천연식물유황(MSM; Methyl Sulfonyl Methane) 급여가 오리 사육성적에 미치는 영향

황윤화,정호진,이영,황보식 한국가금학회 2010 한국가금학회 정기총회 및 학술발표회 Vol.27 No.-

The objective of this study was to determine the effect of MSM (methyl sulfonyl methane) supplementation on growth performance in ducks. Three experiments were carried out to investigate the effect of level and feeding period of dietary MSM and Monacus culture on the performance.0.0(C), 0.025(T1), 0.05(T2), and 0.03%(in 0.025% Bacillus subtillus at 1×10?cfu/g and 2.5% Monacus culture, T3) of MSM was added to commercial duck diets, respectively, and fed during 42 days of age. As a result, Treatment Ⅲ of growth performance (mortality, feed conversion rate , market weight, uniformity, etc.) were identified as the most outstanding.

오리육의 항산화 효과

정호진,황윤화,이영,황보식 한국가금학회 2010 한국가금학회 정기총회 및 학술발표회 Vol.27 No.-

This study performed to evaluated extraction(TRT1; breast of duck meat extracted with water, TRT2; breast of duck meat extracted with 50% ethanol, TRT3; thigh of duck meat extracted with water, TRT4; thigh of duck meat extracted with 50% ethanol) and addition level(0.05, 0.1, 0.25, 0.5, 1.0, 2.0%) of duck meat on antioxidant activity. As a result, iron chelation activity of duck meat extracted with 50% ethanol were showed higher levels than duck meat extracted with water. Especially TRT2 showed nearly 90% at 2% level. Reducing power of both extracts showed low rate at all level. DPPH radical scavenging activity of breast extracts were showed higher over 0.5% levels than thigh extracts.

Relaxation and Phase-transition Characteristics of Relaxor Ferroelectric Potassium Lithium Niobate

전병옥,정중현,최병춘,황윤화 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.11

The electric modulus relaxations were considered to be coupled phenomena between the polarization fluctuations < P2 > due to local symmetry breaking and ionic hopping through nearest neighbor sites. The Nb-rich potassium lithium niobate (K5.595Li3.125Nb11.28O30) crystals exhibited a ferroelectric diffused phase transition around the dielectric maximum temperature Tmax = 350 C. The electric modulus relaxations were characterized by using the Cole-Davidson distribution of the electric modulus relaxation times at frequencies ranging from 100 Hz to 1 MHz. Although the lattice constants along the a-axes and the c-axes and the tetragonal unit cell volume showed linear expansions with increasing temperature T, the axial ratio c/a decreased with increasing T at temperatures below the Burn’s temperature TB = 550 C. The dielectric relaxation accompanied the high ionic conduction in the temperature range above Tmax = 350 C. The ac conductivity 0(!) was analyzed by using the formulae 0(!)/dc = 1 + (!/!O)n, where !O is the crossover frequency. It was considered that a double-Arrhenius behavior of the dc conductivity dc at temperatures around the Burn’s temperature TB = 550 C was suspected of thermally activated motions in the random distribution of oxygen vacancies and lithium ions. The ac universality could result in a disordered configuration of the mobile ions, i.e., the dc conductivity at temperatures above TB. The slow relaxations of the nano-sized polar regions may contribute to the dc conductivity dc at temperatures below TB. The characteristic relaxation time CD showed a change in activation energy from 1.08 eV to 0.80 eV at temperatures around TB. The scaling factor " ·T/"0 1 increased in proportion to (TB − T) at T < TB, but was almost constant at T > TB, where "0 1 is the high frequency dielectric constant and T is the temperature in Kelvin.

Impact of synthesis routes on the chemical, optical, and electrical properties of graphene oxides and its derivatives

김영재,강영호,김나라,이종훈,황윤화,이선민,최성묵,김원배,이광희 한국물리학회 2015 Current Applied Physics Vol.15 No.11

Solution-processed graphene oxides in their reduced forms are prominent prospective functional materials for organic optoelectronics. For graphene oxide synthesis, several methods have been developed, which induce varying properties in their products. However, the dependence of the graphene oxide properties on their synthesis methods has rarely been studied, hindering the selection of the optimum synthesis route for a target application. In this study, we report our study results on the properties of synthesized graphene oxides and their reduced forms created using several synthesis methods, such as the modified Hummers' method, the improved method, and the Staudenmaier's method as well as from two commercial sources, Angstron Material, Inc. and Graphos, Inc. Focusing on the transparent electrode application, the properties of thin films were investigated using UVevisible spectroscopy, Hall measurements, atomic force microscopy, Raman spectroscopy, work function measurements, and X-ray photoelectron spectroscopy. Our results reveal significant morphological, elemental, structural, and optoelectrical property variations among the as-prepared and reduced thin films of graphene oxides by their synthesis methods. In addition, the results show that the graphene oxides synthesized using the modified Hummers' method and the product from Angstron Material, Inc. are the most suitable materials for the transparent electrode application.

소규모 해수담수화시설 물 생산량 제고 방안 - 전라남도 해수담수화시설을 중심으로 -

정용문,오은하,박현수,김민영,송승리,김학림,차윤경,한용원,황윤화,김익산,박귀님 한국도서(섬)학회 2024 韓國島嶼硏究 Vol.36 No.1

해수담수화는 무한한 수자원인 해수를 이용해 담수를 생산하는 수처리 방법이다. 국내에서는 역삼투법을 이용한 해수담수화시설이 설치되어 연간 3백만 ㎥의 담수가 생산되고 있다. 하지만 해수담수화시설의 용량 부족, 원수인 염지하수의 부존량 감소 등으로 인해 섬 지역 물 부족 문제가 완벽하게 해결되지 못하고 있다. 또한, 해수담수화시설의 낮은 회수율, 현지 운영자의 전문성 부족, 시설 수리 및 보수의 어려움, 관로 노후화로 인한 누수 및 오염 등 여러 부분에서 개선이 필요하다. 본 연구에서는 성능모사 프로그램을 이용해 소규모 해수담수화시설의 담수생산량은 높이고 전기소모량은 줄일 수 있는 공정을 비교 분석하였다. 소규모 해수담수화시설 성능모사를 위해 주요 영향인자를 조사한 결과 전라남도 지역 해수담수화시설은 대부분 ‘1st RO’공정이고, 시설 중 80 % 이상이 하루 담수생산량 50 ㎥이상 이며, 원수의 총용존고형물량은 최소 115 mg/L, 최대 28,273 mg/L, 평균 5,676 mg/L이었고 원수의 수온은 최소 5.2 ℃, 최대 28.1 ℃, 평균 17.0 ℃로 나타났다. 조사결과를 토대로 섬 지역에 보편적 설치되어 있는 해수담수화 공정 조건인 용량 50 ㎥/일, 최종 담수의 총용존고형물, 500 mg/L 이하, 원수의 총용존고형물량 6,500 mg/L, 수온 17 ℃를 성능모사를 위한 설계조건으로 정했다. 공정으로는 기존‘1st RO’공정, 에너지회수장치를 추가한 ‘1st RO + ERD’공정, 농축수를 원수로 재순환시키는‘1st RO + 재순환’공정과 ‘2nd RO + 재순환’공정을 설계해 담수의 수질 및 수량 변화를 비교분석 하였다. 기존‘1st RO’공정에서는 담수 50 ㎥/일을 생산하기 위해서는 원수 200 ㎥/일이 필요했으나 ‘1st RO + 재순환’공정과 ‘2nd RO + 재순환’공정에서는 소요되는 원수량을 83.3 ㎥/일, 66.7 ㎥/일로 낮출 수 있다. 공정별 전력소모량을 살펴보면 기존‘1st RO’공정은 1.47 kWh/㎥이였으나 ‘1st RO + ERD’공정에서는 0.45 kWh/㎥까지 낮아지므로 전기가 부족한 섬 지역에 필요한 공정이다. ‘1st RO + 재순환’공정은 농축수 재순환 배관만 설치하면 회수율을 60 %까지 높일 수 있기 때문에 기존 시설을 이용해 최소예산으로 담수 생산량을 높일 수 있다. ‘2nd RO + 재순환’공정은 기존 시설에 새로운 역삼투 모듈을 설치해야하기 때문에 비용이 많이 발생하지만, 회수율을 75 %까지 높일 수 있어 염지하수 자원이 부족한 섬 지역에 적합한 공정이다. 마지막으로 원수의 수온이 낮은 겨울철보다 수온이 높은 여름철에 전기에너지 소모량을 낮출 수 있다. 해수담수화시설은 섬 지역 물 부족 문제를 해결할 수 있는 가장 현실적이고 주민들의 물 사용에 대한 체감도가 높은 효율적인 방법이다. 기존에 노후화된 해수담수화시설을 교체하거나 신규로 설치할 때 기존‘1st RO’공정이 아닌 전기소모량을 낮출 수 있는 ‘1st RO + ERD’공정, 물 생산량을 높일 수 있는 ‘1st RO + 재순환’공정과 ‘2nd RO + 재순환’공정이 섬 지역 여건에 맞게 설치될 수 있도록 고려되어야 한다. Desalination was a water treatment process that involved converting saline water to fresh water. Desalination generated an estimated 0.03 hundred million ㎥/day of fresh water in Korea. But, water shortage problems in the island area were not solved regarding the low capacity of desalination plants, the low amount of available salinity groundwater, etc. Furthermore, the low recovery rate of freshwater, lack of expertise of local operators, water leakage and contamination by old pipelines needed to be improved. This study used a reverse osmosis system projection program to compare compared desalination processes to improve water production and decrease electricity consumption. It was investigated that over 80 % of small-scale desalination plants in Jeollanam-do produced 50 ㎥/day. The total dissolved solids of feed water were at least 115 mg/L, up to 28,273 mg/L, an average of 5,676 mg/L, and the water temperature of raw water was at least 5.2 ℃, up to 28.1 ℃, and the average of 17.0 ℃. Based on the investigation results, plant capacity and the total dissolved solids of the final freshwater for performance simulation were set at 50 ㎥/day, 500 mg/L, and the total dissolved solids and temperature of raw water were set at 6,500 mg/L, and 17 ℃. The process compared and analyzed changes in the quality and quantity of freshwater by designing the ‘1st RO’ process, the ‘1st RO + ERD’ process with an energy recovery device added, the ‘1st RO + Recirculation’ process, and the ‘2nd RO + Recirculation’ process. In the ‘1st RO’ process, 200 ㎥/day of feed water was required to produce 50 ㎥/day of fresh water, but in the ‘1st RO + Recirculation’ process and the ‘2nd RO + Recirculation’ process, the amount of feed water required could be reduced to 83.3 ㎥/day and 66.7 ㎥/day. The ‘1st RO’ process consumed 1.47 kWh/㎥. However, in the ‘1st RO + ERD’ process, it is lowered to 0.45 kWh/㎥. The recovery rate was increased by 75 % in the ‘2nd RO + Recirculation’ process. Finally, reducing the electric energy consumed in freshwater production in summer was possible. When replacing old desalination plants or installing new ones, the ‘1st RO + ERD’ process, which can lower electricity consumption, should be considered rather than the ‘1st RO’ process, the ‘1st RO + Recirculation’ process and the ‘2nd RO + Recirculation’ process, which could increase waster production.