• KSTLE International Journal
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• v.6 no.2
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• pp.33-38
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• 2005

Submicron-scale patterns made of polymethyl methacrylate (PMMA) were fabricated on silicon-wafer using a capillarity-directed soft lithographic technique. Polyurethane acrylate (PUA) stamps (Master molds) were used to fabricate the patterns. Patterns with three different aspect ratios were fabricated by varying the holding time. The patterns fabricated were the negative replica of the master mold. The patterns so obtained were investigated for their adhesion and friction properties at nano-scale using AFM. Friction tests were conducted in the range of 0-80 nN. Glass (Borosilicate) balls of diameter 1.25 mm mounted on cantilever (Contact Mode type NPS) were used as tips. Further, micro-friction tests were performed using a ball-on-flat type micro-tribe tester, under reciprocating motion, using a soda lime ball (1 mm diameter) under a normal load of 3,000 mN. All experiments were conducted at ambient temperature ($24{\pm}1^{\circ}C$) and relative humidity ($45{\pm}5\%$). Results showed that the patterned samples exhibited superior tribological properties when compared to the silicon wafer and non-patterned sample (PMMA thin film) both at the nano and micro-scales, owing to their increased hydrophobicity and reduced real area of contact. In the case of patterns it was observed that their morphology (shape factor and size factor) was decisive in defining the real area of contact.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.103-108
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• 2013

This study was carried out to observe the effect of superheated steam combined with oven heating on the physico-chemical and sensory properties of chicken meat. Specially, chicken breasts and thighs were heated for 40 min in various heating formulations such as oven heating, superheated steam heating or a combination of two kinds of heating. In the physical properties measurement, the shear force was increased as superheated steam heating time and chicken thighs were higher than chicken breasts in all treatments (p<0.05). The highest level of water holding capacity was solely superheated steam treated chicken for 40 min (p<0.05). The $L^*$ value was decreased but $a^*$ value or $b^*$ value were increased after cooking. Chicken breast exhibited a higher colour value than chicken thigh. Superheated heating was effective to reduce heating loss as 22.64% (p<0.05). However, pH was not different depending on the heating formulation or part of the chicken meat (p>0.05). In the sensory test, the combination of 10 min oven heating and 30 min superheated steam heating was effective to create a good flavour of chicken meat. In this study, an optimum formulation was developed which was a combination of 10 min oven heating and 30 min superheated steam heating. It was more effective to improve the quality of chicken meat than the single heat treatment of chicken meat.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.49-58
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• 2010

Various alloy system, such as Cu-Sn-Ti, Cu-Ag-Ti, and Ni-B-Cr-based alloy are used for the brazing of diamond grits. However, the problem of the adhesion strength between the diamond grits and the brazed alloy is presented. The adhesion strength between the diamond grits and the melting filler alloy is predicted by the contact angle, thereby, instead of diamond grit, the study on the wettability between the graphite and the brazing alloy has been indirectly executed. In this study, Cu-13Sn-12Ti filler alloy was manufactured, and the contact angles, the shear strengths and the interfacial area between the graphites (diamond grits) and braze matrix were investigated. The contact angle was decreased on increasing holding time and temperature. The results of shear strength of the graphite joints brazed filler alloys were observed that the joints applied Cu-13Sn-12Ti alloy at brazing temperature $940^{\circ}C$ was very sound condition indicating the shear tensile value of 23.8 MPa because of existing the widest carbide(TiC) reaction layers. The micrograph of wettability of the diamond grit brazed filler alloys were observed that the brazement applied Cu-13Sn-12Ti alloy at brazing temperature $990^{\circ}C$ was very sound condition because of existing a few TiC grains in the vicinity of the TiC layers.

• Journal of Powder Materials
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• v.26 no.5
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• pp.395-404
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• 2019

Aluminum nitride (AlN) has excellent electrical insulation property, high thermal conductivity, and a low thermal expansion coefficient; therefore, it is widely used as a heat sink, heat-conductive filler, and heat dissipation substrate. However, it is well known that the AlN-based materials have disadvantages such as low sinterability and poor mechanical properties. In this study, the effects of addition of various amounts (1-6 wt.%) of sintering additives $Y_2O_3$ and $Sm_2O_3$ on the thermal and mechanical properties of AlN samples pressureless sintered at $1850^{\circ}C$ in an $N_2$ atmosphere for a holding time of 2 h are examined. All AlN samples exhibit relative densities of more than 97%. It showed that the higher thermal conductivity as the $Y_2O_3$ content increased than the $Sm_2O_3$ additive, whereas all AlN samples exhibited higher mechanical properties as $Sm_2O_3$ content increased. The formation of secondary phases by reaction of $Y_2O_3$, $Sm_2O_3$ with oxygen from AlN lattice influenced the thermal and mechanical properties of AlN samples due to the reaction of the oxygen contents in AlN lattice.

• Journal of Korean Society of Archives and Records Management
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• v.18 no.4
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• pp.205-229
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• 2018

The purpose of this study is to present a plan to collect records for the post-management of the Pyeongchang Winter Olympics, which was held in February 2018. To achieve the research objectives, the value and types of records of the 2018 Winter Olympics follow-up records were identified, and the cases of mega sports event follow-up were selected and analyzed. Based on this, the following three measures were presented to collect records related to the Pyeongchang Winter Olympics. First, records were collected based on collection methods over time. Second, records were collected based on the object and subject of recording. Third, records were collected based on subjects related to the Pyeongchang Winter Olympics. The study's result can be used to establish a Pyeongchang Winter Olympics memorial hall and to prepare a collection plan for follow-up management after holding a domestic mega sports event.

• The Journal of Advanced Prosthodontics
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• v.11 no.4
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• pp.202-208
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• 2019

PURPOSE. Fabrication of zirconia restorations with ideal mechanical properties in a short period is a great challenge for clinicians. The purpose of the study was to investigate the effect of heating rate on the mechanical and microstructural properties of monolithic zirconia. MATERIALS AND METHODS. Forty monolithic zirconia specimens were prepared from presintered monolithic zirconia blanks. All specimens were then assigned to 4 groups according to heating rate as Control, Group $15^{\circ}C$, Group $20^{\circ}C$, and Group $40^{\circ}C$. All groups were sintered according to heating rates with the sintering temperature of $1500^{\circ}C$, a holding time of 90 minutes and natural cooling. The phase composition was examined by XRD analysis, three-point bending test was conducted to examine the flexural strength, and Weibull analysis was conducted to determine weibull modulus and characteristic strength. Average grain sizes were determined by SEM analysis. One-way ANOVA test was performed at a significance level of 0.05. RESULTS. Only tetragonal phase characteristic peaks were determined on the surface of analyzed specimens. Differences among the average grain sizes of the groups were not statistically significant. The results of the three-point bending test revealed no significant differences among the flexural strength of the groups (P>.05). Weibull modulus of groups was ranging from 3.50 to 4.74. The highest and the lowest characteristic strength values were obtained in Group $20^{\circ}C$ and Control Group, respectively. CONCLUSION. Heating rate has no significant effect on the flexural strength of monolithic zirconia. Monolithic zirconia restorations can be produced in shorter sintering periods without affecting the flexural strength by modifying the heating rate.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1186-1194
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• 2019

Objective: The influence of broiler carcass scalding conditions on chicken breast meat quality parameters was investigated. Methods: Two hundred and seventy Cobb broiler chickens from 42 to 48 days old were slaughtered according to the standard industry practice and scalded in five temperature/time combinations-$T_1$, $54^{\circ}C/210s$; $T_2$, $55^{\circ}C/180s$; $T_3$, $56^{\circ}C/150s$; $T_4$, $57^{\circ}C/120s$; $T_5$, $58^{\circ}C/90s$. Results: Scalding temperature increase resulted in higher values of external and ventral lightness and in protein functionality reduction-determined by emulsification capacity and protein denaturation-in chicken breast fillets 24 h post-mortem. Protein secondary structures had conformational changes, with a decrease of the ${\alpha}$-helix and an increase of the ${\beta}$-sheet and ${\beta}$-turn proportions, mainly in $T_1$ and $T_5$ samples, determined by Fourier-transform infrared spectroscopy in an attenuated reflectance mode analysis. The chemical composition, pH, water holding capacity and Warner-Bratzler shear force did not differ among the treatments. In the fatty acid profile, the 18:1n-9 was lower in $T_5$, which suggested that the high scalding-temperature could have caused the lipid oxidation. The values of the polyunsaturated fatty acids (PUFA), such as 22:2, 20:4n-6, and 22:6n-3, were highest in the $T_5$, thus being related to the phospholipid cellular membrane collapse in this experimental condition and subsequent release of these PUFA. Conclusion: Intermediate scalding-parameters avoided the negative changes in the chicken meat quality.

• Animal Bioscience
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• v.34 no.12
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• pp.2003-2011
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• 2021

Objective: The aim of this study was to evaluate the effect of marinating turkey meat with buttermilk and acid whey on the technological traits and microbiological quality of the product. Methods: Slices of turkey meat muscles were marinated for 12 hours in buttermilk (n = 30), acid whey (n = 30) and comparatively, in lemon juice (n = 30). The control group (n = 30) consisted of unmarinated slices of turkey breast muscles. Physical parameters (pH, water holding capacity, colour L^*a^*b^*, shear force, weight loss) were assessed and quantitative and qualitative microbiological evaluation of raw and roasted products was performed. The microbiological parameters were determined as the total viable counts of mesophilic aerobic bacteria, of the Enterobacteriaceae family, and Pseudomonas spp. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Marinating turkey meat in buttermilk and whey compared to marinating in lemon juice and the control sample resulted in a higher (p<0.05) degree of yellow color saturation (b^*) and a reduction (p<0.05) in the number of mesophilic aerobic bacteria, Pseudomonas spp. and Enterobacteriaceae family as well as the number of identified mesophilic aerobic bacteria in both raw and roasted samples. The lowest (p<0.05) shear force values were found in products marinated in whey. Conclusion: The use of buttermilk and acid whey as a marinade for meat increases the microbiological safety of the product compared to marinating in lemon juice, while maintaining good technological features of the product.

• Journal of Industrial Convergence
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• v.19 no.1
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• pp.79-85
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• 2021

The purpose of this study was to investigate the existing augmented reality (AR) contents in education and to develop digital AR contents to promote the learning outcomes in nursing skills education. AR contents has been widely used in education such as children's books, coloring, or exhibition experiences, but rarely developed in nursing education. We wanted to develop AR contents on nursing skills which required memorization of complex contents. In order to improve nursing students' memorization skills, we developed AR techniques holding and executing cameras along with game elements of time and points. In order to give the effect of placing objects in front of the user's eyes, an augmented reality camera was applied, and a total of 40 levels were created to produce the sequence of nursing techniques. This study showed that learning contents in the medical field requiring expertise could be implemented as AR contents. The content developed in this study will be used as a learning aid for nursing students.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.45-53
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• 2018

Purpose: The purpose of this study was to investigate the effects of muscle activity and muscle strength according to verbal command volume during isokinetic and isometric quadricep exercises. Methods: To measure muscle activity and muscle strength, surface electrodes were attached to the participants, as they sat on a Biodex chair. The isometric exercise was performed three times, with maximum exercise at $30^{\circ}$ bending angle, based on a maximum extension state of the knee at $0^{\circ}$. The average holding time was unified to three seconds. In addition, the isokinetic exercise was performed three times, at $60^{\circ}/sec$. The verbal command ranged between 0∾60 dB and 0∾75 dB. Muscle activity was measured using surface electromyography (4D-MT, Relive, Gimhae, Korea). The Biodex System 4 was used to measure the isometric and isokinetic strength of the nodal line, and 4D-MT was used to measure muscle activity. Results: There were significant improvements in the maximal and relative muscle strengths, when the 0∾ 60 dB and 0∾75 dB verbal commands were applied with isokinetic extension/flexion (p<.05). The isokinetic exercise (0∾75 dB) group showed a significant difference in the vastus medialis oblique muscle activity change (p<.05), while the isometric exercise (0∾75 dB) group showed a significant difference in the rectus femoris muscle activity change (p<.05). Conclusions: Our results reveal that verbal commands effectively improve muscle activity and muscle strength during isokinetic and isometric quadricep exercises.