• 한국세라믹학회지
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• 제53권5호
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• pp.541-547
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• 2016

In developing high temperature molds with advantages of the sand and precision (investment) castings, mechanical properties of the mold were improved through homogeneous coating of starting powders with an inorganic binder and improvement of fabrication process. Beads with mullite composition were employed for properties of the mold under high temperature, which was compared with artificial sands. Precursors of silica and sodium oxide were used as starting materials for an inorganic binder to achieve homogeneous coating on the starting powders. Strength was enhanced by the glass phase converted from the inorganic binder through heat treatment process. Also, two kinds of process, wet and dry processes, were incorporated to prepare mold specimens. Consequently, fabrication process of the mold with superior strength and high temperature applicability, compared with the previous molds for sand casting, could be suggested through control of the starting material and enhancement of the vitrification efficiency.

• 한국가구학회지
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• 제19권3호
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• pp.172-179
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• 2008

The objective of this study was to investigate the influence of the water repellents' treatment on the water absorptivity and the dimensional stability of Korean red pine wood(Pinus densiflora). The alkylketene dimer(AKD), fluororesin emulsion(Wood-seal, WS), and paraffin wax emulsions(PW25, PW40, and PW1200) were used as water repellents. PW40 and WS were proved as excellent water repellents for pine wood, because the samples treated with these agents showed high contact angles and large reduction in water absorptivities. Also, the dimensional stability(antiswelling efficiency) of pine wood was considerably improved by water repellents treatments, such as PW40 and WS at the pressure of 2MPa. The water repellent treated woods with WS, PW40, and PW1200 at the pressure of 2MPa were relatively stable to the wet-dry cyclic leaching test.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.15-19
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• 1996

To utilize the waste materials and develope wood adhesive from isolated bloods of slaughtered cow and pig and also to prevent water pollution, simple and rapid method of isolation and purification of plasma proteins from pig bloods with trichloroacetic acid(TCA) treatment was developed. Adding of TCA-precipitated blood powder to the phenol formaldehyde resin(PF) improved dry and wet strength of plywood and resulted in fast hot pressing times.

• 한국산업융합학회 논문집
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• 제16권2호
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• pp.47-52
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• 2013

Aim of this study is to investigate the dimensional and shrinkage characteristics of the weft knitted fabrics with Polylactic acid(PLA) knitted yarn. This PLA knitted yarn was made of the biodegradability fiber. The structure of weft knitted fabrics that was utilized for this study is the plain stitch, which is the most basic structure among all weft knitted fabrics. As the stitch length is shorter, the stitch density, courses density, and wales density are more increasing. The stitch density increased as pre-treatment process and dyeing process progressed. On the contrary, the heat setting process made it decreasing. The MR(Machine Relaxation) and DR(Dry Relaxation) standard area shrinkage were increasing as wet process progressed and as the stitch lengths are long.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.828-831
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• 2005

Producing high transparency dielectric is still one of the most important subjects in the PDP process for improving luminous efficiency. It has been reported by many workers that transparency is improved by controlling the composition of the frit, the frit size and distribution, and the firing atmosphere. To understand the mechanism of discoloration of frit, $Bi_2O_3$ and $B_2O_3$ glasses were used for a leaching test using water and alcohol solution in milling. As a result, the frit prepared by wet milling had lower chemical durability than that prepared by dry milling. The leached layer around the frit showed high stability for heat treatment because the frit surface was covered with hydroxides or hydrates which was resulted from a reaction between the frit and the solution during milling.

• Carbon letters
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• 제7권1호
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• pp.27-33
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• 2006

Carbon-ceramic composites were fabricated by using fly ash and PANOX fibers as reinforcement. Fly ash, because of its small size particles e.g. submicron to micron level can be effectively dispersed along with fibrous reinforcements. Phenolic resin was used as carbon precursor. Both dry as well as wet methods were used for forming composites. The resulting composites were characterized for their microstructure, thermal and mechanical properties. The microstructure and mechanical properties of composites are found to be dependent on type of the fly ash, fibrous reinforcements as well as processing parameters. The addition of fly ash improves hardness and the fibers, which get co-carbonized on heat treatment, increase the flexural strength of the carbon-ceramic composites. Composites with dual reinforcement exhibit about 30-40% higher strength as compared to the composites made with single reinforcement, either with fly ash as filler or with chopped fibers.

• Asian-Australasian Journal of Animal Sciences
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• 제29권4호
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• pp.530-538
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• 2016

Two experiments were conducted to determine the nutrient composition, in vitro ruminal ammonia concentrations and pH of wet distillers grains (WDG, produced from tapioca 70% and rice 30%) and to evaluate dietary effects of fermented total mixed ration (TMR) using WDG on the performance, blood metabolites and carcass characteristics of Hanwoo steers from mid fattening to slaughter. In Exp. I, average dry matter (DM), crude protein, ether extract, crude fiber, ash, neutral detergent fiber, acid detergent fiber, and nitrogen free extract of seven WDG samples from an ethanol plant with different sampling dates were 19.9%, 24.8%, 3.8%, 21.8%, 8.87%, 60.3%, 34.5%, and 40.7% (DM basis), respectively. For in vitro ammonia concentrations and pH, each sample was assigned to 7 incubation times (0, 4, 8, 12, 24, 48, and 72 h). Linear increase was observed between 12 and 48 h for ammonia concentrations, but final ammonia concentrations (72 h) were not significantly different among WDG samples and fermentation patterns of WDG samples showed similar tendency. In vitro pH varied among treatments from 0 to 24 h, but were not different statistically after 48 h. In Exp. II, 45 Hanwoo steers of 23 months ($641{\pm}123kg$) from mid fattening period to slaughter (248 days) were randomly divided into three groups of 15 pens each (five repetitions/each treatment) and assigned to one of three dietary treatments; i) Control (TMR), ii) WDG 15 (TMR containing 15% of WDG, as fed basis) and iii) WDG 28 (TMR containing 28% of WDG, as fed basis). The body weight (BW), ADG, and feed conversion ratio (FCR) of control and WDG 15 and 28 during 248 days were 760.8, 740.1, and 765.5 kg, and 0.50, 0.50, and 0.52 kg/d, and 18.6, 17.6, and 17.1, respectively. The dry matter intake (DMI) (kg/d) of control (9.11) was higher (p<0.05) than WDG treatments (WDG 15%, 8.57; 28%, 8.70). Nevertheless, DMI did not affect BW, ADG, and FCR of Hanwoo finishing steers. Blood metabolites were in normal ranges and were not different among treatments except the albumin concentration. In carcass characteristics, WDG 15 (30%) showed higher frequency of A-carcass yield grade than WDG 28 (15%) and control (7%), and WDG 28 (61%) showed higher frequency of $1^{{+}{+}}$ and $1^+$-carcass quality grade than WDG 15 (40%) and control (60%). In conclusion, using WDG up to 28% in TMR did not show any negative effect on the performance and blood metabolites, and improved carcass quality of Hanwoo steers. Therefore, WDG can be a useful feed ingredient for Hanwoo steers in mid-fattening period to slaughter.

• 한국의류산업학회지
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• 제21권4호
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• pp.509-514
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• 2019

Cotton fabrics were treated with gelatin to enhance dyeability and color strength when using Caesalpinia sappan dye. Gelatin was used as the protein and a pad-dry- cure method was used for the treatment process (2, 4, 6, 8, 10, 12, 14g/l concentration). Pretreated fabrics were mordanted with 10% alum. Fabrics were then dyed with freeze-dried sappan wood water extract powder form. Dyed samples were assessed in regards to dyeing behavior and color fastness. Comparing untreated and gelatin treated samples from the SEM images indicated that the Gelatin treatment (10g/l) resulted in an enhanced surface roughness that was relative to that of untreated cotton. Padding cotton with gelatin at 6g/l concentration afforded dyed fabrics with a 2 times increase in the K/S value over that of untreated fabrics. All dyed samples were red color with a significant enhancement in the sample color strength (K/S) being observed for pretreated samples. pH values favor dye absorption with pH 7 yielding the highest color strength. Dyeing at an elevated temperature resulted in a lower color strength and reddish-dull color. Longer dyeing times created greater color strengths for untreated and gelatin treated cotton. Increased dye concentrations resulted in higher K/S values for both gelatin treated and untreated cotton. As for color fastness, gelatin treated and untreated cotton fabrics dyed with sappan wood extract showed a relatively low rating in washing fastness (color change 1 rating), light fastness (1 rating), and rubbing fastness (wet:1-2, dry:3-4 rating).

• 한국식품영양학회지
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• 제29권5호
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• pp.618-627
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• 2016

쌀음료베이스 개발을 위한 품종별 가공용 쌀의 기초자료 확보를 위해 국내산 쌀 7종(삼광, 일품, 설갱, 안다, 다산1호, 고아미4호, 단미)과 수입쌀 3종(미국쌀, 중국쌀, 태국쌀)을 대상으로 수화, 호화 및 당화 관련 특성을 살펴보았다. 품종별쌀의 수분함량은 11.88~15.26% 범위로 나타났으며, 수분흡수율은 안다, 미국쌀이 가장 높게 나타났다. 수분결합력은 태국쌀이 가장 높았으며, 단미, 고아미4호 및 설갱은 낮은 수분결합력을 나타내었다. 용해도는 10종의 시료 중 단미가 월등히 높은 26.6%를 나타내었으며, 팽윤력은 설갱, 안다, 미국쌀이 유의적으로 높은 수준을 나타냈다(p<0.05). 품종별 쌀가루의 아밀로오스 함량은 고아미4호와 태국쌀이 가장 높은 반면, 단미가 가장 낮았다. RVA를 측정한 결과, 호화온도는 단미와 고아미4호가 각각 $91.6^{\circ}C$와 $78.5^{\circ}C$로 가장 높았고, 그 외 품종은 $68.0{\sim}71.1^{\circ}C$로 나타났다. 최고점도와 최종점도는 다산1호가 가장 높았고, 단미가 가장 낮게 나타났다. 치반점도는 일품과 미국쌀이 낮게 나타나, 노화가 더디게 진행될 것으로 예상되었다. 한편, 쌀, 수침처리 쌀, 건식쌀가루, 습식쌀가루로 가공용 쌀 전처리를 달리하고, 수침시 흡수되는 수분량을 고려하여 물을 첨가하고, 고온용 ${\alpha}$-amylase 처리 후 당화특성을 비교하였다. 당화액의 pH는 일품을 제외한 모든 품종에서 습식쌀가루가 유의적으로 높게 나타났다(p<0.05). 가용성 고형분 함량은 대부분 수침처리한 것보다 수침처리하지 않는 것, 쌀보다는 쌀가루의 효소처리가 더 효과적으로 높게 나타났다. 환원당 함량은 전처리 방법에 따라 수침처리하지 않는 것보다 수침처리한 것, 쌀보다는 쌀가루가 유의적으로 더 높게 나타났다(p<0.05). 색도는 L값의 경우 고아미4호를 제외한 대부분 품종에서 쌀보다 수침처리한 쌀이 낮은 값을 보였다. a값은 수침처리하지 않는 쌀과 습식쌀가루에서 낮은 값을 보였으며, b값은 쌀보다 수침처리한 쌀, 건식쌀가루보다 습식쌀가루가 품종에 따라 다소 차이가 있는 것으로 나타났다(p<0.05). 이러한 연구결과를 종합해 보면, 쌀을 원료로 한 음료베이스 개발을 위해서는 원료곡의 호화, 액화 및 당화에 영향을 주는 여러 가지 인자와 품종별 특성을 고려한 접근이 이루어져야 할 것이다.

• 박물관보존과학
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• 제9권
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• pp.67-83
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• 2008

국립중앙박물관이 소장하고 있는 청연군주 출토복식(신수751 의류 일괄) 중 織金 및 金箔이 있는 복식의 보존 처리 과정을 소개하고자 한다. 금사 및 금박의 비파괴분석(X-선형광분석:XRF)을 실시한 다음 표면의 금(Au)이 열화가 진행되면서 분상화된 금층에 아교 2%용액을 도포하여 접착력을 강화하였다. 표면의 먼지와 오염물제거를 위해 진공흡입을 통한 건식세척과 분사식 습식세척을 병행하였고 손상부분을 보수하여 유물의 원형을 회복하였다.