• Economic and Environmental Geology
• /
• v.40 no.2 s.183
• /
• pp.153-170
• /
• 2007

Loading time and loading environment of the Dokdo seamounts were studied from flexure model and VGP(Virtual Geomagnetic Pole) determined by gravity and magnetic data. In spite of their similarity in size. a large difference about 50 mGal between gravity anomaly peaks of Dokdo and the Isabu Tablemount suggests different compensation degrees. Flexural modeling results show that the flexural rigidity(effective elastic thickness) of lithosphere for Dokdo is stronger(thicker) than that for the Isabu Tablemount. Also, it implies that the age of lithosphere at the time of loading of the Isabu Tablemount may be younger than that of Dokdo. Magnetic anomalies occur complicated over the Dokdo seamounts. Paleomagnetism was studied from VGP estimated by the least square and the seminorm magnetization methods with 1500 m upward continued magnetic anomalies. Age dating of Dokdo from previous study, flexural modeling, VGP, and geomagnetic polarity time scale suggest that after the cease of spreading in the Ulleung Basin, the Isabu Tablemount was formed first in normal polarity interval and followed by Dokdo. Also, they indicate that the fist large eruption of Dokdo was in normal polarity interval and the second large eruption in reversed polarity interval. The Simheungtaek Tablemount was formed in normal polarity interval between the formations of the Isabu Tablemount and Dokdo. These loading times for the Dokdo seamounts show a good coherence with the compressive stress period after the end of the opening of the East Sea. The Dokdo seamounts probably was caused by volcanism associated with the compressive stress.

• Horticultural Science & Technology
• /
• v.31 no.4
• /
• pp.490-495
• /
• 2013

Two chrysanthemum varieties, 'ARTI-purple' and 'ARTI-queen', were chronically irradiated with doses of 30, 50, 70, and 100 Gy for four weeks in gamma-phytotron, a long term irradiation facility. We investigated the growth, responses of antioxidant enzymes (ascorbate peroxidase, APX; catalase, CAT; peroxidase, POD; superoxidase dismutase, SOD) and malondialdehyde (MDA) contents under different doses of chronic-irradiation. The five plant growth measurements including plant height, number of leaves, internode length, stalk diameter and leaf thickness were investigated immediately after four week irradiation. The plant height (p<0.001), internode length (p<0.01), the number of leaves (p<0.001) and stalk diameter (p<0.05) were significantly decreased an increasing doses of gamma-ray. Among them, especially, the internode length was remarkably decreased showing the RD50 (Reduction Dose 50) at approximately 65 Gy. The antioxidant response after four weeks of recovery period, ascorbate peroxidase (APX) (p<0.01), superoxide dismutase (SOD) (p<0.01) and peroxidase (POD) (p<0.001) were significantly increased with an increasing dose of gamma-ray. And malondialdehyde (MDA) (p<0.01) contents showed the significant increase at the 70 and 100 Gy which means the oxidative stress was lasting for a considerable period. In this study, the 50 Gy irradiation as optimal dose showed higher growth than the $RD_{50}$, it also showed insignificant differences on the antioxidant responses and MDA contents. However, the 100 Gy dose showed lower growth than $RD_{50}$.

• Horticultural Science & Technology
• /
• v.31 no.4
• /
• pp.407-414
• /
• 2013

This study was carried out to understand the physiological characteristics of 'Manpungbae' (Pyrus pyrifolia Nakai) pears through the seasonal changes of pericarp structure and anatomical differences between bagging and non-bagging treatment, and also fruit quality and peel coloration characteristics at the harvest time. The pericarp at full bloom was consists of outer epidermis, hypodermis, parenchyma cell, and inner epidermis from the exterior. The cell layers from the outer epidermis to vascular bundle increased rapidly 7-10 layers to 18-26 layers from full bloom (FB) to 77 days after full bloom (DAFB) and did not change significantly until maturity. Thus, the cell division period of 'Manpungbae' pear was until 77 DAFB and during this period, the thickness from hypodermis to vascular bundle increased from $73.1{\mu}m$ to $195{\mu}m$ in this period. Stone cells were formed from seven to 21 DAFB and stone cell clusters were formed around 49 DAFB. The cork cell layer was formed between 49 and 77 DAFB. 'Manpungbae' fruit pericarp was consists of 4.5 layers of the cork cell layers and seven layers of hypodermis which has the tannin at harvest time (161 DAFB). Comparison of the fruit enlargement and fruit structure development by bagging or non-bagging showed that 'Manpungbae' fruits without bagging had more than three cork cell layer than those with bagging at maturity. The size of stone cell clusters were varied in two treatments. Fruit weight was higher in the non-bagging treatment but there was no difference in soluble solid contents (SSC) between two treatments. The weight of the 'Manpunbae' fruit was distributed from 301 g to more 900 g and the average fruit weight was 677.2 g at harvest time, and fruits in the range of 551-800 g accounted for 71.6% of total production. The SSC, acidity and SSC/acidity ratio was $10.2-12.1^{\circ}Brix$, 0.10-1.24% and 9.76-14.31 respectively, and the SSC was higher in bigger fruit which had a very higher positive correlation with a fruit weight. However, the fruit firmness tended to be lower with fruit size which had a very higher negative correlation with the fruit weight and SSC. The cork cell layer numbers between yellowish brown and green pericarp were not different significantly, in 3.8 and 3.5 respectively.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.103-109
• /
• 2016

Polyethylene pipes has useful benefits which are anti-corrosive and flexible material, so it is used to gas pipes but also class 3 water pipes of nuclear power plant, process pipes of petrochemical plant and chemical plant. So the usage of polyethylene pipes is widely increased. But it has been limited for the usage of polyethylene, because it can not be directly detected to fusion joints by using non destructive evaluation. Polyethylene pipes are connected by two methods, one is butt fusion and the other is electrofusion. Butt fusion is widely used to connecting the pipes. It is proposed to method for determining the reliability of joints in this study that is detection of the melt flow zone at fusion joints. In this study, middle density polyethylene is used, outside diameter of the test specimen is 225mm and thickness is 20.5mm. Speed of ultrasonic of this test specimen is 2,200m/s. Test specimens were fabricated by varying the heating time which means from 0% to 130% applying time through heating plate to polyethylene for detecting melt flow zone. Also 4 additional test specimens were made, one was made that not scrapping attached surface of pipes but applying 100% of the proper heating time and the others were made to include of soil, gravel and vinly tape paper at fusion joints, that were also applied 100% of proper heating time. Ultrasonic testing to measure the melt flow zone of 20 test specimens was conducted by using 3.5MHz and 5.0MHz ultrasonic probes and melt flow zone measuring was conducted to three times at different point to one specimen. To differentiate the melt flow zone signal, post image processing was equally conducted to all test results and image levels, contrast, sharpen, threshold were adopted to all teat results and the test results were displayed gray scale. From the results, for the shorter heating times the reflection area of multiple echo have been increased, so the data was obtained from the position where it can be eliminated as much as possible. At 80% of proper heating time(168 sec.), the signal of melt flow zone was obtained clearly, so measuring could be conducted. From 7% of proper heating time(15 sec.) to shorter heating times. we could not obtain the signal because test specimen was not fused. From the result, we can verify that measuring of melt flow zone by using phased array ultrasonic imaging method is possible. And we can verify to complete and incomplete butt fusion by measuring the melt flow zone.

• Korean Journal of Poultry Science
• /
• v.30 no.1
• /
• pp.1-10
• /
• 2003

The objects of this study were to develop a new strain which has resistance to fowl typhoid, high performance in laying, and producing brown shell eggs favored by domestic consumers. Several White Leghorn (WL) breeds known as possessing genetic resistance to fowl typhoid and several brown shell egg breeds such as susceptible to the disease were used to produce the controlled strains with cross mating between the strains within the breeds and the experimental strains with crossbreeding between the breeds. The crossbred strains were Chungnong(CN) 21, 22, 23, 24, 25 and 26. The controlled strains were ISA brown CC, Hyline brown CC and Lohman brown CC. The survival rates were 99.95% for chicks of age 0∼l7 weeks and 91% for adult chickens of age 18∼72 weeks. There was no difference in survival rate between the crossbred and the controlled strains. The means of age of lst egg laying were 147 to 148 days and no difference was observed between the crossbred and the controlled. The egg Production rates of a9e 18∼72 weeks were 83.76% far the crossbred strains and 77.82% for the controlled strains, which is significantly higher in the crossbred than controlled strains by 6%. The numbers of the hen housed egg Production of age 18∼72 weeks were 292.33 eggs for the crossbred strains and 271.31 eggs fur the controlled strains. The difference of 21 eggs more produced by the crossbred than by the controlled was statistically significant. The mean egg weights of age 18∼72 weeks were 64.32g for the crossbred strains and 60.73g for the controlled strains, and the difference of 3.59g was statistically significant. The feed conversion rates during the age of 18 to 72 weeks were 2.297 for the crossbred strains and 2.454 for the controlled strains. The crossbreds were reduced feed consumption by 157g for 1kg of egg Production which was statistically significant. Haugh unit(H$.$u) at the age of 72 weeks were 82.20 for the crossbred strains and 77.82 for the controlled strains. The crossbred strains were superior quality by 4.38 H$.$u. There were no significant differences in the yolk color and the eggshell thickness between the crossbred strains and the controlled strains. The eggshell color of the crossbred strains was light brown which is the medium color of the white eggshell strains and the brown eggshell strains. The body weights at the ages of 8, 12, 18, 42 and 71 weeks were not different between the crossbred strains and the controlled strains.

• Journal of Sericultural and Entomological Science
• /
• no.11
• /
• pp.51-54
• /
• 1970

External features of silkworms are not evident during stage of larvae and pupae like in the stage of imagines. In general, therefore, sexing of larvae has been depended on Herold's gland of males or Ishiwata' sexual spots (Anterior sexual spots and posterior sexual spots) of a female 2-3 days after of the 5th age since it is relatively easy to classify in this period. Sometimes. however, we made mistake of sexing since a pair of small spot around the abdomen of 9th abdominal of males and posterior sexual spot of females was found at the same position. This study has been conducted in order to obtain essential points of classifing the above it will be summarized as follows: A. Existence of the males small spots on 9th abdominal segment were varied by races. Through observation races by races the more larvae which had the small spots were found in chinese races than the Japanese, and 57 percent of the Chinese orgin larvae of the small spot were picked among total counted males. B. The small spots were more or less roundly shaped just as posterior sexual spots of females, and these spots were colored slightly even the colors were somewhat different by races. Milky color was seen in the case of the posterior sexual spots. The small spots were observed smaller than the posterior sexual spots. It is difficult classify the sexual spots during stage of mature larvae, but it was easily classified small spots by the naked eye even in the same stage. The small spots were found at the same site of the posterior sexual spots. C. After sexing by based on the small spots and Herold's gland, the sexing through purpae bodies were carried out again to confirm its correctness. Average 5. 2 percent of more opposite sex were found in the latter. This figures supposed to be caused the location of the small spots coincide with the posterior sexual spots. D. The moths, no disorder were found in daily activities and their generative functions depend on the existence of the small spot and thickness of its color. E. It is presumed that existence of the small spots were caused by races, heredity nature, voltinism, moulting, and etc.

• Food Science of Animal Resources
• /
• v.27 no.3
• /
• pp.277-283
• /
• 2007

This study was conducted to determine the effect of mugwort powder supplementation on the fattening performance and carcass characteristics during a 14 month period (from 14 months to 27 months after birth) in 32 heads of fattening Hanwoo. Fattening Hanwoos were randomly assigned 4 treatments (8 heads/treatment): C-1 [(control (0%) with Hanwoo steers)], C-2 [(control (0%) with Hanwoo heifers)], T-1 (supplementation with 2.0% mugwort powder with Hanwoo steers) and T-2(supplementation with 2.0% mugwort powder with Hanwoo heifers). The final body weights for C-1, C-2, T-1 and T-2 at 27 months were 648.6kg, 623.1kg, 663.3kg and 620.7kg, respectively. The total gain and the daily gain were highest in the T-1 group (342.4 kg, 0.88 kg). Hanwoo steers were not significantly different from Hanwoo heifers. The feed intake for the C-1, C-2, T-1 and T-2 groups were 9.35 kg, 9.09 kg, 10.08 kg and 9.69 kg, with the T-1 value being highest. The feed conversion ratios were as follows: C-1 (11.28) > T-1 (11.48) > C-2 (11.52) > T-2 (12.57). The concentrations of total cholesterol, GOT, GPT, glucose and BUN in blood serum during the fattening period were higher after than before the experiment The total cholesterol, GOT and glucose after completion of the experiment were higher in the treatment groups than the control groups (p<0.05). The carcass body weight was higher in the treatment groups than the control groups. The back fat thickness was lower in the treatment groups (12.75-14.75mm) than the control groups (15.76-16.00mm), and the longissimus muscle area was higher in the treatment groups $(84.25-87.88cm^2)$ than the control groups $(84.00-85.25cm^2)$ with the highest over-all values in the T-1 group (p<0.05). The yield grade and quality grade point were higher in the treatment groups (2.02-2.50, 2.85-3.05 point, respectively) than the control groups (1.80, 2.55-2.80 point, respectively). In conclusion, the effects of feeding dietary mugwort powder to Hanwoo steers improved the ADG, carcass body weight, longissimus muscle area and quality grade.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.2
• /
• pp.294-300
• /
• 2010

This experiment was conducted to investigate the effects of Opuntia humifusa (OPH) extracts and methyl sulfonyl methane (MSM) supplementations on the laying productivity, egg quality and sensory characteristics of eggs in hens. Six hundred forty, 35-wk-old Lohmann brown, laying hens were randomly divided into four groups: 1) water (control), 0.12% OPH extract, 0.1% MSM, and 0.12% OPH extract+0.1% MSM. They were mixed into the feed and given for 5 weeks. Egg production rates, egg weight, feed demand ratio were not significantly different among the groups. However, OPH or MSM decreased broken egg rates by increasing thickness and firmness of egg shell but they did not show the additive effects. In addition, OPH or MSM enhanced Haugh unit, an indicator of freshness of egg, and viscosity of egg white and egg yolk. OPH or MSM maintained the freshness of eggs better the control during their storage for 10 day at $4^{\circ}C$. However, OPH+MSM did not show additive effects in their freshness. Sensory test revealed that OPH or MSM decreased fishy taste and greasy flavor and they improved texture. Overall OPH or MSM enhanced the preference of eggs. In conclusion, the supplementation of either OPH or MSM enhances egg freshness and egg quality in laying hens but they should not be supplemented together due to no additive effects.

• Progress in Medical Physics
• /
• v.16 no.2
• /
• pp.82-88
• /
• 2005

In this study, the physical compensator made with the high density material, Cerrobend, and the electronic compensator realized by the movement of a dynamic multileaf collimator were analyzed in order to verify the properness of a design function in the commercial RTP (radiation treatment planning) system, Eclipse. The CT images of a phantom composed of the regions of five different thickness were acquired and the proper compensator which can make homogeneous dose distribution at the reference depth was designed in the RTP. The frame for the casting of Cerrobend compensator was made with a computerized automatic styrofoam cutting device and the Millennium MLC-120 was used for the electronic compensator. All the dose values and isodose distributions were measured with a radiographic EDR2 film. The deviation of a dose distribution was $\pm0.99 cGy\;and\;\pm1.82cGy$ in each case of a Cerrobend compensator and a electronic compensator compared with a $\pm13.93 cGy$ deviation in an open beam condition. Which showed the proper function of the designed compensators in the view point of a homogeneous dose distribution. When the absolute dose value was analyzed, the Cerrobend compensator showed a $+3.83\%$ error and the electronic compensator showed a $-4.37\%$ error in comparison with a dose value which was calculated in the RTP. These errors can be admtted as an reasonable results that approve the accuracy of the compensator design in the RTP considering the error in the process of the manufacturing of the Cerrobend compensator and the limitation of a film in the absolute dosimetry.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.12 no.2
• /
• pp.61-71
• /
• 2004

These studies were conducted to investigate the effects of feeding dried leftover food (DLF) on growth, feed conversion and carcass characteristics of growing and finishing pigs. In experiment 1, seventy-five three-way cross-hybrids ($Yorkshire{\times}Landrace{\times}Duroc$) pigs weighing approximately 22 kg of body weight on average were assigned to five treatments in a completely randomized design. Each treatment had three replications with five pigs per replication. All pigs were fed experimental diets for 60 days. In experiment 2, seventy-five three-way cross-hybrids pigs weighing approximately 70 kg of body weight were fed experimental diets for 49 days. Each treatment had three replications with five pigs per replication. The treatments included 1) group offered control diet without DLF, 2) group offered diet containing DLF at 25%, 3) group offered diet containing DLF at 50%, 4) group offerred diet containing DLF at 25% with 10% higher protein level and 5) group offerred diet containing DLF at 50% and 20% higher protein level. Average daily gain of growing pigs was highest in control group among all the treatment groups except group offered diet containing DLF at 25% with no significant difference (P>0.05). Feed intake of DLF-offered groups were lower than that of control group while feed intake of groups fed diets containing DLF at 50% with 20% higher protein level was significantly higher (P<0.05) than that of control group. Feed conversion of growing pigs was not significantly different amont treatments although it seemed to be slightly improved in groups fed diets containing DLF at 25%. Average daily gain of finishing pigs fed diets containing DLF was significantly lower than that of control group. However there was no significant differences in average daily gain between groups fed diets containing DLF at 25% with 10% higher protein level and control group (P>0.05). Feed intakes were significantly decreased in DLF-fed groups compared to control group while there was no significant differences in feed intake between groups fed diets containing DLF with 10% and 20% higher protein levels and control group (P>0.05). Feed conversion was lowest in groups fed diets containing DLF at 25% with 10% higher protein level. However, there were no significant differences in feed conversion between groups fed diets containing DLF at 25% with 10% higher protein level and control group. Feed conversion of groups fed diets containing DLF at 50% was significantly higher than that of control group (P<0.05). Carcass weight was decreased with increasing levels of DLF in the diets. There were no significant differences in dressing percentage, backfat thickness and carcass grade among treatments. Feed cost per 1 kg body weight gain of finishing pigs was lowest in groups fed diets containing DLF at 25% with 10% higher protein level.