• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.6
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• pp.317-322
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• 2002

We have studied the sawing sach as the round brilliant cut, cushion barion cut and marquise cut. Through this study, we could examined the rate of waste from the grinding work, and find a solution for many problems which could be derived from the grinding work. We could reduce the rate of waste by this study about sawing technique; 2.5 % for round brilliant cut, 2.5 % for cushion barion cut and 5.5 % for marquise cut.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.473-481
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• 2006

Predicting fatigue life by numerical methods was almost impossible in the field of rubber materials. One of the reasons is that there is not obvious fracture criteria caused by nonstandardization of material and excessively various way of mixing process. But, tearing energy as fracture factor can be applied to a rubber-like material regardless of different types of fillers, relative to other fracture factors and the crack growth process of rubber could be considered as the whole fatigue failure process by the existence of potential defects in industrial rubber components. This characteristic of fatigue failure could make it possible to predict the fatigue life of rubber components in theoretical way. FESEM photographs of the surface of industrial rubber components were analyzed for verifying the existence and distribution of potential defects. For the prediction of fatigue life, theoretical way of evaluating tearing energy for the general shape of test-piece was proposed. Also, algebraic expression for the prediction of fatigue life was derived from the rough cut growth rate equation and verified by comparing with experimental fatigue lives of dumbbell fatigue specimen in various loading condition.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.741-747
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• 2006

It has been almost impossible to predict the fatigue life in the field of rubber materials by numerical methods. One of the reasons is that there are no obvious fracture criteria and excessively various ways of mixing processes. Tearing energy is considered as a fracture criterion which can be applied to rubber compounds regardless of different types of fillers, relative to other fracture factors. Fatigue life of rubber materials can be approximately predicted based on the assumption that the latent defect caused by contaminants or voids in the matrix, imperfectly dispersed compounding ingredients, mold lubricants and surface flaws always exists. Numerical expression for the prediction of fatigue life was derived from the rate of rough cut growth region and the formulated tearing energy equation. Endurance test data for dumbbell specimens were compared with the predicted fatigue life for verification. Also, fatigue life of industrial rubber components was predicted.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.143-154
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• 2016

The purpose of this study was investigated the quality changes before and after harvesting, storage and, processing of onion. Experiments were carried out to compare the effect on the characteristics of the postharvest from preharvest factors using onion. This experiment had identified the characteristics of harvested onions after cultivating with several preharvest factors such as the light and water conditions. These tests were conducted in an onion growth in the field, storage, and processing of fresh-cut during a laboratory periods of 2 years. In first year, onion cultivars ('Kars' and 'Pop') were produced under stable or unstable environment conditions, these onions were stored at low temperature(0?). Measurement was evaluated by the growth amount after harvesting, and the fresh weight loss and respiration rate during storage. According to different culture conditions and storage temperatures, it was investigated the properties of the fresh-cut onion. Growth of onion was varied depending on the cultivars and culture conditions. The amount of growth on 'Kars' and 'Pop' onions were decreased by excessive soil water conditions with shading. These influences were found the morphological differences resulting for the cell tissue of onion being rough and large. Onion cultivated in excessive soil water with shading affected the degree of its respiration rate and fresh weight loss during storage. Ones in excessive soil water with shading were higher than the control in fresh weight loss and respiration rate, respectively. However fresh-cut onion could not investigated to clarify the difference due to effects of cultivation condition and storage temperature on some measure items such as electrolyte leakage and microbial number change. There was a change of only electrolyte leakage depending on the storage temperature, rather than cultivated conditions before harvesting factor. The results showed that the onion grown on in the good environment was represented to a good quality produce even after harvesting.