• Journal of Animal Science and Technology
• /
• 제60권9호
• /
• pp.22.1-22.7
• /
• 2018

Background: Cooking temperature and consequently doneness of beef muscles are most important for the palatability and consumer acceptability. Current study assessed the response of mechanical texture of Hanwoo muscles as a function of cooking temperature at different ageing days. Six muscles (Psoas major (PM), Longissimus thoracics (LT), Gluteus medius (GM), Semimembranosus (SM), Biceps femoris (BF) and Triceps brachii (TB)) were collected from each 10 Hanwoo steers. Warner-Bratzler WB-shear force (WBSF) and texture profile analysis (TPA) texture profiles were determined after 3 or 21 days of chiller, and randomly assigned to four groups; non-cooked, cooked at 55, 70 or $85^{\circ}C$. Results: Toughness of WBSF and TPA hardness of Hanwoo muscles were presence in the order of LT = PM = GM = SM < BF = TB (p < 0.001) for non-cooked raw muscle, and PM < LT = GM = SM < TB=BF (p < 0.001) for cooked meat aged for 3 days. WBSF linearly increased in 3 days aged meats after cooked at a higher temperature (P < 0.05). On the other hand, toughening of the muscles were significantly (P < 0.05) differed at various temperature when muscles were aged for 21 days. WBSF of PM and LT muscles were significantly increased at a higher cooking temperature, while other muscles (i.e., GM, SM, BF, TB) showed the lowest values at $70^{\circ}C$. In the case of TPA hardness, the effect of cooking temperature was very less in the toughness of the muscle (P > 0.05). Conclusion: Taken together, these findings clearly showed that the toughness of the muscle highly depends and varies upon the temperature and ageing of the muscle. Moreover, the effect of cooking temperature was very limited on aged muscles. The results mirror the importance of cooking temperature for objective measurements which ultimately estimate sensory tenderness and other quality traits.

• 동력기계공학회지
• /
• 제12권2호
• /
• pp.48-54
• /
• 2008

Underwater wet arc welds of rolled steel plate (SM41) where studied welding and mechanical properties macro and narrow than that of the other things. Tensile strength of UWEB obtained to 521.5 MPa and of USBL was 524.1 MPa, but the highest elongation value was 4.68 %(UWEB). Bending strength(1166.6 MPa) of USBL is the largest and of UWEB in 1047 MPa, But deflection(22.73 mm) of UWEB in large than that of USBL(22.63 mm). Impact value(144.36 $J/cm^2$) of JPUW is the largest and of UWEB(140 $J/cm^2$) come after.

• 한국양식학회지
• /
• 제21권4호
• /
• pp.259-264
• /
• 2008

한국산 누치속(genus Hemibarbus) 어류 3종에 대한 세포유전학적 특성을 구령하기 일해 적혈구 세포 크기, 세포당 DNA 함량 및 염색체 핵형을 분석하였다. 누치 H. labeo, 참마자 H. longirostris 및 어름치 H. mylodon의 적혈구 크기를 비교한 결과, 적혈구 세포 장경, 세포 표면적 및 세포 체적에서 어름치가 다른 2종보다 크게 나타났다(P<0.05). 그러나 DNA 함량은 적혈구 세포 크기와 다른 경향을 보여 2.33-2.51 범위로 3종간에 유의적인 차이를 보이지는 않았다(P>0.05). 누치속 어류 3종의 염색체 수는 모두 2n=50개로 나타났으나 핵형에 있어서는 종별로 서로 달라 누치 16M+16SM+18T,A (Fundamental number: NF, 82), 참마자 18M+16SM+16T,A (NF, 84) 그리고 어름치가 18M+24SM+8T,A (NF, 92)로 나타나 3종은 핵형에서 뚜렷한 차이를 보였다.

• 한국의류학회지
• /
• 제22권2호
• /
• pp.267-278
• /
• 1998

The purpose of this study was to investigate the degree of self-monitoring (SM), the task situation and the appeal type of advertising impact on consumer behavior: in inner wear purchase. Information for the study was obtained with the use of experimental design. the experimental materials for the study were two-type inner wear advertisements (image appeal Ad/product appeal Ad). The subjects were 270, who were randomly sampled women undergraduate students in Korea, and main-test subjects (70 high SM subjects/69 low SM subjects) were assigned to the cells of 2 (self usage/gift-giving)x2 (quality appeal Ad/image appeal Ad). According to the 2x(2$\times$2) mixed factorial design, the level of SM score, the type of task situation score and the level of appeal type of advertising score were compared and tested by analysis of ANOVA. The results of experiment were as follows: 1. Experimental 1. the results showed the product preference on inner wear was the significant 3-way interaction effects among the degree of SM, the task situation, and the appeal type of advertising as well as the significant main effects of the appeal type of advertising. That is, the situation impact differs from the appeal type of advertising according to the degree of SM. 2. Experimental ll. the results showed the purchase intention on inner wear was the significant 2-way interaction effects between the appeal type of advertising and the task situation as well as the significant main effects of the appeal type of advertising and the task situation. That is, there is considerable difference in gift-giving situation rather than in self- usage situation according to the appeal type of advertising.

• 한국해양공학회지
• /
• 제32권6호
• /
• pp.502-510
• /
• 2018

In order to accumulate data to lower the friction coefficient of a press mold, tribological tests were performed before and after coating SM45C with a PVC/PO film and plasma coating (CrN, concept). The ultrasonic nanocrystal surface modification (UNSM)-treated material had a nano-size surface texture, high surface hardness, and large and deep compressive residual stress formation. Even when the load was doubled, the small amount of abrasion, small weight of the abrasion, and width and depth of the abrasion did not increase as much as those of untreated materials. A comparison of the weight change before and after the tribological test with the CrN and the concept coating material and that of the untreated material showed that the wear loss of the concept coating material and P-UNSM treated material (that is, the UNSM treated material treated with the concept coating) showed a tendency to decrease by approximately 55-75%. Concept 100N had a lower friction coefficient of about 0.6, and P-UNSM-30-100N showed almost the same curve as concept 100N and had a low coefficient of friction of about 0.6. The concept multilayer coating had a thickness of $5.32{\mu}m$. In the beginning, the coefficient of friction decreased because of the plasma coating, but it started to increase from about 250-300 s. After about 350 s, the coefficient of friction tended to approach the friction coefficient of the SM45C base metal. The SGV-280F film-attached test specimen was slightly pushed back and forth, but the SM45C base material was not exposed due to abrasion. The friction coefficient was 0.22, which was the lowest, and the tribological property was the best in this study.

• 한국해양공학회지
• /
• 제2권2호
• /
• pp.112-121
• /
• 1988

A study on friction welding of carbon steel bar (SM45C) to chrome molybedenum steel bar(SCM4) is examined experimentally through tensile test, hardness test, microstructure test and fatigue test. so, this paper deals with optimizing the welding concitions and analyzing various mechanical properties about friction welds of SM45C to SCM4 steel bars. The results obtained are summarized as follows; 1) For friction welded joints of SM45C to SCM4 steel bars, the total upset(U)increases linearly with an increase of heating time ($t_{1}$) till 6s. 2) The determined optimum welding conditions are heating time ($t_{1}$)2s, upsetting time($t_{2}$), 3s, heating pressure($p_{1}$), 4kgf/$mm^{2}$(39.2MPa), upsetting pressure($p_{2}$, 8kgf/mm$^{2}$(78.4MPa) and rotating speed(N), 2, 000rpm when the total upset(U) is 3.4mm, resulting in a computed relationship between the joint tensile strength .sigma.$_{t}$ (kgf/mm$^{2}$and the total upset U(mm); .sigma.$_{t}$ =$0.21U^{3}$ - $3.38U^{2}$ +17.03U + 66.00 3) As the elongation is increased more and more, the fracture position becomes away from weld interface and the fractures are similar to those of SM45C. Fracture is taken place on SM45C side. 4) The weld interface of two dissimilar materials is mixed strongly, and the heat affected zone is about 2.0mm at SM45C while about 2.7 mm at SCM4 side. Therefore, the welded zone and heat affected zone are very narrow, comparing with those of the joints welded by the other welding methods. 5) The fatigue strengths at N=10$^{6}$ cycles of SM45C, SCM4 and friction welded joints are 23kgf/$mm^{2}$, 33kgf/$mm^{2}$(220.5 MPa), and 22.5kgf/$mm^{2}$(220.5MPa) respectively, and fracture at friction welded joint takes place at the side of SM45C. 6) The hardness of the friction weld interface is 3 times higher than that of base metal. 7) Fatigue strength of friction welded joint is higher than that of base metal. 8) Notch sensitivity factor of friction welded joint is lower than that of base metal.

• 분석과학
• /
• 제22권5호
• /
• pp.415-421
• /
• 2009

열 이온화 질량분석기를 이용한 가돌리늄 동위원소 비 측정에서 동중원소 영향에 대하여 실험했다. 특히 $^{155}Gd/^{158}Gd$ 측정값은 자연 동위원소 비 보다 높게 측정될 뿐만 아니라 시간에 따라 이 비가 감소하는 현상을 보였다. 이것은 Gd 시료 중 미량의 La 불순물이 산화상태($^{139}La^{16}O^+$, m/z=155)로 존재하여 $^{155}Gd$ 동위원소에 동중원소 영향을 미쳐 이의 측정값이 높게 나오는 현상으로 판단된다. 또한 Gd 보다 La이 용융점과 이온화 에너지가 낮기 때문에 초기에 $LaO^+$가 많이 생성되고 시간에 따라 소멸되므로 $^{155}Gd/^{158}Gd$ 값이 감소하는 것으로 생각된다. 레늄필라멘트 중 Gd 동위원소에 영향을 주는 불순물로 Ba ($BaO^+$), Ce ($CeO^+$), Sm ($SmO^+$), La ($LaO^+$) 그리고 $K_4{^+}$ (m/z=156) 클러스터 등이 있는 것으로 확인되었으나, 이러한 원소들은 필라멘트를 진공 가열시켜 줌으로 동중원소 영향을 없앨 수 있었다. 또한 La, Ce, Ba 등에 의한 동중원소 영향이 매우 크기 때문에 이런 시료는 Yb, Sm, Dy, Er, Lu 등의 방해원소가 없거나 극히 작다면 $Gd^+$ 금속이온을 직접 측정하는 것 보다 산화상태인 $GdO^+$ 이온으로 동위원소 비를 측정하고 산소 동위원소 비를 보정해 주는 방법을 사용함으로 동중원소 영향을 피할 수 있는 방법임을 알 수 있었다.

• 대한미생물학회지
• /
• 제14권1호
• /
• pp.49-61
• /
• 1979

Two hundred and ninety-five strains of Peudomonas aeruginosa isolated from clinical sources were tested for drug resistance and demonstration of R plasmids by intraspecies conjugation system. Sixty strains were found highly resistant to two or more of drugs. The rate of resistant strains were 38.9% to kanamycin(km), 33.2% to streptomydn(sm), 22.7% to sulfisomidine(Sa), 14.2% to chloramphenicol(Cp), 13.8% to tetracycline(Tc), 3.0% to carbenicillin(Cb), and to gentamicin(Gm), respectively. But no strains was resistant to nalidixic acid and colistine. They were resistant to per milliliter to more than $400{\mu}g$ per ml. of Tc, $800{\mu}g$ per ml of Cp and of Sm, $6,400{\mu}g$ per ml. of Sa, $200{\mu}g$ per ml. of Cb, $100{\mu}g$ per ml. of Gm, and $25{\mu}g$ per ml. of colistine. Forty-three strains of Pseudomonas aeruginosa could be transferred their resistance to Pseudomonas aeruginosa 2-70, 1005 rifampin resistant FP-auxotrophic mutant. Of sixty multiple resistant strains, forty-three(71.6%) demonstrated R plasmids; nineteen carried resistance to(Tc Cp Sm Sa), six to(Tc Cp Sm), three to(Tc Cp Sa), and Cp, five to(Tc Sm Sa), two to(Tc Sa), (Cp Sm) and Tc, and one to(Cp Sm Sa). Degree of resistance of recipients recieving R plasmids from donors were almost the same level of resistance as the donor in regardless of mating temperature at $25^{\circ}C$ and $37^{\circ}C$. Resistance to Tc, Sm, and Sa were transferred to a very few of recipient cells at five minutes after mating with donor and recipient cells but resistance to Cp were transferred to the majority of recipient cells. The transfer frequency of Tc, Cp, Sm, and Sa resistance from donors to recipients were from $1.0^{-1.4}\;to\;1.0^{-3.5}$ at $25^{\circ}C$ for 18 hours of incubation and were from $1.0^{-1.5}\;to\;1.0^{-3.5}$ at $37^{\circ}C$ for 18 hours of incubation.

• 대한기계학회논문집
• /
• 제11권5호
• /
• pp.762-771
• /
• 1987

본 연구에서는 국산 구조용 강인 SM45C와 SUS304재를 마찰가열압력과 업셋압 력을 서로 변화시키고 업셋시간을 2초로 고정하여 압접시간 10초를 기준으로 하여 변 화시키면서 마찰압접한 후 압접시간 변화에 따른 인장강도의 변화와 업셋량 변화에 따 른 인장강도 및 굽힘강도를 고찰하였다.또 최고 강도치를 나타내는 압접조건을 구 한 후 미소 경도치 및 이종재의 압접부에서 미소하게 변화하는 조직변화도 함께 고찰 하였다.

• 한국산학기술학회논문지
• /
• 제22권4호
• /
• pp.554-562
• /
• 2021

본 연구는 김치로부터 β-glucosidase 생산하는 Lactobacillus plantarum SM4를 분리하여 흰 민들레 발효를 수행하고 미백과 주름개선 효과를 가지는 생리활성 평가를 위해 총 폴리페놀 함량, 플라보노이드 함량, 항산화 활성, 타이로시네이즈 활성저해, 콜라게네이즈 활성저해, 자외선 차단율을 분석하였다. 흰 민들레 발효물의 총 폴리페놀 함량이 41.8±0.26 mg GAE/g DW로 열수추출물 21.4±0.67 mg GAE/g DW에 비해 2배 가량 증가하였으며 항산화 활성은 65.6±4.7%로 4배 증가하였다. 미백과 주름개선의 지표인 타이로시나아제 및 콜라게네이즈 활성저해에 있어 흰 민들레 발효물이 87.9±4.73%와 66.7±3.48%로 열수추출물에 비해 각각 2.4배와 1.5배 증가한 결과를 보였다. 흰 민들레 발효물과 열수추출물의 자외선 차단 효과를 비교하였을 때, UVA(320 nm) 차단율이 각각 64.7%와 15.2%로 측정되어 흰 민들레 발효물이 열수추출물에 비해 더 높은 효과를 나타내어 김치로부터 분리한 L. plantarum SM4가 생산하는 β-glucosidase를 발효를 통해 피부 미백, 주름 방지, 자외선 차단 효과가 증진됨을 확인하였다.