• 제목/요약/키워드: Gel Properties

검색결과 2,543건 처리시간 0.031초

졸-겔법에 의한$ Ta_2$$O_5$ 박막의 전기적 특성 (Electric properties of $ Ta_2$$O_5$ thin films by sol-gel method)

  • 유영각;이준웅
    • E2M - 전기 전자와 첨단 소재
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    • 제10권1호
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    • pp.61-67
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    • 1997
  • We have studied dielectric properties of sol-gel derived tantalum oxide thin films as the insulators. As the sample is annealed from 300.deg. C to 700.deg. C, it is found amorphous below 600.deg. C and crystalline over it. Dielectric constant is maximum(18.6) when Ta$_{2}$O$_{5}$ film was annealed at 400.deg. C. It is found that dielectric strength in Ta$_{2}$O$_{5}$ film annealed at 400.deg. C (1.5MV/cm) increases and then decreases over annealed at 500.deg. C. This phenomenon was attributed to pinhole effect and crystallization. The de conduction properties can be interpreted by Poole-Frenkel effect.ect.

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Effect of La3+ and Ti4+ Ions on the Magnetic Properties of Barium Hexaferrite Powders Synthesized Using Sol-Gel Method

  • Ertus, Emre Burak;Yildirim, Serdar;Celik, Erdal
    • Journal of Magnetics
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    • 제21권4호
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    • pp.496-502
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    • 2016
  • Doped and undoped barium hexaferrite powders ($BaFe_{12}O_{19}$, $Ba_{0.7}Ti_{0.3}Fe_{12}O_{19}$ and $Ba_{0.7}La_{0.3}Fe_{12}O_{19}$) were produced by the sol-gel method. The effects of substituting elements were studied in terms of the magnetic properties of barium hexaferrite powders. The magnetic properties were remarkably changed by the substitution of $La^{3+}$ and $Ti^{4+}$ ions for the $Ba^{2+}$ ion and were accompanied by oxygen deficiency in the $BaFe_{12}O_{19}$. Coercivities ($H_C$) from 4200 to 5100 Oe, remanences ($M_R$) from 22 to 49 emu/g and saturation magnetizations ($M_S$) from 41 to 73 emu/g were obtained for different samples. The obtained results were discussed in detail.

아밀로오스 함량이 다른 옥수수 전분의 겔 형성과 특성 (Formation and Properties of Gel from Maize Starches with Different Amylose Content)

  • 문세훈;신말식
    • 한국가정과학회:학술대회논문집
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    • 한국가정과학회 1997년도 가정과학회 총회 및 학술대회
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    • pp.45-49
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    • 1997
  • 아밀로오스 함량이 다른 옥수수 전분을 $121^{\circ}C$에서 호화시켜 팽윤력과 용해도를 측정했을때, 팽윤력은 찰옥수수 전분인 Amaizo,가 가장 컸고, PFP, Amaizo, Amylomaize Ⅶ 순이었으며 Amaizo의 경우 용출된 겉보기 아밀로오스의 요드 친화력이 가장 높았고, 용해도 역시 높게 나타났다. Brookfield viscometer을 이용하여 0.25N NaOH용액으로 측정한 알칼리 호화양상은 Amylomaize Ⅶ이 최고점도 $10{\pm}10^3cp$를 나타낸 반면 Amaizo는 $70{\pm}10^3cp$로 Amylomaize Ⅶ에 비해 높은 값을 나타냈고, PFP는 70$\times$$10^3$까지 증가했다가 감소하였다. 전분과 물을 1 : 9로 하여 $121^{\circ}C$에서 가열-냉각 횟수를 4회 반복하며, 각 단계에서 형성된 겔의 성질을 비교하면 Amaizo로 만든 겔의 견고성, 부착성, 탄성과 옹집성이 가장 컸으며, 견고성은 가열-냉각처리를 2회 반복한 경우 가장 컸고 그 후 감소하였다. 옥수수전분 겔의 성질은 아밀로오스 함량보다는 사슬길이나 가열 중 용출되는 부분의 성질에 더 상관성이 높았다.

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Effect of Acetylated Rice Starch on Rheological Properties of Surimi Sol and Gel

  • Jung, Young-Hwa;Kim, Won-Woo;Yoo, Byoung-Seung
    • Food Science and Biotechnology
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    • 제16권5호
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    • pp.817-821
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    • 2007
  • The effect of acetylated rice (AR) starch at different concentrations (0, 4, 6, and 8%) on rheological properties of surimi sols and gels was studied. Dynamic frequency sweeps of surimi-AR starch sols at $10^{\circ}C$ showed that the magnitudes of storage moduli (G') decreased with an increase in starch concentration while those of tan ${\delta}$ increased, indicating that the effect of AR starch on the viscoelastic properties of surimi sols depended on starch concentration. In general, the G' thermograms of surimi sols showed the similar sol-gel transition pattern and they were also influenced by the addition of AR starch. The presence of AR starch in the surimi gel system reduced the gel strength and expressible moisture content (EMC). Surimi-AR starch gels showed better freeze-thaw stability compared to the control (0% starch concentration). The effect of AR starch on the rheological properties of surimi sols and gels appeared to be related to the swelling ability of starch granules in the presence of limited water available for starch.

남극 크릴(Euphausia superba) 연육의 물성에 대한 첨가제의 영향 (Effects of Additives on the Physical Properties of Antarctic Krill Euphausia superba Surimi)

  • 채연주;최은혜;이양봉;전병수;김선봉
    • 한국수산과학회지
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    • 제47권4호
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    • pp.347-355
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    • 2014
  • This study examined the effects of additives on the physical properties of surimi made from Antarctic krill Euphausia superba. Krill surimi was prepared from krill meat with an added cryoprotectant (sugar 6%, polyphosphate 0.2%). Krill surimi without additives does not form a gel. In order to enhance the gelling of krill surimi, additives such as soy protein isolate (SPI), guar gum, carrageenan, and wheat starch were examined. Of these, SPI had the highest gel-forming activity, while guar gum, carrageenan, and wheat starch had decreasing gel-forming activity and negative effects on other physical properties as their concentrations were increased. In addition, SPI enhanced the gel strength and physical properties of krill surimi. The fluoride and astaxanthin contents of krill surimi with added SPI were 55.0 mg/kg and 0.8 mg/kg, respectively.

Tunable 소자 응용을 위한 Sol-gel 법으로 제작된 BST 박막의 Bi 첨가에 따른 구조적, 유전적 특성 (Structure and Dielectric properties of BST Thin Films prepared by Sol-gel method for Tunable element application)

  • 김태형;김경태;김창일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.565-568
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    • 2004
  • An alkoxide-based sol-gel method was used to fabricate $Ba_{0.6}Sr_{0.4}TiO_3$ thin films doped by Bi from 5 to 20 mol% on a Pt/Ti/SiO2/Si substrate. The structural and dielectric properties of BST thin films were investigated as a function of Bi dopant concentration. The dielectric properties of the Bi doped BST films were strongly dependent on the Bi contents. The dielectric constant and dielectric loss of the films decreased with increasing Bi content. However, the leakage current density of the 10 mol% Bi doped $Ba_{0.6}Sr_{0.4}TiO_3$ thin film showed the lowest value of 5.13 10-7 at 5 V. The figure of merit (FOM) reached a maximum value of 32.42 at a 10 mol% Bi doped $Ba_{0.6}Sr_{0.4}TiO_3$ thin films. The dielectric constant, loss factor, and tunability of the 10 mol% Bi doped $BBa_{0.6}Sr_{0.4}TiO_3$ thin films were 333,0.0095, and 31.1%, respectively.

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Phase shifters 응용을 위한 Sol-gel 법으로 제작된 PST 박막의 Pb/Sr 비에 따른 구조적, 유전적 특성 (Structure and Dielectric properties of PST Thin Films with Pb/Sr ratio prepared by Sol-gel method for Phase shifter)

  • 이철인;김경태;김창일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.794-797
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    • 2004
  • The object of investigation is represented by PbxSrl-xTiO3(PST) thin films, which were fabricated by the alkoxide-based sol-gel method on Pt/Ti/SiO2/Si substrate. We have investigated both structural and dielectric properties of PST thin films aimed to tunable microwave device applications as a function of Pb/Sr ratio. PST thin films showedtypical polycrystalline structure with a dense microstructure without secondary phase formation. Dielectric properties of PST films were found as strongly dependent on Pb/Sr composition ratio. Increasing of Pb content leads to simultaneous increasing of both dielectric constant and dielectric loss characteristics of PST films. The figure of merit (FOM) Parameter (FOM : (%) tunability / tan (%)) reached a maximal value of 27.5 corresponding to Pb/Sr ratio of 40/60. The tunability increased with increasing Pb content. The dielectric constants, dielectric loss and tunability of the PST thin films at Pb/sr ratio of 40/60 measured at 100 kHz were 335, 0.0174 and 47.89 %, respectively.

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Sol-gel법으로 제조된 Tb-doped PZT(60/40) 박막의 강유전 특성 (Ferroelectric properties of sol-gel derived Tb-doped PZT thin films)

  • 손영훈;김경태;김창일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.51-54
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    • 2003
  • Tb-doped lead zirconate titanate($Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_3$; PZT) thin films on $Pt(111)/Ti/SiO_2/Si(100)$ substrates prepared by a sol-gel method. Films have a Zr/Ti ratio of 60:40 and perovskite phase structure. The effect on the structural and electrical properties of films measured according to Tb content. Dielectric and ferroelectric properties of PZT thin films were altered significantly by Tb-doping. The PZT thin film with higher dielectric constant and improved leakage current characteristic was obtained by adding 0.3 mol% Tb. At 100 kHz, the dielectric constant and the dielectric loss of the 0.3 mol% Tb-doped PZT thin film were 1611 and 0.24, respectively The remanent polarization(2Pr) of the 0.3 mol% Tb-doped PZT thin film was $61.4\;{\mu}C/cm^2$ and the coercive field was 61.9 kV/cm. Tb-doped PZT thin films showed improved fatigue characteristics comparing to the undoped PZT thin film.

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Effects of konjac gel with vegetable powders as fat replacers in frankfurter-type sausage

  • Kim, Dong Hyun;Shin, Dong Min;Seo, Han Geuk;Han, Sung Gu
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권8호
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    • pp.1195-1204
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    • 2019
  • Objective: The purpose of this study was to investigate whether addition of konjac gel with three different vegetable powders can increase quality of low-fat frankfurter-type sausage. Methods: Low-fat frankfurter-type sausages were manufactured with formulations containing konjac gel and three vegetable powders (aloe vera, cactus pear, or wheat sprout) as pork fat replacers. The formulations of frankfurters were as follows: NF (normal-fat; 20% pork fat), LF (low-fat; 10% pork fat), KG (low-fat; 10% pork fat+10% konjac gel), and konjac gel with three vegetable powders (KV), such as KV-AV (10% pork fat+10% konjac gel with aloe vera), KV-CP (10% pork fat+10% konjac gel with cactus pear), and KV-WS (10% pork fat+10% konjac gel with wheat sprout). Proximate analysis, pH value, color evaluation, cooking loss, water-holding capacity, emulsion stability, apparent viscosity, texture profile analysis, and sensory evaluation were determined. Results: The konjac gel containing groups showed lower fat content (p<0.05) and higher moisture content than NF group (p<0.05). The pH value of frankfurters was decreased in three KV groups (p<0.05). The three KV groups had increased dark color (p<0.05) compared with KG, and KV-CP had the highest redness (p<0.05). The water-holding capacity and emulsion stability were higher in the three KV groups than KG and LF (p<0.05). Cooking loss was generally decreased in the three KV groups, compared with KG (p<0.05). The apparent viscosity of KV groups was similar with NF group and overall texture properties were improved in KV-CP. In the sensory evaluation, the highest overall acceptability was found in KV-CP groups (p<0.05). Conclusion: The four fat replacers improved physicochemical properties of low-fat frankfurters. Particularly, konjac gel with cactus pear powder seems more acceptable as a pork fat replacer.