• Title/Summary/Keyword: H17/28

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The Effect of Residual Stress on Magnetoresistance in GMR Head Multilayers (자기기록 MR 헤드 용 다층박막의 자기저항에 미치는 잔류응력 효과)

  • Hwang, Do-Guwn
    • Journal of the Korean Society for Nondestructive Testing
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    • v.23 no.4
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    • pp.322-327
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    • 2003
  • Giant magnetoresistance(GMR) NiO multilayer, which has been used to reading head of highly dense magnetic recording, was fabricated, and oxidized in an air during 80 days to study the dependence of magnetoresistance properties on residual stress in the interfaces. The magnetoresistance ratio and the exchange biasing $field(H_{ex})$ of $NiO(60nm)/Ni_{81}Fe_{19}(5nm)/Co(0.7nm)/Cu(2nm)/Co(0.7nm)/Ni_{81}Fe_{19}(7nm)$ spin valves were increased from 4.9% to 7.3%, and 110 Oe to 170 Oe after natural oxidation in the atmosphere for 80 days, respectively. The sheet resistivity ${\rho}$ decreased from $28{\mu}{\Omega}m$ to $17{\mu}{\Omega}m$, but ${\Delta}p$ did not almost change after the oxidation. Therefore, the increase of MR ratio is due to the decrease in the sheet resistivity. the reduced resistance may result from the increase in the reflection of conduction electrons at the oxidized top surface. Also, the increase in the exchange biasing field is originated from the reduction of residual stress at the interface of $NiO/Ni_{81}Fe_{19}$ according as the aging time increases.

Miniaturization of Circular Microstrip Antenna Using the Perturbation Effect (Perturbation 효과를 이용한 원형 마이크로스트립 안테나의 소형화)

  • Ryu Mi-Ra;Hur Jung;Woo Jong-Myung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.7 s.110
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    • pp.605-614
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    • 2006
  • In this paper, a 3D structure skimmer-shaped circular microstrip antenna is designed, the ends of whose both sides are made as DC(Depressed Carving part) applying perturbation effect to reduce the patch size of microstrip antenna operating at design frequency 1.575 GHz. The result shows its return loss, - 10 dB bandwidth, gain, - 3 dB beamwidth E, H-plane are -26.59 dB, 65 MHz(4.13 %), 4.66 dBd, $79^{\circ},\;87^{\circ}$ respectively. The diameter of the antenna is 85 mm, which is 12.4 % reduced compared to the size(97 mm) of general microstrip patch antenna. Therefore its area reduction is 23.2 %. Furthermore, a linear and circular polarized baseball-shaped circular microstrip antenna is designed to minimize the patch size of the antenna. This structure of antenna operating at the design frequency 1.575 GHz is applied with the optimum RC(Raised Carving part) & DC ratio and an asymptotic line angle. In case of linear polarized baseball-shaped circular microstrip antenna, the patch size of the antenna is 74 mm, which is 41.8 % area reduction compared to general microstrip patch antenna. In case of circular polarized baseball-shaped circular microstrip antenna, the diameter of patch is 82 mm, which is 28.5 % area reduction compare to general microstrip patch antenna linear polarized. We have verified that the perturbation effect can be applied to minimize the circular microstrip antenna.

Applicability of a Photosynthetic Ciliate, Mesodinium rubrum MR-MAL01 -Usefulness as a Live Prey Species for the Marine Aquaculture of Bivalves- (광합성 섬모류 Mesodinium rubrum MR-MAL01의 응용성(1) 이매패류 종묘생산을 위한 먹이생물 유용성)

  • 김형섭;명금옥;조수근;이원호
    • Journal of Aquaculture
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    • v.17 no.2
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    • pp.115-121
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    • 2004
  • In a series of feeding experiments using the newly established the first laboratory strain of a temperate photosynthetic ciliate, Mesodinium rubrum MR-MAL01, direct evidence was obtained for ingestion of the cultured M. rubrum cells by the bivalves like the Korean scallop, Chlamys farreri and Manila clam. Ruditapes phil-ippinarum. Each experimental Korean scallop and Manila clam removed up to 9,590 and 23,200 cells min-1, respectively. Small particles almost identical to the ruptured cells of MR-MAL01 culture were observed in the gut of the experimental bivalves, although no intact M. rubrum cell was found. In a 28 days rearing experiment, Isoshrysis galbana (KMCC H-2), a microalga, supported better growth of small Manila clam spat (0.46 mm in shell length) than MR-MAL01 strain. For the large Manila clam spat (0.84 mm in shell length), however. MR-MAL01 strain was a better prey item. Mass culture methods for this photosynthetic marine ciliate may be developed for use as live feed in aquaculture of the spat and broodstock of bivalve and small-mouthed fish larvae.

Optimization of Ethanol Extraction Conditions for Functional Components from Lespedeza cuneata Using Response Surface Methodology (반응표면분석법을 이용한 야관문(Lespedeza cuneata) 기능성분의 에탄올 추출조건 최적화)

  • Kim, Dae-Ik;Hong, Joo-Heon
    • Korean journal of food and cookery science
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    • v.28 no.3
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    • pp.275-283
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    • 2012
  • This study was conducted to monitor the quality characteristics of Lespedeza cuneata ethanolic extracts, by a response surface methodology. The independent variables were the extraction temperature ($35{\sim}95^{\circ}C}$), extraction time (2~10 hr), and ethanol concentration (10~90%). The coefficients of the determinations (R2) were 0.8562 (p<0.1), 0.9787 (p<0.01), and 0.8344 (p<0.1) in total polyphenol, total flavonoid, and electron donating ability, respectively. The electron donating ability and nitrite scavenging effect were improved with an increase of ethanol concentration, rather than the extraction temperature. ORAC (Oxygen Radical Absorbance Capacity) with extraction conditions was 1,636.47~2,696.99 ${\mu}moles$ TE/g, and was increased with the increase of extraction temperature and 40~60% of ethanol concentration. Estimated conditions for the maximized extraction including the yield, total polyphenol, electron donating ability, nitrite scavenging effect, and ORAC, were $60{\sim}68^{\circ}C$ in extraction temperature, 6~7 hr in extraction time, and 38~60% in ethanol concentration.

Quality Characteristics of Gamma Irradiated-Grain Shape Improved Meju (감마선 조사된 개량메주의 보존 중 품질특성)

  • Kim, Dong-Ho;Lee, Kyong-Haeng;Yook, Hong-Sun;Kim, Jae-Hoon;Shin, Myung-Gon;Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.640-645
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    • 2000
  • The effect of gamma-irradiation on the quality changes of the grain shape improved Meju was studied. Meju was prepared, irradiated at 0, 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for six months. The results showed that the fungi and acid producing bacteria were completely eliminated by gamma-irradiation with dose of 10 kGy or higher and the Bacillus was decreased by 5 log cycles with dose of 10 kGy. The $D_{10}$ values of the fungi, Bacillus and acid producing bacteria were 0.79, 2.28 and 1.17 kGy, respectively. Also, the microorganisms that survived irradiation was decreased significantly with the duration of storage period. The $NH_3-nitrogen$, negative factors of quality of Meju, and browning were repressed and the protease activity and pH were not affected by gamma-irradiation. Therefore, it was considered that the Meju treated with gamma-irradiation maintained better quality than that of the control with storage.

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Physico-Chemical Characteristics Evaluation of White Pork Rind and Black Pork Rind (백돈피와 흑돈피의 이화학적 품질특성 평가)

  • Jeon, Ki-Hong;Hwang, Yoon-Seon;Kim, Young-Boong;Choi, Yun-Sang;Kim, Byoung-Mok;Kim, Dong-Wook;Jang, Aera
    • The Korean Journal of Food And Nutrition
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    • v.28 no.4
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    • pp.544-550
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    • 2015
  • In order to determine the material characteristics of pork rinds according to the breeds, the chemical composition, color, pH, collagen contents, shear force, fatty acid and amino acid contents of pork rinds were investigated. White pork rinds (WPR) and black pork rinds (BPR) were evaluated before and after heating to compare the differences between breeds and the effects of heating treatment. In the chemical composition test, the respective moisture contents for WPR and BPR before heating were 49.90% and 53.75% but increased to 60.75% and 61.09% after heating. The test for crude protein and crude fat contents showed lower values after heating but WPR was higher than BPR. In the color test, the L value decreased rapidly with heating, dropping from 68.75 to 45.11 in WPR and from 67.22 to 49.64 in BPR. WPR had a higher L value and a lower a value than BPR before heating but had a higher L value and a lower a value than WPR after heating. pH was significantly higher in WPR than BPR regardless of heating (p<0.05). The collagen content for WPR and BPR was 10.38 g/100 g and 11.54 g/100 g but increased to 12.00 g/100 g in WPR and decreased to 11.40 g/100 g in BPR after heating. The shear force of 26.14 kgf in WPR was significantly higher than 12.89 kgf in BPR before heating (p<0.05), but the values decreased significantly after heating in both WPR and BPR. Linoleic acid in WPR was 17.29%, which was higher than 15.13% in BPR. The USFA for BPR was also higher than WPR. In amino acid composition, the EAA contents in WPR was 7,190 mg%, which was higher than 5,520 mg% in BPR.

Physicochemical Properties and Palatability of Loin from Crossbred Jeju Black Pigs (제주도 개량 흑돼지 고기의 이화학적 및 관능적 품질 특성)

  • Moon Yoon-Hee
    • Food Science of Animal Resources
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    • v.24 no.3
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    • pp.238-245
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    • 2004
  • The physicochemical properties and sensory characteristics of loins from crossbred Jeju black pigs from 4 different farms (Jl, J2, J3 and J4) were investigated. The approximate composition of loins were as follows; moisture 73.26∼74.75%, crude protein 22.78∼23.85%, crude fat 0.85∼1.81% and ash 1.23∼1.35%. The unsaturated fatty acid (60.21∼62.33%), pH (5.57∼5.70), water holding capacity (64.22∼69.40%), cooking loss (28.27∼30.45%), Hunter's L* (53.02∼55.64), a* (8.71∼9.87) and b* value (6.95∼7.29) of loins were not significantly different along the 4 samples (p>0.05). The crude fat contents and total amino acid (21.29%) of loin from farm J2 were higher than those from the others, and the hardness and chewiness were lower compared to those from farm Jl (p<0.05). The loin from farm J2 had a good score in sensory characteristics with regard to the taste (5.22), aroma (4.80), tenderness (5.30), juiciness (5.09) and palatability (5.33) of loins evaluated by the 7-point hedonic scale.

Characteristics of Byeok-hyang-ju made by various processing methods originated from ancient documents (고문헌 유래 벽향주의 제조방법에 따른 품질특성)

  • Park, Ji-Hye;Yeol, Soo-Hwan;Jeong, Seok-Tae;Choi, Han-Seok;Jeon, Jin-A;Choi, Ji-Ho
    • Food Science and Preservation
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    • v.17 no.6
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    • pp.826-834
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    • 2010
  • We investigated the temperature changes during processing and quality characteristics of seven preparations of Byeok-hyang-ju described in ancient documents. During fermentation, treatments with intervals longer than 7 days to the second mashing kept temperatures below room temperature. The process with the shortest interval (2 days) between the second and third mashings maintained a preparation temperature above $28^{\circ}C$ for the longest period. As fermentation proceeded, the pH gradually decreased. Titratable acidities increased prior to the second mashing, and then decreased. Amino acid levels increased gradually during all fermentations except for that of method 5 (the lowest level of raw material addition). Ethanol content increased rapidly to the time of second mashing with all methods except method 2. This method featured a short interval between the first and second mashing. Upon sensory evaluation, the best overall acceptability was provided by method 3.

Soil Physical Properties of Arable Land by Land Use Across the Country (토지이용별 전국 농경지 토양물리적 특성)

  • Cho, H.R.;Zhang, Y.S.;Han, K.H.;Cho, H.J.;Ryu, J.H.;Jung, K.Y.;Cho, K.R.;Ro, A.S.;Lim, S.J.;Choi, S.C.;Lee, J.I.;Lee, W.K.;Ahn, B.K.;Kim, B.H.;Kim, C.Y.;Park, J.H.;Hyun, S.H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.3
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    • pp.344-352
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    • 2012
  • Soil physical properties determine soil quality in aspect of root growth, infiltration, water and nutrient holding capacity. Although the monitoring of soil physical properties is important for sustainable agricultural production, there were few studies. This study was conducted to investigate the condition of soil physical properties of arable land according to land use across the country. The work was investigated on plastic film house soils, upland soils, orchard soils, and paddy soils from 2008 to 2011, including depth of topsoil, bulk density, hardness, soil texture, and organic matter. The average physical properties were following; In plastic film house soils, the depth of topsoil was 16.2 cm. For the topsoils, hardness was 9.0 mm, bulk density was 1.09 Mg $m^{-3}$, and organic matter content was 29.0 g $kg^{-1}$. For the subsoils, hardness was 19.8 mm, bulk density was 1.32 Mg $m^{-3}$, and organic matter content was 29.5 g $kg^{-1}$; In upland soils, depth of topsoil was 13.3 cm. For the topsoils, hardness was 11.3 mm, bulk density was 1.33 Mg $m^{-3}$, and organic matter content was 20.6 g $kg^{-1}$. For the subsoils, hardness was 18.8 mm, bulk density was 1.52 Mg $m^{-3}$, and organic matter content was 13.0 g $kg^{-1}$. Classified by the types of crop, soil physical properties were high value in a group of deep-rooted vegetables and a group of short-rooted vegetables soil, but low value in a group of leafy vegetables soil; In orchard soils, the depth of topsoil was 15.4 cm. For the topsoils, hardness was 16.1 mm, bulk density was 1.25 Mg $m^{-3}$, and organic matter content was 28.5 g $kg^{-1}$. For the subsoils, hardness was 19.8 mm, bulk density was 1.41 Mg $m^{-3}$, and organic matter content was 15.9 g $kg^{-1}$; In paddy soils, the depth of topsoil was 17.5 cm. For the topsoils, hardness was 15.3 mm, bulk density was 1.22 Mg $m^{-3}$, and organic matter content was 23.5 g $kg^{-1}$. For the subsoils, hardness was 20.3 mm, bulk density was 1.47 Mg $m^{-3}$, and organic matter content was 17.5 g $kg^{-1}$. The average of bulk density was plastic film house soils < paddy soils < orchard soils < upland soils in order, according to land use. The bulk density value of topsoils is mainly distributed in 1.0~1.25 Mg $m^{-3}$. The bulk density value of subsoils is mostly distributed in more than 1.50, 1.35~1.50, and 1.0~1.50 Mg $m^{-3}$ for upland and paddy soils, orchard soils, and plastic film house soils, respectively. Classified by soil textural family, there was lower bulk density in clayey soil, and higher bulk density in fine silty and sandy soil. Soil physical properties and distribution of topography were different classified by the types of land use and growing crops. Therefore, we need to consider the types of land use and crop for appropriate soil management.

Production and fermentation characteristics of seafood kimchi started with Leuconostoc mesenteriodes SK-1 isolated from octopus baechu kimchi (문어 배추김치에서 분리한 Leuconostoc mesenteroides SK-1을 이용한 수산물김치의 제조 및 발효 특성)

  • Jang, Mi-Soon;Jung, Ko-Eun;Yun, Jae-Ung;Nam, Ki-Ho
    • Food Science and Preservation
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    • v.23 no.7
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    • pp.1050-1057
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    • 2016
  • This study was carried out to investigate the effectiveness of Leuconostoc mesenteroides isolated from octopus baechu kimchi as a potential starter for seafood kimchi. L. mesenteroides is lactic acid bacterium currently used as a starter for kimchi production. We selected the most effective L. mesenteroides strain from the 7 strains isolated from octopus baechu kimchi and, based on biochemical properties and 16S rRNA sequencing, identified the selected strain as L. mesenteroides SK-1. The SK-1 strain exhibited acid-tolerance, good survival capacity, and excellent dextran productivity. We investigated the effects the SK-1 of starter on seafood kimchi fermentation. Octopus baechu kimchi was fermented with L. mesenteroides SK-1 at $4^{\circ}C$ for 35 d. The decrease in pH and increase in acidity in octopus baechu kimchi fermented with the SK-1 starter occurred more quickly than that in the control kimchi indicating that. Octopus baechu kimchi with SK-1 starter has a relatively slow rate of increase in lactic acid production. As a result, octopus baechu kimchi prepared with L. mesenteroides SK-1 can be maintained at a suitable ripening degree over an extended period of time compared to that of the control kimchi, Moreover, the octopus baechu kimchi started with L. mesenteroides SK-1 has excellent sensory properties, including a refreshing taste, and a weak sour odor.