• Composites Research
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• v.19 no.6
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• pp.16-22
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• 2006

The puncture properties under various conditions were investigated for the optimum conditions to yield the best properties. Fiber aspect ratio(AR: length of fiber/diameter of fiber), interphase condition and fiber content were considered as variables which impact the puncture force and friction force. The puncture force of short-fiber reinforced rubber increases up to 3.4 times compared to the virgin material. The better interphase condition shows the higher puncture force at given fiber AR and fiber content. The friction force of the matrix and reinforced rubber with a fiber AR below 155 does not exist. The friction force of the reinforced rubber with the good interphase condition and high fiber AR is higher than puncture force of matrix. Overall, it was found that the interphase condition, fiber AR and fiber content have an important effect on the puncture properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.173-178
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• 1991

The rheological properties of acorn crude starch gel and refined starch gel were investigated by puncture test, back-extrusion test and retrogradation test. Puncture test was a useful method to compare the different gel type and concentration, and to calculate the compression and shear coefficient. Maximum extrustion force and adhesiveness were also examined by performing back-extrustion test. The retrogradation rate was analysed by Avrami equation in retrogradation test.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.283-285
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• 1998

Although many papers have been published for the mechanical properties of nonwoven fabrics, there is no report on the relationship of tensile and puncture properties. For the further applications of lightweight nonwoven products like protective clothing materials, thorough understanding of the relationship should be preceded when they are subjective to puncture farce. [1,2] (omitted)

• Composites Research
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• v.20 no.6
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• pp.28-33
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• 2007

The puncture properties of short-fiber reinforced rubber were investigated as functions of fiber aspect ratio(AR: length of fiber/diameter of fiber), fiber content, specimen size and testing velocity. The puncture stresses of the matrix and short-fiber reinforced rubber decreased with specimen size, and increased with testing velocity at same specimen size. As the fiber AR increased the puncture stress at given fiber content also increased. The problem of the specimen shape was investigated by the comparison of the tensile strength with puncture stress. The forces acting in the membrane wall of the matrix and the short-fiber reinforced rubber showed a similar data regardless of specimen size. And those increased with testing velocity at same specimen size. As the fiber AR increased the force acting in the wall at given fiber content also increased. Overall, it was found that the specimen size, testing velocity had an important effects on the puncture properties.

• Korean journal of food and cookery science
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• v.11 no.1
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• pp.83-91
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• 1995

For the accurate interpretation and objective measurement of textural characteristics of fermented vegetables, first of all, the studies on the microstructure and chemical compositions of vegetable cell, and the changes in the textural properties of vegetables during salting, blanching and fermentation should be carried out. And the mechanical textural parameters were needed to compare with and analyze in relation to the sensory parameters. In this review, the thypical force-distance curves of fermented vegetables were obtained from the compression, cutting and puncture test. And it was showed that the compression force was a more effective textural parameter to express the hardness of fermented vegetables, and the sensory chewiness and toughness were related to the changes in cutting force. In the puncture test, the puncture force was related to the hardness and varied with the size and form of puncture probe; the changes in puncture force by small probe could express the decrease in hardness and crispness, whereas those by large probe could represent the changes in toughness. And the brittleness and crispness could be measured by the break point and the numbers of peak obtained from the force-distance curves.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.469-473
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• 1985

The typical force-distance curves by puncture test and Back Extrusion test of acorn flour gels were investigated. Kc' and Ks' were calculated to estimate the compression and shear components of a puncture force. In this study, compression effect played a major role. The more concentration of acorn flour gel and diameter of probe increased, the more compression force contributed to the puncture force. In the Back Extrusion test, the effect of increasing the sample size was to extend the length of the plateau without affecting the maximum force. However, as the concentration of acorn flour gel increased, maximum Extrusion force became larger.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.382-388
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• 2019

Objective : The primary aim of this investigation was to explore the nature of dura mater biomechanics following the introduction of puncture defect(s). Methods : Twenty-eight dura mater specimens were collected during autopsy from the department of forensic medicine of the authors' institution. Specimens were divided randomly into one of four groups : group I (cranial dura mater; n=7), group II (cranial dura mater with one puncture defect; n=7); group III (cranial dura mater with two puncture defects; n=7), and group IV (cranial dura mater with three puncture defects; n=7). Results : The mean${\pm}$standard deviation tensile strengths of the dura mater were $8.35{\pm}3.16$, $8.22{\pm}3.32$, $7.13{\pm}1.77$, and $6.94{\pm}1.93MPa$ for groups I, II, III, and IV, respectively. There was no statistical difference between all groups. A single, two or more punctures of the dura mater using a 20-gauge Quincke needle did not affect cranial dura tensile strength. Conclusion : This biomechanical study may contribute to the future development of artificial dura mater substitutes and medical needles that have a lower negative impact on the biomechanical properties of dura mater.

• Journal of the Korean Home Economics Association
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• v.26 no.3
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• pp.93-102
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• 1988

Rheological properties of cowpea and mung bean starch gels and pastes were investigated and compared with Instron Universal Testing machine and Brabender Viscometer. As the result of puncture test of gels, yield point force of mung bean starch gel was higher than that of cowpea starch gel. Compression coefficient of cowpea starch gel calculated by Bourne's equation was lower than that of mung bean starch gel. the stress relaxation test showed that viscoelastic properties of cowpea and mung bean starch gels may be represented by six element Maxwell model consisting of three Maxwell element in parallel. Cowpea and mung bean starch pastes showed bingham pseudoplastic behavior in 3, 5, 6, 7 and 8%. The consistency index in 7∼8% of cowpea starch paste were lower than those of mung bean starch paste. concentration dependence on consistency index and yield stress in mung bean starch were higher than those of cowpea starch. The yield stress of starch pastes was significantly correlated with yield point force by puncture test (r=0.996).

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.364-371
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• 1986

High-ester pectin was demethylated by the treatments of HCl alone and a combination of HCl and $NH_4OH$. The low-ester pectin prepared were analyzed for chemical composition and the pectin gels were evaluated for firmness by sag values and strength by puncture stress. Gels made from HCl demethylated sample showed brittle, weak and poor elastic characteristics while the $HCl-NH_4OH$ treated samples generally resulted in a smooth and elastic gels except those samples having very low content of ester group or acid amide group. Statistical analysis showed that significant correlations were found between sag values and ester content or molecular weight, and puncture stress and ester content, acid amide groups or molecular weight. The equations derived for sag, puncture stress and sag/puncture stress from chemical data could be useful for prediction of some of the physical properties of low-ester pectin gel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.3
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• pp.195-200
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• 1990

Effects of cooking time(5-30 min in a pressure cooker) and HTST air dehydratiion time(0-9min at 15$0^{\circ}C$) on physical properties of dried green peas(3% oisture content wet basis) were investigated by determining rehydration ratio rehydration curve browning reaction and puncture force, The rehydration ratio and curve of dried green peas were increased with increa-sing cooking time and HTST air dehydration time. Preheating of the green peas for 30 min in a pressure cooker or for 9 min of HTST air dehydration time prior to 6$0^{\circ}C$ air dehydration recovered a 87.3% of original moisture content of raw green peas in a boiling water for 5 min. The brownin greaction was gradually decreased up to 15 min of cooking time. Puncture pressure of rehydrated green peas treated in a boiling water for 5 min was decreased as the cooking time and HTST air dehydration time were increased and was highly correlated with rehydration (r=-0.956) The effects of cooking time and HTST air dehydration time on rehydration ratio browning reaction and puncture pressure were significantly different at the a=0.01 level except effect of HTST air dehydration time on browning reaction.