• Journal of Wetlands Research
• /
• v.18 no.3
• /
• pp.286-291
• /
• 2016

This study was carried out to evaluate the feasibility of air-stripping by DIWS(Dip Injection Wet Scrubber) system on high concentration of ammonia wastewater more than 10,000 mg/L. In the case of changing temperature from $30^{\circ}C$ to $70^{\circ}C$ maintaining pH 12.5 within the 72 hours, the removal efficiency of T-N by the present treatment plant was increased to 90.5% which was initially kept 70.3%. Although the high concentration of T-N with 9,120~12,955 mg/L was treated by micro-bubble through DIWS system maintaining the temperature of $30^{\circ}C$ within the 20 hours, the removal efficiency of T-N reached 91.9%, which indicated the possibility of air-stripping.

• Structural Engineering and Mechanics
• /
• v.75 no.5
• /
• pp.571-583
• /
• 2020

Permeation grouting is of great significance for consolidating geo-materials without disturbing the original geo-structure. To dip into the filtration-induced pressure increment that dominates the grout penetration in permeation grouting, nonlinear filtration coefficients embedded in a convection-filtration model were proposed, in which the volume of cement particles in grout and the deposited particles of skeleton were considered. An experiment was designed to determine the filtration coefficients and verify the model. The filtration coefficients deduced from experimental data were used in simulation, and the modelling results matched well with the experimental ones. The pressure drop revealed in experiments and captured in modelling demonstrated that the surge of inflow pressure lagged behind the stoppage of flow channels. In addition, both the consideration of the particles loss in liquid grout and the number of filtrated particles on pore walls presented an ideal trend in filtration rate, in which the filtration rate first rose rapidly and then reached to a steady plateau. Finally, this observed pressure drop was extended to the grouting design which alters the water to cement (W/C) ratio so as to alleviate the filtration effect. This study offers a novel insight into the filtration behaviour and has a practical meaning to extend penetration distance.

• Membrane Journal
• /
• v.28 no.3
• /
• pp.180-186
• /
• 2018

The nano-composite membranes were prepared onto the polyvinylidene fluoride (PVDF) hollow fiber membranes through twice dip-coating known layer-by-layer method. For the first coating, poly(vinylsulfonic acid, sodium salt)(PVSA) and Poly(styrene sulfonic acid)(PSSA) were used with varying the concentration and ionic strength (IS) and the poly(ethyleneimine)(PEI) as the second coating material was fixed at 10,000 ppm and IS = 0.3. To characterize the prepared nano-composite membranes, the permeabilities and rejection ratio were measured for each 100 ppm NaCl, $CaSO_4$, $MgCl_2$, and 25 ppm MO aqueous solution. The rejections were increased as the concentrations of coating materials increased. And it was confirmed that the salt rejections for PSSA as the coating material were higher than for PVSA. Typically, the permeability, 1.848 LMH and the rejection for MO 76.3% were obtained at the coating conditions of PSSA 30,000 ppm and I.S = 1.0.

• Korean Journal of Materials Research
• /
• v.6 no.7
• /
• pp.692-699
• /
• 1996

nptype Si(100)웨이퍼를 precleaning하고 HF 용액에 dip etching한 후 E-beam dvaporator에 장착하여 Co 단일막($170\AA$, $340\AA$)과 Co/Ti 이중막($200\AA$/ $(50-100)\AA$)을 성장시켰다. 시편의 RTA 과정에서는 N2분위기에서 direct annealing 방식으로 열처리 온도와 시간을 변화시켜가며 Co-silicidation 공정을 수행하였다. Co 단일막으로 형성된 Co-실리사이드의 면저항은 $500^{\circ}C\leq$T$\leq$$850^{\circ}C$범위에서 열처리 온도와 시간의 변화에 관계없이 거의 일정한 값을 나타내었다. Co/Ti 이중막의 경우 Co-실리사이드의 형성온도가 Co 단일막의 경우에 비해 높게 나타나고 낮은 비저항의 CoSi2를 얻기 위해서는 $800^{\circ}C$이상의 온도로 열처리해야 함을 알 수 있었다. XRD 분석결과, Co 단일막으로부터 얻어진 CoSi2는 (111) 및 (220) 결정상을 나타내었으나, Co/Ti 이중막에 의한 CoSi2는 (200)결정상만이 나타나서 Si(100)기판과 에피층을 이루고 있음을 알 수 있었다. 본 실험에서 CoSi2의 비저항은 약 $18\mu$$\Omega$.cm로 나타났으며, TEM 및 AES 분석으로부터 Co/Ti bilayer-실리사이드가 다량의 Si과 Ti 외에 소량의 Co가 섞여있는 표면 복합층과, Si과 Co만이 존재하는 내부 에피층으로 구성됨을 확인하였다.

• Korean Journal of Materials Research
• /
• v.22 no.8
• /
• pp.416-420
• /
• 2012

Recently nanoscience and nanotechnology have been studied intensively, and many plants, insects, and animals in nature have been found to have nanostructures in their bodies. Among them, lotus leaves have a unique nanostructure and microstructure in combination and show superhydrophobicity and a self-cleaning function to wipe and clean impurities on their surfaces. Coating films with combined nanostructures and microstructures resembling those of lotus leaves may also have superhydrophobicity and self-cleaning functions; as a result, they could be used in various applications, such as in outfits, tents, building walls, or exterior surfaces of transportation vehicles like cars, ships, or airplanes. In this study, coating films were prepared by dip coating method using polypropylene polymers dissolved in a mixture of solvent, xylene and non-solvent, methylethylketon, and ethanol. Additionally, attempts were made to prepare nanostructures on top of microstructures by coating with the same coating solution with an addition of carbon nanotubes, or by applying a carbon nanotube over-coat on polymer coating films. Coating films prepared without carbon nanotubes were found to have superhydrophobicity, with a water contact angle of $152^{\circ}$ and sliding angle less than $2^{\circ}$. Coating films prepared with carbon nanotubes were also found to have a similar degree of superhydrophobicity, with a water contact angle of 150 degrees and a sliding angle of 3 degrees.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.35 no.3
• /
• pp.359-370
• /
• 2011

This study analyzes the textiles design of natural indigo dyed products in Korea and Japan. In this study, a total of 556 Korean natural indigo dyed products, and 2,730 Japanese natural indigo dyed products were used for analysis. The subjects of this study were 556 natural indigo dyed products and 2,730 Japanese natural indigo dyed products selling natural indigo dyed products which were found using search engine keywords of natural indigo dyeing and natural dyeing. Research and analysis was treated regarding the products, items, patterns, and the representation techniques of the patterns. The results of this study are as follows. In the pattern used for natural indigo dyed products, 71.4% of Korean products have no pattern, but 77.1% of Japanese products have patterns. On the representation techniques of the patterns, Korean products used tie-dyeing and a dip patterned fabric. While in the Japanese products, the most frequent patterning techniques were paraffin dye, followed by tie-dyeing, yarn-dyed and weaving, screen printing, and yarn-dyed and knitting. Regarding the kinds of patterns for natural indigo dyed products, only 8 kinds of patterns were used in Korean products; however, over 50 kinds of various patterns were used in Japanese products. Most patterns in the Korean products were ion patterns made by tie-dyeing. While in the Japanese products, the most frequent patterns were stripe patterns, followed by flower, dot, and ion patterns. Based on these research results, the problems of the textile design of Korean natural indigo dyed products were that most of the products have no pattern, and even though there were patterns, they lacked variations between the products. While in the case of Japan, they used the traditional and modem patterns of various textile representation techniques.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.34 no.2
• /
• pp.336-344
• /
• 2010

Stage costumes are characterized by the importance as a medium of total visual expression on a synthetic art and need to be designed more effectively. This study followed the stage costumes of the play 'Long long time ago whuo-ee whuoee' which participated in the China-Japan-Korea University Theatre Festival. By consisting of the framework of a Korean story that tells and expands the visual expression province by the access method of a producer, the unique costume in the play was created by the dyeing of the traditional hangi. First, the use of hanji in theater represents originality and a fresh variation with the formative beauty of stage costumes in accordance with hanji that conforms to the recreation of tradition. Second, the dip dyeing technique made it possible to express colors limitlessly and the airbrush dyeing technique along with dyeing twice could account for the weak points of the color. As a result, the color brought effect as expected. Third, the weak points were supported by a Jumchi technique that created the fibroid material tangled with stronger adhesion in the creation of a hangi costume. In addition, dyed hangi was attached to the outer fabric. It allowed the costume to have a unique texture that was both soft and tough. This enforced the visualization of the costume and durability to prevent possible damage by the performers. Forth, pieces of hanji were attached to the damaged parts of the costume after re-visiting the dress rehearsal. As a result, the stage costumes represented the shabby clothes that express the social class of the characters. A new understanding of the excellence of traditional hanji was found and confirmed the possibility of it as a material for stage costumes through the study.

• The Journal of Engineering Geology
• /
• v.16 no.3 s.49
• /
• pp.227-233
• /
• 2006

Bedrock is inhomogeneous for its genetically diverse origins and geological conditions when it forms, and especially, conglomerates and core-stones are one of these typical composite geo-materials composed of weak matrixes and strong pebbles. Mechanical properties of these composite bedrocks, like a conglomerate, generally vary depending on the mechanical properties and distributions of pebbles and the matrix. Therefore, regarding the consequence of understanding mechanical property of bedrocks in the designing slopes, tunnels, and other engineering facilities, empirical rock classification methods generally applied in the mechanical property modeling may not be suitable and rather, we may need some other classification methods, or tests more specific for these inhomogeneous composite bedrocks. This study includes a series of analyses to see elastic behaviors and modulus of composite geo-materials using homogenization theory. Forty nine case models were made for the elastic analysis with considering 5 factors such as gravel content, gravel size, strength of matrix, sorting and dip angle. The results analyzed are applicable to calculate elastic modulus of composite geo-materials as conglomerates and core-stones.

• Journal of Sensor Science and Technology
• /
• v.9 no.5
• /
• pp.365-372
• /
• 2000

In this study, a multichannel taste sensor using the evanescent field absorption in fiber optic was developed, and evaluated its characteristics for several basic taste substances. This sensor is based on the change of evanescent field absorption at the surface of optical fiber core layer. The sensor device was made of a plastic-clad-silica fiber (3M Co., FP-400-UHT, core diameter $400\;{\mu}m$) and a middle portion of cladding layer was removed and the surface of stripped fiber core was dip-coated with a sensing membrane. And then, it was determined the difference of evanescent field absorption into the sensing membrane, according to various taste substances and its concentrations variance. The sensing membranes were prepared with six kinds of dyes, were known as potential sensitive dye together with silicone polymer the same refractive index of cladding. Each output patterns were obtained from the sensor devices could be distinguished not only five kinds of basic taste substances such as sweetness, saltiness, sourness, bitterness and umami, but also various mixed taste substances.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.46 no.4
• /
• pp.441-448
• /
• 2010

This paper was concentrated on the distribution and the composition of lost fishing gear on the sea bed around yellow croaker fishing ground in the near sea of Jeju, Korea from April to October 2009 in order to improve the fishery environment. Recovering lost fishing gears was carried out total 10 times with a trawlnet along the isobath. As the result, it seems reasonable to conclude that the amount of lost fishing gear has a deep connection with the dip of the sea bed as well as the fishing gear scale, fishing ground and so on. The amount of recovered lost fishing gears were in order of gillnets, dragged gears, traps and ropes. In particular, traps were recovered almost every time within the survey area.