• Journal of Applied Biological Chemistry
• /
• 제54권2호
• /
• pp.84-88
• /
• 2011

Edestin, a major hempseed storage protein from Cheungsam, was isolated to apparent homogeneity by acid precipitation and gel filtration chromatography. The native molecular weight of purified edestin was approximately 300 kDa by Sephacryl S-300 gel filtration. Upon adding 2-mercaptoethanol, the isolated edestin of 56.7 kDa on the non-reduced sodium dodecyl sulfate polyacrylamide gel was converted into subunits, suggesting that the protein might be composed of subunits linked by disulfide bond. Cheungsam edestin was rich in essential amino acids and it has 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. The results suggest that Cheungsam edestin might be utilized as a superior antioxidative nutrient.

• 한국고분자학회:학술대회논문집
• /
• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
• /
• pp.375-375
• /
• 2006

The preparation methods are to be used as "melting method" and "absorption method", respectively. The reaction mixture in the reaction container was heating up the reaction mixture to $200^{\circ}C$ for 2 hour. The mixing time of lab scale preparation should be provided quit long, instead of the short working time in a compounder vessel. And The PP-PCM mixture in the reaction container was heating up the mixture around $60-80^{\circ}C$ for 2 hour. A melting method of frozen gel with 50/50 weight ratio of polypropylene-normal octadecane was prepared by adding PP chip and normal octadecane. An absorption method of frozen gel with 70/30 weight ratio of PP 4.8-normal n-octadecane was prepared by adding PP powder and normal octadecnae.

• Food Science and Biotechnology
• /
• 제15권6호
• /
• pp.856-859
• /
• 2006

The effects of moisture content on non-fracture dynamic properties and fracture gel quality of Pacific whiting surimi were investigated to determine their relationships. Surimi samples were tested at various moisture contents (75, 78, and 81 %). Torsion test showed that shear stress decreased rapidly and strain values decreased gradually as moisture concentration increased. Dynamic storage modulus (G') also decreased as moisture content increased. A strong positive correlation ($R^2=0.90$ to 0.99) was found between the G' measured at temperatures between 10 and $45^{\circ}C$ and fracture stress values. The results indicate that dynamic rheological measurements could be used as a tool for early gel quality assessment.

• 한국분말재료학회지
• /
• 제17권5호
• /
• pp.409-414
• /
• 2010

Titanium dioxide ($TiO_2$), which is one of the most basic materials in our daily life, plays a key role for environment purification. We synthesized $TiO_2$ nanoparticles by the hydrolysis reactions of titanium tetraisopropoxide using $HNO_3$ as a peptizing agent or $CH_3COOH$ as a chelating agent in the sol-gel method. The powder consisted of a rod shape or a spherical shape according to the concentration and kind of acid. The physical properties of $TiO_2$ nanoparticles were investigated with X-ray diffraction, SEM, BET analysis, and UV-Vis spectrophotometer.

• Food Science and Biotechnology
• /
• 제16권6호
• /
• pp.1069-1071
• /
• 2007

The frequency independent critical concentration (Cc) of xanthan and carob (X/C) mixed gel was determined based on the Winter-Chambon's theory. X/C mixed (X/C=1:1 ratio) gels were prepared from 0.1 to 1% of concentration. The linear viscoelastic properties, i.e., storage and loss modulus, of X/C mixed gel at $20^{\circ}C$ were measured by frequency sweep tests. The frequency independence of tangent function of phase angle (tan ${\delta}$) of X/C mixed gels was graphically determined from the intersection of the plot of phase angle against concentration at varied frequencies. The intersection (C=0.43%) was considered to be Cc of X/C mixed gel.

• KSBB Journal
• /
• 제17권4호
• /
• pp.365-369
• /
• 2002

수용성 형태로 존재하는 융합 페리틴을 정제함에 있어서 실리카 분말을 이용한 전처리 공정은 전체 정제 공정효율 증가에 기여하였다. 전처리 공정을 통해 정제된 융합 페리틴의 순도를 높이기 위해 젤 여과 크로마토그래피를 통해 보다 정제된 응합 페리틴을 얻을 수 있었다. 이렇게 정제된 융합 페리틴의 철분결합능력을 분석해본결과 320 moles $F_{H}+F_{L}$ mole로 활성이 우수함을 알 수 있었으며, 분자량 분석을 통해 융합페리틴(40 k dalton)은 trimer와 monomer형태로 존재함을 확인할 수 있었다

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1997년도 추계학술대회 논문집
• /
• pp.48-51
• /
• 1997

(Pb. La)TiO$_3$ thin films were fabricated by sol-gel Processing and spin-coated on the Pt substrate. The spin-coated PLT films were sintered at 75$0^{\circ}C$ for 5min by rapid thermal ann La content dependence of the electrical properties of the PLT thin films are discussed. Wit La mole% from 20 to 36mo1e%. the dielectric constant of the PLT thin films decreased f 570. P-E hysteresis loops changed from ferroelectric to paraelectric. and the charge storage charging time decreased. The Curie Point decreased with increasing La content. The leak density also decreased and La 36mo1% species shows mood characteristics less than 10- electric field 500 (KV/cm) Because of the broad range of composition-controlled ferroelectric PLT thin films are suitable for memory application.

• 한국식품저장유통학회지
• /
• 제18권5호
• /
• pp.651-660
• /
• 2011

자두 '대석조생'의 생육단계별 수확시기 및 저온저장 온도에 따른 저온장해과 발생 양상과 품질 특성을 구명하고자 하고자, 자두 '대석조생'을 60%, 80% 그리고 90% 이상의 착색율로 구분하여 수확한 후, 1, 4, 5, $6^{\circ}C$ 그리고 $20^{\circ}C$에 최대 48일간 그리고 $20^{\circ}C$에서 3일간 숙성시키면서 호흡 변화, 품질 특성 및 저온 장해과 발생 양상을 조사하였다. 60% 착색기에 수확한 자두를 보다 낮은 저온에 저장하였을때 경도, 색도, 중량감소율과 적정산도의 유지에 효과적이었으며, 이 조건에서 에틸렌 발생량과 호흡량도 보다 낮게 유지되었다. '대석조생' 자두의 저온장해 증상은 주로 내부 갈변을 동반한 gel breakdown과 과육투명화 현상이었는데, 이러한 저온장해과는 모든 숙기별 처리구 그리고 $6^{\circ}C$ 이하의 모든 저장 온도에서 발생하였다. 그러나 성숙이 진행되지 않은 과일일수록, 그리고 저장 온도가 낮을수록 저온장해과 발생율을 낮게 나타났다. 이 결과는 '대석조생' 자두의 저온장해과 발생이 저장기간 동안의 호흡 양상과 관련되어 있음을 의미한다.

• 생약학회지
• /
• 제50권4호
• /
• pp.312-317
• /
• 2019

In order to obtain basic data on the shelf life of Epimedii Herba (EH), a physicochemical characteristics including weight loss rate, loss on drying, ash, acid-insoluble ash, and quantitative determination were evaluated to compare the data by packaging methods including general (G), general + silica gel (GS), alumium (AL), and alumium + silica gel (ALS) packaging and storage periods (0-66 months). All physicochemical analyzes were conducted using the method of "The Korean Pharmacopoeia (KP) 9^th edition". As a result, weight loss rate (%), loss on drying (%), ash (%), acid-insoluble ash (%) of EH according to the packaging methods and storage periods were -0.27-4.73%, 3.06-9.35%, 5.48-7.37%, and 0.45-0.99, respectively. In the quantitative analysis of icariin, the marker compound of EH using high-performance liquid chromatography, the initial content was 0.44% at 0 month in all packaging methods. After that, the result of analyzing the content of icariin every 6 months was detected 0.44-1.18%. All of the above results satisfied the acceptance criteria for loss on drying, ash, acid-insoluble ash, and quantification contained in the KP. This study can be used as a basic data for establishing the packaging method and shelf life of EH.

• 태양에너지
• /
• 제15권3호
• /
• pp.15-27
• /
• 1995

본 연구는 상변화물질로써 무기염수화물계 물질인 피로인산나트륨($Na_4P_2O_7{\cdot}10H_2O$)이 채워져 있는 직육면체형 잠열축열조 내에서 축열과정시 일어나는 상변화물질의 온도특성, 열전달현상, 축열량 등을 실험적으로 측정하고 그 결과들을 수치해석결과들과 비교 검토한 것이다. 축열과정시 상변화물질인 피로인산나트륨은 용융상태가 액체상태가 아닌 gel상태이므로 액체상태에서의 주된 열전달현상으로 나타나는 자연대류 유동현상이 일어나지 않아 전도에 의한 열전달현상이 지배적인 것으로 나타났다. 무기염수화물계 상변화물질은 공극율(공기 함유율)이 작을수록 열용량이 커지므로 축열과정시 공극율이 큰 경우보다 온도가 서서히 상승되었으며, 실험으로 측정된 온도값과 수치해석적인 방법으로 계산된 온도값은 최대 15%의 차이가 났다.