• Textile Coloration and Finishing
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• v.19 no.3
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• pp.18-25
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• 2007

The fixing behaviors of anthraquinone disperse dyes containing dimethylamino substituent, such as C. I. Disperse Violet 26(D.V.26) and C. I. Disperse Blue 14(D.V.14), or containing diamino substituent, such as C. I. Disperse Blue 73(D.B.73), and monochlorotriazinyl azo reactive dyes, such as C. I. Reactive Orange 13(R.O.13), C. I. Reactive Red 3(R.R.3). C. I. Reactive Yellow 2(R.Y.2) on polyester/cotton blend(P/C) fabrics were examined for the one-step printing of P/C fabrics. The high temperature steaming of $175^{\circ}C$ is the most satisfactory fixing method for P/C one-step printing with above disperse and reactive dyes among the four different fixing methods: $175^{\circ}C$ steaming, $102^{\circ}C$ steaming${\rightarrow}175^{\circ}C$ steaming, $190^{\circ}C$ thermosol, $102^{\circ}C$ steaming${\rightarrow}190^{\circ}C$ thermosol. $190^{\circ}C$ thermosol is unfit to fix R.R.3 and R.Y.2 whose heat stability is poor. It was found that D.V.26 and D.B.14 containing dimethylamino substituent are unstable for heat and alkali, but D.B.73 is stable for them to print P/C blend fabrics with R.O.13 which is also stable for heat. Therefore we found that D.B.73, R.O.13 and a pair of D.B.73 and R.O.13 were very suitable for one-step printing of P/C blend fabrics.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.737-743
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• 1995

Two step RTD(Rapid Thermal Diffussion) of P into silicon wafer using tungsten halogen lamp was used to fabricated very shallow n$^{+}$p junction. 1st RTD was performed in the temperature range of 800.deg. C for 60 see and the heating rate was in the 50.deg. C/sec. Phosphrous solid source was transfered on the silicon surface. 2nd RTD process was performed in the temperature range 1050.deg. C, 10sec. Using 2 step RTD we can obtain a shallow junction 0.13.mu.m in depth. After RTD, the Ti-silicide process was performed by the two step RTA(Rapid Thermal Annealing) to reduced the electric resistance and to improve the n$^{+}$p junction diode. The titanium thickness was 300.angs.. The condition of lst RTA process was 600.deg. C of 30sec and that of 2nd RTA process was varied in the range 700.deg. C, 750.deg. C, 800.deg. C for 10sec-60sec. After 2 step RTA, sheet resistance was 46.ohm../[]. Ti-silicide n+p junction diode was fabricated and I-V characteristics were measured.red.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.367-370
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• 2007

Numerous sets of simulation were conducted in order to find out the optimum operational conditions of the existing BNR process using GPS-X program. The model of ASM3 and modified Bio-P module were applied for simulations. From the result of this study, effluent quality was closely related with the step feeding rate and influent C/N ratio. The effluent TN concentration seemed to be significantly affected by step feeding rate at the low C/N condition. But at the high C/N condition, the effluent concentration of TP rather than that of TN was affected by the control of step feeding rate.

• Clinical and Experimental Reproductive Medicine
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• v.19 no.2
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• pp.143-152
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• 1992

The present experiments were focussed to modify a short slow-cooling protocol used for freezing of early stage embryo(Testart et al., 1986) and also to apply the modified method for the cryopreservation of hamster oocytes with Zona or without. The protocol was modified by changing the 4-step equilibration into 1-step and the 1-step thawing into 2-step. The oocytes were added in 1.5M PROH and 0.1M Sucrose, seeded at $-7^{\circ}C$, slow cooled($0.3^{\circ}C$/min) to $-30^{\circ}C$ before plunging to $-196^{\circ}C$. The oocytes were thawed at $23-25^{\circ}C$ air(20sec/150sec) and/or 33-35 water(10sec). The survival of the frozen-thawed oocytes was determined by morphologic criteria and their fertilizing ability was also estimated by Sperm Penetration Assay(SPA) system(Chang et al, 1990) using fertile men semen sample. One-step equilibration showed slightly higher survival rate(83.9% vs. 71.0%) and fertilization rate(83.9% vs. 71.0%) compared with four-step(p>0.05). And two-step thawing(air & water exposing) of oocytes frozen after 1-step equilibration showed significantly higher survival rate(96.3%) than one-step thawing at air(85.2%) or water(65.0%) only(p<0.05). Therefore, by the modified method(l-step equilibration & 2-step thawing), Zona-intact(ZI) and Zona-free(ZF) oocytes were frozen and thawed. ZI-oocytes showed significantly higher survival rate(95.4%, 308/323 vs. 67.6%, 240/355) than ZF-oocytes(P<0.01). But the survival of ZF-oocytes was as high as ZI-oocytes in fourteen of twenty-four replicates. ZI-oocytes was also significantly higher fertilization rate($92.4{\pm}8.9%$ vs. $63.7{\pm}18.5%$) and higher mean number of penetrated sperm($6.2{\pm}4.2$ vs. $3.9{\\pm}3.3$) than ZF-oocytes, but not higher than control(fresh oocytes;$99.3{\pm}2.4%$, $8.4{\pm}4.2$)(P<0.001). Conclusively, this modified method will contribute to freeze effectively the hamster oocytes for simplifing of the logical consideration of performing SPA and also to freeze the human and other animal oocytes.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.768-779
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• 1995

This study was performed to investigate the effect of root canal shaping techniques on the change of the shape of prepared root canal. 40 mesiobuccal canals of recently extracted mandibular 1st and 2nd molars were divided into 4 groups and shaped by step-down/balanced force technique, step-down/step-back technique, step-back technique and conventional technique respectively. The change of the shape of root canal was traced by superimposing the radiographs obtained before and after shaping of each root canal. The results were as follows. 1. By the experimented techniques except conventional technique, the root canals were more shaped in convex side of apical area and in concave side of most curved and coronal area than in the other sides(P<0.05). By conventional technique, the root canals were more shaped in convex side than in convave side from apex to orifice(P<0.05). 2. By step-down/balanced force technique, the cancave sides at C and D points of proximal view and C point of clinical view were more shaped than the convex side(P<0.05). Through the entire canal, the concave side was more shaped than the convex side in proximal view(P<0.01). But there was no statistical difference between both sides in clinical view. 3. By step-down/step-back technique, the change of root canal shape was not statistically different in concave and convex sides at each point of both views(P>0.05). And through the entire canal in proximal view, there was no statistical difference in shaping percentage between both sides. But through the entire canal in clinical view, the concave side was more shaped than the convex side(P<0.1). 4. By step-back technique, the convex side at B point of clinical more shaped than the other sides(P<0.05). Through the entire canal in proximal and clinical views, there was no statistical difference in shaping percentage between both sides. 5. Comparing the total shaping percentage among techniques, that in conventional technique was the greatest numerically, and followed by the percentages in step-down/step-back, step-down/balanced force and step-back technique. But, in proximal view, shaping percentages were not statistically different among techniques(P>0.05, ANOVA test). In clinical view, shaping percentages in step-back and conventional techniques were statistically different(P<0.01, ANOVA test). * Proximal view: radiograph taken in mesiodistal direction. * Clincal view: radiograph taken in faciolingual direction. A point : 1mm point from radiographic apex B point : center point between A and C points C point : most curved point of root canal D point : center point between C point and canal oriffice.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.59-64
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• 2006

This study was conducted to establish a convenient freezing method of boar semen. Boar semen was cooled until $5^{\circ}C$ for 3 hrs using cell freezer and loaded into straws. Semen straws were frozen in different steps in strofoam box filled with $LN_2$. Highest sperm viability (54.0%) was obtained by 1-step freezing(holding at 10 cm height from the surface of $LN_2$ for 10 min). Sperm viability increased by holding at $-102^{\circ}C$ for 10min (74.0%, P<0.05). In thawing regime, sperm viability was significantly higher in $37^{\circ}C$ group than in $52^{\circ}C$ group. The sperm characteristics did not differ between 1-step and 3-step. After IVF using frozen-thawed boar semen, developmental rate of embryos to the morula+blastocyst stage was in 1-step freezing group than that of 3-step freezing group (27.5 vs 14.7%, P<0.05). The result shows that the 1-step freezing with holding at $-102^{\circ}C$ for 10min before plunging into $LN_2$ is a convenient and easy freezing method for boar semen.

• Analytical Science and Technology
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• v.6 no.1
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• pp.83-92
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• 1993

The electrochemical behaviors of lanthanide ion(La and Nd) and lanthanide complexes with 2, 2, 6, 6-tetramethyl-3, 5-heptanedione(THD), sym-hydroxydibenzo-16-crown-5(HD16C5) and sym-dibenzo-16-crown-5-oxyacetic acid(D16C5A) ligands in acton solution have been investigated by the use of cyclic voltammetry and direct current polarography. The peak potential and peak current, their dependency on the concentration, temperature, the reversibility of the eleotrode reactions are described. The reduction of the lanthanide ions and complexes in 0.05 M TEAP proceeded one-electron step in first step and one two-electron step in second step. These reduction step was irreversible and the reduction current was diffusion controlled. Macrovcyclic crown ethers, sym-hydroxydibenzo-16-crown-5(HD16C5) and sym-dibenzo-16-crown-5-oxyacetic acid(D16C5A), were prepared from 1, 5-bis-(2-hydroxyphenoxy)-3-oxapentane with epichlorohydrin. The voltammetric behaviors of Ln(III)-HD16C5 and Ln-D16C5A complexes in aceton solution have been investigated by the voltammetric method. The composition and stability constants of lanthanide complexes were determined.

• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.81-87
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• 2024

Purpose: CA 19-9 is the most widely used tumor marker for the diagnosis of digestive system tumor, especially pancreatic and biliary tract cancer. This study was conducted to improve the result value near reference range by comparing the reagents of CA 19-9 one step method and two step method. In addition, it was intended to establish a standard for selecting reagents. Material and Methods: 120 patients who visited the National Cancer Center in 2023 were selected as subjects for this study. The reagents used in the study were CA 19-9 IRMA kits (Shinjin, Korea) and three types of reagents were compared. Two step method reagent that is currently being used (A), one step method reagent (B) and two step method reagent improved by request (C) were compared and regression analysis was performed on their data. And we also performed recovery test, linearity test and hook effect test for each reagent. Result: There were 46 cases of reagent B in which the concentration value was lower than the result measured in reagent A that was previously used, and 77 cases of reagent C. As a result of regression analysis of reagents A, B, and C, the coefficients of determination of reagents A and B, reagents A and C, and reagents B and C were 0.653, 0.577, and 0.875. In the recovery rate test and the linearity test, the results of all reagents were good, and in the hook effect test, reagent B showed a hook effect at a low value. Conclusion: The improved reagent C appears to have been improved based on the concentration value of reagent B, which the manufacturer judged to be more stable at low concentrations. The hook effect in reagent B can be a fatal reason for disqualification when selecting reagents in general patient samples which high-concentration samples appear frequently. The first improved reagent C will be able to be used once it is confirmed that it has more stability for various concentration values.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.2
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• pp.57-60
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• 2019

The impact of two-step treatment on the mechanical properties of the 6061 Al alloy was investigated by testing the hardness and electrical conductance values. After two-step aging treatment, the hardness and electrical conductivity of the alloy was increased, and if the first aging treatment temperature was lower than the secondary aging treatment temperature, both the hardness and the electrical conductivity were not increased. The higher the temperature of the first aging treatment, the higher the hardness. The temperature of the first aging treatment is $175^{\circ}C$, $150^{\circ}C$, $120^{\circ}C$, and the second is $175^{\circ}C$ and $120^{\circ}C$.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.248-262
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• 1991

Simulation model was developed to analyze drying process for tray type red pepper dryer and validated by experiments. This model could predict satisfactorily temperatures and moisture contents of red pepper and temperatures of drying air during drying. Optimize algorithm was developed to search control valiables (drying air temperature, air recycle ratio and air flow rate) of red pepper dryer based on a criterion of minimizing energy consumption under the constraint conditions that statisfied carotenoid retension of at least 210mg per 100g dry matter, the moisture content of bottom layer of 15% (d.b) and drying time of less than 35 hours. Step changes in drying air temperature and air recycle ratio were considered in the optimization. In single step in control variables, the difference of the moisture content between top layer and bottom layer was great and more fan power was required. As the drying trays were exchanged when the moisture content of bottom layer reached to 100% (d.b), fifty percent of energy was saved and the difference of moisture content was little. In double step changes in control variables, optimal conditions were found by changing the step when the moisture content of bottom layer reached to 100% (d.b) (about 19.8 hours from starting drying). Optimum air flow rate was $18.1cmm/m^2$. Optimum drying air temperature and air recycle ratio in the first step was $55.8^{\circ}C$ and 0.80, and in the second step $65.6^{\circ}C$ and 0.88, respectively. In triple step changes in control variables, the optimal conditions were found by changing the steps when the moisture content of bottom layer reached to 250% (d.b) and 150% (d.b). Optimal air temperatures were $66.2^{\circ}C$, $58.4^{\circ}C$ and $66.9^{\circ}C$, and optimal air recycle ratios were 0.778, 0.785, 0.862 at each step, respectively. Optimal air flow rate was $18.9cmm/m^2$. The best operating mode was triple step mode considering energy consumption, drying time, fan power, and quality of dried red pepper. When the triple step mode was used to dry the red pepper, the energy consumption was about 16.5%~57.2% less than that of the single step mode and the drying time was 6.6 hours shorter than that of the double step mode.