• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.303-304
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• 2008

Al, N-codoped ZnO(ZnO:N,Al) thin films were deposited on n-type Si(100) substrate at $450^{\circ}C$ with various conditions of ambient gas$(N_2:O_2)$ by DC magnetron sputtering method using ZnO:$Al_2O_3$(2wt%) as a target, and then were annealed at 500, 700, $800^{\circ}C$ in $N_2$ gas for one hour. XRD patterns showed that all of the ZnO:N,Al thin films annealed at $80^{\circ}C$ grew with two peaks, which means poor crystallinity of the thin films deposited. Hall effects in Van der Pauw configuration proved that after annealing the films deposited showed low resistivity and high carrier concentration. While the films annealed at $800^{\circ}C$ showed low resistivity of $\sim10^{-2}\Omega$ cm and high carrier concentration of $\sim10^{19}cm^{-3}$.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.107-107
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• 2011

오늘 날 transparent conductive oxide는 다양한 분야에서 활용되고 있다. 최근에는 태양전지 분야에서도 많이 활용되고 있으며, 초기에는 transmittance 및 낮은 sheet resistance 특성을 가지는 ITO가 많이 활용되었지만 thin film solar cell와 같이 hydrogenation 공정에 약한 ITO보다는 Al-doped ZnO가 사용되기 시작하면서 많은 연구가 진행되고 있다. 본 연구에서는 thin film solar cell 및 silicon heterojunction solar cell에 적용 가능한 Al-doped ZnO에 관한 연구로써 a-Si:H의 Si-H bonds에 영향을 주지 않는 낮은 영역의 substrate temperature와 power로 Al-doped ZnO를 형성하고 상기 parameter에 따른 Al-doped ZnO의 특성 변화에 대해서 분석하였다. 특히 substrate temperature가 변화할수록 carrier concentration 및 sheet resistance가 많은 변화를 보였으며 이로 인하여 transmittance 특성이 온도에 따라 좋아지다가 너무 높은 온도에서는 오히려 좋지 않게 되었다. 이는 너무 높은 carrier concentration은 free carrier absorption에 의해 transmittance 특성을 오히려 좋지 않게 한다. 우리는 본 연구를 통해 92.677% (450 nm), 90.309% (545 nm), 94.333% (800 nm)의 transmittance를 얻을 수 있었다.

• Journal of Environmental Science International
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• v.32 no.10
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• pp.731-739
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• 2023

In this study, lab-scale phosphorus coagulation/precipitation experiments were performed using three types of polyaluminum chloride (PAC) with different Al contents (10%, 12%, and 17%). The PO₄-P removal efficiencies at various operating conditions, such as initial PO₄-P concentration, initial pH, and Al/P molar ratio, were evaluated, and correlations among the operating factors affecting phosphorus coagulation/precipitation with PAC were derived to optimize the process efficiency. When the initial PO₄-P concentration was 0.065 and 0.161 mmol P/L under an initial pH of 8-10, the optimal PAC dose was 0.126-0.378 and 0.189-0.667 mmol Al/L, respectively. Under these conditions, the Al/P molar ratio was 2.16-6.18 and 1.28-4.30, respectively, and the PO₄-P removal efficiency was in the range of 40.2-92.5%. When the Al/P molar ratio was 2 or less under an initial pH condition of 6-8, the PO₄-P removal efficiency was approximately ≤40% owing to insufficient Al³⁺ ions. However, when the Al/P molar ratio is 3-5, the PO₄-P removal efficiency improved to approximately 80-90%. Thus, the optimal Al/P molar ratio to achieve a PO₄-P removal efficiency of over 90% was determined to be approximately 4 in the PO₄-P coagulation/precipitation process using PAC.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.127-128
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.109-109
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• 2001

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.33-34
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• 2000

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.293-308
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• 2020

This study aims to investigate the direct relationship between ownership structure, earnings manipulation, and organizational performance, and then examine the mediating effect of earnings manipulation in the relationship between ownership structure and organizational performance. This study collected and analyzed secondary data published in financial reports related to all insurance organizations listed in the Jordanian market during the study period (from 2009 until 2018). A panel data analysis was conducted, giving a total of 200 observations. The findings of this study concluded that ownership concentration, foreign ownership, and organization size affect organizational performance proxied by ROA, ROE, and EPS, more specifically, ownership concentration and organization size have a positive effect, whereas foreign ownership has a negative effect. At the same time, board of director ownership, organizational ownership, and CEO compensation did not affect organizational performance. Next, the board of director ownership, ownership concentration, foreign ownership, and CEO compensation affect earnings manipulation separately. In addition, earnings manipulation positively affects organizational performance proxied by ROA, ROE and EPS. This means that the higher the earnings manipulation is, the higher the organizational performance is. Finally, earnings manipulation mediates the relationship between ownership concentration and foreign ownership of ownership structure, and organizational performance.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.381-388
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• 2003

The material deficiencies in the form of pre-existing defects can initiated cracks and fractures. The stress distribution and fatigue crack initiation life of engineering materials may be associated with the size, the shape and the relative location of defects contained in the component. The objective of this study is to investigate the effect of arbitrarily located hole defect around the rivet hole of a wing section in monolithic aluminum and Al/GFRP laminates under cyclic bending moment during a service load. The stress distribution and the fatigue crack initiation behavior near a rivet hole of on the relationships between stress concentration factor ($K_t$) and relative position of defects were considered. The test results indicated the features of different stress field. Therefore, the stress concentration factor ($K_t$) and the fatigue crack initiation behavior was illustrated different behavior according to each position of hole defect around the rivet hole in monolithic aluminum and Al/GFRP laminates.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1200-1205
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• 2014

The effect of nanofluids on the heat transfer performance of a pulsating heat pipe has been experimentally investigated. Water-based diamond nanofluid and aluminium oxide ($Al_2O_3$) nanofluid were tested in the concentration range of 0.5-5%. The pulsating heat pipe was constructed using clear Pyrex tubes of 1.85 mm in inner diameter in order to visualize the pulsating action. The total number of turns was eight each for heated and cooled parts. The supply temperatures of heating water and cooling water were fixed at $80^{\circ}C$ and $25^{\circ}C$ respectively. The liquid charging ratio of the nanofluid was 50-70%. The test results showed that the case of 5% concentration of diamond nanofluid showed 18% increase in heat transfer rate compared to pure water. The case of 0.5% concentration of $Al_2O_3$ nanofluid showed 24% increase in heat transfer rate compared to pure water. But the increase of $Al_2O_3$ nanofluid concentration up to 3% did not show further enhancement in heat transfer. It is also observed that the deposited nanoparticles on the tube wall played a major role in enhanced evaporation of working fluid and this could be the reason for the enhancement of heat transfer by a nanofluid, not the enhanced thermal conductivity of the nanofluid.

• Korean Journal of Veterinary Research
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• v.64 no.2
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• pp.12.1-12.6
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• 2024

The current study aimed to determine the effect of silver and chitosan nanoparticles of size 10 to 30 nm on the dead of lice in vitro and in vivo to determine the optimal time and concentration to combat chicken lice. One hundred local chickens Gallus gallus domesticus were collected from Al-Diwaniyah province and 6 species of local chicken lice were isolated: Menacanthus stramineus, Menacanthus pallidullus, Menacanthus cornutus, Goniodes gigas, Cuclotogaster heterographus and Bonomiella columbae. The results of treating lice with chitosan and silver nanoparticles at concentrations (40, 60, and 80 mg/mL) in vitro and at different periods (5, 10, 15, and 30 minutes) after treatment showed that chitosan and silver nanoparticles at a concentration of 80 mg/mL are the most effective in killing lice. The dead rate of lice reached 100% after 15 minutes of treatment with chitosan nanoparticles and 100% in the case of silver nanoparticles after 30 minutes. The results of spraying chitosan and silver nanoparticles on the body of chickens infected with lice experimentally, based on the relative therapeutic efficacy within 30 minutes, indicated that silver nanoparticles were the most effective in completely killing lice in the group treated with a concentration of 80 mg/kg after 30 minutes, where the percentage of therapeutic efficacy was 96.7%. This was followed by chitosan nanoparticles at a concentration of 80 mg/kg, and the percentage of therapeutic efficiency was 91.5%. Chitosan and silver nanocomposite have a promising effect in the elimination of lice infestation in chickens.