• Journal of Industrial Technology
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• v.7
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• pp.9-14
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• 1987

The maximum specific gravity of asphaltic concrete can be calculated based on the effective specific gravity of aggregates and the specific gravity of asphalt cement. The maximum specific gravity is sometimes obtained based on the apparent specific gravity of aggregates and specific gravity of asphalt concrete. However, the apparent specific gravity is in general greater than the effective specific gravity for most aggregates. This study showed, by comparing the results obtained based on two specific gravities, that application of the apparent specific gravity instead of the effective specific gravity resulted in discrepancies in the calculated values of effective asphalt content, air void and maximum density.

• Korean journal of food and cookery science
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• v.15 no.4
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• pp.377-381
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• 1999

This study was designed to observe the effect of the amount of egg and the specific gravity on the quality of sponge cake. There was a little difference of the moisture content by the specific gravity when the amount of egg was same. However, as the amount of egg was increased at the same specific gravity, the moisture content and baking loss was significantly increased(p<0.05). At 100% of egg amount, the largest specific loaf volume was gained at 0.55 of specific gravity, in the same way 150% at 0.45, 200% at 0.35, 250% at 0.45, The hardness of sponge cake was increased as the specific gravity was increased at the same amount of egg(p<0.05). The specific gravity which the lowest hardness was gained was 0.55 with 100% of the amount of egg, in th same way 0.45 with 150%, 0.35 with 200%. As the period of storage was longer, the increase of hardness was increased as the specific gravity went up at the same amount of egg(p<0.05). Therefore, in the case of sugar content 166%, the specific gravity with maximum specific loaf volume and minimum hardness was gained 0.55 at the amount of egg 100%, 0.45 at 150%, 0.35 at 200% and 0.35 at 250%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.434-439
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• 2008

The amount of salt to make seed sorting solution of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18 L water, which is lower amount than currently used. Five rice cultivars were examined. Percent germination and seedling emergence were not similar. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. However, if seeds with low speicific gravity are produced due to the bad grain filling condition and consequently total seed content of low specific gravity increases, results will be differnt. Reduction in total growth and yield could occur. It will be important to comply with the seed sorting criterion of 1.13 for Japonica, 1.06 for Tongil, and 1.04 for waxy rice variety to ensure the maximum rice growth and yield.

• Ocean and Polar Research
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• v.39 no.4
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• pp.257-267
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• 2017

Although Pacific mackerel (Scomber japonicus) is an important commercial species in Korea, its recruitment mechanism remains largely unknown. Diel vertical positioning of larvae in the water column, which is affected by their specific gravity and the surrounding water density, may help to provide an understanding on recruitment success through predator avoidance and prey availability. The specific gravity measurement on Pacific mackerel eggs and larvae would seem to be essential information necessary to learn about the transport process from spawning to nursery grounds, and consequently the recruitment success. Eggs were artificially fertilized, and larvae were fed with rotifer when their mouths opened 3-4 days after hatching. We conducted the experiment using a density gradient water column to measure the ontogenetic changes in specific gravity from fertilization to 10 days after hatching. Egg specific gravity was stable during most of the embryonic period, but a sudden increase to $1.0249g\;cm^{-3}$ happened just before hatching. However, the specific gravity of newly hatched larvae was much lighter ($1.0195g\;cm^{-3}$), and specific gravity tended to increase continuously after hatching. Comparison of specific gravity with seawater density reveals that eggs and newly hatched larvae can float in the surface layer of the ocean. For the later period of the experiment, the specific gravity showed a cyclic diel pattern: the highest in the evening while the lowest at dawn. The fullness of larval stomach may be responsible for the observed differences in specific gravity, because stomach fullness was lower (40-60%) at midnight, and higher (80-85%) in evening. The diel pattern of specific gravity might provide clues regarding how larvae match the diel vertical migration of prey organisms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.332-337
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• 2018

The Pacific cod Gadus macrocepahlus, lays demersal eggs and the hatching larvae rise toward the surface layer of the ocean to feed. The change in the specific gravity of eggs and larvae was investigated to examine their vertical distribution and movement in the water column. The specific gravities of fertilized eggs and various size classes of larvae were measured using a density gradient apparatus. In total, the instantaneous specific gravity of 146 eggs and 225 larvae were measured. To prevent any disturbance in the gradient water column due to larval movement, 0.004% MS222 was used for anesthesia. Due to their high specific gravity, eggs spawned were deposited over the sea-bed of the spawning ground. The specific gravity of hatching larvae decreased abruptly. However, Pacific cod larvae still had a comparatively high specific gravity at hatching ($1.03655{\pm}0.00146g/cm3$, n=4, mean SL=3.62 mm) and their specific gravities tended to decrease as they grew. The specific gravity stabilized 6 days after hatching ($1.02590{\pm}0.00212g/cm3$, n=15, mean SL=4.67 mm) and the cod larvae were eventually able to float in the water column.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.1-9
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• 2006

The structural wooden members of the ancient building are deteriorated by fungi and termite over time. The deteriorate of the members causes the decrease of the specific gravity and the strength of it, so the stability of the building is threatened. Therefore, in this study, the evaluation of the specific gravity, which is correlated with the strength of the wood, was conducted in the post member using Nondestructive Evaluation (NDE) - Drilling Resistance Test (DRT). For the purpose of it, the specific gravity and drilling resistance of small specimens was measured to obtain the correlation between the specific gravity and the drilling resistance. And then, the drilling resistance test of the post members, which were expected to have the deteriorated parts, was performed. Consequently, the correlation between the specific gravity and the drilling resistance was very high ($R^2=0.89$) and the distributions of the specific gravity were evaluated for the each member. Also, the results were verified by the visual inspection of the cross section of it. Especially, the various variations of the wood member such as the deteriorated parts with termite or fungi and the crack could be detected exactly but the knot couldn't because the drill could pass by or could not penetrate the knot.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.6-9
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• 1978

This experiment was attempted to investigate the effect of the specific gravity of silkworm eggs on the hatching and the practical hatching ratio depend upon six egg production companies for two silkworm races and their reciprocal crosses. 1. The hatching and the practical hatching ratio in the specific gravity of medium and heavy eggs were higher than in the specific gravity of light eggs. 2. Compare with Japanese or Chinese mother races each other, it was inclined that the former seems to be higher than the latter on the hatching ratio in the specific gravity of light and medium eggs, but the practical hatching ratio was high only in the specific gravity of light eggs. 3. Chinese mother races were different in the practical and the hatching ratio between the specific gravity of eggs. On the contrary in case of Japanese mother races were no difference for the hatching ratio but difference in the practical hatching ratio between the specific gravity of eggs. 4. On the egg production company, in case of the specific gravity of medium and light eggs, the hatching and the practical hatching ratio were high significance, but no difference in the specific gravity of heavy eggs.

• Journal of the Korea Furniture Society
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• v.10 no.1
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• pp.57-63
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• 1999

This study was carried out to analyze the relationship between basic physical properties and acoustical characteristics of imported violin wood and to offer the information on raw material procurement and incoming-material quality control to domestic violin makers which have purchased most raw materials from European exporting countries at high expense. Equilibrium moisture content of European spruce with lower specific gravity after the prolonged storage was rather higher than that of European maple with higher specific gravity. The specific gravity of spruce increased with decreasing annual ring width, however, that of narrower annual ring. Increasement in specific gravity enhanced the dynamic Young's modulus of both wood species, but influenced the vibration energy loss by internal friction differently between two species. For dynamic MOE, qurater-sawn spruce was higher than the flat-sawn, but maple showed the reverse directional characteristics. Consequently, it would be well for violin makers to establish the standard for materials and quality control system to assure the quality of their violin products.

• KSBB Journal
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• v.22 no.5
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• pp.366-369
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• 2007

In this study, the feasibility of reusing the eluent was confirmed by monitoring its specific gravity during the chromatographic purification of paclitaxel from plant cell cultures. The specific gravity of the eluent (methanol/water = 70/30, v/v) was measured prior to its elution through the hydrophobic resin column. The measurement showed a specific gravity of 0.853. The discharged eluent from the column outlet was first evaporated under vacuum pressure. The evaporated eluent was collected and condensed into a liquid eluent again, followed by the HPLC analysis in order to check the presence of any trace of impurity. Even if the specific gravity of the liquid eluent is varied from 0.853 as a result of the evaporation and condensation, the eluent can still be reused after it specific gravity is adjusted by the addition of methanol or water. The reuse of the eluent resulted in the paclitaxel yield of 86% with a purity of 95% which were closely similar to those of before the eluent reuse. These results indicate that the strategy of reusing the eluent on the basis of the specific gravity analysis was successfully implemented in this study.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.458-471
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• 2020

Effect of pre-treatment and compression ratio on specific gravity (SG) and dimensional stability improvement of three lesser-used wood species from natural forest area of North Kalimantan Province, Indonesia had been investigated. Hot soaking at 80℃ for 3 hours within 2 and 5% of boron solution was applied as pre-treatment, while compression ratio applied was 20 and 40% from the initial thickness. Densification was conducted using hot pressing machine at 30 kg/㎠ of pressure and 160℃ of temperature for 15 minutes. Specific gravity was measured gravimetrically, while dimensional stability was evaluated through thickness swelling and water absorption as the indicator. Results show that SG of densified wood was influenced by wood species and compression ratio, but not by pre-treatment applied; while dimensional stability was influenced by wood species, compression ratio, and pre-treatment. Specific gravity and water absorption of densified wood was improved significantly. Specific gravity increased 28.86-63.03%, while water absorption decreased 12.80-15.89%. Thickness swelling of 20% densified wood was lower than that of 40% densified wood.