• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.582-591
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• 2009

The pyramid graph is an interconnection network topology based on regular square mesh and tree structures. In this paper, we adopt a strategy of classification into two disjoint groups of edges in regular square mesh as a base sub-graph constituting of each layer in the pyramid graph. Edge set in the mesh can be divided into two disjoint sub-sets called as NPC(represents candidate edge for neighbor-parent) and SPC(represents candidate edge for shared-parent) whether the parents vertices adjacent to two end vertices of the corresponding edge have a relation of neighbor or shared in the upper layer of pyramid graph. In addition, we also introduce a notion of shrink graph to focus only on the NPC-edges by hiding SPC-edges in the original graph within the shrunk super-vertex on the resulting graph. In this paper, we analyze that the lower and upper bound on the number of NPC-edges in a Hamiltonian cycle constructed on $2^n\times2^n$ mesh is $2^{2n-2}$ and $3*(2^{2n-2}-2^{n-1})$ respectively. By expanding this result into the pyramid graph, we also prove that the maximum number of NPC-edges containable in a Hamiltonian cycle is $4^{n-1}-3*2^{n-1}$-2n+7 in the n-dimensional pyramid.

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.39-45
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• 2015

$La_2W_3O_{12}:Eu^{3+}$ phosphors were prepared by solid state reaction method. The crystal structure was characterized by XRD pattern and ICSD card (78180). Luminescence properties of $La_2W_3O_{12}:Eu^{3+}$ are investigated by optical and laser-excitation spectroscopy in which emission and excitation spectra and time-resolved spectra are measured. The 1 mol % $Eu^{3+}$-doped $La_2W_3O_{12}$ phosphor exhibits broad excitation band peaking at 286 nm due to the ligand-to-metal charge transfer transition. The excitation lines due to the $^7F_0{\rightarrow}{^5D_4},{^5D_4},{^5L_6},{^5G_4},{^5D_3},{^5D_2}$ transitions of $Eu^{3+}$ are observed in the wavelength region 350-500 nm. The strong line emission is observed at 618 nm corresponding to the due to the $^5D_0{\rightarrow}^7F_2$ transition. The lifetime of 618 nm emission decreases with increasing temperature as 7 K ($114{\mu}s$), 100 K ($94{\mu}s$), 200 K ($10{\mu}s$) and 300 K ($0.5{\mu}s$).

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.491-495
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• 2005

In partial thickness burn injuries, silver sulfadiazine cream 1%(SSD, $Silvadene^{(R)}$) is the most commonly used topical agent worldwide. But silver sulfadiazine cream 1% has no exudate absorption property. Usually after escar is removed from wound surface, $Silvadene^{(R)}$ is changed to saline wet gauze dressing to promote epithelization. $Aquacel^{(R)}$(ConvaTec, UK) is a 100% sodium carboxymethylcellulose Hydrofiber material. It absorbs exudates directly into the hydrofibers by vertical wicking which allows rapid uptake of liquid into the fibers. The absorbed exudate fluid can be distributed to the entire dressing rather than just over the wound surface, which results in larger fluid absorption capacity. From April, 2003 to July, 2004 a study was done with 40 patients who had variable partial thickness burns. $Aquacel^{(R)}$ dressing was compared in 21 cases to silver sulfadiazine cream 1% and saline wet gauze dressings in 19 cases. In the $Aquacel^{(R)}$ cases, the average healing time on the face was $5.36{\pm}1.69$ a day; on the hands was $8.46{\pm}2.15$ a day; and, on the neck was $6.0{\pm}2.0$ a day. With the $Silvadene^{(R)}$ and Saline wet gauze dressing, the average healing time on the face was $6.44{\pm}1.74$ a day; on the hands was $13.79{\pm}5.35$ a day; and, on the neck was $11.17{\pm}3.31$ a day. As a result, the $Aquacel^{(R)}$ group showed a shorter healing time compared to the $Silvadene^{(R)}$ and saline wet gauze dressing group and patients were satisfied because of less pain and improved comfort. In conclusion, $Aquacel^{(R)}$ is a better choice for partial thickness burn injuries because of shorter healing time, less pain and more confortable dressing.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1180-1190
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• 2020

Objective: To develop healthier comminuted meat products to meet consumer demand, the gel properties, rheological properties, microstructure and water distribution of pork meat batters formulated with various amounts of bamboo shoot dietary fiber (BSDF) were investigated. Methods: Different levels of BSDF (0% to 4%) were added to pork batters, and the pH, color, water-holding capacity, texture and rheological properties of pork batters were determined. Then, pork batters were analyzed for their microstructure and water distribution using scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR). Results: Compared with the control, BSDF addition into meat batters showed a significant reduction in L^*-value and a significant increase in b^*-value (p<0.05). BSDF addition of up to 4% reduced the pH value of pork batters by approximately 0.15 units; however, the cooking loss and expressible water loss decreased significantly (p<0.05) with the increased addition of BSDF. The hardness and gel strength were noticeably enhanced (p<0.05) as the content of BSDF increased. The rheological results showed that BSDF added into pork batters produced higher storage modulus (G') and loss modulus (G") values. The SEM images suggested that the addition of BSDF could promote pork batters to form a more uniform and compact microstructure. The proportion of immobilized water increased significantly (p<0.05), while the population of free water was decreased (p<0.05), indicating that BSDF improved the water-holding capability of pork batters by decreasing the fraction of free water. Conclusion: BSDF could improve the gel properties, rheological properties and water distribution of pork meat batters and decrease the proportion of free water, suggesting that BSDF has great potential as an effective binder in comminuted meat products.

• Journal of the Korean Vacuum Society
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• v.20 no.4
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• pp.288-293
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• 2011

We investigated the effects of piezoelectric field on the electro-absorption characteristics in InGaN/GaN multiple-quantum well (MQW) green light emitting diodes (LED). Double crystal X-ray diffraction measurement was performed to study the crystalline property and indium (In) composition in the MQW active layer. To measure the electro-luminescence and electro-reflectance (ER) spectroscopy, we fabricated the $1{\times}1\;mm^2$ large-area green LED chip. The piezoelectric field inside the LED structure was evaluated from the Vcomp in active layer by the ER spectra. Finally, we analyzed the electro-absorption characteristics of the green LED by using the photo-current spectroscopy.

• Journal of the Korean Magnetics Society
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• v.15 no.4
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• pp.246-249
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• 2005

The blue-color emitting phosphor powder, $CaMgSi_{2}O_6:Eu^{2+}(CMS:Eu^{2+})$ was synthesized by the solid-state reaction method. The synthesized powder was annealed from room temperature to $1,100^{\circ}C$ in air. Its PL property and valence state of Eu atoms was measured by the photoluminescence (PL) and the electron paramagnetic resonance (EPR) spectrometers, respectively. The PL intensity was stable to $700^{\circ}C$, but drastically decreased to $1,100^{\circ}C$. The behavior of EPR intensity was very similar to the PL intensity. The EPR measurement showed that decreased intensity of the PL was caused to the oxidation from the ion $Eu^{2+}$ to $Eu^{3+}$ ions. The EPR spectrometer was powerful as a tool that could distinguish between the valence states of Eu atom as a dopant in various phosphors.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.34-51
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• 2020

In order to clarify the lime-based building method used in the Joseon Dynasty, lime materials, production techniques, and mixing methods recorded in ancient literature were examined. In ancient Joseon Dynasty literature, the use of low grade limestone as a raw material was recorded, and the use of pozzolanic materials such as Hwangtoh, white clay, and roof tile powder as mixing aids to enhance the strength of lime was recorded. In addition, various lime hydration and mixing methods were recorded, and based on re-experiments carried out with regards to this, a physical property evaluation was deemed to be required in accordance with the various types of raw lime materials, lime hydration methods, and mixture ratios. In the early Joseon Dynasty, lime was used for various aspects, but frequent problems were experienced due to lack of supply and poor production techniques. In the late Joseon Dynasty, lime production techniques developed along with mass production. Based on analysis of the manufacturing techniques of Hoegwagmyo lime mortar in the 16^th and 18^th centuries during the Joseon Dynasty, it was found that mixing ratios and the methods described in the ancient literature had been applied. It was confirmed that the mixing ratio differed depending on mixing materials and lime quality. Since the mixing ratio of Hoegwagmyo lime mortar changed over time and it was produced strictly on the basis of a guidebook, it is believed that if continuous scientific analysis of the Hoegwagmyo lime mortar production method were carried out, this would be helpful for ascertaining the chronological methodology of Hoegwagmyo.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.407-415
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• 2019

The biological half-life of pesticides applied on crops is the key indicator for ensuring the safety of agricultural products. The biological half-life is affected by the several factors like growing conditions of the crop, climate, application method, and physicochemical properties of pesticides. In this study, the biological half-life was calculated and the degradation rates of six triazole fungicides sprayed on perilla leaves were evaluated. Moreover, the statistical analysis confirmed the correlation between the biological half-life and physicochemical properties of six triazole pesticides. The recoveries of the six pesticides were between 84.8-104.9%, which satisfied the residual pesticide analysis criteria. The biological half-life of six pesticides sprayed on perilla leaves, calculated using the first-order kinetics model, ranged between 6.4-15.1 days. When the biological half-life and the physicochemical properties were correlated using the principal component analysis: pKa and Log P, the biological half-life was found to be affected by PC1. The correlation coefficient between biological half-life and physicochemical properties (pKa), calculated by Spearman rank-order correlation, was R² = -0.928 (p <0.01). Biological half-life has been shown to correlate with pKa. In conclusion, it can be used as a database for the relationship between biological half-life and physicochemical properties and will contribute to ensure safe supply of agricultural products.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.297-306
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• 2020

The red mud generated from bauxite during the Bayer alumina production process has been regarded as an industrial waste due to the high alkaline property and high content of Na. Despite of its environmental problem, various studies for recovery of the valuable resources from red mud has been also carried out because of high content (25.7 wt.% as Fe₂O₃ in this study) of iron in red mud. In order to recover the iron resource in the red mud, microwave heating experiments were performed with adding of activated carbon and elemental sulfur to the red mud. Through the microwave heating the powdered red mud mixtures converted to porous and vitrified solid aggregates. The vitrified aggregates produced by microwave heating are composed of goethite, zero valent iron (Fe⁰), pyrrhotite and pyrite. And then, the microwave heating samples were dissolved in the aqua regia solution, and Fe precipitates were obtained as a Fe-chlorides by adding of NaCl salt in the aqua regia solution. The Fe recovery rates in the Fe-chloride precipitates showed differences depending on the experimental mixture conditions, and Fe grades of the end products are 49.0 wt.%, 58.0 wt.% and 59.5 wt.% under mixture conditions of red mud, red mud + activated carbon, and red mud + activated carbon + elemental S, respectively. The Fe content of 56.0 wt.% is generally known as the grade value of Fe in a iron ore for iron production, and the Fe grades of microwave heating samples with adding activated carbon and elemental S in this study are higher than the grade value of 56.0 wt.%.

• Journal of Life Science
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• v.25 no.6
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• pp.631-637
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• 2015

Streptavidin, a protein produced by Streptomyces avidinii, strongly binds up to four molecules of vitamin H, d-biotin exhibiting the dissociation constant of about 10⁻¹⁵ M. This strong binding affinity has been applied for detection and characterization of numerous biological molecules suggesting expression and purification of functional streptavidin should be very useful for the application of this streptavidin-biotin interaction. To express a soluble streptavidin in Escherichia coli, We synthesized streptavidin genes and cloned into pET-22b plasmid, which uses T7 RNA polymerase/T7 promoter expression systems containing pelB leader for secretion into periplasmic space and six polyhistidine tags at C-terminus for purification of expressed proteins. Although streptavidin is toxic to Escherichia coli due to strong biotin binding property, streptavidin was expressed very sufficiently in a range of 10-20 mg/ml. In SDS-PAGE, the size of purified protein was shown as 17 kDa in denatured condition (boiling) and 68 kDa in native condition (without boiling) suggesting tetramerization of monomeric subunit by non-covalent association. Further analysis by size-exclusion chromatography supported streptavidin’s tetrameric structure as well. In addition, soluble streptavidin detected biotinylated proteins in westernblot indicating its functional activity to biotin. Taken these results together, it concluded that our simple expression system was able to show high yield, homotetrameric formation and biotin binding activity analogous to natural streptavidin.