In the present work, spheroidization of angular vanadium powders using a radio frequency (RF) thermal plasma process is investigated. Initially, angular vanadium powders are spheroidized successfully at an average particle size of 100 μm using the RF-plasma process. It is difficult to avoid oxide layer formation on the surface of vanadium powder during the RF-plasma process. Titanium/vanadium/stainless steel functionally graded materials are manufactured with vanadium as the interlayer. Vanadium intermediate layers are deposited using both angular and spheroidized vanadium powders. Then, 17-4PH stainless steel is successfully deposited on the vanadium interlayer made from the angular powder. However, on the surface of the vanadium interlayer made from the spheroidized powder, delamination of 17-4PH occurs during deposition. The main cause of this phenomenon is presumed to be the high thickness of the vanadium interlayer and the relatively high level of surface oxidation of the interlayer.

This objective of this study was to investigate the degradation characteristics of phenol, a refractory substance, by using a submerged dielectric barrier discharge (DBD) plasma reactor. To indirectly determine the concentration of active species produced in the DBD plasma, the dissolved ozone was measured. To investigate the phenol degradation characteristics, the phenol and chemical oxygen demand (COD) concentrations were evaluated based on pH and the discharge power. The dissolved ozone was measured based on the air flow rate and power discharged. The highest dissolved ozone concentration was recorded when the injected air flow rate was 5 L/min. At a discharge power of 40W as compared to 70W, the dissolved ozone was approximately 2.7 – 6.5 times higher. In regards to phenol degradation, the final degradation rate was highest at about 74.06%, when the initial pH was 10. At a discharged power of 40W, the rate of phenol decomposition was observed to be approximately 1.25 times higher compared to when the discharged power was 70W. It was established that the phenol degradation reaction was a primary reaction, and when the discharge power was 40W as opposed to 70W, the reaction rate constant(k) was approximately 1.72 times higher.

This study was carried out to investigate the effect of chlorine water and plasma gas treatment on the quality and microbial control of Latuca indica L. baby Leaf during storage. Latuca indica L. baby leaves were harvested from a plant height of 10cm. They were sterilized with 100μL·L-1 chlorine water and plasma-gas (1, 3, and 6hours), and packaged with 1,300cc·m-2·day-1·atm-1 films and then stored at 8±1?and RH 85±5% for 25days. During storage, the fresh weight loss of all treatments were less than 1.0%, and the carbon dioxide and oxygen concentrations in packages were 6-8% and 16-17%, respectively for all treatments in the final storage day. The concentration of ethylene in the packages fluctuated between 1-3μL·L-1 during the storage and the highest concentration of ethylene was observed at 6 hours plasma treatment in the final storage day. The off-odor of all treatments were almost odorless, the treatments of chlorine water and 1 hour plasma maintained the marketable visual quality until the end of storage. Chlorophyll content and Hue angle value measured at the final storage day were similar to those measured before storage in chlorine water and 1 hour of plasma treatments. E. coli was not detected immediately after sterilization in all sterilization treatments. After 6 hours of plasma treatment, the total bacteria fungus counts were lower than the domestic microbial standard for agricultural product in all sterilization treatments. The total aerobic counts in the end storage day increased compared to before storage, whereas E. coli was not detected in all sterilization treatments. The sterilization effect against bacteria and fungi was the best in chlorine water treatment. Plasma treatment showed sterilization effects, but within a prolonged period of time. In addition, the sterilization effect decreased gradually. These results suggest that chlorine water and plasma treatment were effective in maintaining Latuca indica L. baby Leaf commerciality and controlling microorganisms during postharvest storage.

This study was to confirm the effect of supplementation of superjami bran extract on lipid and antioxidant metabolism. Twenty-five subjects were recruited, and divided into Superjami group (n=12), and Placebo group (n=13) random assignment. Among the groups, the Superjami group took a Superjami bran extract (2 g/2 capsule/day), and the Placebo group took dextrin (2 g/2 capsule/day), for 12 weeks. As a result of the experiment, concentrations of TG, TC, and HDL-C in the blood, were significantly lower than those in the control group, and HDL-C was significantly higher. AI and HTR also showed positive values. Leptin did not differ significantly, but as a result of adipectin, the Superjami group displayed a higher value, compared to the Placebo group, and LAR also had significantly lower value. Antioxidant results showed that GPx, CAT, and RGLU, were significantly higher before as well as after intakes of the Superjami group, and significantly higher levels of the Superjami group, compared to the Placebo group. AOPP showed significantly lower values for the Superjami group, compared to the Placebo group. So, based on this study, ingestion of Superjami bran extract is effective in improving blood lipid concentrations as well as inflammatory substances, and has positive effects relative to increasing antioxidant activity.

The objective of this study was to investigate the quality properties of sausages added with the atmospheric pressure plasma treated extract of Perilla frutescens Britton var. acuta Kudo (red perilla). The lyophilized powder of red perilla extract treated by atmospheric-pressure plasma contained 7.5 g kg-1 nitrite. Sausage samples were manufactured with the addition of sodium nitrite (Control), celery powder (Celery), or plasma-treated extract of red perilla (PTP) to obtain nitrite concentration of 70 mg kg-1. The residual nitrite content was the lowest in PTP during storage for 21 days at 4℃ (p<0.05). The total aerobic bacteria counts were higher in PTP than in Control and Celery during storage at 4℃ (p<0.05). Malondialdehyde content of sausages was significantly lower in PTP than in Control and Celery during storage (p<0.05). PTP showed the lowest L* value and the highest b* value among the tested sausage samples during storage (p<0.05). PTP received the low scores in all the sensory properties of sausages because of its inherent color and flavor. The results suggested that the plasma-treated extract of red perilla was an unsuitable natural nitrite source for cured meat products because of its adverse effect on sensory quality. However, natural nitrite source with increased nitrite content can be produced by the treatment of the natural plant extract with atmosphericpressure plasma.

The passivation of AZ91D Mg alloys through plasma anodization depends on several process parameters, such as power mode and electrolyte composition. In this work, we study the dependence of the thickness, composition, pore formation, surface roughness, and corrosion resistance of formed films on the electrolyte temperature at which anodization is performed. The higher the electrolyte temperature, the lower is the surface roughness, the smaller is the oxide thickness, and the better is the corrosion resistance. More specifically, as the electrolyte temperature increases from 10 to 50 oC, the surface roughness (Ra) decreases from 0.7 to 0.15 μm and the corrosion resistance increases from 3.5 to 9 in terms of rating number in a salt spray test. The temperature increase from 10 to 50 oC also causes an increase in magnesium content in the film from 25 to 63 wt% and a decrease in oxygen from 66 to 21 wt%, indicating dehydration of the film.

In this work, a PAM(Plasma Assisted Machining) technology was applied to milling of high manganese steel, a typical hard-to-machine materials. For this purpose, a transferred type of arc plasma torch was coupled with a 3-axis milling machine, then, used to heat and soften the surface of a high manganese steel plate in front of a 16 mm end mill with 2 blades and hard coatings. From the test results, it was concluded that the cutting load can be significantly reduced down to 57 % by plasma heating with the power level of 3.9 kW, ensuring the improvement of tool life and surface roughness in milling of high manganese work pieces.

바이오존의 대기압 플라즈마를 사용한 쥐치포(Stephanolepis cirrhifer) 중 미생물안전관리 대상인 B. cereus F4810/72 와 S. aureus ATCC 6538의 저감화 정도 및 품질 특성을 관찰하였다. 대기중의 공기를 활용하여 플라즈마 발생을 유도하여 0 분, 1 분, 3 분, 5 분, 10 분 및 20 분 처리하였다. 이후 대상 미생물의 살균력 평가를 위해 표준평판 법을 사용하여 로그 감소값을 계산하고 Color difference meter를 사용하여 Hunter “L”(명도), ”a”(적색도) 및 “b”(황색도)의 차이를 분석했다. 대기압 플라즈마 3분 처리만으로도 이 두 세균을 1 로그 감소(=90% 감소) 시킬 수 있음이 확인되었다. 아울러 최대 20 분 처리시 쥐치포의 명도, 적색도 및 황색도의 차이는 관찰되지 않았다. 그러나, 본 연구에 사용된 대기압 플라즈마의 기타 수산 건어포와 일반 식품에 대한 산업적 적용을 위해서는 추가적인 목적 미생물의 살균력 연구와 각 품질의 특성을 고려한 품질평가 및 관능평가 등의 추가적인 연구의 확대가 필요하다고 사료된다.

배경/목적: 췌장암은 일반적으로 불량한 예후를 보이며, 조기 진단이 어렵다는 점이 이에 영향을 미칠 것으로 생각되고 있다. 본 연구는 한국인 췌장암 환자에 있어서 혈장내 대사체 분석을 시행하여 건강 자원자의 대사체 프로파일과 비교 하였다. 방법: 각 10명으로 비한국인들을 대상으로 이루어진 기존 연구에 비하여 대상자 수가 매우 적지만 검진으로 시행한 복부 CT상 췌장 질환의 증거가 없는 건강한 자원자를 모집하였으며, 이는 췌장암의 조기 진단이 어렵다는 점을 감안할 때 기존 연구에 비한 장점이 될 수 있겠다. 결과: 혈장내 대사체 비교 분석상 췌장암 환자에서 L -lysine의 혈장 농도는 1.36배 높고 L -leucine은 0.63배, palmitic acid는 0.93배 낮은 것으로 나타나 이 세 가지의 대사체 프로파일의 조합이 건강자원자와 췌장암 환자를 가장 잘 구분해 주는 것으로 나타났다. 결론: 앞으로 췌장암의 조기 진단 혹은 발생 역학의 규명을 위하여 대사체 분석에 대한 연구가 더 필요하겠다.

Plasma-sprayed HA coatings on metallic implants are widely used for clinical applications. However, typical lamellar structure along with plasma-sprayed coatings usually leads to weak inter-splat adhesion and impair their mechanical properties. In this research, graphene nanosheet (GNS) reinforced HA coatings were fabricated using plasma spray; these GNSs retained their original structure and distributed homogeneously in the as-sprayed coatings. On the basis of instrumented microindentation tests with and without multiple partial unloading, as compared with the monolithic HA coating, the inter-splat friction force increased by ~ 8.7% for the 1.0 wt% GNS/HA coating, and it slightly decreased to ~ 6.5% for the 2.0 wt% GNS/ HA coating due to GNS agglomeration. Meanwhile, the added GNSs contributed greatly to the indentation yield strength of the HA coatings. These results illustrated that these embedded GNSs at splat boundaries are potential in splat-boundary strengthening and resisting splat sliding.