• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.263-271
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• 2010

e-Printing is a new manufacturing technology for electronic products and is based on traditional printing technology. The electronic products require a large area to facilitate printing and to be economical. A gravure printing system that supports a roll to roll (R2R) manufacturing process can be used to reduce the cost and to achieve the required accuracy. Many factors such as drying method, drying temperature, tension,-printing velocity, ink viscosity, ink conductivity, pattern accuracy, and dot geometry influence the performance of printed electronics. These factors are closely interrelated. The optimum condition for printing must be determined to enhance the performance of the printed electronics. In this study, lines and areas are printed using a gravure printer with conductive ink under different conditions of the above mentioned factors. The results are analyzed to investigate the influence of various factors on the performance of the printed electronics.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.321-327
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• 2019

The purpose of this study is paper is to improve the flow performance and to reduce the aerodynamic noise of air discharge system consisting of a centrifugal fan, ducts and a housing for the clothes dryer. Using computational fluid dynamics and acoustic analogy based on FW-H (Ffowcs-Williams and Hawkings) Eq., air flow field and acoustic fields of the air discharge system are investigated. To optimize aerodynamic performance and aerodynamic noise, the response surface method is employed. The two factors central composite design using the inflow and outflow angles of fan blades is adopted. The devised optimum design shows the reduction of turbulent kinetic energy in the ducts and the housing of the system, and as a result, the improved flow rate and reduce noise is confirmed. Finally, the experment using the proto-type manufactured usign the optimum design shows the increase of flow rate by 4.2 %.

• Korean Chemical Engineering Research
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• v.59 no.3
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• pp.435-442
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• 2021

Mn-added Barium hexaaluminates were manufactured by homogeneous precipitation method using Urea. The effects of water wash and dry temperature were analyzed by thermal weight analysis, X-ray diffraction analysis, and scanning electron microscopy. Catalysts that went through the filtration step only produced pure hexaaluminate images compared to those that went through the water wash step. During the drying process, it seems that the remaining urea helps dehydration of the precursor and affects the phase shift of gibbsite to boehmite, which is easy to convert to pure hexaaluminate. The catalyst WO200 gave the best performance in the methane combustion reaction, and NOx was not emitted in the reaction for all catalysts. Hexaaluminates were found to affect reducing the highest CO emissions.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.2
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• pp.53-61
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• 2023

Most of the sewage sludge is organic waste containing a large amount of organic substances decomposable by microorganisms by biological treatment. As for existing sewage sludge treatment methods, reduction and fuel conversion are being carried out using technologies such as drying, incineration, torrefaction, carbonization. However, the disadvantage of high energy consumption has been pointed out as latent heat of 539 kcal/kg is consumed based on drying. Therefore, in this study, we intend to produce solid fuel through hydrothermal carbonization(HTC), which is a thermochemical treatment. To evaluate the value of solid fuel, the characteristics of carbonization and fuel ratio were analyzed. As a result, as the hydrothermal carbonization reaction temperature increased, the lower heating value also increased by about 500 kcal/kg due to the increase in the degree of carbonization. H/C, O/C, ratio showed a decreasing trend from 1.78, 0.46 to 1.57, 0.32. When the ratio of ash to combustible content (fixed carbon + volatile) of dry sludge was 0.25 or more, it was derived that the degree of carbonization and calorific value did not increase even when hydrothermal carbonization was performed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.102-102
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• 2020

가시오가피(Acanthopanax senticosus)는 오갈피나무과(두릅나무과, Araliaceae)에 속한 낙엽관목인 가시오갈피나무 Acanthopanax senticosus Seem. 또는 기타 동속 식물의 뿌리 및 줄기 껍질이다. Acanthopanax 속 식물의 잎에 대한 약리 연구로는 위장보호작용, 항산화작용, 소염진통작용, 항암작용, 항균작용, 심근경색 개선 작용, 혈당강하작용 등에 대한 탁월한 효과가 알려져 있다. 그 중 가시오가피는 모든 오갈피 나무를 통틀어 약효가 가장 높고 보약의 역할을 한다. 인삼의 가공 과정을 적용하여 가시오가피를 증숙하면 수배에서 수십배까지 생이용성과 생리활성이 증진되나, 이렇게 제조하기 위해서는 증숙 및 냉각하는 공정을 반복적으로 가하고 효소 처리하는 증 가공 공정으로 의해 가격이 증가하게 된다. 콩단백은 콩기름이나 두부를 제조하고 남은 부산물로 영양학적으로 쇠고기 단백질과 비견할 만큼 우수한 영양학적 가치를 가지지만, 이용되는 양은 현저히 적어 이에 따른 활용도가 요구되고 있다. 압착대두 단백은 압착방식으로 기름을 짜고 남은 부산물을 파우더 형태로 가공하여 6% 가량의 지방질과 Glutamic acid, Arginine, Aspartic acid, Alanine 등 여러 가지 필수 아미노산을 제공한다. 이에, 본 연구에서는 압착대두단백과 두부건조분말을 가시오가피 소재의 기능증진 소재로 활용하고자 한다. 건조 가시오가피와 콩단백 분말의 비율을 1:0, 1:1, 1:10, 10:1로 하여, 고온고압 혼합 가공한 효과를 측정하였다. 가시오가피 단독 가공한 것에 비하여, 가시오가피-콩단백 가공물에서 가시오가피 단독 열가공에 비해, 가시오가피의 항산화도가 약 2-4배 증가하였고, 가시오가피 사포닌의 생이용성이 현격하게 증가함을 확인하였다. 본 연구는 콩가공 부산물의 고부가가치 산업화에 기여할 뿐만 아니라, 가시오가피 산업 활성에도 기여할 수 있을 것으로 기대된다.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.151-158
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• 1983

This study was performed to obtain a basic materials for improvement of garlic storage ability. The "Namhae jaerae" of southern strain and the "Dalsung jaerae" of northern strain were harvested by period, their stems were cut at 7cm and 25cm from disk and then placed them in blast drying system 12 hours per day at $40^{\circ}C$ for 4 days, or in natural state. The decrease rate of bulb weight was compared and rooting, sprouting, the rate of decay was investigated between natural dry(conventional method) and hot-air dry (blast drying system). The results obtained were as follows. In the case of the decrease rate of bulb weight after hot-air dry; 7cm plot" "Namhae jaerae" was similiar to one of 13th day of natural dry and 25cm plot 14th day. In "Dalsung jaerae" 7cm plot of early, common and late harvest was respectively similiar to one of 22nd, 18th and 16th day of natural dry, 25cm plot of early, common and late harvest showed the same decrease rate of bulb weight as that of 18th, 16th and 14th day of natural dry respectively. In the case of rooting and sprouting in sand culture at the early period of storage, hot-air dry showed more prolonged tendency than conventional drying method. In the case of clove state in the latter period of storage, number of eatable cloves was more numerous and number of decayed cloves were less in blast drying system than in conventional method.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.52-60
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• 2004

The basic approach to sewage sludge is organic waste minimization, promotion of energy recovery; volume and weight reduction by final treatment, and environmentally final disposal of natural circulation. Dry and pyrolysis of maize was experimentally investigated in full-scale rotary kiln in semi-continuous operation. The operational parameters varied are the operating temperature $160{\sim}175^{\circ}C$ of dry and $450{\sim}800^{\circ}C$ of pyrolysis, the solids residence time 9 min for pyrolysis. Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C_4{\sim}C_6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.58.2-58.2
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• 2010

FPD (Flat Panel Display) 제조 공정에서 사용되는 패턴은 수 ${\mu}m$ 수준까지 감소하였으며, FPD의 크기는 급격하게 대형화 되여 현재 8세대(2200mm*2500mm)에 이르고 있다. 이에 따라, $1\;{\mu}m$ 이상의 크기를 갖는 오염입자에 의한 수율 저하를 극복하기 위한 세정효율의 향상 및 다량의 초순수 사용에 따른 폐수 발생으로 인한 환경오염, 또한 장비의 크기에 따른 공간 효용성 감소와 이에 따른 공정 비용의 증가 등의 어려움에 직면하고 있다. 따라서, 현장에서는 고효율, 저비용의 세정 공정 기술 개발에 대한 연구가 활발히 진행되고 있다. 이러한 문제점들을 해결 하고자 이류체 노즐 세정 장치와, 화학액 린스를 위한 초순수 Spray, 건조 공정에 해당하는 Air-knife, Halogen lamp로 구성된 소형화 된 고속 FPD(Flat Panel Display) 세정기에 대한 연구를 진행 하였다. 이류체 노즐은 초순수와 $N_2$ 가스를 내부에서 혼합하여 액적(Droplet)을 형성하여 고압으로 분사시키는 장치로서 화학액을 사용하지 않고 물리적인 방법으로 오염입자를 제거한다. Spray는 유기 오염입자 제거를 위한 오존수의 린스 공정을 위해 설치 하였다. 세정 후 표면에 남아있는 기판의 액막(water film)은 고압의 가스를 분사하는 Air-knife를 통해 제거하였으며, 고속 공정시 발생할 수 있는 Air-knife에서 제거하지 못한 잔류 액막을 Halogen lamp를 사용하여 효과적으로 제거함으로써, 물반점(water mark) 없는 건조 공정을 얻을 수 있었다. 실험에는 미세 입자의 정량적인 측정을 위하여 유리 기판 대신에 6인치 실리콘 웨이퍼(P-type (100))를 사용하였으며, > $\;1{\mu}m$ 실리카 입자를 스핀방식을 사용하여 정량적으로 균일하게 오염하였으며, 오염물의 개수 및 분포는 파티클 스캐너 (Surfscan 6200, KLA-Tancor, USA)를 사용하여 분포 및 개수를 정량적으로 측정 하였다. 이류체 노즐은 $N_2$ 가스의 압력과 초순수의 압력을 변화시켜 측정하여, 각각 0.20 MPa, 0.01 MPa에서 최적의 세정 결과를 얻을 수 있었으며, 건조 효율은 Air-Knife의 입사 각도와 건조면 간격, 할로겐 램프의 온도를 조절 하여 최적의 조건을 얻을 수 있었다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.181-188
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• 2005

Generally, high performance concrete has characteristics such as low water-cementitous material ratio, lots of unit binder powder, thus the drying shrinkage and autogenous shrinkage are tend to be increased. The purpose of this study is to investigate the effect of the glyclos based shrinkage reducing agent on the drying shrinkage and autogenous shrinkage of high performance concrete with 30% of water-cemetitious material ratio as a study to develop the technology to reduce the concrete shrinkage. Test results show that the drying and autogenous shrinkage of high performance concrete are reduced by about 20~35% at the mixing ratio of shrinkage reducing agent of 0.5%, and 1.0%, compared with plain concrete. Therefore, it analyze that the using of shrinkage reducing agent is effective to reduce the drying shrinkage and autogenous shrinkage of high performance concrete.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.229-232
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• 1998

This study was conducted to determine the properties of seedling plate papers currently used in commercial production, then to get basic information for manufacturing new seedling plate paper. Imported seedling plate paper had high wet tensile and burst strengths in its usage circumstances. Wet tensile strength was very high with 38.7% of dry tensile strength. Wet burst strength was also very high with 62.4% of dry burst strength. The seedling plate paper contained about 30% of synthetic fibers. It had 10 Gurley sec. in air permeability indicating effective movement of air. Seedling plate papers were' made in laboratory scale. For sufficient sizing degree, the addition of 0.5% AKD (alkylketene dimer) by weight was good enough. Additional amount of AKD more than 0.5% by weight caused strength loss even though improving sizing effect. The addition of wet strength reagent such as Finex-B 2% by weight resulted in good strength and air permeability.