• 한국CDE학회논문집
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• 제17권3호
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• pp.216-223
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• 2012

Bill of material (BOM), which structurally represents the relation among parts constructing a product, is usually created when enterprises start to develop a new product. And it is shown as various types of BOM according to business needs and usage such as eBOM (engineering BOM), gBOM (green BOM), mBOM (manufacturing BOM), pBOM (process BOM), etc. eBOM, generally called BOM and created in the design stage of the new product, includes the drawing information of parts in the view of product function. eBOM is extended to gBOM adding the material information of parts to cope with international regulations for environment. eBOM is transformed to mBOM, which includes manufacturing sequence of parts and adds some parts required to fabricate parts and to assemble the product. mBOM is also extended to pBOM adding the process information of each part and additional assembly processes. This study introduces the concept of multi-BOM covering eBOM, gBOM, mBOM and pBOM, and proposes an advanced way to manage product data using multi-BOM system. The multi-BOM system proposed is to manage their relations using transformation function of BOM and master information of all BOMs.

• 한국세라믹학회지
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• 제38권9호
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• pp.794-798
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• 2001

Sol-gel법에 의하여 $Y_{2-x}SiO_5:Ce_x^{3+}$ (x=0.002∼0.04) 형광체를 제조하고 발광특성을 평가하였다. 800$^{\circ}$C에서 하소하였을 때는 무정형의 결정상이 나타났지만 1000$^{\circ}$C 이상에서는 $X_2$ type의 $Y_2SiO_5$ 결정상을 얻었다. 230∼360nm에서 형광체 모체의 광흡수가 일어났으며 300∼400nm에서 Ce 첨가로 인한 형광체의 광흡수가 관찰되었다. 436nm에서 최대의 발광 spectrum을 나타내었으며 $Ce^{3+}$ 함량을 0.025mol 첨가 시 $Y_{2-x}SiO_5:Ce_x^{3+}$ 형광체는 최대의 cathodoluminescence 특성과 CIE1931색 좌표 상에서 x=0.161, y=0.124의 색을 나타내었다.

• 한국약용작물학회지
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• 제16권6호
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• pp.402-408
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• 2008

This study was performed to investigate improving immune activities of natural water-soluble sulforaphane extracted from Brassica oleracea var. italica by nano encapsulation process. The nanoparticles of the sulforaphane extracted with ultrasonification process at $60^{\circ}C$ promoted human B and T cell growth, about $7{\sim}35%$ compared to the control. The secretion of IL-6 and TNF-${\alpha}$ from T cells were also enhanced as $2.6{\times}10^{-4}pg/cell$ and $2.1{\times}10^{-4} pg/cell$, respectively, by the adding nano samples. NK cell activation was improved about 8%, compare to the control in adding cultured medium of T cell added nano samples. It was also found that sulforaphane extracted from B. oleracea var. italica had highly inhibitory activity on hyaluronidase as $IC_{50}$ about $200\;{\mu}g/m{\ell}$. It can be concluded that natural water-soluble sulforaphane samples by nano-encapsulation, each size is 200 nm, extracted from B. oleracea var. italica has high immune activities through higher efficiency of bio-activation than conventional extracts.

• 공업화학
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• 제24권3호
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• pp.239-246
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• 2013

기존의 발포유리 제조공정의 원리는 원료유리분말을 거푸집에 담아 발포소성시키며, 발포소성 후에 발포체를 거푸집과 분리 후에 서냉 열처리를 하는 것이다. 이러한 이유로 기존의 발포유리 제조공정은 연속생산이 불가능하다. 본 연구에서는, 발포유리의 연속생산공정을 개발하기 위해서 거푸집을 사용하지 않는 대신, 원료유리분말을 가압성형하여 먼저 성형체를 만들고, 이 성형체를 발포시켜 발포유리를 생산하는 새로운 발포유리제조공정의 가능성을 타진하였다. 수화된 소다석회 유리분말을 사용하고 유리의 발포에 가장 핵심적인 발포제를 달리한 가압성형체를 발포소성시키는 실험 결과를 통해서, 거푸집을 사용하지 않고서도 발포유리의 연속생산공정이 가능할 수 있음을 확인하였다.

• 한국세라믹학회지
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• 제51권2호
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• pp.97-102
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• 2014

In order to improve the refresh rate of old newspaper(ONP), PCC shape-controlling experiments were carried out. The effect of a PCC polymorph on improving the quality of old newspaper was studied for a transformation from waste paper to eco-friendly paper. The synthesis of PCC consists of an in-situ process and a loading process to enhance the refresh rate of old newspaper. The characteristics between the in-situ process and the loading process could be analysed by SEM analyses of coated fiber surfaces. The retention rate ranges from 65 to 67% after the application of the in-situ process, and that after the loading process ranges from 55 to 58%. The retention rates thus show a difference of about 7-10%. In addition, the whiteness and ERIC characteristics of the in-situ process gave more efficient results than those of the loading process.

• 한국환경보건학회지
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• 제27권4호
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• 한국물환경학회지
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• 제28권5호
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• pp.657-662
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• 2012

This study was carried out to evaluate the removal rate of organic and inorganic matters from landfill leachate using pre-treatment process as coagulation and limonite adsorption, and membrane process as RO (reverse osmosis) and NF(nanofiltration). By adding limonite adsorption as pre-treatment process, about 40% of organic matters in leachate was removed through pre-treatment process and 74.7% of boron was removed after RO process without pH adjustment. The rejection rate of boron in RO process mainly depends on the pH and increased at pH value of 10. RO process was performed as two stage system adjusting pH condtion to 7 and 10 in second RO stage for boron removal. Most (>90%) of TOC, Cl- and inorganic matters as Ca was rejected in first RO stage, the residue was rejected in second RO and the rejection rate was above 97%. Considering economic efficiency of operation cost, NF substituted for the first RO and total removal rate of TOC was above 90%. Through RO system toxicity to Daphnia in leachate was removed completely.

• 한국전기전자재료학회논문지
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• 제14권11호
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• pp.904-911
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• 2001

High-density lead zirconate titanate(Pb(Zr$\_$0.53/Ti$\_$0.47/)O$_3$, PZT) ceramics were fabricated by a new milling-precipitation(MP) process improved from the conventional solid state process. This process was progressed by a milling impregnation through mixing ZrO$_2$ and TiO$_2$ powders with lead nitrate(Pb(NO$_3$)$_2$) water solution in zirconia ball media, and then milling precipitation was induced from precipitation of PbC$_2$O$_4$ by adding ammonium of oxalate monohydrate((NH$_4$)$_2$C$_2$O$_4$$.$H$_2$O) as a precipitant. As a result of this process, single-phase perovskite structure was formed at the calcination temperature of 750$\^{C}$ for Pb(Zr$\_$0.53/Ti$\_$0.47/)O$_3$ powders. In addition, the highest density at the sintering temperature of 1100$\^{C}$ was obtained, because of the highly sinterable PZT Powders ground through the re-milling process. Piezoelectric and dielectric properties of sintered sample were improved by MP process.

• Design & Manufacturing
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• 제18권2호
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• pp.29-34
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• 2024

This study intends to reduce forming load by adding die rotation to flange-upsetting process. Materials arc formed by the compression and rotational torque which are accrued from rotation of the lower die accompanied by axial compression of the punch. For the theoretic analysis of flange-upsetting process using rotation die, slab method was used. Furthermore, for the verification of the theoretic analysis results, FEM simulation using DEFORM 3D a commercial software was done, and through the model material experiment using Prasticine, the results were compared and reviewed. Flange-upsetting process using rotation die shows reduced forming load compared with process without die rotation and demonstrates uniform distribution of strain. And as for the effect of the reduction of forming load, the less the aspect ratio(h₀/d₀) and the greater friction coefficient, the greater effect is. With increase in die rotation velocity, the effect of forming load reduction also increases little by little, but its effect on forming load reduction is very negligible compared with other forming parameters. Theoretic analysis results and simulation results coincided pretty well. The flange-upsetting process using die rotation are evaluated as useful process that can produce reduction of forming load and uniform strain.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3429-3434
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• 2007

An experimental study was carried out to investigate gasification process of wood sawdust in the I-dimensional downdraft fixed bed gasifier. The preheated air was used oxidizer and steam were used as a gasifying agent. The operating parameters, the supplied air temperature and steam were used. The oxidizer temperature was varied from 500K to 620K and vapor was added. The gasification process was monitored by measuring temperature at three position near the biomass using R-type thermocouples and the syngas composition was analyzed by gas chromatograph. The change of hydrogen and carbon monoxide, carbon dioxide, methane was observed. Overall, the volume fraction of hydrogen and methane were increased widely as increasing the oxidizer temperature and adding steam.