Papers by Author: Chi Min Shu

Abstract: Risk is a concept that denotes the probability of the occurrence of dangers. The factors that generate fires and dangers are numerous, and always emerge in unapparent places. Once these factors are identified, a fire accident would happen and lead to great loss. For the fires happening in tall buildings that caused immense loss, the function of planned fire separation system was destroyed because the users had weak fire prevention concepts. One of the typical examples is the fire that happened and spread over Don-ke Building in Sijhih City, Taipei County, Taiwan. Based on the damage prevention concepts of property insurance agents, the study focused on the importance of the fire prevention management in tall buildings. The other part that was paid attention to is the Fire Safety Building strongly encouraged and propelled by the Architecture and Building Research Institute of Ministry of the Interior, with which the study conducted an investigation on fire risk management.

Abstract: Investigation of fire accidents is a primary and imperative procedure for human disaster prevention. It engages with the development on the planning program for disaster preventive-remedy and salvage in a city (or a county), and helps to mitigate this calamity effectively in the future, even for a nation. In this study, we investigated and analyzed fire accidents for one of typical rural areas in Asia–Yunlin county, Taiwan, from January, 2003 to August, 2005. This study deals with the statistical data from the Fire-Fighting Department, Yunlin county, Taiwan, including the frequency/probability, potential hazard grades of fire cases within its 20 administrative divisions, and fire occurrence causes, locations, times, divisions, etc., along with comprehensive surveys on the property damage and casualties in Yunlin county during these years. The analytical outcomes indicated that the higher the population concentration (Douliou city, Huwei town, Siluo town and Beigang town), the greater the probability for fire disasters for Yunlin county. This study could help develop corresponding strategies of fire prevention for an agricultural county and even promulgate related regulations to avoid future fire mishaps.

Abstract: Most of the buildings for high-tech plants are fireproof and the process equipment in the clean room is in compliance with high-standard fire prevention evaluation regulations such as National Fire Prevention Association (NFPA), Factory Mutual (FM),and Semiconductor Equipment and Materials International (SEMI). However, fire management is usually neglected though fire protection higher than domestic fire control regulations is applied. Fireproof and smoke-proof design of the original buildings can be damaged due to expansion of production facilities, causing a potential danger of a fire. Cases of fires in domestic semiconductor manufacturing factories were explored in this research and claim settlements provided by MSIG Mingtai Insurance Co., Ltd., Taiwan to high-tech plants were analyzed for determination of the quantified weights used by the insurance companies when evaluating fire risks of a building. The fire safety badge promoted by Architecture and Building Research Institute, and Ministry of the Interior was also discussed for reference of fire safety assessments of high-tech factory buildings in the future.

Abstract: Composite electrodes based on vertically aligned multi-walled carbon nanotubes (MWCNTs) coated with vanadium oxide (V₂O₅) have used in supercapacitors. The vanadium (V) oxide (V₂O₅) cathodically deposited on titanium collector in vanadium oxide solution. The novel supercapacitor performed by V₂O₅/MWCNTs/Ti electrode in 1.0 M HCl aqueous solution can reach a specific capacitance of 713.3 F/g at 10 mV/s, which is larger than that of MWCNTs/Ti. To characterize the V₂O₅/MWCNTs/Ti composite electrode, cyclic voltammetry and galvanostatic charge-discharge method were executed, and the morphology of the composite electrode was examined by scanning electron microscope. This nanocomposite electrode greatly enhanced the utilization efficiency of supercapacitor electrode material, low material cost and provided both high capacitance and power density.

Abstract: This study was focused on the recovery of gallium arsenide (GaAs) from semiconductor fabrication sludge. Wet refined methods were applied to recover gallium (Ga) including acid leaching, purified isolation, electrolysis, and coagulation. The result showed that leaching Ga with nitric acid (HNO₃) was more efficient than with sulfuric acid (H₂SO₄). GaAs could be leached with 4 N HNO₃ to obtain 100% Ga⁺ and arsenic (As^—). The pH was adjusted with sodium hydroxide (NaOH). Then, the solution was extracted by di(2-ethylhexyl) phosphoric acid (D₂EHPA) and was back extracted by H₂SO₄. In this way, Ga extraction efficiency was 80%. At the end of the process, electrolysis was applied to recover Ga. The resulting electrolysis efficiency with nickel-copper was only 56% and its purity was 92%. To further increase the recovery of Ga, the leaching solution was adjusted to alkaline solution and was then electrolyzed with platinum-stainless steel. In this way, recovery and purity could be as high as 90% and 94%, respectively. The removal of arsenic was 86% when the leaching solution was added with ferrous sulfate heptahydrate (Fe₂(SO₄)₃‧_xH₂O) to form iron arsenate (AsFeO₄).

Abstract: This study fully exploited the advantages of the similarities between chitosan and nitrocellulose (NC), their non-toxicity, superior germproof effects, and the characteristic of restraining fungal growth, to prevent NC’s biodegradation. In a comparison between NC’s Ea, the differences among them were dealt with or not with germproof chitosan by differential scanning calorimetry (DSC). We also observed specific functional groups with Fourier transform infrared (FT-IR) spectrometer to characterize the functional group transformation of NC under various thermal conditions.

Abstract: A kinetic model based on the thermal decomposition of 1,3,5-trinitro-1,3,5-triazmane (RDX) was constructed via differential scanning calorimetry (DSC), well-known kinetic equations, curve-fitting analysis, and simulations of thermal analysis. Our objective was to analyze thermokinetic parameters derived from heating rates used in DSC and compare simulations of thermal decomposition under various kinetic models. Experimental results were strongly dependent on the validity of the kinetic model, which was based on an appropriate mathematical model and a proper method for the evaluation of kinetics. Through six types of kinetic algorithms, a reasonable value of the Ea of the thermal decomposition of RDX was obtained. Finally, this study established a novel green technology for the thermal analysis of reactions and obtained information on the characteristics of thermal decomposition and reaction hazards of RDX.

Abstract: Organoclay has a low electrical conductivity and a proper dielectric constant which makes it to be used as a gate insulator. In a dry form, the organoclay exists in aggregates of montmorillonite platelets and very little surface area of the montmorillonite is exposed. For uniform dispersion of the clay aggregated, PA-66 and organically modified Na-montmorillonite (OMMT) were melting blended by using an internal mixer. The crystalline change and effects of intercalation were investigated with X-ray diffraction. Results of thermal properties, micro-structure, surface resistance and crystallization behavior indicated that OMMT had obviously effects on PA-66. DSC results showed that the existent of OMMT had effect on PA-66/OMMT nanocomposites and OMMT content had important effects on the scatter of OMMT in PA-66 matrix.

Abstract: Hydrometallurgical process for recovery of aluminum, lithium and cobalt from the spent secondary lithium–ion batteries of Yun–lin battery recycle corporation was investigated. The recovery efficiency of spent lithium–ion secondary batteries on the hydrometallurgical process of their leachant concentration, temperature (T), time (t), solid–to–liquid ratio (S:L) were investigated. The experimental procedure include the following three major steps: (1) solvent extraction separation of aluminum by NaOH, (2) solvent extraction separation of lithium and cobalt by 3 mol/L H2SO4 (4.76 % (v/v) 35% (v/v) H2O2) from the final solution after aluminum removal. Finally, (3) cobalt are precipitated by ammonium oxalate ((NH4)2C2O4) from the final solutions after aluminum removal. The experimental results for treating 3 g of anode plus in the battery by this new technique were reported, and some evaluation were also carried out. In the processing, the percent removal of impurities, such as aluminum could reach 90.6% or more, and that of lithium and cobalt were all more than 90.0%.

Abstract: A nanocomposite electrode of vertically aligned multi-walled carbon nanotubes (MWCNTs) on gold was fabricated to improve the specific capacitance and power density of the conventional supercapacitor. The novel supercapacitor built from MWCNTs and gold electrode showed a very high specific capacitance of 92.74 F/g using cyclic voltammetry (CV) at 10 mV/s, and 96.43 F/g was measured at 100 Hz. This nanocomposite electrode greatly enhanced the utilization efficiency of supercapacitor electrode material, low material cost and provided both high capacitance and power density. It was shown that the nanocomposite electrode based on vertically aligned carbon nanotube electrode had the characteristics of high specific capacitance.