• Membrane and Water Treatment
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• v.3 no.4
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• pp.243-252
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• 2012

Tri-n-butyl phosphate (TBP) was used as carrier for the transport of Golden yellow and Cibacron LSG dyes through a hexane bulk liquid membrane. The transport efficiency of dyes by TBP was investigated under various experimental conditions such as pH of the feed phase (dyes solution), concentration of the receiving phase (NaOH solution), concentration of TBP in membrane, rate of stirring, effect of transport time, type of solvent, dye concentration in feed phase, effect of temperature.. The maximum transport dyes occurs at ratio of 1:1 TBP-hexane At pH 3.0 0.1 (feed phase) the transport dyes decreased. At high stirring speed (300 rpm) the dyes transport from the feed phase to the strip phase was completed within 60 minutes at $27^{\circ}C$. Under optimum conditions: Feed phase 100 mg/L dyes solution at pH 1.0 0.1, receiving phase 0.1 mol/L NaOH solution, membrane phase 1:1 TBP-hexane , Stirring speed 300 rpm and temperature $27^{\circ}C$, the proposed liquid membrane was applied to recover the textile effluent.

• Journal of Life Science
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• v.20 no.7
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• pp.999-1004
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• 2010

Investigations were carried out on a $\beta$-glucosidase produced by Aspergillus niger under solid-state fermentation conditions as a model of enzyme recovery from fermented wheat bran. The leaching efficiency of distilled water to recover the enzyme from the fermented bran was higher than acetate buffer, citrate buffer, citrate-phosphate buffer and 5% methanol; thus, the conditions were further optimized with distilled water as the extracting agent. After fermented bran was washed three times with distilled water for 1.5 hr each under shaking conditions at 1:5 solid to solvent ratio, a maximum recovery of 0.025 U/g of wheat bran was obtained.

• Analytical Science and Technology
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• v.32 no.3
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• pp.113-119
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• 2019

Enhancement of footwear impressions in urine on the surface of tiles by using p-dimethylaminocinnamaldehyde (DMAC), which react with urea, and ninhydrin, 1,8-diazafluoren-9-one (DFO), 1,2-indanedione/zinc (1,2-IND/Zn), which react with amino acid, was studied. As a result of comparing the application methods of reagents, the ninhydrin and the 1,2-IND/Zn were suitable for application with spray method, which is spray directly on footwear impression, DFO and DMAC were suitable for application with dry contact method, which is applying heat with press to DMAC impregnated paper on footwear impression. In addition, DMAC applied with dry contact method showed best contrast and enhancement result in both white and black colored tiles by comparing of the sensitivity by different dilution ratio of urine and the aging time of footwear impressions in urine. And the result of applied with DMAC (with dry contact method) on the floor tiles collected at various places in a building's men's and women's bathrooms, it can be successfully enhanced that footwear impressions in urine. So it is believed that the method can be used to recover footwear impressions in urine from real crime scenes.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.47-58
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• 2020

Most of the reactor trips in Korean NPPs related to core protection systems were caused not because of proximity of boiling crisis and, consequently, a damage in the core, but due to particular miscalculations or component failures related to the core protection system. The most common core protection system applied in Korean NPPs is the Core Protection Calculator System (CPCS), which is installed in OPR1000 and APR1400 plants. It generates a trip signal to scram the reactor in case of low Departure from Nucleate Boiling Ratio (DNBR) or high Local Power Density (LPD). However, is a reactor trip necessary to protect the core? Or could a fast power reduction be enough to recover the DNBR/LPD without a scram? In order to analyze the online calculation of DNBR/LPD, and the use of fast power reduction as trip avoidance methodology, a concept of CPCS with fast power reduction function was developed in Matlab® Simulink using systems engineering approach. The system was validated with maximum of 0.2% deviation from the reference and the dynamic deviation was maximum of 12.65% for DNBR and 6.72% for LPD during a transient of 16,000 seconds.

• Ocean Systems Engineering
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• v.11 no.4
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• pp.331-351
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• 2021

Underwater images are very much different from images taken on land, due to the presence of a higher disturbance ratio caused by the presence of water medium between the camera and the target object. These distortions and noises result in unclear details and reduced quality of the output image. An underwater image restoration method is proposed in this paper, which uses blurriness information, background light neutralization information, and red-light intensity to estimate depth. The transmission map is then estimated using the derived depth map, by considering separate attenuation coefficients for direct and backscattered signals. The estimated transmission map and estimated background light are then used to recover the scene radiance. Qualitative and quantitative analysis have been used to compare the performance of the proposed method against other state-of-the-art restoration methods. It has been shown that the proposed method can yield good quality restored underwater images. The proposed method has also been evaluated using different qualitative metrics, and results have shown that method is highly capable of restoring underwater images with different conditions. The results are significant and show the applicability of the proposed method for underwater image restoration work.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.345-352
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• 2013

In this paper, a depth estimate method is proposed using GPU(Graphics Processing Unit) in monocular image. a monocular image is a 2D image with missing 3D depth information due to the camera projection and we used a monocular cue to recover the lost depth information by the projection present. The proposed algorithm uses an energy function which takes a variety of cues to create a more generalized and reliable depth map. But, a processing time is late because energy function is defined from the various monocular cues. Therefore, we propose a depth estimate method using GPGPU(General Purpose Graphics Processing Unit). The objective effectiveness of the algorithm is shown using PSNR(Peak Signal to Noise Ratio), a processing time is decrease by 61.22%.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.507-513
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• 1997

To separate and concentrate functional components contained in soybean curd whey, ultrafiltration was performed using regenerated cellulose or polysulphone membrane of spiral-wound type with MWCO 10,000, and the permeate and retentate solutions were analyzed. As the pH of soybean curd whey increased, the permeate flux decreased in both membranes. Treatment of 0.01 M EDTA rather decreased the permeate flux compared with control. The concentration of ionic calcium, which decreased with the pH increase, was thought to affect the permeate flux also. In case of polysulphone membrane, the permeate was efficiently purified and the retentate protein was concentrated significantly in which the membrane rejection value (MRV) for chemical oxygen demand (COD) was 79.25% and that of protein was 98.42% at the volume concentration ratio (VCR) of 10. MRV of the protein of regenerated cellulose membrane was lower than that of polysulphone membrane. To recover oligosaccharides to the permeate solution and increase the content of raffinose and stachyose, regenerated cellulose membrane was more suitable than polysulphone membrane and the optimum VCR was 4.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.683-687
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• 2009

A method for depolymerization of PET by catalyzed glycolysis with an excess ethylene glycol(EG) to recover bis-hydroxyethyl terephthalate(BHET) was investigated. The product was analyzed by high-performance liquid chromatography(HPLC). Effects of operation variables such as reaction temperature, reaction time, EG/PET weight ratio were examined and kinetics of the glycolysis was studied. High temperature increases the rate of depolymerization and the yield of BHET. But, repolymerization rate was also high at too high temperature and the yield at $250^{\circ}C$ was shown to be lower than that at $230^{\circ}C$. First order reaction model was proposed to describe the glycolysis reaction. Activation energies for the reaction were obtained to be 37.8 kJ/mol above $210^{\circ}C$ and 149.6 kJ/mol below $210^{\circ}C$, which shows the glycolysis reaction is a multiple reaction. A maximum yield of BHET of 71% was achieved at a reaction temperature of $230^{\circ}C$ for 6 hr with an EG/PET weight ratio 4.

• Resources Recycling
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• v.12 no.6
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• pp.47-56
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• 2003

PVC(polyvinyl chloride) powder were mixed with EAF(Electric Arc Furnace) dust and made as pellets. In order to recover the hydrochloride emitted from pyrolysis of PVC and the valuable metals in dust through making chlorides, pellets were roasted at $300 ^{\circ}C$ and investigated about the generation of chlorides. Two dust samples were collected at I steel making Co. and P Co. (called I dust and P dust respectively), which were mainly composed of zincite and franklinite. It was confirmed that about 50% of Zn in I dust and 48% of Zn in P dust compose zincite. The emission of HCl gas was completed in 15 min at 30$0^{\circ}C$ and the HCl mostly reacted with dust and made chlorides under 20% PVC mixed ratio. Because the reaction of HCl with zincite was faster than with franklinit, when generation and volatilization of ferric chloride is not allowed, the equivalent PVC powder mixed ratio in pellet depended on the amount of zincite in dust.

• Journal of IKEEE
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• v.20 no.4
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• pp.432-434
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• 2016

In conventional SIDO(Single Inductor Dual Output) boost converter, charging time is changed by load power consumption. In this case, if the power consumption of one load is changed to such a degree that switching frequency of the boost converter must be changed, another load charge time is also changed, which this causes cross regulation. In this paper, the charge copy technique is proposed to reduce cross regulation. When the switching frequency is changed to an integer ratio, another load charge time is also changed to integer ratio. Simulation result shows that proposed method reduces the 10.24mV cross regulation and 39.118us recover-time compared with conventional method.