• Transactions on Electrical and Electronic Materials
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• v.4 no.6
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• pp.13-16
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• 2003

Mn-doped $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film phosphors have been grown using a pulsed laser deposition technique under various growth conditions. The structural characterization carr~ed out on a series of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) films grown on MgO(l00) substrates usmg Zn-rich ceramic targets. Oxygen pressure was varied from 50 to 200 mTorr and Zn/Ga ratio was the function of oxygen pressure. XRD patterns showed that the lattice constants of the $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film decrease with the substitution of sulfur and selenium for the oxygen in the $ZnGa_2O_4$. Measurements of photoluminescence (PL) properties of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin films have indicated that MgO(100) is one of the most promised substrates for the growth of high quality $ZnGa_2O_{4-x}M_{x}$:$Mn^{2+}$ (M=S, Se) thin films. In particular, the incorporation of Sulfur or Selenium into $ZnGa_2O_4$ lattice could induce a remarkable increase in the intensity of PL. The increasing of green emission intensity was observed with $ZnGa_2O_{3.925}Se_{0.075}:$Mn^{2+}$ and $ZnGa_2O_{3.925}S_{0.05}$:$Mn^{2+}$ films, whose brightness was increased by a factor of 3.1 and 1.4 in comparison with that of $ZnGa_{2}O_{4}$:$Mn^{2+}$ films, respectively. These phosphors may promise for application to the flat panel displays.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.496-498
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• 2010

Purpose: Lacerations requiring formal wound closure compose a significant number of all childhood injuries presenting to the emergency department. The problem with conventional suture technique are that suture removal is quite cumbersome, especially in children. Unwanted soft tissue damage can result in the process of suture removal, which calls for sedation, stressful for both medical personnel and child. The purpose of this study is to introduce the convenient suture technique for pediatric facial lacerations. Methods: Children under the age of four, presenting to the emergency department with facial lacerations were enrolled in the study. From March 2008 to June 2009, 63 patients (41 males and 22 females) with an average age of 1.4 years were treated with our convenient suture technique using utilized a loop suspended above a double, flat tie. Clean, tension free wounds were treated with our technique, wounds with significant skin defect and concomitant fractures were excluded. Results: The Patients were followed-up in 1, 3 and 5 days postoperatively. On the third hospital visit, suture removal was done by simply cutting the loop suspended above the wound margin and gently pulling the thread with forceps. There were no significant differences in the rates of infection and dehiscence compared with conventional suture technique. Conclusion: The use of our technique was to be simple with similar operative time compared with conventional suture technique. Removal of suture materials were easy without unwanted injuries to the surrounding tissue which resulted in less discomfort for the patient and greater parental satisfaction, minimized the complications. It can be considered as a viable alternative in the repair of pediatric facial lacerations.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.196-199
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• 2008

A new grafted cactus variety, 'Dahong', Gymnocalycium mihanovichii, is hybrid crossed between '9508021' line with red and black color, and 'Jinhong', with dark red color in 2002. It was cultivated for 6 months after grafted in vitro and planted at 100 mL test tube. After grafting in vivo in 2003, the various characteristics of this was evaluated three times until 2006. It has the flat-round shape and dark red skin, and produces the daughter globes at areoles, which are arranged well at the low part of globe. In addition, it has 8~10 ribs and the gray and slant spines in body. The ability of propagation is better than 'Jinhong' to produce approximately 13.6 daughter globes.

• Journal of the Optical Society of Korea
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• v.18 no.3
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• pp.207-216
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• 2014

In this work, we report detailed numerical analysis of the near-elliptic core index-guiding triangular-lattice and square-lattice photonic crystal fiber (PCFs); where we numerically characterize the birefringence, single mode, cut-off behavior and group velocity dispersion and effective area properties. By varying geometry and examining the modal field profile we find that for the same relative values of $d/{\Lambda}$, triangular-lattice PCFs show higher birefringence whereas the square-lattice PCFs show a wider range of single-mode operation. Square-lattice PCF was found to be endlessly single-mode for higher air-filling fraction ($d/{\Lambda}$). Dispersion comparison between the two structures reveal that we need smaller lengths of triangular-lattice PCF for dispersion compensation whereas PCFs with square-lattice with nearer relative dispersion slope (RDS) can better compensate the broadband dispersion. Square-lattice PCFs show zero dispersion wavelength (ZDW) red-shifted, making it preferable for mid-IR supercontinuum generation (SCG) with highly non-linear chalcogenide material. Square-lattice PCFs show higher dispersion slope that leads to compression of the broadband, thus accumulating more power in the pulse. On the other hand, triangular-lattice PCF with flat dispersion profile can generate broader SCG. Square-lattice PCF with low Group Velocity Dispersion (GVD) at the anomalous dispersion corresponds to higher dispersion length ($L_D$) and higher degree of solitonic interaction. The effective area of square-lattice PCF is always greater than its triangular-lattice counterpart making it better suited for high power applications. We have also performed a comparison of the dispersion properties of between the symmetric-core and asymmetric-core triangular-lattice PCF. While we need smaller length of symmetric-core PCF for dispersion compensation, broadband dispersion compensation can be performed with asymmetric-core PCF. Mid-Infrared (IR) SCG can be better performed with asymmetric core PCF with compressed and high power pulse, while wider range of SCG can be performed with symmetric core PCF. Thus, this study will be extremely useful for designing/realizing fiber towards a custom application around these characteristics.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.63-71
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• 2021

Using fossil fuels in existing industrial systems causes a variety of social problems. Recently, many studies have been conducted on bio-refineries, which aim to actively utilize biomass to reduce the use of fossil fuels and solve various social problems. Among them, research using microalgae as a third-generation biomass has attracted considerable attention. Microalgae use inorganic matter to produce organic matter, and cell destruction is necessary to extract useful organic materials from microalgae. The extracted organic materials are currently used in various industrial fields. Numerous cell-destruction methods exist. We have investigated cell disruption by sonication, especially its efficiency. Ultrasound is a sound wave with frequencies above 20 kHz, and destroys cells by sending high energy through a cavitation that occurs, according to the characteristics of the sound wave. The Dunaliella salina microalgae used in this study was cultured in a flat-type photobioreactor. Experiments were performed using a batch low-frequency processing device. Logistic model was applied to analyze the results of cell-destruction experiments using ultrasound. The proper conditions for the most efficient cell destruction were OD 1.4(microalgae concentration)), 54watt(output power) and 200mL(microalgae capacity).

• Food Science of Animal Resources
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• v.43 no.3
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• pp.512-530
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• 2023

The present study evaluated the effects of fermented whey protein using kimchi lactic acid bacteria Lactobacillus casei DK211 on skeletal muscle mass, muscle strength, and physical performance in healthy middle-aged males performing regular resistance exercises. Effective protein supplementation and regular exercise are two important factors for improving muscle health. Therefore, in this study, the effects of consuming fermented whey protein twice a day were investigated and compared with that of non-fermented supplementation. Forty-eight males (average age 44.8) were randomly assigned to two groups: Fermented whey protein supplementation (FWPS) and non-fermented whey protein concentration supplementation (WPCS) groups. Each group ingested 37 g of FWPS or WPCS twice a day for eight weeks. Body composition, muscle strength, and physical performance were assessed pre- and post-intervention. Independent t-tests or chi-square tests for the categorical variables were performed for analyzing the observations. FWPS was effective in promoting the physical performance in dynamic balance measurement and muscle health, indicated through the increment in grip strength (left), upper arm circumference, and flat leg circumference from the baseline. However, similar improvements were not observed in the WPCS group. These results imply that whey protein fermented by L. casei DK211 is an effective protein supplement for enhancing muscle health in males performing regular resistance exercises.

• Journal of the Korean Wood Science and Technology
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• v.50 no.2
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• pp.134-147
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• 2022

The objective of this study is to determine the effect of fiber direction arrangement and layer composition of hybrid bamboo laminate boards on the physical and mechanical properties. The raw material used was tali bamboo (Gigantochloa apus (J.A. & J.H. Schultes) Kurs) rope in the form of flat sheets (zephyr) and falcata veneer (Paraserianthes falcataria (L) Nielsen). Zephyr bamboo was arranged in three layers using water-based isocyanate polymer (WBPI) with a glue spread rate of 300 g/m². There were variations in the substitution of the core layer with falcata veneers (hybrid) as much as two layers and using a glue spread rate of 170 g/m². The laminated bamboo board was cold-pressed at a pressure of 22.2 kgf/cm² for 1 h, and the physical and mechanical properties were evaluated. The results showed that the arrangement of the fiber direction significantly affected the dimensional stability, modulus of rupture, modulus of elasticity, shear strength, and screw withdrawal strength. However, the composition of the layers had no significant effect on the physical and mechanical properties. The bonding quality of bamboo laminate boards with WBPI was considered to be quite good, as shown by the absence of delamination in all test samples. The bamboo hybrid laminate board can be an alternative based on the physical and mechanical properties that can meet laminated board standards.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.3
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• pp.110-125
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• 2011

A number of the Bronze Age dwelling sites have been found and excavated in the Yoodoocheon, Onyangcheon and Baekseokdong basins. Two basins are located near Asan and Onyan in the Chungnam Province of South Korea. Baekseokdong is located in Cheonan, Chungnam. 207 dwelling sites are concentrated around the area of $1.3km^2$ in the Baekseokdong. 177 dwelling sites are sparse and distributed over the area of $1.3km^2$ in the Yongdoocheon and Onyangcheon basins. Most of the Bronze Age dwelling sites in those areas located on the hill. The hills have similar geomorphological environments except for slight differences in geological faces. This study analyzes geomorphological environments of the high-density residential zone of the Bronze Age in the Yoodoocheon and the Onyangcheon basins, and then compares them with the results in Baekseokdong. Study results show that high-density residential zone consists mainly of specific micro-landforms such as the Crest slope, the Crest flat and the Upper side slope, and southeast-facing aspect. A lot of Gentle slope lands were distributed in terms of terrain slope but it is far from specific geomorphological environments. This is not weighted in specific value. Our results show that the geomorphological characteristic derived from this study is major considerations to develop dwelling sites in the Bronze Age. This can be useful to discover the possible dwelling sites over other Chungnam hill regions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.3
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• pp.245-251
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• 2015

In an electrical reliability test of a printed circuit board (PCB), the impact of the micro probing pins on the PCB needs to be checked to ascertain the quality of the circuit. In this study, the impact of the dynamic movement of the probing pin on the pad was observed. As a misaligned pin can exert horizontal force on the pad of the PCB, this study focused on the behavior of a misaligned probing pin. The parameters of observation were the circular and flat edges of the probing pin. The effects of the speed of movement, diameter, and the length of projection of the probing pin were also investigated. The results demonstrated that slippage angle is strongly affected by the shape of the edge of the probing pin, and that projection length is an important factor affecting pin slippage. In contrast, the speed of movement of the probing pin was able to double the slippage angle.

• Membrane Journal
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• v.15 no.2
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• pp.114-120
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• 2005

The purpose of this study is to obtain practical information about membrane coupled $ A_2O$ system for muncipal wastewater treatment. A flat-plate microfiltration (MF) module with a pore size $0.25\;{\mu}m$ was submerged into the aeration basin and treated water was filtrated through the membrane by continuous suction with low pressure. The system was operated with synthetic wastewater to find operational parameters of internal recycle ratio and maximum MLSS showing best water quality and long-term stability. The internal recycle was defined as type 1 for aerobic to anoxic tank and type 2 for anoxic to anaerobic tank, respectively When the flux was maintained at $0.015\;m^3/m^2/hr$ (15 LMH) with 2Q type 1 internal recycle ratio, the optimal operational setting were 10 internal recycle ratio for type 2 and maximum MLSS of 11,000 mg/L among tested conditions. At this condition, removal efficiencies of BOD, CODcr, T-N and T-P showed $97.3\%,\;94.2\%,\;64.0\%,\;63.0\%$, respectively.