• Journal of the Korean Chemical Society
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• v.4 no.1
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• pp.70-77
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• 1957

4,5-Diphenyl Imidazolone is synthesized from Benzoin, Urea, and Acetic acid catalyser. Nowadays, it is being used as an optical bleaching agent for wool and nylon textiles. Up to now, only one process of synthesis has been known. In order to find out the best conditions governing the yield were examined under various catalysers and conditions. In this experiment, the summary of results were as follows. a. On Acetic acid catalyser. The maximum yield conditions were mol ratio (Benzoin: Urea: Acetic acid) 1 : 2 : 14, Acetic acid concentration 99.9%. Reaction temperature 115$^{\circ}$. Under reaction time of 2 hours, above yield was 96.4%. b. On Mineral acid Catalyser. In using of Sulfonic acid, the color of solution was changed dark purlish black. With other mineral acid catalysers, in spite of increasing of temperature, it was proved that Benzoin floats on the solution, so that this reaction could not be continue. c. On Phosphoric acid catalyser. It was made clear that it can not be used for this reaction. d. On Sodium hydroxide catalyser. As one of Alkali catalyser, Sodium hydroxide was examined but this was unsuitable substance for this reaction. e. On Formic acid catalysers. The maximum yield conditions were mol ratio (Benzoin: Urea: Formic acid) 1: 2: 30. Formic acid concentration 85.%. Reaction temperature 150∼110$^{\circ}$. Under reaction time of 90 minutes, the best yield was 87%. Hereby, it was proved that organic acids such as Acetic acid and Formic acid can be used. When using Acetic acid, the yield was better than Formic acid, but it takes longer reaction time than Formic acid. About the fluorescent effect, the temperature of dye-bath must not be over 904,5-Diphenyl Imidazolone is synthesized from Benzoin, Urea, and Acetic acid catalyser. Nowadays, it is being used as an optical bleaching agent for wool and nylon textiles. Up to now, only one process of synthesis has been known. In order to find out the best conditions governing the yield were examined under various catalysers and conditions. In this experiment, the summary of results were as follows. a. On Acetic acid catalyser. The maximum yield conditions were mol ratio (Benzoin: Urea: Acetic acid) 1 : 2 : 14, Acetic acid concentration 99.9%. Reaction temperature 115$^{\circ}$. Under reaction time of 2 hours, above yield was 96.4%. b. On Mineral acid Catalyser. In using of Sulfonic acid, the color of solution was changed dark purlish black. With other mineral acid catalysers, in spite of increasing of temperature, it was proved that Benzoin floats on the solution, so that this reaction could not be continue. c. On Phosphoric acid catalyser. It was made clear that it can not be used for this reaction. d. On Sodium hydroxide catalyser. As one of Alkali catalyser, Sodium hydroxide was examined but this was unsuitable substance for this reaction. e. On Formic acid catalysers. The maximum yield conditions were mol ratio (Benzoin: Urea: Formic acid) 1: 2: 30. Formic acid concentration 85.%. Reaction temperature 150∼110$^{\circ}$. Under reaction time of 90 minutes, the best yield was 87%. Hereby, it was proved that organic acids such as Acetic acid and Formic acid can be used. When using Acetic acid, the yield was better than Formic acid, but it takes longer reaction time than Formic acid. About the fluorescent effect, the temperature of dye-bath must not be over 90$^{\circ}$. and the ratio of 4,5-Diphenyl Imidazolone and water should be from 1:50000. to 1:10000. It proved that the best effect on textiles, and the best condition were dye-temperature near 704,5-Diphenyl Imidazolone is synthesized from Benzoin, Urea, and Acetic acid catalyser. Nowadays, it is being used as an optical bleaching agent for wool and nylon textiles. Up to now, only one process of synthesis has been known. In order to find out the best conditions governing the yield were examined under various catalysers and conditions. In this experiment, the summary of results were as follows. a. On Acetic acid catalyser. The maximum yield conditions were mol ratio (Benzoin: Urea: Acetic acid) 1 : 2 : 14, Acetic acid concentration 99.9%. Reaction temperature 115$^{\circ}C$. . Under reaction time of 2 hours, above yield was 96.4%. b. On Mineral acid Catalyser. In using of Sulfonic acid, the color of solution was changed dark purlish black. With other mineral acid catalysers, in spite of increasing of temperature, it was proved that Benzoin floats on the solution, so that this reaction could not be continue. c. On Phosphoric acid catalyser. It was made clear that it can not be used for this reaction. d. On Sodium hydroxide catalyser. As one of Alkali catalyser, Sodium hydroxide was examined but this was unsuitable substance for this reaction. e. On Formic acid catalysers. The maximum yield conditions were mol ratio (Benzoin: Urea: Formic acid) 1: 2: 30. Formic acid concentration 85%. Reaction temperature 150∼110$^{\circ}C$. Under reaction time of 90 minutes, the best yield was 87%. Hereby, it was proved that organic acids such as Acetic acid and Formic acid can be used. When using Acetic acid, the yield was better than Formic acid, but it takes longer reaction time than Formic acid. About the fluorescent effect, the temperature of dye-bath must not be over 90$^{\circ}C$. and the ratio of 4,5-Diphenyl Imidazolone and water should be from 1:50000. to 1:10000. It proved that the best effect on textiles, and the best condition were dye-temperature near 70$^{\circ}C$. and dye-time 15 minutes. . and dye-time 15 minutes. . and the ratio of 4,5-Diphenyl Imidazolone and water should be from 1:50000. to 1:10000. It proved that the best effect on textiles, and the best condition were dye-temperature near 70$^{\circ}C$. and dye-time 15 minutes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.306-316
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• 2015

An experiment in a controlled environment was conducted to evaluate the genotypic differences of grain yield and yield-related elements of rice under elevated air temperature. Eight rice genotypes included in three maturing group (early, medium, and medium-late maturing group) were grown with 1/5,000 a Wagner pots at four plastic houses that were controlled to the temperature regimes of ambient temperature (AT), $AT+1.5^{\circ}C$, $AT+3.0^{\circ}C$, and $AT+5.0^{\circ}C$ throughout the rice growing season in 2011. Ripened grain ratio and 1000 grain weight showed the most susceptible and tolerant responses to elevated air temperature, respectively. The grain yield reduction was attributable to the sharp decrease of ripened grain ratio. Grain yield was significantly decreased above the treatment of $AT+1.5^{\circ}C$ and $AT+3.0^{\circ}C$ in early maturing group and the others, respectively. Highly correlation to average temperature from heading to 20 days was revealed in yield (r = -0.69), ripened grain ratio (r = -82), fully-filled grain (r = -70), and 1000 grain weight (r = -0.31). The responses of yield and yield-related elements except number of spikelets and panicle to elevated air temperature were fitted to a logistic function. The parameters of logistic function for each elements except grain yield could not be applied to the other varieties. In conclusion, yield and yield-related elements responded differentially to elevated air temperature according to maturity groups and rice varieties. Ongoing global warming is expected to decrease the grain yield not only by decreasing the grain weight but also decreasing the ripened grain ratio in the future. However, the yield reduction would be mitigated by adopting and/or breeding the less sensitive varieties to high temperature.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.158-163
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• 2009

Titanium alloy sheets have excellent specific strength and corrosion resistance as well as good performance at high temperature. Recently, titanium alloys are widely employed not only aerospace parts but also bio prothesis and motorcycle. However, due to the low formability and large spring back at room temperature, titanium alloy sheets were usually formed by slow forming or hot forming with heating die and specimen. In the sheet metal forming area, FE simulation technique to optimize forming process is widely used. To achieve high accuracy FE simulation results, Identification of material properties and deformation characteristic such as yield function are very important. In this study, uniaxial tensile and biaxial tensile test of Ti-6Al-4V alloy sheet with thickness of 1.0mm were performed at elevated temperature of 873k. Biaxial tensile tests with cruciform specimen were performed until the specimen was breakdown to characterize the yield locus of Ti-6Al-4V alloy sheet. The experimental results for yield locus are compared with the theoretical predictions based on Von Mises, Hill, Logan-Hosford, and Balat's model. Among these Logan-Hosford's yield criterion well predicts the experimental results.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.571-578
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• 2014

The garlic cultivation area is moved by change of grown environment due to global warming. It is important to predict changes in cultivation area, quantity and quality of each crop. This study was carried out to estimate the yield and response of garlic growth by the rapid temperature changes in the greenhouse with thermostat control system. Seedlings of Namdo garlic were planted on September 27, 2012 and harvested on May 30, 2013. The used treatments for a rapid temperature change in March-April-May were T0 (control): $6.0-10.4-17.2^{\circ}C$, T1: $6.0-5.4(-5)-17.2^{\circ}C$, T2: $6.0-10.4-22.2(+5)^{\circ}C$ and T3: $6.0-5.4(-5)-22.2(+5)^{\circ}C$. Total dried weight per plant of garlic significantly increased by 5.0% for T2, but T1 and T3 decreased by 12.5 and 4.6%, respectively, compared to T0. Total yields of bulb within the temperature change as T2 and T0 increased significantly (p<0.05), as compared to T1. Decreasing temperature significantly (p<0.05) reduced plant height, SPAD reading, crude protein and fiber contents etc., as compared to T0 and T2. ABA contents gradually increased with time but IAA content rapidly decreased. Conclusively, growth and yield of garlic were more affected by decreased temperature than increased temperature at bulb development stage.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.569-575
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• 2017

One of the important requirements for the application of reduced-activation ferritic/martensitic (RAFM) steel is to retain proper mechanical properties under irradiation and high-temperature conditions. To simulate the yield strength and stress-strain curve of steels during high-temperature and irradiation conditions, a multiscale simulation method consisting of both microstructure and strengthening simulations was established. The simulation results of microstructure parameters were added to a superposition strengthening model, which consisted of constitutive models of different strengthening methods. Based on the simulation results, the strength contribution for different strengthening methods at both room temperature and high-temperature conditions was analyzed. The simulation results of the yield strength in irradiation and high-temperature conditions were mainly consistent with the experimental results. The optimal application field of this multiscale model was 9Cr series (7-9 wt.%Cr) RAFM steels in a condition characterized by 0.1-5 dpa (or 0 dpa) and a temperature range of $25-500^{\circ}C$.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.341-351
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• 2022

The physiological characteristics, growth, and yield of each regional rice variety ('Odaebyeo', 'Saechucheong', 'Ilmibyeo') were investigated depending on the impact of changes in temperature and CO₂ concentration. Experiments were conducted with a control group, which reflected atmospheric CO₂ concentration and temperature, and treatment groups, in which the CO₂ concentration and temperature were increased by 250 ppm and 2.0℃ from those in the control group. The results showed that the increase in CO₂ concentration and temperature reduced the growth and yield of the rice 'Odaebyeo', but did not substantially change the productivity of the 'Saechucheong' and 'Ilmibyeo'. The increase in CO₂ concentration and temperature increased stomatal conductance and rate of transpiration of the 'Odaebyeo' variety, thereby decreasing its water use efficiency (WUE). In contrast, the increase in CO₂ concentration and temperature increased the photosynthetic rate and WUE of the 'Saechucheong' and 'Ilmibyeo' varieties. The gradual change in climate is considered to directly affect growth and development of rice and diversely affect the productivity of each variety. Therefore, it is necessary to implement technological development, select regionally optimal rice varieties, develop new rice varieties, as well as conduct long-term monitoring of each rice variety for climate adaptation to counter global warming.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.137-148
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• 2007

Using a strain-controlled rheometer [Rheometrics Dynamic Analyzer (RDA II)], the steady shear flow properties of a semi-solid ointment base (vaseline) have been measured over a wide range of shear rates at temperature range of $25{\sim}60^{\circ}C$. In this article, the steady shear flow properties (shear stress, steady shear viscosity and yield stress) were reported from the experimentally obtained data and the effects of shear rate as well as temperature on these properties were discussed in detail. In addition, several inelastic-viscoplastic flow models including a yield stress parameter were employed to make a quantitative evaluation of the steady shear flow behavior, and then the applicability of these models was examined by calculating the various material parameters (yield stress, consistency index and flow behavior index). Main findings obtained from this study can be summarized as follows : (1) At temperature range lower than $40^{\circ}C$, vaseline is regarded as a viscoplastic material having a finite magnitude of yield stress and its flow behavior beyond a yield stress shows a shear-thinning (or pseudo-plastic) feature, indicating a decrease in steady shear viscosity as an increase in shear rate. At this temperature range, the flow curve of vaseline has two inflection points and the first inflection point occurring at relatively lower shear rate corresponds to a static yield stress. The static yield stress of vaseline is decreased with increasing temperature and takes place at a lower shear rate, due to a progressive breakdown of three dimensional network structure. (2) At temperature range higher than $45^{\circ}C$, vaseline becomes a viscous liquid with no yield stress and its flow character exhibits a Newtonian behavior, demonstrating a constant steady shear viscosity regardless of an increase in shear rate. With increasing temperature, vaseline begins to show a Newtonian behavior at a lower shear rate range, indicating that the microcrystalline structure is completely destroyed due to a synergic effect of high temperature and shear deformation. (3) Over a whole range of temperatures tested, the Herschel-Bulkley, Mizrahi-Berk, and Heinz-Casson models are all applicable and have an almostly equivalent ability to quantitatively describe the steady shear flow behavior of vaseline, whereas the Bingham, Casson,and Vocadlo models do not give a good ability.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.48-55
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• 2003

This study investigates the effect of temperature and electric field strength on the Bingham characteristics of Electro-Rheological(ER) fluids which change their Yield shear stress and viscosity by temperature and electric field strength. It is found that under constant temperature the Yield sheal stress and viscosity of ER fluids proportionally increase with the applied electric field strength, and under constant applied electric field strength the Yield shear stress and viscosity of ER fluids decrease with the increasing temperature. These results are considered to be applied to the fluid and pneumatic power industry.

• Plant Resources
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• v.6 no.3
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• pp.221-226
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• 2003

To improve industrial scale extraction method for extraction of icariin from Epimedium koreanum Nakai, the yields under different extracting conditions such as solvent, temperature, duration and solvent to plant material weight ratio were compared. Regarding extracting solution, highest extracts and icariin yield could be achieved when 10% EtOH was used. In case of plant material to extracting solvent ratio, no significant differences could be observed from 1/10 to 1/50, indicating 1/10 was the most efficient. Extracting temperature significantly affected extracts and icariin yields in that 9$0^{\circ}C$ increased the collected extracts and icariin contents up to 29.6% and 0.76%, respectively, compared to 27.2%, 0.33% at 7$0^{\circ}C$. The yield of extracts was less dependent upon extracting temperature compared to icariin yield. Regarding extraction time, 4 hr and 6 hr resulted in high extracts and icariin yield, respectively. We found extracting Epimedium koreanum Nakai in 10 times volume of 10% EtOH for 4 and 6 hr at 9$0^{\circ}C$ seem to be relatively efficient methods for extracts and icariin, respectively.

• Korean Journal of Materials Research
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• v.23 no.10
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• pp.568-573
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• 2013

The deformation properties of a TiC-Mo eutectic composite were investigated in a compression test at temperatures ranging from room temperature to 2053 K and at strain rates ranging from $3.9{\times}10^{-5}s^{-1}$ to $4.9{\times}10^{-3}s^{-1}$. It was found that this material shows excellent high-temperature strength as well as appreciable room-temperature toughness, suggesting that the material is a good candidate for high-temperature application as a structure material. At a low-temperature, high strength is observed. The deformation behavior is different among the three temperature ranges tested here, i.e., low, intermediate and high. At an intermediate temperature, no yield drop occurs, and from the beginning the work hardening level is high. At a high temperature, a yield drop occurs again, after which deformation proceeds with nearly constant stress. The temperature- and yield-stress-dependence of the strain is the strongest in this case among the three temperature ranges. The observed high-temperature deformation behavior suggests that the excellent high-temperature strength is due to the constraining of the deformation in the Mo phase by the thin TiC components, which is considerably stronger than bulk TiC. It is also concluded that the appreciable room-temperature toughness is ascribed to the frequent branching of crack paths as well as to the plastic deformation of the Mo phase.