• Clean Technology
• /
• v.24 no.1
• /
• pp.1-8
• /
• 2018

As the social demands for environmental pollution increase and regulations on the dyeing process wastewater are strengthened, supercritical dyeing process has been attracting attention as an alternative technology to reduce wastewater and energy consumption. In the supercritical dyeing process where carbon dioxide is used as a solvent instead of water as a solvent, there is no wastewater generated. The unfixed dyes can be reused later which makes the process environment-friendly. Also, after dyeing process, dried textiles can be obtained without additional drying process, which makes the process energy efficient. In this article, we have summarized the development of the supercritical dyeing process along with the research in Korea today and compared the principle of supercritical dyeing process with conventional dyeing process. To further explain the principle, studies of the distribution factor and mass transfer of dyes in supercritical carbon dioxide and fibers, as well as solubility between supercritical $CO_2$ and dyes are discussed. The dynamic behavior of dyes in supercritical dyeing apparatus and summary of the supercritical dyeing facilities developed around the world are also discussed. Finally, we suggest the direction of research and development for optimization of supercritical dyeing process and application to synthetic fibers and natural fibers except for polyester.

• The Journal of Korean Academy of Prosthodontics
• /
• v.49 no.2
• /
• pp.106-113
• /
• 2011

The object of this clinical study was to evaluate the short-term outcome of modified resin-bonded fixed partial dentures which utilizes the original tooth undercuts and different path of insertion of components. Materials and methods: 71 units of modified RBFPDs that were used in 21 patients at the Department of Prosthodontics, College of Dentistry, Yonsei University were evaluated. The follow-up period was up to 25 months, the mean being 7 months. Survival rate, mobility, percussion, probing depth, bleeding on probing, plaque index was recorded and radiographs were taken to monitor alveolar bone loss. Results & Conclusion: Within the limits of this short term retrospective study, it was concluded that: 1. No mechanical failure such as debonding or fracture of the framework was found during the follow-up period. 2. The periodontal apparatus was stable and no clinical change was observed after prosthetic treatment. 3. No significant marginal bone loss was found in the radiographic evaluation.

• Nuclear Engineering and Technology
• /
• v.48 no.1
• /
• pp.274-284
• /
• 2016

Purpose: The purpose of this work is to describe the spectrometric analysis of gaseous cloud formation over reactor mixed uranium-and-plutonium (UP) fuel $(U_{0.8}Pu_{0.2})O_2$ samples heated to a temperature $>2,000^{\circ}C$, and thus forecast and evaluate radiation hazards threatening humans who cope with the consequences of any accident at a fission reactor loaded by UP mixed oxide $(U_{0.8}Pu_{0.2})O_2$, such as a mixture of 80% U and 20% Pu in weight. Materials and methods: The UP nuclear fuel samples were heated up to a temperature of over $2,000^{\circ}C$ in a suitable assembly (apparatus) at out-of-pile experiments' implementation, the experimental in-depth study of metabolism of active materials in living organisms by means of artificial irradiation of pigs by plutonium. Spectrometric measurements were carried out on the different exposed organs and tissues of pigs for the further estimation of human internal exposure by nuclear materials released from the core of a fission reactor fueled with UP mixed oxide. Results: The main results of the research described are the following: (1) following the research on the influence of mixed fuel fission products (radioactive isotopes being formed during reactor operation as a result of nuclear decay of elements included into the fuel composition) on living organisms, the authors determined the quantities of plutonium dioxide ($PuO_2$) that penetrated into blood and lay in the pulmonary region, liver, skeleton and other tissues; and (2) experiments confirmed that the output speed of plutonium out of the basic precipitation locations is very small. On the strength of the experimental evidence, the authors suggest that the biological output of plutonium can be disregarded in the process of evaluation of the internal irradiation doses.

• Journal of Korea Water Resources Association
• /
• v.41 no.3
• /
• pp.305-314
• /
• 2008

Urban sewer systems are designed to operate in open-channel flow regime and energy loss at circular manholes are usually not significant. However, the energy loss at manholes, often exceeding the friction loss of pipes under surcharge flow, is considered as one of the major causes of inundation in urban area. Therefore, it is necessary to analyze the head loss associated with manholes, especially in surcharge flow. Hydraulic experimental apparatus which can be changed the invert type(CASE A, B, C) and step height(CASE I, II, III) was installed for this study. The range of the experimental discharges were from $1.0{\ell}/sec$ to $5.6\;{\ell}/sec$. As the manhole diameter ratio($D_m/D_{in}$) increases, head loss coefficient increases due to strong horizontal swirl motion. Head loss coefficient was maximum because of strong oscillation of water surface when the range of manhole depth ratios($h_m/D_{in}$) were from 1.0 to 1.5. The average head loss coefficients for CASE A, B, and C were 0.45, 0.37, and 0.30, respectively. Accordingly, U-invert is most effective for energy loss reduction at circular manhole. This head loss coefficients could be available to design the urban sewer system with surcharge flow.

• Food Science and Preservation
• /
• v.24 no.1
• /
• pp.52-59
• /
• 2017

This study was performed in order to examine the effect of a thermoelectric cooling system combined with plasma on beef. Beef was studied in a box with a thermoelectric cooling system and plasma generation apparatus (TCS-1), a box with thermoelectric cooling system (TCS-2) and a polystyrene box (control). A temperature inside the thermoelectric cooling system was kept below $2^{\circ}C$, and volatile basic nitrogen (VBN) values of TCS-1 and TCS-2 were 7.72 mg% and 9.20 mg%, respectively. The thiobarbituric acid (TBA) value (0.52 mgMA/kg) of TCS-1 was significantly lower than that (0.91 mgMA/kg) of TCS-2. For volatile basic nitrogen (VBN) value, TCS-1 maintained freshness compared to TCS-2, since the freshness of TCS-1 value (6.98-9.77 mg%) was less than that of TCS-2 (6.98-11.45 mg%) during storage. The microbial counts of TCS-1 and TCS-2 were 4.62 log CFU/g and 7.09 log CFU/g, respectively, on the $7^{th}$ day, which were lower than that (8.45 log CFU/g) of control on the $3^{rd}$ day. Sensory evaluation of TCS-1 showed the highest scores for appearance, color, juiciness, and overall acceptability than the others. In conclusion, TCS-1 was effective for maintaining freshness of beef during storage.

• YAKHAK HOEJI
• /
• v.47 no.5
• /
• pp.339-344
• /
• 2003

Atenolol is a water soluble, ${\beta}_1$ selective adrenoceptor antagonist used in the treatment of angina and hypertension. It is primarily eliminated renally with minimal hepatic metabolism. The purpose of the present study was to evaluate the bioequivalence of Samchundang Atenolol (Samchundang Pharmaceutical Co., Korea.) to Tenolmin(Hyundai Pharmaceutical Ind. Co., Korea). The atenolol release from the two atenolol tablets in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four normal male volunteers, 22.83$\pm$1.99 years in age and 65.82$\pm$7.15 kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 50 mg of atenolol was orally administered, blood was taken at predetermined time intervals and the concentrations of atenolol in serum were determined using HPLC method with fluorescence detector. The dissolution profiles of two atenolol tablets were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AUC_{t}$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_{t}$ and $C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AUC_{t}$, $C_{max}$ and $T_{max}$ between two tablets based on the Tenolmin were 3.74％, 4.38％ and 17.77％, respectively. There were no sequence effects between two tablets in these parameters. The 90％ confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., log(0.98)∼log(1.l1) and log(0.95)∼log(1.l5) for $AUC_{t}$ and $C_{max}$ respectively), indicating that Samchundang Atenolol tablet is bioequivalent to Tenolmin tablet.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.154-163
• /
• 2005

Chemical and flavor components of Bulro Kugi (Lycium chinense Mill) fruit leaf, and root were compared. Fructose and glucose were detected in fruit and leaf, and sucrose in root, respectively. Citrate was the highest among organic acids in fruits, and malate in leaf and root Capsaicin was detected in leaf and root. Volatile flavor compounds were extracted by simultaneous distillation and extraction method using Likens and Nickerson's extraction apparatus. Concentrated flavor extract was analysed, and 128 compounds, including 22 acids 15 alcohols, 12 aldehydes, 8 esters, 10 furans, 26 hydrocarbons, 4 phenols, 2 pyrroles, 1 pyrazine, and 28 miscellaneous components. were identified by GC and GC-MS. Main volatile compounds were hexadecanoic acid and 2-furancarboxaldehyde in hot-air dried fruit, hexadecanoic acid and 1-hexadecene in fresh fruit, 3, 7, 11, 15-tetranethyl-2-hexadecan-1-ol and hexadecanoir acid in leaf, and hexadecanoic acid in root.

• Korean Journal of Food Science and Technology
• /
• v.36 no.2
• /
• pp.196-201
• /
• 2004

Volatile components in flower and seed of safflower were identified. Volatile flavor compounds of safflower (Carthamus tinctorius L.) was extracted by simultaneous steam distillation and extraction method using Likens and Nickerson's extraction apparatus. Concentrated extract was analyzed and identified by gas chromatography and GC-mass spectrometry. Main volatile components in flower were terpene compounds, including p-cymene, limonene, ${\alpha}-phellandrene$, ${\gamma}-terpinene$, camphor, 4-terpineol, selinene, ${\beta}-caryophyllene$, torreyol, ${\beta}-eudesmol$, and 10 acids including 3-methylbutanoic acid, 2-methylbutanoic acid, and acids of $C_{2},\;C_{5}-C_{11}$. Main volatile components in seed and safflower were 20 aldehydes including hexanal (7.17%), (E)-2-heptenal (1.10%), (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal.

• Korean Journal of Food Science and Technology
• /
• v.11 no.3
• /
• pp.157-161
• /
• 1979

The apparatus and method that permit rapid and continuous determination of thermal conductivity and diffusivity of Kochujang, Korean native semi-solid food, are presented. 1. The thermal conductivities of Kochujang are $0.3517\;kcal/mh^{\circ}C$ at $25^{\circ}C$, $0.3957\;kcal/mh^{\circ}C$ at $50^{\circ}C$ and $0.4221\;kcal/mh^{\circ}C$ at $100^{\circ}C$. Thermal diffusivity of Kochujang is $0.1000\;cm^2/min$ at $50^{\circ}C$, specific heat and density are $0.573\;kcal/kg^{\circ}C$, $1,220\;kg/m^3$, respectively. 2. There exists 6.04% discrepancy between the measured value and the calculated one from specific heat and density values.

• Korean Journal of Medicinal Crop Science
• /
• v.2 no.1
• /
• pp.81-85
• /
• 1994

This experiment was carried out to investigate the fertilization and the size of mature female and male gametophytic parts of Pulsatilla koreana after artificial pollination. The size of pollen is $26.5{\mu}m$ at the time of anther dehiscence, that is, about $3{\sim}4$ days after pollination. Synergid nucleus, egg nucleus, and polar nucleus are 10.0, 15.0, and $32.5{\mu}m$ respectively at the time of completing egg apparatus formation, that is, about 2 days after pollination. Poller tubes germinate on stigma about 10 hours, passing lower part of style about 30 hours, penetrating into micropyle about 35 hours after pollination. Sperm nucleus penetrates into polar nucleus about 40 hours and egg cell about 48 hours after pollination. But, there seems to be different among the individuals. Multinuclei and multinucleoli are formed in egg cell, synergid, and polar nucleus about the time of fertilization. Proembryo is formed about 4 days, being changed to large globular form about $6{\sim}8$ days after pollination. Endosperm nuclei divide into free nuclei after fertilization and change to cotyledon in gymnosperm. There seems to be same phenomena in Pulsatilla koreana.