• 한국식품과학회지
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• 제29권2호
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• pp.273-278
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• 1997

몇가지 채소류(오이, 무우, 마늘, 생강 및 감자)의 펀치특성을 살펴보기 위하여 식품물성 측정기로 일정하게 힘을 가하면서 힘-거리-시간 간의 관계를 살펴보고 성분함량 및 세포특성과의 관계를 살펴본 결과는 다음과 같다. 힘-거리 및 거리-시간 곡선 상에는 많은 변곡점 및 파괴점이 관찰되었으며, 이는 시료의 구성세포가 가해진 힘에 대해 저항 또는 항복할때 나타나는 현상으로 탐침속도가 느릴때 크고 분명하였다. 파괴점까지 힘-시간 및 거리-시간에 대한 회귀분석 결과 상관계수는 0.95이상이었다. 탐침이 시료를 관통하는 시간과 그때의 힘은 생강이 5.63초 및 4.88 N으로 컸고 오이가 4.15초 및 2.00 N으로 작았으며, 탐침속도가 빠를 수록 더 많은 파괴힘을 필요로 하였다. 상관관계 분석결과 세포가 클수록 수분함량이 많고 파괴거리가 커지며, 세포의 규칙성, 시료의 즙액, 조밀도와 힘-시간 간의 기울기는 작아지는 관계를 보였다. 비중이 클수록 파괴힘, 거리 및 시간은 작아졌으며, 거리-시간곡선의 기울기는 힘-시간곡선의 기울기와 반비례 관계가 있었다.

• Journal of Biosystems Engineering
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• 제14권3호
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• pp.207-214
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• 1989

In this study, impact force and angular displacement of the pendulum were measured by the load cell and potentiometer. Mechanical behavior of rough rice under impact loading was able to analyze precisely and efficiently, because measured data were accumulated and handled by the automatic data acquisition system making use of microcomputer system. Impact force and angular displacement were measured with a resolutiln of 1/1500 seconds in time. Mechanical behavior such as force and energy at rupture point of Japonica type and Indica type rough rice were measured with this system. After impact loading, the damage of rough rice was examined with the microphotograph and an allowable impact force was measured. The results obtained in this study are summarized as follows. 1. Machanical behavior of rough rice under impact loading was analyzed precisely and efficiently because measured data were accumulated and handled by this data acquisition system. 2. Rupture force and rupture energy of rough rice were appeared to be the lowest value in the range of 16 to 18 % moisture content, and rupture force and rupture energy of Japonica type were higher than those of Indica type in each level of moisture content. 3. From the result of the damage examined after the impact loading, allowable impact force was the lowest in the range of 16 to 18 % moisture content, and the value of the allowable impact force of Japonica type was higher than that of Indica type in each level of moisture content.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.416-421
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• 2004

Off-line feedrate scheduling is presented as the advanced technology to regulate cutting forces at the desired level through change of feedrates. In rough cutting, the feedrate scheduling aims at reducing the machining time, which is the most important factor for better productivity. Thus, the largest force which can avoid breakage of tool shank and tooth is a reference force for feedrate scheduling in rough cutting. In this paper, a calculation method of the reference cutting force for feedrate scheduling is developed. This model calculates rupture plane of tooth using the FEM analysis of a tool and computes the reference force using the transverse rupture strength of a tool. Experiments validate that the presented feedrate scheduling model reduced machining time drastically and regulate cutting forces at the reference cutting force.

• 대한화학회지
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• 제59권2호
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• pp.132-135
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• 2015

Bonding force and stiffness in amine-linked single-molecule junctions for Ag electrodes were measured using a home-built conducting atomic force microscope under ambient conditions at room temperature. For comparison, Au electrodes were used to measure the rupture force and stiffness of the molecular junctions. The traces of the force along with the conductance showed a characteristic saw-tooth pattern owing to the breaking of the metal atomic contacts or the metal-molecule- metal junctions. We found the rupture force and stiffness for Ag are smaller than those for Au electrodes. Furthermore, we observed that the force required to break the amine-Ag bond in the conjugated molecule, 1,4-benzenediamine, is smaller than in 1,4-butanediamine which is fully saturated. These results consist with the previous theoretical calculations for the binding energies of the nitrogen bonded to Ag or Au atoms.

• Journal of Biosystems Engineering
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• 제23권5호
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• pp.473-480
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• 1998

This study was performed to analyze the variation of various physicochemical factors related to the freshness of apple and tomato during post-harvest period. The total soluble solids content, uronic acid content, cell surface roughness. density, rupture deformation and rupture force were measured for 39 days at 7-day intervals for apple and for 11 days at 2-day intervals for tomato. respectively. The cell surface roughness of apple increased with the elapsed time, while the rupture force decreased. In case of tomato, uronic acid content, density and rupture deformation increased with the elapsed time whereas the rupture force decreased. Both apple and tomato exhibited the significant correlations among those physicochemical factors.

• Geomechanics and Engineering
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• 제9권4호
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• pp.427-445
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• 2015

By means of finite element numerical simulation and pseudo-static method, the shallow-buried bilateral bias twin-tube tunnel subject to horizontal and vertical seismic forces are researched. The research includes rupture angles, the failure mode of the tunnel and the distribution of surrounding rock relaxation pressure. And the analytical solution for surrounding rock relaxation pressure is derived. For such tunnels, their surrounding rock has sliding rupture planes that generally follow a "W" shape. The failure area is determined by the rupture angles. Research shows that for shallow-buried bilateral bias twin-tube tunnel under the action of seismic force, the load effect on the tunnel structure shall be studied based on the relaxation pressure induced by surrounding rock failure. The rupture angles between the left tube and the right tube are independent of the surface slope. For tunnels with surrounding rock of Grade IV, V and VI, which is of poor quality, the recommended reinforcement range for the rupture angles is provided when the seismic fortification intensity is VI, VII, VIII and IX respectively. This study is expected to provide theoretical support regarding the ground reinforcement range for the shallow-buried bilateral bias twin-tube tunnel under seismic force.

• 한국식품영양학회지
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• 제9권4호
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• pp.466-471
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• 1996

오이, 마늘, 생강, 감자 및 무의 압축특성을 규명하기 위하여 식품물성 측정기로 압축 힘, 거리 및 시간을 측정하고 이들의 상관관계를 살펴보았다. 힘-거리 및 거리-시간 곡선은 비교적 간단한 형태를 나타냈고 변곡점들이 잘 나타나지 않았다. 파괴점까지의 시간은 감자가 압축속도 60mm/min에서 11.79, 압축속도 120mm/min에서 6.16초로 가장 길었다. 마늘은 각각 9.65 및 4.55초로 적게 소요되었는데 이는 시료의 압축강도에 따른 차이 때문으로 생각된다. 파괴힘은 무와 감자는 압축속도별로 16.64∼20.00N으로 가장 컸으며, 파괴시에 시료는 탐침 밑에 뭉개어지는 거동을 보였다. 압축시험시 파괴점까지의 힘-시간과 거리-시간에 대한 회귀분석 결과 상관계수 값이 0.96이상이었으며, 시료간의 차이는 작았다. 힘-시간 곡선의 기울기는 오이와 마늘이 1.772∼3.385로 가장 켰으며, 감자가 각각 1.743 및 3.338로 작았으며, 거리-시간 곡선의 기울기와는 반비례 관계를 나타냈다.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.897-900
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• 2012

We examined theory for force-induced unbinding on a two-dimensional free energy surface where the internal dynamics of biomolecules is coupled with the rupture process under constant tension f. We show that only if the transition state ensemble is narrow and activation barrier is high, the f-dependent rupture rate in the 2D potential surface can faithfully be described using an effective 1D energy profile.

• Journal of Biosystems Engineering
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• 제30권5호
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• pp.280-284
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• 2005

Front the production on the farm to the consumer, agricultural products are subject to various physical treatments involving mechanical techniques and devices. It is essential to understand the physical laws governing the response of these biological materials so that the machines, processes, and handling operations can be designed fur maximum efficiency and the highest quality of the end products. A compression test system was developed to test the physical properties of fruits including apple, pear, and peach which may lead to a better understanding of the physical laws. The test system consisted of a digital storage oscilloscope and simple mechanism which can apply quasi-static compression to fresh fruits. Rupture force, energy, and deformation were measured at the five levels of compression speed from 1.25 to 62.5 mm/min for each internal and external tissues. Rupture forces for apple and pear were in the range of 42.2 to 46.2 N and 38.8 to 41.2 N for external and infernal tissues, respectively. Rupture forces fir peach external tissues were in the range of 48.2 to 54.0 N.

• Journal of Biosystems Engineering
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• 제30권5호
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• pp.274-279
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• 2005

Impact is one of the major cause of damage to fruits druing varios processes from the production on the farm to the consumer. The tissue of fruits are ruptured in a very short period time less than 10ms by impact loading. Mechanical behavior of fruits under impact loading can be analyzed better with high speed sampling data acquisition system and one of them is a digital storage oscilloscope. A impact test system was developed to test the physical properties of fruits including apple, pear, and peach which may lead to a better understanding of the physical laws. The test system consisted of a digital storage oscilloscope and simple mechanism which can apply impact force to fresh produce. Rupture force, energy, and deffrmation were measured at the five levels of drop heights from 4 to 24cm fur each internal and external tissues. Rupture forces for apple and pear were in the range of 72.9 to 87.7 N and 70.8 to 84.1 N for external and internal tissues, respectively. Rupture forces far peach external tissues were in the range of 43.4 to 65.0 N.