The purpose of this study is to treat the ballast water by shear stress without an environmental pollution and to find out the optimal treatment conditions. The ballast water problem is issued up as the trade activated and the cargos mobilized. To improve this problem, International Marine Organization(IMO) make the rule about the ballast water treatment with specific restrictions. Although many countries have been studying about the ballast water treatment technology, there is almost no technology that can treat the microorganisms under 50μm withoutany secondary pollution. In this study, we tried to treat ballast water by applying shear stress as the physical treatment for the sterilization and tried to find out the optimal conditions including the 100% sterilizing rate and the best economic condition.

By controlling the piston speed of the gas spring applying to the digital television stand application of the gas spring, a user can operate the elevation when the gas spring is working under long stroke(200～300 mm, the TV elevation displacement). According to stroke, by some devices with the problem rising from between the difference of external forces, the emotional quality in television elevational function is realized. The piston speed control technique is investigated to perform this experiment piston flow analysis and flow rate control for precise tubular cross section and propose a piston structure for elevation action. This study is for the development of the gas spring of the large size television stand with 50 inch over. In the gas spring development of elevation working, a device to compensate for the volume of the cylinder is generated as much the volume of the piston rod. As this study result, at the development of working gas spring, the hollow shaft is more favorable than the solid one in the apparatus to compensate for the cylinder volume generated.

The oocyte undergoes various events during maturation and requires many substances for the maturation process. Various intracellular organelles are also involved in maturation of the oocyte. During the process glucose is essential for nuclear and cytoplasmic maturation, and adenosine triphosphate is needed for reorganization of the organelles and cytoskeleton. If mitochondrial function is lost, several developmental defects in meiotic chromosome segregation and maturation cause fertilization failure. The endoplasmic reticulum, a store for Ca2+, releases Ca2+ into the cytoplasm in response to various cellular signaling molecules. This event stimulates secretion of hormones, growth factors and antioxidants in oocyte during maturation. Also, oocyte nuclear maturation is stimulated by growth factors such as epidermal growth factor. This review summarizes roles of organelles with focus on the Golgi apparatus during maturation in oocyte.

A large number of divers that are engaged in a diving apparatus fishery (DAF) have been experienced a decompression sickness. This study has two purposes. One is measurement of the diving patterns and respiration rate. The other one is to research the institutional improvement plan of the DAF. In the experiments, the diving depth, the diving time, the total ascent time and the ascent rate were about 12.4 m, 22 min, 28 s and 28.1 m/min, respectively, in Tongyeong. In the case of Geoje the diving depth, the diving time, the total ascent time and the ascent rate were about 20 m, 64 min, 17 min and 1.3 m/min, respectively. In a questionnaire survey, the diving depth was 20~29 m (56.4%) in Tongyeong and Geoje, the diving time was 50~59 min (42.9%) in Tongyeong and 70~79 min (35%) in Geoje and all of the divers experienced decompression sickness. In the investigation related to a institutional issue, both of the diving apparatus fisheries had adopted the share system. And the laws and the system for the safety of the divers were not enough in Korea. This study suggests that the license and the diving time for diver of the DAF are needed and diver protection for decompression sickness is needed in the law. And the wage payments should change from full sharing to partial sharing included a regular pay to enhance the safety of the divers.

To conduct a nuclear fuel irradiation test, the inside of the nuclear fuel rod must be assembled along with the test fuel, several different parts, and sensors, and then filled with high-pressure and high-purityhelium gas. Therefore, it is necessary to develop helium gas filling techniques that can achieve exact TIG (Tungsten Inert Gas) spot welding at a pin-hole of the nuclear fuel rod to fill helium gas into the nuclear fuel test rod. However, previous apparatuses do not have repeatability for TIG spot welding as they lack an electrode position control jig to exactly fix a TIG electrode in a high-pressure chamber, and they consume a large amount of helium gas. Therefore, a TIG spot welding apparatus was developed to easily and accurately conduct TIG spot welding and significantly reduce the gas consumption. In addition, the optimum welding conditions of this welding apparatus were established through various weld tests.

The developed machine is apparatus for laminating papers of high performance. The machine was developed easily to feed paper using servomotor in feeding parts. The existing machine can not shift using mechanical gear ratio in chain driven upper feeder. The advantage of machine can slow down and up the speed of machine and can feed in any position without waiting. Thus, production rate and volume were enhanced. greatly.

In aquaculture operations with nets including scallop aquaculture, there exist many problems as the management of fishing gears is dependent on the traditional method that has been using the pure labor forces. These give rise to the environmental contamination and increase of total fishery costs because they prevent the fishermen from reusing the fishing gears. Due to the eco-friendly issues and aggravation of the management cost, the need to automate the washing operation of the fishing gears has been required consistently. In this study, development of scallop fishing gear washing apparatus was carried out. We conducted the preliminary experiments applying Taguchi experimental method in order to find the influential factors and optimal levels to the washing performance. Based on these result, we designed the structure and the kinematic mechanism of the fishing gear washer. Final prototype was verified to be effective in maximizing the washing rate through the performance test.

As fires have frequently occurred with large scale at cultural assets and warehouses, the development of Korean type demolition fire apparatus for efficient fire fighting becomes important. In this study, structural stability is investigated for assembly model of boom and outrigger by using computational structural analysis. Analysis results of boom and outrigger unit are also compared with assembly model. As this study result, equivalent stress result of boom unit is about 6% higher than assembly model and equivalent stress result of outrigger unit is about 15% higher than assembly model.

This study was performed to have an effect on control the growth of algae such as "Actinastrum fluviatile" which occurs frequently in the aquaculture tank using by a cold plasma, and it also would be expected to promote the growth of water plants due to active element causing OH radicals in the water. In addition, it was verified on the death rate as 99.9% on the scale protrusion of "Aeromonas hydrophila" as well as E. coli, especially, under extreme conditions more than 100 million pathogenic bacterium in the aqua pet tank, the ornamental fish had to act in a safe and healthy environment at over 98% death rate within 48 hours. It has been proven to give no affect on aerobic bacteria that exist in the filter or soil because there was no residual toxicity in the water tank. As the results, it will help to develop and apply on the sterilization device in other industries as well as aquarium organisms due to adopted energy-saving algorithm and reliability in use.

고농도 유기질 폐수처리를 위해 전기화학적 방법의 사용에 있어 관심이 고조되고 있다. 전기화학적 방법의 기술은 음식물폐수 및 공업적 폐수 문제를 해결하는데 이상적 처리 방법이다. 다른 화학적 처리 방법과는 다르게 전기화학적 처리장치는 2차 폐수의 부피를 증가시키지 않고 용수와 유기질 비료로 재활용한다. 전기화학적 방법은 전해부상장치를 무기화학적 약품과 병행하여 더욱 효과적으로 음식물 폐수를 처리한다. 이 연구는 2차 처리로 초음파와 오존처리로 탈색, COD와 BOD가 격감함으로 용수 및 유기질 비료로 활용하도록 실험하였다.

This paper describes the spherical ammonium diuranate gel particles which are the intermediated material of the microsphere for an VHTR(very high temperature reactor) nuclear fuel. The characteristics of the intermediate-ADU gel particles prepared by AWD(ageing, washing, and drying) and FB(fluidized-bed) apparatus were examined and compared in a sol-gel fabrication process. The electrical conductivity of washing filtrate from the FB treating and the surface area of dried-ADU gel particles were higher than those of AWD treating. Also, an internal pore volume in dried-ADU gel particles showed a more decrease in AWD treatment than FB treatment because of decomposition of PVA affected by the washing time. However, the internal microstructures of ADU gel particles were similar regardless of the process variation.

관비재배 및 수경재배시 비료를 녹일 때 소요되는 시간과 노동력을 절감하고, 작업의 안전성 확보와 자동화를 가능하게 할 수 있는 장치의 개발을 위해 본 실험을 실시하였다. 실험은 세 종류로 수행되었다. 먼저, 효과적인 비료용해 방법을 구명하기 위해 수중펌프를 양액 통 속에 두고 양액 통의 입구에 삼베포를 깐 거름망을 설치하여 물을 스프레이하여 비료를 녹이는 방법(Spray), 수중프로펠러를 이용하는 방법(Propeller), 수중펌프를 양액 통 속에 넣어 물의 흐름을 만들어 주는 방법(Submerged), 에어컴프레서를 이용하여 양액 통 속에 공기흐름을 만들어 비료를 용해하는 방법(Airflow) 등 4개의 처리를 두고 실험하였다. Spray 처리에서 가장 시간이 짧게 소요되는 것으로 조사되었으나 농가가 실제로 적용하는데 어려움이 있어서, Spray 처리 다음으로 비료를 녹이는 시간이 짧고, 노동력을 절감할 수 있으며 양액제조 과정을 자동화 하는 것이 용이할 것으로 사료되는 Airflow 처리를 선택하였다. 두 번째 실험에서는 Airflow 처리에서 사용한 재질과 분지관수를 개선한 6지관 및 8지관 장치를 제작하여 비교 실험했는데, 6지관 장치가 비료용해시간이 짧고, 양액탱크의 입구 크기에 관계없이 사용이 가능하며, 제작이 용이하여 가장 효과적인 장치로 판단되었다. 세 번째 실험에서는 개발된 6지관 장치를 이용하여 비료를 용해하는데 소요되는 시간을 조사하여 경제성을 분석하였는데, 농가에서 수중펌프를 이용하여 비료를 용해하는 방법보다 시간은 1/8배 절약할 수 있으며 경제성이 큰 것으로 나타났다. 아울러 KNO3, Ca(NO3)2·4H2O, Fe-EDTA 등의 용해특성을 조사했다.

Marine caused pollution occurs mostly near coastal area and its main cause was known to be human feces issued from small vessels. To sterilize liquid pollutants from portable toilets of small vessels, an electrolysis treatment is judged to be the most economic and stable method considering an environment of its use. In this paper, we presents an electrolysis apparatus which is the most appropriate for sterilizing pollutants from portable toilets of small vessels and derives the minimum operating time of the apparatus for sterilizing norovirus which is a main target of marine caused pollution sources. In order to utilize renewable energy, we designed an apparatus which generates a renewable energy from solar cells. As a result, we could confirm the applicability of the proposed system with the results from experiments in three cases of different weather conditions.

목 적 : 안정피로 개선을 위해 고안된 조절이완장치를 사용하여 VDT 작업과 관련한 임상성능을 분석하 고자 한다. 방 법 : 성인 30명(26.5±4.8세)을 대상으로 조절이완장치(EK-075/30, 에스테크(주), 한국)를 사용하지 않은 상태에서 VDT 작업 전과 후 그리고 조절이완 장치를 착용 상태에서 VDT 작업 후에 굴절이상도, 원거 리와 근거리의 시력 및 수평사위도, 폭주근점, 조절근점, 양안 및 단안 조절용이성, 융합버전스를 비교분석 하였으며, 총 4단계의 설문을 통해 대상자의 전반적인 건강상태와 VDT 작업 관련 기본사항, VDT 작업 중 느끼는 자각증상, 기기착용과 관련한 사항을 설문하였다. 결 과 : 조절이완장치를 사용하지 않은 상태에서 VDT 작업 후 굴절이상도가 유의하게 증가되었고 근거 리 시력이 감소하는 것으로 나타났으며, 원거리 사위도와 근거리 사위도는 내사위 방향으로 유의하게 증가 하였고 조절용이성은 양안과 단안 모두 유의하게 감소하였다. 조절이완장치를 사용한 상태에서의 VDT 작업 후 굴절이상도, 원거리 시력, 근거리 시력, 원거리 사위도는 통계적으로 유의한 차이를 보이지 않았으나 근 거리 사위도는 내사위 방향으로 증가하였고 단안 조절용이성도 유의하게 증가하였다. 결 론 : 조절이완장치의 착용으로 VDT 작업 후의 일시적인 근시화와 내사위의 증가가 감소되고 조절용 이성이 증가된 결과로 보아 조절과 조절이완의 훈련 효과가 있는 것으로 사료된다. 조절이완장치의 착용이 근거리 작업과 관련한 안정피로를 경감시키고 근거리 작업효율을 향상시키며 나아가 삶의 질 향상에도 기여 할 것이라고 생각된다.

In the present work, bismuth nanopowders with various particle size distributions were synthesized by controlling argon (Ar) gas flow rate and chamber pressure of a gas condensation (GC) apparatus. From the analyses of transmission electron microscopy (TEM) images and nitrogen gas adsorption results, it was found that as Ar gas flow rate increased, the specific surface area of bismuth increased and the average particles size decreased. On the other hand, as the chamber pressure increased, the specific surface area of bismuth decreased and the average particles size increased. The optimum gas flow rate and chamber pressure for the maximized electrochemical active surface area were determined to be 8 L/min and 50 torr, respectively. The bismuth nanopowders synthesized at the above condition exhibit 13.47 of specific surface area and 45.6 nm of average particles diameter.

Bumblebees are widely used to pollinate crops in greenhouses and fields. Here we firstly developed an apparatus for the oviposition induction of the bumblebee Bombus ignitus using electricity. The apparatus consists of boxes for colony initiation, part of temperature control, part of heat transfer, and moving shelf. The result shows that the rates of oviposition and colony foundation in the newly developed apparatus are respectively 3.9% and 5.2% higher than in the existing apparatus using hot water. More importantly, the newly developed apparatus is 75% cheaper in costs and can more save energy than existing apparatus. These results indicate that the newly developed apparatus could serve as an effective apparatus for the oviposition induction of B. ignitus.