• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.48-54
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• 2012

This study was conducted to improve the packaging technology used for Gangjung and the product's quality characteristics during storage. Packaging materials consisting of (1) IP: OPP (oriented polypropylene)/PE (polyethylene) + Paper, (2) LP1: OPP/PE + Paper, (3) LP2: OPP/PE + Can, (4) LP3: OPP/PE + Plastic, (5) BP1: OPP/PE, (6) BP2: OPP/DL/CPP (cast polypropylene), (7) BP3: PET/PE/CPP, and (8) BP4: OPP/PVDC (polyvinylidene chloride)/PE/CPP were used. The major fatty acids including 54.2% linoleic acid, 24.1% oleic acid, 11.2% palmitic acid and 6.0% linoleic acid were assessed. The packages effective in maintaining moisture were in the order of LP2, BP4 > IP > LP3, BP1, BP2 > LP1 > BP3. There were no significant differences in water content and the products in IP, BP3, and BP showed the highest level in the increase in hardness on day 60 of storage. Acid values of IP, LP1, LP2, LP3, BP1, and BP2 were maintained at <2.0 during 40 days of storage. IP, LP1, LP2 and BP1.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.378-388
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• 2016

International societies are currently working together to achieve the Climate-Smart Agriculture (CSA) initiative which aims the triple wins: (1) sustainably increasing agricultural productivity and incomes; (2) adapting and building resilience to climate change; and (3) mitigating greenhouse gases emissions. In terms of its scope and context, CSA follows the '3Nong (三農)' vision cast about 200 years ago by Dasan Jeong Yak-Yong who emphasized the triad of governance, management and monitoring towards comfortable, profitable and noble agriculture. Yet, the CSA provides the practical aims that facilitate the development of holistic indicators for quantitative evaluation and monitoring, on which decision-making support system is based. In this study, we introduce an agent-based model, i.e. Mathematical Programming Multi-Agent Systems (MP-MAS), as a tool for supporting the decision-making toward CSA. We have established the initial version of MP-MAS adapted for domestic use and present the preliminary results from an application to the rice farming case in Haenam, Korea. MP-MAS can support both farmers and policy-makers to consider diverse management options from multiple perspectives. When the modules for system resilience and carbon footprint are added, MP-MAS will serve as a robust tool that fulfills not only CSA but also Dasan's '3Nong' vision of sustainable agricultural-societal systems.

• Membrane Journal
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• v.26 no.5
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• pp.391-400
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• 2016

In this work, novel thin film composite (TFC) forward osmosis (FO) membranes are developed via interfacial polymerization on the polysulfone (PS) substrate, using TEOS as the a sol-gel reagent to form hydrophilic interlayer polymer between PS and polyamide (PA). The PS substrate was cast on a very thin polyester nonwoven to reduce membrane resistance. With the incorporation of TEOS (tetraethoxy silane) polymer in the interface between PS and PA, the formed TFC FO membrane exhibits better hydrophilicity and improved water flux, and therefore superior membrane performance. By changing the polymerization sequence of PA interfacial polymerization and TEOS sol-gel condensation, the surface properties and performance of FO membranes are changed significantly. The permeability of FO membranes were estimated using the bench-scale FO test equipment. The distribution of the polysiloxane on composite membrane and morphology are also studied with FE-SEM and EDAX. The PS_PA_TEOS membrane showed highly enhanced water flux (79.2 LMH) but reverse salt flux (RSF) value (7.10 GMH) also increased. However, the flux of PS_TEOS_PA membrane increased moderately (54.1 LMH) without increasing RSF value (1.60 GMH) compare with PS_PA membrane.

• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.99-106
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• 2001

The main objective of this study is to develop a continuity of double tee slab with two modified dap-ends to solve the problems of excessive moment, slab depth, deflection, and joint cracking in the original simply supported double tee slab systems. The modified joint is produced in a combination with two slabs with modified dap and one rectangular beam. The modified joint can be justified as following different merits. The span capacity for a design load is increased, while the deflection of the slab is decreased due to the decrease of positive moment at the center span of the slab. The joint cracking between slab and beam, which occur frequently in the original slab systems of double tee will be reduced. No more additional form work is needed to cast topping concrete for continuity. Three point loading tests are performed on the specimens with a variable of an amount of main longitudinal reinforcement to evaluate flexural and shear behavior. Following conclusions are obtained from the experimental investigation. The continuity of double tee slab effectively is provided by placing longitudinal steel reinforcement in the topping concrete over the connection, and generally leads to an increase in span capacity of double tee slabs with reduced deflection. It is more effective to control the initial cracking at the connection than that of some simply supported double tee slab systems.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.90-97
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• 2009

The purpose of the study was to examine basic property at the time of applying cast ('CS' below) and high fineness fine particle cement ('FC' below) as a stimulant to 20% substitution cement mortar of ground granulated blast-furnace slag ('BS' below) to settle a problem that early strength of BS mortar is lowered. The results were as follows. First of all, as a characteristic of fresh mortar, liquidity was reduced as much as BS substitution rate was increased. When substituting CS for BS 20%, it didn't have a large effect regardless of substitution rate. When substituting FC, it was reduced as much as substitution was increased. In the event of compressive strength, it was reduced as much as BS substitution was increased in early age. In age 28, it was somewhat increased by reflection of potential hydraulicity. With regard to improvement of early compressive/bending strength of BS 20% substitution mortar, when substituting CS, in early age, they were a little increased as much as addition rate was increased. When substituting FC, in early and 28 age, they were largely increased as much as substitution rate was increased. To settle a problem that early strength of BS 20% substitution mortar was lowered, CS substitution has a little effect and FC 25% substitution was similar to plain with only OPC. Therefore, when substituting FC 25%, it is expected that its quality will be improved.

• Journal of the Korean Ceramic Society
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• v.39 no.9
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• pp.871-877
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• 2002

Alumina slurriers, having various amount of alumina and ratio of organic additives, were prepared for tape casting. The relative viscosities were compared to investigate influence of composition on stability of the slurry and plotted as a function of powder fraction. They raised with increasing powder fraction of slurries, revealing a exponential function curve, which means that stability of slurry was not affected by amount and composition of organic additives. Cast green tapes were tested under tensile condition at room temperature. The increase in alumina ratio and binder ratio was found to decrease strain to failure of green tapes from 363% to 45% and from 68% to 25%, respectively. Tensile strength of green tapes increased abruptly with increasing alumina ratio, which showed its maximum at 1 MPa. On other hand, Tensile strength increased continuously from 0.5 MPa to 4 MPa with increasing binder ratio. Mechanical properties of them were affected seriously and lost their properties by elevating temperature from 20$^{\circ}C$ to 80$^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1264-1268
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• 1997

This study was performed to investigate the effects of aluminium treatment on renal damage in rats. Seventy five male Sprague-Dawley strains were divided into five groups; the control, 250 ppm $AlCl_3$, group, 500 ppm AlCl3 group, 250 ppm $Al_2(SO_4)_3$, group, 500 ppm $Al_2(SO_4)_3$ group and kept on the diet for 2 weeks. The body weight gain was more increased in $AlCl_3$, treated of rats but decreased in $Al_2(SO_4)_3$, treated rats than the control, on based in histophysiological examination, in $AlCl_3$, treated group, thyrodization of kidney tubular lumen and interstitial inflammatory cell infiltration, abscess formation were demonstrated and in $Al_2(SO_4)_3$, treated animals destruction of glomeruli and necrosis in kidney cortex by inflammatory cells were shownd. On the other hand, blue-pigmented cast was noted in tubules of $AlCl_3$ administration group whereas focal aluminium accumulation was noted at interstitial tissue in kidney of $Al_2(SO_4)_3$, administration group.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.20-28
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• 2006

Statement of problem: The titanium has advantages of a high biocompatibility, a corrosion resistence, low density, and cheep price, so it is focused as a substituted alloy But it is quite difficult to cast with the tranditional method due to the high melting point, reacivity with element at, elevated temperature. By using the CAD-CAM system for the crown construction, it is possible to reduce the errors while proceeding the wax-up, investing, and casting procedure Purpose: The purposes of this study were to measure the marginal adaptation of the casting titanium coping and machine-milled titanium coping according to the casting methods and the marginal configurations. Material and method: The marginal configurations were used chamfer shoulder, and beveled shoulder. The total 30 copings were used, and these are divided into 6 groups according to the manufacturing method and marginal configuration. The gap between margin of the model and the restoration was measured with 3-dimensional measuring microscope. Results: The following results were obtained; 1. casting gold coping demonstrated the best marginal seal, followed by casting titanium coping finally machine-milled titanium copings. 2. In casting titanium coping, chamfer demonstrated the best marginal seal, followed by shoulder and beveled shoulder. There was no significantly difference in shoulder and beveled shoulder. But all margin form has clinically acceptable 3. In machine-milled titanium copings, chamfer demonstrated the best marginal seal, followed by shoulder and beveled shoulder. Beveled shoulder show large and uneven marginal gap Conclusions: Above result revealed that marginal adaptation of the titanim coping is avail able in the clinical range, it can be used as an alternative metal and it is prefered especially in chamfer or shoulder margin during implant superstructure fabrication. But there should be more research on machine-milled titanium in order to use it in the clinics.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.4
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• pp.471-483
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• 1994

The purpose of this experiment was to determine the effects of various surface treatments on veneering resin to metal bond for Ni-Cr alloy. The metal surfaces were treated as follows, Group 1 : Ground with carborudum point and followed by silicoating Group 2 : Sandblasted with $50{\mu}m$ aluminum oxide and followed by silicoating Group 3. Sandblasted with $250{\mu}m$ aluminum oxide and followed by silicoating Group 4 : Beaded with $200{\mu}m$ retention structures and followed by silicoating Group 5 : Silicoated in as cast condition Group 6. Beaded with $200{\mu}m$ retention structures only All specimens were veneered with resin. Each group was consisted of 20 specimens. 10 specimens were storaged in $37^{\circ}C$ water for 3 days and the rest 10 specimens were thermocycled 1000 times at temperature of $5^{\circ}C\;to\;55^{\circ}C$. The effects of various surface treatments on the bond strength between resin and metal interface were studied by means of four-point flexure test. The specimens which bad been ground with carborundum point. sandblasted with $50{\mu}m$ and $250{\mu}m$ aluminum oxide. beaded with $200{\mu}m$ retention structures and not been treated were observed with SEM. The following results were obtained 1. The bond strength of groups 2, 3, 4 and 6 were higher than the that of groups 1 and 5 (p<0.05) in the case of being storaged in $37^{\circ}C$ water for 3 day and there was no statistically significant difference in bond strength among groups 2, 3, 4 and 6. and between groups 1 and 5 (p>0.05). 2. The bond strength of the case of being thermocycled decreased in the following orders : groups 2, group 4, group 3, group 6, group 1, group 5 and there was no statistically significant difference in bond strength among groups 2, 3 and 4, between groups 1 and 5 (p>0.05). 3. A statistical difference in bond strength of each group between storaged and being thermocycled was demonstrated for group 5 (p<0.05). 4. The treated surfaces of groups 2, 3 and 4 had more fine undercut than that of groups 1 and 5 with SEM.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.394-410
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• 1993

This study was accomplished for appreciation of the mandibular moments according to antero- posterior movement of pivot placed on the lower natural dentition. For this study, 20 subjects(male, $21\sim30$ yrs., average age 24) in the category of normal occlusion were selected, and the intraoral Vitallium clutches were cast and fabricated for each subjects. A 2-dimension PSD(Position Sensitive Detector, Hamamatsu Photonics Co., Japan) was attached to maxillary clutch in a mode of three dimensional control and LED (Light Emit Diode, Hamamatsu Photonics Co., Japan) was set up on mandibular clutch. Both clutches were set into oral cavity of each subjects and adjusted. Then the subjects were allowed to intercuspated with maximal bite force while the pivoting ball in the mid-line moving from anterior toward posterior position. The displacement scales were recorded by CCD camera(Sony, CCD-TR-705) and VCR, The conclusions were as follows : 1. When the subject was allowed to bite the metal pivoting ball in the midline of lower dentition with maximal bite force voluntarily while moving from lower central incisor to canine, 1st premolar, End premolar, 1st molar and 2nd molar. The lever actions on the pivot were revealed in all subjects. The equilibrium of moment were revealed on the pivots of 1st premolar(14 subjects), End premolar(4 subjects), and canine(2 subjects) areas. 2. The changes of loading on the TMJ according to antero-posterior positional changes of metal pivoting ball were able to recognize as follow. Compression on the TMJ was increased when the pivot moves anteriorly from the equilibrium point, and tension on the TMJ was increased when posteriorly. 3. 13 subjects were recognized their habitual chewing sides(Rights, Left8), and 7 subjects were not. During maximal biting, mandible was displaced toward their habitual chewing sides on the metal pivoting ball in the frontal plane. 4. In cephalometric analysis, the average genial angle of 20 subjects was $116.75^{\circ}$ and the average mandibular body length was 79.77mm. The equilibrium points of mandibular moment were positioned more posteriorly in the subjects having larger Genial angle than in the smaller(p<0.05). Relationships among the angle between FH plane and occlusal plane, the angle between occlusal plane and mandibular plane , and mandibular body length were not significant(p>0.05).