• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.24 no.5
• /
• pp.345-355
• /
• 1991

In order to effectively utilize the by-products of sea-food, the utilization of enzyme-modified flounder(Limanda aspera) skin gelatin as an emulsifier was investigated. In the experiment, the gelatin was extracted from the flounder skin with the heat-treatment at $60^{\circ}C$ and in pH 5.0 for 3 hrs with four volumes of distilled water and emulsifiers were enzymatically modified L-leucine alkyl esters$(L-leucine-OC_n$ : n= 2, 4, 6, 8 and 10) to the gelatin$(EMFSG-C_2,\;EMFSG-C_4,\;EMFSG-C_6,\;EMFSG-C_8,\;EMFSG-C_{10})$ for improving the functional properties such as emulsifying activity, emulsifying viscosity, whippability, electric conductivity, critical micelle concentration and interface tension, etc. Also, the functional properties of the L-leucine alkyl ester modified gelatins were compared with those of Tween-60 as reference. Molecular weights of the enzymatically modified flounder skin gelatin(EMFSG) were 20.5kDa. in $EMFSG-C_2.\;19.5 kDa.\;in\;EMFSG-C_4\;and\;16.5kDa.\;in\;EMFSG-C_6,\;EMFSG-C_8$ and $EMFSG-C_{10}$. respectively. Emulsifying activity and emulsifying viscosity in the modified gelatins were risen with increase of carbon number of the introduced L-leucine alkyl esters. Among the modified gelatins, $EMFSG-C_6$ exhibited the highest emulsifying stability and foaming stability, whereas $EMFSG-C_8$ showed the highest whippability. The electric conductivities of the all $EMFSG-C_n$ were linearly risen to critical micelle concentration(CMC) , therefore $EMFSG-C_{10}$ exhibited the lowest CMC value and interface tension, and dense particles in the microscopic observation. In conclusion, the best quality in functional properties was assured on $EMFSG-C_{10}$.

• Journal of Environmental Science International
• /
• v.9 no.4
• /
• pp.311-318
• /
• 2000

To improve $CO_2$pemselectivity, a modified silica membrane was prepared by chemical vapor deposition with tetraethoxysilane(TEOS)-ethanol-water, and TEOS-ethanol-water-HCI solution at 300-$600^{\circ}C$. The silica was effectively deposited in the mesopores of a ${\gamma}$-alumina film coated on a porous $\alpha$-alumina tube by evacuating the reactants through the porous wall. In this membrane, $CO_2$interacts, to some extent, with the pore wall, and $CO_2$/$N_2$selectivity then exceeds the value of the Knudsen diffusion mechanism, while the membrane derived from TEOS alone has no $CO_2$selectivity. The silica membrane prepared from TEOS-ethanol-water-HCI solution showed that $CO_2$permeance was $2.5$\times$10^{-7}mol/s^{-1}.m^{-2}.Pa^{-1} at 30{\circ}C$ and $CO_2$/$N_2$selectivity was approximately 3. The $CO_2$permeance and selectivity was improved by enlarging the surface diffusion with modification of chemical affinity of the silica pores.

• Journal of the Korean Applied Science and Technology
• /
• v.23 no.3
• /
• pp.264-271
• /
• 2006

PU type flame-retardant coatings (TBAO/L-75, TBAOL ; TBAO/N-100, TBAON) were prepared by blending bromine-containing modified polyester (TBAO) which was synthesized in our earlier work. with two kinds of isocyanate curing agents, Desmodur L-75 and Desmodur N-100. Physical properties of the prepared flame-retardant coatings were tested. TBAOL shows better hardness than TBAON, while TBAON shows better viscosity, accelerated weathering resistance, yellowness index and lightness index difference than TBAOL. There were no remarkable differences in fineness of grind, $60^{\circ}$ specular gloss, cross-hatch adhesion, and abrasion resistance of TBAOL and TBAON. There was no discernable difference in flame-retardancy between the two flame-retardant coatings, TBAOL and TBAON. When the content of tribromo acetic acid, which is flame-retarding component, was 30wt% the LOI value was in a range of $29{\sim}30%$, which indicates that the two coatings are good flame-retardant coatings.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.1512-1519
• /
• 2005

In this study, the potential for liquefaction in the Incheon international airport was calculated by appling the standard penetration test data and laboratory test data to the modified Seed & Idriss(2001) method. The analysis was performed on the non-plastic silty layer and silty sand layer which within the depth of 20m, below 20 of the standard penetration value(N), and the ground water level. Also, each set of data was mapped by using GIS(geographic information systems) and the factor of safety for the potential for liquefaction was obtained by overlapping those layers. As a result, it was found that there exist potential hazard zone for the liquefaction partially. So, the additional detailed assessments for those are thought to be necessary.

• Korean Membrane Journal
• /
• v.4 no.1
• /
• pp.20-24
• /
• 2002

The surface of polysulfone membranes has been modified using the fluorine chemicals, ITFE (2-iodo-1,1,1-trifluoro-ethane F.W.=209.94) and PFPI (1H,1H-pentafluoro-n-propyl iodide F.W.=259.95), and PFI (1H,1H,2H,2H-perfluorohexyl iodide, F.W.=373.99) based on Friedel-Crafts reaction mechanism with varying reaction temperatures, reaction time, and catalysis types. The resulting membranes were characterized through mainly the contact angle measurement and pure water permeability. The smaller reactant shows the larger contact angles. FeBr$_3$ catalyst is more effective than AlCl$_3$. Typically, the PS film treated with ITFE at $25^{\circ}C$ under FeBr$_3$ catalyst showed the contact angle 78.5$^{\circ}C$ which indicated 10% over the value of unreacted PS films. More than 50% of pure water flux 8.0 g/$m^2$hr, reduced at reaction time 10 min relative to the original flux, 3.49 g/$m^2$hr.

• Journal of Korean Society of Water and Wastewater
• /
• v.16 no.6
• /
• pp.670-678
• /
• 2002

Since Korean government imposed a stricter regulation on effluent T-N and T-P concentrations from wastewater treatment plant, a new process has to be developed to meet these rules and this process should remove T-N and T-P, economically, from weak wastewater that is typical for Korea's combined sewer system sewage. In this study, a computer simulator, BioWin from EnviroSim, Inc. was used. Three processes - A2/O, Modified Johannesburg, UCT- had been simulated under same operational conditions and a new process - Parallel BNR Process - had been developed based on these simulation results. The Parallel BNR process consists of two rows of reactors: One row has anaerobic and aerobic reactors in series, and the other row has RAS anoxic1 and RAS anoxic2 reactors in series. In order to ensure anaerobic state in anaerobic tank, a part of influent is fed to RAS anoxic1 tank in second row. This process had been simulated under same conditions of other three processes and the simulation results were compared. The results showed that three existing processes could not perform biological phosphorus removal when the average influent was fed at any operation temperatures. However, the Parallel BNR process was found that biological phosphorus removal could be performed when both design and average influent were fed at any operation temperatures. This process showed the T-N concentration in effluent had a maximum value of 15mg/L when design influent was fed at $13^{\circ}C$ and a minimum value of 14mg/L when average influent was fed at $20^{\circ}C$. Also, T-P concentrations had a maximum value of 1.3mg/L when average influent was fed at $20^{\circ}C$ and a minimum value of 1.1mg/L when design influent was fed at $13^{\circ}C$. Based on these results, we found that this process can remove nitrogen and phosphorus biologically under any operational conditions.

• Journal of Environmental Science International
• /
• v.13 no.9
• /
• pp.807-817
• /
• 2004

The modified biochemical oxygen demand (MBOD) were conducted to evaluate the water quality and fertility in the Mangyeong river from november 2002 to april 2003. MBOD method was used to evaluate algal growth potentials and their limiting factors. MBOD depends on the amount of available inorganic nutrient and organic substrate during 5-day incubation in the dark condition at $20^{\circ}C.$ The MBOD assay depends on inorganic nutrients such as phosphorus and nitrogen as well as reduced carbon as called MBOD, MBOD-P, and MBOD-N, respectively. The concentration of pollutants were in the range of 3.08～48.36 mg/L for COD. The concentration of nutrients were in the range of 0.37～111.62 mg/L for dissolved inorganic nitrogen (DIN) and 0.00～1.03 mg/L for dissolved inorganic phosphorus (DIP). The results of MBOD bioassay showed that the MBOD, MBOD-P and MBOD-N values were 15～173 mg $O_2/L,$ 13～165 mg $O_2/L$ and 66～175 mg $O_2/L$ ranges, respectively. The MBOD values are found to be the highest in Iksan River and the lowest in Hari River throughout the Mangyeong River. The relationships of MBOD, MBOD-P and MBOD-N in MBOD method were generally found in MBOD$\risingdotseq$ MBOD-P$\risingdotseq$MBOD-N. But the result of Gosan was appeared to MBOD$\risingdotseq$MBOD-N > MBOD-P. The MBOD-N value was higher 3 to 5 times than the MBOD-P value in the Gosan station. The algal growth potentials expressed as the concentration of chlorophyll-a were maximum 20 times more than algal biomass in the water column.

• The Korean Journal of Food And Nutrition
• /
• v.19 no.3
• /
• pp.279-287
• /
• 2006

This study was carried out to investigate the influences of modified starches on suppression of retrogradation in Korean rice cake for their optimization, Garaeduk. Based upon studying Avrami equation, the Avrami exponent n value of all the experiment samples was found to be 1.03 ${\sim}$ 1.37 in the influence of modified starches on retrogradation of the rice cake. This means that the retrogradation of the Korean rice cake occurred instantly after the crystallization of starch particles in the Korean rice cake formulated by modified starches. The highest Avrami exponent n value was indicated in the control sample. The rate constant k of retrogradation in the Korean rice cake formulated by modified starches showed comparatively low and appeared to be the lowest in the Korean rice cake formulated by SHPP. This tendency was shown well in the time constant(1/k) of retrogradation velocity. According to the DSC analysis, the onset temperature of gelatinization in thermal characteristics showed somewhat high in case of addition of modified starch into the Korean rice cake on storage time and the SHPP was slowly gone up. In peak temperature of gelatinization in thermal characteristics of the DSC analysis, SSOS and ASA were increased a little in comparison with the control. The control was comparatively high increase. Melting enthalphy of all samples added with modified starches (SSOS: 21.1${\rightarrow}$23.7${\rightarrow}$24.1, ASA: 21.1${\rightarrow}$24.8${\rightarrow}$25.4) appeared to be lower than that of the Korean rice cake without modified starches(21.2${\rightarrow}$26.1${\rightarrow}$27.1). The Korean rice cake added with SHPP was shown to be the lowest in the increasing rate of melting enthalpy(20.9${\rightarrow}$21.4${\rightarrow}$22.1). Heat spreadability of all the samples in Martin melting diameter was revealed to be good in order of control, ASA, SSOS, SHPP and especially the Korean rice cake added with SHPP was shown to be the best in heat spreadability. In color, sensory examination and textural characteristic of the Korean rice cake added with modified starches, the L$^*$value was not changed practically with the storage time and seemed to be stable. The a$^*$ value of the samples was followed by control(2.21${\rightarrow}$5.34: 141.6%), ASA (2.01${\rightarrow}$4.22: 110.0%), SSOS (2.78${\rightarrow}$4.87: 75.2%) and SHPP (2.12${\rightarrow}$3.40: 60.4%) in order of color change. Also the b$^*$ value of the samples was followed by control(4.32${\rightarrow}$6.35: 47.0%), ASA (4.66${\rightarrow}$5.73: 23.0%), SSOS (4.90${\rightarrow}$5.89: 20.2%) and SHPP (4.89${\rightarrow}$5.12: 4.7%) and there was the least (or no) color change with the SHPP. Textural characteristics of samples was shown to be the highest in case of modified starch addition and especially SHPP appeared to be the best in texture.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.10 s.101
• /
• pp.973-981
• /
• 2005

A modified half wavelength loaded line antenna is designed and implemented for mobile terminal applications. The antenna is constructed with a radiating element of half wavelength loaded line structure, dielectric substrate, feeding post and two shorting posts on the experimental PCB. The shorting posts are located at each side of the radiating element and lumped inductance elements are on between each shorting post and ground of PCB. By controlling value of inductors, one can adjust resonant frequency and input impedance respectively. Within inductance value of 12 nH, the antenna can have wide operating range of $1,470\~2,660\;MHz$ and good impedance matching. The measured peak gains are between -0.45 dBi and 2.03 dBi for the operating band.

• Physical Therapy Rehabilitation Science
• /
• v.8 no.2
• /
• pp.74-78
• /
• 2019

Objective: Myofascial release (MFR) is used to restore tissue extensibility of the fascia tissue and is considered to be useful in a number of clinical settings, such as low back pain (LBP). Dynamic myofascial release (DMFR) is the manual therapy, which combined the conventional MFR with the joint mobilization. The purpose of this study was to investigate the effects of the DMFR on trunk mobility, and furthermore, whether the increase of trunk mobility can carry over the improvement of dynamic standing balance in persons with chronic nonspecific LBP. Design: Randomized controlled trial. Methods: Thirty persons with chronic non-specific LBP participated in the study and were randomly assigned to the DMFR group (n=15) or the control group (n=15). DMFR was performed for two sessions (15 minutes/session) per week for four weeks for the treatment group. Both the DMFR and control groups were allowed to perform low-intensity physical activities during the treatment period. The Modified-modified $Sch{\ddot{o}}ber$ test (MMST) for trunk mobility and the Functional Reach Test (FRT) for dynamic standing balance were measured before and after the treatment period in both the DMFR group and the control group. Results: The MMST value of DMFR group increased significantly in all trunk range of motion (flexion, extension, lateral flexion, and rotation) after treatment, compared with the control group (p<0.05). Additionally, the FRT value of the DMFR group improved significantly after treatment, compared with the control group (p<0.05). Conclusions: We suggest that DMFR have a positive effect on trunk mobility and standing balance in persons with chronic LBP.