• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
• /
• pp.273-274
• /
• 2010

본 연구에서는 고로슬래그의 초기 강도의 증진과 응결지연의 단점을 개선하기 위해 고로 슬래그 및 석고가 혼입된 고로 슬래그를 대상으로 pH 변화에 따른 고로 슬래그의 표면 활성화의 특성과 quick-setting 특성에 관하여 연구하였다.

• 한국세라믹학회지
• /
• 제17권3호
• /
• pp.158-162
• /
• 1980

The experiments of suspension hydration were performed in the mixtures of slag and water or NaOH solutions which were made up with a liquid/solid ratio of 10. The liquid phase of the suspension was chemically analysed and discussed. When slag was in contact with water, CaO component was released from slag grains into the solution. The amounts of $SiO_2$ and $Al_2O_3$ liberated in the solution were very low as compared with CaO, for the impermeable coating of $SiO_2$, $Al_2O_3$-rich gel was formed on the surface of slag grains. The hydration was considered to be inhibited by this impermeable coating. The weak hydraulic property of slag was based on slowly released CaO and dissolved Na, K components which increased pH in the solution.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2010년도 추계학술발표논문집 2부
• /
• pp.878-881
• /
• 2010

For better diagnosis and prescription in Korean traditional medicine, Lee Je-Ma (1837-1900) created Sasang Constitution classification which was divided into four groups of Taeyangin, Soyangin, Taeumin and Soumin based on both body shape and natural disposition. The purpose of this study was to investigate the characteristics of facial skin parameters (hydration, lipid and pH) on forehead and cheek according to Sasang Constitution classifications of Taeumin, Soyangin and Soumin in Korean. Eighty-nine Korean female subjects were recruited for this study and the average age of them was 19.9${\pm}$0.84 years. The four groups by the Sasang Constitution were classified by questionnaire for the Sasang Constitution classification proposed by Kyung-Hee Oriental Medicine Hospital. Consequently, thirty-eight (42.7%) among the subjects were grouped into Soumin, twenty-nine (32.6%) into Taeumin, twenty (22.5%) into Soyangin and two (2%) into Taeyangin. Taeyangin group was excluded from statistical analysis due to small subjects. Hydration, lipid and pH parameters on forehead and cheek were measured by using non-invasive instruments of Corneometer (CM 825, Schwarzhaup, Germany), Sebumeter (SM 815, Schwarzhaup, Germany) and Skin-pH-meter (pH 905, Schwarzhaup, Germany), respectively. The measurements by the same investigator were performed under standardized condition with a room temperature of $21^{\circ}C$ and a humidity level of 40% to 50%. As a result, hydration (F=25.481, p=.000), lipid (F=5.753, p=.005) and pH (F=5.010, p=.009) of the forehead skin showed significant differences in the order of Taeumin, Soyangin and Soumin. Hydration (F=23.216, p=.000), lipid (F=6.898 p=.002) and pH (F=5.070, p=.008) of the cheek skin showed significant differences in the order of Taeumin, Soyangin and Soumin. In conclusion, facial skin surface seemed to be dependent on Sasang Constitution classification in Korean. These findings indicated that Sasang Constitution classification might be an useful esthetic treatment for caring facial skin in the future.

• Journal of Microbiology and Biotechnology
• /
• 제34권4호
• /
• pp.846-853
• /
• 2024

Adzuki bean (Vigna angularis), which provides plant-based proteins and functional substances, requires a long soaking time during processing, which limits its usefulness to industries and consumers. To improve this, ultrasonic treatment using high pressure and shear force was judged to be an appropriate pretreatment method. This study aimed to determine the optimal conditions of ultrasound treatment for the improved hydration of adzuki beans using the response surface methodology (RSM). Independent variables chosen to regulate the hydration process of the adzuki beans were the soaking time (2-14 h, X₁), treatment intensity (150-750 W, X₂), and treatment time (1-10 min, X₃). Dependent variables chosen to assess the differences in the beans post-immersion were moisture content, water activity, and hardness. The optimal conditions for treatment deduced through RSM were a soaking time of 12.9 h, treatment intensity of 600 W, and treatment time of 8.65 min. In this optimal condition, the values predicted for the dependent variables were a moisture content of 58.32%, water activity of 0.9979 a_w, and hardness of 14.63 N. Upon experimentation, the results obtained were a moisture content of 58.28 ± 0.56%, water activity of 0.9885 ± 0.0040 a_w, and hardness of 13.01 ± 2.82 g, confirming results similar to the predicted values. Proper ultrasound treatment caused cracks in the hilum, which greatly affects the water absorption of adzuki beans, accelerating the rate of hydration. These results are expected to help determine economically efficient processing conditions for specific purposes, in addition to solving industrial problems associated with the low hydration rate of adzuki beans.

• 약학회지
• /
• 제40권6호
• /
• pp.632-639
• /
• 1996

Most stable conformers of some antiinflammatory fenamates were obtained by conformational free energy change calculations. Conformational energies for the molecules as unhydrate d state were estimated first, and those as hydrated state were calculated then to simulate the molecules in aqueous solution using a hydration shell model. The initial geometries of the molecules were obtained either from X-ray crystallographic data or from homologous molecular fragments. The bond lengths and angles were not varied, but all the torsion angles were varied step by step during the conformational free energy surface searching. The results show that there are several feasible conformations for a compound. And the molecules are somewhat stabilized by hydration (-${\delta}G_{hyd}{\cong}$13 to 16kcal/mole), but the conformations were not changed significantly by the hydration itself. There seems to be a strong tendency of intramolecular hydrogen bonding between imino hydrogen and carboxyl oxygen of the compounds. As a result, the carboxyl group cannot be rotated freely, and the rotation of the second aromatic ring is the main reason for the conformational variations of the compounds. The ECEPP force fields via the program CONBIO were used throughout this study.

• Architectural research
• /
• 제20권1호
• /
• pp.27-34
• /
• 2018

To improve the chloride ingress resistance of concrete, slag is widely used as a mineral admixture in concrete industry. And currently, most of experimental investigations about non steady state diffusion tests of chloride penetration are started after four weeks standard curing of concrete. For slag blended concrete, during submerged chloride penetration tests periods, binder reaction proceeds continuously, and chloride diffusivity decreases. However, so far the dependence of chloride ingress on curing ages are not detailed considered. To address this disadvantage, this paper shows a numerical procedure to analyze simultaneously binder hydration reactions and chloride ion penetration process. First, using a slag blended cement hydration model, degree of reactions of binders, combined water, and capillary porosity of hardening blended concrete are determined. Second, the dependences of chloride diffusivity on capillary porosity of slag blended concrete are clarified. Third, by considering time dependent chloride diffusivity and surface chloride content, chloride penetration profiles in hardening concrete are calculated. The proposed prediction model is verified through chloride immersion penetration test results of concrete with different water to binder ratios and slag contents.

• Child Health Nursing Research
• /
• 제24권3호
• /
• pp.345-352
• /
• 2018

Purpose: The study was conducted to measure stratum corneum hydration (SCH) and pH (SCP) in high-risk newborns in the early postnatal period and to explore the features related to patterns of change in those parameters. Methods: SCH and SCP were measured on the dorsal hand in 99 hospitalized newborns during the first 14 days of life and the results were analyzed using a general linear model. Results: The mean hydration was 42.9% on day 1, which decreased to 34.6% by 2 weeks (F=15.61, p=<.001). An association was observed between SCH and prematurity (F=21.12, p<.001), as well as for their interaction (F=8.11, p<.001). The mean SCP was $6.2{\pm}0.3$ on day 1, and decreased to $5.7{\pm}0.2$ (F=95.75, p<.001), with no association with prematurity. After adjusting for birth weight, SCH was higher in newborns with vaginal delivery (F=9.07, p=.023) and who received phototherapy (F=11.81, p=.011). For SCP, only delivery type had a significant influence (F=6.40, p=.044). Conclusion: This study suggests that SCH is typically in the 30% range during the early postnatal period, and that an acid mantle on the SC surface is very unlikely to form; these findings could be applied to the nursing process for promoting skin integrity in high-risk neonates.

• 자원리싸이클링
• /
• 제12권1호
• /
• pp.41-47
• /
• 2003

대기에 방치된 생석회의 상온에서 내수화성을 향상시키기 위해 생석회의 탄산화반응과 수화반응실험을 수행하였다. 제강공정에서 사용시까지 수화반응을 억제시키기 위해서는 생석회 표면을 약 6%정도 탄산화시킬 필요가 있었다. 생석회의 탄산화를 위한 회전로 배가스 재순환이 평형연소온도 및 NOx농도에 미치는 영향을 열역학적으로 계산한 결과, 배가스 부피 백분율이 증가함에 따라 연소온도와 NOx농도는 감소하였다.

• Bulletin of the Korean Chemical Society
• /
• 제12권2호
• /
• pp.143-148
• /
• 1991

In the unhydrated and hydrated states, conformational free energies of L-ascorbic acid anion (AAA) were computed with an empirical potential function and the hydration shell model (a program CONBIO). The conformational energy was minimized from possible starting conformations expressed with five torsion angles of the molecule. The conformational entropy of each low energy conformation in both states was computed using a harmonic approximation. As found in L-ascorbic acid (AA), intramolecular hydrogen bonds (HBs) are proved to be of significant importance in stabilizing the overall conformations of AAA in both states, and give the folded conformations, which are quite different from those in crystal. There are competitions between HBs and hydration around O3 atom of the lactone ring and hydroxyls of the acyclic side chain. Especially, the whole conformation of AAA is strongly dependent on the water-accessibility of O3 atom. Though there is a significant effect of the hydration on conformational surface, the lowest energy conformation of the unhydrated AAA is conserved. The different patterns of HBs and hydration result in the conformations of AAA in both states being different from those of AA. It can be drawn by several feasible conformations obtained in the hydrated state that there exists an ensemble of several conformations in aqueous solution.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.681-684
• /
• 2006

Control of the temperature difference across a section is an effective way to minimize the hydration-heat-induced cracks for the structures where internal restraint is dominant. However, surface temperature may not be easily measured in situ due to the difficulty in maintaining the correct location during casting. A prediction equation for the temperature difference is proposed which can be applied without directly measuring the surface temperature if the curing condition and ambient temperature are known. Some strategies to control the temperature difference are revisited and a reasonable range of the temperature difference to minimize the crack is discussed.