• Toxicological Research
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• 제5권2호
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• pp.89-96
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• 1989

Rapid and complete epidermal-dermal separation procedure were determined in neonatal rat skin by light microscopic observation and by compairing enzyme activities in the separated epidermis. Microscopic appearance demonstrated the at four different separation procedures used in the study resulted in good separation of epidermis from dermis` heating method (i.e., immersion in 55C water for 30 sec, followed by immersion in 0-4C water) and microwave irradiation for 10 sec were saving time.

• Environmental Engineering Research
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• 제24권4호
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• pp.662-669
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• 2019

Anaerobic digestion is a popular sewage sludge (Ss) treatment method as it provides significant pollution control and energy recovery. However, the low C/N ratio and poor biodegradability of Ss necessitate pretreatment methods that improve solubilization under anaerobic conditions in addition to anaerobic co-digestion with other substrates to improve the process efficiency. In this study, three pretreatment methods, namely microwave irradiation, ultrasonication, and heat treatment, were investigated, and the corresponding improvement in methane production was assessed. Additionally, the simplex centroid design method was utilized to determine the optimum mixture ratio of food waste (Fw), livestock manure (Lm), and Ss for maximum methane yield. Microwave irradiation at 700 W for 6 min yielded the highest biodegradability (62.0%), solubilization efficiency (59.7%), and methane production (329 mL/g VS). The optimum mixture ratio following pretreatment was 61.3% pretreated Ss, 28.6% Fw, and 10.1% Lm. The optimum mixture ratio without pretreatment was 33.6% un-pretreated Ss, 46.0% Fw, and 20.4% Lm. These results indicate that the choice of pretreatment method plays an important role in efficient anaerobic digestion and can be applied in operational plants to enhance methane production. Co-digestion of Ss with Fw and Lm was also beneficial.

• Environmental Engineering Research
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• 제24권2호
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• pp.191-201
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• 2019

Petroleum industry produces one of the popular hazardous waste known as Petroleum Sludge. The treatment and disposal of petroleum sludge has created a major challenge in recent years. This review provides insights into various approaches involved in the treatment, and disposal of petroleum sludge. Various methods used in the treatment and disposal of petroleum sludge such as incineration, stabilization/solidification, oxidation, and bio-degradation are explained fully and other techniques utilized in oil recovery from petroleum sludge such as solvent extraction, centrifugation, surfactant EOR, freeze/thaw, pyrolysis, microwave irradiation, electro-kinetic method, ultrasonic irradiation and froth flotation were discussed. The pros and cons of these methods were critically considered and a recommendation for economically useful alternatives to disposal of this unfriendly material was presented.

• 한국표면공학회지
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• 제56권6호
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• pp.420-426
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• 2023

We prepared a highly sensitive hydrogen (H₂) sensor based on Indium oxides (In₂O₃) porous nanoparticles (NPs) loaded with Platinum (Pt) nanoparticle in the range of 1.6~5.7 at.%. In₂O₃ NPs were fabricated by microwave irradiation method, and decorations of Pt nanoparticles were performed by electroless plating on In₂O₃ NPs. Crystal structures, morphologies, and chemical information on Pt-loaded In₂O₃ NPs were characterized by grazing-incident X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, respectively. The effect of the Pt nanoparticles on the H₂-sensing performance of In₂O₃ NPs was investigated over a low concentration range of 5 ppm of H₂ at 150-300 ℃ working temperatures. The results showed that the H₂ response greatly increased with decreasing sensing temperature. The H₂ response of Pt loaded porous In₂O₃ NPs is higher than that of pristine In₂O₃ NPs. H₂ gas selectivity and high sensitivity was explained by the extension of the electron depletion layer and catalytic effect. Pt loaded porous In₂O₃ NPs sensor can be a robust manner for achieving enhanced gas selectivity and sensitivity for the detection of H₂.

• 공업화학
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• 제27권3호
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• pp.280-284
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• 2016

본 연구에서는 안젤리카로부터 기능성 유효성분을 추출하기 위해 기존의 용매추출법과 마이크로웨이브 추출법을 이용하여 각 변수에 따른 추출량을 확인하였다. 또한 안젤리카로부터 추출된 유효성분의 항산화능 및 플라보노이드성분 함량, 총폴리페놀성분 함량 등을 측정함으로써 유효성분의 기능성을 평가하였다. 기존의 용매추출법의 최적조건인 추출시간(2 h), 주정/초순수의 부피비(60 vol%), 추출온도($60^{\circ}C$)에서 20.6 wt%의 유효성분이 추출되었다. 또한 마이크로웨이브 추출법의 최적조건인 마이크로웨이브 조사시간(6 min), 마이크로웨이브 세기(600 W), 주정/초순수의 부피비(60 vol%)의 조건에서 유효성분이 22.8 wt% 추출되어 기존의 용매추출법에 비해 빠른 시간에 추출이 완료됨을 알 수 있었다. 안젤리카로부터 추출된 유효성분의 추출량 유효성분의 항산화능은 DPPH radical scavening activity로 31.46%이었고, 플라보노이드성분 함량은 14.20 mg QE/mg dw, 그리고 총 폴리페놀 함량은 11.70 mg GAE/g으로 나타났다.

• 대한핵의학회지
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• 제33권4호
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• pp.430-438
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• 1999

목적: 마이크로웨이브를 이용한 방사성 동위원소의 표지와 Sep-Pak 카트리지를 이용한 정도관리 방법의 개선으로 신속한 제조가 가능하면서도 높은 표지효율을 가진 방사성 의약품을 얻고자 하였다. 대상 및 방법: $C_{18}$ 그리고 alumina N Sep-Pak카트리지를 이용한 정도관리 방법을 $^{99m}Tc$-ECD, $^{99m}Tc$-MIBI, $^{99m}Tc-MAG_3$에 적용하였고 표지효율을 측정하였다. 마이크로웨이브를 사용하여 상기의 키트에 방사성 동위원소를 표지하여 표지효율을 비교하였다. 결과: 마이크로웨이브에 의해 생성된 세 가지방사성 의약품은 3 ml용액에 $^{99m}Tc$-ECD와 $^{99m}Tc$-MIBI는 10초, $^{99m}Tc-MAG_3$는 15초의 짧은 마이크로웨이브를 조사하여 모두 95% 이상의 표지효율을 나타내었다. $^{99m}Tc$-ECD와 $^{99m}Tc$-MIBI는 Sep-Pak alumina N 카트리지를 사용하여 짧은 시간 내에서도 정확한 정도관리 결과를 얻을 수 있었다. 방사성 의약품의 제조시간은 정도관리를 포함하여 모두 6분 이하를 나타내었다. 결론: Sep-Pak 카트리지를 이용한 정도관리 방법과 마이크로웨이브에 의한 방사성 의약품의 제조 방법은 일상적인 방사성 의약품의 제조에 적용이 가능하였으며, 방사성 의약품의 제조시간을 크게 단축시킬 수 있었다.

• 한국축산식품학회지
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• 제29권6호
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• pp.709-718
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• 2009

본 연구에서는 돼지고기에 여러 가지 물리적 처리를 실시한 후 PSA의 항원성 변화를 살펴봄으로써 돼지고기의 알레르겐성 감소에 가장 효과적인 처리 조건을 찾아 항원성이 저감화 된 돼지고기 제품 개발에 적용하고자 하였다. 먼저, 돼지고기에 가열, 가압가열, microwave, 초음파 및 감마선을 처리하고 주요 항원인 PSA를 추출하였다. 그후, ci-ELISA, SDS-PAGE 및 immunoblotting을 실시하여 돼지고기의 항원성 변화를 살펴보았다. 80과 $100^{\circ}C$에서 각각 20분간 가열처리 했을 때와 $121^{\circ}C$에서 5, 10 및 30분 가압가열 처리한 경우 PSA와 IgG 항체와의 결합력이 약 10% 이하로 크게 감소하였으며, 특히 가압가열 30분처리 시에 결합력이 5% 이하로 가장 많이 감소하였다. SDS-PAGE와 immunoblotting 결과에서도 무처리구에서 강하게 보였던 PSA band가 80, 100 및 $121^{\circ}C$ 처리에 의해 소실되고 항체와 반응하지 않았다. 또한, microwave 처리시에는 5분과 10분 처리구의 경우 IgG와의 결합력이 각각 12% 및 10% 정도로 많이 감소하였지만 microwave 1분 처리와 낮은 온도에서 1, 5, 10 및 20분간 처리한 경우에는 약 80% 이상의 높은 결합력을 유지하였다. 초음파(5, 10, 30 및 60분) 및 감마선 처리(1, 3, 10 및 20 kGy)에 의한 돼지고기의 항원성 변화를 알아본 결과에서는 초음파 처리구 전체에서 여전히 높은 결합력을 유지하였으며 SDS-PAGE에서도 초음파 처리구의 PSA band는 무처리구와 비교 시 크게 약화되지 않았다. 감마선 처리구는 모든 선량에서 IgG와의 결합력이 무처리구 보다 약 10-15% 정도 증가하였음을 알 수 있었다. 이상의 결과를 종합해 볼 때 낮은 온도에서 microwave 및 초음파 처리한 경우와 감마선 처리한 경우는 돼지고기의 항원성을 감소시키는데 큰 영향을 주지 못하였지만, $80^{\circ}C$ 이상의 가열처리는 항원성을 크게 감소시켰다. 특히, PSA는 가압가열처리 시 가장 크게 변화하였으므로 본 연구에 사용된 가압가열 처리조건을 저 알레르기 돼지고기 식품 개발에 응용할 경우 긍정적인 결과를 얻을 것으로 사료된다.

• 한국재료학회지
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• 제17권12호
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• pp.669-675
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• 2007

Hydroxyapatite (HAp) and biphasic calcium phosphate (BCP) nano powders were synthesized using the microwave-assisted synthesis process dependent on pH and microwave irradiation time. The average size of a powder was less than 100 nm in diameter. Through in-vitro cytotoxicity tests by an extract dilution method, the HAp and BCP nano powders have shown to be cytocompatible for L-929 fibroblast cells, osteoblastlike MG-63 cells and osteoclast-like Raw 264.7 cells. The activation of osteoblast was estimated by alkaline phosphatase (ALP) activity. When the HAp and BCP were treated to MG-63 cells, alkaline phosphatase activities increased on day 3, compared with those of the untreated cells. Also, the collagen fibers increased when the HAp and BCP powders suspension were treated to MG-63 cells, compared to those of the untreated cells. Quantitative alizarin red S mineralization assays showed a trend toward increasing mineralization in osteoblast cultured with powder suspension. In conclusion, hydroxyapatite and biphasic calcium phosphate appeared to be a bone graft substitute material with optimal biocompatibility and could be further applied to clinical use as an artificial bone graft substitute.

• 한국결정성장학회지
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• 제20권5호
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• pp.197-201
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• 2010

$ZnWO_4$ nanocrystallines were prepared from polymeric complex method using microwave irradiation. The average nanocrystalline sizes were 18~25 nm showing an ordinary tendency to increase with the temperatures from 400 to $600^{\circ}C$. Bulk type single crystals of $ZnWO_4$ were grown successfully in the [100], [010] and [001] directions using the Czochralski method. The effect of the growth parameters, such as the rotation speed, pulling rate and diameter of the grown crystals, were examined. The hardness, thermal expansion coefficients and dielectric constants of the crystals were evaluated.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2512-2518
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• 2014

The praseodymium-doped $TiO_2$ photocatalyst samples, which could degrade methyl orange under UV irradiation, were prepared by sol-microwave method for improving the photocatalytic activity of $TiO_2$. The resulting materials were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectra, Fourier transform infrared spectra (FTIR) and Ultraviolet-visible diffuse reflectance spectra (UV-vis DRS). It was found Pr doping retarded the growth of crystalline size and the phase transformation from anatase to rutile, and narrowed the band gap energy. Praseodymium doping brought about remarkable improvement in the photoactivity. The optimal dopant amount of Pr was 2% by molar of cement and the calcination temperature was $500^{\circ}C$ for the best photocatalytic activity. The improvement of photocatalytic activity was ascribed to the occurrence of lattice distortion and the effective containment of the recombination of the electron-hole by $Pr^{3+}$.