• Elastomers and Composites
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• 제58권3호
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• pp.128-135
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• 2023

To improve the adhesive strength of natural rubber (NR) for a seismic isolation damper, citraconic acid-g-NR (CCA-g-NR) was synthesized via the melt grafting of citraconic acid (CCA) onto NR using an azobisisnomerobutyronitrile (AIBN) initiator. Subsequently, the influence of CCA and AIBN concentrations on the graft ratio G/R (%) and graft efficiency G/E (%) of the CCA-g-NR was investigated. The optimum CCA and AIBN concentrations required to achieve the desired G/R (3.49%) and G/E (49.8%) were found to be 7 phr and 0.13 phr, respectively. Additionally, we studied the influence of CCA-g-NR concentration on the mechanical properties (tensile strength, elongation at break, and modulus at 300%), adhesive strength, and cure characteristics of the rubber compound in the seismic isolation damper. As the concentration of CCA-g-NR increased, the elongation at break and adhesive strength of the compound increased, whereas its tensile strength and modulus at 300% decreased. Moreover, as the concentration increased, the maximum torque decreased and the scorch time was delayed to obtain an optimal vulcanization time.

• 한국균학회지
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• 제49권1호
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• pp.81-86
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• 2021

전남 여수 금오산의 청미래덩굴 잎과 경남 통영 한산도의 삼나무 침엽을 표면살균하여 내생균을 분리하였다. 분리된 균주는 internal transcribed spacer (ITS), large subunit rDNA (LSU), translation elongation factor 1-α DNA (TEF)의 염기서열을 이용한 계통분석 및 형태적 특성을 이용하여 동정하였다. 본 연구에서 Phyllosticta 속에 속하는 두 종의 국내 미기록종 내생균이 확인되었으며, 확인된 종은 Phyllosticta ericaum과 Phyllosticta philoprina이다. 두 종의 내생균 균주에 대해 형태적 특성 및 계통분석의 결과를 보고하고자 한다.

• 한국안전학회지
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• 제34권1호
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• pp.8-13
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• 2019

Weight and elongation changes of IV and HIV insulations were measured simultaneously at several given temperature of $80^{\circ}C$, $90^{\circ}C$ and $100^{\circ}C$. And the lifetime was predicted using the Arrhenius model. Based on the initial weight values, a 50% elongation reduction was seen at 6.96% for the IV insulation and 10.29% for the HIV insulation. The activation energy from the slope of the lifetime regression equation was calculated as 92.895 kJ/mol(0.9632 eV) for the IV insulation and 95.213 kJ/mol(0.9873 eV) for the HIV insulation. Also, the expected lifetime at the operating temperature of $30^{\circ}C$ to $90^{\circ}C$ is 2.02 to 94.32 years, and longer lifetime was predicted on HIV insulated wires than on IV insulated wires. As a result, it was found that the thermal characteristics of the HIV insulated wires were about 12.44% better than those of IV insulated wires under the same conditions of use.

• 대한가정학회지
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• 제29권2호
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• pp.47-53
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• 1991

A. niger H-18 and A. fumigatus E-29 wrer selected for their strong abilities to produce cellulase. The λd numerical values of the cotton fabrics inoculated with A. niger H-18 and A. fumigatus E-29 were 580 nm for the both strains of molds. By the growth of molds, lightness, original color scale, and grey scale of the fabrics gradually decreased while chroma increased. The minimum inhibitory concentrations of mold-proofing agents, such as Leperon WL, 8-hydroxyquinoline copper acetate, trimethylol melamine and dimethyl ethylene urea was 50 ppm. Glycoxale was not effective at the above mentioned concentration. Since Leperon WL, trimethylol melamine and dimethyl ethylene urea effectively inhibited the growth of A. niger H-18 and A. fumigatus E-29, tensile strength and elongation of the fabrics were not changed. however, cotton fabrics treated with glycoxale of the fabrics were not changed. However, cotton fabrics treated with glycoxale and inoculated with A. niger H-18 and A. fumigatus E-29 showed decreased in tensile strength by 31.1% and 33.9%, respectively.

• 패션비즈니스
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• 제14권2호
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• pp.57-72
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• 2010

The purposes of the research were to find out the clothing construction factors of the mechanical industry working clothes by analyzing the working clothes supplied to 5 subject companies; and to suggest the optimized sewing conditions and the seam strength and elongation experimental data according to the clothing material and seam types implied to the working clothes collected. The fabric types and trimmings used for the mechanical manufacturing working clothes were Polyester/Cotton(65/35%), Polyester/Rayon(65/35%), Cotton(100%); and linings, interlining, various fastenings etc. 2 stitch types, i.e. lock and two-thread chain stitches were applied to the construction of the flat, lap felled, French, superimposed, lapped and bound seams for the seam strength and elongation experiment. The results derived from the experiment were as follows. (1) The seam strength results according to the seam types were high in the order of lap felled>lapped>flat, superimposed and French seams. (2) Considering the features of the seam construction, as the number of fabric layers at the seam line increased the seam strength also increased. (3) Apart from the highest seam strength from the experiment using the net lining with the main fabric, the seam construction consisting of two fabric layers with the interlining showed relatively high seam strength results. (4) The seam elongations according to the stitch types were high in the order of two-thread chain>lock stitches.

• 감성과학
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• 제19권2호
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• pp.19-26
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• 2016

기존 연구들에서는 사람들이 길고 가는 원통형 용기의 부피를 짧고 넓은 원통형 용기의 부피보다 크다고 지각한다는 점을 밝혀왔다(예, Raghubir & Krishna, 1999; Wansink & Van Ittersum, 2003). 본 연구에서는 이러한 신장 효과가 상자형 용기에서는 반대로 나타나는 현상을 밝히었다. 가설은 상자형 용기의 행동 유도성으로부터 도출되었다. 두 개의 연구에서 참가자들은 짧고 넓은 사각 상자 용기의 부피가 길고 가는 사각 상자 용기의 부피보다 더 크다고 지각하였다. 이 효과는 자극의 제시 방법(그림, 연구 1; 실제 모형, 연구 2)이나 선택지 유형(둘 중 큰 것을 고르는 선택지, 연구 1; 둘 중 큰 것을 고르거나 같은 경우를 고르는 선택지, 연구 2)에 상관없이 일관되게 나타났다. 또한, 서로 다른 문화적 배경을 지닌 참가자 집단(미국인 참가자, 연구 1; 한국인 참가자, 연구 2)에서 동일한 효과가 나타났으며, 용기 안의 내용물이 물(연구 1)인 경우뿐만 아니라 전반적인 액체 음료(연구 2)라고 설정했을 때에도 같은 결과가 나타났다. 본 연구에 대한 이론적이고 실제적인 함의가 논의되었다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.228-233
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• 2004

The characteristics of the probability distribution for mechanical properties, e.g. tensile strength, reduction of area ana elongation, for STS304 stainless steel in elevated temperature were investigated from tensile test performed by constant cross head speea controls with 1mm/min, Recently, in order to clarify the strengthening mechanisms at high temperature, a new scheme to improve high temperature mechanical properties is desired. Therefore, the test ,technique development of high temperature creep behaviors for this material is very important. In this paper, the creep praperties and creep life prediction by Larson-Miller parameter method for STS304 stainless steel to be used for other high temperature components were presented at the elevated temperatures of 600, 650 and $700^{\circ}C$.

• 한국해양공학회지
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• 제18권2호
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• pp.64-69
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• 2004

The characteristics of the probability distribution for mechanical properties, e.g. tensile strength, reduction of area, and elongation, for STS304 stainless steel in elevated temperature are investigated. Tensile test is performed by constant crosshead speed controls with 1mm/min. The probability distribution function of measured mechanical properties seems to follow $\alpha$ 3-parameter Weibull, and shows a slight dependence on the temperature. When the temperature is raised, the shape parameter a is increased, but both the scale parameter $\beta$ and location parameter v are decreased.

• 대한가정학회지
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• 제25권4호
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• pp.1-8
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• 1987

The effects of Aspergillus niger H-18(AN) and A.fumigatus E-29(AF) on the deterioration of test materials were examined. 1. When the fungi were inoculated to the cotton fibers placed on Czapeck agar, malt extract agar, and potato agar, they grew best on potato agar which in that context was chosen as a basal medium for deterioration studies. The tensile strength of ontton fiber on which AN was grown for 30 days decreased by 33.9% with a concommitant increase in elongation by 43.1%. 2. Cotton fabric lost the weight by 1.35%, when inoculated with AN while it lost the weight by 0.86% when inoculated with AF. 3. When AN and AF were inoculated separately on cotton fibers, tensile strength decreased by 52.8% and 43.3%, respectively, with concommitant increases in elongation by 34.2% and 29.4%, respectively. 4. The cotton was damaged more severely by AN than AF, when they were observed by scanning electron microscope.

• 한국연초학회지
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• 제5권2호
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• pp.63-69
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• 1983

The tensile strength (Pm) . elongation percentage ($\varepsilon$) , elastic modulus (I) , and specific volume (Sv) were calculated from the data of tensile characteristics of By 104 .and Burley 21 tobacco leaves, which were measured over a relative humidity from 60 to 80% at $20\pm2^{\circ}C$.The important results obtained were as follows.(1) Tensile strength(Pm) The "Pm"of By 104 was greater than that of Burley at. The "Pm"in both varieties were increased toward the upper stalk position and according to the decrease of relative humidity. The "Pm" of parallel piece to tile vein in a leaf were greater than that of right angle piece to the vein. (2) Elongation percentage ($\varepsilon$). The "s" of By 104 was higher than that of Burley 21. The "s" in both varieties were increased toward the upper stalk position and according to the increase of relative humidity. The "s" of parallel Piece to the vein in a Burley leaf was greater than that of right angle piece to the vein. (3) Elastic modulus (E) The "E" of Burley 21 leaf was higher than that of By 104. The "E" in both varieties were increased toward the lower stalk position and according to decrease of relative humidity. The "E"of parallel piece to the vein in both varieties leaves were greater than that of right angle piece to tile vein. (4) Specific volume (Sv) The "Sv" of Burley 21 leaf was increased than that of By 104. The "Sv" in both varieties were increased toward the lower stalk position and according to the decrease of relative humidity.ot;Sv" in both varieties were increased toward the lower stalk position and according to the decrease of relative humidity.dity.