3-D shape soft magnetic composite parts can be formed by general compaction method of powder metallurgy. In this study, the results on the high density nanostructured Fe-Si/Fe composite prepared by a warm compaction method were presented. Ball-milled Fe-25 wt.%Si powder, pure Fe powder and Si-polymer were mixed and then the powder mixture was compacted at various temperatures and pressures. Pore free density of samples up to 95% theoretical value has been obtained. The warm compacted sample prepared at 650 MPa and 240℃ had highest compaction properties in comparison with other compacts prepared at 300, 400 MPa and room temperature and 120℃. The magnetic properties such as core loss, magnetization saturation and coercivity were measured by B-H curve analyzer and vibration sample magnetometer.

The friction characteristics of automotive brake friction materials that contained different ceramic content were investigated. Several kinds of raw materials, such as resin-based binder, reinforcing fiber, friction restraint, abrasive, and filling materials were mixed, pressed, and heated in order to make the brake friction materials. The contents of SiC and BaSO4 changed from 5 vol% to 20 vol%, respectively. In addition to this, the content of Al2O3 adjusted from 1 vol% to 16 vol%. The surface morphology of the SiC containing sample appeared rough while more debris was observed when the contents of SiC increased. This implies that the SiC containing brake composite was not adequate for the automobile. However, the relatively smooth surface was observed in samples that contained the Al2O3. But the roughness was low with a content of 11 vol% Al2O3 compared to the other samples. This is consistent with the abrasive properties of the samples. In the case of BaSO4 containing samples, the smoothes surface was observed in the contents of 15 vol% BaSO4. Thus, it was concluded that the 11 vol% Al2O3 and 15 vol% BaSO4 containing composite would be the optimum content for the brake composite. Similar to the results of the surface morphology, the abrasion resistance consistently decreased when the content of SiC increased. On the contrary, the sample that contained 11 vol% Al2O3 and 15 vol% BaSO4 showed the highest abrasion resistance compared to the other samples.

In this study, Ti powder was fabricated from Ti scrap by the Hydrogenation-Dehydrogenation (HDH)method. Hydrogenation reactions of Ti scrap occurred at near 450oC with a sudden increase in the reactiontemperature and the decreasing pressure of hydrogen gas during the hydrogenation process in the furnace. Thedehydrogenation process was also carried out at 750oC for 2hrs in a vacuum of 10-4torr. After the HDHprocess, a deoxidation treatment was carried out with the Ca(purity: 99.5) at 700oC for 2hrs in the vacuumsystem. It was found that the oxidation content of Ti powder that was deoxidized with Ca showed noticeablylower values, compared to the content obtained by HDH process. In order to fabricate Ti compacts, Ti powderwas sintered at 1100~1400oC for 2hrs under a vacuum of 10-4torr. The relative density of compact was 94.9%at 1300oC. After sintering, all of the Ti compacts showed brittle fracture behavior, which occurred in an elasticrange with short plastic yielding up to a peak stress.

This study was conducted to investigate the quality characteristics of tofu prepared with different concentrations of lotus leaf powder. The determined values for moisture, crude ash, carbohydrate, crude protein, and crude lipid in were 2.97%, 8.09%, 65.18%, 22.83%, and 0.93%, respectively. The yield rates of the tofu samples did not differ significantly according to the level of added lotus leaf powder; however, there was a significant decrease in pH and a significant increase in acidity. The L- and a-values of samples decreased as the amount of lotus leaf powder in the formulation increased, whereas the b value increased. Furthermore, hardness significantly increased as the level of lotus leaf powder increased. In terms of overall acceptability, the preferred tofu samples were the control and that containing 0.2% lotus leaf powder.

The compaction response of nano powders with an addition of Ti powders prepared by magnetic pulsed compaction and subsequent sintering processes was investigated. All kinds of different bulk exhibited an average shrinkage of about 12% for different MPCed pressure and sintering temperature, which were approximately 50% lower than those fabricated by general process (20%) and a maximum density of around 92.7% was obtained for 0.8GPa MPCed pressure and sintering temperature. The addition of Ti powder induced an increase in the formability and hardness of the sintered . But the lower densities were obtained on sintering with addition of over 10 (wt%) Ti powder due to generation of crack during sintering. Subsequently it was verified that the optimum compaction pressure in MPC and sintering temperature were 0.8GPa and , respectively

팽화미분을 활용한 타락죽의 제품화를 위한 기초자료를 제공하기 위해서 팽화미분 첨가에 따른 타락죽의 pH, 수분, 고형분, 총당, 아밀로스, 점도, 퍼짐성 그리고 색도 변화를 조사하였다. 타락죽의 pH는 갈은 쌀로 제조한 시료가 팽화미분으로 제조한 시료보다 높았다. 그리고 분유를 첨가한 시료도 우유를 첨가한 시료보다 높았다(p<0.05). 수분 함량은 갈은 쌀과 분유를 혼합한 타락죽이 84.56%로 가장 높았고, 팽화미분과 우유를 혼합한 타락죽은 81.04%로 가장 낮았다(p<0.05). 고형분 함량은 수분함량과 반대되는 결과를 보였다(p<0.05). 총당 함량은 조리 시 가열처리한 시료 사이에서 유의적인 차이가 없었고 가열처리하지 않은 시료보다 높았다(p<0.05). 팽화미분으로 제조한 타락죽의 아밀로스 함량이 갈은 쌀로 제조한 타락죽보다 높았다(p<0.05). 점도는 갈은 쌀 타락죽이 팽화미분 타락죽보다 높았으며(p<0.05) 아밀로스 함량과 반비례하는 결과를 보였다. 퍼짐성은 점도와 상반되는 결과를 보였다(p<0.05). L값은 갈은 쌀 타락죽이 팽화미분 타락죽보다 높았다. 적색도는 팽화미분 타락죽이 가장 높았으며(p<0.05), 갈은 쌀과 우유를 혼합한 시료가 가장 낮게 나타나 L값과 반대되는 결과를 보였다. 황색도는 a값과 유사한 경향을 보였다.

함초의 저장성을 향상시키고 이를 기능성 부재료로 활용하기 위한 기초실험자료를 제공하고자 함초를 열풍건조, 진공건조 및 동결건조 등 건조방법을 달리하여 분말을 제조한 후 각 시료의 물리화학적 분말특성을 비교 검토하였다. 열풍건조하여 제조한 시료의 수분함량이 3.16%로 가장 낮았으며, 진공건조 분말이 3.42%, 동결건조 분말이 3.80%로 나타났으며 시료의 pH는 6.12-6.27의 범위값을 나타내었다. 동결건조한 시료의 명도는 다른 시료들과 비교하여 가장 높았고 적색도는 가장 낮게 나타났다(p<0.05). 주사전자현미경을 이용한 미세구조 관찰결과 동결건조된 시료의 입자가 보다 규칙적이고 치밀하게 배열된 것으로 관찰되었으나, 다공성구조는 관측되지 않았다. 또한 동결건조된 시료의 수분 용해도는 다른 시료들과 비교하여 가장 높은 반면 팽윤력은 가장 낮은 것으로 나타났다(p<0.05). 한편 총당 및 환원당의 함량은 동결건조한 시료가 가장 많은 것으로 나타났다(p<0.05).

딸기 분말의 대체량을 0-6%로 달리하여 쿠키를 제조한 후 물리화학적 품질특성을 측정하고 각 특성사이의 상관관계를 살펴보았다. 딸기 분말 대체량이 증가함에 따라 반죽의 pH와 쿠키의 경도는 유의적으로 감소하였다(p<0.05). 반죽의 수분함량은 딸기 분말의 대체에 따라 유의적인 차이를 나타내지는 않았지만 평균 수분함량은 증가하는 경향을 나타내었다. 딸기 분말의 대체량이 증가할수록 명도와 황색도는 유의적으로 감소한 반면 적색도는 증가하였다(p<0.05). 퍼짐성 지수 역시 유의적인 증가를 나타내었다(p<0.05). 한편 상관분석결과 딸기 분말 대체수준은 모든 물리화학적 품질특성과 유의적인 상관관계를 나타내었다. 또한 반죽의 수분함량과 퍼짐성 지수 사이에 양의 유의적 상관관계가 관측되었다(p<0.05).

In this study, we attempted to develop a convenient aluminizing process, using Al-Ti mixed slurry as an aluminum source, to control the Al content of the aluminized layer as a result of a one-step process and can be widely adopted for coating complex-shaped components. The aluminizing process was carried out by the heat treatment on disc and rod shaped S45C steel substrates with Al-Ti mixed slurries that were composed of various mixed ratios (wt%) of Al and Ti powders. The surface of the resultant aluminized layer was relatively smooth with no obvious cracks. The aluminized layers mainly contain an Fe-Al compound as the bulk phase. However, the Al concentration and the thickness of the aluminized layer gradually decrease as the Ti proportion among Al-Ti mixed slurries increases. It has also been shown that the Al-Ti compound layer, which formed on the substrate during heat treatment, easily separates from the substrate. In addition, the incorporation of Ti into the substrate surface during heat treatment was not observed.

The purpose of this study was to investigate the quality characteristics of cookies prepared with shrimp powder (0, 3, 5, 7, 9%) substituted for flour as a snack food for Kindergarteners. The pH of the cookie dough decreased significantly in response to the addition of all levels of shrimp powder. However, there were no significant differences in the dough values among the test groups. Furthermore, when the spread factor values were compared among groups, they were found to be inversely proportional to the shrimp powder concentration. In addition, the Hunter's color L, a and b values decreased significantly as the level of shrimp powder increased. Moreover, the addition of 3~9% shrimp powder resulted in increased hardness, cohesiveness, springiness, and brittleness when compared to the control. Finally, the results of acceptance test showed that the cookies containing 5% shrimp powder had the highest scores.

The objective of this study was to investigate the effects of different amounts of pumpkin powder on the quality characteristics of hobakpyeon using physicochemical and sensory properties, as well as on its retrogradation rate during storage. As the amount of pumpkin powder increased, the following effects on the quality characteristics were observed: moisture and amylose contents decreased while protein content increased (p<0.05), and in vitro protein digestibility (IVPD) decreased (p<0.05). Levels of slowly digestible starch and resistant starch fractions increased, while the content of rapidly digestible starch decreased. The starch digestion index and rapidly available glucose content also decreased. Among the physical properties, the L-value decreased while the b-value increased (p<0.05). Texture profile analysis revealed that all textural properties except adhesiveness decreased, and presented significant differences in hardness and chewiness (p<0.05). Sensory properties such as color, flavor, and sweetness increased while others such as wetness and chewiness decreased (p<0.05). Effects on the physicochemical properties during refrigerated storage were also compared between the control and 9% hobakpyeon (9%HP). According to the results, moisture content gradually decreased in the 9%HP compared to the control. Amylose content significantly increased in 9%HP whereas no significant changes were observed in the control. In both types of hobakpyeon, IVSD decreased significantly, showing higher values in 9%HP, whereas mechanical hardness increased, showing lower values in 9%HP. The L-value decreased significantly in the 9%HP whereas no significant changes were observed in the control. In conclusion, the above results suggest that hobakpyeon with low IVSD may be obtained by the addition of 9% pumpkin powder, and also showed that pumpkin powder delayed the rate of retrogradation in 9%HP during storage.

The effects of thermal treatment conditions on ADU (ammonium diuranate) prepared by SOL-GEL method, so-called GSP (Gel supported precipitation) process, were investigated for kernel preparation. In this study, ADU compound particles were calcined to particles in air and Ar atmospheres, and these particles were reduced and sintered in 4%-/Ar. During the thermal calcining treatment in air, ADU compound was slightly decomposed, and then converted to phases at . At , the phase appeared together with . After sintering of theses particles, the uranium oxide phases were reduced to a stoichiometric . As a result of the calcining treatment in Ar, more reduced-form of uranium oxide was observed than that treated in air atmosphere by XRD analysis. The final phases of these particles were estimated as a mixture of and .

Niobium powder was made from potassium heptafluoroniobite () as the raw material using sodium (Na) as a reducing agent based on the hunter process. The apparatus for the experiment was designed and built specifically for the present study. The niobium particle size greatly increased as the reduction temperature increased from to . The particle size was fairly uniform, varying from to depending on the reduction temperatures. The niobium powder morphology and particle size are very sensitive to a reaction temperature in the metallothermic reduction process. The yield of niobium powder increased from 55% to 80% with a increasing a reaction temperature.

In chemistry, the study of sonochemistry is concerned with understanding the effect of sonic waves and wave properties on chemical systems. In the area of chemical kinetics, it has been observed that ultrasound can greatly enhance chemical reactivity in a number of systems by as much as a million-fold. Nano-technology is a super microscopic technology in which structures of 100 nanometers or smaller can be investigated. This technology has been used to develop TiO2 materials and TiO2 devices of that size. Thus far, electrochemistry methods and photochemistry methods have generally been used to create TiO2 nano-size particles. However, these methods are complicated and create pollutants as a by-product. In the present study, nano-scale silver particles (5 nm) were prepared in a sonochemistry method. Sonochemistry deals with mechanical energy that is provided by the collapse of cavitation bubbles that form in solutions during exposure to ultrasound. TiO2 powders 25 nm in size doped with Ag were formed using an ultrasonic sound technique. The experimental results showed the high possibility of removing pollution through the action of a photocatalyst. This powder synthesis technique can be considered as an environmentally friendly powder-forming processing owing to its energy saving characteristics.

In this study, Ti powder was fabricated from Ti scrap by a hydrogenation-dehydrogenation (HDH)method. The Ti powders were compacted by Spark plasma sintering (SPS) and the microstructure andmechanical properties of the powders were investigated. A hydrogenation reaction of Ti scrap occurred attemperatures near 450oC with a sudden increase in the reaction temperature and a decrease in the pressureof the hydrogen gas as measured in a furnace during the hydrogenation process. In addition, a dehydrogenationprocess was carried out at 750oC for 2hrs in a vacuum of 10-4torr. The Ti powder sizes obtained byhydrogenation-dehydrogenation and mechanical milling processes were in the range of 1~90µm and 1~100µm,respectively. To fabricate Ti compacts, Ti powders were sintered under an applied uniaxial punch pressure of40 MPa at in a range of 900~1200oC for 5 min. The relative density of a SPSed compact was 99.6% at 1100oC,and the tensile strength decreased with an increase in the sintering temperature. However, the hardnessincreased as the sintering temperature increased.