• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.337-344
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• 2015

Purpose: The purpose of present study is to examine the correlation between the accuracy of abutment preparation and the marginal adaptation of metal coping. With this view, this study compared the correlations regard to the three different manufacturing methods of selective laser sintering technique, milling and casting. Materials and methods: Two master models were made in a different way. First model with deep chamfer margin was prepared directly by a general clinician and the second model was designed by 3-D designing software program with the same abutment preparation principle and produced by computer aided manufacturing. 12 Co-Cr alloy copings were produced respectively with three different method; SLS system, CAD/CAM milling and conventional lost wax technique from each master model. The total 72 copings fully sit on the master model were stereoscopically evaluated at 40 points along the entire circumferential margin. Results: Significant differences in the absolute marginal discrepancies of Co- Cr copings from SLS system (P=.0231) and casting method (P<.0001) were shown between hand preparation model and computer designed model. However, no significant difference was found between the two model groups from milling method (P=.9962). Conclusion: Within the limitation of this study, the effect of the accuracy of abutment preparation on the marginal adaptation of Co-Cr coping is statistically significant in SLS system and casting group. The copings produced by SLS system exhibited the lowest marginal discrepancies among all groups, and the marginal gap of this method group was influenced by the accuracy of the abutment preparation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1446-1451
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• 2010

Silk sericin protein was hydrolyzed by seven proteolytic enzymes to examine the effectiveness of the hydrolysates to bind iron. The amino acid nitrogen contents of hydrolysates by Flavourzyme were higher than the others enzymes, and its iron binding capacity showed dose-dependent increase. The bioavailability of iron binding peptide from sericin hydolysates was investigated in iron-deficient rats. Three-week-old male rats were fed iron-deficient diet for three weeks. Rats were divided into four groups (DD: no treated group on iron deficient diet, DD+HI: heme-iron treated group, DD+OI: sericin-Fe, and DD+II: inorganic iron ($FeSO_4$) treated group, and then iron supplemented by injection for one week. After oral administration for one week, the iron contents of serum and liver were significantly higher in DD+OI ($4.2\;{\mu}g/mL$ and $80.1\;{\mu}g/mL$) and DD+HI ($3.2\;{\mu}g/mL$ and $70.6\;{\mu}g/mL$) than DD ($2.0\;{\mu}g/mL$ and $47.9\;{\mu}g/mL$). Hemoglobin content of treated groups was significantly higher than DD, but the significant difference among groups was not shown. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels did not show any significant difference among all groups. Binding iron to peptide from sericin hydolysates seems to improve its bioavailability and to hasten the cure of iron deficiency in experimental rat.

• Journal of Technologic Dentistry
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• v.36 no.3
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• pp.141-147
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• 2014

Purpose: Dental casting #Gr I (Co-25Cr-5Mo-3Sn-1Mn-1Si), #Gr II (Co-25Cr-5Mo-5Cu-1Mn -1Si) and #Gr III (Co-25Cr-5Mo-3Sn-5Cu-1Mn-1Si) master alloys of granule type were manufactured the same as manufacturing processes for dental casting Ni-Cr and Co-Cr-Mo based alloys of ingot type. These alloys were analyzed melting processes with heating time of high frequency induction centrifugal casting machine using infrared thermal image analyzer. Methods: These alloys were manufactured such as; alloy design, the first master alloy manufatured using vacuum arc casting machine, melting metal setting in crucible, melting in VIM, pouring in the mold of bar type, cutting the gate and runner bar and polishing. These alloys were put about 30g/charge in the ceramic crucible of high frequency induction centrifugal casting machine and heat, Infrared thermal image analyzer indicated alloys in the crucible were set and operated. Results: The melting temperatures of these alloys measuring infrared thermal image analyzer were decreased in comparison with remanium$^{(R)}$ GM 800+, vera PDI$^{TM}$, Biosil$^{(R)}$ f, WISIL$^{(R)}$ M type V, Ticonium 2000 alloys of ingot type and vera PDS$^{TM}$(Aabadent, USA), Regalloy alloys of shot type. Conclusion: Co-Cr-Mo based alloy in addition to Sn(#Gr I alloy) were decreased the melting temperature with heating time of high frequency induction centrifugal casting machine using infrared thermal image analyzer.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.225-236
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• 2016

Objectives: Nanomaterials have been used in various fields. As use of nanoproducts is increasing, workers dealing with nanomaterials are also gradually increasing. Exposure assessments for nanomaterials have been carried out for protection of worker's health in workplace. Exposure studies were mainly focused on manufacturing processes, but these studies on after-treatment processes such as refinement, weighing, and packing were insufficient. So, we investigated exposure characteristics of particles during after-treatment processes of $Al_2O_3$ fibers and Ni powders. Methods: Mass-production of Ni powder process was carried out in enclosed capture-type canopy hood. In a developing stage, $Al_2O_3$ was handled with a local ventilation unit. Exposure characteristics of particles were investigated for $Al_2O_3$ fiber and Ni powder processes during the periods of 10:00 to 16:00, 20 May 2014 and 13:00 to 16:00, 21 May 2014, respectively. Three real-time aerosol instruments were utilized in exposure assessment. A scanning mobility particle sizer(SMPS, nanoscan, model 3910, TSI) and an optical particle counter(OPC, portable aerosol spectrometer, model 1.109, Grimm) were used to determine the particle size distribution in the size range of 10-420 nm and $0.25-32{\mu}m$, respectively. In addition, a nanoparticle aerosol monitor(NAM, model 9000, TSI) was used to measure lung-deposited nanoparticle surface area. Membrane filters(isopore membrane filter, pore size of 100 nm) were also used for air sampling for the FE-SEM(model S-5000H, Hitachi) analysis using a personal sampling pump(model GilAir Plus by 2.5 L/min, Gilian). Conclusions: For Ni powder after-treatment process, only 27% increase in particle concentration was found during the process. However, for $Al_2O_3$ fiber after-treatment process, significant exposure(1.56-3.34 times) was observed during the process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1088-1096
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• 2006

The purpose of this study was to identify the service encounter blueprint by types of restaurants in order to manage moment of truth when customers who visit a restaurant encounter services. The service encounter blueprint gives an overall picture of the service provision to visualize an entire service process and its integrated structure. The blueprint is used for service process analysis technique. The random samples of 15 customers were observed by types of restaurants and the records were collected for three-days' observation. Interviews were performed by 3 managers, 3 service encounter employees, 3 cashiers, 3 cooks and 10 customers by types of restaurants. After drawing the first service blueprint, it was revised by the interview with the 3 managers and 6 service encounter employees. In this paper, restaurant service processes are reviewed and analyzed. By use of service blueprint, the processes are analyzed to find a fail point, customer wait, employee decision. As a result of making a blueprint of service encounter by types of restaurant, blueprints of fine-dining restaurants and family restaurants were similar, while fast-food restaurants showed a little difference. In particular, difference was indicated in a point where interaction of service encounter occurred. Difference was indicated depending on types of restaurants. Therefore, the efforts to improve this problem were needed. The blueprint is a map or flowchart (called a process chart in manufacturing) of all transactions constituting the service delivery process. The results showed that service encounter blueprint can be used to improve the service process in the restaurant's encounter.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.314-318
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• 2012

Most types of collagen used for biomedical applications, such as cell therapy and tissue engineering, are derived from animal tissues. Therefore, special precautions must be taken during the production of these proteins in order to assure against the possibility of the products transmitting infectious diseases to the recipients. The ability to remove and/or inactivate known and potential viral contaminants during the manufacturing process is an ever-increasingly important parameter in assessing the safety of biomedical products. The purpose of this study was to evaluate the efficacies of the 70% ethanol treatment and pepsin treatment at pH 2.0 for the inactivation of bovine viruses during the manufacture of collagen type I from bovine hides. A variety of experimental model viruses for bovine viruses including bovine herpes virus (BHV), bovine viral diarrhea virus (BVDV), bovine parainfluenza 3 virus (BPIV-3), and bovine parvovirus (BPV), were chosen for the evaluation of viral inactivation efficacy. BHV, BVDV, BPIV-3, and BPV were effectively inactivated to undetectable levels within 1 h of 70% ethanol treatment for 24 h, with log reduction factors of ${\geq}5.58$, ${\geq}5.32$, ${\geq}5.11$, and ${\geq}3.42$, respectively. BHV, BVDV, BPIV-3, and BPV were also effectively inactivated to undetectable levels within 5 days of pepsin treatment for 14 days, with the log reduction factors of ${\geq}7.08$, ${\geq}6.60$, ${\geq}5.60$, and ${\geq}3.59$, respectively. The cumulative virus reduction factors of BHV, BVDV, BPIV-3, and BPV were ${\geq}12.66$, ${\geq}11.92$, ${\geq}10.71$, and ${\geq}7.01$. These results indicate that the production process for collagen type I from bovine hides has a sufficient virus-reducing capacity to achieve a high margin of virus safety.

• Food Science and Preservation
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• v.16 no.6
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• pp.875-883
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• 2009

We investigated the effects of manufacturing method on the quality of beef jerky using electron micrography. Six types of beef jerky were prepared by the addition of sugar (A), licorice (B), one of three kinds of spice extract (clove: C, fennel fruit: D, and Chungyang green pepper extract: E), or a mixture of all spice extracts (F). Microstructural changes in beef jerky during preparation by drying, with respect to drying method and the nature of the added spice extract, were observed by scanning electron micrography (SEM) and transmission electron micrography (TEM). The latter technique showed that the microstructure of fresh meat showed actin and myosin in myofibril lines, and also mitochondria and inner membranes. Beef muscle structure was broken at many myofibril lines and decomposition of inner membrane material was evident after seasoning. SEM of air-blast dried beef jerky with added medicinal herb extracts showed both large spaces and regular myofibrils, whereas hot air-dried beef jerky had no spaces and the muscle myofibrils were still evident. After review of all available micrographs from SEM and TEM, we concluded that use of medicinal herb extracts could be helpful in preserving the muscle myofibril structure during drying, and the air-blast drying method is recommended to optimize the textural quality characteristics of beef jerky.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.50-63
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• 2007

The development of domestic plant specific emission factors is very important to estimate reliable national emissions management. This study, for the reason, was carried out to obtain advances emission factor for Carbon Dioxide ($CO_2$) by source-specific emission tests from the iron and steel industry sector which is well known as one of the major sources of greenhouse gases ($CO_2$). Emission factors estimated in this study were compared with those of IPCC for evaluation and they were found to be of similar level in the case of $CO_2$. There was no good information available on $CO_2$ plant specific emission factors from the iron and steel industry in Korea so far. The major emission sources of $CO_2$ examined from the iron and steel manufacturing precesses were a hot blast stove, coke oven, sintering furnace, electric arc furnace, heating furnace, and so on. In this study, the concentration of $CO_2$ from the hot blast stove process was the highest among all processes. The $CO_2$ emission factors for a ton of Steel and Iron products (using B-C oil) were estimated to be 0.315 $CO_2$ tonne (by Tier 3 method) and 4.89 $CO_2$ tonne. In addition, emission factor of $CO_2$ for heating furnace process was the highest among all process. Emission factors estimated in this study were compared with those of IPCC for evaluation and they were found to be of similar level in the case of $CO_2$.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2430-2434
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• 2005

Automatic FPC punching instrument for the improvement of working condition and cost saving is introduced in this paper. FPC(flexible printed circuit) is used to detect the contact position of K/B and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, the accuracy of the punching degree is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used for the sake of cost down instead of using high quality vision systems for the FA. 3D Mechanical design tool(Pro/E) is used to manage the exact tolerance circumstances and avoid design failures. Simulation is performed to make the complete vision based punching machine before assembly, and this procedure led to the manufacturing cost saving. As the image processing algorithms, dilation, erosion, and threshold calculation is applied to obtain an exact center position from the FPC print marks. These image processing algorithms made the original images having various noises have clean binary pixels which is easy to calculate the center position of print marks. Moment and Least square method are used to calculate the center position of objects. In this development circumstance, Moment method was superior to the Least square one at the calculation of speed and against noise. Main control panel is programmed by Visual C++ and graphical Active X for the whole management of vision based automatic punching machine. Operating modes like manual, calibration, and automatic mode are added to the main control panel for the compensation of bad FPC print conditions and mechanical tolerance occurring in the case of punch and die reassembly. Test algorithms and programs showed good results to the designed automatic punching system and led to the increase of productivity and huge cost down to law material like FPC by avoiding bad quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1187-1193
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• 2010

To elongate the shelf-life of Angelica keiskei and Brassica loeracea var. acephala vegetable juices, UV irradiation was used and the changes of antioxidant activity and nitrite scavenging ability were investigated. The content of polyphenols of vegetable juices were slightly reduced by UV treatment and/or storage period. The DPPH radical-scavenging activities of the vegetable juices treated by UV were higher than that of control but were not changed during storage. However, $ABTS{\cdot}^+$ reducing activities of the vegetable juices were reduced by UV treatment. The $ABTS{\cdot}^+$ reducing activity of Brassica loeracea var. acephala juice was lower when the flow rate was slower. The ferrous ion chelating effects of Angelica keiskei vegetable juices were reduced by UV treatment. In contrast, the ferrous ion chelating effects of Brassica loeracea var. acephala vegetable juices were not different from those of right after manufacturing. The ferrous ion chelating effects on both vegetable juices increased during storage periods. The inhibitory activity of lipid oxidation was decreased slightly by UV treatment on vegetable juices. The nitrite scavenging ability of Angelica keiskei and Brassica loeracea var. acephala vegetable juices treated by UV irradiation was not different from that of control. The nitrate scavenging abilities of vegetable juices in pH 1.2 were higher than those in pH 3.0 and 4.2.