• Current Photovoltaic Research
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• 제7권3호
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• pp.65-70
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• 2019

As a demand of higher power photovoltaic modules, shingled, multi-busbar, half-cell, and bifacial techniques are developed. Multi-busbar module has advantage for large amount of light havesting. And, half-cell is high power module for reducing resistive losses and higher shade tolerance. Recently, researches on multi-busbar is focused on reliability according to adhesion and intermetallic compound between Sn-Pb solder and Ag electrode. And half-cell module is researched to comparing with full-sized cell module for structure difference. In this study, we investigated the factors affecting to efficiency and adhesion of multi-wires half-cell module according to wire thickness, solder thickness, and flux. The results of solar simulator and peel test was that peel strength and efficiency of soldered cell is not related. But samples with flux including high solid material showed high efficiency. The results of FE-SEM and EDX line scan on cross-section between wire and Ag electrode for different flux showed thickness of solder joint between wire and Ag electrode is increasing through solid material increasing. Flux including high solid material would affect to solder behavior on Ag electrode. Higher solid material occurred lower growth of IMC layer because solder permeate to sider of wire ribbon than Ag electrode. And it increased fill factor for high efficiency. In soldering process, amount of solid material in flux and solder thickness are the factor related with characteristic of soldered photovoltaic cell.

• 한국염색가공학회지
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• 제33권3호
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• pp.153-160
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• 2021

In this study, composite materials were prepared by varying the content of glass fiber and bamboo fiber in PP/glass fiber/bamboo fiber. Experiments were conducted to confirm the mechanical properties(tensile, impact and burst strength) and volatile organic compound content of the bamboo fiber composite prepared under these conditions. An improvement in the main properties was observed at a fiber content of 30wt%. When the fiber fraction was increased above 30wt%, the mechanical properties tended to decrease due to the agglomeration of fibers at higher load fractions. In addition, the content of volatile organic compounds increased as the content of bamboo fibers increased, which is thought to be due to the volatile organic compounds generated during the manufacturing process of the composite material being present in the composite material without escaping from the pores of the bamboo fibers and volatilizing at a certain temperature. As a result of confirming the physical properties of the composite, it is considered that the optimal mixing condition is 30wt% of bamboo fiber for the composite produced by varying the amount of bamboo fiber composite. In the future, it is thought that follow-up experiments to confirm and improve the pre-treatment conditions for reducing the content of volatile organic compounds in the manufactured composite material are possible.

• 보존과학회지
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• 제37권6호
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• pp.738-747
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• 2021

제철원료별 직접제련법 복원실험으로 생산된 단조박편의 재료과학적 분석을 통해 금속학적 특성을 규명하였다. 제련을 위해 경주감포사철과 양양철광석을 이용하며, 각각 4개의 그룹을 설정하였다. 분석은 주성분, 광물 동정, 미세조직 관찰을 하였다. 주성분 분석 결과 정련·단접이 진행될수록 Fe의 함량은 증가하고 비금속개재물의 함량은 감소하였다. 광물을 동정한 결과 산화철 계열의 광물이 확인되었다. 미세조직 관찰 결과 Wüstite, Fayalite가 관찰되었으며, 일부에는 응집된 Wüstite가 관찰되었다. 일부 다각형, 장주상의 Magnetite도 확인되었다. 또한, 공극 및 불순물, 비금속개재물은 점차 감소하였다. 차후 다양한 제철원료를 이용한 복원실험을 통해 생산된 단조박편의 재료과학적 분석을 통해 금속학적 특성을 규명하고, 이를 유적에서 출토된 단조박편과 비교·검토하는 것이 필요하다.

• 대한약침학회지
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• 제19권3호
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• pp.246-252
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• 2016

Objectives: The purpose of this study was to obtain a natural antibiotic from Phenol-rich compounds; for the dressing and the treatment of chronic wounds. Methods: The Phenol-rich compound sweet gel was prepared by blending four natural herbal extracts, Acacia catechu (L.F.), Momia (Shilajit), Castanea sativa, and Ephedra sinica stapf, with combination of a sweet gel medium, including honey, maple saps, Phoenix dactylifera L. (date), pomegranate extract and Azadirachta indica gum as a stabilizer. The combinations were screened by using a well-diffusion assay with cloxacillin as a control. Pseudomonas spp. was tested with our novel antimicrobial compound. The zones of inhibition in agar culture were measured for each individual component and for the compound, and the results were compared with those of the control group which had been treated with cloxacillin. Data were expressed as means ${\pm}$ standard deviations. Quantitative analyses were performed using the paired t-test. Results: The antibiotic effect of the Phenol-rich compound sweet gel was statistically shown to be more significant than that of cloxacillin against Pseudomonas aeruginosa (P < 0.05). Conclusion: Our novel approach to fighting the antibiotic resistance of Pseudomonas proved to be successful. The Phenol-rich compound sweet gel was found to be suitable for use as an alternative medicine and bioactive dressing material, for the treatment of patients with various types of wounds, including burns, venous leg ulcers, ulcers of various etiologies, leg ulcers on the feet of diabetic, unhealed graft sampling sites, abscesses, boils, surgical wounds, necrotic process, post-operative and neonatal wound infection, and should be considered as an alternative to the usual methods of cure.

• 전기학회논문지
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• 제61권8호
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• pp.1153-1158
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• 2012

Niobium oxide ($Nb_2O_5$) has a strong chemical coherence and good electrical conductivity. Therefore, this material is helpful to enhance the performance of the dye sensitized solar cells (DSC) by improving the electron mobility. In this study, $Nb_2O_5$ was mixed with $TiO_2$ and this compound was applied to the DSC to improve its performance. As a result, the current density of the DSC using the $Nb_2O_5-TiO_2$ compound on the photoelectrode was increased, because the internal resistance concerned to the electron transfer in the photoelectrode of DSC was decreased. However, large amount of the $Nb_2O_5$ induces the decrease of the efficiency of the DSC because the surface area to attach dye molecules is decreased due to the large particle of $Nb_2O_5$. Therefore, it is important to optimize the mixture ratio of the $Nb_2O_5-TiO_2$ compound for maximizing the performance of the DSC. Finally, the most optimum performance of the DSC was shown in case of the $Nb_2O_5$ concentration of 10 wt% of the $Nb_2O_5-TiO_2$ compound.

• 전기의세계
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• 제16권3호
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• pp.21-27
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• 1967

We meet with the fact that a majority of electric machinery have been insulated to the state of solids & liquids or solids & gases, that is, with compound dielectrics. And also we can find voids caused by undesirbble structure, long-used material and so on. When it is discharged in a void or in the parts of gases of insulating material, the insulation of the machinery is gradually and finally destroyed through the effect of ozone, nitrogen-oxide, electronic pulses and so on. So we maybe conculded that it is necessary and important to detected void pulse and void corona in order to prevent sudden break down of electric machinery.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1260_1261
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• 2009

A detailed investigation and structure of tested samples are clearly presented. As a reference, $Ge_1Se_1Te_2$/Sb only sample was also investigated. We used compound of Ge-Se-Te material for phase-change cell. Actually, the performance properties have been improved surprisingly then conventional Ge-Sb-Te. However, crystallization time was as long as ever for amorphization time. We conducted this esperiment in order to solve that problem by doping-Sb.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.415-416
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• 2009

Concrete with Self-healing Admixture provides waterproof protection by using a organic-inorganic chemical compound throughout the concrete. Using cement chemicals eliminate the need to use additional waterproofing, If crack is occurred, this system enhance self-healing ability to increase the structural safety. In this study, we investigate material properties to conclude mixture rate of concrete to apply a construction site.

• 통합자연과학논문집
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• 제3권2호
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• pp.107-111
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• 2010

Silicon-containing ${\pi}$-conjugated compounds, especially silacyclopentadienes (siloles), have emerged as a new class of electroactive materials with good electron transport properties in OLEDs. 9,9'-spiro-9-silabifluorene compound as well as its starting material 2,2'-dibromobiphenyl have been synthesized with higher yields. Spirosilabifluorene is expected to be an efficient host material for the blue-light emitting diodes. 9,9'-spiro-9-silabifluorene, 1,1-dichloro-1-silafluorene, and 1,1-dimethyl-1-silafluorene were characterized by $^1H$-NMR, UV/Vis and photoluminescence spectroscopy.

• KIEAE Journal
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• 제4권4호
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• pp.3-10
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• 2004

If move in in the new apartment usually, do that hundreds hazardous substance among air floats and is broken-down. In the case of the floor, organic compound turns in adhesives that is bitter when attach the reinforcement floor and material lumber and hazardous substance is exhausted much wallpaper and concrete. Therefore, to reveal maximum this research to apply on interior of building to live function of charcoal, at non combustible material two faces that can promise safety from fire, strong and satisfy light performance, and it is thing about development of sheathing that use recycling material for barren land of multi-function and surface treatment of charcoal board as well as can keep healthy indoor environment.