• 대한기계학회논문집B
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• 제21권11호
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• pp.1458-1465
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• 1997

This study investigated the effects of pressure on the growth of an impinging spray. We obtained the frozen images which were scattered by Nd ; YAG laser light (pulse width : 7 ns) using synchronization circuit made in the laboratory. For an impinging spray a growth of the penetration length was progressed with increase of the injection pressure but an ambient pressure restrained its growth. The effect of an ambient pressure on penetration was larger than that of an injection pressure. The pressure ratio had an effect on the penetration growth rate. The thickness growth rate depended on both the injection pressure and the ambient pressure compositively. A lower injection pressure or a higher ambient pressure was required for spatial distribution of impinging spray.

• The Korean Journal of Ceramics
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• 제2권4호
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• pp.221-225
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• 1996

In diamond synthesis by metal film growth method under high pressure and high temperature, the nucleation and growth of diamond was observed dependent on the carbon source variation from graphite powder to the heat treated powders of lamp black carbon. At the low driving force condition near equilibrium pressure and temperature line, nucleation of diamond did not occur but growth of seed diamond appeared in the synthesis from lamp black carbon while both nucleation and growth of diamond took place in the synthesis from graphite. Growth morphology change of diamond occurred from cubo-octahedron to octahedron in the synthesis from graphite but very irregular growth of seed diamond occurred in the synthesis from lamp block carbon. Lamp black carbon transformed to recrystallized graphite first and very nucleation of diamond was observed on the recrystallized graphite surface. Growth morphology of diamond on the recrystallized graphite was clear cubo-octahedron even at higher pressure departure condition from equilibrium pressure and temperature line.

• 한국세라믹학회지
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• 제37권7호
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• pp.617-624
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• 2000

Abnormal grain growth in alumina was investigated during sinter-HIP process for better understanding of pressure effect on microstructural development. Abnormal grain growth of monolithic alumina was observed near surface region rather than interior region of specimen. Finite element analysis was used to estimate the pressure distribution developed in the specimen. Pressure distribution analysis was in good agreement with grain size distributjion in the specimen. The results of finite element analysis provided that abnormal grain growth monolithic alumina was resulted from the inhomogeneous pressure distribution in the specimen. MgO addition in alumina was effective for the suppression of abnormal grain growth in alumina under inhomogeneous pressure distribution during sinter-HIP process.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 12th KACG Technical Meeting and the 4th Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.275-280
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• 1997

We have investigated the deposition characteristics of (Ni0.8Fe0.2)20Ag80 thin films as a function of chamber pressure and nitrogen flow rate with scanning electron microscopy(SEM), atomic force microscopy(AFM), XRD and $\alpha$-step. The deposition rate of these film is decreased with increasing the chamber pressure and the nitrogen flow rate. With raising the chamber pressure, the growth mode of thin film is changed from island growth to columnar one, which is probably due to energy of atom. Contrary, the nitrogen flow rate is raised, growth mode is changed from columnar to island one. According to the XRD patterns, the preferred orientation is inhibited as the nitrogen flow rate is kept above 10 sccm, but that is nearly independent on the chamber pressure. When the chamber pressure decrease or the nitrogen flow rate increase, phase separation into permoally and silver is occured.

• 한국가시화정보학회지
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• 제12권1호
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• pp.13-17
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• 2014

The growth of micro bubble has been simulated under the variation of ambient pressure. The Rayleigh-Plesset equation governs the dynamic growth and collapse of a bubble according to pressure and temperature conditions. The Rayleigh-Plesset equation was solved by 4th-order Runge-Kutta method for wide range of pressure variations. As numerical parameters, the pressure difference between initial and final pressures, and the temporal pressure gradient are changed. The results show that the pressure difference has little effect on the growth rate of the micro bubble in the inertia controlled growth region. On the other hand, the growth rate increases linearly with the increase of the pressure gradient.

• Journal of Preventive Medicine and Public Health
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• 제26권3호
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• pp.347-358
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• 1993

The purpose of this study is to analyze the relationship between the blood pressure level and their sexual maturity and physical growth in the children at puberty. For this purpose, we estimated the blood pressure, physical growth and sexual maturity of the boys of 335 and girls of 373 who are in the middle schools which are located in Kangwha County, Kyungki-Do. Both systolic and diastolic pressure were measured twice. Such physical growth as height, body weight, skin fold thickness, waist circumference, hip circumference and arm circumference were measured. The sexual maturity was estimated according to the classification of Tanner's 5-phase-sexual-maturity : in boys, their pubic hair development phase : in girls, their pubic hair and breast development phase and the menstrual experience. In the phase of the pubic hair development, the boy's sexual maturity was distributed into this; the 1 st 56.4%, the 2nd 29.3%, the 3rd 9.9%, the 4th 4.1% and the 5th 0.3%. While the girls sexual maturity was distributed into this the 1st 20.5%, the 2nd 34.9%, the 3rd 30.6% the 4th 12.6% and the 5th 1.3% in the phase of the pubic hair development, and the 1st 0.8%, the 2nd 13.7%, the 3rd 36.2%, the 4th 18.8% and the 5th 30.5% in the phase of the breast development. This indicated that the girls sexual maturity was higher than those of the boys. The girls menstrual experience rate accounted to the 58.2%. In order to see the relationship between the children's sexual maturity and blood pressure level, we regress blood pressure level on physical growth (i.e., height, BMI) and sexual maturity. Sexual maturity in treates as dummy variables. As the resulf of this analysis, the boys' sexual maturity has nothing to do with the blood pressure either systolic or diastolic. But the girl's systolic pressure was statistically significant ; the 9% of the physical growth, the 5% of the pubic hair development and the 4% of the breast development in sexual maturity was explained. In the girls' diastolic pressure, only their pubic hair development was statistically significant ; the 7% of the physical growth and the 7% of the pubic hair development in the diastolic was explained and the 5% of the physical growth in the diastolic Korotokoff phase IV and the 2% of the pubic hair development in the diastic Korotokoff phase was explained, especially, the girls exprienced menstruation, their systolic and diastolic pressure were significantly high (P<0.01). Conclusively, in the first grade children attending middle schools who are in the early process of the sexual development, the sexual maturity was not related to blood pressure level, on the other hand, the blood pressure level of the girls who are more sexual development than those of the boys' have something to do with sexual maturity and physical growth.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.614-614
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• 2013

The effect of graphene growth parameters on the number of graphene layers were systematically studied and growth mechanism on copper substrate was proposed. Parameters that could affect the thickness of graphene growth include the pressure in the system, gas flow rate, growth pressure, growth temperature, and cooling rate. We hypothesis that the partial pressure of both the carbon sources and hydrogen gas in the growth process, which is set by the total pressure and the mole fraction of the feedstock, could be the factor that controls the thickness of the graphene. A synthetic method to produce such large area graphene films with precise thickness from mono- to few-layer would be ideal for chemists and physicists to explore the promising electronic applications of these materials. Here, large-area uniform mono-, bi-, and few-layer graphene films were successfully synthesized on copper surface in selective growth windows, with a finely tuned total pressure and $CH_4$/$H_{2gas}$ ratio. Our findings may facilitate both the large-area synthesis of well-controlled graphene features and wide range of applications of graphene.

• Archives of Plastic Surgery
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• 제35권1호
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• pp.92-95
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• 2008

Purpose: Heterotopic ossification in pressure sore patients is reported to rarely develop, but once it occurs, it frequently causes joint stiffness and mobilization restriction. The aim of this article is to report our experience of atypical bone growing at femur neck fracture site with chronic, extensive pressure sore in patient with paraplegia secondary to spinal injury. Methods: A 28-year-old male patient presented with atypical bone growth at femur neck fracture site with pressure sore. He had undergone atypical growth bone removal and separation of united iliac bone and femur, and then pressure sore was covered by advanced rotation flap. Results: The patient mobilized hip joint and rode in a wheelchair. Complications such as dehiscence, infection, hematoma and flap necrosis did not occur. Conclusion: We experienced successful correction of atypical bone growth removal and recovery of pressure sore. We report our experience of atypical bone growth of fracture site and the related literature was reviewed.

• The Korean Journal of Ecology
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• 제17권2호
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• pp.149-157
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• 1994

To investigate the causes of distribution of Kummerowia striata (Thunb.) Schindl. mostly restricted on the roadside and reclaimed land, plant growth was analyzed under different of tread-pressures: $P_1$(10 times/day, $16.34Kg/cm^2$), $P_2$(20 times/day, $31.52 Kg/cm^2$), $P_3$(30 times/day, $40.79 kg/cm^2$) and the control $P_c$(0 times/day, $3.73 Kg/cm^2$). The matter production in the $P_1$decreased compared with that in the $P_c$, and those in the $P_2$and $P_3$ continuously decreased so that its length growth gradually decreased and, in particular, the growth of leaves and nodule was suppressed. The number of leaves and roots tended to increase in the $P_2$and $P_3$. The water contents of roots following the increase of tread-pressure increased continuously. Following the increase of tread-pressure, T/R ratio and C/F ratio tended to increase. Kummerowia striata showed the highest growth in the $P_c$ and showed 26% relative growth in the $P_1$compared with that in the $P_c$. This plant showed 8% relative growth in the $P_3$, which is excess to the tread-pressure $21Kg/cm^2$, the limit of growth in the plant. Because this plant grew continuously in the P$_3$, the tread-pressure is regarded as an important factor affecting the roadside distribution of this plant.

• 한국버섯학회지
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• 제15권4호
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• pp.164-167
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• 2017

Biological efficiency (BE), the ratio of fresh mushrooms harvested per dry substrate weight, expressed as the percentage of Lentinula edodes, also known as shiitake, was determined using the 'Sanjo 701' strain stored in the Department of Mushroom at the Korea National College of Agriculture and Fisheries. The mycelia were grown in glass columns with varying levels of moisture content and varying mixing periods of 0.5, 1, 2, and 3 hours. The substrate was sterilized using a steam pressure autoclave sterilizer at normal and high pressure to avoid contamination. The results showed that mycelial growth (126 mm/15 days) was optimized at 55% moisture content. The best mycelial growth of 117 mm/15 days was obtained with 2 hours of mixing time. Normal pressure sterilization yielded better results with mycelial growth of 96 mm/15 days at $100^{\circ}C$ compared to 88 mm /15 days with sterilization at $121^{\circ}C$. Mycelial density was higher, i.e. 3(+++), with normal pressure sterilization compared to 2(++) with high pressure sterilization. Furthermore, sawdust mixed with 5% woodchips increased the substrate porosity and yielded higher mycelial growth. Thus, we demonstrated that the optimum harvest or potential increased yield of shiitake can be obtained by modulating moisture content, mixing time, and substrate porosity.