• 한국식품영양과학회지
• /
• 제30권3호
• /
• pp.455-459
• /
• 2001

Tofu (soybean curd) was made with whole soybean flour (WSF, 420 mesh) by various processing conditions of water addition ratio, heating time, coagulation temperature, molding pressure and 0.3% of mixed coagulant (CaSO₄:GDL=50:50(w/w)). Yield content of WSF-tofu was the highest in processing condition of 85℃ coagulation temperature, 10 times water addition, 5min. heating time and 25.00 g/㎠ molding pressure. As the increase of the water addition ratio from 8 to 14 times (water:WSF, v/w), Hunter's L and a values were increased. Raising of heating time (100℃, 1, 5, 10 and 15 min), a and b value were increased. Textural properties of WSF-tofu were significantly affected by coagulation temperature (75, 80, 85 and 90℃). Hardness was increased, but adhesiveness and cohesiveness were decreased. heating time was influenced on harness of WSF-tofu, but water addition ratio was not affected on hardness of WSF-tofu. Increasing of molding pressure (16.83, 25.00, 33.22 and 41.67 g/㎠, 1 hr) was resulted from a increased hardness, gumminess and chewingss of tofu, but adhesiveness was addition ratio, 5 min heating time and 25.00 g/㎠ molding pressure recorded the highest score in sensory evaluation test.

• 한국주조공학회지
• /
• 제8권4호
• /
• pp.459-466
• /
• 1988

This study was carried out in the austempering temperature and time after Ni, Mo addition in purpose of modification of impact toughness of austempered ductile irons. Addition of alloy element and austempering treatment of $900^{\circ}C$ 60 minutes followed by $300^{\circ}C$, $350^{\circ}C$ and $400^{\circ}C$ for 60 minutes, in this case impact value was increased by ideal mixed structure. But impact value was decreased when holing time is 120minutes, this is attributed to segregation and carbide precipitation from high carbon austenite. Highest impact value was obtained by $350^{\circ}C$ (Mo-addition) and $400^{\circ}C$ (Ni-addition). This phenomena was caused by presence of remained austenite. At all austempering temperature,, Ni-added specimen showed higher impact values than that of Mo-added specimen. And hardness property was affected by austempering temperature and holding time rather than amounts of alloying element.

• Steel and Composite Structures
• /
• 제46권5호
• /
• pp.689-707
• /
• 2023

Geopolymer concrete production is interesting as it is an alternative to portland cement concrete. However, workability, setting time and strength expectations limit the sustainable application of geopolymer concrete in practice. This study aims to improve the production of geopolymer concrete to mitigate these drawbacks. The improvement in the workability and setting time were achieved with the additional use of NaOH solution whereas an increase in the strength was gained with the addition of recycled steel fibers from waste tires. In addition, the use of 25% basalt powder instead of fly ash and the addition of recycled steel fibers from waste tires improved its environmental feature. The samples with steel fiber ratios ranging between 0.5% and 5% and basalt powder of 25%, 50% and 75% were tested under both compressive and flexure forces. The compressive and flexural capacities were significantly enhanced by utilizing recycled steel fibers from waste tires. However, decreases in these capacities were detected as the basalt powder ratio increased. In general, as the waste wire ratio increased, the compressive strength gradually increased. While the compressive strength of the reference sample was 26 MPa, when the wire ratio was 5%, the compressive strength increased up to 53 MPa. With the addition of 75% basalt powder, the compressive strength decreases by 60%, but when the 3% wire ratio is reached, the compressive strength is obtained as in the reference sample. In the sample group to which 25% basalt powder was added, the flexural strength increased by 97% when the waste wire addition rate was 5%. In addition, while the energy absorption capacity was 0.66 kN in the reference sample, it increased to 12.33 kN with the addition of 5% wire. The production phase revealed that basalt powder and waste steel wire had a significant impact on the workability and setting time. Furthermore, SEM analyses were performed.

• 한국조리학회지
• /
• 제2권
• /
• pp.183-207
• /
• 1996

This study is to investigate the effect on the quality and properties of bread affected by licorice extract addition. The measurements of the farinograph, extensograph and amylograph on dough are carried out. And the evaluations of volumetric changes during fermentation, shape of bread crumb, sensory test, firmness are obtained. The obtained results are as follows. 1. Proximate compositions of licorice extract are as follows: moisture 73.7%, crude protein 4.1%, crude lipid 2.8%, crude ash 1.4%. 2. Water absoorption, arrival time dough development time mechanical tolerence index and valorimeter value are increased but stability is decreased with the addition of licorice extract. 3. The resistance to extension is increased but extensibility is decreased with the addition of licorice extract. 4. The initial pasting and highest viscosity temperatures are not affected but the highest viscosity is steepy decreased over 1.0% addition of licorice extract. 5. The volume of dough during fermentation and specific volume of bread is decreased with the addition of licorice extract. 6. The grain of bread is to be rough and irregular and the firmness is increased with the addition of licorice extract. 7. The records of sensory test are decreased with the addition of licorice extract.

• 동아시아식생활학회지
• /
• 제17권1호
• /
• pp.103-109
• /
• 2007

The optimum conditions for springiness of polymannuronate acorn mook, in which polymannuronate was added to acorn powder, was investigated by the response-surface method(RSM). The fractional factorial design with three variables, i.e. polymannuronate addition, water addition and boiling time, and with three levels revealed that the range of acorn springiness was $0.804{\sim}0.987$. The governing equation was also partially differentiated for boiling time, showing that the optimum manufacturing condition for $90^{\circ}C$ is addition of 2% polymannuronate, addition of 120 mL of water, and 60 minutes of boiling time.

• 한국가스학회지
• /
• 제25권2호
• /
• pp.1-12
• /
• 2021

MILD(Moderate or Intense Low-oxygen Dilution) 연소는 열에너지 분야에서 배출되는 미연 탄소와 질소 산화물을 저감하기 위한 기술로, 친환경 열 에너지 생산 기술로 평가받고 있다. MILD 연소 기술은 반응물의 예열을 통한 자발화 현상을 이용하여, 연소 반응 영역을 확장시키는 것이 핵심이다. 본 연구는 CH₄와 공기를 활용하여 반응물의 초기 온도 변화와 CO, H₂의 혼합율에 따른 CH₄의 점화 지연 시간을 수치 해석적 접근을 통해 분석하였다. 점화 지연 시간은 초기 온도와 H₂ 혼합율이 높을수록 감소하였고, CO 혼합율이 높을수록 증가하였다. 이는 H₂ 첨가 시 초기에 높은 분율의 HO₂가 메틸 라디칼(CH₃)의 분해 반응을 촉진시켜 OH를 생성하였기 때문이며, CO 첨가 시 HCO 생성에 따른 H 라디칼 소모가 증가했기 때문이다. 하지만 HCO의 생성은 점화 지연 시간에 큰 영향을 주지 않았다. 또한 연료 내 CO와 H₂를 30% 혼합한 조건에서는, NO 배출량이 각각 7%, 1% 증가하는 경향을 보였다. 이는 CO를 혼합한 조건에서 초기에 높은 NCO가 NO 생성반응률 증가에 영향을 미쳤기 때문이다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권4호
• /
• pp.221-225
• /
• 1999

This paper shows the parameters to affect the critical characteristic of YBaCuO superconducting bulk fabricated by MPMG (Melt Powdered Melt Growth)process. In order to investigate proper processing variables, the effect of the holding time at the melting temperature and that of the slow cooling time in $O_2\; ambient\; on\; the\; J_c$ were experimented. And then with the above obtained heat treatment conditions, the effects of addition of $Y_2BaCuO_5\; and\; Ag\; on\; the\; J_c$ were also investigated. A proper slow cooling time yields phase transformation from Tetragonal $(YBa_2Cu_3O_6)$ to Orthorhombic $(YBa_2Cu_3O_7)$ during an annealing time in $O_2$. Ag addition plays a role in increasing the $T_c\; and\; the J_c$, but the magnetization decreases. The $J_c$ and the magnetization increase with addition of Y211. $J_c$ of the sample added Ag 10wt% is superiorover 3000 G. Proper holding time, slow cooling time and amount of impurity addition are important parameters in fabricating the YBaCuO bulk by MPMG process with high $J_c$.

• 한국식품영양학회지
• /
• 제14권4호
• /
• pp.346-354
• /
• 2001

Physicochemical properties of dough and bread supplemented with onion (Allium cepa L.) powder were investigated. Farinographic characteristics of dough showed that addition of onion by 2% and 4% increased water absorption, however, as the onion added more the water absorption decreased. Addition of 2% onion delayed time for development of dough a little, while more than 4% onion shortened the development time significant1y. A reduction in stability and an Increase in weakness of dough were observed by addition of onion. Addition of onion powder resulted in a reduction of extendibility and an increase in resistance to extension of dough as measured by extensograph. Amylographic analysis showed that addition of onion increased gelatinization temperature and decreased maximum viscosity. Moisture content, baking loss, height and volume of bread tended to decrease with the addition of onion powder. Lightness of bread crust and crumb decreased as the onion powder added more, while redness and yellowness increased. Bread tilth onion powder had mode free amino acid. especially, Arginine. aspartic acid, glutamic acid and alanine, than control. The addition of onion hardness of bread increased, but springiness decreased as the onion added more. Sensory evaluation of bread indicated that addition of 2% and 4% onion powder enhanced springiness, mouth feeling, appearance, hardness, moistness and overall acceptability.

• Preventive Nutrition and Food Science
• /
• 제8권3호
• /
• pp.230-234
• /
• 2003

Mass transfer characteristics during osmotic dehydration of carrots were studied as functions of immersion temperature and time, and sugar and salt concentrations. The effect of osmotic dehydration on the degree of browning of air-dried carrots was also evaluated. Increasing the immersion temperature and time, sugar concentration, and salt addition increased water loss, sugar gain, molality and rate of dehydration. The water loss and increases in solids, and molality were rapid in the beginning of the process and then increased slowly during remainder of the process. Increasing 1 or 2% salt concentration in the 40$^{\circ}$Brix sugar solution at 6$0^{\circ}C$ increased water loss and solid gain. Salt addition was not able to significantly affected on water loss and solid gain compare to temperature (40～8$0^{\circ}C$) and sugar concentration (20～60$^{\circ}$Brix) changes due to the low salt concentration. A minimum degree of browning of the air-dried carrots (O.D. = 0.048) could be achieved using binary solutions (40$^{\circ}$Brix sugar solution with 2% salt addition) with 24 min of immersion time compared to control (O.D. = 1.308) or blanching with 24 min of immersion time (O.D. = 0.174).

• 한국주조공학회지
• /
• 제24권2호
• /
• pp.85-93
• /
• 2004

Mechanical property of hypereutectic Al-Si alloy is changed according to size and distribution of primary Si. Consequently, the study on the refinement for primary Si is progressed for a long time. But such effect of refinement comes out fading phenomena with the lapse of time. Therefore, this study investigated the optimum condition of primary Si refinement for hypereutectic Al-Si alloy. And we observed various primary Si size with P's fading phenomena. The experiment results were as follows. For experiment of primary Si refinement, we made hypereutectic Al-Si alloy with various amounts of P addition. As a result of experiment, we obtained the fine microstructure at 0.01wt.%P. And the optimum condition of P addition, for preventing from growth of primary Si by P fading, is estimated 0.1wt.%P.