• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.101-108
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• 2002

Benthic organisms dwell in sediment-water interface that contains significant amount of organic and inorganic contaminants. Their feeding behavior is highly related with sediment itself and pore water in the sediments, especially in ease of deposit feeder (i.e. polychaete, amphipod). The acid volatile sulfide (AVS) is one of the important binding phases of sediment-bound metals in addition to organic matter and Fe and Mn oxide fractions in sediments, particularly in anoxic sediments. The AVS model is a powerful tool to predict metal bioavailability and bioaccumulation in benthic organisms considering SEM/AVS mole ratios in surficial sediments. However, several biogeochemical factors must be considered to use AVS model in the sediment-bound metal bioavailability.

• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.168-175
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• 2015

This study was conducted in autumn to determine phosphorus (P) fraction in sediments of Daechung Lake, to elucidate controlling factors for sedimentary P, and to compare with the other areas. For this study, sediment samples were collected at 6 sites only once on November 2014 using ponar grab and analyzed for solid-phase P (Loosely adsorbed, Fe-bound, Al-bound, detrital apatite, and refractory organic P) by sequential extraction. Total phosphorus (TP) was relatively high in front of Daechung Dam and Hoinam where fish farm was run until 1997. The dominant sedimentary P form was Al-bound P, followed by Fe-bound P, which could be released from sediment to water column during suboxic state. Based on principal component analysis, Al-bound P, Fe-bound, and TP were controlled by grain size of sediments. Loosely adsorbed, detrital apatite, and refractory organic P were relatively highly accumulated at the mouth of major tributaries where suspended sediments were delivered. Sedimentary P concentrations in Daechung Lake sediments were not higher than in other lake sediments. Therefore, based on these results, major controlling factors were grain size and input of suspended sediments from tributaries.

• Elastomers and Composites
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• v.54 no.4
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• pp.359-367
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• 2019

Poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels modified with various co-monomers, such as N-vinyl pyrrolidone (NVP), glycidyl methacrylate (GMA), and glycerol monomethacrylate (GMMA), were prepared to investigate the effect of adding a co-monomer on the water contents, surface wettability, and tensile modulus. These polymers were synthesized by thermal- and photo-polymerization in the presence of azobisisobutyronitrile (AIBN) and diphenyl(2,4,6-trimethylbenzoyl)-phosphineoxide (TPO) as the initiators. The characteristics of the hydrogels were analyzed via FTIR and UV/Vis spectroscopies, contact angle measurements, and tensile modulus measurements with UTM. Regarding the properties of water in the hydrogels, the ratio between free to bound water was investigated using differential scanning calorimetry (DSC). The effects of adding the co-monomers on the water content, surface wettability, and tensile modulus for soft contact lenses were also investigated. In the case of p(HEMA-co-NVP) hydrogels, the increase in the equilibrium water content (EWC) was primarily due to the increase in the bound water content. For p(HEMA-co-GMMA) hydrogels, an increase in free water content was the main reason for the increased EWC. In contrast, in the case of p(HEMA-co-GMA) hydrogels, a decrease in bound water content was observed to be the main factor that reduced the EWC. Photo-polymerized PHEMA hydrogels showed enhanced surface wettability and tensile modulus as compared to those produced via thermal polymerization.

• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.789-795
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• 2002

To evaluate the bind rate and behavior of two types chloride ion-one is the chloride ion added in mixture when un-washed sea sand is used as fine aggregate, one is the chloride ion admitted in the new version of concrete standard specification, pore solution extracted in cement paste were analyzed. The results are follow. 1 As passing the time, the chloride concentration in the pore solution decreases with the Increase in the chloride content absorbed by the hydrate products. As compared with chloride contents in mixing water, the bound ratio of chloride at 49 days is 64∼90％. 2. The bound ratio of chloride in cement paste considering evaporable water as pore solution is obtained. In case of Pl∼P3(added chloride content wt of cement 0.046∼0.16 ％), the bound ratio of chloride is 91.8∼93.5 ％. P4(added chloride wt of cement 0.3％) is 89.1％, but P5(added chloride wt of cement 0.617％) bound is only 77％. 3. The bound ratio of chloride to wt of cement is 0.015∼0.475％ with adding chloride. In case chloride added over 0.091 ％ wt of cement, the bound chloride content increases 1.7∼1.8 times in spite of added chloride increase twice. The bound ratio of chloride to wt of cement decreased with the increase in the chloride content. 4. The more increase added chloride content, the more increase the bound ration of chloride. But the absolute value of chloride content in pore solution increased.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.218-218
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• 2003

Recently we showed the prototype portable device for the determination of human skin moisture by using near infrared spectroscopy. In order to optimize the acquiring condition of NIR spectrum of skin and control the target information of water depending the site such as epidermis and dermis, skin depth profiling was investigated changing the distance between illuminations and receiving of radiation in the terminal of fiber probe. The colleted light information could be controlled by changing the distance of the fiber optic probes. It was confirmed that the longer distance we used, the deeper site from the skin surface we could get information from in this study. Four kinds of probes with distances such as 0.03 mm, 0.1 mm, 0.5 mm, and 1.0 mm were used. In addition, the gap size from 0.3 mm to 3.0 mm was studied to control the intensity of water absorbance effectively and to avoid saturation of water absorption. We also investigated the reference materials depending the reflectance ratio for water absorption not to be saturated because of the strong absorptivity of water. Furthermore, spectroscopic information regarding free water and bound water around 1850 nm was investigated by using the different distance of fiber optic probes. This study would be great help to control the spectroscopic information of water to be measured depending the site where water exists.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.169-174
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• 2008

In this study a trickling filter system was developed by using polypropylene media and polypropylene nylon media that has recently been developed. The experiment analyzed an ability of water purification of the two plastic media and the effects of biomass on the final effluent. As recycling ratio increases, polypropylene nylon suspender showed higher efficiency by 20%; and, when media height was lengthened twice, efficiency increased about 10%. EPS and biomass increased in proportion to the increase of recycling ratio, and bound-TOC showed a similar trend with bound-EPS (extra-cellular polymeric substances) concentration.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.423-428
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• 1996

Optimum conditions for hydrolysis were investigated to enhance water-solubilities of protein-bound polysaccharides in the basidiocarps of Ganoderma lucidum by treating chymotrypsin. We also attempted with Ganoderma lucidum residue remaining after extracting hot water-soluble compoents in Ganoderma lucidum. After hydrolyzing under optimum conditions (20 ppm chymotrypsin, 2% Gampderma lucidum or 6% Ganoderma lucidum residue, at pH 10 and at $ 40^{\circ}C$), the amounts of total protein and carbohydrate of hydrolysate were measured. Michaelis constant, $K_{m}$, and maximum rate, $V_{max}$, calculated by Lineweaver-Buck plot for the hydrolysis of Ganoderma lucidum were 1.73% and 0.073%/min respectively and those for hydrolysis of Ganoderma lucidum residue were 2.40% and 0.033%/min respectively. The amount of polysaccharide isolated from Ganoderma lucidum (100 g) treated with chymotrypsin was only 3.07 g, but significantly increased amount (14.34 g) of polysaccharides was isolated from Ganoderma lucidum residue (100 g) treated with chymotrypsin. The protein-bound polysaccharide was isolated from the non-hydrolyzed and hydrolyzed sample and molecular weights of the polysaccharide were measured by Sepharose CL-48 gel filtration.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.503-508
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• 1997

The extraction and separation methods of protein-bound polysaccharides from the mycelium and culture broth of L. edodes were investigated. The use 2% solution of surface active agent, Triton X-100 was effective for extraction of the protein-bound polysaccharide from the mycelium. The extraction of the protein-bound polysaccharides from mycelium with hot water was achieved by 4 hours extraction at 10$0^{\circ}C$. For the separation and partial purification of the protein bound polysaccharides the column chromatography using DEAE-Cellulose, DEAE-Sephadex and Sephadex proved to be effective.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.125-131
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• 1993

The state of water in various modified cellulose membranes such as [carboxymethyl cellulose(CMC)-gelatin] polyelectrolyte complex, methylcellulose(MC) grafted with acrylic acid(AA), [(MC-g-AA)-gelatin] polyelectrolyte complex, were determined by differential scanning calorimetric technique. The amounts of freezing(free) and nonfreezing(bound) water were estimated to determine the permeability coefficient of solutes through membranes. The state of water in membranes were influenced by the states of the composition, morphology, and their water content. The difference in diffusive permeability through the water-swollen membranes can be explained by the difference in the free and bound water content.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.159-166
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• 1999

Purpose : To evaluate the effect of rotational correlation time (${\tau}_R$) and the possible related changes of other parameters, ${\tau}_M,{\;}{\tau}_S,{\;}and{\;}(\tau}_V$ of gadolinium (Gd) chelate on T1 relaxation enhancement in two pool model. Materials and Methods : The NMRD (Nuclear Magnetic Relaxation Dispersion) profiles were simulated from 0.02 MHz to 800 MHz proton Larmor frequency for different values of rotational correlation times based on Solomon-Bloembergen equation for inner-sphere relaxation enhancement. To include both unbound pool (pool A) and bound pool (pool B), the relaxivity was divided by contribution from unbound pool and bound pool. The rotational correlation time for pool A was fixed at the value of 0.1 ns, which is a typical value for low molecular weight complexes such as Gd-DTPA in solution and ${\tau}_R$ for pool B was changed from 0.1 ns to 20 ns to allow the slower rotation by binding to macromolecule. The fractional factor of was also adjusted from 0 to 1.0 to simulate different binding ratios to macromolecule. Since the binding of Gd-chelate to macromolecule cab alter the electronic environment of Gd ion and also the degree of bulk water access to hydration site of Gd-chelate, the effects of these parameters were also included. Results : The result shows that low field profiles, ranged from 0.02 to 40 MHz, and dominated by contribution from bound pool, which is bound to macromolecule regardless of binding ratios. In addition, as more Gd-chelate bound to macromolecule, sharp increase of relaxivity at higher field occurs. The NMRD profiles for different values of ${\tau}_S$ show the enormous increase of low field profile whereas relaxivity at high field is not affected by ${\tau}_S$. On the other hand, the change in ${\tau}$V does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field and the maximum relaxivity value. The results shows a parabolic dependence of relaxivity on ${\tau}_M$. Conclusion : Binding of Gd-chelate to a macromolecule causes slower rotational tumbling of Gd-chelate and would result in relaxation enhancement, especially in clinical imaging field. However, binding to macromolecule can change water enchange rate (${\tau}_M$) and electronic relaxation ($T_le$) vis structural deformation of electron environment and the access of bulk water to hydration site of metal-chelate. The clinical utilities of Gd-chelate bound to macromolecule are the less dose requirement, the tissue specificity, and the better perfusion and intravascular agents.