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This study was conducted for the purpose of deriving the optimal process conditions for the pultrusion of carbon fiber–polyester composite materials. For this purpose, the mechanical characteristics were evaluated according to fiber content, curing time, and curing temperature. Tensile strength characteristics are improved as the fiber content, curing temperature, and curing time increased. But, in a fiber content of 70% over, it does not improve due to internal defects such as delamination and voids. The effect of curing temperature and curing time was analyzed through the fracture mode. Fracture characteristics due to un-curing were observed in tensile specimens. In addition, the curing reaction of the polyester as the heating rate was confirmed through differential scanning calorimetry. Finally, the optimal process conditions for the pultrusion of carbon fiber–polyester composite materials were derived.

The purpose of this study is to develop a lightweight design model for an 18ft leisure boat. The existing leisure boat is manufactured using glass fiber-reinforced plastics (GFRP) material and the hand lay-up process. Carbon fiber-reinforced plastics (CFRP) was applied to the new design to reduce the boat’s weight, while an automated tape laying machine was applied to the lightweight boat’s manufacturing process to increase boat manufacturing productivity. The newly designed CFRP model is 25% lighter than the existing GFRP model. It was confirmed that the newly designed lightweight hull has sufficient structural integrity compared to the existing hull through the structural integrity evaluation by the FEA.

The purpose of this case study is to calculate the critical condition of interfacial peeling on aluminum hybrid anti-mechanical vibration panel. An area of thin-cored resin layer with two aluminum skins is located to design a hybrid panel. The system of hybrid panel is normally used for mechanical parts, which need to dampen mechanical vibration. In this structure, a thin core plays an especially important role to dampen vibration. However, this structure has a disadvantage of delaminating and peeling with perpendicular loading from the adhesive core. At a given level of adhesion, one calculates deflection and stress state as a function of loading. To confirm that this model is directly applicable to the quantity of deflection, the geometry of three layers is designed with actual product thickness. A total of five cases of loading condition are simulated to deduce the stress distribution. The interfacial area is the main interest for this simulation which can be related with critical peeling condition. As a result, the comparison with the practical values of adhesion shows a possibility of estimation for the peeling limit of this hybrid panel system.

This research presents the structural design and mechanical performance evaluation results of a lightweight belt for high-rise elevators. Weight reduction of elevator components is indispensable in developing ultra-high-rise elevators. In this study, the structural design and performance evaluation of high-rise elevator ropes were carried out. The weight of the newly designed Carbon Fiber Reinforced Plastic (CFRP) belt was reduced by 30% compared with the original steel wire rope. The structural analysis results of the CFRP belt showed that the design criteria were met on the design load condition of the belt. Also, mechanical tests were executed to verify the mechanical characteristics of the newly developed belt, with the results showing that the belt had sufficient structural performance compared with conventional steel wire rope.

The purpose of this study is to derive the design specifications of damped aluminum laminate, applied as a component of electric vehicle, and to investigate the factors affecting the material’s characteristics. Sixty six percent light-weight component from damped aluminum laminate compared to conventional steel design was fabricated by means of finite element analysis and material tests. Various specimens with differences in resin thickness, resin type, and surface treatment agent material were prepared, while peel strength of the laminates was analyzed. It was confirmed that adhesive strength was improved as the thickness of the resin increased. Moreover, the adhesive strength of the laminate by thermosetting resin was higher than that of the panel with applied thermoplastic. Various kinds of material tests were carried out to ascertain the effect of moisture and temperature on the adhesion characteristics of the laminates. A decrease of over 30% in bonding strength due to moisture and temperature were observed from the evaluations.

This paper is a numerical study on the correlation of leakage by the variation of operating temperature and orifice diameter applying to hydrostatic bearing in hydraulic actuator. Compared with Brackbill and Kandlikar experimental paper to verify the validity of the numerical analysis technique of the present study, we derive the result that the results of experiments and numerical analysis to match very well. CFD analysis program were analyzed using a commercial code FLUENT V14.5. Inlet and outlet, were applied pressure conditions, the main variables of the analysis is temperature and the orifice inner diameter. The analysis results, pressure value has decreased as the oil temperature and the orifice diameter increases.

Lipid extraction from Scenedesmus sp. microalgae using hot compressed hexane (HCH) was investigated. Extraction performance was evaluated near the critical point of hexane and was compared with that of hexane extraction performed at room temperature and pressure, and the Bligh and Dyer extraction method. Experimental data showed that HCH significantly improves the lipid yield and rate of lipid extraction compared to the use of hexane at ambient conditions. High yields of biodiesel-convertible lipid fractions were rapidly achieved at the critical point of hexane, at a level comparable to that of the Bligh and Dyer method.

This research presents structural design and analysis results of applying a composite boom structure on a Concrete Pump Truck (CPT). Carbon Fiber Reinforced Plastic (CFRP) is used to complete the structural design of the end boom to reduce the weight of the CPT. The weight of the newly designed end boom is reduced by 32% compared to the original steel component. Structural analysis is accomplished by applying static load combinations of self-weight of the boom and the weights of the pipes, the concrete and the drain hose. The results show that the tip deflection is reduced by 30% compared to the conventional end boom. Also, equivalent stress is considerably lower than the conventional design. Composite failure evaluation of the CFRP end boom is conducted by post-processing the stress results using Puck’s failure criteria. The evaluation results show that the design criteria are met on the static load of the pump truck. Specifically, it is expected that fiber failure and inter fiber failure of the boom do not occur under loading conditions according to the design evaluation results.

This paper presents a new design procedure for large wind turbine blades, which can be used in various case studies. The structural design of 2MW CFRP blade was performed using a verified 2MW GFRP blade model. The structural integrity assessment of the CFRP model demonstrated that the design criteria for tip deformation, buckling failure, and laminate failure in normal wind turbine operating conditions were met. The existing aero-elastic analysis code was not used to estimate the blade load, but the blade’s surface pressure was calculated using CFD. The conventional load analysis code necessitates the establishment of a turbine system and the input of structural characteristics with changes in the structural design specifications. However, when CFD was used to estimate the load, the turbine system was not required and the structure was evaluated against various design cases, making this a useful approach in preliminary design. This new structural design and evaluation procedure for wind blades can be used to review diverse design specifications in the initial design stage.

In this study, a supercritical one-pot process combining transesterification and partial hydrogenation was proposed to test its technical feasibility. Simultaneous transesterification of soybean oil and partial hydrogenation of polyunsaturated compounds over Cu catalyst in supercritical methanol was performed at 320 °C and 20 MPa. Hydrogenation proceeded simultaneously during the transesterification of soybean oil in supercritical methanol, and hydrogenation occurred during the reaction despite the absence of hydrogen gas. The polyunsaturated methyl esters obtained in the biodiesel were mainly converted to monounsaturated methyl esters by partial hydrogenation. Key properties of the partially hydrogenated methyl esters were improved and complied with standard specifications for biodiesel.

An experimental study was carried out to understand the heat transfer performance of a miniature loop heat pipes using water-based copper nanoparticles suspensions as the working fluid. The suspensions consisted of deionized water and copper nanoparticles with an average diameter of 80 ㎚. Effects of the cupper mass concentration and the operation pressure on the average evaporation and condensation heat transfer coefficients, the critical heat flux and the total heat resistance of the mLHPs were investigated and discussed. The pressure frequency also depends upon the evaporator temperature which has been maintained from 60℃ to 90℃. The Investigation shows 60% filling ratio gives the highest inside pressure magnitude of highest number pressure frequency at any of setting of evaporator temperature and 5wt% results the lowest heat flow resistance.

In this work, hydrolytic reaction conditions of various temperatures (300–370 °C) and times (0–30 min) at a constant pressure of 20 MPa were applied to the thermal decomposition of three kinds of fatty acids (FAs), stearic acid, oleic acid, and linoleic acid, in subcritical water. The degradation characteristics were investigated from the derived data, and the thermal stability of FAs in subcritical water was estimated. The primary reactions we observed were isomerization and pyrolysis of FAs. The main pathway of degradation was deduced by analyzing the contents of pyrolyzed products. We found that more saturated FAs have greater thermal stability in subcritical water. All FAs remained stable at 300 °C or below. Based on these results, we recommend that hydrolysis of vegetable oils and fats using subcritical water should be carried out below 300 °C (at 20 MPa) and for less than 30 min to obtain high-yield FA production.

We report the successful application of multi-walled carbon nanotubes (MWCNTs) as electrocatalysts for triiodide reduction in dye-sensitized solar cells (DSSCs). To improve the photovoltaic performance of DSSCs, upgrade the quality of MWCNT structure and obtain an optimum deposition approach regarding a counter electrode, the present study was investigated. Three different MWCNT structures, raw, purified and purified and ground, were investigated as platinum (Pt) alternatives for counter electrodes in DSSCs. The counter electrodes were prepared on fluorine-doped tin oxide (FTO) glass substrates by two different techniques: spin coating from fluid-type MWCNTs and screen printing from paste-type MWCNTs. By utilizing a spin-coating technique, a DSSC that was fabricated with a purified and ground MWCNT counter electrode achieved an overall photovoltaic efficiency of 4.94%. This photovoltaic performance is comparable to that of a DSSC using a conventional “Pt” counter electrode fabricated under the same conditions. We found that the grinding method is powerful for increasing specific surface area and porosity. With this technique, macropores can be transformed into mesopores, thereby reducing the agglomeration of the MWCNTs, and with an additional modification, an increased DSSC photovoltaic efficiency results.

In this study, used vegetable oils (VO) were transesterified in supercritical methanol with a Cs-doped heteropolyacid (HPA) catalyst so as to produce biodiesel. The stability of the prepared catalysts was determined by measuring the amount of dissolved heteropoly anions. Cs 2.5 PW 12 O 40 exhibited the highest stability in supercritical methanol. Kinetic parameters were determined at the initial stage of the reaction to examine the reaction rate of the process. The effects of the reaction parameters, including the molar ratio of methanol to oil, reaction pressure, temperature, and time, on the content of fatty acid methyl esters (FAMEs) were also investigated in order to obtain optimum reaction conditions. The content of FAME reached 92% under the optimum reaction conditions of 260 °C, 20 MPa, a molar ratio of methanol to oil of 40, and a reaction time of 40 min in the presence of 3% catalyst. The results showed that supercritical methanol compensated for the low reaction rate of solid acid catalytic transesterification, while the Cs-doped HPA catalyst mitigated the harsh operation conditions of the supercritical methanol process.

Biodiesel production via transesterification of rapeseed oil in supercritical methanol was performed without catalysts. Response surface methodology (RSM) was used to evaluate the relationships between the content of fatty acid methyl esters (FAMEs) and reaction parameters, such as reaction temperature, reaction pressure, reaction time, and the molar ratio of methanol to oil. A central composite design was employed to fit the available response data to a second order polynomial RS model. The optimal conditions maximizing the content of FAMEs in the biodiesel were investigated. Results showed that the optimum processing conditions were 330 °C, 210 bar, a reaction time of 16 min, and a molar ratio of methanol to oil of 50 mol/mol. The predicted response value for these conditions was 93.6% methyl esters and it was in agreement with the experimental value.

The (Gd0.1Ce0.9)O2−δ (GDC)–Gd2O3 composite buffer layer was fabricated on yttria stabilized zirconia (YSZ) electrolyte by aerosol deposition for usage as diffusion barrier layer between YSZ and (La0.6Sr0.4)(Co0.2Fe0.8)O3−δ (LSCF)–GDC composite cathode. The deposited composite buffer layer was quite dense in nature and effectively prevented the formation of SrZrO3 and La2Zr2O7 interlayer with low conductivity at the interfaces. The cell's I–V performance was enhanced with an increase in the GDC content in the composite buffer layer. The cell containing composite buffer layer showed maximum power density of up to 1.74 W/cm2 at 750 °C, which was ∼30% higher than that of the cell containing GDC buffer layer prepared using conventional process.

In recent years, non-catalytic supercritical processes for biodiesel production have been proposed as alternative environmentally friendly technologies. However, conditions of high temperature and pressure that occur while biodiesel is in supercritical fluid can cause fuel degradation, resulting in low yield. In this study, we performed the thermal decomposition of fatty acid methyl esters (FAMEs) in supercritical methanol at temperatures ranging from 325 °C to 420 °C and pressure of 23 MPa to investigate the degradation characteristics and thermal stability of biodiesel. The primary reactions we observed were isomerization, hydrogenation, and pyrolysis of FAMEs. The main pathway of degradation was deduced by analyzing the contents of degradation products. We found that if FAME has shorter chain length or is more saturated, it has higher thermal stability in supercritical methanol. All FAMEs remained stable at 325 °C or below. Based on these results, we recommend that transesterification reactions in supercritical methanol should be carried out below 325 °C (at 23 MPa) and 20 min, the temperature at which thermal decomposition of FAMEs begins to occur, to optimize high-yield biodiesel production.

EPDM/organoclay nanocomposites were prepared by a melt mixing of a semicrystalline EPDM grafted with maleic anhydride and an organoclay (Cloisite 20A) in an internal mixer. XRD and TEM analysis revealed that the EPDM/clay forms a partially exfoliated nanocomposite and the silicate layers of the clay are uniformly dispersed at a nanometer scale in the rubber matrix. DSC studies indicated that the clay nanoparticles caused an increase in the nonisothermal crystallization temperature of the EPDM. Tensile and dynamic mechanical analysis showed that a small amount of the clay nanoparticles effectively enhanced the stiffness of the EPDM without adversely affecting its flexibility. The EPDM/clay nanocomposites were used to produce foams by using a batch process in an autoclave, with supercritical carbon dioxide as a foaming agent. The exfoliated nanocomposite produced a microcellular foam with average cell size as small as 6.23 μm and cell density as high as 2.4×1010 cell/cm3.

In this study, CFD analysis of air-heating vaporizers was conducted. A longitudinally finned vertical pipe was used to represent the air-heating vaporizer in the CFD model. Nitrogen gas was used as the working fluid inside the vertical pipe, and it was made to flow upward. Ambient air, which was the heat source, was assumed to contain no water vapor. To validate the CFD results, the convective heat transfer coefficients inside the pipe, hi-c, derived from the CFD results were first compared with the heat transfer coefficients inside the pipe, hi-p, which were derived from the Perkins correlation. Second, the convection heat transfer coefficients outside the pipe, ho-c, derived from the CFD results were compared with the convection heat transfer coefficients, ho-a, which were derived from an analytical solution of the energy equation. Third, the CFD results of both the ambient-air flow pattern and temperature were observed to determine whether they were their reasonability. It was found that all validations showed good results. Subsequently, the heat transfer coefficients for natural convection outside the pipe, ho-c, were used to determine the Nusselt number outside the pipe, Nuo.. This was then correlated with the Rayleigh number, Ra. The results show that Ra and Nuo have a proportional relationship in the range of 2.7414×1012 ≤ Ra ≤ 2.8263×1013. Based on this result, a relation for the Nusselt number outside the pipe, Nuo, was proposed.

Fiber reinforced plastics (FRP) have been widely used because of their high specific strength, high specific stiffness and etc. Although these kinds of FRP have various merits in applications, it has been had one of the complicated problems to manufacture their wooden mold. For these reasons, the simple methods to manufacture the mold required in the FRP industries. To improve these kinds of problems, the molding system using composite materials was developed. By this new manufacturing techniques and high functional FRP composite mold was built. Comparing with wooden mold, the process efficiencies of frame manufacturing process and inner mold manufacturing process were improved approximately 40% and 70%, respectively.

This research investigated to find out the possibilities of applying FRPs to the AUVs. In this study, two kinds of metal materials, which is one of the popularly used materials for manufacturing AUVs, and 6 kinds of FRP materials were considered. Material properties of FRPs were derived by tensile tests and chemical analysis. Moreover, various types of AUVs were designed by 8 kinds of materials. From structural analysis, we can find out that the weights of AUV by CFRP-Autoclave could be reduced by 60% in comparison with the weights of AUV by Al 7075-T6. Also, 40% weight reduction could be expected compared to the AUV by Ti-6Al-4V. In this result, we could conclude that the material of CFRP-Autoclave have various merits and potentialities as one of the AUV materials.

The degradation of polystyrene (PS) in supercritical methanol was carried out under reaction temperatures ranging from 340 to 420°C and pressures of 10–30 MPa. The selectivity of liquid products was investigated at various reaction conditions. As the reaction proceeded, the selectivity of styrene monomer, dimer, 1,3-diphenyl propane, and 1,3-diphenyl butane had a declining tendency, whereas that of the rest (i.e., toluene, ethyl benzene, isopropyl benzene, and 3-phenyl propanol, etc.) had an inclining tendency. The sequences of decomposition reaction could be reasoned by analyzing the variation of selectivity of liquid products. The kinetic behavior of PS in supercritical methanol had been investigated. The degradation processes of PS in such supercritical fluids could be formulated by the first-order kinetic law at the initial stage of reaction. The activation energy for the degradation in supercritical methanol was evaluated to be 117.2 kJ/mol and it was also compared with the activation energies for depolymerization in other supercritical fluids and that for thermal pyrolysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Due to the need for CO2 sequestration associated with H2 production from fossil fuels, zeolite membrane are very promising due to their low cost, high stability and high permeance. Recently, the faujasite(FAU), the silica/aluminophophate(SAPO-4) framework family of zeolite have been studied for CO2 gas separation. In our study, ZSM-5 membrane was prepared on the porous alumina support using a hydrothermal technique. The thickness of zeolite membrane was controlled by the hydrothermal reaction time and temperature. The prepared zeolite membranes were characterized with SEM and thin film XRD. The hydrogen permeability and selectivity toward carbon dioxide gas were 0.6x 10-6 mole/m2.s.pa and 3.16, respectively. The hydrogen selective zeolite membranes show promising application in hydrogen separation from coal gasification such as Integrated Gasification Combined Cycle (IGCC).

At present time, LNG demand of the world is increasing and the piping line for NG transportation has been already installed in Korea. The air fm vaporizer is, however, required because of the transportation for remotely local areas. This paper numerically investigates on the heat transfer characteristics of relevant geometric variations of air-fin vaporizer which is heated by air not by sea water. This vaporizer must be designed in consideration of both efficiency and economics because air is relatively a little heat source. In this study, the pipe and the longitudinal fins are fundamental geometric considerations. Main parameters of geometry are the number, the thickness, and the length of the fins. Finally, the results of heat transfer effects are investigated with the characteristics of each parameter variation.

The possible utilization of automobile shredder residue as a fuel in the cement kiln process was investigated. The detailed characteristics of the automobile shredder residues were investigated in terms of it’s chlorine content as a fuel feed and its circulation in cement kiln. For estimation of the chlorine content in the cement kiln system, the Weber model which is one of the circulation material’s forecast model was used. From the results, we estimated the chlorine by-pass rate should be 1 ~ 2 percent, for maintaining the present level of chlorine content’s on the hot-meal of the cement kiln system.

This paper investigates the effect of the pair-minerializer (CaSO4,-CaF2) on the reaction of alite, belite and calcium langbeinite formation with different alkali and sulfate contents. A set of clinker samples was prepared by adding laboratory grade reagents of (NH4)2SO4, CaF2 and K2CO3 to the cement raw mixes. The mineralogical composition of clinker was analyzed by X-ray powder diffraction, and the quantity of minerals was evaluated by using TOPAS software. As the experimental results, the total amount of calcium silicate minerals was rapidly increased with the addition of F and SO3 components simultaneously as pair-mineralizer with K2O more than the value which mineralizer was added separately. Also, in the case of adding K2O only to the raw mixes, the amount of alite is decreased after clinkering. However, if alkali (K2O) and pair-minerializer (CaSO4,-CaF2) were added simultaneously, the quantity of alite and calcium langbeinite mineral increased because of the formation of stable clinker minerals by the reaction of alkali (K2O) and sulfate.

Nanoporous SiC membrane was developed on the porous alumina plate for the hydrogen separation using preceramic polymers such as polyphenylcarbosilane. The prepared preceramic polymers were characterized with FT-IR, TGA, GPC and XRD. Nanoporous SiC membrane was derived from the preceramic polymer using a spin coating method. The SiC membrane spin coated using 20 wt.% of polyphenylcarbosilane solution in cyclohexane does not show any cracks on the surface after heat treatment at 800oC. The average thickness of the SiC membrane is about 1µm. SiC coated porous alumina possesses asymmetric pore size distribution. There are micropores that originated from porous alumina substrate, and nanopores that derived from amorphous state of SiC membranes. The pore size distribution measurement showed that the sample contains 1-3 nm sized nano pores.

In our preceding work, the simultaneous deviation from the conventional dual-mode sorption and mobility model was observed in a case of CO2 in polystyrene (PS) membrane (glass transition temperature of pure polymer = 95°C) at 60 and 70°C. The plasticization effect of sorbed CO2 on both the sorption and diffusion processes tends to be brought about in glassy polymer membranes near the glass transition temperature. The behavior was simulated based on the concept that only one population of sorbed gas molecules of plasticizing ability to the polymer should exist. In the present work, the sorption and permeation behavior for CO2 in NH3-plasma-treated and untreated PS membranes at 40°C was investigated, where NH3-plasma treatment was executed at plasma discharge powers of 40, 80, 120, and 160 W for an exposure time of 2 min. The sorption isotherm could be described by the sorption theory of Mi et al. (Macromolecules 1991, 24, 2361), where the glass transition temperature is depressed by a concentration of sorbed CO2 of plasticizing ability. NH3-plasma treatment on PS membrane had little influence on the sorption behavior of CO2 at plasma discharge powers up to 160 W. The mean permeability coefficients were somewhat increased only at a discharge power of 160 W. At CO2 pressures below 0.9 MPa, the pressure dependencies of mean permeability coefficients for CO2 in both NH3-plasma-treated and untreated PS membranes at 40°C could also be simulated on the basis of the concept that only one population of sorbed gas molecules of plasticizing ability should exist. At CO2 pressures above 0.9 MPa, however, a plasticization action of sorbed CO2 had much more influence on the diffusion process rather than on the sorption one, and such a combined concept underestimated the mean permeability coefficient. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1798–1805, 2007

The degradation of polystyrene (PS) in sub- or supercritical water was carried out at reaction temperatures ranging from 370°C to 420°C and pressures of 240 to 320 bar. At 370°C, where water is in a subcritical state, the degradation was in equilibrium in about 5 min, whereas at 380°C and 390°C, where water is in a supercritical state, it was completed in 15 and 3 min, respectively. The equilibrium conversion in the supercritical state (100 wt %) was higher than that in the subcritical water (ca. 80 wt %). The dependence on time of selectivity for the degradation products—styrene monomer, styrene dimer, styrene trimer, toluene, ethyl benzene, isopropyl benzene, and triphenyl benzene—were investigated at 400°C and 280 bar. As the reaction proceeded, selectivity for styrene monomers, dimers, and trimers decreased, whereas that for toluene, ethyl benzene, and isopropyl benzene increased because of the difficulty of decomposing the benzene rings and phenyl radicals. Triphenyl benzene increased with reaction time for the same reason. With increasing temperature, selectivity for the styrene monomers and dimers decreased slightly, whereas selectivity for toluene and ethyl benzene increased a little. The kinetic behavior of PS in supercritical water along with supercritical acetone and n-hexane were investigated. The degradation processes of PS in such supercritical fluids could be formulated by the first-order kinetic law at the initial stage of the reaction. The activation energy for the degradation in supercritical water was evaluated to be 157 kJ/mol compared to an activation energy of 132 kJ/mol in the supercritical n-hexane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 695–700, 2006

A kinetic analysis method for the degradation of polymer in supercritical fluid was proposed in this work. The method was applied to predict the degradation of polystyrene (PS) in supercritical acetone by nonisothermal weight loss technique with heating rates of 3, 5, and 7°C/min. To verify the effectiveness of the kinetic analysis method proposed in this work, the experimental values were compared with those of the numerical integration results using kinetic parameters obtained in this work. It was found that the kinetic analysis method proposed in this work gave a reliable value of kinetic parameter for PS degradation in supercritical acetone. The kinetic parameters were also compared with the values of thermal degradation of PS in the nitrogen atmosphere reported in the literature.

Polyethylene-octene elastomer (POE)/organoclay nanocomposite was prepared by melt mixing of the POE with an organoclay (Cloisite 20A) in an internal mixer, using poly[ethylene-co-(methyl acrylate)-co-(glycidyl methacrylate)] copolymer (E-MG-GMA) as a compatibilizer. X-ray diffraction and transmission electron microscopy analysis revealed that an intercalated nanocomposite was formed and the silicate layers of the clay were uniformly dispersed at a nanometre scale in the POE matrix. The nanocomposite exhibited greatly enhanced tensile and dynamic mechanical properties compared with the POE/clay composite without the compatibilizer. The POE/E-MA-GMA/clay nanocomposite was used to produce foams by a batch process in an autoclave, with supercritical carbon dioxide as a foaming agent. The nanocomposite produced a microcellular foam with average cell size as small as 3.4 µm and cell density as high as 2 × 1011 cells cm−3. Copyright © 2005 Society of Chemical Industry

The reutilization of waste plastics as a fuel in the cement kiln precalciner process was investigated. For uniform feeding into the fluidized bed calciner, waste plastics were prepared to form of pellet type by shredding, melting, pressing, cutting and screening. We examine the property of combustion for different pellet size using the Computational Fluid Dynamic analysis program to minimize a risk and to optimize condition of an actual proof plant. Based on the results from the computational fluid dynamic analysis, the waste plastic for the industrial scale experiment were used as 20mm, 50mm and 100mm in size. The experimental result of an actual proof plant showed comparatively good correlation with the computational fluid dynamic analysis.

The general cooling tower is a device for cooling water in industrial condensers or heat exchangers. The present cooling towers have defects with noises, complicated structures and environmental problems. This paper focuses on a new water cooling system using the latent heat of evaporation in an enclosed vacuum tank and a water driven ejector system. Several experiments were carried out to improve high vacuum pressure and water cooling characteristics. The ejector performance was tested with various water temperatures. Based on the vacuum pressure of the water driven ejector, the water cooling characteristics were investigated for the condensed and vaporized air and the effect of increased evaporating surface area in an enclosed tank.

The aquaculture tank is used for breeding fish in sea water which was pumped up to land. The flow characteristics in the aquaculture were investigated with varying the tank geometry and flow rate. The numerical analysis has been employed for calculating the velocity and temperature distributions in a water tank of rectangular type. The finite volume method and SIMPLE algorithm with 3-dimensional standard k-e turbulence model were used for the numerical analysis. For comparison with experimental results, the PIV system was applied to visualize the flow patterns quantitatively. The numerical results showed good agreements with the experimental results. The mean velocity and temperature versus aquarium depth were represented for various circulating flow rates. Especially, the aquaculture environment is recommended that the aquarium depth has to be d=0.5 m, and this case is the condition of higher velocity and temperature in winter season.

The rapid expansion of a supercriti cal solution (RESS) process is an attractive technology for the produc- tion of small, uniform and solvent-free particles of low vapor pressure solutes. The RESS containing a nonvolatile solute leads to loss of solvent power by the fast expansion of the supercritical solution through an adequate nozzle, which can cause solute precipitation. A dynamic flow apparatus was used to perform RESS studies for the preparation of fine anthracene particles in pure carbon dioxide over a pressure range of 150-250 bar, an extraction temperature range of 50-70 o C, and a pre-expansion temperature range of 70-300 o C. To obtain fine particles, 100, 200 and 300 µm nozzles were used to disperse the solution inside of the crystallizer. Both average particle size and particle size distribution (PSD) were dependent on the extraction pressure and the pre-expansion temperature, whereas extractor temperature did not exert any significant effect. Smaller particles we re produced with increasing extraction pressure and pre- expansion temperature. In addition, the smaller the nozzle diameter, the smaller the particles and the narrower the PSD obtained.

The natural convective heat transfer in a rectangular enclosure with a heating source has been studied by experiment and numerical analysis. The governing equations were solved by a finite volume method, a SIMPLE algorithm was adopted to solve a pressure term. The parameters for the numerical study are positions and surface temperatures of a heating source i.e., Y/H=0.25, 0.5, 0.75 and 11°C≦ΔT≦59°C. The results of isotherms and velocity vectors have been represented, and the numerical results showed a good agreement with experimental values. Based on the numerical results, the mean Nusselt number of the rectangular enclosure wall could be expressed as a function of Grashof number.

The effect of NH3-plasma treatment on glassy polyethersulfone (PES) membranes upon the diffusion process for CO2, O2, and N2. was investigated from the permeability measurements. The permeation behavior for O2 and CO2 in untreated and NH3-plasma-treated PES membranes was simulated well in terms of the dual-mode mobility model. For O2 transport, NH3-plasma treatment on PES membrane had a little influence on the diffusion process of Langmuir species and very little influence on the diffusion process of Henry's law species. For CO2 transport, it promoted the transport of Henry's law mode but had very little influence on the transport process of Langmuir species. Both the mean permeability coefficient to CO2 and the ideal separation factor for CO2 relative to N2 took maximum values at a treatment power of 40 W. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 758–762, 2004

The laminar convective heat transfer in ventilated space with various horizontal partitions was studied numerically and experimentally. For the numerical study, the governing equations were solved by using a finite volume method for various numbers Re, Gr, Pr and partition numbers. The experimental study was conducted by using a holographic interferometer. The isotherms and velocity vectors have been presented for various parameters. As the number and length of partition ncreased, convective heat transfer decreased. Based on the numerical data, correlation equations were obtained for the mean Nusselt number in term of Gr/Re2. In the region ofGr/Re2 1, the mean Nusselt number was constant.