• Clean Technology
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• v.23 no.2
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• pp.196-204
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• 2017

CdZnS/ZnO composite was prepared through low-temperature precipitation and drying method. The property of CdZnS/ZnO as a recyclable photocatalyst for the degradation of rhodamine B (RhB) under visible light irradiation was examined. The sample was characterized by XRD, FE-SEM, XPS, UV-vis DRS and photoluminescence techniques before and after repeated reaction to investigate the change of properties during the photocatalytic reaction. During repeated reaction, the CdZnS/ZnO showed an improved photocatalytic activity and recycle stability. Among two feasible reaction pathways for photocatalytic degradation of RhB, the cleavage of conjugated chromophore was found to predominate over N-dealkylation of chromophore skeleton in the present work. The results indicate that the CdZnS/ZnO, prepared by a simple precipitation method, can be used as a visible-light driven photocatalyst with enhanced cycle stability and activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.981-986
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• 2000

In the process of tuna for food, the unprocessed parts of the whole fish range from 30 to 35%, which are mostly used as animal feed stuff, and wasted. Thus, preliminary study on the recycling of the by-product was done to ultimately produce highly valuable products. The study was peformed on skin, skin flesh, tail flesh, dark flesh and abdominal flesh of the tuna. First, crude protein was the most abundant in the skin at 26.31%. About 21% of the crude protein were found in the other samples. Second, crude fat was greatly obtained in the skin at 15.58%. Interestingly, only 0.75% of crude fat was found in the dark flesh. Third, vitamin C and vitamin B group were highly measured in the abdominal flesh and the dark flesh, respectively. Importantly, docosahexaenoic acid (DHA, C22 : 6 $\omega$ -3) and eicosapentaenoic acid (EPA, C22 : 6 $\omega$ -3) which are highly unsaturated fatty acids, were abundant in the skin and skin flesh. To determine the effect of high temperature to the unprocessed parts, the samples were exposed to steam for 30 min. After this processing, 15-methylhexadecanoic acid (i-17 : 0) were in- creased in the skin flesh and the dark flesh. Furthermore, 3-hydroxytetradecanoic acid (3-OH 14 : 0), heptadecanoic acid (17 : 0), 2-hydroxyhexadecanoic acid (2-OH 16 : 0) and nonadecanoic acid (19 : 0) hat were not found before with steam were detected. The DHA and EPA in the dark flesh and the DHA in the skin were stable, respectively, even after the treatment.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.363-370
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• 2016

Lightweight geopolymers are more readily produced and give higher fire resistant performance than foam cement concrete. Lowering the density of solid geopolymers can be achieved by inducing chemical reactions that entrain gases to foam the geopolymer structure. This paper reports on the effects of adding different concentrations of aluminum powder on the properties of cellular structured geopolymers. The apparent density of lightweight geopolymers has a range from 0.7 to $1.2g/m^3$ with 0.025, 0.05 and 0.10 wt% of a foaming agent concentration, which corresponds to about 37~60 % of the apparent density, $1.96g/cm^3$, of solid geopolymers. The compressive strength of cellular structured geopolymers decreased to 6~18 % of the compressive strength, 45 MPa of solid geopolymers. The microstructure of geopolymers gel was equivalent for both solid and cellular structured geopolymers. The workability of geopolymers with polyprophylene fibers needs to be improved as in fiber-reinforced cement concrete. The lightweight geopolymers could be used as indoor wall tile or board due to fire resistance and incombustibility of geopolymers.

• Elastomers and Composites
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• v.48 no.1
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• pp.67-75
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• 2013

E-TPE (Engineering Thermoplastic Polyether Ester) was Ester Elastomer with functional groups as recycling and fast processability. In addition, if the car's lightweight enough to highlight eco-friendly materials that help to improve fuel economy has become. Have all the attributes of the rubber and engineering plastics E-TPE the available temperature area is spacious, heat resistance and oil resistance is excellent but getting attention as a new material in the field of auto parts in the field of electrical and electronic domestic depends entirely on imports by the lack of core technology and has been research and development is urgently needed. In this study, the hard segments, polyester (TPEE) as the base soft elastomers of the segments Ethylen-prophylene-Copolymer and CSM (Choloro sulphonated polyethylene Rubber), VAMAC (Ethylene Acrylic Rubber), NBR (Acrylonitrin Butadiene Rubber), 1, 3-Phenylene-bisoxazoline is dealing with Dynamic Vulcanized by content and added rubber properties, thermal variation observed. As a result, the properties of the dynamic vulcanization with NBR compared to other rubber heat resistance and oil resistance is on the increase.

• Journal of Life Science
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• v.23 no.12
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• pp.1471-1476
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• 2013

The present study deals with the immobilization of Kluyveromyces lactis ${\beta}$-galactosidase on a weak ionic exchange resin (Duolite A568) as polymer support. ${\beta}$-Galactosidase was immobilized using the adsorption method. A kinetic study of the immobilized enzyme was performed in a packed-bed reactor. The adsorption of the enzyme followed a typical Freundlich adsorption isotherm. The adsorption parameters of k and n were 14.6 and 1.74, respectively. The initial rates method was used to characterize the kinetic parameters of the free and immobilized enzymes. The Michaelis-Menten constant ($K_m$) for the immobilized enzyme (120 mM) was higher than it was for the free enzyme (79 mM). The effect of competitive inhibition kinetics was studied by changing the concentration of galactose in a recycling packed-bed reactor. The kinetic model with competitive inhibition by galactose was best fitted to the experimental results with $V_m$, $K_m$, and $K_I$ values of 46.3 $mmolmin^{-1}mg^{-1}$, 120 mM, and 24.4 mM, respectively. In a continuous packed-bed reactor, increasing the flow rate of the lactose solution decreased the conversion efficiency of lactose at different input lactose concentrations. Continuous operation of 11 days was conducted to investigate the stability of a long-term operation. The retained activity of the immobilized enzymes was 63% and the half-life of the immobilized enzyme was found to be 15 days.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.175-180
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• 2016

Waste bumpers from out-of-service vehicles are recycled in the manufacturing process of plastic parts by incorporating pristine materials after removing the coated paint on a bumper. This study examined the chemical properties and mechanical properties of a mixture of recycled bumper and pristine materials as a function of the mixing ratio. When the pristine materials and the recycled bumper pieces were mixed, the stiffness (tensile strength and the flexural modulus) was provided by their composition averages. On the other hand, the toughness (Izod impact strength and the elongation-at-break) was lower than their composition averages (i.e., negative deviation). FTIR analysis showed that these results were due to the absence of the compatibility between the pristine materials and recycled bumper pieces. When the recycled bumper pieces were loaded at more than 30 wt. %, the toughness decreased drastically. A previous study showed that a paint removal efficiency up to 80 wt.% was easily attainable. The other 20 wt.% of paint on the bumper is very difficult to remove. Therefore, this study examined the mechanical properties of a mixture of recycled bumper pieces containing the unremoved paint and recycled bumper pieces without paint. When the recycled bumper pieces containing the unremoved paint were incorporated in only small quantities, the mechanical properties were decreased to a great extent. These results show that the paint removal efficiency is very important in the recycled bumper industry.

• Journal of Dairy Science and Biotechnology
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• v.35 no.4
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• pp.244-248
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• 2017

The effects of ultrasonic (1.2~1.7 kJ/g TS) pretreatment on the solubilization of dairy and livestock sludge were separately evaluated to investigate the possibility of recycling dairy sludge as a potential source of organic carbon. Compared to other industrial wastewater and sewage sludge, dairy sludge has higher organic matter content and no toxic materials. The solubilization rates of dairy and livestock sludge, at a specific energy input of 1.7 kJ/g TS, were 14.5% and 10.6%, respectively. After the 90-minute ultrasonic treatment, the soluble COD (chemical oxygen demand) increased about 7.1 times that of the initial SCOD, at an increase rate of $0.022m^{-1}$. In comparison, the increase in soluble nitrogen, which was ~3.4 times that of the initial soluble nitrogen concentration, was much smaller than the increase in SCOD; thus, the C/N ratio increased from 4.0 to 8.7.

• Korean Journal of Materials Research
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• v.6 no.8
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• pp.761-767
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• 1996

The composite fiber adsorbents containing amidoxime group were prepared and separation properties of uranium ion from seawater were investigated. The amount of uranium adsorption was increased with an increase in adsorption time. When the mole ratio of monomer and comonomer, such as acrylonitrile (AN), tetraethyleneglycol dimethacrylate(TEGMA), and divinylbenzene (DVB), were 1 :0. 1 :0.003, this resin showed the maximum adsorption ability for uranium at a level of pH 8. The amount of uranium adsorption was also increased linearly to one hour with an increase in the content of adsorbent which was added in the composite fiber adsorbents(CFA). The maximum adsorption for uranium of CF A showed at $25^{\circ}C$. Hence, the adsorption ability of CF A for calcium and magnecium ions were increased gradually by the recycling of adsorption and disorption, the adsorption content of their on were 0.3, 0.9mmole/g-adsorbents, respectly. It also showed that the adsorption contents of Ca and \1g ions were much lower than them of uranium. The desorption of uranium on the CF A was carried out , bout 100% within 30min, and the desorption rate of various CF A were equalled.

• Herbal Formula Science
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• v.29 no.4
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• pp.239-252
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• 2021

Objectives : This study is to effect of improving muscle atrophy through water extract on the solid-phase fermentation extraction with Phellinus linteus of discarded Schisandra chinensis in an atorvastatin-induced atrophy C2C12 cell. Methods : C2C12 myoblast were differentiated into myotube by 2% horse serum medium for 6 days, and then treated solid-phase fermentation(S-P) extract at different concentrations for 24h. To investigate the effect of S-P extract on the induction of muscle atrophy and expression of atrophy-related genes and apoptosis in differentiated C2C12 myotubes using a GSH, ROS, real-time PCR, western blots analysis. Results : As a result of treatment with atorvastatin at concentrations of 5, 10, and 20 uM on the 6th day of differentiation in C2C12 myotube cells, it was confirmed that the cell morphology was damaged in a concentration-dependent manner, and the length and thickness of the myotube also decreased in a concentration-dependent manner. Treatment with S-P extract (50, 100 and 200 ㎍/㎖) increased of GSH and inhibited ROS in the atorvastatin-induced muscle atrophy cell model at a concentration that did not induce toxicity. In addition, it was confirmed that it has an effect on muscle reduction by inhibiting apoptosis of muscle cells as well as being involved in protein production and degradation of muscle cells. Conclusions : Atorvastatin-induced atrophy C2C12 cell, S-P extract activates related to differentiation/generation and proteolysis, and inhibits cell death of atrophy in C2C12 cell. Based on this, it is necessary to prove its effectiveness through animal models and human application test, but it is considered to be discarded Schisandra chinensis can present the potential for development as a recycling industrial material.

• Journal of Adhesion and Interface
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• v.22 no.1
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• pp.1-7
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• 2021

The importance of high capacity energy storage devices has recently emerged for stable power supply through renewable energy generation. From this point of view, the Na-air battery (NAB), which is a next-generation secondary battery, is receiving huge attention because it can realize a high capacity through abundant and inexpensive raw materials. In this study, activated carbon-based catalysts for hybrid type Na-air batteries were prepared and their characteristics were compared and analysed. In particular, from the viewpoint of resource recycling, activated carbon (Orange-C) was prepared using discarded orange peel, and performance was compared with Vulcan carbon, which is widely used. In addition, a Pt/C catalyst (homemade-Pt/C, HM-Pt/C) was synthesized using a modified polyol method to check whether the prepared activated carbon can be used as a supported catalyst, and a commercial Pt/C catalyst (Commercial Pt/C) and electrochemical performance were compared. The prepared Orange-C exhibited a typical H3 type BET isotherm, which is evidence that micropore and mesopore exist. In addition, in the case of HM-Pt/C, it was confirmed through TEM analysis that Pt particles were evenly distributed on the activated carbon supported catalyst. In particular, the HM-Pt/C-based NAB showed the smallest voltage gap (0.224V) and good voltage efficiency (92.34%) in the 1st galvanostatic charge-discharge test. In addition, the cycle performance test conducted for 20 cycles showed the most stable performance.