Einstein(1942)의 부유사량 산정식 유도과정에 있어 몇 가지 문제점들을 개선하였다. 수류조건을 판별하여 완난류 조건에서 유속의 영점높이를 산정하는 방법을 제시하고 부유사량 산정식을 일반화할 수 있는 무차원수를 도입하였다. 또한, 기준점 농도 산정의 정확성을 개선하기 위하여 최근에 개발된 소류사량 산정식으로부터 관련치를 추정하였으며, 수치적으로 또는 도표를 이용하여 해를 구해야 하는 수심적분치의 근사식을 개발하였다. Einstein의 기존 부유사

본 연구에서는 식생된 개수로에서의 난류 구조와 부유사 이동을 수치모의하였다. 난류폐합식으로는 난류모형을 사용하였다. 수치모의를 통해 평균유속, 난류강도, 레이놀즈 응력, 난류에너지 생성 및 소멸의 분포를 계산하였으며, 기존의 실험결과와 비교하였다. 식생에 의한 항력으로 인하여 평균유속이 전반적으로 감소되었으며, 이에 따라 난류강도와 레이놀즈 응력의 분포 역시 약화되었다. 침수식생의 경우, 식생높이보다 높은 구간에서는 전단에 의한 난류에너지 생성이 지배

본 연구에서는 부유입자를 포함하는 유동을 입자크기와 입자량을 달리한 몇 가지 경우에 대하여 수치적으로 해석하고 Coleman(1981, 1986)의 실험결과와 비교하였다. 완전 난류 유동장을 해석하기 위하여 k-난류모형을 사용하였으며, 농도장 해석을 위해서는 침강속도를 고려한 일반화된 농도방정식을 적용하였다. 유동과 입자의 상호작용은 Einstein과 Chien(1955)의 모형을 도입하여 수치계산하였다. 기존의 대부분 연구에서는 소유사의 두께를 고려하

본 논문에서는 파랑이 존재할 때 모래결위에서의 흐름과 부유사의 거동에 관하여 기술한다. 새로운 수치모형시스템을 구축하였으며 이를 규칙파랑을 이용한 기존 실험실 실험조건과 가상적불규칙파랑조건에 적용하였다. 흐름장 계산은 SMAC 방법에 근거한 프로그램 SOLA를 Kim 등(1994)이 일부 수정하여 제시한 프로그램을 사용하였다. 흐름계산 부모형은 x-z 면에서의 연속방정식과 Reynolds의 운동방정식을 기본방정식으로 한다. 흐름부모형으로 파랑궤적도, 전

In this thesis the legal systems related to real estate and sea area utilization are studied in order to improve them for construction of Very Large Floating Structure. Main research subjects are as follows: 1) Whether can Very Large Floating Structure be accepted or not as real estate like house and land\ulcorner 2) How can the sea area which is occupied by Very Large Floating Structure be utilized\ulcorner As the conclusion, the Very Large Floating Structure can be registered as real estate even though it is not specified by Korean law for the present. The design concept of Very Large Floating Structure can be interpreted as satisfying enough necessary conditions and factors for Very Large Floating Structure to become real estate. In the near future, we have to make improvement on the laws related with the construction of Very Large Floating Structures so that private sectors can joint the construction. In additions, a new law for various floating structures should be made as soon as possible.

This study aimed to elucidate the relationship between theoretical parameters affecting the coagulation process and the real coagulation phenomenon applied to the dye wastewater. Emphasis was placed on the effective removal of the suspend particulates. Parameters studied in this study are pH, coagulant concentration and surface potential. Optimal dosages of coagulants by the measurement of the zeta potential at lower then 25℃ are 5×10-3 M of FeCl3 and 1.4×10-6 M of Fe2(SO4)3. The results were well agreeded with the separate jar-test results. Emphasis was also placed on the relationship between water quality and the content of SS. It was found that the wastewater quality is greatly dependent on the amount of SS. At the condition with the best removal of SS, COD and DOC were reduced to 65 % and 85 %, respectively The turbidity at the above condition was reduced from 300 NTU to 0∼1 NTU. Efforts were made to clarify the behavior of the suspend solid as affecting the water quality. 12,000∼13,000 particles/l0mL in 1∼50㎛ size range particulates in the raw wastewater were reduced to 300 particle/l0mL in the same range after treatment. This research has proposed the methodology to find out the optimal condition of coagulation for small scale wastewater treatment plant or chemical coagulation process.

하상 굴착 공사는 골재 채취, 토사준설, 교량 건설 또는 하천을 횡단하여 매설하는 관로 공사 등 여러 가지 경우에 이루어지고 있다. 이러한 하상 굴착 공사 과정에서 발생하는 다량의 부유물질(SS)은 수질을 오염시키며 환경에 악영향을 미치게 된다. 본 논문에서는 현장 여건상 정교한 수치해석모형을 적용할 수 없는 경우에, 2차원 이송-확산 모형을 단순화하여 유도한 Fick 확산 모형에 의하여 부유물질의 농도를 산정하고 오탁 방지 시설 설치에 따른 부유물질

Ethylene was treated or inhibited to investigate its effect on the physiological changes related to induction of flesh browning in Fuyu persimmon fruit. The response of fruit to ethylene was so slight, that the Fuyu fruit seemed to possess a similar characteristic to non-climacteric fruit. The flesh browning was however enhanced by ethylene treatment, although any significant increment of phenolic content or PPO activity in flesh tissue was not detected. Ethylene induced not only increasing of ion leakage from fruit tissue, but the fatty acids extracted from ethylene-treated fruit tissue were also more saturated. It was suggested that ethylene be related in the changing of membrane permeablity via saturating of fatty acid in membrane lipid. That could result in increased leakage of vacuole-stored phenolic compounds, which oxidized further by PPO to cause fruit flesh to brown.

The temporal variations of the suspended material concentration (SMC) during spring-neap tidal cycle was investigated at more than 30 stations in Deukryang Bay, Korea, in 1 and 23 July, 1992. The averaged total SMC in spring tide was two times more than those in neap tide. It can be explained that the strong tidal current in spring tide disturbed bottom waters and induced higher SMC in the bay. The areal distributions of SMC for the surface and the bottom layers in the bay shows much different patterns during spring and neap tidal cycle. We concluded that the vertical stratification intensity of water mass is important factor of the horizonatal distribution of SMC in the bay.

Photosynthetic pigments and their degradation products in suspended and sinking particles collected from the Gulf of Mexico waters 1987∼88, were measured using High Performance Liquid Chromatography (HPLC). The short term variations in flux rates of chlorophylls and carotenoids as well as their degradation products were compared at the mesoscale cyclonic and anticyclonic circulation features (cold core ring and warm core ring). Chlorophyll a was the predominant porphyrin of suspended particulate matter at both CCR and WCR. Among carotenoid pigments, 19`-hexanoyloxyfucoxanthin, which is a biomarker of prymnesiophytes, was dominant pigment at both rings. Phaeophorbide a, which is produced through the grazing processes of grazers, was the predominant degraded pigment in sinking particles at the study area. Total pigment flux in CCR was an order of magnitude higher than that in WCR. Less than 1% of the standing stock of the pigments measured sank out of the upper 200 m of the WCR on any given day. Thus, suspended particulate matter in Gulf of Mexico was not recycled rapidly.

Transport rate of windblown dusts such as soil, sand, snow is proportionate to U_*^3 and U_*, friction velocity, approximately to flow velocity of wind. Therefore, through measurement and the flow velocity of wind, it turned out that,considering different velocity distributions caused by downstream distance and porosity percent,windbreaks with appropriate porosity rate to the protection area should be chosen for the optimal fence effect. In the economic respect, better are fences with gap of 20%∼30%. Among the windbreaks to have the optimal fence effect.

This study was performed at Sa-Sang Industrial area in Pusan City. To measure the total suspended particulates(T.S.P) and SO_3 following places was selected industrial area, down town, residentail area. T.S.P was collected on glass filters by High-Volume Air Sampler, SO_3 was measured by PbO_2 candle method The collected T.S.P was analyzed for various anion(for example, NO_3, SO_4, PO_4, F, Cl) by Ion Chromatography, and Pb by Inductively Coupled Plasma.

The concentration of Total Suspended Particulates(T.S.P), size distribution of suspended particulates, and soluble anions of T.S.P in atmosphere of industrial region in Busan were investigated. T.S.P was measured by High-Volume Air Sampler and particle size distribution was measured by Andersen Air Sampler. We analyzed the chemical component of the T.S.P by Ion Chromatography and measured the shape and size of T.S.P by Scanning Electron Micrography. The small size of T.S.P mainly exist in industrial region, but the large size of T.S.P mainly exist in residentail area.

The problem of supply and transport of sediment from a mountainous catchment is very important in explaining dynamic geomorphology and the hydrological cycle. The discharge of suspended sediment is determined by a morphological system. Human interference to environment is also an important, not negligible factor in sediment production. Moreover, growing concern in recent years for the problems of nonpoint pollution and for the transport of contaminants through terrestrial and aquatic ecosystem,; has highlighted the role of sediment-associated transport in fluvial systems. This study was conducted in forested and quarried catchments in order to clarify the different discharge process and the mechanism of suspended sediment dynamics for each catchment. As a forested catchment, the Yamaguchi River catchment which drains a 3.12 ㎢ area was chosen. On the other hand, the Futagami River basin, which is formed by three subbasins (1.07, 1.59 and 1.78 ㎢), as a quarried catchment was selected. These catchments are situated to the north and east of Mt. Tsukuba, Ibaraki, Japan. The discharge pattern of suspended sediment from the Futagami River basin is more unstable and irregular than that from forested catchment, the Yamaguchi River catchment. Under the similar rainstorm conditions, suspended sediment concentration from quarried catchment during a rainstorm event increases from 43 to 27,310㎎/l. However, in the case of the forested catchment it changes only from nearly zero to 274 ㎎/l. Generally, the supply source of suspended sediment is classified into two areas, the in-channel and non-channel source areas. As a result of field measurements, in the case of the forested catchment the in-channel (channel bed, channel bank and channel margin) is the main source area of suspended sediment. On the other hand, remarkable sediment source area on the quarried catchmen, is the non-channel that is unvegetated ground.

This study deals with the case of a fixed floating structure(FFS) at the mouth of a rectangular harbor under the action of waves represented by the linear wave theory. Modified forms of the mild-slope equation is applied to the propagation of regular wave over constant water depth. The model is extended to include bottom friction and boundary absorption. A hybrid element approximation is used for calculation of linear wave oscillation in and near coastal harbor. Modification of the model was necessary for the FFS. For the conditions tested, the results of laboratory experiments by Ippen and Goda(1963), and Lee (1969) are compared with the calculated one from this model. The cases of flat cylinderical structures, both fixed and floating, were taken to be in an intermediate water depth.

As per the expanding needs of marine exploitation, many floating structures have been built. Among these, box-type vessel is considered as the most basic shape, to which plant barges and crane barges belong. Stability problem is very important for vessel. In order to increase transverse stability, this paper employs bulwarks along the upper deck sides of box-type vessels and the emphasis is laid upon the effect of bulwarks on transverse stability. In the present paper, the calculation method of heeling moment acting to the ship due to hydrostatic pressure is suggested, and actual procedures of the calculation for box-type vessels with bulwarks are shown. Furthermore corresponding model tests are carried out in small water tank. Through the comparison between calculated and measured values, it is confirmed that the preset calculation method is useful. And employing bulwarks on box-type vessels is very effective for increase of transverse stability at the heeling angles from about 15 degrees to about degrees.

A matrix partitioning method is proposed for the 2-D motion analysis of floating bodies. For the numerical solution, the boundary of a floating body is approximated with a series of line segments and the governing integral equation is transformed into a system of linear equations. A new solution procedure of resulting linear equation with complex coefficients is formulated and programmed using a matrix partitioning scheme and the Choleski decomposition. From the case study, it is found that the proposed method is efficient in the motion analysis of floating bodies, especially in the calculation of hydrodynamic coefficients. Also, it requires smaller memory size and less computing time compared with conventional methods.