Effect of Cu and powder mixing with Cu-free (Nd, Dy)-Fe-B jet-milled powder on the magnetic properties of sintered magnets was investigated. The coercivity of a magnet prepared from the Cu-free (Nd, Dy)-Fe-B powder was about 10 kOe even though the alloy powder already contained some Dy (3.5 wt%). When small copper powder was blended, however, the coercivity of the magnet increased almost 100%, exhibiting about 20 kOe. On the contrary, the coercivity enhancement was moderate, about 4 kOe, when dysprosium content in the sintered magnet was simply increased to 4.9 wt% by the addition of small 3 powder.

PURPOSES : This study is to investigate the fundamental properties of limestone added cement concrete for application of pavement. METHODS : As the production of Portland cement causes environmental problems, engineers have sought more environment-friendly concrete construction materials. Limestone powder can be used for concrete as a partial replacement of Portland cement. One of the great applications of limestone powder added cement concrete might be a cement concrete pavement since the concrete pavement consumes massive quantity of Portland cement. Experimental variables were different replacement level of limestone powder by 0% to 25% with 5% increment. Before hardening of fresh concrete, setting time and plastic shrinkage characteristics were investigated in addition to other basic properties. Properties of hardened concrete included compressive, tensile and flexural strength as well as drying shrinkage. RESULTS : The addition of limestone powder did not significantly affect the properties of fresh concrete. Strength deceased as the replacement ratio increased and when the replacement ratio was greater than 10% decrease rate increased. CONCLUSIONS : It was found that the partial replacement of the limestone powder to cement in pavement materials can be positively considered as its mechanical properties show comparable performance to those normal concrete.

We investigated the quality characteristics of cookies prepared after the addition of various concentration of used guava leaf powder(0%, 1%, 3%, 5%, all w/w) as a substitute for flour. In this study, as guava leaf powder concentration rose, there was a decrease in the water content level. In addition, color, spread factor, hardness and sensory evaluation of the cookies were examined. The results showed that with an increase in guava leaf powder concentration, the L value decreased significantly, while the values for a and b of cookies increased when more guava leaf power was added to cookies. The spread factor of cookies decreased, but the hardness of cookies increased significantly, as guava leaf powder concentration increased. Cookies containing 0% and 3% of guava leaf powder showed a similar sensory evaluation score in terms of color, taste and flavor of the cookies. In the case of texture and overall consumer acceptability, cookies with 3% of guava leaf powder showed the highest score.

In this study, the experimental method has been investigated using molecular biological way to identify raw materials from seasoned red-pepper sauce which is one of the most popular spices in Korea. 6 kinds of seasoned red-pepper sauces were chosen as a sample containing chilli pepper, garlic, onion as a major ingredient and species specific primers were used for the identification of the raw material of processed food. Selected samples were pre-treated to remove salt (samples were washed with distilled water 3~4 times for desalting), after that, to amplify the extracted genes, whole genome amplification (WGA) kit was performed. Afterwards, PCR products were confirmed through the electrophoresis. As a result, 102, 180, 280 bp of specific PCR products were confirmed for each major ingredients such as chilli pepper, garlic, onion. From this study, the gene extraction method was validated for the identification of ingredients from the spices and it would be applied to distinction of low quality chilli pepper powder including seasoned red-pepper sauce illegally.

In this research, the coating behavior of Mg and Fe desulfurization powder fabricated by low energy and conventional planetary mill equipment was investigated as a function of milling time, which produces uniform Fe coated powders due to milling energy. Since high energy ball milling results in breaking the Fe coated Mg powders into coarse particles, low energy ball milling was considered appropriate for this study, and can be implemented in desulfurization industry widely. XRD and FE-SEM analyses were carried out to investigate the microstructure and distribution of the coating material. The thickness of the Fe coating layer reaches a maximum of 14 at 20 milling hours. The BCC structures of Fe particles are deformed due to the slip system of Fe coated Mg particles.

An attempt was made to evaluate creep reliability of two commercial Ni-based superalloys by using ultrasonic wave. The materials include fine-grained PM alloy fabricated by mechanical alloying and subsequent hot isostatic pressing, and IN738LC cast alloy with a grain size of a few cm. Microstructural parameters (fraction of creep cavity and size of precipitates) and ultrasonic parameters (velocity, attenuation) were measured to try to find relationships between them. Ultrasonic velocity decreased with creep cavity formation in PM alloy. On the other hand, no distinct changing trend of ultrasonic velocity was observed for IN738LC alloy. Ultrasonic attenuation was found to have a linear correlation with the size of precipitates and was suggested as a potential parameter for monitoring creep reliability of IN738LC alloy.

Roll milled- and nano-powders were prepared from the freeze dried fruiting bodies of Hericium erinaceum and their hydration properties such as water solubility index, swelling capacity, water holding capacity, and water sorption isotherm were compared. Water content in freeze dried Nano-powder of Hericium erinaceum fruiting body was 8.17%. Nano-powder has higher water solubility index compared to roll mill powder by 58.41% and 39.06%, respectively. In the same way, swelling capacity of nano-powder was 10.21ml/g where as roll mill powder has only 4.42ml/g. In contrast, water holding capacity of nano-powder (3.87g/g) is lower than that of roll mill powder (6.81g/g). Water sorption isotherm of these powders was compared and the result shows no big difference at low relative humidity (below75%). However, a high relative humidity above 75%, these two kinds of powder showed comparable difference. At 84.34% relative humidity, roll mill powder has 30.41% of moisture content compared with 47.64% of nano-powder, and at the relative humidity of 97.3%, the moisture content of roll mill and nano-powder are 37.64% and 91.06% respectively.

고춧가루의 품질 변화를 낮추면서 살균하는 기술을 개발하고자 감압방전플라즈마(LPDP)를 이용한 비가열살균을 시도하였고 LPDP 처리에 의한 품질변화를 조사하였다. 시중 판매 고춧가루의 오염도는 세균 7.33×104-1.07×107 CFU/g, 진균류 3.47×104-3.16×106 CFU/g의 범위를 보여 상당한 수준으로 오염된 식품으로 확인되었다. 고춧가루의 LPDP 살균 패턴은 2단계 1차 반응으로 나타났으며, 출력에 따라 살균속도상수가 증가하였다. 또한 입자가 가늘수록 살균효과가 증가하였으며, 미생물 종류별로는 세균에 비하여 진균에 대한 살균효과가 크게 나타났다. 과도한 LPDP 처리는 고춧가루의 탈색과 capsaicinoids 함량의 감소를 유발하였다. LPDP 처리 고춧가루를 사용하여 조리한 무채의 관능검사 결과 색과 맛은 5분 처리까지는 무처리구와 차이가 없었으나 10분 처리 시에는 유의하게 낮은 점수를 보였다. 반면 향과 기호도에서는 처리구와 무처리구 간에 유의차를 보이지 않아 5분 이하로 LPDP 처리 시 관능특성을 유지하면서 약 1.5 log 정도의 미생물 저감화가 가능하였다.

Optimal conditions for HA plasma spray-coating on Ti6Al4V alloy were investigated in order to obtain enhanced bone-bonding ability with Ti6Al4V alloy. The properties of plasma spray coated film were analyzed by SEM, XRD, surface roughness measurement, and adhesion strength test because the film's transformed phase and crystallinity were known to be influential to bone-bonding ability withTi6Al4V alloy. The films were formed by a plasma spray coating technique with various combinations of plasma power, spray distance, and auxiliary He gas pressure. The film properties were analyzed in order to determine the optimal spray coating parameters with which we will able to achieve enhanced bone-bonding ability with Ti6Al4V alloy. The most influential coating parameter was found to be the plasma spray distance to the specimen from the spray gun nozzle. Additionally, it was observed that a relatively higher film crystallinity can be obtained with lower auxiliary gas pressure. Moderate adhesion strength can be achievable at minimal plasma power. That is, adhesion strength is minimally dependent on the plasma power. The combination of shorter spray distance, lower auxiliary gas pressure, and moderate spray power can be recommended as the optimal spray conditions. In this study, optimal plasma spray coated films were formed with spray distance of 70 mm, plasma current of 800 A, and auxiliary gas pressure of 60 psi.

The purpose of this study was to bake sweet rice muffins with oak mushroom (Lentinus edodes) powder. The process included substituting sweet rice flour for cake flour and adding oak mushroom powder. This study determined the optimal mixing conditions of oak mushroom muffins by adjusting the amounts of oak mushroom powder, whole eggs, and soybean oil. The mixing conditions for the oak mushroom muffins included 3 categories: oak mushroom powder (X1), whole eggs (X2), and soybean oil (X3) by Central Composite Design (CCD) which was optimized by Response Surface Methodology (RSM). Oak mushroom muffin formulation was optimized using rheology. Yellowness (p〈0.001) and redness (p〈0.05) displayed a linear model pattern, whereas lightness (p〈0.05) was represented by a quadratic model. Among the sensory properties, variables that appeared to show significant values such as appearance (p〈0.5), texture (p〈0.5), and overall quality (p〈0.5) were used to identify optimums. The result of mechanical properties showed significant values in gumminess (p〈0.5) and chewiness (p〈0.5). The numerical and graphical methods used in this study determined that the optimum formulation for oak mushroom powder sweet rice muffins was 8.75 g of oak mushroom powder, 235.95 g of whole eggs, and 19.93 g of soybean oil.

본 실험은 호박분말 급여가 돈육의 품질 특성에 미치는 영향을 조사하기 위하여 평균 개시체중 64.5 kg인 총 20두의 3원 교잡종(Landrace×Yorkshire×Duroc)을 대상으로 호박분말 급여량을 0, 2, 5 및 7%로 처리구별 5두씩 공시하여 출하전 30일간 급여하였다. 호박분말 급여구에서 높은 수분 함량 및 조지방 함량을 나타내었다. 명도(lightness) 값은 처리구들 간 유의적인 차이가 나타나지 않았으나(p>0.05), 적색도(redness)는 2% 및 7% 호박분말 급여구가 대조구에 비해 유의적으로 높은 값을 나타내었다. 육즙 및 가열감량은 모든 처리구에서 유의적인 차이가 없었으나, 5% 호박분말 급여구에서 높은 pH 및 모든 호박분말 급여구에서 낮은 전단가 값을 나타내었다. 호박분말 급여구에서 대조구에 비해 낮은 콜레스테롤 함량을 보이며, 호박분말 급여수준이 증가할수록 콜레스테롤 함량이 감소하였다. 또한 호박분말 급여구에서 높은 myristic acid(C14:0) 함량을 보인 반면, 2% 및 5% 호박분말 급여구에서 높은 palmitoleic acid(C16:1) 함량 나타내었다. 따라서 호박분말 급여는 돈육의 사후 pH와 수분함량을 높이고, 전단가 및 콜레스테롤 함량을 감소시키는 등 돈육 품질을 개선시키는 것으로 나타났다.

FRP products have been widely used in various fields of industry because of possessing high-strengths, corrosion resistance. Accordingly the waste FRP have also been increased and the effective recycling methods of waste FRP are needed. In this study, polymer mortar specimens were prepared with the various substitution amount of waste FRP powder. For finding the mechanical properties of polymer mortar added with waste FRP powder, compressive strength tests are conducted. From the test, we could find that compressive strength was increased with respect to the amount of waste FRP powder.

Tool steels serve a large range of applications including hot and cold workings of metals and injection mouldings of plastics or light alloys. The high speed steels (HSS) are specifically used as cutting tools and wear parts because it has high strength, wear resistance and hardness along with appreciable toughness and fatigue resistance. From the view of HSS microstructure, it can be described as metallic matrix composites formed by a ferrous with a dispersion of hard and wear resistant carbides. The experimental specimens were manufactured using the PIM with T42 powders (50~80 vol.%) and polymer (20~50 vol.%). The green parts were debinded in n-hexane solution at for 8 hours and thermal debinded at an mixed gas atmosphere for 8 hours. Specimens were sintered in high vacuum ( Torr) and various temperatures.

This research focused on the effects of adding Hizikia fusiforme to Jeolpyun. We were able to demonstrate in this study that Jeolpyun after the addition of Hizikia fusiforme had the potential to become a functional food. Jeolpyun with 0, 2, 4, 6, and 8% of Hizikia fusiforme was analyzed by water content, color, sensory and textural characteristics immediately after production and one day later. The five different types of Jeolpyun did not show any significant differences in water content. However, all the Jeolpyun with Hizikia fusiforme showed slightly higher water retention ratio than the control after storage. As the result of Hunter's color values, lightness decreased significantly as the amount of Hizikia fusiforme increased. Redness increased in the Jeolpyun with Hizikia fusiforme compared with the control. Yellowness was highest in the Jeolpyun with 2% of Hizikia fusiforme and decreased with an increase in its content. In the textural analysis, hardness, chewiness, adhesiveness and gumminess of Jeolpyun with 2% and 4% of Hizikia fusiforme were similar to those of the control, whereas springiness of Jeolpyun with 2%, 4% and 6% of Hizikia fusiforme were similar to that of the control group. Cohesiveness significantly decreased as the amount of Hizikia fusiforme increased. When the Jeolpyun was preserved for one day, all five Jeolpyun showed significant increases in hardness, gumminess and chewiness. However, their adhesiveness significantly decreased. Cohesiveness decreased in all Jeolpyun except for the 8% Jeolpyun. In sensory evaluation, color and aroma became stronger as the content of Hijikia fuziforme increased, and 2% Jeolpyun showed similar hardness with the control. Jeolpyun with Hijikia fuziforme showed no difference in cohesiveness with the control, but the adhesiveness showed a little increase when compared to the control. The overall acceptability of 2% Jeolpyun showed slightly higher than control. After one day of storage, Jeolpyun with 2% of Hijikia fuziforme also showed the highest overall acceptability. And the overall acceptability showed the biggest decrease in the control group. Overall acceptability showed strong negative correlation with color, aroma and hardness, and showed strong positive correlation with cohesiveness and adhesiveness. After one day of storage, overall acceptability showed a decrease in correlation with color and smell and an increase in correlation with cohesiveness, compared to before storage. Results of multiple regression analysis showed that hardness had the biggest influence(－) on the overall acceptability of Jeolpyun, aroma and cohesiveness ranked second(－) and third(+) respectively. After one day of storage, cohesiveness had the biggest influence on the overall acceptability of Jeolpyun. Color and adhesiveness ranked second(－) and third(+) respectively. It can be seen that different factors influence overall acceptability of Jeolpyun after storage.

This study was conducted to evaluate the effects of sweet pumpkin (Cucurbita Maxima D.) powder on the quality characteristics of cookies. The cookies were made with various sweet pumpkin powder levels (10%, 20%, and 30%). The pH of the dough increased while the density of the dough decreased as the amount of sweet pumpkin powder increased. The width of cookies determined by water content in dough increased with increasing sweet pumpkin powder level. The L value of cookies was significantly the largest in the control group. The b value was the highest for the 30% substituted sample group. According to textural measurements, the hardness, cohesiveness, springiness, and brittleness of the cookies with sweet pumpkin powder were higher in concentration than those of the control group. According to the sensory evaluation, the appearance, color, flavor, and texture of cookies with 10-20% sweet pumpkin powder were higher compared to those of the control group. The overall most acceptable cookie group was that with 10% added sweet pumpkin powder.

In this study, the effects of yacon (Smallanthus sonchifolius) leaf on the quality characteristics of cookies were examined. In order to investigate its effects, four different amounts (0%: Control, Y-0.5, Y-1.0, Y-1.5) of yacon leaf powder were added to the cookie dough. Among the physicochemical and sensory characteristics, the density and pH of the dough, spread factor, color value, firmness, consumer acceptability, and Pearson's correlation coefficients were measured. Although there was no significant difference in pH of the doughs among the groups, density significantly decreased with increasing amount of yacon leaf powder (p<0.05). While the L, a, b values, and hardness decreased significantly, DPPH free radical scavenging activity increased significantly as the content of yacon leaf powder increased (p<0.05). Overall acceptability, appearance, taste, and texture between the control and Y-0.5 groups showed no significant differences. This study suggests the possibility of yacon leaf as an ingredient that increases the functionality of cookies.

The rancidity of soybean (Glycine max L.) in powder forms was evaluated by fluorescence spectrum test (FST). The results from the FST were validated by comparing those of 2-thiobarbituric acid (TBA) value and acid value. The storage temperature and time of soybean powders were at the room temperature, 50, and 90oC for 20 days. The maximum excitation and the maximum emission of fluorescent compounds generated from the soybean powder during storage were observed at the wave length of 360 nm and 430 to 440 nm, respectively. The mean particle size of soybean powder was controlled to be 40 μm. The FST results showed that the lipid oxidation during storage at room temperature and 50oC was not progressed actively (p < 0.05), but dramatically progressed at 90oC. All the values at room temperature and 50oC showed a similar pattern during storage. But, at 90oC, the FI (fluorescence intensity) values and the acid values showed similar pattern. The results demonstrated that FST might be useful to measure the rancidity of soybean powder because FST did not require oil extraction to measure the rancidity.

In this study, a high energy ball milling process was employed in order to improve the densification of direct nitrided AlN powder. The densification behavior and the sintered microstructure of the milled AlN powder were investigated. Mixture of AlN powder doped with 5 wt.% as a sintering additive was pulverized and dispersed up to 50 min in a bead mill with very small beads. Ultrafine AlN powder with a particle size of 600 nm and a specific surface area of 9.54 was prepared after milling for 50 min. The milled powders were pressureless-sintered at for 4 h under atmosphere. This powder showed excellent sinterability leading to full densification after sintering at for 4 h. However, the sintered microstructure revealed that the fraction of yitttium aluminate increased with milling time and sintering temperature and the newly-secondary phase of ZrN was observed due to the reaction of AlN with the impurity.