• Journal of the Korean Wood Science and Technology
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• v.1 no.2
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• pp.3-10
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• 1973

This study was carried out to examine the characeristics of waste sanders(S)from. plywood and pre-finishing plywood surface sanding and double saw finishing, as a new extander in urea-formaldehyde resin(UFR) in plywood adhesive, and to focus, adhesive strength using the glue extended with milled sanders(MS) as extender, leveling the optimum amount of MS to be added, and examining the physical properties of glue extended MS & S. Also economical good feasibility of substitution for wheat flour(WF) with MS as a new extender is analyzed and presented in details. Selecting three standard samples of 80, 100 and 180 mesh, sorking them in distilled water at $20^{\circ}C$, 24 hours, redrying at $105^{\circ}C$ and rescreening the sample with standard screen, again, the 3 samples of 80, 100, and 180 mesh are passed 23 percent through 80 mesh sander standard sample 27 percent through on 100 mesh and only 10.9 percent through 180 mesh, respectively. The particle size of retained parts are greater in size of redried form. It seems undoubtly that particles to be extended in glue are got swollen and become greater in size and coarser in shape. The shape of fresh S particles are irregular thin needle with small scale, as shown in Figure 5. PFS are so finer than plywood S that only 9.8 percent of the S retained on 100 mest screen, 24. 30 percent on 100-160 mesh, and 65.9% on 160-180 mesh. But particle size of the fresh S is large enough to make the viscosity of glue direct extended with S too high to apply it glue spreader. The glue extended with milled sanders(MS). 3 hours milled PFS or 6 hours milled plywood S, having particle sizes shown in Tables 7 and 8, as ratio of Reain/MS/WF/water: 100/8/8/10, indicate good viscosity of 16 to 24 ps, as shown in Figure 5, for applying direct to glue spreader, have high tensile-shear strength (adhesive strength), 102.4 kp/$cm^2$, and 94 percent wood failure.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.485-485
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• 2012

유기발광소자는 고휘도, 넓은 시야각, 빠른 응답속도, 높은 색재현성, 좋은 유연성의 소자특성 때문에 디스플레이 제품에 많이 응용되고 연구가 활발하게 진행되고 있다. 최근에 저소비전력, 고휘도, 소형화 및 장수명의 장점을 가진 유기발광소자의 상용화가 진행되면서 차세대 디스플레이소자로서 관심을 끌게 되었다. 고분자 유기발광소자는 저분자 유기발광소자에 비해 용액 공정법으로 박막을 형성할 수 있어 제조 비용이 적게 들며 대면적 디스플레이를 제작하는데 유리하기 때문에 많은 연구가 진행되고 있다. 고분자 유기발광소자에서 저전력 소자를 위한 저전압 구동 및 전력 효율을 향상시키기 위한 연구는 대단히 중요하다. 본 연구에서는 고분자 유기발광소자의 구동 전압을 낮추기 위해서 그래핀 정공 주입층을 삽입한 고분자 유기발광소자를 화학적 진공 증착법과 용액 공정을 사용하여 제작하였다. 그래핀 정공 주입층을 삽입한 고분자 유기발광소자는 Indium-tin-oxide(ITO) 투명 전극/그래핀 정공주입층/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT: PSS)/poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylenevinylene] (MEH-PPV) 층/lithium quinolate (Liq)/aluminium (Al) 전극의 구조를 가진다. 그래핀 정공주입층을 삽입한 고분자 유기발광소자에서 향상된 정공 주입능력을 통해 구동전압을 낮아지는 현상을 분석하기 위해서 전기적 및 광학적 특성을 조사하였다. 그래핀 정공주입층의 광학적 특성을 분석하기 위해서 빛의 투과도 측정을 한 결과 90% 이상의 값을 얻었다. 그래핀 정공 주입층이 소자에 미치는 영향을 조사하기 위하여 ITO/PEDOT:PSS소자와 ITO/그래핀 층/PEDOT:PSS 소자를 각각 제작하여 원자힘 현미경 측정을 하였다. 그래핀박막층을 삽입할 경우, 그래핀박막층을 삽입하지 않았을 때보다 표면 거칠기가 감소하는 것을 알 수 있었다. 이는 산성을 띠는 PEDOT:PSS 용액이 ITO 투명 전극을 손상시키는 것을 방지하고, 표면 거칠기를 감소시켜 누설 전류를 낮출 수 있다는 사실을 보여준다. 또한, 그래핀 박막은 높은 전기 전도도를 가지기 때문에 그래핀 정공주입층을 삽입하였을 때, 높은 전류 밀도 및 발광 휘도와 더 낮은 구동 전압을 확인할 수 있었다. 이러한 결과는 ITO와 PEDOT:PSS의 계면에서의 전공의 주입 능력을 그래핀박막층이 향상시켜 저전압, 고효율 소자를 제작할 수 있다는 것을 보여준다.

• Laser Solutions
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• v.11 no.4
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• pp.29-34
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• 2008

Ultraviolet laser micromachining has increasingly been applied to the electronics industry where precision machining of high-density, multi-layer, and multi material components is in a strong demand. Due to the ever-decreasing size of electronic products such as cellular phones, MP3 players, digital cameras, etc., flexible printed circuit board (FPCB), multi-layered with polymers and metals, tends to be thicker. In present, multi-layered FPCBs are being mechanically cut with a punching die. The mechanical cutting of FPCBs causes such defects as burr on layer edges, cracks in terminals, delamination and chipping of layers. In this study, the laser cutting mechanism of FPCB was examined to solve problems related to surface debris and short-circuiting that can be caused by the photo-thermal effect. The laser cutting of PI and FCCL, which are base materials of FPCB, was carried out using a pico-second laser(355nm, 532nm) and nano-second UV laser with adjusting variables such as the average/peak power, scanning speed, cycles, gas and materials. Points which special attention should be paid are that a fast scanning speed, low repetition rate and high peak power are required for precision machining.

• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.521-530
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• 2004

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which electrical power is not available. The average solar radiation power is $3.488\;kWh/(m^2{\cdot}day)$ in Korea. In this study, the experimental system of the water pump driven by the radiation energy were designed, assembled, tested and analyzed fur realizing the solar powered water pump. Energy conversion ken radiation energy to mechanical energy by using n-pentane as operating material was done and the water pumping cycles were able to be continued. The quantity of the water pumped per cycle ranged from 2 L to 10 L depending on the level of the valve open area far the vapour supply. The average quantity was about 4,366 cc. The thermal efficiency was about $0.018\%$. The pressure level of the n-pentane vapour in flash tank was about $110\~150\;kPa$ and that in the water tank was $93\~130\;kPa$. The pressure in the condenser during cycles was maintained as about 70 kPa. The condensation of the n-pentane vapour in the water tank was increased with the cycles even though the internal and external insulation were done. Air tank performance was better with increasing of the water piston displacement and the water could be pumped with the water piston displacement becoming higher than 6,500 cc.

• Journal of Korea Foresty Energy
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• v.7 no.1
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• pp.28-36
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• 1987

To know the possibility of fuel substitution for Diesel engine with the seed oil of Evodia daniellii, which is one of the native oil seed trees in Korea. the refined seed oil mixed with light oil in the various rates was tested in the 8 PS Diesel engine: the output, the fuel consumption rate, the governor performance, the rpm stability in the total loading condition. the content of graphite in the burned gas, and the traction coefficients at the different gear stages were maintained The following results were discussed. 1. The output at the normal revolution (2200rpm)was increased as the percent seed oil increased. At the lower rpm (2000-1500rpm )there were no consistent difference in the outputs among fuels of the different percent seed oil 2. The rate of fuel consumption was inclosed as the percent seed oil increased in each loading condition. 3. The more percent sud oil was mixed in the fuel. the better governor performance appeared at both the instantaneous and stable speed. 4. The more percent seed oil was mixed In the fuel, the more stable rpm ratio was maintained 5. The graphite content In the burned gas was increased as the load increased, but there was no apparent difference in the content at each load among the 100$\%$ seed oil, the 100$\%$ light oil, and the mixtures in various rates. 6. In all fuel mixtures the maximam traction coefficent appeared at the third transmission gear stage. Generally in over all transmission gear stages the fuel mixtures of the seed oil:light oil ratio from 7:3 to 5:5 resulted greater traction force than the other fuels.

• Journal of Plant Biology
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• v.36 no.2
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• pp.133-140
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• 1993

The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO2 uptake rates and room temperature chlorophyll fluorescence were investigated in cotyledons of cucumber seedlings exposed to low temperature (at 4$^{\circ}C$) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO2 uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS II and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light- and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid pH formation, and that photosynthetic apparatus of cucumber cotyledons is more susceptible to light-chilling. In the fast fluorescence induction kinetics, FR was decreased by 60% in the light-chilled plants with reference to $25^{\circ}C$ light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to $25^{\circ}C$ dark-treated plants for 24 h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

• Food Science and Preservation
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• v.14 no.4
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• pp.351-355
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• 2007

Solvent-extracted volatile components from dry powder prepared from Citrus unshiu products such as immature Citrus unshiu (PCU), mature Citrus unshiu (MCU), Citrus unshiu peel (CUP), and citrus juice processing wastes (CJPW), were examined. Also, solvent-extracted volatile components from mushroom mycelia of Pycnoporus coccineus (PC), Lentinus edodes (LE), Pleurotus eryngii (PE), Hericium coralloides (HC), Panellus serotinus (PS), and Ganoderma lucidum(GL), all cultivated using citrus pulp solid media, were assayed. Twenty-nine volatile components were identified in dry powder prepared Citrus unshiu and 18 volatile components were characterized from mushroom mycelia. Of these, ${\beta}-elemene$, germacrene-D, and ${\delta}-cadinene$, were derived from CJPW, but caryophyllene, hexadecanoic acid, decanoic acid, and tetradecanoic acid were synthesized by mushroom mycelia.

• 전자공학회논문지 IE
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• v.45 no.4
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• pp.33-41
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• 2008

Telematics system includes the "vehicle remote diagnosis technology", "driving pattern analysis technology" which are commercially attractive in the real life. To implement those technologies, we need vehicle signal interface, vehicle diagnosis interface, accelerometer/yaw-rate sensor interface, GPS data processing, driving pattern analysis, and CDMA data processing technique. Based on these technologies, we analyze the error existence by diagnosing the EMS(Engine Management System), TMS(Transmission Management System), ABS/TCS, A/BAG in real time. And we are checking about a driving pattern and management of the vehicle, which are sent to the information center through the wireless communication. These database results will make the efficient vehicle and driver management possible. We show the effectiveness of our results by field driving test after completing the H/W & S/W design and implementation for vehicle remote diagnosis and driving pattern analysis.

• KSBB Journal
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• v.13 no.4
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• pp.418-423
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• 1998

Cellular transfections with cationic liposomes are widely empolyed for gene and oligonucleotide transfer in vitro because of their safety and ease of use. However, they still suffer from the low transfection efficiency comparing with viral vectors. Substantial effort shave been focused on increasing transfection efficiency by supplementing the liposome/DNA complexes(lipoplex) with various components. In this work, we tired three kinds of supplements, Poly-L-lysine(PLL), transferrin and a mixture of anionic lipids(PS/PE/PC), to study their effects on gene transfer yield and gene expression efficiency. PLL, a polycationic polymer, enhanced gene transfer yield by 3 times but the gene expression efficiency was increased only by 1.5 times. this result implies that PLL can enhance the transfection efficiency mainly by increasing the rate of outermembrane transport of lipoplex into the cells. On the other hand, transferrin which can facilitate the gene transfer via ligand-receptor interaction gave not only increased gene transfer yield but also enhanced gen expression efficiency by 2.8 times. Transferrin seems to contribute to the escape of plasmid from endosomes through ligand-receptor recycle mechanism. When the cells were treated with a mixture of anionic lipids for 3 hours before the transfection, gene transfer yield was slightly decreased but the gene expression efficiency was enhanced by 1.9 times. This is presumably due to the accelerated liposome-plasmid dissociation by the anionic lipids, and the increased delivery of plasmid to the nucleus. According to these results, it is clear that the supplementation to ameliorate transfection efficiency with cationic liposomes should be contrived in the direction of increasing delivery of plasmid.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.544-551
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• 2003

Interactive effects of UV-B and Cd on growth, pigment, photosynthesis, and lipid peroxidation have been studied in Anabaena, Microcystis, and Nostoc; all the tested cyanobacteria showed differential sensitivity to different dosage of UV-B and Cd alone as well as in combination. Phycocyanin was severely affected by UV-B and Cd by all the strains; the degree of pigment bleaching was most pronounced in Anabaena followed by Microcystis and Nostoc. $UV-B_2+Cd_2$ produced nearly 83, 78, and 65% inhibition of phycocyanin in Anabaena, Microcystis, and Nostoc, respectively. The above treatment also significantly decreased the contents of Chl ${\alpha}$ and carotenoid. Presence of capsule in Microcystis protected the phycocyanin bleaching as compared to decapsulated cells. Laboratory-grown Microcystis revealed about 75 and 80% inhibition, following $UV-B_2+Cd_2$ treatment, respectively. in capsulated and decapsulated cells. Damage caused by Cd was more pronounced than UV-B. Inhibition of photosynthesis did occur in all the test strains, being maximum in Anabaena. PS II was the most sensitive component of the electron transport chain, showing 84, 80, and 70% inhibition in Anabaena, Microcystis, and Nostoc, respectively. As compared to control, significant lipid peroxidation (6.5-fold higher) was observed in Anabaena with $UV-B_2+Cd_2$, $^{14}C-uptake$ was more susceptible to Cd and Uv-B than oxygen-evolution. Approximately 84, 80, and 76% inhibition of $^{14}C-uptake$ was observed in Anabaena, Microcystis, and Nostoc, respectively. Similarly, $UV-B_2+Cd_2$ inhibited APT content of Anabaena by 87%. This ,study suggests that inhibition of carbon fixation was due to decreased ATP content of the test cyanobacteria by UV-B+Cd, where Anabaena was the most sensitive and Nostoc the most tolerant.