• 한국수소및신에너지학회논문집
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• 제30권1호
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• pp.43-48
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• 2019

This study investigates the electrochemical characteristics of the hybrid cell that combined the advantageous characteristics of Li secondary battery and supercapacitor, high energy density and high power density, respectively. Electrochemical behaviors of the hybrid cell was characterized by charge/discharge, cycle and impedance tests. The hybrid cell using Li secondary battery and supercapacitor had better discharge capacity and cycle performance than that of using Li secondary battery only. Proper design of such a hybrid cell system is expected to result in substantial benefits to the well being of the Li secondary battery. The hybrid cell involving Li secondary battery for high energy density and supercapacitor for high power density may be the possible solution for future energy storage system.

• 한국자기학회지
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• 제5권6호
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• pp.937-946
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• 1995

본 연구에서는 NiCuZn Ferrite 제조공정의 제어를 위하여 제조공정 변수에 따른 NiCuZn Ferrite의 물성 및 자기적특성의 변화를 검토하여, 겉보기밀도(bulk density)와 초기투자율의 관계를 명확하게 하는 것을 목적으로 하였다. $700^{\circ}C$에서 3시간 하소 한 NiCuZn Ferrite를 약 60시간 볼밀링하여 약 $0.5\mu\textrm{m}$ 입자크기로 분쇄한 후 분무 건조하여 과립화하였다. 본 연구에서는 (1)NiCuZn Ferrite 과립의 크기와 성형압력 변화와 (2)일정한 성형조건에서 소성온도의 변화에 따른 성형체 및 소성체의 물성측정, 그리고 자기적 특성을 검토하였다. NiCuZn Ferrite의 green density는 과립의 크기보다는 성형압력에 더 의존하였으며, 과립의 크기가 $150\mu\textrm{m}$ 이하 일 때 성형압력이 증가 함에 따라 green density는 $2.484\;g/cm^{3}$에서 $3.002\;g/cm^{3}$로 크게 증가하 였다. NiCuZn Ferrite의 bulk density는 소성온도에 의하여 거의 직선적으로 $3.470\;g/cm^{3}$에서 $4.754\;g/cm^{3}$로 증가하였다. 성형압력 변화 및 소성온도 변화에 따른 NiCuZn Ferrite 초기투자율과 겉보기밀도 관계를 비교 검토한 결과, NiCuZn Ferrite의 초기투자율($\mu_{i}$)과 겉보기밀도($\rho$)의 관계를 $\mu_{i}=a+b_{\rho}+c_{\rho}^2$와 같이 실험식으로 표현할 수 있었다.

• 한국세라믹학회지
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• 제28권10호
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• pp.767-776
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• 1991

Effects of the additions of SiB4 as burnable poison to UO2 on the green density, densification, interdependence between density-grain growth and microstructure of sintered UO2 were studied. UO2 pellets were sintered in flowing hydrogen, at temperature 1200, 1350, 1500, and 168$0^{\circ}C$ for 3 hours and at 168$0^{\circ}C$ for 0, 1, 3, and 10 hours, respectively. Green densities were in the range of about 4.5~5.4 g/㎤, and decreased as the amount of SiB4 increased when green pellets were made by with use of a double action press at 1000 kg/$\textrm{cm}^2$. The density of sintered UO2 pellets was around 92~94% of the theoretical density and did not change significantly as the amount of SiB2 addition increased. However, the density of sintered pellets decreased with the increase in SiB4. The grain growth could be characterized in terms of two stages: Grain growth occurred with the increasing density in the first stage, whereas the second stage was characterized by the grain growth without increasing of density. A liquid phase was observed at grain boundaries and grain edges in the microstructure of sintered UO2 pellets with 5000 ppm and 10,000 ppm SiB4. This liquid, possible formed at about 168$0^{\circ}C$, did not enhance the shrinkage, but appeared to accelarate the grain growth. It seems that the second stage grain growth was due to the presence of pressurized insoluble trapped gas in isolated pores.

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.238-243
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• 1993

A self-consistent-field Green's matrix method for the calculation of electronic properties of chemisorbed system is devised and applied to the methanol on copper(110) surface. The method is based on CNDO Hartree-Fock approximation. Contour integration in the complex energy plane is used for an efficient calculation of the charge-density bond-order matrix. The information on each fragment prior to chemisorption is efficiently used and a small number of iterations are needed to reach the self-consistency. The changes of density of states and other quantities of methanol due to chemisorption are consistent with reported experimental results.

• Nutrition Research and Practice
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• 제6권2호
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• pp.106-112
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• 2012

This study was conducted to investigate the effects of $Sasa$ $quelpaertensis$ bamboo and green tea on plasma and liver lipids, platelet aggregation, and erythrocyte membrane Na channels in ovariectomized (OVX) rats. Thirty female rats were OVX, and ten female rats were sham-operated at the age of 6 weeks. The rats were divided into four groups at the age of 10 weeks and fed the experiment diets: sham-control, OVX-control, OVX-bamboo leaves (10%), or OVX-green tea leaves (10%) for four weeks. Final body weight increased significantly in the OVX groups compared with that in the sham-control, whereas body weight in the OVX-green tea group decreased significantly compared with that in the OVX-control ($P$ < 0.01). High density lipoprotein (HDL)-cholesterol level decreased in all OVX groups compared with that in the sham-control rats ($P$ < 0.05) but without a difference in plasma total cholesterol. Plasma triglycerides in the OVX-green tea group were significantly lower than those in the sham-control or OVX-control group ($P$ < 0.05). Liver triglycerides increased significantly in the OVX-control compared with those in the sham-control ($P$ < 0.01) but decreased significantly in the OVX-green tea group compared with those in the OVX-control or OVX-bamboo group ($P$ < 0.01). Platelet aggregation in both maximum and initial slope tended to be lower in all OVX rats compared with that in the sham-control rats but was not significantly different. Na-K ATPase tended to increase and Na-K cotransport tended to decrease following ovariectomy. Na-K ATPase decreased significantly in the OVX-green tea group compared with that in the OVX-control group ($P$ < 0.01), and Na-K cotransport increased significantly in the OVX-bamboo and OVX-green tea groups compared with that in the OVX-control ($P$ < 0.05). Femoral bone mineral density tended to be lower in OVX rats than that in the sham-control, whereas the green tea and bamboo leaves groups recovered bone density to some extent. The results show that ovariectomy caused an increase in body weight and liver triglycerides, and that green tea was effective for lowering body weight and triglycerides in OVX rats. Ovariectomy induced an increase in Na efflux via Na-K ATPase and a decrease in Na efflux via Na-K cotransport. Furthermore, consumption of green tea and bamboo leaves affected Na efflux channels, controlling electrolyte and body water balance.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.226-226
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• 2016

PHOLED devices which have the structure of ITO/HAT-CN(5nm)/NPB(50nm)/EML(30nm)/TPBi(10nm)/Alq3(20nm)/LiF(0.8nm)/Al(100nm) are fabricated to investigate the green emission profile in EML by using a gasket doping method. CBP and Ir(ppy)3 (2% wt) are co-deposited homogeneously as a background material of EML for green PHOLED, then a 5nm thickness of additionally doped layer by Ir(btp)2 (8% wt) is formed as a profiler of the green emission. The total thickness of the EML is maintained at 30nm while the distance of the profiler from the HTL/EML interface side (x) is changed in 5nm steps from 0nm to 25nm. As shown in Fig. 1, the green (513nm) peak from Ir(ppy)3 is not observed when Ir(btp)2 is also doped homogeneously because Ir(ppy)3 works as an gasket dopant of the Ir(btp)2 :CBP system. Therefore, in this experment, Ir(btp)2 can be used as a profiler of the green emission in CBP:Ir(ppy)3 system. The emission spectra from the PHOLED devices with different x are shown in Fig. 2. In this gasket doping system, stronger red peak means more energy transfer from green to red dopant or higher exciton density by green dopant. To find the green emission profile, the external quantum efficiency (EQE) at 3mA/cm2 for red peaks are calculated. More green light emission at near EML/HBL interface than that of HTL/EML is observed (insert of Fig. 2). This means that the higher exciton density at near EML/HBL interface in homogeneously doped CBP with Ir(ppy)3. As shown in Fig. 3, excitons can be quenched easily to HTL(NPB) because the T1 level of HTL(2.5eV) is relatively lower than that of EML(2.6eV). On the other hand, the T1 level of HBL(2.7eV) is higher than that of EML.

• 동아시아식생활학회지
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• 제20권1호
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• pp.46-53
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• 2010

The study examined the effects of dietary green tea powder supplementation on blood glucose, and plasma and liver lipid concentrations in diabetic rats. Twenty-five male Sprague-Dawley rats (body weight $200{\pm}5\;g$) were divided into two groups (diabetic and non-diabetic), which were each randomly divided into two subgroups that were fed a control and 1% green tea powder-supplemented diet. Serum and liver lipid concentrations were measured by established techniques. Low density lipoprotein-cholesterol (LDL-C) was calculated from an established equation. Body weight gain and feed efficiency ratio were lower in diabetic rats than in non-diabetic rats regardless of diet. There were no differences in weight gain in diabetic and non-diabetic rats consuming the control and green tea powder-supplemented diets. The levels of fasting plasma glucose, serum total cholesterol, triglyceride, LDL-C and atherogenic index of diabetic rats were significantly higher than that of non-diabetic rats. Conversely, the levels of high density lipoprotein-cholesterol (HDL-C) of diabetic rats was significantly lower than that of non-diabetic rats. Fasting plasma glucose, serum total cholesterol, triglyceride, LDL-C and atherogenic index were significantly lower in diabetic rats fed the green tea powder diet than in rats fed the control diet, and HDL-C was significantly higher in rats fed the green tea powder diet than in rats fed the control diet. The content of liver total cholesterol and triglyceride of diabetic rats were significantly higher than that of non-diabetic rats. Liver total cholesterol and triglyceride were significantly lower in diabetic rats fed green tea powder-supplemented diet than in rats fed the control diet. It is concluded that green tea powder supplementation positively influences blood glucose and lipid metabolism in diabetic rats. The present study, although not directly applicable to humans, may have some implications for individuals who habitually consume green tea powder.

• 아시안잔디학회지
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• 제3권1호
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• pp.5-12
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• 1989

Tiller numbers per Unit area were increased as plant density heightened followed by little difference in tiller number in 110 days after transplanting(ll0DAT), this being caused by the immediate increment of tiller since' 90DAT During the growth period, the greatest number of green leaves per unit area was attained in 90DAT of both 160-density and 200-density plots, and in l00DAT of 40-, 80-, and I 20-density plots. Thus, the period to reach the maximum green leaf number with the high plant density was earlier than with the' low plant density. The increment of plant density increased the DM weight of ahoveground part and, with 40-densitytreatment. DNI weight was increased 6.1 times as much up to 110DAT as up to 7ODAT but 2 to 2.9 times with other ehe'nsity treatments. The' rate of increase in stolon length was greatest at the period between 80 and 90DAT when DM weight of stolon showed a large increment. Meanwhile, the average number of stolon was 1.7 at 70DAT but was increased up to 10 at 110DAT probably due to accelerative appeance of Ist stolon branch since 8.0DAT. DM weight of stolon was found to exceeded that of root after 90DAT Thus it was concluded that, when turfs is estahlished from sprig. it may be desirable for first mowing practice to be made at least within l00 days after planting.

• 한국세라믹학회지
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• 제32권2호
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• pp.209-216
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• 1995

In order to investigate the effect o green microstructure on the sintering behavior and properties of AlN ceramics, samples were prepared by slip casting and dry pressing. The slip cast samples had high green density, fine pore size and narrow pore size distribution. They showed much higher sinterability and more homogeneous sintered microstructure compared to the dry pressed samples. Both increased thermal conductivity and flexural strength for samples prepared by slip casting could be attributed to the improved microstructural homogeneity with isolated second phase(s).

• 한국세라믹학회지
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• 제31권12호
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• pp.1467-1474
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• 1994

The effects of the dispersion, drying, and binder burning-out on the green-microstructures of gelcasted alumina were studied. The slip consisting of 55 vol% alumina powder and 5 wt% organic materials was well-dispersed by adding 0.28 wt% polyelectrolyte polymer. Green bodies were dried at >85% relative humidity at room temperature. Green-microstructures were observed to be depended on the heating rate during binder burnout. Constant drying rate was not observed in drying process of gelcasted alumina. Sintered body showed its relative density higher than 99% when it was sintered at 1$600^{\circ}C$ for 2 hours.