제련 과정 중 발생하는 폐황산에는 다양한 희소금속들이 포함되어 있으나, 공정수에서 희소금속 회수가 처리기술 부족으로 중화되어 폐기되고 있는 실정이다. 일반적으로 습식제련공정에서의 모액(침출액)은 황산(10~15%) 용액 상태이며, 모액중의 유가금속 (Cu, Zn 등) 및 희소금속(In, Se, Re 등)은 보통 수 ppm에서 수 % 단위로 용해되어 있다. 희소금속은 첨단소재로서의 가치가 높고 수요가 급증하고 있으나 공정수에서 희소금속 처리 기술 부족으로 폐 황산 속 희소금속은 중화되어 폐기되고 있다. 희소금속 처리기술로서 분리막 공정을 희소금속 회수에 적용하면 효율적인 분리/농축을 가능하게 하여 경제적인 이점이 있다. 본 연구에서는 내산성이 뛰어난 방향족 모노머인 메타페닐렌디아민과 파라페닐렌디아민, 지방족 아민모노머인 피페라진와 블렌딩하여 계면중합을 실시하고 물성을 평가한다. 그리고 제조된 분리막의 내산성을 평가하기 위하여 15 wt% 황산용액에 침지한 후 투과성능을 측정하였다.

Recently, the ZIF-67 molecular sieve has emerged as an excellent substitute for the ZIF-8 counterpart due to its potentially high propylene/propane separation performance. Here, for the first time, we investigated the effect of ZIF-67 molecular sieves in mixed matrix membranes (MMMs) for propylene/propane separations by integrating them into 6FDA-DAM polymeric matrix. A thorough investigation on gas transports elucidated that size-based energetic selectivity is a major contributor for the high propylene/propane diffusivity in ZIF-67 containing MMMs. Lastly, the defect-free incorporation of ZIF-67 nanoparticles into 6FDA-DAM polymer matrix effectively retarded physical aging process compared to bare 6FDA-DAM membrane.

Stainless steel is known as a corrosion-resistant material and this superior ability could be a desired property for a pinhole aperture operated in a corrosive environment and thereby be able to maintain both smoothness and a perfect circular shape in order to achieve precise beam alignment. Laser drilling has widely been preferred when placing holes into stainless steel due to its non-contact method of machining. In addition, this method is capable of performing delicate machining while inducing relatively low amounts of heat in the affected zone in comparison with other traditional machining techniques such as punching. Laser drilling is also beneficial for specimens having a thin thickness since manufacturing tolerances are minimal in this case. In this paper, we have attempted to produce holes of various diameters in 10 m thick stainless steel foil by using a femtosecond laser trepanned method. We have demonstrated these to be of perfect circular shape and adhering to low tolerance manufacturing by adjusting the beam parameters. In addition, holes with various diameters have been made by employing previously selected machining parameters and the viability of pinhole apertures fabricated by laser drilling have been evaluated.

In this study, an α-Fe2O3 (hematite) coated porcelain plate was sintered in a temperature range from 1100 oC to 1250 oC using ferrous sulfate. The specimens were investigated by X-ray diffractometer (XRD), scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and UV-visible spectrophotometer. It was confirmed that α-Fe2O3 (hematite) was densely fused to the surface at several tens of μm, the α-Fe2O3 (hematite) was in the form of thin platelet and polyhedra, and no other compounds appeared in the sintering process. In the specimen coated with α-Fe2O3 (hematite), the reflectance spectra show a red absorption band of 560-650 nm. The L* value decreased from 53.18 to 46.94 with the firing temperature. The values of a* and b* were at 19.03 and 15.25 at 1100 oC and gradually decreased with increasing temperature; these values decreased rapidly at 1250 oC to 11.54 and 7.98, respectively. It is considered that the new phases are formed by the phase transition of the porcelain plate (clay), and thus the a* and b* values are greatly influenced.

푸마르산 전해수용액(0.5%, w/w, fumaric acid/slightly acidic electro-analysised water, FS), 활성칼슘 수용액(0.2%, w/w, CaO/distilled water, CaO), 그리고 유전체 방벽 방전 콜드 플라즈마(dielectric barrier discharge atmospheric cold plasma, DACP)를 이용하여 감귤에 접종된 Penicillium digitatum에 대한 저해 효과 및 외관 변화를 연구하였다. 처리 방법은 FS, CaO, CaO와 FS의 병합 처리(FSC), DACP, FS와 DACP, CaO와 DACP, 그리고 FSC와 DACP였다. DACP 처리 전압(34.0, 35.2, 그리고 37.1 kV)과 처리 시간(1, 2, 3, 4, 그리고 5분)을 변수로 하여 처리 조건 최적화를 수행하였다. 병합 처리시 DACP의 조건은 처리 전압 37.1 kV, 그리고 처리 시간 4분이었다. P. digitatum 저해 효과는 곰팡이 발생률(disease incidence, D.I., %)로 확인하였다. 처리 전압 37.1 kV, 처리 시간 4분의 DACP 처리가 사용된 FSC 처리에서 P. digitatum 저해 효과가 가장 높았다(D.I. 51.0%). DACP 처리된 감귤의 D.I.는 DACP 처리 전압이 높아질수록 유의적으로 감소하였다(p<0.05). 처리 전압이 35.2 kV이하인 DACP 처리는 처리 후 귤의 외관에 영향을 주지 않았다. 연구를 통해 천연 세척 소재-콜드 플라즈마 병합 처리가 감귤의 저장성을 높이는 새로운 살균 공정으로 사용될 가능성을 확인할 수 있었다.

In the present study, the structural and fatigue analysis on the shape change of an automatic press are investigated for prediction of operation safety and reliability of the automatic press along the thickness(t) and length(L) of head, and corner shapes(case 1, 2, 3). The equivalent stress and deformation characteristics of the automatic press were studied by computerized analysis method for the bushing production of the seat frame. An external stress of 14.0 MPa was applied to predict the operation stability and the fatigue limit of the structure. As the thickness of the header increased and the length of the header decreased, the load stability applied by the piston improved and the maximum stress and deformation were reduced. In addition, due to the change in shape of the corners, the load applied at the cross-sectional area of the corners decreases, and then the maximum stress and deformation appearing in the header are reduced. That is, the change of corner shapes affects the equivalent stress and deformation. That is the change of corner shapes affects the equivalent stress and deformation. From the fatigue and vibration analysis, fatigue failure does not occur even when the number of alternating operation of the automatic press increases, and the natural frequency is predicted for dynamic characteristics.

본 연구는 영양부추의 미생물학적 안전성을 확보하기 위하여 이산화염소와 차아염소산나트륨을 이용하여 미생물의 저감효과를 분석하고, 최적의 영양부추와 소독제의 비율을 결정하기 위하여 수행하였다. 이를 위하여 영양부추에 E. coli, Salmonella spp., S. aureus, B. cereus을 7.0 log CFU/g 정도로 접종 한 후 이산화염소는 3, 5, 10, 25, 100 ppm 차아염소산나트륨은 100, 150, 200 ppm에서 5, 10, 30, 60분간 처리하였으며, 또한 유기물이 이산화염소와 차아염소산나트륨의 효과에 미치는 영향을 분석하기 위해 영양부추와 소독제를 1 : 2, 1 : 4, 1 : 9, 1 : 19 비율로 처리 하여 소독제의 효과를 분석하였다. 그 결과, 소독제의 농도에 따른 저감효과는 차아염소산나트륨 150 ppm, 이산화 염소 50 ppm으로 30분간 처리시 일반세균수는 2.0 log CFU/ g 정도 감소효과를 나타내었으며, 식중독세균은 차아염소 산나트륨 100 ppm, 이산화염소 3 ppm에서 약 2.0 log CFU/g 정도 감소효과를 보였다. 한편, 이산화염소의 경우 50 ppm 으로 30분간 영양부추를 처리할 경우 탈색 등 상품성이 저하되어 현장 적용이 어렵다고 판단되었다. 또한 영양부 추와 소독제 처리 비율에 따른 미생물 저감효과는 일반세 균의 경우 1 : 4에 비하여 1 : 9에서 유의적으로 높은 저감 효과를 보였다(p < 0.05). 확립된 기술을 영양부추 생산농 장에 적용한 결과 일반세균수의 경우 2.7 log CFU/g, 대장 균군의 경우 4.0 log CFU/g의 감소효과를 보였다. 따라서 영양부추를 세척이후 차아염소산나트륨 150 ppm에서 1 : 9 정도의 비율로 30분간 침지하면 미생물 안전성을 향상시 킬 수 있으며, 최종 소비자에게 보다 안전한 부추의 공급이 가능할 것으로 판단된다.

The physicochemical properties of dry wine produced from domestic kiwifruit according to production year from 2008 to 2012 were studied. pHs of wine were from 4.02(F wine, production year 2009, sterilized) to 4.11(D wine, production year 2012, non-sterilized) and their acidities were lowest in D wine(0.79%) and highest in F wine(1.18%). All the wines have the same soluble solids of 8 °brix and 12% of alcohol, respectively. The reducing sugar was lowest in A wine(production year 2008, non-sterilized) and highest in D wine. The lactic acid was detected as a main organic acid and the free sugar was detected only fructose. As main flavor components, ethyl acetate and 1-pentanol were detected and their sum of 80~90% and a small amount of phenylethyl alcohol which providing rose-like aroma was also detected. The contents of soluble phenolics were highest in D wine(1.07 g/L) and lowest in C wine(0.80 g/L), corresponding to the antioxidant activity was highest found in D wine according to their soluble phenolic contents.

The occurrence of atypical lipomatous tumor of the head and neck is rare, and clinical and histologically differential diagnosis of the tumor is needed for other similar diseases. Herein we report atypical lipomatous tumor arising in neck area. And literature review was done. Complete excision with negative margins followed by long-term follow-up is recommended as the treatment of choice for these uncommon entities.