• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.540-540
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• 1994

The effect of diets(high fat, high fat high energy, pectin, cellulose) on lipid metabolism were in 70 male rats for 8 weeks. The rats were assigned to either a control(C), high fat (HF) or high fat high energy(HFHE)group for 4 wks. During the next 4wks, reassigned to one of three treatments(high fat, pectin, cellulose) in the HF group and one of three treatment (hign fat high energy, pectin, cellulose) in the HFHE group. Therefore, the total treatment group became 7 (C, HF, HF-P, HF-C, HFHE, HFHE-P, HFHE-C). Parameters evaluated and compared for each diet were body weight, total energy intake, Feed Efficiency Ratio (F.E.R), total lipid, total cholesterol (TC), HDL-cholesterol(HDL-C), HDL-C/TC, triglyceride (TG), phospholipid in serum, and changes in liver and spleen. The results are surmmarized as follows ; 1. There were no signiticant differences in boby weight gain among the groups. 2. Total energy intake was higher in the C group than other groups. Feed Efficiency Ratio (F.E.R) was higher in the HFHE group than other groups. 3. There was no significant difference in the weight gain of liver (100g/B.W.) among the groups. However, the weight gain of spleen (100g/B.W.) was gigher in the C group than other groups (HF and HFHE). 4. Total lipid, TC, TG, and phospholipid increased significantly in all groups for the first 4 wks. However, after 8 wks, pectin and cellulose supplementation groups decreased significantly. Therefore, we can conclude that the HF and the HFHE diet led to increase lipids concentration and the pectin and the cellulose treatments decreased lipids concentration in serum. However, the pectin treatment had greater effect than the cellulose treatment.

• Journal of Powder Materials
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• v.18 no.3
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• pp.226-237
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• 2011

W-ZrC and W-HfC composite powders were fabricated by the Plasma Alloying & Spheroidization (PAS) method and the powders were sprayed into hybrid coating layers by using Low Vacuum Plasma Spray (LVPS) process, respectively. Microstructure, mechanical properties, and ablation characteristics of the fabricated coating layers were investigated. The LVPS process led to successful production of W-Carbide hybrid coatings, approximately 400 ${\mu}M$ or above in thickness. As the substrate preheating temperature increased from $870^{\circ}C$ to $917^{\circ}C$, the hardness of the W-ZrC coating layer increased due to decreased porosity. Vickers hardness showed higher value (about 108.4 HV) in W-ZrC hybrid coating material compared to that of W-HfC while adhesive strength was found to be similar in both coating layers. The plasma torch test revealed good ablation resistance of the W-Carbide hybrid coating layers. The relatively high performance W-ZrC coating layer at the elevated temperature is thought to be attributed to both the strengthening effect of ZrC particle remained in the layer and the formation of ZrO2 phase with high temperature stability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.163-166
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• 2002

We investigated structural and electrical properties of Metal-Oxide-Semiconductor(MOS) structure using Hafnium $oxide(HfO_{2})$ as high-k gate dielectric material. $HfO_{2}$ films are ultrathin gate dielectric material witch have a thickness less than 2.0nm， so it is spotlighted to be substituted $SiO_{2}$ as gate dielectric material. In this paper We have grown $HfO_{2}$ films with pt electrode on P-type Silicon substrate by RF magnetron sputtering system using $HfO_{2}$ target and oserved the property of semiconductor-oxide interface. Using pt electrode, it is necessary to be annealed at ${300^{\circ}C}$. This process is to increase an adhesion ratio between $HfO_{2}$ films with pt electrode. In film deposition process, the deposition time of $HfO_{2}$ films is an important parameter. Structura1 properties are invetigated by AES depth profile, and electrical properties by Capacitance-Voltage characteristic. Interface trap density are measured to observe the interface between $HfO_{2}$ with Si using High-frequency(1MHz) C-V and Quasi - static C-V characteristic.

• Journal of Nutrition and Health
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• v.27 no.2
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• pp.119-126
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• 1994

The effect of diets(high fat, high fat high energy, pectin, cellulose) on adipocyte of epididymal fat pads were investigated in 70 male rats for 8 weeks. The rats were assigned to a control(C), high fat(HF) and high fat high energy(HFHE) group for 4 wks. During the next 4 wks, reassigned to one of three treatments (high fat, pectin supplemented, cellulose supplemented) in the HF group and one of three treatment (high fat high energy, pectin, cellulose) in the HFHE group. Therefore, the total experimental groups were 7 (C, HF, HF-P, HF-C, HFHE, HFHE-P, HFHE-C). Parameters evaluated and compared for each diet were body weight, total energy intake, feed efficiency ratio and weight changes in epididymal fat pads. The results are summarized as follows ; 1) There was no significant difference in body weight gain among the groups. 2) Total energy intake was higher in the C group than other groups. 3) Feed efficiency ratio (F.E.R) of the HF and HFHE groups were greater than C group(2, 4 weeks). However, there were no significant differences between the HF and HFHE groups. 4) Epididymal fat pads(EFP 100g/B.W) of the FH and HFHE groups were higher than C group (2, 4 weeks). However, there were no significant differences between the HF and HFHE groups. There was no significant difference in weight gain of epididymal fat pads among the groups(8 weeks). 5) Cell number and cell size of epididymal fat pads of the HF and HFHE groups were higher than the C group. The pectin and the cellulose supplementation groups decreased cell number and cell size of epididymal fat pads. Especially, the pectin supplementation group decreased than the cellulose supplementation in HFHE group. Therefore, we can concluded that the HF and the HFHE diet has no effect on the epididymal fat pads.

• Korean Journal of Materials Research
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• v.17 no.2
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• pp.96-99
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• 2007

The effects of post-annealing of high-k $HfO_2$ thin films grown by atomic layer deposition method were investigated by the annealing treatments of $400-600^{\circ}C$. $Pt/HfO_2/p-Si\;MOS$ capacitor structures were fabricated, and then the capacitance-voltage and current-voltage characteristics were measured to analyze the electrical characteristics of dielectric layers. The X-ray diffraction analyses revealed that the $500^{\circ}C-annealed\;HfO_2$ film remained to be amorphous, and the $600^{\circ}C-annealed\;HfO_2$ film was crystallized. The annealing treatment at $500^{\circ}C$ resulted in the highest capacitance and the lowest leakage current due to the reduction of defects in the $HfO_2$ films and non-crystallization. Our results suggest that post-annealing treatments are a critical factor in improving the characteristics of gate dielectric layer.

• Journal of the Korean institute of surface engineering
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• v.30 no.6
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• pp.374-381
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• 1997

We have studied the effect of the interface between tungsten silicide and polysilicon the silicide reaction. The results showed that the cleaning of the silicon surface prior to the deposition of tungsten silicide affected the interface properties, thereby leading to the difference in the resistivity and surface morhpology of tungsten silicide. Compared with HF cleaning, the use of SCl cleaning yielded higher resistivity of tungsten silicide at the low anneal temperature (up to $900^{\circ}C$). However, furtherature to $1000^{\circ}C$ reduced the resistivity significantly, similar to that obtained with HF cleaning. It was also observed that the annealing of WSix/HF-cleaned poly-si allowed the formation of bucking weve (partially decohesion area) on the surface. In contrast, the use of SCl celaning did not produce the buckling waves on the surface. Also the presence of 200$\AA$ -thick TiW between tungsten silicide and HF-cleaned poly-Si effectively prevented the formation of the waves. However, high-temperature annealing of WSix/200A-TiW/Poly-Si allowed the excess silicon in tungsten silicide to precipitate inside the silcide, causing the slight increase of the resistivity after annealing at $1050^{\circ}C$.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.575-579
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• 2023

In this work, pure W and W-0.5wt%HfC alloy (WHC05) were fabricated by sintering and hot-rolling following the same processing route. After exposing to a high flux deuterium plasma irradiation with the D⁺ flux to three fluences of 6.00 × 10²⁴, 2.70 × 10²⁵ and 7.02 × 10²⁵ D/m², the evolution of surface morphology, deuterium retention and hardening behaviors in pure W and WHC05 has been studied. The SEM results show the formation of D blisters on the irradiated area, and with the increase of D implantation, the size of these blisters increases from 200 ~ 500 nm (2.70 × 10²⁵ D/m²) to 1 ~ 2 ㎛ (7.02 × 10²⁵ D/m²) in WHC05 and from 1 ~ 2 ㎛ (2.70 × 10²⁵ D/m²) to > 3 ㎛ (7.02 × 10²⁵ D/m²) in pure W, respectively. A higher D retention and obvious hardening are observed in pure W than that of the WHC05 alloy, indicating an improve radiation resistance in WHC05 compared to pure W.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.245.2-245.2
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• 2007

• Analytical Science and Technology
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• v.15 no.1
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• pp.15-19
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• 2002

The pretreatment of tungsten added $BaTiO_x$ ceramics was performed to improve the recovery of Ba, Ti and W. $BaTiO_x$ ceramics were digested with HF : HCl ( 1 : 2 ) mixture in an acid digestion bomb at $220^{\circ}C$ for 3 hrs. The concentration of Ba, Ti and W were determined by ICP-AES. Recoveries of Ba, Ti and W were 99.6%, 99.8% and 99.2%, respectively. And their C.V. values were 1.02%, 0.73% and 1.79%. Using this method, the analytical results of Ba, Ti and W for a real sample were obainted to be 25.9% (w/w), 38.8% (w/w) and 3.31% (w/w), respectively.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.471-481
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• 2009

This study is deal with the high frequency induction hardening (HF at $850^{\circ}C$, 120kHz & 50kW condition) SM45C steel. (1) The HF specimen which was tempered at $150^{\circ}C$, did not appear any tempering effect. A brittle fracture occurred at rounded area of the tensile specimen. AE amplitude distribution showed between 45~60dB. (2) The HF specimen which was tempered at $300^{\circ}C$, slip and fracture occurred at the hole area of the tensile specimen. As it passes the yield point, the AE energy increased intermittently and AE amplitude distribution showed between 70~85dB. In addition, after the maximum tensile load, it showed high amplitude and energy distribution. The AE amplitude showed between 45~70dB. (3) The HF specimen which was tempered at $450^{\circ}C$, a brittle fracture occurred as if it is torn in the direction of $45^{\circ}$ on parallel area over the both sides of the tensile specimen, which led to several peak to be appeared in AE energy. It was found that the AE amplitude was relatively low and the AE energy was high.