• Title/Summary/Keyword: different concentration

Search Result 10,040, Processing Time 0.036 seconds

Molecular dynamics study of Al solute-dislocation interactions in Mg alloys

  • Shen, Luming
    • Interaction and multiscale mechanics
    • /
    • v.6 no.2
    • /
    • pp.127-136
    • /
    • 2013
  • In this study, atomistic simulations are performed to study the effect of Al solute on the behaviour of edge dislocation in Mg alloys. After the dissociation of an Mg basal edge dislocation into two Shockley partials using molecular mechanics, the interaction between the dislocation and Al solute at different temperatures is studied using molecular dynamics. It appears from the simulations that the critical shear stress increases with the Al solute concentration. Comparing with the solute effect at T = 0 K, however, the critical shear stress at a finite temperature is lower since the kinetic energy of the atoms can help the dislocation conquer the energy barriers created by the Al atoms. The velocity of the edge dislocation decreases as the Al concentration increases when the external shear stress is relatively small regardless of temperature. The Al concentration effect on the dislocation velocity is not significant at very high shear stress level when the solute concentration is below 4.0 at%. Drag coefficient B increases with the Al concentration when the stress to temperature ratio is below 0.3 MPa/K, although the effect is more significant at low temperatures.

Cell Viability and Fatty Acids Composition of Zymomonas mobilis grown at different Concentrations of Ethanol (Zymomonas mobilis 균체의 지방산 분포와 균의 생존성에 미치는 ethanol 농도의 영향)

  • 권석흠;이계준
    • Korean Journal of Microbiology
    • /
    • v.25 no.1
    • /
    • pp.80-85
    • /
    • 1987
  • The aim of the present studies was to analyze the physiological background of ethanol inhibition in Zumomonas mobilis. The experiments were carried out with a number of continuous culture to give steady state concentration of ethanol. The domposition of fatty acids in the cells obtained from various conditions was analyzed and cell viability was also estimated. As results, it was found that vaccenic acid was the mafor fatty acid in the cell of Z. mobilis and the concentration was changed apparently to increase as increasing the concentration of ethanol produced from substrate utilization. Finally it was observed also that cell viability was decreased remarkably at the elevated ethanol concentration. Those changes might play important roles in the ethanol fermentation to give more complex phenomena observed at high concentration of ethanol.

  • PDF

Effect of Digestibility of Soybean Peptides on the Concentration of Serum Cholesterol in Rats (대두 펩타이드와 소화율이 흰쥐의 혈청 콜레스테롤 농도에 미치는 영향)

  • 한응수
    • Journal of Nutrition and Health
    • /
    • v.26 no.5
    • /
    • pp.585-592
    • /
    • 1993
  • In order to investigate the hypocholesteremic effect of soybean perptides, soybean protein(ISP), casein(CNP), their peptic hydrolyzates fractionated by acid precipitation at different pH's(SHT, SH8, SH6, SH4, CHT, CH5, CH4) and amino acid mixtures of the same composition as the proteins(SAA, CAA) were fed to rats and the concentration of serum cholesterol was measured. Then in vitro digestibility and molecular weight distribution of the peptides by pepticpancreatic hydrolysis was measured by FPLC. The lower the in vitro digestibility of peptides is, the lower the concentration of serum cholesterol becomes(r=0.986) and the higher the ratio of macropeptides is, the lower the concentration of serum cholesterol becomes(r=-0.932) in rats. These results suggest that the in vitro digestibility of peptides has close relationship to the concentration of serum cholesterol in rats and non-digestible meacropeptides or polypeptides especially more than 1 kDa, formed through digestion in gut, may lower the serum cholesterol in rats.

  • PDF

The Degumming and Sericin Recovery of the Silk fabric Using the Electrolytic Water(II) (전해수를 이용한 견섬유 정련 및 세리신 회수(II)-분리막에 의한 세리신 농축을 중심으로-)

  • 배기서;이태상;노덕길;홍영기
    • Textile Coloration and Finishing
    • /
    • v.16 no.4
    • /
    • pp.10-18
    • /
    • 2004
  • In this work, Aqueous sericin solution was prepared by degumming process with electrolytic reduction water. Then, the microfiltration and ultrafiltration systems were applied to the concentration of aqueous sericin solution. The objective of this study was to select the optimum operating condition among the different pressure. The permeate flux and rejection ratio were observed with time, pressure, flow rate and concentration. and, the wastewater and permeated water quality values such as pH, BOD, COD, and NH levels were measured. In order to see the influence of electrolytic reduction water, the flux of pure water and electrolytic reduction water by PVDF22(MF) and PS100(UF) membrane was measured. In microfiltration system, the relative flux reduction decreased rapidly to 0.02 in the 30min, as the concentration polarization and gel layer formation were increased. and then the sericin concentration rejection ratio was 40%. In ultrafiltration system, the permeate flux decreased with time and concentration, and increased with the operating pressure and flow rate. Optimal condition in PS100 membrane system for sericin concentration was operating pressure 1.464kgf/$cm^24, operating flow rate $7\ell/min at\; 40^{\circ}C$. At that time, sericin concentration rejection ratio was 83% respectably. The sericin solution was concentrated from 0.1wt% solution to 0.2 wt % solution during about 2 hrs by the UF filteration membrane system.

Development of accuracy enhancement system for boron meters using multisensitive detector for reactor safety

  • Sung, Si Hyeong;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
    • /
    • v.52 no.3
    • /
    • pp.538-543
    • /
    • 2020
  • Boric acid is used as a coolant for pressurized-water reactors, and the degree of burnup is controlled by the concentration of boric acid. Therefore, accurate measurement of the concentration of boric acid is an important factor in reactor safety. An improved system was proposed for the accurate determination of boron concentration. A new boron-concentration measurement technique, called multisensitive detection, was developed to improve the measurement accuracy of boron meters. In previous studies, laboratory-scale experiments were performed based on different sensitivity detectors, confirming a 65% better accuracy than conventional single-detector boron meters. Based on these experimental results, an experimental system simulating the coolant-circulation environment in the reactor was constructed; accuracy analysis of the boron meter with a multisensitivity detector was performed at the actual coolant pressure and temperature. In this study, the boron concentration conversion equation was derived from the calibration test, and the accuracy of the boron concentration conversion equation was examined through a repeatability test. Through the experiment, it was confirmed that the accuracy was up to 87.5% higher than the conventional single-detector boron meter.

Investigation into the Distribution of Total, Free, Peptide-bound, Protein-bound, Soluble-and Insoluble-Collagen Hydroxyproline in Various Bovine Tissues

  • Siddiqi, Nikhat J.;Alhomida, Abdullah S.
    • BMB Reports
    • /
    • v.36 no.2
    • /
    • pp.154-158
    • /
    • 2003
  • Collagen is a family of proteins which consists of several genetically distinct molecular species and is intimately involved in tissue organization, function, differentiation and development. The purpose of this study was to investigate the concentration of different hydroxyproline (Hyp) fractions viz., total, free, peptide-bound, protein-bound, soluble- and insoluble-collagen hydroxyproline (Hyp) in various bovine tissues. Results showed that liver had the highest concentration of free Hyp followed by kidney, brain, spleen, lungs, muscle and heart. Liver also had the highest concentration of peptide-bound collagen Hyp followed by kidney, heart, spleen, lungs, brain and muscle. The concentration of protein-bound collagen Hyp was highest in the liver, followed by kidney, spleen, lungs, muscle, brain and heart. Total Hyp was highest in the liver, followed by kidney, spleen, brain, heart, muscle and lungs. Liver also had significantly high concentration of collagen as compared to other tissues examined (P<0.001). Spleen had the significantly higher concentration of soluble-collagen Hyp when compared to other tissues (P<0.001). This was followed by heart, muscle, lungs, brain, kidney and liver. Heart had the highest concentration of insoluble-collagen Hyp followed by lungs, kidney, liver, muscle, spleen and brain. The variation among the insoluble-collagen Hyp concentration of heart and muscle, spleen and brain was significant (P<0.001). We speculate that these differences could be due to the variation in turn over of rate of collagen metabolism in this species.

Comparison of particle size distribution and particle number concentration measured by APS 3321 and Dust Monitor 1.108 (APS 3321과 Dust Monitor 1.108을 이용한 입자 크기분포 및 수농도 측정결과 비교)

  • Lim, Kyoung-Soo;Park, Hyun-Seol
    • Particle and aerosol research
    • /
    • v.5 no.2
    • /
    • pp.63-70
    • /
    • 2009
  • The size distribution and number concentration of atmospheric aerosol were measured and compared using APS 3321 and Dust Monitor 1.108. The particle size distribution and number concentration measured by two devices were also compared at a particle generation system of standard PSL and fly ash. The number concentration of atmospheric aerosol measured by APS was higher than that by Dust Monitor in particle size range of less than $3.0{\mu}m$, but there was good accordance between them in particle size range of over $3.0{\mu}m$. In the particle generation system of PSL and fly ash, different measurement results were shown because the particle concentration was higher than that of atmospheric aerosol. The number concentration measured by Dust Monitor was higher than that by APS in most particle size ranges. However, the peak concentration of PSL particles measured by Dust Monitor was lower than that by APS. The difference of the collection efficiency in a scrubber by APS and Dust Monitor measurement was less than 10%, but in the particle size of $1.5{\mu}m$, it was over 20%.

  • PDF

창원시 대산면 취수 부지의 지하수와 낙동강의 수리화학적 특성 비교

  • Ham Se-Yeong;Jeong Jae-Yeol;Lee Jeong-Hwan;Kim Hyeong-Su;Ryu Sang-Hun;Kim Tae-Won;Kim Mun-Su
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2006.04a
    • /
    • pp.307-311
    • /
    • 2006
  • Chemical analyses were conducted for Nakdong River water and riverbank filtrate in Daesan-Myeon area, Changwon City in 2005. Chemical components show different trends in wet season (June, July, August and September) and dry season (the other months). The patterns of chemical variation are classified into four types. Chemical components belonging Type I, as Na and $HCO_3$, show decrease in concentration during wet season and increase in concentration during dry season for both Nakdong River water and the riverbank filtrate. Chemical components belonging Type II, as Mg and $SO_4$, show decrease in concentration during wet season and increase in concentration during dry season for Nakdong River water while show the opposite trend for the riverbank filtrate. Chemical components belonging Type III, as Cl and $NO_3$, show increase in concentration from the start of wet season and high concentration during dry season for both Nakdong River water and the riverbank filtrate. Chemical components belonging Type IV, as Fe, show increase in concentration during wet season and decrease in concentration during dry season for both Nakdong River water and the riverbank filtrate.

  • PDF

A Study on Properties of Ga-doped ZnO Thin Films for Annealing Temperature Change by RF Sputtering Method (RF Sputtering으로 증착한 어닐링 온도 변화에 따른 Ga-doped ZnO 박막 특성 연구)

  • Han, Seung Ik;Kim, Hong Bae
    • Journal of the Semiconductor & Display Technology
    • /
    • v.15 no.2
    • /
    • pp.11-15
    • /
    • 2016
  • This paper, Ga-doped ZnO (GZO) thin films which were deposited on Corning glass substrate using an magnetron sputtering deposition technology and then the post deposition annealing process was conducted for 30 minutes at different temperature of 100, 200, 300, and $400^{\circ}C$, respectively. So as to investigate the properties for the relevant the Concentration and Oxygen Vacancy with Annealing temperature of Ga-doped ZnO thin films by RF Sputtering method. The Carrier concentration is enhanced as annealing temperature decreases, and also the oxygen vacancy concentration is enhanced as annealing temperature decreased. Oxygen vacancy will decrease along with Carrier concentration. This change in Carrier concentration is related to changes in oxygen vacancy concentration. The figure of merit obtained in this study means that Ga-doped ZnO films which annealed at $400^{\circ}C$ have the lowest Carrier concentration and Oxygen vacancy, which have the highest optoelectrical performance that it could be used as a transparent electrode.

Effect of Calcium Inhibitors on Mouse Oocyte Maturation ($Ca^{2+}$ Inhibitor가 생쥐난자 성숙에 미치는 영향)

  • Chung, Hye-Won;Yoo, Han-Ki;Bae, In-Ha
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.19 no.1
    • /
    • pp.15-29
    • /
    • 1992
  • In the present study, it was aimed to find the role of calcium on the maturation of mouse follicular oocytes as well as for the role of calcium inhibitors, $Ni^{2+}$ and $La^{3+}$. Mouse follicular oocytes were cultivated in different media at $37^{\circ}C$, in 100% humidified $CO_2$ incubator for 3 and 17 hrs. The results were as follows; 1. There was no differences in GVBD between the control and experimental groups during the 3 hr culture. 2. Mouse oocytes were matured to higher rate in MHBS rather than HTF for 17 hr culture. 3. Maturation rate was significantly lower in $Ca^{2+}$-free and $Ca^{2+}$ 0.4 mM which were tested, compared to other calcium concentration used in the present study. 4. Calcium inhibitor, $Ni^{2+}$, it showed highest degeneration rate at all calcium concentrations and additionally in $Ni^{2+}$ $100{\mu}M$ treated group next. Maturation rate was significantly decrease as the $Ca^{2+}$ inhibitor concentration increased. 5. In all Lanthanum treated groups of calcium-free, degeneration were significantly high treated groups at 0.4 mM $Ca^{2+}$ concentrations degeneration rates of all group were significantly lower than that of the control but maturation rates were not significantly different in any group. In lanthanum $100{\mu}M$ treated group at 0.4 mM and 0.8 mM calcium concentration, its maturation rate was significantly higher than that of the control. Maturation rates of all groups of lanthanum treated at 1.71 mM calcium concentration were not significantly different among groups. 6. In the calcium treated group (0.4mM-1.7 mM), the presence of phosphate does not seem to be needed for oocyte maturation. However, the presence of phosphate at $Ca^{2+}$ 0.8 mM only seems to stimulated maturation.

  • PDF