• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.10a
• /
• pp.287-287
• /
• 2000

전북 식도 연안 정치망에서 1996년 6월에서 11월 사이 월별로 채집된 멸치 유어 이석의 일륜과 그 폭을 광학현미경과 주사전자현미경으로 관찰하여 산란기를 추정하고, 일일 성장률을 역추산하여 산란기에 따른 일일 성장률을 비교 분석하였다. 시상면 (sagittal plane)을 지나는 이석에는 부화 성장 정지선(hatch check)이 형성되었고, 그 외부를 둘러싼 난황 자어기에 형성된 것으로 추정되는 평균 4개의 불분명한 미세성장선이 관찰되었으며, 난황흡수성장정지선(yolk-absorption mark)이후에는 비교적 명확한 일륜이 형성되었다. (중략)

• Journal of Aquaculture
• /
• v.10 no.4
• /
• pp.463-472
• /
• 1997

Floating and hatching rates, size and survival activity index(SAI) of spawned eggs of red spotted grouper, Epinephelus akaara were studied to understand egg qualities during the spawning periods in 1992, 1993 and 1995. The fish spawned from mid-July to mid-August when temperature ranged 23~$28^\circC$. Floating, fertilization and hatching rates were higher in the eggs from early to middle than those from late during the spawning period. SAI ranged 1.8~9.6, and it was closely related to survival rate until mouth operning time (SMOT). Egg diameter decreased gradually with the time of spawning, while diameter of oil globule was constant during the spawning periods. Induced spawnings were carried out with one injection of HCG over 5, 000 IU/kg body weight. Floating, fertilization and hatching rates of the induced spawning eggs were higher than those of untreated ones. Thus, induced spawning method with HCG was recommended for collecting fertilized eggs in bulk. Optimal time for the collection of high quality eggs was supposed to be from early to middle during the spawning periods. Considering that egg qualities were vulnerable within the period, hatchability, incidence of malformed larvae, SMOT and SAI were factors to be considered together to get good quality of eggs.

• Korean Journal of Poultry Science
• /
• v.47 no.4
• /
• pp.237-245
• /
• 2020

This study investigated the effects of breed, laying age, and egg storage period on hatching performance. Eggs were collected from early laying period (27 to 29 weeks old) and late laying period (50 to 52 weeks old) in Hwanggalsaek Jaeraejong, Korean Rhode Island Red, and Korean White Leghorn chicken breeds. Eggs laid for each period were stored for 3, 7 and 14 days and then hatched. Fertility, hatchability, and embryonic mortality were observed to determine the hatching performance. The results showed that hatching performance was affected by breed, laying age, and egg storage period with independently or interactively. The Korean Rhode Island Red breed had the lowest hatching performance. Hatchability and early embryonic mortality rate increased in early laying period eggs compared to the late laying period, but the late embryonic mortality rate increased in late laying period eggs. Additionally, hatching performance decreased as the egg storage period increased. Using breed-specific hatching management techniques, avoiding late laying period eggs, and shortening the egg storage period to seven days after laying may improve the hatching performance.

• Korean Journal of Optics and Photonics
• /
• v.10 no.2
• /
• pp.95-101
• /
• 1999

We have studied the 1.54$\mu\textrm{m}$ forward and backward stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SRS) for various $CH_4$pressures by 1.06$\mu\textrm{m}$ Q-switched Nd:YAG laser pumping under a repetition rate of Hz in single pass. We obtained that the output of backward SRS was more efficient than that of the forward SRS. The output energy and conversion efficiency of forward and backward SRS were higher than those of SBS since SRS is a steady state, but SBS is a transient state. In a $CH_4$gas uncirculating system, the output energy of the backward SRS and SBS were reduced the about 47% due to a thermal heating of $CH_4$medium in a focusing region for a repetition rate of 5 Hz. But, the output energy of forward SRS was slightly enhanced by about 8.5% due to the increase of the undepleted pump beam in the backward SRS generation. Inthe Raman half resonator using a dichromatic focusing lens, the conversion efficiency of SRS was more than 37% for a input pump laser energy of 40 mJ.

• Journal of radiological science and technology
• /
• v.32 no.4
• /
• pp.393-399
• /
• 2009

In this study, we measured the dose distribution of scattered ray in X-ray radiography room using an ion chamber and examined the dependency of scattered ray content on the scattered ray source and exposure condition. To study the factors of scattered ray occurrence in the acryl phantom, we measured the change in the scatted ray content according to the X-ray tube voltage (40~140 kV) and the field size ($10{\times}10\;cm^2$, $20{\times}20\;cm^2$, $35{\times}35\;cm^2$). For the $35{\times}35\;cm^2$ field size, the side-scattering rate ranged from 3.1% to 14.5%. The scattered ray contributions of the phantom, collimator, X-ray tube and wall were also measured. The scattered ray contribution of the phantom was higher than 95.4% for the entire tube voltage, and those of the collimator, X-ray tube and wall were 2.6%, 1.3% and 0.7%, respectively.

• Proceedings of the Malacological Society of Korea Conference
• /
• 2001.11b
• /
• pp.138-139
• /
• 2001

• Proceedings of the Malacological Society of Korea Conference
• /
• 2001.11a
• /
• pp.19-20
• /
• 2001

• KOREAN POULTRY JOURNAL
• /
• v.53 no.10
• /
• pp.124-127
• /
• 2021

고병원성 AI 발생, 계란 살충제 파동, 저난가 시대 등 지난 3년간 산란계 산업에 많은 어려움들이 있었다. 이러한 어려움 속에서도 30년 넘게 양계업을 해오며 높은 산란 성적률을 보여주며 2대를 이은 농장 운영으로 탄탄한 사육 현장을 보여주고 있는 충남 아산시 소재의 신창농장의 김병규 대표를 찾았다.

• Proceedings of the KAIS Fall Conference
• /
• 2000.10a
• /
• pp.259-261
• /
• 2000

본 연구는 사료내 인분해효소 phytase을 첨가하여 곡류내 유기태인의 이용성을 최대화하고 인의 배설량을 최소화하므로서 저공해성 산란계 사료 개발에 기초자료로서 활용하는데 목적이 있다. 부화 후 64주령된 갈색 하이라인 24수(평균체중 1.9kg, 산란율 78.4%)를 공시하였다. 대조구는 옥수수-대두박 위주로 배합된 사료, 처리구는 대조구 사료에 각각 phytase를 200 unit/kg, 400 unit/kg 그리고 600 unit/kg 첨가한 구로서 4처리 3반복, 반복당 2수씩 완전임의 배치하였다. 건물과 질소 이용률을 보면 처리간의 차이는 보이지 않았다(P>0.05). 광물질 중 회분과 칼슘의 경우 phytase를 200 unit을 첨가한 구에서 가장 높은 이용률을 보였다(P<0.05). 인의 이용률은 phytase를 600 unit 첨가한 구가 57.64%로 다른 처리구보다 이용률이 높은 것으로 나타났다(P<0.05). 칼슘의 섭취량과 배설량을 고려한 결과 칼슘의 축적량은 phytase를 200 unit와 400 unit 첨가한 구가 대조구와 phytase를 600 unit 첨가한 구보다 높았다(P<0.05). 산란계에 대한 각각의 인의 섭취량을 보면 phytase를 600 unit 첨가한 구가 대조구, 200 unit 첨가한 구, 400 unit 첨가한 구보다 많은 양을 섭취하였으나(P<0.05), 인의 배설량에는 별다른 차이가 없었다(P>0.05). 그로 인해 인의 축적량 또한 phytase를 600 unit 첨가한 구가 다른 처리구에 비해 많이 축적되었다(P<0.05). 혈중 칼슘의 함량은 phytase를 400 unit 첨가한 구와 600 unit 첨가한 구, 대조구간에는 서로 유의적인 차이가 없었고, phytase를 200 unit 첨가한 구보다 그 함량이 높게 나타났다(P<0.05). 결론적으로 산란계 사료에 phytase를 첨가할 때 환경문제를 야기시킬 수 있는 인의 배설량을 감소시키고 값비싼 무기태 인의 일부를 대체하는데 크게 기여할 수 있으리라 사료된다.

• Journal of Aquaculture
• /
• v.4 no.2
• /
• pp.85-95
• /
• 1991

Spawning inducement of flounder, Paralichthys olivaceus, was attemped by the control of water temperature and photoperiod from June 1, 1989 through January 5, 1990 (189 days) Water temperature was gradually decreased from $21.7^{\circ}C$ to $10.6^{\circ}C$ which was the minim biological temperature for spawning of flounder. Water temperature was increased asain to $15^{\circ}C$ gradually, and then maintained at this level through the end of spawning. Photoperiod was also changed gradually from 10L/14D in June 1, 1989 to 14L/10D in July 25, 1989. Spawning of the fish occurred from October 4, 1989 through January 5, 1990 (93 days). The average number of eggs spawned during the spawning season per female were 2.67 billion. The first spawning occurred on the 60th day after the time of minimun water temperature $10.6^{\circ}C$. The water temperature and photoperiod at the first spawning were $13^{\circ}C$ and 14L/10D respectively It took 71 days to spawn since the photoperiod had changed from 10L/14D to 14L/10D. Spawning period can be devided into three terms. The first term was continued for 30 days from the beginning of the spawning. The second term for 41 days was the major spawning period followed by the third term, the final period of the spawning, for 22 days. The percentage of average fertilization rate of the eggs in the first, second and third spawning terms were $37.4{\%},\;54.1\%\;and\;19.6\%$, respectively. Feeding rate was increased in the maturing period but, decreased in the spawing period. During the final spawning period, the abrubt decreasing of the feeding occurred again.