• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.500-506
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• 2000

The effects of sodium stearoyl lactylate(SSL) on the thermal properties of wheat starch and amylopectin, and the crystallinity properties of amylopectin were investigated using differential scanning calorimetry(DSC) and X-ray diffractometer. On the rescan(second heating), amylopectin produced the featureless thermogram shown at the second heating, and SSL alone melted at $40{\sim}55^{\circ}C$, while the mixture of amylopectin containing 8% water and SSL(10:1), presenting the evidence of AP-SSL complex, showed differentiate melting temperature(other crystallinity) from SSL alone. Also, the melting enthalpy of AP and SSL mixture by subsequent heating and cooling were continuously increased. Further, the mixtures of wheat starch: SSL (5:1, w/w) and amylopectin: SSL(5:1, w/w), indicated AP-SSL complex, showed the reversible melting peak at temperature range of $60{\sim}70^{\circ}C$ together with melting peak of SSL observed at temperature range of $40{\sim}55^{\circ}C$. AP-SSL complex in the X-ray diffraction, compared V-form of amylose-lipid complex, exhibited characteristic peaks($2{\theta}$, 5.57, 20.903, 23.227). The gelatinization enthalpy value of wheat starch in the presence of SSL, observed at temperature range of $50{\sim}70^{\circ}C$, was decreased at total water content 60%, whearas had no significant effect at total water content 40, 50%, and also, SSL increased melting enthalpy of amylose-lipid complex. The extent of AP and wheat starch retrogradation wasreduced significantly by SSL.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.822-829
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• 2017

As a method to reduce the total phosphorus in sewage treatment plant, we applied the integral type slow mixing/sedimentation fiber filtration system to compare the control methods for the sewage effluent and the reject water. It was analyzed that about 92.4 kg T-P/day should be removed in order to satisfy the final concentration of phosphorus of 0.2 mg T-P/L, which is reinforced effluent standard. Therefore the total phosphorus removal efficiency should be 96% for sewage effluent and 69.2% for reject water (dehydrated filtrate) respectively. The system operation cost to achieve the target of total phosphorus removal efficiency was assessed. It has been found that the treatment cost of the reject water containing high concentration of phosphorus with a low flow rate is reduced to about 1/2.4 of the coagulant cost and about 1/120 of the electricity cost, compared to that of the sewage effluent treatment. Also the economics of the integral type slow mixing/sedimentation fiber filtration system and the general coagulation and sedimentation system were compared. It was evaluated that the development system was more economical because the installation area of the integral type slow mixing/sedimentation fiber filtration system was about 1/7 smaller than that of the general coagulation and sedimentation system, and the annual operation cost including the required amount of coagulant and electricity cost of the development system was lowered about 1/1.7 than that of the general system.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.816-821
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• 2017

An integrated slow mixing/sedimentation and net fit fiber filtration system has been developed to reduce the high concentrations of suspended solid (SS) and total phosphorus (T-P) in the reject water from sewage/wastewater. A filtration device used in this experiment consists of coagulation, in-line mixing, air injection, slow mixing/sedimentation, and filtration processes. The performance test using this device was carried out with six operational modes for reject water from sewage treatment plant. Experimental conditions used were 16.7, 33.3, 41.7 and 50.0 ton/day of flow rate and 2~4 of Al/P molar ratio. By injection of coagulant in each operational mode, the high removal efficiencies of SS and T-P were obtained, but continuous operation time was decreased to 7.8~11.4 min in most modes. However, when the Mode 5 of the developed filtration device was applied, the continuous operation time was maintained up to 88.2 min. Also, it was found that the continuous operation time in the Mode 5 using the developed system was increased from 8 to 11.3 times longer than those in other modes. Backwashing flow rate was also very low at 5.4% of total filtered water. Therefore, it can be concluded that the Mode 5 of the developed filtration system was the most efficient treatment method for the removal of high concentrations of SS and T-P.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1129-1136
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• 1999

TIN films were prepared on Si(100) substrate by ICP-CVD(inductive1y coupled plasma enhanced chemical vapor deposition) using TEMAT(tetrakis ethylmethamido titanium : Ti$[\textrm{N}\textrm{(CH)}_{3}\textrm{C}_{2}\textrm{H}_{5}]_{4}$) precursor at various deposition conditions. Phase, microstructure, and the electrical properties of TIN films were characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and electrical measurements. Polycrystalline TiN films with B1 structure were grown at temperatures over $200^{\circ}C$. Preferentially oriented along TiN(111) films were obtained at temperatures over $300^{\circ}C$ with the flow rates of 10, 5, and 5 sccm for TEMAT, $\textrm{N}_{2}$ and Ar gas. The TiN/Si(100) interface was flat and no chemical reaction between TIN and $\textrm{SiO}_2$ was found. The resistivity, carrier concentration and the carrier mobility for the TiN sample prepared at $500^{\circ}C$ are 21 $\mu\Omega$cm, 9.5$\times\textrm{10}^{18}\textrm{cm}^{-3}$ and $462.6\textrm{cm}^{2}$/Vs, respectively.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.362-367
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• 2006

This study was conducted to evaluate the feasibility of determination of hydroxyproline (Hyp) contents in pork meat for the quality evaluation of meat products. The relationship between the Hyp contents and pork grade was not high in porcine semitendinosus muscle. Whereas, Hyp contents of pork fresh ham and hamburger patties prepared with them were significantly increased as the decrease of pork grade. These results showed that the determination of Hyp contents might be a useful method for the quality evaluation of meat products.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.399-404
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• 1996

Encapsulation of lysozyme using lecithin vesicles and its stimilated release properties were studied. Lecithin vesicles were prepared by the dehydration-rehydration (DR)method. The highest encapsulation efficiency (EE) value of 80.1% was obtained by sonicating the multilamellar vesicles (MLVs) at 100 KHz for 120 min in bath sonicator. The value of entrapment progressively increased with the concentration of lysozyme, while the EE value decreased with the increase of enzyme concentration up to 50mg per 100mg per 100mg of lecithin, and then became nearly constant. At the pH of 5.9, only a small amount of lysozyme was released from DR vesicles during incubation at $37^{\circ}C$ As the pH decreased to 3.0, lysozyme was released more rapidly. Lysozyme release was accelerated for 24h and reached a plateau after 72h incubation with 1% Tween 80, $Ca^{2+}$ gave a pulse-like-release in the first hour, which was followed by a slow release.

• Journal of Korea Water Resources Association
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• v.48 no.4
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• pp.309-319
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• 2015

River characteristics in South Korea has been affected by seasonal climatic variability due to climate change and by remarkable land cover change due to rapid economic growth. In this regard, the roles of river management is getting more important to eco-system and human community in watersheds of South Korea. Understanding river characteristics including direct runoff and baseflow, the first step of river management, can give a significant contribution to sustainable river environment. Therefore, the objective of this study is to quantify the contributions of the direct runoff and baseflow to river streamflow. For this, we used the BFLOW and WHAT programs to conduct baseflow separation for 71 streamflow gauge stations in Han River system, South Korea. The results showed that baseflow index for 71 stations ranges from 0.42 to 0.78. Also, gauge stations which have baseflow index more than 0.5 occupied 76% of a total stations. However, baseflow index can be overestimated due to human impacts such as discharge from dams, reservoirs, and lakes. This study will be used as fundamental information to understand river characteristics in river management at the national level.

• Membrane Journal
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• v.26 no.3
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• pp.205-211
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• 2016

Performance of pyrophyllite-based ceramic membranes newly developed were investigated. Membrane fouling caused by microbial suspensions taken from a full-scaled MBR system at domestic wastewater treatment plant was observed at different airflow rate and distance between each membrane. For the pyrophyllite support, pore size was about $1.0{\mu}m$, but surface coating with $Al_2O_3$ solution decreased the pore size with the reduction of the pure water permeability. With the MLSS taken from the full-scaled MBR system (6 g/L), the fouling rate was decreased by increasing airflow rate under $20L/m^2{\cdot}hr$ of setpoint flux. However, the effectiveness of the airflow rate on the fouling control depends strongly upon the gap between each membrane. At fixed airflow rate, the fouling rate was decreased by increasing the gap between each pyrophyllite membrane. Nevertheless, further increasing the membrane distance from 3.5 to 5.4 cm resulted in higher fouling rate. Similar result was observed with the $Al_2O_3$ coated-pyrophyllite membrane. Nevertheless, the fouling rate was lower with the coated membrane than that observed with the uncoated pyrophyllite support. Regardless of surface coating, the suspended solids were removed almost completely and the surface coating on the pyrophyllite support improved organic rejection with PEG solution (MW : 8000 kDa) tested.

• Membrane Journal
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• v.26 no.2
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• pp.126-134
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• 2016

To produce renewable biomethane from biogas, the properties of physical absorbents such as water, methanol, 1-methyl-2-pyrrolidone (NMP), poly(ethylene glycol) dimethylether (PEGDME), and propylene carbonate (PC) were studied, and PC was applied to membrane contactor systems. Among physical absorbents, PC exhibited a high contact angle of $58.3^{\circ}$ on polypropylene surface, and a PC/water mixture (5 wt%) increased the contact angle to $90^{\circ}$. Furthermore, the PC/water mixture presented higher $CO_2$ absorption capacities (0.148-0.157 mmol/g) than that of water (0.121 mmol/g), demonstrating a good property as an absorbent for membrane contactors. Actual operations in membrane contactors using the PC/water mixture resulted in $CO_2$ removal of 98.0-97.8% with biomethane purities of 98.5-98.3%, presenting a strong potential for biogas treatment. However, the PC/water mixture yielded moderate improved in $CO_2$ removal and methane recovery, as compared with water in the membrane contactor operation. This is originated from insufficient desorption processes to reuse absorbent and low $CO_2$ flux of the PC/water absorbent. Thus, it is requiring optimizations of membrane contactor technology including development of absorbent and improvement of operation process.

• Membrane Journal
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• v.22 no.3
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• pp.201-207
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• 2012

In this study, we investigated permeation of single gas ($N_2$, $O_2$, $CF_4$, and $SF_6$) through flat sheet membrane composed of PDMS (poly-dimethylsiloxane) and PEBAX (polyether block amides). Gas permeation experiment was performed with various feed pressure. Permeability was estimated using permeation flux measured by continuous-flow technique. The permeability of gases except $SF_6$ in PDMS were decreased with the upstream pressure increased. $SF_6$ is much more permeable than $CF_4$, which is due to higher critical temperature of $SF_6$. The permeability decreased in the following order: $O_2$ > $N_2$ > $SF_6$ > $CF_4$. On the other hand, the permeability of gases in PEBAX followed the order: $O_2$ > $N_2$ > $CF_4$ > $SF_6$ which are opposite of the order of kinematic diameter (${\AA}$)($SF_6$ > $CF_4$ > $N_2$ > $O_2$). The $SF_6/CF_4$ pure gas selectivity in PDMS was 2.1 at 0.7 MPa.