• Title/Summary/Keyword: H-B grade

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Comparative Study of Microstructure and Tensile Properties of 600 and 700 MPa-Grade High-Strength Seismic Resistant Reinforced Steel Bars (내진용 600 및 700 MPa 급 고강도 철근의 미세조직과 인장 특성 비교)

  • Hong, T.W.;Lee, S.I.;Lee, J.H.;Shim, J.H.;Lee, M.G.;Hwang, B.
    • Transactions of Materials Processing
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    • v.27 no.5
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    • pp.281-288
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    • 2018
  • This study deals with the microstructure and tensile properties of 600 and 700 MPa-grade high-strength seismic reinforced steel bars. High-strength seismic resistant reinforced steel bars (SD 600S and SD 700S) were fabricated by TempCore process, especially the SD 700S specimen was more rapid cooled than the SD 600S specimen during the TempCore process. Although two specimens had microstructure of tempered martensite in the surface region, the SD 600S specimen had ferrite-degenerated pearlite in the center region, whereas the SD 700S specimen had bainite-ferrite-degenerated pearlite in the center region. Therefore, their hardness was highest in the surface region and revealed a tendency to decrease from the surface region to the center region because tempered martensite has higher hardness than ferrite-degenerated pearlite or bainite. The SD 700S specimen revealed higher hardness in the center region than SD 600S specimen because it contained a larger amount of bainite as well as ferrite-degenerated pearlite. On the other hand, tensile test results indicated the SD 600S and SD 700S specimens revealed continuous yielding behavior because of formation of degenerated pearlite or bainite in the center region. The SD 600S specimen had a little higher tensile-to-yield ratio because the presence of ferrite and degenerated pearlite in the center region and the lower fraction of tempered martensite enhance work hardening.

Development of a Non-invasive Ultrasonic Measurement System for tissue elasticity (비침습적 초음파 조직 탄성도 측정 시스템 개발)

  • Lee, G.J.;Choi, W.H.;Yu, J.W.;Seo, J.B.;Choi, S.H.;Shin, T.M.
    • Journal of Biomedical Engineering Research
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    • v.30 no.6
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    • pp.469-475
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    • 2009
  • Diseases caused by indurate tissues of the internal organs are liver cirrhosis and abdominal sclerosis. The cause of chronic gastro-intestinal disease is a digestive system disorder and a defecation disorder. They impede peristaltic movement and digestive system with the symptom that indurate tissues. The purpose of the present study was to determine the disease grade quantitatively by measuring an indurated standard of tissues and organs. For the measurement of elasticity, we designed the system that measure the displacement of the substance and approved pressure using ultrasound transducer. For verification of developed system, we compared elasticity as results of experiment between the developed system and public elasticity measurement machine at individual plastic phantoms made by plastic hardener and softener. Elasticity of the plastic phantoms is averagely 0.007MPa lower measured by developed system than Micro-indenter, and less than 10% errors. Comparing with economical value and accuracy between developed system and Micro-indenter, the system is significant of measurement for tissue elasticity. Thus, it is possible to measure a elasticity at human tissue and organ. A chronic gastro-disease as well as grade could be decided objective validity using this system.

The Fabrics Dyeing using Gromwell Roots (자초 뿌리를 이용한 직물의 염색에 관한 연구)

  • 안경조;김정희;유혜자
    • Journal of the Korean Home Economics Association
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    • v.41 no.1
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    • pp.249-257
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    • 2003
  • For the efficiency in extracting gromwell colorant, methanol, ethanol and aceton were used as solvents. Also, to compare the results when dyed in various conditions and on various fabrics, the ratio of water-dye mixture, pH, temperature, and varieties of fabrics -wool, silk, cotton, nylon, ramie- were selected. L, a, b, ΔE, munsell and K/S value of each sample was measured and compared for the practical use. Water-dye mixture of 5:5 ratio showed the optimum dyeability. Not to mention wool and silk, but also cotton showed a satisfying dying result at the acidity of pH4. As the temperature increased, the dyeability of all three fabrics improved greatly. Especially, wool showed the highest improvement in terms of dyeability as the temperature increased. K/S values for wool and nylon showed superior results to the others in the gromwell colorant. The resulting color turned out somewhat different depending on the solvents used and the sort of fabric that was tested on. When the gromwell colorant extracted with methanol or ethanol was applied, the color of fabrics came out as purple or purpleblue. When the colorant extracted with acetone was used, the color of fabrics came out to be redpurple. The colorfastness to light showed low glades regardless to whichever solvents were used. The grades of colorfastness to laundering were recorded low numerical values, and its record became even lower when the gromwell colorant extracted with aceton was applied. The staining grade of the colorfastness to laundering showed a good grade in the range of 4 to 5. All the dyed fabrics showed a excellent drycleaning fastness.

Characterization and Anti-Gastric Ulcer Activity of Bamboo Salt (죽염의 특성 분석과 항위궤양효과)

  • 김승희;강석연;정기경;김태균;한형미;류항묵;문애리
    • Journal of Food Hygiene and Safety
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    • v.13 no.3
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    • pp.252-257
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    • 1998
  • Bamboo salt has been used as a traditional remedy for gastric ulcer and gastro-intestinal disorders. It is produced by baking the salt packed in bamboo cylinder nine times under the fire of pine tree. Three of commercially available bamboo salt products (bamboo salt A, B, and C) were characterized by qualitative and quantitative analyses using inductively coupled plasma (ICP) spectrometer, ion chromatograph (IC), X-ray diffractometer (XRD), and electron microscope (EM). Compared with crude salt, the contents of iron, silicon, potassium, and phosphate in the bamboo salt products were higher whereas the sulfate content was lower. Water-insoluble fraction of bamboo salts contained the following compounds; MgO, $SiO_2,\;Mg_2Si0_4,\;and\;CaMgSi0_4$. The study on the microscopic structures of the bamboo salts were shown to have smooth surface and fused shape compared with crude salt. Among the three bamboo salt products, product A was used to test a possible inhibitory effect on gastric acid secretion. Each test material (bamboo salt A, crude salt, and reagent-grade NaCl) was given orally to Sprague-Dawley rats at doses of 0.2, 1.0, and 2.0 g/kg for 28 days before pyrolus ligation. Twenty four hours after the last administration of the test materials, volume, pH, total acidity, and pepsin activity of gastric juice were measured by the Shay-ligation method. No significant differences were observed in the secretion of gastric acid between treated groups (bamboo salt-, crude salt- and reagent-grade NaCI-treated groups) and control group (distilled water-treated group). This result demonstrated that bamboo salt did not exert anti-ulcer activities in experimental animals used in the present study.

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Distribution of Vascular Plants in Gongdeoksan (Mungyeong, Gyeongbuk) (공덕산(경북 문경) 관속식물의 분포)

  • Jeong, G.Y.;Park, M.S.;Jeong, S.Y.;Lee, S.H.;Choi, H.N.;Nam, B.M.;Lee, Y.M.;Choi, H.J.
    • Korean Journal of Plant Resources
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    • v.21 no.4
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    • pp.270-280
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    • 2008
  • This study was carried out to clarify the distribution of vascular plants and their usefulness in Gongdeoksan of Mungyeong, Gyeongbuk (913m, N $36^{\circ}$ $46^{\prime}$ $37.5^{\prime\prime}$${\sim}$$36^{\circ}$ $43^{\prime}$ $61.0^{\prime\prime}$, $E128^{\circ}$ $15^{\prime}$ $00.3^{\prime\prime}$${\sim}$$128^{\circ}$ $17^{\prime}$ $57.9^{\prime\prime}$). The vascular plants collected 5 times (from May to September 2007) were consisted of total 429 taxa; 86 famailies, 279 genera, 374 species, 4 subspecies, 44 varieties and 7 forms. Among them, edible, medicinal, industrial, ornamental and usefulness unknown plants were 233 taxa, 297 taxa, 113 taxa, 111 taxa, 43 taxa, respectively. Korean endemic plants of this area were 5 taxa, and Law-protected plants by Ministry of Environment were 1 taxa, and the special plants species based on floral region by Ministry of Environment were 5 taxa in grade III category, 1 taxa in grade IV and grade V category. The naturalized plants were 15 taxa, therefore naturalized ratio was 3.5%, and urban index 5.5%.

Evaluation of Fermentation Ability of Microbes for Corn Silage Inoculant (옥수수 사일리지용 미생물의 발효능력 평가)

  • Kim, Jong-Geun;Ham, Jun-Sang;Chung, Eui-Soo;Seo, Sung;Park, Hyung-Soo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.30 no.4
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    • pp.333-342
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    • 2010
  • Corn is very important forage in Korea. The great part of them is utilized as silage. Generally, it contains a lot of grains that is feed of animal. This experiment was conducted to evaluation of fermentation ability of microbes for corn silage inoculant. Good lactic acid bacteria were isolated from good corn silage by plating MRS agar containing 0.02% sodium azide, and assessed by growing and acid producing ability in MRS broth. Six lactic acid bacteria were selected, and were found to be Gram positive, rods and catalase negative and were identified to be lactobacillus plantarum (C3-2, B13-1, CC9-1), Lactobacillus fermentum (C11-4), Lactobacillus paracasei (B14-1), and Leuconostoc lactis (A3-1) on the basis of the biochemical characteristics and utilization of substrates. Corn was ensiled at ripen stage following treatment with selected five lactic acid bacteria, two commercial inoculant, and no additive (control). After 2 month, B13-1 and CC9-1 bacteria inoculated silage were lower pH and higher lactic acid content than others treatments. The Flieg's score and grade of B13-1 and CC9-1 bacteria treated silage were higher than commercial inoculant. According to this experiment, lactobacillus plantarum B13-1 and CC9-1 strain were recommendable for good inoculant of corn silage.

Studies on the Organic Tiers Contained paddy Soils in Honam Area -II. Studies on the physicochemical characteristics of Organic Tiers and bearing power of soils (유기질토층(有機質土層)을 함유(含有)한 호남지역(湖南地域) 답토양(畓土壤)에 관(關)한 연구(硏究) -II. 유기질토층(有機質土層)의 이화학적(理化學的) 특성(特性) 및 토양(土壤)의 지지력(支持力))

  • Yoo, Chul-Hyun;Cho, Guk-Hyun;Choi, Jeong-Weon;Kim, Han-Myoung;Park, Keon-Ho;Um, Ki-Tae
    • Korean Journal of Soil Science and Fertilizer
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    • v.19 no.3
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    • pp.187-194
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    • 1986
  • Present stadies were carried out to obtain fundermental data for effective management of the soils by investigating the physicochemical characteristics rubber fiber, humification grade and bearing power of peats and muck which were included in Geongdeog series, and Gimje series in Honam area. The results abtained were as follows; 1. Humification grade of peats were about 23, while that of muck soils was about 45-71 and those were higher in Gimje series than Bongnam series. 2. The organic tiers which humification grade was higher were high pH, bulk density, and contents of K, $P_2O_5$, B.S and while were low OM, T-C, T-N, Na, $SiO_2$ and rubbed fiber. 3. In peats and mucks, bulk density, pH, contents of T-N $P_2O_5$ and ash were negatively correlated with rubbed fiber and OM, CEC, T-C, PAC, C/N, C/P were positively correlated with one, while these physicochemical characteristics were oppositely correlated with humification grade. 4. Cone bearing power of each soil tiers was low in every Geongdeog series which had the thick organic tiers and showed poorly drainage and it was the highest in Gimje series which was similar to in organic soils because of its thin organic tiers.

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Synthesis and Formation Mechanism of Cobalt Doped Willemite Blue Pigments (Co-Doped Willemite 파란색 안료의 합성과 생성기구)

  • Hwang, Dong-Ha;Han, Kyong-Sop;Lee, Byung-Ha
    • Journal of the Korean Ceramic Society
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    • v.47 no.6
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    • pp.603-607
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    • 2010
  • Turquoise blue pigment of Vanadium-zircon blue (DCMA number 14-42-2), which was already commercialized, was stable to be reproduced but insufficient to give strong blue. However, it possible to obtain more intense blue by partially substituting cobalt ions into the willemite($Zn_2SiO_4$) lattice classified into DCMA number 7-10-2 for blue ceramic pigment. By the composition of willemite $Co_xZn_{2-x}SiO_4$(X=0.01, 0.03, 0.05, 0.07, 0.09 mole), this study used reagent grade zinc oxide, cobalt oxide and silicon dioxide as starting materials, carrying out the synthesis with solid reaction method by adding $H_3BO_3$ as a mineralizer. The firing temperature was between $1200^{\circ}C$ and $1400^{\circ}C$. The characteristics of synthesized pigment were analyzed by X-ray diffraction, Raman spectroscopy and SEM and the characteristics of color tones were analyzed by UV-Vis spectroscopy and CIE-$L^*a^*b^*$ measurement. As a result, the optimal composition was $Zn_{1.95}Co_{0.05}$ with 1wt% of $H_3BO_3$ as a mineralizer and firing condition was $1350^{\circ}C$/3 h. $L^*a^*b^*$ value was 29.25, 41.03, -59.93 for on glaze pigment and 37.03, 36.41, -60.03 for under glaze pigment.

Effects of a Dietary Chitosan-Alginate-Fe(II) Complex on Meat Quality of Pig Longissimus Muscle during Ageing

  • Park, B.Y.;Kim, J.H.;Cho, S.H.;Hwang, I.H.;Jung, O.S.;Kim, Y.K.;Lee, J.M.;Yun, S.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.3
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    • pp.414-419
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    • 2005
  • The current study was conducted to investigate the effects of dietary chitosan-alginate-Fe(II) complex (CAFC) supplementation on carcass and meat qualities of pig m. longissimus during chiller ageing. One hundred and twenty-two LYD (Landrace${\times}$Yorkshire${\times}$Duroc) pigs were sampled from an industrial population. Seventy-four pigs (32 gilts and 42 barrows) were administered 3 ml of dietary supplementation of CAFC per day from 25 to 70 days of age, while the remaining 48 pigs (20 gilts and 28 barrows) were fed the same commercial feeding regime without the supplementation. For assessing the dietary effects on pH, objective meat color, cooking loss, water-holding capacity (WHC), thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen (VBN) and fatty acid composition during ageing, 20 barrows (10 of each treatment) were randomly sampled, and aged for 3, 7, 12, 16, 20 and 25 days in a $1^{\circ}C$ chiller. The results showed that CAFC-fed pigs required approximately 10 fewer feeding days than the control group. Furthermore, the treatment resulted in greatly higher carcass grade whereby the grade A was increased by approximately 35% and 7% for gilts and barrows, respectively. The treatment had no significant effect (p>0.05) on pH, meat color and WHC during ageing. On the other hand, the CAFC-fed pigs showed significantly (p<0.05) lower TBARS values from 20 days of storage. In addition, the sum of unsaturated fatty acids for the treated group was significantly (p<0.05) higher than that for the control group after the storage time. This implied that CAFC supplementation could reduce the formation of free radicals in fatty acids (i.e., lipid oxidation). The treatment also significantly (p<0.05) retarded VBN formation during ageing, indicating a significant reduction in protein degradation. However, as there was no difference in pH between the two groups, the result raised a possibility that antibacterial activity of the CAFC alone could cause reduction in the formation of TBARS and VBN. In this regard, although the treatment effectively slowed down the formation of TBARS and TBA during chiller ageing, it was not resolved whether that was associated with the direct effect of the antioxidant function of chitosan and/or alginate, or a consequence of their antibacterial functions.

Effect of stress during slaughter on carcass characteristics and meat quality in tropical beef cattle

  • Carrasco-Garcia, Apolo A.;Pardio-Sedas, Violeta T.;Leon-Banda, Gloria G.;Ahuja-Aguirre, Concepcion;Paredes-Ramos, Pedro;Hernandez-Cruz, Bertha C.;Murillo, Vicente Vega
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.10
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    • pp.1656-1665
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    • 2020
  • Objective: This study aimed to determine the effects of stress during slaughter of beef cattle on physiological parameters, carcass, and meat quality at a Federal Inspection Type slaughterhouse located in the southeast of Mexico. Methods: A total of 448 carcasses of male Zebu×European steers with an average age of 36 months were included. Carcass assessment of presence of bruises and bruise characteristics was carried out on each half-carcass. Blood variable indicators of stress (packed cell volume, neutrophil to lymphocyte ratio, glucose, cortisol concentration) and meat quality parameters (pH, color, shear force, drip loss) were evaluated. Results: Of the 448 carcasses evaluated, 81% of the carcasses showed at least one bruise; one bruise was detected in 36.6% and two bruises in 27.0% of animals. Of the 775 bruises found, 69.2% of the bruises were grade 1 in region 3. Of the 448 carcasses studied, 69.6% showed hyperglycemia (6.91 mmol/L); 44.3% and 22.7% showed high (74.7 ng/mL) and extremely high (108.8 ng/mL) cortisol levels, respectively, indicative of inadequate handling of animals during preslaughter and slaughter. Of the carcasses evaluated, 90.4% had a pH ≥5.8 with an average of pH 6.3. In both pH groups, meat samples showed L values >37.0 (81.6%) and a shear force >54.3 N; meat pH≥5.8 group showed a drip loss of 2.5%. These findings were indicative of dark, firm, and dry (DFD) meat. According to principal component analysis, grades 1 and 2 bruises in region 3 and grade 1 bruises in region 5 were highly associated with cortisol, drip loss, and color parameters b and h and were negatively associated with L, a, and C. Conclusion: The bruises probably caused by stress-inducing situations triggered DFD meat. Appropriate changes in handling routines in operating conditions should be made to minimize stress to animals during the slaughter process to improve animal welfare and meat quality.