• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.192-209
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• 1995

The purpose of this study was to evaluate drug-loaded biodegradable membranes for guided tissue regeneration(GTR). The membranes were made by coating mesh of polyglycolic acid(PGA) with polylactic acid(PLA) containing 10% flurbiprofen or tetracycline. The thickness of membrane was $150{\pm}30{\mu}m$, and the pore size of surface was about $8{\mu}m$ in diameter. The release of drugs from the membrane was measured in vitro. Cytotoxity test for the membrane was performed by gingival fibroblast cell culture, and the tissue response was observed after implant of membrane into the dorsal skin of the rat for 8 wks. Ability to guided tissue regeneration of membranes were tested by measuring new bone in the calvarial defects(5mm in diameter) of the rat for 5 weeks. The amount of flurbiprofen and tetracycline released from membrane were about 30-60% during 7 days. Minimal cytotoxity was observed in the membrane except 20% drug containing membrane. In histologic finding of rat dorsal skin, many inflammatory cells were observed around e-PTFE, polyglactin 910 and PLAPGA membrane after 1 or 2 weeks. PLA-PGA membrane was perforated by connective tissue after 4 or 6 weeks, and divided as a segment at 8 weeks. In bone regeneration guiding potential test, tetracycline loaded membrane was most effective (p

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.82-93
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• 2008

The flowfield behind two cylinders and flow-induced noise generated from the cylinders in various arrangement are numerically investigated based on the finite difference lattice Boltzmann model with 21 velocity bits. which is introduced a flexible specific heat ${\gamma}$ to simulate diatomic gases like air. In an isolated cylinder with two type of mesh. some flow parameters such as Strouhal number $S_t$ and acoustic pressure ${\Delta}p$ simulated from the solution are given and quantitatively compared with those provided the previous works. The effects of the center-to-center pitch ratio $L_{cc}/d=2.0$ in staggered circular cylinders as shown in Fig. 1 and angles of incidence ${\alpha}=30^{\circ}(T_{cc}/d=0.5)$, $45^{\circ}(T_{cc}/d =0.707)$ and $60^{\circ}\;(T_{cc}/d=0.866)$, respectively, are studied. Our analysis focuses on the small-scale instabilities of vortex shedding, which occurs in staggered arrangement. With the results of drag $C_d$ and lift $C_l$ coefficients and vorticity contours. the mechanisms of the interference phenomenon and its interaction with the two-dimensional vortical structures are present in the flowfields under $Re\;{\le}\;200$. The results show that we successively capture very small pressure fluctuations, with the same frequency of vortex shedding, much smaller than the whole pressure fluctuation around pairs of circular cylinders. The upstream cylinder behaves like an isolated single cylinder, while the downstream one experiences wake-induced flutter. It is expected that, therefore, the relative position of the downstream cylinder has significant effects on the flow-induce noise, hydrodynamic force and vortex shedding characteristics of the cylinders.

• 복식문화연구
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• 제26권4호
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• pp.613-631
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• 2018

The purpose of this study is to collect and analyze costumes presented in international dance sports competitions, and summarize the features of Latin American dance costumes' design. As for research methods, standards of Latin American dance costume design were analyzed via a literature review on dance sports. The scope of the study extended for six years from 2010 to 2015 to include the, top three UK Latin American dance competitions. The results are as follows. First, the silhouette analysis determined that the X silhouette to the lead with, -145 costumes (78%), followed by the H silhouette at 25 (13%), and other at 16 (9%). Amongst those there were 174 one-piece dresses (94%). Furthermore, the analysis on colors of Latin American dance sports costumes revealed that, amongst the 186 costumes, 115 were without color (62%), Bl(black) is the most frequent with 37%, then Wh(white) with 21% and Gr(gray) with 4%. Costumes with colors, based on the six basic colors in the Munsell color system, are comprised most often of red with 12%, the followed by Y(yellow) at 10%, B(blue) at 8%, YR(yellow-red) at 4%, P(purple) at 2%, and G(green) at 2%. Thirdly, the cloth materials of Latin American dance costumes are recognized through image inspection. Among visually recognizable materials, beading materials are the most common with 104 costumes (60%). Shiny materials like mesh, chiffon, organza, lace and burn-out are in 36 costumes in total (19%). Other cloth materials included Luster materials and; non-sheen materials, which were in 46 costumes (25%).

• 센서학회지
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• 제29권4호
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• pp.255-260
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• 2020

In this study, we developed a method of improving the surface-enhanced Raman spectroscopy (SERS) response characteristics by depositing a nanoporous Ag metal thin film through cluster source sputtering after forming a pyramidal texture structure on the Si substrate surface. A reactive ion etching (RIE) system with a metal mesh inside the system was used to form a pyramidal texture structure on the Si surface without following a complicated photolithography process, unlike in case of the conventional RIE system. The size of the texture structure increased with the RIE process time. However, after a process time of 60 min, the size of the structure did not increase but tended to saturate. When the RF power increased from 200 to 250 W, the size of the pyramidal texture structure increased from 0.45 to 0.8 ㎛. The SERS response characteristics were measured by depositing approximately 1.5 ㎛ of nanoporous Ag metal thin film through cluster sputtering on the formed texture structure by varying the RIE process conditions. The Raman signal strength of the nanoporous Ag metal thin film deposited on the Si substrate with the texture structure was higher than that deposited on the general silicon substrate by up to 19%. The Raman response characteristics were influenced by the pyramid size and the number of pyramids per unit area but appeared to be influenced more by the number of pyramids per unit area. Therefore, further studies are required in this regard.

• 한국식품영양과학회지
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• 제17권4호
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• pp.283-289
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• 1988

변온조건하에서 보리가루를 저장하였을 때 수분활성에 따른 avaible lysine의 손실을 반응속도론적으로 고찰한 결과 Avalilable lysine은 일차반응으로 감소하였으며 반응속도는 수분활성과 저장온도가 높을수록 빨랐고, 각 수분활성에서의 활성화 에너지는 $6.02{\sim}10.32Kcal/mole$, $Q_10$치는 $1.34{\sim}1.65$였다. Acelerated shelf-life test로부터 구한 $25^{\circ}C$에서의 shelf-life는 $60{\sim}216$일의 범위였으며 온도와 수분활성이 증가함에 따라 단축되었다. 변온조건에서의 실측치와 예측치를 비교한 결과 유효온도차는 $1.21{\sim}2.23^{\circ}C$였고 shelf-life는 실측치와 예측치가 약간 차이를 나타내었다.

• 펄프종이기술
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• 제45권4호
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• pp.34-41
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• 2013

In this study, we investigated the physical properties of powders made from agricultural byproducts, including rice straw, peanut husks, and garlic stems, to manufacture a new organic filler used for making paperboard. These materials were collected individually, and then we measured their chemical compositions. The byproducts were ground with a laboratory grinder and fractionated with 60-, 100-, and 200-mesh sieves to make many grades of organic fillers. After the grinding and fractionation, the yield, mean particle size, and particle size distribution of each grade were measured. Particle shapes were also investigated using a scanning electron microscope. The organic filler made from rice straw had the highest yield of the largest particle size group and higher contents of cellulose and hemicellulose than those made from peanut husks and garlic stems. The rice straw also showed more regular particle shapes and a lower aspect ratio than the other agricultural byproducts.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.505-505
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• 2009

The object is to optimize the best condition of organosolv pretreatment process with sulfuric acid as a catalyst. As a material, Pitch pine (Pinus rigida) was ground and sieved through 40-mesh screen, and Celluclast and $\beta$-glucosidase were used as enzymes for enzymatic hydrolysis. Pretreatment processes were carried out in the minibomb, and 20 g of materials with 200 ml of 50% ethanol solution (v/v) with 1% sulfuric acid as a catalyst. Pretreatment temperature was varied from $150^{\circ}C$ to $190^{\circ}C$, and time was varied from 0 to 20 min. Then, residual materials were used for enzymatic hydrolysis. The best conditions were selected by estimating followed enzymatic hydrolysis rate and degradable rates after pretreatment process. The highest value of enzymatic hydrolysis rate was obtained as 55 - 60% at 160 and at $180^{\circ}C$, but the value decreased under more severe conditions. As the residual rates decreased under severe conditions, it infered that the decrease of sugar contents limits enzymatic hydrolysis rates. Combined with enzymatic hydrolysis rate, degradable rates and H-factors, the temperatures at $160^{\circ}C$ for 20 min and at $180^{\circ}C$ for 0 min were concluded as the optimized conditions where have the lowest H-factor value for considering energy input.

• Journal of Biosystems Engineering
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• 제27권6호
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• pp.529-536
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• 2002

The performance of stilting engine, in particular, its energy conversion efficiencies are critically influenced by the regenerator characteristics. The regenerator characteristics are influenced by effectiveness, void fraction. heat transfer loss and fluid friction loss in the regenerator matrix. These factors were influenced by the surface geometry and material properties of the regenerator matrix. The regenerator design goals arc good heat transfer and low pressure drop of working Bas across the regenerator. Various data for designing a wire screen matrix have been given by Kays and London(1984). The mesh number of their experiment. however, was confined below the No. 60. which seems rather small for the Stirling engine applications. In this paper. in order to provide a basic data for the design of regenerator matrix, characteristics of heat transfer and flow friction loss were investigated by a packed mettled of matrix in oscillating flow as the same condition of operation in a Stirling engine. Seven kinds of sing1e wire screen meshes were used as the regenerator matrices. The results are summarized as follows; 1. While the working fluid flew slowly in the regenerator. the temperature difference was great at the both hot-blow(the working fluid flows from healer to cooler) and cold-blow(the working fluid flows from cooler to healer). On the other hand. while the working fluid flew fast. the temperature difference was not distinguished. 2. The No.150 wire screen used as the regenerator matrix showed excellent performance than tile others. 3. Phase angle variation and filling rate affected heat transfer or regenerator matrices. 4. Temperature difference between the inlet and outlet of the regenerator is very hish in degree of 120 phase angle.

• 한국식품조리과학회지
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• 제8권3호
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• pp.233-239
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• 1992

The characteristics of Packsulgi were investigated with different cooking methods of conventional and pressure cookers and variation in panicle size of rice flour. The water contents of rice f1ours and Packsulgis were greater as the particle became coarser. The water contents of Packsulgis cooked with pressure cooker (P) were greater than those of conventional cooker (C). Degree of gelatinization in P was higher than that of C. There were no significant differences among the samples of P, whereas coarser f1ours tended to show higher degree of gelatinization than finer ones in C. The results of textural properties measured by rheometer showed that hardness, cohesiveness and gumminess of P was higher than that of C. The textural parameter of P increased as the particle became finer, whereas mat of C increased as the particle became coarser. L value of C was higher than that of P in me same particle size, whereas a and b value of P was higher than that of C. L and a value of both P and C increased as the particle became finer. b value in P increased as the particle became coarser, whereas mat in C increased as the particle became finer. According to me sensory evaluation, the appearance of C was more acceptable man that of P, whereas the texture of P was more acceptable than mat of C. There were no significant differences in overall quality among P and c and Packsulgis made by 60, 100 mesh rice f1our had higher acceptability than others.

• 한국수소및신에너지학회논문집
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• 제13권2호
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• pp.110-118
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• 2002

The hydrogen storage vessel having a good heat conductivity along with a simple structure and a low cost for these alloys was designed and manufactured, and then its characteristic properties were studied in this study. The various parts in hydrogen storage vessel consisted of copper pipes and stainless steel of 250 mesh reached the setting temperature after 4~5 minutes, which indicated that storage vessel had a good heat conductivity that was required in application. And also the storage vessel had a good property of hydrogen transport considering that the reaction time between hydrogen and rare-earth metal alloys in storage vessel was found to be within 10 min at $18^{\circ}C$ under 10 atmospheric pressure. It showed that the average capacity of discharged hydrogen volume was found to be $120{\ell}$ for $MmNi_{4.5}Mn_{0.5}$ under discharging conditions of $40^{\circ}C{\sim}80^{\circ}C$ at a constant flow rate of $5{\ell}$/min. It was found that the optimum discharging temperature for obtaining an appropriate pressure of 3atm was determined to be $60^{\circ}C$ for $MmNi_{4.5}Mn_{0.5}$ hydrogen storage alloy.