Heat transfer and fluid flow are studied numerically for a repeating microchannel array with water as the circulating fluid. Generalized transport equations are discretized and solved in three dimensions for velocities, pressure, and temperature. The SIMPLE algorithm is used to link pressure and velocity fields, and a thermally repeated boundary condition is applied along the repeating direction to model the repeating nature of the geometry. The computational domain includes solid silicon and fluid regions. The fluid region consists of a microchannel with a hydraulic diameter of 85.58μm. Independent parameters that were varied in this study are channel aspect ratio and Reynolds number. The aspect ratios range from 0.10 to 1.0 and Reynolds number ranges from 50 to 400. A constant heat flux of 90 W/cm2 is applied to the northern face of the computational domain, which simulates thermal energy generation from an integrated circuit. A simplified model is validated against analytical fully developed flow results and a grid independence study is performed for the complete model. The numerical results for apparent friction coefficient and convective thermal resistance at the channel inlet and exit for the 0.317 aspect ratio are compared with the experimental data. The numerical results closely match the experimental data. This close matching lends credibility to this method for predicting flows and temperatures of water and the silicon substrate in microchannels. Apparent friction coefficients linearly increase with Reynolds number, which is explained by increased entry length for higher Reynolds number flows. The mean temperature of water in the microchannels also linearly increases with channel length after a short thermal entry region. Inlet and outlet thermal resistance values monotonically decrease with increasing Reynolds number and increase with increasing aspect ratio. Thermal and friction coefficient results for large aspect ratios (1 and 0.75) do not differ significantly, but results for small aspect ratios (0.1 and 0.25) notably differ from results of other aspect ratios.

A set of experiments was designed and performed to gain a fundamental understanding of various aspects of the segregated network concept. The electrical and mechanical properties of composites made from commercial latex and carbon black are compared with another composite made from a polymer solution. The percolation threshold of the emulsion-based composite is nearly one order of magnitude lower than that of the solution-based composite. The segregated network composite also shows significant improvement in both electrical and mechanical properties with low carbon black loading, while the solution-based composite achieves its maximum enhancement at higher carbon black loading (~25wt%). The effect of the particle size ratio between the polymer particle and the filler was also studied. In order to create a composite with an extremely large particle size ratio (> 80,000), layer-by-layer assembly was used to coat large polyethylene particles with the carbon black. Hyper-branched polyethylenimine was covalently grafted to the surface of polyethylene to promote the film growth. The resulting composite has a percolation threshold below 0.1 wt%, which is the lowest percolation threshold ever reported for a carbon-filled composite. Theoretical predictions suggest that the actual percolation threshold may be lower than 0.002 wt%. Finally, the effect of the emulsion polymer modulus on the segregated network was studied. Monodispersed emulsions with the different glass transition temperature were used as the matrix. The composites made using the emulsion with higher modulus show lower percolation threshold and higher conductivity. Higher modulus causes tighter packing of carbon black between the polymer particles. When the drying temperature was increased to 80°C, the percolation thresholds became closer between some systems because their moduli were very close. This work suggests modulus is a variable that can be used to tailor percolation threshold and electrical conductivity, along with polymer particle size.

Microchannels have been studied extensively for electronic cooling applications ever since they were found to be effective in removing high heat flux from small areas. The rate of heat removed using microchannels depends on many factors including the geometry shape, solid and fluid materials used, and surface roughness, among others. Many configurations of microchannels have been studied with various materials and compared for their effectiveness in heat removal. However, there is little research done so far in using Phase Change Material (PCM) fluids and pin fins in microchannels to enhance the heat transfer. PCM fluids exhibit greater heat transfer when the phase change material undergoes liquid-to-solid transformation. Staggered pins in microchannels have also shown higher heat removal characteristics because of the continuous breaking and formation of the thermal and hydrodynamic boundary layer; they also exhibit higher pressure drop because pins act as flow obstructers. This paper presents numerical results of circular, square, straight rectangular microchannels with various aspect ratios (1:2, 1:4 and 1:8), and rectangular microchannels with two characteristic staggered pins (square and circular, fixed height with no variation in aspect ratio). The heat transfer performance of a single phase fluid and PCM fluid in all of these microchannels and the corresponding pressure drop characteristics are also presented. An effective specific heat capacity model was used to account for the phase change process of PCM fluid. Comparison of heat transfer characteristics of single phase fluid and PCM fluid are presented for all the geometries considered. Among the straight microchannels, 1:8 geometry was found to have the highest Nusselt number. The use of PCM fluid in straight microchannels increased the Nusselt number by 3-7 percent compared to the single phase fluids. Among the staggered pin microchannels, circular pins were found to be more effective in terms of heat transfer by exhibiting higher Nusselt number. Circular pin microchannels were also found to have lower pressure drop compared to the square pin microchannels. Overall, for all the geometries considered, it was found that the PCM fluid enhances the heat transfer compared to the SPF fluid.

Interest in biodiesel has piqued with advent of stringent emissions regulations. Biodiesel is a viable substitute for petroleum diesel because biodiesel produces significantly lower particulate and soot emissions relative to petroleum diesel. Higher nitric oxide (NO) emissions for biodiesel, however, are of primary concern in biodiesel-fueled engines. Search for an in-cylinder technique to reduce NO emissions for biodiesel has motivated studies to gain an improved understanding of fundamental factors that drive increase in NO emissions with biodiesel. Potential factors include fuel-bound oxygen, fuel-bound nitrogen and post-flame gas temperature. The role of fuel-bound oxygen however is debated in the literature. The research objective of this study is to computationally determine if biodiesel and petroleum diesel yield equivalent concentrations of NO with the same oxygen equivalence ratio in a 0-D homogeneous reactor, to explain the role of fuel-bound oxygen in biodiesel on increases in NO emissions with biodiesel. The results from this study indicate that the biodiesel surrogate yields higher NO emissions than the n-heptane because of its lower oxygen consumption efficiency. The lower oxygen consumption efficiency for biodiesel is likely because of the slower decomposition of the individual components and the blending ratios of the biodiesel surrogate blend. The relative differences in combustion efficiency of individual components of the biodiesel blend suggest this conclusion. The more efficient burning of the methyl esters relative to the n-heptane in biodiesel surrogate perhaps indicates the favorable role of fuel-bound oxygen in the fuel’s combustion. The low utilization of oxygen by the biodiesel surrogate could not be explained in this study. The dominance of NO2 H ↔ NO OH and N NO ↔ N2 O mechanisms during biodiesel combustion however explain the high NO emissions for the biodiesel surrogate relative to the n-heptane. The biodiesel may yield lower NO emissions than the petroleum diesel if the blending ratios for the biodiesel are adjusted such that combustion efficiency of biodiesel and petroleum diesel is same or the NO2 H ↔ NO OH and N NO ↔ N2 O mechanisms are suppressed during biodiesel combustion.

In recent years, the development and use of biofuels have received considerable attention due to the high demand for environmentally acceptable (green) fuels. Most of the recent studies have looked at the processes of converting vegetable oils into biodiesel. It is well known vegetable oil to biodiesel conversion involves many processes including transesterification, which makes biodiesel costly and time-consuming to produce. In this study, the effects of blending high-viscosity fresh and used corn oils with low-viscosity diesel and jet fuel mixed with butanol and ethanol were studied. Several corn oil-based blends were formulated and characterized to understand the effect of composition on viscosity, fuel stability and energy content. The formulated corn oil blends were combusted in a 30 kW modified combustion chamber to determine the corresponding NOx and CO emission levels, along with CO₂ levels. Used corn oil was made by simply heating fresh corn oil for a fixed period of time (about 44 hours), and was characterized by quantifying its total polar material (TPM), iodine value, free fatty acid content, and peroxide value. The combustion experiments were conducted at a constant heat output of 68,620 kJ/hr (19 kW), to observe and study the effects of equivalence ratio, swirl number, and fuel composition on emissions. Used corn oil blends exhibited better combustion performance than fresh corn oil blends, due in part to the higher unsaturation levels in fresh corn oil. NOx emissions for used corn oil increased with swirl number. Among all the blends, the one with the higher amount of diesel (lower amount of corn oil) showed higher NOx emissions. The blend with fresh corn oil showed decreasing NOx with increasing equivalence ratio at swirl number 1.4. All blends showed generally decreasing CO trends at both swirl numbers at very lean conditions. The diesel fuel component as well as the alcohols in the blends were also important in the production of pollutants. Compared to the diesel-based blends mixed with used corn oil, butanol, and ethanol, the jet fuel-based blends showed higher NOx levels and lower CO levels at both swirl numbers.

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Turning back to look Kaohsiung city¡¦s development and history of exploitation, both of them had a close relationship with the Love River and Chianjen River. Along the rivers, there are numerous industrial estates and large population. The basin of the rivers is important in politics and economy to Kaohsiung. However, the development of Kaohsiung also causes organic pollution, such as polycyclic aromatic hydrocarbon (PAHs), released to water system. Furthermore, some of these pollutants are carcinogenic, so that this topic is quite important. This study investigates PAHs concentrations and seasonal variations in sediments and suspended solids of these two rivers. Total PAHs concentrations varied from 110 to 4300(ng g-1 dry wt) in sediments and 1500 to 7000(ng g-1 dry wt) in suspended solids of the Love River. Total PAHs concentrations of sediments and suspended solids of the Chianjen River exhibited in the range of 230-3900 (ng g-1 dry wt) and 490-9200 (ng g-1 dry wt), respectively. The average PAHs concentration during rain/ dry season of the Chianjen River is significantly higher than those of the Love River. Compared with global data in literature, level of total PAHs concentrations in sediments and suspended solids of the Love River and Chianjen River belongs to moderate pollution. Total PAHs and total organic carbon (TOC) is significantly related except suspended solids of the Chianjen River. However, the relationship between total PAHs concentrations and mean particle size is not significant because of inequilibrium resulted from different sources. Referring to Sediment quality guidelines (SQGs), most of stations are in safe range, only total PAHs concentrations at station L8 in rainy season is significantly higher than the standard ERL value. For each individual compound, the concentrations of many low-molecular-weight PAHs are higher than their standard ERL¡BLET and LAET values. The result of HCA shows that in both dry and rain season, these two rivers¡¦ sediments and suspended solids are separated into upstream and downstream groups. It is believed that the existence of an intercept device set up in midstream of both rivers is the reason. The PAHs in sediments of the Love River is mainly contributed from automobile exhaustion, while suspended solids in the Love River is mainly contributed from petrogenic source. However, both sediments and suspended solids in the Chianjen River are mainly contributed from combustion pollution.

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Since the accelerating development of globalization and market opening, the competitive advantages in this economic environment are innovation, information and market access. Passive component industry usually takes price cost-down strategy to keep the advantage to adapt this formidable pressure from the vicious competition in the market, and the fastest way to implement this strategy is merger & acquisition, then a tendency is formed at this kind of economic situation. This paper focused on 2 M&A models which composed of 4 passive component companies, Yageo, Compostar, Walsin and Pan Overseas. It based on the model analysis for the related issues regarding the common stock exchange ratio in their M&A process. Our study and observation models adopted from the L-G model brought up from Kermit D. Larson and Nicholas J.Gonedes. Furthermore, we take systematic risk indicator(£]) to adjust the marginal condition derived from the highest and lowest exchange ratio of L-G model, then we analyzed by comparing with the actual ratio. With regards to the budget EPS, it was applied to estimate by the reduced form model from Terry A. Marsh and Robert C. Merton. Comparing the estimate result with the actual public M&A information, we found the more information we can use for regression estimation, the much precise estimate results will be. For example, it is close to the results by comparing to the reference estimate digits from Yageo & Walsin models. The decision of actual exchange ratio depends on the bilateral negotiation abilities, and we used L-G model to estimate the reasonable range of exchange ratio. Because of many factors which can not be quantified during the merger negotiation process, the importance of the exchange ratio estimate range from is paper is providing the bottom line for the negotiation, and these key information should be helpful for both parties during the M&A discussion. Recently, M&A process in passive component industry occur frequently, it was said that 2006 is the M&A year for this industry. I wish the empirical result in this paper can provide the reference indication to help the development of passive component industry in the future.

Abstract 2,004 in June get up erupt one after another PROCOMP and so on the land mine stock, has brought the enormous impact to Taiwan's stock market, after these land mine stocks erupt one after another, stimulated the controlling organization to strengthen the management to go on the market the cabinet company's determination, planned many reforms plans and revises many laws, from aggravated illegal criminal and accountant the responsibility, the increase information transparency and realization company internal control aspect and so on execution reduces the possibility which the similar case occurred. Economics Value Added (EVA) is the use Residual Income the idea develops one financial achievements weight target, is different with generally recognizes accountant the principle by creditor's angle establishment finance report form, EVA is looks at the company by the shareholder value viewpoint the management achievement. This research by the economical attachment value inspection document company's transport business condition, examines EVA whether can utilize forecast to the enterprise finance crisis, and one of take documents PROCOMP as the example, carries on the financial ratio analysis, so as to the comparison finance ratio analysis and EVA use in effect of the enterprise finance crisis forecast. Conclusion of the this research as follows: First, by the case study result, the EVA appraisal method may take early warning signal the document corporate finance crisis. Second, the earnings compares by EVA and accountant, EVA can comparatively early respond the company manages the bad question, that is its financial crisis forewarns the effect to compare accountant the earnings to be good. Third, by sole or the sole category finance ratio appraisal document company whole management achievements is insufficient, and is easy to cause to sentence by mistake is appraised the company the real transport business condition.