Dissertations / Theses on the topic 'Stack gases'

The control of particle emissions from an oil refinery is often difficult, due to changing operational conditions and the limited range of available treatment options. Excessive particle emissions have often been attributed start up problems with Fluidized Catalytic Cracker Units (FCCU) and little information is available regarding the exact composition and nature of these excessive emissions. Due to the complex nature of a FCCU, it has in the past been difficult to identify and control emissions, without the use of expensive end of pipe technologies. An Australian Oil Refinery, concerned with their catalyst emissions, sponsored this study of FCCU particle emissions. Due to the industrial nature of the project, a holistic approach to the management of emissions was taken, instead of a detailed investigation of a single issue. By looking at the broader range of issues, practical and useful outcomes can be achieved for the refinery. Initially, detailed emissions samplings were conducted to investigate the degree of particle emissions under start up conditions. Stack emissions were collected during a standard start up, and analysed to determine the particle size distribution and metal concentration of the emitted material. Three distinct stages of emissions were discovered, initially a high concentration of larger particles, followed by a peak in the very fine particles and finally a reduction of particle emissions to a more steady or normal operational state. The variation in particle emissions was caused by operational conditions, hardware design and catalyst characteristics. Fluctuations in the gas velocity through the system altered the ability of the cyclones to collect catalyst material. Also, the low bed level allowed air bypass to occur more readily, contributing to the increased emissions levels seen during the initial stage of the start up. Reduced fluidity characteristics of the circulating catalyst also affected the diplegs operations, altering the collection efficiency of the cyclone. During the loading of catalyst into the system, abraded material was quickly lost due to its particle size, contributing to fine particle emissions levels. More importantly, thermal fracturing of catalyst particles occurred when the cold catalyst was fed into the hot regenerator. Catalyst particles split causing the generation of large amounts of fine particle material, which is easily lost from the system. This loading of catalyst directly linked to the period of high concentration of fine particles in the emissions stream. It was found that metals, and in particular iron, calcium and silicon form a thick layer on the outside of the catalyst, with large irregular shaped metal ridges, forming along the surface of the particle. These ridges reduce the fluidity of the catalyst, leading to potential disruptions in the regenerator. In addition to this, the metal rich ridges are preferentially removed via attrition, causing metal rich material to be emitted into the atmosphere. To overcome these high particle emissions rates from the FCCU the refinery should only use calcinated catalyst to reduce the influence of thermal process and particle fracture and generation. Although the calcinated catalyst can fracture when added to the system, it is far less than that obtained with uncalicinated catalyst. To further reduce the risk of particle fracture due to thermal stresses the refinery should consider reducing the temperature gradients between the hot and cold catalyst. Due to the economics involved with the regenerator, possible pre-warming of catalyst before addition into system is the preferred option. This pre-heating of catalyst should also incorporate a controlled attrition stage to help remove the build up of metals on the surface of the particles whilst allowing this material to be collected before it can be released into the atmosphere. The remove of the metal crust will also improve the fluidity of the system and reduce the chance of catalyst blockages occurring. Finally, modelling of the system has shown that control of key parameters such as particle size and gas velocity are essential to the management of air emissions. The refinery should look at adjusting start up procedures to remove fluctuations in these key parameters. Also the refinery should be careful in using correlation found in the literature to predicted operational conditions in the system as these correlations are misleading when used under industrial situations.

The control of particle emissions from an oil refinery is often difficult, due to changing operational conditions and the limited range of available treatment options. Excessive particle emissions have often been attributed start up problems with Fluidized Catalytic Cracker Units (FCCU) and little information is available regarding the exact composition and nature of these excessive emissions. Due to the complex nature of a FCCU, it has in the past been difficult to identify and control emissions, without the use of expensive end of pipe technologies. An Australian Oil Refinery, concerned with their catalyst emissions, sponsored this study of FCCU particle emissions. Due to the industrial nature of the project, a holistic approach to the management of emissions was taken, instead of a detailed investigation of a single issue. By looking at the broader range of issues, practical and useful outcomes can be achieved for the refinery. Initially, detailed emissions samplings were conducted to investigate the degree of particle emissions under start up conditions. Stack emissions were collected during a standard start up, and analysed to determine the particle size distribution and metal concentration of the emitted material. Three distinct stages of emissions were discovered, initially a high concentration of larger particles, followed by a peak in the very fine particles and finally a reduction of particle emissions to a more steady or normal operational state. The variation in particle emissions was caused by operational conditions, hardware design and catalyst characteristics. Fluctuations in the gas velocity through the system altered the ability of the cyclones to collect catalyst material. Also, the low bed level allowed air bypass to occur more readily, contributing to the increased emissions levels seen during the initial stage of the start up. Reduced fluidity characteristics of the circulating catalyst also affected the diplegs operations, altering the collection efficiency of the cyclone. During the loading of catalyst into the system, abraded material was quickly lost due to its particle size, contributing to fine particle emissions levels. More importantly, thermal fracturing of catalyst particles occurred when the cold catalyst was fed into the hot regenerator. Catalyst particles split causing the generation of large amounts of fine particle material, which is easily lost from the system. This loading of catalyst directly linked to the period of high concentration of fine particles in the emissions stream. It was found that metals, and in particular iron, calcium and silicon form a thick layer on the outside of the catalyst, with large irregular shaped metal ridges, forming along the surface of the particle. These ridges reduce the fluidity of the catalyst, leading to potential disruptions in the regenerator. In addition to this, the metal rich ridges are preferentially removed via attrition, causing metal rich material to be emitted into the atmosphere. To overcome these high particle emissions rates from the FCCU the refinery should only use calcinated catalyst to reduce the influence of thermal process and particle fracture and generation. Although the calcinated catalyst can fracture when added to the system, it is far less than that obtained with uncalicinated catalyst. To further reduce the risk of particle fracture due to thermal stresses the refinery should consider reducing the temperature gradients between the hot and cold catalyst. Due to the economics involved with the regenerator, possible pre-warming of catalyst before addition into system is the preferred option. This pre-heating of catalyst should also incorporate a controlled attrition stage to help remove the build up of metals on the surface of the particles whilst allowing this material to be collected before it can be released into the atmosphere. The remove of the metal crust will also improve the fluidity of the system and reduce the chance of catalyst blockages occurring. Finally, modelling of the system has shown that control of key parameters such as particle size and gas velocity are essential to the management of air emissions. The refinery should look at adjusting start up procedures to remove fluctuations in these key parameters. Also the refinery should be careful in using correlation found in the literature to predicted operational conditions in the system as these correlations are misleading when used under industrial situations.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental Engineering
Faculty of Environmental Sciences
Full Text

The continued scaling of device dimensions in complementary metal oxide semiconductor (CMOS) technology within the sub-100 nm region requires an alternative high dielectric constant (high-k) oxide layer to counter high tunneling leakage currents, a metallic gate electrode to address polysilicon depletion, boron penetration and high polysilicon sheet resistance, and high mobility channel materials to boost the CMOS performance. Metal gates can also offer improved thermal and chemical stability, but their use requires that we improve our understanding of how the metal alloy phase, crystallographic orientation, and composition affect the electronic properties of the metal alloy-oxide interface. To replace n++ and p++ polysilicon gate electrodes and maintain scaled device performance requires metal gate electrodes with work functions within 0.2 eV of the silicon conduction and valence band edges, i.e., 5.0-5.2 and 4.1-4.3 eV, for PMOS and NMOS devices, respectively. In addition to work function and thermal/chemical stability, metal gates must be integrated into the CMOS process flow. It is the aim of this work to significantly expand our knowledge base in alloys for dual metal gates by carrying out detailed electrical and materials studies of the binary alloy systems of Ru with p-type metal Pt. Three n-type metals systems, Ru-Ta, Ru-Hf and Ru-Nb have also been partially investigated. This work also focuses on high mobility Ge p-MOSFETs for improved CMOS performance. DC magnetron sputtering has been used to deposit binary alloy films on thermally grown SiO2. The composition of the alloy films have been determined by Rutherford backscattering spectrometry and the identification of phases present have been made using x-ray and electron diffraction of samples. The microstructure of the phases of interest has been examined in the transmission electron microscope and film texture was characterized via x-ray diffraction. The electrical characterization includes basic resistivity measurements, and work function extraction. The work function has been determined from MOS capacitor and Schottky diodes. The need for electron and hole mobility enhancement and the progress in the development of high-k gate stacks, has lead to renewed interest in Ge MOSFETs. The p-MOS mobility data for Ge channel devices have been reported. The results indicate greater than 2 x improvements in device mobility as compared to standard Si device. A low frequency noise assessment of silicon passivated Ge p-MOSFETs with a TiN/TaN/HfO2 gate stack has been made. For the first time we also report results on low frequency noise characterisation for a Ge P+- n junctions with and without Ni germanidation.
Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering

This thesis explores the procedural generation of 3D buildings from the floor plan all the way to the fa¸cade and building’s details such as doors, windows, and roof. Through this, the study explores several techniques and approaches to create different layers of the building generation pipeline. The focus is on implementing a set of algorithms that, when running sequentially, are able to create complete 3D buildings in a short time (so they can be used in online generation), could be used in any open-world game, and with a limited count of triangles per building. Furthermore, the tool provides a clear and easy-to-use interface for designers in Unity, where they can interact with the multiple parameters of each building layer, giving designers a high degree of controllability. The tool is evaluated using the resulting buildings based on different metrics and how individual changes to different parameter starting from a template affect the output of the generator in terms of the metrics and the resulting building. The result from the analysis show that the polygon mathematics is well suited for generating 3D buildings for games.

碩士
正修科技大學
化工與材料工程研究所
94
A new and suitable method for sampling and measuring polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans (PBDD/Fs) have been established in this study by modifying the standard method of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). Six large scale municipal solid waste incinerators (MSWIs) and four industrial waste incinerators (IWIs) are investigated the characteristics of PBDD/Fs in the stack flue gases, respectively. In addition, for PCDD/Fs and PBDD/Fs of the ambient air of Rural sites, Urban sites, industrial areas, and Science Parks. We will proceed sampling and analysis to establish the characteristics of ambient air. The mean PBDD/F concentration in the stack flue gases of these MSWIs was 0.319 pg TEQ/Nm3 (Ranged: 0.127～0.515 pg TEQ/Nm3; RSD：49%) and the mean ratio of the PBDD/F TEQ concentration to the PCDD/F TEQ concentration was 0.58% (Ranged: 0.265%～0.876%; RSD：37.9%). Meanwhile, the mean PBDD/F concentration in the stack flue gases of these IWIs was 4.51 pg TEQ/Nm3 (Ranged: 2.57～7.02 pg TEQ/Nm3; RSD：44.65%) and the mean ratio of the PBDD/F TEQ concentration to the PCDD/F TEQ concentration was 3.66% (Ranged: 0.713%～6.13%; RSD：60.6%). The ratio of the PBDD/F TEQ concentration to the PCDD/F TEQ concentration in the stack flue gases of IWIs is 28.6 times higher that that of MSWIs. It may be result from that the bromine content in the industrial waste is higher than that in municipal solid waste. The low bromine substituted PBDD/Fs were predominant in both the PBDD/F congener profiles in the stack flue gases of MSWIs and IWIs, not like PCDD/Fs, which were predominant by high chlorine substituted PCDD/Fs. The reason is that the bromine atom is bigger so the formation of high bromine substituted PBDD/Fs is more difficult. Furthermore, the original generated high bromine substituted PBDD/Fs could have more bromine substituted position to be replaced by chlorine so that the following PXDD/Fs can not be detected by HRGC/HRMS. The average value of PBDD/F concentration in Ambient air of Rural sites, Urban sites, and industrial sites, were 0.00162 pg TEQ/Nm3 (Ranged: 0.000102～0.00315 pg TEQ/Nm3; RSD：79.7%), and 0.0045 pg TEQ/Nm3, 0.011 pg TEQ/Nm3 (Ranged: 0.0039～0.0158 pg TEQ/Nm3; RSD：44%) respectively.

博士
國立成功大學
環境工程學系
102
The aim of this research is to investigate the emissions of persistent organic pollutants (POPs) from two types of biomass burnings. An industrial boiler study of woodchip combustion and co-combustion of woodchip and industrial wastewater sludge (IWTS) was conducted and followed by a open field study for various biomass open burnings (or few waste burnings) in the region of Southeast Asia in 2010 and 2013. For the industrial boiler study, the emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) from trial combustion of 10 wt% dried industrial-wastewater-treatment sludge (IWTS) and 90 wt% woodchip in an industrial boiler were investigated and compared to that from woodchip combustion. The PBDD/F toxic equivalent (TEQ) and PBDE emissions increased from 0.121 pg TEQ/Nm3 and 2,260 pg/Nm3, respectively, of the woodchip combustion to 0.211 pg TEQ/Nm3 and 4,200 pg/Nm3, respectively, of the trial combustion. PBDD/F and PBDE congener profiles of inputs and outputs of the same type of combustion were similar; they also show similarity between woodchip and trial combustions, revealing that the destruction pathway was little affected by the introduction of the IWTS. The fates of PBDD/Fs and PBDEs show that the indigenous pollutants in the feed were effectively depleted (〉93.5%). The dominant releasing route of PBDD/F and PBDE shifted from the stack flue gas of woodchip combustion to the ashes of trial combustion. The industrial boiler study demonstrates that co-combustion not only handles the fast growing sludge stream, but also yields a saving of 26.3% in the fuel cost and treatment fees of sludge and ashes. The Southeast Asian biomass burning is the first that comprehensively discusses the long-range atmospheric transport behavior of combustion originated POPs, including polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PCDEs), PBDD/Fs, polybrominated biphenyls (PBBs), and PBDEs. The POP emissions at the biomass burning sites in Vietnam (Da Nang in 2010 and Son La in 2013) and Thailand (Chiang Mai in 2010 and Doi Ang Khang (DAK) in 2013) were characterized, as well as the influence of the Southeast Asian biomass burnings on the Lulin Atmospheric Background Station (LABS) in Taiwan. The ambient air in Vietnam seems to be more seriously affected by the local biomass burnings than that in Thailand for the Southeast Asian biomass burning study in 2010 and 2013. For the study in 2010, the elevated atmospheric brominated POP (PBDD/Fs, PBBs and PBDEs) concentrations in Da Nang were attributed to the biomass burning and viewed as mostly unrelated to the local use of brominated flame retardants. In the spring of 2010, the mean atmospheric concentrations in LABS during the first and second Intensive Observation Periods (IOPs) were 0.00428 and 0.00232 pg I-TEQ/Nm3 for PCDD/Fs, 0.000311 and 0.000282 pg WHO-TEQ/m3 for PCBs, 0.000379 and 0.000449 pg TEQ/Nm3 for total PBDD/Fs, 0.0208 and 0.0163 pg/Nm3 for total PBBs, and 109 and 18.2 pg/Nm3 for total PBDEs, respectively. These values represent the effects by the Southeast Asian biomass burnings. For the study in 2013, results of statistical analyses on the POP concentrations are individually consistent with the characteristics of POP congener profiles in Son La and DAK, revealing they were influenced by the local burnings. The PM2.5 samples were collected in the 2013 study. Well correlations were found between PM2.5 and each of the biomass burning originated-POPs in the three sites. Based on the backward trajectories, the correlations can be used to predict the (site specific) future biomass burning affected POPs from PM2.5.

碩士
國立成功大學
環境工程學系碩博士班
91
Polychlorinated dibenzo-p-dioxins and Polychlorinated dibenzofurans (PCDD/Fs) are semi-volatile toxic compounds. The US EPA has identified PCDD/Fs as potential human carcinogens. 2,3,7,8-TeCDD is the most toxic PCDD/Fs. Notably, the International Agency for Research on Cancer (IARC) has classified 2,3,7,8-TCDD as “carcinogenic to humans”. The US EPA reported that combustion is the major source of PCDD/Fs, and moreover that municipal solid waste incinerators (MSWIs) are the significant contributor to the PCDD/Fs inventory. MSWIs contributed 65.8% of total PCDD/Fs emissions in 1987; moreover, the combined PCDD/Fs emissions of MSWIs and medical waste incinerators (MWIs) reached 86.4%. Consequently, the effect of stack flue gases from waste incinerators on PCDD/Fs in ambient air cannot be ignored. This study investigates how PCDD/Fs from stack flue gases of MSWIs affect the atmosphere, soil and plants. Two MSWIs (TC and CY) are examined. The stack flue gases of MSWIs, ambient air, soil and plants of maximum ground concentration are sampled and measured for PCDD/Fs to determine the influence of MSWIs and establish a native PCDD/Fs database. Mean PCDD/Fs concentration in the stack flue gases of TC and CY were 0.0213 and 0.0065 ng-I-TEQ/Nm3, respectively; mean PCDD/Fs concentration in the atmosphere of TC and CY was 0.0436 and 0.173 pg-I-TEQ/Nm3, respectively; mean PCDD/Fs content in the plants of TC and CY was 3.72 and 2.24 pg-I-TEQ/g, respectively, and mean PCDD/Fs content in the soils of TC and CY was 1.85 and 15.7 pg-I-TEQ/g, respectively. By comparing maximum ground concentration for upwind and downwind sampling sites, and using PCA and cluster analyses, the effect of PCDD/Fs from the stack flue gases of TC and CY on the atmosphere, soil and plants is unclear. The PCDD/Fs concentrations in the atmosphere in this study are lower than in Tokyo and Yokohama. According to various studies, soil PCDD/Fs content around MSWIs ranges between 0.11 and 356 pg-I-TEQ/g, and the PCDD/Fs content of Taiwanese soil falls at the low-end of this range. By linear regression, the connections among atmosphere, plants and soils are not apparent. The reason for this phenomenon may be that the atmospheric PCDD/Fs concentrations are based on the mean over three days, while the PCDD/Fs contents in plants or soil are based on a longer exposure time and the decomposition rates of PCDD/Fs differ among these media. Suggested future research directions include investigating the PCDD/Fs gas/particulate partition in the atmosphere and the PCDD/Fs content in different particulate size to better understand the fate of PCDD/Fs in the environment.

碩士
國立成功大學
環境工程學系碩博士班
93
This study examined the characteristics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in emissions, ambient air‚ leaves and soil at the Y industrial zone. The following PCDD/Fs emmision sources were investigated: one large-scale municipal solid waste incinerator (MSWI1); one small-scale municipal solid waste incinerator (MSWI2); one medical waste incinerator (MWI); one coke oven plane (COKE); three sinter planes (SNs); five electric furnaces (EAFs); and, one secondary aluminum smelter (ALS). The emission factors of PCDD/Fs in the stack flue gases were determined‚ and the overall emission quantity of PCDD/Fs from the Y industrial zone was estimated. Finally, the influence of these emission sources on the surrounding environment was assessed. The concentration means from the stack flue gases were as follows: large-scale MSWI, 0.0917ng I-TEQ/Nm3; small-scale MSWI, 10.8ng I-TEQ/Nm3; MWI, 0.557ng I-TEQ/Nm3; COKE, 0.0369ng I-TEQ/Nm3; SNs, 1.41ng I-TEQ/Nm3; EAFs, 0.196ng I-TEQ/Nm3; and, ALS 0.245ng I-TEQ/Nm3. The emission factors of PCDD/Fs from the stack flue gases were as follows: large-scale MSWI, 0.696 μg I-TEQ/ton-waste; small-scale MSWI, 26.0 μg I-TEQ/ton-waste; and, MWI, 6.95 μg I-TEQ/ton-waste. The emission factors of PCDD/Fs from the stack flue gases were as follows: COKE, 0.155 μg I-TEQ/ton-feedstock; SNs, 2.21 μg I-TEQ/ton-feedstock; EAFs, 1.49 μg I-TEQ/ton-feedstock; and, ALS, 4.29 μg I-TEQ/ton-feedstock. The estimated total annual emission of PCDD/Fs from these emission sources in the Y industrial zone was 37.98 g I-TEQ/yr (large-scale MSWIs, 0.848%; small-scale MSWIs, 0.445%; medical waste incinerators, 0.0219%; industrial waste incinerator, 0.0226%; coke oven planes, 2.60%; sinter planes, 86.1%; electric furnaces, 6.48%; secondary aluminum smelters, 1.78%; secondary copper smelters, 1.71%). The analytical results revealed that the annual emission of PCDD/Fs from metallurgical processes reached a maximum value in the Y industrial zone. The sum of annual emission from SNs and EAFs was 92.6%. 　　The PCDD/Fs concentrations of ambient air around the Y industrial zone ranged from 0.0576~0.260 pg I-TEQ/Nm3 (mean, 0.116 pg I-TEQ/Nm3). The average amount of PCDD/Fs in leaves and soil around the Y industrial zone were, respectively, 9.49 and 10.6 ng I-TEQ/kg. The distribution curve of PCDD/Fs concentrations indicates that the area downwind of the SNs and EAFs had higher PCDD/Fs levels in ambient air, leaves and soil. Furthermore‚ the congener profiles of the stack fule gases of the SNs and EAFs had a strong resemblance to the congener profiles of ambient air. Therefore, the concentrations of PCDD/Fs in ambient air, leaves and soil around the Y industrial zone were significantly influenced by emissions from the SNs and EAFs.

碩士
國立成功大學
環境工程學系碩博士班
98
This study examined the characteristics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in emissions, ambient air? leaves and soil at the Y city. The following PCDD/Fs emmision sources were investigated: two small-scale industrial waste incinerator (IWIs); one medical waste incinerator (MWI); four sinter planes (SINTERs); five electric furnaces (EAFs); one secondary aluminum smelter (ALS); one secondary zinc smelter (ZN); one cement kiln (CEM); and, one crematorium (CRE). The emission factors of PCDD/Fs in the stack flue gases were determined? and the overall emission quantity of PCDD/Fs from the Y city was estimated. Finally, the influence of these emission sources on the surrounding environment was assessed. The mean PCDD/F concentrations in the stack flue gases were as follows: IWIs, 0.0299ng I-TEQ/Nm3; MWI, 0.202ng I-TEQ/Nm3; EAFs, 0.238ng I-TEQ/Nm3; SINTERs, 0.311ng I-TEQ/Nm3; CEM, 0.0207ng I-TEQ/Nm3; ALSs, 0.0868ng I-TEQ/Nm3; CRE 0.251ng I-TEQ/Nm3; and, ZN 0.0118ng I-TEQ/Nm3. The estimated total annual emission of PCDD/Fs from these emission sources in the industrial zone was 13.4 g I-TEQ/yr (large-scale MSWIs, 0.86%; small-scale MSWIs, 0.0026%; industrial waste incinerators, 0.077%; medical waste incinerators, 0.017%; electric furnaces, 60.8%; sinter planes, 37.0%; coke oven planes, 0.35%; cement kilns, 0.048%; secondary aluminum smelters, 0.62%; secondary zinc smelters, 0.019%; secondary copper smelters, 0.090%; Crematorium,0.28%). The PCDD/F emissions from metallurgical processes were dominant, and comprised 98.9% of the total PCDD/F annual emissions.

碩士
國立成功大學
環境工程學系碩博士班
92
This study investigates the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the stack flue gases of municipal solid waste incinerators (MSWIs) S and C to evaluate the influence of MSWIs and establish a native PCDD/F database. Additionally, reducing the PCDD/F emission from the stack flue gas by adding antioxidation enzyme is also investigated. 　　The conclusions of this study are summarized as follows: First, at steady operation, the mean PCDD/F concentrations in the stack flue gases of MSWI S and C are 0.0408 and 0.179 ng I-TEQ/Nm3, respectively. Secondly, in start-up of the MSWI-S, the mean PCDD/F concentrations in the stack flue gas is 13.8 ng I-TEQ/Nm3 and a total of 35.2 mg I-TEQ of PCDD/Fs was estimated in the start-up period. The PCDD/F emission in start-up equals 40.5% of one year emissions in steady operation. Thirdly, the PCDD/F removal efficiency by bag filters of MSWI-S and MSWI-C were 99.8％ and -340％, respectively. The negative PCDD/F removal efficiency of MSWI-C may be owing to the memory effect. After replacing filters, the PCDD/F removal efficiency reached 70.9％. Finally, after spraying antioxidation enzyme, the PCDD/F concentration in the stack flue gases of MSWI-S is declined, and reaches the lowest point since MSWI-S started operation. In addition, the five PCDD/F concentrations of one stack flue gas sampling have less deviation than former data. In summary, the effect of spraying antioxidation enzyme on the PCDD/F concentration in the stack flue gases of MSWI-S is obvious.

碩士
大葉大學
環境工程學系碩士在職專班
96
The goal of this study is to calculate the risk factors for emission from secondary copper smelters factories in Changhua County. Exhaust air samples, ambient samples and dust samples from ground were collected to examine the heavy metal concentrations. The maximum ground level concentrations were obtained using ISCST3 model by providing exhaust emission for dust from smelting furnace. The carcinogenicity risk was assessed by substituting the metal concentrations from ambient and ground surface. The results from field sampling in A and B factories showed heavy metals (lead, cadmium, mercury, chromium and copper) from flue gas are below the current national control standard. Compares to U.S. EPA SPECIATE V4.0 database, the criteria pollutants are Al, Fe, Cu and Zn. Copper rolls zone in A factory and copper product casting operation area in B factory provide the major emission for heavy metals from ambient heavy metal sampling. The lead, zinc, chromium and copper exceed the soil pollution monitor standard. The maximum ground level concentration for metal is 0.00836μg/m3 predicted by ISCST3 model. In addition, Winter plays an important role on heavy metal distribution in the air. The predicted ambient concentration in Changhua air quality station (3-5 kilometers from sources of pollution) is 0.0047μg/m3. This indicates that pollution source contributed 1% to Changhua station, and revealed that other sources of pollution probably contributed from nearby factories. The carcinogenicity risk was 2.2×10-3 for cadmium and 3.6×10-3 for chromium, which all exceeded the carcinogenicity risk. However, the HI value was 0.746, and lower than marginal value of 1. The carcinogenic risk value for cadmium and chromium is bigger than 10-6, and showed the carcinogenic risk.

碩士
國立成功大學
環境工程學系碩博士班
95
This study investigated the characteristics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in the stack flue gases and ashes of two municipal waste incinerators (MSWI-C and MSWI-S). Results obtained will be helpful to understand the PCDD/Fs formation mechanisms and to provide the useful information for the operation of incinerators. The stack flue gas and fabric filter ash from MSWI-C, and the stack flue gas and ashes (including bottom, super heater, economizer, semi-dry scrubber, fabric filter and ash storing tube) from the MSWI-S were sampled to analyze their PCDD/F and chlorine contents. Results show that the mean total-PCDD/F concentration and the mean PCDD/F emission factors in the stack flue gases of MSWI-C and MSWI-S are 0.0359 and 0.133 and ng I-TEQ/Nm3, and 0.223 and 0.968 μg I-TEQ/ton-waste, respectively. The mean total-PCDD/F and chlorine contents in the fabric filter ash from MSWI-C are 0.392 ng I-TEQ/g and 47.8 mg/g, respectively. On the other hand, the mean total-PCDD/F and chlorine contents in the ashes of bottom, super heater, economizer, semi-dry scrubber, fabric filter and ash storing tube of MSWI-S are 0.00811, 0.0411, 4.71, 0.317, 1.45 and 2.46 ng I-TEQ/g, and 5.27, 33.0, 46.5, 85.2,142 and 163 mg/g, respectively. It was found that the operating temperatures of combustion chamber and super heater are unsuitable for PCDD/F formation; therefore, the PCDD/F contents of the bottom and the super heater ashes were very low. When the flue gas passed through the economizer, the PCDD/F contents increase obviously due to its appropriate temperature of PCDD/F formation. However, the PCDD/F content in the ash of semi dry scrubber is quickly dropped because of the addition of lime. Although the operating temperature of the fabric filter has fallen to 164°C, the relatively long resident time of ashes and the capture reaction of the activated carbon caused the higher PCDD/F contents. Moreover, the “dioxinous hazardous industrial waste” with overall toxic equivalent concentration exceeding 1.0ng I-TEQ/g has been designated as hazardous waste by Taiwan EPA on December 2006. Consequently, due to the exceeding contents of economizer, fabric filter and ash storing tube ashes, those will be recognized as the hazardous waste.

碩士
國立成功大學
環境工程學系碩博士班
94
In order to understand the influences of surrounding environments from PCDD/Fs emission sources in the Y industrial zone, the following PCDD/Fs emission sources were investigated: two large-scale municipal solid waste incinerators (MSWI1 and MSWI2); one small-scale municipal solid waste incinerator (MSWI3); two industrial waste incinerators (IWI1 and IWI2); one medical waste incinerator (MWI); five electric furnaces (EAFs); four sinter planes (SINTERs); one coke oven plane (COKE); one cement kiln (CEMENT); two secondary aluminum smelters (ALS1 and ALS2); and, one secondary copper smelter (COP). By the investigations of these PCDD/Fs in the stack flue gas of emission sources, the overall emission quantity of PCDD/Fs from the Y industrial zone and the congener profiles in the stack flue gas was estimated. Furthermore, we chose ten sampling sites to investigate PCDD/Fs concentrations in ambient air‚ leaves and soil around the Y industrial zone and the non-industrial zone. By the comparisons between the PCDD/Fs concentrations in environmental media and the PCDD/Fs concentrations from PCDD/Fs emission sources using cluster analysis and principal component analysis, the influence of these emission sources on the surrounding environment was assessed. The concentration means from the stack flue gases were as follows: large-scale MSWIs, 0.0632ng I-TEQ/Nm3; small-scale MSWI, 0.239ng I-TEQ/Nm3; IWIs, 0.145ng I-TEQ/Nm3; MWI, 1.64ng I-TEQ/Nm3; EAFs, 0.477ng I-TEQ/Nm3; SINTERs, 0.326ng I-TEQ/Nm3; COKE, 0.00870ng I-TEQ/Nm3; CEMENT, 0.0138ng I-TEQ/Nm3; ALSs, 0.0504ng I-TEQ/Nm3; and, COP 0.310ng I-TEQ/Nm3. The emission factors of PCDD/Fs from the stack flue gases were as follows: large-scale MSWIs, 0.750 μg I-TEQ/ton-waste; small-scale MSWI, 0.874 μg I-TEQ/ton-waste; IWIs, 3.30 μg I-TEQ/ton-waste; and MWI, 16.7 μg I-TEQ/ton-waste. The emission factors of PCDD/Fs from the stack flue gases were as follows: EAFs, 3.64 μg I-TEQ/ton-feedstock; SINTERs, 0.455 μg I-TEQ/ton-feedstock; COKE, 0.0134 μg I-TEQ/ton-feedstock; CEMENT, 0.00891 μg I-TEQ/ton-feedstock; ALSs, 1.40 μg I-TEQ/ton-feedstock; and, COP, 0.735 μg I-TEQ/ton-feedstock. The estimated total annual emission of PCDD/Fs from these emission sources in the Y industrial zone was 13.1 g I-TEQ/yr (large-scale MSWIs, 0.885%; small-scale MSWIs, 0.0188%; industrial waste incinerators, 0.114%; medical waste incinerators, 0.215%; electric furnaces, 33.9%; sinter planes, 64.0%; coke oven planes, 0.197%; cement kilns, 0.0922%; secondary aluminum smelters, 0.162%; and secondary copper smelters, 0.409%). The analytical results revealed that the annual emission of PCDD/Fs from metallurgical processes reached a maximum value in the Y industrial zone. The sum of annual emission from EAFs and SINTERs was 97.9%. The PCDD/Fs average concentrations of ambient air for four seasons around the Y industrial zone were 0.0765, 0.0707, 0.132 and 0.0903 pg I-TEQ/Nm3. The distribution curve of PCDD/Fs concentrations for four seasons indicates that the area downwind of the EAFs and SINTERs had higher PCDD/Fs levels in ambient air. And as a result we concluded that the PCDD/Fs concentrations of ambient air around the Y industrial zone were affected by the EAFs and SINTERs. The PCDD/Fs average concentrations of leaves for four seasons around the Y industrial zone were 7.85, 3.17, 5.41, and 10.6 ng I-TEQ/kg. From the distribution curve of PCDD/Fs concentrations of the first season, we found that the area downwind of the EAFs and SINTERs had higher PCDD/Fs levels in the leaves. And as a result we concluded that the PCDD/Fs concentrations of leaves from the first season around the Y industrial zone were affected by the EAFs and SINTERs. The distribution curve of PCDD/Fs concentrations of leaves from the second, third and fourth seasons seems to be intimate with other pollution sources. The edges of H and J sampling sites had higher PCDD/Fs levels in leaves. The PCDD/Fs average concentrations of soil for four seasons around the Y industrial zone were 6.08, 5.78, 10.2, and 11.3 ng I-TEQ/kg. The distribution curve of PCDD/Fs concentrations for four seasons seems to be intimate with other pollution sources and the edges of H and J sampling sites had higher PCDD/Fs levels in the soil.

Abstract in English
Incineration is still a widely utilised method for treating healthcare risk waste in the Republic of South Africa. As much as incinerators are needed, the fact that they are still a critical source of hazardous toxic air pollutants that are not easy to manage cannot be disregarded. The Ministry of Environmental Affairs has promulgated a new regulation for General and Hazardous Waste Thermal Treatment. This exceedingly stringent air pollution legislation requires that existing incinerators be modified or redesigned to meet the new air quality standards, or face closure in the event that they fail to comply. The regulation contains strict emission requirements for concentrations of stack gases such as CO2, NO2, NOx, HCl, HF, CO, SO2, as well as TOC and PM. To be certain that emissions are within the standard, incineration facilities are instructed to reduce the acid gas emissions and to have permanent on-line monitoring equipment for stack testing of regulated pollutants. Since the promulgation of the new legislation in April 2015, none of the incinerators in South Africa has been able to achieve the new requirements. This study, based on the quantitative approach, was conducted in search of a cost-effective method of controlling acid gas emissions from incinerators without major adjustments to the plants. During the study, 60 kg of sorbacal Ca(OH)2 was injected into a lime feeder every day. A variable speed drive was used to inject Ca(OH)2 into the furnace continuously at a rate of between 2.5 kg/h and 3.5 kg/h. The temperature was maintained between 850°C and 1200°C with the use of four gas burners. Two manual blowers were utilised to ensure a continuous flow of Ca(OH)2 into the reaction chamber and filtration system. Comparative analysis was done to compare gas emission levels before and after the use of hydrated lime. Descriptive statistics were used to compute the mean, frequency and percentages, while Wilcoxon sign rank test established whether hydrated lime was significant in reducing gaseous emissions or not. Wilcoxon sign rank test showed a statistically significant difference (P<0.05) in the reduction of all gaseous emissions using hydrated lime, except particulate matter where there was a significant increase in emissions. This technology was able to achieve high removal efficiency of 97% for HCl, 86% for HF, 83% for NOx, 87% for SO2 and 74% for NO2. The optimum temperature for SO2 and NOx was 1020°C. For HCl it was between 1190°C and 1200°C, and for NO2 it was between 1120°C and 1200°C. The amount of particulate matter increased along with the concentration of the Ca(OH)2 injections. Ca(OH)2 was found to be cost effective in the controlling and capturing of gaseous emissions. It is recommended that combustion requirements, such as heat, oxygen and turbulence, be considered to reduce the amount of gases generated during the incineration of healthcare risk waste. It is also recommended that electrostatic precipitators be used instead of fabric filters to improve the efficiency of capturing the particulate matter.
Environmental Sciences
M.Sc. (Environmental Science)

碩士
雲林科技大學
財務金融系碩士班
97
In this paper, procedures developed to explore the Olympic Games and the relationship between the host country, thereby affecting the country''s economy and stock markets. Based on historical experience and data statistics, the Olympic Games to the host country will bring considerable economic income for the country''s contribution to GDP that year can not, therefore, before the Olympic Games held its a good reason is also expected. In this paper, the stock market trends will be organized to seek Austrian two years ago to run the stock market during the period when changes in plans, analysis of the Olympic Games to the host country''s economy and its impact on the stock market. The host of the Olympic Games through the history of research and analysis show that: one year before the Olympic Games held in the stock market performance indicators usually (before October 2007 is indeed the case in China), held in the Olympic Games that year, the market tends to decline, but usually in the subsequent year will once again rebound; also found that the Olympic Games host country will increase public confidence, which enhance the consumer, the relevant inputs and efficiency of the building will enhance the continued growth of tourism brought about by the huge increase in national income. These may significantly impact the overall demand growth in the stock market. The past 10 Olympic Games experience has shown that the previous year in the Olympics host country stock index has risen by an average of 25 percent, in the Olympic Games and the Olympic Games does have a significant growth during the round of "Olympic market."

碩士
國立高雄第一科技大學
風險管理與保險研究所
101
Multiculturalism has been a feature of Taiwanese society, the government continued to encourage people engaged in creative industry activity in recent years. Due to the popularity of Internet technology, the traditional single user game which is limited to computer has a new breakthrough. Online game industry has become emerging industry in the twentieth century. People live in reduced circumstances. In addition to non-essential activities, instead of going out, many people surfing internet at home to save money. Staying at home has unknowingly become a new philosophy of life. People begin to engage business and social activities in internet. In addition to internet auction, playing online games has become a way of entertainment at home. Thus, it contributes to the major online game companies begin developing new online games, even agents many kind of foreign hot online games publisher. Many investors are also eager to stock trading of these companies. They believe that the stock price raises high possibility as long as issuing the new online games. This study uses the event study to investigate the company''s share price. By observing the different periods of average abnormal returns and cumulative average abnormal returns of the company''s share price chart to analyze the company''s share price. And understands how long an online game craze can continue to affect the stock price. Next, using t-test, cross-sectional test and sign test analysis of online game companies may have abnormal stock price returns when these online game companies issue online games during open beta period. Last, using paired t test to analyze whether other online game company’s stock returns will be affected or not when the online game company issues online games during open beta period. Therefore, it provides opinions for investors when they want to buy game stocks.

碩士
亞洲大學
財務金融學系碩士在職專班
107
This study investigates the impact of international sports games hosted by Taiwan on the stock returns of sports commodity companies. We use the event study method to analyze whether the stock price of sports industrial companies generate abnormal return and cumulative abnormal return when Taiwan holds international sports events. The sample period covers 2000 to 2018. Empirical studies have found that most of the international games hosted by Taiwan can have a positive impact on the stock price of the sports industry. This finding implies that if Taiwanese government can actively organize international sports games, it can attract investment in sports-related companies and drive the stock price of the industry to rise.

碩士
真理大學
經濟學系財經碩士班
102
Usually, hosting mega sport need to inject huge source and will gain more, this will improve the economic and stock market. In past, the research focused on “obtain the right to host” how to influence the stock market, but the major activity will be done nearby event day. In this paper, we use the event study to exam the effect of Olympic Games and FIFA on stock market and compare the differences before and after event day during 2002-2014. We find that the effect of hosting mega sport on stock market can distinguish in different country and games. First, if the country’s stock market return below the average, hosting mega sport will have significant effect. Before the event day it will increasing the cumulative abnormal return (CAR), after the event day the CAR will decreasing. Second, the impact of Summer Olympic on stock market are more significant than FIFA and Winter Olympic. Summer Olympic will increasing the return of stock market after the event day. But there are no obvious different before and after event day in stock market return for FIFA and Winter Olympic.

Chapter 1: Although there are widely accepted theoretical explanations for overexploitation of common-pool resources, empirically we have limited information about the micro-level mechanisms that cause individually efficient exploitation to result in macro inefficiency. This paper conducts the first empirical investigation of common-pool resource users' dynamic and strategic behavior at the micro level. With an application to the North Carolina shrimp fishery, we examine fishermen's strategies in a fully dynamic game that accounts for latent resource dynamics and other players' actions. Combining a simulation-based Conditional Choice Probability estimator and a Pseudo Maximum Likelihood estimator, we recover the profit structure of the fishery from fishermen's repeated choices. Using the estimated structural parameters, we compare the fishermen's actual exploitation path to the socially optimal one under a time-specific limited entry system with transferrable permits, and then quantify the dynamic efficiency costs of common-pool resource use. We find that individual fishermen respond to other users by exerting a higher level of exploitation effort than what is socially optimal. Based on our counterfactual experiments, we estimate the efficiency costs of this behavior to be 17.39\% of the annual revenues from the fishery, which translates into 31.4\% of the rent without deducting the cost of capital.

Chapter 2: Although hypoxia is a threat to coastal ecosystems, policy makers have limited information about the potential economic impacts on fisheries. Studies using spatially and temporally aggregated data generally fail to detect statistically significant fishery effects of hypoxia. Limited recent work using disaggregated fishing data (microdata) reports modest effects of hypoxia on catches of recreationally harvested species. These prior studies have not accounted for important spatial and temporal aspects of the system, however. For example, the effects of hypoxia on catches may not materialize instantaneously but instead may involve a lagged process with catches reflecting cumulative past exposure to environmental conditions. This paper develops a differenced bioeconomic model to account for the lagged effects of hypoxia on the North Carolina brown shrimp fishery. It integrates high-resolution oxygen monitoring data with fishery-dependent microdata from North Carolina's trip ticket program to investigate the detailed spatial and temporal relationships of hypoxia to commercial fishery harvest. The main finding is that hypoxia potentially resulted in a 12.9\% annual decrease in brown shrimp harvest from 1999-2005. The paper also develops two alternative models---a non-differenced model and a polynomial distributed lag model---and results are consistent with the main model.

Chapter 3: The emergence of ecosystem-based management suggests that traditional fisheries

management and protection of environmental quality are increasingly interrelated. Fishery managers, however, have limited control over most sources of marine and estuarine pollution and at best can only adapt to environmental conditions. We develop a bioeconomic model of optimal harvest of an annual species that is subject to an environmental disturbance. We parameterize the model to analyze the effect of hypoxia (low dissolved oxygen) on the optimal harvest path of brown shrimp, a commercially important species that is fished in hypoxic waters in the Gulf of Mexico and in estuaries in the southeastern United States. We find that hypoxia alters the qualitative pattern of optimal harvest and shifts the season opening earlier in the year; more severe hypoxia leads to even earlier season openings. However, the quantitative effects of adapting fishery management to hypoxia in terms of fishery rents are small. This suggests that it is critical for other regulatory agencies to control estuarine pollution, and fishery managers need to generate value from the fishery resources through other means such as rationalization.

Dissertation