• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.163-168
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• 2014

Bottom gate thin-film transistors were fabricated using solution processed IGZO channel layers with various gallium composition ratios that were annealed on a hot plate. Increasing the gallium ratio from 0.1 to 0.6 induced a threshold voltage shift in the electrical characteristics, whereas the molar ratio of In:Zn was fixed to 1:1. Among the devices, the IGZO-TFTs with gallium ratios of 0.4 and 0.5 exhibited suitable switching characteristics with low off-current and low SS values. The IGZO-TFTs prepared from IGZO films with a gallium ratio of 0.4 showed a mobility, on/off current ratio, threshold voltage, and subthreshold swing value of $0.1135cm^2/V{\cdot}s$, ${\sim}10^6$, 0.8 V, and 0.69 V/dec, respectively. IGZO-TFTs annealed at $300^{\circ}C$, $350^{\circ}C$, and $400^{\circ}C$ were also fabricated. Annealing at lower temperatures induced a positive shift in the threshold voltage and produced inferior electrical properties.

• 한국환경보건학회지
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• 제27권4호
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• pp.41-46
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• 2001

Trihalomethane(THMs) levels in drinking tap water, indoor swimming pool water and industrial effluent in Kunsan area were surveyed in this study. During experimental period, the monthly averages of THMs in drinking tap water from Keumkang wide-area supply ranged from 15$\mu\textrm{g}$/ι/to 50 $\mu\textrm{g}$ showing the highest level in summer. 3 indoor swimming pools showed the monthly average levels of THMs formation ranging from 8$\mu\textrm{g}$/ι/to 20$\mu\textrm{g}$/ι and the pool under public management seemed to maintain its water quality more stable than those under private management THMs concentrations in the effluents. discharged from 10 manufacturing companies, ranged from N.D. to 95$\mu\textrm{g}$/ι and it was estimated that the overall THMs level discharged front those manufacturing companies is not high, reflecting the traces recorded for most effluents. The composition ratios of individual THMs for industrial effluents showed a difference from those for drinking water and swimming pool water, along with their wide variations according to the company and relatively high composition ratios of Br substituents.

• 공업화학
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• 제7권4호
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• pp.623-632
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• 1996

코모노머와 코모노머의 조성을 변화시켜 프로필렌/부텐-1 및 트로필렌/헥센-1의 공중합을 실시하여 반응성비, 용융점 및 폴리머 형상등을 관찰하였다. 공중합에 사용한 촉매는 담체로서 실리카(촉매 I)와 마그네슘(촉매 II)을 사용한 고활성촉매이다. 코모노머의 조성이 증가함에 따라 폴리머의 용융점이 낮아지며, 또한 코모노머의 조성이 프로필렌/부텐-1 공중합의 경우에는 40% 이상, 프로필렌/헥센-1 공중합의 경우에는 80% 이상이면 폴리머의 형상이 무정형화 되어진다. 반응성비는 Fineman-Ross법과 Kelen-$T{\ddot{u}}d{\tilde{o}}s$법으로 구하였다.

• Structural Engineering and Mechanics
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• 제82권5호
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• pp.571-585
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• 2022

As a vital component of power grids, long-span transmission tower-line systems are vulnerable to wind load excitation due to their high flexibility and low structural damping. Therefore, it is essential to reduce wind-induced responses of tower-line coupling systems to ensure their safe and reliable operation. To this end, a shape memory alloy-bidirectional tuned mass damper (SMA-BTMD) is proposed in this study to reduce wind-induced vibrations of long-span transmission tower-line systems. A 1220 m Songhua River long-span transmission system is selected as the primary structure and modeled using ANSYS software. The vibration suppression performance of an optimized SMA-BTMD attached to the transmission tower is evaluated and compared with the effects of a conventional bidirectional tuned mass damper. Furthermore, the impacts of frequency ratios and SMA composition on the vibration reduction performance of the SMA-BTMD are evaluated. The results show that the SMA-BTMD provides superior vibration control of the long-span transmission tower-line system. In addition, changes in frequency ratios and SMA composition have a substantial impact on the vibration suppression effects of the SMA-BTMD. This research can provide a reference for the practical engineering application of the SMA-BTMD developed in this study.

• Journal of Electrochemical Science and Technology
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• 제9권1호
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• pp.78-83
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• 2018

In this study, we investigated the composition of an electrolytic Fe phosphide at different synthesis temperatures. We found that the ratio of Fe in the electrodeposit increases with synthesis temperature, whereas the oxygen content introduced into the electrodeposit by the atmospheric oxidation of Fe decreases. The aim of this study was to identify the reason for this effect. For this purpose, the ratio of Fe and P in the electrodeposits prepared at different temperatures was analyzed in depth. In addition, the types and ratios of Fe phosphide phases were considered. It was proved that with increase in temperature, a significant amount of Fe reacted with P to form Fe phosphide phases, and consequently, the amount of residual pure Fe that would react directly with oxygen decreased.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.170-173
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• 2006

[ $CuInS_2$ ] filims were appeared from 0.84 to 1.27 of Cu/In composition ratio and sulfur composition ratios of $CuInS_2$ thin films fabricated, Also when Cu/In composition ratio was 1.03, $CuInS_2$ thin film with chalcopyrite structure had the highest XRD peak (112). And lattice constant (a) of and grain size of the film tin s ambient were appeared a little larger than those in only Vacuum The films in S ambient were p-type with resistive of around $10^{-1}{\Omega}cm$ and optical energy band gaps of the films in S ambient were appeared a little larger than those in only Vacuum. Analysis of the optical energy band gap of $CuInS_2$ thin films a value of 1.53eV.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.75-82
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• 2010

The biometry, morphological properties and chemical composition of bagasse, corn, sunflower, rice, and rapeseed residues plants were analyzed. The results revealed differences in biometry properties and chemical composition of the different types of agricultural resides investigated. The greatest proportion of fiber length (1.32 mm) and cellulose (55.56%) was found in residues of bagasse plants, with a low ash (1.78%) and lignin (20.5%). The lignin of all types of agricultural resides was less than hardwood and softwood. In addition, the rice and rapeseed residues plants had highest amount of ash and extractive component. The slenderness and flexibility ratios of the all types of agricultural resides fibers were similar to some of hardwood and softwood species.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.231-237
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• 1994

Three concentrations of P (0.33, 0.43 and 0.54%) and two concentrations of Ca (0.60 and 0.97%) in ration dry matter were evaluated for effects on dry matter intake and on milk yield and composition using 24 Holstein cows. Cows were arranged in a $3{\times}2$ factorial experiment as an incomplete randomized block design with three 28-day periods. Each cow consumed at least one ration with each concentration of Ca. Dry matter intake, yield of 3.5% Fat Corrected Milk, and milk composition were not affected by concentration of P, but milk yield was greater when lowest concentration of P was fed (22.8 vs. 22.1 kg/day; p<0.07). Cows fed rations containing 0.60% Ca had greater milk (22.7 vs. 21.9 kg/day; p<0.02) and 3.5% Fat Corrected Milk yields (p<0.03) and slightly greater protein content than when fed 0.97% Ca. Dietary Ca:P ratios between 1.1:1 and 2.9:1 had no effect on dry matter intake, milk yield, or composition. Concentrations of P in plasma were within the normal range for all rations. Because cows had high dry matter intake, mean daily intakes of both P and Ca were greater than required for their level of milk yield.

• Asian-Australasian Journal of Animal Sciences
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• 제30권4호
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• pp.470-478
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• 2017

Objective: This study aims to evaluate the chemical composition, fermentation quality and in vitro ruminal fermentation of various ratios and storage periods of liquid brewer's yeast (LBY) mixed with cassava pulp (CVP). Methods: Four mixtures of fresh LBY and CVP were made (LBY0, LBY10, LBY20, and LBY30 for LBY:CVP at 0:100, 10:90, 20:80, and 30:70, respectively) on a fresh matter basis, in 500 g in plastic bags and stored at 30 to $32^{\circ}C$. After storage, the bags were opened weekly from weeks 0 to 4. Fermentation quality and in vitro gas production (IVGP) were determined, as well as the dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber, acid detergent fiber and acid detergent lignin contents. Results: The contents of CP and EE increased, whereas all other components decreased, in proportion to LBY inclusion (p<0.01). The DM and OM contents gradually decreased in weeks 3 and 4 (p<0.05), while EE contents were lowest in week 0. The pH, ammonia nitrogen per total nitrogen ($NH_3-N/TN$) and V-score in each mixture and storage period demonstrated superior fermentation quality ($pH{\leq}4.2$, $NH_3-N/TN{\leq}12.5%$, and V-score>90%). The pH increased and $NH_3-N/TN$ decreased, with proportionate increases of LBY, whereas the pH decreased and $NH_3-N/TN$ increased, as the storage periods were extended (p<0.01). Although IVGP decreased in proportion to the amount of LBY inclusion (p<0.01), in vitro organic matter digestibility (IVOMD) was unaffected by the mixture ratios. The highest IVGP and IVOMD were observed in week 0 (p<0.01). Conclusion: The inclusion of LBY (as high as 30%) into CVP improves the chemical composition of the mixture, thereby increasing the CP content, while decreasing IVGP, without decreasing fermentation quality and IVOMD. In addition, a preservation period of up to four weeks can guarantee superior fermentation quality in all types of mixtures. Therefore, we recommend limiting the use of CVP as a feed ingredient, given its low nutritional value and improving feed quality with the inclusion of LBY.

• 한국환경보건학회지
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• 제48권2호
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• pp.66-74
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• 2022

Background: The health effects of particulate matter (PM_2.5) bonded with various harmful chemicals differ based on their composition, so investigating and managing their concentrations and composition is vital for long-term management. As industrial complexes emit considerable quantities of pollutants, higher PM_2.5 concentrations and chemical component effects are expected than in other places. Objectives: We investigated the concentration distribution ratios of PM_2.5 chemical components to provide basic data to inform future major emissions control and PM_2.5 reduction measures in industrial complexes. Methods: We monitored five sites near the Ansan and Siheung industrial complexes from August 2020 to July 2021. Samples were collected and analyzed twice per week in spring/winter and once per week in summer/autumn according to the National Institute of Environmental Research in the Ministry of Environments' Air Pollution Monitoring Network Installation and Operation Guidelines. We investigated and compared composition ratios of 29 ions, carbon, and elemental components in PM_2.5. Results: The analysis of PM_2.5 components at the five sites revealed that ion components accounted for the greatest total mass at approximately 50% while carbon components and elemental components contributed 23~28% and 8~10%, respectively. Among the ionic components, NO₃^- occupies the greatest proportion. OC occupies the greatest proportion of the carbon components and sulphur occupies the greatest proportion of elemental components. Conclusions: This study investigated the concentration distribution ratios of PM_2.5 chemical components in industrial complexes. We believe these results provide basic chemical component concentration ratio data for establishing future air management policies and plans for the Ansan and Siheung industrial complexes.