• Title/Summary/Keyword: gel property

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The Preparation and Electrical Characteristics of BST Thin Film by Spin-Coating Method (회전코팅법을 이용한 BST 박막의 제조 및 전기적 특성에 관한 연구)

  • Ki, Hyun-Chul;Kim, Duck-Keun;Lee, Seung-Woo;Hong, Kyung-Jin;Lee, Jin;Kim, Tae-Sung
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.918-920
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    • 1999
  • Recently, the ceramics of high permittivity are applied to DRAM and FRAM. In this study, (Ba, Sr)$TiO_3$ (BST) ceramics thin films were prepared by Sol-Gel method. BST solution was made and spin-coated on Pt/$SiO_2$/Si substrate at 4000[rpm] for 10 seconds. Coating process was repeated 3 times and then sintered at $750[^{\circ}C]$ for 30 minutes. Each specimen was analyzed structure and electrical characteristics. Thickness of BST ceramics thin films are about $2000[\AA]$. Dielectric constant and loss of thin films was little decreased at $1[kHz]{\sim}1[MHz]$. Dielectric constant and loss to frequency were 250 and 0.02 in BST3. In accordance with applied voltage, property of leakage current was stability when the was $0{\sim}3$[V]. According to voltage, leakage current was increased exponentially at $4{\sim}7$[V].

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Quality Characteristics of Pork Patties Prepared with Mugwort, Pine Needle and Fatsia Leaf Extracts (쑥, 솔잎 및 두릅 추출물을 첨가한 돈육 Patty의 품질 특성)

  • 정인철;남주현;송형익;박충균;문윤희
    • Journal of Life Science
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    • v.10 no.4
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    • pp.326-332
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    • 2000
  • In order to investigate the possibility of functional property improvement of meat products, four kinds of pork patties were prepared with water 10% as control, mugwort extract 10%, pine needle extract 10% and fatsia leaf extract 10%, respectively. In case of control moisture content was higher, but crude fat was lower, compared to patties treated with plant extracts. Crude ash content of pine needle extract treatment showed higher level than that of other patties. pH range of patties revealed to 5.92∼5.978. In raw patties Hunter's L-and a-value of control were higher than those of plant extract treatment, and a-value of raw patties showed higher level than that of cooked. Yield, water holding capacity, salt soluble protein extractability and gel strength among patties did not show significant differences. In control patty, fat retention was lower compared to other plant extract treatments, but water soluble protein extractability was higher compared to pine needle. Values such as hardness, springiness, cohesiveness, gumminess and chewiness were not significantly different among the patties. In sensory scores such as aroma, juiciness and palatability, significant differences were not observed among cooked patties, but texture score was higher in the order pine needle, mugwort, fatsia leaf and control.

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Functionality and Application of Dietary Fiber in Meat Products

  • Kim, Hyun Jung;Paik, Hyun-Dong
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.695-705
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    • 2012
  • Dietary fiber naturally present in various sources of cereals, legumes, fruits and vegetables plays a physiological role in human health, such as lowering cholesterol and blood pressure, improving blood glucose control in diabetes, helping with weight loss and management, and reducing cancer risk. In addition, dietary fibers have has been added as a functional food ingredient to food products to provide water-holding capacity, viscosity, gel-forming ability, and fat-binding capacity to food products. These beneficial characteristics of dietary fiber components can improve the image of meat products to be healthy and functional food products. This article reviews the concept and current definition of dietary fibers in food products along with their health benefits and functional characteristics. Dietary fibers from different sources like cereals, legumes, fruits, and vegetables and soluble dietary fibers have been applied as functional ingredients to various types of meat products, such as beef patties, ground beef and pork, pork and chicken sausages, meatballs, and jerky etc. Based on the application of dietary fibers to different types of meat products, possible future characteristics in selecting appropriate dietary fiber ingredients and their proper incorporation are explored to develop and produce healthy and functional meat products with high dietary fiber contents.

Surface Modification of Cellulose Nanofibrils by Carboxymethylation and TEMPO-Mediated Oxidation (카르복시메틸화 및 TEMPO 촉매 산화 처리에 의한 셀룰로오스 나노피브릴의 표면 개질)

  • Sim, Kyujeong;Youn, Hye Jung;Jo, Yeonhee
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.42-52
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    • 2015
  • In this study, cellulose nanofibrils (CNF) were modified through carboxymethylation or TEMPO-mediated oxidation and their effects on ionicity and characteristics of sheet, film, and foam were investigated. Carboxymethylation was carried out on pulp fibers as a pre-treatment before preparation of CNF. The gel-like and translucent CNF hydrogel was obtained by grinding of carboxymethylated cellulose fibers. Carboxymethylated CNF film and freeze dried sheet showed higher transparency than that of untreated CNF. The CNF sheet with high strength and the CNF foam without large ice crystals were obtained by using the carboxymethylated CNF. TEMPO-mediated oxidation was carried out as a post-treatment of CNF. The zeta potential and charge demand of TEMPO-oxidized CNF were increased with an increase in oxidation time and addition amount of NaClO. The density of sheet made of TEMPO oxidized CNF was increased with the amount of oxidizing agent. The TEMPO oxidized cellulose nanofiber (TOCN) which was obtained from supernatant after centrifugation could be converted to transparent film.

Physicochemical Properties of Enzymatically Modified Maize Starch Using 4-${\alpha}$-Glucanotransferase

  • Park, Jin-Hee;Park, Kwan-Hwa;Jane, Jay-Iin
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.902-909
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    • 2007
  • Granular maize starch was treated with Thermus scotoductus 4-${\alpha}$-glucanotransferase (${\alpha}$-GTase), and its physicochemical properties were determined. The gelatinization and pasting temperatures of ${\alpha}$-GTase-modified starch were decreased by higher enzyme concentrations. ${\alpha}$-GTase treatment lowered the peak, setback, and [mal viscosity of the starch. At a higher level of enzyme treatment, the melting peak of the amylose-lipid complex was undetectable on the DSC thermogram. Also, ${\alpha}$-GTase-modified starch showed a slower retrogradation rate. The enzyme treatment changed the dynamic rheological properties of the starch, leading to decreases in its elastic (G') and viscous (G") moduli. ${\alpha}$-GTase-modified starch showed more liquid-like characteristics, whereas normal maize starch was more elastic and solid-like. Gel permeation chromatography of modified starch showed that amylose was degraded, and a low molecular-weight fraction with $M_w$ of $1.1{\times}10^5$ was produced. Branch chain-length (BCL) distribution of modified starch showed increases in BCL (DP>20), which could result from the glucans degraded from amylose molecules transferred to the branch chains of amylopectin by inter-/intra-molecular transglycosylation of ${\alpha}$-GTase. These new physicochemical functionalities of the modified starch produced by ${\alpha}$-GTase treatment are applicable to starch-based products in various industries.

Anticoagulant Properties of the Active Compound Derived from Cinnamomum cassia Bark

  • Lee, Hoi-Seon
    • Food Science and Biotechnology
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    • v.16 no.2
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    • pp.218-222
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    • 2007
  • The anticoagulant properties of Cinnamomum cassia bark-derived materials were evaluated against platelet aggregation induced by arachidonic acid (AA), collagen, platelet activating factor (PAF), or thrombin, and these effects were then compared to those of three commercially available compounds (cinnamic acid, cinnamyl alcohol, and aspirin). The active constituent obtained from C. cassia barks was isolated by silica gel column chromatography and high pressure liquid chromatography (HPLC), and was characterized as trans-cinnamaldehyde by MS, $^1H-NMR$, $^{13}C-NMR$, and IR spectroscopy. With regard to 50% inhibitory concentration ($IC_{50}$) values, cinnamaldehyde was found to effectively inhibit platelet aggregation induced by AA ($IC_{50},\;43.2\;{\mu}M$) and collagen ($IC_{50},\;3.1\;{\mu}M$). By way of comparison, cinnamaldehyde proved to be a significantly more potent platelet inhibitor against platelet aggregation induced by collagen than aspirin. The effect exerted by cinnamaldehyde against platelet aggregation induced by AA was 1.2 times less than that of aspirin. These results indicate that cinnamaldehyde may prove useful as a lead compound for the inhibition of platelet aggregation induced by AA and collagen.

Improvement of Physical Property of Autoclaved Light-Weight Concrete Using Admixtures and Chemical Reactants (혼화재 및 화학반응제를 혼입한 경량기포콘크리트의 물성 개선)

  • Song, Hun
    • Journal of The Korean Digital Architecture Interior Association
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    • v.12 no.4
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    • pp.87-95
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    • 2012
  • Autoclaved lightweight concrete (ALC), also known as autoclaved aerated concrete (AAC), is a lightweight, precast building material that simultaneously provides structure, insulation. ALC is a unique building material. Because of its cellular nature, it is lightweight, self-insulating, as well as sound and fireproof. ALC products include blocks, wall panels, floor and roof panels, and lintels. Recently, the use of ALC has became increasingly popular. However, ALC have high water absorption, low compressive strength and popout the origin of the low surface strength in its properties. Thus, this study is to improve the fundamental strength by controls of increasing of admixtures and chemical reactants. Admixtures make use of meta kaolin and silica fume, chemical reactants make use of sodium silicate and sodium hydroxide. From the test result, the ALC using admixtures and chemical reactants have a good fundamental properties compared with plain ALC. These good fundamental properties is caused by the admixtures and chemical reactants of ALC by the reason of the micro filling effect and chemical binding of C-S-H gel, tobermolite and quartz.

Technical Review of Slurry and Gelled Propellant (슬러리와 젤 추진제의 기술개발 동향)

  • Jeong, Byung-Hun;Ko, Seung-Won;Hwang, Kab-Sung;Han, Jeong-Sik;Hong, Myung-Pyo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.04a
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    • pp.168-171
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    • 2007
  • A technical review of current slurry and gelled propellants is presented. In advanced countries, it is confirmed that these propellants have high specific impulse, density, excellent handling, safety characteristics and thrust controllability through research since 1950s. Substantial researches have been pursued to characterize the rheological properties, spray/combustion phenomena and propulsion system design for the gel propellant characteristics. Slurry and gelled propellants are developing actively to applicate both military and space propulsion fields such as tactical missile, air-breathing ramjet, pulse detonation engine, and combined cycle engine of future propulsion mode.

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Investigation of acrylic/boric acid composite gel for neutron attenuation

  • Ramadan, Wageeh;Sakr, Khaled;Sayed, Magda;Maziad, Nabila;El-Faramawy, Nabil
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2607-2612
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    • 2020
  • The present work was aimed to show the possibility of using hydrogel (acrylic/boric acid) for evaluation of the neutron radiation shielding. The influence of acrylic acid concentration, different gamma doses and relative contents of boric acid were studied. The physical properties and the thermomechanical stability of the studied samples were investigated. The shielding property of the composite for neutron was tested by Pu-Be neutron source (5 Ci) under room temperature. The neutron fluence rates and gamma fluxes were measured using a stilbene organic scintillator. The macroscopic effective removal cross-section ΣR (cm-1) of fast neutrons and total attenuation coefficient μ (cm-1) of gamma rays has been studied experimentally. The transmission parameters, the relaxation length (??) and the half-value layer (HVL) were obtained. The obtained results indicated that the addition of boric acid to acrylic acid tends to increase the macroscopic effective removal cross-section ΣR (cm-1) to 0.141 compared to 0.094 of ordinary concrete.

Electrochemical Behavior of Lithium Titanium oxide/activated Carbon Composite for Electrochemical Capacitor

  • Yang, Jeong-Jin;Kim, Hong-Il;Yuk, Young-Jae;Kim, Han-Joo;Park, Soo-Gil
    • Journal of Electrochemical Science and Technology
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    • v.1 no.1
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    • pp.63-68
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    • 2010
  • The $Li_4Ti_5O_{12}$/AC composite was prepared by sol-gel process with ultrasonication. The prepared composite was characterized by SEM, XRD and TG analysis, and their electrochemical behaviors were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge test in 1M $LiBF_4$/PC electrolyte. From the results, the $Li_4Ti_5O_{12}$ particles coated on AC surface had an average particle size of 100 nm and showed spinel-framework structure. When the potential range of the $Li_4Ti_5O_{12}$/AC composite was extended from 0.1 to 2.5 V, redox peaks and electric double layer property were revealed. The initial discharge capacity of $Li_4Ti_5O_{12}$/AC composite was 218 mAh $g^{-1}$ at 1 C. The enhancement of discharge capacity was attributed to electric double layer of added activated carbon.