the pork loin samples decreased with increasing microwave dose. The study results indicated that T2 (100 W, HW) is most effective for the safety of pork loin meat without decreasing the meat's physicochemical and microbiological characteristics.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.2
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• pp.86-91
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• 2008

Ships operating in littoral sea are likely to be subjected to accidental load such as stranding. Once she has damage on the hull structure, her ultimate strength will be reduced. This paper is to investigate the effect of the stranding damage on ultimate strength of ship structure by using a series of collapse tests. For the experiment, 720 mm $\times$720 mm in section and 900mm in length of five box-girder models with stiffeners were pre- pared. Of the five, one has no damage and faur have an diamond shaped damage which represents the shape of rock section in seabed. The damage size is different between models. Among the damaged models, the damages of 3 of them were made by cutting the plate and one by pressing to represent stranding damage. Experiments were carried out under pure bending load and the applied load and displacements were recorded. The ultimate strength is reduced as the damage size increases, as expected. The largest damaged model has the damage size of 30% of breadth and its ultimate strength is reduced by 21% than that of no damaged one. The pressed one has lower ultimate strength than cut one. This might be due to the fact that the plate around the pressed damage area effect negatively on the ultimate strength.

• Journal of Welding and Joining
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• v.30 no.2
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• pp.59-64
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• 2012

Welding is an essential process in the automotive industry. Most welding processes that are used for auto body are spot welding and $CO_2$ welding are used in a small part. In production field, $CO_2$ welding process is decreased and spot welding process is increased due to welding quality is poor and defects are occurred in $CO_2$ welding process frequently. But $CO_2$ welding process should be used at robot interference parts and closed parts where spot welding couldn't. Because of the 0.65mm ~ 2.0mm thickness steel sheet were used in the automotive industry, poor quality of welding area such as burn through and under fill were happened frequently in $CO_2$ process. In this paper, we will study about the penetration depth which gives a huge impact on burn through changing a degree of base metal, welding position and torch angle. Voltage, current and welding speed were fixed but degree of base metal, welding position and torch angle were changed. And Cold- Rolled(CR) steel sheet was used. Penetration depth was analysed by multiple regression analysis to derive approximate calculations. And reliability of approximate calculations were confirmed through additional experiments. As the results of this research, we confirmed the effect of torch and plate angle to bead shape. And we present a possibility that can simulate more accurate to weld geometry, as deduced the verification equations that has tolerance of less than 21.69%.

• Journal of Biosystems Engineering
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• v.2 no.2
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• pp.37-45
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• 1977

Solar energy is a potential source of power that offers much promise being used for low-temperature applications like drying farm crops, space heating, and water heating for domestic uses. Already much of it are being used for those purpose in foreign countries. However, very little research has been done to determine the possibility of using the solar energy in Korea. This study was conducted to develop the general prediction equation of the total radiation on a horizontal surface in Daejeon area based on 5 years 91972, Jun.1-1976. Dec.31) meteorological data (bright sunshine hours, average total horizontal radiation), and to obtain experimentally the thermal efficiency of solar air and water collectors, which will be used as a basic data of designing flat-plate solar collector system.In addition to the thermal efficiency of the collectorsthe relationship among those factors affecting it such as weather condition, orientation factor, and tilted angle of collector was analyzed. The results of this study were as follows. 1. The general predicted equation of the total radiation on a horizontal surface in Daejeon area based on bright sunshine hours was developed as $H_{av} =(1.546\frac{n}{N}-0.582)H_o$. Predicting the total radiation on a horizontal surface by the above equation was thought to be possible because to values of 0.882 was smaller than any t values at above 0.05 level on the basis of two tailed test of the difference between the calculated and the recorded values. 2.It was observed that optimum tilt angle of the collector in the summer and the autumn drying season was 13 degrees and 51 degrees respectively, these values could be obtained by adding or substracting approximately 25 degrees from the latitude of this area $(36.3^{\circ}N)$ .The relationship between orientation factor and declination of sun at suitable tilt angle of 33 degrees $(s=0.9\O)$ was shown at Fig.4. 3.The thermal efficiency of solar wdter collector was shown 13.4-51. 6% on Aug. 15 (the minimum radiation recorded) and 43.8 ~537% Aug.20 (the maximum radiation recorded), and 13.8~ 46.6 and 44.3~ 49.7 were shown on each corresponding day. 4.The thermal efficiency of the collectors according to the weather condition was shown a big difference of about 10% between the day of the maximum radiation recorded and the minimum, but the differen of efficiency between the air and the water collector was at most 2 ~ 3%. 5. Even if the efficiency of the solar water collector was a little higher than the solar air collector, for drying farm products, the solar air collector was thought to be more effective because the air heated by collector could be directly used for drying them.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.483-490
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• 2016

In plant industry, sulfur storage tank is made of steel and annular plate is connected with concrete foundation of ring wall type by anchor bolt. Due to keep sulfur at high temperature in tank by coil, sulfur storage tank is expanded larger than another tank stores fluid at room temperature. Generally, structural design of tank foundation is performed analysis with loading of temperature gradient between inner and outer surface, this method can't consider the phenomenon that load is intensively transferred to concrete foundation at anchor bolt. This means that temperature load is underestimated and causes crack of concrete near anchor bolt. In this study, evaluation formula considering temperature load transfer mechanism through anchor bolt is proposed and load acting on concrete foundation is rationally decided. For this purpose, it is analyzed variation of thermal load per various anchor bolt number using finite element model including tank annular plate and anchor bolt. Solution is proposed as specified term combining result of analysis and theoretical solution for evaluating load transferred by anchor bolt. For confirmation of validation of proposed formula, it is applied in design of sulfur storage tank at plant site, it shows that the formula can be practically applied.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.565-569
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• 2017

This research aims at measuring the changes in the dose rate of photoneutron occurring in the process of the investigation into the 10 MV photon beam with a linear accelerator. In addition, the life time of the photoneutron after the end of irradiation was to be analyzed. The photoneutron were measured with a $BF_3$ proportional counter, and the measurement results of the dose rate of the photoneutron were analyzed in 3 parts at intervals of 2 seconds. The measurement results showed that the photoneutron were generated fastest when there was no metal plate inside the radiation field and when there was a lead plate, and that, as for the time that shows the final dose rate at the level of background, the life time was about 1 minute and 40 seconds regardless of the kinds of materials. Therefore, the dose rate according to the time until the photoneutron run out was proved to be different depending on the sorts of the materials and the threshold energy. However, final life time showed similar results regardless of the kinds of the materials, it can be concluded that the kinds of materials don't get involved in the life time of photoneutron.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.807-815
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• 2015

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal $CO_2$ concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.