High speed steels (HSS) were used as cutting tools and wear parts, because of high strength, wear resistance, and hardness together with an appreciable toughness and fatigue resistance. Conventional manufacturing process for production of components with HSS was used by casting. The powder metallurgy techniques were currently developed due to second phase segregation of conventional process. The powder injection molding method (PIM) was received attention owing to shape without additional processes. The experimental specimens were manufactured with T42 HSS powders (59 vol%) and polymer (41 vol%). The metal powders were prealloyed water-atomised T42 HSS. The green parts were solvent debinded in normal n-Hexane at for 24 hours and thermal debinded at mixed gas atmosphere for 14 hours. Specimens were sintered in , gas atmosphere and vacuum condition between 1200 and . In result, polymer degradation temperatures about optimum conditions were found at and . After sintering at gas atmosphere, maximum hardness of 310Hv was observed at . Fine and well dispersed carbide were observed at this condition. But relative density was under 90%. When sintering at gas atmosphere, relative density was observed to 94.5% at . However, the low hardness was obtained due to decarbonization by hydrogen. In case of sintering at the vacuum of torr at temperature of , full density and 550Hv hardness were obtained without precipitation of MC and in grain boundary.

In this research, the refinement behavior of the coarse magnesium powders fabricated by gas atomization was investigated as a function of milling time using a short duration high-energy ball milling equipment, which produces fine powders by means of an ultra high-energy within a short duration. The microstructure, hardness, and formability of the powders were investigated as a function of milling time using X-ray diffraction, scanning electron microscopy, Vickers micro-hardness tester and magnetic pulsed compaction. The particle morphology of Mg powders changed from spherical particles of feed metals to irregular oval particles, then platetype particles, with increasing milling time. Due to having HCP structure, deformation occurs due to the existence of the easily breakable C-axis perpendicular to the base, resulting in producing plate-type powders. With increasing milling time, the particle size increased until 5 minutes, then decreased gradually reaching a uniform size of about 50 micrometer after 20 minutes. The relative density of the initial power was 98% before milling, and mechanically milled powder was 92~94% with increase milling time (1~5 min) then it increased to 99% after milling for 20 minutes because of the change in particle shapes.

This study evaluated the quality and sensory characteristics of sulgidduk added with yam powder (5~20%) during 4 days storage. The moisture content of samples initially decreased as the yam powder content increased, but subsequently increased during storage. The pH values also increased during storage, although there was no significant difference. L values decreased and both a and b values increased as yam powder content increased. The decreased L values during storage were not significantly different from control group. The hardness of samples decreased with increasing yam powder content, while hardness of control group markedly increased during storage. Cohesiveness increased as yam powder content increased, and tended to decrease during the storage. Springiness also initially increased as yam powder content increased. No change was apparent during storage in control group or samples added with up to 10% yam powder, while springiness was decreased insignificantly in samples with over 10% yam powder. Lightness, yam odor and savory taste of sulgidduk tended to increase as yam powder content increased, while chewiness decreased. The savory odor was the highest in sulgidduk added with 10% yam powder. Sulgidduk added with 10% yam powder was the most preferred in appearance, taste, texture and overall preference.

In this research, the optimal manufacturing conditions of fine Si powders from Si scrap were investigated as a function of different initial powder size using the high-energy ball milling equipment, which produces the fine powder by means of an ultra high-energy within a short duration. The morphological change of the powders according to the milling time was observed by Scanning electron microscopy (SEM). With the increasing milling time, the size of Si powder was decreased. In addition, more energy and stress for milling were required with the decreasing initial powder size. The refinement of Si scrap was rapidly carried out at 10min ball milling time. However, the refined powder started to agglomerate at 30 min milling time, while the powder size became uniform at 60 min milling time.

The principal objective of this study was to evaluate quality characteristics of dried noodles when different concentrations of lotus leaf powder (LLP) were added to the wheat flour, thereby determining which noodle recipe was preferred. The cooking quality, mechanical texture properties, and viscosity were measured, and then a sensory evaluation was conducted with the prepared noodles. The gelatinization points of the composite LLP-wheat flours were shown to have an increased, viscosity at 95oC after 15 minutes. As measured via amylograph, the maximum viscosity values of those samples were decreased as the LLP content was increased. As well, when increased amounts of LLP were added, both the L and a values were reduced, whereas the b value was increased. The color values, weight and volume of the cooked noodle increased, as did the turbidity of the soup. With regard to the textural characteristics, the LLP additive increased hardness and cohesiveness, and reduced adhesiveness and springiness. Overall, according to the results of our sensory evaluation, the noodles prepared with 5% LLP were preferred over the other noodles.

아스파라거스 동결건조 분말을 박력분 중량에 대하여 0, 0.5, 1, 2, 3 및 5% (w/w) 첨가하여 제조한 쿠키의 품질특성을 분석하였다. 반죽의 pH는 아스파라거스 분말을 5% 첨가한 시료에서 유의적으로 낮아 6.26였으며, 반죽의 밀도는 아스파라거스 분말 첨가량의 증가에 따라 감소하는 경향을 보여, 아스파라거스 분말 5% 첨가 군에서는 1.02 g/mL로 유의적으로 낮았다. 평균직경에 대한 너비의 비로부터 산출한 퍼짐성 지수는 아스파라 거스 분말 첨가량이 높아질수록 유의적으로 증가하는 경향이었다. 쿠키의 경도도 퍼짐성 지수와 동일한 경향 으로 5% 아스파라거스 분말 첨가군에서 4545.17 g로 가장 높게 나타났다. 반죽의 L값은 아스파라거스 분말 0.5% 첨가시 80.78로 대조군과 차이가 없었으나 아스파라거스 분말의 첨가량이 증가할수록 감소하여 5% 첨 가시에는 74.56으로 낮아졌다. a값은 L값과 유사한 경향이었으나, b값은 반대로 대조구 (30.37)가 가장 낮았고, 아스파라거스 분말의 첨가량이 증가할수록 점차 증가하여 5% 첨가구에서 37.80으로 가장 높게 나타났다. 소 성 후 쿠키의 L값은 아스파라거스 분말의 첨가량이 증가할수록 유의적으로 감소해 5% 첨가군의 경우 55.38 로 가장 낮았고, a값은 대조군보다 아스파라거스 분말 첨가군에서 더 낮았으나 첨가 비율에 따른 유의차는 없었다. 쿠키의 관능적 특성은 평가 항목 모두 대조군과 실험군간에 통계적인 유의차가 없어 쿠키 제조시 아 스파라거스 분말을 5%까지 첨가하여도 쿠키의 품질특성에는 큰 영향을 미치지 않음을 확인 할 수 있었다.

마늘 분말을 첨가한 요구르트의 품질특성 평가를 위하여 탈지분유에 0.1~0.5%(w/v) 마늘 분말을 혼합하고 Streptococcus thermophilus와 Lactobacillus delbrueckii subsp. bulgaricus의 혼합균주를 접종하여 42℃ 에서 24시간 배양하였다. 마늘 분말 첨가량에 따른 유산균의 생육정도, 요구르트의 이화학적 및 관능적 특성 을 검토하였다. 마늘 분말이 첨가된 요구르트의 적정산도는 0.78~0.81%로 마늘 분말이 첨가되지 않은 대조 군(0.73%)보다 높았다. 마늘 분말을 첨가한 요구르트의 생균수는 0.3% 첨가군에서만 상대적으로 낮았고 여 타 실험군은 대조군과 유의적인 차이가 없었다. 마늘분말의 첨가량이 증가함에 따라 요구르트의 점도도 상승 하여 0.5% 마늘 분말이 첨가된 요구르트의 점도가 가장 높았으며, 색도는 대조군과 마늘 분말 첨가 요구르트 사이에 유의적인 차이가 없었다. 관능적 특성을 조사한 결과 마늘 분말의 첨가에 따라 색은 더 높은 선호도를 보였고, 마늘 맛이나 향은 마늘 분말의 첨가량에 비례적으로 증가하였으며, 전반적인 기호도는 0.1%와 0.3% 첨가시는 대조군과 유의차가 없었다. 이상의 결과를 종합하여 볼 때 요구르트 고유의 품질특성이나 유산균의 생육 및 관능적 특성에 영향을 미치지 않는 범위에서 첨가 가능한 마늘 분말의 적정 수준은 0.3% 미만으로 판단된다.

In this study, the sintering behavior of (Nd, Dy)-Fe-B powder which fabricated by strip-casting was investigated with various sintering temperatures and holding times. The relative density over 99% could be obtained by both sintering at for 1h and sintering at for 20h. The grain growth was observed in sintered specimen at compared to one at . The isothermal sintering process below led to suppress grain growth showing the improved magnetic properties. The phase transformation of Nd-rich was confirmed by X-ray diffraction pattern.

Sm-16.7wt%Co alloy powders were prepared by high energy ball milling under the conditions of various milling time and the content of process control agent (PCA), and their microstructure and magnetic properties were investigated to establish optimum processing conditions. The initial powders employed showed irregular shape and had a size ranging from 5 to . After milling for 5 h, the shape of powders changed to round shape and their mean powder size was approximately , which consisted of the agglomerated nano-sized particles with 15 nm in diameter. The coercivity was reduced with increasing the milling time, whereas the saturation magnetization increased. As the content of PCA increased, the powder size minutely decreased to approximately at the PCA content of 10 wt%. The XRD patterns showed that the main diffraction peaks disappeared apparently after milling, indicating the formation of amorphous structure. The measured values of coercivity were almost unchanged with increasing the content of PCA.

In this study, Ti powders were fabricated from Ti scrap by the Hydrogenation-Dehydrogenation (HDH) method.The Ti powders were prepared from the spark plasma sintering (SPS) and their microstructure was investigated.Hydrogenation reactions of Ti scrap occurred at near 450oC with a sudden increase in the reaction temperature and thedecreasing pressure of hydrogen gas during the hydrogenation process in the furnace. The dehydrogenation process was alsocarried out at 750oC for 2 hrs in a vacuum of 10-4torr. After the HDH process, deoxidation treatment was carried out withthe Ca (purity: 99.5%) at 700oC for 2 hrs in the vacuum system. It was found that the oxidation content of Ti powder thatwas deoxidized with Ca showed noticeably lower values, compared to the content obtained by the HDH process. In orderto fabricate the Ti compacts, Ti powder was sintered under an applied uniaxial punch pressure of 40 MPa in the range of900-1200oC for 5 min under a vacuum of 10-4torr. The relative density of the compact was 99.5% at 1100oC and the tensilestrength decreased with increasing sintering temperature. After sintering, all of the Ti compacts showed brittle fracturebehavior, which occurred in an elastic range with short plastic yielding up to a peak stress. Ti improved the corrosionresistance of the Ti compacts, and the Pd powders were mixed with the HDH Ti powders.

Freeze-dried broccoli powder was incorporated into cookie dough at 5 levels (0, 1, 2, 3, and 4%, w/w) by replacing equivalent amount of wheat flour of the cookie dough. After aging and sheeting, cookies were baked at 170oC for 8 min in an oven. The baked cookies were cooled to room temperature for 1 hr and packed in airtight bags prior to all measurements. The pH and moisture content were ranged 6.74-6.90 and 2.67-4.12% (wet basis) depending on the broccoli powder level, respectively. Lightness (L*-value), redness (a*-value), and hardness decreased while yellowness (b*-value) increased significantly as the broccoli powder content increased (p<0.05). Spread factor of the control was significantly lower than that of samples containing broccoli powder regardless of the concentration (p<0.05) and increased significantly with increase in broccoli powder content (p<0.05). The broccoli concentration correlated significantly with most of properties except for pH and spread factor (p<0.05 or p<0.01). Hardness correlated negatively with moisture content (p<0.05) but correlated positively with spread factor (p<0.01).

In this work, effect of various process-control agents (PCAs) on the mechanical alloying of amorphous alloy of has been investigated. The dependence of the particle shape, size and crystallization behavior of the amorphous alloy powders on the type of PCAs and their concentrations was investigated by using X-ray diffraction, field-emission scanning electron microscopy and differential scanning calorimetry. It was found that the additive of toluene could affect positively the amorphization and thermally induced crystallization processes, as well as the size refinement, morphology and particle-size distribution of as-milled powders in comparison with alloy obtained without PCA.

8 mol% Y-doped powder was synthesized by Pechini method from titanium isopropoxide, strontium nitrate, yttrium nitrate, citric acid and ethylene glycol. A pyrochlore phase-free perovskite powder was obtained by calcining a polymeric resin, which was prepared from a precursor solution, at in an air atmosphere. Low temperature calcination could lead to a fine-grained microstructure. In the case of a solid-state reaction, an extended heat-treatment at high temperature in a reduced atmosphere needed to obtain a single phase perovskite .

Geopolymer materials are attractive as inorganic binders due to their superior mechanical and eco-friendly properties. In the current study, geopolymer-based cement was prepared using aluminosilicate minerals from fly-ash with KOH as an alkaline-activator and Na2SiO3 as liquid glass. Then, calcium carbonate powder from a clam shell was mixed with the geopolymer and the mixture was coated on a concrete surface to provide points of attachment for environmental organisms to grow on the geopolymers. We investigated the effect of the shell powder grain size on the microstructure and bonding property of the geopolymers. A homogeneous geopolymer layer coated well on the concrete surface via aluminosilicate bonding, but the adhesiveness of the shell powder on the geopolymer cement was dependent on the grain size of the shell powder. Superior adhesive characteristics were shown in the shell powder of large grain size due to the deep penetration into the geopolymer by their large weight. This kind of coating can be applied to the adhesiveness of eco-materials on the surface of seaside or riverside blocks.

The objective of this study was to assess the quality characteristics of almond Dasik prepared with the addition of purple sweet potato powder (PSPP). Five different levels (0, 5, 10, 15, and 20%) of PSPP were added and the physicochemical properties of the Dasik were examined. Crude protein and crude fat contents decreased as the level of PSPP increased (p<0.05). The Hunter L-value decreased while the a-value increased as the PSPP level increased. Texture measurements showed that the addition of PSPP increased hardness, cohesiveness, and brittleness. Total polyphenol content and antioxidant activity were assessed in terms of estimating the functionality of the Dasik. The results showed that incorporating PSPP into the Dasik provided higher polyphenol content and antioxidant activity compared to the control Dasik (p<0.05). The results of a consumer acceptance test revealed that the Dasik sample made with 15% PSPP was most preferred and the 20% sample was the least preferred. Therefore, it is suggested that purple sweet potato powder can be incorporated into Dasik up to 15% without reducing its quality.

We investigated the chemical components of red onion powder dried using the low temperature vacuum method and the inhibitory effects of solvent extracts of the dried red onion powder on the growth of HT-1080 human fibrosarcoma and HT- 29 human colon cancer cells and H2O2-induced oxidative stress. The moisture content of the dried red onion powder was 17.95%, while the vitamin C content was 96 mg/100 g and the total phenols content was 39.1 mg/mL. The inhibitory effects of acetone with methylene chloride (A+M) and methanol (MeOH) extracts of the red onion powder on the growth of HT- 1080 and HT-29 cancer cells increased in a dose dependent manner (p<0.05). The inhibitory effect was greater on the growth of HT-29 cells, while the A+M extracts had a higher inhibitory effect than the MeOH extracts. Treatment with the hexane, 85% aq. methanol, butanol and water fractions of the extract led to significant inhibition of the growth of both cancer cell lines (p<0.05). Among the fractions, the hexane and 85% aq. methanol fractions showed a greater inhibitory effect. To determine the protective effect on H2O2-induced oxidative stress, a DCFH-DA (dichlorodihydrofluorescin diacetate) assay was conducted. All fractions, including the crude extracts of dried red onion, appeared to lead to a significant reduction in the levels of intracellular reactive oxygen species (ROS), and these reductions occurred in a dose dependent fashion (p<0.05). Among the fractions, the 85% methanol fraction showed the greatest protective effect on the production of lipid peroxides.

Mg-Cu composites were successively fabricated using a combination of rapid solidification and extrusion processes. In addition, the microstructural variation of the composite was investigated by performing the extrusion repeatedly. It resulted that the composite formed an uniform and dense structure by the extrusion, and the microstructure became fine as the extrusion conducted repeatedly. The microstructural variation was known to be dependent on the number of extrusion and the area reduction ratio. The tensile strength was also measured as a function of the microstructural variation.