• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.127-136
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• 2020

This study was conducted to investigate the population characteristics of Nile tilapia (Oreochromis niloticus) in the Daegu Metropolitan City thermal effluent stream (Dalseo Stream) from January to November 2019. The collected fish were identified as 4,247 individuals of 20 species from a total of eight families. The dominant species was O. niloticus with 1,306 individuals and a high relative abundance (30.75%). The water temperature of Dalseo Stream was maintained above 10℃ throughout the year, which means that O. niloticus could inhabit it even in winter. The length-weight analysis showed a regression coefficient b of 3.1496, and a condition factor (k) of 0.0025 with a positive slope. Comparing the water temperature of Dalseo Stream and the total length of O. niloticus per investigation period, the 0-age individuals appeared May 29 when the water temperature was maintained above 22℃. In conclusion, the thermal effluent of Dalseo Stream allowed O. niloticus to survive in winter and maintain stable growth conditions and life cycles. The results of this study will inform ecological information on O. niloticus, which suggests that river management efforts should consider the management of O. niloticus populations for the conservation of fish species diversity.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.143-148
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• 2010

This study is to analyze effects of the growth of Chunhyang Young Radish (CYR) and Altari Radish (AR) according to the exposure for 31 days at low dose ${\beta}$-rays. This test has one contrast sample and eleven test samples each as to AR and CYR. The seeds from contrast and test sample were planted in the culture soil after 8 seeds were chosen from each with identical condition. The accumulated dose of test samples has been measured at consistent time on a daily basis for 31 days. The growing process and germination have been measured twice at consistent time in each week. The number of leaves, length of first leave and weight have been acquired average value by measuring for 20 and 25 days, respectively after being planted. The result of test sample in case of 25 days shows that 5% increase in length and 36% increase in weight for AR each at accumulated dose 0.01 Gy compared to the contrast sample. And the length of CYR has increased by 13~17% and 1% at accumulated dose 0.01~0.08 Gy and 0.3 Gy compared to the contrast sample. For the weight at accumulated dose 0.05 Gy and 0.23 Gy has increased by 36% and 2% compared to contrast sample. As to the number of leaves, AR has increased by 0~50% at accumulated dose 0.01-0.32 Gy compared to contrast sample. It also shows that the CYR has increased to 0~67% at accumulated dose 0.01-0.62 Gy compared to contrast sample. As a result of this study, it indicates that both AR and CYR has generally increased in their length, weight, and the number of leaves at low level accumulated dose part 0.01~0.2 Gy. The size of cell, area of nucleus and density of cell for test sample has been observed quite similar to the ones from contrast sample through microscope. In conclusion, AR and CYR irradiated by ${\beta}$-rays have estimated that they are achieved a rapid growth at low level accumulated dose region corresponding to its radiation hormesis theory. Further studies need to confirm the correlation between the radiation hormesis and the growth of the plants.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.621-631
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• 2021

The purpose of this study is to survey and analyze acorn production and characteristics of the Quercus acuta Thunb. according to the need for information on seed supply and seedling cultivation during the restoration of warm broad-leaved forests. For the survey, a total of 30 seed traps with a surface area of 1 m² were set up, 3 in each of 10 quadrats (8 in Wando, 1 in Haenam, and 1 in Jindo). The acorns that fell in the seed trap at the end of each month were collected from August to December each year between 2013 to 2016. The collected acorns were then classified into sound, damaged, decayed, or empty grade, and the number of acorns produced was calculated. In the case of sound acorns, acorn traits, such as length, diameter and weight of acorns without cupule, were measured. Duncan's multiple tests of acorn production and characteristics were conducted for comparative analysis of the annual average values with the values by year, stand, month, and treatment plot. The annual number of acorn dropped into the seed traps in each quadrat from 2013 to 2016 was 5-350 acorns/3 m² in 2013, 17-551 acorns/3 m² in 2014, 5-454 acorns/3 m² in 2015, and 14-705 acorns/3 m² in 2016. There was a large difference in acorn production between the quadrats, presumably attributed to the difference in the amount of light received due to the density of trees in the square. Annual acorn production per area was 335,000 acorns/ha in 2013, 932,000 acorns/ha in 2014, 556,000 acorns/ha in 2015, and 1,037,000 acorns/ha in 2016. That was a sharp variation of acorn production in the two-year cycle. As the fluctuation in the production of Q. acuta showed simultaneity between stands, it is judged that Quercus acuta Thunb. had a clear cycle of fruitfulness and fruitiness between forest objects. September showed the biggest amount of fallen acorns and largest damage from insect pests, indicating that preventing early fall of acorns could increase the fruiting period and enable mass production of sound acorns. There was no significant difference between annual average acorn length in each region. In the case of the acorn diameter and weight, the average values of acorns from Haenam were significantly higher than those from Wando and Jindo. There was no significant difference in the average annual acorn characteristics by month, and the average annual acorn length, diameter, and weight in November were 19.72mm, 12.23mm, and 1.64g, respectively, the highest between August and November.

• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.32-40
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• 1992

Many studies have been carried out on the graft finishing in order to improve the quality of silk fiber. Various vinyl monomers, for instance, styrene, methylmethacrylate, 2-hydroxyeth-ylmethacrylate and methacrylamide, have been used practically up to date. Among these monomers, methacrylamide has been applied as the most favourable monomer onto silk fibers in recent years. The polymerization mechanism about styrene- and methylmethacrylate-grafted silk fiber has been studied by many researchers. They proposed that free radicals were formed and vinyl monomers were polymerized in silk fibroin by graft polymerization mechanism, while active sites were varied by the types of monomer and initiator as well as by the reaction condition. In general. there is another Opinion that monomers are polymerized and impregnated in the internal side of the fiber by homopolymerization, which has not been proved experimentally yet More than 10 years have been passed since methacrylamide was applied on the silk fiber, and at the present time most finishings are being achieved by methacrylamide. However, no attention has been paid to the polymerization mechanism of the methacrylamide-treated silk fiber yeL In this paper, the treatments of methacrylamide on silk fibers were studied in aqueous solution using potassium persulfate as an initiator. The polymerization mechanism of the methacrylamide-treated silk fibers was investigated and analyzed on the basis of the results of infrared spectroscopy, amino acid analysis and scanning electron microscopy. From the results of these instrumental analyses, it can be suggested that polymerization mechanism about the methacrylamide-treated silk fibers is not performed by graft polymerization which has been accepted generally in styrene and methylmethacrylate-grafted silk fibers. The different mechanism is supposed to be due to the difference in monomer types, initiator types and treatment conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.288-295
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• 1998

Egg production of Acartia steueri was estimated in llkwang Bay, located in the southeastern coast of Korea. The equation, combining fecundity, temperature and chlorophyll a, obtained under the laboratory experiments, was applied to the in situ temperature and chlorophyll a for the estimation of field egg production. Mean egg size was $80.52{\mu}m$. Prosome length of adult females was not correlated with egg size. Egg production of field population ranged from 0.32 to $63.32{\mu}gC\;m^{-3}d^{-1}$ with a mean of $13.33{\mu}gC\;m^{-3}d^{-1}$, which were equivalent to $7.1\~1407.1\;eggs\;m^{-3}d^{-1}$ and $296.1\;eggs\;m^{-3}d^{-1}$, respectively. Fecundity of adult females ranged from 5.4 to $12.5\;eggs\;female^{-1}d{-1}$ with a mean of $8\;eggs\;female^{-1}d^{-1}$. Specific egg production rates ranged from 0.028 to 0.117 $d^{-1}$ with a mean of 0.064 $d^{-1}$. Considering the egg Production ($\%$ female body carbon) as a function of temperature and chlorophlrll a concentration, our results showed rather low fecundity, which might be underestimated. Probable cannibalism of egg by the adults were thought to be pan of the reason for this low estimated fecundity.

• Journal of IKEEE
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• v.23 no.4
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• pp.1457-1460
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• 2019

In this paper, we proposed the development of a mixed sensor parts for integrated radiation exposure protection fireman's life-saving alarm that can be location-tracked and irradiated. To measure radiation exposure dose, we use the PIN-Diode radiation measurement sensor module, a semi-conductive radiation measurement sensor that can minimize size and weight. The design for removing leakage current is carried out to enhance the characteristics of the radiation measurement sensor using PIN-Diode. The IMU sensor module is used to estimate the location of the current fireman at the same time as the accident estimate by adding together the data and the values for acceleration on the three axis. Experiments were conductied by an authorized testing agency to determine the efficiency of the proposed mixed sensor parts for integrated radiation exposure protection fireman's life-saving alarms. The cumulative dose measurement range was measured in the range of 10 μSv to 10 mSv, the highest level in the world. The accuracy was measured from ±6.3% to ±9.0% (137 Cs) and normal operation was found at the international standard of ±15%. In addition, positional accuracy was measured within ±10%, resulting in a high level of results, demonstrating its effectiveness. Therefore, it is expected that more firemen will be able to provide with superior performance integrated radiation exposure protection fireman life-saving alarm.

• Food Science and Preservation
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• v.24 no.2
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• pp.181-186
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• 2017

This study was conducted to investigate the weight loss, firmness, external color and vitamin C (VC) content of tomatoes (Lycopersicon esculentum) using non-destructive method to measure identical tomato samples during 15 days storage at low temperature and high humidity. Tomatoes were harvested at the light red stage, sorted, box packed and then stored in thermo-hygrostat ($10{\pm}1^{\circ}C$, $90{\pm}10%RH$). The quality changes in weight loss, firmness and external color were measured every 3 day interval. Weight loss was increased by $1.13{\pm}0.15%$, but it may not be considered to affect quality. Surface color of fruit was changed, especially in lightness and hue angle value. The color values were analyzed by analysis of variance (ANOVA), and the results were significant (p<0.001). Firmness of fruit declined during storage, but it did not decrease in direct proportion. On the storage of day 15, firmness was decreased to 40% of initial state. At last, all the experiment data are summarized and the relationship between firmness and weight loss is analyzed to construct a linear regression mathematical model that can predict the weight loss with the firmness value measured by non-destructive method. This research result could be useful in helping tomato exporters and suppliers to get real-time quality factor by using proposed method and regression model.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.65-72
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• 2011

The objective of this research is to develop biomass allometric equation for Pinus densiflora in central region and Quercus variabilis. To develop the biomass allometric equation by species and tree component, data for Pinus densiflora in central region is collected to 30 plots (70 trees) and for Quercus variabilis is collected to 15 plots (32 trees). This study is used two independent values; (1) one based on diameter beast height, (2) the other, diameter beast height and height. And the equation forms were divided into exponential, logarithmic, and quadratic functions. The validation of biomass allometric equations were fitness index, standard error of estimate, and bias. From these methods, the most appropriate equations in estimating total tree biomass for each species are as follows: $W=aD^b$, $W=aD^bH^c$; fitness index were 0.937, 0.943 for Pinus densiflora in central region stands, and $W=a+bD+cD^2$, $W=aD^bH^c$; fitness index were 0.865, 0.874 for Quercus variabilis stands. in addition, the best performance of biomass allometric equation for Pinus densiflora in central region is $W=aD^b$, and Quercus variabilis is $W=a+bD+cD^2$. The results of this study could be useful to overcome the disadvantage of existing the biomass allometric equation and calculate reliable carbon stocks for Pinus densiflora in central region and Quercus variabilis in Korea.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.449-462
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• 2021

We analyzed the effects of temperature on the survival, development, and reproduction of the non-diapause Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae). A 16:8 h light:dark photoperiod was supplied to the non-diapause stages of O. furnacalis. The insects were raised on an artificial diet at seven constant temperatures between 15 and 35℃ for immature stages, and eight temperatures between 13 and 33℃ for the adult stage. The survival rate of eggs exceeded 70% at all temperatures, whereas survival of larvae was as low as 7.4% at 15℃. The developmental periods of the immature stages decreased with increasing temperature, but the larval period did not decrease further at 35℃. The pupal weight increased with increasing temperature, but the female weight decreased at 35℃. Variations with different last larval instars within the colonies at different temperatures were observed. Adults produced offspring at all tested temperatures. Adult longevity and the pre-oviposition and oviposition periods decreased with increasing temperature, but the pre-oviposition period increased at 33℃. Total fecundity exceeded 400 viable eggs at 22℃ and 31℃. The mean daily fecundity during the oviposition period and the mean daily fecundity on the day of oviposition increased with increasing temperature, but decreased at 33℃. Daily fecundity sharply increased at earlier adult ages and slowly decreased thereafter. The simulated oviposition frequency was greatest at 22℃. The lower developmental threshold temperatures were estimated to be the lowest at 9.7℃ for the first instar larva and the highest at 14.7℃ for the 5th to last instar larval stage, using a linear model.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1084-1091
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• 2002

Mortierella alpina, a common soil fungus, is the most efficient organism for production of production acid presently known. Since arachidonic acid are important in human brain and retina development, it was undertaken the growing effect containing diet as a food ingredient. Arachidonic acid rich oil derived from Mortierella alpina, was subjected to a program of studies to establish for use in diet supplement. This study was compared the growth and learning effect of fungal oil rich in arachidonic acid by incorporated into diets ad libitum. Sprague-Dawley rats received experimental diets 5 groups (standard AIN 93 based control with beef tallow, extract oil 8%, and 4%, and Mortierella alpina in diet 10% and 20%) over all experiment duration (pre-mating, mating, gestation, lactation, and after weaning 4 weeks). Pups born during this period consumed same diets after wean for 4 weeks. There was no statistical significance of diet effects in reproductive performance and fertility from birth to weaning. But the groups of Mortierella alpine diet were lower of weight gain and diet intake after weaning. The serum lipids were significantly different with diet groups, higher TG in LO (oil 4%) group of dams, and higher total cholesterol in LF (M. alpina 10%) of pups, although serum albumin content was not significantly different in diet group. The spent-time and memory effect within 4 weeks of T-Morris water maze pass test in dam and 7-week- age pups did not differ in diet groups. On the count of backing error in weaning period of pups was lower in HO(extracted oil 8%) group. In the group of 10% and 20% Mortierella alpina diet, DNA content was lower in brain with lower body weight, but liver DNA relative to body weight was higher than control. Further correlation analyses would be needed DNA and arachidonic acid intakes, with Mortierella alpina diet digestion rate.