• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.3
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• pp.273-282
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• 2020

Aloe vera (Aloe barbadensis Miller) has been used since ancient times to improve various skin diseases such as burns, wounds, and eczema. It has been reported that Aloe vera contains vitamin, enzyme, mineral, sugar, phenolic compound, fatty acid and amino acid. Aloe vera changes its color from green to red under the extreme thermal and arid climate to protect itself. These morphological changes induce variation of composition such as increasing of aloe-emodin content. Aloe-emodin is one of the major anthraquinone in aloe family plants. Since aloe-emodin contains a polyphenolic structure, this compound may be responsible for the reported antioxidant and anti-inflammatory effects of aloe. However, there is no research on the process of increasing the compounds of Aloe vera. Therefore, the purpose of this study is to develop a pink aloe manufacturing process that increases the aloe-emodin content and enhances the antioxidant and anti-inflammatory activities of aloe. As a result of heating aloe under appropriate conditions, pink aloe increased aloe-emodin content compared to general aloe, and exhibited effects such as increasing antioxidant activity, inhibiting NO production, and promoting cell regeneration. Through this study, the applicability of pink aloe as a new anti-aging material in the cosmetic field was confirmed.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.443-451
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• 2020

In this study, the physico-chemical properties and pyrolysis kinetics of livestock mature solid fuel were investigated to know its feasibility as a fuel. Ultimate and proximate analysis results showed that livestock mature solid fuel has high contents of volatile matter (64.94%), carbon (44.35%), and hydrogen (5.54%). The low heating value of livestock mature solid fuel (3880 kcal/kg) was also higher than the standard requirement of solid fuel (3000 kcal/kg). Thermogravimetic analysis results indicated that livestock mature solid fuel has three decomposition temperature regions. The first temperature zone (130~330 ℃) was consisted with the vaporization of extracts and the decomposition of hemicellulose and cellulose. The second (330~480 ℃) and third (550~800 ℃) temperature regions were derived from the decomposition of lignin and additional decomposition of carbonaceous materials, respectively. The activation energy derived from model free kinetic analysis results including Friedman, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods for the pyrolysis of livestock mature solid fuel was in the range of 173.98 to 525.79 kJ/mol with a conversion rate of 0.1 to 0.9. In particular, the activation energy increased largely at the higher conversion than 0.6. The kinetic analysis using a curve-fitting method suggested that livestock mature solid fuel was decomposed via a multi-step reaction which can be divided into five decomposition steps.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.15-21
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• 2004

This paper describes the development of $^{99m}Tc$ tricarbonyl cysteine as potential renal function diagnostic radiopharmaceutical and evaluation of its biological characteristics using experimental animals. l-Cysteine was labeled efficiently with $^{99m}Tc$ tricarbonyl precursor $([^{99m}Tc(CO)_3(H_2O)_3)]^{+})$ under 30 min heating at ${75^{\circ}C}$. Labeling yield and stability were analyzed by high performance liquid chromatography (HPLC). The biodistribution property of $^{99m}Tc$ tricarbonyl cysteine in mice and its dynamic imaging profiles in rabbits were carried out. To investigate the excretion mechanism of $^{99m}Tc$ tricarbonyl cysteine, tubular transport inhibition test with probenecid was adopted. $^{99m}Tc$ tricarbonyl cysteine was obtained with a high labeling yield under the moderate condition. The results of biodistribution experiments of $^{99m}Tc$ tricarbonyl cysteine in ICR mice at 3 and 90 min provided that $^{99m}Tc$ tricarbonyl cysteine was very highly accumulated in the kidney and bladder, thereby almost 99% of $^{99m}Tc$ tricarbonyl cysteine was excreted within 90 min post injection. The same results were confirmed by the whole body dynamic images for 30 minutes and static images in rabbits at given time intervals after injection. Renogram of $^{99m}Tc$ tricarbonyl cysteine in rabbits showed that its $T_{max}$ and $T_{1/2}$ of $^{99m}Tc$ tricarbonyl cysteine were $2.33{\pm}0.56$ and $4.30{\pm}0.79$ min, respectively. The $T_{max}$ of $^{99m}Tc$ tricarbonyl cysteine with probenecid pretreatment was $2.30{\pm}0.17$ min, whereas $T_{1/2}$ of that with probenecid pretreatment was $17.0{\pm}32.47$ min. $T_{1/2}$ of $^{99m}Tc$ tricarbonyl cysteine with probenecid pretreatment was significantly different, as compared to the result without probenecid (p<0.0001). The results showed that the excretion of $^{99m}Tc$ tricarbonyl cysteine was extremely affected by probenecid. Therefore, $^{99m}Tc$ tricarbonyl cysteine was rapidly excreted from the kidney principally by the tubular secretion.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.125-131
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• 2015

Phenyllactic acid (PLA) which is known as antimicrobial compound can be synthesized through the reduction of phenylpyruvic acid (PPA) by lactate dehydrogenase (LDH) of lactic acid bacteria (LAB). LAB producing PLA was isolated from Korea Kimchi and identified to Lactobacillus plantarum SJ21 by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. plantarum SJ21 was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against four fungal pathogens (Rhizoctonia solani, Aspergillus oryzae, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23mM in CFS when L. plantarum SJ21 was grown in MRS broth containing 5mM PPA for 16 h. PLA production also could be promoted by the supplement of PPA and phenylalanine in MRS broth, but inhibited by the supplement of 4-hydroxyphenylpyruvic acid and tyrosine as precursors. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. plantarum SJ21 with average growth inhibitions ranging from 27.32% to 69.05% (p<0.005), in which R. solani was the most sensitive to 69.05% and followed by B. cinerea, C. aculatum, and A. oryzae. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range from $0.35mg\;mL^{-1}$ (2.11 mM) to $0.7mg\;mL^{-1}$ (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens was not affected by heating or protease treatment. However, pH modification in CFS to 6.5 caused an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS were caused by acidic compounds like PLA or organic acids rather than proteins or peptides molecules.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5344-5351
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• 2013

Chambers in a continuous furnace were designed. A chamber consists of inlets and outlets of nitrogen gas which is used to discharge burned gas and heating pipes (HP) which are used to keep temperature of fired materials at $1,300^{\circ}C$. Design variables were numbers of inlets and outlets, distance between floor and lower HP ($h_1$), distance between lower HP and fired materials ($h_2$), distance between fired materials and upper HP ($h_3$), temperature of HP, numbers of HP and distance between HP. The numbers of inlets and outlets were determined so that nitrogen gas formed a laminar flow for efficient discharge. All other design variables were determined so that temperature of fired materials is as uniform as possible near $1,300^{\circ}C$. Chambers were produced and temperature was measured at 21 points using thermocouples. The largest deviation from $1,300^{\circ}C$ was less than ${\pm}2.2^{\circ}C$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.163-170
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• 2012

With the advantage of a rapid exothermic reaction property, jet set concrete may be used as a cold weather concrete because it can reach the required strength before being damaged by cold weathers. And it can be hardened more quickly if the field temperature is properly compensated by heating. Because ordinary concrete cannot be hardened well under sub-zero temperatures, anti-freeze agents are typically added to prevent the frost damage and to ensure the proper hardening of concrete. While the addition of a large amount of anti-freeze agent is effective to prevent concrete from freezing and accelerates cement hydration resulting in shortening the setting time and enhancing the initial strength, it induces problems in long-term strength growth. Also, it is not economically feasible because most anti-freeze agents are mainly composed of chlorides. Recent studies reported that magnesia-phosphate composites can be hardened very quickly and hydrated even in low temperatures, which can be used as an alternative of cold weather concrete for cold weathers and very cold places. As a preliminary study, to obtain the material properties, mortar specimens with different mixture proportions of magnesia-phosphate composites were manufactured and series of experiments were conducted varying the curing temperature. From the experimental results, an appropriate mixture design for cold weathers and very cold places is suggested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.729-733
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• 2006

Small yellowish brown crystals were found in some concentrated oyster extracts which prepared by heating with the drip and washed water of boiled oyster in oyster processing factories. We collected those crystals by filtering the oyster extracts and analysed X ray diffraction (XRD), scanning electron microscopy (SEM) and minerals by ICP. Those were composed of moisture (8.1%), organic materials (21.6%) and inorganic materials (70.2%). Those major inorganic materials were determined as Ca (53.8%) and P (43.8%), from the ICP and elucidated those crystal as brushite $(CaHPO_4{\cdot}2H_2O)$ by XRD and SEM. Organic materials contained crude protein (33.7%) consisting of 7 amino acids. It is presumed that brushite may be formed by the reaction of excess Ca with P in the oyster extracts during concentrating process under higher temperature.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.6
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• pp.730-740
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• 1999

The purpose of this study was to investigate setting and thermal expansion of dental soldering investments. In order to compare expansion rates and to investigate the effect of water/powder ratio on expansion, setting and thermal expansion of low dental soldering investments were measured under three different water/powder ratio conditions. standard, 20% decreased and 20% increased. Setting expansion of investments was measured by use of dialgauge method. Each measurement was started two minutes later from the beginning of spatulation and recorded every one minute for one hour. Thermal expansion of cylindrical test specimens, 10mm diameter, 50mm length, was recorded in a thermodilatometer at heating rate of $10^{\circ}C$ per minute from $25^{\circ}C\;to\;700^{\circ}C$. The results of this study were obtained as follows: 1. Setting expansion rates under the standard water/powder ratio condition were 0.198% in Speed-E, 0.090% in Deguvest, 0.080% in CM and Hi-temp. Setting expansion of Speed-E was significantly different from those of CM, Deguvest and Hi-temp, and setting expansion of Deguvest was significantly different from those of CM and Hi-temp(p<.05). 2. Under the decreased water/powder ratio condition, there was significant increase in setting expansion of 4 dental soldering investments (p<.05). 3. There were no significant differences in setting expansions of investments except Hi-temp between standard and increased water/powder ratio condition(p<.05). 4. Thermal expansion rates under the standard water/powder ratio condition were 1.923% in Deguvest, 1.629% in Speed-E, 1.619% in Hi-temp and 1.580% in CM. No significant differences in thermal expansions under the standard water/powder ratio condition existed only between Speed-I and Hi-temp(p<.05) 5. Under the decreased water/powder ratio condition, there was significant increase in thermal expansion of CM and Deguvest but decrease in thermal expansion of Speed-E (p<.05). 6. Under the increased water/powder ratio condition, there was significant decrease in thermal expansion of CM, Deguvest and Speed-I but decrease in thermal expansion of Hi-temp(p<.05).

• Tunnel and Underground Space
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• v.21 no.6
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• pp.518-525
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• 2011

In this study, the natural ventilation pressure resulting from the large altitude difference which is a characteristic of high radioactive waste repository and the caloric value of the heat emitted by wastes was calculated and based on the results, natural ventilation quantities were calculated. A high radioactive waste repository can be considered as being operated through closed cycle thermodynamic processes similar to those of thermal engines. The heat produced by the heating of high radioactive wastes in the underground repository is added to the surrounding air, and the air goes up through the upcast vertical shaft due to the added heat while working on its surroundings. Part of the heat added by the work done by the air can be temporarily changed into mechanical energy to promote the air flow. Therefore, if a sustained and powerful heat source exists in the repository, the heat source will naturally enable continued cyclic flows of air. Based on this assumption, the quantity of natural ventilation made during the disposal of high radioactive wastes in a deep geological layer was mathematically calculated and based on the results, natural ventilation pressure of $74{\sim}183$Pa made by the stack effect was identified along with the resultant natural ventilation quantity of $92.5{\sim}147.7m^3/s$. The result of an analysis by CFD was $82{\sim}143m^3/s$ which was very similar to the results obtained by the mathematical method.

• Land and Housing Review
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• v.3 no.4
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• pp.357-367
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• 2012

The efficient business scheme were suggested with the consideration of the local development condition at Ulaanbaatar. Major findings of the study were presented as follows. First, high level of education and the underground resources are presented as the merits of Mongolia. On the other side, the defects are limited domestic demands of 2.6 millions of population and the insufficiency of the infrastructure. The improvement of the infrastructures like roads, water & sewage, electric power, and heating is urgent while the development pressure of Ulaanbaatar is expected to be high due to the continuous inflow of population. Secondly, the Mongolian land system consists of the right of ownership, lease and use, therefore there are some differences among the right of land. Thirdly, definite business scheme to sell land in lots and to sell buildings in lots are suggested which are actual methods to participate in the development project in Ulaanbaatar. Moreover, enhancing the possibility to sell the lands, fixing the proper sale price to secure the profit, finding the proper buyer for the profitable lands, investing of quota and guaranteeing of granting the principal and interest by the Mongolian government, etc. are presented as consideration when participate in projects.