• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.3
• /
• pp.195-203
• /
• 2012

In this study, The effects of three different biological activated carbon (BAC) materials (each coal, coconut and wood based activated carbons) and anthracite, empty bed contact time (EBCT) and water temperature on the removal of MK, HHCB and AHTN in BAC filters were investigated. Experiments were conducted at three water temperatures (5, 15 and $25^{\circ}C$) and four EBCTs (5, 10, 15 and 20 min). The results indicated that coal based BAC retained more attached bacterial biomass on the surface of the activated carbon than the other BAC, increasing EBCT or increasing water temperature increased the synthetic musk compounds (SMCs) removal in BAC columns. The kinetic analysis suggested a first-order reaction model for MK, HHCB and AHTN removal at various water temperatures (5, 15 and $25^{\circ}C$). The pseudo-first-order biodegradation rate constants and half-lives were also calculated for MK, HHCB and AHTN removal at 5, 15 and $25^{\circ}C$. The pseudo-first-order biodegradation rate constants and half-lives of MK, HHCB and AHTN ranging from 0.0082 $min^{-1}$ to 0.4452 $min^{-1}$ and from 1.56 min to 84.51 min could be used to assist water utilities in designing and operating BAC filters for SMCs removal.

• Korean Journal of Medicinal Crop Science
• /
• v.23 no.4
• /
• pp.292-297
• /
• 2015

This study was carried out to have the basic and applied informations relating to develop the cultivation methods and to increase the productivity and quality of ginseng. 1 to 6 year old ginsengs of Jakyung cultivar were cultivated and the content and synthetic amount of carbohydrates were investigated with different plant tissues, growth stages, and years old. The concentration of total carbohydrates at six year old ginseng including water soluble and water insoluble carbohydrates was about 18.9%, 42.9%, and 43,6% in leaves, tap roots, and lateral roots, respectively. Water soluble carbohydrate of tap and lateral roots was slightly decreased from August until September, and then increased on November, whereas its water insoluble carbohydrate was increased from August to September and then decreased on November. Comparing with the content of carbohydrates of 1 to 6 year old ginsengs, it was continuously increased from one year old ginseng until five year old ginseng, however it was not increased much in six year old ginseng. The highest content of carbohydrates was at five year-old in all tissues of ginseng. Water soluble and water insoluble carbohydrates were significantly shown different in leaves, stems, tap roots, and lateral root at different growth stages and with different years old. The content of water soluble carbohydrate in the leaves was remarkedly higher compared to that of water insoluble carbohydrate, while in the root the content of water insoluble carbohydrate was clearly higher compared to the water soluble carbohydrate. Comparing with the synthetic amount of carbohydrates, water soluble carbohydrates was higher in the shoot than that in the root, whereas water-insoluble carbohydrates higher in the root than that in the shoot. Carbohydrates which would be utilized in ginseng tissues for short and long-term periods as major energy were appeared differently in between shoot and root, with different growth stages, and years old.

• Analytical Science and Technology
• /
• v.34 no.4
• /
• pp.160-171
• /
• 2021

Synthetic azo dyes are used extensively in herbal medicines to render the medicines more visually attractive to consumers. This study developed and validated a rapid high-performance liquid chromatography (HPLC) method to determine whether synthetic colorants such as Tartrazine, Auramine O, Metanil yellow, Sunset yellow, and Orange II are used extensively in Typha orientalis. To increase the recovery of the synthetic dyes, this method employed containing 50 mM ammonium acetate in 70 % methanol at first extraction and 100 mM HCl in 70 % methanol at second extraction. Five synthetic pigments in Typha orientalis were separated by gradient elution with a mobile phase consisting of acetonitrile and 50 mM ammonium acetate in distilled water at ultra-violet (UV) detection 428 nm or 500 nm. Additionally, this study established the liquid chromatography tandem mass spectrometry (LC-MS/MS) method to confirm positive samples suspected by HPLC results. The HPLC-UV method had good linearity, indicating r²> 0.999. The recoveries of the samples spiked with three different concentration ranged from 73.8~91.5 %, and relative standard deviation values indicated 0.2~5.2 %. The established LC-MS/MS could successfully identify the synthetic pigments in herbal medicine samples. The study demonstrates that Typha orientalis adulterated by yellowish synthetic dyes can be successfully distinguished when using the HPLC-UV method.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.6
• /
• pp.785-793
• /
• 2004

Coagulation has been investigated for pretreatment of low-pressure membrane systems such as microfiltration and ultrafiltration. Coagulation pretreatment can reduce foulants (particles and organic matter) prior to membrane filtration. However, when in-line coagulation or submerged type of filtration is used, flocculent aggregates could act as a foulant depending on concentrations and specific properties of floc. A natural water and three synthetic waters were used to investigate effects of coagulation pretreatment and presence of flocculent aggregates on membrane fouling. Coagulation pretreatment shows that foul ants were effectively removed during coagulation and the formed cake layer on the membrane surface had less resistances compared to raw natural water. In addition, little difference in membrane fouling was found by flocculent aggregates from the natural water. Interestingly, however, the results by three synthetic waters indicated that flocculent aggregates could have adverse effects on membrane fouling in a specific condition.

• Textile Coloration and Finishing
• /
• v.26 no.2
• /
• pp.131-142
• /
• 2014

This paper was focused on investigating synthetic fabrics treated with persimmon juice by padding mangle repeatedly. The merit of dyeing by pad-dry method was easier color reproduction than dyeing by immersion method. With increasing number of padding, the dyed nylon fabrics showed deeper yellow-red colors, but dyed polyester fabrics had no uniform tendency. The dyed synthetic fabrics had a 3rd grade of ligtht, 4~5th grade of perspiration fastness, 5th grade of stain washing fastness, and 3~5th grade of rubbing fastness. As the number of padding and exposed time to sunlight or UV light increase, the value of K/S and ${\Delta}E$ increased and the colors become much deeper gradually. The color development had completed about 70 hours exposure to UV light. As the padding time of dyeing with persimmon juice increased, stiffness and water repellent property were enhanced, respectively. Also, the dyed synthetic fabrics had good antibacterial activity and deodorization.

• The Journal of Korea Robotics Society
• /
• v.14 no.2
• /
• pp.139-149
• /
• 2019

In this paper, we present auto-annotation tool and synthetic dataset using 3D CAD model for deep learning based object detection. To be used as training data for deep learning methods, class, segmentation, bounding-box, contour, and pose annotations of the object are needed. We propose an automated annotation tool and synthetic image generation. Our resulting synthetic dataset reflects occlusion between objects and applicable for both underwater and in-air environments. To verify our synthetic dataset, we use MASK R-CNN as a state-of-the-art method among object detection model using deep learning. For experiment, we make the experimental environment reflecting the actual underwater environment. We show that object detection model trained via our dataset show significantly accurate results and robustness for the underwater environment. Lastly, we verify that our synthetic dataset is suitable for deep learning model for the underwater environments.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.8
• /
• pp.44-57
• /
• 2001

This paper analyses the performance of FFTSA (Fast Fourier Transform Synthetic Aperture) in the effects of temporal coherence and oscillatory towed course, which is one of the techniques for passive synthetic aperture SONAR process using linearly distributed towed array. Also this paper proposes the FFTSA technique using towed array having conformal shape to alleviate the performance degradation for estimating the incident angle under inconsistent under water environments. And this paper analyses the performance of the proposed FFTSA technique making use of conformal structure throughout exhaustive computer simulations.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.4
• /
• pp.579-589
• /
• 2012

To reduce extensive energy costs of the internal recycling for the purpose of denitrification in the advanced wastewater treatment, a post-treatment process using an electro-coagulation to treat nitrate in the secondary effluents is evaluated in this study. Removals of phosphorus and organics in the secondary effluents by the electro-coagulation were also evaluated to propose an alternative advanced wastewatert treatment process. A series of experiments of the electro-coagulation were carried out with the following 4 different samples: synthetic solution containing nitrate only, synthetic solution containing nitrate as well as phosphorus, secondary effluents from activated sludge cultivated in laboratory, and secondary effluents from real wastewater treatment plants. Removals of nitrate and phosphorus in the synthetic solution were 30 and 97 % respectively, which verified the feasibility of the process. Removals of nitrate, phosphorus and COD in the secondary effluents from the cultivated sludge in laboratory were 49, 90 and 19 % respectively. Removal efficiency of the total nitrogen, nitrrate, phosphorus and COD in the secondary effluent from real wastewater treatment plant were 50, 61, 98 and 80 % respectively. The removal of the total nitrogen was less than the nitrate as expected, which is due to the formation of ammonia nitrogen in the cathode. But the proposed scheme could be an energy saving and alternative process for the advanced wastewater treatment if further studies for the process optimization are carried out.

• Journal of Food Hygiene and Safety
• /
• v.13 no.4
• /
• pp.344-354
• /
• 1998

This study was conducted to evaluate the MSPD and HPLC method about simultaneous determination for residual synthetic antimicrobials of sixteen species such as sulfonamide etc. in livestock products. Elution solvent used in HPLC was ethylacetate:acetonitrile (4:1), and mobile phases for solvent A and B were water:methanol:acetonit rile:phosphric acid (700:250:50:0.2) and 100% acetonitrile respectively. The detector and absorbency used in HPLC was UV 266 nm. This study showed the reduction effect of 99.1% for organic solvents, 94% for experimental steps, 95% for analytical time and manpower and 98.9% for costs compared with korea food standard method. The average recovery rates for chicken, bovine, pork and milk were 67.7% 96.2%, 67.7%~96.6%, 70.0%~96.2%, and 13.8%~97.8%.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.4
• /
• pp.431-438
• /
• 2009

The purpose of this study was to evaluate the performances of zero-valent iron (ZVI) combined SBR (Z-SBR) process in decolorization and organic removal of synthetic dye wastewater. The batch test for optimizing the operation parameters of ZVI column showed that the appropriate EBCT was around 11 min and the pH of the dye wastewater was below 7.0. During the step increase of influent color unit from 300 to 1,000cu, about 53 to 79% decolorization efficiency could be achieved in control SBR (C-SBR, without ZVI column), which resulted from destroying azo bond of synthetic dye in anaerobic condition. For the same influent color loading, Z-SBR showed always higher decolorization efficiency than C-SBR with an aid of ZVI reducing power. The TCOD concentration in Z-SBR effluent was 20-30mg/L lower than C-SBR effluent although the TCOD before and after ZVI column was nearly same. It means that breakdown of azo bond by ZVI reducing power could increase biodegradability of synthetic dye wastewater.