• Journal of Aquaculture
• /
• v.16 no.4
• /
• pp.216-222
• /
• 2003

In a simulated seawater aquaculture system, effects of different operating factors like the superficial air velocity (SAY), hydraulic residence time (HRT), protein concentration and foam overflow height on the removal of total suspended solids (TSS) by a foam fractionator, with 20 cm diameter and 120 cm height, were investigated. This experiment was performed on batch and consecutive modes for different combinations of the tested factors, using synthetic wastewater. In 5 consecutive trials, TSS concentration in culture tank water decreased faster, when the foam fractionator was operated at higher SAV and lower HRT. In batch trials, with increasing SAV, TSS removal rate increased, but decreased with increasing HRT. Higher protein concentration in the bulk solution resulted in higher TSS removal rate. TSS concentration in the collected foam condensates increased but the foam overflow rate decreased with increasing foam overflow height. Foam fractionation was effective for removing TSS in seawater aquaculture systems and its performance largely depended on the operating parameters, especially superficial air velocity.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.12
• /
• pp.945-953
• /
• 2008

Laminar film condensation of saturated vapor in forced flow over a flat plate is analysed. The problem is formulated as exact boundary-layer solution and integral approximate solution. From numerical solutions of the governing equations, it is found that the energy transfer by convection and the effect of inertia term in the momentum equation in negligibly small for low pressure but quite important for high pressure. The condensate rate, liquid-vapor interfacial shear stress and local heat transfer are strongly dependent on the reduced pressure $P_r$ and the modified Jacob number Ja/Pr.

• Solar Energy
• /
• v.20 no.3
• /
• pp.75-84
• /
• 2000

The purpose of this research is to study on the heat transfer characteristics of separate type heat pipe with a rotor. The heat transfer characteristics of the rotor condenser are various on input heat of evaporator, rotational speeds of rotor, and working fluid amount. The results obtained from the study are as follows. 1. Magnetic fluid using seal of the rotor operated in stability by a variation of temperature and rotation speeds. The configuration of magnetic fluid seal assembly was adequate. 2. Steam ejector is effective in recovering working fluid condensate in the rotor. When steam ejector is operating, the heat flux of working fluid does not change, with the wall temperature in the rotor. 3. The optimum design conditions on working fluid amount and rotational speeds are effective in evaporator volume 50%, rotational speeds 200rpm, 300rpm, and operating temperature $80^{\circ}C$. With working fluid amount increasing, overall heat transfer coefficient decreases linearly.

• Nuclear Engineering and Technology
• /
• v.25 no.3
• /
• pp.394-402
• /
• 1993

A novel framework for quantitative estimates of the benefits of signals on nuclear power plant availability and economics has been developed in this work. The models developed in this work quantify how the perfect signals affect the human operator's success in restoring the power plant to the desired state when it enters undesirable transients. Also, the models quantify the economic benefits of these perfect signals. The models have been applied to the condensate feedwater system of the nuclear power plant for demonstration.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.3 no.4
• /
• pp.215-221
• /
• 1991

Laminar film condensation of a saturated vapor in forced flow over a flat plate is analyzed by using integral method. Laminar condensate film is so thin that the inertia and thermal convection terms in liquid flow can be neglected. Approximate solutions for water are presented and well agreed with the similarity solutions over the wide range of physical parameter, Cp1(Ts-Tw)/Pr.hfg. For the strong condensation case, it is found that magnitude of the interfacial shear stress at the liquid-vapor interphase boundary is approximately equal to the momentum transferred by condensation, i.e., ${\tau}_i{\simeq}\dot{m}(U_O-U_i)$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.10a
• /
• pp.55-57
• /
• 2012

Suez운하를 이용할 경우 부산항에서 로테르담항까지의 수송거리가 11,340마일이 북극해 항로를 이용할 경우 6,860마일로 36%가 줄고 수송기간도 10일 이상 단축되므로 북극해항로를 통한 유럽과 아시아간의 상업적인 수송이 이뤄진다면 해운회사들의 물류비용이 대폭 절감될 것으로 전망된다. 이런 시점에서 2011년 9월 한-러 국장급 해운회담이 열렸으며, 2011년 11월 23일 부산 누리마루 APEC House에서 "북극해항로 상업운항의 현황과 전망"이라는 주제로 국제세미나가 개최 되었다. 현재 북극해 항로를 통과한 선박이 2007년 2척, 2008년 3척, 2009년 4척, 2010년 10척이었던 것이 2011년에는 34척 총 82만톤의 통과 수송이 이뤄졌고, 러시아 북극내의 물동량은 2백20만톤에 달할 것으로 전망되었으며, 2012년의 통과 물동량은 100만톤을 상회 할 것으로 전망된다. 이에 북극해 항로에 대한 소개와 빙하지역을 항해하는 선박에 대한 운항지침에 대하여 검토해보고저 한다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.4
• /
• pp.57-67
• /
• 2003

The purpose of the present study is to identify the drying cylinder model in paper plants and to analyze characteristics of process responses for changes in input variables. The model developed in this work is based on actual plant operation data and the steam pressure applied to the cylinder behaves as one the main variables. It is found that heat transfer coefficients from the condensate to the canvas could be represented as empirical relations based on heat conductivities and operation date. The effectiveness of the cylinder model is demonstrated by the measured moisture contents and web temperature. Using transfer functions derived from the cylinder model stability of the drying process is analyzed.

• Interaction and multiscale mechanics
• /
• v.5 no.2
• /
• pp.131-144
• /
• 2012

We study a radial basis function collocation method (RBFCM) to discretize a coupled nonlinear Schr$\ddot{o}$dinger equation (CNLSE) that governs a two dimensional rotating Bose-Einstein condensate (BEC) with an angular momentum rotation term. We exploit a RBFCM-continuation method (RBFCM-CM) to trace the solution curve of the CNLSE. We compare the performance of the RBFCM-CM with the FEM-CM. We observe that the RBFCM-CM is very robust in a coarse grid for resolving the ground state solution with many vortices when the angular momentum rotation is close to the limit. Numerical results demonstrate the efficiency and accuracy of the RBFCM-CM for computing the superfluid density of the ground level of the BEC.

• Archives of Pharmacal Research
• /
• v.5 no.2
• /
• pp.71-77
• /
• 1982

Improvements in the analytical methodology used in the gas chromatographic/mass spectral analysis of phenolic compounds from cigarette smoke are described. For the direct analysis of crude samples, pyridine extraction and the glass capillary column GC was used for the separation of phenolics as trimethylsilyl derivativatives. The separations of cigarette smoke on Carbowax 20M and SE-54 wall coated open tubular columns are given. Improved methodology for the routine quantitation of the identified components using the computer-controlled multiple ion selection technique of MS presented. Considerations pertaining to routine analyses of a multitude of complex smoke samples are also discussed.

• Molecules and Cells
• /
• v.45 no.1
• /
• pp.6-15
• /
• 2022

Phase separation is a thermodynamic process leading to the formation of compositionally distinct phases. For the past few years, numerous works have shown that biomolecular phase separation serves as biogenesis mechanisms of diverse intracellular condensates, and aberrant phase transitions are associated with disease states such as neurodegenerative diseases and cancers. Condensates exhibit rich phase behaviors including multiphase internal structuring, noise buffering, and compositional tunability. Recent studies have begun to uncover how a network of intermolecular interactions can give rise to various biophysical features of condensates. Here, we review phase behaviors of biomolecules, particularly with regard to regular solution models of binary and ternary mixtures. We discuss how these theoretical frameworks explain many aspects of the assembly, composition, and miscibility of diverse biomolecular phases, and highlight how a model-based approach can help elucidate the detailed thermodynamic principle for multicomponent intracellular phase separation.