• 한국수산과학회지
• /
• 제43권2호
• /
• pp.159-168
• /
• 2010

This paper presents a mathematical model and simulation method for investigating the performance of set net systems and fish cage systems influenced by currents and waves. Both systems consist of netting, mooring ropes, a floating collar and sinkers. The netting and ropes were considered flexible structures and the floating collar was considered an elastic structure. Both were modeled on a mass-spring model. The structures were divided into finite elements and mass points were placed at the mid-point of each element, and the mass points were connected by mass-less springs. Each mass point was subjected to external and internal forces and the total force was calculated at every integration step. An implicit integration scheme was used to solve the nonlinear dynamic system. The computation method was applied to dynamic simulation of actual systems simultaneously influenced by currents and waves in order to evaluate their practicality. The simulation results improved our understanding of the behavior of the structure and provided valuable information concerning the optimized design of set net and fish cage systems exposed to an open ocean environment.

• Journal of Korean Neurosurgical Society
• /
• 제41권2호
• /
• pp.105-110
• /
• 2007

Objective : This purpose of this study was to determine the clinical efficiency and applicability, and to analyze the radiologic findings of the anterior cervical approach using two synthetic cages for interbody fusion. Methods : A total of 41 patients with cervical diseases underwent anterior discectomy and interbody fusion with the PEEK $Solis^{TM}$ cage in 21 patients and the carbon composite $Osta-Pek^{TM}$ cage in 20 patients. Outcome assessment was done using Odom's criteria. Radiological assessment was performed with respect to subsidence, bony fusion and lordosis. The mean follow-up period was 13 months. Results : There were 34 [92.9%] successful cases. The average height of the disc space 12 months after surgery compared the height just after surgery was decreased over 3mm in 4 cases, indicating severe subsidence. The use of these synthetic cages have provided the increase in postoperative cervical lordosis. Conclusion : There were no significant differences between the $Solis^{TM}$ and $Osta-Pek^{TM}$ cages on clinical and radiologic outcomes. Both $Solis^{TM}$ and $Osta-Pek^{TM}$ cages showed low subsidences and complications associated with hardware with good clinical outcomes, high fusion rates, restored disc heights, and restored cervical lordosis.

• Bulletin of the Korean Chemical Society
• /
• 제30권2호
• /
• pp.445-448
• /
• 2009

This study examined the effect of the uptake of one and two electrons on the atomic structure of three isomers of $C_{20}$ clusters, namely the ring, bowl (corannulene like), and cage (the smallest fullerene). Geometry optimizations were performed using the hybrid density functional (B3LYP) methods for neutral, singly and doubly charged $C_{20},\;{C_{20}}^-,and\;{C_{20}}^{2-}$. These results show that the symmetry of the lowest energies for ring and bowl isomers were not changed, whereas the increasing order of energy for the cage (the smallest fullerene) isomers was changed from $D_{2h}\;<\;C_{2h}\;{\leq}\;C_2\;of\;C_{20}\;through\;Ci\;<\;C_{2h}\;<\;C_2\;<\;D_{2h}\;of\;{C_{20}}^-\;to\;Ci\;<\;C_2\;<\;D_{2h}\;<\;C_{2h}\;of\;{C_{20}}^{2-}$. The reduced symmetry isomers of the cage have comparative energy and the ground state symmetry of the neutral and single and double charged $C_{20}$ decreased with increasing number of electrons taken up in the point of energetics. Interestingly, the difference in energy between the ground state and the next higher energy state of ${C_{20}}^{2-}$ was 3.5kcal/mol, which is the largest energy gap of the neutral, single anion and double anion of the cage isomers examined.

• Carbon letters
• /
• 제5권2호
• /
• pp.68-74
• /
• 2004

The polymer with contents of $C_{60}$ up to 57 wt.% was produced by mutual condensation of fullerene $C_{60}$ and ethylenediamine. The investigations of this polymer as well as pristine fullerene to comparison were carried out by FT-IR and UV-Vis spectroscopy, ToF-SIMS, TGA, and elemental analysis. At least three kinds of components was revealed as building blocks of polymer. The fullerene cage underwent only distortion but didn't destroy during formation of polymer. The pure fullerene was found as an intermediate of the thermal decomposition of polymer. The conclusion that this polymer could serve as precursor to produce carbon nanomaterial with high concentration curved graphene sheets and can be used for gas adsorption and electrochemical application was made.

• 한국식품영양과학회지
• /
• 제30권6호
• /
• pp.1283-1286
• /
• 2001

마크로파지의 활성을 조사하기 위해 carbon clearance time을 조사한 결과 AEY 처리구가 control이나 CEY 처리구에 비해 짧았다. 특히 AEY 500$\mu\textrm{g}$ 처리에서 carbon clearance 시간이 5분으로 control에서 9.42분, CEY(250$\mu\textrm{g}$ 처리)에서 9.01분보다 유의성 있는 감소를 보였다. AEY 처리에 의해 응집소가와 용혈소가가 다소증가되었다. SRBC처리 1일째와 3일째에 250$\mu\textrm{g}$ 처리구를 비교해 보면, control, CEY, AEY의 응집소가는 각각 5.50, 5.63, 6.00 및 5.25, 5.38, 5.50로 용혈소가는 각각 4.75, 5.38, 5.50 및 4.25, 5.63, 5.63으로 AEY 처리구가 control, CEY 처리구에 비해 면역 활성이 있었지만 유의성은 없었다.

• Toxicological Research
• /
• 제7권2호
• /
• pp.165-171
• /
• 1991

Effects of forced physical exercise on the CCl4 hepatotoxicity were examined in adult female rats. Rats were treated with CCl4 (2 mmol/kg, ip) and introduced into a cylindrical cage rotating at 9 rpm for 20 min/hr for 6 hr. Eighteen hr following the termination of exercise serum sorbitol dehydrogenase (SDH), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) activities and glucose-6-phosphatase activity were determined as parameters for hepatotoxicity. Physical exercise inhibited the $CCI_{4-}$induced increases in SDH, GOT, GPT activity, and glucose-6-phosphatase activity were determined as parameters for hepatotoxicity.

• 한국해양학회지:바다
• /
• 제10권4호
• /
• pp.181-195
• /
• 2005

해상어류가두리양식장의 양식 활동이 해양환경에 미치는 영향을 파악하기 위해 통영주변의 해상어류가두리양식장(Site A)에서 해수유동, 퇴적물, 저서동물 및 트랩 등의 현장조사와 수치모델-DEPOMOD를 이용하여 가두리양식장의 고형물 침강량 예측과 적정 고형물 침강량 산정으로 해상가두리양식장의 환경관리 방안을 제시하였다. 조사대상인 Site A 해상어류가두리양식장의 입식 어종은 common sea bass(Lafeolabrax japonicus), red seabream(Pagrus major), striped breakperch(Oplegnathus fasciatus) 등 4종이고, 입식량은 227,800미 (23.1MT) 였다. 가두리양식장의 입식밀도는 $43.0kg\;m^{-2}(6.1kg\;m^{-3})$ 이고, 사료투여 량은 $30.8g\;kg^{-1}day^{-1}(1.32kg\;m^{-2}day^{-1})$ 이였다. Site A 가두리양식장 중심의 저층 퇴적물의 ORP, AVS, COD, 탄소 및 질소 농도는 각각 -334.6mV, $0.43mg\;g^{-1}dry,\;17.75mg\;g^{-l}dry,\;10.19mg\;g^{-1}dry$ 및 $3.49mg\;g^{-1}dry$ 였다. 저서동물은 Capitella capitata가 $57.8\%$로 우점하였고, Infaunal Trophical Index(ITI)는 가두리 가장자리에서 20m 거리 내까지 20 이하로 나타났다. 트랩조사 결과 Site A의 고형물 침강량은 0m에서 $34,485g\;m^{-2}yr^{-1}$, 42m지점에서 $18,915g\;m^{-2}yr^{-1}$침강하는 것으로 나타났다 모델 예측 결과 Site A의 사료 미섭이율은 $40\%$, 연간 고형물 침강량은 63,401 kg으로 연간 사료 급이량의 $24.4\%$이고, 고형물 침강 면적은 $8,450m^2$으로 가두리 시설 면적의 16배인 것으로 예측되었다. ITI와 저서동물의 풍도를 통한 Site A의 지속 가능한 고형물 침강량은 $10,000g\;m^{-2}yr^{-1}$ 이하 인 것으로 예측되었다. 가두리양식장에서 고형물 침강량의 주 요인은 높은 미섭이율이고, 고형물 침강량을 최소화 하기 위해서는 사료 섭이효율을 높여주어야 한다. 모델에 따르면 미섭이율을 $40\%$에서 $10\%$로 줄이면 고형물 침강량이 1/2 수준으로 감소되는 것으로 예측되었고, 습사료, 생사료의 사용 대신에 배합사료(EP)를 사용할 경우 $57\%$정도 침강량이 감소하는 것으로 나타났다. 또한 가두리양식장의 허가면적에 대한 시설 면적비는 $5\%$미만이 적정한 것으로 판단된다.

• 해양환경안전학회지
• /
• 제28권5호
• /
• pp.735-745
• /
• 2022

본 연구에서는 어장환경평가가 수행된 어류가두리 양식장의 조사 결과 중 일부를 대상으로 저서동물지수(Benthic Health Index, BHI)를 이용하여 양식장의 건강도를 평가하였으며, 평가 결과로 산출된 각 등급의 양식장 환경 특성을 파악하였다. 평가대상 어류가두리 양식장은 동해, 서해, 남해에 위치한 43개 양식장으로, BHI 1등급은 8개 양식장, 2등급은 4개 양식장, 3등급은 12개 양식장, 4등급은 19개 양식장이 포함되었다. 1등급 어류가두리양식장은 사질 퇴적상, 양식강도가 낮은 양식장이 포함되었으며, 2등급 어류가두리양식장은 해수유통이 원활한 해역에 위치한 양식장이 속하였다. 3, 4등급이 속한 어류가두리양식장은 높은 강도로 양식 활동이 진행되고 있는 대다수의 양식장이 포함되었다. 3등급과 4등급의 양식장은 총유기탄소는 큰 차이가 없었으나, 다모류 군집분석의 결과는 4등급의 양식장에서의 유기물 농축이 더 높은 것으로 나타났다.

• 한국수산과학회지
• /
• 제56권4호
• /
• pp.473-483
• /
• 2023

This study was conducted to better understand the impact of marine fish farming by estimating mass balances of carbon and nitrogen. According to the results, 94.55% of carbon and 95.66% of nitrogen inputs were from the feed supplied in the farm. Of the total carbon emissions in the farm, 47.28% was due to fish respiration, which was subsequently released into seawater. Advection and diffusion in the farm contributed to 30.29% of the carbon released. In the case of nitrogen, 50.70% of the nitrogen released into the seawater was produced by fish excreta, and 31.37% was advected and diffused into the system. The sedimentary environment received 3.82% and 3.10% of the carbon and nitrogen released from the farm, respectively. The fish feed used for healthy growth contained 11.64% carbon and 9.17% nitrogen. Since the feed type was floating pellets, the load released into the sedimentary environment was relatively lower than that released into the marine environment. These findings suggest that the identification of an optimal fish feed that respects fish physiology and preserves a healthy ecology is critical for the future of aquaculture. Furthermore, ecosystem-based aquaculture systems that decrease environmental burden, while endeavoring to improve environmental health, are required.

• Bulletin of the Korean Chemical Society
• /
• 제26권1호
• /
• pp.63-71
• /
• 2005

Equilibrium geometries, electronic structures, and energies of borocarbon clusters (binary compounds of carbon and boron), an unexplored class of molecules with highly unusual characteristics and potential for further development, have been investigated by means of B3LYP/6-311+G$^*$ density functional theory computations. A large number of B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ clusters with planar and non-planar monocyclic and polycyclic rings, as well as cage structures, have been systematically studied. Unexpectedly, planar forms are predicted not only to be the most stable structures, but also, in many cases, to have unprecedented planar heptacoordinate boron (p-heptaB) and planar heptacoordinate carbon (p-heptaC) arrangements. All these pheptaB and p-heptaC have 6π electrons and are aromatic according to the nucleus independent chemical shift (NICS). This novel bonding pattern is analyzed in terms of natural bond orbital (NBO) analysis. For virtually all possible B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ combinations, the p-heptaB arrangements are the more stable than other type structures.