• 약학회지
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• 제26권4호
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• pp.231-237
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• 1982

The transformation kinetics between polymorphs of sulpiride and the effect of additives on the transformation kinetics were studied. The results could be summarized as follows. 1. Transformation kinetics of the polymorph form I to form II in water suspenion was first order type and transformation rate constant at $25^{\circ}C$ is $2.61{\times}10^{-2}min^{-1}$, the half life of form I was about 27 minutes and the activation energy for transformation was 21.35 Kcal/mole. 2. Glycerine and coloring agents increased the rate of transformation., In the case of polysorbate 80, the rate constant increased in proportion to the concentration of polyserbate 80. Simple syrup showed no effect 3n transformation kinetics.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.456-459
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• 2005

Continuous cooling transformation behaviors were studied fur low carbon HSLA steels containing three different level $(1\~3\;wt\%)$ of Ni addition. Thermo-mechanical processing (TMP) simulations to construct continuous cooling (CCT) diagram were conducted by using Gleeble system. As cooling rate increased, pearlite, granular bainite, acicular ferrite, bainitic ferrite and lath martensite were transformed from deformed austenite. Fully bainitic microstructure were developed at all cooling rate condition in high Ni containing steel due to hardenability increasing effects of Ni. Ni also influenced the transformation kinetics. At the slowest cooling rate of $0.3^{\circ}C/s$, transformation delayed with decreasing Ni contents because of the diffusion of substitutional alloy elements. However, cooling rate slightly increased to $1^{\circ}C/s$, transformation kinetics accelerated with decreasing Ni contents because nucleation of bainite was sluggish due to hardening of residual austenite.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2116-2124
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• 2015

To understand the effects of physicochemical factors on nitrite transformation by microalgae, a lipid-rich Chlorella with high nitrite tolerance was cultured with 8 mmol/l sodium nitrite as sole nitrogen source under different conditions. The results showed that nitrite transformation was mainly dependent on the metabolic activities of algal cells rather than oxidation of nitrite by dissolved oxygen. Light intensity, temperature, pH, NaHCO₃ concentrations, and initial cell densities had significant effects on the rate of nitrite transformation. Single-factor experiments revealed that the optimum conditions for nitrite transformation were light intensity: 300 μmol/m²/s; temperature: 30℃ pH: 7-8; NaHCO₃ concentration: 2.0 g/l; and initial cell density: 0.15 g/l; and the highest nitrite transformation rate of 1.36 mmol/l/d was achieved. There was a positive correlation between nitrite transformation rate and the growth of Chlorella. The relationship between nitrite transformation rate (mg/l/d) and biomass productivity (g/l/d) could be described by the regression equation y = 61.3x (R² = 0.9665), meaning that 61.3 mg N element was assimilated by 1.0 g dry biomass on average, which indicated that the nitrite transformation is a process of consuming nitrite as nitrogen source by Chlorella. The results demonstrated that the Chlorella suspension was able to assimilate nitrite efficiently, which implied the feasibility of using flue gas for mass production of Chlorella without preliminary removal of NO_X.

• 열처리공학회지
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• 제30권6호
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• pp.251-257
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• 2017

The effect of annealing temperature on the martensitic transformation behavior, tensile deformation chracteristics and shape recovery etc., has been studied in TiNi based shape memory ribbon fabricated by coldrolling of wire. TiNi based shape memory wire (${\phi}=500{\mu}m$) of which structure is intermetallic compound could be cold-rolled without process annealing up to the reduction rate in thickness of 50%, but a few cracks appear in cold-rolled ribbon in the reduction rate in thickness of 65%. The $B2{\rightarrow}R{\rightarrow}B19^{\prime}$ martensitic transformation or $B2{\rightarrow}B19^{\prime}$ martensitic transformation occurs in annealing conditions dissipating lattice defects introduced by coldrolling. However, in case of higher reduction rate or lower annealing temperature, martensitic transformation in cold-rolled and then annealed ribbons does not occur. The maximum shape recovery rate of cold-rolled ribbons with the reduction rate of 35 and 65% could be achieved at annealing temperatures of 250 and $350^{\circ}C$, respectively. The shape recovery rate seems to be related to the stress level of plateau region on stress-strain curve.

• Journal of Advanced Marine Engineering and Technology
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• 제18권3호
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• pp.10-16
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• 1994

This study aimed at measuring the latent heat of phase transformation of S45C carbon steel in quenching and at conducting the analytical researches into the calculation of cooling curves including the latent heat. The temperature of phase transformation of steel and its latent heat are dependant upon the cooling rates at the temperature of A1 phase transformation point. The effect of the latent heat of phase transformation is especially manifest at the cooling curve of center of specimens. The higher the cooling rates became, the lower fell the temperature region of phase transformation. In the figures of cooling rates, the phenomena of cooling rate dropping into zero was caused by the latent heat of phase transformation.

• Journal of Welding and Joining
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• 제28권3호
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• pp.104-113
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• 2010

In this study, to predict the microstructure in weld HAZ of low alloyed steel, prediction model for the phase transformation considering the influence of prior austenite grain size and cooling rate was developed. For this study, six low alloyed steels were designed and the effect of alloying elements was also investigated. In order to develop the prediction model for ferrite transformation, isothermal ferrite transformation behaviors were analyzed by dilatometer system and 'Avrami equation' which was modified to consider the effect of prior austenite grain size. After that, model for ferrite phase transformation during continuous cooling was proposed based on the isothermal ferrite transformation model through applying the 'Additivity rule'. Also, start temperatures of ferrite transformation were predicted by $A_{r3}$ considering the cooling rate. CCT diagram was calculated through this model, these results were in good agreement with the experimental results. After ferrite transformation, bainite transformation was predicted using Esaka model which corresponded most closely to the experimental results among various models. The start temperatures of bainite transformation were determined using K. J. Lee model. Phase fraction of martensite was obtained according to phase fractions of ferrite and bainite.

• Journal of Plant Biotechnology
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• 제42권2호
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• pp.77-82
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• 2015

We found that a long period of in vitro culture is a critical factor on the low transformation rate for a specific potato genotype, Solanum tuberosum L. var. Atlantic when phosphinothricin (PPT) was added to select putative transformants in a solid media. The fresh explants of the newly produced plants from a micro-tuber was able to increase the transformation rate significantly while the old explants prepared from a plant maintained for longer than 6 months in vitro by sub-culturing every 3 ~ 4 weeks resulted in a very low transformation frequency. However, Jowon cultivar was not so much influenced by the period of in vitro culture with high transformation rate (higher than 10.0%). Further research need to be explored for the reason why a particular potato genotype, Atlantic is more vulnerable than the Jowon cultivar during the regeneration stage resulting in the low transformation frequency.

• 응용통계연구
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• 제34권1호
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• pp.75-98
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• 2021

본 논문은 전국과 시도별 출산율의 관계를 규명하는 세 가지 통계적 모형을 비교한다. 세 모형은 10년간 평균 연령별 누적출산율의 Gompit변환 자료를 대입한 회귀모형, 연령별 출산율 자료 변환 없이 원자료를 적용한 회귀모형, 그리고 확률과정 관점에서 불안정한 연령별 출산율 시계열을 적합할 경우 고려할 수 있는 공적분 모형이다. 본 논문은 전국과 지역간 비정상성 출산율의 관계를 도출하고자 할 때 다음을 제안한다. 전국과 지역 출산율의 공적분 관계식를 선행적으로 도출한다. 더 나아가 이 관계가 유의하지 않으면 변환 없는 원자료를 활용한 회귀모형 접근으로 전국과 시도별 출산율 관계를 살펴보는 것을 제안한다. 또한 Gompit 변환 자료를 대입한 회귀모형 방법은 출산율이 다른 방식과 비교해 과대추정되는 결과가 도출되었다. 끝으로 서울, 부산, 대구, 인천, 광주, 대전, 경기는 2025-2030년까지 타 지역과 다르게 합계출산율이 1.0명 이하로 예측되므로 시급하고 효율성 있는 출산율 제고정책이 필요하다고 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6005-6008
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• 2014

Aim: To compare recurrence rates of large loop excision of the transformation zone (LLETZ) with those of contour-loop excision of the transformation zone (C-LETZ) in the management of cervical intraepithelial neoplasia (CIN). Materials and Methods: The medical records of 177 patients treated consecutively by LLETZ and C-LETZ for CIN at Rajavithi Hospital between 2006 and 2009 were retrospectively reviewed. Results: Of the 87 women in the C-LETZ group, 2 cases (2.30%) had recurrence compared with 13 cases (14.4%) of the 90 women in the LLETZ group, the higher recurrence rate in the latter being statistically significant (p<0.05). Median times of follow up in the C-LETZ and LLETZ groups were 12 months and 14 months respectively (p>0.05). The C-LETZ group showed less intraoperative bleeding compared to the LLETZ group, but the rate of achievement of single specimens and positive margins were similar in the two groups. Conclusions: The present study demonstrated the superiority of C-LETZ over LLETZ in terms of efficacy; C-LLETZ is associated with a lower recurrence rate and also carries a smaller risk of intraoperative bleeding than LLETZ. The rotating technique still has a potential role in treating precancerous lesions of the cervix.

• The Journal of Asian Finance, Economics and Business
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• 제8권10호
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• pp.259-267
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• 2021

Both structural transformation and education are the predominant subjects in the literature of development economics. This study examines the relationship between education before the tertiary level and the structural transformation of provinces by using Vietnam as a case study. In this study, education before the tertiary level would be disaggregated into three groups: primary, lower secondary, and upper secondary, then analyzed simultaneously on three-panel data models. Research data is taken from the statistical yearbook of provinces in Vietnam for 2015-2018. Research results show that education before the tertiary level plays a vital role in structural transformation. The enrolment rate of various education levels has a different influence on economic structure, and the lower secondary level has more significant effects than the upper secondary level. This reflects that participating in lower secondary is a fundamental requirement for taking some jobs in the non-agriculture sector, while upper secondary helps to upgrade the learner's abilities to respond to higher requirement jobs. The high rate of repeaters in upper secondary education will slow down the structural shift towards non-agriculture, and changing the traditional attitude about repeaters plays an essential role in improving this rate.