• Journal of Nutrition and Health
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• 제29권7호
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• pp.788-805
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• 1996

This study was performed to investigate effects of examination-stress and protein supplementation on nitrogen metabolism and blood protein levels of Korean college students. Experiment was conducted at the beginning of a academic term and during midterm examination. During midterm examination, subjects were classified into two groups randomly : protein supplemental group(male n=6, female n=10) and placebo group(male n=4, female n=9). Protein capsules(2g/day) above 10% of indispensible amino acids requirement estimates were given to supplemental group for 10 days. At the begining of the term, male students(n=12) ingested 223.15mgN/kg/d, excreted 20.7mgN/kg/d in feces, and excreted 94.31mgN/kg/d in urine. Their apparent protein protein digestibility was 90.72%, true N balance was +100.11mgN/kg/d, and the mean maintenance N requirement of mixed Korena diet calculated was 112.13mgN/kg/d. Female students(n=19) ingested 171.44mgN/kg/d, excreted 22.13mgN/kg/d in feces, and excreted 122.92mgN/kg/d in urine. Their apparent protein digestibility was 86.76%, true N blance was + 18.39mgN/kg/d, and the mean maintenance N requirement calculated was 135.31mgN/kg/d. Blood levels of serum total protein, albumin, and BUN were within normal range. During midterm examination, fecal and urinary N excretions of female subjects(n=19) were increased, especially urea N markedly, and urea N/creatinine N ratio was augumented significantly. Apparent protein digestibility of male subjects(n=10) was decreased. Examination-stress showed 8.05mgN/kg/d (7.2%) increase of mean maintenance N requirement in male and 8.55mgN/kg/d(6.3%) increase in female students in comparison with that of the beginning of the term. Serum total protein and albumin levels showed no significant change, but serum transferrin level of female were decreased significantly. During midterm examination, females supplemented with protein capsules(2g/d)had no significant increase in fecal and urinary N excretions.

• 한국작물학회지
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• 제54권2호
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• pp.225-230
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• 2009

본 연구는 생식생장기의 습해에 의한 콩 수량과 질소 및 여러 가지 양분흡수에 미치는 영향을 알고자 지하수위를 0 cm, 10 cm 및 40 cm로 달리하여 조사하였다. 지하수위가 높음에 따라 생육과 수량은 감소되었으며 다원콩의 감소정도가 풍산나물콩보다 더 크게 나타났다. 질소흡수량은 지하수위가 높을수록 감소되었으며 수량과의 상관관계는 $R^2=0.872$로 고도로 유의한 정의상관을 보였다. K함량은 지하수위 높이에 큰 차이를 보이지 않았으며(뿌리 제외), Ca함량은 감소(잎, 줄기) 또는 증가(뿌리)하였지만 Mn과 Fe 함량은 지하수위가 높을수록 급격히 증가하였으며 다원콩이 풍산나물콩보다 높은 함량을 보였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.139-141
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• 2007

Compression tests were carried out to investigate morphologies of compressed specimen, deformation microstructure and stress-strain relation in high-nitrogen austenite stainless steel. Tests were performed under a wide range of temperature and, with true strain rates up to $\dot{\varepsilon}$ =0.05, 0.1, 0.5 and $1.0s^{-1}$. The activation energy of loading force was equal to plastic deformation energy within the temperature range of $900^{\circ}C$ to $1250^{\circ}C$. Dynamically recrystallized grain size decreased with an increasing strain rate and temperature. Flow stresses and deformation microstructures, were used to quantify the critical strain rate and recrystallized grain size. The grain size versus strain rate-temperature map obtained in the study was in good agreement with the deformation microstructures of compressed specimens.

• Progress in Superconductivity
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• 제11권1호
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• pp.52-56
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• 2009

Temperature distributions and thermal stresses were calculated and analyzed to investigate the effect of the artificial holes to the transient behaviors of the superconductors which was cooled in liquid nitrogen. Three dimensional finite element method was used to calculated the transient temperature and thermal stresses in the superconductors. The cooling speed of the superconductors with holes is faster than those without holes. Because the thermal stresses calculated in the superconductors can be relaxed by the distributed holes, the volume of the peak tensile stress decreases during the cooling in liquid nitrogen. If optimal metal, which can maintain the relaxation of thermal stresses, is used to fill and reinforce the artificial holes, the probability of failure of the superconductors may be decreased by the decrease of volume of peak tensile stress.

• 전자공학회논문지A
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• 제32A권12호
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• pp.115-121
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• 1995

A mask for x-ray lithography is fabricated with SiN membrane and WTi absorber. SiN membrane is deposited by plasma enhanced chemical vapor deposition, and the stress of SiN membrane is controlled to be less than 100 MPa by rapid thermal annealing. WTi absorber is reactively deposited by DC-magnetron type sputter, and the working gases are argon and nitrogen. Added nitrogen is contributed to the stress of WTi absorber. The stress of WTi absorber is controlled to be less than $\pm$ 100 MPa by controlling the deposition pressure. 10$\mu$m WTi pattern is delineated on SiN membrane by dry etching technique.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.3-6
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• 2003

The electrical and mechanical properties of dielectric paper and cable at cryogenic temperature have been investigated to optimum insulating design of high-Tc superconducting(HTS) cable. From the results, Tensile strength of PPLP in liquid nitrogen was high more than that of air, but tensile strain could know that decrease sharply. According as tensile strength increases, the breakdown stress of PPLP in liquid nitrogen was decreased because PPLP was degradated. According as bending radius multiple is decrese, breakdown voltage decreased sharply. And bending radius multiple is thought that more than about 25 is suitable.

• 한국진공학회지
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• 제6권4호
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• pp.354-358
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• 1997

다양한 질소 압력, 플라즈마 파워 상태에서 사파이어 기판위에 전자 사이클로트론 공명 MBE로 제작한 wurtzite GaN의 결정특성을 XRD의 반치폭, 주사전자 현미경으로 조 사하였다. 질소 압력은 XRD의 반치폭에 커다란 영향을 미치고 있으며 최적 질소 압력에서 제작한 시료에는 높은 dislocation density를 포함하고 있음을 알았다. 이러한 결과들은 갈륨 질소의 결정질(crystal quality)은 플라즈마 상태에 매우 민감하며 또한 스트레스 완화는 V/ III비에 의존하고 있음을 나타낸다. 그렇지만 사파이어 기판의 nitridation은 스트레스 완화에 커다란 영향을 미치지 않고 있었다.

• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.103-107
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• 2022

Scaffolds are the structures that safely protect sensors in various parts of the body. Because of scaffolds must protect sensors from load, the tensile strength of the scaffolds must be higher than 750 kgf/cm². Currently, the tensile strength of scaffolds made with the 3d printer is 714 kgf/cm². We confirm that the tensile strength of the scaffolds increase using air with high nitrogen concentration. In this study, we conducted experiments to find nitrogen concentrations in which the tensile strength of the specimen is higher than 750 kgf/cm². The nitrogen control device and the nitrogen concentration sensor were installed in the chamber type 3d printer. The nitrogen concentration inside the 3d printer was changed by 5 % from 80 % to 100 %. Specimens of ASTM D 638 standard were produced under changed nitrogen concentration. We measured the tensile strength of specimens. We compared the tensile strength of specimens produced under each nitrogen concentration. We confirmed that when air with nitrogen concentration of 90 % was used, the tensile strength of scaffolds were 762 kgf/cm².

• Journal of Microbiology and Biotechnology
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• 제33권3호
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• pp.310-318
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• 2023

Microalgae are attracting much attention as promising, eco-friendly producers of bioenergy due to their fast growth, absorption of carbon dioxide from the atmosphere, and production capacity in wastewater and salt water. However, microalgae can only accumulate large quantities of lipid in abiotic stress, which reduces productivity by decreasing cell growth. In this study, the strategy was investigated to increase cell viability and lipid production by overexpressing S-adenosylmethionine (SAM) synthetase (SAMS) in the microalga Chlamydomonas reinhardtii. SAM is a substance that plays an important role in various intracellular biochemical reactions, such as cell proliferation and stress response, and the overexpression of SAMS could allow cells to ithstand the abiotic stress and increase productivity. Compared to wild-type C. reinhardtii, recombinant cells overexpressing SAMS grew 1.56-fold faster and produced 1.51-fold more lipids in a nitrogen-depleted medium. Furthermore, under saline-stress conditions, the survival rate and lipid accumulation were 1.56 and 2.04 times higher in the SAMS-overexpressing strain, respectively. These results suggest that the overexpression of SAMS in recombinant C. reinhardtii has high potential in the industrial-scale production of biofuels and various other high-value-added materials.

• 대한기계학회논문집A
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• 제26권7호
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• pp.1317-1323
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• 2002

This paper describes the comparison of calculated effective stress with experimental one in austenitic heat resistant steels, STS310J1TB and STS310S with and without a small amount of Nb and N. Based on a solute atoms diffusion model, contribution from soluble nitrogen to the high-temperature strength was numerically examined for austenitic heat-resisting Fe-Cr-Ni-N(STS310J1TB) and Fe-Cr-Ni (STS310S) alloys. The solute atmosphere dragging stress of dislocation was calculated in optional dislocation velocity of STS310J1TB and STS310S at $650^{\circ}C$, $675^{\circ}C$ and $700^{\circ}C$. As a result of the numerical calculation, the solute atmosphere dragging stress of STS310J1TB was about 50 times larger than that of STS310S. When the temperature became high, the maximum value of solute atmosphere dragging stress was small and the velocity of moving dislocation was fast. From the relationship between the dislocation rate and the solute atmosphere dragging stress, the relation of both was proportional and the inclination is about 1 in the level with low velocity of moving dislocation. From above results, the mechanism of dislocation movement in STS310J1TB was the solute atmosphere dragging stress. The solute atmosphere dragging stress, which was calculated from the numerical calculation was close to the effect stress in stress relaxation tests.