• Title/Summary/Keyword: 전단 특성

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Effect of Dietary Supplementation of Dried-Citrus Pulp and Wheat Bran on Growth and Meat Quality in Horses (건조감귤박 및 소맥피를 급여한 말의 성장과 육질에 미치는 영향)

  • Chae, Hyun-Seok;Kim, Nam-Young;Cho, In-Chul;Cho, Sang-Rae;Cho, Won-Mo;Park, Yong-Sang;Oh, Shin-Ae;Jang, Aera;Seong, Pil-Nam;Ko, Moon-Suck
    • Journal of Animal Science and Technology
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    • v.55 no.3
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    • pp.219-227
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    • 2013
  • This study was conducted to elucidate the characteristics of equine meat traits and to evaluate the utilization of dried-citrus pulp abundantly produced in Jeju Island as feed ingredient in the diet of finished meat horses. Treatment groups consisted of wheat bran (A) and the dried-pellet mixture of citrus pulp (20%) and wheat bran (80%) (B). Feeding of agricultural by-products were 2 times in a day at the level of 1.5% of body weights. Water and dried-grass forage was not restricted. The average daily gain was similar in both groups. Feed conversion of treatment B showed lower level than that of A. Carcass rate of B was relatively lower than that of A, but meat yield grade of B was higher than that of A. For meat color traits, $L^*$ of B was lighter than that of A, and $b^*$ of group B was lower than that of group A. From the analysis of physical characteristics of equine meats, shearing force had decreased in the treatment B but the levels of drip loss and water holding cavity had increased in the treatment B compared to A. The level of crude fat is lower in the treatment B than the treatment A. For the mineral contents, the treatment B showed higher levels of Ca, K, Mg, Cu and Mn than that of A. For the fatty acid contents, the treatment B showed increased levels of stearic acid, oleic acid, eicosenoic acid, and arachidonic acid compared to A. Consequently, these results suggested that dried-citrus pulp might be utilized as replacement material for equine forage. Please rewrite the whole abstract and should include all required information. Before resubmission, please check it again from a native colleague in your group.

Dynamics of Barrel-Shaped Young Supernova Remnants (항아리 형태 젊은 초신성 잔해의 동력학)

  • Choe, Seung-Urn;Jung, Hyun-Chul
    • Journal of the Korean earth science society
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    • v.23 no.4
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    • pp.357-368
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    • 2002
  • In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

Mesothermal Gold Vein Mineralization of the Seolhwa Mine: Fluid Inclusion and Sulfur Isotope Studies (설화 광산의 중열수 금광화작용: 유체포유물 및 황동위원소 연구)

  • Yun, Seong-Taek;So, Chil-Sup;Choi, Seon-Gyu;Choi, Sang-Hoon;Heo, Chul-Heo
    • Journal of the Korean earth science society
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    • v.22 no.4
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    • pp.278-291
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    • 2001
  • Mesothermal gold vein minerals of the Seolhwa mine were deposited in a single stage of massive quartz veins which filled the mainly NE-trending fault shear zones exclusively in the granitoid of the Gyeonggi Massif. The Seolhwa mesothermal gold mineralization is spatially associated with the Jurassic granitoid of 161 Ma. The vein quartz contains three main types of fluid inclusions at 25$^{\circ}$C: 1) low-salinity (< 5 wt.% NaCl), liquid CO$_{2}$-bearing, type IV inclusion; 2) gas-rich (> 70 vol.%), aqueous type II inclusions; 3) aqueous type I inclusions (0${\sim}$15 wt.% NaCl) containing small amounts of CO$_{2}$. The H$_{2}$O-CO$_{2}-CH$_{4}$-N$_{2}$-NaCl inclusions represent immiscible fluids trapped earlier along the solvurs curve at temperatures from 430$^{\circ}$ to 250$^{\circ}$C and pressures of 1 kbars. Detailed fluid inclusion chronologies may suggest a progressive decrease in pressure during the auriferous mineralization. The aqueous inclusion fluids represent either later fluids evelved through extensive fluid unmixing (CO$_{2}-CH$_{4}$ effervescence) from a homogeneous H$_{2}$O-CO$_{2}-CH$_{4}$-N$_{2}$-NaCl fluid due to decreases in temperature and pressure, or the influence of deep circulated meteoric waters possibly related to uplift and unloading of the mineralizing suites. The initial fluids were homogeneous containing H$_{2}$O-CO$_{2}-CH$_{4}$-N$_{2}$-NaCl components and the following properties: the initital temperature of >250$^{\circ}$ to 430$^{\circ}$C, X$_{CO}\;_{2}$ of 0.16 to 0.62, 5 to 14 mole% CH$_{4}$, 0.06 to 0.3 mole% N$_{2}$ and salinities of 0.4 to 4.9 wt.% NaCl. The T-X data for the Seolhwa gold mine may suggest that the Seolhwa auriferous hydrothermal system has been probably originated from adjacent granitic melt which facilitated the CH$_{4}$ formation and resulted in a reduced fluid state evidenced by the predominance of pyrrhotite. The dominance of negative ${\delta}\;^{34}$S values of sulfides (-0.6 to 1.4$%_o$o) are consistent with their deep igneous source.

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Delayed Diagnosis of Primary Lung Cancer (원발성 폐암의 지연진단에 관한 임상적 고찰)

  • Kim, Sun-Young;Cho, Hae-Jeong;Kim, Geun-Hwa;Ko, Dong-Seok;Suh, Jae-Chul;Shin, Kyoung-Sang;Jeong, Seong-Su;Kim, Ju-Ock
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.4
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    • pp.754-759
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    • 1998
  • Background : Lung cancer is an important public health problem because of rapidly increasing malignancy in both sexes in relation with high smoking rate in Korea. Despite advances in therapeutic modalities and supportive cares, 5-year survival rate has improved only marginally during the past 2 decades. Therefore, the early detection of lung cancer is strongly needed for better prognosis and we conducted this study to review the clinical factors resulting in delayed diagnosis of lung cancer. Method: The clinical data such as presenting symptoms, duration for diagnosis, disease entities causing misdiagnosis or delayed diagnosis, were analyzed retrospectively in 154 patients with primary lung cancer diagnosed at Chungnam National university hospital from January to December in 1995. Results : 63 patients(40.9%) out of 154 patients were delayed diagnosed with the duration of 6.3 months compared with 3.6 months in patients diagnosed without delay. In delayed diagnosed group, Cough & sputum and dyspnea as presenting symptom were more critical than hemoptysis and chest pain, and doctor's delay was more critical than patient's delay. Tuberculosis(30/63) was most frequent disease entity causing delayed diagnosis, followed by pneumorua(9/63), COPD(6/63), heart diseases(5/63), etc.. Conclusion: It should be emphasized that any respiratory symptom be checked with chest X-ray to differentiate lung cancer and periodic check of chest X-ray be also needed for the longterm patients with any disease, especially with high risk group.

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An Experimental Study on Optimum Slanting Angle in Reticulated Root Piles Installation (그물식 뿌리말뚝의 최적 타설경사각에 관한 실험 연구)

  • 이승현;김병일
    • Geotechnical Engineering
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    • v.11 no.2
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    • pp.29-36
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    • 1995
  • Load testis are executed on model reticulated root piles (RRP) to figure out the optimum slanting angle in the piles installation. One set of model RRP consists of 8 slanting piles which are installed in circular patterns forming two concentric circles, each of which is made by 4 piles. Each pile which is a steel bar of 5m in diameter and 300mm in length is coated to become a pile of 6.5mm in diameter. The slanting angle of the model RRP varies from 0$^{\circ}$ to 20$^{\circ}$ Comparing ultimate bearing capacities of the model RRP of different installation angles, it is observed that the ultimate capacities of the RRP increase as the installation angle increases until 15$^{\circ}$, and the optimum slanting angle of the RRP is around 15$^{\circ}$ The ultimate bearing capacity of the 15$^{\circ}$-RRP is found to be 22% bigger than that of the vertical RRP and 120% bigger than that of the circular surface footing whose diameter is same with the circle formed by outer root piles'heads. However, it is noticed that when the slanting angle of the RRP is increased over 15$^{\circ}$, the ultimate capacity starts to be reduced. The ultimate capacity of 20$^{\circ}$-RRP is even smaller than that of the vertical RRP by as much as 5%. From the observation of the load settlement curve obtained during the RRP load tests, it is known that as the slanting angle gets bigger the load -settlement behavior becomes more ductile.

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Cyclic Seismic Testing of Cruciform Concrete-Filled U-Shape Steel Beam-to-H Column Composite Connections (콘크리트채움 U형합성보-H형강기둥 십자형 합성접합부의 내진성능)

  • Park, Chang-Hee;Lee, Cheol-Ho;Park, Hong-Gun;Hwang, Hyeon-Jong;Lee, Chang-Nam;Kim, Hyoung-Seop;Kim, Sung-Bae
    • Journal of Korean Society of Steel Construction
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    • v.23 no.4
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    • pp.503-514
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    • 2011
  • In this research, the seismic connection details for two concrete-filled U-shape steel beam-to-H columns were proposed and cyclically tested under a full-scale cruciform configuration. The key connecting components included the U-shape steel section (450 and 550 mm deep for specimens A and B, respectively), a concrete floor slab with a ribbed deck (165 mm deep for both specimens), welded couplers and rebars for negative moment transfer, and shear studs for full composite action and strengthening plates. Considering the unique constructional nature of the proposed connection, the critical limit states, such as the weld fracture, anchorage failure of the welded coupler, local buckling, concrete crushing, and rebar buckling, were carefully addressed in the specimen design. The test results showed that the connection details and design methods proposed in this study can well control the critical limit states mentioned above. Especially, the proposed connection according to the strengthening strategy successfully pushed the plastic hinge to the tip of the strengthened zone, as intended in the design, and was very effective in protecting the more vulnerable beam-to-column welded joint. The maximum story drift capacities of 6.0 and 6.8% radians were achieved in specimens A and B, respectively, thus far exceeding the minimumlimit of 4% radians required of special moment frames. Low-cycle fatigue fracture across the beam bottom flange at a 6% drift level was the final failure mode of specimen A. Specimen B failed through the fracture of the top splice plate of the bolted splice at a very high drift ratio of 8.0% radian.

Effects of Complex Probiotics and Antibiotics on Growth Performance and Meat Quality in Broilers (복합생균제와 항생제 급여가 육계의 생산성 및 육질에 미치는 영향)

  • Park, Sung-Hyun;Choi, Jung-Suk;Jung, Dong-Soon;Auh, Joong-Hyuck;Choi, Yang-Il
    • Food Science of Animal Resources
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    • v.30 no.3
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    • pp.504-511
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    • 2010
  • This study was undertaken to investigate the effects of feeding complex probiotics (Lactobacillus casei, Bacillus subtilis, Saccharomyces cerevisiae, Aspergillus oryzae, Streptomyces griseus, $1.5{\times}10^{10}$ CFU/kg) and antibiotics (oxytetracycline (OTC), 110 ppm) on growth performance and meat quality characteristics of broiler chicks. In the experiment 1, 0.3% complex probiotics feeding level was chosen to be proper addition level due to better average daily gain (ADG), feed conversion (FC) and dressing percent (DP) results among 3 levels (0.1, 0.3 or 0.5%). In the experiment 2, 5 treatments (T1, no probiotics + no antibiotics; T2, probiotics 0.3% + no antibiotics; T3, probiotics 0.3% + antibiotics 50%; T4, probiotics 0.3% + antibiotics 100%; T5, no probiotics + antibiotics 100%) were investigated. In the growth performance of broilers, T5 (antibiotics 100% only) showed the highest (p<0.05) ADG and FC values while T1 (control) showed the worst growth performance. However, T3 (probiotics 0.3% + antibiotics 50%) showed higher ADG (p<0.05), FC (p<0.05) and DP (p>0.05) values compared to control. In the breast and leg meat quality, T3 showed similar pH, proximate composition, cooking loss and meat color values except shear force value compared to T5. Addition of 0.3% probiotics with 50% antibiotics (T3) tended to lower the blood cholesterol levels of broiler chicks and Escherichia coli or Salmonella counts in cecum microflora of broiler chicks compared to T5. In the residual antibiotics analysis, T3 contained 0.04 ppm of residual antibiotics in the breast meat while T4 or T5 contained 0.1 ppm of residual antibiotics and addition of 0.3% probiotics with 50% antibiotics in broiler diets could lower the residual antibiotics level to 40% in the meat. As a result, 0.3% probiotics addition with 50% antibiotics in the broiler diets could be recommended for the production of high quality broiler meat.

Optimization of the Acetic Acid Fermentation Condition of Apple Juice (사과식초 제조를 위한 사과주스의 초산발효 최적화)

  • Kang, Bok-Hee;Shin, Eun-Jeong;Lee, Sang-Han;Lee, Dong-Sun;Hur, Sang-Sun;Shin, Kee-Sun;Kim, Seong-Ho;Son, Seok-Min;Lee, Jin-Man
    • Food Science and Preservation
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    • v.18 no.6
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    • pp.980-985
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    • 2011
  • This study was conducted to determine the acetic-acid fermentation properties of apple juice (initial alcohol content, apple juice concentration, acetic-acid content, and inoculum size) in flask scale. At the acetic-acid fermentation of apple juice with 3, 5, 7, and 9% initial alcohol content, the maximum acidity after 10-day fermentation was 5.88% when the initial alcohol content was 5%. The acetic-acid fermentation did not proceed normally when the initial alcohol content was 9%. When the initial Brix was $1^{\circ}$, the acidity gradually increased, and the acidity after 12-day acetic-acid fermentation was 4.48%. Above 4% acidity was attained faster when the apple juice concentration was 5 and 10 $^{\circ}Brix$ than when it was 1 and 14 $^{\circ}Brix$. When the initial acidity was 1% or above (0.3, 0.5, 1.0, and 2.0%), the acetic-acid fermentation proceeded normally. The acetic-acid fermentation also proceeded normally when the inoculum sizes were 10 and 15%, and the acidity after eight-day acetic-acid fermentation was 5.60 and 6.05%, respectively. Therefore, the following were considered the optimal acetic-acid fermentation conditions for apple cider vinegar: 5% initial alcohol content, 5 $^{\circ}Brix$ or above apple juice concentration, 1.0% or above initial acidity, and 10% or above inoculum size. Apple cider vinegar with above 5% acidity can be produced within 48 h under the following acetic-acid fermentation conditions: 7% initial alcohol content, about 1% initial acidity, and 10% inoculum volume at $30^{\circ}C$, 30 rpm, and 1.0 vvm, using 14 $^{\circ}Brix$ apple juice in a mini-jar fermentor as a pre-step for industrial-scale adaptation.

Research Trends in Hybrid Cross-Laminated Timber (CLT) to Enhance the Rolling Shear Strength of CLT (CLT의 rolling shear 향상을 위한 hybrid cross laminated timber 연구 동향)

  • YANG, Seung Min;LEE, Hwa Hyung;KANG, Seog Goo
    • Journal of the Korean Wood Science and Technology
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    • v.49 no.4
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    • pp.336-359
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    • 2021
  • In this study, hybrid CLT research and development trends were analyzed to improve the low rolling shear strength of CLT, a large wooden panel used in high-rise wooden buildings. Through this, basic data that can be used in research and development directions for localization of CLT were prepared. As a way to improve the low rolling shear strength, the use of hardwood lamina, the change of the lamina arrangement angle, and the use of structural composite materials are mainly used. Rolling shear strength and shear modulus of hardwood lamina are more than twice as high as softwood lamina. It confirmed that hardwoods can be used and unused species can be used. Rolling shear strength 1.5 times, shear modulus 8.3 times, bending stiffness 4.1 times improved according to the change of the layer arrangement angle, and the CLT strength was confirmed by reducing the layer arrangement angle. Structural wood-based materials have been improved by up to 1.35 times MOR, 1.5 times MOE, and 1.59 times rolling shear strength when used as laminas. Block shear strength between the layer materials was also secured by 7.0 N/mm2, which is the standard for block shear strength. Through the results of previous studies, it was confirmed that the strength performance was improved when a structural wood based materials having a flexural performance of MOE 7.0 GPa and MOR 40.0 MPa or more was used. This was determined based on the strength of layered materials in structural wood-based materials. The optimal method for improving rolling shear strength is judged to be the most advantageous application of structural wood based materials with strength values according to existing specifications. However, additional research is needed on the orientation of CLT lamina arrangement according to the fiber arrangement of structural wood-based materials, and the block shear strength between lamina materials.

Phase Behavior Study of Fatty Acid Potassium Cream Soaps (지방산 칼륨 Cream Soaps 의 상거동 연구)

  • Noh, Min Joo;Yeo, Hye Lim;Lee, Ji Hyun;Park, Myeong Sam;Lee, Jun Bae;Yoon, Moung Seok
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.48 no.1
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    • pp.55-64
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    • 2022
  • The potassium cream soap with fatty acid called cleaning foam has a crystal gel structure, and unlike an emulsion system, it is weak to shear stress and shows characteristics that are easily separated under high temperature storage conditions. The crystal gel structure of cleansing foams is significantly influenced by the nature and proportion of fatty acids, degree of neutralization, and the nature and proportion of polyols. In order to investigate the effect of these parameters on the crystal gel structure, a ternary system consisting of water/KOH/fatty acid was investigated in this study. The investigation of differential scanning calorimeter (DSC) revealed that the eutectic point was found at the ratio of myristic acid (MA) : stearic acid (SA) = 3 : 1 and ternary systems were the most stable at the eutectic point. However, the increase in fatty acid content had little effect on stability. On the basis of viscosity and polarized optical microscopy (POM) measurements, the optimum degree of neutralization was found to be about 75%. The system was stable when the melting point (Tm) of the ternary system was higher than the storage temperature and the crystal phase was transferred to lamellar gel phase, but the increase in fatty acid content had little effect on stability. The addition of polyols to the ternary system played an important role in changing the Tm and causing phase transition. The structure of the cleansing foams were confirmed through cryogenic scanning electron microscope (Cryo-SEM), small and wide angle X-ray scattering (SAXS and WAXS) analysis. Since butylene glycol (BG), propylene glycol (PG), and dipropylene glycol (DPG) lowered the Tm and hindered the lamellar gel formation, they were unsuitable for the formation of stable cleansing foam. In contrast, glycerin, PEG-400, and sorbitol increased the Tm, and facilitated the formation of lamellar gel phase, which led to a stable ternary system. Glycerin was found to be the most optimal agent to prepare a cleansing foam with enhanced stability.